Research on Shunt Characteristics of Multi-Break Parallel Connection Vacuum Circuit Breakers

Large-capacity pumped storage power plants have very high requirements on the breaking capacity of generator outlet circuit breakers. Limited by the existing arc extinguishing technology and contact material technology, the multi-break parallel vacuum interrupter structure is the only way to improve the rated through-current and breaking capacity of the vacuum circuit breaker(VCB). Due to the existence of mutual inductance and stray inductance, which makes the multi-break parallel VCBs has the problem of static current unevenness. This paper models the VCB to investigate the effect of different parallel vacuum interrupter structures on the static shunt characteristics of the multi-break parallel VCBs. The results indicate that the completely symmetrical structure is the most ideal parallel structure for multi-break parallel VCBs with three or more vacuum interrupters; Secondly. due to the randomness of the arc and the asynchrony of the vacuum interrupter opening and breaking, the relationship between each parameter and the transfer current in the dynamic current transfer process of the multi-break parallel VCBs is analyzed, which provides a reference for the selection of the vacuum interrupter of the multi-break parallel VCBs and the dispersion requirement of the fast repulsive mechanism.