US 12,405,307 B2
Abnormality detector apparatus and method for detecting abnormal state of rotary machine such as motor
Takahiro Sato, Kyoto (JP); Keisuke Yano, Kyoto (JP); and Takahiro Nakamura, Kyoto (JP)
Assigned to OMRON CORPORATION, Kyoto (JP)
Appl. No. 18/279,274
Filed by OMRON Corporation, Kyoto (JP)
PCT Filed Feb. 16, 2022, PCT No. PCT/JP2022/006151
§ 371(c)(1), (2) Date Aug. 29, 2023,
PCT Pub. No. WO2022/190795, PCT Pub. Date Sep. 15, 2022.
Claims priority of application No. 2021-036620 (JP), filed on Mar. 8, 2021.
Prior Publication US 2024/0151772 A1, May 9, 2024
Int. Cl. G01R 31/34 (2020.01); G01R 23/16 (2006.01); H02P 29/024 (2016.01)
CPC G01R 31/343 (2013.01) [G01R 23/16 (2013.01); H02P 29/024 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An abnormality detector apparatus that detects an abnormal state of a motor based on a current or a voltage supplied from a power supply to the motor, the abnormality detector apparatus comprising a signal processor unit configured to:
perform frequency analysis on data of the current or the voltage in different first and second time intervals to retrieve a first drive frequency corresponding to a maximum peak value of a spectrum in the first time interval and a second drive frequency corresponding to a maximum peak value of a spectrum in the second time interval;
adjust, based on a first spectrum having the first drive frequency and a second spectrum having the second drive frequency, a frequency axis of one spectrum such that the maximum peak values of the respective spectra coincide with each other, and then calculate an averaged spectrum relating to an adjusted spectrum and an unadjusted spectrum; and
retrieve an abnormal peak value equal to or more than a predetermined threshold value at a frequency different from the drive frequency having the maximum peak value based on the averaged spectrum, and then determine an abnormal state of the motor depending on presence or absence of the abnormal peak value.