Dymko S. Field-Oriented Control of Induction Motors with Torque per Ampere Maximization

The further development has received the method of vector control algorithms of design for induction motor with torque per Ampere maximization in steady state. The torque/speed controller was designed using the output-feedback linearizing control with direct observer-based field orientation. The proposed controller guarantees asymptotic torque (speed) tracking and maximizes a torque per Ampere ratio in steady state. The saturation effect is taken into account in order to improve torque/speed control accuracy and remove the restrictions on the use the MTA criterion. Since maximization of torque per Ampere ratio is close to the optimization criterion of minimum active losses the increase of the motor efficiency at light loads is also achieved. Intensive experimental comparison study of the proposed controllers and standard indirect field oriented control with constant flux operation shows that significant stator current reduction is obtained for the same torque and speed transient performances.