Transmission line fault location for single-phase-to-earth fault on non-direct-ground neutral system

A new method for locating single-phase-to-earth faults on the transmission line of nondirect ground neutral power systems is presented. The method employs the faulted phase network and zero-sequence network as the fault location models. It effectively eliminates the effect of load and fault resistance on the accuracy of fault location. The technique embodies an accurate location by measuring only one local end data. The method is used in a procedure that provides the automatic determination of faulted line and phase, rather than requires engineer to specify them. Simulation results have shown the effectiveness of the algorithm under the condition of earth fault.