Transients caused by switching of 420 kV three-phase variable shunt reactor

• Transients caused by switching of three-phase 420 kV variable shunt reactor (VSR).
• Model in EMTP-RV software with dynamic electric arc in SF6 circuit breaker.
• Inrush currents due to VSR energization and overvoltages due to de-energization.
• Overvoltages due to electric arc reignition.
• Mitigation measures and operating switching strategy of VSR were proposed.

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 the EMTP-RV software. It includes a 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.