Operational Characteristics of a Field-Breakdown Triggered Vacuum Switch

Abstract

Triggered vacuum switch (TVS) is one of the important switch apparatuses in the fields of high-pulsed power system. Its working lifetime is due to trigger failure of the trigger pin, so the parameters of trigger source become the key of lifetime dilatation. A sample of field-breakdown TVS coated with nothing is fabricated, which has much longer lifetime than the TVS coated with trigger materials, but more trouble in the trigger process. A trigger system and a LC test circuit are designed to find the operational characteristics of the TVS sample. The trigger system generates a negative pulse with peak value of 30 kV/500 A, the system delay and its scatter is controlled in 70-100 mus, and the triggered rate of success reaches 96%. Test results show that the sample has a wide working voltage range of 0.3-40 kV. The delay of its switching-on is stable in hundreds of nanoseconds, which will be reduced with the increase of main gap voltage. The arcing is steady in the conducting process, keeping arc voltage at 20 V approximately. The arc current drops to zero as current zero is approached, leading to a voltage remained in the capacitance.