Line fault signature analysis

Patent metadata

Field	Value
Publication number	US-10564206-B2
Application number	US-201916520518-A
Country	US
Kind code	B2
Filing date	Jul 24, 2019
Priority date	Dec 16, 2016
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

In described examples, a time-domain analyzer is arranged to generate an indication of a number of high-frequency events of an electrical monitor signal that includes a fundamental periodic frequency. The high-frequency events include frequencies higher than the fundamental periodic frequency. A frequency-domain analyzer is arranged to generate frequency band information in response to frequencies of the electrical monitor signal that are higher than the fundamental periodic frequency. A fault detector is arranged to monitor the indication of the number of high-frequency events and the generated frequency band information, and to generate a fault flag in response to the monitored indication of the number of high-frequency events and the generated frequency band information.

First claim

What is claimed is:

1. A system comprising:
a first analyzer configured to:
receive a monitor signal having a fundamental frequency; and
generate a count of a number of events of the monitor signal having a respective frequency greater than the fundamental frequency;

a second analyzer configured to:
receive the monitor signal; and
generate frequency information for the monitor signal; and

a fault detector coupled to the first analyzer and the second analyzer and configured to:
receive the count of the number of events and the frequency information; and
generate a flag in response to the count of the number of events and the frequency information.

2. The system of claim 1 , wherein the first analyzer includes:
a high-pass filter configured to receive the monitor signal;
a comparator coupled to the high-pass filter and configured to compare an output of the high-pass filter with a threshold voltage; and
an event counter coupled to the comparator and configured to generate the count of the number of events in response to the comparator.

3. The system of claim 1 , wherein the second analyzer includes a wave segment determinator configured to divide the monitor signal into wave segments.

4. The system of claim 3 , wherein the fault detector is configured to wake in response to the count of the number of events exceeding a threshold during one of the wave segments.

5. The system of claim 3 , wherein:
the wave segment determinator is further configured to determine a zero crossing of the monitor signal; and
the second analyzer further includes a digital signal processor configured to:
wake in response to a current wave segment of the wave segments being proximate to the zero crossing of the monitor signal; and
generate the frequency information for the monitor signal.

6. The system of claim 1 , wherein:
the monitor signal corresponds to an alternating current power line; and
the fundamental frequency is selected from a group consisting of about 60 Hz and about 50 Hz.

7. The system of claim 1 , wherein the fault detector includes a signature library that includes time-domain and frequency-domain signatures for indicating thresholds for fault conditions of a power line monitored by the monitor signal.

8. A device comprising:
a set of inputs to receive a monitor signal having a fundamental frequency;
a first analyzer coupled to the set of inputs and configured to provide a count of events in the monitor signal having a respective frequency greater than the fundamental frequency;
a second analyzer coupled to the set of inputs and configured to provide frequency data of the monitor signal; and
a fault detector coupled to the first analyzer and the second analyzer and configured to:
wake in response to the count of events exceeding a threshold; and
upon waking, assert a flag in response to the count of events and the frequency data.

9. The device of claim 8 , wherein the fault detector includes a signature library and is further configured to assert the flag based on a comparison of a property of the monitor signal to the signature library.

10. The device of claim 9 , wherein:
the frequency data represents energy in the monitor signal at each of a set of frequencies; and
the property compared by the fault detector includes the energy in the monitor signal at each of the set of frequencies.

11. The device of claim 9 , wherein:
the second analyzer includes a wave segment determinator configured to:
determine a zero crossing of the monitor signal; and
divide the monitor signal into wave segments; and

the property compared by the fault detector includes a proximity of a current wave segment of the wave segments to the zero crossing.

12. The device of claim 8 , wherein the first analyzer includes:
a high-pass filter coupled to the set of inputs;
a comparator coupled to the high-pass filter and to a threshold voltage; and
an event counter coupled to the comparator to provide the count of events in response to the comparator.

13. The device of claim 8 , wherein the second analyzer includes:
a low-pass filter coupled to the set of inputs;
an analog-to-digital converter coupled to the low-pass filter; and
a processor coupled to the analog-to-digital converter to provide the frequency data in response to the analog-to-digital converter.

14. The device of claim 13 , wherein:
the second analyzer further includes a wave segment determinator configured to:
determine a zero crossing of the monitor signal; and
divide the monitor signal into wave segments; and

the processor is configured to wake in response to a current wave segment of the wave segments being proximate to the zero crossing.

15. The device of claim 8 further comprising a level shifter coupling each of the first analyzer and the second analyzer to the set of inputs.

16. A method comprising:
receiving a sensor signal having a fundamental frequency;
determining a count of events in the sensor signal having a frequency greater than the fundamental frequency;
determining frequency band information representing energy in each of a set of frequency bands;
generating a flag in response to the count of events and the frequency band information.

17. The method of claim 16 , wherein:
the generating of the flag is performed by a processor; and
the method further comprises waking the processor in response to the count of events exceeding a threshold.

18. The method of claim 16 further comprising dividing the sensor signal into wave segments, and wherein the count of events is within a given wave segment of the wave segments.

19. The method of claim 18 , wherein:
the determining of the frequency band information is performed by a processor; and
the method further comprises waking the processor in response to a current segment of the wave segments being proximate to a zero crossing of the sensor signal.

20. The method of claim 19 , wherein the generating of the flag is further based on the current segment being proximate to the zero crossing of the sensor signal.

Assignees

• Texas Instruments Inc

Inventors

• Rajagopal Prasanna U
• Sreenivasa Kallikuppa M
• Kumbasi Amit G

Classifications

• G01R19/2513

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title

• G01R31/2612

  for measuring frequency response characteristics, e.g. cut-off frequency thereof · CPC title

• G01R31/08

  Locating faults in cables, transmission lines, or networks · CPC title

• G01R31/022 Primary

  Physics · mapped topic

• G01R31/024

  Physics · mapped topic