Fault Distance Estimation Method for Two-Terminal Transmission Line

Abstract

A new fault distance estimation method is proposed for unbalanced earth faults based on Initial Traveling Wavefronts (ITWs) in aerial mode and earth mode of travelling wave. The aerial and earth mode of travelling waves are calculated using phase-mode transformation theory. Thereafter, the time of Wavelet Transform Modulus Maxima (WTMM) of aerial mode component and earth mode is analyzed for fault distance estimation. This algorithm does not require synchronized measurement and pre-estimation of transmission line parameters. The efficacy of the algorithm is verified by generating diverse fault cases using PSCAD/EMTDC software. Results shown in paper shows its capability of accurate fault distance estimation under comprehensive variation in type of fault, line length, fault inception angle, fault resistance and source impedance. Subsequently, its accuracy remains almost constant considering errors in line parameters.