Winding structure, winding method and epoxy resin vacuum pouring electronic current transformer

Abstract

The invention discloses a winding structure, a winding method and an epoxy resin vacuum pouring electronic current transformer. The structure comprises an iron core and a primary winding. The primary winding consists of a first copper ring layer, a second copper ring layer and a third copper ring layer which are spirally wound on the periphery of the iron core in sequence; a first insulation paper layer is covered between the first copper ring layer and the second copper ring layer, and a second insulation paper layer is covered between the second copper ring layer and the third copper ring layer. The number of surrounding turns of the second copper ring layer is smaller than that of the first copper ring layer, and an installation space is reserved on the outer surface of the first copper ring layer. The limiting separators are arranged in the installation space, detachably connected with one end of the second copper ring layer and distributed on the outer surface of the first copper ring layer in the circumferential direction at intervals, and first permeation gaps are formed between the limiting separators and the outer surface of the first copper ring layer. The third copper ring layer and the second copper ring layer are distributed in a staggered manner, and the sum of surrounding turns is smaller than that of the first copper ring layer. Compared with the prior art, the insulation performance and the mechanical stability of the primary winding can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of mutual inductors, and in particular to a winding structure, a winding method and an epoxy resin vacuum casting electronic current mutual inductor. Background Art

[0002] The mutual inductor has become an indispensable device in the manufacture of distribution switch control equipment such as existing power distribution systems and facilities. In the existing mutual inductor technology, in order to meet the requirements of high insulation performance and good partial discharge control, epoxy resin is generally used as the insulating material, and a fully enclosed structure is used to protect the internal core and winding. In order to achieve the design goals of high voltage, low excitation current and low loss, the winding structure in the prior art often uses multiple layers of copper wire to form the primary winding, and an insulating paper layer is arranged between each layer, and a semiconductor corrugated paper shielding layer is coated on the outside of the winding to improve the electric field distribution and partial discharge characteristics.

[0003] After research, the inventors found that because the multiple layers of copper wires are sequentially sheathed, the gaps between the copper wires of adjacent layers are too narrow, resulting in the inability of subsequent insulating resin to completely penetrate between the multiple layers of copper wires. After the adjacent layers of copper wires are missing the infiltration of insulating resin, the insulating paper layer of the transformer will withstand a greater voltage, and the interlayer electric field concentration phenomenon will increase, ultimately resulting in reduced insulation effect and operational stability of the transformer. Summary of the invention

[0004] The invention discloses a winding structure, a winding method and an epoxy resin vacuum casting electronic current mutual inductor to solve the technical problems existing in the related art.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions: In the first aspect, the present application provides a winding structure, which is applied to an epoxy resin vacuum cast electronic current transformer, characterized in that the winding structure includes an iron core and also includes: a primary winding, which includes a first copper coil layer and a second copper coil layer, the first copper coil layer is spirally wound around the outer periphery of the iron core in sequence, the second copper coil layer is spirally wound around the outer periphery of the first copper coil layer in sequence, a first insulating paper layer is covered between the first copper coil layer and the second copper coil layer, the number of turns of the second copper coil layer is less than the number of turns of the first copper coil layer, so as to reserve an installation space on one side of the second copper coil layer and on the outer surface of the first copper coil layer; a limiting separator, which is arranged at the installation space and is detachably connected to one end of the second copper coil layer, and the limiting separator is circumferentially spaced on the outer surface of the first copper coil layer. Multiple groups, and a first permeable gap is formed between the limiting separator and the outer surface of the first copper ring layer; wherein the primary winding also includes a third copper ring layer, the third copper ring layer is spirally wound on the outer surfaces of the multiple groups of limiting separators in sequence, and a second insulating paper layer is also covered between the third copper ring layer and the limiting separator, and the second insulating paper layer circumferentially covers the limiting separator and the second copper ring layer; the third copper ring layer and the second copper ring layer are staggered on the periphery of the first copper ring layer, and the sum of the number of windings of the third copper ring layer and the number of windings of the second copper ring layer is less than the number of windings of the first copper ring layer; a first pouring hole is opened on the surface of the second insulating paper layer and at a position between the third copper ring layer and the second copper ring layer, so as to pour resin into the first permeable gap through the first pouring hole.

[0006] In a second aspect, the present application provides a winding method for a winding structure, which is used to manufacture the winding structure described in the above scheme, comprising the following steps: Firstly, the first copper coil layer is spirally wound around the outer periphery of the iron core in sequence, so that the outer periphery of the iron core is completely covered by the first copper coil layer, and the first insulating paper layer is attached after the winding is completed; An initial point is randomly selected on the surface of the first insulating paper layer to wind the second copper coil layer. When winding to the last copper coil segment of the second copper coil layer, the connecting portion is pre-clamped on the last copper coil segment of the second copper coil layer, and then the last copper coil segment of the second copper coil layer and the connecting portion are attached to the surface of the first insulating paper layer. Adjust the positions of the overlapping portion and the supporting portion so that the supporting portion is stably attached to the surface of the first insulating paper layer; Winding a third copper coil layer on the surface of the overlapped portion until the third copper coil layer is completely wound; A third insulating paper layer is covered on the outer surface of the third copper ring layer; Resin is poured into the second infiltration gap through the second pouring hole, and the resin flows from the second infiltration gap into the first infiltration gap through the first pouring hole, and the pouring is stopped after the second infiltration gap and the first infiltration gap are both filled with resin.

[0007] In a third aspect, the present application provides an epoxy resin vacuum cast electronic current transformer, comprising an insulating shell, a base, a secondary winding and a winding structure described in any of the above schemes, wherein the winding structure is arranged in the insulating shell, the secondary winding is arranged on the primary winding in the winding structure, and the base is installed at the bottom of the insulating shell.

[0008] The technical solution adopted by the present invention can achieve the following beneficial effects: 1. The first copper coil layer is used as a reference layer to provide a stable winding foundation. The second copper coil layer on its periphery has a small number of windings, so an installation space is reserved on one side. By arranging a limit separator in this space, multiple first penetration gaps are formed with the outer surface of the first copper coil layer, providing necessary storage space for the subsequent uniform infusion of resin. The third copper coil layer is spirally wound on the outer surface of the limit separator and is staggered with the second copper coil layer on the periphery of the first copper coil layer. This design prevents the second insulating paper layer between the second and third copper coil layers from being in a position to withstand the maximum voltage at the same time, which is beneficial to reducing the local electric field concentration phenomenon caused by uneven infiltration of insulating resin. In addition, the second insulating paper layer covers the limit separator and the second copper coil layer to form a continuous insulating medium. When epoxy resin is poured into the first penetration gap through the first pouring hole, the resin can fully infiltrate the entire gap along the preset channel, so that the copper coil layers are firmly fixed mechanically and have good integrity in terms of heat conduction and stress dispersion. This helps to alleviate local discharge or high field effect that may be caused by the narrow gap between the insulating paper layers. At the same time, the sum of the number of turns of the third and second copper coil layers is controlled to be less than the number of turns of the first copper coil layer, so that the voltage distribution of the winding structure is more uniform, the accumulated voltage difference between layers is dispersed and reduced, the insulation effect is improved, and the overall operation stability is enhanced; 2. The setting of the connecting part is beneficial to improve the contact state between the outer copper ring segment of the second copper ring layer and the adjacent copper ring segment to a certain extent, and avoid friction or interference between the connecting part and the contact part of another adjacent copper ring layer when the outer ring segment of the second copper ring layer is sleeved with the connecting part, thereby reducing the local stress concentration phenomenon, and at the same time, it is not easy to affect the thermal conductivity of the second copper ring layer itself. Furthermore, the arc-shaped slot structure utilizes the elastic characteristics of the first and second elastic sub-parts, and can adapt to certain dimensional deviations and mechanical vibrations during the assembly process, so that the outer ring segment at one end of the second copper ring layer provides positioning support for the arc-shaped slot, and then the connecting part can be stably clamped on the outer ring segment at one end of the second copper ring layer. It should be pointed out that the "first elastic sub-part" and "second elastic sub-part" here refer to components with a certain elastic deformation ability, and their design can alleviate the tightening stress caused by external factors during the assembly process to a certain extent, and the "arc-shaped slot" is a groove-shaped structure formed by the smooth transition of the two elastic sub-parts, and its size and shape design are both conducive to the state of adapting to the shape of the outer ring segment at one end of the second copper ring layer. 3. The support portion plays a fixing and guiding role through the connection between the first support sub-portion and the overlapping portion, while the second support sub-portion and the longer abutting surface formed by it provide a continuous and stable support area after contacting the first insulating paper layer. In fact, the second support sub-portion is abutted against the first copper ring layer, but there is a first insulating paper layer in the middle; this not only helps to evenly distribute local stress, but also can form a relatively stable overall structure during the resin curing process, which is beneficial to reduce the risk of compressive deformation of the insulating paper layer and local electric field unevenness caused by local stress concentration to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 This is a schematic diagram of an embodiment of the present application for showing a winding structure after a portion of the copper coil of the primary winding is hidden; Figure 2 It is a partial schematic diagram of an embodiment of the present application for illustrating the connection relationship between the primary winding and the iron core; Figure 3 yes Figure 2 A magnified view of part A in FIG. Figure 4 It is a schematic diagram of the structure of an epoxy resin vacuum cast electronic current transformer according to an embodiment of the present application.

[0011] In the figure: 1. Iron core; 2. Primary winding; 21. First copper ring layer; 22. Second copper ring layer; 23. Third copper ring layer; 3. First insulating paper layer; 4. Limiting separator; 41. Overlapping part; 411. Overlapping surface; 4111. Arc-shaped interlocking sub-surface; 412. Penetration surface; 42. Connecting part; 421. First elastic sub-part; 422. Second elastic sub-part; 423. Arc-shaped slot; 424. Reinforcement sub-part; 43. Supporting part; 431. First supporting sub-part; 432. Second supporting sub-part; 4321. Abutting surface; 5. First penetration gap; 6. Second insulating paper layer; 61. First pouring hole; 7. Third insulating paper layer; 71. Second pouring hole; 8. Second penetration gap; 9. Insulating shell; 10. Base; 11. Secondary winding. DETAILED DESCRIPTION

[0012] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0013] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0014] The following is combined with Figures 1 to 4 , a winding structure, a winding method and an epoxy resin vacuum casting electronic current transformer provided by the present application are described in detail through specific embodiments and their application scenarios.

[0015] First, combining Figure 1~Figure 3 A winding structure of the present application is applied to an epoxy resin vacuum cast electronic current transformer, and the winding structure includes an iron core 1, a primary winding 2 and a limit separator 4; wherein, the primary winding 2 includes a first copper coil layer 21 and a second copper coil layer 22, the first copper coil layer 21 is spirally wound on the outer periphery of the iron core 1 in sequence, and the second copper coil layer 22 is spirally wound on the outer periphery of the first copper coil layer 21 in sequence, and a first insulating paper layer 3 is covered between the first copper coil layer 21 and the second copper coil layer 22, and the number of windings of the second copper coil layer 22 is less than the number of windings of the first copper coil layer 21, so as to reserve an installation space on one side of the second copper coil layer 22 and on the outer surface of the first copper coil layer 21.

[0016] Exemplarily, the limiting spacer 4 is arranged in the installation space and is detachably connected to one end of the second copper ring layer 22, and multiple groups of limiting spacers 4 are distributed circumferentially on the outer surface of the first copper ring layer 21, and a first permeable gap 5 is formed between the limiting spacers 4 and the outer surface of the first copper ring layer 21.

[0017] Exemplarily, the primary winding 2 further includes a third copper ring layer 23, which is spirally wound on the outer surface of multiple groups of limiting separators 4 in sequence, and a second insulating paper layer 6 is also covered between the third copper ring layer 23 and the limiting separator 4, and the second insulating paper layer 6 circumferentially covers the limiting separator 4 and the second copper ring layer 22. Further, the cross-sectional shape of a single copper ring segment of the first copper ring layer 21, the second copper ring layer 22 and the third copper ring layer 23 is circular.

[0018] Exemplarily, the third copper ring layer 23 and the second copper ring layer 22 are staggered on the periphery of the first copper ring layer 21, and the sum of the number of turns of the third copper ring layer 23 and the number of turns of the second copper ring layer 22 is less than the number of turns of the first copper ring layer 21; further, a first pouring hole 61 is opened on the surface of the second insulating paper layer 6 and located between the third copper ring layer 23 and the second copper ring layer 22, so that resin can be poured into the first penetration gap 5 through the first pouring hole 61.

[0019] On this basis, the first copper coil layer 21 provides a larger winding base as a reference layer, and the second copper coil layer 22 arranged in sequence on its outer periphery has an installation space reserved on one side due to the smaller number of winding turns. The installation space forms a plurality of first penetration gaps 5 with the outer surface of the first copper coil layer 21 through the limiting partition 4, thereby providing a necessary storage cavity for the subsequent uniform infusion of resin.

[0020] At the same time, the third copper ring layer 23 is spirally wound on the outer surface of each group of limiting separators 4 in sequence, and is staggered with the second copper ring layer 22 on the periphery of the first copper ring layer 21, so that the second insulating paper layer 6 between the second copper ring layer 22 and the third copper ring layer 23 is not structurally in the position that bears the maximum voltage at the same time, which is beneficial to reduce the local electric field concentration phenomenon caused by uneven infiltration of insulating resin between the layers to a certain extent.

[0021] In addition, the second insulating paper layer 6 forms a continuous insulating medium when covering the limiting separator 4 and the second copper ring layer 22. When the first pouring hole 61 is used to inject epoxy resin into the first penetration gap 5, the resin can fully infiltrate the entire first penetration gap 5 along the preset channel, so that the first copper ring layer 21, the second copper ring layer 22 and the third copper ring layer 23 are not only firmly fixed mechanically, but also have good integrity in terms of heat conduction and stress dispersion. This design is beneficial to alleviate, to a certain extent, local discharge or local high field effect that may occur due to the narrow gap between the insulating paper layers.

[0022] Furthermore, by controlling the sum of the number of turns of the third copper coil layer 23 and the second copper coil layer 22 to be lower than the number of turns of the first copper coil layer 21, the entire winding structure presents a relatively uniform characteristic in voltage distribution, which helps to disperse and reduce the accumulated voltage difference between layers, improve the insulation effect and enhance the overall operating stability; at the same time, since the second copper coil layer 22 is staggered on the periphery of the third copper coil layer 23, and the sum of the number of turns of the third copper coil layer 23 and the number of turns of the second copper coil layer 22 is less than the number of turns of the first copper coil layer 21, a part of the gap will be reserved between the second copper coil layer 22 and the third copper coil layer 23, and the first casting hole 61 is opened here, so the epoxy resin can be smoothly cast into the first penetration gap 5 through the first casting hole 61.

[0023] It is worth noting that, although there is some ambiguity in the terminology regarding the setting of the limit separator 4 and the first penetration gap 5, the limit separator 4 referred to in this embodiment refers to a component that can be disassembled and connected to the second copper ring layer 22 when necessary and at the same time form a gap sufficient for resin penetration, while the first penetration gap 5 refers to a gap reserved between the limit separator 4 and the outer surface of the first copper ring layer 21 into which the resin can be fully impregnated. Its design is beneficial to reducing local stress concentration and voltage unevenness to a certain extent, thereby improving the insulation performance and long-term stability of the transformer during actual operation.

[0024] In general, through the coordinated effect of the above-mentioned structural elements, the present invention is beneficial to a certain extent in alleviating the problems of local electric field concentration and increased pressure on the insulating paper layer caused by insufficient resin impregnation in the multi-layer copper coil winding, while optimizing the electrical and mechanical properties of the winding, thereby improving the overall operating efficiency of the entire transformer.

[0025] In some embodiments, in combination Figure 1~Figure 3 The limiting separator 4 is made of insulating material, and includes a lap portion 41, a connecting portion 42 and a supporting portion 43; further, the insulating material can be made of glass fiber, mica tape or DMD insulating material.

[0026] Exemplarily, the overlapping portion 41 is arranged in the installation space, and the extension direction of the overlapping portion 41 is consistent with the extension direction of the outer peripheral contour line of the first copper ring layer 21; the connecting portion 42 is arranged at one end of the overlapping portion 41, for detachably connecting with the outer ring segment of one end of the second copper ring layer 22; the supporting portion 43 is arranged in multiple groups at intervals on the overlapping portion 41, and the supporting portion 43 is used to abut against the first insulating paper layer 3 on the surface of the first copper ring layer 21.

[0027] On this basis, the overlapping portion 41 is arranged in the installation space, and its extension direction is consistent with the outer peripheral contour line of the first copper coil layer 21. Such a design helps to form a relatively continuous and stable mounting surface, so that the third copper coil layer 23 can be smoothly overlapped on the overlapping portion 41; at the same time, the connecting portion 42 is arranged at one end of the overlapping portion 41 to achieve a detachable connection with the outer coil segment of one end of the second copper coil layer 22. This detachable design is beneficial to adjust or replace the relationship between the limiting partition 4 and the copper coil layer during subsequent assembly or maintenance, thereby having a positive impact on the overall performance of the winding structure; in addition, a plurality of supporting portions 43 are arranged at intervals on the overlapping portion 41, and their function is to abut against the first insulating paper layer 3 on the surface of the first copper coil layer 21, provide local mechanical support and maintain the uniform distribution of the insulating paper layer of the first copper coil layer 21, thereby forming a stable overall structure after the resin is cured, reducing structural deformation or uneven insulation that may be caused by local stress concentration.

[0028] It should be noted that the "lap part 41" here mainly refers to the component that is positioned relative to the first copper coil layer 21 to assist in forming the impregnation gap, and at the same time provides a stable installation foundation for the winding of the third copper coil layer 23; the "connection part 42" refers to the component used to achieve the detachable connection with the outer ring section of the second copper coil layer 22, and the "support part 43" refers to the part used to partially support and abut the first insulating paper layer 3 to maintain the stability of the overall structure. Through the synergistic effect of their respective structural characteristics, each component is beneficial to optimize the resin penetration effect to a certain extent, reduce the local voltage increase and local discharge risk caused by the lack of sufficient resin impregnation in the insulating paper layer, and thus improve the insulation performance and operation stability of the transformer as a whole.

[0029] Exemplarily, the overlapping portion 41 has an overlapping surface 411 and a permeable surface 412 facing each other, the overlapping surface 411 is used for the third copper ring layer 23 to surround, and part of the first permeable gap 5 is formed between the permeable surface 412 and the outer surface of the first copper ring layer 21.

[0030] In some embodiments, Figure 1~Figure 3As shown, the connecting portion 42 includes a first elastic sub-portion 421 and a second elastic sub-portion 422, wherein the first elastic sub-portion 421 and the second elastic sub-portion 422 both extend in an arc shape in a direction away from the overlapping portion 41, and the surfaces of the first elastic sub-portion 421 and the second elastic sub-portion 422 away from the overlapping portion 41 are smoothly transitioned to form an arc-shaped card slot 423 that is partially sleeved with the outer ring segment at one end of the second copper ring layer 22; the length of the arc-shaped card slot 423 is 3 / 4 of the cross-sectional circumference of the outer ring segment at one end of the second copper ring layer 22; when the arc-shaped card slot 423 and the outer ring segment at one end of the second copper ring layer 22 are in a sleeved state, the arc-shaped card slot 423 avoids the contact portion between the outer ring segment of the second copper ring layer 22 and another adjacent copper ring segment. Exemplarily, the first elastic sub-portion 421 and the second elastic sub-portion 422 can be made of some insulating rubber materials, such as silicone rubber, EPDM rubber, and polyurethane rubber.

[0031] After such arrangement, it is beneficial to improve the contact state between the outer copper ring segment of the second copper ring layer 22 and the adjacent copper ring segment to a certain extent, and avoid friction or interference between the contact part of the connecting part 42 and another adjacent copper ring layer when the outer ring segment of the second copper ring layer 22 is sleeved with the connecting part 42, thereby reducing the local stress concentration phenomenon, and at the same time, it is not easy to affect the thermal conductivity of the second copper ring layer 22. Furthermore, the arc-shaped slot 423 structure utilizes the elastic characteristics of the first and second elastic sub-parts 422, and can adapt to certain dimensional deviations and mechanical vibrations during the assembly process, so that the outer ring segment at one end of the second copper ring layer 22 provides positioning support for the arc-shaped slot 423, so that the connecting part 42 can be stably clamped on the outer ring segment at one end of the second copper ring layer 22. It should be pointed out that the "first elastic sub-portion 421" and the "second elastic sub-portion 422" here refer to components with a certain elastic deformation ability, and their design can alleviate the fastening stress caused by external factors during the assembly process to a certain extent, and the "arc-shaped groove 423" is a groove-like structure formed by a smooth transition between the two elastic sub-portions. The design of its size and shape is conducive to the state of adapting to the shape of the outer ring segment at one end of the second copper ring layer 22 to achieve a snap-fit ​​state.

[0032] Exemplarily, the connection portion 42 further includes a reinforcing sub-portion 424, on which the first elastic sub-portion 421 and the second elastic sub-portion 422 are both disposed, and the reinforcing sub-portion 424 is connected to one end of the lap portion 41; further, the minimum thickness of the reinforcing sub-portion 424 is greater than the thickness of the first elastic sub-portion 421, and the minimum thickness of the reinforcing sub-portion 424 is greater than the thickness of the second elastic sub-portion 422. After such arrangement, since the shape of the reinforcing sub-portion 424 itself is irregular, different places have different thicknesses, and the minimum thickness of the reinforcing sub-portion 424 is also greater than the thickness of the second elastic sub-portion 422 and the first elastic sub-portion 421, thereby making the reinforcing sub-portion 424 more stable than the second elastic sub-portion 422 and the first elastic sub-portion 421, and after being acted upon by external force, the reinforcing sub-portion 424 can also have better anti-deformation performance, thereby avoiding, to a certain extent, affecting the subsequent installation position of the lap portion 41 after the connection portion 42 is snapped into place.

[0033] In some embodiments, in combination Figure 1~Figure 3 , the cross-sectional outer diameters of the single copper ring segments of the first copper ring layer 21, the second copper ring layer 22, and the third copper ring layer 23 are all the same; illustratively, the position of the outer ring segment at one end of the second copper ring layer 22 on the lap joint surface 411 has an arc-shaped interlocking sub-surface 4111, the curvature of the arc-shaped interlocking sub-surface 4111 is adapted to the curvature of the cross-sectional outer periphery of the single copper ring segment of the third copper ring layer 23, and the arc-shaped interlocking sub-surface 4111 is the winding starting point of the third copper ring layer 23. illustratively, when the second insulating paper layer 6 is attached to the lap joint surface 411, the shape of the part of the second insulating paper layer 6 corresponding to the arc-shaped interlocking sub-surface 4111 is also adapted to the shape of the arc-shaped interlocking sub-surface 4111, so that the winding starting point of the third copper ring layer 23 is also the concave part of the second insulating paper layer 6 corresponding to the arc-shaped interlocking sub-surface 4111.

[0034] Exemplarily, along the outer contour line direction of the first copper ring layer 21, after the third copper ring layer 23 is spirally wound and formed starting from the arc-shaped mosaic sub-surface 4111, the distance between the starting copper ring segment of the third copper ring layer 23 and the outer ring segment at one end of the second copper ring layer 22 is greater than the cross-sectional outer diameter of a single copper ring segment of the first copper ring layer 21.

[0035] On this basis, when manually winding the third copper coil layer 23, there is no need to deliberately measure the winding starting point of the third copper coil layer 23, but the initial winding copper coil segment of the third copper coil layer 23 can be directly aligned with the arc-shaped interlocking sub-surface 4111 and placed, and the arc-shaped interlocking sub-surface 4111 is used as the winding starting point of the third copper coil layer 23 for winding. After such setting, the formed third copper coil layer 23 will directly form a certain distance with the second copper coil layer 22, and this distance is greater than the cross-sectional outer diameter of a single copper coil segment of the first copper coil layer 21. At the same time, this part is also the weak part of the entire first winding, so the first pouring hole 61 can be set here to facilitate the epoxy resin to be poured into the first penetration gap 5 through this place.

[0036] In some embodiments, in combination Figure 1~Figure 3 The support portion 43 includes a first support sub-portion 431 and a second support sub-portion 432 . The first support portion 43 is connected to the overlapping portion 41 , and the second support sub-portion 432 is disposed at one end of the first support portion 43 away from the overlapping portion 41 .

[0037] Exemplarily, the surface of the second supporting sub-portion 432 facing away from the first supporting portion 43 is configured as a contact surface 4321, and the length of the contact surface 4321 is greater than the sum of the cross-sectional outer diameters of the single copper ring segments of the two first copper ring layers 21, wherein after the contact surface 4321 contacts the surface of the first insulating paper layer 3, at least the single copper ring segments of the two first copper ring layers 21 are located within the projection range of the contact surface 4321.

[0038] After such arrangement, it can be beneficial to disperse and relieve the local mechanical stress of the primary winding 2 to a certain extent, and reduce the local deformation and displacement caused by external vibration, temperature fluctuation or mechanical impact. Specifically, the support portion 43 plays a fixing and guiding role through the connection between the first support sub-portion 431 and the overlap portion 41, while the second support sub-portion 432 and the longer abutment surface 4321 formed by it provide a continuous and stable support area after contacting the first insulating paper layer 3 (actually abutting with the first copper ring layer 21, but with a first insulating paper layer 3 in the middle), which not only helps to evenly distribute local stress, but also can form a relatively stable overall structure during the resin curing process, thereby helping to reduce the risk of compressive deformation of the insulating paper layer and local electric field unevenness caused by local stress concentration to a certain extent.

[0039] It should be pointed out that the "contact surface 4321" here refers to the surface on the second support part 43 used to contact the insulating paper layer and transmit mechanical support, and the "projection range" refers to the area covered in the vertical direction when the contact surface 4321 contacts the insulating paper layer. This design enables the pressure applied by the second support part 43 to the surface of the first copper coil layer 21 to be dispersed in the contact area, which is beneficial to improving the overall mechanical stability and electrical performance of the winding structure to a certain extent, and also helps to improve the heat conduction effect and reduce the possibility of local partial discharge.

[0040] In some embodiments, in combination Figure 1~Figure 3 The outer surface of the third copper ring layer 23 is covered with a third insulating paper layer 7 , and a second permeable gap 8 is formed between the third insulating paper layer 7 and the second copper ring layer 22 and on one side of the third copper ring layer 23 .

[0041] Exemplarily, the third insulating paper layer 7 is provided with a second pouring hole 71 , and when pouring the resin, the resin enters the second penetration gap 8 through the second pouring hole 71 , and then enters the first penetration gap 5 through the first pouring hole 61 .

[0042] After such arrangement, the third insulating paper layer 7 not only provides an additional physical barrier, but the second permeable gap 8 reserved between the third insulating paper layer 7 and the second copper ring layer 22 also provides an auxiliary channel for resin pouring, so that the resin can more fully fill the gaps between the layers of copper rings during the curing process, thereby improving heat conduction and dispersing stress. The "second permeable gap 8" here refers to the gap reserved between the third insulating paper layer 7 and the adjacent copper ring layer, and the "second pouring hole 71" is a special opening for the resin to preferentially enter the gap. The synergistic effect of the two is beneficial to the resin forming a continuous and uniform insulating medium between the layers, thereby helping to improve the safety and stability of the mutual inductor during long-term operation to a certain extent.

[0043] In a second aspect, the present application further provides a winding method for a winding structure, which is used to manufacture the winding structure in the above embodiment, comprising the following steps: First, the first copper coil layer 21 is spirally wound around the outer periphery of the iron core 1 in sequence, so that the outer periphery of the iron core 1 is completely covered by the first copper coil layer 21, and the first insulating paper layer 3 is attached after the winding is completed; An initial point is randomly selected on the surface of the first insulating paper layer 3 to wind the second copper ring layer 22. When the second copper ring layer 22 is wound to the last copper ring segment, the connecting portion 42 is pre-clamped on the last copper ring segment of the second copper ring layer 22, and then the last copper ring segment of the second copper ring layer 22 and the connecting portion 42 are attached to the surface of the first insulating paper layer 3. Adjust the positions of the overlap portion 41 and the support portion 43 so that the support portion 43 avoids the second copper ring layer 22 and is stably attached to the surface of the first insulating paper layer 3; The third copper coil layer 23 is wound on the surface of the overlap portion 41 until the winding of the third copper coil layer 23 is completed; A third insulating paper layer 7 is covered on the outer surface of the third copper ring layer 23; Resin is poured into the second infiltration gap 8 through the second pouring hole 71 , and the resin flows from the second infiltration gap 8 into the first infiltration gap 5 through the first pouring hole 61 , and pouring is stopped until both the second infiltration gap 8 and the first infiltration gap 5 are filled with resin.

[0044] It is worth noting that in the appendix of this application Figure 3 The dotted lines with arrows in the figure refer to the flow direction of the pouring of the epoxy resin, wherein one dotted line with an arrow flows into the second penetration gap 8 , and the other dotted line with an arrow flows into the first penetration gap 5 .

[0045] In a third aspect, the present application also provides an epoxy resin vacuum casting electronic current transformer, combined with Figure 4 , comprising an insulating housing 9, a base 10, a secondary winding 11 and a winding structure in any of the above embodiments, wherein: The winding structure is arranged in an insulating housing 9 , the secondary winding 11 is sleeved on the primary winding 2 in the winding structure, and the base 10 is installed at the bottom of the insulating housing 9 .

[0046] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0047] In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0048] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A winding structure, applied to epoxy resin vacuum casting electronic current transformer, characterized in that: The winding structure comprises an iron core (1), and further comprises: A primary winding (2), comprising a first copper coil layer (21) and a second copper coil layer (22), wherein the first copper coil layer (21) is spirally wound around the outer circumference of the iron core (1), and the second copper coil layer (22) is spirally wound around the outer circumference of the first copper coil layer (21), a first insulating paper layer (3) is provided between the first copper coil layer (21) and the second copper coil layer (22), and the number of windings of the second copper coil layer (22) is less than the number of windings of the first copper coil layer (21), so as to reserve an installation space on one side of the second copper coil layer (22) and on the outer surface of the first copper coil layer (21); A limiting separator (4) is arranged in the installation space and is detachably connected to one end of the second copper ring layer (22), wherein a plurality of groups of the limiting separators (4) are distributed at intervals in the circumferential direction on the outer surface of the first copper ring layer (21), and a first permeable gap (5) is formed between the limiting separators (4) and the outer surface of the first copper ring layer (21); wherein: The primary winding (2) further comprises a third copper ring layer (23), the third copper ring layer (23) being spirally wound on the outer surfaces of the plurality of groups of limiting separators (4) in sequence, and a second insulating paper layer (6) is also provided between the third copper ring layer (23) and the limiting separators (4), the second insulating paper layer (6) circumferentially covering the limiting separators (4) and the second copper ring layer (22); The third copper ring layer (23) and the second copper ring layer (22) are staggeredly distributed on the periphery of the first copper ring layer (21), and the sum of the number of turns of the third copper ring layer (23) and the number of turns of the second copper ring layer (22) is less than the number of turns of the first copper ring layer (21); A first pouring hole (61) is provided on the surface of the second insulating paper layer (6) and located between the third copper ring layer (23) and the second copper ring layer (22), so as to inject resin into the first permeable gap (5) through the first pouring hole (61).

2. The winding structure according to claim 1, characterized in that: The limiting separator (4) is made of insulating material, and comprises a lap joint portion (41), a connecting portion (42) and a supporting portion (43); wherein: The overlapping portion (41) is provided at the installation space, and an extending direction of the overlapping portion (41) is consistent with an extending direction of an outer peripheral contour line of the first copper ring layer (21); The connecting portion (42) is provided at one end of the overlapping portion (41) and is used for being detachably connected to an outer ring segment at one end of the second copper ring layer (22); A plurality of support portions (43) are arranged at intervals on the overlap portion (41), and the support portions (43) are used to abut against the first insulating paper layer (3) on the surface of the first copper ring layer (21).

3. The winding structure according to claim 2, characterized in that: The overlapping portion (41) comprises an overlapping surface (411) and a permeable surface (412) which are opposite to each other, the overlapping surface (411) being used for being surrounded by the third copper ring layer (23), and a portion of the first permeable gap (5) is formed between the permeable surface (412) and the outer surface of the first copper ring layer (21).

4. The winding structure according to claim 2, characterized in that: The connecting portion (42) comprises a first elastic sub-portion (421) and a second elastic sub-portion (422), wherein: The first elastic sub-portion (421) and the second elastic sub-portion (422) both extend in an arc shape in a direction away from the overlapping portion (41), and the surfaces of the first elastic sub-portion (421) and the second elastic sub-portion (422) away from the overlapping portion (41) are smoothly transitionally connected to form an arc-shaped groove (423) that is partially sleeved with an outer ring section at one end of the second copper ring layer (22); The length of the arc-shaped slot (423) is 3 / 4 of the circumference of the cross section of the outer ring segment at one end of the second copper ring layer (22); When the arc-shaped clamping groove (423) and an outer ring segment at one end of the second copper ring layer (22) are in a sleeved state, the arc-shaped clamping groove (423) avoids the contact portion between the outer ring segment of the second copper ring layer (22) and another adjacent copper ring segment.

5. The winding structure according to claim 4, characterized in that: The connecting portion (42) further comprises a reinforcing sub-portion (424), the first elastic sub-portion (421) and the second elastic sub-portion (422) are both arranged on the reinforcing sub-portion (424), and the reinforcing sub-portion (424) is connected to one end of the overlapping portion (41); The minimum thickness of the reinforcing sub-portion (424) is greater than the thickness of the first elastic sub-portion (421), and the minimum thickness of the reinforcing sub-portion (424) is greater than the thickness of the second elastic sub-portion (422).

6. The winding structure according to claim 3, characterized in that: The cross-sectional outer diameters of the individual copper ring segments of the first copper ring layer (21), the second copper ring layer (22) and the third copper ring layer (23) are all the same; The overlap surface (411) has an arc-shaped interlocking sub-surface (4111) at a position close to the outer ring segment at one end of the second copper ring layer (22), the arc of the arc-shaped interlocking sub-surface (4111) being adapted to the arc of the cross-sectional outer periphery of a single copper ring segment of the third copper ring layer (23), and the arc-shaped interlocking sub-surface (4111) being the winding starting point of the third copper ring layer (23), wherein: Along the direction of the outer peripheral contour line of the first copper ring layer (21), after the third copper ring layer (23) is spirally wound and formed in sequence starting from the arc-shaped interlocking sub-surface (4111), the distance between the starting copper ring segment of the third copper ring layer (23) and the outer ring segment at one end of the second copper ring layer (22) is greater than the cross-sectional outer diameter of a single copper ring segment of the first copper ring layer (21).

7. The winding structure according to claim 2, characterized in that: The support portion (43) comprises a first support sub-portion (431) and a second support sub-portion (432), the first support portion (43) being connected to the overlapping portion (41), and the second support sub-portion (432) being arranged at an end of the first support portion (43) away from the overlapping portion (41); The surface of the second supporting sub-portion (432) facing away from the first supporting portion (43) is configured as an abutment surface (4321), the length of the abutment surface (4321) being greater than the sum of the cross-sectional outer diameters of the single copper ring segments of the two first copper ring layers (21), wherein: After the abutment surface (4321) abuts against the surface of the first insulating paper layer (3), single copper ring segments of at least two of the first copper ring layers (21) are located within the projection range of the abutment surface (4321).

8. The winding structure according to any one of claims 2 to 7, characterized in that: The outer surface of the third copper ring layer (23) is covered with a third insulating paper layer (7), and a second permeable gap (8) is formed between the third insulating paper layer (7) and the second copper ring layer (22) and located on one side of the third copper ring layer (23); The third insulating paper layer (7) is provided with a second pouring hole (71). When pouring resin, the resin enters the second penetration gap (8) through the second pouring hole (71) and then enters the first penetration gap (5) through the first pouring hole (61).

9. A method for winding a winding structure, used for manufacturing the winding structure according to claim 8, characterized in that: The following steps are involved: First, the first copper coil layer (21) is spirally wound around the outer circumference of the iron core (1) in sequence, so that the outer circumference of the iron core (1) is completely covered by the first copper coil layer (21), and after the winding is completed, the first insulating paper layer (3) is attached; An initial point is randomly selected on the surface of the first insulating paper layer (3) to wind the second copper ring layer (22); when the second copper ring layer (22) is wound to the last copper ring segment, the connecting portion (42) is first pre-clamped onto the last copper ring segment of the second copper ring layer (22); and then the last copper ring segment of the second copper ring layer (22) and the connecting portion (42) are attached to the surface of the first insulating paper layer (3); Adjusting the positions of the overlapping portion (41) and the supporting portion (43) so that the supporting portion (43) avoids the second copper ring layer (22) and stably fits with the surface of the first insulating paper layer (3); Winding a third copper coil layer (23) on the surface of the overlapping portion (41) until the winding of the third copper coil layer (23) is completed; A third insulating paper layer (7) is covered on the outer surface of the third copper ring layer (23); Resin is poured into the second infiltration gap (8) through the second pouring hole (71), and the resin flows from the second infiltration gap (8) into the first infiltration gap (5) through the first pouring hole (61), and the pouring is stopped after the second infiltration gap (8) and the first infiltration gap (5) are both filled with resin.

10. An epoxy resin vacuum cast electronic current transformer, characterized in that: It comprises an insulating housing (9), a base (10), a secondary winding (11), and the winding structure according to any one of claims 1 to 8, wherein: The winding structure is arranged in an insulating housing (9), the secondary winding (11) is sleeved on the primary winding (2) in the winding structure, and the base (10) is installed at the bottom of the insulating housing (9).

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