阅读说明：本技术 一种干式变压器高压线圈绕制方法及干式变压器高压线圈 (Dry-type transformer high-voltage coil winding method and dry-type transformer high-voltage coil ) 是由 张军海 叶彪 张绮雯 郭敬旺 莫向松 余小平 彭景伟 廖冬虹 黄伟峰 李太山 于 2021-06-09 设计创作，主要内容包括：本发明公开了一种干式变压器高压线圈绕制方法及干式变压器高压线圈,本发明的方法包括：获取模具,并在模具的表面做脱模处理；获取铜线,对铜线进行绝缘处理；所述绝缘处理方法包括：在铜线外表面包绕一层绝缘薄膜,再在绝缘薄膜的外表面层包绕绝缘胶皮；将绝缘处理后的铜线采用饼式绕制的方法在所述模具上进行绕制,形成饼式线圈；对所述饼式线圈进行合模浇筑,得到干式变压器高压线圈。本发明通过在铜线外表面包绕一层绝缘薄膜,再在绝缘薄膜的外表面层包绕绝缘胶皮,提高了变压器的绝缘性和可靠性。(The invention discloses a method for winding a high-voltage coil of a dry-type transformer and the high-voltage coil of the dry-type transformer, wherein the method comprises the following steps: obtaining a mold, and performing demolding treatment on the surface of the mold; obtaining a copper wire and carrying out insulation treatment on the copper wire; the insulation treatment method comprises the following steps: wrapping a layer of insulating film on the outer surface of the copper wire, and wrapping an insulating rubber sheet on the outer surface layer of the insulating film; winding the insulated copper wire on the die by adopting a cake winding method to form a cake coil; and carrying out die assembly and pouring on the cake-shaped coil to obtain the high-voltage coil of the dry-type transformer. According to the invention, the insulation property and reliability of the transformer are improved by wrapping the insulating film on the outer surface of the copper wire and wrapping the insulating rubber on the outer surface layer of the insulating film.)

1. A method for winding a high-voltage coil of a dry type transformer is characterized by comprising the following steps:

obtaining a mold, and performing demolding treatment on the surface of the mold;

obtaining a copper wire and carrying out insulation treatment on the copper wire; the insulation treatment method comprises the following steps: wrapping a layer of insulating film on the outer surface of the copper wire, and wrapping an insulating rubber sheet on the outer surface layer of the insulating film;

winding the insulated copper wire on the die by adopting a cake winding method to form a cake coil;

and carrying out die assembly and pouring on the cake-shaped coil to obtain the high-voltage coil of the dry-type transformer.

2. A method for winding a high-voltage coil of a dry-type transformer as claimed in claim 1, wherein said insulation film is a polyester film.

3. The method for winding the high-voltage coil of the dry-type transformer as claimed in claim 1, wherein the insulation rubber comprises a first insulation rubber and a second insulation rubber, the first insulation rubber and the second insulation rubber are integrally formed, the first insulation rubber is arranged on the upper surface layer of the winding insulation film, and the second insulation rubber is arranged on one side of the first insulation rubber; and a plurality of pressure grooves with equal intervals are arranged on the second insulating rubber.

4. A method for winding a high-voltage coil of a dry-type transformer as claimed in claim 1, wherein a reinforcing insulation layer is formed between two adjacent layers of the first few layers of the high-voltage coil during the winding of the copper wire.

5. A method for winding high-voltage coil of dry-type transformer as claimed in claim 4, wherein during the winding of copper wire, the axial ends of each layer of the rest windings of said high-voltage coil except the first few layers of windings are painted with insulating varnish.

6. A method for winding a high-voltage coil of a dry-type transformer as claimed in claim 1, wherein the outermost surface of the high-voltage coil is provided with a nano-material coating.

7. A method for winding a high-voltage coil of a dry-type transformer as claimed in claim 1, wherein the method for winding the coil comprises the following steps: winding a copper wire into a plurality of layers of wire cakes, wherein the plurality of layers of wire cakes are connected in sequence; when winding each layer of wire cake, winding the wire cake to the upper part of the wire cake from the lower part of the wire cake; after the layer of the wire cake is wound, transposition processing is carried out, so that the copper wire is wound from the upper position of the wound wire cake to the lower position of the adjacent wire cake to be wound.

8. A method for winding a high-voltage coil of a dry-type transformer as claimed in claim 7, wherein during transposition, a transposition part of a copper wire is wrapped by DuPont paper, and the transposition part comprises a part extending from the last of the upper position of the wire cake of the current layer to the beginning of the lower position of the wire cake to be wound.

9. The method for winding the high-voltage coil of the dry-type transformer as claimed in claim 8, wherein the transposed part wrapped by the DuPont paper is wrapped by the polyester fiber cloth.

10. A dry-type transformer high-voltage coil, characterized by being prepared by the method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of dry-type transformers, in particular to a dry-type transformer high-voltage coil winding method and a dry-type transformer high-voltage coil.

Background

Dry type transformers refer to transformers which are cooled by natural air or forced air without being immersed in insulating oil, and are widely used in places such as local lighting, high-rise buildings, airports, and the like. The dry-type transformer coil plays an important role in the operation reliability of the dry-type transformer, and in order to adapt to the requirements of the modern society, the insulation of the transformer coil is improved, the product requirements are met, and the product quality is ensured.

The high-voltage coil of the transformer has a high voltage level, and if the high-voltage coil has low insulation, local leakage may cause damage which is difficult to estimate. The prior dry type transformer coil generally has the problems of low insulation and easy local leakage.

Disclosure of Invention

In view of the above technical problems, an object of the present invention is to provide a method for winding a high-voltage coil of a dry-type transformer and a high-voltage coil of a dry-type transformer, which solve the problems of low insulation and local leakage of the conventional dry-type transformer.

The invention adopts the following technical scheme:

a method for winding a high-voltage coil of a dry type transformer comprises the following steps:

obtaining a mold, and performing demolding treatment on the surface of the mold;

obtaining a copper wire and carrying out insulation treatment on the copper wire; the insulation treatment method comprises the following steps: wrapping a layer of insulating film on the outer surface of the copper wire, and wrapping an insulating rubber sheet on the outer surface layer of the insulating film;

winding the insulated copper wire on the die by adopting a cake winding method to form a cake coil;

and carrying out die assembly and pouring on the cake-shaped coil to obtain the high-voltage coil of the dry-type transformer.

Optionally, the insulating film is a polyester film.

Optionally, the insulating rubber includes a first insulating rubber and a second insulating rubber, the first insulating rubber and the second insulating rubber are integrally formed, the first insulating rubber is disposed on the upper surface layer of the winding insulating film, and the second insulating rubber is disposed on one side of the first insulating rubber; and a plurality of pressure grooves with equal intervals are arranged on the second insulating rubber.

Optionally, during the process of winding the copper wire, a reinforcing insulating layer is arranged between two adjacent layers of the first few layers of windings of the high-voltage coil.

Optionally, in the process of winding the copper wire, in the remaining windings of the high-voltage coil except the first several layers of windings, two axial ends of each layer of winding are respectively brushed with insulating varnish.

Optionally, the outermost surface of the high-voltage coil is provided with a nano-material coating.

Optionally, the cake-type winding method includes: winding a copper wire into a plurality of layers of wire cakes, wherein the plurality of layers of wire cakes are connected in sequence; when winding each layer of wire cake, winding the wire cake to the upper part of the wire cake from the lower part of the wire cake; after the layer of the wire cake is wound, transposition processing is carried out, so that the copper wire is wound from the upper position of the wound wire cake to the lower position of the adjacent wire cake to be wound.

Optionally, when the transposition is performed, the transposition portion of the copper wire is wrapped with dupont paper, and the transposition portion includes a portion extending from the last of the upper position of the wire cake of the layer to the beginning of the lower position of the adjacent wire cake to be wound.

Optionally, the transposition part wrapped by the dupont paper is wrapped by the polyester fiber cloth.

The high-voltage coil of the dry-type transformer is prepared by the method.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the outer surface of the copper wire is wrapped with the insulating film, and then the outer surface layer of the insulating film is wrapped with the insulating rubber, so that large bubble discharge can not be generated in the coil when the high-voltage coil works, the partial discharge quantity is reduced, the possibility of insulation aging and insulation layer breakdown caused by partial discharge is reduced, and the insulation property and reliability of the transformer are improved.

Drawings

Fig. 1 is a schematic flow chart illustrating a method for winding a high-voltage coil of a dry-type transformer according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating a copper wire after being subjected to an insulation treatment according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a pancake coil according to an embodiment of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments, and it should be noted that, in the premise of no conflict, the following described embodiments or technical features may be arbitrarily combined to form a new embodiment:

the first embodiment is as follows:

referring to fig. 1-3, fig. 1 illustrates a method for winding a high-voltage coil of a dry-type transformer according to the present invention, which includes:

step S1, obtaining a mould and carrying out demoulding treatment on the surface of the mould;

in a specific implementation, the demolding treatment on the surface of the mold may include:

uniformly coating a release agent on the surface of the mold;

after the release agent is uniformly coated, a polyester film is further laid on the mold.

Step S2, obtaining a copper wire and carrying out insulation treatment on the copper wire; the insulation treatment comprises the steps of wrapping a layer of insulation film 1 on the outer surface of a copper wire and wrapping an insulation rubber sheet on the outer surface layer of the insulation film 1; FIG. 2 is a schematic diagram showing a copper wire after insulation treatment, wherein the outer surface of the copper wire is wrapped by an insulating film 1, and the outer surface layer of the insulating film 1 is wrapped by an insulating rubber;

optionally, the insulating film is a polyester film.

Short partial discharges can cause dielectric damage throughout the channel, and electrolysis of the discharge can accelerate oxidation of the insulation and corrode the insulation, thereby reducing the life of the transformer. Partial discharge is a main cause of deterioration of insulation and breakdown of insulation, which degrades insulation of the transformer.

In the implementation process, the outer surface of the copper wire is wrapped with the insulating film, and then the outer surface layer of the insulating film is wrapped with the insulating rubber, so that large bubble discharge cannot be generated in the coil when the high-voltage coil works, the partial discharge amount is reduced, the possibility that the insulating layer of the coil is punctured due to the partial discharge is reduced, and the insulativity and the reliability of the transformer are improved.

Optionally, the insulating rubber includes a first insulating rubber 2 and a second insulating rubber 3, the first insulating rubber 2 and the second insulating rubber 3 are integrally formed, the first insulating rubber 2 is disposed on the upper surface layer of the winding insulating film 1, and the second insulating rubber 3 is disposed on one side of the first insulating rubber 2; and a plurality of pressure grooves 31 with equal intervals are arranged on the second insulating rubber sheet 3.

The pressure groove 31 can be used for guaranteeing the uniformity of the winding displacement distance, and the distance between the coils can be adjusted by the pressure groove 31 according to the high-voltage coils of different models and production requirements, so that the dielectric strength and the partial discharge level are further guaranteed, and the insulation property and the reliability of the transformer are improved.

Step S3, winding the copper wire after insulation treatment on the die by adopting a cake winding method to form a cake coil 100;

optionally, the cake-type winding method includes: winding a copper wire into a plurality of layers of wire cakes 101, wherein the plurality of layers of wire cakes 101 are connected in sequence; when winding each layer of the wire cake 101, winding the wire cake 101 from the lower part of the wire cake 101 to the upper part of the wire cake 101 step by step; after the layer of the wire cake 101 is wound, transposition processing is carried out, so that a copper wire is wound from the upper position of the wound wire cake 101 to the lower position of the adjacent wire cake 101 to be wound.

In a specific implementation, the transposition process can be implemented by the following steps:

after the wire cake 101 on the layer is wound, bending the copper wire by using a bending tool, and firstly folding the copper wire to the direction of the adjacent wire cake 101 by 90 degrees so that the copper wire faces to the direction of the adjacent wire cake 101; then, bending the wire downwards by 90 degrees according to the line width direction, so that the copper wires are distributed along the radial direction of the adjacent wire cakes 101; then, the line width is added according to the radial thickness of the coil, the bending position of the copper wire at the lower part of the wire cake 101 is determined, and the copper wire is bent by 90 degrees towards the direction of the adjacent wire cake 101, so that the copper wire faces the direction of the adjacent wire cake 101; and finally, bending the copper wires by 90 degrees in the direction facing the winding direction of the adjacent wire cakes 101, so that the copper wires are distributed in the winding direction of the adjacent wire cakes 101, thereby finishing transposition processing.

Further, during transposition processing, a transposition portion 102 of the copper wire is wrapped by DuPont paper, and the transposition portion 102 comprises a portion extending from the last of the upper position of the wire cake 101 in the layer to the beginning of the lower position of the adjacent wire cake 101 to be wound.

By wrapping the transposition part 102 with the DuPont paper, specifically, the transposition part can be wrapped by two layers of DuPont paper with the thickness of 0.08mm, so that the insulation thickness of the outer surface of the transposition part 102 is ensured, the length of the copper wire during transposition is noted in the whole bending process, and the copper wire is not loose or tight after being wrapped and insulated by transposition treatment.

Optionally, after the transposition portion 102 is wrapped with dupont paper, a 0.18mm polyester fiber cloth can be wrapped as an insulation treatment, so that the transposition portion 102 is prevented from reducing the turn-to-turn insulation due to the transposition treatment.

Furthermore, in the process of winding the copper wire, a reinforcing insulating layer is arranged between two adjacent layers of the first few layers of windings of the high-voltage coil.

For example, a reinforcing insulating layer is provided between the first layer of windings and the second layer of windings;

specifically, the reinforcing insulating layer can be made of a steel plate, an epoxy resin plate or a glass fiber reinforced plastic plate.

In the implementation process, the reinforcing insulating layer is arranged between two adjacent layers of the first layers of windings of the high-voltage coil, so that the mechanical strength between the first layers of windings of the high-voltage coil is good, deformation resistance is facilitated, and the insulating capability can be further improved.

Optionally, in the process of winding the copper wire, in the remaining windings of the high-voltage coil except the first several layers of windings, two axial ends of each layer of winding are respectively brushed with insulating varnish.

Specifically, the axial length L of the insulating varnish can be selected to be between 30 and 80 millimeters.

Optionally, the outermost surface of the high-voltage coil is provided with a nano-material coating.

In the implementation process, the nano material coating is arranged on the outermost layer surface of the high-voltage coil, so that the creeping discharge phenomenon of the high-voltage coil can be prevented, the insulating material is prevented from being broken by partial discharge, and the insulativity is improved.

And step S4, carrying out die assembly and pouring on the cake-shaped coil 100 to obtain the high-voltage coil of the dry-type transformer.

Specifically, the die assembly casting method comprises the following steps:

sending the cake-type coil 100 into an oven, keeping the temperature of the oven at 80 ℃, and preserving the heat for 4-6 hours;

gradually raising the temperature of the oven from 80 ℃ to 100 ℃ for 4 hours;

keeping the temperature of the oven at 100 ℃ and preserving the heat for 4 hours;

gradually raising the temperature of the oven from 100 ℃ to 130 ℃, wherein the temperature raising time is 0.5 hour;

keeping the temperature of the oven at 130 ℃, and keeping the temperature for 8-10 hours;

and naturally cooling the oven to 70 ℃, and moving the coil out of the oven.

In the specific embodiment, the die comprises a special square shaft for a winding machine, a simple winding frame, an adjustable stay fixing clamp, an adjustable fixing nut, a wedge-shaped wood stay, a lower wedge-shaped wood stay, (a fastening bolt) and an inner coil supporting insulation cylinder, wherein the special square shaft for the winding machine is vertically arranged, the simple winding frame is fixed on the special square shaft for the winding machine through the fastening bolt, the adjustable stay fixing clamp is fixed on the simple winding frame through the adjustable fixing nut, the clamp opening direction of the adjustable stay fixing clamp is outward, the upper wedge-shaped wood stay is outward, the lower wedge-shaped wood stay is inward placed in the adjustable stay fixing clamp, and the inner coil supporting insulation cylinder is tightly supported.

And taking out the mold after mold closing and pouring to obtain the low-voltage coil of the dry-type transformer.

Example two:

the invention relates to a high-voltage coil of a dry-type transformer, which is prepared by the following method:

obtaining a mold, and performing demolding treatment on the surface of the mold;

obtaining a copper wire and carrying out insulation treatment on the copper wire; the insulation treatment method comprises the following steps: wrapping a layer of insulating film on the outer surface of the copper wire, and wrapping an insulating rubber sheet on the outer surface layer of the insulating film;

winding the insulated copper wire on the die by adopting a cake winding method to form a cake coil 100;

in the implementation process, the outer surface of the copper wire is wrapped with the insulating film in the winding process, and then the outer surface of the insulating film is wrapped with the insulating rubber, so that large bubble discharge cannot be generated in the coil when the high-voltage coil works, the partial discharge capacity is reduced, the possibility that the insulating layer of the coil is broken down due to the partial discharge is reduced, and the insulativity and the reliability of the transformer are improved.

And carrying out die assembly and pouring on the cake-shaped coil 100 to obtain the high-voltage coil of the dry-type transformer.

Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes should fall within the scope of the claims of the present invention.