Estudo comparativo de dois conversores Boost quadrático com comutação suave monochaveados para aplicação de rastreamento de máxima potência em sistemas fotovoltaicos

This paper makes a comparative study of two Soft Single Switched Quadratic Boost Converters (SSS1 and SSS2) focused on Maximum Power Point Tracking (MPPT) of a PV array using Perturb and Observe (P&O) algorithm. The proposed converters maintain the static gain characteristics and dynamics of the original converter with the advantage of considerably reducing the switching losses and Electromagnetic Interference (EMI). It is displayed the input voltage Quadratic Boost converter modeling; qualitative and quantitative analysis of soft switching converters, defining the operation principles, main waveforms, time intervals and the state variables in each operation steps, phase planes of resonant elements, static voltage gain expressions, analysis of voltage and current efforts in semiconductors and the operational curves at 200 W to 800 W. There are presented project of PI, PID and PID + Notch compensators for MPPT closed-loop system and resonant elements design. In order to analyze the operation of a complete photovoltaic system connected to the grid, it was chosen to simulate a three-phase inverter using the P-Q control theory of three-phase instantaneous power. Finally, the simulation results and experimental with the necessary comparative analysis of the proposed converters will be presented.

Das saudades que se tem: a representação paterna na escrita autobiográfica de Bartolomeu Campos de Queirós

In our work, we analyze some works of Bartolomeu Campos de Queirós that compose the “autobiographical cycle”, especially those ones that bring the image of father’s absence/presence, the relationship between life and writing, as well as the father’s figurations and his intermediates and substitutes. We especially investigated the aspect of repetition about how the family relations are articulated, highlighting those ones that happen between father and son and that appear in these texts. This problematic interested us as a research object, a priori, because the works of Bartholomeu Campos de Queirós are an exponent of literature for children field, as far as they show that the childhood is not always “colorful”, happy and perfect as several productions supposedly made “for children” seek to have us believe. In addition, the selected texts that have an autobiographical characteristic and put the issue of child suffering because of the father’s absence are configured as a very rich corpus for studies related to the relation between life/work and investigations in the dialogue between Literature and Psychoanalysis. These aspects will permit us to understand why the pain of missing father be repetitive and insistent in these books. Thus, we problematize, by the selected works for this study, the concept of literature for children and young people and the notion of literary reading. We also analyzed in the “statements” given by the author the relationship between life and writing and we investigated, based on psychoanalytic studies, the literary writing as a possibility of both unconscious development of memory marked by the father’s absence – remedy – as of a perpetuation of this same conflict – poison. Furthermore, we analyzed how the relationship between son and father are processed considering the mother’s absence, since the works that have this person’s presence, she seems to mediate such relationships in a certain way.