An indirect adaptive type-2 fuzzy sliding mode PSS design to damp power system oscillations

This paper introduces a new indirect adaptive type-2 fuzzy sliding mode controller as a power system stabilizer (PSS) that used to damp out the low frequency oscillations in power systems. The proposed controller design is based on the integration of sliding mode control (SMC) and Adaptive type-2 fuzzy control. The type-2 fuzzy logic system is used to approximate the unknown system function and PI control term is used to eliminate chattering action in the design of sliding mode control. Using Lyapunov stability theory, the adaptation laws are developed to make the controller adaptive to take care of the changes due to the different operating conditions occurring in the power system and guarantees stability converge. The robustness of the proposed stabilizer has been tested on a single machine infinite bus model. Nonlinear simulation studies show the better performance of the proposed stabilizer and confirm the superiority over adaptive type-2 fuzzy synergetic (AFSPSS), adaptive type-2 fuzzy (AFPSS) and the conventional (CPSS) stabilizers.