CONDITION DIAGNOSIS METHOD FOR ASYNCHRONOUS MOTOR Russian patent published in 2013 - IPC G01R31/00 

FIELD: electricity.

SUBSTANCE: condition diagnosis method for asynchronous motor includes preliminary recording of integral estimate threshold value for asynchronous motor in fault-free condition. For this purpose using instantaneous values of phase stator currents for asynchronous motor in stable speed operation the resultant magnitude of current value is determined within the preset time period and intervals. It is decomposed into high- and low-frequency wavelet coefficients. Using high-frequency wavelet coefficients integral estimate is determined and permitted range of operation is formed on its basis as a threshold value. Thereafter instantaneous values of phase stator currents for asynchronous motor in stable speed operation are registered and the resultant current module is determined. It is decomposed into high- and low-frequency wavelet coefficients. Integral estimate is determined using high-frequency wavelet coefficients. Condition of asynchronous motor is estimated against deviation of the integral estimate from the permitted range of its operation. When the obtained integral estimate is not included into the permitted range of threshold value then conclusion is drawn about failure of asynchronous motor.

EFFECT: simplifying diagnosis method for electrical machines.

10 dwg