Research on leakage current analysis of DC cable based on wavelet packet multi - scale decomposition

The leakage current in a DC cable refers to the current flowing through the main insulation from the core to the metal sheath, reflecting the overall moisture and overall deterioration of the medium. There are differences in the leakage current waveforms in DC cables with different fault defects. In this paper, three common fault model structures are constructed based on XLPE cables, and the collected leakage current signals are analyzed by wavelet packet transform. The results show that the wavelet packet decomposition method can effectively analyze the leakage current of DC cables and deduce the fault types according to the leakage current characteristics of different defects.