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.
Keywords: Vacuum interrupter, two segments coil, axial magnetic field contact, 3-D magnetic field, simulation
