Direct torque control for induction motors based on discrete space vector modulation

The basic concept of direct torque control of induction machines is investigated in order to emphasize the effects produced by a given voltage vector on stator flux and torque variations. The low number of voltage vectors which can be applied to the machine using the basic DTC scheme may cause undesired torque and current ripple. An improvement DTC schemes proposed in the research literature is presented and compared with the classical. In this way a sort the improved scheme is called Discrete Space Vector Modulation (DSVM_DTC), and address the problem with torque ripple in the basic DTC system is introduced. Numerical simulations tests have been carried out to validate the proposed method.