EMC - Escola de Engenharia Elétrica, Mecânica e de Computação
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A Escola de Engenharia Elétrica, Mecânica e de Computação (EMC), da Universidade Federal de Goiás, oferece Graduação em: Engenharia Elétrica, Engenharia Mecânica e Engenharia da Computação. Além de Especialização em: Telecomunicações; Instalações Elétricas; e, Gestão de Negócios.
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Item Análise do fator de potência em instalações elétricas contendo geração solar fotovoltaica(Universidade Federal de Goiás, 2023-07-21) Rezende, Gabriel Portella; Dias, Dayanne Ferreira; Oliveira, Janine Cavalcante de; Belchior, Fernando Nunes; Castro, Marcelo Stehling; Belchior, Fernando Nunes; Santos, Josephy Dias; Oliveira, Janine Cavalcante deThe main objective of this study is to analyze the power factor in electrical installations that incorporate solar photovoltaic generation systems. Distributed generation of electricity through photovoltaic systems has gained increasing importance due to its capacity to produce clean and renewable energy. However, the integration of these systems into existing electrical grids can present challenges, such as the impact on the power factor. Therefore, this study proposes a detailed examination of the effects of generation on the power factor in electrical installations. For this, measurements and analyses will be conducted at the Centro de Aulas das Engenharias building during November 2022 to obtain concrete data and support the study's conclusions. The expected results of this work will contribute to a better understanding of the effects of photovoltaic systems on the power factor and provide guidelines for the design and operation of electrical installations that include solar generation. This aims to optimize the use of electricity, reduce losses, and increase the energy efficiency of these installations.Item Análise modal estática aplicada ao problema de fluxo de carga em coordenada retangular para avaliação de estabilidade de tensão(Universidade Federal de Goiás, 2024-02-02) Sena, Katarina Leite de; Santos, Vinícius Morais Calixto dos; Brigatto, Gelson; Kopcak, Igor; Kopcak, Igor; Alves, Antônio César Baleeiro; Garcés Negrete, Lina PaolaA voltage instability is a phenomenon directly linked to the inability of an electrical power system to meet its demand for active power, caused by inadequate reactive power support. Traditionally, voltage stability margins are calculated through static methods based on the load flow problem. Additionally, Static Modal Analysis has been a tool foridentifying critical buses or areas regarding voltage stability. This methodology uses the representation of voltage phasors in cylindrical or polar coordinates. In contrast, this study proposes applying Static Modal Analysis to the Jacobian of Load Flow in Rectangular Coordinates, where voltage phasors are represented by their Cartesian coordinates on the real and imaginary axes. The aim was to assess whether this new approach could provide additional qualitative information for identifying critical buses regarding voltage stability, complementing traditional Static Modal Analysis. For the analysis of results, well-known transmission networks from the literature were employed, and for comparing the performance of the methods developed in this study, Static Modal Analysis in polar coordinates was adopted as a reference. The results obtained demonstrate that the method developed in this study is satisfactory, as the provided voltage stability margins are close to those of the traditional method, and the Static Modal Analysis applied to Rectangular Load Flow classified the critical buses of the tested systems correctly.Item Atualização de planta de instalação elétrica industrial(Universidade Federal de Goiás, 2024-02-02) Araujo, Vitor Montero; Araujo, Bruno Alves de; Alvarenga, Bernardo Pinheiro de; Alvarenga, Bernardo Pinheiro de; Santos, Euler Bueno dos; Paula, Geyverson Teixeira deAll elements of a building undergo changes over the years, to a greater or lesser extent, the original characteristics are altered and not recorded, making it difficult to understand for those who did not participate in the processes. This is especially complex for electrical installations, as the addition of new equipment, jobs, and other changes bring problems that can lead to accidents, such as an increase in load beyond what the circuit was designed to handle, generating excessive heating. Renovating a building is a great time for all these issues to be resolved. This is the case of Mercabox Araujo, a supermarket company that is undergoing an expansion that will double its area, a situation that requires the renewal of its entire electrical installation to support the new installed power and a new layout to meet future activities. This final project aims to propose the design of the new Mercabox Araujo installations, taking into account the customer's demands and compliance with the standards that govern low voltage installations, ensuring reliability and safety. Furthermore, a step-by-step guide was also proposed so that the transition between the old and new installation does not cause disruption to the company's activities, which will continue to operate during the works.Item Avaliação no ATPDraw das proteções diferencial e de sobrecorrente aplicadas a um transformador de potência(Universidade Federal de Goiás, 2024-08-01) França, André Luiz Almeida de; Almeida, Maria Leonor Silva de; Almeida, Maria Leonor Silva de; Brigatto, Gelson Antônio Andrêa; Kopcak, IgorThis work analyzed the differential and overcurrent protections in ATPDraw for a YDn1 power transformer, with the high-voltage side connected in a grounded wye configuration and the low-voltage side in delta. The protections were implemented in ATPDraw with differential protection blocks (87T), instantaneous overcurrent (50), and time-delayed overcurrent (51). Phase overcurrent functions (50F/51F) and neutral overcurrent functions (50N/51N) were incorporated on the high-voltage side. In 87T block of ATPDraw, it was necessary to include the zero-sequence compensation and angular correction. Faults were simulated on the transformer’s busbars and bushings, covering conventional and internal faults caused by short circuits turn-to-turn and turnto-ground. The 50F and 51F functions demonstrated effectiveness and selectivity in responding to faults on the bushings and busbars. The 50N and 51N functions operate to ground faults, except for those on the low-voltage side, as the delta connection prevents the high-voltage side from contributing to zero-sequence components generated by ground faults. Additionally, the 50N and 51N functions responded quickly to turn-to-ground short circuits in the grounded wye configuration. However, none of the overcurrent functions could defect turn-to-turn or turn-to-ground faults on the delta-connected windings. The differential protection 87T, with zero-sequence compensation and angular correction, performed well for faults on the busbars and bushings. However, it required a high percentage of short-circuited turns on the low-voltage side to operate, specifically 90% for turn-to-ground short circuits and 65% for turn-to-turn short circuits. Therefore, it was recommended that the relay sensitivity be increased by adjusting the slope of the second region to enhance fault detection on the delta side.Item Coordenação de proteção e seletividade em redes de distribuição com penetração de geração distribuída(Universidade Federal de Goiás, 2024-08-02) Lobo, João Pedro do Carmo; Pacheco, João Victor Miranda; Kopcak, Igor; Kopcak, Igor; Sena, Carla Silva; Almeida, Maria Leonor Silva deThe work presents a detailed study on the coordination of protection and selectivity in electrical distribution networks with distributed generation, focusing on a 1 MW Small Hydroelectric Power Plant (CGH) located in the interior of Goiás. The study includes the analysis of critical operating scenarios, equipment specification, protection functions, and the parameterization of protection relays. The necessary adaptations to ensure safe and coordinated operation with the utility's protection devices, such as substation relays, reclosers, and fuses, are addressed. The main objective is to highlight the importance of selectivity and coordination in the protection system, especially considering the increasing penetration of distributed generation, which introduces additional challenges such as bidirectional current flow and variations in voltage and frequency levels. This encompasses the need to adapt the parameters of protection relays to maintain selectivity and avoid improper operations that could compromise the continuity of energy supply. The detailed analysis of operating scenarios takes into account different fault conditions and the influence of distributed generation on these events, providing an in-depth understanding of how distributed generation can impact the operation of distribution networks. The specification of equipment and protection functions is carried out in a way that ensures relays operate in a coordinated manner, both with the CGH equipment and with the devices in the distribution network. Correct parameterization of the relays is essential for them to adequately discriminate fault types and act selectively, ensuring system protection and minimizing interruptions. The study highlights the importance of implementing practices and standards that consider the particularities of distributed generation, ensuring reliable and efficient operation of the electrical system.Item Desenvolvimento de software destinado à análise de custos de energia elétrica em unidades consumidoras do grupo A e grupo B(Universidade Federal de Goiás, 2024-07-16) Esperidião, Rodrigo Santana; Belchior, Fernando Nunes; Belchior, Fernando Nunes; Oliveira, Antônio Melo de; Castro, Marcelo Stehling deUnderstanding how charges related to the use of electrical energy in an installation are made is essential for good expense management of this resource, as it allows identifying ways to reduce the costs arising from its use. Although there are several energy distributors in Brazil, all of them are subject to the rules and resolutions established by ANEEL, which implies standardization of energy billing. This work aims to detail the development of a web application intended to assist in the study of costs related to the use of electrical energy in Brazilian consumer units. The program combines HTML and CSS elements with its main code written in Python. The unit's profile and simulation results are presented as numerical values and graphs in Excel spreadsheets. The software has two analysis models: load analysis, where the unit's weekly consumption profile is analyzed according to the installed loads and their usage times; and bill analysis, where the data present in the electricity bill for 12 months of the unit's operation are interpreted. The analyses aim to clearly present the unit's consumption profile and identify possible cost-saving opportunities through tariff reclassification or contracted demand alteration. In load analysis, the ideal tariff modality for the unit's profile is verified, and for Group A consumers, the presence of costs with reactive elements is studied, as there is no such charge for Group B consumers. In bill analysis, the program addresses only Group A units, recommending the ideal contracted demand, the appropriate tariff modality, and presenting the estimated savings if the consumer adopts the suggested measures. Five case studies were conducted to validate the results generated by the application: three focused on load analysis and two on bill analysis. The first four studies evaluated the results and identified the causes of any observed differences, while the last consisted of a practical study, applying the tool to analyze a consumer unit at the Federal University of Goiás. The software proved to be efficient, generating consistent results with small or no errors in most cases.Item Emprego de inteligência artificial na identificação de parâmetros eletromagnéticos de motores elétricos(Universidade Federal de Goiás, 2024-07-22) Matos, João Pedro Aguiar Formiga; Vieira, Pedro Paulo Carvalho; Paula, Geyverson Teixeira de; Paula, Geyverson Teixeira de; Brito, Leonardo da Cunha; Santos, Guilherme Fernandes dosThis work investigates the development of an artificial intelligence application to identify electromagnetic parameters in electric motors. Using the FEMM software, a dataset of magnetic flux curves by current for various ferromagnetic materials was created, serving as the basis for training neural networks. These networks were able to determine the equation of these curves from a minimal number of points, regardless of the material type, implying possible improvements in the efficiency and performance of electric motors.Item Estimação de distâncias de objetos em imagens de câmeras monoculares utilizando medes neurais profundas(Universidade Federal de Goiás, 2024-08-01) Caraíba, André Felipe dos Santos; Cardoso, Álisson Assis; Cardoso, Álisson Assis; Vieira, Flávio Henrique Teles; Lopes Filho, GilbertoItem Estudo de transitórios eletromagnéticos por meio de simulações nos softwares Simulink/MATLAB e Script/MATLAB(2024-08-01) Castro, André Luiz Martins; Ferreira, Lara Rebeca Alcebíades; Almeida, Maria Leonor Silva de; Almeida, Maria Leonor Silva de; Kopcak, Igor; Belchior, Fernando NunesThis final graduation project examines electromagnetic transients in systems modeled as RL and RLC circuits. Initially, the switching of an RL circuit with two resistors, two inductors, and a voltage source is analyzed. The initial analysis occurs before the switching, with no circulating current for the ground fault, considering the circuit as a resistor in series with an inductor and a voltage source. After switching, the circuit is divided into two parts: one with the voltage source and the other with only a resistor and an inductor in series. Subsequently, the study addresses the switching of a series RLC circuit with a voltage source. Initially, there is a switching between the source and the RLC circuit, which generates a current composed of a homogeneous solution and a particular solution. The graphs of natural frequency and damping in different phases of the voltage source are analyzed. Additionally, an analysis of the graphs of the magnitude and phase of the equivalent impedance of the RLC circuit is performed. The study explores fundamental concepts of RL and RLC circuits, highlighting the implications of the resistor on the system's response, such as the dissipation of transient energy. Furthermore, the importance of choosing component values is emphasized, as they directly affect the circuit's response. Analyses are conducted using MATLAB software with its Script and Simulink work environments. In the Script method, the circuit's mathematical equations and provided values are used, generating graphs for the analysis of steady-state and transient currents. Simulink allows for the drawing and simulation of the circuit, obtaining relevant graphs for the analysis. The project contributes to the understanding of electromagnetic transients, their causes and impacts, and the importance of effective protection measures. It demonstrates the application of numerical methods and simulation tools to study transient behavior in electrical circuits, providing a solid foundation for future research and practical applications in electrical engineering.Item Estudo de viabilidade de implementação de pontos de recarga de veículos elétricos em condomínio residencial(Universidade Federal de Goiás, 2024-01-17) Santos Neto, João Victor; Santos, Thales Moreira; Paula, Geyverson Teixeira de; Paula, Geyverson Teixeira de; Garcés Negrete, Lina Paola; Lima, Wilmar Alves CruvinelOver the past 13 years, we have observed a steady increase in the number of electric vehicles circulating in Brazil. This scenario presents a significant challenge for buildings to meet the demand of residents. This study aims to analyze the feasibility of demand for the implementation of electric vehicle charging stations in established residential condominiums. To achieve this, a case study was conducted in a high-end building in Goiânia, where a device called an energy analyzer was used for data collection. A crucial point for the study was the analysis of projected and calculated demands. The study results included the implementation of up to 4 semi-fast charging station points (22kW) and a simulation of load increase, along with the transformer replacement for a future adaptation of the building to serve the entire condominium. NT-042 and NT-02 were used for the transformer calculation.Item Integração de usinas solares fotovoltaicas e eólicas de grande porte em sistemas de transmissão de energia elétrica(Universidade Federal de Goiás, 2023-08-22) Rasteli, João Gabriel Teixeira; Garcés Negrete, Lina Paola; Garcés Negrete, Lina Paola; Silva, Fernando Carvalho Assunção da; Kopcak, IgorAbstract—This article addresses the assessment of the impacts of integrating large-scale photovoltaic and wind power plants into the electric transmission network. To accomplish this, computer simulations based on the Monte Carlo Method were conducted. The simulations consider the probabilistic variation of the primary resource of the energy sources, solar irradiance, and wind speeds, in order to calculate the output powers of the plants. Three power electrical systems found in technical literature were analyzed: Chesf Simplified 5-bus, IEEE 9-bus, and IEEE 14- bus. For each simulated system, the average values of energy losses, voltage levels, as well as the average values of generation from renewable plants are obtained and analyzed. The results demonstrated that the additional generation from the plants can reduce the total active energy losses in the system, especially when they are located close to the loads, thus avoiding the transmission of energy over long distances. However, for one of the tested systems, an increase in average active energy losses was observed, which may be due to the consequential effects of reverse power flow in the branches connecting the allocation bars of the plants, which were randomly selected. The voltages at the bars were also evaluated, showing an increase in maximum voltages, but within recommended limits. Therefore, it is concluded that the integration of large renewable plants into transmission systems requires careful planning involving optimization techniques for their allocation and sizing, in such a way as to avoid undesirable impacts on the electrical system.Item Métodos DLF e MSP retangular com modelo de carga ZIP: formulações, testes e comparações(Universidade Federal de Goiás, 2023-08-18) Mattar, João Vitor Oliveira; Kanashiro, Mauricio Kenichi; Brigatto, Gelson Antônio Andrêa; Brigatto, Gelson Antônio Andrêa; Garcés Negrete , Lina Paola; Kopcak, IgorThe modeling of electrical systems normally considers the load data as independent of the bus voltages, such that loads are modeled as constant power and classic methods of solving subsystem 1 of the load flow problem are based on this consideration. However, the constant power model may not satisfactorily represent the behavior of different loads, as this consideration is more appropriate in case that the bus voltages remain equal to their respective nominal values. Despite this, in the need for a more comprehensive approach to the behavior of the loads of the electrical network under study, the ZIP model can be adopted to represent loads as dependent on the module of the bus voltages, which makes it necessary to adapt solution methods to consider the ZIP payload model. This work aims to develop the formulation of two solution methods for subsystem 1 of distribution networks considering the ZIP load model: the direct load flow method and power sum method in rectangular version. For analysis of results, distribution networks known from literature were used and, for the performance comparison of the methods developed in this work, the power sum method was adopted in the version in polar coordinates with ZIP load model. The analysis of the results show that the performance of the formulations developed in this work are similar to the polar power sum method in terms of the number of iterations, but are inferior in terms of processing time of the final solution.Item Projeto de rede usando fibra ótica: FTTH residencial(Universidade Federal de Goiás, 2024-07-19) Vilarinho, Ana Júlia Batista; Fernandes, Pedro Henrique Oliveira; Castro, Marcelo Stehling de; Castro, Marcelo Stehling de; Valle, Ana Cláudia Marques do; Rocha, Flávio Geraldo CoelhoThis article discusses Fiber to the Home (FTTH) network projects with a focus on Gigabit Passive Optical Network (GPON) technology, exploring technical aspects such as architecture, components, and protocols. It integrates various knowledge studied in the Engineering course, applying them in practice. FTTH technology stands out as a paradigmatic evolution in contemporary communication networks, transmitting data directly to residences via optical fibers. Its relevance lies in its ability to provide highspeed, reliable, and symmetrical connectivity, playing a crucial role as a catalyst for digital transformation. The operation of FTTH involves the transmission of optical signals converted from electrical signals, using a point-to-point architecture that starts at optical centers, ensuring efficient bandwidth distribution to residences. This transmission culminates in the inverse conversion of optical signals back to electrical signals at the destination point. In addition to providing Internet access, FTTH enables various applications such as subscription television, telephony, and emerging technologies, including virtual and augmented reality. The robustness and wide bandwidth capacity of FTTH consolidate it as an enabling infrastructure for advanced digital services, promoting enriching digital experiences that positively impact users’ daily lives. In summary, FTTH emerges as an integral technology for expanding digital connectivity, based on its strategic importance, sophisticated operation, and diversity of applications that transcend conventional limits of digital communication.Item Proposta de projeto e estimativa de regimes de operação de sistema fotovoltaico isolado para suprimento de cargas auxiliares em subestação de transmissão de energia elétrica(Universidade Federal de Goiás, 2023-08-21) Barros, João Vitor Menezes Carvalho; Correa, Vitor Hugo Castilho; Marra, Enes Gonçalves; Pimentel , Sérgio Pires; Pimentel, Sérgio Pires; Marra, Enes Gonçalves; Bousquet, Marcelo Nogueira; Nerys, José Wilson LimaThis study is based on the dimensioning of an isolated photovoltaic system (SFV) for the supply of energy to feed loads of auxiliary services of a substation as the main scope to be achieved for the work. In order to reach the desired objective, as a methodology, a case study was carried out in a substation in the municipality of Trindade, in the State of Goiás. In order to guarantee the supply of energy to the auxiliary loads for a longer period of time, the design of an energy storage system based on lead-acid batteries. As a result, it was possible to observe that the implementation of the photovoltaic system guarantees an additional source of redundancy to feed the auxiliary loads, contributing to the continuous operation of the substation protection and operation system.Item Sistema de aquisição de dados de baixo custo utilizando Arduino(Universidade Federal de Goiás, 2023-08-16) Caixeta, Eduardo Martins de Carvalho; Carvalho, José Humberto Ferreira Ramos; Cardoso, Alisson Assis; Cardoso, Alisson Assis; Souza, Gustavo Souto de Sá e; Nerys, José Wilson LimaCurrently, most residential appliances have electrical devices that have well-defined properties. These are the scope of study of countless electrical engineering students. Even if these devices are easy to handle, the studies of the systems and devices that compose them require an in-depth analysis, and to carry out this analysis the use of measuring instruments is essential. Some of these devices are known, such as the multimeter, voltmeter, ammeter and oscilloscope. These devices are very ef icient and have a range of utilities, as well as being very precise, showing the indication of one or more characteristic parameters, such as ef ective value, peak value and frequency of magnitudes such as voltage and current. Therefore, it is clear that the oscilloscope’s acquisitiont is mandatory for engineering students, so this document presents the operating principles of the oscilloscope and a basic model made with the use of common software and devices frequent in laboratories and research rooms. of engineering schools. Furthermore, the development of this oscilloscope is intended to collaborat with the practice of research and study in the laboratory.