Made available in DSpace on 2017-07-24T19:22:01Z (GMT). No. of bitstreams: 1 Camilo Andres P Mora.pdf: 2179325 bytes, checksum: 956a5f1d8568fa3876b0879ad21942c4 (MD5) Previous issue date: 2014-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to investigate the shrinkage-strainand degree of conversion inside the rootcanal"in situ"of resin cements used to lute fiber posts (Whitepost DC, FG). Thirty maxillary canines with similar root length average were selected (14 mm ± 1 mm). Each root canal was treated with crown-down technique and filled with gutta-percha, leaving 4 mm of apical seal.One week later, the roots were prepared following fiber post system manufacturer’s instructions. For the cementation, teeth were randomly divided into 2 groups (n = 15) according to the resin cement used: Group 1: dual-cured resin cement RelyX™ ARC – Adper Scotchbond™ Multipurpose Plus Adhesive (3M/ESPE) and Group 2: dual-cured resin cement RelyX™ U200 (3M/ESPE). Two fiber optic sensors with recorded Bragg gratings were attached to the coronal section (not in contact with the root) of each post before inserting the resin cement inside the root canal. These sensors measured the deformations of the cement over the coronal and apical section of the root (μe). Once measured, the specimens were sectionated in order to obtain slides on its cervical and apical sections. The degree of conversion of the cements on each third was analyzed by μ-Raman micro-spectroscopy. The data were statitsticallyanalyzed by two-way ANOVA (p = 0.05). The dual-curedconventional resin cement tested in this study showed the highest values of shrinkage-strain and degree of conversion; cervical region showed higher values than apical region in both of resin cements. / O objetivo deste estudo foi conhecer o comportamento e a magnitude das deformações que ocorrem durante a polimerização “in loco” no interior do canal radicular, em cimentos resinosos durante a fixação de pinos de fibra de vidro Whitepost DC (FGM) e verificar o grau de conversão dos mesmos. Foram selecionados 30 caninos superiores (n=10) com comprimento radicular médio de 14 mm medidos da junção cemento-esmalte (JCE). Os canais foram tratados endodonticamente ea guta-percha foi removida deixando 4 mm do selamento apical. Após uma semana os canais foram preparados. Para a cimentação, os dentes foram divididos aleatoriamente em 2 grupos, segundo o cimento resinoso utilizado: Grupo ARC: cimento resinoso dual RelyX™ ARC – Adesivo Adper Scotchbond™ Multipurpose Plus (3M/ESPE) e Grupo U200: cimento resinoso dual RelyX™ U200 (3M/ESPE). Antes da inserção do cimento resinoso no interior do canal radicular foram posicionados no pino dois sensores de fibra óptica com redes de Bragg gravadas e colados na região que não entrou em contato com as paredes do canal; um na posição mais apical e outro na mais cervical do pino. Os sensores realizaram a mensuração das deformações do cimento em uma porção coronária e apical do canal radicular, para se obter valores em micro-strain (μe). Logo depois, os espécimes foram cortados em fatias para mensuração do grau de conversão dos cimentos, nos terços apical e cervical por meio da espectroscopia μ-Raman. Os dados obtidos foram analisados estatisticamente por meio do teste ANOVA de dois fatores (p=0,05).Os sensores de fibra óptica com redes de Bragg mostraram-se eficientes na mensuração de contração de polimerização de cimentos resinosos. O cimento resinoso convencional testado no estudoapresentou maiores valores de contração de polimerização e grau de conversão, quando comparado com o cimento resinoso autoadesivo. O terço cervical apresentou maiores valores de contração de polimerização e grau de conversão, quando comparado com o terço apical independentedo tipo de cimento.

Ce travail de thèse présente une étude théorique, numérique et expérimentale de l’intégration sur un guide d’onde diélectrique de chaînes de nanoparticules d’or supportant des résonances « plasmon de surface localisé ». Les guides d’onde à plasmon de surface localisé procurent un confinement sub-longueur d’onde de la lumière, ce qui permet d’envisager la réalisation de composants optiques ultra-compacts. Cependant, leurs pertes optiques élevées restreignent leur application à de courtes distances de propagation, contrairement aux guides d’onde diélectriques. Une combinaison judicieuse des deux types de guide doit donc permettre de bénéficier de leurs avantages respectifs. Dans un premier temps, nous avons étudié théoriquement les propriétés des chaînes des nanoparticules grâce à un modèle analytique basé sur l’approximation de dipôles ponctuels couplés, que nous avons développé. Cette étude a permis de déterminer la forme et les dimensions des nanoparticules qui ont ensuite été introduites dans un logiciel de FDTD pour simuler le couplage entre la chaîne de nanoparticules et le guide diélectrique (SOI ou en Si3N4). De cette étude numérique, nous avons déduit les géométries des structures à fabriquer. Les structures réalisées ont été caractérisées à l’aide d’un banc de transmission résolue spectralement, mis en place pendant cette thèse, et d’un système de mesures en champ proche optique en collaboration avec le LNIO (Troyes). Pour la première fois, nous avons montré expérimentalement les propriétés d’une chaîne courte de nanoparticules intégrée sur un guide SOI, ainsi que le phénomène de guides couplés entre une chaîne longue de nanoparticules et un guide SOI. Une valeur record de la constante de couplage a été obtenue, et ce, aux longueurs d’onde des télécoms (proche infrarouge). L’énergie lumineuse transportée par le mode TE du guide SOI peut ainsi être entièrement transférée au guide plasmonique en 4 ou 5 nanoparticules, soit une distance de propagation de moins de 600 nm. Nous avons également étudié les propriétés de réseaux de Bragg à base de plasmon de surface localisé en confrontant les résultats de mesures de transmission résolue spectralement aux résultats théoriques d’un modèle analytique basé à la fois sur l’approximation de dipôle ponctuel en régime quasi-statique et la théorie des modes couplés. Ces travaux ouvrent la voie à des applications de pinces optiques, de capteurs ou de spaser, qui bénéficieront de l’intégration de nanoparticules métalliques dans les circuits photoniques. / This PhD work presents a theoretical, numerical and experimental study of the integration of a gold nanoparticle chain supporting "localized surface plasmon resonances" on a dielectric waveguide. The localized surface plasmon allows a sub-wavelength confinement of light which could lead to the achievement of ultra-compact optical components. However, the high level of optical losses restricts their application to short propagating distances unlike dielectric waveguides. A judicious combination of both types of guides should therefore allow taking profit of their respective advantages. Firstly, we have theoretically studied the properties of nanoparticles chains using an analytical model that we have developed following the coupled dipoles approximation. This has helped us to determine the shape and size of nanoparticles, which have been further used in a FDTD software, to simulate the coupling between the chain and the dielectric waveguide (SOI or Si3N4). Using this numerical study, we have deduced the geometries of structures to be fabricated. The realized structures have been characterized using a spectrally resolved transmission set-up, built during this thesis, and an optical near field measurement set-up (collaboration LNIO Troyes). For the first time, we have experimentally shown the properties of short nanoparticle chains integrated on a SOI waveguide as well as the existence of a coupled waveguide phenomenon between long nanoparticle chains and SOI waveguides. A record value has been obtained for the coupling constant at telecom wavelengths (near infrared). The light energy carried by the TE mode of the SOI waveguide can be completely transferred into the plasmonic waveguide via the first 4 or 5 nanoparticles of the chain, which means a distance of less than 600 nm. We have also studied the properties of Bragg gratings based on localized surface plasmon. Experimental results from spectrally resolved transmission measurements have been compared to theoretical results obtained from an analytical model based on the point dipole approximation in quasi-static regime, on one hand, and using the coupled mode theory, on the other hand. This work opens the way for applications to optical tweezers, sensors or spasers, which will benefit from the integration of metal nanoparticles in photonic circuits.

Optical fiber sensors have already been developed from the experimental stage to practical applications in the past 20 years. There is no doubt that this technology can bring a wealth of applications, ranging from sensors in medical industry, aerospace and wind-energy industries, through to distributed sensors in oil and gas industry. Among a large amount of physical and chemical parameters which optical fiber sensors could measure, temperature and strain are the most widely studied. This thesis presents several low-cost optical fiber sensor configurations primarily for temperature and strain measurement. Several basic optical fiber components which are good candidates as optical fiber sensors are used in our experiments, such as fiber Bragg gratings (FBGs), multimode fibers (MMFs), small-core dispersion compensation fibers (SCDCFs), high-birefringence fiber loop mirrors (HBFLMs), and polarization-maintaining photonic crystal fibers (PMPCFs). Temperature and strain cross sensitivity is a crucial issue when designing high performance optical fiber sensors, since most of the sensing components are both sensitive to temperature and strain. This would introduce an error when measuring each of them independently. We developed several schemes to overcome this problem by cascading an FBG and a section of MMF, inserting an FBG into an HBFLM, and space division multiplexing two HBFLMs. By measuring the wavelength shifts of the two independent components' spectra in each scheme, simultaneous measurement of temperature and strain could be achieved. However, all the above schemes need optical spectrum analyzers to monitor the spectral information, which increases the cost of the system and limits the operation speed. In order to avoid using optical spectrum analyzers, we use an intensity-based interrogation method with MMFs and HBFLMs as edge filters. By measuring power ratio changes, instead of monitoring spectra shifts, simultaneous measurement of temperature and strain could be realized with a low cost and high speed. The resolutions of the above five configurations are between 0.26 - 1.2 ^oC in temperature and 9.21 - 29.5 με in strain, which are sufficient for certain applications. We also investigate the sensing applications with the SCDCF. Since the cutoff wavelength of this kind of fiber is around 1663 nm, which makes it naturally an MMF in the wavelength range of 1550 nm. By slightly offsetting the core of the SCDCF with respect to that of the standard single-mode fiber (SMF), a high extinction ratio could be achieved with almost 9 dB. When a lateral force (lateral strain) applied on the SCDCF, extinction ratio will decrease. The change of the extinction ratio is almost independent of temperature variation. The measured extinction ratio change has a good quadratic relationship with respect to applied lateral force. This feature could be used to measure lateral force (lateral strain). In addition, we also use this feature to realize simultaneous measurement of both the longitudinal strain and lateral strain, since the applied longitudinal strain results in the whole spectrum shift. Moreover, a miniature high temperature sensor could also be made using the SCDCF. One end of a 4-mm long SCDCF is spliced directly to SMF with the other end cleaved. By monitoring the reflection spectrum of the SCDCF, temperature information could be obtained. This sensing head is very compact and could realize high temperature measurement up to 600 ^oC. Recently, a kind of PMPCF has been found to have very small responses to temperature change. This offers an opportunity to measure other parameters without considering temperature influence. We construct a compact 7-mm long transmission-type sensor with this kind of PMPCF. The interference spectrum generated by the coupling of cladding modes and core mode is obtained by slightly offsetting the PMPCF core to SMF core. The experiment shows that the interference spectrum is almost unchanged within the temperature range of 25-60 ^oC. The presented sensor has the potential to be used to measure strain and refractive index in the normal environment without temperature discrimination for practical applications.

<p>This thesis discusses a new scheme for generating radiation in the mid infrared spectral region, especially the 3.5-5 µm range. The scheme uses established Nd³⁺-lasers at 1.06 µm and down conversion in nonlinear optical crystals. The down conversion is made by two optical parametric oscillators (OPO) in series. The second OPO is a classical OPO using a zink germanium phosphide (ZGP) crystal. ZGP is the best nonlinear material available for the 4-8 µm spectral range, but it is absorbing below 2 µm. The new development presented in this thesis is the OPO used to convert the 1.06 µm laser radiation to a suitable OPO pump near 2 µm.</p><p>The OPO uses a type I quasi phase-matched crystal, which accesses high nonlinearities and avoids walk-off. The problem with type I OPOs close to degeneracy is the broad bandwidth of the generated radiation, which reduces the efficiency of a second OPO. This has been solved with a spectrally selective cavity using a volume Bragg grating output coupler. Unlike other bandwidth limiting schemes this introduces no intracavity losses and thus efficient OPO operation is achievable.</p><p>Narrow linewidth (~0.5 nm) OPO operation has been achieved with periodically poled LiNbO₃ (PPLN) and periodically poled KTiOPO4 (PPKTP) while locking the signal wavelength at 2008 nm and simultaneously generating an idler at 2264 nm. A high average power PPLN OPO with 36 % conversion efficiency and 47 % slope efficiency is reported. Operation very close to degeneracy at 2128 nm with the narrowband signal and idler peaks separated by 0.6 nm was demonstrated in a PPKTP OPO. Both the signal at 2008 nm and the combined signal and idler around 2128 nm from the PPKTP OPOs have been used to show efficient pumping of a ZGP OPO. The maximum conversion efficiency from 1 µm to the mid-IR demonstrated is 7 % with a slope efficiency of 10 %. This is not quite as high as what has been presented by other authors, but the experiments reported here have not shown the optimum efficiency of the new scheme. Relatively simple improvements are expected to give a significant increase in conversion efficiency.</p>

Optical fiber sensors have already been developed from the experimental stage to practical applications in the past 20 years. There is no doubt that this technology can bring a wealth of applications, ranging from sensors in medical industry, aerospace and wind-energy industries, through to distributed sensors in oil and gas industry. Among a large amount of physical and chemical parameters which optical fiber sensors could measure, temperature and strain are the most widely studied. This thesis presents several low-cost optical fiber sensor configurations primarily for temperature and strain measurement. Several basic optical fiber components which are good candidates as optical fiber sensors are used in our experiments, such as fiber Bragg gratings (FBGs), multimode fibers (MMFs), small-core dispersion compensation fibers (SCDCFs), high-birefringence fiber loop mirrors (HBFLMs), and polarization-maintaining photonic crystal fibers (PMPCFs). Temperature and strain cross sensitivity is a crucial issue when designing high performance optical fiber sensors, since most of the sensing components are both sensitive to temperature and strain. This would introduce an error when measuring each of them independently. We developed several schemes to overcome this problem by cascading an FBG and a section of MMF, inserting an FBG into an HBFLM, and space division multiplexing two HBFLMs. By measuring the wavelength shifts of the two independent components' spectra in each scheme, simultaneous measurement of temperature and strain could be achieved. However, all the above schemes need optical spectrum analyzers to monitor the spectral information, which increases the cost of the system and limits the operation speed. In order to avoid using optical spectrum analyzers, we use an intensity-based interrogation method with MMFs and HBFLMs as edge filters. By measuring power ratio changes, instead of monitoring spectra shifts, simultaneous measurement of temperature and strain could be realized with a low cost and high speed. The resolutions of the above five configurations are between 0.26 - 1.2 ^oC in temperature and 9.21 - 29.5 με in strain, which are sufficient for certain applications. We also investigate the sensing applications with the SCDCF. Since the cutoff wavelength of this kind of fiber is around 1663 nm, which makes it naturally an MMF in the wavelength range of 1550 nm. By slightly offsetting the core of the SCDCF with respect to that of the standard single-mode fiber (SMF), a high extinction ratio could be achieved with almost 9 dB. When a lateral force (lateral strain) applied on the SCDCF, extinction ratio will decrease. The change of the extinction ratio is almost independent of temperature variation. The measured extinction ratio change has a good quadratic relationship with respect to applied lateral force. This feature could be used to measure lateral force (lateral strain). In addition, we also use this feature to realize simultaneous measurement of both the longitudinal strain and lateral strain, since the applied longitudinal strain results in the whole spectrum shift. Moreover, a miniature high temperature sensor could also be made using the SCDCF. One end of a 4-mm long SCDCF is spliced directly to SMF with the other end cleaved. By monitoring the reflection spectrum of the SCDCF, temperature information could be obtained. This sensing head is very compact and could realize high temperature measurement up to 600 ^oC. Recently, a kind of PMPCF has been found to have very small responses to temperature change. This offers an opportunity to measure other parameters without considering temperature influence. We construct a compact 7-mm long transmission-type sensor with this kind of PMPCF. The interference spectrum generated by the coupling of cladding modes and core mode is obtained by slightly offsetting the PMPCF core to SMF core. The experiment shows that the interference spectrum is almost unchanged within the temperature range of 25-60 ^oC. The presented sensor has the potential to be used to measure strain and refractive index in the normal environment without temperature discrimination for practical applications.

CNPq / Esta dissertação descreve a fabricação, aplicação e os resultados de um sensor de fibra ótica baseada em redes de Bragg regeneradas para a medição de elevadas temperaturas dos gases de exaustão em uma turbina de motor diesel de locomotiva. É proposto um encapsulamento para a FBG com peças em aço inoxidável o qual foi fixado na superfície da turbina. O sensor foi posto a prova sendo submetido em testes em campo variando a potência do motor. Em laboratório foi feita a comparação do sensor ótico com um sensor convencional termopar. Foi possível demonstrar que os valores de temperatura medidos pelos sensores, tanto o sensor a fibra ótica quanto o convencional, seguem a mesma tendência da potência gerada pelo motor e, dessa forma, foi demonstrado a eficiência do funcionamento dos sensores mostrando a medição de temperaturas na turbina. / This paper describes the fabrication, implementation and results of a fiber optic sensor based on Bragg gratings regenerated for measurement of high temperatures of the exhaust gases in a turbine diesel engine locomotive. The proposed sensor with an encapsulation with stainless steel parts which is laid down on the surface of the turbine. The sensor has been challenged undergoing field tests at varying engine power. In the laboratory the optical sensor was compared with a conventional thermocouple sensor. It was possible to demonstrate that the temperature values measured by the sensors, both the optical fiber sensor as the conventional follow the same trend of the power generated by the engine and thus demonstrated the efficiency of the operation of sensors measuring temperatures showing in turbine.

Este trabalho tem como objetivo compreender o comportamento térmico da excitatriz estática da Usina Hidrelétrica Derivação do Rio Jordão (UHEDRJ), empregando redes de Bragg em fibra ótica como sensor de temperatura. São apresentados os componentes da excitatriz estática, com foco na ponte retificadora trifásica controlada a tiristores. Com a calibração pôde-se conhecer os erros e incertezas dos sensores, tendo as maiores contribuições de incerteza devidas à dispersão das amostras e ajuste das curvas pelo método dos mínimos quadrados. A instrumentação da excitatriz estática permite que sejam realizados ensaios em diversas condições de operação da unidade geradora: partida da unidade, excitação a vazio, ou seja, com o gerador energizado, mas sem estar conectado ao sistema elétrico; excitada e sincronizada, ou seja, gerador energizado e sincronizado com o sistema elétrico; rampa de carga até a carga nominal e parada da unidade. Os ensaios realizados permitem estimar o comportamento térmico da ponte retificadora, variações de temperatura de cada tiristor no painel e como ocorrem as dissipações térmicas. / This work aims to study the static exciter thermal behavior of the hydroelectric power plant Rio Jordão (UHEDRJ) using fiber Bragg gratings as temperature sensor. The components of the static exciter are presented, with a focus on three-phase thyristor controlled bridge rectifier. The calibration allows knowing the errors and uncertainties of the sensors and the greatest uncertainty contributions due to dispersion of the samples and adjusting the curves by the method of minimun squares. The static exciter instrumentation allows performed the tests in various operating conditions of the generating unit: starting unit, excitation empty (with the generator energized but not connected to the grid); excited and synchronized (energized and synchronized with the power grid), ramp load to rated load and the unit stopped. The tests allow to estimate the thermal behavior of the bridge rectifier, temperature variations of each thyristor in the panel and how occur the thermal dissipation.

CAPES / Este trabalho tem como objetivo desenvolver um sensor a fibra óptica para a monitoração de temperatura em mancais de hidrogeradores de usinas hidrelétricas. Foi apresentado o projeto gráfico, modelagem térmica, processo de montagem e testes realizados. Por tratar-se de uma inovação, é difícil a comparação com outros sensores ópticos desenvolvidos especificamente para monitorar temperatura em mancais de hidro geradores. Inicialmente, foram realizados ensaios preliminares com um protótipo para determinação da dinâmica térmica no interior dos mancais em situações diversas de operação. A partir dessa medição, foi idealizado um sensor óptico que possui duas fibras ópticas, com 3 redes de Bragg gravadas em cada uma delas. Essas redes são encapsuladas por uma haste de alumina coberta com anéis de material com elevada condutividade térmica onde as redes de Bragg se localizam, e baixa condutividade térmica no restante da haste. O procedimento, para calibrar as redes de Bragg do sensor, consistiu em varias a temperatura em degraus de 10°C desde 10°C até 80°C. Cada valor de temperatura permaneceu estável durante 20min, permitindo que o comprimento de onda refletido de cada sensor pudesse ser estimado mediante um histograma. A partir da calibração foram determinados os coeficientes de correlação e o coeficiente de sensibilidade térmica de cada sensor, bem como a incerteza padrão combinada dos mesmos. As incertezas foram divididas em dois tipos, A e B. As incertezas do tipo A, são relativas à dispersão amostral e são determinadas a partir da média, variância e desvio padrão das amostras realizadas durante a calibração. As incertezas do tipo B são obtidas de manuais e certificados de calibração. Foram realizados testes em laboratório com o objetivo de submeter o novo sensor a grandes variações térmicas, entre 15°C e 75°C e checar se as incertezas determinadas correspondiam na prática. Os resultados obtidos apresentam erro máximo de aproximadamente 0,9°C entre o sensor óptico e o sensor de referência PT100. Esse resultado situa-se dentro da faixa de valores de incerteza calculada para os sensores da fibra óptica 1, respectivamente 1,7°C, 1°C e 0,7°C para os sensores 1, 2 e 3. Assim como para a fibra 2, foram observados os valores de incerteza de 0,98°C e 0,71°C respectivamente para as FBG 1, 2 e 3. O desenvolvimento deste sensor possibilita a criação de novos sistemas de monitoração de temperatura ópticos aplicáveis em geradores de grande porte, bem coma interligação destes sistemas visando no futuro o mapeamento térmico total de um gerador utilizando sensoriamento óptico. / This work aims to develop a fiber optic probe for temperature monitoring in bearings of generators hydro power plants. Graphic design, thermal modeling, assembly and testing process is presented. Once it is innovation, it is difficult to compare with other optical transducers developed specifically for monitoring temperature in bearing hydro generators. Initially experiments were performed with a prototype for determination of the thermal dynamics inside the bearings in various operating situations. From this measurement, an optical transducer was designed which was two optical fibers with 3 Bragg gratings recorded in each of them. These gratings are encapsulated by a rod made of alumina and covered with rings of material with good thermal conductivity where the Bragg grating is located, and low thermal conductivity in the remainder of the rod. The procedure for calibrating the Bragg gratings of the transducer consisted of steps of 10°C in the temperature range from 10°C to 80°C. Each temperature value remained stable during 20 min, allowing the mean wavelength reflected from each sensor might be estimated by a histogram. Were determined from the calibration the correlation coefficient and the coefficient of thermal sensitivity of each sensor, and the combined standard uncertainty thereof. The uncertainties were divided into two types: Type A uncertainties are related to the sample dispersion and are determined from the mean, variance and standard deviation of the samples taken during calibration, and type B where uncertainties are obtained from manuals and certificates of calibration. Tests were conducted in laboratory with the aim to submit the new transducer to large temperature variations, ranging between 15°C and 75°C and to check if the uncertainties corresponded in practice. The results presented the maximum error of about 0.9°C between the optical sensor and the reference sensor PT100. This result is within the range of uncertainty values calculated for the fiber optical fiber 2, uncertainty values of 0.98°C, 0.85°C to 0.71°C respectively for the FBG 1, 2 and 3 were observed. The development of this transducer enables the creation of new systems for monitoring temperature optical applicable in generators, as well as the interconnection of these systems to the future the total thermal mapping of a generator using optical sensing. / 5000

CNPq / Esta dissertação descreve a fabricação, aplicação e os resultados de um sensor de fibra ótica baseada em redes de Bragg regeneradas para a medição de elevadas temperaturas dos gases de exaustão em uma turbina de motor diesel de locomotiva. É proposto um encapsulamento para a FBG com peças em aço inoxidável o qual foi fixado na superfície da turbina. O sensor foi posto a prova sendo submetido em testes em campo variando a potência do motor. Em laboratório foi feita a comparação do sensor ótico com um sensor convencional termopar. Foi possível demonstrar que os valores de temperatura medidos pelos sensores, tanto o sensor a fibra ótica quanto o convencional, seguem a mesma tendência da potência gerada pelo motor e, dessa forma, foi demonstrado a eficiência do funcionamento dos sensores mostrando a medição de temperaturas na turbina. / This paper describes the fabrication, implementation and results of a fiber optic sensor based on Bragg gratings regenerated for measurement of high temperatures of the exhaust gases in a turbine diesel engine locomotive. The proposed sensor with an encapsulation with stainless steel parts which is laid down on the surface of the turbine. The sensor has been challenged undergoing field tests at varying engine power. In the laboratory the optical sensor was compared with a conventional thermocouple sensor. It was possible to demonstrate that the temperature values measured by the sensors, both the optical fiber sensor as the conventional follow the same trend of the power generated by the engine and thus demonstrated the efficiency of the operation of sensors measuring temperatures showing in turbine.

Este trabalho tem como objetivo compreender o comportamento térmico da excitatriz estática da Usina Hidrelétrica Derivação do Rio Jordão (UHEDRJ), empregando redes de Bragg em fibra ótica como sensor de temperatura. São apresentados os componentes da excitatriz estática, com foco na ponte retificadora trifásica controlada a tiristores. Com a calibração pôde-se conhecer os erros e incertezas dos sensores, tendo as maiores contribuições de incerteza devidas à dispersão das amostras e ajuste das curvas pelo método dos mínimos quadrados. A instrumentação da excitatriz estática permite que sejam realizados ensaios em diversas condições de operação da unidade geradora: partida da unidade, excitação a vazio, ou seja, com o gerador energizado, mas sem estar conectado ao sistema elétrico; excitada e sincronizada, ou seja, gerador energizado e sincronizado com o sistema elétrico; rampa de carga até a carga nominal e parada da unidade. Os ensaios realizados permitem estimar o comportamento térmico da ponte retificadora, variações de temperatura de cada tiristor no painel e como ocorrem as dissipações térmicas. / This work aims to study the static exciter thermal behavior of the hydroelectric power plant Rio Jordão (UHEDRJ) using fiber Bragg gratings as temperature sensor. The components of the static exciter are presented, with a focus on three-phase thyristor controlled bridge rectifier. The calibration allows knowing the errors and uncertainties of the sensors and the greatest uncertainty contributions due to dispersion of the samples and adjusting the curves by the method of minimun squares. The static exciter instrumentation allows performed the tests in various operating conditions of the generating unit: starting unit, excitation empty (with the generator energized but not connected to the grid); excited and synchronized (energized and synchronized with the power grid), ramp load to rated load and the unit stopped. The tests allow to estimate the thermal behavior of the bridge rectifier, temperature variations of each thyristor in the panel and how occur the thermal dissipation.