A three-phase three-winding dry-type transformer

Abstract

This invention relates to the field of dry-type transformer technology, and particularly to a three-phase, three-winding dry-type transformer comprising: an upper pressure plate and a lower pressure plate, wherein three iron cores are disposed between the upper pressure plate and the lower pressure plate; a first-phase winding, a second-phase winding, and a third-phase winding are sequentially disposed on the three iron cores, wherein the first-phase winding, the second-phase winding, and the third-phase winding have identical structures; a fan disposed on the upper surface of the lower pressure plate; and a heat dissipation mechanism disposed inside the first-phase winding, the second-phase winding, and the third-phase winding, and connected to the fan, for introducing external cold air into the winding for heat dissipation.

Description

Technical Field

[0001] This invention relates to the field of dry-type transformer technology, and particularly to a three-phase, three-winding dry-type transformer. Background Technology

[0002] In the field of dry-type transformers, the three-phase, three-winding structure is a common form. In existing technology, a fan is usually installed on the lower pressure plate to blow air upwards to cool the windings, and ventilation openings are opened on the upper and lower pressure plates to form convection channels.

[0003] However, due to the three windings being arranged side-by-side, the second-phase winding, located in the middle, is adjacent to the first and third-phase windings on either side, limiting its heat dissipation space. Furthermore, the adjacent windings on both sides radiate heat to it, resulting in significantly worse natural convection conditions in the middle-phase winding compared to the two side windings. Actual operating data shows that the temperature rise of the middle-phase winding is often 10°C-15°C higher than that of the two side windings, becoming the thermal bottleneck of the entire transformer. Simultaneously, traditional air cooling methods only blow air onto the outside of the windings, failing to penetrate the interlayer gaps between the inner, middle, and outer windings, making it even more difficult to effectively remove heat from the interior of the middle-phase winding.

[0004] Therefore, a three-phase, three-winding dry-type transformer is needed to solve the above problems. Summary of the Invention

[0005] The main objective of this invention is to provide a three-phase, three-winding dry-type transformer, which aims to solve the problems of reducing the temperature rise of the intermediate phase winding and achieving temperature balance of the three-phase windings.

[0006] To achieve the above objectives, the technical solution proposed by this invention is: a three-phase, three-winding dry-type transformer, comprising: An upper pressure plate and a lower pressure plate, with three iron cores provided between the upper pressure plate and the lower pressure plate; The first phase winding, the second phase winding, and the third phase winding are sequentially arranged on the three iron cores, and the first phase winding, the second phase winding, and the third phase winding have the same structure. A fan is installed on the upper surface of the lower pressure plate; The heat dissipation mechanism is respectively disposed inside the first phase winding, the second phase winding and the third phase winding, and is connected to the fan to introduce external cold air into the winding for heat dissipation. Each phase winding includes an inner winding, an intermediate winding, and an outer winding wound sequentially from the inside out; The heat dissipation mechanism includes a first heat dissipation pipe and a second heat dissipation pipe. The first heat dissipation pipe passes between the outer winding and the intermediate winding, and the second heat dissipation pipe passes between the intermediate winding and the inner winding. The bottoms of both the first heat dissipation pipe and the second heat dissipation pipe are connected to the fan, the tops are sealed, and the sides are provided with heat dissipation vents.

[0007] Preferably, the heat dissipation mechanism further includes a heat dissipation component, which is disposed at the bottom between the outer winding and the intermediate winding and is connected to the first heat dissipation pipe to guide the air blown by the fan to the surface of the intermediate winding.

[0008] Preferably, the heat sink is an arc-shaped heat sink block, the arc-shaped surface of which is adapted to the shape of the outer surface of the intermediate winding, and an arc-shaped opening is provided above the arc-shaped heat sink block to guide airflow close to the surface of the intermediate winding.

[0009] Preferably, the upper pressure plate has a first vent, and the lower pressure plate has a second vent, the first vent and the second vent forming a convection heat dissipation channel.

[0010] Preferably, there are two first vents and two second vents, with the two first vents located between the first phase winding and the second phase winding, and between the second phase winding and the third phase winding, respectively; the positions of the two second vents correspond one-to-one with the positions of the two first vents.

[0011] Preferably, a partition is provided between the first phase winding and the second phase winding, and between the second phase winding and the third phase winding.

[0012] Preferably, the two partitions are arranged at an angle and are mirror images of each other, with the upper part of each partition close to the second phase winding; the lower side of the partition between the first and second phase windings is close to the first phase winding, and the lower side of the partition between the second and third phase windings is close to the third phase winding.

[0013] Preferably, there are multiple first heat dissipation pipes, which are distributed circumferentially between the outer winding and the intermediate winding; there are also multiple second heat dissipation pipes, which are distributed circumferentially between the intermediate winding and the inner winding.

[0014] Preferably, there are multiple heat dissipation vents, and the multiple heat dissipation vents are arranged along the axial direction of the pipe.

[0015] Preferably, the heat dissipation port is provided with a flow guiding edge.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: This invention overcomes the shortcomings of traditional external air cooling, which makes it difficult to enter the interior of the winding, by installing a first heat dissipation pipe and a second heat dissipation pipe between the outer winding and the middle winding, and between the middle winding and the inner winding of each phase winding, respectively, and connecting the bottom of the pipe to the fan, sealing the top, and opening heat dissipation vents on the side. This allows cold air to be directly and forcibly introduced into the interlayer gap where the heat generation is most severe and blown from the side to the winding surface, thus significantly improving the interlayer heat dissipation efficiency.

[0017] Building upon this, an arc-shaped heat sink is closely attached to the surface of the intermediate winding and features an arc-shaped opening. Combined with the guide edge on the heat sink, this further concentrates and directs airflow towards the winding surface, forming a high-speed air curtain and significantly enhancing local convective heat transfer. Simultaneously, vents positioned between phases on the upper and lower pressure plates, along with obliquely mirrored baffles, guide the rising cooling air towards the middle second-phase winding. This increases airflow distribution to the intermediate phase and reduces the impact of heat radiation from adjacent windings, effectively solving the technical challenges of excessively high intermediate phase temperature and uneven three-phase temperature. Multiple heat dissipation pipes are evenly distributed circumferentially, ensuring uniform circumferential cooling of the winding. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a diagram of the overall structure proposed in this invention; Figure 2 This is a front sectional view of the present invention; Figure 3 This is a top sectional view of the present invention; Figure 4 This is an enlarged view of point A in the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Upper pressure plate; 11. First vent; 2. Lower pressure plate; 21. Second vent; 3. Fan; 4. First phase winding; 41. Inner winding; 42. Intermediate winding; 43. Outer winding; 5. Partition; 61. First heat dissipation pipe; 611. Heat dissipation port; 62. Second heat dissipation pipe; 63. Heat dissipation component; 7. Iron core; 8. Second phase winding; 9. Third phase winding.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications in the embodiments of the present invention are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0024] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0027] Example 1 This invention proposes a three-phase, three-winding dry-type transformer.

[0028] As attached Figure 1 - Appendix Figure 4 As shown, a three-phase, three-winding dry-type transformer proposed in this invention includes: Upper pressure plate 1 and lower pressure plate 2, with three iron cores 7 provided between the upper pressure plate 1 and the lower pressure plate 2; The first phase winding 4, the second phase winding 8, and the third phase winding 9 are sequentially arranged on the three iron cores 7, and the first phase winding 4, the second phase winding 8, and the third phase winding 9 have the same structure. A fan is installed on the upper surface of the lower pressure plate 2; The heat dissipation mechanism is respectively disposed inside the first phase winding 4, the second phase winding 8 and the third phase winding 9, and is connected to the fan to introduce external cold air into the winding for heat dissipation. Each phase winding includes an inner winding 41, an intermediate winding 42, and an outer winding 43 wound sequentially from the inside to the outside. The heat dissipation mechanism includes a first heat dissipation pipe 61 and a second heat dissipation pipe 62. The first heat dissipation pipe 61 passes between the outer winding 43 and the intermediate winding 42, and the second heat dissipation pipe 62 passes between the intermediate winding 42 and the inner winding 41. The bottoms of the first heat dissipation pipe 61 and the second heat dissipation pipe 62 are connected to the fan, the tops are sealed, and the sides are provided with heat dissipation vents 611.

[0029] In this embodiment, the upper pressure plate 1 and the lower pressure plate 2 are typically made of metal materials such as steel plates or high-strength insulating boards, and are fixed by tie rods or bolts to clamp the iron core 7 and the windings. The iron core 7 is made of stacked silicon steel sheets and serves as the magnetic circuit of the transformer. The first phase winding 4, the second phase winding 8, and the third phase winding 9 are respectively mounted on the three iron cores 7 to form a three-phase circuit. Each phase winding adopts a three-winding structure with inner, middle, and outer windings, which can correspond to high-voltage, medium-voltage, and low-voltage windings, respectively. The specific voltage level can be set according to actual needs. The fan is preferably an axial flow fan, but it can also be replaced with a cooling fan according to actual needs. It is fixed on the front of the upper surface of the lower pressure plate 2, i.e., on the side closest to the operating surface. The fan outlet is connected to each heat dissipation pipe through a distribution duct or an air collection box. The core of the heat dissipation mechanism lies in the arrangement of pipes within the interlayer gaps of the windings. These pipes are sealed at the top and open at the sides, preventing the cold air supplied by the fan from being wasted by direct exhaust from the top. Instead, the air is forced to flow laterally from the side vents 611 towards the surface of the winding layers, achieving forced convection cooling. Compared to traditional methods that only blow air onto the outside of the windings, this solution directly introduces cold air into the interlayer area where heat generation is most severe, significantly improving heat dissipation efficiency. In practice, the first heat dissipation pipe 61 and the second heat dissipation pipe 62 can be made of insulating materials with good thermal conductivity, such as epoxy glass cloth tubing, ensuring both insulation strength and a certain degree of mechanical toughness.

[0030] This invention overcomes the shortcomings of traditional external air cooling, which makes it difficult to enter the interior of the winding, by installing a first heat dissipation pipe and a second heat dissipation pipe between the outer winding and the middle winding, and between the middle winding and the inner winding of each phase winding, respectively, and connecting the bottom of the pipe to the fan, sealing the top, and opening heat dissipation vents on the side. This allows cold air to be directly and forcibly introduced into the interlayer gap where the heat generation is most severe and blown from the side to the winding surface, thus significantly improving the interlayer heat dissipation efficiency.

[0031] Building upon this, an arc-shaped heat sink is closely attached to the surface of the intermediate winding and features an arc-shaped opening. Combined with the guide edge on the heat sink, this further concentrates and directs airflow towards the winding surface, forming a high-speed air curtain and significantly enhancing local convective heat transfer. Simultaneously, vents positioned between phases on the upper and lower pressure plates, along with obliquely mirrored baffles, guide the rising cooling air towards the middle second-phase winding. This increases airflow distribution to the intermediate phase and reduces the impact of heat radiation from adjacent windings, effectively solving the technical challenges of excessively high intermediate phase temperature and uneven three-phase temperature. Multiple heat dissipation pipes are evenly distributed circumferentially, ensuring uniform circumferential cooling of the winding.

[0032] In addition, the heat dissipation mechanism also includes a heat dissipation component 63, which is disposed at the bottom between the outer winding 43 and the intermediate winding 42 and is connected to the first heat dissipation pipe 61 to guide the air blown out by the fan to the surface of the intermediate winding 42.

[0033] Specifically, since the heat dissipation port 611 of the first heat dissipation pipe 61 is usually located on the side wall of the pipe, although the airflow ejected from the side wall can disturb the interlayer air, some airflow may escape along the pipe wall and fail to fully approach the outer surface of the intermediate winding 42. Therefore, a heat dissipation component 63 is added. The heat dissipation component 63 is located at the bottom between the outer winding 43 and the intermediate winding 42, that is, at the end near the lower pressure plate 2, and its inlet is connected to the bottom or side of the first heat dissipation pipe 61. When the fan starts, a portion of the cold air enters the heat dissipation component 63 from the bottom of the first heat dissipation pipe 61, and after being guided by the heat dissipation component 63, it is blown onto the surface of the intermediate winding 42 in a more concentrated manner, forming a cooling air film. It should be noted that the specific shape of the heat dissipation component 63 is not limited, as long as it can achieve the guiding function; for example, it can be a bent pipe, a guide plate, or a cavity with a specific outlet shape. This embodiment preferably adopts an arc-shaped heat dissipation block structure, which will be described below.

[0034] In addition, the heat sink 63 is an arc-shaped heat sink block. The arc-shaped surface of the arc-shaped heat sink block is adapted to the shape of the outer surface of the intermediate winding 42, and an arc-shaped opening is provided above the arc-shaped heat sink block to guide the airflow to flow close to the surface of the intermediate winding 42.

[0035] Specifically, the structure of the heat sink 63 has been optimized. The arc-shaped heat sink is integrally molded from an insulating material such as DMC molding compound, and its bottom is connected to the first heat dissipation pipe 61, with an internal cavity. The arc-shaped surface of the arc-shaped heat sink is in close contact with the outer arc surface of the intermediate winding 42, with the gap between them controlled at 1-3mm to ensure the accuracy of airflow guidance. The arc-shaped opening is located above the arc-shaped heat sink, i.e., on the side facing the surface of the intermediate winding 42. The length of the opening matches the axial height of the intermediate winding 42, and can extend from the bottom of the winding to the middle or even the top. When cold air enters the arc-shaped heat sink, it is constrained by the arc-shaped inner wall and ejected at high speed in a sheet-like form from the arc-shaped opening, forming an "air curtain" that is in close contact with the surface of the intermediate winding 42, greatly enhancing the convective heat transfer coefficient of the winding surface. It should be noted that one arc-shaped heat sink can be provided, or multiple arc-shaped heat sinks can be provided at intervals along the circumference, which can be selected by those skilled in the art according to the diameter of the winding and the heat generation. In addition, the arc-shaped heat sink can also be integrally molded with the first heat dissipation pipe 61 to simplify the assembly process.

[0036] In addition, the upper pressure plate 1 is provided with a first vent 11 and the lower pressure plate 2 is provided with a second vent. The first vent 11 and the second vent are used to form a convection heat dissipation channel.

[0037] Specifically, in addition to providing structural support, the upper pressure plate 1 and the lower pressure plate 2 also serve as components of the airflow channel. Both the first vent 11 and the second vent are through holes. The second vent on the lower pressure plate 2 serves as a cold air inlet, and the first vent 11 on the upper pressure plate 1 serves as a hot air outlet. Outside cold air enters the transformer through the second vent, flows upwards over the winding surface and heat dissipation pipes, and then its temperature rises before it is discharged from the first vent 11, forming a composite heat dissipation path of natural convection superimposed with forced convection from top to bottom. It is understood that the number and shape of the first vent 11 and the second vent are not limited to specific embodiments; for example, they can be circular holes, oblong holes, or grid-like openings, as long as sufficient ventilation area is ensured. In this embodiment, the vents are preferably located in the interphase area to facilitate uniform airflow distribution.

[0038] In addition, there are two of each of the first vent 11 and the second vent 11. The two first vent 11 are located between the first phase winding 4 and the second phase winding 8, and between the second phase winding 8 and the third phase winding 9, respectively. The positions of the two second vents correspond one-to-one with the positions of the two first vent 11.

[0039] Specifically, the positions and correspondences of the upper and lower vents are defined. Since the interphase gaps are the main channels for airflow after the three-phase windings are arranged, placing the vents directly above and below these gaps maximizes the utilization of this natural channel. Two second vents face the bottom of the two interphase gaps, and two first vents 11 face the top of the two interphase gaps, forming two independent vertical air ducts. This design allows cold air from below the lower pressure plate 2 to directly enter the interphase area, cooling the sides of adjacent windings respectively, avoiding flow dead zones caused by airflow obstruction by the winding structure. Furthermore, since there is an interphase air duct on each side of the second phase winding 8, both sides can be cooled, alleviating the heat dissipation problem of the middle phase to some extent. In practice, flanges or guide vanes can be installed at the edges of the vents to further optimize the airflow direction.

[0040] In addition, a partition 5 is provided between the first phase winding 4 and the second phase winding 8, and between the second phase winding 8 and the third phase winding 9.

[0041] Specifically, the partition 5 serves two purposes: first, it provides physical isolation, reducing heat radiation transfer between adjacent windings; second, it guides airflow, directing cool air along a pre-defined path. The partition 5 can be made of insulating material such as epoxy fiberglass board, with a thickness of 2-5mm. The vertical height of the partition 5 is approximately equal to or slightly lower than the height of the windings, to cover the main heat exchange area.

[0042] Furthermore, the two partitions 5 are arranged at an angle and are mirror images of each other, with the upper part of each partition 5 close to the second phase winding 8; the lower side of the partition between the first phase winding and the second phase winding is close to the first phase winding, and the lower side of the partition between the second phase winding and the third phase winding is close to the third phase winding.

[0043] Specifically, the left partition, located between the first phase winding 4 and the second phase winding 8, has its upper end inclined towards the second phase winding 8 and its lower end inclined towards the first phase winding 4. Similarly, the right partition, located between the second phase winding 8 and the third phase winding 9, has its upper end inclined towards the second phase winding 8 and its lower end inclined towards the third phase winding 9. The two partitions 5 form a figure-eight shape. This design allows for a wider channel at the bottom, facilitating the intake of more cool air from below. The upper and middle channels narrow, increasing airflow velocity and bringing the air closer to the surface of the second phase winding 8, thus enhancing cooling of the intermediate phase. Simultaneously, this inclination also allows the partitions to block some of the heat radiated from the first and third phase windings to the intermediate phase. This embodiment cleverly utilizes the inclined surfaces to both guide airflow preferentially to the intermediate phase and achieve heat insulation. In practice, the angle between the partition 5 and the vertical direction can be selected between 5° and 20°, depending on the winding spacing and airflow requirements.

[0044] Furthermore, there are multiple first heat dissipation pipes 61, which are distributed circumferentially between the outer winding 43 and the intermediate winding 42; there are also multiple second heat dissipation pipes 62, which are distributed circumferentially between the intermediate winding 42 and the inner winding 41.

[0045] Specifically, the number and distribution of heat dissipation pipes are limited. Since the windings are typically cylindrical, and the interlayer gap is a ring-shaped space, if only a single or few pipes are installed, cool air can only be blown in locally, failing to uniformly cool the windings along the entire circumference. Therefore, multiple pipes are evenly spaced along the circumferential direction, for example, 4, 6, or 8 pipes per layer, the specific number determined by the winding diameter and the fan's airflow and pressure. The multiple first heat dissipation pipes 61 are not connected end-to-end, each independently drawing air from the bottom fan, extending vertically, and having heat dissipation vents 611 on the side. This allows cool air to simultaneously blow into the winding layers from multiple directions, achieving uniform circumferential cooling and preventing localized overheating. Similarly, the second heat dissipation pipes 62 are also distributed circumferentially between the inner and middle windings. It is understandable that the first and second heat dissipation pipes 61 and 62 can be staggered circumferentially to reduce pressure on the winding insulation and create a more complex cross-flow heat exchange effect.

[0046] In addition, there are multiple heat dissipation vents 611, and the multiple heat dissipation vents 611 are arranged along the axial direction of the pipe.

[0047] Specifically, the form of the heat dissipation vent 611 is defined. Unlike the conventional single elongated opening, this design uses multiple independent through holes, arranged at equal or unequal intervals along the axial (vertical) direction on the sidewall of the pipe. The through holes can be round, elliptical, or square, with their diameter and spacing set according to cooling requirements. For example, where heat generation is more concentrated at the lower part of the winding, the diameter of the lower through holes can be designed to be larger or the spacing denser to distribute more airflow; the diameter of the upper through holes is smaller to maintain sufficient outlet air velocity. Compared to elongated openings, this multi-through-hole structure has higher structural strength and is less prone to deformation, and the distribution of heat dissipation airflow along the winding height can be finely controlled by adjusting the size and distribution of the holes. Experiments show that using a stepped hole diameter arrangement, with larger lower holes and smaller upper holes, results in a more uniform axial temperature rise distribution in the winding, preventing overheating at the top.

[0048] In addition, the heat dissipation port 611 is provided with a flow guiding edge.

[0049] Specifically, to further improve the directionality and efficiency of the cooling airflow, a guide edge is provided at the edge of the heat dissipation port 611. The guide edge refers to a flange or protrusion extending outward from the edge of the heat dissipation port 611 towards the winding surface; its cross-sectional shape can be straight, arc-shaped, or L-shaped. The function of the guide edge is to change the direction of the airflow, preventing the cool air from dissipating perpendicularly to the pipe wall, but instead directing it at a certain angle, such as tangentially or nearly parallel to the winding surface, thereby reducing airflow diffusion losses and allowing it to more concentratedly scour the winding surface. Specifically, the guide edge can be integrally injection molded with the heat dissipation pipes 61 and 62, or it can be fixed by bonding or thermal riveting. For circular through holes, the guide edge can be an annular flange surrounding the opening; for non-circular openings, it can be a strip guide plate along the long side of the opening. Although this feature is small, it has a significant effect on improving the local heat transfer coefficient, and is particularly suitable for the design of high power density dry-type transformers.

[0050] Example 2 The fan is arranged in two layers, upper and lower.

[0051] The lower fan is a curtain fan, which is fixedly installed on the upper surface of the lower pressure plate 2. Its air outlet is directly connected to the bottom of the first heat dissipation pipe 61 and the second heat dissipation pipe 62 or connected through the air collection box.

[0052] The curtain-type fan is characterized by moderate air pressure, large air volume, and airflow diffusion in a curtain shape, which can evenly deliver cold air into each heat dissipation pipe. After being guided by the heat dissipation port 611 and the arc-shaped heat dissipation block, it can force-cool the interlayer area between the inner winding 41, the middle winding 42 and the outer winding 43 of the coil winding, effectively removing the heat generated inside the winding.

[0053] The upper fan is a centrifugal fan, with its air inlet facing the inside of the transformer and its air outlet facing the phase-to-phase channel between the first phase winding 4 and the second phase winding 8, and between the second phase winding 8 and the third phase winding 9.

[0054] Centrifugal fans are characterized by high air pressure and strong airflow directionality. They can quickly draw in hot air from the top of the transformer and discharge it outwards. At the same time, they form a high-speed transverse airflow in the interphase area to assist in cooling the interphase area of ​​the transformer and promote overall air convection circulation.

[0055] By employing a two-tiered fan system, the lower curtain fan focuses on deep heat dissipation within the windings, while the upper centrifugal fan emphasizes interphase heat exchange and hot air exhaust. These complementary functions further enhance the overall heat dissipation efficiency and temperature uniformity of the transformer. It should be noted that the upper and lower fans can be controlled independently, with their speeds adjusted according to the load conditions to achieve energy savings and precise temperature control.

[0056] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A three-phase, three-winding dry-type transformer, characterized in that, include: Upper pressure plate (1) and lower pressure plate (2), with three iron cores (7) provided between the upper pressure plate (1) and the lower pressure plate (2). The first phase winding (4), the second phase winding (8), and the third phase winding (9) are arranged sequentially on the three iron cores (7). The first phase winding (4), the second phase winding (8), and the third phase winding (9) have the same structure. A fan (3) is disposed on the upper surface of the lower pressure plate (2); The heat dissipation mechanism is respectively installed inside the first phase winding (4), the second phase winding (8) and the third phase winding (9), and is connected to the fan (3) to introduce outside cold air into the winding for heat dissipation; Each phase winding includes an inner winding (41), an intermediate winding (42), and an outer winding (43) wound sequentially from the inside to the outside. The heat dissipation mechanism includes a first heat dissipation pipe (61) and a second heat dissipation pipe (62). The first heat dissipation pipe (61) passes between the outer winding (43) and the intermediate winding (42), and the second heat dissipation pipe (62) passes between the intermediate winding (42) and the inner winding (41). The bottoms of the first heat dissipation pipe (61) and the second heat dissipation pipe (62) are connected to the fan (3), the tops are sealed, and the sides are provided with heat dissipation vents (611).

2. A three-phase, three-winding dry-type transformer according to claim 1, characterized in that, The heat dissipation mechanism further includes a heat dissipation component (63), which is disposed at the bottom between the outer winding (43) and the intermediate winding (42) and is connected to the first heat dissipation pipe (61) to guide the air blown out by the fan to the surface of the intermediate winding (42).

3. A three-phase, three-winding dry-type transformer according to claim 2, characterized in that, The heat sink (63) is an arc-shaped heat sink block. The arc-shaped surface of the arc-shaped heat sink block is adapted to the shape of the outer surface of the intermediate winding (42). An arc-shaped opening is provided above the arc-shaped heat sink block to guide the airflow to flow close to the surface of the intermediate winding (42).

4. A three-phase, three-winding dry-type transformer according to claim 1, characterized in that, The upper pressure plate (1) has a first vent (11) and the lower pressure plate (2) has a second vent. The first vent (11) and the second vent are used to form a convection heat dissipation channel.

5. A three-phase, three-winding dry-type transformer according to claim 4, characterized in that, There are two first vents (11) and two second vents. The two first vents (11) are located between the first phase winding (4) and the second phase winding (8), and between the second phase winding (8) and the third phase winding (9), respectively. The positions of the two second vents correspond one-to-one with the positions of the two first vents (11).

6. A three-phase, three-winding dry-type transformer according to claim 1, characterized in that, A partition (5) is provided between the first phase winding (4) and the second phase winding (8), and between the second phase winding (8) and the third phase winding (9).

7. A three-phase, three-winding dry-type transformer according to claim 6, characterized in that, The two partitions (5) are arranged at an angle and are mirror images of each other. The upper part of each partition (5) is close to the second phase winding (8); the lower side of the partition between the first phase winding and the second phase winding is close to the first phase winding, and the lower side of the partition between the second phase winding and the third phase winding is close to the third phase winding.

8. A three-phase, three-winding dry-type transformer according to claim 1, characterized in that, There are multiple first heat dissipation pipes (61), and the multiple first heat dissipation pipes (61) are distributed circumferentially between the outer winding (43) and the intermediate winding (42); there are multiple second heat dissipation pipes (62), and the multiple second heat dissipation pipes (62) are distributed circumferentially between the intermediate winding (42) and the inner winding (41).

9. A three-phase, three-winding dry-type transformer according to claim 1, characterized in that, The number of heat dissipation ports (611) is multiple, and the multiple heat dissipation ports (611) are arranged along the axial direction of the pipe.

10. A three-phase, three-winding dry-type transformer according to claim 1, characterized in that, The heat dissipation port (611) is provided with a flow guiding edge.

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