FEASIBILITY STUDY ON THE VACUUM ARC MODELLING WITH AN AXIAL MAGNETIC FIELD

An axial magnetic field (AMF) electrode has more advantages of the switching capability than other contact designs such as reducing the arc voltage, securing higher current value for transferring from the constriction arc to the diffused arc, and regulating the arc current distribution. The arc constriction would increase the heat flux and the local temperature on the electrodes, and result in the surface melting, which make undesirable influences on the characteristics of a vacuum arc interruption. In the present study, we calculated the magnetic fields with the AMF electrodes using by a 3-D FEM software, ANSYS, and analysed the effect of the applied AMFs between the electrodes using the effective arc area. Also the thermal characteristics with the applied AMFs were calculated using by a 2-D arc modelling with a commercial CFD code, PHOENICS, for the feasibility study on a vacuum arc modelling. The detailed approaches on the vacuum arcs with 3-D coupled fields analyses are being in progress for a practical purpose.