Abstract
In this paper a novel coil axial magnetic contact for vacuum interrupters is designed and its magnetic field distribution has been analyzed. This asymmetric contacts structure have a static contact with two coils in series and a moving contact without any coil. The structure of the moving contact is simplified. Its strength will be enhanced, and its weight will be reduced, which is helpful to raise the breaking speed of the vacuum interrupter. Using finite method the 3-D electrode model has been built and the simulation carried out. With the current value at maximal and zero, the axial magnetic field distribution at static contact surface, at moving surface, and at the middle surface between the static and moving contacts have been calculated. And the phase delay time of the axial magnetic field is considered as well. The simulation results provide that this asymmetric axial magnetic field structure can generate strong and uniform axial magnetic field. The residual magnetic field is small and its phase delay time after the current zero is short.