A NEW METHOD OF EXCITATION CONTROL-BASED ON FUZZY SET-THEORY

The synthesis of the structure of the PSS and its parametrization are based entirely on methods of linear system theory. Thus the desired ef fect of the PSS is limited to a bounded area around one system operati ng point. The use of a controller based on fuzzy set theory introduces an event controlled excitation of the synchronous machine taking into account the power system operation. The desired response of the fuzzy controller is given by a set of rules which are obtained from the lim its of the voltage regulator and the undesired performance of the conv entional excitation control. A fuzzy controller has been developed for which simulation results are provided. These results support the conc ept of a fuzzy controller for the purpose of excitation control. They show that a well designed fuzzy controller is superior to a fast excit ation control with an additional PSS.