Identification of time-varying rotor and stator resistances of induction motors

This paper deals with the identification of the stator and rotor resistances. The originality of this work is that it considers both rotor and stator resistances as time-varying parameters. Two schemes for the rotor resistance identification and one scheme for both stator and rotor resistances identification are outlined. The first and the third schemes use the measured stator current, voltage command and rotor speed while the second scheme uses only stator current and voltage commands. All schemes are based on the sliding mode observer and the convergence of the estimates to their true values does not required the persistence of excitation conditions to be satisfied by the input signal.