abstract: Transmission expansion planning (TEP) is a complex decision making process that requires comprehensive analysis to determine the time, location, and number of electric power transmission facilities that are needed in the future power grid. This dissertation investigates the topic of solving TEP problems for large power systems. The dissertation can be divided into two parts. The first part of this dissertation focuses on developing a more accurate network model for TEP study. First, a mixed-integer linear programming (MILP) based TEP model is proposed for solving multi-stage TEP problems. Compared with previous work, the proposed approach reduces the number of variables and constraints needed and improves the computational efficiency significantly. Second, the AC power flow model is applied to TEP models. Relaxations and reformulations are proposed to make the AC model based TEP problem solvable. Third, a convexified AC network model is proposed for TEP studies with reactive power and off-nominal bus voltage magnitudes included in the model. A MILP-based loss model and its relaxations are also investigated. The second part of this dissertation investigates the uncertainty modeling issues in the TEP problem. A two-stage stochastic TEP model is proposed and decomposition algorithms based on the L-shaped method and progressive hedging (PH) are developed to solve the stochastic model. Results indicate that the stochastic TEP model can give a more accurate estimation of the annual operating cost as compared to the deterministic TEP model which focuses only on the peak load. / Dissertation/Thesis / Ph.D. Electrical Engineering 2013

abstract: This thesis focuses on developing an integrated transmission and distribution framework that couples the two sub-systems together with due consideration to conventional demand flexibility. The proposed framework ensures accurate representation of the system resources and the network conditions when modeling the distribution system in the transmission OPF and vice-versa. It is further used to develop an accurate pricing mechanism (Distribution-based Location Marginal Pricing), which is reflective of the moment-to-moment costs of generating and delivering electrical energy, for the distribution system. By accurately modeling the two sub-systems, we can improve the economic efficiency and the system reliability, as the price sensitive resources can be controlled to behave in a way that benefits the power system as a whole. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2014

Dans un contexte de hausse de prix des énergies et de protection du climat, la thèse s’intéresse à l’investissement dans des capacités électrique, en particulier dans le nucléaire. Partant de l’hypothèse où la Génération IV de réacteurs nucléaires serait prête autour de 2040 pour un déploiement industriel, l’objet de la thèse est d'analyser les conditions d'investissement et de développement de capacités de production d'électricité en France et en Europe à cet horizon, afin d’évaluer les perspectives de développement du nucléaire sur le marché électrique européen et le potentiel développement de la Génération IV. Pour ce faire, le travail de recherche nécessite de prendre du recul et d’étudier de manière générale, en prenant en compte toutes les technologies de production d’électricité, les mécanismes entrant en jeu dans le choix d’investissement de l’électricien lorsqu’il s’agit de renouveler ou d’étendre son parc de production. L’approche économique classique basant généralement le choix de l’investisseur sur une rationalité économique de long terme, elle ne permet pas d’expliquer les choix effectifs constatés dans les mix électriques d’un pays à l’autre. L’objectif de cette thèse est d’identifier les déterminants des choix d’investissement dans des capacités électriques et de proposer une approche permettant de décrire le comportement du choix de l’investisseur allant au-delà du critère classique de rationalité économique de long terme. Une approche pluridisciplinaire a été adoptée pour répondre à la question posée. Elle combine une analyse historique de l’évolution des déterminants des choix en fonction du contexte, une analyse structurelle permettant d’identifier les scénarios les plus favorables à l’émergence de futurs réacteurs nucléaires, une approche de création de valeur permettant proposant de reproduire les préférences des électriciens en fonction des déterminants, et enfin une approche par la théorie des options réelles pour comparer les compétitivités respectives des futurs réacteurs nucléaires de Génération IV avec celle des réacteurs actuels. Il en résulte que des politiques pro-nucléaires seules ne seraient pas suffisantes, mais que seule une politique climatique forte permettrait réellement l’émergence des réacteurs sur le marché. De fort progrès technologiques dans le domaine des renouvelables ne sont pas antinomiques avec le développement de nouveaux réacteurs. A un niveau international, cette analyse pourrait être élargie en prenant en compte les déterminants spécifiques aux autres régions du monde, comme la forte croissance de la demande en électricité des pays émergents. / In a context of growing energy prices and climate change mitigation, the thesis addresses the issues of investments in power generation capacities and in particular nuclear capacities. Given that the Generation IV of nuclear reactors is supposed to be ready in 2040 for industrial deployment, the purpose of the thesis is to study the conditions for electricity investments in France and Europe within this horizon, in order to assess development perspectives for nuclear energy and for potential emergence of Generation IV on the European market. To do so, it is necessary to study the mechanisms at stake in investment choices taking into account all power generating technologies. Economic theory usually bases the choice on long-term economic rationality, which does not allow explain the actual choices observed in European electricity mix. The objective of the research work is thus to identify investment choice drivers and to propose an approach describing the behavior of investors in a more realistic way. A multidisciplinary approach was adopted to explore the question. It combines a historical analysis of drivers evolution according to historical context, a structural analysis of these drivers to identify favorable scenarios for future nuclear reactors, a value creation approach to replicate investors’ preferences in those scenarios, and last, a value option approach focusing on nuclear technologies and comparing competitiveness of Generation IV reactors with current reactors. As a result, only strong climate policy combined to government support to nuclear energy could allow industrial development of Generation IV, while high progress of renewables does not lessen the attractiveness of nuclear energy.On a international level, such analysis could be broaden by taking into account the drivers specific to each area of the world, such as highly growing demand in developing countries.

L’analyse de stabilité en régime transitoire du réseau de transport électrique permet de contrôler le bon retour au régime stationnaire du système soumis à une perturbation. Cette analyse systématique des systèmes de réseaux en développement permet notamment d’optimiser la production et la consommation de l’énergie électrique, et de protéger les équipements tels que les centrales électriques, les transformateurs, les lignes haute-tension, etc. Afin d’améliorer la stabilité, la robustesse et la viabilité de ces systèmes, la tendance est à l’interconnexion des réseaux de transport régionaux et nationaux, et ainsi, au développement et à l’analyse de systèmes toujours plus grands. Le problème de stabilité électrique peut être simulé numériquement grâce à l’intégration d’un système d’équations algébro-différentielles non-linéaire et raide. Lorsque le problème traité est très grand, la simulation numérique devient très coûteuse en temps de calcul et ralentit considérablement le travail des professionnels du secteur. Cette thèse a pour but de proposer, d’étudier, et de développer des méthodes innovantes de calcul parallèle pour la résolution des systèmes d’équations différentielles issus de la simulation de grands réseaux électriques tel que le réseau européen. Dans ce manuscrit, on livre une analyse des propriétés de ces systèmes assez spécifiques : creux, irréguliers, non-linéaires, raides et hétérogènes. On discute notamment de la structure particulière de ces systèmes qui rend attrayante l’application d’une méthode de décomposition de domaine. On étudie ainsi plusieurs méthodes de parallélisation en espace : la parallélisation fine de chaque opération coûteuse, la résolution du système non-linéaire par décomposition en sous-réseaux faiblement couplés, d’abord sur chaque étape d’intégration, puis par méthode de relaxation d’ondes. On aborde aussi la parallélisation en temps de type algorithme Pararéel ainsi qu’une méthode parallèle espace-temps bénéficiant des propriétés couplées des méthodes de relaxation d’ondes et de Pararéel. Dans ces travaux, nous proposons des méthodes assurant la convergence rapide des méthodes de décomposition de domaine quel que soit le nombre de sous-domaines et de processeurs employés. Nous introduisons pour cela des techniques de préconditionnement en espace adéquates afin d’améliorer la scalabilité des méthodes de parallélisation envisagées. / Power system transient stability analysis enables to control the return to equilibrium of the system subjected to a disturbance. This systematic analysis of developing transport networks allows to optimize the production and the consumption of electric power and to protect the equipments such as power plants, transformers, highvoltage lines and so on. In order to improve the stability, the robustness, and the sustainability of these systems, a worldwide trend is to interconnect regional and national transport networks. This leads to analyze ever larger systems. The power-stability problem can be numerically simulated owing to the integration of a differential-algebraic system which is nonlinear and stiff. When considering a very large problem, numerical simulation is very time consuming and significantly slows down the work of professionals. This thesis aims at studying innovative parallel computing methods for the resolution of differential systems arising from the transient stability analysis of large power systems such as the European Transport Network. In this manuscript, we first deliver an analysis of the properties of these rather specific systems: sparse, irregular, nonlinear, stiff, and heterogeneous. We discuss the particular structure of these systems making the application of a domain decomposition method interesting. Thus, we study several space parallelization methods: the fine parallelization of each costly tasks, the resolution of the nonlinear system by decomposition into weakly coupled subnetworks, first on each integration step separately, and then by waveform relaxation method. We also address the time parallelization with a Parareal-based algorithm and a space-time parallel method which benefits from the coupled properties of waveform relaxation and Parareal methods. In this work, we focus on methods which ensure a fast convergence of domain decomposition methods whatever the number of subdomains/processors used. In order to achieve such a goal, we introduce space preconditioning techniques to improve the scalability of the parallelization methods considered.

Este trabalho apresenta o desenvolvimento de um algoritmo baseado na modelagem do sistema de transmissão por meio de equações diferenciais, formuladas através dos parâmetros resistência e indutância da linha de transmissão a ser protegida. Nesta abordagem não é necessário que a entrada do algoritmo seja puramente senoidal, admitindo-se a presença de harmônicos e componentes CC presentes na falta como parte da solução do problema. Utilizou-se o software ATP para a modelagem do sistema elétrico estudado e a obtenção do conjunto de dados para análise e testes, permitindo-se a representação detalhada da linha de transmissão por meio das características dos condutores e suas respectivas disposições geométricas nas torres de transmissão, além da modelagem das diversas manobras e defeitos que os afetam, buscando-se uma aproximação com uma situação real. Com relação ao uso direto das equações diferenciais para a tarefa de proteção das linhas, constatou-se que sua aplicação não produz uma estimativa aceitável para ser usada em relés digitais por possuírem convergência em tempos normalmente superiores a dois ciclos. Assim, foi feita uma filtragem das respostas do algoritmo, proporcionando-se um diagnóstico mais rápido das estimativas. Para isso foi usado um filtro de mediana de 5ª ordem para o cálculo da localização da falta. Para todos os tipos de falta testados, a estimativa da localização da falta com o uso do referido filtro mostrou-se altamente satisfatória para a finalidade de proteção, convergindo em menos de um ciclo e meio de pós-falta, após a filtragem das estimativas, imprimindo maior velocidade de resposta para os relés digitais. / The present work shows the development of an algorithm based on the modeling of the transmission system utilizing differential equations. The differential equation for the line is solved having its resistance and inductance as parameters. In this approach there is no need for the algorithm inputs to be pure sinusoidal, allowing the presence of harmonic and DC components in the line as a part of the solution to the problem. The software ATP was utilized for the modeling of the electric system under study as well as data collection for analysis and tests. This representation allowed a detailed representation of the transmission line through the characteristics of the conductors and its geometrical disposition in the transmission towers, as well as the simulation of faults that usually affect the electric system, reproducing a realistic situation. The direct use of differential equations do not give an acceptable estimation as far as digital relays are concerned because they have convergence times over two cycles. In this sense, a 5th order median filter was utilized, providing faster diagnosis for the fault location estimation. The estimation of the fault location has proved to be a coherent criteria for the algorithm. For the fault types tested, the estimation for the fault location utilizing line parameters has shown itself highly satisfactory for protection purposes. This work has shown that the algorithm oulputs converge in less than 1 and a half cycles afler the fault occurrence, presenting a much faster response for digital relays.

This work proposes a model for the HVDC transmission system of the Madeira River Complex, which is developed using PSCAD/EMTDC and based on the design provided by the Energy Research Company (EPE) during the granting concession stage. The implemented model is evaluated by comparing the simulation results and actual data regarding events that occurred in the National Interconnected System (SIN) involving the complex. The Madeira River HVDC system is rated at 7,100 MW, being responsible for transmitting the power generated by the hydropower plants of Santo AntÃnio and Jirau, which are close to the city of Porto Velho, to local load centers and southeastern Brazil, thus reaching the Araraquara substation in the state of SÃo Paulo through two 2,350 km lines. The system consists of two back-to-back (antiparallel) blocks rated at 400 MW each using capacitor-commutated converter stations in order to supply the load comprising the states of RondÃnia and Acre, and also two bipoles of 3,150 MW each, which are constituted by 12-pulse line-commutated current source converters so that power can be transmitted to southeastern Brazil. The results of comparison between actual data and the simulation tests have shown that the percentage difference between the evaluated quantities are within acceptable limits, while it can be concluded that the proposed model is properly validated. / Este trabalho propÃe um modelo do sistema de transmissÃo HVDC do Complexo do Rio Madeira, desenvolvido no ambiente PSCAD/EMTDC e baseado no projeto disponibilizado pela Empresa de Pesquisa EnergÃtica - EPE na fase de concessÃo das instalaÃÃes. O modelo construÃdo à avaliado por meio da comparaÃÃo entre os resultados de simulaÃÃo e os dados reais de ocorrÃncias no Sistema Interligado Nacional - SIN que envolveram o complexo. O HVDC do Rio Madeira possui capacidade total de conversÃo de 7.100 MW, e transporta a energia gerada nas usinas hidroelÃtricas de Santo AntÃnio e Jirau, prÃximas a Porto Velho, para centros de carga locais e para o sudeste do Brasil, chegando à subestaÃÃo Araraquara, no estado de SÃo Paulo, atravÃs de duas linhas em corrente contÃnua de 2.350 km de extensÃo. O sistema à composto por dois blocos back-to-back (anti-paralelo) de 400 MW cada, com estaÃÃes conversoras comutadas por capacitores, para atender as cargas dos estados de RondÃnia e Acre, e dois elos bipolares de 3.150 MW cada, constituÃdos de conversores fonte de corrente de 12 pulsos com comutaÃÃo natural de linha, para transmissÃo de energia para o sudeste do paÃs. Os resultados da comparaÃÃo entre os dados reais e a simulaÃÃo mostraram que as diferenÃas percentuais entre grandezas avaliadas se mantiveram dentro de limites satisfatÃrios, podendo-se concluir que o modelo construÃdo foi considerado validado.

Dentre as fontes de energia renováveis utilizadas para geração de energia elétrica a que mais se destaca atualmente e a energia eólica. 0 crescente índice de penetração da geração eólica na matriz energética dos sistemas de potencia impõe a necessidade da revisão de conceitos anteriormente estabelecidos sobre a estabilidade de sistemas de potencia, uma vez que ainda não e perfeitamente compreendida a influencia de uma maior integração deste recurso no comportamento dos sistemas de potencia. Este trabalho tem como foco o estudo da estabilidade de sistemas com aerogeradores de velocidade fixa equipados com geradores de indução de rotor em gaiola. E estudada a estabilidade angular de um sistema de geração eólica equipado com aerogeradores desta natureza. O problema da estabilidade foi decomposto em três partes: estabilidade estática, estabilidade dinâmica e estabilidade transitória. São definidos os modelos dos componentes do aerogerador para cada um dos estudos realizados. A topologia adotada á a máquina Barramento Infinito (MBI), na qual o restante do sistema de potência a representado pelo seu equivalente de Thevenin. Esta topologia típica de analise de estabilidade de sistemas de potencia e adotada por permitir a obtenção de resultados analíticos para as analises estática e dinâmica. A analise transitória se dá através de simulações computacionais. A fim de manter um caráter mais geral para os resultados as simulações são realizados com três aerogeradores de características distintas. Os resultados obtidos permitem uma melhor compreensão da influencia sobre a estabilidade do sistema de geração eólica dos parâmetros de rede do sistema de potencia como: potencia de curto-circuito do ponto de conexão comum com o sistema de potencia, relação X/R da linha de transmissão e do capacitor de compensação de fator de potencia. / Among the renewable energy sources used to generate electric power one of the most important at this time is the wind power. The growing penetration index of wind power in the power systems energetic matrix leads to the necessity of a reevaluation of the concepts previously established about the stability of power systems, since the influence of a major integration of this resource in the behavior of power systems is not perfectly understood. This work focuses on the stability study of wind power systems equiped with fixed-speed squirrel-cage induction generators. The angular stability of a wind generation system equipped with wind generators of this nature is studied. The stability problem was decomposed in three parts: static stability, dynamic stability and transient stability. The models of the components of the wind generator are defined for each of the studies. The considered topology was an Induction Generator Infinite Bus System (IBM), where the rest of the power system is represented by it’s Thévenin equivalent. This is a typical topology in power systems stability analysis and is adopted in this work aiming at obtaining analytical and general stability results. The transient analysis is performed by computer simulations. In order to provide more generatily to the stability results, all simulations are conducted with three wind generators with distinct characteristics. The obtained results allow a better comprehension about the influence, on the stability of wind power systems, of power system network parameters as: short-circuit capacity of the common connection point with the power system, the X/R relation of the transmission line and the power factor compensation capacitor.

Orientador: Sergio Valdir Bajay / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-14T08:34:32Z (GMT). No. of bitstreams: 1 Sales_AlexandraLucio_M.pdf: 998470 bytes, checksum: 988d4fabf4b39a1195f5560161910d75 (MD5) Previous issue date: 2007 / Resumo Neste trabalho é feita uma análise do planejamento da expansão do parque gerador de energia elétrica do Brasil, a partir da caracterização do cenário atual do setor elétrico brasileiro. Procurou-se resgatar o histórico dos estudos de médio e de longo prazos, realizados desde a década de 1960 e que serviram de premissas para expansão do setor. O planejamento de sistemas hidrotérmicos de potência pode ser representado matematicamente por uma função objetivo, que, sujeito à certas restrições, sinalize uma operação ótima desses sistemas e suas necessidades de expansão. Diversos tipos de modelos computacionais podem ser utilizados como valiosas ferramentas de auxílio à tomada de decisão na solução deste problema. Este trabalho discute as principais estratégias de solução que vêm sendo aplicadas neste contexto. Em uma outra parte deste trabalho, foram analisadas diversas bases de dados, nacionais e internacionais, que disponibilizam informações a respeito de custos e de tendências tecnológicas para a geração de energia elétrica. A partir destas análises, foi feito um levantamento dos parâmetros que formam o custo unitário de geração, que permitiu a formulação de três cenários: "baixo", "referência" e "alto", que simulam, através de planilhas econômico-financeiras, condições de formação de baixos custos unitários de geração, custos mais prováveis e altos custos unitários de geração, respectivamente. Por fim, são analisados os resultados obtidos da planilha sob o aspecto da competitividade das tecnologias que complementam o parque hidráulico brasileiro. O estudo desenvolvido neste trabalho mostra a importância dos parâmetros econômico-financeiros e das políticas energéticas adotadas para o setor, dado que estes afetam diretamente o custo de geração e, conseqüentemente, os preços praticados no mercado de energia elétrica. / Abstract: An evaluation is carried out in this thesis about medium and long-term generation planning in the Brazilian electric power system, since the 1960's. Planning of hydrothermal power systems can be represented mathematically by an objective function, which, subject to certain constraints, indicates an optimal operation of these systems and their expansion needs. Several types of computer models can be used as valuable tools in the decisions making process involved in the solution of this problem. The main solution strategies which have been applied so far are discussed here. In another part of this thesis, several data basis, both national and international, providing information about electricity generation costs and technological trends, have been assessed. From these analysis, the main parameters that form the generation unit cost were identified, allowing the formulation of three scenarios - "low", "reference" and "high", which simulate, through economic-financial data sheets, low, more likely and high unit costs, respectively. The results obtained from the data sheets provide valuable insights about the competitive positions of the technologies that complement hydro power in Brazil. This thesis highlights the importance of economic-financial parameters and the public policies adopted for the power sector, since they affect directly generation unit cost and, consequently, the prices practiced in the electricity market. / Mestrado / Mestre em Planejamento de Sistemas Energéticos

To integrate large volumes of renewables and use electricity more efficiently, many industrial trials are on-going around the world that aim to realize decentralized or hierarchical control of renewable and distributed energy resources, flexible loads and monitoring devices. As the cost and complexity involved in the centralized communications and control infrastructure may be prohibitive in controlling millions of these distributed energy resources and devices, distributed optimization methods are expected to become much more prevalent in the operation of future electric power systems, as they have the potential to address this challenge and can be applied to various applications such as optimal power ow, state estimation, voltage control, and many others. While many distributed optimization algorithms are developed mathematically, little effort has been reported so far on how these methods should actually be implemented in real-world large-scale systems. The challenges associated with this include identifying how to decompose the overall optimization problem, what communication infrastructures can support the information exchange among subproblems, and whether to coordinate the updates of the subproblems in a synchronous or asynchronous manner. This research is dedicated to developing mathematical tools to address these issues, particularly for solving the non-convex optimal power flow problem. As the first part of this thesis, we develop a partitioning method that defines the boundaries of regions when applying distributed algorithms to a power system. This partitioning method quantifies the computational couplings among the buses and groups the buses with large couplings into one region. Through numerical experiments, we show that the developed spectral partitioning approach is the key to achieving fast convergence of distributed optimization algorithms on large-scale systems. After the partitioning of the system is defined, one needs to determine whether the communications among neighboring regions are supported. Therefore, as the second part of this thesis, we propose models for centralized and distributed communications infrastructures and study the impact of communication delays on the efficiency of distributed optimization algorithms through network simulations. Our findings suggest that the centralized communications infrastructure can be prohibitive for distributed optimization and cost-effective migration paths to a more distributed communications infrastructure are necessary. As the sizes and complexities of subproblems and communication delays are generally heterogeneous, synchronous distributed algorithms can be inefficient as they require waiting for the slowest region in the system. Hence, as the third part of this thesis, we develop an asynchronous distributed optimization method and show its convergence for the considered optimal power flow problem. We further study the impact of parameter tuning, system partitioning and communication delays on the proposed asynchronous method and compare its practical performance with its synchronous counterpart. Simulation results indicate that the asynchronous approach can be more efficient with proper partitioning and parameter settings on large-scale systems. The outcome of this research provides important insights into how existing hardware and software solutions for Energy Management Systems in the power grid can be used or need to be extended for deploying distributed optimization methods, which establishes the interconnection between theoretical studies of distributed algorithms and their practical implementation. As the evolution towards a more distributed control architecture is already taking place in many utility networks, the approaches proposed in this thesis provide important tools and a methodology for adopting distributed optimization in power systems.

The interdependencies that exist within and between infrastructures can cause unexpected system properties to emerge when their components fail due to large disruptions. As witnessed following emergencies such as Hurricane Katrina, the complexities of these interdependencies make it very difficult to effectively recover infrastructure because of the challenges they create in prioritizing the most critical components for repair. The Joint Infrastructure Interdependencies Research Program was initiated by Public Safety Canada (PSC) and the Natural Sciences and Engineering Research Council of Canada (NSERC) in 2005 to research methods for remedying this problem. As a part of this research, the University of British Columbia (UBC) is developing an infrastructure interdependency simulator, named I2Sim, to simulate disasters and develop strategies for dealing with emergencies. Part of this development is to construct a model of the UBC electrical distribution system and interface it with I2Sim. In this research, a general methodology for such a model is presented, which employs an off-the-shelf powerflow modeling tool. In addition, a model of the UBC information technology infrastructure is developed to provide a second infrastructure model to demonstrate the electrical model's usefulness in multi-infrastructure disaster recovery simulations. Simulations with these models have shown that the recovery of this two-infrastructure system can be carried out more effectively following an earthquake if both infrastructures are considered together in the repair approach, rather than individually. This difference was on the order of thirty percent. To extend this research from electrical distribution systems to electrical bulk systems, an interdependency model of the British Columbia Transmission Corporation bulk power network and its communications system was also developed, along with a post-blackout restoration procedure. Using these, simulations of a post-blackout recovery were carried out to study the level of risk that communications outages may pose to the electrical network's recovery. These simulations revealed a correlation between restoration time and the number of communication points lost. This research also demonstrates there is value in combining the results of such simulations with risk evaluation tools. Together these results provided a clearer indication of where vulnerabilities exist. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate