Solar cell mixed assembly structure

Abstract

The utility model discloses a mixed assembly structure of solar cells, each solar cell is formed by continuously connecting and splicing a plurality of half-cut cells in series through photovoltaic solder strips, and when two adjacent half-cut cells are spliced, a plurality of photovoltaic solder strips are arranged in parallel according to the number of main grids of the half-cut cells to be connected in series. The plurality of photovoltaic welding strips arranged in parallel are divided into two types, namely I-type welding strips and II-type welding strips, the I-type welding strips are distributed on the outermost sides of the two sides of the half-cut battery piece, the II-type welding strips are distributed in the middle of the half-cut battery piece, and the size of the I-type welding strips is smaller than that of the II-type welding strips. Through the above mode, the contact pressure of the photovoltaic welding strip on the two sides of the half-cut battery piece can be reduced, so that the occurrence probability of hidden crack faults at the side edge positions is effectively reduced, and customer complaints are reduced.

Description

Technical Field

[0001] The utility model relates to the field of photovoltaic modules, and particularly to a hybrid assembly structure of solar cells. Background Art

[0002] Due to the multi-busbar design reducing the surface shading of the cell, increasing the light-receiving area, and shortening the conduction distance of the current on the fine grid, the series resistance of the module can be effectively reduced, and the resistance loss can be reduced. The half-cut module can improve the module power while reducing the packaging loss of the module. Under the same shadow occlusion, the special structure design of the half-cut module will reduce the power generation loss of the module in the power station. Therefore, combining the half-cut module with the multi-busbar technology to produce a multi-busbar half-cut module has become a hot direction in this field. However, it is found in actual production that the half-cut multi-busbar cells are sometimes prone to hidden crack problems at both sides during the assembly process, resulting in waste of raw materials. Sometimes, the defective cells flow into the market, which will also cause customer complaint problems. Therefore, it is urgent to propose a suitable solution for the above problems. Summary of the Utility Model

[0003] The main technical problem to be solved by the utility model is to provide a hybrid assembly structure of solar cells, which can improve the assembly stability of photovoltaic modules and reduce the occurrence probability of hidden cracks during the assembly process.

[0004] To solve the above technical problem, a technical solution adopted by the utility model is: providing a hybrid assembly structure of solar cells, the solar cells are continuously connected in series by a plurality of half-cut cells through photovoltaic solder tapes, the number of the photovoltaic solder tapes is the same as the number of main grids on the half-cut cells. When two adjacent half-cut cells are spliced, a plurality of photovoltaic solder tapes are arranged in parallel according to the number of main grids of the half-cut cells for series connection. Each photovoltaic solder tape includes a positive welding section, a negative welding section and a transition section. The negative welding section is welded on the negative main grid of the front half-cut cell, the positive welding section is welded on the positive main grid of the rear half-cut cell, and the transition section connects the positive welding section and the negative welding section. The plurality of parallel photovoltaic solder tapes are divided into two categories, namely type I solder tapes and type II solder tapes. The type I solder tapes are distributed on the outermost sides of both sides of the half-cut cells, and the type II solder tapes are distributed in the middle of the half-cut cells. The size of the type I solder tapes is smaller than the size of the type II solder tapes.

[0005] In a preferred embodiment of the utility model, the sizes of the positive welding section and the negative welding section of the type I solder tapes are respectively 60% - 85% of the sizes of the positive welding section and the negative welding section of the type II solder tapes.

[0006] In a preferred embodiment of the present utility model, the transition section is of a flat structure. The transition angle between the transition section and the positive electrode welding section and the negative electrode welding section is 160° to 170°.

[0007] In a preferred embodiment of the present utility model, the length of the transition section is 8 to 15 mm.

[0008] The beneficial effects of the present utility model are as follows: The present utility model optimizes the series splicing method of existing multi-main-grid solar cells. When welding, the structure of the outermost solder tape is adjusted. By relatively reducing the size of the outermost solder tape, on the one hand, the contact area between the solder tape and the main grid at the edge part of the cell during welding can be reduced. On the other hand, since the solder tape is made of copper, after the size is reduced, the strength per unit length is significantly reduced. In this way, when the cell generates a large stress at the edge position due to overall clamping, the counteracting contact pressure generated between the solder tape and the cell due to the welding process becomes significantly smaller, thereby relieving the internal stress on both sides of the cell and effectively reducing the probability of hidden cracks occurring at the edge position of the cell during the assembly process. Through actual measurement and verification, the probability of the occurrence of hidden crack problems on the side has decreased from 0.8% before to 0.15%, significantly improving the quality stability of the product, and significantly reducing the number of customer complaints regarding hidden crack problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of the assembly structure of a preferred embodiment of the present utility model;

[0010] Figure 2 is a side view structure diagram of the series structure of the shown cell;

[0011] The marks of each component in the drawings are as follows:

[0012] 1. Type I solder tape, 2. Type II solder tape, 3. Cell.

[0013] 101. Type I positive electrode welding section, 102. Type I negative electrode welding section, 103. Type I transition section. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The following elaborates on the preferred embodiments of the present utility model in conjunction with the drawings, so that the advantages and features of the present utility model can be more easily understood by those skilled in the art, thereby making the protection scope of the present utility model more clearly defined.

[0015] Please refer to Figure 1 and Figure 2 , the embodiments of the present utility model include:

[0016] In actual production, the solar cell is formed by continuously connecting and splicing multiple half-cut cell pieces 3 in series through photovoltaic solder tapes. The number of the photovoltaic solder tapes is the same as the number of main grids on the half-cut cell pieces 3. When two adjacent half-cut cell pieces 3 are spliced, multiple photovoltaic solder tapes are arranged in parallel according to the number of main grids on the half-cut cell pieces 3 for series connection. Each photovoltaic solder tape includes a positive welding section, a negative welding section, and a transition section. The negative welding section is welded to the negative main grid of the front half-cut cell piece 3, the positive welding section is welded to the positive main grid of the rear half-cut cell piece 3, the transition section connects the positive welding section and the negative welding section. The positive welding section and the negative welding section are circular light-reflective solder tapes with the same size. The transition section is of a flat structure. The transition angle between the transition section and the positive welding section and the negative welding section is 160°-170°, and the length of the transition section is 8-15 mm. This can reduce the pressure between the bottom edge and the top edge of the half-cut cell piece 3, reduce the assembly spacing of the half-cut cell piece 3, and improve the compactness of the cell assembly structure. In actual assembly, the photovoltaic solder tapes used are divided into two categories, namely type I solder tape 1 and type II solder tape 2. The type I solder tape 1 is distributed on the outermost sides of both sides of the half-cut cell piece 3, and the type II solder tape 2 is distributed in the middle of the half-cut cell piece 3. The sizes of the positive welding section and the negative welding section of the type I solder tape 1 are 60%-85% of the sizes of the positive welding section and the negative welding section of the type II solder tape 2 respectively. In actual design, it is generally reduced by 0.05 mm based on the size of the type II solder tape.

[0017] According to the above content, the implementation examples of the present application are as follows:

[0018] Example 1

[0019] The specification of the half-cut cell piece 3 is 182 mm,

[0020] Type I solder tape 1

[0021] Type I positive welding section 101: The diameter of the solder tape is 0.20 mm, and the length is 83 mm;

[0022] Type I negative welding section 102: The diameter of the solder tape is 0.20 mm, and the length is 80 mm;

[0023] Type I transition section 103: The thickness of the solder tape is 0.15 mm, the length of the solder tape is 10 mm, and the transition angle is 165°;

[0024] Type II solder tape 2

[0025] Type II positive welding section: The diameter of the solder tape is 0.25 mm, and the length is 83 mm;

[0026] Type II negative welding section: The diameter of the solder tape is 0.25 mm, and the length is 80 mm;

[0027] Type II transition section: welding strip thickness 0.15mm welding strip length 10mm transition angle 165°;

[0028] Example 2

[0029] Half-cut cell 3 specifications 210mm

[0030] I-type welding strip 1

[0031] I-type positive electrode welding section 101: welding strip diameter 0.25 mm, length 95 mm;

[0032] I-type negative electrode welding section 102: welding strip diameter 0.25 mm, length 90 mm;

[0033] I-type transition section 103: welding strip thickness 0.15 mm welding strip length 15 mm transition angle 170°;

[0034] Type II welding strip 2

[0035] Type II positive electrode welding section 1: welding strip diameter 0.3mm, length 95mm;

[0036] Type II negative electrode welding section 2: welding strip diameter 0.3mm, length 90mm;

[0037] Type II transition section 3: welding strip thickness 0.15mm welding strip length 15mm transition angle 170°;

[0038] After the above two specifications of multi-main-grid half-cut battery cells 3 are assembled in series using two kinds of welding strips in the above manner, the phenomenon of hidden cracks on the edges is significantly reduced. According to actual measurements, the probability of hidden cracks on both sides before mixed assembly is about 0.8%, while the probability of hidden cracks on both sides after mixed assembly drops sharply to 0.15%, which significantly improves the stability of product quality and reduces the number of customer complaints about hidden cracks. The reason for the above-mentioned effect is that more photovoltaic welding tapes are used in the splicing process of multi-main-grid half-cut cells, and the positive welding section and the negative welding section of the photovoltaic welding tape will clamp the half-cut cell 3 during the series connection. In this way, the simultaneous action of multiple photovoltaic welding tapes will cause the half-cut cell 3 to be subjected to greater stress as a whole, and the stress will extend to both sides, resulting in the edge of the half-cut cell 3 having a tendency to warp in an undirected manner. In this way, when the edge position is subjected to a greater external force in the opposite direction, there is a probability of hidden cracks. Therefore, it is necessary to appropriately reduce the contact pressure of the welding tape on the edge position of the cell to relieve the internal stress of the cell. The technical solution reduces the size of the side welding tape, on the one hand, which reduces the contact area of the welding position, and on the other hand, the strength per unit length becomes lower after the welding tape becomes thinner, which can further reduce the contact pressure on the cell. In this way, the antagonistic contact pressure between the cell and the cell after welding is significantly reduced, which relieves the internal stress on both sides of the cell, thereby significantly reducing the probability of hidden cracks on both sides.

[0039] The above are only embodiments of the present utility model, and do not thus limit the patent scope of the present utility model. Any equivalent structural or equivalent process transformations made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. A hybrid assembly structure of a solar cell, wherein the solar cell is formed by continuously connecting and splicing multiple half-cut cell pieces in series through photovoltaic solder tapes. The number of the photovoltaic solder tapes is the same as the number of main grids on the half-cut cell pieces. When adjacent two half-cut cell pieces are spliced, multiple photovoltaic solder tapes are arranged in parallel according to the number of main grids on the half-cut cell pieces for series connection. Each photovoltaic solder tape includes a positive welding section, a negative welding section, and a transition section. The negative welding section is welded on the negative main grid of the front half-cut cell piece, the positive welding section is welded on the positive main grid of the rear half-cut cell piece, and the transition section connects the positive welding section and the negative welding section. It is characterized in that, The multiple parallel photovoltaic solder tapes are divided into two categories, namely type I solder tapes and type II solder tapes. The type I solder tapes are distributed on the outermost sides of both sides of the half-cut cell, and the type II solder tapes are distributed in the middle of the half-cut cell. The size of the type I solder tape is smaller than that of the type II solder tape.

2. The hybrid assembly structure of a solar cell according to claim 1, characterized in that, The sizes of the positive welding section and the negative welding section of the type I solder tape are respectively 60% - 85% of the sizes of the positive welding section and the negative welding section of the type II solder tape.

3. The hybrid assembly structure of a solar cell according to claim 1, characterized in that, The transition section is a flat structure.

4. The hybrid assembly structure of a solar cell according to claim 3, characterized in that, The transition angle between the transition section and the positive welding section and the negative welding section is 160 - 170°.

5. The hybrid assembly structure of a solar cell according to claim 1, wherein, The length of the transition section is 8 - 15 mm.

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