Analysis of the breakdown in single-chamber circuit breaker

A hydrodynamic model for electrical arc modelling was used to develop a 420 kV 50 kA single-chamber circuit breaker. Normally, in order to estimate the gas breakdown probabilities, calculations based on gas density and the electric field are used. A second approach involves the use of energy equations to determine the re-strike possibility trough the creation of a leader channel. Leader parameters and more accurate predictions are obtained by comparing the experimental results and the leader calculations. However, these criteria assume a re-strike in pur gas, which is not true after introduction of the self blast volume.