BHEL Haridwar

Electrical Machine Engineering 1

- Rakesh Kumar

BHEL Haridwar

Electrical Machine Engineering 2

125/67

800

Capability of Generator Modules

115/67

93/38 108/39 108/44

108/55108/44 (VPI)

250

115/52

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Electrical Machine Engineering 3

1. Generator Module – THRI 108/44

270 MW Turbo Generator

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2. Operating Parameters Parameters 250 MW 270 MWRated Voltage 16.5 KV 16.5 KVStator Current (Amps) 10291 11115Rotor Current (Amps) 2497 2666Rotor Voltage (V) 299 325SCR 0.63 0.58Hydrogen Pressure (bar) 4 4Heat Load (KW) 2650 2900Stator Wdg Temp (°C) 93 98Rotor wdg Temp (°C) 81 84.5Core temp (°C) 65 67

270 MW Turbo Generator

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Electrical Machine Engineering 5

END SHIELD

OPENING FOR

COOLERS

STATOR CASING

Design Constraints & Solution (270 MW)

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Electrical Machine Engineering 6

Design Constraints & Solution (270 MW)

ORIGINAL CONTOUR

NEW CONTOUR

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• Stator Winding Bars with 540° Transposition & 2-Plane Bending: THRI designs so far manufactured by BHEL are with 360°/single plane transposition. Adoption of 540° transposition leads to manufacturing simplicity as strip to strip brazing is eliminated.

Design Features (270 MW)

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Electrical Machine Engineering 8

540° Transposition of wdg conductors (270 MW)

540 Deg Transposition

Strip to strip brazing is eliminated.

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Cooler Parameters - Parameters 250 MW 270 MWInlet Water temp (°C) 38 38Cold gas temp (°C) 45 43Cooling Water Flow m3/hr 280 350

Special Features –1. Special fin configuration has been developed.2. Pitching has been reduced and manufacturing shall be

done in close tolerances. 3. Cold gas temperature achieved shall be below normal

requirement.

More Efficient Coolers (270 MW)

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Electrical Machine Engineering 10

1. 540° transposition of winding conductors 2. Elimination of strip to strip brazing leading to manufacturing

time cycle reduction3. Strengthening of stator winding overhang4. Total VPI core and stator windings5. More efficient twin Hydrogen coolers6. Increase in transportation weight – 3 Tons (approx)

Design Features (270 MW)

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Electrical Machine Engineering 11

525 MW TURBO GENERATOR

PW TankWater Cooled Stator Winding

Compressor(on TE only)

End Shield Mounted Bearings

Terminal Bushings

Rotor

Stator Core

Module – THDF 115/59

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Electrical Machine Engineering 12

1. Generator Module – THDF 115/592. Operating Parameters Parameters 500 MW 525 MWRated Voltage 21 KV 21 KVStator Current (Amps) 16291 16981Rotor Current (Amps) 4040 4213Rotor Voltage (V) 340 355SCR 0.52 0. 49Heat Load (KW, H2 Coolers) 4639 4963

Hydrogen Pressure (gauge) 3.5 4.0Primary Water Flow(m3/hr) 65 75Shaft Seal System Double Flow Single Flow

525 MW TURBO GENERATOR

BHEL Haridwar

Electrical Machine Engineering 13

600 MW Generator

Module – THDF 115/67

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Electrical Machine Engineering 14

Better ratio of overall core length to effective core length

Axial Cooling of Stator Core

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Electrical Machine Engineering 15

Axial Cooling of Stator Core

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Electrical Machine Engineering 16

500 MW - FIVE STAGES 600 MW - THREE STAGES

• Less resistance for Stator Core cooling and optimised rotor, less pressure across compressor • Reduced compressor losses and hence higher efficiency

Optimisation of Compressor Stages

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Core Insertion into Stator

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Cooler Housing Frame houses vertical coolers and End Shield houses bearings , shaft seals etc.

Easier to handle and assemble at works/site.

TE End Shield in two parts

Cooler Housing Frame

End Shield

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Electrical Machine Engineering 19

500 MW 600 MW

DOUBLE INDENT WEDGE

TRAPEZOIDAL SLOT SHAPE

SINGLE INDENT WEDGE - SIMPLIFICATION

PARALLEL SLOT - VARIETY REDUCTION

Rotor Slot & Wedge

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Electrical Machine Engineering 20

500 MW - NINE SHAPES 600 MW - SHAPE SLOT

600 MW - SHAPE OVERHANG

Increased cooling duct size in 600 MW design Provides better cooling

Rotor Cooling Duct

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Electrical Machine Engineering 21

Replaces earlier Circular coils with Simple design.Resulting in time Cycle reduction.

Rectangular Rotor End Winding

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Electrical Machine Engineering 22

• Single flow Ring Type Shaft Seals • Simple construction and easy O & M

SINGLE FLOW - 600 MW DOUBLE FLOW - 500 MW

Seal Oil System

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Electrical Machine Engineering 23

Parameter Unit 600 MW 500 MW Rated Voltage kV 21 21 Rated Current Amp 19407 16166 Hyd. Press. (g) Bar 5 3.5

P.F. - 0.85 0.85 Transportation

LxW mm 9875x3880 8830x4100

Stator Transportation

Weight

T 316 265

Technical Parameters

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Electrical Machine Engineering 24

Paiton Phase II, Unit 5 Indonesia 1999

Paiton Phase II, Unit 6 Indonesia 1999

Hanfeng Unit 1 China 2000

Hanfeng Unit 2 China 2001

Iskenderun Unit 1 Turkey 2003

Iskenderun Unit 2 Turkey 2003

Collaborator’s Experience

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Electrical Machine Engineering 25

THANK YOU

END