Design of electric power system stabilizer based on fuzzy control theory

The authors present a method of constructing simple fuzzy control rules for controllers of electric power systems, by simplifying variables of condition parts and rules and minimizing the number of membership functions. The simplification is caused by a coordinate transformation with the rotation angle θ on the phase plane. An electric power system with controllers is modeled as a fuzzy model which is composed of a weighted average of linear systems. Based on the fuzzy model, stability analysis of the fuzzy control system is discussed. For optimal parameters setting, a quadratic performance index is considered and the quasi-Newton method is applied. The control effect was demonstrated by an application to a one-machine infinite-bus power system with an automatic voltage regulator and a governor as controllers