Wireless Power Transmission Technology Research Articles

Camera-Based Safety System for Optical Wireless Power Transmission Using Dynamic Safety-Distance

This paper introduces a new safety approach for Optical Wireless Power Transmission (OWPT), a technology that is integral to the new kinds of Wireless Power Transmission technology (WPT). It starts from the fundamental configuration of the current OWPT system, addressing the safety concerns related to lasers by involving laser irradiation hazards, laser exposure regulation and guidelines, and a comparison with other safety methods. A camera-based OWPT safety system focused on the emission control of the light source is proposed, and it utilizes a depth camera and finely tuned computer vision-based control program. Through meticulous system design and experiments, the proposed system can detect moving objects in a limited indoor environment and control the laser/LED light transmission according to the object’s velocity dynamically. Various functions and exclusive improvements towards OWPT operation are mentioned, and Dynamic Safety-Distance is proposed as the core mechanism of the safety system. Through on-site experiments, indoor safety control and system operation’s evaluation are discussed, acknowledging both the advantages and limitations of the proposed safety system. This paper concludes with suggestions for further developments in camera-based OWPT safety incorporating the concept of Automatic Emission Control.

Mirror Symmetry Coils for Foreign Object Detection and Location with Wireless Power Transmission

Background: Wireless power transmission technology effectively avoids safety issues caused by accidental contact, wire aging, and friction. However, due to the presence of foreign objects, other severe accidents such as fire hazard can occur, and the charging system can be interfered with and even damaged by the foreign objects. background: As a new charging technology, the wireless power transmission (WPT) technology has shown some favorable application prospects on safety, reliability, and convenience. Method: Therefore, this paper proposes (MSD) mirror symmetry detection coils to detect and locate foreign objects. First, we conduct theoretical analysis and derive formulas to validate our proposed method. Next, we employ ANSYS Maxwell to simulate the (WPT) wireless power transmission system, considering various sizes and materials of foreign objects and comparing them to a system without foreign objects. Result: Furthermore, we conducted experiments using mirror symmetrical detection coils to detect and locate foreign objects, providing additional verification for our proposed method. Conclusion: The simulation and experimental results show that the proposed method of mirror symmetry detection coils can effectively identify and locate the foreign objects.

The application of beam-forming technology of wireless power transfer in IIoT (industrial internet of things)

When building the Industrial Internet of Things (IIoT), it is estimated that over 60% of the cost is spent on wiring and installation. The application of wireless data transmission can eliminate some of the cable connections, and the use of wireless technology for power transmission can undoubtedly avoid even more wiring. However, in practice, traditional wireless power transmission technology has disadvantages such as low efficiency and poor reliability. The introduction of beamforming technology can improve the performance of wireless charging in terms of transmission efficiency and transmission distance. The introduction of beamforming technology can improve the performance of wireless charging in terms of transmission efficiency and distance. Considering the influence of the possible relative displacement between the transmitting and receiving devices on the beamforming during the charging process, a charging process model based on beamforming is developed in this paper using ANSYS for a one-to-one dynamic wireless charging scenario. ANSYS simulation software is used to simulate the array antennas, to investigate the electromagnetic field relationship between the antennas and to analyse the effect of beamforming on the efficiency and stability of the system. Combined with the characteristics of the array antennas shown in the simulation results, the use of beamforming in transmitting antennas in wireless power transmission systems can greatly improve the directivity, effectiveness and interference immunity of the system.

The state-of-the-art wireless power transmission technology in electric vehicles

Since the 21st century, people have been paying attention to energy and environmental protection issues, and the world is accelerating the development and promotion of new energy vehicles. At present, the mainstream charging method of new energy vehicles is wired charging, but this charging method has certain safety hazards. So using wireless charging technology can effectively make up for this shortcoming. This paper starts with the development history of wireless charging technology, and expounds the birth and development of wireless charging technology. Then three common wireless charging technologies are introduced. This article will introduce the three wireless charging technologies from their principle, topology and advantages and disadvantages. Secondly, by comparing the three wireless charging technologies, it is concluded that IPT technology is the most mature and widely used technology at present, at the same time, CPT technology is also promising. Finally, the technical challenges and development prospects of wireless charging technology are discussed.

A Novel Method of Wireless Micro Energy Transmission Based on MEMS Micro Coil.

Based on current implantable devices, a battery's rigidity and large size makes it prone to immune rejection and wound incisions. Additionally, it is limited by its finite lifespan, which hinders long-term usage. These limitations greatly restrict the development of implantable medical device systems towards miniaturization and minimally invasive approaches. Consequently, obtaining high-fidelity and stable biological signals from the target tissue area of the organism remains challenging. Therefore, there is a need to develop wireless power transmission technology. In this paper, we propose a wireless micro energy transfer method based on MEMS micro coils for charging implantable devices. Through simulation calculations, we first investigate the influence of coaxial distance, horizontal displacement, and rotation angle between the MEMS micro coil and the transmitting coil on power transmission. Subsequently, we utilize micro nanofabrication technology to create a MEMS micro spiral copper coil with a line width, thickness, and spacing of 50 µm and a total of five turns. Finally, we conduct wireless power transmission tests on the coil. The results show that, when the transmitting coil and the receiving coil are 10 mm apart and the operating frequency is 100 kHz, the power of the wireless power transmission system reaches 45 µW. This power level is sufficient to meet the power supply requirements of implantable pacemakers. Therefore, this technology holds great potential for applications in the field of wireless power transmission for implantable medical devices, including pacemakers and brain neurostimulators.

Revolutionizing Connectivity: The Breakthrough of Batteryless Mouse Using Magnetic Resonant Coupling for Communication Devices

With the rapid development of electronic technology and information technology, personal computer has gradually become the public's office or entertainment tools, which also makes the computer mouse a widely used tool. However, most computer mouse on the market today come with batteries. In this context, it is necessary to design a batteryless mouse that without using power supply such as battery. In view of such demand, on the basic of theoretical analysis, this paper summarizes and designs a classical wireless transmission structure – magnetic resonant coupling and antenna that used to transmit and received power for communication devices. In order to understand the operation of wireless power transmission technology, the paper analysed antenna construction and wireless power transmission technology. The basic design parameters of the axial mode helical antenna structure are also explained. Finally, by using CST STUDIO software, axial mode helical antenna with gain of 6.45 dBi was obtained. The system's output voltage is successfully simulated at 1.516 V that can powered up the computer mouse.

Design of Underwater Wireless Power Transmission System Based on Inductive Coupling

Human exploration of the ocean is inseparable from reliable ocean observation equipment. Wireless power transmission technology can supply power to the receiving end in a non-contact manner, saving complicated cable plugging and unplugging. Due to the conductivity of seawater, a certain amount of eddy current loss will be generated during wireless power transmission, reducing the output power and transmission efficiency. This paper designs a wireless power transmission system suitable for underwater scenes, and in this paper, the operational characteristics of the system are analyzed. At the same time, the transmission capability of the system in the air is studied, and the influence of several key parameters such as resonance frequency on the output power and transmission efficiency is analyzed. On this basis, combined with the calculation method of eddy current loss in seawater, the system transmission efficiency in seawater is calculated, which provides a reference for selecting the operating frequency. Finally, a coupler design scheme that is easy to dock with underwater devices and has a good electromagnetic shielding effect is given, and its transmission capability and performance under misalignment are analyzed through finite element simulation. According to the design plan, a prototype is built and experiments are carried out in air and simulated seawater environments. The experimental results verify the correctness of the theory.

Analysis and Experiment of Laser Energy Distribution of Laser Wireless Power Transmission Based on a Powersphere Receiver

Laser wireless power transmission (WPT) is one of the most important technologies in the field of long-range power transfer. This technique uses a laser as a transmission medium instead of conventional physical or electrical connections to perform WPT. It has the characteristics of long transmission distance and flexible operation. The existing laser wireless power transmission system uses photovoltaic cells as a receiver, which convert light into electricity. Due to the contradiction between the Gaussian distribution of laser and the uniform illumination requirements of photovoltaic cells, the laser wireless power transmission technology has problems such as low transmission efficiency and small output power. Therefore, understanding the energy distribution changes in the laser during transmission, especially the energy change after the laser is transmitted to each key device, and analyzing the influencing factors of the energy distribution state, are of great significance in improving the transmission efficiency and reducing the energy loss in the system. This article utilizes the optical software Lighttools as a tool to establish a laser wireless power transmission model based on a powersphere. This model is used to study the energy distribution changes in the laser as it passes through various components, and to analyze the corresponding influencing factors. To further validate the simulation results, an experimental platform was constructed using a semiconductor laser, beam expander, Fresnel lens, and powersphere as components. A beam quality analyzer was used to measure and analyze the laser energy distribution of each component except for the powersphere. The output voltage and current values of various regions of the powersphere were measured using a multimeter. The energy distribution of the powersphere was reflected based on the linear relationship between photo-generated current, voltage, and light intensity. The experimental results obtained were in good agreement with the simulation results. Simulations and experiments have shown that using a beam expander can reduce divergence angle and energy loss, while employing large-aperture focusing lens can enhance energy collection and output power, providing a basis for improving the efficiency of laser wireless power transfer.

An Optimized Power-Efficiency Coordinated Control Method for EVs Charging and Discharging Applications

Recently, bidirectional wireless power transmission (BD-WPT) technology has been increasingly used in electric vehicles (EVs) charging and discharging applications to realize interactive energy feedback between EVs and the power grid. Although the efficiency of BD-WPT system has been impressively improved, it still heavily relies on complex control methods. This paper proposes a simple but effective control method to achieve maximum efficiency with zero reactive power. Specifically, a resonance judgment and phase synchronization (RJ&PS) network is employed to ensure the resonance performance and synchronization of the bilateral control signals, which realizes the stead auto-starting of the secondary side and guarantees the disentanglement between power control processes as well. With the help of voltage ratio design and symmetric phase shift between bilateral inverters, the optimization efficiency is well achieved. The results of the experiment and simulation match well, showing the effectiveness of the proposed method in this paper.

Design and analysis of wireless power supply system for high‐voltage transmission lines across 500‐kV insulator distance

AbstractThe energy harvesting of ultra‐high voltage transmission lines and wireless power transmission technology are effective means to solve the stable energy supply of outdoor tower equipment. However, there are inevitably technical problems such as long transmission distance, weak coupling, and parameter sensitivity. In this paper, an effective design approach for a power demand‐oriented long‐distance wireless power transmission system is proposed. With the goal of transmitting power, a system equivalent parameter model is established to address the sensitivity of design parameters for the point‐to‐point long‐distance wireless power transmission system, and the main influencing factors that lead to system power transmission failure are analyzed. To effectively address the impact of high‐sensitivity parameters, a fast‐tuning method with redundant capacitance matrix compensation is proposed, which improves the deviation problem in system parameter design, improves the efficiency of offset parameter matching, and analyzes the impact of wireless energy transmission systems on high‐voltage insulator strings. Finally, an experimental platform was constructed to achieve power transmission at a distance of not less than 5 m at a resonant frequency of 50 kHz. The transmission efficiency met the design expectations and verified the effectiveness of the analysis.

Spatial Azimuthal Misalignment Characteristics of High-Temperature Superconducting Wireless Power Transmission Systems

Magnetically coupled resonant wireless power transmission technology (WPT) based on high-temperature superconducting (HTS) coils has gained wide popularity due to its low impedance and high-quality factor Q value characteristics. This technology has greatly improved the energy transfer performance of wireless power transmission (WPT) systems. However, practical applications of conventional WPT, such as wireless charging of autonomous underwater vehicles at mooring points, often encounter spatial misalignment issues due to the complex ocean environment and ocean currents. Nonetheless, few studies have investigated the spatial misalignment of HTS WPT systems, particularly the angular misalignment. This paper presents a solution to address this problem by constructing magnetically coupled resonant wireless energy transmission systems based on HTS coils and copper coils. The study analyzes the relationship between the transmission efficiency of the WPT system and the received power of the load with respect to the spatial orientation of the coil. The performance of the superconducting coil and copper coil WPT systems is compared. The experimental results demonstrate that, under the same spatially misaligned conditions, the WPT system using HTS coils can significantly improve the transmission efficiency and load power compared to the conventional copper WPT system. Moreover, simultaneous adjustment of the lateral misalignment distance and different orientation deflection angles can improve the transmission efficiency and smooth load output power of the high-temperature superconducting WPT system.

RF Energy Harvesting and Wireless Power Transfer for Energy Autonomous Wireless Devices and RFIDs

Radio frequency (RF) energy harvesting and wireless power transmission (WPT) technologies —both near-field and far-field—have attracted significant interest for wireless applications and RFID systems. We already utilize near-field WPT products in our life and it is expected that RF EH and far-field WPT systems can drive the future low-power wireless systems. In this article, we initially present a brief historical overview of these technologies. The main technical challenges of rectennas and WPT transmitters are discussed. Furthermore, this paper presents the recent advances on the development of these technologies, including the possibility of powering RFID systems through the millimeter wave power from 5G networks, the trends in flexible rectennas design and the technological developments on the simultaneous wireless information and power transfer (SWIPT).

Investigation on Induced Energy Extraction from High-Voltage Transmission Lines Based on Three-Coil WPT Systems

In order to realize an online power supply, this article develops an explicit design of induction power extraction technology combined with wireless power transmission (WPT) technology. Unlike the power supply mode of traditional batteries of online monitoring devices of high-voltage transmission lines, this technology solves the short battery life cycle problems. First, the principle of induction power extraction is analyzed. Based on the equivalent circuit of the mutual inductance model, expressions of induction power extraction without and with core saturation are derived, respectively. According to the current transformer (CT) magnetic coupling diagram, the open-circuit voltage of the secondary side of the CT is deduced. Therefore, the CT material and size could be selected. The CT coupling model is used to equivalent the current transformer to the ideal voltage source. Then, the four basic topological spaces of the magnetic coupling resonant WPT system are analyzed and calculated, and the efficiency of the SS topology WPT system is analyzed. Furthermore, aiming at long-distance power transmission, this article described the building of a three-coil WPT system and the analysis of the corresponding transmission efficiency and output power expression. With the aid of Maxwell, the technology proposed is simulated based on a 110 kV high-voltage transmission line with 1.2 m as the transmission distance of the system. Finally, the influence of a coupling coefficient and load resistance on the transmission characteristics of the multicoil system is obtained. Consequently, the simulation results with a system output power of 14.4 W verify the effectiveness of the technology.

Boosting output performance of triboelectric nanogenerator based on BaTiO3:La embedded nanofiber membrane for energy harvesting and wireless power transmission

To boost output charge density for achieving high-performance triboelectric nanogenerator (TENG), increasing dielectric constant of triboelectric materials is considered as an important strategy. Herein, a high-performance TENG is fabricated based on BaTiO3:La-embedded poly (vinylidene fluoride-trifluoro-ethylene) (PVDF-TrFE) nanofiber membrane (NM) (BLPT-NM) for energy harvesting and wireless power transmission. The obtained BLPT-NM shows an enhanced electronegativity and a significant increase in dielectric constant (38.8 at 10 kHz) through facile electrospinning and proper concentration optimization of BaTiO3:La. The fabricated single-electrode-mode TENG based on BLPT-NM (3 × 3 cm2) demonstrates excellent output performance with power density of 2.52 W m–2 (ƒ=1.5 Hz) and triboelectric charge density of 87.3 μC m−2, which are significantly increased by more than 11- and 3-fold, respectively, in comparison with those of the TENG based on pristine PVDF-TrFE-NM. More importantly, a wireless power transmission for transmitting electrical signals is successfully achieved via Maxwell’s displacement current generated by the BLPT-NM based TENG after directly harvesting ambient biomechanical energy. Furthermore, the wirelessly received signals can trigger the operation of some electronics in real time. This work demonstrates an effective strategy for boosting the output performance of TENG and paves a new route to further promote the development of wireless power transmission technologies.

Applications of negative permeability metamaterials for electromagnetic resonance type wireless power transfer systems

With the development of electric drive systems such as unmanned aerial vehicles and electric vehicles, the charging problem of power supply devices has become increasingly prominent. However, the traditional charging method requires physical circuits, which makes it impossible to achieve freedom of the position in actual use. The wireless power transmission technology, which mainly relies on electromagnetic wave to complete energy transmission, is expected to get rid of the restriction of physical space location and solve the problem of charging location, which has great potential in medical treatment, rescue, detection and other fields. However, the low transmission efficiency and short transmission distance caused by electromagnetic field leakage are the two main problems faced by radio energy transmission systems. In general, with the increase of transmission distance, the transmission efficiency will drop sharply. Fortunately, inserting a negative permeability metamaterial with extraordinary electromagnetic characteristics into the transmitting and receiving coils will greatly alleviate this attenuation trend and can also shield electromagnetic radiation to a certain extent. In this paper, some experiments of negative permeability metamaterials used in electromagnetic resonance type wireless power transfer systems are summarized for reference.

Wireless power transmission technologies

The article consists of three parts. The analysis of existing technologies of wireless power transfer (WPT) is carried out in the first part. It is noted that one of the factors that determines the choice of one or another WPT technology is the distance over which the power is transmitted and the type of electromagnetic (EM) energy used. The essence of WPT technologies in the near zone, Fresnel zone and Fraunhofer zone is explained. A generalized block diagram of the WPT system is presented. Areas of application and trends in the further development of the WPT technologies over short distances using induction and resonance methods, the WPT technologies over long distances, the technology of EM energy harvesting from the surrounding space and its conversion into direct current for powering low-power devices are considered.
 The achievements of the team of the antenna laboratory of the Kharkiv National University of Radio Electronics (KhNURE) in the area of WPT are presented in the second part of the article. Namely, the electrodynamics’ approach is considered which is based on a single idea about the functioning of WPT systems and which include antennas and their circuits and ways of excitation with nonlinear elements. The stages of building a nonlinear mathematical model (MM) of the electrodynamics’ level of the WPT system are presented, according to which the entire WPT system, which generally includes the transmitting subsystem and the receiving subsystem, is considered as a single multi-input antenna system with nonlinear characteristics. The proposed MM provides a complete representation of the WPT systems operation of a wide class and purpose, in which fundamentally different WPT technologies are used.
 The third part of the article presents new results related to continued research. The analysis of the adequacy of the developed MM of WPT system is carried out. The results of simulation of WPT systems with the induction method of energy transfer (near zone) and their comparison with theoretical and experimental data of other authors showed the reliability and universality of the proposed approach and the MM of WPT system developed on its basis.

Review of Crucial Problems of Underwater Wireless Power Transmission

In order to solve the problem of energy supply for underwater equipment, wireless power transmission technology is becoming a new way of underwater power transmission. It has incomparable technical advantages over traditional power supply method, and can effectively improve the safety, reliability, convenience and concealment of power supply for underwater equipment. The WPT has a natural electrical isolation between the primary and secondary sides to ensure safe charging in an underwater environment. This breakthrough technology greatly facilitates power transmission in the deep sea. However, current transmission power and efficiency levels are not at the level of WPT systems in air. Based on the analysis of the development status of underwater wireless power transmission technology, this paper firstly puts forward the challenges of underwater wireless power transmission, and summarizes the electromagnetic coupler structure, underwater docking mode, compensation topology, control method and eddy current loss. The current research hotspots in the field of underwater wireless power transmission are summarized and analyzed. Finally, according to the development trend of technology, the urgent technical problems in underwater wireless power transmission are expounded.

Wireless Power Transmission Technology

In this WPT, the main concept is power transmission without use of wires. In electrical power system, most of losses occurred in transmission & distribution with the use of this concept transmission system to related history of wireless power transmission system also the related Power transfer technology it is technology eliminates the drawbacks of existing wires technology. In this electrical energy transfer by electromagnetic induction is typically magnetic. It will be power transmits transmission wireless energy (WPT).

A Lamb waves-based wireless power transmission system for powering IoT sensor nodes

Sensor nodes (SNs) are widely deployed for condition monitoring within closed thin-walled structures. Conventional wired power supply using cables will affect the structural integrity, and wireless power supply based on inductive coupling will be shielded by metal structures, therefore, neither is desirable. Motivated by these issues, this article presents a Lamb waves wireless power transmission (WPT) technology based on piezoelectric wafer active sensors (PWASs). A PWAS with a diameter of 7 mm was used to excite A0 single-mode Lamb waves on a 1.6 mm aluminum plate at a frequency of 150 kHz for power transmission. Two optimization strategies for the Lamb waves-based WPT system were proposed and designed, including electrical impedance matching and beamforming with a linear PWAS array. The optimization effects of these two methods were analyzed experimentally. By combining these two approaches, the maximum received power is 1.537 mW, which is 384.25 times higher than that without the optimization method. The corresponding transmission efficiency is 0.217%, which is 43.4 times higher than that without the optimization method. A power management circuit was built with a maximum output power of 1.41 mW and a corresponding conversion efficiency of 77.5%. Finally, an internet-of-things (IoT) SN is designed, and a test proves that the proposed WPT system can power IoT SNs.

WPT compensation topology optimized for PV embedded electric vehicle

The incorporation of renewable energy sources into Electric Vehicle (EV) integration systems to charge the onboard charger will result in a significant increase in the number of EV and industrial equipment in the next years. Wireless Power Transmission (WPT) technology is a significant source of operation in the field of power transmission, with enormous potential in a wide range of applications. The resonance phenomenon has lately acquired favor as a method of transferring electricity to a load efficiently across a large air gap. This research presents an efficient L2CL-LCL correction in WPT for obtaining electricity from the PV array and charging the EV’s battery. To demonstrate its advantages, the L2CL-LCL method is compared to the DSLCL compensation method. The system adjusts the transmit current of the primary coil to maintain stable output power, maximize power transfer efficiency, and power transferred to the load using an Improved Weighted Chimp Optimization (IWdCH) algorithm that searches for the coupling coefficient 'k' of the elements of the compensation networks. Finally, the proposed system was implemented in Python power electronics software and its superiority was demonstrated by comparing it to conventional optimization algorithms. It outperforms conventional optimization algorithms in terms of efficiency, with anefficiency of 95 %.