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.

Electro Hydrostatic Actuators (EHA) are emerging as a viable option for industrial machine builders as the design combines the best of both electro-mechanical and electro-hydraulic technologies. The EHA is a highly integrated, compact alternative to traditional hydraulic solutions. Automation engineers moving toward electro-mechanical actuation in pursuit of energy efficiency and environmental cleanliness, will find an EHA an attractive option for high force density actuators. This paper will address the factors to consider when assessing an industrial machine’s application suitability for this latest innovation in actuation. It describes principal base circuits, a concept for EHA building blocks and a realized pilot application as well as challenges on actuator and components level.

Electro Hydrostatic Actuators (EHA) are emerging as a viable option for industrial machine builders as the design combines the best of both electro-mechanical and electro-hydraulic technologies. The EHA is a highly integrated, compact alternative to traditional hydraulic solutions. Automation engineers moving toward electro-mechanical actuation in pursuit of energy efficiency and environmental cleanliness, will find an EHA an attractive option for high force density actuators. This paper will address the factors to consider when assessing an industrial machine’s application suitability for this latest innovation in actuation. It describes principal base circuits, a concept for EHA building blocks and a realized pilot application as well as challenges on actuator and components level.

<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>

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. 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. 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. 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 / QC 20101103