Core Loss Studies using FEM of a Three Phase Isolation Transformer under Harmonic Conditions

Abstract

This paper aims to investigate the effect of voltage harmonics on transformer core losses. A three-dimensional finite element method (FEM) is employed to model a three-phase isolation transformer supplied by a contaminated power source. The effect of harmonics is accurately modelled in FEM. The proposed model in FEM is verified by experiment where the results obtained using FEM show good agreement with experimental results. Different case studies with different harmonic conditions are investigated. The results show an increase in the core loss value up to 67.3% when the input voltage is formed based on the highest percentage of harmonic orders stated in the IEC 61000-3-6. As the core loss is always present, the energy loss continuously accumulates. Thus, voltage harmonics contribute to increase in the core loss in transformers.