Electrical and Electronics Commons^™

Design Optimization Of Llc Topology And Phase Skipping Control Of Three Phase Inverter For Pv Applications, Utsav Somani

Electronic Theses and Dissertations

The world is heading towards an energy crisis and desperate efforts are being made to find an alternative, reliable and clean source of energy. Solar Energy is one of the most clean and reliable source of renewable energy on earth. Conventionally, extraction of solar power for electricity generation was limited to PV farms, however lately Distributed Generation form of Solar Power has emerged in the form of residential and commercial Grid Tied Micro-Inverters. Grid Tied Micro-Inverters are costly when compared to their string type counterparts because one inverter module is required for every single or every two PV panels whereas …

Load Estimation For Electric Power Distribution Networks, Chiebuka Eyisi

Electronic Theses and Dissertations

In electric power distribution systems, the major determinant in electricity supply strategy is the quantity of demand. Customers need to be accurately represented using updated nodal load information as a requirement for efficient control and operation of the distribution network. In Distribution Load Estimation (DLE), two major categories of data are utilized: historical data and direct real-time measured data. In this thesis, a comprehensive survey on the state-of-the-art methods for estimating loads in distribution networks is presented. Then, a novel method for representing historical data in the form of Representative Load Curves (RLCs) for use in realtime DLE is also …

Time And Space Efficient Techniques For Facial Recognition, Waleed Alrasheed

Electronic Theses and Dissertations

In recent years, there has been an increasing interest in face recognition. As a result, many new facial recognition techniques have been introduced. Recent developments in the field of face recognition have led to an increase in the number of available face recognition commercial products. However, Face recognition techniques are currently constrained by three main factors: recognition accuracy, computational complexity, and storage requirements. The problem is that most of the current face recognition techniques succeed in improving one or two of these factors at the expense of the others. In this dissertation, four novel face recognition techniques that improve the …

Economic Challenges And Optimisation Of Ocean Energy Electrical Systems, Fergus Sharkey

Books/Book chapters

No abstract provided.

Crystal Growth, Characterization And Fabrication Of Cdznte-Based Nuclear Detectors, Ramesh Madhu Krishna

Theses and Dissertations

In today's world, nuclear radiation is seeing more and more use by humanity as time goes on. Nuclear power plants are being built to supply humanity's energy needs, nuclear medical imaging is becoming more popular for diagnosing cancer and other diseases, and control of weapons-grade nuclear materials is becoming more and more important for national security. All of these needs require high-performance nuclear radiation detectors which can accurately measure the type and amount of radiation being used. However, most current radiation detection materials available commercially require extensive cooling, or simply do not function adequately for high-energy gamma-ray emitting nuclear materials …

A Study On The Power Quality Of Dg Integrated Building Energy System In Virtual Environment, Shafiuzzaman K. Khadem, Ruth Kerrigan, Malabika Basu, Biswajit Basu

Conference papers

In this paper, the electrical energy demand of a typical residential building has been extracted from a Virtual Environment (VE) simulation. The extracted energy demand is generated by input load demand and hourly operating information. Based on the electrical energy demand for a typical day, a building integrated photovoltaic (PV) system is then simulated in MATLAB to extract the current/voltage disturbance information into the network. Outcome of this simulation shows the voltage/current waveform along with the disturbances at different locations in the building. The city of Dublin, Ireland has been chosen as a geographical location and VE-Pro software has been …

System Modeling And Optimization In Phase-Modulated Optical Fiber Communication Systems, Craig Huang

All Graduate Theses, Dissertations, and Other Capstone Projects

In this two-part study, the conclusions drawn from optimization of interferometer incoherent detection carried out by examining the effect of pre-emphasis within the electrical signal-driving path are examined first. This is an expansion upon a widespread industry standard as realized by the Oclaro group. System performance in tight optical filtering conditions can be improved with concurrent adjustments to the level of pre- emphasis and breadth of the delay-line interferometer free-spectral range. In the second study, we implement a dual-polarization quadrature phase-shift keyed modulation format with a digital signal processing block based upon the constant modulus algorithm realized via a feed-forward …

Community Microgrid Based On Micro-Wind Generation System, Lubna Mariam, Malabika Basu, Michael Conlon

Conference papers

Penetration of renewable energy sources (such as solar/wind) are being explored mostly as micro power generation (μGen) or mega power plant system. In recent years, emphasis has been given on Microgrid (μGrid) systems because of their few advantages over μGen systems in terms of power quality, stability, reliability, economics etc. But the commercial installation of the μGrid system is not yet progressing significantly. This paper presents the techno-economic aspects of μGen and μGrid systems towards the development of grid connected community based μGrid (C-μGrid) system. Emphasis has been given to identify the benefits of the μGrid over the μGen system. …

A New Placement And Integration Method Of Upqc To Improve The Power Quality In Dg Network, Shafiuzzaman K. Khadem, Malabika Basu, Michael Conlon

Conference papers

A new proposal for the placement and integration of UPQC in DG connected microgrid/micro generation (μG) system has been presented here. DG converters (with storage), the load and shunt part of the UPQC will be placed at or after the PCC. The series part of the UPQC will be placed before the PCC and in series with the grid. DC link can be connected to the storage system also. Hence, it is termed UPQCμ_G. The advantages of the proposed UPQCμ_G over the normal UPQC are to compensate voltage interruptions in addition to voltage sags / swells, harmonic …

Reduction Of Circulating Current Flow In Parallel Operation Of Apf Based On Hysteresis Current Control, Shafiuzzaman K. Khadem, Malabika Basu, Michael Conlon

Conference papers

Capacity enhancement and operation flexibility are two of the important limitations of the centralized Shunt Active Power Filter (APF_sh) unit. This can be overcome by multiple and parallel APF_sh units (in distributed mode) with a common DC link. In that case, a circulating current (CC) can flow. In the case of a hysteresis current controller based multiple APF_sh units in load sharing mode, this CC control is not yet achieved. One of the difficulties of this CC flow control or reduction is the variable switching frequency of the APF_sh units. In this paper, the model …

Reduced-Order Modeling Using Orthogonal And Bi-Orthogonal Wavelet Transforms, Miguel Hernandez Iv

Open Access Theses & Dissertations

It is well known that model reduction methods borrow techniques typically found in data compression, and current state-of-the-art techniques for data compression are based on the wavelet transform. Given these facts, it is surprising that model reduction using wavelets has not received much attention and has not been adequately addressed in the literature. This research seeks to determine if wavelets can be used for model reduction and if wavelet model reduction is a viable alternative to existing model reduction methods.

In this work we propose a novel method for model reduction using wavelets. Specifically, we introduce techniques for deriving wavelet …

Structural, Optical And Electrical Properties Of Yttrium-Doped Hafnium Oxide Nanocrystalline Thin Films, Abhilash Kongu

Open Access Theses & Dissertations

Hafnium oxide (HfO2) has emerged as the most promising high-k dielectric for Metal-Oxide-Semiconductor (MOS) devices and has been highlighted as the most suitable dielectric materials to replace silicon oxide because of its comprehensive performance. In the present research, yttrium-doped HfO2 (YDH) thin films were fabricated using RF magnetron sputter deposition onto Si (100) and quartz with a variable thickness. Cross-sectional scanning electron microscopy coupled with Filmetrics revealed that film thickness values range from 700 A° to 7500 A°. Electrical properties such as AC Resistivity and current-voltage (I-V) characteristics of YDH films were studied. YDH films that were relatively thin (<1500 A°) crystallized in monoclinic phase while thicker films crystallized in cubic phase. The band gap (Eg) of the films was calculated from the optical measurements. The band gap was found to be ∼5.60 eV for monoclinic while it is ∼6.05 eV for cubic phase of YDH films. Frequency dependence of the electrical resistivity (ρac) and the total conductivity of the films were measured. Resistivity decreased (by three orders of magnitude) with increasing frequency from 100 Hz to 1 MHz, attributed due to the hopping mechanism in YDH films. Whereas, while ρac∼1Ω-m at low frequencies (100 Hz), it decreased to ∼ 104 Ω-cm at higher frequencies (1 MHz). Aluminum (Al) metal electrodes were deposited to fabricate a thin film capacitor with YDH layer as dielectric film thereby employing Al-YDH-Si capacitor structure. The results indicate that the capacitance of the films decrease with increasing film thickness. A detailed analysis of the electrical characteristics of YDH films is presented.

Properties Of Peg, Ppg And Their Copolymers Influence On The Gap-Fill Characteristics Of Damascene Interconnects, Kevin Ryan

Legacy Theses & Dissertations (2009 - 2024)

A laboratory scale plating cell was built that provided reproducible bottom-up fill results for the electrochemical deposition of copper in damascene features. Several techniques used in the full wafer plating tool were incorporated into the setup to accurately control the process conditions. These techniques included but were not limited to a voltage controlled `hot-entry' step, a custom coupon holder to allow sample rotation, a secondary thief electrode and an automatic entry system. The results of qualification experiments are presented to demonstrate that precise control was realized along with repeatable partial fill plating results. The qualified setup was then used to …

Adaptive Encryption Techniques In Wireless Communication Channels With Tradeoffs Between Communication Reliability And Security, Walid Al Zibideh

Electronic Theses and Dissertations

Encryption is a vital process to ensure the confidentiality of the information transmitted over an insecure wireless channel. However, the nature of the wireless channel tends to deteriorate because of noise, interference and fading. Therefore, a symmetrically encrypted transmitted signal will be received with some amount of error. Consequently, due to the strict avalanche criterion (sac), this error propagates during the decryption process, resulting in half the bits (on average) after decryption to be in error. In order to alleviate this amount of error, smart coding techniques and/or new encryption algorithms that take into account the nature of wireless channels …

Asynchronous Logic Design With Increased Fault Tolerance And Optimized For Subthreshold Operation, Ivan Santos

Open Access Theses & Dissertations

Synchronization has always been an essential feature in electronic circuits, in which functionality is achieved by an appropriate flow of data with respect to time. An ideal concept of logic design would require every operation to happen instantly; however, the application of this principle to electronics is governed by the laws of physics, which influence the time to execute a process. In fact, the speed at which a microprocessor can perform logic operations is determined by the time that charging and discharging capacitive loads requires, and the time that electric signals spend when traveling through the circuitry. Consequently, the variation …

Assessment And Evaluation Of The Dynamic Behavior Of Muscles With Special Reference To Subjects With Diabetes Mellitus, Jorge Garza-Ulloa

Open Access Theses & Dissertations

Diabetes mellitus (simply diabetes) is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced. Each year, the costs of diabetes rise. Diabetes and its complications cost our national economy. Two new methods are proposed to measure the diabetes implications in the muscles of lower body: Muscle energy expenditure analysis based on the detection of muscle transition-to-fatigue, and Natural Fuzzy logic method for differential analysis in muscle/joint. Then the results are compared with the traditional method …

Modeling And Simulation Of All-Electric Aircraft Power Generation And Actuation, David Woodburn

Electronic Theses and Dissertations

Modern aircraft, military and commercial, rely extensively on hydraulic systems. However, there is great interest in the avionics community to replace hydraulic systems with electric systems. There are physical challenges to replacing hydraulic actuators with electromechanical actuators (EMAs), especially for flight control surface actuation. These include dynamic heat generation and power management. Simulation is seen as a powerful tool in making the transition to all-electric aircraft by predicting the dynamic heat generated and the power flow in the EMA. Chapter 2 of this dissertation describes the nonlinear, lumped-element, integrated modeling of a permanent magnet (PM) motor used in an EMA. …

Analysis And Design Optimization Of Multiphase Converter, Kejiu Zhang

Electronic Theses and Dissertations

Future microprocessors pose many challenges to the power conversion techniques. Multiphase synchronous buck converters have been widely used in high current low voltage microprocessor application. Design optimization needs to be carefully carried out with pushing the envelope specification and ever increasing concentration towards power saving features. In this work, attention has been focused on dynamic aspects of multiphase synchronous buck design. The power related issues and optimizations have been comprehensively investigated in this paper. In the first chapter, multiphase DC-DC conversion is presented with background application. Adaptive voltage positioning and various nonlinear control schemes are evaluated. Design optimization are presented …

Rf Power Amplifier And Oscillator Design For Reliability And Variability, Shuyu Chen

Electronic Theses and Dissertations

CMOS RF circuit design has been an ever-lasting research field. It gained so much attention since RF circuits have high mobility and wide band efficiency, while CMOS technology has the advantage of low cost and better capability of integration. At the same time, IC circuits never stopped scaling down for the recent many decades. Reliability issues with RF circuits have become more and more severe with device scaling down: reliability effects such as gate oxide break down, hot carrier injection, negative bias temperature instability, have been amplified as the device size shrinks. Process variability issues also become more predominant as …

Investigation On Electrical Properties Of Rf Sputtered Deposited Bcn Thin Films, Adithya Prakash

Electronic Theses and Dissertations

The ever increasing advancements in semiconductor technology and continuous scaling of CMOS devices mandate the need for new dielectric materials with low-k values. The interconnect delay can be reduced not only by the resistance of the conductor but also by decreasing the capacitance of dielectric layer. Also cross-talk is a major issue faced by semiconductor industry due to high value of k of the inter-dielectric layer (IDL) in a multilevel wiring scheme in Si ultra large scale integrated circuit (ULSI) devices. In order to reduce the time delay, it is necessary to introduce a wiring metal with low resistivity and …

A Novel Nonlinear Mason Model And Nonlinear Distortion Characterization For Surface Acoustic Wave Duplexers, Li Chen

Electronic Theses and Dissertations

Surface acoustic wave (SAW) technology has been in use for well over one century. In the last few decades, due to its low cost and high performance, this technology has been widely adopted in modern wireless communication systems, to build filtering devices at radio frequency (RF). SAW filters and duplexers can be virtually found inside every mobile handset. SAW devices are traditionally recognized as passive devices with high linear signal processing behavior. However, recent deployments of third generation (3G) and fourth generation (4G) mobile networks require the handsets to handle an increasing number of frequency bands with more complex modulation …

Polymer Optical Fibers For Luminescent Solar Concentration, Esmaeil Banaei

Electronic Theses and Dissertations

Luminescent solar concentrators (LSC’s) are promising candidates for reducing the cost of solar power generation. Conventional LSC’s are slab waveguides coated or doped with luminescence materials for absorption and guiding of light to the slab edges in order to convert optical energy into electricity via attached photovoltaic (PV) cells. Exploiting the advantages of optical fiber production, a fiber LSC (FLSC) is presented in this thesis, in which the waveguide is a polymeric optical fiber. A hybrid fiber structure is proposed for an efficient two-stage concentration of incident light, first into a small doped core using a cylindrical micro-lens that extends …

Transient And Distributed Algorithms To Improve Islanding Detection Capability Of Inverter Based Distributed Generation, Mohamed Al Hosani

Electronic Theses and Dissertations

Recently, a lot of research work has been dedicated toward enhancing performance, reliability and integrity of distributed energy resources that are integrated into distribution networks. The problem of islanding detection and islanding prevention (i.e. anti-islanding) has stimulated a lot of research due to its role in severely compromising the safety of working personnel and resulting in equipment damages. Various Islanding Detection Methods (IDMs) have been developed within the last ten years in anticipation of the tremendous increase in the penetration of Distributed Generation (DG) in distribution system. This work proposes new IDMs that rely on transient and distributed behaviors to …

Distributed Extremum Seeking And Cooperative Control For Mobile Cooperative Communication Systems, Said Alabri

Electronic Theses and Dissertations

In this thesis, a distributed extremum seeking and cooperative control algorithm is designed for mobile agents to disperse themselves optimally in maintaining communication quality and maximizing their coverage. The networked mobile agents locally form a virtual multiple-input multipleoutput (MIMO) communication system, and they cooperatively communicate among them by using the decode and forward cooperative communication technique. The outage probability is used as the measure of communication quality, and it can be estimated real-time. A general performance index balancing outage probability and spatial dispersion is chosen for the overall system. The extremum seeking control approach is used to estimate and optimize …

Holistic Representations For Activities And Crowd Behaviors, Berkan Solmaz

Electronic Theses and Dissertations

In this dissertation, we address the problem of analyzing the activities of people in a variety of scenarios, this is commonly encountered in vision applications. The overarching goal is to devise new representations for the activities, in settings where individuals or a number of people may take a part in specific activities. Different types of activities can be performed by either an individual at the fine level or by several people constituting a crowd at the coarse level. We take into account the domain specific information for modeling these activities. The summary of the proposed solutions is presented in the …

Multi-Physics Model Of Key Components In High Efficiency Vehicle Drive, Shao Hua Lin

Electronic Theses and Dissertations

Hybrid Electric Vehicles (HEVs) and Electric Vehicles (EVs) are crucial technologies for the automotive industry to meet society’s demands for cleaner, more energy efficient transportation. Meeting the need to provide power which sustains HEVs and EVs is an immediate area of concern that research and development within the automotive community must address. Electric batteries and electrical motors are the key components in HEV and EV power generation and transmission, and their performance plays very important role in the overall performance of the modern high efficiency vehicles. Therefore, in this dissertation, we are motivated to study the electric batteries, interior permanent …

Monolithically Integrated Broadly Tunable Light Emitters Based On Selectively Intermixed Quantum Wells, Abdullah Zakariya

Electronic Theses and Dissertations

A monolithically integrated broadly tunable MQW laser that utilizes a combined impurity-free vacancy disordering (IFVD) of quantum wells and optical beam steering techniques is proposed and investigated experimentally. The device consists of a beam-steering section and an optical amplifier section fabricated on a GaAs/AlGaAs quantum well (QW) p-i-n heterostructure. The beam steering section forms a reconfigurable optical waveguide that can be moved laterally by applying separately controlled electrical currents to two parallel contact stripes. The active core of the gain section is divided in into selectively intermixed regions. The selective intermixing of the QW in the gain section results in …

Microstrip Patch Electrically Steerable Parasitic Array Radiators, Justin Luther

Electronic Theses and Dissertations

This dissertation explores the expansion of the Electrically Steerable Parasitic Array Radiator (ESPAR) technology to arrays using microstrip patch elements. Scanning arrays of two and three closely-coupled rectangular patch elements are presented, which incorporate no phase shifters. These arrays achieve directive radiation patterns and scanning of up to 26° with maintained impedance match. The scanning is effected by tunable reactive loads which are used to control the mutual coupling between the elements, as well as additional loads which compensate to maintain the appropriate resonant frequency. The design incorporates theoretical analysis of the system of coupled antennas with full-wave simulation. A …

Optimization And Design Of Photovoltaic Micro-Inverter, Qian Zhang

Electronic Theses and Dissertations

To relieve energy shortage and environmental pollution issues, renewable energy, especially PV energy has developed rapidly in the last decade. The micro-inverter systems, with advantages in dedicated PV power harvest, flexible system size, simple installation, and enhanced safety characteristics are the future development trend of the PV power generation systems. The double-stage structure which can realize high efficiency with nice regulated sinusoidal waveforms is the mainstream for the micro-inverter. This thesis studied a double stage micro-inverter system. Considering the intermittent nature of PV power, a PFC was analyzed to provide additional electrical power to the system. When the solar power …

Ultrafast Laser Material Processing For Photonic Applications, Mark Ramme

Electronic Theses and Dissertations

Femtosecond Laser Direct Writing (FLDW) is a viable technique for producing photonic devices in bulk materials. This novel manufacturing technique is versatile due to its full 3D fabrication capability. Typically, the only requirement for this process is that the base material must be transparent to the laser wavelength. The modification process itself is based on non-linear energy absorption of laser light within the focal volume of the incident beam. This thesis addresses the feasibility of this technique for introducing photonic structures into novel dielectric materials. Additionally, this work provides a deeper understanding of the lightmatter interaction mechanism occurring at high …