Experimental investigation of arc characteristics in medium-voltage DC circuit breaker

Within this paper, the arc characteristics in a typical air DC circuit breaker (DCCB) are studied through experimental approach. A specially designed experimental setup is employed to observe the dynamic process of arc evolution. The phenomena of arc commutation and arc stagnation under fault currents are revealed according to the high-speed photography and arc voltage curves. The influence of arc currents on the detailed arc behaviors is preliminary discussed. It is found that the arc would burn continuously between the contacts when the arc current decreases to a relatively small value. Assisting measures should be employed to help the switch interrupt the small arc current. Finally, a simple magnetic system is designed to increases the magnetic driving force of arc motion. And the interruption characteristics of the switch with the external magnetic field are investigated.