Photovoltaic module

Abstract

The utility model discloses a photovoltaic module, which comprises a photovoltaic cell, a junction box and a bus bar, and is characterized in that the photovoltaic cell comprises a plurality of cell pieces, and the adjacent cell pieces are electrically connected through a welding strip; the junction box is arranged on the side wall of the photovoltaic cell along the extension direction of the welding strip; the bus bars are distributed on the two sides of the photovoltaic cell in the extending direction of the welding strip, and at least part of the bus bars are used for being electrically connected with the welding strip and the junction box. Wherein the plurality of battery pieces are arranged along a first direction x and are connected in series to form battery strings, the plurality of battery strings are arranged along a second direction y, and two adjacent battery strings are electrically connected; therefore, according to the photovoltaic module, the junction box is installed on the side wall of the photovoltaic cell, so that the structure of the glass back plate is more complete, the strength of the glass back plate is improved, the glass back plate can bear a larger load, the structural stability of the photovoltaic cell is improved, the photovoltaic module has high mechanical strength, and the service life of the photovoltaic cell is prolonged. And the integration effect of the photovoltaic module and the building in photovoltaic building integration is further improved.

Description

Technical Field

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

[0002] Building Integrated Photovoltaic (BIPV) is a technology that integrates solar cells into buildings. Solar cells are used as components of buildings, and they play a supporting role while exerting their power generation function. Because solar cells are combined with buildings and do not occupy additional ground and building space, they can be widely used in cities. Specifically, solar cell modules can be integrated and applied in building structures such as curtain walls and skylight roofs. In the prior art, solar cells include stacked front glass, front film, battery cells, back film and back glass. In order to achieve electrical connection between multiple solar cells and between solar cells and electrical appliances, through holes for leads are usually processed on the back glass, so that the positive and negative wires of the battery cells can extend through the through holes and be electrically connected to the junction box fixed on the back glass. The method of opening holes on the back glass will not only reduce the strength of the back glass, but also increase the processing cost and difficulty of the back glass. Utility Model Content

[0003] In view of this, the present application provides a photovoltaic module to solve the technical problem of low strength of the back glass in the prior art.

[0004] The present application provides a photovoltaic module, which includes a photovoltaic cell, a junction box and a bus bar, wherein the photovoltaic cell includes a plurality of battery cells, and adjacent battery cells are electrically connected by welding strips; the junction box is installed on the side wall of the photovoltaic cell along the extension direction of the welding strip; the bus bar is distributed on both sides of the photovoltaic cell along the extension direction of the welding strip, and at least part of the bus bar is used to be electrically connected to the welding strip and the junction box; wherein, a plurality of the battery cells are arranged along a first direction x and connected in series to form a battery string, and a plurality of the battery strings are arranged along a second direction y, and two adjacent battery strings are electrically connected; one of the first direction x and the second direction y is the length direction of the photovoltaic cell, and the other is the width direction of the photovoltaic cell.

[0005] In the embodiment of the present application, the photovoltaic cell is composed of a plurality of cells connected in series and parallel by welding strips. Along the extension direction of the welding strips, both ends of the welding strips are electrically connected to the bus bars. When the junction box is installed on the side wall of the photovoltaic cell, it can be electrically connected to the welding strips through at least part of the bus bars, thereby enabling electrical connection between the junction box and the photovoltaic cell. Therefore, in the present application, by installing the junction box on the side wall of the photovoltaic cell, it is not necessary to open a through hole for the lead wire on the glass back plate of the photovoltaic cell, so that the structure of the glass back plate is more complete, which is conducive to improving the strength of the glass back plate, so that it can withstand a larger load, thereby improving the structural stability of the photovoltaic cell, and then making the photovoltaic module provided by the present application have a strong mechanical strength, so as to further improve the integration effect of the photovoltaic module with the building in the photovoltaic building integration.

[0006] For example, when the photovoltaic modules provided by the present application are used to form a photovoltaic curtain wall, the photovoltaic modules as building materials do not need to occupy precious land resources, and their strong mechanical strength can not only meet the safety performance requirements of the building, but also help to improve the working life of the photovoltaic curtain wall. In the process of assembly, the photovoltaic modules can be placed vertically, which is not only convenient for installation, but also can meet the lighting requirements of the building, and the photovoltaic effect of the photovoltaic modules can be used to effectively reduce the energy consumption of the building, achieve building energy saving, and make the photovoltaic curtain wall have a green and environmentally friendly effect. At the same time, in the process of assembly, the junction box located on the side wall of the photovoltaic cell can be hidden in the wall to meet the aesthetic requirements of the building, and the junction box installed on the side wall of the photovoltaic cell can also reduce the overall thickness of the photovoltaic module, thereby reducing the thickness of the photovoltaic curtain wall, which is conducive to improving space utilization.

[0007] Specifically, a plurality of battery cells can be arranged in a first direction x and connected in series to form a battery string, a plurality of battery strings can be arranged in a second direction y, and two adjacent battery strings can be electrically connected, or a plurality of battery cells can be arranged in a second direction y and connected in series to form a battery string, a plurality of battery strings can be arranged in a first direction x, and two adjacent battery strings can be electrically connected. Among them, one of the first direction x and the second direction y is the length direction of the photovoltaic cell, and the other is the width direction of the photovoltaic cell. When the number of battery cells is fixed, the two arrangements described above make the overall structure and size of the photovoltaic module different, so that the photovoltaic module has diversity, so as to realize the electrical connection between multiple photovoltaic modules and between the photovoltaic module and the electrical appliance in different scenarios, so as to avoid the possibility that most of the photovoltaic module is blocked during operation, resulting in low photoelectric conversion efficiency, thereby ensuring that the photovoltaic module has good working efficiency and performance.

[0008] In a possible embodiment, the junction box includes a positive junction box and a negative junction box; the battery string includes at least a first battery string and a second battery string distributed along the second direction y, and the bus bar includes at least a first bus bar extending along the second direction y, a second bus bar extending along the second direction y, and a third bus bar extending along the first direction x; the first bus bar is electrically connected to the welding strip of the first battery string, and the first bus bar is electrically connected to the positive junction box through the third bus bar, the second bus bar is electrically connected to the welding strip of the second battery string, and the second bus bar is electrically connected to the negative junction box through the third bus bar.

[0009] In a possible implementation, the positive terminal box and the negative terminal box are relatively distributed at both ends of the photovoltaic cell along the second direction y, and the positive terminal box and the negative terminal box are installed on the same side wall of the photovoltaic cell along the first direction x, or are relatively installed on two side walls of the photovoltaic cell.

[0010] In a possible implementation, the first bus bar and the third bus bar are integrally formed, or the first bus bar and the third bus bar are separately provided and fixedly connected; the second bus bar and the third bus bar are integrally formed, or the second bus bar and the third bus bar are separately provided and fixedly connected.

[0011] In a possible implementation, the battery string further includes at least one third battery string, the third battery string is located between the first battery string and the second battery string along the second direction y, and the third battery string is electrically connected to the first battery string and the second battery string respectively.

[0012] In a possible embodiment, the photovoltaic component also includes at least one diode, and along the second direction y, the diode is connected between the first battery string and the third battery string, and / or the diode is connected between the second battery string and the third battery string, and / or the diode is connected between two adjacent third battery strings.

[0013] In a possible implementation, the bus bar further includes at least one fourth bus bar, and the fourth bus bar is arranged opposite to the first bus bar, the second bus bar and the third bus bar along the first direction x, and along the second direction y, two adjacent battery strings are electrically connected through the fourth bus bar.

[0014] In a possible implementation manner, along the second direction y, the length of the fourth bus bar is L3, and L3 satisfies 348 mm≤L3≤367 mm.

[0015] In a possible implementation manner, the width of the bus bar is L1, and L1 satisfies 3mm≤L1≤4mm, and along the first direction x, the gap between the bus bar and the battery cell is L2, and L2 satisfies 3mm≤L2≤6mm.

[0016] In a possible implementation, along the first direction x, the gap between two adjacent battery cells is L4, and L4 satisfies 1.5 mm ≤ L4 ≤ 2 mm, and along the second direction y, the gap between two adjacent battery strings is L5, and L5 satisfies 2 mm ≤ L5 ≤ 20 mm.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 This is a schematic structural diagram of a photovoltaic curtain wall provided in this application in a specific embodiment;

[0020] Figure 2 for Figure 1 Circuit schematic diagram of

[0021] Figure 3 This is a schematic structural diagram of another specific embodiment of the photovoltaic curtain wall provided in this application;

[0022] Figure 4 for Figure 3 Circuit diagram of

[0023] Figure 5 for Figure 1 A partial enlarged view of the middle I area;

[0024] Figure 6 for Figure 1 A partial enlarged view of the middle II area;

[0025] Figure 7 A partial cross-sectional view of the junction box and photovoltaic module provided in this application;

[0026] Figure 8 for Figure 1 A partial enlarged view of the middle III region;

[0027] Fig. 9A partial cross-sectional view of a diode and a photovoltaic module provided in this application;

[0028] Fig.10 for Figure 1 A partial enlarged view of the middle IV region.

[0029] Description of reference numerals:

[0030] 1- Photovoltaic cells;

[0031] 11- first battery string;

[0032] 12- second battery string;

[0033] 13- the third battery string;

[0034] 14-battery cell;

[0035] 15- welding strip;

[0036] 2- Junction box;

[0037] 21- positive terminal box;

[0038] 211- positive lead;

[0039] 22-negative terminal box;

[0040] 221- negative lead;

[0041] 3-Bus bar;

[0042] 31- first bus bar;

[0043] 32- second bus bar;

[0044] 33- third bus bar;

[0045] 34- fourth bus bar;

[0046] 35-Fifth bus bar;

[0047] 4-Diode.

[0048] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0049] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0050] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0051] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0052] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0053] The embodiment of the present application provides a photovoltaic module, such as Figure 1 As shown, the photovoltaic module includes a photovoltaic cell 1, a junction box 2 and a bus bar 3. The photovoltaic cell 1 includes a plurality of cells 14, and adjacent cells 14 are electrically connected through a welding strip 15; the junction box 2 is installed on the side wall of the photovoltaic cell 1 along the extension direction of the welding strip 15; the bus bar 3 is distributed on both sides of the photovoltaic cell 1 along the extension direction of the welding strip 15, and at least part of the bus bar 3 is used to be electrically connected to the welding strip 15 and the junction box 2.

[0054] In the embodiment of the present application, the photovoltaic cell 1 is composed of a plurality of cells 14 connected in series and in parallel by welding strips 15. Along the extension direction of the welding strips 15, both ends of the welding strips 15 are electrically connected to the busbars 3. When the junction box 2 is installed on the side wall of the photovoltaic cell 1, it can be electrically connected to the welding strips 15 through at least part of the busbars 3, thereby achieving electrical connection between the junction box 2 and the photovoltaic cell 1. In the prior art, since the junction box 2 is mostly installed on the glass back plate of the photovoltaic cell 1, it is necessary to process through holes on the glass back plate of the photovoltaic cell 1 during the production process to facilitate the lead wires of the cells 14, thereby reducing the strength of the glass back plate and increasing the processing cost and difficulty of the glass back plate.

[0055] Therefore, in the present application, by installing the junction box 2 on the side wall of the photovoltaic cell 1, there is no need to open a through hole for the lead wire on the glass back panel of the photovoltaic cell 1, so that the structure of the glass back panel is more complete, which is beneficial to improve the strength of the glass back panel so that it can withstand a larger load, thereby improving the structural stability of the photovoltaic cell 1, and further making the photovoltaic module provided in the present application have strong mechanical strength, so as to further improve the integration effect of the photovoltaic module with the building in the photovoltaic building integration.

[0056] For example, when the photovoltaic modules provided by the present application are used to form a photovoltaic curtain wall, the photovoltaic modules as building materials do not need to occupy precious land resources, and their strong mechanical strength can not only meet the safety performance requirements of the building, but also help to improve the working life of the photovoltaic curtain wall. In the process of assembly, the photovoltaic modules can be placed vertically, which is not only convenient for installation, but also can meet the lighting requirements of the building. By utilizing the photoelectric effect of the photovoltaic modules, it can effectively reduce the energy consumption of the building, achieve building energy saving, and make the photovoltaic curtain wall have a green and environmentally friendly effect. At the same time, in the process of assembly, the junction box 2 located on the side wall of the photovoltaic cell 1 can be hidden in the wall to meet the aesthetic requirements of the building, and the junction box 2 installed on the side wall of the photovoltaic cell 1 can also reduce the overall thickness of the photovoltaic module, thereby reducing the thickness of the photovoltaic curtain wall, which is conducive to improving space utilization.

[0057] Specifically, Figure 1 and Figure 2 As shown, a plurality of battery cells 14 can be arranged along a first direction x and connected in series to form a battery string, a plurality of battery strings can be arranged along a second direction y, and two adjacent battery strings can be electrically connected, or, as shown Figure 3 and Figure 4 As shown, multiple battery cells 14 can also be arranged along the second direction y and connected in series to form a battery string, and multiple battery strings are arranged along the first direction x, and two adjacent battery strings are electrically connected. Among them, one of the first direction x and the second direction y is the length direction of the photovoltaic cell 1, and the other is the width direction of the photovoltaic cell 1. For example, Figure 1 As shown, the first direction x is the extension direction of the welding strip 15, and the second direction y is the arrangement direction of the battery string. Figure 3 As shown, the first direction x is the arrangement direction of the battery strings, and the second direction y is the extension direction of the welding ribbon 15 .

[0058] When the number of cells 14 is fixed, Figure 1 and Figure 3The two arrangements described above make the overall structure and size of the photovoltaic modules different, thereby making the photovoltaic modules diverse, so as to achieve electrical connection between multiple photovoltaic modules and between photovoltaic modules and electrical appliances in different scenarios, thereby avoiding the possibility that most areas of the photovoltaic modules are blocked during operation, resulting in low photoelectric conversion efficiency, thereby ensuring that the photovoltaic modules have good working efficiency and performance.

[0059] The present embodiment does not limit the structure of the solar cell 14. The types of solar cells 14 include but are not limited to Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCON), Heterojunction with Intrinsic Thin-film (HJT), Back Contact (BC), Perovskite Solar Cells (PSC), etc.

[0060] For PERC cells, along the thickness direction, PERC cells include front surface metal silver electrode, front surface silicon nitride passivation layer, phosphorus layer emitter, P-type base silicon layer, local aluminum back field, metal aluminum back electrode, back passivation layer (Al2O3 / SiNx). PERC cells use a passivation film to passivate the back, replacing the full aluminum back field, enhancing the internal back reflection of light in the silicon base, reducing the recombination rate of the back, and increasing the efficiency of photovoltaic cells 1 by 0.5%-1%.

[0061] For TOPCon cells, along the thickness direction, TOPCon cells 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 a layer of ultra-thin silicon oxide (1nm to 2nm) and a layer of phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure can block the recombination of minority carriers and holes, and improve the open circuit voltage and short circuit current of the cell. The ultra-thin oxide layer can allow majority carrier electrons to tunnel into the polysilicon layer while blocking the recombination of minority carrier holes. 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 the contact resistance, thereby improving the open circuit voltage and short circuit current of the photovoltaic cell 1, thereby improving the conversion efficiency of the photovoltaic cell 1.

[0062] For HJT cells, along the thickness direction, the HJT cells include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0063] For IBC cells, along the thickness direction, IBC cells 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 photovoltaic cell 1, which can eliminate the shading current loss of the metal electrode and realize the maximum utilization of incident photons. The short-circuit current can be increased by about 7% compared with conventional solar cells; due to the back contact structure, there is no need to consider the grid line blocking problem, and the grid line ratio can be appropriately widened, thereby reducing the series resistance and having a high fill factor; the surface passivation and surface light trapping structure can be optimized to obtain a lower front surface recombination rate and surface reflection.

[0064] For perovskite cells, along the thickness direction, the perovskite cell includes 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.

[0065] In a specific embodiment, Figure 1 , Figure 5 and Figure 6 As shown, the junction box 2 includes a positive junction box 21 and a negative junction box 22, the battery string includes at least a first battery string 11 and a second battery string 12 distributed along the second direction y, and the bus bar 3 includes at least a first bus bar 31 extending along the second direction y, a second bus bar 32 extending along the second direction y, and a third bus bar 33 extending along the first direction x; the first bus bar 31 is electrically connected to the welding strip 15 of the first battery string 11, and the first bus bar 31 is electrically connected to the positive junction box 21 through the third bus bar 33, the second bus bar 32 is electrically connected to the welding strip 15 of the second battery string 12, and the second bus bar 32 is electrically connected to the negative junction box 22 through the third bus bar 33.

[0066] In the present application embodiment, Figure 1 and Figure 2Taking the arrangement shown as an example, a plurality of battery cells 14 can be arranged along a first direction x and connected in series to form a first battery string 11 and a second battery string 12 respectively. The first battery string 11 and the second battery string 12 are arranged along a second direction y. The first battery string 11 and the second battery string 12 are electrically connected via a bus bar 3 to form a photovoltaic cell 1.

[0067] Among them, the bus bar 3 includes a first bus bar 31 extending along the second direction y and a second bus bar 32 extending along the second direction y. Since the welding strip 15 of the first battery string 11 extends along the first direction x, and the welding strip 15 of the second battery string 12 extends along the first direction x, the first bus bar 31 can be electrically connected to the welding strip 15, and the second bus bar 32 can be electrically connected to the welding strip 15, so that the first battery string 11 and the second battery string 12 are electrically connected to each other to form a photovoltaic cell 1.

[0068] At the same time, the bus bar 3 also includes a third bus bar 33 extending along the first direction x, one end of the third bus bar 33 can extend into the interior of the photovoltaic cell 1 and be electrically connected to the first bus bar 31 and the second bus bar 32, and the other end of the third bus bar 33 can extend into the positive terminal box 21 and the negative terminal box 22, so that the first bus bar 31 can be electrically connected to the positive terminal box 21 through the third bus bar 33, and the second bus bar 32 can be electrically connected to the negative terminal box 22 through the third bus bar 33, so that the photovoltaic cell 1 can be electrically connected to the positive terminal box 21 and the negative terminal box 22 through the third bus bar 33, so as to achieve electrical connection with adjacent photovoltaic components or electrical appliances through the two.

[0069] Specifically, a positive lead 211 is provided at one end of the positive electrode junction box 21, a negative lead is provided at one end of the negative electrode junction box 22, the first bus bar 31 is electrically connected to the positive lead 211 through the third bus bar 33, and the second bus bar 32 is electrically connected to the negative lead 221 through the third bus bar 33.

[0070] Therefore, in the present application, the photovoltaic cell 1 can be electrically connected to the positive terminal box 21 and the negative terminal box 22 through the third bus bar 33, thereby eliminating the need to open a through hole for the lead on the glass back panel of the photovoltaic cell 1, making the structure of the glass back panel more complete, thereby making the glass back panel have higher strength, and in the production process of the glass back panel, it is easy to achieve the direction of electrical connection between the photovoltaic cell 1 and the terminal box 2 by extending the third bus bar 33, and reducing the step of opening holes is also conducive to reducing the processing cost and difficulty of the glass back panel, which is more in line with actual production needs.

[0071] In a specific embodiment, Figure 1 , Figure 5 and Figure 6As shown, the positive terminal box 21 and the negative terminal box 22 are relatively distributed at both ends of the photovoltaic cell 1 along the second direction y, and the positive terminal box 21 and the negative terminal box 22 are installed on the same side wall of the photovoltaic cell 1 along the first direction x, or are relatively installed on two side walls of the photovoltaic cell 1.

[0072] In the embodiment of the present application, the positive terminal box 21 and the negative terminal box 22 are installed on the side wall of the photovoltaic cell 1, which can shorten the distance between the two and the third bus bar 33, and avoid the third bus bar 33 extending too long from the photovoltaic cell 1, so as to make the connection between the terminal box 2 and the photovoltaic cell 1 tighter, thereby improving the stability and reliability of the connection between the two, and then making the terminal box 2 and the photovoltaic cell 1 have a good electrical connection effect, which is conducive to improving the overall working life and performance of the photovoltaic module. At the same time, there is no need to open a through hole for the lead on the glass back plate of the photovoltaic cell 1, so that the structure of the glass back plate is more complete, so that it has a better sealing effect after the photovoltaic cell 1 is assembled, so as to further improve the photoelectric conversion efficiency of the photovoltaic module.

[0073] In a specific embodiment, Figure 5 and Figure 6 As shown, the first bus bar 31 and the third bus bar 33 are integrally formed, or the first bus bar 31 and the third bus bar 33 are separately arranged and fixedly connected; the second bus bar 32 and the third bus bar 33 are integrally formed, or the second bus bar 32 and the third bus bar 33 are separately arranged and fixedly connected.

[0074] In the embodiment of the present application, the first bus bar 31 can be integrally formed with the third bus bar 33, and the second bus bar 32 can be integrally formed with the third bus bar 33, which is beneficial to simplifying the manufacturing process of the bus bar 3 and improving the degree of integration between the first bus bar 31 and the third bus bar 33, and between the second bus bar 32 and the third bus bar 33, so that a more stable current can be transmitted during the operation of the photovoltaic module, so that the photovoltaic module can have a longer working life, or the first bus bar 31 can also be separately set and fixedly connected with the third bus bar 33, and the second bus bar 32 can also be separately set and fixedly connected with the third bus bar 33, which is beneficial to reducing the processing accuracy of the first bus bar 31, the second bus bar 32 and the third bus bar 33, and the bus bar 3 can be transported separately during transportation to reduce transportation costs.

[0075] In a specific embodiment, Figure 1 and Figure 8 As shown, the battery string further includes at least one third battery string 13, which is located between the first battery string 11 and the second battery string 12 along the second direction y, and is electrically connected to the first battery string 11 and the second battery string 12 respectively.

[0076] In the present application embodiment, Figure 1 and Figure 2 Taking the arrangement shown as an example, a plurality of battery cells 14 can also be arranged along the first direction x and connected in series to form at least one third battery string 13. Along the second direction y, at least one battery string 13 is located between the first battery string 11 and the second battery string 12. The first battery string 11 and the third battery string 13, and the third battery string 13 and the second battery string 12 are electrically connected through the bus bar 3 to form a photovoltaic cell 1. Among them, the bus bar 3 also includes a fifth bus bar 35 along the second direction y. Since the welding strip 15 of the third battery string 13 extends along the first direction x, the third bus bar 35 can be electrically connected to the welding strip 15, so that the first battery string 11, the third battery string 13 and the second battery string 12 are electrically connected to each other to form a photovoltaic cell 1. Therefore, in the present application, the photovoltaic cell 1 can be electrically connected to the first battery string 11 and the second battery string 12 through the third battery string 13 to expand the light receiving area of ​​the photovoltaic cell 1, thereby improving the photoelectric conversion efficiency of the photovoltaic module.

[0077] In another specific embodiment, there may be a plurality of third battery strings 13 , and the plurality of third battery strings 13 may be arranged along the second direction y, and two adjacent third battery strings 13 are electrically connected via a bus bar 3 .

[0078] In a specific embodiment, Figure 1 , Figure 8 and Fig. 9 As shown, the photovoltaic module also includes at least one diode 4. Along the second direction y, a diode 4 is connected between the first battery string 11 and the third battery string 13, and / or a diode 4 is connected between the second battery string 12 and the third battery string 13, and / or a diode 4 is connected between two adjacent third battery strings 13.

[0079] In the present application embodiment, Figure 1 and Figure 2Taking the arrangement shown as an example, a plurality of battery cells 14 can be arranged along the first direction x and connected in series to form a first battery string 11, a third battery string 13, and a second battery string 12, respectively. The first battery string 11, the third battery string 13, and the second battery string 12 are arranged along the second direction y, and the adjacent two are electrically connected through the bus bar 3 to form a photovoltaic cell 1. Among them, along the second direction y, a diode 4 can be connected between the first battery string 11 and the third battery string 13, between the second battery string 12 and the third battery string 13, and between two adjacent third battery strings 13, so that each battery string is connected in parallel with the diode 4, which is conducive to reducing the hot spot effect of the photovoltaic cell 1 and avoiding the possibility that the local area of ​​the photovoltaic cell 1 is blocked and the blocked area generates high heat as a load, thereby improving the working stability and service life of the photovoltaic cell 1. In addition, the diode 4 is an electronic component for unidirectional current conduction. By connecting a diode 4 in parallel to each battery string, the possibility of reverse current flow and damage to the photovoltaic cell 1 can be reduced, thereby further improving the working stability and service life of the photovoltaic module.

[0080] In a specific embodiment, Figure 1 and Fig.10 As shown, the bus bar 3 also includes at least one fourth bus bar 34, which is arranged opposite to the first bus bar 31, the second bus bar 32 and the third bus bar 33 along the first direction x, and two adjacent battery strings are electrically connected along the second direction y through the fourth bus bar 34.

[0081] In the present application embodiment, Figure 1 and Figure 2Taking the arrangement shown as an example, a plurality of battery cells 14 can be arranged along the first direction x and connected in series to form a first battery string 11, a third battery string 13 and a second battery string 12 respectively. The first battery string 11, the third battery string 13 and the second battery string 12 are arranged along the second direction y, and the adjacent two are electrically connected through the bus bar 3 to form a photovoltaic cell 1. The bus bar 3 includes a fourth bus bar 34 extending along the second direction y. Since the welding strip 15 of the first battery string 11, the welding strip 15 of the third battery string 13 and the welding strip 15 of the second battery string 12 all extend along the first direction x, the fourth bus bar 34 can be electrically connected to one end of the welding strip 15 of each battery string respectively. At the same time, the other end of each battery string is electrically connected to each other through the first bus bar 31, the second bus bar 32, the third bus bar 33 and the fifth bus bar 35 respectively, so that the adjacent two battery strings are electrically connected through the bus bar 3 to form a photovoltaic cell 1. Therefore, in the present application, the multiple cell strings within the photovoltaic cell 1 can achieve connectivity of the internal circuit of the photovoltaic cell 1 and current transmission between adjacent photovoltaic modules or electrical appliances through the first bus bar 31, the second bus bar 32, the third bus bar 33, the fourth bus bar 34 and the fifth bus bar 35, thereby ensuring the stability and reliability of the operation of the photovoltaic modules.

[0082] In a specific embodiment, Figure 1 and Fig.10 As shown, along the second direction y, the length of the fourth bus bar 34 is L3, and L3 satisfies 348 mm≤L3≤367 mm.

[0083] In the embodiment of the present application, the length L3 of the fourth bus bar 34 can specifically be 348mm, 349mm, 350mm, 351mm, 352mm, 353mm, 354mm, 355mm, 356mm, 357mm, 358mm, 359mm, 360mm, 361mm, 362mm, 363mm, 364mm, 365mm, 366mm, 367mm, etc.

[0084] When the length of the fourth bus bar 34 is too small (for example, L3 is less than 348 mm), the length of the fourth bus bar 34 is too short, so that the contact area between the fourth bus bar 34 and the welding strip 15 is small, and the electrical connection between the two is poor. During the operation of the photovoltaic module, the photovoltaic cell 1 is easily burned.

[0085] When the length of the fourth bus bar 34 is too large (for example, L3 is greater than 367 mm), the length of the fourth bus bar 34 is too long, and during the operation of the photovoltaic module, the loss of the current transmitted by the fourth bus bar 34 increases, so that the photoelectric conversion efficiency of the photovoltaic cell 1 is reduced.

[0086] Therefore, when the length of the fourth bus bar 34 satisfies 348mm≤L3≤367mm, the length of the fourth bus bar 34 is moderate, so that the contact area between the fourth bus bar 34 and the welding strip 15 of each battery string is moderate, so that during the operation of the photovoltaic module, the loss degree of the fourth bus bar 34 when transmitting current is low, which is beneficial to improve the stability and safety of the photovoltaic module during operation, thereby improving the photoelectric conversion efficiency of the photovoltaic module.

[0087] In a specific embodiment, Figure 8 As shown, the width of the bus bar 3 is L1, and L1 satisfies 3mm≤L1≤4mm. Along the first direction x, the gap between the bus bar 3 and the battery cell 14 is L2, and L2 satisfies 3mm≤L2≤6mm.

[0088] In the embodiment of the present application, the width L1 of the busbar 3 can be 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4 mm, etc.

[0089] When the width of the busbar 3 is too small (for example, L1 is less than 3 mm), the electrical connection stability between the busbar 3 and the welding strip 15 and between the busbar 3 and the junction box 2 is low, which may easily lead to poor current transmission between the photovoltaic cell 1 and the junction box 2.

[0090] When the width of the busbar 3 is too large (for example, L1 is greater than 4 mm), the area of ​​the busbar 3 is too large, which may easily lead to a higher production cost of the busbar 3 .

[0091] Therefore, when the width of the busbar 3 satisfies 3mm≤L1≤4mm, the width of the busbar 3 is moderate, which reduces the production cost while ensuring good contact between the photovoltaic cell 1 and the junction box 2, thereby ensuring the current transmission effect of the photovoltaic module during operation, which is beneficial to improving the photoelectric conversion efficiency of the photovoltaic module.

[0092] The distance L2 between the bus bar 3 and the battery cell 14 can be 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, 5mm, 5.2mm, 5.4mm, 5.6mm, 5.8mm, 6mm, etc.

[0093] When the distance between the bus bar 3 and the battery cell 14 is too small (for example, L2 is less than 3 mm), the bus bar 3 and the battery cell 14 are close to each other, so that there is a risk of short circuit during operation of the photovoltaic module, resulting in low operating stability of the photovoltaic module.

[0094] When the distance between the bus bar 3 and the battery cell 14 is too large (for example, L2 is greater than 6 mm), the bus bar 3 is far away from the battery cell 14, so that the welding ribbon 15 electrically connected to the bus bar 3 needs to have a longer length, which may cause the welding ribbon 15 to break.

[0095] Therefore, when the spacing between the bus bar 3 and the battery cell 14 satisfies 3mm≤L2≤6mm, the distance between the bus bar 3 and the battery cell 14 is moderate, avoiding the risk of breakage due to the excessive length of the welding ribbon 15. At the same time, it can also ensure that the photovoltaic module has strong reliability and safety during operation.

[0096] In a specific embodiment, Fig.10 As shown, along the first direction x, the gap between two adjacent battery sheets 14 is L4, and L4 satisfies 1.5mm≤L4≤2mm, and along the second direction y, the gap between two adjacent battery strings is L5, and L5 satisfies 2mm≤L5≤20mm.

[0097] In the embodiment of the present application, the gap L4 between two adjacent battery cells 14 can be 1.5 mm, 1.55 mm, 1.6 mm, 1.65 mm, 1.7 mm, 1.75 mm, 1.8 mm, 1.85 mm, 1.9 mm, 1.95 mm, 2 mm, etc.

[0098] When the gap between two adjacent solar cells 14 is too small (for example, L4 is less than 1.5 mm), the two adjacent solar cells 14 are close to each other, which is not conducive to heat dissipation of the solar cells 14 during the operation of the photovoltaic module.

[0099] When the gap between two adjacent cells 14 is too large (for example, L4 is greater than 2 mm), the two adjacent cells 14 are far apart, resulting in a smaller number of cells 14 inside the photovoltaic cell 1, which in turn results in a lower output power of the photovoltaic cell 1 and a lower energy density of the photovoltaic module.

[0100] Therefore, when the gap between two adjacent battery cells 14 satisfies 1.5mm≤L4≤2mm, the distance between two adjacent battery cells 14 is moderate, which not only allows each battery cell 14 inside the photovoltaic cell 1 to have a suitable heat dissipation space, but also enables the photovoltaic cell 1 to have a stable output power, thereby ensuring the overall working stability of the photovoltaic module.

[0101] The gap L5 between two adjacent battery strings can specifically be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc.

[0102] When the gap between two adjacent battery strings is too small (for example, L5 is less than 2 mm), the two adjacent battery strings are close to each other, so that there is a possibility of creepage in the photovoltaic cell 1 during operation, which makes the photovoltaic cell 1 have the risk of short circuit, thereby resulting in low working stability of the photovoltaic module.

[0103] When the gap between two adjacent cell strings is too large (for example, L5 is greater than 20 mm), the two adjacent cell strings are far apart, resulting in a smaller number of cell strings inside the photovoltaic cell 1, which in turn results in a lower output power of the photovoltaic cell 1, and further reduces the photoelectric conversion efficiency of the photovoltaic module.

[0104] Therefore, when the gap between two adjacent battery strings satisfies 2mm≤L5≤20mm, the distance between the two adjacent battery strings is moderate, which reduces the possibility of short circuit between the two adjacent battery strings and enables the photovoltaic cell 1 to have a stable output power, thereby improving the working stability and photoelectric conversion efficiency of the photovoltaic module.

[0105] The above describes in detail the structure, features and effects of the present application based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present application, but the present application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of the present application, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the protection scope of the present application.

Claims

1. A photovoltaic module, characterized in that: The photovoltaic module comprises: A photovoltaic cell (1), the photovoltaic cell (1) comprising a plurality of cell sheets (14), adjacent cell sheets (14) being electrically connected via welding strips (15); A junction box (2), the junction box (2) being mounted on a side wall of the photovoltaic cell (1) along an extension direction of the welding strip (15); A bus bar (3); the bus bar (3) is distributed on both sides of the photovoltaic cell (1) along the extension direction of the welding strip (15), and at least part of the bus bar (3) is used to be electrically connected to the welding strip (15) and the junction box (2); Wherein, a plurality of the battery cells (14) are arranged along a first direction x and connected in series to form a battery string, a plurality of the battery strings are arranged along a second direction y, and two adjacent battery strings are electrically connected; One of the first direction x and the second direction y is the length direction of the photovoltaic cell (1), and the other is the width direction of the photovoltaic cell (1).

2. The photovoltaic module according to claim 1, characterized in that: The junction box (2) comprises a positive electrode junction box (21) and a negative electrode junction box (22); The battery string at least comprises a first battery string (11) and a second battery string (12) distributed along the second direction y, and the bus bar (3) at least comprises a first bus bar (31) extending along the second direction y, a second bus bar (32) extending along the second direction y, and a third bus bar (33) extending along the first direction x; The first bus bar (31) is electrically connected to the welding strip (15) of the first battery string (11), and the first bus bar (31) is electrically connected to the positive electrode terminal box (21) through the third bus bar (33), the second bus bar (32) is electrically connected to the welding strip (15) of the second battery string (12), and the second bus bar (32) is electrically connected to the negative electrode terminal box (22) through the third bus bar (33).

3. The photovoltaic module according to claim 2, characterized in that: The positive electrode junction box (21) and the negative electrode junction box (22) are relatively distributed at two ends of the photovoltaic cell (1) along the second direction y, and the positive electrode junction box (21) and the negative electrode junction box (22) are installed on the same side wall of the photovoltaic cell (1) along the first direction x, or are relatively installed on two side walls of the photovoltaic cell (1).

4. The photovoltaic module according to claim 3, characterized in that: The first bus bar (31) and the third bus bar (33) are integrally formed, or the first bus bar (31) and the third bus bar (33) are separately arranged and fixedly connected; The second bus bar (32) and the third bus bar (33) are integrally formed, or the second bus bar (32) and the third bus bar (33) are separately arranged and fixedly connected.

5. The photovoltaic module according to claim 3, characterized in that: The battery string further comprises at least one third battery string (13), wherein the third battery string (13) is located between the first battery string (11) and the second battery string (12) along the second direction y, and the third battery string (13) is electrically connected to the first battery string (11) and the second battery string (12), respectively.

6. The photovoltaic module according to claim 5, characterized in that: The photovoltaic assembly further comprises at least one diode (4); along the second direction y, the diode (4) is connected between the first battery string (11) and the third battery string (13), and / or the diode (4) is connected between the second battery string (12) and the third battery string (13), and / or the diode (4) is connected between two adjacent third battery strings (13).

7. The photovoltaic module according to claim 3, characterized in that: The bus bar (3) further comprises at least one fourth bus bar (34), wherein the fourth bus bar (34) is arranged opposite to the first bus bar (31), the second bus bar (32) and the third bus bar (33) along the first direction x, and along the second direction y, two adjacent battery strings are electrically connected via the fourth bus bar (34).

8. The photovoltaic module according to claim 7, characterized in that: Along the second direction y, the length of the fourth bus bar (34) is L3, and L3 satisfies 348 mm ≤ L3 ≤ 367 mm.

9. The photovoltaic module according to any one of claims 1 to 8, characterized in that: The width of the bus bar (3) is L1, and L1 satisfies 3mm≤L1≤4mm; along the first direction x, the gap between the bus bar (3) and the battery cell (14) is L2, and L2 satisfies 3mm≤L2≤6mm.

10. The photovoltaic module according to any one of claims 1 to 8, characterized in that: Along the first direction x, the gap between two adjacent battery sheets (14) is L4, and L4 satisfies 1.5mm≤L4≤2mm; along the second direction y, the gap between two adjacent battery strings is L5, and L5 satisfies 2mm≤L5≤20mm.

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