This Master`s thesis is focused on through acquaintance of principles of the function circuits with switched capaticors and posibility of their application mainly in frequency filters or signal generators. The origin of the switched capacitor circuits is mentioned at the beginning of the work. There are references to the first scientific work and scientists who have dealt with this issue. Maxwell`s idea: lossy element (resistor) replace with lossless element (switched capacitor) in electric circuit, is further described. In the next chapter of this work are listed types of switching capacitors and their use in simple RC filters and in structures of inverted or noninverted integrators and their application in more complex higher order filters. The advantages and disadvantages of SC circuits versus circuit composed of discrete components are shown. It is also listed a simple low-pass switched RC filter implemented with analogue multiplexer 4053. Using the LTC1043 integrated circuit, which structure and properties are described and analyzed in detail in the work, the 1st order aktive or pasive low and high pass filters were designed and subsequently simulated in the computer simulator OrCAD PSpice v.10. Another chapter deals with the integrated circuits higher order filters, structure and properties of the integrated filter LTC1060 are further analyzed here. Except this IC there are mentioned integrated filters commercially less available from the corporations Linear Technology and Maxim. The main objective of thesis was to propose and establish laboratory device and laboratory measurment focused on the switched capacitor circuits. The laboratory device has been designed with integrated circuits LTC1043 and LTC1060, which is demonstrated by using passive and active integrator, 2nd order band-pass and 4th order band-pass with Chebyshevovou approximation.

Le domaine aéronautique connait de nos jours un engouement sans précédent autour de l’avion plus électrique. L’importance du nombre d’équipements électriques est à un tel point que l’amélioration de leur fiabilité devient incontournable. Actuellement, les composants passifs occupent 75 % des éléments électroniques utilisés en avionique dont la moitié correspond à des condensateurs. Ces derniers doivent donc répondre aux exigences environnementales avioniques assez contraignantes. C’est dans ce contexte que nous nous sommes intéressés particulièrement à l’étude des condensateurs à technologie film utilisant le polypropylène ou le polyester comme diélectrique. Afin de mieux comprendre le comportement fréquentiel de cette technologie, deux modèles fins de condensateurs films ont été développés, permettant ainsi de suivre les évolutions de leurs grandeurs électriques dans des conditions cohérentes avec l’application. Dans un deuxième temps, l’effet des contraintes en tension et en température constantes a été étudié sous la forme de facteurs d’accélération du vieillissement. Cela a été établi par l’intermédiaire de plusieurs essais, permettant d’établir les lois d’évolutions temporelles des paramètres électriques des condensateurs. Comme ces contraintes constantes ne sont pas toujours représentatives des conditions réelles d’utilisation, les cinétiques de dégradation ont été comparées à celles où les condensateurs sont sollicités par de fortes ondulations de courant, seules ou associées à une tension continue. Enfin, la dernière partie de notre travail expose l’utilisation des données expérimentales issues des essais de vieillissement dans un objectif de diagnostic en ligne. Les techniques utilisées assurent l'analyse de la dégradation de ces composants, étape essentielle dans la prédiction de l’état de santé des condensateurs en ligne / Nowadays, aeronautic research field is moving towards a more electric aircraft. Although this evolutionary path offers many advantages from a financial and ecological point of view, the increased power source usage sets additional constraints on the different electrical systems used onboard. Currently, passive components occupy 75% of the overall electronic equipments used in avionics, whose 50% corresponds to capacitors. Consequently, these latter must be able to withstand the harsh avionic operating conditions. In this thesis we were particularly interested in the study of metallized film capacitors technology using polyester or polypropylene as dielectric. A first approach consisted on the modeling of these components as function of frequency in order to study the evolution of their electrical parameters under consistent avionic stresses. These models were also developed on the purpose of tracking the degradation of the capacitors parameters over time. This operation was done by the means of accelerated floating ageing tests, where capacitors were subjected to different constant voltages and temperatures. Original capacitance ageing laws were thus proposed based on the identification of voltage and temperature degradation kinetics. However, since traditional floating ageing tests, do not reflects the normal ageing of the component, degradation kinetics of metallized films capacitors under high ripple currents, alone or combined with a DC voltage across the devices terminals where also studied, and the associated failure mechanisms were identified. A final step consisted on the health monitoring of metallized film capacitors online based on the experimental ageing data

L'objectif de ce travail est de développer et d’étudier une nouvelle classe de fluidesintelligents à base de dispersions colloïdales de carbone, sensibles à un stimulus externe pour desapplications de conversion et stockage d’énergie. Ces stimuli sont de différentes natures : vibrationmécanique, mouvement humain, variation de pression ou écoulement d'un solvant, et peuventaltérer les structures de tels systèmes. Ceci induit une modification de la structure locale desparticules et par conséquent des propriétés diélectriques et électriques. Habituellement, lessuspensions de matériaux carbonés sont étudiées au repos ou séchées. Toutefois, comprendre leurcomportement en flux est essentiel pour de nouvelles applications où ces matériaux sont exploitésdans des conditions dynamiques telle que le stockage d'énergie électrochimique assisté par flux(FAES). Par exemple, les matériaux à base de graphène jouent désormais un rôle important dans lesnouvelles technologies énergétiques. Ils sont utilisés comme additifs conducteurs dans lesassemblages d'électrodes, mais en raison de leur forme anisotrope spécifique, ils permettentégalement d’obtenir des fluides diélectriques sous écoulement.Les cristaux liquides d'oxyde de graphène, en tant que matériau souple électrostrictif, sont étudiéspour la récupération d'énergie mécanique, ainsi que des dispersions de noir de carbone pour lestockage d'énergie.Les propriétés diélectriques et électriques de ces dispersions fluides dans des conditions statiques etdynamiques sont mesurées et analysées. Enfin, l’effet de l’écoulement sur l’orientation et laréorganisation locale des particules et leur comportement diélectrique et électrique sont examinés. / The aim of this work is to develop and study a new class of smart fluids made of colloidalcarbon-based dispersions, which are sensitive to an external stimulus for energy storage orconversion applications. The effect of an external input, such as mechanical vibration, humanmotion, variable pressure, flowing of a solvent, can alter the structures of such systems.Consequently these changes induce modifications of the dielectric and electrical properties. Usually,the suspensions of carbon materials are investigated at rest or dried. However, their flow behavior iscritical when new technologies, which exploit these materials in dynamic conditions such as FAES(Flow-Assisted Electrochemical Energy Storage) are considered. For example, graphene-basedmaterials are now playing a significant role in energy materials. They act as conductive additives inelectrode assemblies, but due to their specific anisotropic shape they also provide a new route toachieve dielectric liquid media.In details, Graphene Oxide liquid crystals as electrostrictive soft material for mechanical energyharvesting and Carbon black dispersions as percolated flowable electrodes for capacitive energystorage are investigated.In particular, the dielectric and electrical properties of these flowable dispersions are studied understatic and dynamic conditions. The effect of the flow-rate on the local orientation and reorganizationof the particles and their related dielectric and electrical behavior are examined.

Les travaux de cette thèse visent à apporter des éléments de solutions au problème de la durée de vie des systèmes pile à combustible (FCS – Fuel Cell System) de type à « membrane échangeuse de protons » (PEM – Proton Exchange Membrane) et se décline sur deux champs disciplinaires complémentaires :Une première approche vise à augmenter la durée de vie de celle-ci par la conception et la mise en œuvre d'une architecture de pronostic et de gestion de l'état de santé (PHM – Prognostics & Health Management). Les PEM-FCS, de par leur technologie, sont par essence des systèmes multi-physiques (électriques, fluidiques, électrochimiques, thermiques, mécaniques, etc.) et multi-échelles (de temps et d'espace) dont les comportements sont difficilement appréhendables. La nature non linéaire des phénomènes, le caractère réversible ou non des dégradations, et les interactions entre composants rendent effectivement difficile une étape de modélisation des défaillances. De plus, le manque d'homogénéité (actuel) dans le processus de fabrication rend difficile la caractérisation statistique de leur comportement. Le déploiement d'une solution PHM permettrait en effet d'anticiper et d'éviter les défaillances, d'évaluer l'état de santé, d'estimer le temps de vie résiduel du système, et finalement, d'envisager des actions de maîtrise (contrôle et/ou maintenance) pour assurer la continuité de fonctionnement. Une deuxième approche propose d'avoir recours à une hybridation passive de la PEMFC avec des super-condensateurs (UC – Ultra Capacitor) de façon à faire fonctionner la pile au plus proche de ses conditions opératoires optimales et ainsi, à minimiser l'impact du vieillissement. Les UCs apparaissent comme une source complémentaire à la PEMFC en raison de leur forte densité de puissance, de leur capacité de charge/décharge rapide, de leur réversibilité et de leur grande durée de vie. Si l'on prend l'exemple des véhicules à pile à combustible, l'association entre une PEMFC et des UCs peut être réalisée en utilisant un système hybride de type actif ou passif. Le comportement global du système dépend à la fois du choix de l'architecture et du positionnement de ces éléments en lien avec la charge électrique. Aujourd'hui, les recherches dans ce domaine se focalisent essentiellement sur la gestion d'énergie entre les sources et stockeurs embarqués ; et sur la définition et l'optimisation d'une interface électronique de puissance destinée à conditionner le flux d'énergie entre eux. Cependant, la présence de convertisseurs statiques augmente les sources de défaillances et pannes (défaillance des interrupteurs du convertisseur statique lui-même, impact des oscillations de courant haute fréquence sur le vieillissement de la pile), et augmente également les pertes énergétiques du système complet (même si le rendement du convertisseur statique est élevé, il dégrade néanmoins le bilan global). / This thesis work aims to provide solutions for the limited lifetime of Proton Exchange Membrane Fuel Cell Systems (PEM-FCS) based on two complementary disciplines:A first approach consists in increasing the lifetime of the PEM-FCS by designing and implementing a Prognostics & Health Management (PHM) architecture. The PEM-FCS are essentially multi-physical systems (electrical, fluid, electrochemical, thermal, mechanical, etc.) and multi-scale (time and space), thus its behaviors are hardly understandable. The nonlinear nature of phenomena, the reversibility or not of degradations and the interactions between components makes it quite difficult to have a failure modeling stage. Moreover, the lack of homogeneity (actual) in the manufacturing process makes it difficult for statistical characterization of their behavior. The deployment of a PHM solution would indeed anticipate and avoid failures, assess the state of health, estimate the Remaining Useful Lifetime (RUL) of the system and finally consider control actions (control and/or maintenance) to ensure operation continuity.A second approach proposes to use a passive hybridization of the PEMFC with Ultra Capacitors (UC) to operate the fuel cell closer to its optimum operating conditions and thereby minimize the impact of aging. The UC appear as an additional source to the PEMFC due to their high power density, their capacity to charge/discharge rapidly, their reversibility and their long life. If we take the example of fuel cell hybrid electrical vehicles, the association between a PEMFC and UC can be performed using a hybrid of active or passive type system. The overall behavior of the system depends on both, the choice of the architecture and the positioning of these elements in connection with the electric charge. Today, research in this area focuses mainly on energy management between the sources and embedded storage and the definition and optimization of a power electronic interface designated to adjust the flow of energy between them. However, the presence of power converters increases the source of faults and failures (failure of the switches of the power converter and the impact of high frequency current oscillations on the aging of the PEMFC), and also increases the energy losses of the entire system (even if the performance of the power converter is high, it nevertheless degrades the overall system).

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A Tomografia de Processos é uma importante ferramenta para diversos setores da indústria. Tal importância vem da necessidade de obter informações sobre determinada propriedade física em regiões de complicado acesso, por exemplo, o interior de um duto. A tomografia é uma ferramenta muito versátil, podendo ser adaptada para investigar diversas propriedades físicas. Entre as diversas modalidades tomográficas está a elétrica, conhecida como Tomografia de Impedância Elétrica (EIT). A EIT pode ainda ser dividida em duas partes: Tomografia de Resistência Elétrica (ERT) e Tomografia de Capacitância Elétrica (ECT). Enquanto a ERT é capaz de distinguir materiais condutivos de não-condutivos, a ECT é capaz de diferenciar dois materiais não-condutivos pela sua permissividade elétrica. A modalidade de tomografia elétrica possui vantagens como: baixo tempo de aquisição, baixo custo e não-radioatividade. Os principais desafios enfrentados na tomografia elétrica são: a dependência da trajetória do campo em relação ao meio (efeito de campo mole) e a pouca quantidade de eletrodos disponı́veis para medições devido às dimensões dos mesmos. Em decorrência do efeito de campo mole, a soma da contribuição individual de cada pixel em uma região é diferente da contribuição real da região, em outras palavras, é um problema não-linear. Devido a pequena quantidade de eletrodos, em geral 8 ou 12, reconstruir uma imagem com resolução prática é um problema mal-posto. Muitos métodos foram propostos para contornar essas dificuldades, grande parte se baseia em um modelo linearizado do sistema e na resolução de um problema inverso. Neste trabalho é proposto um método de reconstrução de imagens com representação esparsa, no qual busca-se reconstruir uma imagem composta de poucos elementos de uma base redundante. Esses elementos são aprendidos a partir de sinais de treinamento e usados como entrada para um modelo de ECT. As respostas, em capacitância, desse modelo formam uma matriz de sensibilidade redundante. Tal matriz pode ser interpretada como uma linearização por partes do problema direto. Para validação desse algoritmo foram realizados experimentos em escoamentos bifásicos ar-água. Os sinais de treinamento foram obtidos com o uso de um sensor de ECT em conjunto com um sensor wire-mesh capacitivo. Os resultados obtidos demonstram a capacidade do método proposto em reconstruir imagens a partir de 8 medições de capacitâncias. As imagens reconstruı́das apresentam melhores resultados, segundo diferentes métricas, quando comparados a outros métodos com representações esparsas. / Process Tomography is an important tool for many sectors of industry. Such importance comes from the necessity of obtaining knowledge of physical properties from hard reaching places, as the interior of a solid object or pipe. Tomography is a very versatile tool, it can be adapted for investigating different physical properties. Among the many tomographic modalities is the electrical, know as Electrical Impedance Tomography (EIT). The EIT can also be divided in two: Electrical Resistance Tomography (ERT) and Electrical Capacitance Tomography (ECT). While the ERT is capable of distinguishing conducting materials from non-conducting ones, the ECT is capable of distinguishing two non-conducting materials by their electrical permittivity. The electrical modality has advantages such as: low acquisition time, low cost and non-radioactive. The main challenges of electrical tomography are: dependency of the trajectory of the field in the medium (effect know as soft-field) and the low number of electrodes available for measurement due to their sizes. As a result of the soft-field effect, the sum of individual contributions of small discrete segments in a given region is different from the contribution of the entire region as one. In other words, the relation between the electrical property and the electrical measurements are non-linear. Due to the small number of measuring electrodes, commonly 8 or 12, reconstructing images with practical resolution is an ill-posed problem. In order to overcome these obstacles, many methods were proposed and the majority are based on the resolution of an inverse problem of a linear model. This work proposes a method of image reconstruction with sparse inducing regularization that seeks to obtain an image representation with only few elements of a redundant basis. The elements of this basis are obtained from training images and used as input of an ECT simulation. The output capacitances of the model make up the columns of a redundant sensitivity matrix. Such matrix can be viewed as a piecewise linearization of the direct problem. For validation purposes, experimental tests were conducted on two-phase flows (air-water). The training signals were obtained from an experiment with a capacitive wire-mesh sensor along with an ECT sensor. The results obtained show that the proposed method is capable of reconstructing images from a set of only 8 capacitance measurements. The reconstructed images show better results, according to different metrics, when compared to other methods that also use sparse representations.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-05T17:06:52Z No. of bitstreams: 1 guilhermemarciosoares.pdf: 5349685 bytes, checksum: 1085aed638a3213e03844d5e5e68f7d1 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-02-26T11:52:22Z (GMT) No. of bitstreams: 1 guilhermemarciosoares.pdf: 5349685 bytes, checksum: 1085aed638a3213e03844d5e5e68f7d1 (MD5) / Made available in DSpace on 2016-02-26T11:52:22Z (GMT). No. of bitstreams: 1 guilhermemarciosoares.pdf: 5349685 bytes, checksum: 1085aed638a3213e03844d5e5e68f7d1 (MD5) Previous issue date: 2014-06-25 / Este trabalho propõe um sistema inteligente de iluminação pública utilizando diodos emissores de luz (LEDs). Neste âmbito, é proposta uma topologia para o acionamento dos LEDs com controle de intensidade luminosa. Além disso, funções adicionais são propostas de modo a expandir o conjunto de funcionalidades da luminária. Para o acionamento dos LEDs foi desenvolvido um conversor baseado na topologia Ćuk operando em modo de condução descontínuo (DCM) com um interruptor estático em série com a carga, sendo uma solução para o acionamento de LEDs de estágio único. Deste modo, este conversor foi projetado para desempenhar simultaneamente as funções de correção do fator de potência e controle da potência na carga. Através da análise da resposta fotométrica dos diodos emissores de luz perante ondulações de baixa frequência em sua corrente, foi possível criar uma metodologia de projeto que evita o uso de capacitores eletrolíticos no circuito de acionamento dos LEDs, aumentando assim a confiabilidade do sistema. A modelagem e o controle do conversor também foram feitas e estão mostradas no trabalho. De modo a controlar e gerenciar o sistema eletrônico da luminária, foi proposta uma arquitetura baseada no microcontrolador TM4C123GE6PM. Este sistema digital é responsável ainda por promover outras funcionalidades como controle automático de intensidade luminosa, proteção do circuito e ainda monitoramento de parâmetros de qualidade de energia da tensão de entrada do conversor, tais como afundamentos e elevações. A fim de avaliar experimentalmente o sistema proposto, foram desenvolvidos um programa de computador capaz de gerenciar as funcionalidades da luminária e um protótipo de 70W deste equipamento. Os resultados experimentais obtidos mostraram um bom desempenho tanto do circuito de acionamento dos LEDs, como das funcionalidades da luminária. / This paper proposes a smart lighting system based on light-emitting diodes (LEDs) for street lighting applications. In this context, a power converter with dimming capability was designed. Furthermore, additional functions are proposed in order to expand the feature set of the luminaire. To drive the LEDs, a topology based on Ćuk converter operating in discontinuous conduction mode (DCM) with an electronic switch in series with the load was proposed. This converter was designed to perform simultaneously the functions of power factor correction and power control, being a single-stage LED driver solution. By analyzing the LEDs photometric response due to low-frequency current ripple, a design methodology that avoids the use of electrolytic capacitors in the proposed converter was developed. The modeling and control of the converter were also done in order to ensure that the system is always operating within the desired specifications. To control and manage the electronic system of the luminaire, it was developed an architecture based on the microcontroller TM4C123GE6PM. Beside the aforementioned functions, this digital system was designed aiming the promotion of other features, such as automatic dimming, protection of the driver and even monitoring some power quality parameters related to the input voltage, such as sags and swells. In order to experimentally evaluate the proposed system, a software, able to manage the luminaire functionalities, and a 70W prototype were built. The experimental results demonstrated a good performance of the LED driver as well as the functionalities of the proposed luminaire.

Made available in DSpace on 2016-08-17T14:53:07Z (GMT). No. of bitstreams: 1 Diomadson Belfort.pdf: 1540332 bytes, checksum: 3100ff3681a43294daea6ee8313b879e (MD5) Previous issue date: 2007-09-05 / In digital measurement systems, signal conditioning circuits have the main functionality of adjusting analog signals for digital conversion. For maximizing the application of a measurement circuit or system, yet considering its integration in a single chip, these circuits must be programmable, in order to serve to different kinds of sensors with diverse output signal characteristics. The main functions of the signal conditioning circuit, in this case, are the amplification and dc level shift of the analog signal. In this master s thesis, an architecture of a signal conditioning integrated circuit with programmable gain and dc level shift, optimized in number of discrete components, using the switched capacitor technique is proposed. The proposed architecture allows the circuit use in differential and single-ended modes, with unipolar and bipolar signals. The design of an integrated circuit is carried out for implementing the proposed architecture using 0.35 mm TSMC CMOS technology, available in the ASIC design kit (ADK) of the Mentor Graphics, IC Nanometer software package. / Em sistemas digitais de medição, circuitos de condicionamento de sinais têm como principal finalidade o ajuste dos sinais analógicos para realização da conversão digital. Para maximização da aplicação de um circuito ou sistema de medição, considerando ainda sua integração em uma única pastilha, esses circuitos têm que ser programáveis, de forma a atender a diversos tipos de sensores com características de sinais de saída diversas. As principais funções do circuito de condicionamento, neste caso, são a amplificação e o ajuste de nível cc do sinal analógico. Nesta dissertação, propõe-se uma arquitetura de um circuito de condicionamento integrado com ajuste de nível cc e ganho programáveis, otimizada em número de componentes discretos, usando a técnica de capacitores chaveados. A arquitetura proposta permite a utilização do circuito nos modos diferencial e de terminação única, unipolar ou bipolar. Um projeto de um circuito integrado é realizado implementando a arquitetura proposta em tecnologia CMOS 0,35 mm TSMC, disponível no ASIC design kit (ADK) do pacote de programas da Mentor Graphics, IC Nanometer.

Use of multilevel inverters are inevitable in medium and high voltage drives. This is due to the fact that the multilevel inverters can produce voltages in smaller steps which will reduce the harmonic content and result in more sinusoidal voltages and currents as compared to voltages and currents from two-level inverters. Due to the device limitations, use of two-level inverters is not possible in medium and high voltage drive applications. Though multiple devices can be connected both in series and parallel to achieve two-level operation, the output voltages still suffer from high harmonic content. Multilevel inverters have multiple DC voltage levels with switches that enable one of the voltage steps to be applied to the load. Due to decrease in step size during each switching instant, output voltages and currents of the multilevel inverters have considerably less harmonic content. As the number of levels increase, the switching step reduces thereby the harmonic content also reduces drastically. Due to their advantages, multilevel inverters have gained lot of acceptance in the industry even at lower voltages. The three main configurations that have gained popularity are the neutral point clamped converter, the flying capacitor converter and the cascaded H-bridge converter. Each converter has its own set of advantages and disadvantages. Based on the requirements of various applications, it is possible to fabricate hybrid multilevel topologies that are combinations of the three basic topologies. Researchers around the world have proposed several such converters for diverse applications so as to suit particular requirements like modularity, ease of control, improved reliability, fault tolerant capability etc. The present thesis explores multilevel converters with single DC link to be used for motor drive and grid connected applications. A novel five-level inverter topology formed by cascading a floating capacitor H-bridge module to a regular three-level flying capacitor inverter has been explored in chapter 2. The three-level flying capacitor inverter can generate pole voltages of 0, VDC /2 and VDC . By cascading it with another floating capacitor H-bridge of voltage magnitude VDC /4, pole voltages of 0, VDC /4, VDC/2, 3VDC /4 and VDC . Each of these pole voltage levels can have one or more switching combinations. However each switching combination has a unique effect on the state of the two capacitor voltages. By switching through redundant switching combinations for the same pole voltage, the two capacitors present in each phase can be balanced. The proposed topology also has an advantage that if one of the devices in the H-bridge fails, the topology can still be operated as a regular three-level flying capacitor inverter that can supply full load at rated power by bypassing the faulty H-bridge. This fault tolerant operation of the converter will enable it to be used in applications like traction and marine drives where high reliability is needed. The proposed converter needs a single DC link. All the required voltage levels can be generated from the single DC link. This enables back to back grid connected operation possible where multiple converters can interact with a single DC link. Various pole voltage switching combination and its effect on individual capacitor has been studied. A control algorithm to balance the capacitor voltages by switching through multiple redundancies for the same pole voltage has been developed. The proposed configuration has been implemented in hardware using IGBT H-bridge modules and the control circuitry is realized using DSP and FPGA. The performance of the drive is verified for various frequencies and modulation indices during steady state by running a three phase induction motor at no load. The stability of the drive during transients has been studied by accelerating the machine suddenly at no load and analyzing the performance of the drive. The capacitor voltages are made to deviate from their intended values and the capacitor balancing algorithm has been verified for its ability to bring the capacitor voltages back to their intended values. The experimental results have been presented and discussed in detail in the chapter 2. In the third chapter a common-mode voltage eliminated three-level inverter using a single DC link has been proposed. The power schematic is similar to the one presented in chapter 2. In this chapter the space vector polygon formed by the three phases of the proposed topology has been presented. The common-mode voltage generated by different pole voltage combinations for same space vector location and the redundant switching state combinations has been studied. The pole voltage combinations with zero common mode voltage have been studied. The switching state redundancies for the the pole voltage have been studied. The space vector polygon formed with the pole voltage combinations has been analyzed. A drive is made with the proposed common-mode voltage eliminated inverter. The performance of the drive is tested for various modulation indices and frequencies by running a three phase squirrel cage induction motor at no load. The transient performance is verified by accelerating the motor suddenly and checking the common-mode voltage along with the capacitor voltages. The results have been presented and discussed in detail in chapter 3. This converter has advantages like use of single DC supply, ability to operate as a regular three level converter in case of failure of one of the H-bridges. The work presented in fourth chapter proposes a novel three phase 17-level inverter configuration which utilizes a single DC supply. The rest of voltages are generated using three floating capacitor H-bridges. The redundant switching combinations for generating various pole voltages and their effect on the capacitors have been studied and suitable capacitor balancing algorithm has been developed. The proposed topology has been realized in hardware and the performance of the drive during steady state has been studied by running an induction motor at various modulation indices and frequencies. The transient response of the drive has been observed by accelerating the motor suddenly under no load. The results have been presented in detail in chapter four. This configuration also needs a single DC link. The advantages of this configuration is in case of failure of any devices in the H-bridge, the drive can be operated at reduced number of levels while supplying full load current. This feature helps the drive to be used in fault tolerant applications like marine and traction drives where reliability of the drive is of prime importance. All the topologies that have been presented in the previous chapters have mentioned about the usage of the proposed genre of topologies use single DC link and hence will enable back to back grid tied inverter connection. In the fifth chapter this has has been verified experimentally. The three phase squirrel cage induction motor is driven by using the seventeen-level inverter drive proposed in chapter four. A five-level active front-end is realized by the converter topology proposed in chapter two. The converter is run and the performance of the drive is studied at various modulation indices and speeds of the motor. Various aspects like re-generation operation, acceleration and other aspects of the drive have been studied experimentally and the results are presented in detail. For experimental setup, Semikron SKM75GB12T4 IGBT modules have been used to realize the power topology. These IGBTs are driven by M56972L drivers. The control circuit is realized using TMS320F2812 DSP along with Xilinx Spartan 3 FPGA (XC3S200) has been used. The voltages and currents are sensed using LEM LV-20P and LA 55-P hall effect based sensors.

Dans le cadre du transport de marchandises par voie ferroviaire, un certain nombre de verrous limitent les efforts consentis pour un fret plus "propre". Des améliorations doivent être faites afin de limiter le nombre de locotracteurs assurant les charges/décharges de marchandises en bout de ligne. Dans cette perspective, FEMTO-ST et Alstom Transport ont pour objectif de concevoir et développer un système de gestion d'énergie pour locomotive électrique hybride. Composée d'un groupe électrogène couplé à des accumulateurs électrochimiques et des super-condensateurs, la locomotive électrique hybride permet d'accroître la souplesse et l'efficacité du transport ferroviaire électrique, tout en réduisant encore son impact environnemental. Cette étude a consisté dans un premier temps à développer une modélisation macroscopique de la chaîne de traction électrique hybride et à proposer une structuration de la commande avec l'identification des capteurs matériels et logiciels nécessaires au contrôle optimal de la chaîne de traction. La caractérisation expérimentale des moyens de stockage a permis l'amélioration comportementale et dynamique des modèles correspondant. Dans un second temps, le contrôle de la tension de sortie d'un hacheur dévolteur a permis d'étudier l'application de la logique floue de type-2 (intervalle et générale) dans le cas d'applications industrielles (relativement simples). Enfin, une gestion innovante des flux d'énergie au sein d'un système plus complexe: locomotive électrique hybride, a été développée. Mettant en œuvre la logique floue de type-2 et des algorithmes s'inspirant de la théorie de l'évolution, cette gestion d'énergie optimale opère en temps réel et sans connaissance à priori du cycle de conduite. La gestion fréquentielle ainsi que le contrôle des états de charge des sources secondaires du véhicule contribuent également à leur bon fonctionnement. / To achieve a "greener" freight transport, efforts are still needed to overcome some technological barriers. New improvements must be carried at to limit the shunting locomotives' use intended for the goods' load/unload. Considering this aim, FEMTO-ST and Alstom Transport decided to conceive and develop an energy management strategy system for hybrid electric locomotives. Such locomotives include a diesel driven generator set which is coupled with batteries and ultra-capacitors. The architecture aims at improving the flexibility, the effectiveness of the electrical railway transport and at reducing the environmental impact of these activities again. Firstly, the study consists in implementing a macroscopic modelling of the hybrid electric powertrain. Then, the control is optimally designed by identifying the hardware and software sensors of the powertrain. The dynamics and the behavior of the secondary sources' models are improved thanks to their experimental characterizations. Secondly, the use of Type-2 Fuzzy Logic (interval and general) controllers permits to study their efficiency in the control of a very simple industrial system: the output voltage of a buck converter. Lastly, based on the obtained results, an innovative management of the system's energy flows is developed in the case of the hybrid electrical locomotive. The use of the type-2 fuzzy logic and evolutionary algorithms permit to optimally perform a real time energy management strategy without a priori knowledge of the duty cycle. The frequency approach and the secondary sources' state of charge control contribute to their efficient use.

A 2T2C ferroelectric memory cell consisting of a select transistor, a read transistor and two ferroelectric capacitors that can be operated either in FeRAM mode or in memristive ferroelectric tunnel junction mode is proposed. The two memory devices can be programmed individually. By performing a combined readout operation, the two stored bits of the memory cells can be combined to perform in-memory logic operation. Moreover, additional input logic signals that are applied as external readout voltage pulses can be used to perform logic operation together with the stored logic states of the ferroelectric capacitors. Electrical characterization results of the logic-in-memory (LiM) functionality is presented.