火花放电下SF₆特征分解产物演化特性研究

Discharge faults (such as spark, arc and partial discharge) in high voltage SF₆ switchgear will induce SF₆ decomposition into low fluorine sulfides. However, the recombination of SF₆ molecules caused by the decreasing discharge temperature can still guarantee good insulation and arc-quenching performance of high voltage SF₆ switchgear. When the low fluorine sulfides react with the unavoidable trace moisture and oxygen impurities,the generated corrosive products will threaten normal operation of the high voltage SF₆ switchgear. Therefore, it is possible to make use of the characteristic SF₆ decomposition products to detect discharge faults. This study employs gas chromatograph to investigate the evolution of characteristic SF₆ decomposition products, like SOF₂,SO₂F₂ and SO₂,under spark discharge. The results show that the molar fractions of these products increase with the contents of moisture and oxygen,and the increase in the spark discharge energy also makes contribution to the generation of these products. This work may provide theoretical basis for fault diagnosis and condition online-monitoring of high voltage SF₆ switchgear.