US 12,216,166 B2
Diagnostic apparatus, diagnostic method, recording medium having recorded thereon diagnostic program, and power conversion apparatus including diagnostic apparatus
Hiroaki Ueta, Hino (JP); and Hiroyuki Kokubun, Hino (JP)
Assigned to FUJI ELECTRIC CO., LTD., Kanagawa (JP)
Filed by FUJI ELECTRIC CO., LTD., Kanagawa (JP)
Filed on Apr. 25, 2022, as Appl. No. 17/728,931.
Claims priority of application No. 2021-092549 (JP), filed on Jun. 1, 2021.
Prior Publication US 2022/0381829 A1, Dec. 1, 2022
Int. Cl. G01R 31/34 (2020.01); H02H 7/085 (2006.01); H02P 29/024 (2016.01); H02M 1/32 (2007.01)
CPC G01R 31/343 (2013.01) [H02H 7/085 (2013.01); H02P 29/024 (2013.01); H02M 1/32 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A diagnostic method comprising:
controlling a motor to rotate;
acquiring target data relating to a current value of electrical current between a power conversion apparatus and the motor;
detecting at least three latest peak values in a time series waveform of the target data;
using a frequency counting method to calculate an amplitude of each of the at least three latest peak values and a frequency of occurrence of the amplitude of each of the at least three latest peak values;
diagnosing an abnormality of the motor based on the calculated amplitude of the at least three latest peak values and the frequency of occurrence of the amplitude of the at least three latest peak values; and
stopping the rotation of the motor based on the diagnosed abnormality, wherein
the amplitude of each of the at least three latest peak values is an absolute value of a difference in amplitude between two adjacent ones of the at least three latest peak values, and
a weight of either 0.5 cycle or 1.0 cycle is assigned to each of the at least three latest peak values.