Dry-type traction feedback transformer suitable for high altitude
By designing a compact winding structure and optimizing insulation materials in high-altitude environments, the short-circuit and electrical breakdown problems of the dry-type traction feedback transformer were solved, achieving stable operation and extending the life of the equipment.
Patent Information
- Application Number
- CN202422829944.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-20
AI Technical Summary
Dry-type traction feedback transformers are prone to short-circuit failures in high-altitude environments. The reasons include copper wire shrinkage, weak winding structure strength, increased insulation distance, and loose limiting structure, which lead to frequent short circuits and electrical breakdowns.
The low-voltage and high-voltage winding structures adopt a compact design, are wound with enameled copper rectangular wire and have enhanced interlayer insulation. Positioning components and inner support components are combined, cylindrical insulators and annular cooling air ducts are added, and they are fixed with clamp components. The insulation material is optimized to improve the mechanical strength and electrical insulation performance of the winding.
It effectively reduces inductance and capacitance losses, enhances magnetic flux, improves the structural strength and crack resistance of the winding, prevents short circuits and electrical breakdown, and improves the operating stability and life of the equipment.
Smart Images
Figure CN223378005U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of dry-type transformer manufacturing, in particular to a dry-type traction feedback transformer suitable for high altitudes. Background Art
[0002] Adhering to the goal of green development, the development of urban rail transit can effectively alleviate traffic congestion in large cities and reduce the incidence of safety accidents. Secondly, rail transit is powered by electricity, which reduces fuel pollutant emissions and improves urban air quality.
[0003] Dry-type traction regenerative transformers and dry-type traction rectifier transformers are both important devices that provide power in urban rail transit. These devices supply power to the multi-phase rectifier circuits that carry the traction load and are a special type of transformer. In the case of dry-type traction regenerative transformers, when power is applied, magnetic flux is generated in the primary winding. This flux is transferred through the iron core to the secondary winding, thereby forming an induced electromotive force in the secondary winding, allowing current to flow in the load. The regenerative transformer generates its own magnetic flux, hence the term "regenerative." With urban development, the construction of rail transit in high-altitude cities is also increasing.
[0004] Currently, dry-type traction regenerative transformers used in high-altitude rail transit are highly susceptible to short-circuit failures in practical applications. This is due to both external and internal factors. Externally, the frequent starting and braking of rail transit creates repeated shocks on the transformer, generating large inrush currents and electrodynamic forces within the transformer. Furthermore, rail transit requires a large amount of power, especially during peak hours, making it susceptible to overload. Internally, the following factors are present: 1) Low-voltage copper conductors are often made of copper foil. This structure, under the influence of large short-circuit inrush currents and electrodynamic forces, can cause the center of the winding to contract, resulting in inward deformation and leading to short-circuit failures. 2) Regenerative transformers typically utilize a double-split, four-winding structure. In high-altitude applications, the insulation distance between the main control track increases, and the spacer and retaining structure between the upper and lower windings are less robust. Furthermore, the structural strength of conventional high- and low-voltage windings is relatively weak, and cracking due to excitation forces is common, which can lead to short-circuit failures. Therefore, technical personnel urgently need to address these issues. Utility Model Content
[0005] Therefore, in view of the above-mentioned existing problems and defects, the designers of the present invention collected relevant information, conducted multiple evaluations and considerations, and, after continuous experimentation and modification by technicians with many years of R&D experience in this industry, ultimately led to the emergence of a dry-type traction feedback transformer suitable for high altitudes.
[0006] To address the above-mentioned technical problems, the present invention relates to a dry-type traction feedback transformer suitable for high-altitude operation, comprising a base, an iron core, a clamp assembly, a low-voltage winding, and a high-voltage winding. The iron core, mounted on the base, is composed of an iron core column and an iron yoke. The iron yoke is used to connect the iron core columns as a whole to form a closed magnetic circuit, and is structurally reinforced by the clamp assembly. The low-voltage winding is composed of an upper low-voltage coil and a lower low-voltage coil, which are mounted around the periphery of the iron core column and spaced a predetermined distance apart. The high-voltage winding is mounted around the periphery of the low-voltage winding and is composed of an upper high-voltage coil positioned opposite the upper low-voltage coil and a lower high-voltage coil positioned opposite the lower low-voltage coil. An annular cooling air duct is formed between the high-voltage winding and the low-voltage winding. The upper low-voltage coil and the lower low-voltage coil are both wound in layers using enameled rectangular copper wire. The dry-type traction feedback transformer suitable for high altitude operation also includes interlayer insulation. Interlayer insulation is the insulation material added between each layer of the upper and lower low-voltage coils. The insulation material is a composite of mesh cloth and alkali-free glass cloth.
[0007] As a further improvement to the technical solution disclosed in this utility model, a dry-type traction regenerative transformer suitable for high altitude operation also includes an upper cylindrical insulator and a lower cylindrical insulator. The upper cylindrical insulator is used to insulate the upper low-voltage coil from the upper high-voltage coil and is located within the annular cooling air duct. The lower cylindrical insulator is used to insulate the lower low-voltage coil from the lower high-voltage coil and is located within the annular cooling air duct.
[0008] As a further improvement of the technical solution disclosed in the present invention, the dry-type traction feedback transformer suitable for high altitudes also includes a positioning assembly. The positioning assembly includes an upper pad, a middle pad, and a lower pad. The upper pad is padded between the upper low-voltage coil, the upper high-voltage coil, and the clamp assembly. The middle pad is simultaneously padded between the upper low-voltage coil, the lower low-voltage coil, and between the upper high-voltage coil and the lower high-voltage coil. The lower pad is padded between the lower low-voltage coil, the lower high-voltage coil, and the base. The upper pad and the middle pad work together to position and fix the upper cylindrical insulator. The middle pad and the lower pad work together to position and fix the lower cylindrical insulator.
[0009] As a further improvement of the technical solution disclosed in the utility model, the positioning assembly further comprises rubber pads. The working surfaces of the upper pad, the middle pad and the lower pad are all padded with rubber pads.
[0010] Of course, as another modified design of the above technical solution, the upper pad, the middle pad and the lower pad are all subjected to plastic coating to form a plastic anti-collision layer on their respective outer side walls.
[0011] As a further improvement of the technical solution disclosed in the present invention, the clamp assembly is composed of a front clamping plate, a rear clamping plate and a bolt assembly. The front clamping plate and the rear clamping plate respectively press the front and rear side walls of the iron core in a one-to-one correspondence, and the two are connected and tightened by the bolt assembly.
[0012] As a further improvement of the technical solution disclosed in the present invention, the dry-type traction feedback transformer suitable for high altitudes further includes an internal support assembly. The internal support assembly is composed of an insulating internal support member inserted between the upper low-voltage coil, the lower low-voltage coil and the iron core column.
[0013] As a further improvement of the technical solution disclosed in the present utility model, the insulating inner support member is cut from epoxy glass cloth plates.
[0014] In practical applications, the dry-type traction feedback transformer for high altitudes disclosed in the present utility model can achieve at least the following beneficial technical effects, specifically:
[0015] 1) The design structure of the low-voltage winding and high-voltage winding is relatively compact, and the total length of the enameled copper rectangular wire required to wind and form the upper low-voltage coil, lower low-voltage coil, upper high-voltage coil, and lower high-voltage coil is significantly reduced, which means that the inductance and capacitance losses are also reduced, thereby benefiting the working performance and service life of the dry-type traction feedback transformer;
[0016] 2) Thanks to the selection of enameled copper flat wire and the unique winding method, the magnetic flux of the upper and lower low-voltage coils is significantly increased, which is conducive to the enhancement of their magnetic strength;
[0017] 3) Thanks to the unique design of interlayer insulation, on the one hand, the insulating material not only prevents short circuits between different layers, thus avoiding breakdown or leakage between coils due to excessive voltage, but also provides mechanical support and protection for each layer of enameled copper flat wire. On the other hand, the insulating material composed of mesh cloth and alkali-free glass fiber cloth has good absorptivity relative to epoxy resin, which facilitates the epoxy resin to penetrate through the insulating material and continue to penetrate into each wire turn, thereby effectively increasing the bonding area and bonding strength between each layer of enameled copper flat wire and epoxy resin. Whether it is the upper low-voltage coil or the lower low-voltage coil, the structural strength and crack resistance can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.
[0019] Figure 1 This is a partial structural diagram of a dry-type traction feedback transformer suitable for high altitudes disclosed in the utility model.
[0020] Figure 2 yes Figure 1 AA cross-sectional view.
[0021] Figure 3 The utility model discloses a front view of an upper low-voltage coil in a dry-type traction feedback transformer suitable for high altitudes.
[0022] Figure 4 The utility model discloses a top view of an upper low-voltage coil in a dry-type traction feedback transformer suitable for high altitudes.
[0023] Figure 5 This is a schematic diagram of the arrangement of the enameled copper flat wires in the upper low-voltage coil disclosed in the utility model.
[0024] Figure 6 The utility model discloses a schematic diagram of the weld layout of the enameled copper flat wire in the upper low-voltage coil from one perspective.
[0025] Figure 7 This is a schematic diagram of the weld layout of the enameled copper flat wire in the upper low-voltage coil disclosed in the utility model from another perspective.
[0026] Figure 8 It is a three-dimensional schematic diagram of a middle spacer in a dry-type traction feedback transformer suitable for high altitudes disclosed in the utility model.
[0027] Figure 9 It is a three-dimensional schematic diagram of a type of insulating inner support member in a dry-type traction feedback transformer suitable for high altitudes disclosed by the utility model.
[0028] Figure 10 It is a three-dimensional schematic diagram of another form of insulating inner support member in the dry-type traction feedback transformer suitable for high altitude disclosed by the utility model.
[0029] 1-base; 2-iron core; 21-iron core column; 22-iron yoke; 3-clamp assembly; 4-low-voltage winding; 41-upper low-voltage coil; 42-lower low-voltage coil; 5-high-voltage winding; 51-upper high-voltage coil; 52-lower high-voltage coil; 6-annular cooling air duct; 7-upper cylindrical insulator; 8-lower cylindrical insulator; 9-positioning assembly; 91-upper pad; 92-middle pad; 921-upper first embedded groove; 922-upper second embedded groove; 923-upper third embedded groove; 924-lower first embedded groove; 925-lower second embedded groove; 926-lower third embedded groove; 93-lower pad; 94-rubber pad; 10-inner support assembly; 101-insulating inner support. DETAILED DESCRIPTION
[0030] In the description of the present invention, it should be understood that the terms "left", "right", "front", "back", "up", "down", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.
[0031] The following is a further detailed description of the present invention in conjunction with specific embodiments. Figure 1The schematic diagram of the partial structure of the dry-type traction feedback transformer for high altitude disclosed by the present invention is shown. It can be seen that it is mainly composed of several parts such as a base 1, an iron core 2, a clamp assembly 3, a low-voltage winding 4, a high-voltage winding 5 and interlayer insulation (not shown in the figure). Among them, the iron core 2 uses the base 1 as the installation basis, and is composed of an iron core column 21 and an iron yoke 22. The iron yoke 22 is used to connect multiple iron core columns 21 placed side by side as a whole to form a closed magnetic circuit, and it is structurally reinforced by the clamp assembly 3. The clamp assembly 3 is composed of a front splint, a rear splint and a bolt assembly. The front splint and the rear splint are respectively pressed against the front and rear side walls of the iron core 2 in a one-to-one correspondence, and the two are connected and tightened by means of a bolt assembly. The low-voltage winding 4 is composed of an upper low-voltage coil 41 and a lower low-voltage coil 42 that are mounted on the periphery of the iron core column 21 and are spaced at a set distance. The high-voltage winding 5 is mounted on the periphery of the low-voltage winding 4 and is composed of an upper high-voltage coil 51 positioned opposite to the upper low-voltage coil 41 and a lower high-voltage coil 52 positioned opposite to the lower low-voltage coil 42. An annular cooling air duct 6 is formed between the low-voltage winding 4 and the high-voltage winding 5. The dry-type traction feedback transformer suitable for high altitudes is equipped with a fan unit to continuously supply cooling air to the annular cooling air duct 6, which greatly improves the output capacity of the dry-type traction feedback transformer. In this way, the design structure of the low-voltage winding 4 and the high-voltage winding 5 is extremely compact, and the total length of the wire required to wind and form the upper low-voltage coil 41, the lower low-voltage coil 42, the upper high-voltage coil 51, and the lower high-voltage coil 52 can be significantly reduced, which means that the inductance and capacitance losses are also reduced accordingly, thereby benefiting the working performance and service life of the dry-type traction feedback transformer.
[0032] It is particularly important to note that the upper high-voltage coil 51 and the lower high-voltage coil 52 continue to be wound in the traditional way, while the upper low-voltage coil 41 and the lower low-voltage coil 42 are both wound with enameled copper flat wire in layers, and the two adjacent welded joints are offset by more than 50 mm (such as Figure 3 、 4 , 5, 6, and 7). The interlayer insulation is a collection of insulating materials added between each layer of the upper low-voltage coil 41 and the lower low-voltage coil 42. The insulating material is a composite of mesh cloth and alkali-free glass cloth.
[0033] By adopting the above technical solution, on the one hand, thanks to the low resistance, high conductivity, high mechanical strength and other characteristics of the enameled copper flat wire, the upper low-voltage coil 41 and the lower low-voltage coil 42 formed have a smaller turn spacing, a more compact body, and a significant increase in magnetic flux, which is beneficial to the enhancement of their magnetic strength; on the other hand, thanks to the unique design of interlayer insulation, on the one hand, the insulating material can not only prevent the short circuit of current between different layers, but also avoid the short circuit of each coil (including the upper low-voltage coil 41, the lower low-voltage coil 42, the upper high-voltage coil 51 and the lower high-voltage coil 52) On the other hand, the insulating material composed of mesh cloth and alkali-free glass cloth has good absorption capacity relative to epoxy resin, which is beneficial for epoxy resin to penetrate through the insulating material and continue to penetrate and soak into each wire turn, thereby effectively improving the bonding area and bonding strength between each layer of enameled copper flat wire and epoxy resin, and the structural strength and crack resistance of both the upper low-voltage coil 41 and the lower low-voltage coil 42 can be greatly improved.
[0034] It is known that in actual operation, there is a large voltage difference between the low-voltage winding 4 and the high-voltage winding 5, which is very prone to dangerous situations such as electric shock, discharge and leakage. In serious cases, it may even cause the dry-type traction feedback transformer to fail. In view of this, as a further optimization of the above technical solution, Figure 1 、 2 As shown in FIG, an upper cylindrical insulator 7 and a lower cylindrical insulator 8 are provided in the annular cooling air duct 6. The upper cylindrical insulator 7 is used to insulate the upper low-voltage coil 41 from the upper high-voltage coil 51 and is built into the annular cooling air duct 6. The lower cylindrical insulator 8 is used to insulate the lower low-voltage coil 42 from the lower high-voltage coil 52 and is also built into the annular cooling air duct 6. The upper cylindrical insulator 7 and the lower cylindrical insulator 8 are made of insulating materials, such as insulating cardboard, insulating paper, and insulating rubber sheet.
[0035] It should also be noted that, thanks to the addition of the upper cylindrical insulator 7 and the lower cylindrical insulator 8, the interference of the electromagnetic field of the high-voltage winding 5 on the low-voltage winding 4 is effectively eliminated, ensuring the normal operation of the low-voltage winding 4. Furthermore, the addition of the upper cylindrical insulator 7 and the lower cylindrical insulator 8 effectively protects the upper low-voltage coil 41 and the lower low-voltage coil 42 from mechanical collisions or the influence of the external environment, which helps to reduce mechanical vibration and damage to the upper low-voltage coil 41 and the lower low-voltage coil 42. In addition, it also contributes to the stability of the dry-type traction feedback transformer design structure, allowing it to maintain a good shape for a long time, ensuring its normal operation and service life.
[0036] Depend on Figure 1 、 2It can also be clearly seen from the figure that the dry-type traction feedback transformer suitable for high altitudes also includes a positioning assembly 9. The positioning assembly 9 includes an upper pad 91, a middle pad 92 and a lower pad 93. The upper pad 91 is padded between the upper low-voltage coil 41 and the upper high-voltage coil 51 and the clamp assembly 3. The middle pad 92 is simultaneously padded between the upper low-voltage coil 41 and the lower low-voltage coil 42 and between the upper high-voltage coil 51 and the lower high-voltage coil 52. The lower pad 93 is padded between the lower low-voltage coil 42 and the lower high-voltage coil 52 and the base 1. The upper pad 91 and the middle pad 92 cooperate to position and fix the upper cylindrical insulator 7. The middle pad 92 and the lower pad 93 cooperate to position and fix the lower cylindrical insulator 8. As shown in FIG. Figure 8 As shown in , the center spacer 92 is formed with an upper first mounting groove 921, an upper second mounting groove 922, an upper third mounting groove 923, a lower first mounting groove 924, a lower second mounting groove 925, and a lower third mounting groove 926, which respectively limit the position of the upper low-voltage coil 41, the upper cylindrical insulator 7, the upper high-voltage coil 51, the lower low-voltage coil 42, the lower cylindrical insulator 8, and the lower high-voltage coil 52. This ensures stable support and fixation of the internal components of the dry-type traction feedback transformer, preventing excessive amplitude from being affected by excitation forces during actual operation. Furthermore, the dimensions of the annular cooling duct 6 are guaranteed, effectively reducing partial discharge during operation and ensuring the dry-type traction feedback transformer's suitability for high-altitude environments.
[0037] Furthermore, by Figure 1 As can be clearly seen in the diagram, the working surfaces of the upper pad 91, the middle pad 92, and the lower pad 93 are all lined with rubber pads 94. These pads are made of nitrile rubber or polyurethane rubber and are 3-5 mm thick. This effectively prevents resonance in the dry-type traction regenerative transformer during operation, thereby improving its operational reliability and stability and reducing operating noise and vibration.
[0038] Of course, as another modification design of the above technical solution, the rubber pad 94 can also be cancelled. The upper pad 91, the middle pad 92 and the lower pad 93 are all subjected to plastic coating to form a plastic anti-collision layer on their respective outer side walls.
[0039] like Figure 1 、 2As shown in , the dry-type traction feedback transformer suitable for high altitudes also includes an internal support assembly 10. The internal support assembly 10 is composed of a plurality of insulating internal supports 101 inserted between the upper low-voltage coil 41 and the lower low-voltage coil 42 and the core column 21. The insulating internal supports 101 are preferably cut from epoxy glass cloth sheets with excellent mechanical and dielectric properties and extremely high surface resistivity. According to the different pre-insertion positions, the shape of the internal support assembly 10 is also adaptively modified, such as Figure 9 、
[0040] 10. Thus, under the coordinated action of the inner support assembly 10 and the positioning assembly 9, the upper low-voltage coil 41, the lower low-voltage coil 42, the upper high-voltage coil 51, and the lower high-voltage coil 52 are ensured to occupy the correct assembly position relative to the dry-type traction feedback transformer, even after long-term operation and high excitation force conditions, thereby effectively avoiding the occurrence of electric shock, discharge, and leakage between the low-voltage winding 4 and the high-voltage winding 5 caused by changes in the size of the annular cooling air duct 6.
[0041] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A dry-type traction feedback transformer suitable for high altitudes, comprising a base, an iron core, a clamp assembly, a low-voltage winding and a high-voltage winding; the iron core uses the base as an installation foundation, and is composed of an iron core column and an iron yoke; the iron yoke is used to connect the iron core columns as a whole to form a closed magnetic circuit, and is structurally reinforced by the clamp assembly; the low-voltage winding is composed of an upper low-voltage coil and a lower low-voltage coil that are sleeved on the periphery of the iron core column and spaced a set distance apart; the high-voltage winding is sleeved on the periphery of the low-voltage winding, and is composed of an upper high-voltage coil positioned opposite to the upper low-voltage coil and a lower high-voltage coil positioned opposite to the lower low-voltage coil; an annular cooling air duct is formed between the high-voltage winding and the low-voltage winding, characterized in that, The upper low-voltage coil and the lower low-voltage coil are both wound in layers with enameled copper flat wire; the dry-type traction feedback transformer suitable for high altitudes also includes interlayer insulation; the interlayer insulation is a collection of insulating materials added between each layer of coils in the upper low-voltage coil and the lower low-voltage coil; the insulating material is a composite of mesh cloth and alkali-free glass fiber cloth.
2. The dry-type traction feedback transformer suitable for high altitude according to claim 1, characterized in that: It also includes an upper cylindrical insulator and a lower cylindrical insulator; the upper cylindrical insulator is used to insulate and isolate the upper low-voltage coil and the upper high-voltage coil, and is built into the annular cooling air duct; the lower cylindrical insulator is used to insulate and isolate the lower low-voltage coil and the lower high-voltage coil, and is built into the annular cooling air duct.
3. The dry-type traction feedback transformer suitable for high altitude according to claim 2, characterized in that: It also includes a positioning assembly; the positioning assembly includes an upper pad, a middle pad and a lower pad; the upper pad is padded between the upper low-voltage coil, the upper high-voltage coil and the clamp assembly; the middle pad is simultaneously padded between the upper low-voltage coil and the lower low-voltage coil and between the upper high-voltage coil and the lower high-voltage coil; the lower pad is padded between the lower low-voltage coil and the lower high-voltage coil and the base; the upper pad and the middle pad cooperate to position and fix the upper cylindrical insulator; the middle pad and the lower pad cooperate to position and fix the lower cylindrical insulator.
4. The dry-type traction feedback transformer suitable for high altitude according to claim 3, characterized in that: The positioning assembly also includes a rubber pad; the working surfaces of the upper pad, the middle pad and the lower pad are all padded with the rubber pad.
5. The dry-type traction feedback transformer suitable for high altitude according to claim 3, characterized in that: The upper pad, the middle pad and the lower pad are all subjected to a plastic coating process so as to form a plastic anti-collision layer on their respective outer side walls.
6. The dry-type traction feedback transformer suitable for high altitude according to claim 1, characterized in that: The clamp assembly consists of a front clamping plate, a rear clamping plate and a bolt assembly; the front clamping plate and the rear clamping plate respectively press the front and rear side walls of the iron core in a one-to-one correspondence, and the two are connected and tightened by means of the bolt assembly.
7. The dry-type traction feedback transformer suitable for high altitude according to any one of claims 1 to 6, characterized in that: It also includes an inner support assembly; the inner support assembly is composed of an insulating inner support member inserted between the upper low-voltage coil, the lower low-voltage coil and the iron core column.
8. The dry-type traction feedback transformer suitable for high altitude according to claim 7, characterized in that: The insulating inner support member is formed by cutting an epoxy glass cloth plate.