ARRANGEMENT HAVING A GAS-INSULATED SWITCHGEAR

Abstract

An arrangement includes a gas-insulated switchgear which is configured for filling with a first electrical insulation fluid. A surge arrester is provided to reduce the protection level of the gas-insulated switchgear such that the switchgear has insulation spacings of at most the same size as those of a switchgear insulated with a second electrical insulation fluid which has a higher dielectric strength than the first electrical insulation fluid.

Claims

1-21. (canceled)

22. An arrangement, comprising: a gas-insulated switchgear (21) configured to be filled with a first electrical insulation fluid (23); and a surge arrester (22) for reducing a protection level of said gas-insulated switchgear (21) to provide said gas-insulated switchgear (21) with insulation spacings (27) having a size being at most equal to a switchgear insulated with a second electrical insulation fluid having a higher electrical dielectric strength than the first electrical insulation fluid (23).

23. The arrangement according to claim 22, wherein the second electrical insulation fluid has at least a proportion of sulfur hexafluoride.

24. The arrangement according to claim 23, wherein the first electrical insulation fluid (23) is an air-based insulation gas.

25. The arrangement according to claim 24, wherein the air-based insulation gas (23) for said gas-insulated switchgear (21) has substantially 80% nitrogen and 20% oxygen, and said insulation spacings (27) of said gas-insulated switchgear (21) are configured for the air-based insulation gas (23).

26. The arrangement according to claim 22, wherein said gas-insulated switchgear (21) has a vacuum switching device.

27. The arrangement according to claim 22, wherein said surge arrester is configured for three-phase high voltage, and said surge arrester has a fluid-tight housing for accommodating an electrically insulating insulation fluid and three arrester columns (6, 7, 8) having metal oxide resistance elements (10).

28. The arrangement according to claim 27, wherein the insulation fluid for said surge arrester is an air-based insulation gas.

29. The arrangement according to claim 28, wherein the air-based insulation gas for said surge arrester has substantially 80% nitrogen and 20% oxygen, and said insulation spacings of said surge arrester are configured for the air-based insulation gas.

30. The arrangement according to claim 27, wherein said metal oxide resistance elements (10) have a diameter (12) of at least 90 mm.

31. The arrangement according to claim 30, wherein said diameter (12) of said metal oxide resistance elements (10) is measured transverse to a longitudinal axis (13) through one of said arrester columns (6, 7, 8, 9).

32. The arrangement according to claim 27, wherein said arrester columns (6, 7, 8, 9) are connected in a Neptune circuit.

33. The arrangement according to claim 32, wherein: a first three of said arrester columns (6, 7, 8) run in a first longitudinal section (3) of said surge arrester and a fourth arrester column (9) runs in a second longitudinal section (4) of said surge arrester in said Neptune circuit; and a contact device (5) electrically conductively connects said three arrester columns (6, 7, 8) to one another and to said fourth arrester column (9).

34. The arrangement according to claim 33, wherein said fourth arrester column (9) runs as a continuation of one of said first three arrester columns (6, 7, 8) in said second longitudinal section.

35. The arrangement according to claim 33, wherein said fourth arrester column (9) disposed in said second longitudinal section (4) runs centrally and axially parallel to said first three arrester columns (6, 7, 8) on a midpoint axis (13).

36. The arrangement according to claim 33, wherein said first and second longitudinal sections (3, 4) have substantially equal lengths.

37. The arrangement according to claim 33, wherein said contact device (5) is disposed between said first and second longitudinal sections (3, 4).

38. The arrangement according to claim 22, which further comprises a fluid-tight housing in which said gas-insulated switchgear (21) and said surge arrester (22) are both disposed.

39. The arrangement according to claim 22, wherein said gas-insulated switchgear has at least one input field (41-54), and said surge arrester is connected upstream of said at least one input field.

40. The arrangement according to claim 39, wherein said gas-insulated switchgear has at least one output field (41-54), and said surge arrester is connected downstream of said at least one output field.

41. The arrangement according to claim 40, wherein said gas-insulated switchgear has a plurality of busbars (21), and said surge arrester is assigned to one of said busbars.

42. The arrangement according to claim 41, which further comprises a coupling field (36) for connecting said busbars (21), said surge arrester being spatially disposed in said coupling field.

Description

[0049] For better explanation of the invention,

[0050] FIG. 1 schematically shows an exemplary embodiment of an arrangement according to the invention, and

[0051] FIG. 2 schematically shows an exemplary embodiment of a surge arrester, and

[0052] FIG. 3 schematically shows an exemplary embodiment of a circuit diagram of a GIS with surge arresters.

[0053] FIG. 1 shows an arrangement 20 having a gas-insulated switchgear 21 which is designed to be filled with an air-based electrical insulation gas 23. A surge arrester 22 is provided in order to reduce the protection level of the gas-insulated switchgear 21 in such a manner that the switchgear 21 has insulation spacings 27 of at most the same size in comparison with a switchgear insulated with sulfur hexafluoride. The surge arrester 22 is arranged in the immediate vicinity of the switchgear 21 and is connected to the latter via electrical connecting pieces 24, 25.

[0054] FIG. 2 shows a surge arrester according to the invention for a three-phase high-voltage application, wherein the fluid-tight housing for accommodating an air-based electrical insulation gas is not illustrated. Four arrester columns 6, 7, 8, 9 are connected in a Neptune circuit. The arrester columns 6, 7, 8, 9 have metal oxide resistance elements 10 having a diameter 12 of at least 90 mm. The diameter 12 is determined transverse to a longitudinal axis 13 through the arrester. A first housing cover 1 is provided on the high-voltage side and a second housing cover 2 is provided on the ground-voltage side. Each arrester column is respectively pressed together between two end fittings by means of tension rods 11 (end fittings not illustrated).

[0055] Three arrester columns 6, 7, 8 are each arranged at the same distance from one another in a first longitudinal section 3 on the high-voltage side, with the result that a triangular basic shape results in cross section. The first longitudinal section 3 ends with a contact means 5 which connects the three arrester columns 6, 7, 8 to one another and to the fourth arrester column 9 in an electrically conductive manner. A fourth arrester column 9 is arranged in a second longitudinal section 4 in such a manner that it runs centrally and axially parallel to the first three columns 6, 7, 8 on a midpoint axis or longitudinal axis 13. The contact means 5 is substantially in the form of a metal plate and is arranged between the first and second longitudinal sections.

[0056] The arrester is designed, in terms of its insulation spacings, for the air-based insulation gas with substantially 80% nitrogen and 20% oxygen.

[0057] FIG. 3 shows an exemplary embodiment of a circuit diagram of a GIS with surge arresters. A circuit diagram with a field division of a typical GIS is known from page 16 of the product brochure Gas-insulated switchgear type series 8DN8 up to 170 kV, 63 kA, 4000 A from Siemens AG, 2012, Order No. E50001-G620-A122-V1-4A00. In the exemplary embodiment according to the invention, this circuit diagram has been supplemented with surge arresters 34, 35, 37, 38, 39, 40. The gas-insulated switchgear has a length 31 of 15130 mm with a total of 14 input and output fields 41-54. The fields 41-54 are connected to two busbars 32, 33 and can be connected via a coupling field 36.

[0058] In this case, provision is made for individual or all input fields of the GIS to be protected with surge arresters so that overvoltages coming from the outside do not damage the GIS. In particular, owing to the risk caused by lightning overvoltages, it is necessary to connect arresters upstream at the input of an overhead line. Depending on the design of the installation, it could be necessary to also use arresters at cable inputs.

[0059] It is also useful to use surge arresters in some or all output fields because switching overvoltages, which can occur in vacuum switching technology in particular, are therefore controlled, for example. Damage to equipment connected downstream of the GIS is therefore avoided.

[0060] As clear from the above-mentioned brochure, a typical GIS nowadays already has a large space requirement. The installation of surge arresters is therefore particularly readily possible where the corresponding field of the GIS is not completely filled with other assemblies. For example, there is still generally a relatively large amount of space in the coupling field in order to accommodate, for example, the surge arresters 34, 35 and/or the surge arrester 37 without the footprint of the GIS having to be significantly increased.