Self-sensing control of induction machines using an additional short-circuited rotor coil

This paper presents a self-sensing control for an induction machine over a wide speed range, introducing a method which combines an EMF-based and a saliency-based approach. The major advantage of the proposed method is a simple-to-implement estimator for the entire speed range with low computational effort and an arbitrary high-frequency injection. Furthermore, a novel rotor design of an induction machine is suggested using an additional short-circuit coil. The integration of such a coil generates resistive and inductive saliencies which are mainly effective for high frequencies. Thus, the self-sensing ability for the low speed range can be significantly improved.