Influence of Contacts Diameter on the Vacuum Arc Characteristics of Spiral-type Contacts

摘要

The transverse magnetic contacts has been successfully applied in medium voltage power distribution systems. Based on the current development, the influence of diameter of spiral-type contacts on the vacuum arc characteristics was studied in this paper. The 3-D finite element simulation models of spiral-type contacts with different diameters were established. Then the transverse magnetic field (TMF) and the axial magnetic field (AMF) on the cathode contact surface were simulated. The variation of electromagnetic force while the arc column traveling along the contacts arms was calculated. Besides, the vacuum arc characteristics and the arc voltage changes during three arcing stages were investigated by experiments, and the arc energy of different diameters contacts was analyzed. It was found that the ratio between the maximum value of AMF and TMF of 30 mm diameter contacts was 0.312, and the 48 mm diameter contacts had the ratio of 0.646, which could make an impact on arc mode transformation and arc movements. This paper could provide reference for the design of vacuum interrupters with TMF contacts and the research of vacuum arc.