基于特征原子测度的配电网故障选线方法

Fault line selection method for distribution network based on measurement of characteristic atom

针对现有配电网故障选线方法存在故障特征提取不够全面、故障选线判据需要样本且训练时间长等问题,提出了一种基于特征原子测度的配电网故障选线方法。利用余弦包和db10小波分别构建暂态零序电流稳态分量原子库与暂态分量原子库,从而形成混合原子库,采用匹配追踪算法提取各线路特征原子;在能量方面,采用能谱熵对各特征原子进行测度,在波形相似性方面,通过计算特征原子与原始暂态零序电流的相关系数进行测度,进而得出各线路的修正原子能谱熵;通过对修正原子能谱熵进行差分运算,得出表征各线路物理特性的综合原子能谱熵,将综合原子能谱熵最大的线路判定为故障线路。仿真结果表明,该方法不受故障过渡电阻、迭代次数、数据窗长度、消弧线圈补偿度、电容器投切等影响,选线准确、有效,具有较强的抗噪声干扰能力。

For problems that fault feature extraction was not enough and fault line selection criterion needs samples with long training time in existing fault line selection methods for distribution network,a fault line selection method for distribution network based on measurement of characteristic atom was proposed.Firstly,cosine packet and db10 wavelet are used to construct steady-state component atom and transient component atom of transient zero-sequence current,so as to form mixed atom dictionary,therefore characteristic atom of each line is extracted from the mixed atom dictionary by use of matchingtracing algorithm.Then,in the aspect of energy,energy entropy is used to measure energy of the characteristic atom,and in the aspect of waveform similarity,correlation coefficient between the characteristic atom and the original transient zero-sequence current is calculated to measure similarity of waveforms,so as to get modified atomic energy entropy of each line.Lastly,comprehensive atomic energy entropy which represents physical characteristic of the each line is obtained by differential operation of the modified atomic energy entropy,and the line with the largest comprehensive atomic energy entropy is judged as fault line.The simulation results show that the method is accurate and effective with strong antinoise interference ability,which is not affected by transition resistance,number of iterations,length of data window,compensation degree of arc suppression coil and capacitor switching.