Power and Energy Commons^™

Considerations On Direct Balancing Of Ultra-High Power Ac Arc Furnaces In Uneasy State, Ikenna Louis Ezeonwumelu

LSU Master's Theses

During the operation of ultra-high-power ac arc furnace the negative effects of unbalance mostly occur in the secondary terminals of the transformer connected to the load. Hence balancing and compensating the furnace at this terminal will not only improve the transformer efficiency but also reduce energy losses that do occur. In this thesis a computer modeling of a reference ac arc furnace in both balanced and unbalanced states were simulated, and the effects of a reactive balancing compensator installed on the secondary side of the furnace transformer was evaluated to see how much delivered energy improvement can be obtained. The …

Developing A 1-Megawatt Photovoltaic Power Plant For Liberty University, Andrew Knudsen

Senior Honors Theses

A photovoltaic power plant with a generation capacity of 1-megawatt is designed for Liberty University. Liberty University’s location and size are stated to provide context for the design. Design choices are presented, first with general information that is applicable to any photovoltaic plant design, then with significant factors that impact this design. Specific models of solar panels and inverters are selected after the necessary classifications are determined. The final design has 2,880 solar panels with a fixed angle 30⁰ above the horizon, has two central inverters, and takes up 2.57 acres. Future research is suggested for finances as well as …

Investigation Of Microfluidic Kelvin Water Dropper And Its Applications In Contact And Contactless Electrowetting, Elias Yazdanshenas

Mechanical & Aerospace Engineering Theses & Dissertations

A typical Kelvin water dropper is a device that can convert gravitational potential energy to a high voltage electrostatic. This device consists of two inductors, two collectors, tubes, and electrical connections. A Kelvin water dropper is able to generate extremely high voltage by separating ions using two positive feedback loops. A Kelvin water dropper provides a low cost solution for the applications in which high voltage is needed. In the present research, low cost Microfluidic Kelvin Water Droppers (MKWDs) were developed and built in house for electrowetting applications. Two MKWDs with different tube inner diameters (254 and 508 μm) were …

New Method Of Nickel Oxide As Hole Transport Layer And Characteristics Of Nickel Oxide Based Perovskite Solar Cell, Loi Nguyen

Electrical & Computer Engineering Theses & Dissertations

For perovskite solar cells, poly (2,3-dihydrothieno-1, 4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS) is a common hole transport layer. However, PEDOT:PSS has a lot of drawbacks, such as irregular quality from distributors, poor electron blocker, and hygroscopic nature. On the other hand, NiOx has been reported that it can provide good stability and carrier mobility. From literature, NiOx was used to replace PEDOT:PSS as a hole transport layer with positive results since it is transparent as a thin film and also possesses compatible work function in perovskite solar cell bandgap alignment. In depositing NiOx as a thin film, many approaches have been developed. However, …

Special Perturbations On The Jetson Tx1 And Tx2 Computers, Tyler M. Moore

Theses and Dissertations

Simplified General Perturbations Number 4 (SGP4) has been the traditional algorithm for performing Orbit Determination (OD) onboard orbiting spacecraft. However, the recent rise of high-performance computers with low Size, Weight, and Power (SWAP) factors has provided the opportunity to use Special Perturbations (SP), a more accurate algorithm to perform onboard OD. This research evaluates the most efficient way to implement SP on NVIDIA’s Jetson TX series of integrated Graphical Processing Units (GPUs). An initial serial version was implemented on the Jetson TX1 and TX2's Central Processing Units (CPUs). The runtimes of the initial version are the benchmark that the runtimes …

Analysis Of Temperature And Humidity Effects On Horizontal Photovoltaic Panels, Corey J. Booker

Theses and Dissertations

The United States Air Force seeks to address power grid vulnerability and bolster energy resilience through the use of renewable energy sources. Air Force Institute of Technology engineers designed and manufactured control systems to monitor power production from the most widely-used silicon-based solar cells at 38 testing locations around the globe spanning the majority of climate types. Researchers conducted multivariate regression analysis to establish a statistical relationship between photovoltaic power output, ambient temperature, and humidity pertaining to monocrystalline and polycrystalline photovoltaic panels. Formulated models first characterized power output globally, then by specific climate type with general inaccuracy. Location-specific models are …

Evaluation Of Resiliency In A Wide-Area Backup Protection System Via Model Checking, Kolby H. Elliot

Theses and Dissertations

Modern civilization relies heavily on having access to reliable power sources. Recent history has shown that present day protection systems are not adequate. Numerous backup protection (BP) systems have been proposed to mitigate the impact of primary protection system failures. Many of these novel BP systems rely on autonomous agents communicating via wide-area networks. These systems are highly complex and their control logic is based on distributed computing. Model checking has been shown to be a powerful tool in analyzing the behavior of distributed systems. In this research the model checker SPIN is used to evaluate the resiliency of an …

Bandwidth Analysis Of A Tightly-Packed Crossed-Dipole Array For Satellite Communications, Lawrence J. Lee

Theses and Dissertations

A bandwidth analysis of a tightly-packed crossed-dipole array antenna is presented in this thesis. A parametric study is described which varies the element spacing in the array and the resulting change in the terminal impedances is reported. The increased mutual coupling seen by the elements as a result of smaller element spacings is shown to minimize the variation in the value of the elements terminal currents across a 0.3 GHz to 3.0 GHz frequency range. This small variation in current translates into a minimal variation in the terminal impedances for a fixed excitation voltage. This is shown to be an …

Influencing Effective Electrical Distribution Modernization Through Advanced Metering, Jared R. Erickson

Theses and Dissertations

In 2013, the Department of Defense (DoD) required its services to implement advanced metering for the purpose of reducing energy usage (Department of Defense, 2013). Additionally, the DoD has aimed to improve its ability to assure a continuous energy supply to all of its installations. This study investigated processes for applying advanced meters on Air Force bases to increase energy assurance. This study also identified strategies for using advanced meters to influence infrastructure funding. This was accomplished through the use of extensive advanced meter data. The data was analyzed for outages and a procedure was created to locate outages in …

Techniques For Low-Latency In Software-Defined Radio-Based Networks, Daniel D. Hart

Theses and Dissertations

Decreased budgets have pushed the United States Air Force towards using existing systems in new ways. The use of unmanned aerial vehicle swarms is one example of reuse of existing systems. One problem with the increased utilization of these swarms is the congestion of the electromagnetic spectrum. Software-defined or cognitive radios have been proposed as a basis for a potential robust communications solution. The present research aims to develop and test a genetic algorithm-based cognitive engine to begin looking at real-time engines that could be used in future swarms. Here, latency is the optimization objective of primary importance. In testing …

Preparation And Properties Of Nanocrystalline Nickel By Pulse Electrodeposition On Glassy Carbon, Ya-Li Zhang, Ming-Xian Zhang, Teng-Da Guo, Yan-Jie Zhao, Sheng-Xue Yu

Journal of Electrochemistry

Nanocrystalline nickel exhibits electrocatalytic activity for methanol. In this work, nanocrystalline nickel coating has been obtained by using the double pulse method on glassy carbon materials surface. The influence of pulse conditions on the grain size of nanocrystalline nicke was studied. The concentrations and compositions of the plating bath were  300 g·L^-1 NiSO₄·6H₂O,45 g·L^-1 NiCl₂·6H₂O,40 g·L^-1 H₃BO₃,5 g·L^-1 C₇H₅NO₃S,and 0.05 g·L^-1 C₁₂H₂₅NaO₄S. The optimal pulse process parameters including the average pulse …

Synthesis And Electrochemical Properties Of Nickel-Rich Cathode Material Lini0.6Co0.2Mn0.2O2 With High Initial Coulombic Efficiency, Xiao-Yun Guan, Chao-Yu Hong, Jian-Ping Zhu, Wei-Li Wang, Yi-Xiao Li, Yong Yang

Journal of Electrochemistry

Nickel-rich cathode materials LiNi_0.6Co_0.2Mn_0.2O₂(NCM622)were synthesized by a co-precipitation-solid state sintering method at different temperatures. The structure, morphology and electrochemical performance of the as-prepared materials were investigated by X-ray powder diffraction (XRD) /Rietveld refinement, scanning electron microscope (SEM) and electrochemical experiments. It is found that NCM622 calcined at 800 ℃ showed the lowest degree of cation disorder (~1.97%) with a high initial Coulombic effiency of 92.2% and the capacity retention of 81.4% after 100 cycles.

Intrinsic Kinetic Properties Of Ternary Material For Lithium Ion Batteries Assessed By Single Particle Microelectrode, Yi-Min Wei

Journal of Electrochemistry

Electrochemical performances such as capacity, rate, cycle and thermal stability of the nickel (Ni), cobalt (Co) and manganese (Mn) ternary cathode material, LiNi_xCo_yMn_zO₂ (x + y + z = 1), are significantly influenced by the proportion of Ni, Co, and Mn elements. To obtain higher specific capacity, LiNi_0.6Co_0.2Mn _0.2O₂ (NCM622) and LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) with high amounts of Ni element were employed for the lithium ion batteries. By now, many studies have been focusing on the thermal and cycling stabilities of …

Preparation And Electrocatalytic Activity Of Nitrogen-Doping Tungsten Carbide Catalyst, Pian-Pian Yang, Li-Zhen Huang, Ying-Ying Li, Mei-Qin Shi, Chun-An Ma

Journal of Electrochemistry

Tungsten carbide (WC) is a promising electrocatalyst, however, its electrocatalytic activity is far inferior to Pt and Pt-group metal. In this work, nitrogen-doping tungsten carbide (WN|WC) catalysts with a nanoplate morphology were prepared via the tungsten nitride (WN) as the precursor and sodium tungstate as the tungsten source. The SEM and TEM results indicated that carbon atoms entered into the WN lattice to form the hexagonal close packed WC phase. In this way, an atomic scale heterostructure involving the closely linked interfaces between WN and WC was created . The XRD data confirmed that the cubic crystal structure of WN …

Applications Of Electrospinning In Lithium-Air Batteries, Yue Fu, Jin Wang, Hai-Yang Yu, Jing-Hua Tian, Rui-Zhi Yang

Journal of Electrochemistry

Lithium-air batteries have received increasing attention as the “ultimate batteries” due to their extremely high theoretical capacity and environment friendly. However, there are still many obstacles hindering the wide applications of the lithium-air batteries owing to the limitations of large charge-discharge over-potentials, poor Columbic efficiency and cycling performance. Exploring of high-efficiency, low-cost and eco-friendly catalysts is one of the vital issues for lithium-air batteries. Meanwhile, electrospinning techniques have been under substantial developments due to its simple fabrication process, high efficiency and production. This paper reviews the recent progresses in fabrications of various novel catalysts for lithium-air batteries with electrospinning techniques, …

The 3d Stress-Tensor Bootstrap, Anatoly Dymarsky, Filip Kos, Petr Kravchuk, David Poland, David Simmons-Duffin

Physics and Astronomy Faculty Publications

We study the conformal bootstrap for 4-point functions of stress tensors in parity-preserving 3d CFTs. To set up the bootstrap equations, we analyze the constraints of conformal symmetry, permutation symmetry, and conservation on the stress-tensor 4-point function and identify a non-redundant set of crossing equations. Studying these equations numerically using semidefinite optimization, we compute bounds on the central charge as a function of the independent coefficient in the stress-tensor 3-point function. With no additional assumptions, these bounds numerically reproduce the conformal collider bounds and give a general lower bound on the central charge. We also study the effect of gaps …

Three Dimensional View Of Arbitrary Q Syk Models, Sumit R. Das, Aminik Ghosh, Antal Jevicki, Kenta Suzuki

Physics and Astronomy Faculty Publications

In [15] it was shown that the spectrum and bilocal propagator of SYK model with four fermion interactions can be realized as a three dimensional model in AdS₂ ×S¹/Z₂ with nontrivial boundary conditions in the additional dimension. In this paper we show that a similar picture holds for generalizations of the SYK model with q-fermion interactions. The 3D realization is now given on a space whose metric is conformal to AdS₂ × S¹/Z₂ and is subject to a non-trivial potential in addition to a delta function at the center of …

Preventing Crossover In Redox Flow Batteries Through Active Material Oligomerization, Susan A. Odom

Chemistry Faculty Publications

No abstract provided.

Universality Of Fast Quenches From The Conformal Perturbation Theory, Anatoly Dymarsky, Michael Smolkin

Physics and Astronomy Faculty Publications

We consider global quantum quenches, a protocol when a continuous field theoretic system in the ground state is driven by a homogeneous time-dependent external interaction. When the typical inverse time scale of the interaction is much larger than all relevant scales except for the UV-cutoff the system’s response exhibits universal scaling behavior. We provide both qualitative and quantitative explanations of this universality and argue that physics of the response during and shortly after the quench is governed by the conformal perturbation theory around the UV fixed point. We proceed to calculate the response of one and two-point correlation functions confirming …

Accurate Location Of Evolving Faults On Transmission Lines Using Sparse Wide Area Measurements, Xiangqing Jiao, Yuan Liao

Electrical and Computer Engineering Faculty Publications

In electric power systems, not all fault conditions remain unchanged during faults. An evolving fault has one characteristic initially and changes to a different condition subsequently. Locating evolving faults is challenging due to the change in fault type shortly after the fault initiation. This paper presents a new approach for estimating the locations of evolving faults on transmission lines. By using sparse wide area voltage measurements, this method is able to accurately locate evolving faults without requiring measurements from either end of the faulted line. There is no need to detect whether a fault is an evolving fault or not. …

Communication Based Control For Dc Microgrids, Mahmoud S. Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

Centralized communication-based control is one of the main methods that can be implemented to achieve autonomous advanced energy management capabilities in DC microgrids. However, its major limitation is the fact that communication bandwidth and computation resources are limited in practical applications. This can be often improved by avoiding redundant communications and complex computations. In this paper, an autonomous communication-based hybrid state/event driven control scheme is proposed. This control scheme is hierarchical and heuristic, such that on the primary control level, it encompasses state-driven local controllers, and on the secondary control level, an event-driven MG centralized controller (MGCC) is used. This …

Optimal Operation Of Integrated Microgrids, Abdullah Albaker

Electronic Theses and Dissertations

Microgrids' deployments are increasing and projected to increase even more in future due to the significant advantages that are provided by this technology for end-use customers. However, microgrids can be connected to each other to create integrated microgrids system, which can further promote the anticipated and desired benefits. An integrated operation of microgrids can potentially improve the local power system reliability and resilience, increase the individual microgrids' economic benefits, and promote further utilization of renewable energy resources. Integrating microgrids, to achieve a microgrid network or cluster, is expected be an essential application towards smarter power grids and a key operational …

Design Of Power Switched-Capacitor Converters And Their Performance Analysis In A Soft-Charging Operation, Ayoob Alateeq

Electronic Theses and Dissertations

Switched-capacitor (SC) converters have gained more interest due to their high power density and appropriateness for small circuit integration. Building a SC DC-to-DC converter with only capacitors and switches is the main reason to seek a higher power density achievement. However, the SC converters suffer dominant losses related to their capacitors and switches. These losses can be determined and optimized by calculating the converter's output impedance in its two asymptotic limits.

We proposed a high voltage gain and a very low output impedance power switched-capacitor converter (PSC) with a lower number of components compared to other step-up switched-capacitor topologies. The …

Optimal Planning Of Microgrid-Integrated Battery Energy Storage, Ibrahim S. Alsaidan

Electronic Theses and Dissertations

Battery energy storage (BES) is a core component in reliable, resilient, and cost-effective operation of microgrids. When appropriately sized, BES can provide the microgrid with both economic and technical benefits. Besides the BES size, it is found that there are mainly three planning parameters that impact the BES performance, including the BES integration configuration, technology, and depth of discharge.

In this dissertation, the impact of each one of these parameters on the microgrid-integrated BES planning problem is investigated. Three microgrid-integrated BES planning models are developed to individually find the optimal values for the aforementioned parameters. These three microgrid-integrated BES planning …

Energising Dairy Decisions, John Upton, Philip Shine, Michael Breen, Michael D. Murphy

Publications

A new tool developed by Teagasc researchers easily and quickly allows dairy farmers to see their energy usage and evaluate how renewable sources could decrease energy costs.

Pathology-Informed Approach In Vulnerability Assessment Methods, Polinpapilinho F. Katina, Adrian V. Gheorghe, Charles B. Keating

Engineering Management & Systems Engineering Faculty Publications

A system pathology is a circumstance, condition, or pattern that acts to limit system performance, or lessen system viability, such that the likelihood of a system achieving performance expectation is reduced. The idea of pathology has been described in multiple fields, including computer science, organizational studies, policy analysis, system-of-systems engineering, and systems engineering. However, there is scarcity of literature describing relationship between system pathology and vulnerability assessment. The aim of this study lies at the intersection of system pathology and vulnerability assessment in engineered systems. First, authors provide the state of the art review of literature on system pathology. Second, …

Robust Power Interface For Smart Grid With Renewable Energy Source-To-Grid Functionality, Bohyun Ahn

All Graduate Theses, Dissertations, and Other Capstone Projects

Many renewable energy companies design wind turbine generators, solar panels, or electrical car batteries with different specifications according to their management philosophy. And typical commercial power converters are not universally designed for all different types of renewable energy systems. Because of this lack of flexibility and interoperability, a universal and scalable smart grid power converter design is desirable. Designing a robust controlled bi-directional power converter is the motivation for this thesis as the first step to develop a more universal converter topology connecting renewable energy sources and the electrical smart-grid of the future.

Renewable energy such as wind or solar …

Design And Implementation Of Pv-Firming And Optimization Algorithms For Three-Port Microinverters, Mahmood Alharbi

Electronic Theses and Dissertations

With the demand increase for electricity, the ever-increasing awareness of environmental issues, coupled with rolling blackouts, the role of renewable energy generation is increasing along with the thirst for electricity and awareness of environmental issues. This dissertation proposes the design and implementation of PV-firming and optimization algorithms for three-port microinverters. Novel strategies are proposed in Chapters 3 and 4 for harvesting stable solar power in spite of intermittent solar irradiance. PV firming is implemented using a panel-level three-port grid-tied PV microinverter system instead of the traditional high-power energy storage and management system at the utility scale. The microinverter system consists …

Processing Of Cubic Stabilized Zirconia Electrolyte Membranes For Electrolyte-Supported Single Cell Solid Oxide Fuel Cells Using Tape Casting, Arturo Coronado Rodriguez

Honors Undergraduate Theses

Electrochemical conversion devices are a developing technology that prove to be a viable and more efficient alternative to current environmentally friendly generation devices. As such, constant research has been done in the last few decades to increase their applications and reliability. One of these systems, and the focus of this research, is the single cell Solid Oxide Fuel Cell (SOFC). These systems are a developing technology which main caveat is the need of high operating temperatures and costs. As such, most multidisciplinary research has been focused on researching materials and/or processes that help mitigate the costs or lower the operating …

Control Of Gas Metal Arc Welding Using Process Sensing And Laser Arc Stabilization For Additive Manufacturing, Dale Brush

Graduate Theses & Non-Theses

The goal of the present research was to bridge the gap between powder-based and wire-based additive manufacturing (AM) processes using gas metal arc welding (GMAW). Powder-based AM processes typically can produce components with high geometric resolution (small features), but at low deposition rates. Wire-based AM processes typically can produce components with low geometric resolution, but at high deposition rates. AM with GMAW is a wire-based AM process in the wire arc additive manufacturing (WAAM) category of AM. To bridge the gap between powder-based and wire-based AM processes, GMAW’s deposition rate has to be reduced, allowing small features to be built. …