A Single-end Protection Method for Multi-terminal Flexible DC Network Based on Successive Variational Mode Decomposition

Aiming at the existing multi-terminal flexible DC network line protection, which is intolerant to high resistance and susceptible to noise, a single-end protection method for a multi-terminal flexible DC network based on successive variational mode decomposition (SVMD) is proposed. Specifically, firstly, the protection startup criterion is constructed by using the DC pole voltage mutation to meet the requirement of protection rapidity; then, the fault type detection criterion is constructed by using the sum of the zero-mode voltages; and finally, the fault area detection criterion is constructed, it employs SVMD to decompose the line mode voltage because there is difference between the high-frequency component of the external faults and internal faults, and extracts the highest frequency time-frequency component as the faulty feature component whose peak value is used to realize the detection of the fault area. Many simulation experiments show that the proposed protection method can adapt to different fault transition resistances, fault types, fault distances and lines, and can identify lightning interference. © 2025 Power System Technology Press. All rights reserved.