A Novel Fault Location Method for HVDC Transmission Lines Based on the Wavefront Characteristics of Line-Model Component of Fault Voltage

A high voltage direct current (HVDC) transmission line fault location scheme based on the fitting coefficients of the line-model component of fault voltage (LMCFV) wavefront is proposed to address the problem of reduced accuracy in existing DC line fault location methods due to fault resistance. Firstly, the propagation characteristics of the LMCFV on the DC line are analyzed, and it is found that the LMCFV is mainly affected by the value of the fault resistance at the fault point and the dispersion during the DC line propagation. Therefore, a logistic function is used to fit the wavefront of the LMCFV, and a power function is constructed based on the mapping relationship between the fitting coefficients and the fault location. Finally, the fault position of the DC line is located by using the fitting coefficients of the LMCFV wavefront. The proposed method is implemented in a hybrid cascaded HVDC transmission system, and simulation results demonstrate that the fault location method is immune to the effects of fault resistance and does not require accurate wave speed. The proposed method exhibits high accuracy in fault location.