Electrical and Computer Engineering Commons^™

Static And Dynamic State Estimation Applications In Power Systems Protection And Control Engineering, Ibukunoluwa Olayemi Korede

Doctoral Dissertations

The developed methodologies are proposed to serve as support for control centers and fault analysis engineers. These approaches provide a dependable and effective means of pinpointing and resolving faults, which ultimately enhances power grid reliability. The algorithm uses the Least Absolute Value (LAV) method to estimate the augmented states of the PCB, enabling supervisory monitoring of the system. In addition, the application of statistical analysis based on projection statistics of the system Jacobian as a virtual sensor to detect faults on transmission lines. This approach is particularly valuable for detecting anomalies in transmission line data, such as bad data or …

Fourier Analysis And Optimization Of Inductive Wireless Power Transfer For Electric Vehicle Charging, Andrew P. Foote

Doctoral Dissertations

With the growth of electric vehicle (EV) popularity, different charging options to increase user convenience and reduce charging time such as high power wireless charging are increasingly being developed and researched. Inductive wireless power transfer (WPT) systems for EVs must meet specifications such as stray field, battery power and voltage operating range, efficiency, and ground clearance. The coil geometry and design have a large impact in meeting these constraints. Typical design approaches include iterative analysis of predetermined coil geometries to identify candidates that meet these constraints.

This work instead directly generates WPT coil shapes and magnetic fields to meet specifications …

Additive Manufacturing Of Magnetic Materials For Electric Motor And Generator Applications, Haobo Wang

Doctoral Dissertations

This work details the research into the 3D Printing, also known as Additive Manufacturing (AM), of both impermanent and permanent magnets. This work also details the research in enabling such AM magnets in electrical machine applications, primarily motors and generators. The AM processes of many types of magnets are described in detail. The material properties of such AM magnets are also described. The two main types of AM magnets that are discussed in detail are AM NdFeB, and AM Silicon Steel. The implementation of AM NdFeB as rotor magnets, and the implementation of AM Silicon Steel as rotor and stator …

A Case Study In Cmos Design Scaling For Analog Applications: The Ringamp Ldo, Steven Corum

Masters Theses

As CMOS process nodes scale to smaller feature sizes, process optimizations are made to achieve improvements in digital circuit performance, such as increasing speed and memory, while decreasing power consumption. Unfortunately for analog design, these optimizations usually come at the expense of poorer transistor performance, such as reduced small signal output resistance and increased channel length modulation. The ring amplifier has been proposed as a digital solution to the analog scaling problem, by configuring digital inverters to function as analog amplifiers through deadzone biasing. As digital inverters naturally scale, the ring amplifier is a promising area of exploration for analog …

Generalized Participation Factors On Nonlinear Power System Oscillations, Tianwei Xia

Doctoral Dissertations

This work investigates the linear and nonlinear participation factors in power system oscillations, introducing novel model-based and measurement-based approaches for stability analysis.

From the measurement perspective, this research proposes a method for estimating participation factors from generator response measurements under diverse disturbances. The devised technique computes extended participation factors that align precisely with model-based factors, given that the measured responses satisfy an ideally symmetric condition. The symmetric condition is further relaxed by identifying a coordinate transformation from the original measurement space to an optimally symmetric space, thereby achieving the ideal estimation of participation factors from measurements alone. The effectiveness of …

The Synthesis And Optimization Of Sulfide And Halide Solid Electrolytes For All Solid-State Batteries, Teerth Brahmbhatt

Doctoral Dissertations

Countries and organizations around the world have established ambitious targets to transition away from fossil fuel-based energy sources and devices. The transition is focused on cleaning up power generation by converting coal, natural gas, and oil-based power generation to renewables and nuclear energy. Decarbonizing other sectors of energy use, transportation for example, will require broader electrification. To drive this move away from fossil fuel powered transportation will require portable energy storage devices. Conventional lithium-ion batteries are a popular candidate to lead this shift. However, these batteries often rely on flammable liquid electrolytes and carbon anodes that suffer from low energy …

Deep Learning Based Power System Stability Assessment For Reduced Wecc System, Yinfeng Zhao

Doctoral Dissertations

Power system stability is the ability of power system, for a giving initial operating condition, to reach a new operation condition with most of the system variables bounded in normal range after subjecting to a short or long disturbance. Traditional power system stability mainly uses time-domain simulation which is very time consuming and only appropriate for offline assessment.

Nowadays, with increasing penetration of inverter based renewable, large-scale distributed energy storage integration and operation uncertainty brought by weather and electricity market, system dynamic and operating condition is more dramatic, and traditional power system stability assessment based on scheduling may not be …

Impact Of Renewables On Grid Strength, Transient Stability, And Grid Operation Characterization, Abigail E. Till

Doctoral Dissertations

Increasing amounts of inverter based resources (IBR) are being added to the grid. With environmental and climate change concerns, even more is projected to be added. Many companies and regions are setting goals for high levels of renewables.

As IBR are added to the grid, it changes how the power system responds to disturbances. With less traditional synchronous machines on the system, this decreases the inertia and can add stability concerns. Studies are required to know how power systems will respond to the change in generation resources. This dissertation contributes to studying transient stability and grid strength on the North …

Resiliency Of Power Systems In The Cyber Layer: Application To Load Forecasting And Security Assessment, Mojtaba Dezvarei

Doctoral Dissertations

Integrating sensors, actuators, and communication infrastructure in the electrical grid creates a smart grid, known as a cyber-physical system (CPS), which combines the physical framework with a cyber layer. The cyber layer is crucial as it houses the decision-making responsible for reliable operation. However, the complexity of the physical layers, due partly to the deployment of integrated battery resources (IBRs), and the cyber layer itself, introduces challenges such as reliance on measurement quality and vulnerability to data corruption from cyber threats. These challenges result in uncertainties in the CPS framework, emphasizing the need for accurate and robust responses from the …

Impacts Of High Renewable Power Grids On System Planning And Monitoring, Zhihao Jiang

Doctoral Dissertations

To achieve the goal of a carbon pollution-free electricity sector by 2035 proposed by Biden’s Administration, the U.S. power grids are expecting a dramatic transformation in the resource mix of electricity generation. This dissertation will present related research in several different aspects that will be largely affected by the clean energy transition.

The increasing size and complexity of the bulk power systems have made it more computationally burdensome to simulate the power system in full-size. As an alternative to traditional model-based methods, Chapter 2 proposes a measurement-based model reduction approach using system identification techniques. Chapter 3 presents a parameter fine-tuning …

An Automated, Deep Learning Approach To Systematically & Sequentially Derive Three-Dimensional Knee Kinematics Directly From Two-Dimensional Fluoroscopic Video, Viet Dung Nguyen

Doctoral Dissertations

Total knee arthroplasty (TKA), also known as total knee replacement, is a surgical procedure to replace damaged parts of the knee joint with artificial components. It aims to relieve pain and improve knee function. TKA can improve knee kinematics and reduce pain, but it may also cause altered joint mechanics and complications. Proper patient selection, implant design, and surgical technique are important for successful outcomes. Kinematics analysis plays a vital role in TKA by evaluating knee joint movement and mechanics. It helps assess surgery success, guides implant and technique selection, informs implant design improvements, detects problems early, and improves patient …

Development Of A Soft Robotic Approach For An Intra-Abdominal Wireless Laparoscopic Camera, Hui Liu

Doctoral Dissertations

In Single-Incision Laparoscopic Surgery (SILS), the Magnetic Anchoring and Guidance System (MAGS) arises as a promising technique to provide larger workspaces and field of vision for the laparoscopes, relief space for other instruments, and require fewer incisions. Inspired by MAGS, many concept designs related to fully insertable magnetically driven laparoscopes are developed and tested on the transabdominal operation. However, ignoring the tissue interaction and insertion procedure, most of the designs adopt rigid structures, which not only damage the patients' tissue with excess stress concentration and sliding motion but also require complicated operation for the insertion. Meanwhile, lacking state tracking of …

Heuristics For Lagrangian Relaxation Formulations For The Unit Commitment Problem, Stephen Opeyemi Fatokun

Doctoral Dissertations

The expansion of distributed energy resources (DER), demand response (DR), and virtual bidding in many power systems and energy markets are creating new challenges for unit commitment (UC) and economic dispatch (ED) techniques. Instead of a small number of traditionally large generators, the power system resource mix is moving to one with a high percentage of a large number of small units. These can increase the number of similar or identical units, leading to chattering (switching back and forth among committed units between iterations). This research investigates alternative and scalable ways of increasing the high penetration of these resources.

First, …

Reducing The Levelized Cost Of Energy Of Residential Pv Inverters Through Dynamic Hardware Allocation, Kamal Sabi

Doctoral Dissertations

Renewable energy, such as wind and solar are becoming an integral part of world energy production. Photovoltaic (PV) systems are projected to constitute a large portion of the energy generation portfolio. Achieving a low-cost residential PV system will enable the wide adoption of solar energy throughout the USA. Although innovation in several areas is required to achieve this goal of a low-cost residential PV system, inverter reliability innovation is one key area that is essential. Present string inverters' lifetime is less than 15 years. Increasing their lifetime to 50 years will reduce the cost of operation and maintenance, increase energy …

Data-Driven Situation Awareness For Power System Frequency Dynamics, Hongyu Li

Doctoral Dissertations

As the penetration of renewable energy increases, system inertia decreases, causing changes in system frequency dynamics. The power industry desires situation awareness of power system frequency dynamics to ensure secure and economic operation and control. Moreover, FNET/Grideye has abundant measured data from power systems, making it possible to conduct data-driven situation awareness studies on power system frequency dynamics. This doctoral dissertation proposes several contributions: (a) Two accurate generator trip event MW estimation methods are proposed, in which one is based on long window RoCoF and another is based on multi-Beta values; (b) Two real-time system inertia estimation approaches are developed …

Measurement-Based Monitoring And Control In Power Systems With High Renewable Penetrations, Chengwen Zhang

Doctoral Dissertations

Power systems are experiencing rapid changes in their generation mixes because of the increasing integration of inverter-based resources (IBRs) and the retirement of traditional generations. This opens opportunities for a cleaner energy outlook but also poses challenges to the safe operation of the power networks. Enhanced monitoring and control based on the increasingly available measurements are essential in assisting stable operation and effective planning for these evolving systems.

First, awareness of the evolving dynamic characteristics is quintessential for secure operation and corrective planning. A quantified monitoring study that keeps track of the inertial response and primary frequency response is conducted …

Multiple Objective Co-Optimization Of Switched Reluctance Machine Design And Control, Timothy Burress

Doctoral Dissertations

This dissertation includes a review of various motor types, a motivation for selecting the switched reluctance motor (SRM) as a focus of this work, a review of SRM design and control optimization methods in literature, a proposed co-optimization approach, and empirical evaluations to validate the models and proposed co-optimization methods.

The switched reluctance motor (SRM) was chosen as a focus of research based on its low cost, easy manufacturability, moderate performance and efficiency, and its potential for improvement through advanced design and control optimization. After a review of SRM design and control optimization methods in the literature, it was found …

A Low Power, Rad-Hard, Ecl Standard Cell Library, Zakaraya A. Hamdan

Masters Theses

Space exploration for life both inside and outside of our solar system demand the design and fabrication of robust, reliable electronics that can take measurements, process data, and sustain necessary operations. However, the presence of high radiation and the cold temperature of space poses a challenge to most designers. This thesis presents the design of a radiation-hardened, cold capable emitter coupled logic standard cell library with the intention of being used for space applications. The cells are designed and fabricated in a 90nm silicon germanium BiCMOS process. First, a review of emitter coupled logic is presented. Then, the design methodology …

An Isostable Coordinate Based Amelioration Strategy To Mitigate The Effects Of Jet Lag, Talha Ahmed

Masters Theses

Commercial air travel has become extremely commonplace in the last 20 to 30 years especially as the world has moved towards new heights of globalization. Though air travel has greatly reduced transit times allowing people to cover thousand of miles within hours, it comes with its fair share of issues. jet-lag can be regarded to be at the top of those list of problems; jet-lag typically results from rapid travel through multiple time zones which causes a significant misalignment between the person's internal circadian clock and the external time. A person's circadian clock is governed by a population of coupled …