Navegando por Assunto "Harmonics"

Agora exibindo 1 - 7 de 7

Acesso aberto (Open Access)
Análise dos impactos harmônicos na qualidade da energia elétrica utilizando kdd – estudo de caso na Universidade Federal do Pará
(Universidade Federal do Pará, 2019-03-18) SILVA, Waterloo Ferreira da; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
The present work presents an analysis of data related to Power Quality (PQ), the increasing use of nonlinear loads, equipment based on power electronics in residential, commercial and industrial installations are contributing to the significant increase in the levels of harmonic distortion of current and, consequently, of voltage, as observed in the Brazilian electricity distribution system. It was developed in Brazil, the distribution procedures in the national electricity system (PRODIST), created and developed by the National Electric Energy Agency (ANEEL). PRODIST aims to standardize and standardize activities related to energy distribution, including product quality standards. In order to monitor the quality of the product "electric energy" through the harmonic content generated by the electric network of the institution, a methodology is proposed for the analysis using computational intelligence (CI) and data mining techniques to analyze the data collected by meters of energy quality installed in the main sectors of this institution and at the point of common coupling of the consumer and consequently establish the relationship between the harmonic currents of the nonlinear loads with the harmonic distortion at the common coupling point. The KDD process was applied, including the collection, selection, cleaning, integration, transformation and reduction, mining, interpretation and evaluation of the data, in order to monitor the quality of the product "electric energy" through the harmonic content generated by the electric grid. educational institution. In the "Data Mining" data mining phase, the Naive Bayes classifier was used. The obtained results showed that the KDD process has applicability in the analysis of the Total Harmonic Distortion of Voltage at the Common Coupling Point and can be applied in any commercial, residential and industrial area.
Acesso aberto (Open Access)
Aplicação de filtro harmônico em sistemas elétricos de baixa tensão utilizando Lógica Fuzzy
(Universidade Federal do Pará, 2010-09-02) CIRINO, Weverson dos Santos; COSTA JÚNIOR, Carlos Tavares da; http://lattes.cnpq.br/6328549183075122
In an electric system several circuits and industrial equipments that behave as no-lineal devices exist. That behavior generates distortions in the electric system. Those distortions are called of Harmonic. This article introduces one of the several solutions to minimize that problem through the use of passive harmonic filters. The application of that filter will feel through a tool of computer generated to analyze and to detect which harmonic are present in the entrance sign and they harm the quality of the supply service, as well as, in projecting the passive filter. The Algorithm is divided in two phases, one for analysis and detection and the other based on Fuzzy Logic for the definition of the state of the supply service - QEE (Quality of the Electric power).
Acesso aberto (Open Access)
Avaliação de algoritmos evolucionários multiobjetivo para o problema de alocação de bancos de capacitores na presença de harmônicos
(Universidade Federal do Pará, 2017-08-10) KATAOKA, Vitor da Silva; BEZERRA, Ubiratan Holanda; http://lattes.cnpq.br/6542769654042813; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
The rapid growth of urban areas bring, as a consequence, an increase in the amount of loads connected to the distribution grids. Furthermore, the increase in the demand implies in equal raise in reactive loads, which are known to cause losses in the network. Thus, the utilities have a great challenge ahead, as the dynamics of the load require a greater effort in terms of expansion and improvements of the grid. In an attempt to mitigate the problems caused, the allocation of capacitor banks can become a practical, economical and technically robust solution. Nevertheless, it is extremely important to analyze the sizing and positioning of the banks, in order to achieve the best possible outcome. In parallel, the increasing use of nonlinear loads cause harmonics to appear in the system. When in conjunction with capacitor banks, it is possible to develop the far more dangerous phenomenon of resonance, where the amplitude of some of the harmonics goes beyond acceptable limits, resulting in undesirable effects. In this context, this work proposes a comparison between two multiobjective optimization tehcniques, NSGA-II and SPEA2, to solve the problem of sizing and placement of capacitor banks in electric energy distribution grids, considering the effects of harmonics produced by nonlinear loads.
Acesso aberto (Open Access)
Experimental evaluation, diagnosis, and prediction of the impacts of power quality disturbances in IE2, IE3, and IE4 class efficiency motors
(Universidade Federal do Pará, 2024-03-20) MUÑOZ TABORA, Jonathan; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
Acesso aberto (Open Access)
Localização de falhas em linhas de transmissão utilizando decomposição harmônica e redes neurais artificiais
(Universidade Federal do Pará, 2006-07-05) GOMES, Cristiane Ruiz; VIEIRA JÚNIOR, Petrônio; http://lattes.cnpq.br/1958791286192330
This work proposes a new methodology for fails location in transmission lines. This methodology consists in using harmonic decomposition of the leakage current and in the application of an Artificial Neural Network (ANN), this is able to recognize patterns of normal and fails conditions of a transmission line. It was developed a Pi model capable to use real data of voltage and current of the three phases. In this model values of capacitance, inductance and resistance can be modified in agreement of weather conditions. Fails were generated in all the towers with different values of capacitance. The input/output data were used to train the neural network. The real voltage and current data acquisition were done by instruments installed in the two terminals of the Guamá-Utinga transmission line belonging to Centrais Elétricas do Norte - ELETRONORTE. The computation of the parameters was made by the well known matricial method and was improved by Finite Element Method. An ANN was developed with Matlab software. For training the ANN it was used the backpropagation resilient algorithm, which presented good performance, been fast and accurate. The ANN was trained by two different sets to analyze differences between outputs. In the two cases results were satisfactory.
Acesso aberto (Open Access)
Metodologia para diagnosticar a qualidade de energia elétrica referente à distorção harmônica em sistema trifásico de baixa tensão utilizando lógica fuzzy
(Universidade Federal do Pará, 2010-09-02) GONÇALVES, Benevaldo Pereira; COSTA JÚNIOR, Carlos Tavares da; http://lattes.cnpq.br/6328549183075122
This work emphasizes the importance of monitoring and diagnosing the quality of electric power from the viewpoint of harmonic distortion present in the electrical installation in low voltage three-phase system using a methodology to analyze and diagnose the level of harmonic disturbances evaluating the overall indicator of distortion Harmonic (THD), supported by an expert system based on a Fuzzy inference system.
Acesso aberto (Open Access)
Sistema inteligente de suporte a análise da qualidade da energia elétrica em regime permanente
(Universidade Federal do Pará, 2017-02-21) ROCHA, Gabriel Vianna Soares; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
This work presents the development of software that provides a computational environment so that the user can carry out analyzes of Quality of Eletrical Energy (QEE) following the rules stipulated by the National Eletrical Power Agency (ANEEL) through the Distribution Procedures (PRODIST). Also it is possible to do analysis of contribution of impacts caused by the injection of harmonics in the electric network, pointing out the possible percentage shares of contribution of each Consumer Unit (UC), through modules that perform a sensitivity study through Computational Intelligence (CI) techniques as Artificial Neural Network (ANN) Regression Trees (RT) and Simple Linear Regression (LR). For the construction of the models are used time series data of current and voltage harmonics that were obtained through measurement campaigns.