Fuzzy DTC for induction motor with optimized command stator flux

In order to reduce torque ripple of direct torque control (DTC) scheme, a novel stator flux reference optimize strategy is introduced first in this paper. Then, a fuzzy logic controller is designed to select synthesized voltage vectors. Three inputs of the fuzzy controller are the error of electromagnetic torque and the error of square stator flux linkage between the reference value and actual value and torque angle. The output of the fuzzy controller is corresponding voltage vector. The proposed control scheme is verified by simulations. Simulation results show that a reduction of torque ripples is achieved in a whole speed range.