Torque Ripple Minimization Strategy for Direct Torque Control of Induction Motor Using Fuzzy Scheme

The direct torque control (DTC) speed control scheme of an induction motor surpasses the vector control in the sense that it controls the torque directly and does not use transformations and current modulator. In the traditional direct torque control (DTC) of induction motor, the low order harmonic component of stator current is very large when the motor is running at low speed. It leads to high torque ripple of motor in low speed. To solve this problem, a new control method has been proposed in this paper. To improve the torque response and reduce the torque ripple, fuzzy logic concept has been introduced into the flux model. The simulation results depict that the proposed method not only improve the speed of torque response, but the problem of torque ripple can be effectively solved. In the whole speed range, the performance of dynamic and static is better than that of the conventional DTC.