Short Circuit calculations with site rated gas turbines
Short Circuit calculations with site rated gas turbines
(OP)
I am working with a gas turbine gen set and I have some questions regarding Short Circuit calculations and Short Circuit power.
The turbine has a site rating of about 12,5 MW (15,6 MVA) and a ISO rating of about 15 MW (18,5 MVA) power factor of 0.8. The alternator is rated 18,5 MVA.
So when I calculate the SC rating I use the alternator name plate rating of 18,5MVA.
My question is, will you always get maximum SC current independent of the turbine output? Or do I have to have ideal circumstances where the turbine gives the needed mechanical power?
If the current is dependent on the mechanical power from the turbine, can you detail?
The turbine has a site rating of about 12,5 MW (15,6 MVA) and a ISO rating of about 15 MW (18,5 MVA) power factor of 0.8. The alternator is rated 18,5 MVA.
So when I calculate the SC rating I use the alternator name plate rating of 18,5MVA.
My question is, will you always get maximum SC current independent of the turbine output? Or do I have to have ideal circumstances where the turbine gives the needed mechanical power?
If the current is dependent on the mechanical power from the turbine, can you detail?






RE: Short Circuit calculations with site rated gas turbines
Power equals current times voltage times power factor.
In the event of a short circuit the voltage may be very low so the power or MW requirements are lowered.
The short circuit current is very reactive so although there are a lot of KVAs, when that is multiplied by the low power factor resulting from the reactive current the KW or MW demands are lowered.
I would use the alternator rating for short circuit calcs.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Short Circuit calculations with site rated gas turbines
----------------------------------
If we learn from our mistakes I'm getting a great education!