Study on the Influence Rules of Trace H2O on SF6 Spark Discharge Decomposition Characteristic Components

To figure out the influence rules of trace H2O on SF6 decomposition characteristic components under spark discharge, a series of spark discharge decomposition experiments with various H2O contents were performed using needle-plate electrode to simulate metal protrusion insulation defect. The changing rules and mechanisms of five decomposition characteristic components were achieved quantitatively, indicating that no matter how much H2O was, there exist five main decomposition components: CF4, SOF2, SO2, SOF4 and SO2F2. The contents of the five decomposition components increased with the time extended, and resulting in the contents of SF6 spark decomposition components by the order: SOF2 > SO2F2 > SOF4 > SO2 > CF4. Additionally, the higher H2O content is, the stronger promoting effect on the generation of SO2F2, SOF2, SOF4 and SO2 is.