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Short-Circuit Protection For Low-Voltage Dc Distribution Systems Based On Solid-State Circuit Breakers, Sharthak Munasib

Graduate Theses and Dissertations

Proper short-circuit protection in dc distribution systems has provided an austere challenge to researchers as the development of commercially-viable equipment providing fast operation, coordination and reliability still continues. The objective of this thesis is to analyze issues associated with short-circuit protection of low-voltage dc (LVDC) distribution systems and propose a short-circuit protection methodology based on solid-state circuit breakers (SSCBs) that provides fault-current limiting (FCL). Simulation results for a simplified notional 1-kVdc distribution system, performed in MATLAB/SIMULINKTM, would be presented to illustrate that SSCB solutions based on reverse-blocking integrated gate-commutated thyristors (RB-IGCT) are feasible for low-voltage dc distribution systems but requires …

Linear Quadratic Optimal Control For A Cascaded Converters-Based Microgrid, Amlam Niragire

Graduate Theses and Dissertations

There is a constant transformation of the electric grid due to an ongoing interest in the deployment of renewable energy resources and electric microgrid formation. This transformation, though advantageous in many ways, poses great challenges for the energy industry and there must be a constant improvement in modeling, simulation, analysis and control techniques in order to characterize and optimize the system design and operation. In this light, the scope of this thesis is focused on developing a linear model, analyzing the stability and designing an optimal linear quadratic regulator (LQR) for a microgrid system. The microgrid system used is inspired …

Applications Of Krylov Subspace And Balanced Truncation Model Order Reduction In Power Systems, Sebastian Emanuel Garrido

Graduate Theses and Dissertations

Dynamic representations of power systems usually result in the order of hundreds or even thousands of buses. Therefore, reduction of these dynamic representations is convenient. Two applications of model order reduction in power systems are discussed in this thesis. First, Krylov subspace-based method is applied to the IEEE-123 Node Test Feeder in the context of distribution-level power systems simulation. Second, a Balanced Truncation-based model reduction is implemented in the 3-Machine 9-Bus system for designing a power system controller in the context of generation- and transmission-level power systems.

First, for the IEEE-123 Node Test Feeder, a two-sided Arnoldi algorithm is proposed …

Silicon Germanium Bicmos Comparator Designed For Use In An Extreme Environment Analog To Digital Converter, Benjamin Riley Sissons

Graduate Theses and Dissertations

This thesis demonstrates the process of creating a radiation hardened and extreme temperature operating comparator from start to finish in the 90 nm SiGe 9HP process node. This includes the entire design flow from examining comparator topologies, to designing the initial comparator circuits, to simulating the comparator over a temperature range of -196°C to 125°C, and finally the testing of the fabricated circuit. To verify the circuit would work at low temperatures, several new device models were created that could be used for simulations at -196°C. In addition to its properties as a standalone comparator, the circuit was also used …

Characterization Of Coupled Gold Nanoparticles In A Sparsely Populated Square Lattice, Roy Truett French Iii

Graduate Theses and Dissertations

Metal nanoparticles deposited in regular arrays spaced at optical wavelengths support a resonance due to a coherent coupling between localized surface plasmon mode and lattice diffraction allowing for engineering of tunable devices for use in biological sensors, nanoantennae, and enhanced spectroscopy. Techniques such as electron beam lithography, focused ion beam lithography, nanosphere lithography, and nanoimprint lithography are used for fabrication but are limited by cost, device throughput, and small deposition. Polymer soft lithography and continuous dewetting of particles is a potentially viable alternative showing promise in all of those areas. This thesis developed the fabrication of a refined hydrophilic nanoimprinted …

Modeling And Validation Of 4h-Sic Low Voltage Mosfets For Integrated Circuit Design, Shamim Ahmed

Graduate Theses and Dissertations

Silicon Carbide is a promising wide bandgap material and gradually becoming the first choice of semiconductor for high density and high efficiency power electronics in medium voltage range (500-1500V). SiC has also excellent thermal conductivity and the devices fabricated with the material can operate at high temperature (~ 400 ⁰C). Thus, a power electronic system built with SiC devices requires less cooling requirement and saves board space and cost. The high temperature applications of SiC material can also be extended to space exploration, oil and gas rigging, aerospace and geothermal energy systems for data acquisition, sensing and instrumentation and power …

Development Of An Oxygen Saturation Monitoring System By Embedded Electronics, Manikandan Venkatesan Gomathy

Graduate Theses and Dissertations

Measuring Oxygenation of blood (SaO2) plays a vital role in patient’s health monitoring. This is often measured by pulse oximeter, which is standard measure during anesthesia, asthma, operative and post-operative recoveries. Despite all, monitoring Oxygen level is necessary for infants with respiratory problems, old people, and pregnant women and in other critical situations.

This paper discusses the process of calculating the level of oxygen in blood and heart-rate detection using a non-invasive photo plethysmography also called as pulsoximeter using the MSP430FG437 microcontroller (MCU). The probe uses infrared lights to measure and should be in physical contact with any peripheral points …

Investigation Of Fes2 Nanoparticles For Use In Optoelectronic And Thermoelectric Applications, Rick Tefal Eyi Nkoghe

Graduate Theses and Dissertations

Iron pyrite (FeS2) is the most abundant sulfide material on earth. This material has been widely investigated by researchers because of its optical properties. However, it has been difficult to produce High efficiency FeS2 based solar cells. This is due to many different impurities that arise when making the materials. The ability to synthesize pure pyrite FeS2 material is therefore critical for applications.

Pure Iron pyrite nanocrystals were synthesized using hot injection by mixing sulfur with an iron precursor in the presence of an amine. To improve the stability, shorter ligands replaced the native amines ligands. The stability of the …