This paper describes a new speed estimator having a mutual
inductance tuning algorithm when the induction motor is
operated under the saturation condition. The proposed scheme
is based on the full-order rotor flux observer with a new error
correction term, which includes the error between the flux derived
from the stator voltage equation and the flux estimated
from the rotor flux observer. Proposed method can estimate the
rotor speed without the influence of the inductance variations
resulting from the flux saturation. It is verified from the experimental
results that the proposed scheme can increase the motor
dynamics even under the saturation conditions.