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. 10, 2001
Filed:
Mar. 01, 2000
Toshiyuki Kaitani, Tokyo, JP;
Tetsuaki Nagano, Tokyo, JP;
Tsutomu Kazama, Tokyo, JP;
Masanori Ozaki, Tokyo, JP;
Fumio Kumazaki, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
There is provided a controlling device for an AC motor having a structure in which a current of a three phase brushless DC motor is detected and then converted to a rotor coordinate system, to separately control a torque split current (q axis) and an exciting split current (d axis), wherein an offset is estimated with a DC component of a multiplied value of the values corresponding to a d axis voltage command which is an output of an exciting split current controller and an electrical angle, and the detected current is compensated for, so that an offset of a current detector may be estimated and compensated for during its operation without stopping its rotation and the motor can rotate smoothly without a torque ripple, even in the case in which the current detector has an offset error or in the case in which an offset changes due to a temperature drift.