With the improvements in computer technology, users in utilities expect to receive more advanced functions of their power system management applications by using the data distributed among computer applications. The conventional method of point-to-point interface is not efficient for building large-scale computer systems and is especially difficult for system integration. Integration efforts are carried on to facilitate software applications communicating with others. Defining the same description for a central database and exchangeable data format among applications is the first step for integration. Since current data models in the Common Information Model (CIM) are designed mostly for analyzing the terrestrial transmission power system, they are not sufficient for Shipboard Power Systems (SPS). In order to facilitate software integration in SPS, a fundamentally common semantic for SPS applications needs to be extended from the current CIM. Therefore, these analysis applications for SPS could communicate with each other based on a standard model. In this thesis, a pulsed load model is extended from CIM. This model is a general time dependent pulsed load and the simulation of pulsed railgun load validates the proposed data model. Also, stress upon the power grid caused by the pulsed load is analyzed and the continuous railgun operation is simulated. In addition, new CIM data models are built for passive and active filters to facilitate system simulation and further application. As an active filter is a device that incorporates complicated control strategies, much work focused on finding a general data model to accommodate most common active filters. Finally the simulation for active filter validates the proposed data model.

Modern and future communication and radar systems require highly reconfigurable RF front-ends to realize the vision of Software-Defined Radio (SDR), where a single digitally-enabled radio is able to cover multiple bands and multiple operating standards. However, in the increasingly hostile RF environment, filtering becomes a bottleneck for SDRs as the traditional off-chip filters are fixed frequency and bulky. Therefore, tunable filtering is a critical building block for the reconfigurable RF front-ends and on-chip implementations are needed to meet size and weight constraints. On-chip passive components are lossy, especially inductors, and to fulfill the tunability requirements a number of active circuit techniques, e.g. N-path, Q-enhanced, discrete-time filters etc., have been developed. Most of these active filtering techniques, however, are limited to RF frequency range of few GHz and below. Additionally, these techniques lack or have very limited bandwidth tunability. On the other hand, Q-enhanced tunable LC filtering has the potential to be implemented at Microwave frequencies from 4~20 GHz and beyond. In this dissertation, a number of Q-enhanced parallel synthesis techniques have been proposed and implemented to achieve high-order, frequency tunable, and wide bandwidth tunable filters. First, a tunable 4th-order BPF was proposed and implemented in Silicon Germanium (SiGe) BiCMOS technology. Along with center frequency tuning, the filter achieves first ever reported 3-dB bandwidth tuning from 2% to 25%, representing 120 MHz to 1.5 GHz of bandwidth at 6 GHz. A new set of design equations were developed for the 4th-order parallel synthesis of BPF. A practical switched varactor control scheme is proposed for large tuning ratio varactors to reduce the nonlinear contribution from the varactor substantially which improves the tunable LC BPF filter linearity. Second, parallel addition and subtraction techniques were proposed to realize tunable dual-band filters. The subtraction technique is implemented in SiGe BiCMOS technology at X and Ku bands with more than 50 dB of out-of-band attenuation. Finally, a true wideband band-reject filter technique was proposed for microwave frequencies using parallel synthesis of two band-pass filters and an all-pass path. The proposed band-reject scheme is tunable and wide 20 dB attenuation bandwidths on the order of 10s of MHz to 100s of MHz can be achieved using this scheme. The implementation of the proposed parallel synthesis techniques in silicon technology along with measured results demonstrate that Q-enhanced filtering is favorable at higher microwave frequencies. Therefore, such implementations are suitable for future wireless communication and radar systems particularly wide bandwidth systems on the order of 100s of MHz to GHz. Future research includes, high-order reconfigurable band-pass and band-reject filters, automatic tuning control, and exploring the parallel synthesis techniques in Gallium Nitride (GaN) technology for high RF power applications. / PHD

Reactive power is critical to reliable operation of the modern AC power system. There is a plethora of motor-loads, transformers, and power-electronic loads connected to the power grid, which consume reactive power for normal operation. Transmission lines also consume reactive power when they are loaded above their surge impedance loading (SIL). Reactive power can exact opportunity cost due to reduced capacity of the lines to carry real power, which in turn lowers revenue. Most transmission owners (TOs) levy large penalties against load serving entities (LSEs), industrial facilities, and other end-use customers, who consume more than their allotted amount, as measured by their power factor. These penalties are to incentivize their customers to meet their reactive power needs locally as well as to recuperate the TOs' financial losses. Harmonic pollution is another factor that prevents the optimal operation of the grid and the connected loads. Harmonics are attributable to proliferation of the diode-rectifier- or thyristor-rectifier-interfaced loads such as variable speed ac drives and power supplies in server farms, electric arc furnaces, and other non-linear loads, which are widely employed by the industrial sector. With wider adoption of harmonic-rich loads by the consumer sector as well, such as HDTVs and compact fluorescent lamps (CFLs), greater level of triplen harmonics associated with single-phase loads are also increasingly seen on the distribution grid. The increasing penetration of renewable resources and electrification of light-duty vehicles are expected to further aggravate the stresses and congestion on the utility grid. Reactive power compensation is necessary for supporting the AC grid and maintaining a healthy voltage stability margin. Compensation can also enhance the utilization of system capacity, lower system losses, provide fault ride-through, and enable a quick fault recovery. Existing VAR and harmonic compensation technologies are either too expensive or inadequate to meet the dynamic needs of the modern and the future power system. This dissertation presents a novel class of Dynamic VAR and Harmonic Compensators (DVHCs) for supplying or absorbing reactive power and providing harmonic filtering, where the compensation is in shunt with the line and the load. The underlying concept is based on augmenting a static or passive component like a capacitor or an inductor with a direct AC converter and imbuing the passive component with dynamic properties. The direct AC converter can be configured as a buck, a boost, or a buck-boost. A `fail-normal' switch is an integral part of the DVHCs that bypasses the converter when it fails, preserving the original functionality and the reliability of the passive component. The DVHCs are modular and scalable such that they can be employed in applications ranging from residential and industrial with voltages less than 480 V, to power distribution level with voltages as high as 35 kV. The Dynamic Inductor (D-IND) and the Dynamic Capacitor (D-CAP) are subclasses of the DVHCs. As the applications for supplying leading VARs are more prevalent, the primary focus of this work is on the buck, the boost, and the buck-boost configurations of the D-CAP. To understand the characteristics and operation of the DVHCs, this work has developed time-domain models for analyzing the transient and dynamic behavior; frequency-domain models for understanding the harmonic interactions and the steady-state relationships between switch duty and current harmonics; and small-signal models for studying the dynamics of the converter due to various perturbations. The small-signal models also enable extraction of transfer functions in designing controllers and assessing stability margins. Control architectures and techniques are presented for effectively controlling the D-CAP when commutating the semiconductor devices with both high and low switching frequencies. In modularly scaling the DVHCs to higher voltages, three medium-voltage topologies are discussed. They are based on series-connecting fractionally-rated devices, AC flying capacitors, and series cascading multiple two-level cells. These implementations allow direct connect to the medium-voltage grid, thereby obviating the use of transformers, and subsequently reducing the losses, cost, complexity, and footprint. A novel AC snubber concept is proposed to provide safe commutation of the AC switches, fault tolerance by managing the energy trapped in parasitics and filters, and to enable dynamic and static voltage sharing when integrated around the series-connected devices. Design equations for selecting and rating the devices and components in the buck, the boost, and the buck-boost configurations of the D-CAP are presented. Three sets of example designs, with one at low-voltage and two at medium-voltage, are discussed to demonstrate the typical size and ratings of the various components under realistic operating conditions. Measurements and the related discussions of a 40 kVA buck D-CAP prototype built to validate the effectiveness of the proposed concepts are presented.

L’alimentation de charges non linéaires par une source d’alimentation, dans un réseau électrique, est fréquemment soumise à des perturbations et/ou déséquilibres du courant d’alimentation reçu par la charge. Les perturbations du courant d’alimentation désignent la présence d’harmoniques dans le courant d’alimentation, celui-ci n’étant alors pas sinusoïdal, ainsi que la présence d’une puissance réactive trop importante circulant sur le réseau. Les déséquilibres du courant d’alimentation se traduisent, dans un réseau polyphasé, par une mauvaise répartition des courants d’alimentation dans les différentes phases induisant un courant non nul dans le neutre côté source. En outre, dans un réseau électrique de type réseau public de distribution, ces perturbations ou déséquilibres peuvent être soumis à une réglementation du fournisseur d’énergie, c’est ainsi qu’il est utile de mettre en place un dispositif efficace pour minimiser ces perturbations et déséquilibres afin d’améliorer la qualité de l’énergie électrique. Le filtrage actif est une solution efficace qui consiste à injecter un courant adapté sur le réseau pour réduire les perturbations. Toutefois, les solutions actuelles ne permettent pas d’équilibrer les courants d’alimentation de manière efficace, et peuvent même s’avérer inefficaces pour réduire les perturbations si les tensions d’alimentation sont déséquilibrées. En outre, ces solutions ne sont généralement pas utilisable à la fois en monophasé ou en polyphasé, ni avec un fil de neutre. Le travail faisant l’objet de cette thèse vise à proposer une loi de commande générique, c’est-à-dire adaptable au cas monophasé, triphasé, polyphasé, pour un filtrage actif parallèle dont les performances (THD, facteur de déséquilibre, ..) sont améliorées par rapport à l’art existant surtout lorsque le réseau de distribution est perturbé. La recherche de solutions simples à implanter et robustes dans leur performance fait également partie de nos objectifs. La démarche est conduite par la voie de la simulation numérique et les propositions sont validées en laboratoire via une maquette expérimentale raccordée sur le réseau basse tension. A noter que les objectifs font apparaitre un caractère méthodologique fort, donnant lieu à de nombreuses déclinaisons tant par la nature du réseau (monophasé, triphasé, avec ou sans neutre, ..) que par les caractéristiques des perturbations (charges non-linéaires, déséquilibres, perturbations,....). / Feeding non-linear loads by a power source in an electric network is frequently subject to disturbances and / or unbalances in the supply current received by the load. The disturbances of the supply current denote the presence of harmonics, its waveform being non sinusoidal as well as the presence of too much reactive power circulating in the network. The unbalances in the supply current in a polyphase network (including three phase) manifest by a bad repartition of these supply currents in different phases resulting in a non-zero current in the neutral line at the source side. In addition, in a public distribution electrical network, these disturbances or unbalances may be subject to additional charges by the energy supplier, it is thus useful to implement an effective system to minimize these disturbances and unbalances in order to improve the quality of electrical energy. The active filter is an effective solution that consists in the injection of a suitable current into the network to reduce disturbance. However, the present solutions of active filters do not help to balance the supply currents efficiently, and may even be ineffective in reducing the disturbances if the supply voltages are unbalanced. Moreover, proposed solutions are generally not adapted to both single-phase or polyphase, or with a neutral wire. The work in this thesis aims to propose a generic control strategy for a shunt active filter, i.e. suitable for single-phase three phases and polyphase, whose performance (THD, unbalance factor...) are improved compared to the existing state of the art especially when the distribution system is disturbed. The quest for solutions simple to implement and robust in their performance is also part of our objectives. The proposed approach is conducted using computer simulation and validated on a laboratory experimental model connected to the low voltage network. Note that the objectives uncover a strong methodological trait, giving rise to many declensions by the nature of the network (single phase, three phases with or without neutral ...)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The growing global demand for electricity, increasing scarcity of the conventional energy sources and the need to reduce environmental impacts contributed to the pronounced development of new technologies based on clean and renewable energy sources. In this context, the wind power is the technology that has had a greater development in recent decades. This source has played an important role in the advancement of alternative sources in the world energy matrix, because the technology is already consolidated and is economically viable. Accompanying the technological development of the alternative sources, the induction generator has stood out among the generators with the technology best suited to generating electricity for isolated energy systems. With this motivation, this thesis proposes a new configuration for an isolated wind energy conversion system using variable speed turbines, in which the induction generator is electronically excited by means of a static compensator. Also, the generator is associated to a shunt active filter for compensation of non-linear and unbalanced loads, and with a battery bank for energy storage and DC bus stabilization. It is also discussed the main problems with the induction generator related to the magnetization characteristic and its dynamic model, and the proposed solutions to mitigate these problems. The results confirm the effectiveness of the proposed wind energy conversion system, showing its operational capability with variable load and variable turbine speed. Finally it is presented the main conclusions of this work and suggestions for future works in the same line of research. / O crescente aumento da demanda mundial de energia elétrica, a escassez cada vez maior das fontes convencionais de energia e a necessidade de redução dos impactos ambientais contribuíram para o acentuado desenvolvimento de novas tecnologias baseadas em fontes limpas e renováveis. Neste contexto, a energia eólica foi uma das tecnologias que mais se desenvolveu nas últimas décadas. Esta fonte tem desempenhado importante papel no avanço das fontes alternativas na matriz energética mundial, pois é uma tecnologia já consolidada e viável economicamente. Acompanhando o desenvolvimento tecnológico das fontes alternativas, o gerador de indução tem se destacado dentre as tecnologias de geradores mais adequadas para sistemas isolados de geração de energia elétrica. Com esta motivação, esta tese propõe uma nova configuração de conversão de energia eólica isolada, utilizando turbinas de velocidade variável, na qual o gerador de indução é excitado eletronicamente por meio de um compensador estático. Ainda mais, o gerador é associado a um filtro ativo shunt para a compensação de cargas não-lineares e desbalanceadas e a um banco de baterias para armazenamento de energia e estabilização do barramento cc, comum aos conversores. São discutidos os principais problemas relacionados ao gerador de indução para esta aplicação através da característica de magnetização e do seu modelo dinâmico, com as soluções propostas para mitigar estes problemas. Os resultados práticos e de simulação obtidos comprovam a efetividade da configuração de conversão de energia eólica proposta, mostrando a capacidade de operação do gerador com carga variável e velocidade variável da turbina. Por fim são apresentadas as principais conclusões e sugestões para trabalhos futuros na mesma linha de pesquisa.

This master’s thesis deals with the advanced universal modern active elements, such as the current and voltage conveyors. The problem with small bandwidth has been fixed due to the quick development in recent years. Current and voltage conveyors are still being researched. The good properties of conveyors promise their possible commercial usage in the future. For the research of current conveyors we can use parts of other integrated circuits and thus get elements with similar properties. This thesis suggests how to make an active filter using the DBTA and FDBTA elements which were created by “combination” of the universal current and voltage conveyor. Simulations were carried out on selected circuits containing the DBTA to verify their properties. It was for finding out about their behaviour in real applications that the circuits were constructed. This enabled the comparison of the results acquired from the simulation programs with the ideal behaviour of the elements and with the models simulating real properties against the values acquired by measurements of the circuits.

Cette thèse s’intéresse au problème de la qualité de l’énergie électrique sous l’angle particulier des harmoniques, leurs sources, leurs effets et les solutions permettant de les réduire. Deux solutions sont principalement considérées, les convertisseurs à indice de pulsation élevé et les filtres actifs. Ce travail a été mené en faisant porter l’accent sur le réseau électrique thaïlandais. C’est ainsi qu’une présentation de l’évolution de la façon dont l’électricité est produite, transportée et distribuée en Thaïlande est effectuée avant de décrire les contraintes imposées sur les harmoniques. Les différents systèmes de liaison à courant continu haute tension (CCHT) actuellement installés dans le monde sont rappelés avant de décrire en détails les différents composants et le contrôle de la liaison 300-600 MW existant entre la Thaïlande et la Malaisie. Après avoir ensuite présenté les différentes solutions envisageables de réduction des harmoniques, un exemple de réalisation, l’une des premières en Thaïlande utilisant un contrôle numérique, est détaillé afin d’illustrer les avantages de ce type de solution. La thèse se termine sur la présentation d’une méthode originale de modélisation des convertisseurs à indice de pulsation élevé. Cette modélisation repose sur une solution analytique exacte du problème d’état qui est considéré sur le plus petit intervalle permettant, en utilisant des propriétés de symétrie, de reconstruire la période de fonctionnement du dispositif. Le modèle ainsi développé donne des informations sur le fonctionnement du système tant dans les domaines fréquentiel que temporel / The problem of quality of electrical energy is the main object of this thesis. This problem is considered especially from the point of view of harmonics, sources, effects and solutions to reduce them. Two main solutions are considered, multi-pulse converters and active filters. This work is developed with a particular emphasis on the Thai electrical network. Then, the production, transmission and distribution system of electricity in Thailand and the harmonics regulations are presented. The different types of HVDC interconnection systems which are installed in the world today are detailed before presenting the 300/600 MW Thailand-Malaysia HVDC interconnection. After presenting the different possible solutions to avoid harmonics, a realized example, one of the first one developed in Thailand with a numerical control, is detailed to show the advantages of such a solution. The thesis ends on the presentation of an original modelling method of multi-pulse converters. The model is based on an exact analytical solution of the state problem which is considered on the smallest interval, which can, by using property of symmetry, rebuild the whole period. The result model gives the full information on the operation of the whole device both in time and frequency domains

This paper introduces a high-gain, low-noise band-pass filter system for detection/amplification of small signals. In addition, related theory and methodology are described for a specific design implementation. Simulation and experimental results are presented and discussed. The purpose of the implemented design was to construct a band-pass filter system with 102 dB gain and with an output noise level of less than 0.8V. The design of the high-gain band-pass filter system was achieved mainly with the help of Filter Pro, LTSpice IV, and Multisim 12. The thesis provides important support for the project Marker Locator and constitutes a valuable reference for future active filter system design and small signal detection/amplification. / Marker Locator

Ce travail de thèse entre dans le cadre de projets nationaux et internationaux de radioastronomie d'une manière générale et en particulier dans celui de SKA (Square Kilometre Array). La conception de circuits intégrés d’applications spécifiques devient de plus en plus importante dans ce domaine. La première étape de ce travail consiste à une étude bibliographique sur les inductances actives intégrées et leurs principales applications dédiées à la radioastronomie. Cette étude a permis de faire un état de l'art. Cet état de l'art a fait ressortir que l'intégration de certaines fonctions s'avère particulièrement difficile voire impossible dès lors que l'utilisation d'une inductance est nécessaire. Ceci est essentiellement dû à la taille importante des inductances. Parmi ces fonctions, nous avons le filtrage, certains types de transceivers, le temps de retard, etc. Or ces fonctions sont très importantes dans une architecture de radiofréquence propre aux réseaux d'antennes phasées. Ce travail de thèse est donc consacré à l'étude et la conception de ces différentes fonctions à l'aide des inductances actives basées sur des topologies à gyrateurs en technologie SiGeC 0,25 μm afin de palier aux problèmes d'intégration. Une des finalités de cette thèse est aussi de montrer que la consommation de ce procédé d'intégration n’est pas si excessive pour ces applications, par rapport à l’utilisation d’inductances localisées intégrées occupant une surface importante sur le substrat. Ce dernier point sera un résultat très important pour les projets où la très haute intégration à bas coût est nécessaire, point clé de réussite des réseaux phasés denses du projet international SKA. / This thesis work is part of national and international projects of radio-astronomy in general and in particular that of the SKA (Square Kilometre Array). The design of integrated circuits for specific applications is becoming increasingly important in this field. The first step in this work is a bibliography study on integrated active reactors and their main applications dedicated to radio astronomy. This study allowed making a state of the art. This state of the art has highlighted that the integration of some functions is made especially difficult by the need to use an inductor. This is mainly due to the large size of passive inductors. These functions include the filtering function, some transceivers types, the time delay, etc. But, they are very important in radio-frequency architecture owing to phased array antennas. This thesis propose the study and design of these different functions using active inductors based on gyrators topologies in SiGeC 0.25 μm technology in order to overcome the integration problems. One of the aims of this thesis is to show that the consumption of this integration process is not so excessive for these applications, compared to the use of integrated located inductors occupying a large area on the substrate. This last point is a very important result for projects where high integration at low cost is necessary, key point of the success of dense phased array in the SKA international project.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-03-02T11:39:15Z No. of bitstreams: 1 fredericotoledoghetti.pdf: 2816885 bytes, checksum: 98c4c49d919a94d51a94ff86a91c33a1 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-06T19:32:09Z (GMT) No. of bitstreams: 1 fredericotoledoghetti.pdf: 2816885 bytes, checksum: 98c4c49d919a94d51a94ff86a91c33a1 (MD5) / Made available in DSpace on 2017-03-06T19:32:09Z (GMT). No. of bitstreams: 1 fredericotoledoghetti.pdf: 2816885 bytes, checksum: 98c4c49d919a94d51a94ff86a91c33a1 (MD5) Previous issue date: 2009-05-26 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / É apresentado, neste trabalho, um estudo sobre topologias alternativas de fontes ininterruptas de energia do tipo Delta, para o emprego em cargas monofásicas de até 1kVA. O estudo prevê a inserção de um conversor CC-CC entre o conversor shunt e o banco de baterias. Tal modificação em relação à UPS do tipo Delta convencional otimiza o projeto do banco de baterias e requisita um menor número de células em série para sua confecção. Além disso, a proposta elimina o uso de transformadores de baixa freqüência, considerados em alguns trabalhos anteriores, o que também contribui para a redução do peso e volume do sistema. Duas diferentes topologias para o conversor CC-CC foram investigadas e comparações de desempenho e viabilidade foram realizadas. A topologia que apresentou melhor desempenho nos quesitos custo, volume e peso, foi selecionada para testes em bancada. Ao final, resultados simulados e práticos são apresentados para validação do modelo. / This dissertation presents a study on single-phase Delta-UPS topological alternatives for low power and low cost applications. The proposed topology has a DC-DC converter connected between the shunt inverter and the battery bank/series converter DC terminals, respectively. This modification will allow the downsizing of the DC battery bank as well as the removing of the series converter transformer. Two different topologies of the DC DC converter were investigated and a comparative study among them will be accomplished. Simulation results are presented and experimental results will be included to validate the proposed study.