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:
Mar. 16, 1999
Filed:
Dec. 22, 1997
Roy Stephen Colby, Raleigh, NC (US);
Alberto Vecchiotti, Middletown, CT (US);
Leslie M Lamontagne, Prospect, CT (US);
Otis Elevator Company, Farmington, CT (US);
Abstract
An elevator controller 7 is provided with logic 48 which automatically calculates a motor time constant (.tau..sub.R), a torque constant (K.sub.T *), and a magnetizing current (Id) for a field-oriented motor/drive system by calculating a transient inductance L.sigma., injecting a variable input frequency sinewave into a q-axis reference current I.sub.qREF and varying the input frequency while calculating an imaginary part of a rotor impedance Imag(Z.sub.R) to obtain a frequency (F.sub.PEAK) at which the maximum value of Imag(Z.sub.R) occurs, then calculating .tau..sub.R from F.sub.PEAK. K.sub.T *, Id, and a total motor voltage V.sub.M are calculated and Id is varied until a ratio of rated motor voltage (Vph.sub.-- RATED) to V.sub.M is within a predetermined tolerance of one. The procedure is performed with the rotor locked.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile