Speed-sensorless direct torque control system using Bi-input extended Kalman filter for induction motors

In this study, a speed-sensorless direct torque control (DTC) system using bi input-extended Kalman filter (BI-EKF) is designed to perform the high performance velocity control of induction motors (IMs). The BI-EKF algorithm estimates stator stationary axis components of the stator fluxes, φsa and φsß, the rotor angular velocity, ωm, the rotor resistance, R'r, the stator resistance, Rs, the load torque involving the viscous friction term, tL, and the reciprocal total inertia of the IM and load, γτ ≜ 1/jT, as well as stator stationary axis components of stator currents, isα and isß, which are also measured as output. The simulation results prove very satisfying performances of the BI-EKF algorithm and therefore the speed-sensorless DTC system.