Eddy current loss in windings

Magnetic components, such as transformers and inductors, are essential parts of most power electronics circuits. They usually are the largest components in the circuit, and also account for a large portion of the power loss. Reducing the volume of magnetic components requires them to operate at higher frequencies. Thus, a study on the high-frequency effects in magnetic components becomes important.; Winding loss is a significant part of the total power loss in inductors and transformers. An important characteristic of the winding loss is that it increases dramatically with frequencies due to the eddy-current effects in wires. Understanding and accurately predicting eddy-current effects are very important in the design and optimization of high-frequency magnetic components such as inductors and transformers. Due to the interactions between wires in the winding, the accurate analytical solution of eddy current loss becomes a difficulty. Some approximate models were presented in previous works for predicting the eddy current loss, such as the Dowell model and the Bessel-function model. However, the accuracy of these models was not satisfying at very high frequencies.; In our work, we construct a model that can predict the winding loss which significantly reduces the error of previous methods (reducing it from 60% to 4%) over a large frequency range, for various spacings between wires in the winding and for both rectangularly packed windings and hexagonally packed windings. A complex permeability model for windings is also derived to extend the application of the new eddy-current loss model to various winding geometries. Experimental tests are performed and validate our model. Discussions on flow this model can improve present winding design methods for inductors and transformers is also included.