Hot SF6 breakdown calculations applied to high voltage circuit breaker

This paper is devoted to the breakdown electric field strength calculations of hot SF6 under the conditions of the usual dielectric recovery phase in a high voltage circuit breaker. This means that calculations are undertaken for a large temperature range (300 K up to 3000 K) and different gas pressures (1 up to 7 atmospheres). Calculations are based on a rigorous multi-term Boltzmann equation solution using improved cross section sets for the interactions between the electrons and the various SF6 dissociation products. The present breakdown electric fields show an interesting agreement with the sparse literature results. Then our results are used as input data in hydrodynamics simulation codes. This allows thus to correctly predicting the circuit breaker behaviours observed in the case of a successful breaking test and a failure one.