基于时域介电谱和去极化电量的变压器油纸绝缘老化特征量研究  

Study on Aging Characteristics of Transformer Oil-paper Insulation Based on the Time Domain Dielectric Spectroscopy and Depolarization Charge Quantity

作　　者：吴广宁[1] 宋臻杰 杨飞豹 陈明星[1] 高波[1] 

机构地区：[1]西南交通大学电气工程学院,成都610031

出　　处：《高电压技术》2017年第1期195-202,共8页High Voltage Engineering

基　　金：中央高校基本科研业务费专项资金(2682015CX032)~~

摘　　要：为研究变压器油纸绝缘极化/去极化电流法特征量,在130℃下进行了油纸试样的加速热老化试验,测得了试样在不同老化阶段的去极化电流,提出以稳态油老化电量Q_o和稳态油纸界面极化电量Q_(o-p)作为变压器绝缘油与油纸界面极化的老化特征量,并提取绝缘纸时域介电谱峰值和峰值时间tpeak作为绝缘纸老化特征量,最后通过现场试验验证了以上述特征量分别表征油纸绝缘老化状态的可行性。结果表明:Q_o随老化时间的增加而增大,2者间存在线性拟合关系,Q_o可以表征油中偶极子转向极化强度;绝缘纸时域介电谱峰值及对应时间分别代表了其内部因纤维素裂解引起的界面极化强度和响应速度,其中时域介电谱峰值和聚合度之间具有指数负相关关系;Q_(o-p)随老化时间增加而增大,2者间存在线性拟合关系,Q_(o-p)可以表征油纸界面极化强度。In order to study aging characteristics of oil-paper insulation in transformer, we performed accelerated aging test of oil-paper insulation sample under 130℃ and measured polarization/depolarization current of samples in different aging stages. Then, taking the steady oil aging charge quantity Qo and steady oil-paper interfacial polarization charge quantity Qo-p were performed as aging characteristics of transformer oil and oil-paper interfacial polarization. And ex- tracted peak value and peak time Qo of time domain dielectric spectroscopy as aging characteristics of insulation paper. Finally, we verified the feasibility of the above described aging characteristics by field tests. The results show that, Qo in- creases with sample aging days and there is a linear fitting relationship between them. Qo can represent strength of dipole polarization in oil. Extracted peak value and tpeak, can represent the strength and response speed of interracial polarization in paper caused by cellulose cracking. There is exponential negative correlation between extracted peak value and degree of polymerization. Qo-p increases with sample aging days and there is a linear fit relationship between them. Qo-p can rep- resent strength of oil-paper interface polarization.

关 键 词：时域介电谱 去极化电流 油纸绝缘 介电响应 老化特征量 油纸界面极化 

分 类 号：TM855[电气工程—高电压与绝缘技术]