Electricity: measuring and testing – Impedance – admittance or other quantities representative of... – Lumped type parameters
Patent
1995-03-20
1996-05-07
Wieder, Kenneth A.
Electricity: measuring and testing
Impedance, admittance or other quantities representative of...
Lumped type parameters
324545, 340648, 318690, 364483, G01R 2100
Patent
active
055149782
ABSTRACT:
Motor current and voltage waveforms are measured and converted to digitized current and voltage waveforms. A weighted discrete fourier transform is applied to the digitized current and voltage waveforms to obtain negative sequence current and voltage phasors; and the negative sequence current and voltage phasors are used to determine the existence of a turn fault. The use of the negative sequence current and voltage phasors can be performed by employing one of several techniques. In a first embodiment, an apparent negative sequence impedance is estimated by dividing the negative sequence voltage phasor by the negative sequence current phasor for comparison with a threshold negative sequence impedance. In a second, related embodiment, a current differential is estimated by dividing the negative sequence voltage phasor by a characteristic negative sequence impedance and subtracting the result from the negative sequence current phasor for comparison with a threshold current differential. In a third, related embodiment, a voltage differential is estimated by multiplying the negative sequence current phasor by a characteristic negative sequence impedance and subtracting the result from the negative sequence voltage phasor for comparison with a threshold voltage differential. In either of the second or third embodiments, the characteristic negative sequence impedance can be obtained by inserting a calibration device into one phase of the motor.
REFERENCES:
patent: 4547726 (1985-10-01), Premerlani
patent: 4715000 (1987-12-01), Premerlani
patent: 5270640 (1993-12-01), Kohler et al.
"Alternatives for Assessing the Electrical Integrity of Induction Motors" by Jeffrey L. Kohler, et al, IEEE Transactions on Industry Applications, vol. 28, No. 5, Sep./Oct. 1992, pp. 1109-1117.
U.S. Patent Application, "Turn Fault Detection" by Kliman, Serial No. 08/285,469 filed Aug. 3, 1994.
Kliman Gerald B.
Koegl Rudolph A. A.
Premerlani William J.
Agosti Ann M.
Bowser Barry C.
General Electric Company
Snyder Marvin
Wieder Kenneth A.
LandOfFree
Stator turn fault detector for AC motor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stator turn fault detector for AC motor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stator turn fault detector for AC motor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1229648