Wireless Energy Transfer System Research Articles

Joint Design of Altitude and Channel Statistics Based Energy Beamforming for UAV-Enabled Wireless Energy Transfer

In recent years, UAV-enabled wireless energy transfer (WET) has attracted significant attention for its ability to provide ground devices with efficient and stable power by flexibly navigating three-dimensional (3D) space and utilizing favorable line-of-sight (LoS) channels. At the same time, energy beamforming utilizing multiple antennas, in which energy beams are focused toward devices in desirable directions, has been highlighted as a key technology for substantially enhancing radio frequency (RF)-based WET efficiency. Despite its significant utility, energy beamforming has not been studied in the context of UAV-enabled WET system design. In this paper, we propose the joint design of UAV altitude and channel statistics based energy beamforming to minimize the overall charging time required for all energy-harvesting devices (EHDs) to meet their energy demands while reducing the additional resources and costs associated with channel estimation. Unlike previous works, in which only the LoS dominant channel without small-scale fading was considered, we adopt a more general air-to-ground (A2G) Rician fading channel, where the LoS probability as well as the Rician factor is dependent on the UAV altitude. To tackle this highly nonconvex and nonlinear design problem, we first examine the scenario of a single EHD, drawing insights by deriving an optimal energy beamforming solution in closed form. We then devise efficient methods for jointly designing altitude and energy beamforming in scenarios with multiple EHDs. Our numerical results demonstrate that the proposed joint design considerably reduces the overall charging time while significantly lowering the computational complexity compared to conventional methods.

Compact frequency‐reconfigurable circular patch antenna with varactor diode: Design, tuning, and compactness optimization

AbstractIn this study, a frequency‐reconfigurable circular patch antenna with a varactor diode has been presented. The proposed antenna has been designed and investigated in four steps: circular patch antenna (Antenna 1), antenna with double slots (Antenna 2), antenna with quad slots (Antenna 3), and antenna with varactor diode (Antenna 4). The proposed antenna has been made compact with rectangular slots and a hyperabrupt junction tuning varactor diode (SMV1249‐079LF). The proposed antenna has been designed and produced in 32 × 32 × 0.64 mm3 dimensions, approximately 80% minimized compared to a microstrip circular patch antenna operating at 850 MHZ resonance frequency. This frequency‐reconfigurable antenna can perform between the range of 0.85–1.3 GHz frequency with 0–3 V DC voltage tuning of the varactor diode. So, using with the varactor diode, the proposed antenna has obtained a 53% tuning range between 0.85 and 1.3 GHz frequencies. This study offers a different antenna design, compactness, and high tuning ratio compared to previous studies. This frequency reconfigurable antenna can be preferred with its wideband structure in different communications areas and wireless energy transfer systems.

REVIEW OF PARAMETERS INFLUENCING WIRELESS ENERGY TRANSMISSION BY MAGNETIC INDUCTION

In this review article, we present a detailed study and discussion of wireless energy transfer systems based on studies in the literature, with the help of Python programming software. Starting from the basic element of wireless transmission by magnetic induction, i.e. the coil, through a magnetostatic study we have highlighted the impact of geometry, coil misalignment and coil loss factors on these transmission systems. We have also shown that parameters such as coupling coefficient and frequency can improve transmitted power and efficiency. A summary of the latest research in this field will also be given.

Early-stage Development of the CoRISMA Mechanical Circulatory Support (CMCS) System for Heart Failure Therapy.

CoRISMA MCS Systems Inc (Hamden CT) is developing an innovative mechanical circulatory support system (CMCS) as a durable therapeutic option for heart failure (HF) patients. The CMCS system is comprised of an axial flow pump, non-contacting hydrodynamic bearings, and integrated DC motor designed to be fully implantable in a left atrial (LA) to aortic (Ao) configuration; this unloading strategy may be particularly beneficial for HF patients with preserved ejection fraction (HFpEF). The small (5.5 cm3), lightweight (20g), and low power (5-7W) device design should allow for a less invasive off-pump implant. We present early-stage engineering development and testing of the prototype CoRISMA pumps. Computational fluid dynamics (CFD) modeling was performed to evaluate flow and shear in two impeller (3 blades, 0.5mm thickness, 8.9mm diameter, 0.15mm gap, polished titanium) and diffusor (5 blades, polished titanium) candidate designs. Test apparatuses were custom built to expedite development of the impeller/diffuser designs and iteratively refine the CFD models. Two candidate impeller/diffusor designs were fabricated and tested in each of the two test apparatuses (n = 4 impeller/diffuser + test fixture configurations) in static mock flow loops (hydrodynamic H-Q curves, 3.5 cP glycerol solution at 37°C), and in dynamic mock flow loops (hemodynamics, 3.5 cP glycerol solution at 37°C) tuned to HF conditions (mean aortic pressure 50 mmHg, central venous pressure 15 mmHg, aortic flow 3.0L/min, and heart rate 80bpm). CFD predicted flows of 4.56L/min and 4.82L/min at 100 mmHg for impellers/diffusers 1 and 2, respectively. Impeller 2 required less torque to generate a 6% increase in fluidic flow, and the diffuser had a larger area of high pressure, indicative of lower friction, which likely contributed to the increased efficiency. Experimental testing for all four configurations in the static and dynamic mock loops met performance metrics as evidenced by generating 4.0-4.5L/min flow against 70-76 mmHg pressure at 25,000rpm and restoring hemodynamics in the dynamic mock flow loop (MAP = 80 mmHg, CVP = 0 mmHg, total flow = 5.5L/min) from baseline simulated HF test conditions. These results demonstrate proof-of-concept of the early engineering design and performance of the prototype CoRISMA pumps. Engineering specifications, challenges observed, and proposed solutions for the next design iteration were identified for the continued development of an effective, reliable, and safe LA-to-Ao CMCS system for HF patients. Current design plans are underway for incorporating a wireless energy transfer system for communication and power, eliminating the need for and complications associated with an external driveline, to achieve a fully-implantable system.

Human and Small Animal Detection Using Multiple Millimeter-Wave Radars and Data Fusion: Enabling Safe Applications.

Millimeter-wave (mmWave) radars attain high resolution without compromising privacy while being unaffected by environmental factors such as rain, dust, and fog. This study explores the challenges of using mmWave radars for the simultaneous detection of people and small animals, a critical concern in applications like indoor wireless energy transfer systems. This work proposes innovative methodologies for enhancing detection accuracy and overcoming the inherent difficulties posed by differences in target size and volume. In particular, we explore two distinct positioning scenarios that involve up to four mmWave radars in an indoor environment to detect and track both humans and small animals. We compare the outcomes achieved through the implementation of three distinct data-fusion methods. It was shown that using a single radar without the application of a tracking algorithm resulted in a sensitivity of 46.1%. However, this sensitivity significantly increased to 97.10% upon utilizing four radars using with the optimal fusion method and tracking. This improvement highlights the effectiveness of employing multiple radars together with data fusion techniques, significantly enhancing sensitivity and reliability in target detection.

Parametric investigations of wireless energy transfer using strain-mediated magnetoelectric transmitter-receiver

Magnetoelectric (ME) composites inherently convert magnetic energy to electrical energy and vice-versa, making them a viable technology in wireless energy transfer (WET) applications. This article focuses on identifying the optimal configuration for achieving relatively high ME power conversion efficiency in a fully ME-based transmitter/receiver composite system. Two configurations of ME composites, one in concentric composite rings and the other in layered laminate formation, have been fabricated and used alternately as transmitters and receivers. The influence of three important parameters has been experimentally studied and reported, including the effect of (1) the magnetization state of the magnetostrictive components and (2) the relative orientation of and (3) the separation distance between the transmitter and the receiver. It has been found that a higher energy conversion efficiency is obtained in a configuration where the laminated plate was used as the transmitter while the ring composites acted as the receiver. Furthermore, the location and alignment of the receiver significantly influence the output transferred power. Lastly, the distance between the transmitter and the receiver has been observed to have an exponential inverse influence on the performance of the investigated WET system. These results have been deciphered by experimentally generating horizontal and vertical magnetic field mapping around the composite systems and capacitance measurement of the piezoelectric element. Thus, this article presents a detailed study of the parameters and their influence on the performance of the ME-based WET technology, which would be extremely useful in designing and optimizing devices based on this technology.

Control Algorithms for a Bidirectional Wireless Power Transmission System at the Redistribution of Energy Resources in a Group of Ground Robots

Redistributing energy resources within a group of ground robots allows for an increase in the reachable workspace area and expands its functional capabilities. The use of wireless energy transfer systems for exchanging energy resources between ground robots reduces the requirements for positioning accuracy and enhances the reliability of the robotic system. This study examines control and management algorithms for a bidirectional wireless energy transfer system when operating as part of a ground robot. A structural diagram of the bidirectional wireless energy transfer module is proposed for integration into the robot’s control system, built on distributed principles. The developed algorithms take into account the specific features of the circuitry solutions of the bidirectional wireless energy transfer system, implemented using an uncontrolled resonant generator. The proposed solutions are tested on a robotics platform. The experiments focus on the process of replenishing the energy resources of one robot with another robot. Energy is transmitted between robots equipped with the same Li-ion battery, which has a nominal voltage of 7.4 V and a capacity of 5 A•h. The battery is charged from 50 % to 90 % capacity with different positioning accuracies of the robots. When there is a displacement of 4 mm and a distance of 4 mm between the receiving and transmitting coils, the charging time was 48 minutes, which is 5 % longer than the wired charging method. The maximum charging time reached 57 minutes with a distance of 15 mm between the robots. The use of bidirectional wireless power transfer for energy exchange between ground robots or for charging robots at a charging station enhances the autonomy of the group’s operation, as energy transfer can be successfully achieved even with low positioning accuracy. The proposed solutions can be used for battery charging and resource redistribution processes in groups of ground and underwater robots.

Compact Near Field Wireless Energy Transfer Systems Using Defected Ground Structures

Compact Near Field Wireless Energy Transfer Systems Using Defected Ground Structures

Design and miniaturization of a microsystem to power biomedical implants using grey wolf optimizer-based cuckoo search algorithm

<p>One of the greatest techniques, inductive coupling is frequently utilized in the biomedical sector for wireless energy transfer to implants. The aim of this article is to develop and analyze the effect of inductor geometrical characteristics, distance between transmitter (TX) and receiver (RX) and also the operating frequency on the wireless power transfer system, using grey wolf optimizer-based cuckoo search (GWO-CS) algorithm. Power transfer efficiency (PTE), power provided to load, and other critical components must all be improved or maximized and miniaturaze the microsystem proposed. The invention, design, and optimization of coils square spirals in a wireless energy transfer system using a resonant inductive link are the emphasis of this paper. The GWO-CS approach is evaluated to existing methods, demonstrated by simulations and to demonstrate the effectiveness of the suggested strategy.</p>

Achieving Multi-Beam Gain in Intelligent Reflecting Surface Assisted Wireless Energy Transfer

Intelligent reflecting surface (IRS) is a promising technology to boost the efficiency of wireless energy transfer (WET) systems. However, for a multiuser WET system, simultaneous multi-beam energy transmission is generally required to achieve the maximum performance, which may not be implemented by using the IRS having only a single set of coefficients. As a result, it remains unknown how to exploit the IRS to approach such a performance upper bound. To answer this question, we aim to maximize the total harvested energy of a multiuser WET system subject to the user fairness constraints and the non-linear energy harvesting model. We first consider the static IRS beamforming scheme, which shows that the optimal IRS reflection matrix obtained by applying semidefinite relaxation is indeed of high rank in general as the number of energy receivers (ERs) increases, due to which the resulting rank-one solution by applying Gaussian Randomization may lead to significant loss. To achieve the multi-beam gain, we then propose a general time-division based novel framework by exploiting the IRS's dynamic passive beamforming. Moreover, it is able to achieve a good balance between the system performance and complexity by controlling the number of IRS shift patterns. Finally, we also propose a time-division multiple access (TDMA) based passive beamforming design for performance comparison. Simulation results demonstrate the necessity of multi-beam transmission and the superiority of the proposed dynamic IRS beamforming scheme over existing schemes.

Preface

The International Conference on Smart Energy and Electrical Engineering is a leading international conference. It aims at building an international platform for the communication and academic exchange among participants from various fields related to smart energy and electrical engineering. Here, scholars, experts, and researchers are welcomed and encouraged to share their research progress and inspirations. It is a great opportunity to promote academic communication and collaboration worldwide.This volume contains the papers presented at the 2022 International Conference on Smart Energy and Electrical Engineering (SEEE 2022), held during October 28th-30th, 2022 in Wuhan, China (virtual event). Under the impact of COVID-19 and for the safety concern of all participants, we decided to hold it as a virtual conference which is also effective and convenient for academic exchange and communication. Everyone interested in this field were welcomed to join the online conference and to give comments and raise questions to the speeches and presentations.The online conference was composed of keynote speeches, oral presentations, and academic investigation, attracting about 100 individuals from all over the world. We have invited four sophisticated professors to perform keynote speeches. For a start, Prof. Kai Yang from Huazhong University of Science and Technology, China delivered a keynote speech on the title Research on Composite Flux Motor and Its Control System. Next, Prof. Wei Xu from Huazhong University of Science and Technology, China made a speech on Advanced Linear Induction Machines and Drive Systems for Transportation. And then, Prof. Yonghui Li from University of Sydney, Australia addressed a report on Beyond 5G towards a Super-connected World. Last but not the least, Prof. Yuanchang Zhong from Chongqing University, China presented to us his study Research on Key technology of laser wireless energy transfer System. All the keynote speakers made brilliant speeches and shared unique experience and insights, and we are hoping the pandemic soon come to an end and we could see each other face to face next year.List of Committee member are available in this pdf.

Extreme Metasurfaces Enable Targeted and Protected Wireless Energy Transfer

AbstractControlling the electromagnetic properties of materials beyond those achievable with natural substances has become a reality with the advent of metamaterials. The extreme properties that metamaterials provide offer an opportunity to manipulate and tailor electromagnetic waves in an arbitrary manner. Wireless energy transfer demands reliable and stable solutions for charging batteries of electronic devices with high efficiency and no effect on people, animals, plants, etc. Motivated by this challenging problem, a novel approach of using metamaterials with extreme parameters is suggested to enable targeted wireless energy transfer with reduced impact on biological tissues. Epsilon‐near‐zero (ENZ) and epsilon‐and‐mu‐near‐zero (EMNZ) metamaterials are designed and experimentally implemented, providing an energy transmission if and only if both the transmitter and the receiver are equipped with these metamaterials. The nonexistence of these extreme parameter metamaterials in nature protects the system from the presence of other objects with “ordinary” (effective) parameters causing neither noticeable change in operation nor any detrimental effect on foreign objects. The system behind the proposed approach can be realized in virtually any frequency band by appropriate scaling and suitable choice of material. This technology will find applications in targeted wireless energy transfer systems, especially where high power is needed, including electric vehicles.

DEA-based on optimization of inductive coupling for powering implantable biomedical devices

Inductive coupling wireless power transfer (WPT) is one of the best technologies for powering implantable microelectronic devices (IMD). A wireless power transfer system’s important elements (indicators) are power transfer efficiency (PTE) and power delivered to load (PDL). The key characteristics of WPT are the size of the transmitting (Tx) and receiving (Rx) coils, the operating frequency, and the separation distance between the two parts of the system. The main goal of this research is to use the differential evolution algorithm (DEA) to optimize a wireless energy transfer system in order to maximize the PTE and PDL. By comparing the results acquired by the proposed technique to those obtained by other methodologies, we were able to validate the results obtained by the suggested method. With the aim of raising the PTE and PDL. Using this metaheuristic approach, we were able to improve WPT’s critical parameters. For is, a PTE of 95% and 136 mW of power delivered to the load for a 13 cm separation distance.

Wireless energy transfer system for use in underground mining

Wireless energy transfer system for use in underground mining

Experimental Study on the Efficiency of RF Energy Transfer System

This paper presents a 915 MHz radio frequency (RF) wireless energy transfer system which contains RF energy transmitters and RF energy harvesting nodes. Firstly, Advanced Design System (ADS) is used to design and optimize the monopole voltage doubler rectifier circuit. Secondly, an energy harvesting node is designed by a commercial RF/DC rectifier and a 915 MHz antenna. Finally, the RF energy transfer experiment between RF energy transmitter and RF energy harvesting node is demonstrated. Experimental data fits well with theoretical analysis and the harvested energy show a non-linear relationship with the distance and angle between the receiving node antenna and the transmitter antenna. The experimental data is valuable for designing RF-powered nodes and optimizing the movement trajectory of the mobile RF energy transmitter, such as an unmanned aerial vehicle (UAV).

Environmentally Friendlier Wireless Energy Transfer Systems the Coil on a Paper Approach

Environmentally Friendlier Wireless Energy Transfer Systems the Coil on a Paper Approach

Optimal design of inductive coupled coils for biomedical implants using metaheuristic techniques

Powering implanted biomedical devices (IMDs) and sensors is a major obstacle for researchers in the microelectronics field. Such as the problem of miniaturization, increasing the distance between the external part (TX) and the internal part (RX), and the improvement of the power transfer efficiency (PTE), … The purpose of this article is to compare two strategies for optimizing component characteristics for a wireless energy transfer system (coupling of two coils), based on the new Figure-of-Merit (FoM) or iterative procedure (IP), and genetic algorithm (GA), in order to have a power transfer efficiency equal to 15% and 94.18 % respectively for a separation distance d = 12cm.

Adaptive Impedance Matching Scheme for Magnetic MIMO Wireless Power Transfer System

In coupled magnetic resonance (CMR) wireless energy transfer systems, the energy transfer power is low and the power transfer efficiency changes with the coil position. One reason for this reduction in power and efficiency is the impedance mismatching (IM) between the Tx and Rx coils; achieving impedance matching for multiple-input multiple-output (MIMO) CMR IM wireless power transmission (WPT) is quite complex due to the uncertainty in the number of coils and the interaction between coils. In this paper, we provide an analytical model of MIMO CMR which fully formulates the complex relationship between multiple Tx and Rx channels. Then, we design an impedance matching network (IMN) for MIMO CMR and derive an optimal IM solution. Base on this solution, we also develop an adaptive impedance matching scheme to control IMN, based on an automatic analysis of MIMO CMR system; the resulting control scheme achieves optimal values for transmission power and efficiency through IMN and coil selection. The simulation results indicate that the scheme is able to automatically adjust the impedance matching network according to the changes of the relative positions between Tx and Rx coils to achieve high energy transfer power and efficiency.

Multi-User Energy Beamforming for Different Energy Requests

Energy beamforming takes center stage in radio frequency (RF)-enabled wireless energy transfer (WET) systems. In this letter, we study multi-user energy beamforming to minimize the overall charging time for energy harvesting users (EHUs) with different energy requirements. In order to lessen the cost and power consumption by reducing the required RF chains, it is of consequence to figure out low-rank optimal energy beamforming. By analyzing an upper bound on the rank of a minimum-rank solution, we develop a method to figure out low-rank optimal energy beamforming from the formulated semi-definite programming problem. Our simulation results exhibit the proposed energy beamforming considerably reduces the charging time required until all the requests are met. We also reveal that the capacity achieving precoder for multicasting transmission is a special case of the proposed energy beamforming solution.

RSS-Based Channel Estimation for IRS-Aided Wireless Energy Transfer System

Although intelligent reflecting surface (IRS) is regarded as a promising solution to enhance the efficiency of wireless energy transfer (WET), the acquiring of channel state information is a crucial challenge for the system in which a training sequence for channel estimation is sent by low-power Internet-of-Things (IoT) devices. In this article, an IRS-aided multidevice WET system is considered. To overcome the limitation in channel estimation, we propose a received power-based channel estimation scheme that can be easily implemented and scalable in wirelessly empowered IoT devices. Specifically, at every single time slot, each device measures the received power of a randomly generated radio-frequency signal and feeds it back to the transmitter. We formulate a channel estimation problem to use the history of received power measurements based on the maximum-likelihood estimation using the phase retrieval framework and temporal channel evolution model. Moreover, we propose an algorithm that can be employed to obtain the stationary solution for the channel estimation problem, which is based on the inexact block coordinate descent method. We also perform algorithm modification to deal with the special case in which the transmitter-IRS channel is available. The simulation results show that the performance of the proposed algorithm approaches the upper bound as the channel slowly changes, although the proposed channel estimation protocol requires only one scalar value feedback.