Short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation

Abstract

This invention discloses a short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation, comprising: a transformer oil tank and a heat sink. The heat sink is hollow and communicates with the interior of the transformer oil tank. Several flat oil cylinders are connected to the outer end of the heat sink, and the inner ends of the flat oil cylinders communicate with the heat sink. A piston is slidably connected inside each flat oil cylinder. A connecting rod is perpendicularly connected to the piston's end face facing away from the transformer oil tank, and the connecting rod extends from the outer end of the flat oil cylinder. An end plate is provided on the outer side of the outer end of the flat oil cylinder. Several fan blades are rotatably connected to the outer surface of the heat sink. Gears are coaxially mounted on the shafts of the fan blades. Racks are connected to the end plate facing the transformer oil tank, and the racks mesh with the gears on the shafts of the fan blades. This invention converts the thermal expansion energy of the transformer oil into the kinetic energy of the fan blades, thus improving the heat dissipation effect of the heat sink.

Description

Technical Field

[0001] This invention relates to the field of transformer technology. More specifically, this invention relates to a short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation. Background Technology

[0002] Oil-immersed transformers are crucial equipment in power distribution systems for industrial and mining enterprises and civil buildings, reducing 10kV voltage to the 230V bus voltage used by users. These products are suitable for AC 50Hz, with a maximum three-phase rated capacity of 2500kVA. They can be used both indoors and outdoors. For capacities of 315kVA and below, they can be pole-mounted, with an ambient temperature not exceeding 40℃ and not falling below -25℃. Photovoltaic power generation scenarios are generally located in environments with abundant solar energy resources. Therefore, existing silicon steel core oil-immersed transformers are not well-suited for photovoltaic power generation scenarios. They are prone to overheating, which can damage internal components. In extreme cases, this can lead to short circuits, causing the transformer oil to decompose and vaporize, placing extreme pressure on the transformer tank. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] To achieve these objectives and other advantages according to the present invention, a short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation is provided, comprising: a transformer tank, a transformer core disposed within the transformer tank, and a tank cover disposed on the top of the transformer tank. The tank cover is provided with a high-voltage terminal, a low-voltage terminal, a tap changer, an oil conservator, a gas relay, and an explosion-proof pipe. The side wall of the transformer tank is provided with heat sinks, the heat sinks are hollow inside, and the heat sinks are in communication with the interior of the transformer tank.

[0005] The outer end of the heat sink is connected with several flat oil cylinders evenly spaced from top to bottom. The inner end of the flat oil cylinder is connected to the heat sink. A piston is slidably connected inside the flat oil cylinder. A connecting rod is vertically connected to the end face of the piston facing away from the transformer oil tank. The connecting rod passes out from the outer end of the flat oil cylinder. An end plate is provided on the outer side of the outer end of the flat oil cylinder. The connecting rods in the several flat oil cylinders are all connected to the end plate.

[0006] The outer side of the heat sink is rotatably connected with several fan blades at even intervals from top to bottom. Gears are coaxially arranged on the rotating shaft of the fan blades. Several horizontally arranged racks are connected to the plate surface of the end plate facing the transformer oil tank. The racks mesh with the gears on the rotating shafts of the fan blades respectively.

[0007] The outer end of the flat oil cylinder is provided with a pressure balance hole communicating with its interior. A first spring is also provided between the inner wall of the outer end of the flat oil cylinder and the piston inside. When the transformer oil is heated and expands, the transformer oil pushes the piston away from the transformer oil tank and enters the flat oil cylinder to increase the heat dissipation surface. The piston compresses the first spring and drives the rack to move. The rack drives the gear to rotate, and the gear drives the fan blade to rotate to dissipate heat. When the transformer oil cools down and contracts, the first spring drives the piston to push the liquid transformer oil in the flat oil cylinder back to the transformer oil tank.

[0008] Preferably, a bearing is provided on the outer surface of the heat sink, and the shaft of the fan blade is fixedly connected to the central hole of the bearing. The fan blade includes:

[0009] The annular part has a first blind hole radially opened on its inner wall. A second spring is installed in the first blind hole. A cylindrical pin is connected to the front end of the second spring. A second blind hole is opened on the rotating shaft of the fan blade opposite to the first blind hole. The front end of the cylindrical pin is inserted into the second blind hole.

[0010] Several blades are evenly spaced on the circumferential surface of the annular portion, and a counterweight is provided at the end of each blade.

[0011] When the gear drives the fan blade to rotate at a certain speed, the centrifugal force of the cylindrical pin is greater than the sum of the elastic force of the second spring and its own weight, causing the front end of the cylindrical pin to retract from the second blind hole to the first blind hole. Under the inertia of the counterweight, several blades drive the annular part to rotate around the axis of the fan blade.

[0012] Preferably, a first annular stop is provided on the rotating shaft of the fan blade to abut against the rear end of the annular portion, and a second stop is threadedly connected to the front end of the rotating shaft to abut against the front end of the annular portion.

[0013] Preferably, the surfaces of the rotating shaft, the first annular stop, and the second stop that abut against the annular portion are all coated with a wear-resistant and drag-reducing coating.

[0014] Preferably, the inner wall of the transformer tank is provided with a grid-like reinforcing rib.

[0015] Preferably, angle steel is provided at the angle between two adjacent walls inside the transformer tank to strengthen the connection.

[0016] Preferably, the top edge of the transformer tank is provided with a flange, and the tank cover is bolted to the flange.

[0017] Preferably, a support rod is provided on the outer top surface of the box cover, and a heat insulation plate is provided on the support rod to cover the transformer.

[0018] Preferably, the bottom of the transformer oil tank is fixed on a liftable platform.

[0019] The present invention includes at least the following beneficial effects: the photovoltaic power generation silicon steel core oil-immersed transformer can convert the thermal expansion energy of the transformer oil into the kinetic energy of the fan blades, helping the heat sink to improve the heat dissipation effect. Simultaneously, the sliding characteristics of the piston within the flat oil cylinder allow the space for transformer oil in the transformer tank to vary with pressure, reducing the pressure load on the transformer tank under high oil temperature conditions and improving its anti-expansion capability. Furthermore, the entry of transformer oil into the flat oil cylinder increases the heat dissipation area, further enhancing the heat dissipation effect. Therefore, the structural improvement of the transformer tank comprehensively enhances the short-circuit withstand capability of the photovoltaic power generation silicon steel core oil-immersed transformer, achieving multiple benefits in one fell swoop.

[0020] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the side structure of a silicon steel core oil-immersed transformer in the prior art;

[0022] Figure 2 This is a top view of the transformer tank according to an embodiment of the present invention;

[0023] Figure 3 This is a front view of the side of the heat sink according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the internal structure of the heat sink and flat oil cylinder described in the embodiments of the present invention;

[0025] Figure 5 This is a schematic diagram of the internal structure of the fan blade according to an embodiment of the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0027] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] like Figures 1-5 As shown, the present invention provides a short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation, comprising: a transformer tank 1, a transformer core disposed within the transformer tank 1, and a tank cover disposed on the top of the transformer tank 1. The tank cover is provided with a high-voltage terminal, a low-voltage terminal, a tap changer, an oil conservator, a gas relay, and an explosion-proof pipe. The side wall of the transformer tank is provided with a heat sink 2, the heat sink 2 being hollow inside and communicating with the interior of the transformer tank.

[0029] The outer end of the heat sink 2 is evenly spaced from top to bottom with several flat oil cylinders 3. The inner end of the flat oil cylinder 3 is connected to the heat sink 2. A piston 4 is slidably connected inside the flat oil cylinder 3. A connecting rod 5 is vertically connected to the end face of the piston 4 facing away from the transformer oil tank 1. The connecting rod 5 passes through the outer end of the flat oil cylinder 3. An end plate 6 is provided on the outer side of the outer end of the flat oil cylinder 3. The connecting rods 5 in the several flat oil cylinders 3 are all connected to the end plate 6.

[0030] The outer side of the heat sink 2 is rotatably connected with a number of fan blades 7 at even intervals from top to bottom. A gear 8 is coaxially arranged on the rotating shaft 13 of the fan blades 7. A number of horizontally arranged racks 9 are connected to the plate surface of the end plate 6 facing the transformer oil tank 1. The racks 9 respectively mesh with the gears 8 on the rotating shaft 13 of the fan blades 7.

[0031] The outer end of the flat oil cylinder 3 is provided with a pressure balance hole 10 communicating with its interior. A first spring 11 is also provided between the inner wall of the outer end of the flat oil cylinder 3 and the piston 4 inside it. When the transformer oil is heated and expands, the transformer oil pushes the piston 4 away from the transformer oil tank 1 and enters the flat oil cylinder 3 to increase the heat dissipation surface. The piston 4 compresses the first spring 11 and drives the rack 9 to move. The rack 9 drives the gear 8 to rotate. The gear 8 drives the fan blade 7 to rotate and dissipate heat. When the transformer oil cools down and contracts, the first spring 11 drives the piston 4 to push the liquid transformer oil in the flat oil cylinder 3 back to the transformer oil tank 1.

[0032] Specifically, in the above embodiments, the outer end of the component refers to the end of the component that is away from the transformer housing.

[0033] Specifically, the thickness of the flat oil cylinder 3 is the same as that of the heat sink 2, and the piston 4 is adapted to the internal cross section of the flat oil cylinder 3 to achieve a sliding seal.

[0034] The working process of the above embodiment is as follows: When the transformer oil in the transformer oil tank 1 is heated and expands, the transformer oil pushes the piston 4 away from the transformer oil tank 1. At the same time, the transformer oil enters the flat oil cylinder 3 to increase the heat dissipation surface. The piston 4 compresses the first spring 11 and drives the rack 9 to move away from the transformer oil tank 1. The rack 9 drives the gear 8 to rotate. The gear 8 drives the fan blade 7 to rotate to dissipate heat. When the transformer oil cools down and contracts, the first spring 11 drives the piston 4 to push the liquid transformer oil in the flat oil cylinder 3 back to the transformer oil tank 1.

[0035] As can be seen from the above working process, the photovoltaic power generation silicon steel core oil-immersed transformer can convert the thermal expansion energy of the transformer oil into the kinetic energy of the fan blades 7, helping the heat sink 2 to improve the heat dissipation effect. At the same time, the sliding characteristics of the piston 4 in the flat oil cylinder 3 allow the space for transformer oil in the transformer tank 1 to change with pressure, reducing the pressure load on the transformer tank 1 under high oil temperature conditions and improving its anti-expansion ability. Furthermore, the transformer oil entering the flat oil cylinder 3 also increases the heat dissipation area, further improving the heat dissipation effect. Therefore, the structural improvement of the transformer tank 1 comprehensively enhances the short-circuit resistance of the photovoltaic power generation silicon steel core oil-immersed transformer, achieving multiple benefits.

[0036] In another embodiment, a bearing 12 is provided on the outer side of the heat sink 2, and the rotating shaft 13 of the fan blade 7 is fixedly connected to the central hole of the bearing 12. The fan blade 7 includes:

[0037] The annular part 14 has a first blind hole radially opened on its inner wall. A second spring 15 is provided in the first blind hole. A cylindrical pin 16 is connected to the front end of the second spring 15. A second blind hole is opened on the rotating shaft 13 of the fan blade 7 opposite to the first blind hole. The front end of the cylindrical pin 16 is inserted into the second blind hole.

[0038] A plurality of blades 17 are evenly spaced on the circumferential surface of the annular portion 14, and a counterweight is provided at the end of each blade 17.

[0039] When the gear 8 drives the fan blade 7 to rotate at a certain speed, and the centrifugal force of the cylindrical pin 16 is greater than the sum of the elastic force of the second spring 15 and its own weight, the front end of the cylindrical pin 16 will retract from the second blind hole to the first blind hole. Under the inertia of the counterweight, the several blades 17 will drive the annular part 14 to rotate around the shaft 13 of the fan blade 7.

[0040] The working process of the above embodiment is as follows: When the transformer oil in the transformer oil tank 1 is heated and expands, the transformer oil pushes the piston 4 away from the transformer oil tank 1. At the same time, the transformer oil enters the flat oil cylinder 3 to increase the heat dissipation surface. The piston 4 compresses the first spring 11 and drives the rack 9 to move away from the transformer oil tank 1. The rack 9 drives the gear 8 to rotate. The gear 8 drives the rotating shaft 13 of the fan blade 7 to rotate. Since the second spring 15 initially presses against the cylindrical pin 16, connecting the rotating shaft 13 of the fan blade 7 and the annular part 14, the rotating shaft 13 of the fan blade 7 and the annular part connected to it... The ring portion 14 and the blades 17 on the ring portion 14 rotate simultaneously. When the rotation speed of the ring portion 14 reaches a certain speed, the centrifugal force of the cylindrical pin 16 is greater than the sum of the elastic force of the second spring 15 and its own weight, causing the front end of the cylindrical pin 16 to retract from the second blind hole to the first blind hole. Under the inertia of the counterweight, the blades 17 continue to drive the ring portion 14 to rotate around the shaft 13 of the fan blade 7. When the elastic force on the first spring 11 is balanced with the pressure on the piston 4, the rack 9 stops moving, and the gear 8 meshing with the rack 9 also stops rotating, so the shaft 13 of the fan blade 7 also stops rotating. As the rotation speed of the ring portion 14 gradually decreases, the centrifugal force on the cylindrical pin 16 gradually decreases. The elastic force applied to the cylindrical pin 16 by the second spring 15 forces the cylindrical pin 16 to press against the surface of the shaft 13 of the fan blade 7. When the ring portion 14 rotates, the cylindrical pin 16 will penetrate into the second blind hole, thereby reconnecting the ring portion 14 and the shaft 13 of the fan blade 7.

[0041] As can be seen from the above working process, the structural improvement of the fan blade 7 allows the annular part 14 and several blades 17 to continue rotating for a period of time after the rotating shaft 13 stops rotating, effectively extending the time for enhanced heat dissipation.

[0042] Furthermore, a first annular stop 18 is provided on the rotating shaft 13 of the fan blade 7 to abut against the rear end of the annular portion 14, and a second stop is threadedly connected to the front end of the rotating shaft 13 to abut against the front end of the annular portion 14.

[0043] The first annular stop 18 and the second annular stop 19 can limit the annular portion 14 so that the second blind hole is located on the annular path of the cylindrical pin 16. The second annular stop 19 is threadedly connected to the rotating shaft 13, so the second annular stop 19 can be removed from the rotating shaft 13, which facilitates the disassembly and maintenance of the annular portion 14.

[0044] Furthermore, the surfaces of the rotating shaft 13, the first annular stop 18, and the second stop that contact the annular portion 14 are all coated with a wear-resistant and friction-reducing coating. The wear-resistant and friction-reducing coating can reduce the frictional resistance when the annular portion 14 rotates, thereby extending the heat dissipation time of the fan blade 7.

[0045] In another embodiment, the inner wall of the transformer tank 1 is provided with a grid-like reinforcing rib 20. The grid-like reinforcing rib 20 can increase the structural strength of the tank wall panel, making it more resistant to expansion impact.

[0046] Furthermore, angle steel 21 is provided at the included angle between two adjacent walls inside the transformer tank 1 to strengthen the connection, improve the structural integrity and rigidity of the tank, and reduce the probability of the tank deforming due to heat.

[0047] Furthermore, the top edge of the transformer oil tank 1 is provided with a flange, and the tank cover is bolted to the flange.

[0048] In another embodiment, a support rod is provided on the outer top surface of the tank cover, and a heat insulation plate is provided on the support rod to cover the transformer. The heat insulation plate can shield the transformer from light and rain, reducing the impact of sunlight heating on the transformer.

[0049] In another embodiment, the bottom of the transformer tank 1 is fixed to a liftable platform. The liftable platform can be a hydraulic liftable platform or a screw liftable platform. The liftable platform can change the height of the transformer from the ground, preventing rainwater from soaking the transformer when there is excessive water accumulation on the ground.

[0050] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation, comprising: a transformer tank, a transformer core disposed within the transformer tank, and a tank cover disposed on the top of the transformer tank, wherein the tank cover is provided with a high-voltage terminal, a low-voltage terminal, a tap changer, an oil conservator, a gas relay, and an explosion-proof pipe, and the side wall of the transformer tank is provided with heat sinks, characterized in that, The heat sink is hollow inside and is connected to the inside of the transformer oil tank; The outer end of the heat sink is connected with several flat oil cylinders evenly spaced from top to bottom. The inner end of the flat oil cylinder is connected to the heat sink. A piston is slidably connected inside the flat oil cylinder. A connecting rod is vertically connected to the end face of the piston facing away from the transformer oil tank. The connecting rod passes out from the outer end of the flat oil cylinder. An end plate is provided on the outer side of the outer end of the flat oil cylinder. The connecting rods in the several flat oil cylinders are all connected to the end plate. The outer side of the heat sink is rotatably connected with several fan blades at even intervals from top to bottom. Gears are coaxially arranged on the rotating shaft of the fan blades. Several horizontally arranged racks are connected to the plate surface of the end plate facing the transformer oil tank. The racks mesh with the gears on the rotating shafts of the fan blades respectively. The outer end of the flat oil cylinder is provided with a pressure balance hole communicating with its interior. A first spring is also provided between the inner wall of the outer end of the flat oil cylinder and the piston inside. When the transformer oil is heated and expands, the transformer oil pushes the piston away from the transformer oil tank and enters the flat oil cylinder to increase the heat dissipation surface. The piston compresses the first spring and drives the rack to move. The rack drives the gear to rotate, and the gear drives the fan blade to rotate to dissipate heat. When the transformer oil cools down and contracts, the first spring drives the piston to push the liquid transformer oil in the flat oil cylinder back to the transformer oil tank.

2. The photovoltaic power generation short-circuit resistant silicon steel core oil-immersed transformer as described in claim 1, characterized in that, A bearing is provided on the outer surface of the heat sink, and the shaft of the fan blade is fixedly connected to the central hole of the bearing. The fan blade includes: The annular part has a first blind hole radially opened on its inner wall. A second spring is installed in the first blind hole. A cylindrical pin is connected to the front end of the second spring. A second blind hole is opened on the rotating shaft of the fan blade opposite to the first blind hole. The front end of the cylindrical pin is inserted into the second blind hole. Several blades are evenly spaced on the circumferential surface of the annular portion, and a counterweight is provided at the end of each blade. When the gear drives the fan blade to rotate at a certain speed, the centrifugal force of the cylindrical pin is greater than the sum of the elastic force of the second spring and its own weight, causing the front end of the cylindrical pin to retract from the second blind hole to the first blind hole. Under the inertia of the counterweight, several blades drive the annular part to rotate around the axis of the fan blade.

3. The photovoltaic power generation short-circuit resistant silicon steel core oil-immersed transformer as described in claim 2, characterized in that, The fan blade shaft is provided with a first annular stop block that abuts against the rear end of the annular portion, and the front end of the shaft is threadedly connected to a second stop block that abuts against the front end of the annular portion.

4. The photovoltaic power generation short-circuit resistant silicon steel core oil-immersed transformer as described in claim 2, characterized in that, The surfaces of the rotating shaft, the first annular stop, and the second stop that contact the annular portion are all coated with a wear-resistant and drag-reducing coating.

5. The photovoltaic power generation short-circuit resistant silicon steel core oil-immersed transformer as described in claim 1, characterized in that, The inner wall of the transformer tank is provided with a grid-like reinforcing rib.

6. The photovoltaic power generation short-circuit resistant silicon steel core oil-immersed transformer as described in claim 1, characterized in that, Angle steel is installed at the angle between two adjacent walls inside the transformer tank to strengthen the connection.

7. The short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation as described in claim 1, characterized in that, The transformer tank has a flanged section at the top edge, and the tank cover is bolted to the flanged section.

8. The short-circuit resistant silicon steel core oil-immersed transformer for photovoltaic power generation as described in claim 1, characterized in that, A support rod is provided on the outer top surface of the box cover, and a heat insulation plate is provided on the support rod to cover the transformer.

9. The photovoltaic power generation short-circuit resistant silicon steel core oil-immersed transformer as described in claim 1, characterized in that, The bottom of the transformer oil tank is fixed on a liftable platform.

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