Navegando por Assunto "Electric power distribution"

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Acesso aberto (Open Access)
Modelo para tomada de decisão em programas de eficiência energética no setor de distribuição de eletricidade
(Universidade Federal do Pará, 2018-04-27) SILVA, Rogério Diogne de Souza e; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
The electricity distribution system is constantly evolving, with the dissemination of distributed energy resources, smart grids and the inclusion of competitive markets, in which the use of energy efficiency as a relevant resource for sector planning must be ensured through public policy. Brazil has for decades had a program and policy in this area, however, the results of its program for the insertion of energy efficiency actions with the financial resources of the electricity utilities, have less impact than similar programs in other countries, and there is the imminent need to meet the emission reduction targets proposed by the country at the 21st Conference of the Parties of the United Nations in December 2015 in Paris. In this context, the present thesis proposes the development of a non-parametric model for the determination of performance indicators and classification of energy efficiency projects. It also contributes to the evaluation of the Energy Efficiency Program, through a methodology to analyze the projects, classify and quantify the variables, resulting in recommendations for the improvement of the program. A database of projects submitted to ANEEL by the utilities of the electricity distribution sector from 2008 to 2016 was used. The model was developed using Data Envelopment Analysis (DEA), a non-parametric method that uses linear programming to calculate the most efficient units in a given set of decision-making units. The results show that the best performance was achieved by projects in the industrial and cogeneration categories, however, these constitute only 4.24 % of the projects presented and 5.28 % of the total investments in the last eight years, indicating the need to review energy efficiency regulatory strategies. As a solution to improve the selection of the best performing projects, it is suggested assigning weights to the categories to optimize the project results, by incentives to the projects with the best performance, without excluding the participation of all others, simply by providing energy savings goals and demand reduction at peak hours compatible with the best performing categories.
Acesso aberto (Open Access)
Otimização multiobjetivo da compensação de potência reativa em redes de distribuição considerando restrições de distorção harmônica
(Universidade Federal do Pará, 2014-11-14) AZEVEDO, Manoel Socorro Santos; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148; BEZERRA, Ubiratan Holanda; http://lattes.cnpq.br/6542769654042813
The localization of capacitors banks in the electric power distribution networks, correctly sized, looks for to compensate eventual excesses of circulation of reactive power for transmission lines, what implies the reduction of operational costs for the reduction of the energy losses and an increase of the capacity of transmission of active power assuring the established levels of voltage and power factor simultaneously. The proliferation of the nonlinear loads produced a change in the scenarios of study of the electric power systems due to the degradation effects that the harmonic generated by them cause about the quality of the electric power. Considering this new scenario, this thesis has as general objective to develop a computational tool using computational intelligence supported in genetic algorithms (GA), for the multiobjective optimization of the reactive power compensation in distribution electric networks able to locate and size in a good way the necessary compensation units to achieve the best economic benefits and the maintenance of the indexes of quality of the energy settled down by the Brazilian norms. As technological innovation of the work, the developed computational tool allows to optimize the compensation of the reactive power to improve the power factor in polluted distribution networks with harmonics that, differently of previous methods, not alone it uses capacitors banks, but also harmonic filters with that objective. The NSGA-II algorithm is used to determine optimal solutions of Pareto for the problem and it allows the specialist to determine the most effective solutions. The formulation proposed in this thesis for the solution of the problem presents several novelties being able to highlight that the achieved solution allows to determine the compensation of reactive power in systems with certain harmonic penetration, complying with pertinent standards of power quality, with respect to the tolerated levels of harmonic distortion.