Doctorant sous la direction de E. GODOY

Titre de la thèse: Robust and high performance sensorless control of high speed starter-generators with high starting torque, for the more electric aircrafts
Résumé de la thèse: The evolution to the “more electric aircraft” bring forward new requirements for the electric drive systems (motor drive and its associated electronics) in order to increase the available on-board power while minimizing the overall mass, volume and cost. Among the ongoing studies on motor drives, the aerospace industry and Thales Avionics Electrical Systems (Thales AES), in particular, are interested in the development of starter/generators with multi-level brushless synchronous machines. These drives are likely to provide the high torque required to start-up of the reactors to which they are associated. Depending on the purpose of each system, their proximity to the reactor is an extremely severe constraint requiring mechanical sensors to operate in a very high temperature atmosphere (330° C). These new electric drive systems require knowledge of the rotor position at all times in order to provide effective control laws. Also, the avionics applications require high reliability. Therefore, sensorless control lows of multi-level brushless synchronous machines is a subject that engages the attention of manufacturers. The work is focused on the study, design, simulation and experimental validation of sensorless control laws applied to a three-level brushless synchronous machine in starter mode in order to provide high torque at very low speed and standstill. The goal is to obtain sensorless control solutions that comply with the aeronautical requirements in terms of reliability and dependability, robustness and precision over the entire speed range and even standstill. Multiple algorithms can be proposed for different speed ranges. Following an extensive literature review in order to define correctly the state of the art and eventual difficulties to overcome, this thesis will lead to the synthesis of possible solutions applicable to a three level starter/generator proposed by Thales AES. Parametric robustness and the costs implied will refine the choice between the proposed low speed estimation techniques. Finally, part of the activity will be dedicated to adapting the selected algorithms to different machines (salient and non-salient poles, cooled with air or oil etc.).