US 12,032,025 B2
Permanent magnet synchronous motor diagnostic device and inverter comprising the same
Kenta Yuasa, Tokyo (JP); Kazunori Sakanobe, Tokyo (JP); Mamoru Kamikura, Tokyo (JP); and Toshiyuki Kuriyama, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/781,367
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Feb. 17, 2020, PCT No. PCT/JP2020/006102
§ 371(c)(1), (2) Date May 31, 2022,
PCT Pub. No. WO2021/166042, PCT Pub. Date Aug. 26, 2021.
Prior Publication US 2023/0003798 A1, Jan. 5, 2023
Int. Cl. G01R 31/34 (2020.01); G01R 19/00 (2006.01); H02P 25/022 (2016.01); H02P 27/06 (2006.01)
CPC G01R 31/34 (2013.01) [G01R 19/0092 (2013.01); H02P 25/022 (2013.01); H02P 27/06 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A permanent magnet synchronous motor diagnostic device, comprising:
a negative-sequence current calculator that calculates a negative-sequence current, based on magnitudes of a plurality of phase currents flowing through a permanent magnet synchronous motor that rotates a load;
a deterioration diagnoser that diagnoses, based on the negative-sequence current, deterioration of a plain bearing supporting a main shaft coupled to the permanent magnet synchronous motor; and
a phase generator that detects a frequency of the plurality of phase currents and generates, using the frequency, a counter-rotating voltage phase, which rotates in a direction oppose a phase rotation direction of the plurality of phase alternating currents,
wherein the negative-sequence current calculator calculates the negative-sequence current, based on the counter-rotating voltage phase and the plurality of phase currents.