Research on Magnetic Field Distribution between Electrodes in Vacuum Interrupter

Abstract

Vacuum circuit breaker is a kind of power equipment widely used in the power system. It is developing toward the direction of high voltage and high current. How to design the contact to maximize the interrupting capacity of the contact system has been conducted by scholars. In this paper, the magnetic field simulation model of contact system is established, the magnetic field distribution characteristics of vacuum interrupters are studied, and the distribution characteristics of the magnetic field in the half cycle of the cup-shaped axial magnetic field contact system are simulated and analyzed. On this basis, by changing the contact structure parameters, the effects of the number of slots in the cup, the slot angle, the center hole of the contacts, and the length of the slots on the distribution of the axial magnetic field were obtained. The results show that grooving the contact can reduce the eddy current, but it has a limited effect on reducing residual magnetic field. The increase of slot angle of contact cup can effectively reduce the residual axial magnetic field at the zero current moment and the axial magnetic field intensity at the peak current moment. Based on the above research results, a new embedded axial magnetic contact system with 12 slots embedded magnetic ring and reverse contact cup is designed. The embedded magnetic ring and reverse spiral slot increase the axial magnetic field at the peak current moment and reduce the residual axial magnetic field at the zero current moment. Finally, the characteristics of the magnetic field have been improved significantly compared with the magnetic field of traditional cup-shaped axial magnetic field contact.