Two-terminal fault locating method of HVDC transmission

Abstract High-voltage direct current (HVDC) transmission technology has a wide range of application scenarios and development space, but the DC line fault frequency is high, and line faults significantly endanger the stable operation of the system, and fast and accurate fault location can help to isolate the faults quickly to reduce the fault recovery time, which plays a crucial role in ensuring the stable and reliable operation of HVDC systems. Accordingly, an HVDC line fault localization method based on variational mode decomposition (VMD) and Hilbert amplitude is proposed. A sequence of IMF components is obtained by VMD decomposition of the fault traveling wave signals at the rectifier side and inverter side, and the Hilbert transform is performed to obtain the instantaneous amplitude versus time graph to determine the precise arrival time of the initial wave head by selecting the IMF with obvious mutation characteristics. The simulation outcomes demonstrate that the proposed VMD-Hilbert algorithm effectively identifies the fault traveling wave head with minimal impact from transition resistance, ensuring high-accuracy ranging results across various fault locations.