Study on the Performance Degradation of an Ejected-Plasma-Triggered SF6 Gas Gap for 10-kV Smart Distribution Network

The plasma injection driven by pulse transformer could trigger the gas gap conduction at extremely low operation coefficients, and it was a potential technology to realize the rapid control and protection of the 10-kV smart distribution network which required high potential isolation, but the stability of trigger performance remained to be further studied. In this paper, the degradation of plasma jet trigger performance in high pressure SF6 was studied, focusing on the trigger voltage, current and gap conduction delay. The result showed that under the action of 2kV, the SF6 gas switch with 4kV gap voltage was successfully triggered 804 times continuously, and the range of the conduction delay was 80-120µs, as the number of triggering increased, the ablation of the trigger cavity increased, and the conduction delay increased gradually. Based on the research, the performance monitoring method and life change rule of the plasma injection driven by the pulse transformer was mastered, which was of great significance for its application in engineering and life improvement.