Determination of reverse-current coil turns layout to mitigate over-coupling in resonant inductive power transfer links

Abstract

The transfer efficiency of two-coil resonant inductive power transfer links is known to significantly degrade with a reduction of the coil distance, due to an over-coupling at shorter distances. In this work, a simple technique is introduced to determine the spatial layout of reverse-current coil turns, which suppresses the over- coupling-induced transfer efficiency drop. By employing the spatial layout of reverse-current turns as a design parameter, the proposed method provides more generality in its implementation compared to other reverse-current turn methods. Simulation and experimental results validate the method, suggesting a potential for distance- insensitive implementations.