绝缘材料热老化对电缆终端接头典型缺陷处电场畸变的影响  

Effect of insulating materials thermal aging on electric field distortion of typical defects in cable terminal joints

作　　者：黄博 杨铭远 聂永杰 赵学童[2] 陈道远 李洪伟 HUANG Bo;YANG Mingyuan;NIE Yongjie;ZHAO Xuetong;CHEN Daoyuan;LI Hongwei(Puer Power Supply Bureau of Yunnan Power Grid Co.,Ltd.,Puer 665000,China;State Key Laboratory of Power Transmission Equipment Technology,School of Electrical Engineering,Chongqing University,Chongqing 400044,China;Electric Power Research Institute of Yunnan Power Grid Co.,Ltd.,Kunming 650217,China)

机构地区：[1]云南电网有限责任公司普洱供电局,云南普洱665000 [2]重庆大学电气工程学院,输变电装备技术全国重点实验室,重庆400044 [3]云南电网有限责任公司电力科学研究院,昆明650217

出　　处：《工程塑料应用》2024年第12期124-132,共9页Engineering Plastics Application

基　　金：云南电网有限责任公司科技项目(YNKJXM20230142);云南电网有限责任公司科技项目(YNKJXM20230147);国家自然科学基金项目(51877016)。

摘　　要：电缆终端接头是电力电缆输电系统的重要组成部分,为了获得绝缘材料老化对电缆终端接头内部缺陷电场强度分布的影响,选用国产10 kV交联聚乙烯(XLPE)电缆及硅橡胶(SIR)冷缩式电缆终端接头开展研究。首先,对电缆终端接头内的绝缘材料XLPE和SIR在150℃条件下进行16 d的热老化,并测试其在老化前后的相对介电常数和电导率。同时,基于COMSOL Multiphysics软件建立了10 kV电缆终端接头的三维仿真模型,根据上述试验结果设置热老化前后的绝缘材料参数,并利用该模型设置了3种典型缺陷,包括外半导电层错位、主绝缘划痕和尖端金属,分析了不同位置和不同尺寸的缺陷在绝缘材料老化状态下的电场强度分布情况。结果表明,XLPE和SIR在热老化处理后相对介电常数分别从2.5和2.85提高到4.4和3.21,且由于绝缘材料的老化,电缆终端接头的内部电场发生明显畸变,特别是在XLPE和SIR界面处电场畸变显著。另外,热老化后的电缆终端接头在3种典型缺陷条件下,电场畸变率明显提高,外半导电层错位、主绝缘划痕和尖端金属缺陷处电场强度最大值分别提高到5.26,3.5,16.91 kV/mm,较未老化状态下提高了17.41%,6.38%和21.83%。绝缘老化加剧了缺陷处的电场畸变程度,进一步影响了电缆运行的安全性和可靠性,增加了电缆发生故障的风险。The cable terminal joint is an essential component of the power cable transmission system.To investigate the effect of insulating material aging on the electric field strength distribution around the internal defects of cable terminal joints,the domestic 10 kV cross-linked polyethylene(XLPE)cable and silicone rubber(SIR)cold-shrinkable cable terminal joint were selected.The XLPE and SIR in the cable terminal joint were firstly thermally aged at 150℃for 16 days,and their relative permittivity and conductivity were tested before and after the aging process.Additionally,a three-dimension simulation model of the 10 kV cable terminal joint was built using the COMSOL Multiphysics software,and the electrical parameters of XLPE and SIR were set based on the aforementioned test results.Three typical defects,such as misalignment of outer semiconductive layer,XLPE main insulation scratches,and sharp-pointed metal were embedded in the simulation model.The electric field strength distribution of the defects with various size and at different positions was analyzed in the aged insulating materials of cable terminal joint.The results show that the relative permittivity of XLPE and SIR increase from 2.5 and 2.85 to 4.4 and 3.21,respectively,after the thermal aging.Meanwhile,the electrical field distortion in the cable terminal joints increases with the aged insulating materials,and specifically,the electrical field distortion at the XLPE and SIR interface is significantly enhanced.Under the three typical defect conditions,the electric field distortion inside the cable terminal joints becomes more noticeable after the thermal aging process,with the maximum electric field strength at the sites of misalignment of outer semiconductive layer,XLPE main insulation scratches,and sharp-pointed metal reaches 5.26,3.5,16.91 kV/mm,respectively,which increases by 17.41%,6.38%,and 21.83%compared to the non-aged state.The study demonstrates that insulating aging exacerbates the electric field distortion at defect sites,further influences the

关 键 词：电缆终端接头 交联聚乙烯电缆 硅橡胶 热老化 典型缺陷 仿真计算 电场强度分布 

分 类 号：TM247[一般工业技术—材料科学与工程]