A Fault Line Detection Method Based on VMD and Phase Space Reconstruction for Resonant Earthed System

On the premise of improving the traditional line detection method based on transient zero sequence current (TZSC) waveform comparison, a fault line detection method based on variational mode decomposition (VMD) and phase space reconstruction was proposed in this paper. First, the first modal component was extracted by VMD of the TZSC of each line running up to the first feature extraction and noise elimination. Then the phase space reconstruction of the extracted modal component was carried out by using coordinate delay method. The C-C algorithm was used to estimate the optimal phase space reconstruction dimension and time delay. The mean dimension and time delay were taken respectively for creating similar phase spaces to achieve the second feature extraction. Finally, the phase space similarity matrix was established by comparing the similarity degree of every two zero sequence current phase spaces. Calculate the comprehensive correlation coefficient, and the line with the minimum comprehensive correlation coefficient was selected as the fault line. The simulation results verified the applicability of the line selection method, high sensitivity and strong anti noise.