Dissertations / Theses on the topic 'Submarine cables'

In this thesis, the Mechanical properties of polypropylene yarn of outer protection layer on Submarine High Voltage Cable, twisted around submarine cable,is determined on various conditions at ABB Company. In the first step, tensile tests are done with polypropylene yarn specimens with and without Bitumen at Room temperature. In the second step,tensile tests are done with polypropylene yarn specimens with and without Bitumen and with knotted polypropylene yarn namely: the Fishermen’s knot, the Weaver’s knot, the Square knot and the Overhand knot at Warm Condition (60˚c) and Cold Condition(-5˚c). In the final step,it is proposed to obtain numerical solution using FEM analysis with ABAQUS Software to obtain the hoop stress , the yarn stresses from twisting cable and analyzing of the cylindrical buckling in the buckling torsion and buckling bending on the outer layer of submarine cable with polypropylene material that is mixed with Bitumen.

This thesis, entitled The International Legal Regime Of Submarine Cables: A Global Public Interest Regime, aims to analyze the legal regime governing submarine cables, identify its deficiencies and examine how they might be addressed by international law. The main idea of this research is that modern legal regime of submarine cables is fragmented and incomprehensive and consequently requires substantial and institutional changes. The study consists of three sections: the first section is devoted to the legal nature of submarine cables as an object of regulation; the second section addresses current legal regime of submarine cables on several levels such as public international law, domestic law of states and private international law; the third section, consolidating the analysis made in two previous sections, presents suggestions on how the existing legal regime might be changed to provide better submarine cables governance.
La presente tesis doctoral, que lleva por título El régimen jurídico internacional de los cables submarinos: un régimen de interés público global, tiene como objetivo analizar el régimen jurídico que rige los cables submarinos, identificar sus deficiencias y examinar cómo podrían ser abordados por el derecho internacional. La idea principal de esta investigación es que el régimen jurídico moderno de los cables submarinos es fragmentado e incompleto y, en consecuencia, requiere cambios sustanciales e institucionales. El estudio consta de tres secciones: la primera sección está dedicada a la naturaleza jurídica de los cables submarinos como objeto de regulación; la segunda sección aborda el régimen jurídico actual de los cables submarinos en varios niveles, como el Derecho internacional público, el derecho interno de los Estados y el Derecho internacional privado; la tercera sección, que consolida el análisis realizado en dos secciones anteriores, presenta sugerencias sobre cómo se podría cambiar el régimen jurídico existente para proporcionar una mejor gobernanza de los cables submarinos.
Aquesta tesi, titulada El règim jurídic internacional de cables submarins: un règim d'interès públic global, pretén analitzar el règim jurídic que regula els cables submarins, identificar-ne les deficiències i examinar com poden abordar el dret internacional públic. La idea principal d'aquesta investigació és que el règim jurídic modern dels cables submarins està fragmentat i incomprensiu i, per tant, requereix canvis substancials i institucionals. L’estudi consta de tres seccions: la primera secció està dedicada a la naturalesa jurídica dels cables submarins com a objecte de regulació; la segona secció aborda el règim jurídic actual dels cables submarins a diversos nivells com el dret internacional públic, el dret intern dels estats i el dret internacional privat; la tercera secció, que consolida l’anàlisi feta en dos apartats anteriors, presenta suggeriments sobre com es pot canviar el règim jurídic existent per proporcionar una millor governança dels cables submarins.

The expansion of offshore renewable energy infrastructure and the need for trans-continental shelf power transmission require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 90°C and are typically buried 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the heat flow pattern and potential effects on the sedimentary environments around such anomalously high heat sources in the near surface sediments are poorly understood. Temperature measurements from a 2D laboratory experiment representing a buried submarine HV cable are presented, and the thermal regimes generated within a range of typical unconsolidated shelf sediments - coarse silt, fine sand and very coarse sand are identified. Several experiments were carried out in a large (2 x 2.5 m) tank filled with water-saturated artificial (ballotini - spherical glass beads) and natural sediments (fine marine sand) with a buried heat source and 120 thermocouples to measure the time-dependent 2D temperature distributions. The observed steady state heat flow regimes and normalised radial temperature distributions were compared with outputs from corresponding Finite Element Method (FEM) simulations. The results show that the mechanisms of heat transfer and thus temperature fields generated from submarine HV cables buried within a range of sediments are highly variable. Coarse silts with ~10-13 m2 permeability, are shown to be purely conductive with 10-60 °C radial temperature distribution within 40 cm from a 60°C above ambient source. Fine sands with ~10-11 m2 permeability, demonstrate a transition from conductive to convective heat transfer at c. 20°C above ambient with 10-55 °C asymmetric temperature rise up to 1 m above a 55°C above ambient heat source. Very coarse sands with ~10-9 m2 permeability, exhibit dominantly convective heat transfer even at very low (c. 7°C) operating heat source temperatures and with 10-18 °C significant asymmetric temperature rise of the surrounding sediments over 1 m above an 18 °C heat source. The computed controlling thermal properties demonstrate a distinct variation of thermal diffusivity and conductivity within different sediment types; sandy (fine sands) sediments are about twice more effective at diffusing heat than muddy (coarse silts) sediments. The occurrence of convection heat transfer within high permeability sediments is an important insight that are currently neglected in the existing IEC 60287 standard for current ratings estimation. Significant convection supports more efficient heat transfer leading to reduced cable temperature, increased current ratings and ampacity, decreased degradation rates of cable insulation and thus increased life span and decrease manufacturing costs of submarine cables. Also the varying sediment thermal conductivity around submarine HV cables further implies that cables buried around sandy sediments will uptake heat more rapidly than in muddy sediments, which are also not considered in the existing IEC 60287 standards. In addition, these findings are important for the surrounding near surface environments experiencing such high temperatures and may have significant implications for chemical and physical processes operating at the grain and sub-grain scale as well as biological activity at both micro-faunal and macro-faunal levels.

Offshore wind power is attracting increasing levels of research and investment. The use of HVDC transmission and the development of DC grids are topics with similar high levels of interest that go hand in hand with the development of large scale, far from shore wind farms. Despite increased capital cost of some components, DC power transmission can have significant advantages over AC transmission, in particular in the offshore environment. These advantages are well established for large scale, long distance point to point transmission. This thesis assesses the suitability of a multi-terminal DC power collection network, with short cables and relatively small amounts of power, addresses a number of the technical challenges in realising such a network and shows methods for overall system cost reduction. Technical and modelling challenges result from the interaction between power electronic DC-DC converters and the cables in a DC transmission network. In particular, the propagation of the ripple current in bipole DC transmission cables constructed with a metallic sheath and armour is examined in detail. The finite element method is used to predict the response of the cable to the ripple current produced by the converters. These results are used along with wave propagation theory to demonstrate that cable design plays a crucial role in the behaviour of the DC system. The frequency dependent cable models are then integrated with time domain DC-DC converter models. The work in the thesis is, broadly, in two parts. First, it is demonstrated that care and accuracy are required in modelling the cables in the DC transmission system and appropriate models are implemented and validated. Second, these models are combined with DC-DC converter models and used to demonstrate the practicality of the DC grid, make design recommendations and assess its suitability when compared with alternative approaches (e.g. AC collection and/or transmission).

Dans un contexte de développement rapide des projets d’énergies marines renouvelables, le but de cette thèse était d’améliorer les connaissances sur les impacts potentiels des câbles électriques sous-marins sur les écosystèmes benthiques côtiers. En se focalisant sur la phase de fonctionnement, ce travail était essentiellement dédié à la caractérisation de l’effet récif généré par ces câbles et leurs structures associées (protection, stabilisation) sur les communautés épibenthiques fixées et la mégafaune mobile. L’étude était principalement basée sur l’utilisation d’images sous-marines (photo et vidéo) prises in situ par des plongeurs. Ce travail a mené à des réflexions méthodologiques sur la manière la plus efficace d’analyser ce genre de données afin d’appréhender pleinement la dynamique de colonisation des structures artificielles et leur rôle d’habitat pour des espèces commerciales. Outre cet effet récif, certains organismes se retrouvent exposés à des champs magnétiques émis par les câbles électriques. Ceci m’a conduit à mesurer expérimentalement l’impact de champs magnétiques artificiels sur le comportement du homard Européen (Homarus gammarus) au stade juvénile. Finalement, nous avons étudié in situ les potentiels bénéfices pour la macrofaune benthique de l’exclusion d’activités anthropiques autour de la route de câbles électriques. Le couplage d’approches in situ et ex situ m’a permis de mieux appréhender les impacts environnementaux associés aux câbles électriques sous-marins. Ces résultats permettront d’améliorer l’évaluation de l’empreinte écologique des futurs raccordements électriques
In a global context of rapid development of marine renewable energy projects, the aim of this PhD thesis was to better characterise the potential impacts of submarine power cables on coastal benthic ecosystems. The work specifically focused on the impacts associated with the operational phase. The major part of this work was dedicated to the reef effect created by these cables and their protective and stabilising structures on sessile epibenthic communities and mobile megafauna. This work was mainly based on underwater imagery, either video or photo collected in situ by divers. The challenge of working with underwater imagery has led me to optimise image analyses so as to effectively monitor benthic colonisation and to quantify artificial reef habitat provision to commercial species.In addition to this reef effect, colonising organisms are exposed to magnetic fields generated by the power cables. Thus, I designed an experimental study to assess the impact of realistic magnetic fields on the behaviour of juvenile European lobsters (Homarus gammarus). Finally, we explored the ecological impacts of excluding anthropogenic activity from the cables routes and potential benefits for benthic macrofauna. By coupling both in situ and ex situ approaches, my PhD research better characterises the environmental impacts associated with submarine power cables. These results will help to assess the ecological footprint of future power grid connections

Submarine cable systems are a vital and expanding part of the world wide telecommunication network. The systems are laid in the ocean using a cable ship. During the deployment of a submarine cable, the cable ship has only limited information about the behaviour of the cable once it leaves the vessel and begins its descent to the seabed. The present thesis studies the cable dynamics and control during laying operations.
The cable dynamics is modeled using the continuum approach. Using the model developed, the cable configuration and tension are obtained for the two dimensional steady state and transient motions, when different parameters such as the ship velocity, hydrodynamic constant, and current direction, are varied. Also, the out of plane angle of inclination and corresponding maximum displacement for the three dimensional steady state case are determined.
Then the possibility of controlling the cable oscillations by varying the payout rate is explored. In the case of the controlled response the results show that, in principle, the deviation of the in plane angle can be effectively reduced to zero, but the value of the input payout rate needed is unrealistic in practice.

Pasados los 80’s el incremento en la demanda del ancho de banda por el uso de Internet, así como las comunicaciones internacionales privadas de la industria de las Telecomunicaciones, han ocasionado que las redes basados en Satélites colapsen, ya que esta tecnología no podía brindar la tecnología (ancho de banda) que se necesitaba y otro, su costo es significativamente mayor. Razón por el cual, se inicio el uso de las redes por cable submarino aumentando considerablemente su demanda, hasta que el día la mayoría de las comunicaciones internacionales se hacen a través de este medio. Los grandes cables submarinos en las telecomunicaciones, tiene la misión de unir los continentes entre si a través de los océanos y soportan el 90% del tráfico de la red, trasmitiendo hasta más de 7 Terabits por segundo (Tbps); es decir, más de siete billones de bits cada segundo. El uso de este medio de transmisión tiende a ser vulnerable por el medio ambiente, los daños y el uso inadecuado que se le brinde; es por eso que, la Operación y Mantenimiento de una Red de Cable Submarino es de suma importancia para prevenir y actuar al momento que se presente algún deterioro o rotura, esto es un problema que conlleva perdida económica, por cuanto la rotura de sólo un cable afectaría a millones de usuarios, Para fines de mantenimiento preventivo y correctivo es necesario realizar mediciones y enviar órdenes a los repetidores que están bajo el mar. Esto se realiza variando levemente (sobre-modulando) la señal luminosa de acuerdo a la señal de datos de baja velocidad que contiene los mensajes enviados o recibidos hacia o desde los repetidores.
Tesis

Fibre optic telecommunication cables laid across the seaoor are buried in shallow water depth (<2000m) for protection against hazards arising from commercial shing and shipping activity. The cables are buried in a trench created by a sea plough, often jet assisted and towed from a ship, or by a ROV with jet legs straddling the cable and uidising the soil around it. Recent trends in the industry require more versatile burial tools, so a sound understanding of their fundamental mechanics is required to enable their optimun design and performance. The aim of this research program was to study the mechanics of force reduction on jet assisted cable burial tools. The experimental program consisted of two stages, both conducted in controlled submerged conditions. The rst studied the effects of jet parameters, tool rake angle and pore pressure on tool force reduction. The second stage studied the action of a single horizontal buried jet on the surrounding soil, in which the rst series of experiments studied a static jet nozzle in sand and clay, and the second a dynamic jet nozzle. The flow rate or nozzle Velocity was varied in each respectively. The rst stage showed force reduction was caused by the reduced soil stress on the tool face in areas intersecting uidised sand. The larger the uidised area (FA), or the lower its intersection, the greater the force reduction. Evenly spaced nozzles gave greater FA coverage of the tool face. Interaction between jet and rake angle and force was complex, but upward angled jets and forward raked tools gave least force reduction. Results of the second stage showed cavity formation in sands characterised by shear erosion whereas in clay by pressure fracturing. The cavity size in sands was directly proportional to jet momentum ux and inversely proportional to tool Velocity. Mathematical models were developed from each stage, the rst to simulate tool force reduction created by the jets, given knowledge of the FA, and the second to simulate the FA created by a single jet. The second over predicted cavity length by a average of 7% over the range of tool velocities tested. The combined models over predicted tool force, and suggested reasons for the discrepancies are given. Further research is required to rene the model and provide a useful tool for the design and operation of jet assisted cable burial tools in saturated sands.

Cette thèse de doctorat est composée de trois chapitres traitant de l’impact des innovations technologiques sur les marchés financiers, prenant comme cas d’étude le marché des changes. Le premier chapitre analyse l’impact des innovations technologiques sur la géographie du marché des changes. Il utilise la connexion des pays au réseau sous-marin des câbles à fibre optique comme mesure de choc technologique exogène. Les estimations montrent que l’introduction des câbles à fibre optique a contribué à concentrer la répartition des activités de trading dans quelques grandes places financières au détriment de toutes les autres. Le deuxième chapitre s’intéresse à l’impact de la technologie sur la réaction des marchés des changes à de nouvelles informations macroéconomiques et financières. Il estime que le développement des technologies de l’information et de la communication permet de réduire la volatilité sur les marchés des changes de façon significative. Enfin, le troisième chapitre montre que le trading à grande vitesse contribue à atténuer les réactions de marché aux chocs macroéconomiques exogènes. Une explication possible, qui s’appuie sur un modèle théorique, est que le trading à grande vitesse augmente la dispersion des cotations de change, qui en retour accroît le temps nécessaire pour les traders pour traiter l’information contenue dans les cotations, rendant de fait le marché moins réactif à de nouvelles informations macroéconomiques et financières. Cette thèse de doctorat propose une nouvelle façon de penser et de mesurer l’impact du progrès technologique sur les marchés financiers. La première contribution est d’utiliser le réseau sous-marin des câbles à fibre optique comme choc technologique exogène et de mesurer son impact sur la géographie des marchés des changes et la volatilité. La seconde contribution est de montrer le lien entre trading à grande vitesse, dispersion des cotations et efficience des marchés, en utilisant l’entropie des cotations comme mesure du temps nécessaire pour traiter l’information contenue dans les prix et en comprendre l’impact sur l’efficience de marché
This PhD dissertation is a collection of three essays on how technology has been shaping financial markets, using as a case study the foreign exchange market. The first chapter investigates the impact of technological innovations on the geography of the foreign exchange market. It uses as a proxy for exogeneous technological changes the connection of countries to submarine fiber-optic cables. The estimates of this chapter suggest that technology contributes to concentrating foreign exchange trading in an handful of financial centers. The second chapter studies the impact of technology on the reaction of foreign exchange markets to macroeconomic announcements. It shows that the development of Information and Communication Technologies dampens foreign exchange markets volatility. Finally, the third chapter shows that fast trading dampens market reaction to new macroeconomic information. One possible explanation, based on a theoretical model, is that fast traders increase the dispersion in exchange rate quotes, i.e. the time traders need to process new information about market prices; in turn, entropy dampens the market’s reaction to macro news. This PhD dissertation provides a new way to measure and conceptualize technological progress with regards to financial markets. The first contribution is to treat the network of submarine fiber optic cables as an exogenous technological shock to investigate the impact of technology on the geography of foreign exchange trading and on volatility. The second contribution is to show that patterns in the distribution of quotes matters in the context of fast trading. The concept of entropy in exchange rate quotes is used to characterize how fast information diffuses on financial markets and thereby to assess the implications of fast trading on market efficiency

Les élasmobranches jouent un rôle important dans les réseaux trophiques marins, mais leurs populations sont en déclin à l'échelle mondiale et souvent négligées face aux perturbations anthropiques. Le développement rapide des parcs éoliens offshores interroge sur l'impact de ces structures sur les espèces marines. À cette fin, le début de cette thèse a consisté à faire le point sur l'état actuel des connaissances des effets potentiels des parcs éoliens offshores sur la biologie et l'écologie des élasmobranches et d'identifier les principales lacunes. Malgré un manque important de données de référence sur ces espèces, la synthèse a démontré que plusieurs pressions pourraient potentiellement avoir des effets à différentes échelles spatiales. Par exemple, à large échelle, l'installation d'un parc éolien peut affecter la connectivité de ces espèces, tandis qu'à plus fine échelle, les émissions de champs électromagnétiques des câbles sous-marins peuvent provoquer des changements comportementaux à quelques mètres autour de la source. La télémétrie acoustique apparaît comme un outil pertinent pour combler les lacunes dans les connaissances sur l'utilisation spatio-temporelle et les déplacements des individus dans leur environnement et sur la façon dont ces comportements sont influencés par les activités anthropiques.Le positionnement à fine échelle d'individus à l'aide de la télémétrie acoustique est une approche prometteuse pour étudier le comportement des espèces marines. Cependant, la précision des modèles de positionnement actuels reste un défi important, en particulier dans les environnements marins avec une bathymétrie importante. Cette thèse a développé et amélioré la précision d'une méthode de positionnement à fine échelle pour analyser le comportement individuel à une échelle métrique dans des environnements offshores. Les travaux illustrent également l'importance de la précision des paramètres de terrain mesurés pour assurer des performances élevées des modèles de positionnement.La télémétrie acoustique passive multilatérale a été utilisée pour suivre in situ les patrons comportementaux de deux espèces d'élasmobranches benthiques, la petite roussette Scyliorhinus canicula et la raie brunette Raja undulata autour d'un câble d'exportation d'un parc éolien offshore. Les résultats ont suggéré une présence plus élevée des individus lors de la mise en tension des câbles. L'application de modèles de mouvement de Markov Cachés (HMM) a permis d'identifier deux à trois états comportementaux des individus dans la zone d'étude, avec un comportement principalement dominant qui pourrait être associé à la recherche de nourriture. L'ensemble des résultats fournit des informations précieuses en tant que première étude in situ sur les interactions de ces espèces avec les câbles sous-marins d'un parc éolien offshore, pouvant servir de référence.Enfin, cette thèse a également examiné l'utilisation spatio-temporelle de S. canicula au sein du premier parc éolien offshore français opérationnels. Dans cette étude, plus de 30 individus ont été marqués et suivis sur une période de 10 mois au sein du parc. Les résultats ont montré que le parc éolien ne semblait pas repousser les individus marqués avec une fidélité à l'habitat et une résidence saisonnière des individus. Bien que des individus aient été présents dans l'ensemble du parc éolien, les monopieux installés sur des substrats sablonneux et équipés d'une protection contre l'affouillement ont montré une occurrence significativement plus élevée.Cette thèse a fourni de nouvelles informations sur des aspects clés de l'écologie des élasmobranches benthiques et sur la façon dont ils interagissent avec les structures des parcs éoliens offshores. Elle souligne la pertinence de l'utilisation de la télémétrie acoustique à plusieurs échelles spatiales et apporte de nouvelles perspectives à l'étude des effets des parcs éoliens offshores in situ sur les élasmobranches
Elasmobranchs play an important role in marine food webs, but their populations are globally declining and often overlooked in the face of anthropogenic disturbances. The rapid development of offshore wind farms (OWFs) raises questions about their impacts on these species. To this end, the beginning of this work consisted in reviewing the current state of knowledge on the potential effects of these structures on the biology and ecology of these species and identifying key research gaps. Despite important lack of baseline data on these species, the synthesis demonstrated that several pressures could potentially cause effects at different spatial scales for these species. For example, on a large scale, the installation of an OWF may affect connectivity during species movements, while electromagnetic field emissions generated by submarine cables may cause behavioural changes within a few metres around the source. Acoustic telemetry appears as a relevant tool to address knowledge gaps on space use, occupation patterns and movements of free-swimming individuals within their natural environment and how those behaviours are influenced by anthropogenic activities.Fine-scale positioning of acoustically tracked individuals is a promising approach, increasingly used to study the natural behaviour of target species and the impact of anthropogenic activities. However, the accuracy of current positioning models remains a significant challenge, especially in open marine environments, and is an evolving field of study using passive acoustic telemetry. This thesis developed and improved the accuracy of a fine-scale positioning method to analyse individual behaviour at a metric scale in offshore open environments. The work also illustrates the importance of precision in measured field parameters to ensure high performance of positioning models.Multilateral passive acoustic telemetry was used in this thesis to monitor in situ the occupancy patterns of two benthic elasmobranch species, the small spotted dogfish Scyliorhinus canicula and the undulate ray Raja undulata, within an area with a dense array of receivers around an OWF export cable. Using a fine-scale positioning model, results suggested a higher presence during cable tensioning. The application of Hidden-Markov Chain movement models allowed the identification of two to three behavioural states within the study area, with a predominantly dominant behaviour that could be associated with foraging. The results have identified various metrics to qualify the behaviour of these two species, including vertical movements in the water column observed in S. canicula. The overall results provide valuable information as the first in situ study on the interactions of these species with the submarine cables of an OWF, which can serve as a reference.Last, the current study also examined the occurrence and occupancy patterns of the small spotted dogfish at a larger spatial scale, across different habitat types within the first operational French OWFs. A field study was conducted to acoustically track over 30 individuals for over 10 months at the Saint Nazaire OWF. The results showed that the OWF did not appear to repulse tagged individuals, that displayed habitat fidelity with seasonal residency of individuals. Although individuals were present throughout the OWF, monopiles installed on sandy substrates and equipped with scour protection showed a significantly higher occurrence.The current study has provided new insights into key aspects of the ecology of benthic elasmobranchs and how they interact with OWF structures. This thesis underscores the relevance of using acoustic telemetry at multiple spatial scales and brings new perspectives to the study of effects of OWFs in natura on free-swimming elasmobranch

En el presente trabajo se diseñó un prototipo de brazo robótica háptico teleoperado de 4 grados de libertad para la exploración marina hasta una profundidad máxima de 500m. Se diseñó el brazo robótica esclavo en un software de diseño, se analizó la estática y dinámica de dicho robot y se realizaron análisis de esfuerzos en los principales componentes. El robot tendrá un alcance máximo de 900mm y contará con sensores de posicionamiento y fuerza para el control de posición y fuerza. Además el brazo robótico contará con una cámara cerca al efector final con el motivo de tener una mejor visión para el operador. El trabajo incluye también el diseño del manipulador maestro que será controlado por el operador y que incluirá una realimentación de fuerza (force feedback). Se escogieron los motores y controladores indicados para el correcto funcionamiento del robot así como el tipo de comunicación que tendrá el robot con el computador. En el primer capítulo se presentará la problemática actual de los manipuladores robóticos submarinos, los cuales en su mayoría son hidráulicos y el costo de operación de dichos robots son altos. En el segundo capítulo se mencionarán los requerimientos físicos-mecánicos, requerimientos electrónicos y requerimientos de control del robot. Además se presentará el concepto de solución del sistema mecatrónico que será una alternativa de solución a la problemática presentada. En el tercer capítulo presentará el sistema mecatrónico completo. Se explicará el diagrama de funcionamiento del sistema mecatrónico, los sensores y actuadores presentes en el trabajo, planos de ensamble de los manipuladores, diagramas de circuitos y el diagrama de control del sistema mecatrónico. En el cuarto capítulo se presentará el presupuesto total del proyecto, el cual incluirá el presupuesto de los componentes mecánicos y electrónicos. Por último en el quinto capítulo se presentarán las conclusiones obtenidas del proyecto.
Tesis

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2016.
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A modelagem analítica de um sistema de cabos tripolares é um grande desafio devido à configuração não concêntrica dos elementos envolvidos. Por causa dessa limitação, uma modelagem numérica do cabo com o método de elementos finitos em 2D é desenvolvida no intuito de obter os valores da impedância série e da admitância paralela. Para o cálculo da impedância série, usou-se a formulação magnetodinâmica em potencial vetor magnético no domínio da frequência, e para o cálculo da admitância paralela utilizou-se a formulação quase-estática de campo elétrico em potencial escalar elétrico no domínio da frequência. A metodologia é aplicada em cabos encontrados em catálogos de fabricantes. Os resultados numéricos para cada fase são comparados com os resultados analíticos e com valores fornecidos pelo fabricante. Além disso, os resultados numéricos foram validados por meio de comparações com resultados de medições realizadas em um cabo submarino disponível na UFSC.

Abstract : The analytical modeling a three-core cable system is challenging because of non-concentric configuration of the elements involved. Due to this limitation, a numerical modeling of cable with 2D finite element is developed in order to obtain the values of the series impedance and the parallel admittance. The series impedance is calculated using the frequency domain magnetodynamic formulation in magnetic vector potential and, the parallel admittance is obtained using the frequency domain quasi-static formulation of electric field in electric scalar potential. The methodology is applied in cables found in manufacturers catalogs. The numerical results for each phase are compared with the analytical results and with values provided by the manufacturer. Moreover, the numerical results are validated by comparison with measurement results performed in a submarine cable available at UFSC.

Les câbles sont utilisés de plus en plus pour le transport et la distribution de l'électricité en courant alternatif sur des distances de plus en plus longues. La prolifération de fermes éoliennes offshore qui nécessitent d'interconnexions avec le continent a aussi propulsé leur utilisation sous-marine. Modèles de câbles sont disponibles dans le bien connu logiciel Electro Magnetic Transient Program et sont destinés au domaine temporel. Ces modèles sont assemblés en utilisant différentes techniques, mais tous nécessitent une connaissance précise des paramètres des câbles dans le domaine fréquentiel. Dans ce but, pour le calcul des impédances des câbles tripolaires cette thèse propose une méthode qui améliore la prise en compte de la proximité entre tous les conducteurs : il s'agit d'une méthode semi-analytique qui utilise le concept duale de fils minces et sous-conducteurs pour décrire la densité de courant à l'intérieur des conducteurs et le calcul des impédances. L'effet du retour par la mer est aussi analysé et une méthode quasi Monte Carlo est proposé, afin de résoudre les intégrales qui décrivent la formulation des impédances pour le sol à deux couches (la mer et son fond) sur lequel ces câbles sont posés. L'effet du à la présence des couches de semi-conducteur dans les câbles est aussi traité. La méthode de collocation stochastique est aussi décrite et appliquée, afin de prendre en compte la variabilité des paramètres d'entrée.

Actualmente, las redes de fibra óptica submarinas y terrestres se han desplegado rápidamente alrededor del mundo, debido a que las inversiones y el tráfico a nivel de los usuarios se ha incrementado a gran magnitud. Esto hace que se tenga que hacer un análisis del espectro adecuado, para aprovechar adecuadamente los recursos y el mantenimiento sea viable a nivel económico. El mantenimiento de un sistema de fibra óptica dependerá de su topología, número de fibras, estaciones, PoPs, repetidores, monitoreo, etc. Todo esto es asumido por el proveedor del servicio, pero cuando estamos hablando de un consorcio, el mantenimiento tendrá que ser dividido equitativamente entre sus miembros. En un consorcio de un sistema de fibra óptica, cuando sus miembros hacen crecer su tráfico por igual, el mantenimiento es dividido equitativamente, pero cuando los miembros no crecen con la misma rapidez, esto genera un problema en la división del mantenimiento. Este es el caso del Consorcio PCCS, conformado por Cable Andino, SETAR, TELXIUS, UTS y C&W. Por lo cual, en la presente investigación se propone aplicar el uso del método del espectro como nueva metodología para el Consorcio PCCS permite reducir los costos del mantenimiento y mejorar el cálculo en la expansión y optimización de los servicios.

Orientador : Jose Antenor Pomilio
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-07-29T01:41:03Z (GMT). No. of bitstreams: 1 Vendrusculo_EdsonAdriano_D.pdf: 10711581 bytes, checksum: d6ada702601d4c784855dd27a0b04cef (MD5) Previous issue date: 2001
Resumo: A eliminação de sobretensões em sistemas de extração de petróleo é o principal objetivo deste trabalho. Tais sistemas usualmente demandam pelo uso de cabos longos para conectar uma bomba elétrica submersível a sua fonte de alimentação. Um inversor tipo fonte de tensão operando com modulação por largura de pulso é utilizado como fonte e um motor de indução convencional sintetiza a bomba elétrica na modelagem do sistema. A eliminação das sobretensões é alcançada empregando uma estratégia que visa a alteração da freqüência de chaveamento do inversor, durante o funcionamento do sistema, ou seja, on-line. O valor adequado para a freqüência de chaveamento é calculado fazendo o tratamento digital de amostras do sinal de corrente na saída do inversor. A rotina de processamento pode ser implementada num processador tipo DSP. A análise pode ser estendida para sistemas de acionamento de motores de indução industriais desde que o comprimento do cabo seja suficientemente longo. A influência do efeito pelicular nos condutores é considerada na modelagem do cabo. Os parâmetros elétricos do cabo são calculados on-line através de uma metodologia chamada técnica da freqüência natural. Tais parâmetros permitem obter a resposta em freqüência do sistema e, portanto, identificar as frequências críticas onde existem ressonâncias que, por sua vez, submetem o motor à sobretensões e causam sobrecorrentes no inversor. São apresentados resultados de simulação para sistemas com motores da ordem de centenas de cavalos e resultados experimentais para um sistema com cabo de lkm de comprimento. Sistemas que aplicam transformadores elevadores de tensão na saída do inversor também são alvo deste trabalho
Abstract: The analysis of long distance induction motor driving systems is performed. This kind of system, usuaIly driven by a voltage source inverter, has been employed by Petrobras for oi! exploitation in deepwater. Due to the excessive cable length, undesirable effects such as overvoltages and overcurrents are recorded at the motor and the inverter, respectively. Passive filters are commonly used in order to overcome those effects. An alternative strategy based on the correct choice of the inverter switching frequency, set in a pulse width modulation, is proposed. The strategy raise interesting from fact ofnot demanding for additional elements. The switching frequency is set even in the running system and can be estimated through the digital processing of the signal current sampled at the inverter terminaIs. A mathematical toei caIled natural frequency technique is employed to estimate the electrical parameters of the cable, in such a way that system frequency response can be outlined. An assessment of the critical frequencies related to overvoltages is possible from the frequency response. A high power system was simulated taking into account the skin effect in the cable conductors and a low power prototype was built in a laboratory. The closing results aIlow the application of the same strategy to industrial plants, since enough long cables are employed. Systems demanding for a voltage step-up transformer are also covered in the work
Doutorado
Energia Eletrica
Doutor em Engenharia Elétrica

Face à la demande croissante en bande passante Internet, disposer de systèmes de communication optique robustes est plus crucial que jamais.Au-delà des avancées dans les technologies et composants individuels, la performance du système de communication dépend également de la façon dont ces composants sont utilisés et combinés pour que la configuration globale soit optimisée. Souvent, la performance du réseau est limitée par les prédictions qu’on peut en faire avant que le réseau soit déployé.Cela rend la précision de notre prédiction de performance essentielle pour l’optimisation du réseau. L’objectif de cette thèse est de caractériser et de contrôler les principales sources de distorsion du signal optique dans les liaisons sous-marines, principalement pour prédire la performance future du réseau avec des marges minimales. Nous avons concentré notre étude sur deux distorsions physiques : les effets non linéaires de Kerr et les pertes dépendantes de la polarisation. Cette thèse aborde les défis liés a l’estimation de la performance et au contrôle du réseau afin de proposer de nouveaux outils de surveillance et des lignes directrices pour optimiser les systèmes de transmission
With the growing demand for internet bandwidth, having robust optical communication systems is more crucial than ever. Beyond the advances in individual technologies and components, the performance of the communication system also depends on how intelligently these components are used and combined so that the overall configuration is optimized. Often, network performance is limited by predeployment predictions, making accurate estimation essential for optimization. The objective of this thesis is to characterize and monitor key sources of distortion in subsea links, primarily to predict the network’s future performance with minimal margins. We focused on two physical impairments: nonlinear Kerr effects and polarizationdependent loss. The thesis addresses the challenges of performance estimation and network monitoring to introduce novel monitoring tools and provide guidelines for optimizing transmission systems

The main objective of this thesis is to develop a new methodology to evaluate the transmission cable losses of wind-generated electricity. The research included the power loss variations of submarine cables in relation to the line length, cable capacity and the transmission technology in an offshore wind farm having a capacity of 500 MW. The literature of similar studies helped to generate a solid background for the research.   The comprehensive analysis carried out is based on a hypothetical wind farm and using three different power transmission wind farm models to investigate the technical reliability of transmission technology, namely, High Voltage Alternative Current (HVAC), High Voltage Direct Current Voltage Source Converter (HVDC VSC) and High Voltage Direct Current Line Commutated Converter (HVDC LCC). The analyses carried out are performed under assumptions and simplifications of power system models to evaluate the submarine cable transmission losses of 3 different transmission systems by using the MATLAB/ Simulink software.   With relevance to the simulation results, the HVAC submarine cable has more losses than any other transmission technology cables and it is suitable for short distance power transmission. The VSC technology has less losses than HVAC. Comparing with afore-mention technologies the HVDC LCC technology transmission links have the lowest line losses. Moreover, the transformer losses and the converter losses were calculated. The simulation results also included the overall power system losses by each of the transmission models.

An optimization methodology, algorithms, and computer program for cable/lumped-body deployment system are developed for the design and installation of sonar packages in deep ocean ranges. In addition, a methodology and algorithms for the control of the system are proposed. A penalty function is developed in terms of the system parameters and the dynamic constraints are set up for the optimization of cable/lumped-body deployment system. Deployment procedures and segmentations characterized by their initial and terminal condition are proposed. Alternating Direction (ADM) and Modified Alternating Direction (MADM) methods are employed for the optimum search. The optimization algorithms are then implemented on a desk-top computer. The objective of the search is to achieve the optimum vessel speed and cable pay-out rate that result in the minimum penalty value. Numerical examples are presented to test the robustness of the algorithm (ADM) and the compute program capabilities. The results are compared to those of the MADM method and the entire space search. During actual installation, it is anticipated that randomness in the excitation will cause sonar packages to miss the exact target locations. Thus a continuous correction in the controllable parameters is necessary. Three alternative types of control algorithms are presented for these reasons.
Graduation date 1993

碩士
中原大學
電機工程研究所
94
Peng-Hu is an isolated power system without having any links with Taiwan. There is only a Gen-San power plant with 12 diesel generators located in the main island. According to the load increasing, Peng-Hu power system need to build new plants, including diesel generator, wind power generator, offshore wind farm, and submarine cables that connect Peng-Hu power system with Taiwan. By the possibility of set up the new plants, that could have nice situations. After generators and submarine cables incorporating into the power system, it caused impacts in all respects. So this study considered evaluating every phenomenon, such as voltage fluctuation, voltage flicker, harmonic, safety of system, transient stability, underfrequency load shedding and overfrequency generator tripping. For discussing the Peng-Hu power system’s transient stability, this study established the exciter and governor’s mathematic model of the diesel and wind generator. Because of wind couldn’t be forecasted, the large-scale offshore wind farm caused voltage flicker in the power system. This study considered nine system situations in 2011. It used PowerWorld Simulator to study the power flow and fault current, and using PSCAD/EMTDC to study voltage flicker and transient stability. By the strategy of the special protection system, planning the underfrequency load shedding and overfrequency generator tripping. Certain of the advantageous results toward building the every new plant are also provided in this paper.

碩士
國立臺北科技大學
電機工程系所
102
This thesis is to study the protection zone planning of distance relays for long submarine cables of large offshore wind farm. A case study based on Tai-Peng submarine cables of Peng-Hu offshore wind farm with type-C double-fed induction wind generators is presented. A software package namely PSS/E is used for the modeling and simulation. Three protection zones are defined for submarine cable distance relays and the three phase short circuit (3ΦSC) fault characteristics of different protection zones are simulated under different wind farm operation situations. The availabilities of distance relays are surveyed including to find the defects of conventional planning and to proposed improved planning of protection zones. The study results show that the conventional quadrilateral distance relay can not provide sufficient protection for long submarine cables because of neglecting the effects of cable capacitances and the variations of wind farm operation. Therefore, a novel quadrilateral protection zone for distance relay is panned considering the effects of cable capacitances and the variations of wind farm operation. The availabilities of proposed planning had been certified by PSS/E simulation, which is also a good reference for the planning of long cable protection coordination.

Submarine power production installations use the power of the ocean to generate renewable energy for the population to use. To bring this electricity back to land, use of electrical cables is required. The choice of cable will affect both the quality of received power and the security of the transmission line. To find the inductance and capacitance of these submarine transmission lines, a study of the electric and magnetic fields that are produced due to the power flow on these cables must be performed. The armor that is used to protect the cable from underwater hazards is significant in determining the cable losses and finding the equivalent inductance and capacitance. Finding the inductance and capacitance of the submarine cable will allow for the determination of the two port parameters of the cable. These parameters will allow for the analysis of the transient and steady state performance of the cable.

碩士
國立臺灣大學
海洋研究所
100
Since 2006, southern Taiwan has been through several big typhoons and earthquakes which triggered submarine landslides and turbidity currents and damaged many submarine cables off southwestern Taiwan. In this study, we integrate the results of sub-bottom profiles, sedimentological analysis, hydrological data, and time series of cable breakages to find how the natural hazards (e.g. typhoon and earthquake) caused submarine cable failures. Off southwestern Taiwan, two major submarine canyons, the Gaoping Submarine Canyon (GPSC) and Fangliao Submarine Canyon (FLSC), are incising from continental shelf to deep sea floor and both of them transport considerable amounts of sediment to the South China Sea. GPSC is directly connected to the Gaoping River on land. During the flooding event, hyperpycnal flows following the GPSC down to deep sea. In contrast, the FLSC, which is smaller, younger and confined to the slope, does not associate with any river on land. The source of sediments might directly from the Central Mountain Range. Torrential rains induced landslides delivered large amount of slate fragments through narrow Gaoping shelf into the deep sea. From sub-bottom profiles, the liquefaction structures and chaotic deposits are widely spread off southwestern Taiwan. In such unstable geological and hydrological setting, the submarine landslides can be easily triggered by earthquake or extreme flooding. According to time series of cable breakages in 2006 Pingtung Earthquake, we suggests that a series of aftershocks or sea floor sediment liquefactions might induced submarine landslides and sediment gravity flows. In 2009 typhoon Morakot, torrential rain induced hyperpycnal flow in GPSC may broke submarine cables at the junction of iv upper and middle reaches. During typhoon period, the groundwater levels raised in Pingtung Plain. The increased groundwater pressure might lead to high flux of submarine groundwater discharge and induced liquefaction on seafloor which could triggered submarine landslides and damaged submarine cables. Most of the broken cable sites are along the GPSC and FLSC axis, indicating that canyon might be the major transport path of sediment. Cores collected from the GPSC and FLSC have observed turbidites、wood fragments and broken shells. It shows that sediments are transported rapidly through the submarine canyons. The total 210 Pb activity profiles in cores collected from Gaoping intraslope basin III show an exponential decrease with depths, which suggests there is no severe sediment-laden flow pass through in the past 10 decades. Coarse slate fragments are widely distributed along the FLSC. In contrast, we do not find any coarse grain sediment in the middle reach of GPSC. Our finding suggests that the deep sea coarse slates might be generated from the FLSC.

碩士
國立臺灣大學
工業工程學研究所
104
In the past manufacturers of integrated systems have come up against the challenge of segmented bidding on projects mostly involving large-scale and highly complex components. This study analyzes how to apply a new win-win strategy that will identify the most appropriate partners to participate in a bid team. It follows up by using decision tree analysis to determine the best competitors as far as price goes in seeking to win a tender. Finally, it looks at an actual case regarding submarine cable in which the author was involved, as an example for various manufacturers to learn from when organizing a tender offer. 　　Since various manufacturers participating in a multiple-partner tender bid must all meet the qualifications listed in the customer specifications and must also cooperate in order to make the largest concessions possible on price, they all need to develop a common strategy to put together an offer that will win the tender. Bids on large-scale projects generally involve segmented participation, in many cases simply to weed out speculative bidders. Many different kinds of products are needed in such projects, and integrated systems manufacturers participating in such competitions must seek out suppliers who can work well with each other. Conversely, the various smaller suppliers are looking for systems integrators who can put together winning bids. This process leads naturally to internal competition and complex relationships that are also an important part of the strategy for winning tenders. 　　Chapter One of this study looks at the background of system integrators. Chapter Two follows with an overview of the theory of competition, win-win negotiation strategies and decision trees; while Chapter Three explains some of the key rules followed in making segmented tenders; and Chapter Four analyzes a number of strategies used in competing for bids. In the case involving submarine cable, for example, an empirical analysis of the strategies described above eventually comes to the conclusion described in Chapter Five: system integrators currently working in Taiwan need to find the most suitable partners available to compete in tenders, and they must utilize a combination of strategies rather than attempting to win a tender simply by submitting the lowest bid. Relying on price alone makes it very difficult for a company to manage a profit; what is needed is experience in participating in tenders as well as skill in analyzing and integrating data in order to survive in the game of bids and tenders. 　　Finally, various systems integrators need to think about how to make the best use of existing resources and other providers to beef up their odds of winning in a standard bid process. They must also consider which team of manufacturers will be best for their own interests if indeed they do win the tender. Thus the following research is offered as a guide for manufacturers participating in future tenders, to find the best strategy and increase the company’s success rate in competing in tenders.

碩士
國立中山大學
海洋環境及工程學系研究所
107
In response to the global emphasis and development of renewable energy, solar power, and wind power generation have become the future trend under the promotion of governments. The Energy Bureau of the Ministry of Economic Affairs plans to promulgate an energy policy to set up thousands of offshore wind turbines. Offshore wind turbines are bound to require submarine cables as a transmission medium for electricity, connecting offshore wind farms and onshore substations. The submarine environment is complex, and improper laying of submarine cables and man-made damage may pose a considerable threat to the safe operation of submarine cables. While the submarine cable is mechanically damaged, it usually produces axial force, which is one of the main causes of damage to the submarine cable. The structure of the submarine cable is complex, consisting of the spiral armor and other functional components such as sheath, insulation, and conductor. The spiral armor also generates a torsion moment in addition to the axial elongation when subjected to a tensile load. However, the cable is also twisted during shipping and installation. Therefore, in addition to analyzing the tensile force, the analysis of the torque is also very important. In order to prevent the occurrence of damage, it is necessary to analyze the tensile and torsional mechanical processes of the submarine cable. This study is divided into two types, one of which is to investigate the mechanical behavior of submarine cables under tension and torsion. The structural analysis was carried out with the static analysis software ANSYS-STATIC STRUCTURAL, and the stiffness of the cable would be verified by the tensile and torsional properties. The second is the design analysis of the armor and the core of cable. According to theoretical analysis, the main parameters affecting cable stiffness are the spiral angle and diameter of the armor. This study will investigate the change in cross-sectional properties when the angle and diameter of the armor are varied. Moreover, the number of armor layers and the number of conductors will also be changed to explore the advantages and disadvantages. Meanwhile, the effect of water pressure on the tensile force and torsional moment of the cable will be studied.

碩士
國立成功大學
電機工程學系
103
The thesis aims to study the distance relay protection setting for the long-distance submarine cable. A case study based on the double-curcuit submarine cable linking Taiwan grid and Penghu renewable energy system is demonstrated. The power system simulation package PSS/E is utilized for system modeling and simulation analysis. The protection zones for the distance relay installed on the submarine cable is defined, also, the relay operating characteristic and associated system responses as a three phase ground fault occusr on the submarine cable in different protection zones are simulated. The feasibility of distance relay is also investigated. The research results reveal that the typical mho type distance relay can not offer a complete protection effect for the sake of ignoring the line-to-ground capacitance effect of long-distance submarine cale. Accordingly, a modified mho type distance relay taking the effect of cable capacitance into account is proposed, and it can be verified from the PSS/E simulation that the planning can provide a more complete protection in comparison with the typical one as fault occurs on the cable. The research can provide a reference for the planning of protection for long-distance submarine cable in the future.

博士
國立臺灣大學
工程科學及海洋工程學研究所
103
This study proposes an automated method for submarine cable route design from sonar scanlines collected by an autonomous underwater vehicle (AUV). Traditionally, the route design is carrying out by experienced surveyors and engineers using seafloor survey data. In the work, an automated classification and route planning method using real time data gathered by an AUV is developed to improve the efficiency for submarine cable construction. Firstly, to improve the accuracy of AUV localization, a linear time-varying equation is applied to describe the motion of an AUV that enables the utilization of observability analysis for maneuvering accuracy. Observability is a property in linear system which related to the initial state and the system outputs. An observability-based maneuvering planner is proposed to enhance the vehicle state estimation. Simulation results demonstrated that unobservable modes can be controlled through maneuvering and will affect the accuracy of vehicle state estimaton. Secondly, a novel idea using sonar scanlines and grid-based maps is introduced to map the seafloor for classification. A probabilistic classifier based on Bayes'' theorem and Naïve assumption is applied to distinguish the types of seafloor. A node map is constructed by probabilistic roadmap and then an A-star algorithm is applied to determine appropriate cable routes on a corridor from the node map. Seafloor classification, bathymetry, steep slope, angle of alter course, and cable length are five factors of the A-star algorithm. A field result of a case of the cable route survey between islands was demonstrated. The planned route using the proposed method is close in range to the one recommend by experts. The proposed cable route design method costs less to the one performed by experienced engineers, and therefore is advantageous for the budget saving of the submarine construction.

碩士
國立臺北科技大學
電機工程系研究所
102
Taiwan Power Company is building Taiwan - Penghu 161kV submarine cable project plan (hereinafter referred to Taiwan, Penghu submarine) in 2005,and take up the task of conveying Penghu’s renewable energy, while addressing the future of renewable energy island of Penghu carbon accounted for more than 55% of the energy development restrictions. Taipower company assessment report of Taiwan to Penghusubmarine note that thesea route is divided into northern and southern loops, a length of about 58.8 km, and have to use single core cross- linked polyethylene (XLPE) 630 mm2 submarine cables. Taiwan-Penghu submarine cable project Unified outsourcing procurement case in 2011/11/30 award by J-Power Systems Corporation and Sumitomo Corporation (hereinafter referred to as the JPS / SC) joint contract undersea cable line design,manufacture and installation, JPS / SC completed "submarine cable detailing technical information - submarine cable transmission capacity calculations" in May at 2013, and sent for review, the calculation book content using a combination of IEC-60287 specifications and JCS-0501 specification to derive power transmission capacity. This study focused mainly on IEC-60287 specification projections Taiwan-Penghu submarine powe transmission capacity, thereby identify differences projections expressions and calculations, the proven results of both submarine power transmission capacity is insignificant, However, if the future Taiwan power company want to plan new submarine cable solutions, for different terrain environments waters, the recommend in this study about what factors should consider, other factors can not be taken into account, is to provide design personnel in assessing the capacity of submarine cable transmission element of choice for more information.

碩士
國立交通大學
經營管理研究所
93
ABSTRACT Taking the advantage of submarine cable market deregulation in 2000, Asia Global Crossing obtained the first grant of cable landing license to land and operate a private fiber-optic cable system in Taiwan. The serious impact on Taiwan international bandwidth market was caused by AGC when AGC won a competitive bid over the other players to provide the capacity of TANet's international Internet connectivity between Taiwan and the USA. In addition to the existing IPLC (International Private Leased Circuit), a new product IRU(indefeasible right of use) was introduced to meet the demand for international bandwidth service and the sale of capacity in the form of IRU seems to be the best method to generate cash revenue for private cable operators. The international bandwidth market in Taiwan is undergoing major change following the private cable landing, especially for the regional incumbents. The supply of submarine bandwidth has grown spectacularly over the past four years but the demand for international bandwidth continued to lag owing to the after Internet bubble. The surge of new submarine capacity had a particularly strong effect on capacity prices which have dropped at a breathtaking rate on international routes. The STM-1 lease prices have fallen by more than 80 percent since mid-year 2000. Under the prices tumbling circumstances, the issue whether the IRU, compared with IPLC, is the right choice for international bandwidth operators has become the focus of this research. In this research we present a new methodology of lease versus purchase decision. In the view of the international bandwidth market with dynamic demand, this research applies the method of dynamic programming to compare the accumulated cost caused by IPLC and IRU and to find out, in terms of the minimum cost and lowest risk of acquisition of the international bandwidth, the better bandwidth acquisition solution. The application of real option on investment decisions is also introduced to realize the possibility of improving sales terms and conditions for the buyer’s market. Those improvements are such as the use of protective option and reduction of O&M cost. Finally, this research proposes the suggestions and recommendations for purchasing IRU to international bandwidth operators.

碩士
國立臺北科技大學
電機工程系所
98
The Penghu area in Taiwan boasts one of the world’s richest wind resources. Taiwan Power Co., Ltd. (Taipower) is planning to build a large-scale offshore wind farm in Penghu after the Taiwan-Penghu submarine cable system is completed in the future. As the rise in the wind farm’s capacity is bound to trigger corresponding increase in its influence on the power system, assessing the mutual impacts between the wind farm and the power system has become a highly crucial issue in large-scale wind farm planning. The thesis, adopting PSS/E as the analysis software, finds its study subject in the Taipower system to which the Penghu offshore wind farm will be connected in 2015 after the completion of the Taiwan-Penghu submarine cable system. The large-scale offshore wind farm is assumed to sustain a capacity of 200MW and use double-fed induction generator (Capacity of 3.6MW) as the wind turbine. In addition to meeting the off-peak and peak loads (47.2MW and 89.2MW respectively) of Penghu, the wind farm can be expected to generate extra active power for transmission back to Taiwan through the submarine cable system. The first part of this thesis aims at analyzing the steady- and transient-state features in various scenarios after the large-scale offshore wind farm is connected into the power system so as to ensure reliable power supply between the Taiwan and Penghu power systems connected by submarine cables. Major features under analysis include: power flow, PCC (Point of Common Coupling) voltage variation, fault current, wind farm cut out, location of the fault that causes the tripping of the offshore wind farm, islanding operation of the Penghu power system, system transient stability and critical clearing time. The second part of this thesis aims at developing a variety of strategies to minimize the impacts of the offshore wind farm on the Penghu power system. Proposed strategies include: adding a LVRT (Low Voltage Ride Through) device, increasing the offshore wind farm capacity, adding FACTS (Flexible AC Transmission Systems) devices, incorporating Jiang-Shan plant, utilizing wind farm operation control mode, and increasing the impedance of the submarine cable impedance. Simulation results indicate that these strategies are effective in reducing the impacts of the wind farm on the power system. Simulation results further suggest that a greater wind farm capacity or a stronger LVRT capability helps better improve the system’s transient stability. In addition, when experiencing serious faults, the system may fail to effectively suppress the transient impact. The failure in turn may activate the protection relays of the wind farm and disconnect it from the power system, resulting in further impacts on the system. Addressing the issue, the thesis has simulated various improvement strategies of which STATCOM (Static Synchronous Compensator) appears to be the best choice thanks to its ability to facilitate reactive power compensation and its operational flexibility. This strategy is capable of improving the system’s transient low-voltage, reinforcing the LVRT strength, and speeding up the system’s recovery to normal operation after the faults are removed. The thesis can thus be expected to provide Taipower with valuable reference in planning the development of its large-scale offshore wind farm in Penghu, especially in terms of avoiding overloading of transmission facilities and solving the problem of transient instability as the wind farm is connected into the existing power system.

碩士
國立臺灣海洋大學
河海工程學系
103
The western offshore area of Taiwan is assessed as the world's best offshore wind farm by international engineering consulting firm 4C Offshore. The potential of integrated offshore wind is about 10 GW. To promote alternative energy projects, Ministry of Economic Affairs Bureau of Energy planning will build 600 offshore wind turbines in 2030. However, the special geographical environment of the offshore wind farm in the design life cycle may be affected by earthquakes and typhoons. Under in extreme conditions, it may cause the seabed soil liquefaction, leading to the shallow seabed submarine cable damage. This study, considering the actual seabed geological hazard cases and DNV standards mentioned geological risk that may occur offshore wind farm, the sensitivity factor of offshore wind farm are included as soft soil, soil liquefaction, slope stability. The criterion of sensitivity geology of offshore wind farm was established. In this study, the drilling data of site investigation of offshore wind farm was collected. By use of AutoCAD and Civilight AutoLog ver.1.02, a vertical of seabed profile was display. And also by use of ArcGIS to draw a parallel seabed profile, it can help explore offshore wind farm spatial distribution of soil properties and soil parameters for wind turbine foundation design reference. By use of the sensitivity criterion of this study, the geologic potential of each factor can determine, and the analysis of geology sensitivity was performed by superposition of each potential map. From the analysis results showed that Fuhai offshore wind farm is belong to the most geologic sensitive area. On the other hand, based on the concept of disaster risk by International Strategy for Disaster Reduction, and combined with the vulnerability factor as soft seabed soil and slope stability, and hazard factor as the potential of soil liquefaction caused by earthquake and typhoon waves the disaster risk assessment of seabed could be evaluated with risk matrix under different conditions, It could be provided the reference of design and construction of submarine cable of offshore wind farm.

碩士
國立臺灣海洋大學
河海工程學系
106
The development of offshore wind power requires a stable and reliable transmission system. Submarine power cable is an important project that affects the whole economic benefit. The economic loss caused by the submarine cable accident in the development experience of European countries is the highest item for insurance claims. Therefore, this study conducts hazard risk management research on submarine power cables in Taiwan's offshore wind farm, and hopes to reduce the damage caused by accidents through risk management and reduce possible losses. In this study, the risk factors of submarine cables were identified by cause and effect analysis. The risk matrix was used to evaluate the risk values before and after the risk disposal, and risk improvement measures were proposed to establish a submarine cable risk assessment form. The concept of managing the PDCA cycle was applied to risk management, and establish submarine power cables hazard and risk management process that combines the management of the PDCA cycle. This study also developed a submarine cable risk management plan and emergency response plan to provide the reference of the related offshore wind farm industries.

碩士
國立政治大學
台灣史研究所
98
In 1895, the Qing Dynasty was forced to sign the Treaty of Shimonoseki(馬關條約) and cede Taiwan to Japan after losing the Sino-Japanese War of 1894-1895(中日甲午戰爭). According to agreement to transfer of Taiwan all question relating to the submarine cable between Fuchow and Tamsui(福州到淡水的海底電線：閩臺海底電線)are to be settled afterwards by both Government. In 12.7,1898, to signed a Convention of the submarine cable between Fuchow and Tamsui(閩臺電線讓售合同)by China and Japan, the submarine cable belonged to Japan. According to the research of the thesis, the negotiations between China and Japan upon the submarine cable between Fuchow and Tamsui correspond to the situation of North-East Asia after Sino-Japanese War of 1894-1895. Finally, from the Russo-Japanese War to Surrender of Japanese in 1945, Taiwan became the hub of Japanese Overseas telecommunications with the submarine cable between Fuchow and Tamsui.