Algoritmo genético especializado aplicado ao planejamento da expansão de sistemas de distribuição de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Método primal-dual previsor-corretor de pontos interiores e exteriores com estratégias de correção de inércia e suavização hiperbólica aplicado ao problema de despacho econômico com ponto de carregamento de válvula e representação da transmissão

Pós-graduação em Engenharia Elétrica - FEB

Heurística especializada aplicada na alocação ótima de bancos de capacitores em sistemas de distribuição radial

Pós-graduação em Engenharia Elétrica - FEIS

Alocação ótima de chaves de interconexão nas redes de distribuição de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Aplicação de técnicas metaheurísticas para resolver o problema de coordenação de carregamento de veículos elétricos em sistemas de distribuição

Pós-graduação em Engenharia Elétrica - FEIS

Propostas de modelagem matemática para o problema de restauração de sistemas de distribuição de energia elétrica radiais

Pós-graduação em Engenharia Elétrica - FEIS

Reconfiguração de sistemas de distribuição operando em vários níveis de demanda através de uma meta-heurística de busca em vizinhança variável

Pós-graduação em Engenharia Elétrica - FEIS

Artificial immune networks Copt-aiNet and Opt-aiNet applied to the reconfiguration problem of radial electrical distribution systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reconfiguration of radial electric power distribution system via a scatter search algorithm

In this paper, to solve the reconfiguration problem of radial distribution systems a scatter search, which is a metaheuristic-based algorithm, is proposed. In the codification process of this algorithm a structure called node-depth representation is used. It then, via the operators and from the electrical power system point of view, results finding only radial topologies. In order to show the effectiveness, usefulness, and the efficiency of the proposed method, a commonly used test system, 135-bus, and a practical system, a part of Sao Paulo state's distribution network, 7052 bus, are conducted. Results confirm the efficiency of the proposed algorithm that can find high quality solutions satisfying all the physical and operational constraints of the problem.

Mesopelagic fish collected during Maria S. Merian cruise MSM26, spring 2013

Mesopelagic fish were collected using a 1 m**2 Double-MOCNESS (Multiple Opening and Closing Net and Environmental Sensing System) and 4.5 m**2 IKMT (Isaacs-Kidd midwater trawl). The main portion of the IKMT was 20 mm knotted nylon, and the tail bag was 3 mm knotless nylon. Oblique IKMT tows were made to a maximum depth of 500 m at a tow speed of 3.5 knots. The original cruise plan intended for nighttime IKMT tows, but tow times varied due to operational constraints. The MOCNESS was equipped with 20 nets of 333 µm mesh size; 10 nets per side. The towing speed was 2 knots. Samples were collected to a maximum depth of 1250 m. The first oblique nets sampled from the surface to the max depth, and the other nets sampled depth stratified bins of the water column. MOCNESS hauls were performed during day and night to investigate diel vertical migrations. Mesoplelagic fish were processed on board. All fish were picked from all IKMT nets, most oblique MOCNESS nets, and the left side nets of the depth stratified MOCNESS samples. The Depth stratified nets from the right side of the MOCNESS frame were preserved in 5 % formalin for future quantitative analyses of the nekton. Fish were identified to the lowest possible taxa using Whitehead et al. (1984) and Fahay (2007). Standard length of each fish was measured to the nearest 0.1 mm using a digital caliper. Measured and identified fish were frozen in an -80 °C freezer, and shipped to the University of Hamburg at the end of the cruise.

Abundance mesopelagic fish collected during Maria S. Merian cruise MSM26, spring 2013

Mesopelagic fish were collected using a 1 m**2 Double-MOCNESS (Multiple Opening and Closing Net and Environmental Sensing System) and 4.5 m**2 IKMT (Isaacs-Kidd midwater trawl). The main portion of the IKMT was 20 mm knotted nylon, and the tail bag was 3 mm knotless nylon. Oblique IKMT tows were made to a maximum depth of 500 m at a tow speed of 3.5 knots. The original cruise plan intended for nighttime IKMT tows, but tow times varied due to operational constraints. The MOCNESS was equipped with 20 nets of 333 µm mesh size; 10 nets per side. The towing speed was 2 knots. Samples were collected to a maximum depth of 1250 m. The first oblique nets sampled from the surface to the max depth, and the other nets sampled depth stratified bins of the water column. MOCNESS hauls were performed during day and night to investigate diel vertical migrations. Mesoplelagic fish were processed on board. All fish were picked from all IKMT nets, most oblique MOCNESS nets, and the left side nets of the depth stratified MOCNESS samples. The Depth stratified nets from the right side of the MOCNESS frame were preserved in 5 % formalin for future quantitative analyses of the nekton. Fish were identified to the lowest possible taxa using Whitehead et al. (1984) and Fahay (2007). Standard length of each fish was measured to the nearest 0.1 mm using a digital caliper. Measured and identified fish were frozen in an -80 °C freezer, and shipped to the University of Hamburg at the end of the cruise.

Frozen orbits for scientific missions using rotating tethers

We derive a semi-analytic formulation that permits to study the long-term dynamics of fast-rotating inert tethers around planetary satellites. Since space tethers are extensive bodies they generate non-keplerian gravitational forces which depend solely on their mass geometry and attitude, that can be exploited for controlling science orbits. We conclude that rotating tethers modify the geometry of frozen orbits, allowing for lower eccentricity frozen orbits for a wide range of orbital inclination, where the length of the tether becomes a new parameter that the mission analyst may use to shape frozen orbits to tighter operational constraints.

El papel de la hidroelectricidad en el contexto de las energías renovables en España

En el artículo se discute el papel de la energía hidroeléctrica en el marco del sistema eléctrico español, donde existe una elevada penetración de energías no gestionables con una tendencia clara a aumentar en los próximos años. El desarrollo de nuevas centrales hidroeléctricas se basará probablemente en centrales reversibles. La energía hidroeléctrica es una tecnología madura y eficiente para el almacenamiento de energía a gran escala y contribuye por tanto de manera decisiva a la integración de fuentes renovables no gestionables. Los beneficios obtenidos con la operación punta-valle pueden ser insuficientes para compensar el coste de una nueva central. Sin embargo, los ingresos obtenidos pueden incrementarse sustancialmente mediante su participación en los servicios de ajuste del sistema. Ello requeriría un diseño apropiado del mercado eléctrico. La contribución de las centrales hidráulicas reversibles al balance producción-consumo puede extenderse a las horas valle utilizando, bien bombeo en velocidad variable o bien una configuración de cortocircuito hidráulico. La necesidad de mitigar los efectos hidrológicos aguas abajo de las centrales hidroeléctricas puede introducir algunas restricciones en la operación que limitaría de algún modo los servicios descritos más arriba. Sin embargo, cabe esperar que los efectos ambientales provocados por las centrales hidráulicas reversibles sean significativamente menores. In this paper the role of hydropower in electric power systems is discussed, in the framework of the Spanish system, where a high penetration of intermittent power sources exists, showing a clear trend to increase in next years. The development of new hydro power facilities will be likely based on pumped storage hydro power plants. Hydropower is a mature and efficient technology for large-scale energy storage and therefore represents a key contribution for the integration of intermittent power sources, such as wind or photovoltaic. The benefits obtained from load shifting may be insufficient to compensate the costs of a new plant. However, the obtained revenues can significantly increase through its contribution to providing ancillary services. This would require an appropriate design of the electricity market. The contribution of pumped storage hydro power plants to balancing services can be extended to off-peak hours, using either variable speed pumping or the hydraulic shortcircuit configuration. The need to mitigate hydrological effects downstream of hydro plants may introduce some operational constraints which could limit to some extent the services described above. However environmental effects caused by pumped storage hydro power plants are expected to be significantly smaller.

Desenvolvimento de algoritmo de controle de tração para regeneração de energia metroviária - ACTREM: melhoria da eficiência energética de sistemas de tração metroviária.

Esta tese propõe um modelo de regeneração de energia metroviária, baseado no controle de paradas e partidas do trem ao longo de sua viagem, com o aproveitamento da energia proveniente da frenagem regenerativa no sistema de tração. O objetivo é otimizar o consumo de energia, promover maior eficiência, na perspectiva de uma gestão sustentável. Aplicando o Algoritmo Genético (GA) para obter a melhor configuração de tráfego dos trens, a pesquisa desenvolve e testa o Algoritmo de Controle de Tração para Regeneração de Energia Metroviária (ACTREM), usando a Linguagem de programação C++. Para analisar o desempenho do algoritmo de controle ACTREM no aumento da eficiência energética, foram realizadas quinze simulações da aplicação do ACTREM na linha 4 - Amarela do metrô da cidade de São Paulo. Essas simulações demonstraram a eficiência do ACTREM para gerar, automaticamente, os diagramas horários otimizados para uma economia de energia nos sistemas metroviários, levando em consideração as restrições operacionais do sistema, como capacidade máxima de cada trem, tempo total de espera, tempo total de viagem e intervalo entre trens. Os resultados mostram que o algoritmo proposto pode economizar 9,5% da energia e não provocar impactos relevantes na capacidade de transporte de passageiros do sistema. Ainda sugerem possíveis continuidades de estudos.

Mathematical Optimization for the Train Timetabling Problem

AMS Subj. Classification: 90C57; 90C10;