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Full-Text Articles in Electrical and Electronics

Power System Electromagnetic Transient Simulation Using A Semi-Analytical Approach, Min Xiong May 2024

Power System Electromagnetic Transient Simulation Using A Semi-Analytical Approach, Min Xiong

Doctoral Dissertations

This dissertation investigates efficient power system electromagnetic transient (EMT) simulations using a semi-analytical approach.

First, based on state-space equations of system EMT models, a semi-analytical solution (SAS) is acquired using the Differential Transformation Method (DTM). The DTM can efficiently derive the SAS of any linear or nonlinear system as a power series in time in a recursive manner using well-developed transformation rules. A high-order SAS allows a large time step to speed up the simulation while maintaining the same level of accuracy. Also, a variable time step approach is proposed to further improve its efficiency. Case studies on multiple systems …


Static And Dynamic State Estimation Applications In Power Systems Protection And Control Engineering, Ibukunoluwa Olayemi Korede Dec 2023

Static And Dynamic State Estimation Applications In Power Systems Protection And Control Engineering, Ibukunoluwa Olayemi Korede

Doctoral Dissertations

The developed methodologies are proposed to serve as support for control centers and fault analysis engineers. These approaches provide a dependable and effective means of pinpointing and resolving faults, which ultimately enhances power grid reliability. The algorithm uses the Least Absolute Value (LAV) method to estimate the augmented states of the PCB, enabling supervisory monitoring of the system. In addition, the application of statistical analysis based on projection statistics of the system Jacobian as a virtual sensor to detect faults on transmission lines. This approach is particularly valuable for detecting anomalies in transmission line data, such as bad data or …


Fourier Analysis And Optimization Of Inductive Wireless Power Transfer For Electric Vehicle Charging, Andrew P. Foote Dec 2023

Fourier Analysis And Optimization Of Inductive Wireless Power Transfer For Electric Vehicle Charging, Andrew P. Foote

Doctoral Dissertations

With the growth of electric vehicle (EV) popularity, different charging options to increase user convenience and reduce charging time such as high power wireless charging are increasingly being developed and researched. Inductive wireless power transfer (WPT) systems for EVs must meet specifications such as stray field, battery power and voltage operating range, efficiency, and ground clearance. The coil geometry and design have a large impact in meeting these constraints. Typical design approaches include iterative analysis of predetermined coil geometries to identify candidates that meet these constraints.

This work instead directly generates WPT coil shapes and magnetic fields to meet specifications …


Reducing The Levelized Cost Of Energy Of Residential Pv Inverters Through Dynamic Hardware Allocation, Kamal Sabi May 2023

Reducing The Levelized Cost Of Energy Of Residential Pv Inverters Through Dynamic Hardware Allocation, Kamal Sabi

Doctoral Dissertations

Renewable energy, such as wind and solar are becoming an integral part of world energy production. Photovoltaic (PV) systems are projected to constitute a large portion of the energy generation portfolio. Achieving a low-cost residential PV system will enable the wide adoption of solar energy throughout the USA. Although innovation in several areas is required to achieve this goal of a low-cost residential PV system, inverter reliability innovation is one key area that is essential. Present string inverters' lifetime is less than 15 years. Increasing their lifetime to 50 years will reduce the cost of operation and maintenance, increase energy …


Multiple Objective Co-Optimization Of Switched Reluctance Machine Design And Control, Timothy Burress May 2023

Multiple Objective Co-Optimization Of Switched Reluctance Machine Design And Control, Timothy Burress

Doctoral Dissertations

This dissertation includes a review of various motor types, a motivation for selecting the switched reluctance motor (SRM) as a focus of this work, a review of SRM design and control optimization methods in literature, a proposed co-optimization approach, and empirical evaluations to validate the models and proposed co-optimization methods.

The switched reluctance motor (SRM) was chosen as a focus of research based on its low cost, easy manufacturability, moderate performance and efficiency, and its potential for improvement through advanced design and control optimization. After a review of SRM design and control optimization methods in the literature, it was found …


Analysis And Development Of Multiple Phase Shift Modulation In A Sic-Based Dual Active Bridge Converter, Yu Yan Aug 2022

Analysis And Development Of Multiple Phase Shift Modulation In A Sic-Based Dual Active Bridge Converter, Yu Yan

Doctoral Dissertations

Renewable energy adoption is a popular topic to release the stress of climate change caused by greenhouse gas. Electricity is ideal secondary energy for clean primary energy such as nuclear, wind, photovoltaic, and so on. To extend the application of electricity and reduce fossil energy consumption by transportation sectors, electric vehicles (EVs) become promising technology that can further inspire the development of renewable energy.

Battery as the core in an EV provides the energy to the motor and all on-board electric equipment. The battery charger is mainly composed of a power factor correction (PFC) and isolated DC-DC converter. Therefore, power …


Power Quality Control And Common-Mode Noise Mitigation For Inverters In Electric Vehicles, Yang Huang Aug 2022

Power Quality Control And Common-Mode Noise Mitigation For Inverters In Electric Vehicles, Yang Huang

Doctoral Dissertations

Inverters are widely utilized in electric vehicle (EV) applications as a major voltage/current source for onboard battery chargers (OBC) and motor drive systems. The inverter performance is critical to the efficiency of EV system energy conversion and electronics system electro-magnetic interference (EMI) design. However, for AC systems, the bandwidth requirement is usually low compared with DC systems, and the control impact on the inverter differential-mode (DM) and common-mode (CM) performance are not well investigated. With the wide-band gap (WBG) device era, the switching capability of power electronics devices drastically improved. The DM/CM impact that was brought by the WBG device-based …


Stability Analysis And Design Of Grid-Interactive Power Electronic Converters, Le Kong Aug 2022

Stability Analysis And Design Of Grid-Interactive Power Electronic Converters, Le Kong

Doctoral Dissertations

The increasing penetration of power electronic converters (PECs) can provide high flexibility, full controllability, sustainability, and improved efficiency for future electric power systems. However, it also introduces new challenges since the wide-frequency-band control dynamics of PECs can interact with the power system and result in different types of instability issues. To holistically address the instability issues, several research activities are conducted in this dissertation.

The modular multilevel converter (MMC), which is one of the most common PECs in high- or medium-voltage power systems, is investigated. An improved MMC dc impedance model is developed by considering both the submodule voltage and …


Load Modeling And Evaluation Of Leds For Hardware Test Bed Application, Jillian M. Ruff Aug 2022

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 …


Data Center Power System Emulation And Gan-Based High-Efficiency Rectifier With Reactive Power Regulation, Jingjing Sun May 2022

Data Center Power System Emulation And Gan-Based High-Efficiency Rectifier With Reactive Power Regulation, Jingjing Sun

Doctoral Dissertations

Data centers are indispensable for today's computing and networking society, which has a considerable power consumption and significant impact on power system. Meanwhile, the average energy usage efficiency of data centers is still not high, leading to significant power loss and system cost.

In this dissertation, effective methods are proposed to investigate the data center load characteristics, improve data center power usage efficiency, and reduce the system cost.

First, a dynamic power model of a typical data center ac power system is proposed, which is complete and able to predict the data center's dynamic performance. Also, a converter-based data center …


Modeling And Control Of A 7-Level Switched Capacitor Rectifier For Wireless Power Transfer Systems, Spencer Cochran Dec 2021

Modeling And Control Of A 7-Level Switched Capacitor Rectifier For Wireless Power Transfer Systems, Spencer Cochran

Doctoral Dissertations

Wireless power continues to increase in popularity for consumer device charging. Rectifier characteristics like efficiency, compactness, impedance tunability, and harmonic content make the multi-level switched capacitor rectifier (MSC) an exceptional candidate for modern WPT systems. The MSC shares the voltage conversion characteristics of a post-rectification buck-boost topology, reduces waveform distortion via its multi-level modulation scheme, demonstrates tank tunability via the phase control inherent to actively switched rectifiers, and accomplishes all this without a bulky filter inductor. In this work, the MSC WPT system operation is explained, and a loss model is constructed. A prototype system is used to validate the …


Partial Discharge Testing And Detection Under Pwm Voltage, John Meadors Dec 2021

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 …


Development Of A Converter-Based Testing Platform And Battery Energy Storage System (Bess) Emulator For Microgrid Controller Function Evaluation, Dingrui Li May 2021

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 …


Design Of Power Receiving Units For 6.78mhz Wireless Power Transfer Systems, Hoang Phuc Tran Pham Dec 2020

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 …


Modeling And Optimization Algorithm For Sic-Based Three-Phase Motor Drive System, Ren Ren Aug 2020

Modeling And Optimization Algorithm For Sic-Based Three-Phase Motor Drive System, Ren Ren

Doctoral Dissertations

More electric aircraft (MEA) and electrified aircraft propulsion (EAP) becomes the important topics in the area of transportation electrifications, expecting remarkable environmental and economic benefits. However, they bring the urgent challenges for the power electronics design since the new power architecture in the electrified aircraft requires many benchmark designs and comparisons. Also, a large number of power electronics converter designs with different specifications and system-level configurations need to be conducted in MEA and EAP, which demands huge design efforts and costs. Moreover, the long debugging and testing process increases the time to market because of gaps between the paper design …


Device Characterization Of Solar Inverters, Katelyn Alexandria Bolinsky May 2018

Device Characterization Of Solar Inverters, Katelyn Alexandria Bolinsky

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Solar energy is one of the most significant research thrusts in the modern era. Solar inverters are devices used to convert the DC energy of sunlight into AC energy that can be used on the power grid. Typically, they contain silicon; however, new substances such as silicon carbide and gallium nitride are being tested. These materials could increase the efficiency of solar energy, decrease the overall cost, and are potentially more durable than silicon. In order to determine if these new substances can actually benefit the solar industry, they need to be characterized for different attributes with different parameters. As …


Battery Energy Storage Emulation For Power System Applications, Jessica Danielle Boles Aug 2017

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 Aug 2017

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 …


Loss Model For Gallium Nitride Dc-Dc Buck Converter, Rushi P. Patel Jun 2017

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 …


Design And Implementation Of Power Electronics For An Electric Bicycle, Kyle Jackson Goodrick, Jared Baxter, Jacob Dyer May 2017

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.


Bi-Level Optimization Considering Uncertainties Of Wind Power And Demand Response, Xin Fang Aug 2016

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 …


Review And Characterization Of Gallium Nitride Power Devices, Edward Andrew Jones Aug 2016

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, …


Wide-Area Synchrophasor Measurement Applications And Power System Dynamic Modeling, Yin Lei Dec 2015

Wide-Area Synchrophasor Measurement Applications And Power System Dynamic Modeling, Yin Lei

Doctoral Dissertations

The use of synchrophasor measurements system-wide has been providing significant assistance for grid dynamic monitoring, situation awareness and reliability improvement. Frequency Monitoring Network (FNET), as an academia-run synchrophasor measurement system, utilizes a large number of Internet-connected low-cost Frequency Disturbance Recorders (FDRs) installed at the distribution level to measure power system dynamics and provide both online and off-line applications, such as event detection, oscillation modes estimation, event replay, etc. This work aims to further explore applications of the FNET measurements and utilize measurement-based method in dynamic modeling.

Measurement-based dynamic reduction is an important application of synchrophasor measurement, especially considering the fact …


Versatile Three-Phase Power Electronics Converter Based Real-Time Load Emulators, Jing Wang Aug 2015

Versatile Three-Phase Power Electronics Converter Based Real-Time Load Emulators, Jing Wang

Doctoral Dissertations

This dissertation includes the methodology, implementation, validation, as well as real-time modeling of a load emulator for a reconfigurable grid emulation platform of hardware test-bed (HTB). This test-bed was proposed by Center of Ultra-wide-area Resilient Electric Energy Transmission Network (CURENT) at the University of Tennessee, at Knoxville in 2011, to address the transmission level system challenges posed by contemporary fast changing energy technologies.

Detailed HTB introduction, including design concept, fundamental units and hardware construction, is elaborated. In the development, current controlled three-phase power electronics converter based emulator unit is adopted to create desired power system loading conditions.

In the application, …


Simulation Of A Smart Home Energy Management System With Dynamic Price Response, Jason Y. Chan, Qinran Hu Jun 2014

Simulation Of A Smart Home Energy Management System With Dynamic Price Response, Jason Y. Chan, Qinran Hu

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

With the continuing development of the smart grid combined with the fluctuating nature of the electricity market, the development of demand-side management with controllable loads have been greatly driven. With the amount of household loads in the residential sector, managing their energy usage has received lots of interest. This paper presents a simulation of a previously proposed hardware design of a smart home energy management system (SHEMS), focusing on the data collection and processing functions of the proposed design while implementing them onto standard household loads like an electric water heater and an electric vehicle charging station. It was found …


Vehicle-To-Grid (V2g) Reactive Power Operation Analysis Of The Ev/Phev Bidirectional Battery Charger, Mithat Can Kisacikoglu May 2013

Vehicle-To-Grid (V2g) Reactive Power Operation Analysis Of The Ev/Phev Bidirectional Battery Charger, Mithat Can Kisacikoglu

Doctoral Dissertations

More battery powered electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) will be introduced to the market in 2013 and beyond. Since these vehicles have large batteries that need to be charged from an external power source or directly from the grid, their charging circuits and grid interconnection issues are garnering more attention.

It is possible to incorporate more than one operation mode in a charger by allowing the power to flow bidirectionally. Usually, the bidirectional power transfer stands for two-way transfer of active power between the charger and the grid. The general term of sending active power from …


Real-Time Selective Harmonic Minimization For Multilevel Inverters Using Genetic Algorithm And Artificial Neural Network Angle Generation, Faete Jacques Teixeira Filho May 2012

Real-Time Selective Harmonic Minimization For Multilevel Inverters Using Genetic Algorithm And Artificial Neural Network Angle Generation, Faete Jacques Teixeira Filho

Doctoral Dissertations

This work approximates the selective harmonic elimination problem using Artificial Neural Networks (ANN) to generate the switching angles in an 11-level full bridge cascade inverter powered by five varying DC input sources. Each of the five full bridges of the cascade inverter was connected to a separate 195W solar panel. The angles were chosen such that the fundamental was kept constant and the low order harmonics were minimized or eliminated. A non-deterministic method is used to solve the system for the angles and to obtain the data set for the ANN training. The method also provides a set of acceptable …


Design And Control Of High Power Density Motor Drive, Dong Jiang Dec 2011

Design And Control Of High Power Density Motor Drive, Dong Jiang

Doctoral Dissertations

This dissertation aims at developing techniques to achieve high power density in motor drives under the performance requirements for transportation system. Four main factors influencing the power density are the main objects of the dissertation: devices, passive components, pulse width modulation (PWM) methods and motor control methods.

Firstly, the application of SiC devices could improve the power density of the motor drive. This dissertation developed a method of characterizing the SiC device performance in phase-leg with loss estimation, and claimed that with SiC Schottky Barrier Diode the advantage of SiC JFET could benefit the motor drive especially at high temperature. …


High Order Contingency Selection Using Particle Swarm Optimization And Tabu Search, Ashwini Chegu Aug 2010

High Order Contingency Selection Using Particle Swarm Optimization And Tabu Search, Ashwini Chegu

Masters Theses

There is a growing interest in investigating the high order contingency events that may result in large blackouts, which have been a great concern for power grid secure operation. The actual number of high order contingency is too huge for operators and planner to apply a brute-force enumerative analysis. This thesis presents a heuristic searching method based on particle swarm optimization (PSO) and tabu search to select severe high order contingencies. The original PSO algorithm gives an intelligent strategy to search the feasible solution space, but tends to find the best solution only. The proposed method combines the original PSO …