Engineering Commons^™

Design Of A Conditioner For Smoothing Wind Turbine Output Power, Murali Bottu

Masters Theses

"As a result of wind speed intermittency, wind turbine output power can be highly variable. The large variability in output power can adversely impact local loads that are sensitive to pulsating power. To mitigate large swings in power, the wind turbine output power can be smoothed by using a small energy buffer. A power conditioner is proposed to smooth the wind power output by utilizing the energy of an ultracapacitor. The conditioner is based on a single phase voltage source inverter (VSI) connected between the grid interconnection point and the ultracapacitor. The shunt VSI injects or absorbs active power from …

Towards On-Line Voltage Stability Assessment Using Synchrophasors, Himanshu Subandhu Hirlekar

Masters Theses

"Voltage instability has become a growing concern in the operation of power systems in recent years. The reason is that power systems all over are being operated with reduced margins because of increased demand exacerbated by a general reluctance to invest in improvement of the electric grid infrastructure. Until recently it was difficult to predict voltage instability in the on-line environment. However, advances in technology has made possible the on-line monitoring and assessment of voltage stability. Synchrophasors is a relatively new technology in the field of power systems which allows system operators to monitor the system conditions at specific measurement …

Rapid Simulation Of The Statistical Variation Of Crosstalk In Cable Harness Bundles, Xiang Li

Masters Theses

"Accurate assessment of crosstalk problems in cable harnesses requires simulation methods that account for the statistical variation of harness parameters. Methods are proposed to determine the influence of the statistical variation in wire positions, the rate that wires change position (i.e. "twist"), harness height, harness density (i.e. how closely wires are packed) and circuit loads. Methods use a combination of simulation and probability theory. Simulations use the T-parameter method, a rapid simulation technique for harness bundles. Simulation time is further improved by using the mean and variance of crosstalk estimated for fixed harness parameter values to estimate the mean and …

Impact Of Channel Statistics And Correlation On Underwater Acoustic Communication Systems, Jesse Scott Cross

Masters Theses

"Several statistical properties of underwater acoustic channels gathered from experiment data are analyzed. The baseband channel impulse response (CIR) is estimated using a time domain least squares technique with a sliding window applied to the probing sequences. From the CIR estimation, the probability distribution functions (PDFs) of the magnitude, real part, imaginary part, and phase of the CIR are calculated. Gamma, Rayleigh, and compound k distributions are fitted to the magnitude PDF and the fitness of the distributions are calculated with a two-sample Kolmogorov-Smirnov test. Other statistics such as the autocorrelation function, coherence time, and scattering function are evaluated. The …

Simulink As A Tool For Modelling Communication Systems, Chaitri Avinash Aroskar

Masters Theses

"Simulink is a graphical tool provided by MathWorks to enable model-based design and simulation. This thesis consists of two papers which take advantage of Simulink features in order to model communication systems.

The first paper employs Simulink to create projects to supplement a purely lecture oriented course: Communication Systems I. The projects cover Linear systems, Analog modulation and Digital modulation concepts in a set of six projects. These projects have been designed based on Gagne's nine events of instruction to enhance their impact on students' learning process. The paper also outlines the advantages of this approach over the conventional programming …

Quantitative Oxygen Imaging With A Display Screen And A Color Camera, Sanghan Park

Masters Theses

"Optical oxygen sensing uses luminophores such as metal complex dyes that respond to oxygen when illuminated by their specific excitation wavelengths. Traditional optical instruments are mostly spectrometric instruments based on the measurements of emission, absorption or reflection. There is, however, a great need to develop simple, economical, photometric detection components toward quantitative and two-dimensional imaging instruments.

In this work, familiar optoelectronic devices were utilized to demonstrate a simple determination method of gaseous oxygen both quantitatively and qualitatively. A liquid crystal display (LCD) screen and a color charge-coupled device (CCD) camera were employed as a light source for fluorescence excitation and …

Model Based Diagnostics And Prognostics Of Practical Industrial Systems, Raja Sekhar Kraleti

Masters Theses

"In this thesis, the diagnosis and prognosis of single and simultaneous multiple incipient faults in practical industrial systems is demonstrated in two papers. For the purpose of fault detection and failure prediction, a model based strategy is adopted, which involves using an online adaptive estimator. The online estimator estimates the system dynamics. Residual is generated based on the physical system model and the estimated system dynamics. This residual is used to detect the fault. Once the fault is detected, a tunable nonlinear neural network online approximator in discrete-time (OLAD) along with a robust adaptive term is initiated. The OLAD utilizes …

Educational Robotics: Using The Lego Mindstorms Nxt Platform For Increasing High School Stem Education, Matthew Aaron Strautmann

Masters Theses

"The field of educational robotics (ER) seeks to use the building and programming of robots to engage and educate the next generation of college freshman entering science and engineering majors. To increase the rate of application to science and engineering degree programs as well as the rate of retention, students must be engaged in high school. They must acquire the knowledge and interest to pursue these career choices. This research explores the use of robotics to interest high school students in science, technology, engineering, and math (STEM) and to improve their knowledge of these subjects. The case study developed instructional …

Development Of A Graphical User Interface For The Study Of Parallel-Connected Solar Arrays, Nisha Nagarajan

Masters Theses

"For any solar array it is necessary to be able to harness the maximum possible power from it. A new technology is proposed to improve the efficiency of solar arrays and harness maximum potential power as well by connecting the solar panels in parallel. This thesis describes the development of a graphical user interface for the evaluation of this parallel-connected solar array technology and to compare different scenarios for solar arrays to predict the potential power output to decide the best configuration for an application. This is done via several computations and analysis of field data. The first paper describes …

Optimal Control Of A Helicopter Unmanned Aerial Vehicle (Uav), David John Nodland

Masters Theses

"This thesis addresses optimal control of a helicopter unmanned aerial vehicle (UAV). Helicopter UAVs may be widely used for both military and civilian operations. Because these helicopters are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This thesis presents an optimal controller design via both state and output feedback for trajectory tracking of a helicopter UAV using a neural network (NN). The state and output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers while the output feedback approach uses an observer in addition to these controllers. The online approximator-based dynamic controller learns the …

Design Of A Current Probe For Measuring Ball-Grid-Array Packaged Devices, Tianqi Li

Masters Theses

"A current probe to measure BGA ball currents via magnetic induction has been designed. The probe is manufactured on a 4 layer flex circuit and has been validated by full wave simulations and measurements. The feature size of the probe is very tiny that it almost pushes the limit of flex-circuit technology. Several critical manufacturing problems were happened, and they have been solved now. The probe allows measuring currents of a 1 mm pitch BGA ball directly. Its operating frequency stretched from tens of MHz up to 3GHz. The BGA probe's mutual inductance is approximately 11 pH, and with amplifiers …

Microcontroller-Based Multiple-Input Multiple-Output Transmitter Systems, Balaji Madapuci Kanday

Masters Theses

"Multiple-Input Multiple_output (MIMO) Systems use multiple antennas at both the transmitter and receiver to increase data throughput and/or system reliability. An MIMO transmitter can be implemented using a variety of approaches. This work describes some of the approaches that can be used to generate the transmitted waveforms, and discuss the features and limitation of each. In particular, it shows haw a microcontroller-based system can be used for applications which require low power consumption. This thesis also describes the high-level design of a microcontroller-based MIMO transmitter. The computational speed of the microcontroller, as compared to Field-programmable Gate Array (FPGA) and Digital …

A Rapid-Acquisition Electrical Time-Domain Reflectometer For Analysis Of Time-Variant Impedance Discontinuities, Joseph Andrew Bishop

Masters Theses

"A distributed crack sensor has been developed for the measurement of cracks in concrete structures. The sensor is measured using a distributed measurement technique known as electrical time-domain reflectometry (ETDR). ETDR has traditionally been used to measure time-invariant (i.e. unchanging with time) impedance discontinuities, however applications of the sensor in structural failure analysis require measurement of time-variant (i.e. changing with time) impedance discontinuities at rates as high as 10 k measurements per second. ETDR is a suitable measurement technique for these applications since a time-domain reflectometer (TDR) acquisition can be performed in less than 100 µs. Employment of ETDR in …

Intelligent Control Of Smartparks And Wind Farms In Smart Grids, Priyam Chakravarty

Masters Theses

"With development in wind turbine technology, wind energy has become an important contestant in the utility market. However, wind energy has the intrinsic property of variations which causes fluctuations in the power grid.

Plug-in electric vehicles are drawing the attention of researchers and the electric power industry because of its need for charging from the grid and its ability to store energy. With increase in the numbers of plug-in electric vehicles, there will be significant penetration of distributed energy resources and hence plug-in electric vehicles connected to the grid in parking lots (SmartParks) can be used as energy storage sink …

Comparison Of Matrix Pencil And Prony Analysis For Estimating Electromechanical Modes In Noisy Signals For Power System Applications, Lisa L. Grant

Masters Theses

"As modern power systems continue to grow and evolve, accurate system stability analysis and oscillation control become increasingly important to guarantee system security. Network instability due to power system oscillations caused by the natural modes of the system is becoming a common occurrence. Modal analysis techniques can estimate the eigenvalues of large nonlinear systems from their dynamics responses. The extracted modal information can be applied to detect low frequency oscillations and assess stability margins for power system monitoring and preventive control. Modal information is also useful for low-frequency oscillation damping controller design. This thesis examines two techniques for modal identification …

Multiple-Input Multiple-Output System Simulation For Spinning Vehicles, Samuel James Petersen

Masters Theses

"This paper investigates the performance of a multiple-input multiple-output (MIMO) wireless communication system, when the transmitter is located on a spinning vehicle. In particular, a 2x2 MIMO system is used, with Alamouti coding at the transmitter. Both Rayleigh and Rician statistical models are considered in this paper and are combined with a deterministic spinning model to simulate the channel. The spinning of the transmitting vehicle, relative to the stationary receive antennas causes additional signal fading, and complicates the decoding and channel estimation. The simulated bit error rate is the primary performance metric used. A 4x2 asymmetric Alamouti coding scheme is …

Mutual Attraction Guided Search: A Novel Solution Method To The Traveling Salesman Problem With Vehicle Dynamics, Jared Adam Nisbett

Masters Theses

"Traveling Salesman Problem (TSP) solution techniques are often used for route planning for automated vehicles. Most TSP solution methods focus on path length as the fitness reference, however in many cases, traversal time is of more practical importance. Mutual Attraction Guided Search (MAGS) is a novel solution method that uses an iterative process to simultaneously optimize both angle of travel through each target as well as the ordering of the targets in order to optimize path traversal time. MAGS deterministically locates a locally optimum solution quickly and can optimize for the acceleration limits of a specific vehicle rather than requiring …

Grid Frequency And Voltage Support Using Photovoltaic Systems With Energy Storage Assist, Ravi Bhatt

Masters Theses

"An optimized operating scheme for a grid-connected community based photovoltaic (PV) system is described. The system can participate in grid ancillary services like frequency and voltage regulation functions based on the Smart Grid framework. The proposed model comprises of a PV plant with Li-ion batteries coupled to the grid by means of a three-phase inverter. A two-way communication between the PV plant and the grid is assumed. The PV/storage plant provides constant updates on its current kW/kVar capability and the grid transmits the demand for specific amounts of power and for specific lengths of time. The battery charging energy can …

Electron Transport Through Two Irreducibly-Coupled Aharonov-Bohm Rings With Applications To Nanostructure Quantum Computing Circuits, Casey Andrew Cain

Masters Theses

"A thorough investigation was conducted into the six fundamental classes of two coupled Aharonov-Bohm rings that share a finite center common path, when the phase of the electron wave function was modulated by two distinct magnetic fluxes. The coupling is similar to two coupled atoms. The behavior of charge accumulation along the center common path or equivalently the bonding and anti-bonding of the two rings can be achieved as the two applied fluxes are varied. Thus when three external terminals are connected to such coupled rings, the behavior of the electron transport is divided into several classes depending on the …

Field Programmable Gate Array Based Multiple Input Multiple Output Transmitter, Richa Shekhar

Masters Theses

"MIMO is an advanced antenna technology compared to Single Input Single output (SISO), Multiple Input Single Output (MISO), and Single Input Multiple Output (SIMO) and is used to obtain high data rate in the system. Multiple-Input Multiple-Output (MIMO) systems have at least two transmitting antennas, each generating unique signals. However some applications may require three, four, or more transmitting devices to achieve the desired system performance. This thesis describes a comparison between different approaches like the microcontroller, ASICs and the FPGA available in the market for baseband signal generation. It also describes the design of a scalable MIMO transmitter, based …

Characterization Of Shielding Effectiveness For Metallic Enclosures, Nicholas Bennett Mentesana

Masters Theses

"This topic discusses and verifies an equation for estimating the shielding effectiveness of metallic enclosures through the use of numerical simulations. Using ideas from Bethe's "Theory of Diffraction by Small Holes", a previous student from the Missouri S&T Electromagnetic Compatibility Laboratory developed an equation that would yield an envelope prediction for the worst-case EMI from an aperture array backed by an over-moded cavity. Min Li (PhDEE '99) used results from measurements, simulations, and physics-based equations to formulate a simple equation that would predict these EMI levels. The main purpose of this thesis is to revisit this work and determine when …

Simultaneous Measurement Of Temperature And Strain By Three-Section Phase-Shift Long Period Fiber Grating, Hongbiao Duan

Masters Theses

"Long period fiber gratings (LPFGs) have found many applications as sensors to measure strain, temperature, refractive index and other physical parameters. In various sensing applications, the cross-sensitivity between two parameters, especially the temperature cross-sensitivity, has been a major difficulty to achieve high accuracy measurement. One of the solutions is to develop LPFG sensors for simultaneous, multi-parameter measurements.

In this thesis, three-section phase-shift (PS) LPFGs were fabricated and investigated for simultaneous measurement of temperature and strain. Compared with a two-section PS-LPFG, a three-section PS-LPFG has two deeper resonance sub bands and a larger separation between the two bands. The strain, temperature …