Data processing: measuring – calibrating – or testing – Measurement system in a specific environment – Electrical signal parameter measurement system
Patent
1997-09-29
1998-11-03
Voeltz, Emanuel Todd
Data processing: measuring, calibrating, or testing
Measurement system in a specific environment
Electrical signal parameter measurement system
702 75, 702 76, 702 66, 702112, 341123, 324 7628, 324 7655, 324 7647, 324 7648, G01R 2310, G01R 2316
Patent
active
058324143
ABSTRACT:
A new method of compensating for errors in phasor estimation due to oscillations caused by discrete fourier transforms used to estimate signal frequency is provided. The method uses a variable N-point DFT to compute one or more phasors based on data acquired from one or more sampled signals. At each sampling interval the change in phasor angle between the current sampling interval and the previous sampling interval is determined and used to estimate the instantaneous frequency of the signal. A non-oscillating phasor indicative of the instantaneous magnitude, angular frequency, and phase angle of the signal is generated based on the instantaneous frequency estimate. Instantaneous frequencies are averaged over a cycle of the signal to generate an average cycle frequency. In addition, a number of discrete frequencies and corresponding DFT windows based on a fixed sampling rate and a predetermined fundamental frequency of the signal are defined and used in estimating the instantaneous frequency. The DFT window is adjusted by setting it equal to the DFT window corresponding to the discrete frequency closest to the average cycle frequency. A generator protection system analyzing voltage and current signals output from a generator is also provided. The voltage and current signals are monitored by respective voltage and current sensors to produce a plurality of signals representative of voltage and current characteristics of the generator. The system comprises components for receiving and sampling signal input, and for processing the samples according to the inventive method.
REFERENCES:
D. Hart and J. Stoupis, Protection Algorithms for the GPU, Task Report III, ABB Transmission Technology Institute Task Report, PSC 96-R-0035, Sep. 17, 1996.
D. Hart, Y. Hu, and D. Novosel, Protection Algorithms for the GPU, Task Report I, ABB Transmission Technology Institute Task Report PSC 95-R-0013, Mar. 24, 1995.
D. Hart et al., A New Frequency Tracking and Phasor Estimation Algorithm for Generator Protection, IEEE Transactions on Power Delivery, vol. 12, No. 3, Jul. 1997.
"Field Experience with a Digital Relay for Synchronous Generators,"89 SM
"Performance Assessment of A new Digital Subsystem for Generator 08/574,357, filed Dec. 18, 1995!.
"A New Measurement Technique for Tracking Voltage Phasors,Local System Frequency, and Rate of Change of Frequency," IEEE Transactions on Power case 08/574,357, filed Dec. 18, 1995!.
"An Adaptive Sampling-Interval Generator for Digital Relaying," IEEE parent case 08/574,357, filed Dec. 18, 1995!.
Hart David G.
Novosel Damir
Stoupis James D.
ABB Power T&D Company Inc.
Nguyen Cuong H.
Todd Voeltz Emanuel
LandOfFree
Generator protection system and method of compensating for error does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Generator protection system and method of compensating for error, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Generator protection system and method of compensating for error will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-703445