An Approach for Detecting and Locating Evolving Faults on Transmission Lines Based on Transient Traveling Waves

There has not been a satisfactory solution to identifying and locating evolving faults on transmission lines until now. This paper presents an integrated detection and location approach for evolving faults based on transient traveling waves. Evolving faults include two sequential faults, resulting in the change of fault phase. The feature aerial mode of captured current traveling wave only reflects the feature of the second fault occurrence, and is used for analyzing the second fault. By combining traveling wave and transient energy features, fault phase selection can be implemented at two stages: the initial fault occurrence, and the short period before fault clearance. The evolving faults can be determined according to the consistency of the two-stage phase-selection results. Subsequently, the positions of the two successive faults can be precisely acquired by individually implementing the double-ended traveling wave fault location on the initial fault phase as well as the feature aerial mode currents, respectively. Digital simulation studies based on the simulation software PSCAD/EMTDC demonstrate that the proposed method is feasible and effective.