Wireless Electric Vehicle Charging System Research Articles

Solar wireless electric vehicle charging system

vehicles (EVs) are increasingly prevalent on roads today. These vehicles have demonstrated their effectiveness to minimize travel costs through transitioning from traditional fuel sources to electricity, that is notably more cost-efficient, alongside the associated environmental benefits. The primary aim is to implement a charging system that accommodates extended vehicle usage by applying higher charging rates for prolonged periods. Presently, the prevailing charging infrastructure for EVs involves conductive methods where the vehicle connects to a charging station; however, this process typically takes longer. Advancements in technology are introducing wireless charging solutions. Inductive EV charging, a wireless alternative, eliminates the need for physical wires. This innovative approach proposes charging electric vehicles while they are in motion, eliminating the necessity for vehicles to stop for refueling. Notably, this charging mechanism operates on solar energy, obviating the requirement for an exterior source of power. The system-design encompasses the utilization of various components such as batteries, transformers, solar panels, copper coils, regulator circuits, ATmega328p controllers, AC to DC converters, and the LCD.

Recent Results in Shielding Technologies for Wireless Electric Vehicle Charging Systems

Recent Results in Shielding Technologies for Wireless Electric Vehicle Charging Systems

Recognizing Multitype Misalignments in Wireless EV Chargers With Orientation-Sensitive Coils: A Data-Driven Strategy Using Improved ResNet

In wireless electric vehicle charging systems, misalignments between ground-assembled transmitter and vehicle-assembled receiver are undesirable but inevitable, which may cause efficiency deterioration and even thermal risks. The recognition of horizontal misalignment, including that in the longitudinal and lateral direction, has been made gradual progress by previous works. While yaw angle, with rare attention, can also degrade the charging performance, especially for those employing non-centrosymmetric coupling coils, such as rectangular coils. In this paper, a data-driven strategy based on improved ResNet is proposed to recognize the above multi-type misalignments simultaneously, which is accurate, reliable, and of practical and general value. Large-scale data is sampled using the proposed detection coils by double-group cooperation, which features high sensitivity to the misalignments of all kinds, especially yaw angle. Benefit to the compression technique in the pre-processing phase, the number of training data and labels can be successfully reduced by 3/4. As the core algorithm of the overall strategy, the adaptive channel parameter recalibration ResNet (ACPR-ResNet) can effectively perceive slight differences among similar input samples and map them to proper labels. This is achieved by an adaptive operation of nonlinear transformation and recalibrated importance of channel features during the training process. The effectiveness of the proposed strategy is verified experimentally using a 6.6-kW prototype. Within the 24×24 cm range, 95.2% of the test cases have an error of less than 1.7 cm when recognizing horizontal misalignment, and 91.7% of the test cases have an error of less than 1.5° when recognizing yaw angle.

Solar wireless electric vehicle charging system

Solar wireless electric vehicle charging system

An Inherent CC-CV Charging Architecture for Dual Receiver Semi-Dynamic Resonant Inductive Wireless Electric Vehicle Charging System

An Inherent CC-CV Charging Architecture for Dual Receiver Semi-Dynamic Resonant Inductive Wireless Electric Vehicle Charging System

Modeling EV Charging Station Loads Considering On-Road Wireless Charging Capabilities

Electric vehicle (EV) customers are expected to charge EV batteries at a rapid EV charging station or via on-road wireless EV charging systems when possible, as per their charging needs to successfully complete any remaining trips and reach their destination. When on-road wireless EV charging systems are considered as an alternative charging method for EVs, this can affect the load of a rapid EV charging station in terms of time and magnitude. Hence, this paper presents a probabilistic framework for estimating the arrival rate of EVs at an EV rapid charging station, considering the availability of on-road wireless charging systems as an alternative charging method. The proposed model incorporates an Electric Vehicle Decision Tree that predicts the times when EVs require rapid charging based on realistic transportation data. A Monte Carlo simulation approach is used to capture uncertainties in EV user decisions regarding charging types. A queuing model is then developed to estimate the charging load for multiple EVs at the charging station, with and without the consideration of on-road EV wireless charging systems. A case study and simulation results considering a 32-bus distribution system and the US National Household Travel Survey (NHTS) data are presented and discussed to demonstrate the impact of on-road wireless EV charging on the loads of an rapid EV charging station. It is observed that having on-road wireless EV charging as complementary charging to EV charging stations helps to significantly reduce the peak load of the charging station, which improves the power system capacity and defers the need for system upgrades.

Static and dynamic wireless charging system for electric vehicle

Electrified transportation will help to reduce greenhouse gas emissions and petrol prices. Electrified transportation demands that a wide variety of charging networks be set up, in a user-friendly environment, to encourage adoption. Wireless electric vehicle charging systems (WEVCS) can be a potential alternative technology to charge electric vehicles (EVs) without any plug-in problems. This paper outlines the currently available wireless power transfer technology for EVs. In addition, it also includes wireless transformer structures with a variety of ferrite shapes, which have been researched. WEVCS are associated with health and safety issues, which have been discussed with the current development in international standards. Two major applications, static and dynamic WEVCS, are explained, and up-to-date progress with features from research laboratories, universities, and industries is recorded. Moreover, future upcoming concepts-based WEVCS, such as ‘‘vehicle-to-grid (V2G)” and ‘‘in-wheel” wireless charging systems (WCS) are reviewed and examined, with qualitative comparisons with other existing technology.

Design optimization of electromagnetic shielding and charging efficiency for electric vehicle wireless charging system

Electric vehicle (EV) technology is rapidly advancing, yet the wireless charging system for EVs still faces challenges in terms of insufficient charging efficiency and electromagnetic safety. To overcome these obstacles, this study proposes a novel approach by integrating the double-ended charge-level capacitance charging model with a composite electromagnetic shielding scheme, resulting in the charge-level capacitance composite shielding charging model. Experimental verification confirms the effectiveness of the proposed composite electromagnetic shielding model, demonstrating superior shielding performance compared to conventional models. Furthermore, performance analysis of the suggested charge-level capacitance composite shielding charging model reveals a disk loss of 0.087 W, a transmission efficiency of 98.25%, and a magnetic induction strength of 9.09 T. Collectively, these comprehensive findings indicate that the proposed charging model offers enhanced charging performance and electromagnetic shielding capabilities, surpassing those of traditional models, and holds practical value for real-world implementation.

Solar Wireless Electric Vehicle Charging System

Solar Wireless Electric Vehicle Charging System

Wireless Electric Vehicle Charging System

Wireless Electric Vehicle Charging System

Review of Wireless Charging System: Magnetic Materials, Coil Configurations, Challenges, and Future Perspectives

Electric transportation will assist in lowering emissions of greenhouse gases and mitigating the impact of rising petrol prices. To promote the widespread adoption of electric transportation, a diverse range of charging stations must be established in an atmosphere that is friendly to users. Wireless electric vehicle charging systems are a viable alternative technology that can charge electric vehicles (EVs) without any plug-in issues. Wireless power transfer (WPT), which involves the transmission of electricity via an electromagnetic field despite the presence of an intervening area, holds out the possibility of new prospects for EVs to increase environmentally responsible mobility. This review article examines the WPT technology and how it might be applied to electric vehicles from both a technical and safety standpoint. The prime aim of this review is (1) to illustrate the current state of the art in terms of technological advances as well as research limitations in the field of WPT development and use within the field of transportation; (2) to organise the experimental the deployment of WPT EV systems in the actual world; and (3) to analyse the results over a sustainable period and to identify limitations as well as chances for growth. From a technical point of view, the progress that has been made on the selection of material for designing coils, different types of coils with a specific focus on the overall performance of the system. As a result, this study aims to provide an extensive overview focusing on the magnetic materials and the architectures of the transmitter and receiver pads.

An Antioffset Electric Vehicle Wireless Charging System Based on Dual Coupled Antiparallel Coils

Wireless power transfer (WPT) has the advantages of safety, convenience and freedom from the impact of the environment. Misalignment tolerance is a major issue for the electric vehicle wireless charging system. In this letter, a WPT system with anti-offset characteristic is proposed based on dual coupled transmitting coils with antiparallel windings, forming the inductor-capacitor-capacitor-series (LCC-S) topology. The T-shaped equivalent circuit is developed to obtain the decoupling circuit. Based on the misalignment tolerant characteristic of the antiparallel windings, the two transmitting coils are designed to have the same coil structure with antiparallel windings, leading to the same variation trend of the coupling between the two transmitting coils and the receiving coil and the opposite influence on the output. Therefore, the output voltage can be stable within a certain misalignment range. An experimental prototype is built to verify the effectiveness of the proposal. The experimental results show that the output voltage can remain stable within the range of −150 mm to 150 mm in the horizontal direction and 80 mm to 160 mm in the vertical direction.

Bipolar Checkerboard Metal Object Detection Without Blind Zone Caused by Excitation Magnetic Field for Stationary EV Wireless Charging System

Metal object detection (MOD) technology provides a guarantee for the safe operation of electric vehicle (EV) wireless charging system. To solve the problem of detection blind zone caused by excitation magnetic field in the existing MOD technology, a bipolar checkerboard MOD technology is proposed. By adding an excitation source, not only the blind zone is eliminated, but also it makes the EV wireless charging system and the MOD system work independently. Firstly, the positions and causes of the blind spot caused by the excitation magnetic field of the Tx coil in the EV wireless charging system are analyzed. Secondly, the structure and principle of the bipolar checkerboard MOD system are analyzed. Thirdly, a definition of the detection sensitivity of MOD is given, and the relationship between sensitivity and the size parameters of bipolar checkerboard sensing coil sets is analyzed.Moreover, the parameter optimization method of the sensing coil sets and detection circuit is analyzed. Finally, a MOD system experimental setup is built to verify its feasibility. The results show that the highest sensitivity can reach 20% for a square aluminum plate of 80×80×1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> without a blind zone and the two systems can work independently with each other.

A Minimum ZVS Current Control Strategy of Semi Bridgeless Active Rectifier for Wide Operation Range Based on LCC-S Compensated WPT System

To meet the requirement of the battery charging characteristics and electric vehicle interoperability, wide power range and wide voltage range are important for the wireless electric vehicle (EV) charging system. Hence, ensuring zero voltage switching (ZVS) and high efficiency over the wide operating range is a hot issue but not well resolved. To address the current state of research, an efficiency-oriented control strategy is proposed for LCC-S compensated Wireless Power Transfer (WPT) system to achieve minimum ZVS current over a wide voltage and power regulation range. Based on the accurate harmonic-considered time-domain model, a universal design method for system parameters under the worst ZVS current conditions within wide operation range is proposed. Then, the universal explicit expression at the unit voltage gain point is given. Moreover, based on the simplified fitting method of piecewise bi-quadratic interpolation (PBQI), minimum ZVS current and minimum non-active current can be ensured over the full output voltage and output power range. A 3.3 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> W prototype has been built to verify that the converter can realize ZVS within the whole voltage range, the measured peak efficiency is about 95.2%.

Blind-Zone-Free Metal Object Detection for Wireless EV Chargers Employing DD Coils by Passive Electromagnetic Sensing

Metal object detection (MOD) is crucial for the safe operation of ground-assembled wireless electric vehicle charging (WEVC) systems. Electromagnetic sensing by passive coils is a reliable MOD method for high-power applications, such as WEVC. Previous designs of sensing coils are mainly targeted at the systems with unpolarized coils (e.g., circular coils). However, they are not suitable for those with DD-coil-coupling engaged due to the fundamentally different field pattern. To fix this problem, in this article, a field-oriented design of sensing coils is proposed, which mainly aims at blind-zone elimination while maintaining high sensitivity and cost-effectiveness. The blind zone arising from axial symmetry of the field is removed by size-modulated C-shape coil units. And removing the central blind spot relies on an extra patch coil by utilizing the characteristic of parallel magnetic flux generated by DD coils. Tested by 13 positions (central blind spot excluded) where MOs might exist using a 3-kW WEVC prototype, the optimized sensing coils completely remove the axial blind zones when 50 mV is set as the threshold voltage. Moreover, for the central blind spot, the proposed patch coil can stably identify MO intrusion no matter if the prototype operates in light-load or heavy-load conditions.

Design and Implementation of a PV-Fed Grid-Integrated Wireless Electric Vehicle Battery Charger Present in a Residential Environment

The power transfer technique used to charge electric vehicles (EVs) has gone through a large development lately. Developing a purely autonomous vehicle has motivated researchers to implement the wireless power transfer technique to charge the EV battery. Previously developed EV used a pure grid-dependent charging system, increasing the net energy consumption from the grid. The vehicle weight also reduces the vehicle's reliability with the increase in the size of the battery. This limitation is eliminated by the proposed technique that uses a wireless EV battery charging system with a utility grid. This article presents an improved system for supplying photovoltaic (PV) power to an EV used in a grid-interfaced residential system. This power electronic converter-based interfacing system facilitates a bidirectional power flow technique for feeding extra PV panel power to the grid and charging the EV using utility grid power during the unavailability of solar power. A bidirectional cycloconverter is employed, which delivers a variable frequency concerning modes of operation of the system. The experimental prototype employs an opal-RT real-time simulator for integrating the proposed system into the grid. This article presents the comparison of the simulation and experimentation results of the wireless EV charging system.

Thermal Estimation and Thermal Design for Coupling Coils of 6.6 kW Wireless Electric Vehicle Charging System

Wireless electric vehicle charging technology is developing in the direction of high power levels. However, more generated heat brought by higher power will accelerate the system’s aging and can even lead to damage. An excellent thermal design for the magnetic coupler can reduce each part’s maximum temperature, ensuring long-term operation reliability. Therefore, in this article, the magnetic coupler’s thermal estimation and design are studied based on a 6.6 kW wireless electric vehicle charging system. First, the calculation method of internal resistance of a litz coil, core loss, and eddy current loss of a shielding aluminum plate are studied. Considering the influence of thermal fields on material properties, each part’s power loss calculation formula is further modified to improve the accuracy. After that, heat dissipation research is carried out. The heat dissipation measures, such as filling the surface of the shielding aluminum plate with thermal conductive silicone grease, are proposed. Finally, the effectiveness of the heat dissipation measures is verified by simulation and experiments. The experiment shows that the error between the power loss value of each part calculated by simulation and measured by the experiment is less than 15%, and the maximum temperature of the magnetic coupler is controlled below 80 °C.

Human Exposure Influence Analysis for Wireless Electric Vehicle Battery Charging

Wireless charging schemes aim to counter some drawbacks of electric vehicles’ wired charging, such as the fact that it does not encourage mobility, leads to safety issues regarding high voltage cables, power adapters high cost, and has more battery waste by companies. In this paper, a comparative study of wireless power transfer multiple coil geometries is performed to analyze the efficiency, coupling coefficient, mutual inductance, and magnetic flux density production for each geometry. Results show that coil geometry, current excitation, and shielding techniques within the Wireless Electric Vehicle Charging (WEVC) system substantially influence magnetic flux leakage. In addition, the paper proposes an analytical framework for a WEVC scheme via electromagnetic resonance coupling. Safety considerations of the WEVC system, including the effects on humans, are investigated in several scenarios based on the relative location of the human while EV charging is conducted as the leading paper’s goal. The exposure measurements are performed across various radial distances from the coils using 3-D FEA ANSYS Maxwell Software (American technology company, Pennsylvania, United States). The analysis shows that WEVC systems can achieve high power transfer, resulting in increased magnetic flux leakage around the coils. The safe distance for humans and animals during the charging sequence is attained from research results. For instance, in the 120 mm spiral coil, 120 mm square coil, and 600 mm spiral coil operating at 1 A, excitation, the SAR levels are under the threshold of 700 mm away from the coils. For the 600 mm spiral coil excited at 8 A, the SAR levels fall under the threshold at 900 mm away from the coils. When shielding is utilized, the safe distance is improved by up to 350 mm. Considering the regulations of the Non-Ionizing Radiation Protection (ICNIRP) standards, 600 mm is a safe distance away from the coils, and, vertically, anywhere past 300 mm is safe for humans.

3-D Analytical Model of Bipolar Coils With Multiple Finite Magnetic Shields for Wireless Electric Vehicle Charging Systems

The bipolar pad is one of the most promising topologies in inductive power transfer (IPT) systems for electric vehicles. However, there is scant literature on the analytical model of the bipolar pad. In this article, a three-dimensional (3-D) analytical model of the IPT system including a bipolar transmitter and a square receiver is developed based on the superposition of two 2-D subdomain analytical models. Ferrite and the aluminum shields with finite dimension are taken into account on the transmitter and receiver sides. An analytical calculation of the mutual inductance is then carried out with respect to the main parameters of the IPT system, namely the dimension of the coils, the conductivity, and the permeability of the shield. Three study cases are demonstrated to highlight how the proposed method can accelerate speed up the pad design process. Calculation results of the proposed model are compared with both a finite-element analysis (FEA) model and experimental measurements, demonstrating that the proposed model is nine times faster than the FEA method. When comparing with the experimental results, computational error of the proposed model is less than 6% in most of the study cases.

Stability Improvement and Overshoot Damping of SS-Compensated EV Wireless Charging Systems With User-End Buck Converters

The multiple fluctuations, such as grid DC input voltage, mutual inductance and the plug-in and plug-out of battery, may lead to instability and deterioration of dynamic performance of electric vehicle (EV) wireless power transfer (WPT) system. The overshoot issue can bring great current stress to EV WPT system, and may induce potential disastrous malfunction of the lithium-ion (Li-ion) battery. This study theoretically reveals the slow dynamic response and large overshoot of a traditional WPT system. For solving these issues, a reliable adaptive feedforward control scheme is proposed and applied in the user-side DC-DC converter, where the communication unit is eliminated. The feedforward loop is proved theoretically to suppress overshoot and system dynamic response. Besides, the feedforward control increases the selective range of control parameters, which can improve the system dynamics. Experiment results verifies that the proposed adaptive feedforward gain allows faster dynamics, and the aforementioned disturbances in EV WPT system can be solved while the system performance is not affected.