CFD in circuit breaker research & development

The development and optimization of circuit breakers is nowadays strongly influenced by computational fluid dynamics (CFD) simulations. The main reason is that the corresponding experiments are expensive and provide only limited amount of data, usually in integral form. On the other side, CFD allows analyzing the transient behavior of all quantities described in the models. This contribution collects a number of CFD related activities for circuit breaker research and development at ABB Corporate Research. In the simulations reported here, the plasma is treated as a one fluid model, i.e. the molecular processes such as dissociation and recombination are only reflected by pressure and temperature dependent material properties. The paper introduces the CFD model with radiation transport and the coupling to the electro- and magneto-static field equations. The predictive power of these simulations is demonstrated through comparison with results from a small scale test device (mixing of hot gas in a heating volume) and a full breaker (arc voltage and pressure rise).