Operation of Thyristor Controlled Reactor and Thyristor Switched Capacitor of Static var Compensator for Voltage Variations

Abstract

The deviations that occur in electrical power supplied by utilities to consumers are termed as power quality disturbances. Due to power quality disturbances, a change is evident for a short duration in voltage, current or frequency. In order to maintain constant voltage to the connected load, compensation devices are used based on flexible AC transmission systems (FACTS) technology. Based on an increase or decrease in voltage, suitable correction action can be taken by power electronic based devices. The voltage and current variations of static VAR compensator, shunt connected flexible AC transmission system device, is analyzed. The variations in system voltage are due to sag and swell. The operation of thyristor-controlled reactor (TCR) and thyristor switched capacitor (TSC) are analyzed which together comprise static VAR compensator.