Maximum Power Transfer versus Efficiency in Mid-Range Wireless Power Transfer Systems

Abatti, Paulo José; Pichorim, Sérgio Francisco; Miranda, Caio M. de

doi:10.1590/2179-10742015v14i1433

Cited by 19 publications

(29 citation statements)

References 7 publications

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“…Then, both parameters deteriorated when the distance increased. The other conclusions of the current work are consistent with the findings in the literature [36][37][38][39][40][41][42].…”

Section: Stlc Resultssupporting

confidence: 93%

Single-Tube and Multi-Turn Coil Near-Field Wireless Power Transfer for Low-Power Home Appliances

et al. 2018

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Single-tube loop coil (STLC) and multi-turn copper wire coil (MTCWC) wireless power transfer (WPT) methods are proposed in this study to overcome the challenges of battery life during low-power home appliance operations. Transfer power, efficiency, and distance are investigated for charging mobile devices on the basis of the two proposed systems. The transfer distances of 1–15 cm are considered because the practicality of this range has been proven to be reliable in the current work on mobile device battery charging. For STLC, the Li-ion battery is charged with total system efficiencies of 86.45%, 77.08%, and 52.08%, without a load, at distances of 2, 6, and 15 cm, respectively. When the system is loaded with 100 Ω at the corresponding distances, the transfer efficiencies are reduced to 80.66%, 66.66%, and 47.04%. For MTCWC, the battery is charged with total system efficiencies of 88.54%, 75%, and 52.08%, without a load, at the same distances of 2, 6, and 15 cm. When the system is loaded with 100 Ω at the corresponding distances, the transfer efficiencies are drastically reduced to 39.52%, 33.6%, and 15.13%. The contrasting results, between the STLC and MTCWC methods, are produced because of the misalignment between their transmitters and receiver coils. In addition, the diameter of the MTCWC is smaller than that of the STLC. The output power of the proposed system can charge the latest smartphone in the market, with generated output powers of 5 W (STLC) and 2 W (MTCWC). The above WPT methods are compared with other WPT methods in the literature.

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“…Then, both parameters deteriorated when the distance increased. The other conclusions of the current work are consistent with the findings in the literature [36][37][38][39][40][41][42].…”

Section: Stlc Resultssupporting

confidence: 93%

Single-Tube and Multi-Turn Coil Near-Field Wireless Power Transfer for Low-Power Home Appliances

et al. 2018

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“…For example, if M 23 is controlled by the distance between coils 2 and 3, then efficiency increases with the distance, as in an ideal four-coil system. 20 Oppositely, when R 3 → 0, it can be seen that efficiency still passes through a point of maximum in terms of M 23 ; however, as shown in (18) and (19) and Figure 2, it will be lesser than ηj R 2 →0 for all values of M 23 .…”

Section: Impact Of Relay Circuit Lossesmentioning

confidence: 86%

“…A relative power transfer can be found as the relation between the transferred power (P 4 = R 4 |i 4 | 2 ) and the maximum power transfer, resulting in a normalized parameter that can be easily related with efficiency values 20 . It can be shown that the maximum power possible to transfer (P MAX ) follows the maximum power transfer theorem and is given by 10,20…”

Section: Four-coil Systems' Equationsmentioning

confidence: 99%

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On the impact of relay circuit losses in four‐coil wireless power transfer systems

Miranda

Pichorim

Abatti

2019

Circuit Theory & Apps

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In wireless power transfer (WPT) systems with more than two coils, the intermediary or relay circuits are used to extend the link distance. Thus, to achieve this extension efficiently in terms of power transfer, these relay circuits must have low losses. However, there are several instances in which there are restrictions in reducing the ohmic losses in all the relay circuits of the system. This is the case of biomedical applications where commonly there are size and access restrictions since one of the circuits can be implanted and also in applications using high-temperature superconductor (HTS) coils due to the difficulty in implementing the necessary cooling system for all the coils of the system. Therefore, in these situations, the designer need to choose which relay circuit will be optimized. In this work, it is presented an analysis on the impact that losses in individual relay circuits have on efficiency, and power transfer, of typical four-coil wireless power transfer systems consisting of circuit 1 (transmitter), relay circuits 2 and 3, and circuit 4 (load). It is shown that the losses on relay circuit 2 have greater impact on efficiency, while the losses of relay circuit 3 have a greater impact on power transfer for a given condition. Practical experiments confirm the developed analysis.

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“…Figure B shows the photo of the proposed model prototype. The coupling coefficient of the two coils at different face‐to‐face distances is measured using the signal generator to excite one coil and the digital oscilloscope to measure voltage on the primary and the open secondary coil, as first presented in Abatti et al, and the result is shown in Figure A.…”

Section: Design Example and Experimental Verificationmentioning

confidence: 99%

Design of compensation network with variable inductance for wide variation of coupling coefficient in inductive power transfer

Ðurić

Pajnić

2019

Circuit Theory & Apps

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Summary In this paper, a design of the compensation network with a variable inductor is proposed, considering a wide variation of the coupling coefficient in the inductive power transfer (IPT). The characteristics of the proposed compensation network are analyzed with respect to the variable antenna coupling conditions. The realization of the zero voltage switching (ZVS) and the reactive power demand are discussed through the theoretical deduction and numerical simulation. Influence of the variable inductor on the compensation network characteristics is examined in detail, and the control algorithm for achieving the coupling independent constant output voltage is proposed. Detailed steps to design a prototype fulfilling all performance requirements are given. Verification of the proposed method was carried out on the experimental model. Recorded output voltage variation is within 5% over the wide coupling range, implying a quite well characteristic of the coupling independent voltage output. Experimental results match well with the calculations, validating the rightness of the proposed variable inductor tuning method.

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Maximum Power Transfer versus Efficiency in Mid-Range Wireless Power Transfer Systems

Cited by 19 publications

References 7 publications

Single-Tube and Multi-Turn Coil Near-Field Wireless Power Transfer for Low-Power Home Appliances

Single-Tube and Multi-Turn Coil Near-Field Wireless Power Transfer for Low-Power Home Appliances

On the impact of relay circuit losses in four‐coil wireless power transfer systems

Design of compensation network with variable inductance for wide variation of coupling coefficient in inductive power transfer

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