Robust speed-controlled induction-motor drive using EKF and RLS estimators

An induction-motor (IM) speed drive, with the application of an extended Kalman filter (EKF) and a proposed recursive least-square (RLS) estimator, is introduced. The rotor resistance of the IM is identified by the EKF, and the rotor inertia constant, the damping constant and the disturbed load torque of the IM are estimated by the proposed RLS estimator, which is composed of an RLS estimator and a torque observer. The integral proportional (IF) speed controller is on-line, designed according to the estimated rotor parameters. Then the observed disturbance torque is fed forward to increase the robustness of the induction-motor speed drive.