Torque control of induction machine by vector approximation with parameter adaptation based on MRAS

This paper shows a torque control method for a current-controlled induction machine. As the control strategy, vector approximation with parameter adaptation based on model reference adaptive system (MRAS) is proposed. The main purpose of the vector approximation method is not only to decrease torque ripple but also to control instantaneous torque, which is different from that of the general PWM method. The magnitude of torque is adjusted to the desirable value by parameter adaptation, and parameter mismatching due to the rotor resistance variation is compensated. The proposed system also considers the inductance variation. The capability of precise torque control with this system is verified by simulation and experiments