A fault location algorithm for transmission lines with tapped leg-PMU based approach

This work presents a new fault location algorithm for transmission lines with tapped legs. For the transmission lines connected with short interim tapped leg on the midway, the conventional multi-terminals fault location algorithms are inappropriate for these systems. The proposed fault location algorithm only uses the synchronized phasors measured on two terminals of the original lines to calculate the fault location. Thus, the existing two-terminals fault locator can still be used via adopting the now proposed algorithms. Using the proposed algorithm, the computation of the fault location does not need the model of tapped leg. The proposed algorithm can be easily applied to any type of tapped leg, such as generators, loads or combined systems. EMTP simulation of a 100 km, 345 kV transmission line have been used to evaluate the performance of the proposed algorithm. The tested cases include various fault types, fault locations, fault resistances, fault inception angles, etc. The study also considers the effect of various types of tapped leg. Simulation results indicate that the proposed algorithm can achieve up to 99.95% accuracy for most tested cases.