基于改进DTW的接地故障波形互相关度聚类选线方法

谐振接地系统发生单相接地故障时，各线路暂态零序电流波形具有非线性非平稳特性，故障线路与非故障线路的暂态零序电流波形存在差异性，提出一种基于改进动态时间弯曲距离(DTW)的接地故障波形互相关度聚类选线方法。通过改进DTW算法求取各线路发生故障后半个周期暂态零序电流波形两两之间的幅值互相关系数矩阵(ACCM)，结合暂态零序电流极性互相关系数矩阵(PCCM)，构造表征暂态零序电流幅值和极性信息的综合互相关系数矩阵(CCCM)，由免阈值设定的模糊C均值聚类(FCM)算法选出故障线路。对噪声干扰、两点接地、电弧故障、采样不同步等情况的仿真结果表明，所提故障选线方法不受工程应用中可能存在的影响因素的影响，实现可靠选线。

Faulty line selection method using mutual correlation cluster of grounding fault waveforms based on improved DTW method

When single-phase-to-ground fault occurs in resonance-grounding system, the transient zero-sequence current of each line in resonant grounding system is nonlinear and non-stationary, and there''re many differences between the transient zero-sequence current waveforms of faulty line and those of normal lines. On this basis, a fault line selection method using mutual correlation cluster of grounding fault waveforms based on improved DTW(Dynamic Time Warping) method is proposed. The ACCM(Amplitude Correlation Coefficient Matrix) of transient zero-sequence current waveforms of different lines within half cycle after fault is obtained via improved DTW method. By combing the PCCM(Polarity Correlation Coefficient Matrix) of transient zero-sequence currents with ACCM, the CCCM(Complex Correlation Coefficient Matrix) is constructed, which represents the amplitude and polarity information of transient zero-sequence currents. Then the faulty line is selected by FCM(Fuzzy C-Means) cluster method without setting threshold. The simulative results of noise interference, two points grounding fault, arc fault and asynchronous sampling show that the proposed fault line selection method is immune to possible influence factors in engineering application, the proposed method can achieve reliable faulty line selection.