基于正交匹配-伪魏格纳分布的电缆缺陷定位  

Cable Defect Location Based on Orthogonal Matching Pursuit and Pseudo Wigner-Ville Distribution

作　　者：操雅婷 周凯[1] 孟鹏飞 金宇 王昱皓 Cao Yating;Zhou Kai;Meng Pengfei;Jin Yu;Wang Yuhao(College of Electrical Engineering Sichuan University,Chengdu 610065 China;Kunming Power Supply Bureau Yunnan Power Grid Co.Ltd,Kunming 650000 China)

机构地区：[1]四川大学电气工程学院,成都610065 [2]云南电网有限公司昆明供电局,昆明650000

出　　处：《电工技术学报》2023年第16期4489-4498,共10页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51477106,52107158);四川省科技厅应用基础研究计划(2021YJ0538)资助项目。

摘　　要：时频域反射法(TFDR)采用时频联合的方法对电缆缺陷进行定位,但定位信号时频谱中存在交叉项干扰,导致无法对电缆局部缺陷进行精确定位。该文提出采用正交匹配追踪(OMP)和伪魏格纳分布(PWVD)结合的算法,实现了对实测电缆定位信号特征提取,以及信号时频谱中交叉项干扰抑制。首先通过OMP算法对原信号进行分解;然后对分解后的子信号分别求取PWVD时频分布;最后通过对时频谱线性叠加,获得定位信号更精确的时频表达,有效地消除了交叉项干扰。搭建了10 kV交联聚乙烯电缆仿真模型进行研究,并选取了长度40 m含两个中间接头、105 m含缺陷及500 m含中间接头的XLPE电缆对算法进行实验验证。仿真及实验结果表明,OMP-PWVD改进算法能有效抑制交叉项干扰,且具有较强抗干扰能力,有效地提高了时频域反射法的定位精度。The time-frequency domain reflection method(TFDR)uses the time-frequency joint method to locate the defects,and the traditional time-frequency analysis method is used to obtain the location signal.There is cross-term interference in the time spectrum,resulting in interference peaks in the final positioning curve,which can not accurately locate the local defects of the cable.The orthogonal matching pursuit(OMP)algorithm is proposed to reconstruct the acquired superimposed signal,and the pseudo-Wegner distribution(PWVD)algorithm is used to obtain the time-frequency distribution of the reconstructed sub-signal,so as to obtain the optimal feature distribution in the time-frequency domain of the signal,so as to achieve the feature extraction of the measured cable positioning signal and the suppression of cross-term interference in the signal time-frequency spectrum.Firstly,the Gaussian envelope linear frequency modulation signal is used as the incident signal,and the reflected superimposed signal is obtained according to the transfer function of the single defect cable model.Because the traditional time-frequency domain reflection method uses Wigner distribution(WVD)to calculate the time-frequency spectrum of superimposed signals,the Wigner distribution is no longer an ideal banded impulse function,and the cross terms are more complex.To solve this problem,the OMP algorithm is used to decompose the original superimposed signal,and the PWVD time-frequency distribution is obtained for the decomposed sub-signals;Then the time-frequency spectrum of the obtained sub-signal is linearly superimposed to obtain a more accurate time-frequency expression of the positioning signal,so as to eliminate the cross-term interference;Finally,time-frequency cross-correlation function(TFCC)is used to accurately locate the defect location.The power cable defect model with a total length of 800 m and defects at 300 m is simulated.The OMP-WVD,OMP-PWVD and OMP-SPWVD algorithms are used to process the data respectively.The positioning results

关 键 词：电缆缺陷定位 时频域反射法 交叉项 正交匹配追踪 伪魏格纳分布 

分 类 号：TM76[电气工程—电力系统及自动化]