CN114300239A

CN114300239A - Dry-type transformer

Info

Publication number: CN114300239A
Application number: CN202111647922.8A
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: AR128125A1; CN114300239B

Abstract

The application discloses a dry-type transformer, which comprises an iron core, a low-voltage winding and a high-voltage winding, wherein the low-voltage winding is sleeved outside the iron core, and the high-voltage winding is sleeved outside the low-voltage winding; the high-voltage winding comprises a winding body, a high-voltage coil and a high-voltage insulating layer, wherein a wire is wound on the winding body to form the high-voltage coil, the high-voltage insulating layer is filled in a gap between the high-voltage coil and the winding body and two ends of the winding body, and the high-voltage insulating layer is made of high-temperature vulcanized silicone rubber. The dry-type transformer has good fireproof performance, ageing resistance and short-circuit resistance test capability; the coil can be recycled, the energy consumption is low, and the energy is saved and the environment is protected; the insulating layer is firm, and mechanical properties is good, long service life.

Description

Dry-type transformer

Technical Field

The application relates to the technical field of power transformers, in particular to a dry-type transformer.

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, the dry-type transformer has better fireproof performance, aging resistance and short-circuit resistance test capability; the coil can be recycled, the energy consumption is low, and the energy is saved and the environment is protected; the insulating layer is firm, and mechanical properties is good, long service life.

In order to achieve the purpose, the technical scheme adopted by the application is as follows: a dry-type transformer comprises an iron core, a low-voltage winding and a high-voltage winding, wherein the low-voltage winding is sleeved outside the iron core, and the high-voltage winding is sleeved outside the low-voltage winding; the high-voltage winding comprises a winding body, a high-voltage coil and a high-voltage insulating layer, wherein a wire is wound on the winding body to form the high-voltage coil, the high-voltage insulating layer is filled in a gap between the high-voltage coil and the winding body and two ends of the winding body, and the high-voltage insulating layer is made of high-temperature vulcanized silicone rubber. The dry-type transformer adopts the fiber reinforced composite material as the winding body and adopts the high-temperature vulcanized silicone rubber to form the high-voltage winding by pouring, so that the dry-type transformer has better fireproof performance, aging resistance and short-circuit resistance test capability, and the dry-type transformer has good overall mechanical performance and long service life.

Preferably, the winding body includes a winding portion, the winding portion includes a plurality of winding boards that circumference set up, sets up a plurality of winding grooves on the winding board and makes the winding board form a plurality of broach. The winding of the wire on the winding plate is firmer due to the circumferentially and uniformly distributed arrangement of the winding plate, and the wire can be supported in a balanced manner.

Preferably, the height of the comb teeth along the axial direction of the high-voltage winding is defined as the tooth height, the tooth height of the comb teeth in the middle of the winding board and the tooth height of the comb teeth at the two ends of the winding board are both greater than the tooth height of the comb teeth at the other parts of the winding board, so that the winding board 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 to the other end in the axial direction along the high-voltage winding. The tap that divides the wiring need be drawn forth in the middle part of the winder plate, sets up the tooth height in middle part of the winder plate a bit bigger for the distance between two adjacent wire winding grooves that correspond is bigger, can reserve for the tap and place the space. And because the end part field intensity of the high-voltage coil is not uniform, the tooth heights of the two ends of the winding plate are set to be larger, so that the electric field can be uniform.

Preferably, the first high comb tooth area and the third high comb tooth area are symmetrically arranged with respect to the second high comb tooth area, and the first low comb tooth area and the second low comb tooth area are symmetrically arranged with respect to the second high comb tooth area. The high-voltage coils are symmetrically arranged in the axial direction of the high-voltage winding, and the center of gravity of the high-voltage winding is located at the center of the high-voltage winding, so that the high-voltage winding is convenient to hoist and transport.

Preferably, the winding body further comprises an auxiliary piece, the auxiliary piece is connected with the plurality of winding plates in a clamping mode, so that the structure of each winding plate is stable, and the supporting force for winding the wire can be borne.

Preferably, the winding body further comprises a supporting cylinder, the supporting cylinder is a hollow cylinder, the plurality of winding plates are circumferentially and uniformly distributed on the outer peripheral surface of the supporting cylinder, and the length direction of each winding plate is arranged along the axial direction of the supporting cylinder. The circumferential uniform arrangement of the winding plate ensures that the wires can be wound more firmly on the outer circumferential surface of the supporting cylinder, and the wires can be supported in a balanced manner.

Preferably, the auxiliary member includes middle part auxiliary member and tip auxiliary member, and the middle part auxiliary member sets up in the inner wall of winder, and the tip auxiliary member sets up in the tip outside of winder, can keep the firm setting of winder, can not exert an influence to the coiling of wire again.

Preferably, the high-voltage coil comprises a plurality of sections of coils, the conducting wire is wound in the winding groove, so that the plurality of sections of coils are arranged at intervals along the axial direction of the high-voltage coil, at least one section of coil is arranged between two adjacent comb teeth on the winding plate, and the coils are wound on the comb-tooth-shaped winding plate, so that the stability is improved, and the displacement of the coils is prevented.

Preferably, each section of coil is wound in a layer-type reciprocating manner along the axial direction of the high-voltage winding and is in a spiral shape closely arranged on the outer periphery of the winding body, so that a layer-type high-voltage coil is formed.

Preferably, the coil is provided with at least one interlayer insulating layer along the axial direction of the high-voltage winding, the interlayer insulating layer is an insulating strip with a wavy edge, the mechanical strength of the interlayer insulating layer is higher, and when the high-voltage insulating layer is high-temperature vulcanized silicone rubber, the interlayer insulating layer can resist the impact force of silicone rubber during high-temperature injection.

Preferably, four iron core clamping pieces are arranged on the outer side of the iron core, the iron core clamping pieces are made of fiber reinforced composite materials, and the iron core clamping pieces are used for clamping and fixing the upper end and the lower end of the iron core and are matched with the overall installation of the dry-type transformer.

Preferably, the iron core clamping piece is formed by compression molding or pultrusion of fiber material impregnated epoxy resin, and compared with a traditional channel steel structure, the iron core clamping piece has more excellent economic performance, an insulating pad fixed on the outer surface of the iron core can be omitted, the cost of the fiber reinforced composite material is lower, and the total cost can be reduced by about 60%.

Preferably, the low-voltage winding comprises a copper foil and low-voltage insulating layers, and the copper foil and the low-voltage insulating layers are alternately arranged, so that the insulating property of the low-voltage winding can be ensured.

Preferably, the low-voltage insulating layer is an SHS-P diphenyl ether prepreg or a silicon rubber film, so that the insulation of the low-voltage winding can be further ensured, and different temperature rise grade requirements of the dry-type transformer can be met.

Preferably, at least one heat dissipation air channel is arranged in the low-voltage winding and located between the copper foil and the low-voltage insulating layer, so that heat generated by the low-voltage winding can be released in the operation process of the dry-type transformer, and overheating failure of the dry-type transformer is avoided.

Preferably, the conducting wire comprises a first conducting wire and a second conducting wire, the first conducting wire is wound to the middle of the winding portion from the first end of the winding portion along the axial direction of the high-voltage winding, the second conducting wire is wound to the second end of the winding portion from the middle of the winding portion along the axial direction of the high-voltage winding, and a tap is formed in the process of winding the conducting wire and can be used for the dry-type transformer to adjust voltage according to different operating conditions.

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 front view of a dry-type transformer 20 according to another embodiment of the present application;

fig. 8 is a side view of another embodiment of a dry-type transformer 20 of the present application;

FIG. 9 is a side view of another embodiment of the lower clip member 250 of the present application;

fig. 10 is a perspective view of a bobbin 1310 according to an embodiment of the present application;

FIG. 11 is a cross-sectional view of a support cartridge 1311 in accordance with an embodiment of the subject application;

fig. 12 is a perspective view illustrating a high voltage coil 1320 of an embodiment of the present application wound around a bobbin 1310;

fig. 13 is a schematic perspective view of a high voltage winding 130 according to an embodiment of the present application;

fig. 14 is a perspective view of a tool attachment 101 according to an embodiment of the present application

FIG. 15 is a schematic circuit diagram of a high voltage coil 1320 according to an embodiment of the subject application;

FIG. 16 is a partial cross-sectional view of a high voltage winding 130 according to an embodiment of the present application;

FIG. 17 is a partial cross-sectional view of another embodiment of the high voltage winding 230 of the present application;

FIG. 18 is a partial cross-sectional view of a high voltage winding 330 according to yet another embodiment of the present application;

FIG. 19 is a partial cross-sectional view of a high voltage winding 430 according to yet another embodiment of the present application;

fig. 20 is a schematic perspective view of a bobbin 5310 according to another embodiment of the present application;

FIG. 21 is an enlarged view at H in FIG. 20;

FIG. 22 is a schematic perspective view of another embodiment of a support cylinder 6311 of the present application;

fig. 23 is an enlarged view at J in fig. 22.

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 iron core 110, the low voltage winding 120, and the high voltage winding 130 are coaxially arranged, that is, the axial directions of the three are the same direction. 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.

Meanwhile, the two core clamps 140 at the upper end are located above the high-voltage winding 130 disposed outside the core 110, and the top of the high-voltage winding 130 is provided with a plurality of insulating spacers 1001 for supporting the two core clamps 140 at the upper end and keeping the low-voltage winding 120 and the high-voltage winding 130 at a safe electrical distance from the upper yoke 112. Similarly, the two core clamps 140 at the lower end are located below the high voltage winding 130 outside the core 110, and the top of the two core clamps 140 at the lower end are also provided with a plurality of insulating spacers 1001 for supporting the low voltage winding 120 and the high voltage winding 130 and maintaining a safe electrical distance between the low voltage winding 120 and the high voltage winding 130 and the lower yoke 113. The insulating mat 1001 is made of an insulating material, such as a low shrinkage unsaturated polyester glass fiber reinforced Molding Compound (such as a bulk Molding Compound (DMC)), a Sheet Molding Compound (SMC), or an epoxy resin by injection Molding.

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 bars 123 are made of glass fiber-impregnated epoxy resin or 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.

In another embodiment, as shown in fig. 7-9, the core clip of the dry-type transformer 20 includes two upper clip members 240 and two lower clip members 250, and the upper clip members 240 and the core clip members 140 have the same structure and are made of fiber-reinforced composite material, which will not be described in detail. The two lower clamping pieces 250 are connected and installed on two sides of the iron core 210, specifically two sides of the lower iron yoke 213, through a plurality of screws and bolts which are matched with each other, the bottom of the lower clamping pieces 250 and the ground feet 202 are connected together through bolts, so that a frame structure is formed, then the low-voltage winding and the high-voltage winding are sleeved on the iron core 210 from top to bottom, the bottoms of the low-voltage winding and the high-voltage winding are directly located on the lower clamping pieces 250, and finally, other components are installed.

The difference from the upper clip 240 is that the lower clip 250 is designed as a rectangular hollow pipe, that is, the lower clip 250 is formed by connecting and surrounding four clip structures of a plate structure to form a closed structure, the lower clip 250 needs to bear the gravity of components such as a low-voltage winding and a high-voltage winding, and the structure enables the lower clip 250 to bear higher mechanical strength, and the structure is more stable.

Referring to fig. 8 and 9, two of the four clip members of the lower clip member 250, which are disposed in the vertical direction, are defined as a first clip member 252, and two clip members, which are disposed in the horizontal direction, are defined as a second clip member 253, and the four clip members are connected to each other and enclosed to form a closed rectangular structure. One of the first clamping members 252 is disposed against the lower yoke 213, one of the second clamping members 253 is disposed against the low and high voltage windings, and the other second clamping member 253 is bolted to the ground leg 202. In addition, the first clamping member 252 is arranged to have a larger height along the axial direction of the iron core 210, so that the bottoms of the low-voltage winding and the high-voltage winding are directly located on the second clamping member 253, and meanwhile, a certain gap M is also left between the lower iron yoke 213 and the low-voltage winding and between the lower iron yoke 213 and the high-voltage winding, and the gap M can ensure that the lower ends of the low-voltage winding and the high-voltage winding are respectively kept at a safe electrical distance from the lower iron yoke 213, so that an insulating cushion block can be prevented from being arranged between the lower clamping member 250 and the low-voltage winding and the high-voltage winding, and the cost is saved.

Lower folder 250 is made by fibre reinforced composite, specifically can be made by glass fiber impregnated epoxy, light in weight, insulating properties is good, mechanical strength is high, so low voltage winding and high voltage winding can directly be placed on folder 250 down, need not other supporting pad structures, certain cost has been practiced thrift, product weight has been reduced, the step of adjustment cushion position and direction has more been saved, can save time, promote the assembly efficiency of product, and make dry-type transformer overall structure stability strong, the risk that low voltage winding and high voltage winding aversion and electrical distance change that the defect such as cushion aversion caused in the product transportation has been avoided.

As shown in fig. 10-15, 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. The winding body 1310 comprises a supporting cylinder 1311 and a winding part 1312, wherein the supporting cylinder 1311 is a hollow cylinder, and can be a hollow cylinder, a hollow elliptic cylinder or other hollow cylinders; 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. The axial direction of the winding 1310 is the same direction as the axial direction of the high voltage winding 130.

The winding portion 1312 includes a plurality of winding plates 1313, the plurality of winding plates 1313 being circumferentially and uniformly distributed on the outer circumferential surface of the support tube 1311, each of the winding plates 1313 being disposed along the axial direction of the support tube 1311, the length of the winding plate 1313 along the axial direction of the support tube 1311 being smaller than the length of the support tube 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. 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, 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, so that the high-voltage coil 1320 is symmetrically arranged in the axial direction of the high-voltage winding 130, and the center of gravity of the high-voltage winding 130 is located at the center of the high-voltage winding 130, thereby facilitating the hoisting and transportation of the high-voltage winding 130. 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.

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 mode, the winding grooves 1314 in all the winding plates 1313 are matched in the circumferential direction of the supporting cylinder 1311 in a one-to-one correspondence mode, each section of coil is wound in one corresponding winding groove 1314 on all the winding plates 1313 along the circumferential direction of the supporting cylinder 1311 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 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, may also be a hollow pipe formed by winding, pultrusion, or pultrusion of glass fiber-impregnated epoxy resin, may also be 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. 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 are stacked to form a certain thickness, the thickness 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, but may be other adhesives, but it is required to ensure that the adhesive can firmly bond the supporting tube 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. 10 and 11, the bobbin 1310 further includes two flanges 1315, 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 bobbin 1313 is located at an outer circumferential surface of the bobbin 1310, outer end surfaces of the two ends of the bobbin 1313 abut against the disc surface of the two flanges 1315 facing each other, so as to prevent the bobbin 1313 from being damaged due to a large injection pressure during the process of injecting 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 processed and polished into a disk 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. 10, 12 and 13, 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. 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 changer, and for convenience of description, tap 2, tap 4, and tap 6 are defined as a first tap changer, and tap 3, tap 5, and tap 7 are defined as a second tap changer.

In an application scenario, as shown in fig. 10, 12 and 15, 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. Referring to fig. 12, for convenience, an upper end of the winding portion 1312 is defined as a first end, a 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 corresponding turn of the first winding slot 1314 on all the 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, there is only one pie coil 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 the 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. 15, 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. 13 and 15, 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. 12-14, 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, a lead is wound on the winding body 1310 to form the high-voltage coil 1320, the winding body 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. 14, 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 connected and 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 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. 13 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. 16, which is a partial cross-sectional view of the high-voltage winding 130 coated with the high-voltage insulating layer 1330 taken 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 is spaced from the comb teeth of the winding plate 1313 along the axial direction of the high-voltage winding 130, that is, a pancake coil is disposed between two adjacent comb teeth.

In another embodiment, as shown in fig. 17, 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. 18, 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 groove 3314 of the winding plate 3313 in the axial direction of the support cylinder 3311 is greater than a width of the winding groove 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. 19, 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 an application scenario, as shown in fig. 20-21, the bobbin 5310 is similar to the bobbin 1310, except that the supporting tube 5311 is engaged with the bobbin portion 5312. Specifically, the winding body 5310 further includes an auxiliary member 5316, the auxiliary member 5316 is located at a middle position of the outer circumferential surface of the support tube 5311 and extends outward in the radial direction of the support tube 5311, such that the auxiliary member 5316 surrounds the support tube 5311 for a circle to form an annular disk surface. The winding plate 5313 or the auxiliary member 5316 is provided with a slot, and the winding plate 5313 and the auxiliary member 5316 are connected in a clamping manner through the slot. In this embodiment, each of the winding boards 5313 is provided with a first engaging groove 53131, and the positions of the first engaging groove 53131 and the auxiliary member 5316 are correspondingly matched, so that the auxiliary member 5316 is engaged in each of the first engaging grooves 53131.

The longer side of the wire winding plate 5313 is disposed along the axial direction of the support cylinder 5311, and the plurality of wire winding grooves 5314 are disposed along the radial direction of the support cylinder 5311 and are spaced apart from each other along the axial direction of the support cylinder 5311, so that the wire winding plate 5313 forms a plurality of comb teeth. The first engaging groove 53131 is located on the winding plate 5313 and opposite to the winding groove 5314, that is, the first engaging groove 53131 is located along the radial direction of the supporting cylinder 5311, and the first engaging groove 53131 is located on the side of the winding plate 5313 close to the supporting cylinder 5311, so that the auxiliary member 5316 protruding the outer circumferential surface of the supporting cylinder 5311 can be engaged with the first engaging groove 53131. The auxiliary member 5316 can keep the stable arrangement of the winding plate 5313, thereby preventing the movement and dislocation of the winding plate 5313 during the wire winding process and the high-voltage insulation layer injection process.

The first engaging groove 53131 is located at the middle of the winding plate 5313, and in the radial direction of the supporting cylinder 5311, the first engaging groove 53131 extends from the side of the winding plate 5313 close to the supporting cylinder 5311 to one comb at the middle of the winding plate 5313; or in the radial direction of the supporting cylinder 5311, the first engaging groove 53131 is flush with one comb tooth at the middle position of the winding plate 5313 but does not extend to the comb tooth. On one hand, the first clamping groove 53131 is prevented from being arranged flush with the winding groove 5314 to influence the mechanical strength of the winding plate 5313, and even the winding plate 5313 is prevented from being broken under stress; on the other hand, the teeth of the comb teeth at the middle position of the winding plate 5313 are relatively high, so that the mechanical strength of the winding plate 5313 can be further prevented from being affected after the first clamping groove 53131 is arranged. Meanwhile, the groove depth of the first clamping groove 53131 in the radial direction of the supporting cylinder 5311 is matched with the width of the auxiliary part 5316 protruding out of the supporting cylinder 5311, so that after the auxiliary part 5316 and the winding board 5313 are assembled, the outer side face of the auxiliary part 5316 is tightly attached to the inner side face of the first clamping groove 53131, the mechanical strength is good, and the fastening is reliable. If the groove depth of the first engaging groove 53131 is smaller than the width of the auxiliary member 5316 protruding out of the supporting cylinder 5311, a gap is left between the winding plate 5313 and the supporting cylinder 5311, and there is a risk that the winding plate 5313 bends around the auxiliary member 5316 during the wire winding process and the high-voltage insulation layer injection process; if the depth of the first engaging groove 53131 is greater than the width of the auxiliary member 5316 protruding out of the supporting cylinder 5311 and a gap is left between the first engaging groove 53131 and the auxiliary member 5316, the auxiliary member 5316 cannot be fastened.

The auxiliary 5316 is made of glass fiber impregnated epoxy resin, a disc member with a certain thickness is formed by die pressing, and then the auxiliary 5316 is fixedly connected to the outer circumferential surface of the support cylinder 5311 by an adhesive, so that the material consumption is minimized, and the cost can be saved. Of course, the auxiliary member may be formed integrally with the support cylinder by forming a hollow tube with a large thickness and then turning the hollow tube to form the winding plate 5313 and the auxiliary member 5316 at the same time.

In this embodiment, the auxiliary member 5316 and the first engaging groove 53131 are correspondingly disposed in one group, and in other embodiments, the auxiliary member and the first engaging groove may also be disposed in two or three groups at intervals along the axial direction of the supporting cylinder, at this time, the auxiliary members and the first engaging grooves in each group are distributed at intervals along the axial direction of the supporting cylinder, so that the bearing strength of the winding board is effectively and uniformly distributed, and the structure of the winding board is more stable. For example, in one embodiment, the auxiliary members are respectively disposed at the middle and two ends of the outer circumferential surface of the supporting cylinder, and three first clamping grooves are correspondingly disposed on each winding plate.

In another application scenario, as shown in fig. 22 to 23, different from the supporting cylinder 5311, a plurality of second locking grooves 63161 are formed in the auxiliary member 6316 on the outer circumferential surface of the supporting cylinder 6311, and the plurality of second locking grooves 63161 are uniformly distributed in the circumferential direction of the auxiliary member 6316, that is, the plurality of second locking grooves 63161 correspond to the plurality of winding boards in a matching manner. At this moment, need not to set up the draw-in groove on the winder, the winder can directly block and establish in second draw-in groove 63161, can keep the firm setting of winder, has avoided the removal dislocation of wire winder in-process and high-pressure insulation layer injection in-process winder to can avoid setting up the draw-in groove on the winder, thereby avoid influencing the mechanical strength of winder. The auxiliary member 6316 is made of the same material and formed in the same manner as the auxiliary member 5316, and will not be described herein again.

In other embodiments, the winding body may only include the winding portion, the winding portion includes a plurality of comb-shaped winding boards and auxiliary components, the plurality of winding boards are circumferentially disposed inside the high-voltage winding, i.e., the winding body does not include a supporting cylinder, i.e., the winding body does not include a rigid insulating liner, so that the high-voltage winding has a better heat conduction effect, and an interface between the high-voltage insulating layer and the rigid insulating liner is eliminated, thereby suppressing surface discharge of the rigid insulating liner, saving materials, and reducing cost.

The auxiliary member includes at least one tip auxiliary member, and the tip auxiliary member sets up in a plurality of winder plates along the axial tip outside of winding body, and the tip outside of winder plate sets up the recess, and in the tip auxiliary member embedding recess, the effective connection of tip auxiliary member and winder plate has been guaranteed. The groove is located on the comb tooth side of the winding plate, namely on the side, away from the axle center of the high-voltage winding, of the winding plate, so that the end auxiliary piece can fix the winding plate better.

The groove depth of the groove is larger than or equal to the thickness of the end part auxiliary piece, so that glue liquid coats the end part of the winding plate and the end part auxiliary piece when glue is injected, and the connection failure of the winding plate and the end part auxiliary piece is not easily caused by the influence of external force. The end auxiliary part is fixedly connected in the groove through the adhesive, the adhesive is double-component high-temperature-resistant epoxy glue, and other adhesive glues can be adopted, but the adhesive needs to be guaranteed to enable the end auxiliary part to be firmly bonded with the winding board, and the end auxiliary part is high-temperature-resistant and is coated on the peripheries of the winding board and the end auxiliary part in a high-pressure insulation layer adopting a high-temperature injection mode. Of course, the end fitting can also be matched exactly to the dimensions of the recess, so that the end fitting snaps into the recess without adhesive fixing.

In this embodiment, both ends outsides of the winding board are provided with the end auxiliary member, so that both ends of the winding board are fixed by the auxiliary member, and the stable arrangement of the winding board can be effectively maintained. In other embodiments, an end auxiliary member may be provided only outside one of the ends of the winding plate.

The auxiliary member still includes middle part auxiliary member, when enclosing the wire winding board into the cavity, a side surface definition for the inner wall of cavity formation is the inner wall of wire winding board, and middle part auxiliary member sets up in the inner wall of wire winding board, can not influence the coiling of wire winding board broach side wire. The middle auxiliary member is disposed in the same manner as the auxiliary member 5316, and will not be described herein.

The beneficial effect of this application is: be different from prior art's condition, the high-voltage winding of the dry-type transformer of this application includes bobbin, high-voltage coil and high temperature silicon sulfide rubber's high-pressure insulation layer, compares the epoxy high-pressure insulation layer among the prior art, and the high-pressure insulation layer of this application high temperature silicon sulfide 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 effectively 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 silicone rubber is formed by integral high-temperature vulcanization injection molding, the process method enables the high-voltage insulating layer to be more stable, the mechanical property to be higher, the bonding performance with the high-voltage coil and the winding body to be better, and the service life of the high-voltage insulating layer can be effectively prolonged. 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 dry-type transformer is characterized by comprising an iron core, a low-voltage winding and a high-voltage winding, wherein the low-voltage winding is sleeved outside the iron core, and the high-voltage winding is sleeved outside the low-voltage winding; the high-voltage winding comprises a winding body, a high-voltage coil and a high-voltage insulating layer, a wire is wound on the winding body to form the high-voltage coil, the high-voltage insulating layer is filled in a gap between the high-voltage coil and the winding body and at two ends of the winding body, and the high-voltage insulating layer is high-temperature vulcanized silicone rubber.

2. A dry-type transformer as claimed in claim 1, wherein said bobbin includes a winding portion, said winding portion includes a plurality of circumferentially disposed winding plates, and said winding plates are formed with a plurality of winding grooves for forming a plurality of comb teeth on said winding plates.

3. A dry type transformer as claimed in claim 2, wherein the height of said comb teeth in the axial direction of said high voltage winding is defined as a tooth height, and the tooth height of said comb teeth in the middle of said bobbin and the tooth height of said comb teeth at both ends of said bobbin are each larger than the tooth height of said comb teeth at the other portion of said bobbin, so that said bobbin is formed with 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 in order from one end toward the other end in the axial direction of said high voltage winding.

4. A dry-type transformer as claimed in claim 3, wherein the first and third high comb-tooth regions are symmetrically disposed with respect to the second high comb-tooth region, and the first and second low comb-tooth regions are symmetrically disposed with respect to the second high comb-tooth region.

5. A dry-type transformer as claimed in claim 2, wherein said bobbin further comprises an auxiliary member, said auxiliary member being engaged with said plurality of said winding plates.

6. A dry-type transformer as claimed in claim 2, wherein said bobbin further comprises a supporting cylinder, said supporting cylinder being a hollow cylinder, a plurality of said winding plates being circumferentially and uniformly distributed on an outer circumferential surface of said supporting cylinder, a length direction of each of said winding plates being arranged along an axial direction of said supporting cylinder.

7. A dry type transformer as claimed in claim 5, wherein the auxiliary members include a middle auxiliary member provided to an inner wall of the bobbin plate and end auxiliary members provided to outer sides of ends of the bobbin plate.

8. A dry-type transformer as claimed in claim 2, wherein said high voltage coil includes a plurality of coil segments, said wire is wound in said winding slots such that a plurality of said coil segments are arranged at intervals along an axial direction of said high voltage winding, and at least one of said coil segments is arranged between two adjacent ones of said comb teeth on said winding plate.

9. A dry-type transformer as claimed in claim 8, wherein each of said coils is wound in a layer-like reciprocating manner in an axial direction of said high voltage winding and is formed in a closely arranged spiral shape on an outer peripheral surface of said winding body.

10. A dry transformer as claimed in claim 9, wherein said coil is provided with at least one interlayer insulating layer along an axial direction of said high voltage winding, said interlayer insulating layer being an insulating strip having a wave-shaped edge.

11. A dry-type transformer as claimed in claim 1, wherein said core is provided with four core clamps at the outside thereof, said core clamps being made of a fiber-reinforced composite material.

12. A dry transformer as claimed in claim 11, wherein the core clip is molded or pultruded from a fibrous material impregnated epoxy resin.

13. A dry-type transformer as claimed in claim 1, wherein the low voltage winding includes a copper foil and low voltage insulating layers, the copper foil and the low voltage insulating layers being alternately arranged.

14. A dry transformer as claimed in claim 13, wherein said low voltage insulation layer is SHS-P diphenyl ether prepreg or silicone rubber film.

15. A dry-type transformer as claimed in claim 13, wherein at least one heat dissipating air passage is provided in the low voltage winding, the heat dissipating air passage being located between the copper foil and the low voltage insulation layer.

16. A dry-type transformer as claimed in claim 2, wherein said conductive wire comprises a first conductive wire wound from a first end of said winding portion to a middle portion of said winding portion in an axial direction of said high voltage winding, and a second conductive wire wound from said middle portion of said winding portion to a second end of said winding portion in an axial direction of said high voltage winding.