Current conduction element and system for insulation monitoring

• US 10,641,816 B2
• Filed: 02/13/2018
• Issued: 05/05/2020
• Est. Priority Date: 02/13/2017
• Status: Active Grant

• Current Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Original Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Inventors: Hahre, Karsten, Heyne, Raoul, Kiefer, Michael
• Primary Examiner(s): Pyo, Kevin K
• Assistant Examiner(s): Williams, Don J
• Application Number:
  US15/895,099
• Publication Number:
  US 20180231600A1
• Time in Patent Office: 812 Days
• CPC Class Codes: G01D 5/353 influencing the transmission properties of an optical fibre
• CPC Class Codes: G01D 5/35345 using Amplitude variations to detect the measured quantity
• CPC Class Codes: G01D 5/35374 Particular layout of the fiber
• CPC Class Codes: G01R 31/1218 using optical methods; using charged particle, e.g. electron, beams or X-rays
• CPC Class Codes: G01R 31/1272 of cable, line or wire insulation, e.g. using partial discharge measurements locating faults in cables G01R31/083
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/4421 Insulators with helical structure of optical fibre, e.g. fibres wound around insulators
• CPC Class Codes: H01B 7/02 Disposition of insulation
• CPC Class Codes: H01B 7/328 comprising violation sensing means

Abstract

A current conduction element includes an electrical conductor and an insulation of the electrical conductor. The insulation includes a light waveguiding unit. Furthermore, a system and method for insulation monitoring are described.

Claims

1. A current conduction element comprising:

an electrical conductor; and

an insulation of the electrical conductor, the insulation including an insulant sheath and a light waveguiding unit, wherein;

the light waveguiding unit includes at least one optically conductive film coaxially surrounding the electrical conductor at least along a longitudinal section of the electrical conductor;

the at least one optically conductive film is formed of a plurality of waveguides and forms a cylinder which is underneath the insulant sheath and arranged directly on and in contact with the electrical conductor to surround the electrical conductor;

a distance between each of the plurality of optical waveguides corresponds to a minimal detectable crack size of the insulant sheath; and

the distance between the plurality of optical waveguides corresponds to a maximum diameter of a breach configured to be closed by elastic deformation of the insulant sheath.

2. The current conduction element as claimed in claim 1, wherein the plurality of optical waveguides each include a reflective end.

3. The current conduction element as claimed in claim 1, wherein the electrical conductor comprises a first winding with the plurality of optical waveguides at least along the longitudinal section of the electrical conductor.

4. The current conduction element as claimed in claim 3, wherein the electrical conductor comprises a second winding with the plurality of optical waveguides, said second winding being crossed by the first winding, at least along the longitudinal section of the electrical conductor.

5. The current conduction element as claimed in claim 1, wherein the plurality of optical waveguides of the at least one optically conductive film are arranged parallel to one another.

6. The current conduction element as claimed in claim 1, wherein the plurality of optical waveguides of the at least one optically conductive film are arranged in a lattice, wherein light is reflectable within the at least one optically conductive film.

7. The current conduction element as claimed in claim 1, wherein the at least one optically conductive film comprises at least one evaluation unit or at least one measuring unit or at least one light source.

8. A system for insulation monitoring, comprising:

at least one current conduction element as claimed in claim 1,

a light source,

an input coupling unit for coupling light from the light source into the light waveguiding unit of the at least one current conduction element,

a measuring unit for measuring at least one emergence property of the light transported by the light waveguiding unit, and

an evaluation unit for evaluating the at least one measured emergence property of the light transported by the light waveguiding unit, wherein a defect of the insulation of the current conduction element is detected by a deviation of the at least one emergence property from a reference light intensity value.

9. The current conduction element as claimed in claim 1, wherein the at least one optically conductive film is a coating on the electrical conductor.

10. A method for insulation monitoring of a current conduction element including an electrical conductor and an insulation of the electrical conductor, the method comprising:

coupling light from a light source into a light waveguiding unit of the insulation, the insulation further including an insulant sheath, wherein;

the light waveguiding unit includes at least one optically conductive film coaxially surrounding the electrical conductor at least along a longitudinal section of the electrical conductor;

the at least one optically conductive film is formed of a plurality of waveguides and forms a cylinder which is underneath the insulant sheath and arranged directly on and in contact with the electrical conductor to surround the electrical conductor;

a distance between each of the plurality of optical waveguides corresponds to a minimal detectable crack size of the insulant sheath;

the distance between the plurality of optical waveguides corresponds to a maximum diameter of a breach configured to be closed by elastic deformation of the insulant sheath; and

a defect of the insulation of the current conduction element is detected by a deviation of the at least one emergence property from a reference light intensity value,

measuring at least one emergence property of the light upon emergence from the light waveguiding unit using a measuring device for measuring the light transported by the light waveguiding unit, and

evaulating the at least one emergence property using the evaluation unit, wherein a defect of the insulation of the current conduction element is detected by a deviation of the at least one emergence property from a reference value.

11. The method as claimed in claim 10, further comprising:

depositing the at least one optically conductive film as a coating on the electrical conductor.