马一力 丛祥旭 李忠华

摘 要：交联聚乙烯材料在电力电缆中有着广泛的应用，且电树枝生长特性是绝缘可靠性研究的重要基础。针对交联聚乙烯电缆的轻负荷及低温运行条件，设计了一套可多试样同时进行电树枝实验的电极装置，研究了温度对电树枝引发和生长特性的影响。在0～-50℃范围进行了不同温度下的电树枝实验并与+25℃时进行对照，结果表明：温度对电树枝的引发、生長速度和电树枝形貌有着重要影响。电树枝50%起始电压随温度的降低而升高，且温度越低其增加幅度越小；低温对电树枝生长速度有抑制作用，且温度越低越明显；低温环境下的电树枝存在两种典型形貌，且电树枝的起始位置也有别于+25℃。

关键词：

交联聚乙烯；电树枝；温度；50%起始电压；生长速度

DOI：10.15938/j.jhust.2018.03.019

中图分类号： TM85

文献标志码： A

文章编号： 1007-2683（2018）03-0111-06

Growth Behaviors of Electrical Tree in Cross-linked Polyethylene from 0℃ to -50℃

MA Yi-li， CONG Xiang-xu， LI Zhong-hua

（Key Laboratory of Engineering Dielectric and Its Application， Institute of Electrical and Electronic Engineering， Harbin University of Science and Technology， Harbin 150080， China）

Abstract：Cross-linked polyethylene has been widely used in the power cable， and the growth of electrical tree is significant foundations in the researching of insulation reliability. Considering the situation that Cross-linked polyethylene cable worked in the condition of light load and low temperature in extreme weather， a set of electrode device that multiple samples can be tested at a time was used in the experimental system in order to research the initiation and the growing behaviors of electrical tree in cross-linked polyethylene under different temperatures. The experiments of electrical tree were carried out under different temperatures from 0℃ to -50℃， and used the one under +25℃ as the comparison， it showed that temperature had a significant impact on the initiation、growth speed and the typical morphology of electrical tree. As the falling of temperature， the 50% initiation voltage increased obviously， and the increasing range was getting smaller as the temperature getting lower. The low temperature had some inhibitory impacts on the growth speed of electrical tree， and the lower temperature， the more obvious effect. There were two particular types of morphology in low temperature environment， and the growth site of electrical tree was different from the one growing in +25℃.

Keywords：cross-linked polyethylene； electrical trees； temperature； 50% initiation voltage； growth speed

0 引 言

凭借着良好的电气性能和耐热性能[1]交联聚乙烯电缆在电网中有着越来越广泛的应用，同时电树枝生长特性对交联聚乙烯绝缘寿命有着重要的影响[2-3]，因此对交联聚乙烯电树枝生长特性研究具有着重要的意义[4-6]。

国内外学者对交联聚乙烯电树枝生长机理进行了很多研究，J.V. Champion等将空间电荷和固体绝缘中的电树枝现象一并进行了研究[7-9]，实验证实空间电荷的抽出和注入对电树枝的形成有着及其重要的作用，然而部分学者认为低温下机械冷缩应力起主要作用[10-11]。目前为止，国内外学者对室温及高温环境下[14]的不同试验条件如……