Application of TCSC Power Oscillation Damping controller to enhance power system dynamic performance

Abstract

The effectiveness of a Thyristor Controlled Series Capacitor Power Oscillation Damping controller (TCSC PODC) in enhancing the power system dynamic performance of a fundamental power system model is explored in this paper. Controller parameters are optimally tuned using Genetic Algorithm (GA) to achieve better dynamic performance. A multi-objective problem is formulated to optimize a composite set of objective functions comprising damping factor and damping ratio of critical eigenvalues in and around the Hopf bifurcation point. The generator and its excitation control dynamics are modelled by four first-order differential equations. It is shown that when excitation control gains are set high and when the excitation hard-limits are taken into account, the fundamental power system model undergoes global bifurcations including period-doubling cascades, which lead to sustained chaotic behaviour. The route of cascading period-doubling bifurcation (PDB) is deeply studied and PDB route to chaos is presented. The existence of the chaos, also called strange attractor, is confirmed by time domain plots and phase plots. The simulation results show that the GA tuned TCSC PODC is effective in mitigating the chaotic electromechanical oscillations and hence effective in enhancing the power system dynamic performance.