Fluorinated ketones as high-voltage insulating medium

1. An electrical insulation medium, comprising at least one of the following compounds:

(a) a fluorinated ketone selected from a group of fluorinated ketones C4-C8 with the general formula R—C(0)-R′, wherein R and R′ are partially fluorinated or perfluorinated substituents, or

(b) a fluorinated ketone selected from a group of fluorinated ketones C5-C7, C9, C10, C11, C13, C14, C15.

2. The electrical insulation medium according to claim 1 , wherein the compound from the groups of fluorinated ketones is C13.

3. The electrical insulation medium according to claim 1 , wherein the compound from the groups of fluorinated ketones is C14.

4. The electrical insulation medium according to claim 1 , wherein the compound from the groups of fluorinated ketones is C15.

5. The electrical insulation medium according to claim 1 , wherein the compound from the groups of fluorinated ketones is C5.

6. The electrical insulation medium according to claim 1 , wherein the compound from the groups of fluorinated ketones is C7.

7. The electrical insulation medium according to claim 1 , wherein the compound from the groups of fluorinated ketones is selected from the group consisting of CF 3 C(O)CF(CF 3 ) 2 , CH 3 C(O)CF 2 CF 2 H, and CH 3 C(O)CF 2 CFHCF 3 .

8. The electrical insulation medium according to claim 1 , wherein the fluorinated ketone is alpha-branched to the carbonyl group.

9. The electrical insulation medium according to claim 1 , wherein the compound from the groups of fluorinated ketones comprises at least one constituent that contains one or more non-chain forming heteroatoms interrupting the main carbon chain in a perfluorinated part of the molecule.

10. The electrical insulation medium according to claim 9 , wherein the heteroatom is a nitrogen, oxygen or sulphur atom.

11. The electrical insulation medium according to claim 9 , wherein the compound is a perfluoroketone.

12. A filling medium for a switching device or a switchgear for medium, high or extremely high voltage, comprising an electrical insulation medium according to claim 1 .

13. The filling medium according to claim 12 , further comprising at least one further component not belonging to the groups of fluorinated ketones.

14. The filling medium according to claim 12 , wherein the filling medium consists of the electrical insulation medium.

15. A switching device for medium, high or extremely high voltage, wherein at least one voltaged component of the switching device is enclosed in an enclosure and the enclosure is filled with a filling medium according to claim 12 .

16. A switchgear for medium, high or extremely high voltage, wherein at least one voltaged component of the switchgear is enclosed in an enclosure and the enclosure is filled with a filling medium according to claim 12 .

17. The switchgear according to claim 16 , wherein the component comprises at least one of a busbar, a cable connector and a switch.

18. A switchgear for medium, high or extremely high voltage, wherein at least one switch is enclosed in a switching chamber, wherein at least two contact means of said switch are enclosed in an enclosure, wherein the switching chamber and the enclosure are filled with a filling medium according to claim 12 .

19. The switchgear according to claim 18 , wherein the filling media of the switching chamber and the enclosure have the same composition.

20. The switchgear according to claim 18 , wherein the filling media of the switching chamber and the enclosure have a different composition.

21. A switching device for medium, high or extremely high voltage, wherein at least one voltaged component of the switching device is enclosed in an enclosure and the enclosure is filled with a filling medium according to claim 12 , wherein the enclosure comprises a closure element that can be opened and again closed.

22. The switching device of claim 21 , wherein the closure element is a flap valve.

23. The switching device of claim 21 , wherein the flap valve has locking means and sealing means.

24. The switching device of claim 21 , wherein the closure element provides access to the parts of the switching device which are enclosed in the enclosure.

25. The switching device of claim 21 , wherein the closure element allows filling the filling medium into the enclosure and removing the filling medium from the enclosure.

26. A switching device for medium, high or extremely high voltage, wherein at least two contact means of the switching device are enclosed in an enclosure and the enclosure is filled with a filling medium according to claim 12 .

27. The switching device of claim 26 , wherein the at least two contact means are of different designs.

28. The switching device of claim 26 , wherein the at least two contact means are switching tubes that can be connected electrically via a switching contact.

29. The switching device of claim 26 , wherein the at least two contact means are two contact pieces that can be directly connected together electrically.

30. The switching device of claim 26 , wherein the switching device is a three-position switch with three contact means enclosed in the enclosure.

31. The switching device of claim 26 , wherein the switching device is a switchgear comprising at least two voltaged components which are electrically insulated with respect to each other.

32. The switching device of claim 31 , wherein the voltaged components include a busbar, a cable connector, or a switch.

33. The switching device of claim 31 , wherein the switchgear includes a plurality of separate enclosures, each being filled with a filling medium, wherein the filling medium comprises an electrical insulation medium comprising at least one compound from the group of fluorinated ketones.

34. The switching device of claim 33 , wherein the filling medium is the same for all enclosures.

35. The switching device of claim 33 , wherein the filling medium differs between enclosures.

36. The switching device according to claim 31 , wherein the switchgear is a block switchgear containing more than one switch.

37. The electrical insulation medium according to claim 10 , wherein the compound is a perfluoroketone.

38. The electrical insulation medium according to claim 1 , wherein the compound is disposed around at least one electrically conducting component.