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:
Feb. 10, 2004
Filed:
Jan. 24, 2002
Applicant:
Inventors:
Yoshitaka Iwaji, Tokyo, JP;
Tsunehiro Endo, Tokyo, JP;
Kiyoshi Sakamoto, Tokyo, JP;
Yuhachi Takakura, Tokyo, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P 1/46 ; H02P 5/28 ; H02P 7/36 ;
U.S. Cl.
CPC ...
H02P 1/46 ; H02P 5/28 ; H02P 7/36 ;
Abstract
A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.