Electrical contacting of a moving contact of a circuit breaker

Abstract

The invention relates to a circuit breaker with a current band (1) for electrically contacting a moving contact (35) of a circuit breaker (20). The current band (1) comprises a plurality of superimposed electrically conductive conductor layers (3), a first end section (5) in which the conductor layers (3) are press-welded together, a second end section (7) in which the conductor layers (3) are press-welded together, and a central section (9) in which the conductor layers (3) are press-welded together. The invention further relates to a circuit breaker (20) and a switchgear assembly (100).

Description

[0001] The invention relates to a circuit breaker with a current band for electrically contacting a moving contact of the circuit breaker and a switchgear assembly.

[0002] A circuit breaker is designed to switch high electrical currents, especially overload and short-circuit currents. For switching, a circuit breaker has at least one movable contact that can move between two switching positions to interrupt and close a current path. Flexible current strips are often used to electrically connect the movable contact of a circuit breaker. Their flexibility allows the electrical contact to be maintained during movement. Such a current strip typically has multiple layers of electrically conductive conductors to provide flexibility and a high current-carrying capacity.

[0003] High electrical currents cause such a current-carrying conductor to heat up. This heating, in turn, increases the electrical resistance of the conductor. Therefore, to reduce the electrical resistance and the required thickness or number of conductor layers during the design of the conductor, sufficient heat dissipation is one of the key objectives. In the past, sulfur hexafluoride was often used as an insulating gas in gas-insulated switchgear. This gas has a very high density compared to other insulating gases. Consequently, sulfur hexafluoride also has high thermal conductivity and contributes significantly more to heat dissipation in a current-carrying conductor in a gas-insulated switchgear than other insulating gases. However, the use of sulfur hexafluoride as an insulating gas in switchgear is increasingly restricted and, in some cases, prohibited due to its environmental hazards.Alternative insulating gases have lower thermal conductivities than sulfur hexafluoride and therefore require alternative concepts for cooling the current bands.

[0004] From DE 197 34 968 A1, switching fingers are known which are joined together at one end and joined together individually at the other end.

[0005] DE 10 2018 220 423 A1 discloses a current band with two rigid end sections and a rigid section between them.

[0006] DE 39 28 960 A1 describes a current band made of strands, which is welded at the ends and in an area in between.

[0007] The invention is based on the objective of improving the electrical contacting of a moving contact of a power switch with a current band, particularly with regard to heat dissipation from the current band.

[0008] The problem is solved according to the invention by a circuit breaker with a current band having the features of claim 1 and a switchgear with the features of claim 11.

[0009] Advantageous embodiments of the invention are the subject of the dependent claims.

[0010] A circuit breaker according to the invention comprises a first current band for electrically contacting a moving contact of a circuit breaker. - a large number of superimposed electrically conductive conductor layers, - a first end section in which the conductor layers are press-welded together, - a second end section in which the conductor layers are press-welded together, and - a central section in which the conductor layers are press-welded together.

[0011] The current band further comprises a first intermediate section, arranged between the first end section and the middle section, and a second intermediate section, arranged between the second end section and the middle section, both of which are mechanically flexible. The flexibility of the intermediate sections is achieved, among other things, by the fact that the conductor layers in the intermediate sections are not connected to one another, in particular not press-welded together. Due to the flexibility of the intermediate sections, the end sections and the middle section of the current band are movable relative to each other. The first end section is connected to the moving contact, the second end section to a connecting element to another electrical device, and the middle section to a fixed component of the circuit breaker.The first intermediate section allows the movement of the first end section with the moving contact of the circuit breaker, and the second intermediate section allows for tolerance compensation in the connection of the current band with the connecting element, thus reducing the.

[0012] The effort and costs of connecting the moving contact to the connecting element, which would otherwise require additional effort and additional elements for tolerance compensation.

[0013] The circuit breaker also includes a moving contact and a first current band designed according to the invention, wherein the first end section of the first current band is electrically and mechanically connected to the moving contact.

[0014] The central section of the first current band is also attached to a fixed component of the circuit breaker, for example, a pole support. A fixed component of the circuit breaker is defined as a component that is not movable relative to the majority of the other components of the circuit breaker and, in particular, is not movable together with the moving contact.

[0015] The end and middle sections of the current strip are solid due to the press welding of the conductor layers. This allows the end and middle sections to be electrically and mechanically connected to a component of the circuit breaker or a component of another electrical device. For example, one end of the current strip is connected to the moving contact of the circuit breaker, and the other end is connected to an electrically conductive connecting element, which is electrically connected to a component of another electrical device. This electrically connects the moving contact to the component of the other electrical device.The central section of the current band is connected to a fixed component of the circuit breaker, such as a pole support. This fixes the current band in its central section and simultaneously thermally couples it to the fixed component, allowing heat to be dissipated from the current band to this component. The central section of the current band thus serves both to fix the current band in place and to dissipate heat.

[0016] In further embodiments of the circuit breaker according to the invention, the first intermediate section has a first bend and / or the second intermediate section has a second bend. A curved design of an intermediate section advantageously increases its flexibility and mechanical strength.

[0017] In further embodiments of the circuit breaker according to the invention, the first end section is essentially cuboid in shape, and / or the second end section is essentially cuboid in shape, and / or the middle section is essentially cuboid in shape. The cuboid shape of an end section or the middle section implies that the respective section of the current band has planar surface areas that enable a large-area connection of this section of the current band to another component, such as the moving contact, a stationary component of the circuit breaker, or a connecting element to another electrical device. This large-area connection, in turn, enables a good electrical connection, a stable mechanical connection, and / or a good thermal connection between the current band and the component connected to it.

[0018] In further embodiments of the circuit breaker according to the invention, the first end section has at least one through-hole and / or the second end section has at least one through-hole and / or the middle section has at least one through-hole. A through-hole in an end section or the middle section of the current band enables a simple, mechanically stable and cost-effective connection of this section of the current band to another component by means of a screw connection using a screw passed through the through-hole.

[0019] In one embodiment of the circuit breaker according to the invention, the first end section of the first current band is connected to the moving contact by at least one screw connection.

[0020] In a further embodiment of the circuit breaker according to the invention, the central section of the first current band is attached to a stationary component of the circuit breaker, for example, to a pole support. A stationary component of the circuit breaker is defined as a component that is not movable relative to the majority of the other components of the circuit breaker and, in particular, is not movable together with the moving contact.

[0021] The advantages of a circuit breaker according to the invention result from the advantages mentioned above of the design of the first current band according to the invention.

[0022] A switchgear assembly according to the invention comprises a circuit breaker designed according to the invention, a further electrical device, and an electrically conductive connecting element which is electrically connected to a component of the further electrical device and is electrically and mechanically connected at a first side to the second end section of the first current band of the circuit breaker. The further electrical device is, for example, a disconnect switch, and the component of the further electrical device is, for example, a switching contact of the disconnect switch.

[0023] One embodiment of the switchgear according to the invention comprises a second current band that is electrically connected to the moving contact of the circuit breaker, wherein the connecting element is electrically and mechanically connected to the second current band on a second side opposite the first side. By contacting the connecting element with both current bands on both sides, the electrical contact area of ​​the connection between the moving contact and the connecting element is increased compared to contact by only one current band, thus increasing the current-carrying capacity of the electrical connection or allowing the use of thinner current bands.

[0024] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of exemplary embodiments, which are explained in more detail in conjunction with the drawings. These drawings show: Fig. 1 a perspective view of an embodiment of a current band according to the invention, Fig. 2 a section of a side view of the in Fig. 1 of the current bands shown, Fig. 3 a perspective view of an embodiment of a circuit breaker according to the invention, Fig. 4 a block diagram of an embodiment of a switchgear according to the invention.

[0025] Corresponding parts are marked with the same reference symbols in the figures.

[0026] Fig. 1 ( Fig. 1) and Fig. 2 ( Fig. 2) show an embodiment of a current band 1 for electrically contacting a moving contact of a power switch according to the invention. Fig. Figure 1 shows a perspective view of power line 1. Fig. Figure 2 shows a section of a side view of current band 1. For better understanding, the following is included: Fig. 1 and Fig. 2. A Cartesian coordinate system with coordinates x, y, z is drawn.

[0027] The current band 1 comprises a plurality of superimposed electrically conductive conductor layers 3, a first end section 5, a second end section 7, a middle section 9, a first intermediate section 11 and a second intermediate section 13.

[0028] The conductor layers 3 are, for example, each made of copper or stainless steel. In reality, the number of conductor layers 3 is usually much larger than in the diagram. Fig. 2 shown.

[0029] The first intermediate section 11 is arranged between the first end section 5 and the middle section 9. The second intermediate section 13 is arranged between the second end section 7 and the middle section 9.

[0030] In the end sections 5, 7 and the middle section 9, the conductor layers 3 are press-welded together, so that the end sections 5, 7 and the middle section 9 are solid.

[0031] The first end section 5 is essentially cuboid in shape with two opposing planar surfaces 5.1, 5.2 and five through holes 5.3, 5.4, each running between the surfaces 5.1, 5.2. One through hole 5.3 runs centrally through the first end section 5, while the other through holes 5.4 are distributed around the through hole 5.3.

[0032] The second end section 7 is essentially cuboid in shape with two opposing planar surfaces 7.1, 7.2 and three through holes 7.3, each running between the surfaces 7.1, 7.2.

[0033] The central section 9 is essentially cuboid in shape with two opposing planar surfaces 9.1, 9.2 and two through holes 9.3, each running between the surfaces 9.1, 9.2.

[0034] In the first intermediate section 11, the conductor layers 3 are not connected to each other. Furthermore, the first intermediate section 11 has a first bend 11.1 of the current band 1. This makes the first intermediate section 11 flexible (bendable).

[0035] In the second intermediate section 13, the conductor layers 3 are also not connected to each other. Furthermore, the second intermediate section 13 has a second bend 13.1 of the current band 1. This makes the second intermediate section 13 flexible (bendable).

[0036] Fig. 3 ( Fig. Figure 3) shows a perspective view of an embodiment of a circuit breaker 20 according to the invention, wherein components and details of the circuit breaker 20 that are irrelevant for understanding the invention are not shown. The circuit breaker 20 is a vacuum switch and comprises a vacuum switching tube 21, a pole shell 23, a stationary component 25, a pole head 27, a first current band 1 and a second current band 29. Furthermore, in Fig. Figure 3 shows an electrically conductive connecting element 31, which is electrically connected to a component of another electrical device, for example, a disconnect switch. In this embodiment, the stationary component 25 of the circuit breaker 20 is a pole support.

[0037] The vacuum switching tube 21 comprises a housing 33 and a moving contact 35, which is movable relative to the housing 33 and extends from the housing 33. The vacuum switching tube 21 is arranged between the pole carrier 25 and the pole head 27. The pole carrier 25 is connected to the pole shell 23, for example by a clamping connection.

[0038] The first current band 1 is as shown by the Fig. 1 and Fig. 2 described. The first end section 5 of the first current band 1 is electrically and mechanically connected to the moving contact 35 of the vacuum switching tube 21 by screw connections 37. The surface 5.1 of the first end section 5 rests against the moving contact 35. Each screw connection 37 comprises a screw 39, which is guided through a through-hole 5.4 of the first end section 5 and screwed onto the moving contact 35.

[0039] The central section 9 of the first current band 1 is electrically and mechanically connected to the pole support 25 by screw connections 41. The surface 9.1 of the central section 9 rests against the pole support 25. Each screw connection 41 comprises a screw 43, which is guided through a through-hole 9.3 of the central section 9 and screwed to the pole support 25.

[0040] The second end section 7 of the first current band 1 is electrically and mechanically connected to the connecting element 31 by screw connections 45. The surface 7.1 of the second end section 7 rests against a first side 47 of the connecting element 31. Each screw connection 45 comprises a screw (not shown) that passes through a through-hole 7.3 of the second end section 7.

[0041] The second current band 29, like the first current band 1, has a multitude of superimposed electrically conductive conductor layers, which are press-welded together in a first end section 49 of the second current band 29. The first end section 49 of the second current band 29 rests against a second side 51 of the connecting element 31 opposite the first side 47 and is electrically and mechanically connected to the connecting element 31, for example by means of screw connections. A (in Fig. 3 (not visible) second end section of the second current band 29 is electrically connected to the moving contact 35 of the vacuum switching tube 21.

[0042] Fig. 4 ( Fig. Figure 4) shows a block diagram of an embodiment of a switchgear assembly 100 according to the invention. The switchgear assembly 100 comprises a circuit breaker 20, a further electrical device 101, and an electrically conductive connecting element 31. The circuit breaker 20 is designed as shown in Figure 4. Fig.3 described in this section. In particular, the circuit breaker 20 thus comprises a moving contact 35 and a first current band 1 and a second current band 29, wherein the current bands 1, 29 are each electrically connected to the moving contact 35 and the connecting element 31. The connecting element 31 is electrically connected to a component 103 of the electrical device 101. For example, the electrical device 101 is a disconnect switch and the component 103 is a switching contact of the disconnect switch.

[0043] Although the invention has been further illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived from them by a person skilled in the art without leaving the scope of protection of the invention. Reference symbol list 1 current band 3-layer 5 first final section 5.1, 5.2 Surface of the first end section 5.3, 5.4 Through hole of the first end section 7 second final section 7.1, 7.2 Surface of the second end section 7.3 Through hole of the second end section 9 Middle section 9.1, 9.2 Surface of the central section 9.3 Through hole of the middle section 11 first intermediate section 11.1 first bend 13 second intermediate section 13.1 second bend 20 circuit breakers 21 Vacuum switching tube 23 Polar shell 25 fixed component of the circuit breaker, pole carrier 27 Pole head 29 second current band 31 Connecting element 33 cases 35 Moving contact 37, 41, 45 Screw connection 39, 43 screw 47 first side of the connecting element 49 first end section of the second current band 51 second side of the connecting element 100 switchgear 101 other electrical equipment 103 Component of the further electrical equipment x, y, z Cartesian coordinate

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