EP4088298B1 - Electrical switching arrangement - Google Patents

Description

The present invention relates to an electrical switching arrangement, such as in particular an electrical isolating switching device. The present invention relates in particular to an isolating switching device which allows improved gas insulation of an isolating gap between two contact pieces.

Electrical isolating switching devices are widely known. They are usually used to isolate high currents. Such isolating switching devices usually comprise a first contact piece and a second contact piece, which are arranged to be movable relative to one another and can be separated from one another in a separation zone or can be arranged so that they make contact with one another.

It is also known to improve gas insulation by flushing the contact pieces with an insulating gas provided in a reservoir. Such flushing of the contact pieces can take place and/or be necessary in particular when the contact pieces are separated.

WO 2018/114204 A1 and EN 10 2016 226 034 A1 , for example, describe an electrical switching device having a first switching contact piece and a second switching contact piece, wherein the switching contact pieces are movable relative to one another and the first switching contact piece is surrounded by a fluid flow guide device, wherein the fluid flow guide device surrounds the first switching contact piece on the casing side in such a way that an envelope contour of a flow channel delimited between the fluid flow guide device and the first switching contact piece is larger, at least at its end facing the second switching contact piece, than the envelope contour of the first switching contact piece at its end facing the second switching contact piece.

EP 3 309 810 A1 and EN 10 2016 219 812 A1 describe a switching arrangement having a blowing device and a first switching contact with a first and a second switching contact piece. A switching path extends between the switching contact pieces at least temporarily. The blowing device serves both the first switching contact and a second switching contact.

EN 10 2013 205 945 A1 describes a disconnecting device with a first contact piece and a second contact piece, which are movable relative to one another and between which a separation zone is formed in the separated state, is equipped with a compression device with a compression space for receiving a fluid. The compression space projects at least temporarily into the separation zone.

The US$3,588,407 A circuit breaker with insulating nozzle can be removed, which describes the use of separate containers with compression chambers for three phases to be switched. The EP0433183A1 describes a three-phase circuit breaker that also has separate containers with compression spaces for the respective phases. The US$4,663,504 describes a multi-phase load switch with separate containers for each phase.

However, such solutions known from the prior art can still offer further potential for improvement, in particular with regard to at least one of a simple structure and a defined and reliable operation of an electrical isolating device.

It is the object of the present invention to at least partially overcome the disadvantages known from the prior art. It is in particular the object of the present invention to provide a solution by means of which an electrical switching arrangement with a simple structure and a defined and reliable operation can be provided at least in part.

The object is achieved according to the invention at least in part by an electrical switching device with the features of claim 1. The object is also achieved according to the invention at least in part by a gas-insulated switchgear with the features of claim 10. Preferred embodiments of the invention are described in the subclaims, in the description or in the figures, whereby further features described or shown in the subclaims or in the description or in the figures can individually or in any combination constitute an object of the invention, unless the context clearly indicates the opposite.

A switching arrangement according to claim 1 is described.

Such a design allows a simple construction with a defined blowing of a plurality of contact arrangements.

A switching arrangement with a plurality of at least two contact arrangements is provided to interrupt a switching path or to bridge a switching path. The switching arrangement can have at least a first contact arrangement and a second contact arrangement. Each of the Contact arrangements have a first and a second switching contact piece. A switching path can extend between the switching contact pieces of a switching contact, at least temporarily. The impedance of the switching path can be changed to switch the switching arrangement on or off. For this purpose, the switching path can be bridged mechanically, for example, or its impedance can be changed in some other way. For example, the switching path can also be bridged by means of an arc. In a simple case, a relative movement of the switching contact pieces of the respective switching contact can be provided to bridge the switching path. At least one of the switching contact pieces can be arranged to be movable, whereas the other switching contact piece of the respective contact arrangement can be arranged in a fixed position. However, it can also be provided that both the first and the second switching contact piece are designed to be movable or drivable, so that a movement is coupled to both the first switching contact piece and the second switching contact piece to trigger a switching process.

In any case, the first contact piece and the second contact piece are movable relative to each other in order to form an electrical connection when the first contact piece and the second contact piece are in contact with each other and to form an insulating distance when they are separated from each other.

The multiple contact arrangements can be arranged so that they are electrically insulated from one another. This makes it possible to switch different electrical potentials/currents in the switching contacts. Various types of devices can be used as the switching arrangement. For example, isolating switches and earthing switches can function as the switching arrangement. However, it can also be provided that load switches or circuit breakers serve as the switching arrangement.

It can advantageously be provided that the switching contact pieces of the respective contact arrangement are combined arc and main contacts. This makes it possible to construct the switching contact pieces in a simple structure. If necessary, sections of the contact pieces can be equipped with an erosion-resistant material. This makes it possible to form low-mass and low-impedance contact pieces. A contact piece can, for example, be designed in the shape of a socket or a bolt. A bolt-shaped contact piece can, for example, also be designed in a substantially tubular manner.

By using at least two contact arrangements, the switching arrangement is able to carry out a switching operation in a multi-phase system. By using several contact arrangements, the power to be transmitted can be increased.

The blowing arrangement makes it possible to blow a fluid flow into the switching path during a switching operation, i.e. while bridging a switching path and/or while establishing a switching path, and to remove any impurities in the switching path. The blowing arrangement can preferably drive a gaseous fluid. However, it can also be provided that the blowing arrangement drives a liquid fluid. Fluorine-containing fluids are particularly suitable for flowing through the contact sets. For example, fluoroketone or fluoronitrile can be used as fluids. However, natural fluids such as nitrogen, carbon dioxide, oxygen as a component of the insulating gas or synthetic air can also be used for blowing. Fluid mixtures which have at least one of these components can also be used. The blowing arrangement can be designed differently from the switching contact pieces, so that the performance of the blowing arrangement can be adjusted without having to intervene in the structure of a contact piece.

With regard to the blowing arrangement, it is provided that the blowing arrangement has at least two blowing volumes, wherein a first contact arrangement can be supplied with insulating gas by a first blowing volume and wherein a second contact arrangement can be supplied with insulating gas by a second blowing volume.

In other words, the switching arrangement described here proposes providing a plurality of blowing volumes which are adapted to the number of contact arrangements or to the number of phases in the circuit. Thus, as is known from the prior art, one blowing volume is not provided which supplies all contact arrangements with an insulating gas, but rather a plurality of blowing volumes are provided according to the number of contact arrangements.

This makes it possible to dispense with such blowing channels, in contrast to the provision of only one blowing volume which is connected to the contact arrangements by means of blowing channels. This can simplify the structure and thus make the production of the switching arrangement more cost-effective.

Furthermore, there are advantages compared to a blowing volume that supplies all contact arrangements directly and thus extends over all contact arrangements. This design can do without the channels due to its spatial extension and can directly achieve uniform blowing of all contact pieces. However, difficulties arise in the switching speed. Due to the necessary size of the design of the blowing volume, an unacceptably high negative pressure is created in the blowing system when switched on. This can be counteracted with a flap/valve mechanism. However, this in turn entails the provision of another arrangement, the flap/valve mechanism. Such a design also can be dispensed with in the sense of the present invention.

Thus, according to the invention, the structure and assembly of the switching arrangement can be simplified by reducing the number of components.

It also seems important to correctly dimension the blowing volume, which may be designed as a blowing piston. The size can advantageously be adapted precisely to the switching-off currents, but can also be as small as possible for switching-on. This is particularly the case if, as described above, special measures such as flow channels or flap mechanisms are undesirable. Such dimensioning of the blowing volumes is easily possible within the scope of the present invention, which can allow another significant advantage with regard to the structure and operation of the switching arrangement.

Therefore, the present invention can further prevent the switching speed from being influenced.

A switching arrangement according to the present invention is therefore aimed at multiplying a blowing system. This allows each contact arrangement to be supplied with insulating gas separately. At the same time, the blowing volume can be made relatively small, since with this concept the distances between the contact arrangements do not have to be bridged, for example by the spatial expansion of the blowing volume.

The present invention can be particularly advantageous if a number of more than two contact arrangements is provided. It can therefore be particularly advantageous if at least one third blowing volume and one third contact arrangement are additionally provided, wherein the third contact arrangement can be supplied with insulating gas through the third blowing volume.

It may also be preferred that the first contact arrangement can be supplied with insulating gas exclusively through the first blowing volume and that the second contact arrangement can be supplied with insulating gas exclusively through the second blowing volume and that, if applicable, i.e. if present, the third contact arrangement can be supplied with insulating gas exclusively through the third blowing volume. In other words, each contact arrangement is thus assigned a blowing volume, and a supply of insulating gas can be carried out exclusively through this blowing volume.

In this design, gas cannot pass from one blowing volume to another. This enables particularly defined blowing, as it is ensured that the volume of insulation gas is only flushed to the contact arrangement associated with the blowing volume, but not to another contact arrangement, which enables a defined flow of insulation fluid. In addition, a specific volume of insulation gas is always available for each of the contact arrangements, which can be fed directly to the contact arrangement. This can increase safety. Finally, this enables a particularly simple structure.

In addition, the respective blowing volume can be adapted exactly to the respective contact arrangement, for example with regard to the insulation gas or with regard to the volume, which allows particularly safe and effective operation. In particular, it can thus be provided that at least some of the existing blowing volumes contain different insulation gases or that the blowing volumes have at least some different sizes.

It may further be preferred that the blowing arrangement comprises a volume-displacing piston-cylinder arrangement, wherein at least one contact piece from the first contact arrangement and the second contact arrangement and the third contact arrangement are arranged fixedly on the piston-cylinder arrangement. Accordingly, it can be provided that a separate piston-cylinder arrangement is provided for each contact arrangement, which is designed to be gas-tight in particular with respect to the other piston-cylinder arrangements.

A volume-displacing piston-cylinder arrangement has the advantage that a pressure difference can be repeatedly generated in the piston-cylinder arrangement, so that a fluid flow can be generated in a simple manner. A pressure difference can be generated by a relative movement of a piston to a surrounding cylinder. The relative movement of a piston and a cylinder of the piston-cylinder arrangement can be synchronized with a switching process (e.g. a switching movement) of the contact arrangement, so that a differential pressure of a fluid is only generated in the piston-cylinder arrangement when required. This prevents fluid under excess pressure from being held for longer periods of time.

At least one of the contact pieces, in particular functionally identical contact pieces of the first and second switching contacts or of the first and second contact arrangement, can be arranged on the blowing arrangement. This makes it possible, on the one hand, to position the blowing arrangement adjacent to the contact arrangements and, on the other hand, to vary the shape of the blowing arrangement independently of the contact arrangement. If required, the contact pieces can be arranged on the piston or on the cylinder or on the piston and the cylinder, in particular carried by them.

It may further be preferred that the first blowing volume, the second blowing volume and optionally the third blowing volume are designed to be gas-tight with respect to one another.

In this design, gas cannot pass from one blowing volume to another. This enables particularly defined blowing, as it is ensured that the volume of insulation fluid is only flushed to the contact arrangement associated with the blowing volume, but not to another contact arrangement, which enables a defined flow of insulation fluid. In addition, a specific volume of insulation gas is always available for each of the contact arrangements, which can be fed directly to the contact arrangement. This can increase safety. Finally, this enables a particularly simple structure.

Furthermore, it may be preferred that at least one contact piece is attached to a wall of the piston-cylinder arrangement, in particular inserted into a wall of the piston-cylinder arrangement.

A wall in/on which a contact piece is inserted/attached can preferably limit the blowing volume of the piston-cylinder arrangement. As a result, the contact piece inserted/attached in/on the wall is positioned close to the blowing volume, so that a flowing fluid can be transported from the blowing volume to the contact pieces over short distances. The contact piece can be supported at least partially by the piston-cylinder arrangement, in particular by a wall.

Furthermore, it can be advantageous that a contact piece of the first contact arrangement, a contact piece of the second contact arrangement and optionally a contact piece of the third contact arrangement are arranged on a common wall element, wherein the common wall element forms a wall of the first piston-cylinder arrangement, the second piston-cylinder arrangement and optionally the third piston-cylinder arrangement.

This design can be particularly advantageous if a switching operation is to be carried out uniformly in the contact arrangements provided, i.e. at the same time. In this design, the conveying of the insulating fluid can thus be controlled jointly, although the blowing volumes provided can still be separate from one another.

Alternatively, it may be advantageous for a contact piece of the first contact arrangement, a contact piece of the second contact arrangement and, if applicable, a contact piece of the third contact arrangement to each be arranged on a separate wall element, wherein the separate wall elements form a wall of the first piston-cylinder arrangement, the second piston-cylinder arrangement and, if applicable, the third piston-cylinder arrangement which is separate from one another.

In this embodiment, a particularly high degree of flexibility can be allowed with regard to the switching operations. This is because the aforementioned advantages can be provided effectively even if the switching operations of the contact arrangement are to take place independently of one another. In this embodiment, the control of the conveyance of the insulating fluid into a contact arrangement is independent of the other switching operations.

Furthermore, it may be preferred that at least one blowing volume is at least partially filled with synthetic air.

It has been shown that synthetic air in particular can have very good properties as an insulating medium, for example with regard to extinguishing an electric arc and reducing soot formation. Furthermore, the use of synthetic air means that SF ₆ can be dispensed with. However, it has also been shown that when synthetic air is used, a contact arrangement, for example designed as a quick earthing device, may not be easy to achieve. can be switched off, since the generation of an arc is not always possible due to speed and distance, for example from switching pins to entry contacts or generally from switching pieces. Therefore, blowing can be useful, especially when using synthetic air, so that the advantages of the invention are particularly effective here.

For further advantages and technical features of the switching arrangement, reference is made to the description of the gas-insulated switchgear, the figure and the description of the figure.

Also described is a gas-insulated switchgear comprising a switching arrangement, wherein the switching arrangement is designed as described elsewhere.

Such a gas-insulated switchgear allows in particular the advantages which have already been described above. In particular, the provision of a switching arrangement as described allows for a simple construction and simple assembly at high switching speeds.

For further advantages and technical features of the gas-insulated switchgear, reference is made to the description of the switching arrangement, the figure and the description of the figure.

Fig. 1

schematisch eine Schnittansicht einer Ausgestaltung einer Schaltanordnung gemäß der Erfindung von der Seite.

Further details, features and advantages of the subject matter of the invention emerge from the subclaims and from the following description of the figure and the associated example. In the figure:

Fig.1

schematically a sectional view of an embodiment of a switching arrangement according to the invention from the side.

In the Figure 1 a sectional view of an embodiment of a switching arrangement 10 according to the invention is shown from the side. Such a switching arrangement 10 can in particular be part of a gas-insulated switchgear.

The switching arrangement 10 according to Figure 1 comprises a plurality of at least two contact arrangements 12. Specifically, in the Figure 1 three contact arrangements 12 _a , 12 _b , 12 _c are shown, whereby this embodiment is not to be understood as limiting. The contact arrangements 12 _a , 12 _b , 12 _c each comprise a first contact piece 14 _a , 14 _b , 14 _c and a second contact piece 16 _a , 16 _b , 16 _c which are movable relative to one another in order to form an electrical connection in a touching state of the first contact piece 14 _a , 14 _b , 14 _c and the second contact piece 16 _a , 16 _b , 16 _c and to form an insulation gap in a separated state. In the Figure 1 a state is shown in which the contact pieces 14 _a , 14 _b , 14 _c and 16 _a , 16 _b , 16 _c touch each other. More precisely, the first contact pieces 14 _a , 14 _b , 14 _c are designed as contact pins which are arranged in a socket, wherein the socket forms the second contact piece 16 _a , 16 _b , 16 _c .

Furthermore, a blowing arrangement 18 is provided which serves to blow the contact arrangements 12 _a , 12 _b , 12 _c with insulating gas 20, for example with synthetic air. The blowing arrangement 18 has three blowing volumes 22 _a , 22 _b , 22 _c , wherein the contact arrangements 22 _a , 22 _b , 22 _c can each be selectively supplied with insulating gas 20 from a blowing volume 22 _a , 22 _b , 22 _c . More precisely, each contact arrangement 12 _a , 12 _b , 12 _c is assigned a blowing volume 22 _a , 22 _b , 22 _c , so that each contact arrangement 12 _a , 12 _b , 12 _c can be supplied with insulating gas 20 exclusively by a blowing volume 22 _a , 22 _b , 22 _c . The different blowing volumes 22 _a , 22 _b , 22 _c are designed to be gas-tight with respect to one another, so that a gas exchange between the individual blowing volumes 22 _a , 22 _b , 22 _c is not possible.

With regard to the blowing arrangement 18, Figure 1 that the blowing arrangement 18 has a volume-displacing piston-cylinder arrangement 24 _a , 24 _b , 24 _c , wherein the second contact pieces 16 _a , 16 _b , 16 _c from the respective contact arrangement 12 _a , 12 _b , 12 _c are arranged fixedly on the piston-cylinder arrangement 24 _a , 24 _b , 24 _c . More precisely, it is provided that the second contact pieces 16 _a , 16 _b , 16 _c are attached to a wall 26 of the piston-cylinder arrangement 24 _a , 24 _b , 24 _c , in particular inserted into a wall 26 of the piston-cylinder arrangement 24 _a , 24 _b , 24 _c . A common wall 26 is provided for all three piston-cylinder arrangements 24 _a , 24 _b , 24 _c .

Furthermore, the respective blowing volume 22 _a , 22 _b , 22 _c is connected to the corresponding contact arrangement 12 _a , 12 _b , 12 _c by a blow-out channel 28 _a , 28 _b , 28 _c through which the insulating gas 20 can flow from the blowing volume 22 _a , 22 _b , 22 _c to the corresponding contact arrangement 12 _a , 12 _b , 12 _c .

Such a switching arrangement 10 can operate as follows.

When the contact arrangements 12 _a , 12 _b , 12 _c are separated, the second contact pieces 16 _a , 16 , 16 _c are pushed together with the wall 24 in the Figure 1 to the right so that the blowing volumes 22 _a , 22 _b , 22 _c are reduced. This causes the insulating gas 20 to flow through the blow-out channel 28 _a , 28 _b , 28 _c to the corresponding contact arrangement 12 _a , 12 _b , 12 _c . An opening of the blow-out channel 28 _a , 28 _b , 28 _c can open at the switching gap. This allows efficient blowing of the switching gap. For example, it is possible to cool the switching gap or to clear the switching gap of foreign substances such as combustion products, etc. and to promote dielectric strengthening of the switching gap.

Furthermore, a kinematics 30 is shown, with which rear walls 32 _a , 32 _b , 32 _c of the piston-cylinder arrangement 24 _a , 24 _b , 24 _c can be moved in order to vary the blowing volumes 22 _a , 22 _b , 22 _c .

Claims (10)

1. Switching arrangement (10) with a plurality of at least two contact arrangements (12_a, 12_b) and a blasting arrangement (18) for blasting the contact arrangements (12_a, 12_b) with insulating gas (20), wherein the at least two contact arrangements (12_a, 12_b) each have a first contact piece (14_a, 14_b) and a second contact piece (16_a, 16_b) which can move relative to each other in order to form an electrical connection in a state in which the first contact piece (14_a, 14_b) and the second contact piece (16_a, 16_b) touch each other, and to form an insulating gap in a state in which they are isolated from each other, wherein the blasting arrangement (18) has at least two blasting volumes (22_a, 22_b), wherein a first contact arrangement (12_a) can be supplied with insulating gas (20) by a first blasting volume (22_a), and wherein a second contact arrangement (12_b) can be supplied with insulating gas (22) by a second blasting volume (22_b),
   characterized in that
   the blasting arrangement (18) has a volume-displacement piston-and-cylinder arrangement (24_a, 24_b, 24_c), wherein at least one contact piece (16_a, 16_b, 16_c) from the first contact arrangement (12_a) and from the second contact arrangement (12_b) is arranged so that it is stationary on the piston-and-cylinder arrangement (24_a, 24_b, 24_c).
2. Switching arrangement (10) according to Claim 1,
   characterized in that
   additionally at least a third blasting volume (22_c) and a third contact arrangement (12_c) are provided, wherein the third contact arrangement (12_c) can be supplied with insulating gas (20) by the third blasting volume (22_c).
3. Switching arrangement (10) according to Claim 1 or 2,
   characterized in that
   the first contact arrangement (12_a) can be supplied with insulating gas (20) exclusively by the first blasting volume (22_a), and that the second contact arrangement (12_b) can be supplied with insulating gas (20) exclusively by the second blasting volume (22_b), and that optionally the third contact arrangement (12_c) can be supplied with insulating gas (20) exclusively by the third blasting volume (22_c).
4. Switching arrangement (10) according to any of Claims 1 to 3,
   characterized in that
   the first blasting volume (22_a), the second blasting volume (22_b), and optionally the third blasting volume (22_c) are formed so that they are gas-tight relative to one another.
5. Switching arrangement according to any of Claims 2 to 4, characterized in that
   the blasting arrangement (18) has a volume-displacement piston-and-cylinder arrangement (24_a, 24_b, 24_c), wherein at least one contact piece (16_a, 16_b, 16_c) from the first contact arrangement (12_a) and from the second contact arrangement (12_b) and the third contact arrangement (12_c) is arranged so that it is stationary on the piston-and-cylinder arrangement (24_a, 24_b, 24_c).
6. Switching arrangement (10) according to any of Claims 1 to 5,
   characterized in that
   at least one contact piece (16_a, 16_b, 16_c) is placed onto a wall (26) of the piston-and-cylinder arrangement (24_a, 24_b, 24_c), in particular is inserted into a wall (26) of the piston-and-cylinder arrangement (24_a, 24_b, 24_c).
7. Switching arrangement (10) according to Claim 6,
   characterized in that
   a contact piece (16_a) of the first contact arrangement (12_a), a contact piece (16_b) of the second contact arrangement (12_b), and optionally a contact piece (16_b) of the third contact arrangement (12_b) are arranged on a common wall element (26), wherein the common wall element (26) forms a wall of the first piston-and-cylinder arrangement (24_a), the second piston-and-cylinder arrangement (24_b), and optionally the third piston-and-cylinder arrangement (24_c).
8. Switching arrangement (10) according to Claim 6,
   characterized in that
   a contact piece (16_a) of the first contact arrangement (12_a), a contact piece (16_b) of the second contact arrangement (12_b), and optionally a contact piece (16_b) of the third contact arrangement (12_b) are arranged in each case on a separate wall element (26), wherein the separate wall elements (26) in each case form a separate wall of the first piston-and-cylinder arrangement (24_a), the second piston-and-cylinder arrangement (24_b), and optionally the third piston-and-cylinder arrangement (24_c).
9. Switching arrangement (10) according to any of Claims 1 to 8,
   characterized in that
   at least one blasting volume (22_a, 22_b, 22_c) is filled at least partly with synthetic air.
10. Gas-insulated switchgear, having a switching arrangement (10),
    characterized in that
    the switching arrangement (10) is designed according to any of Claims 1 to 9.

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