The harmonic saliency signals created by rotor slot
effects are found in the stator currents of most induction
motors, and their frequencies are inherently correlated with
the speed. In general, the relationships between speed and the
signals are determined by rotor slot number, pole pairs and the
way to obtain these signals. In this paper, a speed estimation
scheme based on dominant rotor slot harmonic is presented.
The separation and refinement of the signal are designed
according to its characteristics. Then, the frequency of the
signal is obtained by simplest way. Finally, speed is calculated
based on the frequency information. The robustness and
effectiveness of the proposed scheme have been validated by
simulation and experimental results.