Power monitoring system and method
First Claim
1. A system, comprising:
- a data recorder to monitor an electrical power transmission, said data recorder including;
a plurality of analog input channels;
a converter to digitize an analog signal from at least one of said analog input channels;
a signal analysis subsystem responsive to said converter to provide;
(a) a first data stream at a first rate, said first data stream being a digitized form of said analog signal;
(b) a second data stream calculated from said first data stream, said second data stream including a phasor representation of said analog signal and being provided at a second rate slower rate than said first rate;
(c) a trigger signal responsive to a predetermined condition of said first data stream or said second data stream representative of an electrical power transmission anomaly; and
wherein said subsystem is operable to generate a data record in response to said trigger signal, said data record including a prefault data segment corresponding to a time period before said anomaly starts and a postfault data segment corresponding to a time period after said anomaly ceases, said prefault data segment and said postfault data segment each including at least a portion of said first data stream and said second data stream.
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Accused Products
Abstract
A uniquely configured electrical power transmission data recorder system generates a first data stream. The first data stream is a digitized form of an electric power signal being monitored. The data recorder calculates a second data stream from the first data stream. The second data stream is a phasor representation of the electrical power signal being monitored. Vectors of the second data stream are provided at a lower frequency than vectors of the first data stream. The data recorder system associates different fault triggers with each of the data streams. When the data recorder detects a condition that activates one or more of the fault triggers, it generates a power fault record. The power fault record has a prefault portion corresponding to a time period before a fault is detected and a postfault portion corresponding to a time period after the fault ceases. The system may include a number of different processors dedicated to different power monitoring and data recording tasks.
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Citations
30 Claims
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1. A system, comprising:
- a data recorder to monitor an electrical power transmission, said data recorder including;
a plurality of analog input channels;
a converter to digitize an analog signal from at least one of said analog input channels;
a signal analysis subsystem responsive to said converter to provide;
(a) a first data stream at a first rate, said first data stream being a digitized form of said analog signal;
(b) a second data stream calculated from said first data stream, said second data stream including a phasor representation of said analog signal and being provided at a second rate slower rate than said first rate;
(c) a trigger signal responsive to a predetermined condition of said first data stream or said second data stream representative of an electrical power transmission anomaly; and
wherein said subsystem is operable to generate a data record in response to said trigger signal, said data record including a prefault data segment corresponding to a time period before said anomaly starts and a postfault data segment corresponding to a time period after said anomaly ceases, said prefault data segment and said postfault data segment each including at least a portion of said first data stream and said second data stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- a data recorder to monitor an electrical power transmission, said data recorder including;
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10. A method, comprising:
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digitally sampling an electrical waveform corresponding to an electrical power transmission to generate a first data stream of waveform samples at a first rate;
calculating a second data stream from the first data stream with a first processor, the second data stream corresponding to a phasor representation of the waveform, the second data stream being provided at a second rate slower than the first rate by a predetermined amount;
buffering the first and second data streams in a first memory;
accessing the first memory with a second processor to periodically derive a first set of values to add to the first data stream and a second set of values to add to the second data stream; and
generating a power disturbance record, the record including at least a prefault portion and a postfault portion of one of the first and second data streams after said accessing. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A method, comprising:
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digitally sampling an electrical waveform corresponding to an electrical power transmission to generate a first data stream of waveform samples at a first rate;
calculating a second data stream from the first data stream, the second data stream being representative of the waveform and being provided at a second rate, the second rate being slower than the first rate by a predetermined amount;
evaluating the first data stream to detect a first type of power transmission disturbance and the second data stream to detect a second type of power transmission disturbance; and
generating a power disturbance record in response to said evaluating, the record including at least a prefault portion and a postfault portion of each of the first and second data streams. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
said evaluating includes periodically deriving a first set of values from the first data stream and a second set of values from the second data stream; and
said generating includes providing at least a portion of one of the first or second sets of values in the record.
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22. The method of claim 17, further comprising generating a third data stream at a third rate, the third rate being slower than the second rate, and the third data stream including a phasor representation of the electrical waveform.
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23. The method of claim 17, further comprising detecting a number of trigger conditions separated in time during said evaluation and storing a record for each of the trigger conditions in a memory.
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24. The method of claim 17, wherein said digitally sampling, said calculating, and said evaluating are performed by a data recorder, the data recorder further including a number of analog input channels, a number of discrete inputs, and a number of discrete outputs, the data recorder being operatively coupled to a central processing unit.
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25. The method of claim 24, further comprising transmitting the record from the data recorder to the central processing unit.
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26. The method of claim 24, wherein the recorder includes a first processor performing said calculating, a second processor performing said evaluating, a third processor assembling the record, and a shared memory operatively coupled to the first, second, and third processors.
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27. A data recording system, comprising:
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a data recorder to sense at least three analog waveforms corresponding to a three-phase electrical power transmission;
first means for sampling at least one of the waveforms to generate a first data stream of waveform samples at a first rate;
second means for calculating a second data stream from the first data stream, the second data stream corresponding to a phasor representation of the waveform, the second data stream being provided at a second rate slower than the first rate by a predetermined amount;
third means for evaluating the first and second data streams to correspondingly include a first set of derived values in the first data stream and a second set of derived values in the second data stream; and
fourth means for generating a power anomaly record, the record including at least a prefault portion and a postfault portion, the prefault and postfault portions each including at least a portion of one of the first data stream and the second data stream. - View Dependent Claims (28, 29, 30)
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Specification