Sensorless Feedback Linearization Direct Torque Control (FBL-DTC) for Induction Motor Drive with Five-Level Cascaded H-Bridge Inverter

This paper presents a sensorless feedback linearization direct torque control (FBL-DTC) for an induction motor drive with five-level cascaded H-bridge (CHB) inverter. The control of CHB multilevel inverter is realized by multicarrier based third harmonic injection PWM (THIPWM) technique. The alpha and beta components of reference voltage vector are obtained from the feedback linearization approach that achieves a decoupled torque and flux control. To estimate the rotor speed and the stator resistance simultaneously, an extended Kalman filter (EKF) based observer is developed. An adaptive scheme that uses the estimated states and parameters is established to increase the robustness of feedback linearization control against model and measurement uncertainties. The effectiveness of proposed drive system is tested under some challenging operating conditions and verified by the simulation results.