Programa de Pós-Graduação em Engenharia Elétrica - PPGEE/ITEC
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2314
O Programa de Pós-Graduação em Engenharia Elétrica (PPGEE) do Instituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA) foi o primeiro e é considerado o melhor programa de pós-graduação em Engenharia Elétrica da Região Amazônica. As atividades acadêmicas regulares dos cursos de mestrado e doutorado são desenvolvidas principalmente nas Faculdades de Engenharia Elétrica e Engenharia de Computação, supervisionadas pela Coordenação do Programa de Pós-Graduação em Engenharia Elétrica (CPPGEE).
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Navegando Programa de Pós-Graduação em Engenharia Elétrica - PPGEE/ITEC por Orientadores "BARREIROS, José Augusto Lima"
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Item Acesso aberto (Open Access) Acionamento vetorial por controlador fuzzy modo deslizante de motor de indução(Universidade Federal do Pará, 2010-05-20) TEIXEIRA, Raphael Barros; BARRA JUNIOR, Walter; http://lattes.cnpq.br/0492699174212608; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453This work studies the technique of vector drive applied to three-phase induction motor (IM), using as the control strategy fuzzy control and sliding mode control in a setting here called Fuzzy Sliding Mode Controller (FSMC) . A dynamic model is developed at IM in variable ’d - q’ which led to an electromechanical model state space that exhibits strong nonlinearities . In this model the conditions that allow vector control decouple the torque and flux at IM, so that their dynamic behavior is similar to that observed in a DC machine are applied. In this condition, the proportional and integral type (PI) controllers are implemented to control motor speed and current loops, and computational simulations for tracking speed and load disturbance are carried out, which lead to satisfactory results from the point of view dynamic. In order to investigate the performance of nonlinear strategies in this approach the study of control technique the switching structure of the sliding mode type is displayed. A conventional sliding mode controller is implemented, where it appears that, despite the excellent dynamic performance of the occurrence of the phenomenon of ”chettering”precludes the application of this strategy in actual tests. Thus, FSMC control strategy is proposed, trying to associate the good result obtained with the dynamic sliding mode controller and the suppression of the chettering, which is achieved by defining a layer switching fuzzy type. The FSMC proposed controller is subjected to the same computational tests that the PI controller, leading to superior results to the latter the transient dynamic response, but with the presence of steady-state error. To attack this problem is implemented one of the strategies Fuzzy FSMC combination with the action of PI control, where the first seeks to operate in remote regions of the switching surface and the second seeks to introduce the effect of integral action near the surface. The results show the feasibility of the strategy in variable speed drive that demand high dynamic performance.Item Acesso aberto (Open Access) Influências de famílias wavelets e suas ordens no desempenho de um localizador de faltas em linhas aéreas de transmissão de energia elétrica(Universidade Federal do Pará, 2011-11-04) ARAUJO, Maryson da Silva; BARRA JUNIOR, Walter; http://lattes.cnpq.br/0492699174212608; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453This dissertation objective to analyze the influence of wavelets families and their orders in the performance of a fault location algorithm through the traveling waves from two ends of an overhead transmission line. Then, a secondary objective is the modelling of an electric power system (EPS) to obtaining of a fault’s universe to validate the algorithm. For that, part of an EPS of the Eletrobrás-Eletronorte on 500/230 kV was modeled in Alternative Transient Program (ATP) using real parameters. The Wavelet Transform, through multiresolution analysis (MRA), it’s used because its time domain localization characteristic to allow characterizations of electromagnetic transitory moments caused by contingencies. The waves generated by faults traveling towards the line’s terminals containing the wave propagation times from defect point at the terminals and these times can be conveniently extracted for such transformed. By means of the methodology adopted in the algorithm, the difference between those times determines the fault occurrence place on the line with good accuracy. However, one of the error variant agents in the estimation it’s the selection of the wavelet used in MRA of the signals, therefore the evaluation of that choice upon those errors, the main objective of this work, it’s justified for the still inexistent scientific bases that assure the choice of a great wavelet to a certain application. Among a diversity of discrete wavelets, appropriated results were obtained for 16 of them with maximum errors smaller than 250 meters, stipulated precision adopted. Two wavelets, Db15 and Sym17, were more exact than the others, respectively, 3.5 and 1.1 times. The methodology to get those results consists of the: export of the fault data files from ATP for MATLAB®; application of the Clarke’s modal transformation of voltages; decomposition of alpha modes and synthesis of the levels 1 of details through AMR; calculation of their maximum magnitudes and time indexes determination; finally, the traveling waves theory is used to formulate the estimate equation of the contingency place on the line. All methodology was programmed in MATLAB and the errors’ statistical analysis was made in Microsoft Excell®. At the end, a GUI (Guide User Interface) for (Human Machine Interface) HMI of locator was elaborated, which is also a graphical analysis interface, no matter which the contingency applied to the EPS. The attained results demonstrate an improved performance in reason of the most appropriate wavelet selection to the algorithm and they suggest a practical application of the locator.Item Acesso aberto (Open Access) Modelagem e controle de uma incubadora neonatal(Universidade Federal do Pará, 2013-08-08) BRAGA JÚNIOR, Gilson Fernandes; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453This work presents an introduction about neonatology history, the concept and mathematical modeling of a neonatal incubator’s thermal system, with its thermal exchanges relations to an infant by the first law of thermodynamics. The method used for linearization (Taylor series) it is showed and the operation points calculated to the linear system obtained in the state space format, and then a representation in transfer function format. By the system’s mathematical modelling, an open loop test was done to verify the model behaviour, as characteristics of stability, time constant and convergence to a desired final value, and how the system operates at closed-loop, the system on this configuration was tested with the usage of an unitary gain. The behaviour of the non linear system was compared to the linearized system through their time response curves at a presence of a degree input to the verification of the linearized representation validity, and after the validation, bode diagrams were generated to different model parameters, to notice the effect of this variation on the model’s dynamic behaviour, and was observed that the model’s behaviour do not vary at a substantial form inside the verified ranges of values. A proportional and integral (PI) controller then was designed to eliminate the steady-state error present at the system’s time response. Tests under few operating conditions were done at the linear representation and the temperature variation curves were obtained with the controller applied to the non linear model, and the results were considered satisfactory to this kind of application. This work was made with the assistance of computational tool Simulink of the software Matlab®.Item Acesso aberto (Open Access) Projeto de um controlador Fuzzy Takagi-Sugeno para uma estação de tratamento de esgoto por lodos ativados(Universidade Federal do Pará, 2013-01-24) OLIVEIRA FILHO, José Haroldo Sena de; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453The mean goal of this work is the design of a Takagi-Sugeno fuzzy controller on an activated sludge wastewater treatment plant. This kind of process requires oxygen and aerobic microorganisms in the mixed liquor that are necessary to remove the carbonaceous matter and the nutrients based on nitrogen compounds. The controller acts on the aeration valve engine and has been designed to interpolate the proportional and integrative gain of three fixes controllers designed from the linearization of a continuous model of oxygen mass balance. The controller assists to keep the desirable dissolved oxygen concentration necessary to the nitrification, an oxi-reduction chemical reaction that transforms ammonia into nitrite and it is also possible to save electric energy used by the aeration engine. It is imperative the nitrification occurs for the success of the whole process. The Assays were performed by computerized simulation in four idealized scenarios analyzing the performances of the fuzzy controller and the fix controller designed to a different operation point of the set point defined in the plant. Applying a degree in the set point established in the scenario it was analyzed the rise time, settling time, overshoot and steady-state error. After the assays, the fuzzy controller performed better than the fix one at rise time and settling time criteria and equivalent performance at overshoot and steady-state error. After analysis, it was conclude that the control strategy chosen in the work is viable, according the dissolved oxygen measure at the plant entrance, the fuzzy controller interpolate the proportional and integrative gains of a fix controller designed near this value and thus act quite satisfactory.Item Acesso aberto (Open Access) Redução de ordem de modelos matemáticos lineares usando algoritmos genéticos(Universidade Federal do Pará, 2012-08-07) FERREIRA, André de Oliveira; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453This dissertation presents the order reduction problem of dynamic models, from the optimization viewpoint by genetic algorithm. An objective function, obtained from the norm of the coefficients of the numerator of the error transfer function among the original and reduced model, is minimized by a genetic algorithm, with consequent calculation of the parameters of the reduced model. The procedure is applied to some examples that demonstrate the validity of the approach.Item Acesso aberto (Open Access) A redução do consumo de energia elétrica em Manaus através de medidas de eficiência energética em climatização industrial(Universidade Federal do Pará, 2011-02-28) SILVA, Jorge Lúcio da; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453The dissertation has as objective that is to evaluate the consumption of industrial electric industries in the Pole of Manaus – AM (PIM), through using the electric optimizing efficient energy with (EE), with based models comparison in the consumption of electricity consumed by the PIM. The study was based in accordance with national rules of industrial climate control technical standards established. It also measures the (EE) since it was used through replacement of the air conditioners window style of low efficiency, for equipments of high performance. The use of estimated thermal loads resulted in the application of electrical measurements, in which were obtained by evaluating the EE that allowed us to find mechanisms of linguistic variables that solved and enhance the capabilities of air conditioners, where they controlled both simultaneously the temperature, humidity, movement, and the purification of indoor air with in the Brazilian Television industry (IBT)To minimize the costs, we made analysis of programmed actions with calculation by tools through inference that provided the followings results: Control of the external sources of hot or cold, and verification of losses in the pipes and also losses in the environments, and adjust the temperature of thermal comfort, Such as environment and system utilization, and utilization control system for optimum use of equipment with thermo bank accumulation of ice or water which (EE)Measures have to be quantified of their consumption and savings to reduce electricity demand In their actual impacts of the company.Being so the results permitted a reduction of saving cost near about R$ 14.299,73 in actual eight months studied and representing a percentage of 7.32% savings for the company in its energy consumption amounting to a cost of R $ 1,787.46 a month showing real satisfactory outcome within the costs set by the IBT.Item Acesso aberto (Open Access) Sintonia de controlador fuzzy por algoritmo genético em sistema de nível de líquidos(Universidade Federal do Pará, 2014-03-31) ANDRADE, José Flávio Barbosa de; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453This work presents the application of a Genetic Algorithm in order to design a MISO Fuzzy Controller by tuning its parameters in an experimental process of leveling liquid in a tank whose dynamics has nonlinear characteristics. In the Fuzzy Controller design and tuning it was used the software Matlab and their packages Simulink and Global Optimization Toolbox. The Fuzzy Controller designed had its performance evaluated by a real time test in a Liquid Level System.Item Acesso aberto (Open Access) Um ambiente colaborativo de aprendizagem interdisciplinar apoiado por interfaces adaptativas(Universidade Federal do Pará, 2006-12-07) LIMA, Paulo Sérgio Rodrigues; SILVA, Orlando Fonseca; http://lattes.cnpq.br/7387718587227127; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453The use Virtual Learning Environment (VLE) becomes, day by day, more evident in several public teaching institutions, as well as in private and government agencies. Several versions of VLEs are available for free use, each one under its own characteristics. In Brazil there are almost a thousand institutions that have been using these environments, which show the necessity of investments and new research in this area. This theses specifies and develops a VLE, its main objective is to reduce the problems found in many approach of the environment ready for use thus recommending an environment called "Interdiscipline Collaborative Learning Environment" which was prepared to offer an infra-structure which permits to unite cooperative working concepts, learning virtual communities, interdiscipline, interfaces adaptation and in a complementary way allow creation of automatic recommendations to its users based on their profiles.