A short-circuit resistant distribution transformer

Abstract

The present invention discloses a short-circuit resistant distribution transformer, comprising an oil tank, a body, an iron core, and a coil, wherein the body is arranged inside the oil tank, the iron core is arranged on the body, and the coil comprises a high-voltage coil and a low-voltage coil, wherein the low-voltage coil is arranged inside the high-voltage coil, and the low-voltage coil is arranged outside the iron core. Main technical scheme and effect: The coil is compressed by insulating blocks at both ends, which effectively avoids the situation that a short circuit is easily generated when the coil is loose, and can increase the distance between the coil and the upper pressing plate and the lower pressing plate, thereby improving the insulation effect between the coil and the upper pressing plate and the lower pressing plate.

Description

Technical Field

[0001] The invention relates to the field of transformers, and in particular to a short-circuit resistant distribution transformer. Background Art

[0002] Oil-Immersed Distribution Transformer is a type of transformer widely used in power systems. It uses oil as an insulating medium and a cooling medium. Oil-immersed transformers are commonly found in low-voltage distribution networks. They are mainly used to convert high voltage to low voltage, or vice versa. They are usually used for power supply in distribution systems, factories, buildings, and residences.

[0003] The working principle of oil-immersed distribution transformer is similar to that of other types of transformers. Based on the principle of electromagnetic induction, the transformer consists of two sets of windings (high-voltage winding and low-voltage winding) and an iron core. The iron core guides the magnetic field into the windings through magnetic conductive materials. The current oil-immersed distribution transformer is prone to short circuits due to inadequate insulation. For example, short circuits are prone to occur between the coil and the body of the transformer. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to solve the problem of short circuit easily existing inside the oil-immersed distribution transformer in the prior art, and to provide a short-circuit resistant distribution transformer to achieve effective isolation between the internal coil and the upper pressure plate and the lower pressure plate, so as to achieve better insulation effect.

[0005] Technical solution:

[0006] The present application proposes a short-circuit resistant distribution transformer, comprising an oil tank, a body, an iron core, and a coil, wherein the body is arranged inside the oil tank, the iron core is arranged on the body, the coil comprises a high-voltage coil and a low-voltage coil, the low-voltage coil is arranged inside the high-voltage coil, and the low-voltage coil is arranged outside the iron core;

[0007] The device body is fixed inside the oil tank by hoisting, and the device body includes an upper bracket and a lower bracket, the upper bracket and the lower bracket are squeezed and fixed to each other, the iron core is arranged between the upper bracket and the lower bracket, and the bottom and top of the high-voltage coil and the low-voltage coil are respectively against the lower bracket and the upper bracket through insulating pads.

[0008] Preferably, the insulating pad includes a first pad and a second pad, the first pad is arranged at two ends of the opposite side of the upper bracket and the lower bracket, and respectively abuts against the high-voltage coil and the low-voltage coil, and the second pad is arranged at both sides of the opposite side of the upper bracket and the lower bracket, and respectively abuts against the high-voltage coil and the low-voltage coil.

[0009] Preferably, an oil channel is provided on the insulating spacer.

[0010] Preferably, the first cushion block is an isosceles trapezoidal structure with a notch at the bottom, and the second cushion block is a strip-shaped structure.

[0011] Preferably, a tank cover is provided at the top of the oil tank, and the top of the device body is connected to the tank cover via a first screw or a metal sheet.

[0012] Preferably, a plurality of second screw rods are provided through the upper bracket and the lower bracket, and two ends of the second screw rods are respectively fixed to the upper bracket and the lower bracket by screw thread extrusion.

[0013] Preferably, a reinforcing plate is provided on one side of the coils on both sides, and the upper end and the lower end of the reinforcing plate are respectively fixed to the upper bracket and the lower bracket.

[0014] Preferably, the gap distance between the device body and the oil tank is 18-25 mm.

[0015] Preferably, the conductor of the low-voltage coil is made of foil, and the conductor of the high-voltage coil is made of semi-hard copper enameled flat wire.

[0016] Preferably, the side walls of the reinforcement plate are provided with reinforcement ribs.

[0017] Beneficial effects: The coil is compressed by the insulating blocks at both ends, which effectively avoids the situation that short circuit is easy to occur when the coil is loose, and can increase the distance between the coil and the upper pressure plate and the lower pressure plate, improve the insulation effect between the coil and the upper pressure plate and the lower pressure plate, and prevent the coil from axial displacement after being impacted by a short circuit. In addition, through the setting of the oil channel, the heat dissipation effect of the coil during oil circulation is effectively improved, and the energy consumption of the equipment is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the internal structure of the fuel tank of the present invention from a top view;

[0019] Figure 2 It is a schematic diagram of the cross-sectional structure of the iron core and the coil of the present invention;

[0020] Figure 3 This is a schematic diagram of the metal sheet structure of the present invention;

[0021] Figure 4 This is a schematic diagram of the first screw structure of the present invention;

[0022] Figure 5 This is a schematic diagram of the structure of the first cushion block of the present invention;

[0023] Figure 6 This is a structural schematic diagram of a second cushion block from one perspective of the present invention;

[0024] Figure 7 This is a structural schematic diagram of the second cushion block of the present invention from another viewing angle;

[0025] Figure 8 It is a schematic diagram of the cross-sectional structure of the iron core of the present invention;

[0026] Fig. 9 It is a schematic diagram of the iron core structure of the present invention.

[0027] Reference numerals:

[0028] 1. Oil tank; 2. Instrument body; 3. Iron core; 4. Reinforcement ribs; 5. High-voltage coil; 6. Low-voltage coil; 7. Upper bracket; 8. Lower bracket; 9. Tank cover; 10. First cushion block; 11. Second cushion block; 12. Metal sheet; 13. First screw; 14. Second screw; 15. Reinforcement plate; 16. Oil channel; 17. Heat dissipation corrugated sheet. DETAILED DESCRIPTION

[0029] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the specific embodiments of the accompanying drawings.

[0030] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. 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. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0031] In view of the problems existing in the existing technology, such as Figure 1-9 As shown, a short-circuit resistant distribution transformer comprises an oil tank 1, a body 2, an iron core 3, and a coil, wherein the body 2 is arranged inside the oil tank 1, the iron core 3 is arranged on the body 2, and the coil comprises a high-voltage coil 5 and a low-voltage coil 6, wherein the low-voltage coil 6 is arranged inside the high-voltage coil 5, and the low-voltage coil 6 is arranged outside the iron core 3;

[0032] The device body 2 is fixed inside the oil tank 1 by hoisting. The device body 2 includes an upper bracket 7 and a lower bracket 8. The upper bracket 7 and the lower bracket 8 are squeezed and fixed to each other. The iron core 3 is arranged between the upper bracket 7 and the lower bracket 8. The bottom and top of the high-voltage coil 5 and the low-voltage coil 6 are respectively against the lower bracket 8 and the upper bracket 7 through insulating pads.

[0033] Specifically, the iron core 3 is the core component of electromagnetic induction, which is formed by stacking thin silicon steel sheets to reduce eddy current loss. The coil is divided into a high-voltage coil 5 and a low-voltage coil 6, which are respectively wound around the iron core 3 to achieve voltage conversion. The low-voltage coil 6 is located inside the high-voltage coil 5. This design helps to reduce the electrical impact of high voltage on the low-voltage side and improve safety. The relative position between the coil and the iron core 3 (the low-voltage coil 6 is on the periphery and the high-voltage coil 5 is on the inside) also helps to optimize the electromagnetic field distribution, reduce leakage magnetic flux and loss. The oil tank 1, as the outer shell of the entire transformer, not only provides necessary mechanical protection, but also helps heat dissipation and insulation through the internal insulating oil. While the upper bracket 7 and the lower bracket 8 squeeze the pad, the upper and lower pads can squeeze the top and bottom of the high-voltage coil 5 and the low-voltage coil 6, so that the high-voltage coil 5 and the low-voltage coil 6 can be effectively squeezed and compacted, effectively avoiding the situation where the coil is loose and short-circuited. The extrusion and fixing method between the upper bracket 7 and the lower bracket 8 enhances the stability of the body 2 and helps to resist the huge mechanical stress generated during short circuit.

[0034] In some preferred embodiments, the selected high-voltage coil 5 and low-voltage coil 6 have similar conductor current densities, and the high and low voltage coils 6 are highly consistent. When the conductor current densities of the high-voltage coil 5 and the low-voltage coil 6 are close, it means that the current passing through the two per unit length is similar, which helps to reduce the current imbalance between the coils, thereby reducing the vibration, noise and loss caused by electromagnetic imbalance. At the same time, the close current density also helps to improve the heat dissipation efficiency of the coil, reduce local overheating, and can effectively ensure the ampere-turn balance of the high and low voltage coils 6.

[0035] In some preferred embodiments, Figure 8 Small-capacity distribution transformers generally adopt an oblong core structure. The straight length of the core main stage thickness cannot be too large. The ratio of the main stage thickness (a) to the core diameter (b) is: a:b<3 / 4.

[0036] Specifically, small-capacity distribution transformers often use an oblong core structure, which helps to optimize electromagnetic performance and heat dissipation. When designing such a transformer, the ratio between the core's main stage thickness (a) and the core's diameter (b) is an important parameter. The ratio a:b < 3 / 4 limits the maximum possible value of the core's main stage thickness. Relative to the core's diameter, such a design helps to maintain the core's compactness, reduce magnetic leakage, and improve the efficiency of the transformer.

[0037] In some preferred embodiments, the insulating pad includes a first pad 10 and a second pad 11, wherein the first pad 10 is arranged at two ends of the opposite side of the upper bracket 7 and the lower bracket 8, respectively abutting against the high-voltage coil 5 and the low-voltage coil 6, and the second pad 11 is arranged at two sides of the opposite side of the upper bracket 7 and the lower bracket 8, respectively abutting against the high-voltage coil 5 and the low-voltage coil 6.

[0038] Specifically, the first pad 10 and the second pad 11 work together to ensure the correct position and stable support of the high-voltage coil 5 and the low-voltage coil 6 inside the transformer. They not only provide the necessary electrical isolation to prevent short circuits and leakage, but also enhance the structural stability of the transformer through mechanical support. This design helps to improve the reliability and service life of the transformer, and also helps to optimize its electrical performance.

[0039] In some preferred embodiments, the insulating spacer is provided with an oil channel 16, which allows cooling oil to circulate inside the transformer, thereby effectively taking away the heat generated by the coil and the core, which helps to reduce the temperature of the transformer and prevent overheating and insulation damage.

[0040] In some preferred embodiments, the first cushion block 10 is an isosceles trapezoidal structure with a notch at the bottom, and the second cushion block 11 is a strip-shaped structure.

[0041] Specifically, the shape of the first pad 10 can fit well with the bottom and top of the coil. The isosceles trapezoidal structure can provide better structural support. The notch on the first pad 10 can effectively produce better heat dissipation performance.

[0042] In some preferred embodiments, a tank cover 9 is provided at the top of the oil tank 1 , and the top of the body 2 is connected to the tank cover 9 via a first screw 13 or a metal sheet 12 .

[0043] Specifically, the first screw 13 is used for connection. The screw is a commonly used fastener. By rotating the screw, it can be passed through the holes of multiple components, and then locked by a nut or other fasteners to achieve the purpose of connection. The first screw 13 passes through the corresponding holes of the device body 2 and the box cover 9, and is locked by a nut or other fasteners to make the two tightly connected. The metal sheet 12 is used for connection. The metal sheet 12 is a special connecting piece, which can connect the device body 2 and the box cover 9 together by bolts, welding, riveting or other methods. The design of the metal sheet 12 may take into account factors such as connection strength, sealing, and ease of installation and disassembly. Moreover, through the first screw 13 or the metal sheet 12, when the device body is subjected to a short-circuit impact, there is no axial movement space, which effectively protects the transformer.

[0044] In some preferred embodiments, a heat dissipation corrugated sheet 17 is provided on the outer side of the oil tank 1 .

[0045] In some preferred embodiments, a plurality of second screw rods 14 are provided through the upper bracket 7 and the lower bracket 8 , and two ends of the second screw rods 14 are fixed to the upper bracket 7 and the lower bracket 8 by respectively squeezing the upper bracket 7 and the lower bracket 8 through threads.

[0046] Specifically, the second screw 14 cooperates with the reserved holes of the upper bracket 7 and the lower bracket 8 respectively through the threads at both ends thereof, and the screw is rotated to squeeze the brackets at both ends to achieve fixation. This fixing method is not only simple and reliable, but also can adjust the degree of tightening as needed to ensure a tight connection between the brackets. Since the upper bracket 7 and the lower bracket 8 need to support the weight of the high-voltage coil 5 and the low-voltage coil 6, as well as withstand various forces and vibrations during the operation of the transformer, the supporting role of the second screw 14 is crucial. They ensure the rigidity and stability of the bracket and prevent the coil from being displaced or deformed during the operation of the transformer.

[0047] In some preferred embodiments, a reinforcing plate 15 is provided on one side of the coils on both sides, and the upper end and the lower end of the reinforcing plate 15 are fixed to the upper bracket 7 and the lower bracket 8 respectively.

[0048] Specifically, the reinforcing plate 15 provides additional support for the coil through its solid structure and fixed connection with the upper and lower brackets 8, which helps prevent the coil from being deformed when the transformer is subjected to external forces (such as the electromagnetic force generated by the short-circuit current), thereby protecting the integrity and performance of the coil. The reinforcing plate 15 can also optimize the electromagnetic performance. By adjusting the shape, position and material of the reinforcing plate 15, the magnetic field distribution around the coil can be affected, thereby reducing leakage magnetic field and eddy current losses and improving the efficiency of the transformer.

[0049] In some preferred embodiments, the gap distance between the body 2 and the oil tank 1 is 18-25 mm.

[0050] Specifically, the gap between the transformer body 2 and the oil tank 1 helps the heat inside the transformer to be dissipated to the external environment through natural convection or forced air cooling. The appropriate gap distance can ensure smooth heat transfer and prevent excessive temperature rise caused by heat accumulation.

[0051] In some preferred embodiments, the reinforcing plate 15 is formed by integrally bending an 8 mm steel plate.

[0052] Specifically, the 8 mm steel plate thickness ensures that the reinforcing plate 15 has sufficient load-bearing capacity to effectively support the weight of the coil and resist various forces and vibrations generated during the operation of the transformer. The rigidity of the steel plate helps to maintain the shape and position of the coil stable and prevent deformation or damage due to force.

[0053] In some preferred embodiments, the conductor of the low-voltage coil 6 is made of foil, and the conductor of the high-voltage coil 5 is made of semi-hard copper enameled rectangular wire.

[0054] Specifically, the foil-wrapped conductor, due to its wider cross-section, can provide a larger heat dissipation area, which helps to dissipate the heat inside the coil more quickly, thereby improving the thermal stability and service life of the transformer. The foil-wrapped conductor has a relatively small resistance, which can reduce the heat loss generated when current passes through, thereby improving the efficiency of the transformer. The semi-hard copper enameled flat wire has high mechanical strength and can withstand greater mechanical stress and vibration, ensuring the stability and reliability of the high-voltage coil 5 during the operation of the transformer. The enameled layer provides good insulation properties, which can prevent current leakage and short circuit, ensuring the safe operation of the high-voltage coil 5.

[0055] In some preferred embodiments, the side wall of the reinforcing plate 15 is provided with at least two 20*25 mm reinforcing ribs 4. The reinforcing ribs 4 serve as additional supporting structures, which can significantly improve the bending strength and shear strength of the reinforcing plate 15, which helps prevent the reinforcing plate 15 from being deformed or damaged due to force during the operation of the transformer, thereby protecting the coil and other key components.

[0056] The above is only a specific implementation of the embodiment of the present invention, but the protection scope of the embodiment of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiment of the present invention should be included in the protection scope of the embodiment of the present invention. Therefore, the protection scope of the embodiment of the present invention should be based on the protection scope of the claims.

Claims

1. A short-circuit resistant distribution transformer, characterized in that: The device comprises an oil tank (1), a device body (2), an iron core (3), and a coil, wherein the device body (2) is arranged inside the oil tank (1), the iron core (3) is arranged on the device body (2), the coil comprises a high-voltage coil (5) and a low-voltage coil (6), the low-voltage coil (6) is arranged inside the high-voltage coil (5), and the low-voltage coil (6) is arranged outside the iron core (3); The device body (2) is fixed inside the oil tank (1) by hoisting, and the device body (2) comprises an upper bracket (7) and a lower bracket (8), the upper bracket (7) and the lower bracket (8) are pressed and fixed to each other, the iron core (3) is arranged between the upper bracket (7) and the lower bracket (8), and the bottom and top of the high-voltage coil (5) and the low-voltage coil (6) are respectively abutted against the lower bracket (8) and the upper bracket (7) through insulating pads.

2. The transformer according to claim 1, characterized in that: The insulating pad block comprises a first pad block (10) and a second pad block (11); the first pad block (10) is arranged at two ends of the upper bracket (7) and the lower bracket (8) facing each other, respectively abutting against the high-voltage coil (5) and the low-voltage coil (6); and the second pad block (11) is arranged at two sides of the upper bracket (7) and the lower bracket (8) facing each other, respectively abutting against the high-voltage coil (5) and the low-voltage coil (6).

3. The transformer according to claim 2, characterized in that: An oil channel (16) is provided on the insulating cushion block.

4. The transformer according to claim 2, characterized in that: The first cushion block (10) is an isosceles trapezoidal structure with a notch at the bottom, and the second cushion block (11) is a strip-shaped structure.

5. The transformer according to claim 1, characterized in that: The top end of the oil tank (1) is provided with a tank cover (9), and the top end of the body (2) is connected to the tank cover (9) via a first screw rod (13) or a metal sheet (12).

6. The transformer according to claim 1, characterized in that: A plurality of second screw rods (14) are provided through the upper bracket (7) and the lower bracket (8), and two ends of the second screw rods (14) are respectively fixed to the upper bracket (7) and the lower bracket (8) by screw thread extrusion.

7. The transformer according to claim 1, characterized in that: A reinforcing plate (15) is provided on one side of the coils on both sides, and the upper end and the lower end of the reinforcing plate (15) are respectively fixed to the upper bracket (7) and the lower bracket (8).

8. The transformer according to claim 1, characterized in that: The gap distance between the body (2) and the oil tank (1) is 18-25 mm.

9. The transformer according to claim 1, characterized in that: The conductor of the low-voltage coil (6) is made of foil, and the conductor of the high-voltage coil (5) is made of semi-hard copper enameled flat wire.

10. The transformer according to claim 7, characterized in that: The side wall of the reinforcement plate (15) is provided with reinforcement ribs (4).

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