Influence of harmonics on the electromechanical stresses in a power transformer

Transformers are essential equipment to the power electric systems continuity and, therefore, they are object of several studies in order to determine the main factors that can exercise negative impact on the equipment performance. One of these factors are the mechanical stresses on the transformer windings. In this paper, the influence of the current harmonic profile on the transformer electromechanical stresses was analyzed and quantified using case studies based on a real harmonic profile. A significant increase in the mechanical stresses amplitudes and displacements was verified. The conclusion is that the harmonic distortion influence should not be overlooked in the process and analysis of electric transformers, especially in situations where the transformer is installed at a point in the system characterized by expressive harmonic pollution.