Perturbation and Observer Based Sliding-Mode Controller for Excitation control in Single-Machine Infinite Bus System

The objective of this paper is to study and analyze operation of Perturbation and Observer-based Sliding-Mode control (POSMC) to enhance the power system stability instead of conventional Power system stabilizer (PSS). Conventional PSS are based on linearized models which might inherent linearization errors hence non linear controllers are chosen to replicate more practical power system dynamics. The rotor angle deviation together with perturbation are estimated through sliding-mode state and perturbation observer (SMSPO). The estimated signal is fed to the POSMC to generate a control signal which is applied to the AVR to regulate the voltage. The attractiveness of the sliding surface is analyzed theoretically in the perspective of the Lyapunov criterion. The presented POSMC enhances the system performance of the single-machine power system compared to conventional PID controller. Heffron-Phillips model of the synchronous generator is considered in this study.