Transient Stability Enhancement and Power Oscillation Damping in a SMIB System using a Dual Lead-Lag Controlled TCSC.

Abstract

This paper investigates the transient stability enhancement in a Single Machine Infinite Bus (SMIB) system using a Thyristor Controlled Series Capacitor (TCSC) with a dual lead-lag Power Oscillation Damping (POD) controller. The dynamic model of the SMIB system was subjected to a three-phase fault disturbance. Three operating conditions were considered: without TCSC, with fixed TCSC compensation, and with TCSC and a dual lead-lag POD controller. The controller was designed to improve damping of electromechanical oscillations through phase compensation and gain tuning. The simulations were carried out in a Python-based environment using the SciPy and NumPy libraries. The system dynamics were solved using the solve_ivp numerical integrator with a Runge-Kutta (RK45) method and plots were generated using Matplotlib. The results show that fixed TCSC compensation improves synchronizing performance but does not adequately damp oscillations, whereas the proposed dual lead–lag POD controller reduces peak speed deviation, lowers overshoot, and restores stable operation with a settling time of about 4.2 s.