Flux position estimation in cage induction machines using synchronous HF injection and Kalman filtering

This paper proposes a new approach to the tracking of the flux position saliency of an induction machine by means of high-frequency (HF) signal injection in the synchronous rotating frame. The paper will show that existing synchronous pulsating injection methods perform poorly in the presence of secondary saliencies. A modified scheme is proposed in which a rotating HF field is established in the dq rotating reference frame. The scheme enhances the performance of harmonic elimination methods to reduce the effects of secondary saliencies. A new harmonic elimination method based on the Kalman filter is proposed in the paper. Experimental results are given showing the effectiveness of the harmonic elimination and the resulting tracking of the saturation saliency.