Location Method of Single-Phase to Ground Fault in Distribution Network Based on Time-Frequency Matrix Analysis of Traveling Wave

This paper proposes a location method based on the analysis of the time-frequency matrix for distribution networks. Firstly, the traveling wave (TW) signal measured by the detection device at the end of each feeder is decoupled to obtain the aerial-mode component of the fault TW. Then, faults are preset at particular locations, such as the main line, primary branch, and secondary branch to construct time-frequency matrices by applying continuous wavelet transform (CWT) to the measured TW signals, and a matrix comparison library is established. The feeder and branch where the fault occurs are determined by comparing the similarity between the matrix extracted from each terminal at the time of fault occurrence and the matrix in the comparison library. Finally, this paper calculates the time for the wave head to reach the measurement point by plotting the energy evolution spectrum of the specific frequency band in the time-frequency matrix, and the precise location of the fault in the distribution network is achieved through the double-ended location method.