Superconductivity Centennial Conference 2011- EUCAS–ISEC–ICMC (18-23 Sep 2011, The Hague, The Netherlands)

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[pt] Os equipamentos elétricos de alta tensão são peças fundamentais na produção industrial. Porém, os sistemas de isolamento são os que mais apresentam problemas ao longo da vida útil dos nossos equipamentos. Suas propriedades dielétricas são alteradas ao longo do tempo e, desta forma devem ser monitoradas. Dentre as principais anomalias acometidas aos sistemas de isolamento, estão as Descargas Parciais (DP).Elas são resultado do rompimento da rigidez dieétrica do material isolante submetido a um intensivo campo elétrico . Até alguns anos atrás, em virtude da existência dos mecanismos de medição que possibilitassem o armazernamento de dados, muito pouco se efetuava para o acompanhamento das condições apresentadas pelos sistemas de isolamento.Com advento de sistemas digitais,esta limitação foi vencida. No entanto, a obtenção de dados reais e sua posterior avaliação são mecanismos que ainda carecem de um bom número de anos de experiência para sua elucidação. Esse fato advém,principalmente, da dificuldade em obtê-los .Como forma de contornar problema de falta de dados reais, foram desenvolvidas as célualas que têm como características simular os principais tipos de defeitos existentesnos sistemas de isolamento de alta tensão.Essas células são isoladas por materiais dielétricos idênticos ao que são usados em equipamentos elétricos reais. Dessa forma, foi possível a simulação de defeitos e a posterior aquisição, através do método eletromagnético de medição de DP, de um número suficiente de dados. Esses dados foram,então, aplicados no ajuste do sistema de reconhecimento de padrões de DP, onde se faz uso da teoria fractal, como um mecanismo de compactação de dados, por meio das grandezas fractais denominadas de dimensão fractal e lacunaridade, e também das redes neurais artificiais, com a utilização de um algoritmo supervisionado através do modo de treinamento back-propagation.Essa etapa,denominada de laboratorial, foi de fundamental importância para obtenção de conhecimento experimental bastante útil para a aplicação em ambientes reais.Outra fonte de informação também foi disponibilizada e se refere aos níveis de gases encontrados nas amostras de óleo colhidas junto aos transformadores de potência. Esta análise, conhecida como análise cromatográfica,baseia-se na existência de determinados tipos de gases para apontar o tipo de anomalia acometida ao sistema de isolamento do equipamento elétrico.Embora existam alguns métodos capazes de realizar tal diagnóstico, a tese fez uso das informações de um especialista.Essas afirmações foram então empregadas em um sistema neuro-fuzzy hierárquico, que tem como fundamento a extração de regras que relacionam os níveis de gases obtidos pela cromatografia gasosa com o tipo de anomalia existente no sistema de isolamento .Após esse processo um conjunto de transformadores de potência reais foi monitorado através de técnicas de cromatografia e do método eletromagnético.As duas técnicas, portanto, são usadas para estimar a ocorrência de DP nos sistemas de isolamento e, cosequentemente, o nível de degradação dos mesmos.Desta forma, a tese apresenta um sistema de diagnóstico que se utilizada de dados internos ao sistema de isolamento dos equipamentos elétricos baseados na ocorrência de DP. Esse sistema indica, ao seu final, um conceito sobre o atual estado operativo do mesmo, podendo este ser utilizado em um planejamento mais adequado que previna perdas intempestivas. A avaliação de desempenho do modelo, tanto laboratorial quanto em campo, apresentou ídices elevados, culminando em uma confirmação visual interna de um equipamento real, que comprova a eficiência e a importãncia do sistema. / [en] High voltage (HV) power apparatus are fundamental parts in the industrial process. It is also well Known that electrical insulation systems are the parts that present more problems through the life cycle of an HV apparatus. The dielectric properties of materials are altered during operation time and for this reason they should be monitored. Among the main anomalies that can affect the insulation systems are the Partial Discharges (PD). They are result of a partial failure of the dielectric rigidity of the insulating material submitted to an intense electric field.Until recently, probably due to the inexistence of measurement mechanisms that made possible the storage of data, very a little could be done to accompany the actual condition of insulation systems. With the coming of digital systems, this limitation was overcome.However, the obtention of real data and their subsequent evaluation are mechanisms that still will demand a good number of years of experience to perfect . This fact occurs, mainly, due to the difficulty in obtaining those data .As a way to the problem of lack of real data, special cells development with the purpose of simulating the principal types of defects that occur in HV insulation equipment . In that way, it was possible to do both the simulation of the defects and the measurement and acquisition, through the electromagnetic measurement method, of an expressive number of data. Those data were used to adjust a system of pattern recognition of PD, using artificial neural networks, where it is also made use of the fractal theory, as a mechanism of data compression, by measures of fractal dimension and lacunarity. That stage, denomited laboratory, was of fundamental importance to the obtention of experimental . Knowledge very useful to the development of real operating systems .Another source of information that was also available refers to the levels of gases found in oil samples from the interior of power transformers. This analysis, known as analysis of dissolved gases or chromatography, is based on the existence of certain types of gases as an indication of the type of anomaly on the electrical insulation system. Although some mehods exist, capable of accomplishing such diagnosis, the thesis made use of a specialist`s information. Those statements were used then in a hierarchical neuro-fuzzy model, designed method, with the type of anomaly existent in the insulation system. After that process, a real sample of operating HV power apparatus was monitored using the two analysis techniques, the chromatography and the electromagnetic method of PD measurement.Therefore these two techniques, are used to estimate the PD activity in the insulation systems and, consequently, their level of degradation . In resume the thesis presents a diagnosis system that makes use of internal data from the electrical insulation system with base in the PD occurrence. That system indicates, at the end, a concept of its current operative state, being able to be used in a more appropriate planning in order to prevent inopportune losses. The evaluation of the model, as much of simulating as in field, present high indexes and a visual confirmation intern of a real equipment, that proves the efficiency and the importance of system.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A questÃo ambiental tornou-se, na contemporaneidade, um fenÃmeno cultural planetÃrio que afeta atà mesmo nossa condiÃÃo de sujeito. InstituÃda como governamentalidade ambiental, tem como suporte um complexo saber-poder - o dispositivo da natureza - que se impÃe como mecanismo de controle das relaÃÃes com a natureza, cuja emergÃncia, formaÃÃo e funcionalidade sÃo analisadas nessa investigaÃÃo, com base na ―arqueogenealÃgica‖ formulada por Michel Foucault. A verdade ambiental à a luz comum de governantes e governados e requer, de um e de todos, o dever de salvar o planeta,de cuidar da natureza, de fazÃ-la viver. Uma natureza frÃgil, adoecida, em perigo, sob o signo da finitude surge, nos dias de hoje, como passivo de uma humanidade subjetivada como poluidora. Uma complexa estrutura educacional, constituÃda por mÃquinas imagÃticas discursivas e tÃcnicas polÃticaspedagogiza a sociedade, formando e controlando modos de pensar e agir, desejar e imaginar, consumir e produzir, de lucrar segundo a racionalidade ambiental, que se efetiva como verdade cientÃfica e norma Ãtica, valor e padrÃesde condutas para se habitar o Planeta. O capitalismo, sob a Ãtica ambiental, à a fonte nÃo da desestabilizaÃÃo das relaÃÃes com a natureza, mas de recursos para a reversÃo da crise ambiental, com base na ―hiper-industrializaÃÃo‖, ―ecologizaÃÃo‖ da economia e na ―economizaÃÃo‖ da ecologia. Apoiada em tÃcnicas polÃticas como a agroecologia, agricultura orgÃnica, permacultura, agricultura natural, entre outras, a racionalidade ambiental subjetiva segmentos populacionais rurais como ―produtores verdes‖ e forma novas ruralidades. Ao mesmo tempo, incita novas condutas e estilos de vida,no meio urbano, com base em mecanismos polÃticos como ―consumo consciente‖, ―troca justa‖, ―lucro verde‖, ―produÃÃo limpa‖ etc. Um mecanismo de poder de gestÃo da temporalidade faz projeÃÃes de prognÃsticos ambientais que preveem acontecimentos de escassez de recursos naturais, como Ãgua e alimentos; a ocorrÃncia de catÃstrofes como degelo, aumento do nÃvel do mar, ondas de frio e de calor, enchentes, inundaÃÃes, desertificaÃÃes, avanÃando em um crescente cuja culminÃncia à o fim da vida, o fim do mundo, a morte da Terra e da natureza que a sustenta. Assim, a governamentalidade ambiental controla o presente, governa populaÃÃes e indivÃduos, empresas e naÃÃes, fazendo prevalecer os interesses da ordem mundial na gestÃo da ordem ambiental. A base dessa racionalidade à o princÃpio de degradaÃÃo, que dispÃe que a destruiÃÃo da natureza à obra de cada um e de todos. Esse princÃpio à a base do saber ambiental; teorias como a da Sociedade de Risco, da ModernizaÃÃo EcolÃgica e do Desenvolvimento SustentÃvel sÃo tributÃrias e disseminamesse princÃpio do discurso ambiental, nas reflexÃes morais, anÃlises polÃticas e no pensamento cientÃfico. A verdade ambiental governa o mundo contemporÃneo, sem ser visibilizada ou contestada. Esse estudo à um contributo para modificar essa situaÃÃo. / The environmental issue became, nowadays, a cultural planetary phenomenon that affects even our subjectivity. Created as environmental governmentality, has as its support a knowledege-power complex â the nature device â that imposes itself as a controlling mechanism of relationships with nature whose emergence, forming and aplication are analyzed in this research based on Michel Foucaultâs âarcheo-genealogyâ. The environmental truth is the common light of rulers and ruled and requires, from each and everyone, the duty to save the planet, to care for nature, to make it live. A weak, sick, endangered nature, under the sign of finiteness emerges, in our times, as a passive of a polluting agent humanity. A complex educational structure composed of visual and discursive apparatuses and technical polictics âpedagogizesâ society, forming and controlling the ways of thinking and acting, desiring and imagining, consuming and producing, of profiting in accordance with a environmental rationality, which becomes effective as a scientific truth and ethical norm, values and conduct standards to inhabit the planet. The capitalism, under the environmental perspective, is not the source of nature relationship destabilisation, but of resources allocated to revert the environmental crisis, based on âhyper-industrializationâ, economy âecologizationâ and ecology âeconomizationâ. Backed by technical polictics as agroecology, organic agriculture, permaculture and natural agriculture, among others, the environmental rationality classifiesrural area population groups as âgreen producersâ and form new rural ways. At the same time, it stimulates new conducts and ways of life in the urban area, based on political mechanisms as âconsumer awarenessâ, âfair exchangeâ, âgreen profitâ, âclean productionâ, etc. A management temporality mechanism makes projections of future perspectives, which predicts events of shortage of natural resources, as water and food; the occurrence of catastrophes like thawing, sea level rising, heat and cold waves, floods disasters, desertification, making an increasing progress whose peak is the end of life, end of world, death of earth and of the nature which nurtures it. In that way, environmental governmentality controls the present, rules populations and individuals, corporations and nations, prevailing the global order interests in managing environmental order. The basis for this rationality is the principle of degradation, which provides that naturedestruction is work of each and everyone. This principle is the basis of the environmental knowledge; Risk Society, Ecological Modernization and Sustainable Development theories contribute to and spread this environmental discourse principle in moral considerations, political analysis and in scientific thought. The environmental truth governs the contemporary world without being visible or challenged. This study is a contribution to change this situation.

La presente investigación tuvo por finalidad analizar y desarrollar los criterios dogmáticos para la inclusión de la autoría mediata en aparatos de poder como una nueva modalidad de esta. Para ello fue relevante en un inicio, interpretar y analizar los criterios de la autoría mediata expuestos por Claus Roxin, y después de ello analizar la jurisprudencia y la doctrina nacional que hace referencia a esta modalidad de autoría mediata. Este estudio permitió brindar el problema de investigación, aplicando una metodología enfocado en garantizar el respeto por principios básicos procesales como el de legalidad y tipicidad, esto se logrará a través de una propuesta normativa que surge del análisis de la doctrina y jurisprudencia. / The purpose of this research was to analyze and develop the dogmatic criteria for the inclusion of mediate authorship in power apparatuses as a new modality of this. For this, it was initially relevant to interpret and analyze the criteria of mediate authorship exposed by Claus Roxin, and after that, analyze the jurisprudence and national doctrine that refers to this modality of mediate authorship. This study allowed us to provide the research problem, applying a methodology focused on guaranteeing respect for basic procedural principles such as legality and criminality, this will be achieved through a regulatory proposal that arises from the analysis of doctrine and jurisprudence.

High voltage rotating machines play a significant role in generation and use of electrical energy as the demand for power continues to increase. However, one of the main causes for down times in high voltage rotating machines is related to problems with the winding insulation. The utilities want to reduce costs through longer maintenance intervals and a higher lifetime of the machines. These demands create a challenge for the producers of winding insulations, the manufacturers of high voltage rotating machines and the utilities to develop new insulation materials which can improve the life of the equipment and reduce the maintenance cost. The advent of nanotechnology in recent times has heralded a new era in materials technology by creating opportunities to significantly enhance the properties of existing conventional materials. Polymer nanocomposites belong to one such class of materials that exhibit unique combinations of physical, mechanical and thermal properties which are advantageous as compared to the traditional polymers or their composites. Even though they show tremendous promise for dielectric/electrical insulation applications, there are no studies relating to the long term performance as well as life estimation of the nanocomposites. Considering this, an attempt is made to generate an understanding on the feasibility of these nanocomposites for electrical insulation applications. An epoxy based nanocomposite system is chosen for this study along with alumina (Al2O3) and silica (SiO2) as the nanofillers. The first and the foremost requirement for studies on polymer nanocomposites is to achieve a uniform dispersion of nanoparticles in the polymer matrix, as nanoparticles are known to agglomerate and form large particle sizes. A laboratory based direct dispersion method is used to process epoxy nanocomposites in order to get well dispersed samples. A detailed microscopy analysis of the filler dispersion using Scanning Electron Microscope (SEM) has been carried out to check the dispersion of the nanofiller in the polymer. An attempt is made to characterize and analyze the interaction dynamics at the interface regions in the epoxy nanocomposite by glass transition temperature (Tg) measurements and Fourier transform infrared (FTIR) spectroscopy studies. The values of Tg for the nanocomposites studied decreases at 0.1 wt% filler loading and then starts to increase gradually with increase in filler loading. This Tg variation suggests that there is certainly an interaction between the epoxy chains and the nanoparticles. Also no new chemical bonds were observed in the spectra of epoxy nanocomposite as compared to unfilled epoxy. But changes were observed in the peak intensity and width of the –OH band in the spectrum of epoxy nanocomposite. This change was due to the formation of the hydrogen bonding between the epoxy and the nanofiller. The thermal conductivity of the epoxy alumina and the epoxy silica nanocomposites increased even with the addition of 0.1 wt% of the filler. This increase in thermal conductivity is one of the factors that make these nanocomposites a better option for electrical insulation applications. The dielectric properties of epoxy nanocomposites obtained in this investigation also reveal few interesting behaviors which are found to be unique and advantageous as compared to similar properties of unfilled materials. It is observed that the addition of fillers of certain loadings of nanoparticles to epoxy results in the nanocomposite permittivity value to be lower than that of the unfilled epoxy over the entire range of frequencies [10-2-106 Hz] considered in this study. This reduction has been attributed to the inhibition of polymer chain mobility caused by the addition of the nanoparticles. The tan values are almost the same or lower as compared to the unfilled epoxy for the different filler loadings considered. This behavior is probably due to the influence of the interface as the strong bonding at the interface will make the interface very stable with fewer defects apart from acting as charge trapping centres. From a practical application point of view, the surface discharge resistant characteristics of the materials are very important and this property has also been evaluated. The resistance to surface discharge is measured in the form of roughness on the surface of the material caused by the discharges. A significant enhancement in the discharge resistance has been observed for nanocomposites as compared to unfilled epoxy/ microcomposites, especially at longer exposure durations. The partial discharge (PD) measurements were carried out at regular intervals of time and it is observed that the PD magnitude reduced with discharge duration in the case of epoxy alumina nanocomposites. An attempt was made to understand the chemical changes on the surface by conducting the FTIR studies on the aged surface. For all electrical insulation applications, materials having higher values of dielectric strengths are always desired and necessary. So AC breakdown studies have also been conducted. The AC breakdown strength shows a decreasing trend up to a certain filler loading and then an increase at 5 wt% filler loading for epoxy alumina nanocomposites. It has been also observed that the type of filler as well as the thickness of the filler influences the breakdown strength. The AC dielectric strength of microcomposites are observed to be lower than the nanocomposites. Extensive research by long term aging studies and life estimation are needed before these new nanocomposites can be put into useful service. So long term aging studies under combined electrical and thermal stresses have been carried out on unfilled epoxy and epoxy alumina nanocomposite samples of filler loading 5 wt%. The important dielectric parameters like pemittivity, tan  and volume resistivity were measured before and after aging to understand the performance of the material under study. The leakage current was measured at regular intervals and tan  values were calculated with duration of aging. It was observed that the tan  values increased drastically for unfilled epoxy for the aging duration considered as compared to epoxy alumina nanocomposites. The life estimation of unfilled epoxy as well as epoxy nanocomposites were also performed by subjecting the samples to different stress levels of 6 kV/mm, 7 kV/mm and 8 kV/mm at 60 oC. It is observed that the epoxy alumina nanocomposite has an enhanced life which is nine times the life of the unfilled epoxy. These results obtained for the nanocomposites enable us to design a better material with improved dielectric strength, dielectric properties, thermal conductivity, resistance to surface discharge degradation and enhanced life without sacrificing the flexibility in the end product and the ease of processing. Dry type transformers and stator winding insulation need to be cast with the above material developed and tested before practically implementing these in the actual application.