A three-dimensional wound core power transformer

Abstract

This invention provides a three-dimensional wound core power transformer, comprising a transformer housing, a high-voltage bushing, a low-voltage bushing, a three-dimensional wound core frame, and a winding assembly. A three-dimensional wound yoke is installed inside the housing, on which core insulation supports, grounding plates, and tie plates are mounted. The winding assembly includes a high-voltage winding and a low-voltage winding, with a magnetic reluctance joint buffer block between them, and is equipped with thermal expansion compensation connecting strips, damping and vibration reduction pads, a magnetic flux balancing ring, and a stress-reducing cylinder. The housing integrates an electric field gradient smoothing transition end ring disk, a discharge suppression microcavity cylinder, siphon-enhanced heat dissipation fins, a self-driven worm gear fan blade, a distributed optical fiber temperature measurement embedded slot, and a resonant frequency avoidance buffer cylinder. An electromagnetic decoupling isolation pad and a reinforced base are provided at the bottom. Through a closed magnetic circuit and dynamic thermal compensation, it overcomes the defects of traditional laminated transformers, such as discontinuous magnetic circuits, passive heat dissipation, concentrated electric fields, and poor mechanical stability, making it suitable for high-efficiency and high-reliability power distribution scenarios.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and more specifically, to a three-dimensional wound core power transformer. Background Technology

[0002] As a core device in power transmission and distribution systems, the structural design of power transformers directly affects energy efficiency, operational reliability, and environmental adaptability. Traditional power transformers mostly adopt a planar laminated core structure, which is made of a large number of silicon steel sheets stacked along a two-dimensional plane, with high-voltage and low-voltage windings concentrically mounted on the core column.

[0003] The transformer proposed in application number CN103151141A belongs to the field of transformer equipment technology. The technical solution of this invention includes a transformer housing, an internal coil, input wires, and output wires. Its characteristic feature is that the transformer housing is provided with an air inlet and an air outlet, and an exhaust fan is provided on the air outlet. Compared with the prior art, the transformer of this invention has better heat dissipation.

[0004] However, existing transformers have some shortcomings that require improvement. The laminated cores of existing transformers exhibit significant seams and magnetic circuit discontinuities at the corners of the yoke and core column, leading to asymmetrical magnetic flux paths and localized magnetic concentrations. This not only significantly increases no-load losses but also causes strong vibrations and noise due to magnetostriction. Secondly, existing transformers are prone to electric field concentration at the roots of high-voltage bushings, especially in polluted or humid environments, easily inducing partial discharges or even surface flashovers, lacking a structure to suppress discharge.

[0005] Existing transformers suffer from axial expansion and contraction of windings due to temperature rise during operation, lacking a compensation mechanism, which can easily lead to insulation compression failure or conductor deformation. Finally, existing transformer structures do not consider the risk of mechanical resonance, which may induce resonance under specific frequency excitation, accelerating structural fatigue. Therefore, a three-dimensional wound core power transformer is proposed. Summary of the Invention

[0006] The purpose of this invention is to address the problems raised in the existing background technology. To achieve the above-mentioned objective, this invention provides the following technical solution: a three-dimensional wound core power transformer, comprising a transformer housing, on which high-voltage bushings and low-voltage bushings are disposed, a three-dimensional wound core frame is disposed inside the transformer housing, a three-dimensional wound yoke is disposed inside the three-dimensional wound core frame, an accessory tap connection plate is disposed on the upper part of the three-dimensional wound core frame, a winding assembly is disposed inside the three-dimensional wound core frame, an electromagnetic decoupling isolation pad is disposed below the transformer housing, a discharge suppression microcavity is disposed on the side of the transformer housing, and an electric field gradient smooth transition end ring is disposed above the transformer housing.

[0007] As a preferred technical solution of the present invention, an iron core insulating support bar is provided at the interval of the three-dimensional coiled iron yoke, an iron core grounding plate is provided below the iron core insulating support bar, and an iron yoke pull plate is provided at the right end of the three-dimensional coiled iron yoke.

[0008] As a preferred embodiment of the present invention, the winding assembly includes a high-voltage winding and a low-voltage winding, a magnetic reluctance joint buffer block is provided between the high-voltage winding and the low-voltage winding, and a thermal expansion compensation connecting strip is provided on the right side of the high-voltage winding.

[0009] As a preferred technical solution of the present invention, a damping and vibration reduction pad is provided on the upper part of the thermal expansion compensation connecting strip, a magnetic flux balancing ring is provided below the high voltage winding, and a stress roller is provided below the magnetic flux balancing ring.

[0010] As a preferred embodiment of the present invention, the high-voltage bushing is provided with a high-voltage connector, and the low-voltage bushing is provided with a low-voltage lead.

[0011] As a preferred technical solution of the present invention, the side of the transformer housing is provided with siphon-enhanced heat dissipation fins, and a siphon worm gear fan blade is provided below the siphon-enhanced heat dissipation fins.

[0012] As a preferred embodiment of the present invention, the high-voltage bushing is connected to the transformer housing via a connecting pipe, and a lead wire tap changer is provided on the side of the connecting pipe.

[0013] As a preferred embodiment of the present invention, a base plate is provided below the electromagnetic decoupling isolation pad.

[0014] As a preferred embodiment of the present invention, a reinforcing beam is provided on the side of the base substrate, and a distributed optical fiber temperature measurement embedding groove is provided on the side of the transformer housing.

[0015] As a preferred technical solution of the present invention, the side of the siphon-enhanced heat dissipation fins is provided with a resonant frequency avoidance buffer cylinder.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention adopts a fully enclosed, seamless three-dimensional wound iron core structure, with a highly symmetrical magnetic circuit and a continuous and uniform magnetic flux path, which effectively suppresses hysteresis and eddy current losses; at the same time, the overall rigidity of the iron core is enhanced, which greatly reduces the vibration caused by magnetostriction, thereby achieving low-noise and energy-saving operation.

[0017] This invention features a smooth transition ring disk with electric field gradient and a discharge suppression microcavity in the high-voltage region to optimize the electric field distribution and avoid electric field concentration. Insulating support bars are set between the core layers and a reliable grounding plate is used to eliminate floating potential and significantly improve the stability and anti-discharge capability of the insulation system during long-term operation.

[0018] This invention utilizes siphon-enhanced heat dissipation fins and self-driven worm gear fan blades in synergy to form a passive enhanced convection cooling mechanism, efficiently dissipating internal heat without external power; combined with distributed fiber optic temperature sensing embedded slots, it achieves temperature status sensing throughout the entire life cycle, preventing local overheating.

[0019] The present invention combines a thermal expansion compensation connecting strip with a damping and vibration reduction pad, which can adapt to the axial displacement of the winding caused by temperature rise and absorb the electromagnetic vibration energy during operation; the magnetic flux equalization ring and the stress drum work together to balance the magnetic field distribution and buffer the short-circuit electrodynamic impact, ensuring the integrity of the winding structure.

[0020] The present invention features a yoke pull plate that firmly locks the end of the iron core to prevent loosening; a base plate and a reinforcing beam form a high-rigidity support system; and a resonant frequency avoidance buffer cylinder that avoids the system's inherent frequency through structural tuning, effectively suppressing mechanical resonance that may be caused during operation and extending the equipment's lifespan.

[0021] The invention features an electromagnetic decoupling isolation pad at the bottom to block stray currents from the ground grid and external electromagnetic interference, thereby improving operational reliability in complex electromagnetic environments. The overall sealed structure, combined with the layout of functional accessories, adapts to harsh operating conditions such as high humidity and high pollution. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure provided by the present invention; Figure 2 A schematic diagram of the three-dimensional coiled iron core frame structure provided by the present invention; Figure 3 This is a schematic diagram of a partial structure of the high-pressure bushing provided by the present invention; Figure 4 This is a schematic diagram of the magnetic reluctance joint buffer block structure provided by the present invention; Figure 5 This is a schematic diagram of a partial structure of the low-pressure bushing provided by the present invention; Figure 6 This is a schematic diagram of the siphon worm gear fan blade structure provided by the present invention; Figure 7 This is a schematic diagram of the siphon-enhanced heat dissipation fin structure provided by the present invention; Figure 8 This is a partial structural diagram of the siphon worm gear fan blade provided by the present invention; Figure 9 This is a schematic diagram of the winding assembly structure provided by the present invention.

[0023] The image shows: 1. Transformer housing; 2. High-voltage bushing; 201. High-voltage terminal; 3. Low-voltage bushing; 301. Low-voltage lead; 4. Three-dimensional wound core frame; 5. Three-dimensional wound yoke; 501. Core insulation support bar; 502. Core grounding plate; 503. Yoke pull plate; 6. Accessory tap changer; 7. Winding assembly; 701. High-voltage winding; 702. Low-voltage winding; 8. Magnetic reluctance joint buffer block; 9. Thermal expansion compensation connecting strip; 10. 11. Damping and vibration reduction pads; 12. Magnetic flux equalization rings; 13. Stress rolls; 14. Siphon-enhanced heat dissipation fins; 15. Siphon worm gear fan blades; 16. Connecting pipes; 17. Lead wire tap changers; 18. Electromagnetic decoupling isolation pads; 19. Discharge suppression microcavity cylinders; 20. Electric field gradient smooth transition end rings; 21. Base plate; 22. Reinforcing beams; 23. Distributed optical fiber temperature measurement embedded slots; 24. Resonant frequency avoidance buffer cylinders. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0025] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] Example 1: A three-dimensional wound core power transformer includes a transformer housing 1, a high-voltage bushing 2 and a low-voltage bushing 3 disposed on the transformer housing 1, a three-dimensional wound core frame 4 disposed inside the transformer housing 1, a three-dimensional wound yoke 5 disposed inside the three-dimensional wound core frame 4, an accessory tap connection plate 6 disposed on the upper part of the three-dimensional wound core frame 4, a winding assembly 7 disposed inside the three-dimensional wound core frame 4, an electromagnetic decoupling isolation pad 16 disposed at the lower part of the transformer housing 1, a discharge suppression microcavity cylinder 17 disposed on the side of the transformer housing 1, and an electric field gradient smooth transition end ring disk 18 disposed on the upper part of the transformer housing 1. Core insulation support bars 501 are disposed at intervals in the three-dimensional wound yoke 5, a core grounding plate 502 is disposed below the core insulation support bars 501, and a yoke pull plate 503 is disposed at the right end of the three-dimensional wound yoke 5.

[0027] The winding assembly 7 includes a high-voltage winding 701 and a low-voltage winding 702. A magnetic reluctance joint buffer block 8 is provided between the high-voltage winding 701 and the low-voltage winding 702. A thermal expansion compensation connecting strip 9 is provided on the right side of the high-voltage winding 701. A damping vibration reduction pad 10 is provided above the thermal expansion compensation connecting strip 9. A magnetic flux balancing ring 11 is provided below the high-voltage winding 701. A stress coil 12 is provided below the magnetic flux balancing ring 11.

[0028] The high-voltage bushing 2 is equipped with a high-voltage connector 201, and the low-voltage bushing 3 is equipped with a low-voltage lead 301. A siphon-enhanced heat dissipation fin 13 is provided on the side of the transformer housing 1, and a siphon worm gear blade 1301 is located below the siphon-enhanced heat dissipation fin 13. The high-voltage bushing 2 is connected to the transformer housing 1 via a connecting pipe 14, and a lead tap adapter 15 is provided on the side of the connecting pipe 14.

[0029] A base plate 19 is disposed below the electromagnetic decoupling isolation pad 16. A reinforcing beam 20 is disposed on the side of the base plate 19, and a distributed optical fiber temperature measurement embedding groove 21 is disposed on the side of the transformer housing 1. A resonant frequency avoidance buffer cylinder 22 is disposed on the side of the siphon-enhanced heat dissipation fins 13.

[0030] The working principle of a three-dimensional wound core power transformer: When the high-voltage side is connected to the power grid through the high-voltage bushing 2, the current flows into the high-voltage winding 701 through the high-voltage terminal 201; the low-voltage side outputs electrical energy from the low-voltage winding 702 through the low-voltage lead 301. The high-voltage winding 701 and the low-voltage winding 702 are concentrically mounted inside the three-dimensional wound core frame 4, with a magnetic reluctance joint buffer block 8 between them to reduce local eddy current losses caused by sudden changes in the magnetic circuit and improve coupling efficiency. The three-dimensional wound yoke 5 forms a closed magnetic circuit, and its unique winding structure makes the magnetic flux path symmetrical and uniform, significantly reducing no-load losses and noise. To balance the magnetic flux distribution, a magnetic flux equalization ring 11 is provided below the high-voltage winding 701, effectively suppressing magnetic flux distortion and improving magnetic field symmetry.

[0031] During operation, the high-voltage winding 701 undergoes thermal expansion due to temperature rise. Axial displacement is absorbed by the thermal expansion compensation connecting strip 9 on the right side, preventing winding deformation or insulation damage. A damping and vibration-damping pad 10 is installed above this connecting strip to suppress electromagnetic vibration transmission and reduce operating noise. Simultaneously, core insulation support strips 501 are provided at intervals of the three-dimensional coiled yoke 5, ensuring electrical isolation between core laminations and providing mechanical support. A core grounding plate 502 below it ensures reliable core grounding and prevents partial discharge caused by floating potential. A yoke pull plate 503 is fixed to the right end of the three-dimensional coiled yoke 5, enhancing the overall structural rigidity and preventing core loosening.

[0032] The transformer housing 1 integrates siphon-enhanced heat dissipation fins 13 on its side, utilizing natural convection and the siphon effect to accelerate heat dissipation. Below these fins, siphon worm gear fan blades 1301 rotate automatically under temperature difference drive, enhancing air turbulence and improving heat dissipation efficiency. Distributed fiber optic temperature sensing slots 21 embed fiber optic sensors to monitor the winding and core hotspot temperatures in real time, achieving precise temperature control.

[0033] An electromagnetic decoupling isolation pad 16 is provided at the bottom of the transformer housing 1, which cooperates with the base plate 19 to effectively isolate stray currents from the ground grid and external electromagnetic interference, improving the electromagnetic compatibility of the system. The discharge suppression microcavity cylinder 17 on the side of the housing suppresses local electric field concentration through its microcavity structure, preventing surface discharge. The electric field gradient smooth transition end ring disk 18 at the top optimizes the electric field distribution at the outlet of the high-voltage bushing 2, avoiding corona discharge. The high-voltage bushing 2 is connected to the housing 1 via a connecting pipe 14, and its side lead tap adapter 15 facilitates tap-changing voltage adjustment operations while maintaining sealing and insulation performance.

[0034] A reinforcing beam 20 is provided on the side of the base plate 19 to improve the overall support rigidity; the resonant frequency avoidance buffer cylinder 22 located next to the siphon-enhanced heat dissipation fins 13 avoids the inherent vibration frequency of the transformer through structural design, preventing resonance amplification of noise or structural fatigue. The stress roll 12 is located below the magnetic flux equalization ring 11 and is used to absorb the radial stress of the winding assembly 7 under the action of short-circuit electrodynamics to ensure operational safety.

[0035] The working process of a three-dimensional wound core power transformer: When the transformer is put into operation, the high-voltage side of the power grid is introduced through the high-voltage bushing 2 and connected to the internal high-voltage winding 701 through the high-voltage terminal 201 at the top; the low-voltage side power is output to the load system through the low-voltage winding 702 through the low-voltage lead 301 and the low-voltage bushing 3, thus completing the voltage reduction transmission of power.

[0036] At the instant of energization, alternating current flows through the high-voltage winding 701, generating an alternating magnetic field around it. This magnetic field forms a low-resistivity magnetic circuit through the closed three-dimensional wound core frame 4 and the internal three-dimensional wound yoke 5, efficiently coupling to the low-voltage winding 702. Based on the principle of electromagnetic induction, a corresponding voltage is induced in the low-voltage winding, realizing energy transfer. Because the three-dimensional wound core adopts a continuous winding, seamless structure, the magnetic flux path is symmetrical and uniform, significantly reducing hysteresis and eddy current losses, while also reducing vibration and noise.

[0037] During operation, the windings continuously generate heat due to the thermal effect of the current. This heat is conducted to the housing through the flux equalization ring 11 and stress drum 12, and dissipated outwards by the siphon-enhanced heat dissipation fins 13 on the side of the transformer housing 1. The temperature difference drives air to form a natural siphon flow between the fins, causing the siphon worm gear fan blades 1301 below to rotate automatically, enhancing convective heat transfer efficiency and achieving passive enhanced heat dissipation. Simultaneously, the distributed optical fiber temperature sensing embedding slots 21 embedded in the side wall of the housing collect real-time temperatures of key points in the windings and core, providing data support for condition monitoring and protection.

[0038] To cope with the mechanical stress caused by thermal expansion and electromagnetic force, a thermal expansion compensation connecting strip 9 is provided on the right side of the high-voltage winding 701. This strip can freely expand and contract along the axial direction, preventing damage to the insulation structure due to thermal expansion and contraction. The damping and vibration reduction pad 10 above it effectively absorbs and attenuates electromagnetic vibration, preventing vibration from being transmitted to the housing. The magnetic reluctance joint buffer block 8 is located between the high-voltage and low-voltage windings, which not only optimizes the magnetic circuit transition but also buffers the impact of electromagnetic force. The stress drum 12 further absorbs the huge radial electrodynamic force generated under short-circuit conditions, ensuring the integrity of the winding structure.

[0039] In terms of insulation and electric field control, the electric field gradient smooth transition end ring disk 18 is set at the top of the shell to make the electric field distribution at the high-voltage bushing outlet uniform and suppress corona discharge; the discharge suppression microcavity cylinder 17 on the side uses the microcavity structure to disperse the local high field strength area and prevent surface flashover. The core insulation support bar 501 ensures electrical isolation between the layers of the three-dimensional rolled yoke 5, and the core grounding plate 502 below it reliably grounds the core to eliminate the risk of floating potential; the yoke pull plate 503 fastens the end of the yoke and maintains the geometric stability of the core.

[0040] In terms of overall support and anti-interference, the electromagnetic decoupling isolation pad 16 is placed at the bottom of the housing, effectively blocking the conduction path of stray current from the ground grid and external electromagnetic interference, and improving the electromagnetic compatibility of operation; the base plate 19 below it, together with the side reinforcing beam 20, provides stable support. In addition, the resonant frequency avoidance buffer cylinder 22 is located on the side of the siphon-enhanced heat dissipation fins 13, and avoids the system's natural frequency through structural tuning to prevent mechanical resonance during operation.

[0041] Example 2: A three-dimensional wound core power transformer, wherein a three-dimensional wound core frame 4 is provided inside the transformer shell 1, a three-dimensional wound yoke 5 is provided inside the three-dimensional wound core frame 4, an accessory tap connection plate 6 is provided on the upper part of the three-dimensional wound core frame 4, a winding assembly 7 is provided inside the three-dimensional wound core frame 4, an electromagnetic decoupling isolation pad 16 is provided at the bottom of the transformer shell 1, a discharge suppression microcavity cylinder 17 is provided on the side of the transformer shell 1, and an electric field gradient smooth transition end ring disk 18 is provided on the top of the transformer shell 1. Core insulation support bars 501 are provided at intervals of the three-dimensional wound yoke 5, a core grounding plate 502 is provided below the core insulation support bars 501, and a yoke pull plate 503 is provided at the right end of the three-dimensional wound yoke 5. The winding assembly 7 includes a high-voltage winding 701 and a low-voltage winding 702, a magnetic reluctance joint buffer block 8 is provided between the high-voltage winding 701 and the low-voltage winding 702, and a thermal expansion compensation connecting strip 9 is provided on the right side of the high-voltage winding 701. A damping pad 10 is provided on the upper part of the thermal expansion compensation connecting strip 9, a magnetic flux balancing ring 11 is provided below the high voltage winding 701, and a stress drum 12 is provided below the magnetic flux balancing ring 11.

[0042] A high-voltage connector 201 is provided on the high-voltage bushing 2, and a low-voltage lead 301 is provided on the low-voltage bushing 3. A siphon-enhanced heat dissipation fin 13 is provided on the side of the transformer housing 1, and a siphon worm gear blade 1301 is provided below the siphon-enhanced heat dissipation fin 13. The high-voltage bushing 2 is connected to the transformer housing 1 via a connecting pipe 14, and a lead wire tap adapter 15 is provided on the side of the connecting pipe 14. A base plate 19 is provided below the electromagnetic decoupling isolation pad 16. A reinforcing beam 20 is provided on the side of the base plate 19, and a distributed optical fiber temperature sensing embedding groove 21 is provided on the side of the transformer housing 1. A resonant frequency avoidance buffer cylinder 22 is provided on the side of the siphon-enhanced heat dissipation fin 13.

[0043] The working process of a three-dimensional wound core power transformer: When the transformer is put into operation, the high-voltage side of the power grid is introduced through the high-voltage bushing 2 and connected to the internal high-voltage winding 701 through the high-voltage terminal 201 at the top; the low-voltage side power is output to the load system through the low-voltage winding 702 through the low-voltage lead 301 and the low-voltage bushing 3, thus completing the voltage reduction transmission of power.

[0044] The operator adjusts the number of tap turns of the high-voltage winding 701 using the accessory tap connector 6 and the lead tap adapter 15. The target output voltage is set based on the transformer ratio formula: in: High-voltage side input line voltage, unit: ; Low-voltage side output line voltage, unit: ; : Number of working turns in the high-voltage winding, in turns; Rated number of turns in the low-voltage winding, in turns; The leakage magnetic flux correction coefficient is determined by the air gap compensation of the magnetic reluctance joint buffer block 8. It is dimensionless and its value range is [not specified]. ; The permeability utilization coefficient of the three-dimensional wound iron core is determined by the proportion of interlayer air gaps in the core insulation support bar 501. It is dimensionless and its value range is [not specified]. ; After the wiring is completed, insulating oil is injected into the transformer housing 1 to the oil level threshold. The oil is pre-circulated through the microchannels of the siphon-enhanced heat dissipation fins 13 to ensure that the insulating oil fully submerges the winding assembly 7 and the three-dimensional core frame 4.

[0045] At the instant of energization, alternating current flows through the high-voltage winding 701, generating an alternating magnetic field around it. This magnetic field forms a low-resistivity magnetic circuit through the closed three-dimensional wound core frame 4 and the internal three-dimensional wound yoke 5, and is efficiently coupled to the low-voltage winding 702. Based on the principle of electromagnetic induction, a corresponding voltage is induced in the low-voltage winding, realizing energy transfer.

[0046] After closing, an excitation current is generated on the high-voltage side. Establish the main magnetic flux in the three-dimensional yoke 5. The main magnetic flux satisfies the following magnetomotive force balance equation: in: : Effective magnetic circuit length of the three-dimensional yoke 5, in units of ; Dynamic permeability of three-dimensional wound core material, in units of ; The effective cross-sectional area of ​​the three-dimensional rolled yoke 5, in units of ; The equivalent total air gap of the three-dimensional coiled yoke 5 is determined by the gap between the core insulating support bars 501 and the assembly gap of the yoke tie plate 503, and the unit is _____. Controlled within ; Vacuum permeability, a constant value ; The low-voltage winding 702 cuts the main magnetic flux and induces an no-load electromotive force. : ; in: Rated frequency of the power grid, in units of ; The winding factor of the low-voltage winding 702 is determined by the winding method, is dimensionless, and its value is... .

[0047] Because the three-dimensional wound core adopts a continuous winding and seamless structure, the magnetic flux path is symmetrical and uniform, which significantly reduces hysteresis and eddy current losses, while also reducing vibration and noise.

[0048] During operation, the windings continuously generate heat due to the thermal effect of the current. The heat is conducted to the housing through the flux equalization ring 11 and the stress drum 12, and dissipated outward by the siphon-enhanced heat dissipation fins 13 on the side of the transformer housing 1.

[0049] The flux equalization loop 11 generates compensating flux. The end leakage flux of the three-dimensional coiled yoke 5 is corrected to ensure that the deviation of the magnetic flux density at the winding ends does not exceed the limit. : in: The compensation coefficient is determined by the relative position of the flux equalization ring 11 and the high-voltage winding 701. It is dimensionless and its value is [value missing]. ; : Magnetic permeability of the material of flux equalization ring 11, in units of ; Cross-sectional area of ​​flux equalization ring 11, in units of ; : Circumference of flux equalization ring 11, in units of ; Temperature difference drives air to form a natural siphon flow between the fins, which in turn drives the siphon worm gear fan blades 1301 below to rotate automatically, enhancing convective heat transfer efficiency and achieving passively enhanced heat dissipation. At the same time, the distributed optical fiber temperature sensing slots 21 embedded in the side wall of the housing collect the temperature of key points of the winding and core in real time, providing data support for condition monitoring and protection.

[0050] To cope with the mechanical stress caused by thermal expansion and electromagnetic force, a thermal expansion compensation connecting strip 9 is provided on the right side of the high-voltage winding 701. This strip can freely expand and contract along the axial direction, preventing damage to the insulation structure due to thermal expansion and contraction. The damping and vibration reduction pad 10 above it effectively absorbs and attenuates electromagnetic vibration, preventing vibration from being transmitted to the housing. The magnetic reluctance joint buffer block 8 is located between the high-voltage and low-voltage windings, which not only optimizes the magnetic circuit transition but also buffers the impact of electromagnetic force. The stress drum 12 further absorbs the huge radial electrodynamic force generated under short-circuit conditions, ensuring the integrity of the winding structure.

[0051] In terms of insulation and electric field control, the electric field gradient smooth transition end ring disk 18 is set at the top of the shell to make the electric field distribution at the high voltage bushing outlet uniform and suppress corona discharge. The electric field gradient smoothing transition end ring disk 18 will smooth the electric field gradient at the end of the high-voltage bushing 2. Reduced to the insulation oil breakdown field strength threshold The following conditions are met: in: The radius of curvature of the high-voltage connector 201, in units of... ; The equivalent radius of the electric field gradient smooth transition end ring disk 18, in units of ; The power frequency breakdown field strength of insulating oil, in units of: No less than .

[0052] The side discharge suppression microcavity tube 17 utilizes the microcavity structure to disperse local high field strength areas and prevent surface flashover. The core insulation support bar 501 ensures electrical isolation between the layers of the three-dimensional coiled yoke 5, and the core grounding plate 502 below it reliably grounds the core, eliminating the risk of floating potential; the yoke pull plate 503 fastens the end of the yoke and maintains the geometric stability of the core.

[0053] In terms of overall support and anti-interference, the electromagnetic decoupling isolation pad 16 is placed at the bottom of the housing, effectively blocking the conduction path of stray current from the ground grid and external electromagnetic interference, and improving the electromagnetic compatibility of operation; the base plate 19 below it, together with the side reinforcing beam 20, provides stable support. In addition, the resonant frequency avoidance buffer cylinder 22 is located on the side of the siphon-enhanced heat dissipation fins 13, and avoids the system's natural frequency through structural tuning to prevent mechanical resonance during operation.

[0054] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A three-dimensional wound core power transformer, comprising a transformer housing (1), characterized in that, The transformer housing (1) is provided with a high-voltage bushing (2) and a low-voltage bushing (3). The transformer housing (1) is provided with a three-dimensional core frame (4). The three-dimensional core frame (4) is provided with a three-dimensional yoke (5). The upper part of the three-dimensional core frame (4) is provided with an accessory tap connection plate (6). The three-dimensional core frame (4) is provided with a winding assembly (7). The transformer housing (1) is provided with an electromagnetic decoupling isolation pad (16) at the bottom. The transformer housing (1) is provided with a discharge suppression microcavity cylinder (17) on the side. The transformer housing (1) is provided with an electric field gradient smooth transition end ring disk (18) at the top.

2. A three-dimensional wound core power transformer according to claim 1, characterized in that, The three-dimensional rolled iron yoke (5) is provided with iron core insulating support strips (501) at intervals, and iron core grounding plates (502) are provided below the iron core insulating support strips (501). The right end of the three-dimensional rolled iron yoke (5) is provided with an iron yoke pull plate (503).

3. A three-dimensional wound core power transformer according to claim 2, characterized in that, The winding assembly (7) includes a high-voltage winding (701) and a low-voltage winding (702). A magnetic reluctance joint buffer block (8) is provided between the high-voltage winding (701) and the low-voltage winding (702). A thermal expansion compensation connecting strip (9) is provided on the right side of the high-voltage winding (701).

4. A three-dimensional wound core power transformer according to claim 3, characterized in that, The upper part of the thermal expansion compensation connecting strip (9) is provided with a damping pad (10), the lower part of the high voltage winding (701) is provided with a magnetic flux equalization ring (11), and the lower part of the magnetic flux equalization ring (11) is provided with a stress drum (12).

5. A three-dimensional wound core power transformer according to claim 4, characterized in that, The high-voltage bushing (2) is provided with a high-voltage connector (201), and the low-voltage bushing (3) is provided with a low-voltage lead (301).

6. A three-dimensional wound core power transformer according to claim 5, characterized in that, The transformer housing (1) is provided with a siphon-enhanced heat dissipation fin (13) on its side, and a siphon worm gear fan blade (1301) is provided below the siphon-enhanced heat dissipation fin (13).

7. A three-dimensional wound core power transformer according to claim 6, characterized in that, The high-voltage bushing (2) is connected to the transformer housing (1) through a connecting pipe (14), and a lead wire tap adapter (15) is provided on the side of the connecting pipe (14).

8. A three-dimensional wound core power transformer according to claim 7, characterized in that, A base plate (19) is provided below the electromagnetic decoupling isolation pad (16).

9. A three-dimensional wound core power transformer according to claim 8, characterized in that, The base plate (19) is provided with a reinforcing beam (20) on its side, and the transformer housing (1) is provided with a distributed optical fiber temperature measurement embedding groove (21) on its side.

10. A three-dimensional wound core power transformer according to claim 9, characterized in that, The side of the siphon-enhanced heat dissipation fins (13) is provided with a resonant frequency avoidance buffer cylinder (22).

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