Dry-type transformer of Yd11 type connection group

Abstract

The utility model discloses a kind of Yd11 type joint group's dry-type transformer, including core, low voltage coil, high voltage coil, upper clamp, lower clamp, base, the winding direction of a phase coil and b phase coil of low voltage coil is same, the winding direction of c phase coil and a, b phase coil is opposite, and the head of a phase coil is connected with the tail of c phase coil through a-c joint row of straight row structure;The head of b phase coil is connected with the tail of a phase coil through b-a joint row, the head of c phase coil is connected with the tail of b phase coil through c-b joint row;Transformer further includes side edge centrifugal fan being arranged at its two sides and bottom centrifugal fan being arranged in the supporting space between base and lower clamp, air outlet of bottom centrifugal fan is connected with air guide pipe, air guide pipe extends to the interphase area between high voltage coil and low voltage coil. The overall scheme realizes the simplification of processing technology, the optimization of heat dissipation performance and the comprehensive improvement of running stability.

Description

Technical Field

[0001] This utility model relates to a dry-type transformer, and more particularly to a dry-type transformer with a Yd11 connection group. Background Technology

[0002] In existing dry-type transformers of the Yd11 type connection group, such as Figure 4 As shown, the low-voltage D-type connection method requires the transformer's a-head and c-tail connection bar to be bent at multiple right angles, which directly leads to high processing difficulty and inconvenient installation.

[0003] Meanwhile, the existing Yd11 type dry-type transformers use a method where the airflow direction is parallel to the core column to facilitate airflow into the interphase coils. However, the transformer has high internal air resistance and uneven heat dissipation. In the parts shielded by the yoke, the high internal air resistance makes it difficult for cooling air to enter, resulting in significant differences in cooling air velocity across the windings. In particular, the interphase positions of the transformer have very poor heat dissipation, leading to excessively high hot spot temperatures at the air outlet end of the windings, while other areas have excessive temperature margins. This affects the product's economy and reliability, and restricts further improvement in transformer performance. Utility Model Content

[0004] To address the shortcomings of the aforementioned technologies, this utility model provides a dry-type transformer with a Yd11 connection group.

[0005] To solve the above technical problems, the technical solution adopted by this utility model is: a dry-type transformer with a Yd11 connection group, including an iron core, a low-voltage coil and a high-voltage coil mounted on the iron core core column, an upper clamp and a lower clamp clamped on the fixed iron core, and a base installed below the lower clamp. The low-voltage coil includes an a-phase coil, a b-phase coil, and a c-phase coil. The a-phase coil and the b-phase coil have the same winding direction, while the c-phase coil has the opposite winding direction to the a-phase and b-phase coils. The beginning of the a-phase coil is connected to the end of the c-phase coil via a straight-line ac connection group. The beginning of the b-phase coil is connected to the end of the a-phase coil via a ba connection group, and the beginning of the c-phase coil is connected to the end of the b-phase coil via a CB connection group. The transformer also includes side centrifugal fans on both sides and bottom centrifugal fans in the support space between the base and the lower clamp. The air outlet of the bottom centrifugal fan is connected to a duct, which extends to the phase-to-phase area between the high-voltage coil and the low-voltage coil.

[0006] Furthermore, both phase a and phase b coils are wound in the left direction, while phase c coil is wound in the right direction.

[0007] Furthermore, it also includes high-voltage insulators and low-voltage insulators. The high-voltage insulators are fixedly installed on the upper clamp, and one end of the high-voltage insulator is connected to the high-voltage output busbar, which is connected to the line end or tap of the high-voltage coil. The low-voltage insulators are fixedly installed on the upper clamp or transformer shell to support and insulate the low-voltage side output busbar.

[0008] Furthermore, it also includes a high-voltage Y-connection busbar and a high-voltage tap changer busbar. The high-voltage Y-connection busbar connects the tail ends of the three phases of the high-voltage coil to form a neutral point, thereby achieving a Y-shaped connection on the high-voltage side. The high-voltage tap changer busbar is installed on the side of the high-voltage coil and directly connected to the taps leading out from the high-voltage coil.

[0009] Furthermore, it also includes an upper pad and a lower pad, with the upper pad located between the upper end face of the low-voltage coil and the high-voltage coil and the upper clamp, and the lower pad located between the lower end face of the low-voltage coil and the high-voltage coil and the lower clamp.

[0010] Furthermore, the air duct is an insulated flexible air duct with an orifice diameter of 20mm.

[0011] This invention provides a dry-type transformer with a Yd11 connection group. By setting the c-phase coil to have the opposite winding direction to phases a and b, the beginning of phase a and the end of phase c are naturally aligned in space. Through a straight-line connection, it fundamentally solves the problems of high processing difficulty and inconvenient installation caused by multiple right-angle bends in the low-voltage side ac connection of traditional Yd11 transformers, significantly reducing production costs and improving connection reliability. Simultaneously, by employing a synergistic cooling system consisting of a side fan and a bottom-mounted fan with ductwork, airflow is precisely directed to the high-resistance, overheat-prone interphase areas, effectively overcoming the problems of uneven internal heat dissipation and excessively high local hot spot temperatures, thus improving the transformer's heat dissipation efficiency and operational reliability. Overall, this solution achieves a comprehensive improvement in processing technology, heat dissipation performance, and operational stability. Attached Figure Description

[0012] Figure 1 A schematic diagram of the three-view structure of a transformer according to an embodiment of a novel utility model patent is shown; Figure 2 A schematic diagram of the front view of a transformer according to an embodiment of a new utility model patent is shown; Figure 3 A top view schematic diagram of a transformer provided according to an embodiment of a novel utility model patent is shown; Figure 4 This diagram illustrates that the low-voltage D-type connection requires two right-angle turns when connecting the a-head and c-tail joints. Figure 5 A schematic diagram of a transformer D-type connection group provided according to an embodiment of a new utility model patent is shown; In the diagram: 1. Phase a coil; 2. Phase b coil; 3. Phase c coil; 4. Upper clamp; 5. Low-voltage coil; 6. High-voltage coil; 7. Side centrifugal fan; 8. Base; 9. Core; 10. High-voltage insulator; 11. BA connecting bar; 12. CB connecting bar; 13. AC connecting bar; 14. Lower clamp; 15. High-voltage outgoing line bar; 16. Low-voltage insulator; 17. High-voltage Y-connection connecting bar; 18. High-voltage tap joint connecting bar; 19. Lower pad; 20. Upper pad; 22. Bottom centrifugal fan. Detailed Implementation

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1-3 As shown, this embodiment discloses a Yd11 type connection group dry-type transformer, including a core 9, a low-voltage coil 5 and a high-voltage coil 6 mounted on the core column of the core 9, an upper clamp 4 and a lower clamp 14 clamping the core 9, and a base 8 installed below the lower clamp 14. The low-voltage coil 5 includes an a-phase coil 1, a b-phase coil 2, and a c-phase coil 3. The winding directions of the a-phase coil 1 and the b-phase coil 2 are the same. Further combined with... Figure 5 As shown, the winding direction of phase bc coil 3 is opposite to that of phase a and b coils. In this embodiment, phase a coil 1 and phase b coil 2 are both wound to the left, while phase c coil 3 is wound to the right. The beginning of phase a coil and the end of phase c coil are connected by a straight-line ac connection row 13; that is, a straight-line connection, without any complex right-angle bends. Traditionally, the winding direction is the same. In order to meet the phase requirements of D wiring, a large bend must be made in the physical connection to achieve the crossing. In this embodiment, by changing the winding direction of phase c, the direction of phase c voltage vector is directly changed at the electromagnetic level. This makes it possible for the beginning of phase a and the end of phase c of the output terminal that meet the correct phase relationship to be naturally aligned in a straight line in space during physical connection. The beginning of phase b coil and the end of phase a coil are connected by a ba connection row 11, and the beginning of phase c coil and the end of phase b coil are connected by a CB connection row 12. This makes the overall processing technology simpler and the cost significantly reduced.

[0015] The transformer also includes side centrifugal fans 7 located on both sides and a bottom centrifugal fan 22 located in the support space between the base 8 and the lower clamp 14. The outlet of the bottom centrifugal fan 22 is connected to a duct, which extends to the phase-interval area between the high-voltage coil 6 and the low-voltage coil 5. The duct is an insulated flexible air duct with a diameter of 20mm. This part achieves zoned and directional cooling. By establishing a three-dimensional cooling scheme, the side fans sweep over a large area on the outside of the transformer, solving the problem of heat dissipation in the side dead corners; the bottom fan, located in the support space, forms a ring-shaped air chamber, generating a uniform upward main cooling airflow. The flexible air duct is led out from the bottom fan, with its outlet directly aimed at the phase-interval area between the high-voltage and low-voltage coils. This is the area with the greatest air resistance and the easiest heat accumulation inside the entire transformer; the cooling airflow is forcibly injected into the most needed area.

[0016] The dry-type transformer also includes a high-voltage insulator 10 and a low-voltage insulator 16. The high-voltage insulator 10 is fixedly installed on the upper clamp 4, and one end of the high-voltage insulator 10 is connected to the high-voltage output busbar 15. The high-voltage output busbar 15 is connected to the line end or tap of the high-voltage coil 6. The low-voltage insulator 16 is fixedly installed on the upper clamp 4 or the transformer casing to support and insulate the low-voltage side output busbar. The dry-type transformer also includes an upper pad 20 and a lower pad 19. The upper pad 20 is located between the upper end face of the low-voltage coil 5 and the high-voltage coil 6 and the upper clamp 4, and the lower pad 19 is located between the lower end face of the low-voltage coil 5 and the high-voltage coil 6 and the lower clamp 14. The insulators and pads together form a robust insulation system, which helps to prevent short circuits to ground and phase-to-phase short circuits.

[0017] The dry-type transformer also includes a high-voltage Y-connection busbar 17 and a high-voltage tap changer busbar 18. The high-voltage Y-connection busbar 17 connects the tail ends of the three phases of the high-voltage coil 6 to form a neutral point, thus achieving a Y-shaped connection on the high-voltage side. The high-voltage tap changer busbar 18 is installed on the side of the high-voltage coil 6 and directly connected to the taps led out from the high-voltage coil 6. The high-voltage Y-connection busbar 17 enables a standard high-voltage side Y-shaped (star) connection, with the transformer connection group being Yd11, where "Y" indicates that the high-voltage side windings need to be connected in a star configuration. The star connection requires connecting the tail ends or head ends of phases A, B, and C of the three-phase coil together to form a common neutral point, which is achieved through the high-voltage Y-connection busbar. The high-voltage tap changer busbar 18 provides an adjustable voltage transformation ratio to adapt to different grid voltages. Since the grid voltage is not constant and fluctuates within a certain range, this embodiment ensures that the transformer output voltage remains stable at the rated value, requiring the ability to fine-tune its transformation ratio, hence the taps led out from the high-voltage coil.

[0018] In summary, this patent fundamentally solves the problems of high processing difficulty and inconvenient installation caused by the need for multiple right-angle bends in the AC connection bar on the low-voltage side of the traditional Yd11 transformer, by setting the C-phase coil to have the winding direction opposite to that of the A and B phases, so that the beginning of the A-phase and the end of the C-phase are naturally aligned in space, and by connecting them in a straight line. This significantly reduces production costs and improves connection reliability. At the same time, by adopting a synergistic cooling system consisting of a side fan and a bottom fan with a duct, the airflow is precisely directed to the interphase area with high wind resistance and prone to overheating, effectively overcoming the problems of uneven internal heat dissipation and excessively high local hot spot temperatures, thus improving the transformer's heat dissipation efficiency and operational reliability. Overall, this solution achieves a comprehensive improvement in processing technology, heat dissipation performance, and operational stability.

[0019] The above embodiments are not intended to limit the present utility model, nor is the present utility model limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the technical solution of the present utility model are also within the protection scope of the present utility model.

Claims

1. A dry-type transformer with a Yd11 connection group, characterized in that: The device includes an iron core (9), a low-voltage coil (5) and a high-voltage coil (6) mounted on the core column of the iron core (9), an upper clamp (4) and a lower clamp (14) clamped to the fixed iron core (9), and a base (8) installed below the lower clamp (14). The device is characterized in that: the low-voltage coil (5) includes an a-phase coil (1), a b-phase coil (2) and a c-phase coil (3). The winding directions of the a-phase coil (1) and the b-phase coil (2) are the same, and the winding directions of the c-phase coil (3) are opposite to those of the a-phase and b-phase coils. The beginning of the a-phase coil is connected to the end of the c-phase coil through a straight-line ac connecting block (13). The beginning of the b-phase coil is connected to the end of the a-phase coil through a ba connecting block (11), and the beginning of the c-phase coil is connected to the end of the b-phase coil through a cb connecting block (12). The transformer also includes side centrifugal fans (7) on both sides and bottom centrifugal fans (22) in the support space between the base (8) and the lower clamp (14). The air outlet of the bottom centrifugal fan (22) is connected to a guide pipe, which extends to the phase-to-phase area between the high-voltage coil (6) and the low-voltage coil (5).

2. The dry-type transformer of the Yd11 type connection group according to claim 1, characterized in that: The a-phase coil (1) and the b-phase coil (2) are both wound in the left direction, and the c-phase coil (3) is wound in the right direction.

3. The dry-type transformer of the Yd11 type connection group according to claim 1, characterized in that: It also includes a high-voltage insulator (10) and a low-voltage insulator (16). The high-voltage insulator (10) is fixedly installed on the upper clamp (4). One end of the high-voltage insulator (10) is connected to the high-voltage output busbar (15). The high-voltage output busbar (15) is connected to the wire end or tap of the high-voltage coil (6). The low-voltage insulator (16) is fixedly installed on the upper clamp (4) or the transformer shell to support and insulate the low-voltage side output busbar.

4. The dry-type transformer of the Yd11 type connection group according to claim 1, characterized in that: It also includes a high-voltage Y-connection busbar (17) and a high-voltage tap connection busbar (18). The high-voltage Y-connection busbar (17) connects the tail ends of the three phases of the high-voltage coil (6) to form a neutral point to achieve a Y-shaped connection on the high-voltage side. The high-voltage tap connection busbar (18) is installed on the side of the high-voltage coil (6) and directly connected to the taps led out from the high-voltage coil (6).

5. The dry-type transformer of the Yd11 type connection group according to claim 1, characterized in that: It also includes an upper pad (20) and a lower pad (19). The upper pad (20) is located between the upper end face of the low-voltage coil (5) and the high-voltage coil (6) and the upper clamp (4). The lower pad (19) is located between the lower end face of the low-voltage coil (5) and the high-voltage coil (6) and the lower clamp (14).

6. The dry-type transformer of the Yd11 type connection group according to any one of claims 2-5, characterized in that: The air duct is an insulated flexible air duct with a diameter of 20mm.

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