A battery string welding device and welding apparatus

Abstract

This invention relates to the field of photovoltaic cell string welding. The cell string welding apparatus includes a laser welding device located at a welding station. The laser welding device includes a laser generator, a galvanometer assembly, and a field lens. The laser generator emits a laser beam toward the galvanometer assembly; the galvanometer assembly reflects the laser beam to the field lens; the field lens focuses the laser beam and directs it toward the welding point of the cell string to be repaired at the welding station, thereby welding the two weld strips at the welding point or welding the weld strips at the welding point to the cell. This invention uses a laser welding device to weld the cell string to be repaired. Laser welding has a small heated area, which can avoid over-welding in non-repair areas during repair.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cell string welding, specifically to a cell string welding apparatus and welding equipment. Background Technology

[0002] A battery string is made up of several battery cells welded together with solder strips. Because the battery cells are relatively thin and brittle, defective battery cells may appear in the battery string during the welding or transfer process, requiring the battery string to be repaired.

[0003] For battery cells that can be repaired by patching the poor solder joints, the solder strips at the poorly soldered solder pads need to be re-welded to the battery cell. For battery cells that need to be replaced, the defective battery cell is first removed, and a qualified replacement battery cell is placed in the position of the original defective battery cell. Then, the solder strips on the replacement battery cell are welded to the solder strips on the adjacent battery cells one by one.

[0004] Conventional battery string welding equipment includes infrared lamp boxes, electromagnetic welding equipment, and soldering irons. When welding battery strings, the above-mentioned welding equipment has a large heating area. However, when battery strings are repaired, the welding points are usually at the cold solder joints or the overlap of the solder strips between the replacement cells and adjacent cells. The rest of the battery string does not need to be welded. Using conventional battery string welding equipment can easily cause over-welding problems by re-welding non-repair parts of the battery string, which will ultimately affect the power generation performance of the photovoltaic module. Summary of the Invention

[0005] This invention addresses the problem of over-soldering that conventional welding devices easily cause when repairing battery strings. One aspect of the invention is a battery string welding device, the technical solution of which is as follows:

[0006] A battery string welding apparatus includes a laser welding device disposed at a welding station. The laser welding device includes a laser generator, a galvanometer assembly, and a field lens, wherein: the laser generator emits a laser beam toward the galvanometer assembly; the galvanometer assembly reflects the laser beam to the field lens; the field lens focuses the laser beam and directs it toward the welding point of the battery string to be repaired at the welding station, so as to weld two welding strips at the welding point or weld the welding strip at the welding point to the battery cell.

[0007] This invention uses a laser welding device to weld the battery strings to be repaired. Laser welding has a small heated area and can achieve spot welding. Therefore, when repairing battery strings, each point to be welded can be welded individually, without heating and welding non-repair parts of the battery string, thereby avoiding over-welding of non-repair parts.

[0008] Optionally, the laser beam can be a pulsed laser or a continuous laser, and the beam quality factor of the laser beam is greater than 3.

[0009] Selecting a laser beam with a beam quality factor greater than 3 ensures a relatively uniform intensity distribution within the beam spot, preventing material ablation at the center of the beam spot and further improving welding quality during rework.

[0010] Optionally, the focal point of the laser beam is located above or below the point to be welded, and the major axis of the laser spot formed on the battery string to be repaired is 1mm to 3mm.

[0011] By focusing the laser beam above or below the point to be welded, and defocusing the laser beam, damage to the point to be welded can be avoided due to the high intensity at the focal point, thus improving the quality of rework welding. The long diameter of the laser spot formed on the battery string to be welded is within 1mm to 3mm, which can be flexibly selected according to the operating environment or the size of the point to be welded, increasing the adaptability of laser welding.

[0012] Optionally, the number of scans when welding the point to be welded by the laser beam is one or at least two.

[0013] Depending on the operating environment, the laser beam may be controlled to scan the welding point once or at least twice to achieve better welding results.

[0014] Optionally, during the laser beam scanning of the point to be welded, adjacent laser spots formed on the battery string to be repaired may intersect, be tangent to, or be separated.

[0015] Optionally, the laser welding device also includes a mounting base, on which the laser generator, galvanometer assembly, and field lens are all fixedly mounted; the battery string welding device also includes a transverse module, on which the mounting base is fixedly mounted on the moving end of the transverse module, and the transverse direction of the transverse module is perpendicular to the stringing direction of the battery string to be repaired.

[0016] By mounting the laser generator, galvanometer assembly, and field lens on the transverse module via a mounting base, the laser generator, galvanometer assembly, and field lens can be moved laterally along the stringing direction perpendicular to the battery string to be repaired, thus improving the laser welding device's flexible control over the welding area.

[0017] Optionally, the battery string welding device also includes a camera and a control chip. Both the laser welding device and the camera are connected to the control chip. The camera is fixedly mounted on the mounting base and is used to take pictures of the battery strings to be repaired at the welding station. The control chip determines the position of the welding point based on the image taken by the camera. The laser welding device welds the welding point according to its position.

[0018] By setting up a camera, it is possible to take pictures of the battery strings to be repaired and welded. The control chip determines the position of the welding point based on the captured image, which can improve the welding accuracy during repair. By also fixing the camera on the mounting base, the camera can move synchronously with the laser generator, galvanometer assembly and field lens in the laser welding device. Welding is performed after each picture is taken, which can further improve the positioning accuracy of the welding point.

[0019] Optionally, the battery string welding device also includes a lifting module, with the traversing module fixedly connected to the moving end of the lifting module.

[0020] By fixing the horizontal movement module to the moving end of the lifting module, the height of the laser generator, galvanometer assembly, and field lens can be adjusted, allowing for flexible adjustment of the scanning area of ​​the laser beam.

[0021] Optionally, an adjustable beam expander is provided between the laser generator and the galvanometer assembly to adjust the size of the focused spot of the laser beam on the focal plane.

[0022] By using a divergence-adjustable beam expander to adjust the size of the laser beam spot on the focusing plane, this invention can meet both the calibration accuracy requirements for small spots and the welding accuracy requirements for large spots.

[0023] Optionally, a DOE beam shaper is provided between the divergence angle adjustable beam expander and the galvanometer assembly to shape the beam.

[0024] Optionally, the scanning area of ​​the laser beam along the first direction is wider than the width of the battery cell along the first direction, where the first direction is the stringing direction of the battery string to be repaired and welded.

[0025] The scanning area of ​​the laser beam along the first direction is made wider than the width of the battery cell along the first direction. This allows the laser beam to move only along a direction perpendicular to the first direction during welding, thus enabling the welding of a battery cell to the solder strip on the battery cell and improving welding efficiency.

[0026] On the other hand, a battery string welding device is proposed, and the technical solution is as follows:

[0027] A battery string welding device includes a battery string support platform and the aforementioned battery string welding apparatus. The battery string welding apparatus is disposed on one side of the battery string support platform, and the laser welding apparatus is located above the battery string support platform.

[0028] The battery string welding device of the present invention can be used to repair battery strings on the battery string support platform, thereby further improving the welding quality during battery string repair. Attached Figure Description

[0029] Figure 1This is a three-dimensional structural schematic diagram of an optional embodiment of the battery string welding device of the present invention;

[0030] Figure 2 for Figure 1 A three-dimensional structural diagram of the battery string welding device from another perspective;

[0031] Figure 3 for Figure 1 Front view of the battery string welding device;

[0032] Figure 4A This is a schematic diagram showing the tangency of the laser spot.

[0033] Figure 4B This is a schematic diagram showing the intersection of laser beams;

[0034] Figure 4C This is a schematic diagram of laser spot separation;

[0035] Figure 5 This is a schematic diagram of the laser scanning area and the battery string to be welded;

[0036] Figure 6 This is a schematic diagram of the battery string welding equipment in this invention;

[0037] Figures 1-6 The system includes: a battery string welding device 100; a laser generator 1; a galvanometer assembly 2; a field lens 3; a mounting base 4; a camera 5; a first connecting plate 6; a transverse moving module 7; a moving end 71 of the transverse moving module; a fixed end 72 of the transverse moving module; a lifting module 8; a moving end 81 of the lifting module; a handwheel 9; a second connecting plate 10; a scanning area 11; a battery string support platform 200; battery cells 300; and welding strips 400. Detailed Implementation

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] like Figure 1 and 3The diagram shown illustrates one embodiment of the battery string welding device proposed in this invention. The battery string welding device 100 includes a laser welding device disposed at a welding station. The laser welding device includes a laser generator 1, a galvanometer assembly 2, and a field lens 3. The laser generator 1 emits a laser beam toward the galvanometer assembly 2; the galvanometer assembly 2 reflects the laser beam to the field lens 3; the field lens 3 focuses the laser beam and directs it toward the welding point of the battery string to be repaired at the welding station, thereby welding the two weld strips at the welding point or welding the weld strip at the welding point to the battery cell. Specifically, during repair of a faulty weld, the welding point is a faulty weld point, and the laser beam is directed at the faulty weld point to weld the weld strip at the faulty weld point to the battery cell; during cell replacement repair, the welding point is the overlap point between the weld strip on the replacement battery cell and the weld strip on an adjacent battery cell, and the laser beam is directed at the overlap point to weld the two overlapping weld strips together.

[0040] This invention uses a laser welding device to weld the battery strings to be repaired. Laser welding has a small heated area and can achieve spot welding. Therefore, when repairing battery strings, each point to be welded can be welded individually, without heating and welding non-repair parts of the battery string, thereby avoiding over-welding of non-repair parts.

[0041] To ensure a relatively uniform light intensity distribution within the laser spot, prevent material ablation at the center of the spot, and improve welding quality during rework, a pulsed laser or a continuous laser is selected, with a beam quality factor greater than 3.

[0042] Optionally, the focal point of the laser beam is located above or below the point to be welded, and the major axis of the laser spot formed on the battery string to be repaired is 1mm to 3mm.

[0043] It should be noted that the major axis of the light spot mentioned in this application refers to the maximum value of the line connecting two points on the edge of the light spot under different light spot shapes (circle, rectangle, ellipse, etc.).

[0044] By focusing the laser beam above or below the point to be welded, and defocusing the laser beam, the high-intensity damage to the point to be welded at the focal point can be avoided, thus improving the quality of rework welding. The long diameter of the laser spot formed on the battery string to be reworked is within 1mm to 3mm, which can be flexibly selected according to the operating environment or the size of the point to be welded, increasing the adaptability of laser welding.

[0045] Optionally, the number of scans when welding the point to be welded by the laser beam is one or at least two.

[0046] Before welding, the laser emission power and laser beam scanning speed are manually set according to factors such as the defocus distance and the material of the battery cell. The laser emission power is 1 to 200W. During rework, the laser welding device is moved above the point to be welded, and the laser generator 1 emits a laser beam according to the set laser emission power. The galvanometer assembly controls the laser beam to scan the point to be welded at a certain speed.

[0047] When the energy provided by the laser beam during the laser action time is relatively high compared to the energy required to melt the material in the action area, and the welding requirements of the welding point to be welded can be completed in a single scan, the number of scans is one.

[0048] When the energy provided by the laser beam during the laser action time is relatively low compared to the energy required to melt the material in the action area, and a single scan cannot complete the welding requirements of the welding point, the number of scans should be at least two.

[0049] In both single and multiple scans, the scanning path can be a straight line or a curve. Multiple scans can involve back-and-forth scanning or multiple unidirectional scans.

[0050] Depending on the operating environment, the laser beam may be controlled to scan the welding point once or at least twice to achieve better welding results.

[0051] like Figures 4A-4C As shown, during the laser beam scanning process of the point to be welded, there are various states between adjacent laser spots formed on the battery string to be repaired, all of which can achieve welding of the point to be welded. Figure 4A The diagram shows the tangency between adjacent light spots. Figure 4B The diagram shows the intersection between adjacent light spots. Figure 4C This shows the separation between adjacent light spots.

[0052] like Figure 1 and 2 As shown, the laser welding device also includes a mounting base 4, on which the laser generator 1, galvanometer assembly 2 and field lens 3 are all fixedly mounted; the battery string welding device 100 also includes a transverse module 7, on which the mounting base 4 is fixedly mounted on the moving end 71 of the transverse module, and the transverse direction of the transverse module 7 is perpendicular to the stringing direction of the battery string to be repaired.

[0053] Optionally, the transverse module 7 includes a motor, a synchronous belt, and a first slide block. The first slide block is fixed on the synchronous belt, and the motor drives the synchronous belt to move, thereby realizing the relative movement between the first slide block and the housing of the transverse module 7.

[0054] It is important to note that, for Figure 1 and Figure 2In this embodiment shown, in order to make the mounting base 4 more stable on the transverse module 7, the outer shell with a larger area in the transverse module 7 is used as the moving end 71 of the transverse module, and the first slide in the transverse module 7 is used as the fixed end 72 of the transverse module.

[0055] The laser generator 1, galvanometer assembly 2, and field lens 3 are mounted on the transverse module 7 via the mounting base 4, enabling the laser generator 1, galvanometer assembly 2, and field lens 3 to move laterally along the stringing direction perpendicular to the battery string to be repaired, thus improving the laser welding device's flexible control over the welding area.

[0056] like Figure 2 As shown, the battery string welding device 100 also includes a camera 5 and a control chip. Both the laser welding device and the camera 5 are connected to the control chip. The camera 5 is used to take pictures of the battery string to be repaired at the welding station. The control chip determines the position of the welding point based on the image taken by the camera 5. The laser welding device welds the welding point based on the position of the welding point.

[0057] By setting up camera 5, it is possible to take pictures of the battery strings to be repaired and welded. The control chip determines the position of the welding point based on the captured image, thereby ensuring welding accuracy.

[0058] Optionally, the camera 5 can be fixedly mounted on the mounting base 4 via the first connecting plate 6. Fixing the camera 5 to the mounting base 4 allows it to move synchronously with the laser generator 1, galvanometer assembly 2, and field mirror 3 in the laser welding device. Each time the camera moves, it first takes a picture to obtain the position of each point to be welded within the current laser scanning area. Then, the laser welding device welds the points according to their positions, avoiding positioning errors during movement and further improving the positioning accuracy of the points to be welded.

[0059] Optionally, the battery string welding device 100 also includes a lifting module 8, and a lateral moving module 7 is fixedly connected to the moving end 81 of the lifting module.

[0060] Optionally, the lifting module 8 includes a lead screw, a nut seat, a second slide, and a handwheel 9. The handwheel 9 is fixedly connected to the lead screw, the nut seat is threadedly engaged with the lead screw, and the second slide is fixedly connected to the nut seat. The first slide is fixedly connected to the second slide through a second connecting plate 10.

[0061] By fixing the horizontal movement module 7 to the moving end 81 of the lifting module, the height of the laser generator 1, the galvanometer assembly 2 and the field mirror 3 can be adjusted, and the scanning area 11 of the laser beam can be flexibly adjusted.

[0062] Optionally, an adjustable beam expander is provided between the laser generator 1 and the galvanometer assembly 2 to adjust the size of the focused spot of the laser beam on the focal plane.

[0063] By using a divergence-adjustable beam expander to adjust the size of the laser beam spot on the focusing plane, this invention can meet both the calibration accuracy requirements for small spots and the welding accuracy requirements for large spots.

[0064] Optionally, a DOE beam shaper is provided between the divergence angle adjustable beam expander and the galvanometer assembly 2 to shape the beam.

[0065] Optional, such as Figure 5 As shown, the width W of the scanning area 11 of the laser beam along the first direction is greater than the width w of the battery cell 300 along the first direction, and the first direction is the stringing direction of the battery string to be repaired and welded.

[0066] Please continue to refer to this. Figure 5 The X-axis direction represents the lateral movement direction of the lateral movement module 7, and the Y-axis direction represents the connection direction of the battery string to be repaired, i.e., the first direction. When using the battery string welding device 100 of this application to repair the battery cells 300 and the welding strips 400 on the battery string, the scanning area 11 of the laser beam first covers the right side of the battery cell 300, and the laser beam sequentially repairs and welds each point to be welded within the scanning area 11; then, driven by the lateral movement module 7, the scanning area of ​​the laser beam is moved laterally along the X-axis direction, so that the second scanning area covers the left side of the battery cell 300, and the laser beam sequentially repairs and welds each point to be welded within the second scanning area 11.

[0067] It should be noted that during actual rework, the rework welding of a single battery cell can be completed in one go using a larger scanning area 11, or multiple transverse scanning welding can be performed using a smaller scanning area 11. During multiple transverse scanning welding, adjacent scanning areas can be connected or partially overlapped.

[0068] The width of the scanning area 11 of the laser beam along the first direction is greater than the width of the battery cell along the first direction, so that during welding, the laser beam only needs to move along a direction perpendicular to the first direction to achieve the rework welding of a battery cell, thereby improving welding efficiency.

[0069] The laser welding apparatus of the present invention can spot weld solar cells to welding strips, and is therefore also applicable to solar cell welding production with local welding requirements, such as multi-busbar solar cell welding and IBC solar cell welding, thereby improving welding quality.

[0070] like Figure 6As shown, this application also proposes a battery string welding device, including a battery string support platform 200 and a battery string welding device 100 of any of the above-mentioned types. The battery string welding device 100 is disposed on one side of the battery string support platform 200, and the laser welding device is located above the battery string support platform 200.

[0071] Using the battery string welding device 100 of the present invention to rework the battery strings on the battery string support platform 200 can further improve the welding quality during battery string rework.

[0072] The present invention has been described above in sufficient detail and with certain specificities. Those skilled in the art should understand that the descriptions in the embodiments are merely exemplary, and all changes made without departing from the true spirit and scope of the invention should fall within the protection scope of the invention. The scope of protection claimed by the present invention is defined by the claims, and not by the above descriptions in the embodiments.

Claims

1. A battery string welding device, characterized in that, The battery string welding device includes a laser welding device located at the welding station. The laser welding device includes a laser generator, a galvanometer assembly, and a field lens, wherein: The laser generator emits a laser beam toward the galvanometer assembly; The galvanometer assembly reflects the laser beam to the field mirror; The field lens focuses the laser beam and directs it toward the welding point of the battery string to be repaired at the welding station, so as to weld the two welding strips at the welding point or weld the welding strips at the welding point to the battery cell. The focal point of the laser beam is located above or below the point to be welded, and the major axis of the laser spot formed by the laser beam on the battery string to be repaired is 1mm to 3mm. An adjustable beam expander is provided between the laser generator and the galvanometer assembly to adjust the size of the focused spot of the laser beam on the focal plane. A DOE beam shaper is provided between the adjustable divergence angle beam expander and the galvanometer assembly to shape the beam.

2. The battery string welding device according to claim 1, characterized in that, The laser beam is a pulsed laser or a continuous laser, and the beam quality factor of the laser beam is greater than 3.

3. The battery string welding device according to claim 1, characterized in that, The laser beam scans the point to be welded once or at least twice.

4. The battery string welding apparatus according to claim 3, characterized in that, During the process of the laser beam scanning the point to be welded, adjacent light spots formed on the battery string to be repaired intersect, are tangent to, or separate.

5. The battery string welding apparatus according to claim 1, characterized in that, The laser welding device also includes a mounting base, on which the laser generator, the galvanometer assembly, and the field lens are all fixedly mounted. The battery string welding device further includes a transverse module, and the mounting base is fixedly installed on the moving end of the transverse module. The transverse direction of the transverse module is perpendicular to the stringing direction of the battery string to be repaired.

6. The battery string welding apparatus according to claim 5, characterized in that, The battery string welding device also includes a camera and a control chip. Both the laser welding device and the camera are connected to the control chip. The camera is fixedly mounted on the mounting base and is used to take pictures of the battery strings to be repaired at the welding station. The control chip determines the location of the point to be welded based on the image captured by the camera. The laser welding device welds the point to be welded according to its position.

7. The battery string welding apparatus according to claim 5, characterized in that, The battery string welding device also includes a lifting module, and the lateral movement module is fixedly connected to the moving end of the lifting module.

8. The battery string welding apparatus according to claim 1 or 5, characterized in that, The scanning area of ​​the laser beam along the first direction is wider than the width of the battery cell along the first direction, where the first direction is the stringing direction of the battery string to be repaired.

9. A battery string welding device, characterized in that, The battery string welding equipment includes a battery string support platform and a battery string welding device as described in any one of claims 1 to 8, wherein the battery string welding device is disposed on one side of the battery string support platform and the laser welding device is located above the battery string support platform.

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