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Inductive power transfer (IPT) technology is a promising solution for charging the electric vehicles (EVs) by enabling an EV to charge its energy storage system (battery) without any connecting wires through magnetic coupling. This paper proposes a new receiver design named Hollow Solenoid receiver that is compatible with the standard double-D transmitter defined by the SAE J2954 standard. A deep design analysis for the proposed Hollow Solenoid receiver is presented to define the optimum design parameters for coil (inductances, number of turns, dimensions, wires, etc.) and ferrite core (dimensions, number, arrangement, etc.). Several WPT3 (11.1kVA) solenoid receiver (SR) designs were presented and analyzed based on efficiency, weight, size, volume, and cost. The performance of the proposed SR was compared with the global Double-D receiver (DDR) presented by the SAE J2954 standard under different lateral and rotational alignment and loading conditions considering coupling factor, transmission power and efficiency, and stray electromagnetic fields (EMFs). The entire IPT system including coils, compensation network, power converters, controls, and battery load was modeled and analyzed for both SR and DDR coils. The results reveal that the proposed SR is compatible with the global DD transmitter at different alignment and loading conditions and is able to transmit the desired power (11 kW) at an efficiency > 85%. Hollow SR design shows the highest efficiency and lowest size, weight, and cost compared to DDR and other designs. [ABSTRACT FROM AUTHOR]

Inductive power transfer (IPT) technology offers a promising solution for electric vehicle (EV) charging. It permits an EV to charge its energy storage system without any physical connections using magnetic coupling between inductive coils. EV inductive charging is an exemplary option due to the related merits such as: automatic operation, safety in harsh climatic conditions, interoperability, and flexibility. There are three visions to realize wireless EV charging: (i) static, in which charging occurs while EV is in long-term parking; (ii) dynamic (in-motion), which happens when EV is moving at high speed; and (iii) quasi-dynamic, which can occur when EV is at transient stops or driving at low speed. This paper introduces an extensive review for IPT systems in dynamic EV charging. It offers the state-of-the-art of transmitter design, including magnetic structure and supply arrangement. It explores and summarizes various types of compensation networks, power converters, and control techniques. In addition, the paper introduces the state-of-the-art of research and development activities that have been conducted for dynamic EV inductive charging systems, including challenges associated with the technology and opportunities to tackle these challenges. This study offers an exclusive reference to researchers and engineers who are interested in learning about the technology and highlights open questions to be addressed. [ABSTRACT FROM AUTHOR]

Inductive power transfer technology has gained massive attention for electric vehicle charging due to the associated reliability, convenience, and safety. Nevertheless, the loose coupling between the transmitter and receiver generates intensive electromagnetic fields (EMFs) around the system, which may influence living objects’ safety if the typical limits are exceeded. Moreover, these fields induce voltages in the vehicle body, which may lead to touch current passing through the human body when it gets in contact with two metal parts or one part and the ground. Following the international standards and recommendations, this paper presents comprehensive test guidelines for the near-EMFs and touch currents from a commercial 25-kW wireless charger from Momentum Dynamics, which was installed in an electric shuttle operating at the National Renewable Energy Laboratory (NREL) campus. The paper investigates the measuring devices, test setup, test points, and standard limits. The impact of the misalignments on the measurements is considered during testing. EMFs are measured in areas around and inside the shuttle and near the power supply and compared with the reference levels defined by the international standards, including ICNIRP 2010, IEEE C95.1, and ACGIH TLV 2017. Touch currents are evaluated among different metal parts and ground in comparison with the standard limits. The results show that both EMFs and touch currents comply with the standard limits. Moreover, thermal inspection for the system after installation was provided. Finally, five days of operation data for the wireless charger are collected and presented. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive solution that allows a wirelessly connected electric vehicle (EV) to be autonomously charged and discharged, during long-term parking and/or transient stops. A bilayer power flow controller for bidirectional wireless power transfer system (BWPTS) in EVs applications is proposed. The proposed controller can manage the power flow between the EV and surrounding infrastructures, such as utility grid, home micro-grid, building micro-grid, road, or another vehicle. It consists of two control layers; the first is responsible for communicating with the surrounding infrastructures and gathering information from the vehicle operator, charging station, utility grid, and battery management system. These data are analyzed to generate the reference power signal with information about the mode of operation (charge, discharge, or abstain) and rate. The second layer receives the reference signal and predicts the control parameters for the resonant converters (on both the vehicle and grid sides) to track the desired power. The proposed algorithm is adaptively estimating the mutual inductance to consider the misalignments in the system, based on a new simple real-time mutual estimation algorithm using a single voltage measurement from the vehicle side. The second control layer is designed based on an accurate analytical model for the BWPTS's power flow. For verification purposes, a prototype for BWPTS was built and driven by the proposed controller, which was implemented using a field-programmable gate array integrated circuit. Also, a vehicle-level simulation was performed to validate the operation of the proposed controller in quasi-dynamic wireless charging at traffic signals. The proposed controller shows fast and stable response during both the transient and steady-state operation in comparison with the conventional proportional-integral controller. [ABSTRACT FROM AUTHOR]

Inductive power transfer (IPT) technology has been approved to be convenient and reliable interface for charging and discharging the electric vehicles (EVs). Precise model for such system can help designers and researchers to anticipate, optimize, and evaluate its behavior amid the development. Thus, this paper presents a physics-based co-simulation platform for the bidirectional IPT system (BIPTS) in EVs’ applications. The platform is established through the coupling between finite element and circuit analysis. The power electronic converters and controllers are developed in Simulink; and the power pads are modeled in Magnet environment. The two parts are lined together through the compatible Simulink plug-in tool. In addition, a state-space dynamic mathematical model for the same BIPTS is derived and implemented in MATLAB environment. A 1.2 kW BIPTS is analyzed under different dynamics by both models and the results are compared. The effect of the nonlinearities and the magnetic material characteristics on the BIPTS's performance is assessed, in terms of errors and harmonics analysis. The analysis considered both the full and light loading operating conditions in the system. Finally, a small-scale prototype for a BIPTS is built, tested, and compared with the co-simulation results for verification purposes. The proposed co-simulation could provide accurate prediction for the system's dynamics, during both charging and discharging operation. The scheme is generic and can be easily expanded to different pad structures, compensation networks, and converter topologies. [ABSTRACT FROM PUBLISHER]

Electric vehicle (EV) can act as an energy consuming device or a distributed energy resource in the concepts known as vehicle-to-grid (V2G) and grid-to-vehicle (G2V). The bidirectional wireless power interface is a successful choice for this application, since it provides automatic, reliable, and safe operation. Therefore, this paper presents modeling and assessment analysis for the steady-state performance of bidirectional inductive wireless power transfer system (BIWPTS) in EV implementations. The analysis is presented for the three main compensation configurations: LC-series, LC-parallel, and LCL-topology. Moreover, the steady-state equivalent circuit-based mathematical models for all topologies are developed. These models were used to precisely determine the system response during V2G and G2V operations based on Fourier series. The study presents evident criteria to pick among the different BIWPTS structures in the diverse applications. The proposed analyses were verified both in simulation and experiment. The results demonstrate the ability of the proposed models to provide accurate estimation for BIWPTS performance under various operating and control conditions. Also, the evaluation analysis shows that LCL-topology is more appropriate for the bidirectional operation due to the simple design and control requirements, and being less sensitive to the misalignment. [ABSTRACT FROM AUTHOR]

A flexible, automatic, reliable, and safe charging and discharging system for electric vehicles (EVs) and hybrid EVs is crucial in vehicle-to-grid (V2G) operation. The bidirectional inductive wireless power transfer system (BIWPTS) is an ideal solution in this situation. With authentic power-flow models for the BIWPTS in hand, designers and operators can predict, optimize, and analyze the interaction performance between the EV and the grid. Thus, this paper presents a harmonics-based theoretical power-flow model for BIWPTS for charging and discharging EVs in V2G applications. The proposed model provides accurate estimation for the active and reactive power flow during V2G and grid-to-vehicle modes. Moreover, the impact of the circuit losses and harmonics, due to the high-frequency power inverters, on the power-flow performance is investigated. This effect is stated mathematically by four novel power-flow criteria formulas. New conditions for achieving maximum active and reactive power, and unity and zero power-factor system operation, are also developed. The sensitivity of the circuit performance to the variation of its parameters has been studied. For validation purposes, a computer-based model and experimental platform of BIWPTS for EV applications are developed and tested. The comparison between the theoretical, simulation, and experimental results verified the proposed models and analysis. [ABSTRACT FROM PUBLISHER]

This paper presents a clear methodology for achieving the optimum design of LCL bidirectional inductive wireless power transfer system (BIWPTS) for electric vehicle applications. The proposed strategy depends on electromagnetic field computations joined with analytical models. A 3-D finite-element model for 8-kW polarized double-D power pad was modeled, optimized, and built. Moreover, the choice of the power factor correction and the impedance matching elements was investigated. Following the proposed design considerations, a BIWPTS model was developed in MATLAB Simulink and its outcomes were compared with the theoretical model results. In addition, a small scale prototype was assembled using the same design with reduced dc voltage levels. The models were tested during charging and discharging operation, and good correlation was seen between every one of them. [ABSTRACT FROM AUTHOR]

This paper proposes a simple single-phase new pulse-width modulated seven-level inverter architecture for photovoltaic (PV) systems supporting home-grid with electric vehicle (EV) charging port. The proposed inverter includes a reduced number of power components and passive elements size, while showing less output-voltage total harmonic distortion (THD), and unity power factor operation. In addition, the proposed inverter requires simple control and switching strategies compared to recently published topologies. A comparative study was performed to compare the proposed inverter structure with the recent inverter topologies based on the number of components in the inverter circuit, number of components per output-voltage level, average number of active switches, THD, and operating efficiency as effective parameters for inverter performance evaluation. For design and validation purposes, numerical and analytical models for a grid-tied solar PV system driven by the proposed seven-level inverter were developed in MATLAB/Simulink environment. The inverter performance was evaluated considering grid-integration and stand-alone home with level-2 AC EV charger (3–6 kW). Compared with recently published topologies, the proposed inverter utilizes a reduced number of power components (7 switches) for seven-level terminal voltage synthesis. An experimental prototype for proposed inverter with the associated controller was built and tested for a stand-alone and grid-integrated system. Due to the lower number of ON-switches, the inverter operating efficiency was enhanced to 92.86% with load current THD of 3.43% that follows the IEEE standards for DER applications. [ABSTRACT FROM AUTHOR]