C4F7N/CO2混合气体对局部不均匀电场的敏感特性  

Sensitivity of C4F7N/CO2 Gas Mixture to Partial Inhomogeneous Electric Field

作　　者：颜湘莲 郑宇 黄河 杨圆 周文俊[2] 柏长宇 Yan Xianglian;Zheng Yu;Huang He;Yang Yuan;Zhou Wenjun;Bai Changyu(China Electric Power Research Institute,Beiing 100192 China;School of Electrical Engineering and Automation Wuhan University,Wuhan 430072 China;Pinggao Group Co.Ltd,Pingdingshan 467001 China)

机构地区：[1]中国电力科学研究院有限公司,北京100192 [2]武汉大学电气与自动化学院,武汉430072 [3]平高集团有限公司,平顶山467001

出　　处：《电工技术学报》2020年第1期43-51,共9页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划（2017YFB0902500）;国家电网公司科技项目“环保型管道输电关键技术”资助

摘　　要：电亲和性气体的放电电压对不均匀电场分布较敏感,高压电气设备电极表面存在的表面粗糙度效应会凸显,从而降低气体绝缘性能。C4F7N/CO2混合气体是一种有潜力的SF6替代气体,有必要研究C4F7N/CO2对不均匀电场分布的敏感特性。该文从理论上分析电极表面粗糙引起的局部电场畸变,计算电场畸变程度对C4F7N/CO2绝缘性能的影响,提出采用优异值来评估C4F7N/CO2混合气体对不均匀电场的耐受能力。与SF6气体对比,发现C4F7N/CO2的优异值随C4F7N含量的降低而增大;当C4F7N体积分数低于20%时,C4F7N/CO2混合气体的优异值比SF6气体的优异值大。为验证计算结果,制作粗糙电极放电模型进行C4F7N/CO2混合气体和SF6气体的放电试验,获得了C4F7N/CO2混合气体和SF6气体的优异值,与计算结果接近。若采用C4F7N/CO2混合气体的设备具有与采用SF6气体相同的绝缘性能时,分析表明当C4F7N体积分数为4%~20%范围时,SF6气体绝缘设备中电极表面粗糙度控制值6.3μm的标准适用于C4F7N/CO2混合气体设备。The discharge characteristics of electron-attaching gases are sensitive to non-uniform electric field.However,it is difficult to make the electrode surface completely smooth in high-voltage electrical equipment.The effect of surface roughness of electrodes is prominent when the pressure is.high,thus reducing the gas insulation performance.C4FzN/CO2 gas mixture is a potential alternative gas to SF6.It is necessary to investigate the sensitivity of C4FzN/CO2 to inhomogeneous electric field distribution.In this paper,the local electric field distortion caused by rough electrode surface is analyzed theoretically,and the influence of electric field distortion on the insulation performance of C4F7N/CO2 is calculated.The figure of merit is proposed to evaluate the tolerance of C4F7N/CO2 gas mixture to inhomogeneous electric field.Compared with SF6,when the content of C4FzN is less than 20%,the figure of merit of C4F7N/CO2 mixture is higher than that of SF6,which increases with the content of C4F7N decreasing.In order to verify the calculation results,a rough electrode discharge model was developed.The discharge tests of C4F7N/CO2 and SF6 gases were carried out.The figures of merit of C4F7N/CO2 with 10%C4F7N content and SF6 gases were obtained,which were close to the calculation results.Based on the figures of merit of C4F7N/CO2 gas mixture,and considering the controlling requirement of electrode surface roughness in C4F7N/CO2 gas mixture equipment with the same insulation performance as that of SF6,it shows that as the content of C4F7N is in the range of 4%~20%,the controlling requirement of electrode surface roughness of 6.3μm in SF6 equipment is suitable for the design of C4F7N/CO2 equipment.

关 键 词：C4F7N/CO2混合气体 SF6 气体 电极表面粗糙度 气体放电 优异值 

分 类 号：TM56[电气工程—电器]