Electromagnetic integration of high power resonant circuits comprising high leakage inductance transformers

Known core shapes and leakage flux paths (LFP) for electromagnetically integrated transformers (EMIT) are classified and extended to new core shapes and winding structures. The distinctive feature of the classification is the orientation of the leakage flux path (magnetic shunt) with respect to the axis of the windings (perpendicular or aligned) and the direction of the compression of the core. After discussing the properties of the presented structures the low profile shapes are compared by means of volume, magnetic path length and mean turn length. The flux and current distribution of the EMIT needed for the comparison are calculated by combining fundamental frequency analysis with reluctance models. Finally, measurement results for two prototypes are presented.