HV Transformers and Primary Sides

" ... 132 kv side breaker is closed on dead bus ... "

Do you mean open circuit (no load)?

YES

"at the time of energising transformer the out put of engine is about 1 MW" - what are the 1 MW loads. Does the generator supplying load through other transformer?

I wouldn't answer it by simply "YES". There are few things to consider:

1. If the transmission line is too long, then the generator can experience a high capacitive load of leading power factor and it may cause the generator voltage regulation system unstable. Synchronous generators are unstable while supplying leading power factor loads. In your case, the generator seems supplying 1 MW load. If resultant power factor of the current 1 MW load and the transmission line capacitive load is lagging (I am guessing so), then it should be OK.

2. Before energizing the transformer, make sure there is appropriate protection enabled for the generator, transformer and 132 KV transmission line.

3. This is not a suggested method. For safe operation, energize the transformer first (keeping the 132 KV side breaker open), then close the 132 KV breaker. However, it doesn't prevent you to do the way you described.

-MS

There may not be a problem of charging the transformer. But assuming you are on a grid, how do you synchronise when later the HV breaker is closed?

When you don't have load on the generator why do you want to run it at all ? it will just feed the no load current of the transformer. DGs are quick start so when the load is available, start it.

This sounds like a scary scenario to me.

Regardless of is it possible, I would think that is Must Not be done for safety reasons.

Transformers are not generally direction sensitive, just step-up or step-down.

If the Primary side breaker is closed you would be backfeeding to the grid, which is putting the unsuspecting lines workers at risk as the line they thought was dead is now live.

Also if the circuit becomes live from the supply end and the generator and mains are out of sync...Well then it is really all about the Boom cause something is goning to give.

I would have thought that the breakers on the Main Switch Board for the incoming Mains and the Generator would be Mechanically interlocked to ensure that they can not both be closed at the same time.

Regards,
Sapper

Actually I am talking about back feeding .when utility company asked me at the time of city black out to supply back feed at least on important feeder whose load is less then the generator out put.