A dry-type transformer in a wind turbine cabin

Abstract

A dry-type transformer in a wind turbine cabin includes an iron core, and the outer periphery of the core column of the iron core is sequentially provided with a low-voltage coil, an insulating cylinder, and a high-voltage coil from the inside to the outside. The upper end of the low-voltage coil is provided with a tap and is respectively led out from the upper end of the low-voltage coil through an inner lead row, a middle lead row, and an outer lead row, and the inner lead row is connected to a low-voltage terminal; a gasket, a silicone rubber plate, a high-voltage coil, and a low-voltage coil end face adopt a mutually embedded structure, which can fix the coil in three dimensions of X, Y, and Z. The transformer coil does not shift or shake in a vibration environment, effectively reducing the vibration of the coil, reducing the transformer noise, and improving the reliability of the transformer operation.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to a dry-type transformer in a wind turbine cabin. Background Art

[0002] A transformer is a static electrical device that can convert electrical energy of one voltage and current into electrical energy of another voltage and current. After a wind turbine generates electrical energy, it must pass through a wind turbine transformer to increase the voltage of the generated electrical energy before it can be transmitted over long distances. Depending on the installation location, wind turbine transformers are generally divided into nacelle transformers, tower transformers, and tower-outside combined transformers.

[0003] The transformer in the wind turbine cabin is installed and used in the cabin, and the height from the ground varies from tens of meters to more than one hundred meters. The installation and transportation process is very difficult, and daily inspection and maintenance cannot be carried out during operation. If the transformer and its accessories fail, it is difficult to repair, which puts higher requirements on the quality, safety and reliability of the transformer. The main technical problems it faces are:

[0004] (1) Harsh operating environment. Areas with abundant wind resources are generally concentrated in coastal areas, northeastern China, and northwest China, and transformers operate outdoors. Therefore, the weather resistance of the equipment must be considered. Equipment in coastal areas should be protected from salt spray, mold, and damp heat; equipment in northeastern China and northwest China should be protected from the effects of low temperatures, severe cold, wind, and sand.

[0005] (2) Always in a low-frequency vibration environment. Due to the influence of the rotation of wind turbine blades and the operation of generators, transformers are always in a low-frequency vibration environment. Long-term vibration will cause some parts to fail due to the superposition of fatigue effects, which may damage the transformer. Therefore, the design of transformers and their accessories must fully consider the impact of the vibration environment. In addition, after installation, wind power dry-type transformers are extremely difficult and expensive to maintain, so it is necessary to fully consider the ease of installation and reliability of operation.

[0006] (3) Continuous load changes. The uncontrollable nature of wind power means that the transformer has to operate under a continuously changing load and is subject to frequent hot and cold cycles. Every day, the transformer can cycle from very low load to very high load multiple times under local wind power. This is a great test for the ability of the epoxy resin insulation system to withstand thermal shock.

[0007] In order to adapt to the harsh climate and environmental conditions when operating in the nacelle, the transformer is required to have strong corrosion resistance and vibration resistance. Due to the size limitations of the nacelle itself, there are strict requirements on the volume and weight of the transformer. Transformers installed in wind turbine nacelles have high requirements for transformer reliability. The insulation strength of the transformer, the ability to withstand high humidity and high salt environments, the ability to resist lightning strikes, and the ability to resist vibration are important technical requirements for such transformers.

[0008] Conventional dry-type transformers cannot meet the above requirements. Existing wind power transformers usually install the transformer at the bottom of the tower, connect the wind turbine via a low-voltage cable, and then increase the voltage to 35kV and transmit it to the main substation. This method has large line losses, low power generation efficiency, and high overall costs. In addition, the transformer installed at the bottom of the tower is easy to touch, has poor protection performance, and icicles on the blades fall off and easily damage the transformer, which has low reliability. Patent application CN213124111U discloses an anti-displacement insulating pad for a dry-type transformer and a dry-type transformer, comprising an insulating pad body that plays a supporting role and an insulating gasket that plays an anti-displacement role, and a plurality of umbrella skirts are arranged on the side walls of the insulating pad body; a plurality of insulating tube positioning grooves are arranged in the middle of the upper part of the insulating pad body, and the tops on both sides of the insulating tube positioning grooves are coil support surfaces, and insulating gaskets are placed on the coil support surfaces; a plurality of positioning holes B of arbitrary shapes are arranged on the lower surface of the insulating pad body, and a plurality of positioning holes A of arbitrary shapes are arranged on the coil support surface. This patent fully considers the operation of the transformer in a long-term vibration environment and effectively enhances the fixed anti-displacement effect, but lacks consideration of improving the operating reliability of the wind power dry-type transformer and maintaining maintenance-free operation during the life cycle of the transformer under comprehensive factors such as the insulation strength of the transformer, tolerance to high humidity, operation in a high-salinity environment, lightning strikes, and long-term vibration. Summary of the invention

[0009] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a dry-type transformer in a wind turbine cabin, the low-voltage terminal can adjust the low-voltage coil wiring position in X, Y, and Z according to the position of the low-voltage interface in the cabin, to ensure reliable connection with the cabin low voltage, and convenient operation; the transformer low-voltage coil leads to a 400V tap and is equipped with fuse protection, which can integrate the power transformer function to provide the required power for secondary equipment, save power transformer investment, save space in the cabin, and reduce the overall weight of the cabin; the electrical and insulation settings are small in size, light in weight, stable in electrical performance, good in weather resistance, strong in resistance to lightning strikes, can adapt to the environmental conditions of the wind turbine cabin, have strong vibration resistance, and are suitable for use in harsh operating environments such as long-term vibration. It can operate safely and reliably during its life cycle, and has the advantages of long operating life, stable operation, corrosion resistance, and safety and reliability.

[0010] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0011] A dry-type transformer in a wind turbine cabin comprises an iron core 1, a core column 34 of the iron core 1 is provided with a low-voltage coil 6, an insulating tube 10 and a high-voltage coil 5 in sequence from the inside to the outside, the upper end of the low-voltage coil 6 is provided with a tap and is led out from the upper end of the low-voltage coil 6 through an inner lead row 24, an intermediate lead row 25 and an outer lead row 26, wherein the outer lead row 26 is a neutral point for connecting the neutral point of the three-phase low-voltage coil 6; the intermediate lead row 25 outputs alternating current for use as a power supply for other electrical equipment in the cabin; the intermediate lead row 25 is led out after passing through a fuse 17, which can ensure that when a transformer fails, the fuse 17 melts after passing a large current, and the transformer is cut off. The output AC power is cut off to ensure the safety of other electrical equipment in the cabin; the inner lead row 24 is used to connect the wind turbine as the power input of the wind turbine, and the inner lead row 24 is connected to the low-voltage terminal 20, and the low-voltage terminal 20 is arranged in a stepped shape, and multiple rows of wiring holes 42 are arranged on each gradient, and the wiring holes 42 of different gradients are staggered with each other in the X-axis direction. According to the position of the low-voltage interface in the cabin, the wiring holes 42 on the corresponding gradient and the corresponding rows and columns are selected, and the low-voltage interface in the cabin is connected to the low-voltage coil 6 through wiring. The three dimensions of X, Y, and Z, namely the height, lateral, and longitudinal directions are adjusted to ensure that the low-voltage coil 6 is reliably connected to the cabin low voltage.

[0012] The iron core 1 adopts a three-phase three-column stacked core structure, and the surface of the iron core 1 is painted with resin composite insulating paint.

[0013] The intermediate lead row 25 outputs an alternating current of 400V.

[0014] The low-voltage coil 6 is wound with aluminum foil and poured with low-temperature resistant epoxy resin; the high-voltage coil 5 is wound with aluminum wire and poured with low-temperature resistant epoxy resin, and the resin layer completely encapsulates the internal conductor of the coil and is isolated from the outside; a panel 32 is provided on one side of the high-voltage coil 5, and wiring terminals 22 are provided at the upper and lower ends of the panel 32. The wiring terminals 22 of the three-phase high-voltage coil are cross-connected through a conductive rod 9, a tap terminal 23 is provided in the middle of the panel 32, and a creeping umbrella 33 is also provided on the panel, and a high-voltage terminal 19 is provided at the lower wiring terminal 22 of the high-voltage coil 5; all exposed terminals on the panel 32 of the high-voltage coil 5 need to be protected by insulating tape of corresponding insulation grade, and the tap terminals 23 are covered with silicone covers; the high-voltage terminal 19 is made of heterosexual copper plate, one end of the high-voltage terminal 19 is used to connect the transformer with the high-voltage cable in the cabin, and the other end is provided with a grounding ball 21 and a lightning arrester 11; the external heat shrink sleeve of the conductive rod 9 is insulated.

[0015] Upper clamps 2 are provided on both sides of the iron yoke at the top of the iron core 1, and lower clamps 3 are provided on both sides of the iron yoke 35 at the bottom of the iron core 1. An upper pad 8 is provided between the top of the low-voltage coil 6 and the high-voltage coil 5 and the bottom surface of the upper clamp 2, and a lower pad 16 is provided between the bottom end of the low-voltage coil 6 and the high-voltage coil 5 and the top surface of the lower clamp 3; the upper pad 8 and the lower pad 16 are cast by resin, a first silicone rubber plate 27 is provided between the bottom surface of the upper pad 8 and the top surface of the low-voltage coil 6, and a second silicone rubber plate 36 is provided between the bottom surface of the upper pad 8 and the top surface of the high-voltage coil 5; first limiting protrusions 29 are provided on both sides of the first silicone rubber plate 27, and second limiting protrusions 39 are provided on both sides of the second silicone rubber plate 36, and first concave countersunk holes 30 corresponding to the first limiting protrusions 29 are provided on the top surface of the low-voltage coil 6 and the bottom surface of the upper pad 8, and second concave countersunk holes 40 corresponding to the second limiting protrusions 39 are provided on the top surface of the high-voltage coil 5 and the bottom surface of the upper pad 8.

[0016] The upper clamp 2 is provided with hanging brackets 4 on both sides, a temperature control junction box 18 is provided on one side of the hanging bracket 4, a mounting base plate 14 is provided at the bottom of the lower clamp 3, and a fan 12 is provided on one side of the lower clamp 3; the power supply and protection wiring of the fan 12 are led to the fan junction box 13, and the fan junction box 13 is provided with plug-in terminal blocks to meet the IP67 protection standard.

[0017] The upper clamp 2 is provided with a temperature sensing cable 7, and the temperature measuring probe of the temperature sensing cable 7 adopts a PT100 platinum resistor; the temperature sensing cable 7 is led to a temperature control junction box 18 fixed on the upper clamp 2, and is connected to the control system in the cabin; the temperature control junction box 18 adopts a housing with protection grade IP65, and terminal plug-in wiring is adopted inside, and the cable enters and exits the temperature control junction box 18 through a sealed cable connector.

[0018] The outer periphery of the upper pad 8 and the lower pad 16 are both provided with side wings 28 for increasing the surface distance, and the top of the upper pad 8 and the bottom of the lower pad 16 are both provided with press pins 31; the contact part between the upper pad 8 and the high-voltage coil 5 and the low-voltage coil 6 is provided with a glass fiber grid and a glass ribbon 41, and the contact part between the lower pad 16 and the high-voltage coil 5 and the low-voltage coil 6 is provided with a glass fiber grid and a glass ribbon 41.

[0019] The connection structure between the top surface of the lower pad 16 and the bottom surface of the low-voltage coil 6 is the same as that between the bottom surface of the upper pad 8 and the top surface of the low-voltage coil 6, and the connection structure between the top surface of the lower pad 16 and the bottom surface of the high-voltage coil 5 is the same as that between the bottom surface of the upper pad 8 and the top surface of the high-voltage coil 5.

[0020] All electrical connection contact surfaces are coated with graphite conductive paste.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] (1) A tap is provided at the upper end of the low-voltage coil 6 and is led out from the upper end of the low-voltage coil 6 through the inner lead row 24, the middle lead row 25, and the outer lead row 26 respectively. The wiring holes 42 of different gradients on the low-voltage terminal 20 provided with the inner lead row 24 are staggered in the X-axis direction. According to the position of the low-voltage interface in the cabin, the wiring holes 42 on the corresponding gradient and the corresponding row or column can be selected, and the low-voltage interface in the cabin is connected to the low-voltage coil 6 through wiring. The three dimensions of X, Y, and Z, i.e., the three directions of height, lateral, and longitudinal, are adjusted to ensure that the low-voltage coil 6 is reliably connected to the cabin low voltage, and the operation is convenient.

[0023] (2) The electric energy generated by the wind turbine is generally 690V or higher, but many devices in the cabin require a 400V power supply. The prior art requires a power transformer in the cabin. An additional 400V tap is set on the low-voltage coil, which can provide a 400V power supply after being led out and protected by a fuse. The low-voltage coil can integrate the power transformer function to provide the required power for the secondary equipment. After adopting the above structure, the original power transformer can be eliminated, saving costs, increasing the operating space in the cabin, and reducing the overall weight of the cabin.

[0024] (3) Due to the continuous change in the load of the wind power transformer, the coil continues to expand due to heat and shrink due to cooling. The contact part between the coil end and the pad is prone to cracking due to the compression force. The transformer coil is cast with resin, and a glass fiber mesh and a glass ribbon 41 are added to the contact part between the pad and the coil. The glass fiber contained in the glass fiber mesh and the glass ribbon 41 can increase the toughness of the resin and improve the mechanical properties of the end structure. After adopting the above structure, the operating reliability of the transformer can be improved.

[0025] (4) The environment in the cabin is harsh, with strong winds and sand and humid air. After long-term operation, ordinary secondary terminal blocks are prone to poor contact and short circuit failures. The power cable of the fan 12 is led to the waterproof and dustproof fan junction box 13, and the signal cable of the fuse 17 and the temperature sensor cable 7 are led to the waterproof and dustproof temperature control junction box 18 respectively. The terminals in the fan junction box 13 and the temperature control junction box 18 are plug-in type. This structure is simple to operate and not prone to misoperation. It can prevent the terminals from malfunctioning in the humid, dirty and vibrating environment of the cabin, affecting the control system's acquisition of transformer signals, and provide better protection for the transformer.

[0026] (5) All electrical connection contact surfaces are coated with graphite conductive paste. The transformer operates in a vibration environment in the cabin. The electrical connection contact surfaces will separate momentarily under vibration, resulting in increased contact resistance. Long-term operation may burn the transformer. After the contact surface is coated with graphite conductive paste, the stickiness of the conductive paste can ensure good conductivity of the connection surface at the moment of separation. At the same time, the contact surface can be isolated from the air to prevent rust on the contact surface, which will increase the contact resistance and improve the reliability of the transformer.

[0027] (6) The surface of the core 1 is coated with resin composite insulating paint. The resin composite insulating paint can ensure that the core 1 is isolated from the air, thereby solving the problem of the core 1 rusting in harsh environments such as salt spray, mold, and damp heat. It can meet the C4H anti-corrosion grade, making the transformer operate safely and reliably.

[0028] (7) Through the pad, the silicone rubber plate, the end faces of the high-voltage coil 5 and the low-voltage coil 6 are embedded in each other, so that the coil can be fixed in three dimensions: X, Y, and Z. This prevents the transformer coil from shifting or shaking in a vibrating environment, and can effectively reduce the vibration of the coil, reduce the transformer noise, and improve the reliability of transformer operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a front view of the transformer of the present invention.

[0030] Figure 2 1 is a top view of the transformer of the present invention.

[0031] Figure 3 It is a side view of the transformer of the present invention.

[0032] Figure 4 It is a rear view of the transformer of the present invention.

[0033] Figure 5 It is a structural schematic diagram of the low-voltage terminal 20 of the present invention.

[0034] Figure 6 It is a schematic diagram of the connection between the low-voltage coil 6 and the inner lead row 24, the middle lead row 25, and the outer lead row 26 of the present invention.

[0035] Figure 7 It is a planar structural diagram of the low-voltage coil 6 of the present invention.

[0036] Figure 8 This is a diagram of the cushion block compression structure of the present invention, wherein: Figure 8 (a) is the disassembled state of the pad compression structure. Figure 8 (b) is the compression state of the cushion block compression structure.

[0037] Among them: 1. Iron core, 2. Upper clamp, 3. Lower clamp, 4. Lifting bracket, 5. High-voltage coil, 6. Low-voltage coil, 7. Temperature sensor cable, 8. Upper pad, 9. Conductive rod, 10. Insulation tube, 11. Lightning arrester, 12. Fan, 13. Fan junction box, 14. Mounting base, 15. Silicon rubber tube, 16. Lower pad, 17. Fuse, 18. Temperature control junction box, 19. High-voltage terminal, 20. Low-voltage terminal, 21. Grounding ball, 22. Wire terminal, 23, tap terminal, 24, inner lead row, 25, middle lead row, 26, outer lead row, 27, first silicone rubber sheet, 28, side wing, 29, first limiting protrusion, 30, first recessed countersunk hole, 31, press nail, 32, panel, 33, creeping umbrella, 34, core column, 35, iron yoke, 36, second silicone rubber sheet, 39, second limiting protrusion, 40, second recessed countersunk hole, 41, glass fiber mesh and glass ribbon; 42, wiring hole. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0039] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0040] See also Figures 1 to 6 A dry-type transformer in a wind turbine cabin comprises an iron core 1, and a low-voltage coil 6, an insulating tube 10 and a high-voltage coil 5 are arranged on the outer periphery of a core column 34 of the iron core 1 in sequence from the inside to the outside. A tap is arranged on the upper end of the low-voltage coil 6 and is led out from the upper end of the low-voltage coil 6 through an inner lead row 24, an intermediate lead row 25 and an outer lead row 26, respectively. The outer lead row 26 is a neutral point for connecting the neutral point of the three-phase low-voltage coil 6; the intermediate lead row 25 outputs alternating current for power supply of other electrical equipment in the cabin; the intermediate lead row 25 is led out after passing through a fuse 17, so that when a transformer fails, the fuse 17 melts after passing a large current, cuts off the output alternating current, and ensures The safety of other electrical equipment in the cabin; the inner lead row 24 is used to connect the wind turbine as the power input of the wind turbine. The inner lead row 24 is connected to the low-voltage terminal 20. The low-voltage terminal 20 is made of copper plate and is arranged in a stepped shape. Multiple rows of wiring holes 42 are arranged on each gradient, and on the low-voltage terminals 20 on both sides of the device, the wiring holes 42 of different gradients are staggered in the X-axis direction. According to the position of the low-voltage interface in the cabin, the wiring holes 42 on the corresponding gradient and the corresponding rows and columns are selected, and the low-voltage interface in the cabin is connected to the low-voltage coil 6 through wiring. It is adjusted in the three dimensions of X, Y, and Z, that is, the height, lateral, and longitudinal directions to ensure that the low-voltage coil 6 is reliably connected to the cabin low voltage.

[0041] The iron core 1 adopts a three-phase three-column stacked core structure, and the surface of the iron core 1 is painted with resin composite insulating paint.

[0042] The intermediate lead row 25 outputs an alternating current of 400V.

[0043] The low-voltage coil 6 is wound with aluminum foil and poured with low-temperature resistant epoxy resin; the high-voltage coil 5 is wound with aluminum wire and poured with low-temperature resistant epoxy resin, and the resin layer completely encapsulates the internal conductor of the coil and is isolated from the outside; a panel 32 is provided on one side of the high-voltage coil 5, and wiring terminals 22 are provided at the upper and lower ends of the panel 32. The wiring terminals 22 of the three-phase high-voltage coil are cross-connected through a conductive rod 9, a tap terminal 23 is provided in the middle of the panel 32, and a creeping umbrella 33 is also provided on the panel, and a high-voltage terminal 19 is provided at the lower wiring terminal 22 of the high-voltage coil 5; all exposed terminals on the panel 32 of the high-voltage coil 5 need to be protected by insulating tape of corresponding insulation grade, and the tap terminals 23 are covered with silicone covers; the high-voltage terminal 19 is made of heterosexual copper plate, one end of the high-voltage terminal 19 is used to connect the transformer with the high-voltage cable in the cabin, and the other end is provided with a grounding ball 21 and a lightning arrester 11; the external heat shrink sleeve of the conductive rod 9 is insulated, which can shorten the insulation distance to the ground.

[0044] See also Figure 1 , Figure 8 The core 1 is provided with a core column 34 in the middle, a silicone rubber ring 15 is provided between the core column 34 and the low-voltage coil 6, an upper clamp 2 is provided on both sides of the iron yoke 35 at the top of the core 1, and a lower clamp 3 is provided on both sides of the iron yoke 35 at the bottom of the core 1. An upper pad 8 is provided between the top of the low-voltage coil 6 and the high-voltage coil 5 and the bottom surface of the upper clamp 2, and a lower pad 16 is provided between the bottom end of the low-voltage coil 6 and the high-voltage coil 5 and the top surface of the lower clamp 3; the upper pad 8 and the lower pad 16 are cast by resin, and the bottom surface of the upper pad 8 is connected to the low-voltage coil 6 and the high-voltage coil 5. A first silicone rubber sheet 27 is provided between the top surfaces of the coils 6, and a second silicone rubber sheet 36 is provided between the bottom surface of the upper pad 8 and the top surface of the high-voltage coil 5; first limiting protrusions 29 are provided on both sides of the first silicone rubber sheet 27, and second limiting protrusions 39 are provided on both sides of the second silicone rubber sheet 36. First recessed countersunk holes 30 corresponding to the first limiting protrusions 29 are provided on the top surface of the low-voltage coil 6 and the bottom surface of the upper pad 8, and second recessed countersunk holes 40 corresponding to the second limiting protrusions 39 are provided on the top surface of the high-voltage coil 5 and the bottom surface of the upper pad 8.

[0045] The upper clamp 2 is provided with hanging brackets 4 on both sides, a temperature control junction box 18 is provided on one side of the hanging bracket 4, a mounting base plate 14 is provided at the bottom of the lower clamp 3, and a fan 12 is provided on one side of the lower clamp 3; the power supply and protection wiring of the fan 12 are led to the fan junction box 13, and the fan junction box 13 is provided with plug-in terminal blocks to meet the IP67 protection standard.

[0046] The upper clamp 2 is provided with a temperature sensing cable 7, and the temperature measuring probe of the temperature sensing cable 7 adopts a PT100 platinum resistor. According to the inherent properties of the PT100 platinum resistor, the PT100 platinum resistor can simulate the measurement of the temperature of the low-voltage coil 6; the temperature sensing cable 7 is led to a temperature control junction box 18 fixed on the upper clamp 2, and is connected to the control system in the cabin; the temperature control junction box 18 adopts a housing with a protection grade of IP65, and terminal plug-in wiring is adopted inside, and the cable enters and exits the temperature control junction box 18 through a sealed cable connector.

[0047] See also Figure 7 The upper pad 8 and the lower pad 16 are both provided with side wings 28 for increasing the surface distance on their outer peripheries, and the top of the upper pad 8 and the bottom of the lower pad 16 are both provided with press pins 31; a glass fiber grid and a glass ribbon 41 are provided at the contact portion between the upper pad 8 and the high-voltage coil 5 and the low-voltage coil 6, and a glass fiber grid and a glass ribbon 41 are provided at the contact portion between the lower pad 16 and the high-voltage coil 5 and the low-voltage coil 6.

[0048] The connection structure between the top surface of the lower pad 16 and the bottom surface of the low-voltage coil 6 is the same as that between the bottom surface of the upper pad 8 and the top surface of the low-voltage coil 6, and the connection structure between the top surface of the lower pad 16 and the bottom surface of the high-voltage coil 5 is the same as that between the bottom surface of the upper pad 8 and the top surface of the high-voltage coil 5.

[0049] All electrical connection contact surfaces are coated with graphite conductive paste.

[0050] The working principle of the present invention is:

[0051] Dry-type transformers need to adapt to the harsh operating environment of the wind turbine nacelle and are also limited by the size of the wind turbine nacelle itself. The transformers must have strong corrosion resistance and vibration resistance, be maintenance-free and extremely safe.

[0052] The present invention installs the dry-type transformer in an independent space at the rear of the cabin, shortens the distance between the transformer and the generator, reduces the required connecting cables, reduces line losses, and saves costs. The taps at the upper end of the low-voltage coil 6 are respectively led out through the inner lead row 24, the middle lead row 25, and the outer lead row 26, wherein the outer lead row 26 is used for the neutral point connection of the three-phase low-voltage coil 6; the middle lead row 25 outputs alternating current for power supply of other electrical equipment in the cabin; the middle lead row 25 is led out after passing through the fuse 17, which can ensure that when the transformer fails, the fuse 17 melts after passing a large current, cuts off the output alternating current, and ensures that other electrical equipment in the cabin is The safety of other electrical equipment; the inner lead row 24 is used to connect the wind turbine as the power input of the wind turbine, and the inner lead row 24 is also connected to the low-voltage terminal 20. The low-voltage terminal 20 is arranged in a stepped shape, and multiple rows of wiring holes 42 are arranged on each gradient, and on the low-voltage terminals 20 on both sides of the device, the wiring holes 42 of different gradients are staggered with each other in the X-axis direction. According to the position of the low-voltage interface in the cabin, the wiring holes 42 on the corresponding gradient and the corresponding rows and columns are selected, and the low-voltage interface in the cabin is connected to the low-voltage coil 6 through wiring. It is adjusted in three dimensions of X, Y, and Z, that is, in three directions of height, lateral, and longitudinal to ensure that the low-voltage coil 6 is reliably connected to the cabin low voltage, and the operation is convenient.

[0053] The surface of the iron core 1 is painted with resin composite insulating paint. The resin composite insulating paint adopts a special ratio, which can ensure that the iron core 1 is isolated from the air, solves the problem of the iron core 1 rusting in harsh environments such as salt spray, mold, humidity and heat, and can meet the C4H anti-corrosion level, so that the transformer can operate safely and reliably.

[0054] Due to the continuous change in the load of the wind power transformer, the coil continues to expand due to heat and shrink due to cooling. The contact part between the end of the transformer coil and the pad is prone to cracking due to the compression force. The transformer coil is cast with resin, and a glass fiber mesh and a glass ribbon 41 are added to the contact part between the pad and the transformer coil. The glass fiber contained in the glass fiber mesh and the glass ribbon 41 can increase the toughness of the resin and improve the mechanical properties of the end structure. After adopting the above structure, the operating reliability of the transformer can be improved.

[0055] The electric energy generated by wind turbines is generally 690V or higher, but many devices in the cabin require a 400V power supply. In the prior art, a power transformer is required in the cabin. An additional 400V tap is set on the low-voltage coil, which can provide a 400V power supply after being led out and protected by a fuse. The low-voltage coil can integrate the power transformer function to provide the required power for the secondary equipment. After adopting the above structure, the original power transformer can be eliminated, saving costs, increasing the operating space in the cabin, and reducing the overall weight of the cabin.

[0056] All electrical connection contact surfaces are coated with graphite conductive paste. The transformer operates in a vibration environment in the cabin. The electrical connection contact surface will separate instantly under vibration, resulting in increased contact resistance. Long-term operation may burn the transformer. After the contact surface is coated with graphite conductive paste, the stickiness of the conductive paste can ensure good conductivity of the connection surface at the moment of separation. At the same time, the contact surface can be isolated from the air to prevent rust on the contact surface, which will increase the contact resistance and improve the reliability of the transformer.

[0057] The mutually embedded structure between the pad, the silicone rubber plate, and the end faces of the transformer coil (high-voltage coil 5, low-voltage coil 6) can firmly fix the transformer coil in three dimensions: X, Y, and Z. This prevents the transformer coil from shifting or shaking in a vibrating environment, and can effectively reduce the vibration of the coil, reduce transformer noise, and improve the reliability of transformer operation.

Claims

1. A dry-type transformer in a wind turbine nacelle, comprising an iron core (1), a core column (34) of the iron core (1) being provided with a low-voltage coil (6), an insulating cylinder (10) and a high-voltage coil (5) in sequence from the inside to the outside on the outer periphery thereof, characterized in that: The upper end of the low-voltage coil (6) is provided with a tap and is led out from the upper end of the low-voltage coil (6) through an inner lead row (24), an intermediate lead row (25), and an outer lead row (26), wherein the outer lead row (26) is a neutral point and is used for connecting the neutral point of the three-phase low-voltage coil (6); the intermediate lead row (25) outputs alternating current and is used as a power supply for other electrical equipment in the cabin; the intermediate lead row (25) is led out after passing through a fuse (17) to ensure that when a transformer fails, the fuse (17) melts after passing a large current, cuts off the output alternating current, and ensures the safety of other electrical equipment in the cabin; the inner lead row (24) is used for connecting the neutral point of the three-phase low-voltage coil (6); the intermediate lead row (25 ... The row (24) is used to connect to the wind turbine as the wind turbine power input, and the inner lead row (24) is connected to the low-voltage terminal (20), and the low-voltage terminal (20) is in a stepped shape, and each gradient is provided with a plurality of rows of wiring holes (42), and the wiring holes (42) of different gradients are staggered in the X-axis direction. According to the position of the low-voltage interface in the cabin, the wiring holes (42) on the corresponding gradient and the corresponding row and column are selected, and the low-voltage interface in the cabin is connected to the low-voltage coil (6) through wiring, and the low-voltage coil (6) is adjusted in three dimensions of X, Y, and Z, that is, in three directions of height, lateral, and longitudinal, to ensure that the low-voltage coil (6) is reliably connected to the cabin low voltage; Upper clamps (2) are arranged on both sides of the iron yoke (35) at the top of the iron core (1), lower clamps (3) are arranged on both sides of the iron yoke (35) at the bottom of the iron core (1), an upper pad (8) is arranged between the top of the low-voltage coil (6) and the high-voltage coil (5) and the bottom surface of the upper clamp (2), and a lower pad (16) is arranged between the bottom of the low-voltage coil (6) and the high-voltage coil (5) and the top surface of the lower clamp (3); the upper pad (8) and the lower pad (16) are cast by resin, and a first silicone rubber plate (2) is arranged between the bottom surface of the upper pad (8) and the top surface of the low-voltage coil (6). 7), a second silicone rubber plate (36) is provided between the bottom surface of the upper pad (8) and the top surface of the high-voltage coil (5); first limiting protrusions (29) are provided on both sides of the first silicone rubber plate (27), second limiting protrusions (39) are provided on both sides of the second silicone rubber plate (36), first recessed countersunk holes (30) corresponding to the first limiting protrusions (29) are provided on the top surface of the low-voltage coil (6) and the bottom surface of the upper pad (8), and second recessed countersunk holes (40) corresponding to the second limiting protrusions (39) are provided on the top surface of the high-voltage coil (5) and the bottom surface of the upper pad (8).

2. A dry-type transformer in a wind turbine nacelle according to claim 1, characterized in that: The iron core (1) adopts a three-phase three-column stacked iron core structure, and the surface of the iron core (1) is painted with resin composite insulating paint.

3. The dry-type transformer in a wind turbine nacelle according to claim 1, characterized in that: The intermediate lead row (25) outputs an alternating current of 400V.

4. The dry-type transformer in a wind turbine nacelle according to claim 1, characterized in that: The low-voltage coil (6) is wound with aluminum foil and poured with low-temperature resistant epoxy resin; the high-voltage coil (5) is wound with aluminum wire and poured with low-temperature resistant epoxy resin, and the resin layer completely encapsulates the internal conductor of the coil and isolates it from the outside; a panel (32) is provided on one side of the high-voltage coil (5), and wiring terminals (22) are provided at the upper and lower ends of the panel (32), and the wiring terminals (22) of the three-phase high-voltage coils are cross-connected by conductive rods (9); a tap terminal (23) is provided in the middle of the panel (32), and a creepage current is also provided on the panel. The high-voltage coil (5) has an umbrella (33), and a high-voltage terminal (19) is provided at the lower terminal (22) of the high-voltage coil (5); all exposed terminals on the panel (32) of the high-voltage coil (5) are protected by insulating tape of corresponding insulation grade, and the tap terminals (23) are all covered with silicone covers; the high-voltage terminal (19) is made of heterosexual copper plate, one end of the high-voltage terminal (19) is used to connect the transformer with the high-voltage cable in the cabin, and the other end is provided with a grounding ball (21) and a lightning arrester (11); the conductive rod (9) is insulated by a heat shrink sleeve on the outside.

5. The dry-type transformer in a wind turbine nacelle according to claim 1, characterized in that: The upper clamp (2) is provided with hanging brackets (4) on both sides, a temperature control junction box (18) is provided on one side of the hanging bracket (4), a mounting base plate (14) is provided at the bottom of the lower clamp (3), and a fan (12) is provided on one side of the lower clamp (3); the power supply and protection wiring of the fan (12) are led to the fan junction box (13), and a plug-in terminal is provided in the fan junction box (13), meeting the IP67 protection standard.

6. A dry-type transformer in a wind turbine nacelle according to claim 1, characterized in that: The upper clamp (2) is provided with a temperature sensing cable (7), and the temperature measuring probe of the temperature sensing cable (7) adopts a PT100 platinum resistor; the temperature sensing cable (7) is led to a temperature control junction box (18) fixed on the upper clamp (2), and is connected to a control system in the cabin; the temperature control junction box (18) adopts a housing with a protection grade of IP65, and adopts terminal plug-in wiring inside, and the cable enters and exits the temperature control junction box (18) through a sealed cable connector.

7. The dry-type transformer in a wind turbine nacelle according to claim 1, characterized in that: The outer peripheries of the upper pad (8) and the lower pad (16) are both provided with side wings (28) for increasing the distance along the surface, and the top of the upper pad (8) and the bottom of the lower pad (16) are both provided with press pins (31); the contact parts of the upper pad (8) and the high-voltage coil (5) and the low-voltage coil (6) are provided with glass fiber meshes and glass ribbons (41), and the contact parts of the lower pad (16) and the high-voltage coil (5) and the low-voltage coil (6) are provided with glass fiber meshes and glass ribbons (41).

8. The dry-type transformer in a wind turbine nacelle according to claim 1, characterized in that: The connection structure between the top surface of the lower pad (16) and the bottom surface of the low-voltage coil (6) is the same as that between the bottom surface of the upper pad (8) and the top surface of the low-voltage coil (6), and the connection structure between the top surface of the lower pad (16) and the bottom surface of the high-voltage coil (5) is the same as that between the bottom surface of the upper pad (8) and the top surface of the high-voltage coil (5).

9. A dry-type transformer in a wind turbine nacelle according to any one of claims 1 to 8, characterized in that: All electrical connection contact surfaces are coated with graphite conductive paste.

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