Submitted by Maria Suzana Diniz (msuzanad@hotmail.com) on 2015-11-06T15:48:55Z No. of bitstreams: 1 arquivototal.pdf: 3791340 bytes, checksum: 58dd4dde93f8552a891a0760151a7c10 (MD5) / Made available in DSpace on 2015-11-06T15:48:55Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3791340 bytes, checksum: 58dd4dde93f8552a891a0760151a7c10 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The interest for the study of multiphase (more than three phases) machines and variable speed drives has substantially increased in the last two decades. The advantages presented by the multiphase systems compared to their three-phase counterparts have being the the main effort to increase researches all over the world. Reduction in torque oscillation, lower current ratings, high drive reliability, better fault tolerance and harmonic content reduction in the DC bus are some of these advantages. The additional degrees of freedom due to extra phases make multiphase systems very flexible when it comes to control systems and modulation strategies. Although three-phase systems are predominant in industrial applications, the use of multiphase machines and drives has increased in very specific areas such as locomotive traction, electric ship propulsion, aerospace industry (more electric aircraft), electric and hybrid vehicles and industrial high power systems. Due to high coupling degree between electric variables in multiphase systems, modeling of multiphase machines has been and still is a challenge task in research centers. In this present work, analitic modeling of symmetric and asymmetric nine-phase machines using natural variables and space vector decomposition are presented. The principles used in the study are the same used for three-phase systems. However, multiphase systems are analised in multiple d-q planes. PWM modulation strategies based on space vectors theory (SVPWM) for a voltage source inverter (VSI) are presented. The multiphase drive system presented works in the linear operation region with sinusoidal voltage generation. Results for both machines and drive modeled are verified by simulation programs developed in C programming language an Matlab. / O interesse pelo estudo de máquinas de indução multifases (mais de três fases) e dos seus sistemas de acionamento cresceu substancialmente nas últimas duas décadas. As muitas vantagens apresentadas pelos sistemas multifases, em relação aos sistemas trifásicos convencionais, têm sido fatores motivadores para o aumento de pesquisas em todo o mundo. Redução das oscilações de torque, redução da corrente por fase, maior confiabilidade do acionamento, grande tolerância à faltas e redução no conteúdo harmônico da corrente no barramento CC são algumas destas vantagens. O maior grau de liberdade proporcionado pelas fases extras torna os sistemas multifases bastante flexíveis quanto às estratégias de modulação e de controle. Apesar da atual predominância da utilização das máquinas e acionamentos trifásicos na indústria, as máquinas multifases estão sendo cada vez mais utilizadas em áreas de aplicações específicas tais como tração de locomotivas, propulsão de navios elétricos de grande porte, indústria aeroespacial, tração de veículos híbridos e elétricos e sistemas industriais de alta potência. Devido ao alto grau de acoplamento entre as variáveis elétricas de um sistema multifases, a modelagem e análise desses sistemas tem representado uma tarefa desafiadora nos centros de pesquisa. No presente trabalho são apresentadas as modelagens analíticas de uma máquina de indução de nove fases simétrica e de uma máquina de nove fases assimétrica pelo método de variáveis naturais e pelo método de decomposição vetorial. Os princípios utilizados na modelagem são os mesmos utilizados nos sistemas trifásicos. No entanto, sistemas multifases são analisados em múltiplos planos d-q. Estratégias de modulação PWM baseadas na teoria de vetores espaciais (SVPWM) para um inversor de nove fases tipo VSI (Inversor Fonte de Tensão) são apresentadas para acionamento das máquinas. O sistema de acionamento apresentado trabalha na região linear de operação e gera tensão de saída senoidal. Dados de simulação obtidos a partir de programas desenvolvidos em linguagem C e Matlab são apresentados para ambas as máquinas de nove fases modeladas.

The demand for ultra-high-speed machines (UHSM) is rapidly growing in high-tech industries due to their attractive features. A-mechanically-based-antenna (AMEBA) system is another emerging application of UHSM. It enables portable wireless communication in the radio frequency (RF)-denied environment, which was not possible until recently. The AMEBA system requires a high-power (HP) UHSM for its effective communication performance. However, at the expected rotational speed range of 0.5 to 1 million rpm, the power level of UHSM is limited, and no research effort has succeeded to improve the power level of UHSM. The design of HP-UHSM is highly iterative, and it presents several critical challenges, unlike low-power UHSM, such as critical-bending-resonance (CBR), strong mutual influence among Multiphysics performances, exponential air-friction loss, and material limitation. When the magnetic loading of the UHSM rotor is increased to improve the power level, the rotor experiences serious mechanical vibration due to the excessive centrifugal forces and CBR. This vibration limits the operation of HP-UHSM and leads to structural breakdown. Furthermore, the design process becomes more critical when it considers the multidisciplinary design constraints and application requirements. This dissertation proposed a new Multiphysics design method to develop HP-UHSM for critical applications. First, the critical design constraints which prevent increasing the output power of UHSM are investigated. Then, a Multiphysics optimization model is developed by coupling several multidisciplinary analysis modules. This proposed optimization model enables (i) defining multidisciplinary design constraints, (ii) consideration of Multiphysics mutual influence, and (iii) a trade-off analysis between the efficiency and design-safety-margin. The proposed design model adopts the multiphase winding system to effectively increase the electrical loading in the slotless stator. Finally, a 2000 W 500,000 rpm HP-UHSM is optimized for an AMEBA system using the proposed design method. The optimized 2 kW 500,000 rpm machine prototype and its dynamo setup are built in the laboratory. Extensive finite element simulations and experimental testing results are presented to validate the effectiveness of the proposed design method. The results show that the proposed HP-USHM has 94.5% efficiency, 47 kW/L power density, 30% global design safety margin at the maximum speed and no CBR frequency below 11 kHz.

L'objectif de la thèse est la conception d'une machine électrique dédiée à des applications Mild-Hybrid. En assurant certaines fonctionnalités, cette machine permet de réduire la consommation de carburant dans le véhicule et par conséquent réduire la quantité des gaz rejetés. Les contraintes exigées par un tel domaine à la fois pour le couple et la puissance nous amène à étudier les machines synchrone polyphasée à aimants avec un bobinage concentré autour des dents. Cette technologie de bobinage permet d'obtenir des machines de rendement élevé qui sont faciles à fabriquer, réparer et recycler, mais avec un certain niveau d'effets parasites. Afin de trouver un compromis entre ces effets et la capacité à fournir de couple, la thèse concerne l'étude des topologies de bobinage à pas dentaire avec différentes combinaisons Encoches/Pôles. Un modèle analytique constituant un outil permettant de comparer les pertes d'aimants entre les différentes combinaisons est développé. De nombreuses configurations sont comparées afin de faire le choix le plus adéquat pour minimiser les effets parasites. Les topologies rotoriques qui permettent à la machine de présenter une large plage de vitesse sont examinées, mais en tenant compte également de la nécessité de protéger leurs aimants contre des harmoniques nocifs de FMM. Enfin, l'exploitation du degré de liberté offert par une structure à 5 phases est abordée montrant que, le couple peut être significativement boosté en modifiant la structure de rotor. La cohérence de toutes les études analytiques menées dans la thèse est corroborée par des modèles en éléments finis et des mesures effectuées sur un prototype. / The aim of this thesis is to design an electrical machine dedicated for Mild-Hybrid applications. By providing certain functionalities, this machine can reduce fuel consumption in the vehicle and therefore reduce the amount of released gases. The challenges imposed by such application on both torque and power lead us to study the multiphase PM machines with concentrated windings. This windings technology provides efficient machines which are easy to manufacture, repair and recycle, but accompanied with a certain level of parasitic effects. In order to find a compromise between these effects and the ability to provide torque, the thesis concerns the study of winding topologies with different Slots/Poles combinations. An analytical model constituting a tool to compare magnet losses between various combinations is developed. Many configurations are compared in order to make the most appropriate choice which minimizes parasitic effects. The rotor topologies that allow the machine to provide a wide speed range are examined, taking into account their role in magnets protection against MMF harmful harmonics. Finally, the exploitation of freedom degree offered by a 5-phases structure is discussed, showing that the torque can be significantly boosted by modifying the rotor structure. The consistency of all analytical studies presented in the thesis is corroborated by finite element models and a prototype measurement.

Wound Independently Controlled Stator Coil (WICSC) machines are a novel type of multiphase machine with the ability to change its pole-phase configuration during operation. This enables improved post-fault control and thus prolonged continuous operation. For a smooth transition to post-fault control, a quick and robust strategy for Fault detection and isolation (FDI) is essential. This master thesis concerns the design of a procedure to localise Open Phase Fault (OPF) and Open Switch Fault (OSF) in WICSC machines. The strategy is based on Harmonic Plane Decomposition (HPD), which generalises Vector Space Decomposition (VSD) to variable pole-phase machines. A previous iteration of the FDI strategy is analysed and developed further on MatLab. Experimental verification is performed on a WICSC motor with and without imitated OPF. A Printed Circuit Board (PCB) is designed to imitate OSF during operation. The outcome displays a fault detection within less than 30% of a fundamental current period. After no more than one period the full diagnosis is completed. Although only OPFs are tested, the results suggest the Fault detection and isolation (FDI)’s ability to identify OSFs as well. The parameter tuning is shown to be important for both correct fault localisation and avoiding false positives. Imbalances in the machine require special care when choosing the parameter values. Future work includes using the PCB for OSF tests and making the parameter tuning more robust. / WICSC-maskiner är en ny typ av multifasmaskin med förmågan att ändra sin polfas-konfiguration under drift. Detta möjliggör förbättrad reglering efter att fel uppstår och därmed förlängd drift. För att uppnå en mjuk övergång till reglering efter fel krävs en snabb och robust strategi för feldiagnosticering. Denna masteruppsats rör utvecklingen av en strategi för att detektera och lokalisera tomgångsfel i spolar och elektroniska brytare till WICSC-maskiner. Strategin baseras på HPD, som är en generalisering av VSD. En tidigare iteration av strategin analyseras och vidareutvecklas i MatLab. Experimentell verifiering utförs på en WICSC-motor med samt utan imiterade tomgångsfel i spolarna. En PCB designas för att imitera tomgångsfel i växelriktarens brytare. Resultaten ger en feldetektering på under 30% av en fundamental strömperiod. Efter maximalt en period är hela diagnosticeringen slutförd. Trots att endast spolfel testas pekar resultaten på att strategin även fungerar för brytarfel. Strategins parametervärden visar sig vara viktiga för både fellokaliseringen och för att undvika falska positiv. Obalans i maskinen ställer särsklit höga krav på justeringen av dessa värden. I framtida studier kommer PCB-enheten användas för att testa diagnosticering av brytarfel och göra justeringen av parametervärdena mer robust.