Sensorless direct torque and flux control of induction motor based on MRAS and Luenberger observer

In this paper, a Luenberger observer (LO) with a model reference adaptive system (MRAS) are associated for a sensorless direct torque Control (DTC) of an induction motor (IM). It is shown by an extensive study that this adaptive observer is completely satisfactory at low and nominal speed ranges and it is robust to load torque variations. The proposed control scheme achieves a good performance with computational complexity reduction obtained using analytical relation to determine the LO gain matrix. The effectiveness of the proposed scheme is checked via extensive simulation work. Simulation results prove that the proposed overall scheme provides both the stator flux and rotor speed estimation with good transient and steady state performances.