A family of switching control strategies for the reduction of torque ripple on the direct torque and flux control for induction motors

In this paper we are interested in the design of switching control strategies which, as pursued in classical direct torque control (DTC), are aimed to directly regulate two outputs: torque and flux amplitude. A criterion in terms of the error and/or the prediction in one-step-ahead on these outputs is proposed to design the switching sequence. As a result, a control vector, i.e., the switch position, is directly selected without the requirement of an auxiliary space vector or other modulation technique. We consider two types of criterion: quadratic and absolute value. Finally, experimental results following these two approaches are presented and compared with respect to the classical DTC.