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URI permanente para esta coleçãohttps://rigalileo.itegam.org.br/handle/123456789/175

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MODELO MATEMÁTICO PARA OTIMIZAÇÃO MULTIOBJETIVO DO DESPACHO ECONÔMICO AMBIENTAL DE USINAS TÉRMICAS USANDO O NSGA-II
(Universidade Federal do Pará, 2017) MORAES, Nadime Mustafa; BEZERRA, Ubiratan Holanda
One of the priority tasks for thermoelectric plants is to supply the requested energy demand, ensuring the lowest possible cost. This task is especially important in the Northern Region of Brazil, particularly in the Manaus Industrial Hub (PIM), where much of the energy is supplied by Thermoelectric Power Plants (UTE). The selection of generators and their work regime is known as Economic Dispatch (DE). However, global concern about pollution caused by fossil fuels has made it essential to incorporate not only cost reduction but also the limitation of pollutant emissions in UTE operations. Thus, Environmental Economic Dispatch (DEA) emerges, aiming to simultaneously reduce costs and emissions. This thesis proposes an innovative mathematical model for DEA, using the NSGA-II evolutionary algorithm with two objective functions: fuel cost and amount of emissions. The model also introduces the Emissions Index, a new function to evaluate environmental contamination, considering the influence of the most harmful pollutants. The model was applied to engines of two UTEs in the city of Manaus, showing satisfactory results. The methodology proved robust when validated in two case studies: a set of ten thermal generating units and the IEEE 118-bus system.
OTIMIZAÇÃO MULTIOBJETIVO DA COMPENSAÇÃO DE POTÊNCIA REATIVA EM REDES DE DISTRIBUIÇÃO CONSIDERANDO RESTRIÇÕES DE DISTORÇÃO HARMÔNICA
(Universidade Federal do Pará, 2014) AZEVEDO, Manoel Socorro Santos; BEZERRA, Ubiratan Holanda
The correct location of capacitor banks in electric power distribution networks aims to compensate for excess reactive power flow through transmission lines, reducing operational costs by decreasing energy losses and increasing active power transmission capacity while ensuring appropriate voltage and power factor levels. The proliferation of nonlinear loads has introduced new challenges due to the harmful effects of harmonics on power quality. This thesis develops a computational tool using computational intelligence techniques with genetic algorithms (GA) for multiobjective optimization of reactive power compensation in electric distribution networks, capable of optimally locating and sizing compensation units while achieving economic benefits and complying with Brazilian power quality standards. The approach considers the use of capacitor banks and harmonic filters and applies the NSGA-II algorithm to determine Pareto-optimal solutions. The methodology enables the determination of reactive power compensation considering harmonic presence while maintaining compliance with normative limits on harmonic distortion.
PRÉ-DESPACHO DE CARGA EM USINAS TERMOELÉTRICAS CONSIDERANDO A GESTÃO DA MANUTENÇÃO VIA LÓGICA FUZZY
(Universidade Federal do Pará, 2018) FONSECA JUNIOR, Milton; BEZERRA, Ubiratan Holanda
This thesis presents a new proposal for load pre-dispatch considering the technical conditions of the engines of thermoelectric power plants by combining several maintenance and diagnostic techniques and using computational intelligence based on fuzzy logic. Diagnosis of the technical conditions of the engines is done using lubricant analysis, vibration analysis, and thermography. With this data and statistical analysis it is possible to predict when an engine can fail and consider this in the load pre-dispatch. To increase engine reliability and power supply, a Maintenance Management Program (MMP) was developed using management tools, applying only four TPM (Total Productive Maintenance) pillars and combining them with predictive maintenance and diagnostics, thus allowing the reduction of failures of plant equipment. Some results achieved after the implementation are: reduction of the annual maintenance cost, reduction of corrective maintenance, increase of the MTBF (Mean Time Between Failures), and decrease of MTTR (Mean Time To Repair) in all areas. In addition, the proposed pre-dispatch scheme ensures the demanded power with a high degree of reliability and quality.