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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.
241

Estudo e comparação de sistemas de geração eólica utilizando DFIG e PMSG / Study and comparation of wind energy systems using DFIG and PMSG

Corrêa, André da Silva 20 February 2015 (has links)
Made available in DSpace on 2016-12-12T17:38:33Z (GMT). No. of bitstreams: 1 Andre da Silva Correa.pdf: 3150015 bytes, checksum: 8df17c41e03f4cea1d464cb6c5d5b970 (MD5) Previous issue date: 2015-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Given the increased contribution of wind farms under complementarity the generating units of electricity derived from petroleum, thermoelectric or hydroelectric energy matrix constituents of countries around the world, this dissertation investigates the advantages and disadvantages between the two main topologies currently used by rogue wind generation. Comparisons between the Doubly Fed Induction Generator and Permanent Magnet Generator are developed in order to establish the different dynamic behavior of each type of wind unit. The constituent parts of wind turbines are studied, performed the modeling and usual control methods are discussed. The simulations were performed in a computer program Matlab / Simulink® whose control models were developed according to the literature, as well as the respective block diagrams for each model. / Diante do crescimento da contribuição dos parques eólicos em regime de complementaridade às unidades geradoras de energia elétrica derivadas de petróleo, termoelétricas ou hidroelétricas constituintes da matriz energética de países espalhados pelo mundo, a presente dissertação de mestrado investiga as vantagens e desvantagens entre as duas principais topologias utilizadas atualmente para geração eólica. São estabelecidas comparações entre o Gerador de Indução Duplamente Alimentado e o Gerador de Ímãs Permanentes, a fim de se estabelecer os diferentes comportamentos dinâmicos de cada tipo de unidade eólica. São estudadas as partes constituintes de aerogeradores, realizadas as modelagens e discutidos os métodos de controle usuais. As simulações foram realizadas em programa computacional Matlab/Simulink®, cujos modelos de controle foram desenvolvidos de acordo com a literatura, assim como os respectivos diagramas de bloco para cada modelo.
242

Influência do efeito de extremidade de atuadores eletromagnéticos lineares nas indutâncias

Boff, Ben Hur Bandeira January 2018 (has links)
Este trabalho demonstra que o efeito de extremidade existente em atuadores eletromagnéticos lineares pode ter influência significativa nas indutâncias próprias, mútuas e síncronas, com valores dependentes da posição que podem ser utilizados para monitoração da posição axial da armadura. O estudo é aplicado a um atuador eletromagnético linear tubular de ímãs permanentes com duplo arranjo de quase-Halbach e bobina móvel, que foi concebido para fins de uso em sistemas de suspensão eletromagnética ativa e semi-ativa. A partir da revisão de literatura apresentada, classificou-se o efeito de extremidade de máquinas lineares síncronas de ímãs permanentes quanto aos tipos, causas, consequências e técnicas de mitigação (caso seja necessário). Adicionalmente, os tipos de controle sem sensores são exemplificados a fim de se identificar maneiras possíveis de adequar algum ao atuador em estudo. São apresentados casos de trabalhos na literatura que utilizam o controle sem sensores em máquinas que possuem indutâncias com comportamento semelhante. Em termos de análise, a distribuição do fluxo magnético no atuador é estudada e um modelo semianalítico é elaborado para calcular o valor das indutâncias com base nos dados de fluxo magnético obtido por simulação numérica. Logo, modelos numéricos completos e parametrizados do atuador são elaborados para simulação transiente e magnetostática e a partir destes as indutâncias são obtidas. As indutâncias também são medidas experimentalmente e na análise dos resultados as incertezas de medição são calculadas e um projeto de experimento é apresentado. Os resultados dos modelos semianalítico e numérico apresentam boa concordância com os resultados experimentais. Por fim, a adequação do atuador para futura aplicação de controle sem sensores é discutida tendo como base a variação de indutâncias devido ao efeito de extremida. / This work demonstrates that the end effect in linear electromagnetic actuators can have a significant influence on the self-, mutual and synchronous inductances, with positiondependent values that can be used to measure the axial position of the armature. The study is applied to a linear synchronous electromagnetic actuator with two arrangements of quasi- Halbach permanent magnets and moving coil, which was designed for use in active and semiactive electromagnetic suspension systems. Based on the literature review presented, the end effect of permanent magnet synchronous linear machines was classified with regard to: types, causes, consequences and mitigation techniques (if necessary). In addition, the types of sensorless control methods are exemplified in order to identify a possible method to be applied to the actuator under study. It was found in the literature that sensorless control was applied to machines that have inductances with similar behavior. In terms of analysis, the distribution of the magnetic flux in the actuator is studied and a semi-analytical model was developed to calculate the value of the inductances based on the data of magnetic flux obtained through numerical simulation. Thus, the complete parametrized numerical models of the actuator were built for transient and magnetostatic simulation, and from these the inductances were obtained. The inductances are also measured experimentally, and in the analysis of the results the measurement uncertainties are calculated and a design of experiments is presented. The results of the semi-analytical and numerical models show good agreement with the experimental results. Finally, the suitability of the actuator for future application of sensorless control is discussed based on the variation of inductances due to the end effect.
243

Construção, acionamento e ensaios do motor bifásico de imã permanente no rotor (MBIPR) / not available

Rafael Borelli 10 June 2005 (has links)
Visando uma opção de substituição, onde for possível e aplicável, do motor de indução monofásico, este trabalho relata o estudo teórico, a construção, o acionamento e os ensaios de um motor bifásico com ímã permanente no rotor, de baixa potência, utilizando imãs de ferrita na confecção do rotor. / This work shows the theoretical studies, building, driving systems and tests of a small-power double-phase motor with ferrite permanent-magnet in the rotor, based on the original structure of a single-phase induction motor. The objective is to create an option to replace the single-phase induction motor where it is possible and applicable.
244

Voltage Stabilization Control of Wide-Speed-Range Permanent-Magnet Synchronous Generator Systems

Miao, Dongmin 14 December 2016 (has links)
DC power systems have a constant DC-link voltage, as well as the advantages such as high stability, high efficiency, small size and light weight; therefore, they are widely used in stand-alone power systems, e.g. the power systems in aircrafts and automobiles, isolated wind power generation systems, etc. Permanent-Magnet Synchronous Generators (PMSGs) possess the advantages including high power density, high efficiency, and high control precision, and have obtained great attention and have been widely used in military, inductry, and daily life. Pulse Width Modulation (PWM) rectifier has been one of the main power conversion topologies thanks to its full controllability. The key point in the dissertation is to study the DC power system consisting of a PMSG to be the main power input device and a PWM rectifier to be the main power conversion topology. The objective of control is to output a constant DC-link voltage in a wide PMSG speed range. Since the PM-excited flux linkage is constant, when the PMSG is working at a high speed, field-weakening is needed to stabilize the stator voltage, further to stabilize the DC-link voltage. Hybrid excitation may be used to realize the field-weakening, but it has complex structure; no auxiliary devices are needed in the field regulation with the armature current, and can be easily realized with the PWM recifier and field-regulation control strategies. In this dissertation, the typical applications of the DC power systems are first introduced, with a comprehensive analysis and elaboration on the relevant research throughout the world. The research work is focused on the DC power system and its stabilization control, which is composed of a PMSG and a PWM rectifier. The involved research content in this dissertation includes the following aspects: 1. DC power system design with a wide-speed-range PMSGAs for the common DC power systems, PMSG with high power density, high efficiency is selected to the system power input device, usually with a variable-speed prime mover. The PWM rectifier with fully controlled switches is chosen to be the power conversion topology, which converts the AC power generated by PMSG into DC power, and supplies the DC load after the DC filter. The matching between the system requirements and the generator parameters are determined. Through finite-element analysis (FEA), a PMSG with strong field-weakening ability and suitable for wide-speed-range operation has been designed and manufactured, and the system test bench has been built based on dSPACE. 2. Study, analysis, optimization and experimental verification of the traditional control strategiesAccording to the PMSG designed in part 1, the DC-link model has been built, as well as the control model of the traditional control strategies, e.g. field-oriented control (FOC), direct torque control (DTC), and the effectiveness of the DC-link voltage stabilization control has been verified in a wide speed range. The theory of active damping has been proposed and analyzed, and has been utilized in the DC-link voltage control. When the load on the DC-link changes, the dynamic response of the DC-link voltage has been greatly accelerated, and it recovers quickly to its reference value. In the meantime, the performance influence of the prime mover speed on the actual system test bench should be considered. Finally, the performance of FOC and DTC has been compared and analyzed. 3. Analysis and experimental verification of the direct voltage control (DVC), and the comparative study of all the studied control strategiesThe derivation process of DVC has been theoretically analyzed: the inner current loops in FOC have been eliminated to obtain the direct voltage field-oriented control (DVFOC); the reference value of d-axis voltage in DVFOC has been replaced by the product of the stator voltage calculated by the speed and the load condition, and the sine value of load angle generated by the DC-link voltage PI controller, in order to form the DVC-1. Further, the DC-link voltage PI controller directly outputs the reference value of load angle and it becomes DVC-2. Finally, the comparative study has been carried out among all the studied control strategies. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished
245

Die Bedeutung der Segregations- und Oxidationsneigung Seltener Erden für die Einstellung hartmagnetischer intermetallischer Phasen in SmCo-basierten Nanopartikeln

Schmidt, Frank 18 April 2018 (has links) (PDF)
Aufgrund der sehr hohen magnetokristallinen Anisotropiekonstante eignet sich besonders die Phase SmCo5 für zukünftige Festplattenmedien mit hoher Speicherdichte. Durch die starke Oxidationsneigung und die gegebene chemischen Ähnlichkeit anderer Seltenen Erden ist es eine Herausforderung hartmagnetische SmCo-basierte Nanopartikel mittels Inertgaskondensation herzustellen. Zudem bestimmt die Oberflächenenergie maßgeblich die Eigenschaften von Nanopartikeln, sodass ein Element mit einer geringen solchen energetisch bevorzugt die Oberfläche bildet. Diese Arbeit zeigt auf, wie die sauerstoffbasierte Oxidation und die unterschiedlichen Oberflächenenergien der legierungsbildenden Elemente die Struktur, die Morphologie und die chemische Verteilung der Elemente innerhalb der Nanopartikel beeinflussen und so die Legierungsbildung einer hartmagnetischen Sm(Pr)Co-Phase steuern. Mithilfe von aberrationskorrigierter, hochauflösender Transmissionselektronenmikroskopie in Verbindung mit Elektronenenergieverlustspektroskopie werden Morphologie, Elementverteilung und Struktur von unterschiedlich hergestellten Sm(Pr)Co-Nanopartikeln untersucht und analysiert. Die auftretende Segregation der Seltenen Erden an die Oberfläche der Nanopartikel wird zum einen auf eine sauerstoffinduzierte, zum anderen auf eine intrinsische Segregation, also eine durch unterschiedliche Oberflächenenergien der legierungsbildenden Elementen hervorgerufene Segregation zurückgeführt. Anhand eines entwickelten geometrischen Modells wird zwischen den beiden Ursachen der Segregation unterschieden. Das Verständnis um die kausalen Zusammenhänge der Segregation lässt den Schritt zur Herstellung hartmagnetischer intermetallischer SmCo-basierter Nanopartikel zu. Hierzu werden speziell Nanopartikelagglomerate geformt und optisch in einem Lichtofen erhitzt, sodass die Primärpartikel in den Agglomeraten versintern und schließlich das resultierende sphärische Partikel kristallisiert. HRTEM-Aufnahmen und Elektronenbeugung bestätigen die erfolgreiche Herstellung von SmCo5- und Sm2Co17-basierten Nanopartikeln. Die Koerzitivfeldstärke dieser Partikelensembles beträgt 1,8T und einem Maximum in der Schaltfeldverteilung bei 3,6T. Die magnetischen Eigenschaften spiegeln die analysierten strukturellen, morphologischen und chemischen Eigenschaften der Nanopartikel wider.
246

Développement de capteurs logiciels de position pour la commande de la machine synchrone à aimants permanents / Soft sensor design for sensorless control of permanent magnet synchronous machines

Omrane, Ines 14 January 2014 (has links)
Le travail de recherche présenté dans ce mémoire concerne le développement de capteurs logiciels de position pour la commande de la machine synchrone à aimants permanents. La commande vectorielle de la MSAP nécessite une connaissance précise de la position rotorique. Traditionnellement, cette position est obtenue à partir de l’utilisation d’un capteur mécanique.Depuis des années, l’attention de la communauté scientifique s’est portée sur la limitation du nombre de capteurs vu que leur présence, non seulement augmente le coût et la complexité matérielle totale, mais aussi réduit sa fiabilité avec une sensibilité additionnelle aux perturbations extérieures. Dans une première partie, nous présentons plusieurs types de capteurs logiciels deposition pour la MSAP. En fonction du régime de fonctionnement de la machine, nous proposons le capteur, selon nous, le mieux adapté pour une application automobile. Ce capteur est basé sur le couplage intelligent entre un observateur et un capteur logiciel basé sur la technique d’injection de signaux. Dans une deuxième partie, nous proposons une méthode simple et rapidepermettant l’estimation de la résistance et des inductances statoriques à l’arrêt. La méthode proposée, basée sur la technique d’injection de signaux de haute fréquence, exploite la mise en oeuvre des filtres à variable d’état afin d’obtenir un modèle linéaire par rapport aux paramètres. La combinaison de l’identification à l’arrêt et du capteur logiciel permet une bonne estimationde la position de la MSAP sur une large plage de vitesse y compris les basses vitesses et à l’arrêt. Nous abordons également certains aspects de commande de robustesse vis-à-vis de l’ensemble des paramètres incertains de la machine, mais ce de manière plus prospective. / This thesis focuses on the development of soft sensors for position control of the permanent magnet synchronous machine. Vector control of PMSM requires accurate knowledge of the rotor position. Traditionally, this position can be obtained from a mechanical sensor. Many years ago, the attention of the scientific community has focused on reducing the number of sensorsbecause their presence not only increases the cost and the total hardware complexity, but also reduces its reliability with an additional sensitivity to external disturbances. As a first step, we present several known types of soft sensors for PMSM. We present the complete design of a soft sensor for speed measurement of permanent magnet synchronous motor. The rotor speedand position can be estimated in a wide speed range even at low speed and standstill. We introduce two soft sensors operating in two different ranges of speed. Secondly, a simple method based on high frequency signal injection and exploiting the implementation of state variable filters to obtain a linear model with respect to the parameters is presented. Thus, a simplifiedprocedure of identification based on a least squares algorithm can be used. In an automotive application, the PMSM parameters can change due to temperature variation and aging of the material. Therefore, the coupling of the hybrid soft sensor and the simplified pocedure of identification provides a good estimate of the PMSM position over a wide speed range including standstill. We also consider a new approach to the robust control of the PMSM, but just as a newtrack for further investigations.
247

Vers une conception optimale des chaînes de traction ferroviaire / Toward optimal design of railway drivetrains

Cantegrel, Martin 27 November 2012 (has links)
Cette thèse aborde la conception optimale des chaînes de traction par l'exemple d'une chaîne de traction pour métro. Les données d'entrée de la conception d'une chaîne de traction sont la performance attendue et l'encombrement des équipements nécessaires. Pour aider le concepteur, l'outil informatique donne aujourd'hui la possibilité de construire une grande variété de modèles. D'autre part, les algorithmes d'optimisation permettent de trouver les configurations optimales. Ces possibilités ont été exploitées au cours de ce travail. Les modèles développés permettent d'estimer un large nombre de critères. A travers l'exemple de ces modèles, la méthode de conception suivie est détaillée dans le rapport. D'un point de vue technique, la chaîne de traction proposée est détaillée dans le dernier chapitre / This thesis deals with the optimal design of electric drivetrains. A drivetrain for metro is taken as an example. The input data for the design are the expected performance and the size of the required equipments.To assist the designer, the computing tool now gives the opportunity to build different sort of models. In addition, optimization algorithms allow finding optimal configurations. This work is an attempt to exploit these possibilities. The design models are used to value a large number of criteria. Through the example of these models, the design method followed is detailed in the document. From a technical point of view, the proposed drivetrain is detailed in the last chapter
248

Contribution au développement d’un concept d’hybridation énergétique : structures de commande d’un système intégré éolien-hydrolien / Contribution to the development of an energy hybrid concept : control structures of a wind-tidal hybrid integrated system

Stevenson, Pierre 13 March 2015 (has links)
Ce mémoire traite de la problématique d’hybridation éolienne-hydrolienne. Elle pose d’abord l’hypothèse d’une éolienne basée sur une Machine Synchrone à Aimants Permanents (MSAP) et une hydrolienne utilisant une Machine Asynchrone à Double Alimentation (MADA). Puis, elle présente la modélisation des différents éléments qui composent chacune des chaines de conversion, de la turbine à la connexion au réseau en passant par la machine électrique et les convertisseurs statiques. Des stratégies de commande y sont aussi développées. Celles-ci permettent d’extraire le maximum d’énergie tout en tenant compte des limites des systèmes. La thèse étudie également deux possibilités de couplage d’une éolienne et hydrolienne qui toutes deux utilisent une MSAP. Les résultats de simulation obtenus des modèles que nous avons développés dans l’environnement Matlab/Simulink/ SimpowerSystem permettent de valider les stratégies de commande utilisées et de conclure qu’un bon choix serait d’opter pour le couplage au niveau du bus continu. / AThis thesis addresses the problem of wind-tidal turbines hybridization. It first raises the hypothesis of a wind turbine based on Synchronous Permanent Magnet Machine (PMSM) and a tidal using a Double-Fed Induction Generator (DFIG). So, it presents the modeling of different elements that make up each system studied, from the turbine to the network connection through the electric machine and static converters. Control strategies are also developed. These are used to extract the maximum energy while taking into account the limitations of the systems. The thesis also examines two possible coupling of wind and tidal turbines which both use a PMSM. The simulation results of the models that we have developed in Matlab / Simulink / SimpowerSystem allow to validate the control strategies and conclude that a good choice would be to opt for coupling to the DC bus.
249

Design And Analysis Of Digital Controllers For High Performance Sensorless PMSM Servo Drives

Lourde, R Mary 10 1900 (has links) (PDF)
No description available.
250

Position Sensor-less Schemes For Vector Control Of Permanent Magnet Synchronous Machine

Sugantha, K 11 1900 (has links) (PDF)
This thesis deals with the modelling, simulation and control of Permanent Magnet Synchronous Machines (PMSM) used specially in electric and hybrid vehicles. With the availability of fast semiconductor switches and high speed processors, Vector controlled drives are gaining popularity. One disadvantage of this type of control however, is the need for high cost, high resolution sensors (encoders) for determining the rotor position. Position sensorless schemes have evolved over a decade and this thesis addresses this issue. Two schemes have been proposed for the elimination of encoders in vector controlled drives. One is a semi-sensored scheme wherein a combination of low cost hall sensors and a digital position estimator gives the position information. In the second scheme, a reduced order observer called Luenbuerger observer has been used to estimate speed and rotor angle. The problem of finding rotor angle at standstill has also been dealt with. This thesis also discusses the difference in simulating a BLDC (Brushless DC) and PMSM machine. An experimental set-up consisting of MOSFET inverter and TMS320LF2407 DSP based digital controller was developed in the laboratory to implement the control algorithms. Two PMSM machines were procured from a two-wheeler manufacturer to set up the rig. Simulations were done in MATLAB/ Simulink (Off-line) and Xilinx XC3S400 (in real-time) to verify the concepts. Simulation and experimental results are finally compared.

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