Optimization algorithm for fault location in transmission lines considering current transformers saturation

This paper deals with fault location calculations that use voltages and currents during transient conditions and pre fault values. The method uses transmission line measurements at both terminals and its main contribution is the possibility of fault location even with the lack of some current measurements as in the case of current transformers saturation or even when data acquisition process fails. The equations are based on two-port line representation that can be applied to transposed or untransposed lines and equivalent impedances at the terminals are not needed. With the proposed formulation, the algorithm does not use simplifying assumptions to calculate the fault distance and the fault resistance simultaneously. For phase-to-ground faults, the possibility of lack of accurate current measurement in one CT is assumed. For double phase-to-ground faults and three phase faults, the lack of measurements in two or three CTs, respectively, is also assumed. The results, considering different line configurations and fault types, are presented, showing the accuracy and efficiency of the proposed method.