Decomposition Characteristics of SF6 Under Different Spark Energies

For the purpose of utilizing decomposition component analysis (DCA) for fault diagnosis of SF6 gas insulated equipment further, SF6 spark decomposition experiments under different spark energies were carried out on the frequency and energy controllable SF6 spark decomposition test platform. The amount of gaseous by-products of SF6 sparks were measured by GC-MS. Atomic relative content of solid products were analyzed by XPS. The main gaseous by-products of SF6 sparks include SOF2, SO2F2, SOF4, SO2, as well as CF4, and the amount of them increases with spark number. The amount of SOF2 increases with single spark energy and tend to be saturated, while SO2F2 decreases. It depends strongly on the differences of both the energies consumed in SF6 dissociation process into SF5, SF4, SF2, and hydrolysis rates of SOF4 and SF4. Besides, CF4 increases with single spark energy and tend to be saturated, and SOF4 shows a linear dependence, but SO2 is hardly influenced by spark energy distinctly. In solid products, relative content of F, S, Fe, W increases with spark energy. The main existence forms of Fe include FeS, FeF3, Fe2O3, and pure Fe, thereunto the relative content of FeS and pure Fe increases with spark energy.