Novel Approach to Traveling-Wave-Based Fault Location in Nonhomogeneous Lines

Hardware that utilize traveling waves (TWs) for fault location are increasing in popularity in the US power grid because they provide a marked improvement in accuracy. These TW-based methods of fault location rely on the accurate estimation of the TW propagation speed along the faulted line. Consequently, in nonhomogeneous lines where the TW propagation speed along different sections vary from one-another, using a single velocity for the entire line can introduce errors in the calculated fault location. This paper proposes a novel technique that improves the accuracy of TW-based fault location in nonhomogeneous lines compared to the Type-D method. In addition, it also presents an improved method of estimating the TW propagation velocity along individual segments of multi-segmented nonhomogeneous lines. The paper also provides numerical illustrations and simulation results depicting the effectiveness of the proposed method in fault location and TW propagation velocity estimation.