Performance improvement of direct torque control for doubly fed induction generator with 12 sector methodology

Direct Torque Control (DTC) is a control technique which is commonly used for speed control of induction machine drives. Compared with the available control techniques, DTC is characterized by controlling the torque and the rotor flux directly without the use of current or voltage regulators, coordinate transformation, and PWM control technique. Though its simplicity in design, it achieves good control of the torque. Nevertheless, the hysteresis band in DTC produces ripples in flux and torque. In this paper, a comparison of conventional DTC scheme and the twelve sector DTC methodology for a doubly-fed induction machine (DFIG) is implemented according to the output torque ripple. Simulation results show the performance improvement of the twelve sector methodology over the conventional DTC technique. The simulations are performed in MATLAB / SIMULINK environment.