An improved online minor turn-turn winding fault diagnosis in a single-phase transformer based on instantaneous induced voltages and primary current locus

Abstract

Online detection of the minor turn-turn winding fault in a single-phase transformer under no load condition using current waveform analysis is very complicated. In this paper, a new online minor turn-turn winding fault diagnosis in a single-phase transformer is proposed. Using a correlation between the instantaneous primary and secondary induced voltages difference with the primary current as a geometry location, the minor winding faults is detected effectively. The healthy transformer locus is considered as a reference locus. The minor winding faults could be detected by graphical analysis of the faulty loci with the reference locus in every cycle. Incipient winding fault detection in a single-phase transformer using the proposed technique under no load condition is a significant of this paper. The proposed locus is changed in shape and dimension by the winding faults severity. Therefore, the minor winding faults severity determination is carried out by faulty locus area comparison with the healthy locus. The experimental results validate the simulation results completely.