Model Free Traveling Wave Based Fault Location Method for Series Compensated Transmission Line

Locating fault position in a series compensated transmission line is a difficult task due to the non-linear characteristics of the metal-oxide varistor which is present in the protection system of the compensator. In this paper, a model-free two-terminal traveling wave-based fault location method for a series compensated line is proposed. The technique makes use of two subroutines which calculate the fault locations assuming that the fault position to be on the left and right side of the series compensator respectively. The method then selects the correct fault location of the two by a special logic based on faulted half-section identification. The first two traveling wave arrival times recorded at both the terminals of the line are used in the method. The proposed technique does not require model information of the series capacitor and transmission line. It has been verified using the PSCAD/EMTDC model of a 400-kV, 300 km transmission line which is compensated by a fixed series capacitor in the middle and line ends. The performance of the proposed method is compared with a commercially available classical two-ended techniques and setting-free method.