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GENERATOR REWINDING

SOLUTION STORIES

Eraring TPP Stator/Rotor Rewinding (Australia)

1. Summary2. Detailed Scope of Work3. Field Work

DOOSAN POWER SERVICESSOLUTION STORIES ERARING TPP STATOR/ROTOR REWINDING (AUSTRALIA)

1. Summary

PROJECT OVERVIEW

PLANT LOCATION

PJT title Eraring Unit 1-4 Plant R&M Client Eraring EnergyContract year 2007PJT period Total 26 months / UnitInstallation period 5 months / Unit (Installation/Commissioning)

Eraring, Australia

Plant Information

∙ OEM ∙ Capacity∙ COD∙ Cooling Type∙ Stator Winding

GEN: Toshiba 660MW x 4 Units / 50Hz / 23kV / 60 psig1984-1986Water/Hydrogen cooled type2 circuits / 42 slots

∙ Performance upgrade (Output, Efficiency)∙ Lifetime extension∙ Cyclic operation (Flexibility)

Customer Needs

∙ Rewinding of the generator stator and rotor - Rewinding of the stator bar - Re-insulation of the rotor - Replacement of the high voltage bushing, current transformer,

packing gland and flexible lead connection

∙ Capacity increase - Existing 776MVA (660MW P.F 0.85) - Uprating 833MVA (750MW P.F 0.9) approx. 7.3% ↑∙ Lifetime extension: 20 years or more

Scope of Supply

Customer Benefits

2. Detailed Scope of Work

DOOSAN POWER SERVICESSOLUTION STORIES ERARING TPP STATOR/ROTOR REWINDING (AUSTRALIA)

1) Existing Problems

2) Detailed Work Scope

• Stator end vibration problem

• Damage to air release piper on water box

• Stator winding insulation breakdown

• Stator bar end crack on sub-conductor

• Old type design - Leakage of water box,

cooling water passage

• Complete rewinding of the stator - Stator bar & water header pipe - Visual inspections & electrical test

• Re-insulation of the rotor - Rotor insulation replacement &

electrical test - High speed balancing test

• Modification of the terminal box - High voltage bushing - Current transformer - Flexible lead connection

• Performance test

Generator Stator Generator Rotor

Work Scope

DOOSAN POWER SERVICESSOLUTION STORIES ERARING TPP STATOR/ROTOR REWINDING (AUSTRALIA)

3. Field Work1) Removal of Retaining Ring 2) Removal of Field Coils 3) Cleaning of Field Coil 4) Rotor Shaft NDT

5) Coil Assembly 6) End Winding Block Assembly

7) Retaining Ring Assembly 8) Final Electrical Test