Guided Tour
风电入门 ——Danish Wind Industry Association
——丹麦风电工业协会风电指导用书Wind 风.....................................................................................................................................5
Whence wind? 风是从哪里来的?...............................................................................5The coriolis force 克里奥利力.......................................................................................7Global winds 全球风.......................................................................................................8Geostrophic wind 地转风.............................................................................................10Local winds局域风.......................................................................................................11Mountain winds山地风................................................................................................13Energy in the wind 风能...............................................................................................14Wind deflection 风的偏转...........................................................................................16Anemometers 风速计................................................................................................21Measurement in practice 实际测量...........................................................................24The wind rose 风玫瑰图.............................................................................................26Draw a wind rose 画风玫瑰图....................................................................................31
Turbine sitin 风机选址...........................................................................................................34Roughness & shear 粗糙度与风剪切.......................................................................34Speed calculation 速度计算........................................................................................38Escarpments 陡坡.......................................................................................................42The roughness rose 粗糙度玫瑰图...........................................................................44Variable winds 可变风.................................................................................................46Turbulence 湍流..........................................................................................................48Wind obstacles 风障碍物...........................................................................................49Wind shade 风影..........................................................................................................52Calculator guide 计算器指南......................................................................................54Shade calculator 风影计算器.....................................................................................61Wake 尾流....................................................................................................................63The park effect 风场效应............................................................................................65The tunnel effect 风洞效应.........................................................................................67The hill effect 山丘效应..............................................................................................69Turbine siting 风机选址.............................................................................................71Selecting a Wind Turbine Site 选择一处风机场址..........................................71Offshore winds 海上风能.............................................................................................74Wind map Europe 欧洲风图........................................................................................77Wind map Denmark 丹麦的风图...............................................................................80
Energy output 能量输出........................................................................................................84The Weibull distribution 威布尔分布.........................................................................84Distribution plotting 分布绘图......................................................................................87The average bottle fallacy 平均的瓶形谬误.............................................................88
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Mean power of the wind 平均风功率........................................................................90Betz' law 贝兹定律......................................................................................................92Power density 功率密度.............................................................................................94Power curves 功率曲线..............................................................................................97The power coefficient 功率系数..............................................................................101Calculator guide 计算器指南....................................................................................103The power calculator 功率计算器............................................................................112Annual energy output 年度能量输出.......................................................................116
How does it work? 风力发电机是如何工作的?................................................................120Components部件.......................................................................................................120Lift 升力........................................................................................................................120Stall and drag失速和阻力.........................................................................................122Sum of wind speeds风速的总和..............................................................................123Rotor aerodynamics 转轮空气动力学......................................................................125Rotor blades 转轮叶片...............................................................................................127Power control功率控制.............................................................................................129The yaw mechanism 偏航机构.................................................................................135Towers 塔架.................................................................................................................137The size of turbines 风机尺寸...................................................................................142Turbine Safety 风机的安全........................................................................................146Labour safety 职业安全.............................................................................................150
Generators发电机................................................................................................................152Generators发电机......................................................................................................152Synchronous machines同步机................................................................................155No. of poles极对数....................................................................................................159Asynchronous machines异步机..............................................................................161Changing no. of poles改变极数...............................................................................166Variable slip可变滑差................................................................................................169Indirect grid connection间接电网连接.....................................................................173Gearboxes齿轮箱......................................................................................................177Controllers控制器......................................................................................................179Power quality电能质量..............................................................................................182
Turbine design涡轮机设计..................................................................................................185Load considerations载荷考虑..................................................................................185Horizontal/vertical水平/竖直.....................................................................................189Upwind/downwind上风向/下风向.............................................................................192No. of rotor blades转轮叶片数量.............................................................................194Optimising turbines优化涡轮机................................................................................197Low mechanical noise低机械噪声...........................................................................199Low aerodynamic noise低气动噪声........................................................................202
Manufacturing制造业..........................................................................................................206Nacelles机舱..............................................................................................................206Blade testing叶片测试...............................................................................................206Towers塔架.................................................................................................................211
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Welding towers焊接塔架...........................................................................................214Installing towers安装塔架.........................................................................................215Offshore foundations海上基础.................................................................................217
R & D研究与开发...............................................................................................................220R & D in wind风力的研究与开发..............................................................................220Research in offshore海上研究.................................................................................222Foundations at sea海上基础....................................................................................225Concrete caissons混凝土沉箱.................................................................................227Steel gravitaty foundations钢重力基础...................................................................229Monopile foundations单桩基础................................................................................232Tripod foundations三脚架基础.................................................................................234
Electrical grid电网...............................................................................................................236Variations in energy能量变化...................................................................................236Seasonal variations季节性变化...............................................................................238Power quality电能质量..............................................................................................239Offshore wind and grid海上风力和电网..................................................................245
Environment环境.................................................................................................................249Landscape and turbines景观与风力机...................................................................249Aerial markings航空标志............................................................................................252Sound from turbines风力机的声音.............................................................................258Sound measurement声音测量.....................................................................................262Sound map calculator 声音图计算器..........................................................................268Sound calculator 声音计算器.......................................................................................269Energy balance 能量平衡.............................................................................................271Birds and wind turbines 鸟类和风力机.......................................................................273Birds and offshore wind鸟类和海上风力...................................................................275Shadow casting 投影....................................................................................................278Shadow calculation阴影计算......................................................................................281Better calculations更好的计算...................................................................................283
Shadow variations阴影变化........................................................................................287Guide to calculator计算器指南...................................................................................290Shadow calculator 阴影计算器....................................................................................301
Economics 经济性................................................................................................................307Turbine costs 风力机成本............................................................................................307Turbine installation 风力机安装,.................................................................................309O & M 运行和维护......................................................................................................311Income from wind energy 风能的收入........................................................................314Tariffs 价目表...............................................................................................................316Investment in wind power 风电的投资........................................................................320Economics of wind energy 风能经济学.......................................................................324Traps in analyses 分析中易犯的错误..........................................................................327Guide to the calculator 计算器指南.............................................................................338Economics calculator 经济学计算器...........................................................................343Economics of offshore wind 海上风力的经济性.........................................................347
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Employment 就业.........................................................................................................349History of wind energy 风能的历史.....................................................................................353
Introduction 前言......................................................................................................353Charles F. Brush 查尔斯•弗朗西丝•布拉什(Charles Francis Brush)..........354Poul la Cour 保罗·拉·库尔(Poul la Cour).........................................................3631940-1956...................................................................................................................366Johannes Juul 约翰内斯·尤尔................................................................................3671980s 20世纪 80年代.............................................................................................370The great wind rush 浩大的风能潮........................................................................374Modern wind turbines 现代风力机.........................................................................376Offshore wind turbines 海上风力机........................................................................377Megawatt turbines 兆瓦级风力机...........................................................................384Multi mega machines 多兆瓦级风力机..................................................................386
Wind energy manual 风能手册..........................................................................................389Index 索引.................................................................................................................389Wind energy concepts 风能概念............................................................................392Energy and power 能量和功率...............................................................................399Proof of Betz' law 贝兹定律的证明.........................................................................404Wind turbine acoustics 风力机声学.......................................................................406Electricity 电..............................................................................................................4103 phased electricity 3相交流电..............................................................................4143 phased connection 3相连接形式........................................................................415Electromagnetism 1 电磁效应 1.............................................................................417Electromagnetism 2 电磁效应 2.............................................................................418Induction 1 感应 1.....................................................................................................418Induction 2 感应 2.....................................................................................................419Environment and fuels 环境与燃料........................................................................420Bibliography 参考文献.............................................................................................422Glossary 词汇表.......................................................................................................426
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Wind 风
Whence wind? 风是从哪里来的?
Where does Wind Energy come From? 风是从哪里来的?All renewable energy (except tidal and geothermal power), and even the
energy in fossil fuels, ultimately comes from the sun. The sun radiates
174,423,000,000,000 kilowatt hours of energy to the earth per hour. In other
words, the earth receives 1.74 x 10 17 watts of power . 1)
所有可再生能源(潮汐能与地热能除外),即使是矿物能源,最终都来自
于太阳。每小时太阳辐射 174,423,000,000,000KWh的能量到地球上来。换句话
说,地球接受 1.74×1017W的功率 1。About 1 to 2 per cent of the energy coming from the sun is converted into
wind energy. That is about 50 to 100 times more than the energy converted
into biomass by all plants on earth. 2)
来自太阳的能量,大约有 1-2%转换成风能。约为地球上所有植物将太阳能
转换成生物质能的 50-100倍 2。
Temperature Differences Drive Air Circulation 温差驱动空气流动
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The regions around equator, at 0° latitude are heated more by the sun than
the rest of the globe. These hot areas are indicated in the warm colours, red,
orange and yellow in this infrared picture of sea surface temperatures (taken
from a NASA satellite, NOAA-7 in July 1984).
在赤道地区,即 0°纬度地区,太阳加热超过地球上的其他地区。下图给出
了海洋表面温度的红外照片(取自 NASA的卫星图片, NOAA-7,1984年 7月),
暖色,红色、橘黄色和黄色,表明了受热区域。Hot air is lighter than cold air and will rise into the sky until it reaches
approximately 10 km (6 miles) altitude and will spread to the North and the
South. If the globe did not rotate, the air would simply arrive at the North Pole
and the South Pole, sink down, and return to the equator.
热空气比冷空气轻,将升上天空,直到升至大约 10公里(6英里)的高度,
然后向南北半球扩散。如果地球不旋转,空气就会简单地到达北极和南极,然后
下降,最后又回到了赤道。1) The power emission from the sun is 1.37 kW/m 2 on the surface of
the sphere, which has the sun as its centre and the average radius of
the earth trajectory. The power hits a circular disc with an area of of
1.27 x 10 14 m 2 . The power emitted to the earth is thus 1.74 x 10 17 W.
太阳发射至地球表面的功率密度为 1.37 kW/m2,这是以太阳为圆心,以地球轨迹的平均半径计算的。发射功率投射到面积为 1.27 x 10 14 m2。因此,发射到地球上的功
率为 1.74 x 10 17 W。6
2) On average, plant net primary production is about 4.95 x 10 6 calories per
square metre per year. This is global NPP, Global net primary production , i.e.
the amount of energy available to all subsequent links in the food/energy
chain. The earth's surface area is 5.09 x 10 14 m 2 . The net power output
stored by plants is thus 1.91 x 10 13 W, or 0.011% of the power emitted to
earth. You may find the conversion factor between the energy units calories
and Joule in the reference manual.
平均说来,植物的初始净产能(NPP)约为每平方米每年 4.95 x 10 6卡。这是全
球的 NPP,也就是以后可利用的食品/能源链的总量。地球表面积是于是 5.09 x
10 14 m 2,植物所储存的净功率输出为 1.91 x 10 13 W,或者为发射到地球上的
功率的 0.011%。在参考手册中,你可以找到能量单位卡路里和焦耳的转换因子
The coriolis force 克里奥利力
Since the globe is rotating, any movement on the Northern hemisphere is
diverted to the right, if we look at it from our own position on the ground. (In
the southern hemisphere it is bent to the left). This apparent bending force is
known as the Coriolis force. (Named after the French mathematician Gustave
Gaspard Coriolis 1792-1843).
因为地球是旋转的,因此,从我们自己所在地球上的位置来看一个运动,
北半球的任何运动都会向右偏移(在南半球它就会向左弯曲)。这种显而易见的
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弯曲力就称为克里奥利力。(在法国数学家古斯塔夫 ·盖斯帕德·克里奥利
(1792-1843)故去后命名的)It may not be obvious to you that a particle moving on the northern
hemisphere will be bending towards the right.
一个质点在北半球运动的时候会向右偏移,你看起来可能不明显。Consider this red cone moving southward in the direction of
the tip of the cone. The earth is spinning, while we watch the
spectacle from a camera fixed in outer space. The cone is
moving straight towards the south.
考虑一个红色的锥体,它的锥尖方向朝南运动。地球是旋转的,这是固定在
外太空的照相机所观察到的景象。锥体直接朝南运动。Note that the red cone is veering in a curve towards the right as it moves.
The reason why it is not following the direction in which the cone is pointing
is, of course, that we as observers are rotating along with the globe
注意到红色椎体当它运动的时候向右弯曲。为什么它不遵循锥体原来指定的
方向,原因在于观察者随地球在旋转。Here we show the same image with the camera locked on
to the globe.
当照相机锁定在地球上的时候,我们会看到同样的图象。Here we show the same image,with the camera
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fixed in outer space, while the earth rotates.
当照相机固定在外太空,而地球在旋转的时候,我们也会看到同样的图象。The Coriolis force is a visible phenomenon. Railroad tracks wear out faster on
one side than the other. River beds are dug deeper on one side than the
other. (Which side depends on which hemisphere we are in: In the Northern
hemisphere moving particles are bent towards the right).
克里奥利力是一种可视现象。铁轨的一侧比另一侧磨损快。河床的一侧比另
一侧冲刷得深。(到底那一侧取决于我们所在的半球:在北半球运动质点向右
偏)。In the Northern hemisphere the wind tends to rotate counterclockwise (as
seen from above) as it approaches a low pressure area. In the Southern
hemisphere the wind rotates clockwise around low pressure areas.
在北半球,风倾向于逆时针旋转进入低压区域。在南半球,风倾向于顺时针
旋转进入低压区域。On the next page we shall see how the Coriolis force affects the wind
directions on the globe.
下一节我们将看到克里奥利力如何影响全球风向的。
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Global winds 全球风
Wind Energy Resources: Global Winds 风能资源: 全球风 How the Coriolis Force Affects Global Winds
克里奥利力如何影响全球风向的 The wind rises from the equator and moves north and south in the higher
layers of the atmosphere.
风在赤道上升并在大气的高层向南北移动。Around 30°; latitude in both hemispheres the Coriolis
force prevents the air from moving much farther. At
this latitude there is a high pressure area, as the air
begins sinking down again.
在南北半球 30°纬度处,克里奥利力对空气运动的阻力迅速增强,在这一
纬度形成一个高压区域,空气开始沉降 。As the wind rises from the equator there will be a low pressure area close to
ground level attracting winds from the North and South.
因为赤道的风上升,在近地表面就形成了一个低压区域,这一区域将吸引
南北方向的来风。At the Poles, there will be high pressure due to the cooling of the air.
在极地,由于空气的冷却将形成冷高压。
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Keeping in mind the bending force of the Coriolis force, we thus have the
following general results for the prevailing wind direction:
记住克里奥利力的弯曲效应,对于主风向我们会导出下列的普遍结果:Prevailing Wind Directions 主风向Latitude纬度 90-60°N 60-30°N 30-0°N 0-30°S 30-60°S 60-90°S
Direction 风向 NE SW NE SE NW SE
The size of the atmosphere is grossly exaggerated in the picture above (which
was made on a photograph from the NASA GOES-8 satellite). In reality the
atmosphere is only 10 km thick, i.e. 1/1200 of the diameter of the globe. That
part of the atmosphere is more accurately known as the troposphere. This is
where all of our weather (and the greenhouse effect) occurs.The prevailing
wind directions are important when siting wind turbines, since we obviously
want to place them in the areas with least obstacles from the prevailing wind
directions. Local geography, however, may influence the general results in the
table above, cf. the following pages.
在上述图片中(由 NASA GOES-8卫星拍摄的照片),大气的尺度做了夸
大。实际上大气只有 10KM厚,即为地球直径的 1/1200。那部分大气更精确地应
称为对流层。这就是我们所说的天气以及温室效应所发生的地方。当风机选址时
主风向是非常重要的。因为我们显然希望把风机放在具有最少障碍物的主风向区
域。但是,局部的地形可能影响上表中的普遍结果,请参阅下一节。
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Geostrophic wind 地转风
The Geostrophic Wind 地转风 The Atmosphere (Troposphere) 大气 (对流层)
The atmosphere around the globe is a very thin layer. The globe has a
diameter of 12,000 km. The troposphere, which extends to about 11 km
(36,000 ft.) altitude, is where all of our weather, and the greenhouse effect
occurs.
绕地球的大气是很薄的一层。地球直径为 1200公里。对流层扩展到 11公里
高处,这就是我们所说的天气以及温室效应所发生的地方。On the picture you can see a stretch
of islands 300 km (200 miles) across,
and the approximate height of the
troposphere. To look at it at a different
scale: If the globe were a ball with a
diameter of 1.2 metres (4 ft.), the
atmosphere would only be 1 mm
(1/25") thick.
在图片中你可以看到延伸 300KM的岛屿以及同温层的近似高度。按不同的
比例看它,如果地球是一个直径 1.2m的球体,大气层只有 1mm厚。The Geostrophic Wind 地转风The winds we have been considering on the previous pages on global winds
are actually the geostrophic winds. The geostrophic winds are largely driven
by temperature differences, and thus pressure differences, and are not very
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much influenced by the surface of the earth. The geostrophic wind is found at
altitudes above 1000 metres (3300 ft.) above ground level.
上一节中所考虑的全球的风资源实际上就是地转风。地转风主要是由温差产
生的压差驱动的,地球表面对其并没有很大的影响。地转风是在 1000m高度上
形成的。The geostrophic wind speed may be measured using weather balloons.
地转风的速度可以利用气球进行测量。Surface Winds 地表风 Winds are very much influenced by the ground surface at altitudes up to 100
metres. The wind will be slowed down by the earth's surface roughness and
obstacles, as we will learn in a moment. Wind directions near the surface will
be slightly different from the direction of the geostrophic wind because of the
earth's rotation (cf. the Coriolis force ).
在离地表面 100m以内的高度上,地表对风产生很大的影响。地球表面粗糙
度和障碍物将使风速减缓,一会儿我们会讲到。由于地球的旋转,地表附近的风
向会与同温层的风向稍有不同(参见克里奥利力)。When dealing with wind energy, we are concerned with surface winds, and
how to calculate the usable energy content of the wind.
涉及到风能,我们要关心地表风以及如何计算可用的风能。
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Local winds 局域风
Local Winds: Sea Breezes 局域风: 海上微风Although global winds are important in determining the prevailing winds in a
given area, local climatic conditions may wield an influence on the most
common wind directions.
尽管全球风对确定给定区域的主风向是重要的,局域气候条件可能对最常
规的风向产生影响。Local winds are always superimposed upon the larger scale wind systems,
i.e. the wind direction is influenced by the sum of global and local effects.
When larger scale winds are light, local winds may dominate the wind
patterns.
局域风是叠加在大尺度风能系统中的,也就是说风向是受全球风和局域风
综合影响的。当大尺度风较轻时,局域风可能决定着风的类型。Sea Breezes 海上微风
Land masses are heated by the sun more
quickly than the sea in the daytime. The air
rises, flows out to the sea, and creates a low
pressure at ground level which attracts the cool
air from the sea. This is called a sea breeze. At
nightfall there is often a period of calm when
land and sea temperatures are equal.
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白天,陆地上的气团比海上的气团被太阳加热的要快。这部分空气上升,流
到海上,在地面产生了低气压,从而吸引了来自海上的冷空气。这称作海上微风
在夜间,当陆地和海上温度相等的时候,就有一个风的平静期。At night the wind blows in the opposite direction. The land breeze at night
generally has lower wind speeds, because the temperature difference
between land and sea is smaller at night.
夜间风在相反的方向吹过。陆地的微风夜间具有很低的风速,因为夜间陆地
和海上的温差小。The monsoon known from South-East Asia is in reality a large-scale form of
the sea breeze and land breeze, varying in its direction between seasons,
because land masses are heated or cooled more quickly than the sea.
东南亚季风实际上是海上微风和陆上微风的大尺度形式,其方向随季节而
变化,因为陆上气团比海上气团加热或冷却得更快。
Mountain winds 山地风
Local Winds: Mountain Winds 局域风:山地风
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Mountain regions display many interesting weather patterns. One example is
the valley wind which originates on south-facing slopes (north-facing in the
southern hemisphere). When the slopes and the neighbouring air are heated
the density of the air decreases, and the air ascends towards the top following
the surface of the slope. At night the wind direction is reversed, and turns into
a downslope wind.
山地区域表现出很有趣的天气模式。一个例子是谷风,它起源于朝南的(在
南半球是朝北的)斜坡上。当斜坡和邻近的空气被加热的时候,空气的密度降低
空气顺着斜坡朝顶部上升。在夜间风向相反,风向自斜坡向下。If the valley floor is sloped, the air may move down or up the valley, as a
canyon wind.
如果峡谷地面是倾斜的,空气沿着峡谷向上或向下,这就是峡谷风。Winds flowing down the leeward sides of mountains can be quite powerful:
Examples are the Foehn in the Alps in Europe, the Chinook in the Rocky
Mountains, and the Zonda in the Andes.
流向山下的风很快增强。例如,欧洲阿尔卑斯山的焚风,岩石山的Chinook
风,安第斯山的佐达风。
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Examples of other local wind systems are the Mistral flowing down the Rhone
valley into the Mediterranean Sea, the Scirocco, a southerly wind from Sahara
blowing into the Mediterranean sea.
其他局域风的例子是:由Rhone山谷向下刮到地中海的Mistral风。有撒哈
拉吹入地中海的南风,即 Scirocco非洲热风。
Energy in the wind 风能
The Energy in the Wind: Air Density and Rotor Area
风能: 空气密度和转轮面积 A wind turbine obtains its power input by converting the
force of the wind into a torque (turning force) acting on
the rotor blades. The amount of energy which the wind
transfers to the rotor depends on the density of the air,
the rotor area, and the wind speed.
风机把风力转换成作用在转轮叶片上的力矩(一种
旋转的力),从而获得功率输入。风传递到转轮上的能量取决于空气密度、转轮
面积和风速。The cartoon shows how a cylindrical slice of air 1 metre thick moves through
the 2,300 m 2 rotor of a typical 1,000 kilowatt wind turbine.
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卡通表明,一团厚 1m的圆筒的空气是如何通过 1MW风机 2,300 m2的转
轮的。With a 54 metre rotor diameter each cylinder actually weighs 2.8 tonnes, i.e.
2,300 times 1.225 kilograms。
对于 54m的转轮直径,每一圆筒实际重 2.8吨,也就是说,为 1.225Kg的
2300倍。Density of Air 空气密度The kinetic energy of a moving body is proportional to its mass (or weight).
The kinetic energy in the wind thus depends on the density of the air, i.e. its
mass per unit of volume.
运动物体的动能与其质量成正比。因此,风的动能取决于空气密度,即单位
体积的质量。In other words, the "heavier" the air, the more energy is received by the
turbine.
换句话说,空气越重,风机就会接收越多的能量。At normal atmospheric pressure and at 15° Celsius air weighs some 1.225
kilogrammes per cubic metre, but the density decreases slightly with
increasing humidity.
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在标准大气压下,15℃时每m3空气重 1.225Kg,但是密度随着温度的增
加稍有降低。Also, the air is denser when it is cold than when it is warm. At high altitudes,
(in mountains) the air pressure is lower, and the air is less dense.
同时,冷空气密度较暖空气高。在高海拔处(在山上)气压低,空气密度也
低。Rotor Area 转轮面积A typical 1,000 kW wind turbine has a rotor diameter of 54 metres, i.e. a rotor
area of some 2,300 square metres. The rotor area determines how much
energy a wind turbine is able to harvest from the wind.
一台典型的 1MW风机转轮直径 54m,即转轮面积约 2300m2。转轮面积决
定了风机能够从风中获取多少能量。Since the rotor area increases with the square of the rotor diameter, a turbine
which is twice as large will receive 2 2 = 2 x 2 = four times as much energy.
The page on the size of wind turbines gives you more details.
因为转轮面积随转轮直径的平方而增加,风机转轮提高一倍,即
22=2×2,风机会获得 4倍的能量。在风机尺寸那节将给你详析介绍。
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Wind deflection 风的偏转
Wind Turbines Deflect the Wind 风机使风偏转
The image on the previous page on the energy in the wind is a bit simplified.
In reality, a wind turbine will deflect the wind, even before the wind reaches
the rotor plane. This means that we will never be able to capture all of the
energy in the wind using a wind turbine. We will discuss this later, when we
get to Betz' Law.
前一节给出的风能的概念有点简单。实际上,风机会使风偏转,甚至于在风
到达转轮之前业已偏转。这就意味着利用风机我们决不能捕获到全部风能。以后
当我们进入贝兹定律一节时,会讲到这一点。In the image above we have the wind coming from the right, and we use a
device to capture part of the kinetic energy in the wind. (In this case we use a
three bladed rotor, but it could be some other mechanical device).
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在上面的图片中,我们看到了风从右边来,我们用一个装置来捕获风的部
分动能(在这个案例中,我们使用三叶片转轮,当然也可以使用其他的机械装
置)。The Stream Tube 流管The wind turbine rotor must obviously slow down the wind as it captures its
kinetic energy and converts it into rotational energy. This means that the wind
will be moving more slowly to the left of the rotor than to the right of the rotor.
显然,当风机捕获到风的动能并将它转换成旋转机械能的时候,风速就降低了。
这意味着风在转轮左侧比在右侧运动得更慢。Since the amount of air entering through the swept rotor area from the right
(every second) must be the same as the amount of air leaving the rotor area
to the left, the air will have to occupy a larger cross section (diameter) behind
the rotor plane.
因为(每秒)从右侧进入扫掠面积的空气量一定与在左侧离开扫掠面积的空气
量相等,空气离开转轮后空气的截面积(假想圆筒直径)会放大。In the image above we have illustrated this by showing an imaginary tube, a
so called stream tube around the wind turbine rotor. The stream tube shows
how the slow moving wind to the left in the picture will occupy a large volume
behind the rotor.
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在上面的图画中,利用假想的管可以勾画出这种流动。围绕风机转轮的这种
假想管称为流管。流管表明风如何减速流入左侧的,并标明转轮后的空气体积变
大。The wind will not be slowed down to its final speed immediately behind the
rotor plane. The slowdown will happen gradually behind the rotor, until the
speed becomes almost constant.
在转轮后,风不会立刻降到最终速度。转轮后风速的下降有一个渐进的过程
直到达到几乎恒定的速度。The Air Pressure Distribution in Front of and Behind the Rotor 转轮前后空气压力分布
The graph to the left shows the air pressure
plotted vertically, while the horizontal axis
indicates the distance from the rotor plane. The
wind is coming from the right, and the rotor is in the middle of the graph.
左图表明,垂直轴为空气压力,而水平轴表示到转轮的距离。风从右侧进入
转轮位于图的中间。As the wind approaches the rotor from the right, the air pressure increases
gradually, since the rotor acts as a barrier to the wind. Note, that the air
pressure will drop immediately behind the rotor plane (to the left). It then
gradually increases to the normal air pressure level in the area.
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当风从右侧靠近转轮,由于转轮是一个栏栅,空气压逐渐增加。注意,在转轮后
(在左侧)空气压立即下降。然后,气压渐渐增加到该区域的常压水平。What Happens Farther Downstream? 再往下游发生了什么?If we move farther downstream the turbulence in the wind will cause the slow
wind behind the rotor to mix with the faster moving wind from the surrounding
area. The wind shade behind the rotor will therefore gradually diminish as we
move away from the turbine. We will discus this further on the page about the
park effect.
如果继续向下游移动,风中的湍流将会发生,这是因为转轮后的缓慢流动
与周围区域的快速流动相混合所致。由于气团离开了风机,转轮后的风影将逐渐
减弱。关于风场效应,下节我们将进一步讨论。Why not a Cylindrical Stream Tube? 为什么不是一个圆筒流管Now, you may object that a turbine would be rotating, even if we placed it
within a normal, cylindrical tube, like the one below. Why do we insist that the
stream tube is bottle-shaped?
现在,你可以把风机放在一个常规的圆筒管中,如下图所示,你会对风机
的旋转持有异议。为什么我们要主张流管是瓶状的呢?
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Of course you would be right that the turbine rotor could turn if it were placed
in a large glass tube like the one above, but let us consider what happens:
当然,你可能是对的,如果把风机放在如上图所示的大的玻璃筒里,风机
转轮会转。然而,我们想一下,会发生什么情况:The wind to the left of the rotor moves with a lower speed than the wind to the
right of the rotor. But at the same time we know that the volume of air entering
the tube from the right each second must be the same as the volume of air
leaving the tube to the left. We can therefore deduce that if we have some
obstacle to the wind (in this case our rotor) within the tube, then some of the
air coming from the right must be deflected from entering the tube (due to the
high air pressure in the right ende of the tube).
转轮左侧的风与转轮右侧的风比较会以较低的速度运动。但是,同时我们也
知道每秒从右侧进入流管的空气体积必须与从左侧流出流管的空气体积相同。因
此,我们可以推断,如果在流管中风遇到某些障碍(这一案例就是转轮),从
右侧进入的某些空气就必须从进入管偏离(由于管右端空气压力高)。
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So, the cylindrical tube is not an accurate picture of what happens to the wind
when it meets a wind turbine. This picture at the top of the page is the correct
picture.
因此,当风遇到风机时所发生的情况表明,圆筒形流管不是一个精确地图
像。本节顶部的图片才是一个正确的图像。
Wind speeds & energy 风速与风能The Power of the Wind: Cube of Wind Speed 风功率:风速的立方The wind speed is extremely important for the amount of energy a wind
turbine can convert to electricity: The energy content of the wind varies with
the cube (the third power) of the average wind speed, e.g. if the wind speed is
twice as high it contains 2 3 = 2 x 2 x 2 = eight times as much energy.
风速对于风机能够把多少风能转换成电能十分重要。风能依风速的立方(三
次方)而变化,例如如果风速加一倍,风能则增至八倍,即 23=8。Now, why does the energy in the wind vary with the third power of wind
speed? Well, from everyday knowledge you may be aware that if you double
the speed of a car, it takes four times as much energy to brake it down to a
standstill. (Essentially this is Newton's second law of motion).
现在讨论,为什么风能随风速的立方而变化。好了,从常识我们知道,如果把你的汽车速度加倍,想踩刹车使其停止要花费 4倍的能量(实际上这是牛顿第二定律)。In the case of the wind turbine we use the energy from
braking the wind, and if we double the wind speed, we
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get twice as many slices of wind moving through the rotor every second, and
each of those slices contains four times as much energy, as we learned from
the example of braking a car.
关于风机的案例,我们使用能量对风机进行刹车。如果把风速加倍,每秒将
有两倍移动的空气圆片通过;正如,我们在汽车刹车的例子中学过的,每一个
圆片会含有 4倍的能量。The graph shows that at a wind speed of 8 metres per second we get a power
(amount of energy per second) of 314 Watts per square metre exposed to the
wind (the wind is coming from a direction perpendicular to the swept rotor
area).
该图表示,在每秒 8m的风速我们能得到迎风面(风垂直掠过转轮的平
面)每m2 314W的功率(每秒的能量)。At 16 m/s we get eight times as much power, i.e. 2509 W/m 2. The table in the
Reference Manual section gives you the power per square metre exposed to
the wind for different wind speeds.
在 16 m/s我们会得到 8倍的功率,即 2509 W/m 2。参考手册表格部分给出
了不同风速下迎风面的每平方米的功率。Power of the Wind Formula 风功率的公式
The power of the wind passing perpendicularly through a circular area is:
垂直通过环形面积的风功率:
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P = 1/2 v3 r2
Where P = the power of the wind measured in W (Watt).
其中 P =风功率,单位W
= (rho) = the density of dry air = 1.225 measured in kg/m 3 (kilogrammes per cubic
metre, at average atmospheric pressure at sea level at 15° C).
=干空气密度=1.225Kg/m3(在 15℃的海平面平均气压下)
v = the velocity of the wind measured in m/s (metres per second). = (pi) =
3.1415926535...
v =风速,单位m/s, =3.141592653
r = the radius (i.e. half the diameter) of the rotor measured in m (metres).
r =转轮的半径,单位m
Anemometers 风速计
Wind Speed Measurement: Anemometers 风速的测量:风速计The measurement of wind speeds is usually done using a
cup anemometer, such as the one in the picture to the left.
The cup anemometer has a vertical axis and three cups
which capture the wind. The number of revolutions per minute is registered
electronically.
测量风速通常使用风杯风速计,如左图所示。风杯风速计有一个垂直轴和三
个风杯,用风杯捕获来风。每分钟的转数以电信号记录。Normally, the anemometer is fitted with a wind vane to detect the wind
direction.
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通常,风速计装有风向标以便检测风向。Instead of cups, anemometers may be fitted with propellers, although this is
not common.
为替代风杯,风速计可以安装螺旋桨,但这并不经常采用。Other anemometer types include ultrasonic or laser anemometers which
detect the phase shifting of sound or coherent light reflected from the air
molecules. Hot wire anemometers detect the wind speed through minute
temperature differences between wires placed in the wind and in the wind
shade (the lee side).
其他风速计包括超声波风速计和激光风速计,其原理是检测声音的相移或
检测空气分子反射的干涉光。还有热线风速计,其原理是通过放在风中和背风处
的两段导线,测其微小的温差来检测风速的。The advantage of non-mechanical anemometers may be that they are less
sensitive to icing. In practice, however, cup anemometers tend to be used
everywhere, and special models with electrically heated shafts and cups may
be used in arctic areas.
非机械风速计的优点是它们对结霜不敏感。但实际上,风杯风速计已经到处
使用。特种型号的风杯风速计带有电加热轴,这种风杯可以用在北极地区。Quality Anemometers are a Necessity for Wind Energy Measurement 高质量的风速计对于风能测量是必要的
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You often get what you pay for, when you buy something. That also applies to
anemometers. You can buy surprisingly cheap anemometers from some of
the major vendors in the business. They may be OK for meteorology, and
they are OK to mount on a wind turbine, where a large accuracy is not really
important.*) But cheap anemometers are not usable for wind speed
measurement in the wind energy industry, since they may be very inaccurate
and calibrated poorly, with measurement errors of maybe 5 per cent or even
10 per cent.
人们买东西,常常讲一分钱一分货。这也适合于风速计。你能够从小贩手里
买到过于便宜的风速计。这类风速计用在气象上可能还可以,安装在风机上也还
行。那些地方高精度实际上不重要*)。但是,便宜的风速计不能用到风能产业的
风速测量,因为它们很不精确,也没有很好校准,测量误差可能有 5%,甚至
于 10%。If you are planning to build a wind farm it may be an economic disaster if you
have an anemometer which measures wind speeds with a 10% error. In that
case, you may risk counting on an energy content of the wind which is 1.1 3 -
1 = 33% higher than than it is in reality. If you have to recalculate your
measurements to a different wind turbine hub height (say, from 10 to 50 m
height), you may even multiply that error with a factor of 1.3, thus you end up
with a 75% error on your energy calculation.
如果你计划建一个风场,你有选一台误差为 10%的风速计进行测风,那么
这个风场在经济上就可能遭殃。在那种情况下,你可能有风能期望的风险,就是
29
说期望的风能比实际的高 33%,即 1.1 3 - 1 = 33%。如果你必须对于风机的不同
轮毂高度(比如说 10m到 50m高)重新计算你的测量,你甚至要用 1.3 乘上那
个误差,于是你最终能量计算的误差达到 75%。It is possible to buy a professional, well calibrated anemometer with a
measurement error around 1% for about 700-900 USD. That is quite plainly
peanuts compared to the risk of making a potentially disastrous economic
error. Naturally, price may not always be a reliable indicator of quality, so ask
someone from a well reputed wind energy research institution for advice on
purchasing anemometers.
你花 700-900 美元买一台专业的、完好校准的风速计,其测量误差约为 1%
是可能的。与潜在的灾难性的经济风险相比,这项花费是微不足道的。自然,价
格并不总是质量可靠的指标,所以购买风速计时,应向有声望的风能研究机构
的人员进行咨询。 The anemometer on a wind turbine is really only used to determine whether
there is enough wind to make it worthwhile to yaw the turbine rotor against the
wind and start it.
风机上的风速计实际上只是用来确定是否有足够的风值得转轮对风进行偏航并
使风机启动。
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Measurement in practice 实际测量
Wind Speed Measurement in Practice 风速的实际测量The best way of measuring wind speeds at a prospective wind
turbine site is to fit an anemometer to the top of a mast which
has the same height as the expected hub height of the wind
turbine to be used. This way one avoids the uncertainty involved in
recalculating the wind speeds to a different height.
在预期的风机场址测量风速的最好方式是在测风塔顶部安装一台测风仪,
测风塔的高度要与风机期望采用的轮毂高度相同。这种方式避免了对于不同高度
重新计算风速的不确定性。By fitting the anemometer to the top of the mast one minimises the
disturbances of airflows from the mast itself. If anemometers are placed on
the side of the mast it is essential to place them in the prevailing wind
direction in order to minimise the wind shade from the tower.
当把测风仪安装在塔架顶部的时候,应尽量减小来自测风塔的湍流的影响。
如果测风仪放在测风塔侧面,重要的是要把它们放在主风向上,以便减小来至
测风塔的风影。Which Tower? 何种测风塔?
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Guyed, thin cylindrical poles are normally preferred over lattice towers for
fitting wind measurement devices in order to limit the wind shade from the
tower.
采用拉线塔,为了安装测风装置在桁架塔的上方通常是一个薄壁柱状杆,
以便限制来至塔架的风影。The poles come as kits which are easily assembled, and you can install such
a mast for wind measurements at (future) turbine hub height without a crane.
几个杆是作为配套元件,很容易装配的。不用吊车你就可以安装一个风机轮
毂高度的测风塔。Anemometer, pole and data logger (mentioned below) will usually cost
somewhere around 5,000 USD.
风速计、杆和数据采集装置(下面介绍)通常成本约 5000
美元。Data Logging 数据采集The data on both wind speeds and wind directions from the
anemometer(s) are collected on electronic chips on a small
computer, a data logger, which may be battery operated for a
long period.
NRG data logger NRG 数据采集器
Soren Krohn 摄 © 1998 DWIA
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来自测风仪的风速和风向数据收集在微处理器的电子芯片上,这就是数据采集
器,它可以靠电池长期工作。An example of such a data logger is shown to the left. Once a month or so
you may need to go to the logger to collect the chips and replace them with
blank chips for the next month's data. (Be warned: The most common mistake
by people doing wind measurements is to mix up the chips and bring the
blank ones back!)
数据采集器的例子如左边所示。大约一个月你需要去数据采集器收取芯片,并用
一个空白芯片替换它,以便储存下个月的数据。(警告:测风时人们常犯的错误
是将已存芯片和空白芯片弄混了,把空白芯片又带回来了!)Arctic Conditions 北极条件If there is much freezing rain in the area, or frost from clouds in mountains,
you may need a heated anemometer, which requires an electrical grid
connection to run the heater.
如果使用地区有大量冻雨,或者山地的云有结霜,你就需要一个带加热器
的风速计。它需要连到电网上,以便使加热器工作。10 Minute Averages 10 分钟平均风速Wind speeds are usually measured as 10 minute averages, in order to be
compatible with most standard software (and literature on the subject). The
result for wind speeds are different, if you use different periods for averaging,
as we'll see later.
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风速通常测量 10分钟平均值,以便同大多数标准软件(以及课程文献)兼
容。如果你用不同期间取平均,风速的结果是不同的,这点以后讲。
The wind rose 风玫瑰图
The Wind Rose (Wind rose from Brest, France, taken from the European
Wind Atlas, Riso National Laboratory, Denmark)
风玫瑰图 (风玫瑰图数据从法国的布雷斯特采集,取自丹麦的 Riso国家
实验室欧洲风能图谱)You will notice that strong winds usually come from a
particular direction, as discussed in the Wind Energy
Resource section.
你会注意到,就像在风能资源一节所讨论的那样,
强风通常来自于某一特定的方向。To show the information about the distributions of wind speeds, and the
frequency of the varying wind directions, one may draw a so-called wind rose
on the basis of meteorological observations of wind speeds and wind
directions.
为了表示风速分布的信息以及风向变化的频率,人们就依据风速和风向的
气象观测数据画一张图,这就是所说的玫瑰图。
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The picture shows the wind rose for Brest, on the Atlantic coast of France.
这张图表明了位于法国大西洋岸边的布雷斯特风玫瑰图。We have divided the compass into 12 sectors, one for each 30 degrees of the
horizon. (A wind rose may also be drawn for 8 or 16 sectors, but 12 sectors
tend to be the standard set by the European Wind Atlas, from which this
image was taken).
我们将这个罗盘分成 12个扇形区域,每一个 30度(风玫瑰图也可以分成
8个或者 16个扇形,但是 12个扇形是欧洲风能图谱的标准组合,这里的玫瑰
图就来至于该图谱。)。The radius of the 12 outermost, wide wedges gives the relative frequency of
each of the 12 wind directions, i.e. how many per cent of the time is the wind
blowing from that direction.
12个最外层半径,及每一区域楔形的宽度给出了 12个风向的相对频度,
也就是说,代表了有多少百分比的时间风从哪个方向吹过来。The second wedge gives the same information, but multiplied by the average
wind speed in each particular direction. The result is then normalised to add
up to 100 per cent. This tells you how much each sector contributes to the
average wind speed at our particular location.
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第二个楔形给出了同类的信息,只是乘上了每一特殊方向上的平均风速。各
扇形的结果相加则规范到百分之百。这告诉我们,每一扇形对这一特定位置平均
风速的贡献。The innermost (red) wedge gives the same information as the first, but
multiplied by the cube of the wind speed in each particular location. The result
is then normalised to add up to 100 per cent. This tells you how much each
sector contributes to the energy content of the wind at our particular location.
最内层楔形(红色)给出了如第一层同类的信息,只是乘上了每一特殊方
向上风速的立方。其结果也可以归为百分之百。这告诉我们,每一扇形对这一特
定位置的风能有多少贡献。Remember, that the energy content of the wind varies with the cube of the
wind speed, as we discussed in the page on The Energy in the Wind. So the
red wedges are really the most interesting ones. They tell us where to find the
most power to drive our wind turbines.
请记住:正如我们在风能一节中所讨论的,风能是随风速的立方而变化。所以,
红楔形实际上是我们最感兴趣的一部分。红色楔形告诉我们,在哪个方向上能发
现最大的功率去驱动我们的风机。In this case we can see that the prevailing wind direction is Southwest, just as
we would have predicted from the page on Global Winds.
36
在这个例子中,我们能够看到主风向为西南,正如我们在全球风那一节所
预测的一样。A wind rose gives you information on the relative wind speeds in different
directions, i.e.each of the three sets of data (frequency, mean wind speed,
and mean cube of wind speed) has been multiplied by a number which
ensures that the largest wedge in the set exactly matches the radius of the
outermost circle in the diagram.
风玫瑰图给我们提供了不同方向上相对风速的信息,即提供了三组数据
(频率,平均风速及风速立方的平均),其中两组都是由第一组乘上某一数而
得。最大楔形精确地同图中的最大外环半径相匹配。Wind Roses Vary 风玫瑰图的变化
Wind roses vary from one location to the next. They
actually are a form of meteorological fingerprint.
从一个位置到另一个位置风玫瑰图是变化的。它
们实际上构成了气象印记。As an example, take a look at this wind rose from Caen, France, only about
150 km (100 miles) North of Brest. Although the primary wind direction is the
same, Southwest, you will notice that practically all of the wind energy comes
from West and Southwest, so on this site we need not concern ourselves very
much about other wind directions.
37
举个例子,看一下法国卡昂哔叽的风玫瑰图,该地点只在布雷斯特北部
150km。尽管主风向西南风是相同的,实际上你会注意到所有的风能都来自西部
和西南部。所以,在这个场址我们不需要太多关心其它风向的变化。Wind roses from neighbouring areas are often fairly similar, so in practice it
may sometimes be safe to interpolate (take an average) of the wind roses
from surrounding observations. If you have complex terrain, i.e. mountains
and valleys running in different directions, or coastlines facing in different
directions, it is generally not safe to make simple assumptions like these.
相邻区域的风玫瑰图往往很相似。所以,实际上从周围观测站中借用风玫瑰
图做些改动(取其平均值)有时是安全的。如果你遇到复杂的地形,即不同走向
的山地和山谷,或者面向不同方向的海岸线,简单地假设借用周围的风玫瑰图
一般是不安全的。The wind rose, once again, only tells you the relative distribution of wind
directions, not the actual level of the mean wind speed.
再说一遍,风玫瑰图只是告诉你风向的相对分布,并不反映平均风速的实
际水平。How to Use the Wind Rose 如何使用风玫瑰图A look at the wind rose is extremely useful for siting wind turbines. If a large
share of the energy in the wind comes from a particular direction, then you will
38
want to have as few obstacles as possible, and as smooth a terrain as
possible in that direction, when you place wind turbines in the landscape.
在风机选址时,看风玫瑰图是极其有用的。如果大部分风能都来至于一个特
定的方向,那么当你在场址布置风机时,就要那个方向上的障碍尽可能少,地
形尽可能平坦。In these examples most of the energy comes from the Southwest. We
therefore need not be very concerned about obstacles to the East or
Southeast of wind turbines, since practically no wind energy would come from
those directions.
在所举例子中,多数风能都来至于西南。因此不需要非常关心风机东部或东
南部的障碍,因为实际上没有多少风能从这些方向来。You should note, however, that wind patterns may vary from year to year, and
the energy content may vary (typically by some ten per cent) from year to
year, so it is best to have observations from several years to make a credible
average. Planners of large wind parks will usually rely on one year of local
measurements, and then use long-term meteorological observations from
nearby weather stations to adjust their measurements to obtain a reliable long
term average.
但是应当注意,风图谱每年可能有变化,风能也就有变化(典型情况变化 10%
左右)。因此,最好要从测风几年的观察站得到一个可以信赖的平均值。大型风
39
场的规划者通常依靠一年的局域测风,然后使用附近气象站的长期气象观测数
据来调整他们自己的测量数据,以便获得可靠的长期平均值。Since this wind rose comes from the European Wind Atlas we are reasonably
confident that we can rely on it. The European Wind Atlas contains a
description of each of the measurement stations, so we may be warned about
possible local disturbances to the airflow. On the page on selecting a wind
turbine site, we return to the pitfalls in using meteorology data.
因为这一风玫瑰图取自欧洲风能图谱,我们有理由确信它是可靠的。欧洲风
能图谱包含有每一测站的描述,所以对气流可能有的局部扰动我们会给予提醒。
在选择风机场址那一节,我们重温一下使用气象数据的陷阱。
Draw a wind rose 画风玫瑰图
Wind Rose Plotter Programme CALCULATOR
风玫瑰画图程序——计算器Plot your own wind rose 画你自己的风玫瑰图Do not operate the form until this page and its programme have loaded
completely.
阅读了这一节并完整安装了程序之后,再操作这里的表格。The explanation of the wind rose may be found on the previous page. The
Wind Frequency is the percentage of the time the wind is coming from a
particular direction. The first row in the table to the left corresponds to North
40
(the top wedge). The subsequent rows correspond to the sectors of the wind
rose in a clockwise direction.
风玫瑰图的解释可以在前一节中找到。风频是从特定方向来风的时间的百分
比。左边表格第一排相当于北(楔形顶部)。随后各排按顺时针方向对应于风玫
瑰图的相应扇形。Wind Frequency Mean wind speed
风频 平均风速
Use Sectors. data. to Copenhagen data.
采用 扇形 数据 至哥本哈根数据Show wind frequency.
显示风频Show wind speed.
显示风速
Show wind energy.
显示风能For each of the sectors the outermost (blue) wedges show the wind
frequency distribution.
对于每一个扇形,最外面的(蓝色)楔形表示风频的分布The middle (black) wedges show the distribution of the product of the two
columns, i.e. the wind speeds times their frequency.
中间的(黑色)楔形表示两栏之积的分布,即风速乘以其风频的分布。The innermost (red) wedges show the distribution of the wind speeds
cubed (i.e. the energies) multiplied by their frequencies.
41
最里面的(红色)楔形表示风速的立方(即风能)乘以其风频的分布。To print the results of the plotter programme you should make a screen dump.
为了打印绘图程序的结果,你应当进行屏幕转存。Wind frequency
风频Mean wind speed 平均风速
42
Turbine sitin 风机选址
Roughness & shear 粗糙度与风剪切
Roughness and Wind Shear 粗糙度与风剪切High above ground level, at a height of about 1 kilometre, the wind is hardly
influenced by the surface of the earth at all. In the lower layers of the
atmosphere, however, wind speeds are affected by the friction against the
surface of the earth. In the wind industry one distinguishes between the
roughness of the terrain, the influence from obstacles, and the influence from
the terrain contours, which is also called the orography of the area. We shall
be dealing with orography, when we investigate so called speed up effects,
i.e. tunnel effects and hill effects, later.
在高于地表 1km的高处,风几乎不受地表的影响。但是,在大气的低层,风速
受地表摩擦的影响。在风能界,人们对地形的粗糙度加以区别,考虑障碍物的影
响和地形的影响,这也称为该地区的山地形态学。当研究风的加速效应时,也就
是以后讲的风洞效应和山地效应,我们就会涉及到山地形态学。Roughness 粗糙度 In general, the more pronounced the roughness of the earth's surface, the
more the wind will be slowed down.
一般说来,地表粗糙度越大,风速降低得也就越多。
43
Forests and large cities obviously slow the wind down considerably, while
concrete runways in airports will only slow the wind down a little. Water
surfaces are even smoother than concrete runways, and will have even less
influence on the wind, while long grass and shrubs and bushes will slow the
wind down considerably.
显然,森林和大城市会使风速很快下降,而机场的混凝土跑道只使风速稍有下
降。水面比混凝土跑道更光滑,对风速会有更小的影响,而长高的草、灌木和树
丛也会使风速显著下降。roughness classes & roughness lengths 粗糙度等级和粗糙尺度
Sheep are a wind turbine's best friend. In this picture from Akaroa Spit, New Zealand,
the sheep keep the roughness of the landscape down through their grazing.
Photograph Soren Krohn© 1998 DWIA
羊是风机最好的朋友。这张图片来自新西兰的Akaroa Spit,羊吃草保持了地貌粗糙度下降。
Soren Krohn 摄In the wind industry, people usually refer to roughness classes or roughness
lengths, when they evaluate wind conditions in a landscape. A high roughness
class of 3 to 4 refers to landscapes with many trees and buildings, while a sea
surface is in roughness class 0.
在风能界,当人们评估某一地貌风况时,通常要提及粗糙度等级或粗糙尺度。对
于有很多树和建筑物的地貌,粗糙度等级从 3到 4,海面的粗糙度等级为 0。
44
Concrete runways in airports are in roughness class 0.5. The same applies to
the flat, open landscape to the left which has been grazed by sheep.
The proper definition of roughness classes and roughness lengths may be
found in the Reference Manual. The term roughness length is really the
distance above ground level where the wind speed theoretically should be
zero.
机场的混凝土跑道粗糙度等级是 0.5。平坦的开阔地到被羊吃光的草地都具有同
样的粗糙度等级。
粗糙度等级和粗糙尺度的合适定义可以从参考手册中查出。粗糙尺度实际就是高
于地面的距离,地面的风速理论上应该为零。Wind Shear 风剪切
This graph was plotted with the wind speed calculator on the next page. It
shows you how wind speeds vary in roughness class 2 (agricultural land with
some houses and sheltering hedgerows with some 500 m intervals), if we
assume that the wind is blowing at 10 m/s at a height of 100 metres.
45
这张图用下一页讲的风速计算器画的。如果我们假设在 100米高度风速是 10
m/s,计算器向你演示粗糙度等级为 2时(间隔 500m有房子和篱笆墙的农用土
地),风速是如何变化的。The fact that the wind profile is twisted towards a lower speed as we move
closer to ground level, is usually called wind shear. Wind shear may also be
important when designing wind turbines. If you consider a wind turbine with a
hub height of 40 metres and a rotor diameter of 40 metres, you will notice that
the wind is blowing at 9.3 m/s when the tip of the blade is in its uppermost
position, and only 7.7 m/s when the tip is in the bottom position. This means
that the forces acting on the rotor blade when it is in its top position are far
larger than when it is in its bottom position.
当我们从高处移向地面的时候,风剖面向低风速扭曲,通常把这一事实称为风
剪切。当设计风机时,风剪切也很重要。如果你考虑轮毂高度和转轮直径都是
40m的一台风机,你会注意到,当叶尖处于最高位置时风速是 9.3 m/s,当叶
尖处于最低位置时风速只有 7.7 m/s。这就意味着,最高位置上转轮叶片的作用
力远大于最低位置上转轮叶片的作用力。Wind Shear Formula *) 风剪切公式*)The wind speed at a certain height above ground level is:
地面上某一高度处的风速为:
46
v = vref ln(z/z 0 )/ln(zref /z 0 )
v = wind speed at height z above ground level.
v =地面上方高度 z处的风速v ref = reference speed, i.e. a wind speed we already know at height z ref . ln(...)
is the natural logarithm function.
v ref =参考风速,即已知的高度 z ref处的风速;ln(...)是自然对数函数。z = height above ground level for the desired velocity, v.
z =期望风速 v的高度值。 z 0 = roughness length in the current wind direction.
z 0 =当前风向的粗糙尺度。Roughness lengths may be found in the Reference Manual.
粗糙尺度可以从参考手册中查到。zref = reference height, i.e. the height where we know the exact wind speed v ref
.
zref =参考高度,也就是说,我们已知精确风速 vref处的高度。In the above example, assume we know that the wind is blowing at 7.7 m/s at
20 m height. We wish to know the wind speed at 60 m height. If the
roughness length is 0.1 m, then
47
在上例中,假定我们已知在 20m高处风速为 7.7 m/s。我们期望知道 60m高处
的风速。如果粗糙尺度为 0.1m,则有v ref = 7.7
z = 60
z 0 = 0.1
z ref = 20 hence,
z ref = 20 因此,v = 7.7 ln(60/0.1) / ln(20/0.1) = 9.2966 m/s
*) = The formula assumes so-called neutral atmospheric stability conditions,
i.e. that the ground surface is neither heated nor cooled compared to the air
temperature. Further details may be found in the engineering handbook
Guidelines for Design of Wind Turbines from Risoe National Laboratory and
DNV.
公式假定具备大气中性稳定的条件,也就是说,与空气温度比较,地表面既不被加热也不被冷却。详情可在名为风机设计导则的工程设计手册中查出,该手册来源于 Risoe国家实验室和DNV。(Sheep are a wind turbine's best friend. In this picture from Akaroa Spit, New
Zealand, the sheep keep the roughness of the landscape down through their
grazing. Photograph Soren Krohn
© 1998 DWIA)
(羊是风机的好朋友。这张图片来自新西兰的 Akaroa Spit,通过羊的取食保持
着地面的粗糙度,Soren Krohn拍摄)
48
Speed calculation 速度计算
Wind Speed Calculator 风速计算器Do not operate the form until this page and its programme have loaded
completely.
学习了这一页并完整地安装了计算程序之后,才能操作这一表格。Enter your wind speed measurement in any column at the appropriate height,
e.g. 10 metres. Then click outside the field, click Submit, or use the tab key.
The programme will then calculate wind speeds for other heights. You may
plot your results in a separate window by clicking on Plot in the appropriate
column. (If the plot window disappears, it is probably hidden behind this
window).
在适当的高度,比如 10m,在任意栏内填入你的风速测量值。然后,在场外单
击,单击 Submit,或者使用表格键。随后,程序将计算其他高度的风速。在相应
的栏里单击 Plot,你可以在一个单独的窗口画出你的结果。(如果画图的窗口不
见了,它或许隐藏在这一窗口的后面)。CALCULATOR计算器
Roughness粗糙度- class等级- length m尺度 m
0.0 0.0002
0.5 0.0024
1.0 0.03
1.5 0.055
2.0 0.1
3.0 0.4
4.0 1.6
150 m
49
140 m
130 m
120 m
110 m
100 m
90 m
80 m
70 m
60 m
50 m
40 m
30 m
20 m
10 m
Plot Plot Plot Plot Plot Plot Plot Calculate Clear Use example Data
计算 清除 实例 数据
Average wind speeds are often available from meteorological observations
measured at a height of 10 metres. Hub heights of modern 600 to 1,500 kW
wind turbines are usually 40 to 80 metres, however. The spreadsheet will
calculate average wind speeds at different heights and roughness classes.
Just enter a wind speed measured at a certain height for a given roughness
class and click the Submit button.
50
10m高的平均风速往往可以从气象台获得。但是,现代 600 到 1,500 kW风机的
轮毂高度通常为 40 到 80 m。电子数据表用于计算不同高度的平均风速和粗糙
等级。在给定粗糙等级下输入某一高度测得的风速,然后单击 Submit按钮。Please note, that the results are not strictly valid if there are obstacles close to
the wind turbine (or the point of meteorological measurement) at or above the
specified hub height. ["close" means anything up to one kilometre].
请注意,如果有等于或者高于指定轮毂高度的障碍物接近风机(或气象测点)
时,那些结果并不严格有效。[“接近”意味着 1km以内的距离]
You should also note that there may be inverse wind shear on hilltops
because of the hill effect, i.e. the wind speed may actually decline with
increasing height during a certain height interval above the hilltop. You should
consult the European Wind Atlas mentioned in the bibliography in the
Reference Manual for further information on this phenomenon.
还应当注意,因为山丘效应在山顶可能有反向风剪切。这就是说,在山顶上某一
高度间隔内,风速实际上可能随高度的增加而下降。你应当查阅参考手册的文献
得到这一现象的进一步信息,欧洲风能图谱提到参考手册的这一文献。Take a look at the example below the table to make sure you understand how
it works, before you start entering your data. More accurate and extensive
roughness definitions may be found in the units section.
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看下面的例子,在你开始输入数据之前,让你理解这个表格是如何工作的。更精
确和广泛的粗糙度定义可以在“单位”这节找到。An Example 一个例子As an example, have a look at the spreadsheet above. We have already
entered 10 m/s at 100 m height in roughness class 2. You will notice that the
wind speed declines as you approach ground level. You will also notice that it
declines more rapidly in rough terrain.
举个例子,看一下上面的电子数据表。在粗糙等级为 2,高 100m时,我们已经
输入 10 m/s。你会注意到,当接近地面时风速会下降。你同时也注意到,在粗糙
的地面风速会下降得更快。Remember that the energy content of the wind varies with the third power of
the wind speed. If you look at the column with roughness class 2, you will see
that wind speeds declines 10 per cent going from 100 metres to 50 metres.
But the power of the wind declines to 0.9 3 = 0.73, i.e. by 27 per cent. (From
613 to 447 W/m 2).
记住:风能随风速的三次方而变化。如果你观察粗糙度为 2的那栏,你会看到当
高度从 100m降到 50m的时候,风速下降 10%。但是风功率下降到 0.9 3 =
0.73,即下降了 27%(从 613到 447 W/m 2)。
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If you compare the wind speeds below 100 m in roughness class 2 with
roughness class 1, you will notice that for a given height the wind speeds are
lower everywhere in roughness class 2.
如果在 100m以下高度,将粗糙度为 2与粗糙度为 1进行比较,你会注意到对
于给定的高度,粗糙度等级为 2的每个地方风速都较低。If you have a wind turbine in roughness class 2, you may consider whether it
is worthwhile to invest 15,000 USD extra to get a 60 metre tower instead of a
50 metre tower. In the table you can see that it will give you 2.9 per cent more
wind, and you can calculate, that it will give you 9 per cent more wind energy.
如果你在粗糙度等级为 2的地方安装风机,你可能考虑气象条件值得多投资
15000 美元安装 60米塔架以代替 50米塔架。在表中你能看到将多获得 2.9%的
风速,你能计算出将多获得 9%的风能。You can solve this problem once you have learned how the turbine electricity
production varies with the available wind energy. We will return to that
question when you have learned to use the power density calculator and the
wind energy economics calculator.
一旦你学习了风电如何随可利用的风能而变化,你就能解决这一问题。当你学习
了使用功率密度计算器和风能经济计算器,我们再回到那个问题上。Now, try the calculator for yourself.
现在你自己试着使用计算器。
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Escarpments 陡坡
Wind Shear and Escarpments风剪切和陡坡
(Aerial photograph
Soren Krohn
© 1999 DWIA)(航空摄影 Soren
Krohn © 1999 DWIA)
Do not Include the Altitude of Your Terrain in Wind Shear Calculations 在风剪切计算中不包括你所在地形的高度The aerial photograph above shows a good site for wind turbines along a
shoreline with the turbines standing on a cliff which is about 10 m (30 ft.) tall.
It is a common mistake to believe that in this case one may add the height of
the cliff to the height of the wind turbine tower to obtain the effective height of
the wind turbine, when one is doing wind speed calculations, at least when
the wind is coming from the sea.
上面航空摄影表明一处好的风机场址,风机沿着海岸线布置,并立在约 10m高
的悬崖上。通常错误地相信,当你做风速计算时,至少当风从海上来时,你可能
把悬崖的高度加到风机塔架的高度上去,以便获得有效的风机高度。
54
This is patently wrong. The cliff in the front of the picture will create
turbulence, and brake the wind even before it reaches the cliff. It is therefore
not a good idea to move the turbines closer to the cliff. That would most likely
lower energy output, and cause a lower lifetime for the turbines, due to more
tear and wear from the turbulence.
这显然是一个的错误。前面图片中的悬崖将产生湍流,而且在风到达悬崖之前阻
止了风前进。因此,把风机靠近悬崖安装不是好主意。这会导致输出能量降低,
由于湍流产生更大的拉伤力和磨损,也使风机寿命降低。If we had the choice, we would much rather have a nicely rounded hill in the
direction facing the sea, rather than the escarpment you see in the picture. In
case of a rounded hill, we might even experience a speed up effect, as we
explain later when we get to the page on the hill effect.
如果让我们选择,我们会让风机在迎海的方向沿着山丘合理布置,而不是布置
在图片所示的陡坡上。对于沿山丘布置的案例,我们甚至有使风加速的山丘效应
的经验。当我们进入山丘效应这一节,会对此作出解释。
The roughness rose 粗糙度玫瑰图
The Roughness Rose 粗糙度玫瑰图If we have measured the wind speed exactly at hub height
over a long period at the exact spot where a wind turbine will
be standing we can make very exact predictions of energy
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production. Usually, however, we have to recalculate wind measurements
made somewhere else in the area. In practice, that can be done with great
accuracy, except in cases with very complex terrain (i.e. very hilly, uneven
terrain).
如果已经精确地确定一台风机的机位,并在机位上测出轮毂高度的长期的风速,
我们就能精确地预测风能输出。不过,通常对于该区域的其他地方,我们必须对
测风进行重新计算。事实上,这个工作也能做得很精确,除非遇到很复杂的地形
(即起伏非常大、不平坦的地形)。Just like we use a wind rose to map the amount of wind energy coming from
different directions, we use a roughness rose to describe the roughness of the
terrain in different directions from a prospective wind turbine site.
正如我们用风玫瑰图标出来至不同方向的风能一样,我们也用粗糙度玫瑰图来
描述未来风机场址不同方向的地形粗糙度。Normally, the compass is divided into 12 sectors of 30 degrees each, like in
the picture to the left, but other divisions are possible. In any case, they
should match our wind rose, of course.
通常,罗盘分成 12个扇形,每个 30度,如左图所示。但是,其他分法也是可能
的。当然,在任何情况下这些分法应当与风玫瑰图相匹配。For each sector we make an estimate of the roughness of the terrain, using
the definitions from the Reference Manual section. In principle, we could then
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use the wind speed calculator on the previous page to estimate for each
sector how the average wind speed is changed by the different roughness of
the terrain.
利用参考手册给出的粗糙度定义,我们对每一个扇形的地形粗糙度做出估计。然
后,原则上我们能够使用前节介绍的风速计算器来估计每一扇形的平均风速是
如何随着不同的地形粗糙度而变化的。Photograph Soren Krohn,
© 1999 DWIA
Averaging Roughness in Each Sector 每一扇面的平均粗糙度In most cases, however, the roughness will not
fall neatly into any of the roughness classes, so
we'll have to do a bit of averaging. We have to
be very concerned with the roughness in the
prevailing wind directions. In those directions we look at a map to measure
how far away we have unchanged roughness.
但是,在多数情况下粗糙度不会准确地归为某一个粗糙度等级,所以必须进行
平均,我们应当更关心主风向的粗糙度。在这些方向上我们看图测量出,不变的
粗糙度离实际场址有多远。
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Accounting for Roughness Changes Within Each Sector在每个扇形内考虑粗糙度的变化Let us imagine that we have a sea or lake surface in the western sector (i.e.
roughness class 0) some 400 m from the turbine site, and 2 kilometres away
we have a forested island. If west is an important wind direction, we will
definitely have to account for the change in roughness class from 1 to 0 to 3.
我们设想,风场西部 400m有海或湖面,再往西 2km有一片森林覆盖的岛屿。
如果西风是主风向,我们肯定要考虑粗糙度等级的变化,由 1到 0再到 3。This requires more advanced models and software than what we have shown
on this web site. It is also useful to be able to use the software to manage all
our wind and turbine data, so at a future update of this site we'll explain how
professional wind calculation software works.
这就需要比我们网址所示的更为先进的模型和软件。同时,利用软件来管理所有
的风能和风机数据也是必要的,所以,将来这个站址升级后我们将解释专业的
风能计算软件是如何工作的。Meanwhile, you may look at the Links page to find the link to Risoe's WAsP
model and Energy & Environmental Data's WindPro Windows-based
software.
同时,你可以浏览一下链接页,找到 Risoe's WAsP模型和能源环境数据的
WindPro的链接,这些都是运行在Windows平台下的。Accounting for Wind Obstacles 考虑风的障碍物
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It is extremely important to account for local wind obstacles in the prevailing
wind direction near the turbine (closer than 700 m or so), if one wants to make
accurate predictions about energy output. We return to that subject after a
couple of pages.
如果人们想精确地预测风能的输出,考虑在风机附近(靠近风机约 700m)主
风向上的局部风障碍物是极端重要的。几节之后我们回到这个话题。
Variable winds 可变风
Wind Speed Variability 风速的可变性Short Term Variability of the Wind 风速的短期可变性The wind speed is always fluctuating, and
thus the energy content of the wind is always
changing.
风速总是波动的,因此风能也总要有变化。Exactly how large the variation is depends
both on the weather and on local surface
conditions and obstacles.
精确说出有多大变化,这取决于风况、当地表面条件和障碍物。Energy output from a wind turbine will vary as the wind varies, although the
most rapid variations will to some extent be compensated for by the inertia of
the wind turbine rotor.
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风机的能量输出随风而变化,尽管最急剧的变化将在一定程度上被风机转轮的
惯性所补偿。Diurnal (Night and Day) Variations of the Wind 风的日(夜间与百天)变化
In most locations around the globe it is more
windy during the daytime than at night. The
graph to the left shows how the wind speed at
Beldringe, Denmark varies by 3 hour intervals
round the clock. (Information from the European
Wind Atlas).
全球多数地方,白天比夜间风大。左图表明丹麦 Beldringe镇 3小时间隔风速的
变化(信息来自于欧洲风能图谱)。This variation is largely due to the fact that temperature differences e.g.
between the sea surface and the land surface tend to be larger during the day
than at night. The wind is also more turbulent and tends to change direction
more frequently during the day than at night.
由于温差大,风速变化是很大的,例如,海洋和陆地表面间的温差,白天比夜
间要大。同时,风也更紊乱,白天比夜间改变方向更频繁。From the point of view of wind turbine owners, it is an advantage that most of
the wind energy is produced during the daytime, since electricity consumption
is higher than at night. Many power companies pay more for the electricity
produced during the peak load hours of the day (when there is a shortage of
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cheap generating capacity). We will return to this subject in the section on
Wind Turbines in the Electrical grid.
对于风机业主来说,由于白天的电耗比夜间高,白天可以生产更多的风能,这
是优点。许多电网公司花更多的钱买白天峰值负荷期间生产的电(当便宜的发电
容量短缺的时候)。在电网中的风机这一部分,我们再回到这一专题。Seasonal Variations of the Wind 风的季节变化We treat this subject in the section on Wind Turbines in the Electrical grid.
在电网中的风机这一部分,我们讨论这一专题。
Turbulence 湍流
Turbulence 湍流You have probably experienced how
hailstorms or thunderstorms in particular, are
associated with frequent gusts of wind which
both change speed and direction.
你或许经历过冰雹或者是暴风雨,它们都是与
频繁的阵风相联系的,这种风的风速和方向都
随时改变。
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In areas with a very uneven terrain surface, and behind obstacles such as
buildings there is similarly created a lot of turbulence, with very irregular wind
flows, often in whirls or vortexes in the neighbourhood.
在一个地形起伏的地区以及障碍物之后,比如建筑物后也会产生类似的湍流。这
种很不规则的风的流动,常常在邻近形成涡流或漩涡。You can see an example of how turbulence increases the fluctuations in the
wind speed in the image, which you may compare with the image on the
previous page.
你可以看到一个例子,在图像中湍流是如何增加了风速的扰动。你可以将这张图
像同前节的图像进行比较。Turbulence decreases the possibility of using the energy in the wind
effectively for a wind turbine. It also imposes more tear and wear on the wind
turbine, as explained in the section on fatigue loads. Towers for wind turbines
are usually made tall enough to avoid turbulence from the wind close to
ground level.
湍流减少了风力发电中风能有效利用的可能性。它也加速了风机的拉伤和磨损,
形成了本节所解释的疲劳载荷。风机塔架通常要足够高,以避免来自接近地面的
风形成的湍流。
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Wind obstacles 风障碍物
Wind Obstacles 风障碍物This movie was shot at a coastal wind site with the wind coming from the right
side of the picture. It shows an interesting phenomenon:
这部电影演示了沿海风场,风从图片的右侧刮来。它展示了一段很有趣的现象:
We would really expect the wind turbine to the right (which is facing the wind
directly) to be the one to start first when the wind starts blowing. But you can
see, that the wind turbine to the right will not start at the low wind speeds
which are sufficient to drive the other two wind turbines. The reason is the
small wood in front of the wind turbines which shelters the rightmost turbine in
particular. In this case, the annual production of these wind turbines is
probably reduced by some 15 per cent on average, and even more in case of
the rightmost turbine.
实际上,当风吹过来的时候,预期右边的风机(它直接面对来风)首先启动。但
是你看到,在低风速下右边的风机没有启动,这种低风速足以驱动另两台风机。
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原因是在特定的情况下,风机前的小树遮挡了最右侧的风机。在这种情况下,风
机的年产电量或许平均减少 15%,对于最右边的风机甚至于减少得更多。(The turbines are located some five rotor diameters apart, and the wood is
located at a similar distance from the first wind turbine. The reason why the
turbines look like they are standing very close together, is that the movie was
shot from about a mile away with the equivalent of a 1200 mm lens for a 35
mm camera).
(风机的间距约 5倍转轮直径,而树木所处位置离第一台风机差不多也是这个
距离。为什么风机看起来排列得很近,因为电影是从 1英里以外拍的,对于
35mm的相机相当于用了 1200mm的镜头)。Side view of wind flow
around an obstacle. Note the pronounced turbulent airflow
downstream 风绕过障碍物流动的侧视图。
注意:下游显然有湍流Obstacles to the wind such
as buildings, trees, rock formations etc. can decrease wind speeds
significantly, and they often create turbulence in their neighbourhood.
风的障碍物,诸如建筑物,树木,岩石的排布等都能显著降低风速,并且在他
们的临近常常产生湍流。
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As you can see from this drawing of typical wind flows around an obstacle, the
turbulent zone may extend to some three time the height of the obstacle. The
turbulence is more pronounced behind the obstacle than in front of it.
从典型的风绕流障碍物的图你可以看到,湍流区域可以扩展到障碍物高度的 3
倍。湍流在障碍物后比障碍物前更显著。Therefore, it is best to avoid major obstacles close to wind turbines,
particularly if they are upwind in the prevailing wind direction, i.e. "in front of"
the turbine.
因此,最好要避免主要的障碍物接近风机,特别是如果他们在主风向上游,也
就是在风机前面更要注意。Top view of wind flow around an
obstacle
风扰流障碍物的顶视图
Shelter Behind Obstacles 障碍物后的屏蔽Obstacles will decrease the wind speed downstream from the obstacle. The
decrease in wind speed depends on the porosity of the obstacle, i.e. how
"open" the obstacle is. (Porosity is defined as the open area divided by the
total area of the object facing the wind).
障碍物将降低其下游的风速。风速的降低取决于障碍物的孔隙率,也就是说障碍
物有多大的“开度”。(孔隙率定义为迎风物体敞开的面积除以它的总面积。)
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A building is obviously solid, and has no porosity, whereas a fairly open tree in
winter (with no leaves) may let more than half of the wind through. In summer,
however, the foliage may be very dense, so as to make the porosity less than,
say one third.
显然,建筑物是实心的没有孔隙率,而冬天适当张开的树(无树叶)能让超过
一半的风通过。但是在夏天树的枝叶可能很稠密,所以造成较低的孔隙率,比如
说三分之一。The slowdown effect on the wind from an obstacle increases with the height
and length of the obstacle. The effect is obviously more pronounced close to
the obstacle, and close to the ground.
扰流障碍物风的下降效应随着障碍物的高度和长度而增加。越接近障碍物、越接
近地面,这种效应越明显。When manufacturers or developers calculate the energy production for wind
turbines, they always take obstacles into account if they are close to the
turbine - say, less than 1 kilometre away in one of the more important wind
directions.
当制造商或发展商计算风机产能的时候,如果障碍物靠近风机,比如说在某一
重要的风向上障碍物距风机低于 1km, 他们总会把障碍物考虑进去。
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Wind shade 风影
Wind Shade 风影
This graph gives you an estimate of how wind speeds decrease behind a
blunt obstacle, i.e. an obstacle which is not nicely streamlined. In this case we
use a seven story office building, 20 metres tall and 60 metres wide placed at
a distance of 300 m from a wind turbine with a 50 m hub height. You can quite
literally see the wind shade as different shades of grey. The blue numbers
indicate the wind speed in per cent of the wind speed without the obstacle.
该图让你估计出,在一个显著的障碍物,也就是说在非流线型的障碍物之后风
速有多少降低。在这个案例,我们利用七层办公大楼,20m高,60m 宽放在距
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风机 300m处,风机的轮毂高度 50m。你们能真正地看到以不同的灰影表示的
风影。蓝色的号码表示风速,它以没有障碍物风速的百分比表示。At the top of the yellow wind turbine tower the wind speed has decreased by
some 3 per cent to 97 per cent of the speed without the obstacle. You should
note that this means a loss of wind energy of some 10 per cent, i.e. 1.03 3 - 1,
as you may see in the graph at the bottom of this page.
在黄色风机塔架的顶部,风速约降低 3%,即降到无障碍风速的 97%。你应当注
意,这意味着 10%的风能损失,即 1.03 3 – 1,如该页底部的图所示。If you have a reasonably fast computer (or a bit of patience with a slower one)
you can plot tables and graphs like this one using the wind shade calculator in
a couple of pages.
如果你有一台相当快的电脑(或者电脑慢但你有耐心),你就能使用下几页介
绍的风影计算器画出这样的表格和图来。
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Calculator guide 计算器指南
Guide to the Wind Shade Calculator 风影计算器入门The calculator will quickly give you the result at hub height at the distance
from the obstacle you specify. If you use the plot facility, your computer will
also calculate 620 different measurement points at different heights and
distances from your obstacle.
在你已经说明轮毂高度和至障碍物的距离后,计算器会很快地给出结果。如果你
使用画图设备,电脑将计算出不同高度和到障碍物不同距离的 620个不同的测
点。Turbine Hub Height 风机的轮毂高度
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The higher you are above the top of the obstacle, the less wind shade. The
wind shade, however, may extend to up to five times the height of the
obstacle at a certain distance.
离障碍物顶部越高,风影越小。但是,在某一距离上风影可以扩展到障碍物高度
的 5倍。If the obstacle is taller than half the hub height, the results are more uncertain,
because the detailed geometry of the obstacle, (e.g. differing slopes of the
roof on buildings) will affect the result. In that case the programme will put a
warning in the text box below the results.
如果障碍物高于轮毂高度的一半,结果更不确定,因为障碍物详细的几何形状
(如建筑物顶部的不同的斜面)会影响这一结果。在那种情况下,程序将在结果
下面放一个警示盒。Distance Between Obstacle and Turbine 障碍物和风机间的距离The distance between the obstacle and the turbine is very important for the
shelter effect. In general, the shelter effect will decrease as you move away
from the obstacle, just like a smoke plume becomes diluted as you move
away from a smokestack. In terrain with very low roughness (e.g. water
surfaces) the effect of obstacles (e.g. an island) may be measurable up to 20
km away from the obstacle.
障碍物和风机间的距离对于风影效应是很重要的。一般说来,风影效应随至障碍
物距离的增加而降低。正如烟离开烟囱之后,烟羽逐渐被冲淡一样。在低粗糙度
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地带(比如水面),障碍物(比如一个岛屿)的效应可以测到从障碍物开始
20km远。If the turbine is closer to the obstacle than five times the obstacle height, the
results will be more uncertain, because they will depend on the exact
geometry of the obstacle. In that case the programme will put a warning in the
text box below the results.
如果风机接近障碍物,在障碍物高度的 5倍距离以内,结果就更为不确定,这
要取决于障碍物的精确的几何形状。在那种情况下,程序将在结果下面的文本内
提出警示。Roughness Length or Roughness Class 粗糙尺度或粗糙等级The roughness of the terrain between the obstacle and the wind turbine has
an important influence on how much the shelter effect is felt. Terrain with low
roughness will allow the wind passing outside the obstacle to mix more easily
in the wake behind the obstacle, so that it makes the wind shade relatively
less important.
障碍物和风机之间地形的粗糙度对于风影效应的多寡有重要的影响。低粗糙度地
形允许风通过障碍物外边,在障碍物后边更容易混合后还原,这样使风影就显
得不那么重要了。It may be a bit confusing at first, that we both deal with the roughness of the
terrain, and with individual obstacles. A good rule of thumb is that we deal
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with individual obstacles which are closer than about 1000 metres from the
wind turbine in the prevailing wind directions. The rest we deal with as
changes in roughness classes.
起初可能有点混淆,我们既涉及了地形的粗糙度,也讨论了单独的障碍物。一条
好的规则是优先考虑在主风向上距风机 1000m以内的独立的障碍物。然后我们
再考虑粗糙度等级的变化。Obstacle Height 障碍物高度The taller the obstacle, the larger the wind shade.
障碍物越高,风影越大。As we have mentioned above, if the turbine is closer to the obstacle than five
times the obstacle height, or if the obstacle is taller than half the hub height,
the results will be more uncertain, because they will depend on the exact
geometry of the obstacle. In that case the programme will put a warning in the
text box below the results.
上面已经提到,如果风机在障碍物高度的 5倍距离以外,或者说如果障碍物高
于风机轮毂高度的一半,结果是很不确定的。因为这取决于障碍物的精确的几何
形状。在那种情况下,程序将在结果下面的文本内提出警示。Obstacle Width 障碍物的宽度The obstacle calculation model works on the basis of the assumption that
obstacles are infinitely long, and that they are placed at a right angle
(perpendicular) to the wind direction.
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障碍物的计算模型是基于这样的假设:障碍物无限长,并且把它们放在与风向
垂直的位置上。A very narrow object will of course cast a far smaller wind shade than a large
one. For practical reasons we assume that we investigate the horizon around
the wind turbine in twelve 30 degree sections.
当然,一个很窄的物体比起大的物体产生非常小的风影。从实际出发我们假设,
考察一个围绕风机的水平面,分成 12个 30度的扇面。At the bottom of the drawing on the right side of the wind shade calculator we
illustrate (in 10 per cent steps) how much space the obstacle take up in such
a 30 degree section. You may adjust the width of the obstacle in 10 per cent
steps by clicking on the squares at the bottom of the graph.
在风影计算器右侧的图片的底部,我们阐明了(以 10个百分步为单位)在那个
30度的扇面里,障碍物占去了多少空间。点击该图底部的方块,我们可以以 10
个百分步为单位调节障碍物的宽度。You may also type the exact length of the obstacle (as seen from the wind
turbine) directly, or you may enter the percentage of the sector width that the
object fills up.
你可以直接键入精确的障碍物的长度(恰如从风机可看到的),或者输入物体
充满扇面宽度的百分数。
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Porosity 孔隙率= 0% = 30% = 50% = 70%
A tree without leaves will brake the wind far less than a building. Trees with
dense foliage will have a braking effect somewhere in between. In general,
the wind shade will be proportional to (one minus the porosity of the obstacle).
没有叶子的树对风的阻挡远低于建筑物。枝叶繁茂的树对风有阻挡效应。一般说
来,风影将与障碍物的孔隙率成反比。The porosity of an obstacle is a percentage indication of how open an
obstacle is, i.e. how easily the wind can pass through it. A building obviously
has a zero porosity. A group of buildings with some space between them with
have a porosity equal to (the area of the open space) divided by (the total
area of both buildings and the open space in between, as seen from the wind
turbine).
孔隙率是障碍物开放程度的百分数,也就是说,风通过障碍物的容易程度。显然
一栋建筑物的孔隙率为零。具有间距的一组建筑物其孔隙率等于,间距的面积除
以建筑物面积和其间距面积的总和,正如由风机所看到的。You may either specify the porosity directly in the calculator, click on one of
the buttons with the symbols shown above, or use the pop up menu for
suggested settings for different objects.
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借助于上面标明的符号,单击一个按钮,你可以用计算器直接指定孔隙率。或者
使用弹出的菜单,对于不同的物体给出建议的设置。
Control Buttons 控制按钮Submit calculates your latest input. You may use the tab key or just click
outside the field you change instead.
建议计算你的最新输入。你可以使用表格键,或者就单击你变化的区域外以代替
上述操作。Plot Wind Speed gives you a graph and a table of the percentage of the
remaining wind speed at a number of heights and distances up to 1.5 times
the height and distance of your wind turbine hub. The turbine tower is shown
in yellow. The calculations are quite complex, so be patient if your computer is
slow.
标出风速,在若干高度和距离上给你提供一张图和一个剩余风速百分比的表,
高度以及轮毂间的距离可扩展至 1.5倍。风机塔架以黄色表示。计算是很复杂的
如果你的电脑速度慢,一定要耐心。Plot Wind Energy gives you a graph and a table of the percentage of the
remaining wind energy at a number of heights and distances up to 1.5 times
the height and distance of your wind turbine hub. The turbine tower is shown
in yellow. The calculations are quite complex, so be patient if your computer is
slow.
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标出风能,在若干高度和距离上给你提供一张图和一个剩余风能百分比的表,
高度以及轮毂间的距离可扩展至 1.5倍。风机塔架以黄色表示。计算是很复杂的
如果你的电脑速度慢,一定要耐心。Plot Speed Profile gives you a plot of the wind speed profile at different
heights up to 100 m at the distance where you have placed your turbine. You
can see directly on the red curve how the obstacle makes the wind speed
drop. You can enter any wind speed you like for the hub height. (The shape of
the curve remains the same, which is should, since obstacles cause a relative
change in wind speed). The curve corresponds to the curves drawn by the
wind speed calculator.
绘出风速剖面,给你提供一个不同高度上风速剖面的细节,直到距你安装风机
100m处。你可能直接看到,红色曲线标明障碍物是如何使风速下降的。你可以
输入你在轮毂高度上想要的任何风速(曲线的形状是相同的,也一定会相同,
因为障碍物只引起风速的相对变化)。曲线相当于风速计算器画出的曲线。Results 结果The result line in the calculator tells you how many per cent the wind speed
will decline due to the presence of the obstacle. You may plot the change in
wind speeds for a number of distances and heights up to 1.5 times your
present distance and height by clicking the Plot Wind Speed button.
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计算器的结果告诉你,由于障碍物的存在风速会降低百分之几。你可以画出在若
干距离和高度上风速的变化。点击 Plot Wind Speed按钮你可以把目前的距离和
高度改变到 1.5倍。(If you are working with a specific Weibull distribution describing the wind in
this particular sector, the change in wind speed corresponds to a change in
the scale factor A. If you use the results of these calculations to find a Weibull
distribution, you can just adjust the scale factor, A, with this change. The
shape factor, k, remains unchanged. You will get to the Weibull distribution
later in this Guided Tour, when we explore how to compute the energy output
from a wind turbine).
如果你用特定的威布尔分布来描述这一特殊扇面的风,风速的变化相当于等级
因子 A的变化。如果你用这些计算结果去获得威布尔分布,你就用这一变化调
节等级因子 A。形状因子 K是不变的。以后,当我们探讨如何计算一台风机的能
量输出时,你会利用这一指导材料得到威布尔分布。The result line also tells you the loss of wind energy due to the presence of
the obstacle. You may plot the change in wind energy for a number of
distances and heights up to 1.5 times your present distance and height by
clicking the Plot Wind Speed button.
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同时,结果会告诉你由于障碍的存在风能会有损失。你可以画出在若干距离和高
度上风能的变化。点击 Plot Wind Speed按钮你可以把目前的距离和高度改变到
1.5倍。More Complex Obstacle Calculations 更复杂的障碍物计算Obstacles may not be perpendicular to the centreline in the sector, and there
may be several rows of obstacles. Although you can still use the basic
methods in the calculator, you would probably want to use a professional wind
assessment programme such as WindPro or WAsP to manage your data in
such cases.
障碍物可以不垂直于扇面的中心线,还可能有几排障碍物。虽然你还能使用计算
器中的基本方法,但在这种复杂的场合,你多半想用专业的风能处理程序去管
理你的数据,诸如使用WindPro 或 WAsP 软件 。The methods used in the wind calculator are based on the European Wind
Atlas. If you read chapter 8, however, you should note that there is a misprint
in formula 8.25.
风能计算器中使用的方法基于欧洲风能图谱。但是如果你读了第八章,你会注意
到在公式 8.25.有一处印刷错误。
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Shade calculator 风影计算器
Wind Shade Calculator 风影计算器Do not operate the form until this page and its programme have loaded
completely. If you are too fast, the programme will complain about missing
data, and you will have to click reload.
直到读完这一页并将程序完全安装以后才能操作这一表格。如果你动作太快,程
序将抱怨你丢失数据,并且你必须重新安装。You should have read about obstacles, roughness and porosity before using
the calculator.
在用计算器之前,你应当读过障碍物、粗糙度和孔隙度各节。CALCULATOR
轮毂高度 m
点击灰色方块以便插入或移除障碍
障碍物与风机间的距离 m
粗糙长度 m
= 粗糙尺度
障碍物高度 m
障碍物宽度 m
= % 扇面宽度的百分比
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未受扰动的能量百分比
70 75 80 85 90 9510
0
选择障碍物的孔隙率:
0%= 30%= 50%= 70%=
孔隙率 %
提交 画出风速画出风能画出速度剖面
m/s轮毂高度的风速
重新举例
结果 t: % 风速减少的百分比
= % 该扇面内风能的损失*
*
To print the results of the plotter programme you should make a screen dump
为了打出绘图程序的结果,你一定将屏幕另存。This calculator shows the shelter effect (wind shade) of blunt obstacles
(buildings, trees) in any 30 degree sector near a wind turbine. You can
change any number, except the results which are labelled with *. If the
obstacle is too tall (more than half the hub height of your turbine) - or too
close (less than five times the height of the obstacle) the programme will warn
you that the results are uncertain, because the detailed geometry of the
obstacle and the angle of the wind will have an important influence on the
resulting effect.
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计算器会显示风机附近任意 30度扇面钝型障碍物(建筑物,树林)的风影(风
屏蔽)效应。你能改变任何数字,除非结果已标*。如果障碍物太高(超过你装风
机轮毂高度的一半)或者障碍物太近(低于障碍物高度的五倍),程序将提示
你结果是不确定的,因为详细的障碍物的几何形状和风的角度将对结果产生重
要的影响。Please note that you only have to consider the percentage of wind energy
coming from this direction cf. the wind rose, because the obstacle obviously
only affects your turbine's energy output when the wind is coming from this
particular direction.
请注意,你只需考虑来至这一方向的风能的百分比(参照风玫瑰图),因为当
风从这一特定方向刮来的时候,障碍物显然只影响风机的能量输出。If you have a fast computer or some patience you may plot the wind speed or
wind energy profile behind the obstacle. (If the plot window disappears, it is
probably hidden behind another window).
如果你有一台速度快的电脑,或者你有耐心就能画出障碍物之后的风速图或者
风能剖面图(如果画图的窗口消失了,它大概藏在另一窗口的后面)。
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Wake 尾流
Wake Effect 尾流效应Since a wind turbine generates electricity from the energy in the wind, the
wind leaving the turbine must have a lower energy content than the wind
arriving in front of the turbine.
因为风机发出的电是从风能而来的。离开风机的风比起从风机前面到达风机的风
具有较低的能量。Wake effect from wind
turbine Picture © Riso
National Laboratory,
Denmark
风机尾流效应的图片,丹麦
Riso国家实验室
This follows directly from the fact that energy can neither be created nor
consumed. If this sounds confusing, take a look at the definition of energy in
the Reference Manual.
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这就直接面对这样一个事实,能量既不能消灭也不能创生。这话听起来就糊涂了
还是看一下参考手册中能量的定义吧。A wind turbine will always cast a wind shade in the downwind direction.
风机总是对其下游造成风影的。In fact, there will be a wake behind the turbine, i.e. a long trail of wind which is
quite turbulent and slowed down, when compared to the wind arriving in front
of the turbine. (The expression wake is obviously derived from the wake
behind a ship).
事实上,在风机之后有一个尾流过程,这就是说与风机前面来流风比较,风有
一个很紊乱的长尾巴,并且速度越来越慢。(尾流这个措辞显然起源于轮船后面
的尾流)。You can actually see the wake trailing behind a wind turbine, if you add
smoke to the air passing through the turbine, as was done in the picture. (This
particular turbine was designed to rotate in a counterclockwise direction which
is somewhat unusual for modern wind turbines).
实际上,如果你在通过风机的空气中加些烟雾,你能看到风机后面蔓延的尾流,
正如在图片中所显示的。(这台特殊的风机设计成逆时针旋转,它与现代风机相
比有点不寻常)。
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Wind turbines in parks are usually spaced at least three rotor diameters from
one another in order to avoid too much turbulence around the turbines
downstream. In the prevailing wind direction turbines are usually spaced even
farther apart, as explained on the next page.
风场中的风机彼此所留的间隔通常为 3倍转轮直径,以便避免风机下游过大的
湍流。在主风向风机通常间隔甚至于更大些,下一节将对此给予解释。
( Wake effect from wind turbine Picture © Riso National Laboratory,
Denmark)
(风机尾流效应图片© 丹麦Riso国家实验室)
The park effect 风场效应
Park Effect 风场效应
As we saw in the previous section on the wake effect , each wind turbine will
slow down the wind behind it as it pulls energy out of the wind and converts it
to electricity.
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正如在前一节尾流效应中所看到的,每台风机之后的风都会慢下来,因为它从
风里抽取了能量转化为电能。Ideally, we would therefore like to space turbines as far apart as possible in
the prevailing wind direction. On the other hand, land use and the cost of
connecting wind turbines to the electrical grid would tell us to space them
closer together.
因此从理想出发,在主风向上风机间距要尽可能远。而另一方面,土地的利用和
风机到电网连线的成本要求我们风机间距尽可能近。Park Layout 风场布置As a rule of thumb, turbines in wind parks are usually spaced somewhere
between 5 and 9 rotor diameters apart in the prevailing wind direction, and
between 3 and 5 diameters apart in the direction perpendicular to the
prevailing winds.
按一般规则,在主风向上风场中风机间距约为 5至 9倍转轮直径;在垂直于主
风向上风机间距约为 3至 5倍转轮直径。In this picture we have placed three rows of five turbines each in a fairly
typical pattern.
在这张图片中,我们安置了三排、每排五台风机,这是非常典型的模式。The turbines (the white dots) are placed 7 diameters apart in the prevailing
wind direction, and 4 diameters apart in the direction perpendicular to the
prevailing winds.
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在主风向上,风机(白点)按 7倍转轮直径布置;而在垂直主风向上,风机按
4倍转轮直径布置.
Energy Loss from the Park Effect 风场效应的能量损失With knowledge of the wind turbine rotor, the wind rose, the Weibull
distribution and the roughness in the different directions manufacturers or
developers can calculate the energy loss due to wind turbines shading one
another.
在不同方向上,按照风机转轮、风玫瑰图、威布尔分布和粗糙度的知识,风机厂
商和发展商能够计算出由于风机依次遮掩产生的能量损失。Typically, the energy loss will be somewhere around 5 per cent.
典型说来,能量损失约为 5%。
The tunnel effect 风洞效应
Speed Up Effects: Tunnel Effect 加速效应:风洞效应
If you push an ordinary bicycle air pump, (just point to the image, do not click)
you will notice that the air leaving the nozzle moves much faster than the
speed with which you are pushing. The reason, of course, is that the nozzle is
much narrower than the cylinder in the pump.
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如果你按下普通的自行车打气筒(就是想象,不要点击),你会注意到空气离
开气门嘴的速度要比你按下打气筒的速度快得多。当然,原因在于气门嘴的通道
要比打气筒的通道窄得多。Tunnel Effect 风洞效应
If you take a walk between tall buildings, or in a narrow mountain pass, you
will notice that the same effect is working:
如果你在高大的建筑物之间或者在窄的山谷间通过,你会注意到有同样的效应
产生。The air becomes compressed on the windy side of the buildings or mountains,
and its speed increases considerably between the obstacles to the wind. This
is known as a "tunnel effect".
在建筑物或者山脉的迎风侧空气被压缩,因此障碍物之间使风速明显增加。这就
是所谓的“风洞效应”。
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So, even if the general wind speed in open terrain may be, say, 6 metres per
second, it can easily reach 9 metres per second in a natural "tunnel".
如果说在开阔的平原可能有每秒 6米的风速,在天然“风洞”中它能很容易达
到每秒 9米。Placing a wind turbine in such a tunnel is one clever way of obtaining higher
wind speeds than in the surrounding areas.
把风机放在这样的风洞里同放在周围区域相比,是获得高风速的聪明途径。To obtain a good tunnel effect the tunnel should be "softly" embedded in the
landscape. In case the hills are very rough and uneven, there may be lots of
turbulence in the area, i.e. the wind will be whirling in a lot of different (and
rapidly changing) directions.
为了得到一个好的风洞,这个风洞在地貌上应该有一个“柔和”的内涵。一旦山
丘很粗糙和不平整,就会在该地域形成大量的湍流,也就是说,风会在许多不
同的(及迅速变化的)方向上旋转。If there is much turbulence it may negate the wind speed advantage
completely, and the changing winds may inflict a lot of useless tear and wear
on the wind turbine.
如果有许多湍流,它可能完全抵消了风速高的优点,而不断变化的风可能对风
机造成许多无益的剪切和磨损。
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The hill effect 山丘效应
Speed Up Effects: Hill Effect 加速效应:山丘效应
[The wind in passing the summits of mountains becomes swift and dense and
as it blows beyond the mountains it becomes thin and slow, like water that
issues from a narrow channel into the wide sea. Notebooks of Leonardo da
Vinci (1452-1519)]
[当风通过山地顶点的时候,速度很快,密度很高;而当风越过山顶的时候,速
度和密度都会降低,就像水由一个窄的通道流向大海一样。Leonardo da Vinci
(达芬奇笔记)(1452-1519)]
A common way of siting wind turbines is to place them on hills or ridges
overlooking the surrounding landscape. In particular, it is always an
advantage to have as wide a view as possible in the prevailing wind direction
in the area.
风机选址的一个通常方式是把风机放在山岗或山脊上,站在那里可以俯览周围
的地貌。尤其是,在主风向区域尽可能有开阔的视野,这总是最佳选择。On hills, one may also experience that wind speeds are higher than in the
surrounding area. Once again, this is due to the fact that the wind becomes
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compressed on the windy side of the hill, and once the air reaches the ridge it
can expand again as its soars down into the low pressure area on the lee side
of the hill.
在山上,人们总可以体会到风速要比周围环境的高。再说一遍,这是由于风在山
的迎风侧被压缩,一旦风达到了山脊它就会再一次膨胀,咆哮而下进入山的背
风侧的低压区域。
You may notice that the wind in the picture starts bending some time before it
reaches the hill, because the high pressure area actually extends quite some
distance out in front of the hill.
你可能注意到,图片中的风在到达山岗之前开始弯曲,因为在山岗之前高压区
域实际上扩展相当一段距离。Also, you may notice that the wind becomes very irregular, once it passes
through the wind turbine rotor.
同时你还注意到,一旦风通过了风机转轮,它就变得很无规则。As before, if the hill is steep or has an uneven surface, one may get significant
amounts of turbulence, which may negate the advantage of higher wind
speeds.
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如前所述,如果山陡峭或者有不平整的表面,就会产生大量的湍流,它会抵消
了高风速的优点。
Turbine siting 风机选址
Selecting a Wind Turbine Site 选择一处风机场址
Photograph Soren Krohn© 1997 DWIA(Soren Krohn拍摄© 1997 DWIA)
Wind Conditions 风况Looking at nature itself is usually an excellent guide to finding a suitable wind
turbine site.
现场考察通常是找到合适风机场址的最佳途径。If there are trees and shrubs in the area, you may get a good clue about the
prevailing wind direction, as you do in the picture to the left.
如果现场有树林或者灌木丛,你就可能获得主风向的最佳线索,如图片中左侧
所示。If you move along a rugged coastline, you may also notice that centuries of
erosion have worked in one particular direction.
如果沿着崎岖的海岸线走去,你也会注意到在一个特定的方向上有百年的风蚀。
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Meteorology data, ideally in terms of a wind rose calculated over 30 years is
probably your best guide, but these data are rarely collected directly at your
site, and here are many reasons to be careful about the use of meteorology
data, as we explain in the next section.
借助于超过 30年计算而得的风玫瑰图的气象数据或许是你最好的指导,但是这
些数据很少是在你的场址直接收集到的。有很多原因要求你谨慎使用气象数据,
这一点我们将在下一部分解释。If there are already wind turbines in the area, their production results are an
excellent guide to local wind conditions. In countries like Denmark and
Germany where you often find a large number of turbines scattered around
the countryside, manufacturers can offer guaranteed production results on the
basis of wind calculations made on the site.
如果在现场已经有了风机,它们的生产结果是局部风况的最佳指南。在丹麦和德
国这样的国家,你常常看到大量的风机散布在乡村,制造商基于在现场做的风
能计算往往能保证发电量。Look for a view 观察中寻找As you have learned from the previous pages, we would like to have as wide
and open a view as possible in the prevailing wind direction, and we would
like to have as few obstacles and as low a roughness as possible in that same
direction. If you can find a rounded hill to place the turbines, you may even get
a speed up effect in the bargain.
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正如你们在前几节所学的,在主风向上我们喜欢尽可能有宽广和开阔的视野,
同时在那同一方向上我们喜欢有尽可能少的障碍物和尽可能低的粗糙度。如果你
能找到一个圆形的山岗安装风机,你可能得到一个加速效应的便宜货。Grid Connection 联网Obviously, large wind turbines have to be connected to the electrical grid.
显然,大型风机必须连到电网上。For smaller projects, it is therefore essential to be reasonably close to a 10-30
kilovolt power line if the costs of extending the electrical grid are not to be
prohibitively high. (It matters a lot who has to pay for the power line extension,
of course).
因此对于小项目,如果延伸电网的成本不是高得难以接受,用 10-30KV输电线
基本上就是合理的(当然,谁花电网延伸的钱很有关系)。The generators in large, modern wind turbines generally produce electricity at
690 volts. A transformer located next to the turbine, or inside the turbine
tower, converts the electricity to high voltage (usually 10-30 kilovolts).
发电机很大,现代风机一般以 690V的电压发电。变压器挨着风机布置,或者放
在风机塔架内,它能将发出的电力转换成高压(通常 10-30KV)。Grid Reinforcement 电网的加强The electrical grid near the wind turbine(s) should be able to receive the
electricity coming from the turbine. If there are already many turbines
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connected to the grid, the grid may need reinforcement, i.e. a larger cable,
perhaps connected closer to a higher voltage transformer station. Read the
section on Electrical Grid Issues for further information.
风机附近的电网应当能接受来自风机的电力。如果已经有许多风机连到电网上,
电网可能需要加强,这就是说要用粗的缆线,或者连线要接近高压变电站。要了
解详情,请阅读电网专题部分。Soil Conditions 土质状况Both the feasibility of building foundations of the turbines, and road
construction to reach the site with heavy trucks must be taken into account
with any wind turbine project.
任何风机项目,无论是风机建筑基础可行性,还是有重型卡车通过的路面结构
都必须考虑土质状况。Pitfalls in Using Meteorology Data 使用气象数据的缺陷Meteorologists already collect wind data for weather forecasts and aviation,
and that information is often used to assess the general wind conditions for
wind energy in an area.
气象学家已经收集了天气预报和航空所用的风能数据,这些信息常常用于评价
一个地区风能的一般风况。Precision measurement of wind speeds, and thus wind energy is not nearly as
important for weather forecasting as it is for wind energy planning, however.
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天气预报要精确测量风速,因此风能对天气预报来说就不像对风能规划那么重
要。Wind speeds are heavily influenced by the surface roughness of the
surrounding area, of nearby obstacles (such as trees, lighthouses or other
buildings), and by the contours of the local terrain.
风速受到环境地区表面粗糙度的严重影响,比如临近障碍物(树木、灯塔或其他
建筑物),还可能受到局部地形起伏的影响。Unless you make calculations which compensate for the local conditions
under which the meteorology measurements were made, it is difficult to
estimate wind conditions at a nearby site. In most cases using meteorology
data directly will underestimate the true wind energy potential in an area.
除非你做了计算,对气象测量的局部风况做了补偿,否则是很难估计场址附近
的风况的。在多数情况下,直接使用气象数据会低估了该地区真实的风能潜力。We'll return to how the professionals do their wind speed calculations on the
following pages.
下一节我们将讨论专业人员如何做风速计算。
Offshore winds 海上风能
Offshore Wind Conditions 海上风况
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(500 kW offshore wind turbine at Tunø Knob, Denmark.
Photograph © 1996 Vestas Wind Systems A/S)
(在 Tunø Knob 的 500 kW 海上风机 , 丹麦照片© 1996
Vestas风能系统 A/S)
Wind Conditions at Sea 海上风况The surfaces of seas and lakes are obviously very smooth, thus the
roughness of a seascape is very low (at constant wind speeds). With
increasing wind speeds some of the energy in the wind is used to build
waves, i.e. the roughness increases. Once the waves have been built up, the
roughness decreases again. We thus have a surface with varying roughness,
(just as you have it in areas covered with more or less snow).
显然海面和湖面非常光滑,因此海貌的粗糙度是很低的(风速恒定)。随着风速
的增加,某些风能由于形成波浪,于是粗糙度增加了。一旦波浪已经形成,粗糙
度又降低了。于是就有一个粗糙度不断变化的表面(就像某些地区覆盖着或薄或
厚的雪一样)。Generally speaking, however, the roughness of the water surface is very low,
and obstacles to the wind are few. When doing wind calculations we have to
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account for islands, lighthouses etc. just like you would account for upwind
obstacles or changes in roughness on land.
但是,一般说来水面的粗糙度很低,对风的障碍物几乎没有。当进行风况计算时
我们必须考虑到岛屿、灯塔等,就像你考虑逆风障碍物或者考虑陆地上粗糙度的
变化一样。Low Wind Shear Means Lower Hub Height 低的风剪切意味着低的轮毂高度With low roughness, wind shear at sea is very low, i.e. the wind speed does
not change very much with changes in the hub height of wind turbines. It may
therefore be most economic to use fairly low towers of perhaps 0.75 times the
rotor diameter for wind turbines located at sea, depending upon local
conditions. (Typically towers on land sites are about the size of the rotor
diameter, or taller).
由于低的粗糙度,海上的风剪切是很低的,也就是说,当风机轮毂高度变化时
风速没有很大变化。因此,可以使用相当低的塔架获得最好的经济效果,风机处
在海面上,或许 0.75倍转轮直径作为塔架高度即可,具体由当地条件决定。
(陆地场址典型塔架的高度约为转轮直径的尺寸或者更高)。Low Turbulence Intensity = Longer Lifetime for Turbines 低湍流强度=较长的风机寿命The wind at sea is generally less turbulent than on land. Wind turbines located
at sea may therefore be expected to have a longer lifetime than land based
turbines.
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一般说来,海上风能的湍流强度比陆地上的要低。因此,海上的风机预计比陆地
上的风机具有较长的寿命。The low turbulence at sea is primarily due to the fact that temperature
variations between different altitudes in the atmosphere above the sea are
smaller than above land. Sunlight will penetrate several metres below the sea
surface, whereas on land the radiation from the sun only heats the uppermost
layer of the soil, which thus becomes much warmer.
海洋上的低湍流主要是由于海洋上空大气内不同高度之间温度的变化比陆地上
空要小。阳光在海面下会穿透几米,而在陆地上太阳的辐射只能加热土壤的最上
层,因此这层土壤就更热。Consequently the temperature difference between the surface and the air will
be smaller above sea than above land. This is the reason for lower
turbulence.
因此,海上表面与空气的温差比陆地表面与空气的温差要小。这就是海风具有较
低湍流度的原因。
Wind Shade Conditions at Sea 海上的风影状况The conventional WAsP model used for onshore wind modelling is in the
process of being modified for offshore wind conditions, according to its
developer, Risø National Laboratory.
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用于陆上风能模拟的常规WAsP模型在经过它的发展商 Risø国家实验室修改
后可用于海上风况。The different production results obtained from the experience of the first major
offshore wind park at Vindeby, Denmark, and the subsequently built wind park
at Tunø Knob, Denmark, has led to new investigations with anemometer
masts being placed offshore in a number of locations in Danish waters since
1996.
从丹麦第一个海上风场和随后的海上风场的经验,即 Vindeby 和 Tunø Knob 风
场获得了不同的发电结果,这促使我们用测风塔进行新的调查。从 1996年在丹
麦水域的海面上许多位置安装了测风塔。The preliminary results indicate that wind shade effects from land may be
more important, even at distances up to 20 kilometres, than was previously
thought.
初步结果指出陆地上风影效应更显著,甚至于影响到 20km的距离,这比以前
想的要严重。On the other hand, it appear that the offshore wind resource may be some 5
to 10 per cent higher than was previously estimated.
另一方面,业已揭示海上风资源可能比先前估计的约高 5-10%
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Wind map Europe 欧洲风图
Wind Map of Western Europe 西欧风图
Wind Resources at 50 (45) m Above Ground Level地面上方 50(45)m处的风资源
How to Read the Wind Map of Western Europe 如何阅读西欧风图
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在海岸边开阔的海面 山岗和山脊颜色 遮掩的地形开阔平原
This wind map of Western Europe was originally published as part of the
European Wind Atlas. The details on how to interpret the colours are given in
the legend above. Please note that the data for Norway, Sweden and Finland
are from a later study, and are calculated for 45 m height above ground level,
and assume an open plain.
原先出版的西欧风图作为欧洲风能图谱的一部分。在图例中给出了如何解释各种
颜色的详情。请注意,挪威、瑞典和芬兰的数据取自于后来的研究,由地面上方
45米的高度计算而得,并假定为开阔地。The purple zones are the areas with the strongest winds while the blue zones
have the weakest winds. The dividing lines between the different zones are
not as sharp as they appear on the map. In reality, the areas tend to blend
smoothly into one another.
紫色的区域代表强风区域,而蓝色的区域代表弱风区域。不同区域间的分割线不
像它们在图中表现得那么明显。实际上,各区域平稳的交融进入另一区域。You should note, however, that the colours on the map assume that the globe
is round without obstacles to the wind, speed up effects , or varying
roughness of the terrain. You may therefore easily find good, windy sites for
wind turbines on hills and ridges in, say the yellow or green areas of the map,
while you have little wind in sheltered terrain in the purple areas.
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但是你应当注意,地图上的颜色设想地球是圆的,对风没有障碍,没有加速效
应或改变粗糙度的地形。因此,你可以很容易找到山岗或山脊上的良好的风机场
址,即使它们在黄色或绿色区域;而在紫色区域遮掩的地形中也有没风的地方。The Power of the Wind 风的功率In case you cannot explain why the calculated mean power of the wind in the
table is approximately twice the power of the wind at the given mean wind
speed, you should read the four to six pages starting with the Weibull
Distribution.
一旦你不能解释,为什么表中计算的风的平均功率近似为给定平均风速的风功
率的两倍,你应当从威布尔分布开始阅读 4到 6页。Reality is More Complicated 实际情况更为复杂Actual local differences in the terrain will mean that the picture will be much
more complicated, if we take a closer look. As an example, we will now take a
closeup view of Denmark on the next page.
如果我们仔细看一下,地形的实际局部差别意味着图片将变得更为复杂。例如,
在下页我们将仔细地看丹麦。
Wind map Denmark 丹麦的风图
Wind Map of Denmark 丹麦的风图
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How to Read the Wind Map of Denmark 如何阅读丹麦的风图This unique map of Danish wind speeds takes local terrain ( speed up effects)
and roughness into account. It shows a much more detailed
picture of wind conditions than we saw on the previous page.
We can clearly see that West and Southwest are the prevailing
wind direction in Denmark, since West and Southwest facing
coastal sites have by far the highest energy content of the wind (the red and
yellow areas).
独特的丹麦风速图对局部地形(加速效应)和粗糙度给予了考虑。与我们在前页
看到的相比,它展示了更为详细的风况画卷。我们能清楚地看到西部和西南部是
丹麦的主风向,因为西部和西南部面临海滨,场址具有高得多的风能(红色和
黄色区域)。
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The map is actually a very high resolution map, where the area of the whole
country (44,000 km 2 area) was divided into 1.1 million squares 200 by 200 m
each (220 by 220 yards), and the mean wind speed was calculated for each
square. You may download the map in various resolutions from the web site
of Energy & Environmental Data in Denmark, if you wish (it is also available
on CD-ROM).
实际上,该图有很高的分辨率,整个国家的地域(面积 44000km2)分成
200×200m的 110万个方格,计算出每个方格的平均风速。如果你愿意,可从
丹麦的能源和环境数据(Energy & Environmental Data)网站下载各种分辨率
的风资源图(同时可提供 CD-ROM)。Using the Wind Map for Planning 用风资源图做规划This wind map was developed to assist the Danish municipalities in their
planning (zoning) work for wind turbines. Each municipality in Denmark is
responsible for allocating suitable areas for wind turbines in order that the
Government may fulfill its plans to supply 50% of the country's electricity
consumption by wind energy in 2030.
开发风资源图以便帮助丹麦政府当局制定风机发展规划。丹麦的每级政府都有责
任为风机规划适当的区域,以便政府可以实现他的计划,即到 2030年国家电
力消耗的 50%将由风电提供。Using the Wind Map for Wind Prospecting 用风资源图实现风能预期The map is obviously also a gift to wind project developers, who can see the
(probable) best wind fields in the country directly. One could therefore hardly
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imagine it being financed and published by any other institution than a
government.
显然,风资源图对于风能项目发展商是一份很好的礼物,发展商能直接(很可
能)看到国家的最好风场。因此,人们几乎不能想象除了政府以外,它会得到任
何其他机构的财政支持和出版。The map, however, is not sufficient for actually locating a wind turbine, since it
was generated mechanically, without detailed verification in the terrain. In
order to make proper calculation of annual electricity output one would have
to go to the prospective site and verify e.g. the roughness and locate
obstacles and check for new buildings, trees etc.
但是,实际上风资源图不足以为风机定位,因为它是被机械生成的,没有在地
形上实证。为了正确计算年发电量,人们必须到预期的场地核实,诸如粗糙度、
障碍物的位置,并检查新型建筑物,树木等。State of the Art Methods of Wind Assessment 最新的风能评估方法This map was produced for the Danish Energy Agency by Energy &
Environmental Data, a wind energy software and consultancy firm in
collaboration with the Wind Energy Department of Risoe National Laboratory,
which developed the basic fluid dynamics software used for the wind
calculations, the WAsP programme.
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这张图是为丹麦能源总署(Danish Energy Agency)制作的,由能源环境数据
网站、风能软件顾问公司与Risoe 国家实验室 风能部共同合作完成的。他们开发
了基本的流体力学软件用于风能计算,即WAsP程序。Calculating such a detailed wind map of a large area is actually an enormous
task: The map was made on the basis of extremely detailed digital maps at
the scale of 1:25000. The maps in reality consist of 7 layers, with one layer
representing altitude contours (orography), another forests and fences (and
even individual large trees), a third layer buildings, a fourth layer lakes and
rivers etc. The programme that generates roughness data for the WAsP
programme determines terrain contours and contiguous areas of forests,
lakes, cities etc. in neighbouring squares of each square out to a distance of
20,000 m in all wind directions.
计算这样一个大面积的详细的风能资源图实际上是一个庞大的任务。该图的制作
基于一份极其详细的比例为 1:25000.的数字地图。该图实际上由 7个层次组成,
一层代表地貌的海拔高度(山志学),另一层代表森林和围栏(以及独立的大
树),第三层代表建筑物,第四层代表湖泊和河流等。为WAsP 软件产生粗糙
度数据的程序确定了地形的外貌以及邻近区域的森林、湖泊、城市等。每一方格
的临近方格在所有方向上都超出 20000m的距离。The results were subsequently recalibrated using statistics from several
hundred wind turbines scattered throughout the country for which energy
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output data are available. Thus it has been possible to compensate for the
fact that the mean wind speeds in Denmark tend to decrease, as we move
towards the East.
随后这一结果利用散布在全国几百台风机的统计数据进行校准,这些风机的能
量输出数据是可以利用的。因此,对下述情况进行补偿是可能的:因为我们朝东
移动,丹麦的平均风速趋于下降。
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Energy output 能量输出
The Weibull distribution 威布尔分布
Describing Wind Variations: Weibull Distribution
描述风速的变化:威布尔分布The General Pattern of Wind Speed Variations 风速变化的一般形式It is very important for the wind industry to be able to describe the variation of
wind speeds. Turbine designers need the information to optimise the design
of their turbines, so as to minimise generating costs. Turbine investors need
the information to estimate their income from electricity generation.
能够描述风速的变化对风能产业是非常重要的。风机设计师需要这一信息以便对
风机设计最佳化,从而降低成本。风机投资商需要这一信息以便估计他们发电的
收入。
If you measure wind speeds throughout a year, you will notice that in most
areas strong gale force winds are rare, while moderate and fresh winds are
quite common.
如果你测量全年的风速,就会注意到大多数地区非常强的大风是很少的,而中
等的、温和的风速却很常见。The wind variation for a typical site is usually described using the so-called
Weibull distribution, as shown in the image. This particular site has a mean
wind speed of 7 metres per second, and the shape of the curve is determined
by a so called shape parameter of 2.
典型场址风的变化通常用所谓的威布尔分布来描述,如上图所示。这一特定场址
具有 7m/s的平均风速,而它的形状由所谓的形状参数 2来确定。Statistical Description of Wind Speeds 风速的统计描述People who are familiar with statistics will realise that the graph shows a
probability density distribution. The area under the curve is always exactly 1,
since the probability that the wind will be blowing at some wind speed
including zero must be 100 per cent.
熟悉统计学的人们会明白,上面的图表示一个概率的分布。曲线下的面积总是精
确为 1,因为在所有风速下,包括零风速,刮风的概率加起来必定是 100%。Half of the blue area is to the left of the vertical black line at 6.6 metres per
second. The 6.6 m/s is called the median of the distribution. This means that
half the time it will be blowing less than 6.6 metres per second, the other half
it will be blowing faster than 6.6 metres per second.
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蓝色面积的一半就是垂直黑线的左侧,黑线所处的风速是 6.6m/s。6.6m/s称为
中值分布。这意味着有一半的时间风速低于 6.6m/s,另一半的时间风速高于
6.6m/s。You may wonder then, why we say that the mean wind speed is 7 metres per
second. The mean wind speed is actually the average of the wind speed
observations we will get at this site.
那么你会惊讶,为什么我们说平均风速是 7m/s。实际上,平均风速是我们在现
场观察的风速的平均值。As you can see, the distribution of wind speeds is skewed, i.e. it is not
symmetrical. Sometimes you will have very high wind speeds, but they are
very rare. Wind speeds of 5.5 metres per second, on the other hand, are the
most common ones. 5.5 metres is called the modal value of the distribution. If
we multiply each tiny wind speed interval by the probability of getting that
particular wind speed, and add it all up, we get the mean wind speed.
如你所见,风速的分布是偏的,也就是说并不是对称的。有时你遇到很高的风速
但是它们很少出现。另一方面,5.5m/s的风速是最常见的,这个风速称为分布
的形态值。我们将每一微小的风速间隔乘以得到这一风速的概率,然后求其和,
我们就得到了平均风速。
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The statistical distribution of wind speeds varies from place to place around
the globe, depending upon local climate conditions, the landscape, and its
surface. The Weibull distribution may thus vary, both in its shape, and in its
mean value.
风速的这种统计分布在全球随地点而变化,这取决于局部的气候条件,地形和
地貌。因此,威布尔分布是变化的,无论它的形状还是它的平均值都是变化的。If the shape parameter is exactly 2, as in the graph on this page, the
distribution is known as a Rayleigh distribution. Wind turbine manufacturers
often give standard performance figures for their machines using the Rayleigh
distribution.
如果形状参数是 2,如本页图中所示,这种分布称为瑞利分布。风机制造商经常
使用瑞利分布对它们的风机给出标准的性能图。Balancing the Weibull Distribution 威布尔分布的配平Another way of finding the mean wind speed is to
balance the pile of blue bricks to the right, which shows
exactly the same as the graph above. Each brick
represents the probability that the wind will be blowing at
that speed during 1 per cent of the time during the year. 1 m/s wind speeds
are in the pile to the far left, 17 m/s is to the far right.
找到平均风速的另一办法是把右侧的蓝色砖堆配平,它与上面的图精确地一致。
每一块砖都代表在那个风速下刮风的概率,即代表一年时间的 1%。1 m/s的风
速在砖堆的最左边,17 m/s的风速在砖堆的最右边。111
The point at which the whole pile will balance exactly will be at the 7th pile, i.e.
the mean wind speed is 7 m/s.
整个砖堆精确在第 7堆找到平衡点,即平均风速是 7 m/s。Try This! 试一次If you have a Netscape 3, 4 or Internet Explorer 4 browser, the next page will
let you experiment with different values for the Weibull parameters to get a
grasp of what the wind speed probability distribution looks like.
如果你有 Netscape 3, 4 或 Internet Explorer 4 浏览器,下页将让你试验一下,
用不同的威布尔参数值去领会风速概率分布是什么样子。
Distribution plotting 分布绘图
Weibull Distribution Plotter Programme 威布尔分布绘图程序
Choose between entering
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在其间取值输入
mean wind speed (2.0-12.0 m/s) or
平均风速(2.0-12.0 m/s)或
scale parameter A in the first box
这个盒子里的尺度参数 A
, then enter shape k = (1.0-3.0).
然后输入形状参数 k
Click Weibull to draw.
点击 开始画图This page will give you an idea of the way different Weibull distributions look.
The mean wind speed or the scale parameter, A, is used to indicate how
windy the site is, on average. The shape parameter, k, tells how peaked the
distibution is, i.e. if the wind speeds always tend to be very close to a certain
value, the distibution will have a high k value, and be very peaked.
本节给你一个概念,知道不同威布尔分布是啥样子。平均风速或者尺度参数 A
用于指出平均说来场地的风有多大。形状参数 k 告诉你这个分布曲线有多尖,这
就是说,如果风速总是趋向接近于某一值,则该分布就有一个高的 k 值,也就
是曲线很尖。
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Start by clicking Weibull to see the result of our example on the previous
page. Then try changing one parameter at a time, and watch what happens.
点击Weibull就会看到前页中举例的结果。然后每次试着改变一个参数看看发生
了什么。To print the results of the plotter programme you should make a screen dump.
为了打印绘图程序的结果,你应当做屏幕保存。
The average bottle fallacy 平均的瓶形谬误
The Average Bottle Fallacy 平均的瓶形谬误What is the average energy content of the wind at your wind turbine site?
什么是风机所在场址的平均风能?Most people who are new to wind energy think they could easily live
without the Weibull distribution. After all, if we know the average wind
speed, we also know the average power of the wind, don't we? So, can't
we just use the power (or energy) at the mean wind speed to figure out
how much power (or energy) will hit the wind turbine?
多数人对风能感到很新鲜,他们认为没有威布尔分布也能容易生活。是否我们最
终要知道平均风速,也要知道平均风功率,不是吗?所以,我们不能用平均风
速的功率(或能量)计算出有多少功率(或能量)提供给风机吧?
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In other words, couldn't we just say, that with an average wind speed of 7 m/s
we get an average power input of 210 Watts per square metre of rotor area?
(You may find that figure in the table on the power of the wind in the
Reference Manual).
换句话说,我们不能说按平均风速 7 m/s我们就能得到每平方米转轮面积
210W的平均功率输入吧?(在参考手册的风功率表中你可以找到具体数值)。The answer is no! We would underestimate wind resources by almost 100 per
cent. If we did that, we would be victims of what we could call the Average
Bottle Fallacy: Look at the smallest and largest bottle in the picture. Both have
exactly the same shape. One is 0.24 m tall, the other is 0.76 m tall. How tall is
the average bottle?
答案是否定的!我们几乎 100%的低估了风资源。如果我们那样做,我们就成了
所说的平均瓶形谬误的牺牲品。请看图中最小的和最大的瓶子,两个形状精确一
样。一个是 0.24 m高,另一个是 0.76 m高。瓶子容量平均是多高?If you answer 0.5 m tall, you are a victim of the Average Bottle Fallacy. Bottles
are interesting because of their volume, of course. But the volume varies with
the cube (the third power) of their size. So, even though the largest bottle is
only 3.17 times larger than the small bottle, its volume is actually 3.17 3 =32
times larger than the small bottle.
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如果你回答是 0.5m高,你就成了平均瓶形谬误的牺牲品。当然,瓶子因为它的
容积很有趣。但是,容积随尺寸的立方(三次方)而变化。所以,尽管大瓶子高
只是小瓶子的 3.17倍,它的容积实际上是小瓶子的 3.17 3 =32倍。The average volume is therefore 16.5 times that of the small bottle. This
means that a bottle with an average volume would have to be 2.55 times the
height of the small bottle, i.e. 0.61 m tall.
因此,平均容积是小瓶子的 16.5倍。这就意味着,具有平均容积的瓶子其高度
必须是小瓶子的 2.55倍(因为 2.55 3 = 16.5),也就是 0.61 m 高。The point we are trying to make, is that you cannot simply take an average of
wind speeds, and then use the average wind speed for your power
calculations. You have to weigh each wind speed probability with the
corresponding amount of power. On the next two pages we shall calculate the
energy in the wind. First we use the bottle example to grasp the idea, then we
use simple math.
我们力图强调的一点是,你不能简单地取风速的平均值,然后用平均风速做功
率计算。你必须权衡对应相应功率的每一风速的概率。下两节我们将计算风能。
首先我们用瓶子的例子掌握这一概念,然后我们运用简单的数学方法。
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Mean power of the wind 平均风功率
Mean (Average) Power of the Wind 平均风功率Balancing the Power Distribution 平衡功率的分配The reason why we care about wind speeds is their energy content, just like
with the bottles on the previous page: We cared about their content in terms
of volume. Now, the volume of a bottle varies with the cube of the size, just
like wind power varies with the cube of the wind speed. Let us take the
Weibull distribution of wind speeds, and for each speed we place a bottle on a
shelf each time we have a 1 per cent probability of getting that wind speed.
The size of each bottle corresponds to the wind speed, so the weight of each
bottle corresponds to the amount of energy in the wind.
我们注意风速的原因是因为它们含有能量,就像前页介绍的瓶子有容积一样。借
助于容积我们注意到了风的容量。既然瓶子的容积随尺寸的立方而变化,就像风
功率随风速的立方而变化一样。我们取风速的威布尔分布,对每一风速每次我们
在架子上放一个瓶子,这代表那个风速 1%的概率。瓶子的尺寸相应于风速,所
以每个瓶子的重量就相应于风能的量。
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To the right, at 17 m/s we have some really heavy bottles, which weigh almost
5000 times as much as the bottles at 1 m/s. (At 1 m/s the wind has a power of
0.61 W/m 2 . At 17 m/s its power is 3009 W/m 2).
在右侧 17 m/s处我们有确实很重的瓶子,其重量几乎为 1 m/s 瓶子重量的
5000倍。(1 m/s风速的功率密度为 0.61 W/m 2,17m/s风速的功率密度为3009
W/m 2。)Finding the wind speed at which we get the mean of the power distribution is
equivalent to balancing the bookshelves. (Remember how we did the
balancing act on the Weibull distribution page?). In this case, as you can see,
although high winds are rare, they weigh in with a lot of energy.
找到平均功率分布的风速相当于使书架获得了平衡。(记得在威布尔分布一节我
们是如何配平的?)。在这一案例你可以看到,尽管高风速是稀少的,它们能量
的权重很大。So, in this case with an average wind speed of 7 m/s, the power weighted
average of wind speeds is 8.7 m/s. At that wind speed the power of the wind
is 402 W/m 2 , which is almost twice as much as we figured out in our naive
calculation on the top of the previous page.
所以,在这一案例中平均风速是 7 m/s,功率权重的平均风速是 8.7 m/s。在那
个风速下风功率是 402 W/m 2,几乎是前一节我们天真计算的 2倍。
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On the next pages we will use a more convenient method of finding the power
in the wind than hauling bottles around...
在下一节我们将使用比摆瓶子更为便利的方法求出风功率。
Betz' law 贝兹定律
Betz' Law 贝兹定律The Ideal Braking of the Wind 风的理想制动方式The more kinetic energy a wind turbine pulls out of the wind, the more the
wind will be slowed down as it leaves the left
side of the turbine in the picture. (If you wonder
about the stream tube in the picture, you have
not read the page on how the wind turbine
deflects the wind).
在图中,风机从风中取出的动能越多,风离开风机左侧时风速下降越多。(如果
你对图中的流管不理解,说明你还没读过风机如何使风偏转这一节)。If we tried to extract all the energy from the wind, the air would move away
with the speed zero, i.e. the air could not leave the turbine. In that case we
would not extract any energy at all, since all of the air would obviously also be
prevented from entering the rotor of the turbine.
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如果我们想从风里抽取全部能量,空气就会以零速度流出,也就是说,空气不
能离开风机。在那种情况下,我们根本不能从风中提取任何能量,因为进入风机
转轮的空气明显被阻止了。In the other extreme case, the wind could pass though our tube above without
being hindered at all. In this case we would likewise not have extracted any
energy from the wind.
另一个极端情况,风能够不受任何阻碍通过上述流管。在这种情况下,我们也不
能从风中提取任何能量。We can therefore assume that there must be some way of braking the wind
which is in between these two extremes, and is more efficient in converting
the energy in the wind to useful mechanical energy. It turns out that there is a
surprisingly simple answer to this: An ideal wind turbine would slow down the
wind by 2/3 of its original speed. To understand why, we have to use the
fundamental physical law for the aerodynamics of wind turbines:
因此,我们设想一定有一种阻碍风的方式介于上述两个极端情况之间,并能更
有效地转换风能为有用的机械能。业已指出,对于这一点有一个令人惊奇的简单
的回答:一台理想的风机会将原有的风速降低 2/3。要理解为什么,我们必须使
用风机空气动力学的基本物理定律。Betz' Law 贝兹定律
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Betz' law says that you can only convert less than 16/27 (or 59%) of the
kinetic energy in the wind to mechanical
energy using a wind turbine.
贝兹定律指出:你只能利用风机将低于 16/27
(即 59%)的风的动能转换为机械能。Betz' law was first formulated by the German
Physicist Albert Betz in 1919. His book
"Wind-Energie" published in 1926 gives a
good account of the knowledge of wind
energy and wind turbines at that moment.
1919年贝兹定律为德国物理学家阿尔伯特·贝兹(Albert Betz)首次阐明。他
1926年出版的“风能”一书,对风能和风机的理解提出了当时最好的见解。It is quite surprising that one can make such a sweeping, general statement
which applies to any wind turbine with a disc-like rotor.
令人惊讶的是,人们能够使这样笼统的、常规的陈述应用于任何圆盘转轮的风机To prove the theorem requires a bit of math and physics, but don't be put off
by that, as Betz himself writes in his book. Betz' own proof of the theorem is
included in the Reference Manual on this web site.
正如贝兹在他的书中写的,为了证明这一定理需要一点数学和物理知识,但是
不要为这件事分心。贝兹自己的定理证明收录在本网站的参考手册中。
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Power density 功率密度
Power Density Function 功率密度函数Power of the Wind 风功率From the page on the energy in the wind, we know that the energy potential
per second (the power) varies in proportion to the cube (the third power) of
the wind speed, and in proportion to the density of the air. (Its weight per unit
of volume).
由风能那一节可知,每秒的能量潜力(功率)随风速的立方(三次方)成比例
变化,并随空气的密度(单位容积的质量)成比例变化。
总的功率输入 可用的功率输入(贝兹定律) 风机的功率输出We may now combine everything we have learned so far: If we multiply the
power of each wind speed with the probability of each wind speed from the
Weibull graph, we have calculated the distribution of wind energy at different
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wind speeds = the power density.Notice, that the previous Weibull curve
changes shape, because the high wind speeds have most of the power of the
wind.
现在我们可以把至今学到的每一件事结合起来,如果我们把每一风速下的功率
乘以威布尔图中每一风速下的概率,我们就计算出不同风速下的风能分布,就
等于算出了功率密度。注意,先前的威布尔曲线形状改变了,因为高风速下风功
率更高。From Power Density to Power Output 从功率密度到功率输出This graph was drawn using the wind turbine power calculator on this web
site. The area under the grey curve (all the way to the axis at the bottom)
gives us the amount of wind power per square metre wind flow we may
expect at this particular site. In this case we have a mean wind speed of 7 m/s
and a Weibull k=2, so we get 402 W/m 2. You should note that this is almost
twice as much power as the wind has when it is blowing constantly at the
average wind speed.
利用这一网址上的风机功率计算器画出这张图。灰色曲线下的面积(至底部轴线
的所有面积)给出了每平方米风功率的量,这是在这一特殊场址我们所期望的。
在这一例子中,平均风速是 7 m/s,形状参数 k=2,所以我们得到 402 W/m 2。
你应当注意,这几乎是恒定平均风速时所得功率的 2倍。The graph consists of a number of narrow vertical columns, one for each 0.1
m/s wind speed interval. The height of each column is the power (number of
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watts per square metre), which that particular wind speed contributes to the
total amount of power available per square metre.
该图由许多窄的竖条组成,每条的风速间隔为 0.1 m/s。每条的高度就是功率密
度(每平方米的瓦数),也就是那个特定风速贡献于每平方米的功率总量。The area under the blue curve tells us how much of the wind power we can
theoretically convert to mechanical power. (According to Betz' law, this is
16/27 of the total power in the wind).
蓝色曲线下的面积告诉我们理论上有多少风功率能够转换成机械功率。(根据贝
兹定律,其值为总风功率的 16/27)。The total area under the red curve tells us how much electrical power a
certain wind turbine will produce at this site. We will learn how to figure that
out in a moment when we get to the page on power curves.
红色曲线下的总面积告诉我们,在这一场址风机将发出多少电功率。当我们进入
功率曲线这一节时,我们会学到如何很快计算出这一数值。The Important Messages in the Graph 图中的重要信息The most important thing to notice is that the bulk of wind energy will be found
at wind speeds above the mean (average) wind speed at the site.
值得注意的重要一点是,风能的大部分将在高于场址平均风速段获得。This is not as surprising as it sounds, because we know that high wind speeds
have much higher energy content than low wind speeds.
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这并不奇怪,因为我们知道高风速比低风速具有高得多的能量。The Cut In Wind Speed 切入风速Usually, wind turbines are designed to start running at wind speeds
somewhere around 3 to 5 metres per second. This is called the cut in wind
speed. The blue area to the left shows the small amount of power we lose due
to the fact the turbine only cuts in after, say 5 m/s.
通常风机要设计成在某一风速下开始运行,介于 3-5m/s之间。这称为切入风速。
比如说风机只能在 5 m/s之后切入,那么在蓝色面积左侧就显示了我们失去的
少量功率。The Cut Out Wind Speed 切除风速The wind turbine will be programmed to stop at high wind speeds above, say
25 metres per second, in order to avoid damaging the turbine or its
surroundings. The stop wind speed is called the cut out wind speed. The tiny
blue area to the right represents that loss of power.
在某一高风速之上,比如说 25m/s,控制程序将使风机停止运行,以便避免风
机的损坏以及周围环境遭殃。这一停机风速称为切除风速。右侧微小的蓝色面积
表示损失的功率。
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Power curves 功率曲线
The Power Curve of a Wind Turbine 风机的功率曲线The power curve of a wind turbine is a graph that indicates how large the
electrical power output will be for the turbine at different wind speeds.
风机的功率曲线是一张图,它表示风机在不同的风速下有多大的功率输出。
The graph shows a power curve for a typical Danish 600 kW wind turbine.
该图表示了典型的丹麦 600KW风机的功率曲线。Power curves are found by field measurements, where an anemometer is
placed on a mast reasonably close to the wind turbine (not on the turbine itself
or too close to it, since the turbine rotor may create turbulence, and make
wind speed measurement unreliable).
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功率曲线由现场测量得到,风速计装在适度接近风机的塔杆上(不能装在风机
上,也不能离风机太近,因为风机转轮可能产生湍流使得风速测量不可靠)。If the wind speed is not fluctuating too rapidly, then one may use the wind
speed measurements from the anemometer and read the electrical power
output from the wind turbine and plot the two values together in a graph like
the one to the left.
如果风速不急剧波动,那么就可以使用风速计测量风速,并从风机上读出电功
率输出,然后两组数据标在一张图上,如左上图所示。Uncertainty in Measurement of Power Curves 测量功率曲线的不确定性In reality, one will see a swarm of points spread around the blue line, and not
the neat curve in the graph.
事实上,你可以看到一群点散落在蓝线的周围,图上并不是一条干净利索的曲
线。The reason is that in practice the wind speed always fluctuates, and one
cannot measure exactly the column of wind that passes through the rotor of
the turbine.
原因在于,实际上风速总是波动的,人们不可能精确测量到通过风机转轮的风
速。
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(It is not a workable solution just to place an anemometer in front of the
turbine, since the turbine will also cast a "wind shadow" and brake the wind in
front of itself).
(把风速计正好放在风机前边也不是一个好的解决办法,因为风机同时造成了
“风影”,对它前面的风产生了阻碍)。In practice, therefore, one has to take an average of the different
measurements for each wind speed, and plot the graph through these
averages.
因此,实际上你必须取每次风速测量的平均值,并把这些平均值画在图上。Furthermore, it is difficult to make exact measurements of the wind speed
itself. If one has a 3 per cent error in wind speed measurement, then the
energy in the wind may be 9 per cent higher or lower (remember that the
energy content varies with the third power of the wind speed).
此外,精确地测量风速也是很难的。在测量风速中,如果你有 3%的误差那么风
能就会偏高或偏低 9%(记住风能随风速的三次方而变化)。Consequently, there may be errors up to plus or minus 10 per cent even in
certified power curves.
因此,即使是认证的功率曲线,其偏差也可能达到±10%。Verifying Power Curves 核证的功率曲线Power curves are based on measurements in areas with low turbulence
intensity, and with the wind coming directly towards the front of the turbine.
Local turbulence and complex terrain (e.g. turbines placed on a rugged slope)
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may mean that wind gusts hit the rotor from varying directions. It may
therefore be difficult to reproduce the power curve exactly in any given
location.
功率曲线的测量要选在低湍流强度的区域,同时来风要直接朝着风机前面。局部
湍流和复杂的地形(例如,风机放在崎岖不平的斜坡上)可能意味着阵风会从
不同方向上吹向转轮。因此,在任何给定位置精确复制功率曲线可能是很难的。Pitfalls in Using Power Curves 使用功率曲线的陷阱A power curve does not tell you how much power a wind turbine will produce
at a certain average wind speed. You would not even be close, if you used
that method!
功率曲线并没有告诉你,在一定的平均风速下风机会发出多大的功率。如果你使
用那个方法,你甚至会毫无结果。Remember, that the energy content of the wind varies very strongly with the
wind speed, as we saw in the section on the energy in the wind. So, it matters
a lot how that average came about, i.e. if winds vary a lot, or if the wind blows
at a relatively constant speed.
记住,正如在风能一节所看到的,风能随风速而强烈变化。因此,它就与如何进
行平均有很大关系。也就是说,是否风变化很大,是否风以相对恒定的速度刮来Also, you may remember from the example in the section on the power
density function, that most of the wind energy is available at wind speeds
which are twice the most common wind speed at the site.
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并且,由功率密度函数一节中的例子你可能记得,风能的大部分是在那种风速
下获得,该风速是场址最常见风速的两倍。Finally, we need to account for the fact that the turbine may not be running at
standard air pressure and temperature, and consequently make corrections
for changes in the density of air.
最后,我们需要说明的是风机不可能运行在标准的大气压和温度下,因此,需
要对空气密度的变化进行修正。
The power coefficient 功率系数
The Power Coefficient 功率系数The power coefficient tells you how efficiently a turbine converts the energy in
the wind to electricity.
功率系数告诉你,风机将风能转换成电能的效率有多高。
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Very simply, we just divide the electrical power output by the wind energy
input to measure how technically efficient a wind turbine is. In other words, we
take the power curve, and divide it by the area of the rotor to get the power
output per square metre of rotor area. For each wind speed, we then divide
the result by the amount of power in the wind per square metre.
很简单,我们就用电能输出除以风能输入,以便从技术上测量风机有多高的效
率。换句话说,我们用功率曲线除以转轮的面积就得到了每平方米的功率输出。
对于每一风速我们将其结果(电功率)除以每平方米风功率,从而得到风机效
率。The graph shows a power coefficient curve for a typical Danish wind turbine.
Although the average efficiency for these turbines is somewhat above 20 per
cent, the efficiency varies very much with the wind speed. (If there are small
kinks in the curve, they are usually due to measurement errors).
该图表示了典型丹麦风机的功率系数曲线。尽管这些风机的平均效率约 20%以
上,效率却随风速有很大的变化。(如果曲线上有小的扭结,通常是由于测量误
差造成的)。As you can see, the mechanical efficiency of the turbine is largest (in this case
44 per cent) at a wind speed around some 9 m/s. This is a deliberate choice
by the engineers who designed the turbine. At low wind speeds efficiency is
not so important, because there is not much energy to harvest. At high wind
speeds the turbine must waste any excess energy above what the generator
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was designed for. Efficiency therefore matters most in the region of wind
speeds where most of the energy is to be found.
如你所知,当风速约 9 m/s左右时,风机的机械效率是高的(在这个案例是
44%)。这是设计风机的工程师深思熟虑的选择。在低风速时效率不是很重要的
因为反正收获不到很多的能量。在高风速时风机必须消耗掉超出发电机设计所承
受的多余能量。因此,效率要在有最多风能利用的区域加强管理。Higher Technical Efficiency is not Necessarily the Way Forward 更高的技术效率不是必要的推进方式It is not an aim in itself to have a high technical efficiency of a wind turbine.
What matters, really, is the cost of pulling kilowatt hours out of the winds
during the next 20 years. Since the fuel is free, there is no need to save it.
The optimal turbine is therefore not necessarily the turbine with the highest
energy output per year.
要风机有更高的技术效率不是它自身的目标。实际关心的是,在随后的 20年运
行中从风中取得的千瓦小时的成本。因为燃料是不花钱的,没必要节省。因此,
最佳的风机没有必要让它每年有最高的能量输出。On the other hand, each square metre of rotor area costs money, so it is of
course necessary to harvest whatever energy you can - as long as you can
keep costs per kilowatt hour down. We return to that subject later on the page
about optimising wind turbines.
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另一方面,每平方米转轮面积要花钱的,当然有必要收获尽可能多的能量,以
便你能保持千瓦小时成本下降。以后在风机最佳化这一节中,我们再回到这一话
题。
Calculator guide 计算器指南
Guide to the Wind Turbine Power Calculator 风机功率计算器指南If you have room on your screen, you may open another browser window with
the calculator, in order to look at it while you look at this guide.
如果在你的屏幕上有空间,你可以打开具有计算器的另一个浏览器窗口,为了
你看指南时使用。If you do not want to read all of these instructions, please read the advice at the bottom of the page in any case. 在任何情况下,如果你不想阅读所有的指令,请读本页底部的忠告。Using the Power Curve and the Weibull distribution to Estimate Power and Energy Output 利用功率曲线和威布尔分布来估计功率和能量输出。In order to use the power curve properly, you have to combine your
knowledge of the Weibull distribution with the power curve. This is what we
will be doing using the power density calculator on the next page:
为了正确地使用功率曲线,你必须把威布尔分布和功率曲线的知识结合起来。这
就是下一节利用功率密度计算器我们要做的。
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For each tiny 0.1 metre interval of wind speeds we multiply the probability of
that wind speed interval (from the Weibull curve) with the value from the
power curve of the wind turbine.
针对每一微小的 0.1m风速间隔,我们将风速间隔的概率(来自威布尔曲线)
乘以风机功率曲线的值。We then take the sum of all these multiplications to get the mean (or average)
power output.
然后取这些全部乘积之和就得到了平均功率输出。If we multiply the power by 365.25 by 24 (the number of hours in a year) we
get the total energy output for an average year.
如果我们将功率乘以 365.25,再乘以 24(二者之积为一年的小时数)就得到了
年平均总能量输出。Site Data 场址数据Use the pop up menu to fill out European wind distribution data automatically.
The data calculated for roughness classes 0, 1, 2, and 3 was taken from the
European wind atlas. If you use roughness class 1.5, we interpolate to find the
data. If you have data for other parts of the world you would like to have
included, please e-mail us.
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使用弹出的菜单自动地填写出欧洲风能分布数据。粗糙度等级 0,1,2和 3的
计算数据从欧洲风能图谱中取得。如果你选用 1.5的粗糙度等级,可用插值法求
得数据。如果你想用世界其他部分的数据,请给我们发电子邮件。Air Density Data 空气密度数据As we learned on a previous page, the energy in the wind varies in proportion
to the density of air. Try changing the air temperature from, say 40 degrees
Celsius, to -20 degrees Celsius. There are almost 25 per cent more air
molecules in a cubic metre of the cold air than in a cubic metre of the warm
air, so watch what happens to the energy output...
正如我们前节所学的,风能随空气密度按比例变化。试着改变空气温度,比如说
从 40℃变为 20℃。冷空气同热空气相比,每立方米的空气分子数几乎多了
25%,这样看看,对于能量输出发生了什么变化。If you wish to change the altitude above sea level, then start setting the
temperature at sea level first. The programme will then automatically compute
the likely temperature and pressure at the altitude you set.
如果你愿意改变海拔高度,首先开始设定海平面的温度。然后程序会自动计算出
你设定海拔高度的温度和压力。You may set the air density directly, if you know what you are doing. The
programme then computes a likely set of data for the other variables. (You
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may also change the air pressure, but you'd better leave it alone. Your air
pressure obviously has to fit to the local altitude and temperature).
如果你知道你在做什么,你可以直接设定空气密度。然后,程序会计算出一组其
他变量的合理数据。(你也可以改变气压,但是你最好还是不要动它。显然,你
的气压必须适合当地的海拔和温度)。Wind Distribution Data 风能分布数据The Weibull shape parameter is generally around 2 in Northern Europe, but
situations vary, so you may really need a wind atlas to set this more
accurately. You can either enter the mean wind speed, or the Weibull scale
parameter (the programme then automatically computes) the other.
在北欧威布尔的形状参数一般取在 2附近,但是环境是变化的,你实际上可能
需要风能图谱来更精确地设定形状参数。你或者输入平均风速,或者输入威布尔
尺度参数,然后程序自动计算出其他量。The measurement height for your wind speed is very important, because wind
speeds increase with heights above ground level, cf. the page on wind shear.
Meteorology observations are generally made at 10 m height, but
anemometer studies are often made at hub height of the wind turbine (in our
example 50 metres).
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风速的测量高度是很重要的,因为风速随地表之上的高度而增加,参照风剪切
一节。气象观察一般采用 10m高,而风速计的测风研究常常按风机的轮毂高度
(在我们的例子中是 50m)。The average roughness of the surrounding terrain is important to determine
the wind speed at turbine hub height, if it differs from the height at which wind
speed measurements were made. You may either set the roughness length or
the roughness class, depending on the local landscape type. (See the
Reference Manual for guidelines on roughness classes).
如果在不同的高度测风(非轮毂高度),周围地形的平均粗糙度对于风机轮毂
高度风速的确定是重要的。你或者设定粗糙尺度,或者设定粗糙等级,取决于局
部的地貌类型。(见参考手册粗糙度等级指南一节)。Wind Turbine Data 风机数据This section of the calculator lets you specify the rated power of the main
generator, the rotor diameter, the cut in wind speed , and the cut out wind
speed , and the hub height of your machine. At the bottom of the page you
may then specify the power curve of your machine.
计算器的这一部分让你详述主发电机的额定功率、转轮直径、切入风速、切除风
速以及风机的轮毂高度。本页的底部你可以说明这台风机的功率曲线。It is much easier, however, to use the first pop up menu which allows you to
set all turbine specifications using a built-in table of data for typical Danish
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wind turbines. We have already put data for a typical 600 kW machine in the
form for you, but you may experiment by looking at other machines.
但是,这是很容易的。首先使用弹出菜单,借助于内建的典型丹麦风机的数据表
它允许你建立所有风机的说明书。我们已经在表格中为你填上了典型的 600 kW
风机数据,但是你可以看看其他的风机试验一下。The second pop up menu will allow you to choose from the available hub
heights for the machine you have chosen. You may also enter a hub height of
your own, if you wish.
第二次弹出的菜单允许你针对你选用的风机选择可用的轮毂高度。如果你愿意,
你也可以输入自己的轮毂高度。Try experimenting a bit with different hub heights, and see how energy output
varies. The effect is particularly noticeable if the machine is located in terrain
with a high roughness class. (You can modify the roughness class in the wind
distribution data to see for yourself).
再体验一下不同的轮毂高度,观察一下能量输出如何变化。如果风机安装在具有
高粗糙等级的地形,影响是显而易见的。(你可以在风能分布的数据中修改粗糙
度等级,自己看一下结果)。If you modify the standard machine specifications, the text on the first pop up
menu changes to User example, to show that you are not dealing with a
standard machine. It is safe to play with all of the variables, but it does not
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make much sense to change the generator size or rotor diameter for a
standard machine, unless you also change the power curve. We only use the
rotor diameter to show the power input, and to compute the efficiency of the
machine (in terms of the power coefficient). We only use the rated power of
the generator to compute the capacity factor.
如果你修改了标准风机的说明书,首次弹出菜单的文本就变成了用户举例,表
明你没惠顾标准风机。你改变所有变量都是没问题的,但是对标准风机来说如果
你不改变功率曲线,想改变标准风机的发电机的尺寸或者转轮直径是没啥意思
的。我们只用转轮直径演示功率输出并计算风机的效率(利用功率系数)。我们
只用发电机的额定功率去计算容量因子。Wind Turbine Power Curve 风机的功率曲线For practical reasons (keeping your input data and your results in view at the
same time) we have placed the listing of the turbine power curve at the
bottom of the page. You can use this area to specify a turbine which is not
listed in the built-in table. The only requirement is that wind speeds be
ordered sequentially in ascending (increasing) order.
为了实际起见(同时保管好你的输入数据和给出的结果),我们在本页底部放
置一份风机功率曲线的列表。你能利用这一区域指定一台没列在内置表中的风机
唯一的要求是风速要按递增的次序依次排列。The programme approximates the power curve with a straight line between
each two successive points which have non zero values for the power output.
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程序可以利用相邻两点间用直线连接近似地做出功率曲线,这些点的功率输出
不能为零。Note: The programme only uses wind speeds up to 40 m/s in its calculations
of the wind climate, so do not bother about fantasy machines that work
beyond 30 m/s.
注意:在计算风资源时,程序使用的风速最高到 40 m/s,所以不要幻想出一台
机器,它的工作风速超过了 30 m/s。Control Buttons 控制按钮Calculate recalculates the results on the form. You may also click anywhere
else or use the tab key after you have entered data to activate the calculator.
Note that if you change the power curve, the machine will not recalculate your
data until you click calculate, or change other data.
计算并复核表中的结果。在你已经输入了数据并激活了计算器之后,你可以点击
任何地方或使用表格键。注意:如果你改变了功率曲线,机器将不复合你的数据
直到你点击计算或改变其他数据以后。Reset Data sets the data back to the user example you first encountered on
your screen.
重置数据组,数据就返回到,你第一次在显示屏上遇到的用户举例。Power Density plots the power density graph for this site and machine in a
separate window.
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在一个单独的窗口,用功率密度画出了该场址和风机的功率密度图。Power Curve plots the power curve for the machine you have selected in a
separate window.
功率曲线数据画出了你在不同窗口选出风机的功率曲线图。Power Coefficient plots the power coefficient, i.e. the efficiency of the machine
at different wind speeds.
功率系数数据画出了功率系数图,即在不同风速下风机的效率。Site Power Input Results 场址功率输入结果Power input per square metre rotor area shows the amount of energy in the
wind which theoretically would flow through the circle containing the rotor
area, if the rotor were not present. (In reality, part of the airflow will be diverted
outside the rotor area due to the high pressure area in front of the rotor).
每平方米转轮面积的功率输入表示了,假想转轮不存在,理论上流过圆形转轮
面积的风的能量。(实际上,由于转轮前的高压区域,部分气流转移到转轮区域
外)。Maximum power input at x m/s shows at what wind speed we achieve the
highest contribution to total power output. The figure is usually much higher
than average wind speed, cf. the page on the power density function.
在 x m/s时的最大功率输入表明了在那个风速下对总的功率输出达到了最高的
贡献。通常该数字大大高于平均风速,参考功率密度函数一节。
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Mean hub height wind speed shows how the programme recalculates your
wind data to the proper hub height. If you have specified a hub height which is
different from the height at which wind measurements were taken, the
programme automatically recalculates all wind speeds in the Weibull
distribution in accordance with the roughness class (or roughness length) you
have specified.
平均轮毂高度的风速表明,编程如何重新计算恰当的轮毂高度的风速。如果你已
经指定了轮毂高度,而它不同于测风的轮毂高度,编程会根据你指定的粗糙度
等级(或粗糙度尺度)自动重新计算威布尔分布中的所有风速。Turbine Power Output Results 风机的功率输出结果Power output per square metre of rotor area tells us how much of the power
input per square metre the machine will convert to electricity. Generally, you
will find that it is cost effective to build the machine to use about 30 per cent of
the power available. (Please note, that the figure for site power input includes
the power for wind speeds outside the cut in/cut out wind speed range, so you
cannot divide by that figure to obtain the average power coefficient).
每平方米转轮面积的功率输出告诉我们,风机会将多少每平方米的功率输入转
换成了电能。一般说来你会发现,造一台风机能有 30%的风功率可利用就是经
济有效的。(请注意,场址功率输入的数字包括切入、切除风速范围之外的风速
的功率,所以要想得到平均功率系数,你不能除以哪个数字)。
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Energy output per square metre rotor area per year, is simply the mean power
output per square metre rotor area multiplied by the number of hours in a
year.
每平方米转轮面积每年的能量输出,简单说来就是每平方米转轮面积的平均功
率输出乘以一年的小时数。Energy output in kWh per year, tells us how much electrical energy the wind
turbine will produce in an average year. That is probably the figure the owner
cares more about than the rest. When the owner considers that figure,
however, he will also have to take the price of the machine, its reliability, and
the cost of operation and maintenance. We return to those subjects in the
section on the economics of wind energy.
每年以 kWh计的能量输出告诉我们该风机年生产多少电能。这大概是业主比其
他任何数据都更为关心的数字。但是,当业主考虑这一数字时,他也必须考虑机
组的价格、可靠性以及运行维护成本。在风能经济性一节,我们再回到这些话题The annual energy output calculated here may be slightly different from the
real figures from the manufacturer. This is particularly the case if you vary the
density of air. In that case the manufacturer will calculate different power
curves for each density of air. The reason is, that with a pitch controlled
turbine the pitching mechanism will automatically change the pitch angle of
the blade with the change of air density, while for a stall controlled turbine, the
manufacturer will set the angle of the blade slightly differently depending on
the local average air density. This programme may be up to 3.6% below the
correct figure from the manufacturer for low air densities, and up to 1.6%
above the manufacturers' figures for high air densities.
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这里计算的年度能量输出可能与制造商提供的实际数字稍有不同。如果你改变了
空气密度,这就是一个特殊例子。在这种情况下,制造商对每种空气密度将要计
算出不同的功率曲线。原因在于,对于变桨控制的风机变桨机构会随空气密度的
变化自动地改变叶片的桨矩角;而对于定桨控制的风机制造商将设定一个叶片
桨矩角,这个角度将随当地平均空气密度的不同而稍有差别。这一编程数据在低
空气密度时比制造商的正确数字最多低 3.6%;而在高空气密度时比制造商的数
字最多高 1.6%。Capacity factor tells us how much the turbine uses the rated capacity of its
(main) generator. You may read more on the page on annual energy output
from a wind turbine.
容量因子告诉我们机组使用了它的(主)发电机多少份额的额定容量。在风机年
能量输出一节,你可以了解得更多。Note 1: Make sure that you use the same hub height, if you wish to compare
how two machines with the same rotor diameter perform.
注 1:如果你想比较具有同样转轮直径的两台风机的性能,肯定你要采用相同
的轮毂高度。
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Note 2: If you wish to compare machines with different rotor diameters you
should look at the energy output per square metre of rotor area instead (you
should still use the same hub height).
注 2:如果你想比较具有不同转轮直径的机组,就应当考察每平方米转轮面积
的能量输出(你还应当使用相同的轮毂高度)。Note 3: Low wind machines (large rotor diameter relative to generator size)
will generally perform badly at high wind sites and vice versa. Most low wind
machines are not designed for use in high wind areas with strong gusts.
注 3:低风速机组(相对于发电机尺寸而言具有更大的转轮直径)在高风速场
址运行一般说来性能较差,反之亦然。多数低风速机组不是为具有强风的高风速
地区设计的。
The power calculator 功率计算器
Wind Turbine Power Calculator 风机功率计算器Do not operate the form until this page and its programme have loaded
completely.
阅读了本节并把程序完全下载之后,再操作这一表格。
CALCULATOR 计算器
场址数据 选择场址数据
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空气密度数据°C 温度 在 m 海拔高度 (= kPa 压力)
kg/m3 密度
场址的风速分布数据威布尔形状参数
m/s 平均 = 威布尔尺度参数
m 高度, 粗糙度尺度 m = 等级
风机数据 kW 选择风机
m/s 切入风速, m/s 切除风速
m 转轮直径, m轮毂高度 标准高度
计算 其余数据 功率密度 功率曲线
功率系数
场址功率输入结果功率输入* W/m2 转轮面积
最大的功率输入 在* m/s
平均轮毂高度的风速* m/s
风机功率输出结果功率输出* W/m2 转轮面积
能量输出* kWh/m2/year
能量输出* kWh/year
容量因子* %
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风机功率曲线m/s......kW
m/s......kW
m/s......kW
You may experiment by changing the figures in the example. You can fill in
any box, except the result boxes marked with an asterisk (*). After changing
data, use the tab key, click the Calculate button, or click anywhere on the
page outside the field you have updated to see the results. Click on the
question marks for help. (If a plot windows disappears, it is probably hidden
behind this window).
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你可以改变例子中的数字体验一下。除了标有星号(*)的结果空格以外,你能够
填入任何格子。改变数据之后,使用表格键,点击计算按钮,或者点击更新区域
外的页面任何地方,你就会看到结果。Note 1: Energy output results from calculation programmes like this may differ
slightly from the results given by manufacturers.
注 1:从计算编程得到的能量输出结果可能与制造商给出的结果稍有不同。Note 2: Power curves are found by field measurements which may be
uncertain. Therefore these results should be interpreted with great care, as
the may be some +/-10 per cent uncertainty in these measurements.
注 2:现场测量给出的功率曲线可能不够稳定。因此,这些结果应该很仔细地分
析,因为这些测量可能有±10%的不确定性。Note 3: Turbine manufacturers may have site specific turbine models
available which are not listed here.
注 3:风机制造商可能有场址特有的风机模型可以利用,这些模型没在这里列
出。Note 4: The site data below was not chosen as being particularly suitable for
wind turbines, but was taken directly from the anemometer locations used in
the European Wind Atlas. In the case of e.g. Frankfurt (D), one may e.g. find
locations on neighbouring hills with twice as high an annual production as you
would get at the airport where the anemometer is located. In the case of e.g.
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Northwestern Ireland, sites on rounded hills in the area may yield 20-25 per
cent higher energy output.
注 4:选用的下面数据不是专为适于风机使用的,而是从风速计所在位置直接
选取的,这些数据用在欧洲风能图谱上。在法兰克福(D)这一案例,你可以找到
相邻的山丘与安装风速计的机场所在地比较,前者年风能产出可以加倍。在爱尔
兰西北这一案例,圆形山丘上的场址区域可以获得高 20-25%能量输出。Note: This calculator may be used together with the Wind Energy Economics
Calculator. If you open the economics calculator from this page, they will both
be on screen, and this calculator will automatically feed its energy output
result into the economics calculator.
注意:该计算器可以同风能经济计算器联合使用。如果你打开本节的经济计算器
两个计算器都放在屏幕上,本计算器会自动地把它的能量输出结果输入经济计
算器。To print the results of the plotter programme you should make a screen dump
为了打印绘图程序的结果,你应当进行屏幕保存。
Annual energy output 年度能量输出
Annual Energy Output from a Wind Turbine 一台风机的年度能量输出
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We are now ready to calculate the relationship between average wind speeds
and annual energy output from a wind
turbine. To draw the graph to the right,
we have used the power calculator on
the previous page, and the power curve
from the default example 600 kW wind
turbine. We have used a standard
atmosphere with an air density of 1.225
kg/m 3.
现在我们准备计算一台风机的平均风速和年度能量输出的关系。为了画出右边的
图,我们使用前节讲的功率计算器以及默认的 600 kW风机的功率曲线。For each of the Weibull parameters 1.5, 2.0, and 2.5 we have calculated the
annual energy output for different average wind speeds at turbine hub height.
对于每一威布尔参数 1.5, 2.0和 2.5,我们都针对风机轮毂高度的不同平均风速
计算出年度能量输出。As you can see, output may vary up to 50 per cent depending on the shape
parameter at a low average wind speed of 4.5 m/s, while it may vary some 30
per cent at a very high average wind speed of 10 m/s at hub height.
正如你所看到的,在轮毂高度上 4.5 m/s的低平均风速依照形状因子的不同,
输出最大可能有 50%的变化;在轮毂高度上 10 m/s的高平均风速,输出最大可
能有 30%的变化。
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Output varies almost with the cube of the wind speed 输出几乎随风速的立方而变化Now, let us look at the red curve with k=2, which is the curve normally shown
by manufacturers:
现在我们看 k=2的红色曲线,这一般表明是制造商绘制的曲线。With an average wind speed of 4.5 m/s at hub height the machine will
generate about 0.5 GWh per year, i.e. 500,000 kWh per year. With an
average wind speed of 9 metres per second it will generate 2.4 GWh/year =
2,400,000 kWh per year. Thus, doubling the average wind speed has
increased energy output 4.8 times.
对于 4.5 m/s轮毂高度的平均风速,风机将每年发出 0.5 GWh,即每年
500,000 kWh。对于 9 m/s轮毂高度的平均风速,风机将每年发出 2.4 GWh,即
每年 2,400,000kWh。因此,平均风速加倍能量输出将增至 4.8倍。If we had compared 5 and 10 metres per second instead, we would have
obtained almost exactly 4 times as much energy output.
换一组数据,如果我们比较 5m/s和 10m/s的风速,我们会得到几乎多至 4倍
的能量输出。The reason why we do not obtain exactly the same results in the two cases, is
that the efficiency of the wind turbine varies with the wind speeds, as
described by the power curve. Note, that the uncertainty that applies to the
power curve also applies to the result above.
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两个案例我们没精确得到相同的结果,原因在于风机的效率随风速而变化,这
一点在功率曲线一节已讲过。注意,这种不确定性施加于功率曲线,同时也施加
于上述结果。You may refine your calculations by accounting for the fact that e.g. in
temperate climates the wind tends to be stronger in winter than in summer,
and stronger during the daytime than at night.
考虑下述事实可以进一步精确你的计算,例如考虑温度的影响,冬天的风趋向
比夏天强,而白天的风趋向于比晚上强。The Capacity Factor 容量因子Another way of stating the annual energy output from a wind turbine is to look
at the capacity factor for the turbine in its particular location. By capacity factor
we mean its actual annual energy output divided by the theoretical maximum
output, if the machine were running at its rated (maximum) power during all of
the 8766 hours of the year.
讲述风机年度能量输出的另外一个方式就是考察风机在它的指定位置的容量因
子。容量因子意味着实际年度能量输出除以理论上的最大输出。理论上的最大输
出就是假定全年 8766小时风机都在额定(最大)功率运行。Example: If a 600 kW turbine produces 1.5 million kWh in a year, its capacity
factor is = 1500000 : ( 365.25 * 24 * 600 ) = 1500000 : 5259600 = 0.285 =
28.5 per cent.
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例如:如果 600KW风机年生产 150万 kWh电,它的容量因子=1500000 /
( 365.25 * 24 * 600 ) = 1500000 / 5259600 = 0.285 = 28.5%.
Capacity factors may theoretically vary from 0 to 100 per cent, but in practice
they will usually range from 20 to 70 per cent, and mostly be around 25-30 per
cent.
容量因子理论上可以从 0到 100%变化,但实际上它们的取值范围从 20%到
70%,而多数情况围绕 25%至 30%。The Capacity Factor Paradox 容量因子的模糊论点Although one would generally prefer to have a large capacity factor, it may not
always be an economic advantage. This is often confusing to people used to
conventional or nuclear technology.
尽管人们总愿意有一个大的容量因子,但它并不总是有经济上的长处。对于使用
常规能源和核能技术的人们,这一点常常模糊。In a very windy location, for instance, it may be an advantage to use a larger
generator with the same rotor diameter (or a smaller rotor diameter for a given
generator size). This would tend to lower the capacity factor (using less of the
capacity of a relatively larger generator), but it may mean a substantially
larger annual production, as you can verify using the Power calculator on this
web site.
例如,在风很大的场所,对于同样的转轮直径使用大的发电机可能是个优点
(或者对于给定的发电机尺寸使用小的转轮直径)。这会导致低的容量因子(相
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对大的发电机利用的容量较小),但这可能意味着较大的年度能量产出。使用本
网址的功率计算器能够证实这一点。Whether it is worthwhile to go for a lower capacity factor with a relatively
larger generator, depends both on wind conditions, and on the price of the
different turbine models of course.
是否值得采用相对大的发电机以得到较低的容量因子,当然取决于风况,也取
决于不同风机型号的价格。Another way of looking at the capacity factor paradox is to say, that to a
certain extent you may have a choice between a relatively stable power
output (close to the design limit of the generator) with a high capacity factor -
or a high energy output (which will fluctuate) with a low capacity factor.
考察容量因子模糊性的另一种方式为,你可以用一个高的容量因子有相对稳定
的功率输出(接近于发电机的设计极限)或者用一个低的容量因子有高能量输
出(输出将有较大波动)之间在某一范围做出选择。
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How does it work? 风力发电机是如何工作的?
Components 部件
Wind Turbine Components 风力发电机的部件
Click on the parts of the open wind turbine to learn about the nacelle, rotor
blades, hub, low speed shaft, gearbox, high speed shaft with its mechanical
brake, electrical generator, yaw mechanism, electronic controller, hydraulics
system, cooling unit, tower, anemometer and wind vane.
点击图中风力发电机上的部件,学习机舱、转轮叶片、轮毂、低速轴、齿轮箱、高
速轴及机械制动、发电机、偏航机构、电子控制器、液压系统、冷却单元、塔架、风
速计及风向标。
Lift 升力
Aerodynamics of Wind Turbines: Lift
风力发电机的空气动力学:升力
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The rotor consisting of the rotor blades and the hub are placed upwind of the
tower and the nacelle on most modern wind turbines. This is primarily done
because the air current behind the tower is very irregular (turbulent).
转轮由转轮叶片和轮毂组成。由于塔架后方的气流不稳定,所以大多数的现代风
力发电机将转轮叶片和轮毂安装在塔架和机舱的上风向的位置。What makes the rotor turn? 什么使转轮旋转?The answer seems obvious - the wind. 很明显答案是风。But actually, it is a bit more complicated
than just the air molecules hitting the
front of the rotor blades. Modern wind
turbines borrow technologies known from
aeroplanes and helicopters, plus a few
advanced tricks of their own, because
wind turbines actually work in a very different environment with changing wind
speeds and changing wind directions.
但事实上,转轮转动不是简单的空气分子打到转轮叶片的前沿,而要复杂得多。
因为风力发电机要在不同的变化着的风速和风向环境下工作,所以现代的风力
发电机借鉴了飞机和直升机的技术,在加上自身的先进诀窍。Lift 升力
Have a look at the animation of the cut-off
profile (cross section) of the wing of an
aircraft. The reason why an aeroplane can
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fly is that the air sliding along the upper surface of the wing will move faster
than on the lower surface.
查看飞机机翼的切割剖面(横切面)动态。飞机可以飞行的原因是气流沿着机翼
上表面流动要比下表面快。This means that the pressure will be lowest on the upper surface. This creates
the lift, i.e. the force pulling upwards that enables the plane to fly.
这也就意味着上表面的气压低,这样就产生了升力,即压力推动向上,飞机就
可以起飞。The lift is perpendicular to the direction of the wind. The lift phenomenon has
been well known for centuries to people who do roofing work: They know from
experience that roof material on the lee side of the roof (the side not facing
the wind) is torn off quickly, if the roofing material is not properly attached to
its substructure.
这个升力与风向是垂直的。早在一百年前做屋顶工作的人就已经知道这个升力现
象。他们是从实际经验中得知的,如果屋顶材料没有与根基完全的粘合好,背风
面(没有面向风的一边)的屋顶材料就掉得快。
Stall and drag 失速和阻力
Aerodynamics of Wind Turbines: Stall
风力发电机的空气动力学:失速
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Stall 失速Now, what happens if an aircraft tilts
backward in an attempt to climb higher into
the sky quickly? The lift of the wing will
indeed increase, as the wing is tilted
backwards, but in the picture you can see that all of a sudden the air flow on
the upper surface stops sticking to the surface of the wing. Instead the air
whirls around in an irregular vortex (a condition which is also known as
turbulence). All of a sudden the lift from the low pressure on the upper surface
of the wing disappears. This phenomenon is known as stall.
如果飞机向后倾斜迅速向空中升高时会发生什么?由于机翼向后倾斜,机翼的
升力会大大增加,但是在图中你可以看到所有的上表面气流将突然停止,粘着
于机翼的表面,代之而来的是不规则的漩涡流动(称之为湍流的状况)。机翼上表面低压产生的升力将突然消失。这个现象就叫做失速。An aircraft wing will stall, if the shape of the wing tapers off too quickly as the
air moves along its general direction of motion. (The wing itself, of course,
does not change its shape, but the angle of the the wing in relation to the
general direction of the airflow (also known as the angle of attack) has been
increased in our picture above). Notice that the turbulence is created on the
back side of the wing in relation to the air current.
当飞机按照一般飞行方向飞行时,如果机翼形状快速变为锥形,飞机机翼就会
失速。(当然机翼本身是不能改变它的形状的,但是在我们的图片上相对于气流
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方向上的机翼角度(也称为攻角)已经被增加)。注意湍流是在相对于气流的机
翼背面上产生的。Stall can be provoked if the surface of the aircraft wing - or the wind turbine
rotor blade - is not completely even and smooth. A dent in the wing or rotor
blade, or a piece of self-adhesive tape can be enough to start the turbulence
on the backside, even if the angle of attack is fairly small. Aircraft designers
obviously try to avoid stall at all costs, since an aeroplane without the lift from
its wings will fall like a rock.
如果飞机机翼的表面或风力发电机转轮叶片的表面不平滑就会引起失速。即使是
攻角非常小的情况下,机翼或者转轮叶片上的一个凹痕、一块自粘胶带都足以在
后面引起湍流。飞机设计师不惜任何代价尝试消除失速,因为飞机的机翼没有了
升力,就会像石头一样落下。On the page on power control we shall return to the subject of how wind
turbine engineers deliberately make use of the stall phenomenon when
designing rotor blades.
在功率控制一节,我们将再回到风力发电机工程师在设计转轮叶片时是如何故
意利用失速现象这一主题。
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Sum of wind speeds 风速的总和
Aerodynamics of Wind Turbines 风力发电机的空气动力学Adding Wind Speeds and Directions (Wind Velocities) 风速和风向的叠加(风速矢量)
The wind which hits the rotor blades of a wind turbine
will not come from the direction in which the wind is
blowing in the landscape, i.e. from the front of the
turbine. This is because the rotor blades themselves are
moving.
吹向转轮叶片的风不是从后方吹来的,而是从风机前方吹来。因为转轮叶片本身
是在移动的。To understand this, consider the picture of a bicycle which is equipped with a
blue banner (or a wind vane) to indicate the direction of the wind: If we have
completely calm weather, and the bicycles moves forwards, with, say, 7
metres per second (14 knots), the bicycle will be moving through the air at 7
metres per second. On the bicycle we can measure a wind speed of 7 metres
per second relative to the bicycle. The banner will point straight backwards,
because the wind will come directly from the front of the bicycle.
要了解这个,看图中自行车上安装的蓝色小旗(风向标)就明确指示了风的方
向。
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如果在完全没有风的天气下,自行车以 7米每秒的速度向前行驶(14里/小时),
那么自行车穿过空气的速度就是 7米每秒。在自行车上我们测量到的 7米每秒的
风速是相对于自行车而言的。因为风是从自行车前方吹来的,所以自行车上的小
旗会指向正后方。Now, let us look at the bicycle again directly from above, and let us assume
that the bicycle moves forward at a constant speed of, once
again, 7 metres per second. If the wind is blowing directly from
the right, also at 7 metres per second, the banner will clearly
be blown partly to the left, at a 45 degree angle relative to the
bicycle. With a bit less wind, e.g. 5 metres per second, the
banner will be blown less to the left, and the angle will be some
35 degrees. As you can see from the picture, the direction of
the wind, the resulting wind as measured from the bicycle, will change
whenever the speed of the wind changes.
现在,我们再从自行车的正上方观察,假定自行车以 7米每秒匀速运动。如果风
以 7米每秒的速度从右侧吹来,很明显的小旗会被吹向自行车左侧 45度角的方
向。如果风速减小到 5米每秒,那么小旗就会被吹向左侧 35度角的方向。从图
中可以看到,从自行车上测量的风向会随着风速而改变。What about the wind speed measured from the bicycle?
从自行车上测量的风速会是多少呢?
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The wind is, so to speak, blowing at a rate of 7 metres per second from the
front and 5 to 7 metres per second from the right. If you know a bit of
geometry or trigonometry you can work out that the wind speed measured on
the bicycle will be between 8.6 and 9.9 metres per second.
可以这么说,从前方吹来的风是 7米每秒的速度,从右侧吹来的是 5-7米每秒
的速度。如果你懂得一点几何学或三角法,你就可以计算出在自行车上测量出的
风速是在 8.6到 9.9米每秒之间。Enough about changing wind directions, now what about the wind turbine
rotor?
改变风向说得够多了,那么风力发电机的转轮又如何呢?
Rotor aerodynamics 转轮空气动力学
Rotor Aerodynamics 转轮空气动力学To study how the wind moves relative to the rotor blades of a wind turbine, we
have fixed red ribbons to the tip of the rotor blades of our model wind turbine,
and yellow ribbons some 1/4 out the length of the blade from the hub.
要学习风相对于风力发电机的转轮叶片是如何运动的,我们可以在模型的风力
发电机转轮叶片顶端固定红色的绸带,在叶片的 1/4处靠近轮毂的位置固定黄
色绸带。
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We then let the ribbons float freely in the air
(in the cartoon we abstract from the air
currents created by the blades themselves,
and the centrifugal force).
我们让绸带在空中自由飘动。(在动画中我们
将气流提取出来:气流是靠叶片自身和地心
引力产生的。)The two images on this page give you one view from the side of the turbine,
and another view from the front of the turbine.
图中的两幅画面给出一个风机的侧面,另一个是风机的正面。Since most wind turbines have constant rotational speed, the speed with
which the tip of the rotor blade moves through the air (the tip speed) is
typically some 64 m/s, while at the centre of the hub it is zero. 1/4 out the
length of the blade, the speed will then be some 16 m/s.
大部分的风力发电机有恒定的转动速度,转轮叶片的尖端转动速度(叶尖速
度)典型是 64 m/s,然而轮毂的中心速度是 0,叶片长度 1/4以外处速度大约
是 16 m/s。The yellow ribbons close to the hub of the rotor will be blown more towards
the back of the turbine than the red ribbons at the tips of the blades. This is
obviously because at the tip of the blades the speed is some 8 times higher
than the speed of the wind hitting the front of the turbine.
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靠近转轮轮毂的黄色绸带向风机后方吹到的风要比叶尖的红色绸带吹到的多。很
明显是由于叶片尖端的风速要比从风机前面吹来的风速高出 8倍。Why are Rotor Blades Twisted? 转轮叶片为什么扭曲?Rotor blades for large wind turbines are always twisted. 大风机的转轮叶片总
是扭曲的。Seen from the rotor blade, the wind will be coming from a much steeper angle
(more from the general wind direction in the landscape), as you move towards
the root of the blade, and the centre of the rotor.
当你移向叶片根部和转轮的中心,从转轮叶片看,风是从一个陡峭的角度吹来。
(更多是来自一般的地貌风向)As you learned on the page on stall, a rotor blade will stop giving lift, if the
blade is hit at an angle of attack which is too steep.
从失速一节中学到,如果风从一个陡峭的攻角吹向叶片,那么转轮叶片就会失
去升力。Therefore, the rotor blade has to be twisted, so as to acheive an optimal angle
of attack throughout the length of the blade. However, in the case of stall
controlled wind turbines in particular, it is important that the blade is built so
that it will stall gradually from the blade root and outwards at high wind
speeds.
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因此,转轮叶片扭曲就可以使整个叶片长度都达到最佳的攻角。特别是失速控制
风力发电机,叶片的设计是很重要的,就可以使得在高风速时,从叶片的根部
往外会逐渐产生失速。
Rotor blades 转轮叶片
Rotor Blades 转轮叶片
Changing the Wind Speed Changes Wind Direction Relative to the Rotor Blade 改变风速就改变了相对于转轮叶片的风向In this next picture we have taken one rotor blade from the previous page off
its hub, and we look from the hub towards the tip, at the back side (the lee
side) of the rotor blade. The wind in the landscape blows between, say 8 m/s
and 16 m/s (from the bottom of the picture), while the tip of the blade rotates
towards the left side of the picture.
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在这个图片中,我们是从上一节的图中选取轮毂中一个叶片,在叶片被风的一
边(背风面),我们从轮毂往尖端看。图中当叶片尖端朝向左边时,地貌风速在
8m/s到 16m/s之间(从图片的底部)。In the picture you can see how the angle of attack of the wind changes much
more dramatically at the root of the blade (yellow line) than at the tip of the
blade (red line), as the wind changes. If the wind becomes powerful enough to
make the blade stall , it will start stalling at the root of the blade.
在图中你可以看到,风改变时,在叶片根部(黄线)攻角的变化要比叶片尖端
(红线)攻角的变化更加明显。如果风的力量足够大,就可以使得叶片失速,在
叶片的根部开始失速。Lift Direction 升力的方向Now, let us cut the rotor blade at the point with the yellow line. In the next
picture the grey arrow shows the direction of
the lift at this point. The lift is perpendicular to
the direction of the wind. As you can see, the
lift pulls the blade partly in the direction we
want, i.e. to the left. It also bends the rotor
blade somewhat, however.
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现在,我们在黄线的位置切开转轮叶片。在下图片中,灰色箭头指明了这个位置
的升力方向。升力的方向与风的方向是垂直的。像你看到的,升力将叶片拉到了
我们想要的方向,也就是左边。然而它也可以使叶片稍微弯曲。Rotor Blade Profiles (Cross Sections) 转轮叶片剖面(横切面)As you can see, wind turbine rotor blades look a lot like the wings of an
aircraft. In fact, rotor blade designers often use classical aircraft wing profiles
as cross sections in the outermost part of the blade.
像你所看到的,风机转轮叶片看起来很像飞机机翼。事实上,转轮叶片的设计师
常常采用经典的飞机机翼形状作为叶片最外部的横切面。The thick profiles in the innermost part of the blade, however, are usually
designed specifically for wind turbines. Choosing profiles for rotor blades
involves a number of compromises including reliable lift and stall
characteristics, and the profile's ability to perform well even if there is some
dirt on the surface (which may be a problem in areas where there is little rain).
在叶片最里面部分的厚的剖面通常为特殊风机设计。为转轮叶片选择剖面包括
很多的折中:可靠的升力、失速特征和即使在表面有一点污垢也能更好展示剖面
性能(可能在少雨的地区有的问题)Rotor Blade Materials 转轮叶片材料Most modern rotor blades on large wind turbines are made of glass fibre
reinforced plastics, (GRP), i.e. glass fibre reinforced polyester or epoxy.
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大多数现代的大风机转轮叶片都采用玻璃纤维增强固型塑料(GPR)也就是玻
璃纤维增强聚酯或环氧。Using carbon fibre or aramid (Kevlar) as reinforcing material is another
possibility, but usually such blades are uneconomic for large turbines.
另外一个可能是使用碳纤维或一种人造纤维(凯芙拉)作为增强型材料,但是
通常在大风机上用这种叶片经济性不好。Wood, wood-epoxy, or wood-fibre-epoxy composites have not penetrated the
market for rotor blades, although there is still development going on in this
area. Steel and aluminium alloys have problems of weight and metal fatigue
respectively. They are currently only used for very small wind turbines.
木质、木环氧或者是木纤维环氧合成物虽然一直在朝这个领域发展,但是还未能
进入风机叶片市场。钢和铝合金分别存在重量和金属疲劳问题,它们目前仅用在
小风机上。
Power control 功率控制
Power Control of Wind Turbines 风力发电机的功率控制Wind turbines are designed to produce electrical energy as cheaply as
possible. Wind turbines are therefore generally designed so that they yield
maximum output at wind speeds around 15 metres per second. (30 knots or
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33 mph). Its does not pay to design turbines that maximise their output at
stronger winds, because such strong winds are rare.
设计 风力发电机是用来尽可能便宜的发电。因此通常设计的风力发电机能够在
风速达到 15m/s(30哩/小时或 33英里/小时)左右的时候产生出最大输出功率。
不需要花钱设计风机在更强的风时有最大的功率输出,因为这种强风是很少的。In case of stronger winds it is necessary to waste part of the excess energy of
the wind in order to avoid damaging the wind turbine. All wind turbines are
therefore designed with some sort of power control. There are two different
ways of doing this safely on modern wind turbines.
为了避免破坏风机,在遇有更强风时就需要浪费掉产生的部分过剩能量。所有的
风机都设计有某种功率控制器。关于现代风机的安全有两种不同的做法。Pitch Controlled Wind Turbines 变桨控制风力发电机
On a pitch controlled wind turbine the turbine's electronic
controller checks the power output of the turbine several times
per second. When the power output becomes too high, it sends
an order to the blade pitch mechanism which immediately
pitches (turns) the rotor blades slightly out of the wind. Conversely, the blades
are turned back into the wind whenever the wind drops again.
在一个变桨控制风力发电机上,发电机的电子控制器每秒钟要检查发电机的输
出功率数次。当输出功率特别高时,就会向叶片的变桨机构发出一个命令,立即
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轻微地变桨(转动)使转轮叶片背风。相反的如果风又变弱,叶片就会转动回来
迎风。The rotor blades thus have to be able to turn around their longitudinal axis (to
pitch) as shown in the picture.
像图片中显示的转轮叶片可以绕着它的纵向轴转动(变桨)。
Note, that the picture is exaggerated: 注意,那个图片是夸大了的:During normal operation the blades will pitch a fraction of a degree at a time -
and the rotor will be turning at the same time.
在正常运转期间叶片每次变桨一个小角度,转轮同时也转动。Designing a pitch controlled wind turbine requires some clever engineering to
make sure that the rotor blades pitch exactly the amount required. On a pitch
controlled wind turbine, the computer will generally pitch the blades a few
degrees every time the wind changes in order to keep the rotor blades at the
optimum angle in order to maximise output for all wind speeds.
设计一个变桨控制风力发电机要求一些精通的工程学知识以确保转轮叶片变桨
要求的精确性。每当风变化时,变桨控制风力发电机的计算机会使叶片变桨一定
角度以保持转轮叶片在不同风速下以最佳的角度产生最大功率。The pitch mechanism is usually operated using hydraulics.
变桨机构通常利用液压技术运行。
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Stall Controlled Wind Turbines 失速控制的风力发电机(Passive) stall controlled wind turbines have the rotor blades bolted onto the
hub at a fixed angle.
(被动的)失速控制的风力发电机要求转轮叶片以一个固定的角度将叶片用螺
栓固定到轮毂上。The geometry of the rotor blade profile, however has been aerodynamically
designed to ensure that the moment the wind speed becomes too high, it
creates turbulence on the side of the rotor blade which is not facing the wind
as shown in the picture on the previous page. This stall prevents the lifting
force of the rotor blade from acting on the rotor.
转轮叶片剖面的几何形状已经按空气动力学设计,以确保风速变到太高的时刻,
在转轮叶片的背风的一边产生湍流,如上一节中图片中所示。这个失速阻止了来
自作用于转轮的转轮叶片的升力。If you have read the section on aerodynamics and aerodynamics and stall,
you will realise that as the actual wind speed in the area increases, the angle
of attack of the rotor blade will increase, until at some point it starts to stall.
如果你阅读了关于空气动力学和空气动力学与失速章节,你就会明白在区域的
实际风速增加时,转轮叶片的攻角也会增加,直到在某一点开始失速。If you look closely at a rotor blade for a stall controlled wind turbine you will
notice that the blade is twisted slightly as you move along its longitudinal axis.
This is partly done in order to ensure that the rotor blade stalls gradually
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rather than abruptly when the wind speed reaches its critical value. (Other
reasons for twisting the blade are mentioned in the previous section on
aerodynamics).
如果你近距离看一个失速控制风力发电机的转轮叶片,当你沿着它的纵向轴移
动你就会注意到叶片稍有扭曲。这样做是为了确保当风速达到临界值时,转轮叶
片逐渐失速而不是突然失速。(叶片扭曲的另一个原因在之前的空气动力学一节
已经提到)The basic advantage of stall control is that one avoids moving parts in the
rotor itself, and a complex control system. On the other hand, stall control
represents a very complex aerodynamic design problem, and related design
challenges in the structural dynamics of the whole wind turbine, e.g. to avoid
stall-induced vibrations. Around two thirds of the wind turbines currently being
installed in the world are stall controlled machines.
失速控制的基本优点一是可以避免转轮本身的移动,也避免了一个复杂的控制
系统。另外一方面,失速控制体现了一个非常综合的空气动力学设计问题和整个
风机的相关结构力学的挑战,例如避免失速引起的振动。在世界上安装的大约
2/.3的风机普遍是失速控制风机。Active Stall Controlled Wind Turbines 主动失速控制风力发电机An increasing number of larger wind turbines (1 MW and up) are being
developed with an active stall power control mechanism.
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越来越多的大风机(1MW以上)发展使用主动失速功率控制装置。Technically the active stall machines resemble pitch controlled machines,
since they have pitchable blades. In order to get a reasonably large torque
(turning force) at low wind speeds, the machines will usually be programmed
to pitch their blades much like a pitch controlled machine at low wind speeds.
(Often they use only a few fixed steps depending upon the wind speed).
主动失速装置技术上类似于变桨控制装置,因为它们有变桨叶片。为了在低风速
时达到合适的大的转距(旋转力),装置会编程使它的叶片变桨就像在低风速
变桨控制风机一样。(它们常常依据风速使用几个固定步骤)When the machine reaches its rated power, however, you will notice an
important difference from the pitch controlled machines: If the generator is
about to be overloaded, the machine will pitch its blades in the opposite
direction from what a pitch controlled machine does. In other words, it will
increase the angle of attack of the rotor blades in order to make the blades go
into a deeper stall, thus wasting the excess energy in the wind.
当风机达到它的额定功率,你就会注意到一个非常重要的与变桨控制装置的差
异:如果发电机接近超负荷,叶片就会向与变桨控制风机相反的方向变桨。换句
话说,它就会增加转轮叶片的攻角,以使得叶片更加失速,从而消耗风中的过
剩能量。
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One of the advantages of active stall is that one can control the power output
more accurately than with passive stall, so as to avoid overshooting the rated
power of the machine at the beginning of a gust of wind. Another advantage is
that the machine can be run almost exactly at rated power at all high wind
speeds. A normal passive stall controlled wind turbine will usually have a drop
in the electrical power output for higher wind speeds, as the rotor blades go
into deeper stall.
主动失速的优点一是能够比被动失速更加准确的控制输出功率,以避免在一阵
大风开始的时候超过额定功率。另外一个优点是能够在所有高风速时基本上以额
定功率运行。一般被动失速控制风力发电机通常在较大风速时输出功率会下跌,
因为转轮叶片进入较深失速。The pitch mechanism is usually operated using hydraulics or electric stepper
motors.
变桨装置通常使用液压技术或电子的步进电动机运行。As with pitch control it is largely an economic question whether it is worthwhile
to pay for the added complexity of the machine, when the blade pitch
mechanism is added.
安装变桨控制主要是经济问题,当增加叶片变桨机构是否值得支付装置额外的
复杂性应予权衡。Other Power Control Methods 其他功率控制方法
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Some older wind turbines use ailerons (flaps) to control the power of the rotor,
just like aircraft use flaps to alter the geometry of the wings to provide extra lift
at takeoff.
一些老的风力发电机使用副翼(阻力板)来控制转轮的功率,就像飞机使用阻
力板来改变机翼的几何图形以提供起飞时额外的升力。Another theoretical possibility is to yaw the rotor partly out of the wind to
decrease power. This technique of yaw control is in practice used only for tiny
wind turbines (1 kW or less), as it subjects the rotor to cyclically varying stress
which may ultimately damage the entire structure.
另外一种理论上的可能性是使转轮偏航背离风以减少功率。这个偏航控制的技术
在实际中只是用于一些小风机(1KW以下),因为它的转轮主体循环变动应力,
最终可能会损坏整个结构。
The yaw mechanism 偏航机构
The Wind Turbine Yaw Mechanism 风力发电机偏航机构The wind turbine yaw mechanism is used to turn the
wind turbine rotor against the wind.
风力发电机偏航机构用来转动风机转轮以便对准风。Yaw Error 偏航误差
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The wind turbine is said to have a yaw error, if the rotor is not perpendicular to
the wind. A yaw error implies that a lower share of the energy in the wind will
be running through the rotor area. (The share will drop to the cosine of the
yaw error, for those of you who know math).
如果转轮与风不垂直,风机就会有一个偏航误差。一个偏航误差意味着风中一部
分能量会穿过转轮区域。(你懂得数学就会知道这部分会下降到偏航误差的余弦
值)If this were the only thing that happened, then yaw control would be an
excellent way of controlling the power input to the wind turbine rotor. That part
of the rotor which is closest to the source direction of the wind, however, will
be subject to a larger force (bending torque) than the rest of the rotor. On the
one hand, this means that the rotor will have a tendency to yaw against the
wind automatically, regardless of whether we are dealing with an upwind or a
downwind turbine. On the other hand, it means that the blades will be bending
back and forth in a flapwise direction for each turn of the rotor. Wind turbines
which are running with a yaw error are therefore subject to larger fatigue loads
than wind turbines which are yawed in a perpendicular direction against the
wind.
如果只有这一个事情发生,那么偏航控制是风力发电机转轮功率输入控制的最
好方法。靠近风向来源的那部分转轮要比其他部分的转轮遭受更大的力量(弯曲
扭矩)。一方面意味着转轮会有一个自动偏航趋势来对准风,不管我们是否安置
一个上风向或下风向风机。另一方面也意味着每次转轮转动,叶片就会在阻力板
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的方向上来回弯曲。因此有偏航误差的风力发电机要比在垂直迎风偏航的风力发
电机承受更大的疲劳载荷。Yaw Mechanism 偏航装置
Photograph Soren Krohn© 1998 DWIA
Soren Krohn拍摄
Almost all horizontal axis wind turbines use forced yawing, i.e. they use a
mechanism which uses electric motors and gearboxes to keep the turbine
yawed against the wind.
几乎所有的水平轴风力发电机都使用强制偏航,也就是使用电机和齿轮箱来保
持风机偏航以便对准风。The image shows the yaw mechanism of a typical 750 kW machine seen from
below, looking into the nacelle. We can see the yaw bearing around the outer
edge, and the wheels from the yaw motors and the yaw brakes inside. Almost
all manufacturers of upwind machines prefer to brake the yaw mechanism
whenever it is unused. The yaw mechanism is activated by the electronic
controller which several times per second checks the position of the wind
vane on the turbine, whenever the turbine is running.
这个图片展示了一个典型的 750 kW风机的偏航装置,从底下观察机舱。我们可
以看到在外缘的偏航轴承,偏航电机轮和偏航刹车在里面。几乎所有的上风向生
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产厂家只要没有使用过就都喜欢偏航刹车装置。偏航装置是由电子控制器激活,
每当风机运行的时候,电子控制器每秒就会检查几次风机上风向标的位置。Cable Twist Counter 电缆缠绕计数器Cables carry the current from the wind
turbine generator down through the tower.
The cables, however, will become more and
more twisted if the turbine by accident keeps
yawing in the same direction for a long time.
The wind turbine is therefore equipped with a cable twist counter which tells
the controller that it is time to untwist the cables.
电缆将电流从风力发电机传送到塔架。然而如果风机长时间保持一个方向偏航,
电缆就会越来越缠绕。风机安装了电缆缠绕计数器就可以告诉控制器到了解开电
缆缠绕的时间。Occasionally you may therefore see a wind turbine which looks like it has
gone berserk, yawing continuously in one direction for five revolutions.
偶尔你可以看到风机偏航在一个方向连续旋转 5 次,看起来就像风机疯狂地运
行。Like other safety equipment in the turbine there is redundancy in the system.
In this case the turbine is also equipped with a pull switch which is activated if
the cables become too twisted.
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像风机中其他安全设备一样,系统中有冗余。在这种情况下,风机也安装一个拉
闸开关,如果电缆缠绕过多就会被激活。
Towers 塔架
Wind Turbine Towers 风力发电机塔架Wind turbine towers,
Navarra, Spain Photograph Soren
Krohn© 1999 DWIA
西班牙 Navarra 风力发电机塔架,Soren Krohn 拍摄
The tower of the wind turbine carries the nacelle and the rotor.
风机的塔架承载着机舱和转轮。Towers for large wind turbines may be either tubular steel towers, lattice
towers, or concrete towers. Guyed tubular towers are only used for small wind
turbines (battery chargers etc.)
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大风机的塔架有管状钢制塔架、桁架或混凝土塔架。拉索管状塔架只用于小风机
(蓄电池充电器等)Tubular Steel Towers 管状钢制塔架Most large wind turbines are delivered with tubular steel towers, which are
manufactured in sections of 20-30 metres with
flanges at either end, and bolted together on the
site. The towers are conical (i.e. with their
diameter increasing towards the base) in order to
increase their strength and to save materials at the same time.
大多数的大风机都使用管状钢制塔架,每截 20-30米,两端有法兰,并在现场
用螺栓紧固在一起。塔架是圆锥型的(也就是它的直径向根部方向越来越大),
是为了增加力量,同时节省材料。Lattice Towers 桁架塔Lattice towers are manufactured using welded steel
profiles. The basic advantage of lattice towers is cost,
since a lattice tower requires only half as much material as
a freely standing tubular tower with a similar stiffness. The
basic disadvantage of lattice towers is their visual
appearance, (although that issue is clearly debatable). Be
that as it may, for aesthetic reasons lattice towers have almost disappeared
from use for large, modern wind turbines.
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桁架的制作是使用焊接钢铁外形。桁架的基本优点是成本,一个桁架需求的原材
料是相同硬度的直立管状塔架的一半。桁架的基本缺点是外观,(虽然使用是无
可争议的)不管怎样,由于美学的原因,桁架几乎没有用于现代的大风机。Guyed Pole Towers 拉索杆塔架
Many small wind turbines are built with narrow pole
towers supported by guy wires. The advantage is weight
savings, and thus cost. The disadvantages are difficult
access around the towers which make them less
suitable in farm areas. Finally, this type of tower is more
prone to vandalism, thus compromising overall safety.
许多小风机使用靠金属拉索支撑的细杆塔架建筑。优点是减轻重量,因而成本降
低。缺点是在塔架周围难以进入,使得它们很少适应
于农场区域。最后,这种类型的塔架更容易被破坏,
从而影响整体安全性。Hybrid Tower Solutions 混合塔架方案Some towers are made in different combinations of the techniques mentioned
above. One example is the three-legged Bonus 95 kW tower which you see in
the photograph, which may be said to be a hybrid between a lattice tower and
a guyed tower. Photograph Soren Krohn © 1999 DWIA Soren Krohn拍摄
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很多塔架是用上述提到的的不同混合技术制成。例如,在图中看到的三个支架的
95KW 风机塔架,就是由桁架和拉索塔架混合而成。Cost Considerations 成本考虑The price of a tower for a wind turbine is generally around 20 per cent of the
total price of the turbine. For a tower around 50 metres' height, the additional
cost of another 10 metres of tower is about 15,000 USD. It is therefore quite
important for the final cost of energy to build towers as optimally as possible.
一个风机塔架的价格一般占整个风机价格的大约 20%。一个大约 50米高的塔架
每 10米高塔架的附加成本为 15,000 美元左右。因此,建立尽可能优化的塔架,
对于最终的能源成本它是相当重要的。Lattice towers are the cheapest to manufacture, since they typically require
about half the amount of steel used for a tubular steel tower.
拉索塔架建造是最便宜的,因为它通常要比管状铁质塔架所需要的钢铁数量少
一半。Aerodynamic Considerations 空气动力学考虑Generally, it is an advantage to have a tall tower in areas with high terrain
roughness, since the wind speeds increases farther away from the ground, as
we learned on the page about wind shear.
一般来说,在一个崎岖不平的高地形地区建造高塔架是一个优势,因为远离地
面风速会增加,这个我们在风切变一节中得知。182
Lattice towers and guyed pole towers have the advantage of giving less wind
shade than a massive tower.
桁架和拉索杆塔架的优点是对风的遮挡要少于一个厚重的塔架。Structural Dynamic Considerations 结构动力学考虑The rotor blades on turbines with relatively short towers will be subject to very
different wind speeds (and thus different bending) when a rotor blade is in its
top and in its bottom position, which will increase the fatigue loads on the
turbine.
在塔架相对短的风机上,当一个转轮叶片在塔架的顶部和底部位置的时候,转
轮叶片将承受非常不同的风速(因此弯曲度不同),这样就会增加风机的疲劳
载荷。Choosing Between Low and Tall Towers 在低塔架和高塔架之间选择
Obviously, you get more energy from a larger wind turbine than a small one,
but if you take a look at the three wind turbines below, which are 225 kW, 600
kW, and 1,500 kW respectively, and with rotor diameters of 27, 43, and 60
metres, you will notice that the tower heights are different as well.
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很明显的,大风机要比小风机获得的能量多,但是如果你观察如下三个风机,
分别是 225 kW、600 kW、和 1,500 kW,转轮直径分别是 27、43和 60米,你会
发现塔架的高度完全不同。Clearly, we cannot sensibly fit a 60 metre rotor to a tower of less than 30
metres. But if we consider the cost of a large rotor and a large generator and
gearbox, it would surely be a waste to put it on a small tower, because we get
much higher wind speeds and thus more energy with a tall tower. (See the
section on wind resources). Each metre of tower height costs money, of
course, so the optimum height of the tower is a function of
1. tower costs per metre (10 metre extra tower will presently cost you about
15,000 USD)
2. how much the wind locally varies with the height above ground level, i.e.
the average local terrain roughness (large roughness makes it more
useful with a taller tower),
3. the price the turbine owner gets for an additional kilowatt hour of
electricity.
很明显的,我们不能在一个 30米以下的塔架上安装直径 60米的转轮。但是如果
考虑到一个大转轮和一个大发电机与齿轮箱的成本,放在一个小塔架上就有点
浪费,因为一个高塔架我们可以获得更大的风速和更多的能源。(阅读风资源一
节)。每一米的塔架高度都花费资金,当然最佳的的塔架高度是如下函数:
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1. 每米塔架成本(额外的 10米塔架你就要多花费大约 15,000 美元)
2. 当地多少风随地平面上的高度而变化,即当地地形的平均粗糙度(粗糙度大
对高的塔架越有利),
3. 风机业主获得额外的千瓦小时的电力价格。Manufacturers often deliver machines where the tower height is equal to the
rotor diameter. aesthetically, many people find that turbines are more pleasant
to look at, if the tower height is roughly equal to the rotor diameter.
制造商常常提供塔架高度与转轮直径一样的机器。从美学角度看,许多人认为如
果塔架高度和转轮直径基本一样的风机更加美观。Occupational Safety Considerations 职业安全考虑The choice of tower type has consequences for occupational safety: This is
discussed in detail on the page on Wind Turbines and Occupational Safety.
塔架种类的选择对职业安全有重要作用。这点在风力发电机和职业安全一节中详
细讨论。
The size of turbines 风机尺寸
Size of Wind Turbines 风力发电机尺寸
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Service crew working on a 32 m rotor blade on a 1.5 MW wind turbine Photograph Christian Kjaer© 2000 DWIA维修工作人员在 1.5MW风力发电机的 32米长的转轮叶片上工作。Christian Kjaer拍摄Power Output Increases with the Swept Rotor Area 输出功率随转轮扫风面积增加When a farmer tells you how much land
he is farming, he will usually state an
area in terms of hectares or acres. With a
wind turbine it is much the same story,
though doing wind farming we farm a
vertical area instead of a horizontal one.
当一个农夫告诉你他耕种多大面积的土地,
他通常用公顷或英亩说明面积。风力发电机也是同样的道理,只是我们耕作一个
风场,以垂直的面积代替水平面积。The area of the disc covered by the rotor, (and wind speeds, of course),
determines how much energy we can harvest in a year.
转轮覆盖区域(当然还有风速)决定了一年我们可以获得多少能源。The picture gives you an idea of the normal rotor sizes of wind turbines: A
typical turbine with a 600 kW electrical generator will typically have a rotor
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diameter of some 44 metres (144 ft.). If you double the rotor diameter, you get
an area which is four times larger (two squared). This means that you also get
four times as much power output from the rotor.
图片给出了风机的标准转轮尺寸:一个典型的 600KW风机的转轮直径大约是
44米(144英尺)。如果你将转轮直径扩大两倍,你就会得到一个四倍大的面
积(2的平方)。也就是说转轮输出功率成为四倍。Rotor diameters may vary somewhat from the figures given above, because
many manufacturers optimise their machines to local wind conditions: A larger
generator, of course, requires more power (i.e. strong winds) to turn at all. So
if you install a wind turbine in a low wind area you will actually maximise
annual output by using a fairly smallgenerator for a given rotor size (or a
larger rotor size for a given generator) For a 600 kW machine rotor diameters
may vary from 39 to 48 m (128 to 157 ft.) The reason why you may get more
output from a relatively smaller generator in a low wind area is that the turbine
will be running more hours during the year.
从上述的数字看,转轮直径可能会略有不同,因为考虑当地的风力条件许多制
造商优化他们的风机:大的发电机当然需要更多的功率(即强风)转化。因此,
如果你在低风区安装风力发电机,实际上对于给定的转轮尺寸你可以用较小的
风力发电机(或者给定发电机用较大的转轮尺寸)来优化年产量。对于 600 kW
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的转轮直径从 39到 48米(128到 157英尺)变化。在低风区从一个小的发电机
可以获得更多产量的原因是在这一年中风机运行的时间会更长久。Reasons for Choosing Large Turbines 选择大风机的原因1. There are economies of scale in wind turbines, i.e. larger machines are
usually able to deliver electricity at a lower cost than smaller machines.
The reason is that the cost of foundations, road building, electrical grid
connection, plus a number of components in the turbine (the electronic
control system etc.), are somewhat independent of the size of the
machine.
在风机中要有规模经济,也就是大风机供电成本通常要比小风机小。原因是基础
道路建设、电网连接加上风机中的许多部件(电控系统等)的成本不完全取决于
风机的尺寸。2. Larger machines are particularly well suited for offshore wind power. The
cost of foundations does not rise in proportion to the size of the machine,
and maintenance costs are largely independent of the size of the
machine.
大风机很适合于海上风电。基础成本与风机尺寸不是成比例上升的,维修费用很
大程度上也不依赖于风机尺寸。3. In areas where it is difficult to find sites for more than a single turbine, a
large turbine with a tall tower uses the existing wind resource more
efficiently.
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在很难找到安装多台风机的场址的区域,采用高塔架的大风机使用现有风资源
更加有效。You may take a look at some megawatt-sized wind turbines in the picture
gallery.
你可以看看一些在图片库中的兆瓦级风力发电机。Reasons for Choosing Smaller Turbines 选择小风机的原因1. The local electrical grid may be too weak to handle the electricity output
from a large machine. This may be the case in remote parts of the
electrical grid with low population density and little electricity consumption
in the area.
当地电网可能太弱不能接收大风机的电产量。这种情况可能会在人口密度低、电
耗少的偏远电网地区出现。2. There is less fluctuation in the electricity output from a wind park
consisting of a number of smaller machines, since wind fluctuations occur
randomly, and therefore tend to cancel out. Again, smaller machines may
be an advantage in a weak electrical grid.
由几个小风机组成的风电场产生的电能波动较小,因为风的波动是随机出现的,
因此可以抵消。此外,小风机在弱电网使用是优势。3. The cost of using large cranes, and building a road strong enough to carry
the turbine components may make smaller machines more economic in
some areas.
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在一些区域使用大起重机的成本,建造坚硬的道路以便运输风机部件都使小风
机使用更加经济。4. Several smaller machines spread the risk in case of temporary machine
failure, e.g. due to lightning strikes.
如果发生机器临时故障,几个小风机就扩大风险,例如由于雷击。5. aesthetical landscape considerations may sometimes dictate the use of
smaller machines. Large machines, however, will usually have a much
lower rotational speed, which means that one large machine really does
not attract as much attention as many small, fast moving rotors. (See the
section on wind turbines in the landscape).
地形美学的考虑,有时决定了小风机的使用。而且,大风机通常转动速度较小,
也就是一个大风机确实不能像多个快速转动的小风机一样具有吸引力。(见地貌
中的风机一节)
Turbine Safety 风机的安全
Wind Turbine Safety 风力发电机的安全The components of a wind turbine are
designed to last 20 years. This means that
they will have to endure more than 120,000
operating hours, often under stormy
weather conditions.
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风力发电机的部件是在 20年前设计的。这也就意味着它们在暴风雨
天气下已经运行了 120,000多个小时。If you compare with an ordinary automobile engine, it usually only operates
only some 5,000 hours during its lifetime. Large wind turbines are equipped
with a number of safety devices to ensure safe operation during their lifetime.
如果与一般的汽车发动机相比,通常在寿命期内只运行大约 5,000小时。大风机
安装了许多的安全装置以保证寿命期内的运行安全。Sensors 传感器One of the classical, and most simple safety devices in a wind turbine is the
vibration sensor in the image above, which was first installed in the Gedser
wind turbine. It simply consists of a ball resting on a ring. The ball is
connected to a switch through a chain. If the turbine starts shaking, the ball
will fall off the ring and switch the turbine off.
在风机上一个经典的最简单的安全装置是震动传感器,如上图所示,这是第一
个安全装置,安装在Gedser 风力发电机 上。它简单的由一个环上静止的球组成
这个球通过一条链连接在一个开关上。如果风机开始震动,这个球就会从环上落
下,发电机的开关就会断开。There are many other sensors in the nacelle, e.g. electronic thermometers
which check the oil temperature in the gearbox and the temperature of the
generator.
Photograph Soren Krohn © 1998 DWIA
Soren Krohn拍摄
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在机舱中还有许多其他传感器,例如:电子温度计,可以检查齿轮箱的油温和
发电机的温度。Rotor Blades 转轮叶片Safety regulations for wind turbines vary between countries. Denmark is the
only country in which the law requires that all new rotor blades are tested both
statically, i.e. applying weights to bend the blade, and dynamically, i.e. testing
the blade's ability to withstand fatigue from repeated bending more than five
million times. You may read more about this on the page on Testing Wind
Turbine Rotor Blades.
每个国家的风机安全守则不同。只有丹麦一个国家的法律要求所有的新的转轮叶
片都经过静态检测,例如施加重量使叶片弯曲,和动态检测,例如测试叶片能
够承受 5 百万次以上的重复疲劳弯曲。在风机转轮叶片检测一节中你可以阅读到
更多这方面内容。Overspeed Protection 超速保护It is essential that wind turbines stop automatically in case of malfunction of a
critical component. E.g. if the generator overheats or is disconnected from the
electrical grid it will stop braking the rotation of the rotor, and the rotor will start
accelerating rapidly within a matter of seconds.
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如果一个关键部件故障,风机就会自动停止,例如如果发电机过热或者与电网
连接断开,就会对转轮旋转制动使发电机停止,转轮就会在几秒之内迅速开始
加速。In such a case it is essential to have an overspeed protection system. Danish
wind turbines are requited by law to have two independent fail safe brake
mechanisms to stop the turbine.
在这种情况下,有一个超速保护系统是很重要的。丹麦法律要求风力
发电机有两个独立的事故安全制动装置来停止风机。Aerodynamic Braking System: Tip Brakes 空气动力制动系统:叶尖刹车The primary braking system for most modern wind turbines is the
aerodynamic braking system, which essentially consists in turning
the rotor blades about 90 degrees along their longitudinal axis (in the
case of a pitch controlled turbine or an active stall controlled turbine
), or in turning the rotor blade tips 90 degrees (in the case of a stall
controlled turbine ).
现代风力发电机的主要制动系统是空气动力学制动装置系统,主要在
使转轮叶片沿着纵轴方向转动 90度(在一个变桨控制风机或一个主动
失速控制风机的情况下),或者转轮叶片尖端转动 90度(在失速控制风机的情
况下)
@1998 D
WTM
A
Click to Deactivate Tip Brake点击顶部刹车制动
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These systems are usually spring operated, in order to work even in case of
electrical power failure, and they are automatically activated if the hydraulic
system in the turbine loses pressure. The hydraulic system in the turbine is
used turn the blades or blade tips back in place once the dangerous situation
is over.
这些系统通常靠弹簧运行,在电源断电的情况下也会工作,还有风机液压系统
失压时他们会自动激活。风机中的液压系统用于一旦危险情况结束后叶片或叶尖
会复原。Experience has proved that aerodynamic braking systems are extremely safe.
实践证明空气动力学制动装置系统是非常安全的。They will stop the turbine in a matter of a couple of rotations, at the most. In
addition, they offer a very gentle way of braking the turbine without any major
stress, tear and wear on the tower and the machinery.
他们最多以几次旋转停止风机。另外,他们可以提供温和停机,不给塔架和机器
上施加任何应力、撕裂和磨损。The normal way of stopping a modern turbine (for any reason) is therefore to
use the aerodynamic braking system.
使现代发电机(不论任何原因)停下来的正常方法就是使用空气动力制动系统。Mechanical Braking System 机械制动系统
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The mechanical brake is used as a backup system for the aerodynamic
braking system, and as a parking brake, once the
turbine is stopped in the case of a stall controlled
turbine.
机械制动系统是为空气动力制动系统备份的,一旦风
机在失速控制下停止,机械制动是作为停车制动的。Pitch controlled turbines rarely need to activate the mechanical brake (except
for maintenance work), as the rotor cannot move very much once the rotor
blades are pitched 90 degrees.
变桨控制风机很少需要主动的机械制动(除了维修工作),因为当转轮叶片变
桨 90度时转轮不能够大量移动。
Labour safety 职业安全
Wind Turbine Occupational Safety 风力发电机职业安全Towers 塔架Large, modern wind turbines normally use conical tubular steel towers. The
primary advantage of this tower over a lattice tower is that it makes it safer
and far more comfortable for service personnel to access the wind turbine for
repair and maintenance. The disadvantage is cost.
现代的大风机常常使用圆锥管状铁制塔架。这种塔架相对于桁架的优点是更安全
并且使维护人员更容易进入塔架进行修理和维护。缺点就是成本。
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Occupational Safety 职业安全The primary danger in working with wind turbines is the
height above ground during installation work and when
doing maintenance work.
主要的危险是在安装和维修工作时工作的风机高度远离
地面。New Danish wind turbines are required to have fall protection devices, i.e. the
person climbing the turbine has to wear a parachutist-like set of straps.
丹麦的新的风机都要求有安全下降装置,例如,爬上风机的人员要求穿一套像
降落伞一样的背带。The straps are connected with a steel wire to an anchoring system that
follows the person while climbing or descending the turbine.
背带通过钢丝连接在固定的铰链系统上,这样工作人员可以顺着向上爬或下降。The wire system has to include a shock absorber, so that persons are
reasonably safe in case of a fall.
金属丝系统必须包括一个减震器,这样工作人员一旦落下可以相当安全。A Danish tradition (which has later been taken up by
other manufacturers), is to place the access ladders
at a certain distance from the wall. This enables
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service personnel to climb the tower while being able to rest the shoulders
against the inside wall of the tower.
丹麦的传统(这后来被其他厂商采纳),是将入口梯子放置在离墙壁有一定距
离的地方。这样就使服务人员爬上塔架的同时,又可将肩膀靠
在塔架内壁上休息。In this image you see the editor of our Spanish web site verifying that this is
actually a very practical solution.
在这个图片中你可以看到我们西班牙的网站编辑证实了这确实是一个非常实用
的方法。Protection from the machinery, fire protection and electrical insulation
protection is governed by a number of national and international standards.
对机器、消防、电绝缘的保护是由许多国家和国际标准来管理的。During servicing it is essential that the machinery can be stopped completely.
In addition to a mechanical brake, the rotor can be locked in place with a pin,
to prevent any movement of the mechanical parts whatsoever.
在服务过程中机器能够完全停止是很重要的。除机械制动外,转轮可以用销锁住
以防止机器部件的任何移动。
Photograph Soren Krohn © 1999 DWIA
Soren Krohn拍摄
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Generators 发电机
Generators 发电机
Wind Turbine Generators 风力发电机 You can see the internal cooling fan moving inside this generator. It is mounted at the end of the rotor, which is hidden inside the shining magnetic steel cylinder, called the stator. The radiator-like surface cools the generator. It is hard to see the details on a real life generator like the one to the right. Therefore, we'll take it apart and make some simplified models on the next pages
可以看到内部的冷却风扇在发电机里
转动。固定在转轮末端,隐藏在发光的磁钢筒内的,称为定子。像散热片一样的
表面可以冷却发电机。实际中的发电机很难像右侧图中所示那样看到细节。因此
我们将把它拆开,在下文中构造一些简化模型。The wind turbine generator converts mechanical energy to electrical energy.
Wind turbine generators are a bit unusual, compared to other generating units
you ordinarily find attached to the electrical grid. One reason is that the
generator has to work with a power source (the wind turbine rotor) which
supplies very fluctuating mechanical power (torque).
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风力发电机把机械能转化为电能。和你通常所能发现的接入电网的其他发电
单元比较,风力发电机有一点与众不同。一个原因就是发电机必须与一个动力源
(风力涡轮机转轮)一起工作,这个动力源提供波动较大的机械功率(转矩)。These pages assumes that you are familiar with the basics of electricity,
electromagnetism, and in particular alternating current. If any of the
expressions volt (V), phase, three phase, frequency, or Hertz (Hz) sound
strange to you, you should take a look at the Reference Manual on Electricity ,
and read about alternating current , three phase alternating current ,
electromagnetism , and induction , before you proceed with the following
pages.
这些页面中,假设你熟悉电力、电磁学,特别是交流电。如果电压(V)、相、
三相、频率、或赫兹(Hz)中的任何一个表达对你来说是陌生的,那么在你继续以
下页面之前,应该看看参考手册中有关电力的部分,阅读关于交流电、三相交流
电、电磁学和电磁感应的部分。Generating Voltage (tension) 发电电压On large wind turbines (above 100-150 kW) the voltage (tension) generated
by the turbine is usually 690 V three-phase alternating current (AC). The
current is subsequently sent through a transformer next to the wind turbine (or
inside the tower) to raise the voltage to somewhere between 10,000 and
30,000 volts, depending on the standard in the local electrical grid.
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在大型风力机(100-150 kW以上)上,发电产生的电压通常是 690V三相交
流电。电流随后通过紧挨着风力机的变压器(或者在塔架内)发送,变压器把电压
提升到 10,000V和 30,000V之间的某个水平,这取决于当地的电网标准。Large manufacturers will supply both 50 Hz wind turbine models (for the
electrical grids in most of the world) and 60 Hz models (for the electrical grid
in America).
大型制造商既会提供 50Hz的风力机模型(对于世界大部分地方的电网),也
会提供 60Hz的模型(对于美国电网)。Cooling System冷却系统 Generators need cooling while they work. On most turbines this is
accomplished by encapsulating the generator in a duct, using a large fan for
air cooling, but a few manufacturers use water cooled generators. Water
cooled generators may be built more compactly, which also gives some
electrical efficiency advantages, but they require a radiator in the nacelle to
get rid of the heat from the liquid cooling system.
发电机工作时需要冷却。大部分风力机中,是通过把发电机装入管道、用大
风扇进行空气冷却来实现的,也有一小部分制造商使用水冷发电机。水冷发电机
的构造更紧凑,具有电效率更高的优势,但是需要在机舱中增加散热器,把液
体冷却系统中的热量散发掉。
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Starting and Stopping the Generator 启动和停止发电机If you connected (or disconnected) a large wind turbine generator to the grid
by flicking an ordinary switch, you would be quite likely to damage both the
generator, the gearbox and the current in the grid in the neighbourhood.
如果你通过轻拉普通开关,使大型风力发电机与电网连接(或断开),将极
有可能既损害发电机、齿轮箱,也破坏电网临近处的电流。
You will learn how turbine designers deal with this challenge in the page on
Power Quality Issues, later.
在后续关于电能质量问题的页面中,你将会学到风力机设计者如何应对这
个挑战。Design Choices in Generators and Grid Connection 发电机和电网连接的设计选择 Wind turbines may be designed with either synchronous or asynchronous
generators, and with various forms of direct or indirect grid connection of the
generator.
风力机可能设计成具有同步或异步发电机,发电机可能具有直接或间接接
入电网的不同形式。Direct grid connection mean that the generator is connected directly to the
(usually 3-phase) alternating current grid.
直接接入电网意味着发电机直接与交流电网(通常 3相)连接。
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Indirect grid connection means that the current from the turbine passes
through a series of electric devices which adjust the current to match that of
the grid. With an asynchronous generator this occurs automatically.
间接接入电网意味着来自风力机的电能,通过一系列电气装置调节成与电
网匹配的电能。使用异步发电机时,这会自动发生。
Synchronous machines 同步机
Synchronous Generators同步发电机 3-Phase Generator (or Motor) Principles 三相发电机(或电动机)原理All 3-phase generators (or motors) use a
rotating magnetic field.
所有 3相发电机(或电动机)使用旋转磁场。In the picture to the left we have installed
three electromagnets around a circle. Each
of the three magnets is connected to its own phase in the three phase
electrical grid.
在右侧图中,我们在线圈附近安装了三个电磁体,三个磁体中的每一个都
与自身在三相电网中对应的相连接。As you can see, each of the three electromagnets alternate between
producing a South pole and a North pole towards the centre. The letters are
shown in black when the magnetism is strong, and in light grey when the
magnetism is weak. The fluctuation in magnetism corresponds exactly to the
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fluctuation in voltage of each phase. When one phase is at its peak, the other
two have the current running in the opposite direction, at half the voltage.
Since the timing of current in the three magnets is one third of a cycle apart,
the magnetic field will make one complete revolution per cycle.
可以看到,三个电磁体中的每一个都在产生朝向中心的一个 S极和一个 N
极之间交替。当磁性强时,字母以黑色显示;当磁性弱时,以浅灰色显示。磁性
的波动,可以确切地对应每一相电压的波动。当一相在其峰值时,另外两相具有
相反方向的电流,和一半的电压。由于三个磁体中的电流在时间上相隔三分之一
周期,因此磁场会在一个周期内完成一次完整的旋转。Synchronous Motor Operation 同步电机运行The compass needle (with the North pole painted red) will follow the magnetic
field exactly, and make one revolution per cycle. With a 50 Hz grid, the needle
will make 50 revolutions per second, i.e. 50 times 60 = 3000 rpm (revolutions
per minute).
罗盘针(N极红色)会精确地跟随磁场,每个周期旋转一周。对于 50Hz电网,
指针每秒会旋转 50 周,即,50 乘以 60=3000rpm(每分钟旋转数)。In the picture above, we have in fact managed to build what is called a 2-pole
permanent magnet synchronous motor. The reason why it is called a
synchronous motor, is that the magnet in the centre will rotate at a constant
speed which is synchronous with (running exactly like the cycle in) the rotation
of the magnetic field.
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在上面图中,我们实际上构建了一个所谓 2极永磁同步电机。为什么叫做同
步电机的原因,是由于中间的磁体将会以恒定的转速旋转,和磁场的旋转同步
(运行同样的圈数)。The reason why it is called a 2-pole motor is that it has one North and one
South pole. It may look like three poles to you, but in fact the compass needle
feels the pull from the sum of the magnetic fields around its own magnetic
field. So, if the magnet at the top is a strong South pole, the two magnets at
the bottom will add up to a strong North pole.
称为 2极电机的原因是它有一个N极和一个 S极。可能对你来说看上去是 3
个极,但实际上罗盘针受到自身周围总的磁场吸收力的作用。如果顶部磁体是个
强的 S极,两个底部磁体就合成为一个强的N极。The reason why it is called a permanent magnet motor is that the compass
needle in the centre is a permanent magnet, not an electromagnet. (You could
make a real motor by replacing the compass needle by a powerful permanent
magnet, or an electromagnet which maintains its magnetism through a coil
(wound around an iron core) which is fed with direct current).
称为永磁电机的原因是中间的罗盘针是永磁体,不是电磁体。(你可以做一
个实际电机,把罗盘针用强的永磁体代替,或者电磁体通过流有直流电的线圈
(铁芯绕线)维持其磁性)。
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The setup with the three electromagnets is called the stator in the motor,
because this part of the motor remains static (in the same place). The
compass needle in the centre is called the rotor, obviously because it rotates.
电机中具有三个电磁体的装置称为定子,因为这部分的电机保持静止(在同
样的位置)。中间的罗盘针称为转轮,明显由于其在旋转。Synchronous Generator Operation 同步发电机运行If you start forcing the magnet around (instead of letting the current from the
grid move it), you will discover that it works like a generator, sending
alternating current back into the grid. (You should have a more powerful
magnet to produce much electricity). The more force (torque) you apply, the
more electricity you generate, but the generator will still run at the same
speed dictated by the frequency of the electrical grid.
如果你开始施外力于磁体周围(而不是让电能从电网流入),你会发现它像
一个发电机一样工作,发送交流电至电网。(你可以用作用更大的磁体产生更多
的电能)。施加的外力(转矩)越多,产生的电能也越多,但是发电机会依旧运行在
电网频率规定的同样的转速。You may disconnect the generator completely from the grid, and start your
own private 3-phase electricity grid, hooking your lamps up to the three coils
around the electromagnets. (Remember the principle of magnetic / electrical
induction from the reference manual section of this web site). If you
disconnect the generator from the main grid, however, you will have to crank it
at a constant rotational speed in order to produce alternating current with a
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constant frequency. Consequently, with this type of generator you will
normally want to use an indirect grid connection of the generator.
你可以完全断开发电机与电网的连接,开启你自己个人的三相电网,把灯
泡挂接到电磁体附近的三个线圈上。(记得这个网站参考手册中磁 / 电感 应原理部
分)。如果断开发电机与主电网的连接,必须以恒定的转速转动电机,来产生具
有恒定频率的交流电。结果是,使用这种类型的发电机,通常需要把发电机间接
接入电网。In practice, permanent magnet synchronous generators are not used very
much. There are several reasons for this. One reason is that permanent
magnets tend to become demagnetised by working in the powerful magnetic
fields inside a generator. Another reason is that powerful magnets (made of
rare earth metals, e.g. Neodynium) are quite expensive, even if prices have
dropped lately.
实际中,永磁同步发电机使用不是很多。对此,有几个原因。一个原因是永
磁体在发电机内强磁场环境中工作,会趋向失磁。另一个原因是,磁性强的磁体
(由稀土金属制成,例如钕)非常昂贵,即使近来价格已经在下降。Wind Turbines With Synchronous Generators 使用同步发电机的风力机Wind turbines which use synchronous generators normally use
electromagnets in the rotor which are fed by direct current from the electrical
grid. Since the grid supplies alternating current, they first have to convert
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alternating current to direct current before sending it into the coil windings
around the electromagnets in the rotor.
使用同步发电机的风力机通常在转轮中使用电磁体,转轮通过电网由直流
电供电。因为电网提供交流电,在输送至转轮内电磁体附近的线圈绕组前,首先
必须把交流电转换为直流电。The rotor electromagnets are connected to the current by using brushes and
slip rings on the axle (shaft) of the generator.
通过发电机轴上的电刷和滑环,转轮电磁体与输入的电流连接。
No. of poles 极对数
Changing Generator Rotational Speed 改变发电机旋转速度A Four Pole Generator 4 极发电机
The speed of a generator (or motor) which is
directly connected to a three-phase grid is
constant, and dictated by the frequency of the
grid, as we learned on the previous page.
直接与三相电网连接的发电机(电动机)转速
是常数,由电网频率决定,如前面页面所学。If you double the number of magnets in the stator , however, you can ensure
that the magnetic field rotates at half the speed.
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如果使定子中的磁体数量加倍,可以保证磁场以一半的转速旋转。In the picture to the left, you see how the magnetic field now moves clockwise
for half a revolution before it reaches the same magnetic pole as before. We
have simply connected the six magnets to the three phases in a clockwise
order.
在左边图中,在达到前面的同样的磁极之前,可以看到磁场现在顺时针移
动半圈。以顺时针的顺序,我们简单地把 6个磁体连接成三相。This generator (or motor) has four poles at all times, two South and two North.
Since a four pole generator will only take half a revolution per cycle, it will
obviously make 25 revolutions per second on a 50 Hz grid, or 1500
revolutions per minute (rpm).
这个发电机(电动机)在所有时间都有 4个极,两个 S极和两个N极。因为 4
极发电机每个周期仅旋转半圈,显然对于 50Hz电网每秒将旋转 25圈,或者
1500圈每分钟(rpm)。When we double the number of poles in the stator of a synchronous generator
we will have to double the number of magnets in the rotor, as you see on the
picture. Otherwise the poles will not match. (We could use to two bent
"horseshoe" magnets in this case).
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当我们使同步发电机定子中的极数加倍时,还必须使转轮中的磁体数加倍,
可以从图中看到。否则极数会不匹配。(这种状况我们可以使用两个弯曲的“马蹄
形”磁体)。Other Numbers of Poles 其他极数Obviously, we could repeat what we just did, and introduce another pair of
poles, by adding 3 more electromagnets to the stator. With 9 magnets we get
a 6 pole machine, which will run at 1000 rpm on a 50 Hz grid. The general
result is the following:
显然,我们可以重复刚刚做过的,引入另一对极,在定子中再增加 3个电
磁体。使用 9个磁体,得到 6极电机,将会在 50Hz电网中运行在 1000rpm。通
用的结果如下:Synchronous Generator Speeds (rpm) 发电机同步速(rpm)
Pole number 极数 50 Hz 60 Hz 2 3000 3600 4 1500 1800 6 1000 1200 8 750 900
10 600 720 12 500 600
The term "synchronous generator speed" thus refers to the speed of the
generator when it is running synchronously with the grid frequency. It applies
to all sorts of generators, however: In the case of asynchronous (induction)
generators it is equivalent to the idle speed of the generator.
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术语“发电机同步速”是指发电机与电网频率同步运行时的转速。这适用于
所有种类的发电机,但是:在异步(感应)发电机的情况下,其等效于发电机的
空转转速。High or Low Speed Generators? 高速或低速发电机?Most wind turbines use generators with four or six poles. The reasons for
using these relatively high-speed generators are savings on size and cost.
大部分风力机使用 4极或 6极发电机,使用这些相对高转速发电机的原因
是节省尺寸和成本。The maximum force (torque) a generator can handle depends on the rotor
volume. For a given power output you then have the choice between a slow-
moving, large (expensive) generator, or a high-speed (cheaper) smaller
generator.
发电机能够处理的最大外力(转矩)取决于转轮体积。对于一个给定的功率输
出,可以在运动较慢、大的(昂贵)发电机和高速(更便宜)、体积更小的发电机之间
选择。
Asynchronous machines 异步机
Asynchronous (Induction) Generators 异步 (感应)发电机
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The picture to the right illustrates the basic principles in the asynchronous generator, much as we saw it presented on the previous pages. In reality, only the rotor part looks different, as you will see on the this page
右侧图中说明了异步发电机的基本原理,和前面页面中提及的非常相似。实
际上,只有转轮部分看起来不一样,就如本页面中看到的。Note: Before reading this page, you should have completed the previous three
pages on Wind Turbine Generators. Most wind turbines in the world use a so-
called three phase asynchronous (cage wound) generator, also called an
induction generator to generate alternating current. This type of generator is
not widely used outside the wind turbine industry, and in small hydropower
units, but the world has a lot of experience in dealing with it anyway:
注意:阅读本节之前,你应该已经完成之前关于风力发电机的前面 3节。世界上
大部分风力机使用一种所谓的三相异步(鼠笼绕线)发电机,也称为感应发电机,
来产生交流电。这种类型的发电机在风力机产业以外没有广泛使用,多应用于小
型水电单元,但无论如何世界上有很多这方面的应对经验。The curious thing about this type of generator is that it was really originally
designed as an electric motor. In fact, one third of the world's electricity
consumption is used for running induction motors driving machinery in
factories, pumps, fans, compressors, elevators, and other applications where
you need to convert electrical energy to mechanical energy.
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这种类型的发电机值得好奇的事情是,它实际中最初是作为电动机来设计的。事
实上,世界上三分之一的电力消耗是用于运行感应电机来驱动工厂的机器,泵、
风扇、压缩机、升降机和其他应用,凡是需要把电能转换为机械能的地方。One reason for choosing this type of generator is that it is very reliable, and
tends to be comparatively inexpensive. The generator also has some
mechanical properties which are useful for wind turbines. (Generator slip, and
a certain overload capability).
选择这种类型发电机的一个原因是其非常可靠,趋向于相对便宜。而且这类发电
机具有一些机械特性,对风力机是有利的。(发电机滑差,一定的过载容量)
The Cage Rotor笼型转轮The key component of the asynchronous generator is the cage rotor. (It used to be called a squirrel cage rotor but after it became politically incorrect to exercise your domestic rodents in a treadmill, we only have this less captivating name)
异步发电机的关键部件是笼型转轮。(过去被叫做鼠笼转轮,在踏车上训练啮齿
类动物变得政治上不正确之后,我们只能采用这样一个没那么有魅力的名字)。It is the rotor that makes the asynchronous generator different from the
synchronous generator. The rotor consists of a number of copper or
aluminium bars which are connected electrically by aluminium end rings.
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是转轮让异步发电机区别于同步发电机。转轮有许多铜条或铝棒构成,铜条或铝
棒通过末端的铝环在电气上连接。In the picture at the top of the page you see how the rotor is provided with an
"iron" core, using a stack of thin insulated steel laminations, with holes
punched for the conducting aluminium bars. The rotor is placed in the middle
of the stator, which in this case, once again, is a 4-pole stator which is directly
connected to the three phases of the electrical grid.
本页上方的图中,可以看到“铁”芯被提供给转轮,使用薄的绝缘钢迭片堆叠
而成,带有为安装导电的铝棒冲压的孔洞。转轮放置在定子的中间,在这种状况
再一次,是 4极定子直接与电网的三相连接。Motor Operation 电机运行When the current is connected, the machine will start turning like a motor at a
speed which is just slightly below the synchronous speed of the rotating
magnetic field from the stator. Now, what is happening?
连接上电流时,电机将会开始旋转,像一个电动机,运行在略微低于定子旋转
磁场同步速的转速上。If we look at the rotor bars from above (in the picture to the right) we have a
magnetic field which moves relative to the rotor. This induces a very strong
current in the rotor bars which offer very little resistance to the current, since
they are short circuited by the end rings.
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如果我们从上面观察转轮的导条(在右侧图中),会有相对转轮运动的磁场。这会
在转轮导条中感应非常强的电流,导条的电阻对于电流来说非常小,因为它们
通过末端的环在电路上短接。The rotor then develops its own magnetic poles, which in turn become
dragged along by the electromagnetic force from the rotating magnetic field in
the stator.
然后转轮产生自身的磁极,随后被定子旋转磁场沿着电磁力的方向牵引。Generator Operation 发电机运行Now, what happens if we manually crank this rotor around at exactly the
synchronous speed of the generator, e.g. 1500 rpm (revolutions per minute),
as we saw for the 4-pole synchronous generator on the previous page? The
answer is: Nothing. Since the magnetic field rotates at exactly the same
speed as the rotor, we see no induction phenomena in the rotor, and it will not
interact with the stator.
现在,如果我们手工转动转轮,基本约在发电机同步速附近,例如 1500rpm(转
数每分钟),如前一页我们看到的 4极同步发电机一样,那么会发生什么?答案
是:什么也没有。因为磁场旋转速度与转轮一样,我们看不到转轮的感应现象,
它将与定子没有相互作用。But what if we increase speed above 1500 rpm? In that case the rotor moves
faster than the rotating magnetic field from the stator, which means that once
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again the stator induces a strong current in the rotor. The harder you crank
the rotor, the more power will be transferred as an electromagnetic force to
the stator, and in turn converted to electricity which is fed into the electrical
grid.
但是如果我们增加转速超过 1500rpm 呢?在那种状况下转轮运动比定子旋转磁
场要快,这意味着定子会再一次在转轮中感应强的电流。转动转轮越快,转移的
功率就越多,由于定子电磁力的作用,随后转换为电能馈入电网。Generator Slip 发电机滑差The speed of the asynchronous generator will vary with the turning force
(moment, or torque) applied to it. In practice, the difference between the
rotational speed at peak power and at idle is very small, about 1 per cent. This
difference in per cent of the synchronous speed, is called the generator's slip.
Thus a 4-pole generator will run idle at 1500 rpm if it is attached to a grid with
a 50 Hz current. If the generator is producing at its maximum power, it will be
running at 1515 rpm.
异步发电机的转速会随着所施加的旋转力(力矩,或转矩)而变化。实际上,峰值
功率和空载时的旋转速度差别很小,约为 1%。这种以同步速百分比表示的差别
称为发电机滑差。因此 4极发电机如果接在 50Hz电网中,空转时会运行在
1500rpm。如果发电机产生其峰值功率,将会运行在 1515rpm。It is a very useful mechanical property that the generator will increase or
decrease its speed slightly if the torque varies. This means that there will be
less tear and wear on the gearbox. (Lower peak torque). This is one of the
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most important reasons for using an asynchronous generator rather than a
synchronous generator on a wind turbine which is directly connected to the
electrical grid.
这是一个非常有用的机械特性,如果转矩变化发电机转速会轻微增加或降低。这
意味着齿轮箱上会有更少的磨损。(更低的峰值转矩)。这是最重要的原因之一,
在直接接入电网的风力机上使用异步发电机而不是同步发电机。Automatic Pole Adjustment of the Rotor 转轮自动极数调整Did you notice that we did not specify the number of poles in the stator when
we described the rotor? The clever thing about the cage rotor is that it adapts
itself to the number of poles in the stator automatically. The same rotor can
therefore be used with a wide variety of pole numbers.
当描述转轮时,你是否注意到我们没有详细说明定子的极数?关于笼型转轮非
常聪明的事情是,它使自身自动地适应定子的极数。同样的转轮从而可以用于宽
范围的极数。Grid Connection Required 并网的需要On the page about the permanent magnet synchronous generator we showed
that it could run as a generator without connection to the public grid.
在关于永磁同步发电机的页面中,我们指出其可以作为发电机运行而不用接入
公共电网。
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An asynchronous generator is different, because it requires the stator to be
magnetised from the grid before it works.
异步发电机是不同的,因为它在工作前需要定子从电网提供励磁。You can run an asynchronous generator in a stand alone system, however, if
it is provided with capacitors which supply the necessary magnetisation
current. It also requires that there be some remanence in the rotor iron, i.e.
some leftover magnetism when you start the turbine. Otherwise you will need
a battery and power electronics, or a small diesel generator to start the
system).
可以在独立系统中运行异步发电机,可是需要提供电容,从而供给足够的励磁
电流。也需要在转轮铁心中存在一定的剩磁,例如,当启动风力机时一些残余的
磁性。否则需要蓄电池和电力电子装置,或者小的柴油发电机来启动系统。
Changing no. of poles 改变极数
Changing the Number of Generator Poles 改变发电机极数Very Like a Whale In reality, the
stator of a generator consists of a
very large number of
electromagnets.
事实上非常像一头鲸鱼,发电机
定子由数量很大的电磁体构成。
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You may be thinking that a stator with twice as many magnets would be twice
as expensive, but that is not really the case. Generators (and motors) are
usually made with a very large number of stator magnets anyway, as you see
in the picture. (We have not yet added the stator coil windings on the iron).
你可能想象定子磁体数加倍,价格也会加倍,但实际上这种情况不是。发电机
(和电动机)通常都具有大量的定子磁体,如图中所见。(我们还没有在铁芯上增加
定子线圈绕组)。The reason for this stator arrangement is that we wish to minimise the air gap
between the rotor and the stator. At the the same time we need to provide
cooling of the magnets. The stator iron in reality consists of a large number of
thin (0.5 mm) insulated steel sheets which are stacked to form the stator iron.
This layering is done to prevent current eddies in the stator iron from
decreasing the efficiency of the generator.
这种定子布局的原因是,我们希望将转轮和定子之间的气隙降到最小。同时,我
们需要提供磁体的散热。定子实际上有很多薄的(0.5mm)绝缘钢片堆叠形成
定子铁芯。采用压条法,防止定子涡流降低发电机效率。The problem of providing more generator poles on an asynchronous cage
wound generator then really boils down to connecting the neighbouring
magnets differently: Either we take a bunch of magnets at a time, connecting
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them to the same phase as we move around the stator, or else we change to
the next phase every time we get to the next magnet.
在异步笼型绕线发电机上提供更多极数的问题可以实在地归结为连接相邻磁体
的不同:要么在定子周围移动时一次拿一束磁体,连接到同一相,要么每次我
们到达下一个磁体时换到下一相。Two Speed, Pole Changing Generators 双速,换极发电机Some manufacturers fit their turbines with two generators, a small one for
periods of low winds, and a large one for periods of high winds.
一些制造商在其风力机里安装两个发电机,一个小的用于低风速时段,一个大
的用于高风速时段。A more common design on newer machines is pole changing generators, i.e.
generators which (depending on how their stator magnets are connected)
may run with a different number of poles, and thus a different rotational
speed.
新电机更常用的设计是换极发电机,即,发电机(取决于其定子磁体如何连接)
可以运行在不同的极数,从而有不同的旋转速度。Some electrical generators are custom built as two-in-one, i.e. they are able to
run as e.g. either 400 kW or 2000 kW generators, and at two different speeds.
This design has become ever more widespread throughout the industry.
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一些发电机按照一个中包含两个来定制,即可以作为例如 400kW或 2000kW的
发电机运行,处在两个不同的转速。这种设计已经在工业界变得非常普遍。Whether it is worthwhile to use a double generator or a higher number of
poles for low winds depends on the local wind speed distribution , and the
extra cost of the pole changing generator compared to the price the turbine
owner gets for the electricity. (You should keep in mind that the energy
content of low winds is very small).
使用双发电机或对于低风速更多的极数是否值得,取决于当地的风速分布情况,
以及换极发电机额外的成本相对于风力机所有者所获得电能的价格。 (你应该记
着低风速时的能量非常小)。A good reason for having a dual generator system, however, is that you may
run your turbine at a lower rotational speed at low wind speeds. This is both
more efficient (aerodynamically), and it means less noise from the rotor
blades (which is usually only a problem at low wind speeds).
然而,使用双发电机系统的一个很好的理由是,可以使风力机在低风速时运行
在更低的转速。这既会有更好的效率(空气动力学上),也意味着转轮叶片更低的
噪声(通常只在低风速时是问题)。Incidentally, you may have a few pole changing motors in your house without
even knowing it: Washing machines which can also spin dry clothes usually
have pole changing motors which are able to run at low speed for washing
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and at high speed for spinning. Similarly, exhaust fans in your kitchen may be
built for two or three different speeds. (In the latter case with a variable speed
fan, you can use what you have learned about the energy in the wind: If you
want to move twice as much air out of your house per minute using the same
fan, it will cost you eight times as much electricity).
顺便提及,你可能在自己的房间里有一些换极电机,但是自己根本不知道:洗
衣机还可以旋转甩干衣服,通常具有换极电机,能够在洗涤时运行在低转速,
甩干旋转时运行在高转速。相似地,厨房的排气扇也可能有两个或者三个不同的
转速。(在后面使用变速风扇的情况,可以使用学到的关于风能的知识:如果你
使用同样的风扇在一分钟内把房间的空气排掉 2倍,你将花费 8倍的电力)。
Variable slip 可变滑差
Variable Slip Generators for Wind Turbines 风力机中的变滑差发电机Manufacturers of electric motors have for many years been faced with the
problem that their motors can only run at certain almost fixed speeds
determined by the number of poles in the motor.
电动机制造商很多年面临着一个问题,他们的电机仅能运行在由电机极数决定
的基本固定的转速上。As we learned on the previous page, the motor (or generator) slip in an
asynchronous (induction) machine is usually very small for reasons of
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efficiency, so the rotational speed will vary with around 1 per cent between
idle and full load.
如同我们在前一页所学到的,异步(感应)电机中的电动机(或发电机)滑差由于效
率原因,通常非常小,因此旋转速度在空载和满载之间将会有 1%左右的变化。The slip, however is a function of the (DC) resistance (measured in ohms) in
the rotor windings of the generator. The higher resistance, the higher the slip.
so one way of varying the slip is to vary the resistance in the rotor. In this way
one may increase generator slip to e.g. 10 per cent.
但是滑差是发电机转轮绕组中(直流)电阻(以欧姆表示)的函数。电阻越高,滑差
越大。因此改变滑差的一种方法是改变转轮电阻。这种方法可能增大发电机滑差
例如到 10%。On motors, this is usually done by having a wound rotor, i.e. a rotor with
copper wire windings which are connected in a star, and connected with
external variable resistors, plus an electronic control system to operate the
resistors. The connection has usually been done with brushes and slip rings,
which is a clear drawback over the elegantly simple technical design of an
cage wound rotor machine. It also introduces parts which wear down in the
generator, and thus the generator requires extra maintenance.
在电动机上,这通常由绕线转轮实现,即转轮带有连接成星形的铜线绕组,与
外部的可变电阻连接,加上电子控制系统来操作电阻。连接通常由电刷和滑环完
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成,这是一个明显的缺点,对于笼型绕线转轮电机的优良简单技术设计来说。这
也引入了发电机中容易磨损的地方,因此发电机需要额外的维护。Opti Slip® 最优滑差An interesting variation of the variable slip induction generator avoids the
problem of introducing slip rings, brushes, external resistors, and
maintenance altogether.
可变滑差感应发电机的一个有趣的变化,避免了引入滑环、电刷、外部电阻和维
护的所有问题。By mounting the external resistors on the rotor itself, and mounting the
electronic control system on the rotor as well, you still have the problem of
how to communicate the amount of slip you need to the rotor. This
communication can be done very elegantly, however, using optical fibre
communications, and sending the signal across to the rotor electronics each
time it passes a stationary optical fibre.
通过把外部电阻固定在转轮自身上,并且把电子控制系统也固定在转轮上,依
旧存在如何把需要的滑差量传递给转轮的问题。但是这种通讯可以完美解决,使
用光纤通讯,当每次其通过一个固定的光纤时,把信号发送至转轮电子装置。Running a Pitch Controlled Turbine at Variable Speed 在可变转速运行变桨控制风力机As mentioned on the next page, there are a number of advantages of being
able to run a wind turbine at variable speed.
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如下一页提到的,能使风力机运行在可变转速有很多优势。One good reason for wanting to be able to run a turbine partially at variable
speed is the fact that pitch control (controlling the torque in order not to
overload the gearbox and generator by pitching the wind turbine blades) is a
mechanical process. This means that the reaction time for the pitch
mechanism becomes a critical factor in turbine design.
需要风力机能够部分地变速运行的一个好的理由,是基于变桨距控制(通过调节
风力机叶片桨距角控制转矩,以免齿轮箱和发电机过载 )是一个机械过程这样的
事实。这意味着变桨距机构的响应时间是风力机设计的一个关键因素。If you have a variable slip generator, however, you may start increasing its
slip once you are close to the rated power of the turbine. The control strategy
applied in a widely used Danish turbine design is to run the generator at half
of its maximum slip when the turbine is operating near the rated power. When
a wind gust occurs, the control mechanism signals to increase generator slip
to allow the rotor to run a bit faster while the pitch mechanism begins to cope
with the situation by pitching the blades more out of the wind. Once the pitch
mechanism has done its work, the slip is decreased again. In case the wind
suddenly drops, the process is applied in reverse.
可是如果有一个可变滑差的发电机,一旦接近风力机的额定功率时,你可以开
始增加它的滑差。丹麦风力机设计中广泛应用的控制策略是,当风力机在接近额
定功率运行时,运行发电机在其最大滑差的一半。当阵风出现时,控制机构信号
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增大发电机滑差,允许转轮运行的更快一点,同时变桨距结构开始处理这种情
况,通过调大叶片桨距角来偏离阵风。一旦变桨距结构完成工作,滑差会再减小
在风力突然减小的状况下,应用相反的过程。Although these concepts may sound simple, it is quite a technical challenge to
ensure that the two power control mechanisms co-operate efficiently.
尽管这些概念听起来可能简单,但保证两个功率控制结构高效协作,完全是一
个技术挑战。Improving Power Quality 提高电能质量You may protest that running a generator at high slip releases more heat from
the generator, which runs less efficiently. That is not a problem in itself,
however, since the only alternative is to waste the excess wind energy by
pitching the rotor blades out of the wind.
你可以提出异议,使发电机运行在高滑差会释放更多的热量,这会降低效率。但
这对电机本身来说不是问题,因为唯一可替代的就是通过调节叶片桨距角偏离
风向,浪费掉多余的风能。One of the real benefits of using the control strategy mentioned here is that
you get a better power quality, since the fluctuations in power output are
"eaten up" or "topped up" by varying the generator slip and storing or
releasing part of the energy as rotational energy in the wind turbine rotor.
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使用这里提到的控制策略的一个实在的好处是获得更好的电能质量,因为功率
输出的波动被“吃掉”或“加满”,通过改变发电机滑差,存储或释放一部分
能量,作为风力机转轮的转动能量。
Indirect grid connection 间接电网连接
Indirect Grid Connection of Wind Turbines风力机的间接电网连接
Generating Alternating Current (AC) at Variable Frequency产生频率可变的交流电(AC)
Most wind turbines run at almost constant speed with direct grid connection.
With indirect grid connection, however, the wind turbine generator runs in its
own, separate mini AC-grid, as illustrated in the graphic. This grid is controlled
electronically (using an inverter), so that the frequency of the alternating
current in the stator of the generator may be varied. In this way it is possible
to run the turbine at variable rotational speed. Thus the turbine will generate
alternating current at exactly the variable frequency applied to the stator.
大部分风力机运行在基本恒定的转速,采用直接电网连接。但是采用间接电网连
接,风力发电机运行在其自身的、独立的小型交流电网中,如图中所示。这种电
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网是电子控制(使用逆变器),因此发电机定子中交流电的频率可以改变。用这种
方式,使风力机运行在可变的旋转速度是可能的。因而风力机将会产生可变频率
的交流电,施加在定子上。The generator may be either a synchronous generator or an asynchronous
generator, and the turbine may have a gearbox, as in the image above, or run
without a gearbox if the generator has many poles, as explained on the next
page.
发电机可能是同步发电机或异步发电机,风力机可能有齿轮箱,如上图所示,
或者无齿轮箱运行,如果发电机有很多极数的话,如下一页所述。Conversion to Direct Current (DC) 转换为直流电(DC)
AC current with a variable frequency cannot be handled by the public
electrical grid. We therefore start by rectifying it, i.e. we convert it into direct
current, DC. The conversion from variable frequency AC to DC can be done
using thyristors or large power transistors.
公共电网不能处理具有可变频率的交流电。因此我们开始通过整流,即将其转换
为直流电(DC)。可变频率的交流(AC)到直流(DC)的转换,通过晶闸管或大功率
晶体管来实现。Conversion to Fixed Frequency AC 转换成固定频率交流电We then convert the (fluctuating) direct current to an alternating current (using
an inverter) with exactly the same frequency as the public electrical grid. This
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conversion to AC in the inverter can also be done using either thyristors or
transistors.
然后把(波动的)直流电转换为交流电(使用逆变器),频率与公共电网完全一致。
在逆变器中转换为交流电(AC)同样可以通过晶闸管或晶体管实现。Thyristors or power transistors are large semiconductor switches that operate
without mechanical parts. The kind of alternating current one gets out of an
inverter looks quite ugly at first sight - nothing like the smooth sinusoidal curve
we learned about when studying alternating current. Instead, we get a series
of sudden jumps in the voltage and current, as you saw in the animation
above.
晶闸管或功率晶体管是大的半导体开关,其运行没有机械部分。从逆变器获取的
交流电第一眼看起来非常难看,一点都不像我们以往学习交流电时平滑的正弦
曲线。相反,我们得到一系列电压和电流中突然的跳变,如同上面动画中看到的Filtering the AC 交流电滤波The rectangular shaped waves can be smoothed out, however, using
appropriate inductances and capacitors, in a so-called AC filter mechanism.
The somewhat jagged appearance of the voltage does not disappear
completely, however, as explained below.
可是,在所谓的交流(AC)滤波器结构中,使用合适的电感和电容,矩形波能够
被平滑。但是,电压有点锯齿形的外观不会完全消失,下面将解释。Advantages of Indirect Grid Connection: Variable Speed 间接电网连接的优势:变速
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The advantage of indirect grid connection is that it is possible to run the wind
turbine at variable speed.
间接电网连接的优势在于可能使风力机变速运行。The primary advantage is that gusts of wind can be allowed to make the rotor
turn faster, thus storing part of the excess energy as rotational energy until the
gust is over. Obviously, this requires an intelligent control strategy, since we
have to be able to differentiate between gusts and higher wind speed in
general. Thus it is possible to reduce the peak torque (reducing wear on the
gearbox and generator), and we may also reduce the fatigue loads on the
tower and rotor blades.
首要的优势是,允许阵风使转轮旋转更快,从而存储多余的部分能量作为转动
能量,直到阵风结束。显然,这需要智能控制策略,因为我们必须能够区分阵风
和一般意义上更高的风速。因此,有可能减小峰值转矩 (减小齿轮箱和发电机的
磨损),也能够减小塔架和转轮叶片的疲劳载荷。The secondary advantage is that with power electronics one may control
reactive power (i.e. the phase shifting of current relative to voltage in the AC
grid), so as to improve the power quality in the electrical grid. This may be
useful, particularly if a turbine is running on a weak electrical grid.
其次的优势是,使用电力电子装置可以控制无功功率 (即,电流相对于交流电网
电压的相位移动),从而提高电网的电能质量。这是有益的,特别是当风力机运
行在弱电网时。229
Theoretically, variable speed may also give a slight advantage in terms of
annual production, since it is possible to run the machine at an optimal
rotational speed, depending on the wind speed. From an economic point of
view that advantage is so small, however, that it is hardly worth mentioning.
理论上,变速还有可能在年产出方面具有微小的优势,因此可能根据风速使风
电机运行在最优旋转速度。然而从经济学视点来看,优势如此小,以至于几乎不
值一提。Disadvantages of Indirect Grid Connection 间接电网连接的劣势The basic disadvantage of indirect grid connection is cost. As we just learned,
the turbine will need a rectifier and two inverters, one to control the stator
current, and another to generate the output current. Presently, it seems that
the cost of power electronics exceeds the gains to be made in building lighter
turbines, but that may change as the cost of power electronics decreases.
Looking at operating statistics from wind turbines using power electronics
(published by the the German ISET Institute), it also seems that availability
rates for these machines tend to be somewhat lower than conventional
machines, due to failures in the power electronics.
间接电网连接的基本劣势是成本。如刚刚所学,风力机需要一个整流器和两个逆
变器,一个控制定子电流,另外的产生输出电流。目前,似乎电力电子的成本要
超过建设小型风力机的收益,但是随着电力电子成本的下降,这可能改变。从使
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用电力电子的风力机的运行统计数字(由德国 ISET 研究所出版)来看,由于电力
电子的失效,这些风机的可利用率趋向于略微低于常规风机。Other disadvantages are the energy lost in the AC-DC-AC conversion
process, and the fact that power electronics may introduce harmonic distortion
of the alternating current in the electrical grid, thus reducing power quality.
The problem of harmonic distortion arises because the filtering process
mentioned above is not perfect, and it may leave some "overtones" (multiples
of the grid frequency) in the output current.
其他的劣势是 AC-DC-AC变换过程中的能量损耗,以及电力电子可能在电网交
流电中引入谐波畸变的事实,从而降低了电能质量。引起谐波畸变的问题,是因
为上面提高的滤波过程不够理想,可能会在输出电流中留下一些“谐波” (电网
频率的倍数)。
Gearboxes 齿轮箱
Gearboxes for Wind Turbines 风力机齿轮箱Why Use a Gearbox? 为什么使用齿轮箱?The power from the rotation of the wind turbine
rotor is transferred to the generator through the
power train, i.e. through the main shaft, the
gearbox and the high speed shaft, as we saw on
the page with the Components of a Wind Turbine.
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来自风力机转轮旋转的功率被传递到发电机,通过功率链,即,通过主轴、齿轮
箱和高速轴,如我们在风力机部件的页面中看到的。But why use a gearbox? Couldn't we just drive the generator directly with the
power from the main shaft?
但是为什么要使用齿轮箱?为什么就不能主轴的功率直接驱动发电机?If we used an ordinary generator, directly connected to a 50 Hz AC (
alternating current ) three phase grid with two, four, or six poles, we would
have to have an extremely high speed turbine with between 1000 and 3000
revolutions per minute (rpm), as we can see in the page on Changing
Generator Rotational Speed. With a 43 metre rotor diameter that would imply
a tip speed of the rotor of far more than twice the speed of sound, so we might
as well forget it.
如果我们使用普通的发电机,具有 2、4或 6极,直接连接到 50Hz AC(交流电)
三相电网,我们必须有非常高速的风力机,转数在每分钟 1000到 3000之间
(rpm),如我们在关于改变发电机旋转速度一节中看到的。具有 43米的转轮直径
则意味着转轮的叶尖速会远超过两倍的声速,所以我们不想这一招。Another possibility is to build a slow-moving AC generator with many poles.
But if you wanted to connect the generator directly to the grid, you would end
up with a 200 pole generator (i.e. 300 magnets) to arrive at a reasonable
rotational speed of 30 rpm.
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另一个可能是构建具有多个极数的运动较慢的交流发电机。但是如果想把发电机
直接连接到电网,可能需要 200极的发电机(即 300个磁体),才能达到 30rpm
的合理旋转速度。Another problem is, that the mass of the rotor of the generator has to be
roughly proportional to the amount of torque (moment, or turning force) it has
to handle. So a directly driven generator will be very heavy (and expensive) in
any case.
另一个问题是,发电机转轮质量必须粗略地与其能够处理的转矩量 (力矩,或旋
转力)成正比。因此,直接驱动发电机在任何状况下都将非常重(和昂贵)。Less Torque, More Speed 低转矩,高转速The practical solution, which is used in the opposite direction in lots of
industrial machinery, and in connection with car engines is to use a gearbox.
With a gearbox you convert between slowly rotating, high torque power which
you get from the wind turbine rotor - and high speed, low torque power, which
you use for the generator.
实际的解决方案,是在相反的变速方向应用于大量工业机械中,并且与汽车发
动机连接中使用齿轮箱。使用齿轮箱,可以在从风力机获取的低速旋转、高转矩
功率转换为发电机的高转速、低转矩功率。
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The gearbox in a wind turbine does not "change gears". It normally has a
single gear ratio between the rotation of the rotor and the generator. For a 600
or 750 kW machine, the gear ratio is typically approximately 1 to 50.
风力机中的齿轮箱不是“变更齿轮”。通常在转轮和发电机的旋转之间有一个单
一的齿轮变比。对于 600或 750kW电机,齿轮比典型约为 1比 50。The picture below shows a 1.5 MW gearbox for a wind turbine. This particular
gearbox is somewhat unusual, since it has flanges for two generators on the
high speed side (to the right). The orange gadgets just below the generator
attachments to the right are the hydraulically operated emergency disc
brakes. In the background you see the lower part of a nacelle for a 1.5 MW
turbine.
下面图中显示了一个 1.5MW风力机的齿轮箱。这个特别的齿轮箱有点与众不同,
因为高速侧(向右的)的两个发电机具有凸缘。略低于发电机附件右边的橙色小配
件是液压操作的紧急刹车盘。在后面,你看到 1.5 MW风力机机舱的较低的部分
Controllers 控制器
The Electronic Wind Turbine Controller 风力机电子控制器The wind turbine controller consists of a number of
computers which continuously monitor the
condition of the wind turbine and collect statistics
on its operation. As the name implies, the controller
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also controls a large number of switches, hydraulic pumps, valves, and
motors within the wind turbine.
风力机控制器由一些计算机构成,持续监测风力机的状态,收集其运行统计数
字。正如名字所表示的,控制器也要控制风力机内部大量的开关、液压泵、阀门
和电机。As wind turbine sizes increase to megawatt machines, it becomes even more
important that they have a high availability rate, i.e. that they function reliably
all the time.
随着风力机容量增大至兆瓦级电机,具有更高的利用率变得更加重要,即,它
们需要在所有时间都可靠运行。Communicating with the Outside World 与外部世界通讯The controller communicates with the owner or operator of the wind turbine
via a communications link, e.g. sending alarms or requests for service over
the telephone or a radio link. It is also possible to call the wind turbine to
collect statistics, and check its present status. In wind parks one of the
turbines will usually be equipped with a PC from which it is possible to control
and collect data from the rest of the wind turbines in the park. This PC can be
called over a telephone line or a radio link.
控制器和风力机所有者或操作者的通讯经由通讯线路,例如,发送报警或请求
服务,通过电话或无线电线路。也有可能呼叫风力机收集统计数字,检查其当前
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状态。在风场,其中一个风力机中往往配备了 PC,可以控制和采集风场中其余
风力机的数据。这个 PC可以通过电话线或无线电来呼叫。Internal Communications 内部通讯There is usually a controller both at the bottom of the tower and
in the nacelle. On recent wind turbine models, the
communication between the controllers is usually done using
fibre optics. The image to the right shows a fibre optics
communications unit. On some recent models, there is a third
controller placed in the hub of the rotor. That unit usually communicates with
the nacelle unit using serial communications through a cable connected with
slip rings and brushes on the main shaft.
通常在塔架底部和机舱里都有一个控制器。在近来的风力机模型中,控制器之间
的通讯常常由光纤完成。右侧的图像显示了一个光纤通讯单元。在一些近来的模
型中,还有第三个控制器放置在转轮轮毂中。这个单元与机舱单元的通讯常常采
用串行通讯,通过电缆与主轴上的滑环和电刷连接。Fail Safe Mechanisms and Redundancy 失效安全机制和冗余Computers and sensors are usually duplicated (redundant) in all safety or
operation sensitive areas of newer, large machines. The controller
continuously compares the readings from measurements throughout the wind
turbine to ensure that both the sensors and the computers themselves are
OK. The picture at the top of the page shows the controller of a megawatt
machine, and has two central computers. (We removed the cover on one of
the two computers to show the electronics).
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计算机和传感器常被复制(冗余)在新的、大型电机的所有安全和运行敏感区域。
控制器持续地比较整个风力机的测量读数,来保证传感器和计算机自身都是好
的。页面上方的图片显示了兆瓦级电机的控制器,具有两个中央计算机。(我们移
开两个计算机中一个的盖子,来显示电子器件)。What is Monitored? 监控什么?It is possible to monitor or set somewhere between 100 and 500 parameter
values in a modern wind turbine. The controller may e.g. check the rotational
speed of the rotor, the generator, its voltage and current. In addition, lightning
strikes and their charge may be registered. Furthermore measurements may
be made of of outside air temperature, temperature in the electronic cabinets,
oil temperature in the gearbox, the temperature of the generator windings, the
temperature in the gearbox bearings, hydraulic pressure, the pitch angle of
each rotor blade (for pitch controlled or active stall controlled machines), the
yaw angle (by counting the number of teeth on yaw wheel), the number of
power cable twists, wind direction, wind speed from the anemometer, the size
and frequency of vibrations in the nacelle and the rotor blades, the thickness
of the brake linings, whether the tower door is open or closed (alarm system).
在现代风力机中,可能要监控或设置 100到 500个之间的某个数量的参数值。
控制器可能检查例如转轮旋转速度、发电机及其电压和电流。另外,雷击及其电
荷也要记录。而且,要测量外部空气温度、电子柜内温度、齿轮箱内的油温、发电
机绕组温度、齿轮箱轴承内温度、水压、每个转轮叶片的桨距角(对于变桨控制或
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主动失速控制风机)、偏航角(通过计数偏航齿轮的齿数)、电力电缆缠绕的圈数、
风向、来自风速计的风速、机舱内和转轮叶片振动的幅度和频率、刹车片的厚度、
塔架门是否打开或关闭(报警系统)。Control Strategies 控制策略Many of the business secrets of the wind turbine manufacturers are to be
found in the way the controller interacts with the wind turbine components.
Improved control strategies are responsible for an important part of the
increase in wind turbine productivity in recent years.
风力机制造商的很多商业秘密是以控制器与风力机组件交互作用方式建立的。近
年来改良的控制策略,是风力机生产力提高的原因中的重要部分。An interesting strategy pursued by some manufacturers is to adapt the
operational strategy to the local wind climate. In this way it may e.g. be
possible to minimise uneconomic tear and wear on the machine during (rare)
periods of rough weather.
一些制造商从事有趣的策略,使运行策略适应当地的风力气候。例如,这种方式
可能在恶劣天气期间(较少),将电机上非经济的磨损降到最低。
Power quality 电能质量
Controlling Power Quality from Wind Turbines 控制风力机的电能质量
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Most people think of the controller as the unit which runs the wind turbine, e.g.
yaws it against the wind, checks that the safety systems are OK, and starts
the turbine.
大多数人把控制器当做一个单元,能够运行风力机,例如偏航对风,检查安全
系统是否正常,启动风力机。The controller does indeed do all these things, but it also looks after the power
quality of the current generated by the wind turbine.
控制器确实做了所有这些事情,但是它还关注风力机所产生电流的电能质量。Grid Connection and Power Quality 电网连接和电能质量In the section about power quality you will learn how electricity companies
require that wind turbines connect "softly" to the grid, and how they have
certain requirements that the alternating current and voltage move in step with
one another.
在关于电能质量的部分,你将会学习电力公司如何要求风力机“柔性地”连接
到电网,以及他们如何明确要求交流电流和电压彼此同步运行。The image to the right shows the high voltage section of a controller for a
megawatt machine. This part of the controller operates e.g. the thyristors
which ensure soft coupling to the electrical grid.
右侧图像显示了兆瓦级风机控制器的高压部分。控制器的这部分运行,例如晶闸
管,确保软连接到电网。Reactive Power Control 无功功率控制
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Voltage and current are typically measured 128 times per alternating current
cycle, (i.e. 50 x 128 times per second or 60 x 128 times per
second, depending on the electrical grid frequency). On this
basis, a so called DSP processor calculates the stability of the
grid frequency and the active and reactive power of the
turbine. (The reactive power component is basically a question
of whether the voltage and the current are in phase or not).
典型地电压和电流每个交流电周期测量 128 次,(即 50 x 128 次每秒或者 60 x
128 次每秒,取决于电网频率)。基于此,所谓的DSP处理器计算电网频率的稳
定性,以及风力机的有功和无功功率。(无功成分,基本上是电压和电流是否同
相位的问题)。In order to ensure the proper power quality, the controller may switch on or
switch off a large number of electrical capacitors which adjust the reactive
power, (i.e. the phase angle between the voltage and the current). As you can
see in the image to the left, the switchable capacitor bank is quite a large
control unit in itself in a megawatt sized machine.
为了保证适当的电能质量,控制器可能要开通和关断大量的电力电容,调节无
功功率,(即,电压和电流之间的相位角)。如左侧图像中看到的,可切换的电容
箱本身是兆瓦级容量风机中很大的一个控制单元。Electromagnetic Compatibility (EMC) 电磁兼容性(EMC)
There are very powerful electromagnetic fields
around power cables and generators in a wind
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turbine. This means that the electronics in the controller system has to be
insensitive to electromagnetic fields.
风力机内电力电缆和发电机周围有很强的电磁场。这意味着控制器系统中的电子
装置必须对电磁场不敏感。Conversely, the electronics should not emit electromagnetic radiation which
can inhibit the functioning of other electronic equipment. The image to the left
shows a radiation free room with metal walls in the laboratory of one of the
largest wind turbine controller manufacturers. The equipment in the room is
used to measure electromagnetic emissions from the components of the
controllers.
相反地,电子装置不应该发射电磁辐射,以免抑制其他电子设备的运作。左侧图
像显示了带有金属墙壁的免辐射房间,在世界上最大的风力机控制器制造商之
一的实验室内。房间内的设备用来测量控制器组件的电磁发射。
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Turbine design涡轮机设计
Load considerations 载荷考虑
Wind Turbine Design: Basic Load Considerations 风力机设计:基本载荷考虑Whether you are building wind turbines or helicopters, you have to take the
strength, the dynamic behaviour, and the fatigue properties of your materials
and the entire assembly into consideration.
不管是构建风力机还是直升机,必须考虑强度、动态行为、材料的疲劳特性以及
整体集成。
Water pumping windmill, South Australia, Photograph Soren Krohn © 1997 DWIA抽水风车,澳大利亚南部,摄影
Extreme Loads (Forces)极限载荷(应力)
Comodoro Rivadavia, Argentina (NEG Micon 750 kW turbines) Photograph Soren Krohn © 1998 DWIA
Comodoro Rivadavia,阿根廷(NEG Micon 750 kW风力机) 摄影
242
Wind turbines are built to catch the wind's kinetic (motion) energy. You may
therefore wonder why modern wind turbines are not built with a lot of rotor
blades, like the old "American" windmills you have seen in the Western
movies.
建设风力机是为了捕获风的动(运动)能。你可能因此疑惑,为什么现代风力机不
是建有很多叶片,就像在西部电影中看到的老“美国式”风车。Turbines with many blades or very wide blades, i.e. turbines with a very solid
rotor, however, will be subject to very large forces, when the wind blows at a
hurricane speed. (Remember, that the energy content of the wind varies with
the third power (the cube) of the wind speed).
具有很多叶片或很宽叶片的风力机,即风力机具有很坚实的转轮,然而当风力
以狂风的速度吹过时,会承受非常大的应力。(记着,风的能含量随风速的三次
方(立方)变化)。Wind turbine manufacturers have to certify that their turbines are built, so that
they can withstand extreme winds which occur, say, during 10 minutes once
every 50 years.
风力机制造商必须确保他们建造的风力机,能够承受发生的极端风力,比如说,
10分钟内,50年一遇。To limit the influence of the extreme winds turbine manufacturers therefore
generally prefer to build turbines with a few, long, narrow blades.
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为了限制极端风力的影响,风力机制造商因此常常愿意建设具有少的、长的、窄
的叶片的风力机。In order to make up for the narrowness of the blades facing the wind, turbine
manufacturers prefer to let the turbines rotate relatively quickly.
为了弥补叶片向风面的狭窄,风力机制造商宁愿让风机叶片相对旋转的快一些。Fatigue Loads (Forces) 疲劳载荷(应力)
Wind turbines are subject to fluctuating winds, and hence fluctuating forces.
This is particularly the case if they are located in a very turbulent wind climate.
风力机会遭受波动的风力,因此有波动的应力。特别是对于如果它们处于非常紊
乱的风力环境的情况。Components which are subject to repeated bending, such as rotor blades,
may eventually develop cracks which ultimately may make the component
break. A historical example is the huge German Growian machine (100 m
rotor diameter) which had to be taken out of service after less than three
weeks of operation. Metal fatigue is a well known problem in many industries.
Metal is therefore generally not favoured as a material for rotor blades.
承受重复弯曲的组件,例如转轮叶片,可能形成裂缝,最终可能造成组件断裂。
一个历史实例是,德国Growian大风机(100m转轮直径)运行还不到 3个星期就
失效了。金属疲劳是一个在很多行业众所周知的问题。因此金属一般不作为转轮
叶片的材料。244
When designing a wind turbine it is extremely important to calculate in
advance how the different components will vibrate, both individually, and
jointly. It is also important to calculate the forces involved in each bending or
stretching of a component.
当设计风力机时,事先计算出不同组件将会如何振动极为重要,包括单独的和
结合的组件。计算组件弯曲或拉伸相关的应力同样非常重要。This is the subject of structural dynamics, where physicists have developed
mathematical computer models that analyse the behaviour of an entire wind
turbine.
这是结构动力学学科,其中物理学家已经开发出数学计算机模型,分析风力机
整体的特性。These models are used by wind turbine manufacturers to design their
machines safely.
风力机制造商使用这些模型来安全地设计他们的风机。Structural Dynamics: An Example *) 结构动力学:一个实例A 50 metre tall wind turbine tower will have a tendency to swing back and
forth, say, every three seconds. The frequency with which the tower oscillates
back and forth is also known as the eigenfrequency of the tower. The
eigenfrequency depends on both the height of the tower, the thickness of its
walls, the type of steel, and the weight of the nacelle and rotor.
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一个 50米高的风力机塔架会有来回摆动的倾向,例如每 3秒。塔架来回振荡的
频率也被称为塔架的固有频率。固有频率既取决于塔架高度、其墙壁厚度、钢的
类型,也取决于机舱和转轮的重量。Now, each time a rotor blade passes the wind shade of the tower, the rotor
will push slightly less against the tower.
现在,每次转轮叶片经过塔架的风影,转轮将轻微推动塔架。If the rotor turns with a rotational speed such that a rotor blade passes the
tower each time the tower is in one of its extreme positions, then the rotor
blade may either dampen or amplify (reinforce) the oscillations of the tower.
如果转轮以这样的旋转速度转动,转轮叶片每次经过塔架时,塔架处于他的一
个极限位置,那么转轮叶片可能会抑制或放大(加强)塔架的振荡。The rotor blades themselves are also flexible, and may have a tendency to
vibrate, say, once per second. As you can see, it is very important to know the
eigenfreqencies of each component in order to design a safe turbine that does
not oscillate out of control.
转轮叶片自身也有弹性,也可能有振动的趋势,例如每秒一次。正如你所看到的
为了设计安全的风力机,不会振荡而失去控制,知道每个组件的固有频率是非
常重要的。
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*) A very dramatic example of structural dynamic forces at work under
influence of the wind (undampened torsion oscillations) is the famous crash of
the Tacoma Bridge close to Seattle in the United States. You may find a short
movie clip (700 K) on the disaster on the Internet.
风力影响(非阻尼的扭矩震荡)下结构动力工作的一个很生动的例子是著名的
美国西雅图 Tacoma大桥坍塌事件。你可以在互联网上找到关于这个灾难的一段
短影片剪辑(700K)。
Horizontal/vertical 水平 / 竖直
Wind Turbines: Horizontal or Vertical Axis Machines? 风力机:水平或垂直轴风机?Horizontal Axis Wind Turbines 水平轴风力机Most of the technology described on these pages is related to horizontal axis
wind turbines (HAWTs, as some people like to call them).
这些页面描述的大部分技术都与水平轴风力机有关 (一些 人喜欢称之为
HAWTs)。The reason is simple: All grid-connected commercial wind turbines today are
built with a propeller-type rotor on a horizontal axis (i.e. a horizontal main
shaft).
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原因很简单:现在所有的并网商业风力机都使用水平轴上的螺旋桨型转轮建成
(即水平主轴)。The purpose of the rotor, of course, is to convert the linear motion of the wind
into rotational energy that can be used to drive a generator. The same basic
principle is used in a modern water turbine, where the flow of water is parallel
to the rotational axis of the turbine blades.
转轮的用途,当然,是把风力的线性运动转换成能够用来驱动发电机的转动能
量。现代水轮机中使用同样的基本原理,其中水的流动与涡轮机叶片的旋转轴平
行。Vertical Axis Wind Turbines垂直轴风力机
Eole C, a 4200 kW Vertical axis Darrieus wind turbine with 100 m rotor diameter at Cap Chat, Québec, Canada. The machine (which is the world's largest wind turbine) is no longer operational. Photograph Soren Krohn
Eole C,一个 4200 kW垂直轴达里厄(Darrieus)风力机,
具有 100m 转轮直径,在卡普沙 (Cap Chat),魁北克
(Québec),加拿大。Soren Krohn摄影© 1997 DWIA
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As you will probably recall, classical water wheels let the water arrive at a
right angle (perpendicular) to the rotational axis (shaft) of the water wheel.
你可能想起来,经典水轮让水以垂直于水轮旋转轴(机械轴)的合适角度到达。Vertical axis wind turbines (VAWTs as some people call them) are a bit like
water wheels in that sense. (Some vertical axis turbine types could actually
work with a horizontal axis as well, but they would hardly be able to beat the
efficiency of a propeller-type turbine).
垂直轴风力机(一些人称之为 VAWTs)在那种意义上有点像水轮。(一些垂直轴风
机类型实际上能够与水平轴的一起工作,但是他们很难达到螺旋桨型风机的效
率)。The only vertical axis turbine which has ever been manufactured
commercially at any volume is the Darrieus machine, named after the French
engineer Georges Darrieus who patented the design in 1931. (It was
manufactured by the U.S. company FloWind which went bankrupt in 1997).
The Darrieus machine is characterised by its C-shaped rotor blades which
make it look a bit like an eggbeater. It is normally built with two or three
blades.
唯一商业上已经制造出的具有不同容量的垂直轴风力机是达里厄风机,法国工
程师 Georges Darrieus 于 1931 年取得设计的专利权后命名。 (由美国公司
FloWind 制造,1997年破产)。达里厄风机特有的地方是其C型转轮叶片,使其
看起来有点像打蛋器。通常建有 2个或 3个叶片。249
The basic theoretical advantages of a vertical axis machine are:
垂直轴风机的基本理论优势有:1) You may place the generator, gearbox etc. on the ground, and you may not
need a tower for the machine.
1)可以把发电机、齿轮箱等放置在地面上,可以不需要风机的塔架。2) You do not need a yaw mechanism to turn the rotor against the wind.
2)不需要偏航机构,来转动叶片对风。The basic disadvantages are:
基本劣势有:1) Wind speeds are very low close to ground level, so although you may save
a tower, your wind speeds will be very low on the lower part of your rotor.
1) 接近地平面的风速很低,所以尽管可以节省塔架,但是转轮较低的部分风速
会很低。2) The overall efficiency of the vertical axis machines is not impressive.
2) 垂直轴风机的总效率不令人印象深刻。3) The machine is not self-starting (e.g. a Darrieus machine will need a "push"
before it starts. This is only a minor inconvenience for a grid connected
turbine, however, since you may use the generator as a motor drawing
current from the grid to to start the machine).
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3) 风机不能自启动(例如达里厄风机启动前需要一个“推力”。然而这对于并网
风机只是一个很小的不方便之处,因为可以把发电机当做电动机使用,从电网
中提取电流来启动风机)。4) The machine may need guy wires to hold it up, but guy wires are
impractical in heavily farmed areas.
4) 风机可能需要绷绳来使其立住,但是在高度开垦的区域绷绳是不切实际的。5) Replacing the main bearing for the rotor necessitates removing the rotor on
both a horizontal and a vertical axis machine. In the case of the latter, it
means tearing the whole machine down. (That is why EOLE 4 in the picture is
standing idle).
5) 更换转轮主轴承,必须既去掉水平轴风机的转轮,又要去掉垂直轴风机的转
轮。后面一种状况下,意味着拉倒整个风机。(这就是为什么图中的 EOLE 4闲置
着的原因)。
Upwind/downwind 上风向 / 下风向
Wind Turbines: Upwind or Downwind Machines? 风力机:上风向或下风向风力机Upwind Machines 上风向风力机
251
Upwind machines have the rotor facing the wind. The basic advantage of
upwind designs is that one avoids the wind shade behind the tower. By far the
vast majority of wind turbines have this design.
上风向电机的转轮迎着风。上风向设计的基本优势是避免塔架后的风影。到目前
为止绝大部分风力机是这种设计。On the other hand, there is also some wind shade in front of the tower, i.e. the
wind starts bending away from the tower before it reaches the tower itself,
even if the tower is round and smooth. Therefore, each time the rotor passes
the tower, the power from the wind turbine drops slightly.
另一方面,也有一些风影在塔架前面,即,风力到达塔架本身之前开始弯曲远
离,即使塔架是圆的和光滑的。因此,每次转轮通过塔架,来自风力机的功率会
轻微下降。The basic drawback of upwind designs is that the rotor needs to be made
rather inflexible, and placed at some distance from the tower (as some
manufacturers have found out to their cost). In addition an upwind machine
needs a yaw mechanism to keep the rotor facing the wind.
上风向设计的基本缺陷是转轮需要制作得相当不易弯曲,并且放置距离塔架有
一定距离(因为一些制造商发现了其成本的真相)。而且上风向风机需要偏航机制
来保持转轮迎风。Downwind Machines 下风向风机
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Small downwind turbine (22 kW). You may notice that the rotor is "coning" away from the tower. Photograph Soren Krohn 小的下风向风机(22kW)。你可能注意到转轮是远离塔架的“圆锥形”。© 1998 DWIA
Downwind machines have the rotor placed on the lee side of the tower. They
have the theoretical advantage that they may be built without a yaw
mechanism, if the rotor and nacelle have a suitable design that makes the
nacelle follow the wind passively. For large wind turbines this is a somewhat
doubtful advantage, however, since you do need cables to lead the current
away from the generator. How do you untwist the cables, when the machine
has been yawing passively in the same direction for a long period of time, if
you do not have a yaw mechanism? (Slip rings or mechanical collectors are
not a very good idea if you are working with 1000 ampere currents).
下风向风机的转轮放置在塔架的背风处。他们具有理论上的优势,不需要建立偏
航机构,如果转轮和机舱具有合适的设计,使机舱被动跟随风力。然而对于大型
风力机,因为需要电缆把发电机的电流导出,这是一个有点值得怀疑的优势。如
果没有偏航机构,当风机长时间在同一个方向被动偏航时,如何解开电缆? (如
果有 1000安培的工作电流,滑环或机械采集器不是一个好想法)。A more important advantage is that the rotor may be made more flexible. This
is an advantage both in regard to weight, and the structural dynamics of the
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machine, i.e. the blades will bend at high wind speeds, thus taking part of the
load off the tower. The basic advantage of the downwind machine is thus, that
it may be built somewhat lighter than an upwind machine.
更重要的优势是转轮可以做得更有弹性。这对于考虑风机重量以及结构动力学都
是一个优势,即,叶片在高风速时会弯曲,从而去除了塔架的部分载荷。因此下
风向风机的基本优势是,可以稍微比上风向风机轻些。The basic drawback is the fluctuation in the wind power due to the rotor
passing through the wind shade of the tower. This may give more fatigue
loads on the turbine than with an upwind design.
基本缺陷是风能功率的波动,由于转轮通过塔架的风遮掩造成。这可能会比上风
向设计引起更大的风机疲劳载荷。
No. of rotor blades 转轮叶片数量
Wind Turbines: How many blades? 风力机:多少个叶片?Why Not an Even Number of Blades? 为什么不是偶数个叶片?Modern wind turbine engineers avoid building large machines with an even
number of rotor blades. The most important reason is the stability of the
turbine. A rotor with an odd number of rotor blades (and at least three blades)
can be considered to be similar to a disc when calculating the dynamic
properties of the machine.
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现代风力机工程师避免建设具有偶数个转轮叶片的大型风机。最重要的原因是风
机的稳定性。具有奇数个转轮叶片(至少 3个叶片)的转轮,当计算风机的动态特
性时,可以认为类似于一个圆盘。A rotor with an even number of blades will give stability problems for a
machine with a stiff structure. The reason is that at the very moment when the
uppermost blade bends backwards, because it gets the maximum power from
the wind, the lowermost blade passes into the wind shade in front of the
tower.
具有偶数叶片的转轮会在具有刚性结构的风机中引起稳定性问题。原因是,由于
最上面的叶片从风力中得到了最大的功率刚好向后弯曲时,而最下面的叶片进
入塔架前的风影部分。The Danish Three-Bladed Concept 丹麦三叶片概念
Most modern wind turbines are three-bladed designs with the
rotor position maintained upwind (on the windy side of the
tower) using electrical motors in their yaw mechanism. This
design is usually called the classical Danish concept , and tends
to be a standard against which other concepts are evaluated.
The vast majority of the turbines sold in world markets have this design. The
basic design was first introduced with the renowned Gedser wind turbine.
Another characteristic is the use of an asynchronous generator. You may read
more about the Danish concept in the articles section of this web site.
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大部分现代风力机是三叶片设计,转轮位置维持上风向(在塔架迎风的一面),
在其偏航机构中使用电机。这种设计常被称为经典丹麦概念,并且倾向于成为标
准,对其他概念进行评估。世界市场上出售的绝大部分风力机是这种设计。这种
基本设计首先是由知名的Gedser 风力机 引进的。另一个特性是异步发电机的使
用。你可以在这个网站的文章部分阅读更多有关丹麦概念的内容。Two-Bladed (Teetering) Concept 两叶片(跷跷板)概念
Two-bladed wind turbine designs have the advantage of saving
the cost of one rotor blade and its weight, of course. However,
they tend to have difficulty in penetrating the market, partly
because they require higher rotational speed to yield the same
energy output. This is a disadvantage both in regard to noise and visual
intrusion. Lately, several traditional manufacturers of two-bladed machines
have switched to three-bladed designs.
两叶片风力机设计当然具有节省一个叶片的成本及其重量的优势。然而,它们进
入市场往往有困难,部分因为它们需要更高的旋转速度,来产出同样的能量输
出。这在噪声及视觉侵扰上都是一个缺点。近来,几个传统的两叶片风机制造商
已经转变为三叶片设计。Two- and one-bladed machines require a more complex design with a hinged
(teetering hub) rotor as shown in the picture, i.e. the rotor has to be able to tilt
in order to avoid too heavy shocks to the turbine when a rotor blades passes
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the tower. The rotor is therefore fitted onto a shaft which is perpendicular to
the main shaft, and which rotates along with the main shaft. This arrangement
may require additional shock absorbers to prevent the rotor blade from hitting
the tower.
两叶片和单叶片风机需要更复杂的设计,具有图中所示的铰链 (跷跷板轮毂)的
转轮,即,转轮必须能够倾斜,以避免当转轮叶片通过塔架时,对风机产生过
重的冲击。因此,转轮安装在垂直于主轴的一个轴上,并随主轴旋转。这种布局
需要附加冲击减震器,防止转轮叶片撞到塔架。One-Bladed Concept 单叶片概念
Yes, one-bladed wind turbines do exist, and indeed, they save
the cost of another rotor blade! If anything can be built, engineers
will do it. One-bladed wind turbines are not very widespread
commercially, however, because the same problems that are
mentioned under the two-bladed design apply to an even larger extent to one-
bladed machines.
是的,单页片风力机确实存在,并且,确实节省了另一个转轮叶片的成本。如果
能建造任何东西,工程师都会去做。然而,单叶片风力机商业上不是很普遍,因
为两叶片设计中提到的同样的问题,应用于单叶片风机时程度会更大。In addition to higher rotational speed, and the noise and visual intrusion
problems, they require a counterweight to be placed on the other side of the
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hub from the rotor blade in order to balance the rotor. This obviously negates
the savings on weight compared to a two-bladed design.
除了更高的旋转速度、噪声以及视觉侵扰问题,还需要在转轮叶片轮毂的另一侧
放置平衡物,来平衡转轮。相对于两叶片设计,这显然抵消了重量的节省。
Optimising turbines 优化涡轮机
Optimising Wind Turbines 优化风力机Optimisation and Economics 最优化和经济性
Victoria in Southern Australia would never have been populated in the late 19th century, were it not for the water pumping windmills - and these windmills are really optimised for their purpose. Photograph Soren Krohn 摄影澳大利亚南部的维多利亚,如果不是抽水风车-并且这些风车根据人们的意图实在地得到了优化,在 19世纪末不会有人居住。Soren
Krohn摄影© 1998 DWIA
The water pumping windmills to the left look very different from modern, large
wind turbines. But they are quite sensibly designed for the purpose they
serve: The very solid rotor with many blades means that they will be running
even at very low wind speeds, and thus pumping a fair amount of water all
year round.
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左侧的抽水风车看起来与现代的大型风力机很不一样。但他们很聪明地为他们的
服务目的而设计。带有很多的叶片的非常坚固的转轮,意味着它们即使在很低的
风速都可以转动,从而一年四季抽取大量的水。Clearly, they will be very inefficient at high wind speeds, and they will have to
shut themselves down, and yaw out of the wind in order to avoid damage to
the turbine, due to the very solid rotor. But that does not really matter: We do
not want them to empty the wells and flood the water tank during a gale.
显然,高风速时它们的效率很低,并且必须关闭自身,由于很坚固的转轮,偏
航远离风力,以避免损坏风力机。但是实际上这没有关系:大风期间,我们不需
要它们清空水井和注满水箱。The ideal wind turbine design is not dictated by technology alone, but by a
combination of technology and economics: Wind turbine manufacturers wish
to optimise their machines, so that they deliver electricity at the lowest
possible cost per kilowatt hour (kWh) of energy.
理想的风力机设计不是只由技术规定的,而是技术与经济性的结合:风力机制
造商希望他们的风机最优,从而能以每千瓦时(kWh)能量最低可能的成本提供
电能。But manufacturers are not very concerned about how efficiently they use the
wind resource: The fuel is free, after all.
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但是制造商不是很关心如何有效地使用风力资源:毕竟燃料是免费的。It is not necessarily a good idea to maximise annual energy production, if that
means that one has to build a very expensive wind turbine. In the next
sections we shall look at some of the choices manufacturers have to make.
年发电量最大化未必是一个好主意,如果那意味着必须建立非常昂贵的风力机。
接下来的章节,将看到一些制造商必须作出的选择。Relative Generator and Rotor Size 发电机和转轮的相对尺寸A small generator, (i.e. a generator with low rated power output in kW)
requires less force to turn than a large one. If you fit a large wind turbine rotor
with a small generator it will be producing electricity during many hours of the
year, but it will capture only a small part of the energy content of the wind at
high wind speeds.
小发电机(即,发电机具有 kW的低额定功率)比大的需要更小的应力来转动。如
果安装一个带有小发电机的大型风力机,它会在一年里大部分小时内发电,但
是它在高风速时只能捕获很小一部分风的能量。A large generator, on the other hand, will be very efficient at high wind
speeds, but unable to turn at low wind speeds.
另一方面,大发电机在高风速时会很高效,但是在低风速时不能转动。Clearly, manufacturers will look at the distribution of wind speeds and the
energy content of the wind at different wind speeds to determine the ideal
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combination of the size of the rotor and the size of the generator at different
wind turbine sites.
显然,制造商将考虑风速分布和不同风速的风能能量,来确定不同风机场址转
轮尺寸和发电机尺寸的理想组合。Fitting a wind turbine with two (or more) generators can sometimes be an
advantage, but whether it really pays to do it depends on the electricity price.
安装具有两个(或多个)发电机的风力机有时是一种优势,但是是否真的值得去
做取决于电价。Tower Heights 塔架高度In the section on wind shear, you have learned that taller towers generally
increase a wind turbine's energy production.
在关于风切变的章节,你已经学习了更高的塔架通常会增大风力机的能量产出。Once again, whether a taller tower is worth the extra cost depends both on
the roughness class, and the cost of electricity.
再次,是否值得增加额外的费用采用更高的塔架取决于粗糙度等级和发电成本。
Low mechanical noise 低机械噪声
Designing for Low Mechanical Noise from Wind Turbines 风力机低机械噪声的设计
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Sound emissions from wind turbines may have two different origins:
Mechanical noise which we deal with on this page, and aerodynamic noise
which we deal with on the next page.
风力机的发声可能有两个不同的起源:本页涉及的机械噪声,以及下一页涉及
的气动噪声。Mechanical Sources of Sound Emission 发声的机械源Mechanical noise, i.e. metal components moving or knocking against each
other may originate in the gearbox, in the drive train (the shafts), and in the
generator of a wind turbine.
机械噪声,即,金属组件的运动或互相撞击,可能来源于风力机的齿轮箱、驱动
链(轴)以及发电机。Machines from the early 1980s or before do emit some mechanical noise,
which may be heard in the immediate surroundings of the turbine, in the worst
cases even up to a distance of 200 m (600 ft.)
八十年代早期及以前的电机确实会发出一些机械噪声,在紧挨着风力机的环境
中可以听到,最坏的情况甚至近到 200米(600英尺)的距离。A survey on research and development priorities of Danish wind turbine
manufacturers conducted in 1995, however, showed that no manufacturer
considered mechanical noise as a problem any longer, and therefore no
further research in the area was considered necessary. The reason was, that
within three years noise emissions had dropped to half their previous level
due to better engineering practices.
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然而 1995年丹麦风力机制造商进行的一项关于研究和开发优先权的调研,显
示没有制造商仍然认为机械噪声是个问题,并且因此不认为这个领域进一步的
研究是必要的。原因是,由于更好的工程实践,三年内噪声发射已经降至以前水
平的一半。Quieting Wind Turbine Gearboxes 使风力机齿轮箱安静Gearboxes for wind turbines are no longer standard industrial gearboxes, but
they have been adapted specifically for quiet operation of wind turbines. One
way of doing this is to ensure that the steel wheels of the gearbox have a
semi-soft, flexible core, but a hard surface to ensure strength and long time
wear.
用于风力机的齿轮箱不再是标准的工业齿轮箱,但是为了风力机的安静运行,
它们已经进行了特殊改造。这样做的一个方法是保证齿轮箱的钢轮有一个半软、
弹性的核心,但是有坚硬的表面来保证强度和长时间的磨损。The way this is done is basically to heat the gear wheels after their teeth have
been ground, and then let them cool off slowly while they are packed in a
special high carbon-content powder. The carbon will then migrate into the
surface of the metal. This ensures a high carbon content and high durability in
the surface of the metal, while the steel alloy in the interior remains softer and
more flexible.
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这样做的方式基本上是在齿被挤压后加热齿轮,然后当它们被一种特殊的高含
碳量粉末填塞时,让它们慢慢冷却。然后碳将迁移到金属表面。这保证了金属表
面的高含碳量和高耐久力,同时内部的钢合金保持更软和更有弹性。Structural Dynamics Analysis 结构动力学分析When going by car, plane, or train, you may have experienced how resonance
of different components, e.g. in the dashboard of a car or a window of a train
may amplify noise.
当乘坐汽车、飞机或火车,你可能经历过不同部件的共振,例如,在汽车的仪表
板或火车车窗内可能放大噪声。An important consideration, which enters into the turbine design process
today, is the fact that the rotor blades may act as membranes that may
retransmit noise vibrations from the nacelle and tower.
现在进入了风力机设计过程的一个重要的考虑是,转轮叶片作为膜可以转播机
舱和塔架的噪声振动这样的事实。As explained in the tour section on Research and Development, the turbine
manufacturers nowadays make computer models of their machines before
building them, to ensure that the vibrations of different components do not
interact to amplify noise.
如授课章节关于研究与开发所解释的,风力机制造商现在在建立风机之前制作
计算机模型,保证不同部件的振动不会相互作用而放大噪声。264
If you look at the chassis frame of the nacelle on some of the large wind
turbines on the market today, you may discover some odd holes which were
drilled into the chassis frame for no apparent reason. These holes were
precisely made to ensure that the frame will not vibrate in step with the other
components in the turbine.
如果你观察现在市场上一些大型风力机机舱的底盘框架,你可能会发现一些奇
怪的孔洞钻在了底盘框架上,但是没有明显的理由。正是制作这些孔洞,来保证
框架不会与风力机的其他部件同步振动。Sound Insulation 隔音Sound insulation plays a minor role in most wind modern turbines on the
market today, although it can be useful to minimise some medium- and high-
frequency noise. In general, however, it seems to be more efficient to attack
noise problems at the source, in the structure of the machine itself.
隔音在如今市场上大部分现代风力机中的作用不大,尽管它对于降低一些中频
和高频噪声很有用。然而一般来说,在风机自身的结构上,在源头上阻击噪声问
题,似乎更加有效。
Low aerodynamic noise 低气动噪声
Designing for Low Aerodynamic Noise from Wind Turbines 风力机低气动噪声的设计Aerodynamic Sources of Sound Emission 发声的气动源
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When the wind hits different objects at a certain speed, it will generally start
making a sound. If it hits the leaves of trees and bushes, or a water surface it
will create a random mixture of high frequencies, often called white noise.
当风以一定的速度击打不同的物体,一般将开始制造声音。如果它击打树木和灌
木的叶子或水面,将产生随机的高频混合,通常称为白噪声。The wind may also set surfaces in vibration, as sometimes happens with parts
of a building, a car or even an (engineless) glider aeroplane. These surfaces
in turn emit their own sound. If the wind hits a sharp edge, it may produce a
pure tone, as you can hear it from musical wind instruments.
风也可能在表面产生振动,就像有时候和建筑物、汽车或者甚至滑翔机 (无发动
机)一起发生。这些表面依次发出他们自己的声音。如果风击打锋利的边缘,可能
会产生一个纯音,就像从管乐器听到的一样。Rotor Blade Sound Emission and the Fifth Power Law 转轮叶片发声和五次方定律Rotor blades make a slight swishing sound which you may hear if you are
close to a wind turbine at relatively low wind speeds.
转轮叶片产生轻微的嗖嗖声,如果你在风速相对低时接近风力机,就可以听到。Rotor blades must brake the wind to transfer energy to the rotor. In the
process they cause some emission of white noise. If the surfaces of the rotor
blades are very smooth (which indeed they must be for aerodynamic
reasons), the surfaces will emit a minor part of the noise. Most of the noise
will originate from the trailing (back) edge of the blades. Careful design of
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trailing edges and very careful handling of rotor blades while they are
mounted, have become routine practice in the industry.
转轮叶片必须制动风力,将能量转移到转轮。在这个过程中会造成一些白噪声的
发射。如果转轮叶片的表面很光滑(由于空气动力学原因它们必须这样),表面将
发出很小一部分噪声。大部分噪声来源于叶片的后(后面)缘。后缘的仔细设计以
及转轮叶片安装时的小心处理,已经变成业界的常规做法。Other things being equal, sound pressure will increase with the fifth power of
the speed of the blade relative to the surrounding air. You will therefore notice
that modern wind turbines with large rotor diameters have very low rotational
speed.
其他条件一样,声压会随着叶片相对于环境空气的转速的五次方增大。因此你将
注意到具有大的转轮直径的现代风力机,旋转速度很低。Rotor Blade Tip Design 转轮叶片叶尖设计Since the tip of the blade moves substantially faster than the root of the blade,
great care is taken about the design of the rotor tip. If you look closely at
different rotor blades you will discover subtle changes in their geometry over
time, as more and more research in the area is being done.
因为叶片叶尖的运动要比叶片根部快很多,需要非常注意转轮叶尖的设计。如果
你接近不同转轮叶片观察,会发现其几何形状随着时间有细微的变化,这个领
域越来越多的研究正在进行。267
The research is also done for performance reasons, since most of the torque
(rotational moment) of the rotor comes from the outer part of the blades. In
addition, the airflows around the tip of rotor blades is extremely complex,
compared to the airflow over the rest of the rotor blade.
进行此研究还有性能的原因,因为转轮大部分的转矩(转动力矩)来自于叶片外
端的部分。另外,与转轮叶片其余部分的气流相比较,转轮叶片叶尖附近的气流
相当复杂。Research on Quieter Blades 对更安静叶片的研究Research on quieter rotor blades continues, but as mentioned in the section
Noise is a Minor Problem, most of the benefits of that research will be turned
into increased rotational speed and increased energy output, since noise is
generally not a problem per se, given the distances to neighbouring houses
etc.
对更安静转轮叶片的研究在继续,但是正如噪声是个小问题一节中提到的,研
究的大部分好处是变成增大旋转速度和增加能量输出,因此如果给定相邻房屋
的距离等,噪声本身一般不是问题。
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Manufacturing 制造业
Nacelles 机舱
Manufacturing Wind Turbine Nacelles 制造风力机机舱Take a 360° Panoramic View (QuickTime VR) into a Wind Turbine Factory风力机工厂内的 360°全景图(QuickTime VR)(Photographs Soren Krohn 摄影© 1999 DWIA)Hold the mouse down on the picture and drag gently right, left, up or down to
pan or tilt the camera. Use the shift key to zoom in, use the ctrl key to zoom
out. This image (364K) requires a QuickTime plugin in your browser. You may
download the necessary plugin and a QuickTime player from Apple's web site.
在图片上按住鼠标放,轻轻拖动右、左、上或下平移或倾斜相机。使用 shift键来
放大,使用 Ctrl键来缩小。这张图片(364K)需要在浏览器中增加QuickTime
插件。你可以从苹果公司网站下载必要的插件和QuickTime播放器。
Blade testing 叶片测试
Testing Wind Turbine Rotor Blades 测试风力机转轮叶片Fatigue Testing of Rotor Blades 转轮叶片的疲劳测试
Video Soren Krohn 摄像© 1999 DWIA Click on image to restart video
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点击图像重启视频
The video to the left (122 K) shows how a 32 m rotor blade is fatigue tested by
being bent cyclically in a flapwise direction for 5 million full cycles. A full
flapwise test thus takes about three months.
左侧视频(122K)显示了一个 32米转轮叶片的疲劳测试,通过 500万次全周期上
下挥舞(flapwise)的轮转弯曲试验。因此一个完整的上下挥舞 测试需要约 3个月。If you look closely to the left you can see another (shorter) rotor blade being
bent cyclically in an edgewise (chordwise) direction.
如果你仔细看左边,可以看到另一个(短的)转轮叶片正进行摆动方向(弦向)轮转
弯曲。In both cases the blades are bent using a cycle close to the natural frequency
of the blade.
两种状况下,叶片的弯曲使用接近叶片固有频率的周期。The natural frequency is the frequency with which the blade will oscillate back
and forth, if you push it once in a certain direction and let go. The natural
frequencies are different in the flapwise and edgewise direction: The blade
tends to be much stiffer in the edgewise direction, thus it has a higher natural
frequency for edgewise bending.
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如果在一定方向推它一次并放手,固有频率是叶片来回振荡的频率。固有频率在
挥舞和摆动方向是不同的:叶片在摆动方向趋于更加坚固,因此对于摆动弯曲
具有更高的固有频率。Each blade is set in motion by an electric motor mounted on the blade which
swings a weight up and down. The foundations which carry the blade socket
have to be very solid: The foundation for the large blade socket consists of
2,000 tonnes of concrete.
每个叶片通过固定在叶片上的电机来设置运动,叶片使一重物上下摆动。支撑叶
片插座的基础必须很坚固:大型叶片插座的基础由 2000吨混凝土构成。This video was shot at the rotor blade test facility of the Risoe National
Laboratory Sparkær Test Centre in Jutland, Denmark. (Type approval
requirements for rotor blades are very strict in Denmark, requiring physical
testing of rotor blades for both fatigue properties (fatigue testing) and strength
properties (static testing). Other countries usually have less stringent
requirements for type approval of rotor blades).
这段视频拍摄于里索(Risoe)国家实验室 Sparkær测试中心的转轮叶片测试厂,
位于丹麦日德兰半岛。(在丹麦转轮叶片型式认证的要求很严格,需要转轮叶片
的物理测试,既有疲劳特性(疲劳测试),也有强度特性(静态测试)。其他国家对
转轮叶片型式认证的要求没那么严格)。
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Rotor Blade Materials 转轮叶片材料Rotor blades are usually made using a matrix of fibre glass mats which are
impregnated with a material such as polyester (GRP = Glass fibre reinforced
polyester). The polyester is hardened after it has impregnated the fibre glass.
Epoxy may be used instead of polyester. Likewise the basic matrix may be
made wholly or partially from carbon fibre, which is a lighter, but costlier
material with high strength. Wood-epoxy laminates are also being used for
large rotor blades.
转轮叶片通常使用玻璃纤维垫基质制作,玻璃纤维使用诸如聚酯的材料浸渍
(GRP=玻璃纤维增强聚酯)。聚酯浸渍玻璃纤维之后,便硬化。同样,基质可以全
部或部分使用碳纤维制作,碳纤维是昂贵但是强度高。可以使用环氧来代替聚酯
环氧树脂层压板也被用于大型转轮叶片。The Purpose of Testing Rotor Blades 测试转轮叶片的目的The purpose of rotor blade testing is to verify that laminations in the blade are,
safe, i.e. that the layers of the rotor blade do not separate (delamination).
Also, the test verifies that the fibres do not break under repeated stress.
转轮叶片测试的目的是为了确认叶片中层板的安全,即,转轮叶片中的层没有
分离(分层)。而且,测试确认纤维在重复张力下没有断裂。Measuring Strains 测量拉力
Photograph Soren Krohn © 1999 DWIA摄影
272
Strain gauges, (i.e. flat electrical resistors which are glued on to the surface of
the rotor blades being tested), are used to measure very accurately the
bending and stretching of the rotor blades.
应变仪,(即,粘在被测转轮叶片表面的扁平电阻器)用于非常精确地测量转轮
叶片的弯曲和拉伸。Monitoring Fatigue Testing监控疲劳测试
Photograph Soren Krohn © 1999 DWIA摄影
The measurement results from the strain
gauges are continuously monitored on computers. Nonlinear variations in the
pattern of bending may reveal a damage in the rotor blade structure.
应变仪的测量结果持续地被计算机监控。挠度式样上的非线性振动可以揭示转轮
叶片结构的破坏。Infrared Inspection (Thermography) 红外线检测(热成像)
Infrared cameras are used to reveal local build-up of heat in the blade. This
may either indicate an area with structural dampening, i.e. an area where the
blade designer has deliberately laid out fibres which convert the bending
energy into heat in order to stabilise the blade, or it may indicate an area of
delamination or an area which is moving toward the breaking point for the
fibres.
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红外线照相机用来揭示叶片局部积聚的热量。这要么可以指出具有结构阻尼的区
域,即一个叶片设计者专门布置纤维的区域,纤维把弯曲能量转化为热量以稳
定叶片,要么可以指出分层区域或者向着纤维断裂点移动的区域。Modal Forms of Rotor Blade Vibrations 转轮叶片振动的模态形式From the year 2000 blade testing (in Denmark) also includes a verification of
the different modal forms of vibration of each blade. This is done using a
special type of equipment which excites the blade vibrations at different
frequencies and in different directions.
从 2000年起,叶片测试(在丹麦)也包括每个叶片不同振动模态型式的核查。这
是使用特型设备完成的,设备以不同的频率和不同的方向引起叶片振动。Different modal forms of oscillation are also known when building musical
instruments: A string on a violin may oscillate with is basic tone, i.e. the centre
of the string moving up and down, but it will usually also oscillate with the first
overtone or first harmonic, with two centres of oscillation located at a distance
of 1/4 from each end of the string, moving at twice the frequency of the basic
tone or natural frequency.
当制造乐器时,不同振荡模态型式也很有名:小提琴的弦可以以基调振荡,即
弦的中间上下运行,但是它也常常以一次泛音或一次谐波振荡,具有两个振荡
中心,位于距离弦的每个末端的 1/4处,以基调频率或固有频率的两倍运动。
274
The reason why manufacturers of wind turbines are interested in studying and
verifying the various forms of vibration frequencies in rotor blades, is that they
have to make sure that the turbine on which the blade is to be mounted does
not have some of the same natural frequencies as the rotor blade. Otherwise,
a resonance may occur in the whole structure of the turbine, leading to
undampened vibrations which may eventually wreck the whole wind turbine.
We will return to this issue on the page on structural dynamics in the design
section later in this guided tour.
制造商为什么有兴趣研究和核查转轮叶片振动频率的各种形式,在于他们必须
弄清楚,有叶片固定在上面的风力机不能如转轮叶片一样具有同样的固有频率。
否则,风力机的整体结构可能产生谐振,导致不衰减的振动,可能最终摧毁整
个风力机。以后,在本指导设计部分中的关于结构动力学的一节中,我们将回到
这个问题。Static Testing of Rotor Blades 转轮叶片的静态测试Rotor blades are also tested for strength (and thus their ability to withstand
extreme loads) by being bent once with a very large force. This test is made
after the blades has been subject to fatigue testing, in order to verify the
strength for a blade which has been in operation for a substantial amount of
time.
275
转轮叶片也通过弯曲进行强度测试(从而是他们承受极限载荷的能力),一次弯
曲用很大的应力。这项测试在叶片承受完疲劳测试后进行,为了核查已经运行了
大量时间的叶片强度。
Towers 塔架
Manufacturing Wind Turbine Towers 制造风力机塔架Rolling Conical Tower Sections轧制圆锥形塔架段
All photographs Soren Krohn 所有摄影© 1999 DWIA
Most modern wind turbine towers are conical tubular steel towers, as we
learned on the page about wind turbine towers.
大部分现代风力机塔架是圆锥形钢管塔架,如同我们在关于风力机塔架一节中
所学。276
This image from a tower manu- facturer's workshop shows how a steel plate
is rolled into a conical subsection for a wind turbine tower. It is a bit tricky to
achieve the conical shape, since the tension (pressure) of the steel rollers has
to be different at the two sides in order to make the plate bend properly.
这张塔架制造商车间的图片显示了,钢板如何轧制成风力机塔架的圆锥形分段。
获得圆锥形状有一点复杂,为了使平板得到合适地弯曲,因此钢辊的张力(压
力)在两侧必须不同。Towers are assembled from these smaller, conical subsections which are cut
and rolled into the right shape, and then welded together.
塔架是由这些更小的、切割和卷绕成合适形状的圆锥形分段组装而成,然后焊接
在一起。Towers are usually manufactured in 20 to 30 m sections (65 to 100 ft.), the
limiting factor being transportation on roads or rail. Typical modern tower
weights are 40 metric tonnes for a 50 m (165 ft.) tower for a turbine with a 44
m rotor diameter (600 kW), and 80 metric tonnes for a 60 metre tower for a 72
m rotor diameter (2000 kW).
塔架的制造通常有 20到 30个节段(65到 100英尺),制约因素是公路或铁路运
输。对于 50m(165英尺)塔架,具有 44米转轮直径的风力机(600kW) , 典型的
现代塔架重量是 40公吨;对于 60米塔架,72米转轮直径(2000kW),是 80公
吨。277
Designed by the Turbine Manufacturer 由风力机制造商设计Towers for wind turbines are generally designed by each turbine
manufacturer, since the entire wind turbine has to be type approved as a unit.
(The reasons are explained in the page about structural dynamics). So even if
some towers are manufactured by independent producers, they are always
specific for each manufacturer.
风力机塔架一般由每个风力机制造商设计,因为整个风力机必须作为一个单元
进行型式认证。(原因在关于结构动力学的一节中得到了解释)。所以即使有一些
塔架是由独立的生产者制造,它们也是为每个制造商定制的。Independent tower manufacturers are often also manufacturers of oil tanks or
pressure vessels, since the machinery and safety inspection procedures are
very similar.
独立的塔架制造商往往也是油箱或压力容器的制造商,因为机械和安全检测的
程序非常相似。Weight Matters 重量问题Tower weights (per installed power in kW) have declined by about 50% during
the past five years due to more advanced design methods. Still, towers are a
fairly heavy part of the wind turbine, so transportation costs are important. For
larger markets it generally does not pay to transport towers more than 1000
km (600 miles) by road. In case the distance is larger (and the project is a
large one), towers are usually manufactured locally.
278
过去 5年里,由于更先进的设计方法塔架重量(每 kW安装功率)已经下降了
50%,。塔架依然是风力机相当沉重的部分,所以运输成本很重要。对于更大的
市场,一般不支付塔架超过 1000公里(600英里)的公路运输。在距离更大的情
况(而且是大项目),塔架常在本地制造。Banana Peel Shaped Plates 香蕉皮型平板In order to end up with a cone-shaped
section, the plate used for rolling has to be
curved along the longest edges, and the
short edges are not parallel. Most tower
manufacturers use programmable laser
cutting tools in order to obtain the
appropriate shape for the steel plate.
为了以锥形分段结束,用于卷轧的平板必须沿着最长的边缘弯曲,而且短边缘
不平行。大部分塔架制造商使用可编程激光切割工具,以取得合适地钢板形状。
Welding towers 焊接塔架
Welding Wind Turbine Towers 焊接风力机塔架Steel Sections are Powder Welded钢段的粉末焊接
All photographs Soren Krohn 所有摄影© 1999 DWIA
279
Each tower section is welded with a seam lengthwise, plus a circular welding
seam to connect to the next section of the tower. This is done by placing the
tower sections on a rolling bed which slowly rotates the tower, while an
operator with a powder welding machine welds the sections from the
outside...
...and another operator welds a
corresponding set of seams on the
inside.
每个塔架分段都有一个纵向焊接缝,加
上连接塔架下一个分段的环向焊接缝。
这是通过把塔架分段放在一个卷轧床上完成的,卷轧床慢慢转动塔架,同时一
个操作员使用粉末焊接机从外面焊接各分段,另一个操作员在内部焊接对应的
接缝部分。
Checking Welding Seams for Safety 为安全起见检查焊接缝Welding seams in towers are checked using ultrasonic or x-ray devices.
Important seams are checked 100%, while other seams are checked on a
sample basis.
使用超声波或 x射线装置检查塔架的焊接缝。重要的焊缝 100%检查,其他焊缝
以抽样方式检查。
280
Installing towers 安装塔架
Installing and Assembling Wind Turbine Towers 安装和组装风力机塔架Attaching Towers to their Foundations把塔架附着在其基础上
Towers are usually bolted onto the concrete foundations on which they are
placed.
塔架通常用螺栓接在放置他们的混凝土基础上。
There are other methods, however, as in this case where part of the bottom
section of the tower is cast into the concrete foundation, and where the lowest
section of the tower is subsequently welded together directly on the site.
然而还有其他方法,在这种状态下,其中塔架底部的部分浇铸进混凝土基础,
随后塔架最下段直接与地基焊接在一起。
All pictures Soren Krohn 所有照片© 1999 DWIA
281
This method requires that the tower be fitted with special guides and clamps
to hold the two tower sections in place while the welding is being done. It also
requires a small mobile tower factory including a generator, welding gear, and
x-ray inspection equipment for checking the welding seams.
这种方法要求使用具体指导和夹具安装塔架,在焊接时,夹具保持塔架的两部
分在合适位置。同时需要一个小型移动的塔架工厂,包括发电机、焊接齿轮,以
及 x射线检测装置来检查焊接缝。Flanges 法兰Wind turbine tower sections are bolted
together using hot rolled steel flanges,
which are welded to the end of each tower
section.
风力机塔架各段使用热轧钢法兰栓接在一起,
法兰焊接在每个塔架段的末端。The flanges are made from killed steel. The image shows a pair of flanges.
法兰由脱氧钢制成。图像显示了一对法兰。Bolt Assembly螺栓装配The next image shows how the tower sections are bolted together inside the
tower.
282
下一个图显示了塔架两段如何在塔架内部栓接在一起。The quality of the flanges and the bolt tensions are important parameters for
the safety of wind turbine towers.
法兰的质量和螺栓拉力对于风力机塔架安全是重要参数。
Offshore foundations 海上基础
Building Gravity Foundations for Offshore Wind Turbines (QuickTime Video)
建立海上风力机的重力基础(QuickTime视频)
(Videos Soren Krohn © 2000 DWIA)摄像Casting Foundations浇注基础This video shows workers casting concrete for the gravity foundations of the
Middelgrunden wind farm off the coast of Copenhagen, Denmark. (The video
runs for 1 minute and 10 seconds, 1087 K, English soundtrack included, free
QuickTime plug in required).
这段视频显示了工人正在为重力基础浇注混凝土,在远离丹麦哥本哈根海岸的
Middelgrunden风电场。(视频运行 1分钟 10秒,1087K,包含英语配乐,需要
免费的QuickTime 插件)
These foundations are a hybrid between steel and concrete foundations,
since concrete is only used as ballast in the bottom section (the cylindrical 17
m slab).
283
这些基础是钢筋和混凝土基础的混合,因为混凝土仅用作底部的压舱物(17米
筒形板)。These foundations were lifted by a floating crane and sailed out to their final
destination, the Middelgrunden, in August 2000.
这些基础均由浮游起重器升起并驶向最终目的地,Middelgrunden,2000年 8
月。Building Ice Reinforcement 建造冰增强系统T his video shows the casting of ice reinforcement. (The video runs for 2
minutes and 34 seconds, 2074 K, English soundtrack included, free
QuickTime plug in required).
T his 视频显示了冰增强系统的浇筑 (视频运行 2分钟 34秒,2074K,包含英语
配乐,需要免费的QuickTime 插件)
The Middelgrunden Offshore Wind Turbine Project /Middelgrunden 海上风力机项目The project consists of 20 wind turbines of 2 MW each, with 76 m (250 ft.)
rotor diameter. The turbines were installed in September 2000 approximately
2 km from the shore of Copenhagen at 4-5 m water depth in the Øresund
strait between Denmark and Sweden.
284
项目由 20个风力机构成,每个 2MW,转轮直径 76米(250英尺)。这些风力机
均安装于 2000年 9月,距离哥本哈根海岸约 2km,水深 4-5米处,位于丹麦与
瑞典之间的Øresund海峡。The Middelgrunden Co-operative / Middelgrunden合作This project originated as a co-operative effort from an environmentalist group
in Copenhagen, Middelgrundens Vindmøllelaug, but it was built in co-
operation with the Copenhagen municipal electricity company, Københavns
Energi.
这个项目最初是作为哥本哈根一家环保团体 Middelgrundens Vindmøllelaug 协
作努力的结果,但是其建立与哥本哈根市电力公司 Københavns Energi进行合
作。Each share entitles the owner to the revenues from the sale of 1,000 kWh of
electricity (in an average wind year). The details of the project may be seen
on the web site of the co-operative: www.middelgrunden.dk.
每股股份都使所有者从销售 1000kWh电中获益 (在平均风力年)。项目细节可以
在合作网站上看到:www.middelgrunden.dk.
Want to Learn More? 需要学更多?If you wish to learn more about offshore wind energy, take the Guided Tour
section of this web site.
如果你希望学习更多有关海上风能的内容,带上这个网站的指导这一节。285
R & D研究与开发
R & D in wind 风力的研究与开发
Research and Development in Wind Energy 风能的研究与开发For wind turbine manufacturers, the basic aim of research and development
of wind turbines is to be able to manufacture ever more cost effective
machines.
对于风力机制造商而言,研究和开发风力机的基本目标是能够制造更有成本优
势的风机。Basic Aerodynamics Research基本气动研究
Photograph of computer simulation of airflows around a rotor blade © Risoe National Laboratory, Denmark
转轮叶片周围气流的计算机仿真照片© Risoe国家实验室,
丹麦Wind turbines engineers use techniques such as stall, which aircraft
designers try to avoid at all costs. Stall is a very complex phenomenon,
because it involves airflows in three dimensions on wind turbine rotor blades.
(e.g. the centrifugal force will induce an airflow which makes the air molecules
move radially along the rotor blade from its root towards the tip of the blade).
286
风力机工程师使用例如失速技术,飞行器设计者尽量不惜代价避免失速。失速是
很复杂的现象,因为它涉及到风力机转轮叶片三维的气流。 (例如,离心力会引
起气流使空气分子沿着转轮叶片,从其根部向叶尖快速运动)。3D computer simulations of airflows are rarely used in the aircraft industry, so
wind turbine researchers have to develop new methods and computer
simulation models to deal with these issues.
气流的三维(3D)计算机仿真应用于航空工业,因此风力机研究人员必须开发新
的方法以及计算机仿真模型,来处理这些问题。Computational Fluid Dynamics, or CFD, is a group of methods that deal with
simulating airflows around e.g. rotor blades for wind turbines.
计算流体动力学,或 CFD,是一组方法,处理例如风力机转轮叶片周围的模拟
气流。The picture shows a computer simulation of the airflows and pressure
distributions around a wind turbine rotor blade moving towards the left.
图片显示了风力机转轮叶片周围的气流和压力分布向左运动的计算机仿真。Aerodynamic Improvement Devices 气动改进装置A number of technologies known from the aircraft industry are increasingly
being applied to improve the performance of wind turbine rotors.
航空工业知名的大量技术,越来越多地被应用于提高风力机的转轮性能。
287
One example is vortex generators, which are small fins, often only about 0.01
metre (0.4 inch) tall, which are fitted to the surface of aircraft wings. The fins
are alternately slightly skewed a few degrees to the right and the left. The fins
create a thin current of turbulent air on the surface of the wings. The spacing
of the fins is very accurate to ensure that the turbulent layer automatically
dissolves at the back edge of the wing.
一个例子是涡流发动生器,是很小的翼,常常只有大约 0.01米(0.4英寸)高,安
装于航空机翼的表面。这些翼交替地向左和向右轻微偏斜少许角度。这些翼在机
翼表面引起湍流空气中的微弱涌流。这些翼的间隔很精确,保证机翼后缘的湍流
层自动消散。Curiously, this creation of minute turbulence prevents the aircraft wing from
stalling at low wind speeds.
好奇的是,这种微小湍流的创造可以防止航空机翼在低风速时失速。Wind turbine blades are prone to stalling even at low wind speeds close to the
root of the blade where the profiles are thick.
风力机叶片接近叶片根部剖面较厚的地方,甚至在低风速都
倾向于失速。Consequently, on some of the newest rotor blades you may find a stretch of
one metre or so along the back side of the blade (near the root) equipped with
a number of vortex generators.
288
结果是,在一些最新的转轮叶片上,你可能发现沿着叶片背后约为一米的一段,
装备了大量的涡流发生器。(Picture © LM Glasfiber A/S).照片
Research in offshore 海上研究
Offshore Wind Power Research 海上风力发电研究 Vindeby Offshore Wind Farm Photograph © 1992 Bonus Energy A/S
Vindeby海上风电场,摄影©1992 Bonus能源 A/S
Megawatt sized wind turbines, cheaper
foundations and new knowledge about
offshore wind conditions is improving the economics of offshore wind power.
兆瓦级容量的风力机、更便宜的基础和海上风力条件的新知识,正在提高海上风
电的经济性。While wind energy is already economic in good onshore locations, wind
energy is about to cross another frontier: The economic frontier set by
shorelines. Researchers and developers are about to challenge conventional
wisdom on electricity generating technologies: Offshore wind energy is rapidly
becoming competitive with other power generating technologies.
289
当风能已经在陆上非常具有经济性的时候,风能将要跨越另一个边界:海岸线
设定的经济边界。研究者和开发者将挑战常规的发电技术:和其他发电机比较,
海上风能很快变得更有竞争力。The Danish Plan 21 丹麦的 21 计划According to The Danish Governments' Action Plan for Energy, Energy 21
(see the Links page), 4,000 MW of offshore wind power should be installed
before year 2030. Onshore the target was 1,500 MW. All together Denmark
would then be able to cover more than 50 per cent of the total electricity
consumption by wind energy. In 2003, the installation in Denmark amounted
to approx. 2,600 onshore and just under 400 MW offshore.
根据丹麦政府的能源行动计划,能源 21(见链接叶面),2030年以前海上风力发
电装机达到 4000兆瓦。陆上目标是 1500兆瓦。加在一起,丹麦风能将覆盖总电
力消耗的 50%以上。2003年,丹麦安装数量达到陆上约 2600个,海上略低于
400兆瓦。A total of 5,500 MW of wind power in the Danish electricity system means that
the wind turbines periodically will cover more than 100 per cent of Danish
electricity demand. Therefore, the future Danish offshore power plants should
be an integrated part of the Scandinavian electricity system, which is based
on huge amounts on hydro power.
With a total investment of some 48 billion DKK (= 7 billion USD) for the 4,000
MW offshore capacity the Danish action plan will be the world's largest
investment in wind power ever.
290
丹麦电力系统中总计 5500兆瓦的风力发电意味着,风力机将会周期性地 100%
以上覆盖丹麦的电力需求。因而,未来的丹麦海上风力发电场将会成为基于大量
水电的斯堪的纳维亚电力系统中完整的一部分。Offshore Timetable in Denmark 丹麦海上时间表I 1998, the Danish utility companies received an executive order from the
Danish Government to build 750 MW offshore wind power, divided between
five demonstration wind farms. The two first of the large demonstration farms
were Horns Rev with 160 MW (2002) and Nysted with 158 MW (2003). In
2002, the executive order was altered to only these two wind farms. The three
remaining wind farms will be put out to tender (expected at the end of 2003).
1998年,丹麦公共事业公司从丹麦政府获取了一项建设 750兆瓦海上风力发电
的行政命令,分为 5个示范风电场建设。前两个大型示范风电场是 Horns Rev
160兆瓦(2002)和Nysted 158兆瓦(2003)。2002年,行政命令更改为只有这两
个风电场。剩余三个风电场将招标(预期在 2003末)。A report drafted by the Danish power companies for the Minister of
Environment and Energy identifies four main areas in Danish sea territory
suitable for wind power with a potential of 8,000 MW. The philosophy behind
the selected areas is simple: For environmental reasons the Committee has
concentrated the capacity in few and remote areas with water depths between
5 and 11 metres.
291
由丹麦电力公司为环境和能源部长起草的报告中确定了丹麦海域适合于风力发
电的四个主要区域,具有 8000兆瓦的储量。这些被选区域背后的道理很简单:
处于环境原因,委员会把这部分容量集中在很少而且偏远的区域,水深在 5到
11米之间。The areas have been selected to avoid national park areas, shipping routes,
microwave links, military areas, etc. The distance from coastal areas varies
from 7 to 40 km. This also minimises the visual impact onshore.
所选的这些区域需要避开国家公园地区、海运路线、微波通道、军事区域等。距离
岸上区域 7到 40千米。这同时使陆上的视觉影响最小。The most recent research into foundations indicates that it may be economic
to install offshore turbines even at 15 metres water depth. This mean that the
offshore potential is some 16,000 MW in the selected areas in the Danish
Waters.
最近对基础的深入研究表明,在 15米水深处安装风机也比较经济。这意味着丹
麦海域所选区域海上储量约为 16000兆瓦。
Foundations at sea 海上基础
Wind Turbine Offshore Foundations 风力机海上基础
292
The major challenge for offshore wind energy is cutting costs: Undersea
cabling and foundations have until recently made offshore wind energy an
expensive option.
海上风能的主要挑战是削减成本:直到目前为止,海底电缆和基础依旧使海上
风能成为一种昂贵的选择。New studies of foundation technology, however, plus megawatt-sized wind
turbines are now on the point of making offshore wind energy competitive with
onshore sites, at least for shallow water depths up to 15 metres (50 ft.).
然而,基础技术加上兆瓦级容量风力机的新研究,现在正在使海上风能具有和
陆上一样的竞争力,至少对于 15米(50英尺)以内的浅水深度。Since offshore wind turbines generally yield 50 per cent higher output than
turbines on nearby onshore sites (on flat land), offshore siting may be quite
attractive, cf. the page on offshore wind conditions
因为海上风力机通常比邻近陆上风场(平地上)风机的输出要高出 50%,因此海
上风场很有吸引力,参见海上风力条件一节。Steel is Cheaper Than Concrete 钢比混凝土便宜Two Danish power company groups and three engineering firms made a
pioneering study on the design and costing of offshore wind turbine
foundations in 1996-1997. The report concluded that steel is far more
competitive than concrete for larger offshore wind farms.
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丹麦两个电力集团公司和三个工程公司于 1996-1997年间率先对海上风力机基
础的设计和成本计算进行了研究。报告作出结论,对于更大的海上风电场,钢铁
远比混凝土更有竞争力。It appears that all of the new technologies will be economic until at least 15
metres water depth, and possibly beyond such depths. In any case, the
marginal cost of moving into deeper waters is far smaller than what was
previously estimated.
看起来似乎所有的新技术都是经济的,直到至少 15米水深,并且可能超过这个
深度。无论如何,移动至更深水域的边际成本要远小于之前所估计的。With these concepts foundation and grid connection costs for large 1.5
megawatt turbines are only 10 to 20 per cent higher than the corresponding
costs for the 450-500 kW turbines used at Vindeby and Tunø Knob offshore
wind parks in Denmark.
使用这些概念,大型 1.5兆瓦风力机的基础和并网成本,仅比丹麦 Vindeby 和
Tunoe Knob 海上风电场的 450-500千瓦风力机相应的成本高了 10%到 20%。50 Year Design Lifetime 50年设计寿命Contrary to popular belief, corrosion is not a major concern with offshore steel
structures. Experience from offshore oil rigs has shown that they can be
adequately protected using cathodic (electrical) corrosion protection.
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与流行的观念相反,腐蚀不是海上钢结构关注的主要问题。海上石油钻探平台的
经验表明,使用阴极(电的)腐蚀保护可以充分保护钢结构。Surface protection (paint) on offshore wind turbines will routinely be delivered
with a higher protection class than for onshore turbines.
海上风力机的表面保护(涂料)一般都采取比陆上风力机更好的防护等级。Oil rig foundations are normally built to last 50 years. This is also the design
lifetime for the steel foundations used in these studies.
石油钻探平台的基础一般能够持续 50年。这也就是这些研究中所使用的钢结构
基础的设计寿命。Reference Turbine 参考风机The reference turbine for the study is a modern 1.5 MW three-bladed upwind
turbine with a hub height of about 55 metres (180 ft.) and a rotor diameter of
some 64 metres (210 ft.).
用于研究的参考风机是一台现代的 1.5兆瓦三叶片上风向风力机,其轮毂高度
约为 55米(180英尺),转轮直径约为 64米(210英尺)。The hub height of the reference turbine is low compared with the typical
onshore turbine of that size. In Northern Germany the typical hub height of a
1.5 MW turbine varies from 60 to 80 m (200 to 260 ft.). Because of the very
smooth surface (low roughness) of water surfaces it is cost-efficient to use
lower towers. You may verify these conclusions using the Wind Turbine
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Power Calculator which already has a built in example of a 1.5 MW offshore
wind turbine.
参考风力机的轮毂高度和陆上同样容量的风力机相比偏低。在德国北部,典型的
1.5兆瓦风力机轮毂高度大约为 60到 80米(200到 260英尺)。由于水表面很光
滑(低粗糙度),使用更低的塔架具有成本效益。你可以使用风力机功率计算器证
实这些结论,计算器已经内置了一个 1.5兆瓦海上风力机的实例。
Concrete caissons 混凝土沉箱
Offshore Foundations: Traditional Concrete 海上基础:传统混凝土
Foundation being floated out to Tunoe Knob Photograph © 1996 by Flemming HagensenTunoe Knob的基础正在进行海上卸货,摄影
The first offshore pilot projects in Denmark (and the world) used concrete
gravity caisson foundations.
丹麦第一个海上试验项目(也是世界第一个)使用混凝土重力沉箱基础。As the name indicates, the gravity foundation relies on gravity to keep the
turbine in an upright position.
如名字所示,重力基础依靠重力来使风力机保持在垂直的位置。296
Vindeby and Tunoe Knob Offshore Wind Farms / Vindeby 和 Tunoe Knob 的海上风电场Vindeby Offshore Wind Farm and Tunoe Knob Wind Farm are examples of
this traditional foundation technique. The caisson foundations were built in dry
dock near the sites using reinforced concrete and were floated to their final
destination before being filled with sand and gravel to achieve the necessary
weight. The principle is thus much like that of traditional bridge building.
Vindeby和 Tunoe Knob的海上风电场就是采用这种传统基础技术的实例。在这
两个场址附近的干码头上使用钢筋混凝土建造沉箱基础,在填充沙子和砂砾来
取得需要的重量之前,浮运至其最终的目的地。所以这个原理更像传统的桥梁建
筑。The foundations used at these two sites are conical to act as breakers for
pack ice. This is necessary because solid ice is regularly observed in the
Baltic Sea and the Kattegat during cold winters.
这两个场址使用的基础是圆锥形,可以作为拦截浮冰的阻断器。这很有必要,因为在寒冷的冬天,波罗的海和卡特加特海峡通常可以地看到坚硬的冰块。Disadvantage of Concrete 混凝土的劣势Using traditional concrete foundation techniques the cost of the completed
foundation is approximately proportional with the water depth squared - the
quadratic rule.
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使用传统的混凝土基础技术,基础全部的成本约与水深的平方 -二次方法则成比
例。The water depths at Vindeby and Tunoe Knob vary from 2.5 m to 7.5 m. This
implies that each concrete foundation has an average weight of some 1050
metric tonnes.
Vindeby和 Tunoe Knob的水深在 2.5米至 7.5米间变化。这表明每个混凝土基
础的平均重量约为 1050公吨。According to the quadratic rule the concrete platforms tend to become
prohibitively heavy and expensive to install at water depths above 10 metres.
Therefore, alternative techniques had to be developed in order to break
through the cost barrier, as we shall see on the next pages.
根据这个二次方法则,混凝土平台安装于水深超过 10米时,重量和成本会变得
非常高。因此,为了打破成本障碍,必须开发替代技术,如下一页将看到的。
Steel gravitaty foundations 钢重力基础
Offshore Foundations: Gravitation + Steel 海 上基础:重力+钢铁Most of the existing offshore wind parks use gravitation
foundations. A new technology offers a similar method
to that of the concrete gravity caisson. Instead of
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reinforced concrete it uses a cylindrical steel tube placed on a flat steel box on
the sea bed.
现有的大多数海上风电场使用重力基础。新技术提供了一种类似于混凝土重力沉
箱的方法。该方法使用圆柱型钢管代替钢筋混凝土,将其放置到海床的扁钢箱里Weight Considerations 重量考虑A steel gravity foundation is considerably lighter than concrete foundations.
Although the finished foundation has to have a weight of around 1,000 tonnes,
the steel structure will only weigh some 80 to 100 tonnes for water depths
between 4 and 10 m. (Another 10 tonnes have to be added for structures in
the Baltic Sea, which require pack ice protection).
钢重力基础要比混凝土基础轻很多。尽管完成的基础必须具有约 1000吨的重量
对于水深 4到 10米的情况,钢结构仅有 80到 100吨的重量。(在波罗的海,需
要浮冰保护,因此结构必须增加另外的 10吨,)
The relatively low weight allows barges to transport and install many
foundations rapidly, using the same fairly lightweight crane used for the
erection of the turbines.
相对低的重量允许用船来快速地运输和安装基础,同样使用重量相当轻的起重
机来竖立风力机。The gravity foundations are filled with olivine, a very dense mineral, which
gives the foundations sufficient weight to withstand waves and ice pressure.
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重力基础使用橄榄石填充,很厚重的矿石,使基础具有足够的重量来承受波浪
和浮冰的压力。Size Considerations 尺寸考虑The base of a foundation of this type will be 14 by 14 m (or a diameter of 15 m
for a circular base) for water depths from 4 to 10 m. (Calculation based on a
wind turbine with a rotor diameter of 65 m).
这种类型基础的底座对于水深 4到 10米,会是 14 乘 14(或者是直径 15米的圆
形底座)。(基于具有 65米转轮直径的风力机来计算)。Seabed Preparation 海床处理The advantage of the steel caisson solution is that the foundation can be
made onshore, and may be used on all types of seabed although seabed
preparations are required. Silt has to be removed and a smooth horizontal
bed of shingles has to be prepared by divers before the foundation can be
placed on the site.
钢沉箱方案的优势是能够在岸上制造基础,可以用于所有类型的海床,尽管需
要海床处理。在基础放置在场址之前,必须由潜水员清除淤泥、准备出一个平滑
水平的面板床。Erosion Protection 腐蚀保护The seabed around the base of the foundation will normally have to be
protected against erosion by placing boulders or rocks around the edges of
the base. This is, of course, also the case for the concrete version of the
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gravitation foundation. This makes the foundation type relatively costlier in
areas with significant erosion.
基础底座周围的海床,通常必须在底座边缘周围放置石头或岩石,进行抗腐蚀
保护。对于混凝土版的重力基础,情况也是这样。这使得腐蚀较重区域的基础相
对昂贵。Costs by Water Depth for Steel Gravitational Foundations 钢重力结构成本与水深的关系
The cost penalty of moving to larger water
depths is minimal compared to traditional
concrete foundations. The reason is, that the
foundation base does not have to increase in
size proportion to the water depth to lean
against ice pressure or waves.
相对于传统混凝土基础,移动至更大水深的成
本代价很小。原因是基础底座不必随水深来成比例地增大尺寸,以应对浮冰压力
和波浪。The cost estimates for this type of foundation is for instance 2,343,000 DKK (=
335,000 USD) for a 1.5 MW machine placed at 8 m water depth in the Baltic
Sea (1997 figures). The costs include installation.
这种类型基础的成本评估,例如对立于波罗的海水深 8米处的 1.5MW风机,是
2,343,000 丹麦克朗(DKK)(= 335,000 美元(USD))(1997年数字)。
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The graph shows how the cost varies with water depth. Interestingly, the
dimensioning factor (which decides the required strength and weight of the
foundation) is not the turbine itself but ice and wave pressure forces.
曲线图显示了成本如何随水深变化。有意思的是,尺寸因素 (决定了基础需要的
强度和重量)不是风力机本身,而是浮冰和波浪的压力。
Monopile foundations 单桩基础
Offshore Foundations: Mono Pile 海上基础:单桩The mono pile foundation is a simple construction. The foundation consists of
a steel pile with a diameter of between 3.5 and 4.5 metres. The pile is driven
some 10 to 20 metres into the seabed depending on the type of underground.
The mono pile foundation is effectively extending the turbine tower under
water and into the seabed.
单桩基础是一种简单的建筑。基础有一个直径 3.5到 4.5米之间的钢桩构成。钢
桩插进海床约 10到 20米,这取决于地下的类型。单桩基础有效地将风力机塔架
延伸到水下及海床内。An important advantage of this foundation is that no preparations of the
seabed are necessary. On the other hand, it requires heavy duty piling
equipment, and the foundation type is not suitable for locations with many
large boulders in the seabed. If a large boulder is encountered during piling, it
is possible to drill down to the boulder and blast it with explosives.
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这种基础一个重要的优点是不需整理海床。另一方面,它需要重型打桩设备,而
且这种基础类型不适合海床内有很多大卵石的位置。如果在打桩过程中遇到一块
大卵石,可能在石头上向下钻孔并用炸药将之炸开。Costs by Water Depth for Mono Pile Foundations 单桩基础成本与水深的关系The dimensioning factor of the foundation
varies from the North Sea to the Baltic Sea.
In the North Sea it is the wave size that
determines the dimension of the mono pile.
In the Baltic Sea the pack ice pressure
decides the size of the foundation. This is
the reason why the mono pile foundation
cost increases more rapidly in the Baltic Sea than in the North Sea. The costs
include installation (1997 prices).
北海和波罗的海的基础尺寸因素是不同的。在北海波浪的大小决定了单桩的尺寸
在波罗的海,浮冰的压力约定了基础的尺寸。这是为什么单桩基础成本在波罗的
海比在北海增加更快的原因。成本包括安装(1997年价格)。Erosion Considerations 腐蚀的考虑Erosion will normally not be a problem with this type of foundation.
腐蚀对于这种类型的基础,通常不是问题。Swedish Offshore Project 瑞典海上项目
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A 2.5 MW pilot project with five Danish wind turbines using the mono pile
technology has been installed in the Baltic sea south of the Swedish island of
Gotland.
一个 2.5MW的试验项目,具有使用单桩技术的 5个丹麦式风力机,已经安装在
瑞典哥特兰岛的波罗的海南部。Using the mono pile foundation technique at Gotland involved drilling a hole of
8 to 10 metres depth for each of the turbines (Wind World 500 kW). Each
steel pile is slotted into the the solid rock. When the foundations are in place
the turbines can be bolted on top of the mono piles.
哥特兰岛使用单桩基础技术,每个风力机均涉及钻 8到 10米深的孔。每个钢桩
安置进坚固的石头。当基础就位后,风力机可以用螺栓固定在单桩的顶部。The whole operation takes about 35 days under average Baltic weather
conditions.
在波罗的海的平均气候条件下,整个操作花费了约 35天。
Tripod foundations 三脚架基础
Offshore Foundations: Tripod 海上基础:三角架
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Image © 1997 Ramboll图象The tripod foundation draws on the experiences with light weight and cost
efficient three-legged steel jackets for marginal offshore fields in the oil
industry.
三脚架基础从石油工业海上边际油田中吸取了一些经验,采用了重量轻、价格合
算的三脚钢套管。From a steel pile below the turbine tower emanates a steel frame which
transfers the forces from the tower into three steel piles. The three piles are
driven 10 to 20 metres into the seabed depending on soil conditions and ice
loads.
从风力机塔架下面的一个钢桩发出一个钢框架,把塔架的应力传递到三个钢桩。
三个桩打进海床 10到 20米,这取决于土壤条件和冰冻荷载。Advantages of the Tripod 三脚架的优势The advantage of the three-legged model is that it is suitable for larger water
depths. At the same time only a minimum of preparations are required at the
site before installation.
三腿模型的优势是适合于更大的水深。同时,安装前在场址仅需要较少的准备。
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Multi-pile technology 多桩技术The foundation is anchored into the seabed using a relatively small steel pile
(0.9 m diameter) in each corner. Because of the piling requirement, the tripod
foundation is not suited for locations with many large boulders.
基础固定进海床内,在每个角使用相对小的钢桩(0.9米直径)。由于打桩的需要,
三脚架基础不适合有很多大卵石的地方。Erosion Considerations 腐蚀的考虑Erosion will normally not be a problem with this type of foundation.
腐蚀对于这种类型的基础,通常不是问题。Suitable for Larger Water Depths 适合于更大水深This type of foundation is not suitable at water depths lower than 6-7 metres.
The main reason for this is that service vessels at low water depths will face
problems approaching the foundation due to the steel frame.
这种类型的基础不适合水深低于 6-7米的地方。对此的主要原因是浅水处的服务
船只由于钢结构而面临接近基础的问题。Cost by Water Depth for Tripod Foundations 三脚架基础成本和水深的关系
As in previous page, the basic difference
between costs in the North Sea and the
Baltic Sea is that waves determine
dimensioning in the North Sea, whereas ice
is decisive in the Baltic Sea. The costs
include installation (1997 prices).
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如前一页,北海和波罗的海成本间的基本差别是,在北海波浪决定尺寸,而在
波罗的海浮冰是决定性的。成本包括安装(1997年的价格)。
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Electrical grid 电网
Variations in energy 能量变化
Wind Turbines in the Electrical Grid: Wind Energy Variations
电网中的风力机:风能变化The vast majority of the installed power of wind turbines in the world is grid
connected, i.e. the turbines feed their electricity directly into the public
electrical grid.
世界上已安装的风力机绝大多数是接入电网的,即,风力机将其发出的电能直
接馈入公共电网。Wind Energy Production During a Fine Summer Week 在一个天气适宜的夏天风能的一周发电量
Wind presently covers about 20 per cent of the electricity consumption in the Western part of Denmark.The ELSAM electricity supply area comprises the Western part of Denmark with the Jutland Peninsula and the neighbouring island of Fyn. The area has a population of 3 million
风能目前覆盖了丹麦西部电力消耗的大约 20%。ELSAM 供电区域包括丹麦的西
部、日德兰半岛以及 Fny的临近岛屿。这些区域有三百万人口。The graph above shows
a summer week of
electricity output from the
650 MW (megawatts) of
wind turbines installed in
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the Western part of Denmark. The blue curve at the top left shows the power
output on 25 June 1997, while the orange curve shows the output the
preceding day.
上图显示了安装在丹麦西部的 650MW(兆瓦)风力机在夏天一周的电能输出。左
上角的蓝色曲线显示了 1997年 6月 25日的电能输出,橘红色的曲线显示了前
一天的输出。Electrical power consumption was 2,700 MW at the time this curve was
printed from the power company control centre. Wind was supplying 270 MW
i.e. wind was supplying exactly 10 per cent of the electricity consumption of 3
million people at 13:45 hours when we visited the control centre.
当时的电力消耗是 2,700兆瓦,这条曲线是从电力公司的控制中心打印出来的。
风能提供了 270兆瓦,即,当我们在下午 13点 45分参观控制中心的时候,风
力发电刚好为三百万人口提供了 10%的电量。Wind Matches Daily Electricity Consumption Patterns 风能匹配于日常电力消耗模式At the bottom of the graph you can see the power output of the five preceding
days. On average, the month of June has the lowest wind power output during
the year in Denmark. Some days of fresh winds, however, began in the early
morning hours of 24 June.
在图片的底部,你能看见在此之前五天的电能输出。平均来说,在丹麦六月是风
能输出最低的月份。然而,一些风力充沛的日子是从 6月 24日的清晨开始的。
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The typical weather pattern is that winds are low at night, and higher during
the day, as you can see from the five days of moderate winds.
典型的天气模式是晚上风力小,白天风力更大,正如你在风力平稳的五天里看
到的那样。This means that wind electricity generally fits well into the electricity
consumption pattern, i.e. wind electricity tends to be more valuable to the
electrical grid systems than if it were being produced at a random level.
这意味着风电一般能很好地适合电力消耗模式,即,与风电的随机性发电相比,
风电对电网来说也趋于更有价值。
Seasonal variations 季节性变化
Seasonal Variation in Wind Energy 风能的季节性变化
Wind Matches Seasonal Electricity Consumption Patterns 风能匹配于季节性电力消耗模式
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In temperate zones summer winds are generally weak compared to winter
winds. Electricity consumption is generally higher in winter than in summer in
these regions.
在温带地区,夏季的风一般比冬季的风更为微弱。而这些地区的电能消耗一般是
冬季比夏季更高。In the cooler areas of the globe, electrical heating is therefore ideal in
combination with wind energy, because the cooling of houses varies with the
wind speed much like the electricity production of wind turbines vary with wind
speeds.
因此在地球更寒冷的地区,电力供暖结合风能将非常理想,因为房屋降温随风
速的变化关系与风力机的发电量随风速的变化非常相似。In electricity systems that are not based on hydropower and wind there may
be good reasons to avoid electrical heating, however:
然而,在并非基于水电和风电的电力系统里,避免采用电力供暖有很好的理由:Conventional power plant wastes a lot of heat, and thus fuel (at least 60%),
i.e. for every unit of useful heat consumed by a household, the power station
will waste 1.5 units of heat (and fuel).
常规发电站浪费了大量热量,也浪费了燃料(至少 60%),即,对于一个家庭
消耗的每一有用的热量单位来说,电站将浪费 1.5个热量单位(和燃料)。Annual Variation in Wind Energy 风能的年度变化
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Just like harvest yields vary from year to year in agriculture, you will find that
wind patters may vary from year to year. Typically, the variations are less than
the changes in agricultural production. In the case of Denmark, you will see
that output from wind turbines typically have a variation (a standard deviation)
of some 9 to 10 per cent. You may see the monthly and yearly variations in
Denmark during more than 20 years on the web site Vindstyrke.
就像农业的收成随年份变化一样,你会发现风力也是随年份而变化。典型地,这
种变化要比农业生产的变化小。以丹麦为例,你会发现风力机的输出通常有约
9%到 10%的变化(标准偏差)。你可以从网站 Vindstyrke 上看到丹麦 20年以
上的月度和年度风能变化数据。
Power quality 电能质量
Wind Turbines and Power Quality Issues 风力机和电能质量问题The buyer of a wind turbine does not need to concern himself with local
technical regulations for wind turbines and other equipment connected to the
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electrical grid. This responsibility is generally left to the turbine manufacturer
and the local power company.
风力机的购买者没有必要去考虑当地对接入电网的风力机和其他设备的技术规
定。这个责任一般留给风力机制造商和当地的电力公司。For the people who are technically minded, we go into some of the
electrotechnical issues involved in connecting a turbine to the grid on this
page.
对于那些留意技术的人,我们将在这一页讨论一些涉及到风力机接入电网的电
气技术问题。Power Quality 电能质量
The term "power quality" refers to the voltage stability, frequency stability, and
the absence of various forms of electrical noise (e.g. flicker or harmonic
distortion) on the electrical grid. More broadly speaking, power companies
(and their customers) prefer an alternating current with a nice sinusoidal
shape, such as the one in the image above. (If you are not familiar with the
basics of alternating current (AC) it may be useful to consult the Reference
Manual about this subject before continuing).
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“电能质量”的术语是指电网的电压稳定性、频率稳定性以及尽可能少的各种形
式的电力噪声(例如闪变与谐波畸变)。更广义地说,电力公司(及其用户)更
喜欢具有良好正弦形态的交流电,如上图所示。(如果你对交流电(AC)的基础
不熟悉,在继续阅读之前查阅参考手册会很有用)。Starting (and Stopping) a Turbine启动(停止)风机Most electronic wind turbine controllers are programmed to let the turbine run
idle without grid connection at low wind speeds. (If it were grid connected at
low wind speeds, it would in fact run as a motor, as you can read about on the
generator page). Once the wind becomes powerful enough to turn the rotor
and generator at their rated speed, it is important that the turbine generator
becomes connected to the electrical grid at the right moment.
大多数风力机电子控制器编入的程序,是使风力机在低风速时空载运行而不并
入电网。(如果风力机在低风速下并入电网,它会实际上作为电动机运行,如在
关于发电机一节中读到的)。一旦风力变得足够强劲,使转轮和发电机以其额定
转速转动,此时将风力发电机接入电网是十分重要的。Otherwise there will be only the mechanical resistance in the gearbox and
generator to prevent the rotor from accelerating, and eventually overspeeding.
(There are several safety devices, including fail-safe brakes, in case the
correct start procedure fails, which you may have read in the section on Wind
Turbine Safety).
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否则在齿轮箱和发电机中,只有机械阻力来阻止转轮加速,最终会导致转速过
高。(有几种安全设备,包括失效安全刹车,以防正确的启动过程失败,这部分
的内容你可能已经在风力机安全章节中读到过)。Soft Starting with Thyristors晶闸管的软启动If you switched a large wind turbine on to the grid with a normal switch, the
neighbours would see a brownout (because of the current required to
magnetise the generator) followed by a power peak due to the generator
current surging into the grid. You may see the situation in the drawing in the
accompanying browser window, where you see the flickering of the lamp
when you operate the switch to start the wind turbine. The same effect can
possibly be seen when you switch on your computer, and the transformer in
its power supply all of a sudden becomes magnetised.
如果你使用普通开关来投切电网上的大型风力机,临近用户将会看到一个电压
跌落(因为发电机需要电流来励磁),随之是发电机电流涌入电网造成的功率峰
值。你可以在相应浏览窗口的图形上看到这一现象,当你操作开关来启动风力机
时,你会看到电灯的闪烁。同样的效果当你打开电脑时也可能看到,电源端的变
压器会在一瞬间被励磁。Another unpleasant side effect of using a "hard" switch would be to put a lot of
extra wear on the gearbox, since the
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cut-in of the generator would work as if you all of a sudden slammed on the
mechanical brake of the turbine.
使用“硬”开关的另一个缺点是将会导致齿轮箱大量的额外损耗,因为发电机
的切入会起作用,正如你突然合上风力机的机械刹车时一样。
Large power thyristors in wind turbines get very hot when they are activated. They have to be equipped with aluminium heat sinks and fans as you see in the picture to the right.
风力机使用的大功率晶闸管在工作时会变得很热。它们必须配备铝散热器和风扇
如右侧图中所示。Photograph Soren Krohn 摄影 Soren Krohn© 1998 DWIA
To prevent this situation, modern wind turbines are soft starting, i.e. they
connect and disconnect gradually to the grid using thyristors, a type of
semiconductor continuous switches which may be controlled electronically.
(You may in fact have a thyristor in your own home, if you own a modern light
dimmer, where you can adjust the voltage on your lamps continuously).
为了防止这种情况出现,现代风力机采用软启动,即,使用晶闸管逐渐与电网
连接或断开,晶闸管是一种可以电子控制的半导体连续开关。 (实际上你可能自
己家就有晶闸管,如果你有一个现代的灯光调光器,它可以持续地调节灯的电
压)。
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Thyristors waste about 1 to 2 per cent of the energy running through them.
Modern wind turbines are therefore normally equipped with a so called bypass
switch, i.e. a mechanical switch which is activated after the turbine has been
soft started. In this way the amount of energy wasted will be minimised.
晶闸管会浪费大约 1%到 2%通过他们的能量。现代风力机因此通常装备所谓的
旁路开关,即,在风力机完成软启动之后触发一个机械开关。用这种方式,浪费
的能量被降到最低。Weak Grids, Grid Reinforcement 弱电网,电网扩容If a turbine is connected to a weak electrical grid, (i.e. it is vary far away in a
remote corner of the electrical grid with a low power-carrying ability), there
may be some brownout / power surge problems of the sort mentioned above.
In such cases it may be necessary to reinforce the grid, in order to carry the
fluctuating current from the wind turbine.
如果风力机接入弱电网,(即,在距离电网很远的偏远角落变化,功率支持能力
较弱),上面所提类型可能会有一些电力不足/功率浪涌问题。这种状况下有必要
加强电网,来支撑风力机产生的波动电流。Your local power company has experience in dealing with these potential
problems, because they are the exact mirror-image of connecting a large
electricity user, (e.g. a factory with large electrical motors) to the grid.
本地的电力公司具有处理这些潜在问题的经验,因为它们是大型电力用户 (例如,
拥有大型电动机的工厂)接入电网的确定镜像。317
Flicker 闪变Flicker is an engineering expression for short lived voltage variations in the
electrical grid which may cause light bulbs to flicker. This phenomenon may
be relevant if a wind turbine is connected to a weak grid, since short-lived
wind variations will cause variations in power output. There are various ways
of dealing with this issue in the design of the turbine, mechanically,
electrically, and using power electronics.
闪变是电网中短时电压变化的工程表达,可能会造成灯泡闪烁。这一现象可能与
风力机接入弱电网有关,因为短时风力变化会造成功率输出的变动。有很多风力
机设计方法来应对这一问题,从机械上、电气上以及使用电力电子装置。Preventing "Islanding" 防止“孤岛效应”Islanding is a situation which may occur if a section of the electrical grid
becomes disconnected from the main electrical grid, e.g. because of
accidental or intended tripping of a large circuit breaker in the grid (e.g. due to
lightning strikes or short circuits in the grid). If wind turbines keep on running
in the isolated part of the grid, then it is very likely that the two separate grids
will not be in phase after a short while.
孤岛效应是一种可能发生的情况,如果电网的一部分与主电网之间断开连接,
例如电网中大型断路器意外或有意跳闸(例如由于电网中的雷击或短路)。如果风
力机在电网的隔离部分持续运行,则很有可能一小段时间之后,两个分离的电
网不再同相。
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Once the connection to the main grid is re-established it may cause huge
current surges in the grid and the wind turbine generator. It would also cause
a large release of energy in the mechanical drive train (i.e. the shafts, the gear
box and the rotor of the wind turbine) much like "hard switching" the turbine
generator onto the grid would do.
一旦重新建立与电网的连接,可能会在电网和风力发电机内造成具大的浪涌电
流。同时也会造成机械传动链(即轴、齿轮箱和风力机转轮)巨大的能量释放,与
风力机“硬投切”至电网时的现象很相似。The electronic controller of the wind turbine will therefore constantly have to
monitor the voltage and frequency of the alternating current in the grid. In
case the voltage or frequency of the local grid drift outside certain limits within
a fraction of a second, the turbine will automatically disconnect from the grid,
and stop itself immediately afterwards. (Normally by activating the
aerodynamic brakes as explained in the section on wind turbine safety).
因此风力机的电子控制器必须持续地监测电网交流电的电压和频率。如果当地电
网的电压和频率在若干分之一秒内偏离限值,风力机会自动断开与电网的连接,
之后立即停机。(通常触发气动刹车,如风力机安全章节中所解释的)。
Offshore wind and grid 海上风力和电网
Grid Connection of Offshore Wind Parks 海上风电场的并网
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The Grid 电网The picture to the right shows the Danish electrical transmission grid. Major
power stations are shown in yellow.
右侧图片显示了丹麦输电网。主要电站以黄色显示。Total generating capacity was some 10,000 MW in 1998.
1998年总发电容量约为 10000兆瓦。Present and future offshore wind parks with a total of some 4,100 MW are
shown in white and blue.
当前和未来的海上风电场总量约为 4100兆瓦,以白色和蓝色显示。The western and eastern part of the country are not directly connected, but
are connected to the German and Swedish electrical transmission systems
using AC (alternating currency transmission lines). The rest of the
connections to Sweden, Norway, and Germany are DC (direct current)
connections.
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丹麦西部和东部的电网没有直接并网,而是采用交流输电线 (AC)方式并入德国
和瑞典的输电系统。其它风电场与瑞典、挪威和德国的联网采用直流(DC)方式。Grid connection of offshore wind parks is not a major technical problem per se
, in the sense that the technologies which are involved are well known.
Optimising these technologies for remote offshore sites will be important,
however, to ensure reasonable economics.
海上风电场的并网本身并不是一个主要的技术问题,所涉及的技术人所共知。然
而为了确保合理的经济性,对偏远海上场址的技术进行优化非常重要。The first commercial-sized offshore wind farms in Denmark - Horns Rev and
Nysted - are located 10-20 km (6-12 miles) from shore, at water depths from 6
to 14 metres. The wind farms are 160 MW (Horns Rev) and 158 MW (Nysted)
and they consist of respectively 2 MW and 2.2 MW wind turbines.
丹麦第一批商业化海上风电场- Horns Rev和 Nysted-位于距离海岸 10-20千米
的海域,水深 6 到 14 米。这些风电场是 160 兆瓦 (Horns Rev)和 158 兆瓦
(Nysted),分别由 2兆瓦和 2.2兆瓦风力机构成。Cabling 铺设电缆Undersea cabling connecting offshore parks to the main electrical grid is a
well known technology. Undersea cables will have to be buried in order to
reduce the risk of damage due to fishing equipment, anchors, etc. If bottom
conditions permit, it will be most economic to wash cables into the seabed
(using high pressure water jets) rather than digging or ploughing cables into
the bottom of the sea.
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海上风电场通过铺设海底电缆与主电网并联,这是众所周知的技术。为了减少由
于捕鱼工具、锚等对海底电缆造成破坏的风险,海底电缆必须埋起来。如果底部
条件允许的话,把电缆冲入海床(使用高压喷水器)是最经济的,而不是通过挖
掘或犁耕把电缆置入海床。Voltages 电压Within the offshore wind farm of Horns Rev a 36 kV connection is used. In the
middle of the wind farm, there is a platform with a 36-150 kV transformer
station, as well as a number of service facilities, like a helicopter platform.
Horns Rev海上风电场内部使用 36千伏连接。在风电场的中间,有一个平台,
具有 36-150千伏变电站,以及大量的服务设施,例如直升机平台。A 150 kV connection is used to transport the electricity to the shore.
使用 150千伏连接将电能传送至岸上。Reactive Power, HVDC 无功功率,高压直流输电(HVDC)
The undersea cables will have a high electrical capacitance, which may be
useful to supply reactive power to the parks. It may be optimal to have some
form of variable reactive power compensation built into the system, depending
on the precise grid configuration. If the distance to the main grid is
considerable, an interesting alternative could be to connect the parks to the
mainland using high voltage direct current connections (HVDC).
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海底电缆具有很大的电容,有利于向风场提供无功功率。在系统内建设可变的无
功功率补偿方式可能是最佳的,这取决于精确地电网配置。如果距离主电网相当
远,一种值得关注的可选方法是使用高压直流输电(HVDC)将风场连接至大陆。( Reactive Power is related to phase-shifting of alternating current, which makes it more difficult to transport usable energy through the electrical grid. See the Reference Manual on this web site for the technical details.)(无功功率与交流电的相移有关,使通过电网传送有用的能量变得更加困难。技
术细节见本网站的参考手册。)Remote Surveillance 远程监控Remote surveillance of the parks is even more important offshore than on
land. Radio links for this purpose have been in operation at the Tunoe Knob
and Vindeby offshore wind farms for some years. At Horns Rev, the control
centre is connected to each wind turbines via fibre-optics cables.
海上风电场的远程监控确实比陆上更加重要。为此目的而使用的无线电通讯已经
在 Tunoe Knob和 Vindeby的海上风电场运行了数年。在Horns Rev海上风电场
控制中心通过光纤电缆与每个风力机相连接。The large wind turbines make it cost-effective to install e.g. extra sensors on
each piece of equipment, (and continuously analyse its minute vibrations
which tend to change pattern as the part is worn down). This technology is
well known in the industry to ensure optimum maintenance of machinery.
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大型风力机使在每件设备上安装例如额外的传感器更具有经济效益, (持续地分
析其微小振动,往往随着部件的磨损而改变模式)。这种技术在工业界广为所知,
可以保证机器得到最佳的维护。Preventive Maintenance 预防性维护Since weather conditions may prevent service personnel from approaching
the wind turbines at times of bad weather, it is extremely important to ensure
a high availability rate of offshore wind turbines. Preventive maintenance
check programmes may need to be optimised for remote offshore locations。
因为有时候恶劣的天气条件可能会阻止服务人员接近风力机,因此保证海上风
力机的高可靠性显得极其重要。对于偏远海上位置,需要对预防性维护检查程序
进行优化。
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Environment环境
Landscape and turbines 景观与风力机
Wind Turbines and the Environment: Landscape 风力机与环境 :景观Hints About Landscape Architecture and Wind Turbine
风力机与景观的关系
Photograph Søren Krohn© 1999 DWIA
摄影 Søren Krohn
© 1999 DWIA
Wind turbines are always highly visible elements in the landscape. Otherwise they are
not located properly from a meteorological point of view, cf. the page on wind turbine
siting.
风力机往往是景观中一种非常显眼的元素。否则从气象角度来看,风力机的位置
将显得很不合适,请参照风力机选址一节。The image to the left shows the wind farm at Kappel, Denmark. It is perhaps the most
aesthetically pleasing layout of any wind farm known to this author. The shape of the
dike along the coastline is repeated in the line of turbines.
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左侧图片为丹麦 Kappel风力发电场。这也许是作者所见过的最漂亮最令人愉悦
的风电场布局了。风力机沿着海岸线一字排开。There is one disturbing element in the picture above: The single turbine next to the
farmhouse, which interrupts the otherwise smooth pattern of turbines. (That turbine
was there before the wind farm was built).
上面图中有一个瑕疵:与农家相邻的一台单独的风力机打破了其他风力机的平
滑格局。(这台风力机是早于风电场建好的)。
Simple Geometrical Patterns简单几何图案In flat areas it is often a good idea to place turbines in a simple geometrical pattern
which is easily perceived by the viewer. Turbines placed equidistantly in a straight
line work well, but the example in the picture above may be even more elegant, where
landscape contours invite such a solution.
在平原地区把风力机排列成一个简单图案,这是一个绝妙的主意,因为这样很
容易被大家接受和理解。风力机等距放置在一条直线上是一种很好的运行方案,
但上图示例中的图案更为优雅,是景观轮廓的最好方案。There are limits to the usefulness of being dogmatic about using simple geometrical
patterns, however:
然而,教条地使用简单的几何图案会有一些限制:
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In hilly landscapes it is rarely feasible to use a simple pattern, and it usually works
better to the the turbines follow the altitude contours of the landscape, or the fencing
or other characteristic features of the landscape.
在丘陵地貌中,使用简单的图案是不可行的,通常风力机沿着景观的纬度轮廓,
或者景观的栅栏或其它特征性地貌,工作会更好。Whenever turbines are placed in several rows, one will rarely be able to perceive the
pattern when the park is viewed from normal eye level. Only when one is standing at
the end of a row, does it really appear as an ordered layout. In the next panorama
picture, you will probably only be able to discern three rows of turbines, while the rest
appear to be scattered around the landscape.
只要风力机以若干排放置,当从正常视觉水平观察风场时,很少能够察觉到这
种图案。只有站在一排的末端,才会实在地呈现出有序的布局。在下面的全景图
片中,你可能只能看出三排风力机,其余的看起来散落在地貌周围。
Photograph © 1997 Suzanne Clemmesen
摄影© 1997 Suzanne Clemmesen
Light Grey Paint
浅灰色涂料The picture above shows one of the larger groupings of Danish built wind turbines at
Näsudden on the island of Gotland in Sweden. The grey paint on the turbines make
them blend well into the landscape.
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上面图片显示了一家丹麦大型集团公司在瑞典哥特兰岛的Näsudden 建立的风力
机。风力机上的灰色涂料使它们更好地融入到景观中。
Size of Wind Turbines 风力机的尺寸Large wind turbines enable the same amount of energy to be produced with fewer
wind turbines. There may be economic advantages to this, such as lower maintenance
costs.
大型风力机能够用更少数量的风机产出同样多的能量。这可能会有经济优势,例
如更低的维护成本。From an aesthetic point of view, large wind turbines may be an advantage in the
landscape, because they generally have lower rotational speed than smaller turbines.
Large turbines therefore do not attract the eye the way fast-moving objects generally
do.
从美学角度看,大型风力机可能在景观上具有优势,因为他们通常比小风力机
旋转速度慢。因此,大型风力机不会像快速运动的物体那样吸引注意力,。People's Perception of Wind Turbines in the Landscape
人们从景观角度对风力机的认识To a large extent it is a matter of taste how people perceive that wind turbines fit into
the landscape.
人们对于风力机是否适合景观的认识,在很大程度上是一个品味问题。Numerous studies in Denmark, the UK, Germany, and the Netherlands have revealed
that people who live near wind turbines are generally more favourable towards them
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than city dwellers. You may find more details about these studies in the article Public
Attitudes Toward Wind Power on this web site.
丹麦、英国、德国和荷兰的许多研究表明,住在风力机附近的人通常比城市居民
更加喜爱它们。你可以在此网站公众对于风电的态度一文中找到关于这些研究的
更多细节。A beautiful book of photographic examples of Wind Turbines in the Landscape may
be purchased from Birk Nielsens Tegnestue, Aarhus, Denmark. The price is
approximately 150 DKK, plus postage.
你可以从丹麦奥尔胡斯的 Birk Nielsens Tegnestue 买到一本漂亮的关于风力机景
观图例的书。价格大约是 150丹麦克朗,另加邮费。
Aerial markings 航空 标志
3D Visualisation of Aviation Obstruction Markings on Wind Turbines
风力机的三维可视化航空障碍物标志Wind turbines have grown considerably in size over the
past 20 years. In 1980 the average size wind turbine had
a rotor diameter of 10.5 metres - today there are many
wind turbines with rotor diameters of more than 80
metres, roughly 25% larger than the wingspan of a
Boeing 747.
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过去 20多年里,风力机的尺寸有了相当大的增长。1980年,风力机平均尺寸的
转轮直径为 10.5米-现在很多风力机的转轮直径超过 80米,大概比波音 747的
机翼还要大 25%。
Consequently, an increasing number of wind turbines exceed the 100 m (300 ft.) limit
of height for when obstruction marking may be required by the aviation authorities.
The first time in Denmark was in 1999, when six 2 MW turbines were erected at
Hagesholm on Zealand.
因此,当越来越多的风力机超过 100米(300英尺)的高度限制时,民航当局要
求设置障碍物标志。在丹麦第一次是 1999年,当 6台 2兆瓦的风力机竖立在西
兰岛Hagesholm时。According to Danish aviation regulations on obstruction marking, constructions of
less than 100 metres tall are not marked, whereas constructions taller than 150 metres
are always marked. For constructions which are between 100 and 150 metres tall the
Danish Civil Aviation Administration passes judgement on a case-by-case basis
whether, and if so, how a construction must be marked.
根据丹麦关于障碍物标志的航空条例,低于 100米的建筑物不用设置标志,但
是高于 150米的建筑物必须设置标志。对于 100至 150米之间的建筑,丹麦民航
局在逐项的基础上判断是否需要,以及如果需要的话如何在建筑物上设置。330
Virtual reality image by Uni-C利用 Uni-C 软件制作的模拟真实场景
How Should Wind Turbines be Marked? 风力机应该如何设置标志?Danish authorities, wind turbine manufacturers and project developers began to
seriously address the question of how to mark wind turbines with a total height of
above 100 metres in 2000 during the planning phase for the two first large scale
Danish offshore wind farms. The two 160 MW wind parks were erected in 2002 and
2003 respectively, at Horns Rev in the North Sea and off the Nysted coast of the
island Lolland.
2000年在丹麦最初 2个大型海上风电场的规划阶段,丹麦政府、风力机制造
商以及项目开发商开始认真地讨论如何在总高度超过 100米的风力机上设置标
志。这两个 160兆瓦的风电场分别建立于 2002年和 2003年,位于北海的 Horns
Rev和洛兰岛的Nysted海岸以外。It was clear from the outset that obstruction marking of wind turbines with a total
height of above 100 metres is a balancing act between a number of different
considerations. On the one hand, defence authorities require clear obstruction
markings justified by the need for military training exercises as well as rescue
operations. On the other hand, the envirnomental authorities want obstruction
markings which are disturbance-free to nature and neighbours.
从一开始就很清楚,总高度超过 100米的风力机的障碍物标志,是一些不同考
虑因素之间的平衡。一方面,防卫当局要求设置清晰的障碍物标志,理由是军事
训练和救援行动的需要;另一方面,环保局希望障碍物标志不会对自然界和邻
居产生干扰。331
The consulting engineering firms behind the Horns Rev and Nysted projects thus had
a pressing need to get clarification on how the two first large offshore wind farms in
the world were to be marked. The Danish wind turbine manufacturers wished to assist
in resolving the question in particular in regard to making clear regulations and
realistic demand specifications for light emission intensity and pulse frequency. At the
same time, it was deemed important to find solutions friendly to the eye and the
neighbouring environment.
因此,Horns Rev和 Nysted 项目背后的工程咨询公司有了一个紧迫的需要,就
是弄清楚如何为这两个世界上最早的大型海上风电场设置标志。丹麦的风力机制
造商愿意协助解决问题,特别是关于制定光照强度和脉冲频率方面的明确规定
和现实需求说明。同时,发现对视觉和周围环境友好的解决方案被认为非常重要Accordingly, the Danish Wind Industry Association and the two consulting
engineering firms in the autumn of 2000 initiated a 3D-visualisation project:
Visualisation of Obstruction Lights on Wind Turbines. The project obtained 1 million
DKK (135 ,000 EUR) in support from the Public Service Obligation fund controlled
by Eltra, one of the Danish transmission system operators.
因此在 2000年秋,丹麦风力工业协会和两个工程咨询公司发起的一个三维可视
化项目:风力机障碍物灯的可视化。该项目从 Eltra控制的公共服务基金获得 1
百万丹麦克朗(135000欧元)的支持,Eltra是丹麦输电运营商之一。The concept "Public Service Obligation" in this case covers the legal obligation for
the transmission system operator to conduct or fund research which is of importance
to society in the TSO's field of responsibility.
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在这种情况下,“公共服务义务”概念列入输电运营商(TSO)的责任条款,输电
运营商具有法定义务来引导和资助对于社会很重要的研究项目。
Why 3D Visualisation? 为什么是三维可视化?The immediate objective of the project was to develop a so-called wind turbine
configurator, which may be used to visualise a predetermined wind farm with
different types of obstruction lights of varying colour and intensity. The resulting
configurations can then be visualised from different angles and distances as well as
under different weather and light conditions.
项目的直接目的是开发所谓的风力机配置器,通过配置器来使规划中的风电场
实现可视化,风电场使用颜色和强度可变的不同类型的障碍物灯。然后作为结果
的配置能够从不同的角度和距离以及在不同的天气和灯光条件下实现可视化。An advanced visualisation tool seemed to be the appropriate solution to get a realistic
picture enabling evaluation of visibility of different markings as well as of their
environmental impact. Firstly, it can be used to visualise new wind farms before they
are erected. Secondly, it is much cheaper to visualise different solutions than to mount
different models on existing wind farms and conduct military fly-by exercises.
一个先进的可视化工具似乎是得到一张现实图片的合适解决方案,这张图片能
评估不同标志的能见度及其对环境的影响。首先,它可以在新的风电场建设之前
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对其进行可视化。其次,得到不同的可视化方案比在已经建好的风电场安装不同
的模型和举办军事飞行训练更加便宜。As such the visualization tool will be useful to balance the debate between different
authorities and actors. Ultimately the tool will help find the most appropriate solution
for obstruction marking of wind turbines.
因为这样的可视化工具对于平衡不同机构和参与者之间的争论非常有用。最终,
这个工具将会帮助找到风力机障碍物标志的最合适的解决方案。
Nysted CaseNysted案例A Danish software company was given the task to
develop the necessary 3D software in collaboration with
the project participants. The final visualisation software
comprises a number of modules: A wind turbine module, a light emission module, and
a wind farm module. In addition, the software can handle a landscape database, e.g.
the sea, a coastline or a location on land.
一家丹麦软件公司受命与项目参与者协作开发所需要的 3D 软件。最终的可视化
软件包括很多模块:风力机模块、光照模块和风电场模块。另外,软件可处理地
貌数据库,例如海、海岸线或者陆上位置。The project used Nysted Offshore Wind Farm south of Lolland as a case for its model.
The offshore farm will be connected to the grid in 2003.
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项目在其模型中使用洛兰岛南部的Nysted海上风电场作为一个案例。这个海上
风电场将在 2003年接入电网。Nysted Offshore Wind Farm will consist of 72 wind turbines, each having a rated
power of 2.2 MW. The hub height is 68.8 m (226 ft), the rotor diameter is 82.4 m (270
ft). Maximum tip height is therefore 110 m (361 ft).
Nysted海上风电场将有 72台风力机组成,每台的额定容量为 2.2兆瓦。轮毂高
度为 68.8米(226英尺),转轮直径为 82.4米(270英尺)。因此最大叶尖高度
为 110米(361英尺)。The offshore farm will be laid out as 8 rows of 9 turbines - the closest some 10
kilometres off shore. The 72 wind turbines have an production equivalent to the
consumption of 110.000 Danish households.
这个海上风电场将布局 8 排,每排 9台风力机-最近的离海岸约 10千米。72台风
力机发出的电能等同于 110,000户丹麦家庭的电力消耗。
Video clips from the Project 项目的视频剪辑The most realistic visualisation viewing is achieved in 3D on a large screen in a
virtual reality centre. This is particularly important with regard to reproduction of
light, as the impression of light is subjective to the viewing situation. A lighted wind
farm is much more visible to the eye if viewed at night from a dark beach than if
viewed from a lighted city street. In a VR centre, adjustments can be made to
compensate from these factors.
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最现实的可视化观察是在一个虚拟现实中心的大屏幕上以三维(3D)形式获得的。
其中关于灯光的复现尤其重要,因为灯光效果受观察位置的支配。如果夜里从昏
暗的海滩观察有灯标的风电场,比从明亮的城市街道观察更加明显。在VR中心
可以进行调整来补偿这些因素。The visualisation programme and the Nysted case has on several occasions been
projected in a VR centre for an audience of authorities and other potential users. As
such the programme has provided input to the ongoing debate.
在 VR中心,可视化程序和 Nysted案例已经在几个场合为各机构和潜在用户的
观众放映了投影。同样地程序也为正在进行的讨论提供了输入。If you view the video clip from a computer screen instead, the necessary adjustments
cannot be made. The simulation quality will depend greatly on the light intensity of
the screen, light falling onto the screen, etc. Furthermore, the comparatively smaller
size of the screen obviously also compromises the quality. The simulation is therefore
far less realistic than on a computer screen than in a VR centre.
如果你改为从计算机屏幕观看录象剪辑,就不用做必要的调整。模拟质量将极大
地取决于屏幕的光强度、落在屏幕上的灯光等。此外,相对更小尺寸的屏幕也会
明显损害质量。因此,在电脑屏幕上模拟远没有在VR中心更加现实。The video clips (3 minutes, 3 MB in QuickTime) show the solutions which were
finally adopted for the Horns Rev and Nysted-Rødsand projects, plus some solutions
which were not accepted. Click the image below to see the movie.
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录象剪辑(3分钟,QuickTime中的 3MB)显示了 Horns Rev和 Nysted-Rødsand 项
目最终采用的解决方案,以及没有被接受的一些方案。点击下面的图象来观看录
像。The movie will be available in English in July. The link below points to the Danish
version.
英文版录像在 7月份可用。下面的链接是丹麦语版本。
Sound from turbines 风力机的声音
Sound from Wind Turbines 风力机的声音Noise is a Minor Problem Today 目前噪声是个小问题It is interesting to note that the sound emission levels for all new Danish turbine
designs tend to cluster around the same values. This seems to indicate that the gains
due to new designs of e.g. quieter rotor blade tips are spent in slightly increasing the
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tip speed (the wind speed measured at the tip of the rotor blade), and thus increasing
the energy output from the machines.
值得关注的一件有趣的事情是,所有新丹麦风力机设计的声音发射水平都趋于
密集在同一个数值。这似乎表明了新设计例如转轮更安静的叶片叶尖所带来的收
益,轻微地增大了叶尖速度(在转轮叶片叶尖上测量的风速),并且因此增大了
电机的能量输出。In the guided tour section on Wind Turbine Design we have explained how turbines
today are engineered to reduce sound emissions.
在关于风力机设计的指导章节,我们已经解释了目前如何设计风力机以减少声
音发射。It thus appears that noise is not a major problem for the industry, given the distance to
the closest neighbours (usually a minimum distance of about 7 rotor diameters or 300
m = 1000 ft. is observed).
因此看起来噪声对于工业界不是一个主要问题,假设到最近邻居的距离(通常观
测的最小距离大约是 7个转轮直径或 300米=1000英尺)。The concepts of sound perception and measurement are not widely known in the
public, but they are fairly easy to understand, once you get to grips with it. You can
actually do the calculations yourself in a moment.
338
声音感知和测量的概念并不广为所知,一旦你开始掌握的话,但是它们非常容
易理解。事实上你可以立刻自己来做计算。Planning Wind Turbine Installation in Regard to Sound
涉及声音的风力机安装规划
Fortunately, it is usually reasonably easy to predict the sound effect from wind
turbines in advance. On one of the following pages you may even try for yourself,
using the Sound Map Calculator, which was used to draw the picture.
幸运的是,提前预测风力机声音的影响通常相当容易。在下面的任何一页中,你
甚至可以自己尝试使用声音图计算器,来画出图片。Each square measures 43 by 43 metres, corresponding to one rotor diameter. The
bright red areas are the areas with high sound intensity, above 55 dB(A). The dashed
areas indicate areas with sound levels above 45 dB(A), which will normally not be
used for housing etc. (We get to the explanation of the sound level and dB(A) in a
moment).
339
每一个方格测量 43 乘 43米的区域,与转轮直径相对应。明亮的红色区域是高声
音强度的区域,在 55dB(A)以上。虚线区域表示音量在 45dB(A)以上的区域,通
常不用于居住(我们立刻开始解释音量及 dB(A))。As you can see, the zone affected by sound extends only a few rotor diameters'
distance from the machine.
可以看到,被声音影响的地带仅扩展至距离风机几个转轮直径的地方。Background Noise: Masking Noise Drowns out Turbine Noise
背景噪声:掩蔽噪声压过了风力机噪声No landscape is ever completely quiet. Birds and human activities emit sound, and at
winds speeds around 4-7 m/s and up the noise from the wind in leaves, shrubs, trees,
masts etc. will gradually mask (drown out) any potential sound from e.g. wind
turbines.
没有景观是完全安静的。鸟类和人类活动发出声音,以及当风速在 4-7米/秒附近
及以上时来自风吹过树叶、灌木、树、桅杆等的噪音,将逐渐盖过任何可能的声
音,例如来自风力机的声音。This makes it extremely difficult to measure sound from wind turbines accurately. At
wind speeds around 8 m/s and above, it generally becomes a quite abstruse issue to
discuss sound emissions from modern wind turbines, since background noise will
generally mask any turbine noise completely.
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这使得准确地测量风力机的声音变得非常困难。当风速在 8米/秒附近及以上时,
讨论现代风力机的发声一般会变成一个非常深奥的问题,因为背景噪声一般会
完全压过任何风力机的噪声。The Influence of the Surroundings on Sound Propagation
周围环境对声音传播的影响Sound reflection or absorption from terrain and building surfaces may make the sound
picture different in different locations. Generally, very little sound is heard upwind of
wind turbines. The wind rose is therefore important to chart the potential dispersion of
sound in different directions.
声音从地形和建筑物表面的反射和吸收,可能使声音图因位置的不同而不同。通
常,风力机的声音是很少能够迎风向听到的。因此风玫瑰图对于绘制声音在不同
方向可能的传播很重要。
Human Perception of Sound and Noise 人们对声音和噪声的感知Most people find it pleasant listen to the sound of waves at the seashore, and quite a
few of us are annoyed with the noise from the neighbour's radio, even though the
actual sound level may be far lower.
大多数人发现在海滨听波浪的声音很愉悦,相当多的人会因为邻居家的收音机
而烦恼,即使实际的音量可能相当低。Apart from the question of your neighbour's taste in music, there is obviously a
difference in terms of information content. Sea waves emit random "white" noise,
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while you neighbour's radio has some systematic content which your brain cannot
avoid discerning and analysing. If you generally dislike your neighbour you will no
doubt be even more annoyed with the noise. Sound experts for lack of a better
definition define "noise" as "unwanted sound".
除了你的邻居音乐品味的问题外,还明显有信息内容的差异。海浪发出随机的
“白”噪声,而你邻居的收音机有一些系统内容,你的大脑不可避免地要辩识
和分析。如果你通常不喜欢你的邻居,毫无疑问将对其噪声更加烦恼。声音专家
因为缺乏更好的定义而把“噪声”定义为“不需要的声音”。Since the distinction between noise and sound is a highly psychological phenomenon,
it is not easy to make a simple and universally satisfactory modelling of sound
phenomena. In fact, a recent study done by the Danish research institute DK Teknik
seems to indicate that people's perception of noise from wind turbines is governed
more by their attitude to the source of the noise, rather than the actual noise itself.
因为噪声和声音之间的差别是非常心理化的现象,实现声音现象的简单和普遍
满意的建模是不容易的。实际上,最近丹麦研究所DK Teknik 完成的一项研究似
乎表明,人们对风力机噪声的感知更多地被他们对噪声源的态度所支配,而不
是真实的噪声本身。
Sound measurement 声音测量
Measuring and Calculating Sound Levels 测量和计算音量342
The dB(A) Scale dB(A)尺度Public authorities around the world use the so-called dB(A), or decibel (A), scale to
quantify sound measurement. To give you an idea of the scale, look at the table
below.
世界范围的公共机构都使用所谓的 dB (A)或者分贝(A)尺度来量化声音测量。为
了给你尺度的概念,请看下表。Sound Level
Threshold of Hearing
Whisper Talking City Traffic Rock
Concert Jet Engine 10
m Away dB(A) 0 30 60 90 120 150
音量 听觉下限 耳语 谈话 城市交通 摇滚音乐会 10米远的喷气式发动机
dB(A) 0 30 60 90 120 150
The dB(A) scale measures the sound intensity over the whole range of different
audible frequencies (different pitches), and then it uses a weighing scheme which
accounts for the fact that the human ear has a different sensitivity to each different
sound frequency. Generally, we hear better at medium (speech range) frequencies
than at low or high frequencies. The dB(A) system says, that the sound pressure at the
most audible frequencies are to be multiplied by high numbers while the less audible
frequencies are multiplied by low numbers, and everything is then added up to get an
index number.
dB(A)尺度测量不同可听声整个频率范围内的声音强度(不同音高),然后使用一
个加权方案,说明人耳对每个不同声音频率具有不同的敏感度。通常,我们在中
频段(说话音域)比在低或高频段听得更好。dB(A)系统表示,大多数可听声频率
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的声压乘以大的数字,而少数可听声频率乘以小的数字,然后每一个加起来得
到一个指数数字。(The (A) weighing scheme is used for weak sounds, such as wind turbines. There
exist other weighing schemes for loud sounds called (B) and (C), although they are
rarely used).
((A)加权方案用于微弱的声音,如风力机。也存在其他用于高声的加权方案
称为(B)和(C),虽然它们很少使用。)The dB-scale is a logarithmic, or relative scale. This means, that as you double the
sound pressure (or the energy in the sound) the index increases by approximately 3. A
sound level of 100 dB(A) thus contains twice the energy of a sound level of 97 dB(A).
The reason for measuring sound this way is that our ears (and minds) perceive sound
in terms of the logarithm of the sound pressure, rather than the sound pressure itself.
dB-尺度是一个对数,或相对尺度。这意味着当声压(或声音中的能量)加倍,
指数增大约 3倍。因此,一个 100dB(A)音量包含的能量是 97dB(A)的两倍。
用这种方式测量声音的原因是,我们的耳朵(和头脑)根据声压的对数来察觉
声音,而不是声压本身。Most people will say, that if you increase the dB(A) by 10, you double the subjective
loudness of the sound.
大多数人会说,如果你增加 10分贝(A),会使声音的主观响度加倍。
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In case you are interested in the exact definitions, take a look at the Reference Manual
on Acoustics of this web site.
如果你对准确的定义有兴趣,看一看这个网站上的声学参考手册。Sound Propagation and Distance: Inverse Square Law
声音的传播与距离:平方反比定律The energy in sound waves (and thus the sound
intensity) will drop with the square of the
distance to the sound source. In other words, if
you move 200 m away from a wind turbine, the
sound level will generally be one quarter of
what it is 100 m away. A doubling of your
distance will thus make the dB(A) level drop by
6.
声波能量(继之声强)随与声源之间距离的平方而下降。换句话说,如果远离风
力机移动 200米,音量一般会是 100米距离的四分之一。因此距离的加倍会使分
dB(A)水平下降 6倍。At one rotor diameter distance (43 m) from the base of a wind turbine emitting 100
dB(A) you will generally have a sound level of 55-60 dB(A) corresponding to a
(European) clothes dryer. 4 rotor diameters (170 m) away you will have 44 dB(A),
corresponding to a quiet living room in a house. 6 rotor diameters (260 m) away you
will have some 40 dB(A).
距离风力机底座一个转轮直径(43米)的地方发出 100dB(A)的音量,对应一个
(欧洲产)干衣机一般将有 55-60dB(A)的音量。4个转轮直径(170米)处有345
44dB(A),相当于在房间里安静的起居室。6个转轮直径(260米)处有大约
40dB(A)。The precise relationship between sound level and distance from the sound source is
given in a table on the Reference Manual on Acoustics of this web site.
音量和与声源距离之间的确切关系,在此网站声学参考手册的一个表中给出。In practice, sound absorption and reflection (from soft or hard surfaces) may play a
role on a particular site, and may modify the results shown here.
实际上,声音的吸收和反射(从软或硬表面)可能在特定位置起作用,并可能
更改这里显示的结果。Adding Sounds from Several Sources
几个声源中声音的叠加If we have two wind turbines rather than one, located at the same distance from our
ears, naturally the sound energy reaching us will double. As we have just learned, this
means that two turbines will increase the sound level by 3 dB(A). Four turbines
instead of one (at the same distance) will increase the sound level by 6 dB(A). You
will actually need ten turbines placed at the same distance from you, in order to
perceive that the subjective loudness has doubled (i.e. the dB level has increased by
10).
如果我们有两个风力机而不是一个,位于与我们耳朵距离相同的地方,自然达
到我们的声音能量也将加倍。正如我们刚刚学到的,这意味着两个风力机将增加
3dB(A)的音量。四个风力机代替一个(在同样的距离)将增大 6dB(A)的音346
量。事实上,为了感知主观响度已经加倍(即 dB水平已经增加了 10倍),需要
10台风力机放置在与你距离相同处。If you wish to learn the details about adding sounds together, take a look at the
Reference Manual on Acoustics in this web site.
如果你希望了解有关声音叠加在一起的细节,看一看本网站的声学参考手册。
The Pure Tone Penalty纯音惩罚The fact that the human ear (and mind) discerns pure tones more easily than (random)
white noise, means the authorities may wish to take that into account when doing
sound estimates. They consequently often have rules which specify that you add a
certain number to the dB(A) figure in case you have pure tones present in a sound.
人耳(和头脑)辨识纯音比白(随机)噪声更加容易的事实,意味着相关机构可
能希望在进行声音评估时予以考虑。因此往往有规则详细说明了万一声音呈现出
纯音调,可以在 dB(A)数字中增加一定的量。Wind Turbine Noise Information in Practice
实际中的风力机噪声信息In accordance with international standards manufacturers generally specify a
theoretical dB(A) level for sound emissions which assumes that all sound originates
from a central point, although in practice, of course, it will originate from the whole
surface of the machine and its rotor.
347
按照国际标准,制造商一般会规定一个发声的理论 dB(A)水平,假定所有声音
起源于一个中心点,当然,尽管实际上声音将源于整个电机表面及其转轮。Sound pressure thus calculated is typically around 96-101 dB(A) for modern wind
turbines. The figure itself is rather uninteresting, since there will not be a single point,
where you can experience that sound level! Rather, it is useful for predicting the
sound level at different distances from the wind turbine.
因此,现代风力机典型的计算声压大约是 96-101dB(A)。这个数字本身相当无趣,
因为没有一个单独的点,可以让你体验那个音量!相反,它对于预测风力机不
同距离处的音量很有用。Pure tones have generally be eradicated completely for modern wind turbines, at least
in the case of the modern turbines listed in the catalogue on the Wind Power
Calculator page.
现代风力机中,纯音一般被完全根除了,至少对于风力发电计算 页面 目录中所
列的现代风力机上是这种情况。Legal Noise Limits
法定噪声限制At distances above 300 m the maximum theoretical noise level from high quality wind
turbines will generally be significantly below 45 dB(A) outdoors, corresponding to
the legislation in Denmark. (For built-up areas with several houses, a noise limit of 40
dB(A) is the legal limit in Denmark).
348
对应丹麦的法律规定,户外距离在 300米以上,高品质风力机的理论噪音水平
一般将大大低于 45dB(A)。(对于有几栋房屋的建设区,40dB(A)噪声限值
是丹麦的法定限值)。Noise regulations vary from country to country. In practice the same machine designs
can be used everywhere.
不同国家有不同的噪声规定。实际上,同样的电机设计可以用于任何地方。
Current Practice: Calculations Rather than Measurement通用习惯:计算而不是测量Calculating potential sound emission from wind turbines is generally important in
order to obtain planning permission (from the public authorities) for installing wind
turbines in densely populated areas.
为了获得在人口密集区建立风力机的规划许可(从公共机构),计算风力机可
能发射的声音一般很重要。Generally speaking, it is far easier to calculate the potential sound emissions than to
measure them in practice.
一般来说,计算可能发射的声音要比实际测量容易得多。The reason why it is difficult to measure the sound is that the sound level has to be
some 10 dB(A) above the background noise in order to measure it properly. The
background noise from leaves, birds, and traffic will frequently be above 30 dB(A),
however. In most places in the world public authorities therefore rely on calculations
rather than measurements, when granting planning permission for wind turbines.
349
难以测量声 音的原因是,为了正确测量它,音量必 须高于背景噪声大约
10dB(A)。然而,这些来自于树叶、鸟类和交通的背景噪音常常在 30dB(A)以
上。因此当准予风力机规划许可时,世界上大多数地方的公共机构依靠计算而不
是测量。
Sound map calculator 声音 图 计算器
Sound Map Calculator for Wind Turbines 风力机的声音图计算器
Sound Levels Around Wind Turbines
风力机周围的音量Sound levels outside dashed areas are 45 dB(A) or less.
虚线区域以外的音量是 45dB(A)或更低301 m >= 55 dB(A) = 258 m 50-54 dB(A) = 215 m 45-49 dB(A) = 172 m 40-44 dB(A) = 129 m 35-39 dB(A) = 86 m 30-34 dB(A) = 43 m --- 29 dB(A) = 0 m
-43 m -86 m
-129 m -172 m -215 m -258 m -301 m -344 m No. of turbines = 3
风力机数量=3
350
Source sound levels in dB(A)= 100, 100, 100,
声源音量的 dB(A)=100100100
© Copyright 1998 Danish Wind Industry Association
© Copyright 1998 丹麦风力工业协会Do not operate the form until this page and its programme have loaded completely,
and the picture has appeared in the frame.
在本页面及其程序完全下载、并且图片已经出现在框架上之前,不要操作表格。Click in grid to insert or remove turbines. Point with mouse to read sound level in
dB(A) in your browser's status line. Source sound level for next turbine is set to
dB(A), Grid unit size is set to m. (It is convenient to use the rotor
diameter as your grid size when placing turbines). Maximum permissible sound level
at houses is set to dB(A). This grid has grid points each way. You may
use a grid with up to 32 points if you have a fast computer with enough memory
allocated for Netscape. If you change a number, press the tab key, click
CALCULATE, or click outside the field you just entered to start calculations and plot.
Click CLEAR to delete the turbines and reset to default data.
点击网格来插入或删除风力机。用鼠标点读浏览器中状态行的 dB(A)音量。下
一个风力机的声源音量设置为 100dB(A),网格宽度尺寸设置为 43米。(当放
置风力机时,使用转轮直径作为网格大小非常方便)。房屋内可允许的最大音量
设置为 45dB(A)。这个网络每一路有 16个网格点。如果你有一台Netscape分配的
具有足够内存的快速计算机的话,你可使用多达 32个点的网格。如果你改变一351
个数字,按下 tab键,点击计算、或者点击你刚才进入的区域外边,开始计算和
绘图。点击清除键,删除风力机和复位到默认数据。To print the results of the Sound Map Calculator you should make a screen dump
要打印声音图计算器的结果,你应该进行屏幕转存。
Sound calculator 声音计算器
Wind Turbine Sound Calculator风力机声音计算器Do not operate the form until this page and its programme have loaded completely.
在本页面及其程序完全下载之前,不要操作表格。TurbineSource dB(A)
Distance m Resulting dB(A)Sound Level
Sound PowerW/m2
1 100 300 39.465 0.00000000882 100 250 41.049 0.0000000127345678910Sum= 43.339 0.0000000216
Calculate Reset
风力机声源 dB(A)
距离 m
结果 dB(A)
音量声音功率W/m2
1 100 300 39.465 0.0000000088352
2 100 250 41.049 0.0000000127345678910
总 和=
43.339 0.0000000216
计算 复位You may enter source noise and distance for up to ten wind turbines in the worksheet
below to calculate the resulting sound at a particular point. The calculator assumes
that sound absorption and reflection cancel one another out, although local noise
regulations may specify rules for this. You should have read the pages on Sound from
Wind Turbines and Measuring and Calculating Sound Levels before using the
calculator. You may learn more about the technical details of sound calculations in the
Reference Manual on Acoustics.
在下面的工作表中,你可以输入多达 10台风力机的声源噪声和距离,来计算特
定点上产生的声音。这个计算器假设吸收和反射互相抵消,尽管当地的噪音规定
可能对此详细说明了规则。在使用计算器之前,你应该已经阅读了关于风力机的
声音、测 量和计 算音量 的内容。你可以从声学参考手册中学习更多有关声音计算
的技术细节。
353
Energy balance 能量平衡
Energy Payback Period for Wind Turbines
风力机的回收周期Two to Three Months Required
需要 2到 3个月Modern wind turbines rapidly recover all the energy spent in manufacturing,
installing, maintaining, and finally scrapping them. Under normal wind conditions it
takes between two and three months for a turbine to recover all of the energy
involved.
现代风力机能够迅速地收回所有在制造、安装、维护中消耗的能量,并最终超过
它们。在正常的风力条件下,一台风力机需要两到三个月就能收回全部相关的能
量。This is one of the main results of a life cycle analysis of wind turbines done by the
Danish Wind Industry Association.
这是由丹麦风力工业协会完成的风力机生命周期分析的主要成果之一。The study includes the energy content in all components of a wind turbine, and it
includes the global energy content in all links of the production chain.
这项研究包括风力机所有组件的能量含量,而且包括生产链全部环节的全球能
源含量。You may download the 16 page report.
354
你可以下载 16页的报告Input Output Analysis Method
输入输出分析方法To find the results, the study employs a so called input output model of the Danish
economy published by the Danish Central Bureau of Statistics. The input output
model divides the economy into 117 sub sectors, and accounts for the flows of 27
different energy goods (fuels etc.) between the 117 sectors.
为了发现这一结果,研究采用了由丹麦中央统计局发布的所谓的丹麦经济输入
输出模型。输入输出模型把经济分为 117个子部分,并说明了 27种不同能源商
品(燃料等)在 117个部分中的流程。The basic advantage of using this method instead of engineering calculations, is that
we are able to account properly for the amount of energy used by producers of
components and manufacturing equipment, buildings etc. in all links of the production
chain. The result is a large 117 by 117 table of energy flows. (Doing a mathematical
operation on the table called matrix inversion we obtain the amount of energy per
dollar of output).
使用这种方法代替工程计算的基本优点是,我们能够准确地说明生产链所有环
节中组件、制造设备和建筑等的制造者所使用的能量数量。其结果是一张很大的
117 乘 117的能量流程表。(在称为矩阵求逆的表上进行数学运算,可以获得每
美元输出的能量数量)。The Energy Balance for Offshore Wind Turbines
355
海上风力机的能量平衡Offshore wind turbines may have a slightly more favourable energy balance than
onshore turbines, depending on local wind conditions. In Denmark and the
Netherlands, where wind turbines onshore are typically placed in flat terrain, offshore
wind turbines will generally yield some 50 per cent more energy than a turbine placed
on a nearby onshore site. The reason is the low roughness of the sea surface.
海上风力机可能略微比陆上风力机具有更有利的能量平衡,这取决于当地的风
力条件。在丹麦和荷兰,陆上风力机通常安装在平坦的地形,海上风力机产出的
能量一般比安置在附近岸上的风力机多 50%。原因是海洋表面的粗糙度较低。On the other hand, the construction and installation of foundations require 50 per cent
more energy than onshore turbines.
另一方面,基础建设和安装需要的能量要比陆上风力机多 50%。It should be remembered, however, that offshore wind turbines have a longer
expected lifetime than onshore turbines, in the region of 25 to 30 years. The reason is
that the low turbulence at sea gives lower fatigue loads on the wind turbines.
然而应该记住,海上风力机比陆上风力机具有更长的预期寿命,在 25至 30年
之间。原因是海洋的低湍流使得风力机的疲劳载荷更低。
Analysis of 1980 Vintage Turbines 1980年老式风力机的分析1980 wind turbines do surprisingly well in the studies of the energy balance. The
analysis shows that while small Danish 1980 turbines of 10-30 kW took almost a year
to recover the energy spent in manufacturing, installing and decommissioning them,
turbines of 55 kW took some 6 months to recover all of the energy. 356
1980的风力机在能源平衡的研究中做得出奇的好。分析显示,虽然丹麦 1980年
的 10-30千瓦小型风力机用了几乎一年的时间收回制造、安装和报废所消耗的能
量,但是 55千瓦风力机用了大约 6个月收回了全部的能量。
Birds and wind turbines 鸟 类 和风力机
Birds and Wind Turbines 鸟类和风力机Common Eider (Somateria Mollissima) Photograph Søren Krohn © 1996 DWIA
绒鸭 (Somateria Mollissima) 摄影 Søren Krohn
© 1996 DWIA
Birds often collide with high voltage overhead lines, masts, poles, and windows of
buildings. They are also killed by cars in the traffic.
鸟类经常会与高压架空线路、桅杆、天线和建筑物的窗户碰撞。它们还经常在交
通中被车撞死。Birds are seldom bothered by wind turbines, however. Radar studies from Tjaereborg
in the western part of Denmark, where a 2 megawatt wind turbine with 60 metre rotor
diameter is installed, show that birds - by day or night - tend to change their flight
route some 100-200 metres before the turbine and pass above the turbine at a safe
distance.
然而,鸟类很少被风力机打扰。在丹麦西部的 Tjaereborg,安装了一台具有 60米
转轮直径的 2MW风力机,此处的雷达研究表明鸟类-无论白天还是黑夜-往往是357
在距离风力机 100-200米之前改变他们的飞行路线,在风力机上面以安全的距
离通过。In Denmark there are several examples of birds (falcons) nesting in cages mounted on
wind turbine towers.
在丹麦,有几个鸟类(猎鹰)把巢穴安置在风力机塔架上的例子。The only known site with bird collision problems is located in the Altamont Pass in
California. Even there, collisions are not common, but they are of extra concern
because the species involved are protected by law.
唯一知名的发生鸟类相撞问题的地点,位于加利福尼亚的Altamont Pass。即使在
那里,碰撞也不常见,但是它们受到了额外的关注,因为牵涉的物种是受法律
保护的。A study from the Danish Ministry of the Environment says that power lines, including
power lines leading to wind farms, are a much greater danger to birds than the wind
turbines themselves.
来自丹麦环境部的一份研究表示电力线路,包括通向风电场电力线路,对鸟类
来说比风力机本身更加危险。Some birds get accustomed to wind turbines very quickly, others take a somewhat
longer time. The possibilities of erecting wind farms next to bird sanctuaries therefore
depend on the species in question. Migratory routes of birds will usually be taken into
account when siting wind farms, although bird studies from Yukon, Canada, show
358
that migratory birds do not collide with wind turbines (Canadian Wind Energy
Association Conference, 1997).
一些鸟类很快就习惯了风力机,另外的需要稍微长点的时间。因此,在鸟类保护
区附近竖立风电场的可能性取决于正在讨论的物种。风电场的选址通常会考虑鸟
类的迁徙路线,尽管加拿大 Yukon的鸟类研究显示,候鸟没有与风力机碰撞
(加拿大风能协会会议,1997年)。
Birds and offshore wind 鸟 类 和海上风 力
Birds and Offshore Wind Turbines 鸟类和海上风力机 Ornithologists' (Bird watchers) tower erected next to the offshore wind farm at Tunø Knob, Denmark, for a three-year avian study which was completed in 1997. Photograph Soren Krohn
鸟类学家(鸟类观察者)的观察塔竖立在丹麦 Tunø Knob海上风电场的旁边,进行了 3年的鸟类研究,完成于 1997年© 1997 DWIA
Offshore wind turbines have no significant effect on water birds. That is the overall
conclusion of a three year offshore bird life study made at the Danish offshore wind
farm Tunø Knob.
359
海上风力机不会对水上鸟类产生重大影响。这是在丹麦 Tunø Knob 海上风电场进
行的一个为期三年的海上鸟类生活研究的总体结论。The offshore wind park has been placed in this particular area because of a very
substantial population of eiders (Somateria mollissima) and a small population of
scoters ( Melanitta nigra ). At Tunø Knob more than 90 per cent of the birds are
eiders, and about 40 per cent of the North Atlantic population of eiders are wintering
in the Danish part of the Kattegat Sea.
海上风电场已经安置在这个特殊的区域,因为有数目很多的绒鸭(欧绒鸭)和少
量的黑凫(黑海番鸭)。在 Tunø Knob,超过 90%的鸟类为绒鸭,大约 40%的北大
西洋绒鸭将在Kattegat海域的丹麦部分过冬。The Studies were conducted by the National Environmental Research Institute at
Kalø, Denmark.
这些研究是由位于丹麦Kalø的国家环境研究所实施的。Eight Different Studies
八个不同的研究The very thorough study consists of both aerial surveys, bird counts from observation
towers, and observations of the spatial distribution of birds at the offshore site as well
as at a similar control site in the same region.
非常彻底的研究既包括航空调查,从观察塔统计的鸟类数量,也包括在海上场
址以及同一地区相似控制场址鸟类空间分布的观察。
360
In the three year period some eight experiments were carried out. The central
experiment was a so called before-after-control-impact study. From a watch tower
placed one kilometre from the turbines and from aeroplanes scientists mapped the
population of eiders the winter before the erection of the turbines and the following
two winters.
在三年周期内大约执行了八个实验。最重要的实验是一个称为前后控制影响的研
究。从一个放置在距离风力机 1千米的观察台上以及飞机上,科学家绘制出冬天
在风力机前的绒鸭数量,接下来的两个冬天也是如此。
Declining Population 数量下降During the three year period the number of Eiders declined by 75 per cent and the
number of scoters declined by more than 90 per cent. But more interestingly, the
population of water birds fell in all of the shoal of the Tunø Knob and not just around
the turbines. This indicated that other factors than the turbines had to be taken into
account.
在三年期间,绒鸭数量减少了 75%,而黑凫的数量下降超过了 90%。但是更有
趣的是,水鸟数目的下降发生在 Tunø Knob所有浅滩,而不只是风力机周围。这
表示其它因素而非风力机,必须予以考虑。At the same time the area was repeatedly surveyed by divers in order to determine
variations in the amount of blue mussels (Mytilus edulis) which the birds prey on.
同时潜水员在该地区进行了反复调查,以确定鸟类捕食的蓝贻贝(紫贻贝)的
数量变化。361
Less Food
较少的食物The amount of blue mussels showed also great natural variation over the three years.
Especially the population of smaller mussels which are the eiders' preferred prey fell
significantly in the three year period. With these findings in mind the scientific group
concluded that the changes in size and composition of the blue mussel population
could explain the variation in the number of eiders before and after the construction of
the wind farm.
蓝贻贝的数量也显示了三年期间自然的巨大变化。特别在三年里,绒鸭喜欢食用
的更小的贻贝数量下降很快。根据这些发现,科学小组推断蓝贻贝尺寸和成分的
改变,可以解释风电场建设前后绒鸭数目的变化。
Safe Distance安全距离Controlled experiments stopping the wind turbines for a certain period has been
performed. In another experiment decoys was used to attract the eiders, which are
very social birds.
受控实验使风力机停止了一段时间,这已经完成。在另一项实验中,使用诱饵来
吸引绒鸭,绒鸭是喜群居的鸟类。The result of the experiment using groups of decoys at different distances from the
wind farm showed that the eiders were reluctant to pass at distances of 100 m or
closer to the turbines.
362
在距离风电场的不同位置处成批使用诱饵的实验结果表明,绒鸭不愿意通过距
风力机 100米处或更近。The on/off experiment showed that there was no detectable effect of revolving rotors
on the abundance of eiders in the area. In fact the eiders - like people - apparently
prefer rotating turbines (but that result was clearly insignificant).
开/关实验表明,旋转的转轮对这个区域绒鸭的数量没有可感知的影响。事实上,
绒鸭-就像人类-明显地喜欢旋转的风力机(但是这个结果显然无关紧要)。The overall conclusion of the final two experiments were that on one hand the eiders
do keep a safe distance to the turbines, but on the other hand they do not get scared
away from their foraging areas by revolving rotors. Also, the eiders showed normal
landing behaviour until 100 m from the turbines.
最后两个实验的总体结论是,一方面绒鸭保持与风力机之间的安全距离,但在
另一方面,它们没有因为旋转的转轮而害怕并远离其采食区域。同样,绒鸭在距
离风力机 100米外显示出正常的降落行为。
Mussels Matter贻贝物The prevalence of eiders in the different zones around
the turbines could be fully accounted for by the
relative abundance of food.
风力机周围不同地带遍布的绒鸭可以完全占有相对丰富的食物。
363
The English edition of this study "Impact Assessment of an Off-shore Wind Park on
Sea Ducks, NERI Technical Report No. 227 1998" is available from NERI, the
National Environmental Research Institute, Denmark.
这项研究的英语版 “海上风电场对海鸭影响的评估,NERI 技术报告 227 号,
1998年”可以从NERI获得,丹麦国家环境研究所。
Shadow casting 投影
Shadow Casting from Wind Turbines风力机的投影
Wind turbines, like other tall structures will cast a shadow on the neighbouring area
when the sun is visible. If you live very close to the wind turbine, it may be annoying
if the rotor blades chop the sunlight, causing a flickering (blinking) effect while the
rotor is in motion.
当太阳可见时,风力机和其它高建筑物一样会在附近区域产生投影。如果居住在
离风力机很近的地方,这可能令人烦恼,因为转轮在运动时,转轮叶片切割阳
光,会造成闪烁(闪光的)效应。364
A bit of careful planning, and the use of good software to plan your wind turbine site
can help you resolve this problem, however. If you know where the potential flicker
effect is of a certain size, you may be able to place the turbines to avoid any major
inconvenience for the neighbours.
然而,一点精心的规划以及使用好的软件来规划风电场的位置,可以帮助你解
决这一问题。如果你知道可能受闪烁影响区域的确定尺寸,你能够在放置风力机
的时候避免对邻居造成任何大的不便。
Few Rules一些规则Shadow casting is generally not regulated explicitly by planning authorities. In
Germany, however, there has been a court case in which the judge tolerated 30 hours
of actual shadow flicker per year at a certain neighbour's property. In the 30 hours, it
appears, one should only include flicker which occur during the hours where the
property is actually used by people (who are awake).
规划局一般没有对投影做出明确规定。然而在德国,有一个法庭案件,法官宽容
了某一邻居地产的每年 30个小时的实际阴影闪烁。30个小时,看来只包括在人
实际使用地产(醒着的)的小时内发生的闪烁。
Predicting Shadow Flicker 预测阴影闪烁Fortunately, we are able to predict quite accurately the probability of when and for
how long there may be a flicker effect. We may not know in advance whether there is
wind, or what the wind direction is, but using astronomy and trigonometry we can
compute either a likely, or a "worst case" scenario, i.e. a situation where there is
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always sunshine, when the wind is blowing all the time, and when the wind and the
turbine rotor keep tracking the sun by yawing the turbine exactly as the sun moves.
幸运的是,我们能相当准确地预测,可能有闪烁效应的时间以及持续多久的概
率。我们可能不会提前知道是否有风,或者风向如何,但是利用天文学和三角法
我们可能计算出其中的一个,或者一个“最坏情况”的场面,即总是有日照、所
有时间风都在吹的情况,并且这时风和风力机都保持对太阳的跟踪,风力机随
着太阳移动精确地偏航。Figuring out the exact shape, place, and time of the shadow from a wind turbine
requires a lot of computation, but at least one professional wind software programme
can do this very accurately, even in hilly terrain, and with house windows of any size,
shape, location and inclination facing in any direction. (See the Links page for the
address of wind software companies).
算出风力机阴影的确切形状、位置和时间需要大量计算,但是,甚至在丘陵地带
至少一个专业风力软件程序可以精确地算出具有任意尺寸的房屋窗子、形状、位
置并且面向任何方向倾斜。(风力软件公司地址见链接页)。
Do it Yourself自己去做On one of the following pages we have included another shadow calculator, which
will give you a possibility of computing a shadow map of your particular area in flat
terrain. The calculator gives you a lot of options to produce realistic estimates of
actual shadow casting. Fortunately, you will discover that shadow casting problems
are generally restricted to a few areas close to the turbine. 366
在下面一页中,包含了另一个阴影计算器,为你在平原地形计算特定区域的阴
影图提供了可能性。计算器给了你很多选项,来产生实际投影的现实评估。幸运
的是,你将会发现投影问题一般限于接近风力机的一小片区域。Since the calculation of shadow casting requires lots of computer power, we have
included a number of important general results on the following pages.
由于投影的计算需要很多计算机能力,在以下的页面中,我们将包含许多重要
的通用结论。
Shadow calculation 阴影计算
Calculating Shadows from Wind Turbines计算风力机的阴影Daily Shadow Variation - Worst Case每天阴影变化—最坏的情况
This simulation of shadow casting shows how the
rotor shadow moves (worst case) from sunrise to
sunset on a particular day at a certain location on
the globe. The image is seen directly from above,
with the centre of the wind turbine tower placed at
the tiny black dot in the centre. The shadow
positions are shown for every half hour during the day. Shadows, of course, are long
around sunrise and sunset, and short at noon.
投影仿真显示了,在地球上某一位置的特定一天,转轮阴影从日出到日落如何
移动(最坏的情况)。在上面的图片可以直接看到,风力机塔架中心放置在中间367
的一个小黑点处。一天中阴影位置每半小时显示一次。当然,阴影在日出和日落
时长,在中午时短。This particular set of images was made for 55° Northern latitude for 21 September,
assuming a 43 m rotor diameter on a 50 m tower, using the shadow simulation
programme on this web site.
这是 9月 21日、北纬 55度的特定的图像,假定 43米的转轮直径、50米的塔架,
使用本网站的阴影仿真程序。Doing a worst case simulation we assume that the rotor yaws so as to track the
movement of the sun exactly. This is is equivalent to assuming that the rotor is a solid
balloon (or a Darrieus turbine).
做一个最坏情况的仿真,我们假设转轮偏航,以精确地跟随太阳运动。这相当于
假设转轮是一个实心球(或达里厄 风力机 )Annual and Daily Shadows - Worst Case
每年和每天的阴影—最坏情况Map of maximum (worst case) shadows around a 600 kW wind turbine placed at 55 degrees Northern latitude. The turbine has a 43 m rotor diameter and a 50 m tower. The map is 1200 m wide (East - West) and 750 m in the North - South direction. The map was computed using the Wind Turbine Shadow Calculator on this web site
在北纬 55度放置的 600kW风力机周围的最大(最
坏情况)阴影图。风力机具有 43米转轮直径和 50米的塔架。图形宽 1200米
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(东-西)、南-北方向 750米长。图像的计算使用了本网站上的风力机阴影计算
器。This map shows how shadows are typically distributed around a wind turbine
throughout a year, assuming a worst case direction of the rotor. You will notice a
number of kidney-shaped or bell-shaped areas around the wind turbine in the centre of
the map. Each of the grey areas represents a certain maximum number of minutes of
shadow from the wind turbine rotor. Since this map was computed for 55 degrees
latitude in the Northern hemisphere, there is no shadow South of the turbine.
这张图显示了一年当中,风力机周围的阴影是如何典型地分布,假设转轮处在
最坏情况的方向。在图中间风力机的周围,你会注意到许多肾形或钟表形区域。
每个灰色区域代表了风力机转轮阴影某一最大分钟数。由于这张图片是为北半球
纬度 55度计算的,所以风力机的南面没有阴影。
Timing Shadows阴影时间You will notice from the white lines on the map, that we can easily predict the time of
day when shadows may occur.
你可能注意到图中的白色线条,以此我们可以容易地预测一天中可能发生阴影
的时间。The shadow will e.g. obviously be directly North of the turbine at solar noon, when
the sun reaches its maximum height in the sky. (Solar noon varies a bit during the year
relative to our clocks, but it is fairly close to 12 o' clock, local time).
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中午时阴影明显在风力机的正北侧,这时太阳到达它在天空的最大高度。(一年
中中午相对于我们的时钟有一点变化,但是非常接近当地时间的 12点)
The shadow will be to the bottom left at 4 o'clock in the morning on a summer day, so
shadows to the Southwest are a minor problem in the Northern hemisphere. (The
shadows occur in summer only, and at 4 in the morning most neighbours will be
asleep anyway).
在夏季早晨的 4点钟,阴影会在左下部,因此在北半球西南方向阴影是个小问
题。(阴影仅发生在夏季,而且早上 4点钟的时候大多数邻居都还在睡觉)。The commercial software we referred to earlier will tell you exactly the dates and
times when shadows may occur.
之前我们提到的商业软件,会精确地告诉你阴影可能发生日期和时间。
Better calculations 更好的计算
Refining Shadow Calculations for Wind Turbines
提炼风力机阴影的计算Random Rotor Direction (Random Azimuth)
随机转轮方向(随机方位角)It is very unlikely that the wind and thus the rotor will track the
sun in practice. We may therefore get a more realistic result if
we modify our calculations by assuming that the rotor can assume any position at any
time. In the small picture to the far right you can see a situation where the rotor is
directly facing the sun. The tiny white dot near the bottom right is the centre of the
wind turbine tower.
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实际中,风力和转轮跟踪太阳是不太可能的。因此我们可以得到更现实的结果,
如果我们通过假设转轮可以在任何时间假设任何位置来修改计算。在极右侧的小
图片中,可以看到转轮直接面对太阳的情况。右下角的小白点是风力机塔架的中
心。Now, let us assume that we yaw the rotor out of its position by one degree, take a
snapshot of the shadow image, then yaw it by another degree, take another snapshot
etc., until we have done a full 360 degree turn. Then we overlay all our 360 snapshots,
and what we end up with will look similar to the small image to the left: The centre
will get the most of the shadow, but as we move towards the outer edge (where the
vertical edges of the rotor disc cast their shadows) the overall shadow intensity will
decrease.
现在,让我们假设把转轮位置偏航 1度,拍一张阴影图片的快照,然后再偏航 1
度,再拍另外一张快照,如此等等,直到已经旋转了整 360度。然后我们覆盖所
有 360 张快照,最终得到的和左侧的小图相似:中间获得了大部分的阴影,但
是随着我们向外缘(即转轮圆盘垂直边缘投下的阴影)移动,阴影的总体强度
在减小。Shadow casting is on average reduced to 63% of the worst case results, if you assume
a random rotor direction. Ideally, we should have a wind rose, (preferably hourly for
each day or month) to do an exact calculation.
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如果你假设一个随机的转轮方向,投影平均减少到最坏情况的 63%。理想地,我
们应该有一个风玫瑰图,(最好是每天或每月的每小时)来做精确的计算。
Fixed Rotor Direction (Fixed Azimuth) 固定转轮方向(固定方位角)In practice the wind turbine rotor will follow the wind direction
(if the wind speed is above the cut in speed).
事实上,风力机转轮将跟随风力方向(如果风速在切 入 速度
以上)。This image shows the shape of an area (in red) which gives 10 hours or more of
shadows per year at 55° Northern latitude with the rotor yaw ( azimuth ) fixed at an
angle of -45 degrees (i.e. with the wind permanently coming from the Southwest or
Northeast). As you can see, there will be almost no shadows at an angle of +45
degrees, i.e. in the direction parallel to the rotor plane.
这个图片显示了北纬 55度处,每年具有 10小时或更多时间阴影的区域(红色
表示)形状,转轮偏航(方位角)固定在 45度角(即风一直来自于西南或东北
方向)。如你所见,在 45度角,即平行于转轮平面的方向几乎没有阴影。Shadow casting is typically reduced to around 62% of the worst case results, if we
assume a fixed rotor direction.
如果我们假设一个固定的转轮方向,典型地投影会降低至最坏情况的 62%。
Actual Rotor Direction (Wind Rose) 实际转轮方向(风玫瑰图)
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Usually we will already have a wind rose with a frequency distribution of the wind in
the different directions of the compass when we are planning a wind turbine site.
Using that information, we may calculate a more exact shadow picture. In the case of
our test example, Copenhagen, shadows are reduced to some 64 per cent of the
comparable worst case value.
通常当规划一个风力机场址时,我们已经有了风玫瑰图,具有指南针不同方向
上的风力频率分布。利用那个信息,我们可以计算更加精确的阴影图片。在哥本
哈根的测试实例中,和最坏情况的数值比较,阴影减少了大约 64%。
Turbine Operating Hours 风力机运行小时The rotor will not be running all the time, so we may multiply the number of minutes
of shadow flicker by a factor of typically 0.75, depending on the local wind climate,
(and ideally using the correct factor for daytime during each month).
转轮不会在所有时间一直运行,所以我们可以把阴影闪烁的分钟数上乘以一个
因数,典型值为 0.75,取决于当地的风力气候(理想地是每个月使用正确的日
间因数)。
Actual Sunshine Hours实际日照小时When studying shadows, we should only count the fraction of the time when the sun
is actually shining brightly, ideally using the correct fraction for each hour of the day
during the year. In 1853 the first reliable sunshine recording device was invented (and
improved in 1879), which means that in many parts of the world the meteorological
institutes have very accurate long term statistics on the number of hours of bright
sunshine during the year.
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当研究阴影时,我们应该只计算阳光实际明亮照射的那一部分时间,理想地是
使用一年中一天的每一小时的适当部分。1853年第一台可靠的日照记录装置被
发明(1879年改进),这意味着世界许多地区的气象机构,在一年中会有非常
准确的长期日照小时数的统计数据。The number of bright sunshine hours varies with the geographical location and the
season (summer or winter). We have included data for three Danish sites (Christiansø,
Copenhagen, and Viborg) where the number of sunshine hours vary from 44 to 40,
and 36 per cent of the time.
日照小时数随地理位置和季节(夏天或冬天)而变化。我们已经包含了三个丹麦
站点的(Christiansø, Copenhagen和 Viborg)的数据,其日照小时数在 44到 40之
间变化,占时间的 36%。Combining Turbine operating hours, Actual Rotor Direction, and Actual Sunshine Hours
把风力机运行小时,实际转轮方向和实际日照小时结合起来。If we use both turbine operating hours, the actual rotor direction, and the actual bright
sunshine hours we get a result (in the case of Denmark) which is some 18 per cent of
the worst case assumption, using 75% operating hours in both cases. (The percentages
given above are the results of simulations for Copenhagen on a 720 by 720 metre
square with a turbine in the centre with 43 m rotor diameter and 50 m hub height).
如果我们既使用风力机运行小时、实际转轮方向,又使用实际日照小时,就能得
到最坏情况假设的大约 18%的结果(丹麦的情况),在两个案例中使用 75%的374
运行小时。(上面给出的百分数是哥本哈根的仿真结果,720 乘 720米正方形的
中间放置具有 43米转轮直径和 50米轮毂高度的一台风力机)。The two images below compare a worst case simulation (with 75% operating hours)
with an actual simulation for Copenhagen (also 75% operating hours) using both
sunshine and wind statistics. The red area is the zone with 30 hours of shadow or
more per year. Each map represents 720 by 720 metres.
下面的两个图比较了哥本哈根实际仿真中(75%的运行小时)最坏情况的仿真
(也是 75%的运行小时),都使用了日照和风力的统计数据。红色区域是每年具
有 30个小时或以上的阴影的地带。每幅图表示 720 乘 720米的面积。The important conclusion of this simulation is that actual sunshine hours play a very
important role in diminishing the amount of shadows north of the turbine (in the
Northern hemisphere). The reason why this is important is that there are very few
hours of sunshine when the sun is low in the sky to the south during winter.
这一仿真的重要结论是,实际日照小时在减少风力机(在北半球)北边的阴影
上起着非常重要的作用。重要的原因在于,当冬天太阳在天空中很低的时候,日
照小时很少。
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Shadow variations 阴影变化
Shadow Variations from Wind Turbines风力机阴影的变化Monthly Shadow Variation每月的阴影变化
This movie shows the areas affected by shadow casting from a
wind turbine. The movie shows how the area varies month by
month - in this case in relatively high latitudes (55°) in the
Northern hemisphere. The darkest areas represent the areas with most shadows.
这段影片显示了被风力机投影影响的区域。影片显示了阴影区域如何逐月变化-
这是在北半球相对高纬度(55度)的情况。最暗的区域代表了阴影最多的区域。In winter the sun stays in the Southern part of the sky, and the shadows are distributed
in a V-shaped area to the North of the turbine.
在冬天,太阳在天空的南部停留,阴影呈V字形区域分布在风力机的北边。In summer the sun rises very early in the morning to the Northeast and sunset is in the
Northwest. This means that the summer shadows will be distributed in an A-shaped
area, with the turbine in the tip of the "A".
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在夏天,早晨在东北方向的日出很早,日落在西北方向。这意味着夏天的阴影将
会呈A形区域分布,风力机在“A”字形的尖部。In locations closer to the equator there will be far less shadow North and South of the
turbine.
在赤道附近的位置,风力机的北边和南边都很少有阴影。
Shadow Geometry Varies by Latitude 随纬度变化的阴影几何形状
Each latitude on the globe has its own shadow signature in terms of the area affected
by a certain period of shadows from an object (30 hours per year). Close to the
equator the signature resembles a butterfly. Farther away from the equator it becomes
more kidney-shaped, and close to the poles it almost becomes a circle.
地球上的每个纬度都有自己的阴影标志,根据一个物体的阴影在某一时期内影
响的区域(每年 30小时)。赤道附近的标志像一个蝴蝶。远离赤道时,变得更象
肾形,极地附近时几乎变成一个圆形。All of the graphs above were computed using the shadow calculator on this web site,
and assume a "worst case" or a random rotor position.
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以上所有图形均使用本网站上的阴影计算器计算,并假设一个“最坏情况”或
者一个随机转轮位置。
Shadow Size Grows with Rotor Diameter阴影尺寸随转轮直径而增大
The size of the rotor shadow and the number of shadow minutes per year in the
vicinity of the turbine varies in proportion to the rotor area, as shown in the three
pictures above. The red areas indicate the annual shadow patterns with more than 30
hours of shadow (worst case) from wind turbine rotors of 43, 53, and 63 m mounted
on 50 m towers and computed for 55° latitude.
风力机附近的转轮阴影尺寸和每年的阴影分钟数与转轮面积成比例变化,如上
边三幅图片所示。红色区域表示风力机每年的阴影图案,阴影小时超过 30小时,
这些风力机转轮直径分别为 43,53和 63米,安装在 50米高的塔架上,在纬度为
55度的情况下计算。
Hub Height of Minor Importance轮毂高度的微小影响The hub height of a wind turbine is of
minor importance for the shadow from
the rotor. The same shadow will be
spread over a larger area, so in the
vicinity of the turbine, say, up to 1,000
m, the number of minutes per year with
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shadows will actually decrease. The four pictures show shadow casting during a year
(worst case) from a wind turbine with a 43 m rotor diameter, placed with four
different hub heights and computed for 55° latitude. The red areas represent areas
with more than 30 hours of shadows.
风力机的轮毂高度对转轮阴影的影响较小。同样的阴影将分散在一个更大的区域
所以在风力机附近,比如说达到 1000米,阴影每年的分钟数实际上会下降。四
张图片显示了具有 43米转轮直径的风力机在一年中的投影,放置在四个不同的
轮毂高度,在纬度为 55度条件下计算。红色区域代表阴影超过 30小时的区域。If you are farther away from a wind turbine rotor than about 500-1000 metres, the
rotor of a wind turbine will not appear to be chopping the light, but the turbine will be
regarded as an object with the sun behind it. Therefore, it is generally not necessary to
consider shadow casting at such distances.
如果你远离风力机转轮超过大约 500至 1000米,风力机转轮看起来不再切割光
线,但是风力机将被认为是一个有太阳在其后面的物体。因此,一般没有必要考
虑这种距离的投影。
Guide to calculator 计算器指南
Guide to the Wind Turbine Shadow Calculator风力机阴影计算器指南The calculator on the following page allows you to simulate shadows from a wind
turbine on a plane, horizontal landscape any minute, hour, day, month, or year
anywhere on the globe.
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以下网页中的计算器允许你在空中、水平地表仿真风力机的阴影,可以是任何分
钟、小时、天、月或者年,可以在地球的任何地方。Warning: Huge Plots Will Take Their Time - and lots of RAM
警告:大型绘图会花费时间-和许多计算机 RAM
If you wish to compute shadows for a whole year, it may take your computer from 20
minutes to a couple of hours or more, depending on the speed of your browser and
your machine, and how fine a map resolution and time resolution you choose. A fine
map resolution (down to 3 pixels square) or a large plot area increases processing time
and the required amount of RAM on your computer significantly.
如果你希望计算全年的阴影,可能需要你的计算机花费 20分钟到 2个小时或者
更多,这取决于你的浏览器和计算机速度,以及你选择的图像和时间的分辨率
是否良好。好的图像分辨率(下降到像素平方为 3)或者巨大的绘图区域会极大
地增加处理时间和所需要的计算机 RAM量。
Colouring the Plot为绘图着色The grey colours in your plot are selected automatically by the programme, so that the
most shadow affected areas are shown in pure black, while the least affected areas are
shown in white, regardless of whether you run the programme for 1 minute or a year.
The unaffected areas remain green.
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绘图过程中程序会自动选择灰色,所以大多数阴影影响的区域以纯黑色显示,
同时影响最小的区域以白色显示,不管你运行程序 1分钟还是 1年。没有被影响
的区域保持绿色。
Screen Settings 屏幕设置If you have a screen with millions of colours, you will find that the grey shadows vary
very smoothly across the screen. If you like to be able to see the different "bands" of
shadow minute values, like we have done in our images on this web site, set your
monitor to thousands of colours, or even 256 colours.
如果你的屏幕具有百万种颜色,你会发现灰色阴影穿越屏幕的变化很光滑。如果
你想看到阴影分钟值的不同“带”,就像我们在本网站的图片中所做的,把你
的显示器设置为数千种颜色,或者甚至是 256色。
You Can Save Your Shadow Maps你可以保存你的阴影图If you have generated a shadow map which you want to look at later, or compare with
another map, you may save the page (e.g. onto your desktop), just like any other web
page in HTML format, if you use Internet Explorer 4. Just choose Save from your file
menu, (and take care where you save it, and what you name it).
如果你已经生成了阴影图,想以后再看,或者和另外一张图比较,你可以保存
页面(例如,到你的桌面上),和其它任何 HTML 格式的网页一样,如果你使
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用的浏览器是 Internet Explorer 4。只用在文件菜单中选择保存,(注意你保存的
地方,和你的命名)。Read the Number of Minutes of Shadows in Each Cell
阅读每个单元阴影的分钟数if you have an Internet Explorer 4 browser, and you leave this option on when you
generate the map, you can do an exact readout (in the status line of your browser) of
the number of minutes there may be shadows in each cell by moving the cursor
around on the shadow map.
如果你使用 Internet Explorer 4浏览器,当你生成图像时留着这个选项,通过在
阴影图上移动鼠标,你可以精确的读出(在你的浏览器的状态行)每一个单元
阴影的分钟数。You May Recolour Your Result
你可以对结果重新着色The plot uses a number of standard colours which look logical on a colour screen. The
colours, however, may not be optimal if you wish to print the result on a black and
white printer. We have therefore included a facility which allows you to change the
colour scheme without redoing the long calculations: You may use a particular colour
in a "shadow zone" around the turbine. If you use a large high resolution map, it may
take a few minutes for your programme to do the recolouring (IE 4 is slower than
Netscape 4 for this).
使用大量标准色的绘图在彩色屏幕上看起来更加合理。然而,如果你希望把结果
在黑白打印机上打印出来,这些颜色可能不是最佳的。因此,我们已经包含了一382
个工具,允许你改变颜色方案而不用再做长时间的计算:你可以在风力机周围
的“阴影地带”使用一个特殊的颜色。如果你使用一个大的高分辨率图像,可能
需要花费数分钟去重新着色(对此 IE4 比Netscape 4浏览器慢)Paint Your Shadow Zone
描绘阴影地带You may modify your plot to show you any zone with a certain minimum number of
minutes of shadows in a certain colour. Be warned, however, that with a large high
resolution map, it will take several minutes to complete that process.
你可以修改你的绘图,用某一颜色显示具有某一最小阴影分钟数的任何地带。警
告:然而对于大的高分辨率图像,将会花费几分钟来完成这一过程。Other Calculator Usage
计算器的其它用法Incidentally, this calculator is very practical for photographers who wish to know
where the sun is before they go out to take a picture of their favourite motive in ideal
lighting conditions. (We tested it when photographing wind turbines, of course). You
may also use it if you wish to know how to place a terrace in your garden (regardless
of whether you want shadow or sun).
附带地,这个计算器对于那些在他们外出在理想光照条件下拍摄他们中意的照
片之前,希望知道太阳在哪里的摄影师非常实用。(当然,我们也可以在拍摄风
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力机时对其进行测试)。你也可以使用它,如果希望知道如何在自己的花园放置
一个阳台(无论你是否需要阴影或者阳光)。
Location位置You may either specify your turbine location using the pop up menu which gives the
longitude and latitude of a number of cities around the globe, or you may enter the
longitude and latitude in degrees and minutes directly, together with your time zone.
你可以使用弹出的菜单来详细说明你的风力机位置,菜单给出了全球许多城市
的经度和纬度,或者也可以直接输入经度和纬度的度和分值,以及你的时区。
Time Zone时区The time zone is automatically included, if you use the pop up menu with city names.
You may enter your time zone relative to GMT from the pop up menus, or you may
enter the standard time zone meridian, i.e. the longitude relative to Greenwich which
your local time system uses as a reference, which is generally a multiple of 15
degrees, corresponding to a one hour time difference. (India and a few other places
have a time zone which is a multiple of 7.5 degrees, i.e. half an hour).
如果你使用城市名的弹出菜单,会自动包含时区。你可以从弹出菜单中输入相对
于GMT的自己的时区,或者可以输入标准时区子午线,即经度相对于当地用作
参考的格林尼治时间,一般是 15度的倍数,对应 1个小时的时差。(印度和其
它少部分地方的时区是 7.5度的倍数,即半小时)
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Time时间You may enter date and time to see the sunrise and sunset times, plus the current
direction of the light coming from the sun.
你可以输入日期和时间,来看日出和日落的时间,加上当前太阳光线的方向。
Wind Turbine风力机Enter the hub height and the rotor diameter. A typical hub height for a 600-750 kW
wind turbine is 45 to 60 m, a typical rotor diameter is 43 to 48 m. (You may find
typical hub heights and rotor diameters using the Wind Turbine Power Calculator
turbine pop up menu).
输入轮毂高度和转轮直径。一个典型地 600-750kW风力机的轮毂高度为 45到 60
米,典型的转轮直径为 43到 48米。(你可以使用风力机 功率 计算器 弹出的菜单
找到典型的塔架高度和转轮直径)If you wish to study shadows in areas which are lower than the base of the wind
turbine, you can cheat, and increase the hub height of the turbine. Conversely, you can
lower the hub height, if you wish to study areas which are higher than the base of the
turbine.If you enter, say 0.5 for the rotor diameter, you may use the programme to
study the behaviour of a shadow from the top of a mast, or the corner of a building.
(Or you can use it to build your own sundial).
如果你希望研究低于风力机底座区域的阴影,你可以作假,并增加风力机轮毂
的高度。相反,你可以降低轮毂的高度,如果希望研究高于风力机底座的区域。
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如果你输入,比方说转轮直径是 0.5,你可以使用此程序来研究桅杆顶部或者建
筑物角落处的阴影特性。(或者你可以使用它建立自己的日晷)。
Shadow Plot阴影绘制You can specify the time range for which you like your shadow images computed.
You can select a minute, an hour, a day, a month, or a year.
你可以指定想要计算的阴影图片的时间范围。你可以选择一分钟、一个小时、一
天、一个月或者一年。You may set the plot area to fit your screen size (and/or paper output). If you have
enough RAM (and time) you may even specify a map larger than your screen.
你可以设置绘图区域以适应你的屏幕尺寸(和/或纸张输出)。如果你拥有足够
大的 RAM(和时间),你甚至可以指定比你的屏幕更大的图片。The default size prints well on A4 paper in landscape format. The resolution
parameter determines the area covered by each 3-25 pixel square.
缺省尺寸以自然格式可以很好地在A4纸上打印。分辨率参数决定了每个 3-25 像
素方格覆盖的区域。We recommend that you let each square represent less than half the rotor diameter to
get a decent plot.
我们推荐,你让每个方格所代表着少于半个转轮直径,以获得一个得体的图片。
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Or, even more cleverly, you may set it to match your map resolution, and print your
output on an acetate (overhead) foil as an overlay to a map of a prospective wind
turbine location. (One printed pixel is 1/72 of an inch (1 inch = 2.54 cm)).
或者更加聪明的是,你可以设置它来和你的图像分辨率相匹配,在醋酸纤维
(在上面)箔上打印你的输出,作为预期风力机位置图像上的镀层。(一个打印
像素为 1/72英寸(1英寸=2.54厘米))The step length in minutes determines how many rotor images the programme
projects onto your ground surface. The default step length of 4 minutes corresponds to
the sun
步长的分钟数决定了程序投射到地面上的转轮图片的多少。默认步长为 4分钟,
与太阳相对应。azimuth changing on average 1 degree between each simulation. You may save
processing time if you choose a longer step length. For a 1 month or 1 year simulation
results are generally not affected much by using 8 minute steps - and it is 8 times
faster than 1 minute steps. If the shadow image is not smooth, (or if it is asymmetrical
in the East-West direction even if you are not running with a fixed rotor direction or a
wind rose), your step length may be too large. If you double the step length, the
programme assumes that the rotor shadow stays in the same place for twice as long,
i.e. for each rotor image projected onto the ground, it adds the step length to a shadow
counter for that particular area.
每次仿真方位角平均改变 1度。如果选择一个更长的步长,你可以节省处理时间
对于 1个月或 1年的仿真结果,使用 8分钟的步长影响不大-并且比 1分钟的步387
长快 8倍。如果阴影图像不是很光滑,(或者其在东西方向不对称,甚至你还没
有在固定的转轮方向或风玫瑰图上运行),你的步长可能太大。如果你让步长加
倍,程序会假设转轮阴影在同一地点停留的时间也是两倍,即,对于投射在地
面上的每个转轮图像,增加了那个特殊区域阴影计数器的步长。You may choose rotor direction as random (default), which means the rotor may be
facing in any direction (random azimuth), you may choose worst case, where the rotor
always faces the sun.
你可以选择转轮方向为随机(缺省),这意味着转轮可能面向任意一个方向
(随机方位角),你可以选择最坏的情况,就是转轮总是面向太阳。You may choose a fixed rotor azimuth angle from -90 to 90 degrees. The angle is
measured relative to South, and the solar angle is positive before noon, regardless of
hemisphere. 0 means that the wind is coming form the South or North.
Southeast/Northwest is 45 degrees in the Northern hemisphere, and -45 degrees in the
Southern hemisphere. East/West is 90 or -90 degrees. To help you select the correct
angle, you may use the pop up menu.
你可以选择从-90到 90度的固定转轮方位角。角度相对于南方测量,无论哪个半
球,太阳的角度在中午之前为正。0意味着风力来自南方或北方。北半球的东南/
西北方向是 45度,在南半球是-45度。东/西方向是 90或-90度。你可以使用弹出
菜单,来帮助你选择正确的角度
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Finally, you may choose to enter a wind rose with a frequency distribution for your
wind directions. Since a normal propeller type wind turbine is symmetrical about its
rotor plane, you should add the percentages for North and South, and so forth in each
of your directions. The programme accepts 8, 12 and 16 compass directions, which
means that you specify 4, 6, or 8 percentages. The program checks that the sum is
exactly 100, before it is willing to do the simulation. Please note that wind roses are
specified with the North as 0 degrees, and that the degrees are given in a clockwise
direction (retrograde direction).
最后,你可以选择进入一个包含各个方向风的频率的风玫瑰图。由于一个普
通的桨叶型风力机是关于转轮平面对称的,你必须为北向和南向以及在你的每
一个方向上增加百分比。程序接受 8,12,16个指针方向,这意味着你需要制定
4,6,8的百分比。程序在仿真之前会严格检查总和是否为 100。请标注风玫瑰图
中北向为 0度,顺时针方向(反向)给定各个方向的度数。You should specify the fraction of daytime hours the turbine will be running. 0.75 is a
typical fraction. The basic result in terms of minutes of shadows is multiplied by this
fraction.
你应该指定风力机运行的日间小时分数,典型分数是 0.75。依据阴影分钟数的基
本结果要乘以这个分数。You should specify the fraction of daytime hours with bright sunshine. The basic
result in terms of minutes of shadows is multiplied by this fraction.
你应该指定日间日照小时分数。依据阴影分钟数的基本结果要乘以这个分数。389
If you have accurate statistics on the number of bright sunshine hours per month, you
may instead use that data in your calculations, by filling out the sunshine table at the
bottom of the page. In that case the programme uses the table data for each month
instead of the average.
如果你有每月日照小时数的精确数据,你可以在你的计算中通过填写网页底部
的日照表格,改为使用那些数。那种情况下,程序使用每个月的表格数据而不是
平均数据。We have included sunshine data for 3 Danish locations (you select them from the pop
up menu). If you have reliable monthly data available for your location, please e-mail
us (giving the source) so that we may include it in the city pop up menu. Remember to
check the box that says you want to use the table for your calculations. (A clever trick:
If you wish to see the pattern of shadows during e.g. June, July, and August only, you
may set the sunshine percentages for the three months only, and leave the rest of the
months at zero, and then run a simulation for a year, using the sunshine table).
我们已经包含了 3个丹麦地方的日照数据(可以从弹出菜单选择它们)。如果你
有自己位置的可用的月度数据,请用电子邮箱联系我们(给予资源),这样我
们可以将其加入到所在城市的弹出菜单。记得在邮件中写明你需要这个表格来进
行计算。(一个聪明的提醒:如果你仅希望看到例如 6、7和 8月期间的阴影图案,
你可以只设置这三个月的日照百分数,剩下的月份都设置为 0,然后使用日照
表运行 1年的仿真。)
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You may set a maximum distance from the wind turbine for the shadow plot, since it
is usually not relevant to look at distances above 7 to 10 rotor diameters or 1,000 m at
the most.
你可以在阴影绘制时设置与风力机之间的最大距离,因为当距离在 7至 10倍转
轮直径以上或者最多 1000米时,阴影通常看起来是不相关的。Finally, you may choose to have your output displayed with mouse-sensitive shadow
readout (for I.E. 4 browsers), which means that you may read the number of minutes
of shadow in each cell on the map in your browser's status line by placing the mouse
cursor on a particular cell. Using this mechanism increases RAM demand.
最后,你可以选择将你的输出以鼠标敏感阴影读出(对于 IE4浏览器)的方式
显示,这意味着通过放置鼠标在特定的单元,你可以在浏览器状态行中,读出
图像每个单元中的阴影分钟数。使用这种机制增大了 RAM 需求。
Sunrise 日出In this programme the sunrise time is defined as the moment a straight line to the
centre of the sun passes the horizon in the upwards direction on the date you have
entered in your data. In your local newspaper, you may find that the sunrise is defined
as being some minutes earlier, when the upper edge of the sun reaches the horizon. In
addition, the refraction (bending of the light) in the atmosphere means that you can
actually see the sun before it reaches the horizon. The sunrise is in local time, or
daylight saving time, if the Daylight saving time box is checked.
程序中,日出时间被定义为在你已经输入的数据时的日期,当太阳中心的直线
从向上方向穿过地平线的那一刻。在当地的报纸上,你可以发现日出被定义为早391
几分钟,即当太阳的上边缘到达地平线时。另外,大气中的折射(光的弯曲)意
味着,在其到达地平线之前你实际上可以看到太阳。如果夏令时框被选中,那么
日出时间是当地时间,或者夏令时。
Noon中午The solar noon is when the sun reaches it highest point in the sky, i.e. the solar
altitude is at its maximum. Noon is in local time, or daylight saving time, if the
Daylight saving time box is checked.
中午是太阳到达天空最高点的时候,即,太阳高度达到最大值。如果夏令时框被
选中,那么中午是当地时间,或者夏令时。
Sunset日落In this programme sunset time is defined as the moment a straight line to the centre of
the sun passes the horizon in the downwards direction on the date you have entered in
your data. In your local newspaper, you may find that the sunset is defined as being
some minutes later, when the upper edge of the sun reaches the horizon. In addition,
the refraction (bending of the light) in the atmosphere means that you can actually see
the sun after it goes below the horizon. The sunset is in local time, or daylight saving
time, if the Daylight saving time box is checked.
程序中,日落时间被定义为,在你已经输入的数据时的日期太阳中心的直线从
向下方向穿过地平线的那一刻。在当地的报纸上,你可以发现日落被定义为晚几
分钟,当太阳的上边缘到达地平线时。另外,大气中的折射(光的弯曲)意味着392
在其低于地平线以后你实际上可以看到太阳。如果夏令时框被选中,那么日落是
当地时间,或者夏令时。
Declination倾斜度The declination is the angle between the earth's equatorial plane, and the earth-sun
line. As the earth rotates, it spins around its axis which points to the North Star. This
axis is inclined 23.45° relative to the plane in which it orbits the sun. The angle
between the equatorial plane and the earth-sun line thus varies between +/-23.45°
during the year, being approximately zero on the 21/3 and 23/9 (Equinox), and
reaching its extreme values on 21/6 and 21/12 (Solstice). (Its precise value varies a bit
from year to year since a year is 365.25 days long).
倾斜度是地球赤道平面和地球太阳连线之间的角度。当地球旋转时,它绕着自己
指向北极星的轴旋转。这个轴的倾斜度是 23.45度,相对于地球绕太阳公转的轨
道平面。因此赤道平面与地球太阳连线之间的角度一年内在+/-23.45°之间变化,
在 3月 21日和 9月 23日(春/秋分)约为 0,在 6月 21日和 12月 21日(夏/冬
至)到达其极值。(它的精确数值逐年会有一点变化,由于一年有 365.25天)
Sunrise/Sunset Duration日出/日落持续时间This is the number of minutes and seconds it takes for the solar disc to move the
0.531° between the bottom and the top of the sun at sunrise or sunset. At the equator
the sunrise and sunset last little more than two minutes. As you move towards the
polar regions, the duration increases significantly, particularly in winter, as you may
verify by altering the latitude.
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日出或日落时,太阳圆盘在太阳的底部和顶部之间移动了 0.531度,这需要花
费数分和数秒的时间。赤道上日出和日落持续 2分钟多一点的时间。随着向极地
地区移动,持续时间增长很大,特别是在冬天,你可以通过修改纬度来证实。
Solar Azimuth太阳方位角The solar azimuth is the angle in the horizontal plane between the South and the sun
at the moment in time you have entered in your data. The angle is positive before
noon, negative after noon (regardless of hemisphere).
太阳方位角是南方和太阳之间的水平面角度,此刻太阳处于你已经输入的数据
中的时间的位置。这个角度在中午之前为正,中午之后为负(无论是哪个半球)
Solar Altitude太阳高度The solar altitude is the angle between the horizontal plane and the sun.
太阳高度是地平面与太阳之间的角度。Direction form the Sun (Sun Vector)
太阳的方向(太阳向量)If you are standing in the centre of the turbine with your back towards the South, and
you move x units of length to the right (East), y ahead (North), and z up (or rather -z
down), then a straight line from your new position to the centre of the turbine will be
pointing directly to the sun. The values for x, y, and z are given in the three boxes.
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如果你站在风力机的中央,背对着南方,向右(东)移动 x个单位长度,向前
(北)移动 y个,向上移动 z个(或者向下-z),然后从你的新位置到风力机中
心的直线将直接指向太阳。x,y和 z的值在三个框中给出。
Shadow calculator 阴影计算器
Wind Turbine Shadow Calculator风力机阴影计算器Do not operate the form until this page and its programme have loaded completely.
Otherwise the program will complain about missing data, and you will have to click
Reload. This calculator lets you experiment with your local conditions to determine
the shape and size of the local area which may be affected by shade (light flicker)
from a wind turbine. For an actual project you will probably want professional wind
project software which will help you with a lot of other aspects as well. (See the Links
section).
在本页面及其程序完全下载之前,不要操作表格。否则程序会报出丢失数据,你
必须点击重新下载。这个计算器使你使用当地的条件进行试验,来决定被风力机
阴影(光线闪烁)影响区域的形状和尺寸。对于一个实际的项目,你可能需要专
业的风力项目软件,它同样可以在其他很多方面帮助你。(查看链接部分)After changing data, use the tab key, click the Calculate button, or click anywhere on
the page outside the field you have updated to get the results in the right column. To
get a plot image, click on the Plot button. Click on the question marks for help. (If a
plot windows disappears, it is probably hidden behind this window).
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改变数据后,使用 tab健,点击计算按钮,或者点击你已经升级的区域以外的页
面的任何地方,在右栏中得到结果。点击绘图按钮,以得到所绘制的图像。点击
问号标志以获取帮助。(如果绘图窗口消失,可能是隐藏在本窗口的背后)。
CALCULATOR 计算器
Location位置Select:选择 or type类
型° ' latitude纬度 North北 South
南
° ' longitude 经度 East东 West 西Time Zone时区
° time zone meridian子午线时区East东 West 西
or GMT :
Time时间day日 month月
time时间 (0:00-23:59) : Daylight
saving time夏令时Wind Turbine风力机
m hub height,轮毂高度 m rotor
Results this Day
本日结果
Sunrise日出 :
Noon中午 :
Sunset日落 :
Declination倾斜度 °
Sunrise/sunset duration
日出/日落持续时间min.分 sec.秒
Results this Minute这一分钟的结果
Solar azimuth 太阳方位角 °
Solar altitude太阳高度 °
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diameter转轮直径 Direction from the sun太阳方向
(East, North, Up
coordinates)东,北,上Shadow Plot阴影绘制
this... minute分钟 hour小时 day日 month月 year年,
step 步长 minute(s)
Plot area 绘制区域 height高 width 宽 pixels 像素, resolution分辨率 = m per pixels 像素Rotor direction (azimuth) 转轮方向(方位角) random随机 worst case
(Darrieus)最坏情况(达里厄)
facing azimuth面向方位角 ° = use wind rose
table below使用下面的风玫瑰表Turbine running % of the daytime. 风力机日间运行时间Max. distance最大距离 m
Sunshine % of the time日照时间 OR check here或选中这里 to use
monthly sunshine hours from table below.使用下表的月度日照小时Include mouse sensitive shadow duration readout (only useful if used with an
I.E. 4 browser)
包括鼠标敏感阴影持续时间读出(仅适用于 IE4浏览器)*)= Cities marked with an asterisk in the city popup menu include sunshine and wind rose data for the tables below.
城市弹出菜单中被星号标记的城市,包括下表中的日照和风玫瑰图数据397
Bright Sunshine Table 日照表
Wind Rose Table 风玫瑰图表
Month月DaytimeHours
日间小时
BrightSunshineHours
日照小时
BrightSunshineper cent
日照百分比
Using使用
directions方向wind rose sector (not
azimuth) %风玫瑰区(不是方位角)
January一月 °
February 二月 °
March三月 °
April四月 °
May五月 °
June六月 °
July七月 °
August 八月 °
September九月 Total ... ... ...
October 十月
Total must be 100%总计必须为 100%
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November 十一月
December 十二月
Year Total
年总计:
Daytime hours are computed automatically by this programme.
本程序会自动计算日间小时。Source for bright sunshine hours:
日照源小时:
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To print the results of the plotter programme you should make a screen dump
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要打印绘图机程序的结果,需要进行屏幕 保存 。
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Economics 经济性
Turbine costs 风力机 成本
What does a Wind Turbine Cost?
风力机都有哪些方面的成本?The Price Banana
价格“香蕉图”
The graph above gives an impression of the price range of modern, Danish grid
connected wind turbines as of February 1998. As you can see prices vary for each
generator size. The reasons are e.g. different tower heights, and different rotor
diameters. One extra metre of tower will cost you roughly 1 500 USD. A special low
wind machine with a relatively large rotor diameter will be more expensive than a
high wind machine with a small rotor diameter.
上面的图给出 1998年 2月丹麦一种现代的并网风力机价格范围图。正如你所看
到的价格随着发电机的尺寸不同而变化。原因有诸如不同的塔架高度和转轮直径
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塔架每额外高出一米所需的成本大约是 1500 美元。但是转轮特别低直径相当大
的风力机的成本比高风力机小转轮直径的成本要高很多。Economies of Scale
规模经济As you move from a 150 kW machine to a 600 kW machine, prices will roughly
triple, rather than quadruple. The reason is, that there are economies of scale up to a
certain point, e.g. the amount of manpower involved in building a 150 kW machine is
not very different from what is required to build a 600 kW machine. E.g. the safety
features, and the amount of electronics required to run a small or a large machine is
roughly the same. There may also be (some) economies of scale in operating wind
parks rater than individual turbines, although such economies tend to be rather
limited.
600千瓦的风力机价格大约是 150千瓦风力机的三倍,而不是四倍。原因在于容量
达到某个点时有规模经济效应,例如,安装一台 150kW的风力机的人力成本和
安装 600kW的差不多,安全特征基本上一样,而且用来控制不同机器用到的电
子设备大小基本上也是一样的。经营风电场比起经营单个风力机可能也有规模经
济效应,尽管这样的经济效应往往相当有限。Price Competition and Product Range
价格竞争和产品的范围Price competition is currently particularly tough, and the product range particularly
large around 1000 kW. This is where you are likely to find a machine which is
optimised for any particular wind climate.
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价格竞争目前特别艰难,产品的范围已经大到大约 1000千瓦。这种风力机就是
那种经过优化设计的针对任何特殊的风况都适用的风力机。Typical 1000 kW Machines on the Market Today
目前市场上典型的 1000千瓦设备Even if prices are very similar in the range from 600 to 750 kW, you would not
necessarily want to pick a machine with as large a generator as possible. A machine
with a large 750 kW generator (and a relatively small rotor diameter) may generate
less electricity than, say a 600 kW machine, if it is located in a low wind area. The
working horse today is typically a 1000 kilowatt machine with a tower height of some
60 to 80 metres and a rotor diameter of around 54 metres.
即使在 600-750千瓦之间价格非常相似,人们也并不一定要选择那种尽可能大
的发电机。750kW的风电(转轮直径相对较小)机组,如果机组安装在低风区,
发出来的电可能比 600kW机组发的还少。目前的典型机组是 1000kW的机组,
塔高在 60~80米之间,转轮的直径大约 54米。1000 Dollars per Kilowatt Average
平均每千瓦 1000 美元The average price for large, modern wind farms is around 1000 USD per kilowatt
electrical power installed. (Note, that we are not talking about annual energy
production, yet. We'll return to that in a couple of pages. Energy production is
measured in kilowatt hours. If this sounds confusing, take a look at the Reference
Manual of this web site).
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建立现代大型风力发电厂的平均价格约 1000 美元/千瓦。(注意:我们没有考虑每
年生产的电能。需要说明一下,能源生产是以千瓦小时计算的。如果这听起来令
人费解,看一看这个网站的参考手册)。For single turbines or small clusters of turbines the costs will usually be somewhat
higher. On the next page we will discuss installation costs further.
对于单个或小规模的风力机,成本通常稍高一些。下一页我们将讨论安装成本。
Turbine installation 风力机安装 ,
Installation Costs for Wind Turbines
风力机的安装成本Novar Wind Farm, Scotland, under construction in a moor, July 1997. Photograph by Steffen Damborg
苏格兰 Novar风力发电厂,1997
年 7 月在野外建 设中。Steffen
Damborg摄。
Installation costs include foundations, normally made of reinforced concrete, road
construction (necessary to move the turbine and the sections of the tower to the
building site), a transformer (necessary to convert the low voltage (690 V) current
from the turbine to 10-30 kV current for the local electrical grid, telephone connection
for remote control and surveillance of the turbine, and cabling costs, i.e. the cable
from the turbine to the local 10-30 kV power line.
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安装成本包括基础,通常由钢筋混凝土制成、道路建设(将机组和塔架运输到安
装地点的必要步骤)、变压器(将机组输出的低压(690V)转换为电网的 10-30
千伏)、远程控制和维护机组的通讯设施以及电缆的成本,例如从机组到当地
10-30千伏线路的电缆。Installation Costs Vary
安装成本的变化Obviously, the costs of roads and foundations depend on soil conditions, i.e. how
cheap and easy it is to build a road capable of carrying 30 tonne trucks. Another
variable factor is the distance to the nearest ordinary road, the cost of getting a mobile
crane to the site, and the distance to a power line capable of handling the maximum
energy output from the turbine.
很明显,道路和基础设施建设的成本有赖于土壤条件,即如何便宜、方便的建立
一条可承载 30吨的卡车的道路。另一个可变因素是安装地点到最近的普通道路
的距离,将移动式吊车开到安装地点的成本以及从安装地点到能够接纳机组输
出最大能量的电网的距离。A telephone connection and remote control is not a necessity, but it is often fairly
cheap, and thus economic to include in a turbine installation.
电话联系和远程控制并非必要,不过由于通常是比较便宜,因而将其成本包括
在风力机的安装里。406
Transportation costs for the turbine may enter the calculation, if the site is very
remote, though usually they will not exceed some 15 000 USD.
如果场址很远的话风力机的运输成本可能需要考虑在内,不过通常不会超过 1.5
万美元。Economies of Scale
规模经济It is obviously cheaper to connect many turbines in the same location, rather than just
one. On the other hand, there are limits to the amount of electrical energy the local
electrical grid can handle (see the section on Wind Turbines in the Electrical Grid). If
the local grid is too weak to handle the output from the turbine, there may be need for
grid reinforcement, i.e. extending the high voltage electrical grid. It varies from
country to country who pays for grid reinforcement - the power company or the owner
of the turbine.
显然将同一个地点的许多风力机连接在一起再并网是较为节省成本的一种方案,
而非单个机组并网。另一方面,当地电网能够接纳的电力是有限的(参看《电网
中的风力机》一节)。如果当地的电力网太弱难以接纳风力机输出的电能,可能
需要加强电网建设。例如提高电网电压的等级。在不同国家风电公司或者风电场
商加强电网建设的成本是不一样的。
O & M 运行和维护
Operation and Maintenance Costs for Wind Turbines
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风力机的运行和维护成本Modern wind turbines are designed to work for some 120 000 hours of operation
throughout their design lifetime of 20 years. That is far more than an automobile
engine which will generally last for some 4 000 to 6 000 hours.
现代风力机的设计寿命一般 20年,工作时间大约为 12万小时。这个数字远
远高于汽车发动机大约 4000至 6000小时的运行时间。Operation and Maintenance Costs
运行和维护成本Experience shows that maintenance cost are generally very low while the turbines are
brand new, but they increase somewhat as the turbine ages.
经验表明,全新的风力机维护成本一般非常低,但是随着机组寿命的增加
相应有些增加。Studies done on the 5000 Danish wind turbines installed in Denmark since 1975 show
that newer generations of turbines have relatively lower repair and maintenance costs
that the older generations. (The studies compare turbines which are the same age, but
which belong to different generations).
1975年对 5000台安装在丹麦的风力机的研究表明,较新一代的风力机维护
成本比老一代风力机的维护成本相对较低(研究中比较的是寿命相同但是属于
不同年代的风力机)。Older Danish wind turbines (25-150 kW) have annual maintenance costs with an
average of around 3 per cent of the original turbine investment. Newer turbines are on
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average substantially larger, which would tend to lower maintenance costs per kW
installed power (you do not need to service a large, modern machine more often than
a small one). For newer machines the estimates range around 1.5 to 2 per cent per
year of the original turbine investment.
老一代的丹麦风力机(25-150千瓦)每年的维修成本大约为初始投资的百
分之三。较新的风力机一般单机容量都比较大,这就使得每千瓦的维护成本有所
降低(大型现代化风力机的维护次数和小型的基本一样)。较新型的风力机估计
每年的维护成本约占初始投资的 1.5~2个百分点。Most of maintenance cost is a fixed amount per year for the regular service of the
turbines, but some people prefer to use a fixed amount per kWh of output in their
calculations, usually around 0.01 USD/kWh. The reasoning behind this method is that
tear and wear on the turbine generally increases with increasing production.
每年为风力机定期检修,因而大部分的维修成本是固定的,但有人更喜欢
按照每输出千瓦时的能量所需的成本来计算维修费,通常约为 0.01 美元/千瓦时。
这种计算方法考虑到风力机输出的电力越大,撕裂和磨损就越严重。Economies of Scale
规模经济Other than the economies of scale which vary with the size of the turbine, mentioned
above, there may be economies of scale in the operation of wind parks rather than
individual turbines. These economies are related to the semi-annual maintenance
visits, surveillance and administration, etc.
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除了上面提到的随着风力机大小不同产生的规模经济效应外,可能还有不
同于单个风力机的风电场产生的规模经济效应。这些经济性体现在每半年的维护
监督和管理等。Turbine Reinvestment (Refurbishment, Major Overhauls)
风力机再投资(整修,大修)Some wind turbine components are more subject to tear and wear than others. This is
particularly true for rotor blades and gearboxes.
某些风力机的部件更容易撕裂和磨损。对于叶片和齿轮箱 就更为突出。Wind turbine owners who see that their turbine is close the end of their technical
design lifetime may find it advantageous to increase the lifetime of the turbine by
doing a major overhaul of the turbine, e.g. by replacing the rotor blades.
那些有长期运行经验的风力机的业主发现通过对风力机进行一次重要的大
修可以延长机组的寿命,比如更换叶片。The price of a new set of rotor blades, a gearbox, or a generator is usually in the order
of magnitude of 15-20 per cent of the price of the turbine.
一套新的叶片,齿轮箱或者发电机的价格通常占到原来旧的机组价格的
15~20%。Project Lifetime, Design Lifetime
项目寿命,设计寿命
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The components of Danish wind turbines are designed to last 20 years. It would, of
course, be possible to design certain components to last much longer, but it would
really be a waste, if other major components were to fail earlier.
丹麦风力机的部件的设计寿命约为 20年。当然有可能将某些部件的寿命设
计的更长,但是如果其他主要部件较早的发生故障,那这真的就只是一种浪费
了。The 20 year design lifetime is a useful economic compromise which is used to guide
engineers who develop components for the turbines. Their calculations have to prove
that their components have a very small probability of failure before 20 years have
elapsed.
用 20年的设计寿命来指导工程师们开发风力机的部件是一个折中的经济性
方案。工程师们必须通过计算证明他们设计的部件在使用 20年之前发生故障的
可能性非常小。The actual lifetime of a wind turbine depends both on the quality of the turbine and
the local climatic conditions, e.g. the amount of turbulence at the site, as explained in
the page on turbine design and fatigue loads.
一个风力机的实际使用寿命取决于风力机的质量和当地的气候条件,比如
在现场的湍流量,正如在风力机设计和疲劳载荷那一部分内容中所提到的。Offshore turbines may e.g. last longer, due to low turbulence at sea. This may in turn
lower costs, as shown in the graph on the page on the Economics of Offshore Wind
Turbines.
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由于海上湍流较低,所以离岸发电机组的寿命可能会更长。这可能反过来降
低成本,正如海上风力机的经济性那节的图中所显示的。
Income from wind energy 风能的收入
Income from Wind Turbines
风能的收入Energy Output from a Wind Turbine
风力机的能量输出If you have read the page on Annual energy
output from a wind turbine, this graph will
already be familiar to you.
如果您已经看过风力机年发电量那一页,
该图您将非常熟悉。The graph shows how annual energy
production in million kilowatt hours varies with the windiness of the site. With a
mean wind speed of, say 6.75 metres per second at hub height you get about 1.5
million kilowatt hours of energy per year.
该图显示了每年输出的以百万千瓦小时计量的电量随着当地风况的变化情
况。假如在中心高度处的平均风速为 6.75米每秒钟,每年能够获得的电量约为
150万千瓦小时。
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As you can see, annual energy output varies roughly with the cube of the wind speed
at turbine hub height. Just how sensitive energy production is to wind speed varies
with the probability distribution for the wind, as explained in the page on the Weibull
distribution. In this graph we have three examples with different k-values (shape
factors). We will be working with the red curve (k=2) in our example.
正如你能看到的,年发电量大致随着风力机中心高度风速的三次方而变化。
发电量与风速有一种概率分布的关系,如Weibull分布那一页所解释的。在这幅
图中给出了三个不同的 k-值(形状因子)。下面的例子将以红色曲线(k=2)展
开讨论。The Availability Factor
可利用系数The figures for annual energy output assume that wind turbines are operational and
ready to run all the time. In practice, however, wind turbines need servicing and
inspection once every six months to ensure that they remain safe. In addition,
component failures and accidents (such as lightning strikes) may disable wind
turbines.
年度发电量的数据是在风力机一直都在运行中或者准备运行的假定下得到
的。然而在实际情况中,风力机每半年需要一次维修和检查,以确保其安全性。
此外,部件故障和事故(如雷击)可能会损坏风力机。Very extensive statistics show that the best turbine manufacturers consistently achieve
availability factors above 98 per cent, i.e. the machines are ready to run more than 98
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per cent of the time. Total energy output is generally affected less than 2 per cent,
since wind turbines are never serviced during high winds.
大量的统计数据显示,最好的风力机制造商能够持续获得 98%以上的可用
系数,即风力机实际运行时间能够达到设计时间的 98%。大风时候停止发电对
总发电量影响一般不到 2%。Such a high degree of reliability is remarkable, compared to other types of machinery,
including other electricity generating technologies. The availability factor is therefore
usually ignored when doing economic calculations, since other uncertainties (e.g.
wind variability) are far larger.
相对于其他类型的机器,包括其他发电技术,这么高的可靠性是非常显著
的。因此在经济性计算时可用系数因素通常被忽略,因为其他不确定因素(如风
力的变话)的影响大得多。Not all wind turbine manufacturers around the world have a good, long reliability
record, however, so it is always a good idea to check the manufacturers' track record
and servicing ability before you go out and buy a new wind turbine.
然而,不是世界上所有的风力机制造商都有一个良好的,长期的可靠性记
录,因此在你购买一台新的风力机之前,最好能够先检查一下制造商的业绩和
服务的能力。
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Tariffs 价目表
Wind Energy and Electrical Tariffs
风能和电价This page is relevant for private investors in wind
energy, but not for power companies, which of course
know everything about their own tariff system.
本页只和风力发电私人投资者相关,和电力公司
无关,因为他们当然了解他们自己的电价系统。Electrical Energy Tariffs
电能价格Electricity companies are generally more interested in buying electricity during the
periods of peak load (maximum consumption) on the electrical grid, because this way
they may save using the electricity from the less efficient generating units. According
to a study on the social costs and benefits of wind energy by the Danish AKF institute
(see the Links page), wind electricity may be some 30 to 40 per cent more valuable to
the grid, than if it were produced completely randomly.
电力公司一般更乐于在高峰负荷(最大消费)期间购买电网上的风电,因
为这样他们可以节省低效率机组所发的电力。根据丹麦 AKF 研究所(见链接页
面)所做的一项有关风能的社会成本和效益的研究,并网风力发电比完全随机
的发电的价值高大约 30至 40个百分点。
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In some areas, power companies apply variable electricity tariffs depending on the
time of day, when they buy electrical energy from private wind turbine owners.
在一些地区,电力公司在向私人风力机的业主购买电能的时候要求每天不
同时刻的电价有所区别。Normally, wind turbine owners receive less than the normal consumer price of
electricity, since that price usually includes payment for the power company's
operation and maintenance of the electrical grid, plus its profits.
一般情况下,风力机业主收到的电费比正常的电力消费价格要低,因为这
个价格通常还包括了电力公司的运作及电网维护,还要加上其利润。Environmental Credit
环境信用Many governments and power companies around the world wish to promote the use
of renewable energy sources. Therefore, they offer a certain environmental premium
to wind energy, e.g. in the form of refund of electricity taxes etc. on top of normal
rates paid for electricity delivered to the grid.
世界上许多政府和电力公司希望促进可再生能源的使用。因此,他们对风电提供
一定的环境补价,例如以最高正常税率退还输送到电网的风电的电力税等形式。
Capacity Credit 容量信用To understand the concept of capacity credit, let us look at its opposite, power tariffs:
Large electricity customers are usually charged both for the amount of energy (kWh)
they use, and for the maximum amount of power (kW) they draw from the grid, i.e.
customers who want to draw a lot of energy very quickly have to pay more. The
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reason they have to pay more is, that it obliges the power company to have a higher
total generating capacity (more power plant) available.
为了理解容量信用的概念,让我们看看与其相反的概念,电费:大型电力
用户通常不仅要按照他们所使用的电能(千瓦时)交纳费用,并且还需要按照
他们从电网消耗的最大功率(千瓦)交费,比如想要很快的从电网获得很多能
量的用户就要交纳更多的费用。之所以需要多交费在于他们的要求使得电力公司
需要建立容量更高的电网。Power companies have to consider adding generating capacity whenever they give
new consumers access to the grid. But with a modest number of wind turbines in the
grid, wind turbines are almost like "negative consumers", as explained in the section
on Wind turbines in the electrical grid: They postpone the need to install other new
generating capacity.
每当电力公司的电网上增加新的用户时,就需要考虑增加发电量。不过由于
并网风力机数量有限,而且是一个“负的消费者”(也就是风力机是向电网输送
而非消耗电网的电量),正如电网中的风力机一节所解释的:风力机的加入无
需增加新的其他方式的发电量。Many power companies therefore pay a certain amount per year to the wind turbine
owner as a capacity credit. The exact level of the capacity credit varies. In some
countries it is paid on the basis of a number of measurements of power output during
the year. In other areas, some other formula is used. Finally, in a number of areas no
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capacity credit is given, as it is assumed to be part of the energy tariff. In any case, the
capacity credit is usually a fairly modest amount per year.
因此,许多电力公司每年向风力机业主支付一定的费用,作为容量信用。容
量信用的确切水平是不同的。有些国家是基于风力机一年内输出的电量进行奖励
另外一些地区使用别的公式计算奖励费用。最终在很多地区没有容量信用,因为
把这部分奖励当作了电费的一部分。不管怎样,每年的容量信用通常是很有限的Reactive Power Charges
无功功率的收费Most wind turbines are equipped with so called asynchronous generators, also called
induction generators, cf. the section on electrical parts of a wind turbine. These
generators require current from the electrical grid to create a magnetic field inside the
generator in order to work.
大多数风力机配备有所谓的异步发电机,也称为感应发电机,参看关于风
力机配件部分一节。这些发电机需要从电网取电以建立电机内部的磁场,这样发
电机才能工作。As a result of this, the alternating current in the electrical grid near the turbine will be
affected (phase-shifted). This may at certain times decrease (though in some cases
increase) the efficiency of electricity transmission in the nearby grid, due to reactive
power consumption.
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由于这一结果,在风力机附近的电网交流电会受到影响(发生相移)。由于
电流发生相移会产生无功功率,这就可能会在某些时候减少(尽管在某些情况
下会增加)电网的电力传输效率。In most places around the world, the power companies require that wind turbines be
equipped with switchable electric capacitor banks which partly compensate for this
phenomenon. (For technical reasons they do not want full compensation). If the
turbine does not live up to the power company specifications, the owner may have to
pay extra charges.
在世界各地的大多数地方,电力公司要求风力机配备有用来部分补偿这一
现象的投切电容器。(由于技术原因,他们不想全额赔偿)。如果风力机不符合
电力公司的规范,业主可能需要支付额外的费用。Normally, this is not a problem which concerns wind turbine owners, since the
experienced manufacturers routinely will deliver according to local power company
specifications.
通常,这不是一个会影响到风力机业主的问题,因为有经验的制造商通常
会提供按当地电力公司的规范进行发电。
Investment in wind power 风电的投资
Basic Economics of Investment
投资的基本经济学419
Social Return from Investment in Wind Energy
风能投资的社会回报On the next two pages, we look at the economics of an investment in wind energy
from the point of view of society as a whole, as economists typically do. If you do not
like economics, or if you know everything about it in advance, skip this page.
在接下来的两页,我们将像典型的经济学家所作的那样,从整个社会的观
点来看看风能投资的经济学。如果您不喜欢经济学或者您以前就知道有关的知识
可以跳过这一页。We do not account for environmental benefits, we shall do that later. We do not look
at financing or taxation. These items vary enormously from one country to the other,
but they do not make any nation richer or poorer: They only serve to redistribute
income.
我们不考虑环境效益,以后再考虑这一点。我们不看融资或税收。这些东西
各个国家之间有着很大的区别,但是却不会使任何国家变得更富强或者更贫穷:
他们仅仅是收入再分配的手段。What society gets in return for investment in wind energy is pollution-free electricity;
let us find out how much that costs.
投资风能的社会效益体现在无污染的电力,让我们看看为此我们需要付出
的代价。Private Investors' Guide
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私人投资者指南If you are a private investor in wind energy you can still use our calculations - pre tax,
that is: Generally speaking, investments which have a high rate of return before tax
will have an even higher rate of return after taxes.
如果您是一个风力发电的私人投资者,您也可以使用我们的计算方式——
在税前,即:一般而言,在税前有高的回报率的投资将在税后有更高的投资回
报率。This is a surprise to most people.
这使大多数人感到惊奇。The reason is, however, that depreciation regulations for all sorts of business tend to
be very favorable in most countries. With rapid tax depreciation you get a higher
return on your investment, because you are allowed to deduct the loss of value of your
asset faster than it actually loses it value. This is nothing special for wind turbines. It
is true for all sorts of business investment.
然而,原因是,对各种业务的折旧规定往往在大多数国家对投资者是非常有利
的。如果有快速的税折旧,您将得到更高的投资回报,因为允许您扣除资产价值
损失的速度比它实际上折旧的速度还要快。这对风力机是一样的。因为(这个规
定)对各种商业投资都是适用的。Once again, do note, that our calculations in real terms omit financing and taxes. As a
prudent investor, you would probably want to plan your cash flow to make sure you
421
can pay your debts. This you obviously have to calculate in money terms, i.e. in
nominal terms.
请再次注意,我们的计算忽略了融资和税收。作为一个精明的投资者,您可
能希望自己的资金流能够确保偿还债务。在资金方面您显然需要将其计算在内,
比如,在名义上要考虑进去。Working with Investments
投资工作With any investment, you pay something now to get something else later. We assume
that a dollar in your pocket today is more valuable to you than a dollar tomorrow. The
reason why we say that, is that you could invest that dollar somewhere or put it into a
bank account and earn interest on it.
任何投资都是现在付出一些东西而后收回一些东西。我们假设今天你口袋里
的 1 美元要比明天的 1 美元更有价值。我们之所以这样说,是因为您可以将其投
资在某些地方,或者存入银行以赚取利息。To tell the difference between today's and tomorrow's dollars, we therefore use the
interest rate. If we do that, 1 dollar a year from now is worth 1/(1+r) to you today. r is
the interest rate, for example 5 per cent per year.
我们用利率的概念来解释今天和明天的美元之间的区别。如果我们用其投资
从现在算起一年后的 1 美元对今天的你是 1/(1+r)美元,r是利率,假如是 5%。Thus 1 dollar a year from now is worth 1/1.05 = 0.9523 dollars today. 1 dollar 2 years
from now is worth 1/(1.05*1.05) = 0.9070 and so forth... 422
因此,一年后的 1 美元今天的价值是 1/1.05=0.9523 美元。2年后的 1 美元现
在的价值是 1/(1.05*1.05)=0.9070等等...
But what about inflation? To deal with that we shall simply only work with dollars
which have the same purchasing power as a dollar does today. Economists call that
working with real values, instead of nominal ones.
但如果发生通货膨胀呢?为了处理这种情况,我们只能简单地认为以后的
美元和今天的美元有相同的购买力。经济学家称之为以实际价值,而非面值。Work in Real Values, not Nominal Values
以实际价值而非面值进行讨论An investment in a wind turbine gives you a real return, i.e. electricity, and not just a
financial (cash) return. This is important, because if you expect some general inflation
of prices during the next 20 years, you may expect electricity prices to follow the
same trend.
风力机的投资给您真实的回报,即电力,而不仅仅是财产(现金)的回报。
这一点很重要,因为如果您认为在未来 20年的会发生通货膨胀,您可能会预期
的电价将遵循同样的趋势。Likewise, we would expect operation and maintenance costs to follow roughly the
same price trend as electricity. If we expect all prices to move in parallel (with the
same growth rates) over the next 20 years, then we can do our calculations quite
simply: We do not need to adjust or calculations for inflation, we simply do all of our
calculations in the price level of our base year, i.e. the year of our investment.
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同样,我们预计运行和维护成本将按照和电价大致相同的价格趋势变化。如
果我们预计所有商品的价格以相同的趋势变化(在未来 20年有相同的增长率),
那么我们可以非常简单的进行计算:计算时无需调整或者考虑通货膨胀,我们
只需要简单的按照参考年份(例如投资的那一年)的价格水平进行计算即可。In other words, when we work with real values, we work with money which represent
a fixed amount of purchasing power.
换句话说,当我们考虑实际价值时,我们是在计算代表了固定购买力的纸币。Use the Real Rate of Interest, not the Nominal Rate
使用实际利率,而非票面利率Since we are studying the real rate of return (profitability) of wind energy, we have to
use the real rate of interest, i.e. the interest rate minus the expected rate of inflation.
(If both rates are high, say, above 10 per cent, you cannot really subtract the
percentages, you should divide like this (1+r)/(1+i) but let's not make this into a
course in economics).
由于我们是在研究风能的实际收益率(盈利能力),因此必须使用实际利
率,即利率减去预期的通货膨胀率。(如果这两个比率都很高,假如是百分之十
以上,就不能真的去减这个百分比,而应该用(1+r)/(1+i),但是请不要认
为这是经济学理论的内容)。Typical real rates of interest for calculation purposes these days are in the vicinity of 5
per cent per annum or so. You may say that in countries like Western Europe you
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could even go down to 3 per cent. Some people have a very high demand for
profitability, so they might wish to use a higher real rate of interest, say, 7 per cent.
Using the bank rate of interest is nonsense, unless you then do nominal calculations,
i.e. add price changes everywhere, including to the price of electricity.
目的计算利息的典型实际利率在每年百分之五左右。您可能会说,像西欧国
家,甚至可以低到百分之三。有些人希望有很高的利润率,所以他们可能希望使
用一个更高的实际利率,例如,百分之七。利用银行的利息率是没有意义的,除
非你是要按照名义利率进行计算,即在每个地方都要考虑价格变动,包括电价。
Economics of wind energy 风能经济学
Wind Energy Economics
风能经济学There is no Such Thing as a Single Price for Wind Energy
没有什么东西的价格像风能一样的不固定As we learned from the page on energy output,
annual electricity production will vary
enormously depending on the amount of wind on
your turbine site. Therefore, there is not a single
price for wind energy, but a range of prices,
depending on wind speeds.
425
正如从能量输出一页所看到的,年发电量将随着风力机安装地点的不同有
很大的区别。因此,没有一个单一的风力发电的价格,而是一个取决于风速的价
格范围。The graph to the right shows how the cost of electricity produced by a typical Danish
600 kW wind turbine varies with annual production. (We used the example built into
the Wind Energy Economics Calculator to find the points for the graph).
右边的图显示了一台典型的丹麦 600千瓦风力机的发电成本随年发电量的
变化曲线。(我们利用风能经济学计算器一节建立的例子找到了图中的点)。The relationship is really very simple: If you produce twice as much energy per year,
you pay half the cost per kilowatt hour. (If you believe that maintenance costs
increase with turbine use, the graph might not be exactly true, but close to true).
这种关系其实非常简单:如果每年生产两倍的电量,那每千瓦时所负担的
成本将只有原来的一半。(如果认为风力机的维修成本随着使用的增加而增加,
那么图形可能不完全如此,但也是接近真实的)。If we use the graph above, plus the example from the page on income from wind
turbines we find the relationship between wind speeds and costs per kWh below.
如果我们使用上面的图,加上风力机的收入一节所讲的例子,我们将发现
下面每千瓦时的成本与风速之间的关系。
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Remember, that everything on this page is based on our examples, so you cannot use the graph to predict costs for any particular project.
请记住,本页所讲的一切都以我们的事例为基础,所以你不能将此图用来预测任何特定项目的成本。As an example, if your real rate of interest is 6 per cent per annum, rather than 5, costs
are approximately 7.5 per cent higher than shown in the graph. When you use the
Wind Energy Economics Calculator in a moment, you can use your own data to
compute the cost of electricity.
例如如果你的实际利率为年息百分之六,而不是百分之五,成本约比图示
中的高出百分之七点五。当您在什么时候需要利用风能经济学计算器来计算电力
成本时,你可以使用自己的数据来计算。
The example is for a 600 kW wind turbine with project lifetime of 20 years;
investment = 585,000 USD including installation; operation & maintenance cost =
6750 USD/year; 5% p.a. real rate of interest; annual turbine energy output taken from
power density calculator using a Rayleigh wind distribution (shape factor = 2).
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这个例子是一个 600千瓦设计寿命为 20年的风力机,投资=585,000 美元,
包括安装,操作和维护成本=6750 美元/年,实际利率为年息 5%,利用 Rayleigh
风分布(形状系数=2)根据功率密度计算器计算风力机的年发电量。You should note that wind speeds at 50 metre hub height will be some 28 to 35 per
cent higher* than at 10 metre height, which is usually used for meteorological
observations, cf. the wind speed calculator page. Look at the grey axis at the bottom
of the graph to see how wind speeds at 10 metre height may translate into higher wind
speeds. A wind speed of e.g. 6.25 m/s at 10 metre height in roughness class 1 will
translate into 8 m/s at 50 metre hub height.
需要注意的是,在中心高度 50米处的风速比 10米处的风速高约 28~35%,
这种估计通常用于气象观测,参照风速计算器一页的内容。从上图底部的灰色轴
能够看到 10米高处的风速与更高处风速的对照关系。例如在粗糙等级为 1的地
方,如果 10米高度处的风速为 6.25米每秒,则可以估计出 50米的中心高度处
的风速为 8米每秒。 For roughness classes between 1 and 2.
*粗糙度等级为 1至 2之间。
Traps in analyses 分析中易犯的错误
Pitfalls in Wind Energy Cost Analysis
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风力发电成本分析中易犯的错误Many studies of the cost of wind energy and other renewables are poor science,
because of a lack of understanding of both the technology and the economics
involved. Frequently people who understand the economics do not understand the
technology and vice versa - and sometimes neither!
对风能和其他的可再生能源成本的研究是一门很不完善的学科,因为缺乏
对有关的技术和经济学知识的理解。通常理解经济学知识的人不了解技术,而了
解技术的反过来却不了解经济学——有时候两者都不懂。This page warns you against the most common pitfalls. Even trained economists have
fallen into these pits, and misleading comparisons of costs of different energy
technologies are unfortunately not uncommon.
本页面警告读者不要犯最常见的错误。即使是颇有经验的经济学家们也曾犯
过这些错误。不幸的是在这些错误指导下产生的不同能源技术的比较成本还是很
常见的。What are the Costs of Wind Power Generation?
什么是风力发电的成本呢?1. economic depreciation of your investment
投资的经济折旧2. interest on the capital invested
资本投资的利息429
3. operation and maintenance costs
运行和维修成本If you think that the amount required to buy a wind turbine is a cost or an expenditure,
you are wrong, and you do not understand basic bookkeeping or economics. In that
case, stay away from cost analysis! Profit is not a cost either. If you think it is, keep
away from the rest of this page, and take a course in economics first.
如果你认为购买风力机所需的费用是一种成本或开支,那么您错了,因为
你不明白基本的财务或经济学。在这种情况下,就不要做成本分析!利润也不是
成本。如果你不这么认为,那么本页剩下的内容就不用看了,请先去上一节经济
学的课程。Depreciation
折旧Economic depreciation is a bit trickier. You simply cannot calculate the economic
depreciation of your investment unless you know the income from your investment.
That comes as a surprise to many people, including some economists. But
depreciation is simply defined as the decline in the capital value of your investment
using the internal rate of return as the discounting factor. If you do not know the
income from the investment, you do not know the rate of return, thus you cannot
calculate economic depreciation.
经济折旧是有点麻烦。除非知道投资所带来的回报,否则根本无法计算投资
的经济折旧。这使许多人感到惊讶,包括一些经济学家。不过折旧的定义确实是
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简单的将内部收益率作为贴现因子时的投资资本的下降。如果不了解投资带来的
回报,那么将无法计算经济折旧。The source of the misunderstanding is that people mix up tax depreciation or
accounting depreciation with economic depreciation. But tax or accounting
depreciation is simply a set of mechanical rules which you do not use when you want
to find the true cost of energy per kWh.
误解的根源在于人们把税项折旧或者账面折旧与经济折旧混淆了。税项折旧
或账面折旧是一种简单的机械规定,在寻找每千瓦时电量的真实成本时是用不
到的。Prices and Costs are Two Very Different Concepts
价格和成本是两个完全不同的概念Many non-economists use the words cost and price as synonyms. They are not. The
price of a product is determined by supply and demand for the product. Many people
naively assume that the price of a product is somehow a result of adding a normal or
reasonable profit to a cost. That is definitely not the case, unless you are running a
Government controlled monopoly.
许多非经济学家将成本和价格作为同义词。事实上并非如此。一种产品的价
格是由其供给和需求决定的。许多人天真地以为,一种产品的价格是在其成本基
础上或多或少的加上利润的结果。绝对不是这样的,除非是在一个政府控制的垄
断型国家。431
Prices of Wind Turbines Cannot be Calculated by Dividing Turnover by Volume
Some people take the turnover figures from manufacturers and divide them by sales
(in MW) in order to obtain a price per MW installed. But the results are complete
nonsense. Some of the reasons why this cannot be done are:
风力机的价格不能由销售额除以销售量来决定。有些人从制造商那里获得销
售额的有关数据,将其除以销售量(单位为兆瓦)就认为是每安装一兆瓦的价
格。但结果是完全错误的。之所以不能这样计算的原因有:1. Some of the manufacturers deliveries are complete turnkey projects including
planning, turbine nacelles, rotor blades, towers, foundations, transformers,
switchgear and other installation costs including road building and power lines.
Other deliveries are nacelles only, or all variations in between. Manufacturers'
sales figures also include service and sales of spare parts.
有些厂商交付的是完整的交钥匙工程,包括规划,风力机的机舱,转轮叶
片,塔架,基础,变压器,开关设备以及其它包括道路建设和电缆的安装成本。
其他制造商可能只提供机舱或者上面所提到的某种产品或设备。制造商的售价也
包括服务费和备件的费用。2. Manufacturers' sales include licensing income, but the corresponding MW are not
registered in company accounts.
制造商的售价包括许可收入,但是相应的“兆瓦”却不会在公司账目上登
记。432
3. Sales may vary significantly between markets for e.g. high wind turbines and low
wind turbines. The prices of different types of turbines are very different.
售价在不同市场之间有着显著区别,例如高的风力机和低的风力机。不同类
型风力机的价格有很大的不同。4. The patterns of sales, types of turbines, and types of contracts vary significantly
and unsystematically from year to year.
销售模式,风力机类型及合同类型每年之间都有很大的区别。Prices should be obtained from price lists. It is useless to make some simple average
of prices from such a list, however, since some turbine models are not sold whereas
others are sold in huge volume. It does not make sense to take an average of prices for
turbines of, say 1,000 kW, even if they have the same tower height. It makes much
more sense to look at the price per square metre rotor area, as explained in a
subsequent section.
价格应该按照价格清单获得。从这样一个列表中做一些简单的价格平均是没
有用的,然而有些风力机模型是不会出售的,而其他的却大量销售。将各种风力
机价格取平均是没有意义的,即使机组模型(例如 1兆瓦的)和出售中的机组
高度一样。而按照叶片的扫风面积来定义价格是有道理的,随后的部分将做解释Productivity and Costs Depend on the Price of Electricity and Not Vice Versa
生产率和成本取决于电力价格,反之却不成立If you look at annual production per square metre rotor area in Denmark, it tends to be
significantly higher than in, say, Germany. That, strictly speaking, has nothing to do
with different wind resources. It is caused by different prices for electricity. In 433
Denmark it is simply not profitable to locate wind turbines in low wind areas, whereas
it is profitable to use low wind areas in Germany due to high electricity prices.
如果是按照每平方米的转轮面积来看年产量的话,那么丹麦要比德国高出
很多。严格来说,这和不同的风资源没有任何关系。这是由于电价的不同造成的
在丹麦,将风力机安装在低风速区很显然是不合适的,但是在德国却是可行的,
因为德国的电价实在太高了。Germany has a very high electricity price for renewables (electricity tariff per kWh of
energy delivered to the grid). You will therefore find that in Germany it is profitable
to equip wind turbines with very tall towers. The high electricity price also makes it
profitable to locate wind turbines in low wind areas. In that case, the most economic
turbines will have larger rotor diameters relative to the generator size than in other
areas of the world.
德国可再生能源的电价是非常高的(每输送到电网 1千瓦时的电量税费)。
因此在德国安装很高塔架的风力机是比较合适的。高电价使得在低风速区安装风
力机也是可行的。在那种情况下,最经济的风力机与世界其他地方的发电机相比
转轮直径大很多。Wind turbines sold on the German market may therefore look more expensive than
they do for other markets, if you look at the price per kW installed (rated) power. But
that is really a very deceptive statistic, because what you really see, are machines
which are optimised for the German low wind sites. The price per square metre rotor
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area located at a given hub height is what matters, not the price per kW installed
power. This is explained in detail in one of the next section below.
因此如果是看每安装 1千瓦(额定)功率的价格,在德国市场上出售的风
力机可能比其他市场上的更加昂贵。但是,这的确是一个非常具有误解的统计,
因为你真正看到的是为德国低风速区优化设计的机组。安装在指定轮毂高度的机
组每平方米转轮面积的价格不是每 1千瓦安装功率的价格。这部分内容在接下来
的一段将做详细介绍。Installation Cost Variation
安装成本的变化You get a similarly deceptive picture when you look at installation costs. The curious
thing is that you do not necessarily have a high cost of generating electricity because
of high installation cost. Quite the contrary: You tend to incur high installation costs
whenever you have a good wind resource (and thus cheap generating costs) in a
remote area,.
在看安装成本时,你会看到一个类似的导致误解的图片。奇怪的是,尽管安
装成本很高,你也不能必然的认为所发的电成本就会很高。恰恰相反:只要在偏
远地区有很好的风力资源(发电成本较低),你往往就需要支付较高的安装成
本。In Wales installation costs tend to be very high - several hundred per cent higher than
in Denmark - despite a very low electricity price. This is simply because there is a lot
435
of wind if you place the wind turbines on top of the nicely rounded Welch hills (see
the hill effect). It is really profitable to build an expensive road through the moors,
and build expensive foundations in order to use the high-wind areas. In other words:
You can afford high installation costs, precisely when you have a good wind resource.
在威尔士,安装成本往往非常高——比在丹麦要高好几倍——尽管电价非
常低。这是因为如果将风力机安装在威尔士的小山顶上(见山丘效应一章),就
会有很大的风。为了利用这些大风区域确实值得在荒野中建立代价昂贵的道路和
基础设施。如果有很好的风资源那就绝对能够支付安装成本。In some cases installation costs include costs for extension of the electrical grid and/or
grid reinforcement. Since the costs of cabling can be quite significant, it matters a lot
whether a wind farm is located next to an existing medium voltage power line (9-30
kV), or far from a power line.
在某些情况下安装成本包括电网的扩大和/或者加固。由于电缆的成本(在
电网优化中)占很大的比例,那么将风电场建立在离已有的中压电网不远的地
方或者远离已有电网对成本的影响还是很大的。Consequently it makes no sense to use average installation costs, if we are not talking
about areas with roughly the same wind climate, the same electricity price per kWh
delivered to the grid, and the same distance to the grid.
因此如果不是研究风气候大致相同、输送到电网电价相同以及到电网距离相
同的地区,那么使用平均安装成本是没有意义的。436
Wind Energy is a Resource Extracting Technology
风能是一种资源提取技术Many people ask: "What is the average cost of wind energy?". That Question is just as
meaningless as "What is the average cost of crude oil?"
很多人问:“风能的平均成本是什么?”。这个问题就像“原油的平均成本是
什么”一样没有意义。In Kuwait the cost may be 1 USD per barrel, in the North Sea, it may be 15 USD per
barrel. The reason why the costs are so different is that it is far more complex to
extract the oil from the North Sea than in Kuwait. It does not make any sense to
average out the cost of oil production in Kuwait and in the North Sea in order to find
some average cost. The average will certainly not be a guide to the price of crude oil!
Even if the market price of oil drops below 15 USD per barrel, it may still pay to
produce oil from the North Sea, what matters in that case is not the average cost per
barrel of oil but the marginal variable cost of extracting another barrel of oil.
在科威特每桶原油的成本可能是 1 美元,而在北海,可能会达到每桶 15 美
元。之所以成本会有如此的不同是因为从北海提取石油远比在科威特提取石油复
杂。因此通过计算科威特石油和北海石油的平均成本以找出石油的平均成本是没
有意义的。这种平均显然不能作为原油的价格指南!即使市场上的石油价格跌破
15 美元一桶,在北海生产石油依然是能够获利的,在这个事例中重要的不是每
桶石油的平均成本而是提取另外一桶石油的可变成本。
Using Statistics from one Area is not a Reliable Guide to Costs in Another Area
437
利用从一个地区统计出来的成本来指导另外一个地区的成本是不可靠的The cost of wind energy in Germany is high, because prices for electricity are high.
The cost of wind energy in the UK is low, because the price of electricity is low. And
of course you get very few wind turbines installed if you have low prices for
electricity, because high wind sites are scarce, and you may not be able to find sites
which are profitable.
德国风力发电的成本很高,因为电价很高。而英国风力发电的成本较低,因
为英国电价低。因为大风地区较少,可能难以找到合适的安装地点,所以如果电
价低的话那么自然安装的风力机就会较少。The price per kW Rated Power is a Very Poor Guide to Investment in Wind Power - the Price per Square Metre Rotor Area matters
在风电中将每千瓦额定功率的价格作为投资指南是不够的—利用每平方米的转轮面积的价格比较合适。Many researchers who are interested in the decline in costs of wind power wish to
study the decline in the price of wind turbines. They therefore ask for an apparently
simple statistic: The price of a wind turbine per kW installed power. That figure is
usually difficult to get hold of, and a very poor guide to cost developments for several
reasons.
很多对如何减小风电成本感兴趣的学者都希望研究如何降低风力机的价格。
因此他们要求一项看似简单的统计:风力机每安装 1千瓦功率的价格。这项数据
通常是很难掌握的,而且以其作为发展风电的投资成本是远远不够的,原因有
(以下)几条。438
It is very difficult to give a single figure for price per kW installed power, because the
price of a turbine varies much more with its rotor diameter than with the rated power
of its generator. The reason is that annual production depends much more on the rotor
diameter than the generator size. Studies which compare the average price per kW
installed power for different technologies are usually misleading, if they include wind
power.
因为价格随转轮直径的变化比随发电机额定功率的变化要明显得多,因此
很难给出每千瓦装机功率的价格。原因是,每年的发电量主要取决于转轮直径的
大小,而非发电机容量的大小。如果他们把风电功率包括进去的话,那些以每安
装 1千瓦功率的平均价格来比较不同技术(的优劣)的研究通常是一种误导。Systematic kW Nonsense - an Example
按照“千瓦”来研究是系统性错误——示例As an example of why it is misleading to use the price per kW rated power for a wind
turbine, compare the annual energy production from two machines from the same
manufacturer, both mounted on a 50 m tower. (The first one is a high wind machine,
the second one a universal machine). You can use the Wind Turbine Power Calculator
to verify the results:
至于为什么使用风力机每安装 1千瓦额定功率的价格是一种误导,我们以
下面的例子加以说明。比较安装在 50米的塔架上的两台产自同一厂家的风力机
的年发电量。(第一台是大功率风力机,第二台是通用机型)。可以使用风力发
电计算器来验证这些结果:439
1. Vestas V39, a 600 kW turbine with a 39 m rotor diameter
维斯塔斯V39,一台 600千瓦转轮直径为 39米的机组2. Vestas V47, a 660 kW turbine with a 47 m rotor diameter
维斯塔斯V47,一台 660千瓦转轮直径为 47米的机组The result is that annual energy production from the second machine is 45.2% higher
than the first machine, despite the fact that the generator is only 10% larger. If you
compare the two rotor areas, however, you may observe that the rotor area of the
second machine is exactly 45.2% larger than the first machine.
结果是,第二台机组每年的发电量比第一台高出 45.2%,尽管发电机容量
只高出 10%。然而,如果比较两个转轮的面积,您就会发现第二台发电机的转
轮面积正好比第一台的大 45.2%。So, if we assume that the price for the second machine is 33% higher than for the first
machine you would get very different results, if you compare
所以,如果我们假设第二台机组的价格比第一台机组的高 33%,就会得到
完全不同的结果,如果我们比较1. The price per kW rated power has increased 21%
每千瓦额定功率的价格已经增长了 21%2. The price per sq m rotor area has decreased 8.4%
每平方米转轮面积的价格下降 8.4%440
3. The price per kWh energy has decreased 8.4%
每千瓦时的发电量价格下降 8.4%New wind turbines are increasingly being built with pitch control rather than stall
control. This means that the generator size can be varied more freely in relation to the
rotor size. In general, there is a tendency to use larger rotor areas for a given generator
size. That means that you will get a completely wrong (overestimated) price
development when you compare the price per kW installed power for old turbines
with new turbines. The relevant price measure is the price per square metre swept
rotor area, not the price per kW installed (rated) power.
新型的风力机越来越多的使用变桨距控制而不是失速控制。这意味着可以更
加自由的改变发电机的容量与转轮尺寸的关系。在一般情况下,有一种趋势是对
给定的发电机容量使用更大的转轮面积。这就意味着如果将旧的风力机和新的风
力机每千瓦的安装价格进行比较,将会得到一个完全错误的(高估)的价格。因
此价格是按照转轮每平方米的扫风面积来计算的,并非每安装 1千瓦(额定)
功率的价格。Mistakes with Capacity Factors
与容量因子有关的错误Analysts are frequently interested in the capacity factor for wind power. The capacity
factor for a generating technology is equal to the annual energy production divided by
the theoretical maximum energy production if the generator were running at its rated
power all the year.
441
分析家们经常关心风力发电的容量因子。一项发电技术的容量因子等于年度
发电量除以理论上的最大发电量,假定发电机常年运行在其额定功率下。Depending on the wind statistics for a particular site, the ideal capacity factor for a
wind turbine is somewhere around 25-30%, because that capacity factor minimises
cost per kWh. It is definitely not desirable to increase the capacity factor for a wind
turbine, as it would be for technologies where the fuel is not free! This apparent
capacity factor paradox is explained more in detail on the page on Annual Energy
Output from a Wind Turbine.
根据一个特定地区的风力状况的统计,风力机理想的容量因子是 25-30%,
因为这样能够最大限度地降低每千瓦时的成本。增加风力机的容量因子是绝对不
可取的,因为这是要付出代价的!这种明显的容量因子的矛盾在风力机年度发
电量一章有更加详细的说明。Capacity factors will be very different for different machines cf. the example above,
but likewise the prices (or costs) of those machines will be very different. In the final
analysis, what counts is the cost per kWh of energy produced, not the capacity factor.
容量因子在不同的机组上有很大的区别,参见上面的例子,但是同样的,
这些机组的价格(或者成本)也很不一样。在后面的分析中,最重要的是每千瓦
时的发电量成本,而不是容量因子。Land Rents Depend on the Profitability of a Project and not Vice Versa
土地租金有赖于项目的盈利,反之不成立442
It is a very common mistake to treat compensation to land owners where the turbines
are placed as a cost of wind energy. Actually, it is only a minor share of the
compensation which is a cost, namely the loss of crop on the area that can no longer
be farmed, plus a possible nuisance compensation in case the farmer has to make
extra turns when plowing the fields underneath the wind turbines.
把对土地拥有者的补偿看做风力机的安装成本是一种很常见的错误。事实上
这种补偿只是成本中很小的一部分,因为(对土地拥有者的)补偿只包括了不
能再种植的地方的农作物损失的补偿,加上对农民在风力机下面耕作时不得不
绕过塔架的补偿。If the compensation exceed what you would normally pay to install a power line
pylon, the excess is really an income transfer, which is quite a different matter to
economists. It is not a cost to society as such, but it is a transfer of income (profits)
from the wind turbine owner to the land owner. Such a profit transfer called a land
rent by economists. A rent payment does not transfer real resources from one use to
another.
如果补偿已经超过了预计的安装电缆塔的费用,那么多出来的部分事实上
是一种收入的转移,这对经济学家而言是完全不同的事情。对社会而言这不是什
么成本,只是收入(利润)从风力机的业主转移到土地拥有者手里。经济学家将
这样的利润转移称为土地租金。租赁费并不是将实际的资源从一个拥有者手里转
移到另一个手里。
443
Some people ask what the normal compensation for placing a wind turbine on
agricultural land is. The answer is, that there is no "normal" compensation. The
compensation depends on the quality of the site. If there is a lot of wind, and there is
cheap grid access nearby, the land owner can bargain for a high compensation,
because the turbine owner can afford it due to the profitability of the site. If there is
little wind, and/or high installation costs, the compensation will just be the nuisance
value of the turbine.
有人问在耕地上安装风力机对农民的规范补偿是什么。答案是,没有“规
范”的赔偿。这种补偿取决于当地的风况。如果当地的风很大,而且附近有很便
宜的电网接入,那么土地所有者将获得很高的补偿,因为好的风况使得风力机
的业主能够负担得起。如果风很小,并且/或者安装成本很高,那么补偿将仅仅
是风力机价值的很小一部分。
Guide to the calculator 计算器指南
Guide to the Wind Energy Economics Calculator
风能经济计算器指南This page is a guide to the Wind Energy Economics Calculator on the next page. It
may sense for you to look at the calculator first, and then click on the question marks
to jump back here and get the full explanation of how it works.
这一章是对下一节出现的风能经济计算器的用法介绍。需要首先看一下计算
器,然后点击问号跳转回来,就可以得到它工作的详细解释。
444
Built-in Examples
内置示例To kick start you to get working right away we have included some data examples for
wind turbines, which you may select from the pop up menu. The offshore example is
taken from the Danish power companies' report on offshore wind turbines.
点击开始按钮开始工作,其中从弹出菜单中会有一些风力机的数据例子供
你选择。海上例子取自丹麦电力公司关于海上风力机的报告。Project Lifetime
项目寿命Danish wind turbines have a design lifetime of 20 years. With offshore wind
conditions (low turbulence) it is likely that the turbines will last longer, probably 25 to
30 years.
丹麦风力机设计寿命为 20年。在近海风况下(低湍流),风力机寿命将会
更长,可能是到 25-30年。Since offshore foundations are designed to last 50 years, it may be interesting to
calculate two generations of turbines on the same set of foundations, possibly with a
repair overhaul after 25 years.
由于海上风力机的底座设计寿命可以持续 50年,在同一个底座上计算两代
风力机的寿命是比较有趣的事情,可能需要在 25年后进行一番大修。Read more on the page on Operation and Maintenance.
阅读运行和维护可以了解更多445
Wind Turbine Price
风力机的价格Prices may vary due to transportation costs, different tower heights, different rotor
diameters etc. You can use the example prices, or you can type a price of your own
directly in the box to the right.
价格会随着运输成本、塔架高度、转轮直径的不同而变化。可以使用示例价格
或者是在右侧框中直接输入价格。Read more on the page What does a Wind Turbine Cost?
阅读什么是风力的成本可以了解更多Installation Cost
安装成本Costs may vary with the location, particularly with costs for road construction and
grid connection. 30% of turbine cost is a fair average for Denmark.
因为安装位置尤其是道路建设和电网连接会使成本有所不同。丹麦风力机
30%的成本处于平均水平上。Read more on the page on Installation Costs.
阅读安装 成本 了解更多内容。Income from Electricity Sales
售电收入This optional data item is interesting for individuals who want to invest in a wind
turbine. You may also include capacity credit, if any. Specify the number of kilowatt
hours you found using the Power Density Calculator, and the tariff (payment) per 446
kilowatt hour. You may also enter an amount directly in the box to the far right in the
form. The data is not needed to compute the cost of electricity.
这种备选的数据项对于想投资风力机的个人是很有意思的。如果需要,您也
可以拥有容量信用。用功率密度计算器制定千瓦小时数及每千瓦小时的价格(付
款)。也可以在表格最右边的边框里直接输入数据。不需要用这些数据计算电力
成本。Read more on the page on Income from Wind Turbines, and the page on Electricity
Tariffs.
阅读从风力机获得的收入和电价了解更多内容。Operation and Maintenance
运行和维护You may include either a fixed amount per year (by typing directly into the box to the
right) or a percentage of the cost of the turbine. Costs could include a service contract
with the manufacturer. You may specify a fixed cost per kilowatt hour instead, if you
wish.
可以确定每年的数目(在右侧框内直接键入)或是风力机成本的百分比。成
本包括和制造商签订的服务合同。可以按照自己的意愿制定一个每千瓦小时的固
定成本。Read more on the page on Operation and Maintenance.
阅读运行和维护了解更多内容。447
Net Present Value
净现值Here you specify the real rate of interest to tell the programme how to evaluate future
income and expenditure.
您需要制定一个真实 利率 来告诉系统怎样估算未来的收入和支出。The Net Present Value of your project is the value of all payments, discounted back to
the beginning of the investment. If the figure is positive, your project has a real rate of
return which is larger than your real rate of interest. If the value is negative, the
project has a lower rate of return.
工程的净现值是所有的支出折现后与原始投资额的差值。如果这个值是正的
说明您的工程实际回报率大于真实利率。如果是负的,工程回报率就比较低。To compute the real rate of return, the programme takes the first payment listed at the
bottom of the calculator (number 01) and divides it by (1+the real rate of interest). It
then divides the next payment (number 02) by (1+the real rate of interest) to the
second power, and so forth, and adds it all up together with the initial investment
(number 00).
为了计算实际的收益率,这个程序将第一次的付款(编号 01)列在计算器
的底部,并将其除以(1+实际利率)。然后将第二次的付款(编号 02)除以
(1+实际利率)的平方,以此类推,最后将所有项与初始投资(编号 00)加在
一起。Real Rate of Return
448
实际收益率The real rate of return tells you the real rate of interest which makes the net present
value of your project exactly zero. In other words, the real rate of return tells you how
much real interest you earn on your investment. (The programme does not use your
real rate of interest for anything, it computes one for you).
实际收益率是使项目净现值为零的实际利率。换句话说,实际收益率就是告
诉您在投资中净赚的实际利率。(这个程序不使用任何东西的实际利率,它只为
你计算一个)。Computing that rate is a bit tricky, since it requires that the programme makes a guess
to find the answer that makes the net present value zero. If it guesses to high, the net
present value becomes negative. If it guesses too low, it becomes positive. But the
programme uses a very clever, blazingly fast technique called Newton-Rapson
iteration which means that the guesses improve dramatically each time. After 5
guesses it has found your answer with 5 digit precision.
计算此利率是一个麻烦的事情,因为需要程序做一个估值使得净现值为零。
如果估值过高,净现值将变为负值,估值过低则为正值。但是该程序使用了一个
非常聪明并且快速的技术称为牛顿拉普森迭代法,使每一次估值都大大改善。经
过五次估计就可找到有五位精度的答案。Electricity Cost per kWh
每千瓦时的电力成本
449
The cost is calculated by finding the sum of the total investment and the discounted
value of operation and maintenance costs in all years. We then divide the result by the
sum of the discounted value of all future electricity production, i.e. we divide each
year's electricity production by (1+i) to the n th power, where n is the period number
(01 to 50. If you have specified an income from electricity sales, that amount is not
used, or more accurately, it is subtracted from all non-zero amounts specified in the
list of payments in period 01 to 50.
成本的计算需要知道每年的总投资额、运行贴现以及维修成本。然后将其除
以未来电力生产的贴现值的总和,即每一年的电力生产除以(1+i)的 n 次方,
其中 n是周期数(01到 50)。如果您已经指定了售电收入,这个值就不需要了。
或者更精确的,从指定的 01到 50的支付列表的所有非零项中将其扣除。Payments
支付款项The payments in these boxes are the results of your specifications above, and they are
used to calculate the net present value and the real rate of return. The boxes are also
used to calculate the cost of electricity after subtracting any income from electricity
sales from all non zero boxes in period 01 to 50.
边框中的款项是您在以前指定的结果,它们是用来计算净现值和实际收益
率的。这些框还用来计算电力成本。电力成本是从电力销售编号 01到 50中所有
非零数值中扣除所有的收入得到的值。
450
Economics calculator 经济学计算器
Wind Energy Economics Calculator
风能经济计算器Do not operate the form until this page and its programme have loaded completely.
Note: Prices and costs are examples only. They may not reflect current market
conditions or local site or installation conditions.
请在页面完全加载后再运行该表格。注意:这里给出的价格和成本只是例子
可能难以反映当时的市场条件或当地场址情况或安装条件。CALCULATOR
Investment with years expected lifetime
wind turbine price
installation costs+
Total investment *
Current Income and Expenditure per Year
Income kWh @ per kWh =
Use % of turbine price for operation &
maintenance
Use per kWh (in present day prices)
Specify total cost (in present day prices) to the
right
-
451
Total Net Income per Year *
Net Present Value @ % p.a. real interest rate
*
Real Rate of Return *** *
Electricity Cost per kWh** Present value per kWh *
Payments, (Used for Net Present Value and Real Rate of Return) **
00 Investment (expenditure, therefore always a minus sign)
01 02 03 04 05
06 07 08 09 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
26 27 28 29 30
31 32 33 34 35
36 37 38 39 40
41 42 43 44 45
46 47 48 49 50
计算器
452
投资 年在预期寿命内
风力机价格
安装成本 +
总投资 *
当前收入及每年支出
收入 kWh @ per kWh =
使用 % 用于运行和维护的风力机价格使用 per kWh (今日价格)
在右侧指定总成本(今日价格)-
每年总净收入 *
净现值 @ % p.a. 实际利率 *
实际收益率*** *
每千瓦时电力成本** 每千瓦时现值 *
付款, (用于净现值和实际收益率计算) **
00 投资 (花费,因此通常为负值)
01 02 03 04 05
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06 07 08 09 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
26 27 28 29 30
31 32 33 34 35
36 37 38 39 40
41 42 43 44 45
46 47 48 49 50
* = Boxes marked with an asterisk cannot be changed directly by the user.
* =标有一个星号的框不能由用户直接更改。** = These boxes is filled out by the programme, but you may change the amounts if
you wish. The calculation of electricity cost per kWh uses the same payments as
above, but the programme subtracts the electricity sales income from all non zero
payment values in the table, year 01 to year 50. If you want to be sure what you are
doing when computing the electricity cost per kWh, you should set the income from
electricity sales to zero.
** =这些框是由程序填写的,但是可以按照自己意愿进行更改。每千瓦时电力成
本的计算使用上述相同的款项,但是该程序中的值是电力销售额减去表格中 01
年度到 50年度所有非零付款额的结果。如果在计算每千瓦时的电力成本时想要
确定自己在做什么,应该将售电收入设置到零。454
*** = To compute the real rate of return you must have entered both expenditures and
income from electricity sales.
*** =计算实际收益率必须同时输入电力销售中的花费和收入。You may experiment by changing the figures in the example below. You can fill in
any box, except the result boxes marked with an asterisk (*). After changing data, use
the tab key, click the Calculate button, or click anywhere on the page outside the field
you have updated to see the results. Click on the question marks for help.
可以通过改变以下算例中的数字做一些实验。可以在任意框中填写数据,除
了标有一个星号的结果栏。更改数据后,使用 TAB键,点击计算按钮,或是点
击所看结果区域外的页面任意处。点击问题按钮寻求帮助。
Economics of offshore wind 海上风力的经济性
Economics of Offshore Wind Energy 海上风电的经济性New Danish Reports on Offshore Wind Energy 关于海上风能的新丹麦报告In 1997 the Danish electrical power companies and the Danish Energy agency
finalised plans for large scale investment in offshore wind energy in Danish waters.
1997年,丹麦电力公司和丹麦能源机构制定了一个关于在丹麦海域大规模
投资风力发电的计划。The plans imply that some 4 100 MW of wind power are to be installed offshore
before the year 2030. Wind would by then cover some 50 per cent of Danish
electricity consumption (out of a total of 31 TWh/year).
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这个计划提出在 2031年以前在近海区域安装 4 100兆瓦的风力机。风力发电
将会涵盖 50%的丹麦用电(超出总值 310亿千瓦时/年)。Improving Economics of Offshore Wind Energy
提高海上风能的经济性On the previous page, the calculator already includes an example showing the
expected average cost of offshore wind energy in Denmark, using presently available
technology.
在前面章节中,计算器已经包含了一个例子,这个例子以目前的可行技术,
给出了丹麦海上风能的预期平均成本。The most important reason why offshore wind energy is becoming economic is that
the cost of foundations has decreased dramatically. The estimated total investment
required to install 1 MW of wind power offshore in Denmark is around 12 million
DKK today, (equivalent to 4 million DEM, or 1.7 million USD). This includes grid
connection etc.
海上风电正在变的经济的最主要原因是基础设施建设的成本有了大幅度下
降。目前安装在丹麦海上 1MW的风能预期总的投资大概是 1200万丹麦克朗。
(相当于 400万德国马克或是 170万美元)。这包括了与电网的连接等。Since there is substantially more wind at sea than on land, however, we arrive at an
average cost of electricity of some 0.36 DKK/kWh = 0.05 USD/kWh = 0.09
DEM/kWh. (5% real discount rate, 20 year project lifetime, 0.08 DKK/kWh = 0.01
USD/kWh = 0.02 DEM in operation and maintenance cost).
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虽然海风比陆地风要大很多,但是目前的电力成本却比较高,为 0.36丹麦
克朗/千瓦时=0.05德国马克/千瓦时=0.09 美元/千瓦时。(5%实际折扣率、20年工
程寿命、运行和维修成本为 0.08丹麦克朗/千瓦时=0.01德国马克/千瓦时=0.02 美
元/千瓦时)。Accounting for Longer Project Lifetime
工程寿命更长的原因It would appear, however that turbines at sea would have a longer technical lifetime, due to lower turbulence.
看来理论上风力机在海上可能会有较长的寿命,因为海上湍流比较低。If we assume a project lifetime of, say, 25 years
instead of 20, this makes costs 9 per cent lower, at
some 0.325 DKK/kWh.
如果我们假设工程寿命是 25年而不是 20年,这会降低 9%的成本,相当于
0.325丹麦克朗/千瓦时。The cost sensitivity to project lifetime is plotted in the accompanying graph, which
was made using the calculator on the previous page.
成本与工程寿命的关系见附图,该图是用前面章节中介绍的计算器得出的。Danish power companies, however, seem to be optimising the projects with a view to
a project lifetime of 50 years. This can be seen from the fact that they plan to require
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50 year design lifetime for both foundations, towers, nacelle shells, and main shafts in
the turbines.
然而丹麦电力公司似乎想把工程寿命优化到 50年。这从他们的计划中能够
看出来,因为他们无论是对基础设施建设、塔架和机舱外壳还是风力机主轴的要
求都是设计寿命达到 50年。If we assume that the turbines have a lifetime of 50 years, and add an overhaul
(refurbishment) after 25 years, costing some 25 per cent of the initial investment (this
figure is purely a numerical example), we get a cost of electricity of 0.283 DKK/kWh,
which is similar to average onshore locations in Denmark.
如果假设风力机是 50年寿命,25年大修一次(翻新),耗资约为初始投资
的 25%(这个数字是纯粹的算例),可以得到的电力成本是 0.283丹麦克朗/千
瓦时,这接近丹麦陆上风电的平均水平。
Employment 就业
Employment in the Wind Industry 风电行业的就业30,000 Jobs Worldwide in 1995 1995年在全球提供了 30000个就业岗位The wind industry in 1995 employed some 30,000 people worldwide. This estimate is
based on a study from the Danish Wind Industry Association, which was published in
1995.
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风电行业 1995年在全球范围内雇佣了将近 3万人。该估计是基于丹麦风力
发电协会在 1995年发表的一项研究报告得出的。The study accounts for both direct and indirect employment. By indirect employment
we mean the people who are employed manufacturing components for wind turbines,
and the people who are involved in installing wind turbines worldwide.
这个调查结果包括直接和间接的就业。间接就业是指其工作是为风力机制造
部件和在全球范围内安装风力机。9,000 Jobs in Denmark
丹麦的 9000个职位The Danish wind industry had some 8500 people employed in 1995. It may be
interesting to see how they are divided between different components:
丹麦风电行业在 1995年雇佣将近 8500 人。了解一下这些人的具体分工还是
蛮有趣的。Component Employment Turbine assembly 3600 Rotor blades 2000 Electronic controllers 700 Brakes, hydraulics etc. 200 Towers 1500 Installation of turbines 300 Other 300 Total 8300
部件 雇佣
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风力机装配 3600
转轮叶片 2000
电控系统 700
刹车,液压系统等 200
塔架 1500
风力机安装 300
其他 300
总数 8300
In reality wind turbine production creates about 50 per cent more jobs, since Danish
manufacturers import many components, e.g. gearboxes, generators, hubs etc. from
abroad. In addition, jobs are created through the installation of wind turbines in other
countries.
实际中生产风力机可以多创造 50%的就业机会,因为丹麦制造商从国外进
口了许多部件,例如齿轮箱、发电机、轮毂等。另外,通过在其他国家安装风力
机也可以创造就业机会。How was the Study done?
研究是如何完成的?You may think we went out and asked the wind turbine manufacturers to get the
figures. Well, we did, but only to check our calculations. The point is, that you are
likely to end up with the wrong answer, if you rely on asking people about something
as complex as job creation throughout the economy. You may see remarkably large
errors in other estimates made as naive back-of-an-envelope calculations elsewhere on
the Web. (Out of courtesy, we won't include the link, here).
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您可能会认为我们是去找风力机生产厂家获得的数据。事实确实如此,但只
是为了验证我们的计算。问题在于对创造就业这样复杂的经济问题如果只是依赖
于求助别人,那么很有可能会获得错误的答案。您可能会发现这份答案与网站上
其他一些数据会有很大的偏差(出于礼貌,这里将不设链接)。Actually, we started very differently using a so called input-output model, which is
what most economists in government service, or central statistical bureaus would do.
In an input output model we actually follow the flow of deliveries from each sector of
the economy to other sectors of the economy. In our case, we have a 117 by 177 table
of deliveries between the sectors, and the statisticians have double checked that they
sum up to the total production in the economy. With this table on may follow sub-sub-
contracting all the way back in the economy in an infinite number of links. (Using a
mathematical technique called matrix inversion):
实际上,我们是从一种完全不同的投入-产出模型开始估计的,在政府部门
工作的经济学家或是中央统计局的人会用到这一模型。在投入产出模型中我们遵
循了各经济部门与其他经济部门之间的人员流动规律。在我们的方法中,各部门
之间有一个 117 乘 177表格形式的人员流动记录,并且统计人员会对其进行重
复检查以确保这些记录加起来与经济总产量相符。有了这个表格,我们就可以在
纷繁复杂的经济环境中根据各种合同来进行统计。(使用的数学方法叫矩阵求
逆)461
How to get Hold of the Study
如何掌握这项研究技术You may download the employment study (44K) in Adobe Acrobat pdf-format for
printing in the original layout on your own printer. To download to a PC: Click the
Download button using the right mouse button. To download to a Macintosh, hold the
mouse button down, and select Save this Link as...
可以下载就业问题研究(44K)Adobe Acrobat pdf 格式,在自己的打印机上
按照原来的格式打印出来。下载到个人电脑上的方法为鼠标右键点击下载按钮。
要下载到苹果机上,请按住鼠标按钮,然后选择保存链接为……
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History of wind energy 风能的历史
Introduction 前言
History of Wind Turbines
风力机的历史Please respect that we have exclusive copyright on all of this web site. You
may quote us, giving proper attribution to the Danish Wind Industry
Association web site www.windpower.org, but it is illegal to use any picture,
plot, graphics or programming on any other web site or in any commercial or
non commercial medium, printed, electronic or otherwise.
请尊重我们对于本网站所拥有的独家版权。您可以引述我们的内容,并以恰当的
方式归引于丹麦风力工业协会网站:www.windpower.org。未经允许即把本网站
中的任何图片、创意、图形或程序用于其它网站、商业或非商业媒体、印刷品、电
子文件等将被视为非法行为。1. A Wind Energy Pioneer: Charles F. Brush
一位风能先驱者:查尔斯 · 弗朗西丝 · 布拉什( Charles Francis Brush ) 2. The Wind Energy Pioneer: Poul la Cour
风能先驱者:保罗 · 拉 · 库尔( Poul la Cour ) 3. The Wind Energy Pioneers - 1940-1950
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风能先锋 – 1940-1950 4. The Wind Energy Pioneers - The Gedser Wind Turbine
风能先锋 – 盖瑟( Gedser )风力机 5. Wind Turbines From the 1980s
20 世纪 80 年代以来的风力机
6. The California Wind Rush
加州“风能潮”7. Modern Wind Turbines
现代风力机8. Offshore Wind Turbines
海上风力机9. Megawatt-Sized Wind Turbines
兆瓦级风力机10. Multi-Megawatt Wind Turbines
多兆瓦级风力机Please note that all images on this web site are the property of the Danish
Wind Industry Association, or the respective copyright holders.
464
请注意,本网站所有图片的版权归属于丹麦风力工业协会,或者相关版权持有
人。
Charles F. Brush 查尔斯 • 弗朗西丝 • 布拉什( Charles Francis
Brush )
A Wind Energy Pioneer: Charles F. Brush
一位风能先驱者:查尔斯•弗朗西丝•布拉什(Charles Francis Brush)The Forgotten Wind Turbine Pioneer被遗忘的风力机先驱者
All photographs on this page copyright © the Charles F. Brush Special Collection, Case Western Reserve University, Cleveland, Ohio本页所有图片的版权归查尔斯·弗朗西斯·布拉什特藏号刊所有,由俄亥俄州克利夫兰市凯斯西储大学发行。
Charles F. Brush (1849-1929) is one of the founders of the American
electrical industry.
查尔斯•弗朗西丝•布拉什(Charles Francis Brush,1849-1929)是美国电
力工业的奠基人之一。He invented e.g. a very efficient DC dynamo used in the public electrical grid,
the first commercial electrical arc light, and an efficient mehod for
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manufacturing lead-acid batteries. His company, Brush Electric in Cleveland,
Ohio, was sold in 1889 and in 1892 it was merged with Edison General
Electric Company under the name General Electric Company (GE).
例如,他曾发明了一台可用于公共电网的高效直流发电机,世界上第一盏商业
电弧灯,以及一种制造铅酸电池的有效方法。1889年,他卖掉了自己在俄亥俄
州克利夫兰市的公司——布拉什电气公司。该公司于 1892年与爱迪生通用电气
公司合并为通用电气公司(GE)。The Giant Brush Windmill in Cleveland, Ohio位于俄亥俄州克利夫兰市的巨型布拉什风车
During the winter of 1887-88 Brush built
what is today believed to be the first
automatically operating wind turbine for
electricity generation.
从 1887年冬到 1888年,布拉什主持建造
了至今被视为是第一台的自动运行风力发
电机。It was a giant - the World's largest - with a rotor diameter of 17 m (50 ft.) and
144 rotor blades made of cedar wood. Note the person mowing the lawn to
the right of the wind turbine.
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这是个庞然大物——也是当时世界上最大的风力机。它的转轮直径达 17米(50
英尺),由 114片雪松木制成的叶片组成。注意到那个在风力机右边修建草坪
的人。The turbine ran for 20 years and charged the batteries in the cellar of his
mansion.
这台风力机运行了 20年,为安装在布拉什庄园地下室里的蓄电池充电。Despite the size of the turbine, the generator was only a 12 kW model. This is
due to the fact that slowly rotating wind turbines of the American wind rose
type do not have a particularly high average efficiency. It was the Dane Poul
la Cour, who later discovered that fast rotating wind turbines with few rotor
blades are more efficient for electricity production than slow moving wind
turbines.
尽管这台风力机很大,但其发电机只有 12kW。这是由于这种慢速旋转的美式风
力机没有特别高的平均效率。丹麦人保罗·拉·库尔(Poul la Cour)后来发现具
有较少叶片且高速旋转的风力机比低速风
力机拥有更高的发电效率。The Scientific American Article About the Brush Windmill《科学美国人》刊载的有关布拉什风车的文章20 December 1890 the journal Scientific
American has a very detailed description
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of the Brush windmill. It is particularly noted for its fully automated electrical
control system.
1890年 12月 20日出版的《科学美国人》刊登了一篇详细介绍布拉什风车的文
章。其中特别指出,这是一个全自动化的电气控制系统。Its principles using solenoids does not change very much with future
generations of wind turbines - until about 1980 when the wind turbine
controllers become equipped with computers.
它所应用的电磁原理在后来的风力机中并没有多大的改变——直到大约 1980
年时,风力机的控制器开始配备了计算机。
Mr. Brush's Windmill Dynamo Scientific American, 20 December 1890 (It is a good idea to click the picture above in order to have it next to this page, and follow the references in the article) “布拉什先生的风车发电机”,《科学美国人》,1980年12月20 日(不妨点击上面的图片,以便获得其原图的链接,并请参阅这篇文章)It is difficult to estimate the effect of an invention on existing practices and
industries. Occasionally a new invention will appear which will greatly affect a
whole range of allied inventions and industries in such a way as to entirely
change time-honored customs, inaugurate new practices and establish new
arts. The commercial development of electricity is a notable example of this.
我们很难估计一项发明对现有做法和产业界的影响。偶尔,一个新发明的出现将
会促进一系列的发明及整个工业界的变革,它能够改变长久以来的习惯,开创
新的实践领域并建立新的艺术。电力的商业开发就是一个显著的例子。468
After Mr. Brush successfully accomplished practical electric illumination by
means of arc lights, incandescent lighting was quickly brought forward and
rapidly perfected. Gas lighting was also improved in various ways.
Simultaneously with these, the electric distribution of power was carried
forward, and important improvements were made in prime movers for driving
dynamos. In this direction much has been done both in steam and water
motors. Wind power has been repeatedly suggested for driving dynamos, but
the adaptation of the windmill to this use seems to have been a problem
fraught with difficulties. Few have dared to grapple with it, for the question not
only involved the motive power itself and the dynamo, but also the means of
transmitting the power of the wheel to the dynamo, and apparatus for
regulating, storing and utilizing the current.
在布拉什先生成功地完成了具有实际使用价值的电光源——电弧灯的发明后,
白炽灯很快被提出并迅速完善,煤气照明也以各种方式得到改进。与此同时,电
能的配送工作也被推进,其中重要的改进在于拖动发电机的原动机。在这方面,
许多工作都与水蒸气和水力发动机有关。风能曾被多次提及用于驱动发电机,但
是让风车适用于这种应用似乎是一个问题,困难重重。很少有人敢于挑战这一难
题,因为这不仅是涉及到动力本身和发电机的问题,还要考虑如何把叶轮收集
到的能量传递给发电机,以及调节装置、储能和怎样使用电流等问题。With the exception of the gigantic windmill and electric plant shown in our
engraving, we do not know of a successful system of electric lighting operated
by means of wind power.
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除了在版画里出现的巨大风车和电厂,我们尚不清楚(是否有)成功地使用了
风能的电力照明系统。The mill here shown, as well as all of the electrical apparatus used in
connection with it, and the very complete system by which the results are
secured, have been designed and carried out according to the plans of Mr.
Charles F. Brush, of Cleveland, Ohio, and under his own personal
supervision. As an example of thoroughgoing engineering work it cannot be
excelled.
这里显示的风车,以及与其相连的所有电气设备,最终确立了整个风力发电系
统。其设计、制造都已经依照俄亥俄州查尔斯·弗朗西丝·布拉什先生的构想,并
在他亲自监督下完成。作为一个精细的工程项目的例子,它再完美不过了。Every contingency is provided for, and the apparatus, from the huge wheel
down to the current regulator, is entirely automatic.
每一个应急的动作,以及仪器——从巨大的转轮到电流调节器,都是完全自动
的。The reader must not suppose that electric lighting by means of power
supplied in this way is cheap because the wind costs nothing. On the
contrary, the cost of the plant is so great as to more than offset the cheapness
of the motive power. However, there is a great satisfaction in making use of
one of nature's most unruly motive agents.
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请读者不要因风力不费分文,就以为风能提供的电照明很便宜。恰恰相反,建造
风电厂的成本是如此之大,以至于抵消并超过了使用便宜的动力所节约的花费。
然而,能够利用自然界最无规律的能量之一本身就是一件给人带来巨大满足感
的工作。Passing along Euclid Avenue in the beautiful city of Cleveland, one will notice
the magnificent residence of Mr. Brush, behind which and some distance
down the park may be seen, mounted on a high tower, the immense wheel
which drives the electric plant to which we have referred. The tower is
rectangular in form and about 60 feet high. It is mounted on a wrought iron
gudgeon 14 inches in diameter and which extends 8 feet into the solid
masonry below the ground level. The gudgeon projects 12 feet above the
ground and enters boxes in the iron frame of the tower, the weight of the
tower, which is 80,000 pounds, being borne by a step resting on the top of the
gudgeon. The step is secured to a heavy spider fastened to the lower part of
the frame of the tower.
在美丽的克利夫兰市,沿着欧几里得大街,人们可以看见布拉什先生华丽的房
子,穿过它后面的院子不远处,建有一座宏伟的高塔,上面巨大的转轮带动着
发电机,这就是我们提到过的风车。这座塔是长方形的,约有 60英尺高,安装
在一根直径为 14英寸的熟铁中轴上。中轴深入地下 8英尺,地上部分足有 12英
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尺,并与塔内的铁制框架相连。塔的总重量达到了 80,000磅。轴的顶端有一架
梯子,固定在塔下部的框架上以确保安全。In the upper part of the tower is journaled the main wheel shaft. This shaft is
20 feet long and 6 1/2 inches in diameter. It is provided with self-oiling boxes
26 inches long, and carries the main pulley, which has a diameter of 8 feet
and a face of 32 inches. The wheel, which is 56 feet in diameter, is secured to
the shaft and is provided with 144 blades, which are twisted like those of
screw propellers. The sail surface of the wheel is about 1,800 square feet, the
length of the tail which turns the wheel towards the wind is 60 feet, and its
width is 20 feet. The mill is made automatic by an auxiliary vane extending
from one side, and serving to turn the wheel edgewise to the wind during a
heavy gale. The tail may be folded against the tower parallel with the wheel,
so as to present the edge of the wheel to the wind when the machinery is not
in use. The countershaft arranged below the wheel shaft is 3 1/2 inches in
diameter, it carries a pulley 16 inches in diameter, with a face of 32 inches,
which receives the main belt from the 8 foot pulley on the wheel shaft. This is
a double belt 32 inches wide. The countershaft is provided with two driving
pulleys each 6 feet in diameter, with a face of 6 1/2 inches, and the dynamo is
furnished on opposite ends of the armature shaft with pulleys which receive
belts from the drive wheels on the countershaft.
塔的上部就是所要介绍的主轮轴。此主轴长 20英尺,直径为 6.5英寸。它配有一
个 26英寸长的自动加油箱,并承担着直径 8英尺,厚 32英寸的主滑轮。转轮固
定在主轴上,其直径达 56英尺,是由 144片扭曲成螺旋桨一样的叶片组成的。
该轮帆的面积约 1800平方英尺,起对风作用的尾巴有 60英尺长,20英尺宽。472
在强风的时候,侧面伸出的辅助风标使转轮可以自动地对着风。尾部可以与转轮
平行地折叠起来。像现在这样,让转轮侧对着风,机器就不会工作。主轴下面安
装的副轴直径 3.5英寸,承担着直径 16英寸,32英寸厚的滑轮,并通过一根
32英寸宽的双带与转轮轴上的主滑轮相连。副轴上有两个厚 6.5英寸,直径为 6
英尺的驱动轮,分别与转轮及发电机的电枢轴用皮带相连。The dynamo, which is on of Mr. Brush's own design, is mounted on a
vertically sliding support and partially counterbalanced by a weighted lever. It
will be seen that the countershaft is suspended from the main shaft by the
main belt, and the dynamo is partly suspended from the countershaft by the
driving belts. In this way the proper tension of the belts is always secured, the
total load on the dynamo belts being 1,200 pounds, and on the main belt
4,200 pounds. The ends of the countershaft are journaled in sliding boxes
connected by equalizing levers which cause both ends of the shaft to move
alike. The pulleys are so proportioned that the dynamo makes fifty revolutions
to one of the wheel. The speed of the dynamo at full load is 500 revolutions
per minute, and its normal capacity at full load is 12,000 watts.
由布拉什先生亲自设计的发电机安装在一个可以垂直升降的支架上,通过一个
杠杆,抵消了发电机的部分重量。我们可以看到,副轴通过主皮带悬挂在主轴上
发电机又通过驱动带半悬挂在副轴上。这样就能保证皮带上总是有合适的张力。
发电机的驱动带上的总负载为 1200磅,主皮带的负载为 4200磅。副轴的两端
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通过均衡杠杆连接在一个滑框上,以便使两端同步旋转。滑轮组的传动比被设为
1:50,即转轮转一周,电动机转 50 周。满载时,发电机的速度是每分钟 500
转,输出功率为 12千瓦。The automatic switching devices are arranged so that the dynamo goes into
effective action at 330 revolutions a minute, and an automatic regulator is
provided which does not permit the electromotive force to run above 90 volts
at any speed. The working circuit is arranged to automatically close at 75 volts
and open at 70 volts. The brushes on the dynamo are rocked automatically as
the load changes. The field of the dynamo is slightly compounded. The
current passes from the dynamo to contact shoes of polished and hardened
steel carried by a crossbar on the tower, which shoes slide on annular plates
surrounding the gudgeon. Conductors extend underground from these plates
to the dwelling house. To guard against extraordinary wind pressure, the
tower is provided at each of its corners with an arm projecting downwardly
and outwardly, and carrying a caster wheel very near but not in contact with
the circular rail concentric with the gudgeon. Ordinarily, the caster wheels do
not touch the rail, but when the wind is very high, they come into contact with
the rail and relieve the gudgeon from further strain.
为了使发电机获得更高效率,以每分钟 330转的额定转速运行,还安装了一套
自动切换装置。一个自动调节器可以保证在任何转速下,发电机的电动势都不会
高于 90伏。工作电路闭合时的额定电压为 75伏,开路时的额定电压为 70伏。
随着负载的变化,电机的电刷会有震动。电机的场所被围了起来。电流从发电机
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流向位于塔架横梁上的抛光硬化的钢质集电靴,电靴在围绕轴线的环形板上滑
动。导线从这些环形板上引出来,经由地下,连接到住宅内。为了抵抗特殊的风
压,塔的四周预装了斜向下的支撑臂,臂的端部带有脚轮。轮子与环绕中轴的铁
轨非常接近,但一般情况下并没有接触。只有当风很大时,轮子才会接触到铁轨
以便减轻中轴所受到的压力。In the basement of Mr. Brush's house there are 408 secondary battery cells
arranged in twelve batteries of 34 cells each; these 12 batteries are charged
and discharged in parallel; each cell has a capacity of 100 ampere hours. The
jars which contain the elements of the battery are of glass, and each cell has
its liquid covered with a layer of "mineral seal" oil, a quarter of an inch thick,
which entirely prevents evaporation and spraying, and suppresses all odor.
The automatic regulating devices are shown in one of the views of our
engraving. At 1 are shown the voltmeters and ammeters employed in
measuring the charging and discharging currents; at 2 is shown a series of
indicators, one for each battery; 3 represents an electrically operated switch
by means of which the current may be turned on or off the house mains by
pressing push buttons in different portions of the house; 4 represents a
ground detector, which is connected with the center of the battery and with the
ground, so that should the conductor upon either end of the battery be
grounded, the fact will be indicated by the movement of the index in one
direction or the other from the zero point of the scale, thus showing not only
that the battery is grounded, but indicating the grounded pole; 5 is a leakage
detector connected up with the lamp circuits, and arranged to show any
leakage from one conductor to the other; at 6 is shown a compound relay for
operating the automatic resistance shown at 7. This resistance is placed
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between the batteries and the house mains, and is arranged to keep the
voltage on the lamps constant at all times. In this device the resistance is
secured by means of powdered carbon placed under varying pressure, the
necessary movement being made by means of hydraulic pressure under the
control of the relays.
在布拉什先生房子的地下室里有共 408块蓄电池,分成 12 组,每组 34块,。
这 12 组蓄电池并连着充放电,每块电池的容量是 100安培小时。装有电池元件
的罐子是玻璃的,每块电池都被 0.25英寸厚的“矿物密封”油覆盖着,防止电
解液蒸发和雾化,并消除了气味。我们的一张版画显示了自动调节装置。1 号显
示的是测量充放电电流用到的电压表和电流表;2 号是一系列指示器,每组电
池一个;3 号代表的是电动开关,在房子的各处按动开关就能控制电流的通断 。
4 号画的是一个接地探测器,它连在电池的电位中点和大地之间,所以当电池
的任意一极发生对地短路时,指针就会向 0刻度或者满刻度方向摆动,不仅能
够检测出电池的对地短路故障,还能判断短路的极性;5 号是漏电检测器,与
电灯线路相连,被用来检测导体间的漏电;6 号是一个复合继电器,用来控制 7
号中的自调节电阻。这个电阻接在电池与房子的电源干线之间,用来保证加在灯
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上的电压恒定。在这个装置中,电阻的阻值是通过给碳粉施加不同的压力调节的
这个压力又是通过继电器控制的液压装置来获得的。The house is furnished with 350 incandescent lights, varying from 10 to 50
candle power each. The lamps most commonly used are from 16 to 20 candle
power; about 100 incandescent lamps are in everyday use. In addition to
these lights there are two arc lights and three electric motors. It is found after
continued use of this electric plant that the amount of attention required to
keep it in working condition is practically nothing. It has been in constant
operation more than two years, and has proved in every respect a complete
success.
这所房子安装了 350盏白炽灯,每盏灯相当于 10到 50 根蜡烛力不等,最常见
的是 16至 20 根蜡烛力,日常使用的白炽灯有 100盏左右。此外,还有两盏弧
光灯和三个电动马达。通过持续的实际运行发现,要保持这个电厂稳定地工作不
需要投入太多的精力。它一直运行了两年多,在各方面都取得了圆满的成功。
Poul la Cour 保罗 · 拉 · 库尔( Poul la Cour )
The Wind Energy Pioneer - Poul la Cour
风能先驱者:保罗·拉·库尔(Poul la Cour)Poul la Cour保罗·拉·库尔
Askov Folk High School still exists. Presently a non-profit association, the Poul la Cour Museum, is trying to collect funds to preserve Poul la Cour's original windmill Photographs © 2000 Poul la Cour Musee阿斯科夫人民高等学校仍然存在。目前保罗·拉·库尔博物馆作为一个非
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营利组织正试图筹集资金,用以保护保罗·拉·库尔的原型风车。 照片版权由保罗·拉·库尔博物馆所有
Poul la Cour (1846-1908) who was originally trained as a
meteorologist was the pioneer of modern electricity
generating wind turbines.
保罗·拉·库尔(Poul la Cour,1846-1908)是现代风力发
电机的先驱,他最初还曾作为一位气象学家。La Cour was one of the pioneers of modern aerodynamics, and built his own
wind tunnel for experiments.
拉·库尔是现代空气动力学的开拓者之一,他还建造了自己的风洞实验室。The picture shows Poul la Cour and his wife Christine at Askov. ( 49K JPEG )
La Cour was concerned with the storage of energy, and used the electricity
from his wind turbines for electrolysis in order to produce hydrogen for the gas
light in his school.
这张图片是保罗·拉·库尔和他的妻子克里斯蒂娜在阿斯科夫拍下的。(49K
JPEG)拉·库尔对储能技术很感兴趣,他用风力机产生的电能电解水以便获得
学校煤气灯所需的氢气。One basic drawback of this scheme was the fact that he had to replace the
windows of several school buildings several times, as the hydrogen exploded
due to small amounts of oxygen in the hydrogen(!)
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他的这项计划存在一个根本性的缺点,以致于他不得不为几个学校更换了好几
次窗户,这是由于他制得的氢气不纯,含有少量氧气,因此会爆炸!Class of 1904 1904年班级合影
La Cour gave several courses for wind electricians each
year at Askov Folk High School. This picture shows the
group graduating in 1904. (124K, JPEG )
拉·库尔每年都会在阿斯科夫人民高等学校开设几门风电课程。
这张照片是 1904年的毕业生合影。(124K, JPEG )
La Cour's Wind Turbines 拉·库尔的风力机
Two of his test wind turbines in 1897 at Askov Folk High
School, Askov, Denmark. 89K, JPEG
1897年,位于丹麦阿斯科夫人民高等学校的两座试验风
力机(89K, JPEG)La Cour founded the Society of Wind Electricians which in 1905, one year
after it was formed, had 356 members.
拉·库尔于 1905年创立了风电师协会,一年后该协会发展到拥有 356名会员。The Journal of Wind Electricity 《风电》杂志
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The world's first Journal of Wind Electricity was also published by Poul la
Cour.
保罗·拉·库尔发行了世界上第一份专门介绍风电的杂志。In 1918 some 120 local utilities in Denmark had a wind
turbine, typically of a size from 20 to 35 kW for a total of
some 3 megawatt installed power.
截止 1918年,约 120个丹麦公共事业单位拥有了自己的风力机,典型容量为
20到 35千瓦,总装机容量为 3兆瓦。These turbines covered about 3 per cent of Danish electricity consumption at
the time. The Danish interest in wind power waned in subsequent years,
however, until a supply crisis set in during World War II.
当时,这些风力机的发电量占到丹麦总耗电量的 3%。随后,丹麦人对于风电的
兴趣逐年减弱,直到二次世界大战期间,一度出现了能源供应危机,风电才又
得到重视。
1940-1956
The Wind Energy Pioneers - 1940-1950
风能先锋:1940 - 1950
The F.L. Smidth Turbines F. L. 斯密特(F. L. Smidth)风力机During World War II the Danish engineering company
F.L. Smidth (now a cement machinery maker) built a
number of two- and three-bladed wind turbines.
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第二次世界大战期间,丹麦的斯密特(F.L. Smidth)工程公司(现在是一家水
泥机械制造商)建造了许多具有两个或三个叶片的风力发电机。Yes, Danish wind turbine manufacturers have actually made two-bladed wind
turbines, although the so-called "Danish concept" is a three bladed machine.
All of these machines (like their predecessors) generated DC (direct current).
没错,丹麦风力机制造商实际上开创了两叶片的风力机,尽管所谓的“丹麦概
念”是三叶片机型。所有这些机器(正像它们的前辈一样)都产生直流电。(43 K, JPEG)
(Photograph © F.L.Smidth & Co. A/S)
This three-bladed F.L. Smidth machine from the island of Bogø, built in 1942,
looks more like a "Danish" machine. It was part of a wind-diesel system which
ran the electricity supply on the island. (22K, JPEG)
1942年,在帮戈(Bogø)岛上建造的这种三叶片斯密特风机看起来更像“丹
麦”型风机。这是岛上风-柴互补发电系统的一部分,该系统给岛上供电。Today, we would probably argue about how the concrete
tower looks, but this machine actually played an
important role in the 1950s wind energy study
programme in Denmark.
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今天,我们也许会就这座混凝土塔的外观展开争论,但是 20世纪 50年代,这
台机器实际上在丹麦的风力发电研究计划中发挥了重要作用。In 1951 the DC generator was replaced with a 35 kW asynchronous AC
(alternating current) generator, thus becoming the second wind turbine to
generate AC.
1951年,人们用一台 35千瓦的三相交流异步发电机(交变电流)取代了原先
的直流发电机,从而成为第二台输出交流电的风力机。(Photograph © F.L.Smidth & Co. A/S)
Johannes Juul 约翰内斯 · 尤尔
The Wind Energy Pioneers: The Gedser Wind Turbine
风能先锋:盖瑟(Gedser)风力机Johannes Juul and the Vester Egesborg Turbines 约翰内斯·尤尔和西埃厄斯堡风力机
The engineer Johannes Juul was one of the first students of
Poul La Cour in his courses for "Wind Electricians" in 1904.
工程师约翰内斯·尤尔是保罗·拉·库尔最早的学生之一,他在
1904年学习了“风能电工”课程。In the 1950s J. Juul became a pioneer in developing the world's first
alternating current (AC) wind turbines at Vester Egesborg, Denmark. (57K
JPEG)
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在 20世纪 50年代,约翰内斯·尤尔作为一名先锋在丹麦的西埃厄斯堡首先开发
出了输出交流电的风力发电机。The Gedser Wind Turbine盖瑟风力机
Gedser is a good, windy area located at the southern tip of the island of Falster in Denmark. The concrete tower of the Gedser turbine is still there after 50 years, although it is now equipped with a modern Danish wind turbine nacelle盖瑟是位于丹麦法尔斯特岛南端的一个地区,拥有很好的风力资源。50年后,盖瑟风力机的混凝土塔仍然矗立着,不过已经配备了丹麦生产
的现代化风力机机舱。
The innovative 200 kW Gedser wind turbine (35K JPEG) was built in
1956-57 by J. Juul for the electricity company SEAS at Gedser coast in
the Southern part of Denmark.
1956-57年,约翰内斯·尤尔在丹麦南部的盖瑟海岸边,为海岸(SEAS)
电力公司建造了创新的单机容量为 200千瓦的风力发电机。The three-bladed upwind turbine with electromechanical yawing and an
asynchronous generator was a pioneering design for modern wind turbines,
although its rotor with guy wires looks a bit old fashioned today.The turbine
was stall controlled , and J. Juul invented the emergency aerodynamic tip
brakes which were released by the centrifugal force in case of over speed.
Basically the same system is used today on modern stall controlled turbines.
The turbine, which for many years was the world's largest, was incredibly
durable. It ran for 11 years without maintenance.
这台三叶片的上风向风力机装有电动偏航系统和交流异步发电机,是现代风力
机的先驱之作,尽管它转轮上的钢丝使它看起来有些老式的样子。该风机采用失483
速控制,约翰内斯·尤尔发明了紧急情况下的叶尖气动刹车,当速度过快时就会
被释放。现代失速型风力机仍然使用基本相同的控制。这台风机许多年来都是世
界上最大的,非常耐用,曾连续运行 11年而不用维修。The Gedser wind turbine was refurbished in 1975 at the request of NASA
which wanted measurement results from the turbine for the
new U.S. wind energy programme.
1975年,在美国航天局(NASA)的要求下,这台风机得到
了翻新,以便为美国新的风能计划提供风机的测量数据。The machine ran for a few years with test measurements after which it was
dismantled. The nacelle and rotor of the turbine are now on display the
Electricity Museum at Bjerringbro, Denmark.
这台机器又运行了几年,进行了一些测试,然后就被拆除了。其机舱和转轮现陈
列于丹麦比耶灵布罗的电力博物馆。(Photographs © the Electricity Museum, Bjerringbro).
The Nibe Turbines 尼伯(Nibe)风力机After the first oil crisis in 1973, interest in wind energy rekindled in several
countries. In Denmark, the power companies immediately aimed at making
large turbines, just like their counterparts in Germany, Sweden, the UK, and
the USA.
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1973年的第一次石油危机以后,好几个国家重新燃起对风能的兴趣。与德国、瑞
典、英国及美国的同行一样,丹麦的电力公司迅速瞄准了大型风力机的制造。In 1979 they built two 630 kW wind turbines, one pitch controlled, and one
stall controlled. In many ways they suffered the same fate as their even larger
colleagues abroad: The turbines became extremely expensive, and the high
energy price subsequently became a key argument against wind energy.
1979年,他们建造了两台 630千瓦的风力机,一台采用桨距控制,另一台采用
失速控制。甚至与国外更大的同行相比,他们在很多方面遭受到了同样的恶运:
风力机变得极其昂贵,风电价格居高不下,这后来成为有关风能开发的争论焦
点。
1980s 20 世纪 80 年代
Wind Turbines From the 1980s
20世纪80年代以来的风力机The Riisager Turbine 里萨厄(Riisager)风力机A carpenter, Christian Riisager, however, built a small 22
kW wind turbine (39K, JPEG) in his own back yard using
the Gedser Wind Turbine design as a point of departure.
He used inexpensive standard components (e.g. an
electric motor as generator, and car parts for gear and
mechanical brake) wherever possible.
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然而,作为一个木匠兼基督徒的里萨厄在自家的后院建了一台 22千瓦的小型风
力发电机。他参考了盖瑟风力机的设计,并尽可能地使用廉价的标准件(如用电
动机作为发电机,汽车使用的齿轮箱和机械刹车系统)。Riisager's turbine became a success with many private households around
Denmark, and his success gave the present day Danish wind turbine
manufacturers their inspiration to start designing their own wind turbines from
around 1980.
里萨厄风力机成功地在丹麦的许多私人家庭中得到推广。他的成功也激发了当今
的风机生产厂商从 1980年左右开始设计制造自己的风力机。(Photograph © 1996 Copyright The Electricity Museum, Bjerringbro,
Denmark).
Competing Turbine Designs风力机的另一种可能
Picture from the secret testing grounds of Vestas Wind Systems in 1979: The engineer Léon Bjervig next to his 12 kW 7.3 m rotor diameter Darrieus "biplane" machine. Picture © BTM Consult 1979图 片 显 示 的 是 1979 年 维 斯 塔 斯(Vestas)公司在其秘密试验场的新型风力发电系统:工程师莱昂·布杰唯奇
(Léon Bjervig)站在他的打蛋形“双翼飞机”旁,这台风机转轮直径为 7.3米,容量为12千瓦。
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Some designs, including the Riisager design were partly based on solid
experience from the classical Gedser wind turbine , or classical slow moving
multi-bladed American "wind roses", others were more revolutionary including
vertical axis Darrieus machines , machines using flaps for power control , or
hydraulics for the transmission system, etc. etc. Most machines were very
small by today's standards, usually 5 to 11 kW.
包括里萨厄型在内的一些风力机设计,都是部分地建立在古典盖瑟风力机或慢
速旋转的美国多叶片式风机——“风玫瑰”扎实的实践基础之上的。另一些设计
则更具有革命性,例如垂直轴的打蛋形风力机、用副翼控制功率的机器、或者用
液压的传动系统等。以今天的标准来看,这些机器大部分都非常小,通常只有 5
到 11千瓦。The Tvind 2 MW Machine2兆瓦的 Tvind型风机One important exception to the rule of small machines
was the Tvind 2 MW machine, a fairly revolutionary
machine, (in a political sense, too, having been built by
idealist volunteers, practising gender quotas and other
politically correct activities, including waving Chairman
Mao's little red book.) The machine is a downwind machine with 54 m rotor
diameter running at variable speed with a synchronous generator, and indirect
grid connection using power electronics. The machine is still running nicely.
打破了小风机规律的一个重要的例外是 2兆瓦 Tvind型风机,一台完完全全革
命的机器。这是台下风向的机器,转轮直径达 54米,可以工作在不同的风速下。487
它有一部交流同步发电机,并通过电力电子设备与电网间接相连。这台机器至今
仍运转良好。(Photograph Soren Krohn © 1998 DWIA)
Early Danish wind turbine development was thus a far cry from simultaneous
government sponsored research programmes on very large machines in
Germany, USA, Sweden, the UK, or Canada.
与同时代的德国、美国、瑞典、英国或加拿大等政府赞助的大型风力机研究计划
相比,丹麦早期有关风力机的发展相距甚远。In the end, improved versions of the classical, three-bladed upwind design
from the Gedser wind turbine appeared as the commercial winner of this wild
competition, but admittedly not without a number of wreckages, mechanical,
and financial.
最后,经典的三叶片、上风向式盖瑟风力机的改进型从激烈竞争中脱颖而出,取
得了商业成功。但是不可回避的是它也存在一些缺点,既有机械结构方面的也有
经济方面的。Risoe National Laboratory 里索(Risoe)国家实验室Risoe National Laboratory was really born to become the Danish answer to
Los Alamos, i.e. the national centre for nuclear research. Today it is far better
known for its work on wind energy.
488
里索国家实验室的组建初衷实际上是为了成为丹麦的洛斯阿拉莫斯国家实验室,
即国家核能研究中心。今天,它却因其在风能方面的工作而更加闻名于世。Risoe National Laboratory's Department of Wind Energy and Atmospheric
Physics has a staff of some 100 people working on basic research into
aeroelastics , i.e. the interaction between aerodynamics and structural
dynamics, on wind turbine technology , and wind resource assessment. It also
has a separate, small, commercial activity dealing with type approval of wind
turbines.
里索国家实验室的风能与大气物理学部有约 100名研究者,他们的工作包括气
动弹性力学领域的基础研究,即空气动力学和结构动力学之间的相互作用;风
力发电机组技术;风能资源评估。它也有一个独立的,小型商业活动,负责风力
机组的型式审批。Risoe was originally founded with this last purpose in mind, when the Danish
Government instituted a support programme for the erection of wind turbines
in Denmark. In order to protect the buyers of wind turbines (and their
surroundings) the Government required that all supported wind turbines be
type approved for safety. The strict safety regulations (including requirements
for dual braking systems) indirectly helped developing safer and more reliable
wind turbines. (The support programme was abandoned in 1989).
里索有关最后这一点的创意,最初来源于丹麦政府所提出的一项旨在促进风力
机发展的支撑计划。为了保护风力机用户(以及它们周边地区),政府要求所有
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受到支持的风力机都是安全的。这项严格的安全法规(包括要求安装双制动系
统)间接地有助于开发更安全、更可靠的风力机。(该支撑计划于 1989年被终
止。)Bonus 30 kW Bonus - 30千瓦型风力机The Bonus 30 kW machine (21K, JPEG) manufactured
from 1980 is an example of one of the early models
from present day manufacturers.
1980年生产的 Bonus - 30千瓦型风力机可以作为当今
风机生产商早期模式的一个例子。Like most other Danish manufacturers, the company was originally a
manufacturer of agricultural machinery.
和丹麦的其他许多风机生产商一样,这家公司最初是生产农业机械的。The basic design in these machines was developed much further in
subsequent generations of wind turbines.
这些风机的基本设计得到了进一步的发展,并被用于新一代的风力机。(Photograph copyright Bonus Energy A/S).
The great wind rush 浩大的风能潮
The Great California Wind Rush
声势浩大的加州风能潮490
Nordtank 55 kW
The 55 kW generation of wind turbines
which were developed in 1980 - 1981
became the industrial and technological
breakthrough for modern wind turbines.
1980至 1981年间开发的 55千瓦风力机
代表了现代风电工业与技术的突破。The cost per kilowatt hour (kWh) of electricity dropped by about 50 per cent
with the appearance of this generation of wind turbines. The wind industry
became much more professionalised, and the parallel development of the
European Wind Atlas Method by Risoe National Laboratory was extremely
important in lowering kWh costs.
随着这一代风力机的出现,每千瓦时(kWh)电能的成本下跌了约 50%。风电
行业变得更加专业化。与此同时,里索国家实验室倡导的欧洲风能图谱计划
(European Wind Atlas Method)对降低风能开发成本起到了重要的作用。The picture shows a particularly imaginative way of siting these Nordtank 55
kW wind turbines (43K, JPEG), on a harbour pier at the town of Ebeltoft,
Denmark. Red tipped rotor blades have disappeared completely from the
market since then, after it was discovered that birds do not fly into the rotors
anyway.
491
图片显示了一个极富想象力的选址创意:丹麦埃埃贝尔托夫特镇的海港码头。人
们在这上面树立了Nordtank公司的 55千瓦风力机。市场上的风机也不再具有涂
成红色的叶片尖部,因为人们发现鸟类根本不会撞上转轮。(Photograph copyright © 1981 NEG Micon A/S)
The Great California Wind Rush 声势浩大的加州风能潮Literally thousands of these machines
were delivered to the wind programme in
California in the early eighties. The Micon
55 kW (69K, JPEG) is one example of
such a machine, delivered to one huge
park of more than 1000 machines in
Palm Springs, California.
从字面统计来看,上世纪 80年代又数以千计的风力机被交付给了加州的风能计
划。Micon公司的 55千瓦型风机就是其中的一个例子。美国加利福利亚州的棕榈
泉公园安装了超过一千台这种型号的风力机。Having started series manufacturing of wind turbines about 5 years earlier,
Danish manufacturers had much more of a track record than companies from
other countries. About half of the wind turbines placed in California are of
Danish origin.
由于丹麦的风力机制造商比其他国家的制造商要早 5年开始进行系列化的生产,
因此拥有更多的业绩。安装在加州的风力机约有一半是丹麦造的。492
The market for wind energy in the United States disappeared overnight with
the disappearance of the Californian support schemes around 1985. Since
then, only a tiny trickle of new installations have been commissioned,
although the market seems to have been picking up, lately. Germany is now
the world's main market, and the country with the largest wind power
installation.
1985年前后,受加州撤销支持计划的影响,美国的风能市场在一夜之间就消失
了。从那时起,只有少量的新机器投产,然而最近的市场又有复苏的迹象。德国
目前拥有世界上最主要的风电市场,以及最大的风电装机容量。(Photograph copyright NEG Micon A/S)
Modern wind turbines 现代风力机
Modern Wind Turbines
现代风力机Denmark has (in 2003) around 3,000 MW wind power, which is supplied by
approximately 5,500 wind turbines. Individuals and cooperatives own around
80% of the capacity.
截止 2003年,丹麦拥有约 550台风力机,总装机容量约 3000兆瓦。其中 80%
的容量属于私人或者合作所有。Avedøre Holme, Denmark
493
The picture shows the Avedøre Wind Farm, just 5 kilometres from the city
centre of Copenhagen, Denmark. The 12 Bonus 300 kW wind turbines, (and
one 1,000 kW power company test wind turbine) are located next to a 250
MW coal-fired power plant.
这张图片显示的是距丹麦首都哥本哈根市中心 5公里处的 Avedøre风力发电场。
这里共有 12台 Bonus - 300千瓦风力机、一台 1兆瓦的电力公司的试验风力机
和一座 250兆瓦的燃煤发电厂。(Photograph Søren Krohn, © 1997 DWIA) (48K, JPEG)
Large Onshore Wind Farms大型陆上风力发电场
Rejsby Hede wind farm consist of 40 turbines from
Bonus Energy each of 600 kW. The turbines were
erected in 1995 near Tønder in southern Jutland.
Totalling 24 MW it was the largest wind farm in
Denmark at the time.
494
1995年建成的赖斯比·合德风电场装有 Bonus能源公司的 40台 600千瓦型风力
机,位于日德兰半岛南部的通纳(Tønder)附近。它以 24兆瓦的总装机容量而
成为当时丹麦最大的风电场。Today the largest onshore wind farm in Denmark is Syltholm on the southern
island Lolland. The farm consist of 35 NEG Micon 750 kW turbines i.e. a total
capacity of 26,25 MW.
如今,丹麦最大的陆上风电场是位于南部洛兰岛(Lolland)的 Syltholm风电场。
该风电场拥有 35台 NEG Micon公司的 750千瓦风力机,总装机容量 26.25兆
瓦。(Photograph Soren Krohn, © 2000 DWIA) (252 K, JPEG)
Offshore wind turbines 海上风力机
Offshore Wind Turbines
海上风力机Offshore wind energy is a promising application of wind power, particularly in
countries with high population density, and difficulties in finding suitable sites
on land. Construction costs are higher at sea, but energy production is also
higher.
495
海上风能有巨大的应用前景,特别是对于人口密度很高的国家,通常这些国家
难以寻找到合适的场址建造陆上风电场。在海上建风电场成本比较高,但同时也
会带来更大的产量。The largest offshore wind farms in Denmark are Horns Rev by the west coast
of Jutland and Nysted close to Lolland – 160 and 158 MW respectively. A
tendering procedure for new offshore wind farms will be commenced in late
2003.
丹麦最大的两座海上风电场是位于日德兰半岛以西的霍恩斯·冯(Horns Rev)
风电场和接近洛兰岛的奈斯特德(Nysted)风电场,装机容量分别为 160和
158兆瓦。新的海上风电场招标程序将于 2003年底实行。The Danish energy plan, Energi21, from 1996 set up a target for 4,000 MW
offshore wind power in 2030. These 4,000 MW are expected to produce 13.5
TWh per year equivalent to 40% of the Danish electricity consumption.
根据 1996年开始实施的名为“Energi21”的丹麦能源计划,到 2030年丹麦要
建成 4000兆瓦的海上风电。预计每年产生 13.5万亿瓦小时的电能,这将相当于
丹麦 40%的用电量。You can read more about offshore wind turbines in Research in Offshore
您可以通过海上风电研究了解到更多关于海上风力机的内容:
Nysted Offshore Wind Farm
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奈斯特德海上风力发电场Nysted offshore wind farm is located 10 km south of Lolland on Rødsand Bank奈斯特德海上风电场位于洛兰岛以南 10 公里处的勒兹沙洲海岸(Rødsand Bank)
The most recent large offshore farm is Nysted
Offshore Wind Farm at Rødsand built in 2003.
The wind farm is located app. 10 km south of the
town of Nysted on Lolland and consists of 8 rows
with 9 turbines each. The total power of the 72
wind turbines each of 2.3 MW thus reaches 165,5 MW. The annual electricity
production of the wind farm is 600GWh, enough to supply 145,000 (Danish)
households. The wind turbine towers are about 70 m tall, and the rotor blades
41 m long. The picture is from the initial phase of the installation.
最新的大型海上风电场是 2003年在勒兹沙洲(Rødsand)建成的奈斯特德风
电场。该电场在洛兰岛的奈斯特德镇以南约 10公里处,有 8行,每行 9台的风
力机。这 72台风力机每台 2.3兆瓦,共计 165.5兆瓦,年发电量为 6千亿瓦小
时,足够供应 14.5万户丹麦家庭使用。风力机高约 70米,转轮的叶片有 41米
长。这张图片显示的是风力机安装的初始阶段。 Learn more at www.nystedwindfarm.com
了解更多详情请登陆www.nystedwindfarm.com
(Photograph Jakob Holst, © 2003 DWIA)
497
Horns Rev – Denmark's Largest Wind Farm
霍恩斯·冯(Horns Rev)——丹麦最大的风电场Horns Rev is situated of the coast of, Blåvandhuk, the most western point of Denmark
霍恩斯·冯风电场位于丹麦最西端 Blåvandhuk的海岸边。The largest wind farm in
Denmark is the offshore wind farm of
Horns Rev, which was completed in
2002. It is situated in the North Sea,
14-20 km off the coast of Jutland. With
its 80 Vestas 2MW turbines, the wind
farm has a total capacity of 160 MW. That makes it the largest offshore wind
farm in the world today (2003). The farm supplies the equivalent of 150,000
(Danish) households. The larger production compared to Nysted is due to
better wind conditions.
丹麦最大的风电场是 2002年建成的霍恩斯·冯海上风电场。它位于离日德兰半岛
14-20公里远的北海中,装有 80台 Vestas公司的 2兆瓦型风力机,总装机容
量为 160兆瓦,是世界上最大的海上风电场(截止 2003年)。该风电场发电量
相当于 15万户丹麦家庭的使用量。因为有更好地风力资源,所以产量比奈斯特
德风电场大一些。Learn more at www.hornsrev.dk
了解更多详情请登陆www.hornsrev.dk
(Photograph Claus Bøjle Møller, © 2003 DWIA)
498
Samsø
珊索岛Samsø offshore wind farm is located 3,5 km south of the island Samsø珊索岛海上风电场位于珊索岛以南 3.5公里
The energy consumption of the small Danish island Samsø is more than
100% matched by local production of
renewable energy. A major reason for
this is remarkable fact is a locally
owned offshore wind farm consisting of
10 Bonus 2,3 MW turbines.
珊索岛是丹麦的一个小岛,岛上能源消耗却有超过 100%是由当地的可再生能
源提供的。这是一个了不起的事实,主要原因是当地拥有一个海上风电场,装有
10台 Bonus公司 2.3兆瓦型风力机。See online production data at www.samsohavvind.dk/windfarm
获取在线生产数据请访问www.samsohavvind.dk/windfarm
(Photograph Søren Krohn, © 2003 DWIA)
Middelgrunden
米德尔格兰特 The urban offshore wind farm Middelgrunden is located close to the port of Copenhagen米德尔格兰特是一座靠近哥本哈根港口城市的海上风力发电场
499
Middelgrunden is located 2 km off shore east of Copenhagen. It consists of 20
Bonus 2 MW wind turbines arranged to form an arch. With a total power of 40
MW the wind farm can generate 90 TWh a year. That is equivalent to the
annual electricity consumption of 20,000 (Danish) households or three per
cent of the total electricity consumption of Copenhagen.
米德尔格兰特风电场位于哥本哈根以东 2公里的海面上。它安装了 20台 Bonus
公司的 2兆瓦型风力机,这些风机排列成了一个弧形。这座风电场总装机容量为
40兆瓦,年产 90万亿瓦小时电能,这相当于 2万个丹麦家庭一年的用电量,
或者哥本哈根年用电量的 3%。Learn more at www.middelgrunden.dk
要了解更多请访问www.middelgrunden.dk
(Photograph Søren Krohn, © 2000 DWIA)
Tunø Knob
图尼奥布The world's second offshore wind farm is located between the Jutland peninsula and the small island of Tunø in Denmark在丹麦的日德兰半岛与图尼奥布小岛之间坐落着世界第二大的海上风电场
The Tunø Knob offshore wind farm (36K, JPEG) in the Kattegat Sea off the
Coast of Denmark was built in 1995 by the utility company Midtkraft.
The picture shows the construction work with a floating crane.
500
图尼奥布海上风电场位于卡特加特海峡附近海域,于 1995年由Midtkraft公共
事业公司修建。这张图片显示的是浮式起重机正在进行吊装工作。The Wind farm consists of 10 Vestas 500 kW pitch controlled wind turbines.
这个风电场拥有 10台维斯塔斯公司的 500千瓦变桨风力机。The turbines were modified for the marine environment, each turbine being
equipped with an electrical crane to be able to replace major parts such as
generators without the need for a floating crane.
这些风力机根据海上环境进行了改进,每台风机都配备有一台电动起重机,这
样在没有浮式起重机的情况下,也能够对风机的主要部件(如发电机)进行更
换。In addition, the gearboxes were modified to allow a 10 per cent higher
rotational speed than on the onshore version of the turbine. This will give an
additional electricity production of some 5 per cent. This modification could be
carried out because noise emissions are not a concern with a wind park
located 3 kilometres offshore from the island of Tunø, and 6 kilometres off the
coast of the mainland Jutland peninsula.
另外,变速箱也进行了改进,以便允许其转速比陆上型的高出 10%。这将使风
力机的发电量多出约 5%。这项改进得以顺利实施是因为,在离图尼奥岛 3公里,
离日德兰半岛 6公里的海上,不存在噪音问题。
501
The park has been performing extremely well, and production results have
been substantially higher than expected, cf. the page on offshore wind
conditions.
这个电场一直运行良好,其实际产量大大高于预期,参照海上风能资源一节。(Photograph copyright Vestas Wind Systems A/S)
Vindeby
温讷比 The world's first offshore wind farm is located North of the island of Lolland in the Southern part of Denmark世界上第一个海上风电场位于丹麦南部的洛兰岛以北海域
The Vindeby wind farm (32K, JPEG) in the
Baltic Sea off the coast of Denmark was built in
1991 by the utility company SEAS.
温讷比风电场位于丹麦的波 罗的海海域,于
1991年由 SEAS公共事业公司修建。The wind farm consists of 11 Bonus 450 kW stall controlled wind turbines, and
is located between 1.5 and 3 kilometres North of the coast of the island of
Lolland near the village of Vindeby.
该风电场安装了 11台 450 kW Bonus公司的失速型风力机,位于距洛兰岛北岸
的温讷比村附近 1.3到 3公里远的海域。The turbines were modified to allow room for high voltage transformers inside
the turbine towers, and entrance doors are located at a higher level than
502
normally. These same modifications were carried over to the subsequent
Tunø Knob project.
这些风力机也进行了改进,以便塔内能够容下高电压变压器,并且大门比通常
的要高。接下来的图尼奥布工程也进行了相同的改进。Two anemometer masts were placed at the site to study wind conditions, and
turbulence, in particular. A number of interesting results on offshore wind
conditions have been obtained through these studies which were carried out
by Risø National Laboratory.
现场还特别地安装了两个风速计,以研究风况和湍流。通过这些研究,里索国家
实验室得到了一些有关海上风能资源的有趣结果。The park has been performing flawlessly.
这个风电场表现得完美无缺。Electricity production is about 20 per cent higher than on comparable land
sites, although production is somewhat diminished by the wind shade from the
island of Lolland to the South.
尽管因南边洛兰岛的遮挡,风力有所减弱,但这个风电场的发电量还是比陆上
风电场高出约 20%。(Photograph copyright Bonus Energy A/S)
Megawatt turbines 兆瓦级风力机
Megawatt-Sized Wind Turbines503
兆瓦级风力机Nordtank 1500
The prototype of the NEG Micon 1500 kW Turbine (35K
JPEG) was commissioned in September 1995.
这张图片显示的是 NEG Micon公司于 1995年制造的 1.5兆
瓦风力机。The original model had a 60 metre rotor diameter and two 750 kW generators
operating in parallel.
原型机有一个直径为 60米的转轮和两台并联运行的 750千瓦发电机。The most recent version is a 1,500/750 kW model (with two 750 kW
generators) with a 64 metre rotor diameter.
最新的型号是 1,500/750 kW,具有两台 750千瓦的发电机和一个直径为 64米
的转轮。The photograph was taken at the Tjaereborg site in the Western part of
Denmark near the city of Esbjerg.
这张图片拍摄于丹麦西部埃斯比约市附近的切勒堡风场。(Photograph © 1995 NEG Micon A/S 1996)
Vestas 1.5 MW
The Tjaereborg test site for megawatt turbines is located in Western Denmark near the city of Esbjerg兆瓦级风力机的试验风电场位于丹麦西部的埃斯比约市附近
504
The prototype of the Vestas 1500 kW Turbine (51K JPEG) was commissioned
in 1996.
维斯塔斯公司的 1.5兆瓦原型风力机建于 1996年。The original model had a 63 metre rotor diameter
and a 1,500 kW generator.
最初的型号拥有一个直径为 63米的转轮和一台 1.5
兆瓦的发电机。The most recent version has a 68 metre rotor
diameter and a dual 1650/300 kW generator.
最新的型号拥有一个直径为 68米的转轮和 1650/300千瓦的双电机。The picture shows the nacelle being hoisted by a crane.
图为起重机在吊装机舱。In the background to the left you may see the ELSAM 2 MW test turbine (on a
concrete tower), and the NEG Micon 1500 kW a bit farther in the background.
At the far left you can catch a glimpse of a Bonus 750 kW turbine (the most
recent version is a 1 MW turbine).
在左边你可以看到 ELSAM公司的 2兆瓦风力机(混凝土塔),再远一点是
NEG Micon公司的 1.5兆瓦机组,在左边的远处,可以隐约看见 Bonus公司的
750千瓦机组(最新的型号是 1兆瓦的)。(Photograph © 1996 Vestas Wind Systems A/S 1996)
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The Future for Megawatt-Sized Turbines 兆瓦级风力机的发展趋势The megawatt market really took off in 1998. Since then, it has been clear that
the market trend is towards bigger projects with bigger wind turbines.
兆瓦级风力机市场真正起飞于 1998年。从那时起,市场趋势才越来越清晰,即
向着更大的项目、更大的风力机发展。Megawatt-sized machines will be ideal for offshore applications, and for areas
where space for siting is scarce, so that a megawatt machine will exploit the
local wind resources better.
兆瓦级的风力机是海上风电的理想选择,而且海上的选址空间有限,因此兆瓦
级的风力机将能更充分地利用当地的风能资源。
Multi mega machines 多兆瓦级风力机
Multi-Megawatt Wind Turbines
多兆瓦级风力机NEG Micon 2 MW
The prototype of the NEG Micon 2 MW
turbine (1024 x 768 pixels, 132K
JPEG) was commissioned in August
1999. It has a 72 m (236 ft.) rotor
diameter. In this case (Hagesholm,
Denmark) it is mounted on a 68 m
tower. In the background you see the
foundations for two sister machines. The turbine is intended for offshore
applications.
506
NEG Micon公司的 2兆瓦原型机建于 1999年 8月。它有一个直径为 72米
(236英尺)的转轮,安装在 68米高的塔上。从图片的背景中可以看到两座姊
妹机的塔架基础。这种风机计划用于海上项目。From the outside it resembles the 1500 kW NEG Micon machine so much,
that you'd have to see the turbine in its stopped state (with the blades pitched
out of the wind) in order to notice the difference: The rotor blades are
pitchable, since the machine has active stall power control, whereas its 1500
kW cousin has passive stall power control.
从外观上看,它与 NEG Micon公司的 1.5兆瓦机型机器相似,所以必须等到停
机(桨叶切出)时才能仔细观察出其区别:2兆瓦机型具有主动失速控制功能,
因此叶片的桨距可控,而 1.5兆瓦机型是被动失速控制。(Aerial photograph Soren Krohn © 1999 DWIA)
Bonus 2 MW
The prototype of the Bonus 2 MW
turbine (88 K) was commissioned
in the fall of 1998. It has a 72 m
(236 ft.) rotor diameter. In this
case (Wilhelmshaven, Germany)
it is mounted on a 60 m tower.
The turbine is intended for
offshore applications, and has Combi Stall® power control (Bonus trademark
for active stall power control). The machine resembles the Bonus 1 MW and
1.3 MW machines considerably.
507
Bonus公司的 2兆瓦原型机建于 1998年秋。它的转轮直径为 72米(236英尺)
这是安装在德国威廉港的一个例子,其塔高 60米。这种风机计划用于海上风电,
并采用了“Combi Stall®”功率控制技术(Bonus公司主动失速控制的商标),
类似于 Bonus公司的 1兆瓦和 1.3兆瓦机型。(Aerial photograph Soren Krohn © 1999 DWIA)
Nordex 2,5 MW
The prototype of the Nordex 2,5 MW turbine (132 K) was
commissioned in the spring of 2000. The rotor diameter of
the wind turbine is 80 m. The image shows the prototype
at Grevenbroich, Germany, which has a 80 m tower. The
turbine has pitch power control.
恩德(Nordex)公司的 2.5兆瓦原型风力机建于 2000年春。
其转轮直径为 80米。这张图片显示的是位于德国格雷文布罗赫的原型机。这种
风力机具有变桨控制功能。(Photo © 2000 Nordex)
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Wind energy manual 风能手册
Index 索引
Wind Energy Reference Manual
风能参考手册1. Wind Energy Concepts
风能概念1 Unit Abbreviations
缩略语2 Wind Speeds
风速3 Wind Speed Scale
风速表4 Roughness Classes and Roughness Lengths
粗糙度等级和粗糙尺度5 Roughness Class Calculator
粗糙度等级计算器6 Roughness Classes and Roughness Length Table
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粗糙度等级和粗糙尺度对照表7 Density of Air at Standard Atmospheric Pressure
标准大气压下的空气密度8 Viscosity of air
空气粘度9 Power of the Wind
风功率10 Standard Wind Class Definitions (Used in the U.S.)
标准风力等级(美国用)2. Energy and Power Definitions
能量和功率的定义1 Energy
能量2 Energy Units
能量单位3 Power
功率4 Power Units
510
功率单位3. Proof of Betz' Law
贝兹定律的证明4. Wind Energy Acoustics
风能声学1 dB(A) Sound Levels in decibels and Sound Power in W/m 2
声级(分贝 dB)和声功率(W/m2)2 Sound Level by Distance from Source
声源距离对声级的影响3 Adding Sound Levels from Two Sources
两个声源的声级相加
4 How to add sound levels in general
声级相加的一般方法5. Wind Energy and Electricity
风能与电力1 Three Phase Alternating Current
三相交流电2 Connecting to Three Phase Alternating Current
511
与三相交流电相连3 Electromagnetism Part 1
电磁学 第 1部分4 Electromagnetism Part 2
电磁学 第 2部分5 Induction Part 1
电磁感应 第 1部分6 Induction Part 2
电磁感应 第 2部分6. Wind Energy, Environment, and Fuels
风能、环境与燃料1 Energy Content of Fuels
燃料的能值2 CO 2 -Emissions from Fuels
从燃料中排放的CO2
7. Bibliography
参考文献8. Wind Energy Glossary
512
风能词汇
Wind energy concepts 风能概念
Wind Energy Reference Manual Part 1: Wind Energy Concepts
风能参考手册 第1部分:风能概念1. Unit Abbreviations
单位缩写2. Wind Speeds
风速3. Wind Speed Scale
风速等级4. Roughness Classes and Roughness Lengths
粗糙度等级与粗糙尺度5. Roughness Class Calculator
粗糙度等级计算器6. Roughness Classes and Roughness Length Table
粗糙度等级和粗糙尺度对照表7. Density of Air at Standard Atmospheric Pressure
513
标准大气压下的空气密度8. Viscosity of Atmospheric Air
空气粘度9. Power of the Wind
风功率10. Standard Wind Class Definitions (Used in the U.S.)
标准风力等级(美国用)Unit Abbreviations
单位缩写
m(米) = metre = 3.28 ft. (英尺) J(焦) = Joule(焦耳)s(秒) = second(秒) cal(卡) = calorie(卡路里)h(时) = hour(小时) toe(吨) = tonnes of oil equivalent(吨油当量)N(牛) = Newton(牛顿)Hz(赫)= Hertz (cycles per second)(赫兹 每秒周期)W(瓦) = Watt(瓦特)HP(马力) = horsepower(马力)10 -12 = p pico (皮)= 1/1000,000,000,000
10 -9 = n nano (纳)= 1/1000,000,000
514
10 -6 = µ micro (微)= 1/1000,000
10 -3 = m milli (毫)= 1/1000
10 3 = k kilo = (千)1,000 = thousands
10 6 = M (兆)mega = 1,000,000 = millions
10 9 = G giga = 1,000,000,00010 12 = T tera = 1,000,000,000,00010 15 = P peta = 1,000,000,000,000,000
Wind Speeds
风速1 m/s = 3.6 km/h = 2.237 英里/小时 = 1.944 节
1 knot (1节)= 1 nautical mile per hour (每小时 1海里)= 0.5144 m/s =
1.852 km/h = 1.125 英里/小时Wind Speed Scale
风速等级Wind Speed at 10 m
heightBeaufort
Scale (outdated)等级
Wind风名距地面 10米高处风速
m/s knots0.0-0.4 0.0-0.9 0 Calm无风0.4-1.8 0.9-3.5 1
Light轻风1.8-3.6 3.5-7.0 23.6-5.8 7-11 35.8-8.5 11-17 4 Moderate和风8.5-11 17-22 5 Fresh劲风11-14 22-28 6
Strong强风14-17 28-34 717-21 34-41 8
Gale大风21-25 41-48 925-29 48-56 10
Strong Gale暴风29-34 56-65 11>34 >65 12 Hurricane台风或飓风
Roughness Classes and Roughness Lengths 粗糙度等级和粗糙尺度
515
The roughness class is defined in the European Wind Atlas on the basis of
the roughness length in metres z 0 , i.e. the height above ground level where
the wind speed is theoretically zero. ln is the natural logarithm function.
在欧洲风能图谱(European Wind Atlas)中,表面粗糙度等级是以粗糙尺度
(单位:米)为基础定义的,即理论上风速为 0的高度。ln是自然对数函数。if (length <= 0.03)
如果(尺度 <= 0.03)
class = 1.699823015 + ln(length)/ln(150)
等级= 1.699823015 + ln(length)/ln(150)
if (length > 0.03)
如果(尺度 > 0.03
class = 3.912489289 + ln(length)/ln(3.3333333)
等级= 3.912489289 + ln(length)/ln(3.3333333)
You may use the calculator below and enter either the roughness length or
the roughness class.
您可以使用下面的计算器,输入值可以是表面粗糙尺度或者粗糙度等级。Do not use the calculator until this page and its programme have loaded
completely.
请在程序完全加载后再使用本计算器。CALCULATOR
Roughness Class Calculator
516
Roughness length in m =
Roughness class
Calculator
Roughness Classes and Roughness Length Table
粗糙度等级和粗糙尺度对照表
Rough- ness Class粗糙度等级
Roughness Length m粗糙尺度
Energy Index (per cent)能量系数(百分比)
Landscape Type地貌类型
0 0.0002 100 Water surface 水面
0.5 0.0024 73
Completely open terrain with a smooth surface, e.g.concrete runways in airports, mowed grass, etc. 完全开放的光滑地表,如混凝土机场跑道、修剪过的草坪等
1 0.03 52
Open agricultural area without fences and hedgerows and very scattered buildings. Only softly rounded hills 没有围墙、篱笆的开放性农场,且建筑物非常分散。弧度很小的小山丘
1.5 0.055 45
Agricultural land with some houses and 8 metre tall sheltering hedgerows with a distance of approx. 1250 metres 有一些房屋的农田,防护林不超过 8米高,且相隔1.25千米
2 0.1 39
Agricultural land with some houses and 8 metre tall sheltering hedgerows with a distance of approx. 500 metres 有一些房屋的农田,防护林不超过 8米高,且相隔500米
2.5 0.2 31 Agricultural land with many houses, shrubs and plants, or 8 metre tall sheltering
517
hedgerows with a distance of approx. 250 metres 有许多房屋、灌木和植物的农田,或者 8米高的防护林相距约 250米
3 0.4 24
Villages, small towns, agricultural land with many or tall sheltering hedgerows, forests and very rough and uneven terrain 有许多高大防护林、森林的乡村、小城镇、农田,以及非常粗糙不平的地带
3.5 0.8 18 Larger cities with tall buildings 有高层建筑的大城市
4 1.6 13 Very large cities with tall buildings and skycrapers 有摩天大楼及许多高层建筑的特大城市
Definitions according to the European Wind Atlas, WAsP. For practical
examples, see the Guided Tour section on Wind Speed Calculation.
根据欧洲风能图谱的定义。实例请参见“风速计算”一节。Density of Air at Standard Atmospheric Pressure
标准大气压下的空气密度Temperature
°Celsius温度摄氏度
Temperature ° Farenheit温度华氏度
Density, i.e. mass of dry air
kg/m 3
密度 干燥空气kg/m3
Max. water content kg/m 3
最大含水量kg/m 3
-25 -13 1,423-20 -4 1,395-15 5 1,368-10 14 1,342-5 23 1,3170 32 1,292 0,0055 41 1,269 0,00710 50 1,247 0,00915 59 1,225 *) 0,01320 68 1,204 0,01725 77 1,184 0,02330 86 1,165 0,03035 95 1,146 0,039
518
40 104 1,127 0,051*) The density of dry air at standard atmospheric pressure at sea level at 15° C is used as a standard in the wind industry. 在温度为 15° C,一个标准大气压下,海平面处,的干燥空气密度被用作风电行业的标准Viscosity of Atmospheric Air
空气粘度Temperatur
e ° Celsius
μ 20 1.80 E -5 1.50 E -5
50 1.95 E -5 1.79 E -5
Note: E -5 means exponential notation, i.e. the number should be multiplied by 0.00001 注:E -5是指数表示法,即乘以 0.00001
Power of the Wind **)
m/s W/m 2 m/s W/m 2 m/s W/m 2
0 0 8 313.6 16 2508.8 1 0.6 9 446.5 17 3009.2 2 4.9 10 612.5 18 3572.1 3 16.5 11 815.2 19 4201.1 4 39.2 12 1058.4 20 4900.0 5 76.2 13 1345.7 21 5672.4 6 132.3 14 1680.7 22 6521.9 7 210.1 15 2067.2 23 7452.3
**) For air density of 1.225 kg/m 3 , corresponding to dry air at standard atmospheric pressure at sea level at 15° C. 相当于海平面上,15° C时,一个标准大气压下的干燥空气的密度:1.225 kg/m 3
The formula for the power per m 2 in Watts = 0.5 * 1.225 * v 3 , where v is the wind speed in m/s. 公式:风功率(瓦/平方米)=0.5 * 1.225 * v 3 中,风速单位为m/sWarning:
Although the power of the wind at a wind speed of e.g. 7 m/s is 210 W/m 2 ,
you should note, that the average power of the wind at a site with an average
wind speed of 7 m/s typically is about twice as large. To understand this, you
should read the pages in the Guided Tour beginning with the Weibull
Dustribution and ending with the Power Density Function.
519
警告:
虽然风功率是指风在某一个速度时的功率,例如风速为 7 m/s时,风功率为
210 W/m2,但您应该注意的是,现场的平均风速为 7 m/s时,平均风功率却通
常是以上值的两倍。要理解这一点,请参阅导读中从威布尔分布到功率密度函数
这一部分的内容。Standard Wind Class Definitions (Used in the U.S.)
标准风力等级定义(美国使用)Class 30 m height
30米高50 m height
50米高Wind
speed m/s风速米/秒
Wind power W/m 2
风功率瓦/平方米
Wind speed m/s风速米/秒
Wind power W/m 2
风功率瓦/平方米
1 0-5.1 0-160 0-5.6 0-200 2 5.1-5.9 160-240 5.6-6.4 200-300 3 5.9-6.5 240-320 6.4-7.0 300-400 4 6.5-7.0 320-400 7.0-7.5 400-500 5 7.0-7.4 400-480 7.5-8.0 500-600 6 7.4-8.2 480-640 8.0-8.8 600-800 7 8.2-11.0 640-1600 8.8-11.9 800-2000
Energy and power 能量和功率
Wind Energy Reference Manual Part 2: Energy and Power Definitions
风能参考手册 第2部分:能量和功率的定义 1. Energy
520
能量2. Energy Units
能量单位3. Power
功率4. Power Units
功率单位Energy
Physicists define the word energy as the amount of work a physical system is
capable of performing. Energy, according to the definition of physicists, can
neither be created nor consumed or destroyed.
物理学家将能量一词定义为一个物理系统能够做功的量度。从定义可以看出,能
量既不能被创造也不能被销毁。Energy, however may be converted or transferred to different forms: The
kinetic energy of moving air molecules may be converted to rotational energy
by the rotor of a wind turbine, which in turn may be converted to electrical
energy by the wind turbine generator. With each conversion of energy, part of
the energy from the source is converted into heat energy.
521
但是,能量可以被转化成各种形式:空气分子移动的动能可以被转化成风力机
转轮转动的能量,并进而通过发电机组转化成电能。每一次转换,都会有部分的
能量转化成热能。When we loosely use the expression energy loss (which is impossible by the
definition above), we mean that part of the energy from the source cannot be
used directly in the next link of the energy conversion system, because it is
converted into heat. E.g. rotors, gearboxes or generators are never 100 per
cent efficient, because of heat losses due to friction in the bearings, or friction
between air molecules.
当我们不严谨地说到能量损耗(从上面的定义来看这是不可能的)时,我们实
际上指的是源头的能量有一部分因变成热能而不能被转化到下一个环节。例如转
轮、齿轮箱、发电机的效率都不是 100%,这是因为空气分子、轴承等之间总是存
在摩擦,从而产生热量损耗。Most of us have the sensible notion, however, that as we e.g. burn fossil fuels,
somehow, loosely speaking, the global potential for future energy conversion
becomes smaller. That is absolutely true.
大部分人都可以得到这样一个不是很严谨的结论,即随着化石燃料的燃烧,全
世界在未来的能量转化潜力缩小了。这是千真万确的。
522
Physicists, however, use a different terminology: They say that the amount of
entropy in the universe has increased. By that they mean that our ability to
perform useful work converting energy decreases each time we let energy
end up as heat which is dissipiated into the universe. Useful work is called
exergy by physicists.
当然,物理学家会使用一个不同的术语:他们说宇宙中的熵量增加了。意思是说
每当能量最终进入热能状态时就耗散于宇宙中,其能够做有用功的潜力就减少
了。物理学家称有用功为㶲。Since the vast majority of wind turbines produce electricity, we usually
measure their performance in terms of the amount of electrical energy they
are able to convert from the kinetic energy of the wind. We usually measure
that energy in terms of kilowatt hours (kWh) or megawatt hours MWh during a
certain period of time, e.g. an hour or a year.
因为绝大多数风力机都被用来产生电能,所以我们衡量风力机的表现通常是看
其能够将多少风的动能转换为电能。通常的表示方法是在一段时间(如一小时或
一年)内,输出了多少千瓦小时(kWh)或者兆瓦小时MWh的电能。People who want to show that they are very clever, and show that they
understand that energy cannot be created, but only converted into different
forms, call wind turbines Wind Energy Converters (WECs). The rest of us may
still call them wind turbines.
523
有的人将风力机称为风能转换器(WECs),以展示他们的小聪明或者已经认
识到能量只能进行转换而不能被创造出来,我们其余人仍然可以称其为风力机。Note注意 Energy is not measured in kilowatts, but in kilowatt hours (kWh). Mixing up the
two units is a very common mistake, so you might want to read the next
section on power to understand the difference.
能量的单位不是千瓦,而是千瓦小时(kWh)。一个常见的错误就是混淆了这两
个单位,所以您有必要阅读下一节功率,以明确其区别。Energy Units 能量单位1 J (joule) = 1 Ws = 0.2388 cal
1焦(焦耳)=1瓦秒=0.2388卡路里1 GJ (gigajoule) = 10 9 J
1 TJ (terajoule) = 10 12 J
1 PJ (petajoule) = 10 15 J
1 kWh (kilowatt hour) = 3,600,000 Joule
1 toe (tonne oil equivalent 吨油当量)
= 7.4 barrels of crude oil in primary energy 桶原油(一次能源)
= 7.8 barrels in total final consumption 最终消耗桶
= 1270 m 3 of natural gas 立方米天然气524
= 2.3 metric tonnes of coal 公吨煤
1 Mtoe (million tonne oil equivalent 百万吨油当量) = 41.868 PJ
Power 功率Electrical power is usually measured in watt (W), kilowatt (kW), megawatt
(MW), etc. Power is energy transfer per unit of time.
电功率是指单位时间内转移的能量,通常使用的单位是瓦(W)、千瓦(kW)、兆瓦
(MW)。Power may be measured at any point in time, whereas energy has to be
measured during a certain period, e.g. a second, an hour, or a year. (Read
the section on energy, if you have not done so yet).
功率可以在任何时间点测量,但能量必须在一个时间段内进行测量,例如一秒、
一小时或一年(如果您不是这样做的,请阅读关于能量的那部分内容)。If a wind turbine has a rated power or nameplate power of 1000 kW, that tells
you that the wind turbine will produce 1000 kilowatt hours (kWh) of energy per
hour of operation, when running at its maximum performance (i.e. at high
winds above, say, 15 metres per second (m/s)).
如果一台风力机的额定功率或者铭牌功率是 1000千瓦,那就是说当它以最大
功率运行时(如 15米/秒的大风情况下),每小时将产生 1000千瓦小时的电能。
525
If a country like Denmark has, say 1000 MW of wind power installed, that
does not tell you how much energy the turbines produce. Wind turbines will
usually be running, say, 75 per cent of the hours of the year, but they will only
be running at rated power during a limited number of hours of the year.
比如像丹麦这样的一个国家,假设安装了 1000兆瓦的风力机,这并不能标明
这些风机发出了多少电能。一年内,风力机常常有 75%的时间在运行,但只有
很有限的时间以额定功率运行。In order to find out how much energy the wind turbines produce you have to
know the distribution of wind speeds for each turbine. In Denmark's case, the
average wind turbines will return 2,300 hours of full load operation per year.
To get total energy production you multiply the 1000 MW of installed power
with 2,300 hours of operation = 2,300,000 MWh = 2.3 TWh of energy. (Or
2,300,000,000 kWh).
为了确定风力机发出了多少电能,您必须知道每台风力机的风速分布。在丹麦,
平均每台风力机的年满负荷发电小时数是 2300小时。要知道总的发电量,只需
要将额定功率 1000兆瓦乘以年发电利用小时数 2300小时,即得 2.3万亿瓦小
时(或者 23亿千瓦小时)。In other areas, like Wales, Scotland, or Western Ireland you are likely to have
something like 3,000 hours of full load operation or more. In Germany the
figure is closer to 2,000 hours of full load operation.
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在其它地区,例如威尔士、苏格兰或者西爱尔兰,年满负荷发电小时数能够达到
3000小时。在德国,这一数字接近 2000小时。The power of automobile engines are often rated in horsepower (HP) rather
than kilowatt (kW). The word "horsepower" may give you an intuitive idea that
power defines how much "muscle" a generator or motor has, whereas energy
tells you how much "work" a generator or motor performs during a certain
period of time.
汽车发动机的功率常用马力(HP)而非千瓦来表示。“马力”这个词也许会给
您这样一种直观概念,即功率表示了发电机或发动机有多少“肌肉”,而能量
表明了其在一段时间内可以做多少“工作”。Power Units 功率单位1 kW = 1.359 HP 1千瓦=1.359马力
Proof of Betz' law 贝兹定律的证明
Proof of Betz' Law
贝兹定律的证明(The original formulation of Betz' law in German.)(贝兹定律在德文中的最初表达形式)This page gives a proof of Betz' law. Before reading this page you
should have read the pages in the Guided Tour on how the wind
turbine deflects the wind and Betz' Law. If you do not follow the
argument in detail, just glance through the rest of this page, which
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uses Betz' own reasoning from his book Wind-Energie from 1926 to explain
the law.
本页给出了贝兹定律的证明。在阅读这部分之前,您应已经该读过风力机的偏航
及贝兹定律这两章中的内容。如果您对一些细节不是很清楚,请迅速扫过本页的
其余类容。这里采用了贝兹在他 1926年出版的《风能(Wind-Energie)》一书中
所使用过的证明方法。Proof of Betz' Theorem 贝兹定理 的证明Let us make the reasonable assumption that the average wind speed through
the rotor area is the average of the undisturbed wind
speed before the wind turbine, v 1 , and the wind
speed after the passage through the rotor plane, v 2 ,
i.e. (v 1 +v 2 )/2. (Betz offers a proof of this).
我们首先作一合理的假设:转轮处的平均风速是原始
风速与通过转轮后的风速之平均,即 V=(V1+V2)/2。(贝兹证明了这一点。)The mass of the air streaming through the rotor during one second is
1秒钟内通过转轮的气流量是m = F (v 1 +v 2 )/2
where m is the mass per second, is the density of air, F is the swept rotor
area and [(v 1 +v 2 )/2] is the average wind speed through the rotor area. The
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power extracted from the wind by the rotor is equal to the mass times the drop
in the wind speed squared (according to Newton's second law):
其中,m是每秒钟通过的气体质量, 是空气密度,F是转轮扫过的面积,[(v 1
+v 2 )/2]是通过转轮的平均风速。从风中捕获的功率等于气体质量乘以前后风速
平方差的一半(根据牛顿第二定理):P = (1/2) m (v 1
2 - v 2 2 )
Substituting m into this expression from the first equation we get the following
expression for the power extracted from the wind:
将质量m的表达式代入这个方程,就可以得到捕获风功率的计算式,如下:P = ( /4) (v 1
2 - v 2 2 ) (v 1 +v 2 ) F
Now, let us compare our result with the total power in the undisturbed wind
streaming through exactly the same area F, with no rotor blocking the wind.
We call this power P 0 :
现在,我们将这个结果与风在不受干扰情况下通过相同面积 F时的功率做一比
较。在没有转轮时,我们称其功率为 P0:P 0 = ( /2) v 1
3 F
The ratio between the power we extract from the wind and the power in the
undisturbed wind is then:
我们所捕获的风功率与风在不受干扰情况下的原始功率之比为(P/P 0 ) = (1/2) (1 - (v 2 / v 1 ) 2 ) (1 + (v 2 / v 1 ))
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We may plot P/P 0 as a function of v 2 /v 1
我们可以作出功率比 P/P0随速度比 V2/V1的变化曲线
We can see that the function reaches its maximum for v 2 /v 1 = 1/3, and that
the maximum value for the power extracted from the wind is 0,59 or 16/27 of
the total power in the wind.
我们可以看到,该函数在 v 2 /v 1 = 1/3取得极大值,从风中所能捕获的功率为
总功率的 0.59或者 16/27。Click here to go back the Guided Tour page on Betz' Law.
点击以下链接可以返回“贝兹定律”一节。
Wind turbine acoustics 风力机声学
Wind Energy Reference Manual Part 3: Acoustics
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风能参考手册 第3部分:声学1. dB(A) Sound Levels in decibels and Sound Power in W/m 2
声级(分贝 dB)和声功率(W/m2)2. Sound Level by Distance from Source
声源距离对声级的影响3. Adding Sound Levels from Two Sources
两个声源的声级相加4. How to add sound levels in general
声级相加的一般方法dB(A) Sound Levels in decibels and Sound Power in W/m2
声级(分贝 dB)和声功率(W/m2)对照表Level dB(A) Power W/m 2 Level
dB(A) Power W/m 2 Level dB(A) Power W/m 2
0 -12 1,000*10 55 -7 3,162*10 83 -4 1,995*10 10 -11 1,000*10 56 -7 3,981*10 84 -4 2,512*10 20 -10 1,000*10 57 -7 5,012*10 85 -4 3,162*10 30 -9 1,000*10 58 -7 6,310*10 86 -4 3,981*10 31 -9 1,259*10 59 -7 7,943*10 87 -4 5,012*10 32 -9 1,585*10 60 -6 1,000*10 88 -4 6,310*10 33 -9 1,995*10 61 -6 1,259*10 89 -4 7,943*10 34 -9 2,512*10 62 -6 1,585*10 90 -3 1,000*10 35 -9 3,162*10 63 -6 1,995*10 91 -3 1,259*10 36 -9 3,981*10 64 -6 2,512*10 92 -3 1,585*10 37 -9 5,012*10 65 -6 3,162*10 93 -3 1,995*10 38 -9 6,310*10 66 -6 3,981*10 94 -3 2,512*10 39 -9 7,943*10 67 -6 5,012*10 95 -3 3,162*10 40 -8 1,000*10 68 -6 6,310*10 96 -3 3,981*10 41 -8 1,259*10 69 -6 7,943*10 97 -3 5,012*10
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42 -8 1,585*10 70 -5 1,000*10 98 -3 6,310*10 43 -8 1,995*10 71 -5 1,259*10 99 -3 7,943*10 44 -8 2,512*10 72 -5 1,585*10 100 -2 1,000*10 45 -8 3.162*10 73 -5 1.995*10 101 -2 1,259*10 46 -8 3,981*10 74 -5 2.512*10 102 -2 1,585*10 47 -8 5,012*10 75 -5 3,162*10 103 -2 1,995*10 48 -8 6,310*10 76 -5 3,981*10 104 -2 2,512*10 49 -8 7.943*10 77 -5 5.012*10 105 -2 3,162*10 50 -7 1,000*10 78 -5 6,310*10 106 -2 3,981*10 51 -7 1,259*10 79 -5 7,943*10 107 -2 5,012*10 52 -7 1,585*10 80 -4 1.000*10 108 -2 6,310*10 53 -7 1,995*10 81 -4 1,259*10 109 -2 7,943*10 54 -7 2,512*10 82 -4 1,585*10 110 -1 1,000*10
Sound Level by Distance from Source
Distance m Sound Level Change dB(A) Distance m Sound Level
Change dB(A) Distance m Sound Level Change dB(A)
9 -30 100 -52 317 -62 16 -35 112 -53 355 -63 28 -40 126 -54 398 -64 40 -43 141 -55 447 -65 50 -45 159 -56 502 -66 56 -46 178 -57 563 -67 63 -47 200 -58 632 -68 71 -49 224 -59 709 -69 80 -50 251 -60 795 -70 89 -51 282 -61 892 -71
How to use the table above:
如何使用上面的表:If a wind turbine has a source noise level of 100 dB(A), it will have a noise
level of 45 dB(A) 141 m away. [100 - 55 dB(A) = 45 dB(A)].
如果一台风力机发出的噪声为 100分贝,当与其相隔 141米时,声级将变为 45
分贝。[100 - 55 dB(A) = 45 dB(A)]
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The sound level decreases by approximately 6 dB(A) [ = 10*log 10 (2) ] every
time you double the distance to the source of the sound. The table assumes
that sound reflection and absorption (if any) cancel one another out.
到声源的距离每增加一倍,声级就减少约 6分贝。该表假定不存在声波的反射和
吸收。How to derive the table above:
如何推导出上面的表:The surface of a sphere = 4 pi r 2, where pi = 3.14159265, and r is the radius
of the sphere. If we have a sound emission with a power of x W/m 2 hitting a
sphere with a certain radius, then we'll have the same power hitting four times
as large an area, if we double the radius.
球的表面积=4 pi r 2,其中 pi = 3.14159265,r 代表球的半径。从球心发出的声
波激发了某个球面,此时半径为 r,功率为 x W/m 2,如果把半径扩大一倍,那
么相同能量所激发的面积就是 4倍。Adding Sound Levels from Two Sources
两个声源的声级相加dB 41 42 43 44 45 46 47 48 49 50 41 44.0 44.5 45.1 45.8 46.5 47.2 48.0 48.8 49.6 50.5 42 44.5 45.0 45.5 46.1 46.8 47.5 48.2 49.0 49.8 50.6 43 45.1 45.5 46.0 46.5 47.1 47.8 48.5 49.2 50.0 50.8 44 45.8 46.1 46.5 47.0 47.5 48.1 48.8 49.5 50.2 51.0 45 46.5 46.8 47.1 47.5 48.0 48.5 49.1 49.8 50.5 51.2 46 47.2 47.5 47.8 48.1 48.5 49.0 49.5 50.1 50.8 51.5 47 48.0 48.2 48.5 48.8 49.1 49.5 50.0 50.5 51.1 51.8
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48 48.8 49.0 49.2 49.5 49.8 50.1 50.5 51.0 51.5 52.1 49 49.6 49.8 50.0 50.2 50.5 50.8 51.1 51.5 52.0 52.5 50 50.5 50.6 50.8 51.0 51.2 51.5 51.8 52.1 52.5 53.0
Example: A turbine located at 200 m distance with a source level of 100 dB(A)
will give a listener a sound level of 42 dB(A), as we learned in the table before
this one. Another turbine 160 m away with the same source level will give a
sound level of 44 dB(A) on the same spot. The total sound level experienced
from the two turbines will be 46.1 dB(A), according to the table above.
例子:一台风机位于 200米远处,其噪声等级为 100分贝,那么观测者将能测
到 42分贝,我们在前面已经讨论过这一点。同时,另一台风机位于 160米远处,
噪声等级相同,观测者可以测到 44分贝。那么通过查表可知,观测处来自两台
风机总的噪声等级将是 46.1分贝。Two identical sound levels added up will give a sound level +3 dB(A)
higher. Four turbines will give a sound level 6 dB(A) higher. 10 turbines will
give a level 10 dB(A) higher.
两个相同的等级的噪声相加,总噪声增加 3分贝或更高。有 4台噪声等级相同
的风机时,总噪声增加 6分贝或更高。10台时,声级增加 10分贝或更高。How to add sound levels in general 声级相加的一般方法For each one of the sound levels at the spot where the listener is located, you
look up the sound power in W/m 2 in the first of the three sound tables. Then
you add the power of the sounds, to get the total no. of W/m 2 . Then use the
formula dB = 10 * log 10 (power in W/m 2 ) + 120, to get the dB(A) sound level.
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首先根据表 1查出每个噪声源到观测者处的噪声功率,单位为W/m 2,然后将
它们相加,得到总的声功率,接下来使用下面的公式计算声级:声级(dB) =
10 * log 10(声功率(W/m 2)) + 120。
Electricity 电
Wind Energy Reference Manual Part 4: Electricity
风能参考手册 第4部分:电Voltage 电压In order to make a current flow through a cable you need to have a voltage
difference between the two ends of the cable - just like if you want to make air
move through a pipe, you need to have different pressure at the two ends of
the pipe.
为了使一段电缆中流过电流,必须使电缆两端之间存在电位差。就如同要想使空
气流过一段管道,必须使管道两端存在气压差。If you have a large voltage difference, you may move larger amounts of
energy through the wire every second, i.e. you may move larger amounts of
power. (Remember that power = energy per unit of time, cf. the page on
Energy and Power Definitions).
电位差越大,每秒钟流过导线的电流也会越大,同时功率也会更大。(请记住功
率表示单位时间内传递的能量,您可以对比能量和功率的定义两节。)
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Alternating Current 交流电The electricity that comes out of a battery is direct current (DC), i.e. the
electrons flow in one direction only. Most electrical grids in the world are
alternating current (AC) grids, however.
从电池中流出的是直流电(DC),也就是说电流始终朝一个方向流动。但是世
界上大多数的电网都是交流(AC)电网。One reason for using alternating current is that it is fairly cheap to transform
the current up and down to different voltages, and when you want to transport
the current over longer distances you have much lower energy losses when
you use a high voltage. Another reason is that it is difficult and expensive to
build circuit breakers (switches) for high DC voltages which do not produce
huge sparks.
人们使用交流电的一个原因是交流电的升压与降压更便宜、方便。当需要远距离
输电时,提高电压等级可以减小线路损耗。另一个原因是制造不产生电弧的直流
断路器(开关)很困难而且昂贵。Grid Frequency 电网频率
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With an alternating current in the electrical grid, the current changes direction
very rapidly, as illustrated on the graph above: Ordinary household current in
most of the world is 230 Volts alternating current with 50 cycles per second =
50 Hz ("Hertz" named after the German Physicist H.R. Hertz (1857-1894)).
The number of cycles per second is also called the frequency of the grid. In
America household current is 130 volts with 60 cycles per second (60 Hz).
在交流电网中,电流的方向变化得非常快。如上图所示:在世界上大部分地区,
普通家庭用电的电压是 230V,每秒钟变化的周期为 50 次,即 50Hz(“Hz赫
兹”是以德国物理学家海因里希·鲁道夫·赫兹(1857-1894)命名的)。每秒钟
变化的周期又称为电网的频率。美国家庭用电的电压为 130V,频率为 60Hz。In a 50 Hz system a full cycle lasts 20 milliseconds (ms), i.e. 0.020 seconds.
During that time the voltage actually takes a full cycle between +325 Volts and
-325 Volts. The reason why we call this a 230 volt system is that the electrical
energy per second (the power) on average is equivalent to what you would
get out of a 230 volt DC system. As you can see in the graph, the voltage has
a nice, smooth variation. This type of wave shape is called a sinusoidal curve,
because you can derive it from the mathematical formula voltage = vmax *
sin(360 * t * f), where vmax is the maximum voltage (amplitude), t is the time
measured in seconds, and f is the frequency in Hertz, in our case f = 50. 360
is the number of degrees around a circle. (If you prefer measuring angles in
radians, then replace 360 by 2*pi).
在 50赫兹系统中,一个周期是 20毫秒,即 0.020秒。在此期间内,电压实际上
是从+325伏变为-325伏。我们称之为 230伏系统的原因是,其每秒传递的电能
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(功率)相当于使用 230伏的直流电。正如您在图中所看到的,电压变化得很
平滑。这种波形被称为正弦曲线,因为我们可以从以下数学公式得到:
V=Vmax*sin(360 * t * f),其中 Vmax指电压最大值(幅值),t指时间(单
位为秒),f指频率(单位为赫兹)。在我们的例子中,f=50. 360。(如果你更
喜欢使用弧度,那么可以讲 360 替换为 2*pi。)Phase 相位Since the voltage in an alternating current system keeps oscillating up and
down you cannot connect a generator safely to the grid, unless the current
from the generator oscillates with exactly the same frequency, and is exactly
"in step" with the grid, i.e. that the timing of the voltage cycles from the
generator coincides exactly with those of the grid. Being "in step" with the grid
is normally called being in phase with the grid.
由于交流电系统中,电压在不断地向上或向下震荡,所以一台发电机要实现并
网必须具有与电网严格相同的频率,而且 “同步”。也就是说发电机输出的电
压周期与电网电压周期正好一样。与电网“同步”是指与电网电压相位相同。If the currents are not in phase, there will be a huge power surge which will
result in huge sparks, and ultimately damage to the circuit breaker (the
switch), and/or the generator.
如果电流不是同相位的,将会形成巨大的浪涌电流,并产生火花,最终损坏断
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路器(开关)或者发电机。In other words, connecting two live AC lines is a bit like jumping onto a
moving seesaw. If you do not have exactly the same speed and direction as
the seesaw, both you and the people on the seesaw are likely to get hurt.
换句话说,将两条交流线路连接起来就像跳上一个正在动的跷跷板。如果你和跷
跷板的速度或者方向不一样,那么两者就都有可能受到伤害。The page on Power Quality Issues explains how wind turbines manage to
connect safely to the grid.
“电能质量问题”一节介绍了如何使风力机安全地并网。Alternating Current and Electromagnetism 交流电与电磁感应现象To learn about electromagnetism, turn to the next pages.
要了解电磁感应现象,请翻到下一页。
3 phased electricity 3 相交流电
3 Phase Alternating Current
3相交流电The power of alternating current (AC) fluctuates. For domestic use for e.g.
light bulbs this is not a major problem, since the wire in the light bulb will stay
warm for the brief interval while the power drops. Neon lights (and your
computer screen) will blink, in fact, but faster than the human eye is able to
perceive. For the operation of motors etc. it is useful, however, to have a
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current with constant power.
交流电的功率始终在波动。对于像电灯等应用,这不存在很大的问题,因为即使
在功率下降时,灯丝也能暂时保持高温状态。霓虹灯(以及你的电脑屏幕)会闪
烁,但实际上比人眼所能感知到的要快。然而,电机等更需要一个功率恒定的电
源。Voltage Variation for Three Phase Alternating Current 三相交流电的电压变化
It is indeed possible to obtain constant
power from an AC system by having three
separate power lines with alternating
current which run in parallel, and where
the current phase is shifted one third of the
cycle, i.e. the red curve above is running one third of a cycle behind the blue
curve, and the yellow curve is running two thirds of a cycle behind the blue
curve.
通过交流系统获得恒定的功率确实是可行的。只要将三条交流线路并行起来,它
们之间的相位差为 1/3 周期,即上图中红色曲线滞后蓝色曲线 1/3 周期,黄色曲
线又滞后红色曲线 1/3 周期。As we learned on the previous page, a full cycle lasts 20 milliseconds (ms) in
a 50 Hz grid. Each of the three phases then lag behind the previous one by
20/3 = 6 2/3 ms.
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我们在上一页已经了解到,50Hz系统中一个周期持续 20毫秒(ms)。因此每
相滞后前一相 20/3=6 2/3 ms.
Wherever you look along the horizontal axis in the graph above, you will find
that the sum of the three voltages is always zero, and that the difference in
voltage between any two phases fluctuates as an alternating current.
沿着横坐标,不论你什么时候网上看都可以发现 3相电压之和总是为 0,而且
任意两相之间的电压差也是波动的。On the next page you will see how we connect a generator to a three phase
grid.
在下一页,您将看到怎样将一个发电机与三相电网相连。
3 phased connection 3 相连接形式
Connecting to 3 Phase Alternating Current
与 3相交流电网相连
On the page on synchronous generators we mention that each of the
electromagnets in the stator is connected to its own phase. You may wonder
how that can be done, because in a three phase system we usually have only
three conductors (wires). The answer is given in the pictures above:
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在同步发电机这一节,我们提到每个定子线圈都与其所对应的那一相相连。你也
许会想这怎么可能,毕竟在 3相系统中,我们通常只有 3 根导体(线)。答案就
在上面的图片中。Delta Connection 三角形连接If we call the three phase conductors L1, L2 and L3, then you connect the first
magnet to L1 and L2, the second one to L2 and L3, and the third one to L3
and L1.
如果我们用 L1、L2、L3 代表三相导线,那么把第一导体连到 L1和 L2,第二个
连到 L2和 L3,第三个连到 L3和 L1。This type of connection is called a delta connection, because you may
arrange the conductors in a delta shape (a triangle). There will be a voltage
difference between each pair of phases which in itself is an alternating
current. The voltage difference between each pair of phases will be larger
than the voltage we defined on the previous page, in fact it will always be
1.732 times that voltage (1.732 is the square root of 3).
这种连接形式称为三角形连接,因为你可以把导体摆成三角形。每两相之间都会
有电压差(线电压),而且本身就是交流电。这个线电压会比我们上一页所定义
的相电压大,实际上线电压总是相电压的 1.732倍。(1.732是 3的平方根。)Star Connection 星形连接
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There is another way you may connect to a three phase grid, however:
当然,还有一种方法可以连到三相电网。You may also connect one end of each of the three magnet coils to its own
phase, and then connect the other end to a common junction for all three
phases. This may look surprising, but consider that the sum of the three
phases is always zero, and you'll realise that this is indeed possible.
你也可以将三个电磁线圈的一端连到其对应相上,并把另一端都连到一个公共
节点上。这看起来有些奇怪,但是只要想一想三相电压之和总是为 0,你就会意
识到这种连接方式确实是可行的。
Electromagnetism 1 电磁效应 1 Electromagnetism
电磁效应Electromagnetism was discovered by
accident in 1821 by the Danish Physicist
H.C. Ørsted. Electromagnetism is used both
in the conversion of mechanical energy to
electrical energy (in generators) and in the
opposite direction in electric motors.
1821年,丹麦物理学家汉斯·克里斯蒂安·奥
斯特很偶然地发现了电磁感应现象。电磁感应
543
原理既被用于将机械能转换为电能(发电机),又被用在相反的方向上(电动
机)。In the picture to the left we have set up an electric circuit with a coil of
insulated copper wire, winding around an "iron" (magnetic steel) core.
左图中我们搭建了一个电路,其中有一个用绝缘铜导线缠绕在铁芯上而制成的
螺线管电磁铁。Click the switch in the picture to the left to turn on the (direct) current, and
watch what happens.
点击图中的开关,接通直流电,观察有什么发生了。
Electromagnetism 2 电磁效应 2 Electromagnetism
电磁效应 The current magnetises the iron core and
creates a pair of magnetic poles, one North,
and the other South. The two compass
needles consequently point in opposite
directions. (You may repeat the experiment by
clicking on the switch again).
电流使铁芯磁化并产生两个磁极,一北一南。
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因此两个指南针会指向相反的方向。(你也可以通过再次点击开关重复这个实
验。)This magnetic field would be created whether we had the iron core in the
middle or not. But the iron core makes the magnetic field much more
powerful.
不论有没有铁芯,都能产生这个磁场。不过磁芯能够使磁场更强。The iron core may be shaped e.g. like a horse shoe, or a C , which is a design
used in generators.
铁芯也可以做成如马蹄形或者C形,发电机中就是这样设计的。Generators usually have several North - South pole pairs.
发电机中通常有几对南-北极。For now, let's see how electromagnetism can work "in reverse" on the next
page on induction.
在下一节,我们将看到电磁感应如何以相反的方式工作。
Induction 1 感应 1 Induction
感应To the left we have set up another experiment, that looks almost like the one on the previous page. In the upper part we have a battery, a switch, and an electromagnet.
545
左图中我们建立了一个实验,它看起来和前一个几乎一样。在上面这部分电路中有一块电池、一个开关和一个电磁铁。Below the electromagnet we have set up another iron core with an insulated
copper coil around it. We have then connected a light bulb to the lower coil.
在下面这部分,我们用绝缘铜导线缠绕另一个铁芯又做了一个电磁铁,并接上
了一个灯泡。Now, once again, flick the switch, and watch what happens.
现在,再次按动开关,看会有什么发生。
Induction 2 感应 2 Induction
感应As you can see, the light bulb flashes the moment you connect the switch to
the battery.
正如你所看到的,在你连通电池的一瞬间,电灯
闪烁了一下。The explanation is, that the magnetic field
coming from the upper electromagnet flows
through the lower iron core.
对这一现象的解释是,上面这个电磁铁所产生的磁场通过了下面这个铁芯。
546
The change in that magnetic field, in turn induces an electric current in the
lower coil.
磁场的变化反过来在下面的线圈中产生了一个电流。You should note that the current in the lower coil ceases once the magnetic
field has stabilised.
你应该注意到的是一旦磁场稳定了,下面的线圈中就没有电流了。If you switch off the current, you get another flash, because the magnetic
field disappears. The change in the field induces another current in the lower
core, and makes the light bulb flash again.
如果你切断电流,电灯将会再闪一次,因为磁场消失了,磁场的变化又会在
下面的线圈中激发一个电流,从而使灯泡闪烁。In order to apply your knowledge of electromagnetism and induction, you
may now return to the page on wind turbine generators.
为了应用您所学到的电磁感应方面的知识,请回到风力发电机这一页。
Environment and fuels 环境与燃料
Wind Energy Reference Manual Part 5: Environment and Fuels
风能参考手册 第5部分:环境和燃料1. Energy Content of Fuels
燃料所含的能量
547
2. CO 2 -Emissions from Fuels
燃烧化石燃料所排放的二氧化碳Energy Content of Fuels *)
GJ per tonneNorth Sea Crude Oil 北海原油 42.7
LPG (Liquefied petroleum gas: Propane, Butane) 液化石油气(液化石油气:丙烷、丁烷)
46.0
Petrol (Gasoline) 汽油(汽油) 43.8
JP1 (Jet aircraft fuel) JP1(喷气式飞机燃料) 43.5
Diesel / Light Fuel oil 柴油/轻油 42.7
Heavy Fuel Oil 重油 40.4
Orimulsion 奥里油 28.0
Natural Gas 天然气 39.3 per 1000 Nm 3
Steam Coal 动力煤 24.5
Other Coal 其它煤 26.5
Straw 稻草 14.5
Wood chips 木屑 14.7
Household Waste 1995 家居废弃物(1995年) 10.0
Household Waste 1996 家居废弃物(1996年) 9.4
CO 2 -Emissions from Fuels *)
kg CO 2 per GJ kg CO 2 per kg fuelPetrol (Gasoline) 汽油(汽油) 73.0 3.20
Diesel / Light Fuel oil 74.0 3.16
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柴油/轻油 Heavy Fuel Oil 重油 78.0 3.15
Orimulsion 奥里油 76.0 2.13
Natural Gas (methane) 天然气(甲烷)
56.9 2.74
Coal 煤 95.0 2.33 (steam coal) 2.52 (other)
*) Conversion factors provided by the Danish Energy Agency 转换数据由丹麦能源局提供
Bibliography 参考文献
Wind Energy Bibliography
风能参考文献This is a list of useful publications for readers who wish to find the relevant
physics or mathematical formulae etc.
读者若希望了解更多相关的数学物理公式请参阅下列书目。Wind Energy Resources & Computing Wind Turbine Energy Output 风能资源及风力机发电量的计算
Ib Troen & Erik Lundtang Petersen: European Wind Atlas,
Risoe National Laboratory, Risoe , Denmark, 1991, ISBN 87-
550-1482-8 (Contains useful guidance on wind speed
calculation, wind statistics, wind turbine energy output, and
the theoretical foundations).
Dipl.-Ing. Dr. Albert Betz, Wind-Energie und ihre Ausnutzung durch
Windmühlen, Bandenhoeck & Ruprect, Göttingen 1926. Facsimile edition by
Ökobuch Verlag, Staufen, 1994. ISBN 3-922964-11-7
D.L.Elliott, C.G.Holladay, W.R.Barchet, H.P.Foote, W.F.Sandusky: Wind
549
Energy Resource Atlas of the United States, Solar Energy Research Institute,
Golden, Co, 1987.
How does a Wind Turbine Work?
Martin O.L. Hansen: Aerodynamics of Wind Turbines, Rotors, Loads and
Structure, James & James Ltd., London 2000, ISBN 1-
902916-06-9
Frank M. White, Fluid Dynamics, McGraw-Hill, New York
1999, ISBN 0-07-116848-6
Bruce R. Munson, Donald F. Young, Theodore H. Okiishi:
Fundamentals of Fluid Mechanics, John Wiley & Sons Inc., New York 1994,
ISBN 0-471-30585-5
Ira H. Abott & Albert E. von Doenhoff: Theory of Wing Sections, Dover
Publications, Inc., New York 1959.
Joseph Katz & Allen Plotkin: Low-Speed Aerodynamics, Second Edition,
Cambridge University Press, New York 2001, ISBN 0 521 66552 3.
John J. Bertin, Aerodynamics for Engineers, Fourth Edition, Prentice Hall,
Upper saddle River NJ 2002, ISBN 0-13-064633-4.
Franck Bertagnolio, Niels Sørensen, Jeppe Johansen and Peter Fuglsang:
Wind Turbine Airfoil Catalogue, Risø National Laboratory, Roskilde, 2001.
ISBN 87-550-2910-8
Austin Hughes: Electric Motors and Drives, Oxford 1997, Butterworth-
Heinemann, ISBN 0-7506-1741-1
Poul Erik Petersen: Elektricitet og Magnetisme, Bogfondens Forlag A/S,
København 1995, ISBN 87-7463-228-0
Poul Erik Petersen: Elektriske Maskiner, Bogfondens Forlag A/S, København
1996, ISBN 87-7463-255-8
550
Robert Gasch (Hrsg.): Windkraftanlagen, B.G.Teubner, Stuttgart 1993, ISBN
3-519-26334-3
Siegfried Heier: Windkraftanlagen im Netzbetrieb, B.G.Teubner, Stuttgart
1996, ISBN 3-519-16171-0
Designing Wind Turbines 风力机的设计
Wind Energy Department of Risoe National Laboratory and
Det Norske Veritas: Guidelines for Design of Wind Turbines,
Copenhagen 2001. ISBN 87-550-2870-5
The Danish Approval Scheme for Wind Turbines
(Godkendelsesordningen for opstilling af vindmøller i
Danmark). Web site: www.vindmoellegodkendelse.dk
Wind Energy and the Environment 风能与环境Birk Nielsens Tegnestue, Wind Turbines in the Landscape, Architecture &
Aesthetics, Aarhus 1996, ISBN 87-985801-1-6
Henrik Meyer m. fl.: Omkostningsopgørelse for miljøeksternaliteter i
forbindelse med energiproduktion, Risø-R-770 (DA), Roskilde 1994, ISBN 87-
550-2011-9
Søren Krohn: The Energy Balance of Modern Wind Turbines , Danish Wind
Industry Association, WindPower Note No. 16, København 1997.
Lars Teglgaard and others: Municipal planning for wind energy in Denmark -
Examples and experience, Ministry of Environment and Energy, Copenhagen
1994, ISBN 87-601-5027-0
Guillemette, M., Larsen, J.K. & Clausager, I.: Assessing the impact of the
Tunø Knob wind park on sea ducks: the influence of food resources, National
Environmental Research Institute, NERI Technical Report No 263,
København 1999, ISBN 87-7772-444-5
551
Wind Energy Economics 风能经济学Søren Krohn: Er 10 og 27 lige ? Offentlige Finanser og Vindkraft ,
Vindmølleindustrien, Vindkraft Note nr. 7, København 1996.
Jesper Munksgaard, m.fl.: Samfundsmæssig Værdi af Vindkraft (4
delrapporter), AKF Forlaget, København 1995, ISBN 87-7509-443-6
Hans-Henrik Kristoffersen, m.fl.: Kortlægning af Afgifter og Tilskud inden for
Energiområdet, AKF Forlaget, København 1997, ISBN 87-7509-509-2
Danish Ministry of Environment and Energy: Energy 21 - The Danish
Government's Action Plan for Energy 1996, Copenhagen 1996, ISBN 87-
7844-062-9
Danmarks Energifremtider, Energistyrelsen, København 1995, ISBN 87-7844-
027-0
Action Plan for Offshore Wind Farms in Danish Waters, The Offshore Wind-
Farm Working Group of the Electricity Companies and the Danish Energy
Agency, SEAS, Haslev 1997
Birger T. Madsen: World Market Update, BTM Consult ApS , Ringkøbing
International Energy Agency (IEA) Wind Energy Annual Report 1998, National
Renewable Energy Laboratory, Colorado, USA, April 1999
International Energy Agency (IEA) Wind Energy Annual Report 1998, National
Renewable Energy Laboratory, Colorado, USA, April 1999
Modern Wind Turbine History 现代风力机的历史Peter Karnøe, Dansk Vindmølleindustri, Samfundslitteratur, Frederiksberg
1991, ISBN 87-593-0255-0
Per Dannemand Andersen, En analyse af den teknologiske innovation i dansk
vindmølleindustri, Handelshøjskolen i København, 1993, ISBN 87-593-8027-6
552
H. C. Hansen, Poul la Cour - grundtvigianer, opfinder og folkeoplyser, Askov
Højskoles Forlag, Askov 1985, ISBN 87-88765-01-6
Reference 参考International Electrotechnical Commission: International Electrotechnical
Vocabulary - Part 415: Wind turbine systems, Geneva 1998, IEC 60050-415
George Elliot (ed.): 8. Glossary Of Terms, 2. Edition, Expert Group Study on
Recommended Practices for Wind Turbine Testing and Evaluation,
International Energy Agency Programme for Research and Development on
Wind Energy Conversion Systems, Glasgow 1993
Web Design 网页设计David Siegel: Creating Killer Web Sites , Second Edition, Hayden Books,
Indianapolis 1998, ISBN 1-56830-433-1
Jakob Nielsen: Designing Web Usability : The Practice of Simplicity, First
Edition, New Riders Publishing 1999, ISBN 156205810X
Edward R. Tufte: The Visual Display of Quantitative Information, Graphics
Press, Cheshire, Connecticut, 1983
Jan Tschichold, The Form of the Book, Essays on the Morality of Good
Design, Hartley & Marks, Vancouver, B.C. 1991, ISBN 0-88179-116-4
Paul Arthur & Romedi Passini: Wayfinding, People, Signs and Architecture,
McGraw-Hill, New York 1992, ISBN 0-07-551016-2
Glossary 词汇表
Wind Energy Glossary
风能词汇A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
553
English German Spanish French Danish 中文
Aerodynamics Aerodynamik
aerodinámica*
aérodynamique*
aerodynamik 空气动力学active stall power control
aktive Stall-regelung
regulación* activa por pérdida aerodinámica
régulation active par décrochage aérodynamique
aktiv stallregulering
主动失速功率控制
alternating current (AC)
Wechselstrom
corriente* alterna (CA)
courant alternatif
vekselstrøm 交流电anemometer Anemomete
ranemómetro anémomètre anemometer 风速表
asynchronous generator
Asynchrongenerator
generador asíncrono
générateurasynchrone
asynkrongenerator
异步发电机availability factor
Verfügbarkeitsfaktor
factor de disponibilidad
facteur de disponibilité
rådighedsfaktor
可利用因子
azimuth angle Azimuth ángulo azimutal
(angle d') azimut
azitmutvinkel 方位角Betz' law Betz'sches
Gesetzley* de Betz loi* de Betz Betz' lov 贝兹定律
birds Vögel aves* oiseaux (avifaune)
fugle 鸟类bolt assembly Verschraub
enunión* con pernos
assemblage par boulons
boltsamling 螺栓Cage rotor Käfigläufer,
Kurzschlußläufer
rotor de jaula de ardilla
induit à cage d'écureuil
kortslutningsrotor
笼形转轮
capacity credit Leistungsvergütung
crédito de capacidad
crédit de capacité
effektbetaling
信贷能力capacity factor Kapazitätsf
aktorfactor de carga
facteur de capacité
kapacitetsfaktor
容量因子computational fluid dynamics (CFD)
Computational Fluid Dynamics (CFD)
dinámica* de fluidos computacional (CFD)
dynamique* des fluides numérique
computational fluid dynamics (CFD)
计算流体力学(CFD)
cooling system
Kühlung sistema de refrigeración
système de refroidissement
kølesystem 冷却系统
Coriolis force Corioliskraft fuerza* de Coriolis
force* de Coriolis
Corioliskraft 科里奥利力
554
corrosion (offshore)
Korrosion (Offshore)
corrosión* (en agua de mar)
corrosion* (en mer)
korrosion (offshore)
腐蚀(海上)
cost of electricity
Stromkosten
coste de la electricidad
coût d'électricité
omkostninger til elproduktion
电力成本
cut in wind speed
Einschaltwind-geschwindigkeit
velocidad* de conexión
vitesse* de démarrage
starthastighed
切入风速
cut out wind speed
Abschaltwind-geschwindigkeit
velocidad* de corte
vitesse* de coupure
stophastighed
切出风速
Danish concept
Dänisches Konzept
concepto danés
conception* danoise
dansk koncept
丹麦概念dB (A), decibel (A) scale
dB(A)-Skala dB(A), escala* de decibelios A
dB (A), échelle* des décibel (A)
dB (A), decibel (A) skala
分贝(A)规模
delta connection
Dreieckschaltung
conexión* triángulo
connexion*(ou couplage) en triangle
deltaforbindelse
三角形连接
density of air Luftdichte densidad* de aire
densité* d'air massefylde, vægtfylde
空气密度direct grid connection
direkte Netzanbindung
conexión* directa a red
raccordement direct au réseau
direkte nettilslutning
直接电网连接
downwind (machine)
Leeläufer máquina* con rotor a sotavento
(éolienne*) sous le vent
bagløber 下风向(风机)
drag Luftwiderstand
resistencia* aerodinámica
traînée* drag, luftmodstand
拖动
Economics Wirtschaftlichkeit
economía* économie* økonomi 经济学economies of scale
Kostenvorteile bei größeren Anlagen
economías* de escala
économies* d'échelle
stordriftsfordele
规模经济
efficiency Wirkungsgrad
eficiencia* efficacité* effektivitet 效率electromagneti Elektromag electromagn électromagn elektromagn 电磁效应
555
sm netismus etismo étisme etisme
energy Energie energía* énergie* energi 能量energy balance
Energiebilanz
balance de energía
bilan énergétique
energibalance
能量平衡extreme load Extremlast carga*
extremacharge extrême
ekstremlast 极限载荷Fatigue load Materialerm
üdungcarga* de fatiga
charge de fatigue
udmattelseslast
疲劳载荷flange Flansche brida* bride* flange 法兰flicker kurzzeitige
Spannungs-schwankungen
flicker flicker flicker 闪烁
foundation Fundament cimentación* fondation fundament 基础Gearbox Getriebe multiplicador,
caja* multiplicadora)
multiplicateur gearkasse 齿轮箱
Gedser wind turbine
Gedser-Windkraftanlage
el aerogenerador de Gedser
l'éolienne* de Gedser
Gedsermøllen
盖瑟风力机
generator Generator generador générateur (ou génératrice*)
generator 发电机
geostrophic wind
geostrophischer Wind
viento geostrófico
vent géostrophique
geostrofisk vind
地转风
global winds globale Winde
vientos globales
vents globaux
globale vinde全球风gravity foundation (offshore)
Schwerkraft-Fundament (Offshore)
cimentación* (marina) por gravedad
fondation* de caissons (d'acier ou de béton)(offshore)
gravitationsfundament (offshore)
重力基础(海上)
grid frequency Netzfrequenz
frecuencia* de red
fréquence* du réseau
netfrekvens 电网频率(electrical) grid (elektrische
s) Netzred* (eléctrica)
réseau (électrique)
(el) net 电网gust Bö ráfaga* rafale* vindstød,
vindbyge阵风
guy (wire) Abspannun viento hauban bardun 拉索(线)
556
g
Horizontal axis wind turbine (HAWT)
Horizontalachser, -läufer
aerogenerador de eje horizontal
éolienne* à axe horizontal
horisontalakslet vindmølle
水平轴风力机(HAWT)
hub Nabe buje moyeu nav 轮毂hub height Nabenhöhe altura* de
bujehauteur du moyeu
navhøjde 轮毂高度hydraulics system
Hydrauliksystem
sistema hidraúlico
système hydraulique
hydrauliksystem
液压系统Hz (Hertz) Hz (Hertz) Hz (hercio) Hz (Hertz) Hz (Hertz) 赫兹Indirect grid connection
indirekte Netzanbindung
conexión indirecta a red*
raccordement indirect au réseau
indirekte nettilslutning
间接电网连接
induction Induktion inducción* induction* induktion 感应induction generator
Induktionsgenerator
generador de inducción
générateur à induction
asynkrongenerator
异步发电机installation costs
Installationskosten
costes de instalación
coûts d'installation
installationsomkostninger
安装成本inverter Wechselrich
terinversor onduleur vekselretter 逆变器
islanding Inselbildung islanding (o funcionamiento en isla)
opération* insulaire
ødrift 孤岛
J
Killed steel beruhichter Stall
acero calmado
acier calmé beroliget stål 脱氧钢Lattice tower Gitterturm torre* de
celosíamât en trellis gittertårn 桁架塔架
(design) lifetime
Lebensdauer
vida* (de diseño)
durée de vie* (design) levetid
(设计)寿命lift Auftrieb sustentación
* ("lift")poussée* aérodynamique
opdrift, lift 升力
Manufacturers Hersteller fabricantes fabricants fabrikanter 制造商masking noise Hintergrund
geräuscheruido enmascarador
effet de masque
maskerende lyd
掩蔽噪声
mono pile foundation (offshore)
Fundament mit einem Pfeiler (Offshore)
cimentación* (marina) monopilote
monopilot d'acier (fondation offshore)
enkeltspælsfundament (offshore)
单桩基(海上)
557
mountain wind Bergwind viento de montaña
vent de montagne
bjergvind 山风Nacelle Gondel góndola* nacelle* nacelle 机舱noise Schall,
Lärmruido bruit støj 噪声
Obstacle Hindernis obstáculo obstacle lægiver 障碍occupational safety
Betriebssicherheit
seguridad* en el trabajo
sécurité* du travail
arbejdssikkerhed
职业安全offshore wind energy
Offshore-Windenergie
energía* eólica marina
énergie* éolienne offshore
offshore vindkraft
海上风能
operation and maintenance costs
Betriebs- und Wartungskosten
costes* de operación y mantenimiento
coûts d'exploitationet d'entretien
drifts- og vedligeholdelses-omkostninger
运行和维护费用
Park effect Parkeffekt efecto del parque
effet de parc parkvirkning 风场效应pitch control Pitchregelu
ngregulación* por cambio del ángulo de paso
contrôle à calage variable
pitchregulering
桨距控制
pole changing generator
Generator mit Polumschaltung
generador con número de polos variable
génératrice* à pôles commutables
polomkobbelbar generator
可变极发电机
(magnetic) pole
(magnetischer) Pol
polo (magnético)
pôle (magnétique)
(magnet) pol (磁)极porosity Porosität porosidad* porosité* porøsitet 多孔性power coefficient(rotor) power coefficient
Leistungsbeiwert (des Rotors)
coeficiente de potencia (del rotor)
coefficient de puissance (du rotor)
(rotorens) effektkoefficient
功率系数(转轮)
power curve Leistungskurve
curva* de potencia
courbe* de puissance
effektkurve 功率曲线power density Leistungsdi
chtedensidad* de potencia
densité* de puissance
effekttæthed 功率密度power of the wind
Leistung des Windes
potencia* del viento
puissance* du vent
vindens effekt
风功率power quality Leistungsqu
alitätcalidad* de potencia
qualité* du courant
spændingskvalitet
电能质量
558
électrique
(electrical) power
(elektrische) Leistung
potencia* (eléctrica)
puissance* (électrique)
(elektrisk) effekt
(电)电源Q
Rated power, nameplate power
Nennleistung
potencia* nominal
puissance* nominale
mærkeeffekt 额定功率,铭牌功率
Rayleigh distribution rectifier
Rayleigh-Verteilung
distribución* de Rayleigh
distribution* de Rayleigh
Rayleighfordeling
瑞利分布
rectifier Gleichrichter
rectificador redresseur ensretter 整流器renewable energy
erneuerbare Energie
energía* renovable
énergie* renouvelable
vedvarende energi
可再生能源rotor area(swept) rotor area
Rotorfläche área* del rotor (de barrido del rotor)
surface* balayée par le rotor (ou le l'hélice)
(bestrøget) rotorareal
转轮(扫掠)面积
rotor blade Rotorblatt pala* pale* rotorblad, vinge
转轮叶片rotor (of a generator)
Rotor (des Generators)
rotor (del generador)
rotor (d'une génératrice)
rotor (på generator)
(发电机)转轮rotor (of a wind turbine)
Rotor (der Windkraftanlage)
rotor (de una turbina eólica)
hélice*, rotor (d'une éolienne)
rotor (på vindmølle)
(风力机)转轮
roughness class
Rauhigkeitsklasse
clase* de rugosidad
classe* de rugosité
ruhedsklasse粗糙度等级roughness length
Rauhigkeitslänge
longitud* de rugosidad (o parámetro de aspereza)
longueur* de rugosité
ruhedslængde
粗糙尺度
roughness rose
Rauhigkeitsrose
rosa* de las rugosidades
rose* des rugosités
ruhedsrose 粗糙度玫瑰图safety Sicherheit seguridad* sécurité* sikkerhed 安全性Scale parameter (Weibull distribution)
Skalierungsparameter (Weibull-Verteilung)
parámetro de escala (distribución de Weibull)
paramètre d'échelle (distribution de Weibull)
skalaparameter (Weilbullfordeling)
尺度参数(威布尔分布)
sea bird Seevogel ave marina oiseau de mer
søfugl 海鸟sea breeze Seebrise brisa* marina brise de mer søbrise 海风
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*
shadow casting
Schattenwurf
distribución* de las sombras
projection* d'ombres
skyggekastning
阴影
shape parameter (Weilbull distribution)
Formparameter (Weibull-Verteilung)
parámetro de forma (distribución de Weibulll)
paramètre de forme (distribution de Weibull)
formfaktor (Weilbullfordeling)
形状参数(威布尔分布)
shelter effect Windschatten eines Hindernisses
efecto de resguardo
effet d'obstacle
lævirkning 遮掩效应
sinusoidal sinusförmig sinusoidal sinusoïdal sinusformet 正弦曲线site, siting Standort,
Standortwahl
emplazamiento
site, choix de site
plads, placering
场址,选址
(generator) slip
(Generator-) Schlupf
deslizamiento (del generador)
glissement (d'un générateur)
(generator) slip
(发电机)滑差
soft start "weiches" Einschalten
arranque suave
démarrage souple
blød indkobling
软启动sound Schall sonido son lyd 声音speed up effect
Beschleunigungseffekt
efecto acelerador
effet de survitesse
speed up effekt
加速效应stall Strömungsa
briß, Stallpérdida* de sustentación ("stall")
décrochageaérodynamique("stall")
stall 失速
stall control Stallregelung, Regelung durch Strömungsabriß
regulación* por pérdida aerodinámica ("stall control")
régulation* par décrochage aérodynamique
stallregulering
失速控制
star connection
Sternschaltung
conexión* estrella
connexion* (ou couplage) en étoile
stjerneforbindelse
星形连接
stator Stator estator stator stator 定子stream tube Stromröhre tubo de
corrientetube de courant
strømrør 流管structural Strukturdyn dinámica* dynamique strukturdyna 结构动力学
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dynamics amik estructural desstructures (dynami-que structurale)
mik
synchronous generator
Synchrongenerator
generador síncrono
générateur(ou génératrice*)synchrone
synkrongenerator
同步发电机
synchronous speed
Synchrondrehzahl
velocidad* de sincronismo
vitesse* synchrone
synkron hastighed
同步速
Three phase alternating current
Dreiphasen-Wechselstrom
corriente* alterna trifásica
courant alternatif triphasé
trefaset vekselstrøm
三相交流电
thyristor Thyristor tiristor thyristor thyristor 晶闸管tower Turm torre* tour* tårn 塔架tripod foundation (offshore)
Dreibein-Fundament (Offshore)
cimentación* (marina) en trípode
fondation* à trois pieds (le trépied) (offshore)
tripod fundament (offshore)
三脚架基础(海上)
tubular tower Rohrturm torre* tubular tour tubulaire rørtårn 钢管塔架turbulence Turbulenz turbulencia* turbulence* turbulens 湍流(rotor blade) twist
Verwindung (des Rotorblatts)
torsión, alabeo (de la pala)
torsion* de la pale
twist, vridning
(转轮叶片)扭曲
Upwind (machine)
Luvläufer (máquina*) con rotor a barlovento
éolienne* face au vent
forløber 上风向(风机)
Variable (rotational) speed
variable (Drehzahl)
velocidad* (de giro) variable
vitesse* (de rotation) variable
variabel (omløbs)hastighed
可变(旋转)速度
vertical axis wind turbine (VAWT)
Vertikalachser, -läufer
aerogenerador de eje vertical
éolienne* à axe vertical
vertikalakslet vindmølle
垂直轴风力机(VAWT)
viscosity Viskosität viscosidad viscosité* viskositet 粘性vortex generator
Vortexgenerator
generador de torbellinos
génératrice* de vortex
vortex generator
涡流发生器
Wake effect Nachlauf-Effekt
efecto de la estela
effet de sillage
kølvandseffekt, wake
尾流效应
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effekt, slipstrøm
weak grid schwaches Netz
red* débil réseau faible svagt net 薄弱的电网Weilbull distribution
Weibull-Verteilung
distribución* de Weibull
distribution* de Weibull
Weilbullfordeling
威布尔分布wind energy Windenergi
eenergía* eólica
énergie* éolienne
vindenergi 风能wind map Windkarte mapa eólico carte* des
ventsvindkort 风能地图
wind power Windkraft potencia* eólica
puissance* éolienne
vindkraft 风电wind rose Windrose rosa* de los
vientosrose* des vents
vindrose 风玫瑰图wind shade Windschatt
enabrigo (o sombra) del viento
abri, effet d'abri
lævirkning 风影
wind shear Windscherung
cizallamiento (o cortadura) del viento
cisaillement du vent
vindgradient, wind shear
风切变
wind turbine Windkraftanlage
aerogenerador, turbina* eólica, aeroturbina*
éolienne*, aérogénérateur
vindmølle, vindkraftanlæg
风力机
wind vane Windfahne veleta* girouette* vindfane 风向标XYaw Windnachfü
hrungorientación* orientation* krøjning 偏航
yaw mechanism
Windnachführ-mechanismus
mecanismo de orientación
dispositif d'orientation
krøjemekanisme
偏航机构
Z
>* =
femenino* = féminin
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© Copyright 1997-2003 Danish Wind Industry Association
1997-2003丹麦风电产业协会版权Updated 1 June 2003
2003年 6月 1日更新http://www.windpower.org/en/tour/wres/index.htm
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