温度梯度对热刺激去极化电流测试的影响  

Effect of Temperature Gradient on Thermally Stimulated Depolarization Current Measurement

作　　者：纪哲强[1] 吴建东[1] 兰莉[1] 李喆[1] 尹毅[1] 

机构地区：[1]上海交通大学电气工程系,上海200240

出　　处：《高电压技术》2011年第10期2403-2409,共7页High Voltage Engineering

基　　金：国家自然科学基金(5087704751007057)~~

摘　　要：热刺激去极化电流(TSDC)测试是分析电介质内部电荷输运特性和陷阱能级的重要方法。为了研究并改进热刺激去极化电流测试系统,分别测试了热刺激电流测试系统中两套不同结构电极的电极温度差和其相应的聚酯薄膜热刺激去极化电流,分析了试样温度梯度对测试结果的影响。结果表明上下电极结构的不对称将导致试样受热不均匀,在试样厚度方向产生温度梯度;聚酯薄膜的热刺激去极化电流包含两个明显的峰,分别为α峰与ρ峰;温度梯度对聚酯薄膜中由陷阱电荷引起的ρ峰位置影响较大,而对由偶极子引起的α峰位置影响较小;在一定的温度梯度下,α峰位置并无明显的变化,而ρ峰位置前移至更低温度,并且在极化温度偏高的情况下,可能存在陷阱峰消失的情况,从而影响热刺激电流测试结果的可靠性与分辨率。Thermally stimulated depolarization current（TSDC）was used to determine charge transportation and trap levels in dielectric. To investigate and improve TSDC measuring system, the TSDCs of polyester （PET） film cooperating with two types of electrodes, as well as temperature gradient in both types of electrodes, were measured. The influence of temperature gradient on TSDC was analyzed. Results show that an asymmetric electrode structure can result in a non-uniform heating condition of the specimen, and a significant temperature gradient in specimen. It is found that a complete TSDC curve consists of two distinct peaks named a and ρ peaks, respectively, with the asymmetric electrode structure. It is also found that the temperature gradient has a greater impact on ρ peak which is caused by trapped charge in PET films, while it has less impact on the position of a peak which is caused by dipole. Under certain temperature gradient, the ρ peak will move forward to a lower temperature. However, the position of a peak does not change obviously. It is even possible that the trap peak will disappear when polarization temperature is excessively high, which will influence the resolution and reliability of TSDC measuring result.

关 键 词：热刺激去极化电流(TSDC) 聚酯(PET)薄膜 电极 温度梯度 偶极子 陷阱 

分 类 号：TM855[电气工程—高电压与绝缘技术]