Composite cooling stay structure and cooling system for low-voltage winding of transformer

Abstract

The composite cooling supporting strip structure comprises an iron core, a high-voltage winding, a low-voltage winding and cooling supporting strip units, the low-voltage winding is arranged between the iron core and the high-voltage winding, an insulating cylinder is arranged between the low-voltage winding and the iron core, and the cooling supporting strip units are arranged on the periphery of the low-voltage winding. The cooling supporting strip unit comprises a supporting strip body, an outer side fin-shaped heat conduction fin and an inner side fin-shaped heat conduction fin, the supporting strip body is provided with a hollow cavity, and the hollow cavity is provided with a cooling oil way. According to the invention, the cooling circulating pump drives oil in the stay to circulate so as to efficiently take away heat generated by the low-voltage winding, and the opening and closing high-strength heat-resistant insulating oil baffle plate device and the oil path parts at the two ends can be conveniently taken down so as to efficiently cool by air supply; the problems that the low-voltage winding is too high in temperature and the insulating layer is easy to age are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer heat dissipation, and in particular relates to a transformer low-voltage winding composite cooling support bar structure and a cooling system. Background Art

[0002] Transformers, as key components in power systems, are responsible for converting voltage to meet varying power demands. Within transformers, low-voltage windings often face significant heat dissipation challenges due to their electrical characteristics and location. Effective heat dissipation design can effectively reduce the operating temperature of low-voltage windings, minimizing the risk of insulation aging and mechanical strength degradation due to overheating, thereby extending the transformer's service life. Effective heat dissipation lowers the winding's temperature coefficient of resistance, thereby reducing copper losses during power conversion and improving the transformer's overall efficiency. Proper heat dissipation design helps maintain safe operating temperatures for transformer components, minimizing failures caused by localized overheating and ensuring continuous and stable operation. For applications with limited installation space, such as urban substations, efficient heat dissipation solutions enable more compact designs while ensuring adequate cooling, conserving valuable space. In challenging environments such as high humidity, salt spray, or high temperatures, specially designed heat dissipation systems can help transformers overcome these adverse conditions and ensure proper operation. The demand for heat dissipation design has driven the development of new thermally conductive materials and technologies, such as nanotechnology-enhanced insulation materials or heat dissipation devices integrated with intelligent monitoring systems, which have advanced transformer technology. By reducing problems caused by overheating, repair frequency and maintenance costs are reduced, indirectly improving economic benefits. Efficient heat dissipation design reduces unnecessary energy waste, meets energy conservation and emission reduction requirements, and contributes to sustainable development goals.

[0003] In short, the heat dissipation design of the transformer low-voltage winding not only directly affects the safety, reliability and service life of the equipment, but also has an important impact on the stability and economy of the entire power system. In the transformer design process, it is crucial to fully consider and solve the heat dissipation problem. Therefore, it is urgent to propose a transformer low-voltage winding composite cooling support structure and cooling system. Summary of the Invention

[0004] Purpose of the Invention

[0005] The present invention provides a transformer low-voltage winding composite cooling strut structure and cooling system. To address the problems in the prior art where the internal temperature of the low-voltage winding of the intervertebral disc is difficult to reduce only by traditional strut cooling, and the local temperature is too high, the present invention makes full use of the high thermal conductivity of the heat dissipation aluminum sheet to quickly and efficiently transfer heat to the heat dissipation surface of the aluminum sheet, and then quickly reduces the oil circuit temperature through a fan or a cooling circulation oil circuit cooling circulation pump, so that the low-voltage winding is within a suitable operating temperature range, avoids aging of the insulation material, reduces maintenance costs, and extends the service life of the transformer.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A transformer low-voltage winding composite cooling support bar structure includes: an iron core, a high-voltage winding, a low-voltage winding and a cooling support bar unit.

[0008] The low-voltage winding is arranged between the iron core and the high-voltage winding, and an insulating cylinder is provided between the low-voltage winding and the iron core. The side of the low-voltage winding facing the high-voltage winding is isolated from the high-voltage winding by an interphase baffle, and a predetermined distance is left between the interphase baffle and the low-voltage winding and the high-voltage winding;

[0009] A cooling support unit is provided on the periphery of the low-voltage winding, and the cooling support unit includes: a support body, outer fin-shaped heat-conducting fins and inner fin-shaped heat-conducting fins, the outer fin-shaped heat-conducting fins are provided on the side of the support body facing the high-voltage winding; the inner fin-shaped heat-conducting fins are provided on the side of the support body facing the iron core; the support body has a hollow cavity, and the hollow cavity is provided with a cooling oil circuit.

[0010] As a further description of the above scheme, a plurality of cooling strut units are provided, and the cooling strut units are metal-resin composite structures, and the cooling strut units are evenly distributed circumferentially along the low-voltage winding; the cooling oil circuit is arranged in a serpentine shape in the hollow cavity of the strut body; the outer fin-shaped thermal conductive fins and the inner fin-shaped thermal conductive fins are made of aluminum alloy material; the strut body, the outer fin-shaped thermal conductive fins and the inner fin-shaped thermal conductive fins are integrally formed by modified epoxy resin through an in-mold injection molding process, and the modified epoxy resin is a high-strength heat-resistant insulating material.

[0011] As a further description of the above scheme, the above-mentioned transformer low-voltage winding composite cooling support structure also includes an oil circuit cooling circulation pump, and the inner surface of the channel of the serpentine cooling oil circuit is provided with turbulence enhancing ribs, the height of the turbulence enhancing ribs is 0.5-1mm, and the spacing between the turbulence enhancing ribs is 2-4mm; the cooling oil circuit is connected to the oil circuit cooling circulation pump through the end oil circuit oil blocks at both ends, and the end oil circuit oil blocks are connected to the oil circuit cooling circulation pump through quick-plug connectors.

[0012] As a further description of the above solution, it further includes end rings and end ring mounting assemblies, wherein the end rings include an upper end ring and a lower end ring, and the upper end ring and the lower end ring are respectively arranged at the top and bottom of the high-voltage winding through the end ring mounting assemblies;

[0013] The end oil passage block is fixedly connected to the cooling brace unit in the low-voltage winding by bolts; the cooling brace unit is an I-shaped structure, and the inner fin-shaped aluminum fin and the outer fin-shaped aluminum fin are connected to the two sides of the web of the cooling brace unit respectively;

[0014] The upper wing plate and the lower wing plate of the cooling brace unit extend axially along the low-voltage winding, and the width of the upper wing plate and the lower wing plate of the cooling brace unit is consistent with the width of the low-voltage winding.

[0015] As a further description of the above solution, the low voltage winding end is provided with a heat-resistant insulating oil baffle device, including an insulating oil baffle and a heat-resistant oil baffle transmission module that drives the opening and closing of the insulating oil baffle.

[0016] The heat-resistant oil baffle transmission module includes a motor, a transmission rod and a transmission gear block, one end of the transmission rod is fixed to the insulating oil baffle, and the other end of the transmission rod is engaged with the transmission gear block;

[0017] The transmission gear cooperates with the transmission gear block, and the edge of the insulating oil baffle is provided with a silicone sealing strip that cooperates with the end ring to form a sealed oil circuit.

[0018] As a further description of the above scheme, the surface of the outer fin-shaped thermal conductive fin is sprayed with a graphene thermal conductive coating; the inner fin-shaped thermal conductive fin is provided with a wavy guide groove; the outer fin-shaped thermal conductive fin and the inner fin-shaped thermal conductive fin are sealed by an end oil path oil baffle.

[0019] As a further description of the above solution, the support bar body, the outer fin-shaped heat-conducting fins and the inner fin-shaped heat-conducting fins are fixed to a dedicated mold, poured with epoxy resin and cooled to form an I-shaped insulating oil-blocking body.

[0020] As a further description of the above solution, the I-shaped insulating oil retaining structure has a built-in temperature sensor;

[0021] When the temperature exceeds a first preset threshold, the oil circuit cooling circulation pump is started;

[0022] When the temperature is lower than the second preset threshold, the oil circuit cooling circulation pump is shut down, and heat is naturally dissipated only through the cooling oil circuit, the outer fin-shaped heat conducting fins and the inner fin-shaped heat conducting fins.

[0023] As a further description of the above scheme, when the oil circuit cooling circulation pump is started, the oil cooling circuit is: oil circuit cooling circulation pump → end oil circuit oil block → oil circuit cooling pump exchange channel block → cooling oil circuit in the support body → main oil tank, forming a closed loop circulation.

[0024] A transformer cooling system includes the above-mentioned cooling brace structure and a temperature monitoring and speed regulation system, wherein the temperature monitoring and speed regulation system is electrically connected to the temperature sensor, the oil circuit cooling circulation pump, and the insulating oil baffle in the cooling brace structure, and the temperature monitoring and speed regulation system is configured as follows:

[0025] When the temperature sensor detects that the temperature of the low-voltage winding is lower than a second preset threshold, the oil circuit cooling circulation pump is shut down, and natural heat dissipation is performed only through the cooling oil circuit, the outer fin-shaped aluminum fins and the inner fin-shaped aluminum fins;

[0026] When the temperature of the low-voltage winding is higher than a first preset threshold, the oil circuit cooling circulation pump is controlled to operate so that the cooling oil circuit and the hollow cavity of the brace body form a full circulation cycle;

[0027] The temperature monitoring and speed regulation system is also configured with a turbulence compensation algorithm, which dynamically adjusts the speed of the oil circuit cooling circulation pump according to the real-time flow data of the cooling oil circuit.

[0028] Advantages and effects of the present invention:

[0029] 1. This invention fully utilizes the high thermal conductivity of aluminum, placing the large heat dissipation area of ​​the aluminum oil channel in full contact with the low-voltage winding. Heat generated by the low-voltage winding is transferred to the heat dissipation oil through the oil channel. Low-temperature cooling oil is continuously pumped into the low-voltage winding oil channel by an oil cooling circulation pump, while high-temperature cooling oil is pumped out of the cooling circulation pump, thereby effectively reducing the heat generated by the transformer's low-voltage winding. The proposed cooling structure can effectively reduce the heat generated by the low-voltage winding and reduce the subsequent maintenance costs of the transformer. It has significant application and economic significance for the analysis of the cooling system and heat dissipation of the transformer's low-voltage winding.

[0030] 2. This invention replaces the traditional resin stays for transformer low-voltage windings with composite stays featuring a metal-resin combination that allows for oil circulation. This flat design allows the metal sections on both sides to directly contact the foil winding, effectively transferring heat from the low-voltage winding to the oil circuit. The metal sections on both sides are separated by an I-shaped insulating oil barrier to achieve effective insulation. This stay features a rational design, precise assembly of components, and high mechanical strength, eliminating the risk of oil leakage or damage during use.

[0031] 3. The present invention connects each new type of support bar up and down in sequence, and finally leads to oil circulation holes respectively. Pipes are connected to the circulation holes and connected to the oil cooling circulation pump, thereby effectively reducing the temperature of the low-voltage winding.

[0032] 4. The novel heat dissipation support structure designed in the present invention can adopt oil cooling, and the oil cooling components can also be easily removed, leaving only the inner fin-shaped heat-conducting fins, the outer fin-shaped high-efficiency heat-conducting aluminum fins and the I-shaped insulating oil baffle to form an efficient air-cooled heat dissipation structure. The large area of ​​aluminum sheets can efficiently conduct the low-voltage winding temperature, so air cooling is used to achieve a good heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is an overall diagram of an embodiment of the present invention;

[0034] Figure 2 It is a local detail diagram within the overall diagram of an embodiment of the present invention;

[0035] Figure 3 This is a diagram of the iron core and fixing components according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic structural diagram of an upper clamp according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the lower clamping member structure according to an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of the core pull plate structure according to an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the structure of the coil upper pad according to an embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the structure of the coil lower pad according to an embodiment of the present invention;

[0041] Figure 9 This is a schematic diagram of the interphase baffle structure according to an embodiment of the present invention;

[0042] Figure 10 This is a schematic diagram of the end ring structure of an embodiment of the present invention;

[0043] Figure 11 This is a diagram of high and low voltage windings according to an embodiment of the present invention;

[0044] Figure 12 This is a schematic structural diagram of an insulating cylinder according to an embodiment of the present invention;

[0045] Figure 13 A high voltage winding diagram according to an embodiment of the present invention;

[0046] Figure 14 Schematic diagram of the dovetail brace structure according to an embodiment of the present invention;

[0047] Figure 15This is a schematic diagram of the dovetail pad structure according to an embodiment of the present invention;

[0048] Figure 16 Schematic diagram of the high-voltage winding coil structure of an embodiment of the present invention;

[0049] Figure 17 This is a low voltage winding diagram of an embodiment of the present invention;

[0050] Figure 18 This is a structural diagram of an oil cooling brace according to an embodiment of the present invention;

[0051] Figure 19 A partial detail diagram of the oil cooling brace structure according to an embodiment of the present invention;

[0052] Figure 20 A detailed diagram of the oil cooling brace structure according to an embodiment of the present invention;

[0053] Figure 21 This is a structural diagram of an air-cooled support bar according to an embodiment of the present invention;

[0054] Figure 22 This is a schematic diagram of the structure of the outer fin-shaped high-efficiency heat-conducting aluminum fin according to an embodiment of the present invention;

[0055] Figure 23 This is a schematic diagram of the structure of the inner fin-shaped heat conducting fin according to an embodiment of the present invention;

[0056] Figure 24 This is a schematic structural diagram of an I-shaped insulating oil retaining structure according to an embodiment of the present invention;

[0057] Figure 25 This is a schematic structural diagram of an end oil passage oil baffle according to an embodiment of the present invention;

[0058] Figure 26 This is a schematic structural diagram of an end oil passage oil block according to an embodiment of the present invention;

[0059] Figure 27 This is a schematic diagram of the oil circuit cooling pump exchange channel block structure according to an embodiment of the present invention;

[0060] Figure 28 This is a structural schematic diagram of an insulating oil baffle device according to an embodiment of the present invention;

[0061] Figure 29 Details of the insulating oil baffle device according to the embodiment of the present invention Figure 1 ;

[0062] Figure 30 Partial details of the insulating oil baffle device according to an embodiment of the present invention Figure 2 ;

[0063] Figure 31 Partial details of the insulating oil baffle device according to an embodiment of the present invention Figure 3 ;

[0064] Figure 32 This is a schematic diagram of the structure of an opening and closing fixing block according to an embodiment of the present invention;

[0065] Figure 33 This is a schematic structural diagram of a heat-resistant oil baffle transmission module according to an embodiment of the present invention;

[0066] Figure 34 Schematic diagram of the transmission rod structure according to an embodiment of the present invention;

[0067] Figure 35 This is a schematic diagram of the transmission gear block structure according to an embodiment of the present invention;

[0068] Figure 36 This is a schematic structural diagram of an insulating oil baffle according to an embodiment of the present invention;

[0069] Figure 37 Schematic diagram of the transmission gear structure according to an embodiment of the present invention;

[0070] Figure 38 Schematic diagram of the structure of the mating transmission block according to an embodiment of the present invention.

[0071] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0072] 1- iron core; 2- upper clamp; 3- high voltage winding; 4- upper pad of coil; 5- oil circuit cooling circulation pump; 6- end ring; 7- lower clamp; 8- low voltage winding; 9- lower pad of coil; 10- phase baffle; 11- iron core pull plate; 12- insulating cylinder; 13- dovetail support bar; 14- dovetail pad; 15- high voltage winding coil; 16- insulating oil baffle device; 17- oil circuit cooling pump exchange channel block; 18- end oil circuit oil passage block; 19- outer fin-shaped heat conducting fin; 20- I-shaped insulating oil baffle building; 21- end oil circuit oil baffle; 22- inner fin-shaped heat conducting fin; 23- opening and closing fixing block; 24- insulating oil baffle transmission module; 25- transmission rod; 26- transmission gear block; 27- insulating oil baffle; 28- transmission gear; 29- mating transmission block. DETAILED DESCRIPTION

[0073] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0074] like Figure 1-38The transformer low-voltage winding composite cooling support structure shown in the figure includes: an iron core 1, a high-voltage winding 3, a low-voltage winding 8 and a cooling support unit, wherein the low-voltage winding 8 is arranged between the iron core 1 and the high-voltage winding 3, and an insulating tube 12 is provided between the low-voltage winding 8 and the iron core 1. The side of the low-voltage winding 8 facing the high-voltage winding 3 is isolated from the high-voltage winding by an interphase baffle 10, and a predetermined distance is left between the interphase baffle 10 and the low-voltage winding 8 and the high-voltage winding 3. Specifically, the interphase baffle 10 is installed between the low-voltage winding 8 and the high-voltage winding 3, and the interphase baffle 10 is reserved by the upper clamp 2 and the lower clamp 7. The mounting holes are installed and fixed by insulating bolts. The setting of the phase baffle 10 plays an insulating isolation role to prevent phase short circuit and guide air flow to enhance heat dissipation efficiency. A cooling support unit is provided on the periphery of the low-voltage winding 8, wherein the cooling support unit includes: a support body, an outer fin-shaped heat-conducting fin 19 and an inner fin-shaped heat-conducting fin 22, wherein the outer fin-shaped heat-conducting fin 19 is provided on the side of the support body facing the high-voltage winding 3; wherein the inner fin-shaped heat-conducting fin 22 is provided on the side of the support body facing the iron core 1; wherein the support body has a hollow cavity, and the hollow cavity is provided with a cooling oil circuit.

[0075] The embodiment of the present invention is provided with a plurality of cooling support units, wherein the cooling support units are a metal-resin composite structure, and the cooling support units are evenly distributed circumferentially along the low-voltage winding 8; the cooling oil circuit is arranged in a serpentine shape in the hollow cavity of the support body; wherein the outer fin-shaped thermal conductive fins 19 and the inner fin-shaped thermal conductive fins 22 are made of aluminum alloy material; wherein the support body, the outer fin-shaped thermal conductive fins 19 and the inner fin-shaped thermal conductive fins 22 are integrally formed by modified epoxy resin through an in-mold injection molding process, and the modified epoxy resin is a high-strength heat-resistant insulating material. The present invention uses an in-mold injection molding process to achieve insulation isolation and fixation of the outer fin-shaped aluminum fin 19, the inner fin-shaped aluminum fin 22 and the support body; at the same time, the traditional resin support of the transformer low-voltage winding is designed as a composite support that is a metal-resin combination and can circulate oil. It adopts a flat design, and the metal parts on both sides are in direct contact with the foil winding, which can efficiently transfer the heat of the low-voltage winding 8 to the oil circuit. The metal on both sides is separated by an I-shaped insulating oil-blocking body 20 to achieve an insulation effect. The design of this support is reasonable, the various components are precisely combined, and the mechanical strength is high. There is no risk of oil leakage and easy damage during use; at the same time, the present invention fully utilizes the advantages of the high thermal conductivity of aluminum, and fully contacts the large heat dissipation area oil circuit channel made of aluminum with the low-voltage winding 8. The heat generated by the low-voltage winding 8 is transferred to the heat dissipation oil through the oil circuit channel. By continuously pumping low-temperature cooling oil into the cooling oil circuit and pumping out the high-temperature cooling oil circuit cooling circulation pump 5, the heat generated by the low-voltage winding 8 of the transformer is effectively reduced. The proposed cooling structure can effectively reduce the heat generated by the low-voltage winding 8 and reduce the subsequent maintenance cost of the transformer. It has important application and economic significance for the cooling system analysis and heat dissipation analysis of the low-voltage winding 8 of the transformer.

[0076] The transformer low-voltage winding composite cooling strut structure of the embodiment of the present invention also includes an oil circuit cooling circulation pump 5, wherein the inner surface of the channel of the serpentine cooling oil circuit is provided with turbulence enhancing ribs, wherein the turbulence enhancing ribs are 0.5-1mm high and the turbulence enhancing ribs are spaced 2-4mm apart; the cooling oil circuit is connected to the oil circuit cooling circulation pump 5 through the end oil circuit oil blocks 18 at both ends, wherein the end oil circuit oil blocks 18 are connected to the oil circuit cooling circulation pump 5 through quick-plug connectors. The present invention connects each new strut up and down in sequence, and finally leads to oil circuit circulation holes respectively, connects pipes to the circulation holes and connects to the oil circuit cooling circulation pump 5, thereby effectively reducing the temperature of the low-voltage winding 8.

[0077] The core pull plate 11 of the present invention is fixed on the core 1, and the upper clamp 2 and the lower clamp 7 have slots that match the core pull plate 11. The slots of the upper clamp 2 and the lower clamp 7 are aligned with the two ends of the core pull plate 11 to complete the installation, ensuring the stability of the core 1 structure.

[0078] The composite cooling support bar structure of the transformer low-voltage winding of an embodiment of the present invention also includes an end ring 6 and an end ring mounting assembly. The end ring 6 includes an upper end ring and a lower end ring, wherein the upper end ring and the lower end ring are both annular epoxy resin plates, and the upper end ring and the lower end ring are respectively arranged on the top and bottom of the high-voltage winding 3 through the end ring mounting assembly; specifically, the end ring mounting assembly includes mounting bolts, an upper coil pad 4 and a lower coil pad 9. When the upper end ring is installed, the mounting bolts are set on the upper clamp 2, and the upper end ring is pressed between the upper coil pad 4 and the top surface of the high-voltage winding 3 by the mounting bolts to ensure axial mechanical stability; the same applies to the lower end ring.

[0079] The upper and lower end oil passage blocks 18 are fixedly connected to the cooling brace unit in the low-voltage winding 8 by bolts; the cooling brace unit is an I-shaped structure, and the inner fin-shaped aluminum fin 22 and the outer fin-shaped aluminum fin 19 are connected to the two sides of the web of the cooling brace unit respectively;

[0080] The upper and lower wing plates of the cooling brace unit extend axially along the low-voltage winding 8, and the width of the upper and lower wing plates of the cooling brace unit is consistent with the width of the low-voltage winding 8.

[0081] The cooling brace unit is an I-shaped structure, and the two sides of the web of the cooling brace unit are connected to the inner fin-shaped aluminum fin 22 and the outer fin-shaped aluminum fin 19 respectively;

[0082] The upper wing plate and the lower wing plate of the cooling strut unit extend axially along the low-voltage winding 8 , and the width of the upper wing plate and the lower wing plate of the cooling strut unit is consistent with the width of the low-voltage winding 8 .

[0083] The end of the low-voltage winding 8 of the embodiment of the present invention is provided with a heat-resistant insulating oil baffle device 16, including an insulating oil baffle 27 and a heat-resistant oil baffle transmission module 16 that drives the opening and closing of the insulating oil baffle. The heat-resistant oil baffle transmission module 16 includes a motor, a transmission rod 25 and a transmission gear block 26, wherein one end of the transmission rod 25 is fixed to the insulating oil baffle 27, wherein the other end of the transmission rod 25 is engaged with the transmission gear block 26;

[0084] The transmission gear 28 cooperates with the transmission gear block 26, and a silicone sealing strip is provided on the edge of the insulating oil baffle 27 to cooperate with the end ring 6 to form a sealed oil circuit.

[0085] The outer fin-shaped heat-conducting fin 19 of the embodiment of the present invention is sprayed with a graphene thermal conductive coating; the inner fin-shaped heat-conducting fin 22 is provided with a wavy guide groove; the outer fin-shaped heat-conducting fin 19 and the inner fin-shaped heat-conducting fin 22 realize the closure of the oil circuit end through the end oil circuit oil baffle 21.

[0086] The support bar body, the outer fin-shaped heat conducting fins 19 and the inner fin-shaped heat conducting fins 22 of the embodiment of the present invention are fixed to a dedicated mold, poured with epoxy resin and cooled to form an I-shaped insulating oil blocking body 20.

[0087] The two upper clamps 2 and lower clamps 7 fixed on the iron core 1 have surfaces with fastening bolts parallel to the upper and lower circular surfaces of the winding respectively. After the end ring 6 on each side is placed in the specified position, the pad is installed between the end ring 6 and the clamps, and the bolts on the clamps are tightened to fix the end ring 6.

[0088] The dovetail pads 14 of the present invention are stacked in corresponding numbers or placed individually between every two high-voltage winding coils 15. There is a fixed slot at the tail of the dovetail pad 14. After the installation of each vertical row of dovetail pads 14 is completed, the dovetail support bar 13 is inserted into the fixed slot at the tail of each vertical row of dovetail pads 14 to complete the fixed installation.

[0089] The dovetail stays 13 of the present invention are arranged in a circular pattern, with a radius corresponding to the outer diameter of the insulating tube 12. The insulating tube 12 is installed inside the circular dovetail stays 13, thereby encircling the insulating tube 12 and achieving lateral stability. The top and bottom ends of the insulating tube 12 are flush with the end rings. After installing the upper coil spacer 4 and the lower coil spacer 9, they respectively secure the ends of the insulating tube 12, thus achieving longitudinal stability.

[0090] The I-shaped insulating oil retaining structure 12 of the embodiment of the present invention has a built-in temperature sensor;

[0091] When the temperature exceeds a first preset threshold, the oil circuit cooling circulation pump 5 is started. Preferably, the first preset threshold is 80°C;

[0092] When the temperature is lower than the second preset threshold, the oil circuit cooling circulation pump 5 is shut down, and the heat is naturally dissipated only through the cooling oil circuit, the outer fin-shaped heat conducting fins 19 and the inner fin-shaped heat conducting fins 22;

[0093] When the temperature is lower than the second preset threshold, the oil circuit cooling circulation pump 5 stops, and the heat is naturally dissipated only through the cooling oil circuit, the outer fin-shaped heat-conducting fins 19 and the inner fin-shaped heat-conducting fins 22. Preferably, the second preset threshold is 50°C. The new heat dissipation support structure designed by the present invention can be cooled by oil or dissipated naturally through the cooling oil circuit, the outer fin-shaped heat-conducting fins 19 and the inner fin-shaped heat-conducting fins 22. At the same time, the oil cooling components can be easily removed and only natural cooling can be performed. Air cooling requires the removal of the end oil circuit oil block 18, the oil circuit cooling pump exchange channel block 17, the end oil circuit oil baffle 21 and the insulating oil baffle transmission module 24, leaving only the inner fin-shaped heat-conducting fins 22, the outer fin-shaped heat-conducting fins 19 and the I-shaped insulating oil baffle body 20 to form an efficient air-cooled heat dissipation structure. The large area of ​​aluminum sheet can efficiently guide the low-voltage winding temperature, so air cooling is used to achieve a good heat dissipation effect.

[0094] The transformer low-voltage winding composite cooling strut structure of the embodiment of the present invention, when the oil circuit cooling circulation pump 5 is started, the oil cooling circuit is: oil circuit cooling circulation pump 5 → end oil circuit oil block 18 → oil circuit cooling pump exchange channel block 17 → cooling oil circuit in the strut body → main oil tank, forming a closed loop circulation.

[0095] A transformer cooling system includes the above-mentioned cooling brace structure and a temperature monitoring and speed control system. The temperature monitoring and speed control system 20 is electrically connected to the temperature sensor 13, the oil circuit cooling circulation pump 5 and the insulating oil baffle 27 in the cooling brace structure, and the temperature monitoring and speed control system 20 is configured as follows:

[0096] When the temperature sensor 13 detects that the temperature of the low-voltage winding 8 is lower than the second preset threshold, the oil circuit cooling circulation pump is shut down, and only the cooling oil circuit, the outer fin-shaped aluminum fins 19 and the inner fin-shaped aluminum fins 22 are used for natural heat dissipation;

[0097] When the temperature sensor 13 detects that the temperature of the low-voltage winding 8 is higher than the first preset threshold, the oil circuit cooling circulation pump 5 is controlled to operate so that the cooling oil circuit and the hollow cavity of the strut body form a full circulation cycle;

[0098] The temperature monitoring and speed control system 20 is also equipped with a turbulence compensation algorithm. According to the real-time flow data of the cooling oil circuit, the speed of the oil circuit cooling circulation pump 5 is dynamically adjusted to ensure the flow rate of the insulating oil in the serpentine oil circuit to maintain the turbulence enhancement effect of the turbulence enhancement rib 10. Specifically, the temperature monitoring and speed control system 20 can be selected from Danfoss AutomationDrive FC 602.

[0099] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A transformer low voltage winding composite cooling support structure, characterized in that: include: Iron core (1), high voltage winding (3), low voltage winding (8) and cooling stay unit, The low-voltage winding (8) is arranged between the iron core (1) and the high-voltage winding (3), and an insulating tube (12) is provided between the low-voltage winding (8) and the iron core (1); the side of the low-voltage winding (8) facing the high-voltage winding (3) is isolated from the high-voltage winding by an interphase baffle (10), and a predetermined distance is left between the interphase baffle (10) and the low-voltage winding (8) and the high-voltage winding (3); A cooling strut unit is provided on the periphery of the low-voltage winding (8), and the cooling strut unit comprises: a strut body, an outer fin-shaped heat-conducting fin (19) and an inner fin-shaped heat-conducting fin (22), wherein the outer fin-shaped heat-conducting fin (19) is provided on the side of the strut body facing the high-voltage winding (3); the inner fin-shaped heat-conducting fin (22) is provided on the side of the strut body facing the iron core (1); the strut body has a hollow cavity, and the hollow cavity is provided with a cooling oil circuit.

2. The transformer low-voltage winding composite cooling brace structure according to claim 1, characterized in that: The cooling support bar units are provided in plurality, and the cooling support bar units are metal-resin composite structures, and the cooling support bar units are evenly distributed in the circumferential direction of the low-voltage winding (8); the cooling oil circuit is arranged in a serpentine shape in the hollow cavity of the support bar body; the outer fin-shaped heat-conducting fins (19) and the inner fin-shaped heat-conducting fins (22) are made of aluminum alloy material; the support bar body, the outer fin-shaped heat-conducting fins (19) and the inner fin-shaped heat-conducting fins (22) are integrally formed by using modified epoxy resin through an in-mold injection molding process, and the modified epoxy resin is a high-strength heat-resistant insulating material.

3. The transformer low-voltage winding composite cooling brace structure according to claim 2, characterized in that: It also includes an oil circuit cooling circulation pump (5), wherein the inner surface of the channel of the serpentine cooling oil circuit is provided with turbulence enhancing ribs, the height of the turbulence enhancing ribs is 0.5-1mm, and the spacing between the turbulence enhancing ribs is 2-4mm; the cooling oil circuit is connected to the oil circuit cooling circulation pump (5) through end oil circuit oil blocks (18) at both ends, and the end oil circuit oil blocks (18) are connected to the oil circuit cooling circulation pump (5) through quick-connect connectors.

4. The transformer low-voltage winding composite cooling brace structure according to claim 1, characterized in that: Also included are end rings (6) and end ring mounting components, The end ring (6) comprises an upper end ring and a lower end ring, and the upper end ring and the lower end ring are respectively arranged on the top and bottom of the high-voltage winding (3) through an end ring mounting assembly; The end oil passage oil block (18) is fixedly connected to the cooling strut unit in the low-voltage winding (8) by bolts; the cooling strut unit is an I-shaped structure, and the inner fin-shaped aluminum wing (22) and the outer fin-shaped aluminum wing (19) are respectively connected on both sides of the web of the cooling strut unit; The upper wing plate and the lower wing plate of the cooling support bar unit extend axially along the low-voltage winding (8), and the width of the upper wing plate and the lower wing plate of the cooling support bar unit is consistent with the width of the low-voltage winding (8).

5. The transformer low-voltage winding composite cooling brace structure according to claim 1, characterized in that: The end of the low-voltage winding (8) is provided with a heat-resistant insulating oil baffle device (16), which includes an insulating oil baffle (27) and a heat-resistant oil baffle transmission module (16) for driving the insulating oil baffle to open and close. The heat-resistant oil baffle transmission module (16) comprises a motor, a transmission rod (25) and a transmission gear block (26), one end of the transmission rod (25) is fixed to the insulating oil baffle (27), and the other end of the transmission rod (25) is engaged with the transmission gear block (26); The transmission gear (28) cooperates with the transmission gear block (26), and a silicone sealing strip is provided on the edge of the insulating oil baffle (27) to cooperate with the end ring (6) to form a sealed oil circuit.

6. The transformer low-voltage winding composite cooling brace structure according to claim 1, characterized in that: The surface of the outer fin-shaped heat-conducting fin (19) is sprayed with a graphene heat-conducting coating; The inner fin-shaped heat-conducting fin (22) is provided with a wave-shaped guide groove; the outer fin-shaped heat-conducting fin (19) and the inner fin-shaped heat-conducting fin (22) are sealed at the end of the oil circuit through the end oil circuit oil blocking sheet (21).

7. The transformer low-voltage winding composite cooling brace structure according to claim 1, characterized in that: The support bar body, the outer fin-shaped heat-conducting fins (19) and the inner fin-shaped heat-conducting fins (22) are fixed to a dedicated mold, poured with epoxy resin, and cooled to form an I-shaped insulating oil-blocking structure (20).

8. The transformer low-voltage winding composite cooling brace structure according to claim 7, characterized in that: The I-shaped insulating oil retaining structure (20) has a built-in temperature sensor; When the temperature exceeds a first preset threshold, the oil circuit cooling circulation pump (5) is started; When the temperature is lower than a second preset threshold, the oil circuit cooling circulation pump (5) is shut down, and heat is naturally dissipated only through the cooling oil circuit, the outer fin-shaped heat conducting fins (19), and the inner fin-shaped heat conducting fins (22).

9. The transformer low-voltage winding composite cooling brace structure according to claim 6, characterized in that: When the oil cooling circulation pump (5) is started, the oil cooling circuit is: oil cooling circulation pump (5) → end oil passage oil block (18) → oil cooling pump exchange channel block (17) → cooling oil circuit in the strut body → main oil tank, forming a closed loop.

10. A transformer cooling system, comprising the cooling brace structure according to any one of claims 1 to 9, characterized in that: The system further comprises a temperature monitoring and speed regulating system, wherein the temperature monitoring and speed regulating system (20) is electrically connected to the temperature sensor (13), the oil circuit cooling circulation pump (5) and the insulating oil baffle (27) in the cooling support structure, and the temperature monitoring and speed regulating system (20) is configured as follows: When the temperature sensor (13) detects that the temperature of the low-voltage winding (8) is lower than a second preset threshold, the oil circuit cooling circulation pump is shut down, and natural heat dissipation is performed only through the cooling oil circuit, the outer fin-shaped aluminum fins (19), and the inner fin-shaped aluminum fins (22); When the temperature sensor (13) detects that the temperature of the low-voltage winding (8) is higher than a first preset threshold, the oil circuit cooling circulation pump (5) is controlled to operate so that the cooling oil circuit and the hollow cavity of the strut body form a full circulation cycle; The temperature monitoring and speed regulation system (20) is also equipped with a turbulence compensation algorithm, which dynamically adjusts the rotation speed of the oil circuit cooling circulation pump (5) according to the real-time flow data of the cooling oil circuit, thereby ensuring the flow rate of the insulating oil in the serpentine oil circuit to maintain the turbulence enhancement effect of the turbulence enhancement rib (10).

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