Automatic fault location method for traveling wave on HVDC transmission line using single-terminal data

Traditional traveling wave methods for locating faults on transmission lines have the deficiency of being hard to catch the second wave head and unable to automatically achieve. A novel automatic method to the single-ended traveling wave fault location for CSC-HVDC transmission lines is presented. When a fault occurs on a DC line, the DC filter and the smoothing reactor which are located in the end of the DC line constitute a physic boundary for the voltage traveling wave, and the boundary will cause total reflection to high-frequency traveling voltage waves. Since the refraction of the traveling wave at the fault point is much stronger than the reflection, based on the distributed parameter model, the voltage distribution of the DC line can be calculated by using the high-frequency voltage and current measured in the local terminal. Therefore, the fault can be located by seeking the strongest superposition point that is constituted by the forward and back voltage waves. Different from traditional traveling wave methods, the proposed method does not need to catch the second wave head and it is automatic. Simulation results show that this method has satisfying accuracy that the error of 1000 km is only 800 meter, and its results are free from the influence of transition resistance.