Improved Design of Interval Type-2 Fuzzy based Wide Area Power System Stabilizer for Inter-area Oscillation Damping

Abstract

The interconnection of power system due to the ever-time increase in power demand has caused inter-area oscillations as a challenge to power system stability. The present paper proposes the novel design of an Interval Type-2 Fuzzy based Wide Area Power System Stabilizer to damp the inter-area mode of oscillations for improving the power system stability. The usage of Wide Area Measurement Systems for continuous monitoring of the power grid plays a significant role in maintaining the stability of the power grid. The proposed controller uses wide-area signals from WAMS as the input signals. The controllability index calculation performs the selection of the most affected wide-area signals. The participation factor is used to identify the location of the controller. Sliding Surface approach is introduced in the controller to upgrade the performance of the controller during different operating conditions. The sliding surface approach has made the system insensitive to the parameter variations. The interval type-2 fuzzy control is a model-free approach with better control performance, due to its higher degree of freedom of interval type-2 fuzzy sets. Finally, the optimal tuning of sliding surface parameters has been considered as an optimization problem with the minimization of Integral Time Square Error using Real Coded Genetic Algorithm to enhance the damping control. The proposed Fuzzy controller has been tested in two area, four machine, 11 bus IEEE benchmark system. From the simulation responses and the comparison with different controllers, the proposed controller shows robustness and effectiveness with more accurate dynamic response and better damping of inter-area oscillations under different system operating conditions and load perturbations.