Flux Estimation
Mostrando 13-24 de 50 artigos, teses e dissertações.
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13. Development of the Part Heat Plate Method to Estimate Simultaneously Thermal Properties without Heat Flux Transducer / Desenvolvimento do método de aquecimento plano parcial para a determinação simultânea de propriedades térmicas sem o uso de transdutores de fluxo de calor
Desenvolve-se, neste trabalho, uma técnica experimental que permite a obtenção da difusividade e da condutividade térmica de materiais condutores e não condutores através do uso de elementos de aquecimento e de técnicas de estimativas de funções para a obtenção do fluxo de calor imposto. O princípio básico do procedimento é dividido em: i) dese
Publicado em: 2008
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14. Desenvolvimento de um atuador magnetico para excitação sem contato de sistemas rotativos / A magnetic actuator development for contactless excitation in rotor systems
A magnetic actuator as excitation source in rotating systems is developed, in order to accomplish modal analysis and other studies involving contacless excitation. Although the use of magnetic systems to apply forces onto rotating machinery has been carried out with high performance level (for example, magnetic bearings), the development of a conveniently ea
Publicado em: 2008
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15. Experimental performance evaluation of magnetic actuator used in rotating machinery analysis
A magnetic actuator as excitation source in rotative systems is proposed, in order to accomplish modal analysis without contact between the actuator and the rotor. Although the use of electromagnets for applying forces to rotating machinery have been carried out with high performance level (for example, magnetic bearings), the development of a conveniently e
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2007-03
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16. Estudo comparativo de técnicas de estimativa do fluxo estatórico de MIT
This work shows and compares three different flux estimator algorithms developed for use in high-performance sensorless ac motor drives. The first algorithm uses a low pass filter with a very low cut off frequency to integrate the back electromotive force (emf). The second one uses a high pass filter to remove the offset present in the signal before its inte
Publicado em: 2007
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17. Algoritmo preditivo baseado em modelo aplicado ao controle de velocidade do motor de indução / Speed control of induction motor using predictive algorithm
This thesis presents the results concerning the control of rotor flux and speed of the induction motor using MBPC strategy, which is based on the error minimization between the future set point and model prediction, resulting in control signals. In the case studied in this thesis the motor model is described in space-state. The non linear MBPC emploies searc
Publicado em: 2007
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18. Controle vetorial de velocidade de uma máquina de indução sem mancais trifásica com bobinado dividido utilizando estimação neural de fluxo / Vector Speed Control for a Three-Phase Bearingless Induction Machine with Divided Winding using Neural Flux Estimation
Este trabalho descreve o estudo e a implementação do controle vetorial de velocidade de uma máquina de indução sem mancais trifásica com bobinado dividido de 4 pólos e 1.1kW utilizando estimação neural de fluxo do rotor. O controle vetorial de velocidade opera em conjunto com os controles de posicionamento radial e das correntes nos enrolamentos de
Publicado em: 2007
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19. Investigation of gravity wave momentum fluxes in the upper atmosphere derived from airlow / Investigação do fluxo de momento das ondas de gravidade na alta atmosfera através da aeroluminescência
In this study, momentum fluxes due to gravity wave propagation into the MLT region was calculated by using airglow image data and theoretical modeling. Airglow O(1S) 557,7, O2(0-1,b) and OH NIR images were obtained from Cachoeira Paulista (22,7°S; 45,0°W) and São João do Cariri (7,4°S; 36,6°W) and processed for estimation of gravity wave intrinsic para
Publicado em: 2007
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20. The Brazilian agroexport sector and the foreign direct investment in the MERCOSUL/UE integration context / O setor agroexportador brasileiro e os investimentos diretos externos no contexto da integração MERCOSUL/UE
Having the constitution perspective of MERCOSUL/UE agreement with the possibility of the business strength between the blocks, we analized by the creation esteem and the business detour to the Brazilian agroexport sector the possible gains in four alternative sceneries of integration. It was used a model of partial balance, which the results to the four leve
Publicado em: 2006
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21. Identificação on-line de motores de indução através de modelo discreto para sinais senoidais
In this work are developed two on-line identification methods for three-phase induction motors based on discrete models obtained when we consider continuous systems excited by sinusoidal signals. The first method uses the discrete model of the homopolar machine in the stationary frame to estimate the stator resistance and the stator dispersion inductance and
Publicado em: 2006
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22. Balanço de radiação, energia e fluxo de CO2 em ecossistema de manguezal na Amazônia / Radiation and energy balance and fluxes of CO2 in a Amazon mangrove ecosystem
This work use the longest series of continuous meteorological data and fluxes measurements of CO2, sensible heat and latent heat made in Amazon mangrove ecosystem. The series used in this study corresponds to the period of November, 2002 to August, 2003. The meteorological data were collected using an EDISOL system based on the hedí covariance technique. Th
Publicado em: 2006
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23. Um estudo de estimativa de fluxo e conjugado em motores de indução trifásicos implementação utilizando DSP
This work presents a study and implementation of a torque estimator for three phase induction motors. Estimation is made from input voltages and currents and stator phase resistance is the only motor parameter needed. Torque estimation is obtained from stator flux estimation. This requires the integration of the phase counter electromotive force. An integrat
Publicado em: 2005
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24. INVERSE PROBLEM IN ATMOSPHERIC PHISICS / PROBLEMAS INVERSOS EM FÍSICA DA ATMOSFERA
Techniques for estimating unknown terms - such as eddy diffusivity and counter-gradient - in atmospheric flow are presented in this study. The methos is also used to identify the source term in atmospheric pollution. The scheme adopted is based on inverse problem methodology. The inverse problem is formulated as a non-linear optimization problem, where the o
Publicado em: 2005