The document compares the differences between 200MW and 500MW power generators and their electrical auxiliaries. Some key differences include: the seal oil system having single or double pumps and using clarified or ECW cooling in 200MW units versus 2/2+1+1 configuration in 500MW units; generator gas coolers and temperature control varying; stator water and potential transformer systems having different cooling and temperature/conductivity control arrangements; excitation systems with different cooling designs; and emergency bus schemes utilizing diesel generator sets or interunit ties differently between the two sizes.

1. A PPT ON
DIFFERENCE BETWEEN
200 AND 500 MW
GEN AND ELECTRICAL AUXILLARIES

2. AREAS COVERED
1. Seal oil system.
2. Generator gas system.
3.Excitation system.
4. Stator / PW system.
5. Control system.
1. Unit Bus
2. Station buses
3. Emergency Bus

3. SEAL OIL SYSTEM
 Seal oil circuit.
 seal oil p/p.
 Cooling medium.
 Dp RV arrangement
 Single / double
 2 / 2+1+1
 Clarified / ECW.

6. GENERATOR GAS SYSTEM
 Cooler arrangement
 Gas temp control
 Cooling water type.

10. STATOR WATER PW SYSTEM
 Scheme
 Water Cooling arrnagment
 Temp control
 Conductivity control.
 Other arrangement.
 Make up arrangement.

13. EXCITATION SYSTEM
 Excitation arrangement.
 Cooling arrangement.

16. BRUSHLESS EXCITER

19. EMERGENCY BUS
 Scheme
 Difference
 DG set
 Interunit tie

20. STATION BUS ARANGEMENT
 Station trf.
 Station buses
 Tie to unit buses
 Inter unit tie