Scalability Analysis of SIMO Non-Radiative Resonant Wireless Power Transfer Systems Based on Circuit Models

Hwang

et al. 2018

J Electromagn Eng Sci

In this paper, the efficiency of single-input multiple-output (SIMO) wireless power transfer systems is examined. Closed-form solutions for the receiver loads that maximize either the total efficiency or the efficiency for a specific receiver are derived. They are validated with the solutions obtained using genetic algorithm (GA) optimization. The optimum load values required to maximize the total efficiency are found to be identical for all the receivers. Alternatively, the loads of receivers can be adjusted to deliver power selectively to a receiver of interest. The total efficiency is not significantly affected by this selective power distribution. A SIMO system is fabricated and tested; the measured efficiency matches closely with the efficiency obtained from the theory.

Section: Introductioncontrasting

confidence: 58%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation of Single-Input Multiple-Output Wireless Power Transfer Systems Based on Optimization of Receiver Loads for Maximum Efficiencies

Hwang

et al. 2018

J Electromagn Eng Sci

IEEE Trans. on Signal and Inf. Process. over Networks

“…For (P1), the optimal current solution i n 's to (P1) can be obtained by leveraging the Karush-Kuhn-Tucker (KKT) conditions of the optimization problem [33]. Let λ ≥ 0 denote the dual variable corresponding to the constraint (16). The Lagrangian of (P1) is given by…”

Section: A Proof Of Lemma 21mentioning

confidence: 99%

Node Placement and Distributed Magnetic Beamforming Optimization for Wireless Power Transfer

Moghadam

Zhang

2018

Abstract-In multiple-input single-output (MISO) wireless power transfer (WPT) via magnetic resonant coupling, multiple transmitters are deployed to enhance the efficiency of power transfer to a single receiver by jointly adapting their source currents/voltages so as to constructively combine the induced magnetic fields at the receiver, a technique known as magnetic beamforming. In practice, since the transmitters (power chargers) are usually at fixed locations and the receiver (e.g. mobile phone) is desired to be freely located in a target region for wireless charging, its received power can fluctuate significantly over locations even with adaptive magnetic beamforming applied. To achieve uniform power coverage, the transmitters need to be optimally placed in the region such that a minimum charging power can be achieved for the receiver regardless of its location, which motivates this paper. First, we derive the optimal magnetic beamforming solution in closed-form for a distributed MISO WPT system with fixed locations of the transmitters and receiver to maximize the deliverable power to the receiver subject to a given sum-power constraint at all transmitters. By applying adaptive magnetic beamforming based on this optimal solution, we then jointly optimize the locations of all transmitters to maximize the minimum power deliverable to the receiver over a given one-dimensional (1D) region. Although the formulated problem is non-convex, we propose an iterative algorithm for solving it efficiently. Extensive simulation results are provided which show the significant performance gains by the proposed design with optimized transmitter locations and magnetic beamforming as compared to other benchmark schemes with nonadaptive and/or heuristic transmitter current allocation and node placement. Last, we extend the node placement problem to the case of two-dimensional (2D) region, and propose efficient designs for this case.

2017 19th European Conference on Power Electronics and Applications (EPE'17 ECCE Europe)

“…RIC-WPT has been considered as a key enabling technology for multiple receiver systems where a single transmitter is cross-coupled to multiple receivers [4]. Unlikely, assuming an identical mistuning percentage at each receiver is impractical in a very dynamic environment, especially in the case of crosscoupling with other receivers [3], [5].…”

Section: Introductionmentioning

confidence: 99%

A PLL control for self-tuning of parallel wireless power transfer receivers utilizing switch-mode gyrator emulated inductors

Saad

García

Alou

et al. 2017

Self Cite

In multiple receivers wireless power transfer (WPT) systems, it is preferable to retune the resonant frequency of every receiver to the transmitter operating frequency in front of frequency mismatches. This paper discusses a proposal for electronic tuning for WPT receivers by means of a variable active switch-mode inductance. The proposed method benefits from the gyrator concept to emulate a variable inductance. Instead of the conventional approach of linear amplifier based implementation of a gyrator, a switch-mode gyrator circuit is exploited for more efficient operation. Additionally, a PLL-like control is presented to enable self-tuning for the receiver resonant tank. Furthermore, a design-space characterization for the system dynamic behavior has been discussed to show the control robustness and the instabilities (including slow-scale and fast-scale chaotic instabilities) it may undergo.