循环老化下电缆绝缘介损特征及在线监测修正方法  

Dielectric loss characteristics and online monitoring correction methods of cable insulation under cyclic aging

作　　者：刘刚 李瑞 张圆明 王秀茹 张鹏飞 陈晨 叶桐珲 张东东 LIU Gang;LI Rui;ZHANG Yuanming;WANG Xiuru;ZHANG Pengfei;CHEN Chen;YE Tonghui;ZHANG Dongdong(Suqian Power Supply Branch,State Grid Jiangsu Electric Power Co.,Ltd.,Suqian 223800,China;School of Electric Power Engineering,Nanjing Institute of Technology,Nanjing 211167,China)

机构地区：[1]国网江苏省电力有限公司宿迁供电分公司,江苏宿迁223800 [2]南京工程学院电力工程学院,江苏南京211167

出　　处：《电力科学与技术学报》2025年第1期274-280,共7页Journal of Electric Power Science And Technology

基　　金：国网江苏省电力公司科技项目(J2023101)。

摘　　要：随着电力电子器件在电网中的投入,以及越来越多的非线性负荷的使用,使得系统中的高次谐波水平也在不断提高,高次谐波不仅对设备和材料的行为有负面影响,且对绝缘参数的在线测试结果也存在影响。为此,该文通过理论分析与试验测试的方式,进行循环老化下电缆绝缘介损特征(tan δ)及在线监测修正方法研究,试验测试不同电压下工频1~8倍频率范围内交联聚乙烯电缆老化后的介质损耗因数。研究结果表明:随着老化程度的增加tan δ增大,20次老化处理前期增幅最大,对于50 Hz情况,tan δ从0.009 4增加为0.021 9;tan δ增大程度受到谐波频率和谐波电压的影响,且谐波频率的影响不可忽略。最后根据试验结果,提出电缆绝缘介质损耗因数修正方法,给出50~400 Hz高频下的修正系数。研究成果可用于工频条件下在线介损监测的修正,从而提升电缆老化在线评估的可靠性。With the investment of power electronic devices in the power grid and the increasing use of nonlinear loads,the level of high-order harmonics in the system is constantly improving.High-order harmonics not only have a negative impact on the behavior of equipment and materials but also affect the online testing results of insulation parameters.Therefore,the dielectric loss characteristics(tanδ)of cable insulation under cyclic aging and online monitoring correction methods are studied through theoretical analysis and experimental testing.The dielectric loss factor of cross-linked polyethylene cables after aging in the frequency range of 1‒8 times the power frequency under different voltages is tested.The research results indicate that as the degree of aging increases,the tanδvalue increases,with the largest increase observed in the early stage of 20 aging treatments.For the 50 Hz condition,the tanδvalue increases from 0.0094 to 0.0219.The degree of increase in tanδis influenced by harmonic frequency and harmonic voltage,and the influence of harmonic frequency cannot be ignored.Based on the experimental results,a method for correcting the dielectric loss factor of cable insulation is proposed,providing correction factors at high frequencies of 50‒400 Hz.The research results can be used for correcting online dielectric loss monitoring under power frequency conditions,thereby improving the reliability of online evaluation of cable aging.

关 键 词：电缆老化 介质损耗因数 高次谐波 修正方法 

分 类 号：TM216[一般工业技术—材料科学与工程]