Adaptive sliding observers for direct field-oriented control of induction motor

Design methods are presented for adaptive sliding observers for induction motor control, which include both the rotor speed and the rotor resistance identification together with the rotor flux estimation. The proposed adaptive observers have the advantage of global stability over the conventional identification algorithms, which are developed on restrictive assumptions. The primary reason for the simplicity of the analysis is the separation of the identifier from the controller, which is not realizable in conventional algorithms