Simulation of the Effect of a Metal Vapor Arc on Electrode Erosion in Liquid Metal Current Limiting Device

The effect of arc plasma on electrode erosion in a liquid metal current limiter （LMCL） is studied. Based on a simplified two-dimensional magnetohydrodynamic model, the elongated GaInSn metal vapor arc and its contraction process in a liquid metal current limiter are simulated. The distributions of temperature, pressure and velocity of the arc plasma are calculated. The simulation results indicate that the electrode erosion is mainly caused by two high temperature gas jet flows arising from the pressure gradient, which is a result of the non-uniform arc temperature distribution. The gas flows, which act as jets onto the electrode surface, lead to the evaporation of the electrode material form the surface. A redesign structure of the electrode is proposed and implemented according to the analysis, which greatly increased the service life of the electrode.