Photovoltaic module and preparation process

Abstract

The present invention discloses a photovoltaic module and a preparation process. The photovoltaic module comprises: a glass cover plate, an encapsulation film, a battery string with overlapping areas between battery cells, a reflective component, a reflective bus bar and a transparent back plate, wherein the encapsulation film is used to encapsulate the battery string between the glass cover plate and the transparent back plate; the reflective component is arranged on the main surface of the transparent back plate in contact with the encapsulation film; the reflective component corresponds to the gap between two adjacent battery strings or to the gap between the battery string and the edge of the transparent back plate; the reflective bus bar is arranged at the end of the battery string, and is used to connect multiple battery strings in series and / or in parallel, and reflect light for the battery string. The photovoltaic module can increase the power generation.

Description

Technical Field

[0001] The invention relates to a photovoltaic component and a preparation process. Background Art

[0002] Nowadays, bifacial photovoltaic modules that can improve power generation revenue are increasingly favored by the market. Existing bifacial photovoltaic modules mainly coat or fill white reflective materials between the cell strings and between the cells, so that the white reflective materials reflect the light entering between the cell strings or between the cells to the interface where the glass cover plate contacts the air, and then the interface refracts the reflected light to the cell surface to increase the photoelectric conversion efficiency of the front side of the bifacial photovoltaic module.

[0003] In the existing double-sided photovoltaic modules, the white reflective material between the cells will block the back of the cells, resulting in lower power generation on the back of the photovoltaic module. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a photovoltaic module and a preparation process, which can effectively increase the power and power generation on the back side of the cell in the double-sided photovoltaic module, thereby increasing the power and power generation of the double-sided photovoltaic module.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a photovoltaic module, comprising: a glass cover plate, a packaging film, a battery string with overlapping areas between battery cells, a reflective component, a reflective bus bar and a transparent back plate, wherein:

[0007] The packaging film is used to package the battery string between the glass cover plate and the light-transmitting back plate;

[0008] The reflective component is arranged on the main surface of the light-transmitting back plate in contact with the packaging film;

[0009] The reflective component corresponds to the gap between two adjacent battery strings or to the gap between the battery string and the edge of the light-transmitting backplane;

[0010] The reflective busbar is arranged at the end of the battery string, and is used to connect a plurality of battery strings (13) in series and / or in parallel, and to reflect light for the battery string (13).

[0011] In a second aspect, the present invention provides a process for preparing a photovoltaic module, comprising:

[0012] Step (a), arranging a reflective component on the light-transmitting backplane, wherein the position of the reflective component on the light-transmitting backplane corresponds to the gap between two adjacent battery strings or to the gap between the battery string and the edge of the light-transmitting backplane;

[0013] Step (b), laying a packaging film on the glass cover plate, and laying the battery strings and reflective busbars with overlapping areas on the packaging film;

[0014] Step (c), further laying a packaging film on the battery string and the reflective bus bar, and covering the transparent back plate on the packaging film, and laminating.

[0015] The technical solution of the first aspect of the above invention has the following advantages or beneficial effects: the photovoltaic module provided by the embodiment of the present invention can avoid light transmission between the cells due to the overlapping areas between the cells in the cell string. Compared with the conventional bifacial module, the lateral reflective components are eliminated, eliminating the lateral light blocking of the cells on the back of the module, thereby improving the power generation of the cells on the back. However, there is light transmission at the edge of the cell at the end of the string, which reduces the power generation of the end cell. At this time, a reflective bus bar for connecting multiple cell strings in series and / or in parallel is provided at the end of the cell string. The reflective bus bar can fill the gap between the end of the cell string and the edge of the back panel, and has the ability to reflect light from the non-cell area of ​​the end and the back panel edge to the cell surface, thereby increasing the light intensity on the front and back of the end cell. While improving the power generation of the front side of the photovoltaic module, the light receiving area on the back side of the cell is increased compared with the prior art, which can effectively improve the power generation of the back side of the photovoltaic module, thereby effectively improving the power generation of the photovoltaic module.

[0016] In addition, the above-mentioned reflective components and reflective bus bars can make the electric power of each battery cell increase more evenly, thereby ensuring the improvement of the overall electric power of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A is a schematic diagram of a back sheet of a double-sided photovoltaic module in the prior art;

[0018] Figure 1B is a schematic diagram of a prior art bifacial photovoltaic module;

[0019] Figure 2 is a cross-sectional schematic diagram of a photovoltaic module according to an embodiment of the present invention;

[0020] Figure 3 is a cross-sectional schematic diagram of a photovoltaic module according to another embodiment of the present invention;

[0021] Figure 4 is a cross-sectional schematic diagram of a photovoltaic module according to another embodiment of the present invention;

[0022] Figure 5 is a schematic diagram of a light-transmitting backplane according to an embodiment of the present invention;

[0023] Fig. 6A is a schematic diagram of a cross section of a reflective bus bar according to an embodiment of the present invention;

[0024] Figure 6B is a plan view of a reflective bus bar according to an embodiment of the present invention;

[0025] Figure 6C is a plan view of a reflective bus bar according to an embodiment of the present invention;

[0026] Figure 7 is a schematic diagram of a cross section of a reflective bus bar according to another embodiment of the present invention;

[0027] Figure 8 is a schematic diagram of a cross section of a reflective bus bar according to another embodiment of the present invention;

[0028] Fig. 9 is a schematic diagram of the relationship between the reflective bus bar and the back reflective layer according to an embodiment of the present invention;

[0029] Fig.10 is a schematic diagram of the relationship between the reflective bus bar and the front reflective layer according to an embodiment of the present invention;

[0030] Fig.11 is a schematic diagram of a cross section of a reflective bus bar according to another embodiment of the present invention;

[0031] Fig.12 is a cross-sectional view of yet another reflective bus bar according to an embodiment of the present invention;

[0032] Fig.13 is a top view of a bus bar according to an embodiment of the present invention;

[0033] Fig.14 is a diagram showing the relative position relationship between a reflective bus bar and a reflective component with different structures according to an embodiment of the present invention;

[0034] Fig.15 is a schematic diagram of the main process of the preparation process of a photovoltaic module according to an embodiment of the present invention;

[0035] Fig.16 Schematic diagram of the reflective path of the double-sided reflective bus bar according to an embodiment of the present invention.

[0036] The reference numerals are as follows:

[0037] 11 Glass cover 12 Packaging film

[0038] 13 battery strings 131 battery cells

[0039] 14 Reflective parts

[0040] 141 Middle area of ​​reflective component

[0041] 142 Edge area of ​​reflective components

[0042] 15 Reflective busbars

[0043] 151 groove 152 first reflective film

[0044] 153 bus bar 154 second reflective film

[0045] 155 Intermediate confluence area

[0046] 156 End catchment area

[0047] 16 Translucent back panel

[0048] 161 Main surface of the light-transmitting backplane in contact with the encapsulation film

[0049] 162 first edge of the light-transmitting backplane

[0050] 163 Second edge of the light-transmitting backplane

[0051] 14' reflective material

[0052] 16' Glass back panel in the prior art

[0053] 17 Reflective film on the back

[0054] 18. Front reflective film

[0055] 19 Junction Box DETAILED DESCRIPTION

[0056] At present, the battery strings in the bifacial photovoltaic modules are generally connected by welding strips, and there are gaps between the battery cells. In order to improve the electric power of the front side of the bifacial photovoltaic module in the prior art, Figure 1A As shown, reflective material 14' is disposed on the glass back plate 16' corresponding to the gaps between the cells, the gaps between the cell strings, and the gaps between the ends of the cell strings and the edges of the glass back plate 16'. Figure 1A The glass back sheet is applied to the bifacial photovoltaic module to obtain the following Figure 1B The schematic diagram of the back side of the bifacial photovoltaic module is shown in FIG. Figure 1BIt can be seen that on the glass back plate 16', corresponding to the gap between the cells 131 and the gap between the end of the cell string and the edge of the back plate, the width of the reflective material 14' is greater than the gap between the cells 131 and the gap between the end of the cell string and the edge of the back plate, which can block the edge of the back of the cell 131, reduce the light receiving area of ​​the back of the cell 131, and cause the back power generation of the photovoltaic module to be low. As a result, the overall power generation of the photovoltaic module is low.

[0057] In the following description and the appended claims, the front side of any structure in a photovoltaic module refers to the main surface of the structure facing the sunlight during the use of the photovoltaic module, and the back side of any structure in a photovoltaic module refers to the main surface of the structure facing away from the sunlight during the use of the photovoltaic module. For example, the front side of a cell refers to the main surface of the cell facing the sunlight, and the back side of the cell refers to the main surface of the cell facing away from the sunlight.

[0058] The main component of the white reflective material can be any one or more of titanium dioxide, silicon dioxide, zirconium oxide, aluminum oxide, zinc oxide, etc. The white reflective material forms a reflective coating on the glass. The white reflective material can form a reflective coating on the glass by a method well known to those skilled in the art, such as a dry coating method or a wet coating method.

[0059] The photovoltaic module provided in the embodiment of the present invention is a double-sided photovoltaic module, that is, the glass cover plate 11 and the light-transmitting back plate 16 are both light-transmitting, wherein the light entering from the glass cover plate 11 reaches the front of the battery cells in the battery string 13, and the light entering from the light-transmitting back plate 16 reaches the back of the battery cells in the battery string 13. Figures 2 to 4 The schematic diagram of the partial cross-sectional structure of the photovoltaic module shown in FIG. Figure 2 and Figure 3 It is a partial cross-sectional view of the photovoltaic module along the extension direction of the battery string, where: Figure 2 The battery string 13 shown is a shingled battery string. Figure 3 The battery string 13 shown is a stack-welded battery string. Figure 4 It is a cross-sectional view perpendicular to the direction in which the battery string extends. Figures 2 to 4 It can be seen that the photovoltaic module provided by the embodiment of the present invention includes: a glass cover plate 11, a packaging film 12, a battery string 13 with overlapping areas between battery cells (overlapping areas formed in a shingled or overlapping manner, such as a part of one battery cell overlapped on a part of another battery cell), a reflective component 14, a reflective bus bar 15 and a transparent back plate 16, wherein the packaging film 12 is used to package the battery string 13 between the glass cover plate 11 and the transparent back plate 16. Figure 4 and Figure 5As shown, the reflective component 14 is disposed on the main surface 161 of the transparent back plate 16 that contacts the packaging film 12; the reflective component 14 corresponds to the gap between two adjacent battery strings 13 or the gap between the battery string 13 and the edge of the transparent back plate 16. Figure 2 , Figure 3 as well as Fig.14 As shown, the reflective busbar 15 is disposed at the end of the battery string 13, and is used to connect multiple battery strings 13 in series and / or in parallel, and reflect light for the battery string 13. Figure 5 , the main surface 161 of the transparent backplane 16 in contact with the packaging film 12 is substantially the front surface of the transparent backplane 16. It can be understood that due to Figure 2 and Figure 3 The cross-sectional view along the extension direction of the battery string is shown, and the reflective member 14 corresponding to the gap between two adjacent battery strings 13 or the gap between the battery string 13 and the edge of the light-transmitting back plate 16 is not shown. Figure 4 What is shown is a cross-sectional view in a direction perpendicular to the extending direction of the battery string, and the reflective bus bar 15 located at the end of the battery string 13 is not shown.

[0060] Among them, the above-mentioned transparent backplane 16 can be a transparent polymer backplane or a glass backplane. In a preferred embodiment, the transparent backplane 16 is a glass backplane. The busbar refers to a conductive metal strip that collects the current of the battery string and is connected to the junction box of the photovoltaic module. The reflective performance of the busbars commonly used in the art is poor. The reflective busbar described in the present invention refers to a busbar with a reflective coating or a treatment for enhanced light reflection. For example, one way is to coat a composition comprising a binder, an inorganic film-forming material and a solvent on the busbar by a dry coating method or a wet coating method, and solidify it. Among them, the inorganic film-forming material may include any one or more inorganic film-forming materials of titanium dioxide, silicon dioxide, zirconium oxide, aluminum oxide, zinc oxide, etc., and the binder may include an organic substance or a colloid generated from an organic salt, an inorganic salt, or a metal organic compound as a raw material. While ensuring the adhesion between the reflective material and the transparent polymer backplane or the glass backplane, the reflective material has relatively good reflective properties.

[0061] It is worth noting that the battery string 13 can be as follows Figure 2 The shingled battery string shown can also be Figure 3 By selecting the shingled cell string or the stacked cell string, there will be no gaps between the cells, so there is no need to set reflective components or reflective materials between the cells, so as to reduce the shading area of ​​the back of the cell by the reflective components or reflective materials, and increase the light receiving area of ​​the back of the cell.

[0062] like Figure 5As shown, on the main surface 161 of the light-transmitting backplane 16, a plurality of reflective components 14 are distributed in parallel along the extension direction of the battery string 13. The positions of the plurality of reflective components 14 on the light-transmitting backplane 16 correspond to the gaps between the battery strings and the gaps between the battery strings and the first edge 162 of the light-transmitting backplane 16. It is worth noting that the first edge 162 of the light-transmitting backplane 16 refers to the edge parallel to the extension direction of the battery string 13. By distributing a plurality of reflective components 14 in parallel on the main surface of the light-transmitting backplane 16, it is possible to prevent sunlight from penetrating the gaps between the battery strings 14 and the gaps between the battery strings 14 and the first edge 162 of the light-transmitting backplane 16, and at the same time, it is possible to reflect sunlight on the front side of the photovoltaic module to the front side of the battery cell, and reflect sunlight on the back side of the photovoltaic module to the back side of the battery cell, so as to effectively increase the power generation of the photovoltaic module. Among them, as Figure 4 The relative positional relationship between the reflective component 14 and the cell string 13 shown in the cross-sectional view of the photovoltaic module shown in the figure shows that the middle area 141 of the reflective component 14 overlaps with the gap, and the edge area 142 of the reflective component 14 overlaps with the edge of the adjacent cell string 13. The edge of the cell string 13 refers to the edge along the extension direction of the cell string.

[0063] The reflective component 14 can be formed by coating a composition including a binder, an inorganic film-forming material and a solvent on a back plate by dry coating or wet coating, and then solidifying. The inorganic film-forming material can include any one or more inorganic film-forming materials such as titanium dioxide, silicon dioxide, zirconium oxide, aluminum oxide, zinc oxide, etc., and the binder can include organic matter or a colloid generated from organic salts, inorganic salts, and metal organic compounds as raw materials. While ensuring the adhesion between the reflective material and the light-transmitting polymer back plate or glass back plate, the reflective material has better reflective properties.

[0064] Among them, Figure 2 or Figure 3 As shown, the reflective busbar 15 is arranged at the end of the battery string 13 to block Figure 5 The sunlight shown passes through the gap between the end of the battery string 13 and the second edge 163 of the back panel 16. In addition, when the ends of the two battery strings 13 are arranged opposite to each other, the reflective bus bar 15 can also block the sunlight from passing through the gap between the ends of the two oppositely arranged battery strings 13. At the same time, the reflective bus bar 15 can reflect the light to the battery cells in the battery string to further increase the power generation of the photovoltaic module.

[0065] Among them, the reflective busbar can have various structures, such as Fig. 6A , Figure 6B , Figure 6C , Figure 7 , Figure 8 as well as Fig.11 As shown:

[0066] In the embodiment of the present invention, Fig. 6A As shown in the cross-sectional view of the reflective bus bar, the front surface of the reflective bus bar 15 is arranged with a plurality of grooves 151. Figure 6B and Figure 6C In the plan view of the reflective busbar shown, the groove 151 can extend along the length direction of the reflective busbar 15, and the groove 151 can also be arranged in a direction that forms a certain angle with the front width direction of the reflective busbar 15. That is, the angle between the extension direction of the groove 151 and the front width direction of the reflective busbar 15 is not 0. In addition, the cross-section of the groove 151 can be an inverted triangle or an approximately inverted triangle or an inverted trapezoidal structure, wherein the vertex embedded in the reflective busbar 15 in the approximately inverted triangle can be an arc-shaped, tooth-shaped, or other structure. The design of the groove on the front side can effectively control the direction in which the reflective busbar reflects sunlight, so that the light reflected by the reflective busbar can be reflected as much as possible on the front side of the solar cell.

[0067] In the embodiment of the present invention, Figure 7 As shown in the cross-sectional view of the reflective bus bar, the back of the reflective bus bar 15 is provided with a plurality of grooves 151. It is worth noting that the arrangement of the grooves 151 on the back of the reflective bus bar 15 can also be as follows: Figure 6B and Figure 6C As shown, the groove 151 may extend along the length direction of the reflective bus bar 15, and the groove 151 may also be arranged in a direction that forms a certain angle with the width direction of the back side of the reflective bus bar 15. That is, the angle between the extension direction of the groove 151 and the width direction of the back side of the reflective bus bar 15 is not 0. In addition, the cross-section of the groove 151 provided on the back side of the reflective bus bar 15 may also be an inverted triangle or an approximately inverted triangle or an inverted trapezoidal structure, wherein the vertex embedded in the reflective bus bar 15 in the approximately inverted triangle may be an arc-shaped, tooth-shaped, or other structure. The design of the groove on the back side can effectively control the direction of the sunlight transmitted by the reflective bus bar reflecting the light-transmitting back plate, so that the light reflected by the reflective bus bar can be reflected as much as possible on the back side of the solar cell.

[0068] In a preferred embodiment, Figure 8 As shown in the cross-sectional view of the reflective bus bar, the front and back sides of the reflective bus bar 15 are arranged with a plurality of grooves 151. It is worth noting that the arrangement of the grooves 151 on the front and back sides of the reflective bus bar 15 can also be as follows: Figure 6B and Figure 6CAs shown, the groove 151 may extend along the length direction of the reflective bus bar 15, and the groove 151 may also be arranged in a direction that forms a certain angle with the width direction of the reflective bus bar 15. Among them, the arrangement directions of the grooves 151 on the front and back sides of the reflective bus bar 15 do not affect each other. For example, the groove 151 on the front side of the reflective bus bar 15 may extend along the length direction of the reflective bus bar 15, and the groove 151 on the back side of the reflective bus bar 15 may extend along the length direction of the reflective bus bar 15. For another example, the groove 151 on the front side of the reflective bus bar 15 may extend along the length direction of the reflective bus bar 15, and the groove 151 on the back side of the reflective bus bar 15 may be arranged in a direction that forms a certain angle with the width direction of the back side of the reflective bus bar 15. For example, the grooves 151 on the front side of the reflective bus bar 15 are arranged in a direction that is at a certain angle to the width direction of the reflective bus bar 15, and the grooves 151 on the back side of the reflective bus bar 15 can extend along the length direction of the reflective bus bar 15, etc. That is, the angle between the extension direction of the grooves 151 on the front and back sides of the reflective bus bar 15 and the width direction of the back side of the reflective bus bar 15 is not 0. In addition, the cross-section of the grooves 151 set on the front and back sides of the reflective bus bar 15 can also be an inverted triangle or an approximately inverted triangle or an inverted trapezoidal structure, wherein the vertex embedded in the reflective bus bar 15 in the approximately inverted triangle can be an arc-shaped, tooth-shaped, or other structure. It can be understood that the cross-sectional structure of the grooves 151 set on the front and back sides of the reflective bus bar 15 can be different or the same, and is not limited here.

[0069] In the embodiment of the present invention, Fig. 6A The structure of the reflective bus bar 15 shown in the figure, that is, the front side of the reflective bus bar 15 is arranged with a plurality of grooves, and the back side of the reflective bus bar 15 is a planar structure, the photovoltaic module may further include: a back reflective film 17 arranged on the back side of the reflective bus bar 15 to effectively increase the power generation on the back side of the photovoltaic module, wherein the relationship between the reflective bus bar 15 and the back reflective film 17 can be as shown in Fig. 9 shown.

[0070] In the embodiment of the present invention, Figure 7 The structure of the reflective bus bar 15 shown in the figure, that is, the back of the reflective bus bar 15 is arranged with a plurality of grooves, and the front of the reflective bus bar 15 is a planar structure, the photovoltaic module may further include: a front reflective film 18 arranged on the front of the reflective bus bar 15 to effectively increase the power generation of the front of the photovoltaic module, wherein the relationship between the reflective bus bar 15 and the back reflective film 17 (front reflective film 18) can be as follows Fig.10 shown.

[0071] Furthermore, the reflective bus bar 15 includes a front reflective film 18 and / or a back reflective film 17, which can not only increase the power generation of the photovoltaic module, but also can be sucked by an automatic sucking machine when preparing the photovoltaic module. The front reflective film 18 and / or the back reflective film 17 can effectively reduce the probability of sucking failure due to air leakage during the automatic machine sucking the bus bar. It is worth noting that although the surface of the front reflective film 18 and / or the back reflective film 17 is flat, the internal structure of the front reflective film 18 and / or the back reflective film 17 includes a twill structure / reflective pattern that can improve the reflectivity.

[0072] For the groove 151 with an inverted triangle or triangular structure in cross section, the angle between the two side surfaces of the groove 151 is greater than or equal to 90 degrees. For the groove 151 with an inverted trapezoidal structure, the angle between the two side surfaces of the groove 151 and the concave portion of the groove 151 is greater than 90 degrees. This effectively increases the sunlight reflected by the reflective busbar onto the cell, thereby further increasing the power generation of the photovoltaic module.

[0073] In the embodiment of the present invention, Fig.11 As shown, the reflective bus bar 15 may include: a first reflective film 152 and a bus bar 153, wherein the first reflective layer 152 is bonded to the front surface of the bus bar 153. The upper surface of the first reflective layer 152 may be a planar structure.

[0074] In the embodiment of the present invention, Fig.12 As shown, the reflective busbar 15 includes, in addition to the first reflective film 152 and the busbar 153, a second reflective film 154, wherein the second reflective film 154 is bonded to the back of the busbar 153. The presence of the first reflective film 152 and / or the second reflective film 154, in addition to increasing the power generation of the photovoltaic module, can also be used to suck the reflective busbar 15 by an automatic suction machine when preparing the photovoltaic module, and the first reflective film 152 and / or the second reflective film 154 can effectively reduce the probability of suction failure due to air leakage during the automatic machine suction process of the busbar. It is worth noting that although the surface of the first reflective film 152 and / or the second reflective film 154 is flat, the internal structure of the first reflective film 152 and / or the second reflective film 154 includes a twill structure / reflective pattern that can improve the reflectivity.

[0075] In the embodiment of the present invention, Fig.13As shown in the top view of the busbar, the reflective busbar 13 may include: an intermediate busbar area 155 connected to the battery string and an end busbar area 156 for connecting to an external junction box, wherein the width of the end busbar area 156 is smaller than the width of the intermediate busbar area 155 to meet the requirements of the busbar connecting to the junction box. The end busbar area 156 is relatively wide, which can make the edge of the busbar closer to the battery cell, so that the reflected light can more easily reach the surface of the battery cell and cover a larger area of ​​the battery cell. In the embodiment of the present invention, the width of the end busbar area 156 is smaller than the width of the wiring hole of the junction box 19. It is worth noting that Fig.13 The cross-sectional structure of the busbar shown can be compared with the above Fig. 6A , Figure 6B , Figure 6C and Figures 7 to 12 Any of the cross-sectional views are consistent and will not be described in detail here.

[0076] In addition, it is worth pointing out that Fig.13 In addition to the busbar width variation shown in FIG. 6A, Figure 6B , Figure 6C and Figures 7 to 12 The width of any one of the reflective bus bars can also remain constant.

[0077] In the embodiment of the present invention, Fig.14 The relative position relationship diagram between the reflective busbars and reflective components of different structures shown in the figure, Fig.13 The reflective busbar shown can be applied to a photovoltaic module with a junction box 19 disposed in the middle. In addition, the position and number of reflective busbars of different structures can be adjusted according to actual needs.

[0078] In the embodiment of the present invention, the first type of reflective busbar with a constant width can be arranged at the edge area of ​​the transparent back plate 16, and the second type of reflective busbar with a constant width can be arranged in the middle area of ​​the transparent back plate 16, wherein the width of the second type of reflective busbar is smaller than the width of the wiring hole of the external wiring box. Fig.14 In the structure shown, the middle busbar can also be replaced by a busbar of uniform width, wherein the width of the middle busbar is smaller than the width of the wiring hole of the wiring box 19. The width of the first type of reflective busbar is generally not smaller than the width of the second type of reflective busbar.

[0079] The technical solutions provided by the above-mentioned embodiments can avoid light transmission between the cells due to the overlapping areas between the cells in the cell string. Compared with conventional bifacial modules, the lateral reflective components are eliminated, eliminating the lateral light blocking of the cells on the back of the module, thereby improving the power generation of the cells on the back. However, there is light transmission at the edge of the cells at the end of the string, which reduces the power generation of the end cells. At this time, a reflective bus bar for connecting multiple cell strings in series and / or in parallel is provided at the end of the cell string. The reflective bus bar can fill the gap between the end of the cell string and the edge of the back panel, and has the ability to reflect light from the non-cell area of ​​the end and the edge of the back panel to the cell surface, thereby increasing the light intensity on the front and back of the end cell. While improving the power generation of the front side of the photovoltaic module, the light receiving area on the back side of the cell is increased compared with the prior art, which can effectively improve the power generation of the back side of the photovoltaic module, thereby effectively improving the power generation of the photovoltaic module.

[0080] In addition, the above-mentioned reflective components and reflective bus bars can make the electric power of each battery cell increase more evenly, thereby ensuring the improvement of the overall electric power of the photovoltaic module.

[0081] like Fig.15 The flowchart of a process for preparing a photovoltaic module provided by an embodiment of the present invention is shown. The process for preparing the photovoltaic module may include the following steps:

[0082] Step S1501: a reflective component is provided on the transparent backplane, wherein the position of the reflective component on the transparent backplane corresponds to the gap between two adjacent battery strings or to the gap between the battery string and the edge of the transparent backplane;

[0083] Wherein, the reflective component can be provided by coating a composition comprising a binder, an inorganic film-forming material and a solvent on the backplane, wherein the width of the coated reflective component is not less than the gap between two adjacent battery strings or not less than the gap between the battery string and the edge of the transparent backplane. The reflective component is distributed along the gap between the battery strings and the gap between the battery string and the edge of the transparent backplane. Wherein, the edge of the transparent backplane refers to the edge in the backplane parallel to the extension direction of the battery string.

[0084] Step S1502: Laying a packaging film on the glass cover plate and laying the battery strings and reflective bus bars in the overlapping area on the packaging film;

[0085] In this step, Fig.14 In the structure shown in FIG. 1 , a reflective bus bar 15 with a constant width can be laid in the edge area of ​​the glass cover plate, and a reflective bus bar 15 with a constant width can be laid in the middle area of ​​the glass cover plate. Fig.13 The reflective bus bar 15 shown has an end bus bar region 156 connected to an external terminal box, wherein the width of the end bus bar region 156 is smaller than the middle region 155 of the reflective bus bar 15 .

[0086] In addition, for Fig.14 In the structure shown, the middle bus bar can also be replaced by a bus bar with a uniform width, wherein the width of the middle bus bar is smaller than the width of the wiring hole of the wiring box 19 .

[0087] Step S1503: further laying a packaging film on the battery string and the reflective bus bar, and covering the transparent back plate on the packaging film, and laminating.

[0088] The following is a description of a specific embodiment.

[0089] like Figure 5 , the double glass back sheet or transparent back sheet of the stacked or shingled bifacial photovoltaic module, the reflective component 14 is only coated between the battery strings, and there is no coating between the battery cells. Figure 5 The backplane shown is used in Fig.14 In the photovoltaic module shown, there is no reflective material to block the light between the cells. Taking 182 half-cells as an example, each half-cell can increase the power generation area by 172mmx (5 to 10)mm, thereby increasing the power generation on the back of the module.

[0090] However, for the cells at the beginning and end of each string, the reflective material between the cells is removed, so that the light at the end of the string (the beginning or end of the string) can directly penetrate the backplane glass or transparent backplane, resulting in light loss. This will affect the power of the cells at the end of the string, causing current mismatch with other cells in the string, and thus affecting the entire string and even the power generation of the entire module. Similarly, the cells at the end of the back string will also have the same problem without the obstruction of reflective material. Therefore, if Fig.14 As shown, further at the end of the battery string is provided Figures 8-10 as well as Fig.12 The double-sided reflective bus bar shown in FIG. The reflective path of the double-sided reflective bus bar is as follows: Fig.16 As shown. That is, when light is irradiated on the surface of the double-sided reflective busbar, the light can be refracted to the surface of the battery through the glass-air interface. By setting a reflective busbar at the end of the battery string or replacing the existing ordinary busbar with the reflective busbar, light compensation can be implemented on the front and back of the battery at the end of the battery string, thereby avoiding the current mismatch caused by insufficient reflected light absorbed by the battery cells at the end of the battery string, and ensuring the power generation of the battery string, battery string group and photovoltaic module.

[0091] It is worth noting that, in addition to the above-mentioned reflective components and reflective busbars in the photovoltaic module, only reflective busbars can be set in the photovoltaic module. That is, another photovoltaic module provided by the embodiment of the present invention may include: a glass cover plate 11, a packaging film 12, a battery string 13 with overlapping areas between battery cells, a reflective busbar 15 and a transparent back plate 16, wherein the packaging film 12 is used to encapsulate the battery string 13 between the glass cover plate 11 and the transparent back plate 16; the reflective busbar 15 is set at the end of the battery string 13, and is used to connect multiple battery strings 13 in series and / or in parallel, and reflect light for the battery string 13.

[0092] Accordingly, the preparation process of the photovoltaic module provided with only the reflective busbars comprises:

[0093] Step (a'), laying a packaging film 12 on the glass cover plate 11, and laying the battery strings 13 and the reflective busbars 15 with overlapping areas on the packaging film 12;

[0094] Step (b'): laying a packaging film 12 on the battery string 13 and the reflective bus bar 15, and covering the packaging film 12 with a transparent back sheet 16 for lamination.

[0095] The embodiments of the present invention provide the following technical solutions and combinations of the technical solutions.

[0096] Technical solution 1, a photovoltaic module, comprising: a glass cover plate 11, a packaging film 12, a battery string 13 with overlapping areas between battery cells, a reflective component 14, a reflective bus bar 15 and a transparent back plate 16, wherein:

[0097] The packaging film 12 is used to package the battery string 13 between the glass cover plate 11 and the light-transmitting back plate 16;

[0098] The reflective component 14 is disposed on a main surface 161 of the light-transmitting back plate 16 that contacts the packaging film 12;

[0099] The reflective component 14 corresponds to the gap between two adjacent battery strings 13 or to the gap between the battery string 13 and the edge of the light-transmitting backplane 16;

[0100] The reflective bus bar 15 is disposed at the end of the battery string 13 , and is used to connect a plurality of battery strings 13 in series and / or in parallel, and reflect light for the battery string 13 .

[0101] Technical solution 2: The photovoltaic module according to technical solution 1,

[0102] A plurality of the reflective components 14 are distributed in parallel on the main surface 161 of the light-transmitting back plate 16 along the extending direction of the battery string 13 .

[0103] Technical solution 3: The photovoltaic module according to technical solution 1 or 2,

[0104] The middle area 141 of the reflective component 14 overlaps with the gap;

[0105] The edge region 142 of the reflective component 14 overlaps with the edge of the adjacent battery string 13 .

[0106] Technical solution 4: The photovoltaic module according to technical solution 1,

[0107] The reflective component 14 includes: a binder, an inorganic film-forming material and a solvent, wherein the inorganic film-forming material includes any one or more of titanium dioxide, silicon dioxide, zirconium oxide, aluminum oxide, zinc oxide and the like.

[0108] Technical solution 5: The photovoltaic module according to technical solution 1,

[0109] A plurality of grooves 151 are arranged on the front and / or back of the reflective bus bar 15 . Preferably, the cross section of the groove 151 is an inverted triangle or approximately an inverted triangle or an inverted trapezoidal structure.

[0110] Technical solution 6: The photovoltaic module according to technical solution 5,

[0111] A plurality of grooves are arranged on the front side of the reflective bus bar 15, and the back side of the reflective bus bar 15 is a flat structure.

[0112] The photovoltaic module further comprises: a back reflective layer 17 disposed on the back of the reflective bus bar 15;

[0113] or,

[0114] A plurality of grooves are arranged on the back of the reflective bus bar 15, and the front of the reflective bus bar 15 is a planar structure.

[0115] The photovoltaic module further includes a front reflective layer 18 disposed on the front side of the reflective bus bar 15 .

[0116] Technical Solution 7: According to the photovoltaic module described in Technical Solution 1, the reflective bus bar 15 includes: a first reflective layer 152 and a bus bar 153, wherein:

[0117] The first light reflecting layer 152 is bonded to the front surface of the bus bar 153 .

[0118] Technical Solution 8: According to the photovoltaic module described in Technical Solution 7, the reflective bus bar 15 further includes: a second reflective layer 154, wherein:

[0119] The second light reflecting layer 154 is bonded to the back surface of the bus bar 153 .

[0120] Technical Solution 9: According to the photovoltaic assembly described in any one of Technical Solutions 1, 5 and 7, the reflective bus bar 15 includes: an intermediate bus area 155 connected to the battery string and an end bus area 156 for connecting to an external junction box, wherein:

[0121] The width of the middle merging area 155 is greater than the width of the end merging area 156 .

[0122] Technical solution 10. The photovoltaic module according to technical solution 9,

[0123] The width of the end confluence area 156 is smaller than the width of the wiring hole of the wiring box.

[0124] Technical solution 11. The photovoltaic module according to technical solution 9,

[0125] The reflective busbar 15 with a constant width is arranged at the edge area of ​​the transparent back plate 16 , and the reflective busbar 15 with an end busbar area 156 connected to the external junction box is arranged in the middle area of ​​the transparent back plate 16 .

[0126] Technical solution 12. A photovoltaic module according to any one of technical solutions 1 to 8,

[0127] The first type of reflective busbar with a constant width is arranged at the edge area of ​​the transparent back plate 16, and the second type of reflective busbar with a constant width is arranged in the middle area of ​​the transparent back plate 16, wherein the width of the second type of reflective busbar is smaller than the width of the wiring hole of the external wiring box.

[0128] Technical solution 13. The photovoltaic module according to technical solution 1,

[0129] The battery string 13 is a stacked-weld battery string or a shingled battery string.

[0130] Technical Solution 14: A process for preparing a photovoltaic module, comprising:

[0131] Step (a), disposing a reflective component 14 on the transparent back plate 16, wherein the position of the reflective component 14 on the transparent back plate 16 corresponds to the gap between two adjacent battery strings 13 or to the gap between the battery string 13 and the edge of the transparent back plate 16;

[0132] Step (b), laying a packaging film 12 on the glass cover plate 11, and laying the battery strings 13 and the reflective busbars 15 with overlapping areas on the packaging film 12;

[0133] Step (c): further laying a packaging film 12 on the battery string 13 and the reflective bus bar 15, and covering the packaging film 12 with a transparent back sheet 16 for lamination.

[0134] Technical Solution 15. According to the preparation process described in Technical Solution 14, step (b) comprises:

[0135] A reflective bus bar 15 with a constant width is laid in the edge area of ​​the glass cover plate 11, and a reflective bus bar 15 with an end bus area 156 connected to an external junction box is laid in the middle area of ​​the transparent back plate 16, wherein the width of the end bus area 156 is smaller than the middle area of ​​the reflective bus bar 15.

[0136] Technical solution 16, a photovoltaic module, comprising: a glass cover plate 11, a packaging film 12, a battery string 13 with overlapping areas between battery cells, a reflective bus bar 15 and a transparent back plate 16, wherein:

[0137] The packaging film 12 is used to package the battery string 13 between the glass cover plate 11 and the light-transmitting back plate 16;

[0138] The reflective bus bar 15 is disposed at the end of the battery string 13 , and is used to connect a plurality of battery strings 13 in series and / or in parallel, and reflect light for the battery string 13 .

[0139] The preparation process of the photovoltaic module described in Technical Solution 17 and Technical Solution 16 comprises:

[0140] Step (a'), laying a packaging film 12 on the glass cover plate 11, and laying the battery strings 13 and the reflective busbars 15 with overlapping areas on the packaging film 12;

[0141] Step (b'): laying a packaging film 12 on the battery string 13 and the reflective bus bar 15, and covering the packaging film 12 with a transparent back sheet 16 for lamination.

[0142] The introduction provided in the above steps is only used to help understand the method, structure and core idea of ​​the present invention. For ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also belong to the scope of protection of the claims of the present invention.

Claims

1. A photovoltaic module, It is characterized in that include: A glass cover plate (11), a packaging film (12), a battery string (13) with overlapping areas between battery cells, a reflective component (14), a reflective bus bar (15), and a light-transmitting back plate (16), wherein: The packaging adhesive film (12) is used to package the battery string (13) between the glass cover plate (11) and the light-transmitting back plate (16); The reflective component (14) is arranged on a main surface (161) of the light-transmitting back plate (16) that is in contact with the packaging adhesive film (12); The reflective component (14) corresponds to the gap between two adjacent battery strings (13) or corresponds to the gap between the battery string (13) and the edge of the light-transmitting backplane (16); The reflective busbar (15) is arranged at the end of the battery string (13), and is used to connect a plurality of battery strings (13) in series and / or in parallel, and to reflect light for the battery string (13); The reflective bus bar (15) comprises: a middle bus area (155) connected to the battery string, and end bus areas (156) located on both sides of the middle bus area (155) for connecting to an external junction box, wherein: The width of the middle merging area (155) is greater than the width of the end merging area (156); A reflective bus bar (15) with a constant width is arranged at an edge region of the light-transmitting back plate (16), and a reflective bus bar (15) having an end bus area (156) connected to an external junction box is arranged at a middle region of the light-transmitting back plate (16).

2. The photovoltaic module according to claim 1, It is characterized in that A plurality of the reflective components (14) are distributed in parallel on the main surface (161) of the light-transmitting back plate (16) along the extension direction of the battery string (13).

3. The photovoltaic module according to claim 1 or 2, It is characterized in that The middle area (141) of the reflective component (14) overlaps with the gap; The edge region (142) of the reflective component (14) overlaps with the edge of the adjacent battery string (13).

4. The photovoltaic module according to claim 1, It is characterized in that The reflective component (14) comprises: a binder, an inorganic film-forming material and a solvent, wherein the inorganic film-forming material comprises any one or more of titanium dioxide, silicon dioxide, zirconium oxide, aluminum oxide and zinc oxide.

5. The photovoltaic module according to claim 1, It is characterized in that A plurality of grooves (151) are arranged on the front side and / or the back side of the reflective busbar (15).

6. The photovoltaic module according to claim 1, It is characterized in that The reflective busbar (15) comprises: a first reflective layer (152) and a busbar (153), wherein: The first light reflecting layer (152) is bonded to the front surface of the bus bar (153).

7. The photovoltaic module according to claim 5, It is characterized in that A plurality of grooves are arranged on the front side of the reflective bus bar (15), and the back side of the reflective bus bar (15) is a planar structure. The photovoltaic module further comprises: a back reflective layer (17) arranged on the back side of the reflective bus bar (15); or, A plurality of grooves are arranged on the back side of the reflective bus bar (15), and the front side of the reflective bus bar (15) is a planar structure. The photovoltaic assembly further comprises: a front reflective layer (18) arranged on the front side of the reflective busbar (15).

8. The photovoltaic module according to claim 6, It is characterized in that The reflective busbar (15) further comprises: a second reflective layer (154), wherein: The second light reflecting layer (154) is bonded to the back side of the bus bar (153).

9. The photovoltaic module according to claim 1, It is characterized in that The width of the end busbar area (156) is smaller than the width of the wiring hole of the wiring box.

10. The photovoltaic module according to any one of claims 1 to 6, It is characterized in that A first type of reflective busbar with a constant width is arranged at an edge region of the light-transmitting back plate (16), and a second type of reflective busbar with a constant width is arranged at a middle region of the light-transmitting back plate (16), wherein the width of the second type of reflective busbar is smaller than the width of the wiring hole of the external wiring box.

11. The photovoltaic module according to claim 1, It is characterized in that The battery string (13) is a stacked-weld battery string or a shingled battery string.

12. The photovoltaic module according to claim 5, It is characterized in that The cross section of the groove (151) is an inverted triangle or approximately an inverted triangle or an inverted trapezoidal structure.

13. A process for preparing a photovoltaic module. It is characterized in that include: Step (a), arranging a reflective component (14) on the light-transmitting backplane (16), wherein the position of the reflective component (14) on the light-transmitting backplane (16) corresponds to the gap between two adjacent battery strings (13) or to the gap between the battery string (13) and the edge of the light-transmitting backplane (16); Step (b), laying a packaging film (12) on the glass cover plate (11), and laying the battery strings (13) and the reflective busbars (15) in the overlapping area on the packaging film (12); Step (c), further laying a packaging film (12) on the battery string (13) and the reflective busbar (15), and covering the light-transmitting backplane (16) on the packaging film (12), and laminating; The reflective bus bar (15) comprises: a middle bus area (155) connected to the battery string, and end bus areas (156) located on both sides of the middle bus area (155) for connecting to an external junction box, wherein: The width of the middle merging area (155) is greater than the width of the end merging area (156); A reflective bus bar (15) with a constant width is arranged at an edge region of the light-transmitting back plate (16), and a reflective bus bar (15) having an end bus area (156) connected to an external junction box is arranged at a middle region of the light-transmitting back plate (16).

14. The preparation process according to claim 13, It is characterized in that Step (b) comprises: A reflective bus bar (15) having a constant width is laid in the edge region of the glass cover plate (11), and a reflective bus bar (15) having an end bus bar region (156) connected to an external junction box is laid in the middle region of the light-transmitting back plate (16), wherein the width of the end bus bar (156) is smaller than the middle region of the reflective bus bar (15).

15. A photovoltaic module, It is characterized in that include: A glass cover plate (11), a packaging film (12), a battery string (13) with overlapping areas between battery cells, a reflective bus bar (15), and a light-transmitting back plate (16), wherein: The packaging adhesive film (12) is used to package the battery string (13) between the glass cover plate (11) and the light-transmitting back plate (16); The reflective busbar (15) is arranged at the end of the battery string (13), and is used to connect a plurality of battery strings (13) in series and / or in parallel, and to reflect light for the battery string (13); The reflective bus bar (15) comprises: a middle bus area (155) connected to the battery string, and end bus areas (156) located on both sides of the middle bus area (155) for connecting to an external junction box, wherein: The width of the middle merging area (155) is greater than the width of the end merging area (156); A reflective bus bar (15) with a constant width is arranged at an edge region of the light-transmitting back plate (16), and a reflective bus bar (15) having an end bus area (156) connected to an external junction box is arranged at a middle region of the light-transmitting back plate (16).

16. The process for preparing a photovoltaic module according to claim 15, include: Step (a'), laying a packaging film (12) on the glass cover plate (11), and laying the battery strings (13) and the reflective busbars (15) in the overlapping area on the packaging film (12); Step (b'), further laying a packaging film (12) on the battery string (13) and the reflective busbar (15), and covering the light-transmitting backplane (16) on the packaging film (12), and laminating; The reflective bus bar (15) comprises: a middle bus area (155) connected to the battery string, and end bus areas (156) located on both sides of the middle bus area (155) for connecting to an external junction box, wherein: The width of the middle merging area (155) is greater than the width of the end merging area (156); A reflective bus bar (15) with a constant width is arranged at an edge region of the light-transmitting back plate (16), and a reflective bus bar (15) having an end bus area (156) connected to an external junction box is arranged at a middle region of the light-transmitting back plate (16).

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