A Single-Terminal Traveling Wave Fault Location Method for VSC-HVDC Transmission Lines Based on S-transform

A single-terminal traveling wave fault location method for VSC-HVDC transmission lines based on S-transform is proposed. S-transform is applied to analyze the amplitude variation of the line-mode fault traveling wave signal on each frequency component. The moments corresponding to the modulus maximums of the high frequency components are exactly the traveling wave arrival times. Combining with the propagation law of fault traveling wave in VSC-HVDC system, three wave heads can be identified, one is the wave head of the initial transient traveling wave, the other two are the wave heads of the first reflected traveling waves at the fault point and the opposite DC bus, respectively. The fault location can be implemented with the three wave heads, which can avoid the influence of wave velocity. The PSCAD simulation results show that the proposed method has high accuracy without being affected by transition resistance theoretically.