Maximizing Charging Utility for Height-adjustable Directional Pendant Wireless Chargers

Power cannot be efficiently transmitted over long distances using conventional wireless transmission. Although increasing charger power effectively improves charging efficiency, safety concerns include mobile phone heating, long-term health damage caused by electromagnetic waves, and interferences on other precise instruments. This study proposed a remote wireless charging system that utilizes mechanical movement design in zoom lenses to maintain wireless charging system performance and perform charging operations from different positions in a room through the movement between lens groups. Moreover, the Taguchi method was applied in optical design software to identify the optimal factors for performance improvement. The wireless light charging system was optimized using the Taguchi method. In addition, optimization of curvature, thickness, and material were proposed. Three focal lengths were optimized through 18 sets of experimental data to reduce the spherical and comatic aberrations; and modulation transfer function value was improved to enhance the performance of the remote wireless light charging system. The remote wireless light charging system was designed to be used in an indoor space. In general, the system is installed on the ceiling, and mechanical movement function is enabled for the lens. Moving the lens changes the focus of the system. This allows the charging light source to change its original light path and generate a new focal point. The system features three zoom positions: 3 m from the ceiling to the floor, 2 m from the ceiling to the desktop, and 1.5 m from the ceiling to a person standing with a mobile phone. This allows the wireless light charging system to focus on the mobile phone receiver for charging in every corner within the indoor space. The wireless charging system features three focal lengths; the field of view (FOV) values are 0°, 24°, and 34°; the total length of the system is 635.45 mm; and the size of the spot diagram is 20% at various FOV angles at a spatial frequency of 80 lp/mm; and the lateral color was < ± 2 μm. A photodiode with an area of 12.0 mm was used as the receiver, and energy could be effectively received when the spot size was greater than or equal to the receiving area.

The biggest hurdles for the globe throughout the coming decades will be climate change as well as the depletion of fossil fuels. One of the primary causes of climate change is an increase in the concentration of greenhouse gases. As a result, electric vehicles (EVs) have been identified as one of the possible solutions to reducing emissions as well as reliance on fossil fuels. Profitable commercialization and the faster adoption rate of EVs require faster, more cost-effective, and more reliable charging infrastructure. Conversely, several concerns, including such restricted driving range, a shortage with charging stations, battery destruction, and so forth, have been hampering the development of EVs. To alleviate EV range anxiety, it’s also necessary to establish its highly developed charging infrastructure. To confront this same majority of these issues, a wireless charging system (WCS) could be one of the options for charging electric vehicles without a plug. The aim of this article should provide an overview of the main wireless power transfer techniques for charging a battery in an electric vehicle. Besides that, the obstacles and drawbacks of wireless charging technologies, and solutions to overcome these problems all are discussed extensively. Prospective ideas based on wireless electric vehicle charging systems, including “Vehicle-to-Grid (V2G)” as well as “In-wheel” WCS, also are addressed.KeywordsConductive chargingElectric vehicle (EV)Vehicle-to-grid (V2G)Wireless electric vehicle charging system (WEVCS)

Considering a prospect where a driverless electric vehicle (EV) requires an automatic charging system that does not need a person to do anything. In this case, there is a need for a fully automated, fast, safe, cost‐effective, and reliable charging infrastructure that can be used for EVs and other EVs. This infrastructure must also be profitable and allow for quick adoption in electric transportation systems. Wireless charging methods may allow you to understand these characteristics. Wireless power transfer (WPT) is a future technology that offers flexibility, convenience, safety, and the capacity to be automated. Due to its high efficiency and ease of maintenance, resonant inductive wireless charging should get more attention in WPT techniques than other WPT methods. This literature provides an overview of the status of Resonant Inductive Wireless Power Transfer Charging technology, as well as a look at the current and prospects of the wireless EV industry. First, the article provides a brief history of wireless charging technologies, outlining the benefits and drawbacks. Then, the research assists in a comparative analysis of various types of WPT methodologies, control strategies, and compensation networks that have been done so far. The static and dynamic charging procedures, as well as their features, are shown. To increase charging power, a novel approach to the usage of superconducting materials in coil designs is examined, and their potential influence on wireless charging is highlighted. The detailed role and importance of power electronics, as well as the many types of converters utilized in diverse applications, are highlighted. The batteries and their management systems, as well as numerous WPT difficulties, are also discussed. Different trades are investigated, including cyber security economic consequences, health and safety, foreign object identification, and the effect and influence on the distribution grid. This article also highlights the opportunities and challenges associated with wireless charging systems. We anticipate that our effort will contribute to the advancement of WPT system research and development.

This work describes the implementation of an RF based wireless charging system using RF transmitting and receiving modules. The objective of this work is to implement a system that has the ability to interact and communicate wirelessly within short range. This mobile wireless charging switching system consists of two sections, the transmitting and the receiving section. Each section was interfaced to 433MHz transmitting and receiving modules. The transmitter section of the wireless mobile charging system sends bursts of 433MHz signal through push button switch which is used in the initiation of the charging process to the receiver; when this signal is received by the receiver, it activates a relay which in turn switches on the internal power that comprises the backup battery, DC-to DC converter via a Universal Serial Bus (USB) port to the mobile device to begin charging. This work was able to achieve a wireless transfer of power for distance of about one metre between the transmitter and the receiver.Keywords: wireless charging, radio frequency radiation, electromagnetic induction, inductive coupling, microcontroller,

Along with an increasing amount of electrified vehicles worldwide, an appropriate charging infrastructure has to be implemented to ensure a successful structural transformation in the transport sector. Commonly, conducted charging is used for fast charging using direct current and charging powers up to 350 kW or alternating current for e.g. private charging with 11 kW. Furthermore, wireless charging technologies are in development for a potentially higher level of automation of the charging process, especially. Thus, this technology has to be considered in context with automated driving functions, to provide a completely autonomous vehicle usage. As these wireless charging systems use two air-coupled, planar coils for energy transmission at an operating frequency between 79 kHz and 90 kHz, the electromagnetic emissions become an important issue. Especially the magnetic field emissions between 9 kHz and 30 MHz are the main focus of the current standardization process. This work focusses on the magnetic field emissions of a wireless charging system considering the disturbance currents, which are responsible for the field generation. Beside this, the impact of the measurement environment on these emissions is investigated. As the measurements are commonly conducted in a semi-anechoic chamber, while for wireless charging systems the typical area of application is e.g. a parking place with nonconductive floor and walls around, comparative measurements are executed to show the effects of the environment on the measurement results

This project proposes improving the technology level of the three-phase wireless charging technology developed at Oak Ridge National Laboratory (ORNL). Successful commercialization of wireless charging systems require that they meet strict safety standards for electromagnetic field emissions and interoperability with other wireless charging technology. ORNL has previously demonstrated a 50kW three-phase wireless power transfer system with 95% efficiency. This prototype system weighed less than 50% of similar high-power wireless charging system while simultaneously exhibiting better safety characteristics. Due to better material utilization, the reduction in mass is expected to translate into similar cost reduction for the magnetic coupler. Additionally, the smaller footprint of the system can ease vehicle integration difficulties that would be encountered using other technology. Furthermore, the three-phase design can be made to operate with existing single-phase coupler design more easily and without intentional physical misalignment which would otherwise pose safety issues.This project developed ORNL’s WPT technology to satisfy the specifications and requirements for electric vehicle (EV) charging. The result of the project will be a prototype and reference design for a high-power wireless charging system—including magnetics, power electronics, and controls—serving as a baseline for product development.

Smart Charging of Electric Vehicle

This project proposes improving the technology level of the three-phase wireless charging technology developed at Oak Ridge National Laboratory (ORNL). Successful commercialization of wireless charging systems require that they meet strict safety standards for electromagnetic field emissions and interoperability with other wireless charging technology. ORNL has previously demonstrated a 50kW three-phase wireless power transfer system with 95% efficiency. This prototype system weighed less than 50% of similar high-power wireless charging system while simultaneously exhibiting better safety characteristics. Due to better material utilization, the reduction in mass is expected to translate into similar cost reduction for the magnetic coupler. Additionally, the smaller footprint of the system can ease vehicle integration difficulties that would be encountered using other technology. Furthermore, the three-phase design can be made to operate with existing single-phase coupler design more easily and without intentional physical misalignment which would otherwise pose safety issues. This project developed ORNL’s WPT technology to satisfy the specifications and requirements for electric vehicle (EV) charging. The result of the project will be a prototype and reference design for a high-power wireless charging system—including magnetics, power electronics, and controls—serving as a baseline for product development.

This paper presents a performance analysis of the power inverter and switching devices for wireless charging systems (WCS) applied in Electric Vehicles (EV). The purpose of this analysis was to determinate the switching devices impact and effects on the WCS efficiency under EV chargers conditions. Besides, to show a perspective on the trend and use of new power semiconductor technologies and the way for choosing the adequate devices. The study was developed through the power and total losses evaluation on the devices, considering the EV chargers requirements such as power levels and operation frequency. The analysis showed that not only the power transmission stage is so important in the WCS design for achieving high-performance chargers but else the electronic components of the power inverter. In addition, the investigation showed that the use of new technologies is necessary for the new WCS requirements, as well as additional considerations in the design of WCS with the proposed standards.

Wireless charging structure and efficiency analysis based on wind–solar hybrid power supply system

The growing need for sustainable transportation options has led to significant interest in wireless solar electric vehicle (EV) charging systems, which merge renewable energy with user-friendly charging infrastructure. This study introduces an innovative wireless charging system that leverages solar energy to power EVs efficiently, removing the necessity for physical connectors and improving user convenience. The proposed system integrates photovoltaic panels, a highly efficient power conversion unit, and resonant inductive coupling technology to facilitate seamless energy transfer from solar sources to the vehicle’s battery. The approach includes designing and simulating the various system components, such as the solar energy harvesting module, power management circuitry, and wireless power transfer coils, followed by experimental validation under different environmental and load conditions. Key findings indicate that the system achieves an overall efficiency of 85% under optimal solar irradiation, with a wireless power transfer efficiency of 92% at a separation distance of 15 cm between coils. Furthermore, the system demonstrates robust performance in diverse weather conditions, maintaining stable power delivery through integrated energy storage and smart power management algorithms. Major conclusions emphasize the viability of the wireless solar EV charging system as a sustainable and scalable solution for both urban and remote settings, reducing dependency on grid electricity and lowering carbon emission. The study highlights the potential of integrating solar energy with wireless charging technology to promote the adoption of clean transportation, providing a reliable and eco-friendly alternative to traditional charging practices.

This paper presents a maximum efficiency tracking control scheme for a closed-loop wireless power charging (WPC) system for wireless charging of mobile devices. Generally, wireless charging systems need a precise output voltage and current with the highest possible efficiency. In an open-loop system, output voltage and efficiency depend strongly on the coupling coefficient and load condition. Alternatively, a closed-loop WPC system has a constant output voltage against coupling and load variations. Many studies have been carried out regarding closed-loop systems. However, those previous studies have the drawback of efficiency degradation. In this paper, we propose a maximum efficiency tracking control scheme to achieve the highest possible efficiency. Therefore, the proposed WPC system satisfies both the requirements of a constant output voltage and high efficiency. The proposed control scheme determines the current of the transmitter based on the data received by the receiver via Bluetooth. For validation, the proposed WPC system was implemented at 6.78 MHz using loosely coupled series–series resonant coils, and we verified that the proposed system can track the maximum efficiency while maintaining a constant output voltage.

The wireless electric vehicle (EV) charging system is highly safe and flexible. To reduce the weight and cost of EVs, the wireless charging system, which simplifies the structure inside an EV and utilizes the transmitter-side control method, has become popular. This study investigates the transmitter-side control methods in a wireless EV charging system. First, a universal wireless charging system is introduced, and the function of its transfer power is derived. It is observed that the transfer power can be controlled by regulating either the phase-shift angle or the DC-link voltage. Further, the influence of the control variables is studied using numerical analysis. Additionally, the corresponding control methods, namely the phase-shift angle and the DC-link voltage control, are compared by calculation and simulation. It is found that: (1) the system efficiency is low with the phase-shift control method because of the converter switching loss; (2) the dynamic response is slow with the DC-link voltage control method because of the large inertia of the inductor and capacitor; (3) both the control methods have limitations in their adjustable power range. Therefore, a combined control method is proposed, with the advantages of high system efficiency, fast dynamic response, and wide adjustable power range. Finally, experiments are performed to verify the validity of the theoretical analysis and the effectiveness of the proposed method. This study provides a detailed and comprehensive analysis of the transmitter-side control methods in the wireless charging system, considering the sensitivity of parameters, converter losses, system efficiency, and dynamic performance, with the dead-time effect taken into consideration. Moreover, the proposed control method can be used to realize the optimal combination of the phase-shift angle and the DC-link voltage with good dynamic performance, and it is useful for the optimal operation of the wireless charging system.

Energy harvesting is a process that harvests ambient energy from surrounding to useful electrical energy such as from light, thermal, wind, kinetic, radio-frequency, and biochemical. The wireless energy harvesting and charging system allow electronic devices to operate without a conventional power source by eliminating the physical connection to the wearable device. This paper describes the evaluation of the wireless charging system by using the energy harvesting method to be used in the wearable device for the visually impaired person. This paper presents a comparison between the best energy harvester such as the photovoltaic, photodiode, and radio-frequency. The piezoelectric, wind, and biochemical methods were not done because it was not appropriate to be used in the wearable device for the visually impaired person. The experiments for comparing the best configuration for the energy harvesting method and evaluation of energy harvesting performance by various configurations such as single, series, and parallel connection are conducted. This wireless charging system by using a wireless docking system desired to eliminate the usage of the bulky battery that has been installed in the wearable device to reduce weight and easy to charge especially for the visually impaired person. Consequently, the wireless charging system by using the energy harvesting method could give the comfortability and increase the quality of life of the visually impaired person.KeywordsEnergy harvestingWireless chargingWearable deviceTravel aidVisually impaired personAssistive technologySmart system

In this work, it is proposed to develop wireless charging systems for sustainable electric vehicles. Wireless charging can transfer power from an outlet to devices without a connecting wire. Wireless electric vehicle charging is of two types; they are static wireless charging and dynamic wireless charging. The main advantages of wireless charging are that it takes less time, is more efficient, and less maintenance, and is more durable. However, the wireless charging system also has some problems, like the vehicle must be parked close to the charging pad, the installation cost, and a large battery required. Static wireless charging involves the charging of a sustainable electric vehicle while it is in a stationary position. While dynamic charging involves charging an electric vehicle in motion, charging pads are installed on the roads. In this work, the simulation model has been developed for the PS topology of wireless charging using JMAG software. This can further be developed in a prototype for EVs' static wireless charging system.