A Study on Dielectric Breakdown Properties of Hot CO2/O2/C5F10O Gas Mixture: Focus on Concentration Rate of O2 Gas

A gaseous mixture of CO 2 and C 5 F 10 O has been widely investigated as one of the alternative gases for SF 6 . Due to the better electron attachment ability of oxygen molecule O 2 , it is generally expected that adding of O 2 gas would improve the dielectric strength of arc quenching and insulating gas for electric power equipment. Therefore, in this paper, the dielectric breakdown properties of hot CO 2 /O 2 /C 5 F 10 O gas mixture were numerically estimated. The calculation results revealed that the critical electric field strength of the CO 2 /C 5 F 10 O gas mixture is disappointingly decreased by the addition of O 2 gas, especially in the temperature range of 3000 K to 1000 K. This is brought about by the increase of ionization reaction of CO 2 molecules with an increase in the O 2 concentration in the arc‐quenching gas of CO 2 /O 2 /C 5 F 10 O. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.