AC resistance Prediction of Litz Wire Planer Spiral Coil Based on Litz wire Loss Model

Abstract

The Litz wire is utilized to wireless power transfer system and induction heating according to has small AC resistance in high frequency. Prediction of AC resistance of the Litz wire is important for design optimization of the Litz wire, hence the recent study has proposed analytical AC resistance prediction model of the Litz wire. However, verification in practical coils using the Litz wire is still insufficient. The purpose of this paper is to verify the prediction accuracy of AC resistance using a full analytical model in a practical coil. For practical coil, planer spiral coils are selected, and AC resistance of the planer spiral coil is calculated by combining with the loss model and the FEM analysis. As a result, the Litz wire loss model is found to well predict the measured AC resistance of the Litz wire planer spiral coil, supporting the appropriateness of the Litz wire loss model.