A prefabricated busbar, a preparation device thereof and a photovoltaic module
By setting a bend on the welding strip of the prefabricated busbar and using a special bending device, the problem of V-shaped microcracks caused by cell warping was solved, and stable welding of the welding strip in the photovoltaic module was achieved, avoiding damage to the cells.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-28
- Publication Date
- 2026-07-03
AI Technical Summary
When manufacturing photovoltaic modules with hidden busbars, after the prefabricated busbars and solar cells are welded, the warping of the solar cells causes the busbars to be pushed upwards. The solder strips exert an upward pulling force on the welding points on the solar cells, resulting in small V-shaped microcracks in the solar cells.
Design a prefabricated busbar, including a busbar and a welding strip, with a bend on the welding strip. The length and height of the bend are specifically designed so that the tension of the welding strip on the battery cell after welding is applied to the welding strip rather than the welding point, and the bending of the welding strip is achieved by a special bending device.
This design avoids V-shaped microcracks in the solar cells, prevents the solder ribbon from being easily cut during bending, adapts to the warping of the solar cells, and improves the welding reliability of photovoltaic modules.
Smart Images
Figure CN224460444U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic technology, specifically to a prefabricated busbar and its preparation device, and a photovoltaic module. Background Technology
[0002] Currently, in the fabrication of photovoltaic modules with concealed busbars, prefabricated busbars can be prepared, placed above the solar cells, and then the solder strips of the prefabricated busbars are welded onto the photovoltaic module. For example... Figure 1 As shown, the prefabricated busbar includes weld strips spaced parallel to each other along the extension direction of the busbar, and the weld strips are welded and fixed to the busbar. After the prefabricated busbar is welded to the battery cell, the inevitable warping of the battery cell will push the entire busbar upward, and the weld strips will exert an upward pulling force on the welding points on the battery cell, such as... Figure 2 As shown, this causes small V-shaped microcracks in the solar cell. Utility Model Content
[0003] To address the problems existing in the prior art, this utility model provides a prefabricated busbar and its preparation device, as well as a photovoltaic module.
[0004] On one hand, this utility model provides a prefabricated busbar, including a busbar and welding strips. The busbar is strip-shaped, and multiple parallel welding strips are arranged at intervals along the extension direction of the busbar. The welding strip includes a bent portion, and the busbar is located at the lower end of the bent portion and fixed to the bent portion. The length of the bent portion is not less than the width of the busbar, and the width of the bent portion is not less than the height of the busbar.
[0005] As a further improvement of this utility model, the length of the bent portion is 2mm to 4mm larger than the width of the busbar.
[0006] As a further improvement of this utility model, the height of the bent portion is between 0.3mm and 0.4mm.
[0007] As a further improvement of this utility model, the welding strip and the busbar are welded and fixed.
[0008] As a further improvement of this utility model, the bending portion includes a first bending area parallel to the main body of the welding strip and a transition area disposed on both sides of the first bending area, wherein the angle between the transition area and the main body of the welding strip is 110° to 160°.
[0009] On the other hand, this utility model provides a prefabricated busbar bending device for preparing the aforementioned busbar. The prefabricated busbar bending device includes an upper mold and a lower mold. The lower mold includes a lower mold body and a protrusion disposed on the lower mold body. The upper mold includes an upper mold body and a groove disposed on the upper mold body. The shapes of the groove and the protrusion are adapted to each other.
[0010] As a further improvement of this utility model, the length of the protrusion and the groove is not less than the length of the busbar.
[0011] As a further improvement of this utility model, the protrusion includes transition portions on both sides, and the included angle between the transition portions and the lower mold body is 110° to 160°.
[0012] On the other hand, this utility model provides a BC cell photovoltaic module with a hidden busbar. The welding strip of the prefabricated busbar is set above the busbar. The busbar is set between two adjacent cells. The main body of the welding strip contacts the welding point of the cell grid line. The welding strip and the cell grid line are welded and fixed at the welding point.
[0013] As a further improvement of this utility model, the BC cell photovoltaic module with hidden busbar includes multiple cell strings and the prefabricated busbar, wherein each of the multiple cell strings includes multiple cells connected in series along the X direction, the multiple cell strings are arranged in the Y direction on the photovoltaic module to form a group of cell strings, and at least two groups of cell strings are arranged in the X direction.
[0014] The battery cell includes alternating anisotropic first grid lines and second grid lines on the back side. The first grid lines are welded by a first solder strip, and the second grid lines are welded by a second solder strip. In a battery string, adjacent battery cells are welded by the first solder strip or by the second solder strip.
[0015] The prefabricated busbar includes an edge prefabricated busbar disposed at the edge in the X direction. The edge prefabricated busbar is disposed on two adjacent battery cells at the edge of the battery string and covers one or two adjacent battery strings in the Y direction.
[0016] The prefabricated busbar also includes an intermediate prefabricated busbar disposed between two adjacent battery strings in the X direction. The intermediate prefabricated busbar is disposed on two adjacent battery cells of the two adjacent battery strings and covers one or two adjacent battery strings in the Y direction.
[0017] It also includes an insulating layer disposed between the busbar and the battery cell. The insulating layer extends along the extension direction of the busbar, and the width of the insulating layer is not less than the width of the busbar, and its width does not exceed the welding point.
[0018] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.
[0019] In summary, the beneficial effects of the above-described technical solutions conceived by this utility model compared with the prior art include:
[0020] This invention incorporates a bent portion on the welding strip of the prefabricated busbar. After welding, the upward pulling force of the prefabricated busbar on the battery is applied to the welding strip rather than the welding point, thus preventing the welding point from cracking and avoiding small V-shaped microcracks in the battery cell.
[0021] The prefabricated busbar of this invention has a transition zone at the bend of the welding strip, which can prevent the welding strip from being cut during the bending process and can also accommodate the warping of the battery cells after welding. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0023] Figure 1 This is a schematic diagram of the structure of a prefabricated busbar in the prior art.
[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of a prefabricated busbar and the battery cells connected to it, based on existing technology.
[0025] Figure 3 This is a schematic diagram of the structure of a prefabricated busbar in one embodiment.
[0026] Figure 4 This is a schematic cross-sectional view of a prefabricated busbar according to one embodiment.
[0027] Figure 5 This is a schematic cross-sectional view of a prefabricated busbar according to one embodiment.
[0028] Figure 6 This is a schematic cross-sectional view of a prefabricated busbar according to one embodiment.
[0029] Figure 7 This is a schematic diagram of a prefabricated busbar bending device according to one embodiment.
[0030] Figure 8 This is a cross-sectional schematic diagram of a prefabricated busbar bending device according to one embodiment.
[0031] Figure 9 This is a partial schematic diagram of a photovoltaic module according to one embodiment.
[0032] Figure 10 This is a partial cross-sectional schematic diagram of a photovoltaic module according to one embodiment.
[0033] Figure 11 This is a partial cross-sectional schematic diagram of a photovoltaic module according to one embodiment.
[0034] Figure 12 This is a schematic diagram of a photovoltaic module according to one embodiment.
[0035] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: prefabricated busbar 10, busbar 11, welding strip 12, bending portion 121, welding strip body 122, first bending area 1211, transition area 1212, battery cell 2, battery string 200, upper mold 3, upper mold body 31, groove 32, lower mold 4, lower mold body 41, protrusion 42, insulating layer 5, existing prefabricated busbar 10A, existing busbar 11A, existing welding strip 12A, existing battery cell 2A, existing welding point 21A. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.
[0037] This invention aims to solve the problem in existing photovoltaic modules with concealed busbars where, after the prefabricated busbar and solar cell are welded, the solar cell warps, pushing the entire busbar upwards. This upward tension from the weld strips on the weld points on the solar cell causes small V-shaped microcracks in the cell. See also... Figure 1 and Figure 2 These are schematic diagrams of the structure of prefabricated busbars in the prior art, and cross-sectional schematic diagrams of the prefabricated busbars and the battery cells connected to them in the prior art.
[0038] See Figures 3 to 6 On the one hand, this application provides a prefabricated busbar 10, including a busbar 11 and welding strips 12. The busbar 11 is strip-shaped, and multiple parallel welding strips 12 are spaced apart along the extension direction of the busbar 11. The welding strips 12 are fixed to the busbar 11. Specifically, the welding strips can be fixed to the busbar by welding, bonding, or other methods. Preferably, the welding strips are welded to the busbar.
[0039] See Figure 3 ,in, Figure 3 This is a schematic diagram of the structure of a prefabricated busbar according to an embodiment of this application. The welding strip includes a bent portion 121, and the busbar 11 is located at the lower end of the bent portion 121 and fixed to the bent portion 121. The length L of the bent portion 121 is not less than the width of the busbar 11, and the height H of the bent portion 121 is greater than the thickness of the busbar 11.
[0040] Using the solution of this application, after welding, the upward pulling force of the prefabricated busbar on the battery acts on the welding strip, rather than on the welding point, so the welding point will not be cracked, thus avoiding small V-shaped microcracks in the battery cell.
[0041] In some preferred embodiments, the length of the bend 121 is 2mm to 4mm longer than the width of the busbar 11, and the height of the bend 121 is between 0.3mm and 0.4mm. This height is greater than the thickness of the busbar 11. In photovoltaic modules, insulating adhesive can be provided below to accommodate the thickness of the insulating adhesive. In this way, the main body of the solder strip can be just overlapped with the grid line of the cell with a small or no height difference.
[0042] Figure 5 and Figure 6 This is a cross-sectional schematic diagram of a prefabricated busbar according to an embodiment of this application. In a preferred embodiment, the prefabricated busbar of this application includes a welding strip 12 comprising a welding strip body 122, and a bending portion 121 comprising a first bending region 1211 parallel to the welding strip body 122 and transition regions 1212 disposed on both sides of the first bending region 1211. The included angle θ between the transition region 1212 and the welding strip body 122 is 110°–160°, preferably 130°–150°, and more preferably 135°.
[0043] By setting a transition zone, the welding strip can be prevented from being cut during bending.
[0044] On the other hand, this application provides a prefabricated busbar bending device for preparing prefabricated busbars with bent portions on the welding strip. See also Figure 7 and Figure 8 The figures shown are a structural schematic diagram and a cross-sectional schematic diagram of the prefabricated busbar bending device. The bending device of this application includes an upper die 3 and a lower die 4. The lower die 4 includes a lower die body 41 and a protrusion 42 disposed on the lower die body 41. The upper die 3 includes an upper die body 31 and a groove 32 disposed on the upper die body 31. The shapes of the groove 32 and the protrusion 42 are adapted to each other.
[0045] In use, the upper mold 3 and the lower mold 4 are separated, and the welding strip 12 is placed on the lower mold 4. Specifically, the extension direction of the welding strip 12 is perpendicular to the extension direction of the protrusion 42. Then, the upper mold 3 and the lower mold 4 are pressed together to form the bent part 121. Then, the upper mold 3 and the lower mold 4 are separated, and the bent welding strip 12 is removed. The bent welding strip 12 is then welded to the busbar 11 to obtain the prefabricated busbar 10.
[0046] In other embodiments, the protrusion 42 of the upper die 3 and the groove 32 of the lower die 4 are not less than the length of the busbar 11, which is suitable for bending the prefabricated busbar after welding the weld strip and the busbar. In use, the busbar 11 is set along the extension direction of the protrusion 42, and the weld strip 12 is perpendicular to the extension direction of the protrusion 42. Then, the upper die 3 and the lower die 4 are pressed together, and the weld strip 12 forms a bent part 121. Then, the upper die 3 and the lower die 4 are separated, and the prefabricated busbar can be taken out. In this way, all the weld strips of a prefabricated busbar can be bent simultaneously, and the bending consistency and accuracy of the weld strips can be guaranteed.
[0047] Using the prefabricated busbar bending device of this application, a prefabricated busbar with a bent portion of the weld strip can be obtained.
[0048] In order to prepare a solder strip with a transition zone, the bump 42 includes a transition portion, the angle between which and the lower die body 41 is 110° to 160°, preferably 130° to 150°, and more preferably 135°.
[0049] In some embodiments, the prefabricated busbar bending device further includes a drive module disposed on at least one of the upper mold 3 or the lower mold 4, which drives the upper mold 3 and the lower mold 4 to move closer or further away to complete the bending.
[0050] It should be noted that in this embodiment, the upper mold 3 and the lower mold 4 are only used to describe the cooperation relationship between the two, not the positional relationship. In use, the upper mold 3 can be on top or on the bottom, and the upper mold 3 and the lower mold 4 can also be set to the left and right, both of which can complete the bending function.
[0051] On the other hand, this application provides a BC-cell photovoltaic module with a hidden busbar including the aforementioned prefabricated busbar, comprising a prefabricated busbar. See also Figures 9 to 12 .in, Figure 9 This is a partial schematic diagram of a photovoltaic module; Figure 10 and Figure 11 This is a partial cross-sectional schematic diagram of a photovoltaic module. Among them, Figure 9 This diagram shows the connection between a prefabricated busbar and a solar cell. Figure 10 and Figure 11 These are cross-sectional schematic diagrams of the two implementation methods.
[0052] The welding strip 12 of the prefabricated busbar 10 is disposed above the busbar 11, the busbar 11 is disposed between two adjacent battery cells, the welding strip body 122 contacts the welding point of the battery cell grid line, and the welding strip 12 and the battery cell grid line are welded at the welding point.
[0053] In some implementations, such as Figure 11As shown, an insulating layer 5 is provided below the busbar 11. This insulating layer 5 is provided between the prefabricated busbar 10 and the battery cell 2 to avoid overlapping of the irregular grid lines on the busbar and the battery cell. As mentioned earlier, the setting that the height of the bend is greater than the thickness of the busbar allows the solder strip body to just overlap the grid line of the battery cell.
[0054] In the BC cell photovoltaic module with hidden busbars of this application, the upward pulling force of the prefabricated busbars on the cells is applied to the solder strips rather than the solder joints, thus preventing the solder joints from cracking and avoiding small V-shaped microcracks in the cells.
[0055] It should be noted that this application does not improve the photovoltaic module design with hidden busbars, but only improves the prefabricated busbar strips to solve the problem of small V-shaped microcracks in the solar cells. The module design, the series connection of the solder strips and solar cells, and the connection of the busbars and solder strips can all refer to existing technologies.
[0056] In one implementation, see Figure 12 This is a schematic diagram of a BC-cell photovoltaic module with a concealed busbar design. Details of the cell grid lines, solder ribbons, and prefabricated busbars are not shown; only the positional relationship between the prefabricated busbars and the cells is illustrated. The position of the prefabricated busbars is indicated by dashed lines. The photovoltaic module includes multiple cell strings 200 and prefabricated busbars. Each of the multiple cell strings includes multiple cells connected in series along the X-direction. The multiple cell strings are arranged in a group along the Y-direction on the photovoltaic module, and at least two groups of cell strings are arranged in the X-direction.
[0057] The battery cell includes alternating anisotropic first grid lines and second grid lines on the back side. The first grid lines are welded by a first solder strip, and the second grid lines are welded by a second solder strip. In a battery string, adjacent battery cells are welded by the first solder strip or by the second solder strip.
[0058] The prefabricated busbar includes an edge prefabricated busbar set at the edge in the X direction. The edge prefabricated busbar is set on two adjacent battery cells at the edge of the battery string and covers one or two adjacent battery strings in the Y direction.
[0059] It also includes an intermediate prefabricated busbar set between two adjacent battery strings in the X direction. The intermediate prefabricated busbar is set on two adjacent battery cells of the two adjacent battery strings and covers one or two adjacent battery strings in the Y direction.
[0060] It also includes an insulating layer disposed between the busbar and the battery cell. The insulating layer extends along the extension direction of the busbar, and the width of the insulating layer is not less than the width of the busbar, and its width does not exceed the welding point.
[0061] BC cells and their structure are common knowledge in the field. BC cell photovoltaic modules with hidden busbars are existing technology in the field. For related technical features such as the spacing between adjacent cells in the X direction, please refer to existing technology.
[0062] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A prefabricated busbar, comprising a busbar strip and welding strips, wherein the busbar strip is strip-shaped, and multiple parallel welding strips are spaced apart along the extension direction of the busbar strip, characterized in that: The welding strip includes a bent portion, and the busbar is located at the lower end of the bent portion and fixed to the bent portion. The length of the bent portion is not less than the width of the busbar, and the width of the bent portion is not less than the height of the busbar.
2. A preformed busbar according to claim 1, wherein: The length of the bent portion is 2mm to 4mm longer than the width of the busbar.
3. The preformed busbar of claim 1, wherein: The height of the bent portion is between 0.3mm and 0.4mm.
4. The preformed busbar of claim 1, wherein: The welding strip and the busbar are welded and fixed together.
5. A preformed busbar according to any one of claims 1 to 4, characterized in that: The bending section includes a first bending area parallel to the main body of the welding strip and transition areas disposed on both sides of the first bending area, wherein the angle between the transition area and the main body of the welding strip is 110° to 160°.
6. A pre-bent busbar bending device for producing the solder strip according to any one of claims 1 to 5, characterized in that: The prefabricated busbar bending device includes an upper mold and a lower mold. The lower mold includes a lower mold body and a protrusion disposed on the lower mold body. The upper mold includes an upper mold body and a groove disposed on the upper mold body. The shapes of the groove and the protrusion are adapted to each other.
7. The preformed busbar bending device according to claim 6, characterized in that: The length of the protrusion and the groove is not less than the length of the busbar.
8. A preformed busbar bending device according to claim 6 or 7, characterized in that: The protrusion has transition portions on both sides, and the angle between the transition portions and the lower mold body is 110° to 160°.
9. A BC-cell photovoltaic module with concealed busbars, comprising the prefabricated busbar as described in any one of claims 1 to 5, characterized in that: The welding strip of the prefabricated busbar is disposed above the busbar, and the busbar is disposed between two adjacent battery cells. The main body of the welding strip contacts the welding point of the battery cell grid line, and the welding strip and the battery cell grid line are welded and fixed at the welding point.
10. The hidden busbar BC solar module of claim 9, wherein: The photovoltaic module includes multiple battery strings and the prefabricated busbar, wherein each of the multiple battery strings includes multiple battery cells connected in series along the X direction, the multiple battery strings are arranged in the Y direction on the photovoltaic module to form a group of battery strings, and at least two groups of battery strings are arranged in the X direction. The battery cell includes alternating anisotropic first grid lines and second grid lines on the back side. The first grid lines are welded by a first solder strip, and the second grid lines are welded by a second solder strip. In a battery string, adjacent battery cells are welded by the first solder strip or by the second solder strip. The prefabricated busbar includes an edge prefabricated busbar disposed at the edge in the X direction. The edge prefabricated busbar is disposed on two adjacent battery cells at the edge of the battery string and covers one or two adjacent battery strings in the Y direction. The prefabricated busbar also includes an intermediate prefabricated busbar disposed between two adjacent battery strings in the X direction. The intermediate prefabricated busbar is disposed on two adjacent battery cells of the two adjacent battery strings and covers one or two adjacent battery strings in the Y direction. It also includes an insulating layer disposed between the busbar and the battery cell. The insulating layer extends along the extension direction of the busbar, and the width of the insulating layer is not less than the width of the busbar, and its width does not exceed the welding point.