Dynamic Wireless Power Transfer Research Articles

A Comprehensive Review on Control Technique and Socio-Economic Analysis for Sustainable Dynamic Wireless Charging Applications

Dynamic wireless power transfer (DWPT) has garnered significant attention as a promising technology for electric vehicle (EV) charging, eliminating the need for physical connections between EVs and charging stations. However, the improvement in power transfer efficiency is a major challenge among the research community. Different techniques are investigated in the literature to maximize power transfer efficiency. The investigations include the power electronic circuit, magnetic coupler design, compensating capacitance and control technique. Also, the investigations are carried out based on the type of wireless charging system, which is either a static or dynamic scenario. There are a good number of review articles available on the power electronic circuit and compensator design aspects of WPT. However, studies on the controller design and tracking maximum efficiency are some of the important areas that need to be reviewed. This paper provides a comprehensive review of bibliometric analysis on the DWPT technology, design procedure, and control technique to increase the power transfer and socio-economic acceptance analysis. The manuscript also provides information on the challenges and future direction of research in the field of DWPT technology.

Maintain Power Transmission and Efficiency Tracking Using Variable Capacitors for Dynamic WPT Systems

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.

Improved compensation networks for dynamic wireless power transfer in a multi-inductor track

PurposeThe purpose of the study is to design the compensation network of a dynamic wireless power transfer system, considering the movement of the receiving coil along an electrified track with a large number of inductors buried on the road.Design/methodology/approachA finite element model has been developed to calculate the self-inductances of transmitting and receiving coils as well as the mutual inductances between the receiving coil and the transmitting ones in the nearby and for various relative positions. The calculated lumped parameters, self-inductances and mutual inductances depending on the relative positions between the coils, have been considered to design the compensation network of the active coils, which is composed of three capacitive or inductive reactances connected in the T form. The optimal values of the six reactances, three for the transmitting coils and three for the receiving one, have been calculated by resorting to the Genetic Algorithm NSGA-II.FindingsIn this paper, the results obtained by means of the optimizations have broadly discussed. The optimal values of the reactances of the compensation networks show a clear trend in the receiving part of the circuit. On the other hand, the problem seems very sensitive to the values of the reactances in the transmitting circuit.Originality/valueDynamic wireless power transfer system is one of the newest ways of recharging electric vehicles. Hence, the design of compensation networks for this kind of systems is a new topic, and there is the need to investigate possible solutions to obtain a good performance of the recharging system.

A Noncommunication Mutual Inductance Estimation Method for Multiple Transmitters SS-Compensated Dynamic Wireless Power Transfer With Low Calculation Effort

A Noncommunication Mutual Inductance Estimation Method for Multiple Transmitters SS-Compensated Dynamic Wireless Power Transfer With Low Calculation Effort

Fast Start-Up Control of Both-Side Current Without Overshoot Focusing on Rectification Timing for Dynamic Wireless Power Transfer Systems

The paper proposes a method to improve the tran- sient characteristics of current overshoot and oscillation at the start of power transmission for a dynamic wireless power transfer system. The system is important to reduce the settling time as short as possible without current overshoots for a stable power supply. However, conventional methods to suppress current overshoot have a slow response on the secondary side. This paper proposes the superposition of primary and secondary responses. The proposed method controls the secondary voltage by comparing the steady-state current with the current value on the secondary side. The method can effectively suppress the oscillations in the transient response by applying the secondary voltage at the appropriate timing. This paper also studied the ro- bustness of constraints based on model analysis and experimental verification. In the experiments, the proposed method reduces the current overshoot and the settling time of the secondary current, and maximizes the receiving energy.

Dynamic Resonant-Inductive Wireless Power Transfer System for Automated Guided Vehicles with Reduced Number of Position Sensors

This paper deals with the position detection of automated guided vehicles (AGVs) in dynamic resonant-inductive wireless power transfer (WPT) systems. A position detection is necessary to activate the correct transmitting coil. One of the simplest and most effective approaches for a position detection method is to use optical or magnetic position sensors for each coil. However, due to needing a high number of sensors, this technique is relatively expensive. Therefore, an AGV position detection technique based on a reduced number of optical or magnetic sensors (by a factor of two) is proposed. The proposed detection technique was verified experimentally by using a scaled-down prototype of the dynamic WPT system. The proposed approach can be easily implemented by uploading a specific program code to a microcontroller. The microcontroller with the code developed by us was used for processing data from AGV position detection sensors, activating a suitable transmitting coil and controlling an inverter of the dynamic WPT system. As shown by the experiments, due to the proposed approach for the position detection of AGVs and activation of transmitting coils, the number of the position detection sensors is reduced by a factor of two, leading to reductions in the overall cost and level of complexity of the dynamic WPT system without degrading its performance.

Discharging driven energy sharing protocol for V2V communication in vehicular energy networks

With the growing concern over range anxiety among electric vehicle (EV) owners due to limited battery capacity and sparse charging infrastructure, EV-to-EV (V2V) energy sharing emerges as a crucial solution to extend driving range. Leveraging the vehicular energy network (VEN) enabled by dynamic wireless power transfer (DWPT) technology, energy sharing among EVs in motion becomes feasible. However, the effective establishment of communication and identification of suitable V2V energy sharing pairs pose significant challenges, particularly for EVs with discharging demands. To address this challenge, we propose a new discharging driven energy sharing protocol based on vehicular ad-hoc networks (VANETs). Firstly, we present a routing approach for transmitting discharging information through VANETs, considering key factors such as distance, state of charge, number of neighbor vehicles, and vehicle speed. This routing scheme facilitates efficient relay node selection on road segments and intersections, ensuring optimal communication paths. Subsequently, we formulate a charging requester selection model to identify the most suitable requester for energy sharing. This model optimizes individual utility while accounting for the state of charge of the requesters, ensuring a comprehensive and inclusive approach to V2V energy sharing. Finally, we develop an acknowledgment message transmission scheme to ensure the completion of selection acknowledgment between discharging EVs and charging EVs. This scheme includes provisions for recovery in case of forwarding link failures, ensuring robust communication in dynamic vehicular environments. Extensive simulations conducted using network simulator 2 (NS-2) demonstrate the superior performance of the proposed protocol in terms of packet delivery ratio, end-to-end delay, and overall V2V energy sharing efficiency.

Comparing costs and climate impacts of various electric vehicle charging systems across the United States

The seamless adoption of electric vehicles (EVs) in the United States necessitates the development of extensive and effective charging infrastructure. Various charging systems have been proposed, including Direct Current Fast Charging, Battery Swapping, and Dynamic Wireless Power Transfer. While many studies have evaluated the charging costs and greenhouse gas (GHG) intensity of EVs, a comprehensive analysis comparing these systems and their implications across vehicle categories remains unexplored. This study compares the total cost of ownership (TCO) and GHG-intensity of EVs using these charging systems. Based on nationwide infrastructure deployment simulations, the change to TCO from adopting EVs varies by scenario, vehicle category, and location, with local fuel prices, electricity prices, and traffic volumes dramatically impacting results. Further, EV GHG-intensity depends on local electricity mixes and infrastructure utilizations. This research highlights the responsiveness of EV benefits resulting from technology advancements, deployment decisions, and policymaking.

Resonant coil matrix shielding for dynamic WPT systems

In this article, a magnetic shield for automotive Wireless Power Transfer (WPT) systems is proposed. Its innovative feature consists in the positioning of the shield, that is part of the Ground Assembly (GA) of the WPT system. Passive coils, assembled in an array-like structure to build the shields properly located near the transmitting coils are investigated. Currently, there are a variety of shielding methods, each of them with its peculiar feature. The proposed method is simple and does not increase the transmitting and the receiving coil sizes, a constraint that is often critical from a practical and an economical point of view. The main characteristic of the proposed shielding method is the location of the shielding coils on the same level as the GA. The results here presented are validated by Finite Element (FE) based simulations and are referred to an experimental prototype of wireless charging systems for electric vehicles operating at 85 kHz with a transmitted nominal power of 3.3 kW. The results show that the proposed shield reduces the leakage magnetic flux density in the system up to 37% with a marginal impact on the transmission efficiency, complying the SAE J2954 international standard.

Analysis of Leakage Current in Dynamic Wireless Power Transfer Systems Based on LCC-S Architecture

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.

Analyzing the Mechanical Response of a Calibrated Finite Element Model for Flexible Pavement with Embedded Dynamic Wireless Power Transfer Technology

Analyzing the Mechanical Response of a Calibrated Finite Element Model for Flexible Pavement with Embedded Dynamic Wireless Power Transfer Technology

Application of Real-Life On-Road Driving Data for Simulating the Electrification of Long-Haul Transport Trucks

The worldwide commitment to the electrification of road transport will require a broad overhaul of equipment and infrastructure. Heavy-duty trucks account for over one-third of on-road energy use. Electrified roadways (e-Hwys) are an emerging technology where electric vehicles receive electricity while driving via dynamic wireless power transfer (DWPT), which is becoming highly efficient, and can bypass the battery to directly serve the motor. A modeling study was undertaken to compare long-haul trucks on e-Hwys with conventional battery technology requiring off-road recharging to assess the most favorable pathway to electrification. Detailed data taken from on-road driving trips from five diesel transport trucks were obtained for this study. This on-road data provided the simulations with both real-life duty cycles as well as performance targets for electric trucks, enabling an assessment and comparison of their performance on e-Hwys or with fast recharging. Battery-only trucks were found to have lifetimes down to 60% original battery capacity (60% SOH) of up to 9 years with 1600 kWh packs, and were similar to conventional diesel truck performance. On e-Hwys smaller pack sizes in the 500 to 900 kWh capacity range were sufficient for the driving duty, and showed lifetimes upwards of 20 years, comparing favorably to the battery calendar life limit of about 26 years. For a 535 kWh battery pack, an e-Hwy DWPT level of 250 kW was sufficient for a 36 tonne truck to complete all the daily driving as defined by the diesel reference trucks, and reach a battery pack end of life point of 60% SOH.

Modular Power Electronics Approach for High-Power Dynamic Wireless Charging System

Dynamic wireless power transfer (DWPT) can provide energy to EVs in motion and extend the drive range. Upscaling the charging power to 200 kW (High Power DWPT) reduces the percentage of electrified roadway required, and the solution becomes cost-effective. To smooth the power at the battery and grid, a secondary regulation stage must be added. The DWPT system therefore relies on power electronics to interface with the coils and regulate the power flow. Designing this high power system using wide bandgap devices makes ensuring high efficiency, small size, and reliable operation very challenging, and significant engineering effort is required to build such complicated systems for large-scale installation and deployment. This paper describes a modular design approach for the power electronics to achieve the 200 kW wireless power transfer. As described, the SiC power electronics building block is designed, simulated, and characterized. The approach is validated in the DWPT system to build the inverter, the rectifier, and the DC/DC converter, which demonstrated high performance and reliable operation with 188 kW power.

Sustainability of Dynamic Wireless Power Transfer Roadway for In-Motion Electric Vehicle Charging

Numerous articles have been written regarding the potential affects that electric vehicle (EV) charging stations can have on power distribution systems. With the advent to adopt a dynamic wireless power transfer (DWPT) roadway charging infrastructure, there lies a potential for hazardous effects to occur. Therefore, this paper presents a novel methodology to analyze the sustainability and the potential effects that a DWPT roadway can have on electric power distribution grid. Historical traffic flow (HTF) data is converted using a Monte Carlo method to develop an EV traffic flow (EV-TF). Then, a full DWPT simulation of a 1-mile and 10-mile roadway is performed to determine the power fluctuations that can occur as different densities of EVs traverse the roadway. This method creates simulations using an IEEE 33-Bus power distribution system to evaluate if a DWPT roadway for in-motion EV charging causes voltage magnitudes to fluctuate beyond operational standards.

Optimization of magnetic coupling mechanism of dynamic wireless power transfer based on NSGA-II algorithm

Optimization of magnetic coupling mechanism is an important way to improve the performance of a dynamic wireless power transfer system. Inspired by the common radial magnetic core for circular coils, a new radial magnetic core for rectangular coils is adopt. Through simulation and experimental results comparison, which has higher coupling coefficient with the same core area. Combined with the magnetic circuit analysis, the magnetic flux leakage and conduction regions are divided into magnetic fluxes with different shapes, which magnetic resistances are calculated respectively. Based on the simulation results, parameter distributions of fluxes under different conditions are obtained. Therefore, the expressions of the coupling coefficient k of the adopt magnetic cores and coils and the design parameters of coils and cores are obtained. Taking the maximum k and the minimum rate of change of coupling coefficient with 100 mm displacement as the optimization objectives, a multi-objective optimization solution is carried out by using NSGA-II algorithm. The coil optimization scheme is obtained and verified by experiments. k and Δk are 0.442 and 6.8% respectively, and the errors are less than 5%. In the optimization process, there is no simulation model constructed. The optimization modeling combined of magnetic field segmentation method and parameter fitting has lower complexity and calculation time of optimization.

Design of a 60-kW EV Dynamic Wireless Power Transfer System With Dual Transmitters and Dual Receivers

Design of a 60-kW EV Dynamic Wireless Power Transfer System With Dual Transmitters and Dual Receivers

Stable dynamic wireless power transfer via a space-extendable high-order Non-Hermitian system

A prominent problem in wireless power transmission systems is the sensitivity of the mode frequency to changes in position. While a feedback system can address this issue, it also introduces complexity to the system, potentially giving rise to additional problems. Typically, more complex systems exhibit unique properties, and there are modes suitable for power transfer in high-order PT systems.In this paper, we propose a dynamic wireless power transmission system with hybrid coupling, utilizing odd coils only. This approach offers a feasible solution for dynamic wireless power transmission systems. We calculate the eigenvalues of the system and observe that the eigenvalue of a mode does not change as the load moves, remaining a pure real number. In our study, the system’s transmission efficiency can be maintained at a high and stable level at a fixed working frequency, even as the load position changes. This capability can be employed for stable dynamic charging.

Feedback Operating Frequency Control for Eliminating Dead Zone in Dynamic Wireless Power Transfer

Feedback Operating Frequency Control for Eliminating Dead Zone in Dynamic Wireless Power Transfer

Output Voltage Fluctuation Damping for Dynamic Wireless Power Transfer System of EVs Based on Sensorless Disturbance Rejection Control

Output Voltage Fluctuation Damping for Dynamic Wireless Power Transfer System of EVs Based on Sensorless Disturbance Rejection Control

Receiving Side Current-Based Lateral Misalignment Estimation and Automated Steering Control for Dynamic Wireless Power Transfer

Receiving Side Current-Based Lateral Misalignment Estimation and Automated Steering Control for Dynamic Wireless Power Transfer