Wireless Charging Research Articles

Self-healing Micro-Supercapacitor Based on Robust Liquid Metal-CNT-PEDOT:PSS Film for Wireless Powering of Integrated Strain Sensor.

The limited energy density of micro-supercapacitors (MSCs) and challenges in their integration significantly impede the advancement of MSCs in wearable electronic devices. Here, this work designs a robust and wrinkled liquid metal-CNT-PEDOT:PSS film with high capacity and self-healing properties (defined as LM-CNT-PEDOT:PSS). The wrinkled structure further enhances tensile properties of LM-CNT-PEDOT:PSS and increases its active specific surface area per unit. Simultaneously, the incorporation of liquid metal (LM) enhances both the mechanical and healing properties of the LM-CNT-PEDOT:PSS electrode. The flexible and self-healing MSC based on wrinkled LM-CNT-PEDOT:PSS shows a remarkable specific capacitance of 114.29 mF cm-2 and a high areal energy density of 15.47 µW h cm-2. Furthermore, the electrochemical performance of the healed MSC retained 90.01% of its initial performance, and the MSC unit can be arbitrarily integrated according to various energy and voltage requirements through the healing properties of LM-CNT-PEDOT:PSS, widening the range of applications in next-generation microelectronic devices. The wrinkled LM-CNT-PEDOT:PSS film is utilized for the fabrication of a highly sensitive strain sensor. Simultaneously, the prepared sensor can be seamlessly integrated with wireless charging and MSC to facilitate convenient monitoring of physiological signals, thereby offering an effective solution for the advancement of wearable technology and self-powered systems.

Improving efficiency of wireless charging system in electric vehicle using a hybrid ultracapacitor-battery energy storage approach

This research aims to enhance the efficiency of wireless charging systems in electric vehicles by integrating a hybrid ultracapacitor-battery energy storage solution. Traditional standalone battery-based energy storage systems in wireless charging often face sub-optimal charging efficiency, resulting in extended charging times and reduced energy transfer efficiency. To address this limitation, we propose a hybrid approach that combines the rapid charging capability of ultracapacitor (supercapacitor) with the long-term storage capacity of batteries. The optimal charging range is 0 cm to 2 cm, and the combined output voltage and current are 5 V to 12 V and 0.63 A, respectively. This hybrid energy storage system will significantly boost electric vehicles (EVs) charging efficiency. Our research involves experimental evaluation and data analysis to assess crucial parameters, including charging efficiency, energy transfer efficiency, and charging time. The experimental results are validated and compared against existing battery-only systems, shedding light on the advantages and limitations of the hybrid approach. This study contributes to the optimization of wireless charging systems, enhancing energy transfer efficiency, and promoting the broader adoption of wireless charging technology in electric vehicles.

Energy-Efficient Trajectory Optimization With Wireless Charging in UAV-Assisted MEC Based on Multi-Objective Reinforcement Learning

Energy-Efficient Trajectory Optimization With Wireless Charging in UAV-Assisted MEC Based on Multi-Objective Reinforcement Learning

Enhancing core loss and thermal performance for wireless EV charging with a cross-laminated core structure

This paper explores the implementation of laminated cores in inductive power transfer (IPT) systems for wireless EV charging. Two conventional structures are initially evaluated: the horizontally laminated core (H-cores) and the vertically laminated cores (V-cores). Fe-based nanocrystalline materials are applied for these structures due to their excellent core loss properties. The study introduces material modelling and loss analysis methods that combine toroidal measurements with eddy current losses from norm flux. Finite Element Method (FEM) simulations reveal that both structures experience significant flux density and thermal imbalances, creating operational challenges for IPT systems. To address these issues, a cross-laminated structure is proposed, combining the benefits of both horizontal and vertical laminations to reduce thermal imbalances. Simulation results show improved system performance, confirmed by experimental tests. Using the cross-lamination approach, the operational duration of IPT systems can be extended, and the maximum equilibrium temperature at an output current of 10 A is reduced by over 40°C, from 90.4 °C to 47.2 °C. Additionally, efficiency improves by over 0.4 % at 11.1 kW output power. This innovative core design provides a practical solution for implementing laminated cores in high-power wireless EV charging applications, enhancing efficiency and thermal performance.

Reliability Estimation of Wired and Wireless Fast Electric Vehicle Charging Systems

Reliability Estimation of Wired and Wireless Fast Electric Vehicle Charging Systems

A Misalignment-Insensitive Hybrid Reconfigurable Wireless Charging System for Constant-Voltage and Constant-Current Outputs Based on a Novel Bipolar Coil Symmetrical to Two Perpendicular Directions

A Misalignment-Insensitive Hybrid Reconfigurable Wireless Charging System for Constant-Voltage and Constant-Current Outputs Based on a Novel Bipolar Coil Symmetrical to Two Perpendicular Directions

High-entropy alloys as magnetic shielding materials in low-frequency wireless power transmission

Soft magnetic materials are required to exhibit high saturation magnetization and low coercivity. Iron-based metal alloys, such as FeMnZn, are commonly used commercial soft magnetic materials with electromagnetic shielding functions. However, these alloys generally exhibit low saturation magnetization, poor high-temperature stability, and significant magnetic losses. In recent years, many research groups have highlighted the excellent soft magnetic properties of high-entropy alloys (HEAs). This study develops new HEA powders with superior soft magnetic characteristics for applications in low-frequency magnetic shielding components. The research found that the FeCoNiSiCuNb HEA, under appropriate ball-milling and annealing conditions, exhibits high saturation magnetization and excellent high-temperature properties, retaining over 50% of its magnetism even at 700K. At an operating frequency of 100 kHz, compared to FeMnZn, the real permeability of the FeCoNiSiCuNb HEA is increased by 2.25 times. Preparing this HEA material as a magnetic shielding material can lead to higher inductance, a coupling coefficient increased to 0.84, and a transmission efficiency improvement of 19%, demonstrating the potential of high-entropy alloys in wireless charging applications.

A Wide-Range Global Optimal Control Strategy for Wireless Charging Systems in Electric Vehicles

A Wide-Range Global Optimal Control Strategy for Wireless Charging Systems in Electric Vehicles

Novel Designs of Magnetic Coupled Structure With 360° Rotation Misalignment Tolerance for AUVs’ Wireless Charging System

Novel Designs of Magnetic Coupled Structure With 360° Rotation Misalignment Tolerance for AUVs’ Wireless Charging System

An Overview of Key Technologies for Wireless Charging Systems for Unmanned Aerial Vehicles

With the demand for an intelligent and modernized society, the application of UAVs has become increasingly widespread. However, their performance is limited by battery capacity constraints, making UAV wireless charging an effective solution for prolonging operational time. This thesis focuses on the research of shutdown technology in UAV wireless charging systems. Firstly, it introduces the current research status in this field. It then comprehensively covers the principles of wireless energy transmission, with a particular focus on magnetic coupling resonance. Next, it addresses key issues such as compensation topology mechanisms and coupling coil circuit analysis. Following that, a technical analysis is conducted based on hover charging and landing charging, respectively. Finally, the thesis summarizes the current progress of UAV wireless charging and provides an outlook on areas for improvement in related research.

Lightweight Research on Wireless Charging System for Unmanned Aerial Vehicles Based on High Efficiency

Abstract: Unmanned aerial vehicles (UAVs) are characterized by safety, flexibility, and economy, and are widely used in many fields. At present, due to the limitation of UAV loads and the bottleneck of battery technology, UAVs can't carry out missions for a long time. The wireless charging system for UAVs has the advantages of safety, flexibility, automation, and environmental adaptability, so it has gained wide attention. Electromagnetic induction wireless energy transmission system is a system that transmits electrical energy through a magnetic field, and in electromagnetic induction wireless energy transmission system, it is necessary to reach the goals of lightweight, high efficiency, anti-skewing, and modularization. In order to achieve the goals of high efficiency and anti-deviation, this paper adopts three sets of series-connected rounded rectangular coils as the transmitting stage to improve the charging efficiency and anti-deviation ability; in order to achieve the goal of lightweight, this paper reduces the weight by changing the material of the magnetic core, and using the annulus core amorphous alloy core; in order to achieve the goal of modularity, this paper designs to carry multiple sets of receiving coils, which can be switched on and off according to the demand in order to satisfy the different power requirements. Finally, a bilateral LCC compensation topology network is established to control the input and output currents to achieve the design goal. The method proposed in this paper helps to realize the automatic charging of UAV and improve the endurance of UAV, so as to enhance the working hours and inspection range of UAV, and make UAV capable of doing more work.

A Three‐Phase Omnidirectional Wireless Charger Based on Segmented Arc‐Shaped Coupler With High Anti‐Rotation Offset Feature for AUVs

ABSTRACTWhen the autonomous underwater vehicle (AUV) is charged by wireless charging technology (WCT), the coupler will be misalignment due to the impact of marine environment factors, which can lead to the weak stability of the system output. Besides, the electromagnetic field generated by the coaxial coil is concentrated in the center of the AUV hull, and the strong electromagnetic field may interfere with the normal operation of the power electronic equipment inside the AUVs. To address the above problems, this paper proposes a novel coupler with high anti‐offset and suppression of the central magnetic field of the AUVs. The coupler is composed of a three‐phase segmented arc‐shaped transmitter coils and a cylindrical receiver coil. The coupler can implement the suppression of the AUV central magnetic field and the promotion of anti‐rotation offset feature under the omnidirectional uniform magnetic field control method. To better adapt the proposed coupler and meet the battery charging requirements, a three‐phase wireless charging topology with a relay is designed, which can acquire the smooth transition between the two charging modes without constructing the wireless communication between two sides and detecting the state of charge (SOC). Finally, to verify the feasibility of the proposed scheme, a 1‐kW AUV wireless charging prototype is built. The experimental results indicate that the maximum output power fluctuation rate of the system is 1.1% in the case of the full‐angle rotation offset.

Intelligent Wireless Charging Path Optimization for Critical Nodes in Internet of Things-Integrated Renewable Sensor Networks.

Wireless sensor networks (WSNs) play a crucial role in the Internet of Things (IoT) for ubiquitous data acquisition and tracking. However, the limited battery life of sensor nodes poses significant challenges to the long-term scalability and sustainability of these networks. Wireless power transfer technology offers a promising solution by enabling the recharging of energy-depleted nodes through a wireless portable charging device (WPCD). While this approach can extend node lifespan, it also introduces the challenge of bottleneck nodes-nodes whose remaining energy falls below a critical value of the threshold. The paper addresses this issue by formulating an optimization problem that aims to identify the optimal traveling path for the WPCD based on ant colony optimization (WPCD-ACO), with a focus on minimizing energy consumption and enhancing network stability. To achieve it, we propose an objective function by incorporating a time-varying z phase that is managed through linear programming to efficiently address the bottleneck nodes. Additionally, a gateway node continually updates the remaining energy levels of all nodes and relays this information to the IoT cloud. Our findings indicate that the outage-optimal distance achieved by WPCD-ACO is 6092 m, compared to 7225 m for the shortest path and 6142 m for Dijkstra's algorithm. Furthermore, the WPCD-ACO minimizes energy consumption to 1.543 KJ, significantly outperforming other methods: single-hop at 4.8643 KJ, GR-Protocol at 3.165 KJ, grid clustering at 2.4839 KJ, and C-SARSA at 2.5869 KJ, respectively. Monte Carlo simulations validate that WPCD-ACO is outshining the existing methods in terms of the network lifetime, stability, survival rate of sensor nodes, and energy consumption.

Anisotropic Heat Transfer in a Fibrous Membrane with Hierarchically Assembled 2D Materials.

Effective heat redistribution in specific directions is vital for advanced thermal management, significantly enhancing device performance by optimizing spatial heat configurations. We have designed and fabricated a hierarchical fibrous membrane that enables precise heat directing. By integrating hierarchical structure design with the anisotropic thermal conductivity of two-dimensional (2D) materials, we developed a fibrous membrane for anisotropic heat transfer. Such a structure is fabricated by aligning a 1D structured fiber in the 2D plane to achieve anisotropy at each scale level. The fiber units, where 2D nanosheets circumferentially and axially aligned, achieved a high axial thermal conductivity of 16.8 W·m-1·K-1 and advanced heat directing ability, confirmed by characterizations and simulations. The assembled membrane demonstrated an exceptional tensile strength (365 MPa) and high thermal conductivity (10.5 W·m-1·K-1) along the fiber axis. Our membranes are seen as a refined model for thermal management materials, combining the benefits of heat spreaders and thermal interface materials, thus being proficient in directing heat along programmed pathways. A practical wireless charging cooling demonstration illustrated this. Our methodology also proved versatile with different 2D fillers and various geometries. This research presents a method to achieve precise heat directing at the material's level, facilitating the systematic design of thermal management in electronics.

Renewable energy driven on-road wireless charging infrastructure for electric vehicles in smart cities: A prototype design and analysis

The adoption of electrical vehicles (EVs) has increased due to the increasing concerns about fossil fuel shortages, rising costs, and environmental impacts. This increasing adoption of EVs significantly increase power demand on utility grids. Moreover the EVs require more time for charging compared to fossil fuel vehicles. To address these challenges, this study proposes a renewable energy-based on-road wireless charging (ORWC) infrastructureto reducing charging time and utilizing renewable energy within a smart city framework. This study develops a prototype of the ORWC system and examines its techno-economic and environmental benefits. Moreover, the study also evaluates annualized energy share, energy economics, and cost-effectiveness. The results of the proposed study indicate that the ORWC system in combination with RERs, effectively reduces the cost of energy from $0.112/kWh to $0.30/kWh and lowers carbon emissions from 76.9 tons/year to 29.5 tons/year. Furthermore, the results also reveals optimal energy distribution among different energy resources PV, BESS, and the grid. These results highlight that ORWC infrastructure can reduce peak load demand on existing grids and enhance the power density of EV charging systems. This has potential implications for future-oriented fast charging stations and policy development to support the widespread adoption of EVs.

Unobstructive and safe-to-wear watt-level wireless charger

A wearable microgrid that centralizes and distributes harvested energy across different body regions can optimize power utilization and reduce overall battery weight. This setup underscores the importance of developing cable-free wireless power transfer (WPT) systems for mobile and portable devices to eliminate the risks posed by wired connections, especially in dynamic and hazardous environments. We introduce a thin, stretchable, and safe hand band capable of watt-level wireless charging through the widely adopted Qi protocol operating at 130 kHz. The implementation of non-adhesive fabric encapsulation serves to protect the 50-μm-thin spiral copper antenna from mechanical strain, ensuring an overall hand band stretchability of 50%. We also create a stretchable “Ferrofabric”, characterized by a magnetic permeability of 11.3 and a tensile modulus of 75.3 kPa, that provides magnetic shielding for the antenna without compromising wearability. The “Ferrofabric” improves the coil inductance but induces core loss in AC application. By fully understanding and managing loss mechanisms such as the skin effect, proximity effect, core loss, and joule heating, we achieve a wireless charging efficiency of 71% and power delivery of 3.81 W in the kHz frequency range. Our WPT hand band is unobstructive to hand motion and can charge a handheld smartphone as fast as a desktop charger or power a battery-free chest-laminated e-tattoo sensor, with well-managed thermal and electromagnetic safety. Through a holistic electromagnetic, structural, and thermal design, our device culminates in a safe, rugged, and versatile solution for wearable WPT systems.

Modeling EV dynamic wireless charging loads and constructing risk constrained operating strategy for associated distribution systems

Dynamic wireless charging (DWC) is an emerging technology that enables the charging of electric vehicles (EVs) while they are in motion. However, previous load modeling methods have not thoroughly explored the detailed analysis of DWC load characteristics. Existing research only considers the single-node supply mode for dynamic wireless charging roads (DWCRs), and the assessment of operational risks arising from the uncertain DWC loads has not been addressed. This paper begins by conducting an equivalent circuit analysis of a typical EV DWC system with multiple segmented coils. We present a more accurate trapezoidal power model for a single EV. Subsequently, we model the aggregated EV DWC load, accounting for traffic flow and headway using Poisson and negative exponential distribution functions, respectively. In the operation process, we consider a multi-node supply mode for DWCRs. To address the inaccuracy of long-term predictions, we propose a rolling optimization model to coordinate DWC and renewables with heterogeneous uncertainties by introducing a risk metric to manage potential uncertain risks. The proposed optimization model is transformed into a mixed-integer second-order cone programming (MISOCP) problem after convex relaxation. Finally, we conduct case studies to validate the proposed methods.

Flexible Constant-Power Range Extension of Self-Oscillating System for Wireless In-Flight Charging of Drones

Flexible Constant-Power Range Extension of Self-Oscillating System for Wireless In-Flight Charging of Drones

Enabling Continuous Operation of Shared Autonomous Vehicles With Dynamic Wireless Charging

Enabling Continuous Operation of Shared Autonomous Vehicles With Dynamic Wireless Charging

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

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