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:
Aug. 17, 2004
Filed:
Apr. 17, 2002
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A control device for an induction motor controlling torque generation of the induction motor with high precision includes a rotation speed detector which detects the rotation speed of the induction motor, a current detector which detects a primary current of the induction motor; an amplifying unit which amplifies deviation between an estimated primary current obtained from a magnetic flux observing device and the primary current obtained from the current detector; a magnetic flux observing device which estimates an estimated secondary magnetic flux and an estimated primary current of the induction motor based upon the rotation speed obtained from the rotation speed detector, the primary voltage of the induction motor and the deviation signal obtained from the amplifying unit, and a control unit which controls a voltage applied to the induction motor based upon the estimated secondary magnetic flux obtained from the magnetic flux observing device. In this arrangement, the amplifying unit amplifies the deviation of the primary current based upon feedback gains consisting of eight respectively independent factors. Thus, it is possible to provide torque control with high precision even at the time of low-speed operation.