VMD-DTW Clustering Based Fault Line Selection for Single-phase Grounding in Distribution Networks

The fault mechanism of the distribution system is intricate, and there is an accumulation of errors during the process of extracting and analyzing fault features, which poses challenges in achieving desired outcomes using existing fault line selection methods. To address this issue, a fault line selection method that combines variational mode decomposition (VMD) with dynamic time warping (DTW) clustering is proposed. In this study, the operational state of the distribution network after a single-phase grounding fault occurrence is analyzed, focusing on transient zero-sequence current characteristics. The current signal decomposition process is regarded as a variational optimization problem by utilizing VMD to identify an optimal solution for signal decomposition. DTW is introduced to handle the time data sequence of decomposed current signals and calculate similarity between different decomposition modulus. After determining clustering centers, healthy lines and faulty lines are clustered based on similarity measures, ultimately generating results for single-phase grounding fault line selection. Experimental results demonstrate the effectiveness of the proposed method, consistently achieving fault line selection accuracy above 0.95 under various noise conditions while meeting requirements for addressing single-phase grounding faults in distribution networks.