Arc Dynamics Near Current Zero in SF_6 Gas-Blast Arcs

摘要

The dynamics of circuit breaker arcs in SF_6 gas near current zero have been studied using a model circuit breaker system built around a plane-parallel, glass-sided nozzle which allows optical investigation of the whole length of the arc simultaneously. A gated, microchannel plate image intensifier was used to view the arc at several different times just prior to current zero. Exposure times were of the order of 1 ums. Gas pressures of 5 and 10 bar absolute were used together with a current of 1 kA peak. The main emphasis of the work was to examine the turbulence structures of the arc during interruption. The results of the study have shown a fine turbulence structure upstream of the nozzle throat and a more dynamic situation in the downstream region. These results may assist in the modeling of turbulence effects during interruption.