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Orientador: Jose Sanches Mantovani / Resumo: Neste trabalho propõem-se metodologias para realizar o planejamento de sistemas de distribuição de energia elétrica de média tensão (MT), baixa tensão (BT) e o planejamento integrado de sistemas de média e baixa tensão (MT/BT). Nos modelos de funções objetivos considerados minimizam-se os custos associados à construção, expansão, operação e confiabilidade das redes de MT, BT e MT/BT, considerando a presença de geradores distribuídos e variáveis de natureza estocástica. A geração distribuída presente no planejamento de sistemas de distribuição é avaliada através de metodologias de geração de cenários e análise de risco. Como método de busca de soluções para o problema de planejamento dos sistemas de distribuição é proposta a meta-heurística de busca em vizinhança variável GVNS (General Variable Neighborhood Search). A meta-heurística GVNS trabalha com uma série de estruturas de vizinhanças que permitem explorar o espaço de busca de forma eficiente através dos critérios de diversificação e intensificação, aumentando a probabilidade de obter soluções que não sejam ótimos locais. No planejamento integrado MT/BT, as soluções obtidas são analisadas através de um fluxo de potência integrado entre as redes de MT e BT, considerando as relações de conexão dos transformadores entre estes sistemas. Os algoritmos propostos relacionados ao planejamento de sistemas MT, BT e MT/BT são implementados em linguagem de programação C++ e testado em diferentes sistemas testes de MT (54 barras e 182... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Submitted by DIOGO RUPOLO null (rupolo.diogo@gmail.com) on 2017-09-08T14:50:14Z No. of bitstreams: 1 Tese Final Diogo Rupolo.pdf: 4125842 bytes, checksum: 60d451cc4d13afb90cca7e443d7436b1 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-09-11T20:51:49Z (GMT) No. of bitstreams: 1 rupolo_d_dr_ilha.pdf: 4125842 bytes, checksum: 60d451cc4d13afb90cca7e443d7436b1 (MD5) / Made available in DSpace on 2017-09-11T20:51:49Z (GMT). No. of bitstreams: 1 rupolo_d_dr_ilha.pdf: 4125842 bytes, checksum: 60d451cc4d13afb90cca7e443d7436b1 (MD5) Previous issue date: 2017-08-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho propõem-se metodologias para realizar o planejamento de sistemas de distribuição de energia elétrica de média tensão (MT), baixa tensão (BT) e o planejamento integrado de sistemas de média e baixa tensão (MT/BT). Nos modelos de funções objetivos considerados minimizam-se os custos associados à construção, expansão, operação e confiabilidade das redes de MT, BT e MT/BT, considerando a presença de geradores distribuídos e variáveis de natureza estocástica. A geração distribuída presente no planejamento de sistemas de distribuição é avaliada através de metodologias de geração de cenários e análise de risco. Como método de busca de soluções para o problema de planejamento dos sistemas de distribuição é proposta a meta-heurística de busca em vizinhança variável GVNS (General Variable Neighborhood Search). A meta-heurística GVNS trabalha com uma série de estruturas de vizinhanças que permitem explorar o espaço de busca de forma eficiente através dos critérios de diversificação e intensificação, aumentando a probabilidade de obter soluções que não sejam ótimos locais. No planejamento integrado MT/BT, as soluções obtidas são analisadas através de um fluxo de potência integrado entre as redes de MT e BT, considerando as relações de conexão dos transformadores entre estes sistemas. Os algoritmos propostos relacionados ao planejamento de sistemas MT, BT e MT/BT são implementados em linguagem de programação C++ e testado em diferentes sistemas testes de MT (54 barras e 182 barras), BT (76 barras) e MT/BT (172 e 412 barras), sob diferentes cenários operacionais. / This work proposes methodologies for the planning of medium voltage (MV), low voltage (LV), and integrated planning of medium and low voltage (MV/LV) systems. In the objective function models are considered the costs associated with the construction, expansion, operation and reliability of MV, LV and integrated MV/LV networks. Distributed generators and stochastic variables are also considered in the models. The distributed generation present in the planning of distribution systems is evaluated through methodologies of scenario generation and risk analysis. As a method of finding solutions to the problem of distribution system planning, the GVNS metaheuristic (General Variable Neighborhood Search) is proposed. The metaheuristic GVNS works with a series of neighborhood structures that allow to explore the search space efficiently through diversification and intensification criteria, increasing the probability of obtaining solutions that are not local optimum. In integrated MV/LV planning, the solutions obtained are analyzed through an integrated power flow between the MV and LV networks, considering the connection ratios of the transformers between these systems. The proposed algorithms related to the planning of MV, LV and integrated MV/LV systems are implemented in C ++ programming language and tested in different distribution systems, MV (54 and 182 bus), LV (76 bus) and MV/LV (172 and 412 bus), under different operating scenarios.

Lightning causes important transient disturbances on transmission and distribution systems, with consequent damages to equipment, outages, and general decrease of the power quality. The assessment of the lightning dielectric strength of power equipment is generally based on tests performed using the standard lightning impulse voltage (1.2 / 50 µs waveshape), although the characteristics of the lightning overvoltages depend on many parameters and may vary widely. The behavior of insulators when subject to non-standard impulses depends both on the voltage amplitude and waveshape, and therefore a reliable model is required to produce the corresponding volt-time curves. Although there is no method universally accepted for this purpose, one of the most used is the Disruptive Effect (DE) model, which is based on the integration method concept. The application of this model involves the estimation of some parameters for which different procedures have been proposed in the literature, as for instance the procedures by Darveniza and Vlastos, by Hileman, by Chowdhuri et al., and by Ancajima et al. Tests of representative lightning overvoltages were performed to obtain the critical flashover overvoltages (CFO) and the volt-time curves of typical porcelain pin-type insulators considering three standard medium-voltage distribution classes (15 kV, 24 kV, and 36 kV) and five impulse voltage waveshapes, of both polarities. These tests provided data for the analyses of the insulators\' behavior and the results obtained using the different procedures for estimating the DE parameters. It is shown that in some cases insulator flashover is not predicted. A new method is then developed and proposed for evaluating the dielectric behavior of MV insulators. The method is validated using the typical insulators of the three voltage classes and the five lightning impulse voltages considered, of positive and negative polarities. The calculated volt-time curves showed in general a good agreement with the measured results for all the cases studied. The mean difference between the measured and calculated times to breakdown, for all the cases considered, was about 1.3 s; while the maximum difference was 4.0 s. The application of the proposed method to evaluate the occurrence of insulator flashovers in the shield wire line (SWL) system implemented in the State of Rondônia due to nearby lightning strikes supports previous conclusions that indicate that lightning has a significant impact on the SWL system performance in regions with high ground flash density. / Descargas atmosféricas produzem distúrbios transitórios significativos em sistemas de transmissão e distribuição, com consequentes danos em equipamentos, interrupções e redução geral na qualidade de energia elétrica. A avaliação da suportabilidade dielétrica frente às descargas atmosféricas do equipamento de potência é geralmente baseada em ensaios realizados usando o impulso atmosférico de tensão normalizada (forma de onda 1.2 / 50 µs), contudo as características das sobretensões atmosféricas dependem de muitos parâmetros e podem variar amplamente. O comportamento dos isoladores quando sujeitos a impulsos não normalizados depende tanto da magnitude como da forma de onda da tensão, e então um modelo confiável é necessário para se obter as curvas tensão-tempo correspondentes. Embora não haja um método universalmente aceito para essa finalidade, um dos mais utilizados é o modelo de Efeito Disruptivo (DE), que é baseado no conceito do método de integração. A aplicação desse modelo envolve a estimativa de alguns parâmetros para os quais diferentes procedimentos têm sido propostos na literatura, como por exemplo, os procedimentos de Darveniza e Vlastos, de Hileman, de Chowdhuri et al. e de Ancajima et al. Ensaios de sobretensões atmosféricas representativas foram feitos para obter as tensões de descarga disruptiva (CFO) e as curvas de tensão-tempo de isoladores de porcelana típicos, tipo pino, considerando três classes de tensão de distribuição de média tensão (15 kV, 24 kV e 36 kV) e cinco formas de onda de impulso de tensão, de ambas as polaridades. Estes ensaios proporcionaram dados para as análises do comportamento dos isoladores e os resultados obtidos usando os diferentes procedimentos para estimar os parâmetros necessários para a aplicação do modelo do Efeito Disruptivo. É mostrado que em alguns casos a disrupção no isolador não é prevista por tais procedimentos. Um novo método é, então, desenvolvido e proposto para avaliar o comportamento dielétrico dos isoladores de média tensão. O método é validado usando os isoladores típicos das três classes de tensão e as cinco formas de tensões de impulso atmosféricos consideradas, de polaridades positiva e negativa. As curvas tensão-tempo calculadas mostraram, em geral, boa concordância com os resultados medidos para todos os casos estudados. A diferença média entre os tempos de disrupção medidos e calculados, para todos os casos considerados, foi da ordem de 1,3 s; enquanto a máxima diferença foi de 4,0 s. A aplicação do método proposto para avaliar a ocorrência de disrupções em isoladores do Sistema de Cabo Para-raios Energizados (PRE), implementado no estado de Rondônia, devido a descargas atmosféricas indiretas, apoia as conclusões previamente obtidas que indicam que as descargas atmosféricas têm impacto significativo sobre o desempenho do sistema PRE em regiões com alta densidade de descargas para solo.

Lightning causes important transient disturbances on transmission and distribution systems, with consequent damages to equipment, outages, and general decrease of the power quality. The assessment of the lightning dielectric strength of power equipment is generally based on tests performed using the standard lightning impulse voltage (1.2 / 50 µs waveshape), although the characteristics of the lightning overvoltages depend on many parameters and may vary widely. The behavior of insulators when subject to non-standard impulses depends both on the voltage amplitude and waveshape, and therefore a reliable model is required to produce the corresponding volt-time curves. Although there is no method universally accepted for this purpose, one of the most used is the Disruptive Effect (DE) model, which is based on the integration method concept. The application of this model involves the estimation of some parameters for which different procedures have been proposed in the literature, as for instance the procedures by Darveniza and Vlastos, by Hileman, by Chowdhuri et al., and by Ancajima et al. Tests of representative lightning overvoltages were performed to obtain the critical flashover overvoltages (CFO) and the volt-time curves of typical porcelain pin-type insulators considering three standard medium-voltage distribution classes (15 kV, 24 kV, and 36 kV) and five impulse voltage waveshapes, of both polarities. These tests provided data for the analyses of the insulators\' behavior and the results obtained using the different procedures for estimating the DE parameters. It is shown that in some cases insulator flashover is not predicted. A new method is then developed and proposed for evaluating the dielectric behavior of MV insulators. The method is validated using the typical insulators of the three voltage classes and the five lightning impulse voltages considered, of positive and negative polarities. The calculated volt-time curves showed in general a good agreement with the measured results for all the cases studied. The mean difference between the measured and calculated times to breakdown, for all the cases considered, was about 1.3 s; while the maximum difference was 4.0 s. The application of the proposed method to evaluate the occurrence of insulator flashovers in the shield wire line (SWL) system implemented in the State of Rondônia due to nearby lightning strikes supports previous conclusions that indicate that lightning has a significant impact on the SWL system performance in regions with high ground flash density. / Descargas atmosféricas produzem distúrbios transitórios significativos em sistemas de transmissão e distribuição, com consequentes danos em equipamentos, interrupções e redução geral na qualidade de energia elétrica. A avaliação da suportabilidade dielétrica frente às descargas atmosféricas do equipamento de potência é geralmente baseada em ensaios realizados usando o impulso atmosférico de tensão normalizada (forma de onda 1.2 / 50 µs), contudo as características das sobretensões atmosféricas dependem de muitos parâmetros e podem variar amplamente. O comportamento dos isoladores quando sujeitos a impulsos não normalizados depende tanto da magnitude como da forma de onda da tensão, e então um modelo confiável é necessário para se obter as curvas tensão-tempo correspondentes. Embora não haja um método universalmente aceito para essa finalidade, um dos mais utilizados é o modelo de Efeito Disruptivo (DE), que é baseado no conceito do método de integração. A aplicação desse modelo envolve a estimativa de alguns parâmetros para os quais diferentes procedimentos têm sido propostos na literatura, como por exemplo, os procedimentos de Darveniza e Vlastos, de Hileman, de Chowdhuri et al. e de Ancajima et al. Ensaios de sobretensões atmosféricas representativas foram feitos para obter as tensões de descarga disruptiva (CFO) e as curvas de tensão-tempo de isoladores de porcelana típicos, tipo pino, considerando três classes de tensão de distribuição de média tensão (15 kV, 24 kV e 36 kV) e cinco formas de onda de impulso de tensão, de ambas as polaridades. Estes ensaios proporcionaram dados para as análises do comportamento dos isoladores e os resultados obtidos usando os diferentes procedimentos para estimar os parâmetros necessários para a aplicação do modelo do Efeito Disruptivo. É mostrado que em alguns casos a disrupção no isolador não é prevista por tais procedimentos. Um novo método é, então, desenvolvido e proposto para avaliar o comportamento dielétrico dos isoladores de média tensão. O método é validado usando os isoladores típicos das três classes de tensão e as cinco formas de tensões de impulso atmosféricos consideradas, de polaridades positiva e negativa. As curvas tensão-tempo calculadas mostraram, em geral, boa concordância com os resultados medidos para todos os casos estudados. A diferença média entre os tempos de disrupção medidos e calculados, para todos os casos considerados, foi da ordem de 1,3 s; enquanto a máxima diferença foi de 4,0 s. A aplicação do método proposto para avaliar a ocorrência de disrupções em isoladores do Sistema de Cabo Para-raios Energizados (PRE), implementado no estado de Rondônia, devido a descargas atmosféricas indiretas, apoia as conclusões previamente obtidas que indicam que as descargas atmosféricas têm impacto significativo sobre o desempenho do sistema PRE em regiões com alta densidade de descargas para solo.

Ο στόχος της διπλωματικής αυτής είναι η περιγραφή της αναδυόμενης τεχνολογίας PLC (PowerLine Communication). Η τεχνολογία αυτή με τη χρήση του πανταχού παρόντος ηλεκτρικού δικτύου προσφέρει ακόμα και σε απομακρυσμένους χρήστες πληθώρα ευρυζωνικών υπηρεσιών και πρόσβαση στο διαδίκτυο, αποτελώντας μια ανταγωνιστική επιλογή τρόπου επικοινωνίας. Για την κατανόηση της PLC τεχνολογίας αρχικά κρίνουμε απαραίτητη την λεπτομερή περιγραφή της δομής του ηλεκτρικού δικτύου, του εξοπλισμού που απαιτείται για την εφαρμογή της και των αρχιτεκτονικών της. Στη συνέχεια γίνεται αναφορά στα προβλήματα που παρουσιάζονται και χρήζουν αντιμετώπισης. Επιπρόσθετα, γίνεται σύντομη παρουσίαση των εναλλακτικών υπηρεσιών και σύγκριση των PLC με αυτές. Η μετάδοση μέσω ηλεκτροφόρων καλωδίων προσφέρει ένα μεγάλο εύρος ζώνης, παρέχοντας μία γκάμα πολυάριθμων υπηρεσιών, όπως το έξυπνο σπίτι ή το AMR (Automatic Meter Reading) για τη διευκόλυνση τόσο των οικιακών χρηστών όσο και των επιχειρησιακών. Η χρήση των γραμμών ηλεκτρικής ενέργειας ως τηλεπικοινωνιακό κανάλι απαιτεί την εφαρμογή των κατάλληλων τεχνικών πρόσβασης. Οι πιο διαδεδομένες τεχνικές είναι οι FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access) και CDMA (Code Division Multiple Access) . Η παρούσα διπλωματική επικεντρώθηκε στην TDMA και την FDMA με διαμόρφωση σήματος OFDM (Orthogonal Frequency Division Multiplexing) η οποία ονομάζεται OFDMA (Orthogonal Frequency Division Multiple Access). Πραγματοποιήθηκαν εξομοιώσεις σε Matlab διάφορων αλγορίθμων αναλογικής δικαιοσύνης με τεχνική OFDMA και ταυτόχρονη εξομοίωση της TDMA. Στόχος είναι να συγκρίνουμε τους αλγόριθμους αυτούς ως προς το συνολικό ρυθμό μετάδοσης και τη δικαιοσύνη κατανομής των πόρων στους χρήστες. Από τη σύγκριση αυτή προκύπτει ότι η τεχνική TDMA αποδίδει λιγότερο, ενώ από τους υπόλοιπους αλγόριθμους τα καλύτερα αποτελέσματα επιφέρει ο αλγόριθμος των Bill et al., με ισορροπία του συνολικού ρυθμού μετάδοσης και της επιθυμητής δικαιοσύνης. / Main goal of this diploma thesis is the description of the up and coming PLC (PowerLine Communication) technology. This technology offers access to the web and to several broadband services to even distant and isolated users, by exploiting the power line grid, widely spread to nearly all surface land sites, consisting this way a competitive communication alternative. For a better comprehension of the PLC technology, this work starts with a detailed description of the power line grid, the several PLC technology architectures and the necessary equipment for their application. Following this work, there is a reference to any possible problems that need to be overcome and a short comparative presentation of the PLC technology versus other alternatives to it. The data transmission over electricity lines offers a wide bandwidth and thus it may support a variety of applications, as the smart home and AMR (Automatic Meter Reading) for the proper service of either domestic or industrial users. The use of electricity power lines as a communication channel necessitates the application of multiple access Strategies as FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access), which are currently the most popular. This thesis is focused on TDMA and FDMA with OFDM signal modulation. This technique is called OFDMA (Orthogonal Frequency Division Multiple Access). Several proportional rate constraints algorithms were simulated in Matlab applying both OFDMA and TDMA strategies in order to compare these algorithms in terms of the maximized total throughput and the fair allocation of resources to the end users (fairness). From this comparison it comes up that TDMA technique is less efficient, whereas from the other algorithms the most efficient is the one of Bill et al., that offers a good balance between total throughput and fairness.

Submitted by Tiago Gomes dos Santos (1.tiago.gomes@gmail.com) on 2016-03-07T21:19:09Z No. of bitstreams: 1 Dissertação-Tiago PUBLICAÇÃO.pdf: 689972 bytes, checksum: f7d805d6ea6871e17e9df83d7b87cac6 (MD5) / Approved for entry into archive by Rafael Aguiar (rafael.aguiar@fgv.br) on 2016-04-19T19:43:17Z (GMT) No. of bitstreams: 1 Dissertação-Tiago PUBLICAÇÃO.pdf: 689972 bytes, checksum: f7d805d6ea6871e17e9df83d7b87cac6 (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2016-04-20T13:13:04Z (GMT) No. of bitstreams: 1 Dissertação-Tiago PUBLICAÇÃO.pdf: 689972 bytes, checksum: f7d805d6ea6871e17e9df83d7b87cac6 (MD5) / Made available in DSpace on 2016-04-20T13:13:36Z (GMT). No. of bitstreams: 1 Dissertação-Tiago PUBLICAÇÃO.pdf: 689972 bytes, checksum: f7d805d6ea6871e17e9df83d7b87cac6 (MD5) Previous issue date: 2015-04-16 / This research is dedicated to study the use of audiovisual language as an instrument of production of meaning and legitimacy of the 'locals' as the 'authentics' representatives of the slum. The music video 'Soldado do morro' (2000), the documentary 'Falcão – Meninos do tráfico' (2006) and the episode 'Arroz com Feijão' (Rice and Beans) from the movie '5 x Favela – Agora por nós mesmos' (5 x Favela – Now by ourselves) are our objects of investigation to understand how, through these audiovisual products, CUFA has reached the level of 'legitimate' representative of the slums and how this representation space can operate in the market logic. / A presente pesquisa dedica-se ao estudo da utilização de produtos audiovisuais como um instrumento de produção de significados e legitimação dos 'locais' como os 'autênticos' representantes da favela. O videoclipe 'Soldado do morro' (2000), o documentário 'Falcão – Meninos do tráfico' (2006) e o episódio 'Arroz com Feijão' do filme '5 x Favela – Agora por nós mesmos' (2010) são nossos objetos de investigação para compreender como a CUFA através desses produtos audiovisuais alcançou o patamar que lhe posicionou como uma das instituições mais representativas das favelas cariocas e de como esse espaço de representação pode operar na lógica de mercado.

This Master´s thesis examines structural links on the number of foreigner nationals legally staying in the territory of South Bohemia between 2000 and 2016. The following objectives have been defined: Objective 1: To acquire a comprehensive overview of the number of foreigners with long-term or permanent residence living in the territory of South Bohemia between 2000 and 2016 and to demonstrate the current trends Objective 2: To demonstrate the link between the annual approved long-term or permanent residence in the territory of South Bohemia between 2000 and 2016 Objective 3: To perform a comparison of the results achieved with the European trends Due to the results achieved by the applied quantitative research, the objectives of the thesis are considered to have been met. The theoretical part of the thesis covered the strategy of the migration policy of the Czech Republic. This part defines a concept of migration, in conjunction with the legislative aspect of the given case, the concept of a foreign national and categories of residential permits, as long-term and permanent residence, depending on their duration, including an analysis of different types of long-term and permanent residence. Initially, the purpose of the practical part consisted in the collection of statistical data necessary for the examination of a dependence in the form of the most important statistical indicators for the specified years, i.e. between 2000 and 2016. The tables and charts necessary for the regression analysis of long-term and permanent residence, and for the correlative research of a dependence between long-term and permanent residence needed to evaluate the objectives of this research, were created based on acquired data files. The aim of this Master´s thesis was to evaluate, confirm or refute the following hypotheses: H1 Hypothesis: The annual numbers of foreigner nationals with permanent residence can be expressed by a linear regression model, which shows an increasing trend. H2 Hypothesis: The annual numbers of foreigner nationals with long-term residence can be expressed by a linear regression model, which shows an increasing trend. H3 Hypothesis: The annual numbers of foreigner nationals with permanent and long-term residence positively correlate. The H1 hypothesis was verified by a linear regression model for approved permanent residence. The H2 hypothesis was verified for the first interval (the first 7 years with a rising linear regression) and partly for the second interval (the remaining years until 2016 with a decreasing linear regression). In general, the adoption of the H2 hypothesis should be assumed distantly (the economic crisis intervention, the role of the 5-year period). The H3 hypothesis is on the verge of rejection - the consequences of the economic crisis and the 5-year period reveal either a very weak positive correlation between permanent and long-term residence or an uncorrelated form. The findings provided in the Master´s thesis generate a number of other topics for follow-up research (a link to economic cycles, connection to the parameters of asylum procedures).

Le réglage de la tension et la gestion de la puissance réactive est d’une importance capitale pour le bon fonctionnement du système électrique. Les réseaux de distribution connaissent des modifications profondes qui sont tant techniques avec l’insertion de la production décentralisée ou l’enfouissement des lignes aériennes, que réglementaires avec l’entrée en vigueur des codes de réseaux Européens. Aussi, des alternatives aux réglages traditionnels de tension et la mise en place de contrôle des échanges de puissance réactive à l’interface réseau de transport/distribution peuvent être développées. Dans le cadre de ces travaux de doctorat, une solution basée sur l’amélioration du réglage temps réel des réseaux de distribution ainsi que la mise en place d’une gestion conjointe de la puissance réactive entre les gestionnaires du réseau de transport et distribution a été proposée. Ce réglage temps réel est basé sur une méthode de commande prédictive, et s’appuie notamment sur le régleur en charge ou les productions décentralisées pour réaliser un réglage de la tension au sein d’un réseau de distribution et contrôler les échanges de puissance réactive. Les références de puissance réactive à atteindre à l’interface entre réseau de distribution et de transport sont déterminées par le gestionnaire du réseau de transport pour ses propres besoins et en connaissance des réserves de puissance réactive disponible depuis les réseaux de distribution. Par rapport à la littérature, notre démarche a pour originalité de prendre en compte les problèmes à l’interface des réseaux de distribution et de transport et démontre l’intérêt de mener des études conjointes entre gestionnaires / Voltage and reactive power control are of paramount importance to ensure safe and reliable operation of the power system. Distribution grids are undergoing major changes, namely the insertion of distributed generation and the replacement of overhead lines. Along with these physical evolutions, new distribution networks should comply with the requirements of the European Grid Codes on the reactive power exchange at the HV/MV interface. To handle these new operational concerns, alternative solutions to the traditional voltage and reactive power control can be found. In our work, a scheme based on the evolution of the real-time Volt Var Control (VVC) of distribution networks and a joint coordination for the reactive power management of a HV system has been proposed. The real-time VVC of MV grids is based on a predictive control method. This control uses in a coordinated manner the on load tap changer, the distributed generation and the capacitor banks to enforce a suitable MV voltage profile and an appropriate HV/MV reactive power exchange. The reactive power targets at the HV/MV interface are determined by the Transmission System Operator for its own requirements but considering the true MV reactive power reserve. Compared to the literature, the novelty of our approach consists in considering the concerns at the HV/MV system interface. Next our works have shown the relevance of performing joint transmission and distribution system operators analysis.

In the introduction a traction circuit is analyzed with different types of electric devices. The thesis describes power railway electric circuits, their loads and types of used contactors. Railway standards chapter summarizes requirements of standards for railway contactors. Follows literature focusing on power current switching and power switching devices design. Based on previous, a design procedure is developed for railway MV contactor in accordance with end-user and standards requirements. Thesis closes with pre-designing a railway contactor by calculating electrodynamic forces, heatflow and mechanical components.