Electric Arc Simulation Validations and Switchgear Applications

In this paper, we focus on the validation of numerical simulation of electric arcs in gas. The core of the electric arc reaches a local thermal equilibrium (LTE) state, which primarily determines its behaviour. In contrast, the regions near the anode and cathode and outside the arc core are in a non-LTE condition. This work mainly discusses the modelling of the near-anode and near-cathode regions and the arc core. We use a magnetostatic approach to calculate the Joule heating loss and the Lorentz force within the arc. To model the regions near the anode and cathode, we introduce nonlinear conductivity dependent on current density to simulate voltage drops near the electrodes. The anode and cathode surface losses are then determined based on these voltage drops. Computational fluid dynamics (CFD) simulations are used to calculate the electrical conductivity and temperature of the arc at each iteration. Multi-species models that incorporate local species concentrations are used to account for metal and insulation vapor. Various thermal radiation models can be applied to improve the accuracy of electric arc simulations. High-performance computing (HPC) is used to meet computational demands and reduce simulation time. To validate the proposed simulation workflow, we focus on two benchmark cases and compare the simulated results with the experimental results from literature. Switchgear electric arc simulation is a challenging topic, due to complex physics, examples are shown as application of the simulation workflow to understand the complex electric arc process.