Method for diagnosing bearing fault on basis of motor three-phase current signal, and device for performing method
A method for diagnosing a bearing fault on the basis of a current signal, and a device for performing the method, can include the steps, performed by a bearing failure diagnostic device, of: receiving a motor three-phase current signal; denoising the motor three-phase current signal; converting the denoised motor three-phase current signal to a single-phase current signal; determining a characteristic factor on the basis of the single-phase current signal; and determining, on the basis of the characteristic factor, whether a bearing fault exists.
1 . A method for diagnosing a defect in a bearing based on a current signal, the method comprising:
receiving, by a bearing defect diagnosis apparatus, a motor three-phase current signal;
performing, by the bearing defect diagnosis apparatus, denoising on the motor three-phase current signal;
transforming, by the bearing defect diagnosis apparatus, the denoised motor three-phase current signal into a single-phase current signal;
determining, by the bearing defect diagnosis apparatus, a feature based on the single-phase current signal; and
determining, by the bearing defect diagnosis apparatus, whether the bearing is defective based on the feature,
wherein the transforming of the denoised motor three-phase current signal into the single-phase current signal includes:
a first transformation step of transforming, by the bearing defect diagnosis apparatus, the denoised motor three-phase current signal into a two-phase current signal; and
a second transformation step of transforming, by the bearing defect diagnosis apparatus, the two-phase current signal into the single-phase current signal.
2 . The method of claim 1 , wherein the first transformation step is performed through transformation into a two-dimensional coordinate system having a d-axis coincident with a direction of magnetic flux generated by an a-phase of a spatial coordinate system of the motor three-phase current signal and a q-axis orthogonal thereto, and the second transformation step is performed through vector calculation.
3 . A bearing defect diagnosis apparatus configured to diagnose a defect in bearing based on a current signal, the bearing defect diagnosis apparatus comprising:
a current data receiver implemented to receive a motor three-phase current signal; and
a processor operably connected to the current data receiver,
wherein the processor is implemented to
perform denoising on the motor three-phase current signal,
transform the denoised motor three-phase current signal into a single-phase current signal,
determine a feature based on the single-phase current signal, and
determine whether the bearing is defective based on the feature,
wherein the processor performs a first transformation for transforming the denoised motor three-phase current signal into a two-phase current signal and a second transformation for transforming the two-phase current signal into the single-phase current signal.
4 . The bearing defect diagnosis apparatus of claim 3 , wherein the first transformation is performed through transformation into a two-dimensional coordinate system having a d-axis coincident with a direction of magnetic flux generated by an a-phase of a spatial coordinate system of the motor three-phase current signal and a q-axis orthogonal thereto, and the second transformation is performed through vector calculation.