The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 2021
Filed:
Oct. 09, 2019
Applicant:
Hitachi, Ltd., Tokyo, JP;
Inventors:
Assignee:
HITACHI, LTD., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R 31/00 (2006.01); H02P 29/50 (2016.01); G01M 1/22 (2006.01); G01R 19/25 (2006.01); G01R 23/167 (2006.01); G01R 19/00 (2006.01); H02P 29/024 (2016.01);
U.S. Cl.
CPC ...
H02P 29/50 (2016.02); G01M 1/22 (2013.01); G01R 19/0007 (2013.01); G01R 19/2513 (2013.01); G01R 23/167 (2013.01); G01R 31/005 (2013.01); H02P 29/024 (2013.01);
Abstract
A current detector and a detection unit are provided. The current detector is connected to at least one of drive current lines of a rotary machine. The detection unit performs an orthogonal detection on a main frequency detected by the current detector, and extracts a magnitude of a sideband wave. Then, a state of the rotary machine is diagnosed from the magnitude of the extracted sideband wave.