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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.
1

Análise do conteúdo harmônico na entrada de subestações retificadoras ferroviárias. / Assessment of harmonic content in the entry of railway power supply installations.

Zakowicz, Rafael 04 July 2012 (has links)
O objetivo deste trabalho é realizar medições de distorção de tensão e corrente na entrada de subestações que alimentam sistemas ferroviários e verificar se estas atendem às normas IEEE - 519:1992 e IEC 61000-3-6:2008. Foram realizadas medições durante uma semana nas subestações retificadoras Tietê e Jaraguá, ambas da CPTM. Os resultados das medições foram comparados com simulações computacionais baseadas em um modelo simplificado do sistema de alimentação. / This study reports an experimental assessment of current and voltage distortion at the ac side of railway power supply installations and their compliance with the IEEE-519: 1992 and IEC 61000-3-6: 2008 standards. All experimental measurements were conducted using a commercially available power quality analyzer installed during a week at the CPTM rectifier substations of Tietê and Jaraguá. A simplified model was applied to computer simulations in order to calibrate the model through the comparison with experimental results.
2

Estudo da topologia de motores de fluxo axial de excitação híbrida com foco na utilização em tração elétrica. / Study of hybrid excitation axial flux motor topology for electric traction utilization.

Ademir Pelizari 07 December 2015 (has links)
Os motores de corrente contínua convencionais são muito bem conhecidos pela sua robustez e pelo seu alto nível de controlabilidade, alem do fato de possibilitarem a operação na região de enfraquecimento de campo (modo motor), quando esta situação se fizer necessária. Por estas características, as máquinas de corrente contínua ainda são empregadas nos dias atuais em nichos específicos de utilização. Não obstante, a máquina c.c. apresenta algumas desvantagens, principalmente a intensiva e dispendiosa manutenção eletromecânica necessária para sua operação. Como opção de sanar este problema, surgiram na década de 60, as máquinas elétricas de corrente contínua sem escovas (brushless) com excitação por ímãs permanentes de fluxo trapezoidal. O problema destas máquinas se deve justamente a impossibilidade da variação de fluxo de excitação uma vez que são produzidos puramente pelos ímãs. Sendo assim, este trabalho tem como propósito, o estudo de topologias diferenciadas da máquina elétrica, através de um circuito magnético não convencional para aplicação e utilização em sistemas de tração elétrica para operação na região de enfraquecimento de campo através da variação do fluxo resultante no entreferro. Como objeto de estudo, foi focada a topologia de fluxo axial com excitação híbrida, ou seja, dupla excitação (excitação a ímãs permanentes e excitação elétrica). Para o projeto da topologia proposta, nesta tese, adicionalmente ao método analítico, foram realizadas simulações computacionais para a comparação e refinamento dos resultados das grandezas eletromagnéticas da máquina. / DC motors haves been used for almost two centuries. They are very well known not only its excellent torque response, but also because they can operate at the flux weakening region, when this situation is required. Due these characteristics, nowadays, the dc machines haves been used in specific niches of utilization. Nonetheless, this sort of machine presents a disadvantage, specifically the problem of exhaustive electromechanical maintenance required. In order to solve this type of problem, during the 1960\'s, the permanent magnet trapezoidal brushless dc machines were developed. The problem in this kind of machine is the dificulty to obtain excitation flux variation, since there is only a permanent magnet excitation system. Hence, the aim of this thesis is a study of non conventional electric machines topology for application and utilization in electric traction systems for operation at weakening flux region through the changing of resulting air-gap flux. As purpose of the study, an axial flux hybrid excitation topology was focused, i.e, a double excitation system (a permanent excitation and an electric excitation) to make its operation at the constant power region possible keeping the flux density level in the critical parts of the machine under the saturation point. Additionally, for design the topology proposed, in this thesis, computational simulations were done in order to compare with the results obtained from the analytical method.
3

Análise do conteúdo harmônico na entrada de subestações retificadoras ferroviárias. / Assessment of harmonic content in the entry of railway power supply installations.

Rafael Zakowicz 04 July 2012 (has links)
O objetivo deste trabalho é realizar medições de distorção de tensão e corrente na entrada de subestações que alimentam sistemas ferroviários e verificar se estas atendem às normas IEEE - 519:1992 e IEC 61000-3-6:2008. Foram realizadas medições durante uma semana nas subestações retificadoras Tietê e Jaraguá, ambas da CPTM. Os resultados das medições foram comparados com simulações computacionais baseadas em um modelo simplificado do sistema de alimentação. / This study reports an experimental assessment of current and voltage distortion at the ac side of railway power supply installations and their compliance with the IEEE-519: 1992 and IEC 61000-3-6: 2008 standards. All experimental measurements were conducted using a commercially available power quality analyzer installed during a week at the CPTM rectifier substations of Tietê and Jaraguá. A simplified model was applied to computer simulations in order to calibrate the model through the comparison with experimental results.
4

Estudo da topologia de motores de fluxo axial de excitação híbrida com foco na utilização em tração elétrica. / Study of hybrid excitation axial flux motor topology for electric traction utilization.

Pelizari, Ademir 07 December 2015 (has links)
Os motores de corrente contínua convencionais são muito bem conhecidos pela sua robustez e pelo seu alto nível de controlabilidade, alem do fato de possibilitarem a operação na região de enfraquecimento de campo (modo motor), quando esta situação se fizer necessária. Por estas características, as máquinas de corrente contínua ainda são empregadas nos dias atuais em nichos específicos de utilização. Não obstante, a máquina c.c. apresenta algumas desvantagens, principalmente a intensiva e dispendiosa manutenção eletromecânica necessária para sua operação. Como opção de sanar este problema, surgiram na década de 60, as máquinas elétricas de corrente contínua sem escovas (brushless) com excitação por ímãs permanentes de fluxo trapezoidal. O problema destas máquinas se deve justamente a impossibilidade da variação de fluxo de excitação uma vez que são produzidos puramente pelos ímãs. Sendo assim, este trabalho tem como propósito, o estudo de topologias diferenciadas da máquina elétrica, através de um circuito magnético não convencional para aplicação e utilização em sistemas de tração elétrica para operação na região de enfraquecimento de campo através da variação do fluxo resultante no entreferro. Como objeto de estudo, foi focada a topologia de fluxo axial com excitação híbrida, ou seja, dupla excitação (excitação a ímãs permanentes e excitação elétrica). Para o projeto da topologia proposta, nesta tese, adicionalmente ao método analítico, foram realizadas simulações computacionais para a comparação e refinamento dos resultados das grandezas eletromagnéticas da máquina. / DC motors haves been used for almost two centuries. They are very well known not only its excellent torque response, but also because they can operate at the flux weakening region, when this situation is required. Due these characteristics, nowadays, the dc machines haves been used in specific niches of utilization. Nonetheless, this sort of machine presents a disadvantage, specifically the problem of exhaustive electromechanical maintenance required. In order to solve this type of problem, during the 1960\'s, the permanent magnet trapezoidal brushless dc machines were developed. The problem in this kind of machine is the dificulty to obtain excitation flux variation, since there is only a permanent magnet excitation system. Hence, the aim of this thesis is a study of non conventional electric machines topology for application and utilization in electric traction systems for operation at weakening flux region through the changing of resulting air-gap flux. As purpose of the study, an axial flux hybrid excitation topology was focused, i.e, a double excitation system (a permanent excitation and an electric excitation) to make its operation at the constant power region possible keeping the flux density level in the critical parts of the machine under the saturation point. Additionally, for design the topology proposed, in this thesis, computational simulations were done in order to compare with the results obtained from the analytical method.
5

Machine Pentaphasée A Double Polarité Pour Electrification Du Domaine Des Transports Par Effet Boite De Vitesse Electromagnétique / Double polarity five-phase machine for eleification of transportation by a kind of electromagnetic gearboxctr

Zahr, Hussein 12 December 2016 (has links)
Les machines électriques à aimants, appréciées pour leurs densités énergétiques volumique et massique, équipent la majorité des véhicules électrifiés. Par contre, dans la zone à puissance constante d’un système de propulsion, les commander à pertes maîtrisées, cela en démagnétisant les aimants mais de façon réversible, reste une gageure, particulièrement sous environnement thermique changeant. Les solutions simples pour se prémunir d’une démagnétisation irréversible sont coûteuses: surdimensionner ou ajouter une terre très très rare (Dysprosium).Cette thèse propose d’ajouter à l’approche de la démagnétisation réversible universellement utilisée, celle d’une boite de vitesse électromagnétique. Pour cela on conçoit une machine pentaphasée à aimants.Passer de trois à cinq phases permet alors d’augmenter les paramètres de réglage de l’alimentation électrique et, moyennant approximation, de disposer de deux machines fictives à p et 3p paires de pôles, chacune pouvant contribuer de façon équivalente à la production du couple. Pratiquement, l’utilisation optimale de ces deux machines permet de reconstituer la fonction de boite de vitesse. / Permanent Magnet electrical machines , appreciated for their high power density, equip the majority of the electrified vehicles. However, controlling these machines, in the constant power range of the propulsion system while mastering the losses, with PM reversible demagnetization remains a challenge especially under varying thermal environnement. Proposed solutions aim for protecting PM from irreversible demagnetization are costly: oversizing or using very rare earth PM (Dysprosium).In this thesis, we proposed to add on the reversible demagnetization approach universally used , that of a electromagnetic gearbox. Thus, we design a five phase PM machine.Increasing the phase number from three to five, increases the adjustment parameter of the electrical supply, and allows to have two fictitious machines with p and 3 p poles. Each fictitious machine contributes equivalently in producing torque. Practically, the optimal use of these two machines leads to reconstructing the gearbox function.
6

Concepção de veículo motorizado elétrico modular de acoplamento universal em cadeira de rodas / Conception of modular electric motor vehicle of universal attachment in standard wheelchair

Alves, Júlio Oliveto [UNESP] 08 August 2017 (has links)
Submitted by JÚLIO OLIVETO ALVES null (julio.oliveto@gmail.com) on 2017-08-29T12:48:26Z No. of bitstreams: 1 versão digital - VEÍCULO MOTORIZADO ELÉTRICO MODULAR DE ACOPLAMENTO UNIVERSAL EM CADEIRAS DE RODAS MECANOMANUAL.pdf: 6431267 bytes, checksum: 267c216f343be2e22e3e8daad61fe7a8 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-08-29T13:09:02Z (GMT) No. of bitstreams: 1 alves_jo_dr_guara.pdf: 6431267 bytes, checksum: 267c216f343be2e22e3e8daad61fe7a8 (MD5) / Made available in DSpace on 2017-08-29T13:09:03Z (GMT). No. of bitstreams: 1 alves_jo_dr_guara.pdf: 6431267 bytes, checksum: 267c216f343be2e22e3e8daad61fe7a8 (MD5) Previous issue date: 2017-08-08 / O presente trabalho de pesquisa consiste na concepção de um veículo motorizado elétrico modular de acoplamento universal em qualquer modelo de cadeira de rodas mecanomanual. Trata-se de um equipamento eletro-mecânico, disponibilizado em forma de acessório, com estrutura física simplificada e alta tecnologia eletrônica aplicada capaz de proporcionar ao cadeirante maior liberdade de movimentação sem desgastes físicos. A aliança entre o design inclusivo e a área médica pode se relevar um passo importante na obtenção de produtos direcionados para as necessidades reais de pessoas com condições físicas e psíquicas particulares, melhorando o seu bem-estar e capacidade de execução de atividades no dia a dia. Desta forma, o presente trabalho é direcionado pelos fundamentos do design inclusivo com o principal ponto focal no usuário, mas que apresenta outros dois importantes pilares adotados em sua metodologia de desenvolvimento, sendo eles, o benchmarkig e o estudo de Normas Técnicas aplicadas no desenvolvimento de equipamentos assistivos. São apresentadas as etapas de desenvolvimento, ensaios com base em Normas Técnicas e teste de usabilidade. Busca-se evidenciar todo o processo de design de equipamento, assim como o estudo teórico de estabilidade e montagem do protótipo funcional. Os ensaios baseados na Norma Técnica ABNT NBR ISO 7176 permitem o entendimento do comportamento dinâmico e funcional do protótipo em termos de estabilidade estática, eficácia dos freios, consumo de energia, velocidade máxima, aceleração, desaceleração e capacidade de transposição de obstáculos. Por fim, discute-se a análise de resultados dos ensaios junto aos resultados teóricos calculados e pré-requisitos estabelecidos. / The thesis consists in the conception of a modular electric motor vehicle that can be attached in any model of standard wheelchair. It is an electro-mechanical equipment, available as an accessory, with a simplified physical structure and high applied electronic technology capable of giving the wheelchair greater freedom of movement without physical wear and tear. The union between inclusive design and the medical field can be an important step in obtaining products aimed at the real needs of people with particular physical and psychological conditions, improving their well-being and ability to do their daily activities. In this way, the thesis is guided by the fundamentals of inclusive design with the main focal point in the user, by the way presents two other important pillars adopted in its development methodology, being the benchmarkig and the study of Technical Standards applied in the development of Assistive devices. The stages of development are presented, tests based on Technical Standards and usability testing. The aim of this work is to demonstrate the whole process of equipment design, as well as the theoretical study of stability and assembly of the functional prototype. The tests based on the Technical Standard ABNT NBR ISO 7176 allow the understanding of the dynamic and functional behavior of the prototype in terms of static stability, brake efficiency, power consumption, maximum speed, acceleration, deceleration and obstacle transposition capacity. Finally, we discuss the analysis of the results of the tests together with the calculated theoretical results and established prerequisites.
7

Conception optimale des moteurs à réluctance variable à commutation électronique pour la traction des véhicules électriques légers / Optimal design of switched reluctance motors for light electric traction applications

Ilea, Dan 25 October 2011 (has links)
Le domaine de la traction électrique a suscité un très grand intérêt dans les dernières années. La conception optimale de l'ensemble moteur électrique de traction – onduleur doit prendre en compte une variété de critères et contraintes. Étant donnée la liaison entre la géométrie du moteur et la stratégie de commande de l'onduleur, l'optimisation de l'ensemble de traction doit prendre en considération, en même temps, les deux composants.L'objectif de la thèse est la conception d'un outil d'optimisation appliqué à un système de traction électrique légère qu'emploie un moteur à réluctance variable alimenté (MRVCE) par un onduleur triphasé en pont complet. Le MRVCE est modélisé en utilisant la technique par réseau de perméances. En même temps, la technique de commande électronique peut être facilement intégrée dans le modèle pour effectuer l'analyse dynamique du fonctionnement du moteur. L'outil d'optimisation réalisé utilise l'algorithme par essaim de particules, modifié pour résoudre des problèmes multi-objectif. Les objectifs sont liés à la qualité des caractéristiques de fonctionnement du moteur, en temps que les variables d'optimisation concernent la géométrie du moteur aussi que la technique de commande. Les performances de l'algorithme sont comparées avec ceux de l'algorithme génétique (NSGA-II) et d'une implémentation classique de l'algorithme par essaim de particules multi-objectif.Finalement, un prototype de moteur à réluctance variable est construit et le fonctionnement du MRVCE alimenté depuis l'onduleur triphasé en pont complet est implémenté et les outils de modélisation et d'optimisation sont validés / The interest for the electric traction applications has been growing in the last few years. The optimal design of the electric motor and of the inverter that powers it needs to consider a long list of restrictions and criteria. Because of the fact that the geometry of the motor and the switching strategy are closely linked, the optimization of the traction solution needs to consider both, at the same time.The objective of this thesis is the development of an optimization tool applied for the optimization of an electric traction solution that uses the switched reluctance motor (SRM) fed from a three phase full bridge inverter. The SRM is modeled using Permeance Network Analysis (PNA). The switching technique can be easily integrated in the model, which gives the possibility to run a dynamic analysis. The optimization tool created uses the Particle Swarm Optimization (PSO) algorithm, modified for multi-objective problems. The algorithms performances are compared with those of the Genetic Algorithm, using the NSGA-II multi-objective technique and with a classic version of multiple objective particle swarm optimizer (MOPSO).Finally, a SRM prototype is constructed and the drive solution using a full-bridge three phase inverter is implemented. The modeling and optimization tools are thus experimentally validated
8

Design of power supply system in DC electrified transit railways - Influence of the high voltage network / Dimensionering av likspänningsbanmatningssystem – Inverkan av högspänningsnätet

Seimbille, Denis January 2014 (has links)
Urban rail systems such as subways and trams transport millions of people every day, oering a high level of service. Most of these systems are fed by direct current (DC). The design of the power supply network of DC electried transit railways is of great importance and requires the use of simulation models. The power supply network is composed of a high voltage network (fed with AC) linked to a traction network (fed with DC) by traction substations. Many simulation models ignore the high voltage network in the design process whereas it has a signicant inuence on the results. A Newton-Raphson algorithm is implemented to solve the AC load ow in the high voltage network, and coupled to the existing simulation software Symphonie. Three dierent high voltage network architectures are simulated, and the simulation results are analyzed. The results show that the voltage drop at the AC side of traction substations and the load sharing between them varies signicantly from one architecture to another. In particular, when several traction substations are connected to the same high voltage loop, voltage drops can be signicant for some traction substations. In conclusion, the design of the power supply network of DC electried transit railways requires the simulation of the high voltage network when several substations are connected to the same high voltage loop. / Publika sparburna transportsystem sasom tunnelbanor och lokalbanor transporterar miljontals manniskor varje dag. De esta korta linjer matas med likstrom. Utformningen av stromforsorjningen till dessa system ar avgorande for ett val fungerande , och forutsatter anvandningen av olika matematiska modeller. Detta natverk bestar av ett vaxelstroms hogspanningsnat som omformas till likstrom i era banmatningsstationer langs banan. Dessa matematiska modeller ignorerar dock ofta hogspanningsdelen i modelleringen, varfor resultatet ibland kan bli missvisande. I detta arbete har en belastningsfordelningsalgoritm baserad pa Newton-Raphsons metod implementerats for att skapa en battre modellering av hsgspanningsdelen i den bentliga programvaran Symphonie. Tre olika hogspanningsstrukturer har bearbetats och resultatet visar att spanningsfall och belastningsf ordelning varierar mellan de olika strukturerna. Speciellt nar era transformatorstationer ar kopplade till samma hogspanningssystem, kan spanningsfall vara patagligt for vissa transformatorstationer. Sammanfattningsvis maste utformningen av hogspanningsystemet till likstromsforsorjda jarnvagar utformas med hjalp av anpassade matematiska modeller som tar hansyn till placering av transformatorstationer liksom hogspanningsnatets kapacitet.
9

Fault Diagnosis for Functional Safety in Electrified and Automated Vehicles

Li, Tianpei 25 September 2020 (has links)
No description available.
10

Étude de machines à réluctance variable pour une application de traction électrique : réduction des ondulations de couple et des efforts radiaux / Study of switched reluctance motors for electrical traction application : minimization of torque ripples and radial efforts

Belhadi, M'hamed 25 September 2015 (has links)
Le mémoire traite de la machine à réluctance variable en proposant d'une manière simultanée et du point de vue conception des solutions à ses deux inconvénients majeurs à savoir les ondulations de couple et les efforts radiaux. Les premières se propagent le long de la chaine de transmission diminuant ainsi le confort des usagers et les deuxièmes sont à l’origine d’une nuisance sonore. Dans une première partie et en s’intéressant à une structure axiale caractérisée par une faible force radiale, un bilan sur cette structure est donc établi. En effet, une configuration à deux stators et un rotor est la plus adéquate pour éventuellement remplacer la machine radiale de référence. Cette structure axiale est comparée à cette machine de référence après avoir établi des règles de passage d’une structure à une autre. Un premier passage est effectué en gardant le même encombrement et un deuxième passage en dimensionnant la machine axiale pour satisfaire le même cahier des charges que la machine radiale. Dans une deuxième partie, le travail s’oriente vers la modification de la structure radiale de la machine de référence et son optimisation. Plusieurs modifications sont proposées dont une structure avec une cale magnétique qui est la plus performante. Des optimisations géométriques à l’aide de l’algorithme génétique sur un point de fonctionnement sont ensuite effectuées pour remédier aux deux problèmes. A la fin, un récapitulatif de plusieurs structures optimisées est proposé pour servir de référence. Le choix de la machine la plus adéquate pourra donc être effectué en faisant un compromis entre la maximisation du couple, la réduction de ses ondulations et la réduction des efforts radiaux. / This report deals with switched reluctance motor by offering design solutions to the drawbacks of torque ripples and radial forces in the same time. Torque ripples reduce the user comfort and radial forces are the origin of noise. In the first part, an axial structure characterized by low radial force is analysed. Indeed, an axial configuration with two stators and one rotor is the most appropriate to replace the reference radial machine. Ones the rules of passage from one structure to another are established, the axial structure is then compared to the reference one. A first passage is made by keeping the same volume and a second one by sizing the axial machine with the same specifications as the radial one. In the second part, the work concerns the modification of radial structure of the reference machine and its optimization. Several modifications are proposed including a structure with a magnetic wedge which is the most efficient. Geometric optimization using genetic algorithm are then performed on operating points to remedy the both problems. In the end, several optimized structures are proposed. The choice of the most suitable machine can be done by making a compromise between the torque maximization, reducing its ripples and reducing radial forces.

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