Decomposition Characteristics of SF6 under Flashover Discharge on the Epoxy Resin Surface

摘要

In this paper, the flashover discharging experiment was carried out on epoxy resin surface in an SF6 atmosphere under pin-plate electrodes, with the electrodes distance from 5 mm to 9 mm. The concentration of seven characteristic gases was detected, indicating that the concentration of SOF2 and CF4 was the two highest, followed by SO2, CO2, SO2F2, CS2, and H2S. Based on the changes in the concentration of the characteristic gases, a preliminary rule was proposed to predict the occurrence of flashover discharge on epoxy resin: When the concentration of SOF2 reaches twice of CF4 concentration, and the total concentration of both SOF2 and CF4 is much higher than that of H2S, a possible flashover discharge on the epoxy resin surface in SF6-infused electrical equipment occurs. Through the simulation of decomposition of epoxy resin, it has been revealed that H2O has different generation paths that can facilitate the formation of SOF₂, finally influencing the concentration variation of the seven characteristic gases.