STUDY OF THE POST-RECOVERY CURRENT IN SF6 CIRCUIT-BREAKERS

A sustained current conduction in the breaking chamber after a current interruption has been observed. This current, which we named 'Post-re covery PR current', is in phase with the applied voltage and its value ranges from several milliamps up to several amps. The present study s hows that the probable origin of the PR current is an ionic conduction of SF6 between the contacts. The estimated temperature of the conduct ing gas is about similar to 2000 K. The evolution of the temperature i s in a good accordance with a computational model based on the resolut ion of two-dimensional Navier-Stokes equations.