变压器油纸绝缘水分的回复电压分析法  

Return Voltage Method of Moisture of Oil-paper Insulation in Power Transformer

作　　者：江修波[1] 黄彦婕[1] 张涛[2] 

机构地区：[1]福州大学电气工程与自动化学院,福州350002 [2]三峡大学电气与新能源学院,宜昌443002

出　　处：《高电压技术》2010年第12期2984-2989,共6页High Voltage Engineering

基　　金：福建省自然科学基金(2010J01283)~~

摘　　要：变压器油纸绝缘系统中的水分会加速其固体绝缘材料的老化,准确诊断变压器固体绝缘中的水分质量分数对确保其安全可靠运行,延缓绝缘老化都具有重要意义。变压器油纸绝缘会因老化或受潮而导致其介电特性发生变化,基于检测油纸绝缘介电特性的回复电压测量方法能有效诊断变压器的油纸绝缘状态,并可用来估测固体绝缘纸板的水分质量分数。为此,通过分析变压器油纸绝缘中水分的极化特性,阐述了回复电压方法诊断固体绝缘水分质量分数的原理;并试验研究了变压器油纸绝缘水分质量分数与回复电压特征量及极化谱之间的关系,其中回复电压主时间常数可以量化固体绝缘的等值水分质量分数,一台220kV变压器试验结果表明回复电压方法能够有效地诊断变压器的绝缘油纸状态。Return voltage measurement based on the dielectric response theory is a non-destructive diagnostic method,which can detect variation of dielectric parameters of insulation material and assess water content in transformer insulation by polarization properties availably.Consequently,the principle of assessing water content by return voltage method in detail is expounded,and an experimental study is conducted to analyze the relation between characteristic quantity of return voltage and moisture in oil-paper insulation transformer.The experimental results are analyzed and show that dominant time constant can be connected with its moisture content.Meanwhile,repairing quality of a transformer with 220kV is verified by the method,showing that the method is effective for diagnosing oil-paper insulation condition of transformer.The influences of polarization spectrum are also researched,and the results show that,at the lower return voltage of transformer,environmental effect is significant.Therefore,it is important to remove all kinds of interference in order to obtain accurate measurement results.

关 键 词：回复电压方法 水分 油纸绝缘 变压器 极化谱 主时间常数 

分 类 号：TM855[电气工程—高电压与绝缘技术]