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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Desenvolvimento de uma ferramenta computacional para aplica??o em m?todos de eleva??o por bombeio centr?fugo submerso

Batista, Evellyne da Silva 26 September 2009 (has links)
Made available in DSpace on 2014-12-17T14:55:40Z (GMT). No. of bitstreams: 1 EvellyneSBpdf.pdf: 1159066 bytes, checksum: 300fe338752c295fd279c5c695b984a8 (MD5) Previous issue date: 2009-09-26 / Petr?leo Brasileiro SA - PETROBRAS / The Electrical Submersible Pump (ESP) has been one of the most appropriate solutions for lifting method in onshore and offshore applications. The typical features for this application are adverse temperature, viscosity fluids and gas environments. The difficulties in equipments maintenance and setup contributing to increasing costs of oil production in deep water, therefore, the optimization through automation can be a excellent approach for decrease costs and failures in subsurface equipment. This work describe a computer simulation related with the artificial lifting method ESP. This tool support the dynamic behavior of ESP approach, considering the source and electric energy transmission model for the motor, the electric motor model (including the thermal calculation), flow tubbing simulation, centrifugal pump behavior simulation with liquid nature effects and reservoir requirements. In addition, there are tri-dimensional animation for each ESP subsytem (transformer, motor, pump, seal, gas separator, command unit). This computer simulation propose a improvement for monitoring oil wells for maximization of well production. Currenty, the proprietaries simulators are based on specific equipments manufactures. Therefore, it is not possible simulation equipments of another manufactures. In the propose approach there are support for diverse kinds of manufactures equipments / Bombeio Centr?fugo Submerso (BCS) tem se mostrado uma das solu??es mais adequadas como m?todo de eleva??o em aplica??es onshore e offshore. As caracter?sticas t?picas desssas aplica??es s?o condi??es adversas de temperatura, fluidos viscosos e ambientes gaseificados. As dificuldades encontradas na manuten??o e instala??o de equipamentos s?o fatores que oneram a produ??o de petr?leo em ?guas profundas, com isso, a otimiza??o via automa??o, pode ser um passo fundamental para a redu??o de custos e falhas nos equipamentos de subsuperf?cie. Este trabalho apresenta um simulador computacional relacionado ao m?todo de eleva??o artificial BCS. A ferramenta representa o comportamento din?mico, considerando a transmiss?o de energia el?trica da superf?cie ao motor, modelo do motor el?trico (incluindo o efeito t?rmico), simula??o do escoamento na tubula??o, simula??o do comportamento da bomba centr?fuga, levando em considera??o os efeitos da natureza do l?quido e os aspectos do reservat?rio. Adicionalmente, s?o encontrados anima??es tridimensionais para cada subsistema BCS (transformador, motor, bomba, selo ou protetor, separador de g?s e quadro de comando). O simulador computacional prop?e uma melhoria no acompanhamento de po?os de petr?leo visando o aumento da produtividade do po?o. Atualmente, os simuladores comerciais est?o baseados em equipamentos espec?ficos do fabricante, dificultando obter resultados com outros equipamentos. Na t?cnica proposta, existe suporte para diversos fabricantes
12

Malý asynchronní motor zvláštního typu / Special small induction motor

Trubák, Vojtěch January 2018 (has links)
This term paper is focused on theory and calculation of an induction motor with solid rotor. It is divided into six chapters, the first one being an introduction and the last being a conclusion. Second chapter is dedicated to magnetism. There is briefly description of a skin depth of a conductor and calculation method for impedance of a conductive solid. Third chapter is focused on theory of an induction machines, their construction, equivalent circuit and some of their properties. Fourth chapter is dedicated to calculation of an induction motor with solid rotor and its parameters. Fifth chapter is comparing results of calculation done in fourth chapter for an already existing motor with measured values.
13

Zvýšení účinnosti jednofázového asynchronního motoru / Increase of efficiency of a single phase induction machine

Muczka, Vojtěch January 2018 (has links)
This thesis is dedicated to efficiency increase of one phase induction machine through material change of induction cage and rotor slot shape optimization under the condition of maintaining the same locked-rotor torque. In the first part of this thesis is the explanation of induction machine principles. Next is the comparison of measured and simulated parameters of small one phase machine from ATAS company. The following part is dedicated to the analysis of rotor slot shape and ring size influence on machine parameters when using pure aluminum instead of resistive alloy. The next chapter deals with slot shape optimization in the program RMxprt, controlled by genetic algorithm written in MATLAB interface. In the final part are the resultant slot shapes simulated in Ansys Maxwell using finite element method and then the measured, simulated and expected parameters are compared.
14

Vlastnosti asynchronního motoru napájeného z frekvenčního měniče / Induction motor powered from inverter

Fiala, Petr January 2016 (has links)
This master’s thesis studies additional losses generated in the induction motor powered from inverter. The first chapter was used for literature search and it mentions valuable publications. The second chapter discusses the different types of losses in the induction motor. The third chapter describes other negative effects on motor caused by inverter, the fourth one defines possible measuring methods, which would lead to the quantification of additional losses. The fifth chapter introduces the electromotor tested as well as the measuring instruments used. The last chapter presents pivotal results of the measurement in the testing room.
15

Výpočet chlazení asynchronního stroje pomocí programu Ansys CFX / Calculation of the cooling of the asynchronous machine ANSYS CFX

Horálek, Lukáš January 2017 (has links)
The issue this master’s thesis discusses the cooling synchronous machines. Specifically, the calculation of cooling induction motor using the finite volume method. Using Autodesk Inventor will create a 3D model of a real electric machine, ie asynchronous motor and then ANSYS WORKBENCH perform system analysis CFX, based on the finite volume method. Furthermore, we realize the air speed measurements on a particular machine and the individual results obtained by measuring and calculating the actual compared with each other. The master’s thesis also deals marginally with closely related to it. For the same machine model, we apply the calculation of the temperature fields using the finite volume method and them perform a thermal analysis. Next, we can carry out the measurement of the temperature on the motor itself and calculate the measured values and the measured compare each other.
16

Optimalizace tvaru drážek asynchronního motoru / Optimization of a small induction machine’s slots

Šišák, David January 2017 (has links)
This master thesis deals with optimization of the shape of the stator and rotor slots of induction motor with focusing on increasing efficiency. The theoretical part introduces the principles of optimization algorithms. Another part is devoted to design the shape of slots and its influence on the shape of slots on machine. On the models of motor was conducted the optimized shape of slots by using a genetic algorithm. Firstly, it was performed by using the analytical calculation in the RMxprt program, then by using the finite element method on two different models, whose difference simulates the influence of the production technology on the efficiency of the motor. Laboratory measurement was made on a real machine as well. The results of the measurement, calculations and optimizations are compared in the work.
17

Vliv frekvenčního měniče na životnost ložisek a jejich poškození / The influence of the frequency converter on the life and damage of bearings

Sukovatý, Adam January 2018 (has links)
This thesis deals with the effect of frequency inverter on the lifetime of roller bearings. The measurement has been carried out on the frequency inverter and induction motor by Siemens in the Switchgear laboratory of Fakulty of elektrical engineering and communication. Data has been recorded and processed on Adash VA4 Pro analyzer. Methods of measuring RMS values and frequency analysis of vibration and current were used for the analysis. Based on the mutual similarity of frequency spectrum, the presence of the high frequency capacitive current in the bearings has been proven. To prevent this, possible solutions have been presented. In the second part of the experiment an effect of changing pulse width modulation (PWM) on vibration was examined. The goal was to make a basic analysis and to provide background material for further research.
18

Studie využití měděných tyčí a soustředěného vinutí v asynchronním motoru / Study of concentrated winding induction motor

Trn, Ondřej January 2019 (has links)
This diploma thesis deals with the possibility of using a concentrated winding in an induction motor and the use of copper bars in a rotor cage. The first part of the thesis explains the basic theoretical knowledge of the operation and principle of the induction machine. In this theoretical part we will learn what is actually a concentrated winding and how it is placed on the stator. The second part is focused on the analytical design of the machine with classical distributed winding and with concentrated winding. The third theoretical part is an introduction to the issue of influencing the motor harmonics. The last final part of the thesis shows differences in operational properties of designed machines.
19

Identifikace parametrů asynchronního motoru / Identification of AC induction motor parameters

Křížek, Tomáš January 2008 (has links)
This thesis describes and realizes (in program Matlab/Simulink and in the microcontroller Freescale 56F8346) one off-line identification method of AC Induction motor parameters which are necessary to implement the field-oriented control strategy. The identification metod identify leakage inductance, magnetizing inductance and secondary time constants. The presented method is evaluted, advantages and disadvantages of this method are evaluated with reference to their possible use in real-machine. The experimental results and schemes which are presented demonstrate the feasibility methods. The thesis is dividend in seven chapters. Second chapter describes the basic principle and model AC induction motor. Third chapter generally describes identification methods. Fourth, fifth and sixth chapters deal with method which is based on a previous work of the authors [4] and [5].
20

Matematické modely transformátorů a asynchronních motorů / Mathematical models of the transformers and asynchronous machines

Cipín, Radoslav January 2008 (has links)
The fist part of this work is dealt with the construction of the mathematical models of voltage and current transformers. There are created and simulated models of voltage and current transformer with the nonlinear magnetization characteristics. The second part of this work is dealt with equivalent circuit of the induction motor in the form of Gamma-circuit. The speed-torque characteristic and the dependence of stator current on the slip are calculated from this equivalent circuit. The third part of this work is dealt with electromagnetic design of the alternating current machines by the help of a classic way and a new way.

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