Theoretical analysis of mechanical characteristics of vacuum circuit breaker with spring operating mechanism

In this paper, mechanical characteristics of spring operating mechanism of vacuum circuit breaker are calculated theoretically and the normal opening speed curve is obtained when spring mechanism is operated under unload condition. The calculated results have good coincidence with the real testing results. And at the same time, the fault opening speed curves are also calculated assuming that some components of the spring operating mechanism are in fault conditions. The calculated results are valuable for the circuit breaker´s on-line monitoring, fault diagnosis and condition maintenance.