Closed Loop Load Response to Random Perturbations

Various studies to determine the response of power system loads to voltage and frequency fluctuations, have generally neglected the feed back from the load to the generation side as well as the dynamics. These effects become very significant when the fluctuation originating from the load side is of the same order as those from the generation side. The effect may be negligible if large perturbations are staged to determine the response. However, methods based on small variations should take into account the fact that the variations in the load itself may lead to a bias in the model parameters due to feed back. This paper formulates a theory for the simultaneous generation of noise from both the load and generator sides and proposes a method for determining all the coefficients. The method described is being implemented on-line on a mini/ micro computer based system.