Analysis of current transfer process during the open operating in large current vacuum interrupters with dual-contact

A new type of “dual-contact” structure of vacuum interrupter is proposed in the paper. It consists of main contact and arc contact, which are used to carry rated current and break short circuit current, respectively. During the closing/opening of vacuum circuit breaker, arc contact is first closed and post breaking, however, main contact is post closed and first breaking. So there must be the current transfer process. In this paper, during the breaking process of vacuum circuit breaker, a model of current transfer is used in the investigation of current transfer, and the maximum possible current transfer time is obtained. This analysis is helpful to the research of large current vacuum interrupters with dual-contact.