Numerical simulation of SF6 arc characteristics influenced by electrode erosion

During the interruption process of SF₆ circuit breaker, electrode erosion will occur inevitably, which leads to the contamination of pure SF₆ and the alteration of arc characteristics. In the paper, to one puffer type circuit breaker, simulation studies are focused on the application of Spalart-Allmaras model for turbulence and species transport model for metallic vapour diffusion. In addition, the electrode erosion rate is estimated by the energy balance processes at the arc and electrode interface. It demonstrates that the metallic vapour has cooling effects especially at the region close to upstream electrode, and the arc voltage is less sensitive to electrode erosion at lower current.