A foldable bus bar, circuit connection structure and shingled assembly

Abstract

The present invention provides a foldable busbar, including a main body, with a plurality of connection blocks on one side of the main body, the connection blocks are welded to the pad points on the front side of the battery cell near the output end and folded together with the main body along the edge of the battery cell near the output end toward the back side of the battery cell. A circuit connection structure for connecting battery cells using the foldable busbar and a shingled assembly electrically connected using the circuit connection structure are also proposed. The foldable busbar designed in the present invention not only improves the connection method of the shingled assembly circuit, but also improves the utilization rate of the battery cell area and improves the overall output power of the shingled assembly; while keeping the creepage distance and the shingled assembly unchanged, the busbar of this structure can increase the overall length of the battery string by about 4-10 mm and the effective light receiving area by 0.2-0.5%. This method can increase the assembly power by about 1-2.5W on a standard shingled assembly.

Description

Technical Field

[0001] The invention belongs to the technical field of stacking solar shingled components, and in particular relates to a foldable bus bar, a circuit connection structure and a shingled component. Background Art

[0002] The negative terminal circuit design in the existing shingled modules mainly welds the bus bar to the back electrode of the cell and then makes a bus connection. However, this design will cause the last cell to only serve as a carrier for connecting the circuit, but not to generate electricity. For power generation bases with large-scale batch placement of shingled module modules, if the circuit design structure of this shingled module cannot be improved, the last cell in each shingled module module will not be able to generate electricity, resulting in many cells in multiple groups of shingled module modules being unable to be used for power generation, which will lead to serious waste of cells as a whole and difficulty in increasing the overall output power. With the development of the photovoltaic market, the application of large-size cells has gradually increased, and the current of a single cell has increased. If the existing circuit design is still used, the utilization rate of the cell area is low, resulting in difficulty in output power gain and increased production costs.

[0003] China's public patent CN209282222U - A circuit connection structure for a shingled assembly proposes a special-shaped busbar that is electrically connected to the last cell at the negative end of the shingled assembly, thereby drawing out current for filtering and power generation. However, the busbar of this structure will occupy more creepage distance, that is, the distance from the last cell to the edge of the assembly increases, resulting in an increase in the occupied area of ​​the shingled assembly, which will reduce the power generation efficiency of the assembly under the same power. The solder joints formed by the stepped protrusions and through holes in the busbar structure proposed in this patent are too small, and the busbar cannot be folded to reduce the creepage distance occupied by the busbar. Summary of the invention

[0004] The present invention provides a foldable bus bar, a circuit connection structure and a shingled assembly, which are particularly suitable for the electrical connection of large-size battery cells, and solves the technical problem in the prior art that the unreasonable design of the bus bar structure causes the circuit connection structure at the negative end of the shingled assembly to occupy a large creepage distance, resulting in a reduction in the effective light-receiving area of ​​the shingled assembly and difficulty in overall output power gain.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A foldable busbar includes a body, and a plurality of connection blocks are provided on one side of the body. The connection blocks are welded to the pad points on the front side of the battery cell near the output end and folded together with the body along the edge of the battery cell near the output end toward the back side of the battery cell. The creepage distance occupied by the busbar can be reduced, and the length of the battery string can be increased while keeping the creepage distance unchanged, thereby increasing the light receiving area of ​​the battery string and improving the effective power of the component.

[0007] Furthermore, the connection block includes a welding section integrally connected and an extension section disposed at both ends of the welding section, wherein the welding section is disposed away from the main body and is welded to the pad point on the front side of the cell near the output end; the extension section is disposed near one side of the main body, and a portion of the section surface of the extension section near the side of the main body is folded along the width direction of the extension section together with the main body on the back side of the cell; the plane structure of the welding section at least covers the pad point. By folding the bus bar, the circuit connection method of the shingled assembly is further improved. Under the condition that the last cell at the negative end generates electricity, the folded side of the bus bar is hidden on the back side of the cell, and the bus bar body structure, terminal welding scar, etc. cannot be seen on the front side of the cell. The welding position of the pad point in the cell is completely covered to prevent the incomplete welding point from being exposed, ensure the welding quality, and is also suitable for cells of various sizes.

[0008] Preferably, the length and width of the welding section are greater than the maximum length and width of the pad point, and the side edge of the welding section close to the extension section is flush with the outer side edge of the pad point, thereby ensuring the welding quality and reducing the degree of hidden cracks in the assembly welding.

[0009] Preferably, the extension sections are arranged in parallel and symmetrically on both sides of the length direction of the welding section; the extension sections are arranged perpendicular to the welding sections; the welding sections are arranged in parallel with the main body. The symmetrical structure of the extension sections is not only convenient for processing but also more conducive to improving the quality of busbar welding and ensuring the welding effect; at the same time, the distance between the extension sections is an empty through hole. This setting can avoid blocking the battery cells during welding after folding, avoid affecting the power generation of the battery cells, and at the same time, the symmetrically arranged structure can improve the stability of the busbar connection. The vertically arranged structure is more convenient for folding operation; the welding sections are arranged parallel to the length direction of the main body and the outer edge of the battery cell, which can further ensure the accuracy of the welding position of the main body; the overall structure is simple, not only convenient for folding, but also conducive to processing.

[0010] Furthermore, a transition section is provided between the welding section and the extension section, and the transition section connects the welding section and the extension section respectively, which is not only conducive to adjusting the welding section and the pad point for welding, but also conducive to the processing of the overall connection block.

[0011] Furthermore, the length of the extended section folded on the back of the cell is greater than the length of the extended section placed on the front of the cell. The purpose is to ensure that the busbar is completely on the back of the cell after folding, avoiding uneven force due to partial failure to press on the cell, and also avoiding the cell from breaking.

[0012] Preferably, the width and thickness of the welding section are the same as the width and thickness of the extension section; the length of the welding section is not greater than the inner distance between adjacent extension sections and is less than the length of the extension section; the thickness of the welding section is the same as the thickness of the main body; the width of the main body is increased by 4-10mm. The overall busbar thickness is uniform and consistent, while ensuring that the busbar is connected to the front of the battery cell, the creepage distance occupied by the busbar is minimized to increase the length of the battery string and the light-receiving area of ​​the battery string. Under the condition of ensuring that the thickness of the main body is the same as that of the extension section and the welding section, the width of the main body is increased, thereby increasing the cross-sectional area of ​​the busbar, reducing the heat generated at the busbar during outdoor power generation, and extending the service life.

[0013] A circuit connection structure uses the bus bar as described above to perform circuit connection on battery cells.

[0014] Furthermore, the welding section is welded to the pad point on the front side of the battery cell close to the output end; the main body and the extension section are folded together to the back side of the battery cell and connected to the insulating strip provided on the back side of the battery cell to form a circuit channel.

[0015] A shingled module, wherein the last cell sheet on the negative terminal side of the module is electrically connected by the circuit connection structure as described above.

[0016] 1. The foldable busbar proposed in the present invention is especially for the electrical connection of large-size battery cells. The busbar is seamlessly electrically connected to the front of the battery cell by matching the welding section with the pad point on the front of the last battery cell at the negative end of the shingled module. The connecting surface between the welding section and the extension section is folded along the width direction of the extension section so that the extension section and the main body are folded along the edge of the battery cell. Under the condition of keeping the creepage distance of the module unchanged, the length of the battery string can be increased by about 4-10 mm, thereby increasing the light-receiving area of ​​the battery string.

[0017] Compared with the size of conventional busbars, the thickness of the busbar of the present application remains unchanged, and the width of the main body is increased. At the same time, it is proposed to flip the extension section along the width direction perpendicular to the main body together with the main body, which can not only reduce the degree of hidden cracks in the component welding, but also reduce the heat at the busbar during outdoor power generation.

[0018] 2. The circuit connection structure proposed in the present invention further improves the circuit connection method of the shingled module by folding the bus bar. Under the condition of ensuring that the last battery cell at the negative end generates electricity, the folded side of the bus bar is hidden on the back of the battery cell. This can reduce the area occupied by the bus bar in the area where the creepage distance is located, thereby increasing the length of the battery string to increase the light-receiving area of ​​the shingled module, thereby increasing the effective power of the module.

[0019] 3. The shingled assembly proposed in the present invention is a assembly in which the welding section in the busbar connection block is welded to the pad point on the front side of the last cell on the negative end of the assembly, and the transition section connecting the welding section and the extension section is placed together with part of the extension section and the welding section on the front side of the cell. The remaining extension section and the main body are folded together on the back side of the cell and isolated with an insulating strip to prevent short circuits. At the same time, the busbar main body structure, terminal welding scars, etc. cannot be seen on the front side of the cell. The shingled assembly welded in this electrical connection method formed by the foldable busbar can increase the overall length of the battery string by about 4-10mm while keeping the creepage distance and assembly area unchanged. The increased battery string length can increase the effective light-receiving area of ​​the shingled assembly by 0.2-0.5%. According to the increased battery string length in this circuit connection method, the assembly power can be increased by about 1-2.5W on a standard version of the shingled assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a foldable bus bar according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic structural diagram of the bus bar and the front side of the battery cell being welded in one embodiment of the present invention;

[0022] Figure 3 is an enlarged view of part A of one embodiment of the present invention;

[0023] Figure 4 This is a schematic structural diagram of the bus bar and the back side of the battery cell being welded in one embodiment of the present invention;

[0024] Figure 5 It is a schematic structural diagram of a transition section of another embodiment of the present invention.

[0025] In the figure:

[0026] 100, bus bar 110, body 120, connection block

[0027] 121, welding section 122, transition section 123, extension section

[0028] 200, battery cell 210, front 220, pad point

[0029] 230, back 300, insulation strip DETAILED DESCRIPTION

[0030] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] This embodiment provides a foldable bus bar 100 for a shingled assembly. Figure 1 As shown, the main body 110 includes a rectangular structure, and a plurality of connecting blocks 120 are arranged side by side on one side of the main body 110. In the process of manufacturing the shingled assembly, the welding matching structure diagram of the bus bar 100 and the battery cell 200 is as shown in FIG. Figure 2 As shown, the connection block 120 is welded to the pad point 220 on the side of the front side 210 of the battery cell 200 close to the output end and is folded together with the body 110 along the edge of the side of the battery cell 200 close to the output end toward the back side 230 of the battery cell 200. The foldable bus bar 100 in this embodiment can not only reduce the creepage distance occupied by the bus bar 100 on the negative electrode side of the shingled assembly, but also increase the length of the battery string and increase the light receiving area of ​​the battery string while keeping the creepage distance unchanged, thereby increasing the effective power of the shingled assembly.

[0032] Specifically, as shown in Figure 2, each connection block 120 includes a welding section 121 integrally connected and an extension section 123 disposed at both ends of the welding section 121. The welding section 121 is disposed away from the body 110 and is welded to the pad point 220 on the front side 210 of the battery cell 200 close to the output end. The extension section 123 is disposed close to one side of the body 110. The portion of the section surface of the extension section 123 close to the side of the body 110 is folded along the width direction of the extension section 123 together with the body 110 to the back side 230 of the battery cell 200, and is welded to the insulating strip 300 disposed on the back side 230. The insulating strip 300 is used to isolate the bus bar 100 and the battery cell 200 to prevent short circuits. The structure of the bus bar 100 and the back side 230 of the battery cell 200 being welded together is shown in Figure 2. Figure 4 By folding and welding the busbar 100 for current collection, the circuit connection mode of the shingled assembly can be further improved. Under the condition that the last battery cell 200 at the negative terminal generates electricity, the folded side of the busbar 100 is hidden on the back side 230 of the battery cell 200, so that the main body 110 structure of the busbar 100 and the terminal welding scar cannot be seen on the front side of the battery cell 200.

[0033] Preferably, a transition section 122 arranged in an inclined manner or in an arc shape is further provided between the welding section 121 and the extension section 123. The transition section 122 arranged in an inclined manner is as follows: Figure 3 As shown, the transition section 122 of the arc structure is as shown in Figure 5As shown, the transition section 122 is connected to the welding section 121 and the extension section 123 respectively. This structure is not only conducive to adjusting the position of the welding section 121 and the pad point 220 for alignment welding, but also conducive to the processing of the overall connection block 120.

[0034] Furthermore, the planar structure of the welding segment 121 at least covers the area where the pad point 220 is located, that is, each welding segment 121 completely covers the welding position of the corresponding pad point 220 in the front side 210 of the battery cell 200, preventing the welding point from being incomplete and exposed, ensuring the welding quality, and is also suitable for the structure of the pad point 220 of battery cells 200 of various sizes and specifications.

[0035] Preferably, the welding section 121 is arranged in parallel with the length direction of the pad point 220, that is, the welding section 121 is arranged in parallel with the length direction of the main body 110, the length and width of the welding section 121 are both greater than the maximum length and maximum width of the pad point 220, and the side edge of the welding section 121 close to the extension section 123 is arranged flush with the outer side edge of the pad point 220, so as to ensure the welding quality and reduce the degree of hidden cracks in the welding of the shingled assembly.

[0036] Furthermore, the extension sections 123 are arranged in parallel and symmetrically on both sides of the length direction of the welding section 121, that is, the symmetrical structure of the extension sections 123 is not only convenient for processing but also more conducive to improving the welding quality of the busbar 100 and ensuring the welding effect; at the same time, the distance between the extension sections 123 is an empty through hole, and the through hole passes through the thickness of the connecting block 120. The through hole structure is the same as the shape structure formed by the extension sections 123, the main body 110 and the welding section 121. This structural setting can prevent the busbar 100 from blocking the front side 210 of the battery cell 200 during welding after being folded, thereby avoiding affecting the power generation of the battery cell 200. At the same time, the symmetrically arranged structure can improve the stability of the connection of the busbar 100.

[0037] Preferably, the extension section 123 is arranged perpendicular to the welding section 121. Since the welding section 121 is arranged in parallel with the body 110, the extension section 123 is also arranged perpendicular to the length direction of the body 110, and the connecting block 120 composed of the welding section 121, the transition section 122 and the extension section 123 is processed in the same plane as the body 110. The vertically arranged extension section 123 structure is more convenient for folding operation; the welding section 121 is arranged parallel to the length direction of the body 110 and the outer edge of the battery cell 200, which can further ensure the accuracy of the welding position of the body 110; the overall structure of the foldable busbar 100 is simple, which is not only convenient for folding, but also conducive to processing.

[0038] Further, such as Figure 3As shown, the length D1 of the extension section 123 folded on the back side 230 of the battery cell 200 is greater than the length D2 of the extension section 123 placed on the front side 210 of the battery cell 200. Preferably, the length D1 of the extension section 123 placed on the back side 230 is greater than the sum of the length D2 of the extension section 123 placed on the front side 210 and the vertical distance D3 of the transition section 122 perpendicular to the welding section 121. The purpose of this arrangement is to enable the bus bar 100 to be completely on the back side 230 of the battery cell 200 after being folded, so as to avoid uneven force on the bus bar 100 due to the extension section 123 not being partially pressed on the battery cell 200, and to avoid the battery cell 200 from being broken. The structure of the bus bar 100 and the back side 230 of the battery cell 200 are welded and matched as shown in FIG. Figure 4 shown.

[0039] Furthermore, the width and thickness of the welding section 121 are the same as the width and thickness of the extension section 123, and the thickness of the welding section 121 is the same as the thickness of the body 110. The length of the welding section 121 is not greater than the inner distance between adjacent extension sections 123 and is less than the length of the extension section 123. Preferably, the length of the welding section 121 is the same as the length of the pad point 220 and the same as the width between adjacent extension sections 123, and the length of the extension section 123 is greater than the length of the welding section 121. This is because this structure can make the overall thickness of the busbar 100 uniform and consistent, while ensuring that the busbar 100 is connected to the front side 210 of the battery cell 200, the creepage distance occupied by the busbar 100 is minimized to increase the length of the battery string, thereby increasing the light receiving area of ​​the battery string.

[0040] In this embodiment, since the size of the battery cell 200 is larger than the conventional size, the current flowing therethrough increases. Under the condition that the thickness of the welding section 121 is the same as the thickness of the body 110, the cross-sectional area of ​​the busbar 100 body 110 needs to be increased, thereby adjusting the width of the body 110. Preferably, the width of the body 110 is increased by 4-10 mm. This setting increases the width of the body 110 while ensuring that the thickness of the body 110 is the same as that of the welding section 121, the transition section 122, and the extension section 123, thereby increasing the cross-sectional area of ​​the busbar 100, reducing the heat generated at the busbar 100 during outdoor power generation, and extending the service life.

[0041] The foldable busbar 100 proposed in the present invention is especially for the electrical connection of large-size battery cells 200. The welding section 121 is adapted to the pad point 220 in the front side 210 of the last battery cell 200 at the negative end of the shingled module and welded to make the busbar 100 and the front side of the battery cell 200 seamlessly electrically connected. Then, the connecting surface between the welding section 121 and the extension section 123 is folded along the width direction of the extension section 123, so that part of the extension section 123 is folded along the edge of the battery cell 200 together with the main body 110. Under the condition of keeping the creepage distance of the module unchanged, the length of the battery string can be increased by about 4-10 mm, thereby increasing the light receiving area of ​​the battery string.

[0042] A circuit connection structure, such as Figure 2 As shown, the bus bar 100 as described above is used to connect the battery cells 200 in a circuit, and the specific steps are as follows:

[0043] First, the welding section 121 in the connection block 120 is welded to the pad point 220 on the front side 210 of the last battery cell 200 of the negative electrode of the shingled assembly close to the output end, ensuring that the pad point 220 is completely covered by the welding section 121 .

[0044] Secondly, an insulating strip 300 is provided on the back side 230 of the battery cell 200 close to the pad point and along the length direction of the bus bar 100 body 110, and a portion of the insulating strip 300 in the width direction is connected to the back side 230 of the battery cell 200, and the other portion is extended outward. The width of the insulating strip 300 is greater than the width of the bus bar 100 on the side of the back side 230 of the battery cell 200, and the length of the insulating strip 300 is not less than the length of the bus bar 100.

[0045] Next, the busbar 100 is folded along the width direction of the extension section 123, that is, part of the length of the extension section 123 is placed on the front side 210 of the battery cell 200 together with the transition section 122 and the welding section 121, and another part of the length of the extension section 123 is folded together with the body 110 and welded to the insulating strip 300 placed on the back side 230 of the battery cell 200, and the length D1 of the extension section 123 folded on the back side 230 of the battery cell 200 is greater than the length D2 of the extension section 123 placed on the front side 210 of the battery cell 200. Preferably, the length D1 of the extension section 123 placed on the back side 230 is greater than the sum of the length D2 of the extension section 123 placed on the front side 210 and the vertical distance D3 of the transition section 122 perpendicular to the welding section 121. Furthermore, the body 110 and part of the section surface of the extension section 123 are folded together to the back side 230 of the battery cell 200 and connected to the insulating strip configured on the back side 230 of the battery cell 200 to form a circuit channel.

[0046] By folding the bus bar 100, not only the circuit connection method of the shingled module is further improved, but also the folded side of the bus bar 100 is hidden on the back of the battery cell 200 while ensuring the power generation of the last battery cell 200 at the negative end. This can reduce the area occupied by the bus bar 100 in the area where the creepage distance is located, thereby increasing the length of the battery string by about 4-10mm as a whole, thereby increasing the light-receiving area of ​​the shingled module and thus increasing the effective power of the module.

[0047] In this embodiment, the electrical connection method formed by the foldable busbar 100 can increase the overall length of the battery string by about 4-10 mm, and the increase in the length of the battery string can increase the effective light receiving area of ​​the shingled module by 0.2-0.5%. According to this circuit connection method, the length of the battery string increased, on a standard version of the shingled module, the module power can be increased by about 1-2.5W.

[0048] A shingled module, wherein the last cell sheet on the negative terminal side of the module is electrically connected by the circuit connection structure as described above.

[0049] 1. The foldable busbar proposed in the present invention is especially for the electrical connection of large-size battery cells. The busbar is seamlessly electrically connected to the front of the battery cell by matching the welding section with the pad point on the front of the last battery cell at the negative end of the shingled module. The connecting surface between the welding section and the extension section is folded along the width direction of the extension section so that the extension section and the main body are folded along the edge of the battery cell. Under the condition of keeping the creepage distance of the module unchanged, the length of the battery string can be increased by about 4-10 mm, thereby increasing the light-receiving area of ​​the battery string.

[0050] Compared with the size of conventional busbars, the thickness of the busbar of the present application remains unchanged, and the width of the main body is increased. At the same time, it is proposed to flip the extension section along the width direction perpendicular to the main body together with the main body, which can not only reduce the degree of hidden cracks in the component welding, but also reduce the heat at the busbar during outdoor power generation.

[0051] 2. The circuit connection structure proposed in the present invention further improves the circuit connection method of the shingled module by folding the bus bar. Under the condition of ensuring that the last battery cell at the negative end generates electricity, the folded side of the bus bar is hidden on the back of the battery cell. This can reduce the area occupied by the bus bar in the area where the creepage distance is located, thereby increasing the length of the battery string to increase the light-receiving area of ​​the shingled module, thereby increasing the effective power of the module.

[0052] 3. The shingled assembly proposed in the present invention is a assembly in which the welding section in the busbar connection block is welded to the pad point on the front side of the last cell on the negative end of the assembly, and the transition section connecting the welding section and the extension section is placed together with part of the extension section and the welding section on the front side of the cell. The remaining extension section and the body are folded together on the back side of the cell and isolated with an insulating strip to prevent short circuits. At the same time, the busbar body structure, terminal welding scars, etc. cannot be seen on the front side of the cell. The shingled assembly welded in the electrical connection method formed by this foldable busbar 100 can increase the overall length of the battery string by about 4-10 mm while keeping the creepage distance and assembly area unchanged. The increased battery string length can increase the effective light-receiving area of ​​the shingled assembly by 0.2-0.5%. According to the increased battery string length in this circuit connection method, the assembly power can be increased by about 1-2.5W on a standard version of the shingled assembly.

[0053] The above embodiments of the present invention are described in detail, and the contents are only preferred embodiments of the present invention, and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A foldable bus bar, comprising a body, characterized in that: A plurality of connection blocks are provided on one side of the body, the connection blocks are welded to the pad points on the front side of the battery cell near the output end and are folded together with the body along the edge of the battery cell near the output end toward the back side of the battery cell; the connection blocks include a welding section integrally connected and an extension section disposed at both ends of the welding section, the welding section is disposed away from the body and welded to the pad points on the front side of the battery cell near the output end; The extension section is arranged close to one side of the main body, and a portion of the section surface of the extension section close to one side of the main body is folded together with the main body along the width direction of the extension section to the back side of the battery cell; The welding section planar structure at least covers the pad point.

2. The foldable bus bar according to claim 1, characterized in that: The length and width of the welding section are both greater than the maximum length and width of the pad point, and the side edge of the welding section close to the extension section is arranged flush with the outer side edge of the pad point.

3. A foldable bus bar according to claim 1 or 2, characterized in that: The extension sections are arranged in parallel and symmetrically on both sides of the length direction of the welding section; The extension section is arranged perpendicular to the welding section; The welding section is arranged in parallel with the main body.

4. The foldable bus bar according to claim 3, characterized in that: A transition section is further provided between the welding section and the extension section, and the transition section connects the welding section and the extension section respectively.

5. A foldable bus bar according to any one of claims 1 to 2 and 4, characterized in that: The length of the extended section folded over the back side of the battery cell is greater than the length of the extended section placed on the front side of the battery cell.

6. The foldable bus bar according to claim 5, characterized in that: The width and thickness of the welding section are the same as the width and thickness of the extension section; The length of the welding section is not greater than the inner distance between adjacent extension sections and is less than the length of the extension section; The thickness of the welding section is the same as the thickness of the body; The body width is increased by 4-10 mm.

7. A circuit connection structure, characterized in that: The bus bar as claimed in any one of claims 1 to 6 is used to connect the battery cells in circuit.

8. A circuit connection structure according to claim 7, characterized in that: Performing alignment welding between the welding section and the pad point on the front side of the battery cell close to the output end; The main body and the extension section are folded together to the back side of the battery cell and connected to an insulating strip disposed on the back side of the battery cell to form a circuit channel.

9. A shingled assembly, characterized in that: The last cell on the negative terminal side of the shingled assembly is electrically connected using the circuit connection structure as described in any one of claims 7 to 8.

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