An MRAS Observer for Sensorless DFIM Drives With Direct Estimation of the Torque and Flux Rotor Current Components

This paper proposes a model reference adjustable system observer for the sensorless control of doubly fed induction machines. The formulation is based on the direct calculation of the torque and flux rotor current components in the stator-flux-oriented coordinates by using the stator currents and voltages and the norm of the rotor current space vector. The tuning of the observer is discussed, and a theoretical sensitivity and stability analysis is performed in order to investigate the behavior of the observer under mismatched parameters. The paper is completed by the experimental validation of the observer performances.