Enhancing wireless power transfer capability of inductive power transfer system using matrix power repeater

Abstract

Matrix power repeaters (MPRs) with multiple unit cells have been successfully used in far field radio systems for concentrating electromagnetic waves. However, their effects on the field distribution in non-radiative near field wireless power transfer systems are not well understood. This paper is to propose a new method for enhancing the wireless power transfer capability of Inductive power transfer (IPT) systems using MPRs. A system model is established by considering the contributions of each individual unit cell of a typical MPR, which is used to analyze the power transfer performance of an IPT system. A critical condition in relation to the mutual inductances between the primary/ secondary coils and MPR individual coils is determined, which defines the boundary between enhancing and reducing the power transfer of an IPT system. A practical MPR is built and tested to meet the power transfer enhancement condition, and experimental results show that the output power of an IPT system is increased by 34.4%.