Copper bar transmission structure of low-voltage winding of power transformer

Abstract

The utility model discloses a copper bar transmission structure of a power transformer low-voltage winding. The utility model aims to solve the problems in the prior art that the overall magnetic field distribution of the low-voltage winding is non-uniform, the loss is larger, the winding difficulty is higher due to unsmooth winding, and the like. According to the technical scheme, the coil comprises a coil body, an inner copper bar and an outer copper bar, the inner copper bar and the outer copper bar are arranged at the inner top end and the outer top end of an arc-shaped bent part on one side of the cross section of the coil body respectively, the inner side end of the coil body is connected with the inner copper bar, and the outer side end of the coil body is connected with the outer copper bar. The radian of the section of the inner copper bar is the same as the radian of the inner top end section of the arc-shaped bending part on one side of the cross section of the coil, and the radian of the section of the outer copper bar is the same as the radian of the outer top end section of the arc-shaped bending part on one side of the cross section of the coil; the inner end of the coil is connected to the convex arc surface of the inner copper bar, and the outer end of the coil is connected to the concave arc surface of the outer copper bar.

Description

Technical Field

[0001] This utility model relates to the low-voltage winding structure of a power supply transformer, and in particular to a copper busbar transmission structure for the low-voltage winding of a power transformer. Background Technology

[0002] The copper busbar transmission structure of the low-voltage winding of a power transformer is the external connection terminal structure for the transformer's power output. The low-voltage winding generally includes a coil, an inner copper busbar connecting the inner end of the coil, and an outer copper busbar connecting the outer end of the coil. Due to other structural requirements of the power transformer, both the inner and outer copper busbars are located at the top of the arc-shaped bend on one side of the coil's cross-section. Currently, the cross-sections of the inner and outer copper busbars in the low-voltage windings of commonly used power transformers are straight. This causes the top section of the arc-shaped bend on one side of the coil's cross-section, which is attached to the inner copper busbar, to become a straight section after winding. Consequently, an angle appears at the connection between the straight section and the arc-shaped bends on both sides of the coil, resulting in uneven magnetic field distribution and increased losses in the overall low-voltage winding. The winding is also more difficult due to the lack of smoothness. On the other hand, the inner and outer ends of the coil are generally connected to the side of the inner and outer copper busbars facing away from the coil, respectively. This causes uneven layer spacing in the local area of ​​the coil, which also results in uneven magnetic field distribution and increased losses in the overall low-voltage winding, and the winding is also not smooth. Utility Model Content

[0003] In order to overcome the problems of uneven magnetic field distribution and large losses in the low-voltage winding of the existing technology, and the high difficulty of winding due to unsmooth winding, the purpose of this utility model is to provide an improved copper busbar transmission structure for the low-voltage winding of a power transformer, which can overcome the defects of the existing technology.

[0004] The technical solution adopted by this utility model to solve its technical problem is: a copper busbar transmission structure for a low-voltage winding of a power transformer, including a coil, an inner copper busbar, and an outer copper busbar, wherein the inner copper busbar and the outer copper busbar are respectively disposed at the inner and outer top ends of the arc-shaped bend on one side of the cross-section of the coil, the inner end of the coil is connected to the inner copper busbar, and its outer end is connected to the outer copper busbar, the coil is made of copper foil, characterized in that: the cross-sections of the inner copper busbar and the outer copper busbar are both arc-shaped bends, wherein the arc of the cross-section of the inner copper busbar is the same as the arc of the inner top end segment of the arc-shaped bend on one side of the cross-section of the coil, and the arc of the cross-section of the outer copper busbar is the same as the arc of the outer top end segment of the arc-shaped bend on one side of the cross-section of the coil, the inner end of the coil is connected to the convex arc surface of the inner copper busbar, and the outer end of the coil is connected to the concave arc surface of the outer copper busbar.

[0005] The connection between the inner end of the coil and the convex arc surface of the inner copper busbar described in the above technical solution can be achieved by entering the convex arc surface from one side of the inner copper busbar cross-section and abutting and crossing the entire convex arc surface, and then hooking onto the other side of the inner copper busbar cross-section; the connection between the outer end of the coil and the concave arc surface of the outer copper busbar can be achieved by entering the concave arc surface from one side of the outer copper busbar cross-section and abutting and crossing the entire concave arc surface, and then hooking onto the other side of the outer copper busbar cross-section.

[0006] The inner end of the coil and the inner copper busbar are connected to each other, and the outer end of the coil and the outer copper busbar are connected to each other, in the above technical solution. Argon arc welding or brazing can be used to fix the connecting surface of the inner end to the connecting surface of the inner copper busbar and the connecting surface of the outer end to the connecting surface of the outer copper busbar.

[0007] The gap between the copper foil layers of the coil described in the above technical solution can be padded with an insulating film or insulating paper as an insulating pad material, and can be filled with insulating varnish by impregnation process, or filled with epoxy resin mixture by vacuum dripping or differential pressure casting process; the outer surface of the low voltage winding can be made into a strong insulating protective shell by casting epoxy resin composite material.

[0008] The beneficial effects of this utility model are as follows: First, since the cross-sections of the inner and outer copper busbars are both arc-shaped, the arc of the inner copper busbar is the same as the arc of the inner top end of the arc-shaped bend on one side of the coil cross-section, and the arc of the outer copper busbar is the same as the arc of the outer top end of the arc-shaped bend on one side of the coil cross-section. Therefore, the top end of the arc-shaped bend on the side where the copper busbar is located can maintain the original arc of the arc-shaped bend after being wound along the inner copper busbar. In this way, no bends will appear on the entire coil, which can effectively improve the overall uniformity of the magnetic field distribution of the low-voltage winding, effectively reduce working losses, and at the same time, the winding of the coil becomes smoother and the winding difficulty is reduced. Secondly, since the inner end of the coil is connected to the convex arc surface of the inner copper busbar and the outer end of the coil is connected to the concave arc surface of the outer copper busbar, the coil no longer has dead angles with uneven local layer spacing between copper foil layers. This can further improve the overall uniformity of the magnetic field distribution of the low-voltage winding, further reduce working losses, and further improve the smoothness of the coil winding.

[0009] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the cross-section of the low-voltage winding of a current power transformer.

[0011] Figure 2This is a three-dimensional schematic diagram of one embodiment of the present invention.

[0012] Figure 3 yes Figure 2 A schematic diagram of its cross-section.

[0013] Figure 4 yes Figure 3 A magnified view of a portion at point A.

[0014] In the diagram: 1. Existing low-voltage winding; 2. Existing coil; 3. Existing inner copper busbar; 4. Existing outer copper busbar; 5. One side of the cross-section of the existing coil with an arc-shaped bend; 6. Existing inner end; 7. Existing outer end; 8. Bend one; 9. Bend two; 10. Coil; 11. Inner copper busbar; 12. Outer copper busbar; 13. One side of the cross-section of the coil with an arc-shaped bend; 14. Inner end; 15. Outer end; 16. The other side of the cross-section of the inner copper busbar; 17. The other side of the cross-section of the outer copper busbar; 18. Copper foil layer; 19. Gap; 20. Low-voltage winding; 21. Insulating protective shell. Detailed Implementation

[0015] like Figure 1 As shown, the existing low-voltage winding 1 of a prior art power transformer includes a prior art coil 2, a prior art inner copper busbar 3, and a prior art outer copper busbar 4. The prior art inner copper busbar 3 and the prior art outer copper busbar 4 are respectively located at the inner and outer top ends of the arc-shaped bend 5 on one side of the cross-section of the prior art coil. The prior art inner end 6 of the prior art coil 2 is connected to the prior art inner copper busbar 3, and the prior art outer end 7 is connected to the prior art outer copper busbar 4. The cross-sections of the prior art inner copper busbar 3 and the prior art outer copper busbar 4 are both straight, causing the top end of the arc-shaped bend 5 on one side of the cross-section of the prior art coil where the copper busbars are located to become a straight section after being wound along the prior art inner copper busbar 3. At the junction of the straight section and the curved sections on both sides of coil 2, bends 8 and 9 appear, causing uneven magnetic field distribution and increased losses in the existing low-voltage winding 1. The winding is also more difficult due to the unevenness of the straight section. On the other hand, the existing inner end 6 of the existing coil 2 is connected to the side of the existing inner copper busbar 3 facing away from the existing coil 2, and its existing outer end 7 is connected to the side of the existing outer copper busbar 4 facing away from the existing coil 2. This causes uneven layer spacing in the existing coil 2, which also causes uneven magnetic field distribution and increased losses in the existing low-voltage winding 1, and the winding is also not smooth.

[0016] Reference Figures 2-4This utility model discloses a copper busbar transmission structure for a low-voltage winding of a power transformer, comprising a coil 10, an inner copper busbar 11, and an outer copper busbar 12. The inner copper busbar 11 and the outer copper busbar 12 are respectively disposed at the inner and outer top ends of an arc-shaped bend 13 on one side of the cross-section of the coil. The inner end 14 of the coil 10 is connected to the inner copper busbar 11, and its outer end 15 is connected to the outer copper busbar 12. The coil 10 is made of copper foil. The characteristic feature is that the cross-sections of the inner copper busbar 11 and the outer copper busbar 12 are both arc-shaped bends. The arc of the cross-section of the inner copper busbar 11 is the same as the arc of the inner top end segment of the arc-shaped bend 13 on one side of the cross-section of the coil, and the arc of the cross-section of the outer copper busbar 12 is the same as the arc of the outer top end segment of the arc-shaped bend 13 on one side of the cross-section of the coil. The inner end 14 of the coil 10 is connected to the convex arc surface of the inner copper busbar 11, and the outer end 15 of the coil 10 is connected to the concave arc surface of the outer copper busbar 12.

[0017] In addition, such as Figure 4 As shown, the inner end 14 of the coil 10 is connected to the convex arc surface of the inner copper busbar 11 by entering the convex arc surface from one side of the cross-section of the inner copper busbar 11 and abutting and crossing the entire convex arc surface, and then hooking onto the other side 16 of the cross-section of the inner copper busbar; the outer end 15 of the coil 10 is connected to the concave arc surface of the outer copper busbar 12 by entering the concave arc surface from one side of the cross-section of the outer copper busbar 12 and abutting and crossing the entire concave arc surface, and then hooking onto the other side 17 of the cross-section of the outer copper busbar.

[0018] The inner end 14 of the coil 10 is connected to the inner copper busbar 11, and the outer end 15 of the coil 10 is connected to the outer copper busbar 12. Argon arc welding is used to fix the connecting surface of the inner end 14 to the connecting surface of the inner copper busbar 11, and the connecting surface of the outer end 15 to the connecting surface of the outer copper busbar 12.

[0019] The gaps 19 between the copper foil layers 18 of the coil 10 are all padded with insulating film or insulating paper as insulating padding material, and are filled with insulating varnish by impregnation process, or filled with epoxy resin mixture by vacuum dripping or differential pressure casting process; the outer surface of the low voltage winding 20 is formed into a strong insulating protective shell 21 by casting epoxy resin composite material.

[0020] like Figures 3-4 As shown, with the above improvements of this utility model, the arc-shaped bend 13 on one side of the coil cross-section with the inner copper busbar 11 and the outer copper busbar 12 does not have any bends, and the coil 10 does not have any uneven local layer spacing between the copper foil layers 18. This effectively improves the overall uniformity of the magnetic field distribution of the low-voltage winding 20, reduces its working loss, and makes winding smoother, thereby reducing the difficulty of winding.

Claims

1. A copper busbar transmission structure for a low-voltage winding of a power transformer, comprising a coil, an inner copper busbar, and an outer copper busbar, wherein the inner and outer copper busbars are respectively disposed at the inner and outer top ends of an arc-shaped bend on one side of the coil's cross-section, the inner end of the coil is connected to the inner copper busbar, and its outer end is connected to the outer copper busbar, the coil being made of copper foil, characterized in that: Both the inner and outer copper busbars have arc-shaped curved cross-sections. The arc of the inner copper busbar is the same as the arc of the inner top end of the arc-shaped curved portion on one side of the coil cross-section. The arc of the outer copper busbar is the same as the arc of the outer top end of the arc-shaped curved portion on one side of the coil cross-section. The inner end of the coil is connected to the convex arc surface of the inner copper busbar, and the outer end of the coil is connected to the concave arc surface of the outer copper busbar.

2. The copper busbar transmission structure of the low-voltage winding of the power transformer according to claim 1, characterized in that: The inner end of the coil connects to the convex arc surface of the inner copper busbar by entering the convex arc surface from one side of the inner copper busbar cross-section and abutting and crossing the entire convex arc surface, and then hooking onto the other side of the inner copper busbar cross-section; the outer end of the coil connects to the concave arc surface of the outer copper busbar by entering the concave arc surface from one side of the outer copper busbar cross-section and abutting and crossing the entire concave arc surface, and then hooking onto the other side of the outer copper busbar cross-section.

3. The copper busbar transmission structure of the low-voltage winding of the power transformer according to claim 1 or 2, characterized in that: The gaps between the copper foil layers of the coil are provided with insulating film or insulating paper as insulating padding material, and filled with an insulating varnish epoxy resin mixture.

4. The copper busbar transmission structure of the low-voltage winding of the power transformer according to claim 1 or 2, characterized in that: The outer surface of the low-voltage winding is made into an insulating protective shell by casting epoxy resin composite material.

Images