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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.
51

Análise e projeto de um motor de relutância chaveado com o auxílio do método dos elementos finitos. / Analysis and design of a switched reluctance motor using the finite-element method.

Paula, Pedro Pereira de 19 October 1993 (has links)
Este trabalho se insere num contexto de desenvolvimento da capacitação para aplicações de motores de relutância chaveados, com ênfase aos aspectos eletromagnéticos do acionamento. Inicialmente, são apresentados os principais aspectos construtivos do motor e de funcionamento do seu conversor. São discutidos os fluxos de energia do acionamento e sao apresentadas as suas características operacionais, bem como as possibilidades para o seu controle. Foi desenvolvida uma metodologia de projeto embasada numa formulação empírica e no método dos elementos finitos, implementado através do programa flux2d. Desta forma, foi projetado um protótipo para desenvolver meio newton-metro a três mil rotações por minuto. A formulação empírica baseia-se na adoção de diversas hipóteses simplificadoras do circuito ferromagnético. O método dos elementos finitos foi empregado com a finalidade da obtenção de um refinamento do dimensionamento do motor. O protótipo projetado foi fabricado e testado. Os objetivos dos ensaios foram a confrontação com os diversos valores calculados no projeto e a verificação do seu desempenho em diversas condições de carga. Finalizando o trabalho, os resultados obtidos são analisados, ressaltando-se os aspectos relevantes ocorridos durante o seu desenvolvimento. São também apresentadas, as atividades subsequêntes previstas. / This work is related to the development activities of switched reluctance motors, mainly on their electromagnetic characteristics. The motor\'s basic construction features and the converter\'s operation characteristics are showed, as well as, the energy flows, performance aspects and the effects of the control parameters. The principal elements of motor desigm are discussed. A method of design is developed based on empirical formulas and on finite elements method (using the software FLUX2D). Thus, a prototype was designed with ratings of 0,5 Nm at 3000 rpm. The empirical formulas are developed on a simplified model of the motor and taking into account the referred author\'s experience. The finite elements method was used with the aim of getting a design refinement, as well as, the static torque characteristics, inductances and flux as a function of rotor position and current. The prototype was built and tested. The tests were conducted to compare the actual with the designed parameters and to evaluate the performance characteristics. Finally, the results are analysed and the main facts observed during the development of the work are reported. The next planned activities are also showed.
52

Análise e projeto de um motor de relutância chaveado com o auxílio do método dos elementos finitos. / Analysis and design of a switched reluctance motor using the finite-element method.

Pedro Pereira de Paula 19 October 1993 (has links)
Este trabalho se insere num contexto de desenvolvimento da capacitação para aplicações de motores de relutância chaveados, com ênfase aos aspectos eletromagnéticos do acionamento. Inicialmente, são apresentados os principais aspectos construtivos do motor e de funcionamento do seu conversor. São discutidos os fluxos de energia do acionamento e sao apresentadas as suas características operacionais, bem como as possibilidades para o seu controle. Foi desenvolvida uma metodologia de projeto embasada numa formulação empírica e no método dos elementos finitos, implementado através do programa flux2d. Desta forma, foi projetado um protótipo para desenvolver meio newton-metro a três mil rotações por minuto. A formulação empírica baseia-se na adoção de diversas hipóteses simplificadoras do circuito ferromagnético. O método dos elementos finitos foi empregado com a finalidade da obtenção de um refinamento do dimensionamento do motor. O protótipo projetado foi fabricado e testado. Os objetivos dos ensaios foram a confrontação com os diversos valores calculados no projeto e a verificação do seu desempenho em diversas condições de carga. Finalizando o trabalho, os resultados obtidos são analisados, ressaltando-se os aspectos relevantes ocorridos durante o seu desenvolvimento. São também apresentadas, as atividades subsequêntes previstas. / This work is related to the development activities of switched reluctance motors, mainly on their electromagnetic characteristics. The motor\'s basic construction features and the converter\'s operation characteristics are showed, as well as, the energy flows, performance aspects and the effects of the control parameters. The principal elements of motor desigm are discussed. A method of design is developed based on empirical formulas and on finite elements method (using the software FLUX2D). Thus, a prototype was designed with ratings of 0,5 Nm at 3000 rpm. The empirical formulas are developed on a simplified model of the motor and taking into account the referred author\'s experience. The finite elements method was used with the aim of getting a design refinement, as well as, the static torque characteristics, inductances and flux as a function of rotor position and current. The prototype was built and tested. The tests were conducted to compare the actual with the designed parameters and to evaluate the performance characteristics. Finally, the results are analysed and the main facts observed during the development of the work are reported. The next planned activities are also showed.
53

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.
54

Étude et conception d'un groupe motopropulseur électrique à faibles niveau vibratoire et sonore pour véhicule électrique. Aspects "contrôle - commande" / Study and design of an electric powertrain with low vibration and noise levels for electric vehicles. "Control – command" aspects

Arab, Mohammad-Waseem 30 September 2015 (has links)
Dans un contexte mondial régi par de multiples facteurs économiques, énergétiques et environnementaux, la transition vers des modes de transport à zéro émission polluante semble inévitable. De ce fait, les constructeurs automobiles s’investissent de plus en plus dans le développement de groupes motopropulseurs électriques afin d’anticiper les besoins du marché. Parmi les différentes technologies de machines électriques considérées pour cette application, la Machine à Réluctance Variable à Double Saillance (MRVDS) présente des caractéristiques très attractives pour le milieu industriel.Les travaux présentés dans cette thèse visent à élaborer des solutions qui répondent aux points qui bloquent encore l’adoption de la MRVDS dans les véhicules électriques. Dans un premier temps, la commande en couple d’une MRVDS destinée à la traction électrique est analysée. En prenant en considération les exigences imposées par l’application envisagée, une stratégie de commande en couple est développée en intégrant deux méthodes complémentaires sur le plan de fonctionnement de la MRVDS choisie.Dans la deuxième partie, l’asservissement en courant est abordé. Les problématiques du contrôle propres à la MRVDS à forte dynamique de courant sont d’abord identifiées. Ensuite, deux régulateurs de courant, qui répondent à différents conditions d’implantation, sont présentés et validés par simulation.La dernière partie de cette thèse aborde le problème des à-coups d’accélération induits à basse vitesse et de leurs répercussions sur l'agrément de conduite. En effet, ce type de motorisation électrique introduit un nouvel aspect sur cette problématique. Une loi de commande anti-à-coups, composée de deux actions, est développée. Les simulations ont montré la conformité de la performance obtenue en utilisant la loi de commande proposée avec le cahier des charges industriel visé. / In a global context governed by multiple economic, energetic and environmental factors, the transition towards transportation modes with zero polluting emissions seems inevitable. Hence, automotive manufacturers are investing increasingly in the development of electric powertrains in anticipation of the market needs. Among the different electric motors technologies considered for this application, the switched reluctance motor (SRM) presents attractive characteristics for the industry.The work presented in this thesis aims to elaborate solutions in response to the points still hindering the adoption of the SRM in electric vehicles. First, torque regulation of an SRM intended for an electric traction is analyzed. Taking into consideration the requirements of the application in hand, a regulation strategy is developed through the integration of two methods which complement each other over the studied SRM range of operation.In the second part, the subject of current regulation in the SRM is discussed. The issues related to current regulation in SRMs disposing of high current dynamics are firstly identified. Then, two current regulators, each adapted to different implementation conditions, are presented and validated through simulations.The last part of this thesis discusses the acceleration jerks induced at very low speeds and their repercussions on driving comfort . Indeed, electric traction introduces a new aspect on this rather classic issue. An anti-jerk control law, composed of two control actions, is developed. Simulations have shown the conformity of the performance obtained with the proposed control law with the target industrial specifications.
55

Aspectos de projeto, simulação e operação de geradores e motores de relutância chaveados. / Aspects of design, simulation and operation of switched reluctance generators and motors.

Paula, Pedro Pereira de 03 August 2000 (has links)
A finalidade deste trabalho é desenvolver uma contribuição ao projeto de geradores e motores de relutância chaveados. A primeira etapa do projeto consiste no dimensionamento inicial da máquina através de métodos analíticos convencionais [01]para, em seguida, desenvolver o seu refinamento usando o Método dos Elementos Finitos acoplado com as equações de circuitos elétricos. Inicialmente, é apresentada uma abordagem atualizada dos aspectos construtivos e operacionais deste equipamento, comuns aos dois modos de funcionamento, bem como dos aspectos relevantes da metodologia computacional utilizada. Apresentam-se, em seguida, os resultados das simulações conduzidas para a obtenção das características de torque estático, do fluxo concatenado e das indutâncias, em função da posição angular do rotor e da corrente, as suas implicações no projeto e a sua utilização para a definição das condições operacionais dinâmicas a serem simuladas. Em seguida, são apresentados os resultados das simulações em regime permanente e em transitórios operacionais da máquina elétrica funcionando de uma forma integrada com o seu conversor eletrônico dedicado. No fechamento deste trabalho, estes resultados são discutidos e comparados com alguns ensaios realizados. Apresenta-se também os possíveis desdobramentos para a continuidade do projeto deste tipo de equipamento. O enfoque essencial deste trabalho é a máquina elétrica e os seus resultados propiciam também uma orientação para a definição dos requisitos de projeto do conversor eletrônico e do sistema de controle. / This work aims to provide a contribution to the project of switched reluctance generators and motors. The first stage of the project consists of initial dimensioning of the machine through conventional analytical methods[1] followed by its refinement by using the Finite-element Method coupled with circuit equations. An updated approach on the constructive and operational aspects common to both the ways of the equipment, as well as relevant aspects of the computational methodology used are initially presented. Results of simulations carried out to obtain torque characteristics, flux-linkage and inductance, as a function of angular position of rotor and current, their implications in the project and their use to define dynamic operational condition to be simulated are then showed. Sequentially, results of the steady-state and transients operational simulations of the electric machine working in an integrated way with its dedicated electronic converter are presented. In the closing of this work, these results are discussed and compared to some of the tests performed. Related subjects for continuation of the project of this type of equipment are also presented. The main focus of this work is the electric machine and its results also provide an orientation to the definition of requirements to the project of electronic converter and control system.
56

Aspectos de projeto, simulação e operação de geradores e motores de relutância chaveados. / Aspects of design, simulation and operation of switched reluctance generators and motors.

Pedro Pereira de Paula 03 August 2000 (has links)
A finalidade deste trabalho é desenvolver uma contribuição ao projeto de geradores e motores de relutância chaveados. A primeira etapa do projeto consiste no dimensionamento inicial da máquina através de métodos analíticos convencionais [01]para, em seguida, desenvolver o seu refinamento usando o Método dos Elementos Finitos acoplado com as equações de circuitos elétricos. Inicialmente, é apresentada uma abordagem atualizada dos aspectos construtivos e operacionais deste equipamento, comuns aos dois modos de funcionamento, bem como dos aspectos relevantes da metodologia computacional utilizada. Apresentam-se, em seguida, os resultados das simulações conduzidas para a obtenção das características de torque estático, do fluxo concatenado e das indutâncias, em função da posição angular do rotor e da corrente, as suas implicações no projeto e a sua utilização para a definição das condições operacionais dinâmicas a serem simuladas. Em seguida, são apresentados os resultados das simulações em regime permanente e em transitórios operacionais da máquina elétrica funcionando de uma forma integrada com o seu conversor eletrônico dedicado. No fechamento deste trabalho, estes resultados são discutidos e comparados com alguns ensaios realizados. Apresenta-se também os possíveis desdobramentos para a continuidade do projeto deste tipo de equipamento. O enfoque essencial deste trabalho é a máquina elétrica e os seus resultados propiciam também uma orientação para a definição dos requisitos de projeto do conversor eletrônico e do sistema de controle. / This work aims to provide a contribution to the project of switched reluctance generators and motors. The first stage of the project consists of initial dimensioning of the machine through conventional analytical methods[1] followed by its refinement by using the Finite-element Method coupled with circuit equations. An updated approach on the constructive and operational aspects common to both the ways of the equipment, as well as relevant aspects of the computational methodology used are initially presented. Results of simulations carried out to obtain torque characteristics, flux-linkage and inductance, as a function of angular position of rotor and current, their implications in the project and their use to define dynamic operational condition to be simulated are then showed. Sequentially, results of the steady-state and transients operational simulations of the electric machine working in an integrated way with its dedicated electronic converter are presented. In the closing of this work, these results are discussed and compared to some of the tests performed. Related subjects for continuation of the project of this type of equipment are also presented. The main focus of this work is the electric machine and its results also provide an orientation to the definition of requirements to the project of electronic converter and control system.
57

Design of a Switched Reluctance Motor for a Light Sport Aircraft Application

Abdollahi, Mohammad Ehsan January 2022 (has links)
With the rapid growth of air travel, concerns about the emissions of greenhouse gas emissions resulting from the air transportation sector are growing. Although the current battery technologies might not be adequate for all-electric regional aircraft, the energy density of the current battery technologies could be adequate to electrify light-sport aircraft used for training and recreation. Due to the nature of the propeller load and noise isolation of the cabin, switched reluctance motors can be an excellent candidate for the propulsion system of electrified light-sport aircraft. The proposed SRM is designed to replace a 70 kW permanent magnet synchronous motor used in the aerospace industry with similar volume constraints and operational requirements. In order to meet the high-power density requirements of this application, a design framework is proposed which includes several layers of the design process. The design objectifies are the average torque, torque ripple, and radial forces by integrating the control and geometry design into the proposed framework. A comprehensive design process is carried out with the proposed framework, and a detailed coil design process is performed. The rotor cut-outs are designed to reduce the weight of the motor. The thermal performance of the motor has been analyzed for the calculated motor losses and the cooling system constraints. / Thesis / Master of Applied Science (MASc)

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