Fiber optic sensing system for grid-based assets

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.