CN114300254A

CN114300254A - Preparation method of high-voltage winding

Info

Publication number: CN114300254A
Application number: CN202111644257.7A
Authority: CN
Inventors: 马婷婷; 张鑫鑫; 孙名伟; 张小容; 刘超; 马斌
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

Abstract

The application discloses a preparation method of a high-voltage winding, which comprises the following steps: step a: sticking a high-temperature resistant film on the peripheral surface of the winding tool; step b: fixing the winding part and the auxiliary piece on the high-temperature-resistant film, and enabling the auxiliary piece to stably clamp and fix the winding part; step c: winding a lead on the winding part to form a high-voltage coil with a tap switch; step d: placing the winding part wound with the high-voltage coil and the winding tool into an injection machine, and injecting high-temperature vulcanized silicone rubber to form a high-voltage insulating layer to obtain a high-voltage winding; step e: and (6) demolding. The preparation method of the high-voltage winding is simple in steps, the required preparation tool is simple in structure and easy to prepare, and the high-voltage winding prepared by the method omits a rigid insulating lining cylinder structure, so that the heat conduction effect of the high-voltage winding is better, an interface between a high-voltage insulating layer and the rigid insulating lining cylinder does not exist, the surface discharge condition of the rigid insulating lining cylinder does not exist, the material is saved, and the cost is reduced.

Description

Preparation method of high-voltage winding

Technical Field

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

Background

The traditional dry type transformer high-voltage winding framework is composed of a rigid insulation lining cylinder, a rigid insulation winding slot and a cake type winding (or called a coil cake) with an insulation film wire, wherein the framework is coated by a high-voltage insulation layer to form the high-voltage winding. The rigid insulating lining cylinder is an inner support body wound by a lead and plays a role in supporting, but the rigid insulating lining cylinder is poor in heat conduction effect, the interface formed on the outer surface of the rigid insulating lining cylinder can weaken the insulation strength of a high-voltage insulating layer, surface discharge of the rigid insulating lining cylinder is easily caused under the action of lightning transient high voltage, the radial size of a product is increased due to the use of the rigid insulating lining cylinder, copper and iron materials are increased, and the cost is high.

Disclosure of Invention

Aiming at the defects of the prior art, the application aims to provide a preparation method of a high-voltage winding, the preparation method has simple steps, the required preparation tool has a simple structure and is easy to prepare, and the high-voltage winding prepared by the method omits the structure of a rigid insulating lining cylinder, so that the heat conduction effect of the high-voltage winding is better, and the interface between a high-voltage insulating layer and the rigid insulating lining cylinder does not exist, thereby avoiding the surface discharge of the rigid insulating lining cylinder, saving materials and reducing the cost.

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 a winding part, an auxiliary part, a high-voltage coil and a high-voltage insulating layer, wherein a lead is wound on the winding part to form the high-voltage coil, and the high-voltage insulating layer wraps the high-voltage coil, the winding part and the auxiliary part, and the preparation method comprises the following steps:

step a: sticking a high-temperature resistant film on the peripheral surface of the winding tool;

step b: fixing the winding part on the high-temperature-resistant film, and additionally installing an auxiliary piece to enable the auxiliary piece to stably clamp and fix the winding part;

step c: winding a lead on the winding part to form a high-voltage coil with a tap switch;

step d: putting the winding part wound with the high-voltage coil as a body to be injected into an injection machine together with a winding tool, and integrally injecting high-temperature vulcanized silicone rubber at the periphery of the body to be injected to form a high-voltage insulating layer to obtain a high-voltage winding;

step e: and demolding the high-voltage winding from the winding tool.

Preferably, the winding tool comprises a die and a connecting rod, the connecting rod penetrates through the die along the axial direction of the die, and in the step a, the high-temperature-resistant film is fixed on the outer peripheral surface of the die through a high-temperature-resistant adhesive tape.

Preferably, the auxiliary member includes a middle auxiliary member, and in step b, the middle auxiliary member is firstly sleeved on the high-temperature-resistant film, and then the winding portion is arranged along the circumferential direction of the winding tool, so that the inner wall of the middle auxiliary member is flush with the inner wall of the winding portion. When the winding tool cannot fix the winding part, the middle auxiliary part is additionally arranged, so that the stable arrangement of the winding part can be kept, and the moving dislocation of the winding part in the winding process of the lead and the injection process of the high-voltage insulating layer is avoided; the inner wall of middle part auxiliary member and the inner wall parallel and level of wire winding portion have avoided wire coiling in-process and high-pressure insulating layer injection in-process wire winding portion to use middle part auxiliary member to take place to buckle as the center.

Preferably, the inner wall of the winding portion is provided with a groove, and in the step b, the middle auxiliary member is clamped in the groove, so that the effective connection between the middle auxiliary member and the winding portion is ensured.

Preferably, the auxiliary member includes an end auxiliary member, and in step b, the winding portion is disposed along a circumferential direction of the winding tool, and then the end auxiliary member is fixed to an outer side of an end of the winding portion. The end auxiliary part is arranged outside the end part of the winding part, so that the stable arrangement of the winding part can be kept, and the winding of the wire cannot be influenced.

Preferably, a clamping groove is formed at the outer side of the end of the winding part, and in the step b, the end auxiliary member is inserted into the clamping groove, so that the effective connection between the end auxiliary member and the winding part is ensured.

Preferably, the winding part includes a plurality of comb-shaped winding plates, and in the step b, the plurality of winding plates are arranged at intervals and circumferentially and uniformly distributed on the outer circumferential surface of the winding tool. The comb-shaped winding plate is convenient for orderly winding of the lead to form the high-voltage coil.

Preferably, the conducting wires comprise a first conducting wire and a second conducting wire, and in the step c, the first conducting wire is wound to the middle of the winding part from the first end of the winding part along the axial direction of the high-voltage winding and is led out of the first tapping switch; and the second lead is wound to the second end of the winding part from the middle part of the winding part along the axial direction of the high-voltage winding and led out of the second tapping switch.

Preferably, step e is followed by step f: trimming burrs of the high-temperature resistant film remained on the inner surface of the high-voltage winding to prevent the burrs from generating partial discharge.

Preferably, in the step b, the winding part is bonded to the high temperature resistant film, and the connection strength of the winding part is reinforced.

The beneficial effect of this application is: the preparation method of the high-voltage winding is simple in steps, the required preparation tool is simple in structure and easy to manufacture, and the high-voltage winding prepared by the method omits a rigid insulating lining cylinder, so that the heat conduction effect of the high-voltage winding is better, an interface between a high-voltage insulating layer and the rigid insulating lining cylinder does not exist, the surface discharge condition of the rigid insulating lining cylinder does not exist, the material is saved, and the cost is reduced.

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 front view of a core clamp 140 according to an embodiment of the present application;

fig. 6 is a side view of a core clamp 140 according to an embodiment of the present application;

FIG. 7 is a schematic perspective view of a high voltage winding 130 according to an embodiment of the present application;

fig. 8 is a perspective view illustrating a state where the wire winding plate 1311 is fixed to the auxiliary member 1340 according to an embodiment of the present application;

fig. 9 is an enlarged view illustrating a fixing portion of the wire winding plate 1311 and the end auxiliary 1341 in fig. 8;

fig. 10 is an enlarged view illustrating a fixing portion of the wire bobbin 1311 and the middle auxiliary member 1342 of fig. 8;

fig. 11 is a perspective view illustrating a high voltage coil 1320 of an embodiment of the present application wound on a bobbin 1311;

FIG. 12 is a schematic circuit diagram of a high voltage coil 1320 according to an embodiment of the subject application;

fig. 13 is a schematic perspective view of a winding tool 20 according to an embodiment of the present application;

fig. 14 is a perspective view illustrating the auxiliary member 1340 and the winding plate 1311 assembled on the winding tool 20 according to an embodiment of the present disclosure;

fig. 15 is a perspective view illustrating a high voltage coil 1320 according to an embodiment of the present application wound around a winding tool 20;

FIG. 16 is a schematic injection diagram of an 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 iron core 110.

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. 1-2 and 5-6, a core clip 140 is disposed on an outer side of the core 110, and the core clip 140 is used for clamping the core 110. The core clip 140 is formed by connecting three clip members, each of which is a plate member, the clip member located at the middle position is defined as a first clip member 142, the other two clip members are defined as second clip members 143, and the two second clip members 143 extend in the same direction at two sides where the first clip member 142 and the two second clip members 143 are connected, so that the core clip 140 is in a structure similar to a channel steel, that is, a structure shaped like an "Contraband" can be formed. Preferably, the second clip member 143 is disposed perpendicular to the first clip member 142. The first clamping member 142 is used to be closely attached to the core 110, and the second clamping member 143 faces away from the core 110. After the core clamp 140 is mounted, the plate surface of the first clamp 142 is disposed along the axial direction of the core 110, and the plate surface of the second clamp 143 is disposed along the radial direction of the core 110. Specifically, in an application scenario, the axial direction of the core 110 is along the vertical direction, and the radial direction of the core 110 is along the horizontal direction. 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 both adopt a plurality of screws and bolts which are used in cooperation with each other to clamp two ends of the iron core 110 through the two iron core clamping pieces 140 respectively. First through holes 141 are opened at both ends of the core clip 140, and specifically, two first through holes 141 are opened at both ends of the first clip 142. The two core clamps 140 are correspondingly placed at two sides of the upper end of the core 110, and screws (not shown) are simultaneously inserted into the two first through holes 141 at the same end of the two core clamps 140, and then the two core clamps 140 are fastened and fixed by bolts, so that the two core clamps 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 second clip member 143 is further provided with 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, specifically, may be formed by compression molding of glass fiber-impregnated epoxy resin, or by compression molding of aramid fiber-impregnated epoxy resin, or may be made of other composite materials, and the first clip 142 and the second clip 143 are integrally formed, 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, for example, the first clip and the second clip may be different sidewalls of an integrally formed channel, or may be connected and fixed by welding after being separately formed. 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. The copper foil 121 is wound by the whole piece of copper foil paper, and the low-voltage insulating layer 122 and the copper foil 121 are overlapped and then wound together, so that the copper foil 121 and the low-voltage insulating layer 122 are alternately arranged. 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, which is prepared by impregnating a polyimide film and polysulfone fiber non-woven fabric soft composite material with diphenyl ether resin and then baking, and may be made of DMD insulated paper or silicone rubber film, or other insulated 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.

The inner ring layer of the low-voltage winding 120 is further provided with an inner lead copper bar, the outer ring layer of the low-voltage winding 120 is further provided with an outer lead copper bar, the free ends of the inner lead copper bar and the outer lead copper bar are provided with connecting holes, and the connecting holes are correspondingly matched with the second through holes in the iron core clamping pieces 140 and then are fastened and connected.

As shown in fig. 7-12, the high voltage winding 130 includes a winding portion 1310, a high voltage coil 1320, a high voltage insulation layer 1330, and an auxiliary piece 1340; the winding portion 1310 is circumferentially arranged on the inner side of the high-voltage winding 130, a wire is wound on the winding portion 1310 to form a high-voltage coil 1320, and the high-voltage coil 1320 comprises a plurality of sections of coils which are arranged at intervals along the axial direction of the high-voltage winding 130; the auxiliary member 1340 is annular, coaxial with the high voltage winding 130, and is fixed on the winding portion 1310; the high voltage insulating layer 1330 wraps the high voltage coil 1320, the auxiliary piece 1340, and the winding portion 1310. The high-voltage winding 130 omits a rigid insulation lining barrel structure, so that the heat conduction effect of the high-voltage winding 130 is better, an interface between the high-voltage insulation layer 1330 and the rigid insulation lining barrel does not exist, the surface discharge condition of the rigid insulation lining barrel does not exist, the material is saved, and the cost is reduced.

In the present embodiment, the winding portion 1310 includes a plurality of comb-shaped winding plates 1311, the plurality of winding plates 1311 are disposed at intervals and are circumferentially distributed on the inner side of the high voltage winding 130, and each winding plate 1311 is disposed along the axial direction of the high voltage winding 130. The high voltage coil 1320 includes a plurality of segments of coils, and at least one segment of coil is disposed between two adjacent comb teeth on the winding plate 1311. The number of the winding boards 1311 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 1311 of the 10kV/1000kVA dry type transformer is twelve.

The winding board 1311 is a rectangular board, the longer side of the winding board 1311 is disposed along the axial direction of the high voltage winding 130, a plurality of winding slots 1312 are further disposed on the winding board 1311, and the plurality of winding slots 1312 are disposed along the radial direction of the high voltage winding 130 and are distributed at intervals along the axial direction of the high voltage winding 130, so that the winding board 1311 is in a comb shape, that is, a plurality of comb teeth are formed on the winding board 1311. The height of the comb teeth on the winding board 1311 along the axial direction of the high-voltage winding 130 is defined as the tooth height, the tooth heights at the two ends of the winding board 1311 and the tooth height in the middle of the winding board 1311 are both greater than those of 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 1311 are set to be larger than those of the other parts, so that an electric field can be uniform, a joint of a branch wire needs to be led out from the middle of the winding board 1311, the tooth height in the middle of the winding board 1311 is set to be larger than that of the two corresponding adjacent winding grooves 1312, and a placement space can be reserved for the joint led out from the middle of the winding board 1311. At least one section of coil is arranged between two adjacent comb teeth on the winding board 1311, so that a conducting wire is wound in each winding groove 1312, high-voltage coils 1320 are reasonably distributed and arranged, and the coils of the sections are arranged at intervals. 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 1311 sequentially forms a first high comb tooth region, a first low comb tooth region, a second high comb tooth region, a second low comb tooth region, and a third high comb tooth region from one end toward the other end in the axial direction of the high-voltage winding 130. 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.

When the plurality of winding plates 1311 are uniformly distributed in the circumferential direction, two ends of all the winding plates 1311 are flush with each other, the winding grooves 1312 in all the winding plates 1311 are matched in a one-to-one correspondence manner in the circumferential direction of the high-voltage winding 130, each section of coil is wound in a circle of corresponding winding groove 1312 in all the winding plates 1311 in the circumferential direction through a conducting wire, stress is balanced, and mechanical strength is good.

In other embodiments, in order to set the positions of the taps away, the plurality of winding boards may also be fixed in a non-uniform 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 larger, and the setting position of each tap can also be reserved.

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

In this embodiment, the winding board 1311 is made of glass fiber impregnated epoxy resin, multiple layers of glass fiber cloth impregnated with epoxy resin are stacked to a certain thickness, and are molded and cured to form a rectangular glass fiber reinforced plastic plate, and a winding groove 1312 is formed in the glass fiber reinforced plastic plate, specifically, the winding groove 1312 may be formed by turning, thereby forming the winding board 1311. When a lead is wound, the winding board 1311 is fixedly connected to the outer peripheral surface of the winding tool through an adhesive, materials are saved most, 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 winding tool with the winding board 1311, and is high temperature resistant so as to adapt to the high temperature injection high pressure insulation layer 1330 outside the winding portion 1310.

It should be noted that, in this embodiment, the winding board 1311 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 will not be described again.

The winding portion 1310 is made of the fiber reinforced composite material, has the characteristics of light weight and high strength, enables the winding portion 1310 to have good 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 portion 1310; and the fiber reinforced composite material has good heat resistance, so that the deformation of the winding portion 1310 caused by the excessive heat generated by the high-voltage coil 1320 during the operation of the dry-type transformer 10 is avoided.

As shown in fig. 8, the auxiliary member 1340 is ring-shaped and coaxial with the high voltage winding 130, and is fixed on the plurality of winding boards 1311. The additional auxiliary member 1340 can maintain the stable arrangement of the winding board 1311, thereby preventing the movement and dislocation of the winding board 1311 during the winding process of the conductive wires and the injection process of the high voltage insulation 1330.

In one embodiment, the auxiliary member 1340 includes at least one end auxiliary member 1341, the end auxiliary member 1341 is disposed outside an end of the winding board 1311, and the end auxiliary member 1341 is disposed outside the end of the winding board 1311, so that the end auxiliary member 1341 can maintain a stable configuration of the winding board 1311 and does not affect the winding of the wires. At this time, referring to fig. 9, a card slot 1313 is provided at an end of the winding board 1311, and an end auxiliary 1341 is inserted into the card slot 1313, ensuring effective connection of the end auxiliary 1341 with the winding board 1311. The slot 1313 is located on the comb side of the winding board 1311, i.e., the winding board 1311 is away from the axis of the high voltage winding 130, so that the end auxiliary member 1341 can fix the winding board 1311 better, and the movement and dislocation of the winding board 1311 during the wire winding process and the injection process of the high voltage insulating layer 1330 are avoided. The groove depth of the clamping groove 1313 is greater than or equal to the thickness of the end part auxiliary piece 1341, so that glue liquid can coat the end part of the winding board 1311 and the end part auxiliary piece 1341 when glue is injected, and the connection failure of the winding board 1311 and the end part auxiliary piece 1341 caused by the influence of external force is not easy to occur. The end auxiliary member 1341 is fixedly connected to the slot 1313 by an adhesive, which is a two-component high-temperature-resistant epoxy adhesive, but may be other adhesives, but it needs to be ensured that the adhesive can firmly bond the end auxiliary member 1341 to the winding board 1311, and is high-temperature-resistant, so as to adapt to the high-pressure insulating layer 1330 coated on the peripheries of the winding board 1311 and the end auxiliary member 1341 by high-temperature injection.

Alternatively, in another embodiment, the auxiliary member 1340 includes a middle auxiliary member 1342, and the middle auxiliary member 1342 is disposed on the inner wall of the winding board 1311, so as not to affect the winding of the comb-side wires of the winding board 1311. Referring to fig. 10, the inner wall of the wire spool 1311 is provided with a groove 1314, and the middle auxiliary member 1342 is snapped into the groove 1314, ensuring an effective connection of the middle auxiliary member 1342 with the wire spool 1311. The groove depth of the groove 1314 is matched with the ring width of the middle auxiliary piece 1342, so that after the middle auxiliary piece 1342 and the winding board 1311 are assembled, the inner wall of the middle auxiliary piece 1342 is flush with the inner wall of the winding board 1311, and the situation that the winding board 1311 bends around the middle auxiliary piece 1342 in the wire winding process and the high-voltage insulating layer 1330 injection process when the groove depth of the groove 1314 is smaller than the ring width of the middle auxiliary piece 1342 or the middle auxiliary piece 1342 cannot play a role in fastening when the groove depth of the groove 1314 is greater than the ring width of the middle auxiliary piece 1342 is avoided.

In this embodiment, the auxiliary member 1340 includes two end auxiliary members 1341 and a middle auxiliary member 1342, so that the winding board 1311 can maintain the stability of the position during the wire winding process and the injection process of the high voltage insulating layer 1330, and no movement or dislocation occurs, thereby preventing the two coils from being too close to each other and generating discharge due to insufficient insulating distance.

The auxiliary member 1340 is also made of glass fiber impregnated epoxy resin, and is laminated to a certain thickness by multiple layers of glass fiber cloth impregnated epoxy resin, and is molded and cured to form an annular glass fiber reinforced plastic plate member. The auxiliary member 1340 is shaped and sized to match the high voltage winding 130, and may be circular, elliptical, or other ring shape. The thickness of the end auxiliary member 1341 should be smaller than the tooth height of the comb teeth at the two ends of the wire winding plate 1311, and when the thickness of the middle auxiliary member 1342 is not required, the loop width thereof should be smaller than the width of the non-comb teeth portion of the wire winding plate 1311, that is, the width of the wire winding groove 1312 subtracted from the entire width of the wire winding plate 1311, or when the loop width of the middle auxiliary member 1342 is not required, the thickness thereof should be smaller than the tooth height of the comb teeth at the middle of the wire winding plate 1311. This arrangement prevents the auxiliary member 1340 from occupying the winding slot 1312 and affecting the winding of the wire on the winding plate 1311.

In this embodiment, the auxiliary piece 1340 is molded and cured, and in other embodiments, the auxiliary piece may be directly molded by integral injection and curing, so as to simplify the process, and the material of the auxiliary piece is the same as that described above, and is not described again.

In an application scenario, the auxiliary member 1340 is formed separately from the winding board 1311 and then bonded and fixed thereto. In another application scenario, the auxiliary piece 1340 is integrally formed with the wire board 1311. Specifically, a hollow tube with a large thickness is formed by pultrusion or winding glass fiber or aramid fiber impregnated epoxy resin, and then the hollow tube is turned, so that the auxiliary piece 1340 and the winding board 1311 are formed, which is wasteful of materials, but can ensure the strength between the auxiliary piece 1340 and the winding board 1311, and prevent the connection between the auxiliary piece 1340 and the winding board 1311 from being damaged due to the insecure adhesion or in the subsequent process of injecting an insulating medium.

Referring to fig. 7 and 11, taking the phase a transformer 100 as an example, a wire is wound around the outer circumferential surface of the winding portion 1310 in the circumferential direction to form a high voltage coil 1320. Specifically, the wire is wound in the winding slot 1312 of the winding board 1311, so that the high-voltage coil 1320 is spaced apart in the axial direction of the high-voltage winding 130, and the wire forms two external connections, i.e., a first external connection D and a second external connection X, at the end and the end after winding, where the first external connection D is used for connecting a cable, and the second external connection X is used for connecting other external connections, e.g., in a three-phase transformer, for connecting with each other between the phase-change transformers. And, the conductive wire is led out at the middle of the high voltage winding 130 along 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. 7, 11, and 12, the wires include a first wire and a second wire, both the first wire and the second wire are continuous wires, and both the outside of the first wire and the outside of 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 used by combining multiple insulating materials, which is not limited herein. Referring to fig. 11, for convenience of description, the upper end of the winding portion 1310 is defined as a first end, the lower end of the winding portion 1310 is defined as a second end, and a first wire is wound from the first end of the winding portion 1310 to the middle of the winding portion 1310 in the axial direction of the high voltage winding 130, and three taps are led out. The first wire is wound from the first end of the winding portion 1310 to the second end of the winding portion 1310, the first wire is wound in a first winding slot 1312 of a corresponding turn on all the winding plates 1311 to form a first coil segment 1321, the first coil segment 1321 is pie-wound, only one pie coil is arranged in each winding slot 1312, and at this time, only one pie coil is arranged in each coil segment. The inner turn lead end of the first lead at the first end of the winding portion 1310 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 the second winding groove 1312 on all the winding plates 1311 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 portion 1310, and three taps, that is, a tap 6, a tap 4 and a tap 2 shown in fig. 7, are led out from the outer turn lead ends of three coils respectively, so that the first lead is wound.

A second wire is wound from the middle of the winding portion 1310 to the second end of the winding portion 1310 in the axial direction of the high voltage winding 130, and three other taps are led out. Specifically, the second wire is wound in the winding groove 1312 of the next winding adjacent to the tap 2 to form a third-stage coil 1323, the second wire is wound to the second end of the winding portion 1310 in the same winding manner as the first wire, and three other taps, i.e., tap 3, tap 5 and tap 7, are respectively led out from the three-stage coil in which the third-stage coil 1323 is started until the second wire is wound to the last winding groove 1312 of the corresponding winding plate 1311 at the second end of the winding portion 1310 to form a terminal-stage coil 1324. The outer turn end of the second wire at the second end of the winding portion 1310 forms a second external connection X exposed outside the high voltage insulation layer 1330, that is, the second external 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 wire is wound, the wire is wound in the corresponding winding groove 1312 of one circle on all the winding plates 1311, so that each section of coil formed by winding the wire is perpendicular to the axial direction of the high-voltage winding 130, the winding is convenient, the wire is orderly arranged, the stress of the winding plates 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 high voltage winding 130, as shown in fig. 7 and 11, the tap 6, the tap 4, and the tap 2 are sequentially distributed to form a first tap switch, the tap 3, the tap 5, and the tap 7 are sequentially distributed to form a second tap switch, the first tap switch and the second tap switch are arranged in parallel, and the six taps form tapping devices of the high voltage coil 1320 for adjusting the voltage of the dry type transformer 10 according to different operating conditions.

The high voltage coil 1320 is formed by winding a wire around the winding portion 1310, so that the high voltage coil 1320 is annular, the annular width of the high voltage coil 1320 is defined as the width of the high voltage coil 1320, and the widths of the high voltage coil 1320 in all radial cross sections are uniform, that is, the outer side surface of the high voltage coil 1320 is equidistant from the outer peripheral surface of the high voltage winding 130, so that the high voltage coil 1320 is balanced in stress. 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 1312 of the next winding turn adjacent to the tap 2 to the winding groove 1312 of the last winding turn at the second end of the winding portion 1310, and in other embodiments, the second conductive wire may be wound from the winding groove 1312 of the last winding turn at the second end of the winding portion up to the winding groove 1312 of the next winding 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 formed in this order. 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.

Referring to fig. 7 and 8, the high voltage insulation layer 1330 wraps the high voltage coil 1320, the winding 1310 and the auxiliary member 1340 to form the high voltage winding 130. The high voltage insulating layer 1330 is a high temperature vulcanized silicone rubber. Compared with the existing room temperature vulcanization process, the high-temperature vulcanized silicone rubber can ensure that the high-voltage insulating layer 1330 is more stable and has higher mechanical property, and the high-voltage insulating layer 1330 has better adhesive property with the high-voltage coil 1320, the auxiliary piece 1340 and the winding part 1310, and can effectively prolong the service life of the high-voltage insulating layer 1330. In addition, compared with liquid silicone rubber, the silicone rubber filler is uniformly dispersed, partial discharge caused by filler agglomeration is avoided, and the product performance is better. Specifically, a high-voltage coil 1320 is formed after a conducting wire is wound on the winding portion 1310, the auxiliary piece 1340 and the high-voltage coil 1320 are used as a body to be injected, the body to be injected is placed in a mold of an injection machine, high-temperature vulcanized silicone rubber is injected integrally on the periphery of the body to be injected by adding silicone rubber raw materials, the high-voltage winding 130 is obtained, and the high-voltage insulating layer 1330 is made of the high-temperature vulcanized silicone rubber, so that the insulating performance and the mechanical performance of the high-voltage winding 130 are integrally improved.

After the high-voltage coil 1320, the auxiliary element 1340 and the winding portion 1310 are coated by the integral vacuum injection of the high-temperature vulcanized silicone rubber, the high-temperature vulcanized silicone rubber fills gaps among the high-voltage coil 1320, the auxiliary element 1340 and the winding portion 1310 and coats the high-voltage coil 1320, the winding portion 1310 and the auxiliary element 1340, so that the high-voltage winding 130 is integrally in a hollow cylindrical shape, which can be a hollow cylinder, a hollow elliptic cylinder or other hollow cylindrical bodies.

Different from the situation in the prior art, the high-voltage winding 130 does not include a rigid insulating lining cylinder, so that the heat conduction effect of the high-voltage winding 130 is better, an interface between the high-voltage insulating layer 1330 and the rigid insulating lining cylinder does not exist, the surface discharge condition of the rigid insulating lining cylinder does not exist, the material is saved, and the cost is reduced. The dry-type transformer 10 of the present application is low in manufacturing cost and excellent in performance.

An embodiment of the present invention provides a method for preparing a high voltage winding 130, comprising the steps of:

step a: a high temperature resistant film (not shown) is attached to the outer peripheral surface of the winding tool 20.

As shown in fig. 13, the winding tool 20 includes a die 21 and a connecting rod 22, the connecting rod 22 penetrates through the die 21 along an axial direction of the die 21, and the connecting rod 22 is used for connecting the winding tool 20 with a winding machine to wind a wire. The mold 21 is a hollow shell, and may be a hollow cylinder, a hollow elliptic cylinder, or another hollow cylindrical body, and the outer circumferential surface of the mold 21 is matched with the inner circumferential surface of the high-voltage winding 130. The hollow die 21 is light in weight, and can ensure that the winding tool 20 is within the bearing range of the winding machine. In addition, in order to ensure that the winding tool 20 can bear the injection pressure during injection, the mold 21 may be made of a hard metal material such as iron, or a reinforcing rib may be welded inside the mold 21 to improve the mechanical strength of the mold 21.

The high temperature resistant film is fixed on the outer circumferential surface of the mold 21 by using a high temperature resistant polyimide tape or other high temperature resistant tapes, so that the high-voltage winding 130 injected with the high temperature vulcanized silicone rubber is easy to demould. In order to better bond the wire and the high-temperature vulcanized silicone rubber, a coupling agent is coated on the wire, in the prior art, in order to facilitate demolding after injection, a demolding agent is generally coated outside a mold, the coupling agent and the demolding agent can generate chemical reaction at high temperature to influence the performance of the high-voltage winding 130, and in order to avoid the situation and facilitate demolding, the demolding agent is replaced by a high-temperature-resistant film.

The high temperature resistant film is a film capable of resisting 175 ℃, and the highest temperature is 175 ℃ when the injection machine injects, and the high temperature resistant film only needs to be ensured not to be damaged at the highest injection temperature. For example, the FEP film can be an FEP film, is a high-temperature resistant isolating film, has high and low temperature resistance of-200 ℃, low friction, non-adhesiveness, lubricity, chemical corrosion resistance, thermal stability and electrical insulation, and cannot be damaged at the maximum injection temperature of 175 ℃. In addition, a high temperature resistant film such as a polyimide film may be used as long as it is not broken at the maximum injection temperature of 175 ℃. It will be apparent that films resistant to higher temperatures may also be suitable.

Since the high-voltage winding 130 does not include a rigid insulating inner bushing, the shape of the inner peripheral surface thereof matches the shape of the outer peripheral surface of the die 21, and the high-voltage winding 130 having different inner diameters and inner peripheral surface shapes can be produced by changing the size and shape of the die 21 of the winding tool 20.

Step b: the winding portion 1310 is fixed on the high temperature resistant film, and the auxiliary piece 1340 is additionally installed to stably fix the winding portion 1310 by the auxiliary piece 1340.

In one embodiment, the auxiliary member 1340 includes a middle auxiliary member 1342, and the middle auxiliary member 1342 is first sleeved outside the high temperature resistant film on the winding tool 20. Referring to fig. 14, the middle auxiliary member 1342 is sleeved on the outer circumferential surface of the mold 21, specifically, the middle auxiliary member 1342 is firstly sleeved on the middle portion of the mold 21, and then the middle auxiliary member 1342 is engaged in the groove 1314 by adjusting the position of the groove 1314 on the winding board 1311.

Then, the winding portion 1310 is disposed along the circumferential direction of the winding tool 20 such that the inner wall of the middle auxiliary member 1342 is flush with the inner wall of the winding portion 1310. The winding portion 1310 is bonded to the high-temperature-resistant film along the circumferential direction of the winding tool 20 by an adhesive, and a plurality of winding grooves 1312 are formed in the winding portion 1310 for subsequently winding a wire.

Referring to fig. 10 and 14, when the winding portion 1310 is a plurality of comb-shaped winding plates 1311, the plurality of winding plates 1311 are disposed at intervals and circumferentially and uniformly distributed on the winding tool 20, and each winding plate 1311 is disposed along an axial direction of the winding tool 20. The winding board 1311 is provided with a plurality of winding grooves 1312, so that the winding board 1311 is comb-shaped, the winding grooves 1312 are used for subsequently winding wires, the inner wall of the winding board 1311 is bonded to a high-temperature-resistant film through an adhesive, the inner wall of the winding board 1311 is provided with a groove 1314, the middle auxiliary piece 1342 is clamped in the groove 1314, the groove depth of the groove 1314 is matched with the ring width of the middle auxiliary piece 1342, after the middle auxiliary piece 1342 and the winding board 1311 are assembled, the inner wall of the middle auxiliary piece 1342 is flush with the inner wall of the winding board 1311, and when the groove depth of the groove 1314 is smaller than the ring width of the middle auxiliary piece 1342, the winding board 1311 is bent by taking the middle auxiliary piece 1342 as the center in the wire winding process and the high-voltage insulating layer 1330 injection process, or when the groove depth of the groove 1314 is larger than the ring width of the middle auxiliary piece 1342, the middle auxiliary piece 1342 cannot play a fastening role. The wire winding board 1311 is engaged with the middle auxiliary member 1342 through the groove 1314, and the middle auxiliary member 1342 and the wire winding board 1311 are also adhered by an adhesive.

In another embodiment, the auxiliary piece 1340 includes an end auxiliary piece 1341, the winding portion 1310 is disposed along a circumferential direction of the winding tool 20, and the end auxiliary piece 1341 is fixed outside an end of the winding portion 1310, and the end auxiliary piece 1341 is coaxial with the winding tool 20.

Referring to fig. 9 and 14, the end auxiliary member 1341 is adhesively fixed to the outer side of the end of the winding portion 1310 by an adhesive, so that the winding portion 1310 can be stably fixed without affecting the winding of the wire. Specifically, a clamping groove 1313 is arranged at one end of the winding portion 1310 where the end auxiliary piece 1341 needs to be installed, the end auxiliary piece 1341 is embedded into the clamping groove 1313, the groove depth of the clamping groove 1313 is greater than or equal to the thickness of the end auxiliary piece 1341, glue is convenient to coat the end of the winding portion 1310 and the end auxiliary piece 1341 during glue injection, and connection failure of the winding portion 1310 and the end auxiliary piece 1341 is not easily caused by external force. The end auxiliary member 1341 is fixedly attached to the notch 1313 by an adhesive. When the winding portion 1310 is a plurality of comb-shaped winding plates 1311, slots 1313 are provided on the comb teeth at the end, and the end auxiliary member 1341 is inserted into the slots 1313 by an adhesive.

The adhesives are two-component high-temperature-resistant epoxy adhesives, and may be other adhesives, but it is necessary to ensure that the adhesives can firmly bond the middle auxiliary piece 1342, the end auxiliary piece 1341 and the winding portion 1310, and are high-temperature-resistant, so as to adapt to the high-pressure insulating layer 1330 covering the peripheries of the winding portion 1310 and the auxiliary piece 1340 in a high-temperature injection manner.

Further, the accessory 1340 includes two end accessories 1341. Two end auxiliary pieces 1341 are respectively bonded to the outer sides of the two ends of the winding portion 1310, and the end auxiliary pieces 1341 are coaxial with the winding tool 20.

In another embodiment, the auxiliary member 1340 includes a middle auxiliary member 1342 and two end auxiliary members 1341, the middle auxiliary member 1342 is firstly sleeved on the outer circumferential surface of the mold 21, then the plurality of winding boards 1311 are fixed on the outer surface of the winding tool 20, the middle auxiliary member 1342 is engaged with the groove 1314, and then the two end auxiliary members 1341 are respectively adhered to the outer sides of the two ends of the winding portion 1310, so that the end auxiliary members 1341 are inserted into the slots 1313. In another embodiment, the middle auxiliary member and the end auxiliary member may be fixed to the winding portion by bonding and then fixed to the winding tool.

Step c: a wire is wound on the winding portion 1310 to form a high voltage coil 1320 with a tap changer.

In conjunction with fig. 7, 11, 12 and 15, a first conductive line and a second conductive line are provided. A first conductive wire is wound from the first end of the winding portion 1310 to the middle of the winding portion 1310 in the axial direction of the high voltage winding 130, and three taps are led out to form a first tap switch. Specifically, the first wire is wound from the first end of the winding portion 1310 to the second end of the winding portion 1310, the first wire is wound in the first winding slot 1312 of a corresponding turn on all the winding plates 1311 to form a first coil segment 1321, the first coil segment 1321 is formed by pie winding, only one pie coil is disposed in each winding slot 1312, 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 1310 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 the second winding groove 1312 on all the winding plates 1311 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 portion 1310, and three taps, that is, a tap 6, a tap 4 and a tap 2 shown in fig. 7, 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 1310 to the second end of the winding portion 1310 along the axial direction of the high voltage winding 130, and three other taps are led out to form a second tap switch. Specifically, the second wire is wound in the winding slot 1312 of the next turn adjacent to the tap 2 to form a third-stage coil 1323, the second wire is wound to the second end of the winding portion 1310 in the same winding manner as the first wire, and three other taps, i.e., tap 3, tap 5 and tap 7, are respectively led out from the three-stage coil in which the third-stage coil 1323 is started until the second wire is wound to the last winding slot 1312 of the corresponding turn on each winding plate 1311 at the second end of the winding portion 1310 to form a terminal-stage coil 1324. The outer turn end of the second wire at the second end of the winding portion 1310 forms a second external connection X exposed outside the high voltage insulation layer 1330, that is, the second external 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 high voltage coil 1320 is formed after the second wire is wound.

Step d: referring to fig. 16, a winding portion 1310 wound with a high voltage coil 1320 is placed into an injection machine as a body to be injected together with a winding tool 20, and a high voltage insulation layer 1330 is formed by injecting high temperature vulcanized silicone rubber integrally around the periphery of the body to be injected, so as to obtain a high voltage winding 130.

Step e: and demolding the high-voltage winding 130 from the winding tool 20.

The winding tool 20 and the high-voltage winding 130 are separated, and then the die can be removed, wherein the die removing mode is a mode commonly used in the industry, and is not described herein again.

In one embodiment, step e is followed by step f: trimming burrs of the high-temperature resistant film remained on the inner surface of the high-voltage winding 130 to prevent the burrs from generating partial discharge.

In another embodiment, if no burrs of the high-voltage winding inner surface remain, step f need not be performed. Or in step f, the residual high-temperature resistant film can be torn off, so that the inner wall of the high-voltage winding is kept clean and smooth.

The preparation method of the high-voltage winding 130 is simple in steps, the required winding tool 20 is simple in structure and easy to manufacture, and the high-voltage winding 130 prepared by the method omits a rigid insulating lining cylinder, so that the heat conduction effect of the high-voltage winding 130 is better, an interface between the high-voltage insulating layer 1330 and the rigid insulating lining cylinder does not exist, the surface discharge condition of the rigid insulating lining cylinder does not exist, materials are saved, and the cost is reduced.

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 is characterized in that the high-voltage winding comprises a winding portion, an auxiliary part, a high-voltage coil and a high-voltage insulating layer, a conducting wire is wound on the winding portion to form the high-voltage coil, and the high-voltage insulating layer wraps the high-voltage coil, the winding portion and the auxiliary part, and the preparation method comprises the following steps:

step b: fixing the winding part on the high-temperature-resistant film, and additionally installing the auxiliary piece to enable the auxiliary piece to stably clamp and fix the winding part;

step c: winding the wire on the winding part to form the high-voltage coil with a tap switch;

step d: putting the winding part wound with the high-voltage coil as a body to be injected into an injection machine together with the winding tool, and integrally injecting high-temperature vulcanized silicone rubber at the periphery of the body to be injected to form the high-voltage insulating layer to obtain the high-voltage winding;

step e: and demolding the high-voltage winding from the winding tool.

2. The method according to claim 1, wherein the winding tool comprises a die and a connecting rod, the connecting rod penetrates through the die along an axial direction of the die, and in the step a, the high-temperature-resistant film is fixed on an outer circumferential surface of the die by a high-temperature-resistant adhesive tape.

3. The method for manufacturing a high-voltage winding according to claim 1, wherein the auxiliary member comprises a middle auxiliary member, and in the step b, the middle auxiliary member is firstly sleeved on the high-temperature resistant film, and then the winding portion is arranged along the circumferential direction of the winding tool, so that the inner wall of the middle auxiliary member is flush with the inner wall of the winding portion.

4. A method of manufacturing a high voltage winding according to claim 3, wherein the inner wall of the winding portion is provided with a groove, and in step b, the middle auxiliary member is engaged in the groove.

5. The method for manufacturing a high-voltage winding according to claim 1, wherein the auxiliary member includes an end auxiliary member, and in the step b, the winding portion is disposed along a circumferential direction of the winding tool, and then the end auxiliary member is fixed to an outer side of an end portion of the winding portion.

6. The method of manufacturing a high voltage winding according to claim 5, wherein a catching groove is provided on an outer side of an end of the winding portion, and the end auxiliary member is inserted into the catching groove in the step b.

7. The method according to claim 1, wherein the winding portion includes a plurality of comb-shaped winding plates, and in the step b, the plurality of winding plates are arranged at intervals and circumferentially and uniformly distributed on the outer circumferential surface of the winding tool.

8. The method for preparing a high-voltage winding according to claim 1, wherein the conducting wire comprises a first conducting wire and a second conducting wire, and in the step c, the first conducting wire is wound from the first end of the winding part to the middle of the winding part along the axial direction of the high-voltage winding and leads out of the first tapping switch; and the second lead is wound to the second end of the winding part from the middle part of the winding part along the axial direction of the high-voltage winding and led out of the second tapping switch.

9. The method of making a high voltage winding according to claim 1, further comprising, after step e, step f: trimming burrs of the high-temperature resistant film remained on the inner surface of the high-voltage winding.

10. The method of claim 1, wherein in step b, the winding portion is bonded to the refractory film.