Fiber optic sensing system for grid-based assets

Patent metadata

Field	Value
Publication number	US-2021123797-A1
Application number	US-202016773181-A
Country	US
Kind code	A1
Filing date	Jan 27, 2020
Priority date	Oct 24, 2019
Publication date	Apr 29, 2021
Grant date	—

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

1 . A sensor system comprising:
a sensor network comprising at least one optical fiber that includes one or more optical sensors including at least one vibration sensor, the vibration sensor disposed within a power grid electrical device and configured to sense vibration of the power grid electrical device; at least one detector configured to generate an electrical time domain signal in response to a time variation in light output from the vibration sensor; and an analyzer configured to:
acquire one or more snapshot frequency component signals, each snapshot frequency component signal comprising a time varying signal of frequency components of the time domain signal over a data acquisition time period; and
detect a presence or amount of the condition based on the snapshot frequency component signal.

2 . The system of claim 1 wherein the vibration sensor or the optical fiber is rigidly attached to a component of the power grid electrical device.

3 . The system of claim 2 wherein:
the power grid electrical device is an oil-filled transformer; and
the component of the oil-filled transformer includes a core, an oil tank wall, an oil tank lid, a low voltage plate or a frame of the oil-filled transformer.

4 . The system of claim 2 wherein vibration sensor is mounted to two components of the power grid electrical device and arranged to sense relative movement of the two components.

5 . The system of claim 2 wherein the optical fiber is mounted to two components of the power grid electrical device such that the vibration sensor is disposed between two components of the power grid electrical device.

6 . The system of claim 5 wherein the power grid electrical device is a transformer and the two components are a first core and a second core of the transformer.

7 . The system of claim 5 wherein the power grid electrical device is a transformer and the two components are a core and a frame of the transformer.

8 . The system of claim 1 wherein the power grid electrical device is a transformer and the vibration sensor is in oil within the transformer and is not rigidly attached to a transformer component.

9 . The system of claim 1 wherein the sensor network also includes a temperature sensor.

10 . The system of claim 1 wherein the power grid electrical device is an oil-filled transformer and the sensor network includes at least one temperature sensor positioned proximate to an oil tank wall of the oil-filled transformer.

11 . The system of claim 1 wherein the power grid electrical device is and oil-filled transformer and the sensor network includes at least one temperature sensor positioned in a headspace above oil within the oil-filled transformer.

12 . The system of claim 1 wherein the power grid electrical device is an oil-filled transformer and the sensor network includes at least one temperature sensor positioned proximate to a surface of oil within the oil-filled transformer.

13 . The system of claim 1 wherein the power grid electrical device is an oil-filled transformer and the sensor network includes at least one temperature sensor positioned proximate to a bottom of an oil tank of the transformer.

14 . The system of claim 1 wherein the power grid electrical device is a transformer and the sensor network includes at least one temperature sensor positioned proximate to a top of a coil of the transformer, proximate to a middle of the coil, and/or proximate a bottom of the coil.

15 . The system of claim 1 , wherein the power grid electrical device is an oil-filled transformer and the sensor network includes an oil level sensor.

16 . The system of claim 1 , wherein the sensor network includes one or more external sensors disposed external to the power grid electrical device.

17 . The system of claim 16 , wherein the one or more external sensors comprise environmental sensors.

18 . The system of claim 1 wherein the optical fiber is disposed on or in a rod inserted through an opening in a case of the power grid electrical device.

19 . The system of claim 18 wherein the optical fiber includes at least one optical temperature sensor and at least one oil level sensor.

20 . The system of claim 18 wherein the rod comprises polycarbonate.

21 . The system of claim 18 wherein:
the power grid electrical device is a transformer;
the rod is mounted to an internal component of the transformer; and
the optical fiber exits the transformer through a plug fitting.

22 . The system of claim 21 wherein:
a plug is disposed in the opening; and
the optical fiber is disposed through a hole in a plug.

23 . The system of claim 22 wherein the opening is a national pipe tapered thread (NPT) opening and the plug is an NPT plug.

24 . The system of claim 22 further comprising a hermetic seal configured to hermetically seal the hole in the plug.

25 . A system comprising:
a sensing rod configured to be inserted through a case of a power grid electrical device, the rod having at least one optical fiber disposed in or on the rod, the optical fiber including multiple optical sensors.

26 . The system of claim 25 wherein:
the rod is attached to a threaded plug; and
the case has a threaded opening configured to receive the plug.

27 . The system of claim 26 wherein the threaded plug has a hole extending through the plug and the optical fiber extends through the hole.

28 . The system of claim 27 further comprising a hermetic seal configured to hermetically seal the hole.

29 . The system of claim 1 , wherein the power grid electrical device comprises an oil-filled transformer, the oil-filled transformer comprising:
a transformer case configured to contain oil; and insulation material including one or more oil ducts disposed within the transformer case; and the at least one optical fiber extends at least partially through at least one of the oil ducts.

30 . A device comprising:
an oil-filled electrical device comprising:
a case configured to contain oil; and
insulation material including one or more oil ducts disposed within the case; and
at least one optical fiber extending through at least one of the oil ducts.

31 . The device of claim 30 wherein:
the power grid electrical device is a transformer that includes a first coil and a second coil; and
the oil ducts are positioned between the first coil and the second coil.

32 . The device of claim 30 wherein the insulation material is paper.

33 . A sensor system comprising:
a sensor network comprising at least one optical fiber that includes one or more optical vibration sensors, the optical sensors arranged to sense vibration of an power grid 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; and an analyzer configured to:
identify eigenfrequencies of the electrical device represented in the time domain signal; and
detect a presence or amount of a condition of the power grid electrical device based on a change in the eigenfrequencies.

Assignees

• Palo Alto Res Ct Inc
• Gen Electric

Inventors

• Kiesel Peter
• Raghavan Ajay
• Karin Todd
• Chen Qiushu
• Smith Jr Malcolm G
• Stinson Iv Robert T

Classifications

• H01F2027/406

  Temperature sensor or protection · CPC title

• H01F27/12

  Oil cooling · CPC title

• G01L1/246

  using integrated gratings, e.g. Bragg gratings · CPC title

• G01K11/3206

  at discrete locations in the fibre, e.g. using Bragg scattering · CPC title

• G01D5/35374

  Particular layout of the fiber · CPC title