An optimal control strategy of direct torque control for induction motor

In traditional control method of direct torque control (DTC), the selection of voltage space vector is based on the sector of flux, not on the precise position of flux, so the voltage space vector is not the optimal one. In this paper, a new optimal control strategy of DTC for induction motor is presented. In this method, a flux error vector is defined, and the optimal voltage space vector is selected with no deadbeat. The control method of DTC is simplified, the constant switch frequency of power device is increased, and the performance of DTC in low speed region is improved. The results of simulation indicate the validity of this method.