A solar cell module and a photovoltaic system

Abstract

The present application relates to the technical field of solar cells, and discloses a solar cell module and a photovoltaic system. The solar cell module comprises a cell string, a bus bar and a solder strip. The cell string comprises a plurality of cell pieces connected in series, and the plurality of cell pieces comprise a first cell piece and a second cell piece arranged in sequence with a reference line as a starting point. The bus bar is arranged on the back light surface of the second cell piece and located at one end close to the first cell piece. The orthographic projection of the bus bar covers one end of the first cell piece close to the second cell piece. The length W of the bus bar in the first direction and the length L1 of the bus bar from the center line of the first cell piece and the second cell piece to the edge of the bus bar satisfy 0.2≤L1 / W≤0.8. The solder strip is arranged on the back light surface of the first cell piece and used for electrically connecting the first cell piece and the bus bar. The shielding area of the bus bar is distributed on the first cell piece and the second cell piece, which reduces the area of the single cell piece shielded by the bus bar, improves the double-sided rate and reduces the power loss.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more particularly to a solar cell module and photovoltaic system. Background Technology

[0002] Back-contact battery modules typically consist of several battery strings connected in series and / or in parallel. End busbars are provided in the end region of the battery module, and intermediate busbars are provided in the middle region of the battery module to collect current.

[0003] In related technologies, the busbars are arranged on the back of the cells in the battery string, and the orthographic projection of the busbars only falls on a single cell. That is, the orthographic projection of the busbars has no overlapping area with adjacent cells, resulting in a large shading area on a single cell. This increases the current loss between two adjacent cells or two battery strings during the power test of the back of the battery module, thereby increasing the power loss on the back of the battery module. This leads to a significant reduction in the bifaciality of the battery module and affects the overall power of the battery module.

[0004] Therefore, there is an urgent need for a solar cell module and photovoltaic system to solve the above problems. Summary of the Invention

[0005] Based on the above problems, the purpose of this invention is to provide a solar cell module and photovoltaic system that can solve the problems of low bifaciality and large power loss of the battery module caused by the large area of ​​a single cell being blocked by the busbar.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] On the one hand, a solar cell module is provided, comprising:

[0008] A battery string includes a plurality of battery cells arranged sequentially and connected in series along a first direction. The solar cell module has a reference line, and the plurality of battery cells include a first battery cell and a second battery cell arranged sequentially with the reference line as the starting point.

[0009] A busbar is disposed on the backlight surface of the second battery cell and located at one end close to the first battery cell. The orthographic projection of the busbar covers the end of the first battery cell close to the second battery cell. The busbar extends along a second direction, which intersects the first direction.

[0010] The length of the busbar in the first direction is W, 0.2≤L1 / W≤0.8; where L1 is the length of the busbar in the first direction from the centerline between the first battery cell and the second battery cell to the edge of the busbar.

[0011] A solder strip is disposed on the back surface of the first battery cell and is used to electrically connect the first battery cell and the busbar.

[0012] As an optional embodiment of the solar cell module of the present invention, the reference line is located at the end of the solar cell module;

[0013] Alternatively, the baseline may be located in the middle of the solar cell module.

[0014] As an optional embodiment of the solar cell module of the present invention, when the reference line is located at the end of the solar cell module, the solder strip includes a first solder strip, the first solder strip includes a first main body segment and a first connecting segment connected together, the first main body segment is electrically connected to the first solar cell, and the first connecting segment overlaps with and is electrically connected to the busbar in the first direction.

[0015] As an optional embodiment of the solar cell module of the present invention, when the reference line is located in the middle of the solar cell module, the solder strip includes a second solder strip, the solar cell module includes a parallel battery string group, the parallel battery string group includes at least two battery strings disposed on both sides of the reference line and connected in parallel, the first cells of the two battery strings on both sides of the reference line are arranged adjacent to each other, and the second solder strip is used to electrically connect the bus bar and the two first cells on both sides of the reference line;

[0016] The second welding strip includes a second main body segment and a second connecting segment connected together. The second main body segment is electrically connected to the first battery cell, and the second connecting segment overlaps with and is electrically connected to the busbar in the first direction.

[0017] As an optional embodiment of the solar cell module of the present invention, the solder strip extends at least partially above the busbar to overlap with and be electrically connected to the busbar in the first direction;

[0018] Alternatively, the solder strip may extend at least partially below the busbar to overlap with and be electrically connected to the busbar in the first direction.

[0019] As an optional embodiment of the solar cell module of the present invention, the overlap length between the solder strip and the busbar in the first direction is D1, and L1 / 4 ≤ D1 < L1.

[0020] As an optional embodiment of the solar cell module of the present invention, the solder strip includes a third main body segment, a bent segment and a third connecting segment. The third main body segment is electrically connected to the first solar cell. The third connecting segment is bent and connected to the third main body segment through the bent segment. The third connecting segment and the third main body segment are staggered in the second direction. The third connecting segment overlaps with and is electrically connected to the busbar in the first direction.

[0021] As an optional embodiment of the solar cell module of the present invention, the area of ​​the busbar's orthogonal projection covering the first solar cell is equal to the area covering the second solar cell.

[0022] As an optional embodiment of the solar cell module of the present invention, the first solar cell and the second solar cell are arranged adjacent to each other and maintain a preset distance;

[0023] Alternatively, the first and second battery cells may at least partially overlap in the first direction to form an overlapping region, and the orthographic projection of the busbar covers the overlapping region.

[0024] As an optional embodiment of the solar cell module of the present invention, when the first cell and the second cell at least partially overlap in the first direction, the center line is the center line of the overlapping area of ​​the first cell and the second cell;

[0025] When the first battery cell and the second battery cell are spaced apart, the center line is the center line of the spaced area between the first battery cell and the second battery cell.

[0026] As an optional embodiment of the solar cell module of the present invention, the solar cell module further includes an insulating strip disposed on the back surface of the second cell and located between the busbar and the second cell. The orthographic projection of the insulating strip covers the end of the first cell near the second cell, and the orthographic projection of the busbar is located within the orthographic projection of the insulating strip.

[0027] As an optional embodiment of the solar cell module of the present invention, the cell string further includes series solder strips, wherein in the first direction, each pair of adjacent cells is connected by the series solder strips.

[0028] As an optional embodiment of the solar cell module of the present invention, the solar cell is rectangular, and the two sides of the solar cell in the first direction are respectively a first side and a second side, and the solar cell is provided with chamfers at both ends of the first side and / or both ends of the second side.

[0029] The first sides of two adjacent battery cells are arranged adjacent to each other; or, the first sides and second sides of two adjacent battery cells are arranged adjacent to each other.

[0030] As an optional embodiment of the solar cell module of the present invention, the dimension of the cell in the first direction is X, and the value of X is in the range of 88mm≤X≤110mm;

[0031] And / or, the dimension of the battery cell in the second direction is Y, and the value of Y is in the range of: 166mm≤Y≤220mm.

[0032] As an optional embodiment of the solar cell module of the present invention, the solar cell module includes at least one series-connected battery string group, the series-connected battery string group including two battery strings arranged in series along the second direction.

[0033] On the other hand, a photovoltaic system is provided, including the solar cell module as described above.

[0034] The beneficial effects of this invention are as follows:

[0035] The solar cell module and photovoltaic system provided by this invention have a busbar arranged on the back surface of the second cell and covering the end of the first cell closest to the second cell. In a first direction, the length L1 of the busbar from the centerline between the first and second cells to the edge of the busbar satisfies 0.2 ≤ L1 / W ≤ 0.8 with respect to the total length W of the busbar. That is, in the first direction, the orthographic projection of the busbar covers both the first and second cells, allowing the shading area of ​​the busbar to be distributed across both cells, thereby reducing the area of ​​a single cell shaded by the busbar. Compared to existing solutions where the busbar is only arranged on a single cell, this increases the bifaciality of the solar cell module, thereby improving the overall power of the solar cell module and ensuring the energy conversion efficiency of the photovoltaic system. Furthermore, placing the busbar on the back surface of the first and second cells allows for its concealment, maximizing the light-receiving surface of the cells while maintaining the aesthetics of the solar cell module. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0037] Figure 1 This is a first structural schematic diagram of a solar cell module provided in a specific embodiment of the present invention;

[0038] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0039] Figure 3 yes Figure 2 A magnified view of a section at point C;

[0040] Figure 4yes Figure 3 A partial cross-sectional view;

[0041] Figure 5 yes Figure 1 A magnified view of a section at point B in the middle;

[0042] Figure 6 yes Figure 5 A magnified view of a section at point E in the middle;

[0043] Figure 7 yes Figure 6 A partial cross-sectional view;

[0044] Figure 8 This is a schematic diagram of the second structure of a solar cell module provided in a specific embodiment of the present invention;

[0045] Figure 9 yes Figure 8 A magnified view of a section at point F in the middle;

[0046] Figure 10 yes Figure 9 A partial cross-sectional view;

[0047] Figure 11 yes Figure 8 A magnified view of a section at point G in the middle;

[0048] Figure 12 yes Figure 11 A partial cross-sectional view;

[0049] Figure 13 This is a schematic diagram of the third structure of a solar cell module provided in a specific embodiment of the present invention;

[0050] Figure 14 yes Figure 13 A magnified view of a section at point H in the middle;

[0051] Figure 15 yes Figure 14 A partial cross-sectional view;

[0052] Figure 16 yes Figure 13 A magnified view of a section at point I;

[0053] Figure 17 yes Figure 16 A partial sectional view.

[0054] In the picture:

[0055] 1. Battery string; 2. Busbar; 4. Insulating strip;

[0056] 11. First solar cell; 12. Second solar cell; 13. First series solder strip; 14. Second series solder strip;

[0057] 31. First weld strip; 32. Second weld strip;

[0058] 311. First main body section; 312. First connecting section;

[0059] 321. Second main body section; 322. Second connecting section;

[0060] 331. Third main body section; 332. Bending section; 333. Third connecting section;

[0061] 100, baseline; 200, centerline. Detailed Implementation

[0062] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0064] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0065] Example 1

[0066] like Figures 1 to 7 As shown, this embodiment provides a solar cell module that solves the problems of low bifaciality and high power loss caused by the large area of ​​a single cell being blocked by the busbar 2. The solar cell module includes a cell string 1, a busbar 2, and solder strips.

[0067] Among them, see Figure 1 and Figure 2 The battery string 1 includes multiple battery cells arranged sequentially and connected in series along a first direction. The solar cell module has a reference line 100. The multiple battery cells include a first battery cell 11 and a second battery cell 12 arranged sequentially with the reference line 100 as the starting point. A busbar 2 is disposed on the back surface of the second battery cell 12 and located near the end of the first battery cell 11. The orthographic projection of the busbar 2 covers the end of the first battery cell 11 near the second battery cell 12. The busbar 2 extends along a second direction, which intersects the first direction. (See reference...) Figure 4 The length of busbar 2 in the first direction is W, where 0.2 ≤ L1 / W ≤ 0.8; and L1 is the length of busbar 2 in the first direction from the centerline 200 between the first solar cell 11 and the second solar cell 12 to the edge of busbar 2. A solder strip is disposed on the back surface of the first solar cell 11 for electrically connecting the first solar cell 11 and busbar 2.

[0068] The solar cell module provided in this embodiment of the invention has a busbar 2 arranged on the back surface of the second cell 12 and covering the end of the first cell 11 near the second cell 12. In a first direction, the length L1 of the busbar 2 from the centerline 200 between the first and second cells 11 to the edge of the busbar 2 satisfies 0.2 ≤ L1 / W ≤ 0.8 with respect to the total length W of the busbar 2. That is, in the first direction, the orthographic projection of the busbar 2 covers both the first cell 11 and the second cell 12, allowing the shading area of ​​the busbar 2 to be distributed across both cells, thereby reducing the area of ​​a single cell shaded by the busbar 2. Compared to existing solutions where the busbar 2 is only arranged on a single cell, this improves the bifaciality of the solar cell module, thereby increasing the overall power of the solar cell module and ensuring the energy conversion efficiency of the photovoltaic system. In addition, placing the busbar 2 on the backlight surface of the first solar cell 11 and the second solar cell 12 can hide the busbar 2, ensuring the maximum light-receiving surface of the solar cell while maintaining the aesthetics of the solar cell module.

[0069] In this embodiment, the first direction is perpendicular to the second direction, as shown in the reference. Figure 1 and Figure 2 The orientation of the cell can be either the width of the cell or the length of the cell.

[0070] The solar cell module provided in this embodiment, by designing the orthographic projection of the busbar 2 to simultaneously cover the first solar cell 11 and the second solar cell 12, can improve the bifaciality by more than 3% compared to the existing busbar 2 design scheme, that is, the busbar 2 is only arranged on a single solar cell.

[0071] Optionally, the area of ​​the busbar 2 covering the first solar cell 11 by its orthographic projection is equal to the area covering the second solar cell 12. That is, the relationship between the length W of the busbar 2 in the first direction and L1 is L1 / W=0.5. The busbar 2 is symmetrically arranged about the centerline 200 between the first solar cell 11 and the second solar cell 12, so that the shading area of ​​the busbar 2 is evenly distributed on the first solar cell 11 and the second solar cell 12, effectively reducing the area of ​​a single solar cell shaded by the busbar 2, thereby improving the bifaciality of the solar cell module, increasing the overall power of the solar cell module, and ensuring the energy conversion efficiency of the photovoltaic system.

[0072] The table below shows the bifaciality and overall power data of solar cell modules obtained from actual tests on busbar 2 arrangement dimensions within the range of 0.1≤L1 / W≤1.0.

[0073]

[0074] The data above shows that when the dimensions W and L1 of the busbar 2 in the first direction satisfy 0.2≤L1 / W≤0.8, the bifaciality of the solar cell module can reach over 62%, and the overall power of the solar cell module can reach over 516 watts. Compared with the existing scheme where the busbar 2 is only arranged on a single cell, this can improve the bifaciality of the solar cell module and the overall power of the solar cell module.

[0075] When the dimension W of the busbar 2 in the first direction satisfies L1 / W=0.5 with L1, the bifaciality is highest, reaching 65.11%; the overall power of the module is also highest, reaching 518.47 watts. In other words, symmetrically arranging the busbar 2 with the centerline 200 of the first and second solar cells 11 as the axis of symmetry effectively reduces the area of ​​a single solar cell obstructed by the busbar 2, effectively improving the bifaciality of the solar module, thereby increasing the overall power of the solar module.

[0076] It is understandable that in the actual design of solar cells, the specific value of L1 / W can be selected according to the design requirements, and is not limited to the values ​​listed above.

[0077] In some implementation examples, such as Figure 1 As shown, baseline 100 is located at the end of the solar cell module. (Combined with...) Figure 2 Starting from the baseline 100 at the end, refer to Figure 1 and Figure 2 In the orientation, baseline 100 is located at the right end of the solar cell module, and the first and second solar cells from right to left are the first solar cell 11 and the second solar cell 12, respectively. In other embodiments, refer to... Figure 1 and Figure 2In terms of orientation, baseline 100 can also be located at the left end of the solar cell module.

[0078] See Figure 1 , Figure 2 , Figure 3 and Figure 4 When the reference line 100 is located at the end of the solar cell module, the solder strip includes a first solder strip 31. The first solder strip 31 includes a connected first main body segment 311 and a first connecting segment 312. The first main body segment 311 is electrically connected to the first cell 11, and the first connecting segment 312 overlaps with and is electrically connected to the busbar 2 in a first direction. The first main body segment 311 is electrically connected to the effective welding position of the first cell 11, and the first connecting segment 312 extends along the first direction to the area where the busbar 2 is located, ensuring sufficient connection length between the first solder strip 31 and the busbar 2 to guarantee reliable electrical connection. By electrically connecting the first cell 11 to the busbar 2 through the first solder strip 31, the current of the cell string 1 can be collected from the first cell 11 at the end via the first solder strip 31 to the busbar 2, and then the current of the cell string 1 can be drawn out through the busbar 2.

[0079] For example, the first solder strip 31 can be electrically connected to the first battery cell 11 and the busbar 2 by means of welding, conductive adhesive bonding, etc., but is not limited to the electrical connection methods listed above.

[0080] Optionally, see Figure 4 The overlap length between the solder ribbon (first solder ribbon 31) and the busbar 2 in the first direction is D1, where L1 / 4 ≤ D1 < L1, and L1 is the length of the orthographic projection of the busbar 2 onto the first solar cell 11 along the first direction. This dimensional design ensures sufficient connection length between the first solder ribbon 31 and the busbar 2, guaranteeing welding tensile strength and preventing desoldering due to vibration, thermal expansion and contraction, or external forces, thus improving electrical connection stability. Simultaneously, it avoids excessive overlap between the first solder ribbon 31 and the busbar 2, preventing multiple overlapping layers below the area where the first connection segment 312 is located. This reduces the number of overlapping layers in the busbar 2 area, decreasing the thickness of the connection area between the first solder ribbon 31 and the busbar 2, reducing the risk of microcracks and fragmentation of the solar cell at the busbar 2 location, and improving the yield and reliability of the solar cell module.

[0081] For example, the overlap length D1 between the first solder strip 31 and the busbar 2 in the first direction can be D1=L1 / 2. In other embodiments, it can also be D1=L1 / 4, D1=L1 / 3, D1=2L1 / 3, D1=3L1 / 4, etc., but is not limited to the specific values ​​listed above.

[0082] In this embodiment, L1 is less than the distance from the edge of the first battery cell 11 to its nearest first pad, so as to reserve a certain amount of space to ensure that the first solder strip 31 can be soldered to the pad on the first battery cell 11, and that the first solder strip 31 can extend to the area where the busbar 2 is located after being soldered to the pad of the first battery cell 11.

[0083] Optionally, the solder strip (first solder strip 31) extends at least partially above the busbar 2 to overlap and electrically connect with the busbar 2 in a first direction. See also Figure 2 , Figure 3 and Figure 4 The solder strip is a first solder strip 31, and the busbar 2 is an end busbar. The first solder strip 31 extends to the busbar 2 and is located above the busbar 2, so that the first solder strip 31 overlaps with the busbar 2 in the first direction. The first solder strip 31 is stacked on top of the busbar 2, which can increase the contact area between the two, reduce the contact resistance, thereby reducing power loss and improving the conversion efficiency of the solar cell module.

[0084] In some embodiments, such as Figure 1 As shown, baseline 100 is located in the middle of the solar cell module. (Combined with...) Figure 5 Starting from the baseline of 100 in the middle, refer to Figure 1 and Figure 5 In the orientation of the solar cell module, the reference line 100 is located in the middle of the solar cell module, and the first and second cells from left to right along the reference line 100 are the first cell 11 and the second cell 12, respectively.

[0085] See Figure 1 , Figure 5 and Figure 6 When the reference line 100 is located in the middle of the solar cell module, the solder strip includes a second solder strip 32. The solar cell module includes a parallel battery string group, which includes at least two battery strings 1 located on both sides of the reference line 100 and connected in parallel. The first cells 11 of the two battery strings 1 on both sides of the reference line 100 are arranged adjacent to each other. The second solder strip 32 is used to electrically connect the busbar 2 and the two first cells 11 on both sides of the reference line 100. By electrically connecting the two first cells 11 on both sides of the reference line 100 to the busbar 2 through the second solder strip 32, the two battery strings 1 on both sides of the reference line 100 are connected in parallel, and the current of the two battery strings 1 is collected to the middle busbar 2, and then the current of the two battery strings 1 is led out through the busbar 2.

[0086] Optionally, see Figure 5 , Figure 6 and Figure 7The second welding strip 32 includes a connected second main body segment 321 and a second connecting segment 322. The second main body segment 321 is electrically connected to the first battery cell 11, and the second connecting segment 322 overlaps with and is electrically connected to the busbar 2 in a first direction. Specifically, the second main body segment 321 is electrically connected to the effective welding positions of the two first battery cells 11 on both sides of the reference line 100, and the second connecting segment 322 extends along the first direction to the area where the busbar 2 is located, ensuring sufficient connection length between the second welding strip 32 and the busbar 2 and guaranteeing reliable electrical connection.

[0087] For example, the second welding strip 32 can be electrically connected to the first battery cell 11 and the busbar 2 by means of welding, conductive adhesive bonding, etc., but is not limited to the electrical connection methods listed above.

[0088] Optionally, see Figure 7 The overlap length between the second solder strip 32 and the busbar 2 in the first direction is D1, where L1 / 4 ≤ D1 < L1, and L1 is the length of the orthographic projection of the busbar 2 onto the first solar cell 11 along the first direction. This dimensional design ensures sufficient connection length between the second solder strip 32 and the busbar 2, guaranteeing welding tensile strength and preventing desoldering due to vibration, thermal expansion and contraction, or external forces, thus improving electrical connection stability. Simultaneously, it avoids excessive overlap between the second solder strip 32 and the busbar 2, preventing multiple overlapping layers below the area where the second connection segment 322 is located. This reduces the number of overlapping layers in the busbar 2 area, decreasing the thickness of the connection area between the second solder strip 32 and the busbar 2, reducing the risk of microcracks and fragmentation of the solar cell at the busbar 2 location, and improving the yield and reliability of the solar cell module.

[0089] For example, the overlap length D1 between the second solder strip 32 and the busbar 2 in the first direction can be D1=L1 / 2. In other embodiments, it can also be D1=L1 / 4, D1=L1 / 3, D1=2L1 / 5, D1=3L1 / 5, D1=2L1 / 3, D1=3L1 / 4, etc., but is not limited to the specific values ​​listed above.

[0090] Optionally, the solder strip (second solder strip 32) extends at least partially above the busbar 2 to overlap with and be electrically connected to the busbar 2 in a first direction. See also Figure 5 , Figure 6 and Figure 7 The solder strip is the second solder strip 32, and the busbar 2 is the middle busbar. The second solder strip 32 extends to the busbar 2 and is located above the busbar 2, so that the second solder strip 32 overlaps with the busbar 2 in the first direction. The second solder strip 32 is stacked above the busbar 2, which can increase the contact area between the two, reduce the contact resistance, thereby reducing power loss and improving the conversion efficiency of the solar cell module.

[0091] In some embodiments, such as Figure 3 and Figure 4 As shown, the first solar cell 11 and the second solar cell 12 at least partially overlap in the first direction to form an overlapping area, and the orthographic projection of the busbar 2 covers the overlapping area. That is, the first solar cell 11 and the second solar cell 12 adopt a stacked design, with an overlapping area between every two adjacent solar cells, making the front of the solar cell string 1 seamless. This allows for better concealment of the busbar 2, solder ribbons, etc., on the back of the solar cells, resulting in a smoother appearance. At the same time, the stacked design reduces the ineffective area between solar cells, allowing more solar cells to be accommodated within the same area of ​​the solar cell module, thereby improving the overall output power of the solar cell module.

[0092] See Figure 4 When the first battery cell 11 and the second battery cell 12 overlap at least partially in the first direction, the center line 200 is the center line of the overlapping area of ​​the first battery cell 11 and the second battery cell 12. That is, the center line 200 is located in the exact middle of the overlapping area, and the center line 200 is the axis of symmetry of the overlapping area along the second direction, and the first battery cell 11 and the second battery cell 12 are symmetrical about the center line 200.

[0093] In some embodiments, the first battery cell 11 and the second battery cell 12 may be designed to be arranged adjacent to each other while maintaining a preset distance. That is, the first battery cell 11 and the second battery cell 12 are arranged at intervals.

[0094] When the first battery cell 11 and the second battery cell 12 are spaced apart, the center line 200 is the center line of the spaced area between the first battery cell 11 and the second battery cell 12. That is, the center line 200 is located in the exact middle of the spaced area, and the center line 200 is the axis of symmetry of the spaced area along the second direction. The first battery cell 11 and the second battery cell 12 are symmetrical about the center line 200.

[0095] Optionally, the battery string 1 also includes series solder strips, in which every two adjacent battery cells are connected by series solder strips in the first direction. That is, multiple battery cells are connected in series by series solder strips to form the battery string 1. See reference. Figure 2 and Figure 3 The tandem solder strips include a first tandem solder strip 13 and a second tandem solder strip 14, specifically... Figure 2 In the first series welding strip 13 and the second series welding strip 14 both extend along the first direction. The first battery cell 11 and the second battery cell 12 are connected in series through the first series welding strip 13, and the second battery cell 12 is connected in series with the battery cell adjacent to its left through the second series welding strip 14.

[0096] Optionally, see Figure 3 and Figure 4The solar cell module also includes an insulating strip 4, which is disposed on the back surface of the second cell 12 and located between the busbar 2 and the second cell 12. The orthographic projection of the insulating strip 4 covers the end of the first cell 11 closest to the second cell 12, and the orthographic projection of the busbar 2 lies within the orthographic projection of the insulating strip 4. This arrangement allows the insulating strip 4 to completely insulate the busbar 2 from the first series solder ribbon 13, and simultaneously insulate the first solder ribbon 31 from the second series solder ribbon 14 on the second cell 12, preventing short circuits and improving the reliability of the solar cell module.

[0097] In some embodiments, the insulating strip may also be insulating adhesive printed on the battery cell, irregular solder strip, and grid line.

[0098] Optionally, see Figure 1 , Figure 2 and Figure 3 The solar cell is rectangular, with two sides in a first direction, namely the first side and the second side. Chamfers are provided at both ends of the first side and / or the second side. Solar cells typically have right angles after cutting, which can easily create stress concentration areas. Chamfers eliminate sharp edges, reducing the probability of chipping or breakage during subsequent processing (such as transportation and lamination), and improving the mechanical strength of the solar cell.

[0099] In some embodiments, chamfers may be provided only at both ends of the first or second side of the battery cell. The first and second sides of two adjacent battery cells are arranged adjacently, such that the chamfered side of the previous battery cell is adjacent to the non-chamfered side of the next battery cell. Multiple battery cells can be connected in series to form a battery string 1, and battery strings 1 can be connected in series or in parallel. Alternatively, the first (second) sides of two adjacent battery cells may be arranged adjacently, that is, the chamfered sides of the two battery cells are arranged adjacently, and the non-chamfered sides are arranged opposite each other.

[0100] Furthermore, by setting chamfers at both ends of the first or second side, the two sides of the battery cell can be distinguished when assembling the battery string 1, so that the chamfered side and the non-chamfered side of the adjacent battery cell are arranged in sequence, or the chamfered side of the adjacent battery cell is adjacent or opposite to each other, which can simplify the assembly process and reduce the assembly difficulty.

[0101] In some embodiments, chamfers may be provided at both ends of the first and second sides of the battery cell.

[0102] Optionally, the dimension of the solar cell in the first direction is X, and the value of X is in the range of 88mm≤X≤110mm. For example, X can be 88mm, 90mm, 92mm, 95mm, 97mm, 100mm, 102mm, 105mm, 108mm, 110mm, etc., but is not limited to the values ​​listed above. The value of X can be selected adaptively according to the actual situation.

[0103] Optionally, the dimension of the solar cell in the second direction is Y, and the value of Y ranges from 166mm to 220mm. For example, Y can take values ​​of 166mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, 200mm, 105mm, 210mm, 215mm, 220mm, etc., but is not limited to the values ​​listed above. The value of Y can be selected adaptively according to the actual situation.

[0104] Optionally, the solar cell module includes at least one series-connected cell string group, which comprises two cell strings 1 arranged in series along a second direction. Within the same series-connected cell string group, a single busbar 2 extends from the first cell 11 of the first cell string 1 at the beginning of the second direction to the first cell 11 of the last cell string 1 at the end, and the orthographic projection of the busbar 2 overlaps with the second cells 12 of all cell strings 1 in the series-connected cell string group. That is, regardless of the number of cell strings 1, the orthographic projection of the busbar 2 overlaps with the first cells 11 and second cells 12 of all cell strings 1.

[0105] Example 2

[0106] This embodiment provides a solar cell module, which differs from Embodiment 1 in that:

[0107] See Figure 8 , Figure 9 and Figure 10 Busbar 2 is an end busbar, and the solder strip includes a first solder strip 31, which electrically connects the first battery cell 11 to the busbar 2. The first solder strip 31 includes a first main body section 311 and a first connecting section 312 connected together. The first main body section 311 is electrically connected to the first battery cell 11, and the first connecting section 312 overlaps with and is electrically connected to the busbar 2 in a first direction. By electrically connecting the first battery cell 11 to the busbar 2 through the first solder strip 31, the current of the battery string 1 can be collected from the first battery cell 11 at the end through the first solder strip 31 to the busbar 2, and then the current of the battery string 1 can be drawn out through the busbar 2.

[0108] like Figure 9 and Figure 10As shown, the first solder strip 31 extends at least partially below the busbar 2 to overlap and electrically connect with the busbar 2 in a first direction. Specifically, the first connecting segment 312 extends below the busbar 2 along the first direction, ensuring sufficient connection length between the first solder strip 31 and the busbar 2, guaranteeing reliable electrical connection, reducing contact resistance, lowering power loss, and improving the conversion efficiency of the solar cell module. The first solder strip 31 is stacked below the busbar 2, placing the busbar 2 on the outermost layer. The height of both sides of the busbar 2 can remain almost uniform, reducing the height difference between the two sides of the busbar 2, making flatness easier to control, and avoiding problems such as air bubbles or uneven local pressure after lamination due to the protrusion of the first solder strip 31. This ensures a smoother surface and more uniform encapsulation of the solar cell module.

[0109] For example, the first solder strip 31 can be electrically connected to the first battery cell 11 and the busbar 2 by means of welding, conductive adhesive bonding, etc., but is not limited to the electrical connection methods listed above.

[0110] In this embodiment, as Figure 9 As shown, the area where the insulating strip 4 is directly opposite the busbar 2 and the first solder strip 31 is welded is cut off to ensure that the first solder strip 31 can be successfully welded to the busbar 2. By cutting off a portion of the insulating strip 4, the amount of insulating material used can also be reduced, thus lowering costs.

[0111] See Figure 8 , Figure 11 and Figure 12 The welding strip includes a second welding strip 32, which is used to electrically connect the busbar 2 and the two first battery cells 11 on both sides of the central reference line 100. The second welding strip 32 includes a connected second main body section 321 and a second connecting section 322. The second main body section 321 is electrically connected to the first battery cell 11, and the second connecting section 322 overlaps with and is electrically connected to the busbar 2 in a first direction, so that the second welding strip 32 and the busbar 2 have sufficient connection length to ensure reliable electrical connection.

[0112] like Figure 11 and Figure 12 Busbar 2 is a central busbar, and the second solder strip 32 extends at least partially below busbar 2 to overlap and electrically connect with busbar 2 in a first direction. Specifically, the second connecting section 322 extends below busbar 2 along the first direction, ensuring sufficient connection length between the second solder strip 32 and busbar 2 to guarantee reliable electrical connection. The second solder strip 32 is stacked below busbar 2, placing busbar 2 on the outermost layer. This allows the height of both sides of busbar 2 to remain almost uniform, reducing the height difference between the two sides and making flatness easier to control. It avoids problems such as air bubbles or uneven local pressure after lamination due to the protrusion of the second solder strip 32, ensuring a smoother surface and more uniform encapsulation of the solar cell module.

[0113] For example, the second welding strip 32 can be electrically connected to the first battery cell 11 and the busbar 2 by means of welding, conductive adhesive bonding, etc., but is not limited to the electrical connection methods listed above.

[0114] See Figure 10 and Figure 12 The overlap length between the solder strips (first solder strip 31 and second solder strip 32) and the busbar 2 in the first direction is D1, where L1 / 4 ≤ D1 < L1, and L1 is the length of the orthographic projection of the busbar 2 onto the first solar cell 11 along the first direction. This dimensional design ensures sufficient connection length between the first solder strip 31 and the second solder strip 32 and the busbar 2, guaranteeing welding tensile strength and preventing desoldering due to vibration, thermal expansion and contraction, or external forces, thus improving the stability of the electrical connection. Simultaneously, it avoids excessive overlap length between the first solder strip 31 and the second solder strip 32 and the busbar 2, preventing multiple overlapping layers in the connection area between the solder strips and the busbar 2, reducing the risk of microcracks and fragmentation of the solar cell at the busbar 2 location, and improving the yield and reliability of the solar cell module.

[0115] For example, the overlap length D1 between the solder strips (first solder strip 31, second solder strip 32) and the busbar 2 in the first direction can be D1=L1 / 2. In other embodiments, it can also be D1=L1 / 4, D1=L1 / 3, D1=2L1 / 5, D1=3L1 / 5, D1=2L1 / 3, D1=3L1 / 4, etc., but is not limited to the specific values ​​listed above.

[0116] The solar cell module provided in this embodiment, by designing the orthographic projection of the busbar 2 to simultaneously cover the first solar cell 11 and the second solar cell 12, can improve the bifaciality by more than 3% compared to the existing busbar 2 design scheme, that is, the busbar 2 is only arranged on a single solar cell.

[0117] Example 3

[0118] This embodiment provides a solar cell module, which differs from Embodiments 1 and 2 in that:

[0119] See Figure 13 , Figure 14 and Figure 15Busbar 2 is an end busbar 2, and the solder strip is a first solder strip 31. The first solder strip 31 includes a third main body section 331, a bent section 332, and a third connecting section 333. The third main body section 331 is electrically connected to the first solar cell 11. The third connecting section 333 is bent and connected to the third main body section 331 through the bent section 332. The third connecting section 333 and the third main body section 331 are staggered in the second direction. The third connecting section 333 overlaps with and is electrically connected to the busbar 2 in the first direction. This arrangement reduces the overlap structure below the welding area of ​​the first solder strip 31 and the busbar 2. For the cell string 1, the height of at least one solder strip can be reduced, and the thickness of the connection area between the first solder strip 31 and the busbar 2 can be reduced. This reduces the risk of microcracks and fragmentation of the solar cell at the busbar 2 location, and improves the yield and reliability of the solar cell module.

[0120] See Figure 13 , Figure 16 and Figure 17 Busbar 2 is a central busbar, and the solder strip is a second solder strip 32. The second solder strip 32 includes a third main body section 331, a bent section 332, and a third connecting section 333. The third main body section 331 is electrically connected to the first solar cell 11. The third connecting section 333 is bent and connected to the third main body section 331 through the bent section 332. The third connecting section 333 and the third main body section 331 are staggered in the second direction. The third connecting section 333 overlaps with and is electrically connected to busbar 2 in the first direction. This arrangement reduces the overlap structure below the welding area of ​​the second solder strip 32 and busbar 2, which can reduce the risk of microcracks and fragmentation of the solar cell at the location of busbar 2, and improve the yield and reliability of the solar cell module.

[0121] like Figure 14 , Figure 15 , Figure 16 and Figure 17 As shown, the welding strip is bent so that the third connecting segment 333 of the welding strip can completely overlap with the busbar 2 in the first direction, ensuring that the connection length between the welding strip and the busbar 2 is long enough and improving the connection reliability.

[0122] Example 4

[0123] This embodiment provides a photovoltaic system, including solar cell modules as described in any of the above embodiments. The photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. In other embodiments, the photovoltaic system can also be applied to equipment that utilizes solar energy for power generation, such as solar power supplies, solar streetlights, and solar buildings, but is not limited to the application scenarios listed above. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0124] The photovoltaic system provided in this embodiment, by adopting the aforementioned solar cell modules, can ensure the energy conversion efficiency of the photovoltaic system and improve the overall power due to the increased bifaciality of the solar cell modules.

[0125] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A solar cell module, characterized by, The utility model relates to a solar cell module, comprising: a battery string (1) comprising a plurality of battery pieces arranged in sequence along a first direction and connected in series, the solar cell module having a reference line (100), the plurality of battery pieces comprising a first battery piece (11) and a second battery piece (12) arranged in sequence with the reference line (100) as a starting point; a bus bar (2) arranged on a back surface of the second battery piece (12) and located at one end close to the first battery piece (11), the bus bar (2) covering the first battery piece (11) at one end close to the second battery piece (12) in orthographic projection, the bus bar (2) extending along a second direction intersecting the first direction; a length of the bus bar (2) in the first direction being W, 0.2<=L1 / W<=0.8; wherein L1 is a length of the bus bar (2) in the first direction from a center line (200) of the first battery piece (11) and the second battery piece (12) to an edge of the bus bar (2); a solder strip arranged on a back surface of the first battery piece (11) for electrically connecting the first battery piece (11) and the bus bar (2); the solder strip at least partially extending above the bus bar (2) to overlap and electrically connect the bus bar (2) in the first direction, or the solder strip at least partially extending below the bus bar (2) to overlap and electrically connect the bus bar (2) in the first direction; an overlapping length of the solder strip and the bus bar (2) in the first direction being D1, L1 / 4<=D1 the first battery piece (11) and the second battery piece (12) being arranged adjacent to each other and maintaining a preset distance, or the first battery piece (11) and the second battery piece (12) at least partially overlapping in the first direction to form an overlapping region, the orthographic projection of the bus bar (2) covering the overlapping region; when the first battery piece (11) and the second battery piece (12) at least partially overlap in the first direction, the center line (200) being a center line of the overlapping region of the first battery piece (11) and the second battery piece (12); when the first battery piece (11) and the second battery piece (12) are arranged at intervals, the center line (200) being a center line of an interval region of the first battery piece (11) and the second battery piece (12).

2. The solar cell module according to claim 1, characterized by the reference line (100) being located at an end of the solar cell module; or the reference line (100) being located at a middle of the solar cell module.

3. The solar cell module according to claim 2, characterized by when the reference line (100) is located at an end of the solar cell module, the solder strip comprising a first solder strip (31), the first solder strip (31) comprising a first main body segment (311) and a first connecting segment (312) connected in sequence, the first main body segment (311) being electrically connected to the first battery piece (11), the first connecting segment (312) overlapping and electrically connected to the bus bar (2) in the first direction.

4. The solar cell module according to claim 2, characterized by The solder strip includes a second solder strip (32) when the reference line (100) is located in the middle of the solar cell module, the solar cell module includes a parallel cell string group, the parallel cell string group includes at least two cell strings (1) arranged on two sides of the reference line (100) in parallel, first cell pieces (11) of the two cell strings (1) on two sides of the reference line (100) are arranged adjacently, and the second solder strip (32) is used for electrically connecting the bus bar (2) and the two first cell pieces (11) on two sides of the reference line (100). The second solder strip (32) includes a second main body segment (321) and a second connecting segment (322) connected with each other, the second main body segment (321) is electrically connected with the first cell piece (11), and the second connecting segment (322) overlaps and is electrically connected with the bus bar (2) in the first direction.

5. The solar cell module according to claim 1, characterized by The solder strip includes a third main body segment (331), a bending segment (332) and a third connecting segment (333), the third main body segment (331) is electrically connected with the first cell piece (11), the third connecting segment (333) is connected with the third main body segment (331) through the bending segment (332), the third connecting segment (333) and the third main body segment (331) are arranged in a staggered manner in the second direction, and the third connecting segment (333) overlaps and is electrically connected with the bus bar (2) in the first direction.

6. The solar cell module according to any one of claims 1 to 5, wherein The area of the orthographic projection of the bus bar (2) covering the first cell piece (11) is equal to the area of the orthographic projection of the bus bar (2) covering the second cell piece (12).

7. The solar cell module according to any one of claims 1 to 5, wherein The solar cell module further includes an insulation strip (4), the insulation strip (4) is arranged on a back light surface of the second cell piece (12) and between the bus bar (2) and the second cell piece (12), the orthographic projection of the insulation strip (4) covers one end of the first cell piece (11) close to the second cell piece (12), and the orthographic projection of the bus bar (2) is located in the orthographic projection of the insulation strip (4).

8. The solar cell module according to any one of claims 1 to 5, wherein The cell string (1) further includes a series solder strip, and each two adjacent cell pieces are connected through the series solder strip in the first direction.

9. The solar cell module according to any one of claims 1 to 5, wherein The cell piece is rectangular, two side edges of the cell piece in the first direction are a first side edge and a second side edge respectively, and a chamfer is arranged at two ends of the first side edge and / or two ends of the second side edge of the cell piece. The first side edges of two adjacent cell pieces are arranged adjacently, or the first side edges and the second side edges of two adjacent cell pieces are arranged adjacently.

10. The solar cell module according to any one of claims 1 to 5, characterized by, The size of the cell piece in the first direction is X, and the value range of X is 88mm≤X≤110mm. The size of the cell piece in the second direction is Y, and the value range of Y is 166mm≤Y≤220mm.

11. The solar cell module according to any one of claims 1 to 5, characterized by, The solar cell module includes at least one series cell string group, and the series cell string group includes two cell strings arranged in the second direction and connected in series.

12. A photovoltaic system characterized by, The solar cell module includes at least one series cell string group, and the series cell string group includes two cell strings arranged in the second direction and connected in series.

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