Natural ester transformer winding structure

Abstract

The application relates to a natural ester transformer winding structure, comprising a winding wire cake, further comprising: a shielding section arranged at the head end of the winding wire cake; and a large oil channel arranged at the head end and the tail end of the winding, the thickness of the large oil channel being larger than that of a basic oil channel in the winding. The above scheme provided by the application increases the longitudinal capacitance of the winding, the longitudinal capacitance can compensate the ground capacitance current of the winding, the impulse voltage distribution of the winding is more uniform, the impulse overvoltage capacity of the transformer is higher, if the shielding section is not used, the impulse voltage mostly falls on the head end of the winding, which is very harmful to the insulation of the head end of the winding, meanwhile, the arrangement of the large oil channel reduces the hot spot temperature rise of the winding end, improves the average temperature rise of the whole winding, ensures that the temperature rise of the transformer winding is more uniform, and further improves the reliability of the transformer during operation.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and in particular to a natural ester transformer winding structure. Background Technology

[0002] Natural ester insulating oil, as a green and environmentally friendly liquid insulating medium, possesses excellent flame retardancy, heat resistance, and electrical properties. It can significantly reduce transformer fires and explosions caused by transformer oil ignition, and effectively delay the aging of insulation materials and the decline in insulation strength due to overload operation, thus greatly improving power supply reliability. Therefore, the application of natural ester insulating oil in transformers is becoming increasingly widespread. However, natural ester insulating oil has a higher dielectric constant and viscosity than mineral oil, resulting in extremely uneven distribution of winding impulse voltage. If the same winding structure is used as that of a mineral oil transformer, its insulation reliability under impulse overvoltage will be lower than that of a mineral oil transformer, significantly reducing operational reliability. Summary of the Invention

[0003] Therefore, it is necessary to provide a winding structure for a natural ester transformer to address the problem of low operational reliability of existing natural ester transformers in application.

[0004] The present invention provides a natural ester transformer winding structure, including a winding coil and a shielding section disposed at the beginning of the winding coil;

[0005] Large oil channels are provided at both ends of the winding, and the thickness of the large oil channels is greater than the thickness of the basic oil channels in the winding.

[0006] The aforementioned natural ester transformer winding structure incorporates a longitudinal capacitance in the shielding section. This longitudinal capacitance compensates for the winding-to-ground capacitance current, resulting in a more uniform distribution of the winding impulse voltage and a higher transformer withstand capability against impulse overvoltages. Without shielding, the impulse voltage would mostly drop at the winding start-up point, which is highly detrimental to the insulation of the winding start-up point. Simultaneously, the large oil channel reduces the temperature rise of hot spots at the winding ends, improves the average temperature rise of the entire winding, ensures a more uniform temperature rise in the transformer winding, and thus enhances the reliability of the transformer during operation.

[0007] In one embodiment, the shielding section is provided at the beginning of each winding coil.

[0008] In one embodiment, the shielding section includes a first shielding line and a second shielding line. The first shielding line is disposed between the first turn and the second turn on the outer diameter side of the beginning of the winding coil, and the second shielding line is disposed between the second turn and the third turn in the beginning of the winding coil.

[0009] In one embodiment, the insulation thickness of both the first screen wire and the second screen wire is greater than the thickness of the working turns in the winding coil.

[0010] In one embodiment, the end electrodes of both the first screen line and the second screen line are provided with insulating sleeves.

[0011] In one embodiment, the first six sections of the winding coil at the upper end of the transformer winding have the same structure.

[0012] In one embodiment, the shielding section further includes a third shielding line disposed between the first and second turns on the outer diameter side of the seventh winding coil.

[0013] In one embodiment, the insulation thickness of the third screen wire is greater than the thickness of the working turns in the winding coil.

[0014] In one embodiment, the shielding section at the beginning of the winding coil is provided with the large oil channel, and at least two of the large oil channels are provided at the end of the winding coil.

[0015] In one embodiment, an oil baffle is provided in the basic oil passage of the winding coil. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the winding structure of a natural ester transformer provided in an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of another natural ester transformer winding structure provided in an embodiment of the present invention.

[0018] The markings in the image are as follows:

[0019] 1. First turn; 2. Second turn; 3. Third turn; 4. First screen line; 5. Second screen line; 6. Third screen line; 7. Working connection line; 8. Screen line connection line; 9. Main oil passage; 10. Basic oil passage; 11. Oil baffle; 100. Shielding section. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying 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.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to 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.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0026] Natural ester insulating oil, as a green and environmentally friendly liquid insulating medium, possesses excellent flame retardancy, heat resistance, and electrical properties. It can significantly reduce transformer fires and explosions caused by transformer oil ignition, and effectively delay the aging of insulation materials and the decline in insulation strength due to overload operation, thus greatly improving power supply reliability. Therefore, the application of natural ester insulating oil in transformers is becoming increasingly widespread. However, natural ester insulating oil has a higher dielectric constant and viscosity than mineral oil, resulting in extremely uneven distribution of winding impulse voltage. If the same winding structure is used as that of a mineral oil transformer, its insulation reliability under impulse overvoltage will be lower than that of a mineral oil transformer, significantly reducing operational reliability.

[0027] To solve the above problems, such as Figure 1 As shown, in one embodiment of the present invention, a natural ester transformer winding structure is provided, including a winding coil, and further including: a shielding section 100 and a large oil channel 9, wherein the shielding section is disposed at the beginning of the winding, the large oil channel 9 is disposed at both the beginning and end of the winding, and the thickness of the large oil channel 9 is greater than the thickness of the basic oil channel 10 in the winding.

[0028] By adopting the above technical solution, the shielding section adds the longitudinal capacitance of the winding. This longitudinal capacitance can compensate for the winding-to-ground capacitance current, making the winding impulse voltage distribution more uniform and the transformer's ability to withstand impulse overvoltage higher. Without shielding, most of the impulse voltage drops at the winding start end, which is very detrimental to the insulation of the winding start end. At the same time, the setting of large oil channels reduces the temperature rise of hot spots at the winding end, improves the average temperature rise of the entire winding, ensures a more uniform temperature rise of the transformer winding, and thus improves the reliability of the transformer during operation.

[0029] In some embodiments, the starting end of each winding in this application is provided with a shielding section 100. Specifically, as shown in the figure... Figure 1 and combined Figure 2 As shown, the shielding section 100 includes a first shield line 4 and a second shield line 5. The first shield line 4 is provided between the first turn 1 and the second turn 2 on the outer diameter side of the winding coil end, and the second shield line 5 is provided between the second turn 2 and the third turn 3 in the winding coil end.

[0030] The first six windings at the upper end of the transformer have the same structure. Each segment of the winding is connected by a working connecting line 7. Also, starting from the beginning of the winding, every two shielding segments 100 are connected by a shielding line connecting line 8. A third shielding line 6 is provided in each of the seventh to tenth winding segments. This third shielding line 6 is located between the first and second turns on the outer diameter side of the seventh winding segment. The positions of the third shielding lines 6 in the eighth to tenth winding segments are the same as those in the seventh winding segment.

[0031] In some embodiments, the insulation thickness of the first screen line 4, the second screen line 5, and the third screen line 6 in this application is greater than the thickness of the working turns in the winding coil. Since the voltage between the working line and the screen line is greater than the voltage between the working lines, the insulation thickness of the turns between the working line and the screen line must also be greater than the insulation thickness between the working lines. The insulation thickness between the working line and the screen line is determined by both the working line insulation and the screen line insulation. The working line insulation cannot be increased, so only the screen line insulation thickness can be increased; that is, the insulation thickness of the first screen line 4, the second screen line 5, and the third screen line 6 is set to be greater than the thickness of the working turns in the winding.

[0032] In some embodiments, the end electrodes of the first screen line 4, the second screen line 5, and the third screen line 6 in this application are all provided with insulating sleeves, thereby preventing partial discharge from occurring.

[0033] In some embodiments, the shielding section 100 at the beginning of the winding in this application is provided with a large oil channel 9, and at least two large oil channels 9 are provided at the end of the winding. The oil channel arrangement in the winding design reduces the temperature rise of hot spots at the winding ends, improves the average temperature rise of the entire winding, and ensures a more uniform temperature rise of the transformer winding.

[0034] In some embodiments, such as Figure 2 As shown, an oil baffle 11 is provided in the basic oil passage 10 of the winding in this application. The oil baffle 11 is provided to facilitate the flow of oil in a specified direction.

[0035] In summary, the first six windings at the upper end of the transformer winding provided in this application have the same structure, with the winding coils connected by working connecting lines 7. Furthermore, starting from the beginning of the winding, every two shielding sections 100 are connected by shielding line connecting lines 8. A third shielding line 6 is provided in each of the seventh to tenth winding coils. This third shielding line 6 is located between the first and second turns on the outer diameter side of the seventh winding coil. The positions of the third shielding lines 6 in the eighth to tenth winding coils are the same as those in the seventh winding coil. Each shielding section 100 at the beginning of the winding is provided with a large oil passage 9, and at least two large oil passages 9 are provided at the end of the winding. The shielding section increases the longitudinal capacitance of the winding, which can compensate for the winding-to-ground capacitance current, making the winding impulse voltage distribution more uniform and the transformer's ability to withstand impulse overvoltage higher. Without shielding, the impulse voltage would mostly drop at the winding start end, which is very detrimental to the insulation of the winding start end. At the same time, the setting of large oil channels reduces the temperature rise of hot spots at the winding end, improves the average temperature rise of the entire winding, ensures a more uniform temperature rise of the transformer winding, and thus improves the reliability of the transformer during operation.

[0036] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0037] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A natural ester transformer winding structure, comprising winding coils, characterized in that, Also includes: A shielding section (100) is disposed at the beginning of the winding coil; Large oil passage (9) is provided at both ends of the winding coil, and the thickness of the large oil passage (9) is greater than the thickness of the basic oil passage (10) in the winding coil. The shielding section (100) includes a first shield line (4) and a second shield line (5). The first shield line (4) is provided between the first turn (1) and the second turn (2) on the outer diameter side of the first end of the winding coil. The second shield line (5) is provided between the second turn (2) and the third turn (3) in the first end of the winding coil. The shielding section (100) at the beginning of the winding coil is provided with the large oil passage (9), and at least two large oil passages (9) are provided at the end of the winding coil. An oil baffle (11) is provided in the basic oil passage (10) of the winding coil.

2. The natural ester transformer winding structure according to claim 1, characterized in that, The first end of each winding coil is provided with the shielding section (100).

3. The natural ester transformer winding structure according to claim 1, characterized in that, The insulation thickness of the first screen wire (4) and the second screen wire (5) is greater than the thickness of the working wire turns in the winding coil.

4. The natural ester transformer winding structure according to claim 1, characterized in that, The end electrodes of the first screen line (4) and the second screen line (5) are both provided with insulating sleeves.

5. The natural ester transformer winding structure according to claim 1, characterized in that, The first six discs at the upper end of the transformer winding have the same structure.

6. The natural ester transformer winding structure according to claim 5, characterized in that, The shielding section (100) also includes a third shield line (6), which is disposed between the first and second turns on the outer diameter side of the seventh winding coil.

7. The natural ester transformer winding structure according to claim 6, characterized in that, The insulation thickness of the third screen wire (6) is greater than the thickness of the working wire turns in the winding coil.

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