服役时间对110kV交联聚乙烯电缆绝缘性能和超分子结构的影响  

Effect of Service Time on Properties and Supramolecular Structure of 110 kV XLPE Cable Insulation

作　　者：张成[1] 李洪飞 赵明 高智益[1] 李光[1] 赵洋[1] 任成燕[3] 黄兴溢[2] 江平开[2] ZHANG Cheng;LI Hongfei;ZHAO Ming;GAO Zhiyi;LI Guang;ZHAO Yang;REN Chengyan;HUANG Xingyi;JIANG Pingkai(State Grid Beijing Electric Power Company,Beijing 100022,China;Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing,Shanghai Jiao Tong University,Shanghai 200240,China;Key Laboratory of Power Electronics and Electric Drive,Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]国网北京市电力公司电缆分公司,北京100022 [2]上海交通大学上海市电气绝缘与热老化重点实验室,上海200240 [3]中国科学院电工研究所中国科学院电力电子与电气驱动重点实验室,北京100190

出　　处：《绝缘材料》2020年第8期19-24,共6页Insulating Materials

基　　金：国家电网公司科技项目(52023317000J);中国科学院科研仪器设备研制项目(YJKYYQ20170004)。

摘　　要：交联聚乙烯(XLPE)具有优异的电绝缘性能和力学性能,但XLPE电缆绝缘在长期服役过程中会发生老化,造成供电故障及服役寿命缩短。为研究服役时间对XLPE电缆绝缘性能的影响,本文研究了XLPE电缆绝缘性能和超分子结构随服役时间增加的变化规律,讨论了退役电缆再利用的可能性。结果表明:当服役时间增加到30年时,电缆绝缘的拉伸强度和断裂伸长率分别从23.7 MPa和929%下降到19.0 MPa和832%,但断裂伸长率仍高于国家标准规定,即大于新电缆绝缘的50%;新电缆绝缘的熔点高于服役后的电缆绝缘,服役后XLPE电缆绝缘的熔程变宽,结晶度先升高后下降;随着服役时间的增加,XLPE电缆绝缘的球晶尺寸增大,服役30年的电缆绝缘球晶平均尺寸约为41μm,是新电缆绝缘的4~5倍;经过30年服役,XLPE电缆绝缘的耐击穿性能仍然优异,室温交流击穿强度约为140 kV/mm。Cross-linked polyethylene(XLPE)has excellent insulating properties and mechanical properties,but XLPE cable insulation will be aged during long-term service,resulting in power supply failure and service life reduction.In order to study the influence of service time on the properties of XLPE cable insulation,we studied the change laws of performance and supramolecular structures of XLPE cable insulation with the increase of service time,and discussed the reuse possibility of retired cable.The results show that when the service time increases to 30 years,the tensile strength and elongation at break of the cable insulation decrease from 23.7 MPa and 929%to 19.0 MPa and 832%,respectively,but the elongation at break is still higher than the requirement of national standard,that is,which is more than 50%of new cable insulation.The melting point of the new cable insulation is higher than that of the serviced cable.After service,the melting range of the XLPE cable insulation becomes wider,and the crystallinity increases at first and then decreases.With the increase of service time,The spherocrystal size of XLPE cable insulation increases,and the average spherocrystal size of XLPE cable insulation serviced for 30 years is about 41 mm,which is 4-5 times larger than that of the new XLPE insulation.After 30 years of service,the breakdown resistance of XLPE cable insulation is still excellent,and the AC breakdown strength at room temperature is about 140 kV/mm.

关 键 词：交联聚乙烯 服役时间 性能 超分子结构 

分 类 号：TM215[一般工业技术—材料科学与工程]