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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Development of Monolithic Switched-Capacitor Power Converters for Self-Powered Microsystems

Su, Ling January 2009 (has links)
Modern electronics continues to push past boundaries of integration and functional density toward elusive, completely autonomous, self-powered microsystems. As systems continue to shrink, however, less energy is available on board, leading to short device lifetimes (run-time or battery life). Extended battery life is particularly advantageous in the systems with limited accessibility, such as biomedical implants and structure-embedded micro-sensors. The power management process usually requires compact and efficient power converters to be embedded in these microsystems. This dissertation introduces switched-capacitor (SC) power converter designs that make all these techniques realizable on silicon.Four different integrated SC power converters with multiple control schemes are designed here to provide low-power high-efficient power sources. First, a monolithic step-down power converter with subthreshold z-domain digital pulse-width modulation (DPWM) controller is proposed for ultra-low power microsystems. The subthreshold design significantly reduces the power dissipation in the controller. Second, an efficient monolithic master-slave complementary power converter with a feedback controller that purely operates in subthreshold operation region is discussed to tailor for the aforementioned ultra-low power applications. Third, we introduce an efficient monolithic step-down SC power stage with multiple-gain control and on-chip capacitor sizing for self-powered microsystems. The multiple-gain control helps the converter to constantly maintain high efficiency over a large input/output range. The size-adjustable pumping capacitors allow the output voltage to be regulated at different desired levels, with a constant 50% duty ratio. The monolithic implementations in these three integrated CMOS power converters effectively suppress noise and glitches caused by parasitic components due to bonding, packaging and PCB wiring. Fourth, an efficient step-up and step-down SC power converter with multiple-gain closed-loop controller is presented. The measurements and simulation results in these four power converters demonstrate the techniques proposed in this research. The approaches presented in this dissertation are evidently viable for realizing compact and high efficient SC power converters, contributing to next generation power-efficient microsystems designs.
22

A Series-parallel Resonant Converter for Electrochemical Wastewater Treatment

Klement, Kathryn 03 January 2011 (has links)
Advantages of electrochemical wastewater treatment over conventional wastewater treatment include its smaller footprint, modularity, and ability to meet increasingly stringent government regulations. A power supply that can be packaged with an electrochemical stack could make electrochemical wastewater treatment more cost-effective and scalable. For this application, the series and series-parallel resonant converters are suitable power converter candidates. With an output current specification of 100A, the series-parallel resonant converter (SPRC) is superior due to its simpler output stage. The thesis presents the design of a 500W SPRC for a wastewater treatment cell stack. A rudimentary cell model is derived experimentally. The closed loop analysis, controller design and simulation results are presented. The output voltage and current are estimated using sensed quantities extracted from the high voltage, low current primary side. Low voltage experimental results verify the operation of the power stage and voltage estimation circuitry in open loop pulsed operation.
23

A Series-parallel Resonant Converter for Electrochemical Wastewater Treatment

Klement, Kathryn 03 January 2011 (has links)
Advantages of electrochemical wastewater treatment over conventional wastewater treatment include its smaller footprint, modularity, and ability to meet increasingly stringent government regulations. A power supply that can be packaged with an electrochemical stack could make electrochemical wastewater treatment more cost-effective and scalable. For this application, the series and series-parallel resonant converters are suitable power converter candidates. With an output current specification of 100A, the series-parallel resonant converter (SPRC) is superior due to its simpler output stage. The thesis presents the design of a 500W SPRC for a wastewater treatment cell stack. A rudimentary cell model is derived experimentally. The closed loop analysis, controller design and simulation results are presented. The output voltage and current are estimated using sensed quantities extracted from the high voltage, low current primary side. Low voltage experimental results verify the operation of the power stage and voltage estimation circuitry in open loop pulsed operation.
24

ANALYSIS, DESIGN, AND LABORATORY EVALUATION OF A DISTRIBUTED UNIFIED POWER FLOW CONTROLLER CONCEPT

Li, Qiang 01 January 2006 (has links)
A single-phase, buck-boost based, dual-output AC-DC converter is studied in this thesis. The converter has two DC outputs with opposite polarities, which share the same ground with the input power line. The power stage performance, including the input filter, is studied and procedure to select power components is given. The circuit model is analyzed to develop appropriate control. Zerocrossing distortion of the source input current is addressed and a solution is proposed. Experimental results are satisfactory in that a high power factor line current results for steady-state operation.
25

La commande hybride prédictive d’un convertisseur quatre bras / Predictive Hybrid Control on 3-Phase 4-Wire Power Converters

Rachmildha, Tri Desmana 01 October 2009 (has links)
Dans une large variété d'applications industrielles, il existe une demande croissante pour améliorer la qualité de l'énergie fournie par les systèmes électriques. En plus de la fiabilité et de la disponibilité d'énergie électrique, la qualité de la puissance fournie devient maintenant une question importante. Parmi les causes de la pauvre qualité de puissance, les harmoniques sont considérés comme la raison qui contribue à la majorité de pannes de courant. Beaucoup d'efforts ont été développés pour résoudre le problème des perturbations harmoniques comme, par exemple, installer des dispositifs spéciaux tels que les filtres actifs. Ce travail de thèse traite le développement d’une commande directe de puissance utilisant l'approche prédictive hybride. La commande hybride considère chaque vecteur de tension du convertisseur comme une entité discrète qui sera appliquée pour commander un système linéaire continu. Un critère pour calculer le vecteur optimal de tension à appliquer sera établi à partir d’un modèle prédictif. Le vecteur optimal de tension à appliquer pour chaque période de commutation, et le correspondant temps d'application seront utilisés pour approcher la valeur réelle des variables d'état du système au point de référence désiré. Deux théories de puissance instantanées seront employées, p-q et p-q-r, pour une application de filtre active parallèle de puissance dans un système triphasé de 4 fils. Ces théories instantanées de puissance ont été développées pour être appliquées aux systèmes non équilibrés utilisant les variables de puissance pour obtenir les courants qui devraient être injectés par le filtre actif. Le filtre actif produira la puissance réactive demandée par la charge et compensera la composante d'ondulation de la puissance active de sorte que la source livre seulement la puissance active constante. / In a wide variety of industrial applications, an increasing demand exists to improve the quality of the energy provided by electrical systems. Besides the reliability and availability of electric power, the power quality is now becoming an important issue. Among the causes of the poor power quality, the harmonics are included as the reason which contributes the majority of power failures. Many efforts have been developed to solve the harmonics problem as, for instance, to install special devices such as active filters. This research work deals with the development of direct power control using the hybrid predictive control approach. The hybrid control considers each voltage vector of the converter as a discrete entity which will be applied to control a continuous linear system. One criterion to calculate the optimal voltage vector to apply will be established for the predictive control model. The optimal voltage vector to apply for each switching period, and the corresponding application time will be used to approach the actual value of the state variables of the system to the desired reference point. Two instantaneous power theories will be used, i.e. pq0 and pqr instantaneous power theory for a shunt active power filter application implemented in 3-phase 4-wire system. These instantaneous power theories have been developed to be applied to unbalanced systems using the power variables to obtain the currents that should be injected from active filters. The active filter will produce the required reactive power for the load and compensate the ripple component of active power so that the source only delivers constant active power.
26

Výkonový měnič pro svařování stejnosměrným proudem / Power Converter for DC Welding

Vranák, Daniel January 2017 (has links)
The masters thesis was focused on design and realization power converter which should worked as welding machine. It was necessary choose suitable type converter. Next, it was needs design of pulsed transformer, output filter choke and design of semiconductors which were in power part welding machine. It was also designed control and driver circuits. This parts which were used on construct the converter were made and tested too.
27

Wide-Range Highly-Efficient Wireless Power Receivers for Implantable Biomedical Sensors

Ouda, Mahmoud 11 1900 (has links)
Wireless power transfer (WPT) is the key enabler for a myriad of applications, from low-power RFIDs, and wireless sensors, to wirelessly charged electric vehicles, and even massive power transmission from space solar cells. One of the major challenges in designing implantable biomedical devices is the size and lifetime of the battery. Thus, replacing the battery with a miniaturized wireless power receiver (WPRx) facilitates designing sustainable biomedical implants in smaller volumes for sentient medical applications. In the first part of this dissertation, we propose a miniaturized, fully integrated, wirelessly powered implantable sensor with on-chip antenna, designed and implemented in a standard 0.18μm CMOS process. As a batteryless device, it can be implanted once inside the body with no need for further invasive surgeries to replace batteries. The proposed single-chip solution is designed for intraocular pressure monitoring (IOPM), and can serve as a sustainable platform for implantable devices or IoT nodes. A custom setup is developed to test the chip in a saline solution with electrical properties similar to those of the aqueous humor of the eye. The proposed chip, in this eye-like setup, is wirelessly charged to 1V from a 5W transmitter 3cm away from the chip. In the second part, we propose a self-biased, differential rectifier with enhanced efficiency over an extended range of input power. A prototype is designed for the medical implant communication service (MICS) band at 433MHz. It demonstrates an efficiency improvement of more than 40% in the rectifier power conversion efficiency (PCE) and a dynamic range extension of more than 50% relative to the conventional cross-coupled rectifier. A sensitivity of -15.2dBm input power for 1V output voltage and a peak PCE of 65% are achieved for a 50k load. In the third part, we propose a wide-range, differential RF-to-DC power converter using an adaptive, self-biasing technique. The proposed architecture doubles the dynamic range of conventional rectifiers. Unlike the continuously self-biased rectifier proposed in the second part, this adaptive rectifier extends the dynamic range while maintaining both the high PCE peak and the sensitivity advantage of the conventional cross-coupled scheme, and can operates in the GHz range.
28

Technologies de fabrication pour les convertisseurs de puissance intégrés / Technologies for integrated power converters

Yu, Chenjiang 13 December 2016 (has links)
Les convertisseurs électroniques de puissance sont aujourd’hui très largement utilisés dans tous les domaines de la conversion d’énergie. Ils sont des outils désormais incontournables de tout processus de gestion des transferts de l’énergie électriques depuis les puissances les plus faibles (quelques mW) jusqu’à plusieurs dizaines voire centaines de MW. Le domaine de l’électronique de puissance subit actuellement une double mutation liée aux possibilités offertes par les technologies d’intégration d’une part et l’arrivée de nouveaux composants à semi-conducteur de puissance de type grand-Gap d’autre part.Dans cette thèse supportée par l’ANR, nous avons étudié et évalué les potentialités associées à l’intégration de composants de puissance traditionnels (Silicium) et à base de matériaux grands Gap (GaN). Nous avons, pour cela, développé des procédés de fabrication destinés à l’intégration de composants GaN à structure latérale et de composants Silicium à structure verticale. Le contexte applicatif de cette thèse est celui de l’accroissement du niveau d’électrification dans les avions de nouvelle génération.Pour les composants grand Gap de type GaN à structure latérale (basse tension), nous avons proposé un nouveau procédé de report sur substrat céramique (DBC) et nous avons démontré que cette solution permettait d’améliorer considérablement la gestion thermique de ces composants. Sur la base de ces structures, nous avons également présenté et évalué des méthodes de modélisation permettant la conception de ces dispositifs. Cette modélisation, utilisant des méthodes numériques de type éléments finis ou des méthodes analytiques, traite de deux aspects de la conception : la prédétermination du comportement thermique et la prédétermination du comportement électrique et CEM (en ce qui concerne les aspects conduits)Pour les composants à structures verticales (haute tension), nous avons démontré la faisabilité technologique d’une solution alternative aux packagings traditionnels (assemblage sur DBC et connexion par fils de Bonding). Le process proposé permet, par enterrement des puces dans le PCB, de réaliser une interconnexion 3D permettant de réduire les inductances parasites de boucle très largement dues aux inductances parasites des fils de Bonding. Ceci a pu être démontré sur un prototype de convertisseur complet. Ce procédé d’enterrement des puces s’avère donc particulièrement adapté dans le cas de composants à commutation très rapide. / Power Electronic converters are now widely used in all areas of energy conversion. They are tools that cannot be ignored in any process of managing electrical energy transfers from the lowest powers levels (a few mW) to several tens or even hundreds of MW. Power electronics technologies are currently undergoing a double mutation linked to the possibilities offered by integration technologies on the one hand and the arrival of new Wide-Band-Gap power semiconductor components on the other hand.In this thesis supported by the French ANR, we studied and evaluated the potentialities associated with the integration of traditional power components (Silicon) as well as those based on Wide-Band-Gap materials (GaN). We have developed new technological processes for the integration of GaN components with a lateral structure and silicon components with a vertical structure. The application context of this thesis is linked to the problematic of increasing the level of electrification in new generation of aircrafts.For Wide-Band Gap GaN type power devices with a lateral structure (low voltage), we proposed a new method of device-attachment to a metalized ceramic substrate (DBC) and we demonstrated that this solution made it possible to considerably improve the thermal management of these components. On the basis of these structures, we also presented and evaluated modeling methods allowing the design of the whole packaging. This modeling, using numerical tools based on finite element method or analytical equations, deals with two aspects of the design: the predetermination of the thermal behavior and the predetermination of the electrical and electromagnetic behavior (with regard to the conducted aspects)For components with vertical structures (high voltage), we have demonstrated the technological feasibility of an alternative solution to traditional packaging (assembly on a DBC substrate and electrical connection by wire bonding process). The proposed process allows, by embedding the power dies in the PCB, to carry out a 3D interconnection making it possible to reduce the parasitic loop inductances mainly linked to the parasitic inductances of the bondwires. This has been demonstrated on a converter prototype. Embedding power devices is thus particularly suitable in the case of components with very fast switching capabilities.
29

Analysis and Design of Air-Core Transformer Based on Internal Magnetic Flux Density Distribution for High-Frequency Power Converter / 高周波電力変換回路のための内部磁束密度分布に基づく空芯トランスの解析と設計

Hashimoto, Kazuki 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23201号 / 工博第4845号 / 新制||工||1757(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 引原 隆士, 教授 松尾 哲司, 特定教授 中村 武恒 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
30

Single-Submodule Open-Circuit Fault Diagnosis for a Modular Multi-level Converter Using Articial Intelligence-based Techniques

Ke, Ziwei 06 November 2019 (has links)
No description available.

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