Rectifying loose coils: Wireless power transfer in loosely coupled inductive links with lateral and angular misalignment

Abstract-Magnetic induction (MI) based communication and power transfer systems have gained an increased attention in the recent years. Typical applications for these systems lie in the area of wireless charging, near-field communication, and wireless sensor networks. For an optimal system performance, the power efficiency needs to be maximized. Typically, this optimization refers to the impedance matching and tracking of the splitfrequencies. However, an important role of magnitude and phase of the input signal has been mostly overlooked. Especially for the wireless power transfer systems with multiple transmitter coils, the optimization of the transmit signals can dramatically improve the power efficiency. In this work, we propose an iterative algorithm for the optimization of the transmit signals for a transmitter with three orthogonal coils and multiple single coil receivers. The proposed scheme significantly outperforms the traditional baseline algorithms in terms of power efficiency.

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“…such that the order of the transmit power with respect to U T x,n reduces 6 . Then, we express |U T x,n−1 | T as…”

Section: ) Proposed Iterative Algorithmmentioning

confidence: 99%

Beamforming for Magnetic Induction Based Wireless Power Transfer Systems with Multiple Receivers

Kisseleff

Akyildiz

Gerstacker

2015

2015 IEEE Global Communications Conference (GLOBECOM)

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“…The induced voltage, magnetic field intensity at the implantable coil and coupling efficiency for two coils aligned with their axes parallel to each other and laterally displaced is given in [12], [13] by (1), (2), (3).…”

Section: B Inductive Coupling Theorymentioning

confidence: 99%

“…As an implanted coil cannot be seen or connected to external measuring devices, estimation of the exact amount of power delivered to it is complicated. Analytical [12], [13] and simulation techniques [14] are options for approximate calculations if the exact relative positions and orientations of the two coils are known. This may be done using imaging techniques like X-ray, CT or MRI but is not economical, not ideal for patient comfort and may still be inaccurate due to differences between scanning position and position of device use.…”

Section: Introductionmentioning

confidence: 99%

“…The RF current driven through the excitation coil causes a varying magnetic flux at the implantable coil inducing a voltage in it by Faraday's law. This can be harvested using rectification and energy storage elements as discussed in [13], [15] and used for powering implanted medical devices. The mutual coupling between coils causes perturbation in the excitation coil current that is proportional to the coupled power.…”

Section: Introductionmentioning

confidence: 99%

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Controllable wireless power delivery for biomedical implants

Venkateswaran¹,

Lee

Weide³

2014

2014 IEEE Healthcare Innovation Conference (HIC)

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We demonstrate a method, independent of coil geometry, orientation and separation, to measure inductive wireless power transfer to an implanted coil, without a bidirectional communication link. Load switching on the implantable coil at 1 kHz modulates the 13.56 MHz carrier signal. A lock-in amplifier detects current perturbation in the excitation coil at the switching frequency producing an output proportional to the induced current in the implantable coil. Measurements show good agreement with analytical values at different locations in a 5mm x 5mm grid for parallel and orthogonal coil orientations. Observed standard deviations are within 10% and 15% for parallel and orthogonal orientations.

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“…Inductive coupling could enhance the transmission efficiency and increase the transmission distance with the geometric design of induction coils and the selection of coupled winding wire materials [5]- [7]. With large air gap, the larger leakage inductance would reduce the transmission efficiency that it is commonly applied to enhance the transmission efficiency with capacitance compensation circuits [8], [9].…”

Section: Introductionmentioning

confidence: 99%

A hybrid genetic algorithm with fuzzy logic controller for wireless power transmission system of electric vehicles

Wang

Tai

et al. 2015

2015 IEEE International Conference on Industrial Technology (ICIT)

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A hybrid genetic algorithm with the fuzzy logic controller is developed for the high-efficiency power control of a wireless power transmission system for electric vehicles. For power regulation, the constant-frequency phase-shifted PWM is applied to regulate the inverter transmission power. In traditional genetic algorithms, a large search interval was required to avoid getting stuck in local optima. In this case, when the search interval was optimized and gradually converged to the global optimum, the parameter optimization capability in the genetic algorithm would be largely enhanced. In this paper, the compensation scheme of leakage inductance and the coil windings parameters are first analyzed and evaluated; then, the genetic algorithm is used for optimizing the parameters of a fuzzy controller in order to achieve the feedback power control for the proposed control strategy. The simulation results show the effectiveness and superiority of the proposed power control method.

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Rectifying loose coils: Wireless power transfer in loosely coupled inductive links with lateral and angular misalignment

Cited by 48 publications

References 10 publications

Beamforming for Magnetic Induction Based Wireless Power Transfer Systems with Multiple Receivers

Beamforming for Magnetic Induction Based Wireless Power Transfer Systems with Multiple Receivers

Controllable wireless power delivery for biomedical implants

A hybrid genetic algorithm with fuzzy logic controller for wireless power transmission system of electric vehicles

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