Approved for public release, distribution is unlimited / Optical fiber has been the preferred cabling technology for certain building and campus network LAN backbones. Until recently, however, the use of fiber as a cabling medium to the desktop has been confined to special environments that require the unique properties of optical fiber such as noise immunity, security, distance, high bandwidth demands (CAD/CAM, video conferencing), and immunity to electrical interference. However, choosing to use optical fiber in a network over other cabling options may present significant advantages in its inherent ability to handle data at higher speeds. Decreasing costs of optical fiber components compared to the increasing electronic costs of carrying Gigabit Ethernet over Cat 5 or Cat 5E UTP copper cabling has also accelerated the migration to optical fiber LAN. The thesis conducts a feasibility study of implementing a Fiber Optic Local Area Network in Software Metrics Laboratory in Ingersoll 158. / Major, Republic of Singapore Air Force

To date, over 84% of countries worldwide have renewable energy targets (RET), requiring that a certain amount of electricity be produced from renewable sources by a target date. Despite the worldwide prevalence of these policies, little research has been conducted on ex-ante RET policy analysis. In an effort to move toward evidence-based policymaking, this thesis develops computational models to assess the tradeoffs associated with alternatives for both RET achievement and RET policy formulation, including the option of creating renewable energy credit (REC) markets to facilitate meeting an RET goal. A mixed integer linear program (MILP), a probabilistic cost prediction model and a mixed complementarity problem (MCP) serve as the theoretical bases for the RET alternative and policy formulation analyses. From these models it was found, inter alia, that RET goals set too low run the risk of creating technological lock-in and could inhibit achievement of higher goals; probabilistic cost predictions give decision-makers essential risk information, when cost estimation is an integral part of alternatives assessment; and though REC markets may facilitate RET achievement, including REC markets in an RET policy formulation may not result in the lowest possible greenhouse gas emissions (GHG).

Cable ampacity analysis is generally performed assuming constant worst-state environmental conditions, which often correspond to a dry soil condition or to a condition with uniform ambient soil moisture content. The characteristic time scale of thermal variation in the soil is large, on the order of several weeks, and is similar to the time scale between rainfall events in many geographic locations. Intermittent rainfall events introduce significant transient fluctuations that influence the thermal conditions and moisture content around a buried cable both by increasing thermal conductivity of the soil and by increasing the moisture exposure of the cable insulation. This paper reports on a computational study of the effect of rainfall events on the thermal and moisture transients surrounding a buried cable. The computations were performed with a finite-difference method using an overset grid approach, with an inner polar grid surrounding the cable and an outer Cartesian grid. The thermal and moisture transients observed in computations with periodic rainfall events were compared to control computations with a steady uniform rainfall. Under periodic rainfall conditions, the temperature and moisture fields are observed to approach a limit-cycle condition in which the cable surface temperature and moisture content oscillate in time, but with mean values that are significantly different than the steady-state values.

Cette thèse porte sur l'étude et la réalisation d’un prototype de capteur de courants innovant pour câbles multiconducteurs. Outre le caractère non-Intrusif de ce capteur (i.e. mesure sans contact), il permet de réaliser une mesure sur un système polyphasé dont la position des conducteurs est inconnue. L’approche adoptée est basée sur la résolution d’un problème inverse. En effet, à partir d’une mesure de la signature des champs magnétiques autour du câble, des algorithmes de reconstruction appropriés permettent de remonter aux courants circulant dans le câble. En plus des résultats de simulation, un banc de tests a été conçu et une validation expérimentale de ce concept est présentée pour répondre à un cahier des charges, notamment pour une structure comportant un blindage en matériau ferromagnétique pour atténuer les perturbations extérieures / This thesis presents the study and realization of an innovative currents sensor prototype for multi-Core cables. The two main advantages of this sensor compared to existing devices on the electrical equipment market are: firstly, it is no longer necessary to interrupt the system's electrical power supply to install the sensor. This is due to contactless measure (non-Intrusive sensor). Another feature of our device is its capability to measure the currents in a multi-Core system with unknown positions of conductors. This currents sensor operates in a way to find firstly the conductor positions, and then reconstructing the currents using the retrieved positions. In order to meet specifications, simulation results, test bench measurements and experimental results are presented with a ferromagnetic shielding

Atualmente, a intensidade de campo elétrico, campo magnético e campo eletromagnético é um fator determinante não só para a implantação de novas instalações, mas também, para as instalações existentes no sistema elétrico. Apesar de não existir nenhum estudo conclusivo que comprove a evidência direta entre a exposição a estes campos e os efeitos nocivos na saúde das pessoas, muitos países, inclusive o Brasil, definiram em suas legislações limites básicos à exposição de campos elétrico e magnético provenientes dos sistemas elétricos. Este trabalho tem como objetivo contribuir para análise de campo magnético de linhas subterrâneas de alta tensão existentes ou linhas em fase inicial de projeto, visando atender os limites de exposição vigentes na legislação local. Nele é apresentada a metodologia de cálculo de campo magnético baseada na Lei de Biot-Savart e no princípio da superposição. Estudos analíticos para verificação da influência dos parâmetros de instalação e elétricos de linhas sobre o campo magnético são apresentados para linhas subterrâneas de alta tensão compostas por um e dois circuitos com diferentes tipos de instalação e aterramentos. Comparações entre valores analíticos e valores de medições de campo magnético de linhas subterrâneas de alta tensão existentes em operação também são abordadas neste trabalho. As principais técnicas de mitigação de campo magnético utilizadas em linhas subterrâneas de alta tensão, tais como técnicas de compensação envolvendo laços de cabos e técnicas de blindagens com materiais metálicos externos aos cabos, também são apresentadas. Devido ao campo elétrico externo ao cabo isolado ser praticamente zero, assuntos referentes a este campo não são abordados neste trabalho. Por simplicidade, campo magnético refere-se à densidade de fluxo magnético neste documento. / Nowadays, the intensity of electric field, magnetic field and electromagnetic field is a determining factor, not only for implantation of new installations, but also for existing installations in the power system. Although no exist conclusive study that proves the direct evidence between exposure to these fields and adverse effects on human health, many countries, including Brazil, have defined in their laws basic limits for exposure to electric and magnetic fields produced by the electric system. This work aims to contribute to analysis of magnetic field for both existing high voltage underground lines and lines in initial stage of project, aiming the actual exposure limits of the local legislation. In it, is shown the magnetic field calculation methodology based on the Biot-Savart\'s law and the superposition principle. Analytical studies to verify the influence of installation and electrical parameters of lines on the magnetic field are presented for high voltage underground lines consist of one and two circuits with different types of installation and earthing. Comparisons between analytical and measurement values of magnetic field of existing high voltage underground lines in operation are also addressed in this work. The main mitigation techniques of magnetic field used in high voltage underground lines, such as compensation techniques by loop of cables and shielding by metallic materials, are also presented. Due the electric field outside the insulated cable be practically zero, issues related to the electric field are not addressed in this work. For simplicity, the magnetic field refers to the magnetic flux density in this document.

Este trabalho desenvolve e apresenta um modelo tridimensional em elementos finitos de um cabo umbilical do tipo STU (Steel Tube Umbilical) utilizado na extração offshore de petróleo. Tal modelo é utilizado para estudar o carregamento de crushing, que é imposto ao cabo umbilical pelas sapatas do tensionador durante o seu lançamento, de modo a obter de forma detalhada a distribuição de tensões nos componentes do núcleo, com foco nos tubos de aço utilizados para o transporte de fluidos. A metodologia empregada no desenvolvimento do modelo é descrita detalhadamente ao longo do trabalho, de forma que possa vir a ser utilizada no estudo de outras configurações de cabos umbilicais. O modelo elaborado é utilizado (i) como paradigma para a validação de um modelo bidimensional, que visa analisar o mesmo problema de forma mais simples e rápida, e (ii) para o estudo do comportamento das tensões nos tubos de aço na região de transição de entrada/saída da sapata. Na comparação entre os modelos bi e tridimensional, o trabalho conclui pela validade do modelo bidimensional na avaliação das tensões nos tubos de aço resultantes do carregamento de crushing, na região central do cabo. O estudo realizado na região de transição de entrada/saída da sapata permitiu verificar que ocorre um aumento dos níveis de tensão nos tubos de aço nessas regiões de transição, com redistribuição do campo de tensões após plastificação. / This project proposes a three-dimensional finite element model of a Steel Tube Umbilical Cable used in the offshore oil extraction. This model is used to study the crushing load imposed to the cable by the shoes of the tensioner during its installation, in order to obtain a detailed distribution of stresses in the components of the core, focusing on the steel tubes used for fluid transportation. The methodology employed in the development of the model will be fully described throughout the study, allowing to reproduce it in the analysis of different umbilical configurations. The developed model is used (i) as a paradigm for the validation of a two-dimensional model, which aims to analyze the same problem in an easier and faster manner, and (ii) to study the behavior of the stresses in the steel tubes in the entry/exit transition region of the shoe. Comparison between the two and three-dimensional models allows to conclude for the validity of the two-dimensional in evaluating the stresses in the steel tube resulting from the crushing load, in the central region of the cable. The study performed in the entry/exit transition region of the shoe has enabled do verify that there is an increase of the stress levels in the steel tubes in these transition regions, with field stress redistribution after plastification.

Este trabalho é um conjunto de conhecimentos sistematizado, alguns já disponíveis através da engenharia e/ou da tecnologia, e outros desenvolvidos durante este trabalho para solução de problemas que freqüentemente se apresentam na modalidade de instalação de linhas de transmissão subterrânea enterradas diretamente no solo. Nas linhas de transmissão diretamente enterrada, a corrente máxima circulante nos condutores depende do salto térmico entre o condutor e a temperatura máxima do solo em um ponto remoto onde os cabos estão instalados. Duas variáveis além da corrente teem um papel de extrema relevância: A resistência elétrica do condutor e blindagens que define as perdas joules geradas pelos condutores e capas metálicas, respectivamente e a resistência térmica externa do solo circunstante ao cabo enterrado. A parte devido às perdas joules já foi exaustivamente estudada e sistematização atual é suficiente para a solução da maioria dos problemas de engenharia, mas a parte do conhecimento da resistência térmica externa tem ainda muitos pontos que ainda não foram totalmente esclarecidos: sejam na modelagem, sejam nos materiais sejam no controle da fenomenologia. O escopo deste trabalho é dar uma contribuição no papel da resistência térmica externa aos cabos enterrados através de uma engenharia simultânea (Elétrica, Mecânica e Civil) assistida por tecnologia de desenvolvimento de materiais (Backfill). / The present work is a set of systematized knowledge, some of them available in the engineering and technological literature and others developed during this work to solve problems which presents in direct buried cables modalities. In direct buried transmission lines the current carrying in the conductors depends on the temperature rise of the conductor in respect of the temperature of remote soil. Two variables beyond the electrical current on the conductor play a paramount role: The electrical resistance of the conductor and sheaths which define the Joules losses upon the conductor and sheath and the thermal resistance between cable and soil. The role of Joule losses has been sufficiently studied providing solutions for large class of engineering problems, but the available knowledge regarding external thermal resistivity has several points under considerations yet: Even in modeling, materials and phenomenology control. The scope of this work is to present a short contribution on the role of external thermal resistance between cables and soil through the simultaneous frame work (Electrical, Mechanical and Civil engineering) and Technological development of materials (Backfill).

Este trabalho é um conjunto de conhecimentos sistematizado, alguns já disponíveis através da engenharia e/ou da tecnologia, e outros desenvolvidos durante este trabalho para solução de problemas que freqüentemente se apresentam na modalidade de instalação de linhas de transmissão subterrânea enterradas diretamente no solo. Nas linhas de transmissão diretamente enterrada, a corrente máxima circulante nos condutores depende do salto térmico entre o condutor e a temperatura máxima do solo em um ponto remoto onde os cabos estão instalados. Duas variáveis além da corrente teem um papel de extrema relevância: A resistência elétrica do condutor e blindagens que define as perdas joules geradas pelos condutores e capas metálicas, respectivamente e a resistência térmica externa do solo circunstante ao cabo enterrado. A parte devido às perdas joules já foi exaustivamente estudada e sistematização atual é suficiente para a solução da maioria dos problemas de engenharia, mas a parte do conhecimento da resistência térmica externa tem ainda muitos pontos que ainda não foram totalmente esclarecidos: sejam na modelagem, sejam nos materiais sejam no controle da fenomenologia. O escopo deste trabalho é dar uma contribuição no papel da resistência térmica externa aos cabos enterrados através de uma engenharia simultânea (Elétrica, Mecânica e Civil) assistida por tecnologia de desenvolvimento de materiais (Backfill). / The present work is a set of systematized knowledge, some of them available in the engineering and technological literature and others developed during this work to solve problems which presents in direct buried cables modalities. In direct buried transmission lines the current carrying in the conductors depends on the temperature rise of the conductor in respect of the temperature of remote soil. Two variables beyond the electrical current on the conductor play a paramount role: The electrical resistance of the conductor and sheaths which define the Joules losses upon the conductor and sheath and the thermal resistance between cable and soil. The role of Joule losses has been sufficiently studied providing solutions for large class of engineering problems, but the available knowledge regarding external thermal resistivity has several points under considerations yet: Even in modeling, materials and phenomenology control. The scope of this work is to present a short contribution on the role of external thermal resistance between cables and soil through the simultaneous frame work (Electrical, Mechanical and Civil engineering) and Technological development of materials (Backfill).

Cette thèse porte sur l’analyse et la modélisation des interactions électromagnétiques sur des torons aéronautiques constitués de câbles multiconducteurs représentatifs de la réalité industrielle. En effet les évolutions technologiques (introduction de matériaux composites, augmentation des fonctions électriques,..) conduisent à revoir les niveaux d’exigence des couplages électromagnétiques sur torons de câbles. Ainsi, les outils de dimensionnement de ces couplages s’avèrent indispensables pour décider des choix technologiques d’architectures des câblages.Dans ce contexte, les codes numériques basés sur la théorie des lignes de transmission permettent de calculer les couplages électromagnétiques au sein de torons multiconducteurs. Ces modèles numériques doivent être alimentés par la description géométrique des sections droites de toron. Un outil logiciel de génération de sections droites de toron a étévalidé dans un premier temps par comparaison à une référence bibliographique, puis par une étude expérimentale d’un toron réel d’A380. Cette étude de suivi de positionnement de conducteur dans le toron a mis en évidence que le cheminement des câbles au sein du toron dépendait de leur rigidité. Ainsi, la bifilaire torsadée non blindée est le câble dont le cheminement est le moins maîtrisé. De plus, ce type de câble très couramment utilisé pour transmettre desdonnées en mode différentiel, est à l’origine de couplages spécifiques qu’il est essentiel d’analyser pour correctement les modéliser. Par conséquent, le premier cas étudié est composé d’une bifilaire torsadée agresseur et d’une monofilaire victime. Les simulations numériques ont montré que les courants induits le long de la monofilaire victime présentaient un motif propre à la torsade de la bifilaire agresseur. Ce motif a été expliqué par une approche analytique et confirmé par expérimentations. La prise en compte des torsades dans une simulation numérique induisant des temps de calculs prohibitifs, un modèle simplifié de câble torsadé basé sur un moyennage des paramètres linéiques a été développé et validé. L’effet des extrémités dé-torsadées résultant de la connectorisation a également été évalué d’un point de vue numérique et expérimental. Les cas d’étude ont ensuite été complexifiés à des couplages entre bifilaires torsadées jusqu’à traiter un toron réel de plus de 60 conducteurs. Un banc expérimental a été développé. La modélisation numérique de ce toron complexe a été réalisée et les résultats numériques de couplages électromagnétiques confrontés aux données expérimentales. En vue de réduire considérablement les temps de calculs, le modèle simplifié a étéappliqué à ce toron. Sa potentialité a été démontrée. Une analyse statistique de la dispersion des couplages lectromagnétiques au sein de ce toron complexe a finalement été abordée. / This thesis focuses on the analysis and the modeling of electromagnetic interactions on aeronautical bundles made of multicore cables representative of the industrial reality. Indeed, technological changes (introduction of composite materials, increased electrical functions, ...) force to reconsider the requirement levels of electromagnetic coupling on cable bundles. Thus, the design tools of these electromagnetic couplings are essential to help to technological choices of architectureswiring. In this context, numerical software based on transmission line theory can calculate the electromagnetic coupling in complex bundles. These numerical models need the geometric description of bundles cross sections. A software tool for generating bundles cross sections was initially validated by comparison to a bibliographic reference, followed by anexperimental study of a real bundle arised from an A380. This analysis of conductors positioning along the bundle showed that the cable routing depends on the cable stiffness. Thus, the unshielded twisted cable appears to be the cable which routing is less controlled. In addition, this type of cable most commonly used to tr nsmit data in differential mode can generate specific couplings which are important to analyze for correctly modeling this cable. Therefore, the first case studied is composed of a twisted pair cable aggressor and a single victim wire. Numerical simulations have shownthat the induced currents along the victim wire had a behavior specific to the twist of the twisted pair cable aggressor. This pattern has been explained by an analytical approach and confirmed by experiments. Taking into account twists in numerical simulation leads to prohibitive computational time. Therefore, a simplified model based on averagingparameters per unit length of twisted cable was developed and validated. The effect of untwisted ends resulting from connection was also assessed numerically and experimentally. Case studies were complicated to coupling between twisted pair cabl es and finally to a real bundle with more than 60 wires. An experimental bench was developed. Numerical modeling of the complex bundle has been carried out and numerical results of electromagnetic couplings compared to experimental data. In order to significantly reduce the computation time, the simplified model was applied to this bundle. Itsefficiency has been demonstrated. A statistical analysis of the dispersion of electromagnetic couplings within this complex bundle was finally addressed.

Atualmente, a intensidade de campo elétrico, campo magnético e campo eletromagnético é um fator determinante não só para a implantação de novas instalações, mas também, para as instalações existentes no sistema elétrico. Apesar de não existir nenhum estudo conclusivo que comprove a evidência direta entre a exposição a estes campos e os efeitos nocivos na saúde das pessoas, muitos países, inclusive o Brasil, definiram em suas legislações limites básicos à exposição de campos elétrico e magnético provenientes dos sistemas elétricos. Este trabalho tem como objetivo contribuir para análise de campo magnético de linhas subterrâneas de alta tensão existentes ou linhas em fase inicial de projeto, visando atender os limites de exposição vigentes na legislação local. Nele é apresentada a metodologia de cálculo de campo magnético baseada na Lei de Biot-Savart e no princípio da superposição. Estudos analíticos para verificação da influência dos parâmetros de instalação e elétricos de linhas sobre o campo magnético são apresentados para linhas subterrâneas de alta tensão compostas por um e dois circuitos com diferentes tipos de instalação e aterramentos. Comparações entre valores analíticos e valores de medições de campo magnético de linhas subterrâneas de alta tensão existentes em operação também são abordadas neste trabalho. As principais técnicas de mitigação de campo magnético utilizadas em linhas subterrâneas de alta tensão, tais como técnicas de compensação envolvendo laços de cabos e técnicas de blindagens com materiais metálicos externos aos cabos, também são apresentadas. Devido ao campo elétrico externo ao cabo isolado ser praticamente zero, assuntos referentes a este campo não são abordados neste trabalho. Por simplicidade, campo magnético refere-se à densidade de fluxo magnético neste documento. / Nowadays, the intensity of electric field, magnetic field and electromagnetic field is a determining factor, not only for implantation of new installations, but also for existing installations in the power system. Although no exist conclusive study that proves the direct evidence between exposure to these fields and adverse effects on human health, many countries, including Brazil, have defined in their laws basic limits for exposure to electric and magnetic fields produced by the electric system. This work aims to contribute to analysis of magnetic field for both existing high voltage underground lines and lines in initial stage of project, aiming the actual exposure limits of the local legislation. In it, is shown the magnetic field calculation methodology based on the Biot-Savart\'s law and the superposition principle. Analytical studies to verify the influence of installation and electrical parameters of lines on the magnetic field are presented for high voltage underground lines consist of one and two circuits with different types of installation and earthing. Comparisons between analytical and measurement values of magnetic field of existing high voltage underground lines in operation are also addressed in this work. The main mitigation techniques of magnetic field used in high voltage underground lines, such as compensation techniques by loop of cables and shielding by metallic materials, are also presented. Due the electric field outside the insulated cable be practically zero, issues related to the electric field are not addressed in this work. For simplicity, the magnetic field refers to the magnetic flux density in this document.