低密度聚乙烯/乙丙橡胶双层介质的界面空间电荷特性  

Space Charge Property at the Interface in Low Density Polyethylene/Ethylene Propylene Rubber Double-layered Insulation

作　　者：兰莉[1] 吴建东[1] 王雅妮[1] 尹毅[1] 

机构地区：[1]上海交通大学电子信息与电气工程学院,上海市闵行区200240

出　　处：《中国电机工程学报》2015年第5期1266-1272,共7页Proceedings of the CSEE

基　　金：高等学校博士学科点专项科研基金(20120073110019);国家高技术研究发展计划项目(863计划)(2012AA030310)~~

摘　　要：多层介质复合绝缘结构的物理界面往往比介质本体更容易积累空间电荷,进而发生绝缘劣化,因此被认为是绝缘当中的薄弱点。通过对低密度聚乙烯/乙丙橡胶双层介质的高场电导特性和空间电荷分布测试,分析了界面空间电荷的形成机制和影响因素。结果表明:低密度聚乙烯/乙丙橡胶双层介质的界面空间电荷由Maxwell-Wagner(M-W)极化引起的极化电荷和阴极注入的电子电荷共同组成。由于低密度聚乙烯和乙丙橡胶的电导率的电场依赖性不同,导致界面极化电荷的极性和电荷量均随外施电场的升高而变化;阴极注入的电子在外施电场的作用下向阳极迁移,通过界面进入乙丙橡胶中后被其表面的深陷阱捕获,形成负极性界面电荷的积累,导致实际的界面空间电荷特性偏离M-W极化模型的计算值。The physical interfaces in multilayered dielectric insulation have been identified as weak points of the insulation system with a failure probability much higher than that of the bulk insulation. This paper presents the experimental measurement results of the high field conduction characteristic and space charge distribution in low density polyethylene （LDPE）/ethylene propylene rubber （EPR） double-layered insulation. The results show that the space charge at the interface between LDPE and EPR is due to a combined effect of the Maxwell-Wagner polarization charge and injected electrons from the cathode. The polarity and amount of the polarization charge varies with the applied field, because the conductivity of LDPE and EPR has different field dependence. The accumulation of electronic interfacial charge is formed by the injected electrons passing through the interface and trapped by the deep traps at the surface of EPR.

关 键 词：空间电荷 界面 低密度聚乙烯 乙丙橡胶 双层介质 Maxwell-Wagner极化 电荷注入 

分 类 号：TM85[电气工程—高电压与绝缘技术]