修复液的扩散行为对水树电缆修复后电气性能的影响机制  

Effects of Diffusion Activity of Injected Liquid on Water-treeing Cables' Electrical Properties After Injection

作　　者：周凯[1] 杨滴[1] 陶文彪[1] 杨明亮[1] 刘曦[2] 

机构地区：[1]四川大学电气信息学院,四川省成都市610065 [2]国网四川省电力公司电力科学研究院,四川省成都市610065

出　　处：《中国电机工程学报》2015年第19期5095-5102,共8页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51477106)~~

摘　　要：为了深入理解水树修复的机制,对交联聚乙烯（cross-linked polyethylene,XLPE）电缆水树修复技术的过程中,修复液在电缆内部的扩散行为进行研究,并重点分析修复液浓度在电缆轴向和径向的变化情况及其影响因素。首先使用水针电极法在XLPE电缆样本中加速水树缺陷的生成,随后利用压力注入式修复技术修复水树老化电缆样本,并测试电缆样本的介质损耗角正切值变化情况。同时基于有限元分析法,仿真修复液在XLPE电缆内部的扩散行为。根据修复液在长电缆内部轴向和径向扩散浓度的变化,提出了修复液的最小有效修复浓度。实验研究表明：修复后XLPE电缆样本的介质损耗角正切值在4~6 h内迅速下降,并稳定在较低值;修复液的扩散浓度与电缆的横截面积及修复液的注入压力相关,呈正比例关系。随着注入压力的增大,修复液的扩散效率呈非线性增加趋势。修复液的扩散效率是影响水树老化电缆样本的电气性能变化的主要原因之一。In order to further understand the rejuvenation mechanism of water tree in cross-linked polyethylene （XLPE） cables, the diffusion activity of rejuvenation liquid in a XLPE cable was investigated in the process of the water-treeing rejuvenation. The diffusion activity of rejuvenation liquid was also analyzed along axial and radial direction in the XLPE cable, and influence factors of the changes of the rejuvenation liquid concentration were discussed in this paper. Firstly, needle-shape defects were previously made inside XLPE cable samples to create water tree in the XLPE layer. The water tree cables were injected with the rejuvenation liquid, and the dielectric loss factor was measured in the process of the rejuvenation. Moreover, the diffusion activity of rejuvenation liquid in the cables was simulated and analyzed by a finite element method. According to the investigation of the diffusion activity of the rejuvenation liquid in the XLPE cable, the minimum effective concentration of rejuvenation liquid is presented. The results indicate that a sharp decline of tan5 values is observed in 4-6 hours and gradually returns to a lower level after injection. The concentration of the rejuvenation liquid is proportional to the cross-sections of cables and the injection pressure. The diffusion efficiency of the rejuvenation liquid non-linearly increases with the injection pressure increasing. Therefore, the diffusion efficiency of the repair liquid is one of the main reasons for electrical properties changes of the water-treeing cable samples.

关 键 词：交联聚乙烯电缆 水树 修复 分子扩散 介质损耗因素 注入压力 

分 类 号：TM85[电气工程—高电压与绝缘技术]