CN114300255A

CN114300255A - High-voltage winding preparation method and high-voltage winding

Info

Publication number: CN114300255A
Application number: CN202111647805.1A
Authority: CN
Inventors: 马斌; 张鑫鑫; 马婷婷; 刘超; 张小容
Original assignee: Jiangsu Shemar Electric Co Ltd
Current assignee: Jiangsu Shemar Electric Co Ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2022-04-08
Anticipated expiration: 2041-12-29
Also published as: CN114300255B

Abstract

The application discloses a high-voltage winding preparation method, which comprises the following steps: the method comprises the following steps: the conducting wire is wound along the peripheral surface of the winding body in the circumferential direction to form a high-voltage coil, and a tap is formed in the winding process of the conducting wire; step two: placing the tap joint in a protection cavity of the tool connecting piece and connecting and fixing the tap joint with the tool connecting piece; step three: placing the winding body wound with the high-voltage coil as a body to be injected into a mold of an injection machine, and injecting high-temperature vulcanized silicone rubber at the periphery of the body to be injected so that the high-voltage coil and the winding body are coated by the high-temperature vulcanized silicone rubber; step IV: and removing the tool connecting piece to obtain the high-voltage winding of which the tap is exposed outside the high-temperature vulcanized silicone rubber. The application also discloses a high-voltage winding of the dry-type transformer, which is manufactured by adopting the preparation method. The high-temperature vulcanized silicone rubber injection process enables the high-pressure insulating layer to be more stable, the mechanical property to be higher and the service life to be longer.

Description

High-voltage winding preparation method and high-voltage winding

Technical Field

The application relates to the technical field of power transformers, in particular to a high-voltage winding and a preparation method thereof.

Background

At present, transformers can be divided into: oil-immersed transformers, dry-type transformers, gas transformers. The dry type transformer has the advantages of no oil, fire resistance, long service life, energy conservation, low noise, simple maintenance, safety, reliability and the like. The dry-type transformers currently on the market are mostly resin-cast high-voltage winding dry-type transformers and open dry-type transformers. Although dry-type transformers have been developed greatly in the last 10 years, the problems of insulation cracking, poor heat conduction, severe operating environment and the like still exist in operation.

Disclosure of Invention

Aiming at the defects of the prior art, one of the purposes of the application is to provide a high-voltage winding preparation method, the high-voltage winding can be prepared, and the high-temperature vulcanized silicone rubber injection process enables a high-voltage insulating layer to be more stable and have higher mechanical property, and meanwhile, the high-voltage winding preparation method has better bonding property with a high-voltage coil and a winding body and longer service life.

In order to achieve the purpose, the technical scheme adopted by the application is as follows: a preparation method of a high-voltage winding comprises the following steps:

the method comprises the following steps: the conducting wire is wound along the peripheral surface of the winding body in the circumferential direction to form a high-voltage coil, and a tap is formed in the winding process of the conducting wire;

step two: placing the tap joint in a protection cavity of the tool connecting piece and connecting and fixing the tap joint with the tool connecting piece;

step three: and putting the winding body wound with the high-voltage coil into a mold of an injection machine as a body to be injected, and injecting high-temperature vulcanized silicone rubber at the periphery of the body to be injected so that the high-voltage coil and the winding body are coated by the high-temperature vulcanized silicone rubber.

Step IV: and removing the tool connecting piece to obtain the high-voltage winding of which the tap is exposed outside the high-temperature vulcanized silicone rubber.

The method can be used for preparing the high-voltage winding, and the high-temperature vulcanized silicone rubber injection process enables the high-voltage insulating layer to be more stable and higher in mechanical property, and meanwhile, the high-voltage winding has better bonding performance with a high-voltage coil and a winding body and longer service life.

Preferably, the winding body includes a supporting cylinder and a winding portion on an outer circumferential surface of the supporting cylinder, and in the step (r), the wire is wound on the winding portion to form the high-voltage coil. The high-voltage coil is wound by the winding body, the winding of the lead is firmer, and the formed high-voltage coil structure has better mechanical strength and better heat dissipation capability.

Preferably, in the step (r), the conductive wire includes a first conductive wire wound from the first end of the winding portion to the middle of the winding portion in the axial direction of the support cylinder and led out of three taps, and a second conductive wire wound from the middle of the winding portion to the second end of the winding portion in the axial direction of the support cylinder and led out of the other three taps. The tap finally forms a tap switch which can be used for regulating voltage of the dry-type transformer according to different operation conditions.

Preferably, in the second step, the protection cavity is a stepped hole, the tap is welded in the stepped hole, and the tap is fixedly connected to the stepped hole, so that the tap is prevented from being covered by silicon rubber and being incapable of being used for wiring in the injection process.

Preferably, the inner wall of the stepped hole is provided with threads, and before the step three, the step hole is connected with a bolt, so that the six stepped holes can be prevented from being filled with silicon rubber, and the six taps can be prevented from being coated with the silicon rubber and then cannot be used for wiring.

Preferably, before the first step, the support cylinder and the winding part are made of glass fiber impregnated with epoxy resin. The supporting cylinder and the winding part are prepared separately, materials are saved most, cost can be saved, the glass fiber epoxy resin composite material is low in cost, light in weight and good in mechanical property, and meanwhile, the carbon emission amount in the production process of the composite material is low, so that the composite material is more green and environment-friendly and has more excellent performance.

Preferably, the winding part comprises a plurality of winding plates, and before the first step, the plurality of winding plates are uniformly and circumferentially adhered and fixed on the outer peripheral surface of the supporting cylinder, so that the wires are more firmly wound on the outer peripheral surface of the supporting cylinder by uniformly adhering the winding plates in the circumferential direction, and the wires can be uniformly supported.

Preferably, before the first step, a plurality of winding grooves are formed in the winding plate, so that a plurality of comb teeth are formed on the winding plate. The coil can be arranged between two adjacent comb teeth on the winding plate, and the coil is wound on the comb-shaped winding plate, so that the stability is improved, and the coil is prevented from shifting. Meanwhile, a wire is wound in each winding groove, high-voltage coils can be reasonably distributed and arranged, each section of coil is arranged at intervals, a cake-shaped coil or a multi-section layered coil can be formed, the stress of the coil structure is balanced, and the mechanical strength is good.

Preferably, in the step (c), the high-temperature vulcanized silicone rubber covers the high-voltage coil and the winding body through integral vacuum injection and fills the gap between the high-voltage coil and the winding body and the two ends of the winding body, so that the insulation performance and the mechanical performance of the high-voltage winding are integrally improved.

Another object of the present application is to provide a high voltage winding, which is manufactured by the above-mentioned method for manufacturing a high voltage winding. The high-voltage winding has the advantages of good fireproof performance, low-temperature resistance, aging resistance and short-circuit resistance test capability, excellent electrical insulation performance, energy conservation and environmental protection.

The beneficial effect of this application is: different from the situation of the prior art, the high-voltage winding preparation method can be used for preparing the high-voltage winding, and the high-voltage insulating layer is more stable and has higher mechanical property, better bonding property with a high-voltage coil and a winding body and longer service life due to the high-temperature vulcanized silicone rubber injection process; compared with liquid silicon rubber, the high-temperature vulcanized silicone rubber filler is uniformly dispersed, and the dry-type transformer cannot generate partial discharge due to filler agglomeration, so that the overall performance of the dry-type transformer is better.

Drawings

Fig. 1 is a front view of a dry-type transformer 10 according to an embodiment of the present application;

fig. 2 is a plan view of a dry type transformer 10 according to an embodiment of the present application;

fig. 3 is a front view of an assembled core 110 according to an embodiment of the present application;

FIG. 4 is an enlarged view at G of FIG. 2;

fig. 5 is a perspective view of a bobbin 1310 according to an embodiment of the present application;

FIG. 6 is a cross-sectional view of a support cartridge 1311 of an embodiment of the present application;

fig. 7 is a perspective view illustrating a high voltage coil 1320 of an embodiment of the present application wound around a bobbin 1310;

FIG. 8 is a schematic perspective view of a high voltage winding 130 according to an embodiment of the present application;

fig. 9 is a schematic perspective view of a tool attachment 101 according to an embodiment of the present application

FIG. 10 is a schematic circuit diagram of a high voltage coil 1320 according to an embodiment of the subject application;

FIG. 11 is a partial cross-sectional view of a high voltage winding 130 according to an embodiment of the present application;

FIG. 12 is a partial cross-sectional view of another embodiment of the high voltage winding 230 of the present application;

FIG. 13 is a partial cross-sectional view of a high voltage winding 330 according to yet another embodiment of the present application;

fig. 14 is a partial cross-sectional view of a high voltage winding 430 according to yet another embodiment of the present application.

Detailed Description

As required, detailed embodiments of the present application will be disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the application and that they may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present application in virtually any appropriately detailed manner, including employing various features disclosed herein in connection with which such features may not be explicitly disclosed.

The terms "connected" and "connected" as used herein, unless otherwise expressly specified or limited, are to be construed broadly, as meaning either directly or through an intermediate. In the description of the present application, it is to be understood that the directions or positional relationships indicated by "upper", "lower", "end", "one end", etc. are based on the directions or positional relationships shown in the drawings, and are only for convenience of describing the present application and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific direction, be constructed in a specific direction and operate, and thus, should not be construed as limiting the present application.

As shown in fig. 1 to 3, the dry-type transformer 10 is a three-phase transformer, i.e., a phase, and a phase, i.e., the dry-type transformer 10 includes three single-phase transformers 100. The three transformers 100 may be arranged to form a linear or triangular structure according to the structure of the core 110, and the three transformers 100 have a symmetrical structure. The dry-type transformer 10 may be an isolation transformer, a variable frequency transformer, a test transformer, or the like.

In one embodiment, with continued reference to fig. 1-3, three transformers 100 are arranged to form a linear configuration, and the dry-type transformer 10 includes an iron core 110, three low voltage windings 120, and three high voltage windings 130. The iron core 110, the low voltage winding 120 and the high voltage winding 130 are sequentially arranged from inside to outside. The iron core 110 includes three columnar iron cores 111, an upper iron yoke 112 located at the upper ends of the three columnar iron cores 111, and a lower iron yoke 113 located at the lower ends of the three columnar iron cores 111, the three low-voltage windings 120 are respectively sleeved on the peripheries of the three columnar iron cores 111, and the three high-voltage windings 130 are respectively sleeved on the peripheries of the three low-voltage windings 120, that is, the three columnar iron cores 111, the three low-voltage windings 120, and the three high-voltage windings 130 are sequentially sleeved one by one from inside to outside. The columnar iron core body 111 is formed by overlapping multiple layers of silicon steel sheets, binding and fixing are carried out on the multiple layers of silicon steel sheets by using a binding belt, the radial section of the columnar iron core body 111 is roughly in an oval shape or a circular shape or other shapes as long as the columnar iron core body can be accommodated in a hollow cavity of the low-voltage winding 120, and limitation is not carried out here. The upper and

lower yokes

112 and 113 are also formed by stacking a plurality of silicon steel sheets, and the three columnar iron cores 111 are fixedly connected to form the three-phase iron core 110 shown in fig. 3.

Illustratively, the present application provides a simple method of assembling the core 110, the low voltage winding 120, and the high voltage winding 130. The lower iron yoke 113 of the iron core 110 is firstly formed by overlapping multiple layers of silicon steel sheets and is arranged at the bottom of the dry-type transformer 10, then multiple layers of silicon steel sheets are respectively inserted at two ends and the middle part of the lower iron yoke 113 to form three columnar iron core bodies 111, then the low-voltage winding 120 and the high-voltage winding 130 are sequentially sleeved outside the columnar iron core bodies 111, and finally multiple layers of silicon steel sheets are horizontally inserted at the upper ends of the three columnar iron core bodies 111 to form the upper iron yoke 112, so that the assembly of the iron core 110, the low-voltage winding 120 and the high-voltage winding 130 is completed.

Referring to fig. 1 and 2, a core clip 140 is disposed on an outer side of the core 110, and the core clip 140 is formed by connecting three clips to each other to form a structure similar to a channel, i.e., the core clip 140 is integrally formed in an "Contraband" shape. Wherein the middle clip is disposed close to the core 110 and the other two clips are disposed toward a direction away from the core 110. Of course, in other embodiments, the core clip may also be a rectangular hollow pipe, that is, the core clip is formed by connecting and enclosing four clip structures of a plate structure to form a closed structure, and the structure makes the structure of the core clip more stable; or the core clip may be formed by connecting and surrounding five, six or more clip members of a plate structure to form a closed structure, which is not limited herein.

The number of the iron core clamping pieces 140 is four, two of the iron core clamping pieces 140 are symmetrically located at two sides of the upper end of the iron core 110, and the upper end (i.e., the upper iron yoke 112) of the iron core 110 is clamped and then fixedly connected through a first fastening piece; the other two core clamps 140 are symmetrically located at both sides of the lower end of the core 110, and are fixedly connected by a second fastening member after clamping the lower end of the core 110 (i.e., the lower yoke 113). The first fastener and the second fastener are screws and bolts used in cooperation with each other to clamp two ends of the core 110 through the two core clamps 140. The two ends of the core clip 140 are both provided with first through holes 141, the two core clips 140 are correspondingly placed on both sides of the upper end of the core 110, screws (not shown) are simultaneously inserted into the two first through holes 141 of the same end of the two core clips 140 and then screwed and fixed by bolts, and both ends of the two core clips 140 are fixed in such a way that the two core clips 140 clamp the upper end of the core 110. The two core clamps 140 at the lower end of the core 110 are also used to fix and clamp the lower end of the core 110 in the same manner, which is not described in detail. In addition, in order to further reliably clamp the iron core 110, the middle portion of the iron core clamp 140 also adopts a plurality of screws and bolts which are used in cooperation with each other to clamp the middle portion of the iron core 110. The core clamp 140 further has a second through hole (not shown) for connecting with the low voltage winding 120.

The core clip 140 is made of a fiber-reinforced composite material, and may be molded by molding glass fiber impregnated epoxy resin, or by molding aramid fiber impregnated epoxy resin, or may be integrally molded by using other composite materials, which is not limited herein.

The fiber reinforced composite material is formed by winding, molding or pultrusion a reinforcing fiber material, such as glass fiber, aramid fiber and the like, and a matrix material.

In other embodiments, the core clip may also be made of a metal material, and may be an integrally formed channel, or may be formed separately and then fixed by welding. At this time, an insulating component such as a small post insulator needs to be connected outside the iron core clamp to insulate the high-low voltage wiring position from the metal channel steel. Simultaneously, also should set up insulating pad outside the iron core, make on the one hand insulating between iron core and the iron core folder, on the other hand avoid producing the vortex on the iron core folder and cause the electromagnetic loss of iron core.

The core clip 140 made of the fiber reinforced composite material in the embodiment has more excellent economic performance compared with the core clip of the traditional channel steel structure, an insulating pad fixed on the outer surface of the core 110 can be omitted, the cost of the fiber reinforced composite material is lower, and the total cost can be reduced by about 60%. Meanwhile, because the traditional channel steel structure is made of a metal conductive material, an additional insulating part such as a small post insulator needs to be connected to the iron core clamp for insulation, so that the cost is increased, the weight of the whole equipment is increased, the noise is high in the operation of the equipment, the carbon emission in the production process of ironwork is large, the pollution is serious, and the iron core clamp 140 made of a fiber reinforced composite material solves the problems; in addition, the core clip 140 made of the fiber reinforced composite material does not generate eddy current loss in the composite body, thereby reducing no-load loss of the dry type transformer 10. In summary, the core clip 140 made of the fiber reinforced composite material has low cost, light weight and good mechanical property, and the carbon emission amount in the production process of the fiber reinforced composite material is low, so that the fiber reinforced composite material is more green and more environment-friendly.

Referring to fig. 2 and 4, the low voltage winding 120 includes a copper foil 121, a low voltage insulating layer 122, and a support bar 123, and the copper foil 121 and the low voltage insulating layer 122 are alternately disposed. Specifically, the copper foil 121 is wound by winding the whole copper foil roll, and the low-voltage insulating layer 122 and the copper foil 121 are overlapped and then wound together, so that the alternating arrangement of the copper foil 121 and the low-voltage insulating layer 122 is realized. At least one heat dissipation air channel is arranged in the low-voltage winding 120 and located between the adjacent copper foil 121 and the low-voltage insulating layer 122, and a support bar 123 is located in the heat dissipation air channel and used for supporting and isolating the adjacent copper foil 121 and the low-voltage insulating layer 122. Specifically, the supporting bar 123 is an insulating supporting bar 123, and when the copper foil 121 and the low-voltage insulating layer 122 are overlapped and wound to a fixed thickness, the insulating supporting bar 123 is fixed on the outer surface of the low-voltage insulating layer 122 or the copper foil 121, and the overlapping and winding are continued to make the copper foil 121 or the low-voltage insulating layer 122 tightly adhere to the insulating supporting bar 123, and the insulating supporting bar 123 may be fixed between the adjacent copper foil 121 and the low-voltage insulating layer 122 by an adhesive method, or may be fixed by a pressing force generated during winding or other methods. Be equipped with a plurality of insulating support bars 123 in every layer of heat dissipation air flue, a plurality of insulating support bars 123 set up along the circumference interval of copper foil 121 outer peripheral face, play the effect of supporting adjacent copper foil 121 and low pressure insulating layer 122 simultaneously. The number of the insulating support bars 123 arranged in each layer of the heat dissipation air channel is at least two, and may be two, three, four or more. Preferably, a plurality of insulation support bars 123 of the same layer are uniformly spaced along the circumferential direction of the outer circumferential surface of the copper foil 121. After the insulating support bars 123 are arranged, the copper foil 121 and the low-voltage insulating layer 122 are continuously wound in an overlapping mode to a preset thickness, and the low-voltage winding 120 is formed. Due to the arrangement of the heat dissipation air channel, heat generated by the low-voltage winding 120 can be released in the operation process of the dry-type transformer 10, and the dry-type transformer 10 is prevented from being overheated and losing efficacy. The heat dissipation air channel may be provided with one layer, or may be provided with two or more layers, which is not limited herein.

The low-voltage insulating layer 122 is made of polyimide impregnated paper, specifically SHS-P diphenyl ether prepreg, and is formed by baking after impregnating a polyimide film and polysulfone fiber non-woven fabric soft composite material with diphenyl ether resin, or is made of DMD insulating paper or silicone rubber film, or other insulating materials, and is selected according to different temperature rise grades of the dry-type transformer.

The insulating support bar 123 is made of glass fiber-impregnated epoxy resin, or made of aramid fiber-impregnated epoxy resin, which is not limited herein. Moreover, the insulating support bars 123 are long strips with h-shaped sections, so that the mechanical strength is more stable. Of course, the insulating support bars may also be long bars with square or other shapes in cross section, as long as the function of supporting and isolating is achieved.

As shown in fig. 5-10, the high voltage winding 130 includes a bobbin 1310, a high voltage coil 1320, and a high voltage insulation layer 1330, with a wire wound around the bobbin 1310 to form the high voltage coil 1320. Specifically, the winding body 1310 includes a supporting cylinder 1311 and a winding portion 1312, where the supporting cylinder 1311 is a hollow cylinder, and may be a hollow cylinder, a hollow elliptic cylinder, or another hollow cylinder; the winding portion 1312 is located on an outer circumferential surface of the support tube 1311, a wire is wound in the winding portion 1312 to form a high voltage coil 1320, and the high voltage coil 1320 includes a plurality of segments of coils arranged at intervals in an axial direction of the support tube 1311.

Specifically, the winding portion 1312 includes a plurality of winding plates 1313, the plurality of winding plates 1313 are circumferentially and uniformly distributed on the outer circumferential surface of the support cylinder 1311, each winding plate 1313 is disposed along the axial direction of the support cylinder 1311, and the axial length of the winding plate 1313 along the support cylinder 1311 is smaller than the axial length of the support cylinder 1311 along the axial direction thereof. The number of the winding boards 1313 is at least two, that is, two, three, four or more, which is not limited herein. In order to make the wire winding reliable and save material as much as possible, the number of the winding plates 1313 of the 10kV/1000kVA dry type transformer is twelve. In other embodiments, the length of the wire winding plate in the axial direction of the support cylinder may also be equal to the length of the support cylinder in the axial direction thereof.

The winding board 1313 is a rectangular board, the longer side of the winding board 1313 is disposed along the axial direction of the supporting cylinder 1311, a plurality of winding slots 1314 are further disposed on the winding board 1313, the plurality of winding slots 1314 are disposed along the radial direction of the supporting cylinder 1311 and are distributed along the axial direction of the supporting cylinder 1311 at intervals, so that the winding board 1313 is in a comb shape, that is, a plurality of comb teeth are formed on the winding board 1313. The height of the comb teeth on the winding board 1313 along the axial direction of the support cylinder 1311 is defined as the tooth height, the tooth height of the comb teeth at the two ends of the winding board 1313 and the tooth height of the comb teeth in the middle of the winding board 1313 are both greater than those of the comb teeth at the other parts, because the field intensity at the end part of the high-voltage coil 1320 is not uniform, the tooth heights at the two ends of the winding board 1313 are set to be larger than those of the comb teeth at the other parts, a tap of a branch line needs to be led out from the middle of the winding board 1313, the tooth height in the middle of the winding board 1313 is set to be larger than that of the high-voltage coil 1320, the distance between the two corresponding adjacent winding slots 1314 is larger, and a placement space can be reserved for the tap led out from the middle of the winding board 1313. Meanwhile, a comb tooth area with a slightly large tooth height is defined as a high comb tooth area, and a comb tooth area with a slightly small tooth height is defined as a low comb tooth area. Then, through the above arrangement, the winding board 1313 sequentially forms a first high comb tooth area, a first low comb tooth area, a second high comb tooth area, a second low comb tooth area, and a third high comb tooth area from one end toward the other end in the axial direction of the supporting cylinder 1311. Further, the tooth heights of the first high comb-tooth region, the second high comb-tooth region and the third high comb-tooth region are not particularly limited, and may be, for example, the same as each other or may be different from each other. And the first high comb tooth area and the third high comb tooth area can be symmetrically arranged relative to the second high comb tooth area, and the first low comb tooth area and the second low comb tooth area can also be symmetrically arranged relative to the second high comb tooth area. Of course, the arrangement may be asymmetrical, and is not limited herein.

At least one section of coil is arranged between two adjacent comb teeth on the winding board 1313, so that a wire is wound in each winding slot 1314, high-voltage coils 1320 are reasonably distributed and arranged, and the coils of all sections are arranged at intervals.

When the plurality of winding plates 1313 are uniformly distributed on the outer circumferential surface of the supporting cylinder 1311 in the circumferential direction, two ends of all the winding plates 1313 are arranged in a flush manner, the winding grooves 1314 on all the winding plates 1313 are matched in a one-to-one correspondence manner in the circumferential direction of the supporting cylinder 1311, each section of coil is wound in a corresponding circle of winding groove 1314 on all the winding plates 1313 along the circumferential direction of the supporting cylinder 1311 by a conducting wire, and the supporting cylinder 1311 is balanced in stress and good in mechanical strength.

In other embodiments, in order to set the positions of the taps away, the plurality of winding boards may also be fixed on the outer circumferential surface of the supporting cylinder in an uneven arrangement manner, that is, the distance between two adjacent winding boards is not equal, for example, the distance between two adjacent winding boards is greater than the distance between any two other adjacent winding boards, at this time, each tap is led out from between the two adjacent winding boards, so that the tooth height of the comb teeth in the middle of the winding boards does not need to be set to be larger, and the setting position of each tap can also be reserved.

In other embodiments, the wire winding plate may also be an annular disc disposed circumferentially around the support cylinder. The plurality of winding plates are arranged at intervals along the axial direction of the supporting cylinder, and the conducting wire is wound in the groove formed by the two adjacent winding plates.

The support cylinder 1311 is a hollow pipe formed by winding, curing, or pultrusion of glass fiber-impregnated epoxy resin, or a hollow pipe formed by winding, pultrusion, or pultrusion of glass fiber-impregnated epoxy resin, or a hollow pipe formed by winding, curing, or pultrusion of aramid fiber-impregnated epoxy resin, or is made of other composite materials, which is not limited herein.

In an application scene, the supporting cylinder 1311 and the winding board 1313 are formed separately and then are bonded and fixed. Specifically, the winding board 1313 is also made of glass fiber impregnated epoxy resin, multiple layers of glass fiber cloth are impregnated with epoxy resin and then stacked to form a certain thickness, the glass fiber cloth is molded and cured to form a rectangular glass fiber reinforced plastic plate, a winding groove 1314 is formed in the glass fiber reinforced plastic plate, the winding groove 1314 can be formed by turning, and therefore the winding board 1313 is formed, the winding board 1313 is fixedly connected to the outer peripheral surface of the supporting cylinder 1311 through adhesive, materials are saved, and cost can be saved. The adhesive is a two-component high temperature resistant epoxy adhesive, which may be other adhesives, but it is required to ensure that the adhesive can firmly bond the supporting cylinder 1311 and the winding board 1313, and is high temperature resistant so as to adapt to the high temperature injection high pressure insulation layer 1330 outside the winding body 1310.

In this embodiment, the winding board 1313 is molded and cured, and in other embodiments, the comb-shaped winding board may be directly molded by integral casting and curing, so as to simplify the process, and the material of the winding board is the same as that described above, and thus the description thereof is omitted.

In another application scenario, the support tube 1311 is integrally formed with the wire spool 1313. A hollow pipe with a large thickness is formed by pultrusion or winding glass fiber or aramid fiber impregnated epoxy resin, and then the hollow pipe is turned, so that the supporting cylinder 1311 and the winding board 1313 are formed, the material is wasted, the strength between the supporting cylinder 1311 and the winding board 1313 can be guaranteed, and the connection between the supporting cylinder 1311 and the winding board 1313 is prevented from being damaged due to the fact that the high-pressure insulating layer 1330 is not firmly bonded or in the subsequent process of injecting the high-pressure insulating layer 1330.

In still another application scenario, as shown in fig. 5 and 6 in combination, the winding body 1310 further includes two flanges 1315, specifically, the flanges 1315 are located at two ends of the supporting cylinder 1311 and extend outward in a radial direction of the supporting cylinder 1311 to form an annular disc surface, the flanges 1315 at the two ends are disposed opposite to each other, when the winding board 1313 is disposed at an outer circumferential surface of the winding body 1310, outer end surfaces of the two ends of the winding board 1313 abut against the disc surface where the two flanges 1315 face each other, so as to prevent the winding board 1313 from being damaged due to a large injection pressure during the injection of the high-pressure insulating layer 1330. Of course, the outer end surfaces of the two ends of the winding plate 1313 may not abut against the disc surfaces of the two flanges 1315 facing each other, that is, a gap may be left between the outer end surfaces of the two ends of the winding plate 1313 and the disc surfaces of the flanges 1315 facing the winding plate 1313, which is not limited herein.

The flange 1315 is made of glass fiber impregnated epoxy resin, and is integrally formed with the support barrel 1311, that is, formed by pultrusion or winding of glass fiber or aramid fiber impregnated epoxy resin, and then is machined and polished into a disk piece with a certain thickness.

In other embodiments, the winding body may also include only the winding portion, the rigid insulation lining cylinder, that is, the supporting cylinder, is not provided, the winding portion is circumferentially disposed inside the high-voltage winding, the conducting wire is wound outside the winding portion to form the high-voltage coil, and the high-voltage insulation layer wraps the high-voltage coil and the winding portion. The high-voltage winding omits a structure of a rigid insulating lining barrel, so that the heat conduction effect is better, an interface between a high-voltage insulating layer and the rigid insulating lining barrel is eliminated, the surface discharge of the rigid insulating lining barrel is inhibited, the material is saved, and the cost is reduced.

The winding body 1310 is made of the fiber reinforced composite material, has the characteristics of light weight and high strength, so that the winding body 1310 has better mechanical strength, can effectively support the winding of a lead, is not easy to damage, and avoids the lead from being scattered and displaced by the injection impact force generated when high-temperature vulcanized silicone rubber is injected outside the winding body 1310; and the fiber reinforced composite material has good heat resistance, and prevents the deformation of the winding 1310 caused by the excessive heat generated by the high-voltage coil 1320 during the operation of the dry-type transformer 10.

Referring to fig. 5, 7 and 8, taking the phase a transformer 100 as an example, a wire is wound around the outer circumferential surface of the winding body 1310 in the circumferential direction to form the high voltage coil 1320. Specifically, the wire is wound in the winding slot 1314 of the winding portion 1312, so that the high-voltage coil 1320 is spaced apart from the supporting cylinder 1311 in the axial direction, and the wire forms two external connections, namely a first external connection D and a second external connection X, at the end and the end after winding, the first external connection D is used for connecting a cable, and the second external connection X is used for connecting other external connections, such as in a three-phase transformer, for connecting with each other between the phase transformers. And, the conductive wire is led out at the middle of the bobbin 1310 in the axial direction thereof with six taps, respectively, tap 2, tap 3, tap 4, tap 5, tap 6, and tap 7, the six taps forming a tap switch, and for convenience of description, tap 2, tap 4, and tap 6 are defined as a first tap switch, and tap 3, tap 5, and tap 7 are defined as a second tap switch.

In an application scenario, as shown in fig. 5, 7 and 10, the wires include a first wire and a second wire, both the first wire and the second wire are continuous wires, and both the first wire and the second wire are covered with an insulating layer, the insulating layer may be a polyimide film or a glass fiber film, or the insulating layer is another insulating material such as polyester paint, or may be a combination of multiple insulating materials, which is not limited herein. The first conductive wire is wound from one end of the winding portion 1312 to the middle of the winding portion 1312 in the axial direction of the support tube 1311, and three taps are drawn. For convenience, the upper end of the winding portion 1312 is defined as a first end, the lower end of the winding portion 1312 is defined as a second end, the first wire is wound from the first end of the winding portion 1312 to the second end of the winding portion 1312, the first wire is wound in a first winding slot 1314 of a corresponding turn on all winding plates 1313 to form a first coil segment 1321, the first coil segment 1321 is pie-wound, and only one pie coil is disposed in each winding slot 1314, and at this time, only one pie coil is disposed in each coil segment. The inner turn lead end of the first lead at the first end of the winding portion 1312 forms a first external connection D exposed outside the high voltage insulation layer 1330, that is, the first external connection D is led out from the inner turn lead end of the first coil 1321 (i.e., the head end of the first lead), the outer turn lead end of the first coil 1321 extends into a corresponding circle of second winding groove 1314 on all the winding plates 1313 to continue to be wound to form a second coil 1322, and so on until the first lead is wound to the middle of the winding body 1310, and three taps, that is, a tap 6, a tap 4 and a tap 2 shown in fig. 10, are led out from the outer turn lead ends of three coils respectively, so that the first lead is wound.

A second conductive wire is wound from the middle of the winding portion 1312 to the second end of the winding portion 1312 in the axial direction of the support tube 1311, and led out of the other three taps. Specifically, the second wire starts to be wound in the winding slot 1314 of the next turn adjacent to the tap 2 to form a third-stage coil 1323, the second wire continues to be wound toward the second end of the winding portion 1312 in the same winding manner as the first wire, and three other taps, i.e., tap 3, tap 5 and tap 7, respectively, are led out from the three-stage coil in which the third-stage coil 1323 starts until the second wire is wound to the last winding slot 1314 of the corresponding turn on each winding plate 1313 at the second end of the winding portion 1312 to form a terminal-stage coil 1324. The outer turn end of the second wire at the second end of the winding portion 1312 forms a second outer connection X exposed outside the high voltage insulating layer 1330, that is, the second outer connection X is led out from the outer turn end of the terminal-section coil 1324 (i.e., the end of the second wire), so that the second wire is wound.

When the conducting wire is wound, the conducting wire is wound in the corresponding winding grooves 1314 on all the winding plates 1313, so that each section of coil formed by winding the conducting wire is perpendicular to the axial direction of the supporting cylinder 1311, the winding is convenient, the conducting wire is arranged neatly, the stress of the winding plates 1313 and the supporting cylinder 1311 is uniform, and the mechanical strength is good.

Thus, a pancake high-voltage coil 1320 is formed, which has a high mechanical strength, a high ability to withstand the electromotive force generated by the short-circuit current, a large number of pancake coils, and a high heat dissipation ability as compared with a layered coil. In the axial direction of the supporting cylinder 1311, as shown in fig. 8 and 10, the tap 6, the tap 4, and the tap 2 are sequentially distributed to form a first tap changer, the tap 3, the tap 5, and the tap 7 are sequentially distributed to form a second tap changer, the first tap changer and the second tap changer are arranged in parallel, and the six taps form tapping devices of the high-voltage coil 1320, which are used for the dry-type transformer 10 to adjust voltage according to different operating conditions.

The high voltage coil 1320 is wound around the winding 1310 to form a high voltage coil 1320, and the high voltage coil 1320 is annular, and the annular width of the high voltage coil 1320 is defined as the width of the high voltage coil 1320, so that the widths of the high voltage coil 1320 in all radial sections are the same, that is, the outer side surface of the high voltage coil 1320 is equidistant from the outer circumferential surface of the supporting cylinder 1311, and the high voltage coil 1320 is stressed in a balanced manner. Of course, in consideration of actual operation, the widths of the coils in the radial cross section may not be exactly the same, as long as they are substantially the same.

In this embodiment, the second conductive wire is wound from the winding groove 1314 of the next turn adjacent to the tap 2 to the winding groove 1314 of the last turn at the second end of the winding portion 1312, and in other embodiments, the second conductive wire may be wound from the winding groove of the last turn at the second end of the winding portion up to the winding groove of the next turn adjacent to the tap 2, but the second external connection X is formed first, and then the tap 7, the tap 5 and the tap 3 are sequentially formed. Of course, the winding method of the high voltage coil 1320 is not limited to the above method, and a pancake coil or a layer coil may be formed in other methods as long as the high voltage coil 130 can be finally formed.

In this embodiment, the tap changer includes six taps, and the dry-type transformer 10 has five adjustable voltage levels, in other embodiments, the tap changer may also include four taps, that is, the first tap changer and the second tap changer include two taps, and the dry-type transformer includes three adjustable voltage levels, as long as the actual use requirements of the dry-type transformer are met, which is not limited herein.

As shown in fig. 7-9, a high voltage insulation 1330 surrounds the high voltage coil 1320 and the bobbin 1310 to form the high voltage winding 130. The high-voltage insulating layer 1330 is made of high-temperature vulcanized silicone rubber, specifically, a conducting wire is wound on the winding 1310 to form the high-voltage coil 1320, the winding 1310 and the high-voltage coil 1320 are used as a body to be injected, the body to be injected is placed into a mold of an injection machine, and the high-temperature vulcanized silicone rubber is injected integrally on the periphery of the body to be injected by adding silicone rubber raw materials to obtain the high-voltage winding 130. The high voltage insulation 1330 is made of high temperature vulcanized silicone rubber, which improves the insulation and mechanical properties of the high voltage winding 130 as a whole.

After the high-voltage coil 1320 and the winding 1310 are coated by the integral vacuum injection high-temperature vulcanized silicone rubber, the high-temperature vulcanized silicone rubber fills the gap between the high-voltage coil 1320 and the winding 1310 and coats the two ends of the winding 1310, and the inner wall of the supporting cylinder 1311 is not coated by the high-temperature vulcanized silicone rubber, so that the high-voltage winding 130 is integrally in a hollow column shape, can be a hollow cylinder, can also be a hollow elliptic cylinder, or other hollow columns.

Before the high-temperature vulcanized silicone rubber is integrally injected, the six taps are connected by arranging the tool connecting piece 101, so that the problem that the six taps cannot be used for wiring due to the fact that the six taps are also coated by the silicone rubber in the injection process is avoided. As shown in fig. 9, the tooling connecting member 101 is an aluminum alloy plate, a protection cavity is provided on the plate surface of the tooling connecting member 101, and the tap is fixed in the protection cavity. In this application, the protection cavity is six identical stepped holes 1011, and the inner walls of the stepped holes 1011 are further provided with threads. The six taps are respectively connected to the six stepped holes 1011, and may be connected by welding or may be fixedly connected by other methods, which is not limited herein. Furthermore, six step holes 1011 on the tool connecting piece 101 are arranged in two parallel rows, and three step holes 1011 are arranged in each row, so that the first tapping switch and the second tapping switch are also arranged in parallel. Meanwhile, before the integral injection, the six taps are respectively connected to the six step holes 1011, and then the bolts are connected in the six step holes 1011, so that the bolts can directly fill the residual space of the step holes 1011, the six step holes 1011 are prevented from being filled with silicon rubber, and the six taps are prevented from being coated with the silicon rubber and then cannot be used for wiring.

Two opposite side surfaces of the tool connecting piece 101 are also provided with two symmetrical connecting grooves 1012, two connecting blocks are correspondingly arranged in the injection mold, when the tool connecting piece 101 is arranged in the injection mold, the two connecting grooves 1012 on the tool connecting piece are respectively clamped and connected with the two connecting blocks on the injection mold, so that the tool connecting piece 101 is fixed in the injection mold, and the tool connecting piece 101 is prevented from being shifted due to larger injection pressure in the process of injecting silicon rubber.

In other embodiments, two symmetrical connecting blocks may be arranged on two opposite side surfaces of the tool connecting part, two connecting grooves are correspondingly arranged in the injection mold, and when the tool connecting part is arranged in the injection mold, the two connecting blocks on the tool connecting part are respectively clamped and connected with the two connecting grooves on the injection mold, so that the tool connecting part is fixed in the injection mold, and the tool connecting part is prevented from being shifted due to larger injection pressure in the process of injecting the silicon rubber. After the high voltage insulation layer 1330 is formed by integral injection, the side surface of the tooling connection piece 101 is coated with a small amount of silicon rubber, and because the amount of the silicon rubber coated on the tooling connection piece 101 is small, the tooling connection piece 101 can be directly disassembled by a tool to expose the first tap switch and the second tap switch, and finally the high voltage winding 130 shown in fig. 8 is formed.

In this embodiment, the number of the tool connecting pieces 101 is one, in other embodiments, two tool connecting pieces may be provided, the size of the tool connecting piece at this time is set to be smaller, three step holes are formed in each tool connecting piece, and six taps are connected to the six step holes, respectively, which is not limited herein.

In the present embodiment, as shown in fig. 11, the high-voltage winding 130 coated with the high-voltage insulating layer 1330 is a partial cross-sectional view cut along the axial direction thereof, the wire is wound in the comb-teeth-shaped winding plate 1313 by the aforementioned winding method to form the pancake high-voltage coil 1320, and the pancake high-voltage coil 1320 and the comb teeth of the winding plate 1313 are arranged at an interval in the axial direction of the high-voltage winding 130, that is, a pancake coil is arranged between two adjacent comb teeth.

In another embodiment, as shown in fig. 12, which is a partial sectional view of the high voltage winding 230 coated with the high voltage insulating layer 2330, cut along its axial direction, a wire is wound on the comb-shaped winding plate 2313 by a double winding continuous winding method to form the high voltage coil 2320. After two identical continuous leads are arranged adjacently, winding is started from a circle of winding grooves 2314 corresponding to the upper ends of all the winding plates 2313 at the same time, a first section of coil 2321 is formed, the first section of coil 2321 comprises two pancake coils which are arranged adjacently along the axial direction of the supporting cylinder 2311, the specific winding method is consistent with that of the high-voltage coil 1320, downward winding is performed by analogy in sequence, a second section of coil 2322 and other coils are continuously formed until the high-voltage coils 2320 which are arranged at intervals along the axial direction of the high-voltage winding 230 are formed, each section of coil comprises two pancake coils which are arranged adjacently, the length of each section of coil along the axial direction of the winding plates 2313 is equal to the sum of the widths of the two parallel leads along the axial direction of the supporting cylinder 2311, and two pancake coils are arranged between two adjacent comb teeth on the winding plates 2313. The two same wires mean that the two wires are identical in size and material. Compared with a continuous winding structure of a single wire (namely the structure of the high-voltage coil 1320), the number of the winding grooves 2314 can be reduced in the high-voltage winding with the same size, so that the wire transition section between the interval sections of each section of the coil is reduced, the using amount of the wire is reduced, and the purpose of reducing the cost is achieved. In other embodiments, three pie coils or more pie coils can be arranged between two adjacent comb teeth on the winding plate.

In still another embodiment, as shown in fig. 13, which is a partial sectional view of the high voltage winding 330 coated with the high voltage insulating layer 3330 taken along an axial direction thereof, a width of the winding grooves 3314 of the winding plate 3313 in the axial direction of the support cylinder 3311 is greater than a width of the winding grooves 2314 of the winding plate 2313 in the axial direction of the support cylinder 2311. The wire is wound layer-wise to form a first coil section 3321, specifically, a continuous wire is used, and the first coil section 3321 is wound in a circle of first winding slots 3314 corresponding to the upper ends of all the winding plates 3313, and is wound downward along the axial direction of the supporting barrel 3311 at the upper end of the first winding slot 3314 until the wire is wound to the lower end of the first winding slot 3314 to form a first coil layer, the wire of the first coil layer is wound in a spiral shape closely arranged on the outer circumference of the supporting barrel 3311, after the wire is wound in the first coil layer, the second coil layer is wound upward from the lower end of the first winding slot 3314 in the axial direction of the supporting barrel 3311, and the winding is repeated until the first coil section 3321 reaches the preset width of the high-voltage coil 3320 in the radial direction of the supporting barrel 3311, and finally the first coil section 3321 is wound in a spiral shape closely arranged on the outer circumference of the supporting barrel 3311. Then, the wire is transited to the second winding slot 3314 through the comb teeth of the winding plate 3313, and the winding is continued according to the layer winding method to form a second section of coil 3322, and so on, and the winding is continued until the winding of the wire in all the winding slots 3314 is completed, thereby finally forming the high voltage coil 3320.

Because the winding slots 3314 have a larger axial width along the supporting tube 3311, each segment of coil is spirally arranged along the axial direction of the winding plate 3313, and the length of each segment of coil along the axial direction of the winding plate 3313 is greater than the sum of the widths of two parallel wires, so as to form a multi-segment cylindrical high-voltage coil 3320, compared with a pancake structure (i.e., the structure of the high-voltage coil 2320) wound by adopting a double-winding continuous winding method, in the high-voltage winding with the same specification, the high-voltage coil 3320 is more compact, the number of the winding slots 3314 is less, the number of wires is less, and the purpose of reducing the cost is further achieved.

In this embodiment, the comb teeth are provided between the first-stage coil 3321 and the second-stage coil 3322 by providing the wire winding plate 3313, but in other embodiments, the wire winding plate may not be provided, and a gap may be left between the first-stage coil and the second-stage coil, and finally the high-voltage coil is fixed by filling the high-voltage insulating layer, thereby achieving the purpose of insulating the high-voltage coil between the stages.

In another embodiment, as shown in fig. 14, which is a partial cross-sectional view of a high-voltage winding 430 covered with a high-voltage insulation layer 4330 taken along an axial direction thereof, a forming manner of a high-voltage coil 4320 is the same as that of the high-voltage coil 3320, and is not described again. However, the length of each segment of the high-voltage coil 4320 in the axial direction of the support cylinder 4311 is greater than that of each segment of the high-voltage coil 3320 in the axial direction of the support cylinder 3311, and the dry-type transformer 10 of the same voltage class has fewer segments of the segmented cylindrical high-voltage coil 4320. Because the length of each section of coil of the high-voltage coil 4320 along the axial direction of the support cylinder 4311 is larger, the voltage difference between each section of coil is larger, and therefore an insulating layer needs to be added between layers of each section of coil to reduce the voltage difference, at this time, the interlayer insulating layer 4301 is arranged on each section of coil along the axial direction of the high-voltage winding 430, so that the electric field intensity between layers is prevented from being higher than the tolerance critical value of the insulating film coated by the insulating wire. And moreover, the layered structure in each section of coil has good lightning impulse resistance, and the economic advantage is more obvious. Specifically, when the wire is wound to a certain thickness by a layer winding method, the wire is continuously wound after the interlayer insulating layer 4301 is placed at a corresponding position, and the interlayer insulating layer 4301 is arranged in each coil.

The interlayer insulating layer 4301 may be a mesh cloth, insulating support bars arranged circumferentially at intervals, or other hard insulating materials. And the insulating supporting strip is an insulating strip with a wavy edge, so that the insulating supporting strip can be prevented from being damaged due to extremely high injection pressure when high-temperature vulcanized silicone rubber is injected to form a high-voltage insulating layer. And the insulating support strip is made of hard insulating materials and can resist the impact force of silicon rubber during high-temperature injection. Meanwhile, the interlayer insulating layer 4301 may be provided as one layer, or may be provided as two or three layers, depending on different design conditions, which is not limited herein.

In another embodiment, with reference to fig. 1-11, a method of manufacturing a high voltage winding 130 is provided, comprising the steps of:

the method comprises the following steps: the wire is wound circumferentially along the outer circumferential surface of the winding body 1310 to form a high voltage coil 1320, and a tap is formed during the winding process of the wire.

First, the winding body 1310 includes a supporting cylinder 1311 and a winding portion 1312 located on the outer circumferential surface of the supporting cylinder 1311, wherein the supporting cylinder 1311 is a hollow cylinder, a hollow elliptic cylinder, or other hollow cylinders; the winding portion 1312 includes a plurality of winding plates 1313, the plurality of winding plates 1313 are disposed along the axial direction of the support tube 1311 and are circumferentially and uniformly distributed on the outer circumferential surface of the support tube 1311, and the number of the winding plates 1313 is at least two, that is, two, three, four or more, which is not limited herein. In order to make the wire winding reliable and save material as much as possible, the number of the winding plates 1313 of the 10kV/1000kVA dry type transformer is twelve. The winding plate 1313 is further provided with a plurality of winding slots 1314, and the winding slots 1314 are arranged along the radial direction of the supporting cylinder 1311 and are distributed at intervals along the axial direction of the supporting cylinder 1311, so that the winding plate 1313 is in a comb shape.

The specific structure, material, forming method, etc. of the supporting tube 1311 and the winding board 1313 are as described above, and are not described in detail.

Next, the winding body 1310 is wound on a winding device, and a high voltage coil 1320 is formed by winding a wire around the winding body 1310, such that the high voltage coil 1320 is arranged at intervals along an axial direction of the support cylinder 1311, thereby forming a pancake type high voltage coil 1320. The wire winding method and the structure of the high voltage coil 1320 are the same as those described above, and will not be described again. And the conducting wires are led out of the tap 2, the tap 3, the tap 4, the tap 5, the tap 6 and the tap 7 respectively in the winding process, so that the tap switch is formed.

In this embodiment, the wire is wound to form a pancake high-voltage coil 1320, and in other embodiments, the wire may also be wound to form a double-winding continuous high-voltage coil 2320, a multi-segment cylindrical high-voltage coil 3320 and a segmented cylindrical high-voltage coil 4320 as shown in fig. 12 to 14, which are not described in detail herein. Furthermore, the tap changer may also include only four taps, which is not limited herein.

Step two: the tap is placed in the protection cavity of the tooling connection piece 101 and is fixedly connected with the tooling connection piece 101.

Through the tool connecting part 101 shown in fig. 9, six taps are respectively connected and fixed to the protection cavity of the tool connecting part 101, in this application, the protection cavity is six step holes 1011, and may be connected by welding or may be fixedly connected by other methods, which is not limited herein.

Step three: the winding body 1310 wound with the high-voltage coil 1320 is placed in a mold of an injection machine as a body to be injected, and high-temperature vulcanized silicone rubber is injected at the periphery of the body to be injected, so that the high-voltage coil 1320 and the winding body 1310 are coated by the high-temperature vulcanized silicone rubber.

Before the step, bolts are connected in the six step holes 1011 of the tool connecting piece 101, so that the bolts can directly fill the residual space of the step holes 1011, the six step holes 1011 are prevented from being filled with silicon rubber, and the situation that the six taps cannot be used for wiring after being coated with the silicon rubber can be avoided.

The winding body 1310 and the high-voltage coil 1320 connected with the tool connecting piece 101 are used as a body to be injected, then after a coupling agent is coated on the periphery of the body to be injected, the body to be injected is placed into a mold of an injection machine, a silicon rubber raw material is added, high-temperature vulcanized silicon rubber is integrally injected on the periphery of the body to be injected, and after cooling, the high-voltage winding 130 is obtained, and the high-voltage insulating layer 1330 of the high-temperature vulcanized silicon rubber integrally improves the insulating property and the mechanical property of the high-voltage winding 130.

Two opposite side surfaces of the tool connecting piece 101 are also provided with two symmetrical connecting grooves 1012, two connecting blocks are correspondingly arranged in the injection mould, when an injection body is placed into the mould of the injection machine, the two connecting grooves 1012 on the tool connecting piece 101 are respectively clamped and connected with the two connecting blocks on the injection mould, so that the tool connecting piece 101 is fixed in the injection mould, and the tool connecting piece 101 is prevented from being shifted due to larger injection pressure in the process of injecting silicon rubber. Of course, two symmetrical connecting blocks may be arranged on two opposite side surfaces of the tool connecting member, two connecting grooves are correspondingly arranged in the injection mold, and the connecting blocks on the tool connecting member and the connecting grooves on the injection mold are also connected in a matching manner, which is not described in detail.

After the high-temperature vulcanized silicone rubber is coated on the high-voltage coil 1320 and the winding body 1310 through integral vacuum injection, the high-temperature vulcanized silicone rubber fills the gap between the high-voltage coil 1320 and the winding body 1310 and the two ends of the winding body 1310, and the high-temperature vulcanized silicone rubber does not coat the inner wall of the supporting cylinder 1311, so that the high-voltage winding 130 is integrally hollow cylindrical, can be a hollow cylinder, can also be a hollow elliptic cylinder, or other hollow cylindrical bodies.

Step IV: the tooling connection 101 is removed resulting in the high voltage winding 130 with the tap exposed to the high temperature vulcanized silicone rubber.

After the high voltage insulation layer 1330 is formed by vacuum injection, the side surface of the tooling connection piece 101 is coated with a small amount of silicon rubber, and because the amount of silicon rubber coated on the tooling connection piece 101 is small, the tooling connection piece 101 can be directly removed by a tool to expose the tap, and finally the high voltage winding 130 shown in fig. 8 is formed.

In another embodiment, as shown in fig. 1-4, a dry-type transformer 10 is provided, the dry-type transformer 10 being a three-phase transformer, a phase, B phase and C phase, respectively, the dry-type transformer 10 including an iron core 110, three low voltage windings 120 and three high voltage windings 130. The iron core 110 includes three columnar iron core bodies 111, an upper iron yoke 112 located at the upper ends of the three columnar iron core bodies 111, and a lower iron yoke 113 located at the lower ends of the three columnar iron core bodies 111, the three low-voltage windings 120 are respectively sleeved on the peripheries of the three columnar iron core bodies 111, and the three high-voltage windings 130 are respectively sleeved on the peripheries of the three low-voltage windings 120.

The beneficial effect of this application is: be different from prior art's condition, the high-voltage winding of this application includes the high-pressure insulating layer of bobbin, high-pressure coil and high temperature vulcanize silicon rubber, compares the epoxy high-pressure insulating layer among the prior art, and the silicon rubber possesses following advantage: 1) the dry-type transformer has better fireproof performance, low-temperature resistance, aging resistance and short-circuit resistance test capability, and can prolong the service life of the dry-type transformer; 2) the copper coil is easy to strip from the silicon rubber, the material recovery rate is more than 99 percent, and the copper coil is more environment-friendly; 3) the silicon rubber elastomer can weaken partial discharge inducement caused by mechanical vibration and has an inhibiting effect on equipment discharge, and the product of the silicon rubber under the discharge action is non-conductive silicon dioxide, so that the continuous degradation of insulation can be effectively inhibited; 4) the running loss of the transformer can be reduced, and energy is saved; 5) the environment resistance is good, and the device can be installed indoors and outdoors. Meanwhile, the silicon rubber is formed by integral high-temperature vulcanization injection molding, and compared with the existing room-temperature vulcanization, the process method enables the high-voltage insulating layer to be more stable, has higher mechanical property and better bonding property with the high-voltage coil and the winding body, and can effectively prolong the service life of the high-voltage insulating layer. Compared with liquid silicon rubber, the high-temperature vulcanized silicone rubber filler is uniformly dispersed, and the dry-type transformer cannot generate partial discharge due to filler agglomeration, so that the overall performance of the dry-type transformer is better.

While the specification and features of the present application have been described above, it will be understood that various changes and modifications in the above-described constructions and materials, including combinations of features disclosed herein either individually or in any combination, will be apparent to those skilled in the art upon studying the disclosure. Such variations and/or combinations are within the skill of the art to which this application pertains and are within the scope of the claims of this application.

Claims

1. A preparation method of a high-voltage winding comprises the following steps:

step two: placing the tap joint in a protection cavity of a tool connecting piece and connecting and fixing the tap joint with the tool connecting piece;

step three: placing the winding body wound with the high-voltage coil as a body to be injected into a mold of an injection machine, and injecting high-temperature vulcanized silicone rubber at the periphery of the body to be injected so that the high-voltage coil and the winding body are coated by the high-temperature vulcanized silicone rubber;

2. The method for preparing a high-voltage winding according to claim 1, wherein the winding body comprises a supporting cylinder and a winding portion on an outer circumferential surface of the supporting cylinder, and in the step (r), the high-voltage coil is formed by winding the wire on the winding portion.

3. The method for preparing a high-voltage winding according to claim 2, wherein in the step (r), the conductive wire comprises a first conductive wire and a second conductive wire, the first conductive wire is wound from a first end of the winding portion to a middle portion of the winding portion along the axial direction of the supporting cylinder and leads out three taps, and the second conductive wire is wound from the middle portion of the winding portion to a second end of the winding portion along the axial direction of the supporting cylinder and leads out three other taps.

4. The method for preparing a high-voltage winding according to claim 1, wherein in the step (II), the protection cavity is a stepped hole, and the tap is welded in the stepped hole.

5. The method for preparing a high-voltage winding according to claim 4, wherein the inner wall of the stepped hole is provided with threads, and a bolt is connected in the stepped hole before the step three.

6. The method for preparing a high-voltage winding according to claim 2, wherein before the step (r), the supporting cylinder and the winding part are made of glass fiber impregnated with epoxy resin.

7. The method for preparing a high-voltage winding according to claim 2, wherein the winding portion includes a plurality of winding plates, and the plurality of winding plates are circumferentially, uniformly and adhesively fixed to the outer circumferential surface of the support cylinder before the first step.

8. The method for preparing a high-voltage winding according to claim 7, wherein before the step (r), a plurality of winding grooves are formed in the winding plate, so that a plurality of comb teeth are formed on the winding plate.

9. The method for preparing a high voltage winding according to claim 1, wherein in the third step, the high temperature vulcanized silicone rubber covers the high voltage coil and the winding body by integral vacuum injection and fills a gap between the high voltage coil and the winding body and both ends of the winding body.

10. A high voltage winding, characterized in that it is manufactured by a method for manufacturing a high voltage winding according to any of claims 1-9.