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. 18, 1997
Filed:
May. 13, 1996
Kabushiki Kaisha Meidensha, Tokyo, JP;
Abstract
To extend an operable range of a hybrid excitation type permanent magnet synchronous motor having a field of a permanent magnet and a dc excitation coil, magnetic flux of the field is controlled so as to keep constant when a rotation speed of the motor is smaller than a predetermined base speed and so as to change in reverse proportion with the rotation speed of the motor when the rotation speed is larger than the predetermined base speed. Electric current and voltage to an armature of the motor is controlled such that a current ratio of a direct-axis component and a quadrature-axis component which components are obtained by dividing an electric current to the armature coil into the direct-axis component and the quadrature-axis component relative to the voltage induced in the armature coil, is kept constant.