Prediction and improvement of dielectric breakdown between arc contacts in Gas circuit breaker

Abstract

Arc energy affects strongly the performance of circuit breaker. Especially it is the important note that hot gas distribution and pressure rise generated by arc can cause dielectric breakdown and restrike in gas circuit breaker after a fault current is interrupted. For the intimate observation of such phenomena and then designer's better understanding in this study, it carried out the calculation of the hot gas flow characteristics by arc and electric field intensity from transient recovery voltage during contact separation in gas circuit breaker using commercial CFD program. For the modeling of circuit breaker, it required the technologies including the movements the mechanical contacts using moving mesh, the initialization and extinction of an electric arc and nozzle ablation as the physical phenomena. At the conclusion, it will be discussed about the relation between heat transfer and performance prediction and shown about the effect of design index to stabilize thermal distribution.