The experimental study of long-gap vacuum arc

In this paper, experimental system to measure long-gap vacuum arc characteristics was established. A single-frequency oscillation circuit was applied to provide short-circuit currents, and the contacts were set in a demountable vacuum chamber. The arc mode transition of axial magnetic field electrodes was observed by a high-speed charge coupled device (CCD) video camera while the arc current and arc voltage were recorded. A triggering device was designed and manufactured to ignite the vacuum arc. Three AMF contacts with different structure were designed and manufactured, and they were tested under different gap distance, different current and different diameter of electrode. The magnetic field at contact gap was simulated and analyzed by using 3D finite element software Ansoft. Based on the tests and simulation results, effects of AMF, gap distance and diameter of electrodes on long-gap vacuum arc characteristics were analyzed, and long-gap vacuum arc characteristics were summarized.