Sensorless MRAS-based induction motor control with parallel speed and stator resistance estimation

Abstract

This paper proposes a novel MRAS-based speed controller for the induction motor drive without shaft sensor, with the integral adaptation mechanism for on-line tuning of the stator resistance (R s ). For an accurate estimate of the shaft speed (ω) even at near zero speeds, proposed R s estimator running parallel in order to compensate for the R s thermal variation. In an intent to accurately estimate the ω at low speeds, without deterioration the drive performance, parallel with the ω estimation the R s is also estimated to compensate R s thermal variation. The reference and adjustable models of MRAS-based ω estimator change their roles in the R s estimator context. The dynamics of the ω derivation and the R s estimation are investigated for a wide range of operating conditions and straightforward design procedure is proposed, derived from the hyperstability theory. Extensive computer simulations prove the effectiveness of the proposed solution.