Optimization of dead tank gas circuit breaker design based on quantification of hot gas flow and dielectric properties

This paper describes the technologies for developing a compact and highly reliable dead-tank gas circuit breaker (GCB) on the basis of extensive data on the behavior of hot gas flow and the mechanisms of ground fault under highly inhomogeneous thermal conditions. When predicting the dielectric capability of a GCB during a large current interruption, the temperature and gas density distributions caused by the hot gas must be taken into account in addition to the electrical field imposed across the gas. Hot gas behavior was investigated quantitatively and qualitatively, to provide a basis for determining optimum exhaust tube dimensions which minimize overall circuit breaker dimensions while avoiding ground faults.