With the assumptions of LTE and LCE

an arc mathematical model for high current arcing stage in interrupting process of SF6 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 SF6 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.