Compact, Safe and Efficient Wireless and Inductive Charging for Plug-In Hybrids and Electric Vehicles

In magnetically coupled wireless charging systems for electric vehicles, it is common for metal objects to enter the charging system. In this case, the strong magnetic field of wireless charging causes an eddy current effect in the metal object, which generates a large amount of heat. This heat accumulation poses a risk of fire. In this paper, a novel metal object detection system designed for wireless charging of electric vehicles is proposed. The system utilizes the principle that the coil impedance and coupling coefficient change with the presence of metal objects, and a set of composite coils is designed to improve the sensitivity of detection. The detection coil and feedback coil in the composite coil are decoupled by reverse series connection. An LC oscillating circuit based on transformer feedback is used to detect metal objects, and the circuit can make good use of the parameter changes of the composite coil. Finally, an experimental platform for wireless charging metal detection in electric vehicles has been built to validate the proposed system. Through testing, it has been demonstrated that the system can detect the presence of metal objects in a timely and accurate manner.

This paper designs, analyzes and optimizes the electric vehicle wireless charging system and its control method. Compared with the traditional plug-in conduction charging, wireless charging is more convenient, safe, reliable and has better environmental adaptability. Inductive power transmission technology (IPT) is the main technology for wireless charging of electric vehicles and plug-in hybrid vehicles. Based on the fundamental approximation method, the critical self inductance of the primary or secondary coil is derived in this paper. This critical value reflects the power transmission capacity and control performance of the two chargers when they are interoperable. Compared with the non integrated structure, the magnetically integrated LCC compensated wireless charging system can transmit the same power with smaller compensation inductance. Based on the voltage dependent dynamic state space model, four working modes of magnetically integrated LCC compensated wireless charging system are studied in this paper. Simulation and experimental results show that the voltage dependent equivalent circuit model can be effectively applied to the basic characteristic analysis of wireless charging system. The voltage dependent dynamic state space model is more accurate and realistic. In addition to reflecting the basic characteristics of the wireless charging system, it can also reflect the working mode of the wireless charging system.

The charging plate creates magnetic fluxing. The charging plate and the adjacent coil can induce current without any contact. By the new trends, wireless charging got more social attention to the outside world as an alternative method for primitive wired charging. Even though wireless charging was implemented to various electronics industries, it is still proven that wired charging is faster than the wireless. But can make the gadget hot, which may not be good for the battery efficiency. The wireless charging does not degrade the battery. A vehicle that is powered by an electric motor rather than a typical petrol or diesel engine is referred to as an electric vehicle. The electric motor is powered by rechargeable batteries. In this article, the dynamic wireless charging of electric vehicles introduces a new methodology of charging even when the vehicle is in motion. The dynamic wireless charging is proposed to allow power transfer to the electric vehicles when they are in motion. Multiple inductive pads should be buried under the roadways. The inductive pads should be energized by a power supply. The track which is dedicated for the wireless charging should have enough distance so that the vehicles can charge up to a stable value until they leave the charging track. This proposed methodology reduces unnecessary time wastage for charging of vehicles. Hardware results obtained the primary pads mounted on road and power supply for primary roads. Besides, it will flow the efficient inductive power transfer and time saving opportunity.

This paper presents the design, simulation, and experimental validation of a constant current–constant voltage (CC–CV) wireless electric vehicle (EV) charging system utilizing Power Balance Control (PBC) in both primary-side (PS) and secondary-side (SS) converter configurations. The system was tested using a step-resistance load and a typical 72 V, 50 Ah lithium-ion NMC battery to assess control precision, dynamic behavior, and charging efficiency of the system. Experimental results demonstrate that both PS and SS converters employing PBC successfully achieve stable CC–CV operation. The SS converter achieved a peak efficiency of 82%, outperforming 77% from the PS converter. Regarding transient performance, the PBC significantly enhanced settling times over the conventional proportional–integral (PI) controller. Specifically, the settling time was reduced from 600 ms to 100 ms in the PS converter and from 400 ms to 200 ms in the SS converter, with minimal voltage overshoot. Power loss analysis indicated that the highest losses occurred in CC mode, particularly in the inductive power transfer (IPT) coils and high-frequency inverters. The SS control effectively minimized these losses by dynamically adjusting its input resistance to match the optimal load resistance. Overall, the proposed PBC approach, especially in the SS converter, demonstrates efficiency, faster dynamic response, and robust power regulation for next-generation wireless EV charging systems.

Wired charging of electric vehicles comes with certain challenges and difficulties, such as handling bulky cables, risk of damage and compromised safety due to harsh climatic conditions such as heavy rain, wind or snow, and even vandalism. Wireless charging of electric vehicles is gaining prominence because it can mitigate the aforementioned challenges and difficulties and can also operate at the same power transfer efficiency as wired methods today. To design and optimize magnetically coupled coils of a wireless charging system for electric vehicles, numerous simulations utilizing the finite element method (FEM) need to be performed for the estimation of several parameters. This process is time-consuming and computational resource- intensive. In this paper, a real-time approach for obtaining quick estimated results for coupled coil parameters in an 11-kW wireless charging system for electric vehicles is presented. The proposed hybrid approach utilizes fitted curves obtained from the results of a single three-dimensional (3D) FEM simulation for a set of parameters and combines them with polynomial equations in order to estimate the values of the self-inductances of the coupled coils, their mutual inductance, the coupling coefficient and the power transfer efficiency of the wireless charging system. An experimental verification is conducted to compare the coupling coefficient values obtained from the real-time estimator with the measured coupling coefficients of an 11-kW wireless charging system laboratory prototype. The measured values of the coupling coefficient closely correlate with those predicted by the real-time estimator with a median error of 2.133%. Thus, the proposed approach opens up a new way for real-time estimation of parameters for coupled coils, which can save time during the initial developmental stage of an 11-kW wireless charging system for electric vehicles.

Wireless charging station (WCS) enables in-motion charging of the electric vehicles (EVs). This paper presents the short-term operation of WCS by capturing the interdependence among the electricity and transportation networks. In the transportation network, the total travel cost consists of the cost associated with the travel time and the cost of utilized electricity along each path. Each EV takes the path that minimizes its total travel cost. In the electricity network, the changes in WCS demand as a result of changes in the traffic flow pattern impacts the price of electricity. The changes in the price of electricity further affect the charging strategy of the EVs and the associated traffic flow pattern. The coordination between electricity and transportation networks would help mitigate congestion in the electricity network by routing the traffic flow in the transportation network. The presented formulation leverages decentralized optimization to address the economic dispatch in the electricity network as well as the traffic assignment in the transportation network. The presented case studies highlight the merit of the presented model and the developed algorithms for the coordinated operation of WCS in electricity and transportation networks.

Currently, the tram and tanker markets are competing fiercely, and whether wireless charging for electric vehicles can be successfully promoted in the future depends largely on whether the tram market can gain an advantage. Wireless charging has developed to the point where the overall system is not too perfect, so optimising the power system and developing more efficient and safer wireless charging methods is necessary. This paper introduces the basic principles of wireless energy transmission technology and some of the wireless charging methods. The two wireless charging methods of microwave electric power wireless charging and magnetic coupling resonant wireless charging are introduced in principle and the advantages and disadvantages are compared. The safety of wireless charging is maintained, and today's lifestyle is analysed to provide different charging methods for different people. The paper also gives the corresponding measures for the various kinds of dangerous situations that may occur. Finally, the paper gives an outlook and conclusion for the future of wireless charging.

Wireless power transfer is a promising method to address the concerns over charging an electric vehicle. Since wireless charging stations operate without large cables or above-ground stations, they can be conveniently installed in public locations without the risk of vandalism or weather-inflicted damage, improving the lifespan of the electric vehicle charging station. In order for wireless charging stations to become widespread, possible health effects regarding exposure to the strong electromagnetic fields present during wireless power transfer must be investigated. This work examines, first, the potential human safety hazards, second, the electronic device interference, and, third, the thermal heating effects of wireless charging systems. A 3.3 kW wireless power transfer prototype was built in order to examine these effects. Changes in the wireless power transfer efficiency due to the coil misalignment were also investigated using an automated three-axis platform. Design considerations for electric vehicle wireless charging systems and safety recommendations are presented.

Dynamic wireless charging of electric vehicles (EVs) aims at increasing EV range and reducing battery size and associated costs. Moreover, it minimizes the need for recharging stops, thus increasing travel comfort. As electrification of transport ultimately targets CO2 emissions reduction, increased utilization of renewable energy sources is likely to provide the means for reaching the decarbonization objectives. Demand-side management (DSM) enables the increased penetration of intermittent power sources by providing techniques that ensure grid stability. While complete frameworks for DSM deployment in static charging have been designed, these approaches must be re-evaluated with focus on the operational requirements for dynamic EV charging. In this paper, a review of DSM methods targeting static charging is made and one particular case of DSM is simulated in a dynamic charging environment in order to reveal critical aspects towards deployment.

In modern era, in electric vehicles charger regularization, the following phase to make the charging procedure more convenient is to eradicate the usage of wired cable sandwiched by linking the electric vehicles and charger to accomplish wireless charging of electric vehicles, and a wireless power transfer (WPT) system ought to be depicted with respective ground clearance of electric vehicle. It is an innovation technology which can be applied for all electric vehicles (EVs) as it helps to get rid of user involvement. The crucial impediment for acquiring wireless charging is ground clearance which downgrades the power transfer efficiency. The theory of WPT for different ground clearance is elucidated, and the corresponding cordless charger device is analysed. The portrayed cordless charger device has capacity to distribute the power of about 45v utmost ground clearance of 20 cm. The battery designed is 4.5KWh and the super capacitor (SC) of 3.8KWh which is sufficient to charge electric vehicle.KeywordsElectric vehicleWireless power transferGround clearancePower converterVehicle charging

This article describes possible scenarios for wireless charged electric vehicles, as they are discussed within the UNPLUGGED project. It gives a brief introduction into wireless technology and explains the three possible implementation steps for charging electric vehicles: stationary, static en-route and dynamic en-route. Based on these scenarios the impact of wireless charging on future mobility, especially in urban environments is discussed.

With the electric vehicle (EV) market growing fast, the emerging wireless EV charging technology has attracted more and more attention in recent years. As a key part of wireless charging system for EVs, the coil design is indispensable for improving the system performance. This paper presents an overview of coil designs for wireless charging of EVs, which addresses their basic structures, operating principles, and distinct features. The basic topologies including the circular rectangular pad (CRP), circular pad (CP), homogeneous pad (HP), double-D pad (DDP), double-D quadrature pad (DdQp), and bipolar pad (BP), are introduced and discussed. Also, the corresponding advantages and limitations of each topology are analyzed and discussed. Besides, some key issues of practical design problems are compared in the coil topologies. Finally, the human exposure issues are revealed.

For the commercialization of wireless electric vehicle (EV) chargers, the metal object detection and coil alignment are needed for the safe and efficient operation of chargers. This paper proposes a dual-purpose method for the simultaneous metal object detection and coil alignment using a planar coil array before the start of wireless EV charging. Magnetic induction tomography is adopted to reconstruct the images of metal objects and the location of the objects is calculated using the image processing algorithms. The receiving coil in the EV is visualized using the induced voltage map from the coil array and the coil position is computed using characteristic points of the map. Firstly, the structure of the coil array is optimized using the finite element model (FEM) and 4×4 coil elements are used. Then the FEM simulation is conducted for the feasibility study of the proposed method. Finally, an experimental setup of the wireless charging is designed for further verification. For the metal object detection, eight experimental cases prove that the proposed method is able to detect and visualize metal objects with different numbers and different shapes. In addition, the maximum location error for all metal objects is 6.27 mm. For the coil alignment, the location error of the receiving coil is less than 2 cm. The proposed method can help to remove metal objects and assist the driver during the parking, which meets the requirement for the wireless EV charging.

In order to shorten the wireless charging time of electric vehicles (EVs) and achieve stable charging, an adaptive smart control method for EV wireless charging is proposed in the paper. The method dynamically tracks the rechargeable battery state during the whole charging process, realizes multi-stage charging of constant current (CC) or constant voltage (CV) by switching two kinds of compensation networks of bilateral L3C and L3C-C, and regulates the charging voltage and current to make it as close as possible to the battery charging characteristic curve. This method can be implemented because the voltage source connected to the coupler and the compensation networks of bilateral L3C and L3C-C have the CC and CV source characteristics, respectively. On the basis of the established adaptive smart control system of EV wireless charging, the experiments of wireless data transmission and adaptive smart charging were conducted. The results showed that the designed control system had a response time of less than 200 ms and strong anti-interference ability and it shortened the charging time by about 16% compared with the time using traditional charging methods, thereby achieving a fast, stable, safe, and complete wireless charging process.

The economic viability of on-road wireless charging of electric vehicles (EVs) strongly depends on the choice of the inductive power transfer (IPT) system configuration (static or dynamic charging), charging power level and the percentage of road coverage of dynamic charging. In this paper, a case study is carried out to determine the expected investment costs involved in installing the on-road charging infrastructure for an electric bus fleet. Firstly, a generic methodology is described to determine the driving range of any EV (including electric buses) with any gross mass and frontal area. A dynamic power consumption model is developed for the EV, taking into account the rolling friction, acceleration, deceleration, aerodynamic drag, regenerative braking and Li-ion battery behavior. Based on the simulation results, the linear dependence of the battery state of charge (SoC) on the distance traveled is proven. Further, the impact of different IPT system parameters on driving range is incorporated. Economic implications of a combination of different IPT system parameters are explored for achieving the required driving range of 400 km, and the cost optimized solution is presented for the case study of an electric bus fleet. It is shown that the choice of charging power level and road coverage are interrelated in the economic context. The economic viability of reducing the capacity of the on-board battery as a trade-off between higher transport efficiency and larger on-road charging infrastructure is presented. Finally, important considerations, like the number of average running buses, scheduled stoppage time and on-board battery size, that make on-road charging an attractive option are explored. The cost break-up of various system components of the on-road charging scheme is estimated, and the final project cost and parameters are summarized. The specific cost of the wireless on-road charging system is found to be more expensive than the conventional trolley system at this point in time. With decreasing battery costs and a higher number of running buses, a more economically-viable system can be realized.