Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"Z-source"”.
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Z-source circuit breakers in naval power systems
… systems on future vessels. Integrating the z-source circuit breaker into a "typical" naval MVDC power system requires understanding system dynamics that may cause the circuit breaker to inadvertently energize a circuit through regenerative turn-on of the thyristor. An electrically-scaled model …
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Development of P-resonant controller for Z-source three phase inverter
… control the output current and voltage for a Z-Source three phase inverter. The model scheme is developed and simulated in MATLAB/Simulink software environment. The Z-Source inverter is special type of inverter that provide the voltage boost capability in which it results with an output voltage …
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A 3-phase Z-source inverter driven by a novel hybrid switching algorithm
A 3-phase Z-source inverter has been researched, designed, simulated, builtand tested. The purpose of the inverter is to deliver 3-phase 400 VAC from aDC supply that can vary over a range of 20 to 70 Vdc. This is done with a Zsourceinverter topology which is a single conversion method with no …
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Design and implementation of a single phase modified Z-source inverter topology for photovoltaic/grid interconnected DC charging applications
Solar energy has been the most popular sources of renewable energy for residential and semi-commercial applications. Solar energy sources alone cannot be used to charge an electric vehicle (EV). Solar/Grid interconnected charging stations are used to charge EV batteries to reduce the dependency on …
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Novel Voltage Control Methods for quasi-Z-source Network Converters with Focus on Fixed DC-Link Voltage, Constant- Frequency and Soft-Switching Operation
… power transfer among batteries, renewable sources, and the utility grid. quasi-Z-source (qZS) converters are especially attractive for their single-stage buck–boost capability, continuous input current, and inherent reliability. A central challenge, however, is the intermediate DClink …
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Parameter study of boost inverter topologies for high voltage gain
… that is beyond human control. The conventional Z-source network and switch inductor Z- source inverter is located between the DC voltage source and the inverter, which boosts the DC voltage. Traditional inverters such as voltage source inverters and current source inverters have few inherent …
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Boost Matrix Converters in Clean Energy Systems
… minimum number of semiconductor switches. The Z-source, Quasi Z-source, Series Z-source and Switched-inductor Z-source networks were originally proposed for boosting the output voltage of power electronic inverters. These ideas were extended here on three-phase to three-phase and three-phase to …
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The accretion process in neutron-star low-mass X-ray binaries
… relations between subtypes (mainly atoll and Z sources), and the origins of different X- ray states. Atoll sources are less luminous and have both hard and soft spectral states, while Z sources have three distinct branches (horizontal(HB)/normal(NB)/flaring(FB)) whose spectra are mostly soft. I …
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Using gravitational lens geometry to measure cosmological parameters
… and w) using gravitational lens geometry, source and lens redshifts, and the velocity dispersion of the lensing galaxy. This technique makes use of the relation [theta][sub]E = 4[pi]... where the critical radius [theta][sub]E and the one-dimensional velocity dispersion of the lensing galaxy …
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Advanced topologies of high step-up DC-DC converters for renewable energy applications
… to connect low-voltage renewable energy (RE) sources, such as photovoltaic (PV) panels and fuel cells (FCs), into a high-voltage DC bus in renewable energy applications. The proposed converters are based on the combinations of various voltage-boosting (VB) techniques, including interleaved and …
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Development of a multilevel converter topology for transformer-less connection of renewable energy systems
… research theme in the last decade. Clean energy sources (such as wind energy and solar energy) have considerable potential to reduce reliance on fossil fuels and mitigate climate change. However, wind energy is going to become more mainstream due to technological advancement and geographical …
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Power processing and active protection for photovoltaic energy extraction
… can draw upon the planet's most abundant power source - the sun. However, relatively high levelized cost of energy (LCOE), the ratio of the total cost of ownership to the total energy extracted over the lifetime of the generation system, has limited the grid penetration of solar power. Mismatch …
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X-ray spectroscopy of neutron star low-mass X-ray binaries
… to further our understanding of these sources. First, I give an overview of important X- ray astrophysics relevant to the work I present in subsequent chapters, as well as information about the X-ray observatories from which I obtained my data. In the next three chapters, I consider …
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Mass transfer and accretion in the eccentric neutron-star binary Circinus X-1
… after phase zero of each 16.55-day cycle of the source. This behavior is thought to be due to enhanced mass transfer occurring near periastron of a highly eccentric binary orbit. Dips below the baseline intensity level also occur near phase zero. I modeled the evolution of the energy spectrum …
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Spectral analysis of X-ray binaries
… X-ray binaries (NS-LMXBs), with a particular source, XTE J1701-462, playing a central role. First, I construct and study color-color and hardness-intensity diagrams (CDs and HIDs) for a large sample of NS-LMXBs using Rossi X-ray Timing Explorer (RXTE) data spanning ~15 years. I study in …
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Offshore hybrid power plants with wind energy, photovoltaic and energy storage
… systems that combine several renewable energy sources are flowering, mainly in grid-connected configurations. The presence of this distributed generation in the electric grid changes its control and operation significantly. Therefore, special attention should be paid to the study of hybrid …
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New and improved solutions for the configuration, management and operation of large-scale photovoltaic power plants using hybrid energy storage system
… power generation compared to conventional energy sources, such as intermittency, non-dispatchability, and unreliability. From those drawbacks, the aim is to find creative solutions to mitigate these issues with a power plant combining PV and hybrid energy storage systems (HESS). In doing so, …
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Inversores Fonte Z monofásicos e conversor de dois estágios para sistemas fotovoltaicos sem Transformador
Este trabalho apresenta um estudo comparativo de conversores monofásicos aplicados a sistemas fotovoltaicos sem transformador. Topologias de inversores sem transformador têm menores custos, tamanho e peso. Contudo, a não utilização do transformador pode ser responsável por consideráveis valores de …