Back contact photovoltaic module and photovoltaic system

Abstract

The utility model provides a back contact photovoltaic assembly and a photovoltaic system, and relates to the field of photovoltaic technology. The back contact photovoltaic module comprises a plurality of battery strings; the cell string is formed by electrically connecting a plurality of back contact solar cells; in one battery string, a piece spacing is formed between two adjacent back contact solar battery pieces along the extension direction of the battery string; in all the sheet spacing of the back contact photovoltaic module, the sheet spacing greater than or equal to 60% is less than or equal to 0.6 mm; and the number of the welding strips for connecting the adjacent back contact solar cells is an even number. According to the back contact photovoltaic module, the string length of the battery string can be reduced to a great extent, the size of the back contact photovoltaic module in the extending direction of the battery string is reduced, the sizes of the conductive interconnection piece, the adhesive film, the cover plate, the back plate and the like are reduced, the cost of the back contact photovoltaic module is further reduced, the space utilization rate is improved, and the yield of the module is high and the cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a back-contact photovoltaic component and a photovoltaic system. Background Art

[0002] The electrodes of back-contact solar cells are all on the back of the cell, and there is no electrode blocking the front, so it has a higher short-circuit current and photoelectric conversion efficiency. Since the output voltage of a single back-contact solar cell is relatively low, a certain number of back-contact solar cells are usually packaged into back-contact photovoltaic modules to broaden their application scenarios.

[0003] However, the existing back-contact photovoltaic modules have a high cost, and the back-contact solar cells in the back-contact photovoltaic modules have a low space utilization rate for the modules, which affects their widespread application. Utility Model Content

[0004] The utility model provides a back-contact photovoltaic module and a photovoltaic system, aiming to solve the problems of high cost and low space utilization of the existing back-contact photovoltaic modules.

[0005] In a first aspect, the present invention provides a back-contact photovoltaic module, comprising:

[0006] A plurality of battery strings; the battery strings are formed by electrically connecting a plurality of back-contact solar cells;

[0007] In one of the battery strings, along the extension direction of the battery string, there is a sheet spacing between two adjacent back-contact solar cells;

[0008] Among all the inter-sheet spacings of the back-contact photovoltaic module, greater than or equal to 60% of the inter-sheet spacings are less than or equal to 0.6 mm; and the number of welding strips connecting adjacent back-contact solar cells is an even number.

[0009] In the embodiment of the utility model, in the back-contact photovoltaic module, among all the inter-sheet spacings, greater than or equal to 60% of the inter-sheet spacings are less than or equal to 0.6mm. In the back-contact photovoltaic module, the vast majority of inter-sheet spacings are less than or equal to 0.6mm. Compared with the inter-sheet spacing in the related art of at least 0.8mm-0.9mm, the inter-sheet spacing of the present application is smaller, which means that the blank area of ​​the inter-sheet gap in the back-contact photovoltaic module is reduced, thereby greatly reducing the string length of the battery string, reducing the size of the back-contact photovoltaic module along the extension direction of the battery string, reducing the size of the conductive interconnect, adhesive film, cover plate, back plate, etc., thereby reducing the cost of the back-contact photovoltaic module. At the same time, due to the reduction in inter-sheet spacing, at the same

[0010] More cells can be arranged in the component area, which improves the space utilization of the component and thus increases the power of the component. In addition, the number of welding strips connecting adjacent back-contact solar cells is an even number. In the battery string, the welding tension between the cells is more uniform, which can reduce the risk of parallel connection of cells; it can also reduce the problem of cell string distortion caused by uneven tension between cells, and thus reduce the risk of parallel connection; overall, it can improve the yield of back-contact photovoltaic components and reduce costs. In summary, the back-contact photovoltaic component of the utility model can reduce the size of consumables such as back plates, cover plates, and adhesive films, improve the space utilization of components, and reduce the risks of parallel connection, cell string distortion, and parallel connection, so as to achieve the purpose of increasing component power and reducing costs.

[0011] Optionally, in the back-contact photovoltaic module, the spacing between all the sheets is less than or equal to 0.6 mm.

[0012] Optionally, in the back-contact photovoltaic module, the spacing between all the sheets is less than or equal to 0.3 mm and greater than or equal to 0.01 mm.

[0013] Optionally, in the back contact photovoltaic module, the variance of all the inter-sheet spacings is less than or equal to 0.1 mm. 2 .

[0014] Optionally, the back-contact photovoltaic module further comprises: a rear encapsulation film and at least one adhesive tape; the rear encapsulation film and the adhesive tape are both located on the back side of the back-contact solar cell, and the adhesive tape comprises: a portion located between the rear encapsulation film and the back-contact solar cell;

[0015] Along the extending direction of the cell string, the adhesive tape covers at least the end regions on the back sides of two adjacent back-contact solar cells and the gap between two adjacent back-contact solar cells.

[0016] Optionally, along the extension direction of the battery string, a covering distance of one of the adhesive tapes on the back side of one of the back-contact solar cells is 2±1 mm.

[0017] Optionally, in the back contact photovoltaic module, along the extension direction of the battery string, the variance of the coverage distance of each tape on the back side of the back contact solar cell is less than or equal to 1 mm. 2 .

[0018] Optionally, the adhesive tape comprises: an adhesive tape body, and a solid adhesive layer located on the adhesive tape body, wherein the adhesive tape body is located between the solid adhesive layer and the rear packaging adhesive film;

[0019] And / or, the adhesive tape is embedded in the surface of the rear encapsulation film close to the back contact solar cell sheet.

[0020] Optionally, the thickness of the solid glue layer is 45±1 μm;

[0021] And / or, the material of the adhesive tape body is selected from: polyethylene terephthalate, the solid adhesive

[0022] The material of the layer is selected from: acrylic.

[0023] Optionally, each of the back contact solar cells has a width of 182.2±0.5 mm and a length of 96 mm-98 mm or 105 mm-108 mm; and / or,

[0024] The back contact photovoltaic module comprises: a total of 12 battery strings distributed in two columns and six rows; and / or,

[0025] The length of the back-contact photovoltaic module is 2382±1 mm and the width is 1134±1 mm; the length of the cover plate and the back plate of the back-contact photovoltaic module is 2376±1 mm and the width is 1128±1 mm; and / or,

[0026] The string spacing between adjacent battery strings is 1.3±1mm; and / or,

[0027] The number of the soldering ribbons connecting the adjacent back-contact solar cells is 18 or 20; and / or the number of the soldering pads soldered to the soldering ribbons on each back-contact solar cell is an even number.

[0028] Optionally, the back-contact solar cell is placed on a carrying platform, and when the front side at least partially contacts the carrying platform and the back side faces away from the carrying platform, the warping degree of the back-contact solar cell is less than or equal to 3 mm.

[0029] The warpage of the back-contact solar cell is more consistent with the actual warpage, and the warpage is controlled more reasonably, which can better control the quality of the back-contact solar cell, thereby further improving the pass rate of the back-contact photovoltaic module.

[0030] The above-mentioned back-contact photovoltaic module and photovoltaic system have the same or similar beneficial effects, and in order to avoid repetition, they will not be described here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic structural diagram of a back-contact photovoltaic module in an embodiment of the utility model is shown;

[0033] Figure 2 A partial structural schematic diagram of a battery string in an embodiment of the utility model is shown;

[0034] Figure 3 A schematic diagram of the warpage of a back-contact solar cell in an embodiment of the utility model is shown.

[0035] Description of the accompanying drawings:

[0036] 1-cell string, 2-back contact solar cell sheet, 21-back side of back contact solar cell, 22-front side of back contact solar cell, 3-middle bus bar, 4-tape. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0038] The inventors found that the main reason for the high cost and low space utilization of the existing back-contact photovoltaic modules is that the electrodes of the back-contact solar cells are all on the back of the cells, and their warpage is usually large. If the warpage is too large, the risk of paralleling is relatively large in the process of forming the back-contact photovoltaic modules. In order to reduce paralleling, the inter-sheet spacing is usually enlarged. For example, the inter-sheet spacing in the related art is at least about 0.8mm-0.9mm. A large inter-sheet spacing will increase the string length, and then increase the size of the back-contact photovoltaic module along the extension direction of the battery string, resulting in a large size of the conductive interconnection parts, adhesive films, cover plates, back plates, frames, etc., or a large inter-sheet spacing will compress the area ratio of the battery cells in the module, making the cost of the back-contact photovoltaic module high. At the same time, since the space occupied by the inter-sheet spacing does not contribute to the power generation efficiency, etc., the effective power generation part of the back-contact photovoltaic module set in the same space is small, which reduces the space utilization.

[0039] The core concept of the utility model is to reduce the inter-sheet spacing as much as possible without paralleling the sheets, that is, to reduce the blank area of ​​the inter-sheet spacing in the back-contact photovoltaic module, thereby reducing the string length, reducing the size of the back-contact photovoltaic module along the extension direction of the battery string, reducing the size of the conductive interconnection parts, adhesive film, cover plate, back plate, frame, etc., thereby reducing the cost of the back-contact photovoltaic module. On the other hand, due to the reduction in inter-sheet spacing, more back-contact solar cells can be arranged in the same module area, improving the space utilization of the module, and thus increasing the power of the module.

[0040] Figure 1 A schematic structural diagram of a back-contact photovoltaic module in an embodiment of the utility model is shown. Figure 2 The partial structural diagram of a battery string in the embodiment of the utility model is shown. Figure 1 and Figure 2 The back-contact photovoltaic module includes: a plurality of battery strings 1, which can be formed by electrically connecting a plurality of back-contact solar cells 2, where the electrical connection can be in series and / or in parallel, and there is no specific limitation on this. During normal operation of the back-contact photovoltaic module, the surface of the back-contact solar cell 2 that mainly receives light is the front side, and the back side and the front side are relatively distributed.

[0041] The extension direction of the battery string 1 refers to the direction parallel to the direction of its length. Figure 1 , Figure 2 In the figure, the direction indicated by L1 is the extension direction of the battery string 1. In a battery string 1, along the extension direction L1 of the battery string 1, there is a sheet spacing d1 between two adjacent back-contact solar cells 2. In the case where a battery string 1 is formed by n back-contact solar cells 2 connected in series linearly, the number of sheet spacings d1 in the battery string 1 is n-1. For example, Figure 1 , Figure 2 In the case where each battery string 1 is formed by 12 back-contact solar cells 2 connected in series linearly in sequence, the number of cell spacings d1 in the battery string 1 is 11.

[0042] All inter-cell spacings d1 of a back-contact photovoltaic module refer to the sum of all inter-cell spacings d1 in each cell string 1 of the back-contact photovoltaic module. For example, Figure 1 In the back-contact photovoltaic module shown, there are a total of 12 cell strings 1, and each cell string 1 has 11 inter-cell pitches. Thus, in the back-contact photovoltaic module, there are a total of 12×11=132 inter-cell pitches.

[0043] In a back-contact photovoltaic module, among all the inter-chip spacing d1, greater than or equal to 60% of the inter-chip spacing d1 is less than or equal to 0.6 mm. In this back-contact photovoltaic module, the vast majority of the inter-chip spacing d1 is less than or equal to 0.6 mm, which can greatly reduce the string length of the battery string 1, reduce the size of the back-contact photovoltaic module along the extension direction of the battery string 1, and reduce the size of the conductive interconnection parts, adhesive film, cover plate, back plate, frame, etc., thereby reducing the cost of the back-contact photovoltaic module. At the same time, due to the reduction in the inter-chip spacing d1, more back-contact photovoltaic modules can be arranged in the same module area, thereby improving space utilization.

[0044] For example, refer to Figure 1 In the back contact photovoltaic module shown, 60% of the inter-sheet spacing d1 is: 132×60%=80, refer to Figure 1 In the back-contact photovoltaic module shown, there are greater than or equal to 80 inter-sheet spacings d1, all less than or equal to 0.6 mm.

[0045] It should be noted that, in a back-contact photovoltaic module, on the basis of being greater than or equal to 60%, the specific number of inter-sheet spacings d1 that are less than or equal to 0.6 mm is not specifically limited. For example, in the back-contact photovoltaic module, among all inter-sheet spacings d1, 60% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or 64% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or 70% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or 76% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or 82% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or 91% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or 96% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or 100% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm.

[0046] It should be noted that in a back-contact photovoltaic module, on the basis that the inter-sheet spacing d1 is less than or equal to 0.6 mm, there is no specific limitation on the specific amount. For example, in the back-contact photovoltaic module, among all inter-sheet spacings d1, greater than or equal to 60% of the inter-sheet spacings d1 may be less than or equal to 0.6 mm, or less than or equal to 0.5 mm, or less than or equal to 0.4 mm, or less than or equal to 0.36 mm, or less than or equal to 0.3 mm, or less than or equal to 0.2 mm, or less than or equal to 0.16 mm. In addition, the inter-sheet spacings in the module do not need to be equal.

[0047] It should be noted that the materials of the conductive interconnection member, adhesive film, cover plate, and back plate are not specifically limited. For example, the cover plate may be ultra-white embossed tempered glass with a thickness of about 3.2 mm, and the conductive interconnection member may be a tin-coated copper strip.

[0048] The number of welding strips connecting adjacent back-contact solar cells 2 is an even number. In the battery string 1, the welding tension between the battery cells 2 and the battery cells 2 is more uniform, which can reduce the risk of parallel connection of the battery cells 2; it can also reduce the problem of distortion of the battery string 1 caused by uneven tension between the cells, thereby reducing the risk of parallel connection; overall, it can improve the yield of the back-contact photovoltaic module and reduce costs. It should be noted that the specific size of the even number is not limited here. There is no specific limitation on the materials of the welding strips and pads.

[0049] Optionally, in a back-contact photovoltaic module, all inter-cell spacing d1 is less than or equal to 0.6 mm, and the length of the battery string 1 is reduced more significantly, thereby further reducing the size of the back-contact photovoltaic module along the extension direction of the battery string 1, and further reducing the size of the conductive interconnects, adhesive films, cover plates, back plates, frames, etc., thereby further reducing the cost of the back-contact photovoltaic module. At the same time, since the inter-cell spacing d1 is further reduced, more back-contact battery cells can be arranged in the same module area, further improving the space utilization of the module, thereby increasing the power of the module.

[0050] For example, refer to Figure 1 In the back-contact photovoltaic module shown, the spacing d1 between the 132 panels is less than or equal to 0.6 mm.

[0051] Optionally, in the back-contact photovoltaic module, each or all of the inter-sheet spacing d1 is less than or equal to 0.3 mm and greater than or equal to 0.01 mm, and the length of the battery string 1 is reduced to a greater extent, further reducing the size of the back-contact photovoltaic module along the extension direction of the battery string 1, and further reducing the size of the conductive interconnection parts, adhesive film, cover plate, back plate, frame, etc., thereby further reducing the back-contact photovoltaic

[0052] At the same time, as the cell spacing d1 is further reduced, more back-contact cells can be arranged in the same module area, further improving space utilization and thus increasing module power.

[0053] For example, refer to Figure 1 In the back-contact photovoltaic module shown, the spacing d1 between the 132 panels is less than or equal to 0.3 mm and greater than or equal to 0.01 mm.

[0054] It should be noted that in a back-contact photovoltaic module, on the basis that all inter-sheet spacings d1 are less than or equal to 0.3 mm, there is no specific limitation on the specific value. For example, in the back-contact photovoltaic module, all inter-sheet spacings d1 are less than or equal to 0.3 mm, or less than or equal to 0.28 mm, or less than or equal to 0.26 mm, or less than or equal to 0.22 mm, or less than or equal to 0.2 mm, or less than or equal to 0.18 mm, or less than or equal to 0.13 mm, or less than or equal to 0.1 mm, or less than or equal to 0.08 mm, or less than or equal to 0.06 mm, or less than or equal to 0.03 mm, or less than or equal to 0.02 mm, or less than or equal to 0.01 mm. Of course, the values ​​of the inter-sheet spacings in the module do not need to be equal.

[0055] Optionally, in the back contact photovoltaic module, the variance of all the inter-sheet spacings d1 is less than or equal to 0.1 mm. 2 That is, in the back-contact photovoltaic module, the size of the inter-sheet spacing d1 is relatively uniform, the variance of all inter-sheet spacing d1 is small, and the effect of reducing the string length of the battery string 1 is more obvious. Compared with the situation in the related art where the inter-sheet spacing is inconsistent, it is necessary to determine the inter-sheet spacing at the corresponding position according to the position of the back-contact solar cell 2. In the present utility model, in the process of placing the back-contact solar cell 2, the inter-sheet spacing d1 does not need to consider the position of the back-contact solar cell 2, the operation is simple, the efficiency is high, and the formed back-contact photovoltaic module is more beautiful.

[0056] For example, in a back-contact photovoltaic module, the variance of the spacing d1 between all panels can be: 0.1 mm 2 , or 0.09mm 2 , or 0.08mm 2 , or 0.07mm 2 , or 0.05mm 2 , or 0.04mm 2 , or 0.032mm 2 , or 0.01mm 2 .

[0057] Optional, see Figure 2 The back-contact photovoltaic module may further include: a rear encapsulation film (not shown) and at least one tape 4, the rear encapsulation film and the tape 4 are both located on the back of the back-contact solar cell 2, and the tape 4 includes: a portion located between the rear encapsulation film and the back-contact solar cell 2. The rear encapsulation film here may be an EVA film (polyethylene-polyvinyl acetate copolymer), a POE film (ethylene-octene copolymer), etc., and the specific material, size, etc. are not limited.

[0058] Reference Figure 2 , along the extension direction L1 of the battery string 1, the tape 4 covers at least the end area on the back side of two adjacent back-contact solar cells 2, and the gap between two adjacent back-contact solar cells 2. The main function of the tape 4 here is to fix the aforementioned smaller inter-sheet spacing d1. When combined with the aforementioned smaller inter-sheet spacing d1, the string length of the battery string 1 can be reduced as much as possible. It should be noted that the end areas here are adjacent to the gap in the extension direction of the battery string 1. The tape 4 is located on the back side of the back-contact solar cell 2 and will not block light, etc.

[0059] It should be noted that, since the warpage of the back-contact solar cell 2 is strictly controlled, there are fewer parallel cells in the cell string, and the tape 4 here can also play a role in reducing parallel cells, further reducing the risk of parallel cells. For the back-contact photovoltaic module, the number of tapes 4 can be equal to the total number of cell spacing d1, or the number of tapes 4 can be less than the total number of cell spacing d1, and there is no specific limitation on this.

[0060] Optionally, along the extension direction L1 of the battery string 1, a tape 4 covers the back side of a back-contact solar cell 2 by a distance of 2±1 mm. This covering distance is relatively suitable, which can not only effectively fix the aforementioned smaller inter-cell spacing d1 and effectively reduce the string length of the battery string 1, but also prevent the size from being too large, thus avoiding waste and increasing costs.

[0061] For example, along the extension direction L1 of the battery string 1, the coverage distance of one adhesive tape 4 on the back side of one back-contact solar cell 2 may be 1 mm, or 1.2 mm, or 1.5 mm, or 1.95 mm, or 2 mm, or 2.1 mm, or 2.4 mm, or 3 mm. For another example, if the inter-sheet spacing d1 is 0.4 mm, and the coverage distance of one adhesive tape 4 on the back side of one back-contact solar cell 2 is 2 mm, then along the extension direction L1 of the battery string 1, the size of one adhesive tape 4 = 2 + 0.4 + 2 = 4.4 mm.

[0062] Optionally, in the back-contact photovoltaic module, along the extension direction L1 of the cell string 1, the variance of the coverage distance of all the tapes 4 on the back side of each back-contact solar cell 2 is less than or equal to 1 mm. 2 The covering distance of the tape 4 on the back side of each back-contact solar cell 2 is set relatively uniformly, the aesthetic performance is good, and the process parameters for setting the tape 4 at each position are basically consistent, and the efficiency is high.

[0063] For example, in a back-contact photovoltaic module, along the extension direction L1 of the cell string 1, the variance of the coverage distance of all the tapes 4 on the back side of each back-contact solar cell 2 may be 1 mm. 2, or 0.98mm 2 , or 0.95mm 2 , or 0.91mm 2 , or 0.87mm 2 , or 0.8mm 2 , or 0.7mm 2 , or 0.5mm 2 , or 0.2mm 2 , or 0.1mm 2 .

[0064] Optionally, the tape 4 includes: a tape body and a solid adhesive layer on the tape body, wherein the tape body is located between the solid adhesive layer and the rear encapsulation film. The tape 4 is embedded in the surface of the rear encapsulation film close to the back contact solar cell 2. Specifically, during the lamination process, the adhesive layer in the tape 4 may melt or vaporize, and the tape body will basically not melt or vaporize. The melted or vaporized adhesive layer will still firmly bond the tape body and the back contact solar cell 2 together. After lamination, when the temperature drops, the melted or vaporized adhesive layer will solidify or crystallize again to form a solid adhesive layer. The tape 4 is embedded in the surface of the rear encapsulation film close to the back contact solar cell 2, that is, the tape 4 is embedded in the front of the rear encapsulation film. Although the structural state of the tape 4 may change to a certain extent during the lamination process, it will basically have no adverse effect on the lamination.

[0065] Optionally, the thickness of the solid glue layer in the tape 4 is 45±1μm (micrometer). On the one hand, the amount of the glue layer is not too much to avoid glue overflow. On the other hand, the glue layer is not too little, and the bonding ability is better. For example, in a back-contact photovoltaic module, the thickness of the solid glue layer in the tape 4 can be 44μm, or 44.3μm, or 44.5μm, or 44.8μm, or 44.9μm, or 45μm, or 45.1μm, or 45.3μm, or 45.9μm, or 46μm. It should be noted that the direction of the thickness mentioned in the full text is parallel to the stacking direction of the tape body and the glue layer in the back-contact photovoltaic module.

[0066] Optionally, the material of the tape body can be selected from: polyethylene terephthalate (PET), and the material of the solid adhesive layer can be selected from: acrylate. The tape 4 made of the above material is easy to obtain, has low cost, and has basically no adverse effects on the back contact solar cell 2 and the lamination process.

[0067] Optionally, in the present invention, each back contact solar cell 2 has a width of 182.2±0.5 mm and a length of 96 mm-98 mm or 105 mm-108 mm. For example, the width of the back contact solar cell 2 may be 181.7 mm, or 181.73 mm, or 181.85 mm, or 181.75 mm, or 181.93 mm, or 181.99 mm, or 182.1 mm, or 182.12 mm, or 182.25 mm, or 182.3 mm, or 182.42 mm, or 182.55 mm, or 182.6 mm, or 182.7 mm. The length of the back contact solar cell 2 can be 96 mm, or 96.5 mm, or 96.65 mm, or 96.75 mm, or 96.93 mm, or 97 mm, or 97.3 mm, or 97.5 mm, or 97.72 mm, or 98 mm. For another example, the length of the back contact solar cell 2 can be 105 mm, or 105.5 mm, or 105.65 mm, or 106 mm, or 106.5 mm, or 106.75 mm, or 107 mm, or 107.5 mm, or 107.72 mm, or 108 mm. Figure 1 The back contact photovoltaic module includes: two columns and six rows of arrays.

[0068] 12 cells in string 1. For example, refer to Figure 1 and Figure 2 , each cell string 1 is formed by 12 back-contact solar cells 2 connected in series. The length d2 of the back-contact photovoltaic module is 2382±1 mm, and the width d3 is 1134±1 mm. For example, the length d2 of the back-contact photovoltaic module can be 2381 mm, or 2381.43 mm, or 2381.5 mm, or 2381.75 mm, or 2381.93 mm, or 2382 mm, or 2382.4 mm, or 2382.72 mm, or 2383 mm. The width d3 of the back-contact photovoltaic module can be 1133 mm, or 1133.23 mm, or 1133.5 mm, or 1133.75 mm, or 1134 mm, or 1134.3 mm, or 1134.4 mm, or 1134.62 mm, or 1135 mm. Since the present application reduces the inter-sheet spacing d1, the length d2 of the back-contact photovoltaic module of this version is reduced, thereby reducing the size of the packaging film, cover plate, back plate, frame, conductive interconnects, etc., thereby significantly reducing costs.

[0069] Optionally, the length of the cover plate and the back plate of the back contact photovoltaic module is 2376±1mm, and the width is 1128±1mm. Since the present application reduces the inter-sheet spacing d1, the area of ​​the solar cell can be further increased under the module size or cover plate size. For example, the length of the cover plate and the back plate of the back contact photovoltaic module is 2375mm, or 2375.1mm, or 2375.24mm, or 2375.4mm, or 2375.5mm, or 2375.6mm, or 2375.7mm, or 2375.88mm, or 2375.91mm, or 2376mm, or 2376.1mm, or 2376.31mm, or 2376.45mm, or 2376.5mm, or 2376.79mm, or 2377mm. For example, the width of the cover plate and the back plate of the back contact photovoltaic module is 1127mm, or 1127.1mm, or 1127.24mm, or 1127.4mm, or 1127.5mm, or 1127.6mm, or 1127.7mm, or 1127.88mm, or 1127.91mm, or 1128mm, or 1128.1mm, or 1128.31mm, or 1128.45mm, or 1128.5mm, or 1128.79mm, or 1129mm. It should be noted that in the back contact photovoltaic module, the sheet spacing d1 can be only about 0.2mm, such as (0.2±0.05)mm.

[0070] Optional, see Figure 1 In the back contact photovoltaic module, the string spacing d4 between adjacent battery strings 1 is 1.3±1mm. The string spacing d4 is set reasonably, which can not only ensure good electrical performance, but also avoid space waste. For example, the string spacing d4 can be 0.3mm, or 0.33mm, or 0.49mm, or 0.52mm, or 0.68mm, or 0.89mm, or 1mm, or 1.1mm, or 1.16mm, or 1.29mm, or 1.32mm, or 1.8mm, or 1.97mm,

[0071] Either 2.13mm or 2.3mm.

[0072] Optionally, along the direction where the row is located, the creepage distance d5 on both sides is greater than 13mm. The creepage distance d5 is set reasonably, which can not only ensure good electrical performance, but also avoid space waste. For example, along the direction where the row is located, the creepage distance d5 on both sides is 23±1mm. For another example, along the direction where the row is located, the creepage distance d5 on both sides can be 15mm, or 18mm, or 19.2mm, or 20mm, or 22.4mm, or 23mm, or 24mm.

[0073] Optionally, along the direction of the column, the creepage distance d6 on both sides is greater than or equal to 12 mm. The creepage distance d6 is set reasonably, which can not only ensure good electrical performance, but also avoid space waste. For example, along the direction of the column, the creepage distance d6 on both sides is 13±1 mm. For another example, along the direction of the column, the creepage distance d6 on both sides can be 12 mm, or 12.4 mm, or 12.9 mm, or 13 mm, or 13.4 mm, or 13.4 mm, or 13.7 mm, or 14 mm.

[0074] Optionally, the back contact photovoltaic module also includes: an intermediate bus bar 3 located between two columns of battery strings 1 and extending along the direction of the columns, which is used to converge the currents of the battery strings 1 on both sides, and the width of the intermediate bus bar 3 is 6±0.5mm. The width of the intermediate bus bar 3 is set reasonably, which can not only ensure good electrical performance, but also avoid space waste. The direction of the width of the intermediate bus bar 3 is parallel to the direction of the rows. For example, the width of the intermediate bus bar 3 can be 5.5mm, or 5.71mm, or 5.89mm, or 6mm, or 6.01mm, or 6.24mm, or 6.37mm, or 6.5mm.

[0075] Optionally, the back contact photovoltaic module also includes: a head bus bar located at the head of a column of battery strings 1, and a tail bus bar located at the tail of another column of battery strings, the head bus bar and the tail bus bar both extend along the direction of the column, and the width d7 of both is 3±1mm, and the head and the tail here are different from those between the two columns of battery strings 1. The width settings of the head bus bar and the tail bus bar are relatively reasonable, which can not only ensure good electrical performance, but also avoid space waste. The directions of the widths of the head bus bar and the tail bus bar are parallel to the direction of the rows. For example, the width d7 of both the head bus bar and the tail bus bar can be 2mm, or 2.31mm, or 2.89mm, or 3mm, or 3.01mm, or 3.24mm, or 3.87mm, or 4mm.

[0076] Optionally, along the direction of the aforementioned row, the distance between the middle bus bar 3 and the adjacent back contact solar cell 2 is 3±1 mm, and this size setting is relatively reasonable, which can not only ensure good electrical performance, but also avoid space waste. For example, along the direction of the aforementioned row, the distance between the middle bus bar 3 and the adjacent back contact solar cell 2 can be 2 mm, or 2.31 mm, or 2.89 mm, or 3 mm, or 3.01 mm, or 3.25 mm, or 3.87 mm, or 4 mm.

[0077] Optionally, along the direction of the aforementioned row, the distance d8 between the head bus bar and the adjacent back contact solar cell 2 is 3±1mm, and the distance d8 between the tail bus bar and the adjacent back contact solar cell 2 is 3±1mm. This size setting is relatively reasonable, which can not only ensure good electrical performance, but also avoid space waste. For example, the distance d8 between the head bus bar and the adjacent back contact solar cell 2, and the distance d8 between the tail bus bar and the adjacent back contact solar cell 2 can be 2mm, or 2.31mm, or 2.89mm, or 3mm, or 3.01mm, or 3.25mm, or 3.87mm, or 4mm.

[0078] The combination of the larger cell length, smaller cell spacing, the middle bus bar width that meets the needs of safe current transmission and its distance from the adjacent cell, the head bus bar width and its distance from the adjacent cell, and the tail bus bar and its distance from the adjacent cell can maximize the area of ​​cell laying in the back-contact photovoltaic module, reduce the gap, and at the same time reduce the risk of parallel connection to ensure safe current transmission; thereby, it can reduce costs and ensure the safety and reliability of the module while having a larger effective power generation area.

[0079] Optionally, the number of welding strips connecting adjacent back-contact solar cells 2 is 18 or 20. In the battery string, the welding tension between the battery cells is more uniform, which can reduce the risk of battery cell paralleling; it can also reduce the problem of battery string distortion caused by uneven tension between the cells, thereby reducing the risk of paralleling; overall, it can improve the yield of back-contact photovoltaic modules and reduce costs. And / or, the number of pads welded to the welding strip on each back-contact solar cell 2 is an even number. In the battery string, the welding tension between the electric pads is more uniform, which can reduce the risk of battery cell paralleling; it can also reduce the problem of battery string distortion caused by uneven tension between the cells, thereby reducing the risk of paralleling; overall, it can improve the yield of back-contact photovoltaic modules and reduce costs.

[0080] The back-contact solar cell 2 may be a half-cell obtained by dividing a back-contact solar cell half-cell with a size of about 182.2×(192-195) mm.

[0081] Figure 3 A schematic diagram of the warpage of a back-contact solar cell in an embodiment of the utility model is shown. Figure 3In the figure, the x-axis represents the support platform or the first surface of the support platform supporting the back contact solar cell. The y-axis represents the warping diagram of the back contact solar cell. For the back contact solar cell, the inventors found that since the electrodes of the back contact solar cell are all arranged on the back side 21, and the linear expansion coefficient of the functional layers such as the material of the electrode part and the insulating glue is greatly different from the linear expansion coefficient of the silicon substrate, the back contact solar cell is warped toward the back side 21. The shape of the formed back contact solar cell is always that the back side 21 is more contracted inward. In the process of placing the back contact solar cell, the front side 22 of the back contact solar cell is at least partially in contact with the support platform, and the back side 21 of the back contact solar cell is away from the support platform. In this case, several corners of the back contact solar cell are warped, and the middle part contacts the support platform. Since the several warped corners of the back contact solar cell basically do not contact the support platform, the warped corners are basically not subject to the friction force of the support platform, so the back contact solar cell can be fully stretched naturally, so that the stress of the electrodes, insulating glue, etc. in the back contact solar cell can be completely released, so in this way, the warping degree obtained is basically consistent with the actual warping degree of the back contact solar cell.

[0082] The back contact solar cell in the back contact photovoltaic module of the utility model, referring to Figure 3 , the back-contact solar cell is placed on a supporting platform, and when the front side 22 at least partially contacts the supporting platform and the back side 21 is away from the supporting platform, the warpage of the back-contact solar cell is less than or equal to 3 mm. The back-contact solar cell sheet 2 in any of the aforementioned back-contact photovoltaic modules is the back-contact solar cell here, or the sub-sheet obtained by slicing the back-contact solar cell here. According to Figure 3 The warpage display method shown, since the obtained warpage is basically consistent with the actual warpage, the back-contact solar cells with unqualified warpage will basically not be laminated together. During the lamination process, the back-contact solar cell cell 2 with a warpage less than or equal to 3mm will basically not be paralleled, thereby improving the qualified rate of photovoltaic modules.

[0083] For example, when the back-contact solar cell is placed on a carrying platform, with the front side 22 at least partially contacting the carrying platform and the back side 21 away from the carrying platform, the warping of the back-contact solar cell can be: 3 mm, or 2.9 mm, or 2.5 mm, or 2 mm, or 1.95 mm, or 1.6 mm, or 1.7 mm, or 1 mm.

[0084] The distance between at least two angular positions of the front side 22 of the back-contact solar cell and the first surface can reflect the degree of warping of the back-contact solar cell. The larger the distance, the greater the degree of warping. Therefore, the at least two angular positions of the front side 22 of the back-contact solar cell and the at least two distances between the first surface can accurately reflect the warping of the back-contact solar cell. The warping is more consistent with the actual warping of the back-contact solar cell, which can better control the quality of the back-contact solar cell, thereby further improving the qualified rate of photovoltaic modules. Moreover, for a back-contact solar cell, the measured angular positions can be fewer, which can reduce the measurement workload and improve the measurement efficiency of the warping.

[0085] It should be noted that, on the front side 22 of the aforementioned back-contact solar cell, at least two angular positions may be: any two angular positions, or any three angular positions, on the front side 22 of the back-contact solar cell... or all angular positions on the front side 22 of the back-contact solar cell. For example, if the front side 22 of the back-contact solar cell has four angular positions, then, here, it may be: measuring the positions between any two angular positions on the front side 22 of the back-contact solar cell and the first surface of the carrying platform to obtain two distances, or measuring the positions between any three angular positions and the first surface of the carrying platform to obtain three distances, or measuring the positions between four angular positions and the first surface of the carrying platform to obtain four distances.

[0086] It should be noted that the warpage of the back-contact solar cell may refer to the maximum value of at least two distances between at least two corners of the front side 22 of the back-contact solar cell and the first surface of the supporting platform. Alternatively, the warpage of the back-contact solar cell may refer to the average value of at least two distances between at least two corners of the front side 22 of the back-contact solar cell and the first surface of the supporting platform.

[0087] It should be noted that the corner of the back contact solar cell mentioned in the whole text refers to: the intersection position of two intersecting edges in the back contact solar cell, or the chamfered portion formed by the intersection position. More specifically, the corner of the back contact solar cell mentioned in the whole text refers to: the intersection position of two intersecting edges in the front side 22 of the back contact solar cell, or the chamfered portion formed by the intersection position.

[0088] For example, according to Figure 3 The warpage display method shown in the figure shows that the warpage of all back-contact solar cells is less than or equal to 3 mm. The half-cells obtained by slicing each back-contact solar cell form Figure 1The back-contact photovoltaic module shown. The length and width of each half-cell are: (182±0.5)×(96-98) mm. Among 500 such back-contact photovoltaic modules, the number of parallel-connected back-contact solar cells 2 is 0. Compared with the existing back-contact photovoltaic modules, the length of the 500 back-contact photovoltaic modules of the present application is reduced by about 10 mm.

[0089] The utility model also provides a photovoltaic system, which may include: a plurality of photovoltaic modules arranged in an array, in which the number of photovoltaic modules is not limited. The photovoltaic system may have the same or similar beneficial effects as any of the aforementioned photovoltaic modules, and the relevant parts of the two may refer to each other. The photovoltaic system may be set on a building roof, on the ground, etc., without specific limitation.

[0090] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0091] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A back contact photovoltaic module, characterized in that: include: A plurality of battery strings; the battery strings are formed by electrically connecting a plurality of back-contact solar cells; In one of the battery strings, along the extension direction of the battery string, there is a sheet spacing between two adjacent back-contact solar cells; Among all the inter-sheet spacings of the back-contact photovoltaic module, greater than or equal to 60% of the inter-sheet spacings are less than or equal to 0.6 mm; and the number of welding strips connecting adjacent back-contact solar cells is an even number.

2. The back contact photovoltaic module according to claim 1, characterized in that: In the back-contact photovoltaic module, all the inter-sheet spacings are less than or equal to 0.6 mm.

3. The back contact photovoltaic module according to claim 2, characterized in that: In the back-contact photovoltaic module, all the inter-sheet spacings are less than or equal to 0.3 mm and greater than or equal to 0.01 mm.

4. The back-contact photovoltaic module according to any one of claims 1 to 3, characterized in that: In the back contact photovoltaic module, the variance of all the inter-sheet spacings is less than or equal to 0.1 mm 2 .

5. The back-contact photovoltaic module according to any one of claims 1 to 3, characterized in that: Also includes: a rear encapsulation film and at least one adhesive tape; The rear encapsulation film and the adhesive tape are both located on the back side of the back contact solar cell sheet, and the adhesive tape includes: a portion located between the rear encapsulation film and the back contact solar cell sheet; Along the extending direction of the cell string, the adhesive tape covers at least the end regions on the back sides of two adjacent back-contact solar cells and the gap between two adjacent back-contact solar cells.

6. The back contact photovoltaic module according to claim 5, characterized in that: Along the extending direction of the cell string, the covering distance of one of the adhesive tapes on the back side of one of the back-contact solar cells is 2±1 mm.

7. The back contact photovoltaic module according to claim 6, characterized in that: In the back contact photovoltaic module, along the extension direction of the cell string, the variance of the coverage distance of each tape on the back side of the back contact solar cell is less than or equal to 1 mm. 2 .

8. The back contact photovoltaic module according to claim 6 or 7, characterized in that: The adhesive tape comprises: an adhesive tape body, and a solid adhesive layer located on the adhesive tape body, wherein the adhesive tape body is located between the solid adhesive layer and the rear packaging adhesive film; And / or, the adhesive tape is embedded in the surface of the rear encapsulation film close to the back contact solar cell sheet.

9. The back contact photovoltaic module according to claim 8, characterized in that: The thickness of the solid glue layer is 45±1μ5; and / or, The material of the adhesive tape body is selected from: polyethylene terephthalate, and the material of the solid adhesive layer is selected from: acrylate.

10. The back contact photovoltaic module according to any one of claims 1 to 3, 6 and 7, characterized in that: Each of the back contact solar cells has a width of 182.2±0.5 mm and a length of 96 mm-98 mm or 105 mm-108 mm; and / or, The back contact photovoltaic module comprises: a total of 12 battery strings distributed in two columns and six rows; and / or, The length of the back-contact photovoltaic module is 2382±1 mm and the width is 1134±1 mm; the length of the cover plate and the back plate of the back-contact photovoltaic module is 2376±1 mm and the width is 1128±1 mm; and / or, The string spacing between adjacent battery strings is 1.3±1mm; and / or, The number of the soldering ribbons connecting the adjacent back-contact solar cells is 18 or 20; and / or the number of the soldering pads soldered to the soldering ribbons on each back-contact solar cell is an even number.

11. The back contact photovoltaic module according to any one of claims 1 to 3, 6, 7 and 9, characterized in that: The back-contact solar cell is placed on a carrying platform, and when the front side at least partially contacts the carrying platform and the back side faces away from the carrying platform, the warping degree of the back-contact solar cell is less than or equal to 3 mm.

12. A photovoltaic system, characterized in that: include: A plurality of photovoltaic modules according to any one of claims 1 to 11 arranged in an array.

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