MONOLITHIC GLASS RING AND METHOD FOR OPTICAL CURRENT MEASUREMENTS

Abstract

A glass ring for current measurements includes a glass body, which can be disposed around an electrical conductor and has a light entry surface and a light exit surface. The glass ring allows light which enters the glass body through the light entry surface to circulate completely around the conductor in the glass body by reflection on external sides or outer faces of the glass body, the light exiting from the glass body on the light exit surface. The glass ring is formed of a monolithic glass body. A method for optical current measurement includes using a current flow in an electrical conductor to generate an electromagnetic field around the conductor, by which a polarization of a light beam in the glass ring around the conductor, in particular with a plane perpendicular to the longitudinal axis of the conductor, is changed as the light beam circulates around the conductor.

Claims

1-12. (canceled)

13. A glass ring for current measurements, the glass ring comprising: a monolithic glass body configured to be disposed around an electrical conductor, said glass body having a light entry surface, a light exit surface and external sides; said glass body configured to allow light entering said glass body through said light entry surface to completely circulate around the conductor in said glass body due to reflection at said external sides of said the glass body and to allow the light to exit said glass body at said light exit surface.

14. The glass ring according to claim 13, wherein said glass body includes at least one of: two mutually opposite sides each having exactly four corners, or a circular cylindrical through-opening.

15. The glass ring according to claim 14, wherein: said glass body includes first, second, third and fourth sides, and said two mutually opposite sides are fifth and sixth parallel planar sides, or said circular cylindrical through-opening extends through said two mutually opposite sides.

16. The glass ring according to claim 13, wherein said glass body is configured to substantially completely maintain a polarization of the light upon a circulation of light around the conductor without any flow of current.

17. The glass ring according to claim 15, wherein said light entry surface is said third side of said glass body, said third side includes two adjacent partial surfaces being tilted about an angle relative one another, and said third side includes a partial surface.

18. The glass ring according to claim 17, wherein said partial surface has a triangular shape.

19. The glass ring according to claim 17, wherein said glass body includes at least one of: a first planar partial surface of said second side being adjacent to said sixth side, or a trapezoidal partial surface disposed adjacent to said fifth side and formed of two surfaces being tilted relative to one another.

20. The glass ring according to claim 19, wherein: said second side is adjacent to said third side, said first planar partial surface has a trapezoidal shape, said trapezoidal partial surface is formed of two triangular surfaces, and said two surfaces being tilted relative to one another are a second and a third partial surface of said second side.

21. The glass ring according to claim 20, wherein said third partial surface of said second side is tilted about an angle relative to said second partial surface of said second side.

22. The glass ring according to claim 21, wherein said angle about which said third partial surface of said second side is tilted relative to said second partial surface of said second side is 2 degrees.

23. The glass ring according to claim 15, wherein said fourth side is constructed of two mutually adjacent partial surfaces being tilted relative to one another.

24. The glass ring according to claim 23, wherein said fourth side is adjacent to said second side, and each partial surface of said fourth side has a trapezoidal shape.

25. The glass ring according to claim 15, wherein said first side is constructed of two mutually adjacent partial surfaces being tilted relative to one another.

26. The glass ring according to claim 25, wherein said first side is adjacent to said third side, and each partial surface of said first side is trapezoidal.

27. The glass ring according to claim 13, wherein said glass body at least one of: includes a glass having a Verdet constant being greater or smaller than zero, or is formed of a glass having a Verdet constant being greater or smaller than zero.

28. A method for optically measuring currents, the method comprising: providing a glass ring according to claim 13; and using a flow of current in an electrical conductor to generate an electromagnetic field around the conductor, for changing a polarization of a light beam in the glass ring disposed around the conductor during a circulation of the light beam around the conductor.

29. The method according to claim 28, which further comprises orienting the glass ring in a plane perpendicular to a longitudinal axis of the conductor.

30. The method according to claim 28, which further comprises, during the circulation around the conductor, causing the light beam to travel through a monolithic glass body, and changing directions of the light beam by reflection at external sides of the glass body.

31. The method according to claim 30, which further comprises: providing the monolithic glass body with first, second, third and fourth sides; and carrying out the change in directions of the light beam by reflection at least one of: at a third partial surface of the second side being tilted about an angle of 2 degrees relative to a second partial surface of the second side, or at a tilted triangular partial surface of the third side.

32. The method according to claim 31, which further comprises: providing the monolithic glass body with fifth and sixth sides; and causing the light to at least one of: enter the glass body through the light entry surface and exit the glass body through the light exit surface, or enter the glass body through at least one of the third side or two adjacent partial surfaces tilted relative to one another, or exit the glass body through the sixth side.

33. The method according to claim 32, which further comprises causing the light to exit the glass body through the sixth side at an angle of substantially 90 degrees relative to the entering light.

Description

[0024] In the drawings,

[0025] FIG. 1 schematically shows an oblique view of an arrangement for optically measuring a current 3 in an electrical conductor 2 with the aid of a glass ring 1 according to the invention, and

[0026] FIG. 2 schematically illustrates the shape or geometry of the glass ring 1 of FIG. 1.

[0027] FIG. 1 schematically illustrates an oblique view of an arrangement for optically measuring a current 3, in particular in the range of up to a few hundred amperes, in an electrical conductor 2 with the aid of a glass ring 1 according to the invention. The electrical conductor 2, for example a copper conductor and/or cable, is for example cylindrical. A current 3 flows in the direction of the arrow in FIG. 1. A glass ring 1 is arranged around the conductor 2, circulates around the conductor 2 completely. The glass ring 1 is arranged with a plane, in particular a parallel upper and lower side according to FIG. 1, perpendicularly to the longitudinal axis of the cylindrical conductor 2. The glass ring 1, with its substantially rectangular base and top surface or in particular parallel upper and lower side, has centrally a circular cylindrical through-opening, through which the conductor 2 is guided.

[0028] The glass ring 2 has six sides, in particular a parallel upper and lower side and in addition four lateral sides according to FIG. 1, wherein the sides delimit the glass body, that is to say the glass material of the glass ring 2, with respect to the outside, that is to say in particular with respect to the ambient air or the ambient gas. The glass or glass material of the glass ring 1 is for example a glass for optical applications, having a little contamination and a Verdet constant that is in particular greater than zero. The glass is high-temperature-resistant, for example.

[0029] Light or a light beam 4, in particular light having a specific optical wavelength that is adapted to the glass material and to its refractive index and absorption behavior, which light beam is provided for example via a laser or via a light source with optical components such as lenses, enters the glass ring 1 for example via a lateral side. The light is radiated into the glass ring 1 for example perpendicularly to the longitudinal axis of the conductor 2 or parallel to the parallel upper and lower side of the glass ring 1. The midpoint or the central axis of the light beam is here directed at a region of the light entry side that is adjacent to a corner of the glass ring 1, for example the front bottom right corner in FIG. 1. After reflections at sides or side surfaces of the glass ring 1, wherein the light beam in the glass ring 1 completely circulates once around the conductor 2, the light beam or the light exits at the light exit side, which is the lower side of the glass ring 1 in FIG. 1.

[0030] The region in which the light exits the glass ring 1 in the exemplary embodiment of FIG. 1 lies on the lower side that is adjacent to the corner of the glass ring 1 and adjacent to which the light enters at the light entry side. The light entry side and the light exit side are adjacent to one another, at an angle of substantially 90 degrees with respect to one another, wherein the light exit side is a lower side of the glass ring according to FIG. 1 and the light entry side is a lateral side. During the circulation of the light around the current-carrying conductor 2, the light changes its polarization substantially only in dependence on the electromagnetic field of the current 3 in the conductor 2. After calibration, a measurement of the polarization change of the light yields the current strength in the conductor 2 for example in amperes.

[0031] FIG. 2 illustrates the geometry of the glass ring 1 of FIG. 1 with its external delimiting sides in detail. Edges visible when viewed from the viewing angle of FIG. 2, are marked with solid lines, whereas edges that are obscured when viewed from the viewing angle of FIG. 2 are marked with dashed lines. The upper side or the upper delimiting surface of the glass ring 1 according to FIG. 2 is referred to as the fifth side 10. The lower side or the lower delimiting surface of the glass ring 1 according to FIG. 2 is referred to as the sixth side 11. The fifth and sixth sides 10, 11 are arranged parallel to one another and are planar. The two sides 10 and 11 are penetrated centrally by the circular cylindrical through-opening, that is to say they have circular holes, through which the conductor 2 is guided, which is not illustrated in FIG. 2 for the sake of simplicity.

[0032] Laterally of the glass ring 1, four sides, the first side 6, the second side 7, the third side 8, and the fourth side 9, terminate the glass ring 1, wherein in each case two sides 6 and 7 and also 8 and 9 lie opposite one another. The third side 8 is the light entry side. The third side 8 has two partial surfaces, wherein the first partial surface 8′ of the third side 8 has the shape of a triangle. One edge of the triangle is a common edge with the sixth side 11, and a further edge is a common edge with the second side 7. By dividing the third side 8 into two partial surfaces, for example produced from one surface by grinding, light can be coupled into the glass ring 1 on the third side 8 with sufficient intensity and be coupled out on the sixth side 11. The two partial surfaces of the third side 8 are connected to one another via a common, in particular straight, edge and enclose an obtuse angle.

[0033] The fourth side 9, which is constructed from two in particular trapezoidal partial surfaces, is located opposite the third side 8. The two partial surfaces of the fourth side are connected to one another by a common, in particular straight, edge and enclose an obtuse angle. One partial surface, the partial surface that is the upper partial surface in FIG. 2, forms a hip-roof-type construction with the second partial surface, the partial surface that is the lower partial surface in FIG. 2. The upper partial surface is arranged for example at a right angle with respect to the fifth side 10, and the lower partial surface is produced from the surface for example by oblique grinding.

[0034] The first side 6 is constructed similarly to the fourth side 9, except with partial surfaces being arranged the other way round. The two partial surfaces of the first side are connected to one another by a common, in particular straight, edge and enclose an obtuse angle. A partial surface 6′, the partial surface that is the upper partial surface in FIG. 2, forms a hip-roof-type construction with the second partial surface 6″, the partial surface that is the lower partial surface in FIG. 2. The lower partial surface 6″ is arranged for example at a right angle with respect to the sixth side 11, and the upper partial surface 6′ is produced from the surface for example by oblique grinding.

[0035] The second side 7 is constructed similarly to the first side 6, except with a partial surface that is the upper partial surface in FIG. 2 and is subdivided further into two partial surfaces 7′ and 7″. The lower partial surface in FIG. 2 is arranged for example at a right angle with respect to the sixth side 11, and the upper partial surfaces 7′ and 7″ are produced from the surface by oblique grinding. The two upper partial surfaces 7′ and 7″ are in each case triangular and have a common edge. A repositioning of the light beam during circulation through the glass ring 1 takes place owing to the partial surface 7″, as a result of which the light beam, after reflection at the partial surface 6′, can exit the glass ring 1 in particular perpendicularly to the sixth side 11.

[0036] The light beam thus enters the glass ring 1 on the third side 8, adjacent to the front lower corner in FIG. 2, via both partial surfaces of the third side 8, is reflected to the first partial surface 6′ of the first side 6 at the partial surface of the fourth side 9 that is the lower partial surface in FIG. 2, the light beam is reflected here to the first partial surface 7′ of the second side 7, and reflected further to the partial surface of the fourth side 9 that is the lower partial surface in FIG. 2. From the partial surface of the fourth side 9 that is the lower partial surface in FIG. 2, the light beam is reflected to the first partial surface 8′ of the third side 8, and, from here, further to the second partial surface 7″ of the second side 7, wherein reflection to and then at the first partial surface 6′ of the first side 6 to the sixth side 11 results in the light beam exiting the glass ring 1 via the sixth side 11. In the process, the light beam has completely circulated around the conductor 2 once and has substantially maintained its polarization due to reflection at the glass sides. Changes in the polarization that have taken place are in particular due only to the electromagnetic field of the conductor 2 in the glass ring 1 during the flow of current 3 in the conductor 2. The value of the flow of current 3 can in this way be determined via measurements of the degree of the change in polarization.

[0037] The previously described exemplary embodiments can be combined with one another and/or can be combined with the prior art. For example, glasses with a positive or with a negative Verdet constant can be used for the glass ring 1. The glass ring 1 can be produced from a cuboid body, which is produced by a glass cut, by way of grinding. Alternatively or in addition, in particular beveled and/or tilted surfaces can be produced directly by glass cutting or by polishing. The through-opening in the glass ring 1 can be circular cylindrical or for example square, T-shaped, or double-T-shaped, for example depending on the shape of the conductor 2 in particular in the case of rail-type conductors 2. The glass of the glass ring 1 or the glass body can be made for example of a Corning glass or comprise other optical glasses. Apparatuses for generating light, in particular light having one wavelength, which are not illustrated in the figures for the sake of simplicity, can comprise lasers and/or lamps having lenses and/or polarization filters. Apparatuses for analyzing the light, in particular for light having one wavelength with a changed polarization, which are not illustrated either in the figures for the sake of simplicity, can comprise polarization filters, lenses and/or interferometers.

[0038] The glass ring 1 can be produced from a cube, which is produced in particular by glass cutting. The beveled partial surfaces, in particular ground or angled at angles of 135 degrees with respect to the respectively associated cube surface or by 45 degrees, for example the partial surfaces 6′, 7′ and the lower partial surface according to FIG. 2 of the fourth side 9, are producible for example by glass cutting and/or glass grinding. The partial surface 7″, which is angled in particular by 2 degrees with respect to the partial surface 7′, is producible for example by grinding and/or by polishing. The partial surface 8′ is likewise producible by cutting and/or grinding, wherein all surfaces can be polished to a finish. Further processing methods for the glass ring 1 can comprise drilling, milling, and/or laser processing, for example.

LIST OF REFERENCES

[0039] 1 Glass ring [0040] 2 Electrical conductor [0041] 3 Direction flow of current [0042] 4 Light entry surface [0043] 5 Light exit surface [0044] 6 First side, front delimiting surface [0045] 6′ First partial surface of the first side, upper front delimiting surface [0046] 6″ Second partial surface of the first side, lower front delimiting surface [0047] 7 Second side, rear delimiting surface [0048] 7′ Second partial surface of the second side, first upper rear delimiting surface [0049] 7″ Third partial surface of the second side, second upper rear delimiting surface [0050] 8 Third side, right lateral delimiting surface [0051] 8′ First partial surface of the third side, right lower lateral delimiting surface [0052] 9 Fourth side, left lateral delimiting surface [0053] 10 Fifth side, upper delimiting surface [0054] 11 Sixth side, lower delimiting surface