High-voltage winding structure applied to large-capacity 35KV dry-type transformer
By optimizing the winding layer structure and using composite insulation materials, the problem of uneven voltage distribution between the high-voltage winding layers of the 35KV dry-type transformer was solved, resulting in improved insulation strength and electric field uniformity, reduced cost and size, and improved operating efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUXI ENOW ELECTRIC POWER EQUIP
- Filing Date
- 2025-05-12
- Publication Date
- 2026-05-26
AI Technical Summary
The existing 35KV dry-type transformer high-voltage winding structure has uneven interlayer voltage distribution under high voltage level conditions, which leads to increased use of insulation and conductive materials, increased manufacturing costs and increased load losses, larger winding size and increased operating costs.
It adopts a winding layer structure of at least 3 layers, with each layer of winding segments arranged into 2 or 4 segments, and set with spacer insulation segments and end insulation segments. Interlayer air channels are set between adjacent layers and connected by wires. The outermost winding layer has head wires, tail wires and tap wires. Composite insulation materials such as enameled wire, glass fiber and glass fiber cloth are used.
The voltage distribution between layers and segments was optimized, the electric field uniformity was improved, the insulation strength and heat dissipation performance were enhanced, the winding size and material consumption were reduced, and the production and operating costs were lowered.
Smart Images
Figure CN224287977U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power transformer technology, and in particular to a high-voltage winding structure for a large-capacity 35KV dry-type transformer. Background Technology
[0002] With the intelligent and intensive development of power systems, driven by the need to reduce the construction costs of power transmission and transformation projects and minimize land occupation, the demand for increasing the capacity of single transformers in power systems is becoming increasingly urgent. As the core electrical circuit for transformers to realize the input and output of electrical energy, the windings are usually made of copper / aluminum round or flat wires and equipped with various insulating components. Their performance directly determines the insulation strength, mechanical stability and heat resistance of the transformer.
[0003] Existing 35kV dry-type transformers generally employ an axially arranged winding structure with eight or more segments, and each segment typically has 11 or more layers. Under high-voltage conditions, this structure exhibits significant uneven voltage distribution between layers. To meet insulation design requirements, it is necessary to correspondingly increase the interlayer insulation thickness and air duct spacing. Furthermore, due to the specific limitations imposed by the dry-type transformer outgoing line process on the odd / even number of winding layers, the actual number of winding layers is usually designed to be an odd number, further increasing the overall radial dimension of the winding. These problems not only increase the amount of insulation and conductive materials used and raise manufacturing costs, but also significantly increase the overall life-cycle operating cost of the transformer due to the increased equivalent resistance of the windings leading to higher load losses. Summary of the Invention
[0004] The purpose of this invention is to provide a high-voltage winding structure for a large-capacity 35KV dry-type transformer, so as to solve the problems existing in the prior art.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0006] A high-voltage winding structure for a large-capacity 35KV dry-type transformer includes an inner winding insulation layer and an outer winding insulation layer. At least three winding layers are provided between the inner winding insulation layer and the outer winding insulation layer. The first winding layer has two winding segments, and the remaining winding layers have four winding segments. An insulating spacer is provided between adjacent winding segments in each winding layer, and end insulating segments are provided at both ends of each winding layer.
[0007] Interlayer air passages are provided between adjacent winding layers, and inner and outer insulation layers are respectively provided on both sides of the interlayer air passages along the layer direction; the multiple winding layers are connected by wires, and the head wire, tail wire, and tap wire are finally led out from the outermost winding layer.
[0008] In one possible implementation, the conductor includes an enameled wire, a multilayer glass fiber wrapped around the enameled wire, and a glass fiber cloth wrapped around the multilayer glass fiber.
[0009] In one possible implementation, the core wire of the enameled wire is made of copper or aluminum, and the outer periphery of the core wire is coated with one or more layers of insulating varnish.
[0010] In one possible implementation, the winding layer has four layers, with the first layer having two winding segments, the second layer having four winding segments, the third layer having four winding segments, and the fourth layer having four winding segments.
[0011] In one possible implementation, the number of turns in the first winding layer is 21% to 23% of the total number of turns.
[0012] In one possible implementation, the sum of the number of turns in the second and third winding layers is 39% to 41% of the total number of turns.
[0013] In one possible implementation, the number of turns in the fourth winding layer is 36% to 39% of the total number of turns.
[0014] The beneficial effects of the technical solution provided by this utility model include at least the following:
[0015] This technical solution includes an inner winding insulation layer and an outer winding insulation layer. At least three winding layers are arranged between the inner and outer winding insulation layers. The first winding layer has two winding segments, and the remaining winding layers have four winding segments. An insulating spacer is provided between adjacent winding segments within each winding layer, and end insulating segments are provided at both ends of each winding layer. Interlayer air passages are provided between adjacent winding layers, with an inner and outer insulation layer on both sides along the layer direction. The multiple winding layers are connected by wires, and the head, tail, and tap exit wires are finally led out from the outermost winding layer. In this configuration, by rationally arranging the number of winding layers and segments, the process requirements for tap exit and head / tail exit wires on the winding surface are met, achieving ideal interlayer and inter-segment working voltages, increasing the longitudinal capacitance distribution of the winding, improving the impulse voltage distribution, reducing the height of the high-voltage winding, and decreasing the overall winding size. In addition, the layers of the multi-layer winding are connected by wires, which makes the voltage difference between layers uniform and improves the electric field distribution. Interlayer air channels are set between adjacent winding layers, which not only meet the requirements of winding temperature rise, but also greatly improve the insulation strength between layers, reduce the radial dimension of the winding, reduce material consumption, and reduce production and operating costs. Attached Figure Description
[0016] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.
[0017] Figure 1 This illustration shows a schematic diagram of a high-voltage winding structure for a large-capacity 35KV dry-type transformer provided by an exemplary embodiment of the present invention.
[0018] In the diagram: 1. Inner insulation layer of the winding; 2. Outer insulation layer of the winding; 3. Winding layer; 4. Winding section; 5. Spacing insulation section; 6. End insulation section; 7. Interlayer air passage; 8. Inner insulation layer of the air passage; 9. Outer insulation layer of the air passage; 10. Conductor; 11. Head wire; 12. Tail wire; 13. Tap wire. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0020] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings of this utility model, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component, respectively. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more.
[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0022] Figure 1This illustration shows a schematic diagram of a high-voltage winding structure for a large-capacity 35kV dry-type transformer provided by an exemplary embodiment of the present invention. The high-voltage winding structure for a large-capacity 35kV dry-type transformer includes an inner winding insulation layer 1 and an outer winding insulation layer 2. At least three winding layers 3 are provided between the inner winding insulation layer 1 and the outer winding insulation layer 2. The first winding layer 3 has two winding segments 2, and the remaining winding layers 3 have four winding segments 2. An insulating interval 5 is provided between adjacent winding segments 2 in each winding layer 3, and an end insulating section 6 is provided at both ends of each winding layer 3. An interlayer air passage 7 is provided between adjacent winding layers 3, and an inner air passage insulation layer 8 and an outer air passage insulation layer 9 are respectively provided on both sides of the interlayer air passage 7 along the layer direction. The multiple winding layers 3 are connected by wires 10, and finally, a head wire 11, a tail wire 12, and a tap wire 13 are led out from the outermost winding layer 3.
[0023] It's worth noting that the winding is made up of many turns of wire wound according to a certain pattern. The head and tail leads refer to the leads at both ends of the winding; one end is called the head lead, and the other end is called the tail lead. The function of the head and tail leads is to connect to the external circuit, allowing current to flow into and out of the winding, thereby generating a magnetic field or inducing an electromotive force in the winding, realizing the mutual conversion of electrical energy and magnetic energy. Tap leads are taps led out from different positions on the winding. In some electrical equipment, to meet different voltage requirements or regulation performance, multiple tap points are set on the winding, and these are led out through tap leads.
[0024] In the embodiments of this application, the inner and outer insulation layers of the winding can ensure the insulation safety between the winding and the iron core and the outside. The design of at least three winding layers and segments can optimize the voltage distribution, reduce the voltage difference between layers, and improve the uniformity of the electric field. The spaced insulation section and the end insulation section prevent short circuits between winding segments and enhance the insulation performance. The interlayer air passage and the inner and outer insulation layers provide heat dissipation channels and strengthen the interlayer insulation to reduce the temperature rise. The multi-layer winding layer conductors are connected, and with the head and tail leads, the power input and output and electromagnetic conversion can be realized. The tap leads can adjust the voltage as needed to meet the requirements of different operating conditions, making the transformer operation more flexible and efficient.
[0025] In detail, conductor 10 includes enameled wire, multiple layers of glass fibers wrapped around the enameled wire, and glass fiber cloth wrapped around the multiple layers of glass fibers. The core of the enameled wire is copper or aluminum, and the core is coated with one or more layers of insulating varnish.
[0026] In this embodiment, the conductor 10 adopts a composite structure of enameled wire, multilayer glass filaments, and glass fiber cloth, achieving multiple performance optimizations: the copper / aluminum core wire provides an efficient conductive path, the surface insulating varnish forms a primary insulation barrier, and its special formula enhances the adsorption and wetting ability of the resin, laying the foundation for the bonding of the composite insulation layer; the outer multilayer glass filaments, with their high dielectric strength and mechanical strength, uniformly disperse the interlayer electric field and suppress partial discharge, and the porous structure combined with epoxy resin forms an "insulation-reinforcement" system, which improves the withstand voltage capability by 30%-40% and enhances the short-circuit rigidity; after surface treatment, the outermost glass fiber cloth resists winding stress and avoids conductor deformation through its warp and weft structure, and works with the inner layer to form a "buffer-constraint" insulation layer, which, together with resin curing, extends the winding's corona resistance life by more than 2 times.
[0027] Next, with four winding layers, the working principle of a high-voltage winding structure applied to a large-capacity 35KV dry-type transformer in this utility model embodiment will be explained.
[0028] The first layer of winding starts from the beginning of the winding. A certain length of wire should be reserved at the beginning and end of each winding segment for subsequent connection. The first layer of winding has two winding segments. By reducing the distance between segments, the number of turns in each segment is increased as much as possible. The number of turns in the first layer of winding is 21% to 23% of the total number of turns.
[0029] The second and third winding layers have four winding segments each, and the sum of the number of turns in the second and third winding layers is 39% to 41% of the total number of turns.
[0030] The fourth winding layer has four winding segments, and the number of turns in the fourth winding layer 3 is 36% to 39% of the total number of turns.
[0031] Specifically, the starting end of the first winding segment of the first winding layer is connected to the ending end of the first winding segment of the second winding layer by a wire; the ending end of the first winding segment of the first winding layer is connected to the starting end of the second winding segment of the second winding layer by a wire; the starting end of the second winding segment of the first winding layer is connected to the ending end of the third winding segment of the second winding layer by a wire; and the ending end of the second winding segment of the first winding layer is connected to the starting end of the third winding segment of the second winding layer by a wire.
[0032] The starting end of the first winding segment of the second winding layer is connected to the ending end of the first winding segment of the third winding layer by a wire; the ending end of the second winding segment of the second winding layer is connected to the starting end of the second winding segment of the third winding layer by a wire; the starting end of the third winding segment of the second winding layer is connected to the ending end of the third winding segment of the third winding layer by a wire; and the ending end of the fourth winding segment of the second winding layer is connected to the starting end of the fourth winding segment of the third winding layer by a wire.
[0033] The starting end of the first winding segment of the third winding layer is connected to the ending end of the first winding segment of the fourth winding layer by a wire. The ending end of the second winding segment of the third winding layer is connected to the starting end of the second winding segment of the fourth winding layer by a wire. The starting end of the third winding segment of the third winding layer is connected to the ending end of the third winding segment of the fourth winding layer by a wire. The ending end of the fourth winding segment of the third winding layer is connected to the starting end of the fourth winding segment of the fourth winding layer by a wire.
[0034] By arranging the number of turns and connecting the ends as described above, the interlayer voltage difference is reduced, the electric field distribution inside the winding is made more uniform, the partial discharge of the transformer is improved, the service life is extended, the thickness of the interlayer insulation of the transformer is reduced, the winding size is reduced, material consumption is reduced, product costs are saved, and the economic benefits of the product are improved.
[0035] In the embodiments disclosed in this utility model, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this utility model according to the specific circumstances.
[0036] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A high-voltage winding structure for a large-capacity 35KV dry-type transformer, characterized in that, It includes an inner winding insulation layer (1) and an outer winding insulation layer (2). At least three winding layers (3) are provided between the inner winding insulation layer (1) and the outer winding insulation layer (2). The first winding layer (3) has two winding segments (2), and the remaining winding layers (3) have four winding segments (2). An insulating spacer (5) is provided between adjacent winding segments (2) in each winding layer (3). An end insulating segment (6) is provided at both ends of each winding layer (3). Among them, an interlayer air passage (7) is provided between adjacent winding layers (3), and an inner insulation layer (8) and an outer insulation layer (9) are respectively provided on both sides of the interlayer air passage (7) along the layer direction; the multi-layer winding layers (3) are connected by wires (10), and finally the head wire (11), tail wire (12) and tap wire (13) are led out from the outermost winding layer (3).
2. The high-voltage winding structure for a large-capacity 35KV dry-type transformer according to claim 1, characterized in that, The conductor (10) includes an enameled wire, a multilayer glass fiber wrapped around the enameled wire, and a glass fiber cloth wrapped around the multilayer glass fiber.
3. The high-voltage winding structure for a large-capacity 35kV dry-type transformer according to claim 2, characterized in that, The core wire of the enameled wire is made of copper or aluminum, and the outer periphery of the core wire is coated with one or more layers of insulating varnish.
4. The high-voltage winding structure for a large-capacity 35KV dry-type transformer according to claim 1, characterized in that, The winding layer (3) has 4 layers. The first winding layer (3) has 2 winding segments (2), the second winding layer (3) has 4 winding segments (2), the third winding layer (3) has 4 winding segments (2), and the fourth winding layer (3) has 4 winding segments (2).
5. The high-voltage winding structure for a large-capacity 35kV dry-type transformer according to claim 4, characterized in that, The number of turns in the first winding layer (3) is 21% to 23% of the total number of turns.
6. The high-voltage winding structure for a large-capacity 35KV dry-type transformer according to claim 4, characterized in that, The sum of the number of turns in the winding layers (3) of the second and third layers is 39% to 41% of the total number of turns.
7. The high-voltage winding structure for a large-capacity 35KV dry-type transformer according to claim 4, characterized in that, The number of turns in the fourth winding layer (3) is 36% to 39% of the total number of turns.