OPTIMAL BASED ROBUST FUZZY PARAMETRIC UNCERTAIN CONTROLLER DESIGN FOR A SMIB POWER SYSTEM STABILIZER

This paper addresses the problem of determining an optimal LQR design for a robust power system stabilizer (PSS). For achieving optimal PSS design, first, the different loads of a PSS are described using fuzzy alpha-cut numbers, and a fuzzy parametric uncertain system is formulated into an interval state-space controllable canonical form system. Second, the maximum uncertainty interval of the system is translated into the weighting matrix Q of the LQR problem to guarantee that the designed optimal controller is robust under worst-case conditions. The designed PSS is applied to a single machine infinite bus (SMIB) system operating under various loading conditions. The simulation results showed that the performance indexes of proposed method are superior to those of typical Phase Lead based method.