970 resultados para dupla negação


Relevância:

10.00% 10.00%

Publicador:

Resumo:

O número de catadores, caminhoneiros e trabalhadores informais que utilizam o trabalho com o lixo como forma de sobrevivência cresce em todo país. Sabe-se que esse tipo de trabalho oferece vários riscos à saúde física: no entanto, há poucos estudos sobre os efeitos que pode ocasionar na saúde mental. Diante disso, o presente estudo, de caráter exploratório, teve como objetivo compreender o sofrimento psíquico decorrente do trabalho de manuseio e triagem de resíduos sólidos recicláveis em trabalhadores de uma corporativa de reciclagem da região metropolitana de São Paulo. O referencial teórico utilizado foi a Psicodinâmica do Trabalho, disciplina clínica e teórica que se sustenta na descrição e no conhecimento das relações entre trabalho e saúde mental. Utilizou-se também o método específico da Psicodinâmica do Trabalho, regido pelos princípios da pesquisa-ação, que liga a intervenção à pesquisa. A coleta de dados se deu através da criação de um grupo de expressão, em que foram abordadas questões ligadas às vivências e experiências dos trabalhadores que manuseiam resíduos sólidos recicláveis. A análise dos dados mostra que a organização do trabalho neste caso torna-se pano de fundo para a problemática do sofrimento psíquico, uma vez que, na cooperativa, os trabalhadores têm certo controle sobre a realização da tarefa, podendo interferir no processo de trabalho. Constatou-se ainda que o sofrimento psíquico decorrente do trabalho assume diversas formas: a negação do risco à saúde física decorrente da precariedade e insalubridade do trabalho, que se concretiza pela não-utilização dos equipamentos de segurança (EPI) e por maus hábitos de higiene: a negação da dificuldade em manusear o lixo, pela busca de vantagens na atividade realizada que ajudem a suportar o contato com o que é sujo e desvalorizado e pela luta para manter-se no trabalho, que proporciona a cooperação entre os sujeitos - sendo a solidariedade e a cooperação as características mais marcantes nas relações entre esses trabalhadores. Entende-se que o trabalho realizado tem grande importância social, mas é preciso atentar para o fato de que o problema da destinação do lixo não pode superar a problemática dos efeitos sobre a saúde dos trabalhadores. Esse quadro só poderá ser alterado com melhores condições de trabalho e, principalmente, com o reconhecimento da atividade como algo fundamental para a sociedade e que, como tal, deve ser valorizado.(AU)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O presente estudo teve por objetivos: a) investigar conteúdos da psicodinâmica dos adolescentes infratores; b) descrever a percepção das interações afetivo-relacionais dos adolescentes em relação à figura paterna. Para isso foram estudados seis casos de adolescentes que cometeram infração e que cumprem medidas sócioeducativas, sendo cinco deles com 17 anos e um com 14 anos. Esses adolescentes freqüentavam o CEDECA (Centro de Defesa dos Direitos da Criança e do Adolescente) da cidade de Mauá (São Paulo), local onde os dados foram coletados. Foram utilizados como instrumentos o Procedimento de Desenho-Estória com Tema e entrevista semi-estruturada. A aplicação do procedimento foi feita com base nas seguintes instruções: desenhe um adolescente de Mauá e desenhe o pai de um adolescente de Mauá e, após cada desenho, foi pedido que o adolescente contasse uma história sobre o mesmo. De um modo geral, os resultados mostraram que o primitivismo e esteve presente na produção dos seis adolescentes, visto a presença de mecanismos de defesa como idealização, negação, cisão e outros mecanismos de defesa esquizóides. Também ficou evidente que a dificuldade de crescimento e evolução da personalidade, assim como a conduta anti-social estão associadas à qualidade da introjeção da figura paterna e a relação que estes adolescentes estabelecem com ela. Concluiu-se que o modo como se dá o desenvolvimento psíquico é fator determinante para que indivíduo seja levado á conduta delituosa. Por isso, são necessários mais estudos sobre a personalidade de adolescentes em conflito com a lei, para que o conhecimento científico possa contribuir em ações no âmbito familiar, bem como em programas de prevenção primária e secundária que possam dar condições de um bom desenvolvimento psíquico às pessoas antes que cheguem à adolescência e à idade adulta.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Esta dissertação tem por objeto “A Tributação Internacional dos Desportistas na Ótica dos Impostos sobre o Rendimento”, pretendendo-se analisar o objeto e o alcance das convenções fiscais bilaterais, no âmbito da tributação dos desportistas, caraterizando as suas regras, bem como as regras constantes da legislação nacional em sede de Imposto sobre o Rendimento das Pessoas Singulares (IRS) e de Imposto sobre o Rendimento das Pessoas Coletivas (IRC).A evolução da economia portuguesa, e em especial do desporto, fruto da globalização, internacionalização e mobilidade dos fatores de produção, verificada na União Europeia (UE) e a nível mundial, tem originado que cada vez mais fluxos de rendimentos e de capitais circulem de e para Portugal, factos que levam a que a Fiscalidade já não possa ser estudada de uma forma isolada sem se conhecer o regime das convenções de dupla tributação (CDT) celebradas por Portugal relativas aos impostos sobre o rendimento.A diversidade dos rendimentos auferidos, bem como a natureza dos serviços prestados, fazem dos desportistas das pessoas mais móveis do mundo, levantando-se as mais diversas questões no campo tributário, nomeadamente ao nível do conceito de desportista e da qualificação dos rendimentos por eles auferidos, a que pretendemos dar resposta ao longo deste trabalho. A maioria das CDT define como regra geral, no que concerne aos desportistas, a competência cumulativa para a tributação dos rendimentos auferidos pelos mesmos, suscitando desde logo a questão de saber se o modelo de tributação dos desportistas é suficiente ou necessário nos dias de hoje. A esta questão procuraremos dar resposta no final.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O tema escolhido para a minha tese de mestrado foram os Agrupamentos Complementares de Empresas (ACE). Na minha opinião, o tema dos ACE é um tema sempre atual, continuamos a verificar nos nossos dias o nascimento de diferentes ACE, por parte das empresas, e é por isso necessário percebermos o enquadramento dos ACE e como estes surgiram na nossa legislação. Os ACE surgiram no direito português pela lei nº 4/73, de 4 de Junho, e foi regulamentada pelo decreto-lei nº 430/73 de 25 de Agosto, tendo como objeto uma atividade auxiliar ou complementar daquelas que são exercidas por todos os que fazem parte do ACE. Ao referir-me aos ACE, não nos podemos esquecer de referir os AEIE – Agrupamentos Europeus de Interesses Económicos, uma figura similar aos ACE regulada pelo regulamento nº2137/85, do Conselho das Comunidades Europeias, de 25 de Junho e no DL nº 148/90 de 9 de Maio, este agrupamento é formado por membros de pelo menos dois estados diferentes da União Europeia. Estes dois agrupamentos estão devidamente regulados, possuem personalidade jurídica, são sujeitos de direitos e obrigações e têm como objetivo melhorar as condições de exploração ou os resultados das empresas agrupadas. Não posso falar de ACE nem AEIE sem me focar um pouco no regime que os sustem, o regime de transparência fiscal, este, consiste na imputação aos sócios da matéria coletável da sociedade determinada nos termos do CIRC, assim desconsidera-se o facto de existir uma sociedade coletiva e imputa-se a matéria coletável aos sócios. Os objetivos deste tipo de tributação são a neutralidade fiscal, o combate à evasão fiscal e evitar a dupla tributação.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O objectivo principal deste estudo é tentar identificar as possibilidades de melhoria das interfaces físicas das consolas centrais dos automóveis, e a sua ergonomia e usabilidade enquanto meio de realização de tarefas dentro do veículo, de modo a contribuir para melhorar a experiência e a segurança na condução. Neste estudo é feita uma investigação acerca de algumas das interfaces físicas das consolas centrais, medindo o seu desempenho no que diz respeito à distracção do condutor e facilidade de uso em situações de dupla tarefa. Para isso foi adaptado um simulador de condução, e uma bateria de testes de situações de dupla tarefa foi efectuada, de modo a obter dados de telemetria de condução e de desempenho de cada interface da consola central. Os dados obtidos acerca da trajectória do veículo e da sua comparação com trajectórias de referência e a velocidade média nos sectores de condução, foram comparados com dados de desvio de olhar, e que por sua vez sã o comparados e relacionados com os dados de percepção própria do condutor, obtidos através dos testes subjectivos de auto-percepção NASA - Administração Nacional da Aeronáutica e do Espaço - Raw Task Load Index (NASA RTLX). É esperado que desta análise possam ser encontradas algumas conclusões que deverão indicar oportunidades de melhoria às interfaces das consolas centrais, que possam resultar de uma combinação ou divisão dos sistemas, ou que abram caminho ao desenvolvimento de novas soluções alternativas, ou até à criação de um guia de boas práticas para o futuro design e desenvolvimento de interfaces de consolas centrais para automóveis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Surfactants are versatile organic compounds that have, in a single molecule, double chemical affinity. The surfactant molecule is composed by a hy drophobic tail group, a hydrocarbon chain (linear, branched, or mixed), and by a hydrophilic head group, which contains polar groups that makes it able to be applied in the organophilization process of natural clays. Microemulsions are microheterogeneous b lends composed by: a surfactant, an oily phase (non - polar solvent), an aqueous phase, and, sometimes, a co - surfactant (short - chain alcohol). They are systems with thermodynamic stability, transparent, and have high solubility power. Vermiculite is a clay m ineral with an expandable crystalline structure that has high cation exchange capacity. In this work vermiculite was used to obtain organoclays. The ionic surfactants dodecyl ammonium chlori de (DDAC) and cetyltrimethylammonium bromide (C 16 TAB) were used in the organophilization process. They were used as surfactant aqueous solutions and, for DDAC, as a microemulsion system. The organoclays were used to promote the separation of binary mixtures of xylene isomers (ortho - and meta - xylene). Dif ferent analytical techniques were used to characterize microemulsion systems and also the nanoclays. It was produced a water - rich microemulsion system with 0.92 nm droplet average diameter. The vermiculite used in this work has a cationic exchange capacity of 172 meq/100g and magnesium as main cation (24.25%). The basal spacing of natural vermiculite and organo - vermiculites were obtained by X - ray Diffraction technique. The basal spacing was 1.48nm for natural vermiculite, 4.01nm for CTAB - vermiculite (CTAB 4 ) , and 3.03nm for DDAC - vermiculite (DDAC M1A), that proves the intercalation process. Separation tests were carried out in glass columns using three binary mixtures of xylene (ortho - xylene and meta - xylene). The results showed that the organovermiculite pre sented an enhanced chemical affinity by the mixture of hydrocarbons, when compared with the natural vermiculite, and also its preference by ortho - xylene. A factorial experimental design 2 2 with triplicate at the central point was used to optimize the xylen e separation process. The experimental design revealed that the initial concentration of isomers in the mixture and the mass of organovermiculite were the significant factors for an improved separation of isomers. In the experiments carried out using a bin ary mixture of ortho - xylene and meta - xylene (2:1), after its percolating through the organovermiculite bed (DDAC M1), it was observed the preference of the organoclay by the ortho - xylene isomer, which was retained in greater quantity than the meta - xylene o ne. At the end of the treatment, it was obtained a final concentration in meta - xylene of 47.52%.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A abordagem metagenômica tem permitido o acesso ao material genético de microrganismos não cultivados e tem sido usada para identificação de novos genes. Apesar da importância dos mecanismos de reparo de DNA para a manutenção da integridade genômica nosso conhecimento sobre mecanismos de reparo de DNA é baseado em organismos modelo como E. coli e pouco é conhecido sobre os organismos de vida livre e não cultivados. Neste trabalho, a abordagem metagenômica foi aplicada para descobrir novos genes envolvidos com a manutenção da integridade genômica. Um clone positivo foi identificado por replicar a biblioteca metagenômica em meio seletivo contendo H2O2. O clone metagenômico foi capaz de complementar parcialmente a deficiência em reparo de DNA de cepas simples e duplo-mutantes de E.coli (recA e xthA nfo, respectivamente) submetidas ao estresse gerado por H2O2 e MMS.A análise de sequência mostrou uma ORF codificando para uma proteína hipotética membro da superfamília Exo_Endo_Phos (PF03372) e, a filogenia indicou que a mesma não está inclusa em nenhuma das subfamílias EEP. Assim, uma nova nuclease foi identificada e experimentalmente caracterizada in vivo e in vitro. Ensaios específicos utilizando a nuclease purificada e oligonucleotideos fluorescentemente marcados revelaram sua atividade 3´-5´exonuclease, em substratos simples e dupla-fita, dependente de Magnésio e sensível a EDTA. Uma vez que este é o primeiro relato e caracterização de uma enzima obtida a partir de abordagem metagenômica mostrando uma atividade exonuclease, foi nomeada EXOMEG1

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Frequency Selective surfaces are increasingly common structures in telecommunication systems due to their geometric and electromagnetic advantages. As a matter of fact, the frequency selective surfaces with fractal geometry type would allow an even bigger reduction of the electrical length which provided greater flexibility in the design of these structures. In this work, we investigated the use of multifractal geometry in frequency selective surfaces. Three structures with different multifractal geometries have been proposed and analyzed. The first structure allowed the design of multiband structures with greater flexibility in controlling the resonant frequencies and bandwidth. The second structure provided a bandwidth increase even with the rising of the fractal level. The third structure showed response with angle stability, dual polarization and provided room for a bandwidth increase with the rising of the structural multifractality. Furthermore, the proposed structures increased the degree of freedom in the multiband designs because they have multiple resonant frequencies ratios between adjacent bands and are easy to deploy. The validation of the proposed structures was initially verified through simulations in Ansoft Designer software and then the structures were constructed and the experimental results obtained

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The teaching profession is often associated with extensive workload inside and outside the classroom, poor teaching conditions, among other challenges that can cause sleep problems. These problems may be even greater in women, due to the professional and domestic work hours and to the major sleep necessity. Considering that sleeping problems may result from the practice of poor sleep habits, sleep education programs are conducted with the aim to reduce sleep deprivation, irregularity on sleep schedules, daytime sleepiness and improve sleep quality. In this sense, the objective of this study is to evaluate the influence of working hours, gender and a sleep education program on sleeping habits, quality of sleep, daytime sleepiness and the level of stress in teachers of elementary and secondary education. For that, teachers filled the questionnaires that assessed: 1. Sleeping habits (Sleep & Health), 2. Chronotype (Horne & Ostberg), 3. Daytime sleepiness (Epworth Sleepiness Scale), 4. Sleep Quality (Pittsburgh Sleep Quality Index), 5. Level of stress (The Inventory of Stress for Adults of Lipp) and 6. Daily pattern of sleep/wake cycle (Sleep Diary). The questionnaires 1, 4, 5 and 6 were repeated 3 weeks after the sleep education program. Teachers who begin work in the morning (7:11 ± 0:11 h) wake up earlier in the week and often have poor sleep quality compared to those who start in the afternoon (13:04 ± 00:12 h). Among those who begin work in the morning, the intermediate types and those with an evening tendency were more irregular in the wake up time than morning types and increased sleep duration on weekend. In relation to gender, women had longer sleep duration than men, although the majority presented excessive daytime sleepiness and poor sleep quality. However, when work schedule and age are similar between genders, the difference in sleep duration becomes a tendency and the difference in the percentage of excessive daytime sleepiness disappears, but the poor sleep quality persists in women. With respect to teachers who have gone through the sleep education program, there was an increase in knowledge about the subject, which may have contributed to the reduction in the frequency of coffee consumption close to bedtime and to the sleep quality improved in 18 % of participants. In the control group, there were random differences in knowledge in 3rd stage, and sleep quality improved in only 9% of teachers. The participation in the sleep education program was not enough to change the hours of sleep and decrease stress of teachers. Therefore, the start time school in the morning was preponderant in determining the wake up time of teachers, especially for intermediates types and those with an evening tendency. Furthermore, the poor quality of sleep was more common in women, and the sleep education program contributed to increase knowledge on the subject and to improve sleep quality.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The concept analysis process carefully examines the description and uses of a word or term, enabling the standardization of language, in addition to providing representation to the profession, and facilitate the work of taxonomies. The aim of the study was to analyze the concept of nursing diagnosis ineffective self-health in patients undergoing hemodialysis. Study concept analysis, based on Walker and Avant model and operationalized through integrative literature review. The databases searched were: SCOPUS, CINAHL, PUBMED, LILACS and COCHRANE, with descriptors: Selfmanagement, Adherence and Hemodialysis. The inclusion criteria were: articles published in the last five years, complete articles are available free in selected databases; articles available in Portuguese, English or Spanish; and articles that address the self-concept of health, the antecedents and the consequent. And Exclusion: editorials, letters to the editor, theses and dissertations. The survey of the articles occurred in the months from January to March 2014. The initial sample of 16785 articles, with 11748 in PUBMED, 4767 in Scopus, 174 in CINAHL, the Cochrane 70 and 26 in LILACS. After applying the criteria, 76 articles were selected, 19 in CINAHL, 18 in PUBMED, 30 in Scopus, and 9 in LILACS. In analyzing the data, given that the concept was sought in the literature was self-health, was held interpretation to ineffective self-health diagnosis through the transposition in the denial of the attributes, antecedents and consequences identified. It is noteworthy that the terms identified in the literature as defining characteristics and related factors of the diagnosis under study were added to the survey, not even the transposition into opposite term is possible. The results show that the concept developed for the inefficient self-health diagnosis was: the patient's inability to control habits and achieve the negotiated with professionals therapeutic targets, resulting in health complications. 33 antecedents relating to social, psychological and therapeutic aspects and 16 consequential, involving physiological, social, psychological and therapeutic aspects were identified. Thus, it is concluded that the ineffective self-health concept is broad and involves individual patient factors and the therapeutic relationship between patient and professionals. It is believed that the study contributed to the improvement of diagnosis in renal clientele, besides being an important base for the growth of the scientific body of nursing, subsidizing the development of own technology area

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The city of Natal has a significant daylight availability, although it use isn’t systematically explored in schools architecture. In this context, this research aims to determine procedures for the analysis of the daylight performance in school design in Natal-RN. The method of analysis is divided in Visible Sky Factor (VSF), simulating and analyzing the results. The annual variation of the daylight behavior requires the adoption of dynamic simulation as data procedure. The classrooms were modelled in SketchUp, simulated in Daysim program and the results were assessed by means of spreadsheets in Microsoft Excel. The classrooms dimensions are 7.20mx 7.20m, with windows-to-wall-ratio (WWR) of 20%, 40% and 50%, and with different shading devices, such as standard horizontal overhang, sloped overhang, standard horizontal overhang with side view protection, standard horizontal overhang with a dropped edge, standard horizontal overhang with three horizontal louvers, double standard horizontal overhang, double standard horizontal overhang with three horizontal louvers, plus the use of shelf light in half the models with WWR of 40% and 50%. The data was organized in spreadsheets, with two intervals of UDI: between 300lux and 2000 lux and between 300lux and 3000lux. The simulation was performed with the weather file of 2009 to the city of NatalRN. The graphical outputs are illuminance curves, isolines of UDI among 300lux and 2000 lux and tables with index of occurrences of glare and to an UDI among 300lux 3000lux. The best UDI300-2000lux performance was evidenced to: Phase 1 (models with WWR of 20%), Phase 2 (models with WWR of 40% and 50% with light shelf). The best UDI300-3000lux performance was evidenced to: Phase 1 (models with WWR of 20% and 40% with light shelf) and Phase 2 (models with WWR of 40% and 50% with light shelf). The outputs prove that the daylight quality mainly depends on the shading system efficacy to avoid the glare occurrence, which determines the daylight discomfort. The bioclimatic recommendations of big openings with partial shading (with an opening with direct sunlight) resulted in illuminances level higher than the acceptable upper threshold. The improvement of the shading system percentage (from 73% to 91%) in medium-size of openings (WWR 40% and 50%) reduced or eliminate the glare occurrence without compromising the daylight zone depth (7.20m). The passive zone was determined for classrooms with satisfactory daylight performance, it was calculated the daylight zone depth rule-of-thumb with the ratio between daylight zone depth and the height of the window for different size of openings. The ratio ranged from 1.54 to 2.57 for WWR of 20%, 40% and 50% respectively. There was a reduction or elimination of glare in the passive area with light shelf, or with awning window shading.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The conventional control schemes applied to Shunt Active Power Filters (SAPF) are Harmonic extractor-based strategies (HEBSs) because their effectiveness depends on how quickly and accurately the harmonic components of the nonlinear loads are identified. The SAPF can be also implemented without the use of the load harmonic extractors. In this case, the harmonic compensating term is obtained from the system active power balance. These systems can be considered as balanced-energy-based schemes (BEBSs) and their performance depends on how fast the system reaches the equilibrium state. In this case, the phase currents of the power grid are indirectly regulated by double sequence controllers with two degrees of freedom, where the internal model principle is employed to avoid reference frame transformation. Additionally the DSC controller presents robustness when the SAPF is operating under unbalanced conditions. Furthermore, SAPF implemented without harmonic detection schemes compensate simultaneously harmonic distortion and reactive power of the load. Their compensation capabilities, however, are limited by the SAPF power converter rating. Such a restriction can be minimized if the level of the reactive power correction is managed. In this work an estimation scheme for determining the filter currents is introduced to manage the compensation of reactive power. Experimental results are shown for demonstrating the performance of the proposed SAPF system.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This dissertation deals with the use of extended techniques for the saxophone in the piece Minus (for solo saxophone in Bb), composed through a composer-performer collaboration between Agamenon de Morais and the saxophonist Kleber Dessoles. The text is organized in the following manner: the first part brings the historical background of the concert music written for the saxophone since the beginning of the 20th-century, exploring the use of extended tehcniques and the main characters and historical facts of this period, with data obtained through a literature review; the second part deals with the issue of the composer-performer collaboration, since cases documented in the 18th and 19th centuries until nowadays, exploring in which different ways collaborations may happen and the motivations behind them; the third and final part is about the specific work, followed by a detailed description of the collaboration between the composer and the interpreter, as well as detailed explanations about the extended techniques present in the work (multiphonics and flatterzunge), through bibliographic and documental research, as well as descriptions of the meetings between composer and interpreter. At the end of the collaborative process, one may say that the final result was created from a sum of the composer's knowledge with the interpreter's, almost as if the composition had double authorship. The document describing this process may help composers and interpreters in composing for the saxophone, as well as guide future collaborative experiences.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

During over seven decades of institutionalizing the national heritage protection legal instrument it can be noticed the many ways of the instrument application, according to the approaches that were assigned to the spaces with heritage values and the dynamic of the elaborated thoughts within this theme. For the application of the instrument effectively, there is a long process that is carried out. This process begins with the study elaboration that aims to subsidize and justify the motivation of property protection, as well as the proposal of buffer zones and national protection areas delimitations, completing the process with the denial of the request or with the publication of the definitive national protection area at the Official Gazette. Starting with the relation between the existing heritage values identification into the historical centres and the definition of its protection areas that the area management will be done, based as well into the management intervention norms established for the protection area perimeter. From this context, the present essay has as porpoise to discuss the approach used for the identification and selection of a historical centre liable for national protection and the repercussion of this identification into the national protection area the was established, using a case study of the national protection of the historical centre of the city of Natal. Starting from the assumption that there are inconsistences and distortions about the text speech of the written document and the spatial delimitation of this document, motivated by an area that privileges the edifications rather than the urban space. Beginning with the urban history methodology, we are based on the precepts of Rossi (2011), Lamas (2010) and Cullen (2009) for that space reading, along with what Sant’Anna (2004) defines as “city-document” to make a new reading of this “heritage value space” verifying if the proposed protection area reflects what is defined as motivation for the national protection area process during the recognizing process. Therefore, it is concluded that it is essential that the buffer zones and the national protection areas are aligned with the text presented at the national protection area instruction, so the norms and criteria definition management process are established. We highlight that a site management and the identified values protection become very difficult without a specific law that beacon the decisions that should be taken.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Generation systems, using renewable sources, are becoming increasingly popular due to the need for increased use of electricity. Currently, renewables sources have a role to cooperate with conventional generation, due to the system limitation in delivering the required power, the need for reduction of unwanted effects from sources that use fossil fuels (pollution) and the difficulty of building new transmission and/or distribution lines. This cooperation takes place through distributed generation. Therefore, this work proposes a control strategy for the interconnection of a PV (Photovoltaic) system generation distributed with a three-phase power grid through a connection filter the type LCL. The compensation of power quality at point of common coupling (PCC) is performed ensuring that the mains supply or consume only active power and that his currents have low distorcion. Unlike traditional techniques which require schemes for harmonic detection, the technique performs the harmonic compensation without the use of this schemes, controlling the output currents of the system in an indirect way. So that there is effective control of the DC (Direct Current) bus voltage is used the robust controller mode dual DSMPI (Dual-Sliding Mode-Proportional Integral), that behaves as a sliding mode controller SM-PI (Sliding Mode-Proportional Integral) during the transition and like a conventional PI (Proportional Integral) in the steady-state. For control of current is used to repetitive control strategy, which are used double sequence controllers (DSC) tuned to the fundamental component, the fifth and seventh harmonic. The output phase current are aligned with the phase angle of the utility voltage vector obtained from the use of a SRF-PLL (Synchronous Reference Frame Phase-Locked-Loop). In order to obtain the maximum power from the PV array is used a MPPT (Maximum Power Point Tracking) algorithm without the need for adding sensors. Experimental results are presented to demonstrate the effectiveness of the proposed control system.