Simulation of the process of arc energy-effect in high voltage auto-expansion SF₆ circuit breaker

A new magnetic hydro-dynamics (MHD) model of arc in H.V. auto-expansion SF₆ circuit breaker that takes into consideration nozzle ablation due to both radiation and thermal conduction is presented in this paper. The effect of PTFE (polytetrafluorethylene) vapor is considered in the mass, momentum and energy conservation equations of the constructed model. Then, the gas flow fields with and without conduction considered are simulated. By comparing the aforementioned two results, it is indicated that the arc's maximal temperature with conduction considered is 90 percent of that without considering conduction.