A 110kV dry-type transformer

Abstract

The utility model discloses a kind of 110kV dry-type transformers, including three single-phase dry-type transformers connected, each single-phase dry-type transformer includes high voltage coil, low voltage coil and iron core;The high voltage coil is sleeved outside low voltage coil, and low voltage coil is sleeved outside the iron core column of iron core;Each single-phase dry-type transformer, in the incoming line side of high voltage coil, the upper and lower ends of high voltage coil and low voltage coil, between the air insulation of upper and lower iron yoke of iron core, respectively be provided with one or more insulating baffle for reducing the insulation interval distance of single air insulation.The 110kV dry-type transformer provided in the application, in the air between high voltage coil and upper and lower iron yoke in incoming line side, insulating baffle is arranged, on the one hand, the lightning impulse insulation level of high voltage coil to ground can be promoted, on the other hand, the height size of large-capacity dry-type transformer can be reduced, to meet the height limit requirement of automobile transportation.

Description

Technical Field

[0001] This utility model patent relates to the field of power transformer technology, specifically to a 110kV dry-type transformer. Background Technology

[0002] In the current technical system of 110kV dry-type transformers, air is used as the cooling medium and external insulation medium for the high-voltage coil, low-voltage coil, and core. Although this design has certain advantages in terms of safety and ease of maintenance, compared with the traditional structure that uses transformer insulating oil as the insulation medium, air has a significant shortcoming in electrical breakdown strength - its electrical breakdown strength is only more than 1 / 10 of that of transformer insulating oil.

[0003] Due to the relatively weak air insulation properties, to meet the insulation requirements of 110kV dry-type transformers, it is necessary to increase the height of the high-voltage coil and the low-voltage coil to ensure sufficient air insulation spacing and achieve the required insulation level. With the increasing demand for electricity, the application of large-capacity 110kV dry-type transformers (rated capacity typically covering 6300kVA to 20000kVA) is becoming increasingly widespread. Because of the increased coil height, the overall equipment height of these transformers is also increased, easily exceeding the 4.3m height limit stipulated for first-class highway transportation. Exceeding the transportation height limit significantly increases the difficulty of transporting 110kV dry-type transformers. This not only requires additional special transportation routes and specialized transportation equipment, but may also increase transportation costs, extend transportation time, and even lead to transportation route restrictions in some areas, severely hindering the promotion, application, and engineering implementation of large-capacity 110kV dry-type transformers.

[0004] Therefore, how to control and reduce the overall height of the equipment by optimizing technical solutions to solve the problem of excessive transportation height of large-capacity 110kV dry-type transformers while ensuring the insulation performance of 110kV dry-type transformers (especially the lightning impulse insulation level of the high-voltage coil and low-voltage coil to ground) has become a key direction that urgently needs to be broken through in the field of power transformer technology. Utility Model Content

[0005] The purpose of this utility model is to provide a 110kV dry-type transformer to solve the problem that the existing large-capacity 110kV dry-type transformers are too large in overall size and easily exceed the 4.3m transportation height limit of first-class highways.

[0006] To achieve the objectives of this utility model, the technical solution provided by this utility model is as follows:

[0007] A 110kV dry-type transformer includes three connected single-phase dry-type transformers, each of which includes 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] In each single-phase dry-type transformer, the high-voltage coil, low-voltage coil, and core columns are arranged opposite each other. One side is the incoming side of the high-voltage coil, which includes the incoming terminals A (B, C) of the high-voltage coil, and the incoming terminals are located in the middle of the high-voltage coil. The other side is the outgoing side of the high-voltage coil, which includes the outgoing terminals N (X, Y, Z) of the high-voltage coil, and the outgoing terminals are located at the ends of the high-voltage coil.

[0009] Each single-phase dry-type transformer has one or more insulating partitions in the air insulation between the high-voltage coil input side, the upper and lower ends of the high-voltage coil and the low-voltage coil, and the upper and lower yokes of the core, to reduce the distance between individual air insulation gaps.

[0010] The high-voltage coils of the three single-phase dry-type transformers 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. The low-voltage coils of the three single-phase dry-type transformers 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.

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

[0012] Furthermore, the single-phase dry-type transformer has an insulating cylinder between the high-voltage coil and the low-voltage coil to improve the withstand voltage insulation level between the high-voltage coil and the low-voltage coil.

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

[0014] Furthermore, the single-phase dry-type transformer has a high-voltage coil partition between the high-voltage coil on the incoming side and the high-voltage coil on the outgoing side.

[0015] Furthermore, the high-voltage coil separator is made of insulating glass fiber reinforced epoxy resin sheet with a thickness of 3-5mm.

[0016] Furthermore, the single-phase dry-type transformer has a corona-resistant insulating varnish coated on the outer surface of the high-voltage coil.

[0017] Furthermore, the corona-resistant insulating varnish is an RTV-room temperature-curing silicone rubber insulating varnish with a coating thickness of 150–250 μm.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] (1) The 110kV dry-type transformer provided in this application has an insulating partition installed in the air between the high-voltage coil and the upper and lower yokes on the incoming line side. On the one hand, this can improve the lightning impulse insulation level of the high-voltage coil to the ground, and on the other hand, it can reduce the height of the large-capacity dry-type transformer to meet the height restriction requirements for automobile transportation.

[0020] (2) The solution provided in this application has an insulating cylinder between the high voltage coil and the low voltage coil, which can improve the voltage withstand insulation level between the high voltage coil and the low voltage coil.

[0021] (3) The solution provided in this application has a high-voltage coil partition between the high-voltage coil on the incoming side and the high-voltage coil on the outgoing side, which can reduce the distance between the high-voltage coils;

[0022] (4) The solution provided in this application coats the outer surface of the high-voltage coil with corona-resistant insulating varnish to improve the insulation ability of the high-voltage coil to withstand polluted environment and humid air. Attached Figure Description

[0023] Figure 1 A schematic diagram of the single-phase transformer configuration of a 110kV dry-type transformer provided in an embodiment of this application;

[0024] Figure 2 A schematic diagram of the three-phase high-voltage winding connection of a 110kV dry-type transformer provided in an embodiment of this application;

[0025] Figure 3 A schematic diagram of a three-phase low-voltage winding connection of a 110kV dry-type transformer provided in an embodiment of this application;

[0026] Figure 4 This is a planar shape diagram of the insulating partition provided in an embodiment of this application.

[0027] Icons: 1-Single-phase dry-type transformer; 11-High-voltage coil; 12-Low-voltage coil; 13-Core; 14-Insulating partition; 15-Insulating cylinder; 16-High-voltage coil partition; 17-Support pad. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] like 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 this invention, 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 withstand voltage 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 this invention, the single-phase dry-type transformer 1 has a high-voltage coil separator 16 provided between the high-voltage coil 11 on the input side and the high-voltage coil 11 on the output side, which can reduce the distance between the high-voltage coils 11. The high-voltage coil separator 16 can be made of insulating glass fiber reinforced epoxy resin sheet with a thickness of 3-5 mm.

[0037] In an optional embodiment of this invention, the single-phase dry-type transformer 1 has a corona-resistant insulating varnish coated on the outer surface of the high-voltage coil 11 to improve the insulation capability of the high-voltage coil 11 against polluted environments and humid air. One type of corona-resistant insulating varnish is an RTV-room temperature-curing silicone rubber insulating varnish, with a coating thickness of 150–250 μm.

[0038] Finally, it should be noted that the above embodiments are merely examples and illustrations of the present invention, and are not intended to limit the present invention to the scope of the described embodiments. Furthermore, those skilled in the art will understand that the present invention is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of the present invention, all of which fall within the scope of protection claimed by the present invention.

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 (12), 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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