METHOD FOR DIAGNOSING THE TECHNICAL CONDITION OF ASYNCHRONOUS ELECTRIC MOTORS AND A DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2023 - IPC G01R31/34 H02K17/02 

FIELD: diagnosing technical condition of asynchronous motors.

SUBSTANCE: testing is carried out through the phases of the stator winding C, A, B, while the phases of the rotor winding are short-circuited. The external and internal testing cycles consist of three and one experiment, respectively, during which 9 elements of the current Green's matrix are determined. In the first experiment of the outer cycle, phase C is opened, and a pulsed voltage in the form of a Dirac delta function is applied to two phases A, B that are serially opposite-connected. The current amplitudes of phases C, A, B are fixed and stored as three numerical elements of the first column of the current Green's matrix. In this case, for phases A and B, the amplitudes of the currents coincide, and for phase C, the zero value of the current amplitude is fixed and maintained. In the next two experiments of the outer loop, phases A and B remain open, a pulsed voltage in the form of a Dirac delta function is applied to the consecutively connected phases B, C and C, A. The numerical elements of the second and third columns of the current Green matrix are fixed and stored. Based on the results of comparing the elements of the current Green's matrix with the corresponding elements of the reference Green's matrix, the elements of the normalized matrix of current deviations are calculated. From among its elements, the maximum current deviation is distinguished and the current values of the rate of operational changes, the probability of maintaining operability, and the residual resource are calculated. The device contains a source of pulsed voltage, configured to be connected in parallel to the phases of the diagnosed electric motor when performing experiments of the external cycle, and a measuring unit connected in series with it, designed to record, visualize and process diagnostic information, and configured to be connected in series to the phases of the diagnosed electric motor when performing experiments of the inner cycle. The measuring unit contains a virtual oscilloscope based on a personal computer and an oscilloscope attachment, and a current shunt made in the form of a current signal sensor. The pulse voltage source is configured to generate pulses in the form of a Dirac delta function and connect to the serially opposite-connected phases A and B, B and C, C and A of the electric motor when performing external cycle experiments. The final diagnostic information is a set of four numerical values of indicators of the current technical condition of the electric motor.

EFFECT: expanding functionality and scope by increasing diagnosed objects, including electric motors with a squirrel-cage rotor, obtaining operational changes, degree of their criticality and residual resource while reducing the methodological and informational bulkiness of the process and diagnostic results.

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