Control of shunt reactor inrush currents in the Hellenic-Interconnected Power System

Transients caused by shunt reactor switching have been an important parameter in the design of the relevant equipment (reactor, circuit breaker, insulation) of the Hellenic-Interconnected Power System. Next to the well-known damaging overvoltages produced by shunt reactor de-energization, high dc components of inrush currents with low damping factor have been observed during energization, resulting in excessive electromagnetic stresses to the windings and undesired activation of zero-sequence current relays. In the present study, inrush currents produced by shunt reactor energization are analyzed and the performance of the techniques used for their limitation is investigated.