Power losses distribution in the litz-wire winding of an inductor for an induction cooking appliance

In this paper the squared-field-derivative method for calculating the losses in the winding of an inductor for induction cooking is derived. It is based on a 2D finite-element eddy-current simulation. For a given geometry just one simulation is needed for the analysis. The equivalent resistance of the winding and the optimum number of strands for a wire diameter and frequency are obtained. The distribution of the resistance inside the winding is obtained too, in order to localize the hot spots of the inductor. Also how the resistance of the winding change due to temperature caused by the variation of the conductivity of the winding material and the permeability of the materials which form the load (cookware).