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. 19, 1995
Filed:
Mar. 31, 1993
Michael Mann, Berlin, DE;
Karl-Heinz Glahe, Berlin, DE;
Otis Elevator Company, Farmington, CT (US);
Abstract
Torque current reference I.sub.Tref and reference acceleration a.sub.ref are sampled in a vector controlled induction motor drive for developing a quality criterion by which an estimated rotor time constant .tau..sub.2 may be adapted to the actual rotor time constant .tau..sub.2. More specifically, the torque current reference I.sub.Tref and reference acceleration a.sub.ref are sampled and then a slope of I.sub.Tref versus a.sub.ref is plotted against the offset of that line, which offset is proportional to the lead torque T.sub.LOAD. The no-load slope is then determined from this plot and subtracted from an ideal no-load slope and the difference passed through a proportional-integral circuit for providing an estimated rotor time constant .tau..sub.2 which is adapted to the actual rotor time constant .tau..sub.2.