More electric aircraft is an electrification scheme of aircraft system with high technical feasibility and good economy. It can reduce the weight of aircraft structure, improve maintenance efficiency and reduce fire hazards. However, the electrification of aircraft system will drastically increase the proportion of electrical equipment, the total power demand and the difficulty of fault diagnosis. This paper uses the energy management method to take up the challenge, with focus on fault diagnosis of permanent-magnet synchronous machines (PMSMs), adaptive load shedding and energy efficient aircraft design. A literature review of the concept evolution from all/more-electric aircraft to energy-optimized aircraft is presented. The main issues of the aircraft electrification process are summarized, and followed by an introduction to the current research and methods. The model of the aircraft electrical system is qualitatively and mathematically recalled, including the generator, the battery, the DC motor, the AC motor, and the electric power converter. The accuracy and computation cost of the aircraft model depends on the complexity of the subsystem models that are involved. Therefore, the level of detail that is necessary for a good precision-versus-simulation-time ratio is discussed by taking the electric system of an industrial level hybrid energy quadcoptor UAV as an example. The analysis shows that the bi-directional instruments, i.e. the electric machine, should be modeled in details while other components can be simplified. PMSMs are a group of on-board electric machines with promising future prospects because of high power density and stability. The model of PMSMs is further developed in this work, especially in the inter-turn and phase-to-phase short-circuit conditions. In case of inter-turn short-circuit fault, a winding-function-based and a fault-current-based model are separately developed. The accuracy of both models are verified and compared through experimental results. The fault-current-based modeling method is applied to the phase-to-phase short-circuit fault and experimentally examined and discussed. General condition monitoring methods require the use of a large number of sensors. A fault detection and isolation method that can have low requirement of sensor is recalled and inherited. The description of the fault phase identification index using this method is relatively imprecise, which is not applicable to the inter-turn short-circuit fault. In this work, the analytical expression of the faulty phase identification index is derived based on the fault models. A method to isolate inter-turn and phase-to-phase short-circuit faults is proposed by a combination of the current- and the voltage-signature residuals. This development expands the application scope of the original fault detection and isolation tool and improves its accuracy. The validity of this fault diagnosis method has been verified by experimental results.Load management is developed to guarantee the normal operation of critical loads by shedding some other loads in case of emergency. Generally, binary decisions are made: either something has gone wrong or everything is fine. However, different types of fault influence the working performance of the load and the entire network in different ways. There are multiple states between totally wrong and pure fine, and the load management decision should be adaptive to each state. In this work, fuzzy logic method is used to degrade the load priority according to the instantaneous working state. Combining it with the fault detection and isolation process, a fault-tolerant adaptive load management is achieved. Finally, this work discusses the aircraft design from the energy management point of view, which consists of the energy efficiency analysis and the multidisciplinary energy efficient design of the integrated aircraft system. The first thermodynamic efficiency has been widely used as a common parameter for depicting the energy utilization, i.e. the ratio of output to input power of the system. However, it ignores the irreversible increase of the entropy and cannot reveal the upper limit of the available work of the system.Based on the second thermodynamic law, this work uses the exergy parameters to analyze the energy utilization of a MEA design scheme. Based on the exergy analysis, an energy-efficient aircraft design method is proposed by optimizing the exergy lost of the whole design. The method could provide a global optimization reference for the integrated aircraft design of a MEA. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Ondulações de torque devido à comutação de fases é apontada como a principal desvantagem do método de controle 6 pulsos convencional do motor síncrono de ímã permanente no rotor com força contra-eletromotriz trapezoidal. Para reduzir essas ondulações, diferentes estratégias de controle vetorial dessa máquina são apresentadas na literatura. Nesse trabalho é proposto e analisado o controle vetorial dessa máquina utilizando uma malha de controle de corrente baseada no Finite Control-Set Model-based Predictive Control (FCS-MPC). Como resultado, a estrutura de controle vetorial proposta é capaz de reduzir as ondulações de torque de comutação e também aquelas provenientes de imperfeições da força contraeletromotriz trapezoidal. Esse resultado é atingido sem a alteração da estrutura do conversor, adição de circuito ou alteração na tensão de barramento. Em termos de desempenho dinâmico, são demonstradas a rápida dinâmica de torque sem necessidade de sintonia ou projeto de ganhos de controlador e dinâmica desacoplada das variáveis de controle sem necessidade de cálculo de termos de desacoplamento. Esses resultados apontam vantagens sobre recentes propostas na literatura baseada em controladores lineares. Também é implementado uma estratégia de melhoria de desempenho do FCS-MPC baseado na inclusão do conceito de ciclo de trabalho. Essa abordagem permite reduzir significativamente, em baixa velocidade, a banda de ondulação da corrente de estator e torque da máquina, demonstrando uma melhoria em relação ao FCS-MPC sem ciclo de trabalho. / Torque ripples due to phase commutation are pointed to the main drawback of 120 degree 6 step control of synchronous motor with trapezoidal back electromotive force (back EMF). To reduce these ondulations, different vector control strategies are presented in the literature. This study proposes and analyzes the application of the Finite Control-Set Model-based Predictive Control in the current loop of vector control strategy of permanent magnet synchronous motor with trapezoidal back EMF. As a result, the control structure reduces the torque ripple comming from phase commutation and back EMF shape imperfections. This result is achieved without changing the converter topology, the DC link voltage or including aditional circuit. Concerning to dynamic response, the proposed control strategy offers fast torque dynamics without gain tunning needed and decoupled dynamic of variable control. Furthermore, it is implemented an improvement approach to FCS-MPC based on duty-cycle concept. This strategy reduces significantly the torque ripple in low speed range, demonstrating an advance over conventional FCS-MPC.

A grande aplicação residencial de motores de indução monofásicos é em sistemas de refrigeração doméstica/comercial. O desenvolvimento de motores mais eficientes, associado ao controle de velocidade, fez com que, dentro os mais diversos tipos de motores, o motor síncrono de imã permanente tornasse objeto para a criação de uma metodologia de projeto, construção e realização de ensaios. Assim, para adequar o projeto do motor MSIP para substituição do motor de indução monofásico, foram feitos estudos de como aproveitar as laminações já existentes, através de definições das características básicas do estator e do rotor. O imã permanente a ser utilizado foi definido principalmente em função do custo do material e de suas propriedades magnéticas estarem adequadas à necessidade do projeto. O projeto magnético foi feito para maximizar o fluxo nos dentes, considerando as características construtivas e a curva de trabalho dos imãs. O projeto elétrico, a partir de um circuito equivalente do motor, permitiu explicar as relações de torque, corrente e tensão do motor MSIP, bem como a definição das bobinas do motor, quanto ao espaçamento destas entre as ranhuras, o cálculo do número de espiras e o diâmetro dos fios em função da área permitida pela ranhura da lamina do estator. Com as informações obtidas após o cálculo do motor MSIP, passou-se a construção de um protótipo constituído pelo estator, rotor e um sistema de suporte que permitisse o levantamento dos parâmetros do motor. Os parâmetros necessários foram definidos levando-se em consideração a necessidade para o projetista do conversor elétrico, sendo estes dados utilizados em simulações computacionais para a determinação do projeto do acionador. Com isto, os ensaios do motor MSIP permitiram o levantamento dos seguintes parâmetros: resistência, indutância, curvas de tensão de fase e linha da eletromotriz por velocidade em diversas rotações, momento de inércia e atrito viscoso, concluindo assim a proposta deste trabalho, e finalizando a metodologia para o motor MSIP. / A major residential application of single-phase induction motors is in domestic refrigeration. The development of more efficient motors, associated with speed control, has made that, among the most diverse types of electrical motors, the permanent magnet synchronous machine becomes an object of study for a design, construction and testing methodology. Therefore, to suit the PMSM design to replace the single phase induction motor, studies were made on how to take advantage of existing laminations, through definitions of the basic characteristics of the stator and rotor. The permanent magnet used was defined mainly as a function of the cost of the material and its magnetic properties since they suit the design requirements. PMSM magnetic design was made to maximize the magnetic flow in the slots considering the constructive characteristics and the magnet curve. The electric design, starting from a motor equivalent circuit, allowed to explain torque, current and voltage of the PMSM motor, as well as the definition of the motor windings regarding their filling in the slots, the calculation of coil number and the wire diameter as a function of the area allowed by the stator lamination slot. With the information obtained after the PMSM motor calculation, a prototype construction was initiated consisting of the stator, rotor and a support system to allow determining the motor parameters. The required parameters were defined taking into account the need the designer had of an electronic drive had. This data was used in computational simulations to determine the electronic driver design. After this, the motor testing allowed to identify the parameters, namely: winding resistance and inductance, various speed curves versus phase to phase and line voltage for back emf´s, moment of inertia and viscous friction, thus completing this work proposal, finalizing the project methodology for PMSM motor.

Este trabalho demonstra que o efeito de extremidade existente em atuadores eletromagnéticos lineares pode ter influência significativa nas indutâncias próprias, mútuas e síncronas, com valores dependentes da posição que podem ser utilizados para monitoração da posição axial da armadura. O estudo é aplicado a um atuador eletromagnético linear tubular de ímãs permanentes com duplo arranjo de quase-Halbach e bobina móvel, que foi concebido para fins de uso em sistemas de suspensão eletromagnética ativa e semi-ativa. A partir da revisão de literatura apresentada, classificou-se o efeito de extremidade de máquinas lineares síncronas de ímãs permanentes quanto aos tipos, causas, consequências e técnicas de mitigação (caso seja necessário). Adicionalmente, os tipos de controle sem sensores são exemplificados a fim de se identificar maneiras possíveis de adequar algum ao atuador em estudo. São apresentados casos de trabalhos na literatura que utilizam o controle sem sensores em máquinas que possuem indutâncias com comportamento semelhante. Em termos de análise, a distribuição do fluxo magnético no atuador é estudada e um modelo semianalítico é elaborado para calcular o valor das indutâncias com base nos dados de fluxo magnético obtido por simulação numérica. Logo, modelos numéricos completos e parametrizados do atuador são elaborados para simulação transiente e magnetostática e a partir destes as indutâncias são obtidas. As indutâncias também são medidas experimentalmente e na análise dos resultados as incertezas de medição são calculadas e um projeto de experimento é apresentado. Os resultados dos modelos semianalítico e numérico apresentam boa concordância com os resultados experimentais. Por fim, a adequação do atuador para futura aplicação de controle sem sensores é discutida tendo como base a variação de indutâncias devido ao efeito de extremida. / This work demonstrates that the end effect in linear electromagnetic actuators can have a significant influence on the self-, mutual and synchronous inductances, with positiondependent values that can be used to measure the axial position of the armature. The study is applied to a linear synchronous electromagnetic actuator with two arrangements of quasi- Halbach permanent magnets and moving coil, which was designed for use in active and semiactive electromagnetic suspension systems. Based on the literature review presented, the end effect of permanent magnet synchronous linear machines was classified with regard to: types, causes, consequences and mitigation techniques (if necessary). In addition, the types of sensorless control methods are exemplified in order to identify a possible method to be applied to the actuator under study. It was found in the literature that sensorless control was applied to machines that have inductances with similar behavior. In terms of analysis, the distribution of the magnetic flux in the actuator is studied and a semi-analytical model was developed to calculate the value of the inductances based on the data of magnetic flux obtained through numerical simulation. Thus, the complete parametrized numerical models of the actuator were built for transient and magnetostatic simulation, and from these the inductances were obtained. The inductances are also measured experimentally, and in the analysis of the results the measurement uncertainties are calculated and a design of experiments is presented. The results of the semi-analytical and numerical models show good agreement with the experimental results. Finally, the suitability of the actuator for future application of sensorless control is discussed based on the variation of inductances due to the end effect.

Le transport routier est au cœur des enjeux environnementaux actuels. Les véhicules électriques hybrides (VEH) sont une alternative intéressante, notamment en milieu urbain. Cependant, la conception de tels systèmes est complexe car la chaîne de traction (composants et architecture), la mission et la gestion énergétique du véhicule sont intimement liées.Les travaux de V. Reinbold ont permis de mettre au point une méthodologie de dimensionnement de VEH. Les composants sont optimisés conjointement avec la gestion énergétique sur un cycle de fonctionnement afin de minimiser la consommation de carburant du véhicule. Une attention particulière est portée à la conception fine de la machine électrique via un modèle électromagnétique adapté à l’optimisation.Dans la suite de ces travaux, nous approfondissons plusieurs aspects du dimensionnement des VEH. Tout d’abord, nous introduisons la possibilité de gérer des paramètres discrets de la machine, comme le nombre de paires de pôles. Dans un second temps, nous développons un modèle thermique de la machine prenant notamment en compte les échanges autour des têtes de bobine. Ce modèle analytique par réseau de résistances thermiques est intégré puis utilisé dans le processus de dimensionnement par optimisation. Il a été préalablement validé via un modèle par éléments finis. Des méthodes d’analyse d’incertitude et de sensibilité sont appliquées afin de quantifier l’influence de certains paramètres thermiques. Enfin, nous appliquons la méthodologie de dimensionnement par optimisation à une architecture série/parallèle, intégrant deux machines électriques. / Road transportation has a huge impact on the environment. Hybrid electric vehicles (HEV) are an interesting alternative, especially for urban uses. However, HEV are complex systems to design because of the strong interaction between the component sizing, the energy management and the driving cycle.V. Reinbold previously developed a sizing methodology for HEV. The components and the energy management are simultaneously optimized to reduce the fuel consumption of the vehicle over a driving cycle. A specific electromagnetic model is used during the optimization process to describe accurately the electrical machine.As a continuation, we introduce firstly the possibility to deal with discrete variables such as the pole number of the electrical machine. Then, we develop a thermal model of the machine considering the convection exchanges around the end-windings. This analytical lumped parameter thermal network is used during the optimization process after being validated thanks to a finite element model. Uncertainty and sensitivity analysis are used to check the influence of some of the thermal parameters. Finally, the sizing methodology is applied to a series/parallel HEV including two electrical machines.

A grande aplicação residencial de motores de indução monofásicos é em sistemas de refrigeração doméstica/comercial. O desenvolvimento de motores mais eficientes, associado ao controle de velocidade, fez com que, dentro os mais diversos tipos de motores, o motor síncrono de imã permanente tornasse objeto para a criação de uma metodologia de projeto, construção e realização de ensaios. Assim, para adequar o projeto do motor MSIP para substituição do motor de indução monofásico, foram feitos estudos de como aproveitar as laminações já existentes, através de definições das características básicas do estator e do rotor. O imã permanente a ser utilizado foi definido principalmente em função do custo do material e de suas propriedades magnéticas estarem adequadas à necessidade do projeto. O projeto magnético foi feito para maximizar o fluxo nos dentes, considerando as características construtivas e a curva de trabalho dos imãs. O projeto elétrico, a partir de um circuito equivalente do motor, permitiu explicar as relações de torque, corrente e tensão do motor MSIP, bem como a definição das bobinas do motor, quanto ao espaçamento destas entre as ranhuras, o cálculo do número de espiras e o diâmetro dos fios em função da área permitida pela ranhura da lamina do estator. Com as informações obtidas após o cálculo do motor MSIP, passou-se a construção de um protótipo constituído pelo estator, rotor e um sistema de suporte que permitisse o levantamento dos parâmetros do motor. Os parâmetros necessários foram definidos levando-se em consideração a necessidade para o projetista do conversor elétrico, sendo estes dados utilizados em simulações computacionais para a determinação do projeto do acionador. Com isto, os ensaios do motor MSIP permitiram o levantamento dos seguintes parâmetros: resistência, indutância, curvas de tensão de fase e linha da eletromotriz por velocidade em diversas rotações, momento de inércia e atrito viscoso, concluindo assim a proposta deste trabalho, e finalizando a metodologia para o motor MSIP. / A major residential application of single-phase induction motors is in domestic refrigeration. The development of more efficient motors, associated with speed control, has made that, among the most diverse types of electrical motors, the permanent magnet synchronous machine becomes an object of study for a design, construction and testing methodology. Therefore, to suit the PMSM design to replace the single phase induction motor, studies were made on how to take advantage of existing laminations, through definitions of the basic characteristics of the stator and rotor. The permanent magnet used was defined mainly as a function of the cost of the material and its magnetic properties since they suit the design requirements. PMSM magnetic design was made to maximize the magnetic flow in the slots considering the constructive characteristics and the magnet curve. The electric design, starting from a motor equivalent circuit, allowed to explain torque, current and voltage of the PMSM motor, as well as the definition of the motor windings regarding their filling in the slots, the calculation of coil number and the wire diameter as a function of the area allowed by the stator lamination slot. With the information obtained after the PMSM motor calculation, a prototype construction was initiated consisting of the stator, rotor and a support system to allow determining the motor parameters. The required parameters were defined taking into account the need the designer had of an electronic drive had. This data was used in computational simulations to determine the electronic driver design. After this, the motor testing allowed to identify the parameters, namely: winding resistance and inductance, various speed curves versus phase to phase and line voltage for back emf´s, moment of inertia and viscous friction, thus completing this work proposal, finalizing the project methodology for PMSM motor.

Ondulações de torque devido à comutação de fases é apontada como a principal desvantagem do método de controle 6 pulsos convencional do motor síncrono de ímã permanente no rotor com força contra-eletromotriz trapezoidal. Para reduzir essas ondulações, diferentes estratégias de controle vetorial dessa máquina são apresentadas na literatura. Nesse trabalho é proposto e analisado o controle vetorial dessa máquina utilizando uma malha de controle de corrente baseada no Finite Control-Set Model-based Predictive Control (FCS-MPC). Como resultado, a estrutura de controle vetorial proposta é capaz de reduzir as ondulações de torque de comutação e também aquelas provenientes de imperfeições da força contraeletromotriz trapezoidal. Esse resultado é atingido sem a alteração da estrutura do conversor, adição de circuito ou alteração na tensão de barramento. Em termos de desempenho dinâmico, são demonstradas a rápida dinâmica de torque sem necessidade de sintonia ou projeto de ganhos de controlador e dinâmica desacoplada das variáveis de controle sem necessidade de cálculo de termos de desacoplamento. Esses resultados apontam vantagens sobre recentes propostas na literatura baseada em controladores lineares. Também é implementado uma estratégia de melhoria de desempenho do FCS-MPC baseado na inclusão do conceito de ciclo de trabalho. Essa abordagem permite reduzir significativamente, em baixa velocidade, a banda de ondulação da corrente de estator e torque da máquina, demonstrando uma melhoria em relação ao FCS-MPC sem ciclo de trabalho. / Torque ripples due to phase commutation are pointed to the main drawback of 120 degree 6 step control of synchronous motor with trapezoidal back electromotive force (back EMF). To reduce these ondulations, different vector control strategies are presented in the literature. This study proposes and analyzes the application of the Finite Control-Set Model-based Predictive Control in the current loop of vector control strategy of permanent magnet synchronous motor with trapezoidal back EMF. As a result, the control structure reduces the torque ripple comming from phase commutation and back EMF shape imperfections. This result is achieved without changing the converter topology, the DC link voltage or including aditional circuit. Concerning to dynamic response, the proposed control strategy offers fast torque dynamics without gain tunning needed and decoupled dynamic of variable control. Furthermore, it is implemented an improvement approach to FCS-MPC based on duty-cycle concept. This strategy reduces significantly the torque ripple in low speed range, demonstrating an advance over conventional FCS-MPC.

Η παρούσα διπλωματική εργασία πραγματεύεται τη μελέτη, το σχεδιασμό και την εξομοίωση ενός σύγχρονου κινητήρα μόνιμου μαγνήτη οδηγούμενο από ελεγχόμενο τριφασικό αντιστροφέα. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών. Σκοπός λοιπόν της παρούσας εργασίας είναι η μελέτη και προσομοίωση ενός σύγχρονου κινητήρα μόνιμου μαγνήτη μέσω της μεθόδου των πεπερασμένων στοιχείων, με τη βοήθεια του λογισμικού Opera σε δύο διαστάσεις (2d). Στο περιβάλλον σχεδίασης κυκλωμάτων του ίδιου προγράμματος, μοντελοποιήθηκε και ο τριφασικός αντιστροφέας ισχύος για την οδήγηση του κινητήρα. Στην συνέχεια, έγινε διασύνδεση του λογισμικού Opera με το πρόγραμμα Simulink του λογισμικού Matlab, με απώτερο σκοπό να επιτευχθεί έλεγχος κλειστού βρόχου της ταχύτητας περιστροφής του κινητήρα Συγκεκριμένα, έγινε μελέτη και προσομοίωση ενός συγκεκριμένου 8πολικού κινητήρα τύπου Brushless DC, ονομαστικής ισχύος 660 W, ονομαστικής τάσης 48 V, και ονομαστικής ταχύτητας 3000 rpm ο οποίος τροφοδοτήθηκε στην είσοδό του με τριφασικό αντιστροφέα. Ιδιαίτερη προσοχή δόθηκε, στην εξομοίωση του τρόπου λειτουργίας των αισθητήρων Hall, μέσω των ημιαγωγικών διακοπτικών στοιχείων του αντιστροφέα, τα οποία ρυθμίστηκαν για να λειτουργούν σε κατάλληλες, για την υπό μελέτη μηχανή, χρονικές περιόδους. Κρίσιμη ήταν επίσης, η διαδικασία εύρεσης των κατάλληλων κερδών των ελεγκτών PI, έτσι ώστε να βελτιωθεί η μεταβατική απόκριση του συστήματος κλειστού βρόχου και να μειωθεί το σφάλμα μόνιμης κατάστασης ταχύτητας. Αναλυτικά, στο κεφάλαιο 1 γίνεται αναφορά στα θεμελιώδη μεγέθη του μαγνητικού πεδίου, καθώς και στις ιδιότητες των μαγνητικών υλικών που χρησιμοποιούνται στην κατασκευή σύγχρονων μηχανών μόνιμου μαγνήτη. Στο κεφάλαιο 2 αναλύονται οι σύγχρονοι κινητήρες μόνιμου μαγνήτη και γίνεται εκτενής αναφορά στα κατασκευαστικά χαρακτηριστικά, στη βασική αρχή λειτουργίας και στις μαθηματικές εξισώσεις που τους περιγράφουν. Στο κεφάλαιο 3 περιγράφεται η διάταξη οδήγησης του κινητήρα και αναλύονται λεπτομερώς η λειτουργία και του αντιστροφέα και του κυκλώματος ελέγχου κλειστού βρόχου. Στο κεφάλαιο 4 περιγράφεται η διαδικασία διεξαγωγής μετρήσεων και σχεδιασμού του μοντέλου πεπερασμένων στοιχείων της μηχανής στο περιβάλλον του υπολογιστικού προγράμματος Opera-2d. Στο κεφάλαιο 5 περιγράφεται η διαδικασία σχεδιασμού του τριφασικού αντιστροφέα και παρουσιάζονται τα αποτελέσματα εξομοίωσης για το σύστημα ανοικτού βρόχου. Στο κεφάλαιο 6 εξηγείται η διαδικασία διασύνδεσης των δύο προγραμμάτων (Matlab-Opera) και παρουσιάζονται τα αποτελέσματα της εξομοίωσης για το σύστημα ελέγχου κλειστού βρόχου. / In this dissertation, the design and simulation of a permanent magnet synchronous motor driven by a three-phase inverter, is presented. The work was conducted at the Laboratory of Electromechanical Energy Conversion, Department of Electrical and Computer Engineering, University of Patras. The objective of this dissertation is the study and simulation of a permanent magnet synchronous motor employing the finite element method, with the help of Opera-2d simulation software. In the Circuit Editor environment of the same software, a three-phase inverter for driving the motor was designed, utilizing the PWM method and achieving open loop control of the motor rotation speed under constant loads. In addition, a closed loop control system was designed on Simulink user interface of Matlab software and making use of the interconnection capability of the two programs (Matlab-Opera) closed loop control of the motor rotation speed was achieved. Specifically, chapter 1 gives reference to fundamentals of the magnetic field and the magnetic properties of materials used in the construction of modern permanent magnet machines. Chapter 2 analyzes synchronous permanent magnet motors and makes an extensive reference to the constructional features, basic operation principle and the mathematical equations that describe them. Chapter 3 describes the motor driving converter and analyzes in detail the operation of the inverter and the closed loop control circuit. Chapter 4 describes the procedure for carrying out measurements and designing the finite element model of the machine in the environment of Opera-2d software. Chapter 5 describes the three-phase inverter design process and presents the simulation results for the open loop system. Chapter 6 explains the interconnection process of the two programs (Matlab-Opera) and presents the results of the simulation for the closed loop control system.

The McTronX research group, at the Potchefstroom campus of the North–West University, has been researching Active Magnetic Bearings (AMBs). A fully suspended, flywheel energy storage system (FESS) has been developed. Due to excessive unbalance on the rotor, the motor drive could not be tested up to its rated speed. In the interim, until the rotor can be balanced and other rotor dynamic effects have been investigated, the group decided that the existing drive control should be improved and tested on a high–speed permanent magnet synchronous motor (PMSM), using normal roller element bearings. In order to test the motor control a second (identical) PMSM, mechanically coupled to the former, operates in generator mode which serves as the torque load. Two different control algorithms, namely V/f and vector control, are designed and implemented on a rapid control prototyping system, i.e. dSPACE®. The V/f control is an open–loop, position sensorless technique, whilst the vector controller makes use of a position sensor. From the design and implementation it became clear that the vector control is more robust, in the sense that it is less sensitive on parameter variations and disturbances. It can start up reliably even under full load conditions. The V/f control is an attractive alternative to the vector control, especially in AMB systems, where it may be difficult to mount the position sensor, has to operate in a hazardous environment not suited to the sensor or could degrade the reliability of the AMB system. The cost of the position sensor is not really a concern compared to the cost of an AMB system. The V/f control is more suited to fan and pump applications, which has a low dynamic requirement. The V/f control has high startup currents and is not recommended for applications requiring a high starting torque or fast acceleration during operation. The inverter, which drives the PMSM, also had to be developed. With regard to the motor control, the effects of inverter non–idealities had to be accounted, especially for the V/f control. The implemented control algorithms were tested up to 20 krpm. Discrepancies between the expected and actual results are discussed. Overall, the controllers performed as desired. Generally, the project goals have been reached satisfactorily. / Thesis (M.Ing. (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2011.

The McTronX research group, at the Potchefstroom campus of the North–West University, has been researching Active Magnetic Bearings (AMBs). A fully suspended, flywheel energy storage system (FESS) has been developed. Due to excessive unbalance on the rotor, the motor drive could not be tested up to its rated speed. In the interim, until the rotor can be balanced and other rotor dynamic effects have been investigated, the group decided that the existing drive control should be improved and tested on a high–speed permanent magnet synchronous motor (PMSM), using normal roller element bearings. In order to test the motor control a second (identical) PMSM, mechanically coupled to the former, operates in generator mode which serves as the torque load. Two different control algorithms, namely V/f and vector control, are designed and implemented on a rapid control prototyping system, i.e. dSPACE®. The V/f control is an open–loop, position sensorless technique, whilst the vector controller makes use of a position sensor. From the design and implementation it became clear that the vector control is more robust, in the sense that it is less sensitive on parameter variations and disturbances. It can start up reliably even under full load conditions. The V/f control is an attractive alternative to the vector control, especially in AMB systems, where it may be difficult to mount the position sensor, has to operate in a hazardous environment not suited to the sensor or could degrade the reliability of the AMB system. The cost of the position sensor is not really a concern compared to the cost of an AMB system. The V/f control is more suited to fan and pump applications, which has a low dynamic requirement. The V/f control has high startup currents and is not recommended for applications requiring a high starting torque or fast acceleration during operation. The inverter, which drives the PMSM, also had to be developed. With regard to the motor control, the effects of inverter non–idealities had to be accounted, especially for the V/f control. The implemented control algorithms were tested up to 20 krpm. Discrepancies between the expected and actual results are discussed. Overall, the controllers performed as desired. Generally, the project goals have been reached satisfactorily. / Thesis (M.Ing. (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2011.