Engineering Commons^™

Incremental Quantities Based Permissive Overreaching Transfer Trip Scheme For Protecting Inverter-Based Renewable Resources, Osama Zangoti

Electronic Theses and Dissertations

The power generation landscape evolves, with the increase of inverter-based resources (IBRs) such as solar photovoltaics and wind turbines, providing sustainable and clean energy sources. The shift towards IBRs mitigates climate change, creating considerable challenges to traditional power system protection due to their low fault current. Conventional protection schemes are designed around the internal dynamic of synchronous generators where they can supply an elevated fault current. This thesis explores a protection scheme designed to enhance the security of IBRs. The incremental characteristics of voltage and current coupled with the Permissive Overreaching Transfer Trip scheme (POTT) provide a remarkable ability to …

Optimization-Based Integrated Voltage And Frequency Support For Microgrids Using Energy Storage Systems, Niranjan Bhujel

Electronic Theses and Dissertations

Microgrids have emerged as a promising solution for ensuring the reliability and resilience of future grids, especially with the increasing integration of distributed energy resources (DERs) such as solar, wind, and energy storage systems (ESSs). However, this integration presents significant challenges in the dynamic control of voltage and frequency. Microgrids exhibit a distinctive characteristic marked by a high R/X ratio, resulting in voltage sensitivity to both active and reactive power, while frequency sensitivity is confined to active power. This unique attribute often leads to interference between voltage and frequency support schemes, potentially triggering protection mechanisms and causing localized or cascaded …

Comparative Analysis Of Volt/Var Control Strategies In A Distribution Network, Sahil Aziz

Electronic Theses and Dissertations

This thesis presents a detailed comparative performance analysis of two Volt/VAr (Voltage and Reactive Power) control strategies in distribution networks. The study specifically examines the impact of implementing Volt/VAr control within multiple string inverters on the low-voltage side of a Generator Step-Up (GSU) transformer, in contrast to utilizing a centralized Power Plant Controller (PPC) located on the high-voltage side of a GSU transformer.

The work also estimated the loss in accuracy associated with modeling multiple string inverters as an aggregate, in contrast, to explicitly modeling each inverter and its linked string impedance.

Sic Mosfet Oscillator Circuit For Operation In High-Temperature Harsh Environments: Design, Simulation, And Testing, Nikung Thapa

Electronic Theses and Dissertations

This thesis explores the design, simulation, and validation of a high-temperature (HT) Colpitts oscillator, motivated by the need for robust electronics in HT harsh environments (HE) across sectors such as space exploration, power generation, and industrial processes. The Colpitts oscillator circuit utilizes a silicon carbide (SiC) MOSFET in a source follower amplifier and an LC resonant tank circuit. The circuit was assembled on an alumina board with gold traces using silk-screen printing, and 1mm gold bond wires were employed for component connections. The design and analysis of the oscillator, in both open and closed-loop configurations, involved deriving the transfer function …

Optimization Of Reactive Power Compensation Settings For Solar Power Plants In Volt/Var Mode, Samuel Eniola Aremu

Electronic Theses and Dissertations

Due to advancements in smart inverter technologies, distributed energy resources, such as solar photovoltaic systems, can contribute to network voltage and reactive power regulation in accordance with the IEEE 1547a standard. Depending on the penetration level, the solar photovoltaic system often causes a voltage rise at its connection point and surrounding nodes.

To resolve the voltage rise issue, utilities and developers use strategies like voltage/Var (Volt/Var) and voltage/wattage (Volt/Watt) control, among others. Some electric utilities prefer the Volt/Var control. During Volt/Var operation, PV inverters, based on the Volt/Var settings, can consume reactive power from the network when the voltage at …

Evaluation Of Anodes And Modular Membrane-Less Single Cell Reactor Designs For On-Site Hypochlorous Acid Generation, Nelson C. Chime

Electronic Theses and Dissertations

Ensuring safe drinking water and effective sanitation remains a global priority. The shortages of disinfectants experienced during the COVID-19 pandemic further underscore the importance of reliable disinfection methods. Chlorine-based disinfection is widely used but poses safety hazards and logistical challenges in its traditional production and transportation forms. Alternately, on-site chlorine generation using electrochemical conversion of aqueous sodium chloride offers a promising solution, mitigating these risks and providing a flexible approach to disinfection. This thesis investigates the performance of various anode materials and modular, membrane-less, single-cell reactor designs to optimize on-site chlorine generation. Optimization included minimizing specific electrical consumption for chlorine …

Data-Driven Approaches For Enhancing Power Grid Reliability, Behrouz Sohrabi

Electronic Theses and Dissertations

This thesis explores the transformative potential of data-driven approaches in addressing key operational and reliability issues in power systems. The first part of this thesis addresses a prevalent problem in power distribution networks: the accurate identification of load phases. This study develops a data-driven model leveraging consumption measurements from smart meters and corresponding substation data to reconstruct topology information in low-voltage distribution networks. The proposed model is extensively tested using a dataset with more than 5,000 real load profiles, demonstrating satisfactory performance for large-scale networks. The second part of the thesis pivots to a crucial safety concern: the risk and …

Quantum-Powered Battery Scheduling In Modern Distribution Grids, Diba Ehsani

Electronic Theses and Dissertations

The rising need for exploiting a novel and evolved computation is an increasing concern in the power distribution system to address the exponential growth of distribution-connected devices. Scheduling numerous battery energy storage systems in an optimal way is one of the emerging challenges that will be more noticeable as the number of batteries, including residential, community, and vehicle batteries, increases in the grid. This thesis focuses on this topic and offers a necessary component in building the quantum-compatible distribution system of the future. Using a constrained quadratic model (CQM) on D-Wave’s hybrid solver as well as a binary quadratic model …

Ultrasonic Phased Array Imaging And Data Post Processing With Applications To Resistance Spot Welding, Milos Draskovic

Electronic Theses and Dissertations

Resistance spot welding is a widely used metal joining method in the automotive industry due to its low cost, ease of automation and high throughput. Resistance spot welding is a process that joins two or more metal sheets through the application of force and high current in a localized region, or spot. With the average car containing thousands of such spot welds, some of which compose structural and safety components, the evaluation of the quality metrics related to this process is of key interest to the automotive sector. With this in mind, the evaluation of spot weld parameters including, size, …

Triple Current Control Of Transformer-Less Distributed Generators For Optimal Protection Coordination And Power Oscillation Elimination, Johnny Msawbah

Electronic Theses and Dissertations

Inverter-interfaced distributed generators (IIDGs) face issues related to disruptive power oscillations and overcurrent during unbalanced faults. This thesis focuses on a specific type of IIDGs known as the four-wire IIDG, often referred to as a transformer-less (TL)-IIDG. The TL-IIDG stands out as it possesses the unique capability to completely eliminate power oscillations in both active and reactive power. This is made possible by the addition of a fourth wire, which enhances control capabilities. To address these challenges, a triple current control (TCC) strategy is devised. It leverages sequence currents within a synchronous frame of reference, allowing the creation of a …

Power Electronic Converter Reliability Improvement Optimization Using Genetic Algorithm, Felix Adabla

Electronic Theses and Dissertations

Power electronic converter (PEC) systems are vital for efficient and reliable electrical energy conversion across various applications. Since the overall reliability of these applications is determined, to some degree, by the reliability of the PECs that form the foundation of these applications, it is essential to explore the reliability improvement strategies adopted for these PECs. In fact, various works have been done in that regard. However, another question that arises from these reliability improvement strategies is "how much is enough" since improvement in one area might be at the cost of another factor. In an attempt to answer this question, …

Machine Learning Based Three-Limb Core-Type Transformer Core Aspect Ratios Identification, Ananta Bijoy Bhadra

Electronic Theses and Dissertations

Power transformers are considered one of the key elements of electric grids. Transient studies include transformer transient analysis which is required for the continuous power supply. However, to perform the transient analysis, the details of the internal structure of the transformer are required which are unobtainable and considered as confidential information. Therefore, the application of topological-based transformer models is limited although the models can accurately represent the transformers. To address this concern, a novel approach utilizing Machine Learning (ML) to identify the core aspect ratios of the three-limb core-type transformer is introduced. The proposed approach, using only the voltage and …

Enhancing The Bandwidth And Radiation Characteristics Of Size-Reduced Antennas, Jack P. Nemec

Electronic Theses and Dissertations

Electrically small antennas are researched heavily throughout electromagnetic literature due to their practicality. Antennas need to be able to fit into small places such as cell phones. However, the reduction of antenna size comes at a cost in decreasing the impedance bandwidth and radiation efficiency of the antenna. This research aims to find solutions to having sized-reduced antennas while enhancing both the impedance bandwidth and radiation characteristics of the antenna. First, the size reduction of a dual-element dipole is analyzed. Dual-element dipoles are known to have impedance bandwidth enhancing properties along with the ability to have different radiation modes. Next, …

Optimizing The Reliability Improvement Of Power Electronic Converters Using Different Computational Optimization Techniques, Valentin A. Dun

Electronic Theses and Dissertations

The implementation of renewable energy and decentralization of power generation over the last years created the need for superior technology to be implemented into the grid, which had to transform and integrate these variable renewable energy sources into the existing grid. This technology aims to completely replace the traditional technology in the grid by providing more efficient electricity generation, transmission, and distribution, as well as ensuring benefits such as high reliability, lower cost, higher efficiency, and more compactness, among others. However, the inclusion of power electronic converters into the grid brings many challenges, such as harmonic distortions introduced by power …

Cross-Layer Performance Evaluation Of C-V2x, Dhruba Sunuwar

Electronic Theses and Dissertations

The evolution of connected vehicles from a distant futuristic concept to an integral part of daily life is indisputable. Vehicle-to-everything communication (V2X) serves as the cornerstone of this transformation, facilitating seamless interaction among vehicles, infrastructure, pedestrians, and networks. However, evaluating V2X system performance proves intricate due to the dynamic nature of vehicles influenced by mobility factors. To address this complexity, we have developed a specialized system-level simulator expressly for evaluating V2X communication performance. Notably, the simulator encompasses (i) intelligent transportation system (ITS) scenarios integrated into a geographical framework and (ii) the capability to assess cross-layer performance spanning physical (PHY) and …

Structural Construction And Surface Modification Of Copper Current Collectors For Lithium Metal Batteries, Yaohua Liang

Electronic Theses and Dissertations

Graphene, a prevalent anode material in commercial lithium-ion batteries, has reached its theoretical capacity limit. The imperative is to develop high-capacity anode materials to meet the growing demand for energy density. Lithium metal, renowned for its exceptionally high theoretical specific capacity density (3680 mAh g-1) and low reduction potential (-3.04 V, relative to the standard hydrogen electrode), is commonly dubbed the "Holy Grail" for negative electrode materials in high-energy-density batteries. However, practical advancements in lithium metal anodes face obstacles like low Coulombic efficiency, limited cycle life, and heightened reactivity to the electrolyte and internal short circuits resulting from lithium dendrite …

Optimizing Large Language Models And Multimodal Approaches For Biomedical Publication And Satellite Imagery, Youngsun Jang

Electronic Theses and Dissertations

This dissertation comprises two main sections: the first focuses on natural language processing (NLP) for extracting key information from scientific literature using large language models (LLMs), and the second addresses remote sensing for detecting natural disasters, such as floods, from satellite imagery using a multimodal approach. The first section investigates methods to enhance Transformer-based models in classifying and extracting information from biomedical scientific publications. Key contributions include the development of a custom dataset for classification and Question and Answering (Q&A) tasks, fine-tuning Transformer models like the Bidirectional Encoder Representations from Transformers (BERT) and addressing multi-span answer issues with the TAg-based …