METHOD FOR DETERMINING SLIDING OF ROTOR OF ASYNCHRONOUS ELECTRIC MOTOR AS TO STATOR CURRENT Russian patent published in 2015 - IPC G01R31/34 

FIELD: engines and pumps.

SUBSTANCE: in a method for determining sliding of a rotor of an asynchronous electric motor, which involves an assessment value of rotor sliding, digital recording of an instantaneous amplitude value of consumed current in time on one of the cable phases feeding the asynchronous motor, by means of quick Fourier conversion there obtained is an amplitude spectrum of the recorded signal; maximum of the amplitude spectrum and its corresponding frequency that is close as to the value to mains frequency is determined; accurate value of mains frequency is determined by means of a method for autocorrelation of signal recording time by its subsequent reduction; as per the obtained value of mains frequency and the number of pairs of poles of the electric motor there calculated are boundaries of one frequency range for motors with one pair of poles, or two ranges for motors with the number of pairs of poles, which is bigger than one on the amplitude spectrum; maximum of amplitude spectra and their corresponding frequencies, which are close as to the value to harmonic frequencies from eccentricity of rotor of the first order, is determined in each of the obtained ranges; accurate values of harmonic frequencies from eccentricity of rotor of the first order are determined by means of the autocorrelation method of signal recording time by its subsequent reduction, as per which there obtained for motors with one pair of poles is one sliding value that is a final result for these motors, and for motors with two and more pairs of poles - two rotor sliding values; sliding of rotor of such asynchronous electric motor is calculated as per an arithmetical mean of these values.

EFFECT: improving accurate determination of a sliding value.

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