Voltage stability modelling and real-time monitoring using expert system for operation assistance

This paper describes a prototype expert system to determine a viable power system voltage stability control scheme. A new model for generator buses reaching their limits of reactive power output is presented. This expert system is designed to assist the power system operator in taking the most appropriate VAr control action in a timely fashion. Sensitivity of a fast voltage stability indicator is used to correct power system voltage stability limit violations. Results of tests conducted on the AEP57 bus and 118 bus IEEE test systems, are presented and discussed.