Power and Energy Commons^™

Design And Optimization Of A High Power Density Silicon Carbide Traction Inverter, Tyler Adamson

Graduate Theses and Dissertations

This project was initiated with the goal of demonstrating a 3-phase silicon carbide based 150-kW 25 kW/L DC-AC power conversion unit capable of operation with coolant temperatures up to 90°C. The project goals were met and exceeded by first analyzing the established inverter topologies to find which one would yield the highest power density while still meeting electrical performance needs in the 150-kW range. Following topology selection, the smallest silicon carbide power module that met the electrical requirements of the system was found through experimental testing and simulation. After a power module selection was finalized, a DC link capacitor bank …

Fractional Order State Feedback Control For Improved Lateral Stability Of Semi-Autonomous Commercial Heavy Vehicles, Rasheed Mazen Abdulkader

Graduate Theses and Dissertations

With the growing development of autonomous and semi-autonomous large commercial heavy vehicles, the lateral stability control of articulated vehicles have caught the attention of researchers recently. Active vehicle front steering (AFS) can enhance the handling performance and stability of articulated vehicles for an emergency highway maneuver scenario. However, with large vehicles such tractor-trailers, the system becomes more complex to control and there is an increased occurrence of instabilities. This research investigates a new control scheme based on fractional calculus as a technique that ensures lateral stability of articulated large heavy vehicles during evasive highway maneuvering scenarios. The control method is …

Adaptive Boundary Control Using The Natural Switching Surfaces For Flyback Converters, Luciano Andres Garcia Rodriguez

Graduate Theses and Dissertations

The derivation and implementation of the natural switching surfaces (NSS) considering certain parametric uncertainties for a flyback converter operating in the boundary conduction mode (BCM) is the main focus of this paper. The NSS with nominal parameters presents many benefits for the control of nonlinear systems; for example, fast transient response under load-changing conditions. However, the performance worsens considerably when the converter actual parameters are different from the ones used in the design process. Therefore, a novel control strategy for NSS considering the effects of parameter uncertainties is proposed. This control law can estimate and adapt the control trajectories in …

Evaluation And Analysis Of Null Convention Logic Circuits, John Davis Brady

Graduate Theses and Dissertations

Integrated circuit (IC) designers face many challenges in utilizing state-of-the-art technology nodes, such as the increased effects of process variation on timing analysis and heterogeneous multi-die architectures that span across multiple technologies while simultaneously increasing performance and decreasing power consumption. These challenges provide opportunity for utilization of asynchronous design paradigms due to their inherent flexibility and robustness.

While NULL Convention Logic (NCL) has been implemented in a variety of applications, current literature does not fully encompass the intricacies of NCL power performance across a variety of applications, technology nodes, circuit scale, and voltage scaling, thereby preventing further adoption and utilization …

Backstepping Control And Transformation Of Multi-Input Multi-Output Affine Nonlinear Systems Into A Strict Feedback Form, Khalid Salim D. Alharbi

Graduate Theses and Dissertations

This dissertation presents an improved method for controlling multi-input multi-output affine nonlinear systems. A method based on Lie derivatives of the system's outputs is proposed to transform the system into an equivalent strict feedback form. This enables using backstepping control approaches based on Lyapunov stability and integrator backstepping theory to be applied. The geometrical coordinate transformation of multi-input multi-output affine nonlinear systems into strict feedback form has not been detailed in previous publications. In this research, a new approach is presented that extends the transformation process of single-input single-output nonlinear. A general algorithm of the transformation process is formulated. The …

Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, Rafael Franceschi

Graduate Theses and Dissertations

This thesis presents and evaluates a solution for unbalanced current loading in three-phase distribution systems. The proposed solution uses the flying capacitor multilevel converter as its main topology for an application known as Unbalanced Current Static Compensator. The fundamental theory, controller design and prototype construction will be presented along with the experimental results. The Unbalanced Current Static Compensator main objective is the balancing of the up-stream currents from the installation point to eliminate the negative- and zero-sequence currents originated by unbalanced single-phase loads.

Three separate single-phase flying capacitor converters are controlled independently using a d-q rotating reference frame algorithm to …

H2 Control For Improved Stability Of Multi-Area Electric Power System With High Levels Of Inverter-Based Generation, Muthanna Abdulkareem Al-Sarray

Graduate Theses and Dissertations

Increased generation capacity from non-dispatchable energy resources such as wind and solar has created challenges to ensuring the reliable delivery of electric power. This research develops a systematic three-step method of assessing the reliability of electric power systems under a variety of different possible fault conditions to ensure that overall system stability is preserved in a manner the meets regulatory requirements. The first step is a risk-based reliability method (RBRM) that accounts for the probability of a line outage versus the severity of impact. This allows system planners to judiciously allocate expenses for reliability improvements based on the greatest economic …

A Silicon Germanium Cmos Linear Voltage Regulator For Wireless Agricultural Applications, Aminta Naidili Castillo Robles

Graduate Theses and Dissertations

This thesis presents the design, simulation and test results of a silicon germanium (SiGe) complementary metal-oxide-semiconductor (CMOS) linear regulator. The objective of the circuit is to power other analog devices regardless of the load current and input voltage changes. The application of this regulator is to be part of a project developing a miniaturized semiconductor platform that can be inserted into stems of crops in order to measure data inside the plant and then send it wirelessly to the user. The linear regulator was designed on a BiCMOS SiGe 0.13µm which is a GlobalFoundries process. It has been tested at …

Local And Central Controllers For Microgrids, Edgar Ariel Escala Calame

Graduate Theses and Dissertations

The main objective of this thesis is to serve as a guide, so readers are able to learn about microgrids and to design simple controllers for different AC microgrid applications. In addition, this thesis has the objective to provide examples of simulation cases for the hierarchical structure of a basic AC microgrid which can be used as a foundation to build upon, and achieve more complex microgrid structures as well as more sophisticated power-converter control techniques.

To achieve these objectives, the modeling of voltage source converters and control design in the z-domain are presented. Moreover, the implementation and transient analysis …

Model Development And Assessment Of The Gate Network In A High-Performance Sic Power Module, William Austin Curbow

Graduate Theses and Dissertations

The main objective of this effort is to determine points of weakness in the gate network of a high-performance SiC power module and to offer remedies to these issues to increase the overall performance, robustness, and reliability of the technology. In order to accomplish this goal, a highly accurate model of the gate network is developed through three methods of parameter extraction: calculation, simulation, and measurement. A SPICE model of the gate network is developed to analyze four electrical issues in a high-speed, SiC-based power module including the necessary internal gate resistance for damping under-voltage and over-voltage transients, the disparity …

Synchrophasor-Based Fault Location Detection And Classification, In Power Systems, Using Artificial Intelligence, Hemal Falak

Graduate Theses and Dissertations

With the introduction of sophisticated electronic gadgets which cannot sustain interruption in the provision of electricity, the need to supply uninterrupted and reliable power supply, to the consumers, has become a crucial factor in the present-day world. Therefore, it is customary to correctly identify fault locations in an electrical power network, in order to rectify faults and restore power supply in the minimum possible time. Many automated fault location detection algorithms have been proposed, however, prior art requires topological and physical information of the electrical power network. This thesis presents a new method of detecting fault locations, in transmission as …

Development Of A Rapid Fatigue Life Testing Method For Reliability Assessment Of Flip-Chip Solder Interconnects, Cody Jackson Marbut

Graduate Theses and Dissertations

The underlying physics of failure are critical in assessing the long term reliability of power packages in their intended field applications, yet traditional reliability determination methods are largely inadequate when considering thermomechanical failures. With current reliability determination methods, long test durations, high costs, and a conglomerate of concurrent reliability degrading threat factors make effective understanding of device reliability difficult and expensive. In this work, an alternative reliability testing apparatus and associated protocol was developed to address these concerns; targeting rapid testing times with minimal cost while preserving fatigue life prediction accuracy. Two test stands were fabricated to evaluate device reliability …

Automatic Performance Optimization On Heterogeneous Computer Systems Using Manycore Coprocessors, Chenggang Lai

Graduate Theses and Dissertations

Emerging computer architectures and advanced computing technologies, such as Intel’s Many Integrated Core (MIC) Architecture and graphics processing units (GPU), provide a promising solution to employ parallelism for achieving high performance, scalability and low power consumption. As a result, accelerators have become a crucial part in developing supercomputers. Accelerators usually equip with different types of cores and memory. It will compel application developers to reach challenging performance goals. The added complexity has led to the development of task-based runtime systems, which allow complex computations to be expressed as task graphs, and rely on scheduling algorithms to perform load balancing between …

Investigation Of A Gan-Based Power Supply Topology Utilizing Solid State Transformer For Low Power Applications, Akrem Mohamed Elrajoubi

Graduate Theses and Dissertations

Gallium nitride (GaN) power devices exhibit a much lower gate capacitance for a similar on-resistance than its silicon counterparts, making it highly desirable for high-frequency operation in switching converters, which leads to their significant benefits on power density, cost, and system volume. High-density switching converters are being realized with GaN power devices due to their high switching speeds that reduce the size of energy-storage circuit components. The purpose of this dissertation research is to investigate a new isolated GaN AC/DC switching converter based on solid-state transformer configuration with a totem-pole power factor corrector (PFC) front-end, a half-bridge series-resonant converter (SRC) …

Intelligent Application Of Flexible Ac Transmission System Components In An Evolving Power Grid, Robert Wall

Graduate Theses and Dissertations

The world revolves around energy and the energy sector is continually transforming and evolving. The status quo has been set by governing agencies in the United States for completely reliable power. The demand for energy efficiency continually rises for multiple reasons. Technology has improved for all sectors of the power grid, including renewable energy sources, fault protection, and SMART grid technology. The addition of new energy sources has led to the decommissioning of inefficient energy sources. The implementation of new technologies and power load on a large scale, coupled with the removal of grid stabilizers has posed different challenges that …

Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter, Kenneth Mordi

Graduate Theses and Dissertations

This thesis compares the performance of a nine-level transformerless cascaded H-bridge (CHB) inverter with integrated battery energy storage system (BESS) using SiC power MOSFETs and Si IGBTs. Two crucial performance drivers for inverter applications are power loss and efficiency. Both of these are investigated in this thesis. Power devices with similar voltage and current ratings are used in the same inverter topology, and the performance of each device is analyzed with respect to switching frequency and operating temperature. The loss measurements and characteristics within the inverter are discussed. The Saber® simulation software was used for the comparisons. The power MOSFET …

Sustainability Of Utilizing Renewable And Nuclear Energy In Saudi Arabia Using Different Types Of Life Cycle Assessment, Kamel Almutairi

Graduate Theses and Dissertations

Evaluating the global environmental impacts of the current and future energy policies in Saudi Arabia using Life cycle assessment (LCA) method was the main objective of this dissertation. First, the attributional life cycle assessment (ALCA) framework was used to evaluate the Saudi’s air conditioning systems, as they are responsible for about 70% of the total Saudi residential electricity consumption. The ALCA’s results showed that the AC use phase produces the largest share of the environmental impact and the magnitude of the environmental impacts is influenced by the type of primary fuel used for electricity generation.

Emerging non-fossil sources of electricity …

Efficacy Of Multi-Threshold Null Convention Logic In Low-Power Applications, Brent Bell

Graduate Theses and Dissertations

In order for an asynchronous design paradigm such as Multi-Threshold NULL Convention Logic (MTNCL) to be adopted by industry, it is important for circuit designers to be aware of its advantages and drawbacks especially with respect to power usage. The power tradeoff between MTNCL and synchronous designs depends on many different factors including design type, circuit size, process node, and pipeline granularity. Each of these design dimensions influences the active power and the leakage power comparisons. This dissertation analyzes the effects of different design dimensions on power consumption and the associated rational for these effects. Results show that while MTNCL …

Fabrication And Characterization Of Graphene Based 2d Materials For Supercapacitors, Anishkumar Manoharan

Graduate Theses and Dissertations

Supercapacitors have attracted a lot attention due to their efficient energy storage. In comparison to batteries, supercapacitors have high capacitance, energy, and power densities per unit mass than conventional capacitors. Carbon based materials are most promising in supercapacitor application due to their outstanding physical and electrochemical behavior. In this work, a facile method to synthesize a nanocomposite electrode consisting of annealed carbon from carbon ink and MoS2 was demonstrated. Effects of various aqueous and solid electrolytes were studied. It was found that the nanocomposite electrode with 10% MoS2 and 1M Na2SO4 as the aqueous electrolyte tested using the three electrode …

Gating Methods For High-Voltage Silicon Carbide Power Mosfets, Audrey Dearien

Graduate Theses and Dissertations

The objective of this thesis is to assess the challenges associated with driving Silicon Carbide (SiC) power devices, and to compare the potential gate drive methods for these devices which address those challenges. SiC power devices present many benefits that make them suitable for next generation automotive, power utility grid, and energy management applications. High efficiency, increased power density, and reliability at high-temperatures are some of the main benefits of SiC technology. However, the many challenges associated with these devices have prevented their adoption into industry applications. The argument is made in this thesis that the gate driver is a …

A Silicon Carbide Power Management Solution For High Temperature Applications, Robert Murphree

Graduate Theses and Dissertations

The increasing demand for discrete power devices capable of operating in high temperature and high voltage applications has spurred on the research of semiconductor materials with the potential of breaking through the limitations of traditional silicon. Gallium nitride (GaN) and silicon carbide (SiC), both of which are wide bandgap materials, have garnered the attention of researchers and gradually gained market share. Although these wide bandgap power devices enable more ambitious commercial applications compared to their silicon-based counterparts, reaching their potential is contingent upon developing integrated circuits (ICs) capable of operating in similar environments.

The foundation of any electrical system is …

Power Interface Design And System Stability Analysis For 400 V Dc-Powered Data Centers, Yuzhi Zhang

Graduate Theses and Dissertations

The demands of high performance cloud computation and internet services have increased in recent decades. These demands have driven the expansion of existing data centers and the construction of new data centers. The high costs of data center downtime are pushing designers to provide high reliability power supplies. Thus, there are significant research questions and challenges to design efficient and environmentally friendly data centers with address increasing energy prices and distributed energy developments.

This dissertation work aims to study and investigate the suitable technologies of power interface and system level configuration for high efficiency and reliable data centers.

A 400 …

Energy Shaping Control For Stabilization Of Interconnected Voltage Source Converters In Weakly-Connected Ac Microgrid Systems, Nadia Lenora Carmita Smith

Graduate Theses and Dissertations

With the ubiquitous installations of renewable energy resources such as solar and wind, for decentralized power applications across the United States, microgrids are being viewed as an avenue for achieving this goal. Various independent system operators and regional transmission operators such as Southwest Power Pool (SPP), Midcontinent System Operator (MISO), PJM Interconnection and Electric Reliability Council of Texas (ERCOT) manage the transmission and generation systems that host the distributed energy resources (DERs). Voltage source converters typically interconnect the DERs to the utility system and used in High voltage dc (HVDC) systems for transmitting power throughout the United States. A microgrid …

The Development Of Novel Interconnection Technologies For 3d Packaging Of Wire Bondless Silicon Carbide Power Modules, Sayan Seal

Graduate Theses and Dissertations

This dissertation advances the cause for the 3D packaging and integration of silicon carbide power modules. 3D wire bondless approaches adopted for enhancing the performance of silicon power modules were surveyed, and their merits were assessed to serve as a vision for the future of SiC power packaging. Current efforts pursuing 3D wire bondless SiC power modules were investigated, and the concept for a novel SiC power module was discussed. This highly-integrated SiC power module was assessed for feasibility, with a focus on achieving ultralow parasitic inductances in the critical switching loops. This will enable higher switching frequencies, leading to …

A Low Temperature Co-Fired Ceramic (Ltcc) Interposer Based Three-Dimensional Stacked Wire Bondless Power Module, Atanu Dutta

Graduate Theses and Dissertations

The objective of this dissertation research is to develop a low temperature co-fired ceramic (LTCC) interposer-based module-level 3-D wire bondless stacked power module. As part of the dissertation work, the 3-D wire bondless stack is designed, simulated, fabricated and characterized. The 3-D wire bondless stack is realized with two stand-alone power modules in a half-bridge configuration. Each stand-alone power module consists of two 1200 V 25 A silicon insulated-gate bipolar transistor (IGBT) devices in parallel and two 1200 V 20 A Schottky barrier diodes (SBD) in an antiparallel configuration. A novel interconnection scheme with conductive clamps and a spring loaded …

Realization Of A High Power Microgrid Based On Voltage Source Converters, Yusi Liu

Graduate Theses and Dissertations

Microgrid concepts are gradually becoming more popular because they are expected to interface with renewable energies, increase end users’ reliability and resiliency, and promote seamless integration of distributed generators (DG) and energy storage units [1]. Most units are connected through power electronics interfaces, such as ac-dc, dc-dc, and dc-ac converters. The converter design and control are critical to the stability and efficiency of a microgrid.

A microgrid may operate in either gird connected mode or islanded mode [1]. In terms of stability, the grid connected mode is less challenging compared to the islanded mode of operation due to the nearly …

Reduction In Recombination Current Density In Boron Doped Silicon Using Atomic Hydrogen, Matthew Garett Young

Graduate Theses and Dissertations

The solar industry has grown immensely in recent years and has reached a point where solar energy has now become inexpensive enough that it is starting to emerge as a mainstream electrical generation source. However, recent economic analysis has suggested that for solar to become a truly wide spread source of electricity, the costs still need to plummet by a factor of 8x. This demands new and innovative concepts to help lower such cost. In pursuit of this goal, this dissertation examines the use of atomic hydrogen to lessen the recombination current density in the boron doped region of n-type …

Linear Quadratic Optimal Control For A Cascaded Converters-Based Microgrid, Amlam Niragire

Graduate Theses and Dissertations

There is a constant transformation of the electric grid due to an ongoing interest in the deployment of renewable energy resources and electric microgrid formation. This transformation, though advantageous in many ways, poses great challenges for the energy industry and there must be a constant improvement in modeling, simulation, analysis and control techniques in order to characterize and optimize the system design and operation. In this light, the scope of this thesis is focused on developing a linear model, analyzing the stability and designing an optimal linear quadratic regulator (LQR) for a microgrid system. The microgrid system used is inspired …

Applications Of Krylov Subspace And Balanced Truncation Model Order Reduction In Power Systems, Sebastian Emanuel Garrido

Graduate Theses and Dissertations

Dynamic representations of power systems usually result in the order of hundreds or even thousands of buses. Therefore, reduction of these dynamic representations is convenient. Two applications of model order reduction in power systems are discussed in this thesis. First, Krylov subspace-based method is applied to the IEEE-123 Node Test Feeder in the context of distribution-level power systems simulation. Second, a Balanced Truncation-based model reduction is implemented in the 3-Machine 9-Bus system for designing a power system controller in the context of generation- and transmission-level power systems.

First, for the IEEE-123 Node Test Feeder, a two-sided Arnoldi algorithm is proposed …

Selective Resistive Sintering: A Novel Additive Manufacturing Process, Austin Bryan Van Horn

Graduate Theses and Dissertations

Selective laser sintering (SLS) is one of the most popular 3D printing methods that uses a laser to pattern energy and selectively sinter powder particles to build 3D geometries. However, this printing method is plagued by slow printing speeds, high power consumption, difficulty to scale, and high overhead expense. In this research, a new 3D printing method is proposed to overcome these limitations of SLS. Instead of using a laser to pattern energy, this new method, termed selective resistive sintering (SRS), uses an array of microheaters to pattern heat for selectively sintering materials. Using microheaters offers significant power savings, significantly …