photovoltaic modules

Abstract

This invention discloses a photovoltaic module, comprising: a solar panel, the solar panel including 2N+1 battery packs connected in series, each battery pack including two battery strings connected in parallel, and each battery string including a plurality of battery cells connected in series in equal numbers; wherein all battery strings are arranged parallel to the short side of the module, and each battery cell is a one-third piece cut from a whole battery cell, with the long side of the battery cell parallel to the long side of the module, where N is a positive integer. This photovoltaic module avoids damage caused by excessive current.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic module. Background Technology

[0002] With the development of photovoltaic cell module technology, the market demand for high-power modules continues to increase. In addition to the use of new cell technologies, increasing the size of the cells has gradually become a shortcut to quickly improve the power and efficiency of the modules.

[0003] In related technologies, the maximum size of solar cells has increased from the conventional side length of 157mm to a maximum side length of 210mm. However, the larger size of solar cells also poses increasing challenges to the module side. For example, the module current has increased to 1.8 times that of existing cells, which is different from existing modules and can easily impact existing systems. In addition, as the solar cells become larger, if the number of solar cells or strings of the original conventional modules is maintained, the module width will be too wide. For example, according to the existing half-cell symmetrical structure, the width of a 6-string solar cell module exceeds 1.3m, but the width of this module far exceeds the manufacturing capabilities of glass manufacturers and other raw material manufacturers on the market. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, the object of the present invention is to provide a photovoltaic module that can avoid damage caused by excessive current.

[0005] To address the aforementioned issues, the photovoltaic module provided in this embodiment of the invention includes: a solar panel, the solar panel comprising 2N+1 battery packs connected in series, each battery pack comprising two battery strings connected in parallel, each battery string comprising a plurality of battery cells connected in series and of equal number; wherein, all battery strings are arranged parallel to the short side of the module, and each battery cell is a one-third piece of a whole battery cell cut from the whole battery cell, and N is a positive integer.

[0006] According to the photovoltaic module provided in the embodiments of the present invention, the use of one-third-sized solar cells cut from a whole solar cell can reduce the internal resistance of the module and reduce the internal loss of the module. Furthermore, by connecting two adjacent cells in series and parallel to form a battery pack, the reduction in current caused by connecting the sliced ​​solar cells can be recovered. However, the output current of the module is still lower than that of the module using whole solar cells. Therefore, as the size of the solar cells increases, the present invention can not only improve the output power of the module, but also avoid the impact of excessive current on the module.

[0007] In some embodiments, the number of battery packs is five, and the number of cells in each battery string is fifteen one-third cells. For large-size cells, the module width can be reduced while ensuring the module's output power, thus simplifying the front panel manufacturing process.

[0008] In some embodiments, for the first to the 2Nth battery packs, a first bypass diode is connected in reverse parallel between any two adjacent battery packs, and a second bypass diode is connected in reverse parallel between the 2N+1th battery pack and the 2Nth battery pack. This arrangement of the battery strings in the same direction facilitates the placement of the diodes, reduces the number of bypass diodes used, and lowers costs.

[0009] In some embodiments, N first bypass diodes are disposed at a first end of the solar panel, and a second bypass diode is disposed at a second end of the solar panel, with the first end of the solar panel opposite to the second end.

[0010] In some embodiments, the second bypass diode is disposed in a junction box, and N first bypass diodes are disposed in at least one junction box, which can reduce the number of junction boxes used and reduce costs.

[0011] In some embodiments, N first bypass diodes are disposed at the first end of the solar panel; a lead busbar is led out from the negative terminal of the 2N+1th battery pack, and the second bypass diode is disposed at the first end of the solar panel through the lead busbar, thereby avoiding the junction box being on both sides, which is especially beneficial for double-sided double-glass modules, improving the bifaciality and reliability.

[0012] In some embodiments, N first bypass diodes and second bypass diodes are disposed in at least one junction box, which can reduce the number of junction boxes used and reduce costs.

[0013] In some embodiments, the overall size of the solar cell is 210 mm.

[0014] In some embodiments, the battery strings in the five battery packs are arranged parallel to the short side of the assembly to form the battery panel; wherein a first bypass diode is connected in parallel between the first and second battery packs, a first bypass diode is connected in parallel between the third and fourth battery packs, and a second bypass diode is connected in parallel between the fourth and fifth battery packs.

[0015] In some embodiments, the two first bypass diodes and the second bypass diode are respectively disposed in a junction box.

[0016] In some embodiments, the two first bypass diodes are disposed in a junction box, and the second bypass diode is disposed in a junction box.

[0017] In some embodiments, two first bypass diodes are disposed at a first end of the solar panel, and a second bypass diode is disposed at a first end of the solar panel via a lead busbar; the two first bypass diodes and the second bypass diode are disposed in at least one junction box.

[0018] In some embodiments, at least one bypass diode is connected to a common junction box via an edge busbar. The edge busbars have overlapping areas, and an insulating strip is provided between the edge busbars in the overlapping areas. The insulating strip at least covers the overlapping areas to avoid short circuits, leakage, and other issues.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 This is a schematic diagram of a photovoltaic module according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of a solar panel with a junction box in a photovoltaic module according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of a solar panel with a junction box in a photovoltaic module according to another embodiment of the present invention.

[0024] Figure label:

[0025] 10. Solar panel; 1. Battery pack; 2. Battery string; 3. Solar cell; 4. First bypass diode; 5. Second bypass diode; 6. Junction box; 7. Lead busbar. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0027] To address the aforementioned problems, a photovoltaic module according to an embodiment of the present invention is described below with reference to the accompanying drawings. This photovoltaic module can prevent damage caused by excessive current.

[0028] Figure 1 The diagram shown is a schematic diagram of a photovoltaic module provided in an embodiment of the present invention. Figure 1As shown, the photovoltaic module includes a solar panel 10, which includes 2N+1 battery packs 1 connected in series. Each battery pack 1 includes two battery strings 2 connected in parallel. Each battery string 2 includes multiple battery cells 3 connected in series in equal numbers. The battery strings 2 are arranged parallel to the short side of the photovoltaic module. The battery cells 3 are one-third of the battery cells cut from the whole battery cell. N is a positive integer.

[0029] In this embodiment of the invention, the photovoltaic module uses one-third of a solar cell. Compared to using a whole solar cell, this reduces the internal losses of the photovoltaic module. Furthermore, using two cells in parallel avoids the voltage drop caused by using one-third of a solar cell, thus ensuring the output power of the photovoltaic module. This means that even with increased cell size, the module power can still be increased. Moreover, using one-third of a solar cell reduces the output current of each cell string. The parallel connection of the cell strings restores the reduced current caused by the one-third cell connection, but the module output current remains lower than that of a module using a whole solar cell connection. Therefore, while increasing cell size and module power, this embodiment of the invention can reduce the current of the photovoltaic module without significantly increasing it, thus avoiding damage to the photovoltaic module due to excessive current.

[0030] In the embodiment, regarding the laying direction of the battery string 2, in the symmetrical structure circuit assembly, the battery string is laid parallel to the long side of the assembly. However, in the photovoltaic module of this embodiment, as... Figure 1 As shown, all battery strings 2 are placed parallel to the short side of the module, and the long side of one-third of the battery cells 3 is parallel to the long side of the module, i.e., arranged in a horizontal manner. Therefore, the solar panel 10 no longer needs to be arranged in two symmetrical parts, making the circuit connection simpler. Moreover, if the number of battery cells or battery strings of the original conventional module is still maintained, the present invention can reduce the width of the module while ensuring that the photovoltaic module power is competitive, thereby solving the problem of the inability to supply raw materials such as glass. At the same time, since all battery strings 2 are arranged parallel in the same direction, the complex jumper wiring can be reduced, which helps to simplify the module manufacturing process.

[0031] It should be noted that the number of battery packs 1 in the photovoltaic module provided by the present invention can be adjusted according to the number of battery cells 3 or the width of the module, depending on the specific circumstances, and there is no limitation thereto.

[0032] According to the photovoltaic module provided in the embodiments of the present invention, a three-in-two circuit processing method is used, that is, one-third of a single cell 3 is cut from a whole cell to reduce the internal resistance and internal loss of the module. Adjacent cell strings 2 are connected in parallel to form a cell pack 1. Compared with a whole cell module circuit, the output current of each cell string 2 is reduced. By connecting two cell strings 2 in parallel, the current reduction caused by connecting one-third cells can be recovered. However, the module output current is still lower than that of a module using whole cells. Thus, while increasing the module power by increasing the cell size, the increase in module current is reduced, and excessive current is avoided from impacting the module. Furthermore, by arranging all cell strings parallel to the short side of the module, i.e., using a horizontal arrangement, the circuit connection is simpler than a top-to-bottom symmetrical arrangement, which simplifies the module manufacturing process. Moreover, while ensuring the competitive power of the photovoltaic module, the module width can be reduced, solving the problem of insufficient supply of raw materials such as glass.

[0033] Furthermore, a bypass diode 4 is provided in the solar panel 10 to bypass the battery string 2 when it is shaded, thus preventing overheating and damage to the components. Specifically, for the first to the 2Nth battery string 1, a first bypass diode 4 is connected in reverse parallel between any two adjacent battery strings 1, and a second bypass diode 5 is connected in reverse parallel between the 2N+1th battery string 1 and the 2Nth battery string 1. Since the battery strings 2 are laid in the same direction, it is beneficial to set up the bypass diodes, which can reduce the number of bypass diodes used and reduce costs.

[0034] For example, such as Figure 1 As shown, N=2, meaning the photovoltaic module includes five battery packs 1. Specifically, when the entire photovoltaic module consists of 50 whole cells, the whole cell with a side length of 210mm is divided into three parts using laser scribing. Each battery string 2 includes 15 cells connected in series to form one-third of the battery cells 3, forming a total of 10 battery strings 2. The battery strings 2 are laid parallel to the short side of the photovoltaic module, i.e., arranged in a horizontal manner, and adjacent battery strings 2 are in parallel, thus forming five parallel structures, i.e., five battery packs 1. The five battery packs 1 are then connected in series. Among the first to fourth battery packs 1, a first bypass diode 4 is connected in reverse parallel between adjacent battery packs 1, and a second bypass diode 5 is connected in reverse parallel between the fifth battery pack 1 and the fourth battery pack 1, thus forming a circuit board 10 for a 50-pcs 210mm large silicon wafer photovoltaic module.

[0035] In this embodiment, since conventional diodes are limited by their reverse withstand voltage capability, the maximum number of battery cells they can protect is no more than 24. The number of battery cells 3 in each battery string 2 needs to be matched according to the bypass diode to avoid the voltage being too high due to too many battery cells 3 in the battery string 2, which would lead to the risk of breakdown of the bypass diode. For example, the number of battery cells 3 in each battery string 2 can be set to fifteen one-third battery cells, so that when two adjacent battery strings 2 are connected in parallel, the number of battery cells 3 protected by a single bypass diode does not exceed 24, thus avoiding the problem of reverse breakdown of the bypass diode.

[0036] In this embodiment, a bypass diode is disposed inside junction box 6.

[0037] Specifically, such as Figure 2 As shown, N first bypass diodes 4 are disposed at the first end of the solar panel 10, and second bypass diodes 5 are disposed at the second end of the solar panel 10, with the first end and the second end of the solar panel 10 facing each other. In this case, the second bypass diodes 5 can be disposed in a junction box 6. When N first bypass diodes 4 are disposed in at least one junction box 6, that is, when there are bypass diodes on both sides of the solar panel 10, the second bypass diodes 5 at the second end of the solar panel 10 need to be disposed in a separate single junction box 6, while the multiple first bypass diodes 4 at the first end of the solar panel 10 can be disposed in all or part of the junction box 6, which can reduce the number of junction boxes 6 used and reduce costs.

[0038] Or, such as Figure 3 As shown, N first bypass diodes 4 are disposed at the first end of the solar panel 10; a lead bus bar 7 is led out from the negative terminal of the 2N+1th battery pack 1, and the second bypass diode 5 is disposed at the first end of the solar panel 10 through the lead bus bar 7. That is, the second bypass diode 5 at the second end of the solar panel 10 can be moved to the first end of the solar panel 10 by means of a negative jumper, so that the N first bypass diodes 4 and the second bypass diode 5 are all located on the same side of the solar panel 10, which is beneficial to reduce the space occupied by the photovoltaic module. At this time, the N first bypass diodes 4 and the second bypass diode 5 are disposed in at least one junction box 6, which can reduce the number of junction boxes 6 used and reduce costs.

[0039] Furthermore, in the module circuit, since there is a partial overlap between the jumper wire and the solar cell, an insulating layer is provided at least in the overlap area when setting the lead busbar 7 to avoid short circuits, leakage, etc. It is understood that, for ease of fabrication, the insulating layer can also be provided in the surrounding area, or other methods that can achieve insulation between the jumper wire and the solar cell. This embodiment does not specifically limit this, as long as it does not affect the normal operation of the photovoltaic module. The insulating layer can be a reflective film, which can achieve both insulation and light reflection, thus improving the performance of the photovoltaic module. At the same time, while achieving insulation, the thickness of the insulating layer should be minimized to avoid lamination cracking.

[0040] For bifacial double-glass modules, shading on the back of the module can lead to a decrease in back-side power and even reliability issues such as hot spots. If the junction box 6 is located on both sides of the module's long side, sufficient space needs to be reserved for the junction box 6 to avoid obstructing the back of the solar cells 3, resulting in a wider module and indirectly reducing module efficiency. Therefore, the circuit connection method of placing the bypass diodes on the first side of the solar panel 10 is more suitable for bifacial double-glass modules, avoiding the problem of reduced module efficiency and improving bifaciality and reliability.

[0041] The arrangement of the junction box 6 in the photovoltaic module of the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] In this embodiment, the entire battery cell has a size of 210mm. The present invention divides the 210mm side-length battery cell into three parts using laser scribing, i.e., using one-third of the battery cell. Figure 1 As shown, there are five battery packs 1, adjacent battery packs 1 are connected in series, and two adjacent battery strings 2 are connected in parallel, for a total of 14 battery strings 2. Each battery string 2 uses 15 one-third battery cells 3. In the five battery packs 1, the battery strings 2 are arranged parallel to the short side of the module to form a solar panel 10.

[0043] In an embodiment, such as Figure 1 As shown, a first bypass diode 4 is connected in parallel between the first battery pack 1 and the second battery pack 1, a first bypass diode 4 is connected in parallel between the third battery pack 1 and the fourth battery pack 1, and a second bypass diode 5 is connected in parallel between the fourth battery pack 1 and the fifth battery pack 1. Therefore, in the entire photovoltaic module, a total of two first bypass diodes 4 and one second bypass diode 5 are provided.

[0044] Furthermore, when setting up junction box 6, two first bypass diodes 4 and one second bypass diode 5 can be respectively installed in one junction box 6, such as... Figure 2As shown, the corresponding junction box 6 is configured as three individual junction boxes. Two junction boxes 6, each containing a separate first bypass diode 4, are located at the first end of the solar panel 10. A junction box 6, containing a separate second bypass diode 5, is located at the second end of the solar panel 10. Alternatively, the two first bypass diodes 4 are housed in one junction box 6, and the second bypass diode 5 is housed in a separate junction box 6. In other words, the two first bypass diodes 4 are connected by a circuit and integrated into one junction box 6, while the junction box 6 at the second end of the solar panel 10 remains a single-diode junction box, containing the second bypass diode 5.

[0045] Alternatively, in an embodiment, such as Figure 3 As shown, two first bypass diodes 4 are disposed at the first end of the solar panel 10, and a second bypass diode 5 is disposed at the first end of the solar panel 10 via a lead busbar 7. In this case, the two first bypass diodes 4 and the second bypass diode 5 can be disposed in at least one junction box 6. Specifically, as shown... Figure 3 As shown, this invention moves the second bypass diode 5 from the second end of the solar panel 10 to the first end of the solar panel 10 via a lead busbar 7, thereby placing all three bypass diodes on the same side of the solar panel 10. Therefore, all or some of the bypass diodes can be placed in the same junction box 6, meaning three or more can be placed in one junction box 6. For example, all three bypass diodes can be placed in the same junction box 6, or... Figure 3 The four bypass diodes can be individually installed in junction box 6, or any two adjacent bypass diodes can be integrated into one junction box, and the other bypass diode can be installed in a separate junction box 6. There are no specific restrictions on this installation method.

[0046] It should be noted that, when each bypass diode is individually installed in the junction box 6, the circuit connection method of the battery board 10 is relatively simpler compared to other junction box 6 installation methods.

[0047] In this embodiment, when at least one bypass diode is connected to the common junction box 6 via an edge busbar, the edge busbars have overlapping areas. Insulating strips are provided between the edge busbars in the overlapping areas, and the insulating strips at least cover the overlapping areas. Specifically, in this invention, when some bypass diodes are integrated into the same junction box 6, the edge busbars need to be extended at their overlapping points. This results in overlap between the edge busbars, and insulating strips are required at these overlap points for insulation treatment to avoid electrical connection problems caused by direct contact at the overlap points, ensuring the normal operation of the photovoltaic module. It is understood that, for ease of fabrication, insulating strips can also be simultaneously provided in the surrounding area. This embodiment does not specifically limit this, as long as it does not affect the normal operation of the photovoltaic module.

[0048] Furthermore, the edge busbar may include a central conductor and an outer insulating layer surrounding the central conductor. It should be noted that when the edge busbar with this structure comes into contact with other conductor structures, the outer insulating layer provides insulation, eliminating the need for an additional insulating layer and simplifying the photovoltaic module structure and manufacturing process.

[0049] In summary, the photovoltaic module according to embodiments of the present invention uses one-third of a solar cell 3, with all cell strings 2 arranged parallel to the short side of the module. The long side of the one-third solar cell 3 is parallel to the long side of the module, i.e., a horizontal arrangement. Compared to a symmetrical arrangement of two parts, the circuit connection is simpler, reducing complex jumper wiring and insulation processes, thereby simplifying the module manufacturing process and increasing production capacity. Furthermore, compared to a module circuit using a single solar cell, the three-in-two parallel circuit processing method—using one-third of the solar cell 3 and connecting the cell strings 2 in parallel—reduces the increase in module current, especially for 50 cells. The design of the 210mm battery, through the circuit connection method of the photovoltaic module of this invention, reduces the original 1.8 times current of the battery to 0.6 times by a three-way split, and then restores it to 1.2 times by a parallel circuit, making it close to the current of the module corresponding to the existing 166mm battery, and the module power can reach more than 460W, which is higher than the module power corresponding to the 166mm battery. This avoids the impact on the module caused by excessive current, and can reduce the module width as much as possible while ensuring the module power is competitive, so as to solve the problem of unavailable raw materials such as glass.

[0050] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0051] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A photovoltaic module, characterized by, The battery panel comprises 2N+1 battery groups connected in series, each of the battery groups comprises two battery strings connected in parallel, each of the battery strings comprises a plurality of battery pieces connected in series and equal in number, and N is a positive integer. All of the battery strings are arranged in parallel with the short side direction of the module, the battery pieces are one-third battery pieces cut from whole battery pieces, the number of the battery groups is five, the number of the battery pieces in each of the battery strings is fifteen one-third battery pieces, and the size of the whole battery piece is 210mm. A first bypass diode is connected in anti-parallel between every two adjacent battery groups from the first battery group to the 2Nth battery group, and a second bypass diode is connected in anti-parallel between the 2N+1th battery group and the 2Nth battery group. N first bypass diodes are arranged at the first end of the battery panel, the second bypass diode is arranged at the second end of the battery panel, the first end and the second end of the battery panel are opposite to each other, the second bypass diode is arranged in a junction box, and N first bypass diodes are arranged in at least one junction box. Alternatively, N first bypass diodes are arranged at the first end of the battery panel, a lead busbar is led out from the negative terminal of the 2N+1th battery group, the second bypass diode is arranged at the first end of the battery panel through the lead busbar, and N first bypass diodes and the second bypass diode are arranged in at least one junction box.

2. The photovoltaic module according to claim 1, wherein the battery strings in the five battery groups are arranged in parallel with the short side direction of the module to form the battery panel. A first bypass diode is connected in parallel between the first battery group and the second battery group, a first bypass diode is connected in parallel between the third battery group and the fourth battery group, and a second bypass diode is connected in parallel between the fourth battery group and the fifth battery group.

3. The photovoltaic module according to claim 2, wherein the two first bypass diodes and the second bypass diode are arranged in a junction box respectively.

4. The photovoltaic module according to claim 2, wherein the two first bypass diodes are arranged in a junction box, and the second bypass diode is arranged in a junction box.

5. The photovoltaic module according to claim 2, wherein the two first bypass diodes are arranged at the first end of the battery panel, and the second bypass diode is arranged at the first end of the battery panel through a lead busbar. The two first bypass diodes and the second bypass diode are arranged in at least one junction box. At least one bypass diode is connected to a common junction box through an edge busbar, an overlapping area exists between the edge busbars, an insulation strip is arranged between the edge busbars in the overlapping area, and the insulation strip covers at least the overlapping area. ​ ​ ​ ​ 6. The photovoltaic module according to any of claims 1 or 4 or 5, characterized in that, ​

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