Torque ripple minimization in direct torque control of induction machines

A duty ratio control scheme for inverter-fed induction machines using the direct torque control (DTC) method is presented. An improved steady state torque response was achieved using the duty ratio control and had shown less torque ripple compared to the conventional DTC. Fuzzy logic control has been used to implement the duty ratio during each switching cycle using the torque and flux errors as inputs. Simulation results using SIMULINK gave results that justify the claims.