One-end impedance based fault location in double-circuit transmission lines with different configurations

A one-end impedance based fault location method suitable for double-circuit transmission lines with different end configurations is presented in this paper. The effect of mutual coupling of the circuits is taken care of in developing the algorithm. The method is developed in phase coordinates and hence it does not require the complicated six-order sequence component transformation. It is applicable to both symmetrical and unsymmetrical lines. Depending on the terminations at both ends of the line, eight different cases are discussed. The fault data required to evaluate the effectiveness of the method are obtained by simulating faults in different types of double circuit lines using MATLAB/Simulink. The accuracy of the proposed technique is evaluated by comparing the computed fault location with the actual fault location in the simulated models. It is shown that the method is accurate and robust for small errors in estimated equivalent source impedances.