SKIN – EFFECT LOSSES IN DIFFERENT LOADING CONDITIONS OF A POWER TRANSFORMER

The subject of the analysis is a 300 MVA auto-connected power transformer in different loading conditions with regard to the load losses. During the electrical design time, some operating points of the transformer were analyzed in more detail using 2D electromagnetic field finite element method (FEM) software. The models included 2D magnetic stray field calculation and covered a range of transformer loading cases that covered some that are more difficult to solve with traditional analytic methods based on the static magnetic field calculations. This is due to the presence of a phase shift between the currents through the windings. The results of the static magnetic Rabins’ method field calculation and the FEM method are compared and the best practice method is defined and determined accordingly