Petchanka Arkadz

The paper deals with the utilization of an improved model for the ablation process in the simulation of on-load switching-off processes in high-voltage circuit breakers (HVCBs). In order to describe the plasma arc behaviour, a transient axisymmetric model is used which is based on the @Fluent software. The presented arc model uses mixed formulations for the calculation of the self-induced magnetic field and the radiative transfer. The proposed ablation model is validated by the comparison of the measured and simulated ablated mass and pressure build-up in the heating volume. It is shown that the consideration of PTFE evaporation enthalpy in dependence on pressure yields to best agreement between experiment and simulation. Nevertheless, the approximation of the constant enthalpy stays in a satisfactory agreement with the measurements at the interruption current 25 kA.