Wireless Charging Research Articles

A Self-Balanced Multi-Channel Wireless Charging System for EV

A Self-Balanced Multi-Channel Wireless Charging System for EV

Dynamic parameter identification method for wireless charging system of AUV based on multi-strategy nonlinear rime algorithm

The magnetic coupling wireless charging system may experience changes in mutual inductance and load due to the impact of actual underwater environment, which would lower the system’s transmission efficiency. In response to the circumstance, firstly, this paper proposes the circuit structure of the dynamic autonomous underwater vehicle wireless charging system with LCC-S-Buck-Boost, and a dynamic parameter identification method based on the multi-strategy nonlinear Rime algorithm. Secondly, it is proposed that the difference between the actual input current value of the primary side of the system and the current value calculated by the identification method, and the difference between the actual coil current value of the secondary side of the system and the coil current value calculated by the identification method are used as the adaptability function of the identification method, and the construction of the actual model of the system and the identification algorithm has been completed, and the results of the identification of the system’s mutual inductance and the equivalent load have been obtained. Finally, based on the identification results, it is confirmed that the proposed identification method is efficient and accurate in identifying system mutual inductance and equivalent loads in complex underwater environments by comparing with other algorithms under different values of mutual inductance and equivalent loads.

An integrated hybrid dual-frequency wireless charging system with anti-offset performance via phase-shift control for consumer electronics

Abstract Wireless charging systems for consumer electronics suffer from the offset issue, which leads to drastic changes in the mutual inductance and thus produces unstable outputs. To solve the issue, this paper proposes an integrated hybrid dual-frequency wireless charging system with an anti-offset performance. The proposed topology can be equivalent to the CLC-S and S-S topologies at fundamental and third harmonic frequencies, respectively. Combining the opposite trends of the output voltages in the CLC-S and S-S topologies, the anti-offset performance can be realized. To further enhance the anti-offset performance, the phase-shift control is adopted to adjust the ratio of fundamental and third harmonic, thus extending the anti-offset range. The mathematical and experimental models are established. The experimental results are well aligned with the calculated ones, confirming that the proposed system can maintain stable output and high efficiency under different offsets.

Evaluation of practicality of wireless charging for electric vehicles in the next 10 years

As the electric vehicle market is expanding rapidly due to the need for sustainable development; a solution is needed to deal with current problems related to electric vehicles, this includes relatively limited driving range, relatively lack of charging spots during busy season, and the inconveniences of plug-in charging, such as dealing with cables. Therefore, wireless charging technology capable of charging electric vehicles while they are in motion becomes a potential solution. Assessing whether this technology will be mass-applied in the future is crucial. Given the limited current research that evaluates the practicality of wireless charging technology for electric vehicles with a time scale, this article aims to assess the aspects of safety, cost, efficiency, materials, user acceptance and other factors to determine the likelihood of making wireless charging practical for electric vehicles in the next decade. Furthermore, by distributing questionnaires to electric and gasoline car owners to gather participants’ opinions and expectations on wireless charging for electric vehicles, statistical analysis of the questionnaire results; interview with a professor at Shanghai University who is an expert in magnets and electricity, conducting secondary research, this article concludes whether wireless charging technology for electric vehicles can be implemented in the decade or not. As an impact, this article includes a time scale by conducting an evaluation instead of implicitly mentioning the time scale.

Dual‐state and self‐oscillating wireless charging system topology for direct‐drive battery

AbstractThis study proposes a novel topology with bi‐stable controlling for wireless charging system (WCS). The advantage of the proposal is that a desired charging current can be directly output from rectifier without requiring charging current manager, thereby greatly simplifying the structure of the receiver. The proposed topology not only improves the transmission efficiency of system, but also reduces the loss and heat dissipation in the receiver. The principle of the topology is outlined and the circuitry model and control strategy are established and analyzed in detail. The innovation of this method lies in treating the coupler as a current transformer, which enables more direct and simpler controlling of the charging current. The experiment is conducted to verify that when the peak charging current is increased from 5A to 10A, the system efficiency is increased up to 82.0% and the receiver efficiency up to 96.7%. Both computational simulation and experimental validation have confirmed the feasibility of the proposed method. Compared with conventional WCS topology with compensation, the proposed method improves the system efficiency by 3% and the receiver efficiency by 5%, which is more suitable for practical applications where compact and light‐weight receiver is required.

Green Energy Solutions for EV Charging: A Comprehensive Review of Solar-Powered Stations

Solar power EV charging stations is a great move in the right direction of sustainability in transport and energy sources. In this review, integration of renewable sources of energy, for instance solar photovoltaics (PV) into electric vehicle (EV) infrastructure will be reviewed including challenges and opportunities with regard to implementation. It assesses the key components, such as solar PV panels, inverters, energy storage systems, and energy management systems, for their roles in optimizing system efficiency, reliability, and scalability. While technical challenges persist in the form of intermittent energy sources, grid instability, and lack of standardization, advances in energy storage, AI-driven energy management, and modular designs offer significant opportunities. Economic barriers include high costs of initial investments, which the long-term saving, incentives, and innovative designs offset as they reduce the risks of investing. Strategies for policy driven are critical in standardization of EV infrastructure and promotion of renewable energy. In conclusion, innovations such as integration of V2G, wireless charging, and the decentralized energy models are seen as future approaches to optimal utilization of renewable energy in EV charging. Solar-powered EV charging stations, despite the existing barriers, hold transformative potential for reducing carbon emissions and enhancing energy security, paving the way for a greener transportation ecosystem.

Collaborative Optimization Framework for Coupled Power and Transportation Energy Systems Incorporating Integrated Demand Responses and Electric Vehicle Battery State-of-Charge

The growing adoption of electric vehicles (EVs) and advancements in dynamic wireless charging (DWC) technology have strengthened the interdependence between power distribution networks (PDNs) and electrified transportation networks (ETNs), leading to the emergence of coupled power and transportation energy systems (CPTESs). This development introduces new challenges, particularly as DWC technology shifts EV charging demand from residential plug-in charging to charging-while-driving during commuting hours, causing simultaneous congestion in both ETNs and PDNs during peak times. The present work addresses this issue by developing a collaborative optimization framework for CPTESs that incorporates integrated demand responses (IDRs) and EVs battery state-of-charge (SOC). In the ETN, a multiperiod traffic assignment model with time-shiftable traffic demands (MTA-TSTD) is established to optimize travelers’ routes and departure times while capturing traffic flow distribution. Meanwhile, effective path generation models with EVs battery SOC are proposed to optimize charging energy during driving and construct the effective path sets for MTA-TSTD. In the PDN, a multiperiod optimal power flow model with time-shiftable power demands (MOPF-TSPD) is formulated to schedule local generators and flexible power demands while calculating the power flow distribution. To enhance temporal and spatial coordination in CPTESs, a distributed coordinated operation model considering IDRs is proposed, aiming to optimize energy consumption, alleviate congestion, and ensure system safety. Finally, an adaptive effective path generation algorithm and an ETN–PDN interaction algorithm are devised to efficiently solve these models. Numerical results on two test systems validate the effectiveness of the proposed models and algorithms.

An Energy-Adjustable, Deformable, and Packable Wireless Charging Fiber Supercapacitor.

Wireless charging energy storage devices eliminate bulky wires of wearable electronics. However, rigid shape and specific charging energy restrict their applications in space-limited portable electronics. Herein, an all-carbon fiber supercapacitor is presented that features shape-adjustable, packable, and energy-controllable wireless charging functions. With the unique on-dimensional circuit structure, the maximum energy transfer efficiency from the electrical energy received by the wireless charging unit to the output energy of the fiber supercapacitor can reach up to ≈60.8%, and meanwhile this integrated fiber device exhibits an outstanding area capacity of 803 mF cm-2 and energy density of 1004 µWh cm-2, superior to most of the fiber supercapacitors. Moreover, this unique device can endure significant deformation in shape of circles ranging from 2 to 20cm diameter, and can be packed into narrow spaces, such as smart bracelet and disk-shaped pet global positioning system (GPS). By altering the device shape, the wireless charging current, voltage, and power can be adjusted in the range of 0.5-20mA, 1.4-15.5V, and 0.003-313mW, accommodating the energy requirements for nearly all existing micro-electronics. This work offers unprecedented opportunities for packable, space-confined and energy harvesting controllable wearable electronics.

A New Magnetic Coupler with High Misalignment Tolerance and Inherent Constant Current–Constant Voltage for Underground Wireless Charging

In an underground inductive power transfer (IPT), it is inevitable to produce the phenomenon of misalignment between the transmitter and the receiver, which will reduce the output current, voltage and output efficiency of the whole IPT system. Aiming to solve this problem, a universal hybrid coupler is proposed, which can still stabilize the output in the expected range and has the ability of anti-misalignment when the X and Z directions are misaligned. The coupler is composed of a BP coupler and Γ type network. The secondary edge of the coupler introduces a Γ network, which decouples the two main coils on the same side of the receiver from the auxiliary coil and reduces the complexity of the system. The coupler can effectively reduce the coupling fluctuation caused by physical movement between the downhole transmitting end and the receiving end, thereby ensuring the stable output of the coupler. As a widely used IPT system, it can access the rest of the circuit topology whose output is independent of the load and achieve misalignment-tolerant output. Finally, based on the proposed hybrid IPT coupler theory, a 500 W misalignment-tolerant coupler prototype was built, and the compensation topologies were configured as series–series (SS) and series/inductance/capacitance/capacitor (S/LCC) structures. When the X and Z direction is misaligned, the constant current and voltage independent of the load can be output by switching the compensation topology. The experimental results are the same as the theoretical analysis.

A Decoupled Modulation Strategy for Constant Voltage/Current Wireless Charging System Under High Coils Misalignment

ABSTRACTOutput fluctuation and lower transmission efficiency under load and mutual inductance variation are hot concerned in the wireless charging system for power batteries. In this paper, a decoupled tracking strategy is proposed to realize constant voltage (CV) or current (CC) output and high transmission efficiency. The circuit model of series–series compensation network is built, and corresponding transmission characteristics can be derived. First, the load and mutual inductance value can be estimated by measuring the primary electrical information, including the inverter output voltage, current, and the phase error between them. Then load‐independent voltage or current output characteristics under coils misalignment can be maintained by tracking the optimal switching frequency of inverter part. In addition, the value of output voltage or current can be adjusted flexibly for different operation occasions by the employment of pulse‐width modulation. As a result, the load‐independent output characteristics realization and output adjustment can be decoupled. Based on only the primary measuring information, the CV/CC output can be maintained via the proposed hybrid control strategy when the coils misalignment and load variation happen, increasing the robustness of whole wireless power transfer (WPT) system. Furthermore, the soft switching of all power switches in the inverter part can be realized to reduce the switching loss. Compared with previous research, the proposed wireless charging system has a higher power density and a simplified control strategy. Finally, an experimental platform with 60‐V charging voltage and 3.6‐A charging current is built to verify the feasibility of the proposed sys‐tem and control method.

Adaptive output feedback control of a bidirectional AC/DC totem‐pole PFC converter for wireless charging of electric vehicles

AbstractThis paper deals with the control problem of a single‐phase bidirectional alternating current/direct current (AC/DC) totem‐pole power factor correction (PFC) converter intended to be used in wireless power transfer (WPT) chargers for electric vehicles (EVs). The converter is operating as a bridgeless boost rectifier with the PFC functionality during grid to vehicle (G2V) mode and as a PFC inverter during vehicle to grid (V2G) mode. Firstly, the operating principle is presented. Secondly, an overall mathematical model governing all the operating modes of the converter is elaborated. Thirdly, due to the nonlinearity of the studied system, a nonlinear controller–based Lyapunov technique is designed to achieve the following control objectives: (i) unity power factor (UPF) during both power transfer modes G2V and V2G, (ii) regulation of the DC‐link voltage, and (iii) asymptotic stability of the closed‐loop system. Further, as the developed control law requires the measurement of all voltages and currents, an adaptive observer–based Kalman‐like technique is designed to estimate all the required signals and parameters. The performances of the proposed output feedback control technique are validated through several simulation scenarios showing that all control objectives are achieved. It should be noted that the use of the Kalman observer reduces the complexity of the systems as it requires only two measurements (grid voltage and current) making it an advantageous solution over existing solutions where three measurements are generally used. Furthermore, due to the low‐pass filtering behavior of the observer and its susceptibility to estimate the converter's parameters, the robustness of the controller and its insensitivity to the parameter uncertainties are greatly improved.

Dynamic Wireless Charging of Electric Vehicles Using PV Units in Highways

Transitioning from petrol or gas vehicles to electric vehicles (EVs) poses significant challenges in reducing emissions, lowering operational costs, and improving energy storage. Wireless charging EVs offer promising solutions to wired charging limitations such as restricted travel range and lengthy charging times. This paper presents a comprehensive approach to address the challenges of wireless power transfer (WPT) for EVs by optimizing coupling frequency and coil design to enhance efficiency while minimizing electromagnetic interference (EMI) and heat generation. A novel coil design and adaptive hardware are proposed to improve power transfer efficiency (PTE) by defining the optimal magnetic resonant coupling WPT and mitigating coil misalignment, which is considered a significant barrier to the widespread adoption of WPT for EVs. A new methodology for designing and arranging roadside lanes and facilities for dynamic wireless charging (DWC) of EVs is introduced. This includes the optimization of transmitter coils (TCs), receiving coils (RCs), compensation circuits, and high-frequency inverters/converters using the partial differential equation toolbox (pdetool). The integration of wireless charging systems with smart grid technology is explored to enhance energy distribution and reduce peak load issues. The paper proposes a DWC system with multiple segmented transmitters integrated with adaptive renewable photovoltaic (PV) units and a battery system using the utility main grid as a backup. The design process includes the determination of the required PV array capacity, station battery sizing, and inverters/converters to ensure maximum power point tracking (MPPT). To validate the proposed system, it was tested in two scenarios: charging a single EV at different speeds and simultaneously charging two EVs over a 1 km stretch with a 50 kW system, achieving a total range of 500 km. Experimental validation was performed through real-time simulation and hardware tests using an OPAL-RT platform, demonstrating a power transfer efficiency of 90.7%, thus confirming the scalability and feasibility of the system for future EV infrastructure.

Trimodal Watch-Type Wearable Health Monitoring Device

In the domain of healthcare, wearable health monitoring devices have emerged as essential tools for the advancement of patient health tracking. These devices facilitate the provision of real-time medical data to clinicians, enabling early diagnosis, timely intervention, and enhanced management of individual health. This study introduces an innovative trimodal wearable health monitoring device in the form of a wristwatch. The device integrates a breath analyzer for the assessment of gaseous phase biomarkers, a sweat analyzer for the evaluation of aqueous-phase biomarkers, and an infrared sensor for the measurement of body temperature in the optical phase. Engineered on a compact 3 cm × 3 cm printed circuit board, the device has been optimized for wearability, power efficiency, and seamless integration with both wired and wireless charging and communication systems. Furthermore, custom software applications, designed for both Windows and Android platforms, have been developed to facilitate intuitive data visualization and storage on personal computers and smartphones. Empirical results from real-time chemical testing substantiate the device’s efficacy and potential as an advanced solution for wearable health monitoring.

An Efficiency Examination of the DJI Mavic 2 Pro’s Precision Landings

This paper reports on the results of multicast latency and round trip time measurements for a particular deployment of nodes In recent times, the application areas of unmanned aerial vehicles (UAVs) are expanding, and autonomous functions are becoming increasingly prominent, eliminating the need for remote pilot control. Certain applications require the drone to use a docking station autonomously, even for wireless charging. This involves performing autonomous takeoff and landing, where high precision is demanded. These maneuvers can be significantly influenced by environmental factors. The effectiveness of the precision landing function of the DJI Mavic 2 Pro UAV in strong winds is investigated in this article based on experimental measurements conducted outdoors. New findings on the precision landing capabilities of the DJI Mavic 2 Pro UAV are presented in this paper, particularly under windy conditions. The efficiency of precision landing is compared in cases when the precision landing function is enabled versus when it is disabled. It is investigated whether there is a statistically significant difference between the two landing modes in strong winds and it is examined whether the DJI Mavic 2 Pro can perform precision landing on a surface of a specific size in windy conditions. This helps to predict the suitability of the DJI Mavic 2 Pro for precise landing and wireless charging at a docking station in strong winds and high gusts.

Summary of Wireless Charging Technology for Electric Vehicles

The rapid popularity of electric vehicles has promoted the rapid development of wireless charging technology. This paper reviews the current research progress and application status of wireless charging technology for electric vehicles. Inductive coupling, magnetic resonance coupling and non-directional radiofrequency radiation, three main wireless power transmission methods, including their principles and advantages, are introduced. In addition, the practical application of the technique, such as near field application and far field application, is also discussed. Finally, the development direction of wireless charging technology for electric vehicles in the future is looked forward, including the key technical paths of optimizing system design, improving energy transmission efficiency and reducing system cost. In summary, this paper aims to provide comprehensive theoretical support and practical guidance for the research and practice of wireless charging technology for electric vehicles.

The realization of power stabilization and reactive power minimization for wireless charging system under high coils misalignment

The realization of power stabilization and reactive power minimization for wireless charging system under high coils misalignment

Planar Double-Winding Foreign Object Detection for the EV Wireless Charging System Based on Time-Division Multiplexing

Planar Double-Winding Foreign Object Detection for the EV Wireless Charging System Based on Time-Division Multiplexing

Enhancing electromagnetic properties of NiCuZn ferrites through Nb and Li Co-doping for wireless power transfer

With the rapid development of wireless charging technology, there is a growing demand for ferrite materials with high permeability, high saturation magnetic induction intensity, and low power loss. This study aims to enhance the electromagnetic performance of NiCuZn ferrite by co-doping Nb5+ and Li+. The influence of the doping levels Nb5+ and Li + on the morphology, crystal structure, and electromagnetic properties of NiCuZn ferrite were studied in detail. Structural analysis shows that the lattice constant decreases as the Nb5+-Li+ doping concentration increases, and the NiCuZn ferrite exhibits a high density and homogeneous microscopic morphology at the optimum concentration of x = 0.004. Specifically, at a doping concentration of x = 0.004, the magnetic permeability at 1 MHz measured at 1112.1, the saturation magnetic induction intensity reached 458.98 mT, and the power loss was minimized to 521.85 kW/m3, demonstrating significant improvement in the transmission power of wireless charging applications.

Green Laser-Powered UAV Far-Field Wireless Charging and Data Backhauling for a Large-Scale Sensor Network

Green Laser-Powered UAV Far-Field Wireless Charging and Data Backhauling for a Large-Scale Sensor Network

Enhanced Axial Misalignment Tolerance in a 10-kW Autonomous Underwater Vehicle Wireless Charging System Utilizing a Split Solenoid Coupler

Enhanced Axial Misalignment Tolerance in a 10-kW Autonomous Underwater Vehicle Wireless Charging System Utilizing a Split Solenoid Coupler