Synchronized generator with different nominal voltage

[eskim]

Hi All,

Our existing generators are 11,000 V +/-5% output voltage. We set AVR 3% above nominal volt (11,350). Gens are running with voltage control set.

What do you think If a new gen 10,500 V +/-5% will be synchronized with existing system. It should run 8% over its nom volt.

Regards,
Sumadi

 

[Skogsgurra]

If it doesn't trip, it will consume massive reactive power. Is the +5 % of the 10.5 kV machine an absolute limit?

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[ScottyUK]

I expect that you will be running on or above the V/Hz limit for continuous operation. If you aren't then the reactive capability of the machine will be severely limited if you push the terminal voltage up to 11kV. You will probably find that discharge activity is higher at 11kV than at 10.5kV.


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If we learn from our mistakes I'm getting a great education!

 

[Denan]

Can't you adjust AVR of 10,5kV generator to 11kV? The machines we use have same stator winding for either 10, 10,5 or 11kV.
I don't know if your generator can do that, but check with generator manufactor.

 

[TheBlacksmith]

I'm thinking massive circulating (reactive) current, potential AVR instability and maybe a little partial discharge.