THE MATHEMATICAL MODEL FOR DESCRIBING TRANSIENT CHARACTERISTICS OF TCSC BASED ON CAPACITOR VOLTAGE SYNCHRONIZATION MODE

When the capacitor voltage is taken as synch ronizing signal, there is obvious overshoot and oscillations in Thyristor Controlled Series Compensation(TCSC) transients. However, the mechanism for this phenomenon is not explained in existing literatures yet. By the Topology method , this paper chooses conduction angle of thyristors as the object function and builds a two order difference equation mathematical model describing TCSC transient behaviors under capacitor voltage synchronization mode. Based on the derived model, the factors affecting TCSC transient characteristics are discussed. Also the transient mechanism of TCSC is revealed under capacitor voltage synchronization mode.The model is verified by digital simulation results.