Fuzzy based direct torque control of PMSM drive using an Extended Kalman Filter

There are big ripples on current and flux linkage and electromagnet torque under traditional direct torque control (DTC) on motor drive system. To solve these problems, fuzzy controller is designed to instead traditional hysteretic comparator, and zero voltage vectors are used to further reduce ripples. Rotor speed is estimated online by extended Kalman filter (EKF) algorithm. Speed sensorless DTC permanent magnet synchronous motor (PMSM) drive is realized. Rapid torque response and strong robustness of DTC are maintained, and the ripples on flux linkage and torque are greatly reduced. Meanwhile, system is robust to motor parameters and load disturbance. The system dynamic and static performances are dramatically improved. The simulation results have verified the feasibility and effectiveness of this method.