Experimental and Simulation Research on Influence of Axial Magnetic Field Components on Vacuum Arc Between Transverse Magnetic Field Contacts

The vacuum transverse magnetic field (TMF) contacts have the advantages of simple structure, short current path, and low cost. Arcing process and arc characteristics between the TMF contacts directly determine the temperature distribution and ablation of the contact surface, which are closely related to the breaking ability of the contacts. The axial magnetic field (AMF) component generated by the TMF contact structure also affects the arcing process. In this paper, five kinds of contacts with different starting positions of spiral slots were experimentally investigated in a demountable vacuum chamber. The arc appearance and the arc characteristics during different arcing stages and the surface utilization of the contacts were analyzed. The magnetic characteristics of arc in different stages were simulated. It was found that the arc with small AMF component has a large diameter and small range of motion. The arc with large AMF component might jet toward the outside of the interelectrode.