High voltage coil of a dry-type transformer and method of winding thereof

Abstract

A high-voltage coil of a dry-type transformer includes n conductors, characterized in that the n conductors are formed by sequentially connecting corresponding sub-coils from the following sub-coil array: the sub-coil array includes n columns of sub-coils arranged radially, each column of sub-coils being formed by m sub-coils arranged axially, each sub-coil being wound with a single conductor in a continuous structure, and the conductor specifications of each sub-coil being the same; the upper leads of the uppermost sub-coils in the n columns of sub-coils are connected in parallel to form the beginning of the high-voltage coil, and the lower leads of the lowermost sub-coils are connected in parallel to form the end of the high-voltage coil; the upper lead of any lowermost sub-coil is connected axially to one of the sub-coils in the same radial direction via connecting wires, and then connected to the lower lead of one of the uppermost sub-coils. A winding method is also disclosed. Using the above structure, the n conductors can be completely transposed, resulting in high production efficiency.

Description

Technical Field

[0001] This invention relates to a transformer coil and its winding method, specifically to a high-voltage coil of a dry-type transformer and its winding method. Background Technology

[0002] A dry-type transformer is a device that uses the principle of electromagnetic induction to change AC voltage. It mainly consists of an iron core made of silicon steel sheets and high- and low-voltage coils cast with epoxy resin. Coils are generally divided into two types: layered and continuous. A layered coil is formed by continuously winding the coil turns in layers along the axial direction. A continuous coil is formed by continuously winding the coil turns radially into coil discs and then arranging many coil discs along the axial direction.

[0003] Continuous coils are multiple coils formed by continuously winding one or more flat wires on a winding die support. The multi-wire parallel winding technique involves winding multiple wires together and manually transposing them between each coil. For example, the structure disclosed in Chinese patent application CN201320158022.1, "Dry-type Transformer," involves a circulating current generated due to induced potential differences arising from two or more wires being in different leakage magnetic fields. This increases the additional losses of the coil. Therefore, the transformer in this document reduces the circulating current between the parallel wires to near zero through coil winding transposition, thereby reducing the additional losses caused by the circulating current and ensuring similar temperature rises for each parallel wire. However, the manual transposition operation results in low production efficiency.

[0004] The continuous high-voltage coil structure described above offers advantages such as balanced voltage gradient, low partial discharge during transformer operation, and high impact resistance. However, this structure is primarily used in small-to-medium-sized 10kV high-voltage coils that do not require axial air ducts. For high-voltage coils in large-capacity transformers, additional air ducts are needed for heat dissipation. Such a multi-wire parallel winding structure with axial air ducts suffers from drawbacks such as time-consuming operation, multiple contact points, and low production efficiency. Therefore, continuous high-voltage coil structures are generally not used in large-capacity transformers. In other words, current technology limits the application of continuous high-voltage coil structures in large-capacity transformers.

[0005] Therefore, further improvements are needed for the existing technology. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to propose a high-voltage coil for a dry-type transformer with high production efficiency, in light of the above-mentioned current state of the technology.

[0007] The second technical problem to be solved by the present invention is to propose a high-efficiency winding method for the high-voltage coil of the aforementioned dry-type transformer, in view of the above-mentioned technical status quo.

[0008] The technical solution adopted by the present invention to solve the first technical problem mentioned above is as follows: a high-voltage coil of a dry-type transformer, comprising n conductors, characterized in that the n conductors are respectively formed by sequentially connecting corresponding sub-coils in the following sub-coil array: the sub-coil array includes n sub-coil columns arranged radially, each sub-coil column being composed of m sub-coils arranged axially, where n and m are positive integers not less than 2, each sub-coil being wound with only a single insulated conductor in a continuous structure, and the conductor specifications of each sub-coil being the same, the uppermost sub-coil in the n sub-coil columns having its uppermost lead-out end becoming one end of each conductor, and the ends of each conductor being connected in parallel as... At the beginning of the high-voltage coil, the lower output of each of the n lowest sub-coils in the row of sub-coils becomes the other end of each conductor. The other ends of each conductor are connected in parallel to form the end of the high-voltage coil. At the same time, the upper output of any of the lowest sub-coils is connected in series along the axial direction to one of the sub-coils in the same radial direction, and then connected to the lower output of one of the uppermost sub-coils. This makes the high-voltage coil a structure in which the n conductors of the same length and cross-section are continuously wound and then connected in parallel. At the same time, tap terminals are led out from each sub-coil in the same radial direction at the corresponding position. The tap terminals are connected in parallel to form the tap output of the high-voltage coil.

[0009] Preferably, a first insulating layer is provided between adjacent sub-coil columns in the n sub-coil columns to ensure insulation between the coils in each column. Alternatively, an axial air passage and a first insulating layer placed outside the axial air passage are provided between adjacent sub-coil columns in the n sub-coil columns. This ensures insulation while facilitating heat dissipation between adjacent sub-coil columns.

[0010] Preferably, the n sub-coil columns are further divided axially into a lower coil group and an upper coil group, with a second insulating layer between the lower and upper coil groups. The upper sub-coil in the lower coil group becomes the lower tap section with three upper tap leads, and the remaining sub-coil in the lower coil group becomes the lower basic section. Similarly, the lower sub-coil in the upper coil group becomes the upper tap section with three lower tap leads, and the remaining sub-coil in the upper coil group becomes the upper basic section. These lower and upper tap leads are the tap leads of the high-voltage coil. This structure enables the transformer equipped with the high-voltage coil of this invention to have voltage regulation capabilities, while also being simple to manufacture and having high production efficiency.

[0011] Preferably, the number of turns of each sub-coil in the lower and upper basic sections is substantially equal, i.e., the number of turns is the same, or the allowable deviation is no greater than 1%. In the lower and upper basic sections, each sub-coil column has n sub-coils in the axial direction. In the lower and upper tap sections, the lead-out terminals for connecting the corresponding sub-coils are drawn from the midpoint between adjacent tap terminals. Since the number of turns of all 2n² sub-coils in the lower and upper basic sections is equal, and the number of turns of the two sub-coils between adjacent tap terminals is also equal, this simplifies the planning process for the series connection method and makes it easier to obtain a structure composed of n conductors of the same length and cross-section, continuously wound and then connected in parallel.

[0012] Preferably, in the lower and upper basic segments, there are n connecting lines between adjacent sub-coils, and the insulation distance between the connecting lines is not less than 10mm. Since the basic segment coil has a large number of turns and a large voltage, it is necessary to ensure that there is a sufficient insulation distance between the connecting lines.

[0013] Preferably, the upper and lower coil groups constitute a coil group, and the coil group has two subgroups, which are distributed axially to form a first coil group and a second coil group. The coils of the first and second coil groups are wound in opposite directions, so that the beginnings of the first and second coil groups are adjacent and connected in parallel to form the beginning of the high-voltage coil in the middle. The end of the first coil group becomes the first end of the high-voltage coil, and the end of the second coil group becomes the second end of the high-voltage coil. This structure minimizes the voltage difference between adjacent positions of the inner and outer sub-coils at the same height of the transformer, and the voltage gradient of the high-voltage coil of the entire transformer is evenly distributed from top to bottom, resulting in a lower partial discharge level. Furthermore, this method of individually winding and then connecting multiple conductors in parallel allows for the production of transformers with larger capacity.

[0014] Preferably, an inner insulating layer is provided on the inner side of the n sub-coil columns, and an outer insulating layer is provided on the outer side of the n sub-coil columns.

[0015] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a method for winding the high-voltage coil of the above-mentioned dry-type transformer, characterized by comprising the following steps:

[0016] Step 1: The inner insulation layer is tightly wrapped around the coil mold;

[0017] Step 2: On the outer surface of the inner insulation layer, the first sub-coil at the bottom of the first sub-coil column is wound in a continuous winding manner, and the upper and lower ends of the first sub-coil are reserved as the upper and lower lead wires for connection.

[0018] Step 3: Repeat step 2 on the first sub-coil, winding the second sub-coil in the first sub-coil column from bottom to top until the m-th sub-coil in the first sub-coil column is completed. Reserve the upper and lower ends of each sub-coil as the upper and lower lead wires for connection. At the same time, lead wires out from the sub-coil at the corresponding positions as the taps of the high-voltage coil.

[0019] Step 4: Wrap the outer surface of the first winding sub-coil column tightly with the first insulating layer, or first place an axial air channel on the outer surface of the first winding sub-coil column, and then wrap the first insulating layer around the axial air channel; if n=2, proceed to step 6; if n≧3, proceed to step 5.

[0020] Step 5: Repeat steps 2 to 4 on the outside of the first insulation layer to continue winding until the winding of the (n-1)th sub-coil column is completed, and wrap the first insulation layer on the outer surface of the (n-1)th sub-coil column, or first place an axial air channel on the outer surface of the (n-1)th sub-coil column, and then wrap the first insulation layer around the axial air channel.

[0021] Step 6: Repeat steps 2 to 3 on the outer surface of the first insulating layer of the (n-1)th sub-coil column until the winding of the nth sub-coil column is completed;

[0022] Step 7: Connect the upper leads of the m-th sub-coil in each sub-coil column in parallel to form the beginning of the high-voltage coil; connect the lower leads of the first sub-coil in each sub-coil column in parallel to form the end of the high-voltage coil; connect the lower lead of the m-th sub-coil in each sub-coil column axially downwards through connecting wires to one of the sub-coils in the same radial direction, and then connect it to the upper lead of the first sub-coil in one of the n sub-coil columns to ensure that the n conductors formed after series connection have the same length and the same cross-section; at the same time, connect the tap ends of the sub-coils in the same radial direction in the n sub-coil columns in parallel to form the corresponding tap ends of the high-voltage coil.

[0023] Step 8: Wrap the outer insulation layer around the nth sub-coil column, leaving out and fixing the beginning, end and tap ends of the high-voltage coil.

[0024] The high-voltage coil of this invention differs from the existing technology where n conductors are initially connected in parallel and wound as a whole. Instead, it employs a structure where n conductors are individually wound into coils and then connected in parallel. Therefore, compared to the prior art, this invention offers greater freedom in transposition. Complete conductor transposition can be achieved by connecting the upper lead of any of the lowermost sub-coils axially to one of the sub-coils on the same radial direction via connecting wires, and then connecting this connection to the lower lead of the uppermost sub-coil. Furthermore, in this invention, n can be any positive integer not less than 2, ensuring that the n conductors have equal lengths, equal induced potentials, and no circulating current in the parallel conductors. In addition, since this invention only requires normal continuous winding with lead ends left out during the winding process, and no transposition is needed, the high-voltage coil of this invention can be directly wound using existing automatic winding machines, resulting in high production efficiency and low labor costs. This solves the problem of manual coil turning required in the continuous winding process of existing technologies, and also allows the continuous high-voltage coil structure to be successfully applied to large-capacity transformers. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the coil structure in Embodiment 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the coil in Embodiment 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the coil structure in Embodiment 2 of the present invention;

[0028] Figure 4 This is a schematic diagram of the coil in Embodiment 2 of the present invention;

[0029] Figure 5 This is a schematic diagram of the coil in Embodiment 3 of the present invention;

[0030] Figure 6 This is a schematic diagram of the coil in Embodiment 4 of the present invention;

[0031] Figure 7 This is a schematic diagram of the coil in Embodiment 5 of the present invention;

[0032] Figure 8 This is a schematic diagram of the coil in Embodiment 6 of the present invention. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] The high-voltage coil of the dry-type transformer described below comprises n conductors, each of which is formed by sequentially connecting corresponding sub-coils in the following sub-coil array: The sub-coil array consists of n radially distributed sub-coil columns, each sub-coil column composed of m axially arranged sub-coils, where n and m are positive integers not less than 2. n can be a positive integer such as 2, 3, or 4, selected according to the voltage level of the high-voltage coil. m is chosen with relatively larger values, such as 10, 12, or 14, also selected according to the voltage level of the high-voltage coil. To fully understand the structure of the high-voltage coil of this dry-type transformer, different positive integer values ​​for n and m will be used in the following description.

[0035] Example 1

[0036] like Figures 1-2 The high-voltage coil of a dry-type transformer shown is wound with two conductors, which are respectively formed by sequentially connecting corresponding sub-coils in the following sub-coil array: The sub-coil array includes two sub-coil columns distributed radially (i.e., n=2, forming inner and outer sub-coil columns), and each sub-coil column is composed of 12 sub-coils (i.e., m=12) arranged axially. For ease of description and understanding, each sub-coil is numbered according to its position. The number is composed of two numbers, the first number representing the column number of the sub-coil from the inside out, and the second number representing the number of the sub-coil from the bottom up. For example, the sub-coil at the bottom of the innermost column is numbered 1-1, the sub-coil at the second lowest position of the innermost column is numbered 1-2, the sub-coil at the top of the innermost column is numbered 1-12, and the sub-coil at the top of the outermost column is numbered 2-12. The high-voltage coil in this embodiment includes a total of 24 sub-coils. Each sub-coil is made of a single conductor with external insulation wound in a continuous structure, and the conductor specifications of each sub-coil are the same.

[0037] In this embodiment, the uppermost sub-coils have their upper leads becoming one end of each conductor. The ends of these conductors are connected in parallel to form the head 1 of the high-voltage coil, i.e., the leads of the two sub-coils numbered 1-12 and 2-12 are connected in parallel to form the head 1 of the high-voltage coil. The lowermost sub-coils have their lower leads becoming the other end of each conductor. The other ends of these conductors are connected in parallel to form the tail 2 of the high-voltage coil, i.e., the leads of the two sub-coils numbered 1-1 and 2-1 are connected in parallel to form the tail 2 of the high-voltage coil.

[0038] In order to meet the voltage regulation requirements of dry-type transformers, tap terminals need to be led out from each sub-coil on the same radial direction at the corresponding position. The tap terminals are connected in parallel and used as tap terminals 3 of the high-voltage coil. In this embodiment, the two sub-coil columns can be divided into a lower coil group 6 and an upper coil group 7 along the axial direction. The lower coil group 6 consists of sub-coils numbered 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 2-1, 2-2, 2-3, 2-4, 2-5, and 2-6. The upper coil group 7 consists of sub-coils numbered 1-7, 1-8, 1-9, 1-10, 1-11, 1-12, 2-7, 2-8, 2-9, 2-10, 2-11, and 2-12. The lower coil group 6 can be further divided into a lower basic section 6a and a lower tap section 6b according to its function. Similarly, the upper coil group 7 is also divided into an upper basic section 7a and an upper tap section 7b according to its function. In the axial direction, each column of the lower basic section 6a and the upper basic section 7a has two sub-coils.

[0039] The specific division of the sub-coils and the setting of the tap-out wires 3 are as follows: the upper sub-coils in the lower coil group 6 (sub-coils numbered 1-3, 1-4, 1-5, 1-6, 2-3, 2-4, 2-5, 2-6) become the lower tap-out segment 6b from which three lower tap-out wires 3a are drawn. The remaining sub-coils in the lower coil group 6 (sub-coils numbered 1-1, 1-2, 2-1, 2-2) become the lower basic segment 6a. The three lower tap-out wires 3a are respectively drawn from the upper ends of sub-coils numbered 1-2 and 2-2 and the lower ends of sub-coils numbered 1-3 and 2-3 and connected in parallel; the upper ends of sub-coils numbered 1-4 and 2-4 and the lower ends of sub-coils numbered 1-5 and 2-5 and connected in parallel; and the upper ends of sub-coils numbered 1-6 and 2-6 are drawn from the upper ends and connected in parallel. The upper coil group 7... The lower sub-coils (numbered 1-7, 1-8, 1-9, 1-10, 2-7, 2-8, 2-9, and 2-10) become the upper tap section 7b from which three upper tap leads 3b are drawn. The remaining sub-coils in this upper coil group 7 (numbered 1-11, 1-12, 2-11, and 2-12) become the upper basic section 7a. The three upper tap leads 3b are respectively drawn from the lower ends of sub-coils numbered 1-7 and 2-7 and connected in parallel, drawn from the upper ends of sub-coils numbered 1-8 and 2-8 and the lower ends of sub-coils numbered 1-9 and 2-9 and connected in parallel, and drawn from the upper ends of sub-coils numbered 1-10 and 2-10 and the lower ends of sub-coils numbered 1-11 and 2-11 and connected in parallel. These lower and upper tap leads 3a and 3b are the tap leads 3 of the high-voltage coil.

[0040] To simplify the series connection structure, the number of turns of each sub-coil in the lower basic section 6a and the upper basic section 7a is basically equal. If necessary, a deviation of no more than 1% is allowed. The corresponding sub-coil series connection leads out from the middle number of turns between adjacent taps in the lower tap section 6b and the upper tap section 7b.

[0041] In this embodiment, the number of turns of the sub-coils is distributed as follows: during winding, the number of turns of the sub-coils in the lower basic section 6a and the upper basic section 7a is kept to be approximately equal, that is, the number of turns of the sub-coils numbered 1-1, 2-1, 1-2, 2-2, 1-11, 2-11, 1-12, and 2-12 are approximately equal. In other words, when half of the number of tap turns is removed from the number of turns in the lower and upper coil groups 6 and 7 respectively, the lead wire is drawn out. At the same time, in the lower and upper tap sections 6b and 7b... The corresponding sub-coils are connected in series at the middle number of turns between adjacent taps. That is, the sub-coils numbered 1-3, 2-3, 1-4, and 2-4 have approximately the same number of turns; the sub-coils numbered 1-5, 2-5, 1-6, and 2-6 have approximately the same number of turns; the sub-coils numbered 1-7, 2-7, 1-8, and 2-8 have approximately the same number of turns; and the sub-coils numbered 1-9, 2-9, 1-10, and 2-10 have approximately the same number of turns.

[0042] Next, except for the first end 1, the last end 2, and the branch line 3, the remaining branches are connected in series according to the following pattern: the upper branch of any of the lowermost sub-coils is connected in series along the axial direction through the connecting line 8 to one of the sub-coils in the same radial direction, and then connected to the lower branch of one of the uppermost sub-coils, so that the high-voltage coil forms a structure in which two conductors of the same length and the same cross-section are continuously wound and then connected in parallel.

[0043] In this embodiment, the specific series connection method of the sub-coils is as follows: the sub-coil numbered 1-1 is the lowest sub-coil, and its upper lead is connected axially to the lower lead of the sub-coil numbered 2-2 via connecting wire 8. Then, the upper lead of the sub-coil numbered 2-2 continues to be connected in series with the lower lead of the sub-coil numbered 2-3 according to the above pattern, and so on, until the sub-coils numbered 2-3, 1-4, 1-5, 2-6, 2-7, 1-8, 1-9, and 2-10 are connected in series in sequence. Finally, the upper lead of the sub-coil numbered 2-11 is connected to the lower lead of the sub-coil numbered 1- The lower leads of coil 12 are connected together; the sub-coils numbered 2-1, 1-2, 1-3, 2-4, 2-5, 1-6, 1-7, 2-8, 2-9, 1-10, 1-11, and 2-12 are connected in series from bottom to top in the same pattern. It should be noted that the leads between the lower coil group 6 and the upper coil group 7 (between numbered 2-6 and 2-7, and between numbered 1-6 and 1-7) are disconnected after winding and are reconnected as needed during use. This forms a structure in which two wires of the same length are wound continuously and then connected in parallel.

[0044] The insulation configuration in this embodiment is as follows: a first insulating layer 4 is provided between adjacent sub-coil columns in the inner and outer sub-coil columns, or a combination of an axial air passage and a first insulating layer 4 is provided, that is, a first insulating layer 4 is provided between the inner sub-coil column and the outer sub-coil column, or an axial air passage and a first insulating layer 4 located outside the axial air passage are provided between the inner sub-coil column and the outer sub-coil column; a second insulating layer 5 is provided between the lower and upper coil groups 6 and 7, that is, a second insulating layer 5 is provided between sub-coil numbers 1-6 and 2-6 and sub-coil numbers 1-7 and 2-7; in the lower basic segment 6a and the upper basic segment 7a, the upper and lower adjacent sub-coil groups are respectively It has two connecting wires 8, and the mutual insulation distance between the connecting wires 8 is not less than 10mm. That is, the mutual insulation distance between the connecting wire 8 between the sub-coils numbered 1-1 and 2-2 and the connecting wire 8 between the sub-coils numbered 2-1 and 1-2 is not less than 10mm, and the mutual insulation distance between the connecting wire 8 between the sub-coils numbered 2-11 and 1-12 and the connecting wire 8 between the sub-coils numbered 1-11 and 2-12 is not less than 10mm. The inner side of the two sub-coil rows is provided with an inner insulation layer (not shown in the figure), and the outer side of the two sub-coil rows is provided with an outer insulation layer (not shown in the figure).

[0045] The winding method in this embodiment includes the following steps:

[0046] Step 1: Tightly wrap the inner insulation layer on the coil mold. Specifically, first tightly wrap the required quantity and specifications of insulating mesh cloth on the coil mold, and then wrap the outer surface of the insulating mesh cloth with glass cloth tape to ensure that the insulating mesh cloth is tight and the surface is smooth.

[0047] Step 2: On the outer surface of the inner insulation layer, the first sub-coil at the bottom of the first sub-coil column, i.e., the sub-coil numbered 1-1, is wound in a continuous winding manner, and the upper and lower ends of the sub-coil are reserved as the upper and lower lead wires for connection.

[0048] Step 3: Repeat Step 2 on the sub-coil numbered 1-1, winding the second sub-coil in the first sub-coil column from bottom to top, i.e., the sub-coil numbered 1-2, until the 12th sub-coil in the first sub-coil column is completed, i.e., the sub-coil numbered 1-12. When half of the sub-coil is wound, place the second insulation layer 5 on the current sub-coil. The number of turns of the 1st, 2nd, 11th, and 12th sub-coils in the first sub-coil column is basically the same. The number of turns of the 3rd and 4th sub-coils is basically the same. The number of turns of the 5th and 6th sub-coils is basically the same. The number of turns of the 7th and 8th sub-coils is basically the same. The number of turns of the 9th and 10th sub-coils is basically the same. The above "basically the same" can be understood as completely identical or with a deviation of no more than 1%. After winding, reserve the upper and lower ends of each sub-coil for use as upper and lower lead wires for connection. At the same time, lead wires out from the sub-coil at the corresponding positions to serve as the taps of the high-voltage coil.

[0049] Step 4: Wrap the outer surface of the first winding sub-coil column tightly with the first insulating layer 4, or place the air duct plate first and then set the first insulating layer 4. The air duct plate can be made of existing technology to form an axial air duct. Here, the first insulating layer 4 can be wrapped with insulating mesh cloth first and then tied with glass cloth tape. The two materials are combined to wrap it tightly.

[0050] Step 5: Repeat steps 2-3 on the outer surface of the first insulating layer 4 of the first sub-coil column until the winding of the second sub-coil column is completed;

[0051] Step 6: Take the upper leads of the 12th sub-coil in each sub-coil column, i.e., sub-coils numbered 1-12 and 2-12, as the upper ends of two wires. Connect the upper ends of these two wires in parallel to form the head 1 of the high-voltage coil. Take the lower leads of the first sub-coil in each sub-coil column, i.e., sub-coils numbered 1-1 and 2-1, as the lower ends of two wires. Connect the lower ends of these two wires in parallel to form the tail 2 of the high-voltage coil. Sub-coils numbered 2-2, 2-3, 1-4, 1-5, 2-6, 2-7, 1-8, 1-9, 2-10, 2-11, and 1-12 are connected in series from bottom to top. Sub-coils numbered 2-1, 1-2, 1-3, 2-4, 2-5, 1-6, 1-7, 2-8, 2-9, 1-10, 1-11, and 2-12 are also connected in series from bottom to top. Based on the above description, the lead-out end between the lower coil group 6 and the upper coil group 7, that is, the one numbered 2... -6 and 2-7, and the output wires numbered 1-6 and 1-7, will not be connected in series for now. They will be connected in series as needed during use. Then, a branch output wire 3 will be formed by connecting the upper ends of sub-coils numbered 1-2 and 2-2 and the lower ends of sub-coils numbered 1-3 and 2-3 in parallel. Similarly, a branch output wire 3 will be formed by connecting the upper ends of sub-coils numbered 1-4 and 2-4 and the lower ends of sub-coils numbered 1-5 and 2-5 in parallel. The output wires numbered 1-6 and 2-... A branch line 3 is formed by connecting the upper end of sub-coil 6 in parallel; a branch line 3 is formed by connecting the lower end of sub-coil 1-7 and 2-7 in parallel; a branch line 3 is formed by connecting the upper end of sub-coil 1-8 and 2-8 and the lower end of sub-coil 1-9 and 2-9 in parallel; and a branch line 3 is formed by connecting the upper end of sub-coil 1-10 and 2-10 and the lower end of sub-coil 1-11 and 2-11 in parallel.

[0052] Step 7: The head 1, tail 2 and tap 3 of the high-voltage coil are wrapped with an insulator (using existing technology). Then, according to existing technology, an outer insulation layer is wrapped around the second sub-coil column. This outer insulation layer can be made of insulating mesh cloth and glass cloth tape wrapped tightly around the insulating mesh cloth, thus obtaining the required high-voltage coil.

[0053] Example 2

[0054] The structure and features of this embodiment are as follows: Figures 3-4As shown, the difference from Embodiment 1 is that the number of conductors is 3, and the number of sub-coil arrays is also changed accordingly. In this embodiment, the number of sub-coil columns distributed radially in the sub-coil array is three (i.e., n=3), and each column consists of 14 sub-coils (i.e., m=12) arranged axially. They are numbered in the same way as in Embodiment 1 above, with the first sub-coil column numbered from bottom to top as 1-1, 1-2, ..., 1-14, the second sub-coil column numbered from bottom to top as 2-1, 2-2, ..., 2-14, and the third sub-coil column numbered from bottom to top as 3-1, 3-2, ..., 3-14.

[0055] In this embodiment, the output ends of the three sub-coils numbered 1-14, 2-14, and 3-14 are connected in parallel to form the head 1 of the high-voltage coil; the output ends of the three sub-coils numbered 1-1, 2-1, and 3-1 are connected in parallel to form the tail 2 of the high-voltage coil.

[0056] In this embodiment, the specific configuration of the tap-out wire 3 is as follows: the sub-coils numbered 1-4, 1-5, 1-6, 1-7, 2-4, 2-5, 2-6, 2-7, 3-4, 3-5, 3-6, and 3-7 become the lower tap-out segments 6b from which three lower tap-out wires 3a are drawn. The three lower tap-out wires 3a are respectively obtained by drawing from the upper ends of the sub-coils numbered 1-3, 2-3, and 3-3 and the lower ends of the sub-coils numbered 1-4, 2-4, and 3-4 and connecting them in parallel; the upper ends of the sub-coils numbered 1-5, 2-5, and 3-5 and the lower ends of the sub-coils numbered 1-6, 2-6, and 3-6 and connecting them in parallel; and the upper ends of the sub-coils numbered 1-7, 2-7, and 3-7 are drawn from the upper ends and connected in parallel. The sub-coils numbered 1-8, 1-9, 1-10, 1-11, 2-8, 2-9, 2-10, 2-11, 3-8, 3-9, 3-10, and 3-11 become the upper branch segment 7b from which three upper branch wires 3b are led out. The three upper branch wires 3b are respectively led out from the lower end of the sub-coils numbered 1-8, 2-8, and 3-8 and connected in parallel; the upper end of the sub-coils numbered 1-9, 2-9, and 3-9 and the lower end of the sub-coils numbered 1-10, 2-10, and 3-10 are led out from the lower end of the sub-coils numbered 1-11, 2-11, and 3-11 and the lower end of the sub-coils numbered 1-12, 2-12, and 3-12 are led out from the lower end of the sub-coils numbered 1-12 and connected in parallel.

[0057] In this embodiment, the number of turns of the sub-coils is distributed as follows: the numbered sub-coils 1-1, 2-1, 3-1, 1-2, 2-2, 3-2, 1-3, 2-3, 3-3, 1-12, 2-12, 3-12, 1-13, 2-13, 3-13, 1-14, 2-14, and 3-14 have approximately the same number of turns; the numbered sub-coils 1-4, 2-4, 3-4, 1-5, 2-5, and 3-5 have approximately the same number of turns. The number of turns of the sub-coils numbered 1-6, 2-6, 3-6, 1-7, 2-7, and 3-7 are basically equal. The number of turns of the sub-coils numbered 1-8, 2-8, 3-8, 1-9, 2-9, and 3-9 are basically equal. The number of turns of the sub-coils numbered 1-10, 2-10, 3-10, 1-11, 2-11, and 3-11 are basically equal. Similarly, the above "basically the same" can be understood as being completely identical or having a deviation of no more than 1%.

[0058] In this embodiment, the specific series connection method of the sub-coils is as follows: sub-coils numbered 1-1, 2-2, 3-3, 3-4, 1-5, 1-6, 3-7, 3-8, 1-9, 1-10, 3-11, 3-12, 2-13, and 1-14 are connected in series sequentially; sub-coils numbered 2-1, 3-2, 1-3, 1-4, 3-5, 3-6, 1-7, 1-8, 3-9, 3-10, 1-11, 1-12, 3-13, and 2-14 are connected in series sequentially, and sub-coils numbered 3-1, 1-2, 2-3, 2-4, and 2-5 are connected in series sequentially. The sub-coils 2-6, 2-7, 2-8, 2-9, 2-10, 2-11, 2-12, 1-13, and 3-14 are connected in series. It should be noted that the outgoing wires between the lower coil group 6 and the upper coil group 7 (between 3-7 and 3-8, between 1-7 and 1-8, and between 2-7 and 2-8) are disconnected after winding. They are then reconnected as needed during use. This results in the high-voltage coil of the dry-type transformer in this embodiment being a structure in which three conductors of the same length are wound continuously and then connected in parallel.

[0059] The insulation configuration in this embodiment is as follows: a first insulating layer 4 is provided between the first sub-coil column and the second sub-coil column, or an axial air passage and a first insulating layer 4 located outside the axial air passage are provided between the first sub-coil column and the second sub-coil column; a first insulating layer 4 is also provided between the second sub-coil column and the third sub-coil column, or an axial air passage and a first insulating layer 4 located outside the axial air passage; a second insulating layer 5 is provided between sub-coils numbered 1-7, 2-7, and 3-7 and sub-coils numbered 1-8, 2-8, and 3-8; the insulation distance between each pair of the connecting lines 8 between sub-coils numbered 1-1 and 2-2, between sub-coils numbered 2-1 and 3-2, and between sub-coils numbered 3-1 and 1-2 is not less than 10mm; the insulation distance between each pair of the connecting lines 8 between sub-coils numbered 1-2 and 2-3 is not less than 10mm. The insulation distance between each pair of the connecting lines 8 between coils, the connecting lines 8 between sub-coils numbered 2-2 and 3-3, and the connecting lines 8 between sub-coils numbered 3-2 and 1-3 is not less than 10mm; the insulation distance between each pair of the connecting lines 8 between sub-coils numbered 1-12 and 3-13, and the connecting lines 8 between sub-coils numbered 3-12 and 2-13 is not less than 10mm; the insulation distance between each pair of the connecting lines 8 between sub-coils numbered 1-13 and 3-14 is not less than 10mm; an inner insulation layer is provided on the inner side of the three sub-coil rows, and an outer insulation layer is provided on the outer side of the three sub-coil rows.

[0060] The winding method in this embodiment includes the following steps:

[0061] Step 1: Tightly wrap the inner insulation layer on the coil mold. Specifically, first tightly wrap the required quantity and specifications of insulating mesh cloth on the coil mold, and then wrap the outer surface of the insulating mesh cloth with glass cloth tape to ensure that the insulating mesh cloth is tight and the surface is smooth.

[0062] Step 2: On the outer surface of the inner insulation layer, the first sub-coil at the bottom of the first sub-coil column, i.e., the sub-coil numbered 1-1, is wound in a continuous winding manner, and the upper and lower ends of the sub-coil are reserved as the upper and lower lead wires for connection.

[0063] Step 3: Repeat Step 2 on the sub-coil numbered 1-1, winding the second sub-coil in the first sub-coil column (i.e., sub-coil numbered 1-2) sequentially from bottom to top, until the 14th sub-coil in the first sub-coil column (i.e., sub-coil numbered 1-14) is completed. When half of the sub-coil is wound, place the second insulating layer 5 on the current sub-coil. The number of turns for the 1st, 2nd, 3rd, 12th, 13th, and 14th sub-coils in the first sub-coil column is approximately... The number of turns of the 4th and 5th sub-coils is basically the same, the number of turns of the 6th and 7th sub-coils is basically the same, the number of turns of the 8th and 9th sub-coils is basically the same, and the number of turns of the 10th and 11th sub-coils is basically the same. The above sameness can be understood as being completely identical or having a deviation of no more than 1%. After the winding is completed, the upper and lower ends of each sub-coil are reserved as the upper and lower lead wires for connection. At the same time, lead wires out from the sub-coils at the corresponding positions as the taps of the high-voltage coil.

[0064] Step 4: Wrap the outer surface of the first winding sub-coil column tightly with the first insulating layer 4, or place the air duct plate first and then set the first insulating layer 4. The air duct plate can be made of existing technology to form an axial air duct. Here, the first insulating layer 4 can be wrapped with insulating mesh cloth first and then tied with glass cloth tape. The two materials are combined to wrap it tightly.

[0065] Step 5: Repeat steps 2 to 4 on the outside of the first insulating layer 4 to continue winding until the winding of the second sub-coil column is completed, and wrap the first insulating layer 4 on the outer surface of the second sub-coil column, or first place an axial air channel on the outer surface of the second sub-coil column, and then wrap the first insulating layer 4 around the axial air channel.

[0066] Step 6: Repeat steps 2-3 on the outer surface of the first insulating layer 4 of the second sub-coil column until the winding of the third sub-coil column is completed;

[0067] Step 7: Take the upper lead of the 14th sub-coil in each sub-coil column (i.e., sub-coils numbered 1-14, 2-14, and 3-14) as the upper end of three wires. Connect these three wires in parallel to form the head 1 of the high-voltage coil. Take the lower lead of the first sub-coil in each sub-coil column (i.e., sub-coils numbered 1-1, 2-1, and 3-1) as the lower end of three wires. Connect these three wires in parallel to form the tail 2 of the high-voltage coil. The coils numbered 1-1, 2-2, 3-3, 3-4, 1-5, 1-6, 3-7, and 3-8... Sub-coils 1-9, 1-10, 3-11, 3-12, 2-13, and 1-14 are connected in series sequentially; sub-coils numbered 2-1, 2-2, 1-3, 1-4, 3-5, 3-6, 1-7, 1-8, 3-9, 3-10, 1-11, 1-12, 3-13, and 2-14 are connected in series sequentially; sub-coils numbered 3-1, 1-2, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, 2-9, 2-10, 2-11, 2-12, 1-13, and 3-14 are connected in series sequentially. Based on the above description, the lower coil group 6 and the upper... The output wires between coil group 7, namely the output wires numbered 3-7 and 3-8, 1-7 and 1-8, and 2-7 and 2-8, are not connected in series for now. They will be connected in series as needed during use. A branch output wire 3 is formed by connecting the upper ends of sub-coils numbered 1-3, 2-3, and 3-3 and the lower ends of sub-coils numbered 1-4, 2-4, and 3-4 in parallel. Similarly, a branch output wire 3 is formed by connecting the upper ends of sub-coils numbered 1-5, 2-5, and 3-5 and the lower ends of sub-coils numbered 1-6, 2-6, and 3-6 in parallel. The upper ends of sub-coils numbered 1-7, 2-7, and 3-7 are led out and connected in parallel to form a tap-out wire 3; the lower ends of sub-coils numbered 1-8, 2-8, and 3-8 are led out and connected in parallel to form a tap-out wire 3; the upper ends of sub-coils numbered 1-9, 2-9, and 3-9 and the lower ends of sub-coils numbered 1-10, 2-10, and 3-10 are led out and connected in parallel to form a tap-out wire 3; the upper ends of sub-coils numbered 1-11, 2-11, and 3-11 and the lower ends of sub-coils numbered 1-12, 2-12, and 3-12 are led out and connected in parallel to form a tap-out wire 3.

[0068] Step 8: The head 1, tail 2 and tap 3 of the high-voltage coil are wrapped with an insulator (using existing technology). Then, according to existing technology, an outer insulation layer is wrapped around the third sub-coil column. This outer insulation layer can be made of insulating mesh cloth and glass cloth tape wrapped tightly around the insulating mesh cloth, thus obtaining the required high-voltage coil.

[0069] Example 3

[0070] The structure and features of this embodiment are as follows: Figure 5As shown, the difference between this embodiment and Embodiment 2 is that the number of conductors is 4, and the number of sub-coil arrays is also changed accordingly. In this embodiment, the number of sub-coil columns distributed radially in the sub-coil array is four (i.e., n=4), and each column consists of 16 sub-coils (i.e., m=16) arranged axially. They are numbered in the same way as in Embodiment 1 above, with the first sub-coil column numbered from bottom to top as 1-1, 1-2, ..., 1-16, the second sub-coil column numbered from bottom to top as 2-1, 2-2, ..., 2-16, the third sub-coil column numbered from bottom to top as 3-1, 3-2, ..., 3-16, and the fourth sub-coil column numbered from bottom to top as 4-1, 4-2, ..., 4-16.

[0071] In this embodiment, the output ends of the four sub-coils numbered 1-16, 2-16, 3-16, and 4-16 serve as the upper ends of the four conductors, and the upper ends of the four conductors are connected in parallel to form the head 1 of the high-voltage coil; the output ends of the four sub-coils numbered 1-1, 2-1, 3-1, and 4-1 serve as the lower ends of the four conductors, and the lower ends of the four conductors are connected in parallel to form the tail 2 of the high-voltage coil.

[0072] In this embodiment, the specific configuration of the tap-out wire 3 is as follows: the sub-coils numbered 1-5, 1-6, 1-7, 1-8, 2-5, 2-6, 2-7, 2-8, 3-5, 3-6, 3-7, 3-8, 4-5, 4-6, 4-7, and 4-8 become the lower tap-out segments 6b from which three lower tap-out wires 3a are led out. The three lower tap-out wires 3a are respectively numbered 1-4, 2-4, and 3-4. The following methods are used to obtain sub-coils: 1) The upper end of sub-coil 4-4 and the lower end of sub-coils numbered 1-5, 2-5, 3-5, and 4-5 are connected in parallel; 2) The upper end of sub-coils numbered 1-6, 2-6, 3-6, and 4-6 and the lower end of sub-coils numbered 1-7, 2-7, 3-7, and 4-7 are connected in parallel; 3) The upper end of sub-coils numbered 1-8, 2-8, 3-8, and 4-8 are connected in parallel; 4) The numbered 1 The sub-coils numbered -9, 1-10, 1-11, 1-12, 2-9, 2-10, 2-11, 2-12, 3-9, 3-10, 3-11, 3-12, 4-9, 4-10, 4-11, and 4-12 form the upper branch segment 7b from which three upper branch wires 3b are led out. The three upper branch wires 3b are respectively led out from the lower ends of the sub-coils numbered 1-9, 2-9, 3-9, and 4-9. The sub-coils numbered 1-10, 2-10, 3-10, and 4-10 are connected in parallel and their upper ends and the sub-coils numbered 1-11, 2-11, 3-11, and 4-11 are connected in parallel and their lower ends are connected in parallel and their upper ends and the sub-coils numbered 1-12, 2-12, 3-12, and 4-12 are connected in parallel and their lower ends are connected in parallel and their lower ends are connected in parallel.

[0073] The number of turns of the sub-coils in this embodiment is distributed as follows: the sub-coils numbered 1-1, 2-1, 3-1, 4-1, 1-2, 2-2, 3-2, 4-2, 1-3, 2-3, 3-3, 4-3, 1-4, 2-4, 3-4, 4-4, 1-13, 2-13, 3-13, 4-13, 1-14, 2-14, 3-14, 4-14, 1-15, 2-15, 3-15, 4-15, 1-16, 2-16, 3-16, and 4-16 have approximately the same number of turns; the sub-coils numbered 1-5, 2-5, 3-5, 4-5, 1-6, 2 The number of turns in sub-coils -6, 3-6, and 4-6 is basically equal. The number of turns in sub-coils numbered 1-7, 2-7, 3-7, 4-7, 1-8, 2-8, 3-8, and 4-8 is basically equal. The number of turns in sub-coils numbered 1-9, 2-9, 3-9, 4-9, 1-10, 2-10, 3-10, and 4-10 is basically equal. The number of turns in sub-coils numbered 1-11, 2-11, 3-11, 4-11, 1-12, 2-12, 3-12, and 4-12 is basically equal. Similarly, "basically equal" can be understood as being completely identical or having a deviation of no more than 1%.

[0074] In this embodiment, the specific series connection method of the sub-coils is as follows: sub-coils numbered 1-1, 3-2, 2-3, 4-4, 4-5, 1-6, 1-7, 4-8, 4-9, 1-10, 1-11, 4-12, 4-13, 2-14, 3-15, 1-16 are connected in series sequentially; sub-coils numbered 2-1, 4-2, 1-3, 3-4, 3-5, 2-6, 2-7, 3-8, 3-9, 2-10, 2-11, 3-12, 3-13, 1-14, 4-15, 2-16 are connected in series sequentially; sub-coils numbered 3-1, 1-2, 4-3, 2-4, 2-5, 3-6, 3-7, 2-8, 2-9, 3-10, 3-11, 2-12, 2-13, 4-14, 1- Sub-coils 15 and 3-16 are connected in series sequentially. Sub-coils numbered 4-1, 2-2, 3-3, 1-4, 1-5, 4-6, 4-7, 1-8, 1-9, 4-10, 4-11, 1-12, 1-13, 3-14, 2-15, and 4-16 are also connected in series sequentially. It should also be noted that the outgoing wires between the lower coil group 6 and the upper coil group 7 (between numbered 4-8 and 4-9, between numbered 3-8 and 3-9, between numbered 2-8 and 2-9, and between numbered 1-8 and 1-9) are disconnected after winding. They are reconnected as needed during use. This makes the high-voltage coil of the dry-type transformer in this embodiment a structure in which four wires of the same length are wound continuously and then connected in parallel.

[0075] The insulation configuration in this embodiment is as follows: a first insulating layer 4 is provided between the first sub-coil column and the second sub-coil column, or an axial air passage and a first insulating layer 4 located outside the axial air passage are provided between the first and second sub-coil columns; a first insulating layer 4 is provided between the second and third sub-coil columns, or an axial air passage and a first insulating layer 4 located outside the axial air passage are provided between the second and third sub-coil columns; similarly, a first insulating layer 4 is provided between the third and fourth sub-coil columns, or an axial air passage and a first insulating layer 4 located outside the axial air passage are provided between the third and fourth sub-coil columns; numbered 1-8, 2-8, 3 A second insulation layer 5 is provided between sub-coils numbered -8 and 4-8 and sub-coils numbered 1-9, 2-9, 3-9, and 4-9; the mutual insulation distance between each pair of the connecting lines 8 between sub-coils numbered 1-1 and 3-2, between sub-coils numbered 2-1 and 4-2, between sub-coils numbered 3-1 and 1-2, and between sub-coils numbered 4-1 and 2-2 is not less than 10 mm; the mutual insulation distance between each pair of the four connecting lines 8 between the remaining upper and lower adjacent sub-coils in the lower basic segment 6a and the upper basic segment 7a is not less than 10 mm; an inner insulation layer is provided on the inner side of the four sub-coil columns, and an outer insulation layer is provided on the outer side of the four sub-coil columns.

[0076] The winding method in this embodiment will not be described in detail; it can be wound in a regular manner according to the changes in the structure.

[0077] Example 4

[0078] The structure and features of this embodiment are as follows: Figure 6 As shown, the difference between this embodiment and Embodiment 1 is that the upper coil group 7 and the lower coil group 6 constitute a coil group. This coil group has two subgroups, which are distributed axially to form a first coil group 9a and a second coil group 9b. The winding directions of the coils in the first coil group 9a and the second coil group 9b are opposite, equivalent to symmetrical distribution along the radial line. This allows the beginnings of the first coil group 9a and the second coil group 9b to be adjacent and connected in parallel, forming the beginning 1 of the high-voltage coil in the middle. The end of the first coil group 9a becomes the first end 2a of the high-voltage coil, and the end of the second coil group 9b becomes the second end 2b of the high-voltage coil. The structure of the first coil group 9a is the same as that of Embodiment 1, while the structure of the second coil group 9b is symmetrical to that of Embodiment 1.

[0079] Example 5

[0080] The structure and features of this embodiment are as follows: Figure 7As shown, the difference between this embodiment and Embodiment 2 is that the upper coil group 7 and the lower coil group 6 constitute a coil group. This coil group has two subgroups, which are distributed axially to form a first coil group 9a and a second coil group 9b. Similar to Embodiment 4, the winding directions of the first coil group 9a and the second coil group 9b are opposite, equivalent to their symmetrical distribution along the radial line. This results in the beginning of the first coil group 9a and the beginning of the second coil group 9b being adjacent and connected in parallel to form the beginning 1 of the high-voltage coil in the middle. The end of the first coil group 9a becomes the first end 2a of the high-voltage coil, and the end of the second coil group 9b becomes the second end 2b of the high-voltage coil. The structure of the first coil group 9a is the same as that of Embodiment 2, and the structure of the second coil group 9b is symmetrical to that of Embodiment 2.

[0081] Example 6

[0082] The structure and features of this embodiment are as follows: Figure 8 As shown, the difference between this embodiment and Embodiment 3 is that the upper coil group 7 and the lower coil group 6 constitute a coil subgroup. This coil subgroup has two subgroups, which are distributed axially to form a first coil subgroup 9a and a second coil subgroup 9b. Similar to Embodiment 4, the winding directions of the first coil subgroup 9a and the second coil subgroup 9b are opposite, equivalent to their symmetrical distribution along the radial line. This results in the beginning of the first coil subgroup 9a and the beginning of the second coil subgroup 9b being adjacent and connected in parallel to form the beginning 1 of the high-voltage coil in the middle. The end of the first coil subgroup 9a becomes the first end 2a of the high-voltage coil, and the end of the second coil subgroup 9b becomes the second end 2b of the high-voltage coil. The structure of the first coil subgroup 9a is the same as that of Embodiment 3, while the structure of the second coil subgroup 9b is symmetrical to that of Embodiment 3.

[0083] Besides the preferred embodiment described above, the number of conductors can also be other numbers, such as 5, 6, or 7, which can be selected according to the voltage level of the high-voltage transformer coil. Furthermore, the transposition method described above is only one embodiment; conventional cross transposition and other even-numbered cross transpositions can also be used, and therefore such schemes also fall within the protection scope of this invention.

Claims

1. A high-voltage coil of a dry-type transformer, comprising: n A conductor, characterized in that Should n Each conductor is formed by sequentially connecting corresponding sub-coils from the following sub-coil array: the sub-coil array includes sub-coils arranged radially in sequence. n Each sub-coil column consists of [number] sub-coil columns, and each sub-coil column is further composed of [number] sub-coil columns. m The individual coils are arranged sequentially along the axial direction. n, m Each of the sub-coils is a positive integer not less than 2, and each sub-coil is made of a single insulated conductor wound in a continuous structure, with the conductor specifications of each sub-coil being the same. n The top end of each sub-coil in the sub-coil array becomes one end of each conductor, and the ends of each conductor are connected in parallel to form the beginning of the high-voltage coil (1). n The lower ends of the bottommost sub-coil in the sub-coil array become the other ends of each conductor, and the other ends of each conductor are connected in parallel to form the tail end (2) of the high-voltage coil; at the same time, the upper end of any of the bottommost sub-coils is connected in series along the axial direction to one of the sub-coils in the same radial direction through the connecting line (8), and then connected to the lower end of one of the topmost sub-coils, so that the high-voltage coil is formed by the same length and the same cross-section of the sub-coil. n The structure consists of three wires that are wound continuously and then connected in parallel. At the same time, taps are led out from each sub-coil in the same radial direction at the corresponding position. The taps are connected in parallel to each other and serve as the taps of the high-voltage coil (3).

2. The high-voltage coil of the dry-type transformer according to claim 1, characterized in that: The n A first insulating layer (4) is provided between adjacent sub-coil columns in each sub-coil column; Or, the n An axial air passage and a first insulating layer (4) placed outside the axial air passage are provided between adjacent sub-coil rows.

3. The high-voltage coil of the dry-type transformer according to claim 1, characterized in that: The n Each sub-coil array is further divided into a lower coil group (6) and an upper coil group (7) along the axial direction. A second insulating layer (5) is provided between the lower and upper coil groups (6, 7). The upper sub-coil in the lower coil group (6) becomes the lower tap section (6b) from which three lower tap leads (3a) are led out. The remaining sub-coils in the lower coil group (6) become the lower basic section (6a). The lower sub-coil in the upper coil group (7) becomes the upper tap section (7b) from which three upper tap leads (3b) are led out. The remaining sub-coils in the upper coil group (7) become the upper basic section (7a). The lower and upper tap leads (3a, 3b) are the tap leads (3) of the high-voltage coil.

4. The high-voltage coil of the dry-type transformer according to claim 3, characterized in that: The number of turns of each sub-coil in the lower basic segment (6a) and the upper basic segment (7a) is equal.

5. The high-voltage coil of the dry-type transformer according to claim 4, characterized in that: In the lower basic segment (6a) and the upper basic segment (7a), each sub-coil column has, in the axial direction, n Sub-coil.

6. The high-voltage coil of the dry-type transformer according to claim 3, characterized in that: In the lower and upper tap sections (6b, 7b), the corresponding sub-coil leads out from the middle number of turns between adjacent taps.

7. The high-voltage coil of the dry-type transformer according to claim 3, characterized in that: In the lower basic segment (6a) and the upper basic segment (7a), the upper and lower adjacent sub-coils respectively have n Root connecting line (8), n The insulation distance between the connecting wires in the root connecting wire (8) shall not be less than 10mm.

8. The high-voltage coil of the dry-type transformer according to any one of claims 3 to 5, characterized in that: The upper coil group (7) and the lower coil group (6) constitute a coil group, and the coil group has two groups, which are distributed along the axial direction to form a first coil group (9a) and a second coil group (9b). The coil winding directions of the first coil group (9a) and the second coil group (9b) are opposite, so that the beginning of the first coil group (9a) and the beginning of the second coil group (9b) are adjacent and connected in parallel to form the beginning (1) of the high voltage coil in the middle. The end of the first coil group (9a) becomes the first end (2a) of the high voltage coil, and the end of the second coil group (9b) becomes the second end (2b) of the high voltage coil.

9. The high-voltage coil of the dry-type transformer according to claim 2, characterized in that: The n An inner insulating layer is provided on the inner side of each sub-coil array, the n Each sub-coil array has an outer insulating layer on its outer side.

10. A method for winding the high-voltage coil of a dry-type transformer as described in claim 9, characterized in that, Includes the following steps: Step 1: The inner insulation layer is tightly wrapped around the coil mold; Step 2: On the outer surface of the inner insulation layer, the first sub-coil at the bottom of the first sub-coil column is wound in a continuous winding manner, and the upper and lower ends of the first sub-coil are reserved as the upper and lower lead wires for connection. Step 3: Repeat Step 2 on the first sub-coil, winding the second sub-coil in the first sub-coil column from bottom to top, until the first sub-coil column is completed. m Each sub-coil has its upper and lower ends reserved for connection, and wires are led out from the corresponding sub-coil to serve as the taps for the high-voltage coil. Step 4: Securely wrap the outer surface of the first wound sub-coil array with the first insulating layer (4), or first place an axial air passage on the outer surface of the first wound sub-coil array, and then wrap the first insulating layer (4) around the axial air passage; if n If = 2, proceed to step 6; if n If the value is ≥3, proceed to step 5; Step 5: Repeat steps 2-4 on the outside of the first insulating layer (4) to continue winding until the first insulating layer is completed. n -1 sub-coil column winding, and wrap the first n -1 The first insulating layer (4) on the outer surface of the sub-coil column or in the first n -1 An axial air passage is first placed on the outer surface of the sub-coil array, and then the first insulating layer (4) is wrapped around the axial air passage; Step 6, then in the above-mentioned section... n - Repeat steps 2-3 on the outer surface of the first insulating layer (4) of the sub-coil column until the first insulating layer is completed. n Winding of layered coils; Step 7, select the first sub-coil from each sub-coil column. m The upper leads of each sub-coil are connected in parallel to form the beginning of the high-voltage coil (1); the lower leads of the first sub-coil in each sub-coil column are connected in parallel to form the end of the high-voltage coil (2); the lower leads of the first sub-coil in each sub-coil column are connected in parallel to form the end of the high-voltage coil (2); m The lower lead of each sub-coil is connected in series along the axial direction downwards via connecting wire (8) to one of the sub-coils on the same radial direction, and then connected to... n The upper lead of one of the first sub-coils in each sub-coil array is connected to ensure that the series connection forms a... n The conductors have the same length and the same cross-section; at the same time n The taps of the sub-coils in the same radial direction in the sub-coil array are connected in parallel to each other, so that they become the corresponding taps of the high-voltage coil (3); Step 8, in the n After wrapping the outer insulation layer around each sub-coil, leave out and fix the beginning (1), end (2) and tap end (3) of the high-voltage coil.

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