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. 11, 2012
Filed:
Jun. 18, 2009
Semyon Royak, Beachwood, OH (US);
Mark M. Harbaugh, Richfield, OH (US);
Thomas A. Nondahl, Wauwatosa, WI (US);
Jingbo Liu, Grafton, WI (US);
Peter B. Schmidt, Franklin, WI (US);
Robert J. Breitzmann, South Russel, OH (US);
Semyon Royak, Beachwood, OH (US);
Mark M. Harbaugh, Richfield, OH (US);
Thomas A. Nondahl, Wauwatosa, WI (US);
Jingbo Liu, Grafton, WI (US);
Peter B. Schmidt, Franklin, WI (US);
Robert J. Breitzmann, South Russel, OH (US);
Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US);
Abstract
The present invention provides an improved current regulator for PWM based drives for electric motors. The invention provides compensation for the rotor position signal for delays introduced due to the PWM algorithm and for digital sampling present in such a drive. Current regulator commonly operate in a two-phase reference frame, requiring forward and reverse coordinate transformations between the physical current values and the two-phase reference frame variables. The present invention provides an improved compensation in the forward transformation by determining the phase lag between the commanded voltage reference and the output voltage reference and by further compensating the forward transformation for errors introduced due to sampling the current either at different sampling instances than the rotor position or at multiple sampling instances during a carrier period. Additionally, compensation during the reverse transformation is provided to compensate for errors introduced due to sampling the current and rotor position.