Photovoltaic module

Abstract

The present invention provides a photovoltaic module, which comprises a plurality of battery strings. Each battery string includes a plurality of photovoltaic cells arranged in a first direction and conductive members electrically connecting adjacent photovoltaic cells. The edges of adjacent photovoltaic cells overlap. The surface of the photovoltaic cell is provided with a bus electrode extending in the first direction and an edge electrode located at the edge of the photovoltaic cell. The conductive member includes a first conductive segment connected to the bus electrode on the front surface of the photovoltaic cell, a second conductive segment connected to the bus electrode on the back surface of another adjacent photovoltaic cell, and a third conductive segment connected to the edge electrode. At least part of the third conductive segment is clamped in the overlapping area between two adjacent photovoltaic cells. In the photovoltaic module of the present invention, the electrical connection between adjacent photovoltaic cells is more reliable. At the same time, the stress at the edge position of the photovoltaic cell is reduced, the risk of hidden cracks is lowered, and the product quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar power generation, and particularly to a photovoltaic module. Background Art

[0002] In traditional photovoltaic modules, the battery strings are electrically connected to adjacent photovoltaic cells through welding tapes. The above-mentioned welding tape connects the front electrode of one photovoltaic cell to the back electrode of another adjacent photovoltaic cell. To improve the utilization rate of the light-receiving area of photovoltaic modules, major manufacturers have paid great attention to the shingled modules in recent years. The above-mentioned shingled modules overlap adjacent photovoltaic cells at the edge positions, cancel the cell spacing, maximize the utilization of the light-receiving area, and do not need to use welding tapes to connect adjacent photovoltaic cells; however, they still face problems such as high cost of conductive adhesives, poor reliability, and difficulty in rework. In view of the above problems, an "overlap welding" module has been introduced in the industry in recent years. As Figure 1 shown in Figure 2 FIG. , adjacent photovoltaic cells 101 are electrically connected by welding tapes 102, and the edge positions of adjacent photovoltaic cells 101 overlap each other. Although such "overlap welding" modules cancel the cell spacing and make full use of the light-receiving area, the stress at the edge positions of adjacent photovoltaic cells 101 is relatively large, which is likely to cause edge cracks, and there are gaps between adjacent photovoltaic cells 101, and defects such as bubbles and wrinkles may occur during the lamination process.

[0003] In view of this, it is necessary to provide an improved photovoltaic module. Summary of the Invention

[0004] The purpose of the present invention is to provide a photovoltaic module, which can ensure the electrical connection between adjacent photovoltaic cells, reduce the edge stress of photovoltaic cells, improve the edge crack, and improve the product quality.

[0005] To achieve the above-mentioned invention purpose, the present invention provides a photovoltaic module, including a plurality of battery strings. The battery strings include a plurality of photovoltaic cells arranged along a first direction and a conductive member for electrically connecting adjacent photovoltaic cells. The edges of adjacent photovoltaic cells overlap each other. The surface of the photovoltaic cell is provided with a busbar electrode extending along the first direction and an edge electrode located at the edge of the photovoltaic cell; the conductive member includes a first conductive section connected to the busbar electrode on the front surface of the photovoltaic cell, a second conductive section connected to the busbar electrode on the back surface of another adjacent photovoltaic cell, and a third conductive section connected to the edge electrode. At least part of the third conductive section is clamped in the overlapping area between adjacent two photovoltaic cells.

[0006] As a further improvement of the present invention, the third conductive section is connected to both the first conductive section and the second conductive section at the same time.

[0007] As a further improvement of the present invention, the third conductive segment is integrally formed with at least one of the first conductive segment and the second conductive segment.

[0008] As a further improvement of the present invention, the third conductive segment is in the shape of a flat strip, and the third conductive segment has a first part sandwiched between adjacent photovoltaic cells and a second part located outside the overlapping region of adjacent two photovoltaic cells, and the second part is connected to the first conductive segment and the second conductive segment.

[0009] As a further improvement of the present invention, the thickness of the second part does not exceed the thickness of the first part.

[0010] As a further improvement of the present invention, one end of the first conductive segment and / or the second conductive segment facing the third conductive segment is connected to the second part.

[0011] As a further improvement of the present invention, the third conductive segment is entirely sandwiched between adjacent photovoltaic cells.

[0012] As a further improvement of the present invention, the third conductive segment is a continuously arranged flexible conductive material.

[0013] As a further improvement of the present invention, the third conductive segment is a flat welding strip.

[0014] As a further improvement of the present invention, the third conductive segment extends along a second direction perpendicular to the first direction, and the width of the third conductive segment along the first direction is set to be 0.3 - 5 mm; the thickness of the third conductive segment is set to be 0.1 - 0.6 mm.

[0015] As a further improvement of the present invention, the edge electrode is connected to the bus electrode, the edge electrode extends continuously along the second direction, and the second direction is perpendicular to the first direction.

[0016] As a further improvement of the present invention, the edge electrode includes a plurality of dot electrodes arranged at intervals along the second direction, the dot electrodes are connected to one end of the bus electrode close to the overlapping edge, the size of the dot electrodes in the second direction is larger than the size of the bus electrode in the second direction, and the size of the dot electrodes in the first direction is smaller than the overlapping width of adjacent two photovoltaic cells, and the second direction is perpendicular to the first direction.

[0017] As a further improvement of the present invention, the width of the edge electrode along the first direction is set to be 0.2 - 3 mm.

[0018] As a further improvement of the present invention, the edge electrode is in a wavy shape or a sawtooth shape or a square wave shape.

[0019] The beneficial effects of the present invention are as follows: By using the photovoltaic module of the present invention, edge electrodes are arranged on the surface of the photovoltaic cells, and the electrical connection between adjacent photovoltaic cells is realized through the third conductive segments connected to the edge electrodes. At the same time, the first conductive segment and the second conductive segment are used to more effectively collect the surface current of the photovoltaic cells, which can better reduce the stress at the edge position of the photovoltaic cells, reduce the risk of hidden cracks, and also reduce abnormalities such as possible bubbles and wrinkles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 6 is a schematic diagram of the connection structure of adjacent photovoltaic cells in an existing photovoltaic module;

[0021] Figure 2 FIG. Figure 1 is a schematic diagram of the connection of adjacent photovoltaic cells from another angle;

[0022] Figure 3 FIG. 16 is a schematic plan view of a battery string in the photovoltaic module of the present invention;

[0023] Figure 4 FIG. 20 is a front view of a photovoltaic cell of the photovoltaic module of the present invention;

[0024] Figure 5 FIG. Figure 4 is a rear view of the photovoltaic cell in FIG.

[0025] Figure 6 FIG. Figure 4 is a front view of the corresponding monolithic cell of the photovoltaic cell in FIG.

[0026] Figure 7 FIG. 36 is a schematic plan view of the planar connection of adjacent photovoltaic cells in the photovoltaic module of the present invention;

[0027] Figure 8 FIG. Figure 7 is a connection diagram of adjacent photovoltaic cells in FIG.

[0028] Figure 9 FIG. 46 is a front view of another embodiment of a photovoltaic cell of the photovoltaic module of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be described in detail below in conjunction with the embodiments shown in the drawings. However, this embodiment does not limit the present invention, and any structural, method, or functional transformation made by those of ordinary skill in the art based on this embodiment is included in the protection scope of the present invention.

[0030] Refer to Figures 3 to 8As shown, the photovoltaic module provided by the present invention includes a plurality of cell strings 100. The cell strings 100 include a plurality of photovoltaic cells 11 arranged in sequence along a first direction, and conductive members electrically connecting adjacent photovoltaic cells 11. Adjacent photovoltaic cells 11 overlap with each other at the edges to form an overlapping area 110. The arrangement mode of the cell strings 100 and the number of photovoltaic cells 11 in each cell string 100 can be designed according to actual requirements.

[0031] A busbar electrode extending along the first direction is provided on the surface of the photovoltaic cell 11. The busbar electrode includes a front electrode 111 and a back electrode 112 respectively provided on the front and back of the photovoltaic cell 11. Moreover, the photovoltaic cell 11 has two side edges 113 oppositely arranged along the first direction, and the side edges 113 extend along a second direction perpendicular to the first direction. Obviously, fine grids (not shown) for collecting surface current are also provided on the front of the photovoltaic cell 11. When the photovoltaic cell 11 is a bifacial cell, corresponding fine grids are also provided on its back.

[0032] An edge electrode is provided on at least one side surface of the photovoltaic cell 11, adjacent to one of the side edges 113 and located within the overlapping area 110. The edge electrode cooperates with the conductive member to achieve electrical connection between adjacent photovoltaic cells 11. The width of the edge electrode is greater than the width of the aforementioned fine grid. Preferably, the width of the edge electrode along the first direction is set to 0.2 - 3 mm.

[0033] Here, a front edge electrode 114 and a back edge electrode 115 are respectively provided on the front and back of the photovoltaic cell 11, and the front edge electrode 114 and the back edge electrode 115 are respectively provided adjacent to the two side edges 113 of the photovoltaic cell 11. Among them, the front electrode 111 is connected to the front edge electrode 114; the back electrode 112 is connected to the back edge electrode 115. Both the front edge electrode 114 and the back edge electrode 115 continuously extend along the second direction perpendicular to the first direction, and the back edge electrode 115 of the photovoltaic cell 11 corresponds to the position of the front edge electrode 114 of another adjacent photovoltaic cell 11. Here, the ends of the front electrode 111 and the back electrode 112 facing the overlapping area 110 are respectively connected to the front edge electrode 114 and the back edge electrode 115.

[0034] The photovoltaic cell 11 can adopt a monolithic photovoltaic cell or a sub - cell obtained by cutting a monolithic photovoltaic cell. In this embodiment, the photovoltaic cell 11 adopts a half - cell photovoltaic cell (such as Figure 6The master slice shown in [figure] is cut along the dashed line), that is, the photovoltaic cell 11 has a short side extending in the first direction and a long side extending in a second direction perpendicular to the first direction. The long side is the aforementioned side edge 113, and its length is preferably set to 120 - 170 mm. Here, the photovoltaic cell 11 is a multi-busbar cell, and the number of the front electrodes 111 and the back electrodes 112 is set to be not less than 5.

[0035] The conductive member includes a first conductive segment 12 connected to the front electrode 111, a second conductive segment 13 connected to the back electrode 112 of another adjacent photovoltaic cell 11, and a third conductive segment 14 connected to the edge electrode. At least a part of the third conductive segment 14 is clamped between two adjacent photovoltaic cells 11. The length of the first conductive segment 12 in the first direction is adapted to the front electrode 111; the length of the second conductive segment 13 in the first direction is adapted to the back electrode 112. It should be noted that the lengths of the first conductive segment 12 and the second conductive segment 13 can also be set to be less than the lengths of the corresponding front electrode 111 and back electrode 112.

[0036] The first conductive segment 12 and the second conductive segment 13 are used to collect the surface current of the corresponding photovoltaic cell 11, and the first conductive segment 12 and the second conductive segment 13 are set as solder tapes extending in the first direction. The third conductive segment 14 can be made of conductive adhesive, solder paste or other conductive materials with good flexibility, and the third conductive segment 14 is arranged in a continuous flat strip shape. In particular, the first conductive segment 12, the second conductive segment 13 and the third conductive segment can also be made of the same or similar metal conductive materials and are integrally formed.

[0037] The third conductive segment 14 has a first part 141 clamped between two adjacent photovoltaic cells 11 and a second part 142 extending beyond the overlapping region 110. The thickness of the second part 142 is preferably not more than the thickness of the first part 141. Here, the third conductive segment 14 connects the first conductive segment 12 on the surface of one photovoltaic cell 11 and the second conductive segment 13 on the surface of another adjacent photovoltaic cell 11 at the same time. One ends of the first conductive segment 12 and the second conductive segment 13 facing the third conductive segment 14 are connected to the second part 142. In other words, the second part 142 of the third conductive segment 14 can be regarded as two, and are respectively located on both sides of the first part 141 in the first direction. One of the second parts 142 is connected to the first conductive segment 12, and the other second part 142 is connected to the second conductive segment 13.

[0038] With the above design, the electrical connection between adjacent photovoltaic cells 11 is achieved through the third conductive segment 14. The first conductive segment 12 and the second conductive segment 13 do not extend into the overlapping region 110 of adjacent photovoltaic cells 11, avoiding increasing the edge stress of the corresponding photovoltaic cells 11 and preventing possible hidden crack phenomena.

[0039] The extension length of the third conductive segment 14 along the second direction is not less than the distance between the two front electrodes 111 on the surface of the photovoltaic cell 11 that are farthest apart, so that the first conductive segments 12 connected to the front of the corresponding photovoltaic cell 11 can all be connected to the third conductive segment 14. Generally, the front electrodes 111 and the back electrodes 112 on both sides of the photovoltaic cell 11 are arranged in one-to-one correspondence, that is, the first conductive segments 12 and the second conductive segments 13 are arranged in one-to-one correspondence. That is to say, the length of the third conductive segment 14 is not less than the distance between the two first conductive segments 12 that are farthest apart along the second direction, or the distance between the two second conductive segments 13 that are farthest apart. Preferably, the length of the third conductive segment 14 is set to match the length of the edge electrode. In other embodiments of the present invention, the front electrodes 111 and the back electrodes 112 can also be arranged in a staggered manner, and adjacent photovoltaic cells 11 can also be electrically connected through the third conductive segment 14.

[0040] Preferably, the width of the third conductive segment 14 along the first direction is set to 0.3 - 5 mm; the thickness of the third conductive segment is set to 0.1 - 0.6 mm. Of course, the specific specifications of the third conductive segment 14 can be designed according to material properties and product requirements.

[0041] See Figure 9 As shown, the edge electrode can also be designed in a segmented manner. Taking the front edge electrode 114 as an example, the front edge electrode 114 includes a plurality of dot electrodes 1141 arranged at intervals along the second direction. The dot electrodes 1141 are connected to one end of the front electrode 111 facing the overlapping region 110. In other words, the end of each front electrode 111 is connected to a corresponding dot electrode 1141. The size of the dot electrode 1141 in the second direction is larger than the size of the front electrode 111 in the second direction, and the size of the dot electrode 1141 in the first direction is smaller than the width of the overlapping region 110.

[0042] In addition, in other embodiments of the present invention, the edge electrode can also be arranged in a wave shape, a sawtooth shape or a square wave shape to increase its contact area with the third conductive segment, thereby improving the reliability of electrical connection and reducing the edge stress of the photovoltaic cell 11 at the same time.

[0043] In summary, in the photovoltaic module of the present invention, adjacent photovoltaic cells 11 are electrically connected through a third conductive segment 14 connected to the edge electrodes. The first conductive segment 12 and the second conductive segment 13 can more effectively collect the surface current of the photovoltaic cells 11. Moreover, the first conductive segment 12 and the second conductive segment 13 only extend and connect to the second part 142 of the third conductive segment 14, without affecting the overlap of adjacent photovoltaic cells 11, can better reduce the stress at the edge position of the photovoltaic cells 11, lower the risk of hidden cracks, eliminate the gaps existing between adjacent photovoltaic cells 11, and avoid abnormalities such as bubbles and wrinkles that may occur in subsequent processes such as lamination.

[0044] It should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0045] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A photovoltaic module, comprising a plurality of battery strings, characterized in that: The battery string includes a plurality of photovoltaic cells arranged in a first direction and conductive members electrically connecting adjacent photovoltaic cells. The edges of adjacent photovoltaic cells overlap. The surface of the photovoltaic cell is provided with a bus electrode extending in the first direction and an edge electrode located at the edge of the photovoltaic cell. The conductive member includes a first conductive segment connected to the bus electrode on the front surface of the photovoltaic cell, a second conductive segment connected to the bus electrode on the back surface of another adjacent photovoltaic cell, and a third conductive segment connected to the edge electrode. At least a part of the third conductive segment is clamped in the overlapping area between two adjacent photovoltaic cells. The third conductive segment has a first part clamped between adjacent photovoltaic cells and a second part located outside the overlapping area of two adjacent photovoltaic cells. The first part is connected to the edge electrode, and the second part is connected to the first conductive segment and the second conductive segment. The projection of the second part on the photovoltaic cell is within the projection range of the first conductive segment and the second conductive segment on the photovoltaic cell. The first conductive segment and the second conductive segment only extend and connect to the second part of the third conductive segment and do not extend into the overlapping area of adjacent photovoltaic cells. The thickness of the second part is less than the thickness of the first part.

2. The photovoltaic module according to claim 1, characterized in that: The third conductive segment connects the first conductive segment and the second conductive segment at the same time.

3. The photovoltaic module according to claim 1, characterized in that: The third conductive segment is integrally formed with at least one of the first conductive segment and the second conductive segment.

4. The photovoltaic module according to claim 1, characterized in that: The third conductive segment is in the shape of a flat strip.

5. The photovoltaic module according to claim 4, characterized in that: One end of the first conductive segment and / or the second conductive segment facing the third conductive segment is connected to the second part.

6. The photovoltaic module according to claim 1, characterized in that: The entire third conductive segment is clamped between adjacent photovoltaic cells.

7. The photovoltaic module according to claim 1, characterized in that: The third conductive segment is a continuously arranged flexible conductive material.

8. The photovoltaic module according to claim 1, characterized in that: The third conductive segment is a flat welding tape.

9. The photovoltaic module according to claim 1, characterized in that: The third conductive segment extends in a second direction perpendicular to the first direction, and the width of the third conductive segment in the first direction is set to 0.3 - 5 mm; the thickness of the third conductive segment is set to 0.1 - 0.6 mm.

10. The photovoltaic module according to claim 1, characterized in that: The edge electrode is connected to the bus electrode, and the edge electrode extends continuously in the second direction, and the second direction is perpendicular to the first direction.

11. The photovoltaic module according to claim 1, characterized in that: The edge electrode includes a plurality of dot electrodes arranged at intervals in the second direction. The dot electrodes are connected to one end of the bus electrode close to the overlapping edge. The size of the dot electrode in the second direction is larger than the size of the bus electrode in the second direction. The size of the dot electrode in the first direction is smaller than the overlapping width of two adjacent photovoltaic cells. The second direction is perpendicular to the first direction.

12. The photovoltaic module according to claim 1, characterized in that: The width of the edge electrode in the first direction is set to 0.2 - 3 mm.

13. The photovoltaic module according to claim 1, characterized in that: The edge electrode is in a wavy shape or a sawtooth shape or a square wave shape.

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