Research on Internal and External Factors Affecting Current Commutation in Vacuum

Current commutation is the prerequisite for hybrid DC circuit breakers to interrupt the current successfully, and it is also critical to realize fast current limiting of fault current limiter (FCL). In order to overcome the difficulty of current commutation in vacuum arc current, the influence factors of current commutation, which include the amplitude of commutation current, the phase of commutation current and the breaking speed of the switch, were studied through experiments. At the same time, the influence of external transverse magnetic field (TMF) added to the vacuum arc for promoting current commutation was studied. Current commutation experiments were performed where the commutation branches are composed of resistance, inductance and semiconductor devices respectively. The peak value of the test current range is 2-6 kA and the phase range is 0-180°. The effect of various factors on the current commutation is analyzed through theoretical and experimental results, and reasonable parameters that can promote current commutation are summarized.