Implementation of hybrid fuzzy sliding mode controller for power system stability

Abstract

This paper proposes the improvement in the operation of power system stabilizer (PSS) using a combination of sliding mode control(SMC) and fuzzy logic. The objective is to enhance the small signal stability of the power system by effectively damping the low frequency oscillations and thereby increase the power transfer capability. The conventional PSS results in the poor performance at different operating points and uncertainties. Using sliding mode control a robust controller is designed to enhance the stability, however, at large disturbance a large switching gain is required which produces chattering problem. Fuzzy logic is employed to compensate for the chattering and overall improve the performance of SMC based PSS. The small signal stability of the system is analyzed by carrying out the simulation using the proposed controller and a comparison is drawn with the Conventional Power System Stabilizer (CPSS) performance. The simulation results show improved performance in terms of reduced overshoot, quick settling time and effective damping of oscillations.