The main focus of the work is the design and construction of static excitation unit of asynchronous generator small hydro power plants with regard to the economic and technical demands. Description of the issue excitation asynchronous generators and possible technical solutions use asynchronous generators in island networks.

Este trabalho apresenta a análise teórica e experimental do gerador assíncrono de dupla alimentação, denominado GEADA ao longo deste trabalho, operando em regime permanente com velocidade não fixa, mas com freqüência da armadura constante. Compreende o escopo do trabalho a análise teórica a partir do circuito equivalente do gerador, a análise teórica e experimental da curva de magnetização do GEADA operando em freqüência do rotor variável, uma proposta de adaptação da curva de capacidade aplicada na operação dos geradores síncronos para o GEADA e a sua análise considerando-o como máquina síncrona a partir dos seus terminais, os ensaios normalizados e complementares necessários para o levantamento dos parâmetros para este circuito equivalente e ensaios do GEADA operando com carga para verificação de seu desempenho Os resultados obtidos permitem um melhor entendimento desse sistema de geração, de suas condições de operação e utilização em sistemas de geração de velocidade não fixa como, por exemplo, sistemas eólicos e hidrelétricos. / The study presents the theoretical and experimental analysis of the double fed asynchronous generator, called GEADA, operating in steady state with non-fixed speed but with constant armature frequency. It comprehends the theoretical analysis based on the equivalent circuit of this generator, the theoretical and experimental analysis of the curve of magnetization of the GEADA operating with variable rotor frequency. A proposal of adaptation of the capability curve applied in the operation of the synchronous generators for the GEADA is also presented, its analysis considering it as a synchronous machine from its terminals, the standard and complementary tests necessary for the calculation of the parameters for the equivalent circuit and the tests with the GEADA operating under on-load conditions to verify its performance. The achieved results allow a better understanding of this generation system, its operational conditions and applicability to the power generation systems based on variable speed, such as wind and hydroelectric power plants.

Este trabalho apresenta a análise teórica e experimental do gerador assíncrono de dupla alimentação, denominado GEADA ao longo deste trabalho, operando em regime permanente com velocidade não fixa, mas com freqüência da armadura constante. Compreende o escopo do trabalho a análise teórica a partir do circuito equivalente do gerador, a análise teórica e experimental da curva de magnetização do GEADA operando em freqüência do rotor variável, uma proposta de adaptação da curva de capacidade aplicada na operação dos geradores síncronos para o GEADA e a sua análise considerando-o como máquina síncrona a partir dos seus terminais, os ensaios normalizados e complementares necessários para o levantamento dos parâmetros para este circuito equivalente e ensaios do GEADA operando com carga para verificação de seu desempenho Os resultados obtidos permitem um melhor entendimento desse sistema de geração, de suas condições de operação e utilização em sistemas de geração de velocidade não fixa como, por exemplo, sistemas eólicos e hidrelétricos. / The study presents the theoretical and experimental analysis of the double fed asynchronous generator, called GEADA, operating in steady state with non-fixed speed but with constant armature frequency. It comprehends the theoretical analysis based on the equivalent circuit of this generator, the theoretical and experimental analysis of the curve of magnetization of the GEADA operating with variable rotor frequency. A proposal of adaptation of the capability curve applied in the operation of the synchronous generators for the GEADA is also presented, its analysis considering it as a synchronous machine from its terminals, the standard and complementary tests necessary for the calculation of the parameters for the equivalent circuit and the tests with the GEADA operating under on-load conditions to verify its performance. The achieved results allow a better understanding of this generation system, its operational conditions and applicability to the power generation systems based on variable speed, such as wind and hydroelectric power plants.

Este trabalho apresenta a análise teórica e experimental do gerador assíncrono de dupla alimentação, denominado GEADA ao longo deste trabalho, operando em regime permanente com velocidade não fixa, mas com freqüência da armadura constante. Compreende o escopo do trabalho a análise teórica a partir do circuito equivalente do gerador, a análise teórica e experimental da curva de magnetização do GEADA operando em freqüência do rotor variável, uma proposta de adaptação da curva de capacidade aplicada na operação dos geradores síncronos para o GEADA e a sua análise considerando-o como máquina síncrona a partir dos seus terminais, os ensaios normalizados e complementares necessários para o levantamento dos parâmetros para este circuito equivalente e ensaios do GEADA operando com carga para verificação de seu desempenho Os resultados obtidos permitem um melhor entendimento desse sistema de geração, de suas condições de operação e utilização em sistemas de geração de velocidade não fixa como, por exemplo, sistemas eólicos e hidrelétricos. / The study presents the theoretical and experimental analysis of the double fed asynchronous generator, called GEADA, operating in steady state with non-fixed speed but with constant armature frequency. It comprehends the theoretical analysis based on the equivalent circuit of this generator, the theoretical and experimental analysis of the curve of magnetization of the GEADA operating with variable rotor frequency. A proposal of adaptation of the capability curve applied in the operation of the synchronous generators for the GEADA is also presented, its analysis considering it as a synchronous machine from its terminals, the standard and complementary tests necessary for the calculation of the parameters for the equivalent circuit and the tests with the GEADA operating under on-load conditions to verify its performance. The achieved results allow a better understanding of this generation system, its operational conditions and applicability to the power generation systems based on variable speed, such as wind and hydroelectric power plants.

Este trabalho tem como objetivo investigar a máquina de indução funcionando como gerador. Para isso, são pesquisadas as normas e requisitos para operação interligada à rede de distribuição até o presente momento. Os parâmetros elétricos referente ao circuito equivalente monofásico da máquina de indução de 15 kW, pertencente a um grupo gerador a biogás, são levantados, realizando-se uma caracterização e modelamento destes parâmetros. Os resultados teóricos obtidos têm o intuito de predizer o comportamento das grandezas elétricas quando o grupo gerador operar em condições nominais, interligado a rede de distribuição. Também, estes resultados teóricos são comparados com valores medidos em ensaios de campo utilizando um motor CC de 10 kW como máquina primária. / This study aims at investigate the induction machine operating as a generator. For this, we researched the standards and requirements for the operation connected to the distribution grid to the present date. The electrical parameters concerning the equivalent circuit per phase of a 15 kW induction machine are raised, this machine is part of a small biogas plant. An appropriate characterization and modeling of these parameters are realized and the theoretical results obtained are intended to predict the behavior of electrical units when the generator is placed at nominal operation. Also, these theoretical results are compared with experimental measurements using a 10 kW DC motor as primary mover.

Este trabalho tem como objetivo investigar a máquina de indução funcionando como gerador. Para isso, são pesquisadas as normas e requisitos para operação interligada à rede de distribuição até o presente momento. Os parâmetros elétricos referente ao circuito equivalente monofásico da máquina de indução de 15 kW, pertencente a um grupo gerador a biogás, são levantados, realizando-se uma caracterização e modelamento destes parâmetros. Os resultados teóricos obtidos têm o intuito de predizer o comportamento das grandezas elétricas quando o grupo gerador operar em condições nominais, interligado a rede de distribuição. Também, estes resultados teóricos são comparados com valores medidos em ensaios de campo utilizando um motor CC de 10 kW como máquina primária. / This study aims at investigate the induction machine operating as a generator. For this, we researched the standards and requirements for the operation connected to the distribution grid to the present date. The electrical parameters concerning the equivalent circuit per phase of a 15 kW induction machine are raised, this machine is part of a small biogas plant. An appropriate characterization and modeling of these parameters are realized and the theoretical results obtained are intended to predict the behavior of electrical units when the generator is placed at nominal operation. Also, these theoretical results are compared with experimental measurements using a 10 kW DC motor as primary mover.

Este trabalho tem como objetivo investigar a máquina de indução funcionando como gerador. Para isso, são pesquisadas as normas e requisitos para operação interligada à rede de distribuição até o presente momento. Os parâmetros elétricos referente ao circuito equivalente monofásico da máquina de indução de 15 kW, pertencente a um grupo gerador a biogás, são levantados, realizando-se uma caracterização e modelamento destes parâmetros. Os resultados teóricos obtidos têm o intuito de predizer o comportamento das grandezas elétricas quando o grupo gerador operar em condições nominais, interligado a rede de distribuição. Também, estes resultados teóricos são comparados com valores medidos em ensaios de campo utilizando um motor CC de 10 kW como máquina primária. / This study aims at investigate the induction machine operating as a generator. For this, we researched the standards and requirements for the operation connected to the distribution grid to the present date. The electrical parameters concerning the equivalent circuit per phase of a 15 kW induction machine are raised, this machine is part of a small biogas plant. An appropriate characterization and modeling of these parameters are realized and the theoretical results obtained are intended to predict the behavior of electrical units when the generator is placed at nominal operation. Also, these theoretical results are compared with experimental measurements using a 10 kW DC motor as primary mover.

Floating offshore wind turbines show great potential within the energy industry, especially for deeper waters where traditional fixed-bottom turbines cannot be used. Offshore locations also offer stronger and more stable winds compared to onshore locations. The study explores the impact of the secondary machine efficiency on the electricity production in a Counter Rotating Axis Floating Tilting (CRAFT) wind turbine. The counter-rotating design holds promise for achieving high overall system efficiency.  MATLAB simulations show that it is possible to maintain a lower secondary machine efficiency without compromising stability. Reviewing two control systems confirms that using a robust control algorithm with optimized TSR ensures system stability in both high and low winds. A decrease in secondary electric machine efficiency from 97% to 93% resulted in a 0.03% reduction in annually generated electricity, whereas a similar decrease in primary electric generator efficiency led to a 1% reduction instead. Decreasing the secondary machine efficiency further to 83% resulted in a 0.1% reduction in annual generated electricity. Thus, the secondary machine's efficiency is shown to be less critical for the electricity production than the primary generator’s efficiency.  Choosing an asynchronous over a synchronous option as the secondary machine is economically advantageous since its lower efficiency of 83% instead of 97% does not significantly affect the electricity production. Moreover, the lower magnet cost for the asynchronous machines positively impacts economic metrics like LCoE, NPVI and payback period, making the asynchronous generator a more favourable economic choice. Further research areas to obtain higher accuracy include integrating differences in maintenance costs and conducting a more in-depth assessment of the investment costs associated with the two types of generators. Additionally, considering airflow losses around turbine blades and airflow interaction amongst the turbines could further enhance the model accuracy.

La capacité des systèmes conventionnels de production d'énergie éolienne et marémotrice à fournir au réseau une énergie fiable et stable à tout moment est un nouveau défi en raison des fluctuations météorologiques, qui ont un impact significatif et direct sur la production d'énergie. C'est pourquoi l'hybridation des systèmes de production d'énergie éolienne et hydrolienne ont été étudiées pour améliorer l'intégration des énergies éolienne et marémotrice sur le réseau électrique.Cette étude nous a amené à développer des contributions liées à deux axes principaux :Le premier axe est focalisé sur un nouveau concept d'hybridation de deux sources énergétiques différentes en termes de propriétés physiques, l’éolien et l’hydrolienne à axe horizontal, basé sur un couplage électromécanique de ces deux systèmes. Les deux ressources sont l’énergie éolienne et l’énergie des courants marins. Le concept est développé en utilisant les similitudes fonctionnelles des turbines et les similarités en conversion d’énergie de leurs chaînes énergétiques. Pour appliquer ce concept en premier lieu, les paramètres de la génératrice asynchrone à double alimentation installée dans l’émulateur du GREAH sont identifiés. Ensuite, la chaîne de conversion de puissance est modélisée mathématiquement et simulée dans un environnement MATLAB / SIMULINK. Nous avons développé deux stratégies de commande.Une stratégie à vitesse fixe appelé "Contrôle direct de la vitesse", et une stratégie à vitesse variable basée sur la recherche de puissance maximale, dénommée "Contrôle indirecte de vitesse". Enfin, ce concept a été implémenté pratiquement sur l’émulateur en temps réel du laboratoire. Les résultats obtenus ont été analysés et discutés suite à ces travaux.Le deuxième axe est consacré à un concept que l’on appelle «temps accélérée» de simulation ou « temps virtuel ». Par la suite, ce concept a été mis en œuvre sur l’émulateur multi physique disponible au laboratoire GREAH. Ce concept (temps accélérée) est basé sur la réduction des échantillons de profil de vent afin de diminuer le temps de simulation et faciliter la commande en temps réel.Les résultats principaux sont obtenus d’abord dans MATLAB / SIMULINK, puis ont été vérifiés sur l’émulateur en temps réel. L’objectif principal de cette thèse est d’étudier le concept d’hybridation éolienne offshore / éolienne basée sur la flexibilité d’un émulateur multifonctions permettant diverses architectures d’émulation : éoliennes, éoliennes, et systèmes hybrides éoliennes - éoliennes. Nous analysons son impact sur la puissance de sortie du système. Les résultats obtenus sont corrélés aux profils de vitesse du vent et des marées, dans lesquels les propriétés statistiques ayant un impact sur les chaînes énergétiques mondiales pourraient être complémentaires et en particulier en fonction des sites donnés.Contributions principales et perspectives- Développement du concept de couplage électromécanique. Lorsque deux sources d’énergie renouvelables sont « intégrées », on stabilise la fluctuation rapide de la puissance générée, mais sous certaines conditions telles que la présence d’unités de stockage ou d’un système d’embrayage automatique.- Le concept temps accéléréeCette méthode est utilisée pour réduire la taille des données enregistrées du vent ou des courant marins, afin d’accélérer le temps de simulation des unités de production d'énergie avec des résultats raisonnables qui se rapprochent pertinemment des situations réelles.- Etudier et développer le concept de régime d’arbre électrique :Si le couplage électromécanique est difficile à réaliser du point de vue mécanique et que les découplages à arbre unique sont trop fréquents et que les contraintes mécaniques sont élevées, on peut étudier le régime de l'arbre électrique avec deux machines à induction DFIG. Le système peut fonctionner en mode synchrone avec des structures et configurations spécifiques. / The ability of conventional wind and tidal generation systems to provide the grid with reliable and stable power at all times is a new challenge due to weather fluctuations, which have a significant and direct impact on energy production. This is why the hybridization of wind and tidal power generation systems has been studied to improve the integration of wind and tidal power into the electricity grid.This study led us to develop contributions related to two main axes:The first axis is focused on a new concept of hybridization of two different energy sources in terms of physical properties, wind and horizontal axis turbines, based on an electromechanical coupling of these two systems. The two resources are wind energy and marine energy. The concept is developed using the functional similarities of turbines and similarities in energy conversion of their energy chains. To apply this concept first, the parameters of the double fed asynchronous generator installed in the GREAH emulator are identified. Then, the power conversion chain is modeled mathematically and simulated in a MATLAB / SIMULINK environment. We have developed two control strategies.A fixed speed strategy called "Direct Speed Control", and a variable speed strategy based on the search for maximum power, called "Indirect Speed Control". Finally, this concept has been implemented practically on the real-time emulator of the laboratory. The results obtained were analyzed and discussed following this work.The second axis is devoted to a concept called "accelerated time" simulation or "virtual time". Subsequently, this concept was implemented on the multi-physics emulator available at the GREAH laboratory. This concept (accelerated time) is based on reducing wind profile samples in order to decrease simulation time and facilitate real-time control.The main results are obtained first in MATLAB / SIMULINK, then verified on the emulator in real time.The main objective of this thesis is to study the concept of offshore wind / tidal turbine hybridization based on the flexibility of a multi-function emulator that allows various emulation architectures: wind turbines, tidal turbines, and hybrid wind - tidal turbines systems. We analyze its impact on the output power of the system; the obtained results are correlated with wind and tidal speed profiles, in which statistical properties impacting global power chains could be complementary and in particular in function of the given sites. Main contributions and perspectives- Development of the concept of electromechanical coupling.When two renewable energy sources are "integrated", the rapid fluctuation of the power generated is stabilized, but under certain conditions such as the presence of storage units or an automatic clutch system.- The accelerated time conceptThis method is used to reduce the size of the recorded wind or sea current data, to speed up the simulation time of the power generation units with reasonable results that are close to actual situations.- Study and develop the concept of electric shaft regime: If the electromechanical coupling is difficult to achieve from the mechanical point of view and the single shaft decouples are too frequent so high mechanical stress, one can study the electric shaft regime with two DFIG induction machines.There is a regime in which the ratios between the speeds of the different machines are rigorously constant. The system can operate in synchronous mode with specific structures and configurations.

The thesis deal with design of coaxial high-speed gear box for small-scale turboshaft engines. At the beginning a study of problems was performed and for design concept was elected version of single-shaft turbo-engine with electric generator. Kinematic diagram, type of gear design, material and lubrication method was designed. Further was solved proposal of basic gearing parameters, choice of the number of tooth and basic proposal calculations were performed. Was performed check calculation of gearing, calculation of bearings durability and was processed design documentation in required range. Designed gear reducer has two stage with three coutershafts, that are deployed evenly about main axis of reducer. First stage is gear with external gearing, second stage with internal gearing. The thesis may be used as a template for next similar gear reducers design.