An oil-immersed transformer with a small footprint

Abstract

The present invention discloses an oil-immersed transformer with a small footprint, comprising a housing, transformer windings, a transformer oil filter, an air filter, and cables. An insulating pad is fixed inside the housing, and transformer windings are fixedly mounted on the surface of the insulating pad. A group of low-voltage terminals and a group of high-voltage terminals extend from both sides of the transformer winding. The oil-immersed transformer with a small footprint is provided with a liquid pump, heat sink fins, and an extension frame. The liquid pump draws transformer oil from the upper side of the housing into the heat sink fins and flows back to the lower side of the housing, reducing the requirement for the heat sink fin area through forced cooling. The cables extend into the extension frame and are connected to the low-voltage and high-voltage terminals through connecting terminals. At this time, the extension frame acts as a traditional oil pillow, ensuring that the transformer oil always submerges the live components. This re-optimizes the component structure of the oil-immersed transformer, making the overall volume of the oil-immersed transformer smaller and more practical to use.

Description

Technical Field

[0001] The invention relates to the technical field of oil-immersed transformers, in particular to an oil-immersed transformer with a small occupied area. Background Art

[0002] Oil-immersed transformers are important equipment in building power supply and distribution. Their function is to reduce the high voltage in the power grid to the standard voltage used by users. Compared with dry-type transformers, oil-immersed transformers have stronger insulation performance and are more suitable for voltage regulation of ultra-high voltage power grids.

[0003] In actual use, existing oil-immersed transformers are equipped with components such as oil pillows and ceramic bushings that take up a lot of space on the outside, resulting in a bloated structure of the existing oil-immersed transformers. They require a large area for installation and have certain limitations in use. Existing oil-immersed transformers are usually not equipped with a transformer oil filtration structure, which causes impurities to accumulate in the oil-immersed transformer and adhere to the transformer windings during daily use, resulting in a decrease in the insulation effect inside the oil-immersed transformer and a shortened service life of the transformer oil. Existing oil-immersed transformers usually rely on ceramic bushings to separate each high-voltage incoming line, each low-voltage outgoing line, and the box. In this insulation method, the insulation between each high-voltage incoming line and each low-voltage outgoing line mainly relies on air, and air insulation is greatly affected by humidity and air pressure, which further reduces the insulation effect of the oil-immersed transformer. Existing oil-immersed transformers are usually equipped with a breather, but this breather has a simple structure and can only absorb moisture in the air. It is difficult to quickly replace and is not practical to use. To address the above problems, it is necessary to improve the existing equipment. Summary of the Invention

[0004] The object of the present invention is to provide an oil-immersed transformer with a small footprint, so as to solve the problems of the existing oil-immersed transformers mentioned in the above background technology, such as being bulky in structure, requiring a large area for installation, and having certain limitations in use. Existing oil-immersed transformers are usually not provided with a transformer oil filtering structure, so that impurities accumulate in the oil-immersed transformer and adhere to the transformer windings during daily use, resulting in a reduction in the insulation effect inside the oil-immersed transformer and a shortening of the service life of the transformer oil. The insulation between the high-voltage incoming line and each low-voltage outgoing line mainly relies on air, and air insulation is greatly affected by humidity and air pressure, resulting in a further reduction in the insulation effect of the oil-immersed transformer. Existing oil-immersed transformers are usually provided with a breather, but the breather has a simple structure, can only absorb moisture in the air, and is difficult to replace quickly.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: an oil-immersed transformer with a small footprint, comprising a box, a transformer winding, a transformer oil filter, an air filter, and a cable; an insulating pad is fixed inside the box, and the transformer winding is fixedly mounted on the surface of the insulating pad; a group of low-voltage terminals and a group of high-voltage terminals extend from both sides of the transformer winding; two groups of terminal fixing devices are fixedly mounted inside the box, and the two groups of terminal fixing devices are electrically connected to a group of high-voltage terminals and a group of low-voltage terminals, respectively; an extension frame is sealed and connected to the upper side of the box;

[0006] A ceramic top plate is sealed on the top of the extension frame, a liquid pump is fixedly installed on the outside of the extension frame, and one end of the liquid pump is connected to the oil suction pipe, while the other end of the liquid pump passes through the extension frame and is connected to the transformer oil filter device, the transformer oil filter device is connected to one end of the heat sink fin, and the other end of the heat sink fin is connected to the inside of the box, the heat sink fin is wrapped around the outside of the box, and an air filter device is provided on the end of the extension frame away from the transformer oil filter device.

[0007] Preferably, the terminal fixing device includes a ceramic beam, a support flange and a conductive core, the support flange is welded and fixed to the inner wall of the box, and the ceramic beam is fixedly installed on the top of the support flange, the conductive core is buried inside the ceramic beam, and the conductive core is electrically connected to the corresponding high-voltage terminal and the first terminal;

[0008] By adopting the above technical solution, the position of the conductive core on the ceramic beam is fixed, and then the high-voltage terminal and the low-voltage terminal are fixedly connected to the corresponding conductive core, which plays a role in fixing the position of the low-voltage terminal and the high-voltage terminal. At the same time, the external high-voltage incoming line and the low-voltage incoming line are fixedly connected to the corresponding conductive core, which plays a role in fixing the position of the high-voltage incoming line and the low-voltage incoming line. Through the above structure, the gap between each conductive component is ensured.

[0009] Preferably, the lower end of the oil-drawing pipe extends into the interior of the box, and the oil-drawing pipe is made of insulating ceramic;

[0010] By adopting the above technical solution, the liquid pump can easily extract the transformer oil in the box through the oil extraction pipe, while preventing the high-voltage current in the transformer winding from breaking through the insulation and leaking through the oil extraction pipe.

[0011] Preferably, the variable pressure oil filtering device includes a filter cartridge, a filter element and a bellows, one end of the filter cartridge is connected to the heat dissipation fin, and the other end of the filter cartridge is connected to one end of the bellows, while the other end of the bellows is connected to the liquid pump, and the filter element is installed inside the filter cartridge;

[0012] By adopting the above technical solution, after the transformer oil flows through the filter element, the filter element screens and separates impurities in the transformer oil, and the bellows between the filter cartridge and the liquid pump can be retracted and folded, and the bolts can be loosened to facilitate the removal of the filter cartridge while the liquid pump and the heat dissipation fins are fixed.

[0013] Preferably, the heat dissipation fins are spirally welded and fixed to the outside of the box, and the connection point between the heat dissipation fins and the box and the lower end of the oil extraction pipe are respectively located on both sides of the inside of the box;

[0014] By adopting the above technical solution, the transformer oil in the box body flows back to the box body through the oil suction pipe and the heat dissipation fins.

[0015] Preferably, the air filter device comprises a U-shaped tube, an opening, a sealing plug and a filter stick, wherein the U-shaped tube is welded and fixed to the surface of the extension frame, and an opening is opened on one side of the U-shaped tube, the sealing plug is fixedly connected to one end of the filter stick, and the filter stick is fitted inside the U-shaped tube, and the sealing plug is sealed with the opening;

[0016] By adopting the above technical solution, external air flows along the U-shaped tube into the top of the box. The air is filtered by two filter rods in turn during the flow, which greatly reduces the dust and water vapor in the air and delays the deterioration and aging of the transformer oil.

[0017] Preferably, the opening and the sealing plug are provided correspondingly, and there are two openings, two sealing plugs and two filter sticks, and the filter materials of the two filter sticks are different;

[0018] By adopting the above technical solution, it is easy to adjust the material of the filter rod according to the regional environment. At the same time, compared with the traditional single filter rod structure, it has a wider range of applications and better air filtering effect.

[0019] Preferably, a connecting terminal is provided at one end of the cable, and the connecting terminal is electrically connected to the corresponding conductive core;

[0020] By adopting the above technical solution, the cable is divided into a high-voltage incoming line and a low-voltage outgoing line, and the high-voltage incoming line and the low-voltage outgoing line are fixed by the fixed connection between the conductive core and the connection terminal. Subsequently, the various cables extending into the box are separated and insulated by transformer oil, which greatly improves the insulation effect.

[0021] Preferably, a connector is sealed and fixed on the outside of the cable, and the connector passes through the ceramic top plate and is fixedly connected to the cable;

[0022] By adopting the above technical solution, the ceramic top plate separates the cables by cooperating with the connector, limits the spacing between the cables, and further reduces the probability of high voltage breakdown between the cables.

[0023] Compared with the prior art, the present invention has the following advantages: the oil-immersed transformer occupies a small area,

[0024] (1) A terminal fixing device and a ceramic top plate are provided. The cables are fixed to the ceramic top plate through connectors. The ceramic top plate limits the spacing between the cables. The connecting terminals on the cables are fixedly connected to the terminal fixing device. The low-voltage terminals and high-voltage terminals on the transformer windings are fixed to the terminal fixing device. At this time, the connecting terminals, the lower ends of the cables, the high-voltage terminals, the low-voltage terminals and the terminal fixing device are all immersed in the transformer oil in the transformer. Through the above structure, the insulation effect of the oil-immersed transformer is greatly enhanced, and the influence of the external environment on the insulation effect of the transformer is eliminated.

[0025] (2) A liquid pump, a heat sink and an extension frame are provided. The liquid pump extracts the transformer oil from the upper side of the box into the heat sink and flows back to the lower side of the box. The forced cooling reduces the requirement for the heat sink area. The cable extends into the extension frame and is connected to the low-voltage terminal and the high-voltage terminal through the connecting terminal. At this time, the extension frame plays the role of a traditional oil pillow, so that the transformer oil always submerges the live parts. The component structure of the oil-immersed transformer is re-optimized, making the overall volume of the oil-immersed transformer smaller and more practical to use.

[0026] (3) A filter cartridge, a filter element and a bellows are provided. The liquid pump extracts the transformer oil in the box through the oil extraction pipe and pushes the hydraulic oil through the filter cartridge. When the transformer oil passes through the filter cartridge, the filter element in the filter cartridge filters the transformer oil. This step continuously cleans the transformer oil and prevents impurities in the transformer oil from adhering to the transformer winding. The bellows connected to the filter cartridge can be folded and contracted, making it easy to remove and replace the filter cartridge, thereby greatly extending the service life of the transformer oil in the oil-immersed transformer.

[0027] (4) A U-shaped tube and a filter rod are provided. Two filter rods are installed in the U-shaped tube. Different filter materials can be selected for the two filter rods according to the surrounding environment. The combination of the two filter materials greatly improves the filtering effect of the oil-immersed transformer on the external air. At the same time, the filter rod is installed inside the U-shaped tube through a sealing plug, which simplifies the maintenance steps and is more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the main cross-sectional structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the cross-sectional structure of the box body of the present invention;

[0030] Figure 3 It is a schematic diagram of the top view of the structure of the present invention;

[0031] Figure 4 This is a schematic diagram of a top-down cross-sectional structure of an extension frame of the present invention;

[0032] Figure 5 This is a schematic diagram of the main structure of the extension frame of the present invention;

[0033] Figure 6 This is a schematic diagram of the three-dimensional structure of the ceramic top plate of the present invention.

[0034] In the figure: 1. Box body, 2. Insulating pad, 3. Transformer winding, 4. Low-voltage terminal, 5. High-voltage terminal, 6. Terminal fixing device, 61. Ceramic beam, 62. Support flange, 63. Conductive core, 7. Extension frame, 8. Ceramic top plate, 9. Liquid pump, 10. Oil suction pipe, 11. Transformer oil filter device, 111. Filter cartridge, 112. Filter element, 113. Bellows, 14. Heat dissipation fin, 15. Air filter device, 151. U-shaped tube, 152. Opening, 153. Sealing plug, 154. Filter rod, 16. Cable, 17. Connecting terminal, 18. Connecting piece. DETAILED DESCRIPTION

[0035] 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 creative efforts are within the scope of protection of the present invention.

[0036] See also Figure 1-6 The present invention provides a technical solution: an oil-immersed transformer with a small footprint, such as Figure 1 and Figure 2 As shown, an insulating pad 2 is fixed inside the box 1, and a transformer winding 3 is fixedly installed on the surface of the insulating pad 2. A group of low-voltage terminals 4 and a group of high-voltage terminals 5 extend on both sides of the surface of the transformer winding 3. Two groups of terminal fixing devices 6 are fixedly installed inside the box 1, and the two groups of terminal fixing devices 6 are electrically connected to a group of high-voltage terminals 5 and a group of low-voltage terminals 4 respectively.

[0037] In a further embodiment, the terminal fixing device 6 includes a ceramic beam 61, a support flange 62 and a conductive core 63. The support flange 62 is welded and fixed to the inner wall of the box body 1, and the ceramic beam 61 is fixedly installed on the top of the support flange 62. The conductive core 63 is buried inside the ceramic beam 61, and the conductive core 63 is electrically connected to the corresponding high-voltage terminal 5 and the first terminal. The two ends of the ceramic beam 61 are fixedly installed on the support flange 62, so that the position of the conductive core 63 on the ceramic beam 61 is fixed, and the positions of the connecting terminal 17, the low-voltage terminal 4 and the high-voltage terminal 5 fixedly connected to the conductive core 63 are also fixed.

[0038] like Figure 1 As shown, an extension frame 7 is sealed and connected to the upper side of the box body 1 .

[0039] like Figure 1 、 Figure 3 and Figure 6 As shown, a ceramic top plate 8 is sealed on the top of the extension frame 7, and a liquid pump 9 is fixedly installed on the outside of the extension frame 7. One end of the liquid pump 9 is connected to the oil suction pipe 10, and the other end of the liquid pump 9 passes through the extension frame 7 and is connected to the transformer oil filter device 11.

[0040] In a further embodiment, the lower end of the oil suction pipe 10 extends into the interior of the box 1, and the material of the oil suction pipe 10 is insulating ceramic. The lower end of the oil suction pipe 10 is located on the upper side of the box 1, and the liquid pump 9 extracts the transformer oil with a higher temperature on the upper side of the box 1 through the oil suction pipe 10.

[0041] like Figure 4 As shown, the transformer oil filtering device 11 includes a filter cartridge 111, a filter element 112 and a bellows 113. One end of the filter cartridge 111 is connected to the heat dissipation fin 14, and the other end of the filter cartridge 111 is connected to one end of the bellows 113. At the same time, the other end of the bellows 113 is connected to the liquid pump 9. The filter element 112 is installed inside the filter cartridge 111, and the bellows 113 can be contracted and folded, which is convenient for removing the filter cartridge 111 when the heat dissipation fin 14 and the liquid pump 9 are in a fixed state.

[0042] like Figure 1 As shown, the transformer oil filter device 11 is connected to one end of the heat dissipation fin 14 , and the other end of the heat dissipation fin 14 is connected to the interior of the box body 1 .

[0043] In a further embodiment, the heat dissipation fins 14 are spirally welded and fixed to the outside of the box body 1, and the connection between the heat dissipation fins 14 and the box body 1 and the lower end of the oil suction pipe 10 are respectively located on both sides of the inside of the box body 1, so that the liquid pump 9 can pressurize the transformer oil and make the transformer oil pass through the spiral heat dissipation fins 14. The spiral heat dissipation fins 14 increase the heat dissipation area, which facilitates the discharge of heat in the transformer oil from the oil-immersed transformer.

[0044] like Figure 1 As shown, the heat dissipation fins 14 are wound around the outside of the box body 1 , and an air filter device 15 is provided at one end of the extension frame 7 away from the transformer oil filter device 11 .

[0045] In a further embodiment, the air filtering device 15 includes a U-shaped tube 151, an opening 152, a sealing plug 153 and a filter rod 154. The U-shaped tube 151 is welded and fixed to the surface of the extension frame 7, and an opening 152 is opened on one side of the U-shaped tube 151. The sealing plug 153 is fixedly connected to one end of the filter rod 154, and the filter rod 154 is fitly arranged inside the U-shaped tube 151. At the same time, the sealing plug 153 is sealed with the opening 152, so that when the outside air passes through the U-shaped tube 151 and enters the box body 1, it needs to pass through the two filter rods 154 in sequence, so that the two filter rods 154 can dry and remove dust from the air.

[0046] like Figure 4 and Figure 5 As shown, the opening 152 and the sealing plug 153 are correspondingly arranged, and there are two openings 152, sealing plugs 153 and filter rods 154, and the filter materials of the two filter rods 154 are different. The sealing plug 153 is rotated to remove the filter rod 154 on the sealing plug 153 so that the filter rod 154 leaves the U-shaped tube 151 from the opening 152, which simplifies the maintenance difficulty and facilitates the quick replacement of a new filter rod 154.

[0047] In a further embodiment, a connection terminal 17 is provided at one end of the cable 16 , and the connection terminal 17 is electrically connected to the corresponding conductive core 63 , so that the cable 16 is fixed to the conductive core 63 through the connection terminal 17 .

[0048] like Figure 6 As shown, a connector 18 is sealed and fixed on the outside of the cable 16, and the connector 18 passes through the ceramic top plate 8 and is fixedly connected to it. The cable 16 is fixed by the cooperation of the connector 18 and the ceramic top plate 8 and the spacing between each cable 16 is limited to avoid the gap between each cable 16 being too small, which may cause current breakdown accidents.

[0049] When in use, the conductive core 63 on the ceramic crossbeam 61 is fixedly connected to the low-voltage terminal 4, the high-voltage terminal 5 and the connecting terminal 17 respectively, playing the role of fixing the live components, and the transformer oil in the box body 1 submerges the above-mentioned live components, and the insulating pad 2 separates the transformer winding 3 and the box body 1. Through the above-mentioned components, the risk of the oil-immersed transformer being broken down by the high-voltage current is greatly reduced. The cable 16 supplies power to the oil-immersed transformer, and then the voltage is reduced through the transformer winding 3 and then transmitted to other power equipment through other cables 16. At this time, the transformer winding 3 heats up, and the transformer oil absorbs heat and rises to the upper side of the box body 1 under the action of thermal convection. The liquid pump 9 is started, and the liquid pump 9 extracts the transformer oil on the upper side of the box body 1 through the oil suction pipe 10. Then the transformer oil returns to the bottom of the box body 1 through the filter cartridge 111 and the heat dissipation fins 14 in turn. When the transformer oil passes through the filter element in the filter cartridge 111, the filter element filters impurities in the transformer oil and continuously collects impurities to avoid The heat dissipation fins 14 of the U-shaped heat dissipation fan 15 are used to dissipate heat from the heat sink 14, thereby greatly reducing the pollution of the external environment to the inside of the box 1. The filter element 112 in the filter element 111 is replaced, the sealing plug 153 is removed by rotating, and the filter rod 154 on the sealing plug 153 is replaced. The above structure facilitates the quick replacement of filter materials, reduces the difficulty of maintenance, and is more practical to use. This completes all operations. The content not described in detail in this manual belongs to the existing technology well known to professional and technical personnel in this field.

[0050] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the protection content of the present invention.

[0051] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oil-immersed transformer with a small footprint, comprising a housing (1), a transformer winding (3), a transformer oil filter (11), an air filter (15), and a cable (16), characterized in that: An insulating pad (2) is fixed inside the box (1), and a transformer winding (3) is fixedly installed on the surface of the insulating pad (2). A group of low-voltage terminals (4) and a group of high-voltage terminals (5) are respectively extended on both sides of the transformer winding (3). Two groups of terminal fixing devices (6) are fixedly installed inside the box (1), and the two groups of terminal fixing devices (6) are respectively electrically connected to a group of high-voltage terminals (5) and a group of low-voltage terminals (4). An extension frame (7) is sealed and connected to the upper side of the box (1). The terminal fixing device (6) includes a ceramic beam (61), a support flange (62) and a conductive core (63). The support flange (62) is welded and fixed to the inner wall of the box (1), and a ceramic beam (61) is fixedly installed on the top of the support flange (62). The conductive core (63) is buried inside the ceramic beam (61), and the conductive core (63) is electrically connected to the corresponding high-voltage terminal (5) and the first terminal. The top of the extension frame (7) is sealed with a ceramic top plate (8), and a liquid pump (9) is fixedly installed on the outside of the extension frame (7), and one end of the liquid pump (9) is connected to the oil extraction pipe (10), while the other end of the liquid pump (9) passes through the extension frame (7) and is connected to the transformer oil filter device (11), the transformer oil filter device (11) is connected to one end of the heat sink fin (14), and the other end of the heat sink fin (14) is connected to the inside of the box (1), the heat sink fin (14) is wound around the outside of the box (1), and an air filter device (15) is provided at the end of the extension frame (7) away from the transformer oil filter device (11).

2. The oil-immersed transformer with a small footprint according to claim 1, characterized in that: The lower end of the oil-drawing pipe (10) extends into the interior of the box (1), and the material of the oil-drawing pipe (10) is insulating ceramic.

3. The oil-immersed transformer with a small footprint according to claim 1, characterized in that: The variable pressure oil filtering device (11) comprises a filter cartridge (111), a filter element (112) and a bellows (113); one end of the filter cartridge (111) is connected to the heat dissipation fin (14), and the other end of the filter cartridge (111) is connected to one end of the bellows (113); and the other end of the bellows (113) is connected to the liquid pump (9); and the filter element (112) is installed inside the filter cartridge (111).

4. The oil-immersed transformer with a small footprint according to claim 1, characterized in that: The heat dissipation fins (14) are spirally welded and fixed to the outside of the box body (1), and the connection point between the heat dissipation fins (14) and the box body (1) and the lower end of the oil extraction pipe (10) are respectively located on both sides of the inside of the box body (1).

5. The oil-immersed transformer with a small footprint according to claim 1, characterized in that: The air filter device (15) comprises a U-shaped tube (151), an opening (152), a sealing plug (153) and a filter rod (154); the U-shaped tube (151) is welded and fixed to the surface of the extension frame (7); an opening (152) is provided on one side of the U-shaped tube (151); the sealing plug (153) is fixedly connected to one end of the filter rod (154); the filter rod (154) is fitted inside the U-shaped tube (151); and the sealing plug (153) is sealed and connected to the opening (152).

6. The oil-immersed transformer with a small footprint according to claim 5, characterized in that: The opening (152) and the sealing plug (153) are arranged correspondingly, and there are two openings (152), two sealing plugs (153) and two filter sticks (154), and the filter materials of the two filter sticks (154) are different.

7. The oil-immersed transformer with a small footprint according to claim 1, characterized in that: One end of the cable (16) is provided with a connection terminal (17), and the connection terminal (17) is electrically connected to the corresponding conductive core (63).

8. The oil-immersed transformer with a small footprint according to claim 7, characterized in that: A connecting piece (18) is sealed and fixed on the outside of the cable (16), and the connecting piece (18) passes through the ceramic top plate (8) and is fixedly connected thereto.

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