Thyristor Controlled Series Compensator

Thyristor controlled series compensator (TCSC) controller, the first generation of flexible AC transmission system (FACTs), can control the line impedance through the introduction of a thyristor-controlled capacitor in series with the transmission line. TCSC is used as series compensator in transmission system. The TCSC controller can be designed to control the power flow, to increase the transfer limits or to improve the transient stability. The TCSC controller can provide a very fast action to increase the synchronization power through quick changing of the equivalent capacitive reactance to the full compensation in the first few cycles after a fault, hence subsequent oscillations are damped. TCSC controller provides variable impedance, which is required for the compensation. The presented controller is suitable only in capacitive zone. For the transition from a capacitive vernier mode to bypass mode the TCSC controller can be modeled with detailed dynamics. The TCSC controller is modeled in MATLAB SIMULINK and can be used in power systems for stability improvement.