Interruption process and droplets emission in vacuum arc for aviation intermediate-frequency power supply system

In order to research the interruption process of vacuum circuit breaker in aviation intermediate-frequency (360Hz~800Hz) power supply system, vacuum arc experiments are carried out in interrupter with the diameter being 41mm and with the contact material being CuCr50 alloy. It can be indicated from the results as follows: With the increase of frequency and peak value of the current, both the peak value and the rise rate of the intermediate-frequency vacuum arc voltage increase, and the interruption ability decreases. However, the erosion of contacts is weaker for a shorter arc time, comparing to the power frequency current in the same value. When the vacuum arc reignites0, metal droplets are emitted from the contacts. The drive force is from the center of the contact to edge. If the density of plasmas and metal vapors and the numbers of the metal droplets come to a certain level, the arc may be broken down, which cause the interruption failed.