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 18 of 18 for “"high-frequency switching"”.
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High frequency switching parallel processing topology for AC uninterruptible power supply
… the description, analysis and design of a high frequency parallel processing ac uninterruptible power supply. Compared to the standard UPS system used today, the proposed system has higher efficiency, smaller size and less weight, this is due primary to the usage of a high-frequency …
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Design and Development of High-Frequency Switching Amplifiers Used for Smart Material Actuators With Current Mode Control
… presents the design and development of two switching amplifiers used to drive the so-called smart material actuators. Different from conventional circuits, a smart material actuator is ordinarily a highly capacitive load. Its capacitance is non-linear and its strain is hysteretic with …
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Modeling and Design of a Monolithic High Frequency Synchronous Buck with Fast Transient Response
… are more and more strict. Efficient performance, high functionality, small profile, fast transient and low cost are the most wanted features for modern power management ICs, especially for mobile power. In order to reduce profile, the number of external components should be as small as possible, …
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A demonstration of useful electric energy generation from piezoceramics in a shoe
… peak and converted into a useful form using a high-frequency switching technique. The power conditioning circuitry consists of the following stages: Rectification, high-frequency switching (and step-down transformation), CMOS "555" timing and switcher control, low-side output filtering, load …
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PC based simulation software package for an uninterruptable power supply
… to the fore in recent times with the advent of high frequency switching techniques. This project considers such a high frequency operated UPS system. It is modeled, and simulated to provide insight and information for design studies. A framework for the software simulation of a class of UPS is …
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Enabling HF power conversion : magnetic components and a wide voltage range converter
High frequency switching in power converters offers the benefits of high power density and faster transient response; however, high frequency losses have limited efforts to increase frequency into the HF (3-30 MHz) regime. This thesis addresses two of the dominant frequency-dependent loss …
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EMTP simulation of an active filter operating with weak AC distribution system
… loads cause disturbance on the ac bus due to high harmonic load currents. Traditionally passive filters are used for filtering these load harmonics. Recent technological advances have enabled the use of high frequency switching devices in the development of active filtering techniques. In this …
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Sliding Mode Control with Chattering Reduction
… disturbances. However, the discontinuous and high-frequency switching nature of the control law introduces the chattering phenomenon, which leads to potential actuator degradation, alterations to the desired response characteristics and, sometimes, instability during control implementation. …
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Application of High-Power Snubberless Semiconductor Switches in High-Frequency PWM Converters
For many years, power electronics in the high-power area was performed with extremely slow semiconductor switches. These switches, including the thyristor and the Gate Turn-Off (GTO) thyristor, had the capacity to handle very high voltages and currents but lacked the ability to perform high …
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Characterization of various types of power amplifiers
… of various types of power amplifiers and highlights their unique pros and cons among the different topologies. A high-efficiency, high-frequency switching mode power amplifier will be discussed mostly with regard to its design and measurement testing. Moreover, a conventional class E power …
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4H-SiC FinFET devices and modelling
… (SiC) has promising electrical properties in high-voltage, high-frequency switching applications for various power electronics applications. In particular, SiC power MOSFETs have undergone remarkable development and optimisation, turning them into serious competitors to more conventional Si …
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High-Frequency Dimensional Effects in Ferrite-Core Magnetic Devices
… used in power electronics applications where the switching frequency is in the range of several tens of kilohertz to a megahertz. In this range of frequencies the combination of relatively high permeability and relatively low conductivity found in MnZn ferrite helps to minimize the size of …
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Modeling and Mitigation of EMI from Near-Field Coupling Effects in Front-End Power Supplies
… significant advancements in the development of high-density, high-efficiency power supplies. Many of these advancements have been enabled by the widespread commercialization of wide-bandgap (WBG) power semiconductors. The improved performance of WBG devices over traditional silicon devices has …
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Energy efficient control for power management circuits operating from nano-watts to watts
… circuits can play a crucial role in achieving high efficiency and/or minimizing overall system form-factor. In this thesis, power converter circuits, spanning a wide operating range- from nano-watts to watts, are presented while highlighting techniques for using digital control circuits not …
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Robustness of Gallium Nitride Power Devices
… half discusses the robustness of lateral GaN high electron mobility transistor (HEMT), which recently sees rapid adoption among wide range of applications such as the power adapter and chargers, data center, and photovoltaic panels. The absence of p-n junction between the source and drain of …
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Novel load identification techniques and a steady state self-tuning prototype for switching mode power supplies
… are hardly achievable in analog controllers. The high flexibility offered by digital controllers and their capability to implement sophisticated control strategies, together with the programmability of controller parameters, make digital control very attractive as an option for improving the …
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Robustness and Stability of Gallium Nitride Transistors in Dynamic Power Switching
Wide-bandgap gallium nitride (GaN) high electron mobility transistors (HEMTs) are gaining increased adoption in applications like mobile electronics and data centers. Benefitting from the high channel mobility and the high breakdown field of GaN, GaN power HEMTs enable low specific on-resistance …