High-Frequency Model of the Toroidal Powder Core and Winding of a Litz Wire

A high-frequency model of the toroidal powder core inductor with litz wire winding is presented. In the analyzed model, the power losses that occurred in both the winding and the magnetic core were taken into account. A new method of determining the power losses in the winding of a magnetic element made of a litz wire with a circular cross-section, wound on a toroidal magnetic core, for both sinusoidal and deformed currents, by transforming the parameters of the wire to the Dowell equation has been proposed. The methodology of estimating the resistance for the alternating component of the current flowing through a litz wire with a circular cross-section wound on a toroidal core is shown. The influence of the type of winding wire, the shape of the core, the number of winding layers, the winding angle, and the frequency range for which the litz wire obtains lower power losses than a solid-round wire are discussed.