Adaptive Control of an Induction Motor with Magnetic Saturation Under Time-Varying Load Torque Uncertainty

A new global adaptive controller is designed for speed control induction motor with magnetic saturation, based on measurements of speed and stator currents. The designed partial state feedback controller is singularity free, and guarantees asymptotic tracking of smooth reference trajectories for the speed of the motor under time varying load torque. The new control algorithm generates estimates for unknown time varying load torque and rotor flux which asymptotically tracks and converges to their true values. The rotor flux modulus asymptotically tracks a desired reference signal which allows the motor to operate within its specifications. As in the field-oriented control scheme, the control algorithm generates references for the magnetizing flux component and for the speed component of the stator current. The control strategy yields decoupled rotor speed and rotor flux amplitude tracking control goals.