交联聚乙烯电缆绝缘中的水树生长特性  

Water Tree Growth Characteristics in XLPE Power Cable Insulation

作　　者：周凯[1] 黄科荣 黄明 张春烁 李明志 陈泽龙[1] ZHOU Kai;HUANG Kerong;HUANG Ming;ZHANG Chunshuo;LI Mingzhi;CHEN Zelong(College of Electrical Engineering and Information Technology, Sichuan University, Chengdu 610065, China;State Grid Nanchang Power Supply Company, Nanchang 330012, China)

机构地区：[1]四川大学电气信息学院,成都610065 [2]国网南昌供电公司,南昌330012

出　　处：《高电压技术》2019年第10期3207-3213,共7页High Voltage Engineering

基　　金：国家自然科学基金(51477106)~~

摘　　要：为深入理解水树生长特性,将XLPE电缆中的水树生长形态变化与COMSOL模型仿真相结合,研究了水树不同时期的生长特性及发展规律。实验采用水针电极法获取不同老化时期的水树电缆试样,并通过显微镜观察水树的微观形态。基于水树形态变化和生长速率,将水树发展分为3个阶段:初始阶段、滞长阶段、后续阶段,IR和SEM 2种理化分析被用以说明滞长阶段和初始阶段的区别。构建了水树发展3个阶段的COMSOL模型,并通过仿真结果对水树生长变化进行分析和解释。研究表明:水树生长表现为同时存在的--沿电场线方向生长和区域内部加密生长;水树生长3个阶段中,初始阶段水树分支少且发展迅速;滞长阶段由于水树区域的电场变化和水珠变大,水树在沿电场线方向上生长出现减缓,转为水树区域密度变大,形态上逐渐形成扇形区域;后续阶段中,由于电场畸变点的存在,水树再次出现新的分支。滞长阶段和后续阶段会不断交替,直至电缆绝缘完全被桥接。In order to understand the growth characteristics of water tree, by combining the morphological changes of water tree in XLPE cables with COMSOL model simulation, we studied the growth characteristics and development rules of water tree in different periods. Water-needle electrode method was used to obtain cable samples of different ageing stages, and a microscope was used to observe the microscopic morphology. Based on changes in morphology and growth rate of water tree, the development of the ventilated water tree was divided into three stages: initial stage, stagnation stage, and follow-up stage. IR and SEM physicochemical analyses were used to illustrate the difference between the stagnation and initial stages.Moreover, we constructed a COMSOL simulation model of three stages, and analyzed and explained the growth of water trees through the simulation results. The results shows that water tree growth appears to exist simutane- ously-straight growth along the direction of the electric field lines and intra-regional growth. During the three stages, the branches of water trees are few and develop rapidly in the initial stage;in the stagnation stage, for the electric field change in the water tree region and the water droplets becomes larger, the growth rate of water trees slows down along the electric field lines and the density of the water tree becomes larger, gradually forming a fan-shaped area;the water tree forms a new branch again due to the electric field distortion points in the follow-up stage. The stagnation stage and follow-up stage will alternate until the cable insulation is fully bridged.

关 键 词：交联聚乙烯电缆 水树老化 水树生长特性 水树发展3阶段 水树生长模型 

分 类 号：TM247[一般工业技术—材料科学与工程]