Engineering Commons^™

Techniques To Overcome Energy Storage Limitations In Electric Vehicles, Matthew J. Hansen

All Graduate Theses and Dissertations, Fall 2023 to Present

Electric vehicles are becoming increasingly popular, battery limitations (cost, size, and weight) complicate electric vehicle adoption. While important research on battery development is ongoing, this dissertation discusses two main approaches to overcome those limitations within the existing battery technology paradigm. Those thrusts are: improving battery health through an optimal charging strategy and minimizing necessary battery size through dynamic wireless power transfer. In this dissertation, relevant literature is discussed, with opportunities for further development considered. Within the two thrusts, three objectives sharpen the focus of the research presented here. First, a planning tool is defined for a battery electric bus fleet. …

Systematic Design Of A 100 W 6.78 Mhz Wireless Charging Station Covering Multiple Devices And A Large Charging Area, Jie Li

Doctoral Dissertations

Wireless power transfer (WPT) promises to offer safe and convenient charging in consumer electronics applications. The application ranges from sub-watt medical implant device charging to watt-level household charging, further to the kilowatt electric vehicle (EV) and railway charging. At present, two industry standards are widely used to guide the WPT product design. The Qi standard describes an application that requires the receiver to be placed close to the transmitter, called "tightly coupled" WPT. The receiver coil typically has a similar size compared to the transmitter. And the operation frequency is in the kHz range. The Airfuel standard, on the other …

A High Frequency Wireless Power Transfer System For Electric Vehicle Charging Using Multi-Layer Non-Uniform Self-Resonant Coil, Ruiyang Qin

Doctoral Dissertations

Wireless EV (Electric Vehicle) charging is an emerging technology with rapid development in the past decade. Compared to wired EV chargers, wireless power transfer (WPT) enables safe and unobtrusive charging for EVs.

This work proposes high frequency wireless charging using a self-resonant (SR) coil at several megahertz. A multi-layer self-resonant coil structure is proposed, allowing high quality factor coils to be fabricated from layers of inexpensive copper foil and dielectric film. Additionally, the self-resonant coil utilizes its interlayer capacitance for resonance, eliminating the external compensation capacitor and shrinking the overall volume of passive component to increase the power density. Comparing …

Sizing Considerations For Ev Dynamic Wireless Charging Systems With Integrated Energy Storage, Donovin Lewis, Huangjie Gong, Gregory D. Erhardt, Rong Zeng, Omer Onar, Veda Prakash Galigekere, Burak Ozpineci, Dan Ionel

Power and Energy Institute of Kentucky Faculty Publications

Roadways with dynamic wireless charging systems (DWCS) enable charge-sustaining in-motion EV charging, which can reduce charging idle time while increasing range capabilities. Spatially distributed transmitter coils are controlled in response to traffic load that varies significantly minute to minute with high power levels, very short charging time, and low system utilization like wind turbine power. Traffic load estimation and localized analysis may guide effective sizing and topology adoption for feasible and scalable DWCS deployment. DWCS traffic load approximation is reviewed with measured Automated Traffic Recorder (ATR) data and statistical distributions being used to create a synthetic load analyzed using proposed …

8-Plate Multi-Resonant Coupling Using A Class-E2 Power Converter For Misalignments In Capacitive Wireless Power Transfer, Yashwanth Bezawada, Shirshak K. Dhali

Electrical & Computer Engineering Faculty Publications

Misalignment is a common issue in wireless power transfer systems. It shifts the resonant frequency away from the operating frequency that affects the power flow and efficiency from the charging station to the load. This work proposes a novel capacitive wireless power transfer (CPT) using an 8-plate multi-resonant capacitive coupling to minimize the effect of misalignments. A single-active switch class-E² power converter is utilized to achieve multi-resonance through the selection of different resonant inductors. Simulations show a widening of the resonant frequency band which offers better performance than a regular 4-plate capacitive coupling for misalignments. The hardware results of …

Roadway-Embedded Transmitters And Multi-Pad Receivers For High Power Dynamic Wireless Power Transfer, Benny J. Varghese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electric vehicles (EVs) offer considerable economic and environmental benefits to society. Despite the decreasing vehicle costs and increasing range of newer EVs, the problem of range anxiety still exists. Range anxiety, at its core, is an issue of charging speeds rather than a concern about the driving range. Dynamic wireless charging of EVs is seen as a potential solution to this issue of range anxiety. Further, wireless charging technology also helps the push towards level 5 autonomy and opens new opportunities for how an EV can be utilized.

Dynamic wireless power transfer (DWPT) systems typically require a high initial investment …

Microstrip Array Antenna For Wireless Power Transfer, Sahereh Sahandabadi

Electronic Theses and Dissertations

In this thesis, a triangular microstrip patch antenna is used to transfer wireless power at 2.4 GHz. First, the simple patch antenna is studied and its performance is investigated. Then, the new design is introduced to boost the efficiency and transmission coefficient of the simple patch antenna. Since the simple patch aimed to operate at 2.4GHz, its dimension is optimized to be 56mm with a reflection coefficient of -28.2 dB at the resonance frequency. An identical patch acting as a receiver is then placed in a 50mm distance to the main patch acting as a transmitter to enable us to …

Lyapunov Function-Based Stabilizing Control Scheme For Wireless Power Transfer Systems With Lcc Compensation Network, Abu Shahir Md Khalid Hasan

LSU Master's Theses

A stabilizing control scheme based on a Lyapunov function is proposed for wireless power transfer (or WPT) systems. A state-space model of the WPT system is developed and the Lyapunov function is formulated based on an energy equation of the system involving state variables. The internal resistance of a battery varies during charge and discharge. Therefore, if a WPT system is used to charge a battery, its output load will vary. Furthermore, the coupling coefficient between the transmitter (primary) and receiver (secondary) coils decreases when they are misaligned. Comparative case studies are conducted to verify the efficacy of the proposed …

Robust Secure Wireless Powered Miso Cognitive Mobile Edge Computing, Boyang Liu, Jiajia Song, Jin Wang, Haijan Sun, Qun Wang

Electrical and Computer Engineering Student Research

Wireless power transfer (WPT) and cognitive radio (CR) are two promising techniques in designing mobile-edge computing (MEC) systems. In this paper, we study a robust secure wireless powered multiple-input single-output (MISO) cognitive MEC system, which integrates several techniques: physical-layer security, WPT, CR, underlay spectrum sharing and MEC. Three optimization problems are formulated to minimize the total transmission power (TTP) of the primary transmitter (PT) and the secondary base station (SBS) under perfect channel state information (CSI) model, bounded CSI error model and the probabilistic CSI error model, respectively. The formulated problems are nonconvex and hard to solve. Three two-phase iterative …

An Emi Characterization And Modeling Study For Consumer Electronics And Integrated Circuits, Chunyu Wu

Doctoral Dissertations

“As internet-of-things (IoT) applications surge, wireless connectivity becomes an essential part of the network. Smart home, one of the most promising application scenarios of IoT, will improve our life quality enormously. However, electromagnetic interference (EMI) to the receiving antenna, either from another electronic product or from a module/an integrated circuit(IC) inside the same wireless device, will degrade the performance of wireless connectivity, thus influencing the user experience. Characterization and modeling of the EMI become increasingly important.

In the first part, an improved method to extract equivalent dipoles from magnitude- only electromagnetic-field data based on the genetic algorithm and back-and-forth iteration …

Analysis Of Antenna Designs For The Maximum Power Transmission, Lauryn P. Smith

Electronic Theses and Dissertations

Since Nikola Tesla discovered wireless power transmission, it has become a very interesting topic of study in the antennas and wireless propagation community. Various aspects and applications for wireless power transmission are studied today, a few of which are investigated in this work. First, various antenna geometries are analyzed for radiative near-field wireless power transfer in terms of electrical field strength. It is determined that the meander antenna is ideal for maximum power transfer in its radiative near-field region, contrary to its far-field behavior. Next, in the application of radio frequency identification, a directive, UHF RFID tag antenna is designed …

Energy Management Of Dynamic Wireless Power Transfer Systems For Electric Vehicle Applications, Ahmed N. Azad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wireless power transfer is a method of transferring electric power from a transmitter to a receiver without requiring any physical connection between the two. Dynamic Wireless Power Transfer (DWPT) entails having the transmitters buried under the roadway and the receiver unit being installed on the Electric Vehicle (EV). In this method, EVs are charged while driving over the transmitters as they receive bursts of electric energy at the time of significant alignment between transmitters and receivers. Compared to the stationary charging method which involves parking the EV for long hours for a full charge, the dynamic charging method (i.e., DWPT) …

Design Optimization Of Inductive Power Transfer Systems For Contactless Electric Vehicle Charging Applications, Masood Moghaddami

FIU Electronic Theses and Dissertations

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 …

Novel Strongly Coupled Magnetic Resonant Systems, Daerhan Liu

FIU Electronic Theses and Dissertations

Wireless power transfer (WPT) technologies have become important for our everyday life. The most commonly used near-field WPT method is inductive coupling, which suffers from low efficiency and small range. The Strongly Coupled Magnetic Resonance (SCMR) method was developed recently, and it can be used to wirelessly transfer power with higher efficiency over a longer distance than the inductive coupling method.

This dissertation develops new SCMR systems that have better performance compared to standard SCMR systems. Specifically, two new 3-D SCMR systems are designed to improve the angular misalignment sensitivity of WPT systems. Their power transfer efficiency for different angular …

A Frequency-Tuned Magnetic Resonance-Based Wireless Power Transfer System With Near-Constant Efficiency Up To 24 Cm Distance, Seyi̇t Ahmet Si̇s, Selçuk Kavut

Turkish Journal of Electrical Engineering and Computer Sciences

In magnetic resonance-based wireless power transfer systems, the main challenge arises from varying distances between coils during power transfer because distance variations ultimately reduce the power transfer efficiency. Frequency-tuned wireless power transfer systems provide an almost-constant output power to the load up to a critical coupling distance. However, the critical coupling distance and power transfer efficiency are dependent on coil size, source, and load resistances. The purpose of this paper is to discuss this dependency with an equivalent circuit model, determine a suitable coil size for given design specifications, and set up a frequency-tuned system that is based on tracking …

Load Characteristics Of Wireless Power Transfer System With Different Resonant Types And Resonator Numbers, Yiming Zhang, Zhengming Zhao, Kainan Chen, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Wireless Power Transfer (WPT) has been the research focus and applied in many fields. Normally power is transferred wirelessly to charge the battery, which requires specific load characteristics. The load characteristics are essential for the design and operation of the WPT system. This paper investigates the load characteristics of the WPT system with different resonant types and resonator numbers. It is found that in a WPT system with series or LCL resonance under a constant voltage source, the load characteristic is determined by the number of inductors. Even number of inductors results in a constant current characteristic and odd number …

A Study Of The Sensitivity Of Energy Conversion Efficiency To Load Variation In Class-E Resonant Power Inverter, Richard Samuel Jennings

Electrical & Computer Engineering Theses & Dissertations

In this thesis the sensitivity of energy conversion efficiency (ECE) and output power of a class-E resonant inverter under variable resistive and inductive load assignments is examined for wireless power transfer (WPT) applications. By performing simulation and mathematical analysis, it was found that the on-resistance of the switching device has minor effect on the design’s efficiency. Additional comparisons between the simulation and mathematical analysis show reasonable output power and ECE load variation performance for the design, but with unique load impedances where zero voltage switching (ZVS) and zero derivative switching (ZDS) are achieved. These comparisons also expose inaccurate mathematical assumptions. …

A Bidirectional Wireless Power Transfer System For An Electric Vehicle With A Relay Circuit, Chenyang Xia, Wei Wang, Yuling Liu, Kezhang Lin, Yanhe Wang, Xiaojie Wu

Turkish Journal of Electrical Engineering and Computer Sciences

In order to extend the transfer distance, enhance the tolerance for coil misalignment, and improve the capability of energy feedback and power transfer efficiency of conventional wireless power transfer (WPT) systems for electric vehicles, this paper presents a bidirectional WPT topology with a relay circuit. In the proposed topology, the primary and pickup circuits are implemented with virtually identical structures, which can operate in both magnetic field excitation and magnetic field receiving modes to facilitate bidirectional power flow between the primary side and the pickup side. A relay circuit is introduced to achieve high transfer efficiency under special conditions such …

Optimal And Miniaturized Strongly Coupled Magnetic Resonant Systems, Hao Hu

FIU Electronic Theses and Dissertations

Wireless power transfer (WPT) technologies for communication and recharging devices have recently attracted significant research attention. Conventional WPT systems based either on far-field or near-field coupling cannot provide simultaneously high efficiency and long transfer range. The Strongly Coupled Magnetic Resonance (SCMR) method was introduced recently, and it offers the possibility of transferring power with high efficiency over longer distances. Previous SCMR research has only focused on how to improve its efficiency and range through different methods. However, the study of optimal and miniaturized designs has been limited. In addition, no multiband and broadband SCMR WPT systems have been developed and …

Optimization Of Wireless Power Networks For Biomedical Applications, Kyle A. Thackston

Open Access Theses

Successful physiological integration of electronics will open the doors to new methods of treatment and diagnoses. One of the key challenges of this integration is designing devices as small as possible while still maintaining high functionality, such as bio-signal recording, processing, telemetry, and stimulation. Wireless power transfer (WPT) can help shrink a device’s footprint by removing the need for bulky batteries. While many modalities of WPT exist for biomedical applications, the optimal power transfer efficiency (PTE) is seldom achieved due to improper impedance matching. Existing methods for determining the optimal impedance matching conditions tend to be application specific and make …

Coupled Resonator Based Wireless Power Transfer For Bioelectronics, Henry Mei

Open Access Dissertations

Implantable and wearable bioelectronics provide the ability to monitor and modulate physiological processes. They represent a promising set of technologies that can provide new treatment for patients or new tools for scientific discovery, such as in long-term studies involving small animals. As these technologies advance, two trends are clear, miniaturization and increased sophistication i.e. multiple channels, wireless bi-directional communication, and responsiveness (closed-loop devices). One primary challenge in realizing miniaturized and sophisticated bioelectronics is powering. Integration and development of wireless power transfer (WPT) technology, however, can overcome this challenge.

In this dissertation, I propose the use of coupled resonator WPT for …

Isolated Wired And Wireless Battery Charger With Integrated Boost Converter For Phev And Ev Applications, Madhu Sudhan Chinthavali

Doctoral Dissertations

Vehicle charging and vehicle traction drive components can be integrated for multi-functional operations, as these functions are currently operating independently. While the vehicle is parked, the hardware that is available from the traction drive can be used for charging. The only exception to this would be the dynamic vehicle-charging concept on roadways. WPT can be viewed as a revolutionary step in PEV charging because it fits the paradigm of vehicle to infrastructure (V2I) wirelessly. WPT charging is convenient and flexible not only because it has no cables and connectors that are necessary, but due more to the fact that charging …

Midrange Magnetically-Coupled Resonant Circuit Wireless Power Transfer, Varun Nagoorkar

Electrical Engineering Theses

Recent years have seen numerous efforts to make wireless power transfer (WPT) feasible for application in diverse fields, from low-power domestic applications and medical applications to high-power industrial applications and electrical vehicles (EVs). As a result, it has been found that WPT by means of non-radiative magnetically-coupled resonant circuits is an optimum method for mid-range applications where the separation of source and receiver is in the range of 1-2m.This thesis investigates various aspects of the design of magnetically-coupled resonant circuits for non-radiative WPT. Firstly, a basic four-coil network for a mid-range (1-2m gap) WPT system with a single power source …

Design Of Analog Cmos Circuits For Batteryless Implantable Telemetry Systems, Kyle G. A. De Gannes

Electronic Thesis and Dissertation Repository

A wireless biomedical telemetry system is a device that collects biomedical signal measurements and transmits data through wireless RF communication. Testing medical treatments often involves experimentation on small laboratory animals, such as genetically modified mice and rats. Using batteries as a power source results in many practical issues, such as increased size of the implant and limited operating lifetime. Wireless power harvesting for implantable biomedical devices removes the need for batteries integrated into the implant. This will reduce device size and remove the need for surgical replacement due to battery depletion. Resonant inductive coupling achieves wireless power transfer in a …

Design And Optimization Of Efficient Wireless Power Transfer Links For Implantable Biotelemetry Systems, Shawon Senjuti

Electronic Thesis and Dissertation Repository

Wireless power transmission is a technique that converts energy from radio frequency (RF) electromagnetic (EM) waves into DC voltage, which has been used here for the purpose of providing a power supply to bio–implantable batteryless sensors. The main constraints of the design are to achieve the minimum power required by the application, by still keeping the implant size small enough for the living subject’s body. Resonance–based inductive coupling is a method being actively researched for the use in this type of power transmission, which uses two pairs of inductor coils in the external and implant circuits.

In this work, we …

Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies. Power transfer using magnetically coupled series resonators is maximized when the load presented to the sender is matched to the series impedance of the source. This determines an optimal separation distance between the sender and the receiver. However, the maximum power transferred only depends on the losses in the system and is independent of this distance and the resonant frequency. Closed-form expressions describe the power transferred and efficiency for all distances and system values. These expressions are validated with systems operating at 23 kHz, 40 kHz …

Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies and enable applications that are currently unimaginable because of power constraints. Magnetic induction has been extensively used for wireless power transfer, but its efficiency depends on magnetic coupling that decays as the inverse cube of distance. At long enough distances, the magnetic coupling is weak enough that the effect of the receiver coil on the sender coil can be neglected. In this weakly coupled limit, series resonance in both the sender and the receiver increases the power transfer. Compared to magnetic induction, the power transfer increases …

Wireless Power Transfer For Space Applications: System Design And Electromagnetic Compatibility Compliance Of Radiated Emissions, Ramos Gabriel Vazquez

Electronic Theses and Dissertations

This dissertation evaluates the possibility of wireless power transfer (WPT) systems for space applications, with an emphasis in launch vehicles (rockets). After performing literature review for WPT systems, it was identified that magnetic resonance provides the more suited set of characteristics for this application. Advanced analysis, simulation and testing were performed to magnetic resonance WPT systems to acquire system performance insight. This was accomplished by evaluating/varying coupling configuration, load effects and magnetic element physical characteristics (i.e. wire material, loop radius, etc.). It was identified by analysis, circuit simulation and testing that the best coupling configuration for this application was series-series …

Design Of Wireless Power Transfer And Data Telemetry System For Biomedical Applications, Ashraf Bin Islam

Doctoral Dissertations

With the advancement of biomedical instrumentation technologies sensor based remote healthcare monitoring system is gaining more attention day by day. In this system wearable and implantable sensors are placed outside or inside of the human body. Certain sensors are needed to be placed inside the human body to acquire the information on the vital physiological phenomena such as glucose, lactate, pH, oxygen, etc. These implantable sensors have associated circuits for sensor signal processing and data transmission. Powering the circuit is always a crucial design issue. Batteries cannot be used in implantable sensors which can come in contact with the blood …

Incorporating Wireless Power Transfer In An Led Lighting Application, Jonathan S. Shipley

Theses and Dissertations

There are various situations in which electrical energy is desired but cannot by conveniently supplied. Since the days of Hienrich Hertz and Nikola Tesla, scientists have tried to solve this problem using different methods of wireless power transfer. Today, wireless power transfer has only been commercially demonstrated at small distances through use of induction. This thesis demonstrated the transfer of wireless power at relatively large distances through radio frequencies in the development of a prototype for a commercial product - a wireless household lamp.