Electrical and Electronics Commons^™

Modeling And Analysis Of Amorphous Steel Transformer For Potential Loss Reduction In Power Systems., Daniel A. Muchow

Theses and Dissertations--Electrical and Computer Engineering

The energy consumed in power systems can be reduced directly by implementing new technologies and materials. The effort to reduce the carbon emissions expelled from the production of electrical energy has become a major focus. According to the U.S. energy Information Administration approximately 5% of all the electric generated and transmitted in the U.S. electrical grid is lost. The energy profile calculated from the usage of electrical power from all 50 states in 2021 is estimated to be 3.8 billion megawatts per hour, with a state average of just over 11 cents per MWh, producing just over 41.8 billion in …

Surface Morphology And Moisture Adsorption/Desorption Characteristics Of Hybrid-Dielectric Moisture Sensors, Ronak Ali

Theses and Dissertations--Electrical and Computer Engineering

Relative humidity sensors are used for high-humidity measurement. Moisture sensors, or dew point sensors are used for low-humidity measurement (< 1 ppm_v). The dissertation contains two parts of studies. In the first part, the effect of surface morphology on the response speed of moisture sensors is studied. Moisture sensors using α-Al₂O₃ films as porous dielectric materials deposited by anodic spark deposition are studied. In this part of the study, a variety of small pores have been studied to investigate the response speed of moisture sensors. Three different surface morphologies have been studied using scanning electron microscopy. One …

Measurement Of Moisture Levels In Oils And Lubricants Using A Novel Moisture Sensor, Aaron Swartz

Theses and Dissertations--Electrical and Computer Engineering

It is very challenging to measure moisture levels in oils. There is not a good method to measure it. Using the novel moisture sensor, we tried various methods to measure the moisture levels in oils. The initial trials are to immerse the sensor chip into the oils to see any sensor reading changes with the change of moisture levels in oils. It was observed that the sensor reading was unstable. The idea for immersion of the sensor chip into the oils failed. The last idea is to heat the oil to let all moisture evaporate fully. Before heating, the dew …

Lifecycle Carbon Footprint And Sustainability Evaluation Of Dram-Based Processing In Memory Computing Architectures, Samrat Pravin Patel

Theses and Dissertations--Electrical and Computer Engineering

The use of computing technologies has significantly enhanced several aspects of our day-to-day lives. But it has still revealed significant environmental concerns, primarily related to greenhouse gas emissions and energy consumption. Initially, the primary environmental problems associated with computing were energy consumption during device operation. However, with the rapid advancement of technology and increasing computational demands, attention has shifted towards the embodied carbon footprint. This term refers to the total greenhouse gas emissions throughout a product’s lifecycle from the extraction of raw materials to end-of-life processing. It has become increasingly significant in the context of manufacturing integrated circuits (ICs), such …

Reinventing Integrated Photonic Devices And Circuits For High Performance Communication And Computing Applications, Venkata Sai Praneeth Karempudi

Theses and Dissertations--Electrical and Computer Engineering

The long-standing technological pillars for computing systems evolution, namely Moore's law and Von Neumann architecture, are breaking down under the pressure of meeting the capacity and energy efficiency demands of computing and communication architectures that are designed to process modern data-centric applications related to Artificial Intelligence (AI), Big Data, and Internet-of-Things (IoT). In response, both industry and academia have turned to 'more-than-Moore' technologies for realizing hardware architectures for communication and computing. Fortunately, Silicon Photonics (SiPh) has emerged as one highly promising ‘more-than-Moore’ technology. Recent progress has enabled SiPh-based interconnects to outperform traditional electrical interconnects, offering advantages like high bandwidth density, …

Electronics Design For Krepe Atmospheric Entry Capsule Avionics, Matt Ruffner

Theses and Dissertations--Electrical and Computer Engineering

This research documents the design, testing, and implementation of sensing, control, and communications subsystems for small atmospheric entry capsules. Atmospheric entry capsules pose a unique electronics design challenge given mission requirements, environmental constraints, and inherent risk involved in space based missions. Previous work on small satellites developed the CubeSat platform as a means of ensuring reliability after university-led small satellite missions experienced failures. The publication of the CubeSat platform allowed researchers to focus on the payload science utilizing a standardized form-factor and reusable electronics. Environmental and operational constraints of CubeSats and atmospheric entry capsules overlap and best-practices associated with building …

Mitigation Of Reflected Overvoltage In Wind-Turbine Generator-Converter Systems With A Smart Coil Concept, Lulu Wei

Theses and Dissertations--Electrical and Computer Engineering

In the recent decade, ultra-fast wide bandgap switching devices such as Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) have been increasingly utilized in power electronic converters for renewable energy power generation systems due to their advantages of enabling high energy efficiency and high power density. However, the much higher voltage slew rate (i.e., dv/dt) with SiC power converters may induce voltage reflection and reliability concerns in machine-converter systems, especially for medium-voltage systems with long cable connections. In wind-turbine power generation systems, generators are typically located in the nacelles, and medium-voltage power converters are mostly placed at the bottom of the …

A Novel Processor Architecture Implementing The Stacked Error Diffusion Algorithm And Its Zynq-Based Realization, Qishi Hu

Theses and Dissertations--Electrical and Computer Engineering

Digital halftoning reproduces continuous-tone images using patterns of black and white dots, while multitoning extends this concept by incorporating inks with intermediate intensities. These techniques are extensively utilized in the printing industry to accommodate the limited range of inks available in printers. Stacked error diffusion is a high-quality multitoning algorithm that adheres to the blue-noise dithering standard. This thesis research studies the potential parallelism inherent in the algorithm and introduces the design of a novel processor architecture optimized for efficient execution. The architecture is realized on an FPGA development board featuring a Zynq SoC. Additionally, the hardware prototype can also …

Development Of Dc Circuit Breakers For Medium-Voltage Electrified Transportation, Trevor Morgan Arvin

Theses and Dissertations--Electrical and Computer Engineering

Medium-voltage DC (MVDC) distribution is an enabling technology for the electrification of transportation such as aircraft and shipboard. One main obstacle for DC distribution is the lack of adequate circuit fault protection. The challenges are due to the rapidly rising fault currents and absence of zero crossings in DC systems compared to AC counterparts. Existing DC breaker solutions lack comprehensive consideration of energy efficiency, power density, fault interruption speed, reliability, and implementation cost.

In this thesis, two circuit topologies of improved DC circuit breakers are developed: the resonant current source based hybrid DC breaker (RCS-HDCB) and the high temperature superconductor …

Parametric Average-Value Modeling, Simulation, And Characterization Of Machine-Rectifier Systems, Isuje Ojo

Theses and Dissertations--Electrical and Computer Engineering

There are many techniques for modeling and simulation of synchronous machine-rectifier systems. The more common approaches are the detailed and average-value modeling techniques. The detailed simulation technique takes into account the details of the diode switching and is both very accurate and very expensive in terms of computational resources. To alleviate this disadvantage, the average-value modeling technique is often utilized. In this approach, the details of diode switching are neglected or averaged. In that light, the work presented herein proposes a unique saliency-sensitive parametric average-value model (SSPAVM) of the synchronous machine-rectifier system. This model extends existing parametric average-value models to …

Development Of A Hybrid-Electric Aircraft Propulsion System Based On Silicon Carbide Triple Active Bridge Multiport Power Converter, Cole M. Ivey

Theses and Dissertations--Electrical and Computer Engineering

Constrained by the low energy density of Lithium-ion batteries with all-electric aircraft propulsion, hybrid-electric aircraft propulsion drive becomes one of the most promising technologies in aviation electrification, especially for wide-body airplanes. In this thesis, a three-port triple active bridge (TAB) DC-DC converter is developed to manage the power flow between the turbo generator, battery, and the propulsion motor. The TAB converter is modeled based on the emerging Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) modules operating at high switching frequency, so the size of the magnetic transformer can be significantly reduced. Different operation modes of this hybrid-electric propulsion drive …

Special Power Electronics Converters And Machine Drives With Wide Band-Gap Devices, Yibin Zhang

Theses and Dissertations--Electrical and Computer Engineering

Power electronic converters play a key role in power generation, storage, and consumption. The major portion of power losses in the converters is dissipated in the semiconductor switching devices. In recent years, new power semiconductors based on wide band-gap (WBG) devices have been increasingly developed and employed in terms of promising merits including the lower on-state resistance, lower turn-on/off energy, higher capable switching frequency, higher temperature tolerance than conventional Si devices. However, WBG devices also brought new challenges including lower fault tolerance, higher system cost, gate driver challenges, and high dv/dt and resulting increased bearing current in electric machines.

This …

Electric Power Systems And Components For Electric Aircraft, Damien Lawhorn

Theses and Dissertations--Electrical and Computer Engineering

Electric aircraft have gained increasing attention in recent years due to their potential for environmental and economic benefits over conventional airplanes. In order to offer competitive flight times and payload capabilities, electric aircraft power systems (EAPS) must exhibit extremely high efficiencies and power densities. While advancements in enabling technologies have progressed the development of high performance EAPS, further research is required.

One challenge in the design of EAPS is determining the best topology to be employed. This work proposes a new graph theory based method for the optimal design of EAPS. This method takes into account data surveyed from a …

Toward Intelligent Welding By Building Its Digital Twin, Qiyue Wang

Theses and Dissertations--Electrical and Computer Engineering

To meet the increasing requirements for production on individualization, efficiency and quality, traditional manufacturing processes are evolving to smart manufacturing with the support from the information technology advancements including cyber-physical systems (CPS), Internet of Things (IoT), big industrial data, and artificial intelligence (AI). The pre-requirement for integrating with these advanced information technologies is to digitalize manufacturing processes such that they can be analyzed, controlled, and interacted with other digitalized components. Digital twin is developed as a general framework to do that by building the digital replicas for the physical entities. This work takes welding manufacturing as the case study to …

Rapid Prototyping Of Nanostructures With Electron Beam Induced Processing, Samaneh Esfandiarpour

Theses and Dissertations--Electrical and Computer Engineering

Focused electron beam induced processing (FEBIP) is a nano-scale fabrication technique that allows the direct deposition of functional materials. However, it suffers from significant drawbacks, such as high cost, low speed, unavailable precursors for many materials and low purity of deposits. Liquid-phase focused electron beam induced processes (LP-FEBIP) are being investigated due to the potential benefits over the gas phase technique. In this method, deposition or etching occurs at the interface between a substrate and a bulk liquid. In this work, electron beam induced deposition of copper nanostructures from aqueous solutions of copper sulfate is demonstrated. The addition of sulfuric …

End-To-End Prediction Of Weld Penetration In Real Time Based On Deep Learning, Wenhua Jiao

Theses and Dissertations--Electrical and Computer Engineering

Welding is an important joining technique that has been automated/robotized. In automated/robotic welding applications, however, the parameters are preset and are not adaptively adjusted to overcome unpredicted disturbances, which cause these applications to not be able to meet the standards from welding/manufacturing industry in terms of quality, efficiency, and individuality. Combining information sensing and processing with traditional welding techniques is a significant step toward revolutionizing the welding industry. In practical welding, the weld penetration as measured by the back-side bead width is a critical factor when determining the integrity of the weld produced. However, the back-side bead width is difficult …

Resource Efficient Design Of Quantum Circuits For Cryptanalysis And Scientific Computing Applications, Edgard Munoz-Coreas

Theses and Dissertations--Electrical and Computer Engineering

Quantum computers offer the potential to extend our abilities to tackle computational problems in fields such as number theory, encryption, search and scientific computation. Up to a superpolynomial speedup has been reported for quantum algorithms in these areas. Motivated by the promise of faster computations, the development of quantum machines has caught the attention of both academics and industry researchers. Quantum machines are now at sizes where implementations of quantum algorithms or their components are now becoming possible. In order to implement quantum algorithms on quantum machines, resource efficient circuits and functional blocks must be designed. In this work, we …

Fabrication And Characterization Of Planar-Structure Perovskite Solar Cells, Guoduan Liu

Theses and Dissertations--Electrical and Computer Engineering

Currently organic-inorganic hybrid perovskite solar cells (PSCs) is one kind of promising photovoltaic technology due to low production cost, easy fabrication method and high power conversion efficiency.

Charge transport layers are found to be critical for device performance and stability. A traditional electron transport layer (ETL), such as TiO₂ (Titanium dioxide), is not very efficient for charge extraction at the interface. Compared with TiO₂, SnO₂ (Tin (IV) Oxide) possesses several advantages such as higher mobility and better energy level alignment. In addition, PSCs with planar structure can be processed at lower temperature compared to PSCs with …

Mathematical Programming Approach For The Design Of Satellite Power Systems, Allen Flath Iii

Theses and Dissertations--Electrical and Computer Engineering

Satellite power systems can be understood as islanded dc microgrids supplied by specialized and coordinated solar cell arrays augmented by electrochemical battery systems to handle high-power loads and periods of eclipse. The periodic availability of power, the limited capacity of batteries, and the dependence of all mission service on power consumption create a unique situation in which temporal power and energy scarcity exist. A multi-period model of an orbital satellite power system’s performance over a mission’s duration can be constructed. A modular power system architecture is used to characterize the system’s constraints. Using mathematical programming, an optimization problem can be …

Curricular Optimization: Solving For The Optimal Student Success Pathway, William G. Thompson-Arjona

Theses and Dissertations--Electrical and Computer Engineering

Considering the significant investment of higher education made by students and their families, graduating in a timely manner is of the utmost importance. Delay attributed to drop out or the retaking of a course adds cost and negatively affects a student’s academic progression. Considering this, it becomes paramount for institutions to focus on student success in relation to term scheduling.

Often overlooked, complexity of a course schedule may be one of the most important factors in whether or not a student successfully completes his or her degree. More often than not students entering an institution as a first time full …

Optimum Design Of Axial Flux Pm Machines Based On Electromagnetic 3d Fea, Narges Taran

Theses and Dissertations--Electrical and Computer Engineering

Axial flux permanent magnet (AFPM) machines have recently attracted significant attention due to several reasons, such as their specific form factor, potentially higher torque density and lower losses, feasibility of increasing the number of poles, and facilitating innovative machine structures for emerging applications. One such machine design, which has promising, high efficiency particularly at higher speeds, is of the coreless AFPM type and has been studied in the dissertation together with more conventional AFPM topologies that employ a ferromagnetic core.

A challenge in designing coreless AFPM machines is estimating the eddy current losses. This work proposes a new hybrid analytical …

Contributions To Hybrid Power Systems Incorporating Renewables For Desalination Systems, Nasser Alawhali

Theses and Dissertations--Electrical and Computer Engineering

Renewable energy is one of the most reliable resource that can be used to generate the electricity. It is expected to be the most highly used resource for electricity generation in many countries in the world in the next few decades. Renewable energy resources can be used in several purposes. It can be used for electricity generation, water desalination and mining. Using renewable resources to desalinate the water has several advantages such as reduce the emission, save money and improve the public health. The research described in the thesis focuses on the analysis of using the renewable resources such as …

Real-Time Image Pattern Sensor For Weld Pool Penetration Through Reflection In Gtaw, Yu-Ting Chen

Theses and Dissertations--Electrical and Computer Engineering

In gas tungsten arc welding (GTAW), weld pool surface contains crucial information for welding development. In this research, simulate skilled welders to control the welding process and determine the penetration stages based on the weld pool reaction.

This study focuses on solving the uncertainty of the liquid weld pool in joint bases. The weld pool penetration process is highly depending on how the weld pool surface shape. To observe the weld pool, reflect the weld pool surface by the laser and image on the shield glass. The experiments show that the penetration can’t be determine by the reflecting grayness due …

Design Of A Machine Vision Camera For Spatial Augmented Reality, Matt Phillip Ruffner

Theses and Dissertations--Electrical and Computer Engineering

Structured Light Imaging (SLI) is a means of digital reconstruction, or Three-Dimensional (3D) scanning, and has uses that span many disciplines. A projector, camera and Personal Computer (PC) are required to perform such 3D scans. Slight variances in synchronization between these three devices can cause malfunctions in the process due to the limitations of PC graphics processors as real-time systems. Previous work used a Field Programmable Gate Array (FPGA) to both drive the projector and trigger the camera, eliminating these timing issues, but still needing an external camera. This thesis proposes the incorporation of the camera with the FPGA SLI …

Stability Analysis And Design Of A Tracking Filter For Variable Frequency Applications, Pranav Aramane

Theses and Dissertations--Electrical and Computer Engineering

The work presented in this thesis is a frequency adaptive tracking filter that can be used in exact tracking of power frequencies and rejection of unwanted harmonics introduced during power disturbances. The power synchronization process includes power converters and other equipment that have many non-linear components that introduce unwanted harmonics. This new design is motivated by the requirement of a filter that can filter all the harmonics and exactly track a rapidly varying fundamental frequency with little time delay and phase error. This thesis analyzes the proposed filter mathematically based on Lyapunov theory and simulations are presented to show the …

Fabrication And Characterization Of Organic-Inorganic Hybrid Perovskite Solar Cells, Hojjatollah Sarvari

Theses and Dissertations--Electrical and Computer Engineering

Solar energy as the most abundant source of energy is clean, non-pollutant, and completely renewable, which provides energy security, independence, and reliability. Organic-inorganic hybrid perovskite solar cells (PSCs) revolutionized the photovoltaics field not only by showing high efficiency of above 22% in just a few years but also by providing cheap and facile fabrication methods.

In this dissertation, fabrication of PSCs in both ambient air conditions and environmentally controlled N₂-filled glove-box are studied. Several characterization methods such as SEM, XRD, EDS, Profilometry, four-point probe measurement, EQE, and current-voltage measurements were employed to examine the quality of thin films …

Advanced Synchronous Machine Modeling, Yuqi Zhang

Theses and Dissertations--Electrical and Computer Engineering

The synchronous machine is one of the critical components of electric power systems. Modeling of synchronous machines is essential for power systems analyses. Electric machines are often interfaced with power electronic components. This work presents an advanced synchronous machine modeling, which emphasis on the modeling and simulation of systems that contain a mixture of synchronous machines and power electronic components. Such systems can be found in electric drive systems, dc power systems, renewable energy, and conventional synchronous machine excitation. Numerous models and formulations have been used to study synchronous machines in different applications. Herein, a unified derivation of the various …

Improvements In Inverter Modeling And Control, Xiao Liu

Theses and Dissertations--Electrical and Computer Engineering

In this dissertation, the generalized averaging method models for inverters, reactive power control methods for photovoltaic inverters, and a noise immunity improvement for hybrid position observers for brushless dc motor drives are studied.

Models of inverters and other converters based on averaging have been widely used in numerous simulation applications. Generalized averaging can be applied to model both average and switching behavior of converters while retaining the faster run times associated with average-value models. Herein, generalized average models for single- and three-phase pulse width modulation inverters are proposed. The modulation signal for the proposed model could be either a sinusoidal …

Electron Beam Induced Deposition Of Highly Conductive Copper Nanowires From Bulk Liquids, Amjad M. Syam

Theses and Dissertations--Electrical and Computer Engineering

Electron-beam induced deposition (EBID) is a position-controlled technique that can directly fabricate nanometer-sized structures in functional materials. In the standard process, a gaseous precursor delivers the desired substance to the substrate for deposition. However, the material purity from these precursors is typically poor, which often negatively affects the functional properties of the deposit. Recently, bulk liquid precursors have been investigated as promising reactants for high purity deposition without the need for post-processing. In this work, EBID from bulk liquids is shown to yield highly conductive nanowire deposits. Aqueous solutions containing copper sulfate (CuSO₄) and sulfuric acid (H_{2 …}

A Lithium Battery Current Estimation Technique Using An Unknown Input Observer, Daniel Cambron

Theses and Dissertations--Electrical and Computer Engineering

Current consumption measurements are useful in a wide variety of applications, including power monitoring and fault detection within a lithium battery management system (BMS). This measurement is typically taken using either a shunt resistor or a Hall-effect current transducer. Although both methods have achieved accurate current measurements, shunt resistors have inherent power loss and often require isolation circuitry, and Hall-effect sensors are generally expensive. This work explores a novel alternative to sensing battery current by measuring terminal voltages and cell temperatures and using an unknown input observer (UIO) to estimate the battery current. An accurate model of a LiFePO_{4 …}