Expansão da capacidade do atendimento de ponta no Sistema Interligado Brasileiro

Within the current regulatory model of the Brazilian electricity sector, the lack of specific regulation for the market power reserve services in the long term leads to the underestimation of generation assets, especially in cases where additional investment would enable increasing the installed capacity of existing hydroelectric plants at low cost. A correct evaluation of such investment would have important consequences in the medium term, it would reduce the social energy shortage costs, both preventive, reflected by thermal dispatch, as well corrective, incurred in the recovery of production losses and others due to long-duration interruptions of energy supply.No atual modelo regulatório do setor elétrico brasileiro, a ausência de regulação específica para comercializar serviços de reserva de potência, em horizonte de longo prazo, acarreta a subvalorização dos ativos de geração, notadamente nos casos em que investimentos adicionais permitiriam ampliar a capacidade instalada de usinas hidrelétricas existentes, a baixo custo. A correta valoração desse tipo de investimento teria consequências importantes em médio prazo, pois permitiria reduzir os custos sociais de interrupção, tanto os preventivos, refletidos por despacho térmico, quanto os corretivos, incorridos na recuperação de perdas de produção e outras devidas a interrupções de longa duração

Equipment rating maximization and standardization of substations and transmission lines: a support for the planning of electrical networks in the context of financial constraints.

Este trabalho tem por meta focalizar a adaptação necessária na metodologia de planejamento atual, norteada segundo uma ótica determinística e conservadora, afim de permitir a elaboração de Programas de Obras de Transmissão/Subtransmissão, condicionados por limitações de teto no montante de investimento a curto e médio prazos. Para tanto, como tema central, busca-se desenvolver uma base conceitual e metodológica, para permitir uma exploração maximizada das possibilidades de carregamento de equipamentos e instalações do sistema de transmissão, contemplando a especificação das ferramentas computacionais necessárias para dar consequência prática à proposta. Considerando o potencial de análise proporcionado por métodos e técnicas de natureza probabilística, aplicados ao planejamento de Sistemas Elétricos, a espinha dorsal da evolução metodológica delineada no texto repousa sobre a avaliação de confiabilidade global e quantificação de riscos operativos. O texto foi estruturado em 8 capítulos onde, a partir de um capítulo introdutório, enfoca-se sequencialmente os temas: * Conceitos e Metodologias para Maximização do Carregamento de Transformadores de Potência. * Conceitos e Metodologias para Maximização do Carregamento de Linhas aéreas de Transmissão. * Impacto das Restrições Financeiras no planejamento e possibilidade de atuação a nível técnico para administrar o conflito entre qualidade de serviço e recursos limitados. * Conceitos e Metodologias para relaxação dos Critérios limitantes para o carregamento máximo de componentes do sistema, em ambiente de severas restrições financeiras, no horizonte de curto prazo. * Resultados obtidos em aplicações concretas a situações do Setor Elétrico, visando caracterizar o alcance do ferramental preconizado nos capítulos anteriores. * Critérios e Procedimentos para Padronização de Subestações e Linhas de Transmissão , coerentes com os conceitos de maximização de carregamento introduzidos nos dois primeiros capítulos. Ao final do texto, incluiu-se um capítulo de \"Conclusões\", com o objetivo de sumarizar os aspectos mais relevantes abordados no texto, assim como indicar linhas de ação e novos desenvolvimentos, necessários para permitir a efetivação prática da metodologia proposta.An important problem posed to power system planners in developing countries is now becoming commonplace, even in developed countries, and concerns on how to fit an expansion plan into a tight budget, with the least reduction in reliability levels. This problem is known as power system planning under financial constraints and a series of methods is now available to deal with it. So, this work addresses the necessary adjustments in order to permit the Transmission / Sub-transmission Expansion Program establishment when there are investments constraints in a medium/short term range. The main emphasis is on the development of a methodological and conceptual framework, aiming at a maximizes exploration of the loading capability of transformers and transmission lines of the power network. In this context, a new methodological framework for transmission system planning in a financial constrained environment is presented. The proposed approach combines transmission projects priority evaluation and ranking as well as criteria flexibilization, being particularly suitable for short-term planning. The problem to be faced is to operate the system after a project postponement, while the service quality is kept so adequate as it is possible. One of the main issues to be focused is the transmission system uprating since a maximized equipment utilization can contribute to avoid a more significant restriction to the costumers. Therefore, a detailed description of the models for transmission lines and transformers loading limits assessment is presented, with emphasis on the main concepts and the application of probabilistic tools to circumvent the inherent conservatism of deterministic methods. A summary of the contents is presented in what follows: * Concepts and Methodology for Transformers loading maximization. * Concepts and Methodology for Transmission Lines loading maximization. * Financial Restrictions impacts on Expansion Planning Process and the possibilities to manager the conflict between service quality and investment constraints. * Concepts and Methodologies to the relaxation of Criteria that limits the loading capability of transmission lines, aiming at short term Planning under severe financial restrictions, * Obtained results in concrete applications of the proposed methodology and computational tools to Brazilian Electric Power System. * Methods and Criteria to standardization of Substations and Transmission Lines, according the main issues formerly introduced. * Conclusion and Future Research

Equipment rating maximization and standardization of substations and transmission lines: a support for the planning of electrical networks in the context of financial constraints.

Este trabalho tem por meta focalizar a adaptação necessária na metodologia de planejamento atual, norteada segundo uma ótica determinística e conservadora, afim de permitir a elaboração de Programas de Obras de Transmissão/Subtransmissão, condicionados por limitações de teto no montante de investimento a curto e médio prazos. Para tanto, como tema central, busca-se desenvolver uma base conceitual e metodológica, para permitir uma exploração maximizada das possibilidades de carregamento de equipamentos e instalações do sistema de transmissão, contemplando a especificação das ferramentas computacionais necessárias para dar consequência prática à proposta. Considerando o potencial de análise proporcionado por métodos e técnicas de natureza probabilística, aplicados ao planejamento de Sistemas Elétricos, a espinha dorsal da evolução metodológica delineada no texto repousa sobre a avaliação de confiabilidade global e quantificação de riscos operativos. O texto foi estruturado em 8 capítulos onde, a partir de um capítulo introdutório, enfoca-se sequencialmente os temas: * Conceitos e Metodologias para Maximização do Carregamento de Transformadores de Potência. * Conceitos e Metodologias para Maximização do Carregamento de Linhas aéreas de Transmissão. * Impacto das Restrições Financeiras no planejamento e possibilidade de atuação a nível técnico para administrar o conflito entre qualidade de serviço e recursos limitados. * Conceitos e Metodologias para relaxação dos Critérios limitantes para o carregamento máximo de componentes do sistema, em ambiente de severas restrições financeiras, no horizonte de curto prazo. * Resultados obtidos em aplicações concretas a situações do Setor Elétrico, visando caracterizar o alcance do ferramental preconizado nos capítulos anteriores. * Critérios e Procedimentos para Padronização de Subestações e Linhas de Transmissão , coerentes com os conceitos de maximização de carregamento introduzidos nos dois primeiros capítulos. Ao final do texto, incluiu-se um capítulo de \"Conclusões\", com o objetivo de sumarizar os aspectos mais relevantes abordados no texto, assim como indicar linhas de ação e novos desenvolvimentos, necessários para permitir a efetivação prática da metodologia proposta.An important problem posed to power system planners in developing countries is now becoming commonplace, even in developed countries, and concerns on how to fit an expansion plan into a tight budget, with the least reduction in reliability levels. This problem is known as power system planning under financial constraints and a series of methods is now available to deal with it. So, this work addresses the necessary adjustments in order to permit the Transmission / Sub-transmission Expansion Program establishment when there are investments constraints in a medium/short term range. The main emphasis is on the development of a methodological and conceptual framework, aiming at a maximizes exploration of the loading capability of transformers and transmission lines of the power network. In this context, a new methodological framework for transmission system planning in a financial constrained environment is presented. The proposed approach combines transmission projects priority evaluation and ranking as well as criteria flexibilization, being particularly suitable for short-term planning. The problem to be faced is to operate the system after a project postponement, while the service quality is kept so adequate as it is possible. One of the main issues to be focused is the transmission system uprating since a maximized equipment utilization can contribute to avoid a more significant restriction to the costumers. Therefore, a detailed description of the models for transmission lines and transformers loading limits assessment is presented, with emphasis on the main concepts and the application of probabilistic tools to circumvent the inherent conservatism of deterministic methods. A summary of the contents is presented in what follows: * Concepts and Methodology for Transformers loading maximization. * Concepts and Methodology for Transmission Lines loading maximization. * Financial Restrictions impacts on Expansion Planning Process and the possibilities to manager the conflict between service quality and investment constraints. * Concepts and Methodologies to the relaxation of Criteria that limits the loading capability of transmission lines, aiming at short term Planning under severe financial restrictions, * Obtained results in concrete applications of the proposed methodology and computational tools to Brazilian Electric Power System. * Methods and Criteria to standardization of Substations and Transmission Lines, according the main issues formerly introduced. * Conclusion and Future Research

Electric Power Forecasting Methodologies of Some South American Countries: A Comparative Analysis

In this paper, a comparative analysis of the long-term electric power forecasting methodologies used in some South American countries, is presented. The purpose of this study is to compare and observe if such methodologies have some similarities, and also examine the behavior of the results when they are applied to the Brazilian electric market. The abovementioned power forecasts were performed regarding the main four consumption classes (residential, industrial, commercial and rural) which are responsible for approximately 90% of the national consumption. The tool used in this analysis was the SAS (c) program. The outcome of this study allowed identifying various methodological similarities, mainly those related to the econometric variables used by these methods. This fact strongly conditioned the comparative results obtained

Applying Copulas Functions for Wind and Hydro Complementarity Evaluation: a Brazilian Case

Wind energy has been expanding in many countries typically hydro electricity producers in the last decades and some investments take advantage from the complementarity among hydro and wind productions as a strategy to increase profits and minimize risks. In this paper, our focus is applying copulas functions to evaluate a complementarity between wind and hydro production in different regions in Brazil. The goal is evaluate which regions are most suitable for development of wind energy considering the existing hydro electricity production. Copulas functions can capture the dependence structure among random variables offering a great flexibility in building multivariate stochastic models while statistic correlation does not capture nonlinear effects sufficiently. For this reason, we apply nine different copulas functions in our study finding those that best capture the complementarity

Barriers to the Expansion of Sugarcane Bioelectricity in Brazilian Energy Transition

This article evaluated bioelectricity’s evolving competitiveness and systemic complementarity benefits, both in comparison with other renewable sources. To do so, the results of several energy auctions were analysed, and a modelling exercise was developed using an optimisation model based on stochastic dual dynamic programming. The results indicate that wind and solar energies became the least cost expansions, and sugarcane bioelectricity lost significance and competitiveness in this environment. At the same time, the study shows that wind power’s potential to be complementary to hydropower generation is greater than bioenergy in Brazil. These findings have relevant policy implications regarding the power sector and whether bioelectricity from sugarcane should still be incentivised along with wind power sources. It is worthwhile to point out that although the Brazilian case is explored in the article, it can be used as an example by other countries, especially developing ones, that can take advantage of Brazilian expertise on biomass exploitation aiming at integration with the power sector

Analysis of the Implementation of Virtual Power Plants and Their Impacts on Electrical Systems

The increasing penetration of Distributed Energy Resources (DERs) in Distribution Systems (DSs) has motivated studies on Virtual Power Plants (VPPs). However, few studies have jointly assessed the sizing and economic attractiveness of VPPs from the entrepreneur’s perspective and the potential benefits and impacts on power systems while maintaining the scope to DSs. This study proposes a methodology for sizing VPPs and simulating their economic optimal dispatch and economic attractiveness with a focus on the entrepreneur’s viewpoint. In addition, it also evaluates VPPs’ potential benefits and impacts on a DS or Transmission System (TS) while considering the interface between the Distribution System Operator (DSO) and the Transmission System Operator (TSO). The methodology employs optimization to minimize the Net Present Cost (NPC) of the project, in relation to sizing the DERs, and to obtain the economic optimal dispatch of the BESSs that comprise the VPP. Moreover, a power flow analysis and probabilistic reliability assessment are used to evaluate the benefits and impacts on the power system. The methodology was applied to a case study involving Photovoltaic (PV) systems and Battery Energy Storage Systems (BESSs) used by aggregated medium voltage consumers, which configure Technical Virtual Power Plants (TVPPs) participating in Demand Response (DR) via incentives, with a network model of the Brazilian National Interconnected System (SIN) adapted from the 2030 Ten-Year Energy Expansion Plan (PDE) of the Energy Research Office (EPE), along with data from the Geographic Database of the Distribution Utility (BDGD). The results indicate the economic attractiveness of DERs according to the premises adopted and indicate improvements in TS reliability indexes with the possibility of TVPPs’ dispatch after transmission contingencies

Hydro–Solar Hybrid Plant Operation in a Hydropower Plant Cascade: Optimizing Local and Bulk System Benefits

A hydro–solar hybrid system is an important solution for expanding renewable generation capacity under the percepts of the energy transition. This type of association allows for the coordinated dispatch of solar and hydropower plants, resulting in operational benefits in terms of energy generation and reservoir management, that is, the better use of available water and energy resources. As in this case, the operation of the hydropower plant is associated with the cascade in which it operates, when it is hybridized (for example, by associating with a solar power plant), in addition to local changes, there are impacts on the operating conditions of the other hydropower plants in the same cascade. From such a perspective, this study presents an energy system management model for hybrid power plants composed of hydro and solar sources, aiming to optimize the joint operation and measure the operational consequences at the local level and in the cascade. The results from a case study of a hydro–solar power plant hybridization in the Tietê River (Brazil) revealed increased energy production and improvement in the operating conditions of the cascade’s reservoirs, while the grid capacity was found to be an important constraint that limits the capture of synergies resulting from the generation sources complementarity and thus on the benefits to the cascade