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:
Sep. 09, 2008
Filed:
Jul. 02, 2003
Hideaki Iura, Fukuoka, JP;
Kazuhiro Nonaka, Fukuoka, JP;
Yuichi Terazono, Fukuoka, JP;
Yoichi Yamamoto, Fukuoka, JP;
Satoshi Sueshima, Fukuoka, JP;
Katsushi Terazono, Fukuoka, JP;
Mitsujiro Sawamura, Fukuoka, JP;
Hideaki Iura, Fukuoka, JP;
Kazuhiro Nonaka, Fukuoka, JP;
Yuichi Terazono, Fukuoka, JP;
Yoichi Yamamoto, Fukuoka, JP;
Satoshi Sueshima, Fukuoka, JP;
Katsushi Terazono, Fukuoka, JP;
Mitsujiro Sawamura, Fukuoka, JP;
Kabushiki Kaisha Yaskawa Denki, Tokyo, JP;
Abstract
It is the objective of the present invention to provide a sensorless vector control method and a control apparatus, for an alternating-current motor, that can smoothly restart an alternating-current motor in the free running state. According to the present invention, when a current that flows in an alternating-current motor () at a restart timethe alternating-current motor () continuously flows at a designated current level or higher for a designated period of time, it is determined that the rotational direction or the velocity of the alternating-current motor () is incorrectly estimated, and a direct current or a direct-current voltage is again applied to again estimate the rotational direction and the velocity.