Emerging Works on Wireless Inductive Power Transfer: AUV Charging from Constant Current Distribution and Analysis of Controls in EV Dynamic Charging

Wireless power transfer through inductive coupling, termed as inductive power transfer (IPT), is one of the important technologies in power electronics that enable transfer of power between entities without physical connections. While it has seen significant growth in the areas such as electric vehicle charging, phone charging and biomedical implants, its emerging applications include charging of autonomous underwater vehicles (AUVs) and dynamic charging of electric vehicles from the roadway. This dissertation addresses a few key challenges in these areas of IPT applications, paving the way for future developments. For the WPT for AUV, the recently developing sea-bed installed marine systems are targeted, which typically gets power from on-shore sources through constant dc low-current distribution. As the present underwater IPT topologies are not suitable for such applications, this dissertation proposes underwater IPT topologies to interface directly with such constant current distribution and provide a constant voltage output supply to the on-board systems inside the AUVs. The considerations for seawater losses and the small-signal models for control purposes are also addressed. Analysis and experimental results are provided for validations of the analytical designs and models. In the area of electric vehicle dynamic wireless power transfer (EV DWPT), the comparison of control performances of different coupler, compensation topologies and control implementations are addressed. The effect of communication latency on control bandwidth are also addressed. The outcomes are presented through analysis and simulations, and based on that future research recommendations are made to pave way for future commercial developments of well regulated and interoperable EV DWPT systems

Challenges of Inductive Electric Vehicle Charging Systems in both Stationary and Dynamic Modes

Inductive power transfer as an emerging technology has become applicable in wide power ranges including Electric Vehicle, Electric Aircraft, wheelchair, cellphone, scooter and so on. Among them, inductive Electric Vehicle (EV) charging has gained great interest in the last decade due to many merits namely contactless technology, more convenience, full automotive charging process. However, inductive EV charging systems could bring about so many issues and concerns which are addressed in this dissertation. One of the critical challenges addressed in this dissertation is a virtual inertia based IPT controller to prevent the undesirable dynamics imposed by the EVs increasing number in the grid. Another adverse issue solved in this dissertation is detecting any metal object intrusions into the charging zone to the Inductive Power Transfer (IPT) systems before leading to heat generation on the metal or risk of fire. Moreover, in this dissertation, a new self-controlled multi-power level IPT controller is developed that enables EV charging level regulation in a wide range of power; suitable for different applications from golf-cart charging system (light duty EV) to truck (heavy duty EV). The proposed controller has many merits including easy to be implemented, cons-effective, and the least complexities compared to conventional PWM methods. Additionally, in this dissertation, the online estimation of IPT parameters using primary measurement including coupling factor, battery current and battery voltage is introduced; the developed method can find immediate applications for the development of adaptive controllers for static and dynamic inductive charging systems. Finally, the last objective of this research is physics-based design optimization techniques for the magnetic structures of inductive EV charging systems for dynamic application (getting charged while in motion). New configuration of IPT transmitting couplers with objective of high-power density, low power loss, low cost and less electromagnetic emission are designed and developed in the lab

Inductive Wireless Power Transfer Charging for Electric vehicles - A Review

Considering a future scenario in which a driverless Electric Vehicle (EV) needs an automatic charging system without human intervention. In this regard, there is a requirement for a fully automatable, fast, safe, cost-effective, and reliable charging infrastructure that provides a profitable business model and fast adoption in the electrified transportation systems. These qualities can be comprehended through wireless charging systems. Wireless Power Transfer (WPT) is a futuristic technology with the advantage of flexibility, convenience, safety, and the capability of becoming fully automated. In WPT methods resonant inductive wireless charging has to gain more attention compared to other wireless power transfer methods due to high efficiency and easy maintenance. This literature presents a review of the status of Resonant Inductive Wireless Power Transfer Charging technology also highlighting the present status and its future of the wireless EV market. First, the paper delivers a brief history throw lights on wireless charging methods, highlighting the pros and cons. Then, the paper aids a comparative review of different type’s inductive pads, rails, and compensations technologies done so far. The static and dynamic charging techniques and their characteristics are also illustrated. The role and importance of power electronics and converter types used in various applications are discussed. The batteries and their management systems as well as various problems involved in WPT are also addressed. Different trades like cyber security economic effects, health and safety, foreign object detection, and the effect and impact on the distribution grid are explored. Prospects and challenges involved in wireless charging systems are also highlighting in this work. We believe that this work could help further the research and development of WPT systems.publishedVersio

Design Optimization of Inductive Power Transfer Systems for Contactless Electric Vehicle Charging Applications

Contactless Electric Vehicle (EV) charging based on magnetic resonant induction is an emerging technology that can revolutionize the future of the EV industry and transportation systems by enabling an automated and convenient charging process. However, in order to make this technology an acceptable alternative for conventional plug-in charging systems it needs to be optimized for different design measures. Specifically, the efficiency of an inductive EV charging system is of a great importance and should be comparable to the efficiency of conventional plug-in EV chargers. The aim of this study is to develop solutions that contribute to the design enhancement of inductive EV charging systems. Specifically, generalized physics-based design optimization methods that address the trade-off problem between several key objectives including efficiency, power density, misalignment tolerance, and cost efficiency considering critical constraints are developed. Using the developed design methodology, a 3.7kW inductive charging system with square magnetic structures is investigated as a case study and a prototype is built to validate the optimization results. The developed prototype achieves 93.65% efficiency (DC-to-DC) and a power density of 1.65kW/dm3. Also, self-tuning power transfer control methods with resonance frequency tracking capability and bidirectional power transfer control are presented. The proposed control methods enhance the efficiency of power converters and reduce the Electromagnetic Interference (EMI) by enabling soft-switching operations. Several simplified digital controllers are developed and experimentally implemented. The controllers are implemented without the use of DSP/FPGA solutions. Experimental tests show that of the developed simplified controllers can effectively regulate the power transfer around the desired value. Moreover, the experiments show that compared to conventional converters, the developed converters can achieve 4% higher efficiency at low power levels. Moreover, enhanced matrix converter topologies that can achieve bidirectional power transfer and high efficiency with a reduced number of switching elements are introduced. The self-tuning controllers are utilized to design and develop control schemes for bidirectional power transfer regulation. The simulation analyses and experimental results show that the developed matrix converters can effectively establish bidirectional power transfer at the desired power levels with soft-switching operations and resonance frequency tracking capability. Specifically, a direct three-phase AC-AC matrix converter with a reduced number of switches (only seven) is developed and built. It is shown that the developed converters can achieve efficiencies as high as 98.54% at high power levels and outperform conventional two-stage converters

Modeling of Magnetic Resonance Wireless Electric Vehicle Charging

Due to the fast-growing market for an electric vehicle, it is necessary that the drawbacks involved in electric vehicle technology should be overcome, therefore introducing a wireless charging technique which is more convenient as battery cost, recharge time and weight has been removed. Different wireless charging techniques for electric vehicles are discussed. This research work investigates the feasibility of wireless power transfer for Electric Vehicles by electromagnetic resonance coupling. Wireless power transfer (WPT) for Electric Vehicles by magnetic resonance coupling is of high priority due to its efficiency, high power transmission, and more considerable charging distance. Simulation results show the energy transfer efficiency between two magnetically coupled resonating coils. However, results show the effects of parameters such as an inductor, capacitor, load and coupling coefficient on efficiency. Additionally, implementation of a closed loop circuit using a three-level cascaded PI controller for the dynamic wireless electric vehicle charging to eliminate the variation of voltage because of varied spacing existing between both coils as the vehicle is in motion and thereby delivering a constant voltage and constant current to the load is carried out. Simulation results and comparison with a single level PI controller indicate the effectiveness of the control method. A fuzzy logic and neuro-fuzzy controller are implemented for the wireless electric vehicle transfer which is seen to be more robust than the PI controller as there is no undershoot in the output voltage. Furthermore, wireless power transfer with three - level cascaded PI controller with MPPT is designed. The proposed system consists of a solar PV array, boost DC/DC converter, inverter, transmitter coil, a receiver coil, rectifier, buck converter, and batteries. The design of the MPPT controller tracks the highest voltage and current from the PV array required to charge a battery in which the highest power point voltage is 61.5 V. The stability analysis for the closed-loop system has been done and the system is asymptotically stable

Development of a Resonant High Power Charging Station for Fleet Vehicles

C onventional vehicles chargers are based on plugging the car battery using wire to the electricity grid through some conversion levels. In general, this system is an interface between the AC grid and the battery which requires DC voltages. The focus of this research is on wireless power charging technology. The wireless configuration benefits the system by providing electric isolation between transmitter and receiver side, and by making the charging process more convenient for the users. One major drawback of the wireless charging systems in compare to the conventional system is the lower efficiency of these systems. The resonant high power charging configuration of this study is designed to tackle this problem by enabling soft switching to minimize the switching loss. In this research a resonant LLC configuration is used for the EV charging application. The configuration and the step by step design of the resonant circuit is illustrated and analyzed. Also, other different topologies of the wireless charging systems have been introduced and compared with the proposed topology. The converter is modeled and simulated for different modes of operation. The optimal frequency selection which is dictated by the resonant circuit and magnetic design is obtained based on the mathematical model of the circuitry. The simulation results show that the designed converter improves the efficiency significantly using the resonant wireless charging configuration

Development of a Resonant High Power Charging Station for Fleet Vehicles

C onventional vehicles chargers are based on plugging the car battery using wire to the electricity grid through some conversion levels. In general, this system is an interface between the AC grid and the battery which requires DC voltages. The focus of this research is on wireless power charging technology. The wireless configuration benefits the system by providing electric isolation between transmitter and receiver side, and by making the charging process more convenient for the users. One major drawback of the wireless charging systems in compare to the conventional system is the lower efficiency of these systems. The resonant high power charging configuration of this study is designed to tackle this problem by enabling soft switching to minimize the switching loss. In this research a resonant LLC configuration is used for the EV charging application. The configuration and the step by step design of the resonant circuit is illustrated and analyzed. Also, other different topologies of the wireless charging systems have been introduced and compared with the proposed topology. The converter is modeled and simulated for different modes of operation. The optimal frequency selection which is dictated by the resonant circuit and magnetic design is obtained based on the mathematical model of the circuitry. The simulation results show that the designed converter improves the efficiency significantly using the resonant wireless charging configuration

Design and optimization of a three phase inductive power transfer system

193 p.El concepto de transporte sostenible dentro de las ciudades debe ser reconsiderado para poder así tener áreas urbanas más saludables. Es un hecho bien conocido que en las grandes ciudades sufren de grandes problemas de contaminación. Principalmente, debido los vehículos de combustión interna, con grandes emisiones de CO2. Estos representan más del 50% de los vehículos utilizados diariamente. Es por ello que el transporte público debe ser estimulado. Particularmente hablando, el transporte ferroviario es muy atractivo, ya que no se producen emisiones directas.Los sistemas de transporte ferroviario, como los tranvías y los metros, son muy ventajosos en términos de eficiencia, precio del usuario, seguridad y comodidad. Sin embargo, en comparación con un vehículo de combustión interna, los costos iniciales y de mantenimiento son muy altos. El alto costo inicial se debe principalmente al alto precio de las baterías. Por otro lado, el mantenimiento se ve enormemente afectado por la corrosión y la exposición ambiental que sufre parte del sistema de alimentación, el pantógrafo y las catenarias, siendo estos los componentes más críticos. Además, en las grandes ciudades, con muchas líneas de tranvía, las catenarias tienen un gran impacto visual. Para solucionar estos problemas, una de las opciones más prometedoras es dotar al vehículo ferroviario de un sistema de transferencia inductiva (IPT). De esta forma, la catenaria podría eliminarse y la carga se realizará de forma inalámbrica con las bobinas del transmisor enterradas en el suelo.Entre los diferentes sistemas posibles de IPT, este trabajo se centra en los sistemas de transferencia de energía inductiva dinámica (DIPT), es decir, cuando se está cargando mientras el vehículo se está moviendo. En concreto, esta tesis se adentra en el diseño de bobinas tipo meandro. El objetivo de este trabajo es proponer un método para diseñar sistemas de carga inductiva trifásicos. Para ello, los principios fundamentales de funcionamiento del sistema IPT se introducen en la primera parte de esta tesis. Las ecuaciones se presentan y se calcula el límite de división de polos. Validándolos en un prototipo de 3.3kW.Posteriormente, se describen los principios de trabajo de la bobina del tipo meandro. Se muestran las ecuaciones que modelan estas bobinas y se resalta la posibilidad de lograr un acoplamiento constante con múltiples fases. Además, con las modificaciones presentadas, el sistema multifásico se puede modelar mediante un sistema monofásico equivalente. Gracias a esto, el límite de división de polos se puede calcular fácilmente. Utilizando este límite, se describe un procedimiento de diseño y se valida experimentalmente en un prototipo de 50W. Este prototipo muestra el potencial de este tipo de bobinas, logrando una transmisión de potencia constante con una eficiencia del 70%.Sobre la base de este procedimiento de diseño, se propone una metodología de optimización para mejorar el tamaño, el peso y el costo del DIPT. Se resaltan los compromisos existentes entre estos indicadores. Finalmente, esta optimización se aplica para un sistema de 9kWy se valida en un banco de prueba real, con una eficiencia medida del 90%, para cualquier posición y potencia de salida con una separación de bobina de 100m