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:
Dec. 30, 2003
Filed:
Dec. 07, 2001
Applicant:
Inventors:
Kazuaki Tobari, Hitachiota, JP;
Toshiaki Okuyama, Tokai-mura, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P 5/28 ;
U.S. Cl.
CPC ...
H02P 5/28 ;
Abstract
If a speed instruction value is less than a predetermined value, the output current of a power-conversion unit is controlled to be larger than a current value in an ordinary no-load operation, or a frequency instruction value is calculated based on a speed instruction value in place of an estimated speed.