A Fast Algorithm for Mode Switching of TCSC in Less Than a Half Cycle

Abstract

Fast mode switching from capacitive to inductive and vice versa has very important rule in transient stability and fault clearance critical time reduction but it has been considered rarely. Thyristor Controlled Series Capacitor (TCSC) as series compensator of transmission lines in capacitive mode has important rule in increasing loadability, loss reduction and stability improvement of the power systems. TCSC can be also used in inductive mode for increasing impedance of transmission line and fault current reduction. Unfortunately, TCSC is usually used in capacitive mode only. In this paper, a new and fast algorithm is proposed for mode switching of TCSC from capacitive to inductive and vice versa that it changes operation mode of TCSC in less than half cycle. The simulation results show that this method has more speed than conventional methods which they have more than three half cycle delay. The proposed method is very effective in improving of stability, special in transient stability, increasing time response of TCSC and fault current reduction.