Jeff C. White

Bio: Jeff C. White is an academic researcher from Denso. The author has contributed to research in topics: Electromagnetic coil & Wireless power transfer. The author has an hindex of 4, co-authored 8 publications receiving 362 citations. Previous affiliations of Jeff C. White include University of Michigan.

A New Integration Method for an Electric Vehicle Wireless Charging System Using LCC Compensation Topology: Analysis and Design

Abstract: There is a need for charging electric vehicles (EVs) wirelessly since it provides a more convenient, reliable, and safer charging option for EV customers. A wireless charging system using a double-sided LCC compensation topology is proven to be highly efficient; however, the large volume induced by the compensation coils is a drawback. In order to make the system more compact, this paper proposes a new method to integrate the compensated coil into the main coil structure. With the proposed method, not only is the system more compact, but also the extra coupling effects resulting from the integration are either eliminated or minimized to a negligible level. Three-dimensional finite-element analysis tool ANSYS MAXWELL is employed to optimize the integrated coils, and detailed design procedures on improving system efficiency are also given in this paper. The wireless charging system with the proposed integration method is able to transfer 3.0 kW with 95.5% efficiency (overall dc to dc) at an air gap of 150 mm.

Loosely Coupled Transformer Structure and Interoperability Study for EV Wireless Charging Systems

Abstract: As the wireless power transfer (WPT) technology has been proved to be a convenient and reliable charging method to plug-in hybrid electric vehicles and electric vehicles, the loosely coupled transformer structure and size are the primary and fundamental concern to design an efficient WPT system. In this paper, a double D (DD) coil and a unipolar coil are selected to conduct the study. We focus on the coil structure design to achieve the maximum coupling coefficient as well as efficiency with two situations: 1) with no misalignment, and 2) with a 75-mm door-to-door and 100-mm front-to-back misalignment at which the maximum operating capability can still be achieved. A coil size optimization process is proposed for both the DD coil and the unipolar coil configurations. The relationship between the size of the secondary (receiving) coil, which determines the weight of the pad on the vehicle, and achievable maximum efficiency is studied for both coil topologies. The interoperability between the two coil topologies is studied. The proposed transformer structures with aluminum shielding meet human exposure regulations of the International Commission on Non-Ionizing Radiation Protection guidelines as a foundation. Finally, experiments validated the analyses.

Loosely Coupled Transformer Coil Design to Minimize EMF Radiation in Concerned Areas

Abstract: Wireless power transfer (WPT) technology as a convenient and reliable charging method, its electromagnetic field (EMF) radiation, and its compliance with human electromagnetic exposure limits have recently been studied. Different from the current research, which validates the EMF radiation level of a predesigned WPT system, this paper presents the loosely coupled transformer design method to minimize the EMF in the concerned area. The energy storage in the primary and secondary coils is studied for all popular compensation topologies in recently reported research. The coil of the loosely coupled transformer is designed with the S-S compensation topology as an example. The EMF radiation level is optimized to below the International Commission on Non-Ionizing Radiation Protection guideline in the concerned area. A 3.3-kW WPT system for electric vehicle wireless charging with an LCC-LCC compensation topology is designed with detailed process and experiment results, verifying that the EMF radiation is controlled as designed. The numerical analysis of human exposure is performed with the finite-element method, and the results show compliance as expected.

Wireless charging system for charging vehicular battery

Abstract: A wireless charging system may be used to charge a battery in a vehicle via a receiving coil The wireless charging system may include a coil charge device, a linear track, a linear motor, and a charge control module The coil charge device includes a carriage and a transmitting coil positioned on the carriage The linear track extends across a designated path The coil charge device is positioned on and moveable along the linear track The linear motor is operable to move the coil charge device along the linear track The charge control module controls a position of the coil charge device along the designated path via the linear motor

Optimized compensation coils for wireless power transfer system

Abstract: A wireless power transfer system for charging a battery located in a vehicle includes a primary side network and a secondary side network. The primary side network includes a transmitting coil and a primary side compensation network. The primary side compensation network includes a primary compensation coil. The secondary side network includes a receiving coil and a secondary side compensation network. The secondary compensation network includes a secondary compensation coil. The primary compensation coil and the secondary compensation network has one of an unipolar coil design and a bipolar coil design, and the transmitting coil and the receiving coil has the other one of the unipolar coil design and the bipolar coil design.

Wireless Power Transfer—An Overview

Abstract: Due to limitations of low power density, high cost, heavy weight, etc., the development and application of battery-powered devices are facing with unprecedented technical challenges. As a novel pattern of energization, the wireless power transfer (WPT) offers a band new way to the energy acquisition for electric-driven devices, thus alleviating the over-dependence on the battery. This paper presents an overview of WPT techniques with emphasis on working mechanisms, technical challenges, metamaterials, and classical applications. Focusing on WPT systems, this paper elaborates on current major research topics and discusses about future development trends. This novel energy transmission mechanism shows significant meanings on the pervasive application of renewable energies in our daily life.

Wireless Power Transfer for Vehicular Applications: Overview and Challenges

Abstract: More than a century-old gasoline internal combustion engine is a major contributor to greenhouse gases. Electric vehicles (EVs) have the potential to achieve eco-friendly transportation. However, the major limitation in achieving this vision is the battery technology. It suffers from drawbacks such as high cost, rare material, low energy density, and large weight. The problems related to battery technology can be addressed by dynamically charging the EV while on the move. In-motion charging can reduce the battery storage requirement, which could significantly extend the driving range of an EV. This paper reviews recent advances in stationary and dynamic wireless charging of EVs. A comprehensive review of charging pad, power electronics configurations, compensation networks, controls, and standards is presented.

Implementation of the Constant Current and Constant Voltage Charge of Inductive Power Transfer Systems With the Double-Sided LCC Compensation Topology for Electric Vehicle Battery Charge Applications

Abstract: When compared to plugged-in chargers, inductive power transfer (IPT) methods for electric vehicle (EV) battery chargers have several benefits, such as greater convenience and higher safety. In an EV, the battery is an indispensable component, and lithium-ion batteries are identified as the most competitive candidate to be used in EVs due to their high power density, long cycle life, and better safety. In order to charge lithium-ion batteries, constant current/constant voltage (CC/CV) is often adopted for high-efficiency charging and sufficient protection. However, it is not easy to design an IPT battery charger that can charge the batteries with a CC/CV charge due to the wide range of load variations, because it requires a wide range of variation in its operating frequency, duty, or phase-shift. Furthermore, zero phase angle (ZPA) condition for the primary inverter cannot be achieved over the entire charge process without the help of additional switches and related driver circuits to transform the topology. This paper proposes a design method that makes it possible to implement the CC/CV mode charge with minimum frequency variation during the entire charge process by using the load-independent characteristics of an IPT system under the ZPA condition without any additional switches. A theoretical analysis is presented to provide the appropriate procedure to design the double-sided LCC compensation tank which can achieve both CC and CV mode charge under ZPA condition at two different resonant frequencies. As a consequence, the proposed method is advantageous in that the efficiency of compensation tank is very high due to achieving the perfect resonant operation during the entire charge process. A 6.6-kW prototype charger has been implemented to demonstrate the feasibility and validity of the proposed method. A maximum efficiency of 96.1% has been achieved with a 200-mm airgap at 6.6 kW during the CC mode charge.

Maximum Efficiency Tracking for Wireless Power Transfer Systems With Dynamic Coupling Coefficient Estimation

Abstract: Maximum efficiency tracking is an important issue for wireless power transfer (WPT) system. Traditional maximum efficiency tracking method normally focuses on load impedance matching with fixed coupling condition. However, WPT system is a loosely coupling system, the coupling coefficient varies due to relative movement between the primary and secondary sides. Unknown to this variation may result in failure of the tracking. In this paper, a novel maximum efficiency tracking method is proposed with integrated dynamic coupling coefficient estimation. This method can take almost all requirements for maximum efficiency tracking into account including adaption for coupling coefficient and load variation, and output controllability. The tracking method is easy to implement because no additional circuitry or measurement is required. Experimental results have verified the correctness of the proposed coupling coefficient estimation method. And the maximum efficiency tracking results show the system can achieve a good performance against coupling coefficient and load variation with the proposed tracking method.