What is the base value for the generator GREF?
From PSSE's POM manual, it says that the GREF value is a pu value whose base is the turbine rate MW, and if that is not specified by the governor, then its base is the machine MVA (MBASE).
However, when i look at the GREF values, they seem to be very small initially, generally somewhere between 0.03-0.05, where as the PMECH is close to 1 pu, even though both are on MBASE. Also, i tried changing the GREF by 1% and it resulted in 20% change in the power output (with respect to the MBASE). The governor in question is a TGOV1, which doesnt have a TRATE value.
Obviously I am missing something here, and my experiments say the GREF is not on MBASE. Any clarification on this mystery would be appreciated.