Thesis (Ph. D.)--University of Wisconsin, 1907. / Bound with v. 4, no. 1-v. 4, no. 5 subsequent to publication. Includes bibliographical references (p. 85-88).

Orientador: Ernesto Ruppeert Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-16T04:00:35Z (GMT). No. of bitstreams: 1 Riehl_RudolfRibeiro_D.pdf: 5043112 bytes, checksum: b6091e6e6b5591d8885535a13baae465 (MD5) Previous issue date: 2010 / Resumo: O objetivo deste trabalho é o de apresentar uma nova metodologia para determinação experimental das capacitâncias parasitas do motor de indução trifásico de rotor em gaiola. As capacitâncias parasitas fazem parte do circuito equivalente do motor para estudos de interferência eletromagnética causada no motor de indução em modo comum quando ele for acionado por inversor controlado por modulação por largura de pulsos (MLP). Os procedimentos propostos para o desenvolvimento deste novo método consistem em: a) determinação dos parâmetros do circuito equivalente do motor de indução trifásico, em regime permanente, através de ensaio em laboratório; b) estabelecer configurações de ligações entre o inversor MLP e o motor para medições das grandezas de interesse que são as seguintes: tensões de modo comum e de eixo, correntes de fuga e de eixo, através de circuito de medição desenvolvido para este fim; c) calcular os valores das capacitâncias parasitas entre estator e carcaça do motor; estator e rotor; rotor e carcaça e de rolamento utilizando a expressão matemática da definição de capacitância; d) utilizar o software Pspice para simular o sistema motor de indução trifásico, alimentado por inversor MLP, com os circuitos equivalentes em baixas e altas frequências; e) obter as formas de onda características do fenômeno de modo comum / Abstract: Three-phase induction motors present stray capacitances. The aim of this thesis is to present a new methodology to experimentally determine these capacitances and also evaluates the effects of electromagnetic interference on the motors in common mode. The proposed procedures to the development of this new methodology consists in: a) identification of the motor equivalent electrical circuit parameters through characteristic tests performed in the laboratory; b) to set up configurations between PWM inverter and the motor for voltage and current measurements: common mode and shaft voltages, leakage and shaft (bearing) currents by using a dedicated measuring circuit; c) to calculate the parasitic capacitance values between stator and frame, stator and rotor, rotor and frame and bearings of the motor using the capacitance characteristic equation; d) use the dedicated software Pspice to simulate the system composed by the three-phase induction motor fed by PWM inverter with the equivalent electrical circuit parameters; e) to determine the characteristic waveforms involved in the common mode phenomenon / Doutorado / Energia Eletrica / Doutor em Engenharia Elétrica

M.Ing. (Electrical & Electronic Engineering Science) / This dissertation deals with the design and implementation of a hysteresis machine for high-speed applications. A model is introduced whereby the optimum working point of the machine can be determined. Hence it is possible to make a comparison between different rotor materials with respect to cost, specific energies and overall performance. The development of a compensator for actively controlling the phase angle of the airgap flux density, in order to reduce hunting, is discussed with reference to practical results. A technique for measuring real power in the frequency plane with the aid of a frequency spectrum analyzer, is explained. The design and evaluation of a hysteresis machine is based on practical results obtained from this measuring technique.

M. Ing. / The design of electric motor systems as we know it today, is very important and has a direct influence on the reliability of the system. In this dissertation, recommendations in design are given to obtain a reliable electric motor system. This dissertation covers a literature review of reliability engineering, and this is then applied to an electric motor system in order to determine the reliability of the system. This dissertation is divided into five parts: Problem definition, theory and literature survey, economics of reliability engineering, analysis and synthesis of an electrical motor system, conclusions and recommendations. Part I describes the environment of an electric motor system and presents some fundamental concepts of reliability engineering. It emphasizes the importance of reliability analysis in the design of electric motor systems. Part II describes some theory and literature about reliability. It emphasizes some existing reliability analysis methods for development of electric motor systems. The reliability prediction method is very useful for analysis of electric motor systems. The author emphasizes that economics of reliability engineering should be taken into account in the design process in Part III. The analysis of life cycle costs is very important. Life cycle costs (LCC) usually consist of the initial investment, preventive maintenance costs, repair costs and the costs for production losses and outages due to failures and disturbances. Life cycle costing methodology is useful in analyzing the design, reliability and maintenance during trade off of technical systems and equipments. Part IV focuses a specific electric motor system. Some existing reliability analysis methods are used to analyse reliability of electric motor systems. It is highlighted how to improve the reliability of electric motor systems. Some economics considerations are also presented in this section. The main conclusion reached in this dissertation is that failure data feedback, and accurate records are very important for reliability engineering. The author makes some recommendations for reliability of an electric motor system in design. This dissertation may contain direct information from sources indicated generally by. This is however generally contextualized within the main aim of the research. This is the result of specific communication obstacles.

This thesis proposes a technique to determine and improve the performance of a sensorless speed estimator for an induction motor based on Motor Current Signature Analysis (MCSA). The theoretical concepts underlying the parameter based observer are developed first and then the model of the observer is built using Simulink. The observer is developed based on Model Reference Adaptive System (MRAS). The dynamic performance of the observer and its behavior due to variation of machine parameters is studied. The error in speed estimated using this observer is shown and the ability of MCSA to retune the rotor speed from the stator current spectrum. The spectrum estimation technique has been implemented using a software routine in Matlab. Both the observer and MCSA techniques were implemented practically on an induction motor. The performance of the combined sensorless speed estimation system was tested and verified.

The problem of measuring low values of slip of induction machines is present in most Electrical Engineering laboratories. A rather high accuracy of the determination is necessary for theoretical calculations of motor loading, using equivalent circuit techniques. Conventional methods of determining slip fail to give high accuracy at low values of slip. This thesis presents a solution to this problem by describing the design and construction of a precision slip frequency detector of nominal cost. The principle employed is that of beat frequency comparison of the rotor shaft speed against line frequency. The output of the beat frequency detector actuates a multivibrator-differentiating circuit, the output of which triggers an electro-mechanical counter. A photoelectric pickup device for determining shaft speed is also discussed.

[pt] Este trabalho apresenta o desenvolvimento e testes de um sistema de acionamento de motores de passo em nível de micropasso, utilizando duas tecnologias distintas. A crescente capacidade de regulação e a possibilidade de chaveamentos precisos das correntes de fase dos motores de passo têm possibilitado o surgimento de acionamentos em micropasso cada vez mais eficientes. Com isto, a nociva, e, muitas vezes, limitadoras trepidação dos motores de passo operando em passo inteiro ou meio passo, foi quase todos os projetos de automação e robótica. Nos acionamentos convencionais, é fundamental o acompanhamento do nível da corrente na fase do motor. Este acompanhamento, por ser realizado em baixos níveis de tensão e na presença de ruído, acaba sendo um sério inconveniente exigindo uma montagem elaborada e eventuais filtros. O presente trabalho apresenta duas propostas de acionamentos em micropasso. Uma, do tipo convencional com realimentação de corrente de fase, e outra, em que a necessidade do acompanhamento da corrente é eliminado. Os teste indicam a viabilidade do novo conceito, apresentando resultados extremamente animadores. / [en] The present work discusses the development and experimental test of a step motor driver operating in microstepping mode. The work explores two different technologies for the power switching tecnhique. The increassing ability of fast and precise curent switching, brought to the market high performance step motors drivers operating in microstepping resolution. The main advantage of working with microstepping in a smooth operation with very low vibration level when compared with traditional full step of half step driving mode. This fact, made possible to specify step motors to many automatic and robotic systems where only servomotors could be used up to a very short past. In conventional chopper driving, it is necessary to sense the phase current, in order to chop the voltage when the level exceeded. This is done using very small resistor in series with the motor phases. The problem is that the low voltage across the resistor is easily affected by electromagnetic noise giving a false information to the chopper. The present research has explored the possibility of voltage chopping based on fixed timing with the elimination of the whole sensing circuitry. The first results are very encouraging.

<p> La présente étude traite de l'établissement d'un modèle mathématique, comprenant toutes les non-linéarités, d'un moteur à courant continu.</p> <p> Il a été nécessaire de rechercher pour cela de nouvelles techniques de mesures afin d'obtenir les différents paramètres avec un maximum de précision. L'originalité de ces mesures tient dans le fait que la machine est étudiée dans des conditions dynamiques d'expérience.</p> <p> A l'aide de ce modèle non-linéaire, il a été possible alors de montrer un éventail de comparaisons entre un moteur électromagnetique et un moteur à aimants permanents, dans le domaine des systèmes asservis.</p> <p> Cette étude démontre l'efficacité de l'outil que fournit ce modèle.</p> / Thesis / Master of Engineering (MEngr)

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Thesis (Ph.D.)--University of Western Sydney, Nepean, 1995. / Includes bibliography.