110kV dry-type transformer

Abstract

The 110kV dry-type transformer comprises three connected single-phase dry-type transformers, and each single-phase dry-type transformer comprises a high-voltage coil, a low-voltage coil and an iron core; the high-voltage coil is sleeved outside the low-voltage coil, and the low-voltage coil is sleeved outside an iron core column of the iron core; according to each single-phase dry-type transformer, one or more insulating partition plates used for reducing the spacing distance of single air insulators are arranged on the wire inlet side of the high-voltage coil, the upper ends and the lower ends of the high-voltage coil and the low-voltage coil and in the air insulators between the upper iron yoke and the lower iron yoke of the iron core respectively. According to the 110kV dry-type transformer provided by the invention, the insulating partition plates are arranged in the air among the wire inlet side, the high-voltage coil, the upper iron yoke and the lower iron yoke, on one hand, the lightning impulse insulation level of the high-voltage coil to the ground can be improved, on the other hand, the height size of the high-capacity dry-type transformer can be reduced, and the height limiting requirement of automobile transportation can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power transformers, in particular to a 110kV dry-type transformer. BACKGROUND

[0002] In the current technical system of 110kV dry-type transformers, air is the cooling medium and external insulating medium commonly used by high-voltage coils, low-voltage coils and iron cores. Although this design has certain advantages in safety and maintenance convenience, compared with the structure using transformer insulating oil as the insulating medium, the air has a significant shortcoming in electric breakdown strength, which is only 1 / 10 or more of the electric breakdown strength of transformer insulating oil.

[0003] Due to the weak insulation performance of air, in order to meet the insulation requirements of 110kV dry-type transformers, it is necessary to increase the height of high-voltage coils and low-voltage coils to ensure sufficient air insulation spacing to achieve the required insulation level. With the growth of power demand, large-capacity 110kV dry-type transformers (with a rated capacity usually covering 6300kVA-20000kVA) are increasingly widely used. Due to the increase in coil height, the overall equipment height of such transformers is increased, which is likely to exceed the 4.3m height limit specified by the first-class highway transportation. The height overrun of the transportation will greatly increase the transportation difficulty of 110kV dry-type transformers, not only requiring additional planning of special transportation routes and the use of special transportation equipment, but also possibly increasing transportation costs, prolonging transportation cycles, and even facing transportation path limitations in some areas, which seriously restricts the promotion and application of large-capacity 110kV dry-type transformers.

[0004] Therefore, how to ensure the insulation performance of 110kV dry-type transformers (especially the lightning impulse insulation level of high-voltage coils and low-voltage coils to ground) while optimizing the technical solution to control and reduce the overall height of the equipment and solve the problem of height overrun of large-capacity 110kV dry-type transformers has become a key direction that needs to be broken through in the current power transformer technical field. SUMMARY

[0005] The purpose of the present application is to provide a 110kV dry-type transformer to solve the problem of high overall size of existing large-capacity 110kV dry-type transformers, which easily exceeds the 4.3m height limit of first-class highway transportation.

[0006] To achieve the purpose of the present application, the technical solution provided by the present application is as follows:

[0007] A 110kV dry-type transformer, comprising three single-phase dry-type transformers connected in series, each single-phase dry-type transformer comprising a high-voltage coil, a low-voltage coil and an iron core; the high-voltage coil is sleeved outside the low-voltage coil, and the low-voltage coil is sleeved outside the iron core column of the iron core;

[0008] The high-voltage coil, the low-voltage coil and the core column of the core of each single-phase dry-type transformer are oppositely arranged, one side is the incoming line side of the high-voltage coil, contains the incoming line terminal A (B, C) of the high-voltage coil, and the incoming line terminal is arranged at the middle part of the high-voltage coil; the other side is the outgoing line side of the high-voltage coil, contains the outgoing line terminal N (X, Y, Z) of the high-voltage coil, and the outgoing line terminal is arranged at the end part of the high-voltage coil.

[0009] In each single-phase dry-type transformer, one or more insulation partitions for reducing the spacing distance of single air insulation are arranged in the air insulation between the incoming line side of the high-voltage coil, the upper and lower ends of the high-voltage coil and the low-voltage coil and the upper and lower yokes of the core.

[0010] The high-voltage coils of the three single-phase dry-type transformers are connected into a three-phase high-voltage winding, which is the primary side of the three-phase transformer, corresponding to phase A, phase B and phase C; the low-voltage coils of the three single-phase dry-type transformers are connected into a three-phase low-voltage winding, which is the secondary side of the three-phase transformer, corresponding to phase a, phase b and phase c.

[0011] Further, the insulation partition is an insulated glass fiber reinforced epoxy resin sheet with a thickness of 3-5 mm.

[0012] Further, the single-phase dry-type transformer is provided with an insulation cylinder between the high-voltage coil and the low-voltage coil for improving the withstand voltage insulation level between the high-voltage coil and the low-voltage coil.

[0013] Further, the insulation cylinder is an insulated glass fiber reinforced epoxy resin thin cylinder with a cylinder wall thickness of 3-5 mm.

[0014] Further, the single-phase dry-type transformer is provided with a high-voltage coil partition between the incoming line side high-voltage coil and the outgoing line side high-voltage coil.

[0015] Further, the high-voltage coil partition is selected from an insulated glass fiber reinforced epoxy resin sheet with a thickness of 3-5 mm.

[0016] Further, the single-phase dry-type transformer is coated with a corona-resistant insulation paint on the outer surface of the high-voltage coil.

[0017] Further, the corona-resistant insulation paint is RTV-room temperature curing silicone rubber insulation paint with a coating thickness of 150-250 μm.

[0018] Compared with the prior art, the beneficial effects of the present application are as follows:

[0019] (1) The 110kV dry-type transformer provided in the application is provided with an insulation partition plate in the air between the high-voltage coil and the upper and lower iron yokes on the incoming line side, which can improve the lightning impulse insulation level of the high-voltage coil to the ground and reduce the height of the large-capacity dry-type transformer to meet the height limit requirement of automobile transportation.

[0020] (2) The scheme provided in the application is provided with an insulation cylinder between the high-voltage coil and the low-voltage coil, which can improve the withstand voltage insulation level between the high-voltage coil and the low-voltage coil.

[0021] (3) The scheme provided in the application is provided with a high-voltage coil partition plate between the high-voltage coil on the incoming line side and the high-voltage coil on the outgoing line side, which can reduce the distance between the high-voltage coils.

[0022] (4) The scheme provided in the application is that the outer surface of the high-voltage coil is coated with a corona-resistant insulating paint to improve the insulation capacity of the high-voltage coil in a polluted environment and humid air. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The single-phase transformer of the 110kV dry-type transformer provided in the embodiment of the application is shown in the schematic diagram.

[0024] Figure 2 The three-phase high-voltage winding connection schematic diagram of the 110kV dry-type transformer provided in the embodiment of the application is shown in the schematic diagram.

[0025] Figure 3 The three-phase low-voltage winding connection schematic diagram of the 110kV dry-type transformer provided in the embodiment of the application is shown in the schematic diagram.

[0026] Figure 4 The planar shape diagram of the insulation partition plate provided in the embodiment of the application is shown in the schematic diagram.

[0027] Figure legend: 1-single-phase dry-type transformer; 11-high-voltage coil; 12-low-voltage coil; 13-iron core; 14-insulation partition plate; 15-insulation cylinder; 16-high-voltage coil partition plate; 17-supporting cushion block. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0029] For example, Figure 1As shown, this embodiment provides a 110kV dry-type transformer, which includes three connected single-phase dry-type transformers 1. Each single-phase dry-type transformer 1 includes a high-voltage coil 11, a low-voltage coil 12, and an iron core 13. The high-voltage coil 11 is sleeved outside the low-voltage coil 12, and the low-voltage coil 12 is sleeved outside the iron core column of the iron core 13.

[0030] Each single-phase dry-type transformer 1 has its high-voltage coil 11, low-voltage coil 11, and core column 13 arranged opposite to each other. One side is the input side of the high-voltage coil, including the input terminals A (B, C) of the high-voltage coil, which are located in the middle of the high-voltage coil. The other side is the output side of the high-voltage coil, including the output terminals N (X, Y, Z) of the high-voltage coil, which are located at the end of the high-voltage coil.

[0031] Each single-phase dry-type transformer 1 is provided with one or more insulating partitions 14 in the air insulation between the high-voltage coil 11 (inlet side), the upper and lower ends of the high-voltage coil 11 and the low-voltage coil 12, and the upper and lower yokes of the core 13. These partitions are positioned and fixed to the core 13 by insulating supports (not shown in the figure) to isolate the air insulation between the high-voltage coil 11 and the upper and lower yokes of the core 13, and to reduce the distance between individual air insulation gaps (which can be 50-100mm), thereby improving the lightning impulse insulation level of the high-voltage coil 11. The insulating partition 14 can be an insulating glass fiber reinforced epoxy resin sheet with a thickness of 3-5mm, and the surface shape of the insulating partition 14 can be as follows: Figure 4 As shown.

[0032] Each single-phase dry-type transformer 1 has an insulated support block 17, which serves to position and fix components such as the high-voltage coil 11, the low-voltage coil 12, and the insulating partition 14. Figure 1 In the middle, for the sake of clarity, the four support pads 17 above and below the high voltage coil 11 and the low voltage coil 12 on the incoming line side are not shown.

[0033] The high-voltage coils 11 of the three single-phase dry-type transformers 1 are connected to form a three-phase high-voltage winding, which is the primary side of the three-phase transformer, corresponding to phases A, B, and C, as follows. Figure 2 As shown. The low-voltage coils 12 of the three single-phase dry-type transformers 1 are connected to form a three-phase low-voltage winding, which is the secondary side of the three-phase transformer, corresponding to phases a, b, and c, as follows. Figure 3 As shown.

[0034] The 110kV dry-type transformer designed in the above scheme has an insulating partition 14 installed in the air between the upper and lower yokes of the high-voltage coil 11 and the core 13 on the incoming side of each single-phase transformer 1. This can improve the insulation level of the high-voltage coil 11 against ground lightning impulses and reduce the height of the large-capacity dry-type transformer to meet the height restriction requirements for automobile transportation.

[0035] In an optional embodiment of the present application, the single-phase dry-type transformer 1 is provided with an insulating cylinder 15 between the high-voltage coil 11 and the low-voltage coil 12, which can improve the insulation level between the high-voltage coil 11 and the low-voltage coil 12. The insulating cylinder 15 can be an insulating glass fiber reinforced epoxy resin thin cylinder with a wall thickness of 3-5 mm.

[0036] In an optional embodiment of the present application, the single-phase dry-type transformer 1 is provided with a high-voltage coil partition 16 between the incoming high-voltage coil 11 and the outgoing high-voltage coil 11, which can reduce the distance between the high-voltage coils 11. The high-voltage coil partition 16 can be an insulating glass fiber reinforced epoxy resin thin plate with a thickness of 3-5 mm.

[0037] In an optional embodiment of the present application, the single-phase dry-type transformer 1 is coated with a corona-resistant insulating paint on the outer surface of the high-voltage coil 11, which improves the insulation capability of the high-voltage coil 11 to withstand contaminated environments and humid air. A kind of corona-resistant insulating paint is RTV-room temperature curing silicone rubber insulating paint, and the coating thickness is 150-250 μm.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate and describe the present application, and are not intended to limit the present application to the scope of the described embodiments. In addition, those skilled in the art can understand that the present application is not limited to the above embodiments, and more variants and modifications can be made according to the teaching of the present application, which all fall within the scope of the present application.

Claims

1. A 110kV dry-type transformer, characterized in that, The system includes three connected single-phase dry-type transformers (1), each of which includes a high-voltage coil (11), a low-voltage coil (12), and an iron core (13); the high-voltage coil (11) is sleeved outside the low-voltage coil (12), and the low-voltage coil (12) is sleeved outside the iron core column of the iron core (13); The high-voltage coil (11), low-voltage coil (11), and core column (13) of each single-phase dry-type transformer (1) are arranged opposite to each other. One side is the input side of the high-voltage coil (11), which includes the input terminal of the high-voltage coil and is located in the middle of the high-voltage coil. The other side is the output side of the high-voltage coil (11), which includes the output terminal of the high-voltage coil (11) and is located at the end of the high-voltage coil (11). Each single-phase dry-type transformer (1) has one or more insulating partitions (14) in the air insulation between the high-voltage coil (11) and the upper and lower ends of the high-voltage coil (11) and the low-voltage coil (12) and the upper and lower yokes of the core (13) to reduce the distance between individual air insulation gaps. The high-voltage coils (11) of the three single-phase dry-type transformers (1) are connected to form a three-phase high-voltage winding, which is the primary side of the three-phase transformer, corresponding to phase A, phase B and phase C. The low-voltage coils (12) of the three single-phase dry-type transformers (1) are connected to form a three-phase low-voltage winding, which is the secondary side of the three-phase transformer, corresponding to phase a, phase b and phase c.

2. A 110kV dry-type transformer according to claim 1, characterized in that, The insulating partition is an insulating glass fiber reinforced epoxy resin sheet with a thickness of 3-5 mm.

3. A 110kV dry-type transformer according to claim 1, characterized in that, The single-phase dry-type transformer (1) has an insulating cylinder (15) between the high-voltage coil (11) and the low-voltage coil (12) to improve the withstand voltage insulation level between the high-voltage coil (11) and the low-voltage coil (12).

4. A 110kV dry-type transformer according to claim 3, characterized in that, The insulating cylinder (15) is an insulating glass fiber reinforced epoxy resin thin cylinder with a wall thickness of 3-5mm.

5. A 110kV dry-type transformer according to claim 3, characterized in that, The single-phase dry-type transformer (1) has a high-voltage coil partition (16) between the high-voltage coil (11) on the incoming side and the high-voltage coil (11) on the outgoing side.

6. A 110kV dry-type transformer according to claim 5, characterized in that, The high-voltage coil separator (16) is made of insulating glass fiber reinforced epoxy resin sheet with a thickness of 3-5 mm.

7. A 110kV dry-type transformer according to claim 1, characterized in that, The single-phase dry-type transformer (1) has a corona-resistant insulating varnish applied to the outer surface of the high-voltage coil (11).

8. A 110kV dry-type transformer according to claim 7, characterized in that, The corona-resistant insulating varnish is an RTV-room temperature-curing silicone rubber insulating varnish with a coating thickness of 150–250 μm.

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