DTC-SVPWM method for PMSM control using a fuzzy stator resistance estimator

Direct Torque Control (DTC) is a well known control method, which is used to control the flux and torque of a motor. This method uses a flux and torque estimator and two hysteresis controllers. The main drawbacks of DTC are high torque and flux ripple. To overcome these problems, a DTC-SVPWM method is used which decreases the torque and flux ripple considerably. The stator resistance is used in the flux and torque estimator for both DTC and DTC-SVPWM. So the stator resistance deviation from its set value, might affect DTC-SVPWM performance. In this paper a proposed fuzzy stator resistance estimator is used for DTC-SVPWM controller, which improved controller performance.