Arcless Commutation of Hybrid DC Circuit Breaker by using Electric Contact Made from Tungsten

Abstract

A hybrid circuit breaker comprises power semiconductor devices and a varistor connected in parallel with an electrical contact. In this study, we use SiC-MOSFET and the contact made from tungsten for hybrid DC circuit breaker to implement arcless commutation. We conducted current commutation experiment at the condition of DC 50 V, 150 A. As a result, contact erosions which have a depth of several tens of micrometer are observed in the case of commutation by arc discharge for a few microseconds. In contrast, the erosion was not observed completely in the case of arcless commutation.