用于评估油纸绝缘热老化状态的极化/去极化电流特征参量  

Characteristic Parameters for Assessing Aging Condition of Oil-paper Insulation by Polarization/Depolarization Current

作　　者：杨雁[1] 杨丽君[2] 徐积全[2] 吴高林[1] 徐瑞林[1] 郝建[2] 

机构地区：[1]重庆市电力公司电力科学研究院,重庆401123 [2]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高电压技术》2013年第2期336-341,共6页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724505-1);国家"111"计划(B08036)~~

摘　　要：极化/去极化电流法能灵敏反映介质的绝缘状态,已被应用于变压器油纸绝缘的水分评估中,但通过该方法定量分析油纸绝缘的老化状态尚未见研究报道。为此,对油纸绝缘开展了110°C加速热老化试验,测量了不同老化时间下油纸绝缘样品的极化/去极化电流。通过分析极化/去极化电流特性的变化,提出了一种反映油纸绝缘热老化状态的新特征参量—去极化电量。研究结果表明,试品的去极化电流随老化程度加深不断增大,但其增大趋势微弱,而提出的去极化电量曲线则对试品绝缘老化状态反应极为敏感,且从该曲线中提取的系数A和最大值C这2个特征参量与绝缘纸聚合度满足一阶动力学模型关系式,可以用作评估油纸绝缘热老化程度的特征参量。The polarization and depolarization current（PDC） method is effective in reflecting dielectric material＇s insulation condition,thus it is widely used in evaluating the moisture contents in the oil-paper insulation of transformers.However,the method is seldom reported to be used for quantitatively estimating the aging condition of oil-paper insulations.Therefore,we investigated the PDC characteristics of oil-paper insulation samples in accelerated aging periods at 110°C.Meanwhile,a new characteristic parameter,depolarization charge quantity,was proposed for assessing the aging condition of oil-paper insulation.Results show that the depolarization current increases slowly with developing aging,while the proposed depolarization charge quantity is sensitive to the aging degree of oil-paper insulation.Furthermore,two characteristic parameters,namely,the pre-exponential factor A and the maximum value C,were extracted from the curve of depolarization charge,which satisfied the 1st order kinetic model equation with the degree of polymerization（DP） of paper insulation;so the proposed depolarization charge curve,as well as the two extracted characteristics could be used to predict the aging condition of oil-paper insulation.

关 键 词：变压器 油纸绝缘 老化 极化 去极化电流(PDC) 去极化电量 动力学模型 

分 类 号：TM855[电气工程—高电压与绝缘技术]