Research on the Power Frequency Breakdown Characteristics of C4F7N/CO2/O2 Gas Mixture under Typical Electric Fields
Yang Yuan1,2,3, Gao Keli2,3, Yuan Shuai2, Yan Xianglian2, Bi Jiangang2
1. School of Electrical Engineering and Automation Hefei University of Technology Hefei 230009 China; 2. China Electric Power Research Institute Beijing 100192 China; 3. State key Laboratory of Power Grid Environmental Protection Wuhan 430074 China
Abstract：Studies have shown that O2 can inhibit the decomposition of C4F7N/CO2 gas mixture, thereby improving the reliability of the gas engineering applications, however, there are few studies on the insulation characteristics of C4F7N/CO2/O2 gas mixture. To evaluate the influence of O2 on the power frequency insulation characteristics of C4F7N/CO2 gas mixture, a breakdown test platform was established in this paper, and the power frequency breakdown voltage under typical operating gas pressure, oxygen content and electric field form was obtained. The results show that with the increase of air pressure, the breakdown voltage of C4F7N/CO2/O2 gas mixture under the quasi uniform electric field with 1 mm gas gap is almost linearly increased, while it shows a certain saturation growth trend under slightly and extremely uneven electric fields, and the breakdown voltage shows a N-type variation law under the extremely uneven electric field with 6 mm gas gap. The breakdown voltage of C4F7N/CO2/O2 gas mixture is sensitive to the extremely uneven electric field at high air pressure and long gas gap, the breakdown voltage of 6 mm gas gap under extremely uneven electric field is close to that of 1 mm gas gap under slightly uneven field at 0.45MPa and above. O2 has a certain negative impact on the breakdown voltage under certain air pressure and oxygen content, when 4%, 2%, 8%, 4%, 8% and 8% volume fraction of O2 were added at 0.15MPa to 0.65MPa, the power frequency breakdown voltage decreases by only 6.2% at most. From the perspective of power frequency insulation design and improvement of gas chemical stability, adding 2% to 8% volume fraction O2 is a feasible ternary gas mixture solution.
杨圆, 高克利, 袁帅, 颜湘莲, 毕建刚. 典型电场下C4F7N/CO2/O2混合气体工频击穿特性研究[J]. 电工技术学报, 2022, 37(15): 3913-3922.
Yang Yuan, Gao Keli, Yuan Shuai, Yan Xianglian, Bi Jiangang. Research on the Power Frequency Breakdown Characteristics of C4F7N/CO2/O2 Gas Mixture under Typical Electric Fields. Transactions of China Electrotechnical Society, 2022, 37(15): 3913-3922.
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2022, Vol. 37 
