Decomposition Characteristics of SF6 under Arc Discharge and the Effects of Trace H2O, O2, and PTFE Vapour on Its By-Products

The research on decomposition characteristics of SF6 and its by-products have great significance to the operation, maintenance, condition assessment fault diagnosis power equipment. In this paper, particle composition models SF6, SF6/polytetrafluoroethylene (PTFE), SF6/PTFE/O2, SF6/PTFE/H2O, SF6/PTFE/O2/H2O were established by using Gibbs free energy minimization method, effects trace H2O O2 impurities PTFE vapour studied models. order verify correctness simulation results, a series breaking experiments carried out 40.5 kV circuit breaker, gas chromatograph was used detect analyse by-products. It found that when is involved in arc plasma, main by-product after quenching CF4, molar fractions C2F6 C3F8 are very low. When involved, SOF2, SO2 SO2F2, small amount CO CO2 also produced. HF, SO2, CO2, CO, SO2F2 H2 experimental results good agreement with above results.