Fiber optic sensing system for grid-based assets

Patent metadata

Field	Value
Publication number	US-11719559-B2
Application number	US-201916665015-A
Country	US
Kind code	B2
Filing date	Oct 28, 2019
Priority date	Oct 24, 2019
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A sensor system includes a sensor network comprising at least one optical fiber having one or more optical sensors. At least one of the optical sensors is arranged to sense vibration of an electrical device and to produce a time variation in light output in response to the vibration. A detector generates an electrical time domain signal in response to the time variation in light output. An analyzer acquires a snapshot frequency component signal which comprises one or more time varying signals of frequency components of the time domain signal over a data acquisition time period. The analyzer detects a condition of the electrical device based on the snapshot frequency component signal.

First claim

The invention claimed is:

1. A sensor system comprising:
a sensor network comprising at least one optical fiber that includes one or more optical sensors, the optical sensors arranged to sense vibration of an electrical device and to produce a time varying light output in response to the vibration;
at least one detector configured to generate an electrical time domain signal in response to the time varying light output of at least one optical sensor of the sensor network; and
an analyzer configured to:
acquire at least one snapshot frequency component signal comprising one or more time varying signals of frequency components of the time domain signal over a data acquisition time period; and
detect a condition of the electrical device based on the snapshot frequency component signal;
wherein the electrical device is electrically connected to a power grid, and the snapshot frequency component signal includes a frequency of the power grid and one or more harmonics thereof.

2. The sensor system of claim 1 , wherein the analyzer is further configured to:
compare at least one snapshot frequency component signal to a known frequency component template corresponding to a condition of the electrical device; and
detect the presence or amount of the condition based on the comparison.

3. The system of claim 1 , wherein the analyzer is configured to perform a time-frequency transformation of the time domain signal.

4. The system of claim 1 , wherein the analyzer is configured to detect the condition based on amplitudes or amplitude ratios of frequency components of the snapshot frequency component signal.

5. The system of claim 1 , wherein the analyzer is configured to:
develop a trend of changes in the snapshot frequency component signal over time; and
detect a change in the condition based on the trend.

6. A method comprising:
optically sensing vibration of an electrical device and producing a time variation in light output from at least one optical sensor in response to the vibration;
generating an electrical time domain vibration signal representing the time variation in light output;
acquiring at least one snapshot frequency component signal comprising one or more time varying frequency components of the time domain signal over a data acquisition time period; and
detecting a condition of the electrical device based on the snapshot frequency component signal;
wherein the electrical device is electrically connected to a power grid, and the snapshot frequency component signal includes a frequency of the power grid and one or more harmonics thereof.

7. A sensor system comprising:
a sensor network comprising at least one optical fiber including one or more optical sensors, the optical sensors arranged to sense one or more parameters of an electrical device;
at least one detector configured to generate an electrical time domain signal in response to a time variation in light output of at least one optical sensor of the sensor network;
an analyzer configured to:
identify changes in a first parameter of the electrical device based on analysis of the time domain signal of the optical sensor over a first data acquisition period; and
identify changes in a second parameter of the electrical device based on analysis of the time domain signal of the optical sensor over a second data acquisition period that is shorter than the first data acquisition period;

wherein the analyzer is configured to develop a correlation between two or more different sensed parameter signals and detect a change in the presence or amount of the condition based on a change in the correlation.

8. The system of claim 7 , wherein the first parameter is internal temperature of the electrical device and the second parameter is vibration of the electrical device.

9. The system of claim 7 , wherein the first parameter is ambient temperature external and proximate to the electrical device and the second parameter is vibration of the electrical device.

10. The system of claim 7 , wherein:
the at least one optical sensor comprises multiple optical sensors;
the detector is configured to respectively detect multiple time domain signals of the multiple optical sensors over the first data acquisition period or the second data acquisition period; and
the analyzer is configured to identify a parameter distribution within the electrical device based on analysis of the multiple time domain signals over the first data acquisition period or the second data acquisition period.

11. The system of claim 10 , wherein the parameter distribution is a temperature distribution.

12. The system of claim 7 , wherein the analyzer is configured to:
develop a correlation between vibration signals at different sensing points; and
detect a change in the presence or amount of the condition based on a change in the correlation.

13. The method of claim 7 , wherein the two or more different sensed parameter signals include a vibration signal and a temperature signal.

14. A sensor system comprising:
a sensor network comprising at least one optical fiber including one or more optical sensors, the optical sensors arranged to sense one or more parameters of an electrical device;
at least one detector configured to generate an electrical time domain signal in response to a time variation in light output of at least one optical sensor of the sensor network;
an analyzer configured to:
identify changes in a first parameter of the electrical device based on analysis of the time domain signal of the optical sensor over a first data acquisition period; and
identify changes in a second parameter of the electrical device based on analysis of the time domain signal of the optical sensor over a second data acquisition period that is shorter than the first data acquisition period;

wherein the analyzer is configured to develop a correlation between vibration signals at different sensing points and detect a change in the presence or amount of the condition based on a change in the correlation.

Assignees

• Palo Alto Res Ct Inc

Inventors

• Kiesel Peter
• Raghavan Ajay
• Karin Todd
• Chen Qiushu

Classifications

• G01D5/35345 Primary

  using Amplitude variations to detect the measured quantity · CPC title

• G01K11/32

  using changes in transmittance, scattering or luminescence in optical fibres · CPC title

• G01L1/242

  the material being an optical fibre · CPC title

• G01R31/62

  Testing of transformers · CPC title

• G01D5/35312 Primary

  using a Fabry Perot · CPC title