Mtkvari HPP_Dj344Nitva

8/3/2019 Mtkvari HPP_Dj344Nitva

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The Ukraine

Open Joint-stock Company

Ukrhydroproject

HPP MTKVARI

on r. Mtkvari in Georgia

Project

Preliminary Technical Task for Preparation of Technical Offer on Hydro generator and

Excitation System supply

NOTE

1490-25-T3

2009


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The Ukraine

Open Joint-stock CompanyUkrhydroproject

HPP MTKVARI

on r. Mtkvari in Georgia

Project

Preliminary Technical Task for Preparation of Technical Offer on Hydro generator and

Excitation System supply

NOTE

1490-25-T3

The present documentation is elaborated under the controlled conditions, specified by the

Quality Management System, functioning in OJSC Ukrhydroproject in accordance with ISO

9001:2000 and certified BVQI requirements; certificate No 195340

Deputy Technical Dorector (signature) N. P. Volkov

Project Chief Engineer (signature) V. S. Romashko

2009

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Project documentation is elaborated according the current norms, rules and standards.

Project Chief Engineer (signature) V. S Romashko

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CONTENTS

INTRODUCTION 5

1. General Requirements 6

2. Nameplate data and general quantities 7

3. Operational conditions 94. Congestions and Coefficient of efficiency 10

5. Allowable temperature 11

6. Inductances 12

7. Generator system arrangement 13

8. Frame and stator core structure 14

9. Stator coil 15

10. Rotor 17

11. Upper bracket 19

12. Lower bracket 20

13. Thrust bearing 21

14. Pilot bearings 2215. Oil baths 23

16. Breaking system 24

17. Ventilation and cooling system 25

18. Thermal control 26

19. Fire-fighting equipment 27

20. Monitoring system 28

21. Transportation, maintenance and installation 29

22. Factory acceptance tests 30

23. On-site tests 31

24. Generator excitation system 32

25. Scope of the technical offer 33

Attachment A. Version maximum operation level 1015m, dead storage level 1010,0m,

Q=57 m3/c. Outline drawing of the aggregate 34

REGISTRY OF MODIFICATIONS 35

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INTRODUCTION

The present preliminary technical task is drawn up as a part of the HPP Mtkvari construction

project in Georgia in order to hold a competitive internal tender between possible suppliers of

Hydro Power equipment and preliminary determination of the supplier and main preliminaryspecifications of the hydro power equipment, which will be used during the HPP project dam

construction works and determination of the HPP technical-economic values.

Designed HPP appears a source of peak capacity (point action).

2 hydro equipments should be installed at the station.

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1. GENERAL REQUIREMENTSAll parts of the hydro-generator (further generator) should be elaborated and made so that they

should bear electric, mechanical, thermal and any other load, which may be caused due togenerator operation in any operational mode without any damage, including due to short circuit,

asynchronous powering on, over speed.

Alternator design, included its bearing parts should not cause improper vibrations, as well as

occurrence ofresonant effects.

Alternator design should bear earthquake measuring nine (9) on the MSK-64 without receiving

any damage.

Installation height up to 1000m above sea level.

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2. NOMINAL DATA AND GENERAL QUANTITIESGenerator continuous maximum rating with nominal voltage,

nominal set speed, rated power factor, system frequency rating and

cooling-air temperature of 35o

C, kVA 290002.2. Nominal active power, kVA 23200

2.3. Rated power factor 0,8

2.4. Nominal voltage (linear), B 10500

2.5. Voltage limits (from reference values), % 5,0

2.6. System frequency rate, hertz 50

2.7. Frequency variation limits (from reference values), % 1,0

2.8. Nominal set speed, r/min 428,6

2.9. Maximum frequency rating

(is specified by the designer of the turbine), r/min 760

2.10. Stator winding phase number 3

2.11. Stator winding phase connection scheme star2.12. Direction of rotation (top view) clockwise

2.13. short-circuit ratio, no more then 1,0

2.14. Generator moving armature rrotative moment

(specified by the Turbine designer), ton-meter2 350

2.15. Air-cooling unit water coolant input maximum temperature,oC 28

2.16. Output air cooler temperature, oC 35

2.17. Harmonic distortion (TIF according to IEC standards), % 1,5

2.18. Stator and rotor insulation class (according to GOST 8865) F

2.19. Design operational temperature, oC 75

2.20. Stator windings testing voltage before generator putting in

commission (50,0 hertz, continuance 1,0min.) kV 19,2

2.21. Rotor windings testing voltage before generator putting in

commission (50,0 hertz, continuance 1,0min.)- not less, kV 1,2

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3. OPERATIONAL CONDITIONS

3.1.Generator should provide continuous operation with nominal quantities according to

article 2, in this case stator winding temperature (according to the specified temperature

values) should not exceed 120o

C, rotor winding temperature (according to the electricalresistivity method) should not exceed 130 oC.

Generator should provide positive operation with 105% nominal capacity, in this case

winding temperature may be by 5,0 oC higher then during operation with nominal capacity.

3.2. Designer should provide with generator load diagram (acceptable capacity values during

its operation with different power factor from 0,0 up to 1, 0 as in the overexcitation mode, as

well as in the underexcitation mode.

In the technical offer designer should include reactive power values during generator electric

main operation in the charging mode (capacitive load) indicating possible operation

continuance in the said mode.

3.3. Generator should provide possible increase of the active capacity up to nominal (29000

kVt) by means of increase of capacity ratio up to 1,0.3.4. Generator should provide nominal capacity operation during nominal capacity ratio and

nominal speed of rotation during electric potential limit deviation on connection terminals on

5, 0% and limit deviation of network power frequency on 1,0% of nominal values.

Additionally, during operation with increased electric potential and lowered frequency, total

of electric potential deviation and frequency absolute values should not exceed 5, 0%.

Generator should provide continuous operation with electric potential limit deviation from

nominal value not exceeding 10,0%. During electric potential limit deviation from 5,0%

up to 10,0% of nominal value, Designer should include in technical offer values of

possible continued load of the generator and additionally indicate possible continuance of

instantaneous demand during limit deviation of 15, 0% of nominal value and frequency

more then for 1.0%.

During generator operation with indicated electric potential and frequency deviations

additional increase of the temperature over the nominal mode temperature should not be

more then 10,0oC and should not exceed value relevant of class F insulation.

3.5. Generator should provide continuous operation during asymmetric load, if operating

current does not exceed nominal value and current difference in phases does not exceed

20,0% of nominal value.

Generator should provide short-time duty in emergency frames, during which value of

negative sequence current square product in relative unit during possible period of operation

in the given emergency mode should not be less then 20,0 seconds.

3.6. Generator should provide short-time duty in emergency conditions with overload ratiofor the stator current equal to 2,0 of nominal value with continuance of 1,0min.

In the Technical offer the Designer should indicate possible number of the given current

overloads per year.

Generator rotor winding should allow double nominal current excitation field with not less

then 50,0 seconds duration.

3.7. Generator should be designed and manufactured to bear sudden three phase short- circuit

connection terminals with electric potential of idle running equal to 105% nominal.

3.8. Generator should be designed and manufactured to bear maximal rotation frequency

equal to 760 r/min. Meanwhile rotor materials rated mechanical stress should not be more

then 95% of yield stress, and rotor rim distortion should be less then air (mechanical) gap.

3.9. The generator should be switched on by the method of exact automatic synchronization.Switching the generator on by self-synchronization in emergency frames should be possible.

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3.10. Generator should make not less then 1000 start-ups per year and not less then 4 start-

ups per day.

3.11. Noise level (sound average level) on distance of 1,0 m from the upper bracket should

be not more then 85 dBA.

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4. CONGESTIONS AND COEFFICIENT OF EFFICIENCYIn the Technical offer the Designer should indicate Congestion and coefficient of efficiency for

two values of capacity ratio ( 0,8 and 1,0) and for different load values (40%, 80% and 100 % of

the nominal load).Congestion should include: congestions in the stator core, congestions in the pole extensions,

congestions in stator winding copper, additional congestions, congestions for the ventilation and

rotor air adhesion, congestions in bearing parts and axial bearing of the generator, congestions of

the contact rotor rings. Congestions in stator winding copper and rotor should be equal to rated

operational temperature 75,0 oC.

The designer should guarantee the following values of the efficiency coefficient during nominal

load:

- during nominal capacity ratio (0,8) 98, 1%;- during capacity ratio equal to 1,0 98, 5%.

The designer should indicate weight average efficiency coefficient during nominal capacity ratio

(0,8) and capacity ratio equal to 1, 0.Meanwhile the following weight ratios should be accepted:

- for capacity 40% nominal 0, 30,- for capacity 80% nominal 0, 40,- for capacity 100% nominal 0, 30.

Congestions and efficiency coefficient, as well as allowed deviations should be specified

according to standard GOST 25941-83 and IEC 60034 norms.

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5. ALLOWABLE TEMPERATURESThe designer should guarantee the following temperature values during working with the

quantities indicated in the p. 2.1:

- Stator winding temperature increase 85 K;- Rotor winding temperature increase 95 K;- Stator core temperature increase 85 K;- Contact rings temperature increase 85 K.- Indicated increases of the temperature should be relevant to the aircoolers outlet cooling

temperature equal to 35o C.

- Axial bearing segments temperature 80oC;- Pilot bearing segments temperature - 75 oC;- Cool oil temperature in oil-bath - 45 oC;- Hot oil temperature in oil-bath - 75 oC

Methods of measurement of the temperature should be relevant to GOST 11828-86

standard and IEC 60034 norms.

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6. INDUCTANCES

The designer should guarantee the following values for inductances (non-saturated values):

- Synchronous inductance along direct axis (not more) 110%;- Transition inductance along direct axis (not more) 33%;- Sub-transient inductance along direct axis (not less) 22%.

The indicated inductances are relevant to nominal capacity 29000 kBA.

Methods of the inductances specification and allowable deviations should be according to

GOST 10169-77 standard and IEC 60034 norms.

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7. GENERATOR SYSTEM ARRANGEMENT

According to the system arrangement the generator should be vertical-shaft, of suspended type

(the axial bearing located above the rotor) with two bearing pilots (shaft W41 according to DIN

42950 norms).Turbine pit diameter 2650mm.

Rotor should rest upon immovable segments of the axial bearing, which should be located in the

upper bearing bracket. Upper bearing-pilot should be located in the central part of the upper

bracket and should be located in the same oil bath together with the axial bearing. Lower

bearing-pilot should be located in the central part of the lower bracket.

The designer has right to offer generator other system arrangement.

Grounded explanations for the usage of the other system arrangement should be detailed in the

Technical offer.

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8. FRAME AND STATOR CORE STRUCTURE

Structure of the frame and stator core should be specified by means of transportation of the

generator to the Power station and its installation.

In the Technical offer the designer should submit detailed description of the indicated operations(activities) (method of its transportation and installation).

8.1. Stator frame should be of a ring structure, welded of horizontal crossbars, vertical crossbars

and outside planking. Upper ring of the stator frame should serve as a support under the upper

bracket, and the lower ring should be used forstrengthening stator to the base. On the outer side

of the surface air-coolers should be installed. Outer side surface of the frame according to the

Designers decision may have a form of a cylinder or equilateral polygon. The central portion of

the frame, to which stator core is attached, should consist of several parallel shelvings, between

which strengthening ribs should be installed.

Upper and lower rings of the stator frame should consist of one shelving and it should be made

of a thicker iron plates then the central ones, as they should reinforce upper bracket and keep

stator attached to the base. Strengthening of the stator frame should give possibility of the statorradial movement due to possible widening of the stator core from the temperature.

According to the transportation and installation conditions stator frame may be dismountable

consisting of several sectors. Decision regarding number of sections and structure jointings is

made by the Designer.

In the frame of the stator steel wedges should be installed, on which stator core is erected

(assembled).

8.2. Stator core should be assembled from the segments of high quality electro-technical steel of

the width of 0,5mm (of M270-50A mark according to the European standard EN 10106). Each

segment of the core should be coveredd by the electro-insulating varnish of F class from both

sides. Electro-technical steel should have specific losses value not more then 1, 1Vt/kg for the

induction 1,0 TL and frequency 50,0 hertz.

Core segments should be made by means of compound die-forging.

Whole length of the stator core should be divided into blocks, between which ringed ventilation

holes are considered, which originate from vent spacers of non-magnetic steel. Width of the

ventilation hole should be not less then 6,0 mm. Height of central blocks of the core should be

not more then 50,0mm. Two or three marginal blocks from each side of the stator core should be

lower, but not low then 30,0mm.

After pressing, the stator core should finally be pinched together with steel studs with the help of

pressure bearing manifolds (terminal blocks). Bracing studs should be located between the stator

frame and thebackof the core. Maximum mechanical load on the stud should not exceed 2/3 of

the stud material yield point. Bracing stud bolts should be made of magnetic steel. Assembly ofthe stator core should be performed at the factory of origin or at the HPP depending from the

acceptable means of transportation and installation.

In the offer the designer should submit detailed background of the made decisions regarding

transportation and mounting of the generator.

After finishing the assembly the stator core should be tested for determination of existence of

local (in-situ) heatings in the core and for specifying value of specific losses.

The indicated tests should be conducted according to the Designer norms.

The designer should take relevant steps not to allow possibility of stator core vibration during its

normal operation.

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9.STATOR COIL

Stator coil should be double layered, bar winding or coil winding and according to the

connections layout it should be loop winding. Transposition of conductor strands should be

conducted (transposition of the conductor strands during bar winding should be performedaccording to the Roebel method).

In the Technical offer the designer should submit detailed background for the usage of the

accepted type of stator winding.

Stator winding should provide performance of the following fundamental requirements:

- During idle running mesh voltage variation should satisfy quality norms of electricpower;

- winding insulation should have enough breakdown and mechanical strength, so to make possible provision of the generator normal exploitation in case of operating tensions

during whole service length of the generator and bear the operational and testing voltage

building-up;

- winding separate phases should be symmetric;- winding temperature should not exceed values acceptable according to the norms;- winding and its clamps should stay mechanically strong for any unfavorable operational

mode, as for normal, as well as for the emergency ones;

- Vibration amplitude of the side members of the end coils (stator end winding) should belimited in each operational mode, and the self-resonant frequency should be sufficiently

removed from the generator doubled frequency (100 hertz);

- Coil brace along its whole length should be sufficiently rigid and should excludedangerous movements of the coil items.

For the purpose of a winding bar insulation (coils), constant insulation should be used at the

thermo active connectors (binders) of F class. All insulation items, used during placing

(stowing) the winding in stator core slots, and during their bending (bracing), should be

made of class F materials according to GOST 8865-87.

During manufacturing the winding bar insulation (coils) vacuuming should be performed be

means of special modern devices.

During designing the structure of high-voltage insulation, special attention should be paid to

decrease inhomogeneous-ness of the electrostatic field in insulation and usage of effective

anti-discharge coating.

For removing possible electrical discharges between the winding bars (coils) and stator core

slot sides, as well as for limitation of the winding vibration, their tight stowing in the stator

slots should be provided.

Coil bonding in accordance with the electrical scheme of the winding bonds should be made by means of the brazing, containing silver. The said bonds (connections) should provide

good electrical contact, high mechanical strength and increased thermal resistance.

Stator winding slot sector coil brace should be made with the help of slot wedges, made of

the insulation material of F class.

Stator end winding coil brace should be made by means of retaining rings, preventing to

their movement in radial direction. The retaining rings should be made of non-magnetic

materials. The retaining rings should be fastened to the clamping plate of the stator core.

Central and neutral terminals of the stator winding should be taken out of the stator frame

through the frame windows. Each winding phase should have one major (central) and one

neutral terminal. Stator winding phase connections should be made by Y-junction.

Succession of terminals and theirplacement should be separately agreed with the Client.Terminals should be protected from accidental ingress (impact) of foreign items (materials).

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The designer should express in the Technical offer his experience in stator winding

production of generators of similar capacity and nominal electric potential.

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10. ROTOR

Rotor should consist of rotor shaft, reel, rotor rim, winding excitation poles, current lead

with collectors and locking ring.

10.1. Rotor reel and rim types should be specified according to the value of the outerdiameter of the rotor rim, nominal for maximum rotation value. At the same time necessary

rigidness and mechanical strength of the rotor reel and rim should be provided. The designer

should offer production of the reel and the rim as an integrated unit. In this case the reel and

the rim should be made of separate (solid) disks. Laminated rotor rim of laminated segments

may be offered.

In the Technical offer the designer should submit the detailed background for making any

type of technical decision.

10.2. Generator shaft may be forged or forged-bonded (welded). Rotor shaft may serve as

rotor reel, on the peripheral unit of which slots are made, in which poles are located and

strengthened..

In the Technical offer the designer should submit background for making any type ofdecision.

Central hatchway is considered in the shaft. Connection with the reel (reel and rim) with the

shaft should be performed by means of interference fits of these tapping points. Interference

fit should provide torque transfer.

The designer should foresee all necessary issues of the generator shaft connection with the

turbine shaft, so that unified line of shafting is provided for the hydraulic unit.

The indicated connections of the generator and turbine shafts should be relevant to the

norms and requirements of the turbine and generator manufacturing plants, as well as to the

IEC norms.

10.3. Generator rotor pole should consist of the core, field coil and amortisseur winding. The

core should be made of laminated sheet steel with solid jaws (clamps) along the ends and

braced with steel studs.

Core should be tied to the rotor rim by means of tee-roots or dovetail joint.. The sheets of the

laminated core pole should be made of steel of width not less then 1.5 mm. The indicated

width should be specified by mechanical strength of the pole tip joints and edges. Slots for

amartisseur winding should be considered in the polar tips.

The designer may offer usage of massive core poles. In such a case polar tips should serve as

amartisseur winding. In the Technical offer the Designer should give background for

necessity and effectiveness of the usage of the massive core poles.

The bending structure of the rotor poles to the rotor rim should be made so to easily remove

and change the poles.10.4. Field coils should be performed of slab copper bus of special profile, increasing the

surface of the coil cooling. The winding turns can be made by means of winding copper bus

on the rib or welding (square coil). The field coil should be isolated from the core of the pole

and from the rotor rim. As an insulation for the core pole a rigidly molded tube made of

textile glass should be used. Usage of insulation materials made of asbestos are allowable.

Field coil turns should be isolated from each other by glass textolite insulation. Insulation

materials should be of F class according to the GOST 8865-87.

In order to avoid possible radial and tangential movement of the coil in relation to the core,

special fixation of the coil should be considered. The construction of inter-polar bond

(connection) should have necessary hardness and flexibility. During rotor rotation,

centrifugal force influences coil turns. Tangential component of this force tends to bend theturns of the coil. Special measures should be considered against the bending and turning the

coil turns over.

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Amortisseur winding should be of direct and quadrature type. Sufficient holding (bond)

strength of traversal components of massive copper pole-segments of the amortisseur

winding and of elastic pass by-pass bonds to the rotor rim should be provided.

10.5 Excitation current should be provided to the field coil through contact rings, installed on

the rotor axle and carbon-baked brushes, installed on the traverse around the rings.

Current lead from the contact rings to the field coil should be made of slab copper busses,

which should be strengthened to the rotor shaft, rim and reel by means of insulation sockets.Possibility of variation of polarity of the contact rings should be considered.

Brushes and contact rings should be protected from oil and oil steam from the brackets.

Insulation of contact rings should be made of water and oil proof materials. System for

protection stator and rotor zones from getting dust from brushes should be considered.

Possibility of free access to the generator contact rings during hydro turbine operation

should be considered.

10.6. Locking ring should be fastened to the rotor lower end part. The locking ring could be

made of separate segments. The locking ring and the segments should have radial notches for

compensation of thermal widening of the superficial layer during break.

10.7. Gear wheel should be considered for measuring rotation frequency of the hydro turbine.

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11. UPPER BRACKET

Upper bracket should be load bearer (support) and pass strengths from axial bearing and

simultaneously radial forces from pilot bearing to the base through the stator frame axial.

Cruciform one-piece bracket with four legs should be used.The designer could offer another type of bracket, on basis of the background given in the

Technical offer.

Axial bearing should be placed inside the central part of the bracket. In the general oil bath

together with the bracket, pilot bearing should be installed.

The designer could offer another method of the bracket and pilot bearing placement in the

upper bracket, on basis of the relevant background, submitted in the Technical offer.

In radial direction the legs of the bracket should be strengthened by means of jacks, strutted

in plate-bases.

Vibration ratio (excursion) of the bearing bracket in the horizontal direction during all

running modes should not exceed 0,07 mm.

Bearing bracket should have necessary rigidness and mechanic strength to resist thefollowing loads:

- horizontal vibrations, caused due to magnate and mechanical misbalance, which arepassed through the pilot bearing;

- vertical vibrations, caused due to the existence of the variable components of the axialload on the turbine running wheel, which are passed through the axial bearing;

- Axial strengths from the mass of generator and turbine swiveling (rotating) parts andaxial pressure.

Bracket structure should provide possibility of placement and convenient provision of the

service for the axial bearing, bearing part, contact rings with brushing device, oil baths, pipes

with armature and other branching points of the generator.

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12. LOWER BRACKET

The lower bracket should be of a beam type without connectors among the legs.

Their dimensions should be sufficient for installation and should provide possibility to serve

conveniently lower pilot bearing part and its oil bath.Lower bracket should take up horizontal loads, passing over by the pilot bearing part and

axial loads from breaks-jacks.

The designer can offer another type of the lower bracket on basis of the backgrounds,

submitted in the Technical offer.

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13. THRUST (AXIAL) BEARING

Thrust bearing structure should satisfy following fundamental requirements:

- Allow load distribution between thrust bearing segments with sufficient faultlessoperational accuracy;

- Allow segments biplane tilt down, creating wedge gap between the segments and thedisc;

- Keep sufficiently plain rubbing surface during hydraulic unit start up and operation;- Create correct oil circulation in the thrust bearing bath and provide disposal of

discharged losses;

- Avoid displacement of the segments the during rotor rotation and during rotor lifting bybrakes and jacks.

Single row thrust bearing with screw-type base segments should be used.

The designer can offer different type of the thrust bearing on the condition if he submits its

detailed background in the Technical offer.

Accepted thrust bearing segment dimensions should be such, to make the oil layer widthsufficient for avoiding possibility of creation of screw-type base metal contact during

nominal mode of generator operation, and the temperature of the segments should not exceed

allowable values. Temperature limit for the heating of the thrust bearing segments should

not exceed 80.0 oC.

Measures to avoid bearing currents should be foreseen.

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14. PILOT BEARING

Pilot bearing should be of segmented type, working with self-oiling (without assisted

circulation of the oil). The segments should be part of the ring and should be located in the

oil bath around the spindle.Screw-type base of the segments should be covered by babbit metal.

In radial direction each segment should have a support in the point of the spherical surface

of the adjustable bolts (screws). Eccentricity for possibility of creation of the oil wedge

should be foreseen.

The designer can offer other type of thrust bearing, on basis of submittance detailed

background for the offer in the Technical offer.

Pilot bearing structure should provide sensing of radial stresses, which occur due to magnetic

and mechanical imbalance.

Adjustable bearing bolts should bear stress of open-side magnetic traction between stator and

rotor which is possible during the rotor winding double fault to the earth.

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15.OIL BATHS

Oil bath for thrust bearing and upper pilot bearing should be located in the central part of the

upper bracket. Oil bath should be of a mixed type, in which thrust bearing and bearing part

should be located. Oil bath of the lower pilot bearing should be located in the central part ofthe lower bracket.

The designer has right to offer other type of decision regarding the oil bath and should

provide background for his decision in the Technical offer.

Oil bath dimensions should be specified according to the dimensions of the thrust bearing,

bearing part and the oil-cooler. The structure of the bath should provide correct circulation

and reliable oil-cooling using the self-lubrication principle of thrust bearing and bearing

parts.

Oil-cooler should be located inside the oil bath, and all neceessary pipes out of the bath.

Additionally, after lifting the oil-cooler from the bath, easy access to the thrust bearing and

the bearing part should be provided.

Oil bath should have panel (terminal) system, which should provide access of the hot oilthrough oil-cooler, from where, already cooled, it should pass to the thrust bearing and the

bearing part. Special attention should be paid to the compaction of the oil baths in order to

avoid oil leakage and oil steam outflow from the bathes.

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17. VENTILATION AND COOLING SYSTEM

Generator ventilation and cooling system should be air cooling system with closed cycle self-

ventilation and warm air cooling in the air-to-water-cooling systems (air-coolers).

Necessary flow for provision of the cooling air circulation should be created by the rotor(rotor rim and the poles).

Generator should have sufficient quantity of air coolers, which should be located

symmetrically along the stator frame perimeter.

Structure of air-coolers and their installation location should allow service of the air-cooling

system without their dismounting.

Air-coolers should be made of corrosion-resistant material.

The air-cooler joints should be flanged and each joint should have valves.

Possibility of the generator operation with nominal capacity without one air-cooler should be

foreseen.

The air-coolers should be of such cooling capacity, that in case of air-coolers input water

temperature increase up to 28 o C, at the outcome moment from the air-coolers the watertemperature should not exceed 35 oC.

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18. THERMAL CONTROL

The structure of the generator should consider permanent control of its temperature in order

to protect the generator from possible heat. For this reason thermometers and thermometric

devices should be installed in the generator.The place of their installation and their number should be relevant to GOST 5616-89

standard and IEC 60034 norms.

In order to define stator winding temperature, thermometers should be installed between

upper and lower sides of the bobbin barrels. In order to define stator core temperature,

thermometers should be placed on the face of the slot.

For measuring temperature of thrust and pilot bearings the thermometers should be installed

in the body of the segments.

Oil temperature in oil baths of the thrust bearing and bearing parts should be measured.

For measuring the temperature of cooling air, thermometers should be installed at the input-

output of the air-coolers.

The thermal control system should be automatic, which should allow constant registration ofthe temperature at all controlled locations, signalize regarding the heat of the generator

elements achieving dangerous level and switch the generator off the system in case of

exceeding the allowable temperature at any of the measurable location.

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19. FIRE-FIGHTING EQUIPMENT

For fire localization and extinguishing, modern system of fire-fighting equipment should be

installed on the generator.

Fire extinguisher should consider manual and automatic insertion.Fire extinguishing should be performed by water-spray.

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21. TRANSPORTATION, MAINTENANCE AND INSTALLATION

Transportation will be provided be means of railway transport up to the HPP.

In the Technical offer the designer should submit in detail:

- Means of conservation and packaging generator assembling units. The used materialsshould be moisture-resistant and avoid combustion (fire).- generator assembling units scheme for loading, conditions and transportation methods.- schemes, methods and conditions for generator mounting works at the power station.- program and methods of testing and inspection of the assembling units and whole

generator during mounting works.

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22. TESTING AT THE FACTORY OF ORIGIN

22.1. Input control and relevant testing of all materials, used for manufacturing the generator

should be conducted according to GOST, ASTM norms and the norms of the factory of origin.

22.2. In the process of the stator winding on-shot tests with increased pressure according tonorms of the factory of origin should be conducted.

After manufacturing process is finished stator all bobbin barrels should be tested with increased

pressure equal to 36kV, frequency of 50 hertz during 1 minute. Stator all bobbin barrels should

be tested for dielectric losses with determination of the tg and tg values for rated voltage with

intervals (periods) from 0,2 of nominal tension up to 1,0 of nominal tension with pitches equal to

0,2 of nominal tension. These measurements should be performed according to VDE 0530

norms.

All bobbin barrels should be tested on determination of the partial discharge factor. These tests

should be performed according to the norms of the factory of origin taking into consideration

IEC norm requirements.

Two bobbin barrels should be tested till achieving indirect contact. Tension breakdown voltagevalue should be not less then 44 kV.

After its installation on the pole, four bobbin barrels of the winding excitation should be

endurance tested (Endurance Voltage Test) according to the USA standards IEEE Std 1043-

1996 and IEEE Std 1553-2002.

22.3. After installation on the pole, each ready winding excitation bobbin should be tested with

increased pressure equal to 10-fold nominal excitation tension plus 1000 V. Ready collectors

should be tested with increased pressure equal 10-fold nominal excitation tension plus 3000 V.

Both of these tests are performed with volt alternating current with 50hertz of frequency during

1,0 minutes.

After its installation on the pole, each ready excitation bobbin barrel should be tested for

revelation of inter-winding faults. The tests should be conducted in conditions of the tension

input to the bobbin coil terminals, equal to 3 V for each bobbin, but not more then 200 V.

According to the rotor winding bobbin resistance value to the alternating current should be

determined existence or absence of the inter-winding fault. Deviation of the received results of

the measurements from average measured value should indicate for 3-5% existence of the inter-

winding fault.

22.4. Brake test for resistance and leak resistance, oil-cooler and air-cooler tests for resistance

and leak resistance should be performed during 30 minutes with hydraulic pressure, value of

which should be determined depending on operational pressure according to the norms of the

factory of origin.

22.5. Stator core tests for absence of local heating and for determination of the specific lossesvalue should be performed during dielectric displacement in the stator core back equal to 1,0

tesla with duration of 90 minutes. Tests should be conducted on the ready stator core according

to the norms of the factory of origin.

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23. ON-SITE TESTS

Before starting industrial operation, the generator should be acceptance-tested at the power

station according to the methods, described in the relevant GOST 10169-77, GOST 11828-86

standards and IEC 60034 norms.Acceptance tests should be following:

- measurement of the windings insulation resistance for the body of the generator and thewindings. Resistance should be measured by megohmmeters (meggers) for the tension of

2500V for the stator winding and 1000 V for the rotor winding.

- measurement of the insulation resistance of the temperature indicators. The resistanceshould be measured by megohmmeter for 500V.

- Measurement of the stator and rotor winding resistance in case of the constant current inactually cold condition.

- Measurement of the resistance of temperature indicators in case of constant current inactually cold condition.

- Measurement of the stator windings insulation in relation with the generator body andbetween the windings for the electrical resistance with overvoltage equal to 19, 2 kV of

50 hertz frequency with duration of 1 minute.

- rotor winding insulation test in relation of the generator body for electrical resistance incase of increased tension equal to 8-fold excitation tension of 50hertz frequency with

duration of 1 minute.

- stator inter-winding insulation test for electrical resistance by means of tension increasefor 50% above generator nominal current with duration of 5 minutes.

- specification of the floating current and symmetrical voltage characteristics.- specification of the set-up three-phase short-circuit characteristics.- specification of the losses and efficiency output.- Test for heating.- Test for sudden three-phase short-circuit. The test should be performed on the generator,

operating with excitation floating current, relevant to generator 70% nominal current.

- specification of inductances along the direct and quadrature axis and time constant.- measurement of electrical current between shaft ends.- vibration measurement of bearing parts, stator core and stator winding coils.- insulation resistance measurement of thrust bearing and bearing parts.- temperature measurement for thrust bearing and bearing parts segments, oil temperature

measurement in oil-baths.

- determination of nominal current excitation.-

measurement of the apparent resistivity in case of alternating current of rotor each polein order to reveal inter-winding faults.

- air-coolers and oil-coolers test with increased pressure.- test in case of increased operating speed, achieving by the generator in the moment of

dropping rated load capacity.

- determination of the phase-to-phase (mesh) voltage THD (total harmonic distortion).- generator continuous on-load operation with native-mode excitation during 73 hours.

Note. The generator is considered accepted for industrial operation after successfully passing

the acceptance tests and successful 72 hours on-load operation. Rated load value is specified at

the HPP and should be agreed with the Client.

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24. GENERATOR EXCITATION SYSTEM

24.1. Each generator should be equipped with excitation statical thyristor system with automatic

excitation regulation. the excitation system should be made according the self-excitation

scheme.The set of the excitation system includes:

- thyristor converter with transformer power source;- automatic excitation regulator;- device for excitation manual operation;- device for excitation forcing, deenergization and excitation field suppression;- device for generator rotor protection from overstress and overload;- automatic excitation control equipment;- signaling and damage protection equipment for excitation system;- switchgear for multipoint circuit for provision and taking off power from the exciter;- device and equipment of excitation cooling system;- controlling and measuring equipment.24.2. Excitation system (exciter) should have the following main characteristics:

- Exciter nominal current should be relevant to the generator continuous operation in case of

nominal load, nominal current and nominal capacity factor. At the same moment, the voltage

value should exceed nominal generator excitation current not less then for 10%.

- exciter design current should be relevant exciter nominal current and the generator

excitation design current. Additionally, current value should exceed the generator excitation

design current not less then for 10%.

- maximum excitation final stress (field-forcing ratio) should be note less then 2.0-fold from

the generator excitation design current.

- nominal speed of the rate of excitation voltage rise in the forcing mode should be not less

then 2.0 per unit value per minute.

- exciter should provide excitation stable control in the continuous mode not less then from

20% excitation of generator idle running up to 110% of generator excitation nominal current

during generator mains operation and during idle running mode.

- the exciter should provide continuous operation of the generator in the mode of reactive

power costing , as well as power transmission line charging mode.

- exciter should bear generator excitation 2-fold nominal current in the period of not less then

50 seconds.

- exciter should have an field suppressing equipment for every normal and emergency mode

of generator operation.

24.3. Generator excitation system should be relevant to the requirements of the GOST21558-76 standard and IEC norms.

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25. SCOPE OF THE TECHNICAL OFFER

25.1. Technical offer for the generator should have explanatory memorandum, outline

drawing, foundation drawing, and mounting scheme. Admitted transportation and mounting

weights should be indicated. Values and directions of all forces, passed from the generator tothe base should be indicated in the foundation drawing.

25.2. Explanatory memorandum should include general requirements and characteristics of

the generator, description of the generator structure and its separate connection joints,

description of the excitation system, description of necessary supplementary equipment and a

table (list) of basic data of the generator.

List of the spare parts should be listed with guarantee period for 5 years in the explanation

memorandum.

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REGISTRY OF MODIFICATIONS

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