一种基于谐波小波的单相接地故障选线方法

为了提高配电网单相接地故障选线方法的精度和鲁棒性,重点分析了谐波小波的表达式及谐波小波变换算法,在这基础上提出了一种基于谐波小波的单相接地故障选线方法。该方法首先在线路出口处并联谐振滤波装置,改变线路出口处的特征阻抗,然后将采样到的故障信号运用谐波小波变换算法完成对暂态电流特征频带内电流成分提取,最后通过比较特征频带内暂态电流能量幅值及能量衰减系数实现故障选线、选相。仿真实验表明该方法选线精度高而可靠,具有较高的工程应用价值。

A Method of Single Phase-to-ground Faulty Line Selection Based on Harmonic Wavelet

In order to improve the precision and robustness of single phase-to-ground faulty line selection method effectively in distribution network,the expression and transform algorithm of harmonic wavelet were analyzed in detail.Then,a single phase-to-ground faulty line selection method based on harmonic wavelet was presented.In the method,a resonant filter device which could charge line characteristic impedance was paralleled in transmission line export.Then transient current component of fault signal in feature frequency band was extracted.Finally,the faulty line selection method achieved faulty line and faulty phase selection through comparing transient current energy and energy attenuation coefficient in feature frequency band.The simulation test result showed that the method has high precision and reliability,at the same time it has high project application value.