Wireless power transfer with artificial magnetic conductors

Abstract

In this paper, a wireless power transfer system (WPT) with magnetically coupled resonators is studied. The idea to use a reflector to enhance the coupling coefficient and the transfer efficiency is proposed and analyzed. Perfect magnetic conductor (PMC) was used in numerical calculations in order to study the performance of a reflector. In the WPT system we studied, efficiency is increased from 48% without reflector to 72% with PMC reflector. With recently developed metamaterial technologies, artificial PMCs can be designed and fabricated for such reflectors. IEEE Wireless Power Transfer Conference (WPTC)This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. Abstract -In this paper, a wireless power transfer system (WPT) with magnetically coupled resonators is studied. The idea to use a reflector to enhance the coupling coefficient and the transfer efficiency is proposed and analyzed. Perfect magnetic conductor (PMC) was used in numerical calculations in order to study the performance of a reflector. In the WPT system we studied, efficiency is increased from 48% without reflector to 72% with PMC reflector. With recently developed metamaterial technologies, artificial PMCs can be designed and fabricated for such reflectors.Index TermsWireless power transfer (WPT); metamaterials; artificial perfect magnetic conductor (APMC).

A Review of Methods and Challenges for Improvement in Efficiency and Distance for Wireless Power Transfer Applications

“…Moreover, this paper matches the purpose of our paper where efficiency and distance improvements for WPT systems using 3D metamaterial topology, although the metamaterial is still a research topic and is not largely available. In a distance of 1.5 m, prototypes worked with double 3D metamaterial plates in proximity of the transmitter and receiver, precisely in the front (Choi and Seo, 2010) and back (Wu et al, 2013) of the coils showing an efficiency improvement up to 80%.…”

Opportunities and challenges of metamaterial-based wireless power transfer for electric vehicles

“…Although the metamaterial has exhibited salient advantages as aforementioned, its bulky size is still a non-ignorable technical limitation for the practical application of WPT systems [31][32][33][34]. Accordingly, a perfect magnetic conductor (PMC) on both side of transmitter and receiver coil was proposed for WPT systems [35]. For the perfect electric conductor (PEC), the image current is reversed to the direction of the originating current flow, thus producing an opposing magnetic field.…”

Efficient artificial magnetic conductor shield for wireless power

“…A backing material for the coils that theoretically results in increased link efficiency is an artificial magnetic conductor (AMC) [2]. Ideally an AMC reflects any incident EM wave with no attenuation and with no phase shift, contrasting with a perfect electrical conductor which causes a π phase shift in the reflection.…”