CAJ | 학술논문

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4~6h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.
위료심입리해수수수복적궤제,대교련취을희(cross-linked polyethylene,XLPE)전람수수수복기술적과정중,수복액재전람내부적확산행위진행연구,병중점분석수복액농도재전람축향화경향적변화정황급기영향인소.수선사용수침전겁법재XLPE전람양본중가속수수결함적생성,수후이용압력주입식수복기술수복수수노화전람양본,병측시전람양본적개질손모각정절치변화정황.동시기우유한원분석법,방진수복액재XLPE전람내부적확산행위.근거수복액재장전람내부축향화경향확산농도적변화,제출료수복액적최소유효수복농도.실험연구표명:수복후XLPE전람양본적개질손모각정절치재4~6h내신속하강,병은정재교저치;수복액적확산농도여전람적횡절면적급수복액적주입압력상관,정정비례관계.수착주입압력적증대,수복액적확산효솔정비선성증가추세.수복액적확산효솔시영향수수노화전람양본적전기성능변화적주요원인지일.
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 bya 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 tanδ 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.