Depuis des années, les avionneurs sont engagés pour la réduction de l’empreinte environnementale à travers le développement de nouveaux concepts. Ainsi, le remplacement des systèmes hydrauliques (hydraulicless) et pneumatiques (bleedless) de l’avion par des systèmes électriques sont envisagés d’où l’apparition du concept d’avion « plus électrique ». Toutefois, les gains espérés (diminution du coût, de la consommation de carburant ou de la masse) suite à cette substitution ne sont pas si faciles à obtenir, car les technologies précédentes ont bénéficié de plusieurs dizaines d’années de développement et d’optimisation. Les solutions électriques nouvellement proposées doivent donc elles aussi être très abouties pour être véritablement concurrentielles ; tous les degrés de liberté doivent être envisagés, qu’il s’agisse des technologies ou des architectures. En particulier, l’usage d’un nouveau réseau HVDC (540 V) semble être une solution prometteuse. A partir de ce réseau HVDC, les différentes charges AC triphasées sont alimentées par une série d’onduleurs génériques. Compte tenu de la disparité des consommations pendant les différentes phases de vol, le même onduleur peut servir à alimenter plusieurs charges. La connexion entre les onduleurs et les charges est gérée par une matrice de contacteurs. Cette solution innovante considère également des cas de redondance pour augmenter la robustesse de la solution. La conception de ce nouveau système est présentée dans ce rapport de thèse. Le compromis optimal entre le nombre d’onduleurs et la puissance nominale de chaque onduleur doit être obtenu. Ce choix déterminera fortement la taille de la matrice de contacteurs. Cependant, pour adresser cette problématique, il est nécessaire de connaître la masse des différents composants en fonction de la puissance requise. Un environnement de conception est ainsi créé dans le but de réaliser le dimensionnement optimal de convertisseurs de puissance. Les différents composants sont décrits utilisant une approche « directe » et sont codés sous le formalisme « orienté-objet ». Ces modèles sont ensuite validés expérimentalement ou par simulation numérique. Les différents modèles sont couplés à un environnement d’optimisation et à un solveur fréquentiel qui permet une résolution rapide des formes d’ondes du régime permanent. L’environnement d’optimisation réalise le dimensionnement précis des différentes parties de l’onduleur : dissipateur, module de puissance, filtre côté continu et inductance de couplage. Un onduleur est proposé pour différentes puissances nominales et fréquences de découpage. L’optimisation adresse également le choix des différentes technologies. Finalement, les résultats sont utilisés pour déterminer le meilleur compromis entre nombre d’onduleurs et puissance de l’onduleur à partir d’un algorithme heuristique. / In recent years, aircraft manufacturers have been making progress in the design of more efficient aircrafts to reduce the environmental footprint. To attain this target, aircrafts manufactures work on the replacement of the hydraulic and bleed systems for electrical systems leading to a “More Electrical Aircraft”. However, the expected mass gain is a challenge, as previous technologies have been developed and optimized for decades. The new electrical solutions need to be look into detail to be competitive with previous technologies. All degrees of freedom must be considered, that is, new technologies and architectures. In particular, an HVDC network that reduces the number of rectifier stages seems a promising solution. From the HVDC network, the different three phase AC loads will be supplied by a series of power generic inverters. As the power consumption of the different loads change during the flight mission, the same inverter is used to supply different loads. The connection between the inverters and the loads is managed by a matrix of contactors. The proposed solution also considers redundant configurations, thus increasing system robustness. The design of the innovative system is presented in this document. That is, determining the optimal trade-off between the number of power inverters and the nominal power of each generic inverter that will also impact the size of the matrix of contactors. However, to assess the combinatory problem, the mass of the different components as a function of the nominal power needs to be calculated. A design environment is therefore created to perform automatic and optimized design of power converters. The different components are described using a “direct modelling” approach and coded using “object-oriented” programming. The components are validated experimentally or by numerical simulations. The different models are coupled to an optimization environment and to a frequency solver allowing a fast calculation of the steady-state waveforms. The optimization environment performs the precise design of the different parts of the power inverter: heatsink, power module, DC filter and coupling inductor. The power inverter is designed for different values of nominal power and switching frequency. The optimization assesses as well the usage of different technologies. Finally, the results are used to determine the optimal trade-off between the number of inverters and the nominal power of each inverter using a heuristic algorithm.

Dans le contexte de l'avion plus électrique, de nouveaux défis technologiques apparaissent dans le développement des systèmes embarqués afin d'augmenter leur puissance électrique. Une optimisation visant la sécurité, l'efficacité énergétique et une diminution du volume et de la masse est ainsi nécessaire. A cet effet, les dispositifs doivent être considérés dans leur ensemble et non par éléments séparés. Pour faciliter l'intégration des systèmes de puissance et assurer la qualité du réseau de bord avion, cette thèse propose de tenir compte de la mission de vol et d'étudier la CIO « Conception Intégrée Optimale » du système complet comprenant le filtre d'entrée et l’onduleur de tension alimentant l'actionneur synchrone à aimants permanents haute vitesse « HSPMSM ». L'application est dédiée au système de conditionnement d'air cabine « ECS – Environmental Conditioning Systems » comprenant le compresseur d'air étudié, d'une puissance nominale de 70 kW. La thèse est structurée en trois parties principales: le dimensionnement des composants de la chaîne de conversion électromécanique ; la conception locale et séquentielle de chacun des composants du système (boucle d'optimisation actionneur puis boucle d'optimisation « onduleur de tension + filtre d'entrée » ; la conception simultanée de tous les composants du système (boucle d'optimisation globale). Les fronts « Pareto-optimaux » des solutions obtenues à partir des méthodes de conception séquentielles et simultanées sont présentés, analysés et comparés. Les résultats mettent clairement en évidence l'avantage d'utiliser une boucle d'optimisation unique pour l'amélioration de la masse et de l'efficacité énergétique du système. / The concept of More Electric Aircraft (MEA) implies new challenges especially due to the increase of the electrical embedded power. By this way, necessary improvements in terms of safety, energy efficiency and weight reduction are required. For this reason, the design of devices should be more approached with a view to the whole system than as separated elements. In order to facilitate power system integration and to ensure power quality aboard, this dissertation proposes an Integrated Optimal Design (IOD) of the input filter and the inverter feeding the High Speed Permanent Magnet Synchronous Motor (HSPMSM) by taking the flight mission into account. The Environmental Conditioning System (ECS) is equipped of the studied cabin air compressor with a rated power of 70 kW: a Multiobjective Genetic Algorithm (MOGA) is applied to achieve the CIO process. Considering the ECS as a whole, this thesis can be divided into three main parts: components sizing of the electromechanical conversion chain; local and sequential design of each system components (HSPMSM optimization loop followed by “voltage source inverter + input filter” optimization loop); simultaneous design of all system components (global optimization loop). Pareto-optimal solutions obtained from sequential and simultaneous design approaches are presented, analyzed and compared. Results clearly highlight the advantage of using a single optimization loop for the whole system in order to improve mass and efficiency.

Dans le domaine de l'aéronautique, les concepts basés sur l’usage étendu de l'électricité dans les aéronefs plus électriques (MEA) et même tout électriques (AEA) font appel à des actionneurs électromécaniques (EMA) en replacement des actionneurs servo-hydrauliques conventionnels (HSA). Lorsque les EMA sont utilisés pour des applications d'actionnement critique comme les commandes de vol, certains problèmes spécifiques liés à l’équilibre thermique, l'inertie réfléchie, le mouvement parasite dû aux élasticités structurelles, la réponse aux fautes (grippage et rupture) et la synchronisation d’EMA actifs sur charges indépendantes ne peuvent être ignorés. La simulation apporte un support indéniable à la conception pour l’évaluation et la validation des concepts. A cet effet, il est nécessaire de développer des prototypes virtuels des EMA avec une vision système et de façon structurée pour répondre aux besoins des ingénieurs. Malheureusement, les phénomènes physiques qui apparaissent dans les EMA sont multidisciplinaires, couplés et fortement non linéaires. De nombreux logiciels commerciaux de simulation système multi-domaines sont désormais disponibles. Cependant, le processus de modélisation et les besoins des ingénieurs sont rarement pris en compte selon une vision globale, en raison du manque d'approches scientifiques pour la définition d’architectures, la modélisation incrémentale et l’amélioration de l’implémentation numérique des modèles. Dans cette thèse, le prototypage virtuel de l'EMA est adressé en utilisant le formalisme Bond-Graph. De nouvelles approches sont proposées pour permettre la modélisation incrémentale de l'EMA en vue de fournir des modèles pour la synthèse de la commande, l’évaluation de la consommation d'énergie, l'analyse thermique, le calcul des forces de réaction, la simulation de la pollution du réseau d'alimentation électrique, la réponse aux fautes et l'influence de la température. L’intérêt des modèles proposés est illustré sur l’exemple de la synchronisation de position de deux EMA actionnant des charges indépendantes. / In the aerospace field, the concepts based on extended use of electricity in “More Electric Aircraft” (MEA) and even “All Electric Aircraft” (AEA), involve electromechanical actuators (EMAs) to replace conventional hydraulic servo actuators (HSAs). When EMAs are used for safety-critical actuation applications like flight controls, some specific issues related to thermal balance, reflected inertia, parasitic motion due to compliance, response to failure (jamming and free-run) and synchronization of EMAs driving independent loads cannot be ignored. The simulation-aided design process can efficiently support the assessment and validation of the concepts fixing these issues. For that, virtual prototypes of EMAs at system-level have to be developed in a structured way that meets the engineers’ needs. Unfortunately, the physical effects governing the EMAs behavior are multidisciplinary, coupled and highly nonlinear. Although numerous multi-domain and system-level simulation packages are now available in the market of simulation software, the modelling process and the engineers’ needs are rarely addressed as a whole because of lack of scientific approaches for model-based architecting, multi-purpose incremental modelling and model implementation for efficient numerical simulation. In this thesis, the virtual prototyping of EMAs is addressed using the Bond-Graph formalism. New approaches are proposed to enable incremental modelling of EMAs that provides models supporting control design, energy consumption and thermal analysis, calculation of reaction forces, power network pollution simulation, prediction of response to faults and influence of temperature. The case of preliminary design of EMAs position synchronization is used to highlight the interests and advantages of the proposed process and models of EMAs.

In the past two decades the core aircraft technology is going through a drastic change. The traditional technologies that is almost half a century old, is going through a complete revamp. In the new “More Electric Aircraft” technology many mechanical, pneumatic and hydraulic systems are being replaced by electrical and power electronic systems. Airbus-A380, Boeing B-787 are the pioneers in the family of these new breed of aircrafts. As the aircraft technology is moving towards “More Electric”, more and more electric motors and motor controllers are being used in new aircrafts. Number of electric motor drive systems has increased by about ten times in more electric aircrafts compared to traditional aircrafts. Weight of any electric component that goes into aircraft needs to be low to reduce the overall weight of aircraft so as to improve the fuel efficiency of the aircraft. Hence there is an increased need to reduce weight of motors and motor controllers in commercial aircraft. High speed ironless axial flux permanent magnet brushless dc motors are becoming popular in the new more-electric aircrafts because of their ability to meet the demand of light weight, high power density, high efficiency and high reliability. However, these motors come with very low inductance, which poses a big challenge to the motor controllers in controlling the ripple current in motor windings. Multilevel inverters can solve this problem. Three-level inverters are proposed in this thesis for driving axial flux BLDC motors in aircraft. Majority of the motors in new more electric aircrafts are in the power range of 2kW to 20kW, while a few motor applications being in the range of 100kW to 150kW. Motor controllers in these applications run from 270Vdc or 540Vdc bus which is the standard in new more electric aircraft architecture. Multilevel Inverter is popular in the industry for high power and high voltage applications, where high-voltage power switching devices like IGBT, GTO are popularly used. However multilevel inverters have not been tried in the low power range which is appropriate for aircraft applications. A detail analysis of practical feasibility of constructing three-level inverter in lower power and voltage level is presented in this thesis. Analysis is presented that verify the advantages of driving low voltage and low power (300Vdc to 600Vdc and less than 100kW) motors with multilevel inverters. Practical considerations for design of MOSFET based three-level inverter are investigated and topological modifications are suggested. The effect of clamping diodes in the diode clamped multilevel inverters play an important role in determining its efficiency. SiC diodes are proposed to be used as clamping diodes. Further, it is realised that power loss introduced by reverse recovery of MOSFET body diode prohibits use of MOSFET in hard switched inverter legs. Hence, a technique of avoiding the reverse recovery losses of MOSFET body diode in three-level NPC inverter is conceived. The use of proposed multilevel inverter topology enables operation at high switching frequency without sacrificing efficiency. High switching frequency of operation reduces the output filter requirement, which in turn helps reducing size of the inverter. In this research work elaborate trade-off analysis is done to quantify the suitability of multilevel inverters in the low power applications. For successful operation of three-level NPC inverter in aircraft electrical system, it is important for the DC bus structure in aircraft electric primary distribution system to be compatible to drive NPC inverters. Hence a detail study of AC to DC power conversion system as applied to commercial aircraft electrical system is done. Multi-pulse rectifiers using autotransformers are used in aircrafts. Investigation is done to improve these rectifiers for future aircrafts, such that they can support new technologies of future generation motor controllers. A new 24-pulse isolated transformer rectifier topology is proposed. From two 15º displaced 6-phase systems feeding two 12-pulse rectifiers that are series connected, a 24-pulse rectifier topology is obtained. Though, windings of each 12-pulse rectifiers are isolated from primary, the 6-phase generation is done without any isolation of the transformer windings. The new 24-pulse transformer topology has lower VA rating compared to standard 12-pulse rectifiers. Though the new 24-pulse transformer-rectifier solution is robust and simple, it adds to the weight of the overall system, as compared to the present architecture as the proposed topology uses isolated transformer. Non-isolated autotransformer cannot provide split voltage at the dc-link that creates a stable mid-point voltage as required by the three-level NPC inverter. Hence, a new front-end AC-DC power conversion system with switched capacitor is conceived that can support motor controllers driven by three-level inverters. Laboratory experimental results are presented to validate the new proposed topology. In this proposed topology, the inverter dc-link voltage is double the input dc-link voltage. An intense research work is performed to understand the operation of Trapezoidal Back EMF BLDC motor driven by three-Level NPC inverter. Operation of BLDC motor from three-Level inverter is primarily advantageous for low inductance motors, like ironless axial flux motors. For low inductance BLDC motor, very high switching frequency is required to limit the magnitude of ripple current in motor winding. Three-level inverters help limiting the magnitude of motor ripple current without increasing the switching frequency to very high value. Further, it is analysed that dc link mid-point current in three-level NPC inverter for driving trapezoidal BLDC motor has a zero average current with fundamental frequency same as switching frequency. Because of this, trapezoidal BLDC motors can easily be operated from three-level NPC inverter without any special attention given to mid-point voltage unbalance. One non-ideal condition arrives in practical implementation of the inverter that leads to non-zero average mid point current. Unequal gate drive dead time delays from one leg to other leg of inverter introduce dc-link mid-point voltage unbalance. For the motoring mode operation of trapezoidal BLDC motor drive, simple gate drive logic is researched that eliminates need of the gate drive dead-time, and hence solves the mid-point voltage unbalance issue. Simple closed loop control scheme for mid-point voltage balancing also is also proposed. This control scheme may be used in applications where very precise control of speed and torque ripple is warranted. All the investigations reported in this thesis are simulated extensively on MATHCAD and MATLAB platform using SIMULINK toolbox. A laboratory experimental set-up of three-Level inverter driving axial flux BLDC motor is built. The three-level inverter, operating from 300Vdc bus is built using 500V MOSFETs and 600V SiC diodes. All the control schemes are implemented digitally on digital signal processor TMS320F2812 DSP platform and GAL22V10B platforms. Experimental results are collected to validate the theoretical propositions made in the present research work. At the end, in chapter 5, some future works are proposed. A new external voltage balance circuit is proposed where the inverter dc-link voltage is same as the input dc-link voltage. This topology is based on the resonant converter principle and uses a lighter resonant inductor than prior arts available in literature. Detail simulation and experimentation of this topology may be carried out to validate the industrial benefits of this circuit. It is also thought that current source inverters may work as an alternative to voltage source inverters for driving BLDC motors. Current source inverters eliminate use of bulky DC-link capacitors. Long term reliability of current source inverters is higher than voltage source inverters due to the absence of possibility of shoot-through. Further, in voltage source inverters, the voltage at the motor terminal is limited by the source voltage (dc-link voltage). This issue is eliminated in current source inverters. An interface circuit is conceived to reduce the size of dc-link inductors in current source inverters, pending detail analysis and experimental verification. The interface circuit bases its fundamentals on the principles of operation of multilevel inverters for BLDC motors that is presented in this thesis.

Future more electric aircraft (MEA) architectures require a new generation of power-by-wire actuators, e.g. Electro Hydrostatic Actuators (EHA). These units have to be capable of frontline operation of safety critical flight control surfaces over the entire aircraft life. Prove of robustness becomes a challenging objective. This paper illustrates the Liebherr-Aerospace EHA technology as well as methods for validation of robustness. It gives an insight regarding the design of a robust piston pump.

Les avionneurs expriment le besoin de développement de l’avion plus « électrique ». Cela se traduit par des besoins nouveaux en matière de systèmes de motorisation électrique, en termes de puissance à fournir et de partage de ressources matérielles en vue de minimiser la masse embarquée et les coûts. Parmi les études en cours sur l’évolution des machines tournantes, un intérêt particulier porte sur le développement des alterno-démarreurs de type machines synchrones sans balais et à plusieurs étages (BSSG). Celles-ci sont susceptibles de fournir un fort couple lors des phases de démarrage des réacteurs auxquelles elles sont associées. Pour ce faire, la connaissance, à tout moment, de la position du rotor est essentielle. Cependant, l'ajout d’un capteur dédié impacte la conception de la machine, rajoutant du volume, du câblage et augmentant le coût. La réalisation d'une commande dite « sensorless » permettrait de s'affranchir de l'utilisation d'un tel capteur et de simplifier le design des alterno-démarreurs.A partir d'une modélisation fine de la machine, cette thèse étudie les conditions dans lesquelles une telle commande est réalisable et analyse plusieurs techniques permettant d'y parvenir. Une nouvelle méthode d'estimation de la position du rotor, spécifique aux BSSG est proposée, puis illustrée avec des résultats expérimentaux. Cette technique est basée sur le traitement des composantes harmoniques existantes naturellement au stator de la machine et permet l'estimation de la position à l'arrêt et à très basse vitesse. Afin d'étendre l'estimation sur toute la plage de vitesse, une étude d'estimation de position par un observateur d'état à base du modèle complet de la machine en considérant les harmonique injectés (ou existantes) dans les courants du stator est proposée. Cet observateur peut s’appliquer à la machine synchrone à trois étages mais aussi à toute machine synchrone. Dans cette étude, son fonctionnement est illustré sur une machine synchrone à aimants permanents. / The aircraft manufacturers express the need to develop a more "electric" aircraft. This brings forward new requirements for the electric drive systems in terms of increasing the available on-board power and resource sharing in order to optimize the overall mass and cost. Among the ongoing studies on the evolution of motor drives, a particular interest is given to the development of multi-level brushless synchronous starter/generators (BSSG). These drives are likely to provide the high torque required to start-up the reactors to which they are associated. For this purpose, the knowledge, at any time, of the rotor position is essential. However, adding a dedicated sensor impacts on the design of the machine, increasing volume, cabling needs and cost. For this purpose, investigating on “sensorless” control laws will permit to avoid using such a sensor and to simplify the design of the Starter/Generators.Using a fine modelling of the machine, this work studies the conditions of feasibility for sensorless control and analyzes several techniques for this purpose. A new method of estimation of the shaft-position, particular to the BSSG architecture is proposed and then illustrated with experimental results. This technique is based on the processing of the existing harmonic components naturally in the stator of the machine and allows the estimation of the position at standstill and the very low speed. To extend the estimation to the whole speed range, a study of position estimation using a state observer using the complete model of the machine considering the knowledge of the existing (or injected) harmonic components in the stator currents is proposed. This observer can be applied to the brushless synchronous starter/generator but also on generic synchronous machines. In this study, its performance is illustrated on a permanent magnet synchronous machine.

Enhancing performance of power electronics converters has always been an interesting topic in the power electronics community. Over the years, researchers and engineers are developing new high performance component, novel converter topologies, smart control methods and optimal design procedures to improve the efficiency, power density, reliability and reducing the cost. Besides pursuing high performance, researchers and engineers are striving to modularize the power electronics converters, which provides redundancy, flexibility and standardization to the end users. The trend of modularization has been seen in photovoltaic inverters, telecommunication power supplies, and recently, HVDC applications. A systematic optimal design approach for modular power converters is developed in this dissertation. The converters are developed for aerospace applications where there are stringent requirement on converter form factor, loss dissipation, thermal management and electromagnetic interference (EMI) performance. This work proposed an optimal design approach to maximize the nominal power of the power converters considering all the constraints, which fully reveals the power processing potential. Specifically, this work studied three-phase active front-end converter, three-phase isolated ac/dc converter and inverter. The key models (with special attention paid to semiconductor switching loss model), detailed design procedures and key design considerations are elaborated. With the proposed design framework, influence of key design variables, e.g. converter topology, switching frequency, etc. is thoroughly studied. Besides optimal design procedure, control issues in paralleling modular converters are discussed. A master-slave control architecture is used. The slave controllers not only follow the command broadcasted by the master controller, but also synchronize the high frequency clock to the master controller. The control architecture eliminates the communication between the slave controllers but keeps paralleled modules well synchronized, enabling a fully modularized design. Furthermore, the implementation issues of modularity are discussed. Although modularizing converters under form factor constraints adds flexibility to the system, it limits the design space by forbidding oversized components. This work studies the influence of the form factor by exploring the maximal nominal power of a double-sized converter module and comparing it with that of two paralleled modules. The tradeoff between modularity and performance is revealed by this study. Another implementation issue is related to EMI. Scaling up system capacity by paralleling converter modules induces EMI issues in both signal level and system level. This work investigates the mechanisms and provides solutions to the EMI problems. / Ph. D. / As penetration of power electronics technologies in electric power delivery keeps increasing, performance of power electronics converters becomes a key factor in energy delivery efficacy and sustainability. Enhancing performance of power electronics converters reduces footprint, energy waste and delivery cost, and ultimately, promoting a sustainable energy use. Over the years, researchers and engineers are developing new technologies, including high performance component, novel converter topologies, smart control methods and optimal design procedures to improve the efficiency, power density, reliability and reducing the cost of power electronics converters. Besides pursuing high performance, researchers and engineers are striving to modularize the power electronics converters, enabling power electronics converters to be used in a “plug-and-play” fashion. Modularization provides redundancy, flexibility and standardization to the end users. The trend of modularization has been seen in applications that process electric power from several Watts to Megawatts. This dissertation discusses the design framework for incorporating modularization into existing converter design procedure, synergically achieving performance optimization and modularity. A systematic optimal design approach for modular power converters is developed in this dissertation. The converters are developed for aerospace applications where there is stringent v requirement on converter dimensions, loss dissipation, and thermal management. Besides, to ensure stable operation of the onboard power system, filters comprising of inductors and capacitors are necessary to reduce the electromagnetic interference (EMI). Owning to the considerable weight and size of the inductors and capacitors, filter design is one of the key component in converter design. This work proposed an optimal design approach that synergically optimizes performance and promotes modularity while complying with the entire aerospace requirement. Specifically, this work studied three-phase active front-end converter, three-phase isolated ac/dc converter and three-phase inverter. The key models, detailed design procedures and key design considerations are elaborated. Experimental results validate the design framework and key models, and demonstrates cutting-edge converter performance. To enable a fully modularized design, control of modular converters, with focus on synchronizing the modular converters, is discussed. This work proposed a communication structure that minimizes communication resources and achieves seamless synchronization among multiple modular converters that operate in parallel. The communication scheme is demonstrated by experiments. Besides, the implementation issues of modularity are discussed. Although modularizing converters under form factor constraints adds flexibility to the system, it limits the design space by forbidding oversized components. This work studies the impact of modularity by comparing performance of a double-sized converter module with two paralleled modules. The tradeoff between modularity and performance is revealed by this study.

In More Electric Aircraft, different power system activities are attributed to electrical means such as the start-up of the main engine. In this context, the study of the sensorless control of the Brushless Synchronous Starter Generator (BSSG) that is used to electrically start the main engine is revealed to be a very interesting issue. For long time, the elimination of the mechanical sensor was highly recommended for reliability, cost, weight, integration issues.Hence, this work aims to transpose the results obtained in the research area to an avionic testbench. It presents an adaptive sensorless technique to use when electrically starting the main engine of the aircraft. This is achieved by elaborating three different methods selected depending on the speed of the machine and based on the :- injection of a high frequency signal- use of the back-emf of the Permanent Magnet Generator (PMG)- use of the extended Kalman Filter EKFIn this work, it is shown that the …first method gives good position estimation results from standstill up to 8% of the rated speed. Then, the back-emfs of the PMG are used to detect the position of the BSSG when the speed exceeds the 8% of the rated speed. Good results are observed with this method at medium and high speed.For redundancy reasons, the EKF was also used in this work. Thus, the estimated position can be delivered via two different estimation algorithms in medium and high speed region.The implementation of the algorithm was achieved on an FPGA board since the latter can ensure a very tiny execution time. The fastness of the treatment ensures quasi-instantaneous position estimation and does not practically introduce any phase lag in the position estimation. / Aujourd'hui, l'aviation est en train de vivre des évolutions technologiques concernant surtout l'attribution de différentes fonctionnalités aux équipements électriques et ceci au détriment d'équipements hydrauliques et mécaniques assurant les mêmes fonctionnalités.Dans le cadre de l'avion plus électrique, le démarrage électrique sans capteurs mécaniques de la turbine de l'avion préoccupe les avionneurs de nos jours. Les problèmes introduits par ce capteur ont été identifiés : problèmes de coût et de poids, problèmes de fiabilité et d'intégration.Ce travail présente alors une commande sans capteurs pour la machine synchrone à trois étages à utiliser durant le démarrage électrique de l'avion. Ceci est réalisé avec trois méthodes de détection de la position selon la vitesse de rotation, basées sur :- l'injection d'un signal à haute fréquence- l'utilisation d'un filtre de Kalman étendu FKE- les fém. du PMG (Permanent Magnet Generator) La première méthode donne de bons résultats d'estimation depuis l'arrêt jusqu'à 8% de la vitesse nominale de la machine. Au-delà de cette vitesse, es valeurs des fém. du PMG deviennent assez élevées pour être utilisées dans l'estimation de la position. De bons résultats sont obtenus à moyenne et haute vitesse.Pour des questions de redondance, le FKE est aussi utilisé. Ainsi, la position estimée peut être fournie par l'un des deux algorithmes à moyenne et haute vitesse.L'implémentation de ces algorithmes est réalisée via une carte FPGA étant donné que celui-ci garantit un temps d'exécution. La rapidité de traitement garantit une estimation de la position quasi-instantanée et donc n'introduit pratiquement pas des retards dans l'estimation.

La thèse porte sur la caractérisation expérimentale des pertes singulières dans les matériaux magnétiques au sein d’actionneurs électromécaniques conçus pour le développement du programme « avion plus électrique », où la maîtrise des pertes d’énergie est un enjeu absolument majeur. Ce programme, de portée mondiale, vise, entre autre, à remplacer, dans l’avion, les actionneurs hydrauliques par des actionneurs électromécaniques, quand c’est possible.Par pertes singulières on entend toutes les pertes liées aux contraintes magnéto-mécano-thermiques liées d’une part à la mise en œuvre (découpe, assemblage contraint, isolation, traitement thermique...) des matériaux et d’autre part aux conditions réelles de fonctionnement (champ tournant, haute fréquence, saturations locales...) au sein des machines électriques (HV/HF), et qui sont très difficiles à estimer précisément de façon analytique ou via les dispositifs conventionnels de tests. Ces sollicitations influencent les caractéristiques de tôles qui peuvent s’éloigner significativement des données du fabricant (donc fausser le calcul des performances).Au début de cette thèse on s’est focalisé sur le montage d’un banc d’essai évolutif équipé de moyens de mesure directe du couple et d’une machine d’entraînement (8 ktr/min ; 42 kW) tarée par nos soins. Sur cette dernière une longue campagne d’essais a été menée pour isoler les différentes composantes de pertes, dont, par exemple, les pertes mécaniques (par frottement dans les roulements + aérodynamiques) qui ont été quantifiées via un rotor neutre. Les pertes dans les aimants sont indissociables des pertes fer, donc, elles ont été estimées par le biais d’une modélisation par éléments finis tridimensionnelle. Les pertes dans la frette de maintien sont nulles du fait qu’elle est isolante (thermo-rétractable). Le bobinage utilisé dans ce moteur est très particulier, à barres massives (remplissage de cuivre dans l’encoche jusqu’à 90%), développé dans notre laboratoire IES. Les pertes atypiques au sein de ce bobinage spécial ont été profondément abordées dans ces travaux (effet de refoulement de courants, pertes aux extrémités de la machine...).Dans la dernière partie de cette thèse, nous avons exploré le fonctionnement des machines synchrones à aimants à haute fréquence afin d’accroître la densité de puissance de nos moteurs (pour franchir la barre de 2.5 kW/kg). Pour ce faire, après une étude détaillée, nous avons proposé en premier lieu un prototype avec des matériaux standard (stator FeCo Vacodur49 0.2mm, rotor FeSi, aimants NdFeB nuance N35EH, bobinage à barres cuivre) fonctionnant à 1666 Hz, tournant à 5000 tr/min, avec une densité de puissance de 4.5 kW/kg et un rendement de 94%. En second lieu, nous avons proposé un deuxième prototype de rendement plus faible (93%) mais qui a une densité de puissance proche de 6 kW/kg avec un rotor sans fer et un bobinage en Aluminium.Avant le montage final de ce prototype modulaire, nous avons effectué des mesures de pertes magnétiques, en conditions réelles de fonctionnement d’un moteur électrique, sur une multitude de tôles FeSi et FeCo (Vacodur49, NO20, M270-35A) avec la variation de différents procédés de fabrication: isolation (vernis thermo-collant « back-lack », vernis C5), découpe (laser, électroérosion) et traitement thermique. Pareillement, toutes les pertes mises en jeu ont été séparées (mécaniques, par courants induits dans les viroles...) pour pouvoir remonter aux pertes magnétiques et, donc, enfin, quantifier empiriquement le coefficient de majoration de pertes fer. / The main aim of this thesis was to study and experimentally assess the additional iron losses in the stator (electrical lamination steel) of high performance permanent magnet synchronous machines (PMSM) designed for aircraft applications, in relation with the “more-electric-aircraft” project. This international program consists of gradually introducing electrical systems to replace onboard hydraulic and pneumatic systems, for example to power the landing gear wheels (Electric Green Taxiing System)…The extra iron losses are caused by manufacturing processes (cutting, sticking, insulation, stacking, pressing, shrink-fitting, thermal treatment …) and the real conditions of use of electrical motor (namely: rotational flux, saturation, high frequency…). Indeed, the mechanical and thermal stresses during the manufacturing steps can deteriorate the magnetic properties of the material and significantly increase the iron losses. These aspects are difficult to accurately evaluate by analytical models or standard measurements (Epstein frame…) and require experimental assessment to precisely calculate the motor efficiency.First of all, we started by developing a test bench equipped with drive motor: PMSM 8000 RPM ; 42 kW. For accurate assessment, the losses in this machine are separated on the test bench, for example, the mechanical losses (bearings loss & windage loss) have been measured at different speed with a non-magnetic rotor. Rotor magnets eddy-current losses cannot be isolated from iron losses, for this reason they have been calculated using a 3D finite element model. To limit rotor loss we then used a non-conductive retaining sleeve (heat shrink sleeve). In the winding, we used bar-wound conductors, which is an original winding technology developed in our laboratory, and whose advantage among others is the unusual copper fill factor that reaches almost 90%.Subsequently, we explored the high frequency machines (>1 kHz) in order to increase the power-to-weight ratio (cross the threshold of 2.5 kW/kg). We proposed, the following to the analytical and finite element study, a first conventional prototype with a power-to-weight ratio equal to 4.5 kW/kg with: FeCo stator (Vacodur49 0.2 mm), FeSi rotor and NdFeB magnets (N35EH), operated at 1666 Hz, 5000 RPM and 94% efficiency at full load. A second motor had been also proposed with both rotor and winding in aluminum, in this case the power-to-weight ratio reaches around 6 kW with, however, less efficiency (93%).Finally, this HF motor was tested, at no load, on the aforementioned test bench. The experiments were carried out on a multitude of FeCo and FeSi stator core samples coming from different manufacturing processes (insulation: bonding varnish and C-5 varnish; cutting: laser and EDM “Electrical Discharge Machining”; thermal treatment) in real operating conditions of a high frequency PM machine in order to experimentally obtain the famous “additional coefficient” of iron losses (Kadd).

<p>In the process of designing an electric power supply system for an aircraft, parameters like low weight and low losses are important. Reliability, robustness and low cost are other important factors. In the Saab Gripen aircraft, the design of the primary power supply of the electric flight control system was updated by exchanging a switching transistor regulator to a magnetic amplifier (magamp). By introducing a magamp design, weight was saved and a more reliable power supply system at a lower cost was achieved.</p><p> In this particular case, with the power supply of the electric flight control system in the Saab Gripen fighter, advantage could be taken of a specific permanent magnet generator (PM-generator). The frequency of the generator offered the perfect conditions for a magamp controller. A key parameter in designing magnetic amplifiers (magamps) is low losses. New amorphous alloys offer new possibilities of the technique in designing magnetic amplifiers, because of their extremely low losses.</p><p> The core losses are evaluated by studying the equations and diagrams specifying the power losses. The core losses are evaluated and compared with the copper losses in the process of optimizing low weight and low losses. For this an engineering tool is developed and demonstrated.</p><p> Evaluations of the hysteresis characteristics for the magnetic alloys, as well as modeling and simulation of the core losses, are presented in this work. The modeling of the core losses includes hysteresis losses, eddy current losses and excess losses as well as copper losses. The losses are studied dynamically during realistic operational conditions. The model can be used for any generic analysis of hysteresis in magnetic circuits. Applications of magnetic amplifiers in aircrafts have been demonstrated to be a feasible alternative</p>