Transformers and power quality - Part II

This article investigates the generation of high harmonics in the magnetizing current of small three-phase transformers using the magnetic field analysis, the Finite Element Method (FEM). Through the analysis of the magnetic field in low power three-phase transformers, the magnetizing current waveform in the three phases of the transformer was obtained. The Fourier transform was then applied to obtain the harmonic analysis of the phase currents and determine their harmonic spectrum. Using the magnetic field analysis approach, the study aims to show that the generation of high harmonics in three-phase transformers – either low power ones or the power transformers in the electricity network – significantly influences the quality of electricity and its deterioration