Modelagem e análise dinâmica de um sistema de conversão de energia eólica dotado de gerador síncrono de imã permanente utilizando a plataforma ATP

Human development requires a broad balance between ecological, social and economic factors in order to ensure its own sustainability. In this sense, the search for new sources of energy generation, with low deployment and operation costs, which cause the least possible impact to the environment, has been the focus of attention of all society segments. To do so, the reduction in exploration of fossil fuels and the encouragement of using renewable energy resources for distributed generation have proved interesting alternatives to the expansion of the energy matrix of various countries in the world. In this sense, the wind energy has acquired an increasingly significant role, presenting increasing rates of power grid penetration and highlighting technological innovations such as the use of permanent magnet synchronous generators (PMSG). In Brazil, this fact has also been noted and, as a result, the impact of the inclusion of this source in the distribution and sub-transmission power grid has been a major concern of utilities and agents connected to Brazilian electrical sector. Thus, it is relevant the development of appropriate computational tools that allow detailed predictive studies about the dynamic behavior of wind farms, either operating with isolated load, either connected to the main grid, taking also into account the implementation of control strategies for active/reactive power generation and the keeping of adequate levels of voltage and frequency. This work fits in this context since it comprises mathematical and computational developments of a complete wind energy conversion system (WECS) endowed with PMSG using time domain techniques of Alternative Transients Program (ATP), which prides itself a recognized reputation by scientific and academic communities as well as by electricity professionals in Brazil and elsewhere. The modeling procedures performed allowed the elaboration of blocks representing each of the elements of a real WECS, comprising the primary source (the wind), the wind turbine, the PMSG, the frequency converter, the step up transformer, the load composition and the power grid equivalent. Special attention is also given to the implementation of wind turbine control techniques, mainly the pitch control responsible for keeping the generator under the maximum power operation point, and the vector theory that aims at adjusting the active/reactive power flow between the wind turbine and the power grid. Several simulations are performed to investigate the dynamic behavior of the wind farm when subjected to different operating conditions and/or on the occurrence of wind intensity variations. The results have shown the effectiveness of both mathematical and computational modeling developed for the wind turbine and the associated controls.

Ensino colaborativo e educação física: contribuições à inclusão escolar

In Brazil, special education public is a challenge to all teachers, especially to Physical Education ones. Among others, it encompasses students with disabilities, students with intellectual giftedness, and students with pervasive developmental disorder. Besides posing challenges, the inclusion process causes worry and generates debates on problems that impede the full partaking of such pupils in schooling practices related to physical education. This thesis presents a research that focused on these matters by means of co-working involving the researcher and the Physical Education teacher in regular classrooms following co-teaching perspective. The starting point of the research is the following question: what contributions co-working involving Physical Education teacher and researcher may provide to people with disabilities and to Physical Education teacher in regular schools attended by students who are the special education’s target? The research aimed at discussing and analyzing the development of such co-working activity involving the researcher and Physical Education teacher. It followed co-teaching perspective and was put into practice in a public school in Uberlândia, state of Minas Gerais. Participant qualitative approach, which recognizes relations between social sciences and intervention in social reality, was the methodological choice to develop the research in three phases: 1) making the research; 2) intervening in social reality; 3) assessing/diagnosing it. Strategies to gather data included semi structured interview, questionnaire, participant observation, and group interview. Data come, above all, from oral accounts as well as from the work by the group of participants of the research, which means, researcher, Physical Education teacher who works at regular schools and three teachers who deal with AEE (Atendimento Educacional Especial), a special educational teaching program. The concept of inclusion is discussed accordingly to authors such as Miranda (2001), Mantoan (2001), Duarte and Santos (2003), Mittler (2003), Rodrigues (2006), and Bueno (2008). The conception of co-working is developed in the light of studies by Capellini (2004) and Mendes (2009), among others. Results point out not only initial conditions of anguish, doubts and hardships, but also a will to debate difficulties Physical Education teachers face in their daily pedagogical activities at school. Likewise, results showed that teachers who took part in the research are interested in continuing their training in connection with co-teaching as strategy to teach physical education at inclusive schools.