The influence of a vacuum circuit breaker and circuit parameters on switching overvoltages generated during interruption of starting motors

摘要

A computer program has been developed for simulating the voltage escalation (VE) when a vacuum circuit breaker (VCB) interrupts the starting of a motor. The influences of the vacuum circuit breaker's high frequency (HF) interrupting capability, dielectric strength rise, cable length and also motor power, has been traced in order to produce a sort of general view of the overvoltage phenomena in actual networks. It has been discovered that HF interrupting capability is important for high-power motors connected by short cables to the VCB when B-termination of VE predominates. In the majority of practical cases, overvoltage protection is recommended for both conventional and low-surge contact materials.