Universal current vector controller for vector-controlled induction motors based on control of motional electromotive force

A universal current vector controller for vector-controlled induction motor (IM) drives, based on control of motional electromotive force (MEMF), is presented. It is demonstrated that the rotor field orientation decouples not only flux and torque but also transformer electromotive force (TEMF) and MEMF in rotor. The control of torque and speed in variable-frequency induction motor drives can be achieved by control of rotor MEMF. The proposed controller can achieve not only constant torque control with constant field but also constant power control with weakening field. The various vector controllers, including rotor flux oriented, airgap flux oriented, stator flux oriented and even arbitrary flux oriented, can be realized by simple changing few parameters. The results of simulation show that the proposed control scheme has good dynamic performance and an effective new way for the high performance speed control of induction motors is provided