摘要
分析了小电流接地系统单向接地故障选线的现状和基于暂态量的故障选线方法的优势,提出了基于小波包(WPT)和最小二乘支持向量机(LSSVM)相结合的故障选线方法.该方法首先利用小波包对各线路暂态零序电流信号进行多层分解,然后根据能量最大原则确定特征频带,选取特征频带内的能量特征值,最后将其输入到分类器LSSVM中,经训练得到最优故障选线模型.通过PSCAD/EMTDC搭建小电流接地系统单相接地故障仿真模型,经Matlab仿真实验证明,该方法不受故障地点、接地电阻和故障合闸角的影响,原理简单、可靠.
The development of the fault line selection of indirectly grounding system is analysed and the advantages of using transient current for fault line selection are presented,then a new fault line selection method is proposed based on wavelet packet and least square support vector machine.Firstly,wavelet package transform is applied to choose the special frequency band that has the major characteristics of zero current and energy features.After training the LSSVM by the features,the best model of fault line selection is achieved.At last,the single phase to earth fault model of indirectly grounding system is set up by PSCAD/EMTDC.MATLAB simulation tests suggest that the method is able to realize the fault line selection accurately and reliably,and it is also immune from the influence of fault location,fault transient resistance and phase angle.
出处
《兰州交通大学学报》
CAS
2012年第6期54-58,共5页
Journal of Lanzhou Jiaotong University
关键词
小电流接地系统
小波包分析
最小二乘支持向量机
故障选线
indirectly grounding system
wavelet packet
least square support vector machine
fault line detection
