Electric device for a high-voltage network

Abstract

The invention relates to an electric device (1) for a high-voltage network, comprising - at least one winding (2) which extends between an upper yoke (6) and a lower yoke (8) in the longitudinal direction (x) and is wound around a leg (3.1), - an upper yoke shield (10) which is provided on the upper yoke (6), and - a lower yoke shield (12) which is provided on the lower yoke (8). The electric device is characterized in that between the upper yoke shield (10) and the lower yoke shield (12) is at least one return-path shield (14) which is designed to be movable and is movably mounted in order to compensate for relative movements.

Description

[0001] 2024PF00305

[0002] 1

[0003] Description

[0004] Electrical device for a high-voltage network

[0005] The invention relates to an electrical device for a high-voltage network.

[0006] Electrical devices for a high-voltage network include, for example, a transformer, a transformer core, or a choke, each of which can be switched to a high-voltage supply network to transmit electrical power.

[0007] Each electrical device has at least one wound leg. In transformers with multiple wound legs, leakage flux guides, in particular yoke shields, are sometimes installed on the upper and lower yoke plates. The yoke shields connect the leakage fluxes of the wound legs and prevent electromagnetic losses and the associated temperature increases on the upper and lower yoke plates.

[0008] In single-phase transformers with only one wound leg, the magnetic flux must be guided from the upper yoke shield to the lower yoke shield to protect the yoke plates from the magnetic flux. Return shields are already used in chokes with only one wound leg. The yoke shields and the return shields are rigidly attached to the yoke plates and also rigidly to the layered iron core. After the shields are mounted, the position of the upper and lower yoke shields is fixed; in particular, they are braced against each other.

[0009] The invention is based on the objective of providing an improved electrical device that is less lossy and 2024PF00305

[0010] 2 can be operated with a higher efficiency compared to previous devices.

[0011] The problem is solved according to the invention by an electrical device having the features of claim 1.

[0012] Advantageous embodiments of the invention are the subject of the dependent claims.

[0013] The electrical device according to the invention, in particular a transformer, comprises at least one winding extending in a longitudinal direction between an upper yoke and a lower yoke, an upper yoke shield arranged on the upper yoke, and a lower yoke shield arranged on the lower yoke, wherein at least one back shield is arranged between the upper yoke shield and the lower yoke shield, which is designed to be movable in order to compensate for relative movements.

[0014] A winding is understood to mean, in particular, a primary winding and a secondary winding that are wound around a leg, or a coil of a transformer.

[0015] The upper yoke and the lower yoke are each made of a magnetizable material. The upper yoke is also called the upper magnetic yoke or upper ferromagnetic yoke. The lower yoke is also called the lower magnetic yoke or lower ferromagnetic yoke.

[0016] The electrical device can comprise a core consisting of several legs. The core has at least one wound leg and two outer legs that are unwound and designed for backflow, referred to as return legs or backflow legs.

[0017] Under backflow shielding, in particular a stray flux shielding or backflow shielding from the upper 2024PF00305

[0018] 3

[0019] Yoke shielding for the lower yoke shielding to close the magnetic circuit understood.

[0020] The electrical device is, in particular, a transformer. The electrical device can be connected to an electrical supply network, for example, in a parallel or series connection.

[0021] The electrical steel sheets of the upper yoke are pressed, for example, with two upper yoke press plates. The electrical steel sheets of the lower yoke are pressed with two lower yoke press plates. The two upper yoke press plates and the two lower yoke press plates form force-fit connections with their respective yokes. This allows for relative movement between the upper yoke press plates and the lower yoke press plates. Below the upper yoke press plates are the upper yoke shields, which are rigidly attached to the upper yoke press plates. Above the lower yoke press plates are the lower yoke shields, which are rigidly connected to the lower yoke press plates. At least one winding extends between the upper yoke shields and the lower yoke shields.In this process, at least one winding is pressed in the longitudinal direction over the upper and lower yoke shields, or between the upper and lower yoke pressure plates. If the winding expands or stretches due to the winding temperature, the distance between the upper and lower yoke shields, or between the upper and lower yoke pressure plates, changes.

[0022] The advantages achieved with the invention consist in particular in that relative movements occurring during the manufacture and operation of the electrical device, especially a transformer, between the upper yoke pressure plates (and thus also upper yoke shields) and the lower yoke pressure plates (and thus 2024PF00305) are prevented.

[0023] 4. Changes in length (including those in the lower yoke shields) can be easily compensated for and accommodated by means of the flexibly mounted back shield. In other words, the flexibly mounted back shield between the upper and lower yoke shields allows for the compensation of length changes. Furthermore, it enables virtually frictionless and stress-free movement of the yoke shields. In addition, electrical losses in the electrical device can be reduced, hot spots on the upper and lower yokes can be avoided, and efficiency can be increased.

[0024] In one possible further development, the back-end shielding is formed, for example, from stacked or layered metal sheets, in particular from stacked electrical steel sheets. For example, the electrical steel sheets are stacked or layered parallel to a transformer core sheet.

[0025] Preferably, the metal sheets are mounted so that they can move relative to each other. This allows displacements or relative movements to be compensated for largely without stress.

[0026] Furthermore, the metal sheets can be stacked in steps with overlap. In particular, the metal sheets of the back shield are stacked or layered in a stepwise overlap with the upper and lower yoke shields (also referred to as step-lap layering). For example, the metal sheets are arranged in a stepwise (or incremental) overlap with the upper and lower yoke shields at their ends (longitudinal ends / end ends) and / or sides (longitudinal sides). The metal sheets to be stacked can have different and / or the same dimensions. In particular, the metal sheets are aligned longitudinally and / or transversely to each other, stepwise overlapping and stacked directly on top of each other.

[0027] The backflow shield is arranged in particular parallel to a backflow leg and extends in 2024PF00305

[0028] 5

[0029] Longitudinal direction between the upper yoke shield and the lower yoke shield. In particular, two backflow shields can be arranged between the upper yoke shield and the lower yoke shield for each return limb.

[0030] Preferably, the back shield has a longer length than the winding. In particular, the back shield is manufactured with a longer length than the distance between the upper and lower yoke shields.

[0031] When installed between the two yoke shields in the electrical device, the return shield is compressed. In particular, when installed between the two yoke shields, the return shield runs in an arc shape or, in sections, in an S-shape, U-shape, omega-shape, or the like.

[0032] Preferably, the back shield is installed between the two yoke shields with excess length in such a way that a vertical change in length causes a horizontal change in arc. This enables a virtually frictionless and stress-free movement of the yoke shields.

[0033] Furthermore, two backflow shields can be provided for each backflow leg and arranged parallel to it.

[0034] 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. Figure 2024PF00305 shows:

[0035] FIG 1 schematically shows in perspective an electrical device with at least one winding and a movable return shield,

[0036] FIG 2 schematically shows in top view the electrical device with the core and the movable return shields and without winding, and

[0037] FIG 3 schematically shows an enlarged section of an outer leg with two backflow shields movably mounted on both sides of the leg.

[0038] Corresponding parts are marked with the same reference symbols in the figures.

[0039] Figure 1 schematically shows a perspective view of an electrical device 1 for a high-voltage network. A transverse direction y, perpendicular to the longitudinal direction x, is horizontally oriented with respect to the electrical device 1. A vertical direction z is perpendicular to both the longitudinal direction x and the transverse direction y.

[0040] In particular, electrical device 1 is a transformer. Electrical device 1 can be connected to an electrical supply network, for example in a parallel or series connection.

[0041] The electrical device 1 comprises at least one winding 2 and a core 3, comprising a central leg 3.1 around which the winding 2 is wound, and two outer legs 3.2 which are designed as unwound legs for return flow. The central leg 3.1 is configured as a wound leg 3.1. The two outer legs 3.2 are configured as unwound legs 3.2 and are also referred to as return legs or return legs. 2024PF00305

[0042] The two outer legs 3.2 and the middle leg 3.1 are connected on one side by an upper yoke 6 and on the other side by a lower yoke 8.

[0043] The metal sheets 21 (also called electrical steel sheets) of the upper yoke 6 are pressed, for example, with two upper yoke press plates 6.0. The metal sheets 21 of the lower yoke 8 are pressed with two lower yoke press plates 8.0. The two upper yoke press plates 6.0 and the two lower yoke press plates 8.0 form force-fit connections with the respective yokes 6, 8. Thus, relative movement between the upper yoke press plates 6.0 and the lower yoke press plates 8.0 is possible.

[0044] The upper yoke pressure plates 6.0 and the lower yoke pressure plates 8.0 are designed, in particular, as fixed retaining profiles. For example, the upper yoke pressure plates 6.0 and the lower yoke pressure plates 8.0 can each be designed as sheet metal profiles, in particular as C-steel profiles, L-steel profiles, U-steel profiles, or the like. These upper yoke pressure plates 6.0 and the lower yoke pressure plates 8.0 each press the associated upper yoke 6 or the lower yoke 8 and also the winding 2 together vertically.

[0045] Below the upper yoke press plates 6.0 are upper yoke shields 10, which are rigidly attached to the upper yoke press plates 6.0. Above the lower yoke press plates 8.0 are lower yoke shields 12, which are rigidly connected to the lower yoke press plates 8.0.

[0046] The at least one winding 2 extends in detail between the upper yoke shields 10 and the lower yoke shields 12 and is wound around the middle leg 3.1. The at least one winding 2 is wound longitudinally over the upper yoke shields 10 and 2024PF00305.

[0047] 8 lower yoke shields 12 pressed through the upper yoke press plates 6.0 and the lower yoke press plates 8.0 .

[0048] If the winding 2 expands or stretches as a result of the winding temperature, then the distance between the upper yoke shields 10 and the lower yoke shields 12 or between the upper yoke pressure plates 6.0 and the lower yoke pressure plates 8.0 changes.

[0049] The upper yoke press plates 6.0 and the lower yoke press plates 8.0 are each made of a magnetizable material.

[0050] The electrical device 1 comprises, in summary, the upper yoke shield 10. The upper yoke shield 10 is arranged and attached to the upper yoke pressure plates 6.0. In particular, the upper yoke shield 10 is arranged on an inner surface 6.1 of the upper yoke, specifically a surface facing the direction of the winding 2, and is rigidly connected to and held in place by these upper yoke pressure plates 6.0.

[0051] Furthermore, the electrical device 1 comprises the lower yoke shielding 12. The lower yoke shielding 12 is arranged on the lower yoke pressure plates 8.0. In particular, the lower yoke shielding 12 is arranged on a lower inner yoke surface 8.1, especially a surface surface facing the direction of the winding 2, of the lower yoke pressure plates 8.0 and is rigidly connected to and held on them.

[0052] The upper yoke shield 10 and the lower yoke shield 12 are, for example, designed as fixed retaining profiles, in particular as a sheet metal profile, for example as an I-profile, a flat profile, a profile formed from several stacked metal sheets 21, or the like. 2024PF00305

[0053] Between the upper yoke shield 10 and the lower yoke shield 12, at least one back-shield 14 is arranged, which is designed to compensate for relative movements between the upper yoke pressure plates 6.0 and the lower yoke pressure plates 8.0, and is in particular mounted in a movable manner.

[0054] The electrical device 1 can include several upper yoke shields 10 and several lower yoke shields 12.

[0055] For example, two upper yoke shields 10 can be provided, which are arranged parallel to the upper yoke press plates 6.0 at the front and rear and extend substantially over the entire length of the upper yoke press plates 6.0. Furthermore, two lower yoke shields 12 can be provided, which are arranged parallel to the lower yoke press plates 8.0 at the front and rear and extend substantially over the entire length of the lower yoke press plates 8.0.

[0056] The electrical device 1 can comprise several backflow shields 14, which extend, for example, parallel to the outer legs 3.2 between the upper yoke shield 10 and the lower yoke shield 12. Figure 1 shows, by way of example, two backflow shields 14 on each outer leg 3.2, which extend parallel to the respective leg 3.2 as connecting elements 4 between the upper yoke shield 10 and the lower yoke shield 12.

[0057] Preferably, the respective back shield 14 has an excess length relative to a distance or gap between the upper yoke shield 10 and the lower yoke shield 12.

[0058] In the state of the back shields 14 with excess length, installed between the two yoke shields 10 and 12, the respective back shield 14 is compressed. 2024PF00305

[0059] 10

[0060] In particular, the respective backstop shield 14, when installed between the two yoke shields 10 and 12, has an arc-shaped, curved, S-shaped, or similar form in at least one section 16. The compressed, arc-shaped, or curved section 16, especially its arc or curve, projects perpendicular / transversely to the longitudinal axis of the backstop shield 14. In particular, the section 16 projects in the direction of, or opposite to, the direction of, the adjacent outer leg 3.2.

[0061] The back shields 14 are connected at their ends to the upper yoke shield 10 and the lower yoke shield 12 via first connecting elements 14.1.

[0062] The electrical device 1 comprises, in summary, as core 3, the upper yoke 6, the lower yoke 8, the two unwound legs 3.2 and the wound leg 3.1, as well as four return flow shields 14 and at least two upper yoke pressure plates 6.0 and at least two lower yoke pressure plates 8.0.

[0063] The metal sheets 21 can be connected to each other at connection points by means of second connecting elements 14.2 when viewed in the longitudinal direction x.

[0064] Figure 2 shows the core 3 of the electrical device 1 without winding 2 from the front.

[0065] The core 3 comprises the middle leg 3.1 as the wound leg, the two outer legs 3.2 as the reflux leg and the upper yoke 6 as well as the lower yoke 8.

[0066] The winding 2 around the middle leg 3.1 shown in Figure 1 is not shown.

[0067] In this view, the backflow shields 14 extend directly between the upper yoke shield 10 and the lower 2024PF00305

[0068] 11

[0069] Yoke shielding 12. The backflow shielding 14 is directly connected at its free ends to the upper yoke shielding 10 and the lower yoke shielding 12 via first connecting elements 14.1.

[0070] The upper yoke pressure plates 6.0 and / or the lower yoke pressure plates 8.0 can move vertically in the direction of arrow 23 on their respective upper yoke 6 and lower yoke 8. In particular, if the winding 2 expands or stretches due to the winding temperature, the distance between the upper yoke shields 10 and the lower yoke shields 12, and, due to the rigid connection, also the distance between the upper yoke pressure plates 6.0 and the lower yoke pressure plates 8.0, can change. These movements can be easily compensated for by means of the return shields 14, which are movably mounted between the upper yoke shields 10 and the lower yoke shields 12.

[0071] Figure 3 schematically shows an enlarged section of the two unwrapped outer legs 3.2 with two backflow shields 14 that are movably mounted on both sides and at least partially arc-shaped.

[0072] In the state installed between the two yoke shields 10 and 12 in the electrical device 1, the respective back shield 14 is compressed. In particular, the back shield 14 runs in an arc-shaped (also called curved) form in sections 16, for example S-shaped, U-shaped, omega-shaped or the like.

[0073] Preferably, the respective back shield 14 is installed between the two yoke shields 10, 12 with such an excess length that a vertical change in length 18 causes a horizontal change in arc 20. This allows for a virtually frictionless and stress-free displacement or change in position of the yoke shields 10, 12 relative to each other. 2024PF00305

[0074] 12

[0075] The back shields 14 are formed from stacked electrical steel sheets. The back shields 14 are connected at their ends to the upper yoke shield 10 and the lower yoke shield 12 via first connecting elements 14.1.

[0076] The back shields 14 can be connected to each other at connection points in the longitudinal direction x by means of second connecting elements 14.2. The connecting elements 14.1, 14.2 are, for example, corresponding screw elements 14.2.1 and nut elements 14.2.2.

[0077] The components of the core 3, in particular the outer legs 3.2, the wound middle leg 3.1, and the upper yoke 6 and the lower yoke 8, are each formed from metal sheets 21, which are stacked or layered in a stepwise overlapping arrangement (also referred to as step-lap stacking). For example, the metal sheets 21 are arranged in a stepwise overlapping arrangement at their ends (longitudinal ends / end ends) and / or sides (longitudinal sides). The metal sheets 21 to be stacked can have different and / or the same dimensions.

[0078] In particular, the metal sheets 21 are aligned to each other in the longitudinal direction x and / or in the transverse direction y, overlapping each other in steps and stacked directly on top of each other. The respective back-shielding 14 is likewise formed from stacked or layered metal sheets 21, in particular from stacked electrical steel sheets, which are stacked or layered (also referred to as step-lap layering) with the upper yoke shielding 10 and the lower yoke shielding 12 in a step-lap layering arrangement.

[0079] Preferably, the metal sheets 21 are mounted so that they can move relative to each other, in particular longitudinally, as indicated by arrow 22. This results in 2024PF00305

[0080] 13. Displacements or relative movements in the longitudinal direction x can be largely compensated without stress.

[0081] The advantages achieved with the invention consist in particular in the fact that relative movements occurring during the manufacture and operation of the electrical device 1 between the upper yoke shielding 10 and the lower yoke shielding 12 can be easily compensated and absorbed by means of the at least one movably mounted back shielding 14.

[0082] 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 the person skilled in the art without leaving the scope of protection of the invention.

Claims

2024PF00305 14 Patent claims 1. Electrical device (1) for a high-voltage network with - at least one winding (2) which extends in a longitudinal direction (x) between an upper yoke (6) and a lower yoke (8) and is wound around a leg (3.1), - an upper yoke shield (10) , arranged on the upper yoke ( 6 ), and - a lower yoke shield (12) , arranged on the lower yoke ( 8 ) , characterized in that at least one back shield (14) is arranged between the upper yoke shield (10) and the lower yoke shield (12), which is designed and mounted to compensate for relative movements.

2. Electrical device (1) according to claim 1, characterized in that the back shield (14) is formed from stacked metal sheets (21).

3. Electrical device (1) according to claim 2, characterized in that the metal sheets (21) are mounted so as to be movable relative to each other.

4. Electrical device (1) according to claim 2 or 3, characterized in that the metal sheets (21) are stacked in steps with overlap.

5. Electrical device (1) according to one of the preceding claims, characterized in that the back shield (14) is arranged parallel to an outer leg (3.2) and extends in longitudinal direction (x) between the upper yoke shield (10) and the lower yoke shield (12). 2024PF00305 15 6. Electrical device (1) according to one of the preceding claims, characterized in that the back shield (14) has an excess length relative to a distance between upper yoke shield (10) and lower yoke shield (12).

7. Electrical device (1) according to one of the preceding claims, characterized in that the back shield (14) is compressed or is compressed in the state installed between the two yoke shields (10, 12).

8. Electrical device (1) according to one of the preceding claims, characterized in that the back shield (14) in the state installed between the two yoke shields (10, 12) has an arc shape at least in sections.

9. Electrical device (1) according to one of claims 6 to 8, characterized in that the back-shielding (14) is installed between the two yoke shieldings (10, 12) with excess length in such a way that a vertical change in length (18) causes a horizontal change in arc (20).

10. Electrical device (1) according to one of claims 5 to 9, characterized in that two return flow shields (14) are provided on each outer leg (3.2).

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