Improved low-loss high-reliability distribution transformer

Abstract

The improved low-loss high-reliability distribution transformer comprises an oil tank, and an oil tank radiator, a high-voltage cable sleeve, a low-voltage sleeve and an on-load switch are arranged on the oil tank; an iron core unit is arranged in the oil tank, and a low-voltage coil and a high-voltage coil are sleeved outside the iron core unit; vegetable oil is injected into the welding type oil tank, and a capsule is arranged above the oil surface of the vegetable oil. The low-voltage coil is connected with a low-voltage sleeve, the high-voltage coil is connected with an on-load switch, and the on-load switch is connected with a high-voltage cable sleeve; the planar laminated iron core structure is adopted to replace an original planar rolled iron core mechanical sleeving and winding mode, meanwhile, the laminated iron core is of a five-step type laminated iron core structure, the structure fully utilizes the space in the circular coil, the magnetic circuit efficiency is improved, the use amount of silicon steel sheets is reduced, and the gap between the coil and the iron core is reduced by adopting the sleeving mode.

Description

Technical Field

[0001] This invention relates to the field of distribution transformer technology, specifically to an improved low-loss, high-reliability distribution transformer. Background Technology

[0002] In China's power grid, the most commonly used transformers online are Type 11 high-energy-consuming oil-immersed distribution transformers, some of which have been in operation for nearly ten years. With the increasing national emphasis on energy conservation and carbon reduction in recent years, and the large-scale investment in new energy-efficient oil-immersed distribution transformers in the power grid, upgrading the currently operating Type 11 transformers to high-reliability, low-loss products that meet the requirements of modern power grid operation offers significant economic and social benefits. Summary of the Invention

[0003] The purpose of this invention is to provide an improved low-loss, high-reliability distribution transformer to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an improved low-loss, high-reliability distribution transformer, comprising an oil tank, wherein the oil tank is provided with an oil tank radiator, a high-voltage cable bushing, a low-voltage bushing, and an on-load switch; the oil tank contains an iron core unit, and the iron core unit is externally fitted with a low-voltage coil and a high-voltage coil; vegetable oil is injected into the welded oil tank, and a capsule is provided above the surface of the vegetable oil; the low-voltage coil is connected to the low-voltage bushing, the high-voltage coil is connected to the on-load switch, and the on-load switch is connected to the high-voltage cable bushing; the iron core unit comprises an upper iron core yoke, laminated iron core blocks, a stacked iron core, interleaved laminated iron core blocks, and a lower iron core yoke, wherein the stacked iron core is a five-step stacked iron core structure.

[0005] Optionally, the five-step stacked core structure of the stacked core is characterized by the stepped staggered arrangement of the joints of the silicon steel sheets.

[0006] Optionally, the low-voltage coil is a foil coil structure.

[0007] Optionally, the high-voltage coil is a linear voltage regulator to achieve on-load voltage regulation improvement.

[0008] Optionally, the oil tank radiator is a plate-type radiator.

[0009] Optionally, the high-voltage cable sleeve is a high-voltage elbow-type cable sleeve.

[0010] Optionally, the low-pressure bushing is a low-pressure integrated epoxy cast bushing.

[0011] Optionally, the fuel tank is integrally welded, and the tank cover is fitted with an explosion-proof film.

[0012] An improved method for assembling a low-loss, high-reliability distribution transformer, wherein the distribution transformer is assembled by first stacking the core and the lower yoke of the core, then inserting the high-voltage coil and the low-voltage coil, and finally inserting the upper yoke of the core.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention adopts a planar stacked core structure to replace the original planar wound core mechanical winding method. At the same time, the stacked core is a five-step stacked core structure. This structure makes full use of the space inside the circular coil, improves the magnetic circuit efficiency, and reduces the amount of silicon steel sheets used. The use of the stacking method reduces the gap between the coil and the core. 2. The low-voltage coil of this invention is a foil winding, which improves the transformer's operating loss, with both no-load loss and load loss being significantly reduced, thereby improving power supply reliability and reducing carbon emissions. 3. The oil tank with a capsule in this invention is more reliable, and the oil does not come into direct contact with air, thus extending its service life; 4. The assembly method of this invention avoids scratches and bumps to the insulating coating on the surface of silicon steel sheets during the "disassembly-assembly" process in traditional processes. Attached Figure Description

[0014] Figure 1 This is the first front view of the present invention; Figure 2 This is the second front view of the present invention; Figure 3 This is a schematic diagram of the core unit of the present invention; Figure 4 This is a schematic diagram of the coil structure of the present invention; Figure 5 for Figure 4 Schematic diagram at point BB; Figure 6 for Figure 4 A schematic diagram at point CC; Figure 7 This is a side view of the stacked iron core of the present invention; Figure 8 This is a schematic diagram of the structure of the laminated wood block with iron core according to the present invention; Figure 9 This is a schematic diagram of the structure of the laminated wood block with alternating iron cores according to the present invention. Detailed Implementation

[0015] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0016] like Figure 1-9As shown, an improved low-loss, high-reliability distribution transformer includes an oil tank 2, on which an oil tank radiator 1, a high-voltage cable bushing 7, a low-voltage bushing 5, and an on-load switch 6 are provided; an iron core unit 3 is provided inside the oil tank 2, and a low-voltage coil 9 and a high-voltage coil 10 are fitted outside the iron core unit 3; vegetable oil 4 is injected into the oil tank 2, and a capsule 8 is provided above the oil surface of the vegetable oil 4; the low-voltage coil 9 is connected to the low-voltage bushing 5, the high-voltage coil 10 is connected to the on-load switch 6, and the on-load switch 6 is connected to the high-voltage cable bushing 7; the iron core unit 3 consists of an upper iron core yoke 31, laminated iron core blocks 32, a stacked iron core 33, interleaved laminated iron core blocks 34, and a lower iron core yoke 35, wherein the stacked iron core 33 is a five-step stacked iron core structure.

[0017] The structure adopts a stacked iron core sleeve structure, using stacked iron core laminated wood blocks 32 and stacked iron core alternating laminated wood blocks 34. The overall structure has high strength and small dimensional gaps. Furthermore, it can be processed with oil flow channels, which greatly improves the strength and ensures smooth oil flow.

[0018] The five-step stacked core structure of the stacked core 33 is characterized by a stepped staggered arrangement of the joints of the silicon steel sheets, with a circular cross-section, which can significantly reduce the no-load loss of the core.

[0019] The low-voltage coil 9 has a foil coil structure, which improves the transformer's short-circuit withstand capability and allows for increased stacking surface area to reduce low-voltage coil losses. The high-voltage coil 10 is a linear voltage regulator, achieving improved on-load voltage regulation.

[0020] The high-voltage cable bushing 7 is a high-voltage elbow-type cable bushing, and the low-voltage bushing 5 is a low-voltage integrated epoxy cast bushing, which increases the transformer's sealing and overall strength.

[0021] The oil tank radiator 1 is a plate-type radiator, and the oil tank 2 is integrally welded with an explosion-proof membrane added to the tank cover to enhance the overall strength of the oil tank. To improve the service life of the low-loss transformer, a sealed oil tank 2 with a capsule 8 structure is adopted to prevent the transformer oil from exchanging with the outside air. This also reduces the use of transformer oil. Furthermore, a certain air gap exists between the transformer tank cover and the transformer body, which can improve the reliability and service life of the transformer.

[0022] An improved method for assembling a low-loss, high-reliability distribution transformer is provided. During assembly, the distribution transformer is first stacked with the core 33 and the lower core yoke 35, then the high-voltage coil 10 and the low-voltage coil 9 are inserted, and finally the upper core yoke 31 is inserted.

[0023] This assembly method avoids scratches and bumps to the insulating coating on the silicon steel sheet surface during the "disassembly-assembly" process in traditional processes. Coating damage leads to increased local eddy current losses in the iron core, directly manifesting as increased no-load losses and noise. Furthermore, the magnetic circuit is precisely closed by the worker only during the final assembly. All joints (the junction between the yoke and the core column) are completed under conditions of unobstructed view and good visibility, resulting in tighter, more uniform joints, lower magnetic resistance, superior magnetic circuit performance, and extremely high consistency. The process is simplified, eliminating the time spent on repeated lamination and disassembly, making assembly smoother, more automated, and significantly improving production efficiency and product consistency.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An improved low-loss, high-reliability distribution transformer, characterized in that, The system includes an oil tank (2), on which are provided an oil tank radiator (1), a high-voltage cable sleeve (7), a low-voltage sleeve (5), and an on-load switch (6); an iron core unit (3) is provided inside the oil tank (2), and a low-voltage coil (9) and a high-voltage coil (10) are fitted on the outside of the iron core unit (3); vegetable oil (4) is injected into the oil tank (2), and a capsule (8) is provided above the surface of the vegetable oil (4); the low-voltage coil (9) is connected to the low-voltage sleeve (5), the high-voltage coil (10) is connected to the on-load switch (6), and the on-load switch (6) is connected to the high-voltage cable sleeve (7); The iron core unit (3) consists of an upper iron core yoke (31), stacked iron core laminated wood blocks (32), stacked iron core (33), stacked iron core alternating laminated wood blocks (34), and lower iron core yoke (35). The stacked iron core (33) is a five-step stacked iron core structure.

2. The improved low-loss, high-reliability distribution transformer according to claim 1, characterized in that, The five-step stacked core structure of the stacked iron core (33) is that the joints of the silicon steel sheets are arranged in a stepped staggered manner.

3. An improved low-loss, high-reliability distribution transformer according to claim 2, characterized in that, The low-voltage coil (9) has a foil coil structure.

4. An improved low-loss, high-reliability distribution transformer according to claim 3, characterized in that, The high-voltage coil (10) is a linear voltage regulator, which improves on-load voltage regulation.

5. An improved low-loss, high-reliability distribution transformer according to claim 4, characterized in that, The oil tank radiator (1) is a plate-type radiator.

6. An improved low-loss, high-reliability distribution transformer according to claim 5, characterized in that, The high-voltage cable sleeve (7) is a high-voltage elbow type cable sleeve.

7. An improved low-loss, high-reliability distribution transformer according to claim 6, characterized in that, The low-pressure bushing (5) is a low-pressure integrated epoxy casting type bushing.

8. An improved low-loss, high-reliability distribution transformer according to claim 7, characterized in that, The oil tank (2) is integrally welded, and the tank cover is covered with an explosion-proof film.

9. An assembly method for an improved low-loss, high-reliability distribution transformer, comprising assembling the distribution transformer as described in claims 1-8, characterized in that, When assembling the distribution transformer, the core (33) and the lower yoke (35) are first stacked, then the high-voltage coil (10) and the low-voltage coil (9) are inserted, and finally the upper yoke (31) is inserted.

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