Electricity: motive power systems – With signals – meters – recorders or testing devices
Reexamination Certificate
2011-03-22
2011-03-22
Ip, Paul (Department: 2837)
Electricity: motive power systems
With signals, meters, recorders or testing devices
C318S781000, C318S802000, C318S807000, C363S039000
Reexamination Certificate
active
07911170
ABSTRACT:
The present invention relates to a device (20) and a method for sensorless measuring a mechanical rotor frequency of a rotor (6) of an asynchronous machine (40), wherein the rotor (6) has a predetermined defect and the asynchronous machine (40) has a fixed number of pairs of poles. The asynchronous machine (40) comprises a current determination unit (2) for determining a stator current of the stator (7), wherein the stator current has a stator frequency. A processing unit (3) forms a stator current spectrum of the stator current. An analyzing unit (4) analyzes the stator current spectrum and determines an inverse peak (26) and a corresponding inverse frequency in the stator current spectrum, wherein the inverse peak (26) is the peak having the second highest amplitude in the stator current spectrum in the frequency range of the stator frequency. A calculation unit (5) calculates a mechanical rotor frequency of the rotor (6) from the sum of the stator frequency divided by the number of pairs of poles and the inverse frequency, if the slip of the asynchronous machine (40) is lower than 50%, or from the difference of the stator frequency divided by the number of pairs of poles and the inverse frequency, if the slip is higher than 50%.
REFERENCES:
patent: 5565752 (1996-10-01), Jansen et al.
patent: 5828210 (1998-10-01), Kliman et al.
patent: 5883487 (1999-03-01), Rosenzweig et al.
patent: 6058596 (2000-05-01), Jansen et al.
patent: 6208132 (2001-03-01), Kliman et al.
patent: 6232692 (2001-05-01), Kliman
patent: 7746039 (2010-06-01), Hoffmann et al.
patent: 2004/0054485 (2004-03-01), Dragomir-Daescu et al.
patent: 2008/0136380 (2008-06-01), Hoffmann et al.
patent: 2008/0174195 (2008-07-01), Tupper et al.
patent: 2008/0291705 (2008-11-01), Alacoque
patent: 2010/0027302 (2010-02-01), Bauer et al.
patent: 2010/0052626 (2010-03-01), Tupper et al.
patent: 2010/0079104 (2010-04-01), Becker et al.
patent: 2921724 (1980-12-01), None
patent: 19823787 (1999-12-01), None
Hurst et al: “A Comparison of Spectrum Estimation Techniques For Sensorless Speed Detection in Induction Machines”; IEEE Transaction of Industry Applications, vol., No. 4, Jul./Aug. 1997, Whole Document, XP011022233.
Jansen et al: “Transducerless Position and Velocity Estimation in Induction and Salient AC Machines”; Industry Applications Society Annual Meeting, 1994, Denver, CO., Oct. 2-6, 1994, IEEE, pp. 488-495, XP010124039.
Arsova Silvana
Hauttmann Stefan
Ip Paul
Koninklijke Philips Electronics , N.V.
LandOfFree
Sensorless measurement of the rotation frequency of a rotor... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sensorless measurement of the rotation frequency of a rotor..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sensorless measurement of the rotation frequency of a rotor... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2753108