Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study had as main objective to perform the modeling and analysis of transient stability of a typical electric power system. The second goal, also important, was to assess the feasibility of using ATP (Alternative Transients Program) as a computer tool for simulation of transient stability. The system focused here is comprised of nine busses with three generators, one hydraulic and the other two with thermal characteristics. All the system machines were equipped with voltage regulators and speed governor in ATP software. The technical issues studied here refer to the analysis of system stability after a disturbance, such as: three-phase short-circuit, load loss and generation outage. The results show that ATP software performs satisfactorily the transient stability analysis. This fact can also be proved by comparing the results obtained from ATP with those from simulations with PSAT (Power System Analysis Toolbox). For this purpose some adjustments were necessary in the graphical results since ATP works in time domain while PSAT program operates in the frequency domain. / Este trabalho teve como principal objetivo realizar a modelagem e a análise da estabilidade transitória de um sistema elétrico de potência típico. O segundo objetivo, também importante, consistiu em avaliar a viabilidade de se utilizar o ATP (Alternative Transients Program) como uma ferramenta computacional para simulação de estabilidade transitória. O sistema aqui enfocado é composto por nove barramentos com três unidades geradoras, uma com característica hidráulica e as outras duas com características térmicas. Todas as máquinas do sistema foram equipadas com reguladores de tensão e velocidade no programa ATP. As questões técnicas estudadas aqui se referem à análise da estabilidade do sistema após uma perturbação, sendo elas: falta trifásica, perda de carga e saída de geração. Os resultados mostram que o software ATP realiza satisfatoriamente a análise de estabilidade transitória. Este fato pode também ser comprovado pela comparação dos resultados obtidos com o ATP com aqueles provenientes de simulações com o PSAT (Power System Analysis Toolbox). Para este propósito foi necessário realizar alguns ajustes nos resultados gráficos já que ATP trabalha no domínio do tempo enquanto que o programa PSAT opera no domínio da frequência, tais como: transformação de alguns gráficos fornecidos pelo ATP em pu. / Mestre em Ciências

Dans le milieu automobile, les règlementations visant à limiter l’émission de particules fines et de gaz à effet de serre sont devenues de plus en plus sévères au cours des dernières années. Cette tendance ne va pas s’inverser et des solutions doivent être trouvées pour améliorer le rendement des moteurs à combustion interne (ICE) qui propulsent la majorité des véhicules de tourisme dans le monde.Une des solutions permettant d’améliorer le rendement thermodynamique de l’ICE est d’utiliser un turbocompresseur. Cet organe de suralimentation permet d’accroître le couple du moteur en augmentant la pression d’air dans les cylindres et par conséquent la quantité de comburant. Le turbocompresseur présente cependant un inconvénient pour l’agrément de conduite. Selon la technologie employée, un temps de latence (turbo lag) plus ou moins important apparait entre le moment ou le conducteur appui sur la pédale d’accélérateur et le moment ou le couple est disponible sur les roues.Pour pallier ce problème, on peut utiliser une machine électrique venant assister le turbocompresseur durant la phase de montée en vitesse. Cette machine peut faire partie d’un système indépendant de compression d’air et placée en amont du turbocompresseur, on parlera alors de turbo assisté électriquement. Cette machine peut aussi être intégrée directement au turbocompresseur, on parlera alors de turbo électrique. Dans les deux cas, le temps de réponse du turbocompresseur est amélioré ce qui impacte directement la dynamique du véhicule et le plaisir de conduite. Dans le cas du turbo électrique, l’intégration de la machine électrique directement sur le turbocompresseur permet son fonctionnement en génératrice en offrant ainsi une amélioration du rendement global de l’ICE.Le sujet de la thèse est la modélisation et la conception des machines électriques haute vitesse pour ces applications. Les principales qualités recherchées pour ces machines seront :-leurs capacités à pouvoir fonctionner à haute vitesse : les vitesses recherchées se situe typiquement entre 70 000 et 150 000 tr/min pour des vitesses périphériques de l’ordre de 150 m/s ;-leurs densités de puissance : on recherche des puissances de 3 à 15 kW pour des machines compactes qui devront être intégrées sous le capot du véhicule ;-des rendements élevés de l’ordre de 95 % ;-une conception adaptée à la production en grande série pour l’automobile.Pour répondre à cette problématique, les travaux suivants ont été entrepris :Dans un premier temps, nous avons modélisé finement les phénomènes électromagnétiques et mécaniques liées aux machines électriques haute vitesse à encoches et aimants permanents positionnés en surface. Pour cela, nous avons développé un modèle de calcul en sous-domaines pour la partie électromagnétique et un modèle multicouches de résistance des matériaux pour le calcul de la tenue du rotor à haute vitesse.Dans un deuxième temps, pour pouvoir explorer des topologies de machines très différentes, nous avons eu recourt aux méthodes de calcul par éléments finis. Nous avons pu identifier et de comparer plusieurs topologies de machines à encoches, sans encoches, à bobinage dentaire ou toroïdal. Cette étude paramétrique a permis de comparer la densité de couple et le rendement de ces machines.Enfin, dans une dernière partie, nous avons traité le cas du prototypage et des mesures de ces machines. Pour cela, sur la base des études réalisées, nous avons prototypé trois machines aux performances prometteuses. La conception mécanique des différentes machines est abordée ainsi que les méthodes de mesures et les difficultés liées aux caractérisations à haute vitesse.Au cours de ce travail de thèse, d’autres aspects ont aussi été abordés tel que la modélisation des pertes du système machine électrique et convertisseur de puissance, la dynamique des rotors ou encore les émissions acoustiques. / In the automotive industry, regulations to limit the emission of greenhouse gases have become more and more severe. This trend is not going to change and solutions must be found to improve the efficiency of internal combustion engines (ICE) that drive the majority of passenger cars in the world.Turbochargers are a clever solution to improve the thermodynamic efficiency of the ICE. This forced induction device increases the air pressure in the cylinders and therefore the engine torque. However, turbochargers have a major disadvantage for the driver experience: a lag time (turbo lag) between the moment when the driver steps on the accelerator and the moment when torque is available.To overcome this problem, an electric machine can be used to assist the turbocharger during the speed up phase. This machine can be a part of an independent system of air compression and placed upstream of the turbocharger or it can be integrated directly into the turbocharger. In both cases, the response time of the turbocharger is greatly reduced which directly impacts the dynamic of the vehicle and the driving pleasure. The integration of the electric machine directly on the turbocharger allows its operation as a generator to improve the overall efficiency of the ICE.The subject of this thesis is the modeling and design of high speed electric machines for these applications. The main requirements are:-High-speed operation: between 70,000 and 150,000 rpm and peripheral speeds around 150 m/s.-Power density: from 3 to 15 kW for compact machines that will have to be integrated under the hood of the vehicle.-High efficiency: around 95 % and above.-A design adapted to mass production for the automotive industry.To cope with this requirements, the following tasks were undertaken:Firstly, we modeled the electromagnetic and mechanical behaviors of high-speed slotted electric machines with surface-mounted permanent magnets. For the electromagnetic part, we developed a subdomain calculation model. For the mechanical part, we worked on a multilayer model to evaluate the rotor strength at high speed.Secondly, we used finite element analysis methods to explore different machine structures. We compared several topologies of slotted and slotless machines, with tooth-coil winding and toroidal winding. This parametric study allowed us to compare the torque density and efficiency of these machines.Finally, we dealt with the case of prototyping and measurements of these machines. Based on the previous studies, we prototyped three machines with promising performances. The mechanical design of the different machines is discussed as well as the measurement methods and the difficulties associated with high speed characterization.During this thesis work, other aspects were also discussed such as the losses in power converters driving high-speed electric machines, rotor dynamics and acoustic emissions.

Les travaux de cette thèse portent sur une nouvelle structure de machine à double excitation (MSDE) pour l'application des véhicules hybrides et électriques. Ce type de machine, ayant deux sources d'excitation, bénéficie un degré de liberté supplémentaire et un contrôle facile sur le flux. Grâce à ce degré de liberté, la machine peut être dimensionnée de manière que son meilleur rendement coïncide avec la zone de fonctionnement la plus sollicitée de la machine. Cette nouvelle structure a fait l'objet principal de ce mémoire. Le fonctionnement de la MSDE est présenté dans les deux premiers chapitres. La machine est dimensionnée suivant un cahier des charges pour véhicule hybride. La validation expérimentale a confirmé le bon fonctionnement de la structure et montré son intérêt. Une autre problématique dans le dimensionnement de la machine est l'aspect thermique car les machines sont devenues de plus en plus compactes et puissantes. Une estimation correcte des pertes est indispensable pour évaluer correctement les performances de la machine. C'est la raison pour laquelle on a décidé de consacrer une partie de cette thèse à la modélisation des pertes fer, dont l'estimation n'est pas évidente. / The PhD work deals with a new structure of hybrid excited synchronous machine (MSDE) for the application of hybrid and electric vehicles. This kind of machine, with two excitation sources, benefits an additional degree of freedom and an easy control of flux. Due to this degree of freedom, the machine can be designed in the way that its best efficiency coincide with the most solicited operating zone. This new machine structure is the main subject of this study. The principle of this MSDE is presented in the first two chapters. The machine is then designed according to the specifications for an hybrid vehicle. The experimental validation has confirmed the proper functioning of the structure and shown its interest. Another important subject in the machine sizing is the thermal aspect because our machines are becoming more and more compact and powerful. A correct estimation of the iron loss is essential for evaluating correctly the machine performances. That's why we have decided to dedicate a part of this study to the modeling of iron loss, of which the estimation is not evident.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work aims to analyze the dynamic performance of a synchronous generator and its controls in a distributed generation system, as well as evaluate the impacts of its operation when connected to the distribution grid, using for this task the ATPDraw interface/tool of software ATP. Within this context, it is firstly necessary to obtain suitable models to represent the synchronous machine control systems (voltage regulator, speed governor and stabilizer system) in ATPDraw. Furthermore, for stability analysis, it is developed a mathematical technique to calculate the machine power angle which is represented in ATPDraw by a device (icon). The adjustments of voltage and speed control system parameters are performed by some adopted procedures which are verified using two electric systems: the first one with a synchronous generator connected to the distribution grid; and the second with three distinct generators forming a multimachine system. In these systems some disturbances are applied such as load shedding and short-circuit to accomplish the studies. Finally, with the previous results, it is carried out some dynamic performance studies of a synchronous generator of an independent producer connected to a distribution grid so as to assess aspects of power quality (voltage magnitude), stability and to evaluate the influence of machine controls during the system response for a given load shedding. / Este trabalho tem como objetivo analisar o desempenho dinâmico de um gerador síncrono e seus controles, num sistema de geração distribuída, assim como avaliar os impactos causados por este quando da sua operação conectado às redes de distribuição, utilizando a interface ATPDraw do software ATP. Neste contexto, é primeiramente necessário obter modelos adequados para representar os sistemas de controle da máquina síncrona (regulador de tensão e regulador de velocidade e estabilizador do sistema) no ATPDraw. Além disso, para análise de estabilidade é desenvolvido uma técnica matemática para o cálculo do ângulo de potência da máquina a qual é representada no ATPDraw por um dispositivo (ícone). Para ajustar os parâmetros dos sistemas de controle de tensão e de velocidade são apresentados alguns procedimentos adotados, sendo estes verificados por meio de dois sistemas elétricos: o primeiro com um gerador síncrono conectado a uma rede de distribuição; e o segundo composto por três geradores distintos formando um sistema multimáquinas. Nesses sistemas são aplicados distúrbios do tipo rejeição de carga e curto-circuito para realização dos estudos. Finalmente, com os resultados obtidos anteriormente, são realizados estudos do desempenho dinâmico de um gerador síncrono de um produtor independente, conectado a rede de distribuição, para avaliar aspectos de qualidade de energia (magnitude de tensão), de estabilidade e verificar as influências dos controles da máquina durante a resposta do sistema para uma dada rejeição de carga. / Mestre em Ciências

Este trabalho apresenta uma estratégia de controle coordenado para potência reativa e tensão terminal de um grupo moto gerador (GMG) para uso em um sistema de geração distribuída (GD). A partir da construção de uma superfície fuzzy, baseada no comportamento do erro e da derivada do erro de uma malha de controle, foi realizada a sintonia de controladores fuzzy PD+I para potências ativa e reativa e tensão terminal. O controlador coordenado fuzzy PD+I ajusta automaticamente a tensão nos terminais da máquina e a potência reativa fornecidas à rede de distribuição. A estratégia coordenada é dada através de um parâmetro que regula a malha de potência reativa a partir do erro de tensão terminal, priorizando o ajuste da tensão e ponderando a malha de controle de potência reativa. Para avaliar o desempenho do sistema de controle, a GD é conectada a uma rede de distribuição e submetida a eventos como entrada e saída de cargas locais. O conjunto de cargas locais é composto por um motor de indução, uma carga RLC e um retificador trifásico não controlado. Sete cenários foram simulados para avaliar a estratégia de controle em diferentes regimes de operação do GMG. Resultados para tensão terminal, fator de potência e fluxo de potências entre o sistema, as cargas e a rede, ilustram a eficiência da estratégia de controle apresentada. A estratégia de controle coordenado para potência reativa e tensão terminal se mostrou capaz de melhorar os índices de fator de potência controlando o fluxo de potência do barramento em que a GD estava conectada, sem prejudicar a tensão terminal do gerador, mantendo a GD em limites seguros de operação. / This work presents a coordinated control strategy to terminal voltage and reactive power for a diesel generation set used as a distributed gerenation system (DG). From desired control actions, a fuzzy surface was designed for fuzzy PD+I controllers. Fuzzy PD+I controllers automatically adjust the terminal voltage and the reactive power delivered to the grid. The coordinated control strategy weighs the control action for the reactive power through a variable parameter, prioritizing the terminal voltage adjustment. To illustrate the system control performance, the DG is connected to a grid dynamic model and the system is subjected to connection and disconnection of loads at the local bus. The local loads set was composed of an induction machine, a RLC load and an uncontrolled three-phase rectifier. Seven scenarios were simulated to evaluate the control strategy in different DG regime of operation. Results for terminal voltage, power factor and reactive power among the DG, the local loads and the grid, illustrates the control strategy efficiency improved the power factor by regulating the reactive power injected at the bus, maintaining the DG terminal voltage in safe operation limits.

Les machines électriques synchrones à aimants permanents sont susceptibles de rencontrer un disfonctionnement suite à un échauffement non maîtrisé. L’objectif de cette étude est de développer un modèle thermique générique et prédictif pouvant simuler diverses situations d’intérêts: régime permanent, régime transitoire, mode dégradé, entrefer immergé, haute vitesse. Pour cela, la méthode nodale est utilisée pour développer le modèle thermique générique. En parallèle, un banc d’essai et un prototype sont conçus pour valider le modèle. L’étude de sensibilité des résultats du modèle à certains paramètres montrent que certains coefficients de convection, certaines conductances de contact et la conductivité thermique radiale du bobinage ont une influence considérable sur les résultats du modèle. Cependant ces paramètres sont mal connus, car ils sont issus des formules empiriques ou des abaques. Grâce au prototype et au modèle développé, ces paramètres sont identifiés. Trois méthodes d’identification sont testées pour aboutir à une stratégie d’identification: les algorithmes génétiques, la méthode de Gauss-Newton et la méthode de Levenberg-Marquardt. Plusieurs essais sont effectués sur le prototype instrumenté. La mesure des températures à des lieux précis du prototype permet d’identifier les paramètres mal connus et de valider le modèle. / Permanent magnet synchronous machines are likely to break down due to poorly controlled heating. The goal of this study was to develop a generic and predictive thermal model to calculate the temperature of machines during the design phase simulating temperatures at various states. These states include: steady state, transient state, fault mode, axial circulating of a cooling fluid in the air-gap and high speed. The lumped parameter method was used to develop this generic thermal model. Meanwhile, a test bench and a prototype instrumented with thermocouples were manufactured to validate the model at the same time. Sensitivity studies of the results of the model to some parameters demonstrated that some convective coefficients, contact conductances and the thermal conductivity of the winding in the radial direction influenced the model. However, these parameters are poorly known, because empirical formulas or abacus are used to calculate them. Using, the prototype and the developed model, these parameters were identified. Three methods of identification were tested in order to find a strategy for the identification: the genetic algorithms method, the Gauss-Newton method and the Levenberg-Marquardt method. Many tests were done on the prototype. The measure of the temperatures on the specific place allows to identify these parameters and to validate the model.

This thesis proposes control schemes and converter configurations for high power wound field synchronous motor (WFSM) drives. The model for a salient pole WFSM in any general rotating reference frame is developed which can be used to derive models along known rotor (dq) and stator flux (MT) reference frames. Based on these models, the principle of sensor-less stator flux oriented field-oriented control (FOC) for salient pole WFSM is developed. So far in the literature, control of cylindrical rotor machine only has been addressed and the effects of saliency have generally been neglected. The performance of the proposed sensor-less FOC has been demonstrated by experimentally operating a 15.8 HP salient pole WFSM using a three-level IGBT based voltage source inverter (VSI). The principle of FOC has been later extended to the control of current source load commutated inverter (LCI) fed salient pole WFSM drives, where the drawbacks present in conventional self-control method such as rigorous off-line calculation for generation of look up tables, coupling between flux and torque control etc. are eliminated. This thesis also proposes the combination of a VSI with the LCI power circuit to overcome the different disadvantages that are present in the existing LCI topology. Firstly, a novel starting scheme is proposed, where the LCI fed WFSM is started with the aid of a low power auxiliary VSI converter in a smooth manner with sinusoidal motor currents and voltages. This overcomes the difficulties of the present complex dc link current pulsing technique that has drawbacks such as pulsating torque, long starting time etc. In a second mode of operation, it is shown that the VSI can be connected to the existing LCI fed WFSM drive as a harmonic compensator in On-The-Fly mode; this will make the terminal stator current and voltage sinusoidal apart from cancellation of torque pulsations thus improving the drive performance. The above two schemes have potential as retrofit for existing drives. It is possible to combine both the advantages, mentioned above, by permanently connecting the VSI with the LCI power circuit to feed the WFSM. This proposed hybrid LCI/VSI drive can be regarded as a universal solution for high power synchronous motor drives at all power and speed ranges.

Le travail présenté dans cette thèse porte sur l'étude du dimensionnement d'une chaine de conversion électrique en entrainement direct d'un système direct de récupération de l'énergie des vagues (searev). Cette chaine de conversion est composée d'une génératrice synchrone à aimants permanents solidaire d'un volant pendulaire, d'un convertisseur électronique composé de deux ponts triphasés à modulation de largeur d'impulsion, l'un contrôlant la génératrice, l'autre permettant d'injecter l'énergie électrique au réseau. En complément, un système de stockage de l'énergie (batterie de supercondensateurs) est destiné au lissage de la puissance produite. Le dimensionnement de tous ces éléments constitutifs nécessite une approche d'optimisation sur cycle, dans un contexte de fort couplage multi-physique notamment entre les parties hydrodynamique et électromécanique. Dans un premier temps, l'ensemble génératrice-convertisseur, dont le rôle est d'amortir le mouvement d'un volant pendulaire interne, est optimisé en vue de minimiser le coût de production de l'énergie (coût du kWh sur la durée d'usage). Cette optimisation sur cycle est réalisée en couplage fort avec le système houlogénérateur grâce à la prise en compte conjointe de variables d'optimisation relatives à l'ensemble convertisseur-machine mais aussi à la loi d'amortissement du volant pendulaire. L'intégration d'une stratégie de défluxage, intéressante pour assurer un fonctionnement en écrêtage de la puissance, permet, dès l'étape de dimensionnement, de traiter l'interaction convertisseur-machine. Dans un second temps, la capacité énergétique du système de stockage de l'énergie fait l'objet d'une optimisation en vue de la minimisation de son coût économique sur cycle de vie. Pour ce faire, nous définissons des critères de qualité de l'énergie injectée au réseau, dont un lié au flicker, et nous comparons des stratégies de gestion de l'état de charge tout en tenant compte du vieillissement en cyclage des supercondensateurs dû à la tension et à leur température. Dans un troisième temps, à partir de données d'états de mer sur une année entière, nous proposons des dimensionnements de chaines de conversion électrique qui présentent les meilleurs compromis en termes d'énergie totale récupérée et de coût d'investissement. / The work presented in this thesis sets forth the study of the sizing of a direct-drive electrical conversion chain for a direct wave energy converter (SEAREV). This electrical chain is made up of a permanent magnet synchronous generator attached to a pendular wheel and a power-electronic converter made up of two three-phase pulse width modulation bridge, one controlling the generator, the other allowing injecting electrical energy into the grid. In addition, an energy storage system (bank of supercapacitors) is intended to smooth the power output. The sizing of all these components needs an operating cycle optimization approach, in a system context with strong multi-physics coupling, more particularly between hydrodynamical and electromechanical parts. At first, the generator-converter set, whose role is to damp the pendular movement of an internal wheel, is optimized with a view to minimize the cost of energy (kWh production cost). This optimization, based on torque-speed operating profiles, is carried out considering a strong coupling with the wave energy converter thanks to the consideration as design variables, some relatives to the generator-converter sizing but also some relatives to the damping law of the pendular wheel. In addition, the consideration of a flux-weakening strategy, interesting to ensure a constant power operation (levelling), allows, as soon as the sizing step, to deal with the generator-converter interaction. In a second step, the rated energy capacity of the energy storage system is being optimized with a view of the minimization of its economical life-cycle cost. To do this, we define quality criteria of the power output, including one related to the flicker, and we compare three energy managment rules while taking into account the power cycling aging of the supercapacitors due to the voltage and their temperature. In a third step, from yearly sea-states data, we provide sizings of the direct-drive electrical conversion chain that are the best trades-offs in terms of total electrical produced energy and economical investment cost.

Tato práce se zabývá synchronním motorem s permanentními magnety na rotoru (PMSM), jeho modelováním a návrhu regulační struktury. V práci jsou uvedeny způsoby a výhody použití permanentních magnetů v elektrických motorech. Dále se práce zabývá transformací třífázové soustavy do dq0. Pomocí Parkovy transformace jsou v práci odvozeny rovnice stroje v dq0 souřadnicovém systému a vytvořeny náhradní schémata stroje v dq osách. Rovnice i schémata zahrnují jak ztráty v mědi, tak ztráty v železe. Náhradní schémata jsou popsány elektrickými a mechanickými rovnicemi a následně překresleny do grafické podoby v programu Matlab Simulink. Vytvořeny jsou dva modely PMSM, jeden s uvažováním ztrát v železe a druhý bez těchto ztrát. Pro oba dva modely je zde popsán postup návrhu regulátorů proudu a otáček. Pro model, u kterého jsou uvažovány ztráty v železe je navíc použito více druhů řídicích strategií a tyto strategie jsou mezi sebou navzájem porovnány.

Táto práca pojednáva o problematike vytvárania a simulácie reluktančnej sieti synchrónneho stroja s V tvarovanými permanentnými magnetmi v programe PSpice. Na začiatku sa oboznámime s konštrukciou a parametrami stroja a potom vyvodíme základné rovnice na výpočet každého prvku siete. Vypočítame každý prvok tohto stroja a potom vytvoríme túto sieť v PSpice. Na začiatku je simulovaná sieť statická a všetky magnetické odpory sú lineárne. Neskôr nahradíme lineárne odpory reprezentujúce plechy nelineárnymi a počítame s precovnou teplotou permanentných magnetov. Potom porovnáme naše výsledky s FEM metódou počítanými hodnotami a vypočítame indukované napätie v jednej cievke stroja. Na záver vypočítame výkonovú a momentovú charakteristiku stroja.