Numerical simulation method for the interrupting characteristic of SF ₆ circuit breakers

With the assumptions of LTE and LCE, an arc mathematical model for high current arcing stage in interrupting process of SF ₆ circuit breakers is set up on the basis of the conservation equations of mass, momentum and energy as well as the continuum equation of the arc current. The intense ohmic heating of the arc is considered by adding a source term in the energy equation. Radiation model and turbulent model are described. A unique mass conservation for the ablated PTFE is added into the overall conservation equations to take account of the nozzle ablation. A complete set of the governing equations is therefore constructed for the computer simulation of SF ₆ gas circuit breakers, especially for the large current phase, which forms the fundamental work for the establishment of the computer simulation tools for gas circuit breakers.