基于回复电压法的变压器绝缘纸水分及绝缘状态研究  

Research on Moisture Content and Insulation State of Oil-paper for Transformer Based on Return Voltage Measurement

作　　者：尹小兵[1,2] 郝长金 黎成林 曹保江[1] 高波[1] 吴广宁[1] 

机构地区：[1]西南交通大学电气工程学院,成都610031 [2]四川电力设计咨询有限责任公司,成都610041

出　　处：《高压电器》2017年第11期152-158,共7页High Voltage Apparatus

摘　　要：变压器绝缘纸中水分会加速油纸绝缘的老化,缩短变压器寿命,因此,准确诊断变压器绝缘纸老化状态以及水分含量对变压器安全运行具有重要意义。文中通过测试分析不同水分、不同聚合度的绝缘油纸回复电压曲线,研究发现当绝缘纸处于低水分含量状态(0.5%≤Mp<3%)时,回复电压参数随水分含量改变变化较快,当绝缘纸处于高水分含量状态(3%≤Mp≤5%)时,回复电压4个参数值基本保持稳定。回复电压最大值、初始斜率随绝缘纸水分含量呈负指数规律增长,而中心时间常数和回复电压半衰期呈负指数规律减小,4个参数随水分改变的变化幅度均随绝缘纸聚合度线性变化,通过数据拟合得到回复电压特征参量与绝缘纸聚合度、水分含量的表达式。回复电压半衰期与绝缘纸水分含量及老化状态关系密切,能作为反映固体绝缘纸微水含量和聚合度的有效特征参量。To accurately diagnose oil-paper aging state of transformer insulation and detect moisture content of the oil-paper,the return voltage curves of oil-paper samples with different degree of polymerization（Dp）and moisture content were measured.The results show that： 1）when the insulating oil-paper is in a state of low moisture content（0.5%≤Mp〈3%）, four parameters of the return voltage change quickly with moisture content, and when the oilpaper has high mois-ture content （3%≤Mp≤5%）,the four parameters almost keep stable;2）The maximum value and initial slope of the return voltage curve increase with moisture content of oil-paper,while the central time constant and half-life time decrease following negative exponential law;and 3）the variation amplitudes of the four parameters with moisture show a linear relationship with the Dp, and the expression of RVM parameters with Mp and Dp are fit- ted.The half-life time of return voltage curve shows a significant relationship with moisture content and insulation state of oil-paper, so it can be adopted to evaluate the moisture content and Dp of the oil-paper.

关 键 词：油纸绝缘 回复电压 回复电压半衰期 水分含量 聚合度 

分 类 号：TM855[电气工程—高电压与绝缘技术]