Frequency Splitting Analysis of Wireless Power Transfer System Based on T-type Transformer Model

Liu, Jianyu; Tang, Houjun; Gen, Xin

doi:10.5755/j01.eee.19.10.5455

Cited by 15 publications

(7 citation statements)

References 17 publications

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“…and s := σ + jω (σ ≤ 0), see for example [11]. Hence, the transfer function H(s) := V 2 (s)/V 1 (s) can be written in normal form as…”

Section: Magnetic Resonancementioning

confidence: 99%

FSK-Based Simultaneous Wireless Information and Power Transfer in Inductively Coupled Resonant Circuits Exploiting Frequency Splitting

Hoeher

2019

IEEE Access

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Inductively coupled resonant circuits are affected by the so-called frequency splitting phenomenon at short distances. In the area of power electronics, tracking of one of the peak frequencies is state-of-the-art. In the data transmission community, however, the frequency splitting effect is often ignored. Particularly, modulation schemes have not yet been adapted to the bifurcation phenomenon. We argue that binary frequency shift keying (2-ary FSK) is a low-cost modulation scheme which well matches the double-peak voltage transfer function H(s), particularly when the quality factor Q is large, whereas most other modulation schemes suffer from the small bandwidths of the peaks. Additionally we show that a rectified version of 2-ary FSK, coined rectified FSK (RFSK), is even more attractive from output power and implementation points of view. Analytical and numerical contributions include the efficiency factor, the impulse response, and the bit error performance. A low-cost incoherent receiver is proposed. Theoretical examinations are supported by an experimental prototype.

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“…and s := σ + jω (σ ≤ 0), see for example [11]. Hence, the transfer function H(s) := V 2 (s)/V 1 (s) can be written in normal form as…”

Section: Magnetic Resonancementioning

confidence: 99%

FSK-Based Simultaneous Wireless Information and Power Transfer in Inductively Coupled Resonant Circuits Exploiting Frequency Splitting

Hoeher

2019

IEEE Access

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“…is the reduced effective area due to skin effects for a track with thickness t c , and skin depth δ = 2ρ/(ωµ 0 µ r ) [13] (where ρ is resistivity and µ r is relative permeability), this reduced effective area is derived in [14] from the effective area, which is the cross section of the track A = W × t c , ω is the operating frequency, and ω crit = 3.1(W + S)ρ/ µ 0 µ r W 2 t c is the critical frequency [15] of a coil with track spacing S where the resistance begins to increase significantly relative to the operating frequency due to the skin and proximity effect [16]. The skin effect depth for the conductors in the printed flat coils is of the order of 1 mm and is therefore negligible in this case but is included in the calculations for completeness.…”

Section: Theory Of Inductive Power Transmissionmentioning

confidence: 99%

Textile-Based Flexible Coils for Wireless Inductive Power Transmission

Grabham

Torah

et al. 2018

Applied Sciences

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Wireless inductive power transmission systems can potentially supply wearable devices. Power cables or batteries can be eliminated by implementing a wireless power transfer system, making the wearable devices less obtrusive to users. However, rigid coils can cause discomfort to users in wearable applications. The novel screen-printed flexible coils on textiles reported here are intended to be a low-cost and comfortable solution when integrated into clothing. A constant-width circular-spiral flat coil has been designed to minimize the detrimental effect of the low conductivity of the screen-printed flexible conductors on the efficiency of the wireless power transfer system. The coils are printed on 65/35 polyester/cotton textile with a screen-printed Fabink-UV-IF1 interface layer coating. The interface layer provides a relatively flat and smooth surface to prevent the permeation of the conductive paste into the textile and allows the printing of finer-profile coils. A 5 V 1.2 W DC output has been achieved by a wireless power transfer system using the printed flexible coils with Qi standard circuitry; a DC-DC efficiency of 37% has been measured.

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“…Basically, WPT systems for battery electric vehicles are used to transfer electrical energy from a source coil to a receiving coil connected to a charging system. Te peculiarity of this process lies in the fact that the energy transfer is performed via magnetic induction, without wires and cables [13][14][15][16][17]. It turns out that the magnetic coupling between the coils plays a fundamental role in the efciency of the energy transfer, and the determination of the mutual inductance between the emitter and the receiver becomes necessary to get helpful knowledge about the coupling strength.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Inductive Coupling between Coplanar Concentric Coils in the Presence of the Ground

Parise

2024

International Journal of Antennas and Propagation

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An analytical approach is presented that allows deriving an exact series-form representation for the flux linkage between two physically large concentric circular coils located on a lossy soil. The expression comes from a three-step analytical procedure. First, the integral expression for the flux linkage is converted into a double integral consisting of a finite and a semi-infinite integral. Next, the semi-infinite integral is recognized to be a well-known tabulated Sommerfeld integral, which may be analytically evaluated straightforwardly. Finally, applying Lommel’s expansion allows rewriting the remaining finite integral as a sum of elementary integrals amenable to analytical evaluation. As a result, the flux linkage between the two coils is given as a sum of spherical Hankel functions of the wavenumber in the air and in the ground, multiplied by a coefficient depending on the geometrical dimensions of the coils. The accuracy and robustness of the proposed formulation is tested by comparing its outcomes with those generated by numerical integration of the complete integral representation for the flux linkage and with the results provided by previous analytical approaches to the same problem. It is found that the use of the derived expression for the inductance makes it possible to obtain significant time savings as compared to numerical quadrature schemes.

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Frequency Splitting Analysis of Wireless Power Transfer System Based on T-type Transformer Model

Cited by 15 publications

References 17 publications

FSK-Based Simultaneous Wireless Information and Power Transfer in Inductively Coupled Resonant Circuits Exploiting Frequency Splitting

FSK-Based Simultaneous Wireless Information and Power Transfer in Inductively Coupled Resonant Circuits Exploiting Frequency Splitting

Textile-Based Flexible Coils for Wireless Inductive Power Transmission

Evaluation of the Inductive Coupling between Coplanar Concentric Coils in the Presence of the Ground

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