Three-Dimensional Arc MHD Simulation of MCB Considering Contacts and Splitter Plates Ablation

The accurate simulation model of arc magnetohydrodynamics requires consideration of the ablation of contacts and splitters plates. This paper establishes the energy balance equation based on the different action mechanisms of the arc-anode and arc-cathode. It introduces calculation formulas for arc root radius and energy distribution proportion to develop the evaporation ablation model of metal materials. Additionally, nonlinear resistance is incorporated to compute the sheath voltage of the splitter plates. The external AC circuit is coupled to realize data linkage between the external circuit and dynamic arc of the miniature circuit breaker (MCB). Additionally, it considers the influence of copper vapor produced by contacts and iron vapor produced by splitter plates mixed with air on thermodynamics, transport and radiative properties of plasma. Furthermore, a three-dimensional calculation model is employed to more accurately simulate the structure of contacts and splitter plates. The simulation results show that considering the influence of ablation vapor, the arc voltage decreases and the arc motion slows down. The structure of arc extinguish chamber can be optimized according to the generation position and diffusion of ablation vapor.