Stability analysis of sensorless IM based on adaptive feedback linearization control with unknown stator and rotor resistances

In this paper, stability analysis of a sensorless induction motor drive based on adaptive feedback linearization control is presented, while mismatch in both rotor and stator resistances are taken into account. A Lyapunov function, based on observer and controller dynamics, and using airgap flux model, is proposed. Theoretical analysis along with experimental results show that stator and rotor resistances converge to actual values, if the appropriate adaptation laws are designed, and persistent excitation (PE) condition is satisfied. Furthermore, flux, torque, and rotor speed are estimated and controlled successfully.