Interaction of coil type axial magnetic field electrodes applied to vacuum interrupters

Current commercial contact designs develop axial magnetic field for the purpose of forcing a high current diffuse arc in vacuum interrupter. The objective of this paper is to investigate the mutual influence between two coil type electrodes on the distribution of axial magnetic flux. Five different coil type AMF electrodes vacuum interrupters were analyzed by 3D finite element methods. The relative position of two electrodes was changed in three dimensions, one is the contact gap one is the twist angle by rotating one electrode and the third one is the center distance between two electrodes. The results showed that the distribution of AMF on the mid -gap of contact gap was the most uniform at a certain twist angle which is related with the number of coil type. There is no significant mutual influence of the twist angle and center distance on AMF on the contact surface between two electrodes when the contact gap becomes greater. The results can indicate the design and manufacture of AMF contacts.