Partial discharge characteristics of C6F12O/CO2 mixed gas at power frequency AC voltage

The greenhouse effect of SF6 has made its application in various types of gas-insulated equipment increasingly restricted. C6F12O combines the advantages of insulation strength, safety and environmental friendliness and is considered to have potential for use in medium and low voltage equipment when mixed with buffer gas. In this paper, an experimental study on the partial discharge characteristics of C6F12O/CO2 mixed gas was carried out. The partial discharge initial voltage and the partial discharge extinction voltage of the mixed gas under the power frequency voltage are measured, and compared with the breakdown voltage. It was found that the partial discharge initiation voltage and the extinction voltage of the mixed gas gradually increased with the mixing ratio, and the influence of the gas pressure on the high mixing ratio was large. Compared with pure CO2, the difference between the partial discharge starting voltage and the breakdown voltage of the mixed gas is large. The research in this paper can provide guidance for the operation and maintenance of C6F12O mixed gas in the application of medium and low voltage equipment.