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.

Impacto do trabalho noturno na qualidade de vida do profissional de enfermagem do gênero masculino

The nursing staff is now the largest contingent of professionals in healthcare environments, with more than 1.8 million professionals, and of these 15% are men, showing a masculinization of the historical profession and culturally conceived and carried out by women (COFEN / FIOCRUZ, 2013). This dissertation discusses the profession forward to some issues related to gender, quality of life and night work. Objective: To analyze the impact that shift work has the professional quality of life male, through a specific instrument to identify the main problems and joint damage to that front group to his professional activity. Methods: descriptivo, Cross-sectional study with a quantitative approach, performed with 72 professional male nursing staff, 41 (56.9%) nursing technicians, 18 (25%) of nursing assistants and 13 (18.1%) of nurses, in January 2015 in a university hospital in the city of Uberlândia (Minas Gerais). For this, we used the WHOQOL-BREF questionnaire. Quantitative variables were described as mean, standard deviation, maximum and minimum, in addition to the Shapiro-Wilk test and Kruskal-Wallis used in the data analysis, with a confidence level of 5% (p <0.05). Results: the profile of respondents, most are married 42 (58.3%) under the employment contract via Single Legal Regime 50 (69.4%) with mean age of 40 and having 16 years of service; and within a range of 0 to 100, the areas with better evaluation were the Social Relations (70.1) and psychological (67.5); already the worst were the Environment (57.4) and Physical (65.4). In the overall assessment, the average was 63.3 and staying below the national average (65-70). Thus, the professionals who were married obtained better scores, regardless of the category which is in the nursing team. Conclusions: The group is average, taking into account the standard deviation, but we can say that working conditions affect their profession, and these results allow the detection of the difficulties experienced by men of the nursing team, and can cooperate with the design strategies that benefit or minimize the search for conflicts that affect the health of these workers and their quality of life.