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:
Dec. 28, 1993
Filed:
Nov. 12, 1992
Daniel E Utley, Anderson, IN (US);
Kevin M Deasy, Noblesville, IN (US);
Gordon D Cheever, Jr, Kokomo, IN (US);
General Motors Corp., Detroit, MI (US);
Delco Electronics Corporation, Kokomo, IN (US);
Abstract
An improved digital PWM closed-loop current control for a multiple phase winding AC machine which requires only a single sensor for monitoring the current in one of the phase windings of the machine. The PWM on-time values for the various phase windings of the machine are stored in a single look-up table as a function of stator position and requested current amplitude, and the on-times used to schedule phase winding energization are periodically updated using a two-part look-up procedure. Initially, the stored on-time value for a single phase winding is retrieved from the table as a function of stator position and the requested current amplitude. The retrieved value is then compared with a measure of the actual current in the respective phase winding to form an error signal, which is used to adjust the requested current amplitude. The requested current amplitude, as adjusted, is then used, along with the stator position, as a table look-up parameter to retrieve PWM on-times for all three phase windings, thereby automatically adjusting multiple phase winding currents in a balanced fashion.