A New Fault Detection Method for Protection of a Two Terminal Transmission Line System

Abstract

This paper illustrates a new approach to detect different types of faults occurring in a two terminal transmission line network. In this proposed method, current phasors are estimated using discrete Fourier transform and a Euclidean distance based fault index is designed to detect faults. The basic idea of any detection algorithm is simply detection of variation of network signal when system subjected to random changes. But this leads to unnecessary trip signal during non fault events like frequency deviation, load changes, noise, power swing, CT saturation etc. if the algorithm is effective then it will handle different situations in an accurate manner. The proposed method detects different types of normal faults, faults with high impedance, faults locating at remote ends and some of the non fault events. The method also discriminate non fault cases from faults. All above situations and a suitable limit value which classifies faults from non fault events. Results are verified in MATLAB-SIMULINK software.