AC resistance in medium frequency transformers with foil windings: A computational study

The challenges and flexibilities of calculating AC foil winding losses using known numerical techniques are addressed. The performance of quick 1D models is compared with the exhaustive 2D and 3D models covering the geometries with increased isolation distances. The dependency of AC resistance on isolation distances and the operating frequency is investigated. In 2D geometries, the magnetic field distribution variation inside and outside the core window is carried out. The viability of using double 2D FEM method as an alternative for 3D FEM is explored for a wide range of geometric specifications. The accuracy of AC resistance calculations is validated experimentally with a laboratory prototype.