Induction Motors Speed Estimation by Rotor Slot Harmonics Frequency Using Zoom Improved Chirp-Z Transform Algorithm

This paper analyzes the digital signal processing techniques and estimates induction motor (IM) rotational speed operating in stationary or non-stationary conditions. Rotor slot harmonics present stator current waveform are used to estimate with a given identified rotor numbers. paper’s contribution is following: First, zoom improved short-time Chirp-Z transform find supply frequency harmonic improve estimation accuracy without increasing computing complexity. Second, technique described that can be determine whether not generate principal (PSH). Finally, an algorithm designed figure out perfect window length motors’ speed. proposed was investigated when fed by inverter-fed driving variable load Experimental test results on 5.5 kW 22 motors have confirmed correctness of this method.