基于热重和拉伸实验的XLPE电缆绝缘热老化状态分析及机理研究  

Aging Performance and Mechanism of XLPE Cable Insulation Based on Thermogravimetric and Tensile Tests

作　　者：景钰 常彩霞 张婧俣 朱远惟 JING Yu;CHANG Caixia;ZHANG Jingyu;ZHU Yuanwei(State Grid Shaanxi Electric Power Company Economic Research Institute,Xi’an 710075,Shaanxi,China;Lintong Branch,Xi’an Power Supply Company,State Grid Shaanxi Electric Power Company,Xi’an 710600,Shaanxi,China;Frontier Institute of Science and Technology,State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China)

机构地区：[1]国网陕西省电力公司经济技术研究院,陕西西安710075 [2]国网陕西省电力公司西安供电公司临潼分公司,陕西西安710600 [3]西安交通大学前沿科学技术研究院电力设备电气绝缘国家重点实验室,陕西西安710049

出　　处：《电网与清洁能源》2019年第8期16-24,共9页Power System and Clean Energy

基　　金：中国博士后面上基金项目(2018M643648);陕西省自然科学基础研究计划面上基金项目(2019JQ-070)~~

摘　　要：工况下交联聚乙烯电缆绝缘材料的老化会导致其较预期相对较早达到寿命终点,威胁输电系统的可靠运行。采用热老化来模拟工况环境下电缆的老化过程,选取100℃、120℃和140℃和160℃4个不同的老化温度,在每个温度点选取6个老化阶段,研究不同老化温度和老化时间对XLPE电缆绝缘试样性能的影响。通过热重和拉伸测试研究电缆的热性能、机械性能及其结构随老化程度的变化,得到电缆绝缘试样的热老化活化能、起始分解温度、最快分解温度、终止分解温度、断裂伸长率和拉伸强度等参数。研究结果表明:活化能、起始分解温度、最快分解温度和断裂伸长率对电缆老化状态较为敏感;随着老化温度从100℃增加到160℃,这些参数均呈现先略微增大后迅速减小的趋势,说明XLPE电缆绝缘材料热老化在低温范围以结晶作用为主,而在高温范围以热裂解为主。Under operation conditions,aging of crosslinked polyethylene(XLPE)cable insulation causes it to reach the end of lifetime earlier than expected,which threatens the safe and reliable operation of power transmission systems.In this paper,accelerated thermal aging was performed to simulate the actual aging process of power cables under operation.Four different aging temperatures of 100℃,120℃,140℃,and 160℃with six aging durations at each aging temperature were selected.Through thermogravimetric and tensile tests,thermal,mechanical and structural properties of the aged XLPE cables were investigated at each aging stage.Parameters such as activation energy,initial decomposition temperature,fastest decomposition temperature,termination decomposition temperature,elongation at break and tensile strength of the XLPE insulation samples were obtained.It is found that the activation energy,initial decomposition temperature,fastest decomposition temperature,and elongation at break are sensitive to aging statues of XLPE cable insulation.As the aging temperature increased from 100℃to 160℃,all of these parameters first increase and then decrease rapidly.These trends indicate that thermal aging of XLPE cable insulation is mainly caused by crystallization in low temperature region and by thermal cracking in high temperature region.

关 键 词：交联聚乙烯电缆 绝缘老化 热重 

分 类 号：TM215.1[一般工业技术—材料科学与工程]