Experimental research on insulation properties of C 6 F 12 O/N 2 and C 6 F 12 O/CO 2 gas mixtures

This study investigates the insulation performance of the new environmental friendly insulation gas C 6 F 12 O mixed with N 2 and CO 2 under the AC frequency voltage under 0.10–0.30 MPa. Firstly, the mixing ratio of C 6 F 12 O in the mixed gas is discussed by the gas phase state equation. The breakdown voltage of C 6 F 12 O 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 SF 6 gas mixtures are compared. The self‐recovery performance of the gas mixture is analysed as well. Experimental results show that the mixing ratio of C 6 F 12 O is lower than 7% under 0.10 MPa, such that the operation requirements of the equipment can be satisfied. The breakdown voltage of 3% C 6 F 12 O gas mixtures is the same as that of 10% SF 6 gas mixtures. The partial discharge inception voltage of 6% C 6 F 12 O gas mixtures is close to that of 10% SF 6 gas mixtures. After 100 times of breakdown, the breakdown voltage of C 6 F 12 O gas mixtures does not decrease. Compared with N 2 , the breakdown voltage of C 6 F 12 O mixed with CO 2 shows a more dispersive trend.