Online fiber optic sensor for detecting partial discharge and similar events in large utility station transformers and the like

• US 20050194979A1
• Filed: 03/05/2004
• Published: 09/08/2005
• Est. Priority Date: 03/05/2004
• Status: Active Grant

• Current Assignee: New Jersey Institute of Technology, Public Service Electric and Gas Company (Public Service Enterprise Group Incorporated)
• Original Assignee: Public Service Electric and Gas Company (Public Service Enterprise Group Incorporated)
• Inventors: Wang, Xiaodong, Roman, Harry, Farmer, Kenneth, Li, Baoqing
• Granted Patent: US 7,071,701 B2
• Time in Patent Office: Days
• US Class Current: 324/536
• CPC Class Codes: G01R 31/1209 using acoustic measurements acoustic measurements G01H3/00
• CPC Class Codes: G01R 31/1272 of cable, line or wire insulation, e.g. using partial discharge measurements locating faults in cables G01R31/083

Abstract

An approved method and apparatus for detecting partial discharge events within a transformer comprises asserting a MEMS acoustical probe through the wall of the transformer to optically measure partial discharge events. In an enhanced embodiment, temperature compensation is also possible, and detection may be confirmed via an independent electromagnetic or other sensor.

Claims

1. Apparatus for detecting events comprising a MEMS sensor and operationally coupled to transmission medium transmitting a signal from said sensor to a processor, said processor being configured to compare said signal to a stored signature in order to ascertain whether an event having a predetermined signature has occurred, said sensor being at least partially submerged in fluid.

2. Apparatus of claim 1 wherein said MEMS sensor is mounted in a probe.

3. Apparatus of claim 2 wherein said MEMS sensor is mounted within a lipped cavity.

4. Apparatus of claim 3 wherein said lipped cavity includes at least one opening in a bottom wall thereof for inserting a transmission medium.

5. Apparatus of claim 4 wherein said transmission medium is an optical fiber.

6. Apparatus of claim 4 wherein said lipped cavity includes at least two openings.

7. Apparatus of claim 6 further including pressure apparatus for injecting additional pressure into said lipped cavity to counter static pressure encountered in an operating environment against said MEMS sensor.

8. Apparatus for detecting partial discharge events in comprising a detection circuit for detecting acoustical signatures resulting from a partial discharge event, a plurality of stored signatures for comparing said acoustical signatures to said stored signatures, and an output for signaling detection of a partial discharge event when said detected acoustical signature matches at least one stored signature.

9. Apparatus of claim 8 wherein said at least one stored signature is selected for comparison to said detected signature based upon temperature of an environment in which said apparatus is operating.

10. Apparatus of claim 8 or 9 further comprising a temperature sensor.

11. Apparatus of claim 10 further comprising plural detection circuits for detecting said event, and a processor for trigonometrically locating said event.

12. The apparatus of claim 10 wherein said temperature sensor is integrated with said detection circuit.

13. The apparatus of claim 9 further comprising an electromagnetic sensor for detecting partial discharge events, and a processor for comparing signals detected at said electromagnetic sensor to signals detected at said detection circuit.

14. The apparatus of claim 11 wherein said detection circuit is an optical detection circuit.

15. The apparatus of claim 8 wherein plural detection circuits are integrated into a single probe.

16. The apparatus of claim 15 wherein said plural detection circuits comprise at least one circuit for detecting electromagnetic energy and at least one circuit for detecting acoustic energy.

17. The apparatus of claim 16 further comprising at least one temperature sensor.

18. Apparatus comprising a lip edged cavity including lips, said apparatus including at least two openings below said lips, at least a first of said openings being of sufficient size to insert a transmission medium.

19. The apparatus of claim 18 wherein an optical fiber is inserted through said first opening.

20. The apparatus of claim 19 wherein additional pressure is introduced through said second opening.