A preparation method for a ceramic aluminum wire winding

Abstract

A method for preparing a ceramic aluminum wire winding comprises winding an aluminum wire around an insulating cylinder to form a prefabricated aluminum winding, adding a toothed insulating spacer while winding, and clamping the aluminum wire in the interdental grooves of the toothed insulating spacer; separating the layers of aluminum wire and the aluminum wire from the insulating cylinder by the toothed insulating spacer, thereby forming interlayer gaps between the layers of aluminum wire and between the aluminum wire and the insulating cylinder; and separating the turns of the aluminum wire in each layer by the interdental grooves, thereby forming interturn gaps between the turns of the aluminum wire in each layer; and subjecting the prefabricated aluminum winding to micro-arc oxidation / thermoelectrochemical oxidation to form a ceramic aluminum wire winding. The method for preparing a ceramic aluminum wire winding of the present invention comprises first winding a bare aluminum wire around an insulating cylinder, and then subjecting the prefabricated aluminum winding to micro-arc oxidation / thermoelectrochemical oxidation to produce a ceramic aluminum wire winding, thereby fundamentally avoiding the problem of slag shedding caused by bending the wire when making a winding using ceramic aluminum wire.

Description

Technical Field

[0001] The invention relates to a method for preparing a transformer winding, and in particular to a method for preparing the winding using a ceramic aluminum wire. Background Art

[0002] Aluminum conductor with a ceramic film layer is a new type of insulated conductor, but this type of ceramic aluminum conductor is very vulnerable to large curvature bending (CN2022107568886). Using this ceramic aluminum conductor to generate windings using conventional winding methods will cause the ceramic film layer on the surface of the ceramic aluminum conductor to fall off due to large bending, causing the conductor to be scrapped, which limits the application of this new type of conductor in windings. Summary of the Invention

[0003] The object of the present invention is to provide a method for preparing a ceramic aluminum wire winding without bending the ceramic aluminum wire, so as to overcome the defects of the prior art.

[0004] The technical solutions of the present invention are as follows:

[0005] A method for preparing a ceramic aluminum wire winding comprises the following steps:

[0006] (1) Prefabricated aluminum winding:

[0007] An aluminum conductor is wound around an insulating cylinder to form a prefabricated aluminum winding. During the winding process, toothed insulating strips are added, and the aluminum conductor is clamped in the interdental grooves of the toothed insulating strips. The toothed insulating strips are used to separate the layers of aluminum conductors and the aluminum conductors from the insulating cylinder, thereby forming interlayer gaps between the layers of aluminum conductors and between the aluminum conductors and the insulating cylinder. At the same time, the interdental grooves are used to separate the turns of the aluminum conductors in each layer, thereby forming interturn gaps between the turns of the aluminum conductors in each layer.

[0008] (2) Oxidation treatment:

[0009] The prefabricated aluminum winding is subjected to micro-arc oxidation / thermal electrochemical oxidation treatment to form a ceramic aluminum wire winding.

[0010] Furthermore, in the prefabricated aluminum winding in step (1), 10 tooth-shaped insulating gaskets are inserted between each layer of aluminum wires and between the inner layer of aluminum wires and the insulating tube, and the tooth-shaped insulating gaskets are parallel to the axial direction of the prefabricated aluminum winding.

[0011] Furthermore, the 10 tooth-shaped insulating gaskets are distributed at equal intervals.

[0012] Furthermore, the oxidation treatment in step (2) includes:

[0013] The prefabricated aluminum winding is immersed as a whole in a stainless steel barrel filled with electrolyte, the wire ends on the prefabricated aluminum winding are connected to a power supply, and the stainless steel barrel serves as a cathode. After being connected to a micro-arc oxidation / thermal electrochemical oxidation power supply, the aluminum wire on the prefabricated aluminum winding is oxidized into a ceramic aluminum wire, thereby obtaining a ceramic aluminum wire winding.

[0014] Furthermore, the oxidation treatment in step (2) includes:

[0015] 2-1: Immerse the prefabricated aluminum winding part in a stainless steel barrel filled with electrolyte. Connect the wire end of the prefabricated aluminum winding to a power source. The stainless steel barrel serves as the cathode. After connecting to a micro-arc oxidation / thermal electrochemical oxidation power source, the aluminum wire on the prefabricated aluminum winding that is in contact with the electrolyte is oxidized into a ceramic aluminum wire.

[0016] 2-2: Micro-arc oxidation / thermal electrochemical oxidation After the power supply is turned on, the prefabricated aluminum winding is rotated so that the aluminum wires on the prefabricated aluminum winding are in contact with the electrolyte in different areas, and the aluminum wires are oxidized in different areas until all the aluminum wires on the prefabricated aluminum winding are in contact with the electrolyte and oxidized to form ceramic aluminum wires, thus obtaining a complete ceramic aluminum wire winding.

[0017] Furthermore, the steps include:

[0018] (3) Coating insulation material:

[0019] An insulating material is applied to the ceramic aluminum wire in the ceramic aluminum wire winding.

[0020] Furthermore, the insulating material is an organic insulating material.

[0021] Furthermore, the organic insulating material is epoxy resin or polyimide.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] The method for preparing a ceramic aluminum wire winding of the present invention comprises first winding a bare aluminum wire on an insulating cylinder, and then subjecting the prefabricated aluminum winding to a micro-arc oxidation / thermal electrochemical oxidation treatment to prepare the ceramic aluminum wire winding. This fundamentally avoids the problem of slagging (the shedding of the surface ceramic film layer) caused by bending the wire when making windings with ceramic aluminum wire. The aluminum winding of the present invention rotates while being oxidized, so that only a portion of the winding contacts the electrolyte for oxidation. By gradually oxidizing, the problem of excessive current and excessive power load caused by an excessively large contact area between the aluminum wire and the electrolyte is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a top view of the ceramic aluminum wire winding in Example 1 of the present invention;

[0025] Figure 2 yes Figure 1Schematic diagram of the relative positions of the aluminum conductor, toothed insulating strip, and insulating tube on the cross section at point A;

[0026] Figure 3 yes Figure 1 Schematic diagram of the relative positions of the aluminum conductor, toothed insulating strip, and insulating tube on the cross section at point B;

[0027] Figure 4 Schematic diagram of the structure of the toothed insulating gasket in Example 1 of the present invention;

[0028] Figure 5 This is a schematic diagram of the relative positions of the prefabricated aluminum winding and the stainless steel barrel in Example 2 of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions of the present invention will be described clearly and completely below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0030] Example 1:

[0031] A method for preparing a ceramic aluminum wire winding comprises the following steps:

[0032] Step 1: Prefabricated aluminum winding

[0033] Aluminum conductors are wound around an insulating cylinder to form a prefabricated aluminum winding. During winding, toothed insulating strips are inserted between the aluminum conductor layers, with the aluminum conductors positioned within the interdental slots of the strips. Ten toothed insulating strips are inserted between each layer of aluminum conductors and between the inner layer of aluminum conductors and the insulating cylinder, with the strips oriented parallel to the axis of the prefabricated aluminum winding. The toothed insulating strips separate the aluminum conductors between each layer and between the aluminum conductors and the insulating cylinder, creating interlayer gaps. The interdental slots also separate the turns within each layer, creating interturn gaps between the turns within each layer.

[0034] Step 2: Oxidation treatment of prefabricated aluminum winding:

[0035] The entire prefabricated aluminum winding is immersed in a stainless steel barrel filled with electrolyte. The wire ends of the prefabricated aluminum winding are connected to a power source. The stainless steel barrel serves as the cathode. After being connected to a micro-arc oxidation / thermoelectrochemical oxidation power source, the aluminum wire on the prefabricated aluminum winding is oxidized into ceramic aluminum wire, thus obtaining a ceramic aluminum wire winding. (This micro-arc oxidation / thermoelectrochemical oxidation treatment method is an existing conventional technology. For details, please refer to patent CN2022104775920.)

[0036] like Figure 1-4As shown, the prefabricated aluminum winding mainly includes three parts: an insulating cylinder 1, a toothed insulating gasket 2, and an aluminum conductor 3. The inter-tooth grooves 201 on the toothed insulating gasket 2 are evenly spaced. The aluminum conductor 3 is wound on the insulating cylinder 1 in five layers. Toothed insulating gaskets 2 are provided between each layer of aluminum conductor and between the aluminum conductor and the insulating cylinder, so that inter-layer gaps are formed between each layer of aluminum conductor and between the aluminum conductor and the insulating cylinder. The turns of the aluminum conductor in each layer are respectively stuck in the inter-tooth grooves 201 of the toothed insulating gasket 2, so that inter-turn gaps are formed between the turns of the aluminum conductor in each layer. The toothed insulating gaskets 2 in the gaps between each layer are evenly spaced, and the toothed insulating gaskets 2 in the gaps between adjacent layers are staggered.

[0037] The aluminum conductor 3 used in this embodiment is a flat bare aluminum wire, and the corresponding interdental slot 201 is rectangular in shape. If a round aluminum wire is used, the interdental slot 201 is semicircular in shape.

[0038] The insulating strips in the transformer are made of epoxy resin, phenolic resin, glass cloth, glass fiber, impregnated paper, etc., and are not resistant to high temperatures. In this embodiment, the toothed insulating strips 2 are aluminum strips that have been treated with micro-arc oxidation or thermo-electrochemical oxidation to separate the aluminum conductor 3 and the aluminum conductor 3 from the insulating tube 1.

[0039] Example 2

[0040] like Figure 5 As shown, compared with Example 1, this embodiment is different in that step (2) oxidation treatment includes:

[0041] 2-1: The prefabricated aluminum winding is placed on a rotatable reel 4. The reel 4 is adjusted so that the prefabricated aluminum winding is partially immersed in a stainless steel barrel 5 containing an electrolyte 6. The stainless steel barrel 5 then acts as a cathode. The wire ends of the prefabricated aluminum winding and the stainless steel barrel 5 are connected to a micro-arc oxidation / thermal electrochemical oxidation power supply. When the power supply is turned on, the aluminum wire 3 on the prefabricated aluminum winding that is in contact with the electrolyte 6 is oxidized into a ceramic aluminum wire.

[0042] 2-2: Rotate reel 4 until all aluminum conductors 3 on the prefabricated aluminum winding come into contact with the electrolyte and oxidize to form ceramic aluminum conductors, resulting in a complete ceramic aluminum conductor winding. This gradual oxidation process allows only a portion of the winding to oxidize in contact with the electrolyte 6. This gradual oxidation avoids excessive power load caused by excessive contact area between the aluminum conductors 3 and the electrolyte 6.

[0043] Example 3

[0044] This embodiment is similar to Example 1, except that after the prefabricated aluminum winding is subjected to micro-arc oxidation / thermoelectrochemical oxidation to form a ceramic aluminum wire winding, the ceramic aluminum wire winding is coated with an organic insulating material (such as epoxy resin, polyimide, etc.) to form an organic-ceramic composite insulated aluminum wire winding, and the interlayer gaps and interturn gaps serve as heat dissipation channels. The coating method can be vacuum coating or cladding (see patent CN2020106183124 - A high-temperature and corona-resistant ceramic film-coated wire and its preparation method).

Claims

1. A method for preparing a ceramic aluminum wire winding, characterized in that: Including steps: (1) Prefabricated aluminum winding: An aluminum conductor is wound around an insulating cylinder to form a prefabricated aluminum winding. During the winding process, toothed insulating strips are added, and the aluminum conductor is clamped in the interdental grooves of the toothed insulating strips. The toothed insulating strips are used to separate the layers of aluminum conductors and the aluminum conductors from the insulating cylinder, thereby forming interlayer gaps between the layers of aluminum conductors and between the aluminum conductors and the insulating cylinder. At the same time, the interdental grooves are used to separate the turns of the aluminum conductors in each layer, thereby forming interturn gaps between the turns of the aluminum conductors in each layer. (2) Oxidation treatment: The prefabricated aluminum winding is subjected to micro-arc oxidation / thermal electrochemical oxidation treatment to form a ceramic aluminum wire winding.

2. The method according to claim 1, characterized in that In the prefabricated aluminum winding of step (1), 10 tooth-shaped insulating gaskets are inserted between each layer of aluminum conductors and between the inner layer of aluminum conductors and the insulating tube, and the tooth-shaped insulating gaskets are parallel to the axial direction of the prefabricated aluminum winding.

3. The method according to claim 2, characterized in that 10 tooth-shaped insulating strips are distributed at equal intervals.

4. The method according to claim 1, wherein The oxidation treatment in step (2) comprises: The prefabricated aluminum winding is immersed as a whole in a stainless steel barrel filled with electrolyte, the wire ends on the prefabricated aluminum winding are connected to a power supply, and the stainless steel barrel serves as a cathode. After being connected to a micro-arc oxidation / thermal electrochemical oxidation power supply, the aluminum wire on the prefabricated aluminum winding is oxidized into a ceramic aluminum wire, thereby obtaining a ceramic aluminum wire winding.

5. The method according to claim 1, characterized in that The oxidation treatment in step (2) comprises: 2-1: Immerse the prefabricated aluminum winding part in a stainless steel barrel filled with electrolyte. Connect the wire end of the prefabricated aluminum winding to a power source. The stainless steel barrel serves as the cathode. After connecting to a micro-arc oxidation / thermal electrochemical oxidation power source, the aluminum wire on the prefabricated aluminum winding that is in contact with the electrolyte is oxidized into a ceramic aluminum wire. 2-2: Micro-arc oxidation / thermal electrochemical oxidation After the power supply is turned on, the prefabricated aluminum winding is rotated so that the aluminum wires on the prefabricated aluminum winding are in contact with the electrolyte in different areas, and the aluminum wires are oxidized in different areas until all the aluminum wires on the prefabricated aluminum winding are in contact with the electrolyte and oxidized to form ceramic aluminum wires, thus obtaining a complete ceramic aluminum wire winding.

6. The method according to any one of claims 1 to 5, characterized in that: Also includes the steps: (3) Coating insulation material: An insulating material is applied to the ceramic aluminum wire in the ceramic aluminum wire winding.

7. The method according to claim 6, characterized in that The insulating material is an organic insulating material.

8. The method according to claim 7, characterized in that The organic insulating material is epoxy resin or polyimide.

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