Engineering Commons^™

Electromagnetic Penetration Of Structures Considering High-Altitude Electromagnetic Pulse, David P. Mignardot

Masters Theses

The electric power system is undergoing transformation in the 21^st century. Generation is becoming more distributed, more electronic equipment is utilized for operation and control, and load demand is increasing with society’s electrification. As this transformation occurs, both new and old threats to the system’s resilience are of concern. Of the old threats, and a critical component when studying resilience, is high-altitude electromagnetic pulse (HEMP). In this thesis, weaponized electromagnetic pulse and its interaction with the power system is revisited with an emphasis on structure shielding effectiveness against both radiated and conducted energy. Computational electromagnetic plane wave simulations are …

Electric Vehicle Aggregation Considering Fast-Charging For Power System Applications, Trey I. Mingee

Masters Theses

The electric grid has become one of the most important pieces of technology for modern society, providing power to homes and businesses at all hours of the day. Future increases of worldwide electricity demand along with growing threats of contingency scenarios such as cyberattacks cause great concerns regarding the reliability of the grid. Further, the gradual shift from fossil fuels to renewable energy sources creates a significant need for grid support services to aid in its operation. Electric vehicles will become more prevalent in coming decades; these modules present unique loads to the system that are prime candidates for use …

Application Of Load Shifting For Commercial Hvac-R Systems Via Static And Dynamic Event Automated Demand Response, Justin Anthony Martinez

Masters Theses

Life in the modern era is inextricably tied to energy and the unending, ever-growing need for more. The technologies that drive society, in fields such as communication, infrastructure, and heavy industry, are dependent on that electrical energy being reliable and readily available. This places an extreme importance on the power generation sector as a function of meeting the demand required for stability. However, as seen with increased climate volatility due to misused or otherwise mismanaged resources in the heavy industry, and the uncertain and variable renewable energy generation; there must also be ecological as well as economic consideration when discussing …

Load Modeling And Evaluation Of Leds For Hardware Test Bed Application, Jillian M. Ruff

Masters Theses

The lighting industry was revolutionized with the emergence of LED lighting. Over the last 15 years, LED lighting device sales and utilization have grown immensely. The growth and popularity of LEDs is due to improved operation of the device when compared to previous lighting technologies. Efficient performance of the device is critical due to the growth of global energy consumption.

As nonrenewable generation fuel is finite, utilities have begun the transition to renewable energy generation. Generation and distribution systems become inherently complex to comprehend and maintain with incorporation of emerging supply and load technologies. With the unprecedented growth of LED …

State Level Trends In Renewable Energy Procurement Via Solar Installation Versus Green Electricity, Eric Michael Hanson

Masters Theses

“In the past 5 years, consumer options for procuring renewable energy have increased, ranging from rooftop solar installation to utility green pricing to Community Choice Aggregation. These options vary in terms of costs and benefits to the consumer as well as grid integration implications. However, little is known regarding how the presence of a wide range of options for utility-scale renewable procurement affects demand for distributed residential solar installations. In theory, there are three possible relationships, (1) positive correlation, where utility-scale and distributed resources complement each other to increase overall production, (2) negative correlation, where utility-scale and distributed resources are …

Partial Discharge Testing And Detection Under Pwm Voltage, John Meadors

Masters Theses

Partial Discharge detection and measurement is an important part of electric insulation design. However, in PWM (pulse width modulation) voltage source converter environments, the noise resulting from switching voltage (rise and fall times of tens of nanoseconds) makes detection and extraction of partial discharge difficult. Unique methods of partial discharge detection are needed to address and decouple the noise from partial discharge measurements. PWM voltage can feature high switching speeds and high dv/dt during voltage switching. These PWM voltage behaviors are not found in traditional utility high voltage applications, and the effects that this type of voltage has on insulation …

High Frequency Injection Sensorless Control For A Permanent Magnet Synchronous Machine Driven By An Fpga Controlled Sic Inverter, Jared Walden

Masters Theses

As motor drive inverters continue to employ Silicon Carbide (SiC) and Gallium Nitride (GaN) devices for power density improvements, sensorless motor control strategies can be developed with field-programmable gate arrays (FPGA) to take advantage of high inverter switching frequencies. Through the FPGA’s parallel processing capabilities, a high control bandwidth sensorless control algorithm can be employed. Sensorless motor control offers cost reductions through the elimination of mechanical position sensors or more reliable electric drive systems by providing additional position and speed information of the electric motor. Back electromotive force (EMF) estimation or model-based methods used for motor control provide precise sensorless …

Power System Stability Assessment With Supervised Machine Learning, Mirka Mandich

Masters Theses

Power system stability assessment has become an important area of research due to the increased penetration of photovoltaics (PV) in modern power systems. This work explores how supervised machine learning can be used to assess power system stability for the Western Electricity Coordinating Council (WECC) service region as part of the Data-driven Security Assessment for the Multi-Timescale Integrated Dynamics and Scheduling for Solar (MIDAS) project. Data-driven methods offer to improve power flow scheduling through machine learning prediction, enabling better energy resource management and reducing demand on real-time time-domain simulations. Frequency, transient, and small signal stability datasets were created using the …

Modeling And Evaluation Of Utility-Scale Microgrid Investment For Distribution System Planning, Ian Schomer

Masters Theses

The electrical distribution network faces two great challenges for the immediate future. First, increased affordability of distributed energy resources (DERs)—and advancing control technologies of inverters that interface them to the grid—have driven a shift from a passive to an active distribution network (ADN), which heightens the complexity of system management. Second, the increased frequency of severe weather events and increased potential for a cybersecurity attack necessitate the need for a resilient infrastructure that can respond adaptively to shutdowns within the system. Microgrids (MGs) present a promising framework both to provide hierarchal control of DERs and to increase resiliency with grid-forming …

Development Of A Converter-Based Testing Platform And Battery Energy Storage System (Bess) Emulator For Microgrid Controller Function Evaluation, Dingrui Li

Masters Theses

The microgrid has attracted increasing research attention in the last two decades. Due to the development of renewable energy resources and power electronics technologies, the future microgrid will trend to be smarter and more complicated. The microgrid controller performs a critical role in the microgrid operation, which will also become more and more sophisticated to support the future microgrid. Before final field deployment and test, the evaluation and testing of the controller is an indispensable step in the controller development, which requires a proper testing platform.

However, existing simulation-based platforms have issues with potential numerical oscillation and may require huge …

A Communications Testbed For Testing Power Electronic Agent Systems, Benjamin R. Dean

Masters Theses

As power electronic system (PES) continue to incorporate complex intra-system communication, understanding and characterizing this communication has become a complex task. Knowing how a system’s communication will behave is vital to ensuring proper operation of these systems. This thesis proposes and outlines a communication testbed that streamlines the development and testing of the communications between the components of PES, and further presents the characterization of communication protocol utilized in these multi-agent PESs. These communication protocols include MQTT, Modbus, or User Datagram Protocol (UDP). Understanding the different behavior of these protocols presents is paramount for the design of PESs.

Bond Graph Modeling Of Critical Infrastructures For Cyber-Physical Security Implementation, Michele Jane White

Masters Theses

“In developed societies, there exists infrastructure vital to everyday life. This includes water and power systems. Technology is quickly evolving and being implemented on these utilities. This technology can range from smart metering in neighborhoods to volume sensors in local waste water treatment facilities. When networking, sensing, monitoring, or control devices are integrated with infrastructure it is considered a cyber physical system, or CPS. When information about an important physical system is connected to the virtual world, it is opened up to security risks. Cyber security can be provided to the CPS by monitoring the physical state of the system …

Physics-Based Modeling Of Lithium-Ion Batteries For Control And Estimation Applications, Brody J. C. Riemann

Masters Theses

“Lithium-ion batteries are extensively used in many application areas like consumer electronics, electric vehicles, and microgrids. As the world moves towards further electrification of vehicles and more widespread use of renewable energy sources, the need for large-scale battery storage systems will grow. To effectively replace conventional methods, batteries will need to be charged quickly while accounting for degradation to maximize lifetime. Further, larger batteries require more detailed safety monitoring, which is implemented using a battery management system (BMS). A BMS is responsible for state of charge (SOC) estimation, state of health (SOH) estimation, cell balancing, regulating voltage and current according …

Design Of Power Receiving Units For 6.78mhz Wireless Power Transfer Systems, Hoang Phuc Tran Pham

Masters Theses

In the last decade, the wireless power transfer (WPT) technology has been a popular topic in power electronics research and increasingly adopted by consumers. The AirFuel WPT standard utilizes resonant coils to transfer energy at 6.78 MHz, introducing many benefits such as longer charging distance, multi-device charging, and high tolerance of the coil misalignment. However, variations in coil coupling due to the change in receiving coil positions alter the equivalent load reactance, degrading efficiency.

In recent studies, active full-bridge rectifiers are employed on WPT receivers because of their superior efficiency, controllability, and ability to compensate for detuned WPT networks. In …

Passive And Active Battery Balancing Methods Implemented On Second Use Lithium-Ion Batteries, Walter Bartek

Masters Theses

As the number of electric vehicles (EVs) increases, the number of used battery packs that require disposal increases; however, many of these packs still have useful capacity and can be repurposed. When using repurposed large lithium-ion battery packs, deviations between cells within a pack become problematic. These deviations result in a pack that is unbalanced, affecting performance and proving potentially hazardous when charging. Consequently, a battery management system (BMS) is needed. To provide safety, the BMS in this paper monitors and controls the operation of the battery pack. In addition, it controls the redistribution of charge between the cells within …

Power Optimization Of Solar Powered Standalone Wireless Sensor System, Rajan Amatya

Masters Theses

Wireless sensor systems are common in applications where harsh environmental conditions or remote locations make it difficult to run wires. Having these sensor systems self-powered is essential as it is difficult for battery replacement. Using solar as an alternative source of energy can be a medium to charge the battery in such scenarios. With an increasing number of portable devices powered by battery; more and more research is focused on low-power design technique. For this thesis, a microcontroller (Texas Instruments MSP432) was used along with a digital sensor (Bosch BME280) to provide temperature, pressure and humidity information, and Wi-Fi module …

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 …

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 …

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 …

Z Deviation Based Demand Side Control To Reduce Fidvr, Derek Brittian Lusby

Masters Theses

Accurate load modeling is key to depicting realistic system behavior in power system simulations. In the past, the use of static load models resulted in overly optimistic results, which led to unforeseen outages and issues following faults. One common cause of these types of unforeseen issues is Fault Induced Delayed Voltage Recovery (FIDVR). FIDVR occurs due to the stalling of single-phase residential air conditioners (A/C), and causes the voltage recovery after a fault to be slow. Improvements in load models over time have resulted in the capability of modeling load dynamics, and therefore better FIDVR.

A composite load model based …

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, …

Hybrid Fuzzy-Pid Controller For Buck-Boost Converter In Solar Energy-Battery Systems, Karime Farhood Hussein

Masters Theses

In the present work, we propose a hybrid fuzzy PID control system to prevent overshoot and oscillations in DC-DC buck-boost converter for solar-battery system. We design and simulate a PID, a Fuzzy logic controller, and hybrid fuzzy PID control system to stabilize the output voltage of the buck-boost converter. The performance results using dynamic response of all of these controllers in terms of rise time, overshoot, peak time, and voltage oscillation are presented. The simulation results support the validity and advantages of the hybrid method.

A New Approach To Optimization Of Dynamic Reactive Power Sources Addressing Fidvr Issues, Weihong Huang

Masters Theses

Dynamic reactive power (var) sources, e.g. SVCs and STATCOMs, can effectively mitigate fault-induced delayed voltage recovery (FIDVR) issues or even voltage collapse. However, their optimal allocation in a power grid is a complicated nonlinear optimization problem since the post-fault voltage trajectories have to be solved to check constraints on voltage responses. Thus, solvers of both nonlinear optimization and power system differential and algebraic equations (DAEs) are required.

Currently, most of existing methods merely achieve dynamic optimization locally with great dependence on the initial operation point. Also, complicated algorithm and time consuming are obstacles for the practical implementation.

This thesis proposes …

An Autonomous Online I-V Tracer For Pv Monitoring Applications, Cameron William Riley

Masters Theses

With the unprecedented growth of photovoltaic technologies and their implementation in recent times, more precise methods of determining modules health, degradation, and performance are needed. Current monitoring efforts are helpful in determining these attributes but do not provide all of the information necessary to truly understand the health properties of the PV module in question. The current-voltage curve, or I-V curve, provides a level of insight into a PV module’s health unparalleled by most monitoring efforts. However, the tools which measure the I-V curve exist in an undesirable form—PV must be disconnected from its load and connected to the tool …

Statistical Analysis Of Disturbances In Power Transmission Systems, Liu Liu

Masters Theses

Disturbance analysis is essential to the study of the power transmission systems. Traditionally, disturbances are described as megawatt (MW) events, but the access to data is inefficient due to the slow installation and authorization process of the monitoring device. In this paper, we propose a novel approach to disturbance analysis conducted at the distribution level by exploiting the frequency recordings from Frequency Disturbance Recorders (FDRs) of the Frequency Monitoring Network (FNET/GridEye), based on the relationship between frequency change and the power loss of disturbances - linearly associated by the Frequency Response. We first analyze the real disturbance records of North …

Development Of A Testing Platform For Secondary-Use Electric Vehicle Batteries As Community Energy Storage Systems, Thomas Benjamin Ollis

Masters Theses

Energy storage is quickly transforming from a commodity to a necessity for electric utilities. The peak demand on the electric grid continues to grow, requiring more sources of generation and upgrades to infrastructure. The variability of renewable generation sources, such as wind and solar, has created more uncertainty on the generation side of the electric grid. Energy storage represents one possible solution to mitigate the demand and uncertainty; however, energy storage systems have historically been too expensive to recoup their capital cost. More recently, research into electric vehicle batteries has brought their cost down and improved performance. As they continue …

Hardware-In-Loop Evaluation Of Microgrid Protection Schemes, Kevin Michael Dowling

Masters Theses

Distributed energy resources are becoming more common in distribution systems. Higher energy prices and increased interest in alternative energy sources are two of the driving forces behind this trend. Local utilities, however, anticipate very serious distribution system protection problems resulting from high penetration of these resources.

The microgrid concept has been proposed as a possible solution to integrating distributed energy resources without adversely impacting the distribution system. Protection schemes have been proposed to work within this microgrid structure, but very little testing with real hardware is available. Without a practical solution for microgrid protection, backed by extensive studies, microgrids are …

An Occupant-Based Dynamic Simulation Tool For Predicting Residential Power Demand And Quantifying The Impact Of Residential Demand Response, Brandon Jeffrey Johnson

Masters Theses

With their large impact on the power system and widespread distribution, residential loads provide vast resources that if utilized correctly have the potential to help reduce both electricity cost and demand throughout the day. Previous research in this area has been primarily focused on building more energy efficient homes and improving the efficiencies of appliances and lighting technologies. Far less attention has been given to the ability of residential loads to provide various demand response services. Residential loads with demand response capabilities have the potential to be very useful in both peak shifting and regulation applications, and could be utilized …

Arm Inductance And Sub-Module Capacitance Selection In Modular Multilevel Converter, Yalong Li

Masters Theses

Arm inductor and sub-module (SM) capacitor are two key components in the modular multilevel converter (MMC). Optimizing the selection of arm inductance and sub-module capacitance is thus critical for the converter design. This report aims at developing a selection principle for arm inductance and sub-module capacitance in MMC.

Arm inductors in MMC are used to limit the circulating current which flows within the converter. The switching frequency harmonic is found to be the dominant component in the circulating current when an active circulating current suppressing controller is implemented. The analytical relationship between the arm inductance and switching frequency circulating current …

Novel Applications For Phasor Measurement Units And Synchrophasor Data, Bradley Kerwin Greene

Masters Theses

The last decade has seen an intensified effort towards an improved, technologically advanced electric grid. This effort is largely in part to the need for cleaner and renewable sources of energy. Another motivator for this “smarter grid” is the need for a more reliable and efficiently operated of the wide scale electric infrastructure. The impact of these changes can expect to be seen at both the transmission and distribution level. At the transmission level phasor measurement units and synchrophasor data has emerged as one of the most enabling technologies for the smart grid movement. These devices measure and time synchronize, …