Novel special offshore dry-type transformer

Abstract

The utility model relates to a novel special offshore dry-type transformer which is better in using effect and good in heat dissipation effect when being used on the sea, and an iron core in a dry-type transformer body is composed of an upper iron yoke, a lower iron yoke and three iron core columns. The three iron core columns are respectively sleeved with a high-voltage coil group and a low-voltage coil group, low-voltage coils in the high-voltage coil group and the low-voltage coil group are located in high-voltage coils, the iron core columns are circular columns, the low-voltage coils are circular coils, and twelve supporting strips are vertically arranged between the outer wall surfaces of the iron core columns and the inner wall surfaces of the low-voltage coils and are distributed at equal intervals. The novel offshore special dry-type transformer has the advantages that the low-voltage coil and the iron core column are designed to be in a regular circle shape, and the 12-equal-part tight supporting structure is adopted between the low-voltage coil and the iron core column, so that the stress of the low-voltage coil and the iron core column which are tightly supported by the twelve supporting strips is more uniform, the anti-seismic performance of the dry-type transformer body can be improved, and the service life of the dry-type transformer body is prolonged; therefore, the using effect of the dry-type transformer used on the sea is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of dry-type transformers, and in particular relates to a novel dry-type transformer for offshore use. Background Art

[0002] CN 114898992 A, titled "A 66kV high voltage level, 10MVA large capacity offshore wind power dry-type transformer", comprises: an iron core; high and low voltage coils wound on the iron core, a cooling air duct is arranged inside the high voltage coil; a grading ring is arranged at the upper and lower ends of the coil; an umbrella skirt is arranged outside the transformer casting body. It also comprises a clamping plate arranged at the upper and lower ends of the iron core, the iron core is fixed by the clamping plate and the insulating pad, and the clamping plate fixes the iron core by screws. The high voltage coil comprises an inner high voltage coil and an outer high voltage coil, the cooling air duct is arranged between the inner high voltage coil and the outer high voltage coil, and the coils wound on the iron core are respectively a low voltage coil, an inner high voltage coil and an outer high voltage coil from the inside to the outside. The low voltage coil and the high voltage coil are both cast with epoxy resin insulation material. The insulating pad is fixed by a baffle led out from the clamping plate, the led baffle is V-shaped, the insulating pad is arranged on the lower end surface of the baffle, and the pad presses the inner high voltage coil, the outer high voltage coil and the low voltage coil to fix them on the outer wall of the iron core. The voltage-equalizing ring is made of semi-conductive silicone rubber material, and is fixed to the end of the high-voltage coil with fasteners. The cross-sectional shape of the voltage-equalizing ring is three-quarters of a circle or a semicircle. The umbrella skirt is made of silicone rubber insulating material, and is composed of a plurality of umbrellas, specifically 8-15 in a group, with one group at the upper and lower ends. The cooling air duct is arranged between the inner high-voltage coil and the outer high-voltage coil, and a number of supporting struts are arranged between the air ducts. The struts are distributed in the air duct at equidistant intervals and are fixed by fasteners at the upper and lower ends of the coil to ensure that the positions of the inner high-voltage coil and the outer high-voltage coil are not offset. The voltage-equalizing ring is installed at the upper and lower ends of the outer high-voltage coil. There are cooling air ducts between the iron core and the low-voltage coil, and between the low-voltage coil and the inner high-voltage coil. The air ducts are used for heat dissipation. A cross-flow fan is installed at the bottom of the transformer body. There are six cross-flow fans, which are respectively on both sides of the bottom of the three-phase winding. The air direction of the cross-flow fan is the bottom of the cross-flow fan, the cross-flow fan, and the top of the cross-flow fan. The cross-flow fan blows air into the three cooling air ducts of the transformer, and the air is discharged from the top of the transformer along the cooling air duct, thereby forming a forced air cooling system. The material of the cross-flow fan is stainless steel, and the outer surface is also provided with an anti-corrosion coating. The disadvantage is that when the offshore wind turbine cabin vibrates frequently and violently, the low-voltage coil and the iron core column of this 66kV high-voltage dry-type transformer with a large capacity of 10MVA are prone to loosening, thereby affecting the use effect of the dry-type transformer. Utility Model Content

[0003] Design purpose: In order to avoid the shortcomings of the background technology, a new type of offshore dry-type transformer is designed, which not only has better performance when used at sea, but also has good heat dissipation effect.

[0004] Design plan: To achieve the above design objectives.

[0005] 1. The iron core in the dry-type transformer body is composed of an upper iron yoke, a lower iron yoke and three iron core columns, and the three iron core columns are vertically arranged side by side between the upper iron yoke and the lower iron yoke, the upper iron yoke is located directly above the lower iron yoke, and the three iron core columns are respectively equipped with a high and low voltage coil group, and the low voltage coil in the high and low voltage coil group is located inside the high voltage coil, the iron core column is a circular column, and the low voltage coil is a circular coil. Twelve struts are vertically arranged between the outer wall surface of the iron core column and the inner wall surface of the low voltage coil, and the twelve struts are equidistantly distributed. The design that the length of the strut matches the height of the low voltage coil is one of the technical features of the utility model. The purpose of such design is that the iron core in the dry-type transformer body is composed of an upper iron yoke, a lower iron yoke and three iron core columns, and the three iron core columns are vertically arranged side by side between the upper iron yoke and the lower iron yoke, the upper iron yoke is located directly above the lower iron yoke, and the three iron core columns are respectively equipped with a high- and low-voltage coil group, and the low-voltage coil in the high- and low-voltage coil group is located inside the high-voltage coil, the iron core column is a circular column, the low-voltage coil is a circular coil, and twelve support bars are vertically arranged between the outer wall surface of the iron core column and the inner wall surface of the low-voltage coil. The twelve stays are evenly distributed, and the length of the stays matches the height of the low-voltage coil. The low-voltage coil and the core column are designed to be a perfect circle, and a 12-part support structure is used between the low-voltage coil and the core column. This makes the force on the two supported by the twelve stays more uniform, which can improve the seismic performance of the dry-type transformer body. In addition, the overall load loss (kW) of the dry-type transformer (66KV grade transformer) is tested to be ≤70 (national standard value 75), no-load loss (kW): ≤14 (national standard value 15),

[0006] Noise sound pressure level (dB): ≤80 (national standard value 85), thereby improving the use effect of dry-type transformers when used at sea.

[0007] 2. One side of the support bar is an inner concave arc surface and the other side of the support bar is an outer convex arc surface. When the support bar is tightly arranged between the iron core column and the low-voltage coil, the inner concave arc surface of the support bar is in surface-to-surface contact with the outer circular surface of the iron core column, and the outer convex arc surface of the support bar is in surface-to-surface contact with the inner circular surface of the low-voltage coil. The upper end surface of the support bar is provided with a through hole, and the through hole passes through the upper and lower end surfaces of the support bar. This design is the second technical feature of the present utility model. The purpose of such design is: first, one side of the support bar is an inner concave arc surface and the other side of the support bar is an outer convex arc surface. When the support bar is tightly arranged between the iron core column and the low-voltage coil, the inner concave arc surface of the support bar and the outer convex arc surface of the support bar are in surface-to-surface contact with the outer circular surface of the iron core column, and the outer convex arc surface of the support bar and the inner circular surface of the low-voltage coil are in surface-to-surface contact. Such structural design can increase the contact area between the support bar and the iron core column and the low-voltage coil, thereby improving the tightening effect of the support bar on the iron core column and the low-voltage coil; second, the upper end surface of the support bar is provided with a through hole and the through hole passes through the upper and lower end surfaces of the support bar. The setting of the through hole is conducive to air circulation, which can improve the heat dissipation effect of the dry-type transformer.

[0008] 3. The high-voltage coil includes a first coil layer, a second coil layer, a third coil layer, a first air duct and a second air duct. A second coil layer is provided on the outside of the first coil layer and a third coil layer is provided on the outside of the second coil layer. A first air duct is formed between the first coil layer and the second coil layer by arranging a plurality of support bars, and a second air duct is formed between the second coil layer and the third coil layer by arranging a plurality of support bars. This design is the third technical feature of the utility model. The purpose of such a design is that the high-voltage coil includes a first coil layer, a second coil layer, a third coil layer, a first air duct and a second air duct. A second coil layer is provided on the outside of the first coil layer and a third coil layer is provided on the outside of the second coil layer. A first air duct is formed between the first coil layer and the second coil layer by arranging a plurality of support bars, and a second air duct is formed between the second coil layer and the third coil layer by arranging a plurality of support bars. The arrangement of the first air duct and the second air duct greatly improves the heat dissipation effect of the high-voltage coil.

[0009] 4. The design that both the low-voltage coil and the high-voltage coil are cast with silicone rubber is the fourth technical feature of the utility model. The purpose of this design is that both the low-voltage coil and the high-voltage coil are cast with silicone rubber, which has excellent insulation performance, and the insulation heat-resistant temperature reaches 250°C. Silicone rubber also has damping elasticity and is not easy to crack when alternating between hot and cold.

[0010] 5. The design that two rows of cooling fans are arranged on the base of the dry-type transformer body is the fifth technical feature of the utility model. The purpose of such design is that two rows of cooling fans are arranged on the base of the dry-type transformer body, and the cooling fans can further improve the heat dissipation effect of the dry-type transformer.

[0011] Technical solution: A new type of offshore special dry-type transformer, including a dry-type transformer body, wherein the iron core in the dry-type transformer body is composed of an upper iron yoke, a lower iron yoke and three iron core columns, and the three iron core columns are vertically arranged side by side between the upper iron yoke and the lower iron yoke, the upper iron yoke is located directly above the lower iron yoke, and the three iron core columns are respectively provided with a high and low voltage coil group, and the low voltage coil in the high and low voltage coil group is located inside the high voltage coil, the iron core column is a circular column, and the low voltage coil is a circular coil, and twelve struts are vertically arranged between the outer wall surface of the iron core column and the inner wall surface of the low voltage coil, and the twelve struts are equidistantly distributed, and the length of the struts matches the height of the low voltage coil.

[0012] Compared with the background technology, the utility model is, firstly, a new type of offshore dry-type transformer, which designs the low-voltage coil and the core column into a perfect circle, and adopts a 12-equally divided support structure between the low-voltage coil and the core column, so that the two parts supported by twelve support bars are more evenly stressed, which can improve the seismic performance of the dry-type transformer body, thereby improving the use effect of the dry-type transformer when used at sea; secondly, the new type of offshore dry-type transformer has good heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a structural diagram of a new type of offshore special dry-type transformer.

[0014] Figure 2 This is a schematic diagram of the structure of the iron core in a new type of offshore special dry-type transformer.

[0015] Figure 3 It is a top view structural diagram of the high-voltage coil in a new type of offshore special dry-type transformer.

[0016] Figure 4 It is a top view structural diagram of a support bar in a new type of offshore dry-type transformer. DETAILED DESCRIPTION

[0017] Example 1: Refer to the attached Figure 1-Figure 4 A novel offshore dry-type transformer comprises a dry-type transformer body 1, wherein the iron core 2 in the dry-type transformer body 1 is composed of an upper iron yoke 21, a lower iron yoke 22 and three iron core columns 23, and the three iron core columns 23 are vertically arranged side by side between the upper iron yoke 21 and the lower iron yoke 22, the upper iron yoke 21 is located directly above the lower iron yoke 22, and the three iron core columns 23 are respectively provided with a high- and low-voltage coil group 3, and the low-voltage coil 31 in the high- and low-voltage coil group 3 is located inside the high-voltage coil 32, the iron core column 23 is a circular column, and the low-voltage coil 31 is a circular coil, and twelve stays 4 are vertically arranged between the outer wall surface of the iron core column 23 and the inner wall surface of the low-voltage coil 31, and the twelve stays 4 are equidistantly distributed, and the length of the stays 4 matches the height of the low-voltage coil 31.

[0018] One side of the support bar 4 is an inner concave arc surface 41 and the other side of the support bar 4 is an outer convex arc surface 42. When the support bar 4 is tightly arranged between the core column 23 and the low-voltage coil 31, the inner concave arc surface 41 of the support bar 4 is in surface-to-surface contact with the outer circular surface of the core column 23 and the outer convex arc surface 42 of the support bar 4 is in surface-to-surface contact with the inner circular surface of the low-voltage coil 31. The upper end surface of the support bar 4 is provided with a through hole 43 and the through hole 43 passes through the upper and lower end surfaces of the support bar 4.

[0019] The high-voltage coil 32 includes a first coil layer 321, a second coil layer 322, a third coil layer 323, a first air duct 324 and a second air duct 325. The second coil layer 322 is provided on the outer side of the first coil layer 321 and the third coil layer 323 is provided on the outer side of the second coil layer 322. A first air duct 324 is formed between the first coil layer 321 and the second coil layer 322 by arranging a plurality of support bars 326. A second air duct 325 is formed between the second coil layer 322 and the third coil layer 323 by arranging a plurality of support bars 326.

[0020] The low-voltage coil 31 and the high-voltage coil 32 are both cast with silicone rubber. The offshore wind turbine cabin is small, and the transformer is characterized by large capacity, high current and high voltage. The general capacity reaches 10000KVA, the high-voltage side voltage is 69KV, and the low-voltage side voltage is 1.14KV. Through the use of silicone rubber casting technology for high and low voltage coils, the silicone rubber material has excellent insulation properties, and the insulation heat resistance temperature reaches 250°C. Silicone rubber also has damping elasticity and is not easy to crack due to alternating hot and cold. The volume of the conventional 66KV grade transformer is reduced by 40% using silicone rubber casting technology. Two rows of cooling fans 5 are provided on the base of the dry-type transformer body 1. The low-voltage coil 31 is formed by copper foil winding.

[0021] In order to adapt to the operating environment of offshore wind power dry-type transformers, the high-voltage lead structure adopts silicone rubber one-piece molded cast lead, the terminal joint adopts a fully sealed T-type head, and the uniquely designed all-round insulation system ensures the electrical insulation distance requirements and meets the environmental E3 requirements: salt spray environment conductivity 3.6-4s / m, condensation humidity> 95%. In addition, the transformer meets the climate C3 requirements: suitable for storage and transportation at -40℃, and operation at -25℃. Meet the combustion performance level F1 requirements: non-toxic, odorless, non-volatile, and non-combustible.

[0022] It should be understood that although the above embodiments provide a relatively detailed textual description of the design concept of the present utility model, these textual descriptions are only simple textual descriptions of the design concept of the present utility model, rather than limitations on the design concept of the present utility model. Any combination, addition or modification that does not exceed the design concept of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A novel offshore dry-type transformer, comprising a dry-type transformer body (1), wherein the iron core (2) in the dry-type transformer body (1) is composed of an upper iron yoke (21), a lower iron yoke (22) and three iron core columns (23), and the three iron core columns (23) are arranged vertically side by side between the upper iron yoke (21) and the lower iron yoke (22), the upper iron yoke (21) is located directly above the lower iron yoke (22), and the three iron core columns (23) are respectively mounted with a high- and low-voltage coil group (3), and the low-voltage coil (31) in the high- and low-voltage coil group (3) is located inside the high-voltage coil (32), wherein: The core column (23) is a circular column, the low-voltage coil (31) is a circular coil, twelve support bars (4) are vertically arranged between the outer wall surface of the core column (23) and the inner wall surface of the low-voltage coil (31), and the twelve support bars (4) are evenly distributed, and the length of the support bars (4) matches the height of the low-voltage coil (31).

2. A novel offshore special dry-type transformer according to claim 1, characterized in that: One side of the support bar (4) is an inner concave arc surface (41) and the other side of the support bar (4) is an outer convex arc surface (42). When the support bar (4) is tightly arranged between the core column (23) and the low-voltage coil (31), the inner concave arc surface (41) of the support bar (4) and the outer cylindrical surface of the core column (23) are in surface-to-surface contact, and the outer convex arc surface (42) of the support bar (4) and the inner cylindrical surface of the low-voltage coil (31) are in surface-to-surface contact. The upper end surface of the support bar (4) is provided with a through hole (43), and the through hole (43) passes through the upper and lower end surfaces of the support bar (4).

3. A novel offshore special dry-type transformer according to claim 1 or 2, characterized in that: The high-voltage coil (32) comprises a first coil layer (321), a second coil layer (322), a third coil layer (323), a first air duct (324) and a second air duct (325); the second coil layer (322) is arranged outside the first coil layer (321), and the third coil layer (323) is arranged outside the second coil layer (322); a first air duct (324) is formed between the first coil layer (321) and the second coil layer (322) by arranging a plurality of support bars (326); and a second air duct (325) is formed between the second coil layer (322) and the third coil layer (323) by arranging a plurality of support bars (326).

4. A novel offshore special dry-type transformer according to claim 1 or 2, characterized in that: The low-voltage coil (31) and the high-voltage coil (32) are both cast with silicone rubber.

5. A novel offshore special dry-type transformer according to claim 1 or 2, characterized in that: Two rows of cooling fans (5) are provided on the base of the dry-type transformer body (1).

6. A novel offshore special dry-type transformer according to claim 1 or 2, characterized in that: The low-voltage coil (31) is formed by winding copper foil.

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