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:
Jan. 05, 2016
Filed:
Oct. 15, 2011
Zhi Gao, Wake Forest, NC (US);
Larry A. Turner, Chapel Hill, NC (US);
Benoit Leprettre, Latronche, FR;
Roy S. Colby, Raleigh, NC (US);
Zhi Gao, Wake Forest, NC (US);
Larry A. Turner, Chapel Hill, NC (US);
Benoit Leprettre, Latronche, FR;
Roy S. Colby, Raleigh, NC (US);
SCHNEIDER ELECTRIC USA, INC., Schaumburg, IL (US);
Abstract
A method and apparatus to dynamically and adaptively demodulate induction motor instantaneous rotor slot harmonic frequency for line-connected squirrel-cage polyphase induction motors. The instantaneous rotor slot harmonic frequency carries essential information on the instantaneous rotor speed. Based on a correlation between the motor's input power and its rotor slot harmonic frequency, a dynamically varying carrier frequency is computed and used in a rotor slot harmonic frequency detector. The rotor slot harmonic frequency detector is based on a superheterodyne principle. It contains a generalized linear-phase low-pass filter, whose bandwidth is estimated dynamically by a filter bandwidth estimator. The rotor slot harmonic frequency detector also includes a latency compensator, which receives the dynamically varying carrier frequency signal and synchronizes it with the output of a frequency demodulator.