Study on the characteristic components of SF6 decomposition products of gas insulated switchgear inner insulators under abnormal heating

The abnormal heating test model of GIS internal insulation was established. The abnormal heating test of aluminum-filled basin insulator under steady state current was carried out. The content of SO2, H2S and CO2 remained stable at the beginning of the experiment, and the content of SO2, H2S and CO2 increased obviously when the experiment reached a critical point. The abnormal heating test model of the inner insulator of the gas insulated switchgear was established. The overheat test of solid insulation was carried out under the condition of 0.3 MPa absolute pressure in the gas chamber and without adsorbent. The overheat fault duration was 6 h and the overheat fault temperature was respectively 200℃、250℃, 300℃ and 350℃, the decomposition products of SF6 are CO, CO2, SO2, SOF2, H2S, COS and CF4. The generation mechanism of SF6 decomposition products under abnormal conditions is also analyzed to guide the judgment of internal faults and operation defects of equipment on site and ensure the safe and stable operation of power grid equipment.