Finite Difference Model for the Calculation of Eddy Current Losses in Foil Windings of Distribution Transformers

This paper presents a 2D model for calculating the magnetic vector potential, current density distribution and losses in foil windings of distribution transformers based on the finite difference method. The model solves a Helmholtz equation in the complex domain to obtain the magnetic field and to account for the eddy currents induced in the foil winding. The factor of increased losses due to eddy currents was calculated and all results were validated by comparison with the model based on the finite element method.