An Induction Motor Drive System Employing Salient Features of Vector and Direct Torque Controls

The control of high performance AC motor drives has reached a high level of maturity based on two competing methods i.e. vector control and direct torque control known since early seventies and mid eighties respectively. In this paper a new control system is proposed for three phase high performance induction motor drives based on a common basis provided for vector controlled and direct torque controlled induction motors. The control system enjoys partially the advantages of vector control and direct torque control and avoids some of the implementation difficulties of either of the two control methods. In particular, the proposed control system includes a current vector control in connection with a switching table. An extensive comparative performance evaluation of a motor under the proposed control system confirms its effectiveness and partial superiority over either vector control or direct torque control, despite its relative structural simplicity.