Investigation about Influence on Breakdown Voltage by Arc Condition Befor Quenching

When the contacts of a circuit breaker are opened just before the current zero, the gap between the contacts after the current interruption will still be very short. Therefore, it cannot withstand the recovery voltage across the contacts after the interruption. In such a case, the multiple re-ignitions likely take place. Many investigators had tried to clarify this phenomenon, and many reports have been published. Generally, the high frequency current interruption and the dielectric recovery characteristics after the current interruption are relates to many parameters (value of the current, the arc time, and so on). In addition, the arc phenomena are very complicated. Hence, it looks difficult to understand these phenomena accurately. Therefore, we conducted the dielectric recovery test after the high frequency current interruption, and the observation experiment using the vacuum chamber in order to investigate the effect on recovery characteristic by the DC current before injecting with the high frequency current. At the end, we calculated the plasma density in the space between the electrodes after the high frequency current interruption by considering the result of the observation experiment and the dielectric recovery test. In this paper, the result about the experiments and the calculations are reported.