EP0872934B1 - Metal clad switchgear - Google Patents

Description

TECHNICAL AREA

The invention is based on a metal-encapsulated gas-insulated switchgear according to the preamble of claim 1.

STATE OF THE ART

A circuit breaker for a metal-encapsulated gas-insulated switchgear assembly is known from patent specification EP 0 382 323 B1, which has a connection part for the electrical connection on the side of an arcing chamber facing away from the drive. This connecting part is designed to be dielectrically favorable; it is connected in an electrically conductive manner to the active part of a bushing. The heads of the screws, which rigidly connect the connecting part to the active part of the bushing mentioned, are covered with a metallic shield, which acts as a dielectric shield. When assembling and disassembling the connecting part, this hood must always be installed or removed, which requires additional assembly effort.

SUMMARY OF THE INVENTION

The invention, as defined in claim 1, is based on the object of specifying a metal-encapsulated gas-insulated switchgear which can be produced with less assembly effort.

The metal-encapsulated gas-insulated switchgear assembly is provided with at least one active part which is mounted in a housing and extends along an axis and which has a contacting assembly on at least one side. The contacting assembly is electrically conductively connected to at least one connecting part provided with a shielding electrode. The shielding electrode is connected to a support element delimiting an intermediate space. The support element is connected on the side facing away from the shielding electrode to a fitting which has bores which extend from the intermediate space and are designed for receiving fastening screws. Advantageous embodiments of the invention are the subject of the dependent claims. The support element can be constructed from two support columns or with a U-profile. The fastening screws for the connection part are dielectrically shielded in the space between the support columns or between the legs of the U-profile, so that they can be easily and quickly assembled or disassembled.

The space between the support columns preferably extends in the direction of the axis, the space in the U-profile opens to the side facing away from the drive side, which advantageously facilitates access to the fastening screws from the front of the housing.

The connecting part can have a centrally arranged shielding electrode. The one facing the shielding electrode The side of the contacting assembly can be provided with gas drying agent introduced between a contact carrier and a cover. When the contact assembly is definitely retracted, this gas drying agent lies within a volume inside the shielding electrode, but access of the insulating gas to the gas drying agent is guaranteed with simple means. The gas drying agent is removed during revisions together with the active parts from the housing, in the exemplary embodiment this is a switch housing, and can be replaced very easily on this occasion.

These advantageously designed components can be used both in single-phase and in multi-phase encapsulated switchgear.

An exemplary embodiment of the invention and the advantages which can be achieved thereby are explained in more detail below with reference to the drawing, which only represents one possible embodiment.

BRIEF DESCRIPTION OF THE DRAWING

• Fig.1 einen schematisch dargestellten Schnitt durch einen Leistungsschalter für eine erfindungsgemässe metallgekapselte gasisolierte Schaltanlage,
• Fig.2 eine Draufsicht auf eine erste Ausführungsform eines Anschlussteils für die Kontaktierung des Leistungsschalters,
• Fig.2a den in der Fig.2 angegebenen Schnitt A-A durch das Anschlussteil,
• Fig.2b den in der Fig.2 angegebenen Teilschnitt B-B durch das Anschlussteil,
• Fig.3 einen Teilschnitt durch das Anschlussteil mit eingefahrenem Gegenkontakt, und
• Fig.4 einen Teilschnitt, ähnlich dem in Fig.2b gezeigten Teilschnitt, durch eine zweite Ausführungsform des Anschlussteils.

Show it:

• 1 shows a schematically illustrated section through a circuit breaker for a metal-encapsulated gas-insulated switchgear according to the invention,
• 2 shows a plan view of a first embodiment of a connecting part for contacting the circuit breaker,
• 2a shows the section AA indicated in FIG. 2 through the connecting part,
• 2b shows the partial section BB indicated in FIG. 2 through the connecting part,
• 3 shows a partial section through the connecting part with a retracted counter contact, and
• 4 shows a partial section, similar to the partial section shown in FIG. 2b, through a second embodiment of the connecting part.

Elements with the same effect are provided with the same reference symbols in all the figures. All elements not necessary for the immediate understanding of the invention are not shown.

WAYS OF CARRYING OUT THE INVENTION

FIG. 1 shows a section through a circuit breaker 1 for a metal-encapsulated gas-insulated switchgear. The circuit breaker 1 has an essentially cylindrical switch housing 2 made of a metal or a metal alloy. On the two end faces of the switch housing 2, two openings 3 and 4 of the same size and of the same design are provided, each of which is provided with a flange 5 and 6, the opening 3 being assigned to the flange 5 and the opening 4 being assigned to the flange 6. The opening 3 is closed with a cover 7 screwed onto the flange 5 in a pressure-tight manner, on the side facing away from the flange 5 a drive 8 is flanged pressure-tight. A closure cover 9 is fastened on the flange 6 and closes the opening 4 in a pressure-tight manner.

On the top of the switch housing 2, two further openings 10 and 11 are provided on both sides, through which the electrical connections are introduced into the circuit breaker 1. The drive-side opening 10 is provided with a flange 12, it is closed in a pressure-tight manner with a support insulator 13 designed as a partition insulator. The support insulator 13 has an electrically conductive cast fitting 14 in the center. With the flange 12 are further, not shown here, supported on the switch housing 2 parts of the metal-encapsulated gas-insulated switchgear. The opening 11 facing away from the drive 8 is provided with a flange 15, it is closed in a pressure-tight manner with a support insulator 16 designed as a partition insulator. The support insulator 16 has an electrically conductive cast fitting 17 in the center. With the flange 15 are further, not shown here, supported on the switch housing 2 parts of the metal-encapsulated gas-insulated switchgear.

The active parts 19 of the circuit breaker 1 extend along an axis 18, which here are composed, for example, of two quenching chambers 20 and 21 which are connected in series and are held together by an electrically conductive connecting piece 22. The axis 18 generally does not coincide with the longitudinal axis of the switch housing 2, but it runs parallel to this. On the drive side, the quenching chamber 20 is connected to the drive 8 by an actuating rod 23 made of an insulating material. The arcing chamber 21 is also connected to the drive 8 by an actuating unit, not shown. The movable operating rod 23 is inserted pressure-tight into the interior of the switch housing 2. Various solutions are known for the pressure-tight insertion of the actuating rod 23, so there is no need to go into the specific embodiment here. The actuating rod 23 can also be supported against the cover 7 by an additional support insulator. A wide variety of variants are also possible for the configuration of the flange connection of the drive 8 to the cover 7.

On the drive side, the quenching chamber 20 is connected to the pouring fitting 14 via an electrically conductive connector 24. An easily detachable contact is integrated into the connecting piece 24, which facilitates the extension of the active parts 19. The arcing chamber 21 is provided on the side facing away from the drive 8 with a contacting assembly 25 which is inserted into a connecting part 26. The connecting part 26 is made of a metal, preferably it is cast from an aluminum alloy, and it is connected to the casting fitting 17 of the post insulator 16 in an electrically conductive manner. The active parts 19 are held mechanically by the two support insulators 13 and 16. As a rule, however, the extinguishing chamber 20 is additionally supported on the drive side in an insulating manner, but this support is not shown here.

The switch housing 2 is filled with an insulating medium, preferably SF ₆ gas under pressure. On the switch housing 2, two feet 27 are attached for the Attachment of the circuit breaker 1 on a foundation, not shown in the figure.

FIG. 2 shows a plan view of a first embodiment of the connecting part 26, specifically from the drive side of the circuit breaker 1. The connecting part 26 has a dielectric, toroidal shielding electrode 28. A cylindrical opening 29 is provided in the center of the shielding electrode 28 and is arranged concentrically to the axis 18. The opening 29 is delimited in the radial direction by an intermediate wall 30, the side of which facing away from the opening 29 is designed as a cylindrical contact surface 31 which, as can be seen in FIG. 2a, is provided with a bevel 32. Between the intermediate wall 30 and an outer wall 33 of the shielding electrode 28, a volume 34 which is wide open on the drive side is provided.

On the surface of the shielding electrode 28 are formed two spaced apart, dielectrically favorable support columns 35, which are arranged symmetrically to a central axis 36. On the side of the support columns 35 facing away from the shielding electrode 28, a fitting 37 which connects them and is formed in a dielectric manner is formed on these support columns 35. The armature 37 has on the side facing away from the shielding electrode 28 in the center a centering pin 38 which fits into a corresponding recess in the pouring armature 17 of the post insulator 16. The fitting 37 is provided with four bores 39 which receive the fastening screws for the connection of the fitting 37 to the pouring fitting 17. The heads of the fastening screws are here arranged so that they lie in the space 40 between the support columns 35. The heads of the fastening screws are dielectrically shielded by the support columns 35, so that their edges cannot negatively influence the electrical field in the area of the fitting 37. FIG. 2b shows the partial section BB shown in FIG. 2 through the connecting part. This cross-section shows the cross section of a dielectric support 35 which has comparatively large, shielding radii 41 on both sides of the intermediate space 40. The space 40 opens in the axial direction, so that the heads of the fastening screws are very easily accessible through the opening 4 after the removal of the cover 9, so that these fastening screws can be loosened or assembled very quickly and easily.

The two support pillars 35 can also be replaced by a single U-profile 50, which is cast from a metal or a metal alloy and is designed to be dielectrically favorable, and which opens towards the side of the circuit breaker facing away from the drive. This second embodiment of the connecting part 26 also ensures that the screw heads are very effectively dielectrically shielded and that the heads of the fastening screws are very easily accessible through the opening 4, so that the fastening screws can be loosened or mounted very quickly and easily.

FIG. 3 shows a partial section through the connecting part 26 with the contacting assembly 25 retracted. The contacting assembly 25 comprises an axially extending housing 42 made of a metal or a metal alloy, which is electrically connected to the quenching chamber 21. The housing 42 has a radially inwardly leading wall 43 which is provided with radially extending ribs 44 on the side facing the connecting part 26. Connected to the wall 43 leading radially inwards is an essentially axially extending contact carrier 45 which surrounds the intermediate wall 30 of the shielding electrode 28. In the side of the contact carrier 45 facing the contact surface 31, a guide ring 46 made of a plastic is embedded, which rests on the contact surface 31. In the side of the contact carrier 45 facing the contact surface 31, a groove is also incorporated, into which a spiral contact 47 is inserted, which ensures the electrical contact between the contacting assembly 25 and the connecting part 26. When retracting, the spiral contact 47 first makes contact and immediately afterwards the guide ring 46 mechanically relieves the spiral contact 47. The bevel 32 facilitates the insertion of the contacting assembly 25 and serves to accommodate tolerances between the connecting part 26 and the contacting assembly 25. The spiral contact 47 could also be inserted into the contact surface 31, as could the guide ring 46.

Exhaust gases escape through the opening 29 in the two embodiments shown. It is conceivable that the offset of the contact carrier 45 provided here to protect the electrical contact area against these gases and erosion particles may not be sufficient. In this case, it is very easy to constructively move the contact area radially outward, so that the outer wall 33 of the shielding electrode 28 for contacting the appropriately redesigned contacting assembly 25 can be used. If the connecting part 26 is not used in the circuit breaker area, the opening 29 can easily be closed with a cover, but care must be taken to ensure that the cover has a dielectric design.

The outer contour of the housing 42 is continued by means of a cover 48 up to the front edge of the contact carrier 45. This cover 48, which is connected to the housing 42 and centered by the outer edge of the ribs 44, is made from a perforated material, for example from a perforated plate or from a plastic. A cavity between this cover 48, the contact carrier 45 and the ribs 44 is largely filled with a gas drying agent 49, which is packaged in a gas-permeable bag.

Between the outer wall 33 of the shielding electrode 28 and the wall 43 of the housing 42, a gap s remains open with respect to the gas-filled interior of the switch housing 2, which facilitates the access of the insulating gas into the radially arranged spaces between the ribs 44 and thus to the gas drying agent 49. The area around the gap s is designed such that it does not interfere with the dielectric. The contact carrier 45 can be provided with radially extending openings in order to improve the gas circulation through the gas drying agent 49.

FIG. 4 shows a partial section through a second embodiment of the connecting part 26, namely that instead of the two support columns 35, a U-profile 50 of favorable dielectric design is provided, which connects the armature 37 to the shielding electrode 28. This U profile 50 is arranged so that its space 40 opens in the opposite direction to the drive side. An arrow 51 in this FIG. 4 indicates the direction to the drive 8.

To explain the mode of operation, the figures are now considered in more detail. The two openings 3 and 4 of the switch housing 2 are designed so that the active parts 19 can be extended and removed from the switch housing 2 on both sides. If the operating aisle for dismantling the quenching chambers 21 and 20 is provided on the side facing away from the drive 8, then the quenching chambers 20 and 21 are extended to this side after the drive 8 has been removed and dismantled in sequence. The operating aisle is advantageously designed to be narrow, as a rule it is only a little wider than the length of the extinguishing chambers 20 and 21 required. In this case, however, the connecting part 26 must additionally be dismantled before the extinguishing chambers 20 and 21 are extended in order to clear the way for the extension.

Dismantling of the connecting part 26 is very easy from the opening 4, since no additional shielding of the fastening screws has to be carefully dismantled. The axially extending space 40 between the support columns 35, or between the legs of the U-profile 50, allows easy access in the axial direction from the opening 4 forth with tools for loosening the four fastening screws that connect the connector 26 with the pouring fitting 17 Connect post insulator 16. After loosening and removing the fastening screws, the connecting part 26 can simply be pulled off and removed from the contact carrier 45. The assembly of the connecting part 26 is also very easily possible, since no additional shielding for the fastening screws has to be attached and adjusted. The centering pin 38 facilitates the correct positioning of the connecting part 26 during assembly, so that it is not necessary to align the connecting part 26 in a complex manner. In order to simply ensure the correct axial alignment of the connecting part 26, an additional dowel pin can optionally be inserted into the surface of the fitting 37 facing the pouring fitting 17, which engages in a corresponding bore in the surface of the pouring fitting 17. The connector described effectively compensates for axial tolerances and thermal expansion.

It has a particularly advantageous effect that the volume 34 in the interior of the shielding electrode 28, which inevitably arises due to the dielectric shape of this shielding electrode 28, can be used here to accommodate the gas drying agent 49, so that no additional assemblies for the positioning of what is always necessary Gas drying agent 49 must be installed in the switch housing 2. Such additional assemblies are usually placed in bulges in the wall of the switch housing 2 in order to shield them dielectrically. Here these bulges can be omitted, which make the switch housing 2 more expensive and make it more difficult to clean. Furthermore, it has an advantageous effect that the gas drying agent 49 is removed together with the active parts 19 during revisions, so that it is then very easily accessible and can be exchanged very easily and simply outside the switch housing 2. The assembly effort is advantageously kept small.

The concept of this metal-encapsulated gas-insulated switchgear allows the operating aisle to be arranged either on the drive side of the switchgear or on the side facing away from the drive 8. This variable system concept allows the switchgear to be optimally adapted to the respective structural conditions and to the wishes of the customers. The connection part 26, which can be assembled and disassembled easily and quickly, enables this advantageous system concept without significantly increasing the assembly effort.

The principle of using the unused space inside the shielding electrodes 28 to accommodate the gas drying agent 49 can generally be used advantageously in metal-encapsulated gas-insulated switchgear if the free access of the SF ₆ gas to the gas drying agent 49 is ensured.

The connecting part 26 can also be used advantageously for inexpensive and space-saving angular connections at other points in the metal-encapsulated gas-insulated switchgear, for example for kinking busbars. The corresponding gas spaces of the switchgear can thus be provided with the gas drying agent without great effort.

In the exemplary embodiment, the installation of the connecting part 26 in a horizontally arranged housing is described, but in principle it is possible to provide the advantageously designed connecting part 26 with the contacting assembly 25 engaging in it, also in vertically arranged housings.

LIST OF DESIGNATIONS

1

Circuit breaker

2nd

Switch housing

3.4

opening

5.6

flange

7

cover

8th

drive

9

Sealing cover

10.11

opening

12th

flange

13

Post insulator

14

Sprue fitting

15

flange

16

Post insulator

17th

Sprue fitting

18th

axis

19th

Active parts

20.21

Arcing chamber

22

Connector

23

Operating rod

24th

Connector

25th

Contacting assembly

26

Connector

27

Feet

28

Shielding electrode

29

opening

30th

Partition

31

Contact area

32

bevel

33

Outer wall

34

volume

35

Support columns

36

Central axis

37

Fitting

38

Centering pin

39

Holes

40

Space

41

Radii

42

casing

43

wall

44

Ribs

45

Contact carrier

46

Guide ring

47

Spiral contact

48

cover

49

Gas drying agents

50

U profile

51

arrow

s

gap

Claims (10)

1. Metal-enclosed, gas-insulated switchgear assembly having at least one active part (19) which is mounted in an enclosure extended along an axis (18) and has a contact-making assembly (25) on at least one side, having at least one connecting part (26) which is provided with a screening electrode (28) and can be connected in an electrically conductive manner to the contact-making assembly (25), characterized

   - in that the shielding electrode (28) of the connecting part (26) is connected to a supporting element which bounds an intermediate area (40),

   - in that the supporting element is connected, on the side facing away from the shielding electrode (28), to a fitting (37), and

   - in that the fitting (37) has holes (39) which originate from the intermediate area (40) and are designed to hold fixing screws.
2. Switchgear assembly according to Claim 1, characterized

   - in that the holes (39) for holding the fixing screws are arranged in the dielectrically shielded region of the intermediate area (40).
3. Switchgear assembly according to Claim 2, characterized

   - in that the supporting element is formed from two separate supporting pillars (35).
4. Switchgear assembly according to Claim 3, characterized

   - in that the intermediate area (40) between the supporting pillars (35) extends in the direction of the axis (18).
5. Switchgear assembly according to Claim 2, characterized

   - in that the supporting element is formed from a U-section (50).
6. Switchgear assembly according to Claim 5, characterized

   - in that the intermediate area (40) between the limbs of the U-section (50) opens axially on the side opposite the drive (8).
7. Switchgear assembly according to one of Claims 1 to 6, characterized

   - in that the connecting part (26) is designed as an element which can be removed in one piece.
8. Switchgear assembly according to one of Claims 1 to 7, characterized

   - in that the shielding electrode (28), which is arranged concentrically with respect to the axis (18), has an annular volume (34) for holding the contact-making assembly (25), and

   - in that the shielding electrode (28) has a cylindrical intermediate wall (30) which extends in the direction of the contact-making assembly (25) and on which a contact support (45) of the retracted contact-making assembly (25) is supported.
9. Switchgear assembly according to Claim 8, characterized

   - in that the side of the contact-making assembly (25) which faces the shielding electrode (28) is provided with a gas drying means (49) which is introduced between the contact support (45) and a cover (48), and

   - in that this gas drying means (49) is located within the volume (34) of the shielding electrode (28) when the contact-making assembly (25) is definitively retracted.
10. Switchgear assembly according to Claim 9, characterized

    - in that a circumferential gap (s) is provided between the shielding electrode (28) and a further enclosure (42), and

    - in that a radially running wall (43) of the enclosure (42) is provided with ribs (44) which run radially and extend axially, such that the intermediate areas between the ribs (44) are open to the outside in the region of the gap (s).