Improvement of power transformer differential protection through detection and exploitation of the negative sequence currents

Introduction. Power transformers are the most important and expensive equipment used in transport distribution of electrical energy. Their failure results huge economic losses. Despite great advances design power recent years, feeble link chain remains insulation weakness coil turns transformer. The novelty proposed research consists development a new procedure for diagnosing localizing occurrence turn to short-circuits windings three-phase main problems current differential relay short circuits one or more transformer winding. Hence approach using' amplitude comparison between negative sequence currents' is developed digital discriminator internal / external fault applied discriminate faults among other ones. based on exploitation currents. purpose using this identify small inside coils distinguish inner from outer by an ameliorate circuit. method paper novel algorithm which amplitudes calculate corresponding phase angle shifts. performance has been confirmed MATLAB/Simulink environment. simulation reveal efficiency suggested procedure, indicate that can provide fast sensitive detecting low level turn-to-turn faults.