Experimental Investigation of Transient Vacuum Arc with Incremental Oscillation Current Injection Under Different Frequencies and Contacts

Due to its exceptional performance and cost-efficiency, the voltage source converter assisted resonant current direct current circuit breakers topology has attracted widespread attention. The novel topology is characterized by high-frequency incremental oscillation current injection into vacuum interrupter. The transient arcing process plays a pivotal role in the vacuum arc extinction and current interruption. The objective of this paper is to investigate the transient arcing process with high-frequency incremental current injection. The impacts of contact type and current frequency on the transient vacuum arc characteristics are studied through a series of experiments. A high-speed camera is used to capture the transient arcing process in detachable vacuum chamber. Since the high-frequency incremental current is injected, the arc intensity is proportional to the arcing current and varies periodically. The cathode spot gathering phenomena has been observed at low current during rising period. The AMF contacts which control the transient arc in diffuse mode before currentzero have the best performances for different frequencies and are proposed for the application.