US 11,953,555 B2
Abnormality diagnosis device, abnormality diagnosis method, and abnormality diagnosis system
Makoto Kanemaru, Tokyo (JP); Takuya Ohkubo, Tokyo (JP); Sota Sano, Tokyo (JP); Akira Satake, Tokyo (JP); and Satoru Terashima, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 16/644,168
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Oct. 24, 2017, PCT No. PCT/JP2017/038379
§ 371(c)(1), (2) Date Mar. 4, 2020,
PCT Pub. No. WO2019/082277, PCT Pub. Date May 2, 2019.
Prior Publication US 2020/0217895 A1, Jul. 9, 2020
Int. Cl. G01R 31/34 (2020.01); H02H 7/08 (2006.01); H02P 29/024 (2016.01)
CPC G01R 31/343 (2013.01) [H02H 7/08 (2013.01); H02P 29/027 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An abnormality diagnosis device for diagnosing an abnormality in an electric motor, the abnormality diagnosis device comprising:
a data acquisition circuit to acquire a current waveform and a driving frequency of the electric motor driven by a power conversion device;
an operation pattern storage which stores a combination of an effective value of the current waveform and the driving frequency that are acquired at an identical time by the data acquisition circuit, the effective value of the current waveform being a square root of a value obtained by averaging a square of an instantaneous value of the current waveform over one cycle of the current waveform;
a data determination circuit to determine whether or not an effective value of the current waveform and the driving frequency as a diagnosis target that are acquired at an identical time by the data acquisition circuit match the combination of the effective value of the current waveform and the driving frequency stored in the operation pattern storage;
an analyzer circuit to perform frequency analysis for the current waveform determined to be matched by the data determination circuit, to extract sideband waves, and calculate a spectrum intensity of the sideband waves;
an abnormality diagnosis circuit to make a diagnosis that abnormality has occurred in the electric motor, when the spectrum intensity of the sideband waves is equal to or greater than a threshold;
a learning table configured to store a plurality of learning combinations, each of the plurality of learning combinations includes the effective value of the current waveform and the driving frequency that are acquired at the identical time, the identical time being different for each of the plurality of learning combinations;
the learning table is further configured to store for each of the plurality of learning combinations, a number of times an identical learning combination having a same effective value of the current waveform and a same driving frequency is acquired; and
the operation pattern storage stores one of the learning combinations as the combination of the effective value of the current waveform and the driving frequency that are acquired at the identical time only when the number of times of the learning combination is equal to or greater than a predetermined setting value.