3D numerical simulation of vacuum arc with anode vapor in actual magnetic fields

Abstract

Characteristics of vacuum arc seriously influence the interruption ability of vacuum switches. In many cases (especially in commercial electrode systems), vacuum arcs are not completely axial symmetrical configuration. So, three-dimensional simulation of vacuum arc is needed. On the other hand, when the interruption current is very high, the anode will be in active state and becomes another source of inter-electrode plasma. In this paper, a time dependent actual magnetic field generated by commercial cup-shaped axial magnetic field (AMF) electrode is simulated. With this magnetic field and the simulation results of anode temperature, the dynamic characteristics of vacuum arc considering anode vapor pressure (also considering simplified cathode spots diffusion and open process of electrode) are obtained. In the simulation results, the magnetic field distribution of commercial cup-shaped electrode is six leaves shape, and so do other parameters. There are some ions pressed by high anode vapor pressure from anode to arc column.