Design of Thyristor Controlled Series Compensator with Desired Eigen-values in the Sliding Mode

Abstract

This paper presents an output feedback-based Variable Structure Controller (VSC) designed for a Thyristor Controlled Series Compensator (TCSC), a Flexible AC Transmission System (FACTS) device, to augment the dynamic stability in Electric Power System (EPS).  To design the switching surface, the speed deviation, serving as the feedback signal, is connected to the input of the VSC. The objective is to evaluate the effectiveness of the TCSC with VSC in improving stability in a Single Machine Infinite Bus (SMIB) system. The system’s dynamic stability is analyzed using eigenvalues and nonlinear time-domain simulations at nominal load conditions. The proposed VSC-based TCSC is compared to TCSC with Feedback control, Power System Stabilizer (PSS) control, and a system without control. Results show that the proposed variable structure feedback-based TCSC controller significantly improves dynamic stability compared to TCSC and PSS control.