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. 24, 2003
Filed:
Oct. 11, 2001
Tomokuni Iijima, Osaka, JP;
Kazushige Narazaki, Katano, JP;
Toru Tazawa, Ibaraki, JP;
Ichiro Oyama, Osaka, JP;
Yukinori Maruyama, Kadoma, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A method for position-sensorless motor control is provided, wherein a rotor-position estimation current signal is superimposed on the &ggr;-axis direction component of a target current vector representing target currents of stator windings. The period of the current signal is an even multiple of a PWM carrier period and varies at random. The amplitude of the current signal increases with the amplitudes of the target currents. An even number of samples are obtained from the &dgr;-axis direction component of a current vector representing detected currents of the stator windings in each period of the current signal. A discrete Fourier integration of the samples determines the amplitude of a current response to the current signal in the &dgr;-axis direction. The &ggr;-axis direction is corrected so that the current response substantially shrinks to zero in the &dgr;-axis direction.