The need for efficiency, reliability and continuous operation has lead over the years to the development of fault-tolerant electrical drives for various industrial purposes and for transport applications. Permanent-magnet synchronous machines have also been gaining interest due to their high torque-to-mass ratio and high efficiency, which make them a very good candidate to reduce the weight and volume of the equipment.<p><p>In this work, a multidisciplinary approach for the design of fault-tolerant permanent-magnet synchronous machine drives is presented. <p><p>The drive components are described, including the electrical machine, the IGBT-based two-level inverter, the capacitors, the sensors, the controller, the electrical source and interfaces. A literature review of the failure mechanisms and of the reliability model of most of these components is performed. This allows understanding how to take benefit of the redundancy generally introduced in fault-tolerant systems.<p><p>A necessary step towards fault tolerance is the modelling of the electrical drive, both in healthy and faulty operations. A general model of multi-phase machines (with a number of phases equal to or larger than three) and associated converters is proposed. Next, control algorithms for multi-phase machines are derived. The impact of a closed-loop controller upon the occurrence of faults is also examined through simulation analysis and verified by experimental results.<p><p>Condition monitoring of electrical machines has expanded these last decades. New techniques relying on various measurements have emerged, which allow a better planning of maintenance operations and an optimization of the uptime of electrical machines. Regarding drives, a number of sensors are inherently present for control and basic protection functions. The utilization of these sensors for advanced condition monitoring is thus particularly interesting since they are available at no cost. <p><p>A novel fault detection and isolation scheme based on the available measurements (phase currents, DC-link voltage and mechanical position) is developed and validated experimentally. Change-detection algorithms are used for this purpose. Special attention is paid to sensor faults as well, what avoids diagnosis errors.<p><p>Fault-tolerant control can be implemented with passive and active approaches. The former consists in deriving a control scheme that gives acceptable performance for all operating conditions, including faulty conditions. The latter consists in applying dedicated solutions upon the occurrence of faults, i.e. by reconfiguring the control. Both approaches are investigated and implemented. <p><p>Finally, design considerations are discussed throughout the thesis. The advantages and drawbacks of various topologies are analyzed, which eventually leads to the design of a five-phase fault-tolerant permanent-magnet synchronous machine. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Ce mémoire de thèse s'inscrit dans le cadre du programme « avion plus électrique », il comprend deux parties.La première est consacrée à la présentation détaillée du contexte, c'est-à-dire du processus qui conduit à électrifier la plupart des systèmes présents dans l'avion, un exemple d'actionneur électromécanique spécifique, conçu dans ce cadre sera aussi détaillé notamment pour ce qui concerne son mode d'alimentation. La seconde partie, plus longue, est consacrée à différents processus de fiabilisation de structures d'électroniques de puissance. Du fait de l'électrification croissante de l'avion, ces structures vont se multiplier à bord, mais la fiabilité connue de ces dispositifs n'est pas apte à satisfaire aux exigences de l'aéronautique. Les processus de fiabilisation, dans leur majorité, sont orientés, en cas de panne, vers un isolement de la source du défaut, pour permettre un fonctionnement en mode dégradé, supporté par le système. Par ailleurs, un dispositif de sécurisation de bras d'onduleur est décrit : un sectionneur commandé à thyristors et fusible (SCTF2). Ce système permet d'isoler électriquement le bras d'onduleur victime d'un défaut au sein d'un onduleur triphasé. L'emplacement de prédilection du SCTF2 est la connexion bras d'onduleur et bus continu d'alimentation. Les simulations de ce système de fiabilisation sont menées sur PSIM. Ce mémoire propose des modélisations approchées, pour l'outil de CAO adopté, des composants IGBT et fusibles, lorsque ces derniers sont soumis à un régime de courant extrême (court-circuit). / This manuscript of thesis was written in two parts for the "More Electric Aircraft" program. The first part presents in great detail the context of the thesis that is (i.e) the processes which allow electrifying the most of classic aircraft-systems. In this part, an example of special electromechanical actuator build in the More Electric aircraft program will be presented with meticulous care, in particular its command and supply systems. The second part, more extensive, is devoted to various solutions which improve the reliability of the power-electric systems. With the growth of the electrification of the aircrafts, several solutions of this kind will be multiplicated on board, but today most of these solutions haven't the reliability intended to the aeronautical applications. For the most part, the reliability processes consist in isolating the origins of a breakdown, in order that the system can continue to work in a debased mode. In addition, a system which protects inverter's legs is described; it's a controlled circuit breaker which uses thyristors and fuses (SCTF2). This system of reliability allows electrical isolating of faulty inverter's leg in a three phase inverter. The preferential position of a SCTF2 is the connexion between inverter's leg and the DC bus. Simulations of the SCTF2 are done on PSIM software. For PSIM, this manuscript poposes some approximative modelisations of the components like IGBT and fuse when they are subjected to a dangerous high-current (short-circuit).