A novel method for reduction of coil weight and size in wireless power transfer

Abstract

Higher switching frequency in wireless power transfer (WPT) applications leads to higher efficiency and makes it possible to transfer the same power in higher distances or in smaller footprints. The footprint and switching devices operational frequency limitation, make the efficient power transmission impractical in small available footprint of coils or high power transmission. In this paper a novel approach is proposed, which is based on filtering an odd harmonic of fundamental switching frequency instead of fundamental switching frequency. This results in higher transfer frequency at the same switching frequency. Additionally, the paper investigates appropriate converter for this approach. The selective harmonic approach decreases the required mutual inductance dramatically. This advantage leads to far smaller and lighter coils in the same coupling distances and the same application. The accuracy and effectiveness of this approach and the designed converter is verified by simulation.