Voltage operating range of field distortion spark switch at repetition frequency

A set of nanosecond pulsed power supply was set up with a field distortion spark switch under atmospheric air, and the voltage operating range of the switch triggered to breakdown at different repetition frequencies (from 50 Hz to 1300 Hz) as well as the effect of blowing were investigated. The voltage waveforms were recorded with a high voltage probe and a digital oscilloscope. Experimental results show that when the switch operates stably (voltage below 30 kV and current below 300 A), the highest repetition frequency is 1300 Hz. Due to incomplete recovery of gas insulation after the switch breaks down, both the maximum operating voltage V_\mathrmm\mathrma\mathrmx and the minimum operating voltage V_\mathrmm\mathrmi\mathrmn when operating stably decrease with increase of repetition frequency. The voltage operating range ( V_\mathrmm\mathrma\mathrmx-V_\mathrmm\mathrmi\mathrmn ) is wide at low frequency and narrow at high frequency, which is about 10 kV at low frequency 50 Hz and very small at high frequency 1300 Hz, only about 0.5 kV. This is because the insulation level is low at high frequency, and the trigger pulse has little effect on breakdown, so the actual operating voltage under trigger condition is closer to the current self-breakdown voltage. Blowing can accelerate gas insulation recovery and increase the maximum and minimum operating voltage. If the maximum operating voltage is higher than 90% of the self-breakdown voltage of 30 kV before operation, the repetition frequency is lower than 50 Hz without blowing and goes up to 500 Hz with blowing.