synchronize parallel generator

[wimbohryo]

Dear experts

I want to configure new alternative power for electrical power system. You can look the system in image attachment.
this picture:

The condition is GTG and STG2 synchronize with system integration 33kV.
I want to ask about the synchronize fedeer to feeder in breaker point A. Is the system eligible for synchronous?
. Or any additional prosedure for synchronous breaker point A.

Please help me to give some explanation. Any comments is really appreciated. Thank you.

Best Regards,

 

[ScottyUK]

If the 33/11kV transformers are both in service then your generators are already synchronised. You might want a check-sync relay at Point A in case one machine is more heavily loaded than the other and pulls its 11kV bus ahead in phase of the more lightly loaded machine. It is possible to get large circulating currents by paralleling at both the 33kV and 11kV levels.

 

[wimbohryo]

Hi scottyUK
thank you for reply

In this case i want to transfer the power flow from GTG to STG 2 without power off at the load. Is possible if i configure this system with synchronize at breaker point A? or any procedure to transfer the load with switch off the syncronize of GTG/STG2 or 33/11 kV transformers.
Any comments is really appreciated. Thank you.

Best Regards,

 

[sandeepelect1]

Hi, wimbohryo,

as i could understand that you want to shift load from GTG to STG2.

i want to know that,

are you thinking of Switchoff the GTG during low load hours?

Regards,

 

[wimbohryo]

Hi sandeeoelect1

Shift load from GTG to STG2 because a maintenance schedule for bus 11kV and GTG. Bus 11kV at GTG must be power off but keep the load still power on.

Regards,

 

[waross]

Shift the power by reducing the steam flow or the fuel feed to one of the generators. When the load one one generator is close to zero, disconnect the generator.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[wimbohryo]

For shift the power for Load sharing is no problem.
But possibility to synchronize breaker point A that condition is both GTG & STG already synchrone with integration system 33kV.
It's possible? specifically in phase angle fedeer to feeder breaker point A. thanks

 

[ScottyUK]

Yes, it is possible if the generators are both synchronised to the 33kV bus. You may have to move load between machines to match the phase angle within acceptable limits. If one generator is heavily loaded and the other is idling then you'll probably have difficulties. Without doing some load flow analysis you won't be able to guess the conditions which will allow acceptable conditions for breaker closure.