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Maschino, Tyler StephenFREQUENCY-SELECTIVE DESIGN OF WIRELESS POWER TRANSFER SYSTEMS FOR CONTROLLED ACCESS APPLICATIONS
Master of Science, Miami University, 2016, Computational Science and Engineering
Wireless power transfer (WPT) has become a common way to charge or power many types of devices, ranging from cell phones to electric toothbrushes. WPT became popular through the introduction of a transmission mode known as strongly coupled magnetic resonance (SCMR). This means of transmission is non-radiative and enables mid-range WPT. Shortly after the development of WPT via SCMR, a group of researchers introduced the concept of resonant repeaters, which allows power to hop from the source to the device. These repeaters are in resonance with the WPT system, which enables them to propagate the power wirelessly with minimal losses to the environment. Resonant repeaters have rekindled the dream of ubiquitous wireless power. Inherent risks come with the realization of such a dream. One of the most prominent risks, which we set out in this thesis to address, is that of accessibility to the WPT system. We propose the incorporation of a controlled access schema within a WPT system to prevent unwarranted use of wireless power. Our thesis discusses the history of electromagnetism, examines the inception of WPT via SCMR, evaluates recent developments in WPT, and further elaborates on the controlled access schema we wish to contribute to the field.

Committee:

Dmitriy Garmatyuk, PhD (Advisor); Mark Scott, PhD (Committee Member); Herbert Jaeger, PhD (Committee Member)

Subjects:

Computer Engineering; Electrical Engineering; Electromagnetics; Electromagnetism; Engineering

Keywords:

wireless power transfer; WPT; resonance; magnetic resonance; electromagnetism; power security; power encryption; wireless power transfer security; wireless power transfer encryption; SCMR; strongly coupled magnetic resonance; power transfer;

Heebl, Jason DanielDevelopment and Characterization of a Tunable Resonant Shielded Loop Wireless Non-Radiative Power Transfer System
Master of Science (M.S.), University of Dayton, 2011, Electrical Engineering
In this thesis, the theory of coupled resonators for non-adiative wireless power transfer are explored from a lumped element circuit perspective. A basic circuit model is developed and standard circuit parameters are defined. A directly fed resonant shielded loop for wireless power transfer is presented. Basic lumped component values and circuit parameters are experimentally extracted for two resonant shielded loops. Optimal efficiency conditions are derived and used to design optimal matching networks. Matching networks are constructed and the system is tested for power transfer efficiency. Two means of producing a tunable system are explored: frequency tuned sources and dynamic matching networks. It is shown that frequency tuned systems cannot achieve maximum efficiencies. A tunable system is constructed and tested. Experimental results show excellent agreement with theory, and the ability to achieve maximum achievable efficiencies.

Committee:

Robert Penno, PhD (Committee Chair); Anthony Grbic, PhD (Advisor); Monish Chatterjee, PhD (Committee Member); Augustine Urbas, PhD (Committee Member); John Weber, PhD (Other); Tony Saliba, PhD (Other)

Subjects:

Electrical Engineering; Electromagnetics; Electromagnetism; Energy; Engineering; Solid State Physics

Keywords:

Wireless; Power; Transfer; WNPT; resonant; shielded loop; non-radiative; wireless power transfer; WPT

Patterson, Mark AlanA Passive Wireless Platform for Chemical-Biological Sensors
Doctor of Philosophy (Ph.D.), University of Dayton, 2012, Electrical Engineering
This research presents several different platforms for detecting chemical or biological agents without the use of probes or wires and without the use of a battery. These platforms all use an interrogator to transmit power through either radio or low frequency electromagnetic waves to a sensor device. The sensor device has a functionalized surface which aids in selectivity to the analyte of interest. The sensor device sends back a portion of the power through radio frequency waves with altered frequency, amplitude and phase. The characteristics of the received signal contain the information about the analyte of interest. The platforms were tested with several volatile organic compounds, gasoline, sulfuric acid, hydraulic fluid, and chlorine. The results were statistically significant.

Committee:

Guru Subramanyam, Ph.D (Committee Chair); Partha Banerjee, Ph.D (Committee Member); Malcolm Daniels, Ph.D (Committee Member); James Grote, Ph.D (Committee Member)

Subjects:

Biomedical Engineering; Electrical Engineering; Electromagnetics

Keywords:

chemical sensor; wireless power transfer

Danekar, Abhishek V.Analysis and Design of High-Frequency Soft-Switching DC-DC Converter for Wireless Power Charging Applications
Master of Science in Electrical Engineering (MSEE), Wright State University, 2017, Electrical Engineering
Wireless power transfer (WPT) technology is becoming attractive in a wide variety of applications such as electric-vehicle charging, induction heating, charging portable applications, industrial robots, and biomedical implants. Recent studies have shown various techniques to implement wireless power transfer and these techniques differ based on the type of applications. For example, for electric vehicle charging, the power levels are in the range 5 kW to 25 kW and the operating frequency is in the range 70 kHz to 110 kHz. On the other hand, for consumer applications, the power levels vary from a few watts to hundreds of watts and operates at frequencies of the order of 5 MHz to 10 MHz. This thesis addresses the analysis, design, implementation, and simulation of a wireless charging system targeted towards a high-frequency, low-power portable application with wide separation between transmitter and receiver. The WPT system is composed of three important blocks: inverter (or transmitter), transformer (or coil), and rectifier (or receiver). Hard-switching inverters and rectifiers have major drawbacks at high frequencies due to large switching power loss. Therefore, soft-switching Class-E topology is chosen. The Class-E dc-ac inverter with CLL resonant tank, also referred to as pi2a impedance matching network is analyzed, designed, and simulated to observe its superior performance over other topologies at varying coupling coefficients and loads. Four soft-switching rectifier topologies are analyzed, designed, and simulated to evaluate their behavior at high frequencies. Their compatibility with Class-E inverters in the presence of loosely-coupled transformers is discussed. The physical and commercial limitations of using transformers with magnetic core is presented. Therefore, the preferred solution, an air-core transformer is designed and integrated with the rectifier to evaluate their characteristics at selected coupling coefficient. The overall system including the inverter, loosely-coupled air-core transformer, and rectifier was designed for the following specifications: operating frequency 6.78 MHz, output power across a single-load 40 W, output voltage 25 V, and target coupling coefficient of 0.5. Simulation results have been provided to validate the theoretical predictions. The major challenges faced during the integration of these building blocks are addressed. Finally, conclusions, contributions, and scope for future work are provided.

Committee:

Marian Kazimierczuk, Ph.D. (Advisor); Saiyu Ren, Ph.D. (Committee Member); Yan Zhuang, Ph.D. (Committee Member)

Subjects:

Electrical Engineering; Electromagnetics; Electromagnetism; Engineering

Keywords:

Power converters; Inverter; Rectifier; Transformer; High frequency wireless power transfer; Impedance matching; Electrical engineering; Soft switching; ZVS; ZCS