运行条件对换流变压器油纸绝缘油流带电特性的影响  

Influence of Operation Conditions on Flow Electrification Characteristics of Oil-paper Insulation in Converter Transformer

作　　者：陈庆国[1] 王金龙[1] 林林[1] 池明赫[1] 魏新劳[1] CHEN Qingguo;WANG Jinlong;LIN Lin;CHI Minghe;WEI Xinlao(Key laboratory of Engineering Dielectrics and Its Application,Harbin University of Science and Technology,Harbin 150080,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

出　　处：《高电压技术》2018年第12期3880-3887,共8页High Voltage Engineering

基　　金：国家自然科学基金(51677046)~~

摘　　要：为揭示运行条件对换流变压器内部油流带电特性的影响规律,在实验室开展了典型平板电极结构下油纸绝缘油流带电特性的研究,并分析了温度、含水率和外施直流电压幅值对冲流电流的影响机理。试验结果表明:无外施电压时,冲流电流随含水率的增加呈减小趋势,随流速和温度的增加呈增大趋势;在外施直流电压下,冲流电流随外施电压幅值和温度的增加呈增大趋势;在低温和低外施电压下冲流电流随含水率的增加呈先增大后减小趋势,而在高温或高外施电压下冲流电流随含水率的增加呈减小趋势。理论分析表明:无外施电压时,温度和含水率通过影响绝缘纸板中离子扩散系数和油侧双电层厚度来影响油流带电特性;外施直流电压会加速绝缘纸板中离子的迁移速度,进而引起低含水率下油纸绝缘中冲流电流的显著提高;冲流电流与油纸绝缘中离子数密度和离子迁移率密切相关,温度及含水率的变化会造成油和纸板中离子数密度和离子迁移率的变化存在较大的差异,进而对油纸绝缘油流带电特性产生影响。In order to reveal the influence of operation conditions on flow electrification characteristics in converter transformer, we researched the flow electrification characteristics of oil-paper insulation with the typical plane electrode structure, and discussed the influence mechanism such as temperature, moisture content and excited DC voltage amplitude on streaming current. The experiment results show that the streaming current decreases as the moisture content decreases in the absence of an excited voltage, and it increases as the temperature and oil flow velocity increase in the absence of an excited voltage. The streaming current increases as the excited voltage amplitude and temperature increase, it increases firstly and then decreases as the moisture content increases at a low temperature and a low excited voltage, and it decreases as the moisture content increases at a high temperature or a high excited voltage. The theoretical analysis shows that, in the absence of an excited voltage, the temperature and moisture content can influence the flow electrification characteristics by affecting the ions diffusion coefficient in the insulation paper and thickness of the electric double layer in oil. The excited DC voltage will accelerate the migration velocity of ions in insulating paper, resulting in the significant increment of streaming current in oil-paper insulation at a low moisture content. Streaming current is closely related to the ions concentration and ions mobility in oil-paper insulation. The flow electrification characteristics of oil-paper insulation will be influenced by the variation of temperature and moisture content via different variations of ions concentration and ions mobility in oil and paper.

关 键 词：油流带电 油纸绝缘 运行条件 换流变压器 离子迁移 

分 类 号：TM855[电气工程—高电压与绝缘技术]