METHOD OF DIAGNOSING TECHNICAL STATE OF ELECTRIC MOTORS BY ANALYSIS OF CURRENT SIGNALS Russian patent published in 2024 - IPC G01R31/34 

FIELD: measuring.

SUBSTANCE: invention relates to the field of measuring equipment, namely to diagnosing the technical state of electric motors (hereinafter referred to as "electric motors"), and can be used to monitor the current technical state of electrical equipment of complex technical systems of enterprises with a continuous production cycle. Method for diagnosing the technical state of an electric motor by analysing current signals is characterized by that the reference signals of the current sensors installed on the phase conductors of a serviceable electric motor are determined, performing mathematical processing of received signals using a computer system, then determining the experimental signals of the current sensors installed on the phase conductors of the diagnosed electric motor, performing their mathematical processing and comparing the reference and experimental processing results; at that, for mathematical processing of reference signals of a serviceable electric motor, the values of the consumed currents of the serviceable electric motor are measured and recorded at different frequencies of its shaft rotations; frequency values of rotation of a shaft of a serviceable electric motor are fixed; from arrays of received signals of consumed currents by method of non-overlapping window calculating by means of computer system average value and root-mean-square deviation by size of window k; pairwise calculation of correlation coefficients between the calculated root-mean-square deviations of the current signals of the first, second and third phases by the size of the window k; fixing the reference values of the calculated correlation coefficients for the previously fixed rotation frequencies of the shaft of the serviceable electric motor; for mathematical processing of current signals of a diagnosed electric motor during operation, values of consumed currents of said electric motor are measured at previously fixed frequencies of rotation of a shaft of a serviceable electric motor; from the arrays of the received signals of the consumed currents of the diagnosed electric motor by the non-intersecting window method, the root-mean-square deviation by the size of the window k is calculated using a computer system; pairwise calculating the correlation coefficients between the calculated root-mean-square deviations of the current signals of the first, second and third phases of the diagnosed electric motor by the size of the window k; then comparing calculated values of correlation coefficients for serviceable electric motor with calculated values of correlation coefficients for diagnosed electric motor; if there is a difference between the correlation coefficients of the diagnosed and sound motor by more than 20 %, a conclusion is made on the presence of a defect in the motor being diagnosed.

EFFECT: improving reliability of diagnostics of technical condition of electric motors by analysis of current signals during operation.

1 cl, 4 dwg