Engineering Commons^™

Predicting Voltage Abnormality Using Power System Dynamics, Nagendrakumar Beeravolu

University of New Orleans Theses and Dissertations

The purpose of this dissertation is to analyze dynamic behavior of a stressed power system and to correlate the dynamic responses to a near future system voltage abnormality. It is postulated that the dynamic response of a stressed power system in a short period of time-in seconds-contains sufficient information that will allow prediction of voltage abnormality in future time-in minutes. The PSSE dynamics simulator is used to study the dynamics of the IEEE 39 Bus equivalent test system. To correlate dynamic behavior to system voltage abnormality, this research utilizes two different pattern recognition methods one being algorithmic method known as …

Battery Energy Storage Systems To Mitigate The Variability Of Photovoltaic Power Generation, Heath Alan Gurganus

Dissertations and Theses

Methods of generating renewable energy such as through solar photovoltaic (PV) cells and wind turbines offer great promise in terms of a reduced carbon footprint and overall impact on the environment. However, these methods also share the attribute of being highly stochastic, meaning they are variable in such a way that is difficult to forecast with sufficient accuracy. While solar power currently constitutes a small amount of generating potential in most regions, the cost of photovoltaics continues to decline and a trend has emerged to build larger PV plants than was once feasible. This has brought the matter of increased …

Development Of Si Device Based Power Converters For High Temperature Operation In Hev Applications, Zhuxian Xu

Doctoral Dissertations

In this dissertation, the feasibility of operating Si devices at 200 ˚C [degree Celsius] is investigated and the guidelines on the development of a high temperature Si converter for operating with 105 ˚C high temperature liquid coolant in hybrid electrical vehicle (HEV) applications are provided.

First, the characterization of a Si IGBT operating at 200 ˚C junction temperatures is presented. It is shown that the commercial 175 ˚C Si IGBT under test can be successfully switched at an elevated junction temperature of 200 ˚C with increased but acceptable losses.

Second, a comprehensive evaluation of Si IGBT ruggedness at high temperature …

Wide-Area Measurement And Applications In Power System Dynamic Modeling And Control, Yong Liu

Doctoral Dissertations

Synchrophasor has been becoming the foundational element of power grid wide-area measurement system (WAMS) since first developed in 1980s. By utilizing global positioning system (GPS) time synchronization technique, synchrophasors offer highly accurate time-synchronized phasor measurements that can provide system operators with real-time information of operation status.

Frequency disturbance recorders (FDRs) are installed on the distribution level to measure power system dynamics and considered as a type of single-phase synchrophasors. In this dissertation, a detailed procedure for the FDRs’ calibration is summarized and a preliminary test of their dynamic performance is carried out. Moreover, this dissertation investigates the impact of GPS …

All-Sic Three-Phase Converters For High Efficiency Applications, Fan Xu

Doctoral Dissertations

The dissertation aims to improve the efficiency of three-phase converters using SiC power devices.The methodology to design a high efficiency all-SiC three-phase converter is presented. Four aspects are included: SiC power device evaluation, power loop parasitics analysis, high efficiency current source rectifier, and paralleled current source rectifier system.

The SiC JFET and MOSFET are tested based on voltage source and current source structures respectively. The dissertation proposes a device switching test circuit based on current source topology to simulate current commutation processes. The circuit can evaluate the switching performance and calculate switching loss of a power device used in a …

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 …

Portable Nano-Hydro Power Generator For The Dc House Project, Andrew Aw, James Biggs

Electrical Engineering

This senior project report explains the construction and design of a small, portable water generator that converts kinetic energy flowing in small creeks to electrical energy as a renewable source of energy for the DC House. The DC House, in short, is a project to build a self-sustainable house for Third World countries that utilizes only DC electricity. The system consists of two converters and a charge controller for a 12V lead-acid battery. The first converter converts the hydro generator voltage output to 15 Volts for safe and proper charging of the lead-acid battery by the charge controller. The second …

Motor Protection Lab Experiment Using Sel-710, Ozro Corulli

Electrical Engineering

Advancements in microprocessor based relay technology for power protection applications provide quicker response times and new methods of mitigation. This project develops a lab experiment for Cal Poly class EE444 - Power Systems Laboratory based on the Schweitzer SEL-710 motor protection relay. Learning objectives for this lab include relay setup, programming, and protection schemes for the following conditions: undervoltage, loss of phase, fault, locked rotor, and thermal overload. Today, utility companies across the globe use SEL relays for primary system protection, putting engineers familiar with their operation in high demand.

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 …

Design, Fabrication And Characterization Of Plasmonic Fishnet Structures For The Enhancement Of Absorption In Thin Film Solar Cells, Sayan Seal

Graduate Theses and Dissertations

Incorporating plasmonic structures into the back spacer layer of thin film solar cells (TFSCs) is an efficient way to improve their performance. The fishnet structure; which is a tunable, plasmonic light scatterer is used to enhance light absorption. Unlike other plasmonic particles that have been previously suggested, the fishnet is an electrically connected wire mesh and does not result in electric field localization, hence it results in greater absorption in the intrinsic Si layer. Unlike other designs, the fishnet structure is placed in the back spacer layer of the TFSC, so it does not block any incident light. There is …

Modeling And Protection Of Phase Shifting Transformers, Umar Khan

Electronic Thesis and Dissertation Repository

This thesis is mainly focused on the development of (i) phase shifting transformers (PSTs) mathematical and simulation models that can be used for the short-circuit and protection studies, and (ii) new phase shifting transformers protection methods that provide more secure and sensitive solutions than the standard current differential protection.

The first part of this thesis describes and presents the modeling of the single-core standard-delta, and two-core symmetrical and asymmetrical PST for protection and short-circuit studies. The models already available for such types of PSTs have limitations and require detailed test report data from the manufacturers. However, winding test data at …

Aging And Stabilization Of Pyrolitic Bio-Oils And Model Compounds, A. G. Manjula Taranganie Siriwardhana

Electronic Thesis and Dissertation Repository

When compared to conventional liquid fuels, bio-oil has several undesired properties such as high viscosity, high acidity, high molecular weight, instability, and phase separation upon aging. Therefore, bio-oil needs further stabilization and upgrading before it can be used as a fuel in engines. Phase separation is considered as one of the major issues because it is detrimental to any fuel application and creates problems in storage, transportation and upgrading of bio-oils. This thesis investigates the phase separation of hardwood derived bio-oil under accelerated aging conditions. Different alcohols are used as stabilizing agents and the minimum required amount of alcohol for …

Piezoelectric Transformer And Hall-Effect Based Sensing And Disturbance Monitoring Methodology For High-Voltage Power Supply Lines, Sneha Arun Lele

Electronic Thesis and Dissertation Repository

Advancements in relaying algorithms have led to an accurate and robust protection system widely used in power distribution. However, in low power sections of relaying systems, standard voltage and current measurement techniques are still used. These techniques have disadvantages like higher cost, size, electromagnetic interference, resistive losses and measurement errors and hence provide a number of opportunities for improvement and integration. We present a novel microsystem methodology to sense low-power voltage and current signals and detect disturbances in high-voltage power distribution lines. The system employs dual sensor architecture that consists of a piezoelectric transformer in combination with Hall-effect sensor, used …

Rooftop Pv Impacts On Fossil Fuel Electricity Generation And Co2 Emissions In The Pacific Northwest, Daniel Albert Weiland

Dissertations and Theses

This thesis estimates the impacts of rooftop photovoltaic (PV) capacity on electricity generation and CO2 emissions in America's Pacific Northwest. The region's demand for electricity is increasing at the same time that it is attempting to reduce its greenhouse gas emissions. The electricity generated by rooftop PV capacity is expected to displace electricity from fossil fueled electricity generators and reduce CO2 emissions, but when and how much? And how can this region maximize and focus the impacts of additional rooftop PV capacity on CO2 emissions? To answer these questions, an hourly urban rooftop PV generation profile for 2009 was created …

Solar Energy Used On Board The Ship And Responding Administration Countermeasures, Xiaoping Zhu

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Identification Of Markov Processes Within A Wind Turbine Array Boundary Layer, Matthew Scott Melius

Dissertations and Theses

The Markovianity within a wind turbine array boundary layer is explored for data taken in a wind tunnel containing a model wind turbine array. A stochastic analysis of the data is carried out using Markov chain theory. The data were obtained via hot-wire anemometry thus providing point velocity statistics. The theory of Markovian processes is applied to obtain a statistical description of longitudinal velocity increments inside the turbine wake using conditional probability density functions. It is found that two and three point conditional probability density functions are similar for scale differences larger than the Taylor micro-scale. This result is quantified …

Optimal Distribution Reconfiguration And Demand Management Within Practical Operational Constraints, Benyamin Moradzadeh

Doctoral Dissertations

This dissertation focuses on specific aspects of the technical design and operation of a `smart' distribution system incorporating new technology in the design process. The main purpose of this dissertation is to propose new algorithms in order to achieve a more reliable and economic distribution system.

First, a general approach based on Mixed Integer Programming (MIP) is proposed to formulate the reconfiguration problem for a radial/weakly meshed distribution network or restoration following a fault. Two objectives considered in this study are to minimize the active power loss, and to minimize the number of switching operations with respect to operational constraints, …

Control Studies Of Dfig Based Wind Power Systems, Zhiqiang Jin

Doctoral Dissertations

Wind energy as an outstanding and competitive form of renewable energy, has been growing fast worldwide in recent years because of its importance to reduce the pollutant emission generated by conventional thermal power plants and the rising prices and the unstable supplies of fossil-fuel. However, in the development of wind energy, there are still many ongoing challenges.

An important challenge is the need of voltage control to maintain the terminal voltage of a wind plant to make it a PV bus like conventional generators with excitation control. In the literature with PI controllers used, the parameters of PI controllers need …

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, …

Short-Term Electrical Load Forecasting For An Institutional/Industrial Power System Using An Artificial Neural Network, Eric Lynn Taylor

Masters Theses

For optimal power system operation, electrical generation must follow electrical load demand. The generation, transmission, and distribution utilities require some means to forecast the electrical load so they can utilize their electrical infrastructure efficiently, securely, and economically. The short-term load forecast (STLF) represents the electric load forecast for a time interval of a few hours to a few days. This thesis will define STLF as a 24-hour-ahead load forecast whose results will provide an hourly electric load forecast in kilowatts (kW) for the future 24 hours (a 24-hour load profile).

This thesis will use the method of Artificial Neural Networks …

Electrical Design Considerations And Packaging Of Power Electronic Modules, Shijie Wang

Graduate Theses and Dissertations

A modern power electronic module can save significant energy usage in the power electronic systems by improving their switching efficiencies. One way to improve the efficiency of the power electronic module is to reduce its parasitic circuit elements. The purpose of this thesis is to investigate the mitigation of parasitic circuit elements in power electronic modules. General methods of mitigating parasitic inductances were analyzed by the Q3D Extractor and verified by the time-domain reflectometry (TDR) measurements. In most cases, the TDR measurement results closely matched those predicted by the Q3D Extractor. These methods were applied to design and analyze a …

System Design Considerations And The Feasibility Of Passively Compensated, Permanent Magnet, Iron-Core Compulsators To Power Small Railgun Platforms, Collin Taylor Macgregor

Master's Theses

This thesis provides insight into the different aspects of compulsator design for use with railgun systems. Specifically, the design space is explored for passively compensated, permanent magnet iron-core compulsators. Seven design parameters are varied within a compulsator model developed for the Cal Poly Compulsator (CPCPA). The Matlab code for this model is included within the appendix. Efforts were made to compare and validate this compulsator model to published data from existing systems. The compulsator model was found to match closely with discharge pulse length, but resulted in lower values for peak current and projectile velocity by 50% and 30% respectively …

Study Of Stability Analysis Of A Grid-Connected Doubly Fed Induction Generator (Dfig)-Based Small Wind Farm, Baishakhi Dhar

Electronic Thesis and Dissertation Repository

Wind is the most reliable, clean and fast-developing renewable energy source. The DFIG-based variable speed wind turbine system is now the most popular in wind power industry. With power being so in-demanding, a large wind farm needs to be developed to produce more power from a stable system. But before such a large wind farm is installed, better understanding is needed of the system’s intrinsic dynamic behavior, range of stability region and parametric effects on system stability. Hence, a small wind farm with two identical DFIG-based wind turbines connected to a grid network has been considered for this study.

A …

Solar Data Analysis, Mike C. T. Ray

Dissertations and Theses

The solar industry has grown considerably in the last few years. This larger scale has introduced more problems as well as possibilities. One of those possibilities is analyzing the data coming from the sites that are now being monitored, and using the information to answer a variety of questions.

We have four questions which are of prime importance identified in this thesis:

1. Can data from customers be trusted?

2. Can we use data from existing sites to determine which sites need the most improvement?

3. Can we implement a location-based algorithm to reduce the amount of false positives for …

Quantum Circuit Synthesis Using Group Decomposition And Hilbert Spaces, Michael S. Saraivanov

Dissertations and Theses

The exponential nature of Moore's law has inadvertently created huge data storage complexes that are scattered around the world. Data elements are continuously being searched, processed, erased, combined and transferred to other storage units without much regard to power consumption. The need for faster searches and power efficient data processing is becoming a fundamental requirement. Quantum computing may offer an elegant solution to speed and power through the utilization of the natural laws of quantum mechanics. Therefore, minimal cost quantum circuit implementation methodologies are greatly desired.

This thesis explores the decomposition of group functions and the Walsh spectrum for implementing …

Three-Phase Reduced Switch Topologies For Ac-Dc Front-End And Single-Stage Converters, Dunisha Wijeratne

Electronic Thesis and Dissertation Repository

Conventional three-phase ac-dc converters have two converter stages. They have a front-end converter that converts the input ac voltage into an intermediate dc bus voltage and a second, back-end converter that converts this dc bus voltage into the desired isolated dc output voltage. The front-end converter also performs power factor correction (PFC) and shapes the three-phase input currents so that they are nearly sinusoidal and in phase with the three-phase input voltages. This allows the ac power source to be used in the most efficient manner.

The front-end ac-dc converter is typically implemented with six switches while the back-end dc-dc …

Simulation Of Power Control Of A Wind Turbine Permanent Magnet Synchronous Generator System, Nantao Huang

Master's Theses (2009 -)

This thesis presents a control system for a 2MW direct-drive permanent magnet synchronous generator wind turbine system with the objectives to capture the optimal power from the wind and ensure a maximum efficiency for this system. Moreover, in order to eliminate the electrical speed sensor mounted on the rotor shaft of the PMSG to reduce the system hardware complexity and improve the reliability of the system, a sliding mode observer based PM rotor position and speed sensorless control algorithm is presented here.

The mathematical models for the wind turbine and the permanent magnet synchronous machine are first given in this …

Rapid Tool Heating, Jason Chi, Bobby Dodge

Mechanical Engineering

Quatro Composites creates various molded parts for an array of industries. They are seeking to improve their thermoplastic molding process by decreasing the amount of time to heat up the steel tool that molds the thermoplastics. Currently, it takes approximately 1 hour to heat up their 120 pound steel mold from room temperature to approximately 700°F. The goal of this project is to create an optimum heating method that will minimize that heating time to about 20 minutes or less. It is critical for the stakeholders (Quatro Composites) to have a faster heating time in order to increase their production …

Design Of An Energy Efficient Virtual End Node Client Using Openadr2.0a And Smap, Kevin Navero

BioResource and Agricultural Engineering

Demand Response (DR) describes the set of actions taken to impose a reduction in electrical loads to stabilize the power grid and decrease costs. It is used when power grid emergencies or extremely high demand and congestion, threaten the electricity supply-demand balance. Automated Demand Response (ADR) describes a web-based control system that triggers DR events automatically by signaling other pre-programmed control systems. This project intends to use the OpenADR2.0 specifications provided by the OpenADR Alliance to construct an open source Virtual End Node (VEN) client to retrieve DR signals. The Simple Measurement and Actuation Profile (sMAP) software is also used …

Energy Dashboard Tool For Cal Poly Dormitories, Katie Zombro

Electrical Engineering

This project defines the needs, uses, and future projects (as well as business cases and procurement) of a University Housing dashboard tool, utilized by the Red Brick Dormitories on the Cal Poly campus. This easily accessed tool provides simple information regarding energy trending data, allowing for all student residents no matter their academic discipline, to understand their energy trends and opportunities for reduction. With the Energy Dashboard in place, Cal Poly’s red brick dormitories experienced savings ranging from 10%-20% from the 2011-2012 school year baseline, by the end of the 2012-2013 academic year. With the help of the Dashboard, competitions …