运行环境对换流变压器油纸绝缘电场分布的影响  

Electric field analysis of oil-paper insulation in converter transformer under different environmental factors

作　　者：池明赫[1,2,3] 李毅恒 罗青林 张潮海 孙文鑫[1] 关毅 陈庆国 CHI Ming-he;LI Yi-heng;LUO Qing-lin;ZHANG Chao-hai;SUN Wen-xin;GUAN Yi;CHEN Qing-guo(Key Laboratory of Engineering Dielectrics and Its Application,MOE,Harbin University of Science and Technology,Harbin 150080,China;TBEA,Changji 750306,China;School of Electrical Engineering and Automation,Harbin Institute of Technology,Harbin 150006,China)

机构地区：[1]哈尔滨理工大学工程电介质及其应用教育部重点实验室,哈尔滨150080 [2]特变电工股份有限公司,新疆昌吉750306 [3]哈尔滨工业大学电气工程及其自动化学院,哈尔滨150006

出　　处：《电机与控制学报》2021年第5期71-79,共9页Electric Machines and Control

基　　金：国家重点研发计划资助(2017YFB0902704);国家自然科学基金面上项目(51677046&51877056);中国博士后基金(43XB3822XB)。

摘　　要：为研究多环境因素对换流变压器阀侧典型油纸绝缘结构电场分布的影响,在-20℃~80℃以温度和含水率为变量对变压器油和浸油纸板进行电导率和相对介电常数的测量。建立换流变压器阀侧主绝缘模型,利用实测数据建立动态材料属性,通过仿真得到不同温度、含水率在外施电压幅值为800kV的纯交流、83%直流含量、87.5%直流含量以及纯直流条件下的油纸绝缘结构电场分布。研究结果表明:当温度为-20℃或0时浸油纸板电导率随电场强度升高呈先降后升的趋势,而当温度为20℃或80℃时浸油纸板电导率随电场强度呈上升趋势。温度、含水率和外施电压直流含量均会对油纸绝缘电场分布产生影响,最大场强的位置会随外施电压直流分量与浸油纸含水率的变化而改变;运行温度下换流变主绝缘承受的场强高于常温下;水分会使绝缘纸板电导率明显上升甚至高过绝缘油,导致油中场强高于纸板中。In order to study the influence of multiple environmental factors on the electric field distribution of the typical oil-paper insulation structure on the valve side of the converter transformer, the electrical conductivity and relative mediation of transformer oil and oil-impregnated paperboard were measured at-20 ℃-80 ℃ with temperature and moisture as variables. The oil-paper insulated valve side winding model of the converter transformer was established, and the material attribute was assigned as a dynamic value with temperature and moisture according to measured data. Through simulation, the electric field distribution of the oil-paper insulation structure under different temperature, moisture and applied voltage amplitude of 800 kV pure AC, 83% DC content, 87.5% DC content and pure DC conditions are obtained. Research indicates: When the temperature is-20 ℃ or 0, the electrical conductivity of oil-impregnated cardboard decreases first and then rises as the electric field strength increases, and conductivity increases with electric field strength when the temperature is 20 ℃ or 80 ℃. Temperature, moisture and DC content of the applied voltage all affect the electric field distribution of the oil-impregnated paper insulation, and the position of the maximum field strength is changed with the DC content of the applied voltage and the moisture content of the oil-impregnated paper. The field strength of the main insulation of the converter transformer at operating temperature is higher than that at room temperature. Moisture increases conductivity of oil-impregnated cardboard significantly or even higher than the conductivity of the insulating oil, resulting in higher electric field strength in the oil than in the oil-impregnated cardboard.

关 键 词：油纸绝缘 温度 水分 电场分布 动态参数 过渡时间 

分 类 号：TM85[电气工程—高电压与绝缘技术]