Dry-type transformer

Abstract

The application discloses a dry-type transformer, relates to the technical field of transformers, and comprises a transformer body and a cooling fan, wherein the transformer body comprises an iron core and a coil winding, the coil winding is wound on the iron core, a first heat dissipation gap is formed between the coil winding and the iron core, the first heat dissipation gap is greater than or equal to 8 mm, and the air outlet of the cooling fan is communicated with the first heat dissipation gap. The first heat dissipation gap with a width of more than 8 mm is constructed as a forced air duct, air resistance is greatly reduced, the heat generated between the coil winding and the iron core can be efficiently taken away by the cooling fan, the problem that heat is accumulated in the transformer body is solved, and the overall heat dissipation capacity of the dry-type transformer is improved. Even in a harsh environment in a high-altitude area where the natural convection heat dissipation efficiency is greatly reduced due to thin air, the dry-type transformer can still guarantee heat dissipation efficiency, so that the operation reliability and service life of the dry-type transformer in complex working conditions are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of transformer technology, and more specifically, to a dry-type transformer. Background Technology

[0002] Dry-type transformers in related technologies are mainly designed for low-altitude and mildly varying ambient temperatures. When applied to special environments with high altitudes, thin air, and severe thermal shocks, they are prone to overheating failures, leading to a significant decrease in operational reliability.

[0003] Therefore, how to improve the operational reliability of dry-type transformers in harsh environments has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a dry-type transformer to improve the operational reliability of dry-type transformers in harsh environments.

[0005] A dry-type transformer, comprising:

[0006] The transformer body includes an iron core and a coil winding. The coil winding is wound on the iron core, and there is a first heat dissipation gap between the coil winding and the iron core. The first heat dissipation gap is greater than or equal to 8mm.

[0007] A cooling fan, wherein the air outlet of the cooling fan is connected to the first heat dissipation gap.

[0008] In some embodiments, the outer wall of the coil winding is wrapped with a stress-reducing layer.

[0009] In some embodiments, the stress buffer layer includes a reinforcing substrate wrapped turn by turn around the outer wall of the coil winding, the reinforcing substrate including at least one of woven fabric, nonwoven fabric and porous film.

[0010] In some embodiments, the stress buffer layer further includes an insulating resin cured on the outer wall of the reinforcing substrate.

[0011] In some embodiments, the coil winding is wound with electromagnetic wire using an H-class insulation system.

[0012] In some embodiments, the coil winding includes:

[0013] An inner winding is wound on the iron core and has the first heat dissipation gap between it and the iron core.

[0014] An outer winding is sleeved outside the inner winding and a second heat dissipation gap exists between them. The air outlet of the cooling fan is connected to the second heat dissipation gap.

[0015] In some embodiments, the air volume of the cooling fan is greater than or equal to 4100 m³ / h;

[0016] And / or, the power of the cooling fan is greater than or equal to 150W.

[0017] In some embodiments, a dustproof screen is provided at the air inlet of the cooling fan, and filter cotton is provided at the dustproof screen.

[0018] In some embodiments, a guide plate is provided at the air outlet of the cooling fan, and the guide plate directs the airflow at the air outlet of the cooling fan to the first heat dissipation gap.

[0019] In some embodiments, the air guide plate and the dustproof net are either an integral structure or separate structures.

[0020] The dry-type transformer provided in this application includes a transformer body and a cooling fan. The transformer body includes an iron core and coil windings. The coil windings are wound on the iron core, and there is a first heat dissipation gap between the coil windings and the iron core. The first heat dissipation gap is greater than or equal to 8mm, thereby transforming the original narrow air layer between the coil windings and the iron core into a through-flow forced ventilation duct with a clear path. The air outlet of the cooling fan is connected to the first heat dissipation gap, so as to force the cooling airflow into the area between the iron core and the coil windings where heat easily accumulates.

[0021] Compared to related technologies, the dry-type transformer provided in this application utilizes a first heat dissipation gap exceeding 8mm in width as a forced airflow duct, significantly reducing air resistance. This allows the cooling fan to efficiently remove heat generated between the coil windings and the core, solving the problem of heat accumulation inside the transformer body and thus improving the overall heat dissipation capacity of the dry-type transformer. Therefore, even in high-altitude areas where thin air significantly reduces natural convection cooling efficiency, the dry-type transformer can still maintain heat dissipation efficiency, thereby significantly improving its operational reliability and service life under complex operating conditions. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a schematic diagram of the structure of the dry-type transformer disclosed in the embodiments of this application;

[0024] Figure 2 This is a schematic diagram of the stress buffer layer structure disclosed in the embodiments of this application;

[0025] Figure 3 This is a schematic diagram of the connection structure between the dustproof net and the air guide plate disclosed in the embodiments of this application.

[0026] Among them, 100 is the transformer body, 110 is the iron core, 111 is the first heat dissipation gap, 120 is the coil winding, 121 is the inner winding, 122 is the outer winding, 123 is the second heat dissipation gap, 130 is the stress buffer layer, 131 is the reinforcing substrate, and 132 is the insulating resin.

[0027] 200 is the cooling fan, 201 is the air inlet, 202 is the air outlet, 210 is the dust filter, 211 is the filter cotton, and 220 is the air guide plate. Detailed Implementation

[0028] The core of this application is to disclose a dry-type transformer to improve the operational reliability of dry-type transformers in harsh environments.

[0029] Hereinafter, embodiments will be described with reference to the accompanying drawings. Furthermore, the embodiments shown below do not limit the scope of the utility model as described in the claims. Additionally, the complete contents of the structures represented in the embodiments below are not limited to those necessary for the solution of the utility model as described in the claims. It should be noted that, for ease of description, only the parts relevant to the utility model are shown in the drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0030] Dry-type transformers in related technologies are mainly designed for conventional environments. When applied to harsh environments such as high altitudes where the air is thin and thermal shocks are severe, they face serious reliability problems due to reduced heat dissipation capacity and increased thermal stress. Specifically, their design has multiple defects: Structurally, the gap between the inner winding and the core is too small, usually only 3mm, which cannot form an effective forced ventilation channel, causing heat to accumulate inside the winding; in terms of the heat dissipation system, not only is the fan selection conservative (e.g., 125W power, 3300m³ / h air volume), which drastically reduces its heat dissipation capacity at high altitudes due to the reduced air density, but the air duct design is also unreasonable, with the airflow direction deviating from the high-temperature area, further worsening the heat dissipation conditions of the winding; in terms of temperature control strategy, the alarm threshold is set too low (e.g., 130℃), resulting in insufficient safety redundancy, easily triggering false shutdowns due to normal fluctuations, and failing to achieve proactive heat dissipation adjustment; in terms of material selection, the commonly used F-class insulating resin cannot withstand the severe thermal shock from -30℃ to full load, and is prone to cracking and causing insulation failure. In summary, the dry-type transformers in the related technologies are unsuitable for high-altitude applications in terms of structure, heat dissipation, temperature control, and materials, resulting in high overheating risk, poor operational stability, and unsatisfactory reliability. Therefore, this application discloses the following dry-type transformer.

[0031] Combination Figure 1 The dry-type transformer disclosed in this application includes a transformer body 100 and a cooling fan 200. The transformer body 100 includes an iron core 110 and a coil winding 120. The coil winding 120 is wound on the iron core 110, and a first heat dissipation gap 111 is provided between the coil winding 120 and the iron core 110. The first heat dissipation gap 111 is greater than or equal to 8mm, thereby transforming the original narrow air layer between the coil winding 120 and the iron core 110 into a through-flow forced ventilation duct with a clear path. The air outlet 202 of the cooling fan 200 is connected to the first heat dissipation gap 111, so as to force the cooling airflow into the area between the iron core 110 and the coil winding 120 where heat easily accumulates.

[0032] Compared to related technologies that rely solely on a 3mm gap for heat dissipation through heat conduction and weak natural convection, this application constructs a first heat dissipation gap 111 with a width exceeding 8mm as a forced airflow duct. This significantly reduces wind resistance, allowing the cooling fan 200 to efficiently remove the heat generated between the coil winding 120 and the iron core 110. This solves the problem of heat accumulation inside the transformer body 100, thereby improving the overall heat dissipation capacity of the dry-type transformer. Thus, even in high-altitude areas where the thin air significantly reduces the efficiency of natural convection heat dissipation, the dry-type transformer can still maintain its heat dissipation efficiency, thereby significantly improving the operational reliability and service life of the dry-type transformer under complex operating conditions.

[0033] Specifically, during the new product manufacturing stage, the size of the first heat dissipation gap 111 can be directly set to meet the heat dissipation requirements through mold and winding processes. For traditional dry-type transformers already in operation, radial expansion technology can be used. A specialized expansion tool is used to apply radial force to the coil winding 120, forming a first heat dissipation gap 111 that meets heat dissipation standards between it and the core 110. It should be noted that insulation debris and impurities generated during the expansion process need to be cleaned to reduce insulation hazards and ensure the safe and reliable operation of the dry-type transformer. The cooling fan 200 can be fixed using a bracket, and its installation position can be adjusted.

[0034] The 120mm coil winding is mainly composed of copper magnet wire and insulating materials such as epoxy resin. (Copper's coefficient of thermal expansion is approximately 17 × 10⁻⁶). -6 / K) is much higher than that of epoxy resin (approximately 30-60×10). -6 / K, even lower after curing). When a dry-type transformer rapidly switches from a low-temperature environment of -30°C to a full-load high-temperature environment (typically above 140°C), the copper conductor expands rapidly, while the cured epoxy resin matrix expands less and is brittle. This difference in deformation generates strong mechanical shear stress within the epoxy resin. When the stress exceeds the tensile strength of the epoxy resin, it will crack, leading to insulation failure. Therefore, in order to reduce cracking of the coil winding 120, in some embodiments disclosed in this application, combined with Figure 2 The outer wall of the coil winding 120 is wrapped with a stress buffer layer 130 with good insulation and mechanical strength. The stress buffer layer 130 is used to dissipate the mechanical stress caused by temperature changes, thereby improving the ability of the coil winding 120 to resist severe thermal shock, enabling the dry-type transformer to withstand thermal shock from -30℃ to full load high temperature, reducing the cracking rate of epoxy resin, and improving the operational reliability of the dry-type transformer.

[0035] For example, the stress buffer layer 130 may include a reinforcing substrate 131, which is wrapped turn by turn around the outer wall of the coil winding 120. The reinforcing substrate 131 may be selected from one or more of woven fabrics, nonwoven fabrics, and porous films. Among them, woven fabrics include glass fiber mesh, aramid fiber mesh, plain weave fabric, etc.; nonwoven fabrics include nonwoven fabrics, needle-punched felt, etc.; and porous films include foamed polyimide films, etc.

[0036] To achieve structural integration and optimize insulation performance, the stress buffer layer 130 may further include insulating resin 132 impregnated and cured on the outer wall of the reinforcing substrate 131. Specifically, taking the reinforcing substrate 131 as a mesh fabric as an example, before wrapping the electromagnetic wire of the coil winding 120, the mesh fabric can be pre-impregnated with insulating resin 132. After treatment, the insulating resin 132 will fill the fiber gaps of the mesh fabric and fuse with the epoxy resin matrix during the subsequent overall curing process of the coil winding 120, forming a composite stress buffer structure. This structure not only utilizes the elasticity of the mesh fabric to buffer stress, but also utilizes the cured insulating resin 132 to enhance adhesion and electrical insulation strength, significantly improving the electrical insulation performance of the dry-type transformer.

[0037] In other embodiments disclosed in this application, the coil winding 120 is wound with electromagnetic wire using an H-class insulation system. In other words, the coil winding 120 can be an H-class winding. The H-class insulation system, by employing materials with good heat resistance and mechanical stability such as aramid paper, polyimide film, or silicone rubber, fundamentally enhances the impact toughness of the coil winding 120's insulation material, effectively suppressing brittle cracking caused by severe temperature differences, thereby significantly improving the reliability and service life of the dry-type transformer. Furthermore, different H-class insulation materials can be used in combination; for example, a composite insulation structure of aramid paper and polyimide film can be used to balance electrical strength and mechanical toughness.

[0038] The coil winding 120 includes an inner winding 121 and an outer winding 122. The inner winding 121 is wound on the iron core 110, and a first heat dissipation gap 111 is provided between the inner winding 121 and the iron core 110. The outer winding 122 is sleeved on the inner winding 121, and a second heat dissipation gap 123 is provided between the outer winding 122 and the inner winding 121. The second heat dissipation gap 123 increases the overall heat dissipation area of ​​the coil winding 120. The air outlet 202 of the cooling fan 200 is connected to the second heat dissipation gap 123, thereby guiding the cooling airflow to the heat concentration area inside the coil winding 120, forming forced convection and improving heat dissipation efficiency. Specifically, the second heat dissipation gap 123 can be greater than or equal to 8mm to ensure heat dissipation efficiency. The inner winding 121 can be configured as a low-voltage winding, and correspondingly, the outer winding 122 can be configured as a high-voltage winding; alternatively, the inner winding 121 can be configured as a high-voltage winding, and correspondingly, the outer winding 122 can be configured as a low-voltage winding. This interchangeable configuration design allows the transformer to be optimized according to application requirements such as insulation requirements, heat dissipation paths, or outgoing line layouts, thereby improving the versatility and flexibility of the design.

[0039] To reduce the impact of low-density air conditions at high altitudes on the operating efficiency of the cooling fan 200, the cooling fan 200 can be selected with an air volume greater than or equal to 4100 m³ / h, or a power greater than or equal to 150 W, or both. This fundamentally solves the heat dissipation bottleneck problem under high-altitude conditions, keeps the temperature of the coil winding 120 within a safe threshold, effectively inhibits the thermal aging of the insulation material, prevents the dry-type transformer from being dated or triggering protective shutdown, and improves the environmental adaptability and operational reliability of the dry-type transformer under harsh conditions. Those skilled in the art will understand that when the first heat dissipation gap 111 is small, the heat exchange effect can be ensured by appropriately increasing the air volume of the cooling fan 200.

[0040] To address the issue of dust and impurities being drawn into the air duct and causing blockage during high-airflow operation of the cooling fan 200, combined with... Figure 1 This application adds a dustproof net 210 at the air inlet 201 of the cooling fan 200, and a filter cotton 211 is also installed at the dustproof net 210, thereby achieving double protection and effectively preventing pollutants from entering the interior of the cooling fan 200, thereby avoiding internal wear, insulation degradation and overload of the cooling fan 200 caused by dust accumulation.

[0041] It should be noted that the air outlet 202 can be located on the top or side of the cooling fan 200. Figure 1 The paper illustrates a technical solution where the air outlet 202 is located on the side of the cooling fan 200. When the air outlet 202 is located on the top of the cooling fan 200, the cooling fan 200 can be arranged at the bottom of the transformer body 100, with the air outlet 202 directly facing the first heat dissipation gap 111 and the second heat dissipation gap 123 to ensure heat dissipation efficiency. In some embodiments, to optimize the utilization efficiency of the cooling airflow, a guide plate 220 is provided at the air outlet 202 of the cooling fan 200. The guide plate 220 can shape and guide the originally diffused airflow, allowing it to accurately enter the first heat dissipation gap 111 and the second heat dissipation gap 123, achieving directional and precise air delivery and improving heat dissipation efficiency. Since the guide plate 220 is arranged close to the coil winding 120, it can be made of high-temperature resistant material. The specific structure of the guide plate 220 can be designed and adjusted according to the relative position and shape of the air outlet 202 and the first heat dissipation gap 111 and the second heat dissipation gap 123, and this application does not limit this.

[0042] Combination Figure 3The aforementioned air guide plate 220 and dustproof net 210 can be an integrated structure or a separate structure. An integrated structure formed by injection molding or stamping can simplify the assembly process and has a compact structure with high reliability. A separate structure has greater flexibility and can adjust the position of the air guide plate 220 according to different air duct positions to ensure that the cooling airflow can be accurately guided to the high-temperature area of ​​the coil winding 120 to ensure heat dissipation efficiency. Specifically, for a separate structure, the air guide plate 220 can be fixed to the dustproof net 210 by screwing, snapping or other means.

[0043] In some embodiments disclosed in this application, the dry-type transformer further includes a temperature control device that can detect the temperature of the coil winding 120. When the temperature of the coil winding 120 exceeds a first preset temperature, the temperature control device controls the cooling fan 200 to turn on; when the temperature of the coil winding 120 is lower than a second preset temperature, the temperature control device controls the cooling fan 200 to turn off, thereby ensuring that the dry-type transformer always operates within a safe temperature range. When the load increases or the ambient temperature rises, causing the temperature of the coil winding 120 to rise, the cooling fan 200 can intervene in time to prevent overheating, fully ensuring the reliability and safety of the dry-type transformer operation. Simultaneously, intelligent start-stop control can reduce the operating time and no-load energy consumption of the cooling fan 200. Specifically, the temperature control device may include a temperature probe for detecting the temperature of the coil winding 120 and a control module for setting a first preset temperature and a second preset temperature. The temperature probe can be directly embedded near the hot spot of the coil winding 120, and the control module allows the user to adjust the first preset temperature and the second preset temperature according to specific operating conditions.

[0044] For example, the temperature control device is configured with a first mode and a second mode. In the first mode, the first preset temperature is 80℃±1℃, and the second preset temperature is 60℃±1℃. In the second mode, the first preset temperature is 65℃±1℃, and the second preset temperature is 50℃±1℃. The first mode is suitable for typical indoor environments, mild climates, or relatively stable load conditions. The second mode is suitable for harsh conditions such as high altitudes, high temperatures, high humidity, or poor ventilation. By initiating forced air cooling earlier and stopping it later, it provides greater safety redundancy for the dry-type transformer and reduces accidental shutdowns.

[0045] In some embodiments, the dry-type transformer further includes an alarm and protection unit electrically connected to a temperature control device. When the temperature control device detects that the temperature of the coil winding 120 reaches an alarm threshold, the alarm and protection unit issues an alarm signal. When the temperature control device detects that the temperature of the coil winding 120 reaches a trip threshold, the alarm and protection unit performs a trip shutdown operation. The alarm threshold can be 145℃±1℃, and the trip threshold can be 155℃±1℃. The temperature control device enables proactive daily temperature management. When the temperature of the coil winding 120 continues to rise to the alarm threshold of 145℃, the alarm and protection unit issues a warning, reminding operators to intervene in maintenance promptly. If the temperature continues to rise to the trip threshold of 155℃, a shutdown protection operation is performed. This application effectively avoids false alarms caused by normal fluctuations by raising the alarm threshold from 130℃ to 145℃, and by constructing a 10℃ safety redundancy range between 145℃ and 155℃, it facilitates timely manual intervention and ensures the continuity of power supply.

[0046] The dry-type transformer disclosed in this application can improve heat dissipation efficiency by more than 20% through synergistic optimization of structure, ventilation, control and materials. This allows the temperature of the coil winding 120°C to be effectively controlled even in high-altitude environments of 3000 meters, ensuring the stable and reliable operation of the dry-type transformer under high-altitude conditions.

[0047] The terms "first" and "second," etc., used in the specification and claims of this application are used to distinguish different objects, not to describe a specific order, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units may include steps or units not listed, but rather steps or units not listed.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Specific technical means in some embodiments may be incorporated, in whole or in part, into another embodiment unless explicitly excluded by another embodiment. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dry-type transformer, characterized in that, include: The transformer body (100) includes an iron core (110) and a coil winding (120). The coil winding (120) is wound on the iron core (110), and there is a first heat dissipation gap (111) between the coil winding (120) and the iron core (110). The first heat dissipation gap (111) is greater than or equal to 8 mm. A cooling fan (200) has an air outlet (202) that is connected to the first heat dissipation gap (111).

2. The dry-type transformer as described in claim 1, characterized in that, The outer wall of the coil winding (120) is wrapped with a stress buffer layer (130).

3. The dry-type transformer as described in claim 2, characterized in that, The stress buffer layer (130) includes a reinforcing substrate (131) which is wrapped turn by turn around the outer wall of the coil winding (120). The reinforcing substrate (131) includes at least one of woven fabric, nonwoven fabric and porous film.

4. The dry-type transformer as described in claim 3, characterized in that, The stress buffer layer (130) further includes an insulating resin (132) cured on the outer wall of the reinforcing substrate (131).

5. The dry-type transformer as described in claim 1, characterized in that, The coil winding (120) is made of electromagnetic wire with H-class insulation system.

6. The dry-type transformer as described in claim 1, characterized in that, The coil winding (120) includes: Inner winding (121), the inner winding (121) is wound on the iron core (110) and there is a first heat dissipation gap (111) between the inner winding (121) and the iron core (110). The outer winding (122) is sleeved outside the inner winding (121) and there is a second heat dissipation gap (123) between the outer winding (122) and the inner winding (121). The air outlet (202) of the heat dissipation fan (200) is connected to the second heat dissipation gap (123).

7. The dry-type transformer as described in claim 1, characterized in that, The air volume of the cooling fan (200) is greater than or equal to 4100 m³ / h; And / or, the power of the cooling fan (200) is greater than or equal to 150W.

8. The dry-type transformer as described in claim 1, characterized in that, The air inlet (201) of the cooling fan (200) is provided with a dustproof net (210), and the dustproof net (210) is provided with filter cotton (211).

9. The dry-type transformer as described in claim 8, characterized in that, A guide plate (220) is provided at the air outlet (202) of the cooling fan (200), and the guide plate (220) directs the airflow at the air outlet (202) of the cooling fan (200) to the first heat dissipation gap (111).

10. The dry-type transformer as described in claim 9, characterized in that, The air guide plate (220) and the dustproof net (210) are either an integral structure or a separate structure.

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