Switchgear arrangement

Abstract

A switchgear includes an interrupter unit. The interrupter unit is provided with first and second switching contact pieces that are movable relative to one another. A switching-gas duct that runs through the interrupter unit originates at an arc gap in which an electric arc can burn. The duct connects the arc gap to the surroundings of the interrupter unit. At least some sections of the switching-gas duct are delimited by mutually encompassing elements similar to an annular duct. One of the elements is a first member which is braced at the end similar to a pipe joint and which has a free end that projects in the direction of the arc gap.

Claims

1. A switchgear arrangement, comprising: an interrupter unit having first and second switching contact pieces movably disposed relative to one another; an arcing gas channel issuing from an arc gap to be formed between said first and second switching contact pieces, passing through said interrupter unit and connecting said arc gap to a surrounding environment of said interrupter unit; mutually encompassing elements at least sectionally delimiting said arcing gas channel in a form of a ring channel, said elements including a first body having one end clamped as a pipe connection piece at a support distal from said arc gap and a free end projecting towards said arc gap, said first body having a lateral surface side formed with at least one cutout; a sheath encompassing said first body and spanning said free end of said first body, and said sheath covering said at least one cutout in the lateral surface side of said first body in a radial direction; and a housing surrounding said interrupter unit, wherein said sheath is supported on said housing and electrically insulated therefrom.

2. The switchgear arrangement according to claim 1, wherein said mutually encompassing elements include a second body clamped in at said sheath and projecting as a pipe connection piece with a free end in a direction of said first body.

3. The switchgear arrangement according to claim 2, wherein said free ends of said first and second bodies project towards one another and overlap one another.

4. The switchgear arrangement according to claim 2, wherein said second body bears one of said first and second contact pieces.

5. The switchgear arrangement according to claim 1, wherein said sheath is supported on said first body.

6. The switchgear arrangement according to claim 1, wherein said first body is supported on said housing and electrically insulated therefrom.

7. The switchgear arrangement according to claim 1, which comprises a post insulator mounted to said housing and supporting said sheath directly at said housing.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawing:

(2) The FIGURE shows a section through a switchgear arrangement comprising an interrupter unit.

DESCRIPTION OF THE INVENTION

(3) The switchgear arrangement has a housing 1. The housing 1 is in this case in the form of a hermetically sealable encapsulating housing which accommodates an interrupter unit 2 in its interior. The housing 1 is in this case configured as a cast metal housing which provides a fluid-tight wall. The interior of the housing 1 is filled with an electrically insulating fluid, for example an electrically insulating gas, such as sulfur hexafluoride or nitrogen. Preferably, the housing 1 should be formed as a pressure vessel, with the result that the fluid located in the interior can also be subjected to an elevated pressure. The housing 1 has a first connection piece 3 and a second connection piece 4. It is possible to introduce a first and a second current path section 5a, 5b, in each case electrically insulated and spaced apart from the housing 1, into the interior of the housing 1 through the connection pieces 3, 4. The current path sections 5a, 5b can be brought into electrical contact with one another via the interrupter unit 2 of the switchgear arrangement or a connection between the two current path sections 5a, 5b can be interrupted by means of the interrupter unit 2. The fluid-tight termination of the housing 1 with respect to the current path sections 5a, 5b is not illustrated in the FIGURE. For example, the connection pieces 3, 4 can be closed by means of electrically insulating assemblies (through which the current path sections 5a, 5b pass in each case), with the result that the interior of the housing 1 is hermetically sealed off. Outdoor bushings which enable integration of the switchgear arrangement, for example in an outdoor switchgear assembly, can be provided as electrically insulating assemblies, for example.

(4) Ground potential is applied to the housing 1, and the housing 1 is supported on a base via supporting feet. The interrupter unit 2 is arranged in the interior of the housing 1. The interrupter unit 2 extends along a longitudinal axis 6. The interrupter unit 2 has a first switching contact piece 7 and a second switching contact piece 8. The first switching contact piece 7 is in this case in the form of a bolt and is oriented substantially coaxially with respect to the longitudinal axis 6. The second switching contact piece 8 is in the form of a bush and is likewise arranged coaxially with respect to the longitudinal axis 6. The contact regions of the first and second switching contact pieces 7, 8 face one another, wherein the dimensions of the first and second switching contact pieces 7, 8 are selected such that, in the case of a relative movement of the two switching contact pieces 7, 8 along the longitudinal axis 6, the bolt-shaped first switching contact piece 7 can be introduced into the bush-shaped second switching contact piece 8.

(5) The two switching contact pieces 7, 8 are in the form of arcing contact pieces of the switchgear arrangement. Correspondingly, the first switching contact piece 7 is supplemented by a first rated current contact piece 9. The second switching contact piece 8 is supplemented by a second rated current contact piece 10. The first switching contact piece 7 and the first rated current contact piece 9 as well as the second switching contact piece 8 and the second rated current contact piece 10 are brought into galvanic contact with one another, so that mutually assigned contact pieces permanently conduct the same electrical potential. In this case, the rated current contact pieces 9, 10 are configured in the form of pipes and are aligned coaxially with respect to the longitudinal axis 6, wherein the switching contact pieces 7, 8 are encompassed on the outer lateral surface side by their respectively assigned rated current contact pieces 9, 10. In the case of a make operation, it is provided that first the switching contact pieces 7, 8 make contact with one another, whereupon the two rated current contact pieces 9, 10 then make contact with one another. During a break operation, first isolation of the rated current contact pieces 9, 10 is provided, whereupon in temporal succession, isolation of the switching contact pieces 7, 8 takes place. During a make operation, the switching contact pieces 7, 8 lead the rated current contact pieces 9, 10. In the case of a break operation, the switching contact pieces 7, 8 lag the two rated current contact pieces 9, 10. The switching contact pieces 7, 8 and the rated current contact pieces 9, 10 are each held spaced apart from the housing 1 with electrical insulation.

(6) The second rated current contact piece 10 is mounted movably in a sliding bush 11 along the longitudinal axis 6. The sliding bush 11 is electrically conductively connected to the second rated current contact piece 10. The sliding bush 11 is provided with a circular-cylindrical cross section and is arranged coaxially with respect to the longitudinal axis 6. On the outer lateral surface side, a first post insulator 12a is caused to stop against the sliding bush 11, which first post insulator holds the sliding bush 11 in electrically insulated fashion with respect to the housing 1 on the lateral surface side. The second rated current contact piece 10 and the second switching contact piece 8 are arranged with a rigid angle with respect to one another. Correspondingly, a movement of the second rated current contact piece 10 is accompanied by a movement of the second switching contact piece 8.

(7) In order to couple a movement into the interior of the housing 1 and to effect a relative movement between the two switching contact pieces 7, 8, a shaft 13 passes through a wall of the housing 1 in fluid-tight fashion. The shaft 13 is mounted rotatably, with the result that a drive movement can be transferred in fluid-tight fashion into the interior of the housing 1 via a drive device arranged on the outer side of the encapsulating housing 1. A pivot lever 14 is arranged on the inner wall side on the shaft 13. A rotary movement of the shaft 13 can be converted into a linear movement along the longitudinal axis 6 by means of a conrod 15 via the pivot lever 14. The conrod 15 is connected to the second rated current contact piece 10. It is thus possible for the second rated current contact piece 10 and the second switching contact piece 8 to be moved along the longitudinal axis 6, guided in the sliding bush 11. A contact region is arranged on the sliding bush 11 in order to make electrically conductive contact between the second current path section 5b, via the sliding bush 11, and the second rated current contact piece 10 or the second switching contact piece 8.

(8) In order to position the first rated current contact piece 9 and the first switching contact piece 7, a sheath 16 is provided. The sheath 16 has a bell-shaped structure, wherein the sheath bottom extends radially at its end remote from the second rated current contact piece 10 or the second switching contact piece 8. On the lateral surface side, a contact region is arranged on the sheath 16, into which contact region the first current path section 5a protrudes, with the result that electrical contact can be made with the sheath 16. The sheath 16 is thus part of a current path to be switched. The sheath 16 is substantially rotationally symmetrical, wherein the axis of rotation is arranged congruently with respect to the longitudinal axis 6.

(9) Furthermore, a further post insulator 12b is provided, which in this case is configured as a rotationally symmetrical hollow insulator and is arranged coaxially with respect to the longitudinal axis 6. A first body 17 is caused to stop against the second post insulator 12b, wherein the first body 17 is substantially rotationally symmetrical and is oriented coaxially with respect to the longitudinal axis 6. In turn, the sheath 16 is caused to stop against the first body 17. The sheath 16 encompasses the first body 17 on the outer lateral surface side. The sheath 16 can also be supported directly on the second post insulator 12a and the first body 17 can be supported on the sheath 16. It is also possible for both the sheath 16 and the first body 17 to be supported directly on the second post insulator 12a. The first body 17 is in this case in the form of a pipe connection piece, wherein the pipe connection piece is fastened at one end and, with its free end, protrudes in the direction of the arc gap, which is formed between the switching contact pieces 7, 8 or the rated current contact pieces 9, 10, freely into the interior of the sheath 16. The first body 17 is sealed at one end in the region of its clamped-in portion at the front end. In relation to the longitudinal axis 6, a second body 18 is supported on the sheath 16 at the opposite end from the connection of the sheath 16 to the first body 17. The sheath 16 encompasses the second body 18 on the outer lateral surface side, wherein the second body 18 is formed sectionally as pipe connection piece. The second body 18 or the pipe connection piece has an inflow opening of the arcing gas channel. In this case, the inflow opening is at least partially delimited by the rated current contact piece 9. The second body 18 is clamped in on the sheath 16, with the result that a pipe connection piece-like section is fixed. The pipe connection piece-like section of the second body 18 protrudes with one free end in the direction of the free end of the first body 17.

(10) The second body 18 acts as a mount for at least one contact piece. In this case, the first switching contact piece 7 and the second rated current contact piece 9 are supported on the second body 18. The second body 18 positions elastically deformable contact figures so as to form a contact region of the first rated current contact piece 9. Correspondingly, the second body 18 is part of a current path of the switchgear arrangement to be switched. The two bodies 17, 18 overlap one another with their ends protruding in each case freely from their clamped-in points of their pipe connection piece-like sections. In this case, it is provided that the second body 18 protrudes into the first body 17 and is encompassed by the first body 17 on the outer lateral surface side. The second body 18 encompasses an arcing gas channel, which continues from the arc gap and protrudes into the interior of the first body 17. A deflection of the arcing gas channel is provided in the region of overlap of the two bodies 17, 18, wherein the arcing gas channel has a section with a structure in the form of a ring channel between the two bodies 17, 18. Furthermore, a further section of the arcing gas channel is formed between the outer lateral surface of the second body 18 and the inner lateral surface of the sheath 16, which further section is in the form of a ring channel. As the profile of the arcing gas channel continues, a section of the arcing gas channel which likewise has a structure in the form of a ring channel is formed between the outer lateral surface of the first body 17 and the inner lateral surface of the sheath 16. In the region in which the first body 17 is fastened on the second post insulator 12b, an outlet opening of the arcing gas channel into the surrounding environment of the interrupter unit 2 is provided. The outlet opening of the arcing gas channel is preferably in the form of a circular ring and is preferably oriented coaxially with respect to the longitudinal axis 6. Instead of a structure in the form of a circular ring, one or more segments of a circular ring can also be used as outlet opening.

(11) The first body 17 has a plurality of cutouts 19 on the lateral surface side. The cutouts 19 are oriented substantially radially with respect to the longitudinal axis 6, with the result that a radial flow-away direction for arcing gas emerging through the cutouts 19 is defined. The cutouts 19 are each spanned on the outer lateral surface side by the sheath 16, with the result that arcing gas passing through the cutouts 19 hits against the sheath 16 and is swirled and deflected there.

(12) The second switching contact piece 8 is encompassed by an insulating nozzle 20 on the outer lateral surface side. The insulating nozzle 20 is in turn encompassed by the second rated current contact piece 10 on the outer lateral surface side. The insulating nozzle 20 has an insulating nozzle channel, into which the first switching contact piece 7 can be moved in order to be able to come into contact with the bush-shaped contact region of the second switching contact piece 8. In this case, it is provided that both the first and the second switching contact pieces 7, 8 are mounted in locationally variable fashion in order to effect a relative movement of the switching contact pieces 7, 8 relative to one another. In the case of the rated current contact pieces 9, 10, on the other hand, only a movable mounting of the second rated current contact piece 10 is provided, whereas the first rated current contact piece 9 is fixed in position on the sheath 16. In order to drive the first switching contact piece 7, a deflection gear mechanism 21 is provided, which is connected to the insulating nozzle 20 via a coupling rod 22. A movement of the second rated current contact piece 10 results in a movement of the coupling rod 22. A movement of the coupling rod 22 is transferred to the first switching contact piece 7 via a coupling gear mechanism 21. The coupling gear mechanism 21 reverses the sense of direction of the movement of the coupling rod 22. The first switching contact piece 7 moves with the reverse sense of direction to that of the second switching contact piece 8. By virtue of the use of an insulating nozzle 20, which is movable together with the second rated current contact piece 10 and the second switching contact piece 8, a movement can be transferred onto the first switching contact piece 7 in electrically insulated fashion. During a make operation, the second rated current contact piece 10 and the second switching contact piece 8 are moved in the direction of the first rated current contact piece 9 and the first switching contact piece 7, respectively. Via the insulating nozzle 20, the coupling rod 22 and the deflection gear mechanism 21, a movement with the opposite sense of direction is transferred to the first switching contact piece 7, with the result that an increase in the contact-making speed of the two switching contact pieces 7, 8 takes place. This ensures that the switching contact pieces 7, 8 touch one another temporally prior to the rated current contact pieces 9, 10, with the result that make arcs are preferably guided to the switching contact pieces 7, 8. During a break operation, a movement of the second rated current contact piece 10 and of the second switching contact piece 8 and the insulating nozzle 20 fastened thereto away from the first switching contact piece 7 and the first rated current contact piece 9 takes place. In the process, first an isolation of the two rated current contact pieces 9, 10 with respect to one another and temporally thereafter, isolation of the two switching contact pieces 7, 8 from one another take place. Correspondingly, commutation of a break current from the rated current contact pieces 9, 10 onto the switching contact pieces 7, 8 takes place. An arc which is possibly struck is guided between the switching contact pieces 7, 8. Owing to the configuration of the insulating nozzle 20, an arc is preferably kept within this insulating nozzle 20.

(13) Arcing gas occurring preferably flows away in the direction of the first switching contact piece 7. The arcing gas flows into the arcing gas channel, which is initially delimited by the second body 18. The arcing gas is directed in the direction of the longitudinal axis 6. Owing to an elevated pressure continuing to prevail in the arc gap, a backflow of arcing gas is prevented. The arcing gas then flows along the path of the arcing gas channel towards a closed end side of the first body 17 and is deflected and firstly directed radially outwards through the cutouts 19 in the first body 17. Secondly, however, it is also pressed through the region of overlap in the form of a ring channel between the first and second bodies 17, 18. From there, the arcing gas continues to flow through the section in the form of a ring channel, which section is formed between the outer lateral surface of the second body 18 and the inner lateral surface of the sheath 16 in order to flow from this region, with the reversal of the sense of direction, again through a section of the arcing gas channel which is in the form of a ring channel, which section is delimited between the outer lateral surface of the first body 17 and the inner lateral surface of the sheath 16. Ultimately, the arcing gas flows, after multiple changes in the sense of direction, out of the interrupter unit 2 and flows into the surrounding environment of the interrupter unit 2. There, the arcing gas can further be mixed with electrically insulating fluid located in the surrounding environment of the interrupter unit 2 and swirled therewith.