Η παρούσα διπλωματική εργασία πραγματεύεται την μελέτη και κατασκευή ενός συστήματος ελέγχου για έναν κινητήρα μαγνητικής αντίδρασης (Reluctance). Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών της πολυτεχνικής σχολής του Πανεπιστημίου Πατρών. Σκοπός της εργασίας αυτής, είναι η μελέτη και η κατασκευή ενός τριφασικού αντιστροφέα πηγής τάσης, ο οποίος θα επιτρέπει την υλοποίηση βαθμωτού και διανυσματικού ελέγχου για έναν σύγχρονο κινητήρα μαγνητικής αντίδρασης χωρίς έκτυπους πόλους στο στάτη. Ο σύγχρονος κινητήρας μαγνητικής αντίδρασης χωρίς έκτυπους πόλους στο στάτη, όπως και οποιοσδήποτε άλλος κινητήρας μαγνητικής αντίδρασης, βασίζει τη λειτουργία του στη ροπή αντίδρασης, γεγονός από το οποίο προέρχεται και η ονομασία των κινητήρων αυτού του είδους (ReluctanceMotors). Το κύριο χαρακτηριστικό των κινητήρων μαγνητικής αντίδρασης είναι η έλλειψη οποιασδήποτε πηγής διέγερσης στο δρομέα. Τα τελευταία χρόνια έχει αναπτυχθεί έντονο επιστημονικό ενδιαφέρον σχετικά με τη βελτιστοποίηση της κατασκευής των σύγχρονων κινητήρων μαγνητικής αντίδρασης χωρίς έκτυπους πόλους στο στάτη, καθώς και των μεθόδων ελέγχου, που μπορούν να εφαρμοστούν για βελτιστοποίηση της λειτουργίας τους. Αρχικά μελετήθηκαν οι βασικές αρχές λειτουργίας των μηχανών εναλλασσόμενου ρεύματος και η ανάλυση επικεντρώθηκε στο σύγχρονο κινητήρα μαγνητικής αντίδρασης. Μελετήθηκαν τα κατασκευαστικά χαρακτηριστικά του σύγχρονου κινητήρα μαγνητικής αντίδρασης χωρίς έκτυπους πόλους στο στάτη, το μαθηματικό μοντέλο που περιγράφει τη λειτουργία του, συγκρίθηκε με άλλους τύπους κινητήρων εναλλασσόμενου ρεύματος και παρουσιάστηκαν οι μέθοδοι ελέγχου που μπορούν να εφαρμοστούν σε έναν σύγχρονο κινητήρα μαγνητικής αντίδρασης χωρίς έκτυπους πόλους στο στάτη. Επιπλέον μελετήθηκε ο τριφασικός αντιστροφέας πηγής τάσης, ο οποίος είναι απαραίτητος για την οδήγηση ενός σύγχρονου κινητήρα μαγνητικής αντίδρασης, καθώς και διάφορες τεχνικές για την παλμοδότησή του. Τέλος προσομοιώθηκε ο σύγχρονος κινητήρας μαγνητικής αντίδρασης με το πρόγραμμα προσομοίωσης Matlab/Simulink για διάφορες καταστάσεις λειτουργίας του, και ακολούθησε η κατασκευή του τριφασικού αντιστροφέα για την πειραματική διερεύνηση και επιβεβαίωση των αποτελεσμάτων της προσομοίωσης. / The present diploma thesis deals with the design and manufacture of a control system for a Reluctance Motor. This work was developed in the Laboratory of Electromechanical Energy Conversion at the Department of Electrical Engineering and Computer Technology of the School of Engineering in the University of Patras, Greece. The purpose of this thesis is the design and manufacture of a three-phase voltage source inverter for the control of the performance of a Synchronous Reluctance Motor by the implementation of Scalar and Vector control. The operation of Synchronous Reluctance Motor, like any other type of Reluctance Motors, is based on reluctance torque. The main characteristic of Reluctance Motors is that the rotor does not have any field winding. During the last years, a great interest has emerged around the Synchronous Reluctance Motor, which mainly focuses on the optimization of its construction and control. At first, an introduction to the operation principles of the AC motor is done, while the main interest is focused on Synchronous Reluctance Motor. The analysis of Synchronous Reluctance Motor covers many aspects, such as its construction characteristics, its dynamic model, its control strategies, as well as a comparison with other AC motors. Furthermore the three phase inverter is studied and its modulation techniques, since it is used for the driving of the motor. Finally the Synchronous Reluctance Motor is simulated in Matlab/Simulink for some operating conditions, and a three phase voltage source inverter is constructed for the experimental investigation and to see the relationship between the results of the simulation and the experiment.

Cette thèse porte sur l’étude et l’optimisation aérothermique d’un alterno-démarreur utilisé dans les véhicules hybrides. Ces machines produisant beaucoup plus de puissance qu’un alternateur classique, leur refroidissement est donc critique. La machine est modélisée en utilisant la méthode nodale en régime permanent qui utilise des réseaux de conductances thermiques. Pour alimenter le modèle, on utilise des corrélations issues de la littérature pour modéliser les transferts convectifs et on effectue des calculs CFD de la machine complète pour obtenir la répartition des débits. Les résultats obtenus numériquement sont ensuite validés expérimentalement à l’aide d’essais par Vélocimétrie par Images de Particules et d’essais thermiques par mesure thermocouples. Dans un deuxième temps, on couple un algorithme d’optimisation au code pour obtenir une géométrie de la machine optimale d’un point de vue thermique. La méthode retenue est l’Optimisation par Essaim Particulaire (PSO). L’optimisation se fait sur la taille des têtes de bobines, la position des ventilateurs et la section des canaux rotoriques. On obtient des géométries différentes selon les objectifs que l’on cherche à atteindre. La dernière partie de la thèse porte sur l’optimisation multi-objectifs d’un dissipateur située sur la partie électronique à l’arrière de l’alternateur : le dissipateur doit refroidir le plus possible l’électronique sans pour autant perturber l’écoulement. On étudie aussi plusieurs formes d’ailettes pour atteindre ces objectifs. / The goal of this thesis is the aero-thermal study and optimization of a starter-alternator used in hybrid cars. This kind of machines being more powerful than a regular alternator, their cooling is critical. The machine is modeled using lumped method in steady state which uses networks of thermal conductances. The inputs for the model are obtained using correlations from bibliography for the convective heat transfers and three dimensional CFD for the flow rates inside the machine. The numerical results are validated by experimental results with PIV for the fluid results and a machine fitted with thermocouples for the thermal part. In the second part, the thermal code is coupled with an optimization algorithm to obtain an optimal geometry of the machine from a thermal point of view. The method chosen is Particle Swarm Optimization (PSO). The parameters are the sizes of the end-windings, the positions of the fans and the cross section of the rotor channels. For different objectives, different optimal geometries are obtained. The last part of this work aims at the multi-objectives optimization of a heat sink located at the back of the machine. The heat sink has to be thermally efficient but should not affect the flow. Different shapes of fins are also studied.

Este trabalho propõe uma investigação sobre a influência da alocação da área de mancal em compressores herméticos para a refrigeração, considerando um motor Síncrono de Ímãs Permanentes com Partida Direta na Rede (LSPMSM) monofásico, e utilizando cálculos analíticos convencionais e o Método de Elementos Finitos (MEF). O recente aumento da preocupação com a eficiência energética tem levado muitos países a implantarem legislações que impõem necessidades de aumento de eficiência de motores elétricos. Neste contexto, o motor LSPMSM se apresenta como alternativa aos motores de indução convencionais visando à diminuição do consumo de energia elétrica, por exemplo, em refrigeradores. No entanto, a exigência de alocação de uma grande área para o mancal e por consequência a retirada de materiais ferromagnéticos do rotor pode diminuir o desempenho do motor LSPMSM inviabilizando assim sua aplicação. Para a realização deste estudo, foi adotada uma metodologia de projeto disponível na literatura para estabelecer as etapas do projeto a ser realizado. Tal referência de projeto, embora elaborada para ser utilizada em um motor LSPMSM trifásico, foi utilizada em um projeto de motor monofásico. Os resultados do ensaio foram comparados com os dados obtidos via simulações computacionais de tal forma a validar o método proposto e também avaliar o impacto da retirada de material do rotor no desempenho final do motor. Os resultados práticos ficaram próximos aos resultados obtidos em simulação validando a utilização da metodologia também em motores monofásicos. Desta forma foi possível visualizar o efeito da área de mancal no rotor que devido ao aumento da relutância do circuito magnético alterou os resultados do valor da tensão induzida dos ímãs. / This work proposes a study about the influence of the bearing area allocation in hermetic compressors for refrigeration, considering a single phase Line Start Permanent Magnets Synchronous Motor, and employing conventional analytical calculations and the Finite Element Method (MEF). Recent increase in concern about energy efficiency has led many countries to roll out laws that impose requirements to raise the electric motor efficiency. In this context the LSPMSM motor is an alternative over conventional induction motors for the purpose of seeking power consumption reduction. However, the requirement to allocate a large area for the bearing and thus removal of ferromagnetic materials of the rotor can reduce LSPMSM motor performance what may impede its implementation. For the accomplishment of this study it was adopted a methodology of design available in the literature to set up the steps to be followed. Such design reference was at first described to be applied in three phase LSPMSM, however in this work it was applied in a single phase motor. Tests results were compared with data obtained via computer simulations in a way to validate the proposed method and to assess the impact of material removal from de rotor on the motor performance. The obtained bench test results were close to those simulated ones validating the methodology to be used in single phase motors too. Therefore, it was feasible to notice the influence of the counterbore area in the rotor, which, due to the increased value of the circuit reluctance, changed induced voltage values related to the magnets.

Este trabalho propõe uma investigação sobre a influência da alocação da área de mancal em compressores herméticos para a refrigeração, considerando um motor Síncrono de Ímãs Permanentes com Partida Direta na Rede (LSPMSM) monofásico, e utilizando cálculos analíticos convencionais e o Método de Elementos Finitos (MEF). O recente aumento da preocupação com a eficiência energética tem levado muitos países a implantarem legislações que impõem necessidades de aumento de eficiência de motores elétricos. Neste contexto, o motor LSPMSM se apresenta como alternativa aos motores de indução convencionais visando à diminuição do consumo de energia elétrica, por exemplo, em refrigeradores. No entanto, a exigência de alocação de uma grande área para o mancal e por consequência a retirada de materiais ferromagnéticos do rotor pode diminuir o desempenho do motor LSPMSM inviabilizando assim sua aplicação. Para a realização deste estudo, foi adotada uma metodologia de projeto disponível na literatura para estabelecer as etapas do projeto a ser realizado. Tal referência de projeto, embora elaborada para ser utilizada em um motor LSPMSM trifásico, foi utilizada em um projeto de motor monofásico. Os resultados do ensaio foram comparados com os dados obtidos via simulações computacionais de tal forma a validar o método proposto e também avaliar o impacto da retirada de material do rotor no desempenho final do motor. Os resultados práticos ficaram próximos aos resultados obtidos em simulação validando a utilização da metodologia também em motores monofásicos. Desta forma foi possível visualizar o efeito da área de mancal no rotor que devido ao aumento da relutância do circuito magnético alterou os resultados do valor da tensão induzida dos ímãs. / This work proposes a study about the influence of the bearing area allocation in hermetic compressors for refrigeration, considering a single phase Line Start Permanent Magnets Synchronous Motor, and employing conventional analytical calculations and the Finite Element Method (MEF). Recent increase in concern about energy efficiency has led many countries to roll out laws that impose requirements to raise the electric motor efficiency. In this context the LSPMSM motor is an alternative over conventional induction motors for the purpose of seeking power consumption reduction. However, the requirement to allocate a large area for the bearing and thus removal of ferromagnetic materials of the rotor can reduce LSPMSM motor performance what may impede its implementation. For the accomplishment of this study it was adopted a methodology of design available in the literature to set up the steps to be followed. Such design reference was at first described to be applied in three phase LSPMSM, however in this work it was applied in a single phase motor. Tests results were compared with data obtained via computer simulations in a way to validate the proposed method and to assess the impact of material removal from de rotor on the motor performance. The obtained bench test results were close to those simulated ones validating the methodology to be used in single phase motors too. Therefore, it was feasible to notice the influence of the counterbore area in the rotor, which, due to the increased value of the circuit reluctance, changed induced voltage values related to the magnets.

This thesis deals with thermal management aspects of electric machinery used in high-performance  applications  with  particular  focus put  on electric machines designed for hybrid electric vehicle applications. In the first part of this thesis,  new thermal models of liquid (water and oil) cooled electric machines are proposed.  The proposed thermal models are based on a combination of lumped parameter (LP)  and numerical methods. As  a first  case study,  a permanent-magnet  assisted  synchronous reluctance machine (PMaSRM) equipped with a housing water jacket is considered.  Particular focus is put on the stator winding and a thermal model is proposed that divides the stator slot into a number of elliptical copper and impregna- tion layers.  Additionally, an analysis, using results from a proposed simplified thermal finite element (FE)  model representing only a single slot of the sta- tor and its corresponding end winding, is presented in which the number of layers and the proper connection between the parts of the LP thermal model representing the end winding and the active part of winding are determined. The approach is attractive due to its simplicity  and the fact  that it closely models the actual temperature distribution for common slot geometries.  An oil-cooled induction machine where the oil is in direct contact with the stator laminations  is also considered.  Here, a multi-segment structure is proposed that  divides  the  stator,  winding and cooling  system  into  a number  of an- gular  segments.   Thereby,  the  circumferential  temperature  variation  due to the  nonuniform distribution  of the  coolant  in the  cooling  channels  can be predicted. In the  second part  of this  thesis,  the  thermal  impact  of using  different winding impregnation  and steel  lamination  materials  is  studied.   Conven- tional varnish, epoxy and a silicone based thermally conductive impregnation material are investigated and the resulting temperature distributions in three small induction machines are compared. The thermal impact of using different steel lamination materials is investigated by simulations using the developed thermal  model  of the water  cooled  PMaSRM. The  differences  in alloy con- tents and steel lamination thickness are studied separately and a comparison between the produced iron losses and the resulting hot-spot temperatures is presented. Finally, FE-based approaches  for  estimating  the  induced  magnet  eddycurrent losses in the rotor of the considered PMaSRM are reviewed and compared in the  form  of a case  study  based on simulations.   A  simplified three-dimensional  FE model  and an analytical  model,  both  combined  with time-domain 2D FE analysis, are shown to predict the induced eddy current losses with a relatively good accuracy compared to a complete 3D FE based model.  Hence, the two simplified approaches are promising which motivates a possible future experimental verification. / <p>QC 20130528</p>

Brushless Direct Current (BLDC) motors are one of the motor types rapidly gaining popularity. BLDC motors are being increasingly used in critical high performance industries such as appliances, automotive, aerospace, consumer, medical, industrial automation equipment and instrumentation. Fault detection and condition monitoring of BLDC machines is therefore assuming a new importance. The objective of this research is to advance the field of rotor and load fault diagnosis in BLDC machines operating in a variety of operating conditions ranging from constant speed to continuous transient operation. This objective is addressed as three parts in this research. The first part experimentally characterizes the effects of rotor faults in the stator current and voltage of the BLDC motor. This helps in better understanding the behavior of rotor defects in BLDC motors. The second part develops methods to detect faults in loads coupled to BLDC motors by monitoring the stator current. As most BLDC applications involve non-stationary operating conditions, the diagnosis of rotor faults in non-stationary conditions forms the third and most important part of this research. Several signal processing techniques are reviewed to analyze non-stationary signals. Three new algorithms are proposed that can track and detect rotor faults in non-stationary or transient current signals.

Η παρούσα διπλωματική εργασία πραγματεύεται τη διερεύνηση μεθόδου εξοικονόμησης ενέργειας σε ηλεκτροκίνητο όχημα, μέσω ελέγχου του κινηητήρα για την ελαχιστοποίηση των απωλειών του ηλεκτροκινητήριου συστήματος. Στη συγκεκριμένη περίπτωση, το ηλεκτροκινητήριο σύστημα αποτελείται από ασύγχρονο τριφασικό κινητήρα οδηγούμενο. από αντιστροφέα τάσης, ο οποίος τροφοδοτείται από συσσωρευτές. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών. Σκοπός της διπλωματικής αυτής εργασίας είναι η ανάπτυξη της μεθόδου εξοικονόμησης ενέργειας σε ηλεκτροκίνητο όχημα, μέσω ελαχιστοποίησης των απωλειών του συστήματος. Η ελαχιστοποίηση των απωλειών υλοποιείται μεταβάλλοντας τη μαγνητική ροή διακένου του ασύγχρονου κινητήρα και το λόγο μετάδοσης του κιβωτίου ταχυτήτων. Απώτερος στόχος είναι η επέκταση της μεθόδου ελαχιστοποίησης των απωλειών του ηλεκτροκινητήριου συστήματος που αναπτύχθηκε στη διδακτορική διατριβή του Ε.Ρίκου, "Μέθοδοι Εξοικονόμησης Ενέργειας σε Ηλεκτροκίνητα Οχήματα". Πανεπιστήμιο Πατρών, Τμήμα Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών, Πάτρα 2005, στην περίπτωση κινητήριου συστήματος με ασύγχρονο τριφασικό κινητήρα και αντιστροφέα και επιβεβαίωση της αποτελεσματικότητάς της σε θεωρητικό επίπεδο, επίπεδο προσομοίωσης και πειραματικό. Αρχικά, εξετάζονται οι σχέσεις που περιγράφουν τις απώλειες ισχύος που παράγονται κατά τη λειτουργία του ηλεκτροκίνητου οχήματος, καθώς και η εξάρτησή τους από τη μαγνητική ροή διακένου και το λόγο μετάδοσης του κιβωτίου ταχυτήτων. Στη συνέχεια, δείχνεται με γραφικό τρόπο η δυνατότητα ελαχιστοποίησης των απωλειών του συστήματος με τη μεταβολή της μαγνητικής ροής διακένου και του λόγου μετάδοσης για δεδομένες μόνιμες καταστάσης λειτουργίας (ταχύτητα και δύναμη στους τροχούς του οχήματος). Το επόμενο βήμα είναι η επιβεβαίωση της θεωρητικής μελέτης μέσω προσομοίωσης η οποία γίνεται σε περιβάλλον Matlab/ Simulink. Τέλος, κατασκευάζονται στο εργαστήριο πειραματική διάταξη με χρήση της οποίας διεξάγονται μετρήσεις για την επιβεβαίωση και αξιολόγηση της θεωρητικής μελέτης. / This diploma thesis discourses the analysis of an energy saving method in an electrically powered vehicle by control of the electric motor for the loss minimization of the electromotion system. In this case, the electromotion system consists of an induction motor, driven by a voltage inverter which is fed by batteries. This project was based in the Laboratory of Electromechanincal Energy Conversion of School of Engineering of University of Patras. The objective of this project is the development of the method for energy saving in an electrically powered vehicle, through system losses minimization. The loss minimization is carried out by controlling motor air-gap magnetic flux and gear ratio. The aim of the project is the extension of the electromotion system loss minimization method which was developed in the doctoral thesis of Evangelos Rikos, "Methods of energy saving in electric vehicles", University of Patras, department of Electrical and Computer Engineering, Patras 2005 for the case of a three phase induction motor and inverter electric drive, as well as the confirmation of its effectiveness in theoretical level, simulation and experimental level. At first, an analysis of the equations that describe the losses of the electric vehicle is performed as well as their dependence from the air-gap flux and gear ratio. Following, is graphically demonstrated the ability to minimize the losses of the electromotion system by controlling the air-gap flux and the gear ratio for certain steady states (values of force and velocity at the vehicle's wheels). The next step is the confirmation of the theoretical analysis by simulation which is carried out in Matlab/Simulink environment. Finally, a three phase inverter is constructed with the use of which, the experiment is carried out on order to confirm the efficiency and evaluate the accuracy of the theoretical analysis

Η παρούσα διδακτορική διατριβή εντάσσεται στο πλαίσιο που αφορά στο πεδίο ελέγχου συστημάτων ισχύος και ειδικότερα στην εφαρμογή προηγμένων μεθόδων στην ανάλυση και τον έλεγχο στρεφόμενων ηλεκτρικών μηχανών οδηγούμενων από ηλεκτρονικές διατάξεις ισχύος. Ειδικότερα, λαμβάνοντας υπόψη τα ακριβή μη γραμμικά μοντέλα των μετατροπέων ισχύος και των ηλεκτρικών μηχανών, αναλύεται η μορφή και η συμπεριφορά των ολοκληρωμένων συστημάτων που χρησιμοποιούνται για την οδήγηση των μηχανών και αποδεικνύεται ότι τα μοντέλα αυτά μπορούν να περιγραφούν με τη γενική παθητική Hamiltonian μορφή. Οι ηλεκτρονικές διατάξεις ισχύος που μελετώνται είναι ο μετατροπέας ΣΡ/ΣΡ ανύψωσης τάσης και ο τριφασικός μετατροπέας σε λειτουργία ανορθωτή και μετατροπέα, ενώ επίσης μελετώνται οι μηχανές ΣΡ ξένης διέγερσης και με διέγερση σε σειρά καθώς επίσης και η τριφασική επαγωγική μηχανή. Έχοντας αναπτύξει τα πλήρη μοντέλα, προτείνεται ένας νέος μη γραμμικός νόμος ελέγχου κατάλληλος για τη γενική παθητική Hamiltonian μορφή των συστημάτων τα οποία περιλαμβάνουν διακοπτικούς μετατροπείς ισχύος. Μια εκτενής μη γραμμική μαθηματική ανάλυση αποδεικνύει ότι ο προτεινόμενος νόμος ελέγχου εγγυάται ευστάθεια και σύγκλιση στο επιθυμητό σημείο ισορροπίας για το σύστημα κλειστού βρόχου. Ο έλεγχος αυτός εφαρμόζεται για τον έλεγχο κινητήρων ΣΡ οδηγούμενων από μετατροπέα ΣΡ/ΣΡ ανύψωσης τάσης καθώς και στην τριφασική επαγωγική μηχανή. Η ανάλυση και η εφαρμογή του ελέγχου οδηγεί στην ανάγκη για επεκτάσεις στη μορφή του ώστε να αυξηθεί η σθεναρότητά του ως προς τις αρχικές συνθήκες, να βελτιωθεί η μεταβατική του συμπεριφορά και να εφαρμοστεί κατάλληλα σε τριφασικούς μετατροπείς ισχύος ώστε να εγγυάται συγκεκριμένες λειτουργίες όπως γραμμική διαμόρφωση. Με την εφαρμογή του ελέγχου στην επαγωγική μηχανή, προτείνεται μια πλήρης σχεδίαση που λειτουργεί είτε βασιζόμενη στη λογική του προσανατολισμένου πεδίου, είτε πλήρως ανεξάρτητα από αυτή, ενώ μελετάται και η συμπεριφορά του σε καταστάσεις εξασθένησης πεδίου. Τέλος, η λογική του ελέγχου επιβεβαιώνεται σε ένα σύστημα ανεμογεννήτριας συνδεδεμένης στο δίκτυο μέσω πλήρους συστήματος μετατροπέων ισχύος με διασύνδεση συνεχούς ρεύματος. Σε όλες τις περιπτώσεις παρουσιάζονται προσομοιώσεις και κατά το δυνατό πειραματικά αποτελέσματα μέσω κατάλληλων εργαστηριακών διατάξεων. / The present PhD dissertation is addressed in the research field of control of power systems and more precisely in providing advanced methods for the analysis and control of electrical machines driven by power devices. Particularly, taking into account the accurate nonlinear models of the power converters and the electrical machines, the structure and the behavior of the complete models used for machine driving are analyzed based on the generalized Hamiltonian-passive form. The power converters discussed are the DC/DC boost converter and the three-phase power converter used as a rectifier or an inverter, while the separately-excited and the series-connected DC motors along with the three-phase induction machine are studied as well. After providing the complete dynamic models, a new nonlinear control scheme suitable for the generalized Hamiltonian-passive systems with switching devices is proposed. Using an extended mathematical analysis, it is proven that the proposed controller guarantees stability and convergence to the desired equilibrium for the closed-loop system. The proposed control application is tested for DC drive systems fed by DC/DC boost converters as well as for induction motor systems fed by AC/DC/AC converters. The control analysis and application leads to the extension of the control structure in order to increase the robustness with respect to the initial conditions, to improve the transient performance and to be suitably applied in three-phase power converter systems, guaranteeing simultaneously certain operating constraints such as linear modulation. For the case of the induction motor control, a complete form of the controller is proposed that acts either in the frame of field-orientation or independently from it, while the controller is also studied in field-weakening conditions. Finally, the controller performance is studied in a wind generating system connected to the grid through a full-scale power converter. In all cases, simulation results are presented while experimental results are provided where possible by using suitable laboratory testbeds.

La conception d'un microsystème de conversion d'énergie éolienne représente le cœur de cette étude. L'attention est dérivée vers le générateur sans balais à aimant permanent et auto-commutation, avec la configuration de rotor externe et des tensions électromotrices de forme trapézoïdale. L'objectif global de la thèse est représentée par la tentative de déterminer les paramètres optimaux de conception géométriques et électriques du générateur qui donne les plus faibles pertes totales dans le système, en fonctionnant sous un cycle du vent à long terme et ainsi en augmentant l'efficacité globale du système. En avance à l'optimisation, un modèle de simulation adapté doit être développé en termes de précision des résultats et du temps de simulation. Cela se fait dans la première partie de la thèse en déterminant le niveau de modélisation, ainsi que les variables de conception de chacun des composants du système. Comme l'optimisation fait appel à un algorithme pour le processus de conception, la réduction du temps de simulation a été étudiée dans la troisième et la quatrième partie de la thèse, en développant une méthode appropriée qui permet l'intégration et l'exploitation des données provenant du profil de vitesse du vent lors la détermination de la totalité des pertes de puissance du système. Par la suite, la méthode d'optimisation est présentée, même les résultats optimaux obtenus, ainsi que la comparaison de plusieurs paramètres d'entrée / sortie. Enfin, des essais expérimentaux sont également effectués sur un générateur de référence afin de vérifier la technique de commutation et de contrôle électronique. / The design of a micro-wind energy conversion system represents the core of this study. The attention is derived towards the brushless DC permanent magnet generator with outer rotor configuration and trapezoidal induced back-EMF voltages. The global aim of the thesis is represented by the attempt of determining the optimal geometrical and electrical design parameters of the BLDCPM generator that give the minimum total power losses in the system, over long-term wind speed cycle operation and thereby increasing the efficiency of the overall system. In advance to the optimization, an adapted simulation model needs to be developed in terms of results accuracy and simulation time. This is done in the first part of the thesis by determining the modeling level, as well as the design variables of each component of the system. As the optimization appeals to an algorithm for the design process, the reduction of the simulation time has been investigated in the third and fourth part of the thesis by developing a suitable method that allows the integration and exploitation of the available data from the wind-speed profile when determining the totality of the power losses in the system. Afterwards, the optimization methodology is presented along with the optimum results obtained, as well as comparison of several input/output parameters. Finally, experimental tests are also carried out on a reference BLDCPM machine prototype in order to verify its electronic commutation and control technique

This master thesis deals with the vibration diagnostics of machine vibrations during unit tests in industrial company Siemens Electric Machines s.r.o Drásov. In the master thesis is elaborated a design of the diagnostic system which contains selected methods of vibration diagnostics, methology, procedure of measurement and evaluation of measured values. The part of master thesis is also a practical example of measurement on which the mentioned system is tested.