Receive Power Control in Multiuser Inductive Power Transfer System Using Single-Frequency Coil Array

Quang-Thang DUONG  Minoru OKADA  

IEICE TRANSACTIONS on Communications   Vol.E101-B   No.10   pp.2222-2229
Publication Date: 2018/10/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2017EBP3387
Type of Manuscript: PAPER
Category: Antennas and Propagation
inductive power transfer,  multiuser,  single-frequency coil array,  receive power control,  

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This paper investigates receive power control for multiuser inductive power transfer (IPT) systems with a single-frequency coil array. The primary task is to optimize the transmit coil currents to minimize the total input power, subject to the minimum receive powers required by individual users. Due to the complicated coupling mechanism among all transmit coils and user pickups, the optimization problem is a non-convex quadratically constrained quadratic program (QCQP), which is analytically intractable. This paper solves the problem by applying the semidefinite relaxation (SDR) technique and evaluates the performance by full-wave electromagnetic simulations. Our results show that a single-frequency coil array is capable of power control for various multiuser scenarios, assuming that the number of transmit coils is greater than or equal to the number of users and the transmission conditions for individual users are uncorrelated.