Design of Volts per Hertz Limiter with consideration of the Under-Excitation Limiter control actions

The dynamical relationship between the Volts per Hertz Limiter and the Unde r-Excitation Limiter control loops in a synchronous generator is examined u sing the frequency response technique, From the analysis, it is concluded t hat sustained oscillations due to the interaction between the two limiters can occur should the loading level of the generator exceeds a certain thres hold value. For generator operation below this value, a systematic design p rocedure has been proposed for the limiters which will ensure network stabi lity.