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:
Jul. 14, 2009
Filed:
Mar. 03, 2006
Junichi Watanabe, Kitakyushu, JP;
Junichi Watanabe, Kitakyushu, JP;
Kabushiki Kaisha Yaskawa Denki, Kitakyushu-shi, JP;
Abstract
To provide a current controller capable of constantly detecting an offset value of a current detection system, the offset value overlapping with a current detection value, in a state of regular operation of a motor to correct the current detection value and capable of current detection with high accuracy and a current offset correction method of the same. A carrier wave peak-trough judging partis provided to discriminating the peak and the trough of a carrier wave. An A/D converted value detected in falling from the peak of the carrier wave is used as a current detection value. An A/D converted value detected in rising from the trough of the carrier wave is used as an offset value in the case that a modulated wave command is larger than a comparison standard value capable of computation by means of a calculation formula. On the basis of the current detection value and the offset value, carried out is an operation of a current detection correction value.