Experimental investigation on the characteristics of vacuum arc in the process of DC interruption based on artificial current zero

The characteristics of vacuum arc in the process of DC interruption based on artificial current zero is investigated experimentally in this paper. A detachable vacuum chamber was used as the main switch. The countercurrent with frequency of 1kHz supplied by an LC circuit was injected by a thyristor. The shape of arc column was investigated with the aid of a high speed digital camera with an exposure time of 2 microseconds. The influence of axial magnetic field distributions on the characteristics of vacuum arc, particularly, on its evolution in initial drawn arc stage, was mainly investigated. The appearance of arc column during the interruption current falling to zero was also investigated.