Investigation on the axial magnetic field of cup type vacuum interrupter considering the geometry of contact support

The vacuum interrupter (VI) uses the axial magnetic field (AMF) type electrode structure to secure the current interrupting performance in long contact gaps. The AMF electrode has contact support made of stainless steel (SUS) to improve mechanical strength, but it could inevitably reduce the AMF. As a solution to increase the AMF, it is necessary to suggest a suitable geometry of contact support considering mechanical strength, but the related studies are insufficient. In this paper, we proposed geometries of the contact support (e.g., slits type, new type) to improve the AMF. In addition, the magnetic field analysis with COMSOL Multiphysics was carried out to compare the AMF of the conventional geometry of contact support with that of the proposed geometries. Consequently, the Simulation results showed that the AMF of proposed contact supports better than the conventional one.