A cottonseed-based natural ester insulating oil transformer

Abstract

The invention relates to the technical field of transformers, and discloses a cottonseed-based natural ester insulating oil transformer, comprising a three-dimensional wound iron core, a coil assembly, cottonseed-based natural ester insulating oil and an oil tank, wherein the three-dimensional wound iron core and the coil assembly are arranged inside the oil tank, and the inside of the oil tank is filled with cottonseed-based natural ester insulating oil; a block receives the pressure of the cottonseed-based natural ester insulating oil, and a movable shaft presses a buffer spring, thereby adjusting the height of the block, so that the reflux speed of the cottonseed-based natural ester insulating oil is adapted to the pressure of the cottonseed-based natural ester insulating oil, thereby effectively ensuring the internal pressure stability of the oil tank, and at the same time, the buffer spring applies pressure to the piston block, so that the internal air pressure of the outer sleeve changes, and the effect of monitoring the internal pressure of the oil tank is achieved by monitoring the air pressure of the outer sleeve, thereby effectively ensuring the overall safety of the device, and when high pressure is reached, the reflux speed of the cottonseed-based natural ester insulating oil can be increased to achieve the effect of pressure relief, thereby further ensuring the safety of the device.

Description

Technical Field

[0001] The invention relates to the technical field of transformers, in particular to a cottonseed-based natural ester insulating oil transformer. Background Art

[0002] Liquid-immersed transformers are widely used in power grids. The insulating oil in the transformer plays the role of insulation and heat dissipation. Mineral insulating oil is widely used in power transformers because of its excellent electrical properties and low price. However, the flash point of mineral insulating oil is low, which cannot meet the requirements of high fire resistance of electrical equipment. It also has poor biodegradability. Once it leaks, it will cause serious damage to water and soil resources. At the same time, mineral insulating oil cannot be regenerated, and its future use and development are severely restricted. Therefore, it is of great significance to develop a natural ester insulating oil transformer with high flash point, easy degradation, renewability and environmental friendliness.

[0003] Patent No. CN111640560B discloses a natural ester insulating oil distribution transformer to solve the problem of unsatisfactory heat dissipation effect of transformers in the prior art, comprising a sealed shell covering the outside of the transformer body, and the interior of the sealed shell is filled with insulating oil soaking the transformer body, an oil conservator for filling the sealed shell with insulating oil is installed on the sealed shell, the oil conservator is provided with a pipeline connected to the sealed shell, and the oil conservator is provided with a transformer respirator for balancing the internal pressure of the oil conservator; multiple high-temperature resistant oil pipes installed on the top of the guide mechanism through the oil heat dissipation mechanism evenly inhale the hot insulating oil, and after heat dissipation, they are input into the guide mechanism and then sprayed toward the transformer heating coil again, so that the hydraulic oil distributed on the periphery of the transformer coil can be quickly replaced by the continuously sprayed low-temperature insulating oil, and the heat dissipation efficiency of the insulating oil is improved by increasing the flow speed of the insulating oil.

[0004] Although the above patent improves the heat dissipation efficiency of insulating oil by increasing the flow rate of insulating oil, the overall high-voltage coil and low-voltage coil inside the oil tank are immersed. In the actual working process, the junction area of ​​the high-voltage coil and the low-voltage coil often has a higher temperature due to the working characteristics. The above patent cannot carry out targeted treatment of this area, resulting in unsatisfactory heat dissipation effect. In addition, the above patent does not deal with the volume change of the oil circuit in the high-temperature environment during the flow of the entire oil circuit, which can easily cause the entire pipeline to collapse due to the thermal expansion and contraction of the insulating oil, resulting in the collapse of the entire oil circuit system. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a cottonseed-based natural ester insulating oil transformer, which has the advantages of good heat dissipation effect in the junction area of ​​the high-voltage coil and the low-voltage coil, and has the advantages of pressure detection of the entire insulating oil during the flow process, thereby avoiding excessive expansion of the insulating oil and causing damage to the pipeline.

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

[0007] A cottonseed-based natural ester insulating oil transformer comprises a three-dimensional wound iron core, a coil assembly, cottonseed-based natural ester insulating oil and an oil tank, wherein the three-dimensional wound iron core and the coil assembly are arranged inside the oil tank, the inside of the oil tank is filled with cottonseed-based natural ester insulating oil, the upper space of the oil tank is filled with dry nitrogen, the outside of the oil tank is fixedly connected with an oil pillow, and the oil pillow comprises an oil outlet mechanism and an oil return mechanism;

[0008] The oil pillow is connected to the oil tank and is used to stabilize the oil storage volume inside the oil tank;

[0009] The oil outlet mechanism comprises an oil outlet pipe, and the oil pillow pumps oil to the oil tank through the oil outlet pipe;

[0010] The oil return mechanism comprises an oil return pipe connected to the oil outlet of the oil tank, and a pressure stabilizing component for balancing the pressure inside the oil tank and the oil return pipe is arranged between the oil return pipe and the oil pillow.

[0011] Preferably, the cottonseed-based natural ester insulating oil is prepared from cottonseed as raw material through a series of advanced degreasing catalysis and other refining technologies, and has the advantages of high ignition point, excellent fire resistance, biodegradability, and no pollution.

[0012] Preferably, the oil tank is configured as a fully sealed hexagonal corrugated box body, a corrugated sheet is provided on the outside of the oil tank, the inner cavity size of the corrugated sheet is ribbed and enlarged, and is formed by fully automatic welding by an intelligent welding robot.

[0013] Preferably: the coil assembly includes a low-voltage coil and a high-voltage coil, and the low-voltage coil and the high-voltage coil are arranged to be concentrically sleeved inside and outside, and an oil channel is formed between the low-voltage coil and the high-voltage coil, the head end of the low-voltage coil is fixedly connected to the low-voltage lead, the head end of the high-voltage coil is fixedly connected to the high-voltage lead, and the branching terminal of the high-voltage coil is fixedly connected to the high-voltage branching lead. The conductors of the low-voltage coil and the high-voltage coil are wrapped with at least two layers of TUF-Flex dotted paper tape in a clockwise and counterclockwise cross-winding manner, and the interlayer insulation of the low-voltage coil adopts at least two layers of TUF-Flex dotted paper; the interlayer insulation of the high-voltage coil adopts at least two layers of DPE dotted paper.

[0014] Preferably, the wire insulation of the low-voltage coil is wrapped with 0.05mm*25mm TUF-Flex glue-dispensing paper in two layers in a clockwise and counterclockwise cross-winding manner.

[0015] Preferably, the wire insulation of the high-voltage coil is wrapped with three layers of TUF-Flex glue-dot paper with a specification of 0.05mm*25mm in a clockwise and counterclockwise cross-winding manner.

[0016] Preferably: the three-dimensional wound core can be assembled by continuously winding at least three silicon steel sheet strips, the three core columns are arranged in an equilateral triangle, the cross-sections of the three core columns are polygons with a circumscribed circle, there is no air gap in the magnetic circuit, the three-phase magnetic circuit is completely symmetrical and balanced and all are the shortest, and the three-phase circuit is completely symmetrical and balanced.

[0017] Preferably: the low-voltage coil and the high-voltage coil are each provided with three groups, the low-voltage coil includes an a-phase low-voltage coil, a b-phase low-voltage coil and a c-phase low-voltage coil, and the high-voltage coil includes an A-phase high-voltage coil, a B-phase high-voltage coil and a C-phase high-voltage coil;

[0018] The low-voltage lead wires include a-phase low-voltage lead wires, b-phase low-voltage lead wires and c-phase low-voltage lead wires which are electrically connected to the head ends of the a-phase low-voltage coil, the b-phase low-voltage coil and the c-phase low-voltage coil in sequence, the b-phase low-voltage coil is wound 1 / 3 turns less than the a-phase low-voltage coil and the c-phase low-voltage coil, and the radial positions of the head end and the tail end of the b-phase low-voltage coil differ by 120°;

[0019] The high-voltage leads include an A-phase high-voltage lead, a B-phase high-voltage lead and a C-phase high-voltage lead which are electrically connected to the head ends of the A-phase high-voltage coil, the B-phase high-voltage coil and the C-phase high-voltage coil in sequence;

[0020] The high-voltage tapping leads include an A-phase high-voltage tapping lead group, a B-phase high-voltage tapping lead group and a C-phase high-voltage tapping lead group which are electrically connected to the tapping outlets of the A-phase high-voltage coil, the B-phase high-voltage coil and the C-phase high-voltage coil in sequence.

[0021] Preferably: the end outlet and the head outlet of the low-voltage coil, and the head outlet and the tap outlet of the high-voltage coil are all arranged on the same side of the three-dimensional wound core;

[0022] An AC phase low voltage lead is laterally connected between the terminal of the A phase low voltage coil and the terminal of the C phase low voltage coil;

[0023] A b-ac phase low voltage lead is fixedly connected between the end of the b-phase low voltage coil and the ac phase low voltage lead, the b-phase low voltage lead is led out to the middle of the b-ac phase low voltage lead and bent upward 90°, and the b-phase low voltage lead and the b-ac phase low voltage lead form a low voltage "Y"-shaped connection of the transformer;

[0024] The b-ac phase low-voltage lead wire leads outwardly to form a 0-phase low-voltage lead wire.

[0025] Specific:

[0026] The a-phase low-voltage coil is fully wound, the head end and the tail end of the a-phase low-voltage coil are located at the same radial position, and the a-phase low-voltage lead wire is led upward from the head end of the c-phase low-voltage coil to form the low-voltage a-phase terminal of the transformer;

[0027] The c-phase low-voltage coil is wound with full turns, the head end and the tail end of the c-phase low-voltage coil are located at the same radial position, and the c-phase low-voltage lead wire is led upward from the head end of the c-phase low-voltage coil to form the low-voltage c-phase terminal of the transformer;

[0028] The 0-phase low-voltage lead is led out from the vicinity of the 60° horizontal bend of the b-ac phase low-voltage lead to the upper position of the head end of the a-phase low-voltage coil, and is bent 90° upward and led out to become the 0-phase terminal of the transformer.

[0029] Specifically: the b-phase low-voltage lead is led upward from the head end of the b-phase low-voltage coil to the top of the three-dimensional wound core, then bent 90° horizontally and led horizontally to the center of the b-phase iron core column of the three-dimensional wound core, rotated 60°, led horizontally to the middle of the ac-phase low-voltage lead, bent 90° upward and led out to form the low-voltage b-phase terminal of the transformer;

[0030] The b-ac phase low-voltage lead is led upward from the end of the b-phase low-voltage coil to the top of the three-dimensional wound iron core, then bent horizontally 90° and led horizontally to the center of the b-phase iron core column of the three-dimensional wound iron core, then bent horizontally 60°, led to the middle of the ac phase low-voltage lead in the vertical direction, bent downward 90°, and connected to the middle of the ac phase low-voltage lead to form a low-voltage "Y"-shaped connection of the transformer.

[0031] Specific:

[0032] The A-phase high-voltage coil is fully wound, the head end of the A-phase high-voltage coil and the tapping head are located in the same radial range, and the A-phase high-voltage lead wire is led upward from the head end of the A-phase high-voltage coil along an appropriate bending arc to be the high-voltage A-phase terminal of the transformer;

[0033] The A-phase high-voltage tapping lead group is led upward from the A-phase high-voltage coil tapping head to the top of the three-dimensional wound iron core, then turned to the central triangle area of ​​the three-dimensional wound iron core and connected to the tap switch;

[0034] The B-phase high-voltage coil is wound with 1 / 3 less turns, the head end of the B-phase high-voltage coil and the tapping head are located in the same radial range, the head end of the B-phase high-voltage coil and the tapping lead head have a radial deviation of 120°, and the B-phase high-voltage lead is led upward from the head end of the B-phase high-voltage coil along an appropriate bending arc, which is the high-voltage B-phase terminal of the transformer;

[0035] The B-phase high-voltage tapping lead group is led upward from the B-phase high-voltage coil tapping head to the top of the three-dimensional wound iron core, then turned to the central triangle area of ​​the three-dimensional wound iron core and connected to the tap switch;

[0036] The C-phase high-voltage coil is fully wound, the head end of the C-phase high-voltage coil and the tapping head are located in the same radial range, and the C-phase high-voltage lead wire is led upward from the head end of the C-phase high-voltage coil along an appropriate bending arc to be the high-voltage C-phase terminal of the transformer;

[0037] The C-phase high-voltage tap lead group is led out from the C-phase high-voltage coil tapping head upward to the top of the three-dimensional wound iron core, then turned to the central triangle area of ​​the three-dimensional wound iron core, and connected to the tap switch.

[0038] Preferably: an oil pressure pump and a debubbler are arranged between the oil outlet pipes, and the oil return mechanism also includes a support bar and an inner oil pipe arranged inside the oil channel, the support bars are evenly arranged between the oil channels, the support bars are clamped on the outside of the inner oil pipe, and the inner oil pipe is connected between the oil outlet pipe and the oil return pipe.

[0039] Preferably, the support bar is made of insulating paperboard, and the oil channel is composed of the support bar and cable paper.

[0040] Preferably: the pressure stabilizing assembly includes an oil filter detachably connected to the oil return pipe, the inner wall of the neck of the oil filter is provided with evenly distributed oil flow grooves, the inner rotatable connection of the oil filter is provided with a movable shaft, the top of the movable shaft is fixedly connected with a block, the top of the block is fixedly connected with a paddle, the block is movably connected to the neck of the oil filter, and the block is adapted to the inner diameter of the neck of the oil filter, the outer bottom of the oil filter is fixedly connected with a connecting pipe, the end of the connecting pipe away from the oil filter is connected to the oil pillow, the output end of the oil pressure pump is extended outwardly and is provided with a gear set, the bottom of the oil filter is fixedly connected with an outer sleeve rod, the outside of the outer sleeve rod is fixedly connected with an electromagnetic valve for controlling the outflow of internal gas, the interior of the oil filter is detachably installed with a filter plate, the interior of the outer sleeve rod is provided with a buffer assembly, and the oil pressure pump drives the movable shaft to rotate via the gear set and the buffer assembly.

[0041] Preferably, the buffer assembly comprises an outer sleeve shaft located inside the outer sleeve rod, a piston block is movably connected inside the outer sleeve shaft, and a connecting hole for connecting to the outer sleeve rod is formed at the bottom of the outer sleeve shaft.

[0042] Preferably: the outer sleeve shaft is rotatably connected to the inside of the outer sleeve rod, the outer sleeve shaft is transmission-connected to the gear set, the oil pressure pump drives the outer sleeve shaft to rotate via the gear set, the top of the piston block is fixedly connected to a buffer spring, the movable shaft is limitedly slidably connected to the inside of the outer sleeve shaft, the movable shaft rotates synchronously with the outer sleeve shaft, and the movable shaft is fixedly connected to the top of the buffer spring.

[0043] Preferably: the outer sleeve shaft is fixedly connected to the inside of the outer sleeve rod, the top of the piston block is fixedly connected to a core shaft rod, the core shaft rod is plugged into the inside of the movable shaft, a double helical groove is provided inside the movable shaft, the top of the core shaft rod is fixedly connected to a movable pin block adapted to the double helical groove, the bottom of the piston block is fixedly connected to at least two groups of drive ropes, the bottom of the drive rope is fixedly connected to a fixing plate, the fixing plate is transmission-connected to a gear set, and the oil pressure pump drives the fixing plate to rotate via the gear set.

[0044] Compared with the prior art, one or more of the above technical solutions have the following beneficial effects:

[0045] 1. The cottonseed-based natural ester insulating oil transformer receives the pressure of the cottonseed-based natural ester insulating oil through a block, and the movable shaft presses the buffer spring to adjust the height of the block, so that the reflux rate of the cottonseed-based natural ester insulating oil is adapted to the pressure of the cottonseed-based natural ester insulating oil, thereby effectively ensuring the internal pressure stability of the oil tank, and further ensuring the stability of the transformer. At the same time, the buffer spring applies pressure to the piston block to change the internal air pressure of the outer rod. By monitoring the air pressure of the outer rod, the internal pressure of the oil tank is monitored, effectively ensuring the overall safety of the device, and when high pressure is reached, the reflux rate of the cottonseed-based natural ester insulating oil can be increased to achieve the effect of pressure relief, further ensuring the safety of the device.

[0046] 2. The cottonseed-based natural ester insulating oil transformer has an oil channel between the high-voltage coil and the low-voltage coil, and supports and inner oil pipes are arranged inside the oil channel. The flow performance of the cottonseed-based natural ester insulating oil is effectively improved for the area between the low-voltage coil and the high-voltage coil, the heat dissipation effect of the area is improved, and the hot spot temperature rise in the area is reduced.

[0047] 3. The cottonseed-based natural ester insulating oil transformer, the core shaft rod can drive the block to reciprocate up and down through the cooperation of the double spiral groove and the movable pin block. The up and down reciprocating motion of the block can effectively improve the efficiency of the cottonseed-based natural ester insulating oil passing through the filter, ensuring the flow stability of the overall cottonseed-based natural ester insulating oil.

[0048] 4. The cottonseed-based natural ester insulating oil transformer has three-phase magnetic circuit and three-phase circuit that are completely symmetrical and balanced, which effectively improves the power supply quality, greatly reduces operating loss and noise, has obvious energy-saving effect, saves raw materials, has high production efficiency, good impact resistance, strong short-circuit resistance, and long operating life cycle. At the same time, it has the advantages of high heat resistance, excellent fire resistance, biodegradability, and no pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0050] Figure 1 A schematic diagram of the structure of the present invention;

[0051] Figure 2 A top view of the present invention;

[0052] Figure 3 A schematic diagram of a low voltage lead wire of the present invention;

[0053] Figure 4 A schematic diagram of a high voltage lead wire of the present invention;

[0054] Figure 5 This is a schematic diagram of the oil pillow and voltage stabilizing assembly of the present invention;

[0055] Figure 6 It is a cross-sectional schematic diagram of a voltage stabilizing assembly of the present invention;

[0056] Figure 7 It is a schematic diagram of a voltage stabilizing component of the present invention;

[0057] Figure 8 It is a schematic diagram of the internal support bar and the internal oil pipe of the oil channel of the present invention;

[0058] Fig. 9 This is a schematic diagram of the inner oil pipe of the present invention;

[0059] Fig.10 A schematic diagram of the invented oil pressure pump;

[0060] Fig.11 This is a schematic diagram of the state in which the block of the present invention falls back to the bottom of the oiler;

[0061] Fig.12 This is a schematic diagram of the piston block of the present invention being connected via a core shaft rod and a movable shaft;

[0062] Fig.13 It is a schematic diagram of the double helical groove of the movable pin block and movable shaft of the core shaft rod of the present invention in a cross-sectional state.

[0063] In the figure: 1. Three-dimensional wound core; 2. Coil assembly; 3. Cottonseed-based natural ester insulating oil; 4. Oil tank; 5. Oil pillow;

[0064] 21. Low-voltage coil; 22. High-voltage coil; 23. Oil channel; 24. Low-voltage lead; 25. High-voltage lead; 26. High-voltage tap lead; 211. A-phase low-voltage coil; 212. B-phase low-voltage coil; 213. C-phase low-voltage coil; 221. A-phase high-voltage coil; 222. B-phase high-voltage coil; 223. C-phase high-voltage coil; 241. A-phase low-voltage lead; 242. B-phase low-voltage lead; 243. C-phase low-voltage lead; 244. AC-phase low-voltage lead; 245. B-AC-phase low-voltage lead; 246. 0-phase low-voltage lead; 251. A-phase high-voltage lead; 252. B-phase high-voltage lead; 253. C-phase high-voltage lead; 261. A-phase high-voltage tap lead group; 262. B-phase high-voltage tap lead group; 263. C-phase high-voltage tap lead group;

[0065] 51. Oil outlet mechanism; 52. Oil return mechanism; 53. Pressure stabilizing assembly; 54. Oil pressure pump; 55. Gear set; 511. Oil outlet pipe; 512. Debubbler; 521. Oil return pipe; 522. Stay; 523. Inner oil pipe; 524. Connecting pipe; 531. Oiler; 532. Oil trough; 533. Movable shaft; 534. Block; 535. Paddle; 536. Buffer assembly; 537. Outer sleeve rod; 538. Solenoid valve; 539. Filter; 5361. Outer sleeve shaft; 5362. Piston block; 5363. Buffer spring; 5364. Connecting hole; 5365. Mandrel rod; 5366. Drive rope; 5367. Fixed plate; 5331. Double helical groove; 53651. Movable pin block. DETAILED DESCRIPTION

[0066] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] Example 1: Please refer to Figure 1-Figure 5 A cottonseed-based natural ester insulating oil transformer comprises a three-dimensional wound core 1, a coil assembly 2, a cottonseed-based natural ester insulating oil 3 and an oil tank 4. The three-dimensional wound core 1 and the coil assembly 2 are arranged inside the oil tank 4, the interior of the oil tank 4 is filled with the cottonseed-based natural ester insulating oil 3, and the upper gap of the oil tank 4 is filled with dry nitrogen.

[0068] In an optional embodiment, the cottonseed-based natural ester insulating oil 3 is prepared from cottonseed as raw material through a series of advanced degreasing catalysis and other refining technologies. Compared with traditional mineral insulating oils, it has the advantages of high ignition point, excellent fire retardant properties, biodegradability, and no pollution.

[0069] In an optional embodiment, the oil tank 4 is configured as a fully sealed hexagonal corrugated box body, and a corrugated sheet is provided on the outside of the oil tank 4. The inner cavity size of the corrugated sheet is ribbed and enlarged, and is formed by fully automatic welding by an intelligent welding robot. The internal gap of the oil tank 4 is filled with dry nitrogen to effectively prevent the cottonseed-based natural ester insulating oil 3 from contacting the outside air and being affected by moisture; according to the flow characteristics of the cottonseed-based natural ester insulating oil 3, the inner cavity size of the corrugated sheet is reinforced, optimized and enlarged to improve the fluidity of the cottonseed-based natural ester insulating oil 3 and effectively reduce the temperature rise of the transformer.

[0070] refer to Figure 2 and Figure 3 In an optional embodiment, the coil assembly 2 includes a low-voltage coil 21 and a high-voltage coil 22, the low-voltage coil 21 and the high-voltage coil 22 are arranged to be concentrically sleeved inside and outside, an oil passage 23 is formed between the low-voltage coil 21 and the high-voltage coil 22, a low-voltage lead 24 is fixedly connected to the head end of the low-voltage coil 21, a high-voltage lead 25 is fixedly connected to the head end of the high-voltage coil 22, a high-voltage tapping lead 26 is fixedly connected to the tapping head of the high-voltage coil 22, and the conductors of the low-voltage coil 21 and the high-voltage coil 22 are wrapped with at least two layers of TUF-Flex dotted paper tape in a clockwise and counterclockwise cross-winding manner;

[0071] The interlayer insulation of the low-voltage coil 21 uses at least two layers of TUF-Flex dispensing paper, and the interlayer insulation of the high-voltage coil 22 uses at least two layers of DPE dispensing paper. The DPE dispensing paper is made of 100% pure natural wood fiber. The appropriate insulation paper thickness and number of TUF-Flex dispensing paper and DPE dispensing paper are selected according to the interlayer voltage and interlayer field strength.

[0072] Among them, the wire insulation of the low-voltage coil 21 uses 0.05mm*25mm specification TUF-Flex dispensing paper to wrap the wire in two layers in a clockwise and counterclockwise cross-winding manner. The first layer is wrapped in a clockwise direction and the second layer is wrapped in a counterclockwise direction.

[0073] The wire insulation of the high-voltage coil 22 is wrapped with three layers of 0.05mm*25mm TUF-Flex adhesive paper in a clockwise and counterclockwise cross-winding manner.

[0074] TUF-Flex dispensing paper has good compatibility with cottonseed-based natural ester insulating oil 3, and its temperature resistance level in cottonseed-based natural ester insulating oil 3 can reach 140°C; the low-voltage coil 21 and the high-voltage coil 22 are bonded into a whole through high-temperature curing, which effectively increases the insulation strength and mechanical strength. It has extremely high mechanical properties and can withstand the impact of various forces during winding and operation. It has thinner thickness and higher mechanical strength, which can effectively reduce the average flipping length and coil size of the coil winding, thereby reducing the use of other high-cost raw materials (such as copper wire, iron core, oil tank, transformer oil, etc.), improving the product quality of the transformer, and has the characteristics of high electrical performance, short drying time, fast wetting speed, high heat resistance, etc., which promotes the overall design optimization of the transformer, shortens the drying and wetting time, thereby saving production costs and improving the market competitiveness of the product.

[0075] Among them, the three-dimensional wound core 1 can be assembled by continuously winding at least three silicon steel sheet strips, the three core columns are arranged in an equilateral triangle, the cross-section of the three core columns is a polygon with a circumscribed circle, there is no air gap in the magnetic circuit, the three-phase magnetic circuit is completely symmetrical and balanced and all are the shortest, and the three-phase circuit is completely symmetrical and balanced.

[0076] refer to Figure 2-Figure 4 In an optional embodiment, the low-voltage coil 21 and the high-voltage coil 22 are each provided with three groups, which are respectively wound on the outside of the three core columns of the three-dimensional wound core 1, the low-voltage coil 21 includes an a-phase low-voltage coil 211, a b-phase low-voltage coil 212 and a c-phase low-voltage coil 213, and the high-voltage coil 22 includes an A-phase high-voltage coil 221, a B-phase high-voltage coil 222 and a C-phase high-voltage coil 223;

[0077] The low-voltage lead 24 includes an a-phase low-voltage lead 241, a b-phase low-voltage lead 242 and a c-phase low-voltage lead 243 which are electrically connected to the head ends of the a-phase low-voltage coil 211, the b-phase low-voltage coil 212 and the c-phase low-voltage coil 213 in sequence. The b-phase low-voltage coil 212 is wound 1 / 3 less turn than the a-phase low-voltage coil 211 and the c-phase low-voltage coil 213. The radial positions of the head end and the tail end of the b-phase low-voltage coil 212 differ by 120°, which is beneficial to the installation and processing of the leads, saves labor and improves efficiency. At the same time, it can offset the disadvantage of large DC resistance caused by the longer b-phase low-voltage lead 242 and the b-ac phase low-voltage lead 245, thereby ensuring the DC resistance balance rate of the low-voltage coil 21.

[0078] The high-voltage lead 25 includes an A-phase high-voltage lead 251, a B-phase high-voltage lead 252, and a C-phase high-voltage lead 253 which are electrically connected to the head ends of the A-phase high-voltage coil 221, the B-phase high-voltage coil 222, and the C-phase high-voltage coil 223 in sequence;

[0079] The high-voltage tap lead 26 includes an A-phase high-voltage tap lead group 261, a B-phase high-voltage tap lead group 262 and a C-phase high-voltage tap lead group 263 which are electrically connected to the tapping ends of the A-phase high-voltage coil 221, the B-phase high-voltage coil 222 and the C-phase high-voltage coil 223 in sequence.

[0080] In an optional embodiment, the end outlet and the head outlet of the low-voltage coil 21, and the head outlet and the tap outlet of the high-voltage coil 22 are all arranged on the same side of the three-dimensional wound core 1;

[0081] An ac phase low voltage lead wire 244 is laterally connected between the end of the a phase low voltage coil 211 and the end of the c phase low voltage coil 213;

[0082] A b-ac phase low voltage lead 245 is fixedly connected between the end of the b-phase low voltage coil 212 and the ac phase low voltage lead 244. The b-phase low voltage lead 242 is led out to the middle of the b-ac phase low voltage lead 245 and bent upward by 90°. The b-phase low voltage lead 242 and the b-ac phase low voltage lead 245 form a low voltage "Y"-shaped connection of the transformer.

[0083] The b-ac phase low voltage lead 245 is led outwardly to a 0 phase low voltage lead 246 .

[0084] Specific:

[0085] The a-phase low-voltage coil 211 is fully wound, the head end and the tail end of the a-phase low-voltage coil 211 are located at the same radial position, and the a-phase low-voltage lead 241 is led upward from the head end of the c-phase low-voltage coil 213 to form the low-voltage a-phase terminal of the transformer;

[0086] The c-phase low-voltage coil 213 is fully wound, the head end and the tail end of the c-phase low-voltage coil 213 are located at the same radial position, and the c-phase low-voltage lead 243 is led upward from the head end of the c-phase low-voltage coil 213 to form the low-voltage c-phase terminal of the transformer;

[0087] The 0-phase low-voltage lead 246 is led out from the b-ac phase low-voltage lead 245 near the 60° horizontal bend to the upper position of the head end of the a-phase low-voltage coil 211, and then bent upward 90° to be led out, becoming the 0-phase terminal of the transformer.

[0088] Specifically: the b-phase low-voltage lead 242 is led upward from the head end of the b-phase low-voltage coil 212 to the top of the three-dimensional wound core 1, then bent 90° horizontally and led horizontally to the center of the b-phase core column of the three-dimensional wound core 1, rotated 60°, and led horizontally to the middle of the ac-phase low-voltage lead 244, bent 90° upward and led out, which is the low-voltage b-phase terminal of the transformer;

[0089] The b-ac phase low-voltage lead 245 is led out from the end of the b-phase low-voltage coil 212 upward and reaches the top 1 of the three-dimensional wound iron core. It is then bent 90° horizontally and led horizontally to the center position of the b-phase iron core column of the three-dimensional wound iron core 1, and then bent 60° horizontally to the middle of the ac phase low-voltage lead 244 in the vertical direction, bent downward 90°, and connected to the middle of the ac phase low-voltage lead 244 to form a low-voltage "Y" shape connection of the transformer.

[0090] Specific:

[0091] The A-phase high-voltage coil 221 is fully wound, the head end of the A-phase high-voltage coil 221 and the tapping head are located in the same radial range, and the A-phase high-voltage lead 251 is led upward from the head end of the A-phase high-voltage coil 221 along an appropriate curved arc, which is the high-voltage A-phase terminal of the transformer;

[0092] The A-phase high-voltage tapping lead set 261 is led out from the tapping head of the A-phase high-voltage coil 221 to the top of the three-dimensional wound core 1, then turns to the central triangle area of ​​the three-dimensional wound core 1, and is connected to the tap switch;

[0093] Among them, the B-phase high-voltage coil 222 is wound with less than 1 / 3 turns, the head end of the B-phase high-voltage coil 222 and the tapping head are located in the same radial range, the head end of the B-phase high-voltage coil 222 and the tapping lead head have a radial deviation of 120°, and the B-phase high-voltage lead 252 is led upward from the head end of the B-phase high-voltage coil 222 along an appropriate bending arc, which is the high-voltage B-phase terminal of the transformer;

[0094] The B-phase high-voltage tapping lead wire group 262 is led out from the tapping head of the B-phase high-voltage coil 222 to the top of the three-dimensional wound core 1, and then turns to the central triangle area of ​​the three-dimensional wound core 1, and is connected to the tap switch;

[0095] The C-phase high-voltage coil 223 is fully wound, the head end of the C-phase high-voltage coil 223 and the tapping head are located in the same radial range, and the C-phase high-voltage lead 253 is led upward from the head end of the C-phase high-voltage coil 223 along an appropriate bending arc, which is the high-voltage C-phase terminal of the transformer;

[0096] The C-phase high-voltage tap lead set 263 is led out from the tapped end of the C-phase high-voltage coil 223 to the top of the three-dimensional wound core 1 and then turned to the central triangle area of ​​the three-dimensional wound core 1 to be connected to the tap switch.

[0097] Example 2: Reference Figure 1-Figure 11 A cottonseed-based natural ester insulating oil transformer comprises a three-dimensional wound core 1, a coil assembly 2, a cottonseed-based natural ester insulating oil 3 and an oil tank 4, wherein the three-dimensional wound core 1 and the coil assembly 2 are arranged inside the oil tank 4, the inside of the oil tank 4 is filled with the cottonseed-based natural ester insulating oil 3, and the upper space of the oil tank 4 is filled with dry nitrogen;

[0098] Further on the basis of Example 1:

[0099] The outside of the oil tank 4 is fixedly connected with an oil pillow 5, and the oil pillow 5 includes an oil outlet mechanism 51 and an oil return mechanism 52;

[0100] The oil pillow 5 is connected to the oil tank 4 and is used to stabilize the oil storage volume inside the oil tank 4;

[0101] The oil outlet mechanism 51 includes an oil outlet pipe 511, and the oil pillow 5 pumps oil to the oil tank 4 through the oil outlet pipe 511;

[0102] The oil return mechanism 52 includes an oil return pipe 521 connected to the oil outlet of the oil tank 4 , and a pressure stabilizing component 53 for balancing the pressure inside the oil tank 4 and the oil return pipe 521 is provided between the oil return pipe 521 and the oil pillow 5 .

[0103] The oil pillow 5 is used to balance the pressure inside the oil tank 4. When the internal temperature of the oil tank 4 increases, the cottonseed-based natural ester insulating oil 3 expands due to heat, and the internal pressure of the oil tank 4 increases. The oil pillow 5 recovers excess cottonseed-based natural ester insulating oil 3 through the oil return pipe 521. When the temperature drops, similarly, the cottonseed-based natural ester insulating oil 3 inside the oil pillow 5 flows to the inside of the oil tank 4 through the oil outlet pipe 511.

[0104] Among them, the voltage stabilizing component 53 is used to monitor the pipeline pressure of the return oil pipe 521. When the internal pressure of the oil tank 4 increases, the cottonseed-based natural ester insulating oil 3 inside the oil tank 4 flows to the oil pillow 5 through the return oil pipe 521. At the same time, the cottonseed-based natural ester insulating oil 3 passes through the voltage stabilizing component 53. The voltage stabilizing component 53 is used to monitor the pressure of the oil pipe and assist in pressure balance. When the pressure exceeds the safety threshold, the voltage stabilizing component 53 issues a safety warning and performs power-off processing.

[0105] refer to Figure 8 and Fig. 9 In an optional embodiment, a pressure oil pump 54 and a debubbler 512 are arranged between the oil outlet pipe 511, and the oil return mechanism 52 also includes a strut 522 and an inner oil pipe 523 arranged inside the oil channel 23. The strut 522 is evenly arranged between the oil channels 23, and the strut 522 is clamped on the outside of the inner oil pipe 523. The inner oil pipe 523 is connected between the oil outlet pipe 511 and the oil return pipe 521.

[0106] Among them, the support bar 522 is made of insulating cardboard, the oil channel 23 is composed of the support bar 522 and cable paper, the thickness of the support bar 522 is >3mm, the width is >6mm, and the gap is >20mm, which effectively improves the flow performance of the cottonseed-based natural ester insulating oil 3, improves the heat dissipation effect, and reduces the temperature rise of hot spots.

[0107] By adding an oil pressure pump 54 to the oil outlet pipe 511, the cottonseed-based natural ester insulating oil 3 can continue to flow between the oil tank 4 and the oil pillow 5. The outside of the oil tank 4 is provided with a heat dissipation mechanism for dissipating the cottonseed-based natural ester insulating oil 3, which belongs to the prior art and is therefore not shown in the figure. By flowing the cottonseed-based natural ester insulating oil 3, not only the insulation protection of the coil assembly 2 during operation is effectively guaranteed, but also the heat dissipation of the coil assembly 2 during operation is effectively performed, thereby effectively ensuring the safety and stability of the transformer during operation.

[0108] At the same time, by providing the oil passage 23, the heat dissipation effect of the area between the low-voltage coil 21 and the high-voltage coil 22 is further improved, and the temperature rise of the hot spot in the area is reduced;

[0109] At the same time, an inner oil pipe 523 is added, and both the oil outlet pipe 511 and the oil return pipe 521 are provided with tees, which are respectively used to directly connect with the oil tank 4, and the inner oil pipe 523 is connected through the tee, so that a part of the cottonseed-based natural ester insulating oil 3 flowing out of the oil outlet pipe 511 directly flows into the interior of the oil tank 4, and the other part flows into the inner oil pipe 523 through the tee. The return oil pipe 521 receives a part of the cottonseed-based natural ester insulating oil 3 returning from the oil tank 4, and at the same time receives the other part that directly flows into the return oil pipe 521 from the inner oil pipe 523.

[0110] By setting up the inner oil pipe 523, the inner oil pipe 523 is immersed in the flow mode inside the oil tank 4, and the cross-section of the liquid flow is reduced, thereby increasing the liquid flow rate, thereby ensuring that the flow rate of the cottonseed-based natural ester insulating oil 3 inside the inner oil pipe 523 is greater than the flow rate of the cottonseed-based natural ester insulating oil 3 outside, thereby further improving the heat dissipation effect between the low-voltage coil 21 and the high-voltage coil 22, and reducing the hot spot temperature rise in this area.

[0111] refer to Figure 6 and Figure 7In an optional embodiment, the voltage stabilizing assembly 53 includes an oiler 531 detachably connected to the oil return pipe 521, the inner wall of the neck of the oiler 531 is provided with evenly distributed oil grooves 532, the inner part of the oiler 531 is rotatably connected to a movable shaft 533, the top of the movable shaft 533 is fixedly connected to a block 534, the top of the block 534 is fixedly connected to a paddle 535, the block 534 is movably connected to the neck of the oiler 531, and the block 534 is adapted to the inner diameter of the neck of the oiler 531, and the outer bottom of the oiler 531 is fixedly connected to There is a connecting pipe 524, one end of the connecting pipe 524 away from the oiler 531 is connected to the oil pillow 5, the output end of the oil pressure pump 54 is extended outwardly and is provided with a gear set 55, the bottom of the oiler 531 is fixedly connected with an outer sleeve rod 537, the outside of the outer sleeve rod 537 is fixedly connected with an electromagnetic valve 538 for controlling the outflow of internal gas, the inside of the oiler 531 is detachably installed with a filter plate 539, the inside of the outer sleeve rod 537 is provided with a buffer assembly 536, and the oil pressure pump 54 drives the movable shaft 533 to rotate through the gear set 55 and the buffer assembly 536.

[0112] refer to Figure 7 and Fig.11 When the cottonseed-based natural ester insulating oil 3 flows into the oil pillow 5 through the oil return pipe 521 , the cottonseed-based natural ester insulating oil 3 first flows into the oil passer 531 .

[0113] At the same time, during the operation of the oil pressure pump 54, the oil pressure pump 54 drives the movable shaft 533 to rotate through the buffer component 536, and the movable shaft 533 drives the block 534 and the paddle 535 on its top to rotate. Under the action of the buffer component 536, the block 534 can move up and down according to the pressure of the cottonseed-based natural ester insulating oil 3. The cottonseed-based natural ester insulating oil 3 on the top of the block 534 flows into the top of the filter 539 through the oil groove 532 exposed on the top of the block 534, and after being filtered by the filter 539, it flows into the interior of the oil pillow 5 through the connecting pipe 524, completing the circulation of the entire oil circuit.

[0114] Among them, the speed of the cottonseed-based natural ester insulating oil 3 passing through the block 534 is determined by the length of the upper oil groove 532 exposed by the block 534, the length of the upper oil groove 532 exposed by the block 534 is positively correlated with the descending distance of the block 534, and the descending distance of the block 534 is determined by the input pressure of the cottonseed-based natural ester insulating oil 3. Therefore, the speed of the cottonseed-based natural ester insulating oil 3 passing through the block 534 is adapted to the pressure of the cottonseed-based natural ester insulating oil 3. At the same time, since the block 534 is in a continuous rotation state, the paddle 535 on the top of the block 534 is in a rotating state. The paddle 535 effectively increases the speed of the cottonseed-based natural ester insulating oil 3 entering the oil groove 532 through the rotating centrifugal force, which facilitates the cottonseed-based natural ester insulating oil 3 to flow stably into the oil pillow 5.

[0115] refer to Figure 7 In an optional embodiment, the buffer assembly 536 includes an outer sleeve shaft 5361 located inside the outer sleeve rod 537, the inner part of the outer sleeve shaft 5361 is movably connected with a piston block 5362, and the bottom of the outer sleeve shaft 5361 is provided with a connecting hole 5364 for connecting to the outer sleeve rod 537.

[0116] Among them, the outer sleeve shaft 5361 is rotatably connected to the inside of the outer sleeve rod 537, the outer sleeve shaft 5361 is transmission connected to the gear group 55, the oil pressure pump 54 drives the outer sleeve shaft 5361 to rotate through the gear group 55, the top of the piston block 5362 is fixedly connected with a buffer spring 5363, the movable shaft 533 is limitedly slidably connected to the inside of the outer sleeve shaft 5361, the movable shaft 533 rotates synchronously with the outer sleeve shaft 5361, and the movable shaft 533 is fixedly connected to the top of the buffer spring 5363.

[0117] Specifically, in the initial state, the outer sleeve rod 537 is filled with high-pressure nitrogen, and the outer sleeve rod 537 maintains pressure balance through the connecting hole 5364 and the inner part of the outer sleeve shaft 5361.

[0118] A limiting ring is arranged inside the outer sleeve shaft 5361, and the piston block 5362 is slidably connected to the bottom of the limiting ring. Under the action of high-pressure nitrogen inside the outer sleeve shaft 5361, the piston block 5362 is pressed against the bottom of the limiting ring. At the same time, the piston block 5362 supports the movable shaft 533 through the buffer spring 5363, and when the oil pressure pump 54 is working, the oil pressure pump 54 drives the outer sleeve shaft 5361 to rotate through the gear set 55, and the outer sleeve shaft 5361 drives the movable shaft 533 to rotate.

[0119] When the movable shaft 533 receives the pressure of the cottonseed-based natural ester insulating oil 3 through the blocking block 534 , the movable shaft 533 presses the buffer spring 5363 , and at the same time the buffer spring 5363 applies pressure to the piston block 5362 , so that the internal air pressure of the outer sleeve rod 537 increases.

[0120] A barometer is provided inside the outer sleeve 537, and the barometer is electrically connected to the electromagnetic valve 538. At the same time, the safety threshold of the electromagnetic valve 538 is converted by the maximum pressure value of the transformer oil tank 4, and the specific value is determined by the transformer specifications. When the barometer detects that the air pressure inside the outer sleeve 537 is greater than the safety threshold, the electromagnetic valve 538 opens the air nozzle and issues an information warning and controls the transformer to cut off power. Since the air pressure inside the outer sleeve 537 is reduced, the piston block 5362 can slide to the lowest end of the outer sleeve shaft 5361, and the neck of the oiler 531 is fully opened, so that the cottonseed-based natural ester insulating oil 3 can flow back at the maximum speed, thereby effectively reducing the internal pressure of the oil tank 4 and ensuring the internal safety of the oil tank 4.

[0121] Example 3: Reference Fig.12 and Fig.13On the basis of the second embodiment, the distinguishing feature is that during the rotation of the blocking block 534, the blocking block 534 is in an up and down reciprocating motion.

[0122] Specific:

[0123] The buffer assembly 536 includes an outer sleeve shaft 5361 located inside the outer sleeve rod 537 . The inner part of the outer sleeve shaft 5361 is movably connected with a piston block 5362 . The bottom of the outer sleeve shaft 5361 is provided with a connecting hole 5364 for connecting with the outer sleeve rod 537 .

[0124] In an optional embodiment, the outer sleeve shaft 5361 is fixedly connected to the interior of the outer sleeve rod 537, the top of the piston block 5362 is fixedly connected to the core shaft rod 5365, the core shaft rod 5365 is inserted into the interior of the movable shaft 533, the interior of the movable shaft 533 is provided with a double helical groove 5331, the top of the core shaft rod 5365 is fixedly connected to a movable pin block 53651 adapted to the double helical groove 5331, the bottom of the piston block 5362 is fixedly connected to at least two groups of drive ropes 5366, the bottom of the drive rope 5366 is fixedly connected to a fixed plate 5367, the fixed plate 5367 is transmission-connected to the gear group 55, and the oil pressure pump 54 drives the fixed plate 5367 to rotate through the gear group 55.

[0125] Specifically, in the initial state, the outer sleeve rod 537 is filled with high-pressure nitrogen, and the outer sleeve rod 537 maintains pressure balance through the connecting hole 5364 and the inner part of the outer sleeve shaft 5361.

[0126] A limiting ring is arranged inside the outer sleeve shaft 5361, and the piston block 5362 is slidably connected to the bottom of the limiting ring. Under the action of the high-pressure nitrogen inside the outer sleeve shaft 5361, the piston block 5362 is pressed against the bottom of the limiting ring. At the same time, the piston block 5362 supports the movable shaft 533 through the core shaft rod 5365, and the high-pressure gas at the bottom of the piston block 5362 is equivalent to a pneumatic spring.

[0127] When the oil pressure pump 54 is working, the oil pressure pump 54 drives the fixed plate 5367 to rotate through the gear set 55, the fixed plate 5367 drives the piston block 5362 to rotate through the driving rope 5366, and the piston block 5362 drives the movable shaft 533 to rotate through the core shaft rod 5365.

[0128] And because a double helical groove 5331 is provided inside the movable shaft 533, a movable pin block 53651 adapted to the double helical groove 5331 is fixedly connected to the top of the core shaft rod 5365. At the same time, since there is friction damping between the blade 535 and the cottonseed-based natural ester insulating oil 3, when the core shaft rod 5365 drives the movable shaft 533 to rotate, the core shaft rod 5365 can drive the block 534 to reciprocate up and down through the cooperation of the double helical groove 5331 and the movable pin block 53651. The up and down reciprocating motion of the block 534 can effectively improve the efficiency of the cottonseed-based natural ester insulating oil 3 passing through the filter plate 539, thereby ensuring the flow stability of the overall cottonseed-based natural ester insulating oil 3.

[0129] Similar to the second embodiment, the movable shaft 533 receives the pressure of the cottonseed-based natural ester insulating oil 3 through the blocking block 534 , and the movable shaft 533 applies pressure to the piston block 5362 through the core shaft rod 5365 , so that the internal air pressure of the outer sleeve rod 537 increases.

[0130] A barometer is provided inside the outer sleeve 537, and the barometer is electrically connected to the electromagnetic valve 538, and a safety threshold is set for the electromagnetic valve 538. When the barometer detects that the air pressure inside the outer sleeve 537 is greater than the safety threshold, the electromagnetic valve 538 opens the air nozzle and issues an information warning and controls the transformer to cut off power. As the air pressure inside the outer sleeve 537 is reduced, the piston block 5362 can slide to the lowest end of the outer sleeve shaft 5361, and the neck of the oiler 531 is fully opened, so that the cottonseed-based natural ester insulating oil 3 can flow back at the maximum speed, thereby effectively reducing the internal pressure of the oil tank 4 and ensuring the internal safety of the oil tank 4.

[0131] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cottonseed-based natural ester insulating oil transformer, comprising a three-dimensional wound iron core (1), a coil assembly (2), cottonseed-based natural ester insulating oil (3) and an oil tank (4), wherein the three-dimensional wound iron core (1) and the coil assembly (2) are arranged inside the oil tank (4), and the inside of the oil tank (4) is filled with cottonseed-based natural ester insulating oil (3), characterized in that: An oil pillow (5) is fixedly connected to the outside of the oil tank (4), and the oil pillow (5) comprises an oil outlet mechanism (51) and an oil return mechanism (52); The oil pillow (5) is connected to the oil tank (4) and is used to stabilize the oil storage volume inside the oil tank (4); The oil outlet mechanism (51) comprises an oil outlet pipe (511), and the oil pillow (5) pumps oil into the oil tank (4) through the oil outlet pipe (511); The oil return mechanism (52) comprises an oil return pipe (521) connected to the oil outlet of the oil tank (4); a pressure stabilizing component (53) for balancing the pressure inside the oil tank (4) and the oil return pipe (521) is provided between the oil return pipe (521) and the oil pillow (5); The coil assembly (2) comprises a low-voltage coil (21) and a high-voltage coil (22), wherein the low-voltage coil (21) and the high-voltage coil (22) are concentrically sleeved inside and outside, an oil passage (23) is formed between the low-voltage coil (21) and the high-voltage coil (22), a head end of the low-voltage coil (21) is fixedly connected to a low-voltage lead (24), a head end of the high-voltage coil (22) is fixedly connected to a high-voltage lead (25), a branching end of the high-voltage coil (22) is fixedly connected to a high-voltage branching lead (26), the conductors of the low-voltage coil (21) and the high-voltage coil (22) are both wrapped with at least two layers of TUF-Flex dotted paper tape in a clockwise and counterclockwise cross-winding manner, the interlayer insulation of the low-voltage coil (21) is at least two layers of TUF-Flex dotted paper; the interlayer insulation of the high-voltage coil (22) is at least two layers of DPE dotted paper; An oil pressure pump (54) and a debubbler (512) are arranged between the oil outlet pipes (511); the oil return mechanism (52) further comprises a stay (522) and an inner oil pipe (523) arranged inside the oil passage (23); the stays (522) are evenly arranged between the oil passages (23); the stays (522) are clamped on the outside of the inner oil pipe (523); and the inner oil pipe (523) is connected between the oil outlet pipe (511) and the oil return pipe (521); The pressure stabilizing component (53) comprises an oiler (531) detachably connected to the oil return pipe (521); the inner wall of the neck of the oiler (531) is provided with evenly distributed oil passage grooves (532); the inner part of the oiler (531) is rotatably connected to a movable shaft (533); the top of the movable shaft (533) is fixedly connected to a block (534); the top of the block (534) is fixedly connected to a blade (535); the block (534) is movably connected to the neck of the oiler (531); the block (534) is adapted to the inner diameter of the neck of the oiler (531); the outer bottom of the oiler (531) is fixedly connected to a connecting pipe (524); ), one end of the connecting pipe (524) away from the oiler (531) is in communication with the oil pillow (5); an output end of the oil pressure pump (54) is extended outwardly and is provided with a gear set (55); an outer sleeve rod (537) is fixedly connected to the bottom of the oiler (531); an electromagnetic valve (538) for controlling the outflow of internal gas is fixedly connected to the outside of the outer sleeve rod (537); a filter sheet (539) is detachably installed inside the oiler (531); a buffer assembly (536) is provided inside the outer sleeve rod (537); and the oil pressure pump (54) drives the movable shaft (533) to rotate via the gear set (55) and the buffer assembly (536); The buffer assembly (536) comprises an outer sleeve shaft (5361) located inside the outer sleeve rod (537), a piston block (5362) is movably connected inside the outer sleeve shaft (5361), and a connecting hole (5364) for connecting to the outer sleeve rod (537) is formed at the bottom of the outer sleeve shaft (5361); The outer sleeve shaft (5361) is rotatably connected to the inside of the outer sleeve rod (537); the outer sleeve shaft (5361) is transmission-connected to the gear set (55); the oil pressure pump (54) drives the outer sleeve shaft (5361) to rotate via the gear set (55); a buffer spring (5363) is fixedly connected to the top of the piston block (5362); the movable shaft (533) is limitedly slidably connected to the inside of the outer sleeve shaft (5361); the movable shaft (533) rotates synchronously with the outer sleeve shaft (5361); and the movable shaft (533) is fixedly connected to the top of the buffer spring (5363).

2. A cottonseed-based natural ester insulating oil transformer according to claim 1, characterized in that: The oil tank (4) is configured as a fully sealed hexagonal corrugated box body, and a corrugated sheet is provided on the outside of the oil tank (4), and the inner cavity size of the corrugated sheet is processed by rib pressing and enlargement.

3. The cottonseed-based natural ester insulating oil transformer according to claim 1, characterized in that: The low-voltage coil (21) and the high-voltage coil (22) are each provided in three groups, the low-voltage coil (21) comprising an a-phase low-voltage coil (211), a b-phase low-voltage coil (212) and a c-phase low-voltage coil (213), and the high-voltage coil (22) comprising an A-phase high-voltage coil (221), a B-phase high-voltage coil (222) and a C-phase high-voltage coil (223); The low-voltage lead (24) comprises an a-phase low-voltage lead (241), a b-phase low-voltage lead (242) and a c-phase low-voltage lead (243) which are electrically connected to the head ends of the a-phase low-voltage coil (211), the b-phase low-voltage coil (212) and the c-phase low-voltage coil (213) in sequence; the b-phase low-voltage coil (212) is wound 1 / 3 less turns than the a-phase low-voltage coil (211) and the c-phase low-voltage coil (213); and the radial positions of the head end and the tail end of the b-phase low-voltage coil (212) differ by 120°; The high-voltage lead (25) comprises an A-phase high-voltage lead (251), a B-phase high-voltage lead (252), and a C-phase high-voltage lead (253) which are electrically connected to the head ends of the A-phase high-voltage coil (221), the B-phase high-voltage coil (222), and the C-phase high-voltage coil (223) in sequence; The high-voltage tapping lead (26) comprises an A-phase high-voltage tapping lead group (261), a B-phase high-voltage tapping lead group (262), and a C-phase high-voltage tapping lead group (263) which are electrically connected to tapping outlets of the A-phase high-voltage coil (221), the B-phase high-voltage coil (222), and the C-phase high-voltage coil (223) in sequence.

4. A cottonseed-based natural ester insulating oil transformer according to claim 3, characterized in that: The end outlet and the head outlet of the low-voltage coil (21), and the head outlet and the tap outlet of the high-voltage coil (22) are all arranged on the same side of the three-dimensional wound core (1); An ac phase low voltage lead wire (244) is transversely connected between the end of the a phase low voltage coil (211) and the end of the c phase low voltage coil (213); A b-ac phase low voltage lead (245) is fixedly connected between the end of the b-phase low voltage coil (212) and the ac phase low voltage lead (244); the b-phase low voltage lead (242) is led out to the middle of the b-ac phase low voltage lead (245) and is bent upwards by 90°; the b-phase low voltage lead (242) and the b-ac phase low voltage lead (245) form a low voltage "Y"-shaped connection of the transformer; The b-ac phase low-voltage lead wire (245) leads outwardly to a 0-phase low-voltage lead wire (246).

5. The cottonseed-based natural ester insulating oil transformer according to claim 1, characterized in that: The outer sleeve shaft (5361) is fixedly connected to the interior of the outer sleeve rod (537); the top of the piston block (5362) is fixedly connected to a core shaft rod (5365); the core shaft rod (5365) is plugged into the interior of the movable shaft (533); a double helical groove (5331) is provided inside the movable shaft (533); the top of the core shaft rod (5365) is fixedly connected to a movable pin block (53651) adapted to the double helical groove (5331); the bottom of the piston block (5362) is fixedly connected to at least two groups of driving ropes (5366); the bottom of the driving rope (5366) is fixedly connected to a fixing plate (5367); the fixing plate (5367) is transmission-connected to the gear set (55); the oil pressure pump (54) drives the fixing plate (5367) to rotate via the gear set (55).

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