Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Mechanical Engineering, 2009. / Includes bibliographical references.

Η εργασία αυτή εχεις ως αντικείμενο την μελέτη και την κατασκευή ενός μετατροπέα συντονισμού για την οδήγηση ενός πιεζοηλεκτρικού κινητήρα οδεύοντος κύματος τύπου Ultrasonic. Αρχικά γίνεται μια θεωρητική αναφορά στους πιεζοηλεκτικούς κινητήρες και τους ηλεκτρονικούς μετατροπείς ισχύος ενώ ακολουθεί η προσομοίωση του μετατροπέα στο Pspice. Ακολούθως αναλύεται η διαδικασία της κατασκευής και ακολουθούν τα πειραματικά αποτελέσματα καθώς και τα συμπεράσματα που λάβαμε. / In this thesis someone can find about designing and manufacturing a resonant inverter in order to control a piezoelectric traveling wave ultrasonic motor. In the first chapters someone can read about the piezoelectric phenomenon, piezoelectric motors and about electronic converters which control the velocity of motors. Next there is a presentation of the Pspice simulation model and results. Furthermore there is the manufacturing procedure of the inverter and at the end there are the results and conclusion of the thesis.

Στόχος της παρούσας διπλωματικής εργασίας, που εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Πανεπιστημίου Πατρών, είναι η μελέτη και κατασκευή ενός διπλοσυντονιζόμενου μετατροπέα για την οδήγηση πιεζοηλεκτρικού κινητήρα οδεύοντος κύματος τύπου ultrasonic. Αρχικά, γίνεται παρουσίαση των πιεζοηλεκτρικών κινητήρων, δηλαδή η αρχή λειτουργίας τους, τα πλεονεκτήματα και μειονεκτήματά τους καθώς και οι διαφορές τους σε σχέση με τους συμβατικούς ηλεκτροκινητήρες. Επίσης, γίνεται παρουσίαση των μετατροπέων συντονισμού που χρησιμοποιούνται σήμερα για την οδήγηση κινητήρων και τέλος προσομοιώνεται ο διπλοσυντονιζόμενος μετατροπέας με σκοπό να εξαχθούν χρήσιμα συμπεράσματα για τη συμπεριφορά του. Στη συνέχεια, πραγματοποιείται η μελέτη για την κατασκευή του διπλοσυντονιζόμενου μετατροπέα με τα χαρακτηριστικά που επιλέξαμε, καθώς επίσης και το κύκλωμα παλμοδότησης που χρησιμοποιήθηκε. Ο μετατροπέας αποτελείται από δύο ημιγέφυρες, οι οποίες οδηγούνται από ειδικό για το σκοπό αυτό ολοκληρωμένο. Στην έξοδο των δύο ημιγεφυρών έχουν τοποθετηθεί πυκνωτές και πηνία για τη δημιουργία του κυκλώματος συντονισμού. Ο μετατροπέας που κατασκευάστηκε προσφέρει μεγάλο εύρος ρύθμισης των στροφών του πιεζοηλεκτρικού κινητήρα, μεγάλη περιοχή ελέγχου ως προς τη συχνότητα λειτουργίας του κινητήρα λόγω της μεγάλης γραμμικής περιοχής ανάμεσα στις συχνότητες συντονισμού, καθώς και τη δυνατότητα δεξιόστροφης αλλά και αριστερόστροφης κίνησης. / The object of the present diploma study, which was elaborated in the Laboratory of Electromechanical Energy Transformation in University of Patras, was the design and construction of a LLCC resonant inverter for a Travelling Wave Ultrasonic Motor (TWUM) drive. Initially, there is a presentation of the piezoelectric motors, their advantages and disadvantages and their differences in comparison with the conventional electric motors. Also, a presentation of the resonant inverters used for driving ultrasonic motors and finally, the LLCC resonant inverter is simulated so as to extract useful conclusions about its behavior. Furthermore the development and construction process of an experimental LLCC resonant inverter is described. Special care has been taken in the dimentioning of the resonant capacitors and inductions. The final circuit consists of two half – bridges, which are driven by a FPGA. The constructed inverter provides a wide driving range of the piezoelectric motor, a large control area according to the functional frequency of the motor, due to the large linear area between the two resonant frequencies, as well as the ability of both right and left rotation.

Orientador: Celso Pinto Morais Pereira / Banca: José Geraldo Trani Brandão / Banca: Mauro Pedro Peres / Banca: Marcio Tadeu de Almeida / Banca: Carlos Alberto Chaves / Resumo: O presente trabalho visa constatar a alteração nas freqüências de ressonância de rotores, considerando o efeito da flexibilidade dos discos, bem como o momento fletor aplicado ao eixo devido ao efeito giroscópico. A análise por matriz de transferência é utilizada para obter as freqüências naturais do sistema, considerando-o sem amortecimento, e movimento em órbita circular. Realizou-se uma fase experimental, a fim de se verificar a teoria desenvolvida, bem como observar os modos de vibrar do disco, do eixo, e do sistema disco-eixo, e suas respectivas freqüências naturais. / Abstract: The main objective of this work is to investigate the resonant frequencies of rotors, taking into account not only the flexibility of the discs, but also the bending moment (due to the gyroscopic effect) applied to the shaft. The theorical analysis is based in the transfer matrix technique. The system was assumed to be undamped with the shaftdisc in circular orbit motion. An experimental work was carried out in order to obtain the mode shapes and the natural frequencies of the disc, shaft, and of the disc-shaft system. A good correlation was observed between the theorical and experimental results. Keywords: resonant frequencies, flexibility of the discs, disc-shaft system, transfer matrix method. / Doutor

Este trabalho trata da utilização de um método de sintonia de controladores baseado nos dados obtidos da planta. A proposta é a sintonia de controladores ressonantes para aplicação em inversores de frequência presentes em fontes ininterruptas de energia, com o intuito de seguimento de referência senoidal de tensão. Dentro deste contexto, será usado o algoritmo Virtual Reference Feedback Tuning, o qual é um método de identificação de controladores baseado em dados que não é iterativo e não necessita do modelo do sistema para identificar o controlador. A partir dos dados obtidos da planta e também da definição de um modelo de referência pelo projetista, o método estima os parâmetros de uma estrutura fixada previamente para o controlador através da minimização de uma função custo definida pelo erro entre a saída desejada e a saída real. Além disso, uma realimentação de corrente é necessária na malha de controle, onde seu ganho proporcional é definido por experimento empírico. Para demonstrar a utilização do método são apresentados resultados simulados e práticos de uma fonte ininterrupta de energia com potência de 5 kV A utilizando cargas lineares e não-lineares. É avaliado o desempenho do ponto de vista da qualidade do sinal de saída real obtido com controladores sintonizados a partir de diferentes modelos de referência, além do uso de sinais de excitação diversos para o algoritmo V RFT. Os resultados experimentais são obtidos em um inversor de frequência monofásico com uma plataforma em tempo real baseada na placa de aquisição de dados dSPACE DS1104. Os resultados mostram que, em relação as normas internacionais, o sistema de controle proposto possui bom comportamento para seguimento de referência, operando à vazio ou utilizando carga linear. / This work discusses about controller tuning methods based on plant data. The proposal is to tune resonant controllers for application to the frequency inverters found in uninterruptible power supplies, with the goal of following sinusoidal reference signals. Within this context, the Virtual Reference Feedback Tuning algorithm is used, which is a data-driven controller identification method that is not iterative and does not require a system model to identify the controller. Data obtained from the plant and also the definition of a reference model by the designer, are used by the method to estimate the parameters of a previously fixed controller structure through the minimization of a cost function, which is defined by the error between desired and actual outputs. Moreover, a current feedback is required in the control loop where the proportional gain is defined by empirical experiment. To demonstrate the method’s application, simulated and practical results of an uninterruptible power supply with capacity of the 5 kV A will be presented employing linear and nonlinear loads. Evaluates the performance in terms of system’s actual output quality, obtained with controllers tuned with different reference models. Distinct excitation signals are also used to feed the VRFT algorithm. The experimental results achieved from use of an single-phase inverter and a real-time platform based on data acquisition board dSPACE DS1104. The results show that, with respect to international standards, the proposed control system has good performance for tracking reference, operating at empty or using linear load.

Nesse trabalho é apresentada uma estratégia de controle para manter a potência entregue a carga do link indutivo de um sistema de transferência de potência sem fios maximizada continuamente. Inicialmente, foi desenvolvido o modelo do link indutivo do sistema, de forma a encontrar uma expressão para a potência na carga. Em seguida, essa expressão foi analisada, buscando os pontos de potência máxima correspondentes às frequências ressonantes quando o fator de acoplamento magnético do link indutivo era variado. Assim, foi estabelecido um método para estimar esse fator de acoplamento k e consequentemente da indutância mútua M a partir do monitoramento direto da fase e do módulo da corrente de entrada do link e indireto da impedância de entrada. Portanto, a estratégia de controle proposta consiste em monitorar a corrente da fonte de entrada do link para estimar o fator de acoplamento magnético k e finalmente, sintonizar a fonte na frequência de ressonância associada ao coeficiente de acoplamento magnético pela função obtida fres(k). Os resultados experimentais mostraram que a estratégia proposta aumenta significativamente a potência entregue a carga em comparação a uma fonte de alimentação sintonizada em uma frequência fixa. / A control strategy is presented in this work to maintain the power delivered to a load continuously maximized at the output of a wireless power transfer system. Initially, the inductive link model of the system was developed in order to find an expression for the power delivered to the load. Thus, the maximum power delivered to the load points were obtained experimentally while the magnetic coupling factor of the inductive link was varied and associated with the frequency of the source. The frequency and magnetic coupling variables were related to the maximum power on the load by a simple analytic function. Thus, a method has been established to estimate the coupling factor k and consequently the mutual inductance M by direct monitoring of the phase and the module of the input current of the link and indirect monitoring of the input impedance. Therefore, the proposed control strategy is to monitor the current of the input source of the link to estimate the magnetic coupling factor k and finally to tune the source at the resonance frequencies associated to the magnetic coupling coefficient by the obtained function fres(k). The experimental results showed that the proposed strategy increases significantly the power delivered to the load compared to a power source tuned at a fixed frequency.

Orientador: Carlos Alberto Canesin / Resumo: Neste trabalho, apresentou-se o estudo de um gerador eletrocirúrgico utilizando um conversor ressonante. Com o intuito de realizar procedimentos cirúrgicos, o bisturi elétrico, ou eletrônico, apresenta grandes vantagens ao método clássico do bisturi de aço inoxidável. Para conseguir os efeitos terapêuticos desejados, corte e coagulação, sem que haja qualquer estímulo nervoso, utiliza-se sinal senoidal com alta frequência. Os conversores ressonantes são estruturas chaveadas que operam em elevadas frequências com baixas perdas, logo, alto rendimento. Fez-se, então, um estudo sobre as estruturas inversoras e os filtros ressonantes. A sequência do trabalho trata da análise da estrutura proposta (Full-Bridge – LCLC – ZVS – FM) demonstrando as etapas envolvidas em um ciclo de chaveamento do conversor e o seu equacionamento. A partir de uma metodologia para calcular os parâmetros do filtro, definiram-se os valores das indutâncias e das capacitâncias séries e paralelas. Projetou-se o controlador pormeio de umametodologia que visa o controle pelos valores de pico das formas de onda. Realizaram-se simulações dos modos de operação desejados e observaram-se os valores encontrados da tensão de saída, da corrente de saída, da corrente de entrada e a comutação ZVS para variadas cargas. Implementou-se um protótipo do qual os resultados práticos obtidos são apresentados e discutidos. / Abstract: In this work, a study of an electrosurgical generator was presented using a resonant converter. In order to perform surgical procedures, electric or electronic scalpel presents great advantages to the classic method of the stainless steel scalpel. To achieve the desired therapeutic effects, cutting and coagulation, without any nerve stimulation, sine wave signal is applied with high frequency. Resonant converters are switched structures that operate at high frequencies with low losses, hence, high efficiency. A study was then made about inverter structures and resonant filters. The work sequence was the analysis of the proposed structure (Full-Bridge LCLCZVS- FM) demonstrating the steps involved in a converter switching cycle and its equation. From a methodology to calculate filter parameters, values of series and parallel inductances and capacitances were defined. The controller was designed using a methodology that controls the peak values of the waveforms. Simulations of the desired modes of operation were executed out and the values of output voltage, output current, input current and ZVS switching were observed for various loads. A prototype was implemented and the results obtained are presented and discussed. / Mestre

Dans cette thèse, nous avons considéré les spectres de la molécule CH2=CD2. Dans la partie expérimentale, nous avons enregistré des spectres infrarouges à haute résolution (~ 0,0025 cm-1) et fait une attribution complète des transitions enregistrées. Nous avons pu assigner pour la première fois un grand nombre de transitions des combinaisons peu intenses υ4+υ10, υ4+υ7 et de l'harmonique 2υ10; de bandes interdites par symétrie υ4, υ7+υ10, υ8+υ10; et des bandes «chaudes» υ7+υ10–υ10 et υ8+υ10–υ10. Pour la première fois, plus de 7000 transitions inconnues des bandes fondamentales υ2, υ3, υ6, υ7, υ8, υ10, υ12 et de l'harmonique 2υ7 ont été assignées. Sur la base de la théorie des opérateurs de perturbation et des propriétés de symétrie de la molécule étudiée, nous avons construit un hamiltonien effectif puis ajusté les énergies vibrationnelles expérimentales de quatorze états vibrationnels. De cette étude, il a résulté un écart-type pour l'ajustement d'environ (1,7–2,5)×10−4 cm−1 pour diverses régions spectrales. Nous avons également mesuré les valeurs expérimentales des intensités et des demi-largeurs et avons calculé les paramètres du moment dipolaire effectif et des coefficients d'auto-élargissement de la molécule CH2=CD2. / In this thesis we have considered spectra of the CH2=CD2 molecule. In the experimental part we recorded high-resolution (~ 0.0025 cm-1) infrared spectra and made full assignment of the recorded transitions. We were able to assign for the first time a lot of transitions to the weak combinations υ4+υ10, υ4+υ7 and 2υ10 overtone; forbidden due to the symmetry υ4, υ7+υ10, υ8+υ10; «hot» υ7+υ10–υ10 and υ8+υ10–υ10 bands. More than 7000 previously unknown transitions were assigned to the fundamental bands υ2, υ3, υ6, υ7, υ8, υ10, υ12 and 2υ7 overtone. On the base of operator perturbation theory and the symmetry properties of the studied molecule, we constructed an effective Hamiltonian and then fitted experimental ro-vibrational energies of fourteen vibrational states. As a result, rms-deviation of the fit was about (1.7–2.5)×10−4 cm−1 for various spectral regions. We measured also experimental values of intensities and halfwidths and calculated parameters of effective dipole moment and self-broadening coefficients of the СH2=СD2 molecule.

abstract: This work is an investigation into the information provided by the concurrent use of in situ reflection high energy electron diffraction (RHEED) and reflection electron energy loss spectroscopy (REELS). The two analytical methods were employed during growth of metal, semiconductor and superconductor thin films by molecular beam epitaxy (MBE). Surface sensitivity of the REELS spectrometer was found to be less than 1 nm for 20 KeV electrons incident at a 2 degree angle to an atomically flat film surface, agreeing with the standard electron escape depth data when adjusted incident angle. Film surface topography was found to strongly influence the REELS spectra and this was correlated with in situ RHEED patterns and ex situ analysis by comparison with atomic force microscopy (AFM). It was observed in all the experimental results that from very smooth films the plasmon peak maxima did not fall at the predicted surface plasmon values but at slightly higher energies, even for nearly atomically flat films. This suggested the REELS plasmon loss spectra are always a combination of surface and bulk plasmon losses. The resulting summation of these two types of losses shifted the peak to below the bulk plasmon value but held its minimum to a higher energy than the pure surface plasmon value. Curve fitting supported this conclusion. / Dissertation/Thesis / Ph.D. Engineering Science 2012

Physiological functions of a biomacromolecule seem to be closely related to its molecular conformations. The knowledge of any conformational changes due to changes in its environment may lead to a proper understanding of its functions. Hyaluronic acid, a biomacromolecule with unusually high molecular weight and some important biological functions is the subject of the present work. A temperature-dependent transition in hyaluronate solution of 120 mg/ml concentration was observed at physiological temperature. It is shown that this temperature-dependent behavior can be related to the orientational polarizability term in the Debye theory of polar molecules in liquids.