Arc extinction performance of SF6gas blast interrupter

With a model SF6gas blast interrupter, arc extinction performance was investigated. The measurements were carried out for di/dt values ranging from 13 ∼ 27 A/µs, for RRRV extending from 3.5∼ 13.0kV/µs and for a fixed pressure of 15kg/cm². On the other hand, the voltage and current wave forms near current zero in the short line fault (SLF) test circuit were calculated employing Mayr´s equation and the interrupting capability was investigated using the arc time constant and arc voltage obtained from the experimental results. From this calculation, the following relation was found. RRRVc ∞ (i)-^(2.2∼2.45). The theoretical calculation was found to coincide satisfactorily with the experiments.