Artigos em Revistas

Pesquisas desenvolvidas mostram que o Brasil possui um déficit de engenheiros. Esse cenário revela um obstáculo no sistema educacional, com reflexos na produção e inovação no mercado. Este fato dá-se devido à redução da procura por esta profissão. O desinteresse, segundo especialistas, está ligado à visão que os alunos do ensino médio têm em relação às disciplinas da área de exatas. Considerando a relevância desse tema os discentes da Universidade Federal do Pará Campus - Tucuruí através do Grupo de Pesquisa de Sistemas Elétricos e Mecânicos utilizando a metodologia PBL, juntamente com a plataforma de prototipagem Arduino e seus conhecimentos em áreas multidisciplinares da Engenharia tem o objetivo de propor oficinas para alunos do ensino médio como um incentivo a engenharia através do contato com o lado pratico das ciências exatas. Por tanto o presente trabalho apresenta a metodologia utilizada nas oficinas e os resultados das etapas realizadas.

GABRIEL SOUZA DA SILVA, WELLINGTON DA SILVA FONSECA, FILIPE CAVALCANTI FERNANDES, THAYANNE BARROS BANDEIRA, ALLAN SILVA JUNIOR

This paper presents an innovative approach to calculate non-technical losses estimates in electrical distribution feeders which is based on the customers' energy consumption bills and on measurements of the injected active and reactive powers in the feeder at the substation coupling point. The proposed procedure uses the load flow Power Summation Method (PSM) which is modified to take into account the feeder power injections measurements at the substation coupling point, and adjustment factors to vary the customers' electrical loads which are obtained from the energy consumption bills, so that the active and reactive power balances at the substation are met for any operation condition. Preliminary results using this procedure are presented utilizing the IEEE 13-node test feeder.

U. H. BEZERRA, T. M. SOARES, M. V. A. NUNES, M. E. L. TOSTES, J. P. A. VIEIRA, PIEDY AGAMEZ

This study addresses the problem of determining which non-linear loads can be considered potential harmonic sources to the voltage harmonic distortions observed in the utility grid voltages. Statistical regression models are used to establish correlations between the simultaneously measured harmonic voltages, in the grid, and harmonic currents, at each non-linear individual load. First, the R-squared statistic is used to decide the goodness of fit of the developed models, giving indication on the relevance of the model. In order to overcome the limitation of the linear regression model based on voltage and current magnitudes measurements only, that imposes a constant behaviour for the background harmonic sources, a non-parametric regression model is suggested and a comparison between the performances of the two models is carried out. Field data from two real electrical systems, one having a 138 kV substation in which a large industrial load and a 34.5 kV rural long feeder are connected; and the other having four urban 13.8 kV feeders supplying industrial and commercial loads, were used to develop and validate the statistical models used in the application.

EDSON ORTIZ DE MATOS, THIAGO MOTA SOARES, UBIRATAN HOLANDA BEZERRA, MARIA EMÍLIA DE LIMA TOSTES, ALLAN RODRIGO ARRIFANO MANITO, BENJAMIM CORDEIRO COSTA JR

Em todo o país está sendo amplamente difundida a utilização de fontes de energia renováveis, um dos exemplos claros disso é a obtenção de energia através dos raios solares,como também, o recente avanço na implantação de aerogeradores na regiãoSul e Nordeste. Com oobjetivo de incentivar os alunos do ensino médio em se empenhar no estudo das ciências aplicadas e no desenvolvimento de pesquisainterligada com a eficiência energética,oPrograma de Extensão Laboratório de Engenhocas, da Universidade Federal do Pará Campus de Tucuruí, aprovou projetos no CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico)com o intuitode inserir nas escolas estaduais de ensinomédio do município a metodologia PBL(ProjectBased Learning), visando ensinar o aluno a aprender, ser proativo e despertar o interesse na área das ciênciasaplicadas. Dessa forma, os alunos buscaram desenvolver atividades que contribuíssem paraminimizar osproblemasda sociedade, com isso, construíram e implantaram um Aquecedor Solar de Baixo Custo em uma residência unifamiliar de Tucuruí onde foi possível analisar sua viabilidade e eficiência energética.

P.M.MILHOMEM, M.R.SANTOS, W.S.FONSECA, S.N.SILVA

O presente artigo tem como objetivo apresentar um relato de experiência que pretende investigar a robótica pedagógica, como ferramenta auxiliadora na disciplina de ciência, que vem sendo desenvolvida em uma escola de ensino fundamental na cidade de Santo Antônio do Tauá – Pará. Tema finalidade de investigar a contribuição da robótica pedagógica nas aulas de ciência com o uso de kit educacional Arduino. Foi desenvolvida pesquisa de caráter observacional, que constatou a robótica como um instrumento fundamental na contribuição do desenvolvimento do aluno de maneira eficiente, explorando habilidades como o raciocínio, cooperação, a inovação criativa, a ludicidade e a interdisciplinaridade, elementos substanciais na escola atual. Além disso, estabeleceu-se relação entre as atividades da robótica pedagógica com os pressupostos do lúdico na educação, visto que os robôs propostos se tornam brinquedos durante as atividades. Isto evidencia a necessidade de incentivar o estudo criativo-científico da robótica enquanto atividade pedagógica significativa nas aulas de ciências. Com isso, desenvolveu-se uma análise sobre a importância da Robótica Pedagógica enquanto recurso didático nas aulas de ciências em correlação com lúdico em sala de aula, utilizando a plataforma Arduino (experiências) e o Ardublockly (programação) como instrumentos materiais. Os pilares desta pesquisa estão fundamentados em Seymour Papert com a teoria do construcionismo, idealizador e disseminador da robótica pedagógica no ambiente escolar, buscando a construção do conhecimento de maneira interdisciplinar.

DAVID GENTIL DE OLIVEIRA, WELLINGTON DA SILVA FONSECA

In the search for strategies to mitigate climate change, the promotion of renewable energy is a major challenge worldwide, particularly for developing countries such as Brazil and Colombia, which aim to diversify their power grids by using unconventional renewable energy sources. One of the main obstacles is the development of innovative projects. Increasing oil palm cultivation in the Amazon region for the food and biodiesel industries is producing a large volume of biomass. The present study outlines a methodology for analysis of renewable energy projects based on identification of environmental, economic, and social sustainability criteria and indicators (C&I) for the oil palm production chain. This methodology was then used to develop a computer simulation model in the RETScreen® International software environment for financial viability and risk analysis.

ROSANA CAVALCANTE DE OLIVEIRA, ROGERIO DIOGNE DE SOUZA E SILVA, MARIA EMÍLIA DE LIMA TOSTES

A diesel generator was simulated operating with palm oil as fuel and hydrogen doping the inlet air. The objective was to investigate how the addition of hydrogen can accelerate the end of vegetable oil combustion, and consequently improve the electrical efficiency of the generator set up, for the same mass flow rate of fuel. The simulations were performed using AVL BOOST software and validated with experimental data. The generator was simulated operating with 75%, 80% and 100% of the nominal load using palm oil in nature, and hydrogen being injected at the intake manifold in parcels of 5% to a maximum of 20% in energy content by replacing the main fuel. The simulations showed increase in electrical power, reduction in specific fuel consumption, improving the overall efficiency of the generator set with 100% load. Good results were obtained with operation at 75% of the nominal load.

RICARDO SEAWRIGHT CAMPOS, MANOEL FERNANDES MARTINS NOGUEIRA, MARIA EMÍLIA DE LIMA TOSTES

Several authors have treated the optimization of passive filters in electric distribution systems. Optimization methods like: sequential quadratic programming (SQP), simulated annealing (SA), differential evolution (DE), artificial neural networks (ANN), particle swarm optimization (PSO), genetic algorithm (GA), etc., have been employed for optimizing certain configurations of passive filters. These optimization methods have been employed to solve several formulations of the problem of the project of filters. These formulations can be classified in: formulations of one or several objectives. The objective of the present work is to show the evolution of the formulation of this problem in the lasts years respect to the objective functions and constraints used. This analysis shows how the formulations employed have been upgraded from single-objective to multi-objective formulations to achieve a better representation of this complex problem.

JANDECY CABRAL LEITE, IGNACIO PEREZ ABRIL, MANOEL SOCORRO SANTOS AZEVEDO, MARIA EMÍLIA DE LIMA TOSTES, UBIRATAN HOLANDA BEZERRA

Different methods of optimization have been used for the selection and localization of capacitor banks in distribution circuits. However, it is necessary to consider the distortion taken place by the harmonics of the no-linear loads and the possible appearance of resonances between the inductive elements of the system and the existent capacitor banks. On the other hand, it has not been integrated in a single methodology the use of capacitor banks and of passive harmonic filters to compensate the reactive power in harmonic polluted distribution systems. The present work intends as objective to develop this methodology. The developed program is based on the multiobjective optimization algorithm NSGA-II that it is proven with success in several examples.

MANOEL SOCORRO SANTOS-AZEVEDO, IGNACIO PEREZ-ABRIL, CARLOS DE LEON-BENITEZ, JANDECY CABRAL-LEITE, UBIRATAN HOLANDA-BEZERRA

This paper proposes an analytical methodology to allocate and size active power photovoltaic generation (PVG) units with embedded DC/AC inverter (PVGI) to be integrated as concentrated or dispersed generation in isolated medium voltage electrical grids. The methodology considers multiple objectives: improving the electrical grid voltage profile; reducing active power losses and the diesel generation participation. To validate the proposed methodology, the IEEE 33 and 69 buses networks and an isolated real electrical system were simulated. The results obtained demonstrated that the proposed methodology is effective in providing a solution with improvement in voltage profile, active power losses reduction, diesel generation participation reduction.

CLÁUDIO GONÇALVES, J. PAULO A. VIEIRA, DIONE J. A. VIEIRA, M. EMILIA L. TOSTES, BERNARD C. BERNARDES, UBIRATAN H. BEZERRA