Application of C6F12O/CO2 mixture in 10 kV medium-voltage switchgear

Due to the high global warming potential (GWP) of SF6, the use of new gases in electrical equipment has drawn increasing attention. Here, the application of environmental-friendly gas dodecafluoro-2-methylpentan-3-one (C6F12O) and CO2 mixture in 10 kV medium-voltage switchgear is studied. First, the basic physical and chemical properties of C6F12O were discussed, and the toxicity and safety of its application in equipment was analysed. Then, the breakdown voltage was measured in the laboratory. The power-frequency breakdown test was carried out with the mixing ratio of 2, 4 and 6% at 0.1 similar to 0.2 MPa, and the influence of utilisation coefficient of electric field on the breakdown performance was analysed. Finally, the appropriate mixing ratio was determined and tested in the load switch cabinet and the circuit breaker switch cabinet, including the power frequency withstand voltage test and the lightning impulse test. The test results show that 4% C6F12O and CO2 meet the standard value tested at a pressure of >0.14 MPa, which has the potential to be used as an insulating gas in a 10 kV switchgear.