Engineering Commons^™

A Wide Area Hierarchical Voltage Control For Systems With High Wind Penetration And An Hvdc Overlay, Yidan Lu

Doctoral Dissertations

The modern power grid is undergoing a dramatic revolution. On the generation side, renewable resources are replacing fossil fuel in powering the system. On the transmission side, an AC-DC hybrid network has become increasingly popular to help reduce the transportation cost of electricity. Wind power, as one of the environmental friendly renewable resources, has taken a larger and larger share of the generation market. Due to the remote locations of wind plants, an HVDC overlay turns out to be attractive for transporting wind energy due to its superiority in long distance transmission of electricity.

While reducing environmental concern, the increasing …

Wide-Area Control Schemes To Improve Small Signal Stability In Power Systems, Meimanat Mahmoudi

Doctoral Dissertations

One of the main concerns for the secure and reliable operation of power systems is the small signal stability problem. In the complex and highly interconnected structure of future power systems, relying solely on operator responses and conventional controls cannot assure reliability. Therefore, there is a need for advanced Wide-Area Control Schemes (WACS) that can automatically respond to degradation of reliability in the system.

The main objective of this dissertation is to address two key challenges regarding the design and implementation of wide-area control schemes for damping inter-area oscillations. First is the high communication cost associated with optimal centralized control …

Analysis Of Nfirs Data For Sensitivity To Foreclosure And Other Select Features, Alexander Meadows Asbury

Masters Theses

Arson is a grave threat to life and property. In the United States, fire information is collected and disseminated through the National Fire Incident Reporting System (NFIRS). Fire records obtained from NFIRS contain a full range of available information. This information includes the initial incident details in addition to investigative information regarding the cause of ignition and factors contributing to ignition. Combating the arson problem is accomplished in large part by understanding the motives and opportunities of those who commit arson. A common motive for arson is financial gain through insurance fraud. By connecting NFIRS data with mortgage and foreclosure …

An Analog Cmos Particle Filter, Trevor Watson

Masters Theses

Particle filters are used in a variety of image processing and machine learning applications. Their main use in these applications is to gather information about a system of objects, by using partial or noisy observations collected from sensors. These observations are used to associate points of interest in the observations with objects and maintain this association through a series of observations.

In this paper I will investigate the performance of a particle filter implemented in 130nm analog CMOS hardware. The design goal of the particle filter is low-microwatt power consumption. Using analog hardware, rather than digital ASICs or CPUs I …

Design Considerations For Paralleling Multiple Chips In Sic Power Modules, Fei Yang

Masters Theses

With the benefits of fast switching speed, low on-resistance and high thermal conductivity, silicon carbide (SiC) devices are being implemented in converter designs with high efficiency and high power density. Consequently, SiC power modules are needed. However, some of the preestablished package designs for silicon based power modules are not suitable to manifest the advantages of SiC devices. Therefore, this thesis aims at optimizing the package design to utilize the fast switching capability of SiC devices.

First, the power loop parasitic inductance induced by the package can lead to large voltage spikes with the fast switching SiC device. It can …

Design And Evaluation Of A Sub-1-Volt Read Flash Memory In A Standard 130 Nanometer Cmos Process, David Andrew Basford

Masters Theses

Nonvolatile memory design is a discipline that employs digital and analog circuit design techniques and requires knowledge of semiconductor physics and quantum mechanics. Methods for programming and erasing memory are discussed here, and simulation models are provided for Impact Hot Electron Injection (IHEI), Fowler-Nordheim (FN) tunneling, and direct tunneling. Extensive testing of analog memory cells was used to derive a set of equations that describe the oating-gate characteristics. Measurements of charge retention also revealed several leakage mechanisms, and methods for mitigating leakage are presented.

Fabrication of ash memory in a standard CMOS process presents significant design challenges. The absence of …

Learning Multimodal Structures In Computer Vision, Ali Taalimi

Doctoral Dissertations

A phenomenon or event can be received from various kinds of detectors or under different conditions. Each such acquisition framework is a modality of the phenomenon. Due to the relation between the modalities of multimodal phenomena, a single modality cannot fully describe the event of interest. Since several modalities report on the same event introduces new challenges comparing to the case of exploiting each modality separately.

We are interested in designing new algorithmic tools to apply sensor fusion techniques in the particular signal representation of sparse coding which is a favorite methodology in signal processing, machine learning and statistics to …

Design And Implementation Of A Low‐Power Wireless Respiration Monitoring Sensor, Ifana Mahbub

Doctoral Dissertations

Wireless devices for monitoring of respiration activities can play a major role in advancing modern home-based health care applications. Existing methods for respiration monitoring require special algorithms and high precision filters to eliminate noise and other motion artifacts. These necessitate additional power consuming circuitry for further signal conditioning. This dissertation is particularly focused on a novel approach of respiration monitoring based on a PVDF-based pyroelectric transducer. Low-power, low-noise, and fully integrated charge amplifiers are designed to serve as the front-end amplifier of the sensor to efficiently convert the charge generated by the transducer into a proportional voltage signal. To transmit …

Computational Imaging Approach To Recovery Of Target Coordinates Using Orbital Sensor Data, Michael D. Vaughan

Doctoral Dissertations

This dissertation addresses the components necessary for simulation of an image-based recovery of the position of a target using orbital image sensors. Each component is considered in detail, focusing on the effect that design choices and system parameters have on the accuracy of the position estimate. Changes in sensor resolution, varying amounts of blur, differences in image noise level, selection of algorithms used for each component, and lag introduced by excessive processing time all contribute to the accuracy of the result regarding recovery of target coordinates using orbital sensor data.

Using physical targets and sensors in this scenario would be …

Wide-Area Measurement-Driven Approaches For Power System Modeling And Analytics, Hesen Liu

Doctoral Dissertations

This dissertation presents wide-area measurement-driven approaches for power system modeling and analytics. Accurate power system dynamic models are the very basis of power system analysis, control, and operation. Meanwhile, phasor measurement data provide first-hand knowledge of power system dynamic behaviors. The idea of building out innovative applications with synchrophasor data is promising.

Taking advantage of the real-time wide-area measurements, one of phasor measurements’ novel applications is to develop a synchrophasor-based auto-regressive with exogenous inputs (ARX) model that can be updated online to estimate or predict system dynamic responses.

Furthermore, since auto-regressive models are in a big family, the ARX model …

Modeling And Design Of A Low-Level Rf Control System For The Accumulator Ring At Spallation Neutron Source, Michael G. Trout

Masters Theses

Since its commissioning in 2006, Spallation Neutron Source (SNS) at Oak Ridge National Laboratory has greatly contributed to the field of neutron science, but some critical systems are reaching end-of-life. This obsolescence must be addressed for the accelerator to continue providing world-class research capabilities. One such system needing redesign is the low-level RF (LLRF) control system for the proton accumulator ring. While this system has performed acceptably for over a decade, it is sparsely documented and robust operational models are unavailable. To ensure the new design meets or exceeds current performance metrics, we analyzed the existing LLRF control system and …

High-Current Integrated Battery Chargers For Mobile Applications, Gabriel Alejo Gabian

Masters Theses

Battery charging circuits for mobile applications, such as smart phones and tablets, require both small area and low losses. In addition, to reduce the charging time, high current is needed through the converter. In this work, exploration of the Buck, the 3-Level Buck and the Hybrid Buck converter is performed over the input voltage, the total FET area and the load current. An analytical loss model for each topology is constructed and constrated by experimental results. In addition, packaging and bond wire impact on on-chip losses is analyzed by 3D modeling. Finally, a comparison between the topologies is presented determining …

Design Of An Integrated Silicon Carbide Nonlinear-Carrier Pwm Controller For Boost Converter Applications, Richard Kyle Harris

Masters Theses

Power electronics consisting of a switch mode power supply with feedback control have a great number of applications, including many that require extreme environment capability, such as the aerospace and automotive industries.

Silicon carbide (SiC) is a common material in which power devices are created for use in switch mode power supplies, such as boost converters, giving those power supplies extremely high temperature capabilities. To truly realize the temperature capabilities of SiC in power supplies, an integrated SiC converter has been designed that is also high-temperature capable.

Herein, the properties of SiC integrate circuit (IC) processes are discussed and nonlinear-carrier …

Battery Energy Storage Emulation For Power System Applications, Jessica Danielle Boles

Masters Theses

The concept of energy storage for power systems has received increasingly more attention in recent decades, and the growing penetration of renewable energy sources has only escalated demand for it. Energy storage systems are excellent for balancing generation and load, for suppressing power fluctuations, and for providing other ancillary services to the grid. The Hardware Testbed (HTB) is a novel converter-based grid emulator created for studying the needs associated with high renewable penetration, but the system currently lacks a battery storage emulator. Thus, this work documents the development of a battery energy storage system (BESS) emulator for the HTB.

The …

Loss Model For Gallium Nitride Dc-Dc Buck Converter, Rushi P. Patel

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

In recent years, more research has been done on Enhancement Mode Gallium Nitride (eGaN) converters, as the world is moving towards more power efficient converters. Power converters play a major role in efficiently controlling and converting electric energy used by machines, systems, and everyday products. The process to make converters more efficient was complicated and slow in the twentieth century. One of the important aspects in power electronics is to evaluate different losses and minimize losses to achieve high efficiency of the converter. With help of simulation tools such as MATLAB and LTspice, this process has become much faster and …

Control Oriented Nonlinear Model Reduction For Distributed Parameter Systems, Samir Sahyoun

Doctoral Dissertations

The development of model reduction techniques for physical systems modeled by partial differential equations (PDEs) has been a very active research area. Large number of states is needed to accurately capture the dynamics of such systems which makes them unsuitable for control design. The order of the system must be reduced prior to control design. In this dissertation, new methods that generalize the popular proper orthogonal decomposition (POD) to nonlinear PDEs are investigated. In particular, cluster based POD algorithms are developed and applied to the one and two dimensional Burgers equations that govern a nonlinear convective ow. Each cluster contains …

Electricity Market Designs For Demand Response From Residential Customers, Ailin Asadinejad

Doctoral Dissertations

The main purpose of this dissertation is to design an appropriate tariff program for residential customers that encourages customers to participate in the system while satisfying market operators and utilities goals. This research investigates three aspects critical for successful programs: tariff designs for DR, impact of renewable on such tariffs, and load elasticity estimates. First, both categories of DR are modeled based on the demand-price elasticity concept and used to design an optimum scheme for achieving the maximum benefit of DR. The objective is to not only reduce costs and improve reliability but also to increase customer acceptance of a …

Wide-Area Synchrophasor Data Server System And Data Analytics Platform, Dao Zhou

Doctoral Dissertations

As synchrophasor data start to play a significant role in power system operation and dynamic study, data processing and data analysis capability are critical to Wide-area measurement systems (WAMS). The Frequency Monitoring Network (FNET/GridEye) is a WAMS network that collects data from hundreds of Frequency Disturbance Recorders (FDRs) at the distribution level. The previous FNET/GridEye data center is limited by its data storage capability and computation power. Targeting scalability, extensibility, concurrency and robustness, a distributed data analytics platform is proposed to process large volume, high velocity dataset. A variety of real-time and non-real-time synchrophasor data analytics applications are hosted by …

Impedance-Based Stability Analysis And Controller Design Of Three-Phase Inverter-Based Ac Systems, Wenchao Cao

Doctoral Dissertations

Three-phase voltage-source power inverters are widely used for energy conversion in three-phase ac systems, such as renewable energy systems and microgrids. These three-phase inverter-based ac systems may suffer from small-signal instability issues due to the dynamic interactions among inverters and passive components in the systems. It is crucial for system integrators to analyze the system stability and design the inverter controller parameters during system planning and maintenance periods to guarantee stable system operation. The impedance-based approach can analyze the stability of source-load systems, by applying the Nyquist stability criterion or the generalized Nyquist stability criterion (GNC) to the impedance ratio …

Management Of Islanded Operation Of Microgirds, Md Riyasat Azim

Doctoral Dissertations

Distributed generations with continuously growing penetration levels offer potential solutions to energy security and reliability with minimum environmental impacts. Distributed Generations when connected to the area electric power systems provide numerous advantages. However, grid integration of distributed generations presents several technical challenges which has forced the systems planners and operators to account for the repercussions on the distribution feeders which are no longer passive in the presence of distributed generations.

Grid integration of distributed generations requires accurate and reliable islanding detection methodology for secure system operation. Two distributed generation islanding detection methodologies are proposed in this dissertation. First, a passive …

Electric Power System Operations With A Variable Series Reactor, Xiaohu Zhang

Doctoral Dissertations

Series FACTS devices, such as a Variable Series Reactor (VSR), have the ability to continuously regulate the transmission line reactance so as to control power ow. This research work evaluates the benefits brought by VSRs in different aspects of power system and develops efficient planning models and algorithms to provide optimal investment plan for the VSRs.

First, an optimization approach capable of finding both optimal locations and settings of VSRs under a specific operating condition is developed. The tool implements a full ac model as well as detailed models for different power system components.

Second, an optimization tool which can …

Development Of A Low Cost Biosensing Platform For Highly Sensitive And Specific On-Site Detection Of Pathogens And Infections, Cheng Cheng

Doctoral Dissertations

A highly sensitive, specific, real time, and field-deployable surveillance tool is critical to the control of pathogens and infections, as well as ecological impact of chemicals exposure. This work investigates the development of a low cost biosensing platform that can be used for viral disease diagnosis and chemical detection. The sensing mechanism is known as AC electrokinetics (ACEK) capacitive sensing. By applying an inhomogeneous AC electric field on sensor electrodes, positive dielectrophoresis is induced to accelerate the travel of analytes. The same applied AC signal also directly measures the capture of target by the probe on sensor surface. The realized …

Monolithic Perimeter Gated Single Photon Avalanche Diode Based Optical Detector In Standard Cmos, Md. Habib Ullah Habib

Doctoral Dissertations

Since the 1930's photomultiplier tubes (PMTs) have been used in single photon detection. Single photon avalanche diodes (SPADs) are p-n junctions operated in the Geiger mode. Unlike PMTs, CMOS based SPADs are smaller in size, insensitive to magnetic fields, less expensive, less temperature dependent, and have lower bias voltages. Using appropriate readout circuitry, they measure properties of single photons, such as energy, arrival time, and spatial path making them excellent candidates for single photon detection. CMOS SPADs suffer from premature breakdown due to the non-uniform distribution of the electric field. This prevents full volumetric breakdown of the device and reduces …

Target Detection With Neural Network Hardware, Hollis Bui, Garrett Massman, Nikolas Spangler, Jalen Tarvin, Luke Bechtel, Kevin Dunn, Shawn Bradford

Chancellor’s Honors Program Projects

No abstract provided.

Design And Implementation Of Power Electronics For An Electric Bicycle, Kyle Jackson Goodrick, Jared Baxter, Jacob Dyer

Chancellor’s Honors Program Projects

No abstract provided.

The Development Of A Partial Flow Sensor For Tiles, Richard Mcever

Chancellor’s Honors Program Projects

No abstract provided.

A Wide-Area Analysis Of Shifts In Electric Power System Generation Profiles And High-Impact Event Scenarios, Micah Joel Till

Doctoral Dissertations

Often cited as the largest machine in the world, the electric power grid is a complex system, integral to modern life. Continuous technology advancements over the past hundred years have delivered improvements to both the system itself, e.g., wide-area management systems (WAMS), as well as modeling capabilities in order to better understand how that system functions. Phenomena that could once be simulated only in small, localized settings can now be studied from a wide-area perspective.

Chapter 1 briefly introduces the three major U.S. electric interconnections along with wide-area power system analysis tools and the benchmarked models used in this work. …

Co-Optimization Of Gas-Electricity Integrated Energy Systems Under Uncertainties, Linquan Bai

Doctoral Dissertations

In the United States, natural gas-fired generators have gained increasing popularity in recent years due to low fuel cost and emission, as well as the needed large gas reserves. Consequently, it is worthwhile to consider the high interdependency between the gas and electricity networks. In this dissertation, several co-optimization models for the optimal operation and planning of gas-electricity integrated energy systems (IES) are proposed and investigated considering uncertainties from wind power and load demands.

For the coordinated operation of gas-electricity IES: 1) an interval optimization based coordinated operating strategy for the gas-electricity IES is proposed to improve the overall system …

Effects Of Distance, Antenna, And Channel On An Ultra Wide Band Location System, And Quantifying Them To Increase Accuracy, Nicholas Alexander Cavopol

Masters Theses

Localization has been evolving rapidly over the last 20 years, especially in the wireless world. From the advent of GPS, as well as the personal smart phone, localization has become accessible to most of the developed world. From the ability to find ones’ smartphone using a computer, to being able to locate ones’ keys using radio frequencies, there are many ways that localization has entered our lives in the last few years, however most of these either do not have high accuracy, or are only accurate in an outside environment. For indoor tracking, new technologies have been developed to help …

A Practical Realization Of A Return Map Immune Lorenz Based Chaotic Stream Cipher In Circuitry, Daniel Robert Brown

Masters Theses

Some chaotic systems are advantageously capable of self-synchronizing with a like system through a single shared state. Using a plain text binary message, a single system parameter can be modulated to mask this message and transmit it securely through the single shared state. The most simple implementations of this encryption technique are, however, vulnerable to the return map attack. Using a time-scaling factor to further obfuscate the modulation process, a return map attack immunity is gained. We report on the progress towards a realization of this process in real-time analog circuitry using off-the-shelf components.