Contacting a moving contact of a power circuit breaker
The electrical contacting device with conductive elements and shielding heat sinks addresses conductor layer breaks in circuit breakers, enabling a compact design by dissipating heat and shielding electric fields, thus preventing arcing and maintaining functionality.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SIEMENS AG
- Filing Date
- 2025-12-18
- Publication Date
- 2026-07-09
AI Technical Summary
Circuit breakers with flexible current strips experience conductor layer breaks leading to sharp edges that cause electric field peaks and potential arcing, necessitating bulky insulation or increased spacing, which complicates the design.
An electrical contacting device with a conductive contact element, flexible current bands, and shielding heat sinks that dissipate heat and shield electric fields, preventing conductor layer protrusion and arcing.
Enables a compact circuit breaker design by reducing the need for insulation and spacing, enhancing current-carrying capacity and preventing electrical flashovers.
Smart Images
Figure EP2025088016_09072026_PF_FP_ABST
Abstract
Description
[0001] 2024P18339 DE
[0002] 1
[0003] Description
[0004] Contacting a moving contact of a circuit breaker
[0005] The invention relates to an electrical contacting device for a moving contact of a circuit breaker.
[0006] 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. A current strip used in this way usually has a large number of superimposed electrically conductive conductor layers to provide flexibility and a high current-carrying capacity. It is practically unavoidable that after numerous switching cycles of the circuit breaker, some of the conductor layers of the current strip will break.To maintain the functionality of a current band even in the event of such breaks in individual conductor layers, a current band typically has more conductor layers than are actually required for the currents it is intended to conduct. The ends of outer, broken conductor layers detach from the inner conductor layers and protrude outwards from the current band. Because the conductor layers are very thin, the outwardly protruding broken conductor layers have sharp edges, which can lead to field peaks in the electric field at these edges. These peaks can, in turn, cause electrical arcing between the current band and adjacent electrical conductors if such arcing is not prevented.To avoid such flashovers, for example, massive electrically insulating walls or barriers are placed between the current bands and adjacent conductors and / or the distances between the current bands and the conductors are increased, thereby increasing the installation space of the circuit breaker.
[0007] The invention is based on the objective of enabling the contacting of a moving contact of a circuit breaker with current bands, which in particular allows for a compact design of the circuit breaker without massive electrically insulating walls or barriers. 2024P18339 DE
[0008] 2
[0009] The object is achieved according to the invention by an electrical contacting device of a moving contact of a circuit breaker with the features of claim 1 and a circuit breaker with the features of claim 12.
[0010] Advantageous embodiments of the invention are the subject of the dependent claims.
[0011] An electrical contacting device according to the invention for a moving contact of a circuit breaker comprises
[0012] - an electrically conductive contact element that is electrically and force- and / or form-fit connected to the moving contact,
[0013] - at least one flexible current band with one end that is electrically and materially, force- and / or form-fit connected to the contact element, and
[0014] - at least one shielding heat sink connected to at least one current band and configured to dissipate heat from the current band and to shield electric fields generated by the current band.
[0015] An electrical contacting device according to the invention enables the supply of electric current to a moving contact of a circuit breaker via at least one flexible current band and a contact element. For this purpose, the contact element is electrically and force-fit and / or positively connected to the moving contact, and the at least one flexible current band is electrically connected to the contact element. Furthermore, at least one current band is connected to a heat sink to dissipate heat from the current band. This heat dissipation advantageously increases the current-carrying capacity of the current band, or, compared to a design without heat dissipation, allows the thickness of the current band to be reduced to achieve the desired current-carrying capacity. The heat sink is also designed to shield electric fields generated by the current band.This allows, for example, the distance between the current strip and adjacent electrical conductors to be reduced, or eliminates the need for massive electrically insulating walls or barriers to prevent electrical flashovers between the current strip and these conductors.
[0016] One embodiment of an electrical contacting device according to the invention has an electrically conductive connecting body which is electrically and materially, force-fit and / or form-fit connected to each current band. The connecting body is thus electrically connected to the contact element by at least one flexible current band, which 2024P18339 DE
[0017] 3
[0018] The connecting body is electrically connected to the moving contact of the circuit breaker. By electrically contacting the connecting body, an electrical connection with the moving contact can thus be established. Unlike the contact element, the connecting body does not move together with the moving contact and therefore provides a fixed electrical contact.
[0019] In a further embodiment of an electrical contacting device according to the invention, each current band has a plurality of superimposed electrically conductive conductor layers. As already explained above, the design of a current band with a plurality of superimposed electrically conductive conductor layers enables flexibility while maintaining a high current-carrying capacity of the current band.
[0020] In a further embodiment of an electrical contacting device according to the invention, each shielding heat sink has cooling fins. The cooling fins improve the dissipation of heat from the shielding heat sink to the air surrounding the shielding heat sink by increasing the surface area of the shielding heat sink.
[0021] In a further embodiment of an electrical contacting device according to the invention, the surface of each cooling fin is rounded. The rounding of the cooling fin surfaces prevents field peaks at the edges and corners of these surfaces, which could lead to electrical arcing between the surfaces and adjacent electrical conductors.
[0022] In a further embodiment of an electrical contacting device according to the invention, the surface of each cooling fin has a concave surface area facing a current band. This ensures that the cooling fins serve, on the one hand, to shield electric fields generated by a current band, and on the other hand, that sufficient space is available between a cooling fin and a current band for heat dissipation from the cooling fin by airflow around the cooling fin.
[0023] In a further embodiment of an electrical contacting device according to the invention, each current band has a bend with a convex surface area facing a shielding heat sink and facing away from the contact element. For example, each shielding heat sink extends at least partially around the bend of at least one current band. According to this embodiment, 2024P18339 DE
[0024] 4
[0025] In the electrical contacting device according to the invention, each current band bends between a shielding heat sink and the contact element and is at least partially shielded to the outside by the shielding heat sink. The bending of a current band enables flexible electrical contact between the contact element and the current band during movement of the contact element. During these movements, the conductor layers of the current band, and especially their ends, are subjected to mechanical stress, which leads to the breakage of individual conductor layers over time. Broken conductor layers on the outside detach from inner conductor layers, particularly in the area of the bend, due to the stress in this region. The shielding heat sink prevents these detached conductor layers from protruding far outwards from the rest of the current band, as the shielding heat sink obstructs them.The shielding heat sink thus not only serves to dissipate heat from the current band and shield electric fields, but also acts as a barrier for detached conductor layers of the current band, which without this barrier would protrude far outwards from the current band and could lead to field enhancements at the edges and corners of these detached conductor layers.
[0026] In a further embodiment of an electrical contacting device according to the invention, each shielding heat sink is made of an electrically conductive material, in particular a metal. In particular, each shielding heat sink is made of an electrically conductive material with good thermal conductivity, for example aluminum, so that the shielding heat sinks, in addition to shielding electric fields, ensure good heat dissipation from the current bands.
[0027] In a further embodiment of an electrical contacting device according to the invention, at least one current band and a shielding heat sink are arranged on each of two opposite sides of the contact element. The current bands are, for example, arranged between the shielding heat sinks. This causes the shielding heat sinks to form a "cage" around the current bands, which shields the electric fields generated by the current bands from the outside and limits the protrusion of conductor layers detaching from the current bands.
[0028] A circuit breaker according to the invention has a moving contact and a contacting device for the moving contact designed according to the invention. The advantages of a circuit breaker according to the invention result from the advantages of an electrical contacting device according to the invention mentioned above. 2024P18339 DE
[0029] 5
[0030] 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:
[0031] FIG 1 shows a block diagram of an embodiment of a circuit breaker according to the invention,
[0032] FIG 2 shows a perspective view of an embodiment of a contacting device according to the invention for a moving contact of a circuit breaker,
[0033] FIG 3 shows a first side view of the contacting device shown in Figure 2,
[0034] FIG 4 shows a second side view of the contacting device shown in Figure 2,
[0035] FIG 5 schematically shows a section of a current band of the contacting device shown in Figure 2.
[0036] Corresponding parts are marked with the same reference symbols in the figures.
[0037] Figure 1 (FIG 1) shows a block diagram of an embodiment of a circuit breaker 1 according to the invention. The circuit breaker 1 is designed as a vacuum switch comprising a vacuum switching tube 3 with a housing 5 in which a fixed contact 7 and a movable contact 9 are arranged in a vacuum. The position of the fixed contact 7 relative to the housing 5 is fixed. The movable contact 9 is movable relative to the housing 5 between a first switching position, in which the movable contact 9 is in contact with the fixed contact 7, and a second switching position, in which the movable contact 9 is spaced apart from the fixed contact 7. The movable contact 9 has a contact bar 10 extending from the housing 5. The directions of movement of the movable contact 9 are indicated in Figure 1 by a double arrow. The circuit breaker 1 also has a contacting device 11 for the movable contact 9.An embodiment of a contacting device 11 is described below with reference to Figures 2 to 5.
[0038] Figures 2 to 4 show an embodiment of a contacting device 11 according to the invention for the moving contact 9 of the circuit breaker 1. Figure 2 (FIG 2) shows a perspective view of the contacting device 11. Figure 3 (FIG 3) shows a 2024P18339 DE
[0039] 6
[0040] Figure 4 (FIG 4) shows a second side view of the contacting device 11. For better understanding, a Cartesian coordinate system with coordinates x, y, z is shown in Figures 2 to 4.
[0041] The contacting device 11 is arranged below the vacuum interrupter tube 3 of the circuit breaker 1 and comprises a contact element 13, a connecting body 15, four current bands 17, two shielding heat sinks 19 and an insulating rod 21. The terms "top" and "bottom" refer here to the representation in Figures 2 to 4 and not necessarily to an arrangement in operation of the circuit breaker 1.
[0042] The contact element 13 is made of an electrically conductive material, for example aluminum, and is electrically and force-fit and / or positively connected to the moving contact 9 of the circuit breaker 1. For example, the contact rod 10 of the moving contact 9 is connected to the contact element 13 by a clamp. The moving contact 9 and the contact element 13 are thus moved together.
[0043] The connecting body 15 is made of an electrically conductive material, for example, aluminum, and is arranged below and spaced apart from the contact element 13. Unlike the contact element 13, the position of the connecting body 15 is fixed relative to the housing 5; that is, the connecting body 15 does not move together with the moving contact 9 of the vacuum switching tube 3. The connecting body 15 has a contact surface 18 via which it can be electrically contacted.
[0044] Each current band 17 electrically connects the contact element 13 and the connecting body 15. An upper end 23 of the current band 17 is electrically and materially, force-fit, and / or form-fit connected to the contact element 13. For example, the upper end 23 of the current band 17 is materially bonded to the contact element 13, for example by soldering or welding, in particular by electron beam welding. A lower end region 25 of the current band 17 is electrically and force-fit connected to the connecting body 15 by screw connections as described in more detail below.
[0045] Figure 5 (FIG 5) schematically shows a section of a current strip 17. Each current strip 17 has a plurality of superimposed electrically conductive conductor layers 26, which are made, for example, of copper and whose ends are press-welded together. In reality, the current strip 17 has a significantly larger number of conductor layers 26 than shown in Figure 5.
[0046] 7
[0047] as shown in Figure 5. The end region 25 is solid due to the press welding of the lower ends of the conductor layers 26. This allows the end region 25 to be provided with through holes 27 for the screws of the aforementioned screw connections. A contact area 28 of the end region 25, which abuts the connecting body 15, is, for example, silver-plated to ensure good electrical contact with the connecting body 15.
[0048] Two current bands 17 run on a first side 29 of the contact element 13 and the connecting body 15. The two other current bands 17 run on a second side 30 of the contact element 13 and the connecting body 15 opposite the first side 29.
[0049] A shielding heat sink 19 is electrically and frictionally connected to the end regions 25 of the two current bands 17 arranged on the first side 29 of the contact element 13 and the connecting body 15, with the shielding heat sink 19 bearing against surface areas of these end regions 25 facing away from the connecting body 15. The shielding heat sink 19 and the end regions 25 are connected to the connecting body 15 by the aforementioned screw connections. For these screw connections, the shielding heat sink 19 has through-holes 32 for each screw (not shown), which are guided through the through-hole 32 of the shielding heat sink 19 and a through-hole 27 of the end region 25 of a current band 17 to the connecting body 15, to which the screw is fastened.The screw connections thus press the shielding heat sink 19 and the end regions 25 of the current bands 17 together and the end regions 25 of the current bands 17 against the connecting body 15.
[0050] The other shielding heat sink 19 is electrically and force-fit connected to the end regions 25 of the two current bands 17 arranged on the second side 30 of the contact element 13 and the connecting body 15, wherein the shielding heat sink 19 and the end regions 25 of these current bands 17 are connected to the connecting body 15 in an analogous manner by screw connections.
[0051] Surface areas 16 of the connecting body 15, where current bands 17 bear, are flat to ensure good electrical and thermal contact between the current bands 17 and the connecting body 15. 2024P18339 DE
[0052] 8
[0053] Each shielding heat sink 19 is configured to dissipate heat from the current bands 17 connected to it and to shield electric fields generated by these current bands 17. For this purpose, each shielding heat sink 19 is made of an electrically conductive material, in particular a metal with good thermal conductivity such as aluminum, and has several cooling fins 31. The surface 33 of each cooling fin 31 is rounded to prevent field peaks of electric fields at the edges and corners of the surface 33. Furthermore, the surface 33 of each cooling fin 31 has a concave surface region 35 facing a current band 17. Each current band 17 has a bend 37 with a convex surface region 39 facing a shielding heat sink 19 and away from the contact element 13. Each shielding heat sink 19 extends at least partially around the bends 37 of the current bands 17 connected to it.This prevents the shielding heat sink 19 from allowing broken outer conductor layers 26 of a current band 17, which detach from inner conductor layers 26, to protrude far outwards from the current band 17.
[0054] The insulating rod 21 is made of an electrically insulating material and is firmly connected to the contact element 13. The contact element 13 and the moving contact 9 of the circuit breaker 1 can be moved via the insulating rod 21. The insulating rod 21 is guided through a passage 41 in the connecting body 15.
[0055] Although the invention has been further illustrated and described 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 departing from the scope of protection of the invention. 2024P18339 DE
[0056] 9
[0057] Reference symbol list
[0058] 1 circuit breaker
[0059] 3 vacuum switching tube
[0060] 5 cases
[0061] 7 Fixed contact
[0062] 9 Moving contact
[0063] 10 contact rods
[0064] 11 Contacting device
[0065] 13 Contact element
[0066] 15 connecting bodies
[0067] 16 Surface area of the connecting body 17 Current band
[0068] 18 connection area
[0069] 19 Shielding heat sinks
[0070] 21 Insulating rod
[0071] 23 End of a current band
[0072] 25 End range of a current band
[0073] 26 Ladder position
[0074] 27 Through hole
[0075] 28 Contact area
[0076] 29 first page
[0077] 30 second page
[0078] 31 cooling fins
[0079] 32 Passage opening
[0080] 33 Surface area of a cooling fin
[0081] 35 Surface area of a cooling fin
[0082] 37 bend
[0083] 39 Surface area of a bend
[0084] 41st round
[0085] x, y, z Cartesian coordinate
Claims
2024P18339 DE 10 Patent claims 1. Electrical contacting device (11) of a moving contact (9) of a circuit breaker (1), comprising - an electrically conductive contact element (13) which is electrically and force- and / or form-fit connected to the moving contact (9), - at least one flexible current band (17) with an end (23) that is electrically and materially, force- and / or form-fit connected to the contact element (13), and - at least one shielding heat sink (19) that is connected to at least one current band (17) and is configured to dissipate heat from the current band (17) and to shield electric fields generated by the current band (17).
2. Contacting device (11) according to claim 1 with an electrically conductive connecting body (15) which is electrically and materially, force- and / or form-fit connected to each current band (17).
3. Contacting device (11) according to claim 1 or 2, wherein each current band (17) has a plurality of superimposed electrically conductive conductor layers (26).
4. Contacting device (11) according to one of the preceding claims, wherein each shielding heat sink (19) has cooling fins (31).
5. Contacting device (11) according to claim 4, wherein the surface (33) of each cooling fin (31) is rounded.
6. Contacting device (11) according to claim 4 or 5, wherein the surface (33) of each cooling fin (31) has a concave surface area (35) facing a current band (17).
7. Contacting device (11) according to one of the preceding claims, wherein each current band (17) has a bend (37) with a convex surface area (39) facing a shielding heat sink (19) and away from the contact element (13).
8. Contacting device (11) according to claim 7, wherein each shielding heat sink (19) extends at least partially around the bend (37) of at least one current band (17). 2024P18339 DE 11 9. Contacting device (11) according to one of the preceding claims, wherein each shielding heat sink (19) is made of an electrically conductive material, in particular of a metal.
10. Contacting device (11) according to one of the preceding claims, wherein at least one current band (17) and one shielding heat sink (19) are arranged on each of two opposite sides (29, 30) of the contact element (13).
11. Contacting device (11) according to claim 10, wherein the current bands (17) are arranged between the shielding heat sinks (19).
12. Circuit breaker (1) with a moving contact (9) and a contacting device (11) of the moving contact (9) designed according to one of the preceding claims.