Experimental Study on Relationship between Breakdown Temperature and Decomposition Products of SF6 gas

SF6 circuit breaker has been used on electrical breaking equipment in a variety of voltage levels. Presently, moisture and pressure(density) inspection of gas has been applied on running SF6 electrical equipment, lacking of researches about the relation between decomposition product of SF6 and the equipment failure, which is necessary for directing practical work. In this paper, a SF6 gas-insulated transformer case is used as a test vessel to conduct partial overheating test, and the results are compared with the simulated hot temperature of the equipment. It is concluded that SF6 gas sequentially generates HF, SOF2, SO2, SO2F2 in the process of increasing heating temperature, and the generation temperature range of them in the process is determined, which is intended to provide a reference for evaluating and judging the internal fault of the equipment effectively. This study has a positive significance for evaluating the electrical state of SF6 and judging the nature of internal faults in equipment. It is of decisive significance for evaluating electrical states of SF6 and judging properties of internal faults in SF6 gas-insulated equipment.