Utilisation du contrôle directe du flux statorique et du filtre de Kalman en vue du contrôle direct du couple d'un moteur asynchrone

Abstract

In this memory, we present a detailed study of two significant structures of control which are the vectorial control, based on the orientation of the rotor flux and which was very largely widespread in the industrial sectors, and the direct torque control (DTC) which is presented as an alternative to the vectorial control. The direct torque control is undoubtedly a very promising solution to problems of robustness and dynamics met in vectorial control with directed rotor flux. Research in progress is directed towards the improvement of the performances of this technique whose principal problems are the evolution of the commutation frequency, the undulations on the torque, flux and the current. For that, our work is articulated around the following points:  improvement of the traditional DTC performances by the use of three approaches : the zonal shift, change of the truth table by the use of a modified table and a table with 12 sectors,  development of a direct torque control without sensor by the use of the extended Kalman filter at the rotational mechanical speed . Results of simulation show that this filter presents an interesting robustness to variations charge and noise. Remarkable improvements were observed.