Abstract
The aeronautics transport is continuously growing. Forecast shows that the number of flights will have doubled by 2037 reaching 8.2 billion of air travelers, with China and India as the main and fastest-growing markets. Urban mobility will be revolutionized and transformed by new aircraft concepts for commuting and delivering services replacing cars. Severe restrictions are defined in order to decrease the impact on environment, pushing aeronautics industries to reach the targets in terms of noise and gas emissions by proposing new hybrid/full electric aircraft concepts. Enhancing the power converters efficiency and compactness thus represents a strategic research framework in this domain. Given this context, the main goal of this PhD consists in contributing to the minimization of the volume and mass of electrical machine active parts while preserving its efficiency. In literature, direct driven configurations are usually preferred due to their higher performance and reliability. The increase in compactness, involving necessarily an increase in the number of poles, is accompanied by a raise in losses per unit of exchange area generated by a raise in frequency. Therefore, in this thesis we firstly present a thermomechanical model coupled to the electromagnetics one in order to push the frequency limit as far as possible and to analyze more severe constraints of ambient temperatures. The aim of this analysis is also to confirm the performance obtained when using sector distributed bar-wound windings, previously studied by our IES laboratory, and to investigate the thermal behavior of this solution compared to a more conventional one. In fact, taking into account the high level of losses due to the high frequency, the risk of demagnetization or drop in torque is high. Solutions are therefore provided, secondly, in order to minimize the current losses induced in the winding and in the magnets. To this end, adequate multiphysical modeling, by Node Networks, by Finite Elements, and by Computational Fluid Dynamics was necessary in order to assess these risks and to adequately sizing an optimal cooling system. These models are finally implemented in order to carry out the sizing, design and assembly of the converter on the basis of a set of specification transmitted by SAFRAN. Bench analyzes will then conclude and validate this work. All of these models have thus enabled the optimization of the performance of the electromechanical converter.