Dielectric recovery in a high-voltage circuit breaker in SF₆

Abstract

Abstract The dielectric recovery in high-voltage circuit breakers after interruption of high-current amplitudes was investigated experimentally in a test device. Various current amplitudes were tested, which cover a typical range of practical interest. Simulations with computational fluid dynamics together with electric field simulations allowed one to deduce the physical parameters in the region where the breakdown was decided. A leader inception model using these parameters explains under which condition leader inception occurs; causing breakdown of the gap. Based on this model scaling laws for leader inception are given.