Abstract:
Under excitation limiter is one of the standard auxiliary control devices in synchronous
generators that it has been widely used since the advent of the automatic voltage
regulator (AVR) for excitation control. Under-Excitation limiter usually used to prevent
generators for going out the steady-state stability limited. The survey on power swing
and rotor angle stability has accomplished in Shaheed Rajaee power station which is one
of the biggest power plants with four units of 312.5 MVA in Iran.
In this paper, the 1st and 3rd order system model are designed and compared together.
UEL can cause generator instability if this setting is inappropriate.
Show using the 1st order system model for designing the UEL can only be used when
the PSS is activate and the absence of the PSS. However, it may cause to be instability
and will be much better performance if the 3rd order model with PSS uses for designing
of the UEL.