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:
Nov. 30, 1999
Filed:
Feb. 13, 1998
Satoru Kaneko, Urizura-machi, JP;
Ryoso Masaki, Hitachi, JP;
Yuusuke Takamoto, Hitachi, JP;
Taizou Miyazaki, Hitachi, JP;
Sanshiro Obara, Toukai-mura, JP;
Hitachi, Ltd., , JP;
Abstract
A power corresponding to an A/C voltage command id1* is applied in the d-axis direction of rotational coordinates of a stopped synchronous motor via a current control unit, a three-phase converting unit, and a power converter. Further, by using 'an amplitude value of a current iq' in the q-axis direction of the rotational coordinates generated in response to the A/C voltage command id1*' which is fed back and detected via a current detector and a dq converting unit, a field pole position estimation value .theta. is converged. The field pole position is estimated by using the converged field pole position estimation value .theta. as a true value of the field pole position .theta. of the synchronous motor.