SF6变压器中悬浮电位放电分解气体的生成规律  

Decomposed Gases Generated by Partial Discharges at Floating Potential Defects in SF6 Gas Transformers

作　　者：马晨曦 乔胜亚 周文俊[1] 郑宇 喻剑辉[1] MA Chenxi;QIAO Shengya;ZHOU Wenjun;ZHENG Yu;YU Jianhui(School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China;Guangzhou Power Supply Bureau of Guangdong Power Grid Co.,Ltd.,Guangzhou 510410,China)

机构地区：[1]武汉大学电气与自动化学院,武汉430072 [2]广东电网有限责任公司广州供电局,广州510410

出　　处：《高电压技术》2020年第11期4052-4060,共9页High Voltage Engineering

摘　　要：为研究气体绝缘变压器中SF6在局部放电下的分解特性,建立了SF6分解试验平台,设计了变压器绕组缩比模型及由金属颗粒堆积引起的悬浮电位缺陷模型,分别在不同外施电压以及含水量下进行放电分解试验。试验结果表明,在340~1 500 p C的低强度局部放电试验中,典型分解产物有SO2F2、SOF2、CO和CF4,其产气速率关系为:SOF2>SO2F2>CO>CF4。SOF2与SO2F2体积分数的比值φ(SOF2)/φ(SO2F2)随时间增长而趋于稳定且放电强度越强,稳定值越小。此外在过量水分的环境下(体积分数为2 143×10^-6、4 000×10^-6),水分会加速局部放电的发展,同时促进SO2的生成。因此可以利用典型分解产物的种类、体积分数变化规律作为判断局部放电强度的特征量。In order to study the decomposition characteristics of SF6 under partial discharges in SF6 gas insulation transformers,an experimental platform which consists of a transformer winding and the reduced-scale model of floating potential defects was constructed.Partial discharge tests were carried out under different test voltages and moisture levels.The results show that in the low-intensity partial discharge tests of 340~1 500 pC,the typical decomposition products are SO2F2,SOF2,CO and CF4,among which the formation rate is in the order SOF2>SO2F2>CO>CF4.The ratio of the volume fraction of SOF2 to that of SO2F2 tends to be stable with time,and the stronger is the discharge intensity,the smaller the stability will be.In the environment of excessive moisture(volume fraction is 2 143×10^-6 and 4 000×10^-6),the development of partial discharge is faster which promotes the generation of SO2.Therefore,the type of typical decomposition products and the variation law of volume fraction can be used to assess the strength of partial discharge.

关 键 词：气体绝缘变压器 SF6 局部放电 水分 分解特性 

分 类 号：TM40[电气工程—电器] TM855