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Dynamic wireless power transfer (DWPT) systems with segmented transmitters suffer from output pulsations during the moving process. Although numerous coil structures have been developed to mitigate this fluctuation, the parameter design process is complicated and restricted by specific working conditions (e.g., air gaps). To solve these problems, a novel reverse-bent modular transmitter structure is proposed for DWPT in industrial automatic application scenarios such as linear transport systems. Considering the heterogeneous current density distribution in the adjacent region between two coils which causes a drop in magnetic field, the proposed coil structure attempts to eliminate the effects of the adjacent region by bending the terminal parts of each coil reversely to the ferrite layer for shielding. Compared to traditional planar couplers, this structure array can generate a uniform magnetic field over various air gaps. A 100 W laboratory prototype was built to verify the feasibility of the proposed system. The experimental results show that the proposed system achieved a constant output voltage, and the output pulsation was within ±2.3% in the dynamic powering process. The average efficiency was about 88.29%, with a 200 mm transfer distance. When the air gap varied from 20 mm to 30 mm, the system could still retain constant voltage output characteristics. [ABSTRACT FROM AUTHOR]

Recent advancements in Dynamic Wireless Power Transfer (DWPT) have highlighted the need for further research, particularly in the area of modelling and simulation techniques. As the power transferred between charging pads depends on vehicle position, the load profile of the DWPT is therefore a function of the vehicle's movement which is dependent on user behaviour and is inherently stochastic. For DWPT, these events involve high instantaneous power and are short in duration. To better understand the impact of DWPT, accurate models are required to test control systems and potential solutions. Additionally, these systems require high-frequency simulation for DWPT, which results in long simulation times during development. This paper presents a simplified model for circuit components that eliminates high-frequency switching elements, enabling the use of larger simulation time steps and significantly reducing simulation time. By applying circuit analysis and calculating equivalent impedances, the model provides average circuit values that effectively represent waveform amplitudes without the need to simulate instantaneous, high-frequency variations. To ensure the efficiency of grid-connected simulations and achieve a level of accuracy that reflects the internal dynamics of wireless charging, subsystem simulations demonstrated significant time improvements at the cost of minimal accuracy loss. For DC/DC converters operating at 2 kHz, simulation time was reduced by 3× with only a 1% error. The DWPT subsystem, operating at 85 kHz, achieved an 18× reduction in simulation time with a 2.5% deviation. When combined, the full system resulted in a 30-fold reduction in simulation time with only a 6% deviation from the base model. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The necessity of pushing the road mobility towards more sustainable solutions has become of undeniable importance in last years. For this reason, both research and industry are constantly investigating new technologies able to make the usage of battery electric vehicles(BEV) as accessible and usable as traditional internal combustion engine vehicles (ICEV). One of the most limiting issues concerns the short range of electric vehicles, which complicates their use for long distances, such as for highway travels. A promising solution seems to be the "charge-while-driving" approach, by exploiting the inductive dynamic wireless power transfer (DWPT) technology. Nevertheless, such systems show different issues, first of all, high investment and maintenance costs. Furthermore, it is not clear how extensive a potential dynamic wireless charging infrastructure needs to be to make a real advantage for electric vehicle drivers. As a consequence, the aim of this paper is to introduce a new methodology to estimate the number and length of wireless charging sections necessary to allow the maximum number of electric vehicles to travel a specific highway without the need to stop for a recharge at a service area. Specifically, the methodology is based on a algorithm that, starting by real traffic data, simulates vehicle flows and defines the basic layout of the wireless charging infrastructure. This simulator can provide a decision support tool for highway road operators. [ABSTRACT FROM AUTHOR]

This study introduces a new method for real-time efficiency tracking and stable output power of Dynamic Wireless Power Transfer (DWPT) systems using variable capacitors. A preliminary detailed discussion and an analysis of the DWPT system are carried out to show how the system can optimize power transmission and efficiency when the relative positions of transmitter and receiver change using a dynamic real-time control of the variable capacitors belonging to the compensation networks. This paper shows a detailed model of the DWPT system, including magnetic coupling analysis, circuit dynamics analysis, and efficiency characteristics analysis, in order to modify the control input values as needed. By utilizing a group optimization strategy, the transmission efficiency can be quickly maximized without using a position detection module. Simulation results demonstrate the effectiveness of the proposed method under various dynamic conditions, achieving significant improvements in energy efficiency and transmission reliability of the DWPT system. This research provides a powerful method to increase the overall performances of DWPT systems, which will help the development of future wireless charging technology. [ABSTRACT FROM AUTHOR]

This paper investigates the issue of leakage current at the transmitter in the Dynamic Wireless Power Transfer (DWPT) system for electric vehicles and puts forward a novel bilateral resonant compensation topology structure based on the conventional LCC-S architecture. Based on the LCC-S framework, a circuit model was developed for traditional (unilateral)/bilateral resonant compensation topologies. The Fourier series voltage-to-earth expansions for the power supply rail were deduced for both topologies. Subsequently, the voltage-to-earth waveforms for the power supply rail were obtained by utilizing the Fourier series expansions of the voltage-to-earth and the corresponding circuit simulation models. The results demonstrate the efficacy of the bilateral resonant compensation topology in mitigating higher-order harmonics of the voltage to earth on the power supply rail by effectively suppressing the distortion in the leakage current and minimizing its conduction. The effectiveness of the double-ended resonant compensation topology in suppressing leakage current conduction has been verified through experimental tests and waveform comparisons of the voltage to earth and leakage current on the power supply rail under two different topologies. Through experimental testing, during which the unilateral/bilateral resonant compensation topologies were compared, an analysis was conducted on the waveforms of the voltage to earth and leakage current of the power supply rail. The results verified the effectiveness of the bilateral resonant compensation topology in mitigating the conduction of leakage current. This study provides empirical evidence supporting the use of the bilateral resonant compensation topology for suppressing leakage current in power rail applications. [ABSTRACT FROM AUTHOR]

As electric vehicles (EVs) become increasingly common in transportation infrastructures, the need to strengthen and diversify the EV charging systems becomes more necessary. Dynamic Wireless Power Transfer (DWPT) roadways allow EVs to be recharged while in-motion, thus allowing to improve the driving ranges and facilitating the widespread adoption of EVs. One major challenge to adopt large-scale DWPT networks is to efficiently and accurately develop load demand models to comprehend the complex behavior on power distribution grid due to difficulty in developing power electronic simulations for charging systems consisting of either numerous transmitter pads or high traffic volumes. This paper proposes a novel modified Toeplitz convolution method for efficient large-scale DWPT load demand modeling. The proposed method achieves more accurate modeling of DWPT systems from a few transmitter pads to tens of miles in real-world traffic scenarios with light computational load. Test results for a small-scale DWPT system are first generated to validate the accuracy of the proposed method before scaling to large-scale load demand modeling where real-world traffic flow data is utilized in DWPT networks ranging from 2–10 miles. A comparative analysis is further performed for the scenarios under consideration to demonstrate the efficiency and accuracy of the proposed method.

Maximum efficiency tracking (MET) with multiple concurrently-activated transmitters (TXs) has not yet been investigated thoroughly. This paper proposes a fast real-time estimation of coupling coefficients and load resistance for multiple concurrently-activated TXs and a moving RX. This is the first paper that demonstrates iteration-less, fast, communication-less MET with power regulation when the RX is moving across multiple activated TX array. The controller senses only the voltage magnitude of TX coil-capacitor resonator, and the input DC voltage and DC current of inverter. Once the parameters are estimated, the controller sets the converters to maximum efficiency point immediately. The benefits of proposed method are that it does not require a communication channel, extra circuit components for MET, time-consuming iterations and computations, and periodic interruption of power flow due to load disconnection or initialization, all of which were limitations in typical methods. Experimental results show that the proposed method provides a fast response (3.8ms) for an RX moving at 6.84 km/h across multiple TXs.

Dynamic Wireless Power Transfer (DWPT) is a revolutionary technology for developing an autonomic electromobility transport system. A robust control method is essential for maximum power transfer with high efficiencies and the safe operation of the DWPT systems. This paper developed a frequency domain model of a series-series wireless power transfer system to thoroughly analyze how different control parameters affect the system performances under dynamic situations. For the first time, the power triangle phenomenon associated with the proposed optimum frequencies of a DWPT system is discovered to reveal the causal relationship between frequency, phase shift, and power. The theoretical performances of the proposed optimum frequencies are well aligned with the results of simulation and experiments, with 83% of the normalized root mean square errors less than 2%.

The wide deployment of electric vehicles (EVs) is mainly linked to the extensive development of charging infrastructures. Dynamic wireless power transfer (DWPT) seems to be a viable solution that deals with EV's major challenges such as autonomy. In-motion charging would improve sustainable mobility by reducing storage system weight. However, large power rates are required for such applications since energy transfer must occur quickly and must match the power requirements of various vehicles. The vehicle design, road infrastructure, and electrical network are all affected by this tendency. Power-flow smoothing is essential to eliminate pulsations generated by vehicle motion as well as power peaks caused by the WPT as part of the electrified road system, which have an impact on the total electrical load. In this paper, we present an optimal energy management scheme for the supercapacitor integration in order to meet the WPT demand and reduce the pulsation caused by EV's demand. [ABSTRACT FROM AUTHOR]

Wireless power transfer to electric vehicles while driving is a technology that is currently attracting attention as it has the potential to solve the problems faced by EVs that will become popular worldwide in the future. In the case of dynamic wireless power transfer (DWPT) to electric vehicles, it is necessary to transmit the required power with high efficiency and ensure safety. While there are multiple safety requirements, there are also regulatory values for the magnetic field strength emitted from the coil, which must be satisfied before it can be implemented in society. This research aims to speed up the design of coils by using only numerical analysis, in contrast to conventional coil design using electromagnetic field analysis. In the future construction of wireless power transfer systems, it is of great significance to discuss the design using only numerical analysis, as there are many design parameters. Experiments were carried out and compared with the numerical analysis and found to be in agreement. A power transmission of 20 kW converted value was carried out to verify the effect of the size, pitch, and number of turns of the transmission coils on the efficiency and magnetic field strength. The effect of input voltage was also discussed by simulation, and the optimum coil was derived. As a result, when the coil size was 800 × 600 mm, the number of turns was 46, the pitch was 6.1 mm and the input voltage was 1400 V, the analysis showed that a power transmission of 20 kW with an efficiency of 99.3% and a far magnetic field leakage strength of 81.6 dBμA/m could be achieved. Even with a coreless coil, the magnetic field strength could be below the regulation value. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The current charging technology for electric vehicles consists of plugging the cable from the AC utility to charge the batteries. This requires heavy gauge cables to connect to electric vehicles, which can be difficult to handle, presents tripping hazards, and is prone to vandalism. In addition to these inconveniences, electric vehicles must be immobilized for hours before being fully charged. Dynamic wireless power transfer has been studied worldwide as a promising technology. It is safe and convenient and allows electric vehicles to charge while moving. To improve the efficiency of a dynamic wireless power transfer system, the magnetic coupling coefficient must be maximized between the primary pad, which is integrated into the road, and the secondary pad installed in the electric vehicle. This article presents a parametric optimization of the ferrite structure used for a 3 kW dynamic wireless power transfer prototype. Different ferrite configurations are compared while studying the effect of the parameter values on their magnetic coupling coefficient. Finally, the proposed structure was validated during the experimental test, and its coupling coefficient was improved by 26% compared to the original structure. [ABSTRACT FROM AUTHOR]

This paper investigates the issue of leakage current at the transmitter in the Dynamic Wireless Power Transfer (DWPT) system for electric vehicles and puts forward a novel bilateral resonant compensation topology structure based on the conventional LCC-S architecture. Based on the LCC-S framework, a circuit model was developed for traditional (unilateral)/bilateral resonant compensation topologies. The Fourier series voltage-to-earth expansions for the power supply rail were deduced for both topologies. Subsequently, the voltage-to-earth waveforms for the power supply rail were obtained by utilizing the Fourier series expansions of the voltage-to-earth and the corresponding circuit simulation models. The results demonstrate the efficacy of the bilateral resonant compensation topology in mitigating higher-order harmonics of the voltage to earth on the power supply rail by effectively suppressing the distortion in the leakage current and minimizing its conduction. The effectiveness of the double-ended resonant compensation topology in suppressing leakage current conduction has been verified through experimental tests and waveform comparisons of the voltage to earth and leakage current on the power supply rail under two different topologies. Through experimental testing, during which the unilateral/bilateral resonant compensation topologies were compared, an analysis was conducted on the waveforms of the voltage to earth and leakage current of the power supply rail. The results verified the effectiveness of the bilateral resonant compensation topology in mitigating the conduction of leakage current. This study provides empirical evidence supporting the use of the bilateral resonant compensation topology for suppressing leakage current in power rail applications.

Electric vehicles (EV) are now considered the present and future of road transportation to reduce the emission of CO2 into the environment and thus progressively reduce global warming and climate change. However, EVs currently have some weaknesses such as the available range of battery-powered EVs and the recharging time of the batteries. To overcome these problems, some electrification projects have been proposed for road transportation such as the dynamic wireless power transfer (DWPT), where an EV charges as it moves along an electrified lane using magneto-resonant coupling between short tracks mounted on the road pavement and the vehicle's onboard pickup coils. While the results are encouraging from an electrical point of view, there is concern regarding the magnetic field in the environment produced by the DWPT coils, which can produce adverse health effects in humans and electromagnetic interference (EMI) in electronic devices. The latter also includes implantable medical devices (IMDs) and in particular cardiac implantable electronic devices (CIEDs), which may be present among vehicle passengers and pedestrians in areas surrounding the vehicle. The aim of this study is the numerical analysis of the EMI produced by a DWPT system in CIEDs with leads such as pacemakers, implantable cardioverter defibrillators (ICDs), etc. EMI is mainly produced by the incident magnetic field and the induced voltage at the input port of a CIED; therefore, in this work the magnetic field levels produced by a DWPT system operating at 85 kHz are calculated first, then the voltage at the input port of a pacemaker is evaluated as that produced by the magnetic field incident on the loop surface formed by a lead implanted in the venous system. According to ISO 14117 standard, it is assumed that the lead loop is planar, semicircular in shape and with an area equal to 225 cm2. Since the lead can be placed anywhere where a human can be and with any orientation, an innovative and sophisticated roto-translation algorithm is proposed to find the maximum value of the peak-to-peak induced loop voltage in the most critical regions inside the vehicle cabin and beside the vehicle near the DWPT coils. The preliminary results obtained show that there is no EMI risk inside the vehicle for the passengers with CIEDs, while some concern for pedestrians is due to the induced voltage at the input port of a CIED with unipolar leads which can exceed the ISO 14117 limit in the region next to the vehicle. [ABSTRACT FROM AUTHOR]

Road transport is becoming increasingly electric as it becomes more environmentally friendly. A green transportation system includes solar arrays along the roadside, encouraging the eco-friendly EV charging system. This paper proposes a road-side photovoltaic system to charge the batteries of slow-moving electric vehicles using a five-leg inverter. The five-legged inverter, which utilizes a stand-alone PV system to drive the charging pads, enhances the probability of achieving the sustainability goal. The limitations of the conventional H-bridge inverter, such as its more prominent design and higher number of switches or straightforward design and restricted power level, are addressed by this converter. The proposed 3.3 kW, 85 kHz inverter energizes the four transmitter pads while a receiver pad moves over the transmitter pads and inductively extracts the power. The d.c.-d.c. converter is used to feed the power to the proposed inverter. The P and O-based MPPT algorithm with a tuned PI controller is used to generate the driving pulses of the d.c.-d.c. converter. The signals are generated based on the voltage and current output of the solar panel output. This control algorithm ensures the stability of the system output response. Additionally, the tuned d.c.-d.c. converter achieves maximum efficiency independent of the load resistance. The system maintains constant power transfer profile concerning load resistance variations. The 520*520 mm Double D-pad transmits the power, while the series-series compensation network assists the charging pads in achieving resonance. The developed systems’ nominal charging voltage and current are 144 V, 20 A, with an equivalent battery resistance of 7.2 Ω.

High-density coil installation to achieve a smooth power transfer inevitably increases construction costs, reducing the acceptance of dynamic wireless power transfer (DWPT). In this article, a detuning-repeater-based DWPT system is proposed to provide a relatively constant power at a reduced count of inverters. Half of the inverter-connected transmitter coils in conventional DWPT systems are served as passive repeater coils. The repeater relays the power from the transmitters on both sides to take the role of the main power transfer channel when the receiver is moving towards it. A detuning method is proposed to suppress the standby currents inside the idle repeater coils by utilizing the variation of receiver reflecting impedance during the receiver moving towards/away. An optimization method to achieve less power fluctuation is designed based on the detuning rate. The tradeoff between the power fluctuation and current suppression is analyzed. The system performance against parameter variations is also performed. A 100 W down-sized prototype is developed, and the experimental results show that the proposed DWPT system can achieve a quasi-constant output power with a power fluctuation of 8.5% and a system efficiency of around 82% during the entire dynamic process. [ABSTRACT FROM AUTHOR]

Dynamic wireless power transfer (DWPT) has received extensive attention due to its advantages of high security, high convenience, and high efficiency. To solve the problems of the mutual inductance and output power drop of DWPT systems for inspection robots, a new DWPT system with a trapezoidal-rectangular coupler has been proposed. First, the DWPT system topology and the switching strategy of the transmitting coil are introduced. Second, the real-time mutual inductances of the coupler in linear and curved motion are derived. Third, a new trapezoidal transmitting coil is presented. Finally, the performance of the DWPT system with the trapezoidal-rectangular coupler (TRC) is tested and compared to the DWPT system with the rectangular-rectangular coupler (RRC). Experimental results show that the minimum mutual inductance of the TRC is increased by 58.71%, and that the minimum output power is more than doubled in curved motion. Moreover, the mutual inductance drop rates of the TRC in linear and curved motion are reduced by 21.23% and 18.42%, respectively. The output power drop rates of the TRC-DWPT system are reduced by 18.99% and 16.12%, respectively. In addition, the Litz wire consumption is reduced by 8.28% in linear motion. [ABSTRACT FROM AUTHOR]

In order to improve the mileage per charge of battery electric vehicles (BEV), dynamic wireless power transfer systems are being developed. There are some problems such as is the wide gap between coils when mounted under the floor of a vehicle, and the effect of foreign objects between coils on power transmission. In‐wheel coils, in which the coils are placed inside the wheel, have been proposed as a solution to these problems. However, they a plastic wheel such as CFRP and cannot reduce the gap between coils. In this paper, we propose a coil configuration in which the coils are placed inside the tire and the wheel. This configuration has the advantage of using a conventional aluminum to reduce the gap between coils. The effectiveness of this method is demonstrated via simulations and experiments. [ABSTRACT FROM AUTHOR]

This paper offers a new EF-class converter for dynamic wireless power transfer application. The proposed high-frequency converter employs a floating-frequency switching algorithm to control the converter in a continuous frequency range, eliminate the requirement to any additional operational data from the secondary (receiver) side, accelerate the load impedance match while moving, maximize the transferred power rate, reduce charging interval and compensate power transfer tolerances. Moreover, an optimized super elliptical shape coil is designed to cope with lateral misalignment, enhance coil coupling, and increase efficiency. In the proposed converter, (i) soft switching is implemented to increase switching frequency, decrease passive components size, and improve power density, (ii) undesired voltage harmonics are attenuated to reduce peak voltage stress of the power switch in a wide frequency range, (iii) the receiver side is enabled for higher mobility with stable power transfer, and (iv) the resonant frequency is updated to compensate non-accurate values of passive components in experimental prototyping. In this study, the operational analytics, compensation method, control algorithm, coil design and converter optimization are followed with some comparisons to present the converter capabilities. In addition, simulation and experimental results are provided under different degrees of misalignment to verify the accuracy of theoretical analytics.

For the problem of fluctuation of transmission power and load voltage between magnetically coupled mechanisms in the dynamic wireless power transfer (DWPT) system of the electric vehicles (EV), a magnetically coupled mechanism with dual receiving coils (R-C) of electric energy on the receiving side is proposed in this paper. The transmitting coils (T-C) are connected in parallel in a multi-stage manner flat on the road, and when the EV drives above a section of T-C, this T-C is energized to charge the EV. In the paper, the theoretical model of the circuit and the theoretical model of the magnetic circuit of the dual R-C magnetic coupling mechanism are first established. The feasibility of this structure is verified through the derivation and calculation of the working principle of the system. Finally, the simulation and experimental results verify the effectiveness of the coupling mechanism. The experimental results further demonstrate that the magnetically coupled structure with dual R-C can effectively reduce the power fluctuation during the T-C switching and reduce the laying of T-C to reduce the cost.

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wireless power transfer (WPT) to in-motion electric vehicles can extend the cruising range without additional batteries. Our group has already proposed a novel dynamic WPT system using in-tire and in-wheel repeater coil, which can shorten the air gap between the coils on the road and tire sides. In WPT system, the air gap should be as small as possible from the viewpoint of efficiency and leakage electromagnetic field. However, it is necessary to have a sufficient air gap to avoid coil damage by tire deformation. The maximum tire deformation when overcoming bumps of various heights at different vehicle speeds is experimentally measured with two different tires, normal tire and self supporting runflat (SSR) tire. The measured results show advantages of using SSR tire for the proposed WPT system. [ABSTRACT FROM AUTHOR]

Dynamic wireless power transfer (DWPT) is a promising solution that not only tackles concerns about limited range but also diminishes the need for larger onboard batteries, thus contributing to the genuine sustainability and eco-friendliness of electric vehicles. However, existing DWPT systems encounter several challenges including the large number of compensation components, power loss, and reduction in power throughput due to pad misalignment. This paper aims to address these challenges by utilizing the hybrid inductive power transfer topologies in the DWPT system. A series of DWPT configurations are constructed using hybrid networks, then a hybrid DWPT system incorporating the LCC-S and S-LCC networks is proposed. The misalignment tolerance tuning method is used to tune the resonant network. Conversely, the unipolar rectangular pad is employed for the transmitter and receiver due to its low cost and low complexity. A mathematical model is developed to characterize the hybrid DWPT resonant network, and finite-element analysis is performed for the dynamic charging track. A 75W system is developed and a laboratory prototype is constructed to validate the proposed hybrid DWPT system. With an efficiency of approximately 65%, the output voltage gain fluctuates less than 10% within a literal misalignment of 50%. However, the output power fluctuates nearly 100% with dynamic receiver movement, resulting in null power, which will be addressed in future work. [ABSTRACT FROM AUTHOR]

Dynamic wireless power transfer (DWPT) has attracted widespread attention for its charging flexibility; short-segmented DWPT systems are more suitable for EV charging scenarios because of their higher charging efficiency and lower electromagnetic radiation, compared to long-track DWPT systems. For short-segmented DWPT systems, the structural design of the ground-side coil affects the coupling characteristics of the system, while simultaneously the electric vehicle driving speed and coil arrangement also cause coupling variations, and this will inevitably have an impact on the system's performance. Therefore, this paper demonstrates the coupler design of a short-segmented system for electric vehicles, focusing on the optimization of ground-side coil. The coupling variations causing by driving speed of EV and coil arrangement are taken into account. Considering the tradeoffs and restrictions, a multi-objective optimization process of coils in DWPT systems is proposed based on the Pareto optimizing method, with three objectives: transfer power, high efficiency and low cost. A reasonable optimal solution is selected from the Pareto front to verify the optimizing method through a constructed prototype. [ABSTRACT FROM AUTHOR]

The paper is focused on the optimization of the compensation network of a wireless power transfer system (WPTS) intended to operate in dynamic conditions. A laboratory prototype of a WPTS has been taken as a reference in this work, allowing for the experimental data and all the numerical models here presented to reproduce the configuration of the existing device. The numerical model has been used to perform FEM analysis with variable relative positions of the emitting and receiving coil to simulate the movement in a 'recharge while driving' condition. Inductive lumped parameters, i.e., self and mutual inductances computed from FEM results, have been used for the optimal design of the compensation network necessary for the WPTS operation. The optimal design of the resonance circuits has been developed by defining objective functions, aiming to achieve these goals: transmitted power must be as constant as possible when the vehicle is in movement and the electrical efficiency must be satisfactory high in most of the coupling conditions. The performances of the optimized network are finally compared and discussed. [ABSTRACT FROM AUTHOR]

Laborsaving is a major issue in production. In an automotive production line, a yard that is used as a temporary storage for vehicles before shipping. The vehicle‐loading robot that operates autonomously has been proposed to automate the alignment of vehicles in the yard instead of human driving. In this study, the dynamic wireless power transfer (DWPT) system that includes the structure of the roadside for the vehicle‐loaded robot is proposed. It is proven that the transmitter coil has enough durability for the load of the robot weight using simulation and actual measurement. It is also shown that the reinforcement bars of the road structure cause considerable eddy current loss even with stainless steel. This is similar to loss by coil resistance. This system achieves a 1.8 kW DWPT with an automated coil detection system and a frequency control system, under factory conditions. [ABSTRACT FROM AUTHOR]

Short cruise range is a major issues in electric vehicles, and dynamic wireless power transfer (WPT) has been proposed to solve this problem. In this study, a new dynamic power transfer system is introduced, called the hird generation wireless in-wheel motor, that integrates the drive circuit and motor. Additionally, a methodology of the transmitter and receiver coil design that can calculate inductance and resistance of the rectangular spiral coils in a fast manner is proposed. It considers the theoretical efficiency of coils, current of coils, and voltage of resonance capacitor as constraints. Inductance calculation models only use coordinates of coil edge and the distance between coil and ferrite core. The coils designed by the proposed method were manufactured and evaluated using an LCR meter. The calculation error of the self-inductance and mutual inductance was found to be ± 9%. With the transmitter coil and receiver coil, an output and DC to DC efficiency of is 18 kW and 95.2%, respectively, were obtained by actual WPT test. [ABSTRACT FROM AUTHOR]

Short cruise range is one of the major limitations of electric vehicles. To address this problem, dynamic wireless power transfer has been proposed. However, the eddy current loss in foreign matter is one of the greatest disadvantages of dynamic wireless power transfer. Eddy current loss decreases efficiency of wireless power transfer and increases temperature of the foreignmatter, which causes burning of the combustible materials around the foreign matter in the worst case. Herein, we propose a wireless power transfer system named in-wheel coil wherein the magnetic flus in concentrated in the tires and wheels. In addition, we propose suitablematerials for the tires and the wheels of the system, to reduce the eddy current loss, are proposed using actual measurement data. [ABSTRACT FROM AUTHOR]

The dynamic wireless power transfer system consists of multiple power transmission sectors in parallel with a single inverter circuit for light duty electric vehicles. The use of multiple power transmission sectors reduces power loss. Usually, each power transmission sector needs to use an inverter for every sector but this system uses one inverter to save cost. This article proposed a study of the dynamic wireless power transfer efficiency between the power transmission sector and the power receiver sector. The performance of the proposed dynamic wireless power transfer system was experimented and compared by varying the gap between the power transmission sector and the power receiver sector, and the speed of the electric vehicle at a resonance frequency. The results show that the dynamic wireless power transfer system had a maximum power transfer efficiency of 82.01% at a distance between the power transmission sector and the power receiver sector of 0.10 m, with a speed of 0.28 m/s. [ABSTRACT FROM AUTHOR]

A high efficiency and a constant voltage at the output stage are among the major concerns in wireless charging of dynamic electric vehicles. They are usually achieved by additional converters or asymmetric switching which suffer from high cost and hard switching. To overcome these drawbacks, a variable-frequency retuning approach is proposed in this paper with LCL-Series compensation. As opposed to conventional control methods with resonance frequency as target operating frequency, this approach uses a new optimum frequency which enables ZVS. Also, it minimizes the conduction loss of the inverter switches in a wide range of load and coupling coefficients. In addition, it improves the total system efficiency up to 6% together with an increase in the power transfer capability. Using the proposed method, both sides’ currents increases up to 45% depending on the load. To find the optimum frequency in a system without resonant parameter information, an on-line maximum efficiency search method based on Perturb and Observe is employed. Extensive simulation results using PLECS, together with experimental results from a laboratory setup are presented to confirm the effectiveness of the proposed method under varying load and coupling. [ABSTRACT FROM AUTHOR]

The electrification of the transportation sector poses an opportunity for reducing greenhouse gas (GHG) emissions from passenger vehicles. Electric vehicle (EV) charging through dynamic wireless power transfer (DWPT), known as roadway electrification, could shift EV demand profiles to better coincide with renewable electricity generation. However, this would be a very large new load and few studies evaluate the regional impacts of DWPT charging in a power transmission system. This paper defines methods that address dataset generation for passenger vehicle trips and models to evaluate regional impacts for this emerging technology. Household vehicle miles traveled (VMT) data form localized EV demand profiles through discrete-event simulation. This data serves as exogenous inputs for a Production Cost Model (PCM) of a synthetic transmission system based on the Electric Reliability Council of Texas's (ERCOT) network. EV charging methods are compared for both a 2018 baseline generation mixture and a high-renewable generation case incorporating 20 GW of installed solar photovoltaic (PV) capacity. The PCM employs unit commitment and economic dispatch (UC&ED) models to compare financial, environmental, and grid reliability impacts from EV charging across passenger EV adoption levels. In-transit charging could reduce grid operational costs by as much as 1.49%, with up to $13.7B saved in annual vehicle operational costs for consumers compared to gas-powered vehicles. Health impacts analysis from power plant and vehicle tailpipe emissions from this study show net health benefits increase by 40% for in-transit charging coupled with high renewable generation. Renewable resources provide an avenue for cost-effective in-transit charging with reduced emissions. The combination of dataset generation and open-source power system modeling establish a foundation for the holistic evaluation of regional DWPT impacts. • PEV dynamic charging with increased renewable generation has positive system impacts. • Public data informs vehicle-miles traveled datasets for energy consumption analysis. • In-transit wireless charging from PEVs decreases power system peak demand hours. • In-transit PEV charging aligns with solar power to reduce curtailment and total cost. • Net health benefits from PEVs improve with in-transit charging and renewable sources. [ABSTRACT FROM AUTHOR]

In a dynamic wireless power transfer (DWPT) system for electric vehicles, bipolar transmitting rail is often implemented to improve the misalignment tolerance, but its constraint often lies in fluctuating output. This problem can be mitigated by applying two-phase receivers which, due to its structural characteristics in the impedance matching circuit, bring two new problems: limited range of impedance matching and low efficiency. This paper aims to tackle the two problems by introducing a cascaded topology and its control method. Firstly, the conventional topology of the two-phase receiver is thoroughly analyzed theoretically concerning impedance matching range and efficiency model. Secondly, a cascaded bridgeless rectifier-Buck (CBRB) as impedance matching with 0~ ∞Ω matching capabilities is put forward. Besides, the independent two-channel structure is also introduced leaving the output current ratio the key to efficiency optimization. Thirdly, the control method for the proposed topology using heuristic current ratio by adopting online estimation via auxiliary measurement coils is presented. Finally, experiments are verified on a 20 kW DWPT platform and the proposed topology and control method can raise the transfer efficiency by 3.3% compared with the conventional topology.

Dynamic wireless power transfer brings a refreshing way for charging electric vehicles (EVs) in motion, which can help reduce the amount and bulk of onboard batteries and prolong the vehicle mileage. However, the misalignment between the transmitter coil and receiver coil varies randomly as the vehicle moves, reducing the stability of the output power and the system efficiency. Therefore, a guiding approach is imperative to maintain the coil alignment within an acceptable range. In this paper, a vision-based misalignment detection method is proposed to improve the stability of the system output power and the efficiency. First, the relationships among the system efficiency, output power and mutual inductance were derived in theory. Second, the relationship between the mutual inductance and the misalignment was modeled and simulated using ANSYS Maxwell software. Third, image detection of the ground guideline was used to locate the transmitter coil, and thus obtain the accurate misalignments online. Based on the acquired misalignments, the output power can be rapidly and precisely regulated to the desired value. Finally, the experimental results show that the proposed method can accurately acquire the coil misalignments and then rapidly regulate the system output power in comparison with the conventional discrete proportional-integral control algorithm.

Dynamic wireless charging as viable alternative to plug-in vehicles has contributed to a substantial reduction in stopping time at the charging station. Nevertheless, the sequential charging of electric vehicles can reveal the user's personal information, including their location, by using bill and payment systems. Not only do these systems need to support location privacy, but they also should be traceable by trusted authority when cars are stolen. In this paper, a lightweight and secure payment protocol for dynamic wireless charging of electric vehicles in vehicular cloud have been proposed. In addition, payment system requirements and wireless charging of electric vehicles, including architecture, security, speed, location privacy, anonymity, price flexibility and resistance to possible attacks have been described. Low-cost operations like XOR and concatenation have been used to achieve security and speed. The performance and security of LSPP, based on both formal analysis using AVISPA tool and informal analysis considering probable attack scenarios have been analyzed and compared with past methods. In conclusion, with regard to security and efficiency, payment system proposed works well and fulfills the requirements of the wireless charging of electric vehicles.

Wireless power transfer provides a new technology to charge electric vehicles (EVs) without physical contact. This system has to partially resolve the autonomy problem for EVs and buses. The majority of researchers were exposed to two categories of this technique: stationary wireless charging (SWC) and dynamic wireless charging (DWC) systems. Actually, the wireless recharge method is a recent solution that eliminates the problem of waiting time in recharge stations. However, the problem is always related to the vehicle status: if it is in motion and if it is in high‐speed running mode. In this context, this paper defines and examines the mathematical model of the DWC system and explains its function in relation to several parameters related to the vehicle situation. This study explores the mathematical model and identifies the best conditions for using the recharge method when the vehicle is in motion. The analysis study was elaborated using MATLAB/Simulink software, and the obtained results showed the variation of the state of charge, depending on the vehicle speed. [ABSTRACT FROM AUTHOR]

In dynamic wireless charging applications, segmented transmitter coils transfer power to a moving receiver coil. This article proposes a method in which the field strength in coupled transmitter coils automatically adjusts based on the position of the receiver. Specifically, a saturable inductor is applied to provide a high uncompensated inductive reactance in the uncoupled condition. By exploiting the reflected reactance as the system approaches the maximum coupled condition, the inductor saturates and the field strength in the coupled transmitter coils automatically increases. The field strength is at its peak when the transmitting and receiving coils reach their maximum coupling and sharply decreases when the receiver is decoupled from the transmitter. Consequently, the difference between the coupled and uncoupled currents in the transmitter coil is maximized, resulting in a near six-fold improvement in field containment performance compared to previously reported findings. This allows for system-level efficient power transfer and compliance with electromagnetic emission standards without complex shielding circuits and auxiliary active position detection approaches. We present the analysis, design criteria of the compensation network, and experimental validation for the proposed method. [ABSTRACT FROM AUTHOR]

Globally and regionally, there is an increasing impetus to electrify the road transport system. The diversity and complexity of the road transport system pose several challenges to electrification in sectors that have higher energy usage requirements. Electric road systems (ERS) have the potential for a balancing solution. An ERS is not only an engineering project, but it is also an innovation system that is complex and composed of multiple stakeholders, requiring an interdisciplinary means of aligning problems, relations, and solutions. This study looked to determine the political, economic, social, and technical (PEST) factors by actively engaging UK stakeholders through online in-depth and semi-structured discussions. The focus is on dynamic wireless power transfer (DWPT) due to its wider market reach and on the basis that a comprehensive review of the literature indicated that the current focus is on the technical challenges and hence there is a gap in the knowledge around application requirements, which is necessary if society is to achieve its goals of electrification and GHG reduction. Qualitative analysis was undertaken to identify factors that are critical to the success of a DWPT system. The outcome of this study is knowledge of the factors that determine the function and market acceptance of DWPT. These factors can be grouped into six categories: vehicle, journey, infrastructure, economic, traffic and behaviour. These factors, the associated probability distributions attributable to these factors and the relations between them (logic functions), will form the basis for decision making when implementing DWPT as part of the wider UK electric vehicle charging infrastructure and hence support the ambition to electrify all road transport. The results will make a significant contribution to the emerging knowledge base on ERS and specifically DWPT.