CN220672371U - High-voltage winding and dry-type transformer - Google Patents

Abstract

The utility model discloses a high-voltage winding, which comprises a winding body, a high-voltage coil, a high-voltage insulating layer and an external insulating layer, wherein a wire is wound on the winding body to form the high-voltage coil, two external connections are formed at two ends of the wire, the high-voltage insulating layer wraps the high-voltage coil and the winding body, the external insulating layer wraps the external side wall, and the external insulating layer and the high-voltage insulating layer are integrally injection molded. The utility model also discloses a dry-type transformer. The external insulating layer and the high-voltage insulating layer of the high-voltage winding are integrally formed, so that the high-voltage winding is better in tightness, short in processing period and low in manufacturing cost.

Description

High-voltage winding and dry-type transformer

Technical Field

The utility model relates to the field of dry-type transformer manufacturing, in particular to a high-voltage winding and a dry-type transformer.

Background

The wire outlet end of the high-voltage winding of the traditional silicone rubber dry-type transformer needs to be connected with a wire outlet sleeve, a heat shrinkage tube and other structures so as to avoid the discharge problem of the wire outlet end. The outlet sleeve is generally of a structure that an epoxy resin insulating layer is cast by adopting a conductive copper rod or a liquid silicone rubber umbrella skirt is cast after the conductive copper rod is reinforced by adopting a glass fiber reinforced plastic cylinder, but the structure cannot be integrally formed with the insulating layer of the high-voltage winding, a sealing structure is required to be designed, and the problem of sealing failure exists; the heat shrinkage pipe is usually made of PVC, PEC and other materials for encapsulating the wire outlet end, but sealing cannot be completely realized, and rainwater can corrode a conductor after penetrating into the heat shrinkage pipe, so that the insulating property of a product is affected. In addition, the above structures all require additional machining and overall assembly, with long machining cycles.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model aims to provide a high-voltage winding so as to solve the problem of sealing failure of the wire outlet end of the existing high-voltage winding.

In order to achieve the above purpose, the technical means adopted by the utility model are as follows: the utility model provides a high-voltage winding, includes the wire winding body, high-voltage coil, high-voltage insulation layer, external insulating layer, and the wire coiling forms high-voltage coil on the wire winding body, and two external connection are formed at the both ends of wire, and high-voltage insulation layer parcel high-voltage coil and wire winding body, external insulating layer parcel external lateral wall, external insulating layer and the integrative injection moulding of high-voltage insulation layer. The interface caused by different materials between the high-voltage insulating layer and the external insulating layer is avoided, the problems of no water vapor permeation and the like are solved, the tightness is better, the time for independently preparing the external insulating layer is saved in the integrated forming process, the processing period is short, the cost and the manufacturing energy consumption are reduced, and the overall cost is lower.

Preferably, the external connection is also connected with a central conductor, the central conductor is used for supporting the external connection, and the external connection insulating layer wraps the external connection and the central conductor. The center conductor can prevent the external receiving force from deforming in the forming process of the external insulation layer, so that the external insulation layer cannot completely wrap the external connection.

Preferably, the external connection and the central conductor are connected by welding. The connection strength can be ensured.

Preferably, the external insulation layer comprises a sheath and a plurality of umbrella skirts, the sheath is arranged on the external periphery, and the umbrella skirts are arranged on the periphery of the sheath at intervals. Through setting up the full skirt, increased creepage distance, can avoid high-voltage winding to take place partial discharge in long-term operation the insulating degradation problem that leads to of external surface, effectively promote dry-type transformer's anti-pollution flashover ability.

Preferably, the winding body comprises a plurality of winding plates, the wire is wound on the winding plates to form a high-voltage coil, a plurality of comb teeth are arranged on the winding plates, and the winding plates are uniformly distributed along the circumferential direction of the high-voltage coil. The coil is wound on the comb-shaped winding plate, so that the coil is more stable and can be prevented from shifting.

Preferably, the high-voltage coil comprises a plurality of coils, and at least one coil is arranged between two adjacent comb teeth on the winding plate.

Preferably, the winding body further comprises a plurality of auxiliary pieces, the auxiliary pieces are annular and are arranged at intervals along the axial direction of the high-voltage winding, and the auxiliary pieces are connected with the winding board in a clamping mode.

Preferably, the external insulation layer and the high-voltage insulation layer are both made of high-temperature vulcanized silicone rubber. The high-temperature vulcanized silicone rubber has better fireproof performance, low-temperature resistance, ageing resistance and short-circuit resistance test capability.

Preferably, the high voltage insulating layer fills a gap between the high voltage coil and the winding body and both ends of the winding body.

In order to achieve the above object, another technical scheme adopted by the present utility model is as follows: a dry-type transformer comprises an iron core, a low-voltage winding and the 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 beneficial effects of the utility model are as follows: the external lateral wall of external insulating layer parcel is adopted to the high-voltage winding of this application, and external insulating layer and the integrative injection moulding of high-voltage insulating layer for there is not the interface that the material is different between high-voltage insulating layer and the external insulating layer leads to, no steam infiltration scheduling problem, the leakproofness is better, and integrated into one piece technology has saved the time of separately preparing external insulating layer, and processing cycle is short, reduces cost of labor and manufacturing power consumption, and overall cost is lower.

Meanwhile, by arranging the umbrella skirt, the creepage distance is increased, the problem of insulation degradation caused by partial discharge of the outer surface of the high-voltage winding in long-term operation can be avoided, and the pollution flashover resistance of the dry-type transformer is effectively improved.

In addition, through setting up the outside protrusion certain distance of center conductor from the surface on high voltage insulation layer, and then can provide longer dry arc distance through the setting of external insulating layer, effectively promote dry-type transformer's lightning protection ability.

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 top 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 in fig. 2;

FIG. 5 is a schematic perspective view of a bobbin 1310 according to an embodiment of the present disclosure;

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

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

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

FIG. 9 is a simplified electrical schematic diagram of a high voltage coil 1320 of an embodiment of the present application;

fig. 10 is a schematic perspective view of a winding portion 2310 according to an embodiment of the present application;

FIG. 11 is a schematic perspective view of an assist member 2312 according to an embodiment of the present application;

fig. 12 is a schematic perspective view of a high voltage winding 130 according to another embodiment of the present application;

fig. 13 is another view of the high voltage winding 130 shown in fig. 12;

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

Detailed Description

As required, specific embodiments of the present utility model will be disclosed herein. However, it is to be understood that the embodiments disclosed herein are merely exemplary of the utility model, which 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 utility model in virtually any appropriately manner, including employing the various features disclosed herein in connection with features that may not be explicitly disclosed.

As shown in fig. 1-3, the dry-type transformer 10 is a three-phase transformer, a-phase, B-phase and C-phase, respectively, 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 are symmetrically constructed. 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 in a linear configuration, and dry-type transformer 10 includes a core 110, three low voltage windings 120, and three high voltage windings 130. The iron core 110 includes three columnar iron core bodies 111, an upper yoke 112 located at the upper ends of the three columnar iron core bodies 111, and a lower yoke 113 located at the lower ends of the three columnar iron core bodies 111, the three low-voltage windings 120 are respectively sleeved on the peripheries of the three columnar iron core bodies 111, and the three high-voltage windings 130 are respectively sleeved on the peripheries of the three low-voltage windings 120, i.e. the three columnar iron core bodies 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 stacking a plurality of layers of silicon steel sheets, binding and fixing are performed on the plurality of layers of silicon steel sheets by using binding tapes, and the radial section of the columnar iron core body 111 is approximately elliptical or circular or other shapes, so long as the columnar iron core body can be accommodated in the hollow cavity of the low-voltage winding 120, and the columnar iron core body is not limited herein. The upper yoke 112 and the lower yoke 113 are also formed by stacking a plurality of silicon steel sheets, and the three columnar iron cores 111 are fixedly connected, thereby forming a three-phase iron core 110 as shown in fig. 3.

The outer side of the iron core 110 is provided with an iron core clamping member 140, and the iron core clamping member 140 is used for clamping the iron core 110. The core clamping member 140 may be a channel steel member or a hollow pipe member, which is not limited herein. The number of the iron core clamping pieces 140 is four, wherein two iron core clamping pieces 140 are symmetrically positioned on two sides of the upper end of the iron core 110 and above the high-voltage winding 130; the other two core clamps 140 are symmetrically located at both sides of the lower end of the core 110 and below the high voltage winding 130.

As shown in fig. 2 and 4, the low voltage winding 120 includes a copper foil 121, a low voltage insulation layer 122, and a support bar 123, and the copper foil 121 and the low voltage insulation layer 122 are alternately arranged. The copper foil 121 is formed by winding a 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 alternating arrangement of the copper foil 121 and the low-voltage insulating layer 122 is realized.

At least one heat dissipation air passage is arranged in the low-voltage winding 120, and the heat dissipation air passage is positioned between the adjacent copper foil 121 and the low-voltage insulating layer 122, and a supporting bar 123 is positioned in the heat dissipation air passage and used for supporting and isolating the adjacent copper foil 121 and the low-voltage insulating layer 122.

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

The insulating support bar 123 is made of glass fiber-impregnated epoxy resin or aramid fiber-impregnated epoxy resin, which is not limited herein. The insulating support bar 123 is a long bar with an i-shaped cross section, and has more stable mechanical strength. Of course, the insulating support bar may be a strip with a square cross section or other shapes, so long as the insulating support bar can play a role in supporting and isolating.

As shown in fig. 5-9, the high voltage winding 130 includes a winding body 1310, a high voltage coil 1320, and a high voltage insulation 1330, and a wire is wound on the winding body 1310 to form the high voltage coil 1320. Specifically, the winding body 1310 includes a support cylinder 1311 and a winding portion 1312, where the support cylinder 1311 is a hollow cylinder, may be a hollow elliptic cylinder, or may be other hollow cylindrical body; the winding portion 1312 is located on an outer peripheral surface of the support cylinder 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 coils arranged at intervals in an axial direction of the support cylinder 1311.

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

The winding plate 1313 is a rectangular plate, the longer side edge of the winding plate 1313 is arranged along the axial direction of the supporting cylinder 1311, a plurality of winding grooves 1314 are further formed in the winding plate 1313, the plurality of winding grooves 1314 are arranged along the radial direction of the supporting cylinder 1311 and are distributed at intervals along the axial direction of the supporting cylinder 1311, and the winding plate 1313 is in a comb shape, namely a plurality of comb teeth are formed on the winding plate 1313. The height of the comb teeth on the winding plate 1313 along the axial direction of the supporting cylinder 1311 is defined as tooth height, the tooth heights of the comb teeth at two ends of the winding plate 1313 and the tooth heights of the comb teeth at the middle part of the winding plate 1313 are larger than those of the comb teeth at other parts, because the field intensity at the end parts of the high-voltage coil 1320 is uneven, the tooth heights at two ends of the winding plate 1313 are set to be larger than a bit so as to uniformly apply an electric field, a tap for split wires needs to be led out at the middle part of the winding plate 1313, the tooth heights at the middle part of the winding plate 1313 are set to be larger than a bit, the distance between two corresponding adjacent winding grooves 1314 is larger, and a placing space can be reserved for the tap led out from the middle part of the winding plate 1313.

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

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

In other embodiments, the coil plate may also be an annular disk 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 wire is wound in the groove formed by two adjacent winding plates.

The support cylinder 1311 is a hollow tube formed by winding, solidifying, or pultrusion glass fiber impregnated epoxy resin, a hollow tube formed by winding, extruding, or winding glass fiber or aramid fiber impregnated epoxy resin, a hollow tube formed by winding, solidifying, or pultrusion aramid fiber impregnated epoxy resin, or a hollow tube formed by adopting other composite materials, which is not limited herein.

The winding body 1310 may be formed by separately molding the support cylinder 1311 and the winding plate 1313 and then fixed by bonding, or may be formed by integrally casting a hollow pipe at one time and then turning the hollow pipe.

In an application scenario, as shown in fig. 5, 6 and 8, the winding body 1310 further includes two flanges 1315, the flanges 1315 are located at two ends of the supporting cylinder 1311 and extend outwards along the radial direction of the supporting cylinder 1311 to form an annular disc surface, the flanges 1315 at two ends are oppositely arranged, when the winding plate 1313 is placed on the outer peripheral surface of the winding body 1310, the outer end surfaces of the two ends of the winding plate 1313 abut against the disc surfaces facing each other of the two flanges 1315, so that the winding plate 1313 is prevented from being damaged due to larger injection pressure in the process of injecting the high-voltage insulating layer 1330.

In another embodiment, as shown in fig. 10-11, the winding body may only include the winding portion 2310, that is, the winding body is not provided with a supporting cylinder, that is, the winding body omits a structure of the rigid insulating lining cylinder, so that the heat conduction effect of the high-voltage winding is better, and the interface between the high-voltage insulating layer and the rigid insulating lining cylinder is eliminated, thereby inhibiting the surface discharge of the rigid insulating lining cylinder, saving materials and reducing cost.

Specifically, the winding portion 2310 includes a plurality of comb-shaped winding plates 2311 and a plurality of auxiliary members 2312, the plurality of auxiliary members 2312 are annular and are disposed at intervals along an axial direction of the auxiliary members 2312, the winding plates 2311 are fixed on an outer periphery of the plurality of auxiliary members 2312 along the axial direction of the auxiliary members 2312, the winding plates 2311 are simultaneously connected with all the auxiliary members 2312, and the plurality of winding plates 2311 are uniformly distributed along a circumferential direction of the auxiliary members 2312. The axial direction of the auxiliary member 2312 is the axial direction of the winding portion 2310, i.e., the axial direction of the high-voltage winding. The auxiliary member 2312 may be annular or elliptical, and may be designed according to the overall shape of the high-voltage winding. The plurality of winding plates 2311 are circumferentially arranged, the wire is wound on the winding part 2310 to form a high-voltage coil, the high-voltage coil comprises a plurality of coils, the plurality of coils are arranged at intervals along the axial direction of the high-voltage winding, and the high-voltage insulating layer wraps the high-voltage coil, the plurality of auxiliary pieces 2312 and the winding plates 2311. The auxiliary member 2312 can maintain the stable arrangement of the winding plate 2311, and prevent the movement dislocation of the winding plate 2311 during the wire winding process and the injection process of the high-voltage insulation layer.

In an embodiment, the outer surface of the auxiliary member 2312 is provided with a plurality of first clamping grooves 23121, a plurality of first clamping grooves 23121 are uniformly arranged along the circumferential direction of the auxiliary member 2312, and the side surfaces of the plurality of winding plates 2311 are respectively and correspondingly clamped in the plurality of first clamping grooves 23121, so that the plurality of winding plates 2311 are uniformly distributed on the circumferential direction of the plurality of auxiliary members 2312; all the winding plates 2311 are arranged at the two ends of the winding plate 2311 in parallel, and the first clamping grooves 23121 on all the auxiliary pieces 2312 are matched in a one-to-one correspondence manner in the axial direction of the auxiliary pieces 2312, so that each winding plate 2311 can be arranged along the axial direction of the auxiliary piece 2312, and then a wire is wound in the comb teeth on the winding plate 2311 to form a high-voltage coil, namely a plurality of sections of coils of the high-voltage coil are distributed at intervals in the axial direction of the winding part 2310, and the high-voltage coil is balanced in stress and good in mechanical strength.

The width of the first clamping groove 23121 along the circumferential direction of the auxiliary member 2312 is defined as the groove width of the first clamping groove 23121, and the groove width of the first clamping groove 23121 is matched with the thickness of the winding plate 2311, so that the winding plate 2311 and the auxiliary member 2312 are firmly assembled, and the problem that the winding plate 2311 is difficult to align and fix on the auxiliary member 2312 when the groove width of the first clamping groove 23121 is smaller than the thickness of the winding plate 2311 or the winding plate 2311 falls off from the outside of the auxiliary member 2312 when the groove width of the first clamping groove 23121 is larger than the thickness of the winding plate 2311 is avoided. The winding plate 2311 is fixedly connected in the first clamping groove 23121 through an adhesive, the adhesive is a bi-component high-temperature-resistant epoxy adhesive, and of course, other adhesives can be used, but the adhesive needs to be ensured to enable the winding plate 2311 and the auxiliary piece 2312 to be firmly bonded, and the adhesive needs to be high-temperature-resistant, so that the winding plate 2311 and the auxiliary piece 2312 are coated in a high-temperature injection mode to adapt to a high-voltage insulating layer.

In other embodiments, a slot may be formed in a side surface of the winding board, which is close to the auxiliary member, and the auxiliary member may be clamped in the slot of the winding board, so that the winding board is fixedly connected with the auxiliary member. Of course, in the foregoing embodiment, it is preferable to provide the first catching groove 23121 on the auxiliary member 2312 to avoid the mechanical strength of the winding plate from being impaired by the catching groove being opened on the winding plate.

The winding plate 2311 is a comb plate 2311, and the comb plate 2311 has a similar structure to the winding plate 1313, except that two ends of the comb plate 2311 are provided with circulation grooves 23111, so that the injected silicone rubber raw material can flow into the inner side of the winding part 2310 from the end of the winding part 2310 in the injection molding process of the high-voltage insulating layer, and further the high-voltage insulating layer fully fills the gap between the winding part 2310 and the high-voltage coil and two ends of the winding part 2310.

The winding plate 2311 and the auxiliary member 2312 are both made of glass fiber impregnated epoxy resin, are laminated to a certain thickness after being impregnated with epoxy resin by a plurality of layers of glass fiber cloth, and are molded and cured to form a glass fiber reinforced plastic member. In the present embodiment, the winding plate 2311 and the auxiliary member 2312 are separately molded and then adhered and fixed. In other embodiments, the winding plate and the auxiliary member may be integrally formed.

Referring to fig. 5, 7 and 8, taking the a-phase transformer 100 as an example, a wire is wound around the outer circumferential surface of the winding body 1310 to form a high-voltage coil 1320. Specifically, the wire is wound in the winding slot 1314 of the winding portion 1312, such that the high-voltage coils 1320 are spaced apart in the axial direction of the supporting cylinder 1311, and the wire forms two external connections, namely, a first external connection D and a second external connection X, after the winding is completed, respectively, 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 interconnection with each phase change transformer. The wire is led out of six taps, tap 2, tap 3, tap 4, tap 5, tap 6 and tap 7, respectively, in the middle of the wire body 1310 in the axial direction thereof, the six taps forming tap switches, tap 2, tap 4 and tap 6 being defined as a first tap switch and tap 3, tap 5 and tap 7 being defined as a second tap switch for convenience of description.

In an application scenario, as shown in fig. 5 and fig. 7-9, the wires include a first wire and a second wire, the first wire and the second wire are continuous wires, and the first wire and the second wire are covered with an insulating layer, where the insulating layer may be a polyimide film or a glass fiber film, or the insulating layer may be another insulating material such as polyester paint, or may be a combination of multiple insulating materials, which is not limited herein. The first 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 winding body 1310, and three taps are drawn. For convenience of description, the upper end of the winding portion 1312 is defined as a first end, the lower end of the winding portion 1312 is defined as a second end, the first wire is wound from the first end of the winding portion 1312 to the second end of the winding portion 1312, and 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 1321, the first coil 1321 is a pancake winding method, and only one pancake coil is disposed in each winding slot 1314, and at this time, only one pancake coil is disposed in each section of coil. The first wire is located at the inner turn wire end of the first end of the winding portion 1312 to form a first external connection D exposed outside the high voltage insulation layer 1330, that is, the first external connection D is led out at the inner turn wire end of the first section coil 1321 (i.e., the head end of the first wire), the outer turn wire end of the first section coil 1321 extends to a corresponding turn of the second winding slot 1314 on all winding plates 1313 to form a second section coil 1322, and so on until the first wire is wound to the middle of the winding body 1310, and three taps, that is, tap 6, tap 4 and tap 2 as shown in fig. 12, are led out through the outer turn wire ends of the three sections of coils, respectively, so that the first wire is wound.

The second 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 winding body 1310, and is led out of the other three taps. Specifically, the second wire starts winding in the next winding slot 1314 adjacent to the tap 2, forming the third segment coil 1323, continues to wind toward the second end of the winding portion 1312 in the same winding manner as the first wire, and three further taps, i.e., tap 3, tap 5 and tap 7, are respectively led out from the three segments of coils starting from the third segment coil 1323 until the second wire winds to the corresponding one of the last winding slots 1314 on each winding plate 1313 at the second end of the winding portion 1312 and forms the terminal segment coil 1324. The outer turn wire end of the second wire at the second end of the winding portion 1312 forms a second external connection X exposed to the outside of the high voltage insulation 1330, that is, the second external connection X is led out at the outer turn wire 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 corresponding winding grooves 1314 on all the winding plates 1313 are wound, so that each section of coil formed by winding the wire is perpendicular to the axial direction of the winding body 1310, the winding is convenient, the wire arrangement is neat, the stress of the winding plates 1313 is uniform, and the mechanical strength is good. In other embodiments, other existing wire winding methods may be selected according to the design requirements of the high-voltage winding, and are not particularly limited herein.

As shown in fig. 8, the high voltage winding 130 is formed by wrapping the high voltage coil 1320 and the winding body 1310 with the high voltage insulating layer 1330. The high-voltage insulating layer 1330 is high-temperature vulcanized silicone rubber, a wire is wound on the winding body 1310 to form a 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 integrally injection molded on the periphery of the body to be injected by adding silicone rubber raw materials, so that the high-voltage winding 130 is obtained. The high-voltage insulating layer 1330 adopts high-temperature vulcanized silicone rubber, so that the insulating performance and mechanical performance of the high-voltage winding 130 are integrally improved.

The high-temperature vulcanized silicone rubber adopts a high-temperature vulcanized silicone rubber material system, and specifically comprises raw rubber, a reinforcing agent, a flame retardant, a heat resistant agent and other auxiliary materials.

After the high-temperature vulcanized silicone rubber is injected in a vacuum manner to cover the high-voltage coil 1320 and the winding body 1310, the high-temperature vulcanized silicone rubber fills the gap between the high-voltage coil 1320 and the winding body 1310 and covers the two ends of the winding body 1310, and the high-temperature vulcanized silicone rubber does not cover the inner wall of the supporting cylinder 1311, so that the high-voltage winding 130 is in a hollow column shape as a whole, and can be a hollow cylinder, a hollow elliptic cylinder or other hollow column bodies.

Compared with the epoxy resin high-voltage insulating layer in the prior art, the silicon rubber has the following advantages: 1) The dry-type transformer 10 has better fireproof performance, low-temperature resistance, ageing resistance and short-circuit resistance test capability, and can prolong the service life of the dry-type transformer 10; 2) The copper coil is easy to peel from the silicon rubber, the material recovery rate is more than 99%, and the copper coil is more environment-friendly; 3) The silicon rubber elastomer can weaken the partial discharge induction caused by mechanical vibration, has an inhibition effect on equipment discharge, and the silicon rubber product is non-conductive silicon dioxide under the discharge effect, so that insulation continuous degradation can be effectively inhibited; 4) The operation loss of the dry type transformer 10 can be reduced, and the energy is saved; 5) The ability of resistant adverse circumstances is better, can install indoor and open air. Meanwhile, compared with the existing room temperature vulcanization, the process method ensures that the high-voltage insulating layer 1330 is firmer and higher in mechanical property and better in bonding property with the high-voltage coil 1320 and the winding body 1310 by integral high-temperature vulcanization injection molding, and can effectively prolong the service life of the high-voltage insulating layer 1330. And compared with liquid silicone rubber, the high-temperature vulcanized silicone rubber filler is uniformly dispersed, so that partial discharge of the dry-type transformer 10 caused by filler agglomeration is avoided, and the overall performance of the dry-type transformer 10 is better.

Further, as shown in fig. 12-13, the high voltage winding 130 includes an external insulation layer 1340, where the external insulation layer 1340 wraps the two external sidewalls, i.e., the external insulation layer 1340 wraps the sidewalls of the first external connection D and the second external connection X, respectively.

The external insulation layer 1340 comprises a sheath 1341 and a plurality of umbrella skirts 1342, wherein the sheath 1341 is arranged at the periphery of the external connection, namely, the sheath 1341 is respectively arranged at the periphery of the first external connection D and the second external connection X, and the umbrella skirts 1342 are arranged at the periphery of the sheath 1341 at intervals.

In this embodiment, the size of the plurality of sheds 1342 is equal, i.e. all sheds 1342 extend outwardly from the outer surface. By arranging the umbrella skirts 1342, the creepage distance of the outer surface of the high-voltage winding 130 is increased, the problem of insulation degradation caused by partial discharge of the outer surface of the high-voltage winding 130 in long-term operation can be avoided, the pollution flashover resistance of the dry-type transformer 10 is effectively improved, and the stable and safe operation of the dry-type transformer 10 is ensured.

In other embodiments, the size and shape of the umbrella skirt can be adjusted according to the design requirement of the high-voltage winding, for example, the umbrella skirt can be designed in an alternating mode by adopting a large umbrella skirt and a small umbrella skirt, namely, the umbrella skirt comprises a plurality of small umbrella skirts and a plurality of large umbrella skirts, the extending length of the small umbrella skirts from the external outer surface is smaller than the extending length of the large umbrella skirts from the external outer surface, the small umbrella skirts and the large umbrella skirts can be alternately arranged at intervals along the axial direction of the external connection, and the specific arrangement sequence and interval distance of the large umbrella skirts and the small umbrella skirts can be adjusted according to the design requirement of the high-voltage winding. The structure with the alternate design of the large umbrella skirt and the small umbrella skirt has good self-cleaning property and is suitable for areas with serious pollution.

The first external connection D and the second external connection X are also respectively connected with a central conductor (not shown), wherein the central conductor is used for supporting the external connection, and the external insulation layer 1340 wraps the central conductor. The first external connection D and the second external connection X are supported by the central conductor, so that the first external connection D and the second external connection X can be prevented from being deformed under stress in the forming process of the external connection insulating layer 1340, and the external connection insulating layer 1340 cannot completely wrap the first external connection D and the second external connection X.

In the embodiment, the central conductor is made of a metal material, and the external connection and the central conductor are connected in a welding mode, so that the connection strength of the central conductor can be ensured. The central conductor can be a solid rod or a hollow pipe, and the central conductor can play a role in supporting, fixing and externally connecting, so that the central conductor is not limited. And the central conductor protrudes outwards a certain distance from the outer surface of the high-voltage insulating layer 1330, so that a longer dry arc distance can be provided through the arrangement of the external insulating layer 1340, and the lightning protection capability of the dry-type transformer 10 is effectively improved.

The external insulation layer 1340 is made of high-temperature vulcanized silicone rubber, and advantages of the high-temperature vulcanized silicone rubber are as described above, and are not described again.

The external insulating layer 1340 and the high-voltage insulating layer 1330 are integrally injection molded, so that the interface caused by different materials between the high-voltage insulating layer 1330 and the external insulating layer 1340 is avoided, the problems of no water vapor permeation and the like are solved, the sealing performance is better, the time for independently preparing the external insulating layer 1340 is saved in the integral molding process, the processing period is short, the labor cost and the manufacturing energy consumption are reduced, and the overall cost is lower.

Before the high-temperature vulcanized silicone rubber is integrally injected, six taps are connected on each high-voltage coil 1320 through arranging the tool connecting piece 101, so that the situation that the six taps are also coated by the silicone rubber in the injection process and cannot be used for wiring is avoided. Referring to fig. 14, the tool connecting piece 101 is an aluminum alloy plate, a protection cavity is arranged on the plate surface of the tool connecting piece 101, the protection cavity is six same step holes 1011, and threads are further arranged on the inner wall of the step holes 1011. Six step holes 1011 are arranged in two rows in parallel, and three step holes 1011 are arranged in each row so that the first tap changer and the second tap changer are also arranged in parallel. Meanwhile, before integral injection, after six taps are respectively connected to the six step holes 1011, 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 silicon rubber is prevented from filling the six step holes 1011, and the situation that the six taps cannot be used for wiring after being coated by the silicon rubber is avoided.

While the present disclosure and features have been described above with respect to specific embodiments, it will be appreciated that those skilled in the art, upon attaining the teachings of the present disclosure, may readily devise numerous variations and modifications of the above-described structures and materials, including combinations of features that are individually disclosed or claimed herein, and obviously other combinations of such features. Such variations and/or combinations fall within the technical field to which the utility model relates and fall within the scope of the claims of the utility model.

Claims (10)

1. The utility model provides a high-voltage winding, its characterized in that, high-voltage winding includes coiling body, high-voltage coil, high-voltage insulating layer, external insulating layer, and the wire coiling is in form on the coiling body high-voltage coil, the both ends of wire form two external, the high-voltage insulating layer parcel high-voltage coil with the coiling body, external insulating layer parcel external lateral wall, external insulating layer with the integrative injection molding of high-voltage insulating layer.

2. The high voltage winding of claim 1, wherein the external connection further has a center conductor connected thereto, the center conductor for supporting the external connection, the external connection insulating layer encasing the external connection and the center conductor.

3. The high voltage winding of claim 2, wherein the external connection is connected to the center conductor by welding.

4. The high voltage winding of claim 1, wherein the outer insulation layer comprises a sheath and a plurality of sheds, the sheath is disposed at the outer periphery of the outer connection, and the plurality of sheds are disposed at intervals at the outer periphery of the sheath.

5. The high-voltage winding according to claim 1, wherein the winding body comprises a plurality of winding plates, the wire is wound on the winding plates to form the high-voltage coil, a plurality of comb teeth are arranged on the winding plates, and the plurality of winding plates are uniformly distributed along the circumferential direction of the high-voltage winding.

6. The high voltage winding of claim 5, wherein said high voltage coil comprises a plurality of coils, at least one of said coils being disposed between two adjacent ones of said comb teeth on said winding plate.

7. The high voltage winding of claim 5, wherein the winding body further comprises a plurality of auxiliary members, the plurality of auxiliary members are annular and are arranged at intervals along the axial direction of the high voltage winding, and the auxiliary members are connected with the winding board in a clamping manner.

8. The high voltage winding of claim 1, wherein the external insulation layer and the high voltage insulation layer are both made of high temperature vulcanized silicone rubber.

9. The high-voltage winding according to claim 1, wherein the high-voltage insulating layer fills a gap between the high-voltage coil and the winding body and both ends of the winding body.

10. A dry-type transformer comprising an iron core, a low-voltage winding and a high-voltage winding according to any one of claims 1-9, wherein the low-voltage winding is sleeved outside the iron core, and the high-voltage winding is sleeved outside the low-voltage winding.