Development of a DC-DC converter for DC bus voltage control of series connected device

The purpose of this work is to study voltage control and energy balance of a split DC bus topology within a power electronics equipment connected to the AC mains, such as UPS systems, wind power generators, active filters and FACTS devices. A typical configuration in such equipment has two mains connected converters sharing a common DC bus, one series connected and the other parallel connected. The DC bus is usually composed by a battery or a capacitor bank. In the proposed topology, the DC bus is divided in two sides, interconnected with a buck-boost converter, which controls power flow and DC voltage on both sides. © 2009 IEEE.

Remote Sensing Detection of atmospheric pollutants using Lidar, Sodar and correlation with air quality data in an industrial area

Optical remote sensing techniques have obvious advantages for monitoring gas and aerosol emissions, since they enable the operation over large distances, far from hostile environments, and fast processing of the measured signal. In this study two remote sensing devices, namely a Lidar (Light Detection and Ranging) for monitoring the vertical profile of backscattered light intensity, and a Sodar (Acoustic Radar, Sound Detection and Ranging) for monitoring the vertical profile of the wind vector were operated during specific periods. The acquired data were processed and compared with data of air quality obtained from ground level monitoring stations, in order to verify the possibility of using the remote sensing techniques to monitor industrial emissions. The campaigns were carried out in the area of the Environmental Research Center (Cepema) of the University of São Paulo, in the city of Cubatão, Brazil, a large industrial site, where numerous different industries are located, including an oil refinery, a steel plant, as well as fertilizer, cement and chemical/petrochemical plants. The local environmental problems caused by the industrial activities are aggravated by the climate and topography of the site, unfavorable to pollutant dispersion. Results of a campaign are presented for a 24- hour period, showing data of a Lidar, an air quality monitoring station and a Sodar. © 2011 SPIE.

Interfaces culturais de Mallarmé à World Wide Web

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mercado de carbono: um estudo comparado entre Brasil, China e Índia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de um modelo fuzzy para otimização da energia gerada por um sistema híbrido (solar-fotovoltaico e eólico)

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Renewable energy sources in Latin America and the Caribbean: situation and policy proposals

Includes bibliography

Nova metodologia para análise e síntese de sistemas de aterramento complexos utilizando o método lN-FDTD, computação paralela automática e redes neurais artificiais

Neste trabalho, o método FDTD em coordenadas gerais (LN-FDTD) foi implementado para a análise de estruturas de aterramento com geometrias coincidentes ou não com o sistema de coordenadas cartesiano. O método soluciona as equações de Maxwell no domínio do tempo, permitindo a obtenção de dados a respeito da resposta transitória e de regime estacionário de estruturas diversas de aterramento. Uma nova formulação para a técnica de truncagem UPML em coordenadas gerais, para meios condutivos, foi desenvolvida e implementada para viabilizar a análise dos problemas (LN-UPML). Uma nova metodologia baseada em duas redes neurais artificiais é apresentada para a deteccão de defeitos em malhas de terra. O software FDTD em coordenadas gerais foi testado e validado para vários casos. Uma interface gráfica para usuários, chamada LANE SAGS, foi desenvolvida para simplificar o uso e automatizar o processamento dos dados.

Brasil e Alemanha: modelos comparativos para as energias renováveis

Pós-graduação em Engenharia Mecânica - FEG

Viabilidade de turbinas eólicas de pequeno porte no Brasil

Facing a global scenario where oil is scarce and the emission of CO2 in the atmosphere is a world concern, the search for new methods of energy production becomes the focus of all countries. Based on these assumptions, the wind power gains highlight and happen to be the most exploited around the world, since this does not produce toxic waste, since it uses the wind, no raw material shortage and its cost and efficiency are increasingly attractive. Taking advantage of the geographical features of Brazil, coastal and territorial extension, this study aims to analyze the feasibility of using wind turbines widely used in Germany, one of the countries with the highest production of energy through wind, in Brazil. In order to increase the energy production without causing more environmental impacts, geographical analyses will be made, and to determine the features and costs of production of this type of energy generation, and at the end of this dissertation, will finish for one of the turbines, Montana, is it feasible to install, however due to the Government's little incentive return is not very expressive. With respect to the turbine Passaat, this is infeasible to install under current conditions

Análise comparativa entre Brasil e Alemanha sobre autoprodução de energia elétrica residencial

The energy crisis has affected many countries. With the growing warning with the emission in the atmosphere and the lack of resources, the seek for sustainable sources for energy genaration have become even bigger. Some Countries, as Germany, started first in this journey, creating an incentive program to self-generation with renewable sources (wind, photovoltaics, biomass, etc.), giving priority for smaller plants. In Germany the program called EEG started in 2004. In Brazil, since the beggining of 2012, the self-generators did not know how they could be beneficted for self-generation, and self-generation didn't become commun in the country. However, with NR 482, of April 17th, 2012, the parameters were defined, and the self-generator could have a guideline. Therewith, studyies can be redirected for a better knowlegde of the conditions the self-generator will be sujected, in addition to Germany's case as reference to compare with Brazil's case. In this paper these studies are made, focused in wind power (wind turbines) and photovoltaic panels

Aplicação do AHP em um caso de escolha dos modais de transporte para a movimentação das partes de um aerogerador

Wind power is a type of energy that is still not too explored in Brazil and, because of the lack of experience in projects of this size, there are still some problems during the stages of planning and execution of wind farms projects. One of these problems is related with the parts’ transportation logistics, since these parts are difficult to transport, because of their length, weight or shape. Furthermore, another aggravating factor is the lack of options regarding to the transportation modals that are available to do the route between the manufacture place and the project site. To help in the decision-making process about the ideal transportation configuration, aiming to reduce the dependence of the logistics’ coordinator, it was chosen to use he AHP method to compare some criteria that have influence in the modal’s choice process. The criteria, determined by the members of the company’s logistics’ department, are: transportation costs, transportation time and the risk of causing damages to the cargo. The results shown by this model, using theoretical background, that standardize the processes related to the modal’s choice

Estudo da produção de hidrogênio eletrolítico a partir de fontes eólica, solar e hidrelétrica

Introduces technical, economic and environmentally competitive solutions in the energy market is a great challenge for society. This work examines each of these aspects considering the production of electrolytic hydrogen with energy from wind power, solar and hydropower, in order to ensure an overview of this energy carrier. Initially, an assessment of the technical aspects is made addressing existing electrolysers technologies, its main characteristics and differences. The geographical distribution of wind, solar and hydroelectric potential in Brazil is also mapped, and a configuration scheme of a hydrogen production system is discussed. Subsequently, the economic analysis calculates the cost of investment in the alkaline electrolyser of 60 Nm³ / h, similar to the Brazilian bus powered by hydrogen project, coordinated by EMTU. Since the main input of electrolysis is electricity, is analyzed the latest energy auctions of each primary source and it is calculated the cost of production of the wind, solar and hydropower hydrogen. Postponed to this, are investigated the intrinsic environmental impacts of electricity generation process, proposing a readjustment of an indicator of ecological efficiency for the production of hydrogen. Finally, the work discusses the concept of externalities and demonstrates how the incorporation of external costs can leverage the hydrogen economy. In short, it is evident that the wind and hydroelectric hydrogens are more promising compared to solar hydrogen, whether in the economic aspect, because it achieved lower costs, whether in the environmental aspect, because it reached the highest ecological efficiency

Viabilidade da geração de eletricidade a partir de fonte eólica on-shore: dificuldades e vantagens de expansão na matriz elétrica brasileira

The renewable energy sources presents an important role on the world's current context, its growing is essentially connected to the environmental issues and the energetic security, guided by the search for alternatives of energy. Among the alternative energy sources, the wind energy shows great importance in the brazilian territory, it has a great potential still unexplored and constant growth in the national electric matrix. The specific factor of generation, the conjuncture and the incentive politics influence on the expansion of wind energy in Brazil. Thus, the brazilian wind sector shows features which can be evaluated enable its developing. Keeping that in mind, the present work aims identify which are the advantages and the difficulties for the expansion of this energy source in the brazilian electric matrix. For that, the work studies the different parameters: features of electric generation of the different energy sources, incentive politics, generation costs, CO2 emission, evolution of wind energy in Brazil, the brazilian wind potential, and the regime of complementarily hydro-wind

Melhoria nas forças restaurativas do equilíbrio do gerador de indução duplamente alimentado por meio de controle da tensão interna

Pós-graduação em Engenharia Elétrica - FEIS

A method using artificial neural networks to morphologically assess mouse blastocyst quality

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)