New μPEEC formulation for modeling 2D core transformer. Principles, academic and industrial applications

Abstract

This paper presents a new μPEEC formulation that suits for modeling 2D ferrite core transformers. μPEEC method is based on the representation of magnetic materials by equivalent current densities flowing, for insulating ferrites, on the surface of the core. Firstly, the limits of available μPEEC algorithms are pointed out and improvements are achieved to overcome calculation inaccuracies linked to magnetic angular cavities (windows) dug in power electronics transformers. Secondly, the new μPEEC formulation is implemented and used to evaluate the specific inductance per turns squared (Al) of a 9kVA, 290g, 3-winding planar transformer core and results are compared to core manufacturer data. Finally, interest for power electronics engineers of having a fast and accurate computing method for designing inductors and transformers is highlighted.