Digital Commons Network^™

Studies Of Uncertainties In Smart Grid: Wind Power Generation And Wide-Area Communication, Can Huang

Doctoral Dissertations

This research work investigates the uncertainties in Smart Grid, with special focus on the uncertain wind power generation in wind energy conversion systems (WECSs) and the uncertain wide-area communication in wide-area measurement systems (WAMSs).

For the uncertain wind power generation in WECSs, a new wind speed modeling method and an improved WECS control method are proposed, respectively. The modeling method considers the spatial and temporal distributions of wind speed disturbances and deploys a box uncertain set in wind speed models, which is more realistic for practicing engineers. The control method takes maximum power point tracking, wind speed forecasting, and wind …

Design, Control And Protection Of Modular Multilevel Converter (Mmc)-Based Multi-Terminal Hvdc System, Yalong Li

Doctoral Dissertations

Even though today’s transmission grids are predominantly based on the high voltage alternating current (HVAC) scheme, interests on high voltage direct current (HVDC) are growing rapidly during the past decade, due to the increased penetration of remote renewable energy. Voltage source converter (VSC) type is preferred over the traditional line-commutated converter (LCC) for this application, due to the advantages like smaller station footprint and no need for strong interfacing ac grid. As the state-of-the-art VSC topology, modular multilevel converter (MMC) is mostly considered. Most renewable energy sources, such as wind and solar, is usually sparsely located. Multi-terminal HVDC (MTDC) provides …

A Quantitative Measure Of Mono-Componentness For Time-Frequency Analysis, Austin P. Albright

Doctoral Dissertations

Joint time-frequency (TF) analysis is an ideal method for analyzing non-stationary signals, but is challenging to use leading to it often being neglected. The exceptions being the short-time Fourier transform (STFT) and spectrogram. Even then, the inability to have simultaneously high time and frequency resolution is a frustrating issue with the STFT and spectrogram. However, there is a family of joint TF analysis techniques that do have simultaneously high time and frequency resolution – the quadratic TF distribution (QTFD) family. Unfortunately, QTFDs are often more troublesome than beneficial. The issue is interference/cross-terms that causes these methods to become so difficult …

A Study On Wide-Area Measurement-Based Approaches For Power System Voltage Stability, Haoyu Yuan

Doctoral Dissertations

With the development of wide-area monitoring system (WAMS) enabled by the synchrophasor technology, measurement-based approaches for power system voltage stability and control have been widely discussed in recent years. Based on high-frequency synchronized measurement signals collected from phasor measurement units (PMUs), these approaches have great potentials to significantly improve the situational awareness and to effectively guide the controls of interconnected modern power systems.

If compared with conventional model-based voltage stability assessment (VSA) and control methods, the measurement-based methods are relatively new. Although their simplicity and independence of system models make them suitable for online deployment, the applications of these measurement-based …

Design And Analysis Of A Fully-Integrated Resonant Gate Driver, Yu Long

Doctoral Dissertations

Several decades ago the resonant gate driving technique was proposed. Given the recent rapid growth in GaN HEMT power device applications for high-frequency power applications, research has been conducted in the power electronics field using resonant gate driving for GaN power devices. Previous research for resonant gate drivers for GaN HEMT devices mostly focused on implementing the gate driving function itself, and mostly for normally-on HEMT devices.

The normally-off (enhancement mode) GaN power device was introduced to the commercial market in 2009. A new resonate gate driver is proposed in this work to implement resonant gate driving for commercial high-speed …

Development Of Instrumentation And Control Systems For An Integral Large Scale Pressurized Water Reactor, Matthew Rowland Morrow Lish

Doctoral Dissertations

Small and large scale integral light water reactors are being developed to supply electrical power and to meet the needs of process heat, primarily for water desalination. This dissertation research focuses on the instrumentation and control of a large integral inherently safe light water reactor (designated as I²S-LWR) which is being designed as part of a grant by the U.S. Department of Energy Integrated Research Project (IRP). This 969 MWe integral pressurized water reactor (PWR) incorporates as many passive safety features as possible while maintaining competitive costs with current light water reactors. In support of this work, the …

Design And Control Of Close Proximity Indirect Exposure For Nonthermal Atmospheric Pressure Plasma-Based Oxidation Of Carbon Fiber Precursor, Truman Andrew Bonds

Doctoral Dissertations

A new plasma-based method for the stabilization of polyacrylonitrile carbon fiber precursor utilizing reactive chemical species derived from a custom atmospheric pressure plasma generation system was developed and demonstrated. As opposed to the conventional stabilization method of convective heating in air, plasma-based stabilization efficiently introduces oxidative reactive species that both diffuse through and react faster with the precursor filaments, resulting in a faster and more efficient process. This method was successfully demonstrated with a variety of precursor chemistries, grades and sizes. The development effort was entirely experimental, with successive processing devices designed and constructed to examine various aspects of the …

Cmos Based Impedance Sensing, Jinlong Gu

Masters Theses

This thesis focuses on a compact, low power circuit design for biological cell impedance sensing. Cell impedance sensing provides a new way to diagnose the cancers. Experiments done previously have shown that cancer cells have lower impedance than the normal cells, due to the thinner membrane of cancer cells. Traditional methods of cancer diagnosis require special chemicals, skilled personnel, and take long time to obtain the results. Two circuit structures are proposed in this work. One is a silicon cochlea based architecture. The other one is a current mode lock-in amplifier. Both of these two structures are able to measure …

Stochastic And Optimal Distributed Control For Energy Optimization And Spatially Invariant Systems, Jin Dong

Doctoral Dissertations

Improving energy efficiency and grid responsiveness of buildings requires sensing, computing and communication to enable stochastic decision-making and distributed operations. Optimal control synthesis plays a significant role in dealing with the complexity and uncertainty associated with the energy systems.

The dissertation studies general area of complex networked systems that consist of interconnected components and usually operate in uncertain environments. Specifically, the contents of this dissertation include tools using stochastic and optimal distributed control to overcome these challenges and improve the sustainability of electric energy systems.

The first tool is developed as a unifying stochastic control approach for improving energy efficiency …

Low-Noise Micro-Power Amplifiers For Biosignal Acquisition, Tan Yang

Doctoral Dissertations

There are many different types of biopotential signals, such as action potentials (APs), local field potentials (LFPs), electromyography (EMG), electrocardiogram (ECG), electroencephalogram (EEG), etc. Nerve action potentials play an important role for the analysis of human cognition, such as perception, memory, language, emotions, and motor control. EMGs provide vital information about the patients which allow clinicians to diagnose and treat many neuromuscular diseases, which could result in muscle paralysis, motor problems, etc. EEGs is critical in diagnosing epilepsy, sleep disorders, as well as brain tumors.

Biopotential signals are very weak, which requires the biopotential amplifier to exhibit low input-referred noise. …

An Innovative Approach To Johnson Noise Thermometry By Means Of Spectral Estimation, Nora Dianne Bull

Doctoral Dissertations

Instrumentation in a nuclear power plant is critical in monitoring the stability and safety levels of a reactor. Temperature is a key measurement performed on the core of a reactor to control the power output and sustain a safe thermal margin. If there is a dramatic change in temperature, failure is likely to follow if action is not taken to cool the system. Traditionally, to measure the temperature of a reactor, several resistance temperature detectors are placed in predefined locations on the system. Resistance temperature detectors (RTD) are typically platinum coiled wire wrapped around a ceramic cylinder and encased in …

Wide-Area Measurement-Based Applications For Power System Monitoring And Dynamic Modeling, Jidong Chai

Doctoral Dissertations

Due to the increasingly complex behavior exhibited by large-scale power systems with more uncertain renewables introduced to the grid, wide-area measurement system (WAMS) has been utilized to complement the traditional supervisory control and data acquisition (SCADA) system to improve operators’ situational awareness. By providing wide-area GPS-time-synchronized measurements of grid status at high time-resolution, it is able to reveal power system dynamics which cannot be captured before and has become an essential tool to deal with current and future power grid challenges. According to the time requirements of different power system applications, the applications can be roughly divided into online applications …

Dynamic Modeling And Renewable Integration Studies On The U.S. Power Grids, Gefei Kou

Doctoral Dissertations

Wind and solar generation have gained a significant momentum in the last five years in the United States. According to the American Wind Energy Association, the installed wind power capacity has tripled from 25,410 MW in early 2009 to 74,472 MW as of the end of 2015. Meanwhile, solar photovoltaic (PV) is reported that its capacity has skyrocketed from 298 MW in 2009 to 7,260 MW in 2015 by the Solar Energy Industries Association. Despite the fact that wind and solar only make up 4.4% and 0.4% , respectively, of total electricity generation in 2014, the nation is right on …

Data Analytics And Application Developments Based On Synchrophasor Measurements, Jiahui Guo

Doctoral Dissertations

Frequency Monitoring Network (FNET) is an Internet‐based, wide‐area phasor measurement system that collects power system data using Frequency Disturbance Recorders (FDRs) that are installed at the distribution level. These synchrophasor measurements enable the monitoring of bulk power systems, and provides wide‐area situational awareness and disturbance analysis for understanding power system disturbances and system operations. Various data analytics and applications are built based on these valuable measurements.

Real-time situational awareness tools are of critical importance to power system operators. Knowledge of the scope and extent of facilities impacted, as well as the duration of their dependence on backup power, enables emergency …

Multi-Physics Modeling, Ahmadreza Ghahremani

Doctoral Dissertations

Having access to powerful processors allows scientists to carry out aggressive numerical computations to bridge the gaps which already exist among different fields of physics by exploring new multi-physics models to approach real life models of various phenomena happening around us in real life and accounting of the various coupling and dependence between the various physical parameters and material parameters.

Scientists greatly appreciate multi-physics modeling as they recognize:

1- Prototyping is expensive

2- Most of available CAD tools are not addressing the real model or accounting between the different physical parameters

3- Some difficulties to optimize the real model without …

Real-Time Voltage Stability Monitoring And Control For Load Areas: A Hybrid Approach, Fengkai Hu

Doctoral Dissertations

This dissertation proposes a hybrid approach for real-time monitoring and controlling voltage stability of a load area fed by N tie lines. This hybrid approach integrates both simulation-based and measurement-based approaches for voltage stability assessment (VSA).

First, for measurement-based VSA (MBVSA), a new method is proposed for monitoring and control of load areas, which adopts an N+1 buses equivalent system so as to model and monitor individual tie lines of a load area compared to a traditional MBVSA method adopting a Thevenin equivalent. For each tie line, the new method solves the power transfer limit against voltage instability analytically …

Face Centered Image Analysis Using Saliency And Deep Learning Based Techniques, Rui Guo

Doctoral Dissertations

Image analysis starts with the purpose of configuring vision machines that can perceive like human to intelligently infer general principles and sense the surrounding situations from imagery. This dissertation studies the face centered image analysis as the core problem in high level computer vision research and addresses the problem by tackling three challenging subjects: Are there anything interesting in the image? If there is, what is/are that/they? If there is a person presenting, who is he/she? What kind of expression he/she is performing? Can we know his/her age? Answering these problems results in the saliency-based object detection, deep learning structured …

Bi-Level Optimization Considering Uncertainties Of Wind Power And Demand Response, Xin Fang

Doctoral Dissertations

Recently, world-wide power systems have been undergone a paradigm change with increasing penetration of renewable energy. The renewable energy is clean with low operation cost while subject to significant variability and uncertainty. Therefore, integration of renewables presents various challenges in power systems. Meanwhile, to offset the uncertainty from renewables, demand response (DR) has gained considerable research interests because of DR’s flexibility to mitigate the uncertainty from renewables. In this dissertation, various power system problems using bi-level optimization are investigated considering the uncertainties from wind power and demand response.

In power system planning, reactive power planning (RPP) under high-penetration wind power …

The Design And Validation Of A Wireless Bat-Mounted Sonar Recording System, Jeremy Joseph Langford

Masters Theses

Scientists studying the behavior of bats monitor their echolocation calls, as their calls are important for navigation and feeding, but scientist are typically restricted to ground-based recording. Recording bat calls used for echolocation from the back of the bat as opposed to the ground offers the opportunity to study bat echolocation from a vantage otherwise only offered to the bats themselves. However, designing a bat mounted in-flight audio recording system, (bat-tag), capable of recording the ultra-sound used in bat echolocation presents a unique set of challenges. Chiefly, the bat-tag must be sufficiently light weight as to not overburden the bat, …

Review And Characterization Of Gallium Nitride Power Devices, Edward Andrew Jones

Masters Theses

Gallium Nitride (GaN) power devices are an emerging technology that have only recently become available commercially. This new technology enables the design of converters at higher frequencies and efficiencies than those achievable with conventional Si devices. This thesis reviews the characteristics and commercial status of both vertical and lateral GaN power devices from the user perspective, providing the background necessary to understand the significance of these recent developments. Additionally, the challenges encountered in GaN-based converter design are considered, such as the consequences of faster switching on gate driver design and board layout. Other issues include the unique reverse conduction behavior, …

Adaptive Kernel Estimation For Enhanced Filtering And Pattern Classification Of Magnetic Resonance Imaging: Novel Techniques For Evaluating The Biomechanics And Pathologic Conditions Of The Lumbar Spine, Nicholas Vincent Battaglia

Doctoral Dissertations

This dissertation investigates the contribution the lumbar spine musculature has on etiological and pathogenic characteristics of low back pain and lumbar spondylosis. This endeavor necessarily required a two-step process: 1) design of an accurate post-processing method for extracting relevant information via magnetic resonance images and 2) determine pathological trends by elucidating high-dimensional datasets through multivariate pattern classification. The lumbar musculature was initially evaluated by post-processing and segmentation of magnetic resonance (MR) images of the lumbar spine, which characteristically suffer from nonlinear corruption of the signal intensity. This so called intensity inhomogeneity degrades the efficacy of traditional intensity-based segmentation algorithms. Proposed …

High Voltage Point Of Load Converter For Data Center Power Supplies, Yutian Cui

Doctoral Dissertations

With the increased cloud computing and digital information storage, the energy requirement of data centers where a large number of computer systems are housed keeps increasing. However, most of the data centers today are operated inefficiently, both economically and environmentally. Efforts including improving power delivery architecture, power conversion efficiency and thermal management have been made to increase the power delivery efficiency from grid to point of load.

In this dissertation, a new power delivery architecture, high voltage point of load (HV POL) architecture, has been proposed in order to improve power conversion and distribution efficiency for data center power supplies. …

Adopting 3d Time-Of-Flight Sensing Technology For Design Information Verification In International Safeguards, Matthew Stephen Duchene

Doctoral Dissertations

International safeguards inspectors periodically perform examinations at sensitive nuclear facilities to verify that the facilities’ designs, layouts, and functions are identical to information declared to the International Atomic Energy Agency (IAEA). Such design information verification (DIV) relies on tools and techniques—such as 3D laser range-finding (3DLR) with light detection and ranging (LIDAR) instruments—that are resource intensive. This research explores 3D Time-of-Flight (TOF) sensors as a possible alternative technology to LIDAR systems for performing spatial change-detection to enhance the DIV process.

This research uses the Microsoft Kinect Version 2 (Kinect v2) camera system, one of several commercial depth-sensing instruments that is …

Magnetic Local Positioning System With Supplemental Magnetometer-Accelerometer Data Fusion, Benjamin Scott Prothro

Doctoral Dissertations

Geo-location and tracking technology, once confined to the industrial and military sectors, have been widely proliferated to the consumer world since early in the twenty-first century. The commoditization of Global Positioning System (GPS) and inertial measurement integrated circuits has made this possible, with devices small enough to fit in a cellular phone. However, GPS technology is not without its drawbacks: Its power use is high, and it can fail in smaller, obstructed spaces. Magnetic positioning, which exploits the magnetic field coupling between a set of transmitter beacon coils and a set of receiver coils, is an often overlooked, complementary technology …

Motion-Activated Infrared Security System, Christopher H. Skelton, Daniel Graves, Kenton Culbertson, Joseph B. Burke, Edward Hockaday

Chancellor’s Honors Program Projects

No abstract provided.

Sic Band Gap Voltage Reference For Space Applications, Charles Kenneth Roberts

Masters Theses

Electronics for space applications can experience wide temperature swings depending on orientation towards stars and duty cycle of propulsion systems. Energy on satellites primarily comes from radiological thermal generators and / or solar panels. This requires space electronic applications to be energy efficient and have high temperature tolerance. As a result, space electronic systems use high efficiency SMPS [switching mode power supplies].

Currently, there exists SiC [silicon carbide] based electronics that is state of the art for high temperature applications. Commercial manufacturers at this time produce SiC Power MOSFETs [Metal Oxide Semiconductor Field Effect Transistors], which are the switching element …

Dynamic Extruder Control For Polymer Printing In Big Area Additive Manufacturing, Alex Christopher Roschli

Masters Theses

Big Area Additive Manufacturing (BAAM) is 3D Printing on a large scale and can be used to create structures on the scale of cars and houses. Scaling up 3D printing to BAAM size meant fundamentally altering the traditional fused deposition modeling process by switching from a filament to a pellet material feed. This meant switching from a stepper motor extruder to a servo driven screw extruder. While increasing the throughput of the system, this new extruder increases the overall complexity. Effective control of the system is paramount to the success of BAAM enabling it to effectively scale in speed in …

Design And Implementation Of An Integrated Biosensor Platform For Lab-On-A-Chip Diabetic Care Systems, Khandaker Abdullah Al Mamun

Doctoral Dissertations

Recent advances in semiconductor processing and microfabrication techniques allow the implementation of complex microstructures in a single platform or lab on chip. These devices require fewer samples, allow lightweight implementation, and offer high sensitivities. However, the use of these microstructures place stringent performance constraints on sensor readout architecture. In glucose sensing for diabetic patients, portable handheld devices are common, and have demonstrated significant performance improvement over the last decade. Fluctuations in glucose levels with patient physiological conditions are highly unpredictable and glucose monitors often require complex control algorithms along with dynamic physiological data. Recent research has focused on long term …

Second Creek Monitoring, Haley Whitaker, Aaron Young, Ryan Wagner, Saajid Haque, Benjamin Parrott, Richard Fagan

Chancellor’s Honors Program Projects

No abstract provided.

Energy Demand Management, Doug W. Bouler Iii, Alex Wortham, Asanga Bandara, Alex Chaloux

Chancellor’s Honors Program Projects

No abstract provided.