地铁直流牵引网特殊负荷电流波形识别研究  

Research on identification for special load current waveform in a metro traction network

作　　者：田行军 王楠清 杜明跃 张静 孙学磊 谭子航 杨晓煊 Tian Xingjun;Wang Nanqing;Du Mingyue;Zhang Jing;Sun Xuelei;Tan Zihang;Yang Xiaoxuan(School of Electrical and Electronic Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;R&D Department of Tianjin Keyvia Electric Co.,Ltd.,Tianjin 300392,China)

机构地区：[1]石家庄铁道大学电气与电子工程学院,石家庄050043 [2]天津凯发电气股份有限公司研发部,天津300392

出　　处：《国外电子测量技术》2022年第12期112-119,共8页Foreign Electronic Measurement Technology

基　　金：天津凯发电气股份有限公司重点科技项目(50200010886)资助。

摘　　要：直流牵引网是为地铁车辆提供电能的唯一供电线路,但车辆变速时诱发的特殊负荷电流极易引起馈线保护误动,因而需要引入更有效的特征提取方法来识别出特殊负荷电流。分形维数能敏锐感知直流牵引网馈线电流动态变化,非常适合用于特殊负荷电流与故障电流的区分。首先根据采样速度和运算能力确定时间序列的数据窗长度;其次对同一数据窗长度内的馈线电流信号作插值处理后,依次进行相空间构造、最小二乘法拟合和关联维数计算;最后将计算结果构造成直流牵引网故障模式识别的特征矢量。实验结果表明,嵌入维数m=25时短路故障电流关联维数约为0.5,特殊负荷电流关联维数在1左右。因此设置适当的关联维数故障阈值能有效识别出特殊负荷电流,适合作为直流牵引网馈线保护算法的补偿算法。The DC traction electric network is the only power supply line for metro vehicles,but the special load current induced by vehicle speed change is easy to cause incorrect tripping of feeder protection,so it is necessary to introduce more effective feature extraction method to identify the special load current.The fractal dimension can accurately describe the dynamic change of feeder current of traction electric network in order to realize the reliable distinction between special load current and fault current.Firstly,the length of the data window of the time series is determined according to the acquisition speed and operation ability.Secondly,the phase space,the least square method fitting and the fractal dimension calculation are carried out successively after the feeder current signal within the same data window length is interpolated.Finally,the calculation result is constructed into the eigenvector for the fault pattern recognition of DC traction electric network.The experimental results show that the correlation dimension of short-circuit fault current is about 0.5 and that of special load current is about 1 when the embedding dimension m=25.Therefore,setting the appropriate correlation dimension fault threshold can effectively identify the special load current,which is suitable for the compensation algorithm of DC traction network feeder protection algorithm.

关 键 词：直流牵引网 特殊负荷电流 短路电流 故障识别 关联维数 

分 类 号：TM922[电气工程—电力电子与电力传动]