Characteristics of the arc voltage under different profiles of axial magnetic field were investigated experimentally in a detachable vacuum chamber with five pairs of specially designed electrodes generating both bell-shaped and saddle-shaped magnetic field profile. The arc column and cathode spot images were photographed by a high speed digital camera. The dependence of the arc voltage on arcing evolution is analyzed. It is indicated that the axial magnetic field profile could affect the arc behaviors significantly, and the arc voltage is closely related to the arc light intensity.
Based on a two-dimensional axisymmetric magnetohydrodynamic （MHD） model, the vacuum arc characteristics under four kinds of axial magnetic fields （AMFs） are analyzed, which include a bell-shaped AMF generated by a pair of commercial cup-shaped electrodes, and three kinds of saddle-shaped ones generated by three pairs of newly designed electrodes. The simulation result indicates that the effect of AMF on the vacuum arc characteristics is significant. A comparison between the simulation result and experimental one shows that the distribution of the simulated ion density integrated along the viewing path is in agreement with the image of the arc column. Both the simulation result and the experimental one show that, among the four kinds of AMFs, the saddle-shaped one with the highest strength is the best, which could resist the constriction of the vacuum arc more efficiently, while the saddle-shaped one with the lowest strength and the bell-shaped one are the least desirable.
In vacuum switch devices, the connection bus bar out of the vacuum interrupter will generate a transverse magnetic field in the arc column region, and under the influence of this magnetic field, the whole arc column will deflect from the electrode center, thus leading to deflected anode erosion. In this paper, a two-dimensional deflected anode erosion model is established, anode erosions under different deflection distance are simulated and analyzed, and results of anode surface temperature, anode melting and surface evaporation flux are obtained. The simulation results show that the deflected heat flux density will lead to deflected distribution of anode temperature, saturated vapor pressure and vapor flux correspondingly, and the morphology of the anode melting pool has also the same deflection. Moreover, the anode center temperature and its gradient along the y direction decrease with the increase of deflection distance. On the contrary, the temperature of the anode side surface, toward which the heat flux density deflects, increases with increasing deflection distance. Related experiments also verify the correctness of the model and simulation results.
