EP3803931B1 - Gas-insulated switch - Google Patents

Description

The invention relates to a gas-insulated switch according to claim 1 and a high-voltage switching arrangement according to claim 9.

In the area of high and medium voltage switchgear, sulfur hexafluoride SF ₆ is currently used as an insulating gas and as an extinguishing gas. This gas is excellent for the applications mentioned, but it has the disadvantage that it has a very high global warming potential. As an alternative to this, various compounds, in particular fluorinated compounds, are currently being discussed as insulating media. On the other hand, it is also useful to integrate vacuum interrupters in circuit breakers. With an increasing rated voltage, however, the technical effort required for the provision of vacuum interrupters in order to ensure sufficient dielectric strength of the switching gap after the current interruption increases disproportionately. In order to reduce this effort, it would be expedient to provide a circuit breaker, in particular designed in the form of a gas-insulated switch, which can be opened under electrical load, ie in particular in the event of a short circuit, and dielectrically relieves the vacuum interrupter. Gas-insulated switches are e.g. B. from the EP 1 079 404 A2 known.

The object of the invention is to provide a circuit breaker in the form of a gas-insulated switch which, compared to conventional gas-insulated switches, has a higher opening speed of the contacts in the event of a short circuit. Furthermore, the object is to provide a high-voltage switching arrangement with a vacuum interrupter which, compared to the prior art, can carry a higher voltage per installation space.

The solution to the problem consists in a gas-insulated switch according to patent claim 1 and in a high-voltage switch arrangement according to patent claim 9.

The gas-insulated switch according to claim 1 has a first contact and a second contact, each of which is part of a contact unit. At least one contact unit is connected to the first contact as a moving contact unit with a drive unit. The moving contact unit is movably mounted along a switching axis. The gas-insulated switch also includes a multi-part insulating material nozzle system that has a main nozzle and an auxiliary nozzle, with a heating channel being formed between the main nozzle and the auxiliary nozzle, which starts from an arc chamber and opens into a gas reservoir. This gas reservoir is limited on one side by a stamp. The invention is characterized in that the gas reservoir is at least partially delimited radially with respect to the switching axis by a wall, with the moving contact unit being mounted so that it can move along the switching axis with respect to this wall, and that the plunger is part of the moving contact unit and, together with this, in the manner of is movably mounted with respect to the second contact, that the plunger moves away from the second contact during an opening process of the two contact units to enlarge the gas reservoir along the switching axis.

In terms of structure, the gas-insulated switch of the invention is similar to a so-called self-inflating switch, but it differs in that the conventional self-inflating switch has a self-inflating volume, the volume of which is reduced by a stamp when the two contact systems are opened so that an extinguishing gas can flow back through the heating channel into is pressed into the arc space, thereby extinguishing the arc. However, in this conventional prior art self-inflating switch, the wall radially delimiting the self-inflating volume is part of the moving contact system and remains within the self-inflating volume when the switch is opened or the gas reservoir is motionless. In the present invention, the wall is movably mounted with respect to the first contact unit and is therefore not part of this first contact unit. In the present invention, the gas reservoir, which increases in size during the opening process, moves along the described wall of the reservoir.

It should also be noted that the insulating material nozzle system represents a functionally interacting system in which the individual components can each be part of the contact units. This means that the components such as the main nozzle and the auxiliary nozzle do not have to be rigidly arranged in relation to one another, but can move towards and away from one another during the opening and closing processes.

Due to the movable mounting of the contact of the moving contact unit, usually a tulip contact, and the auxiliary nozzle arranged around it in the switching chamber, the invention enables the gas reservoir to be enlarged in contrast to the self-blast circuit breakers used today, which in the present invention does not serve as a self-blast volume. Rather, the hot gas flowing through the heating channel exerts a force on the plunger, which causes an acceleration of the moving contact system in the pulling direction of the drive and thus supports the drive movement or increases the drive speed. This makes it possible to increase the contact opening speed with the same drive energy or to reduce the drive energy with a constant contact opening speed.

In a further embodiment of the invention, the wall at least partially delimiting the gas reservoir is a component of the contact unit of the second contact. This means that parts of the second contact system, i.e. at least the wall described, preferably radially surround parts of the first contact system and thereby contribute to the formation of a cavity, namely the gas reservoir, which, when the switch is opened, caused by the inflowing hot gas, is enlarged. The wall mentioned is expediently fastened to the second contact system so that it can be implemented with little structural effort. In principle, fastening the wall to the housing of the vacuum interrupter can also be expedient.

In a further embodiment of the invention, the plunger is arranged in the first contact system in such a way that it is essentially vertical with respect to a switching axis. Essentially means that an angular position in relation to the indexing axis is no more than 15°.

The plunger is designed to be rotationally symmetrical with respect to the switching axis. This leads to a rotationally symmetrical, essentially cylinder-wall-shaped gas reservoir around the switching contact. In an advantageous embodiment, the plunger is attached to a holder of the auxiliary nozzle and is thus permanently connected to the moving contact system.

In a gas-insulated switch based on the structure of the self-blowing principle, the two contacts have different shapes. There is a tulip contact, which is preferably the first contact, and a pin contact, which is preferably designed as the second contact. The pin contact is preferably part of a fixed contact unit. The tulip contact is preferably part of the moving contact unit, it also being possible in principle for both contact units to be designed to be movable via a corresponding coupled drive.

In a further embodiment of the invention, the described wall of the gas reservoir is part of the main nozzle. This would enable a cost-effective structural implementation.

A further embodiment of the invention is a high-voltage switching arrangement according to patent claim 9, which comprises a gas-insulated switch according to one of claims 1 to 8 and a vacuum interrupter. The gas-insulated switch and the vacuum interrupter, which in turn can be part of a circuit breaker, are connected in series. Because the described gas-insulated switch can be switched under load, the vacuum interrupter connected in series or in series manages with a lower electrical strength with regard to the rated voltage. This requires less technical effort in the construction of the vacuum interrupter and, in principle, higher rated voltages can be achieved with a given design.

It can be expedient here for the gas-insulated switch and the vacuum interrupter or a circuit breaker in which the vacuum interrupter is integrated to be operated by a common drive. This enables a simple technical structure and, on the other hand, a reliable chronological sequence of the switching processes.

In a further embodiment of the invention, the high-voltage switching arrangement is designed in such a way that the voltage distribution across the gas-insulated switch and the vacuum interrupter is controlled by a control device. A control device can be, for example, a capacitor or a resistor or a coupling of a capacitor and a resistor.

Further embodiments and further features of the invention are explained in more detail with reference to the following drawings. Features in different configurations but with the same designation are provided with the same reference symbols. In principle, these are schematic configurations that are purely exemplary in nature and do not represent a restriction of the scope of protection.

Figur 1

einen Querschnitt durch einen gasisolierten Schalter mit einer Bewegkontakteinheit und einer Festkontakteinheit sowie mit einem Gasreservoir,

Figur 2

einen gasisolierten Schalter analog zu Figur 1 mit einem zusätzlichen Lichtbogenlöschvolumen,

Figur 3

einen gasisolierten Schalter analog zu Figur 1, mit einem Lichtbogenlöschvolumen in der Hauptisolierstoffdüse und

Figur 4

eine Reihenschaltung des beschriebenen gasisolierten Schalters mit einer Vakuumschaltröhre und parallel dazu geschalteten Steuereinrichtungen.

show:

figure 1

a cross section through a gas-insulated switch with a moving contact unit and a fixed contact unit and with a gas reservoir,

figure 2

a gas-insulated switch analogous to figure 1 with an additional arc extinguishing volume,

figure 3

a gas-insulated switch analogous to figure 1 , with an arc extinguishing volume in the main insulating material nozzle and

figure 4

a series connection of the gas-insulated switch described with a vacuum interrupter and control devices connected in parallel thereto.

In figure 1 a cross section through a gas-insulated switch is shown which has a first contact 4 which is designed in the form of a tulip contact 30 and which has a second contact 6 which is designed in the form of a pin contact 32 . Both contacts 30, 32 are each integrated into a contact unit 8, 9, a first contact unit 8 and a second contact unit 9. The two contacts 30 and 32 can be moved in translation along a switching axis 10 during an opening or closing process of the gas-insulated switch 2 stored to each other. In this case, the pin contact 32 is generally but not necessarily designed as a fixed contact, while the tulip contact 30 is designed as a moving contact. Thus, the first contact unit 8 with the tulip contact 30 can also be referred to as a moving contact unit.

Furthermore, the gas-insulated switch 2 has an insulating material nozzle system 12 which, in particular, comprises a main nozzle 14 and an auxiliary nozzle 16 as well as a heating duct 18 formed thereby. The heating channel 18 leads from an arcing space 20 to a gas reservoir 22. The arcing space 20 is the space which forms when the contacts 30, 32 open and in which a switching arc 21 occurs during the opening process.

The gas reservoir 22 is delimited on the one hand on a radial inner side in this embodiment by the auxiliary nozzle 16 and on the other hand delimited radially outwards from the switching axis 10 by a wall 26 . These two delimitations by the auxiliary nozzle 16 and the wall 26 extend radially around the circumference, but parallel to the switching axis 10. A stamp 24 is also provided, which delimits the gas reservoir 22 axially. This means that the plunger 24 is essentially perpendicular but rotationally symmetrical to the switching axis 10 and the plunger 24 is movably mounted at least with respect to the wall 26 . This means that the plunger 24 is an integral part of the moving contact unit 8, whereas the wall 26 is not part of this moving contact unit 8. In a preferred embodiment, as shown in figure 1 is shown, be part of the second contact unit 9, it can be designed as an extension of the main insulating material nozzle 14. However, the wall 26 can also be mechanically decoupled from the fixed contact unit 9 and can be arranged, for example, on the housing (not shown) of the switch 2 .

During an opening movement of the switch 2, the tulip contact 30 and the pin contact 32 move apart along the switching axis 10, driven by a drive device that is not shown here. When the contacts 30, 32 open, a switching arc 21 occurs. The switching arc 21 heats the insulating medium present in the arc chamber, which is essentially gaseous, and is pressed into the gas reservoir 22 via the heating duct 18. The movement of the gas along the heating channel 18 takes place in particular as a result of the temperature increase and the resulting volume expansion. This volume expansion in turn leads to the insulating medium 23 being pressed against the plunger 24 with such high energy that the translational movement of the first contact unit 8, which is im Essentially includes the tulip contact 30, the auxiliary nozzle 16 and the plunger 24, so quickly that the speed of the movement caused by the drive is exceeded. This is therefore an additional acceleration of the moving contact unit 8 away from the fixed contact 32 . As a result, the gas reservoir 22 is enlarged and the plunger 24 moves in the direction of the arrow 25.

In the described opening mechanism of the switch 2, the energy of the arc 21 is thus utilized in order to accelerate the opening of the switch 2 and thus also to increase the separation distance between the two contacts 30, 32. In this way, the arc 21 is also extinguished. This can be relevant in particular if the switch 2 is connected in series with a vacuum interrupter 48, as is the case in figure 4 is shown. This series connection will be discussed further below.

At the in figure 1 The arrangement described dispenses with a self-blowing volume, known as a self-blowing switch, for extinguishing the switching arc 21 . The entire arc energy is thus used to accelerate the opening of the contact units 8, 9. However, it can also be expedient for the energy present from the arc to be split up and used on the one hand for accelerated opening of the switch 2 or the contact units 8 and 9 and another part of the arc energy to be directed into an arc-extinguishing volume 34 analogous to the self-blasting switch, with here, also analogously to the known self-inflating switch, there is also a compression volume 38, which opens at a certain counter-pressure and increases the pressure in the arc-extinguishing volume 34, so that the heated insulating medium 23 flows back through a branched-off heating channel 18' into the arcing chamber 20 and the Switching arc 21 occurs. this is in figure 2 shown insofar as the device according to figure 1 yet a second radially aligned with respect to the shifting axis 10 Having wall 36, which is part of the second contact unit 9 and which in turn surrounds the gas reservoir 22 and the first contact unit 18 at least partially radially. In this embodiment, it is possible that on the one hand the speed of the opening movement is increased with the same drive energy and, in parallel, another part of the energy of the switching arc 21 is used for arc quenching.

In figure 3 is an alternative embodiment of the advantageous representation according to FIG figure 2 shown in which also referred to the switch 2 again figure 1 is used, but this is designed in such a way that the arc-extinguishing volume 34 is fitted in the main nozzle 14, with the flow guidance here being structurally guaranteed by a hot-gas duct 44 and a cold-gas duct 42, if necessary, and a corresponding arrangement of flow control elements 40. Furthermore, a compression volume 38 (not shown here) can also be provided, via which insulating medium 23 can be additionally pressed into the arc extinguishing volume 34 through a compression channel 46 .

In figure 4 a circuit breaker 52 is shown, which comprises a gas-insulated switch 2 and a vacuum interrupter 48 . Parts of the circuit breaker 52 are one or two control devices 50 which are connected in parallel to the respective switching units, the gas-insulated switch 2 and the vacuum interrupter 48 . The control device 50 is, for example, a series or parallel connection of a capacitor with a resistor or just a resistor. This arrangement means that, for example, a vacuum interrupter 48, which is designed for a rated voltage level of 145 kV or 245 kV, can be used in conjunction with the gas-insulated switch 2 that can be switched under load, also a disconnector, in rated levels that are several hundred kilovolts higher than the nominally provided voltage levels can. In this way the technical complexity for producing the vacuum interrupter 48 is significantly reduced, which leads to smaller installation spaces and lower production costs. An important prerequisite for achieving this is the described gas-insulated switch 2, which is based on the technology of a conventional self-blowout switch, but which is modified compared to this in such a way that it can be opened under load, especially in the event of a short circuit, and rapid dielectric resolidification takes place.

Reference List

2

gas insulated switch

4

first contact

6

second contact

8th

Contact unit first contact

9

Contact unit second contact

10

shift axis

12

insulating material nozzle system

14

main jet

16

auxiliary nozzle

18

heating channel

20

arc room

21

switching arc

22

gas reservoir

23

insulating medium

24

Rubber stamp

25

Movement direction stamp

26

Wall

28

bracket

30

tulip contact

32

pin contact

34

arc extinguishing volume

36

second wall

38

compression volume

40

flow control element

42

cold gas channel

44

hot gas channel

46

compression channel

48

vacuum interrupter

50

control device

52

circuit breaker

Claims (11)

1. Gas-insulated switch having

   - a first contact (4, 30) and a second contact (6, 32) which are each a constituent part of a contact unit (8, 9), wherein at least one contact unit (8) with the first contact (4), as a moving contact unit (8), is connected to a drive unit and is mounted movably along a switching axis (10), and

   - a multipartite insulating material nozzle system (12) which has a main nozzle (14) and an auxiliary nozzle (16), wherein a heating duct (18) which starts from an arc area (20) and opens in a gas reservoir (22) is formed between the main nozzle (14) and the auxiliary nozzle (16), wherein the gas reservoir (22) is delimited by a ram (24) on one side,

   wherein
   the ram (24) is part of the moving contact unit (8) and in this case is mounted movably together with the said moving contact unit with respect to the second contact in such a way, and wherein the ram (24) moves away from the second contact along the switching axis (10) during an opening process of the two contact units (8, 9) for increasing the size of the gas reservoir (22), characterized in that the gas reservoir (22) is at least partially delimited by a wall (26) radially with respect to the switching axis (10), wherein the moving contact unit (8) is mounted movably along the switching axis with respect to the said wall.
2. Gas-insulated switch according to Claim 1, characterized in that the wall (26) at least partially delimiting the gas reservoir (22) is a constituent part of the contact unit (9) of the second contact (6, 32).
3. Gas-insulated switch according to Claim 1 or 2, characterized in that the ram (24) is oriented substantially perpendicularly with respect to the switching axis (10).
4. Gas-insulated switch according to one of the preceding claims, characterized in that the ram (24) is of rotationally symmetrical design with respect to the switching axis (10).
5. Gas-insulated switch according to one of the preceding claims, characterized in that the ram (24) is attached to a mount (28) of the auxiliary nozzle (16).
6. Gas-insulated switch according to one of the preceding claims, characterized in that the first contact is a tulip contact (30) and the second contact is a pin contact (32).
7. Gas-insulated switch according to one of the preceding claims, characterized in that the pin contact is part of a fixed contact unit.
8. Gas-insulated switch according to one of the preceding claims, characterized in that the wall (26) is part of the main nozzle (14).
9. High-voltage switching arrangement comprising a gas-insulated switch according to one of Claims 1 to 8 and at least one vacuum interrupter (32), wherein the gas-insulated switch (2) and the vacuum interrupter (32) are connected in series.
10. High-voltage switching arrangement according to Claim 9, characterized in that the gas-insulated switch (2) and the vacuum interrupter (32) are operated by a common drive mechanism.
11. High-voltage switching arrangement according to Claims 9 and 10, characterized in that a control device is provided for splitting voltage between the gas-insulated switch (2) and the vacuum interrupter (32).

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