Development of Numerical Model for Small-Current Vacuum Arc Decay Process Using a Hybrid of Moving Particle Semi-Implicit Method and Finite Volume Method

In this study, a hybrid numerical simulation model using the moving particle semi-implicit (MPS) method and the finite volume method (FVM) was constructed to analyze vacuum arc discharges. Vacuum arc discharges can be seen in vacuum circuit breakers (VCBs). The VCBs have been receiving much attention from their low environmental impact, because they do not use SF6 gas in the interrupter. In order to improve the current interruption performance of such VCBs, it is important to understand the behavior of vacuum arcs, such as the distribution of metal vapor and ionization and excitation states that affect electrical conductivity. In this article, the arc characteristics of the vacuum arc decay process and its dependence on the current decay rate were studied. Results indicated that the gradual decrease in current to 10 A maintained high evaporative vapor amount above 60 kg/(m(2)& sdot;s) . This suppressed the decrease in the number of heavy particles between the electrodes.