SPECTRAL METHOD FOR ESTIMATING THE FREQUENCY OF ASYNCHRONOUS MOTORS SLOT HARMONICS
The article presents a theoretical analysis of the magnetic field distribution in the air gap of an induction motor, which takes into account the presence of slots on the rotor and on the stator. An analysis of a mathematical model that describes the location of slot harmonics in the frequency of the stator current spectrum-axis shows the formula for calculating the rotor speed frequency of slot harmonics. This model can be used in the development of the system sensorless determination of rotational speed of the induction motor with squirrel-cage rotor. These systems enable remote monitoring of the frequency of associated mechanisms without speed sensors, since their installation, in some cases, impossible or undesirable.