High Impedance Fault Detection Method Based on Sparsity of Traveling Wave Full Waveform Energy Distribution

Abstract

The transition resistance of high impedance fault (HIF) in distribution network can reach thousands of ohms. The fault characteristics are weak, and it is easy to be confused with normal transient disturbances (NTD), such as no-load line switching, load switching, capacitor switching. Therefore, the fault detection is very difficult. In this paper, the difference of traveling wave full waveform energy distribution between HIF and NTD is deeply analyzed: the energy distribution of HIF is relatively uniform, and the degree of sparseness is small; the energy distribution of NTD is relatively concentrated, and the degree of sparseness is large. Accordingly, a HIF detection method based on the energy distribution sparsity of the traveling wave full waveform is proposed. By calculating the sparseness factor of the time-frequency energy spectrum matrix of the traveling wave full waveform, the sparsity of the energy distribution is represented, and the HIF detection criterion is constructed to reliably identify the and NTD. Simulation analysis shows that this method can sensitively and reliably detect HIF in distribution networks up to 5kΩ.