Recently, interest in Smart Grid (SG) as a tool for modernization and automation of the current distribution system has rapidly increased. This interest can be explained by the common belief that SG technologies greatly enhance system reliability, power quality and overall efficiency. One of the most important objectives of an SG is to accommodate a wide variety of generation options. This objective aligns with the new trends and policies that encourage higher penetration levels of Distributed Generation (DG) according to environmental, regulatory and economical concerns. Most DG units are either renewable or low emission energy sources, thus meeting the Canadian emission portfolios, while they remain attractive for both utilities and customers for different reasons. DG units can postpone large investment in transmission and central generation, reduce energy losses, and increase system reliability and power quality. SG is centered on several objectives such as self-healing, motivating consumers to participate in grid operation, resisting attacks, accommodating a wide variety of DG units and storage devices, and optimizing assets. Yet, one of the main goals of SG is to increase the reliability of power systems. Reliability is a vital factor in power system performance, due to the full dependence of today???s life on electricity and the high cost of system outages, especially for critical loads. Therefore, one of the main salient features of SG is its ability of self-healing. The insertion of DG units changes distribution networks from being passive with unidirectional power flow and a single power source (the primary substation) towards active networks with multi-directional power flow and several power sources (the primary substation, along with DG units). As a result, the interconnection of DG units creates several impacts on different practices such as voltage profile, power flow, power quality, stability, reliability, fault detection, and restoration. Current policies call for the direct disconnection of all DG units once any failure occurs in the network. However, with a high DG power penetration, the utilities cannot operate the system efficiently without the DG units??? support. Furthermore, automatic disconnection of the DG units during faults reduces the expected benefits associated with DG units drastically. Motivated by the above facts, the overall target of this thesis is to introduce distribution system mechanisms to facilitate realizing the concept of Smart Distribution System (SDS) in both normal and emergency modes. In particular, three main functions are dealt with in this research work: distribution network reconfiguration, DG allocation and self-healing. First, for distribution network reconfiguration, a method based on genetic algorithm is presented to address the reconfiguration problem for distribution systems while the effect of load variation and the stochastic power generation of renewable-based DG units are taken into consideration. The presented method determines the annual distribution network reconfiguration scheme considering switching operation costs in order to minimize annual energy losses by determining the optimal configuration for each season of the year. Second, for DG allocation, a joint optimization algorithm has been proposed to tackle the DG allocation and network reconfiguration problems concurrently, as these two issues are inherently coupled. The two problems are dealt with together while the objectives are minimizing the cost, as an economic issue, and greenhouse gas emissions, as an environmental issue. The proposed method takes the probabilistic nature of both the renewable energy resources and loads into account. The last operation function dealt with in this thesis is distribution system restoration. In order to accomplish this function, two stages are presented: In the first stage, numerous practical aspects related to service restoration problem have been investigated. These aspects include variations in the load and customer priorities, price discounts for in-service customers based on their participation in a load-curtailment scheme that permits other customers to be supplied, the presence of manual and automated switches, and the incorporation of DG units (dispatchable and wind-based units) in the restoration process. In the second stage, the smart grid concept and technologies have been applied to construct a self-healing framework to be applied in smart distribution systems. The proposed multi-agent system is designed to automatically locate and isolate faults, and then decide and implement the switching operations to restore the out-of-service loads. Load variation has been taken into consideration to avoid the need for further reconfigurations during the restoration period. An expert-based decision-making algorithm has been used to govern the control agents. The rules have been extracted from the practical issues related to the service restoration problem, discussed in the first stage.

Les engagements étatiques relatifs au secteur du transport promouvoient la popularisation des véhicules rechargeables conformément aux exigences actuelles qu'elles soient environnementales, techniques ou encore économiques. Ipso facto, ces travaux de thèse, assimilés à la thématique des Smart Grids, exposent une contribution à une gestion orientée du tryptique réseaux électriques, véhicules rechargeables et secteurs résidentiels. La première étape du travail consiste en l'évaluation des impacts liés à un taux de pénétration élevé. Les travaux se sont ensuite focalisés sur deux problèmes importants qui sont la tenue du plan de tension et le vieillissement accéléré des transformateurs de distribution HTA/BT, plus particulièrement ceux alimentant des secteurs résidentiels. Partant, des stratégies de modulation de la charge des batteries embarquées sont proposées et évaluées. Dans une seconde partie, en se basant sur l'hypothèse de bidirectionnalité énergétique du véhicule électrique hybride rechargeable (Plug-in Hybrid Electric Vehicle - PHEV), est exploré les possibilités d'effacement de pointe et de diminution des puissances souscrites ; conformément au concept Vehicle-to-Home. Les aspects économiques ne sont pas évacués ; à ce titre la minimisation de la facture énergétique d'un logement fait l'objet d'un regard particulier sous contrainte d'une tarification variable, le V2H servant de levier. Le véhicule bidirectionnel est enfin mis à contribution via une algorithmique adaptée à des fins de réglage du plan de tension et contribue ainsi au concept Vehicle-to-Grid.

This thesis presents a novel, fast, and accurate 3 steady-state power-flow analysis (PFA) tool for the real-time operation of the active distribution systems, also known as the active distribution networks (ADN), in the grid-tied and islanded operating modes. Three-phase power-flow models of loads, transformers, and multi-phase power lines and laterals are provided. This thesis also presents novel steady-state, fundamental-frequency, power-flow models of voltage-sourced converter (VSC)-based distributed energy resource (DER) units. The proposed models address a wide array of DER units, i.e., (i) variable-speed wind-driven doubly-fed asynchronous generator-based and (ii) single/three-phase VSC-coupled DER units. In addition, a computationally-efficient technique is proposed and implemented to impose the operating constraints of the VSC and the host DER unit within the context of the developed PFA tool. Novel closed forms for updating the corresponding VSC power and voltage reference set-points are proposed to guarantee that the power-flow solution fully complies with the VSC constraints. All the proposed DER models represent (i) the salient VSC control strategies and objectives under balanced and unbalanced power-flow scenarios and (ii) all the operating limits and constraints of the VSC and its host DER unit. Also, the slack bus concept is revisited, associated with the PFA, where a 3 distributed slack bus (DSB) model is proposed for the PFA and operation of islanded ADNs. Distributing the real and reactive slack power among several DER units is essential to provide a realistic power-flow approach for ADNs in the absence of the utility bus. The proposed DSB model is integrated with the developed 3 PFA tool to form a complete ADN PFA package. The new PFA tool, including the proposed DER and DSB models, is tested using several benchmark networks of different sizes, topologies, and parameters. Many case studies, encompassing a wide spectrum of DER control specifications and operating modes, are conducted to demonstrate (i) the numerical accuracy of the proposed models of the DER units and their operating constraints, (ii) the effectiveness of the proposed DSB model for the islanded ADN PFA, and (iii) the computational efficiency of the integrated PFA software tool irrespective of the network topology and parameters.

This thesis presents a novel, fast, and accurate 3 steady-state power-flow analysis (PFA) tool for the real-time operation of the active distribution systems, also known as the active distribution networks (ADN), in the grid-tied and islanded operating modes. Three-phase power-flow models of loads, transformers, and multi-phase power lines and laterals are provided. This thesis also presents novel steady-state, fundamental-frequency, power-flow models of voltage-sourced converter (VSC)-based distributed energy resource (DER) units. The proposed models address a wide array of DER units, i.e., (i) variable-speed wind-driven doubly-fed asynchronous generator-based and (ii) single/three-phase VSC-coupled DER units. In addition, a computationally-efficient technique is proposed and implemented to impose the operating constraints of the VSC and the host DER unit within the context of the developed PFA tool. Novel closed forms for updating the corresponding VSC power and voltage reference set-points are proposed to guarantee that the power-flow solution fully complies with the VSC constraints. All the proposed DER models represent (i) the salient VSC control strategies and objectives under balanced and unbalanced power-flow scenarios and (ii) all the operating limits and constraints of the VSC and its host DER unit. Also, the slack bus concept is revisited, associated with the PFA, where a 3 distributed slack bus (DSB) model is proposed for the PFA and operation of islanded ADNs. Distributing the real and reactive slack power among several DER units is essential to provide a realistic power-flow approach for ADNs in the absence of the utility bus. The proposed DSB model is integrated with the developed 3 PFA tool to form a complete ADN PFA package. The new PFA tool, including the proposed DER and DSB models, is tested using several benchmark networks of different sizes, topologies, and parameters. Many case studies, encompassing a wide spectrum of DER control specifications and operating modes, are conducted to demonstrate (i) the numerical accuracy of the proposed models of the DER units and their operating constraints, (ii) the effectiveness of the proposed DSB model for the islanded ADN PFA, and (iii) the computational efficiency of the integrated PFA software tool irrespective of the network topology and parameters.

With the rapid growth of energy demand and consequently growth in supply, increasing energy costs, and environmental concerns, there is a critical need to find new ways to make better use of existing energy systems and resources and decelerate the demand growth towards a sustainable energy system. All of these facts are leading to the proposal of novel approaches to optimize the utilization of energy in different sectors to reduce the customer's total energy costs, demand and greenhouse gas (GHG) emissions while taking into account the end-user preferences. Utilities have implemented Demand Side Management (DSM) and Demand Response (DR) programs to better manage their network, offer better services to their customers, handle the increase in electricity demand, and at the same time increase system reliability and reduce environmental impacts. Smart Grid developments such as information technology, communication infrastructure and smart meters improve the effectiveness and capability of Energy Management Systems (EMSs) and facilitate the development of automated operational decision-making structures for energy systems, thus assisting DSM and DR programs to reach their full potential. The literature review indicates that whereas significant work has been done in DSM and DR in utilities, these works have mostly focused on direct load control of particular loads, and there is a lack of a general framework to consider all types of energy hubs in an integrated Energy Hub Management System (EHMS). In this context, mathematical modeling of energy systems for EMSs, which is the main concern of the present work, plays a critical role. This research proposes mathematical optimization models of energy hubs which can be readily incorporated into EHMS in the context of Smart Grids. The energy hub could be a single or multi-carrier energy system in residential, commercial, agricultural and/or industrial sectors. Therefore, mathematical models for energy hubs in residential, commercial, and agricultural sectors have been developed and are presented and discussed in this thesis. In the residential sector, this research presents mathematical optimization models of residential energy hubs which can be readily incorporated into automated decision making technologies in Smart Grids, and can be solved efficiently in a real-time frame to optimally control all major residential energy loads, storage and production components while properly considering the customer preferences and comfort levels. Mathematical models for major household demand, i.e., fridge, freezer, dishwasher, washer and dryer, stove, water heater, hot tub, and pool pumps, are formulated. Also, mathematical models of other components of a residential energy system including lighting, heating, and air-conditioning are developed, and generic models for solar PV panels and energy storage/generation devices are proposed. The developed mathematical models result in a Mixed Integer Linear Programming (MILP) optimization problem, whose objective is to minimize demand, total costs of electricity and gas, emissions and peak load over the scheduling horizon while considering end-user preferences. The application of this model to a real household are shown to result in savings of up to 20% on energy costs and 50% on peak demand, while maintaining the household owner's desired comfort levels. In the commercial sector, mathematical optimization models of produce storage facilities to optimize the operation of their energy systems are proposed. In the storage facilities, climate control of the storage rooms consumes considerable energy; thus, a mathematical model of storage facilities appropriate for their optimal operation is developed, so that it can be implemented as a supervisory control in existing climate controllers. The proposed model incorporates weather forecasts, electricity price information, and the end-user preferences to optimally operate existing climate control systems in storage facilities. The objective is to minimize total energy costs and demand charges while considering important parameters of storage facilities; in particular, inside temperature and humidity should be kept within acceptable ranges. Effects of uncertainty in electricity price and weather forecast on optimal operation of the storage facilities are studied via Monte-Carlo simulations. The presented simulation results show the effectiveness of the proposed model to reduce total energy costs while maintaining required operational constraints. In the agricultural sector, this work presents mathematical optimization models of greenhouses to optimize the operation of their energy systems. In greenhouses, artificial lighting, CO2 production, and climate control consume considerable energy; thus, a mathematical model of greenhouses appropriate for their optimal operation is developed, so that it can be implemented as a supervisory control in existing greenhouse controllers. The proposed model incorporates weather forecasts, electricity price information, and the end-user preferences to optimally operate existing control systems in greenhouses. The objective is to minimize total energy costs and demand charges while considering important parameters of greenhouses; in particular, inside temperature and humidity, CO2 concentration, and lighting levels should be kept within acceptable ranges. Effects of uncertainty in electricity price and weather forecast on optimal operation of the storage facilities are studied via Monte-Carlo simulations and robust optimization approach. The presented simulation results show the effectiveness of the proposed model to reduce total energy costs while maintaining required operational constraints.

Στην παρούσα εργασία γίνεται προσπάθεια για την περιγραφή των νέων μοντέλων δικτύου ηλεκτρικής ενέργειας που αναμένεται να δώσουν λύσεις στα διάφορα προβλήματα που έχουν κάνει την εμφάνιση τους λόγω της συνεχούς αύξησης στη ζήτηση ηλεκτρικής ενέργειας. Βασισμένα στην αξιοποίηση των Ανανεώσιμων Πηγών Ενέργειας, τα ΜικροΔίκτυα και κατ’ επέκταση τα Έξυπνα Δίκτυα θεωρούνται οι αντικαταστάτες του παραδοσιακού κεντρικά ελεγχόμενου ηλεκτρικού δικτύου, κάνοντας χρήση των πλεονεκτημάτων της Διεσπαρμένης Παραγωγής. Έπειτα από την αναφορά στο σημαντικό ρόλο των Ανανεώσιμων Πηγών Ενέργειας, περιγράφονται αναλυτικά οι έννοιες της Διεσπαρμένης Παραγωγής, του ΜικροΔικτύου και του Έξυπνου Δικτύου. Οι νέοι αυτοί όροι έχουν ήδη αρχίσει να εισέρχονται στην πραγματικότητα του ηλεκτρικού δικτύου, καθώς υπάρχουν ήδη χρονοδιαγράμματα που επιβάλουν την επιτακτική χρήση των Ανανεώσιμων Πηγών Ενέργειας από τα κράτη, σε μια προσπάθεια να μειωθούν οι εκπομπές των αερίων του θερμοκηπίου. Οι συνεχώς εξελισσόμενες τεχνολογίες που σχετίζονται με τα νέα πρότυπα του ηλεκτρικού δικτύου παρουσιάζονται επίσης. Είναι πολύ σημαντικό οι τεχνολογίες αυτές να αναπτυχθούν όσο το δυνατόν περισσότερο, ώστε να συμβάλλουν στην άμεση, αποδοτική και οικονομικά ωφέλιμη χρήση της Διεσπαρμένης Παραγωγής και την ομαλή και ασφαλή μετάβαση προς τα Έξυπνα Δίκτυα. Στη συνέχεια γίνεται περιγραφή κάποιων μεθόδων ελέγχου των ΜικροΔικτύων και των βασικών μονάδων που το απαρτίζουν. Παρουσιάζονται η λειτουργία του ΜικροΔικτύου όταν λειτουργεί σε απομόνωση από το υπόλοιπο βασικό δίκτυο και σε σύνδεση με αυτό, καθώς οι επιπτώσεις προγραμματισμένων και μη αποσυνδέσεων από τον βασικό κορμό του δικτύου. Τέλος, βασικό κομμάτι της εργασίας αυτής αποτελεί η προσομοίωση κάποιων βασικών μονάδων του ΜικροΔικτύου, και πιο συγκεκριμένα του Μικροστροβίλου και του Ολοκληρωμένου Συστήματος Κυψελών Καυσίμου Στερεού Οξειδίου. Τα αποτελέσματα των προσομοιώσεων αυτών παρουσιάζονται και αναλύονται για την αξιολόγηση της χρήσης τους και της σπουδαιότητάς τους σε συγκεκριμένες εφαρμογές. / In the present work we make an effort to describe the new models of electric networks that are expected to give solutions in the various problems that have made their appearance due to the continuous increase in the demand of electric energy. Based in the exploitation of Renewable Sources of Energy, MicroGrids, and as a result the SmartGrids are considered to be the substitutes of traditional central-controlled electric network, making use of the advantages of Distributed Generation. After the quick reference of the important role of Renewable Sources of Energy, the terms of Distributed Generation, MicroGrid and SmartGrid are described analytically . This new terms have already begun to enter the reality of the electric network, as timetables that impose the imperative use of Renewable Sources of Energy already exist,in an effort decrease the emissions of greenhouse gases.The continuously evolving technologies that are related with the new models of electric network are also presented. It is very important that these technologies are developed as much as possible, so that they contribute in a direct, efficient and economically beneficial use of Distributed Generation and the smooth and sure transition towards the SmartGrids. Afterwards we describe certain methods of control of MicroGrids and basic units that compose them. The operation of MicroGrid when it functions in isolation from the basic network and in connection with this is described.Finally, the simulations of certain basic units of Microgrids are described, focusing on Micorturbine and Solid Oxide Fuel Cell system. The results of these simulations are presented and analyzed for the evaluation of their use and their importance in certainapplications.

Orientador: Alexandre Cezar Rodrigues da Silva / Resumo: A simulação de ambientes computacionais é uma das principais técnicas para estudo de protocolos, seu comportamento em redes de computadores e análise da segurança da informação. O acesso a ambientes reais para simulação de smart grids está restrito a poucas universidades e empresas assim como existem poucas ferramentas disponíveis para sua simulação computacional, o que dificulta a realização de pesquisas nesta linha. Neste trabalho objetiva-se a configuração de um ambiente para simulação do protocolo DNP3 utilizando exclusivamente ferramentas open source, utilizando-se técnicas de segurança ofensiva para realizar ataques a rede e então validar o comportamento da simulação e por fim realizar a integração do ambiente de simulação com equipamentos reais. Para isso, foi desenvolvido um testbed virtual através da integração e configuração de diversas ferramentas e softwares open source e posteriormente utilizados os equipamentos do Laboratório de Proteção do Campus III na UNESP de Ilha Solteira, expandindo as funcionalidades do simulador e obtendo um testbed misto com resultados promissores em todos os testes realizados. / Mestre

Redes elétricas desempenham um papel fundamental no que tange à distribuição de energia elétrica. Entretanto, as redes elétricas convencionais são muito antigas, apresentando uma série de deficiências e inseguranças. Neste cenário surgem as redes elétricas inteligentes, mais conhecidas como smart grids. Smart grids são uma evolução para as redes elétricas tradicionais, apresentando como grande diferencial a presença intensiva de tecnologia de ponta para monitorar cada elemento que a compõe. Uma das principais características de smart grids é seu fluxo bidirecional de energia e informação, que permite a qualquer elemento tanto consumir quanto fornecer energia para a rede, seja um aerogerador ou mesmo uma residência. Tal característica vai de encontro à necessidade de se distribuir a produção energética, tornando-a mais robusta e tolerante a falhas. Uma tecnologia que surgiu em meio ao desenvolvimento de smart grids denomina-se Veículo-Para-Rede (V2G, do inglês Vehicle-To-Grid). Através de sessões V2G, veículos elétricos (EVs, em inglês electric vehicles) podem vender a energia de suas baterias para a rede, obtendo lucro com este procedimento. Existem duas vantagens nesta tecnologia. Por um lado, proprietários de EVs podem obter lucro com a venda de energia, reduzindo os custos de se manter seu veículo. Por outro lado, a rede como um todo se beneficia, pois as baterias podem ser utilizadas para aumentar a estabilidade da rede. Entretanto, para que estas vantagens sejam expressivas, é necessário utilizar-se de mecanismos para aumentar a eficiência do processo V2G, uma vez que baterias são muito caras. Uma alternativa que tem sido muito explorada é a formação de coalizões entre os EVs. A proposta deste trabalho é utilizar informações sobre o domínio de smart grids de modo a impor restrições no processo de formação de coalizões de EVs, visando à redução do espaço de busca de estruturas de coalizão. Especificamente, estabelece-se a distância máxima que pode haver entre dois EVs de uma mesma coalizão, através da qual é possível identificar e podar porções inválidas do espaço de busca. Para tanto, é proposto o algoritmo CPCSG, capaz de identificar restrições entre os EVs e de podar o espaço de busca. A abordagem proposta pode ser utilizada em conjunto com algoritmos de geração de estruturas de coalizão para torná-los mais rápidos e eficientes. Com base em experimentos, percebe-se que a abordagem proposta proporciona um ganho notável de desempenho e uma redução expressiva no uso de memória em relação a outros algoritmos para geração de estruturas de coalizão. Em geral, quanto mais restritiva a rede e quanto maior o número de agentes, maior será o percentual do espaço de busca passível de ser podado. Resultados mostram, ainda, que quando comparada com outros algoritmos de geração de estruturas de coalizão, a técnica proposta chega a superar o tempo dos demais em diversas ordens de magnitude. / Electric grids play a key role in the energy distribution process. However, conventional grids are very old, which causes the onset of weaknesses and uncertainties. In such a scenario the smart grid concept arises. Smart grids are an evolution to the ageing electric grids, whose major breakthrough is the intensive use of technology to monitor every element that comprises it. One of the main features of smart grids is its bi-directional flow of electricity and information, which allows any element to consume and even supply energy to the grid, regardless of being a wind turbine or even a residence. Such a characteristic meets the need to make the energy production more distributed, making it more robust and fault tolerant. Amidst the development of smart grids emerged the concept of Vehicle-To-Grid (V2G). Through V2G sessions, electric vehicles (EVs) can sell the surplus energy of their batteries to the grid, making a profit. Two advantages arise from this technology. First, EVs’ owners can make a profit from the sale of energy, reducing their vehicles’ maintenance cost. Second, the network as a whole is benefited as batteries could be used to increase the network stability. However, in order to benefit from such advantages, it is necessary the use mechanisms to increase the efficiency of the V2G process, since batteries are very expensive. One way that has been explored is the coalition formation among EVs. The proposal of this work is to use smart grids’ domain information to impose constraints on the coalition formation process in order to reduce the coalition structures’ search space. Specifically, we define a maximum distance that can exist between two EVs of a given coalition, through which it is possible to identify and prune invalid portions of the search space. To this end, we propose the CPCSG algorithm, which has the capability of identifying constraints among EVs and pruning the search space. The proposed approach can be used together with coalition structure generation algorithms to make them faster and more efficient. Based on experiments, it can be seen that our approach provides a noticeable performance gain and a significant memory usage reduction compared to other coalition structure generation algorithms. In general, the more restrictive the grid and the greater the number of agents, the greater the percentage of the search space that can be pruned. Results also show that when compared with other coalition structure generation algorithms, the proposed technique is able to overcome the other in time by several orders of magnitude.

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2016. / Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2016-08-22T13:47:09Z No. of bitstreams: 1 2016_LorenaMeloSilva.PDF: 3377492 bytes, checksum: 428988e6ca5af4ddc218ef280ee5100e (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-11-01T10:23:10Z (GMT) No. of bitstreams: 1 2016_LorenaMeloSilva.PDF: 3377492 bytes, checksum: 428988e6ca5af4ddc218ef280ee5100e (MD5) / Made available in DSpace on 2016-11-01T10:23:10Z (GMT). No. of bitstreams: 1 2016_LorenaMeloSilva.PDF: 3377492 bytes, checksum: 428988e6ca5af4ddc218ef280ee5100e (MD5) / O Setor Elétrico Brasileiro - SEB é extremamente complexo, com uma extensa cadeia de valor interligada por meio do Sistema Interligado Nacional – SIN. Em especial durante os últimos anos, tal complexidade aumentou com o crescimento da demanda, a inserção de novas fontes de geração, e o envelhecimento dos sistemas existentes. Nesse contexto, que também se verifica no restante do mundo, em diferentes escalas, as Redes Elétricas Inteligentes, ou Smart Grids, surgem como uma forma de proporcionar à sociedade maior segurança de abastecimento, possibilitar a resposta por parte da demanda, a melhora dos índices de qualidade pelo rápido reconhecimento e restabelecimento do sistema diante de distúrbios e falhas, maior eficiência nas instalações de transmissão e distribuição, redução de perdas, dentre tantas outras. O objetivo deste trabalho é aprimorar as análises acerca dos custos e benefícios decorrentes de projetos em Redes Elétricas Inteligentes a partir da ótica das características de concessões de distribuição escolhidas, pensando na implantação das Redes Elétricas Inteligentes não como um fator acessório aos sistemas atuais, mas sim de forma ampla e com o objetivo de mudar o relacionamento entre o consumidor e os sistemas elétricos atuais. A partir dos resultados, serão identificados conjuntos de características importantes para a viabilidade da implantação, configurando ferramenta acessória para a decisão de investimento em Redes Elétricas Inteligentes. __________________________________________________________________________________________________ ABSTRACT / The electrical energy sector in Brazil is extremely complex, with an extensive value chain interconnected by the national grid. Especially during the recent years, this complexity has increased with the growth of energy demand, the introduction of new generation sources, and the aging of existing systems. In this context, which is also verified in other countries in different scales, the Smart Grids arise as a way to provide society a greater supply reliability, enable the response of the consumer, the improvement of energy quality through fast recognition of disturbances and system restoration after failures, greater efficiency in transmission and distribution facilities, reducing of losses, among other benefits. The objective of this work is to improve the cost and benefits analysis for Smart Grids projects by the perspective of electric power distribution utilities characteristics, in order to promote the implementation of Smart Grids not as an auxiliary factor to nowadays electrical systems, but as a wide project, in order to change the way the consumer interacts with the energy sector, in opposition with the current situation. The results obtained will indicate the most significant features to the viability of the implementation, by setting an ancillary tool for investment decision in Smart Grids.

Orientador: Luis Carlos Origa de Oliveira / Resumo: O gerenciamento econômico de transformadores de distribuição é de fundamental importância no planejamento econômico das concessionárias de energia, pois estão presentes em grande quantidade no sistema elétrico. No novo conceito de redes inteligentes, novas considerações sobre as perdas nos transformadores devem ser feitas e outras possibilidades de gerenciamento podem ser exploradas. A primeira afirmação se deve ao fato do aumento da não-linearidade no perfil da carga no transformador, proveniente do aumento de cargas eletrônicas e de unidades de geração distribuída que utilizam conversores eletrônicos para conexão com a rede. A segunda afirmação é justificada pela infraestrutura avançada de medição presente nas redes inteligentes, o que possibilita acesso remoto e dinâmico a uma maior quantidade de informações fundamentais para análise das condições operacionais dos transformadores. Este trabalho analisa como utilizar um sistema de monitoramento em redes inteligentes em conjunto com o cálculo de perdas para identificação de transformadores sobrecarregados. Além disso, com o conhecimento das curvas de carga diária, dos índices econômicos vigentes, desenvolveu-se um aplicativo para gerenciamento de unidades transformadoras em operação, ferramenta esta que poderá ser utilizada no sistema de gestão de ativos das concessionárias. / Doutor