Solar cell module and photovoltaic system

Abstract

The invention relates to the technical field of solar cells, and discloses a solar cell module and a photovoltaic system, and the solar cell module comprises a cell string, a bus bar and a welding strip. The battery string comprises a plurality of battery pieces which are connected in series, and the plurality of battery pieces comprise a first battery piece and a second battery piece which are sequentially arranged by taking a reference line as a starting point; the bus bar is arranged on the backlight surface of the second battery piece and located at the end close to the first battery piece, the orthographic projection of the bus bar covers the end, close to the second battery piece, of the first battery piece, and the length W of the bus bar in the first direction and the length L1 of the bus bar from the centering line of the first battery piece and the second battery piece to the edge of the bus bar meet the condition that L1 / W is larger than or equal to 0.2 and smaller than or equal to 0.8; the welding strip is arranged on the backlight surface of the first battery piece and is used for electrically connecting the first battery piece and the bus bar. The shielding area of the bus bar is distributed on the first battery piece and the second battery piece, so that the shielding area of the bus bar on the single battery piece is reduced, the double-sided rate can be improved, and the power loss is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a solar cell module and a photovoltaic system. BACKGROUND

[0002] The back contact cell module generally includes a plurality of cell strings in series and / or parallel, end bus bars arranged at the end area of the cell module, and middle bus bars arranged at the middle area of the cell module, and the current is collected through the bus bars.

[0003] In the related art, the bus bar is arranged on the back surface of the cell piece of the cell string, and the orthographic projection of the bus bar only falls on a single cell piece, that is, the orthographic projection of the bus bar has no overlapping area with the adjacent cell piece, which results in a large shielding area of the single cell piece, increases the current loss between the adjacent two cell pieces or two cell strings during the back surface power test of the cell module, and thus increases the loss of the back surface power of the cell module, which leads to a large decrease in the bifacial rate of the cell module and affects the comprehensive power of the cell module.

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

[0005] Based on the above problems, the purpose of the present application is to provide a solar cell module and a photovoltaic system, which can solve the problems of low bifacial rate and large power loss of the cell module caused by the large shielding area of the bus bar on the single cell piece.

[0006] To achieve the above purpose, the present application adopts the following technical solutions: On the one hand, a solar cell module is provided, comprising: a cell string including a plurality of cell pieces arranged in series along a first direction, the solar cell module having a reference line, and the plurality of cell pieces including a first cell piece and a second cell piece arranged in sequence from the reference line as a starting point; a bus bar arranged on the back surface of the second cell piece and located at one end close to the first cell piece, the orthographic projection of the bus bar covering one end of the first cell piece close to the second cell piece, the bus bar extending along a second direction intersecting the first direction; the length of the bus bar in the first direction is W, and 0.2≤L1 / W≤0.8; wherein L1 is the length of the bus bar in the first direction from the center line of the first cell piece and the second cell piece to the edge of the bus bar; a solder strip arranged on the back surface of the first cell piece for electrically connecting the first cell piece and the bus bar.

[0007] As an optional solution of the solar cell module of the present application, the reference line is located at the end of the solar cell module. Alternatively, the reference line is located at the middle of the solar cell module.

[0008] As an optional solution of the solar cell module of the present application, when the reference line is located at the end of the solar cell module, the solder strip comprises a first solder strip, the first solder strip comprises a first body segment and a first connecting segment connected in sequence, the first body segment is electrically connected with the first cell piece, and the first connecting segment overlaps and is electrically connected with the bus bar in the first direction.

[0009] As an optional solution of the solar cell module of the present application, when the reference line is located at the middle of the solar cell module, the solder strip comprises a second solder strip, the solar cell module comprises a parallel cell string group, the parallel cell string group comprises at least two cell strings arranged in parallel and separately located on both sides of the reference line, and the first cell pieces of the two cell strings on both sides of the reference line are arranged adjacently, the second solder strip is used for electrically connecting the bus bar and the two first cell pieces on both sides of the reference line. The second solder strip comprises a second body segment and a second connecting segment connected in sequence, the second body segment is electrically connected with the first cell piece, and the second connecting segment overlaps and is electrically connected with the bus bar in the first direction.

[0010] As an optional solution of the solar cell module of the present application, the solder strip at least partially extends above the bus bar to overlap and be electrically connected with the bus bar in the first direction. Alternatively, the solder strip at least partially extends below the bus bar to overlap and be electrically connected with the bus bar in the first direction.

[0011] As an optional solution of the solar cell module of the present application, the overlapping length of the solder strip and the bus bar in the first direction is D1, and L1 / 4≤D1

[0012] As an optional solution of the solar cell module of the present application, the solder strip comprises a third body segment, a bending segment and a third connecting segment, the third body segment is electrically connected with the first cell piece, the third connecting segment is connected with the third body segment through the bending segment, the third connecting segment and the third body segment are arranged in a staggered manner in the second direction, and the third connecting segment overlaps and is electrically connected with the bus bar in the first direction.

[0013] As an optional solution of the solar cell module of the present application, the area covered by the bus bar in the orthographic projection is equal to the area covered by the first cell piece.

[0014] As an optional solution of the solar cell module, the first cell piece and the second cell piece are arranged adjacently and keep a preset interval; Alternatively, the first cell piece and the second cell piece at least partially overlap in the first direction to form an overlapping area, and the positive projection of the bus bar covers the overlapping area.

[0015] As an optional solution of the solar cell module, when the first cell piece and the second cell piece at least partially overlap in the first direction, the center line is the center line of the overlapping area of the first cell piece and the second cell piece. When the first cell piece and the second cell piece are arranged at intervals, the center line is the center line of the interval area of the first cell piece and the second cell piece.

[0016] As an optional solution of the solar cell module, the solar cell module further comprises an insulation strip, the insulation strip is arranged on the back surface of the second cell piece and located between the bus bar and the second cell piece, the positive projection of the insulation strip covers one end of the first cell piece close to the second cell piece, and the positive projection of the bus bar is located in the positive projection of the insulation strip.

[0017] As an optional solution of the solar cell module, the cell string further comprises a series welding strip, and in the first direction, each two adjacent cell pieces are connected by the series welding strip.

[0018] As an optional solution of the solar cell module, the cell piece is rectangular, two side edges of the cell piece in the first direction are respectively a first side edge and a second side edge, and a chamfer is arranged at both ends of the first side edge and / or both 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.

[0019] As an optional solution of the solar cell module, the size of the cell piece in the first direction is X, and the value range of X is 88mm≤X≤110mm. And / or, the size of the cell piece in the second direction is Y, and the value range of Y is 166mm≤Y≤220mm.

[0020] As an optional solution of the solar cell module, the solar cell module comprises at least one series cell string group, and the series cell string group comprises two series cell strings arranged along the second direction.

[0021] In another aspect, a photovoltaic system is provided, including the solar cell module as described above.

[0022] The present application has the following advantages: The solar cell module and the photovoltaic system provided by the present application have the following advantages: the busbar is arranged on the back surface of the second cell piece and covers one end of the first cell piece close to the second cell piece, and in the first direction, the length dimension L1 of the busbar from the center line of the first cell piece and the second cell piece to the edge of the busbar satisfies 0.2≤L1 / W≤0.8 between the total length dimension W of the busbar. That is, in the first direction, the orthographic projection of the busbar covers both the first cell piece and the second cell piece, so that the shading area of the busbar can be distributed to the first cell piece and the second cell piece, thereby reducing the area of the single cell piece shaded by the busbar, and compared with the prior art in which the busbar is arranged only on the single cell piece, the bifaciality of the solar cell module can be improved, thereby improving the overall power of the solar cell module and ensuring the energy conversion efficiency of the photovoltaic system. In addition, the busbar is arranged on the back surface of the first cell piece and the second cell piece, so that the busbar can be hidden, the light-receiving surface of the cell piece is maximized, and the aesthetic appearance of the solar cell module is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the contents of the embodiments of the present application and these drawings.

[0024] Figure 1 is a first structural schematic diagram of the solar cell module provided by the present application; Figure 2 is Figure 1 is a partial enlarged view of position A in FIG. 1; Figure 3 is Figure 2 is a partial enlarged view of position C in FIG. 1; Figure 4 is Figure 3 is a partial sectional view of FIG. 1; Figure 5 is Figure 1 is a partial enlarged view of position B in FIG. 1; Figure 6 is Figure 5 is a partial enlarged view of position E in FIG. 1; Figure 7 is Figure 6 is a partial sectional view of FIG. 1; Figure 8is a second structural schematic view of the solar cell module provided by the embodiment of the present application; Figure 9 is Figure 8 is a partial enlarged view at F in the figure; Figure 10 is Figure 9 is a partial sectional view of the figure; Figure 11 is Figure 8 is a partial enlarged view at G in the figure; Figure 12 is Figure 11 is a partial sectional view of the figure; Figure 13 is a third structural schematic view of the solar cell module provided by the embodiment of the present application; Figure 14 is Figure 13 is a partial enlarged view at H in the figure; Figure 15 is Figure 14 is a partial sectional view of the figure; Figure 16 is Figure 13 is a partial enlarged view at I in the figure; Figure 17 is Figure 16 is a partial sectional view of the figure.

[0025] in the figure: 1, cell string; 2, bus bar; 4, insulating strip; 11, first cell piece; 12, second cell piece; 13, first series welding strip; 14, second series welding strip; 31, first welding strip; 32, second welding strip; 311, first main body section; 312, first connecting section; 321, second main body section; 322, second connecting section; 331, third main body section; 332, bending section; 333, third connecting section; 100, reference line; 200, centering line. DETAILED DESCRIPTION

[0026] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects reached more clear, the technical solutions of the embodiments of the present application will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without making creative efforts fall within the protection scope of the present application.

[0027] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0028] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixed connection, or it can be detachable connection; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] Embodiment one

[0030] As shown in Figures 1 to 7 , the present embodiment provides a solar cell module, which can solve the problems of low double-sided rate and large power loss of the solar cell module caused by the large area of the bus bar 2 shielding the single cell. The solar cell module comprises a cell string 1, a bus bar 2 and a solder strip.

[0031] Among them, referring to Figure 1 and Figure 2 , the cell string 1 comprises a plurality of cell pieces arranged in sequence and connected in series along a first direction, and the solar cell module has a reference line 100, and the plurality of cell pieces comprise a first cell piece 11 and a second cell piece 12 arranged in sequence with the reference line 100 as the starting point; the bus bar 2 is arranged on the back light surface of the second cell piece 12 and located at one end close to the first cell piece 11, and the orthographic projection of the bus bar 2 covers one end of the first cell piece 11 close to the second cell piece 12; the bus bar 2 extends along a second direction, and the second direction intersects the first direction. Referring to Figure 4 , the length of the bus bar 2 in the first direction is W, and 0.2≤L1 / W≤0.8; wherein L1 is the length of the bus bar 2 in the first direction from the center line 200 of the first cell piece 11 and the second cell piece 12 to the edge of the bus bar 2. The solder strip is arranged on the back light surface of the first cell piece 11, and is used for electrically connecting the first cell piece 11 and the bus bar 2.

[0032] The solar cell module provided by the embodiment of the present application is characterized in that the busbar 2 is arranged on the back surface of the second cell 12 and covers one end of the first cell 11 close to the second cell 12, and in the first direction, the length dimension L1 of the busbar 2 from the center line 200 of the first cell 11 and the second cell 12 to the edge of the busbar 2 satisfies 0.2≤L1 / W≤0.8, where W is the total length dimension 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, so that the shading area of the busbar 2 can be distributed to the first cell 11 and the second cell 12, thereby reducing the area of the single cell covered by the busbar 2, and compared with the prior art in which the busbar 2 is arranged only on the single cell, the bifaciality of the solar cell module can be improved, thereby improving the overall power of the solar cell module and ensuring the energy conversion efficiency of the photovoltaic system. In addition, the busbar 2 is arranged on the back surface of the first cell 11 and the second cell 12, so that the busbar 2 can be hidden, the light-receiving surface of the cell is maximized, and the aesthetic appearance of the solar cell module is ensured.

[0033] In the embodiment, the first direction is perpendicular to the second direction, and the first direction can be the width direction of the cell and the second direction can be the length direction of the cell, with reference to the orientation in Figure 1 and Figure 2 .

[0034] The solar cell module provided by the embodiment of the present application is characterized in that the busbar 2 is arranged on the back surface of the second cell 12 and covers one end of the first cell 11 close to the second cell 12, and in the first direction, the length dimension L1 of the busbar 2 from the center line 200 of the first cell 11 and the second cell 12 to the edge of the busbar 2 satisfies 0.2≤L1 / W≤0.8, where W is the total length dimension 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, so that the shading area of the busbar 2 can be distributed to the first cell 11 and the second cell 12, thereby reducing the area of the single cell covered by the busbar 2, and compared with the prior art in which the busbar 2 is arranged only on the single cell, the bifaciality of the solar cell module can be improved, thereby improving the overall power of the solar cell module and ensuring the energy conversion efficiency of the photovoltaic system. In addition, the busbar 2 is arranged on the back surface of the first cell 11 and the second cell 12, so that the busbar 2 can be hidden, the light-receiving surface of the cell is maximized, and the aesthetic appearance of the solar cell module is ensured.

[0035] Optionally, the area of the orthographic projection of the busbar 2 covering the first cell 11 is equal to the area of the orthographic projection of the busbar 2 covering the second cell 12. That is, the relationship between the length dimension W of the busbar 2 in the first direction and L1 satisfies L1 / W=0.5, and the busbar 2 is symmetrically arranged with the center line 200 of the first cell 11 and the second cell 12 as the axis of symmetry, so that the shading area of the busbar 2 is distributed to the first cell 11 and the second cell 12, thereby effectively reducing the area of the single cell covered by the busbar 2, improving the bifaciality of the solar cell module, improving the overall power of the solar cell module, and ensuring the energy conversion efficiency of the photovoltaic system.

[0036] The following table is the bifaciality and overall power data of the solar cell module obtained by actual testing of the busbar 2 arrangement size in the range of 0.1≤L1 / W≤1.0.

[0037]

[0038] It can be seen from the above data that when the dimension W of the busbar 2 in the first direction satisfies 0.2≤L1 / W≤0.8 with respect to L1, the bifaciality of the solar cell module can reach above 62%, and the comprehensive power of the solar cell module can reach above 516 watts. Compared with the existing solution in which the busbar 2 is only arranged on a single cell, the bifaciality of the solar cell module can be improved, as well as the comprehensive power of the solar cell module.

[0039] When the busbar 2's dimension W in the first direction satisfies L1 (L1 / W=0.5), the bifaciality reaches its highest, 65.11%, and the module's overall power output also reaches its highest, 518.47 watts. In other words, arranging the busbar 2 symmetrically about the centerline 200 of the first and second solar cells 11, 12 effectively reduces the area of ​​a single solar cell obstructed by the busbar 2, effectively increasing the bifaciality of the solar cell module and, consequently, the module's overall power output.

[0040] It is understandable that in the actual design of solar cells, the specific value of L1 / W can be selected according to design requirements and is not limited to the values ​​listed above.

[0041] In some embodiments, such as Figure 1 As shown, the reference line 100 is located at the end of the solar cell module. Figure 2 , starting from the reference line 100 at the end, refer to Figure 1 and Figure 2 In the orientation, the reference line 100 is located at the right end of the solar cell assembly, and the first and second cells from right to left are the first cell 11 and the second cell 12 respectively. Figure 1 and Figure 2 In the orientation in FIG, the reference line 100 may also be located at the left end of the solar cell assembly.

[0042] See Figure 1 、 Figure 2 、 Figure 3 and Figure 4, the welding strip includes a first welding strip 31, the first welding strip 31 includes a first body segment 311 and a first connecting segment 312 connected to each other, the first body segment 311 is electrically connected to the first cell 11, and the first connecting segment 312 overlaps and is electrically connected to the busbar 2 in the first direction. Wherein, the first body segment 311 is electrically connected to the effective welding position of the first cell 11, and the first connecting segment 312 extends to the area where the busbar 2 is located along the first direction, so that the first welding strip 31 has sufficient connection length with the busbar 2, and the electrical connection reliability is ensured. The first cell 11 and the busbar 2 are electrically connected through the first welding strip 31, so that the current of the cell string 1 can be collected from the first cell 11 at the end to the busbar 2 through the first welding strip 31, and then the current of the cell string 1 is led out through the busbar 2.

[0043] Exemplarily, the electrical connection between the first welding strip 31 and the first cell 11 and the busbar 2 can be realized by welding, conductive glue bonding and the like, but is not limited to the above-mentioned electrical connection modes.

[0044] Optionally, referring to Figure 4 , the overlapping length of the welding strip (the first welding strip 31) and the busbar 2 in the first direction is D1, wherein L1 / 4≤D1

[0045] Exemplarily, the overlapping length D1 of the first welding strip 31 and the busbar 2 in the first direction can be D1=L1 / 2. In other embodiments, D1 can also be D1=L1 / 4, D1=L1 / 3, D1=2L1 / 3, D1=3L1 / 4 and the like, but is not limited to the above-mentioned specific values.

[0046] In the embodiment, L1 is less than the distance from the edge of the first cell 11 to the nearest first pad, so as to reserve a certain amount of space, ensure that the first welding strip 31 can be welded with the pad on the first cell 11, and make the first welding strip 31 extend to the area where the busbar 2 is located after being welded with the pad of the first cell 11.

[0047] Optionally, the solder strip (the first solder strip 31) extends at least partially above the bus bar 2 to overlap and electrically connect with the bus bar 2 in the first direction. Referring to Figure 2 , Figure 3 and Figure 4 , the solder strip is the first solder strip 31, the bus bar 2 is the end bus bar, the first solder strip 31 extends above the bus bar 2 after the bus bar 2, so that the first solder strip 31 overlaps with the bus bar 2 in the first direction. The first solder strip 31 is stacked above the bus bar 2, which can increase the contact area of the two and reduce the contact resistance, thereby reducing power loss and improving the conversion efficiency of the solar cell module.

[0048] In some embodiments, as shown in Figure 1 , the reference line 100 is located in the middle of the solar cell module. In combination with Figure 5 , the reference line 100 in the middle is the starting point, and in combination with the positions in Figure 1 and Figure 5 , the reference line 100 is located in the middle of the solar cell module, and the first and second cell pieces from left to right are the first cell piece 11 and the second cell piece 12, respectively.

[0049] Referring to 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 the second solder strip 32, the solar cell module includes a parallel cell string group, and the parallel cell string group includes at least two cell strings 1 arranged on both sides of the reference line 100 and in parallel, the first cell pieces 11 of the two cell strings 1 on both sides of the reference line 100 are arranged adjacent to each other, and the second solder strip 32 is used to electrically connect the bus bar 2 and the two first cell pieces 11 on both sides of the reference line 100. By electrically connecting the two first cell pieces 11 on both sides of the reference line 100 with the bus bar 2 through the second solder strip 32, the two cell strings 1 on both sides of the reference line 100 are connected in parallel, the current of the two cell strings 1 is collected to the bus bar 2 in the middle, and then the current of the two cell strings 1 is led out through the bus bar 2.

[0050] Optionally, referring to Figure 5 , Figure 6 and Figure 7 , 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. Among them, the second main body segment 321 is electrically connected with the effective soldering position of the two first cell pieces 11 on both sides of the reference line 100, and the second connecting segment 322 extends to the area where the bus bar 2 is located along the first direction, so that the second solder strip 32 has sufficient connection length with the bus bar 2, ensuring the reliability of the electrical connection.

[0051] Exemplarily, the second welding strip 32 can be electrically connected with the first cell 11 and the bus bar 2 by welding, conductive glue bonding or the like, but is not limited to the above-mentioned electrical connection modes.

[0052] Optionally, referring to Figure 7 , the overlapping length of the second welding strip 32 and the bus bar 2 in the first direction is D1, where L1 / 4≤D1

[0053] Exemplarily, the overlapping length D1 of the second welding strip 32 and the bus bar 2 in the first direction can be D1=L1 / 2. In other embodiments, D1 can also be L1 / 4, D1=L1 / 3, D1=2L1 / 5, D1=3L1 / 5, D1=2L1 / 3, D1=3L1 / 4, etc., but is not limited to the above-mentioned specific values.

[0054] Optionally, the welding strip (the second welding strip 32) extends at least partially above the bus bar 2 to overlap and be electrically connected with the bus bar 2 in the first direction. Referring to Figure 5 , Figure 6 and Figure 7 , the welding strip is the second welding strip 32, the bus bar 2 is the middle bus bar, and the second welding strip 32 extends above the bus bar 2 after extending to the bus bar 2, so that the second welding strip 32 overlaps with the bus bar 2 in the first direction. The second welding strip 32 is stacked above the bus bar 2, which can increase the contact area of the two, reduce the contact resistance, and thus reduce the power loss and improve the conversion efficiency of the solar cell module.

[0055] In some embodiments, as Figure 3 and Figure 4As shown, the first cell tab 11 and the second cell tab 12 at least partially overlap in the first direction to form an overlapping region, and the positive projection of the busbar 2 covers the overlapping region. That is, the first cell tab 11 and the second cell tab 12 adopt a lamination design, and there is an overlapping region between each adjacent two cell tabs, so that the front of the cell string 1 is seamless, and the busbar 2, solder strip and the like on the back of the cell tab can be better hidden, and the appearance is more flat. At the same time, the lamination design can reduce the invalid area between the cell tabs, and more cell tabs can be accommodated in the same area of the solar module, thereby improving the overall output power of the solar module.

[0056] Referring to Figure 4 , when the first cell tab 11 and the second cell tab 12 at least partially overlap in the first direction, the center line 200 is the center line of the overlapping region of the first cell tab 11 and the second cell tab 12. That is, the pair of center lines 200 is located in the middle of the overlapping region, and the center line 200 is the axis of symmetry of the overlapping region in the second direction, and the first cell tab 11 and the second cell tab 12 are symmetrical about the pair of center lines 200.

[0057] In some embodiments, the first cell tab 11 and the second cell tab 12 can also be designed to be arranged adjacent to each other and maintain a preset spacing. That is, the first cell tab 11 and the second cell tab 12 are arranged at intervals.

[0058] When the first cell tab 11 and the second cell tab 12 are arranged at intervals, the center line 200 is the center line of the spacing region of the first cell tab 11 and the second cell tab 12. That is, the pair of center lines 200 is located in the middle of the spacing region, and the center line 200 is the axis of symmetry of the spacing region in the second direction, and the first cell tab 11 and the second cell tab 12 are symmetrical about the pair of center lines 200.

[0059] Optionally, the cell string 1 further comprises a series solder strip, and in the first direction, each adjacent two cell tabs are connected by the series solder strip. That is, the plurality of cell tabs are connected in series by the series solder strip to form the cell string 1. Referring to Figure 2 and Figure 3 , the series solder strip comprises a first series solder strip 13 and a second series solder strip 14, and specifically to Figure 2 , the first series solder strip 13 and the second series solder strip 14 both extend in the first direction, the first cell tab 11 and the second cell tab 12 are connected in series by the first series solder strip 13, and the second cell tab 12 is connected in series with the cell tab adjacent to the left thereof by the second series solder strip 14.

[0060] Optionally, referring to Figure 3 and Figure 4The solar cell module further comprises an insulation strip 4 arranged on the back surface of the second cell piece 12 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. In this way, the insulation strip 4 can completely insulate and separate the bus bar 2 from the first series of solder strips 13, and insulate and separate the first solder strip 31 from the second series of solder strips 14 on the second cell piece 12, thereby preventing short circuit and improving the reliability of the solar cell module.

[0061] In some embodiments, the insulation strip can also be an insulation glue printed on the cell piece, the male solder strip and the grid line.

[0062] Optionally, referring to Figure 1 , Figure 2 and Figure 3 , 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 the cell piece is provided with a chamfer at both ends of the first side edge and / or both ends of the second side edge. The cell piece usually has a right angle after being cut, and the right angle is prone to have a stress concentration area. By providing a chamfer, the sharp part can be eliminated, the probability of edge collapse or fragmentation during subsequent processing (such as transportation and lamination) of the cell can be reduced, and the mechanical strength of the cell piece can be improved.

[0063] In some embodiments, the chamfer can be provided only at both ends of the first side edge or the second side edge of the cell piece. The first side edge and the second side edge of adjacent two cell pieces are arranged adjacently, so that the side edge with the chamfer of the previous cell piece is adjacent to the side edge without the chamfer of the next cell piece. A plurality of cell pieces can be connected in series to form a cell string 1, and the cell strings 1 can be connected in series or in parallel. Alternatively, the first side edge (the second side edge) of adjacent two cell pieces can be arranged adjacently, i.e., the side edges with the chamfers of the two cell pieces are arranged adjacently, and the side edges without the chamfers are arranged oppositely.

[0064] In addition, by providing the chamfer at both ends of the first side edge or the second side edge, the two side edges of the cell piece can be distinguished during assembly of the cell string 1, so that the side edges with the chamfers of adjacent cell pieces are arranged in sequence with the side edges without the chamfers, or the side edges with the chamfers of adjacent cell pieces are arranged adjacently or oppositely, thereby simplifying the assembly process and reducing the assembly difficulty.

[0065] In some embodiments, the chamfer can be provided at both ends of the first side edge and the second side edge of the cell piece.

[0066] Optionally, the size of the battery piece in the first direction is X, and the value range of X is 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 above-mentioned values, and the value of X can be adaptively selected according to the actual situation.

[0067] Optionally, the size of the battery piece in the second direction is Y, and the value range of Y is 166mm≤Y≤220mm. For example, Y can be 166mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, 200mm, 105mm, 210mm, 215mm, 220mm, etc., but is not limited to the above-mentioned values, and the value of Y can be adaptively selected according to the actual situation.

[0068] Optionally, the solar cell module comprises at least one series battery string group, and the series battery string group comprises two battery strings 1 arranged in series along the second direction. In the same series battery string group, the same bus bar 2 extends from the first battery piece 11 of the battery string 1 at the first end of the second direction to the first battery piece 11 of the battery string 1 at the end, and the projection of the bus bar 2 overlaps with the second battery piece 12 of all battery strings 1 in the series battery string group. That is, no matter how many battery strings 1, the projection of the bus bar 2 overlaps with the first battery piece 11 and the second battery piece 12 of all battery strings 1.

[0069] Embodiment two

[0070] The embodiment provides a solar cell module, which is different from the embodiment one in that: Referring to Figure 8 , Figure 9 and Figure 10 , the bus bar 2 is an end bus bar, and the welding strip comprises a first welding strip 31, and the first battery piece 11 is electrically connected with the bus bar 2 through the first welding strip 31. The first welding strip 31 comprises a first main body segment 311 and a first connecting segment 312 connected with each other, the first main body segment 311 is electrically connected with the first battery piece 11, and the first connecting segment 312 overlaps with the bus bar 2 in the first direction and is electrically connected with the bus bar 2. The first battery piece 11 is electrically connected with the bus bar 2 through the first welding strip 31, so that the current of the battery string 1 can be collected from the first battery piece 11 at the end to the bus bar 2 through the first welding strip 31, and then the current of the battery string 1 is led out through the bus bar 2.

[0071] As Figure 9 and Figure 10As shown, the first solder strip 31 at least partially extends below the bus bar 2 to overlap and electrically connect with the bus bar 2 in the first direction. Specifically, the first connecting segment 312 extends below the bus bar 2 in the first direction, so that the first solder strip 31 has sufficient connection length with the bus bar 2 to ensure electrical connection reliability, reduce contact resistance, reduce power loss, and improve the conversion efficiency of the solar cell module. The first solder strip 31 is stacked below the bus bar 2, so that the bus bar 2 is located at the outermost layer, the height on both sides of the bus bar 2 can be kept almost uniform, the height difference on both sides of the bus bar 2 is reduced, the flatness is easier to control, the problems of bubbles or local uneven pressure after lamination caused by the protrusion of the first solder strip 31 are avoided, the surface of the solar cell module can be ensured to be smoother, and the encapsulation is uniform.

[0072] Exemplarily, the electrical connection between the first solder strip 31, the first cell piece 11 and the bus bar 2 can be achieved by welding, conductive glue bonding or the like, but is not limited to the above-mentioned electrical connection modes.

[0073] In the embodiment, as shown, Figure 9 , the area of the insulating strip 4 opposite the welding area of the bus bar 2 and the first solder strip 31 is cut off to ensure that the first solder strip 31 can be welded with the bus bar 2 smoothly. By cutting off part of the insulating strip 4, the amount of insulating material used can also be reduced, and the cost can be reduced.

[0074] Referring to Figure 8 , Figure 11 and Figure 12 , the solder strip includes a second solder strip 32 for electrically connecting the bus bar 2 and the two first cell pieces 11 on both sides of the reference line 100 in the middle. 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, so that the second solder strip 32 has sufficient connection length with the bus bar 2 to ensure electrical connection reliability.

[0075] As shown in Figure 11 and Figure 12 , the bus bar 2 is a middle bus bar, and the second solder strip 32 at least partially extends below the bus bar 2 to overlap and electrically connect with the bus bar 2 in the first direction. Specifically, the second connecting segment 322 extends below the bus bar 2 in the first direction, so that the second solder strip 32 has sufficient connection length with the bus bar 2 to ensure electrical connection reliability. The second solder strip 32 is stacked below the bus bar 2, so that the bus bar 2 is located at the outermost layer, the height on both sides of the bus bar 2 can be kept almost uniform, the height difference on both sides of the bus bar 2 is reduced, the flatness is easier to control, the problems of bubbles or local uneven pressure after lamination caused by the protrusion of the second solder strip 32 are avoided, the surface of the solar cell module can be ensured to be smoother, and the encapsulation is uniform.

[0076] Exemplarily, the second solder strip 32 can be electrically connected to the first cell 11 and the busbar 2 by welding, conductive glue bonding or the like, but is not limited to the above-mentioned electrical connection modes.

[0077] Referring to Figure 10 and Figure 12 , the overlapping length of the solder strip (the first solder strip 31 and the second solder strip 32) and the busbar 2 in the first direction is D1, wherein L1 / 4≤D1<L1, and L1 is the length of the projection of the busbar 2 on the first cell 11 along the first direction. The size design can make the first solder strip 31 and the second solder strip 32 have sufficient connection length with the busbar 2, ensure the welding tension, avoid the soldering from being detached due to vibration, thermal expansion and contraction or external force, and improve the electrical connection stability. At the same time, it can avoid the overlapping length of the first solder strip 31 and the second solder strip 32 and the busbar 2 being too large, which leads to a large number of overlapping structures in the connection area of the solder strip and the busbar 2, reduces the risk of hidden cracks and fragments of the cell under the busbar 2, and improves the yield and reliability of the solar module.

[0078] Exemplarily, the overlapping length D1 of the solder strip (the first solder strip 31 and 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, and the like, but is not limited to the above-mentioned specific values.

[0079] Compared with the existing busbar 2 design scheme, i.e., the scheme in which the busbar 2 is arranged on a single cell, the bifaciality of the solar module provided in the embodiment can be improved by more than 3% after the projection of the busbar 2 is designed to cover the first cell 11 and the second cell 12.

[0080] Embodiment Three

[0081] The solar module provided in the embodiment is different from the solar module provided in Embodiment One and Embodiment Two in that: Referring to Figure 13 , Figure 14 and Figure 15The busbar 2 is an end busbar 2, and the welding ribbon is a first welding ribbon 31. The first welding ribbon 31 includes a third main section 331, a bent section 332, and a third connecting section 333. The third main section 331 is electrically connected to the first cell 11, and the third connecting section 333 is bent and connected to the third main section 331 via the bent section 332. The third connecting section 333 and the third main section 331 are offset in the second direction. The third connecting section 333 overlaps and is electrically connected to the busbar 2 in the first direction. This arrangement reduces the overlap below the welding area between the first welding ribbon 31 and the busbar 2. For the cell string 1, the height of at least one welding ribbon can be reduced, reducing the thickness of the connection area between the first welding ribbon 31 and the busbar 2. This can reduce the risk of hidden cracks and fragmentation of the cells at the busbar 2 location, thereby improving the yield and reliability of the solar cell module.

[0082] See Figure 13 、 Figure 16 and Figure 17 Busbar 2 is the central busbar, and the welding ribbon is the second welding ribbon 32. The second welding ribbon 32 includes a third main section 331, a bent section 332, and a third connecting section 333. The third main section 331 is electrically connected to the first solar cell 11, and the third connecting section 333 is bent and connected to the third main section 331 via the bent section 332. The third connecting section 333 and the third main section 331 are offset in the second direction. The third connecting section 333 overlaps and is electrically connected to busbar 2 in the first direction. This arrangement reduces the overlap between the second welding ribbon 32 and the busbar 2 below the welding area, reducing the risk of hidden cracks and fragmentation in the solar cells at the busbar 2 location, and improving the yield and reliability of the solar cell module.

[0083] like Figure 14 、 Figure 15 、 Figure 16 and Figure 17 As shown, the soldering ribbon is bent so that the third connecting section 333 of the soldering ribbon can completely overlap with the bus bar 2 in the first direction, ensuring that the connection length between the soldering ribbon and the bus bar 2 is long enough and improving the connection reliability.

[0084] Example 4

[0085] The embodiment provides a photovoltaic system, comprising the solar cell module according to any one of the above embodiments. The photovoltaic system can be applied in a photovoltaic power station, for example, a ground power station, a roof power station, a water surface power station, etc. In other embodiments, the photovoltaic system can also be applied in a device using solar energy to generate power, for example, a solar power supply, a solar street lamp, a solar building, etc., but is not limited to the application scenarios listed above. Taking a photovoltaic power generation system network as an example, the photovoltaic system can comprise a photovoltaic array, a combiner box and an inverter, the photovoltaic array can be an array combination of a plurality of cell modules, for example, a plurality of cell modules can form a plurality of photovoltaic arrays, the photovoltaic arrays are connected to the combiner box, the combiner box can combine the current generated by the photovoltaic arrays, the combined current flows through the inverter to convert into alternating current required by a power grid, and then is connected to a power network, so as to realize solar power supply.

[0086] The photovoltaic system provided by the embodiment can ensure the energy conversion efficiency of the photovoltaic system and improve the overall power, because the bifacial rate of the solar cell module is improved.

[0087] It should be noted that the above are only preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments herein, and those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application 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 and connected in series along a first direction, 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 the back surface of the second battery piece (12) and located at one end close to the first battery piece (11), the orthographic projection of the bus bar (2) covering one end of the first battery piece (11) close to the second battery piece (12); the bus bar (2) extends along a second direction intersecting the first direction; the length of the bus bar (2) in the first direction is W, and 0.2≤L1 / W≤0.8; wherein L1 is the length of the bus bar (2) in the first direction from the center line (200) of the first battery piece (11) and the second battery piece (12) to the edge of the bus bar (2); a solder strip arranged on the back surface of the first battery piece (11) for electrically connecting the first battery piece (11) and the bus bar (2).

2. The solar cell module according to claim 1, characterized by The reference line (100) is located at the end of the solar cell module. Alternatively, the reference line (100) is located at the 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 the end of the solar cell module, the solder strip comprises 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), and the first connecting segment (312) overlapping and being electrically connected to the bus bar (2) in the first direction.

4. The solar cell module according to claim 2, characterized by When the reference line (100) is located at the middle of the solar cell module, the solder strip comprises a second solder strip (32), the solar cell module comprising a parallel battery string group, the parallel battery string group comprising at least two battery strings (1) arranged on both sides of the reference line (100) and connected in parallel, the first battery pieces (11) of the two battery strings (1) on both sides of the reference line (100) being arranged adjacently, and the second solder strip (32) being used for electrically connecting the bus bar (2) and the two first battery pieces (11) on both sides of the reference line (100); the second solder strip (32) comprising a second main body segment (321) and a second connecting segment (322) connected in sequence, the second main body segment (321) being electrically connected to the first battery piece (11), and the second connecting segment (322) overlapping and being electrically connected to the bus bar (2) in the first direction.

5. The solar cell module according to claim 1, characterized by, The solder strip at least partially extends above the bus bar (2) to overlap and be electrically connected to the bus bar (2) in the first direction. Alternatively, the solder strip at least partially extends below the bus bar (2) to overlap and be electrically connected to the bus bar (2) in the first direction.

6. The solar cell module according to claim 5, wherein The overlapping length of the solder strip and the bus bar (2) in the first direction is D1, and L1 / 4≤D1 7. The solar cell module according to claim 1, wherein The solder strip comprises a third main segment (331), a bending segment (332) and a third connecting segment (333), the third main segment (331) is electrically connected with the first battery piece (11), the third connecting segment (333) is connected with the third main segment (331) through the bending segment (332), and the third connecting segment (333) and the third main 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.

8. The solar cell module according to any one of claims 1 to 7, characterized by, The area of the orthographic projection of the bus bar (2) covering the first battery piece (11) is equal to the area of the orthographic projection covering the second battery piece (12).

9. The solar cell module according to any one of claims 1 to 7, characterized by, The first battery piece (11) and the second battery piece (12) are arranged adjacently and maintain a preset interval. Alternatively, the first battery piece (11) and the second battery piece (12) at least partially overlap in the first direction to form an overlapping area, and the orthographic projection of the bus bar (2) covers the overlapping area.

10. The solar cell module according to claim 9, characterized by When the first battery piece (11) and the second battery piece (12) at least partially overlap in the first direction, the centering line (200) is the center line of the overlapping area 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 centering line (200) is the center line of the interval area of the first battery piece (11) and the second battery piece (12).

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

12. The solar cell module according to any one of claims 1 to 7, characterized by, The battery string (1) further comprises a series solder strip, and each two adjacent battery pieces are connected through the series solder strip in the first direction.

13. The solar cell module according to any one of claims 1 to 7, characterized by, The battery piece is rectangular, and two side edges of the battery piece in the first direction are a first side edge and a second side edge, respectively, and the battery piece is provided with a chamfer at both ends of the first side edge and / or both ends of the second side edge. The first side edges of two adjacent battery pieces are arranged adjacently; or the first side edges and the second side edges of two adjacent battery pieces are arranged adjacently.

14. The solar cell module according to any one of claims 1 to 7, characterized by, The size of the battery piece in the first direction is X, and the value range of X is 88mm≤X≤110mm. And / or, the size of the battery piece in the second direction is Y, and the value range of Y is 166mm≤Y≤220mm.

15. The solar cell module according to any one of claims 1 to 7, characterized by, The solar cell module comprises at least one series battery string group, and the series battery string group comprises two battery strings arranged in series along the second direction.

16. A photovoltaic system characterized by, The solar cell module comprises at least one series battery string group, and the series battery string group comprises two battery strings arranged in series along the second direction.

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