Photovoltaic grid-connected low-loss boosting transformer integrated with magnetic shielding structure

Abstract

The invention relates to the technical field of photovoltaic transformers, and discloses a photovoltaic grid-connected low-loss boosting transformer fused with a magnetic shielding structure, which comprises a transformer shell and a transformer winding arranged in an inner cavity of the transformer shell, and a side surface outer layer shielding plate is arranged on the side surface of the transformer winding; and a self-adaptive heat dissipation structure is arranged on the side surface outer layer shielding plate. According to the invention, the self-adaptive heat dissipation structure integrated on the outer shielding plate on the side surface is matched with the cooling space arranged on the outer side of the transformer shell, so that heat generated by leakage flux eddy current and transformer winding radiation can be accurately and efficiently taken away by a forcibly circulated heat-conducting medium at a position closest to a heat source; heat exchange of heat in a core area is achieved, the hot-spot temperature of a transformer winding is greatly reduced, the heat dissipation efficiency and overload capacity of the transformer are improved, meanwhile, perfect dynamic matching of the heat dissipation capacity and actual loads is achieved, and energy conservation and consumption reduction are achieved to the maximum extent while the safety of the transformer is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic transformer technology, and in particular to a low-loss step-up photovoltaic grid-connected transformer with integrated magnetic shielding structure. Background Technology

[0002] As a core piece of equipment in the power system, the stable operation of power transformers is crucial. For large-capacity transformers, the huge leakage magnetic field generated by the windings can cause local overheating of metal structural components such as the oil tank, increasing losses. Therefore, installing a magnetic shielding structure composed of high permeability materials (such as silicon steel sheets) or high conductivity materials (such as copper plates) outside the windings to suppress leakage magnetic field is a mature technology to ensure the safe operation of transformers. In photovoltaic grid-connected systems, step-up transformers play a key role in raising the low voltage output of the photovoltaic array to the grid voltage level, and are a necessary link in realizing energy grid connection. Photovoltaic power generation is intermittent and fluctuating, which means that grid-connected transformers must frequently withstand the drastic load fluctuations caused by transient changes in solar irradiance. This places more stringent requirements on the leakage magnetic field suppression and heat dissipation capabilities of transformers than on traditional transformers.

[0003] However, existing technologies have certain shortcomings in addressing the unique characteristics of photovoltaic grid-connected scenarios: First, traditional magnetic shielding structures are usually only static shielding components, and their design is independent of the heat dissipation system. The heat generated by eddy current losses on the shielding body becomes waste heat that needs to be passively dissipated, increasing the heat dissipation burden of the core area and failing to cope with the dynamic thermal shock caused by load fluctuations. Second, existing forced circulation cooling methods, such as cooling transformer oil by drawing it from an external oil pump and then circulating it, are effective, but their operation mode is relatively crude. Faced with the constant instability of photovoltaic power generation loads, such cooling systems often need to operate at a constant high power for a long time to ensure safety during peak periods, resulting in huge pumping energy consumption during most medium and low load periods. This reduces the overall economic benefits and energy utilization efficiency of photovoltaic power plants and fails to achieve refined and intelligent management of heat dissipation resources. Summary of the Invention

[0004] The technical problem to be solved by this invention is that the existing technology, which uses static magnetic shielding and extensive forced cooling, cannot adapt to photovoltaic load fluctuations, resulting in heavy heat dissipation burden and high energy consumption. To address this, we propose a photovoltaic grid-connected low-loss step-up transformer that integrates a magnetic shielding structure.

[0005] To achieve the above objectives, this application adopts the following technical solution: a photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure, including a transformer housing and a transformer winding disposed in the inner cavity of the transformer housing, wherein a side outer shielding plate is disposed on the side of the transformer winding; An adaptive heat dissipation structure is provided on the outer side shielding plate. The adaptive heat dissipation structure includes a channel located inside the outer side shielding plate for the passage of a heat-conducting medium. The upper and lower ends of the outer side shielding plate are respectively provided with interfaces communicating with the channel. A storage cavity is provided inside the outer side shielding plate. A phase change material is provided inside the storage cavity. A movable cavity is provided at the bottom of the storage cavity. A telescopic component corresponding to the movable cavity is installed at the bottom of the storage cavity. A drive component that is linked with the telescopic component and used to adjust the inner diameter or length of the channel is provided at one end of the movable cavity. The transformer casing has a cooling space on its side for cooling the heat transfer medium. An oil pump corresponding to the cooling space is installed on the outside of the transformer casing. The interface at the upper end of the outer shielding plate on the side is connected to the cooling space through a first pipe, and the interface at the lower end of the outer shielding plate on the side is connected to the output end of the oil pump through a second pipe. The input end of the oil pump is connected to the cooling space, thereby realizing the circulation of the heat transfer medium.

[0006] Preferably, the cooling space includes a cooling box located on the side of the transformer housing, an oil storage tank for storing heat transfer medium is located at the upper end of the inner side of the cooling box, a cooling pipe is connected to the bottom of the oil storage tank, the lower end of the cooling pipe is connected to the input end of the oil pump, and a cooling fan is installed on the cooling box.

[0007] Preferably, the channel for the passage of the heat-conducting medium includes a heat dissipation channel disposed inside the outer shielding plate on the side, with the upper and lower ends of the heat dissipation channel respectively connected to two interfaces.

[0008] Preferably, the channel for the heat-conducting medium includes a secondary heat dissipation channel and a main heat dissipation channel disposed on the inner side of the outer shielding plate, and the upper and lower ends of the main heat dissipation channel and the secondary heat dissipation channel are connected to the interfaces at both ends.

[0009] Preferably, the drive assembly includes a rack disposed at one end of the telescopic member, a sealing ball is movably sealed on the inner side of the heat dissipation channel, the sealing ball is provided with a first through hole, and a gear that meshes with the rack is provided at one end of the sealing ball.

[0010] Preferably, the drive assembly includes a traction rod movably disposed at one end of the telescopic member, a sealing plate movably sealed on the inner side of one end of the heat dissipation channel, a second through hole provided on the sealing plate, and the end of the traction rod away from the telescopic member being movably connected to one end of the sealing plate.

[0011] Preferably, the drive assembly includes a sealing ball that is movably and sealed in the main heat dissipation channel or the secondary heat dissipation channel, the sealing ball having a first through hole, a rack at one end of the telescopic member, and a gear that meshes with the rack at one end of the sealing ball.

[0012] Preferably, the drive assembly includes a sealing plate that is movably sealed in the main heat dissipation channel or the secondary heat dissipation channel, the sealing plate having a second through hole, and a traction rod movably disposed at one end of the telescopic member, the end of the traction rod away from the telescopic member being movably connected to one end of the sealing plate.

[0013] Preferably, an elastic element for resetting the telescopic component is provided on the inner side of the movable cavity.

[0014] Preferably, the phase change material in the storage cavity is paraffin.

[0015] The technical effects and advantages of this invention are as follows: In this invention, by integrating an adaptive heat dissipation structure on the outer side shielding plate in conjunction with a cooling space on the outside of the transformer casing, the heat generated by leakage magnetic eddy currents and transformer winding radiation can be precisely and efficiently carried away by a forced-circulation heat-conducting medium at the location closest to the heat source. This achieves heat exchange in the core area, significantly reducing the hot spot temperature of the transformer windings and improving the transformer's heat dissipation efficiency and overload capacity. Simultaneously, the waste heat generated by the outer side shielding plate, as a heat dissipation element, is actively utilized, resulting in a more compact overall transformer structure. This achieves a high degree of functional integration and synergy. Under normal load, it can automatically switch to an energy-saving circulation mode, significantly reducing the daily operating energy consumption of the oil pump. When factors such as cloud cover cause a sudden surge in load and a sharp increase in temperature, the mechanical force generated by the phase change material can automatically switch to a full-flow, high-intensity targeted heat dissipation mode. This purely physical adaptive adjustment, without the need for external sensors and controllers, not only greatly improves the reliability of the system but also achieves a perfect dynamic match between heat dissipation capacity and actual load. While ensuring transformer safety, it maximizes energy saving and consumption reduction. Attached Figure Description

[0016] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a structural schematic diagram of the present invention in its disassembled state; Figure 3 This is a structural schematic diagram of the cooling box of the present invention in its disassembled state; Figure 4 This is a schematic diagram of the overall structure of the transformer winding, the side outer shielding plate, and the end outer shielding plate of the present invention. Figure 5 This is a structural diagram of the side outer shielding plate and the end outer shielding plate of the present invention in a disassembled state; Figure 6 For the present invention Figure 5A structural diagram from another perspective based on the above; Figure 7 This is a schematic diagram of the structure of the heat dissipation channel and the sealing ball in the outer shielding plate on the side of the present invention. Figure 8 This is a schematic diagram of the structure of the heat dissipation channel and the sealing plate in the present invention. Figure 9 This is a schematic diagram of the structure of the main heat dissipation channel, the secondary heat dissipation channel, and the sealing ball in the present invention. Figure 10 This is a schematic diagram of the structure of the main heat dissipation channel, the secondary heat dissipation channel, and the sealing plate of the present invention.

[0017] Legend: 1. Transformer housing; 2. Cooling box; 3. Radiator fan; 4. Heat sink; 5. Oil pump; 6. Side outer shielding plate; 7. End outer shielding plate; 8. Oil reservoir; 9. Heat sink plate; 10. Mounting slot; 11. Cooling pipe; 12. Cutout; 13. Top collecting pipe; 14. Outlet; 15. Bottom collecting pipe; 16. Inlet; 17. Transformer winding; 18. Side inner shielding plate; 19. End inner shielding plate; 20. Storage cavity; 21. Heat dissipation channel; 22. Sealing ball; 23. First through hole; 24. Telescopic component; 25. Elastic component; 26. Rack; 27. Gear; 28. Movable cavity; 29. ​​Sealing plate; 30. Second through hole; 31. Traction rod; 32. Main heat dissipation channel; 33. Interface; 34. Secondary heat dissipation channel. Detailed Implementation

[0018] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0019] Reference Figures 1-10As shown, the present invention provides a technical solution: a photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure, including a transformer housing 1 and a transformer winding 17 disposed in the inner cavity of the transformer housing 1. A side outer shielding plate 6 is disposed on the side of the transformer winding 17, surrounding the transformer winding 17. The side outer shielding plate 6 is composed of multiple high-conductivity oxygen-free copper or high-purity aluminum alloy plates spliced ​​together, with vertical insulating gaps between each plate filled with epoxy board or insulating paperboard to cut off macroscopic eddy current loops. A side inner shielding plate 18 is provided between the outer shielding plate 6 and the transformer winding 17. The side inner shielding plate 18 also surrounds the transformer winding 17, and gaps exist between it and both the side outer shielding plate 6 and the transformer winding 17. The side inner shielding plate 18 is made of high-saturation magnetic induction intensity grain-oriented silicon steel sheet, preferably 30Q130 or higher grade, with a material similar to the core material of the transformer winding 17. Vertical insulating gaps are also left between each plate, filled with epoxy board or insulating paperboard to cut off the macroscopic eddy current loop. Both the upper and lower ends are provided with end inner shielding plates 19, the material of which is the same as that of the side inner shielding plate 18. An end outer shielding plate 7 is provided on the side of the end inner shielding plate 19 away from the transformer winding 17, the material of which is the same as that of the side outer shielding plate 6. Both the end outer shielding plate 7 and the end inner shielding plate 19 are annular planar cover plates with a central hole and at least one radial cut. The central hole is used for lead wires to pass through, and the radial cut is also used to block the annular current. The end inner shielding plate 19 and the side inner shielding plate 18... The 8 is separated from the transformer winding 17 by an insulating support strip. This gap also serves as the main cooling oil channel. The end inner shielding plate 19, the end outer shielding plate 7, the side inner shielding plate 18, and the side outer shielding plate 6 are all fixed to the iron yoke clamps at the upper and lower ends of the transformer winding 17 by non-magnetic stainless steel or high-strength engineering plastic fasteners to ensure structural stability. The gaps between the end outer shielding plate 7 and the end inner shielding plate 19, and between the side inner shielding plate 18 and the side outer shielding plate 6, are also separated by insulating support strips to form oil channels.

[0020] In use, the silicon steel shunts of the inner side shielding plate 18 and the inner end shielding plates 19 at both ends guide most of the leakage magnetic flux back to the main iron core, reducing leakage at the source. The residual leakage magnetic flux passing through the inner side shielding plate 18 and the inner end shielding plate 19 induces strong eddy currents on the high conductivity copper plates of the outer side shielding plate 6 and the outer end shielding plate 7. The reverse magnetic field generated further cancels the leakage magnetic flux, achieving efficient shielding.

[0021] To adaptively adjust the heat dissipation effect, an adaptive heat dissipation structure is provided on the outer side shielding plate 6. In a preferred embodiment, the adaptive heat dissipation structure includes a channel located inside the outer side shielding plate 6 for the passage of a heat-conducting medium. The heat-conducting medium is preferably transformer oil, the same as that inside the transformer housing 1. Interfaces 33 communicating with the channel are provided at the upper and lower ends of the outer side shielding plate 6. A storage cavity 20 is provided inside the outer side shielding plate 6, and a phase change material is provided within the storage cavity 20. The phase change material is preferably industrial paraffin wax, specifically paraffin wax with a melting point of approximately 85°C. When the photovoltaic power station is operating normally and stably, the transformer temperature rise is stable, and the core area temperature is below 85°C, thus the paraffin wax remains solid. However, when the load increases sharply, the transformer loss spikes rapidly, and the temperature of the transformer winding 17 and the outer side shielding plate 6 will suddenly increase. The temperature exceeds 85°C, causing the paraffin wax to melt and absorb heat. A movable cavity 28 is located at the bottom of the storage cavity 20. A telescopic component 24 corresponding to the movable cavity 28 is installed at the bottom of the storage cavity 20. The telescopic component 24 is preferably a metal bellows with a closed bottom, or other telescopic structures can be used to ensure that the paraffin wax can be pushed and extended when melting. One end of the movable cavity 28 is equipped with a drive component that is linked to the telescopic component 24 and used to adjust the inner diameter or length of the channel. This ensures a low flow rate of the heat transfer medium through the channel under normal stable conditions, and increases the flow rate when the load increases significantly. To facilitate the reset of the telescopic component 24, an elastic component 25 for resetting the telescopic component 24 is provided inside the movable cavity 28. The elastic component 25 is preferably a spring, made of a temperature-sensitive material, and ensures that the telescopic component 24 can be reset when the paraffin wax solidifies.

[0022] It should be noted that paraffin wax, as an excellent electrical insulator and chemically inert substance, is perfectly compatible with transformer oil and internal components. This material has the unique physical property of absorbing or releasing a large amount of latent heat during solid-liquid phase transition while maintaining its own temperature. It is safely encapsulated in an independent storage cavity 20 within the outer side shielding plate 6. It neither participates in conduction nor interferes with the electromagnetic shielding function of the outer side shielding plate 6 in any way to generate eddy currents to cancel leakage magnetic flux, thus ensuring the absolute safety of the transformer's electrical performance. More importantly, it not only changes its shape according to temperature but also acts as a heat buffer, capable of absorbing a huge amount of peak heat during load impacts. This effectively suppresses the rapid rise in the hot spot temperature of the transformer winding 17, providing the transformer with valuable dynamic thermal margin and greatly enhancing the reliability and safety of the equipment in the face of extreme fluctuations in photovoltaic power generation.

[0023] Furthermore, to enable the heat transfer medium to circulate through the channel, a cooling space for cooling the heat transfer medium is provided on the side of the transformer housing 1. An oil pump 5 corresponding to the cooling space is located on the outside of the transformer housing 1. The upper interface 33 of the outer side shielding plate 6 is connected to the cooling space via a first pipe, and the lower interface 33 of the outer side shielding plate 6 is connected to the output end of the oil pump 5 via a second pipe. The input end of the oil pump 5 is connected to the cooling space, thereby enabling the circulation of the heat transfer medium. The cooling space includes a cooling box 2 located on the side of the transformer housing 1. An oil storage tank 8 for storing the heat transfer medium is located at the upper inner side of the cooling box 2. A cooling pipe 11, which is S-shaped, is connected to the bottom of the oil storage tank 8. The lower end of the cooling pipe 11 is connected to the input end of the oil pump 5. The cooling box 2 is equipped with a cooling system for cooling the heat transfer medium. The internal cooling fan 3 includes a first pipe comprising a top pipe 13 located on the upper end of the outer side shielding plate 6 and connected to the interface 33 at the upper end of the outer side shielding plate 6. The top pipe 13 has an outlet 14 extending to the outside of the transformer housing 1 and connected to the oil tank 8. The second pipe comprises a bottom pipe 15 located on the lower end of the outer side shielding plate 6 and connected to the interface 33 at the lower end of the outer side shielding plate 6. The bottom pipe 15 has an inlet 16 extending to the outside of the transformer housing 1 and connected to the output end of the oil pump 5. To further improve the cooling effect in the cooling box 2, heat dissipation plates 9 are provided on both sides of the cooling pipe 11 at the lower end of the inner side of the cooling box 2. The opposite sides of the two heat dissipation plates 9 are provided with mounting grooves 10 for wrapping the cooling pipe 11. The ends of the heat dissipation plates 9 are provided with heat dissipation fins 4 extending to the outside of the cooling box 2.

[0024] The aforementioned channels for the passage of the heat-conducting medium include at least two embodiments: like Figures 7-8 As shown, the channel in the first embodiment includes a heat dissipation channel 21 disposed inside the outer shielding plate 6 on the side, and the upper and lower ends of the heat dissipation channel 21 are respectively connected to two interfaces 33.

[0025] like Figures 9-10 As shown, the second embodiment of the channel includes a secondary heat dissipation channel 34 and a main heat dissipation channel 32 disposed inside the outer shielding plate 6 on the side. The upper and lower ends of the main heat dissipation channel 32 and the secondary heat dissipation channel 34 are connected to the interfaces 33 at both ends. Normally, only one is in normal use.

[0026] The aforementioned driver components also include at least two embodiments: like Figure 7As shown, when the drive assembly of the first embodiment cooperates with the channel of the first embodiment, the drive assembly includes a rack 26 disposed at one end of the telescopic member 24, a sealing ball 22 rotatably disposed on the inner side of the heat dissipation channel 21, a first through hole 23 disposed on the sealing ball 22, and a gear 27 meshing with the rack 26 disposed at one end of the sealing ball 22. Thus, when the paraffin melts and pushes the telescopic member 24 to move, it can drive the rack 26 to move synchronously. Then, the rack 26 drives the gear 27 to rotate, and the gear 27 drives the sealing ball 22 to rotate, so that the overlapping part of the first through hole 23 and the heat dissipation channel 21 increases, thereby increasing the flow rate.

[0027] like Figure 8 As shown, when the drive assembly of the second embodiment cooperates with the first embodiment of the channel, the drive assembly includes a traction rod 31 rotatably disposed at one end of the telescopic member 24, a sealing plate 29 movably and sealingly disposed on the inner side of one end of the heat dissipation channel 21, and a second through hole 30 disposed on the sealing plate 29. The end of the traction rod 31 away from the telescopic member 24 is rotatably connected to one end of the sealing plate 29, so that when the paraffin melts, it drives the telescopic member 24 to move, the telescopic member 24 drives the traction rod 31 to change its tilt angle, and then pushes the sealing plate 29 to move. The sealing plate 29 drives the second through hole 30 to increase the matching part with the heat dissipation channel 21, thereby increasing the flow rate.

[0028] like Figure 9 As shown, when the drive component of the first embodiment cooperates with the channel of the second embodiment, the sealing ball 22 is simply rotated and placed in the main heat dissipation channel 32 or the secondary heat dissipation channel 34. Initially, the sealing ball 22 is in a blocking state against the main heat dissipation channel 32 or the secondary heat dissipation channel 34. At high temperature, the paraffin melts and pushes the telescopic member 24 to move. The telescopic member 24 realizes the rotation of the sealing ball 22 through the rack 26 and the gear 27, so that the first through hole 23 on the sealing ball 22 matches the main heat dissipation channel 32 or the secondary heat dissipation channel 34, thereby increasing the path of the heat conduction medium.

[0029] like Figure 10 As shown, when the second implementation of the drive component cooperates with the second embodiment of the channel, the sealing plate 29 only needs to be movably set inside one end of the main heat dissipation channel 32 or the secondary heat dissipation channel 34. Initially, the main heat dissipation channel 32 or the secondary heat dissipation channel 34 is blocked by the sealing plate 29. At high temperature, the paraffin melts, and the telescopic member 24 drives the traction rod 31 to change its tilt angle. Then, the sealing plate 29 drives the second through hole 30 to match the main heat dissipation channel 32 or the secondary heat dissipation channel 34, thereby increasing the path of the heat conduction medium.

[0030] The overall working principle is as follows: First, the double-layer magnetic shielding structure set around the transformer winding 17 works in tandem. The silicon steel shunt screens of the inner side shielding plate 18 and the inner end shielding plates 19 at both ends guide most of the leakage flux back to the main iron core, reducing leakage at the source. The residual leakage flux passing through the inner side shielding plate 18 and the inner end shielding plate 19 induces strong eddy currents on the high conductivity copper plates of the outer side shielding plate 6 and the outer end shielding plate 7. The reverse magnetic field generated further cancels the leakage flux, achieving efficient shielding. At the same time, the heat dissipation system starts to work. Under the stable and normal operating conditions of the photovoltaic system, the temperature of the transformer core area is generally below 85°C. At this time, the phase change material encapsulated in the storage cavity 20 of the outer side shielding plate 6 is in a solid state. The driving component drives the channel in the outer side shielding plate 6 to switch to a small inner diameter or short path mode, and the oil pump 5 maintains low power consumption. In the basic cycle, the heat transfer medium in the oil tank 8 enters the cooling pipe 11 and is cooled by the cooperation of the heat sink 4, heat sink 9, and cooling fan 3. Then, it is pumped into the bottom collection pipe 15 by the oil pump 5, enters the channel through the interface 33 at the bottom of the side outer shield plate 6, and then enters the top collection pipe 13 from the interface 33 at the top of the side outer shield plate 6. Finally, it returns to the oil tank 8. When the photovoltaic system experiences a surge due to sudden weather changes, causing the transformer load to surge and the temperature to exceed the threshold, the phase change material melts and expands in volume. The resulting mechanical thrust drives the drive components to automatically expand the inner diameter of the channel or extend the channel path. A large amount of heat transfer medium washes over the inner wall of the side outer shield plate 6 where the heat is concentrated, efficiently carrying away the peak heat until the temperature drops and the phase change material re-solidifies. Then, it automatically returns to the energy-saving small inner diameter or short path mode, thus completing a complete adaptive heat dissipation cycle without external intervention.

[0031] It should be noted that oil pump 5 is a centrifugal fluid pump. In energy-saving mode, whether by shrinking the inner diameter of the channel or increasing the number of channels, there will be a high system resistance. Faced with this high resistance, the physical characteristics of the centrifugal oil pump determine that its outlet flow rate will drop sharply. Although the pump needs to maintain a certain pressure, the significant reduction in flow rate makes the product of total flow rate and pressure very small. Therefore, the actual operating power of oil pump 5 is also reduced to the minimum level, achieving energy saving. Conversely, when switching to a high-efficiency heat dissipation mode with a large inner diameter or multiple flow channels, the system resistance drops sharply, and oil pump 5 can smoothly pump out a huge flow rate of heat transfer medium. At this time, although the pressure is not high, the huge flow rate makes the product of flow rate and pressure very large, and oil pump 5 also enters a high power consumption state. Therefore, this invention actively reduces the workload of oil pump 5 through a high-resistance throttling design.

[0032] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure, characterized in that, It includes a transformer housing (1) and a transformer winding (17) disposed in the inner cavity of the transformer housing (1), wherein the side of the transformer winding (17) is provided with a side outer shielding plate (6). An adaptive heat dissipation structure is provided on the outer side shielding plate (6). The adaptive heat dissipation structure includes a channel provided on the inner side of the outer side shielding plate (6) for passing a heat-conducting medium. The upper and lower ends of the outer side shielding plate (6) are respectively provided with interfaces (33) communicating with the channel. A storage cavity (20) is provided on the inner side of the outer side shielding plate (6). A phase change material is provided in the inner cavity of the storage cavity (20). A movable cavity (28) is provided at the bottom end of the storage cavity (20). A telescopic component (24) corresponding to the movable cavity (28) is installed at the bottom end of the storage cavity (20). A drive component that is linked with the telescopic component (24) and used to adjust the inner diameter or length of the channel is provided at one end of the movable cavity (28). The transformer housing (1) has a cooling space on its side for cooling the heat transfer medium. An oil pump (5) corresponding to the cooling space is provided on the outside of the transformer housing (1). The interface (33) at the upper end of the outer shield plate (6) on the side is connected to the cooling space through a first pipe. The interface (33) at the lower end of the outer shield plate (6) on the side is connected to the output end of the oil pump (5) through a second pipe. The input end of the oil pump (5) is connected to the cooling space, thereby realizing the circulation of the heat transfer medium.

2. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to claim 1, characterized in that: The cooling space includes a cooling box (2) located on the side of the transformer housing (1). An oil storage tank (8) for storing heat transfer medium is provided at the upper end of the inner side of the cooling box (2). A cooling pipe (11) is connected to the bottom of the oil storage tank (8). The lower end of the cooling pipe (11) is connected to the input end of the oil pump (5). A cooling fan (3) is provided on the cooling box (2).

3. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to claim 1, characterized in that: The channel for the passage of the heat-conducting medium includes a heat dissipation channel (21) disposed inside the outer shield plate (6) on the side, and the upper and lower ends of the heat dissipation channel (21) are respectively connected to two interfaces (33).

4. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to claim 1, characterized in that: The channels for the heat transfer medium include a secondary heat dissipation channel (34) and a main heat dissipation channel (32) located inside the outer shielding plate (6) on the side. The upper and lower ends of the main heat dissipation channel (32) and the secondary heat dissipation channel (34) are connected to the interfaces (33) at both ends.

5. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to claim 3, characterized in that: The drive assembly includes a rack (26) disposed at one end of the telescopic member (24), and a sealing ball (22) is movably sealed on the inner side of the heat dissipation channel (21). A first through hole (23) is provided on the sealing ball (22), and a gear (27) meshing with the rack (26) is provided at one end of the sealing ball (22).

6. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to claim 3, characterized in that: The drive assembly includes a traction rod (31) movably disposed at one end of the telescopic member (24), a sealing plate (29) is movably sealed on the inner side of one end of the heat dissipation channel (21), a second through hole (30) is provided on the sealing plate (29), and the end of the traction rod (31) away from the telescopic member (24) is movably connected to one end of the sealing plate (29).

7. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to claim 4, characterized in that: The drive assembly includes a sealing ball (22) that is movably sealed in the main heat dissipation channel (32) or the secondary heat dissipation channel (34). The sealing ball (22) has a first through hole (23). One end of the telescopic member (24) is provided with a rack (26), and one end of the sealing ball (22) is provided with a gear (27) that meshes with the rack (26).

8. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to claim 4, characterized in that: The drive assembly includes a sealing plate (29) that is movably sealed in the main heat dissipation channel (32) or the secondary heat dissipation channel (34). The sealing plate (29) has a second through hole (30). A traction rod (31) is movably provided at one end of the telescopic member (24). The end of the traction rod (31) away from the telescopic member (24) is movably connected to one end of the sealing plate (29).

9. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to any one of claims 5-8, characterized in that: The inner side of the active cavity (28) is provided with an elastic element (25) for resetting the telescopic element (24).

10. The photovoltaic grid-connected low-loss step-up transformer with integrated magnetic shielding structure according to any one of claims 5-8, characterized in that: The phase change material in the storage cavity (20) is paraffin.

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