Transients Caused by Switching of 420 kV Three- Phase Variable Shunt Reactor

This paper describes transients caused by uncontrolled and controlled switching of three- phase 420 kV variable shunt reactor (VSR). The model for the analysis of the transients caused by switching of VSR was developed in EMTP-RV software which includes dynamic electric arc in SF6 circuit breaker and the model of substation equipment. Inrush currents due to VSR energization and overvoltages due to de- energization were determined at tap positions corresponding to lowest 80 MVAr and highest 150 MVAr reactive power. Based on the calculation results, mitigation measures and operating switching strategy of VSR were proposed.