A robust fault location algorithm for single line-to-ground fault in double-circuit transmission systems

This paper proposes an enhanced noise robust algorithm for fault location on double-circuit transmission line for the single line-to-ground (SLG) fault with distributed parameter line model that considers the effects of mutual coupling, shunt and series capacitances. The proposed algorithm requires only the voltages and currents from single-terminal data and does not require adjacent circuit current data. The fault distance can be easily determined by solving a second-order polynomial equation, which can be achieved directly through the analysis of the fault circuit. The algorithm, which employs the faulted phase network and zero-sequence network with source impedance involved, effectively eliminates the effect of load flow and fault resistance on the accuracy of fault location. The proposed algorithm is tested using MATLAB/Simulink under various fault locations and shows high accuracy. The uncertainty of source impedance and the measurement errors are also included in the simulation due to which the algorithm is highly robust.