Experiment research on current chopping on zero period of DC vacuum circuit breaker breaking

Dielectric recovery after arc extinguishes in vacuum circuit breaker is very fast, the arc current may be cut off before natural current zero. In order to study the current zero period phenomenon of DC circuit breaker based on commutation principle, this paper studies the current chop phenomenon of low current middle frequency vacuum arc interruption in DC vacuum breaker. The average current chopping value of middle frequency arc is obtained in experiment, and the effect of commutation frequency on current chopping value is analyzed. The voltage of the fracture is measured during current chop period. The results show that with the increase of commutation frequency, the chop off value is on the rise. High frequency oscillation is superimposed on the voltage and current waveform before current chop. The effect of breaking current value, arcing time and capacitance value of parallel RC snubber branch on the chop off value is also analyzed. The experimental results also show that the chop off value of middle frequency arc increases with the increase of the commutation frequency and the parallel snubber capacitance value, decreases as the breaking current and arcing time increase. The experiment provides a reference for further analysis of middle frequency arc.