摘要
变压器油纸绝缘在长期服役过程中,受温度、电场、与机械应力的作用会发生老化,改变其极化特性并影响其绝缘寿命。首先对0~1000h老化（140℃）的油纸绝缘试样进行热刺激电流测试（thermally stimulated current,TSC）,并利用全曲线法获得了各TSC峰的特征参数。其后结合TSC特征参数及微水与酸值测试结果,分析老化对油纸绝缘极化特性的影响。发现老化产物中的水、有机酸和杂质分子会导致油纸绝缘偶极子极化强度上升;纤维素的劣化会导致油纸绝缘界面极化效应增强;老化产物中的水和有机酸会引入大量载流子,降低电导势垒,增大油纸绝缘的电导。该文可深化对油纸绝缘极化特性和其相应机理的理解,并对电力变压器绝缘设计提供参考。
Oil impregnated paper in power transformers deteriorates in long term operation under the effect of temperature, electric field, and mechanical stress. In this paper, thermally stimulated current（TSC） tests were performed on 0-1000 h aged（140℃） oil impregnated paper samples, the charactering parameters of TSC peaks were obtained through a designed Matlab program. The polarization characteristics of aged oil impregnated paper were investigated through a joint analysis of moisture, acidity and the charactering parameters. It was found that dipole polarization is strengthened as a result of generated moisture and acid. The interfacial polarization between transformer oil and insulating paper is strengthened as a result of deterioration of cellulose in insulating paper. The electric conduction is enhanced during the aging process, as multiple charge carriers are generated by the aging byproducts. This investigation could provide further understanding on dielectric characteristics of aged oil impregnated paper insulation, and may benefit the insulation design in power transformers.
作者
朱远惟
崔惠泽
李世军
王辉
景钰
闵道敏
李盛涛
ZHU Yuanwei;CUI Huize;LI Shijun;WANG Hui;JING Yu;MIN Daomin;LI Shengtao(State Key Laboratory of Electrical Insulation and Power Equipment （ Xi＇an Jiaotong University）, Xi＇an 710049, Shaanxi Province, China;States Grid Shaanxi Economic Research Institute, Xi＇an 710065, Shaanxi Province, China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2018年第8期2513-2520,共8页
Proceedings of the CSEE
基金
国家重点基础研究发展计划项目(973项目)(2011CB 209404)
国家电网陕西省电力公司项目(5226JY160008)~~
关键词
油纸绝缘
热老化
热刺激电流
极化
水分
酸值
oil impregnated paper
thermal aging
thermally stimulated current
polarization
moisture
acidity
