An observer for speed sensorless induction motor drive

An observer for a speed sensorless induction motor drive is proposed in the paper. It is easy to implement on a microprocessor with particular reference to high performance drives requiring the vectorial control technique which needs a flux observer. The proposed speed observer is based on an adequate arrangement of the error system equations, written in complex form in order to describe a full order flux observer. The results obtained by a numerical simulation show a very fast drive response, high accuracy of the velocity, flux and current estimation and a good robustness to the rotor resistance variations