Electrical and Computer Engineering Commons^™

Modeling And Control Of The Ugv Argo J5 With A Custom-Built Landing Platform, Mohammed Aldaoseri Alghanim

Electronic Theses and Dissertations

This thesis aims to develop a detailed dynamic model and implement several navigation controllers for path tracking and dynamic self-leveling of the Argo J5 Unmanned Ground Vehicle (UGV) with a custom-built landing platform. The overall model is derived by combining the Argo J5 driveline system with the wheelsterrain interaction (using terramechanics theory and mobile robot kinetics), while the landing platform model follows the Euler-Lagrange formulation. Different controllers are, then, derived, implemented to demonstrate: i.) self-leveling accuracy of the landing platform, ii.) trajectory tracking capabilities of the Argo J5 when moving in uneven terrains. The novelty of the Argo J5 model …

Highly Efficient Gan-Based Single-Phase Transformer-Less Pv Grid-Tied Inverter, Khaled Alatawi

Electronic Theses and Dissertations

Growing energy demand and environmental concerns have led to an increased interest in renewable energy resources to provide a sustainable and low carbon emission energy supply. Among these renewable energy resources, photovoltaic (PV) systems have been the focus of many scientific researchers. The most vital component of a PV system that needs to be improved is the power converter. Grid-tied transformer-less inverters have gained a lot of interest in recent years because of their higher efficiency, reduced volume and lower cost compared to traditional line transformer inverters.

This dissertation discusses single-phase transformer-less inverter challenges and provides solutions that could lead …

Design And Evaluation Of High Efficiency Power Converters Using Wide-Bandgap Devices For Pv Systems, Fahad Almasoudi

Electronic Theses and Dissertations

The shortage of fossil resources and the need for power generation options that produce little or no environmental pollution drives and motivates the research on renewable energy resources. Power electronics play an important role in maximizing the utilization of energy generation from renewable energy resources. One major renewable energy source is photovoltaics (PV), which comprises half of all recently installed renewable power generation in the world. For a grid-connected system, two power stages are needed to utilize the power generated from the PV source. In the first stage, a DCDC converter is used to extract the maximum power from the …

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 …

Study Of Optical Ofdm System For Wireless Lan Applications, Salih Mohamed S. Kenshil

Electronic Theses and Dissertations

The advantages of optical fiber make it possible to extend the data rate transmission and propagation distance. Orthogonal frequency division multiplexing (OFDM) as a multicarrier technique (MC) is used in hybrid optical-wireless system designs because it has the best spectral efficiency to radio frequency (RF) interference and lower multipath distortion. In this dissertation, a study and evaluation of optical OFDM based wireless local area network (W-LAN) systems are presented. The baseband of the OFDM signal is fully transmitted and up-converted to a radio frequency signal. Also, to reduce system costs, simple base stations (BSs) are interconnected to a central office …

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 …

Robust Distributed Stabilization Of Interconnected Multiagent Systems, Vahid Rezaei

Electronic Theses and Dissertations

Many large-scale systems can be modeled as groups of individual dynamics, e.g., multi-vehicle systems, as well as interconnected multiagent systems, power systems and biological networks as a few examples. Due to the high-dimension and complexity in configuration of these infrastructures, only a few internal variables of each agent might be measurable and the exact knowledge of the model might be unavailable for the control design purpose. The collective objectives may range from consensus to decoupling, stabilization, reference tracking, and global performance guarantees. Depending on the objectives, the designer may choose agent-level low-dimension or multiagent system-level high-dimension approaches to develop distributed …

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 …

Hosting Capacity Optimization In Modern Distribution Grids, Mansoor T. Alturki

Electronic Theses and Dissertations

The availability of distributed renewable energy resources and the anticipated increase in new types of loads are changing the way electricity is being produced and supplied to consumers. This shift is moving away from a network delivering power solely from centralized power plants towards a decentralized network which supplements its power production by incorporating local distributed generators (DGs). However, the increased integration of DGs into existing distribution networks is impacting their behavior in terms of voltage profile, reliability, and power quality. To determine the maximum amount of DG that distribution grids can accommodate the concept of hosting capacity is introduced. …

Steady-State And Small-Signal Modeling Of A-Source Converter, Agasthya Ayachit

Browse all Theses and Dissertations

As the trend towards vehicle electrification, renewable energy, smart systems is increasing, the key enabling technology such as power electronics are becoming ever more important. Power electronics is the vital component of many applications in automotive, computer, data-centers, medical, aerospace, communication, green-energy, and manufacturing sectors. Major advancements in high efficiency, high power density, high voltage conversion ratio, and fast dynamic response power-electronic converters is evident both in research and industry, particularly at the topology level. A major contribution of this dissertation is the analysis, design, development, and dynamic modeling of a novel impedance-source topology termed as A-source converter, which potentially …

Characterization And Design Of Voltage-Mode Controlled Full-Bridge Dc/Dc Converter With Current Limit, Nathaniel R. Smith

Browse all Theses and Dissertations

Advancements in Direct Current (DC) electrical power systems have enabled new functionality in many, varied applications. Discrete power semiconductor devices are increasing in efficiency, switching frequency, and power density, resulting in greater usage of DC power management and distribution methods, including DC/DC conversion. DC distribution lacks inherent capability to safely and effectively break fault current, particularly in mobile solutions, where larger and slower electromechanical switching devices are not optimal or feasible. One solution is to design a low-energy breaking point into a switching power supply. Simpler converter designs, with a lower number of switching devices, have been modeled and can …

Optimized Trajectory Generation For Car-Like Robots On A Closed Loop Track, Tyler Friedl

Electronic Theses and Dissertations

This thesis presents a method for generating an optimized path through a given track. The path is generated by choosing waypoints throughout the track then iteratively optimizing the position of these waypoints. The waypoints are then connected by optimized paths represented by curvature polynomials. The end result is a path through the track represented as a spline of curvature polynomials. This method is applied to multiple simulated tracks and the results are presented. By generating and representing the paths in the continuous domain, the method has improved computational efficiency from many of the discrete methods used to generate an optimal …

Data-Centric Situational Awareness And Management In Intelligent Power Systems, Xiaoxiao Dai

Electronic Theses and Dissertations

The rapid development of technology and society has made the current power system a much more complicated system than ever. The request for big data based situation awareness and management becomes urgent today. In this dissertation, to respond to the grand challenge, two data-centric power system situation awareness and management approaches are proposed to address the security problems in the transmission/distribution grids and social benefits augmentation problem at the distribution-customer lever, respectively.

To address the security problem in the transmission/distribution grids utilizing big data, the first approach provides a fault analysis solution based on characterization and analytics of the synchrophasor …

Optimal Capacity And Energy Efficiency Of Massive Mimo Systems, Ahmed Alshammari

Electronic Theses and Dissertations

A lot of effort has been made during the last two decades to study and apply the concepts of MIMO technology in most of the wireless standards. Therefore, a huge improvement in the performance of wireless communications has been made. However, Demand for wireless services has exponentially increased during the past ten years. Hence, high throughput is very important for all users to get the best experience with the offered services. This creates many technical challenges that are difficult to handle with the existing technology. Therefore, massive multiple input multiple output (massive MIMO) is a new technology that has been …

Design And Operation Of Distribution Markets, Sina Parhizi

Electronic Theses and Dissertations

The growing penetration of distributed prosumers especially microgrids poses new challenges to the operation of wholesale markets and distribution power systems. Price spikes and higher uncertainty are among these consequences. Distribution markets are envisioned as a remedy to streamline integration of distributed resources and microgrids in the electricity market. This dissertation offers an analytical formulation of electricity markets in the distribution level, considering various prevailing aspects of the market operation problem.

The prevailing challenges in regards to integration of microgrids in the electricity markets are illustrated first, and the distribution market operator (DMO) construct is outlined. The day-ahead scheduling of …

Risk Optimized Microgrid Resource Management, Thomas William Cashel Iii

Electronic Theses and Dissertations

This thesis proposes a risk based price adjustment method for a day ahead scheduling of a distribution side tiered community microgrid within a transactive energy style market. The system is organized into a master controller and local controller confïguration to simulate behind meter activity that is not visible to the master controller. Conditional value at risk is used to asses the risk of distributed energy resources in each local controller and the risk for each local controller is aggregated providing each local controller a single risk value. Each device's, or local controller's, risk value is used to adjust the price …

Effect Of Exponential Correlation Model On Spectral And Energy Efficiency For Massive Mimo Systems, Saleh Albdran

Electronic Theses and Dissertations

During the past few years, the number of wireless devices has been increasing rapidly. Wireless networks are serving and connecting billions of wireless devices where these devices are demanding higher data rate and lower latency to be able to support voice, video and gaming applications. Moreover, the consumed energy by the wireless systems will be increasing. Hence, the Fifth generation (5G) wireless networks needs to provide higher data rate, serve larger number of users simultaneously and be more energy efficient. One of the promising technologies that can meet the above requirements is Massive Multiple Input Multiple Output (MIMO). The main …

Simultaneous Behavior Onset Detection And Task Classification For Patients With Parkinson Disease Using Subthalamic Nucleus Local Field Potentials, Nazanin Zaker Habibabadi

Electronic Theses and Dissertations

This thesis aims to develop of methods for behavior onset detection of patients with Parkinson's disease (PD), as well as to investigate the models for classification of different behavioral tasks performed by PD patient. The detection is based on recorded Local Field Potentials (LFP) of the Subthalamic nucleus (STN), captured through Deep Brain Stimulation (DBS) process.

One main part of this work is dedicated to the research of various properties and features of the STN LFP signals of several patients' behavior conditions. Features based on temporal and time-frequency analysis of the signals are developed and implemented. Evaluation and comparison of …

Synthesis And Characterization Of Kesterite Cu2znsns4 (Czts) Thin Films For Solar Cell Application, Mohamed M.A. Abusnina

Electronic Theses and Dissertations

The quaternary compound Cu₂ZnSnS₄ (CZTS) gained considerable attention in the last decade due to its potential as an active-layer semiconductor for low-cost thin-film solar cells. The material is composed of nontoxic and Earth-abundant constituents, has optical properties suitable for photovoltaic application, and can be synthesized using a wide variety of methods.

Polycrystalline CZTS was grown in this work using vacuum-based deposition to first deposit metal films (precursors) of Cu, Zn, and Sn. In a subsequent step, the precursors underwent an annealing treatment in sulfur vapor environment (sulfurization) to form CZTS. Using sputtering, a physical vapor deposition (PVD) …

A Reserve-Based Method For Mitigating The Impact Of Renewable Energy, Ibrahim Krad

Electronic Theses and Dissertations

The fundamental operating paradigm of today's power systems is undergoing a significant shift. This is partially motivated by the increased desire for incorporating variable renewable energy resources into generation portfolios. While these generating technologies offer clean energy at zero marginal cost, i.e. no fuel costs, they also offer unique operating challenges for system operators. Perhaps the biggest operating challenge these resources introduce is accommodating their intermittent fuel source availability. For this reason, these generators increase the system-wide variability and uncertainty. As a result, system operators are revisiting traditional operating strategies to more efficiently incorporate these generation resources to maximize the …

A Comprehensive Methodology For Design Of A Circulation Control Small-Scale Unmanned Aircraft, Konstantinos Kanistras

Electronic Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) have become increasingly prevalent and important for a wide spectrum of civilian and military operations. When focusing on small-scale fixed-wing UAVs, payload, power and energy requirements limit considerably their utilization and flexibility allowing them to complete only those specific missions they are designed for. Circulation Control (CC) is an active flow control method used to produce increased lift over the traditional systems (flaps, slats, etc...) currently in use. This dissertation focuses on the foundations of a comprehensive methodology from design to implementation and experimental testing of Coanda-based Circulation Control Wings (CCW) for unmanned aircraft. The …

System Frequency Support Of Permanent Magnet Synchronous Generator-Based Wind Power Plant, Ziping Wu

Electronic Theses and Dissertations

With ever-increasing penetration of wind power into modern electric grids all over the world, a trending replacement of conventional synchronous generators by large wind power plants will likely result in the poor overall frequency regulation performance. On the other hand, permanent magnet synchronous generator wind Turbine System (PMSG-WTG) with full power back to back converters tends to become one of the most promising wind turbine technologies thanks to various advantages. It possesses a significant amount of kinetic energy stored in the rotating mass of turbine blades, which can be utilized to enhance the total inertia of power system. Additionally, the …

Nonreciprocal Magnetostatic Surface Wave In Thin Ferromagnetic Film, Kumar Vishal

Browse all Theses and Dissertations

Interest in the nonreciprocal property of waves inside the magnetic material starts with its current advancement in the field of passive devices. In current technology passive devices without magnetic cores are realized on a silicon chip, usually these devices are lossy and bigger in size. Passive devices constructed with magnetic core material such as isolators, circulators, phase shifters, and gyrators; gives us the chance to minimize such losses. Nonreciprocity in magnetic material is due to the anisotropic property of permeability, it is complex in nature and represent in 3×3 matrix form. We can control the wave flow inside the nonreciprocal …

Unmanned Aircraft Systems: Air-Ground Channel Characterization For Future Applications, David W. Matolak, Ruoyu Sun

Faculty Publications

Unmanned aircraft systems (UASs) are being used increasingly worldwide. These systems will operate in conditions that differ from conventional piloted aircraft, and this implies that the airground (AG) channel for UASs can differ significantly from the traditional, simple, AG channel models. After providing some background and motivation, we describe the AG channel features and our efforts in measuring and modeling the AG channel. Some example measurement and model results-for the path loss and the Ricean K-factor-are provided to illustrate some of the interesting AG channel characteristics that are still being investigated.

Electroencephalogram Based Causality Graph Analysis In Behavior Tasks Of Parkinson’S Disease Patients, Abdulaziz Saleh Almalaq

Electronic Theses and Dissertations

Electroencephalographic (EEG) signals of the human brains represent electrical activities for a number of channels recorded over a the scalp. The main purpose of this thesis is to investigate the interactions and causality of different parts of a brain using EEG signals recorded during a performance subjects of verbal fluency tasks. Subjects who have Parkinson's Disease (PD) have difficulties with mental tasks, such as switching between one behavior task and another. The behavior tasks include phonemic fluency, semantic fluency, category semantic fluency and reading fluency. This method uses verbal generation skills, activating different Broca's areas of the Brodmann's areas (BA44 …

Particle Swarm Optimization Based Reactive Power Dispatch For Power Networks With Distributed Generation, Xiao Kou

Electronic Theses and Dissertations

Reactive power is critical to the operation of the power networks on both safety aspects and economic aspects. Unreasonable distribution of the reactive power would severely affect the power quality of the power networks and increases the transmission loss. Currently, the most economical and practical approach to minimizing the real power loss remains using reactive power dispatch method.

Reactive power dispatch problem is nonlinear and has both equality constraints and inequality constraints. In this thesis, PSO algorithm and MATPOWER 5.1 toolbox are applied to solve the reactive power dispatch problem. PSO is a global optimization technique that is equipped with …

Locational Marginal Pricing At The Power Distribution Level, Jun Hao

Electronic Theses and Dissertations

During the development of smart grid at distribution level, the realization of real-time nodal pricing is one of the key challenges. This thesis proposes a novel methodology of locational marginal pricing at power distribution level. The nodal pricing mechanism is implemented utilizing both Direct Current Optimal Power Flow and Alternate Current Optimal Power Flow. The University of Denver campus power grid is used to develop the simulation test bed of the distribution level power system. In order to realize our approach, the first step is to extract the network topology from the DU campus grid utility map. The network topology …

Islanded Wind Energy Management System Based On Neural Networks, Ziqiao Liu

Electronic Theses and Dissertations

Wind power, as the main renewable energy source, is increasingly deployed and connected into electrical networks thanks to the development of wind energy conversion technologies. This dissertation is focusing on research related to wind power system include grid-connected/islanded wind power systems operation and control design, wind power quality, wind power prediction technologies, and its applications in microgrids. The doubly fed induction generator (DFIG) wind turbine is popular in the wind industry and thus has been researched in this Dissertation. In order to investigate reasons of harmonic generation in wind power systems, a DFIG wind turbine is modeled by using general …

Towards Closed-Loop Deep Brain Stimulation: Behavior Recognition From Human Stn, Soroush Niketeghad

Electronic Theses and Dissertations

Deep brain stimulation (DBS) provides significant therapeutic benefit for movement disorders such as Parkinson’s disease (PD). Current DBS devices lack real-time feedback (thus are open loop) and stimulation parameters are adjusted during scheduled visits with a clinician. A closed-loop DBS system may reduce power consumption and side effects by adjusting stimulation parameters based on patient’s behavior. Thus behavior detection is a major step in designing such systems. Various physiological signals can be used to recognize the behaviors. Subthalamic Nucleus (STN) Local field Potential (LFP) is a great candidate signal for the neural feedback, because it can be recorded from the …

Steady-State Analysis Of Pwm Z-Bridge Source Dc-Dc Converter, Lokesh Kathi

Browse all Theses and Dissertations

A PWM Z-bridge source dc-dc converter has a potential to play a prominent role in renewable energy applications, as it provides boosted and regulated output voltage and also behaves as an intermediate buffer between the source and the load. A complete circuit analysis of the Z-bridge source converter is needed to understand the operation of this converter. Steady-state analysis of pulse-width modulated (PWM) Z-bridge source dc-dc converter operating in continuous conduction mode (CCM) is given. Expressions describing waveforms of voltages across and currents through the all components of the PWM Z-bridge source dc-dc converter to operate in steady-state condition are …