Wireless Energy Transfer Research Articles

Evaluation Method for Underwater Ultrasonic Energy Radiation Performance Based on the Spatial Distribution Characteristics of Acoustic Power.

In recent years, underwater wireless ultrasonic energy transmission technology (UWUET) has attracted much attention because it utilizes the propagation characteristics of ultrasound in water. Effectively evaluating the performance of underwater ultrasonic wireless energy transmission is a key issue in engineering design. The current approach to performance evaluation is usually based on the system energy transfer efficiency as the main criterion, but this criterion mainly considers the overall energy conversion efficiency between the transmitting end and the receiving end, without an in-depth analysis of the characteristics of the distribution of the underwater acoustic field and the energy loss that occurs during the propagation of acoustic waves. In addition, existing methods focusing on acoustic field analysis tend to concentrate on a single parameter, ignoring the dynamic distribution of acoustic energy in complex aquatic environments, as well as the effects of changes in the underwater environment on acoustic propagation, such as spatial variability in temperature and salinity. These limitations reduce the usefulness and accuracy of models in complex marine environments, which in turn reduces the efficiency of acoustic energy management and optimization. To solve these problems, this study proposes a method to evaluate the performance of underwater ultrasonic energy radiation based on the spatial distribution characteristics of acoustic power. By establishing an acoustic power distribution model in a complex impedance-density aqueous medium and combining numerical simulation and experimental validation, this paper explores the spatial variation of acoustic power and its impact on the energy transfer efficiency in depth. Using high-resolution spatial distribution data and actual environmental parameters, the method significantly improves the accuracy of the assessment and the adaptability of the model in complex underwater environments. The results show that, compared with the traditional method, this method performs better in terms of the accuracy of the acoustic energy radiation calculation results, and is able to reflect the energy distribution and spatial heterogeneity of the acoustic source more comprehensively, which provides an important theoretical basis and practical guidance for the optimal design and performance enhancement of the underwater ultrasonic wireless energy transmission system.

Effect of cutting tools and dynamic primary compensations on the working performance of contactless energy transfer system for rotary ultrasonic machining

In rotary ultrasonic machining, contactless energy transfer (CET) unit transmits electric energy from an ultrasonic power supply to a transducer, which converts the energy into ultrasonic vibration of the tool. Compensation enhances this transmission efficiency. However, the tool varies under different working conditions, changing the working performance of contactless energy transfer system (CETS), and fix compensation decreases CETS working performance under different tool parameters. To investigate the impact of tool size and dynamic compensations on CETS working performance, the equivalent-circuit models of CETS with dynamic primary compensations are developed, including dynamic primary series and parallel compensations, and examines the effect of tool on the transducer parameters. Subsequently, the effect of dynamic primary compensations and their variations on the CETS frequency characteristics, the influence of tool parameters and dynamic primary compensation variations on CETS transfer performance, and the sensitive analysis of CETS transfer performance on tool parameters and dynamic primary compensations are investigated. Finally, the experiment is conducted to validate the effects of tool and dynamic primary compensations, and the experimental results are consistent with the analysis above. Furthermore, the experiment also shows that a large tool extension can ensure the energy transmission of cutting tool, the dynamic primary series and parallel compensations are suitable options considering the stable output of ultrasonic power supply and load detection of transducer, respectively.

Voice interactive information metasurface system for simultaneous wireless information transmission and power transfer

Intelligent voice interaction offers a flexible and powerful way to connect individuals with smart devices beyond our expectations. The real-time nature of voice communication enables smart devices to comprehend the user language, execute the corresponding instructions, and facilitate seamless communications, transforming our lives in unprecedented ways. Owing to self-adaptive and reprogrammable functionalities, information metasurface (IMS) opens up a new avenue for smart home and smart cities. To further enhance the intelligence of IMS, we propose an IMS system via intelligent voice interaction and information processing. The voice interaction enables the efficient remote control on the IMS in a flexible, convenient, touchless manner. Leveraging speech recognition, speech synthesis, target detection, and communication technologies, the IMS system achieves automatic beam manipulation capabilities for wireless information transmissions and wireless power transfers. The IMS system is designed to operate in two distinct modes: instruction mode, wherein the user instructs the operations, and autonomous mode, wherein the automatic detections govern the actions, in which seamless mode switching through the voice commands is supported. Users can flexibly achieve precise control over the functions of the intelligent metasurface system through voice interaction at a distance, without the need for close-range manual touch control, which greatly simplifies the operation difficulty and is particularly suitable for remote control and complex application scenarios. A series of experiments, including wireless video transmissions and wireless power transfers are conducted to demonstrate the flexibility and convenience of the IMS system. The incorporation of intelligent voice interaction technology with the IMS presents a novel paradigm for the applications of programmable and information metasurfaces.

A soft computing algorithmic technique for circuital analysis of a wireless mobile charger

Wireless energy transfer is emerging as a promising technology for mobile devices because it enhances rapid charging without requiring conventional cables. In this paper, a wireless mobile charger circuit was designed and simulated, the data obtained thereof was used to train an artificial neural network (ANN) using Levenberg-Marquardt (LM) algorithm. The result obtained was validated against that obtained when trained with regular scaled conjugate algorithm. Analysis of the results showed that the proposed technique remains a viable technique for rapidly analyzing several parts of the wireless mobile charger circuit for design and educational purposes, without always executing computationally intensive and time-consuming simulations.

Load voltage study of LCC-S type wireless energy transmission system based on phase shift control

Abstract When the light load is applied in an LCC-S type wireless power transmission (WPT) system, the system does not have constant voltage characteristics, which affects the normal use of power equipment. If a DC/DC converter is used to regulate the voltage at both ends of the load to keep it constant, it will increase the size and cost of the system, and the efficiency is also reduced. For this reason, in this paper, phase-shift control is carried out based on the LCC-S type WPT system, and the LCC-S resonant compensation network is first modeled and analyzed in terms of its working principle. Then, the principle of phase-shift control is analyzed, the relationship between the drive signal phase-shift angle and the load voltage in the phase-shift control is deduced, and finally, a simulation model is built in Matlab/Simulink to verify the correctness of the control strategy.

CSCT: Charging Scheduling for Maximizing Coverage of Targets in WRSNs

In recent years, wireless rechargeable sensor networks (WRSNs), as a crucial technology in cyber-physical-social systems (CPSSs), have gradually become a hotspot of research, with the development of wireless energy transmission technology. In previous works, the objective is to maximize the survival rate of sensor nodes. However, in this article, we focus on maintaining more targets. First, it details the charging scheduling problem of maximizing coverage of targets (CoT) in on-demand charging architecture of WRSNs. Also, the problem is formalized as a multiple-objective optimization problem, which aims at maximizing the CoT and the energy efficiency simultaneously. After that, the charging scheduling for maximizing coverage of targets (CSCT) scheme is proposed to achieve the above objectives. Then, the problem is reformulated as a Deadline-TSP problem that is NP-hard. To address this problem, we design an energy predictive model and propose the CSCT with an n-path (n-CSCT) scheme that has an O(|N|ⁿ) computational complexity. In addition, the resurrection of sensor nodes is considered in this article. Thus, the n-CSCT with node resurrection (n-CSCT-R) scheme is proposed for this case. Finally, we validate the effectiveness of the proposed schemes via extensive simulations.

Massive Wireless Energy Transfer Without Channel State Information via Imperfect Intelligent Reflecting Surfaces

Massive Wireless Energy Transfer Without Channel State Information via Imperfect Intelligent Reflecting Surfaces

Short-packet communications in wireless energy transfer full-duplex IoT networks with deep learning design

Short-packet communications in wireless energy transfer full-duplex IoT networks with deep learning design

Design of Resonant Converter of Trans cutaneous Energy Transfer System to Power Artificial Heart

Wireless technologies have matured to recharge the batteries of consumer devices efficiently. The benefit of the technology is being used by mobile communication devices, personal computation devices, and wearable entertainment devices. The wireless energy transfer techniques employ the transfer of electrical energy between two-tesla coils in surface contact and not by electrical contact through the phenomenon of electromagnetic induction. Many international consortiums have made guidelines for designing and manufacturing these devices. However, for active implantable medical devices such as artificial hearts, a large amount of electrical energy usually in the range of 15W to 30W needs to be transferred across the skin at a depth of 10mm to 30mm. The design needs to be optimized for maximum power transfer with the highest possible efficiency. Any loss in power will be reflected as heat energy and cause burns and tissue death. A transcutaneous energy transfer system is such type of wireless energy transfer mechanism across the skin to power implanted life-saving devices. In this paper, the design of a resonant converter and its performance is investigated to wirelessly transfer electrical power up to a tissue thickness of about 25mm.

New energy vehicle technology research - Charging technology

In recent years, Chinas economic development is becoming more and more rapid, leading to the increasingly serious pollution emission problem of traditional fuel vehicles. In order to solve the environmental problems, the transformation of automobiles has become an urgent problem. At the present stage, electric vehicles are also widely concerned by all sectors of society because of their low carbon emissions, energy saving and low use cost. With the rapid growth of electric vehicle sales, the demand for charging piles is rising, and the mainstream charging facilities for new energy vehicles are still in short supply. Therefore, we need to focus on efficient wireless charging to solve the major problems in the current electric vehicle industry. This paper analyzes the wireless dynamic energy transmission technology, extending the service life of the battery, how to reduce the cost, the optimization of coil parameters design, the offset of transmission coil and receiving coil, foreign body detection and overheating problems.

Wireless Power Transfer Efficiency Optimization Tracking Method Based on Full Current Mode Impedance Matching.

Wireless power transfer (WPT) technology is a contactless wireless energy transfer method with wide-ranging applications in fields such as smart homes, the Internet of Things (IoT), and electric vehicles. Achieving optimal efficiency in wireless power transfer systems has been a key research focus. In this paper, we propose a tracking method based on full current mode impedance matching for optimizing wireless power transfer efficiency. This method enables efficiency tracking in WPT systems and seamless switching between continuous conduction mode and discontinuous mode, expanding the detection capabilities of the wireless power transfer system. MATLAB was used to simulate the proposed method and validate its feasibility and effectiveness. Based on the simulation results, the proposed method ensures optimal efficiency tracking in wireless power transfer systems while extending detection capabilities, offering practical value and potential for widespread applications.

Far-Field Wireless Power Beaming to Mobile Receivers Using Distributed, Coherent Phased Arrays: A Review of the Critical Components of a Distributed Wireless Power Beaming System

Far-Field Wireless Power Beaming to Mobile Receivers Using Distributed, Coherent Phased Arrays: A Review of the Critical Components of a Distributed Wireless Power Beaming System

Novel Approach towards a Fully Deep Learning-Based IoT Receiver Architecture: From Estimation to Decoding

As the Internet of Things (IoT) continues to expand, wireless communication is increasingly widespread across diverse industries and remote devices. This includes domains such as Operational Technology in the Smart Grid. Notably, there is a surge in resource-constrained devices leveraging wireless communication, especially with the advances of 5G/6G technology. Nevertheless, the transmission of wireless communications demands substantial power and computational resources, presenting a significant challenge to these devices and their operations. In this work, we propose the use of deep learning to improve the Bit Error Rate (BER) performance of Orthogonal Frequency Division Multiplexing (OFDM) wireless receivers. By improving the BER performance of these receivers, devices can transmit with less power, thereby improving IoT devices’ battery life. The architecture presented in this paper utilizes a depthwise Convolutional Neural Network (CNN) for channel estimation and demodulation, whereas a Graph Neural Network (GNN) is utilized for Low-Density Parity Check (LDPC) decoding, tested against a proposed (1998, 1512) LDPC code. Our results show higher performance than traditional receivers in both isolated tests for the CNN and GNN, and a combined end-to-end test with lower computational complexity than other proposed deep learning models. For BER improvement, our proposed approach showed a 1 dB improvement for eliminating BER in QPSK models. Additionally, it improved 16-QAM Rician BER by five decades, 16-QAM LOS model BER by four decades, 64-QAM Rician BER by 2.5 decades, and 64-QAM LOS model BER by three decades.

Optimizing beamforming in IoT-WET: A symbiotic-based approach under imperfect channel state information

This study delves into the energy optimization problem in low-power Internet of Things (IoT) networks utilizing wireless energy transfer (WET) technology. In such IoT systems, conventional optimization schemes relying on complete knowledge of channel state information (CSI) are often irrelevant for practical implementation due to their high complexity and energy consumption. To address this challenge and enhance the fairness of energy harvesting among IoT devices with imperfect CSI, we propose a novel beamforming design based on the symbiotic organisms search (SOS) algorithm. Through comprehensive numerical analysis, we demonstrate the effectiveness of our proposed scheme in terms of computational complexity, convergence speed, and energy harvested at each IoT device. The results highlight the significant advantages of our approach compared to conventional methods, paving the way for practical and efficient energy optimization in IoT networks.

Highly Efficient and Stable Organic Photovoltaic Cells for Underwater Applications.

Organic photovoltaic (OPV) technology holds tremendous promise as a sustainable power source for underwater off-grid systems. However, research on underwater OPV cells is relatively scarce. Here, this gap is addressed by focusing on the exploration and development of OPV cells specifically designed for underwater applications. An acceptor, named ITO-4Cl, with excellent water resistance, is rationally designed and synthesized. Benefiting from its low energetic disorder and an absorption spectrum well-suited to the underwater environment, the ITO-4Cl-based OPV cell achieves an unprecedented power conversion efficiency (PCE) of over 25.6% at a water depth of 1m. Additionally, under 660nm laser irradiation, the cell demonstrates a notable PCE of 31.6%, indicating its potential for underwater wireless energy transfer. Due to the mitigation of thermal effects from solar irradiation, the lifetime of the ITO-4Cl-based OPV cell exceeds 7000h. Additionally, a flexible OPV cell is fabricated that maintains its initial PCE even under exposure to high pressures of 5MPa. A 32.5cm2 flexible module achieves an excellent PCE of 17%. This work fosters a deeper understanding of underwater OPV cells and highlights the promising prospects of OPV cells for underwater applications.

Anti-Offset Multicoil Underwater Wireless Power Transfer Based on a BP Neural Network

Autonomous underwater vehicles (AUVs) are now widely used in both civilian and military applications; however, wireless charging underwater often faces difficulties such as disturbances from ocean currents and errors in device positioning, making proper alignment of the charging devices challenging. Misalignment between the primary and secondary coils can significantly impact the efficiency and power of the wireless charging system energy transfer. To address the issue of misalignment in wireless charging systems, this paper proposes a multiple transfer coil wireless power transfer (MTCWPT) system based on backpropagation (BP) neural network control combined with nonsingular terminal sliding mode control (NTSMC) to enhance further the system robustness and efficiency. To achieve WPT in the ocean, a coil shielding case structure was equipped. In displacement experiments, the proposed multi-transmitting coil system could achieve stable power transfer of 40 W and efficiency of over 78.5% within a displacement range of 8 cm. The system robustness was also validated. This paper presents a new AUV energy supply solution based on MTCWPT. The proposed MTCWPT system can significantly improve the navigation performance of AUVs.

Research on Wireless Power Transfer Method for Intelligent Sensing Device of Non-Directly Buried Distribution Cables

This paper presents a study on the impact of circuit parameters on the transmission of electrical energy in wireless power transfer systems designed for intelligent sensing devices within the urban electric power Internet of Things (IoT). Relying on the essential principles of resonant mutual inductance models, the paper conducts an analytical investigation into the phenomena of power-frequency splitting characteristics, efficiency-frequency splitting characteristics, and efficacy synchronization characteristics within wireless energy transmission technologies. The investigation includes a detailed analysis of a wireless power transfer system model operating at 100 kHz, delineating how varying circuit parameters influence the system’s efficiency. Via the utilization of graphical software and computational programming for simulation modeling, this research delved into the dynamics between key parameters such as equivalent load and coupling coefficient and their influence on distinct splitting phenomena. This rigorous approach substantiated the validity of the proposed power-frequency and efficiency-frequency splitting characteristics outlined in the study. Based on the analytical results, it is shown that selecting an appropriate equivalent load or utilizing impedance matching networks to adjust the equivalent load to a suitable size is crucial in consideration of the system’s output power, voltage withstand level, and transmission efficiency. The research findings provide a theoretical basis for the design of wireless power supply systems for non-directly buried cable front-end sensing devices.

Directed high-energy infrared laser beams for photovoltaic generation of electric power at remote locations

Transferring energy without transferring mass is a powerful paradigm to address the challenges faced when the access to, or the deployment of, the infrastructure for energy conversion is locally impossible or impractical. Laser beaming holds the promise of effectively implementing this paradigm. With this perspective, this work evaluates the optical-to-electrical power conversion that is created when a collimated laser beam illuminates a silicon photovoltaic solar cell that is located kilometers away from the laser. The laser is a CW high-energy Yb-doped fiber laser emitting at a center wavelength of 1075 nm with ∼1 m2 of effective beam area. For 20 kW illumination of a solar panel having 0.6 m2 of area, optical simulations and thermal simulations indicate an electrical output power of 3000 W at a panel temperature of 550 K. Our investigations show that thermo-radiative cells are rather inefficient. In contrast, an optimized approach to harvest laser energy is achieved by using a hybrid module consisting of a photovoltaic cell and a thermoelectric generator. Finally, practical considerations related to infrared power beaming are discussed and its potential applications are outlined.

Impedance Circle Modeling and Dynamic Characteristics Analysis of Contactless Energy Transfer System Under Load Variations in Rotary Ultrasonic Machining

In rotary ultrasonic machining, contactless energy transfer (CET) is developed to transmit energy to the transducer at the series resonant frequency or resonant frequency of the transducer. Specifically, during energy transmission, variations in working conditions such as variable axial forces will change the load of the transducer and introduce undesired dynamic effects into the contactless energy transfer system (CETS). In order to explore the connections between these variations and the working performance more directly and theoretically, a new theoretical model—CETS impedance circle is proposed in this paper to reflect the CETS dynamic characteristics, including the CETS frequency characteristics and the relationships between CETS transfer performances at different frequencies under load variations. With the developed theoretical model, the effect of load variations on the trends of CETS impedance circle is investigated. Moreover, based on the impedance circle and its trends, the CETS frequency characteristics, the effect of primary series compensation, and a comparison of the transfer performances at the two working frequencies are theoretically studied. Finally, the CETS impedance circle theories are experimentally verified, and the experimental results are consistent with the analysis of the theoretical model.

Review of energy supply techniques for ice in-situ thermal mining in lunar permanently shadowed regions

The Moon's polar regions have abundant water ice resources. The mining and utilization of lunar polar water ice could serve as a propellant and survival resource for human exploration of deep space. The concept of thermal mining has been proposed to extract water ice resources. There are advantages and disadvantages to different mining methods. The energy problems faced by in situ resource utilization on the Moon are of great concern. The electrolysis of water and the heating of weathered layers require a continuous supply of energy. Wired energy transfer at the lunar poles would be very costly for launching conductors from Earth to the Moon. Wireless energy transfer technology is also well-developed today and has promising applications in the energy supply of lunar thermal mining. This paper describes the different methods of thermal mining and the various ways of supplying energy using solar energy for thermal mining.