Localização de faltas em linhas de transmissão de múltiplos terminais a partir de registros oscilográficos sincronizados via transformada wavelet

The electric energy is essential to the development of modern society and its increasing demand in recent years, effect from population and economic growth, becomes the companies more interested in the quality and continuity of supply, factors regulated by ANEEL (Agência Nacional de Energia Elétrica). These factors must be attended when a permanent fault occurs in the system, where the defect location that caused the power interruption should be identified quickly, which is not a simple assignment because the current systems complexity. An example of this occurs in multiple terminals transmission lines, which interconnect existing circuits to feed the demand. These transmission lines have been adopted as a feasible solution to suply loads of magnitudes that do not justify economically the construction of new substations. This paper presents a fault location algorithm for multiple terminals transmission lines - two and three terminals. The location method is based on the use of voltage and current fundamental phasors, as well as the representation of the line through its series impedance. The wavelet transform is an effective mathematical tool in signals analysis with discontinuities and, therefore, is used to synchronize voltage and current data. The Fourier transform is another tool used in this work for extract voltage and current fundamental phasors. Tests to validate the location algorithm applicability used data from faulty signals simulated in ATP (Alternative Transients Program) as well as real data obtained from oscillographic recorders installed on CHESF s lines.

Contribuições para a detecção e identificação de faltas em inversores Multiníveis

This work presents contributions in the detection and identication of faults in multilevel inverters through the study of the converters behavior under these operation conditions. Basically, the approached fault consists of an open-circuit in any switch of a three-level clamped diode inverter. The converter operation is characterized in the pre and post-fault states. A wave form behavior analysis of the pole voltage, phase current and dc-bus current is also done, which highlights characteristics that allow the detection of failure and, even, under favorable conditions, the identication of the faulty device. A compensation strategy of the approached fault (open-switch) is also investigated with the purpose of maintaining the driving system operational when a failure occurs. The proposed topology uses SCRs in parallel with the internal switches of the inverter, which allows, in some occasions, the full utilization of the dc-bus

Localização de faltas em linhas de transmissão usando morfologia matemática

This work an algorithm for fault location is proposed. It contains the following functions: fault detection, fault classification and fault location. Mathematical Morphology is used to process currents obtained in the monitored terminals. Unlike Fourier and Wavelet transforms that are usually applied to fault location, the Mathematical Morphology is a non-linear operation that uses only basic operation (sum, subtraction, maximum and minimum). Thus, Mathematical Morphology is computationally very efficient. For detection and classification functions, the Morphological Wavelet was used. On fault location module the Multiresolution Morphological Gradient was used to detect the traveling waves and their polarities. Hence, recorded the arrival in the two first traveling waves incident at the measured terminal and knowing the velocity of propagation, pinpoint the fault location can be estimated. The algorithm was applied in a 440 kV power transmission system, simulated on ATP. Several fault conditions where studied and the following parameters were evaluated: fault location, fault type, fault resistance, fault inception angle, noise level and sampling rate. The results show that the application of Mathematical Morphology in faults location is very promising

Metodologia de estimação de estados para tratamento de medições errôneas e registros não sincronizados em algoritmos de localização de faltas em linhas de transmissão

The performance of algorithms for fault location i n transmission lines is directly related to the accuracy of its input data. Thus, fa ctors such as errors in the line parameters, failures in synchronization of oscillographic recor ds and errors in measurements of voltage and current can significantly influence the accurac y of algorithms that use bad data to indicate the fault location. This work presents a new method ology for fault location in transmission lines based on the theory of state estimation in or der to determine the location of faults more accurately by considering realistic systematic erro rs that may be present in measurements of voltage and current. The methodology was implemente d in two stages: pre-fault and post- fault. In the first step, assuming non-synchronized data, the synchronization angle and positive sequence line parameters are estimated, an d in the second, the fault distance is estimated. Besides calculating the most likely faul t distance obtained from measurement errors, the variance associated with the distance f ound is also determined, using the errors theory. This is one of the main contributions of th is work, since, with the proposed algorithm, it is possible to determine a most likely zone of f ault incidence, with approximately 95,45% of confidence. Tests for evaluation and validation of the proposed algorithm were realized from actual records of faults and from simulations of fictitious transmission systems using ATP software. The obtained results are relevant to show that the proposed estimation approach works even adopting realistic variances, c ompatible with real equipments errors.

Os filhos evangélicos do novo caldeirão do diabo: a conversão religiosa na penitenciária de alcaçuz

The theme of the research is inserted at a field of intersection between the Sociology of Religion and Sociology of Violence, having as the general objective study the sociological meaning of the conversion of prisoners that lives at the biggest prison (Prison of Alcaçuz) of Rio Grande do Norte to the evangelical churches. The research is justified, because Brazil shelter the fourth greater arrested population arrested of the world, with projections indicating that it can turn the greatest in 2034. Besides, this study about religious conversion of prisoners to the Social Sciences is too important, because is a theme little developed in Brazil and deserves attention, one time that as the arrested people as the evangelicals are in expansion in our country. Starting from the precedent observations, we guide ourselves by the following problematic of research: the religious practice in Alcaçuz presents a mere instrumental perspective, where the actions of prisoners converted was on purpose oriented to conquest material or symbolic privileges; or purely religious, where seek a moral renovation? To develop the work, the scientific methodology adopted was exploratory and explanatory, using the Goffman´s theory about total institutions and presentation of self, and Blumer´s doctrine relating to Symbolic Interacionism and the Story life method, besides considerations about evangelical religion. Having this theoretical basis, was accomplished the Field research, when were made interviews and applied questionnaires to 11 Jailer Agents, 31 prisoners, Director and Vice-Dictor (in November, 2011), the coordinator of social projects of the prison and the coordinator of evangelization at the prisons in Rio Grande do Norte. As results, it was seeing in Alcaçuz that the prisoners can be separated in two groups: the one of Pavilions and other one of the Medical Section. The Pavilions are branded for managerial and structural problems, where are found idle prisoners in collective cells and with a historical of escaping attempts, mutinies and murders. The Medical Section has some individual cells or destined for two people, besides few collective also, and the prisoners work and have a more disciplined behavior, there isn t escapes or rebellions and that, for these reasons end for have more confidence from the Administration. About the presence of evangelical prisoners, most are at Medical Section, where exist a specific place to the cults (what doesn t at Pavilions). At the end, the conclusion is that the prisoner that says himself evangelical in Alcaçuz, although can be seeing with distrust about your real conversion, he gets win a trust vote and until the opposite being demonstrated in other words, that he is not hiding himself behind the bible to divert the vigilance of Direction and practice disciplinary faults without make any suspicions, is treated with more respect and has more opportunities live at Medical Section; have work, that most of times is paid and guarantee the homologation of your payment of penalty with work, besides other benefits, diminishing his time in jail

Tecendo os fios de rede: juventude e produção de si em projetos sociais.

The study is about youthful subjectivities in quarters, of the West Zone of Natal-RN, marked for lacks and contingencies that constitute the everyday life of the social existence of its young inhabitants. For this purpose the researchers selected two youth groups: the Association of Youths Constructing Dreams (in the quarter of Felipe Camarão) and Lelo Melodia Crew (Quarter of Guarapes). Both are articulated through the strategy of coalition in regional and national nets. The hypothesis is that inside the groups and nets new youthful citizens arises. That would be a change in the representation of poor youth: from 1980 s street children - young whose social stigma associated poverty and crime to late 1990 s kids of project (pointing their trajectory in social projects) or, in present days, called as young peripherals - for the enrollment in cultural movements, as the hip hop movement - These new young citizens are contributing to new social imagery significations on poor youths. The methodology encloses: a) focal group; b) participant research analyzing the making arts (ways to think, social daily practices, actions engaged in a diversity plans) of youth groups; c) life stories of some of the youngs produced in workshops; d) not structuralized interviews. d) several documents of the groups; e) local and national surveys. Results emphasize a feeling of opening to a project of autonomy in relation to a social system that leaves them in a situation of social precariousness. Conclusion remarks that such practices of the youthful groups through the art, leisure, sport and culture unfold politics effect so that can point innovative forms of politics participation on the part of this specific segment of poor youths of Brasilian country, although conflicts and paradoxes crosses individual citizens, youth groups and youth nets.

Aconselhamento em HIV/AIDS: ações e reflexões dos profissionais do Centro de Testagem e Aconselhamento (CTA)

The counseling on HIV/Aids consists in a prevention strategy that contributes to increase the diagnosis of HIV and start earlier the treatment. The counseling has as pillars the emotional and educational support, risks evaluation that aim at the adoption of safe practices and the individual s responsibility for his own health. To accomplish these results, it is necessary that health workers understand counseling as a unique educational moment that stimulates the user s critical-reflection when it comes to his role as an active subject in this process. This study aimed to analyze the counseling on HIV/Aids conducted by the professionals of the Testing and Counseling Center (CTA), based on the educational perspective of Paulo Freire . This is a descriptive qualitative study with a critical reflexive design based on the principles of Action-Science. All the professionals acting as counselors in the Joao Pessoa, PB CTA, eight in total, took part in the study. Data were collected during the month of March, 2011, through non participative observation and semi-structured interviews with a critical-reflexive focus, analyzed according to the tenets of the critical-reflexive methodology, and discussed taking into consideration the Paulo Freire s pedagogy and pertinent literature. It was observed that most of the professionals expressed the work philosophy of CTA as the diagnosis and prevention of the disease, associated with the utilization and demonstration of condoms. However, upon observation of their counseling sessions, these ideas were not converted in actions. Educational themes were not covered and the condom wasn t offered at any time. The counseling actions focused on the provision of information and filling out the paper forms which are necessary for attendance. The sessions were conducted with brief dialogues and little opportunity for the users to expose or complement their thoughts and needs. The professionals mentioned as facilitating conditions for counseling, the team interaction and physical structure. The difficulties focused on the users low cognition, the large demand for attendance, aspects related to the service organization, and the counselors absences and delays. After reflecting about the actions observed in the counseling, the majority of professionals admitted the need to modify their practice in the incorporation of educational principles for the achievement of a broader prevention, and seemed to be willing to work in this perspective. In conclusion, although the counselors show ideas consistent with the purposes of CTA, these ideas are limited when it comes to the understanding of the meaning of prevention in HIV/Aids. Taking into consideration that they express a certain comprehension and act differently during the counseling, they demonstrate a lack of bond between the theories in use and the proposed ones, in accordance with the contribution of the action-science theory. The counseling, as an educative practice, doesn t materialize in the counseling itself and the orientation for reflection is not given during the attendance. These findings suggest the need to include the process of reflection in the execution of the actions of counseling, so that these practices are guided by reflexive practice, aiming at transforming the way of thinking and acting into a more educational perspective toward a more democratic and holistic assistance.

Comparação entre modelos equivalentes de aerogeradores síncronos utilizando o programa ATP

At present, the electricity generation through wind energy has an importance growing in the world, with the existence of very large plans for future wind power installation worldwide. Thus, the increasing the electricity generation through wind power requires, more and more, analysis of studies of interaction between wind parks and electric power systems. This paper has as purposes to implement equivalent models for synchronous wind generators to represent a wind park in ATP program and to check behavior of the models through simulations. Simulations with applications of faults were achieved to evaluate the behavior of voltages of system for each equivalent model, through comparisons between the results of models proposed, to verify if the differences obtained allows the adoption of the simplest model

Exercícios respiratórios para asma: revisão sistemática com metanálise

Introdução: A asma se tornou um problema de saúde pública devido aos seus grandes custos em cuidados de saúde. Os exercícios respiratórios constituem uma intervenção não farmacológica de baixo custo e baixo risco que vem sendo utilizada por fisioterapeutas em diferentes países no tratamento de pacientes asmáticos. Objetivo: Avaliar a eficácia dos exercícios respiratórios no tratamento de pacientes adultos com asma nos seguintes desfechos: qualidade de vida, sintomas da asma, número de exacerbações agudas, episódios de hospitalização, mensurações fisiológicas (função pulmonar e capacidade funcional), número de consultas médicas, número de faltas no trabalho devido a exacerbações da doença, avaliação subjetiva do paciente em relação à intervenção. Método: Revisão sistemática de estudos controlados randomizados com metanálise realizada em parceria com a Colaboração Cochrane. As seguintes bases de dados foram consultadas: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED, e PsycINFO, além de busca manual em revistas da área e em resumos de congressos. Os seguintes termos foram utilizados: (breath*) and (exercise* or retrain* or train* or re-educat* or educat* or physiotherap* or "physical therap*" or "respiratory therapy" or buteyko ). As listas de referências dos estudos selecionados e registros de ensaios clínicos também foram consultados. A seleção dos estudos e a avaliação do risco de viés dos estudos incluídos foram realizadas de maneira independente por dois revisores. O software Review Manager foi utilizado para análise dos dados, no qual o modelo de efeito fixo foi utilizado. As variáveis contínuas foram expressas como diferença de média ponderada com um intervalo de confiança de 95%. A heterogeneidade dos resultados dos estudos incluídos foi realizada por meio da análise dos Forest plots. O teste qui-quadrado (Chi2) com um P valor de 0.10 foi utilizado para indicar significância estatística. O Índice de heterogeneidade (I2) foi implementado com um valor acima de 50% como um nível substancial de heterogeneidade. Resultados: 13 estudos envolvendo 906 pacientes estão atualmente incluídos na revisão. Os seguintes desfechos foram mensurados pelos estudos incluídos: qualidade de vida, sintomas da asma, número de exacerbações agudas e função pulmonar. Os estudos relataram uma melhora na qualidade de vida, sintomas da asma e número de exacerbações agudas. Seis dos onze estudos que avaliaram função pulmonar mostraram uma diferença significativa favorável aos exercícios respiratórios. Não houve relato de efeitos adversos. Devido à heterogeneidade substancial encontrada entre os estudos, metanálise foi possível apenas para sintomas da asma, a qual incluiu dois estudos e mostrou uma diferença significativa favorável aos exercícios respiratórios. A avaliação do risco de viés foi prejudicada devido ao relato incompleto de aspectos metodológicos pela maioria dos estudos incluídos. Conclusão: Embora os resultados encontrados pelos estudos incluídos demonstraram individualmente que os exercícios respiratórios podem ser importantes no tratamento da asma, não há evidência conclusiva nesta revisão para suportar ou refutar a eficácia desta intervenção no tratamento de pacientes asmáticos. Este fato foi devido às diferenças metodológicas entre os estudos incluídos e à ausência de relato de aspectos metodológicos por parte da maioria dos estudos incluídos. Não há dados disponíveis em relação aos efeitos dos exercícios respiratórios nos seguintes desfechos: episódios de hospitalização, número de consultas médicas, número de faltas no trabalho devido a exacerbações da doença, e avaliação subjetiva do paciente em relação à intervenção

A inclusão escolar da subjetividade do professor à constituição de um lugar de aluno

The move to include students with special needs (NEE) in the schools presents a paradigm that raises continual discussion about how to implement this proposal. Considering that learning is built from the weaving of socially constructed knowledge and the field of knowledge concerning subjectivity, this research explores the difficulties that occur with the later in the process of inclusion in the schools. Admittedly, the promise implicit in the school does not guarantee that the student learn, but the envisioning of this learning, when the student s educator discredits him, is such that the person is then not taken on as an actual student, being excluded from the transmission of knowledge, even within the school. The project implemented at the Instituto Educacional Casa Escola IECE, for the last three years, shows us that the possibility and sustainability of this envisioning is intimately linked to the subjectivity of the educator, as well as how one relates to the institutional culture. We question then, how this perspective is formed in the educator this perspective capable of denying the offer of a place as student, allowing him to advance while learning. With this in mind, we explore the paradoxical elements present in the paradigm of inclusion, as well as analyzing theoretically, through the body of conceptual psychoanalysis, the process of subjective constitution. We intend to bring to light how this process coincides with the construction of the educator s perspective of exemption from teaching the special needs students. We question, through the formative functions of subjective structuring (The Mirror Stage and the Oedipus Complex), how to form a perspective capable of promoting inclusion of special needs students in educators. Finally, we show how it is possible to bring to light, with the concepts of the I ideal and the ideal I, the subjective difficulties in the practicing instructor

Frequencia de enteroparasitoses em usuários do servico público de saúde na mesorregião do oeste potiguar

Em um mundo de grande pobreza, as enteroparasitoses podem exercer um papel importante no que se refere às desigualdades sociais, pois estas mazelas se apresentam, em sua grande maioria, na população mais carente. Estas mesmas doenças causam inúmeros casos de faltas ao trabalho e a escola, gerando preocupação dos profissionais de saúde, já que estes parasitas podem agravar ou desencadear quadros de anemia e desnutrição. O trabalho procurou pesquisar a prevalência de enteroparasitas na Mesorregião do Oeste Potiguar, em uma população que utiliza o sistema público de saúde, buscando associar as variáveis, como: sexo, faixa etária, período sazonal, renda familiar e número de parasitas. Foi utilizada a técnica de Hofmann (sedimentação espontânea) e o material fecal foi analisado pelos funcionários do Laboratório Central de Mossoró e Pau dos Ferros. Foi realizado no período de 02 de março de 2010 a 28 de março de 2011 o exame coprológico em 16.246 pessoas no laboratório Central de Mossoró (Lacen) e Pau dos Ferros, RN. A análise dos exames mostrou que 69,23% dos infectados eram mulheres e 33,07% eram homens. A maior prevalência ocorreu com Endolimax nana (41,61%), seguido de Entamoeba coli (18,46%) e Giardia lamblia (18,59%) em 3.407 parasitas encontrados. Dentre os exames realizados, o Endolimax nana foi o mais prevalente entre os organismos encontrados. A diferença nos resultados entre mulheres e homens pode determinar um foco domiciliar, pelo descaso do poder público com as políticas de saneamento básico e falta de higiene da população, e pela atividade das mesmas com trabalhos domésticos

Avaliando a robustez e manutenibilidade do comportamento excepcional de aplicações C#

Mainstream programming languages provide built-in exception handling mechanisms to support robust and maintainable implementation of exception handling in software systems. Most of these modern languages, such as C#, Ruby, Python and many others, are often claimed to have more appropriated exception handling mechanisms. They reduce programming constraints on exception handling to favor agile changes in the source code. These languages provide what we call maintenance-driven exception handling mechanisms. It is expected that the adoption of these mechanisms improve software maintainability without hindering software robustness. However, there is still little empirical knowledge about the impact that adopting these mechanisms have on software robustness. This work addresses this gap by conducting an empirical study aimed at understanding the relationship between changes in C# programs and their robustness. In particular, we evaluated how changes in the normal and exceptional code were related to exception handling faults. We applied a change impact analysis and a control flow analysis in 100 versions of 16 C# programs. The results showed that: (i) most of the problems hindering software robustness in those programs are caused by changes in the normal code, (ii) many potential faults were introduced even when improving exception handling in C# code, and (iii) faults are often facilitated by the maintenance-driven flexibility of the exception handling mechanism. Moreover, we present a series of change scenarios that decrease the program robustness

Uma ferramenta de análise automatizada de técnicas de seleção de testes de regressão baseada em mineração de repositórios de software

The main goal of Regression Test (RT) is to reuse the test suite of the latest version of a software in its current version, in order to maximize the value of the tests already developed and ensure that old features continue working after the new changes. Even with reuse, it is common that not all tests need to be executed again. Because of that, it is encouraged to use Regression Tests Selection (RTS) techniques, which aims to select from all tests, only those that reveal faults, this reduces costs and makes this an interesting practice for the testing teams. Several recent research works evaluate the quality of the selections performed by RTS techniques, identifying which one presents the best results, measured by metrics such as inclusion and precision. The RTS techniques should seek in the System Under Test (SUT) for tests that reveal faults. However, because this is a problem without a viable solution, they alternatively seek for tests that reveal changes, where faults may occur. Nevertheless, these changes may modify the execution flow of the algorithm itself, leading some tests no longer exercise the same stretch. In this context, this dissertation investigates whether changes performed in a SUT would affect the quality of the selection of tests performed by an RTS, if so, which features the changes present which cause errors, leading the RTS to include or exclude tests wrongly. For this purpose, a tool was developed using the Java language to automate the measurement of inclusion and precision averages achieved by a regression test selection technique for a particular feature of change. In order to validate this tool, an empirical study was conducted to evaluate the RTS technique Pythia, based on textual differencing, on a large web information system, analyzing the feature of types of tasks performed to evolve the SUT

Proteção diferencial de transformadores de potência utilizando a transformada Wavelet

About 10% of faults involving the electrical system occurs in power transformers. Therefore, the protection applied to the power transformers is essential to ensure the continuous operation of this device and the efficiency of the electrical system. Among the protection functions applied to power transformers, the differential protection appears as one of the main schemes, presenting reliable discrimination between internal faults and external faults or inrush currents. However, when using the low frequency components of the differential currents flowing through the transformer, the main difficulty of the conventional methods of differential protection is the delay for detection of the events. However, internal faults, external faults and other disturbances related to the transformer operation present transient and can be appropriately detected by the wavelet transform. In this paper is proposed the development of a wavelet-based differential protection for detection and identification of external faults to the transformer, internal faults, and transformer energizing by using the wavelet coefficient energy of the differential currents. The obtained results reveal the advantages of using of the wavelet transform in the differential protection compared to conventional protection, since it provides reliability and speed in detection of these events.

Proteção em sistemas elétricos com geração distribuída utilizando a transformada wavelet

A typical electrical power system is characterized by centr alization of power gene- ration. However, with the restructuring of the electric sys tem, this topology is changing with the insertion of generators in parallel with the distri bution system (distributed gene- ration) that provides several benefits to be located near to e nergy consumers. Therefore, the integration of distributed generators, especially fro m renewable sources in the Brazi- lian system has been common every year. However, this new sys tem topology may result in new challenges in the field of the power system control, ope ration, and protection. One of the main problems related to the distributed generati on is the islanding formation, witch can result in safety risk to the people and to the power g rid. Among the several islanding protection techniques, passive techniques have low implementation cost and simplicity, requiring only voltage and current measuremen ts to detect system problems. This paper proposes a protection system based on the wavelet transform with overcur- rent and under/overvoltage functions as well as infomation of fault-induced transients in order to provide a fast detection and identification of fault s in the system. The propo- sed protection scheme was evaluated through simulation and experimental studies, with performance similar to the overcurrent and under/overvolt age conventional methods, but with the additional detection of the exact moment of the fault.