Using of EKF for speed sensorless SVM-DTC in induction motor at low speed

Extended Kalman Filter (EKF) is a special type of observer, which filters out measurement and system noises while at the same time estimate the state variables. With the inevitable increased in the temperature due to the continuous operation, the performance of the induction motor drive system, especially at low speed, is more affected by the stator resistance than the rotor resistance. So, at low speed operation, speed estimation using EKF based on rotor flux is more accurate than the stator flux based EKF. In this work, a speed estimation using an EKF based on rotor flux for Space Vector Modulation-Direct Torque Control (SVM-DTC) of a three-phase induction motor at low speed is presented. Simulation results showed excellence performance and the effectiveness of the presented system.