Experimental research on insulation properties of C6F12O/N2 and C6F12O/CO2 gas mixtures

This study investigates the insulation performance of the new environmental friendly insulation gas C6F12O mixed with N-2 and CO2 under the AC frequency voltage under 0.10-0.30 MPa. Firstly, the mixing ratio of C6F12O in the mixed gas is discussed by the gas phase state equation. The breakdown voltage of C6F12O gas mixtures under quasi-uniform electric field and the initial voltage of partial discharge in the highly non-uniform field are measured by the experimental method, and the insulation characteristics of SF6 gas mixtures are compared. The self-recovery performance of the gas mixture is analysed as well. Experimental results show that the mixing ratio of C6F12O is lower than 7% under 0.10 MPa, such that the operation requirements of the equipment can be satisfied. The breakdown voltage of 3% C6F12O gas mixtures is the same as that of 10% SF6 gas mixtures. The partial discharge inception voltage of 6% C6F12O gas mixtures is close to that of 10% SF6 gas mixtures. After 100 times of breakdown, the breakdown voltage of C6F12O gas mixtures does not decrease. Compared with N-2, the breakdown voltage of C6F12O mixed with CO2 shows a more dispersive trend.