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Dissertations |
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1
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MARCOS ANTONIO DE ARAUJO SILVA
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Optimization of the Relay Parameterization in Radial Distribution Systems Using Genetic Algorithm
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Advisor : MAX CHIANCA PIMENTEL FILHO
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COMMITTEE MEMBERS :
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ARRHENIUS VINICIUS DA COSTA OLIVEIRA
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MAX CHIANCA PIMENTEL FILHO
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RODRIGO PRADO DE MEDEIROS
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Data: May 2, 2018
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Show Abstract
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Power concessionaires are now seeking to expand and modernize power systems in the face of new consumer demands and requirements established by ANELL. The protection of electrical systems plays a fundamental role in the maintenance of this system and in the control of its indicators. Distribution systems have several physical and technical characteristics, such as the operating time of the devices, load flows and short circuit levels. In view of the great diversity of these systems, the construction of a computational algorithm that assists in the mathematical procedures of system parameters, or even that, generate a previous automatic configuration of the devices is necessary in view of the wide demand offered to the protection engineers. The algorithm was initially modeled in order to determine the short circuit currents in each primary protection device, as well as to calculate the minimum currents of operation of the time overcurrent units and the timing adjustments of the relays. Due to the great universe of possibilities of adjustments offered by the code, evolutionary biology techniques were used, in order to choose in this population of possibilities the individual that makes the parameterization of this optimized system. If in the first generation the chosen individual does not match the optimal function, this population will be evolved from the procedures of natural selection, crossing and mutation of the individuals, present in the evolutionary techniques used in the algorithm. It is expected that genetic coding when applied to microprocessor devices with appropriate time interval characteristics according to standards, the algorithm is efficient and stable. However, for feeder circuits where the equipment timing is inadequate for a reliable study of coordination and selectivity, a change of the initial timing parameters will be suggested. If the absolute operation time of the feeder is minimized the procedure performed by the algorithm will be considered valid and the configuration presented at the end will be the best among all the population.
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2
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ÍTALO JOSÉ LOPES DE ALMEIDA
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ANALYSIS OF THE GENERATION OF ELECTRICAL ENERGY THROUGH BIOMASS OF SUGAR CANE: A CASE STUDY
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Advisor : MAX CHIANCA PIMENTEL FILHO
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COMMITTEE MEMBERS :
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JOSE LUIZ DA SILVA JUNIOR
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MAX CHIANCA PIMENTEL FILHO
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NEILTON FIDELIS DA SILVA
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Data: May 30, 2018
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Show Abstract
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The production of electric power constitutes a major part of the economic growth plan of any nation. Relative to other nations, Brazil possesses key advantages since the design of its energetic matrix can be based on abundant renewable sources. One such source, the focus of this work, is the biomass of the sugar cane, which is used in the cogeneration of power that strengthens the Brazilian matrix. Although long available, note that this source of energy has been underutilized in the commercial production and distribution of electric power. The Program for the Incentive of Alternative Energy sources (Programa para of Incentivo `as Fontes Alternativas de Energia, PROINFA), established by the Federal Government in 2002, but extinct today, and the rise of market for carbon credits triggered by the Kyoto Protocol, improved the situation in the last decade. Indeed, during this period, the sugar-cane biomass has been used more intensely, emerging as an important component of the Brazilian energetic matrix. This dissertation analyzes data related to the harvest/milling and the amount of electric power exported from a sugar-cane alcohol based thermoelectric plant that sells electric power in an environment of regulated contraction (ERC) and in an environment of free contraction (EFC), which is derived from sugar-cane bagasse. It was verified that using the bagasse as the sole source of fuel, it was not possible to supply the yearly amount of power that had been agreed upon with various electrical power companies. Therefore, new calculation were made to add the straw with the bagasse to increase the power production at the end of the cycle. It is concluded that the combined bagasse-straw used as the fuel for the plant would provide a significant increased to the exported power, achieving the annual goals, and considerably increasing the profits due to the sale of electric power.
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3
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JAQUELINE PEREIRA DA SILVA
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PROJECT OF MODERNIZATION OF THE SYSTEM OF MEASUREMENT AND CONTROL OF ENERGY OF THE CENTRAL CAMPUS OF UFRN
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Advisor : MARCOS ANTONIO DIAS DE ALMEIDA
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COMMITTEE MEMBERS :
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MARCOS ANTONIO DIAS DE ALMEIDA
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JOSE LUIZ DA SILVA JUNIOR
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FRED SIZENANDO ROSSITER PINHEIRO
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JOABSON NOGUEIRA DE CARVALHO
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Data: Jun 19, 2018
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Show Abstract
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This work consists in the development of a project to modernize the energy measurement and control system of the central campus of UFRN, using the industrial fiber optic network for data communication. Currently the university has a system of measuring consumption and the phenomena that influence the quality of energy, composed of 76 equipment, which attend to various buildings, linked to the electrical feeders of these buildings. A percentage of the measuring equipment is in operation and another part damaged or not communicated with the OIC-Operation and Information Center. In the present project, the efforts will be directed to evaluation and diagnosis of the measurement and control equipment, existing means of communication, design for the buildings not served and complementation of the data network. At the end, a descriptive memorial and cost forecast will be made available for system modernization. With the execution of the project, the university will have a valuable management tool that will send the information in real time to OIC, allowing control, management and sectorization of electric energy consumption. This can be carried out by apportioning costs, analyzing demand, quality of energy and saving by reducing costs.
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4
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FRANCISCO DAVID MOTA SILVA
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Project of MINIGERATION of electric power through the photovoltaic system in military land organizations-center of intending navy in NATAL (CEIMNA)
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Advisor : RICARDO FERREIRA PINHEIRO
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COMMITTEE MEMBERS :
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JOSE TAVARES DE OLIVEIRA
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RICARDO FERREIRA PINHEIRO
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GABRIEL IVAN MEDINA TAPIA
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RENATO SAMUEL BARBOSA DE ARAÚJO
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Data: Jul 5, 2018
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Show Abstract
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This work deals with solar photovoltaic generation. Due to the growing energy demand of military institutions and the need for energy consumption models that require less financial resources, the work proposes a reduction of electric energy costs with the installation of a solar photovoltaic mini-plant connected to the electric power grid. A power generation system based on the solar source is designed for the self-consumption of a pilot unit, integrated a power management system in which it will be possible, in the expansion, to identify the profile of the load curve of the unit under study allowing the total management of the measurement point and improvement of the management of the apportionment of energy bills in each Military Organization installed in the territory of BNN (Naval Base of Natal). The premise considered is the energy self-sufficiency of the building using the solar resource as a source of electric energy and thus follow the guidelines of the project CON ENERGIA of the Brazilian Navy that is structured in three pillars: Free Market, Energy Efficiency and Distributed Generation . This system has several advantages, among them the use of solar energy and reduction of greenhouse gas emissions, reduction of electric energy bill and reduction of electric losses with transmission, due to generation being close to consumption . The proposed system is designed to compensate for all pilot power consumption and an installed power of 165 kWp has been established. The basic components of the generation system and a three-dimensional modeling of the generation plant are detailed, as well as an economic feasibility analysis of the project.
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5
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JOALE DE CARVALHO PEREIRA
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Computing Program for Sizing systems Electricity generation from biogas, with application In the sewage treatment plant of the BALDO/CAERN
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Advisor : RICARDO FERREIRA PINHEIRO
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COMMITTEE MEMBERS :
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GABRIEL IVAN MEDINA TAPIA
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MANOEL FIRMINO DE MEDEIROS JUNIOR
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PAULO EDUARDO VIEIRA CUNHA
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RICARDO FERREIRA PINHEIRO
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Data: Jul 6, 2018
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Show Abstract
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The present work was thought due to the great necessity of insertion of renewable sources of electric energy generation in the world energy matrix, more specifically, in the use of the available thermal energy in the biogas. This use, in addition to providing energy, adds benefits to the environment, because when not used, often biogas is released directly into the atmosphere, being very aggressive to the environment. In this proposal, biogas is used in internal combustion engines to drive electric generators. As a way to enable a better use of biogas production, a software, SAGGAS, was developed. Through the volumetric flow data of the biogas, its properties and technical characteristics of the installation, the SAGGAS simulates the operation of the generation system and determines a combination of generators that allows to maximize the generation of energy and the financial return. The program was applied to the Baldowastewater treatment plant, located in the city of Natal/RN and owned by the CAERN. The generation potential and economic viability of the investment were determined taking into consideration the associated costs, the energy to be made available for the installation and the surplus that will be injected into the distribution network.
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6
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HEITOR BRENO SILVA BEZERRA
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Survey and Diagnosis of Environmental Refrigeration Systems and Energy Efficiency Improvement Proposals for Buildings of the UFRN Central Campus
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Advisor : JOSE LUIZ DA SILVA JUNIOR
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COMMITTEE MEMBERS :
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ALDAYR DANTAS DE ARAUJO JUNIOR
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CRISLUCI KARINA SOUZA SANTOS CANDIDO
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JOSE LUIZ DA SILVA JUNIOR
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Data: Jul 13, 2018
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Show Abstract
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Over the last few years, the UFRN has been receiving new air conditioning installations, to offer thermal comfort to those who use these environments and also to increase productivity. On the other hand, it was observed the considerable increase in the consumption of electric energy in the Central Campus, being necessary to take measures related to the rational use of these equipments.
Since 2013, in some buildings of this university, the VRF (Variable Refrigerant Flow) system has been installed in some buildings. This system guarantees, in addition to the lower electricity consumption, better thermal comfort when compared to other air conditioning technologies, even though it is more expensive to implement.
The VRF system is one of the greatest technological innovations for environmental conditioning, having the high energy efficiency, thanks to its characteristics and possibility of remote management, offering the best operational control of the machines connected to the network interface.
The main characteristic of the VRF system is the high energy efficiency, since the system has multiple controllers, in order to guarantee the smooth operation of the machines and better distribution of the thermal load, thus avoiding perceptible temperature fluctuations within an environment.
This study proposes to verify, from electrical measurements and analysis of investments and indexes related to energy quality, the feasibility of adopting the VRF in the Central Campus of this university, being part of the technological innovation process related to air conditioning due to the new solutions that the system proposes to the users of these installations, related to the comfort and, mainly, the energy efficiency.
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7
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EGBERTO DE ARRUDA MOREIRA
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Application of Hybrid Reclosers in Electricity Distributions Networks
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Advisor : ARRHENIUS VINICIUS DA COSTA OLIVEIRA
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COMMITTEE MEMBERS :
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ARRHENIUS VINICIUS DA COSTA OLIVEIRA
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MARCOS ANTONIO DIAS DE ALMEIDA
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MAX CHIANCA PIMENTEL FILHO
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ALDAYR DANTAS DE ARAUJO JUNIOR
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Data: Jul 30, 2018
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Show Abstract
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The necessity to maintain the quality indicators of electricity supply, DEC (Equivalent Duration of Interruption per Consumer Unit) and FEC (Equivalent Frequency of Interruption per Consumer Unit), both required by ANEEL (National Agency for Electric Energy) has never been so imperative for the electric power utilities companies. Year after year these indicators become increasingly demanding. Besides, in a natural way, the electrical system only tends to grow and become more complex, consequently bringing more technical challenges to the Protection, Operation and Maintenance (O & M) areas of Distribution Networks (DN). A Distribution Network, also known as a feeder, when shows characteristics such as small dimension, densely charged and with a high level of short-circuit current in the substation busbar (SS), is an example of challenging condition to ensure coordination and selectivity between the circuit protection devices. This panorama is especially difficult for the protection when there is a consumer of Group A (e.g. 13.8 kV) connected at the end or near the end of this type of feeder. With the significant investments made in recent years by electric power utilities for the acquisition and installation of reclosers (RL) in the DNs, in practice, the number of reclosers operating only as a sectionalising switch (SECC) and not as a recloser or even as a circuit breaker, has also been growing. This "sacrifice" occurs mainly in cases where there is no coordination for phase overcurrent (ANSI functions 50/51), once for the earth/ground faults it can be assumed that there will always be coordination (ANSI 50N/51N functions). This resource is satisfactory for simple configurations of the RL-SECC type, however, it has major drawbacks when it involves two or more consecutive (or serial) SECCs in the feeder. Considering this scenario and the sophistication of the current protection relays used in the control cubicles of the reclosers, this work proposes a solution to the coordination and selectivity problem by making use of the logic programming resources in the relays, transforming the recloser into a hybrid device. This way, it operates as RL or SECC depending on the type of short circuit. The hybrid recloser, in addition to operating as a dual behavior device (RL / SECC), optimizing the use of this asset in the network, does not require any change in the device protection setting upstream (recloser or circuit breaker), nor does it depend on communication. In addition, it allows the automatic self-healing of healthy stretches, in line with safety practices (it does not increase the number of reclosing (ANSI function 79) of the upstream devices, it can be activated and deactivated locally or remotely, etc.), moreover being a concept not oriented to a specific recloser manufacturer. It is hoped, with this work, to bring a new perspective to the area of study of protection of electric power utilities companies and significant contribution with new practices of protection settings and the operation of reclosers in DNs.
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8
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ALDRIN BEZERRA DIAS
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PROJECT OF IMPLANTATION OF FLEXIBLE PHOTOVOLTAIC SOLAR CELLS IN FIBROCIMENT TILES
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Advisor : RICARDO FERREIRA PINHEIRO
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COMMITTEE MEMBERS :
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RICARDO FERREIRA PINHEIRO
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JOSE LUIZ DA SILVA JUNIOR
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GABRIEL IVAN MEDINA TAPIA
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NEILTON FIDELIS DA SILVA
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Data: Jul 31, 2018
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Show Abstract
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In view of the growing dependence on the use of electricity, and in compliance with national resolutions regulating
micro and small-scale installations from renewable sources, especially since the roof is an essential element of a
building, which guarantees the right Of housing - fundamental right enshrined in the Federal Constitution of 1988
- providing human beings physical and emotional security necessary for survival, this work proposes a prototype
assembly with elements already used in photovoltaic modules of mono and polycrystalline silicon to analyze the
performance of cells Flexible photovoltaic solar cells of the second generation in fiber cement roofing tiles,
for electric power generation. The fiber cement tiles cover 49% of the buildings in Brazil, being the cost an attractive
factor for their use. Flexible photovoltaic solar cells, in turn, also present themselves at low cost due to
manufacturing techniques. Thus, after assembly, tests and project design, which will define, among other factors,
the appropriate treatment of typical technical issues, such as the inclination to obtain maximum power, proposing
solutions of connections and electrical and mechanical protections, it is intended To verify the level of electricity
cost and to complete the viability analysis of the whole process for the proposed prototype, aiming to present a
sustainable and energy efficient product, being able to be a solution of generation of electricity at a low cost in
government housing programs for the population Of low income - for example "My House My Life", agricultural
sheds, among several other applications.
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