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:
May. 01, 2001
Filed:
Oct. 19, 1999
Hitachi, Ltd., Tokyo, JP;
Abstract
In an a.c. motor control method and apparatus, operations are carried out at a current controller and a voltage setting using interrupt signals generated in synchronism with maximum and minimum values of a carrier wave at a control device for controlling an inverter for driving an alternating current motor. In operations at the voltage setting part carried out using one of the interrupt signals, a carrier wave is corrected in such a manner that phases of voltage command values gradually come into synchronism with a carrier wave. An integral multiple of the period of the carrier wave becomes the period of the a.c. voltage and current control operation timing is carried out in synchronism with the carrier wave.