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:
Jun. 26, 2007
Filed:
Nov. 22, 2005
Hideki Tanaka, Amagasaki, JP;
Shinji Kajihara, Kobe, JP;
Tsuyoshi Maehara, Itami, JP;
Tetsuya Kubota, Kobe, JP;
Hideki Tanaka, Amagasaki, JP;
Shinji Kajihara, Kobe, JP;
Tsuyoshi Maehara, Itami, JP;
Tetsuya Kubota, Kobe, JP;
Kawasaki Jukogyo Kabushiki Kaisha, Kobe, JP;
Abstract
A desired q-axis current is determined based on a desired torque, and a desired d-axis current is determined based on the rotating speed of a synchronous motor when the terminal voltage of the synchronous motor coincides with a predetermined maximum permissible voltage to weaken a magnetic field created by the synchronous motor equivalently and to prevent the drop of the output torque of the synchronous motor. The desired d-axis current is determined based on the desired torque and the rotating speed. Therefore, the desired d-axis current can be reduced when a high torque is not necessary and undesired increase of the desired d-axis current can be prevented. Thus the synchronous motor operates efficiently, heat generation of the synchronous motor is prevented and power factor is improved.