Post on 30-Dec-2015
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太陽光發電系統介紹
Solar cell 篇
Motech Industries Inc.
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Solar cell 種類
種類 備註1.Crystalline silicon solar cell A. Monocrystalline B. Multicrystalline
88% Market數百 micronsC-Si
2.Thin film solar cell A. Amorphous silicon B. Polycrystalline materals
12% Market1 microna-Si (amorphous)
C1. Cd Te C2. Copper indium diselenide (CIS or CIGS)
金屬與另一惰性金屬接觸時所產生之電化腐蝕現象
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Solar Cell 製作
A. 將 n-type 摻雜，塗佈在 p-type 之表面。B. 印刷導引線 ( 光與電阻性損失最小 ) 最大光
吸收及電流收集。
Silica(SiO2)
高溫去氧化 冶金級98%pure
Monosilane
複晶矽 單晶矽晶碇10-9
CZFZ 切割
拋光 清洗 蝕刻 表面處理 P/N擴散 電漿蝕刻 抗反射模沈積
電極網印 燒結 鍍錫 Solar Cell
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price 信賴度
矽Single 15~24 B A+
Multi 10~18 A A
a-Si 8~13 A+ A
化合物GaAs 19~32 B- A+
CdTe 10~15 A A
CuInSe2 10~12 A A
染料 TiO2 7~11 A+ B
有機半導體 2 以下 A+ B-
Solar cell 比較
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PV Module Performance Rating
測試環境 1. The peak watt (Wp) rating A. Temp B. Solar radiation (AM1.5) 但如此實驗室的狀態不實際。 2. NOCT-normal operating cell temperature 在一定之室外溫度下所測得之最大功率，雖較 Wp 為低，但較真實。
3. AMPM standard global-average day : light level, ambient temperature, air mass
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1. Power Output ：一天內產生之 peak power or avg power 。 (watts) 2. Energy Output ：
(Wh) 在一定之週期下評估以上 3 項目
3. Conversion efficiency ： energy output from array energy input from sun
評價單位： 1EEE 、 ASTM (American Society for Testing and Materials)
A B C
Wh/m2
Wh/Kg Wh/$
x 100%
Electrical Performance
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影響日照的因素
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光波頻譜
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V
I
Power is either generated or dissipated, depending on the
quadrant you are in.
1ST Quadrant:
Dissipation
3D Quadrant:
Dissipation
2ND Quadrant:
Generation
4TH Quadrant:
Generation
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IV
Dark Characteristic Light Characteristic
I
V Power Generating Region
Power Dissipating
Region
Power Dissipating Region
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The VI characteristic of a solar cell is usually displayed like this:
V
IV
I
The coordinate system is flipped around the voltage axis.
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Power is a function of position along the VI characteristic. At the
intercepts, it is minimum - zero - increasing to a max near the knee of
the curve.
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Set #1: ISC , PMAX , VOC
(0.5V, 0 mA) V I = 0 mW
(0.43 V, 142 mA) V I = 61 mW
ISC
VOC
PMA
X(0V, 150 mA)
V I = 0 mW
Some typical values
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The short circuit current ISC is a linear function of sunlight intensity. The open circuit voltage VOC is not.
(VOC is weakly dependent on temperature.) Recall from Part I
that sunlight intensity is measured in terms of a solar constant with
units such as mW/cm2.
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I = ISC
R = 0
Does it surprise you that the current at short circuit is not infinite? Or that a current can flow with no voltage? Where does the energy originate?
Answer to Question #1:
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I = 0
R =
Answer to Question #2:
+
_V = VOC
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ISC
VOC
Hyperbola for P = PMAX
Point of tangency
Voltage at max power
Cu
rren
t at
max p
ow
er
Answer to Questions #3 and #4 (cont’d):
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Set #2: RS , RSH
ISC
VOC
The slopes of these lines are characteristic resistances.
RSH
RS
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Questions:
1. Which resistance is higher, the measurement at ISC or the measurement at VOC ?
Remember: R = V/I !
2. Physically, what do you think these resistances represent?
3. As a solar cell designer, what is your preferred ideal value?
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Answers to Questions #1 - #3:
The resistance at ISC is extremely high. In an equivalent circuit model of a solar cell, it represents a shunt resistance.
The resistance at VOC is extremely low. In an equivalent circuit model of a solar cell, it represents a series resistance.
Both of these resistances are internal, and represent energy dissipation mechanisms in the cell.
Ideally, a designer would like zero series resistance and infinite shunt resistance.
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ISC
RS
RSH
RLOAD
Equivalent circuit for a solar cell with load. Internal resistances RS and RSH represent power loss mechanisms
inside the cell.
Cell
Cell
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ISC
RS = 0
RSH =
RLOAD
The ideal solar cell would have no internal losses at all! What would the VI characteristic of THIS cell look like?
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ISC
VOC
RSH =
RS = 0
The Ideal Solar Cell
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Notice that the area under the rectangle = PMAX for the ideal cell.
For this cell,PMAX = VOC ISC
ISC
VOC
The Ideal Solar Cell
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ISC
VOC
Set #3: Fill Factor
In fact, PMAX/(ISC VOC) measures the cell’s quality as a power
source. The quantity is called the “Fill Factor.”
Can you see why?
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Questions:
1. What is the ideal fill factor?
2. Can the ideal cell ever be built? Why or why not?
3. For a cell with these parameters:
(0V, 150mA), (0.43V, 142mA), and (0.5V, 0mA)
calculate the fill factor.
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Answer to Question #1:
The ideal fill factor is unity. Why?
Answer to Question #2:
An ideal cell might be approximated, but never actually built. Nature is never ideal as humans think about “ideal.”
Answer to Question #3:
The fill factor is:
(0.43V 142mA)/(0.5V 150mA) = 0.81 = 81%
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太陽光發電系統介紹
Inverter 篇
Motech Industries Inc.
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變流器技術 太陽光電池與電池產生直流電壓與電流，
然而負載所需為交流功率時，那麼就需要 Inverter 來轉換 DC/AC ，一般來說可利用 Inverter 轉換 DC 電源成為交流單 /三相、 50/60Hz 、 117/220V ，而轉換功率可從數百 Watts 到數千 KWatts ，較大功率輸出的 Inverter 其輸出電壓可達 480V 甚至更高。
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Inverter 種類種類 備註
1. 獨立型 A. 弦波 B. 修正弦波 C. 方波 2. 併聯型 A. 單一 MPPT B. 多個 MPPT 3. 混合型
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變流器的功率額定
1. 功率是時間的函數 2. 突波功率 3. 溫度對額定功率的影響
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變流器的效率 1. 效率視負載而定 2. 電感性對電阻性負載 3. 效率測量的設定
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變流器的波形 1. 方波 2. 修正方波或修正弦波 3. 弦波
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變流器電路 1. 先變頻再變壓 2. 先變壓再變頻 3. 波寬調變 4. 多工變壓器
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市電併聯混合型變流器 More flexibility on power
management.
Provides limited power for critical loads incase of power failure.
Requires Battery maintenance schedule.
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變流器特徵總合 AC OUTPUT PARAMETERS DC INPUT PARAMETERS PROTECTION GENERAL SPECIFICATION
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AC OUTPUT PARAMETERS Output Voltage Output Frequency Continues AC output rating Waveform Output Power Factor THD DC control injection Efficiency
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DC INPUT PARAMETERS
Input Power control MPPT Range
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PROTECTION
Internal Protection System Anti islanding Protection signals/contacts Internal Shutdown
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GENERAL SPECIFICATION 1
Parallel Operation Local Operator Interface Front Panel LCD Display Computer Ports Isolation Remote Access Parameters Fault log Communications
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GENERAL SPECIFICATION 2 Output Date Files Operating Temperature Rang Humidity Enclosure Printed Circuit Boards Standby Tare Losses Noise Aux. ADC Port
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選擇變流器特性之進一步探討 1. 直流輸入電壓 2. 電壓調整率 3. 可服務性 4. 臨界點調整 5. 併聯成較大功率源
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選擇變流器特性之進一步探討