FAULT ANALYSIS IN TRANSMISSION LINES USING FUZZY LOGIC

Protection of transmission lines against exposed faults is a critical requirement in power system operation. Protective relays aim to detect abnormal signals associated with faults occurring in power transmission systems; therefore, accurate and high-speed fault classification is essential. This paper presents a fuzzy logic-based approach for fault classification and proposes a method for reliable identification of ground and phase faults. The classification scheme utilizes only the post-fault magnitudes of three-phase currents and their symmetrical components. The proposed technique is capable of classifying all common transmission line faults, including single-phase-to-ground, phase-to-phase, phase-to-phaseto-ground, and three-phase faults, with high accuracy under a wide range of fault conditions. Simulation studies are conducted using MATLAB and the MATLAB Fuzzy Logic Toolbox.