An improved two-dimensional numerical modeling method for E-core transformers

A new 2D modeling method for E-core transformers adds an extended flux return path to the model of the section perpendicular to the core. Averaged with a section parallel to the core modified to have the same reluctance as the 3D model, the finite-element simulation results for total magnetic energy and magnetic energy in the windings are within 0.2-5.6% error relative to the 3D model in fifteen of sixteen cases, a large improvement over existing methods. A refinement of fringing-flux calculations for gapped core legs is also presented.