Artigos em Revistas

One of the most desired aspects for power suppliers is the acquisition/sale of energy for a future demand. However, power consumption forecast is characterized not only by the variables of the power system itself, but also related to social–economic and climatic factors. Hence, it is imperative for the power suppliers to project and correlate these parameters. This paper presents a study of power load forecast for power suppliers, considering the applicability of wavelets, time series analysis methods and artificial neural networks, for both mid and long term forecasts. Both the periods of forecast are of major importance for power suppliers to define the future power consumption of a given region. The paper also studies the establishment of correlations among the variables using Bayesian networks. The results obtained are much more effective when compared to those projected by the power suppliers based on specialist information. The research discussed here is implemented on a decision support system, contributing to the decision making for acquisition/sale of energy at a future demand; also providing them with new ways for inference and analyses with the correlation model presented here.

ÁDAMO L. SANTANA, GUILHERME B. CONDE, LIVIANE P. REGO, CLÁUDIO A. ROCHA, DIEGO L. CARDOSO, JOÃO C.W. COSTA, UBIRATAN H. BEZERRA, CARLOS R.L. FRANCÊS

This study presents some data-mining experiments applied to electric power systems with the aim of extracting knowledge from historical data produced by the supervision, control and data acquisition system of a hydroelectric plant in Brazil. In the first experiment, statistical analysis is performed on discrete events such as Boolean events, alarms, commands, set-points and analogue quantities as electrical frequency, to display relevant aspects of the electrical system operation. Next, the results of an experiment performed on discrete events from associations describing relationships patterns among items in a database are presented. In the third experiment, a decision tree is used to reveal relationships among several analogue variables as: the relationship between the downstream water level and generated power, for example. In the fourth experiment, a decision tree is designed to detect if the hydro generator operation is violating any constraint imposed by its capability curve, also indicating which limit is extrapolated. These experiences contribute to successfully show the data-mining applicability to power systems, to improve the management of hydroelectric power plants operation, maintenance and planning, besides also contributing to establish a culture of its usage in the electrical industry.

I. OHANA, U.H. BEZERRA, J.P.A. VIEIRA

in this letter, a methodology is proposed for automatically (and locally) obtaining the shape factor c for the gaussian basis functions, for each support domain, in order to increase numerical precision and mainly to avoid matrix inversion impossibilities. the concept of calibration function is introduced, which is used for obtaining c. the methodology developed was applied for a 2-d numerical experiment, which results are compared to analytical solution. this comparison revels that the results associated to the developed methodology are very close to the analytical solution for the entire bandwidth of the excitation pulse. the proposed methodology is called in this work local shape factor calibration method (lsfcm).

PÉRICLES L. MACHADO, RODRIGO M.S. DE OLIVEIRA, WASHINGTON C.B. SOUZA, RAMON C.F. ARAÚJO, MARIA E.L. TOSTES, CLÁUDIO GONÇALVES

The Computer Numeric Control (CNC) is a technology which aims to generate, parse and execute sequential actions that describes the behavior of the end effector. This article reports the development small sized prototype CNC machine, based on a modular system with the capability of communication through USB. It is also reported the development of the basic electronic devices to run a CNC machine and proposes, as well, a software developed in LabVIEW to establish the communication between the machine and the computer. The main objective of this work is the development of a machine which allows future researches on the process performance, on educational purposes, the demonstration the parts involved on the CNC machine.

PAULO AUGUSTO SHERRING DA ROCHA, ROGÉRIO DIOGNE DE SILVA E SOUZA, MARIA EMÍLIA DE LIMA TOSTES

This paper focuses on supplying electrical power for remote communities of the Brazilian Amazon using regional biomass, specifically palm oil biomass, as a primary energy source. The use of Straight Vegetable Oil (SVO) as fuel, is indicated for isolated communities, where the hydro plants or the installation of transmissions line are impracticable. The use of vegetable oils produced in the communities, is a solution when an adequate infrastructure to extracting the oil is available. Brazil is able to use an enormous diversity of vegetable oils, due to a great variety of plants, and the favorable climatic conditions. Technical, economic, environmental and social aspects are analyzed in order to provide a basis for electrical power supply viability in these communities. A case study is presented focused on a typical Brazilian Amazon community located in the State of Pará in order to demonstrate the applicability of the proposed viability strategy.

ANA ROSA DUARTE, UBIRATAN HOLANDA BEZERRA, MARIA EMÍLIA DE LIMA TOSTES, ANDRÉ MONTENEGRO DUARTE, GERALDO NARCISO DA ROCHA FILHO

Um dos fatores que impulsionaram o desenvolvimento de diversas tecnologias é a busca constante da humanidade pelo conforto e comodidade. Isso está diretamente relacionado ao desenvolvimento da automação residencial. No entanto, devido à complexidade e custos elevados estes sistemas são privilégios apenas de alguns indivíduos. Em vista disso, este trabalho apresenta uma análise comparativa entre três projetos para a automação do sistema de iluminação de uma residência. Dois dos sistemas de automação foram desenvolvidos pelos próprios autores para uma implantação de baixo custo utilizando microcontroladores (Arduino e ESP32) através de diferentes canais de comunicação sem fio (Wi-Fi e Bluetooth), o terceiro sistema é um dispositivo que já existe no mercado. Esses sistemas de automação foram implementados em um modelo de residência popular e comparados entre si em termos de consumo de energia, custo de implementação e eficiência de projeto. Os três sistemas foram analisados com dois tipos diferentes de lâmpadas para resultados mais consistentes. Onde um dos objetivos deste trabalho é mostras que é possível incorporar parâmetros de automação residencial de baixo custo em casas populares.

ANTONIO RONIEL MARQUES DE SOUSA, PAULO RODRIGUES DOS SANTOS, WELLINGTON DA SILVA FONSECA, ALLAN RODRIGO ARRIFANO MANITO, RAMON CRISTIAN FERNANDES ARAÚJO