Navegando por Autor "COSTA JUNIOR, Carlos Tavares da"

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Aplicação de Filtro Harmônico em Sistemas Elétricos de Baixa Tensão Utilizando Lógica Fuzzy
(Universidade Federal do Pará, 2010) CIRINO, Weverson dos Santos; COSTA JUNIOR, Carlos Tavares da
This work presents a solution to minimize harmonic distortion in low-voltage electrical systems through the application of passive harmonic filters and the use of fuzzy logic. The proposed algorithm detects and calculates the frequencies at which the Total Harmonic Distortion (THD) value is elevated, comparing it with a normative index. Once the need for filter application is identified, the algorithm designs the passive filter, chosen for its ease of installation and low cost. The algorithm also recalculates the THD after filter application, using fuzzy logic to classify the final result.
Desenvolvimento de um Sistema Inteligente para Determinação de Set Point no Controle da Área Superficial da Alumina: Aplicação de Lógica Fuzzy em Calcinadores de Leito Fluidizado
(Instituto de Tecnologia, 2015) COSTA, Hugo Pedro de Sousa Valente da; COSTA JUNIOR, Carlos Tavares da
This study investigates the implementation of a fuzzy system to control the specific surface area of alumina in fluidized bed calciners. The fuzzy methodology was chosen for its ability to handle complex and imprecise problems, leveraging empirical knowledge from experts. The developed system proposes temperature and pressure set points to optimize alumina quality and operational safety. Simulation results demonstrated the system's effectiveness, with adjustments based on real data collected from January to December 2014.
Identificação das Componentes Harmônicas em uma Instalação Elétrica através do Fator de Potência Utilizando Inferência Fuzzy
(INSTITUTO DE TECNOLOGIA, 2010) NEVES, Cleonor C. das; COSTA JUNIOR, Carlos Tavares da; Profa. Dra. Maria Adrina Paixão de Souza da Silva.
This paper proposes a method to identify harmonic components in industrial electrical installations using fuzzy inference and power factor as the main parameter. The linguistic fuzzy logic model was applied to analyze disturbances in the electrical system, based on data collected from a factory in the Manaus Industrial Hub. The study presents an alternative for detecting noise (harmonics) and contributes to improving power quality in electrical systems, using international standards as a reference.
Implantação do Sistema de Rejeição de Cargas (SRC) no Sistema Elétrico de Potência (SEP) da Hydro Alunorte
(Instituto de Tecnologia, 2015) CORRÊA, José Luiz; COSTA JUNIOR, Carlos Tavares da
The study presents the implementation of a Load Rejection System (LRS) at Hydro Alunorte to preserve internal power generation and partial production during external power failures. The LRS, using frequency relays, automatically sheds non-priority loads, ensuring the continuity of utilities (water, steam, and compressed air) and minimizing financial losses. The system was successfully tested in real events, demonstrating its effectiveness.
Melhoria na Arquitetura do Sistema de Controle de Combustão de uma Caldeira Modelo DZ-SD na Refinaria da Hydro Alunorte
(Instituto de Tecnologia, 2015) SOUSA JUNIOR, Juvenal Farias de; COSTA JUNIOR, Carlos Tavares da
This work presents a proposal to modify the furnace pressure control system in the DZ boiler at Hydro Alunorte refinery, aiming to solve instability problems during load variations. The implementation of the feedforward control strategy resulted in greater operational stability, increased boiler response speed, and the restoration of automatic operation of the combustion system and oxygen control. The results showed significant improvements in boiler performance and the reliability of the steam generation system.
Metodologia de Avaliação da Qualidade do Ruído nos Postos de Trabalhos Industriais Baseada em Lógica Fuzzy
(Programa de Pós-Graduação em Engenharia Elétrica, 2010) NOGUEIRA, Maria Amélia Costa Saraiva; COSTA JUNIOR, Carlos Tavares da
The noise is ranked third among the most unhealthy agents affecting human health. Occupational noise that affects employees in their day-to-day tasks can be prevented through the involvement of employers and employees in a hearing conservation program. This study proposes the applicability of fuzzy logic to evaluate the quality of noise in industrial jobs, considering variables such as noise level and number of hours worked. Thus, using fuzzy logic modeling, measured noise levels were assessed, generating results that classify the work environment as satisfactory or high-risk, as well as providing guidance on whether or not to use safety equipment in hazardous environments. Prevention seeks to minimize or even eliminate hearing and non-hearing health problems, which are very common nowadays.
OS IMPACTOS NA QUALIDADE DA ENERGIA ELÉTRICA ORIUNDOS DAS LÂMPADAS FLUORESCENTES COMPACTAS INSTALADAS NO PROGRAMA LUZ PARA TODOS
(Universidade Federal do Pará, 2012) NEVES, Cleonor Crescêncio das; COSTA JUNIOR, Carlos Tavares da
The Brazilian Federal Program "Luz para Todos" provides installation kits that include three 15W compact fluorescent lamps in beneficiary households. These lamps exhibit a high level of harmonic distortion due to their auxiliary equipment. This study assesses the impact of these lamps on power quality by analyzing the injection of harmonics into distribution networks. Measurements of Total Harmonic Distortion (THD) were conducted, extending the analysis to a real distribution system operated by the CELPA utility company. The results indicate high levels of THD, significantly affecting the quality of power supplied to consumers.
Os Impactos na Qualidade da Energia Elétrica Oriundos das Lâmpadas Fluorescentes Compactas Instaladas no Programa Luz para Todos
(Universidade Federal do Pará, 2012) NEVES, Cleonor Crescêncio das; COSTA JUNIOR, Carlos Tavares da
The Brazilian Federal Program "Luz para Todos" provides for the installation of 15W compact fluorescent lamps (CFLs) in rural households and underserved communities. This work evaluates the impact on power quality caused by the injection of harmonics generated by these lamps. Measurements of Total Harmonic Distortion (THD) were performed using an AC power source and a power quality analyzer. The results show that CFLs introduce significant distortions in the current, with THD up to 121.2%, which can compromise the quality of power supplied by distribution systems. The study also simulates the impact on a real distribution system of the utility CELPA, highlighting the need to review planning and sizing methodologies for electrical systems to address these disturbances.
Proposta de um algoritmo para diagnosticar a qualidade de energia elétrica utilizando lógica fuzzy
(INSTITUTO DE TECNOLOGIA, 2010) GONÇALVES, Benevaldo Pereira; LEITE, Jandecy Cabral; COSTA JUNIOR, Carlos Tavares da; TOSTES, Maria Emilia de Lima; Eduardo de Magalhães Braga
The article proposes a fuzzy logic-based algorithm to diagnose power quality in low-voltage three-phase systems using the THD (Total Harmonic Distortion) indicator. The fuzzy inference system classifies distortion levels in voltage and current, generating diagnoses such as "normal," "significant," or "critical." The method aims to assist in problem identification and decision-making to mitigate harmonic disturbances, contributing to improved power quality.
Redução do consumo de energia elétrica em Manaus através de medidas de eficiência energética em climatização industrial
(INSTITUTO DE TECNOLOGIA, 2010) SILVA, Jorge Lúcio da; LEITE, Jandecy Cabral; COSTA JUNIOR, Carlos Tavares da; Jandecy Cabral Leite
The article evaluates the impacts of reducing electricity consumption in a company at the Manaus Industrial Hub (PIM) through the optimization of energy efficiency (EE) in industrial air conditioning systems, using Fuzzy Logic as a basis. Measures such as replacing low-efficiency air conditioners with high-efficiency equipment, controlling external heat sources, checking pipeline losses, and adjusting thermal comfort temperature were implemented. The results showed significant reductions in energy consumption and contracted demand, demonstrating the economic and technical feasibility of the adopted measures.
Sistema Fuzzy para Avaliação de Desempenho de Programas de Governo
(Instituto de Tecnologia, 2018) PEREIRA, Olavo Gomes; COSTA JUNIOR, Carlos Tavares da
This work implemented a Fuzzy System of Evaluation of Government Programs, evaluation of the mid-term type, presenting improvements in relation to the current system, called Preventive Control System - Monitoring and Evaluation of Programs (SICONP-MAP), in the treatment of points of singularity and cloudiness, with potential possibility of incompleteness treatment. The modeling was implemented in the JuzzyOnline and RProject platforms, where both evaluated the "Security for Peace" Program and presented 99.99% similarity, 0.101914 for the maximum difference of the residual values, 0.003688 for the median, and 0.035 for the standard deviation. These metrics showed that there were no differences between the implementations with a level of significance lower than 0.1%, where it is inferred that the modeling is robust. Robustness was compared with SICONP-MAP, where the Fuzzy System presented an accuracy of 88.88%, corresponding to 24 of 27 actions evaluated according to reality, against 44.44% of SICONP's accuracy associated with 12 actions with assessments adhering to reality. Considering that the Fuzzy System points out the distribution of stratified actions in the field of evaluation, i.e., the performance characteristic of the Program based on actions, it was observed the distribution of the expenditure realized in the field of evaluation, and then it was verified to what extent the first distribution explains the distribution of the expense. The sequences presented 94.82% similarity, 0.029291 for the maximum difference of the residual values, 0.008312 for the median, and 0.007549 of standard deviation, confirming a significance lower than 0.1%. Despite the high correlation, the metric of the expense, which points to the quality of the expenditure, evidenced the risk of classifying 43.64% of the expenditure as high performance whose actions were included as suspected of "Planning Failure". The implementation can be extended to all spheres of government, applying directly to any Program that does not present incompleteness, otherwise, it is necessary to pre-treat the data.
Sistema para Tomada de Decisão na Programação de Produção de Celular e Modem Utilizando Lógica Fuzzy
(Universidade Federal do Pará, 2010) SILVA, Carlos Américo de Souza; COSTA JUNIOR, Carlos Tavares da
The objective of this paper is to present a model using fuzzy logic, which seeks to assist the process of making decisions as to which product should have priority in scheduling the manufacturing process where there are two classes of products (WCDMA Modem and Mobile Phone). With this, it aims to identify particularities and characteristics of the productive processes, creating a better sequencing of production, whose master plan of production will be able to meet demand according to market fluctuations. The main purpose of the proposed system is to assist professionals in industrial planning to determine which products should be prioritized in the production line based on manufacturing characteristics, such as delivery time, cycle time, production process, and margin contribution, creating a production program best suited to the reality of the organization, in other words, optimizing existing resources and increasing profits.
Sistema para Tomada de Decisão na Programação de Produção de Celular e Modem, Utilizando Lógica Fuzzy
(Universidade Federal do Pará, 2010) SILVA, Carlos Américo de Souza; COSTA JUNIOR, Carlos Tavares da
The objective of this paper is to present a model using fuzzy logic, which seeks to assist the process of making decision as to which product should have priority in scheduling of the manufacturing process where there are two classes of products (WCDMA Modem and Mobile Phone). With this, it aims to identify particularities and characteristics of the productive processes, creating a better sequencing of production, whose master plan of production will be able to meet demand according to market fluctuations. The main purpose of the proposed system is to assist professionals in industrial planning to determine which products should be prioritized in the production line based on manufacturing characteristics, such as delivery time, cycle time, production process, and margin contribution, creating a production program best suited to the reality of the organization, in other words, optimizing existing resources and increasing profits.