Loss models for shaped foil windings on low-permeability cores

The cross section of foil windings used in ungapped, low-permeability cores can be modified to reduce total winding loss. The optimal cross-section shape is determined to have a linear cut out and a loss model is developed to calculate the winding loss in foil windings with this cross-section. The loss model shows excellent accuracy when compared to the loss determined by finite-element analysis. The loss model has been used to implement an optimization that determines the lowest loss cross-section for a particular application.