SF₆ post‐arc recovery characteristics

Abstract

SUMMARYIn SF 6 circuit breakers, the result of the interruption, during the dielectric post-arc phase, depends on the capability of the arcing region to withstand the applied recovery voltage. An idealized model breaker experiment is designed to investigate the SF 6 recovery characteristics minimizing the effect of various factors such as metal vapor pollution, arc roots stagnation and gas-flow modifications. The gas heating is obtained by a power arc in movement. The experimental simulation of the interruption allows the study of the gas recovery behavior as a function of the decaying plasma properties. The so-obtained recovery characteristics exhibit distinct phases with recovery time increment and also dependencies on geometrical and electrical test parameters.

The effects of moisture and gaseous additives on SF6 recovery characteristics

“…The so obtained recovery curves present different phases with recovery time Át. These gases recover completely to their initial dielectric strength at times much longer than the value obtained for the SF 6 by our experiment [9]. After current interruption an SF 6 arc plasma recovers its dielectric strength very quickly, resulting in SF 6 circuit breakers being able to withstand high rates of rise of recovery voltage.…”