A three-dimensional wound core transformer lead structure

Abstract

The utility model relates to transformer technical field, concretely is a kind of three-dimensional volume iron core transformer lead structure, including a phase coil, b phase coil and c phase coil, a phase coil, b phase coil and c phase coil three are equilateral triangle setting, and in the process of coil winding, it is wound more 1 / 3 turns to a phase coil, b, c phase coil is wound less 1 / 3 turns, the upper left corner of b phase coil is equipped with b phase head row, and the upper right corner is equipped with b phase tail row, the upper left corner of c phase coil is equipped with c phase tail row, and lower part is equipped with c phase head row, the lower part of a phase coil is equipped with a phase head row, and the upper right corner is equipped with a phase tail row, the included angle between all head, tail is 120 °, box cover is provided above coil, and 0 phase horizontal row is provided between a phase coil and c phase coil, the utility model can be connected by the arrangement and lead of low voltage bushing, without increasing lead copper bar section, secondly, the resistance of a, b, c phase coil can be kept basically consistent.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, specifically to a three-dimensional wound core transformer lead structure. Background Technology

[0002] The national standard GB / T 6451-2023, "Technical Parameters and Requirements for Oil-Immersed Power Transformers," stipulates that "for distribution transformers: the phase resistance imbalance rate should not exceed 4%, and the line resistance imbalance rate should not exceed 2%." While these values ​​can be exceeded due to factors such as wire material and lead structure, most user tender documents currently require these values ​​to be kept within limits. Even the State Grid and Southern Power Grid, which have the largest tender volumes, require these values ​​in their technical specifications for procuring three-dimensional wound core distribution transformers. The three-phase coils of a three-dimensional wound core are arranged in an equilateral triangle. Due to its inherent structure, the starting and ending copper busbars of the low-voltage b-phase coil need to be connected to the low-voltage bushing on the front side. The resistance of this connection leads to both the phase resistance and line resistance of the b-phase being greater than those of the a and c phases. Furthermore, the larger the transformer capacity, the greater the imbalance rate. Currently, the only way to reduce the b-phase resistance is to increase the cross-section of the b-phase lead copper busbar, which is not only costly but also ineffective. Utility Model Content

[0003] The purpose of this invention is to provide a three-dimensional wound core transformer lead structure to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a three-dimensional wound core transformer lead wire structure, including an a-phase coil, a b-phase coil, and a c-phase coil, wherein the a-phase coil, b-phase coil, and c-phase coil are arranged in an equilateral triangle, and during the coil winding process, the a-phase coil has 1 / 3 more turns than the b-phase coil and the c-phase coils have 1 / 3 fewer turns than the b-phase coil.

[0005] The upper left corner of the b-phase coil has a b-phase starting row, and the upper right corner has a b-phase ending row. The upper left corner of the c-phase coil has a c-phase ending row, and the lower part has a c-phase starting row. The lower part of the a-phase coil has an a-phase starting row, and the upper right corner has an a-phase ending row. The included angle between all the starting and ending rows is 120°.

[0006] A box cover is installed above the coil. A 0-phase horizontal row is installed between the a-phase coil and the c-phase coil. Four low-voltage phase bushings are installed above the box cover. A b-phase soft copper sheet is installed between the b-phase starting row and the low-voltage phase bushing. The b-phase ending row is connected to the 0-phase horizontal row. The two ends of the 0-phase horizontal row are bent at 90°. The horizontal length is approximately equal to the distance between the a-phase and c-phase ending rows. The a-phase and c-phase ending rows are diagonally connected to the 0-phase horizontal row at the bend. A 0-phase soft copper sheet is installed between the 0-phase horizontal row and the low-voltage phase bushing. The c-phase starting row is directly connected to the low-voltage phase bushing through the soft copper sheet. The a-phase starting row is connected to the low-voltage phase bushing through the soft copper sheet.

[0007] Phase 0 is arranged horizontally and phase b is arranged vertically, with an insulating pad between them, and they are fixed with cable ties.

[0008] Preferably, the upper end of the low-voltage phase bushing is provided with an outlet end, the four low-voltage phase bushings are staggered, and the low-voltage phase bushing connected to the a-phase coil and the c-phase coil is at the front, while the low-voltage phase bushing connected to the b-phase coil and the 0-phase coil in a horizontal row is at the rear, and the four low-voltage phase bushings are arranged in a parallelogram.

[0009] Preferably, the a-phase drop row consists of a fixed body, a limiting piece, and a positioning recess. The side view of the fixed body is a triangular structure. The upper end of the fixed body is fixedly connected to the limiting piece, and the side end of the limiting piece abuts against the 0-phase horizontal row.

[0010] Preferably, a positioning block is fixedly connected to the side end, the front and rear ends of the positioning block are horizontal planes, the left and right ends of the positioning block are arc-shaped planes, and the positioning block is engaged in the positioning recess.

[0011] Preferably, the front end of the positioning block is provided with a locking piece, the two sides of the locking piece are inclined structures, the two ends of the locking piece abut against the inner wall of the positioning recess, and a fixing bolt is provided in the middle of the positioning recess. The fixing bolt passes through the locking piece and is threadedly connected to the positioning block.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. By using the above winding method, the resistance of phase a coil can be increased and the resistance of phase b and c coils can be decreased. The phase a coil has a resistance of about 2 / 3 more turns than the phase b and c coils. Moreover, only one set of gear molds is needed to make all three phase coils usable.

[0014] 2. By arranging the low-voltage bushings and connecting the leads, the lead resistance of phase B is minimized without increasing the cross-section of the lead copper busbar. Secondly, the phase and line resistances of phases A and C can be kept basically consistent, reducing the difference between the resistances of phase B and phases A and C. Ultimately, the phase and line resistance imbalance rate of the three phases of the transformer can be controlled within the standard range, and the eddy current loss generated by the large current in the low-voltage bushing at the tank cover is also reduced.

[0015] 3. In the manufacturing process of the transformer, the amount of copper foil for the low-voltage coil and copper busbars for the leads is reduced, and the lead arrangement is simple and convenient to operate. Attached Figure Description

[0016] Figure 1 This is a top view of the low-voltage lead wire.

[0017] Figure 2 This is a top view of the low-pressure landing head.

[0018] Figure 3 This is a front view of the low-voltage lead.

[0019] Figure 4 Left view of the low-voltage lead.

[0020] Figure 5 This is a schematic diagram showing the connection between phase a (head row) and phase 0 (horizontal row).

[0021] In the diagram: 1b phase starting row, 2b phase ending row, 3 insulating pad, 40 phase horizontal row, 50 phase soft copper sheet, 6a phase starting row, 7c phase ending row, 8c phase starting row, 9a phase ending row, 91 fixing body, 92 limiting piece, 93 positioning recess, 10 fixing bolt, 11 low voltage phase bushing, 12 box cover, 13 outgoing terminal, 14b phase soft copper sheet, 15 positioning block, 17 locking piece. Detailed Implementation

[0022] To enhance understanding of this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described and introduced below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this utility model, not all embodiments, and are not intended to limit the embodiments in any way. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0023] Please see Figure 1-5This utility model provides a technical solution: a three-dimensional wound core transformer lead structure, including an a-phase coil, a b-phase coil, and a c-phase coil. The a-phase coil, b-phase coil, and c-phase coil are arranged in an equilateral triangle. During the coil winding process, the a-phase coil has 1 / 3 more turns, while the b-phase and c-phase coils have 1 / 3 fewer turns, increasing the resistance of the a-phase coil and decreasing the resistance of the b-phase and c-phase coils. The three-phase leads are designed to be of similar length to achieve three-phase resistance balance. The b-phase coil has a b-phase starting row 1 at the upper left corner and a b-phase ending row 2 at the upper right corner. The c-phase coil has a c-phase ending row 7 at the upper left corner and a c-phase starting row 8 at the bottom. The a-phase coil has an a-phase starting row 6 at the bottom and an a-phase ending row 9 at the upper right corner. The included angles between the starting and ending rows differ by 120° to facilitate coil winding. A cover 12 is provided above the coils. A 0-phase horizontal row 4 is provided between the A-phase coil and the C-phase coil. Four low-voltage phase bushings 11 are provided above the cover 12. A B-phase soft copper sheet 14 is provided between the B-phase starting row 1 and the low-voltage phase bushing 11. The B-phase ending row 2 is connected to the 0-phase horizontal row 4. The two ends of the 0-phase horizontal row 4 are bent at 90°. The horizontal length is approximately equal to the distance between the A-phase ending row 9 and the C-phase ending row 7. The A-phase ending row 9 and the C-phase ending row 7 are diagonally connected to the 0-phase horizontal row 4 at the bend. A 0-phase soft copper sheet 5 is provided between the 0-phase horizontal row 4 and the low-voltage phase bushing 11. The C-phase starting row 8 is directly connected to the low-voltage phase bushing 11 through the soft copper sheet. The A-phase starting row 6 is connected to the low-voltage phase bushing 11 through the soft copper sheet. The 0-phase horizontal row 4 and the B-phase starting row 1 are arranged vertically. An insulating pad 3 is provided between them. The insulating pad 3 is used for limiting the position and is fixed by binding straps to make the two a solid whole.

[0024] The upper end of the low-voltage phase bushing 11 is provided with a line outlet 13. The four low-voltage phase bushings 11 are staggered, with the low-voltage phase bushing 11 connected to the a-phase coil and the c-phase coil being at the front, and the low-voltage phase bushing 11 connected to the b-phase coil and the 0-phase horizontal row 4 being at the rear. The four low-voltage phase bushings 11 are arranged in a parallelogram.

[0025] The phase A drop bar 9 consists of a fixed body 91, a limiting piece 92, and a positioning recess 93. The side view of the fixed body 91 is a triangular structure. The upper end of the fixed body 91 is fixedly connected to the limiting piece 92. The side end of the limiting piece 92 abuts against the phase 0 horizontal bar 4. The positioning recess 93 is located in the middle of the limiting piece 92 and has an arc-shaped structure. The side end of the phase 0 horizontal bar 4 is fixedly connected to a positioning block 15. The front and rear ends of the positioning block 15 are horizontal surfaces, and the left and right ends of the positioning block 15 are arc-shaped surfaces. The positioning block 15 is engaged in the positioning recess 93, so that the phase A drop bar 9 can be positioned and engaged with the phase 0 horizontal bar 4, while ensuring the contact area between the two so that the current can flow smoothly. During installation, the fixed body 91 can block the phase 0 horizontal bar 4, thereby positioning the installation of the phase 0 horizontal bar 4.

[0026] The front end of the positioning block 15 is provided with a locking piece 17. The two sides of the locking piece 17 are inclined structures. The two ends of the locking piece 17 abut against the inner wall of the positioning recess 93. The middle of the positioning recess 93 is provided with a fixing bolt 10. The fixing bolt 10 passes through the locking piece 17 and is threadedly connected to the positioning block 15. When the fixing bolt 10 is turned, the locking piece 17 can block and position the positioning block 15, so as to prevent the positioning block 15 from being driven by the fixing bolt 10 to cause large compression to the positioning recess 93 and to prevent the positioning recess 93 from undergoing large deformation.

[0027] Although embodiments of the present invention have been shown and described, it should be emphasized that the above description is merely an introduction and description of the usage of the embodiments of the present invention, and is not intended to limit the present invention in any way. Those skilled in the art will understand that various changes, modifications, substitutions, and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional wound core transformer lead structure, comprising an a-phase coil, a b-phase coil, and a c-phase coil, characterized in that: The phase a coil, phase b coil, and phase c coil are arranged in an equilateral triangle. During the coil winding process, the phase a coil is wound with 1 / 3 more turns, while the phase b and phase c coils are wound with 1 / 3 fewer turns. The upper left corner of the b-phase coil has a b-phase starting row (1), and the upper right corner has a b-phase ending row (2). The upper left corner of the c-phase coil has a c-phase ending row (7), and the lower part has a c-phase starting row (8). The lower part of the a-phase coil has an a-phase starting row (6), and the upper right corner has an a-phase ending row (9). The included angle between all the starting and ending points is 120°. A box cover (12) is provided above the coil. A 0-phase horizontal row (4) is provided between the a-phase coil and the c-phase coil. Four low-voltage phase bushings (11) are provided above the box cover (12). A b-phase soft copper sheet (14) is provided between the b-phase starting row (1) and the low-voltage phase bushing (11). The b-phase falling row (2) is connected to the 0-phase horizontal row (4). The two ends of the 0-phase horizontal row (4) are bent at 90°. The horizontal length is approximately equal to the distance between the a-phase falling row (9) and the c-phase falling row (7). The a-phase falling row (9) and the c-phase falling row (7) are connected obliquely to the bend of the 0-phase horizontal row (4). A 0-phase soft copper sheet (5) is provided between the 0-phase horizontal row (4) and the low-voltage phase bushing (11). The c-phase starting row (8) is directly connected to the low-voltage phase bushing (11) through the soft copper sheet. The a-phase starting row (6) is connected to the low-voltage phase bushing (11) through the soft copper sheet. Phase 0 horizontal row (4) and phase b starting row (1) are arranged vertically, with an insulating pad (3) placed between them and fixed by a binding strap.

2. The three-dimensional volume core transformer lead structure according to claim 1, characterized in that: The upper end of the low-voltage phase bushing (11) is provided with a line outlet (13). The four low-voltage phase bushings (11) are staggered, and the low-voltage phase bushing (11) connected to the a-phase coil and the c-phase coil is in front, while the low-voltage phase bushing (11) connected to the b-phase coil and the 0-phase horizontal row (4) is in the back. The four low-voltage phase bushings (11) are arranged in a parallelogram.

3. The structure of the lead wire of the three-dimensional volume core transformer according to claim 1, characterized in that: The a-phase drop row (9) is composed of a fixed body (91), a limiting piece (92) and a positioning recess (93). The side view of the fixed body (91) is a triangular structure. The upper end of the fixed body (91) is fixedly connected to the limiting piece (92), and the side end of the limiting piece (92) abuts against the 0-phase horizontal row (4).

4. The structure of the lead wire of the three-dimensional volume core transformer according to claim 3, characterized in that: The positioning recess (93) is located in the middle of the limiting piece (92). The positioning recess (93) has an arc-shaped structure. The side end of the 0-phase horizontal row (4) is fixedly connected to a positioning block (15). The front and rear ends of the positioning block (15) are horizontal surfaces, and the left and right ends of the positioning block (15) are arc-shaped surfaces. The positioning block (15) is engaged in the positioning recess (93).

5. The three-dimensional volume core transformer lead structure of claim 4, wherein: The front end of the positioning block (15) is provided with a locking piece (17). The two sides of the locking piece (17) are inclined structures. The two ends of the locking piece (17) abut against the inner wall of the positioning recess (93). The middle of the positioning recess (93) is provided with a fixing bolt (10). The fixing bolt (10) passes through the locking piece (17) and is threadedly connected to the positioning block (15).

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