Coil assembly and dry-type transformer

Abstract

This disclosure relates to a coil assembly (10) for a power transformer (1), comprising: a coil (20) made of cast resin and having an axial end face (30) including a coupling member (32); and a coil block (50) configured to support the coil (20) and arranged to contact the axial end face (30) and engage with the coupling member (32).

Description

Technical Field

[0001] This disclosure relates to a coil assembly for a power transformer, the coil assembly including a coil and a coil block configured to support the coil. This disclosure also relates to a transformer having a coil assembly. Background Technology

[0002] In power transformers, the coils of the coil assembly may vibrate during operation due to their relatively large size and weight. Furthermore, the dimensions of the coils may change over time or under operating conditions. In this regard, the coil block can provide mechanical stability, particularly against vibration and / or dimensional changes. Providing sufficient lifespan for the coil assembly while maintaining mechanical stability is a challenge.

[0003] The aim is to develop a coil assembly that simplifies the assembly process while ensuring robust mechanical stability and optimal stress distribution. Ideally, this arrangement would include fewer components, be easier to manufacture, and offer greater stability and performance compared to existing designs. Utility Model Content

[0004] The purpose of this disclosure is to provide a solution for coil assemblies used in power transformers, which offers longer lifespan, lower production costs, and easier assembly. In particular, its aim is to avoid or reduce the disadvantages of known solutions.

[0005] The objective of this disclosure is achieved through the features of the independent claims. Preferred embodiments are described in detail in the dependent claims, the specification, and the drawings.

[0006] This objective is achieved, in particular, by means of a coil assembly for a power transformer. The coil assembly comprises a coil made of cast resin (also known as a "resin-cast coil") having an axial end face including a coupling member. The coil assembly includes a coil block configured to support the coil, the coil block being arranged to contact the axial end face and engage with the coupling member.

[0007] In other words, specifically, this disclosure proposes a coil system for a dry-type transformer, the coil system comprising a coil having an axial end face characterized by a joining geometry. Furthermore, a block member supporting the coil is provided, which contacts the axial end face and engages with the joining geometry in the circumferential and / or radial directions. This configuration enhances the stability and support of the coil within the transformer.

[0008] Through the aspects described in this disclosure and this application, it is advantageously achieved that coils can be produced at a lower cost, while the connection between coils and coil blocks enhances mechanical stability.

[0009] Compared to known solutions, this disclosure provides additional coil fixation at the bottom of the coil via a joining member. The coil assembly can exhibit better performance in vibrating environments. The joining member can be easily and cost-effectively manufactured, for example, during coil casting.

[0010] A coil, and particularly its coil components, includes an axial end face. The axial end face typically has a flat shape and / or a generally annular shape. The axial end face generally faces away from the body of the corresponding coil component, particularly along the axial direction of the coil. It is understood that the axial end face may be placed on another axial end face or on a coil block.

[0011] Engaging members can be configured for engagement, for example, to provide a form fit or a positive fit. For example, engaging members can engage when placed on or on top of a coil member. Engaging members can have non-planar and / or three-dimensionally extended shapes for engagement. Engaging members can have or be extruded elements. Engaging members can be configured to contact and engage with a coil block. Engagement may include the engaging member at least partially surrounding the coil block (e.g., its support portion). For example, the coil block may at least partially protrude into the engaging member or into the space between its components. Engagement can provide an effective form fit relative to the coil in the radial and / or circumferential directions.

[0012] Coil blocks can contact the axial end faces directly or indirectly, for example, through direct physical contact or between them spacers, pads, or flexible members (which provide a distance but offer a mechanical link for force transmission). Coil blocks can also contact the coupling members in terms of area for load distribution.

[0013] Power transformers are known in the art. A transformer typically includes a coil assembly having at least one coil, which can be supported by coil blocks of the coil assembly. Typical coil blocks provide mechanical support for the coil, preferably electrical insulation. The longitudinal axis of the coil is typically vertically aligned. The coil can be supported by coil blocks disposed between the upper end of the coil and a support base, and between the upper end of the coil and another support base. The coil blocks can provide sufficient rigidity to prevent vertical movement of the coil relative to the support base. Transformers can be configured as single-phase, two-phase, or three-phase transformers. Therefore, a transformer can include one, two, or three coils or coil assemblies. Coil assemblies, particularly transformers, can be configured for medium and / or high voltage applications. Coil assemblies, particularly transformers, can be configured for distribution applications, such as distribution substations. The outer diameter of the coil can be at least 0.5 m and / or at most 1.5 m. The outer diameter is particularly at least 0.75 m and / or at most 1.25 m, particularly 1.1 m ± 0.1 m. The axial length of the coil can be at least 0.5 mm and / or at most 2 m. A coil may have a primary coil portion and a secondary coil portion inside the primary coil portion. For example, a wall in the form of an insulating barrier may be arranged between the two coil portions. In the axial direction, a coil may comprise two or more separate coil members stacked on top of each other, which can form a coil.

[0014] The term high voltage preferably refers to voltages above 12 kV, 36 kV, 72 kV, or 1100 kV. High voltage preferably refers to nominal voltages ranging from above 12 kV, 36 kV, or 72 kV to 550 kV or 1100 kV, such as 145 kV, 245 kV, or 420 kV, or even higher. The term medium voltage preferably refers to voltages above 1 kV, 12 kV, or 36 kV. Medium voltage preferably refers to nominal voltages ranging from above 1 kV, 12 kV, or 36 kV to 72 kV, such as 5 kV, 10 kV, 25 kV, or 70 kV.

[0015] The coil is made of or comprises casting resin, particularly configured as a resin-cast coil. The coil typically comprises a metal winding that can be cast with epoxy resin. The coil may include casting resin as a component of a composite material, such as a composite material comprising casting resin and fibrous material embedded in the casting resin. The fibrous material may be wound, for example, arranged substantially parallel to and / or substantially along the metal winding.

[0016] The coil assembly may have a support base. The support base is typically configured to support the coil. The support base can support the coil from at least one side. Supporting the coil can be understood as providing a foundation and / or fixation. The support base may include a support beam. The support base may extend generally at an angle or perpendicular to the axial direction of the coil. The support base may support more than one coil, for example, two or three coils included in the coil assembly.

[0017] A coil block can be arranged between a support base and a coil. The coil block can provide at least an indirect connection between the support base and the coil. The coil block can contact the support base and / or the coil indirectly or directly. The coil block can provide electrical insulation of the coil relative to ground. The coil block can include a substantially monolithic structure and / or a block shape. The block shape can include a structure that is at least substantially rigid and / or inflexible, specifically configured to bear a load in at least one direction. The coil block can have two support surfaces facing away from each other.

[0018] It can be specified that two or more, particularly three or four, connecting members and two or more, particularly three or four coil blocks are arranged and distributed substantially equidistantly along the axial end face in the circumferential direction of the coil. Each coil block can be assigned to one of the connecting members. This ensures uniform distribution of support around the coil, enhances its stability, and reduces stress points.

[0019] The joining members, particularly each joining member, may include a pair of protrusions projecting axially from an axial end face. The protrusions of the pair may be arranged at a distance from each other along the axial end face and / or circumferentially relative to the coil, for example, to surround a coil block. The coil block may be arranged in segments between the protrusions of the pair. The joining members, particularly the protrusions, may be trapezoidal and / or block-shaped. This allows for a secure fit of the coil block within the joining members, thereby enhancing stability.

[0020] A pair of protrusions may include two side edges. These two side edges may face each other and / or may extend substantially parallel to the radial direction of the coil. A corresponding coil block, such as a coil block that engages with the pair of protrusions, may be segmented between the two side edges to provide a form-fit and / or orthogonal fit. This form-fit arrangement ensures that the coil block is securely held in place relative to the coil, reducing or preventing movement during operation.

[0021] The coil block may include a support portion. The support portion may extend axially. The support portion may have a generally rectangular or square cross-sectional shape. The support portion may correspond to the thickness of the coil, particularly to its primary or secondary coil side. The support portion may have a generally flat support surface. The support surface is configured to contact the axial end face. The support portion may be arranged between two protrusions of a pair of projections, particularly between two side edges. The support surface can provide uniform contact and load distribution between the coil and the coil block.

[0022] The coil block may include or be composed of a fiber-reinforced polymer compound and / or an electrical insulating material. The fiber-reinforced polymer compound may include glass fibers and / or carbon fibers and / or thermosetting resins, wherein the fibers may be embedded in the thermosetting resin. The thermosetting resin may include epoxy resin. The coil block may be a monolithically molded casting. The coil block may include ribs extending substantially perpendicular to the extension of the coil. Therefore, the electrical and / or mechanical properties of the coil assembly can be enhanced. The coil block can also be manufactured at low cost and has an extended lifespan.

[0023] The bonding member can be integrally formed with and / or integrally formed with the primary coil side of the coil. The bonding member can be a cast portion of the coil. This integral structure can enhance the structural cohesion between the coil and the bonding member.

[0024] The coil may include a primary coil side and a secondary coil side, wherein the secondary coil side may be radially arranged inside the primary coil side. A wall may be provided between the primary coil side and the secondary coil side. A connecting member may be formed in or together with the primary coil side. This arrangement is designed to optimize the spatial configuration and stability of the coil within the transformer. It may be sufficient if the connecting member is located only on the primary coil side and not on the secondary coil side.

[0025] The primary coil side and / or the secondary coil side may comprise or be substantially composed of a polymer compound, for example, a polymer compound made electrically insulating, particularly including epoxy or thermosetting resins, carbon fibers, and / or glass fibers. The polymer compound is particularly fiber-reinforced. One or more coil sides may be produced by casting or molding processes. Joining members may be integrally formed with the primary coil side, for example, as one or more protrusions thereon.

[0026] Each coil block may include a primary support portion for the primary coil side and a secondary support portion for the secondary coil side, specifically support portions extending axially relative to the coil and arranged radially relative to each other. If configured, a wall may extend between the two support portions. This two-part design aims to ensure adequate support for both the primary and secondary coil sides of the coil, while allowing for adjustment of electrical performance as needed.

[0027] The coil assembly may include a flexible member. The flexible member may be arranged between the coil block and the coil. The flexible member may be in the form of a pad and / or may be substantially flat. The flexible member may contact the coil block and the coil on opposite sides, particularly extending the contact across the surface areas on both sides to distribute the load. The axial thickness of the flexible member may be less than 30 mm, less than 20 mm, or less than 15 mm, particularly 10 mm ± 5 mm. The flexible member may include or be made of electrically insulating materials, particularly including rubber, polymer compounds, and / or silicone resins. The flexible member can provide a damping effect and protect other components of the coil assembly from vibration-induced failures.

[0028] The coil assembly may include another support base for supporting the coil on a side opposite to the support base, for example, by partitioning the upper and lower sides of the coil. The coil assembly may include another coil block disposed between the other support base and the coil. The coil assembly may include another flexible member disposed between the other coil block and the coil. The support base and the other support base may be connected, for example, by a connecting rod extending along the coil. Therefore, the mechanical stability of the coil assembly can be enhanced.

[0029] This objective can also be achieved by a dry-type transformer comprising one / the coil assembly, particularly wherein the coils of the coil assembly can be configured to be arranged on top of one / the coil block of the coil assembly. The dry-type transformer may comprise two or three coils, particularly coils arranged in a row.

[0030] This objective is also achieved through a method for producing one type of coil assembly. The method includes casting a coil, providing a coil block, placing the coil on the coil block, and engaging the coil block with a coupling member. This method is designed to ensure a reliable and efficient process for assembling the coil assembly.

[0031] In this disclosure, the term "or" may be replaced with "and / or". Therefore, when "or" is used, it does not necessarily mean that only alternatives are mentioned. Attached Figure Description

[0032] These and other aspects of this disclosure will become apparent and elucidated with reference to the embodiments described below.

[0033] In the attached diagram: Figure 1 A portion of a dry-type transformer is shown in perspective. Figure 2 A portion of another dry-type transformer is shown in perspective; and Figure 3 Shown in perspective Figure 2 The coil block of the transformer.

[0034] List of reference numerals 1. Power Transformer 10. Coil assembly 20 coils 22 outer diameter 24 Primary coil side 26 wall 27. Partition wall 28 Secondary coil side 30 Axial end face 32 Jointing components 34. Protrusion 36 Edges 50 coil blocks 52 Supporting Part 54. Primary Support Section 56 Support surface 58 Secondary support section 60 Support base Detailed Implementation This description includes procedural or methodological aspects that describe the structural features of this disclosure; in this way, the structural features can be well understood. It is emphasized to the reader that these structural features can be readily extracted from the described context, and there is no issue of intermediate generalization to form aspects of this disclosure. It is also emphasized to the reader that, although possibly taken out of context, any structural feature described below can be understood as an aspect of this disclosure to distinguish it from known solutions.

[0035] Figure 1 A dry-type transformer 1 including a coil assembly 10 is partially shown, wherein coils 20 are configured to be arranged on top of coil blocks 50. Currently, three coils 20 are arranged on top of multiple coil blocks 50. Each coil 20 is arranged on top of four coil blocks 50. The coil assembly 10 includes three coils 20, one coil for each of the three electrical phases, and the transformer 1 is configured to be electrically coupled to the three coils 20.

[0036] Three coils 20 are made of or comprise cast resin (e.g., also referred to as cast resin coils). A support base 60 of the coil assembly 10 is configured to support the coils 20 via coil blocks 50. The coil blocks 50 are arranged between the support base 60 and the coils 20, and are thus configured to support the coils 20. The support base 60 includes steel beams.

[0037] The coil 20 includes a radially inner secondary coil side 28 and an outer primary coil side 24 separated by a wall 26. The wall 26 is arranged radially between its primary coil side 24 and secondary coil side. The wall 26 projects axially into the coil block 50, particularly into the support portion 52 or its gap. The wall 26 extends axially beyond the coil sides 24, 28 on both sides.

[0038] The coil block 50 is composed of an electrically insulating fiber-reinforced polymer compound. The fiber-reinforced polymer compound includes glass fibers or carbon fibers and thermosetting resins inlaid with the corresponding fibers.

[0039] The coil assembly 10 includes a top support base 60 and a bottom support base 60. Each coil 20 stands on and engages with four coil blocks 50, which stand on and are connected to the bottom support base 60 (e.g., by bolts). At the top, each coil 20 is supported by four coil blocks 50 coupled to the support base 60, for example, by bolts.

[0040] Therefore, four coil blocks 50 are provided on both sides of each coil 20, and they are distributed approximately equidistantly along the axial end face 30 of the coil 20 in the circumferential direction of the coil 20.

[0041] Each axial end face 30 of the coil 20, which stands on and / or is supported by the coil block 50, includes four engaging members 32 that are substantially equidistant along the axial end face 30 and in the circumferential direction of the coil 20. The engaging members 32 correspond to the coil block 50. Each bottom coil block 50 engages with one of the engaging members 32 through its support portion 52 and contacts the corresponding axial end face 30.

[0042] The engagement between each coil 20 and the corresponding four coil blocks 50 is effective in the circumferential direction of the coil 20. Given that the four coil blocks 50 engage circumferentially along the axial end faces 30, this engagement is similarly effective in all radial directions. The coil blocks 50, fixed to the respective support bases 60, provide secure positioning of the coil 20.

[0043] In the axial direction, each coil 20 comprises two separate coil components stacked on top of each other to form the respective coil 20. For example, the outer diameter 22 of each coil 20 is 1.1m ± 0.1m. Here, the three coils 20 are arranged in a row.

[0044] A partition 27 is arranged between two adjacent coils 20, which shields one coil 20 from the other coil 21. The partition 27 may be electrically insulated. The partition 27 may be fastened to one or two support bases 60.

[0045] For electrical purposes, each coil block 50 has three ribs that extend substantially perpendicular to the extension of the coil 20 it supports.

[0046] The coil block 50 can contact the primary coil side 24 of the coil 20 via an electrically insulating flexible member between the coil block 50 and the coil 20, the electrically insulating flexible member having a thickness of 10 mm.

[0047] Figure 2 The lower side or bottom of the coil assembly 10 of the dry-type transformer 1 is shown. The coil assembly 10 includes a coil 20 made of cast resin, and the coil has an axial end face 30. The axial end face 30 points downward and / or towards the coil block 50. The axial end face 30 is substantially annular and / or circular.

[0048] The axial end face 30 includes four engaging members 32 that are substantially equidistantly distributed along the axial end face 30 in the circumferential direction of the coil 20. Four coil blocks 50 of the coil assembly 10 support the coil 20, are arranged in contact with the axial end face 30, and each coil block engages with one of the four engaging members 32. The coil blocks 50 are supported by a support base 60 including a steel beam. The coil 20 is arranged on top of the coil blocks 50.

[0049] The coil 20 includes a primary coil side 24 and a secondary coil side 28, the secondary coil side being radially arranged inside the primary coil side, with a wall 26 between them. Both coil sides 24 and 28 have an axial end face 30. A connecting member 32 is formed in the primary coil side 24, particularly with its axial end face 30. Specifically, the connecting member 32 is integrally formed with or within the primary coil side 24, for example, as one or more protrusions of the primary coil side 24.

[0050] from Figure 2 As can be seen, each coil block 50 includes a support portion 52 for engaging with a connecting member. The support portion includes a primary support portion 54 for the primary coil side 24 and a secondary support portion 58 for the secondary coil side 28. The support portions 54 and 58 extend axially relative to the coil 20. The support portions 54 and 58 are arranged radially apart from each other relative to the coil. Therefore, a gap is formed between the support portions 54 and 58, for example, to accommodate a wall 26 separating the primary coil side 24 and the secondary coil side 28.

[0051] exist Figure 2 The bottom shows details relating primarily to one of the four joining members 32.

[0052] The connecting member 32 includes a pair of protrusions 34 that project axially from the axial end face 30. The pair of protrusions 34 are arranged at a certain distance from each other along the axial end face 30 and are used to surround the support portion 52 of the coil block 50 from both sides.

[0053] The primary support portion 54 of the support portion 52, which has a flat support surface 56, contacts the axial end face 30 of the primary coil side 24 between the protrusions 34. The secondary support portion 58 of the support portion 52 (which also has a flat support surface 56) contacts the axial end face 30 of the secondary coil side 28, but does not engage with the connecting member or protrusion.

[0054] The pair of protrusions 34 include two side edges 36 that face each other and are substantially parallel to each other and / or extend parallel to the radial direction of the coil 20. The main support portion 54 is segmented between the two side edges 36 to provide a form fit.

[0055] The primary coil side 24 and the secondary coil side 28 comprise a fiber-reinforced polymer compound that is electrically insulating, and particularly comprises thermosetting resin and / or glass fiber. The coil sides 24 and 28 have been manufactured by casting or molding processes. A bonding member 32 is integrally formed with the primary coil side 24.

[0056] manufacture Figure 2 The coil assembly 10 may include a cast coil 20, a coil block 50, and a coil 20 placed on the coil block 50 to engage the coil block 50 with the engagement member 32.

[0057] Figure 3 It shows Figure 2 A coil block 50. The coil block 50 includes a support portion 52 having a primary support portion 54 and a secondary support portion 58. Each portion 54, 58 has a substantially flat support surface 56 on its top for supporting the coil 20. The primary support portion 54 can be engaged with the engagement member 32 of the coil 20 by being positioned between the protrusions 34 of the engagement member 32 (e.g., ...). Figure 2 (As shown).

Claims

1. A coil device (10) for a power transformer, characterized in that, The coil device (10) includes: The coil (20) is made of cast resin and has an axial end face (30) including a joining member (32); and A coil block (50) is configured to support the coil (20) and is arranged to contact the axial end face (30) and engage with the engagement member (32).

2. The coil device (10) according to claim 1, characterized in that, Two or more of the connecting members (32) and two or more of the coil blocks (50) are arranged and distributed substantially equidistantly along the axial end face (30) in the circumferential direction of the coil (20).

3. The coil device (10) according to claim 1, characterized in that, Along the axial end face (30), three or four of the connecting members (32) and three or four of the coil blocks (50) are arranged and distributed substantially equidistantly in the circumferential direction of the coil (20).

4. The coil device (10) according to claim 2, characterized in that, The connecting member (32) includes a pair of protrusions (34) axially projecting from the axial end face (30), wherein the protrusions (34) of the pair of protrusions (34) are arranged at a distance from each other along the axial end face (30) for surrounding the coil block (50).

5. The coil device (10) according to claim 4, characterized in that, The pair of protrusions (34) includes two side edges (36) that face each other and / or extend substantially parallel to the radial direction of the coil (20), wherein corresponding coil blocks (50) are segmented between the two side edges (36) to provide a form fit.

6. The coil device (10) according to claim 5, characterized in that, The coil block (50) includes a support portion (52) having a substantially flat support surface (56) that contacts the axial end face (30).

7. The coil device (10) according to claim 6, characterized in that, The support portion (52) is arranged between two of the two protrusions (34) of the pair of protrusions (34).

8. The coil device (10) according to claim 6, characterized in that, The support portion (52) is arranged between the two side edges (36).

9. The coil device (10) according to any one of claims 1 to 5, characterized in that, The joining member (32) is integrally formed with the primary coil side (24) of the coil (20).

10. The coil device (10) according to claim 9, characterized in that, The coil (20) includes a primary coil side (24) and a secondary coil side (28), wherein the secondary coil side (28) is radially arranged inside the primary coil side (24), and wherein the connecting member (32) is formed in the primary coil side (24).

11. The coil device (10) according to claim 10, characterized in that, Each coil block (50) includes a primary support portion (54) for the primary coil side (24) and a secondary support portion (58) for the secondary coil side (28), the primary support portion (54) and the secondary support portion (58) extending axially relative to the coil (20) and arranged radially relative to each other relative to the coil (20).

12. The coil device (10) according to claim 11, characterized in that, The coil (20) has an outer diameter (22), wherein the outer diameter (22) is at least 0.5m and / or at most 1.5m.

13. The coil device (10) according to claim 12, characterized in that, The outer diameter (22) is at least 0.75m and / or at most 1.25m.

14. The coil device (10) according to claim 12, characterized in that, The outer diameter (22) is 1.1m ± 0.1m.

15. A dry-type transformer, characterized in that, The coil device (10) includes any one of claims 1 to 14, wherein the coil (20) is configured to be arranged on top of the coil block (50).

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