SELF-CONTAINED APPARATUS FOR INSPECTION OF ELECTRICCONDUCTORS

• US 20080087091A1
• Filed: 10/13/2006
• Published: 04/17/2008
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: University of Denver
• Original Assignee: University of Denver
• Inventors: Shoureshi, Rahmat A.
• Granted Patent: US 7,437,934 B2
• Time in Patent Office: Days
• US Class Current: 73/602
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/102 one emitter, one receiver
• CPC Class Codes: G01N 2291/2698 Other discrete objects, e.g. bricks
• CPC Class Codes: G01N 29/223 Supports, positioning or alignment in fixed situation mounting transducers per se G10K11/004
• CPC Class Codes: G01N 29/2412 using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]; investigating the presence of flaws using eddy currents G01N27/90, magnetostrictive transducers B06B1/08, measuring magnetostrictive properties G01R33/18
• CPC Class Codes: G01N 29/4481 Neural networks
• CPC Class Codes: G01R 15/142 Arrangements for simultaneous measurements of several parameters employing techniques covered by groups G01R15/14 - G01R15/26

Abstract

A self-contained apparatus for inspecting energized and de-energized conductors. The apparatus includes a housing, at least one transmitter contained within the housing for generating and impinging pulses onto an electrical conductor, such that the pulses travel through and are reflected by the electrical conductor, and at least one receiver contained within the housing for receiving reflected pulses from the electrical conductor. The apparatus further including a controller for determining a condition of the electrical conductor based on an evaluation of the reflected pulses, and at least one indicator for displaying the condition of the electrical conductor determined by the controller.

Claims

1. An apparatus for inspecting electrical conductors, comprising:

(a) a housing;

(b) at least one transmitter contained within the housing for generating and impinging pulses onto an electrical conductor, such that the pulses travel through and are reflected by the electrical conductor;

(c) at least one receiver contained within the housing for receiving reflected pulses from the electrical conductor;

(d) a controller for determining a condition of the electrical conductor based on an evaluation of the reflected pulses; and

(e) at least one indicator for displaying the condition of the electrical conductor determined by the controller.

2. The apparatus according to claim 1, wherein the housing includes an upper housing portion and a lower housing portion.

3. The apparatus according to claim 2, wherein the upper housing portion and lower housing portion are moveable relative to each other from an open position for receiving the electrical conductor to a closed position for inspecting the electrical conductor.

4. The apparatus according to claim 3, and further including a motor drive assembly for moving the upper housing portion and lower housing portion relative to each other from the open position to the closed position, the motor drive assembly including:

(a) a feedback controlled motor; and

(b) a gear drive.

5. The system according to claim 4, and further including a motor driver for controlling the motor drive assembly.

6. The apparatus according to claim 1, wherein the at least one transmitter and at least one receiver form an electromagnetic acoustic transducer system.

7. The apparatus according to claim 1, wherein the controller includes an on-board microprocessor for evaluating the condition of the electrical conductor.

8. The apparatus according to claim 7, wherein the microprocessor uses software selected from the group consisting of fuzzy logic, neural network, and adaptive resonant theory network to provide system operation, fault detection, and classification of the condition of the electrical conductor.

9. The apparatus according to claim 1, wherein the housing includes an attachment device for attaching a hot stick thereto to allow the apparatus to be positioned on energized electrical conductors.

10. The apparatus according to claim 1, wherein a bounding fork is connected to the housing to discharge any electrical charge that could damage the apparatus when placing the apparatus on an energized electrical conductor.

11. The apparatus according to claim 4, and further including screw guides operably connected to the gear drive and feedback controlled motor to allow the upper housing portion and lower housing portion to be moved from the open position to the closed position.

12. The apparatus according to claim 1, wherein the housing is curve-shaped to prevent corona and made of a material capable of withstanding at least 500 kV and at least 1000 amperes.

13. The apparatus according to claim 1, and further including a plurality of switches positioned on the housing for manually controlling the apparatus.

14. The apparatus according to claim 2, wherein the upper housing portion and lower housing portion each include a recess for receiving a transmitter/receiver cartridge therein.

15. The apparatus according to claim 14, wherein each of the transmitter/receiver cartridges is operably connected to the at least one transmitter and the at least one receiver.

16. The apparatus according to claim 14, wherein each of the transmitter/receiver cartridges is removable and can be interchanged with other transmitter/receiver cartridges for testing on various sized electrical conductors.

17. The apparatus according to claim 14, wherein each of the transmitter/receiver cartridges include both a transmitter coil and a receiver coil.

18. The apparatus according to claim 17, wherein the transmitter coil and receiver coil for each of the transmitter/receiver cartridges are connected in series.

19. The apparatus according to claim 1, wherein the at least one transmitter includes a pulse generator for creating electric pulses having a frequency between about 50 KHz and about 200 KHz.

20. The apparatus according to claim 1, wherein the at least one transmitter includes a high voltage generator for creating high voltage electric pulses.

21. The apparatus according to claim 1, wherein the at least one transmitter includes a clocks and power on reset generator for initiating the creation of pulses in response to actuation of a test switch positioned on the housing.

22. The apparatus according to claim 1, wherein the at least one receiver includes a signal amplifier for amplifying current induced by reflective displacement waves of the conductor.

23. The apparatus according to claim 1, wherein the at least one receiver includes a negative voltage generator to stabilize an output voltage and reduce noise.

24. A self-contained electromagnetic acoustic transducer system for inspecting energized and de-energized electrical conductors, comprising:

(a) a first transmitter/receiver cartridge releasably secured in a recess of an upper housing portion of a housing and a second transmitter/receiver cartridge releasably secured in a recess of a lower housing portion of the housing, the upper housing portion and lower housing portion being operably attached to each other for movement between an open position for receiving an electrical conductor between the first and second transmitter/receiver cartridges and a closed position where the electrical conductor is clamped between the first and second transmitter/receiver cartridges for testing;

(b) at least one transmitter operably connected to the first and second transmitter/receiver cartridges for generating and impinging pulses onto the electrical conductor, wherein the pulses travel through and are reflected by the electrical conductor;

(c) at least one receiver operably connected to the first and second transmitter/receiver cartridges for receiving reflected pulses from the electrical conductor;

(d) a controller for determining a condition of the electrical conductor based on an evaluation of the reflected pulses; and

(e) a plurality of indicators for displaying the condition of the electrical conductor determined by the controller.

25. The system according to claim 24, wherein the first and second transmitter/receiver cartridges are removable and can be interchanged with other transmitter/receiver cartridges for testing on various sized electrical conductors.

26. The system according to claim 24, wherein the first and second transmitter/receiver cartridges each include a transmitter coil and a receiver coil.

27. The system according to claim 26, wherein the transmitter coil and receiver coil for each of the first and second transmitter/receiver cartridges are connected in series and appear as a single transmitter coil or receiver coil to the system.

28. The system according to claim 24, wherein the at least one transmitter includes:

(a) a pulse generator for creating electric pulses having a frequency between about 50 KHz and about 200 KHz;

(b) a high voltage generator for creating high voltage electric pulses; and

(c) a clocks and power on reset generator for initiating the creation of pulses in response to actuation of a test switch.

29. The system according to claim 24, wherein the at least one receiver includes:

(a) a signal amplifier for amplifying current induced by reflective displacement waves of the conductor; and

(b) a negative voltage generator to stabilize an output voltage and reduce noise.

30. A method for inspecting an electrical conductor, comprising the steps of:

(a) providing an apparatus having;

(i) an upper housing portion movably connected to a lower housing portion;

(ii) at least one transmitter;

(iii) at least one receiver; and

(iv) at least one controller;

(b) placing the apparatus on an electrical conductor such that the electrical conductor is positioned between the upper housing portion and the lower housing portion;

(c) transmitting a signal through the electrical conductor using the at least one transmitter;

(d) capturing a reflection of the amplified signal with the at least one receiver;

(e) processing and filtering the reflection of the amplified signal in the controller; and

(f) providing an indication of a condition of the electrical conductor based on the processed and filtered reflection of the amplified signal.

31. The method according to claim 30, and further including the step of attaching a hot stick to an attachment device on the upper housing portion.

32. The method according to claim 30, and further including the step of positioning a first transmitter/receiver cartridge in a recess of the upper housing portion and a second transmitter/receiver cartridge in a recess of the lower housing portion, wherein the first and second transmitter/receiver cartridges are sized for the electrical conductor.

33. The method according to claim 30, and further including the step of moving the upper housing portion and lower housing portion to an open position for receiving the electrical conductor.

34. The method according to claim 30, and further including the step of moving the upper housing portion and lower housing portion to a closed position for clamping the electrical conductor between the first and second transmitter/receiver cartridges.

35. The method according to claim 30, wherein the step of processing and filtering the reflection of the amplified signal includes the steps of:

(a) obtaining ASCII coded frequency sweep data files;

(b) making data sets mean zeroed;

(c) applying a high order band-pass filter;

(d) overlapping data files on a time domain;

(e) extracting the maximum value from each band-pass filtered data and constructing one time domain data file,

(f) removing the initial data points and final data points;

(g) applying a running average filter; and

(h) re-sampling of data.