Fluorinated nitrile (C4F7N) 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 C4F7N–CO2–O2 gas mixture. The authors found that the dielectric strength of the C4F7N–CO2–O2 gas mixture with 2, 4, 6, 8 and 10% O2 was increased by 4.85%, 6.49%, 7.70%, 3.21% and 2.74% compared with C4F7N–CO2. The addition of 2–6% O2 to the C4F7N–CO2 gas mixture could effectively reduce the content of most of the decomposition by-products such as CF4, CO, C2F6, C3F6, C3F8, CF3CN, C2F5CN, (CN)2. While high content of oxygen (>6%) results in higher decomposition of C4F7N, which has a negative effect on the stability of C4F7N gas mixture. Generally, it is recommended to add 2–6% O2 in the C4F7N–CO2 gas mixture to improve its insulation properties as well as inhibit the decomposition of C4F7N in the discharge for medium-voltage engineering application.

中文翻译：

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O2的规律对中压设备C4F7N-CO2-O2混合气介电及分解性能的影响

氟化腈（C4F7N）气体混合物已被引入，最有希望替代气体绝缘设备中使用的六氟化硫。在这项研究中，作者探索了氧气对C4F7N–CO2–O2混合气体的介电和分解特性的影响。作者发现，与C4F7N–CO2相比，具有2、4、6、8和10％O2的C4F7N–CO2–O2气体混合物的介电强度分别提高了4.85％，6.49％，7.70％，3.21％和2.74％。 。在C4F7N-CO2气体混合物中添加2–6％的O2可有效降低大多数分解副产物的含量，例如CF4，CO，C2F6，C3F6，C3F8，CF3CN，C2F5CN，（CN）2。较高的氧气含量（> 6％）会导致C4F7N分解的增加，这对C4F7N气体混合物的稳定性有负面影响。通常，