基于太赫兹时域光谱技术的交联聚乙烯电缆绝缘层气隙检测分析  

Air Gap Detection and Analysis of XLPE Cable Insulation Based on Terahertz Time Domain Spectroscopy

作　　者：谢声益 杨帆[1] 黄鑫 余晓 高兵[1] Xie Shengyi;Yang Fan;Huang Xin;Yu Xiao;Gao Bing(State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing University,Chongqing 400044 China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆400044

出　　处：《电工技术学报》2020年第12期2698-2707,共10页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金面上项目(51777023);重庆市研究生科研创新项目(CYB17010)资助。

摘　　要：隐藏气隙缺陷会严重影响交联聚乙烯(XLPE)电缆的绝缘性能,造成安全隐患。该文提出一种基于太赫兹时域光谱技术(THz-TDS)的XLPE无损检测新方法。首先分析XLPE中隐藏气隙缺陷特性,建立含有气隙缺陷的XLPE的多层色散模型并进行理论分析,然后采用实际XLPE样品并人工模拟气隙缺陷,最后利用自己搭建的透射式THz-TDS系统对样品成谱成像实验。实验结果表明,通过采集THz-TDS系统透过样品的时域信号,以信号幅值和相位为特征量可有效辨别XLPE样品的隐藏气隙,对信号谱进一步分析可以得出隐藏气隙的几何尺寸信息,计算误差在2.9%以内;另外,对XLPE隐藏气隙的THz成像实验可以更直观地观测到气隙特征,应用该文设计的太赫兹成像算法能清楚地辨识气隙的位置和形状特性。该文从理论和实验上证明了基于THz-TDS系统对XLPE隐藏气隙缺陷无损检测的新方法的可行性,可为电缆绝缘缺陷的无损检测提供一种新的思路,且可应用于其他电气设备检测中。The implied air gap defects will seriously affect the insulation cross-linked polyethylene(XLPE)and cause potential safety issues.In this paper,a novel nondestructive detection method of XLPE based on terahertz time-domain spectroscopy(THz-TDS)was proposed.The multi-layer dispersion model of XLPE with air gap defects was established and the defect feature of air gap had been investigated carefully.Based on theoretical model,actual XLPE sample was used to simulate the air gap defects artificially.Then the transmission THz-TDS system was employed to carry out the spectral imaging experiments.There sultsshow that obvious difference in both amplitude and phase can be observed by comparing the normal signal with the defect signal.Further analysis of the signal spectrum can obtain the geometric size information of the air gap defect hidden in XLPE,and the calculation error is less than 2.9%.In addition,the characteristics of air gap can be represented more intuitively by THz imaging technique.The terahertz imaging algorithm proposed in this paper can extract the position and shape information of air gap defect conveniently.Through theoretical analysis and experimental verification,this paper proves the feasibility of a new non-destructive testing method based on THz-TDS system for concealed air gap defects in XLPE,which provides a new idea for non-destructive detection of cable insulation defects and can be applied to other electrical equipment detection.

关 键 词：太赫兹时域光谱技术 交联聚乙烯 无损检测 太赫兹成像 

分 类 号：TM247[一般工业技术—材料科学与工程]