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Made available in DSpace on 2014-06-11T19:30:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-04-23Bitstream added on 2014-06-13T18:40:59Z : No. of bitstreams: 1 baquero_jff_dr_ilha.pdf: 928776 bytes, checksum: 14beda1a12c4b74205593d8475f64232 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O problema do planejamento de sistemas de distribuição de energia elétrica consiste em determinar as mudanças que precisam ser feitas no sistema visando atender as condições de demanda futura, respeitando os critérios técnicos de operação e segurança, tudo isto sob um mínimo custo econômico (no caso da otimização monoobjetivo). A modelagem do problema de planejamento da expansão de sistemas de distribuição inclui a repotenciação de subestações existentes, a alocação e dimensionamento de novas subestações, o recondutoramento de alimentadores existentes, a construção e seleção do tipo de cabo para alimentadores novos e a seleção da topologia do sistema (reconfiguração). Além disso, o modelo considera que a expansão do sistema pode ser executada em vários estágios, propondo assim uma formulação dinâmica do problema de planejamento. É apresentada neste trabalho uma estratégia de decomposição para dividir o problema no subproblema da seleção das subestações e na solução de problemas de reconfiguração e recondutoramento dependentes. São desenvolvidos algoritmos heurísticos, que combinados com a metaheurística Busca Tabu, permitem uma exploração eficiente do espaço de busca. A estratégia de decomposição mencionada permite o uso da programação paralela, conseguindo diminuir o tempo de processamento. O método proposto é testado usando casos de grande porte da literatura, mostrando um excelente desempenho / The distribution system expansion planning problem consists of to determine the investments that need to be made in the system to meet future demand conditions, satisfying technical criteria for operation and safety, all under a minimum economic cost (in the case of mono-objective optimization). The modeling of the planning problem includes the expansion of existing substations, the allocation and design of new substations, the reconductoring of existent feeders, the selection of the type of conductor for new feeders and the selection of the system topology (reconfiguration). Furthermore, the model assumes that the expansion of the system can be performed in several stages, thus it is proposed dynamic planning problem formulation. In this paper work, it is presented a decomposition strategy to separate the problem into the subproblems of selection of the substations, reconfiguration and selection of the conductor feeders. Heuristic algorithms are developed, which combined with the Tabu Search metaheuristic, allow an efficient exploration of the space of search. The decomposition strategy aforementioned allows the use of parallel programming, achieving reduced processing time. The proposed method is tested using large cases in the literature, showing excellent performance

abstract: This research develops decision support mechanisms for power system operation and planning practices. Contemporary industry practices rely on deterministic approaches to approximate system conditions and handle growing uncertainties from renewable resources. The primary purpose of this research is to identify soft spots of the contemporary industry practices and propose innovative algorithms, methodologies, and tools to improve economics and reliability in power systems. First, this dissertation focuses on transmission thermal constraint relaxation practices. Most system operators employ constraint relaxation practices, which allow certain constraints to be relaxed for penalty prices, in their market models. A proper selection of penalty prices is imperative due to the influence that penalty prices have on generation scheduling and market settlements. However, penalty prices are primarily decided today based on stakeholder negotiations or system operator’s judgments. There is little to no methodology or engineered approach around the determination of these penalty prices. This work proposes new methods that determine the penalty prices for thermal constraint relaxations based on the impact overloading can have on the residual life of the line. This study evaluates the effectiveness of the proposed methods in the short-term operational planning and long-term transmission expansion planning studies. The second part of this dissertation investigates an advanced methodology to handle uncertainties associated with high penetration of renewable resources, which poses new challenges to power system reliability and calls attention to include stochastic modeling within resource scheduling applications. However, the inclusion of stochastic modeling within mathematical programs has been a challenge due to computational complexities. Moreover, market design issues due to the stochastic market environment make it more challenging. Given the importance of reliable and affordable electric power, such a challenge to advance existing deterministic resource scheduling applications is critical. This ongoing and joint research attempts to overcome these hurdles by developing a stochastic look-ahead commitment tool, which is a stand-alone advisory tool. This dissertation contributes to the derivation of a mathematical formulation for the extensive form two-stage stochastic programming model, the utilization of Progressive Hedging decomposition algorithm, and the initial implementation of the Progressive Hedging subproblem along with various heuristic strategies to enhance the computational performance. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2017

A recém-adquirida competitividade pela energia eólica frente a outras fontes alternativas e, até mesmo, convencionais tem sido comemorada pelo setor de energia elétrica. No entanto, a base para essa comparação leva em conta apenas os parâmetros dos investimentos do parque viabilizado, não sendo considerados outros fatores inerentes à inserção da fonte na matriz, como, por exemplo, o aumento do risco ao sistema, investimento necessário à ampliação da Rede Básica para escoamento da energia para o centro de carga e os custos com redespacho de geração, reserva girante e controles do sistema. O maior potencial está concentrado no Nordeste e o maior centro de carga no Sudeste, assim, em caso de exploração intensiva do potencial da fonte, será necessário passar por grandes investimentos em reforços e ampliações da rede básica. A partir desse panorama, busca-se realizar as primeiras análises de sensibilidade sobre a eficiência econômica dos parques eólicos instalados no Nordeste e, ao mesmo tempo, analisar as condições de atendimento da ponta. / The newfound competitiveness in wind power compared to other alternative and even conventional energy sources has been celebrated by the electric power sector. However, the basis for this comparison takes into account only the parameters of the Capex, not considering other factors inherent in the insertion of the source in the array, for example, increase the risk to the system, expansion of the investment necessary for Basic network for transport of energy to the load center and the cost of redispatch generation, spinning reserve, and system controls. The greatest potential is concentrated in the Northeast and the largest load hub in the Southeast, so, in case of intensive exploitation of the potential of the source, large investments in reinforcements and expansions of the grid will be necessary. From this overview, we attempt the firsts sensitivity analysis on the economic efficiency of wind farms in the Northeast and the load peak supply conditions.

Orientador: Rubén Augusto Romero Lázaro / Coorientador: Marcos Julio Rider Flores / Banca: Jose Roberto Sanches Mantovani / Banca: Antonio Padilha Feltrin / Banca: Eduardo Nobuhiro Asada / Banca: Ariovaldo Verandio Garcia / Resumo: O problema do planejamento de sistemas de distribuição de energia elétrica consiste em determinar as mudanças que precisam ser feitas no sistema visando atender as condições de demanda futura, respeitando os critérios técnicos de operação e segurança, tudo isto sob um mínimo custo econômico (no caso da otimização monoobjetivo). A modelagem do problema de planejamento da expansão de sistemas de distribuição inclui a repotenciação de subestações existentes, a alocação e dimensionamento de novas subestações, o recondutoramento de alimentadores existentes, a construção e seleção do tipo de cabo para alimentadores novos e a seleção da topologia do sistema (reconfiguração). Além disso, o modelo considera que a expansão do sistema pode ser executada em vários estágios, propondo assim uma formulação dinâmica do problema de planejamento. É apresentada neste trabalho uma estratégia de decomposição para dividir o problema no subproblema da seleção das subestações e na solução de problemas de reconfiguração e recondutoramento dependentes. São desenvolvidos algoritmos heurísticos, que combinados com a metaheurística Busca Tabu, permitem uma exploração eficiente do espaço de busca. A estratégia de decomposição mencionada permite o uso da programação paralela, conseguindo diminuir o tempo de processamento. O método proposto é testado usando casos de grande porte da literatura, mostrando um excelente desempenho / Abstract: The distribution system expansion planning problem consists of to determine the investments that need to be made in the system to meet future demand conditions, satisfying technical criteria for operation and safety, all under a minimum economic cost (in the case of mono-objective optimization). The modeling of the planning problem includes the expansion of existing substations, the allocation and design of new substations, the reconductoring of existent feeders, the selection of the type of conductor for new feeders and the selection of the system topology (reconfiguration). Furthermore, the model assumes that the expansion of the system can be performed in several stages, thus it is proposed dynamic planning problem formulation. In this paper work, it is presented a decomposition strategy to separate the problem into the subproblems of selection of the substations, reconfiguration and selection of the conductor feeders. Heuristic algorithms are developed, which combined with the Tabu Search metaheuristic, allow an efficient exploration of the space of search. The decomposition strategy aforementioned allows the use of parallel programming, achieving reduced processing time. The proposed method is tested using large cases in the literature, showing excellent performance / Doutor

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This study presents a multi-attribute decision making (MADM) framework in support of strategic resource planning of electric utilities. Study efforts have focused on four technical issues identified to be essentially important to the process of strategic resource development, i.e., decision data expansion, MADM analysis with imprecise information, MADM analysis under uncertainty and screening applications. Main contributions from this study are summarized as follows. First, an automatic learning method is introduced for decision data expansion aiming at reducing the amount of computations involved in the creation of decision database. Test results have shown that the proposed method is feasible, easy to implement, and more accurate than the techniques available in the existing literature. Second, an interval-based MADM methodology is developed, which extends the traditional utility function model with the measure of composite utility variance, accounting for individual errors from inaccurate attribute measurements and inconsistent priority judgments. This enhanced decision approach would help the decision-maker (DM) gain insight into how the imprecise data may affect the choice toward the best solution and how a range of acceptable alternatives may be identified with certain confidence. Third, an integrated MADM framework is developed for multi-attribute planning under uncertainty which combines attractive features of utility function, tradeoff/risk analysis and analytical hierarchy process and thus provides a structured decision analysis platform accommodating both probabilistic evaluation approach and risk evaluation approach. Fourth, the application of screening models is investigated in the context of integrated resource planning of electric utilities as to identify cost effective demand-side options and robust generation expansion planning schemes. / Ph. D.

<p><p>In the operation, planning and design of the transmission system it is of greatest concern to quantify the reliability security margin to unwanted conditions. The deterministic N-1 criterion has traditionally provided this security margin to reduce the consequences of severe conditions such as widespread blackouts. However, a deterministic criterion does not include the likelihood of different outage events. Moreover, experience from blackouts shows, e.g. in Sweden-Denmark September 2003, that the outages were not captured by the N-1 criterion. The question addressed in this thesis is how this system security margin can be quantified with probabilistic methods. A quantitative measure provides one valuable input to the decision-making process of selecting e.g. system expansions alternatives and maintenance actions in the planning and design phases. It is also beneficial for the operators in the control room to assess the associated security margin of existing and future network conditions.</p><p>This thesis presents a method that assesses each component's risk to an insufficient transfer capability in the transmission system. This shows on each component's importance to the system security margin. It provides a systematic analysis and ranking of outage events' risk of overloading critical transfer sections (CTS) in the system. The severity of each critical event is quantified in a risk index based on the likelihood of the event and the consequence of the section's transmission capacity. This enables a comparison of the risk of a frequent outage event with small CTS consequences, with a rare event with large consequences.</p><p>The developed approach has been applied for the generally known Roy Billinton Test System (RBTS). The result shows that the ranking of the components is highly dependent on the substation modelling and the studied system load level.</p><p>With the restriction of only evaluating the risks to the transfer capability in a few CTSs, the method provides a quantitative ranking of the potential risks to the system security margin at different load levels. Consequently, the developed reliability based approach provides information which could improve the deterministic criterion for transmission system planning.</p></p>

Este trabalho analisou os leilões de comercialização de energia elétrica no ambiente de contratação regulada no Brasil, realizados entre 2005 e 2011, com o objetivo de propor aperfeiçoamentos em sua metodologia. Para tanto, foram estudadas três linhas de pesquisa: teoria de leilões, internalização (adicionais) de custos não privados (externalidades) e organização de mercados de capacidade. Após a análise dos 21 leilões de novos empreendimentos realizados no período, conclui-se que o desenho do leilão com fase discriminatória final é adequado aos objetivos de modicidade tarifária, mas que também permite melhoras. As fraquezas da sistemática atual identificadas foram: metodologia de contratação termelétrica por disponibilidade, com viés das fontes de maior custo variável unitário, adoção de preço-teto nem sempre adequado, dificuldade em mitigar o exercício de poder de mercado da Eletrobras nos leilões de energia existente e licitação pelo custo econômico privado. De forma a aprimorar os leilões, as seguintes ações foram sugeridas: realização de uma etapa adicional e prévia ao desenho de leilão híbrido atual visando contornar a problemática de estabelecimento de preço-teto adequado; utilização de adicionais ao lance do leilão para internalizar os custos de transmissão não recolhidos pelo gerador; substituição do mecanismo de contratação termelétrica pelo modelo Colombiano de opções; condução de leilões de energia nova e existente em conjunto, e segmentação de produtos no leilão pela ótica da demanda com possibilidade de lances em pacotes. Com a adoção destas propostas entende-se que o valor negociado nos leilões de comercialização de energia elétrica refletirão melhor o custo social dos projetos, aumentando a eficiência dos certames. / This study analyzes the regulated electricity procurement auctions conducted between 2005 and 2011 in Brazil, in order to propose improvements in its methodology. Thus, it was reviewed three research areas: auctions design, internalization of externalities, and capacity markets. After analyzing the 21 new energy auctions that period, it is concluded the auction design with a second discriminatory bid is appropriate to the aims at achieving as low as possible prices, however there is room for improvement. Identified weaknesses are: (1) thermal availability capacity hiring method biased in favor of energy sources with higher variable costs; (2) inadequate price cap, unable to mitigate Eletrobras market power in existing power auctions, (3) and bidding by private economic cost. So, it is suggested the following actions to improve the efficiency of energy auctions: (a) carrying out an additional step prior to the current hybrid auction design in order to solve the problem of establishing appropriate ceiling price; (b) use of additional to internalize transmission costs not paid by generator; (c) replacement of the bid mechanism used for thermal power plants to Colombian options model; (d) driving new and existing energy auctions together, and (e) segment auctions products by the demand side with the possibility of bidding in packages. In adopting these proposals it is expected the value traded in the electricity procurement auction conducted in Brazil will better reflect the social cost of projects and so improving its efficiency.

A receita operacional de uma empresa de geração predominantemente hidrelétrica é composta de duas parcelas: a comercialização de seus contratos de energia e a liquidação na Câmara de Comercialização de Energia (CCEE). A parcela de receita de contratos é previsível, mas a receita proveniente da liquidação da CCEE é de difícil mensuração porque depende das alocações do Mecanismo de Realocação de Energia (MRE) e do Preço de Liquidação das Diferenças (PLD). O trabalho apresenta os conceitos gerais dos componentes que influenciam a receita do mercado de curto prazo e um modelo para sazonalização da energia assegurada que é um dos fatores determinantes para a alocação de MRE e para a liquidação das diferenças. O modelo foi detalhado e implementado em uma ferramenta computacional utilizando Algorítmos Genéticos para a minimização da perda esperada e do risco com a sazonalização. / The operating revenue of power generation companies has two different components: revenues arising from power purchase agreements and from spot market, managed by the Câmara de Comercialização de Energia - CCEE The income of contracts is predictable, but there are a lot of difficulties to do prognosis with the spot market revenue component, because it depends on both the Energy Reallocation Mechanism (MRE) and the spot price (PLD). This text presents the influences of some components in spot market incomes and a model to alocate the assured energy along the year since this is the main factor influencing the MRE and the spot market revenues. The model was formulated and implemented in a computational tool using Genetic Algorithms (AG) to minimize the expected losses and the sazonal risk.