Generalized Equivalent Circuit and Algorithm for Single-End Fault Location in Transmission Systems

Fast and accurate fault location is vital for maintaining the reliability of power systems at an acceptable level. In this article, a generalized equivalent circuit (GEC) is proposed for fault location in transmission systems based on voltage and current phasors of one end of the transmission line. Based on the proposed GEC, a generalized fault location algorithm (GFLA) is designed that can be implemented for finding the location of both symmetrical and unsymmetrical faults in single/double circuit, coupled/uncoupled, and transposed/untransposed transmission lines. The proposed method can accurately obtain the location of faults without any knowledge of the fault type, faulted phase (s), and without applying sequence networks for a specific fault type. Moreover, it does not require the source impedance as an input and it is robust against uncertainties such as fault impedance. Although the proposed GFLA is iterative, it is very fast and not sensitive to the initial guess of the fault location. The simulation results show the generality and accuracy of the proposed method, which makes it suitable for various fault location applications.