Generator short circuit current calculation

[pbeigbeder]

Hello
For a project, I need to calculate short-circuit current calculation following IEC60909 rules.
The question is:
The generator is rated 45MVA and I have the characteristics for 45MVA. The power plant where the generator will be used is dedicated to 42MVA (active power / power factor) and I can calculate the reactance from 45 to 42.
But in my mind, for the calculation of the short-circuit current I must used the rated generator characteristics and particulary 45MVA (in the short-circuit calculation software).
Does anyone know what says the IEC 60909.
Thanks

 

[Marmite]

My view is that you should use the manufacturers data for the machine. Excitation Control system action will not affect the peak asymmetrical short circuit current but may affect the short circuit breaking current depending on the fault clearance time.
Regards
Marmite

 

[dpc]

The generator does not care about IEC standards or how you operate the plant, so you need to use the generator's actual MVA rating.

 

[rcw retired EE]

Use the generator rating, not the rating of the combined generator/prime mover. The initial short circuit current will be the same whether the generator is being drivn by a 45 MW turbine, a 1 MW diesel engine or is running as a synchronous condensor without a prime mover connected.

 

[davidbeach]

I will also concur with the above responses; the machine is the machine and as long as it is spinning at synchronous speed it will have the published characteristics.

 

[pbeigbeder]

Thanks a lot for your answers. They confirm my mind.
Regards.
PB