Restrike Modeling of Vacuum Circuit Breaker switching off Shunt Capacitor Banks with EMTP

摘要

The shunt power capacitors are used as a reactive compensator while vacuum circuit breakers are used to switch shunt capacitors in power grid. To research the high over-voltage during switching off the shunt capacitors and a vacuum circuit beaker restriked, the restriking model is built with three-phase vacuum circuit breakers, considering the capacitors' energy storage characteristic and asynchronous operating. The over-voltage is harmful to the insulation and life-circle of the equipments and even threatens power system safe and stabile operation. The variation trends of both recovery voltage between the contacts and the capacitors voltage are theoretically deduced. The model based on a 220kV substation of Guangdong grid was built and the most serious case that breakers are restriked in two phases are numbered with EMTP. Compared with theoretical results, simulation results are valid and practical.