Engineering Commons^™

Electromechanics Of An Ocean Current Turbine, Vasileios Tzelepis

University of New Orleans Theses and Dissertations

The development of a numeric simulation for predicting the performance of an Ocean Current Energy Conversion System is presented in this thesis along with a control system development using a PID controller for the achievement of specified rotational velocity set-points. In the beginning, this numeric model is implemented in MATLAB/Simulink® and it is used to predict the performance of a three phase squirrel single-cage type induction motor/generator in two different cases. The first case is a small 3 meter rotor diameter, 20 kW ocean current turbine with fixed pitch blades, and the second case a 20 …

Three-Phase Power Converter Based Real-Time Synchronous Generator Emulation, Liu Yang

Doctoral Dissertations

To bridge the gap between power system research and their real application in power grids, a Hardware Test-Bed (HTB) with modular three-phase power converters has been developed at the CURENT center, the University of Tennessee, Knoxville, to emulate transmission level power systems with actual power flowing.

This dissertation focuses on the development and verification of a real-time synchronous generator (SG) emulator in the HTB. The research involved in this dissertation aims at designing a proper control to achieve emulator performance goal and investigating the sources of error and its influence on interconnected SG-emulator networks.

First, different interface algorithms (IAs) are …

Energy-Efficient And Power-Dense Dc-Dc Converters In Data Center And Electric Vehicle Applications Using Wide Bandgap Devices, Weimin Zhang

Doctoral Dissertations

The ever increasing demands in the energy conversion market propel power converters towards high efficiency and high power density. With fast development of data processing capability in the data center, the server will include more processors, memories, chipsets and hard drives than ever, which requires more efficient and compact power converters. Meanwhile, the energy-efficient and power-dense converters for the electric vehicle also result in longer driving range as well as more passengers and cargo capacities. DC-DC converters are indispensable power stages for both applications. In order to address the efficiency and density requirements of the DC-DC converters in these applications, …

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 …

Incentive Based Residential Demand Aggregation, Qinran Hu

Doctoral Dissertations

From the beginning of the twenty-first century, the electrical power industry has moved from traditional power systems toward smart grids. However, with the increasing amount of renewable energy resources integrated into the grid, there is a significant challenge in power system operation due to the intermittency and variability of the renewables. Therefore, the utilization of flexible and controllable demand-side resources to maintain power system efficiency and stability has become a fundamental goal of smart grid initiatives.

Meanwhile, due to the development of communication and sensing technologies, intelligent demand-side management with automatic controls enables residential loads to participate in demand response …

Using Gpu To Accelerate Linear Computations In Power System Applications, Xue Li

Doctoral Dissertations

With the development of advanced power system controls, the industrial and research community is becoming more interested in simulating larger interconnected power grids. It is always critical to incorporate advanced computing technologies to accelerate these power system computations. Power flow, one of the most fundamental computations in power system analysis, converts the solution of non-linear systems to that of a set of linear systems via the Newton method or one of its variants. An efficient solution to these linear equations is the key to improving the performance of power flow computation, and hence to accelerating other power system applications based …

Gain Tuning Of Proportional Integral Controller Based On Multiobjective Optimization And Controller Hardware-In-Loop Microgrid Setup, Kumaraguru Prabakar

Doctoral Dissertations

Proportional integral (PI) control is a commonly used industrial controller framework. This PI controller needs to be tuned to obtain desired response from the process under control. Tuning methods available in literature by and large need sophisticated mathematical modelling, and simplifications in the plant model to perform gain tuning. The process of obtaining approximate plant model conceivably become time consuming and produce less accurate results. This is due to the simplifications desired by the power system applications especially when power electronics based inverters are used in it. Optimal gain selection for PI controllers becomes crucial for microgrid application. Because of …

Power Protection Analysis For A Ten Bus System, Sean Hanna

Electrical Engineering

Each power system built in the industry requires a protection plan. Undetected faults in a power system can contribute to hazardous conditions, overheating of power devices, low or high system voltages, unbalanced conditions, and blackouts. This senior project is the design of a protection plan for a power system using the software Electric Transient Analyzer Program (ETAP). With ten buses, five transformers, two generators, two motors, and six transmission lines, there are many possibilities for a fault to occur. The Load flow and fault analysis are studied before the system is protected. All components of the system are protected using …

Dual-Input Dc-To-Dc Converter Topologies And Control Schemes, Shaun Alan Stickel

Boise State University Theses and Dissertations

Dual-input DC-to-DC converters are power supplies that draw power from two sources simultaneously and deliver power to a single load, the ratio of power drawn from each source and be held constant with changes in the load. Applications for dual-input power supplies are computer systems, mobile systems using energy harvesting, and systems needing redundant power supplies. This writing covers the operation and control of dual-input DC-to-DC converters that implement a non-inverting buck-boost function and utilize only a single power path.

Traditionally, a dual-input power supply is created by placing two standard power paths in parallel. This adds considerable control complexity …

Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar

Graduate Theses and Dissertations

Energy security through increased biofuel production is one of the components of the Energy Independence and Security Act (EISA) 2007. As per EISA 2007 mandate, appropriate independent research institutes are required to assess concerns to natural biodiversity due to biofuel production and report it to the Congress through the Environment Protection Agency (EPA). Planners, researchers, and agencies concerned with environmental regulations, ideally, would like to have location-specific information about the impacts for developing appropriate management interventions. This study examines long-term impacts on water quality in response to targeted (i.e. marginal lands) production of biofuel crops by setting up two SWAT …

Utilization Of High Efficient Single Phase Motor, Kevin Hua

Electrical Engineering

A Smith Motor is a three phase induction motor that has shunt capacitors parallel to its induction coils. The shunt capacitors provide balance and allow the motor to operate using a single phase power supply. Preliminary studies show that the Smith Motor is more efficient than a single phase induction motor powered by a single phase power supply, but less efficient than a three phase induction motor powered by a three phase power supply. The Smith Motor’s advantage is its ability to operate from a single phase power source instead of having a three phase power source installed. Its limitation …

Design And Control Of A Bidirectional Dual Active Bridge Dc-Dc Converter To Interface Solar, Battery Storage, And Grid-Tied Inverters, Kenny George

Electrical Engineering Undergraduate Honors Theses

In order to further reduce the size of today’s power converters, wide bandgap semiconductor technologies are being explored. These devices, such as silicon carbide (SiC), have been shown to outperform their silicon counterparts when used in high frequency switching, high temperature, and high voltage applications. These properties make them highly desirable in the bidirectional dual active bridge power converter. Being an isolated converter topology, the dual active bridge employs a transformer to provide step-up/step-down functionality and galvanic isolation for the converter. Transformers, as well as other passive components such as inductors and capacitors may be reduced in size when higher …

Industrial Energy Consumption, Benchmarking, And Analysis In The United States, Daniel Maldonado

Mechanical Engineering Undergraduate Honors Theses

The purpose of this paper is to analyze the energy consumption of the industrial sector in the United States, and to identify the tools that can be used to minimize the consumption and improve the energy efficiency of all facilities in the country. The first part of the paper is a historical analysis of the industrial sector energy consumption, where the different energy sources are identified. The second part details different electronic tools that will provide facilities the ability of performing benchmarking, in order to understand their energy performance. Finally, the third part of this paper provides information about the …

Model Development And Validation For Wind Generation Transmission Systems, Mahmood Shihadeh Saadeh

Graduate Theses and Dissertations

In this research a new benchmark system is proposed for wind energy transmission systems. New model development, validation, and calibration methods for power transmission systems are proposed and implemented as well. First, a model reduction criteria is chosen based on electrical interconnection and geographical information. Model development is then done using reduction techniques on an operation model provided by a transmission operator based on the chosen criteria. Then model validation is performed using actual PMU synchrophasor measurements provided by a utility company. The model development and validation process ensures the accuracy of the developed model and makes for a realistic …

High Temperature Silicon Carbide Mixed-Signal Circuits For Integrated Control And Data Acquisition, Ashfaqur Rahman

Graduate Theses and Dissertations

Wide bandgap semiconductor materials such as gallium nitride (GaN) and silicon carbide have grown in popularity as a substrate for power devices for high temperature and high voltage applications over the last two decades. Recent research has been focused on the design of integrated circuits for protection and control in these wide bandgap materials. The ICs developed in SiC and GaN can not only complement the power devices in high voltage and high frequency applications, but can also be used for standalone high temperature control and data acquisition circuitry.

This dissertation work aims to explore the possibilities in high temperature …

High-Frequency Transformer Design For Solid-State Transformers In Electric Power Distribution Systems, Roderick Javier Garcia Montoya

Graduate Theses and Dissertations

The objective of this thesis is to present a high- or medium-frequency transformer design methodology for Solid-State Transformer (SST) applications. SSTs have been proposed as a replacement of the traditional 50/60 Hz transformer in applications demanding high-power density. Moreover, due to the high penetration of distributed generation, DC grids, energy storage systems, and sensitive loads, SSTs have been considered as an enabling technology for envisioned future energy systems. These applications demand additional functionalities that may not be achieved with traditional transformers. For example, active power flow control, harmonic suppression, voltage regulation, voltage sag compensation, and reduced size and volume.

In …

A Combined Energy And Geoengineering Optimization Model (Ceagom) For Climate Policy Analysis, John George Anasis

Dissertations and Theses

One of the greatest challenges that will face humanity in the 21^st century is the issue of climate change brought about by emissions of greenhouse gases. Energy use is one of the primary sources of greenhouse gas emissions. However, it is also one of the most important contributors to improved human welfare over the past two centuries and will continue to be so for years to come. This quandary has led a number of researchers to suggest that geoengineering may be required in order to allow for continued use of fossil fuels while at the same time mitigating the …

Adaptive Single-Phase Reclosing In Transmission Lines, Farzad Zhalefar

Electronic Thesis and Dissertation Repository

This research work is mainly concerned about dealing with temporary short circuit faults in power system transmission lines. In fact, there are two types of electrical faults in power systems, namely temporary and permanent. When a fault is permanent, the only way to clear it is to de-energize the transmission line by opening the associated circuit breakers. However, in many cases the fault is not solid and is caused by objects such as flying birds or broken branches of trees. For these cases, electrical arc plays a major role. For such fault cases, it is also possible to de-energize the …

Bidirectional Ac-Dc Converter For Vehicle-To-Grid (V2g) Applications, Arjun Raj Prabu Andhra Sridhar

Master's Theses (2009 -)

Electric vehicles are growing at a rapid pace in the internal combustion engine dominated transportation sector, and bring environmental and economic benefits to society. Electric vehicles produce nearly zero carbon emission, provided that they are charged through renewable energy sources. Electric vehicles reduce our dependency on foreign oil and also offer additional benefits like Vehicle-to-grid (V2G). V2G is a technology that allows electric energy stored in the electric vehicle batteries to be returned to the grid during peak demand. V2G can also provide voltage regulation, voltage shaving, reactive power compensation and distributed generation. This necessitates that an electric vehicle battery …

Modeling, Construction, And Validation Of A Simulator For A Nuclear Process Control Test Facility, Binggang Cui

Electronic Thesis and Dissertation Repository

This thesis presents the modeling, construction, and validation of a software simulator for a facility with physical components, referred to as NPCTF (Nuclear Process Control Test Facility). The simulator focuses simulation functionalities on dynamic behaviours of thermal-hydraulic systems related to nuclear power plants.

The modeling techniques adopted to construct the simulator are based on physical principles. Dynamic models are developed to reproduce the dynamic characteristics of NPCTF. Based on these mathematical relationships, computer codes are developed with the toolbox Simscape. The simulator can be used to investigate specific scenarios of NPCTF under similar operating conditions.

A simulation environment, the toolbox …

Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, Mohammadreza Ghazanchaei

Electronic Thesis and Dissertation Repository

One of the main goals of applied electrostatics engineering is to discover new perspectives in a wide range of research areas. Controlling the fluid media through electrostatic forces has brought new important scientific and industrial applications. Electric field induced flows, or electrohydrodynamics (EHD), have shown promise in the field of fluid dynamics. Although numerous EHD applications have been explored and extensively studied so far, most of the works are either experimental studies, which are not capable to explain the in depth physics of the phenomena, or detailed analytical studies, which are not time effective. The focus of this study is …

Modeling And Test Of The Efficiency Of Electronic Speed Controllers For Brushless Dc Motors, Clayton R. Green

Master's Theses

Small electric uninhabited aerial vehicles (UAV) represent a rapidly expanding market requiring optimization in both efficiency and weight; efficiency is critical during cruise or loiter where the vehicle operates at part power for up to 99% of the mission time. Of the four components (battery, motor, propeller, and electronic speed controller (ESC)) of the electric propulsion system used in small UAVs, the ESC has no accepted performance model and almost no published performance data. To collect performance data, instrumentation was developed to measure electrical power in and out of the ESC using the two wattmeter method and current sense resistors; …

Research On The Application Of Solar Photovoltaic System On Large Ocean-Going Ships, Wanhe Huang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Real Time Testing And Validation Of A Novel Short Circuit Current (Scc) Controller For A Photovoltaic Inverter, Vishwajitsinh H. Atodaria

Electronic Thesis and Dissertation Repository

About 45% applications from PV solar farm developers seeking connections to the distribution grids in Ontario were denied in 2011-13 as the short circuit current (SCC) capacity of several distribution substations had already been reached. PV solar system inverters typically contribute 1.2 p.u. to 1.8 p.u. fault current which was not considered acceptable by utility companies due to the need for very expensive protective breaker upgrades. Since then, this cause has become a major impediment in the growth of PV based renewable systems in Ontario.

A novel predictive technique has been patented in our research group for management of short …

Smart Pv Inverter Control For Distribution Systems, Ehsan M. Siavashi

Electronic Thesis and Dissertation Repository

PV solar systems employ inverters to transform dc power from solar panels into ac power for injecting into the power grids. Inverters that perform multiple functions in addition to real power production are known as “smart inverters”.

This thesis presents a novel control of PV inverter as a dynamic reactive power compensator – STATCOM. This “smart PV inverter” control enables a PV solar inverter to operate in three modes – i) Full PV, ii) Partial STATCOM, and iii) Full STATCOM, depending upon system needs. The novel control is developed and demonstrated for the objectives of a) symmetrical voltage regulation, b) …

Adaptive Online Transient Stability Assessment Of Power Systems For Operational Purposes, Hussain Hassan Al Marhoon

University of New Orleans Theses and Dissertations

Online stability assessment is an important problem that has not been solved completely yet. The purpose of this research is to tackle online transient stability assessment. Currently, most utility companies use step-by-step integration in order to set protective equipment so that they effectively work for critical contingencies. However, there are times an unforeseen contingency may occur which may cause the system to transit and the protective equipment to misoperate and does not isolate the disturbed part of the system. This research introduces a method that automatically determines a group of generators that participate in system separation and hence transient instability. …

A 3rd Generation Frequency Disturbance Recorder: A Secure, Low Cost Synchophasor Measurement Device, Jerel Alan Culliss

Doctoral Dissertations

The Frequency Monitoring Network (FNET) is a wide-area phasor measurement system developed in 2003. It collects power system data using embedded devices known as Frequency Disturbance Recorders (FDRs) which are installed at distribution level voltages. These devices are single-phase synchrophasor measurement units which share a number of common attributes with their commercial counterparts.

Phasor measurements from FDRs across North America and other power grids around the world are transmitted over the Internet back to the FNET servers at the University of Tennessee. By analyzing the fluctuations in the grid’s frequency, FNET can identify disruptive events relating to the operation of …

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, …

Characterization And Realization Of High Switching-Speed Capability Of Sic Power Devices In Voltage Source Converter, Zheyu Zhang

Doctoral Dissertations

The emerging wide band-gap, silicon carbide (SiC) power devices greatly improve the switching performance due to their inherent fast switching capability. However, the high switching-speed performance makes their switching behavior become more susceptible to parasitics of the application circuit. In the end, unlike the excellent switching performance of SiC devices tested in manufacturer’ datasheets, the observed switching performance in actual power converters is almost always worse. This dissertation aims at characterization and realization of high switching-speed capability of SiC devices in one of the most widely used converter types, the voltage source converter (VSC).

To evaluate the fast dynamic characteristics …

Driving And Protection Of High Density High Temperature Power Module For Electric Vehicle Application, Zhiqiang Wang

Doctoral Dissertations

There has been an increasing trend for the commercialization of electric vehicles (EVs) to reduce greenhouse gas emissions and dependence on petroleum. However, a key technical barrier to their wide application is the development of high power density electric drive systems due to limited space within EVs. High temperature environment inherent in EVs further introduces a new level of complexity. Under high power density and high temperature operation, system reliability and safety also become important.

This dissertation deals with the development of advanced driving and protection technologies for high temperature high density power module capable of operating under the harsh …