Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-27T14:50:55Z No. of bitstreams: 1 carolinaventuripinheiro.pdf: 2690052 bytes, checksum: 1d8da177ba05614f2f5b1f876bebdaa4 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-27T15:51:51Z (GMT) No. of bitstreams: 1 carolinaventuripinheiro.pdf: 2690052 bytes, checksum: 1d8da177ba05614f2f5b1f876bebdaa4 (MD5) / Made available in DSpace on 2016-07-27T15:51:51Z (GMT). No. of bitstreams: 1 carolinaventuripinheiro.pdf: 2690052 bytes, checksum: 1d8da177ba05614f2f5b1f876bebdaa4 (MD5) Previous issue date: 2016-04-07 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Uma questão importante para a inserção da geração distribuída (GD) é a confiabilidade e a qualidade de energia fornecida aos consumidores. Este trabalho visa analisar a conexão de um sistema fotovoltaico (PV) e seus efeitos na rede elétrica utilizando simulação em tempo real. O sistema de simulação implementado consiste de sistemas fotovoltaicos, conversores de energia, carga variável e rede elétrica, implementados em um Real Time Digital Simulator (RTDS), enquanto que o controle é executado a partir da plataforma dSPACE, caracterizando uma sistema de simulação do tipo Hardware In the Loop (HIL). Os modelos de carga foram desenvolvidos com base em perfis de demanda reais, a partir de três alimentadores de distribuição diferentes da cidade de Leopoldina, no estado de Minas Gerais. Os dados de medição dos alimentadores foram tomados com um intervalo de 15 minutos, totalizando um tempo de medição de 24 horas. Dados de radiação solar usadas nos modelos PV foi medido no Labsolar - Universidade Federal de Juiz de Fora, também por um período de 24 horas. O propósito deste estudo é executar uma simulação HIL, combinando RTDS e dSPACE, que é um controlador digital. Com o tempo real é possível investigar o comportamento do sistema com a potência injetada pelo sistema PV, incluindo o controle do inversor utilizado para acoplar os diferentes sistemas fotovoltaicos à rede, em uma modelagem que se aproxima da realidade, com menores custos de implementação e maior segurança. Os resultados mostram uma comparação entre a potência ativa e reativa injetada pelos sistemas fotovoltaicos e a rede, e a energia consumida pelas cargas, validando a estratégia de controle implementada. / An important issue for the integration of Distributed Generation (DG) is the reliability and quality of energy supplied to consumers. This work aims at analyzing the grid connection of a photovoltaic (PV) system and its effects on the electrical network using realtime simulation. The implemented simulation system consists of photovoltaic systems, power converters, variable load and electrical grid, implemented in Real Time Digital Simulator (RTDS) while the control is run from the dSPACE controller, creating a Hardware In the Loop (HIL) platform. The load models were developed based on actual demand profile from three different distribution feeders of the city of Leopoldina, in the state of Minas Gerais. The feeders’ measurement data was taken with an interval of 15 minutes, with a total measurement time of 24 hours. Solar radiation data used in the PV models has been measured at the Solar Laboratory – Universidade Federal de Juiz de Fora, also for a 24-hour period. The purpose of this study is to perform a HIL simulation, combining RTDS and dSPACE, which is a digital controller. With real-time/ HIL simulation, it is possible to investigate the behavior of the system with the power injected by the PV system, including inverter control used to attach the different photovoltaic systems to the grid, in a model which approaches reality, with low implementation cost and higher safety. Results show a comparison between the active and reactive power injected by the photovoltaic system and network, and the power consumed by the loads, verifying the implemented control strategy.

Extracting the Electric Network Frequency (ENF) fluctuations from an audio recording and comparing it to a reference database is a new technology intended to perform forensic digital audio authentication. The objective of this thesis is to implement and design a range of programs and algorithms for capturing and extracting ENF signals. The developed C-program combined with a probe can be used to build the reference database. Our implementation of the Short-Time Fourier Transform method is intended for the ENF extraction of longer signals while our novel proposed use of the Autoregressive parametric method and our implementation of the zero-crossing approach tackle the case of shorter recordings. A Graphical User Interface (GUI) was developed to facilitate the process of extracting the ENF fluctuations. The whole process is tested and evaluated for various scenarios ranging from long to short recordings.

The aim of this work is focus on Powerline Communication technology and select a suitable type of broadband integrated circuit for the integration of a broadband communication module into an electrical installation box. In the introduction of this work, the Powerline Communication technology, the principle of communication, individual types of technology, factors influencing the quality of transmission, current possibilities and setting goals necessary for the design of the module are analyzed in detail. The result is a miniaturized functional prototype of a fully integrated broadband PLC modem in a wiring box.

The topic of the thesis is economical appraising of run the power from cogeneration units to different voltage level. There is sloves in the text, how and under what conditions we can find an optimal solution for the deployment of cogeneration units to the electricity network. The main criterion is the loss of networks and their economic evaluation. We are a description of the different types of cogeneration units, the economic balance and a treatise on losses in electrical networks.

This MASTER`S THESIS engages in connecting with dispersed generation into electrical network and their influence on power quality. This thesis sets out to make up simple dynamic model of Wind power station and model of simple network. At this model I would like to simulate influence its working on voltage’s characteristics in addition place. Besides this is necessary calculate voltage’s characteristics according present methods – factory energy rules [PNE]. And these results compare with results of simulation

This Master’s thesis deals with the problem of distribution electrical network with a focus on solving the steady operation of the electrical distribution network for E.ON Brno - Lisen. The calculation is made by using BIZON PAS Off-Line. The first part of thesis is specialized on the distribution of individual LV and MV networks.The second part of thesis is specialized on the general calculation of the steady operation distribution network and describe criteria for the design and evaluation of this network. In the practical part is calculate existing network in selected area in which is located 53 distribution transformers. In the final part is evaluate the status of existing network and perform design optimization and assessment of this network.

The aim of this Master’s thesis is the design and reconstruction of the high voltage distribution network for the company E. ON with focus on calculation of the stabilized operation and on the planning of new cable taps from the transformer substation Moravany u Brna. The first part of the theoretical analysis of the work deals with the inclusion of the distribution network into the power system and with principles of development and construction of high voltage networks. The second part includes a general calculation of stabilized operation of the power distribution network and a familiarization with the program PAS Off - Line Bison 4.0. The practical part of the thesis is focused on the calculation of the stabilized operation at the current state of transformer substation Moravany u Brna using the PAS Off - Line Bizon 4.0 V programme. This part also contains the design of six new cable lines which are needed to strengthen the power distribution in the southern part of the city Brno. The closing part of this chapter constitutes of a outdoor and indoor cable line renovation. These cables are connected to the transformer substation Moravany u Brna and a calculation of stabilized operation is also included in this part.

This thesis deals with load flow calculation of electrical network 110 kV before and after the connection to the 70MW gas supply and the 58MW steam and gas supply. This grid can be powered from two 400/110kV substations, namely Sokolnice and Otrokovice. The load flow calculation is realized for the power supply either from Otrokovice or Sokolnice. Furthermore, the calculation of the uni-phase and three phase short circuits in the substations of 110kV network is realized in this thesis. The result of the thesis is the assessment of the voltage ratio in the network, current load of the power line and short circuit resistance of the substations.

Les avions du futur auront une topologie tout électrique. Pour cela, les constructeurs augmentent la puissance et la tension d'utilisation du réseau d'énergie embarqué. Cependant, le défaut d'arc électrique est un risque qui est souvent la cause d'incidents d'exploitation voire de crash. La contribution de cette thèse porte sur la problématique de l'identification et la détection de défauts électriques sur un réseau de distribution d'énergie de type HVDC ±270VDC destiné à l'aéronautique. Dans ce manuscrit, le premier axe suivi est exploratoire. Il porte sur l'observation du comportement et de la phénoménologie d'arc dans le milieu proche de l'aéronautique (notamment par l'émulation de l'altitude par la pression). Le second axe de recherche porte sur l'analyse, la mise au point et le développement de méthode de détection fiable d'un défaut d'arc électrique par un coeur de distribution d'énergie (SSPC) sur charges résistive et légèrement inductive. Cinq méthodes ont été développées au cours de ce travail de thèse. Elles sont basées sur l'analyse des caractéristiques temporelles, fréquentielles et temps-fréquence du courant de ligne. À l'issue de chaque méthode est produit un indicateur qui est ensuite utilisé par une logique de discrimination dépendant de chaque critère. Le comportement non-déterministe des arcs notamment aux conditions d'expérimentation (courant, tension, matériaux des électrodes, longueur de l'arc, etc.) rendent la détection difficile par un simple seuil sur le résultat des critères. Dans ces travaux, une approche proportionnelle au défaut est proposée pour la discrimination à l'aide de seuils variables selon le courant, la variation de charge ou le bruit électrique du système. Le résultat combiné des méthodes aboutit à une décision de mise en protection. Pour valider expérimentalement les algorithmes proposés, une vaste base de données a été constituée comprenant aussi bien des signaux de nature résistive que selfique avec à la fois des arcs et des variations de charges sans arcs afin de vérifier qu'aucune détection n'opère à tort. Le fruit de ces travaux a été en partie implémenté dans un prototype d'analyse en temps réel de la ligne de distribution / Tomorrow’s aircraft will have an all-electric topology. This mean, manufacturers boost power and voltage of the embedded energy network. Nevertheless, the lack of an electric arc is a risk that is often the cause of the crash or operated occurrences. This thesis contributions concerns identification issue and electric arc fault detection on an energy distribution smart grid of HVDC network dedicated to avionic. The first line of this manuscript is exploratory. It covers behavioural observation and arc phenomenology in the grounded sphere of aeronautic (in particular emulated altitude by pressure). The second line of research deals with analysis, clarification and development of reliable approach of electric arc default detection through a central energy distribution on resistive charges. Five methods have been initiated throughout this thesis paper. They are based on several characteristic (time, frequency and time-frequency) of the line current. An indicator is produced at the end of each method. Subsequently, the indicator is used by a logic of discrimination according to each criterion. The non-deterministic behaviour of arc notably testing conditions (current, voltage, electrode materials, etc. makes detection difficult by a simple threshold on result of criteria. In this work, a new approach of arc fault discrimination is proposed. This used a proportional and variable threshold according to the current, load or noise variations from the system. The combined outcome of method results to a decision providing protection. To confirm experimentally proposed algorithms, a wide range database has been established. That included equally resistive and inductive signals with both arcs and load variations without arc fault so as to ensure that any detection is not mistakenly occurring. The upshot of this research work has been implemented in real time protection device prototype for HVDC +-270V smart-grid

Cette thèse étudie les problèmes liés à l’association des principaux composants des réseaux électriques.La nature inductive des éléments à connecter pose des problèmes lors de leur association dans un nœud de connexion commun. Deux solutions sont proposées pour résoudre ce problème et rendre ainsi possible la simulation. Une première solution accepte la présence de causalités dérivées, la deuxième consiste à simplifier les modèles en supprimant localement les régimes dynamiques pour faciliter leur association.La mise en évidence graphique de la causalité dans le modèle global d’un micro réseau à structure variable montre que différentes configurations sont possibles, avec pour chacune un comportement et un fonctionnement différents pour les composants. L’outil bond graph a été choisi pour la modélisation des différents éléments, l’analyse des propriétés des modèles et la conception de lois de commande par modèle inverse à l’aide de la bicausalité. La robustesse de la commande pour le convertisseur d’électronique de puissance est analysée d’une manière classique pour tester ses performances par rapport aux incertitudes paramétriques, en faisant varier la charge connectée au convertisseur. La commande est validée par simulation et de manière expérimentale / This thesis concerns the problem linked to the association of the main components of an electrical network.The inductive nature of the elements to be connected involved some problems for their association through a common connection node. Two solutions are proposed to solve this problem and thus make possible the simulation. One solution accepts the presence of derivative causality in the global model, the second one consists in simplifying the models by removing locally dynamic modes to facilitate their association.The graphical description of causality in the global model of a micro grid with variable structure shows up that different configurations are possible, with different behavior and functioning for the components in each case.The bond graph tool has been chosen for modeling the different components, analyzing the model properties and designing control laws based on inverse models derived from bicausal bond graph. Robustness to parameter uncertainties of the electronic power converter control law is analyzed in a traditional way, by varying the load connected to the power converter. The control law is validated by simulation and experimentally