Comparison of transient phenomena when switching shunt reactors on the line´s two terminals and station busbar

This paper investigates the transient phenomena when switching high voltage shunt reactors on the operation of Tai-power system. Two cases that shunt reactors were installed respectively at 345 kV line´s two terminals and 161 kV station busbar were studied and compared. When shunt reactor was closing, high unsymmetrical currents could be occurred with long time constant; when shunt reactor was opening, reignition between the circuit breaker contact gaps could lead to very steep over-voltages. This study has been carried out by the simulation calculation using the software ATP/EMTP, the results related to the causes of high transient over-voltages that are produced when switching high voltage shunt reactors were presented and the differences between directly grounded and ungrounded reactors were pointed out.