Commande sans capteur de position des machines synchrones, application aux groupes motopropulseurs électrique

Permanent magnet synchronous machines are frequently used in transport electrification applications because of their high efficiency. The control of these machines requires knowing with precision the speed and the position of the rotor. Position sensors, habitually used, are efficient but present some inconvenient. They increase the global cost of the system, its weight and its volume. Sensorless control of electrical machines is currently a strong trend. It is primarily aimed to reduce the cost associated with control means while offering high performance and dynamic control. It is secondly targeted to insure operational continuity in case of failure in the mechanical sensor. In this context, the proposed PhD thesis is interested in the sensorless control of synchronous machines for electric traction applications. This type of application requires precise knowledge of the rotational speed and the rotor electrical position all over the entire operating range. This last one start from zero and attend the maximum speed of the machine. The estimation method should therefore be able to cover the ranges of "machine stopped", "very low speeds" and "medium-high speeds". The objective of this PhD thesis is to develop estimation methods that can be used in an electric powertrain with a focus on the very low speed and stand still areas. The results expected at the end of this thesis concern the following problematics. The first is to propose a method capable of maintaining a reference position under the action of the load torque at standstill position. The second is to be able to cover the area at very low speeds. The third is to propose an algorithm for the medium-high speed zone with a switching process between the two algorithms. Finally, the developed methods must respect a certain number of criteria such as reliability, dynamism and robustness.

Keywords : Commande sans capteur de position, machines synchrones à aimants permanents, traitement de signal, injections hautes fréquences, position à l’arrêt, très faibles vitesses, estimation de la position, saillance de la machine