Development of partial model-based torque control of AC induction motors

A partial model-based torque control algorithm is developed for alternate c urrent (ac) induction motors. The motor is regarded as a torque source, and a desired torque signal is designed based on the desired position trajecto ry. A reference quadrature axis current input is further developed to cause the torque to track the designed torque signal, utilizing a torque feedfor ward plus a PI-type torque feedback control. The method utilizes partial kn owledge of the electromechanical dynamic model of the induction motor. Expe riments conducted on a commercial ac induction servo system demonstrate the validity of the proposed approach.