The invention relates to a
gas insulation technology of an
electric power system, in particular to a mixed insulating gas containing perfluorodimethyl
sulfide and application of the mixed insulating gas. The insulating
mixed gas is composed of a component 1 and a component 2, and the component 1 is perfluoromethyl
sulfide; and the component 1 is 1, 1, 2, 2-tetrafluoroethane, 2, 3, 3, 3-tetrafluoropropene and 1, 1-difluoroethane, and the component 2 is 1, 1, 2, 2-tetrafluoroethane, 2, 3, 3, 3-tetrafluoropropene and 1, 1-difluoroethane. The insulating
mixed gas provided by the invention has the insulating property equivalent to or even more excellent than that of
sulfur hexafluoride, has a lower GWP value, and is particularly suitable for gas-insulated electrical transformers, gas-insulated wires for transmitting or distributing
electric power, or connectors / disconnectors in the middle-
high voltage field. The
mixed gas disclosed by the invention has the characteristics similar to that of single gas, and the
liquefaction temperature of the insulating mixed gas is lower than that of each component; and the mixed gas also has an insulating synergistic effect, and has the advantages of low GWP,
low toxicity, low
boiling point and high insulating strength.