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. 02, 2003
Filed:
Aug. 30, 2001
Seiji Ishida, Hitachi, JP;
Keijiro Sakai, Kuji, JP;
Toshiaki Okuyama, Naka, JP;
Hiroshi Fujii, Chiba, JP;
Hiroyuki Tomita, Funabashi, JP;
Tatsuo Ando, Shimizu, JP;
Yuhachi Takakura, Oyama, JP;
Hideo Kimura, Takahagi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In detecting an output current of a power converter based on a DC current Idc of the power converter, the pulse width of the DC current Idc becomes narrower when the pulse width of a line voltage is narrower, and its detection becomes difficult. A voltage command correction unit according to the present invention corrects voltage commands such that pulse width of a line voltage becomes zero when the pulse width of the line voltage is less than the minimum pulse width, not to output a line pulse, and an error generated by the correction is integrated. This integrated error is added to the line voltage in the next time, and the integrated pulse width of the line voltage is outputted when the pulse width becomes larger than or equal to the minimum pulse width.