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, φ_sa and φ_sß, the rotor angular velocity, ω_m, the rotor resistance, R´_r, the stator resistance, R_s, the load torque involving the viscous friction term, t_L, and the reciprocal total inertia of the IM and load, γ_τ =̂ 1/j_T, as well as stator stationary axis components of stator currents, i_sα and i_sß, 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.