Regulador eletromagnético de frequência aplicado no controle de velocidade de geradores eólicos

The constant necessity for new sources of renewable energy is increasingly promoting the increase of investments in this area. Among other sources, the wind power has been becoming prominent. It is important to promote the search for the improvement of the technologies involved in the topologies of the wind turbines, seeking for alternatives which enhance the gotten performance, despite the irregularity of the wind speed. This study presents a new system for speed control, in this case applied to the wind turbines - the Electromagnetic Frequency Regulator (EFR). One of the most used devices in some topologies is the mechanical gearboxes which, along with a short service life, often represent sources of noise and defects. The EFR does not need these transmission boxes, representing a technological advancement, using for that an adapted induction machine, in which the stator becomes mobile, supportive to the axis of the turbine. In the topology used in this study, the EFR also allows us to leave out the usage of the eletronic converters to establish the coupling between the generator and the electrical grid. It also the reason why it provides the possibility of obtaining the generation in alternating current, with constant voltage and frequency, where there is no electrical grid. Responsable for the mechanical speed control of the generator, the EFR can be useful in other transmission systems in which the mechanical speed control output is the objective. In addition, the EFR operates through the combination of two inputs, a mechanical and other electrical. It multiplies the possibilities of application because it is able to synergistic coupling between different arrays of energy, and, for such reasons, it enables the various sources of energy involved to be uncoupled from the network, being the synchronous generator responsible for the system connection with the electrical grid, simplifying the control strategies on the power injected in it. Experimental and simulation results are presented through this study, about a wind turbine, validating the proposal related to the efficience in the speed control of the system for different wind conditions.

Estudo de viabilidade técnico-ambiental para implantação de parques eólicos: um estudo de caso em um fragmento do litoral setentrional do Rio Grande do Norte/Brasil

The use of energy from renewable sources is increasingly demanded by society, especially aeolian - whose raw material is wind. Investments in wind power have become significant in Brazil with emphasis on the Northeast and in particular the Rio Grande do Norte state. According to the Empresa de Pesquisa Energética (Energy Research Company) (2012 ) , investments in the state grew significantly since 2002 with a total accumulated power, by 2013, of approximately 3,400 MW . Even with the early experiences of exploitation of wind energy in 2002, it is still considered new and requires further study referring to the likely changes in the environment and society. In this case, it is of growing and urgent importance to deeply study the wind still in the survey phase of the project, ie , at the beginning of decision making on the most feasible to implement these parks site. Given the above, the question is: from a technical and environmental analysis, how to identify viable areas to install Aeolian parks, taking into account the factors of the environmental dynamics that are relevant to minimize the negative results to the environment and the society? Thus, this study conducted a study on technical and environmental feasibility, proposing a methodology of exploration of feasible wind farms in coastal areas. The study area was a fragment of the northern coast of Rio Grande do Norte and its natural landscape units were identified through the environmental characterization of the area, as well as it was elaborated the map of the land cover, restriction homes and urban areas and Permanent Preservation Areas - PPAs. The environmental fragility was subdivided in the fragility of the natural dynamic, mapped through relief, soils and geology of natural units, and the fragility of the ecosystem, originated by the land cover map. In addition to these maps, it was generated the wind resource for an area from a height of 50 and 100 meters. The intersection between the fragility maps, PPAs and Restriction of homes superimposed on maps of wind potential, provided the map of feasibility of Aeolian parks, resulting in the most favorable areas for its facilities in a technical and environmental point of view. From this study, the entrepreneur can evaluate whether or not to proceed with the studies in this area and especially decrease potential conflicts with society.

Aplicação do exame da proporcionalidade diante da implantação de empreendimentos eólicos em áreas de preservação permanente

The setting up of wind power enterprises at Permanent Preservation Areas reflects the obvious conflict and necessary convergence between free market and energy security on the one hand, and the promotion of environmental quality on the other. From the perspective of energy sustainability, and in order to achieve development (in its complex meaning, which converges economic, social, environmental and cultural aspects), the harmonization between free market and an ecologically sustainable environment is required. This work aims to identify the link between the protection system of the Permanent Preservation Areas and the current constitutional order, by analyzing the implementation of wind power enterprises in these protected zones focusing on the proportionality aspects. A legal and purposeful research was developed, from a theoretical method, followed by collecting and analyzing both primary and secondary data. From these data, the law, the legal literature and judicial decisions were cross-examined, under the light of the Constitution and guided by the theory of proportionality and related development imperatives. In this context, the present study identified the link between the principles of the economic order, environment and energy law, finding their basis under the Federal Constitution and development. By reproducing this interrelationship and by means of post-crisis institutional reforms, the guiding objectives of the Brazilian electric sector began to corroborate the precepts of development, although issues regarding its sustainability still persist. The appraisal of proportionality indicates that the Permanent Preservation Areas protection system is insufficient to materialize the right to a healthy quality of life upon the implementation of wind projects at Permanent Preservation Areas, albeit seeking the harmonization between free market and environmental protection.

Aplicação do exame da proporcionalidade diante da implantação de empreendimentos eólicos em áreas de preservação permanente

The setting up of wind power enterprises at Permanent Preservation Areas reflects the obvious conflict and necessary convergence between free market and energy security on the one hand, and the promotion of environmental quality on the other. From the perspective of energy sustainability, and in order to achieve development (in its complex meaning, which converges economic, social, environmental and cultural aspects), the harmonization between free market and an ecologically sustainable environment is required. This work aims to identify the link between the protection system of the Permanent Preservation Areas and the current constitutional order, by analyzing the implementation of wind power enterprises in these protected zones focusing on the proportionality aspects. A legal and purposeful research was developed, from a theoretical method, followed by collecting and analyzing both primary and secondary data. From these data, the law, the legal literature and judicial decisions were cross-examined, under the light of the Constitution and guided by the theory of proportionality and related development imperatives. In this context, the present study identified the link between the principles of the economic order, environment and energy law, finding their basis under the Federal Constitution and development. By reproducing this interrelationship and by means of post-crisis institutional reforms, the guiding objectives of the Brazilian electric sector began to corroborate the precepts of development, although issues regarding its sustainability still persist. The appraisal of proportionality indicates that the Permanent Preservation Areas protection system is insufficient to materialize the right to a healthy quality of life upon the implementation of wind projects at Permanent Preservation Areas, albeit seeking the harmonization between free market and environmental protection.

A Comunicação Interna: a eficácia dos meios de comunicação interna na Caixa Geral de Depósitos

No mundo actual, onde a concorrência cresce e a oferta de produtos aumenta, onde a globalização é palavra de ordem, torna-se essencial pensar a sobrevivência das empresas como estando dependentes da adopção de comportamentos transparentes diante dos públicos, sejam eles de dimensão interna e/ou externa. Reconhecer a importância de controlar os aspectos imprevisíveis a que as empresas estão sujeitas, permite às organizações um maior controlo na previsão dos problemas, como os corrigir antes que estes interfiram no seu sucesso, constituindo assim um ambiente previsível e favorável. A comunicação assume pois um papel primordial na visibilidade positiva de uma empresa. O cliente interno, neste trabalho, será visto como fornecedor de uma rede interna de prestação de serviços, responsável pela agregação de valor aos produtos e serviços oferecidos pela organização. Os clientes internos são também vistos como detentores de um propósito comum responsável tanto pela criação como pela continuidade da organização. Ao longo deste trabalho é descrita e focada a ligação especial que existe entre a comunicação empresarial, a comunicação interna e a estratégia do marketing interno evidenciando a importância destes para as organizações. O objectivo deste estudo é analisar a eficácia dos meios de comunicação interna na Caixa Geral de Depósitos, a partir da realização de 39 inquéritos administrados a colaboradores de uma Agência. Os resultados obtidos com este estudo deram ênfase à eficácia dos meios de comunicação interna utilizados na organização em estudo, concluindo que a comunicação deve ser veiculada de acordo com a utilidade das funções a desempenhar. / In today´s world where competition grows and the supply of products increases, where globalization is a slogan, it is essential to consider the survival of business as being dependent of the adoption of transparent behavior in public, in they internal or external dimensions. Recognizing the importance of controlling the unpredictable aspects that companies are subject, allows organizations greater control in forecast the problems, how to correct them before they interfere with their success, providing a predictable and favorable ambient. Communication assumes an essential role in a positive visibility of a company. The internal customer, this work will be seen as a provider of internal network services, responsible for adding value to products and services offered by the organization. Internal customers are also seen as having a common purpose as much responsible for creating the continuity of the organization. Throughout this work is focused and described the special bond that exists between corporate communication, internal communication and internal marketing strategy, highlighting their importance for the organizations. The aim of this study is to analyze the effectiveness of internal communication in the CGD, from conducting 39 surveys administered to employees of an Agency. The results of this study emphasized the effectiveness of internal communication in the organization used in the study, concluding that the communication should be conveyed according to the usefulness of the tasks.

Teoria de carteiras e a alocação de parques eólicos offshore

The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore

Posibilidades y limitaciones de la garantía de depósitos

Un sistema de garantía de depósitos puede contribuir a la estabilidad financiera, siempre que cuente con fondos adecuados y otros mecanismos de salvaguardia, como un sólido programa de supervisión bancaria. En la fábula de Esopo sobre la liebre y la tortuga, la tortuga aceptó echar una carrera con la liebre. La liebre, mucho más veloz que la tortuga, salió corriendo a toda velocidad en el primer tramo de la carrera, pero después se acostó a dormir una siesta, convencida de que podría adelantar a su contrincante. Cuando despertó, la tortuga, que había avanzado lentamente pero con constancia, se estaba acercando a la meta. La liebre no pudo alcanzar a la tortuga y ésta ganó la carrera. Un sistema de garantía de depósitos eficaz se asemeja más a una tortuga que a una liebre. A primera vista parece que puede establecerse rápidamente y con facilidad un sistema nacional de garantía de depósitos que anuncie una garantía pública para los depósitos de los bancos. Algunos países, a fin de evitar el retiro masivo de depósitos que podría llevar a la quiebra a los bancos en situación sólida y a fin de estabilizar un sistema bancario en dificultades, han intentado crear un sistema de garantía de depósitos de esta forma. Lamentablemente, a menos que el sistema cuente con fondos suficientes para hacer frente a una grave crisis financiera y con un sólido programa de supervisión bancaria, este sistema está destinado al fracaso

Aplicación de lineamientos basados en el informe C.O.S.O. en el área de depósitos de los bancos de El Salvador.

Este trabajo está orientado al fortalecimiento del control interno del área de depósitos de los bancos del país, por medio de la implementación del Informe C.O.S.O. La investigación se desarrolló en el área metropolitana de San Salvador, cubriendo los once bancos existentes en el país. A través de la historia, la banca de El Salvador ha tenido cambios relevantes y ha ejecutado las acciones necesarias para estar a la vanguardia de este mercado. Los avances tecnológicos, la globalización, tratados de libre comercio, entre otros, originan cambios en la economía, estas circunstancias inciden en los bancos nacionales para dar los pasos necesarios y tomar decisiones para mantener el nivel de competitividad. Esto es posible mediante el control interno que se debe ejercer en todas las operaciones del sector financiero, el cual debe garantizar la efectividad de los mismos. En el primer capítulo se presenta una breve reseña histórica de la banca Salvadoreña. Así como, los fundamentos teóricos de la investigación, que resultaron de la revisión de literatura relacionada con el tema. En el segundo capítulo se encuentra el desarrollo de la metodología de investigación utilizada, las herramientas empleadas y determinación de la muestra. El levantamiento de la información fue posible a través de entrevistas y encuestas que se realizaron a empleados responsables del desarrollo del área de depósitos. Los resultados de la investigación fueron analizados y tabulados de manera que exista concordancia con las preguntas relacionadas, después del análisis de las opiniones se presentan los cuadros informativos. Lo anterior permite que en el tercer capítulo se tenga una base que sustente el proceso operativo propuesto, la ampliación en la vigilancia del control interno, con el propósito de garantizar su efectividad. En el cuarto capítulo se presentan los lineamientos propuestos para la aplicación de éste método en el área de depósitos de los Bancos, considerando que el adoptar estas recomendaciones puede ayudar a que el Banco tenga una visión integral sobre el desarrollo de sus operaciones. Finalmente se detallan las conclusiones derivadas de la investigación documental, investigación de campo y del análisis de los resultados. Además, se presentan las recomendaciones necesarias, para que el personal que labora en el sector financiero tenga una mejor y mayor participación en el diseño o mejora al proceso de control interno, como una forma que impida la monotonía e inercia de los controles, y así lograr la efectividad de los controles existentes.

Significado regional dos depósitos neogénicos continentais da área de Vila de Rei (Portugal Central)

In the Vi la de Rei arca (Central Portugal) the continental deposits ofthe Lower Tagus Tertiary 8asin lay upon the pediment of me Portuguese Central Chain. Three ronglomerate units are recorded from me base upwards. separated by regional or basinal unconfonnities: Conglomerados de Rio de Moinhos (RM); Conglomerados de Serra de Almeirim (SA) and Conglomerados de Vila de Rei (VR). The first two units (KM and SAl have been si les of gold exploitation in huge optn pit mines probably dunng Roman colonisation times. The contact ofthis units, on thc Paleozoie basement or on the Paleogene unil Grés de Monsanto, is unconfonn, defining in both limits a large nondepositional andlor erosional hiatus. Those conglomerates seal the scdimcntation ofthe Lower Tagus Tertiary Basin along irs northem border. Taking lnto account lhe significance /lssigned to their basinal unconfonnity limits, lhe uplift ofthe Portuguese Centra! Chain. and thc facl ofthis continental units yielded no fossils with chranostratigraphic significanee, they have been eonsidered ranging fram Uppcr Miocene to lhe beginning ofthe Qualemary. Finally, a lithostratigraphic equivalence with lhe Neogenic units ofthc Bierzo and Duema basins (NW ofthe Iberian Peninsula), where exploitalions from Roman limes are also evident, is presented.

Enquadramento legal e estudo económico de parques eólicos

Portugal, no intuito de alcançar metas ambientais e económicas a que se propôs, e de reduzir a dependência das importações de energia, tem aumentado o investimento em eletricidade produzida a partir de energias renováveis (FER-E). Apesar do consenso em torno da sua utilização, as energias renováveis deparam-se com barreiras de várias ordens que dificultam a sua difusão no mercado. A atuação do Estado neste enquadramento passa por criar modelos de promoção da FER-E. A maioria dos países da União Europeia, incluindo Portugal, aplica as tarifas feed-in (FIT) como instrumento central de suporte à FER-E, inserido num modelo de apoio que contempla outros parâmetros de construção considerados críticos para o seu sucesso. No seguimento do estágio realizado na empresa Senvion Portugal a presente tese explora os programas e modelos de apoio às FER-E em Portugal, nomeadamente as que se referem à energia eólica. Bem como os trabalhos realizados com as equipas de O&M e a realização de um estudo de viabilidade económica da substituição de aerogeradores no parque eólico de Picos Verdes II.

Teoria de carteiras e a alocação de parques eólicos offshore

The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore

EVALUACIÓN DE LA PROPUESTA PARA EL ESTABLECIMIENTO DE UN SISTEMA DE GARANTÍA DE DEPÓSITOS EN EL SISTEMA FINANCIERO COSTARRICENSE

El objetivo principal de este documento consiste en evaluar el impacto que tendría sobre la exposición neta de los pasivos de los intermediarios financieros, el establecimiento de un sistema de seguro de depósitos tal como se encuentra propuesto en el Proyecto de Ley de Reformas de la Ley Orgánica del Banco Central de Costa Rica, la Ley Orgánica del Sistema Bancario Nacional y otras Leyes. Para tal efecto se recurre a la estimación de diferentes coberturas de pasivos y se realiza el análisis de diferentes escenarios.Los principales resultados indican que en el caso de los bancos estatales, contar con un fondo como el propuesto en el Proyecto analizado, permite reducir la exposición neta de los pasivos de un 40% a un 18% aproximadamente, lo cual significa que el aporte que deberá realizar el Gobierno se reduce considerablemente y con ello los costos que debe asumir la sociedad en términos de inflación ante un eventual problema financiero de un banco estatal.En cuanto a los bancos privados, existe diversidad en cuando a la capacidad de cubrir los pasivos, hay entidades que representan un mayor peso para el Fondo de Seguro de Depósitos propuesto, en tanto otras no presentan mayores problemas de cobertura.Por último debe destacarse que la metodología empleada constituye en si misma un aporte para ser considerada dentro de un sistema de indicadores de alerta temprana, puesto que muestra en forma indirecta el comportamiento de la calidad de activos y el apalancamiento.

COMPETENCIA POR DEPÓSITOS EN LA BANCA COSTARRICENSE: EL CASO DE LA BANCA ESTATAL

El artículo evalúa la intensidad de la competencia que enfrentan los bancos estatales en la captación de depósitos, en particular el Banco Nacional y el Banco de Costa Rica y, utiliza como metodología la determinación del valor de la elasticidad-interés por sus depósitos. La evidencia indica que los bancos estatales cuentan con un poder monopolístico en la captación de depósitos y, además, que ese poder se incrementó a partir de 1996, lo cual indica que estos bancos tienen un mercado cautivo de depósitos que es independiente de la tasa ofrecida por ellos y/o por sus competidores. Así, los bancos estatales pueden disminuir o aumentar las tasas de interés pagadas por sus depósitos y esto no tiene prácticamente ningún efecto sobre las cantidades de recursos financieros que los depositantes están dispuestos a llevarles, o, los competidores pueden elevar sus tasas muy por encima de las pagadas por estos bancos y no se producirá una reducción significativa de los depósitos de los bancos estatales.

VIABILIDAD DEL SEGURO DE DEPÓSITOS EN COSTA RICA

El objetivo principal de este artículo es estimar si el establecimiento del seguro de depósitos explícito en Costa Rica es viable o no, así como, exponer las principales características de dicho sistema de protección.Adicionalmente, se considera oportuno iniciar el debate sobre un tema que ha sido postergado y que debería ser de interés en el ámbito financiero nacional. Por tanto, es necesario animar la discusión de este tema en foros bancarios para ir generando ideas alternativas y conclusiones que contribuyan con el fortalecimiento y desarrollo del sistema financiero y no esperar hasta que la crisis sistémica (peligro latente de contagio sobre el resto del sistema) se muestre a la vuelta de la esquina.El riesgo de las crisis sistémicas ha llevado a muchos países a estudiar e implementar sistemas de seguro de depósitos (SSD), con el interés de minimizar el efecto dominó o contagio que podría generar una corrida de fondos bancarios, dada una situación de desconfianza en los depositantes por la pérdida de sus recursos, producto de la quiebra de un banco.En Costa Rica, el establecimiento del seguro de depósitos explícito debe formar parte de la agenda de estudio de las Reformas del Sistema Financiero, puesto que el SSD junto con la función de prestamista de última instancia y la supervisión prudencial conforman los cimientos de seguridad básica de un sistema financiero moderno e inmerso en la globalización.Por su parte, los resultados de la estimación del seguro de depósitos para nuestro país, mostraron que la implementación es viable desde el punto de vista financiero, según criterio de expertos. Además, el impacto estimado sobre el margen financiero se considera insignificante para los participantes en el sistema bancario. Por tanto, se estaría rompiendo con el mito de que el seguro de los depósitos vendría a ser un impuesto adicional importante, sino más bien un beneficio, en el sentido de la mayor confianza y estabilidad que daría al sistema financiero y al mecanismo de pagos.

Simulación de excavaciones urbanas mediante modelos de elementos finitos en depósitos sedimentarios de origen aluvial en Sabaneta

En este trabajo se realizan simulaciones de excavaciones profundas en suelos de origen aluvial en la ciudad de Sabaneta, mediante el empleo de modelos en elementos finitos integrados por el software PLAXIS® -- Los desplazamientos horizontales son comparados con mediciones de inclinómetros instalados en el trasdós del muro diafragma anclado del proyecto Centro Comercial Mayorca Fase III, localizado en el municipio de Sabaneta, Antioquia -- Finalmente, se concluye acerca de la sensibilidad de los parámetros más relevantes según el modelo constitutivo empleado y la viabilidad en su aplicación para la solución del problema evaluado