ABSTRACT The breakdown characteristics of the novel eco‐friendly insulating gas CF 3 SO 2 F are fundamental to the design of gas‐insulated equipment. In this paper, the gas mixture parameters for CF 3 SO 2 F were optimised for different ambient temperatures in order to ascertain the insulation performance and liquefaction temperature constraints. To further assess its insulation properties, breakdown experiments were carried out under power‐frequency voltage (50 Hz), considering the influence of buffer gas types, the molar ratio of CF 3 SO 2 F and pressure. The results demonstrate that the breakdown voltage of CF 3 SO 2 F is 1.2–1.5 times that of SF 6 , and it increases with pressure in the range of 0.1–0.4 MPa. When compared to air and CO 2 , N 2 exhibits a superior synergistic effect with CF 3 SO 2 F. At an absolute pressure of 0.5 MPa, the 60% CF 3 SO 2 F/40% N 2 mixture shows similar insulation strength to SF 6 , but it can only be applied in environments above 10°C. Furthermore, the 12% CF 3 SO 2 F/88% N 2 mixture at an absolute pressure of 0.8 MPa has an insulation strength comparable to that of 0.5 MPa SF 6 , with a liquefaction temperature of −25°C. The results demonstrated great potential of industrial applications. At this configuration, global warming potential (GWP) of the gas mixture is only 4% that of SF 6 . The research provides a new solution for SF 6 gas substitution in gas‐insulated equipment.
Ren et al. (Sat,) studied this question.