Photovoltaic module

Abstract

The present application relates to a photovoltaic module, which includes a backsheet and a battery string layer disposed on one side of the backsheet. The backsheet is provided with a plurality of lead-out holes arranged at intervals along a first direction. The battery string layer includes: multiple groups of battery string groups arranged at intervals along the first direction, each group of battery string groups includes two sub-battery string groups arranged at intervals along the first direction, and each sub-battery string group includes two battery strings arranged at intervals along a second direction; multiple intermediate busbars, each intermediate busbar is located between two battery strings in the same group in the second direction, one end of each intermediate busbar is correspondingly connected to a group of sub-battery string groups, and the other end of each intermediate busbar extends out of the lead-out hole. In the above photovoltaic module, since each intermediate busbar is only correspondingly connected to a group of sub-battery string groups, compared with connecting multiple groups of sub-battery string groups by continuously extending a single intermediate busbar, the length of at least part of the intermediate busbars is effectively shortened, thereby reducing the current transmission distance and lowering the internal transmission loss of the photovoltaic module.

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic power generation, and particularly relates to a photovoltaic module. Background Art

[0002] In a photovoltaic module, light energy is converted into electrical energy through the photovoltaic effect of solar cells, and multiple solar cells are connected in series through busbars, so that the electrical energy generated by the solar cells is collected and led out by the busbars. In the prior art, the current transmission path of the busbars in the photovoltaic module is relatively long, which increases the internal transmission loss of the photovoltaic module, and further affects the power and power generation of the photovoltaic module. Summary of the Invention

[0003] Based on this, it is necessary to provide a photovoltaic module for solving the problem of large internal transmission loss of the photovoltaic module.

[0004] A photovoltaic module includes a backsheet and a battery string layer disposed on one side of the backsheet. The backsheet is provided with a plurality of lead-out holes arranged at intervals in a first direction. The battery string layer includes:

[0005] Multiple groups of battery string groups arranged at intervals in the first direction. Each group of battery string groups includes two sub-battery string groups arranged at intervals in the first direction. Each sub-battery string group includes two battery strings arranged at intervals in a second direction;

[0006] Multiple intermediate busbars. Each intermediate busbar is located between two battery strings of the same group in the second direction. One end of each intermediate busbar is correspondingly connected to a group of sub-battery string groups, and the other end of each intermediate busbar extends out of the lead-out hole;

[0007] Wherein, the second direction is perpendicular to the first direction.

[0008] In one embodiment, one end of each intermediate busbar is bent in the thickness direction of the photovoltaic module to form a first lead-out end, and the first lead-out end extends out of the lead-out hole.

[0009] In one embodiment, among the two intermediate busbars connecting two sub-battery string groups of the same group, the two first lead-out ends extend out of the same lead-out hole and are connected to each other.

[0010] In one embodiment, among the two intermediate busbars extending out of the same lead-out hole, the distance between the bending portions of the two first lead-out ends is 0-3 mm.

[0011] In one embodiment, the photovoltaic module further includes a plurality of diodes, and two of the first lead-out ends led out from the same lead-out hole are correspondingly connected to the same end of one of the diodes. In one embodiment, the battery string layer further includes a plurality of jumpers, a part of each jumper is connected to at least one group of the battery string groups, and the other part of the jumper extends out of the lead-out hole.

[0012] In one embodiment, each jumper includes a first extension section and a second extension section. Two ends of the first extension section are respectively connected to one end of the battery string far from the middle bus bar. The second extension section is connected to the first extension section, and at least one end of the second extension section extends along the first direction and extends out of the lead-out hole.

[0013] In one embodiment, an end of the second extension section is bent along the thickness direction of the photovoltaic module to form a second lead-out end, and the second lead-out end extends out of the lead-out hole.

[0014] In one embodiment, among the middle bus bar and the second lead-out end led out from the same lead-out hole, the distance between the middle bus bar and the bent part of the second lead-out end is 6 mm - 10 mm. In one embodiment, the photovoltaic module further includes a plurality of diodes, and the second lead-out end is correspondingly connected to one end of one of the diodes.

[0015] In one embodiment, the second extension section and the middle bus bar are stacked in the thickness direction of the photovoltaic module.

[0016] In one embodiment, an insulating strip is provided between the second extension section and the middle bus bar.

[0017] In one embodiment, one end of the insulating strip protrudes from the bent part of the second extension section.

[0018] In one embodiment, two battery strings in the same group respectively have a first solder tape and a second solder tape connected to the middle bus bar, and the first solder tape and the second solder tape are arranged in a staggered manner in the second direction.

[0019] For the above photovoltaic module, since the middle bus bar adopts a split design, that is, each middle bus bar is only correspondingly connected to one group of sub-battery string groups. Compared with connecting multiple groups of sub-battery string groups by continuously extending one middle bus bar, the length of at least part of the middle bus bar is effectively shortened, thereby reducing the current transmission distance inside the photovoltaic module, optimizing the current transmission path, reducing the internal transmission loss of the photovoltaic module, and thus effectively improving the power and power generation amount of the photovoltaic module. Description of the Drawings

[0020] The accompanying drawings, which form a part of this application, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for description in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other accompanying drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a schematic structural diagram of a photovoltaic module according to an embodiment of this application.

[0023] Figure 2 It is a circuit diagram of a photovoltaic module according to an embodiment of this application.

[0024] Figure 3 It is a schematic structural diagram at an extraction hole of a photovoltaic module according to an embodiment of this application.

[0025] Figure 4 It is a schematic structural diagram at an extraction hole of a photovoltaic module according to an embodiment of this application.

[0026] Figure 5 It is a schematic partial structural diagram of a photovoltaic module according to an embodiment of this application.

[0027] Figure 6 It is a circuit diagram of a photovoltaic module according to an embodiment of this application.

[0028] Explanation of reference numerals:

[0029] 1000, photovoltaic module;

[0030] 100, battery string layer; 120, battery string group; 120a, first battery string group, 120b, second battery string group, 120c, third battery string group; 121, sub - battery string group; 1212, battery string; 1211, battery cell; 1213, welding strip; 140, middle busbar; 141, first extraction end; 140a, first middle busbar; 140b, second middle busbar; 140c, third middle busbar; 140d, fourth middle busbar; 140e, fifth middle busbar; 140f, sixth middle busbar; 150, edge busbar; 160, jumper; 161, first extension segment; 163, second extension segment; 1632, second extraction end; 160a, first jumper; 160b, second jumper; 180, insulating strip; 181, first insulating segment; 183, second insulating segment;

[0031] 200. Backplane; 210. Lead-out hole; 210a. First lead-out hole; 210b. Second lead-out hole; 210c. Third lead-out hole. Detailed implementation manner

[0032] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manner of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that if terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0034] In addition, if terms such as "first" and "second" appear, these terms are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0035] In the present application, unless otherwise clearly specified and limited, if terms such as "installation", "connection", "connection", "fixation", etc. appear, these terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0036] In this application, unless otherwise clearly specified and defined, when a first feature is described as being "on" or "under" a second feature or the like, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0037] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. If an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0038] Referring to Figure 1 and Figure 2 , an embodiment of the present application provides a photovoltaic module 1000. Along the thickness direction of the photovoltaic module 1000, it includes a backsheet 200, a battery string layer 100, a cover plate and a frame. A glue film layer is provided between the backsheet 200 and the battery string layer 100, and between the battery string layer 100 and the cover plate. After the backsheet 200, the battery string layer 100 and the cover plate are laminated, a laminate is formed, and the frame is disposed on the outer periphery of the laminate to protect the edge of the laminate.

[0039] In the following embodiments, the photovoltaic module 1000 is generally rectangular. The width direction of the photovoltaic module 1000 is defined as the first direction (i.e., Figure 1 the X direction in Figure 1 ), the length direction of the photovoltaic module 1000 is defined as the second direction (i.e., Figure 4 the Y direction in

[0040] The battery string layer 100 includes multiple groups of battery string groups 120. All the battery string groups 120 are arranged at intervals in the first direction, and all the battery string groups 120 can be connected in parallel or in series with each other. Each group of battery string groups 120 includes two sub-battery string groups 121 arranged at intervals in the first direction. Each sub-battery string group 121 includes two battery strings 1212 arranged at intervals in the second direction. The four battery strings 1212 of each group of battery string groups 120 can be connected in parallel with each other. Each battery string 1212 includes multiple solar cells 1211. All the solar cells 1211 of the same battery string 1212 are arranged in the second direction and can be connected in series with each other.

[0041] The solar cell 1211 is specifically a multi-segmented solar cell. The types of multi-segmented solar cells include, but are not limited to, the emitter: Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCon), Heterojunction with Intrinsic Thin-film (HJT), Interdigitated Back Contact (IBC), perovskite cell, multi-busbar cell (MBB), and non-busbar cell (0BB).

[0042] For a PERC cell, along its thickness direction, it sequentially includes a front surface metal silver electrode, a front surface silicon nitride passivation layer, a phosphorus layer emitter, a P-type substrate silicon layer, a local aluminum back surface field, a metal aluminum back electrode, and a back passivation layer (Al2O3 / SiNx). Since the PERC cell uses a passivation film to passivate the back surface instead of a full aluminum back surface field, the internal back reflection of light in the silicon substrate is enhanced, and the back surface recombination rate is reduced, thereby increasing the efficiency of the cell by 0.5% - 1%.

[0043] For a TOPCon cell, along its thickness direction, it sequentially includes a metal silver electrode, a front surface silicon nitride passivation layer, a boron-doped emitter, an N-type substrate silicon layer, a diffusion doping layer, an ultra-thin silicon oxide, doped polycrystalline silicon, silicon nitride, and a metal silver electrode. The back surface of the cell is composed of an ultra-thin silicon oxide (1nm - 2nm) and a phosphorus-doped microcrystalline amorphous hybrid Si film, and the two together form a passivated contact structure, which can block the recombination of minority carriers holes, improve the open-circuit voltage and short-circuit current of the cell. The ultra-thin oxide layer allows majority carrier electrons to tunnel into the polycrystalline silicon layer while blocking the recombination of minority carrier holes. The good passivation effect of the ultra-thin silicon oxide and the heavily doped silicon film causes the energy band on the surface of the silicon wafer to bend, thereby forming a field passivation effect. The probability of electron tunneling increases significantly, and the contact resistance decreases, thereby improving the open-circuit voltage and short-circuit current of the cell, and further improving the conversion efficiency of the cell.

[0044] For HJT cells, along its thickness direction, it sequentially includes a front low-temperature silver electrode, a front conductive thin film, an N-type amorphous silicon thin film, an intrinsic amorphous silicon thin film, an N-type substrate silicon layer, an intrinsic amorphous silicon thin film, a P-type amorphous silicon thin film, a back conductive thin film, and a back low-temperature silver electrode.

[0045] For IBC cells, along its thickness direction, it sequentially includes a silicon nitride anti-reflection layer, an N+ front surface field, an N-type substrate silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride anti-reflection layer, and a metal silver electrode. IBC cells can obtain P regions and N regions with good uniformity and precisely controllable junction depth by using ion implantation technology. There are no grid lines blocking on the front of the cell, which can eliminate the shading current loss of the metal electrodes and maximize the utilization of incident photons. The short-circuit current of the IBC cell can be increased by about 7% compared with conventional solar cells. Moreover, due to the back contact structure, there is no need to consider the problem of grid line occlusion. Therefore, the grid line ratio can be appropriately widened, thereby reducing the series resistance and having a high fill factor. And the surface passivation and surface light trapping structure can be optimized, resulting in a lower front surface recombination rate and surface reflection.

[0046] For perovskite cells, along its thickness direction, it sequentially includes a substrate material, a conductive thin film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by perovskite materials are converted into electrons, they are easily collected by the electrodes with less loss. Therefore, perovskite can generate a high photo-generated voltage and current, making perovskite exhibit a high photoelectric conversion efficiency.

[0047] For multi-main grid cells, multiple main grids for collecting current are arranged on the surface of the cell sheet 1211, which shortens the current conduction path in the multi-main grid cells, reduces internal losses, and further improves the power of the multi-main grid cells. As the number of main grids increases, the cross-sectional areas of the main grids and the solder tapes 1213 decrease, and the adhesive film layer is thinner, thereby reducing the production cost of the photovoltaic module 1000. As the number of main grids increases, the number of fine grids can be correspondingly reduced, thus reducing the production cost of the cell sheet 1211.

[0048] For main-grid-free cells, there are no main grids on the surface of the cell sheet 1211. After multiple cell sheets 1211 are welded, the solder tapes directly connect to the original main grids and fine grids instead, which can reduce the consumption of silver paste and thus reduce the production cost of the cell sheet 1211. Moreover, main-grid-free cells can reduce the shading area of the grid lines in the cell sheet 1211 and reduce the fine grid transmission loss, improving the total power of the module. At the same time, the increase in the number of fine grid contact points reduces the risk of hidden cracks in thin silicon wafers, improving the yield and reliability.

[0049] Multiple cells 1211 in the battery string 1212 can be welded by the overlapping welding technique. Two adjacent cells 1211 overlap each other, and the size of the overlapping area can be from 0.2 mm to 0.6 mm. A solder strip 1213 is arranged in the overlapping area of two adjacent cells 1211, so that two adjacent cells 1211 are connected in series to form the battery string 1212. The multiple cells 1211 in the battery string 1212 are connected in series by the overlapping welding method, which can reduce the distance between the multiple cells 1211 in the battery string 1212, increase the proportion of the area of the cells 1211 in the photovoltaic module 1000, and further increase the effective light absorption area in the photovoltaic module 1000, and finally improve the power generation power of the photovoltaic module 1000. Since two adjacent cells 1211 are overlapped and a solder strip 1213 is arranged in the overlapping area, stress concentration is likely to occur in the overlapping area during the lamination process. Therefore, a buffer layer can also be arranged in the overlapping area of two adjacent cells 1211, so as to reduce the possibility of the cells 1211 cracking during the lamination process.

[0050] The cell 1211 can be a two-piece cell, a three-piece cell, a four-piece cell, etc. In this application, taking the four-piece cell as an example, a complete cell is divided into four equal parts to form a four-piece cell. According to the different sizes of the complete cell, the length of the four-piece cell can be 182.3 mm, and the width can be from 46.675 mm to 53.25 mm. After the multiple four-piece cells in the battery string 1212 are overlapped and welded, the width of the overlapping area between two adjacent four-piece cells can be from 0.2 mm to 0.6 mm, and the distance between two adjacent battery strings 1212 can be from 1.2 mm to 1.6 mm, so that the length of the photovoltaic module 1000 can be from 2278 mm to 2382 mm, and the width can be 1134 mm. The current of the four-piece cell is 1 / 4 of the current of the bent cell, so the current of a single battery string 1212 is also 1 / 4 of the current of the complete cell, thus reducing the power loss of a single battery string 1212 and realizing the power improvement of the photovoltaic module 1000.

[0051] Further, the battery string layer 100 further includes a plurality of middle busbars 140, a plurality of edge busbars 150, and a plurality of jumpers 160.

[0052] Each middle busbar 140 is located between two battery strings 1212 in the same group in the second direction. Each middle busbar 140 extends in the first direction. One end of each middle busbar 140 is correspondingly connected to a sub-battery string group 121, and the other end of each middle busbar 140 is connected to an external device through a junction box. Specifically, in some embodiments, the middle busbar 140 is formed by a conductive metal strip. The width of the middle busbar 140 is preferably from 4 mm to 12 mm, and the thickness is preferably from 0.15 mm to 0.4 mm.

[0053] In one embodiment, two battery strings 1212 in the same group respectively have a first solder strip and a second solder strip connected to the middle bus bar 140. The first solder strip and the second solder strip are arranged offset in the second direction, and the distance c between the closest first solder strip and the second solder strip is less than 0.5 mm (please refer to Figure 4 ). The offset solder strips 1213 can prevent the solder strips 1213 of adjacent battery strings 1212 from overlapping, thereby increasing the thickness of the laminate and ultimately affecting the yield rate of the photovoltaic module 1000.

[0054] Edge bus bars 150 are provided at opposite ends of all battery string groups 120 in the second direction. Each edge bus bar 150 extends in the first direction, and one end of each battery string 1212 away from the middle bus bar 140 is connected to the edge bus bar 150. Specifically, in some embodiments, the edge bus bar 150 is formed by a conductive metal strip, and the width of the edge bus bar 150 is preferably 4 mm - 12 mm, and the thickness is preferably 0.15 mm - 0.4 mm.

[0055] A part of the jumper 160 is connected to the edge bus bar 150, and the other part is connected to an external device through a junction box. Specifically, in some embodiments, the jumper 160 is formed by a conductive metal strip, and the width of the jumper 160 is preferably 4 mm to 8 mm, and the thickness is preferably 0.15 mm to 0.4 mm.

[0056] Conversely, if the width of the jumper 160 is less than 4 mm and the thickness is less than 0.15 mm at the same time, it will result in a smaller cross-sectional area of the jumper 160, thereby resulting in a poor current-carrying capacity of the jumper 160 and being unable to carry the current in the photovoltaic module 1000. If the width of the jumper 160 is greater than 8 mm, the size of the overlapping area between the jumper 160 and the battery cell 1211 increases. During the lamination process, the jumper 160 will increase the risk of the battery cell 1211 cracking. Especially when the photovoltaic module 1000 is a double-glass module, since both sides of the battery cell 1211 are used to absorb sunlight, a too large width of the jumper 160 will increase the shielding of the battery cell 1211, thereby affecting the power generation efficiency.

[0057] As described in the background art, in existing photovoltaic modules, multiple battery cells are connected in series through bus bars, and the electric energy generated by the battery cells is poured out after the bus bars. With the increase in the size of the battery cells, the current in a single battery string formed by connecting multiple battery cells in series is large, resulting in a large power loss of the photovoltaic module.

[0058] In order to reduce the current within a single cell string and thereby lower the power loss of a photovoltaic module, in some solutions, large-sized cells are designed with multiple sub-divisions to reduce the current within a single cell string. By first connecting in parallel and then in series, it is ensured that the electrical parameters of the component product are the same as those of a half-cell module of the same size, eliminating the impact on terminal applications. However, at the same time, the number of backplane openings for the busbar lead-out is reduced, resulting in an increase in the number of busbars at the openings. Not only does the opening diameter need to be correspondingly increased, but also the current transmission distance of the outer cell string is increased compared to that of the inner cell string, thereby increasing the internal loss of the photovoltaic module. Moreover, the difficulty of automatically installing the junction box increases, and the distance between the lines is small, thus increasing the short-circuit risk. In addition, due to the increase in the number of diodes in the junction box, the volume of the junction box also increases accordingly, which is not conducive to the temperature control of the junction box.

[0059] For the above technical problems, please refer to Figure 2 、 Figure 3 and Figure 4 In the present application, the backplane 200 is provided with a plurality of lead-out holes 210 arranged at intervals along the first direction. One end of each intermediate busbar 140 is correspondingly connected to a group of sub-cell string groups 121, and the other end of each intermediate busbar 140 extends out of the lead-out hole 210 and is then connected to an external device through a junction box.

[0060] Since the intermediate busbar 140 adopts a split design, that is, each intermediate busbar 140 is only correspondingly connected to a group of sub-cell string groups 121, compared with connecting multiple groups of sub-cell string groups 121 by continuously extending one intermediate busbar 140, the length of at least part of the intermediate busbar 140 is effectively shortened. Thereby, the current transmission distance within the photovoltaic module 1000 is reduced, the current transmission path is optimized, the internal transmission loss of the photovoltaic module 1000 is reduced, and thus the power and power generation of the photovoltaic module 1000 are effectively improved.

[0061] Specifically, in one embodiment, one end of each intermediate busbar 140 is bent along the third direction to form a first lead-out end 141, and the first lead-out end 141 extends out of the lead-out hole 210, and is then connected to an external device through a junction box.

[0062] In some embodiments, among the two intermediate busbars 140 connecting two groups of sub-cell string groups 121 in the same group, the two first lead-out ends 141 extend out of the same lead-out hole 210 and are connected to each other by means such as welding, thereby connecting the two groups of sub-cell string groups 121 in parallel. As a preferred embodiment, as Figure 4 shown, the distance a between the bending parts of the two first lead-out ends 141 is 0 - 3 mm, which facilitates welding the two first lead-out ends 141.

[0063] In some embodiments, the photovoltaic module 1000 further includes a plurality of diodes. The diodes are received in a junction box, and two first lead-out ends 141 led out from the same lead-out hole 210 are correspondingly connected to the same end of a diode.

[0064] A part of each jumper 160 is connected to at least one set of battery string groups 120, and the other part of the jumper 160 extends out of the lead-out hole 210, so as to be connected to an external device through the junction box.

[0065] Specifically, in one embodiment, each jumper 160 includes a first extension section 161 and a second extension section 163. The first extension section 161 is located between two adjacent sets of battery string groups 120. The first extension section 161 extends along the second direction, and the two ends of the first extension section 161 are respectively connected to the edge busbars 150 at the ends of the battery strings 1212 far from the middle busbar 140. The second extension section 163 is connected to the first extension section 161, and at least one end of the second extension section 163 extends along the first direction and extends out of the lead-out hole 210.

[0066] In one embodiment, the end of the second extension section 163 is bent along the thickness direction of the photovoltaic module 1000 to form a second lead-out end 1632, and the second lead-out end 1632 extends out of the lead-out hole 210 to be connected to the diode in the junction box.

[0067] In some embodiments, two first lead-out ends 141 of two middle busbars 140 and the second lead-out end 1632 of the jumper 160 are led out from the same lead-out hole 210. The two first lead-out ends 141 are connected to the same end of a diode, and the second lead-out end 1632 is connected to the other end of the diode, so that a plurality of battery strings 1212 are electrically connected to the diode.

[0068] As a preferred embodiment, as Figure 4 shown, among the first lead-out end 141 of the middle busbar 140 and the second lead-out end 1632 led out from the same lead-out hole 210, the distance b between the middle busbar 140 and the bending position of the second lead-out end 1632 is 6 mm - 10 mm, so as to meet the electrical safety requirements. It should be noted that the distance between the middle busbar 140 and the bending position of the second lead-out end 1632 in the foregoing specifically refers to the distance between the whole formed after the welding of the first lead-out ends 141 of the two middle busbars 140 and the bending position of the second lead-out end 1632.

[0069] In some embodiments, the battery string layer 100 further includes an insulating strip 180. The insulating strip 180 is partially located between the jumper 160 and the cell 1211, and partially located between the jumper 160 and the intermediate bus bar 140. The insulating strip 180 is made of an insulating material and is used to separate the jumper 160 from the cell 1211 and the jumper 160 from the intermediate bus bar 140, so as to prevent the two from contacting and causing a short - circuit phenomenon, thereby improving the safety of the photovoltaic module 1000.

[0070] Specifically, in one embodiment, please refer to Figure 1 、 Figure 4 、 Figure 5 As shown, the insulating strip 180 includes a first insulating section 181 and a second insulating section 183. The first insulating section 181 extends along the second direction and is located between the first extension section 161 of the jumper 160 and the cell 1211 in the third direction. The second insulating section 183 extends along the first direction and is stacked between the second extension section 163 of the jumper 160 and the intermediate bus bar 140 in the third direction, and the end of the second insulating section 183 extends to the lead - out hole 210.

[0071] As a preferred embodiment, the distance between the end of the second insulating section 183 at the lead - out hole 210 and the bending point of the first lead - out end 141 of the intermediate bus bar 140 below it is 0 - 2 mm, and the end of the second insulating section 183 at the lead - out hole 210 protrudes from the bending point of the second lead - out end 1632 of the jumper 160, so as to prevent the second extension section 163 of the jumper 160 from contacting the second insulating section 183 of the insulating strip 180 and causing a short - circuit.

[0072] As a preferred embodiment, the width of the insulating strip 180 is 8 mm to 20 mm, and the thickness is 0.1 mm to 0.3 mm.

[0073] Taking the first insulating section 181 as an example, since the first insulating section 181 is used to separate the jumper 160 from the cell 1211, the first extension section 161 of the jumper 160 is centered on the first insulating section 181, reducing the possibility of short - circuit caused by their contact. Therefore, the width of the first insulating section 181 needs to be greater than the width of the first extension section 161. If the width of the first insulating section 181 is less than 8 mm, it will increase the possibility of short - circuit caused by the contact between the first extension section 161 and the cell 1211. If the width of the first insulating section 181 is greater than 20 mm, the overlapping area between the first insulating section 181 and the cell 1211 will also increase, resulting in an increased influence of the first insulating section 181 on the cell 1211 during the lamination process, especially in a double - glass module, which has a greater impact on the power generation efficiency.

[0074] On the one hand, since the first insulating section 181 is located between the first extension section 161 and the cell 1211, if the thickness of the first insulating section 181 is greater than 0.3 mm, the thicknesses of the first extension section 161 and the first insulating section 181 will be too large. During the lamination process, the stress at the position of the first extension section 161 is relatively large, which easily causes the cell 1211 to have hidden cracks. On the other hand, the first insulating section 181 plays an insulating role between the first extension section 161 and the cell 1211. The insulating performance of the first insulating section 181 decreases as the thickness of the first insulating section 181 decreases. Therefore, if the thickness of the first insulating section 181 is less than 0.1 mm, the insulating performance of the first insulating section 181 will be relatively poor, and then the possibility of short circuit between the first extension section 161 and the cell 1211 will be relatively large.

[0075] Please refer to Figure 1 , Figure 2 and Figure 6 as shown. Specifically, in an embodiment, the backsheet 200 is provided with three lead-out holes 210 arranged at intervals in the first direction. Along Figure 1 from right to left are the first lead-out hole 210a, the second lead-out hole 210b, and the third lead-out hole 210c in sequence.

[0076] The cell string layer 100 includes three groups of cell string groups 120 arranged at intervals in the first direction. Along Figure 6 from right to left are the first cell string group 120a, the second cell string group 120b, and the third cell string group 120c in sequence. Each group of cell string groups 120 includes two sub-cell string groups 121 arranged at intervals in the first direction (that is, the cell string layer 100 includes six sub-cell string groups 121). The first lead-out hole 210a is located between the two sub-cell string groups 121 of the first cell string group 120a. The second lead-out hole 210b is located between the two sub-cell string groups 121 of the second cell string group 120b. The third lead-out hole 210c is located between the two sub-cell string groups 121 of the third cell string group 120c.

[0077] Corresponding to the six sub-cell string groups 121, the cell string layer 100 includes six intermediate busbars 140 arranged at intervals in the first direction. Along Figure 6 from right to left are the first intermediate busbar 140a, the second intermediate busbar 140b, the third intermediate busbar 140c, the fourth intermediate busbar 140d, the fifth intermediate busbar 140e, and the sixth intermediate busbar 140f in sequence.

[0078] Among them, the first intermediate bus bar 140a and the second intermediate bus bar 140b are respectively connected to two sub-battery string groups 121 of the first battery string group 120a. One end of the first intermediate bus bar 140a and one end of the second intermediate bus bar 140b respectively form a first lead-out end 141 and are led out through the first lead-out hole 210a. The first lead-out end 141 of the first intermediate bus bar 140a and the first lead-out end 141 of the second intermediate bus bar 140b are connected to each other and connected to the same end of a diode.

[0079] The third intermediate bus bar 140c and the fourth intermediate bus bar 140d are respectively connected to two sub-battery string groups 121 of the second battery string group 120b. One end of the third intermediate bus bar 140c and one end of the fourth intermediate bus bar 140d respectively form a first lead-out end 141 and are led out through the second lead-out hole 210b. The first lead-out end 141 of the third intermediate bus bar 140c and the first lead-out end 141 of the fourth intermediate bus bar 140d are connected to each other and connected to the same end of a diode.

[0080] The fifth intermediate bus bar 140e and the sixth intermediate bus bar 140f are respectively connected to two sub-battery string groups 121 of the third battery string group 120c. One end of the fifth intermediate bus bar 140e and one end of the sixth intermediate bus bar 140f respectively form a first lead-out end 141 and are led out through the third lead-out hole 210c. The first lead-out end 141 of the fifth intermediate bus bar 140e and the first lead-out end 141 of the sixth intermediate bus bar 140f are connected to each other and connected to the same end of a diode.

[0081] The battery string layer 100 includes two jumper wires 160, which are Figure 6 the first jumper wire 160a and the second jumper wire 160b in sequence from right to left. The first extension section 161 of the first jumper wire 160a is located between the first battery string group 120a and the second battery string group 120b. Both ends of the first extension section 161 are respectively connected to the opposite ends of the first battery string group 120a in the second direction through the edge bus bar 150. One end of the second extension section 163 of the first jumper wire 160a is connected to the middle position of the first extension section 161, and the other end of the second extension section 163 extends along the first direction and extends out of the first lead-out hole 210a, and then is connected to the other end of the diode connecting the first intermediate bus bar 140a and the second intermediate bus bar 140b.

[0082] The first extension section 161 of the second jumper 160b is located between the second battery string group 120b and the third battery string group 120c. Both ends of the first extension section 161 are respectively connected to the opposite ends of the second battery string group 120b and the third battery string group 120c in the second direction through the edge bus bar 150. The middle part of the second extension section 163 of the second jumper 160b is connected to the middle position of the first extension section 161. Both ends of the second extension section 163 extend in opposite directions along the first direction to respectively extend out of the second lead-out hole 210b and the third lead-out hole 210c. One end of the second extension section 163 is connected to the other end of the diode connecting the third middle bus bar 140c and the fourth middle bus bar 140d. The other end of the second extension section 163 is connected to the other end of the diode connecting the fifth middle bus bar 140e and the sixth middle bus bar 140f.

[0083] The photovoltaic module 1000 includes three diodes. The three diodes are housed in a three-part junction box. The first battery string group 120a, the second battery string group 120b, and the third battery string group 120c are respectively connected to one diode. Specifically, one end of one diode is connected to the first middle bus bar 140a and the second middle bus bar 140b, and the other end is connected to the first jumper 160a. One end of one diode is connected to the third middle bus bar 140c and the fourth middle bus bar 140d, and the other end is connected to one end of the second extension section 163 of the second jumper 160b. One end of one diode is connected to the fifth middle bus bar 140e and the sixth middle bus bar 140f, and the other end is connected to the other end of the second extension section 163 of the second jumper 160b.

[0084] Since the three-part junction box is used to install the diodes, the structure of the junction box is simplified, the installation efficiency of the junction box is improved, and the risk of excessive junction temperature of the junction box is reduced. When a certain solar cell 1211 fails, the diode can play a conduction role to skip the faulty battery string group 120, playing a role in protecting the circuit. The structure of the junction box is not limited to this and can be set according to needs to meet different installation requirements.

[0085] On the premise that the photovoltaic module 1000 of the present application adopts the connection method of first parallel and then series, the lead-out holes 210 adopt the conventional opening settings, solving the problem of increased opening in the prior art. Since the middle bus bar 140 adopts a split design, the problem of different current transmission lengths of different battery string groups 120 is solved, the circuit transmission path is optimized, the internal loss is effectively reduced, and thus the power and power generation of the photovoltaic module 1000 are improved. In addition, the first lead-out end 141 of the middle bus bar 140 and the second lead-out end 1632 of the jumper 160 are arranged in the same orientation, solving the problem of difficult installation of the junction box and effectively reducing the short-circuit risk.

[0086] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0087] The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A photovoltaic module, characterized in that, It includes a backplane (200) and a battery string layer (100) provided on one side of the backplane (200). The backplane (200) is provided with a plurality of lead-out holes (210) arranged at intervals in a first direction. The battery string layer (100) includes: Multiple groups of battery string groups (120) arranged at intervals in the first direction. Each group of battery string groups (120) includes two sub-battery string groups (121) arranged at intervals in the first direction. Each sub-battery string group (121) includes two battery strings (1212) arranged at intervals in a second direction; Multiple intermediate busbars (140). Each intermediate busbar (140) is located between two battery strings (1212) of the same group in the second direction. One end of each intermediate busbar (140) is correspondingly connected to a group of sub-battery string groups (121). The other end of each intermediate busbar (140) is bent in the thickness direction of the photovoltaic module to form a first lead-out end (141). Among the two intermediate busbars (140) connecting two groups of sub-battery string groups (121) of the same group, the two first lead-out ends (141) extend out of the same lead-out hole (210) and are connected to each other; Wherein, the second direction is perpendicular to the first direction.

2. The photovoltaic module according to claim 1, wherein, Among the two intermediate busbars (140) extending out of the same lead-out hole (210), the distance between the bending points of the two first lead-out ends (141) is 0 - 3 mm.

3. The photovoltaic module according to claim 1, wherein The photovoltaic module further includes a plurality of diodes. The two first lead-out ends (141) led out from the same lead-out hole (210) are correspondingly connected to the same end of a diode.

4. The photovoltaic module according to claim 1, wherein The battery string layer (100) further includes multiple jumpers (160). A part of each jumper (160) is connected to at least one group of battery string groups (120), and the other part of the jumper (160) extends out of the lead-out hole (210).

5. The photovoltaic module according to claim 4, wherein, Each jumper (160) includes a first extension section (161) and a second extension section (163). The two ends of the first extension section (161) are respectively connected to the ends of the battery string (1212) far from the intermediate busbar (140). The second extension section (163) is connected to the first extension section (161). At least one end of the second extension section (163) extends in the first direction and extends out of the lead-out hole (210).

6. The photovoltaic module according to claim 5, wherein The end of the second extension section (163) is bent in the thickness direction of the photovoltaic module to form a second lead-out end (1632), and the second lead-out end (1632) extends out of the lead-out hole (210).

7. The photovoltaic module according to claim 6, characterized in that, Among the intermediate busbar (140) and the second lead-out end (1632) led out from the same lead-out hole (210), the distance between the bending points of the intermediate busbar (140) and the second lead-out end (1632) is 6 mm - 10 mm.

8. The photovoltaic module according to claim 6, wherein, The photovoltaic module further includes a plurality of diodes. The second lead-out end (1632) is correspondingly connected to one end of a diode.

9. The photovoltaic module according to claim 5, characterized in that The second extension section (163) and the intermediate bus bar (140) are stacked in the thickness direction of the photovoltaic module.

10. The photovoltaic module according to claim 9, characterized in that, An insulating strip (180) is provided between the second extension section (163) and the intermediate bus bar (140).

11. The photovoltaic module according to claim 10, wherein One end of the insulating strip (180) protrudes from the bent portion of the second extension section (163).

12. The photovoltaic module according to any one of claims 1 to 11, characterized in that, Two cell strings (1212) in the same group respectively have a first solder tape and a second solder tape connecting the intermediate bus bar (140), and the first solder tape and the second solder tape are arranged in a staggered manner in the second direction.

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