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 20 of 21 for “"High-frequency Transformer"”.
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Thermal-magnetic finite element model of a high frequency transformer
In high-frequency power transformers, magnetic material properties cannot be assumed to be constant. These properties vary with frequency, temperature, and magnetic flux density. Heat generation is, in turn, a function of the magnetic permeability, magnetic flux density, and frequency. Current …
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High-Frequency Transformer Design for Solid-State Transformers in Electric Power Distribution Systems
<p>The objective of this thesis is to present a high- or medium-frequency transformer design methodology for Solid-State Transformer (SST) applications. SSTs have been proposed as a replacement of the traditional 50/60 Hz transformer in applications demanding high-power density. Moreover, due to …
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High efficiency DC/AC power converter for photovoltaic applications
… for conversion from low-voltage (25-40V) DC to high voltage AC (e.g. 240VAC,RMS). The circuit topology is based on a full-bridge series resonant inverter, a high-frequency transformer, and a novel half-wave cyclo-converter. The operational characteristics are analyzed, and a multidimensional …
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Modeling, analysis, and design of a 10 kVA, 20 kHz transformer
The design of a high-frequency transformer at levels above 1 kVA is limited by the winding and core materials which are available. This res~arch presents methods for the design and modeling of a 10 kVA transformer operating at a frequency of 20 kHz using readily available materials. A special …
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Investigation of a High-Frequency Link Single-Stage Asymmetrical Multilevel Converter for Grid Integration of Renewable Energy Systems
… the grid. Cascaded multilevel converters with a high- frequency link have emerged as a viable candidate for such applications. Electrical isolation can be provided using a compact high-frequency transformer connected in the link thus avoiding a bulky line frequency transformer. The use of …
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A single stage full bridge power factor corrected AC/DC converter
… to provide a regulated DC power supply at high input power factor. Elimination of one of these stages can reduce the cost, weight, size, complexity and increase the overall reliability of this converter. This thesis proposes a single stage power factor correction converter circuit. This …
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Design of a 405/430 kHz, 100 kW Transformer with Medium Voltage Insulation Sheets
To achieve higher power density, converters and components must be able to handle higher voltage and current ratings at higher percentages of efficiency while also maintaining low cost and a compact footprint. To meet such demands, medium-voltage resonant converters have been favored by researchers …
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Investigation of a GaN-Based Power Supply Topology Utilizing Solid State Transformer for Low Power Applications
… than its silicon counterparts, making it highly desirable for high-frequency operation in switching converters, which leads to their significant benefits on power density, cost, and system volume. High-density switching converters are being realized with GaN power devices due to their high …
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High Frequency Isolated Power Conversion from Medium Voltage AC to Low Voltage DC
… method is also discussed. Literature survey of high frequency isolated power conversion system which is also called solid state transformer is given including application, topology, device and magnetic transformer. Then developing trend of this research area is clearly shown following by …
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Design and implementation of a universal onboard battery fast charger for transportation electrification applications
… phase shifted DC-DC converter with the designed high frequency transformer is integrated to the proposed AC/DC converter for wide range of output voltages. Simulations of the overall system is presented and a proof-of-concept is also implemented.
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Variable speed constant frequency power conversion with permanent magnet synchronous and switched reluctance generators
… these types of energy is distinct in that their frequency and power vary depending on the speed of the prime-mover. To make use of the variable speed energy, a power processing scheme which transforms the variable speed energy into a constant frequency power is required. There are measures such …
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Topology and Control Investigation of Soft-Switching DC-DC Converters for DC Transformer (DCX) Applications
… data center power supplies, and solid-state transformer (SST) systems, the fixed-ratio isolated DC-DC converter, namely the DC transformer (DCX), has gained significant popularity. Similar to the passive AC transformer, DCX can bidirectionally convey DC power with very high efficiency. Due to …
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High-Frequency Quasi-Single-Stage (QSS) Isolated AC-DC and DC-AC Power Conversion
… commutation circuitry, simple PWM control, and high efficiency and reliability. A new soft-switched single-phase QSS bi-directional inverter/rectifier (charger) topology is derived based on the QSS power conversion concept. A simple active voltage clamp branch is used to clamp the otherwise high …
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Magnetic and Thermal Design of Litzwire 500 kHz Highpower Planar Transformers with Converging Cooling Duct for “dc Transformer” Resonant Converter Applications
… the design and analysis of two Litz wire transformers for a 500 kHz, 18 kW inputparallel outputseries partial power processing converter (IPOS PPP). Because the two power paths in the IPOS PPP operate as “dc transformers” (DCX), both transformers are designed with the goal of leakage …
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An Isolated Micro-Converter for Next-Generation Photovoltaic Infrastructure
… requirements for the micro-converter, such as high CEC efficiency, simple structure, and inherent Galvanic isolation. The circuit is a combination of a traditional PWM boost converter and a discontinuous conduction mode (DCM), series resonant circuit. The DCM operation of the high-frequency …
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High Frequency, High Power Density Integrated Point of Load and Bus Converters
… solution. To meet the demands for lower loss and higher power density, higher efficiency and higher frequency must be targeted in future designs. The objective of this dissertation is to explore and propose methods to improve the power density and performance of point of load modules ranging from …
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Design of High-density Transformers for High-frequency High-power Converters
… One of the design challenges of the high-density power converter design is to have high-density magnetic components which are usually the most bulky parts in a converter. Increasing the switching frequency to shrink the passive component size is the biggest contribution towards …
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Power electronic transformers for AC-AC and AC-DC conversion with reduced number of switches
… a novel reduced-switch Power Electronic Transformer is proposed for three-phase power conversion (three-phase AC to AC as well as three-phase AC to DC). The goal of this project is to reduce the weight and size of the power converter by replacing the low-frequency transformers with …
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High-frequency Power Conversion for Medium Voltage Power Electronics Interfaces
… in recent years. This progress is driven by its high efficiency and improved scalability. Medium voltage power conversion finds applications in various areas such as data centers, electric vehicle fast charging, and smart grids. It enables the reduction of power delivery stages and minimizes the …
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Design and Integration Techniques for High-Frequency PCB-Based Magnetics in Resonant Converters
… continues to seek efficient power delivery and high power density. Resonant converters, especially LLC converters, have been intensively studied and applied in DC-DC converters. One of the most demanding applications for LLC converters is data centers. To date, LLC Resonant converters, are …
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