The lifetime of a high-current triggered vacuum switch with multi-gap

Triggered vacuum switch (TVS) synthesizes the merits of spark gap and vacuum technology. A TVS sample with multi-gap is described in this paper, in which the main electrode is made up of spatially interleaved rods of opposite polarity on a ring. Three pairs of rods are adopted, which can form six main gaps, promoting the high current carrying ability evidently. Due to hundreds of high current pulses, the influence of vacuum arc to the trigger pin and main electrode is inevitable, leading to the termination of lifetime of TVS, especially in the erosion of trigger pin and arc deposition on the trigger surface. In this paper, the major influence factors of lifetime are analyzed and it is concluded that the main current arc is the key factor to determine the lifetime of TVS. As well the change of trigger voltage, trigger resistance and trigger delay will predict the termination of TVS lifetime.