Electrical and Electronics Commons^™

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 …

Dc-Dc 4-Switch Buck-Boost Converter For Energy Harvesting From Elliptical Machines, Alexander C. Samietz, Gustavo Guzman

Electrical Engineering

The senior project report documents the process of replacing the network of resistors inside an elliptical machine with a DC-DC buck-boost converter. The buck-boost DC-DC converter accepts a wide input range of 5-60 Volts, with an output of 36 Volts for the most efficient use of the already available microinverter. The microinverter reclaims the lost energy and safely distributes it back to the electrical grid. The addition of this project reduces heat emissions from wasted energy and shrinks the carbon footprint of its users.

Spectrum Sharing, Latency, And Security In 5g Networks With Application To Iot And Smart Grid, Imtiaz Parvez

FIU Electronic Theses and Dissertations

The surge of mobile devices, such as smartphones, and tables, demands additional capacity. On the other hand, Internet-of-Things (IoT) and smart grid, which connects numerous sensors, devices, and machines require ubiquitous connectivity and data security. Additionally, some use cases, such as automated manufacturing process, automated transportation, and smart grid, require latency as low as 1 ms, and reliability as high as 99.99\%. To enhance throughput and support massive connectivity, sharing of the unlicensed spectrum (3.5 GHz, 5GHz, and mmWave) is a potential solution. On the other hand, to address the latency, drastic changes in the network architecture is required. The …

Effect Of Wireless Communication Delay On Dc Microgrids Performance, Mahmoud Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

This paper investigates the effect of wireless communication technologies latency on the converters and the bus voltage of centrally communication based controlled DC microgrids (MGs) during islanding. A DC microgrid with its communication based control scheme was modeled to show the impact of latency. Simulation results show that the impact may be severe depending on the design, and the operational condition of the microgrid before latency occurs.

Impact Of Communication Latency On The Bus Voltage Of Centrally Controlled Dc Microgrid During Islanding, Mahmoud Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

Maintaining a sustainable and reliable source of energy to supply critical loads within a renewable energy based microgrid (MG) during blackouts is directly related to its bus voltage variations. For example, voltage variation might trigger protection devices and disconnect DERs within the MG. Centrally controlled MGs (CCMGs) type is dependent on communication. Therefore, it is very important to analyze the impact of communication networks performance degradation, such as latency, on the bus voltage of CCMGs. This paper investigates the effect of wireless communication technologies latency on the bus voltage and performance of centralized DC MGs. Two mathematical models were developed …

Improving A Transient Stability Control Scheme With Wide-Area Synchrophasors And The Microwecc, A Reduced-Order Model Of The Western Interconnect, Robin Hallett

Graduate Theses & Non-Theses

This thesis is composed of two research projects. The first project investigated the feasibility of improving a generator tripping control scheme using wide-area synchrophasors and the second project focused on building a reduced-order model of the western North American power system (wNAPS) for use in a real-time digital simulator.

Transient stability is a major reliability issue for power systems. Radially-connected power plants are especially prone to transient stability problems. An example of this is the fourgenerator Colstrip power plant located in southeast Montana, USA. The Colstrip generators are protected by a tripping control system called the Acceleration Trend Relay (ATR) …

Hybrid Perovskite Characterization And Device Applications., Kasun Fernando

Electronic Theses and Dissertations

Hybrid perovskites are a group of materials that has shown a great impact in the field of scientific research in the past decade due to the efficiency gain within a short period of time. Hot casting is one technique that has been producing high efficient and stable solar cells. Electrical transportation of lateral device structure by such film is explored to understand basic properties and predict possible device applications using it. Under dark, memristive ability of the film was explored using various experiments. Unique uni-polar memristor ability was observed. Using the experimental results, a model is hypothesized using the concepts …

Transformerless High-Power Medium-Voltage Multi-Module Pv Converters, Hasan Bayat

Electronic Thesis and Dissertation Repository

This thesis is focused on the modular multilevel converter (MMC) for Photovoltaic (PV) applications. It is an attempt to address the issues associated with the modeling, control, and power mismatch elimination of the MMC-based PV systems. Firstly, a new real power reference generation scheme is proposed that creates a linear relationship between the real power reference of the system and the dc link voltage of the submodules. Further, a new power mismatch elimination strategy is proposed for the MMC-based PV system which ensures balanced currents are delivered to the host grid regardless of leg and arm power mismatches. The thesis …

Investigation Of The Skin Effect In Alternating Currents, Matthew Liang

The International Student Science Fair 2018

My research is on the investigation of the skin effect in alternating currents. The skin effect is when an alternating current tends to flow on the surface of the conductor, such that the current density is highest near the surface, and decreases with greater depths in the conductor. This is due to the alternating current inducing changing magnetic fields, which in turn induces currents that oppose the original flow of current, resisting the current flowing through the centre the most. This reduces the effective cross-sectional area of the conductor and increases the resistance, causing increased power losses. This effect becomes …

Investigation Of The Skin Effect In Alternating Currents, Matthew Liang

The International Student Science Fair 2018

My research is on the investigation of the skin effect in alternating currents. My project is broken down into 4 sub-aims. The first aim would be, to be able to mathematically model the distribution of current in the radius of the wire, which consists of the applications of the Maxwell equation and solving zeroth order differential Bessel equations of the first kind. The next aim would be to computationally plot out the desired current readings as the depth of the wire increases from the surface, using the Matlab software. The third aim that I have would be conducting an experiment, …

Energy Conversion System For Travelers (Ecost), Thipok Bovornratanaraks

The International Student Science Fair 2018

We have innovated “The Energy Conversion System for Travelers” or the ECoST. With the fact that most travelers have wheeled cabin-bags, whilst walking, the wheels will rotate so why don’t we harvest electricity from this kinetic energy? We thus install our innovation, the ECoST, to the bag to generate electricity from the spinning wheels. The electricity is then kept in the storage unit and ready to charge your empty battery devices in an emergency case via a USB port. To make life easy, our ECoST was designed to replicate the power bank charging method; therefore, we can charge …

Analog Sorting Using Pulse Width Modulation, Riley C. Olson

Computer Engineering

As time goes on, computers become more and more powerful. However, as processing time becomes less of a limiting factor for computing tasks, power consumption takes its place for many tasks. This paper proposes and tests a new method for sorting analog signals. This new sorting method converts analog signals into Pulse Width Modulated(PWM) signals of varying duty cycle , which are then sorted by a simple network of combinational logic, and then converted to a normal binary representation. In order to implement this new method, multiple circuits had to be designed and and tested to ensure their functionality and …

Electric Upgrades - Supercapacitor Electric Bicycle, John Chen, Wilson Fletcher, Spencer Esparza

Electrical Engineering

Supercapacitors provide high current capabilities compared to conventional lithium-ion batteries, allowing for fast charging and discharging of electrical energy. This project seeks to test the benefits of supercapacitors in an electric bicycle unit in order to gain higher regenerative energy. The main components of the bicycle are its regenerative motor, supercapacitor array, and motor controller. Developing the project will provide data on the feasibility of using alternative battery storage and charging.

The Modified-Multiphase Boost Converter: Combined Inductors And Capacitors Topology, Zachary L. Eldredge

Master's Theses

In this work, a modified boost converter design has been implemented in a multiphase configuration with a condensed topology. The modified aspect of the design has already been proven to drastically reduce input current ripple by about 40% in a single-phase implementation. By placing two modified boost converters in parallel with interleaving main switches (multiphase), the input inductors and modified capacitors of the modified topology can be reduced to just one of each, lowering the number of components, size, and cost. Additionally, multiphase DC/DC converters lower input/output voltage and current ripples while delivering more power compared to single-phase converters. By …

A Multiphase Modified Boost Converter With Reduced Input Current Ripple: Combined Capacitors, Omri Nissan

Master's Theses

The delivery of high power and smaller footprints through a non-isolated topology demands for the use of multiphase topology in DC-DC converters. Multiphase reduces the ripple observed on both the input and output waveforms; however, it may not be enough to connect to sensitive power sources such as renewable energy sources. A single-phase modified boost converter demonstrates the ability to acquire very minimal input current ripple by addition of passive components. The expansion to multiphase topology is the next logical step for higher power application while furthering the low input current ripple benefit. In this thesis, the multiphase modified boost …

Performance Evaluation Of Energy-Autonomous Sensors Using Power-Harvesting Beacons For Environmental Monitoring In Internet Of Things (Iot), George Dan Moiş, Teodora Sanislav, Silviu Corneliu Folea, Sherali Zeadally

Information Science Faculty Publications

Environmental conditions and air quality monitoring have become crucial today due to the undeniable changes of the climate and accelerated urbanization. To efficiently monitor environmental parameters such as temperature, humidity, and the levels of pollutants, such as fine particulate matter (PM2.5) and volatile organic compounds (VOCs) in the air, and to collect data covering vast geographical areas, the development of cheap energy-autonomous sensors for large scale deployment and fine-grained data acquisition is required. Rapid advances in electronics and communication technologies along with the emergence of paradigms such as Cyber-Physical Systems (CPSs) and the Internet of Things (IoT) have led to …

Applications Of Artificial Intelligence In Power Systems, Samin Rastgoufard

University of New Orleans Theses and Dissertations

Artificial intelligence tools, which are fast, robust and adaptive can overcome the drawbacks of traditional solutions for several power systems problems. In this work, applications of AI techniques have been studied for solving two important problems in power systems.

The first problem is static security evaluation (SSE). The objective of SSE is to identify the contingencies in planning and operations of power systems. Numerical conventional solutions are time-consuming, computationally expensive, and are not suitable for online applications. SSE may be considered as a binary-classification, multi-classification or regression problem. In this work, multi-support vector machine is combined with several evolutionary computation …

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 …

Stochastic Modeling Of Wireless Energy Transfer With Applications In Wireless Displacement Sensing Of Structures, Shaun G. Veilleux

Electronic Theses and Dissertations

Wireless communications are being utilized in nearly every field of work and impact virtually everyone's daily life. With the increased use of wireless sensors, the difficulty of powering them becomes more apparent. One emerging technology is the use of wireless energy transfer which utilizes either a designated transmitter or harvests otherwise wasted energy. Since the amount of transferable wireless energy is limited modeling and simulating a system's probability of operation is desired in order to maximize the run time of the sensor. These simulations allow for the investigation into the impact of a smart scheduling algorithm that can determine the …

A Human Powered Micro-Generator For Charging Electronic Devices, John Adam

Senior Theses

A hand-pulled generator has been designed and tested. A preliminary result has been obtained and discussed. This device was created to provide outlet-free charging. Electronic devices are useful when going out into the wilderness. A portable power supply is necessary to keep an electronic device alive. This project created a device that converts human energy into electricity to charge electronic devices. This thesis overviews the device’s design, build, and tests. Two different tests were run to determine that the device is capable of charging the storage battery. The device presented can provide 14 minutes of charging time with one hour …

Grid-Connected Photovoltaic Systems Based On Nonlinear Control., Pablo R. Rivera

Electronic Theses and Dissertations

Nowadays, due to the high-scale penetration of photovoltaic systems, reliable and efficient grid-connected photovoltaic (PV) systems utilizing the advances of power electronics and control system technology are desirable. Thus, single-stage grid-connected photovoltaic systems, have gained attention, especially in low voltage applications. However, PV systems exhibit nonlinear behavior that could negatively affect the performance of the system if they are not adequately compensated for. In this dissertation, using the general structure for the synchronous dq0 frame, a single-stage three-phase grid-connected photovoltaic system, and a single-stage single-phase grid-connected PV system, both with a nonlinear control strategy, are developed to track the maximum …

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 …

On-Line Condition Monitoring, Fault Detection And Diagnosis In Electrical Machines And Power Electronic Converters, Alberto Berzoy

FIU Electronic Theses and Dissertations

The objective of this PhD research is to develop robust, and non-intrusive condition monitoring methods for induction motors fed by closed-loop inverters. The flexible energy forms synthesized by these connected power electronic converters greatly enhance the performance and expand the operating region of induction motors. They also significantly alter the fault behavior of these electric machines and complicate the fault detection and protection. The current state of the art in condition monitoring of power-converter-fed electric machines is underdeveloped as compared to the maturing condition monitoring techniques for grid-connected electric machines.

This dissertation first investigates the stator turn-to-turn fault modelling for …

Novel Strongly Coupled Magnetic Resonant Systems, Daerhan Liu

FIU Electronic Theses and Dissertations

Wireless power transfer (WPT) technologies have become important for our everyday life. The most commonly used near-field WPT method is inductive coupling, which suffers from low efficiency and small range. The Strongly Coupled Magnetic Resonance (SCMR) method was developed recently, and it can be used to wirelessly transfer power with higher efficiency over a longer distance than the inductive coupling method.

This dissertation develops new SCMR systems that have better performance compared to standard SCMR systems. Specifically, two new 3-D SCMR systems are designed to improve the angular misalignment sensitivity of WPT systems. Their power transfer efficiency for different angular …

Accurate Location Of Evolving Faults On Transmission Lines Using Sparse Wide Area Measurements, Xiangqing Jiao, Yuan Liao

Electrical and Computer Engineering Faculty Publications

In electric power systems, not all fault conditions remain unchanged during faults. An evolving fault has one characteristic initially and changes to a different condition subsequently. Locating evolving faults is challenging due to the change in fault type shortly after the fault initiation. This paper presents a new approach for estimating the locations of evolving faults on transmission lines. By using sparse wide area voltage measurements, this method is able to accurately locate evolving faults without requiring measurements from either end of the faulted line. There is no need to detect whether a fault is an evolving fault or not. …

Contributions To Hybrid Power Systems Incorporating Renewables For Desalination Systems, Nasser Alawhali

Theses and Dissertations--Electrical and Computer Engineering

Renewable energy is one of the most reliable resource that can be used to generate the electricity. It is expected to be the most highly used resource for electricity generation in many countries in the world in the next few decades. Renewable energy resources can be used in several purposes. It can be used for electricity generation, water desalination and mining. Using renewable resources to desalinate the water has several advantages such as reduce the emission, save money and improve the public health. The research described in the thesis focuses on the analysis of using the renewable resources such as …

A Quantification Analysis On Potential Use Of Recuperated Regenerative Braking Energy From Nyct Subways Into Charging Electric Buses, Ahmed S. Rahman

Dissertations and Theses

The New York Metropolitan Transportation Authority (MTA) is one of the biggest consumers of electricity in east coast of the United States. According to a report published by Dayton T. Brown in 2013, MTA consumes approximately 2150 GWh electrical energy per year for traction power, where the New York City Transit (NYCT) alone is a consumer of about 80% of the total annual MTA energy consumption. This continuous high demand for electricity from a single organization opens research opportunities to search for alternative ways to reduce the needs. NYCT Subways has an existing total rolling stock of 6,418 train cars …

Optimal Operation Of Integrated Microgrids, Abdullah Albaker

Electronic Theses and Dissertations

Microgrids' deployments are increasing and projected to increase even more in future due to the significant advantages that are provided by this technology for end-use customers. However, microgrids can be connected to each other to create integrated microgrids system, which can further promote the anticipated and desired benefits. An integrated operation of microgrids can potentially improve the local power system reliability and resilience, increase the individual microgrids' economic benefits, and promote further utilization of renewable energy resources. Integrating microgrids, to achieve a microgrid network or cluster, is expected be an essential application towards smarter power grids and a key operational …

Electrowetting Using A Microfluidic Kelvin Water Dropper, Elias Yazdanshenas, Qiang Tang, Xiaoyu Zhang

Mechanical & Aerospace Engineering Faculty Publications

The Kelvin water dropper is an electrostatic generator that can generate high voltage electricity through water dripping. A conventional Kelvin water dropper converts the gravitational potential energy of water into electricity. Due to its low current output, Kelvin water droppers can only be used in limited cases that demand high voltage. In the present study, microfluidic Kelvin water droppers (MKWDs) were built in house to demonstrate a low-cost but accurately controlled miniature device for high voltage generation. The performance of the MKWDs was characterized using different channel diameters and flow rates. The best performed MKWD was then used to conduct …