Prospecção tecnológica para geração de energia eólica

The acceleration of technological change and the process of globalization has intensified competition and the need for new products (goods and services), resulting in growing concern for organizations in the development of technological, economic and social advances. This work presents an overview of the development of wind energy-related technologies and design trends. To conduct this research, it is (i) a literature review on technological innovation, technological forecasting methods and fundamentals of wind power; (ii) the analysis of patents, with the current technology landscape studied by means of finding information in patent databases; and (iii) the preparation of the map of technological development and construction of wind turbines of the future trend information from the literature and news from the sector studied. Step (ii) allowed the study of 25 644 patents between the years 2003-2012, in which the US and China lead the ranking of depositors and the American company General Electric and the Japanese Mitsubishi stand as the largest holder of wind technology. Step (iii) analyzed and identified that most of the innovations presented in the technological evolution of wind power are incremental product innovations to market. The proposed future trends shows that the future wind turbines tend to have a horizontal synchronous shaft, which with the highest diameter of 194m and 164m rotor nacelle top, the top having 7,5MW generation. The materials used for the blades are new materials with characteristics of low density and high strength. The towers are trend with hybrid materials, uniting the steel to the concrete. This work tries to cover the existing gap in the gym on the use of technological forecasting techniques for the wind energy industry, through the recognition that utilize the patent analysis, analysis of scientific articles and stories of the area, provide knowledge about the industry and influencing the quality of investment decisions in R & D and hence improves the efficiency and effectiveness of wind power generation

A geração de 27 e o barroco: la mirada exuberante

From the context of the degree‘s creation of Spanish literature and language‘s course, at UFRN, came the motivation to make this research, that presents a literary study of a poet‘s group known as Generación del 27, that came in to light at Spain, on 1920. A lot of aspects of this study are themes of many others disciplines, of this degree (Spanish Literature II, IberianAmerican Literature, Spanish Culture, Translation in Spanish Language). This work will also serve as inspiration to new reflections and proposes of translations, as bridges between the language that goes and the other that comes. It is the Translation as comprehension‘s negotiation between languages, it is the decir casi lo mismo, here in poem‘s form (ECO, 2007), in the attempt to conclude new learning, that will be shared with undergraduate and graduate students, being at teaching area, extension or new researches. To contextualize this generation‘s studies, were elected the anthologies organized by Gerardo Diego, called Poesía Española (Antologías), published on 2007, by Ediciones Cátedras, and the Antología Comentada de La Generación del 27, wrote by Víctor García de La Concha, published on 2006, by Editorial Espasa Calpe. The research took Generacion Del 27 as their object of research and - from many others critical reading about the poetry made by those young poets, their creative vocation of aesthetics and vanguard – wanted to understand the context of literary‘s creation of those poets del 27. We form our foundation with contributions by Antonio Maravall (2009), Eugenio D‘ors (s.d) Severo Sarduy (1999), Lezama Lima (2011), Alfonso Reyes (1958) e Deleuze (2005) among others that brought the comprehension of the baroque‘s language, giving emphasis to pluridirectional movement, deconstructing it‘s linearity, creating others new forms, as returns, circles, spirals favoring encounters, detachment or equal points of departure and arrivals. In this way, the poets del 27 approached the baroque of six hundred on a re-reading, and made of the third centenary‘s celebration of the Góngora‘s a Mirada exuberante death, to the return of baroque‘s spirit. Alfonso Reyes e Rubén Darío said that real lights highlighted the paths of this poets generation: The light that desdobra scintillates on García Lorca, Jorge Gullén, Dámaso Alonso, Gerardo Diego and the bullfighter Ignacio Sánchez Mejías, poets that expressed tributes in big style to Soledades author, at Madrid‘s Caffe and all Spain.

Controle em modo dual adaptativo robusto aplicado a um sistema de geração de energia elétrica

Synchronous machines, widely used in energy generation systems, require constant voltage and frequency to obtain good quality of energy. However, for large load variati- ons, it is difficult to maintain outputs on nominal values due to parametric uncertainties, nonlinearities and coupling among variables. Then, we propose to apply the Dual Mode Adaptive Robust Controller (DMARC) in the field flux control loop, replacing the tradi- tional PI controller. The DMARC links a Model Reference Adaptive Controller (MRAC) and a Variable Structure Model Reference Adaptive Controller (VS-MRAC), incorpora- ting transient performance advantages from VS-MRAC and steady state properties from MRAC. Moreover, simulation results are included to corroborate the theoretical studies.

Proteção em sistemas elétricos com geração distribuída utilizando a transformada wavelet

A typical electrical power system is characterized by centr alization of power gene- ration. However, with the restructuring of the electric sys tem, this topology is changing with the insertion of generators in parallel with the distri bution system (distributed gene- ration) that provides several benefits to be located near to e nergy consumers. Therefore, the integration of distributed generators, especially fro m renewable sources in the Brazi- lian system has been common every year. However, this new sys tem topology may result in new challenges in the field of the power system control, ope ration, and protection. One of the main problems related to the distributed generati on is the islanding formation, witch can result in safety risk to the people and to the power g rid. Among the several islanding protection techniques, passive techniques have low implementation cost and simplicity, requiring only voltage and current measuremen ts to detect system problems. This paper proposes a protection system based on the wavelet transform with overcur- rent and under/overvoltage functions as well as infomation of fault-induced transients in order to provide a fast detection and identification of fault s in the system. The propo- sed protection scheme was evaluated through simulation and experimental studies, with performance similar to the overcurrent and under/overvolt age conventional methods, but with the additional detection of the exact moment of the fault.

Geração de padrão de marcha adaptável para uma órtese ativa de membros inferiores

Atualmente com o crescente aumento de dispositivos robóticos destinados para aplicação na área de mobilidade de pessoas que sofreram algum tipo de lesão medular, se faz necessário desenvolver novas ferramentas para tornar tais equipamentos mais adaptáveis, seguros e autônomos. Para que as órteses robóticas que auxiliam na locomoção de pessoas paraplégicas possam desempenhar sua função, estas devem ser capazes de reproduzir os movimentos perdidos com o máximo de fidelidade e segurança em ambientes que eventualmente possam conter obstáculos de diferentes tipos como buracos, escadas e calçadas. As órteses robóticas para membros inferiores têm a capacidade de caminhar, subir e descer degraus, todavia, esses movimentos, na maioria das vezes, não se adaptam ao ambiente, sendo assim, para uma órtese robótica que foi projetada para subir um degrau com uma determinada altura ao se deparar com um degrau maior provavelmente não conseguirá realizar essa tarefa com a mesma segurança. Para solucionar esse e outros problemas, esse trabalho apresenta um Sistema de Auxílio à Locomoção (SAL) dotado de um planejador de passos e um gerador de referências angulares com características antropomórficas para a órtese robótica Ortholeg. O SAL utiliza dados antropométricos do usuário para gerar um padrão de marcha personalizado, dessa forma, a órtese em questão é capaz de adaptar o tamanho do passo para não colidir com obstáculos presentes no ambiente e transpor buracos com diversos tamanhos, subir e descer escadas e calçadas com diferentes valores de altura e comprimento. Para desenvolver o sistema de auxílio à locomoção foram adaptadas técnicas de planejamento de caminho, usadas a princípio em robôs bípedes. São apresentados vários experimentos que mostram a órtese Ortholeg realizando alguns movimentos com características antropomórficas para diferentes distâncias de caminhada e três tipos de obstáculos: degrau, buraco e calçada. A autonomia adquirida com a utilização do sistema de planejamento apresentado facilita a utilização de órteses robóticas como também garante uma maior segurança ao usuário.

Contribuições para estratégia de controle aplicada à geração fotovoltaica interconectada à rede elétrica

Generation systems, using renewable sources, are becoming increasingly popular due to the need for increased use of electricity. Currently, renewables sources have a role to cooperate with conventional generation, due to the system limitation in delivering the required power, the need for reduction of unwanted effects from sources that use fossil fuels (pollution) and the difficulty of building new transmission and/or distribution lines. This cooperation takes place through distributed generation. Therefore, this work proposes a control strategy for the interconnection of a PV (Photovoltaic) system generation distributed with a three-phase power grid through a connection filter the type LCL. The compensation of power quality at point of common coupling (PCC) is performed ensuring that the mains supply or consume only active power and that his currents have low distorcion. Unlike traditional techniques which require schemes for harmonic detection, the technique performs the harmonic compensation without the use of this schemes, controlling the output currents of the system in an indirect way. So that there is effective control of the DC (Direct Current) bus voltage is used the robust controller mode dual DSMPI (Dual-Sliding Mode-Proportional Integral), that behaves as a sliding mode controller SM-PI (Sliding Mode-Proportional Integral) during the transition and like a conventional PI (Proportional Integral) in the steady-state. For control of current is used to repetitive control strategy, which are used double sequence controllers (DSC) tuned to the fundamental component, the fifth and seventh harmonic. The output phase current are aligned with the phase angle of the utility voltage vector obtained from the use of a SRF-PLL (Synchronous Reference Frame Phase-Locked-Loop). In order to obtain the maximum power from the PV array is used a MPPT (Maximum Power Point Tracking) algorithm without the need for adding sensors. Experimental results are presented to demonstrate the effectiveness of the proposed control system.

Anisotropia magnética em nanofilmes com assimetria cristalográfica

This Thesis comprises a theoretical study about the influence of the magnetocrystalline anisotropy on the static and dynamic magnetic properties of nanofilms: monolayers and trilayers coupled through the bilinear and biquadratic exchange fields, for situations in which the systems are grown in unusual [hkl] asymmetric directions. Using a theory based on a realistic phenomenological model for description of nanometric systems, we consider the total free magnetic energy including the Zeeman interaction, cubic and uniaxial anisotropies, demagnetizing and surface anysotropy energies, as well as the exchange terms. Numerical calculations are conducted by minimizing the total magnetic energy from the determination of equilibrium static configurations. We consider experimental parameters found in the literature to illustrate our results for Fe/Cr/Fe trilayer systems. In particular, a total of six different magnetic scenarios are analyzed for three regimens of exchange fields and the [211] and [321] asymmetric growth directions. After numerically minimize the total energy, we use the equilibrium configurations to calculate magnetization and magnetoresistance curves with the respective magnetic phases and corresponding critical fields. These results are also used to establish the boundary for occurrence of saturated states. Within the context of the spin waves, we solve the equation of motion for these systems in order to find the respective associated dispersion relations. The results show similar magnetization and magnetoresistance curves for both [211] and [321] growth scenarios, including an equivalent magnetic transition behavior. However, the combination of those peculiar symmetries and influence of the exchange energies results in attractive properties, including the generation of magnetic states as a function of the asymmetric degree imposed in the [hkl] growth orientations. There is also an increasing incompatibility between the values of saturation fields of magnetization and magnetoresistance for the cases in which a magnetic field acts along intermediate cubic anisotropic axes, particularly in the situations where the bilinear and biquadratic exchange fields are comparable. The dispersion relations and static results are consistent, the corresponding magnetic states are also present in both acoustic and optical modes. Furthermore, Goldstone excitations are also observed for that particular cases of a magnetic field acting in the intermediate axes, an effect related to transitions of second order and to the spontaneous symmetry breaking imposed by the combination of the biquadratic energy with the cubic and uniaxial anisotropies.

Utilização da transformada de wavelet para detecção de variações anormais de tensão em sistemas elétricos com geração distribuída

The increasing demand in electricity and decrease forecast, increasingly, of fossil fuel reserves, as well as increasing environmental concern in the use of these have generated a concern about the quality of electricity generation, making it well welcome new investments in generation through alternative, clean and renewable sources. Distributed generation is one of the main solutions for the independent and selfsufficient generating systems, such as the sugarcane industry. This sector has grown considerably, contributing expressively in the production of electricity to the distribution networks. Faced with this situation, one of the main objectives of this study is to propose the implementation of an algorithm to detect islanding disturbances in the electrical system, characterized by situations of under- or overvoltage. The algorithm should also commonly quantize the time that the system was operating in these conditions, to check the possible consequences that will be caused in the electric power system. In order to achieve this it used the technique of wavelet multiresolution analysis (AMR) for detecting the generated disorders. The data obtained can be processed so as to be used for a possible predictive maintenance in the protection equipment of electrical network, since they are prone to damage on prolonged operation under abnormal conditions of frequency and voltage.

Uma estratégia para otimizar a geração de arranjos em subestações virtuais de energia elétrica

The Virtual Reality techniques applied in Electricity Environments provide a new supervisory control paradigm. The fact of existing a virtual environment (VE), geometrically similar to a real substation, reduces the difference of mental models built by field operators compared with those built by system center operation improving the communication. Beside this, those systems can be used as visualization interfaces for electricity system simulators, training systems for professors and undergraduate students, field operators and maintenance professionals. However, the development process of these systems is quite complex, combining several activities such as implementation, 3D modeling, virtual sceneries construction, usability assessment and management project techniques. In this context, this work present a GUI strategy to build field arrangements based on scene graphs, to reduce time in Virtual Electricity Substations Arrangement development. Through this, mistakes during the VE building can be avoided making this process more reliable. As an concept proof, all toolkits developed in this work were applied in the virtualization of the substations from a Brazilian power concessionary named CEMIG.

Uma metodologia para geração otimizada de ambientes virtuais baseados em usinas hidrelétricas

Based on the possibility of real-time interaction with three-dimensional environments through an advanced interface, Virtual Reality consist in the main technology of this work, used in the design of virtual environments based on real Hydroelectric Plants. Previous to the process of deploying a Virtual Reality System for operation, three-dimensional modeling and interactive scenes settings are very importante steps. However, due to its magnitude and complexity, power plants virtual environments generation, currently, presents high computing cost. This work aims to present a methodology to optimize the production process of virtual environments associated with real hydroelectric power plants. In partnership with electric utility CEMIG, several HPPs were used in the scope of this work. During the modeling of each one of them, the techiniques within the methodologie were addressed. After the evaluation of the computional techniques presented here, it was possible to confirm a reduction in the time required to deliver each hydroelectrical complex. Thus, this work presents the current scenario about development of virtual hydroelectric power plants and discusses the proposed methodology that seeks to optimize this process in the electricity generation sector.

A geração Y brasileira e o seu comprometimento organizacional em empresas de conhecimento intensivo.

O comprometimento organizacional é o estado psicológico que explica o elo entre o indivíduo e a organização, refletindo a escolha dele em nela permanecer (Allen, 1996; Meyer, 2000), e a geração Y é um tema que vem ganhando destaque nos últimos anos. A partir destes dois conteúdos, surgiu esta pesquisa que tem como objetivo identificar e analisar as bases de comprometimento organizacional da geração Y em empresas de conhecimento intensivo. O referencial teórico contempla as definições de gerações, a caracterização da geração Y e a contextualização de comprometimento organizacional, sob o enfoque das abordagens afetiva, instrumental e normativa. Trata-se de uma pesquisa quantitativa, classificando-se como descritiva. O resultado obtido, na amostra pesquisada em empresas de consultorias, mostrou a «obrigação pelo desempenho» como a base de comprometimento organizacional mais relevante para a geração Y. Embora apresentem um baixo comprometimento em permanecer na organização, este resultado revela que esta geração está preocupada em desempenhar um bom trabalho, buscando atingir os objetivos organizacionais, e atingir resultados relevantes para a organização.