System Development And Characteristics Research On Sulfur Hexafluoride Spark Decomposition

Due to its excellent insulation and arc-suppressing performance, the insulation gas SF6 is widely applied to SF6 insulation gas equipment. However, some initially harmless defects within those equipments will develop into prominent ones under high pressure with the increase of running time. It can develop from partial discharge to spark discharge even arc discharge slowly, then become serious threats to the stability of the equipment and normal operation of the grid. The previous research shows that SF6 can decompose under spark discharge. According to the SF6 decomposition components and content variation law of the spark discharge, the type and severity of the fault can be effectively diagnosed.A SF6 spark discharge simulation platform was designed in a laboratory in this article, which has a precise control of discharge frequency and discharge energy. On the basis of the platform, the decomposition characteristics of SF6 under different energy was initially studied in this paper. The main workflow and conclusion is as follow:① A SF6 spark discharge simulation platform was designed successfully in a laboratory, which has a precise control of spark discharge frequency by the effective control circuit. At the same time, the appropriate spark energy measurement and calculation tools was selected to achieve a reasonable calculation of the spark discharge energy.② The analytical method GC/MS is finally established,which was used to separate the SF6 spark decomposition components effectively after repeated researches. The quantitative correlation analysis was achieved by using standard gas of each decomposition components. Then a standard mass spectra was developed. The quantitave and qualitative detection of SF6 decomposition component was based off on this analytical method.③ According to the decomposition experiment on SF6 spark discharge simulation platform. SF6 will decompose into CO2、SOF2、SO2F2、SOF4、SO2 and CF4 under spark.④ Conducted SF6 decomposition experiments to disover SF6 decomposition characteristics with different discharge energy. Experiment results reveals that the decomposition components content with different spark discharge energy values showed the same relationship, SOF2>CO2>SO2F2>SOF4>SO2>CF4. What’s more, SO2F2、CO2、SOF2 are always the main decomposition components. The increase of the spark energy make a contribution to the generation of the decomposition components, but it depends on the type of the decomposition components.The research achievements laid a stable foundation for the future research on SF6 insulation gas decomposition characteristics and decomposition mechanism under spark discharge fault.