A Loosely Coupled Planar Wireless Power System for Multiple Receivers

Casanova, Joaquin; Low, Zhen Ning; Lin, Jenshan

doi:10.1109/tie.2009.2023633

Cited by 205 publications

(76 citation statements)

References 12 publications

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“…According to (8b), if there exist two sets of solutions for matching capacitance (C t > 0 and C r > 0) which are different from solution I, then it is required that: 1 …”

Section: Matching Capacitance For Maximum Power Transferred To Loadmentioning

confidence: 99%

“…The wireless power transfer (WPT) technique by magnetic coupling coils has been applied in many fields, such as portable electronic devices [1][2][3][4], electric vehicles [5][6][7], and implanted medical devices [8][9][10][11]. For mid-range air gap between transmitting and receiving coil (the distance between two coils is usually less than eight times the diameter of the coil), the power transfer efficiency is vitally important and must be given priority in applications of high-power or continuous-operation electric devices such as power supply for household appliance, vehicle charging and microwave power transmission.…”

Section: Introductionmentioning

confidence: 99%

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New Insight of Maximum Transferred Power by Matching Capacitance of a Wireless Power Transfer System

et al. 2017

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Most research on wireless power transfer (WPT) has been focused on how to achieve a high-efficiency power transfer. Our study found that under the impedance matching for achieving maximum WPT efficiency, the power transferred to the load cannot reach the maximum when a WPT system is supplied by an AC voltage source with constant amplitude. However, the load power or the voltage across the load is essential for a low-power electric device such as the implanted medical device where the transfer efficiency is not the priority to be considered. The paper presents a method for achieving maximum power on the load by matching capacitance in a WPT system with given two-coupled-coils. Three sets of matching capacitances for extreme load power were deduced based on the circuit model considering the coil's resistance, and all these three matching make the WPT system operate at the resonant state. Two sets can make the system achieve the global maximum of load power. One set can make the system achieve the local maximum of load power and reach the power transfer efficiency next to 1. Experimental results verified the theoretical calculations. The results can contribute to the compensation design of a practical WPT system for transferring the maximum power to the load.

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“…According to (8b), if there exist two sets of solutions for matching capacitance (C t > 0 and C r > 0) which are different from solution I, then it is required that: 1 …”

Section: Matching Capacitance For Maximum Power Transferred To Loadmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

New Insight of Maximum Transferred Power by Matching Capacitance of a Wireless Power Transfer System

et al. 2017

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“…Compared with the traditional inductive coupling scheme, the magnetic coupling resonator of WPT can more efficiently transmit power than the far field method, as proposed by Zhu C. [18], Zhen N. L. [19], Casanova J. J. [20], and Kim Y. H. [21]. However, fixed distance and direction limited their study, and the transmission efficiency rapidly decreased when the receiver was far from the optimum operating point.…”

Section: State Of the Artmentioning

confidence: 99%

Detuning Mechanism and Frequency Tracking Algorithm for Wireless Power Transmission System

Li¹,

Xiang²,

Li³

et al. 2017

JESTR

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Wireless power transmission (WPT) uses a loosely coupled transformer to transmit electric energy. The resulting system's transmission efficiency and distance are affected by factors such as, inductance parameter and resonance frequency offset. To reduce the influence of detuning on transmission efficiency, a frequency tracking method based on the hill-climbing algorithm was proposed in this study. The WPT model was established to depict the detuning mechanism and the transmission efficiency affected by natural frequency changes in the primary and secondary coils. Experimental data were used to prove the correctness of the theoretical analysis. Results demonstrate that the coupling coefficient of the two coils is proportional to the increase of the distance between the transmitting and receiving coils. Hence, coupling coefficient influences transmission efficiency. Another important factor is distance S, as its increase leads to mutual loss, which breaks the previous state of the best resonance compensation, which in turn reduces the transmission efficiency of WPT. When distance S increases from 10 mm to 30 mm and the system has no frequency tracking, the transmission efficiency decreases from 45% to 7.5%. However, when distance S increases from 10 mm to 30 mm and the system has frequency tracking, the transmission efficiency decreases from 70% to 19.1%. When distance S is equidistant, the transmission efficiency is much higher with than without frequency tracking. The proposed method can effectively raise the transmission efficiency of the WPT system and control the cost of hardware, which optimizes practical engineering design.

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“…The problem in (13) is a convex optimization problem. Therefore, to find an optimal solution, we consider its Lagrangian function given by (17), where λ and μ are non-negative Lagrange multipliers.…”

Section: Opamentioning

confidence: 99%

Simultaneous Information and Power Transfer Using Magnetic Resonance

Lee

Cho

2014

ETRI J

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To deal with the major challenges of embedded sensor networks, we consider the use of magnetic fields as a means of reliably transferring both information and power to embedded sensors. We focus on a power allocation strategy for an orthogonal frequency-division multiplexing system to maximize the transferred power under the required information capacity and total available power constraints. First, we consider the case of a co-receiver, where information and power can be extracted from the same signal. In this case, we find an optimal power allocation (OPA) and provide the upper bound of achievable transferred power and capacity pairs. However, the exact calculation of the OPA is computationally complex. Thus, we propose a lowcomplexity power reallocation algorithm. For practical consideration, we consider the case of a separated receiver (where information and power are transferred separately through different resources) and propose two heuristic power allocation algorithms. Through simulations using the Agilent Advanced Design System and Ansoft High Frequency Structure Simulator, we validate the magneticinductive channel characteristic. In addition, we show the performances of the proposed algorithms by providing achievable η-C regions.

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A Loosely Coupled Planar Wireless Power System for Multiple Receivers

Cited by 205 publications

References 12 publications

New Insight of Maximum Transferred Power by Matching Capacitance of a Wireless Power Transfer System

New Insight of Maximum Transferred Power by Matching Capacitance of a Wireless Power Transfer System

Detuning Mechanism and Frequency Tracking Algorithm for Wireless Power Transmission System

Simultaneous Information and Power Transfer Using Magnetic Resonance

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