Wide-Area Backup Protection Scheme for Transmission Lines Considering Cross-Country and Evolving Faults

Wide-area fault detection and location for cross-country and evolving faults have not been discussed before in the open literature. This paper presents an innovative wide-area backup protection scheme for untransposed transmission lines considering cross-country and evolving faults. Synchronized voltages and currents measurements in the phase domain are used for fault detection and location. The proposed scheme can distinguish transmission line faults from other external faults or different operating conditions. The faulty line is correctly identified, and the locations of all fault types including cross-country and evolving faults are estimated precisely. The proposed scheme is investigated under different fault locations, fault resistances, fault types, and fault inception angles. In addition, the influence of transmission line parameter errors and synchronization errors on the proposed scheme is investigated. Extensive simulation studies are applied to New England 39-bus test system, and the simulation results prove that the proposed scheme yields better performance for all simulated cases.