Rotor Speed Estimation of Induction Motor Utilizing Rotor Slot Harmonics Of Stator Current

The main methods of determining the rotor speed for induction motor using the effect of slot harmonics are considered. Most of these methods are based on the identification of higher harmonics in the composition of the supply voltages and currents, caused by the difference in the values of the magnetic induction in the air gap opposite the slots and teeth of the rotor. The amplitude-frequency spectrum of the current was investigated in the presence of a high-frequency component of the stator voltage. Programs have been developed for observing the rotation frequency using the fast Fourier transform of the stator current.