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In this thesis, a Matlab/Simulink®-based simulation tool for marine current turbines has been proposed. A multiphysics approach has been adopted to model the whole system, including the resource, the rotor, the gearbox, and the generator. The developed tool can evaluate a marine current turbine performances and dynamic loads over different operating conditions. Moreover, it should be used to quantify the potential for generating electricity from various sites and therefore evaluate their cost-effectiveness. Currently, the marine current turbine simulator incorporates all types of horizontal-axis turbines. Moreover, it includes two different electrical topologies, one based on the doubly-fed induction generator and the other on the permanent magnet synchronous one. For these two technologies, two types of speed control strategies have been proposed. The first one suggests the use of well-known PI controllers. While, the second one proposes a nonlinear control approach based on the so-called high-order sliding mode that should handle torque oscillation smoothing and robustness against resource turbulences and electric grid disturbances. The various components of the simulator have been tested and experimentally proven in terms of models and speed control performances. The obtained results were consistent and very promising. ; Les travaux développés durant cette thèse, ont permis la mise au point d'un simulateur qui permet de prévoir le comportement d'une hydrolienne dans son environnement. A cet effet, une approche multiphysique a été adoptée pour la modélisation de l'ensemble de la chaîne de conversion d'énergie. L'environnement de simulation ainsi développé peut également être utilisé pour le dimensionnement et l'évaluation de la rentabilité d'installations hydroliennes. A l'heure actuelle, l'outil développé permet de simuler tous les types de turbines à axe horizontal. De plus, il permet de choisir entre deux topologies électriques différentes ; une basée sur la génératrice asynchrone à double alimentation et ...

This work proposes a controller design that integrates an Equivalent Consumption Minimization Strategy framework and a quasi-LPV framework. The proposed scheme allows exploiting the characteristics of both frameworks. Also, a proof of the input-state-stability (ISS) of the closed-loop is presented, expressed as linearmatrix-inequality conditions. Simulation results are provided to illustrate the applicability of our approach in a hybrid powertrain setting as encountered in the maritime industry. ; Transport Engineering and Logistics

In this thesis, a Matlab/Simulink®-based simulation tool for marine current turbines has been proposed. A multiphysics approach has been adopted to model the whole system, including the resource, the rotor, the gearbox, and the generator. The developed tool can evaluate a marine current turbine performances and dynamic loads over different operating conditions. Moreover, it should be used to quantify the potential for generating electricity from various sites and therefore evaluate their cost-effectiveness. Currently, the marine current turbine simulator incorporates all types of horizontal-axis turbines. Moreover, it includes two different electrical topologies, one based on the doubly-fed induction generator and the other on the permanent magnet synchronous one. For these two technologies, two types of speed control strategies have been proposed. The first one suggests the use of well-known PI controllers. While, the second one proposes a nonlinear control approach based on the so-called high-order sliding mode that should handle torque oscillation smoothing and robustness against resource turbulences and electric grid disturbances. The various components of the simulator have been tested and experimentally proven in terms of models and speed control performances. The obtained results were consistent and very promising. Les travaux développés durant cette thèse, ont permis la mise au point d'un simulateur qui permet de prévoir le comportement d'une hydrolienne dans son environnement. A cet effet, une approche multiphysique a été adoptée pour la modélisation de l'ensemble de la chaîne de conversion d'énergie. L'environnement de simulation ainsi développé peut également être utilisé pour le dimensionnement et l'évaluation de la rentabilité d'installations hydroliennes. A l'heure actuelle, l'outil développé permet de simuler tous les types de turbines à axe horizontal. De plus, il permet de choisir entre deux topologies électriques différentes ; une basée sur la génératrice asynchrone à double alimentation et une sur la génératrice synchrone à aimants permanents. Pour ces deux technologies, deux types de commande en vitesse ont été proposés. La première stratégie consacre l'utilisation des régulateurs linéaires PI. La deuxième, quant à elle, propose une commande non linéaire dite modes glissants d'ordre supérieur. Les différents composants du simulateur ont été testés et éprouvés expérimentalement en termes de modèles et en termes de performances de régulations de vitesse. Les développements présentés dans ce mémoire restent cependant perfectibles ouvrant ainsi la voie à d'intéressantes perspectives.

The implantation and deployment of marine current turbine arrays depend on the understanding of their interactions. Based on a priori suggestions about the layout of marine energy converter arrays, we propose to highlight interactions effects between two horizontal axis marine current turbines, in open water. experimental trials were run in IFREMER’s wave and current flume tank in Boulogne-sur-Mer (France), on marine current turbine models. Our study focuses on setups were the second turbine is axially aligned, at different distances, in the wake of the first one. Interaction effects are pointed out both in terms of performance and wake characterisation by means of a comparison with results on a single turbine. This study shows that the downstream turbine behaviour is deeply influenced by the upstream turbine wake.We also present numerical results obtained on a single turbine from our tri-dimensional numerical software, which is developed at the Laboratoire Ondes et Milieux Complexes,Le Havre (France). Those numerical results are validated by the comparison with the experiments, which allows us to foresee the modelling of several turbines and thus of turbine farms with a more complex layout.

This dataset gathers data used to infer the trophic structure and functioning of fish assemblages in the Eastern English Channel, the Bay of Biscay and the Gulf of Lions : - Biomass data, resulting from accoustic monitoring for pelagic species, or bottom trawling for demersal species, after extrapolation based on stratification scheme - Individual C and N isotopic ratios, length and mass, for all individuals considered - Individual energetic density values

Ce rapport de suivi environnemental a ��t�� men�� par l'��quipe du site d'essais SEM-REV afin de comprendre, caract��riser et mesurer les potentiels impacts environnementaux de l�����olienne flottante, FLOATGEN. Ce d��monstrateur flottant de 2 MW dont le flotteur a ��t�� d��velopp�� par la soci��t�� BW IDEOL est install�� en mer et produit de l�����lectricit�� depuis 2018. Ce suivi couvre toutes les ��tapes de ces 3 ann��es de test en conditions r��elles, de l�����tat initial du site �� la phase d���installation des syst��mes d���ancrage, au remorquage de l�����olienne sur site et �� son raccordement au r��seau ��lectrique puis pendant son exploitation et lors des op��rations de maintenance. L�����tude concerne plusieurs domaines de la physique (acoustique sous-marine, champs ��lectromagn��tique, temp��rature) �� la biologie (mammif��res marins, communaut��s benthiques, avifaune, ���) en passant par une composante sociale avec une analyse paysag��re. �� ce jour, aucun effet ou impact fort n���a ��t�� relev�� sur l���environnement marin parmi l���ensemble des domaines ��tudi��s. De plus, aucun incident environnemental ni aucune pollution n���a ��t�� engendr��, que ce soit dans les phases de travaux, d���exploitation ou de maintenance du d��monstrateur. Les essais du d��monstrateur FLOATGEN se poursuivent jusqu����� l���automne 2023. Une fois les tests termin��s, le d��monstrateur sera d��mantel��. Le rapport de suivi environnemental sera mis �� jour p��riodiquement pour couvrir l���ensemble de la phase de tests puis le d��mant��lement.

The maximal power that is absorbed by a wave energy converter can be estimated from the far-field behavior of the waves that are radiated by the device. For realistic estimates, constraints must be used to enforce restrictions on the set of admissible motions when deriving the maximal absorption width. This work is dedicated to the numerical computation of the maximal absorption width under constraints for devices with several non-trivial degrees of freedom. In particular, the method is applied to a model of SBM Offshore’s S3 wave energy converter, a bulging horizontal cylinder. The results are compared with a more classical approach, which consists of computing the linear dynamic response of the wave energy converter interacting with the waves. The far-field maximal absorption width can be seen as an upper bound to evaluate what would be the power captured by a perfect control strategy. The method also shows that the absorption width of the S3 wave energy converter is larger for wavelengths that are smaller than the device length. In practice, this means that S3 wave energy converters will be longer than the maximal wavelength to be captured on the targeted production site.

Due to the ever-increasing electricity demand, along with the need to reduce the dependence on fossil or nuclear resources, a growing amount of renewable energy is integrated in the energy mix of many countries. However, the cost-effective integration of wave energy remains difficult as its cost is still not competitive compared with other energy sources. This paper deals with the energy production management of a simulated wave energy converter farm based on point absorbers that could be installed in the vicinity of the SEM-REV site. The approach considers the electrothermal behaviour of the export cable in combination with techno-economic aspects. The method can be used to extend the power export capability of a test site at no cost, which could be very interesting to install more marine renewable energy (MRE) converters and/or of greater rated power. Our study shows that exploiting the thermal inertia of a wave farm submarine export cable, while also considering techno-economic aspects, may lead to an increase of 18% in the annual energy production without modifying this cable.

International audience Electrical power generated from sustainable energies, such as marine renewable energy (MRE), is a key to the future. However, the cost of production still remains higher than for conventional energy sources. This paper describes a preliminary techno-economic study about the energy production management of a modelled point absorber-based wave energy converters (WEC) farm that could be installed in the vicinity of the SEM-REV site, i.e. the French multi-technology open sea testing site. The approach presented in this paper relies on a wave to wire model of the farm coupled with an electro-thermal analysis of the SEM-REV export cable, and a simple WEC economic cost model. The proposed methodology, developed under Matlab-Simulink ® , can be extended to other WEC types and more sophisticated models and control strategies. That makes it an interesting tool to determine the optimum number of WECs which can be added in an existing farm, as it depends highly on the sea climate of the future site, and in particular on its temporal characteristics. It is demonstrated in this paper that it could be feasible, from a techno-economic perspective, to increase the rated power of an existing WEC farm without requiring expensive grid reinforcements. This could be achieved by better exploiting the electro-thermal flexibility of its existing electric infrastructure.