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:
Oct. 21, 2003
Filed:
Jun. 13, 2001
Applicant:
Inventors:
Vinodkumar Sadasivam, Saint Louis, MO (US);
Keith Hoemann, Fenton, MO (US);
Bret Clark, St. Louis, MO (US);
Assignee:
Emerson Electric Co., St. Louis, MO (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P 1/24 ;
U.S. Cl.
CPC ...
H02P 1/24 ;
Abstract
An induction motor control system senses the zero-cross angle of a current waveform applied to the motor's phase windings and computes the difference between the sensed current zero-cross angle and a predetermined demand voltage angle to estimate a power factor angle. The estimated power factor angle is compared to a predetermined desired power factor angle, and the voltage applied to the phase windings is adjusted in response to the difference between the estimated power factor angle and the desired power factor angle.