Luenberger observer based sensorless Indirect FOC with stator resistance adaptation

In the last years, several Field Oriented Control (FOC) methods of induction motors without rational transducers have been proposed. The major drawback of most of these methods is there sensitivity to motor parameters variations especially the stator resistance that affects the drive performances at low speeds. Therefore, simultaneous estimation of rotor speed and stator resistance from measured stator terminal voltages and currents is proposed using Luenberger adaptive observer approach. The stability of this observer is proved by the Lyapunov´s theorem and the feasibility of the proposed method is verified by simulation under Matlab /Simulink.