Estimação de Fasores para Proteção de Sistemas Elétricos Baseada em Mínimos Quadrados e Morfologia Matemática

This work proposes a new technique for phasor estimation applied in microprocessor numerical relays for distance protection of transmission lines, based on the recursive least squares method and called least squares modified random walking. The phasor estimation methods have compromised their performance, mainly due to the DC exponential decaying component present in fault currents. In order to reduce the influence of the DC component, a Morphological Filter (FM) was added to the method of least squares and previously applied to the process of phasor estimation. The presented method is implemented in MATLABr and its performance is compared to one-cycle Fourier technique and conventional phasor estimation, which was also based on least squares algorithm. The methods based on least squares technique used for comparison with the proposed method were: forgetting factor recursive, covariance resetting and random walking. The techniques performance analysis were carried out by means of signals synthetic and signals provided of simulations on the Alternative Transient Program (ATP). When compared to other phasor estimation methods, the proposed method showed satisfactory results, when it comes to the estimation speed, the steady state oscillation and the overshoot. Then, the presented method performance was analyzed by means of variations in the fault parameters (resistance, distance, angle of incidence and type of fault). Through this study, the results did not showed significant variations in method performance. Besides, the apparent impedance trajectory and estimated distance of the fault were analysed, and the presented method showed better results in comparison to one-cycle Fourier algorithm

Experiências subjetivadoras no limite da pele: Uma análise de práticas discursivas inscritas em tatuagens

This research aims to study the constitution of subjectivities in discursive practices included in imagistic and verbal texts of tattoos. Seeks to grasp the effects of meanings which translate emotions, experiences and disaffection that marked and / or transformed the lives of tattooed subjects. This thesis was anchored in Foucault's theories (1990, 2010, 2012) that address ways of subjectivity from the writing itself, transgression technologies as overshoot, opening new possibilities for discursive subject producing care of itself. Still notions from this analysis of French discourse (AD), as interdiscourse and discursive memory are used. The nature of qualitative research intends to contribute to the understanding of discourse as social practice constitutive of meaning in ways of being of the subject, as well as production of discourses about social norms. The corpus is composed of testimonials and imagistic and verbal texts of five subjects, among the ten respondents who tattooed experiences in the skin. The results show data demonstrating the constitution itself through lived experiences and printed on the skin. The meanings generated in the skin are types of subjectivities that reflect happiness, resilience, protection and immortality. We conclude that our subjects are positioned discursively in order to rebuild their bodies and experiences as necessary and that the images and statements recorded in bodies produce effects felt around the reflection about the ways of life and the existence choices of each one of the tattooed subjects.