This dissertation looks closely at deployment of thin-film integrated inductors within power electronics, including details on the state-of-the-art technology for such inductors and related packaging techniques. Design challenges for systems using these inductors are discussed in detail, including the current outlook on magnetics development and the impact of these non-linearities on system design. In particular, this work looks closely at effects often left behind in modern discrete-component-based power module design, such as soft core saturation and significant high-frequency losses. In conjunction with the magnetics, a well-known non-linear controller for buck converters is analyzed in-depth for the first time, using frameworks from variable structure and sliding-mode control. This allows for development of a more profound rationale for the heuristic design guidelines that have been heretofore provided for this class of controllers. To verify the theoretical development, a testbench integrated CMOS front-end for a switched-inductor step-down, or buck converter is used to investigate departures of system behavior from the general wisdom around buck converter performance. Two packaging methodologies are explored for integration, and their impact on the design cycle and module lifetimes are discussed in some detail.

Abstract not available

Environmental concerns have renewed the interest in electric vehicles. To gain widespread use, electric vehicles will also have to offer good performance and be reasonably priced. AC drive systems using modern semiconductors can provide efficient operation at the required power levels, but their cost at present is still too high. This paper discusses the development of an AC induction motor drive system which potentially lowers cost by using a digital controller. The controller is shown to implement a high performance field-oriented control, while keeping a low parts count by maximizing use of interface circuits which are integrated onto the microprocessor chip. Cost is further reduced by designing the system to reuse motor control components for battery charging and eliminate the need for external circuits. Experimental results are presented for a low power prototype system. / Graduation date: 1994

Thesis (M.App.Sc.) - Carleton University, 2002. / Includes bibliographical references (p. 175-182). Also available in electronic format on the Internet.

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 29, 2007) Includes bibliographical references.

Fabrication technology, based on MEMS processes, for constructing components for use in switched-mode power supplies are developed and presented. Capacitors, magnetic cores, and inductors based on sacrificial multilayer electroplating are designed, fabricated, and characterized. Characterization of the produced inductors' core losses at high frequency and high flux is presented, confirming the aptness of the featured microfabrication processes for reducing eddy current losses in magnetic cores. As well, the demonstration of the same inductors in DC/DC converters at high switching frequencies, up to 6 MHz, is presented. Initial work addressing the top-down development of a fully-integrated DC/DC converter is presented. As well, the comprehensive advancement of the central process - sacrificial multilayer electroplating - is presented, including the development of a second-generation automated multilayer electroplating system. The advanced sacrificial multilayer plating process is applied to produce microfabricated capacitors, which achieved in excess of 1.5 nF/mm² capacitance density, The fabrication of highly-laminated magnetic cores and power inductors based on sacrificial multilayer electroplating is presented, along with the design and development of a system for characterizing inductor behavior at high-frequency, high-flux conditions. The design and operation of both buck and boost DC/DC converters, switching at up to 6 MHz, built around these highly-laminated-core inductors are presented.

No description available.

Energy-efficient radio frequency (RF) power amplifiers (PAs) are critical and paramount to achieve longer battery life in state-of-the-art portable systems because they typically determine and dominate the power consumption of such devices. In this dissertation, a high-efficiency, linear RF PA with a dynamically adaptive supply and bias current control for code division multiple access (CDMA) and wideband CDMA (WCDMA) is conceived, simulated, and experimentally demonstrated with a discrete PCB-level design and in integrated circuit (IC) form. The PA efficiency is improved by dynamically adjusting both its supply voltage and bias current, there by minimizing its quiescent power dissipation. The PA supply voltage is derived from the battery by a noninverting, synchronous buck-boost switching regulator because of its flexible functionality and high efficiency. Adjusting the PA supply voltage and bias current by tracking the output power, instead of following the complete envelope in large baseband bandwidth wireless applications, is achieved by a converter with a lower switching frequency and consequently higher light-load efficiency, which translates to prolonged battery life. A discrete PCB-level prototype of the proposed system with 915 MHz center frequency, CDMA IS-95 signal having 27-dBm peak-output power resulted in more than four times improvement in the average efficiency compared to a fixed-supply class-AB PA while meeting the required performance specifications. In the IC solution fabricated in AMIs 0.5-micron CMOS process through MOSIS, a dual-mode, buck-boost converter with pulse-width modulation (PWM) control for high power and pulse-frequency modulation (PFM) for low power is designed and implemented to improve the PA efficiency during active and standby operation, respectively. The performance of the dynamically adaptive supply and bias control IC was validated by realizing a 25-dBm, 1.96 GHz center frequency, WCDMA PA over an input supply range of 1.4 4.2 V. The PA with dual-mode power supply and bias control IC showed an average-efficiency improvement of seven times compared to a fixed-supply class-AB PA, which translates to five times improvement in battery life assuming the PA is active for 2 % of the total time and in standby mode otherwise.

No description available.

Cette thèse s'intéresse au transformateur de puissance qui constitue l'élément central de toute alimentation à découpage. La recherche s'articule selon deux axes: l'analyse des champs et le calcul des pertes cuivre d'une part, et la modélisation par schéma équivalent (en vue de réaliser des simulations électriques du convertisseur) d'autre part.<p><p>Selon le premier axe de recherche, l'idée est d'utiliser un logiciel de simulation de champs électromagnétiques par éléments finis pour analyser les champs en deux et en trois dimensions dans le transformateur. Outre une compréhension globale de la répartition des champs, on cherche à analyser finement les pertes cuivre générées dans les enroulements.<p><p>Aux fréquences utilisées dans les alimentations actuelles (typiquement quelques centaines de kilohertz), la densité de courant se répartit en effet de manière non uniforme dans les conducteurs suite aux effets quasi statiques (effet pelliculaire et effet de proximité). Les pertes cuivre doivent donc être calculées avec des outils spécifiques qui en tiennent compte. Or les modèles analytiques classiquement utilisés dans ce but (formules de Dowell et apparentées) reposent sur une analyse unidimensionnelle du transformateur, suivant une hypothèse dont la portée est mal connue et mise en cause par plusieurs auteurs.<p><p>Grâce aux simulations par éléments finis, la thèse dresse un inventaire inédit des effets quasi¬statiques 2D et 3D dans les enroulements. Les différents effets sont expliqués physiquement. La fiabilité des méthodes 1D est analysée et l'erreur commise par celles ci est quantifiée suivant le type d'enroulement et la fréquence. Trois méthodes alternatives de calcul des pertes en deux dimensions sont également analysées et critiquées.<p><p>Pour un type précis d'enroulement (une couche de ruban entre une valeur nulle et une valeur maximale de la force magnétomotrice), une "formule semi empirique" est encore développée. Celle-¬ci rassemble en une seule expression un grand nombre de simulations couvrant toutes les situations géométriques envisageables pour le type d'enroulement considéré. On crée ainsi un outil sans équivalent actuellement, qui allie la rapidité des méthodes 1D à la précision des simulations 2D. La formule semi empirique offre de nombreux avantages pour les concepteurs, dont une forme analytique particulière et la possibilité de réaliser des études paramétriques.<p><p>D'autre part, la thèse montre également que le "facteur de remplissage", notion présente dans la plupart des formules unidimensionnelles de calcul des pertes cuivre, résulte d'une erreur dans l'article de base de Dowell et se révèle donc sans fondement théorique. Ce facteur garde néanmoins une utilité pratique par le fait qu'il reproduit fortuitement certains effets 2D.<p><p>Selon le second axe de recherche, la modélisation, divers schémas équivalents sont analysés. Compte tenu du fait que les transformateurs utilisés dans les alimentations à découpage comprennent généralement plusieurs sorties et voient des formes d'onde fortement chargées en harmoniques, deux types de schémas particuliers sont retenus: le schéma "Coupled Choke Secondaries" (schéma CCS) et les schémas du Laboratoire d'Electrotechnique de Grenoble (schémas LEG). Le schéma CCS est validé sur un transformateur réel et implémenté dans une application conviviale.<p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished