Method and apparatus for monitoring integrity of wires or electrical cables

• US 7,068,042 B2
• Filed: 07/26/2005
• Issued: 06/27/2006
• Est. Priority Date: 01/31/2001
• Status: Expired due to Fees

• Current Assignee: CM Technologies Corporation
• Original Assignee: CM Technologies Corporation
• Inventors: Van Alstine, Rollin, Allan, Gregory
• Primary Examiner(s): Benson, Walter
• Application Number:
  US11/188,760
• Publication Number:
  US 20050270036A1
• Time in Patent Office: 336 Days
• Field of Search: 324/525, 324/533, 324/539
• US Class Current: 324/525
• CPC Class Codes: G01R 31/008 on air- or spacecraft, railway rolling stock or sea-going vessels
• CPC Class Codes: G01R 31/11 using pulse reflection methods
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72

Abstract

An apparatus for monitoring the integrity of a wire is provided, which includes a TDR instrument for generating a pulse waveform for transmission through the wire. The apparatus also includes a function generator for generating an electrical or non-electrical forcing waveform for transmission through the wire. The pulse waveform is transmitted through the wire in combination with the forcing waveform and a detector measures a change in dissipation factor values along the wire.

Claims

1. An apparatus for monitoring integrity of a wire, comprising:

a pulse generator for generating a pulse waveform for transmission through the wire;

a generator for generating a non-electrical forcing function for stimulating the wire, wherein the pulse waveform is transmitted through the wire in combination with the non-electrical forcing function; and

a detector adapted to measure the change in dissipation factor values along the wire.

2. An apparatus according to claim 1, further comprising a coupling circuit arranged between the pulse generator and the wire.

3. An apparatus according to claim 2, wherein the coupling circuit comprises a high pass filter to isolate the pulse generator from the forcing waveform.

4. An apparatus according to claim 1, wherein the generator is a heat generator and wherein the non-electrical forcing function is a thermal forcing function.

5. An apparatus according to claim 4, wherein the thermal forcing function is at a predetermined temperature accordance with a type of wire insulation material and/or a type of wire conductor material.

6. An apparatus according to claim 4, wherein the heat generator sweeps the thermal forcing function between a temperature range of T_min and T_max, where T_peak is greater than T_min and less than T_max.

7. An apparatus according to claim 1, wherein the generator is a vibration generator and wherein the non-electrical forcing function is a mechanical forcing function.

8. An apparatus according to claim 7, wherein the mechanical forcing function is at a predetermined vibration in accordance with a type of wire insulation material and/or a type of wire conductor material.

9. An apparatus according to claim 7, wherein the vibration generator sweeps the mechanical forcing function between a frequency range of ω

_min and ω

_max, where ω

_peak is greater than ω

_min and less than ω

_max.

10. An apparatus according to claim 1, further comprising a digital multimeter for measuring a voltage induced in the wire.

11. An apparatus according to claim 1, further comprising an impedance meter for measuring the dissipation factor values of the wire.

12. A method for monitoring integrity of a wire, comprising the steps of:

generating a pulse waveform for transmission through the wire;

generating a non-electrical forcing waveform for stimulating the wire;

transmitting the pulse waveform through the wire in combination with the non-electrical forcing waveform; and

measuring a change in dissipation factor values along the wire.

13. A method according to claim 12, wherein the non-electrical forcing function is a thermal forcing function.

14. A method according to claim 13, wherein the thermal forcing function is at a predetermined temperature in accordance with a type of wire insulation material and/or a type of wire conductor material.

15. A method according to claim 13, further comprising a step of sweeping the thermal forcing function between a temperature range of T_min and T_max, where T_peak is greater than T_min and less than T_max.

16. A method according to claim 12, wherein the non-electrical forcing function is a mechanical forcing function.

17. A method according to claim 16, wherein the mechanical forcing function is at a predetermined vibration frequency in accordance with a type of wire insulation material and/or a type of wire conductor material.

18. A method according to claim 16, further comprising a step of sweeping the mechanical forcing function between a frequency range of ω

_min and ω

_max, where ω

_peak is greater than ω

_min and less than ω

_max.

19. A method according to claim 12, further comprising the step of measuring a voltage induced in the wire.

20. A method according to claim 12, further comprising a step of isolating the pulse waveform from the non-electrical forcing waveform.