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:
Nov. 02, 1999
Filed:
Nov. 17, 1998
Applicant:
Inventors:
Robert J DeLange, St. Francis, WI (US);
David J Cisler, Wauwatosa, WI (US);
Assignee:
Allen-Bradley Company, LLC, Milwaukee, WI (US);
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318801 ; 318807 ; 318809 ; 318811 ;
Abstract
A method and apparatus for minimizing motor instability under no load conditions, the method including identifying instability by comparing consecutive current half cycle periods and, where the difference between half cycle periods is sufficiently large, determining that instability exists and modifying controller modulating waveforms by reducing waveform magnitude until stability is achieved. Preferably the apparatus for achieving stability includes only a single current zero crossing sensor to minimize hardware costs.