Novel protection scheme for high‐voltage direct‐current transmission lines based on one‐terminal transient AC voltage

Abstract

This paper considers the distributed capacitance of transmission lines to research the protection of high‐voltage direct‐current (HVDC) transmission line. According to the superposition theorem, the post‐fault superimposed network of HVDC system is used to analyse the characteristic of the root mean square (RMS) of specific frequency voltage (SFV) during the transient period of internal and external faults. At the parallel resonant frequency of DC filter, for internal faults, the fluctuation of the RMS of transient AC voltage is larger than that of external faults. Based on the fluctuation characteristic of single‐terminal transient AC voltage, a novel protection scheme for HVDC transmission lines is proposed. Various simulation results show that the proposed protection is immune to fault resistance and performs well under different fault types.