XLPE中金属尖刺缺陷阻性电流谐波成分分析  

Analysis on resistive current harmonic components of metal spike defect in XLPE

作　　者：林奕夫 何锋 赵岩[2] 朱俊伟 郑书生[2] LIN Yifu;HE Feng;ZHAO Yan;ZHU Junwei;ZHENG Shusheng(State Grid Fujian Electric Power Co.,Ltd.,Fuzhou 350007,China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China)

机构地区：[1]国网福建省电力有限公司,福建福州350007 [2]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《绝缘材料》2023年第11期101-109,共9页Insulating Materials

基　　金：国家电网有限公司科技项目(5213202100A5)。

摘　　要：为开发一种能实时掌握电缆绝缘状态的监测技术,本文通过模拟XLPE电缆绝缘中出现金属尖刺缺陷,对其阻性电流的谐波成分进行分析,从理论和实验两方面为实现基于阻性电流谐波成分的电缆绝缘诊断提供支撑。首先,基于聚合物的跳跃电导模型,对XLPE的电导特性进行了仿真与理论分析。而后建立了XLPE金属尖刺缺陷仿真模型,对不同针尖曲率半径以及针板间距下阻性电流密度的谐波成分进行了仿真分析。最后制作了3种不同规格的XLPE金属尖刺缺陷试样,在针尖曲率半径为30μm、针板间距为2 mm,针尖曲率半径为90μm、针板间距为3 mm以及针尖曲率半径为30μm、针板间距为3 mm条件下进行了验证实验。结果表明:当XLPE绝缘中存在导体尖刺缺陷时,由于局部电场强度的急剧增大,导致绝缘材料的电导特性随着交流电压波形的变化而在欧姆区与非欧姆区之间反复,使得阻性电流的波形发生畸变,叠加了高次谐波分量;当XLPE绝缘中存在导体尖刺缺陷时,其阻性电流中会存在明显的3次与5次谐波分量,二者构成了阻性电流谐波分量的主要组成部分;随着导体尖刺缺陷的严重程度增加,阻性电流的谐波畸变率以及电导率畸变率均有明显的上升,可以谐波畸变率作为判断缺陷严重程度的特征量。In order to develop an on-line monitoring technology for cable insulation status,we analyzed the harmonic components of resistive current by simulating the metal spike in XLPE cable insulation,which provided theoretical and experimental support for cable insulation diagnosis based on the harmonic components of resistive current.Firstly,the conductivity characteristics of XLPE were simulated and theoretically analyzed based on the jump conductivity model of polymer.Then,a simulation model of metal spike defect in XLPE was established,and the harmonic components of resistive current density under different needle curvature radius and needle plate spacing were simulated and analyzed.Finally,three kinds of XLPE metal spike defect samples with different specifications were made,and confirmatory experiments were conducted under the conditions of 30μm of needle tip curvature radius and 2 mm of needle plate spacing,90μm of needle tip curvature radius and 3 mm of needle plate spacing,and 30μm of needle tip curvature radius and 3 mm of needle plate spacing.The results show that there is metal spike defect in XLPE insulation,due to the sharp increase of local electric field strength,the conductivity characteristics of the insulation material will repeat between the Ohmic and non Ohmic regions with the change of AC voltage waveform,resulting in the distortion of resistive current waveform and the addition of higherorder harmonic components.When there is metal spike defect in XLPE insulation,there are obvious 3rd and 5th harmonic components in the resistive current,which constitutes the main components of resistive current harmonic component.As the severity of metal spike defect increases,the harmonic distortion rate of resistive current and conductivity distortion rate increase significantly,and the harmonic distortion rate can be used as a characteristic quantity to judge the severity of defect.

关 键 词：XLPE电缆 交流阻性电流 电导率 谐波分析 

分 类 号：TM215[一般工业技术—材料科学与工程]