A Lissajous based Technique for Fault Detection and Faulty Phase Identification in Transmission Line

This study presents a technique for fault detection and faulty phase identification in transmission lines based on the change in the Lissajous pattern. Lissajous figure reveals distinct pattern during faults and can discriminate the faulty condition from the normal operating condition of the line. Fault Index has been calculated considering a quarter cycle moving window and Euclidean norm. Faults can be detected and classified within half cycle from the inception of fault and accurate results have been obtained for fault resistance upto 50 ohms. The ten types of faults have been simulated throughout the length of the transmission line and a threshold value offault index has been considered for fault discrimination. It has been observed that the fault indices of the faulty phases rise above the threshold value within half cycle of fault inception.