Use of Fourier Transform to Detect the Relationship Between Voltage and Current Distortion of the Transformer with Damage to the Winding

Abstract

Detection damage to power transformers of substations during their operation is an urgent task, given the intellectualization of the power supply system (SmartGrid). This allows predicting changes in the electrical parameters of the equivalent circuit of the transformer. At the same time, the problems of studying the connection between the parameters of the transformer mode with a change in its electrical or magnetic parameters have not found an unambiguous solution. The aim of the work is to determine the relationship between the nature of the change in the electrical parameters of the mode with turn windings. The equations of the electric circuit of the transformer windings for one of the phases, as well as the equations of the electromagnetic balance are used. The equations are presented for the case of short circuits of a part of the primary or secondary windings. Experimental studies of a laboratory transformer with obvious damage to the windings have been carried out. Using the Fourier transform, the analysis of the current and voltage of the phases of the transformer in no-load and load mode is carried out. As a result of comparing the obtained time and spectral diagrams with the obtained analytical relationships, it was found that the damage belongs to the primary or secondary winding affects the degree of saturation of the magnetic circuit. The obtained results can be used in the implementation of monitoring systems for power transformers of substations in the SmartGrid structure.