The objective of this thesis is to report the concept of driving a non-contacting steel plate conveyance system with a DSP-based closed-loop control structure. The lift force of the system is first estimated from the magnetic equivalent circuit (MEC) analysis, and the estimation results have been verified through three-dimensional finite element analysis (3-D FEA). Based on the force calculations and the fuzzy control theory, a closed-loop control structure has been designed. Through accurate signal detections, a real-time lift force control of the conveyance system can be realized. Finally, by feeding AC sources with DC bias to the stator windings of the motor, the lift and propulsive forces can be supplied to the steel plate simultaneously.

Based on the design concepts of linear induction motors, a non-contacting steel plate conveyance system for steel mill application has been constructed. To reduce the noise and friction from conventional roller conveyance system, the designed system is aimed to simultaneously provide adequate lift, propulsive, and guide forces to the steel plate. At first, the preliminary understandings of the characteristics of lift force have been gained through the simple magnetic circuit analyses, and together with other mechanical concepts develop the laboratory prototype. Then, through three-dimensional finite element analyses and state model developments, the system¡¦s static and quasi-dynamic/dynamic operational characteristics are investigated. Finally, the validity of this system has been verified by experimental measurement. Thus, the analyses and results of the experiment clearly show that the designed non-contacting steel plate conveyance system is certainly feasible.

<p> Of greatest interest in the field of linear motion electrical machines are, the flat linear induction motor and liquid metal pump. The former has feasibility in high speed transportation while the latter is becoming of increasing importance in metallurgical processes. </p> <p> This thesis examines and extends the traditional representation for the usual sheet secondary classification and then presents a common theory which also allows composite secondary machines to be analysed. An idealized model is developed consisting of a number of regions representing air gaps, iron segments, and secondary conductors. A general solution for the field quantities is obtained. The concept of wave impedance and a transfer matrix approach allow a wide variety of configurations to be analysed. Unlike previous work the approach developed here allows for simultaneous investigation of lateral variation and skin effect. In the limiting cases where in tum skin effect and lateral variation are neglected the solutions are in agreement with known results. </p> / Thesis / Master of Engineering (MEngr)

Cette thèse porte sur l’étude des performances du moteur linéaire de référence par la méthode d’analyse éléments finis, et la conception optimale sur un modèle lourd en temps de calcul. La méthode éléments finis est utilisée pour étudier les performances du moteur linéaire de référence, car le modèle analytique d’un moteur linéaire est difficile à construire dû aux effets d’extrémités. Le modèle éléments finis (MEF) 2D permet de prendre en compte l’effet d’extrémité de longueur finie. L’effet d’extrémité de largeur finie est intégré au modèle 2D en faisant varier la conductivité du secondaire et en ajoutant une inductance de tête de bobines. Ensuite, le couplage entre le MEF 3D magnétique et thermique permet de prendre en compte tous les effets d’extrémité et de l’influence de la température. Un banc d’essais est construit pour valider les modélisations éléments finis. La comparaison entre les différents modèles montre l’importance du modèle couplé. L’optimisation directe sur un MEF est très couteuse en temps de calcul. Les stratégies d’intégrer un modèle de substitution au lieu d’un MEF sont étudiées. L’optimisation directe sur un modèle de substitution et l’algorithme Efficient Global Optimisation (EGO) sont comparés. Un algorithme Space Mapping (SM) 3 niveaux est proposé. Les résultats des cas tests montrent que le SM 3 niveaux est plus efficace par rapport à l’algorithme SM 2 niveaux. Une nouvelle stratégie d’optimisation avec un faible budget d’évaluation du MEF est proposée et testée dans le contexte d’une modélisation difficile. La stratégie proposée permet d’évaluer les MEF en parallèle, ainsi permet un gain considérable de réduction du temps d’optimisation. / This thesis focuses on studying the performance of the linear induction motor using the method of finite element analysis, and the optimal design on a time-costly model. The finite element method is used to study the performance of the linear induction motor. Firstly, the 2D finite element model (FEM) is constructed, which allows taking into account the longitudinal end effects. The transverse edge effects are taken into account within 2D model by varying the conductivity of the secondary and by adding the inductance of the winding overhang. Secondly, a coupled model between the magnetic and thermal 3D FEM is built which allows taking into account both the end effects and the temperature influence. Finally, a test bench is realized to validate the models. The comparison between the different models shows the importance of the coupled model. Optimal design using finite element modeling tools is a complex task and also time-costly. The surrogate model-assisted optimization strategies are studied. The direct surrogate model-assisted optimization and the Efficient Global Optimization are compared. A three-level output space-mapping technique is proposed to reduce the computation time. The optimization results show that the proposed algorithm allows saving a substantial computation time compared to the classical two level output space-mapping. Using the 3D FEM, a multi-objective optimization with a progressive improvement of a surrogate model is proposed. The proposed strategy evaluates the FEM in parallel. A 3D Pareto front composed of the finite element model evaluation results is obtained, which allows taking the decision for the engineering design.

Šiame baigiamajame darbe tiriamas elektriškai ir magnetiškai dvipusio tiesiaeigio asinchroninio variklio (TAV) valdymo būdas, keičiant vieno iš induktorių maitinimo įtampos fazę kito induktoriaus maitinimo įtampos fazės atžvilgiu. Įvade suformuluotas darbo tikslas ir paminėtos TAV taikymo galimybės. Atlikta literatūros šaltinių analizė ir apžvelgti tiesiaeigiai asinchroniniai varikliai bei jų konstrukcijos. Pateikti šių variklių privalumai, trūkumai ir panaudojimo sritys. Teorinėje dalyje išanalizuotos tiesiaeigės stūmiklių pavaros ir apžvelgti specialūs tiesiaeigių variklių valdymo būdai. Išanalizuotos statinės charakteristikos ir sudaryta skaičiavimo metodika. Tiriamojoje dalyje sudarytas TAV modelis ir imituotos dinaminės charakteristikos. Pagamintas ir išbandytas TAV bandymų stendas, pateiktos išvados. Pasiūlyta tiesiaeigės stūmiklio pavaros funkcinė ir elektrinė principinė schemos. Darbą sudaro 7 dalys: įvadas, literatūros analizė, tyrimo tikslas ir uždaviniai, tiriamoji dalis eksperimentinė dalis, tyrimo rezultatų apibendrinimas, literatūra ir kt. šaltiniai. Darbo apimtis – 70 p. teksto be priedų, 49 iliustr., 3 lent., 24 bibliografiniai šaltiniai. / Electrically and magnetically control mode of two-sided linear induction motor (LIM) is analysed in this thesis. It is done by changing one of the voltage power supply inductor phase regard to next phase inductor. The main goal of thesis and LIM application possibilities are formulated in introduction. Literature review and analysis of linear induction motors and their construction was accomplished. The use of energy, main advantages and disadvantages of these motors were represented. Special control techniques, analysis of linear pushing drives and linear motors were analysed in theoretical section. LIM static characteristics and calculation methodology is provided in this section either. In the research section consist of LIM mathematical model, where dynamic characteristics are simulated. The actual LIM model was made and tested, experiment conclusions were written. The linear spindle drive functional and electrical diagrams were proposed. The work consists of seven sections: introduction, literature review, the study of aims and objectives, experimental section, investigating LIM and providing results, literature and others sources. Work size - 70 p. text without appendixes, 49 pictures., 3 tables., 24 bibliographic sources.

Desde a idealização das máquinas elétricas girantes, o motor de indução linear (MIL) fora também considerado viável e, ao longo do tempo, foi pesquisado e foram desenvolvidas novas tecnologias para sua melhoria e para o seu acionamento. Muitos trabalhos acadêmicos foram realizados em todos os centros de pesquisa do mundo e, no Brasil, os primeiros a estudá-lo com rigor científico foram os professores Morency Arouca e Délio Pereira Guerrini, no início da década de 70, no departamento de Engenharia Elétrica da EESC/USP. Até hoje no Brasil, pouco se desenvolve neste campo de estudo da Engenharia Elétrica e, quando se desenvolve, ficam restritos à simulações e levantamentos de parâmetros característicos aos MIL\'s específicos. O presente trabalho tem como objetivo fazer uma explanação teórica e matemática que servirá de base ao estudo e compreensão do MIL e propor uma aplicação ao mesmo: o MIL acionado por inversor de freqüência e utilizado para obtenção de posicionamento com auxílio de simulação computacional de algumas malhas de controle para tal posicionamento. / Since the rotating machines had been idealized, the Linear Induction Motor (LIM) has been researched and, along the time, new technologies are being developed in order to improve it. Many academic works were accomplished in several research centers and universities around the world. In Brazil, the first ones to study it with scientific approach were Professors Morency Arouca and Délio Pereira Guerrini, in the early 70\'s. Even nowadays, works are seldom developed, and most of them are dedicated to simulation of the LIM or obtaining of parameters of specific LIM\'s. The present work has as objective to study the mathematical and theoretical modeling, which will be used as basis in order to study and understand the LIM and to propose an application: the LIM fed by Frequency Inverter, used in order to obtain positioning, with simulation of specific control systems.

O Motor Assíncrono Tubular para Aplicação na Extração de Óleo do Subsolo MATÆOS foi desenvolvido na Escola Politécnica da Universidade de São Paulo (EPUSP) com a função de acionar diretamente uma bomba de sucção, instalada no fundo de um poço de petróleo em terra. Dando continuidade aos trabalhos realizados na EPUSP envolvendo sistemas de levitação magnética, foi desenvolvido um mancal magnético ativo (AMB - Active Magnetic Bearing), aplicado ao protótipo do motor em substituição ao mancal mecânico tradicional existente. O projeto abrange a construção de um protótipo de mancal magnético composto das partes mecânicas, elétricas e de software necessárias ao funcionamento do sistema. O projeto do eletroímã foi realizado por meio do método dos elementos finitos (MEF), para análise da densidade de fluxo e da relação entre a força radial e a corrente elétrica nas bobinas. O controle da levitação do mancal é realizado por meio de controlador digital com placas conversoras AD/DA e algoritmo de controle implementado em hardware FPGA. Utilizando o modelo do sistema, os controladores são sintonizados para atender aos requisitos de estabilidade e rejeição de perturbações, que desviem o entreferro do seu valor nominal. Na configuração do AMB, ao invés do sistema tradicional com oito pólos, um conceito diferente é adotado. Neste, uma máquina primitiva bearingless é excitada com corrente contínua e usada como mancal magnético. Os resultados experimentais obtidos com o protótipo em funcionamento mostram que o sistema em malha fechada é estável e apresenta uma resposta transitória satisfatória. / A tubular linear induction motor applied to onshore oil exploitation, named MATÆOS (which is in the Portuguese acronym for Tubular Asynchronous Motor for Onshore Oil Exploitation) was built at Escola Politécnica da Universidade de São Paulo (EPUSP). Its purpose is to directly drive the sucker-rod pump installed in the down hole of the oil well. In continuing the research accomplished at EPUSP concerning magnetic levitation systems, an Active Magnetic Bearing (AMB) was developed and applied to the prototype of the motor in substitution to the existing traditional bearing. The design includes the construction of the magnetic bearing prototype composed of mechanical, electric and software components required to the operation of the system. The electromagnet design was accomplished using the Finite Element Method (FEM) in the analysis of both the flux density and the relationship between the radial force and the suspension winding current. The magnetic bearing levitation control is executed by a digital controller using an AD/DA converter and a control algorithm implemented in FPGA hardware. Using the system model, the controllers are tuned to provide both stability and rejection of disturbances that tend to move the air gap from its nominal value. Instead of the usual eight-pole AMB, a different concept is adopted where a DC-excited primitive bearingless machine is used as a magnetic bearing. The experimental results obtained with the prototype in operation show that the closed-loop system is stable and exhibits a satisfactory transient response.

Um atuador planar de indução é um dispositivo baseado no mesmo princípio de funcionamento de um motor linear de indução, onde a interação de um campo magnético viajante produzido pelo primário do dispositivo com uma superfície de boa condutividade elétrica induz correntes parasitas que levam à produção de uma força de propulsão. O movimento planar sobre essa superfície é produzido através da movimentação linear em dois eixos ortogonais. Uma aplicação deste movimento é na propulsão de uma plataforma equipada com câmeras e sensores para a realização da inspeção em uma superfície metálica, que se beneficiaria da força normal que o motor planar de indução produz quando acionado sobre uma superfície ferromagnética para anexar a plataforma à superfície. Um modelo analítico que fornece equações para o campo elétrico e magnético é apresentado, e simulações numéricas baseadas no método dos elementos finitos são realizadas para avaliar o comportamento do dispositivo utilizando três tipos diferentes de superfícies como secundário: um secundário com duas camadas formadas por uma chapa de alumínio com outra de aço por baixo; apenas a chapa de alumínio; e apenas a chapa de aço. As distribuições de campo magnético calculadas por estes dois modelos teóricos mostram boa concordância entre si, e são utilizadas para calcular as forças de propulsão e normal produzidas pelo atuador. Medidas experimentais são realizadas em um protótipo de atuador planar de indução, e seus resultados são comparados com os resultados obtidos nos modelos teóricos, mostrando uma boa concordância e potencial para a aplicação do atuador planar de indução na inspeção de superfícies horizontais. / An induction planar actuator is a device that, based on the operating principle of a linear induction motor, in which the interaction between a travelling magnetic field produced by the primary of the device and a conducting surface generates eddy currents in the surface and leads to the generation of a thrust force. The device produces planar motion over this surface through movement on two orthogonal axis. An application of this movement is in a platform for the inspection of metallic surfaces, which is driven by the planar induction motor and equipped with cameras and sensors to inspect the surface. This application benefits from the normal force produced by the induction planar actuator operating over a ferromagnetic surface to attach the driving platform to it. An analytical model with equations for the electric and magnetic fields is presented, and numerical simulations based on the finite element method are carried out to assess the behaviour of the device using three different surfaces as secondary: a double-layered secondary formed by an aluminum plate over a steel plate; a aluminum only plate; and a single steel plate. The distributions for the magnetic field computed through these theoretical models show good agreement, and are employed to evaluate the thrust and normal forces produced by the planar induction actuator. Experimental measurements are made on a prototype of the device, and the results are compared to the results of the theoretical models, showing good agreement and potential in the application of the induction planar motor for the inspection of horizontal metallic surfaces.

The analysis of the feature and application of linear induction motors at work have been performed; mathematical models of linear motors have been studied; mathematical description of induction machine have been presented; coordinate transform have been studied; dynamic equations in moving and move-less systems of axes of linear induction motor have been presented; the analysis of the classification of induction drives control modes have been performed. Four models of the frequency-regulated electric drives with linear induction motors have been studied: when the motor is supplied from variable frequency mains supply, when the motor is supplied from frequency converter, when frequency is changed by program, when frequency is changed in close-loop by vector control system. The characteristics of those models have been compared and performed. The received results are summarized in the conclusions.

Baigiamajame magistro darbe nagrinėjama elektros pavaros su tiesiaeigiu asinchroniniu varikliu konstrukciniai ypatumai, savybės, mechaninės charakteristikos bei kokybės rodikliai. Programiniu paketu MathCAD 2001 Professional yra sudarytas matematinis tiesiaeigio asinchroninio variklio modelis. Tyrimas atliekamas eksperimentiniu būdu, keičiant TAV parametrus (Reynoldso skaičių, neferomagnetinį sluoksnį, oro tarpą, induktoriaus plotį, variklio apvijų skaičių ir pan.), gaunamos tam tikram modeliui būdingos mechaninės charakteristikos. Magistro darbe pateikiama bendra elektros pavarų su tiesiaeigiais asinchroniniais varikliais apžvalga ir jų savybių analizė. Tiriamoji dalis apima apibendrinto tiesiaeigio asinchroninio variklio matematinio modelio sudarymą ir mechaninių charakteristikų tyrimą programiniu paketu MathCAD 2001 Professional. Programa skaičiavimo rezultatus pateikia grafiniu pavidalu. Gauti rezultatai yra analizuojami ir apibendrinami. Išnagrinėjus teorinius ir praktinius tiesiaeigio asinchroninio variklio darbo režimų aspektus, pateikiamos išvados ir pasiūlymai. Tyrimo rezultatai gali būti panaudoti elektros pavarų su tiesiaeigiais asinchroniniais varikliais racionaliam ir optimaliam realizavimui greitaeigių elektros pavarų technologinėse sistemose. Darbą sudaro 7 dalys, įvadas, literatūros elektros pavaros su tiesiaeigiu asinchroniniu varikliu klausimais apžvalga, tyrimo tikslas ir uždaviniai, skaičiuojamoji dalis, tyrimo rezultatų apibendrinimas, išvados ir... [toliau žr. visą tekstą] / In master thesis researching high-speed electric drive with Linear Induction Motor (LIM) design peculiarities, internals and indexes of quality. Using program MathCAD 2001 Professional was created mathematical model of Linear Induction Motor. By changing Linear Induction Motor parameters (Reynolds's number, SE thickness, air gap, inductor width, number of coils and etc) getting for the defined model appropriate mechanicals characteristics. In master thesis the view of electric drive with Linear Induction Motor has been reviewed and their features analyzed. In the investigation part involves the creation of Linear Induction Motor mathematical model and investigation of mechanicals characteristics on program pack MathCAD 2001 Professional. The program displays results in graphical form. The results are analyzed and generalized. After analyzing theoretical and practical LIM motor aspects of operations, conclusions and suggestions are formed. The results of research can be used for rational and optimal realization of LIM in various technological systems. Structure: introduction, literature electrical drive with LIM questions review, research purpose and tasks, calculation part, summary of research results, conclusions and suggestions, references.