Electromagnetic coupling phenomena between overhead power transmission lines and other nearby structures are inevitable, especially in densely populated areas. The undesired effects resulting from this proximity are manifold and range from the establishment of hazardous potentials to the outbreak of alternate current corrosion phenomena. The study of this class of problems is necessary for ensuring security in the vicinities of the interaction zone and also to preserve the integrity of the equipment and of the devices there present. However, the complete modeling of this type of application requires the three- -dimensional representation of the region of interest and needs specific numerical methods for field computation. In this work, the modeling of problems arising from the flow of electrical currents in the ground (the so-called conductive coupling) will be addressed with the finite element method. Those resulting from the time variation of the electromagnetic fields (the so-called inductive coupling) will be considered as well, and they will be treated with the generalized PEEC (Partial Element Equivalent Circuit) method. More specifically, a special boundary condition on the electric potential is proposed for truncating the computational domain in the finite element analysis of conductive coupling problems, and a complete PEEC formulation for modeling inductive coupling problems is presented. Test configurations of increasing complexities are considered for validating the foregoing approaches. These works aim to provide a contribution to the modeling of this class of problems, which tend to become common with the expansion of power grids. / Les phénomènes de couplage électromagnétique entre les lignes aé- riennes de transmission d\'énergie et des structures voisines sont inévitables, surtout dans les zones densément peuplées. Les effets indésirables découlants de cette proximité sont variés, allant de l\'établissement des tensions dangereuses à l\'apparition de phénomènes de corrosion dus au courant alternatif. L\'étude de cette classe de problèmes est nécessaire pour assurer la sécurité dans les alentours de la zone d\'interaction et aussi pour préserver l\'intégrité des équipements et des dispositifs présents. Cependant, la modélisation compl ète de ce type d\'application implique la représentation tridimensionnelle de la région d\'intérêt et nécessite des méthodes numériques de calcul de champs spécifiques. Dans ces travaux, des problèmes liés à la circulation de courants électriques dans le sol (ou de couplage dit conductif) seront abordés avec la méthode des éléments finis. D\'autres problèmes résultants de la variation temporelle des champs électromagnétiques (ou de couplage dit inductif) seront aussi considérés et traités avec la méthode PEEC (Partial Element Equivalent Circuit) généralisée. Plus précisément, une condition limite particulière sur le potentiel électrique est proposée pour tronquer le domaine de calcul dans l\'analyse par éléments finis des problèmes de couplage conductif et une formulation PEEC complète pour la modélisation de problèmes de couplage inductif est présentée. Des con gurations tests de complexités croissantes sont considérées pour valider les approches précédentes. Ces travaux visent ainsi à apporter une contribution à la modélisation de cette classe de problèmes, qui tendent à devenir communs avec l\'expansion des réseaux électriques.

Este trabalho apresenta uma metodologia de projeto de atuadores eletromagnéticos lineares inovadora para aplicação em sistemas de suspensão semiativa e ativa. A metodologia, apresentada na forma de fluxograma, define critérios para determinar os requisitos de força e curso que um atuador deve desenvolver considerando um sistema mecânico vibratório com um grau de liberdade com excitação harmônica de base quando o método de controle skyhook é aplicado. Um atuador eletromagnético linear de bobina móvel com duplo arranjo de quase-Halbach que apresenta elevada densidade de força, reduzida massa móvel, ausência de força de relutância e baixa ondulação de força é definido como estudo de caso. Um modelo numérico parametrizado em elementos finitos do comportamento eletromagnético de um passo polar do dispositivo é criado e analisado, considerando restrições dimensionais, com os objetivos de projeto definidos como: elevada densidade de força e reduzida ondulação de força com acionamento brushless CA. Com base no modelo de um passo polar do dispositivo, define-se o volume ativo que o mesmo deve apresentar e, a partir deste, todas as dimensões são definidas de forma a atender os requisitos de projeto. Uma vez definidas as dimensões do atuador com base no modelo eletromagnético, realiza-se a modelagem térmica numérica que permite avaliar qual a máxima densidade de corrente elétrica aplicável de forma que a temperatura, estipulada como máxima, nos enrolamentos não seja excedida. Ainda, a distribuição térmica permite determinar a temperatura de operação dos ímãs permanentes que têm curva de operação dependente da temperatura. A partir dos resultados da simulação térmica e do modelo eletromagnético para um passo polar, realizou-se o acoplamento eletromagnético-térmico por meio da correção das propriedades dos ímãs permanentes e aplicando uma densidade de corrente eficaz dependente das dimensões do modelo parametrizado. O modelo acoplado é simulado e analisado, de modo que as dimensões finais do atuador podem ser obtidas atendendo aos mesmos objetivos de projeto previamente mencionados, respeitando os limites de operação térmica. Adicionalmente, são apresentados modelos analíticos do comportamento eletromagnético e térmico do atuador que podem servir de base para implementação da metodologia proposta, se esta for baseada em modelos analíticos, e podem futuramente ser empregados para a aplicação de otimização matemática do dispositivo. Por fim, um protótipo do dispositivo é construído de forma a validar a metodologia proposta. Com este protótipo são realizados ensaios de densidade de fluxo magnético no entreferro, tensão induzida a vazio, força estática e ensaio dinâmicos com o dispositivo instalado em uma bancada de testes de vibrações controladas desenvolvida durante o projeto. Os resultados mostram a eficácia da metodologia proposta, uma vez que os resultados experimentais mostraram boa concordância com os resultados esperados. / This work presents an innovative linear electromagnetic actuator design methodology for application in semi-active and active suspension systems. The methodology, synthesized in a flowchart, sets criteria to determine requirements such as axial force and stroke that an actuator should develop considering a vibration system with one degree of freedom with harmonic base excitation when the skyhook control method is applied. A linear moving-coil electromagnetic actuator with dual quasi-Halbach arrays of permanent magnets that presents high force density, low moving-mass, no reluctance force and low force ripple is defined as a case study. A finite element numerical parameterized model that describes the electromagnetic behavior of one pole pitch of the device is created and analyzed, considering dimensional constraints, with the design objectives defined as: high force density and low ripple of force with brushless AC drive. Based on the model of one pole pitch of the device the active volume and all dimensions are defined in order to meet the design requirements. Once the actuator dimensions are defined, based on the electromagnetic model, a numerical thermal model was constructed, which allows to evaluate the maximum applicable electric current density so that the maximum temperature at the windings is not exceeded. Furthermore, the thermal distribution gives the operating temperature of the permanent magnets, which present performance highly dependent on temperature. With the results of the thermal simulation, the electromagnetic-thermal coupling is performed by correcting permanent magnet properties and by applying a parametric-dependent effective current density. The coupled model is simulated and analyzed so that the final dimensions of the actuator can be obtained with the same design objectives previously mentioned, while respecting thermal operating limits. In addition, the work presents analytical models of the electromagnetic and thermal behavior of the actuator that can be the basis for implementation of the proposed methodology, if it is based on analytical models, and can further be used for the application of mathematical optimization of the device. Finally, a prototype was built to validate the proposed method. Measurements were carried out to assess magnetic flux density in the air gap, open-circuit induced voltage, static force and dynamic tests with the device installed in a test bench that was developed during this work. The results show the effectiveness of the proposed method since experimental results have shown good agreement with the expected results.

Este trabalho apresenta uma metodologia de projeto de atuadores eletromagnéticos lineares inovadora para aplicação em sistemas de suspensão semiativa e ativa. A metodologia, apresentada na forma de fluxograma, define critérios para determinar os requisitos de força e curso que um atuador deve desenvolver considerando um sistema mecânico vibratório com um grau de liberdade com excitação harmônica de base quando o método de controle skyhook é aplicado. Um atuador eletromagnético linear de bobina móvel com duplo arranjo de quase-Halbach que apresenta elevada densidade de força, reduzida massa móvel, ausência de força de relutância e baixa ondulação de força é definido como estudo de caso. Um modelo numérico parametrizado em elementos finitos do comportamento eletromagnético de um passo polar do dispositivo é criado e analisado, considerando restrições dimensionais, com os objetivos de projeto definidos como: elevada densidade de força e reduzida ondulação de força com acionamento brushless CA. Com base no modelo de um passo polar do dispositivo, define-se o volume ativo que o mesmo deve apresentar e, a partir deste, todas as dimensões são definidas de forma a atender os requisitos de projeto. Uma vez definidas as dimensões do atuador com base no modelo eletromagnético, realiza-se a modelagem térmica numérica que permite avaliar qual a máxima densidade de corrente elétrica aplicável de forma que a temperatura, estipulada como máxima, nos enrolamentos não seja excedida. Ainda, a distribuição térmica permite determinar a temperatura de operação dos ímãs permanentes que têm curva de operação dependente da temperatura. A partir dos resultados da simulação térmica e do modelo eletromagnético para um passo polar, realizou-se o acoplamento eletromagnético-térmico por meio da correção das propriedades dos ímãs permanentes e aplicando uma densidade de corrente eficaz dependente das dimensões do modelo parametrizado. O modelo acoplado é simulado e analisado, de modo que as dimensões finais do atuador podem ser obtidas atendendo aos mesmos objetivos de projeto previamente mencionados, respeitando os limites de operação térmica. Adicionalmente, são apresentados modelos analíticos do comportamento eletromagnético e térmico do atuador que podem servir de base para implementação da metodologia proposta, se esta for baseada em modelos analíticos, e podem futuramente ser empregados para a aplicação de otimização matemática do dispositivo. Por fim, um protótipo do dispositivo é construído de forma a validar a metodologia proposta. Com este protótipo são realizados ensaios de densidade de fluxo magnético no entreferro, tensão induzida a vazio, força estática e ensaio dinâmicos com o dispositivo instalado em uma bancada de testes de vibrações controladas desenvolvida durante o projeto. Os resultados mostram a eficácia da metodologia proposta, uma vez que os resultados experimentais mostraram boa concordância com os resultados esperados. / This work presents an innovative linear electromagnetic actuator design methodology for application in semi-active and active suspension systems. The methodology, synthesized in a flowchart, sets criteria to determine requirements such as axial force and stroke that an actuator should develop considering a vibration system with one degree of freedom with harmonic base excitation when the skyhook control method is applied. A linear moving-coil electromagnetic actuator with dual quasi-Halbach arrays of permanent magnets that presents high force density, low moving-mass, no reluctance force and low force ripple is defined as a case study. A finite element numerical parameterized model that describes the electromagnetic behavior of one pole pitch of the device is created and analyzed, considering dimensional constraints, with the design objectives defined as: high force density and low ripple of force with brushless AC drive. Based on the model of one pole pitch of the device the active volume and all dimensions are defined in order to meet the design requirements. Once the actuator dimensions are defined, based on the electromagnetic model, a numerical thermal model was constructed, which allows to evaluate the maximum applicable electric current density so that the maximum temperature at the windings is not exceeded. Furthermore, the thermal distribution gives the operating temperature of the permanent magnets, which present performance highly dependent on temperature. With the results of the thermal simulation, the electromagnetic-thermal coupling is performed by correcting permanent magnet properties and by applying a parametric-dependent effective current density. The coupled model is simulated and analyzed so that the final dimensions of the actuator can be obtained with the same design objectives previously mentioned, while respecting thermal operating limits. In addition, the work presents analytical models of the electromagnetic and thermal behavior of the actuator that can be the basis for implementation of the proposed methodology, if it is based on analytical models, and can further be used for the application of mathematical optimization of the device. Finally, a prototype was built to validate the proposed method. Measurements were carried out to assess magnetic flux density in the air gap, open-circuit induced voltage, static force and dynamic tests with the device installed in a test bench that was developed during this work. The results show the effectiveness of the proposed method since experimental results have shown good agreement with the expected results.

Este trabalho apresenta uma metodologia de projeto de atuadores eletromagnéticos lineares inovadora para aplicação em sistemas de suspensão semiativa e ativa. A metodologia, apresentada na forma de fluxograma, define critérios para determinar os requisitos de força e curso que um atuador deve desenvolver considerando um sistema mecânico vibratório com um grau de liberdade com excitação harmônica de base quando o método de controle skyhook é aplicado. Um atuador eletromagnético linear de bobina móvel com duplo arranjo de quase-Halbach que apresenta elevada densidade de força, reduzida massa móvel, ausência de força de relutância e baixa ondulação de força é definido como estudo de caso. Um modelo numérico parametrizado em elementos finitos do comportamento eletromagnético de um passo polar do dispositivo é criado e analisado, considerando restrições dimensionais, com os objetivos de projeto definidos como: elevada densidade de força e reduzida ondulação de força com acionamento brushless CA. Com base no modelo de um passo polar do dispositivo, define-se o volume ativo que o mesmo deve apresentar e, a partir deste, todas as dimensões são definidas de forma a atender os requisitos de projeto. Uma vez definidas as dimensões do atuador com base no modelo eletromagnético, realiza-se a modelagem térmica numérica que permite avaliar qual a máxima densidade de corrente elétrica aplicável de forma que a temperatura, estipulada como máxima, nos enrolamentos não seja excedida. Ainda, a distribuição térmica permite determinar a temperatura de operação dos ímãs permanentes que têm curva de operação dependente da temperatura. A partir dos resultados da simulação térmica e do modelo eletromagnético para um passo polar, realizou-se o acoplamento eletromagnético-térmico por meio da correção das propriedades dos ímãs permanentes e aplicando uma densidade de corrente eficaz dependente das dimensões do modelo parametrizado. O modelo acoplado é simulado e analisado, de modo que as dimensões finais do atuador podem ser obtidas atendendo aos mesmos objetivos de projeto previamente mencionados, respeitando os limites de operação térmica. Adicionalmente, são apresentados modelos analíticos do comportamento eletromagnético e térmico do atuador que podem servir de base para implementação da metodologia proposta, se esta for baseada em modelos analíticos, e podem futuramente ser empregados para a aplicação de otimização matemática do dispositivo. Por fim, um protótipo do dispositivo é construído de forma a validar a metodologia proposta. Com este protótipo são realizados ensaios de densidade de fluxo magnético no entreferro, tensão induzida a vazio, força estática e ensaio dinâmicos com o dispositivo instalado em uma bancada de testes de vibrações controladas desenvolvida durante o projeto. Os resultados mostram a eficácia da metodologia proposta, uma vez que os resultados experimentais mostraram boa concordância com os resultados esperados. / This work presents an innovative linear electromagnetic actuator design methodology for application in semi-active and active suspension systems. The methodology, synthesized in a flowchart, sets criteria to determine requirements such as axial force and stroke that an actuator should develop considering a vibration system with one degree of freedom with harmonic base excitation when the skyhook control method is applied. A linear moving-coil electromagnetic actuator with dual quasi-Halbach arrays of permanent magnets that presents high force density, low moving-mass, no reluctance force and low force ripple is defined as a case study. A finite element numerical parameterized model that describes the electromagnetic behavior of one pole pitch of the device is created and analyzed, considering dimensional constraints, with the design objectives defined as: high force density and low ripple of force with brushless AC drive. Based on the model of one pole pitch of the device the active volume and all dimensions are defined in order to meet the design requirements. Once the actuator dimensions are defined, based on the electromagnetic model, a numerical thermal model was constructed, which allows to evaluate the maximum applicable electric current density so that the maximum temperature at the windings is not exceeded. Furthermore, the thermal distribution gives the operating temperature of the permanent magnets, which present performance highly dependent on temperature. With the results of the thermal simulation, the electromagnetic-thermal coupling is performed by correcting permanent magnet properties and by applying a parametric-dependent effective current density. The coupled model is simulated and analyzed so that the final dimensions of the actuator can be obtained with the same design objectives previously mentioned, while respecting thermal operating limits. In addition, the work presents analytical models of the electromagnetic and thermal behavior of the actuator that can be the basis for implementation of the proposed methodology, if it is based on analytical models, and can further be used for the application of mathematical optimization of the device. Finally, a prototype was built to validate the proposed method. Measurements were carried out to assess magnetic flux density in the air gap, open-circuit induced voltage, static force and dynamic tests with the device installed in a test bench that was developed during this work. The results show the effectiveness of the proposed method since experimental results have shown good agreement with the expected results.

Les propriétés optiques et vibrationnelles de nanoparticules métalliques individuelles ont été étudiées par spectroscopie par modulation spatiale (SMS), avec une attention particulière aux effets de forme, composition, environnement local, ainsi que de couplage inter-particule. La réponse optique de nanoparticules (métalliques au cœur-couronne métal-diélectrique) allongées et des particules bimétalliques (hétérodimères or-argent) a été mesuré et en suite interprétée grâce à une corrélation avec la caractérisation morphologique de la même particule obtenue par microscopie à transmission électronique et avec des simulations par éléments finis prenants en compte la réelle géométrie du nano-objet et le substrat. Une technique pompe sonde résolue en temps a été en suite utilisée pour étudier le profil Fano dans l'absorption d'une particule d'or au sein d'un hétérodimères or-argent. Sur une échelle de temps des quelques dizaines de picosecondes, les vibrations acoustiques multimodales de nanobipyramides d'or individuelles ont été optiquement détectées et caractérisées par rapport à un modèle élastique classique / Optical and vibrational properties of individual metal-based nanoparticles have been investigated by spatial modulation spectroscopy (SMS), focusing on their dependence on nano-object shape, composition, environment and inter-particle coupling. Quantitative investigations of the optical response, and in particular, the surface plasmon resonance (extinction cross-section amplitude, spectral position and linewidth) of elongated metal or metal-dielectric (gold nanorods, nanobipyramids with or without silica coating) and bimetallic (gold-silver heterodimers) nanoparticles deposited on a substrate have first been performed. The same nanoparticles were characterized by electron microscopy permitting quantitative interpretation of their optical response using finite element numerical simulations, taking into account the influence of the substrate. Combining SMS microscopy with a high sensitivity femtosecond two-color pump-probe setup, the ultrafast dynamics of single nano-objects has been investigated. The Fano absorption profile of a gold nanoparticle within a single gold-silver heterodimer, a parameter not accessible by linear spectroscopy, was directly measured. On a picosecond time-scale, multimodal acoustic vibrations of single gold nanobipyramids were optically lunched and detected, and their features compared to a model based on continuum elasticity

La miniaturisation, la fabrication et l'intégration des composants passifs RF constituent des enjeux majeurs actuels, sans oublier le critère du coût de fabrication, très important notamment pour les applications grand public. Les composants passifs tels que les inductances et les transformateurs font l'objet d'un effort de développement permanent pour accroitre leurs performances et réduire la surface occupée. Les travaux décrits dans ce manuscrit s'inscrivent dans ce contexte et visent le développement d'une nouvelle filière technologique permettant la réalisation à faible coût de composants inductifs tridimensionnels à hautes performances. Le travail présenté dans ce mémoire s'articule en quatre chapitres. Le premier chapitre dresse un état de l'art des inductances et des transformateurs intégrés en abordant les principales topologies utilisées, les technologies de fabrication et les applications. Dans le deuxième chapitre, l'étude et l'optimisation des inductances et des transformateurs solénoïdaux est abordée après avoir décrit les origines des pertes limitant les performances. Pour cela, nous avons recours à la simulation électromagnétiques 3D. Dans le troisième chapitre, un problème de caractérisation des composants inductifs à forts coefficients de surtension est soulevé. Après avoir constaté que l'environnement de mesure réduisait artificiellement les performances, quelques solutions sont proposées et vérifiées expérimentalement. Enfin, le dernier chapitre traite de la fabrication et de la caractérisation des composants mis au point. Les meilleures performances mesurées correspondent à un facteur de qualité de 61 à 5,4 GHz pour une inductance de 2,5 nH et un gain maximum disponible de -0,5 dB à -0,39 dB sur la plage 3,8 - 6,5 GHz pour un transformateur 2:2. Ces résultats placent ces composants parmi les meilleures réalisations actuelles. / The miniaturization, fabrication and integration of RF passive components are current major challenges, also taking into account the fabrication cost which is very important especially for consumer applications. Passive components such as inductors and transformers are subject to an ongoing development to improve their performance and reduce the area occupied. The work described in this manuscript is part of that context and target the development of a new technological process allowing the production of low-cost three-dimensional high-performance inductive components. The work presented in this paper is divided into four chapters. The first chapter describes the state of the art of integrated inductors and transformers by addressing the main topologies used fabrication technologies and applications. In the second chapter, the study and optimization of solenoid inductors and transformers is discussed after describing the origins of performance limiting losses. For this, we use the 3D electromagnetic simulation. In the third chapter, the problem concerning the characterization of inductive components with high Q factor is raised. After finding that the measurement environment artificially reduces performance, some solutions are proposed and experimentally verified. Finally, the last chapter discusses the fabrication and characterization of developed components. The best measured performance corresponds to a quality factor of 61 to 5.4 GHz for an inductance value of 2.5 nH and a maximum available gain of -0.5 dB to 0.39 dB over the range from 3.8 to 6.5 GHz for a 2:2 transformer. These results place these components among the best current achievements.

Yes / This paper presents a novel on-chip antenna using standard CMOS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. The aluminium ground-plane with thickness of 3 μm is sandwiched between the two-layers. Concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. The radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the ground-plane using a microstrip feedline created on the bottom polyimide-layer. The open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. In this structure, the concentric metal-rings essentially act as series left-handed capacitances CL that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors LL, which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350–0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm3 that makes it suitable for on-chip implementation. / This work is partially supported by RTI2018-095499-B-C31, Funded by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE), and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424 and the fnancial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1. / Research Development Fund Publication Prize Award winner, March 2020

Ce manuscrit se focalise sur l’effet de divers matériaux composites sur les différentes problématiques de compatibilité électromagnétique dans un véhicule automobile. Les modèles surfaciques des matériaux diélectriques sont validés en confrontant des résultats de mesures et de simulation de leurs permittivités. Ceux des matériaux conducteurs le sont en confrontant le modèle d’impédance de surface à un modèle filaire et en effectuant des mesures des simulations de paramètres S sur une structure majoritairement constituée par un matériau de ce type. Dans les deux cas, la technique de modélisation donne de bons résultats. L’évaluation de l’effet de ces matériaux sur les problématiques de CEM au niveau d’un véhicule est faite sur un démonstrateur qui intègre les équipements et les faisceaux embarqués dans un véhicule en les représentants par des monopôles et des fils conducteurs. L’évaluation des effets des différents matériaux composites sur les problématiques CEM est faite par mesure et simulation des couplages électromagnétiques à l’intérieur du démonstrateur et entre le démonstrateur et une antenne test. L’analyse des couplages électromagnétiques confirme que le modèle d’impédance de surface reproduit assez bien les comportements des matériaux composites étudiés. Concernant l’effet des matériaux composites sur les problématiques CEM au niveau d’un véhicule, cette étude mène à deux résultats majeurs du point de vue de la compatibilité électromagnétique. Le premier concerne l’usage des matériaux diélectriques qui augmente globalement la plupart des couplages mesurés de 5 dB à 30 dB. Le second porte sur le matériau conducteur étudié qui n’a quasiment aucun effet sur les différents couplages analysés en comparaison de la structure en acier. / The main concern of this thesis is the characterization of the impacts of some composite materials on the main electromagnetic compatibility issues in a vehicle. The surface models of the dielectric materials are validated by confronting their simulated and measured permittivity. The surface model of the studied conductive material is validated by confronting it to a wire model and by measuring and simulating the S parameters on a structure constituted by such a material. It appears in both cases of dielectric and conductive composite materials that the surface impedance modeling technique gives a good description of the materials. The analysis of the effects of these materials on the EMC issues within a vehicle is done by use of a demonstrator representing the car body. The different equipment and harnesses embedded in a vehicle are represented in the demonstrator by some wires and monopoles. The evaluation of the impact of the composite materials on the EMC issues is done by measuring and simulating the different couplings within the demonstrator and between the demonstrator and a test antenna. The analysis of the different couplings confirms that the surface impedance material modeling approach describes well the materials under test. Concerning the impact of the composite materials on the EMC issues at a vehicle level, this analysis fulfills two main results. The first one concerns the dielectric materials. Indeed the use of these materials increases the different coupling by a value varying between at least 5 dB to 30 dB. The second conclusion concerns the use of conductive composite materials. It appears that they have no effect on the different couplings in comparison to the full steel structure.

Les phénomènes de couplage électromagnétique entre les lignes aériennes de transmission d'énergie et des structures voisines sont inévitables, surtout dans les zones densément peuplées. Les effets indésirables découlants de cette proximité sont variés, allant de l'établissement des tensions dangereuses à l'apparition de phénomènes de corrosion dus au courant alternatif. L'étude de cette classe de problèmes est nécessaire pour assurer la sécurité dans les alentours de la zone d'interaction et aussi pour préserver l'intégrité des équipements et des dispositifs présents. Cependant, la modélisation complète de ce type d'application implique la représentation tridimensionnelle de la région d'intérêt et nécessite des méthodes numériques de calcul de champs spécifiques. Dans ces travaux, des problèmes liés à la circulation de courants électriques dans le sol (ou de couplage dit conductif) seront abordés avec la méthode des éléments finis. D'autres problèmes résultants de la variation temporelle des champs électromagnétiques (ou de couplage dit inductif) seront aussi considérés et traités avec la méthode PEEC (Partial Element Equivalent Circuit) généralisée. Plus précisément, une condition limite particulière sur le potentiel électrique est proposée pour tronquer le domaine de calcul dans l'analyse par éléments finis des problèmes de couplage conductif et une formulation PEEC complète pour la modélisation de problèmes de couplage inductif est présentée. Des configurations tests de complexités croissantes sont considérées pour valider les approches précédentes. Ces travaux visent ainsi à apporter une contribution à la modélisation de cette classe de problèmes, qui tendent à devenir communs avec l'expansion des réseaux électriques. / Electromagnetic coupling phenomena between overhead power transmission lines and other nearby structures are inevitable, especially in densely populated areas. The undesired effects resulting from this proximity are manifold and range from the establishment of hazardous potentials to the outbreak of alternate current corrosion phenomena. The study of this class of problems is necessary for ensuring security in the vicinities of the interaction zone and also to preserve the integrity of equipment and devices there present. However, the complete modeling of this type of application requires the three-dimensional representation of the region of interest and needs specific numerical methods for field computation. In this work, the modeling of problems arising from the flow of electrical currents in the ground (the so-called conductive coupling) will be addressed with the finite element method. Those resulting from the time variation of the electromagnetic fields (the so-called inductive coupling) will be considered as well, and they will be treated with the generalized PEEC (Partial Element Equivalent Circuit) method. More specifically, a special boundary condition on the electric potential is proposed for truncating the computational domain in the finite element analysis of conductive coupling problems, and a complete PEEC formulation for modeling inductive coupling problems is presented. Test configurations of increasing complexities are considered for validating the foregoing approaches. These works aim to provide a contribution to the modeling of this class of problems, which tend to become common with the expansion of power grids. / Fenômenos de acoplamento eletromagnético entre linhas aéreas de transmissão de energia e outras estruturas vizinhas são inevitáveis, sobretudo emáreas densamente povoadas. Os efeitos indesejados decorrentes desta proximidadesão variados, indo desde o estabelecimento de potenciais perigosos até o surgimento de processos de corrosão por corrente alternada. O estudo desta classe de problemas é necessária para a garantia da segurança nas imediações da zona de interação e também para se preservar a integridade de equipamentos e dispositivos ali presentes. Entretanto, a modelagem completa deste tipo de aplicação requer a representação tridimensional da região de interesse e necessita de métodos numéricos de cálculo de campos específicos. Neste trabalho, serão abordadas as modelagens de problemas decorrentes da circulação de correntes elétricas no solo (ditos de acoplamentocondutivo) com o método dos elementos finitos. Também serão considerados problemas produzidos pela variação temporal dos campos eletromagnéticos (ditos de acoplamento indutivo), que serão tratados com o método PEEC(Partial Element Equivalent Circuit) generalizado. Mais especificamente, uma condição de contorno particular sobre o potencial elétrico é proposta para o truncamento do domínio de cálculo na análise de problemas de acoplamento condutivo com o método dos elementos finitos, e uma formulação completa tipo PEEC para a modelagem de problemas de acoplamento indutivo é apresentada. Problemas teste de complexidades crescentes são considerados para a validação das abordagens precedentes. Estes trabalhos visam fornecer desta forma uma contribuição à modelagem desta classe de problemas, que tendem a se tornar comuns com a expansão das redes elétricas.