摘要
Fluorinated nitrile(C_(4)F_(7)N)gas mixture has been introduced as the most promising candidate to replace sulfur hexafluoride using in gas-insulated equipment.In this study,the authors explored the influence of oxygen on the dielectric and decomposition properties of C_(4)F_(7)N–CO_(2)–O_(2)gas mixture.The authors found that the dielectric strength of the C_(4)F_(7)N–CO_(2)–O_(2)gas mixture with 2,4,6,8 and 10%O_(2)was increased by 4.85%,6.49%,7.70%,3.21%and 2.74%compared with C_(4)F_(7)N–CO_(2).The addition of 2–6%O_(2)to the C_(4)F_(7)N–CO_(2)gas mixture could effectively reduce the content of most of the decomposition byproducts such as CF4,CO,C_(2)F_(6),C_(3)F_(6),C_(3)F_(8),CF_(3)CN,C_(2)F_(5)CN,(CN)2.While high content of oxygen(>6%)results in higher decomposition of C_(4)F_(7)N,which has a negative effect on the stability of C_(4)F_(7)N gas mixture.Generally,it is recommended to add 2–6%O_(2)in the C_(4)F_(7)N–CO_(2)gas mixture to improve its insulation properties as well as inhibit the decomposition of C_(4)F_(7)N in the discharge for medium-voltage engineering application.
基金
National Natural Science Foundation of China(No.51707137,51877157)
The first author also acknowledges the financial support from the China Scholarship Council(No.201906270122).
