Photovoltaic module

Abstract

The invention relates to a photovoltaic module, which comprises a back plate and a battery string layer arranged on one side of the back plate, the back plate is provided with a plurality of lead-out holes arranged at intervals along a first direction, the battery string layer comprises a plurality of battery string groups arranged at intervals along the first direction, each battery string group comprises two sub battery string groups arranged at intervals along the first direction, each sub-battery string group comprises two battery strings which are arranged at an interval along a second direction; and each middle bus bar is located between the two battery strings in the same group in the second direction, one end of each middle bus bar is correspondingly connected with one sub-battery string group, and the other end of each middle bus bar extends out of the lead-out hole. According to the photovoltaic module, as each middle bus bar is only correspondingly connected with one sub-battery string group, compared with the mode that one middle bus bar continuously extends to connect multiple sub-battery string groups, the length of at least part of the middle bus bars is effectively shortened, the current transmission distance is further reduced, and the internal transmission loss of the photovoltaic module is reduced.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic module. Background Art

[0002] Photovoltaic modules convert light energy into electrical energy through the photovoltaic effect of the cells. Multiple cells are connected in series through bus bars, so that the electrical energy generated by the cells is collected and then exported by the bus bars. In the prior art, the current transmission path of the bus bars in the photovoltaic modules is long, which increases the internal transmission loss of the photovoltaic modules, thereby affecting the power and power generation of the photovoltaic modules. Summary of the invention

[0003] Based on this, it is necessary to provide a photovoltaic module to address the problem of large internal transmission losses in photovoltaic modules.

[0004] A photovoltaic module comprises a back plate and a battery string layer arranged on one side of the back plate, wherein the back plate is provided with a plurality of lead-out holes arranged at intervals along a first direction, and the battery string layer comprises:

[0005] A plurality of battery string groups are arranged at intervals along the first direction, each of the battery string groups comprises two sub-battery string groups arranged at intervals along the first direction, and each of the sub-battery string groups comprises two battery strings arranged at intervals along the second direction;

[0006] A plurality of intermediate bus bars, each of which is located between two battery strings of the same group in the second direction, one end of each of which is connected to a corresponding group of sub-battery strings, and the other end of each of which extends out of the lead-out hole;

[0007] The second direction is perpendicular to the first direction.

[0008] In one embodiment, one end of each of the intermediate bus bars is bent along 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, in the two intermediate bus bars connecting two sub-battery strings of the same group, two first lead-out ends extend out of the same lead-out hole and are connected to each other.

[0010] In one embodiment, in the two middle bus bars extending out of the same lead-out hole, the distance between the bending parts of the two first lead-out ends is 0-3 mm.

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

[0012] In one embodiment, each of the jumpers includes a first extension section and a second extension section, wherein two ends of the first extension section are respectively connected to one end of the battery string away from the middle bus bar, and 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 of the embodiments, the end of the second extension section is bent along the thickness direction of the photovoltaic component to form a second lead-out end, and the second lead-out end extends out of the lead-out hole.

[0014] In one embodiment, in the intermediate bus bar and the second lead-out end led out from the same lead-out hole, the distance between the intermediate bus bar and the bending part of the second lead-out end is 6mm-10mm. 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 segment and the middle bus bar are stacked in a thickness direction of the photovoltaic component.

[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 bend of the second extension section.

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

[0019] The above-mentioned photovoltaic module adopts a split design for the intermediate bus bar, that is, each intermediate bus bar only corresponds to connecting one group of sub-battery strings. Compared with continuously extending an intermediate bus bar to connect multiple groups of sub-battery strings, the length of at least part of the intermediate bus bar is effectively shortened, thereby reducing the current transmission distance inside the photovoltaic module, optimizing the current transmission path, and reducing the internal transmission loss of the photovoltaic module, thereby effectively improving the power and power generation of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic structural diagram of a photovoltaic assembly according to an embodiment of the present application.

[0023] Figure 2 This is a circuit diagram of a photovoltaic module according to an embodiment of the present application.

[0024] Figure 3 It is a schematic structural diagram of a lead-out hole of a photovoltaic assembly according to an embodiment of the present application.

[0025] Figure 4 It is a schematic structural diagram of a lead-out hole of a photovoltaic assembly according to an embodiment of the present application.

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

[0027] Figure 6 This is a circuit diagram of a photovoltaic module according to an embodiment of the present application.

[0028] Description of reference numerals:

[0029] 1000. Photovoltaic modules;

[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, intermediate bus bar; 141, first lead-out terminal; 140a, first intermediate bus bar; 140b, second intermediate bus bar; 140c, third 3rd intermediate bus bar; 140d, 4th intermediate bus bar; 140e, 5th intermediate bus bar; 140f, 6th intermediate bus bar; 150, edge bus bar; 160, jumper; 161, first extension section; 163, second extension section; 1632, second lead-out terminal; 160a, first jumper; 160b, second jumper; 180, insulating strip; 181, first insulating section; 183, second insulating section;

[0031] 200, back plate; 210, lead-out hole; 210a, first lead-out hole; 210b, second lead-out hole; 210c, third lead-out hole. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of 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 violating the connotation of the present application, so 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 the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

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

[0035] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" 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 is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level 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 be a central 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 a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0038] See also Figure 1 and Figure 2 The embodiment of the present application provides a photovoltaic module 1000, which includes a back plate 200, a battery string layer 100, a cover plate and a frame along its thickness direction. A film layer is provided between the back plate 200 and the battery string layer 100, and between the battery string layer 100 and the cover plate. The back plate 200, the battery string layer 100 and the cover plate are laminated to form a laminate, and the frame is provided on the periphery of the laminate to protect the edge of the laminate.

[0039] In the following embodiments, the photovoltaic assembly 1000 is rectangular in shape as a whole, and the width direction of the photovoltaic assembly 1000 is defined as the first direction (i.e. Figure 1 The length direction of the photovoltaic module 1000 is defined as the second direction (i.e. Figure 1 The thickness direction of the photovoltaic module 1000 is defined as the third direction (i.e. Figure 4 The first direction, the second direction and the third direction are perpendicular to each other.

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

[0041] The cell 1211 is specifically a multi-slice cell, and the types of multi-slice cells include but are not limited to emitters: Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCon), Intrinsic Thin-film Heterojunction Cell (HJT), Interdigitated Back Contact (IBC), Perovskite Cell, Multi Busbar Cell (MBB) and Busbarless Cell (0BB).

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

[0043] For TOPCon cells, along the thickness direction, they include a metal silver electrode, a front surface silicon nitride passivation layer, a boron-doped emitter, an N-type base silicon layer, a diffused doped layer, an ultra-thin silicon oxide, doped polysilicon, silicon nitride, and a metal silver electrode. The back of the cell is composed of an ultra-thin silicon oxide layer (1nm to 2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure that can block minority carrier-hole recombination and increase the cell's open circuit voltage and short-circuit current. The ultra-thin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking minority carrier-hole recombination. The good passivation effect of ultra-thin silicon oxide and heavily doped silicon film causes the energy band on the silicon wafer surface to bend, thereby forming a field passivation effect, greatly increasing the probability of electron tunneling and reducing contact resistance, thereby increasing the cell's open circuit voltage and short-circuit current, and further improving the cell's conversion efficiency.

[0044] For HJT batteries, along the thickness direction, they include the front low-temperature silver electrode, the front conductive film, the N-type amorphous silicon film, the intrinsic amorphous silicon film, the N-type base silicon layer, the intrinsic amorphous silicon film, the P-type amorphous silicon film, the back conductive film, and the back low-temperature silver electrode.

[0045] For IBC cells, along the thickness direction, they include silicon nitride anti-layer, N+ front surface field, N-type base silicon layer, P+ emitter, N+ back field, aluminum oxide passivation layer, silicon nitride anti-reflection layer, and metal silver electrode. IBC cells use ion implantation technology to obtain P and N regions with good uniformity and precisely controllable junction depth. There is no grid line blocking on the front of the cell, which can eliminate the shading current loss of the metal electrode and achieve the maximum utilization of incident photons. The short-circuit current 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 grid line blocking problem, so 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 to obtain a lower front surface recombination rate and surface reflection.

[0046] For perovskite cells, along the thickness direction, they include substrate material, conductive film, electron transport layer (titanium dioxide), perovskite absorption layer (hole transport layer), and metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrode with low loss, so they can generate higher photoelectric voltage and current, making perovskite show higher photoelectric conversion efficiency.

[0047] For multi-busbar cells, multiple busbars for collecting current are arranged on the surface of the cell 1211, which shortens the current conduction path in the multi-busbar cell, reduces internal losses, and thus improves the power of the multi-busbar cell. As the number of busbars increases, the cross-sectional area of ​​the busbars and the welding strips 1213 decreases, and the adhesive film layer becomes thinner, thereby reducing the production cost of the photovoltaic module 1000. As the number of busbars increases, the number of fine grids can be reduced accordingly, thereby reducing the production cost of the cell 1211.

[0048] For a busbar-free battery, there is no busbar on the surface of the battery cell 1211. After welding multiple battery cells 1211, the welding strip replaces the original busbar and directly connects to the fine grid, which can reduce the consumption of silver paste and thus reduce the production cost of the battery cell 1211. In addition, the busbar-free battery can reduce the shading area of ​​the grid line in the battery cell 1211 and reduce the transmission loss of the fine grid, thereby increasing the total power of the component. At the same time, the increase in the fine grid contact points reduces the risk of hidden cracks in thin silicon wafers and improves the yield and reliability.

[0049] The multiple cells 1211 in the battery string 1212 can be welded by lap welding technology, and two adjacent cells 1211 overlap each other, and the size of the overlapping area can be 0.2mm to 0.6mm. The overlapping area of ​​two adjacent cells 1211 is provided with a welding strip 1213, so that the two adjacent cells 1211 are connected in series to form a battery string 1212. The multiple cells 1211 in the battery string 1212 are connected in series by lap welding, which can reduce the spacing between the multiple cells 1211 in the battery string 1212, increase the area of ​​the cell 1211 in the photovoltaic module 1000, and then increase the effective light absorption area in the photovoltaic module 1000, and finally can increase the power generation power of the photovoltaic module 1000. Since two adjacent battery cells 1211 are overlapped and a welding strip 1213 is provided in the overlapping area, stress concentration is prone to occur in the overlapping area during the lamination process. Therefore, a buffer layer may be provided in the overlapping area of ​​two adjacent battery cells 1211 to reduce the possibility of hidden cracks in the battery cells 1211 during the lamination process.

[0050] The cell 1211 can be a two-piece cell, a three-piece cell, a four-piece cell, etc. This application takes a four-piece cell as an example, and divides the complete cell into four equal parts to form a four-piece cell. According to the size of the complete cell, the length of the four-piece cell can be 182.3mm, and the width can be 46.675mm to 53.25mm. After the multiple four-piece cells in the battery string 1212 are stacked, the width of the overlapping area between adjacent four-piece cells can be 0.2mm to 0.6mm, and the spacing between adjacent battery strings 1212 can be 1.2mm to 1.6mm, so that the length of the photovoltaic module 1000 can be 2278mm to 2382mm, and the width can be 1134mm. 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, thereby reducing the power loss of a single battery string 1212 and achieving power improvement of the photovoltaic module 1000.

[0051] Furthermore, the battery string layer 100 further includes a plurality of middle bus bars 140 , a plurality of edge bus bars 150 , and a plurality of jumper wires 160 .

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

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

[0054] All battery string groups 120 are provided with edge bus bars 150 at opposite ends in the second direction, each edge bus bar 150 extends along 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 of 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 portion of the jumper 160 is connected to the edge bus bar 150, and another portion is connected to an external device through a junction box. Specifically in some embodiments, the jumper 160 is formed of 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] On the contrary, if the width of the jumper 160 is less than 4 mm and the thickness is less than 0.15 mm, the cross-sectional area of ​​the jumper 160 will be small, and the current carrying capacity of the jumper 160 will be poor, and it will not be able 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 cell 1211 will increase, and during the lamination process, the jumper 160 will increase the risk of hidden cracks in the cell 1211. In particular, when the photovoltaic module 1000 is a double-glass module, since both sides of the cell 1211 are used to absorb sunlight, the excessive width of the jumper 160 will increase the shading of the cell 1211, thereby affecting the power generation efficiency.

[0057] As described in the background technology, in existing photovoltaic modules, multiple cells are connected in series through bus bars, so that the electricity generated by the cells is discharged from the bus bars. As the size of the cells increases, the current in a single cell string formed by multiple cells connected in series is larger, resulting in greater power loss in the photovoltaic module.

[0058] In order to reduce the current in a single battery string and thus reduce the power loss of photovoltaic modules, some solutions adopt a multi-slice design for large-size batteries to reduce the current in a single battery string. By first connecting in parallel and then in series, the electrical parameters of the module product are the same as those of the half-cell modules of the same size, eliminating the impact on terminal applications. However, at the same time, the number of backplane openings for the busbar lead outlets is reduced, resulting in an increase in the number of busbars at the openings. Not only does the opening diameter need to be increased, but the current transmission distance of the outer battery string is increased compared to the transmission distance of the inner battery string, thereby increasing the internal loss of the photovoltaic module. Moreover, the automatic installation of the junction box is more difficult, and the distance between the lines is smaller, which increases the risk of short circuits. In addition, due to the increase in the number of diodes in the junction box, the volume of the junction box is also increased accordingly, which is not conducive to the temperature control of the junction box.

[0059] For the above technical issues, please see Figure 2 , Figure 3 as well as Figure 4 The back panel 200 of the present application is provided with a plurality of lead-out holes 210 arranged at intervals along the first direction. One end of each intermediate bus bar 140 is connected to a group of sub-battery strings 121, and the other end of each intermediate bus bar 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 bus bar 140 adopts a split design, that is, each intermediate bus bar 140 only corresponds to connecting one group of sub-battery strings 121, compared with continuously extending an intermediate bus bar 140 to connect multiple groups of sub-battery strings 121, the length of at least part of the intermediate bus bar 140 is effectively shortened, thereby reducing the current transmission distance inside the photovoltaic module 1000, optimizing the current transmission path, and reducing the internal transmission loss of the photovoltaic module 1000, thereby effectively improving the power and power generation of the photovoltaic module 1000.

[0061] Specifically, in one embodiment, one end of each intermediate bus bar 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 , so as to be connected to an external device through a junction box.

[0062] In some embodiments, in two intermediate bus bars 140 connecting two sub-battery strings 121 of the same group, two first lead-out ends 141 extend out of the same lead-out hole 210 and are connected to each other by welding or other methods, thereby connecting the two sub-battery strings 121 in parallel. Figure 4 As shown, the distance a between the bending parts of the two first lead-out ends 141 is 0-3 mm, so that the two first lead-out ends 141 can be easily welded.

[0063] In some embodiments, the photovoltaic assembly 1000 further includes a plurality of diodes, which are accommodated 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 portion of each jumper 160 is connected to at least one battery string group 120 , and another portion of the jumper 160 extends out of the lead-out hole 210 , thereby being connected to an external device through a 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 battery string groups 120, and the first extension section 161 extends along the second direction, and both ends of the first extension section 161 are respectively connected to the edge bus bar 150 of one end of the battery string 1212 away from the middle bus bar 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 intermediate bus bars 140 and a second lead-out end 1632 of a jumper wire 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, thereby electrically connecting multiple battery strings 1212 to the diode.

[0068] As a preferred embodiment, Figure 4 As shown, in the first lead-out end 141 and the second lead-out end 1632 of the intermediate bus bar 140 led out from the same lead-out hole 210, the distance b between the intermediate bus bar 140 and the bending part of the second lead-out end 1632 is 6mm-10mm, thereby meeting the electrical safety requirements. It should be noted that the distance between the bending part of the intermediate bus bar 140 and the second lead-out end 1632 in the foregoing specifically refers to: the distance between the integral body formed by welding the first lead-out ends 141 of the two intermediate bus bars 140 and the bending part of the second lead-out end 1632.

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

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

[0071] As a preferred embodiment, the distance between one end of the second insulating segment 183 located at the lead-out hole 210 and the bending part of the first lead-out end 141 of the intermediate bus bar 140 therebelow is 0-2mm, and one end of the second insulating segment 183 located at the lead-out hole 210 protrudes from the bending part of the second lead-out end 1632 of the jumper 160, thereby preventing the second extension segment 163 of the jumper 160 and the second insulating segment 183 of the insulating strip 180 from contacting each other and causing a short circuit.

[0072] As a preferred embodiment, the insulating strip 180 has a width of 8 mm to 20 mm and a thickness of 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 and the battery cell 1211, the first extension section 161 of the jumper 160 is arranged in the center of the first insulating section 181 to reduce the possibility of short circuit caused by contact, so 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 8mm, the possibility of short circuit caused by contact between the first extension section 161 and the battery cell 1211 will increase; if the width of the first insulating section 181 is greater than 20mm, the area of ​​the overlapping region between the first insulating section 181 and the battery cell 1211 will also increase, resulting in an increase in the influence of the first insulating section 181 on the battery cell 1211 during the lamination process, especially in double-glass modules, which has a greater impact on power generation efficiency.

[0074] On the one hand, since the first insulating section 181 is located between the first extension section 161 and the battery cell 1211, if the thickness of the first insulating section 181 is greater than 0.3 mm, the thickness of the first extension section 161 and the first insulating section 181 will be too large, and the stress at the position of the first extension section 161 will be relatively large during the lamination process, which may easily lead to hidden cracks in the battery cell 1211. On the other hand, the first insulating section 181 plays an insulating role between the first extension section 161 and the battery cell 1211, and the insulation 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 insulation performance of the first insulating section 181 will be poor, which will lead to a greater possibility of a short circuit between the first extension section 161 and the battery cell 1211.

[0075] Please combine Figure 1 , Figure 2 as well as Figure 6 As shown, in one embodiment, the back plate 200 is provided with three lead-out holes 210 arranged at intervals along the first direction. Figure 1 From right to left, there are the first lead-out hole 210a, the second lead-out hole 210b, and the third lead-out hole 210c.

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

[0077] Corresponding to the six sub-battery strings 121, the battery string layer 100 includes six intermediate bus bars 140 arranged at intervals along the first direction. Figure 6 From right to left, there are the first middle bus bar 140a, the second middle bus bar 140b, the third middle bus bar 140c, the fourth middle bus bar 140d, the fifth middle bus bar 140e and the sixth middle bus bar 140f.

[0078] Among them, the first intermediate bus bar 140a and the second intermediate bus bar 140b are respectively connected to the two groups of sub-battery strings 121 of the first battery string group 120a, and 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 by the first lead-out hole 210a, and 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 the two groups of sub-battery strings 121 of the second battery string group 120b, and 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 by the second lead-out hole 210b, and 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 the two groups of sub-battery strings 121 of the third battery string group 120c, and 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 by the third lead-out hole 210c, and 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, along Figure 6 From right to left, there are the first jumper 160a and the second jumper 160b. The first extension section 161 of the first jumper 160a is located between the first battery string group 120a and the second battery string group 120b. The two 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 160a is connected to the middle position of the first extension section 161. 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 connected to the other end of the diode connected to the first middle bus bar 140a and the second middle 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, and the two 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, and the two ends of the second extension section 163 extend in opposite directions along the first direction to extend out of the second lead-out hole 210b and the third lead-out hole 210c respectively. One end of the second extension section 163 is connected to the other end of the diode connecting the third intermediate bus bar 140c and the fourth intermediate bus bar 140d, and the other end of the second extension section 163 is connected to the other end of the diode connecting the fifth intermediate bus bar 140e and the sixth intermediate bus bar 140f.

[0083] The photovoltaic assembly 1000 includes three diodes, which 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 a diode. Specifically, one end of one of the diodes is connected to the first intermediate bus bar 140a and the second intermediate bus bar 140b, and the other end is connected to the first jumper 160a. One end of one of the diodes is connected to the third intermediate bus bar 140c and the fourth intermediate bus bar 140d, and the other end is connected to one end of the second extension section 163 of the second jumper 160a. One end of one of the diodes is connected to the fifth intermediate bus bar 140e and the sixth intermediate bus bar 140f, and the other end is connected to the other end of the second extension section 163 of the second jumper 160a.

[0084] Since a three-part junction box is used to install the diode, the junction box structure 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 battery cell 1211 fails, the diode can be turned on to skip the failed battery string group 120, thereby protecting the circuit. The structure of the junction box is not limited to this, and can be set as needed to meet different installation requirements.

[0085] The photovoltaic module 1000 of the present application adopts a connection method of first parallel connection and then series connection, and the lead-out hole 210 adopts a conventional opening setting, which solves the problem of increased opening in the prior art. Since the intermediate bus bar 140 adopts a split design, the problem of different current transmission lengths of different battery strings 120 is solved, the circuit transmission path is optimized, and the internal loss is effectively reduced, thereby improving the power and power generation of the photovoltaic module 1000. In addition, the first lead-out end 141 of the intermediate bus bar 140 and the second lead-out end 1632 of the jumper 160 are arranged in the same orientation, which solves the problem of difficult installation of the junction box and effectively reduces the risk of short circuit.

[0086] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A photovoltaic module, characterized in that: The invention comprises a back plate (200) and a battery string layer (100) arranged on one side of the back plate (200), wherein the back plate (200) is provided with a plurality of lead-out holes (210) arranged at intervals along a first direction, and the battery string layer (100) comprises: A plurality of battery string groups (120) arranged at intervals along the first direction, each of the battery string groups (120) comprising two sub-battery string groups (121) arranged at intervals along the first direction, and each of the sub-battery string groups (121) comprising two battery strings (1212) arranged at intervals along the second direction; a plurality of intermediate bus bars (140), each of the intermediate bus bars (140) being located between two battery strings (1212) of the same group in the second direction, one end of each intermediate bus bar (140) correspondingly connected to one group of sub-battery strings (121), and the other end of each intermediate bus bar (140) extending out of the lead-out hole (210); The second direction is perpendicular to the first direction.

2. The photovoltaic module according to claim 1, characterized in that: One end of each of the intermediate bus bars (140) is bent along the thickness direction of the photovoltaic module to form a first lead-out end (141), and the first lead-out end (141) extends out of the lead-out hole (210).

3. The photovoltaic module according to claim 2, characterized in that: In the two intermediate bus bars (140) connecting two sub-battery strings (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.

4. The photovoltaic module according to claim 3, characterized in that: In the two intermediate bus bars (140) extending out of the same lead-out hole (210), the distance between the bends of the two first lead-out ends (141) is 0-3 mm.

5. The photovoltaic module according to claim 3, characterized in that: The photovoltaic assembly also includes a plurality of diodes, and the two first lead-out ends (141) led out from the same lead-out hole (210) are correspondingly connected to the same end of one diode.

6. The photovoltaic module according to claim 1, characterized in that: The battery string layer (100) further comprises a plurality of jumpers (160), a portion of each jumper (160) being connected to at least one group of battery string groups (120), and another portion of the jumper (160) extending out of the lead-out hole (210).

7. The photovoltaic module according to claim 6, characterized in that: Each jumper (160) comprises a first extension section (161) and a second extension section (163); two ends of the first extension section (161) are respectively connected to one end of the battery string (1212) away from the middle bus bar (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).

8. The photovoltaic module according to claim 7, characterized in that: The end of the second extension section (163) is bent along 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).

9. The photovoltaic module according to claim 8, characterized in that: In the intermediate bus bar (140) and the second lead end (1632) led out from the same lead-out hole (210), the distance between the bending parts of the intermediate bus bar (140) and the second lead end (1632) is 6 mm-10 mm.

10. The photovoltaic module according to claim 8, characterized in that: The photovoltaic component also includes a plurality of diodes, and the second lead-out end (1632) is correspondingly connected to one end of one of the diodes.

11. The photovoltaic module according to claim 7, characterized in that: The second extension section (163) and the intermediate bus bar (140) are stacked in a thickness direction of the photovoltaic component.

12. The photovoltaic module according to claim 11, characterized in that: An insulating strip (180) is provided between the second extension section (163) and the middle bus bar (140).

13. The photovoltaic module according to claim 12, characterized in that: One end portion of the insulating strip (180) protrudes from the bending portion of the second extension section (163).

14. The photovoltaic module according to any one of claims 1 to 13, characterized in that: The two battery strings (1212) in the same group respectively have a first welding strip and a second welding strip connected to the middle bus bar (140), and the first welding strip and the second welding strip are staggered in the second direction.

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