A photovoltaic module

Abstract

The application relates to a photovoltaic module, which comprises power generation units and bypass diodes; the power generation units are arranged in multiple groups, and the multiple groups of power generation units are connected in series through bus bars respectively; each power generation unit comprises multiple cell strings connected in parallel, and each cell string comprises multiple slice cells connected in series; the slice cells are 1 / R slices of whole cells, and R>=2; each power generation unit is provided with one bypass diode in parallel; the number of slice cells corresponding to each bypass diode is unevenly arranged, and the number of slice cells in the cell string of the power generation unit located at the edge of the photovoltaic module is less than that of the power generation unit located at the middle position. In the application, the number of slice cells corresponding to each bypass diode is unevenly arranged, so that the cell string of the power generation unit located at the upper edge of the module meets the reliability of hot spots, the temperature of the cell hot spots at the lower edge of the module is reduced, and the reliability of the module is improved.

Description

Technical Field

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

[0002] Currently, the mainstream half-cell module 10 uses 1 / 2-cell cells, dividing the module into two symmetrical regions, namely the first region 11 and the second region 12. Cells 51 within each region are connected in series to form a cell string 50. The two regions are connected in parallel and share three bypass diodes, namely D1, D2, and D3. Figure 1 As shown, it is a circuit diagram of a conventional half-chip component.

[0003] The aforementioned half-cell module adopts a symmetrical module form, with each cell string containing an equal number of cell slices. Under the same shading conditions, when hot spots occur in all cell slices, the temperature rise range is equal, and the hot spot risk corresponds to each cell slice equally. When a cell slice develops a hot spot, one-third of the cell slices in the entire module will be short-circuited, resulting in a one-third power loss. When cell slices in the cell strings served by the two bypass diodes are both shaded, it will cause a two-thirds power loss, and so on.

[0004] However, in the actual use of photovoltaic modules, whether it is shading caused by external shadows or shading caused by dust accumulation on the surface of the photovoltaic module, it often occurs at the bottom edge of the photovoltaic module. In other words, the probability of hot spots being generated at the bottom edge of the module is higher than that at the top edge. This means that the existing design scheme of evenly distributing hot spot temperature rise is not compatible with the actual application environment, resulting in more power loss and reduced module reliability.

[0005] Therefore, it is necessary to design a photovoltaic module to solve the above-mentioned technical problems. Utility Model Content

[0006] Based on this, this application provides a photovoltaic module that, while ensuring the hot spot reliability of the cell strings at the upper edge of the module, can reduce the hot spot temperature of the cells at the lower edge of the module, thereby improving the module's reliability and avoiding excessive power loss.

[0007] To address the above issues, this application provides a photovoltaic module, comprising: a power generation unit and a bypass diode; the power generation unit is configured as a plurality of units, which are connected in series via busbars; each power generation unit includes a plurality of parallel-connected cell strings, each cell string comprising a plurality of sequentially connected sliced ​​cells, each sliced ​​cell being a 1 / R slice of a whole cell, where R≥2; each power generation unit also corresponds to a bypass diode connected in parallel; wherein the number of sliced ​​cells corresponding to each bypass diode is not evenly distributed, with the number of sliced ​​cells in the cell strings of the power generation units located at the edge of the photovoltaic module being less than the number of sliced ​​cells in the cell strings of the power generation units located in the middle position.

[0008] A preferred embodiment is that the photovoltaic module contains at least three power generation units, namely a first power generation unit, a second power generation unit, and a third power generation unit; the second power generation unit and the third power generation unit are arranged side by side, and the first power generation unit is located below the second power generation unit and the third power generation unit; the number of sliced ​​cells in the battery string of the first power generation unit is less than the number of sliced ​​cells in the battery string of the second power generation unit and the third power generation unit.

[0009] A preferred embodiment is that the busbar includes a first busbar and a second busbar; the first power generation unit and the second power generation unit are connected in series via the first busbar; and the first power generation unit and the third power generation unit are connected in series via the second busbar.

[0010] A preferred embodiment is that the bypass diode includes a first bypass diode; the first bypass diode is connected to the first busbar and the second busbar; the first bypass diode is connected in parallel with the first power generation unit through the first busbar and the second busbar.

[0011] A preferred embodiment is that the busbar further includes a second bypass busbar, and the bypass diode further includes a second bypass diode; the second bypass busbar is connected to the first busbar; and the second bypass diode is connected in parallel with the second power generation unit through the second bypass busbar.

[0012] A preferred embodiment is that the busbar further includes a third bypass busbar, and the bypass diode further includes a third bypass diode; the third bypass busbar is connected to the second busbar; and the third bypass diode is connected in parallel with the third power generation unit through the third bypass busbar.

[0013] A preferred embodiment is that the photovoltaic module contains at least three power generation units, namely a first power generation unit, a second power generation unit, and a third power generation unit, which are arranged sequentially from top to bottom; the number of sliced ​​cells in the battery string in the first power generation unit and the third power generation unit is equal and less than the number of sliced ​​cells in the battery string in the second power generation unit.

[0014] A preferred embodiment is that the photovoltaic module contains at least three power generation units, namely a first power generation unit, a second power generation unit, and a third power generation unit, which are arranged sequentially from top to bottom; the number of sliced ​​cells in the battery string of the third power generation unit is less than the number of sliced ​​cells in the battery string of the second power generation unit, and is also less than the number of sliced ​​cells in the battery string of the first power generation unit.

[0015] A preferred embodiment is that the busbar includes a first busbar and a second busbar; the first power generation unit and the second power generation unit are connected in series via the first busbar; and the second power generation unit and the third power generation unit are connected in series via the second busbar.

[0016] A preferred embodiment is that the busbar includes a first bypass busbar, and the bypass diode includes a first bypass diode; the first bypass busbar is connected to the first busbar; and the first bypass diode is connected in parallel with the first power generation unit through the first bypass busbar.

[0017] A preferred embodiment is that the busbar further includes a second bypass busbar, and the bypass diode further includes a second bypass diode; the second bypass busbar connects the first busbar and the second busbar; the second bypass diode is connected in parallel with the second power generation unit through the second bypass busbar.

[0018] A preferred embodiment is that the busbar further includes a third bypass busbar, and the bypass diode further includes a third bypass diode; the third bypass busbar is connected to the second busbar; and the third bypass diode is connected in parallel with the third power generation unit through the third bypass busbar.

[0019] This application has at least the following beneficial effects:

[0020] Compared with the prior art, the photovoltaic module provided in this application is a multi-slice and multi-parallel form. Since each slice cell is a 1 / R slice of the whole cell, where R≥2, and multiple power generation units are set, and each power generation unit is also connected in parallel with a bypass diode, the number of slice cells corresponding to each bypass diode is not evenly distributed. That is, for each bypass diode, the number of slice cells is not equally distributed. The number of slice cells in the cell string of the power generation unit located at the edge of the module is less than the number of slice cells in the cell string of the power generation unit located in the middle of the module. Since the temperature of a hot spot is positively correlated with the magnitude of the reverse bias voltage experienced by the cell slice when the hot spot occurs, i.e., positively correlated with the number of cell slices connected in parallel to each bypass diode, and since the probability of a hot spot occurring at the lower edge of the module is higher than at the upper edge, the number of cell slices in the cell strings at the lower edge of the module is adjusted to be less than the number of cell slices in the cell strings at the upper edge of the module, without increasing the number of bypass diodes or ensuring that the cell strings at the upper edge of the module meet the hot spot reliability requirements. In this way, when the cell slices at the lower edge of the module are obstructed, the non-equal distribution of the number of cell slices can reduce the hot spot temperature of the cells at the lower edge of the module, thereby reducing heat generation and improving module reliability, while also increasing power generation compared to existing half-cell modules and avoiding greater power loss. Attached Figure Description

[0021] Figure 1 This is a circuit diagram of a half-cell component in the prior art;

[0022] Figure 2 This is a schematic diagram of outdoor installation of photovoltaic modules in existing technology;

[0023] Figure 3 A schematic diagram of the circuit of a photovoltaic module before adjustment in the existing technology. Figure 1 ;

[0024] Figure 4 In this embodiment one Figure 3 A circuit diagram of the photovoltaic module after adjustments based on the existing circuit.

[0025] Figure 5 A schematic diagram of the circuit of a photovoltaic module before adjustment in the existing technology. Figure 2 ;

[0026] Figure 6 In this second embodiment, Figure 5 Circuit diagram of photovoltaic modules after adjustment. Figure 1 ;

[0027] Figure 7 In this second embodiment, Figure 5Circuit diagram of photovoltaic modules after adjustment. Figure 2 .

[0028] Figure label:

[0029] 10. Half-cell module; 11. First region; 12. Second region; 20. Power generation unit; 21. First power generation unit; 22. Second power generation unit; 23. Third power generation unit; 31. First bypass diode; 32. Second bypass diode; 33. Third bypass diode; 41. First busbar; 42. Second busbar; 43. First bypass busbar; 44. Second bypass busbar; 45. Third bypass busbar; 46. Head busbar; 47. Tail busbar; 50. Battery string; 51. Sliced ​​battery. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0031] A bypass diode is a diode connected in reverse parallel across the two ends of a cell string in a photovoltaic module. It effectively prevents the cells in the string from burning out due to hot spot effects and is an important component of photovoltaic modules. Bypass diodes prevent cells from being partially shaded under strong sunlight, thus preventing some areas from becoming loads due to lack of sunlight, causing severe overheating and damage.

[0032] Specifically, in a series circuit of a photovoltaic (PV) module, a shaded cell will act as a load, consuming the energy generated by other illuminated cells. The shaded cell will then heat up, a phenomenon known as the hot spot effect. This effect can severely damage PV modules, causing some of the energy generated by the illuminated cells to be consumed by the shaded cells. Therefore, when a cell exhibits a hot spot effect and cannot generate electricity, a bypass diode acts as a bypass, allowing the current generated by other cells to flow through the diode, enabling the PV module to continue generating electricity and preventing a complete power outage due to a single cell malfunction.

[0033] When bypass diodes are connected in parallel at both ends of the cell string, the bypass diodes activate, bypassing the area corresponding to the shaded cell string. This ensures the photovoltaic module functions normally and protects the shaded cells from damage. However, even with this bypass, the uncovered cells in the bypassed area cannot generate electricity, resulting in a loss.

[0034] Currently, the mainstream half-cell module 10 uses 1 / 2-cell cells, dividing the module into two symmetrical regions, namely the first region 11 and the second region 12. Cells 51 within each region are connected in series to form a cell string 50. The two regions are connected in parallel and share three bypass diodes, namely D1, D2, and D3. Figure 1 As shown, it is a circuit diagram of a conventional half-chip component.

[0035] Under the same shading conditions, the temperature rise range is equal for all cell slices of this type of half-cell module when hot spots occur, and the risk of hot spots is also equal for each cell slice. However, the following problems still exist in the practical application of this type of half-cell module: Figure 2 The diagram shows an outdoor installation of photovoltaic (PV) modules. Outdoor PV modules are mostly vertically mounted. As dust accumulates, it flows from the top edge to the bottom edge of the module under the influence of gravity, rain, dew, and wind. The lower half of the module is more easily blocked by dust than the upper half. Furthermore, when the sun's angle of incidence is low, the front-row modules can block the bottom edge of the rear-row modules. Additionally, weeds on the ground can also easily block the bottom edge of the modules. In short, when used outdoors, the probability of hot spots forming on the bottom edge of the module is higher than on the top edge. This means that the existing design for evenly distributing hot spot temperature rise in PV modules is not compatible with the application environment, resulting in power loss and reduced module reliability.

[0036] Therefore, based on the above, this application provides a photovoltaic module in which, without adding bypass diodes, the number of sliced ​​cells for each bypass diode is not equally distributed. While ensuring that the cell strings at the upper edge of the module meet the hot spot reliability requirements, the number of sliced ​​cells in the cell strings at the lower edge of the module is adjusted to be less than the number of sliced ​​cells in the cell strings at the upper edge of the module. This can reduce the hot spot temperature of the cells at the lower edge of the module, thereby improving the reliability of the module and avoiding more power loss.

[0037] Example 1

[0038] The following describes in detail a photovoltaic module provided in this embodiment with reference to the accompanying drawings. Figure 4For example, a photovoltaic module includes: a power generation unit 20 and a bypass diode. Multiple power generation units 20 are configured, and these units are connected in series via busbars. Each power generation unit 20 includes multiple parallel-connected battery strings 50, each battery string 50 including multiple sequentially connected sliced ​​batteries 51. Each sliced ​​battery 51 is a 1 / R slice of a complete battery cell, where R≥2. Each power generation unit 20 also has a corresponding parallel-connected bypass diode. The number of sliced ​​batteries 51 corresponding to each bypass diode is not evenly distributed; the number of sliced ​​batteries 51 in the battery strings 50 of the power generation units 20 located at the edge of the photovoltaic module is less than the number of sliced ​​batteries 51 in the battery strings 50 of the power generation units 20 located in the middle.

[0039] The photovoltaic module provided in this embodiment is a multi-slice, multi-parallel configuration. Each slice cell 51 is a 1 / R slice of the entire cell. The hot spot temperature is positively correlated with the reverse bias voltage experienced by the slice cell 51 when a hot spot occurs, i.e., positively correlated with the number of slice cells 51 connected in parallel to each bypass diode. Without increasing the number of bypass diodes, the slice cells 51 are designed with a non-equal number for each bypass diode. While ensuring that the cell strings 50 in the middle of the module meet the hot spot reliability requirements, the number of slice cells 51 in the cell strings 50 at the edge of the module is adjusted to be less than the number of slice cells 51 in the cell strings 50 in the middle position. This reduces the hot spot temperature of the cells at the edge of the module when shading occurs, thereby improving the reliability of the module and maximizing the output of the photovoltaic module when shading occurs. Output power; specifically, the number of sliced ​​cells 51 in the battery string 50 of the power generation unit 20 located at the edge of the photovoltaic module is adjusted to be less than the number of sliced ​​cells 51 in the battery string 50 of the power generation unit 20 at other positions. That is, the number of sliced ​​cells 51 connected in parallel with the bypass diodes corresponding to the power generation unit 20 located at the edge of the module is less than the number of sliced ​​cells 51 connected in parallel with the bypass diodes corresponding to the power generation unit 20 at other positions of the module, such as the middle position. When a single module or module array at the lower or upper edge of the module is shaded, compared with the half-cell module 10 in the prior art, the area of ​​the cells that stop working is reduced, the output power of the photovoltaic module is maintained to the maximum extent when shading occurs, and the hot spot temperature of the cells at the edge of the module is also reduced, thereby improving the reliability of the module. Compared with the half-cell module 10 or other multi-cut multi-parallel modules in the prior art, this method in this embodiment does not increase the number of bypass diodes. Instead, it adopts a non-equal number of sliced ​​cells 51 for each bypass diode while maintaining the same number of bypass diodes.

[0040] In this embodiment, it should be noted that the sliced ​​battery 51 is a 1 / R slice of the whole battery, where R≥2. Preferably, the sliced ​​battery 51 is a 1 / 3 slice, but it can also be a 1 / 2, 1 / 4, 1 / 5, or 1 / 6 slice, or other battery sizes. With more cuts, it often has a significant output power advantage when the obstructed area is relatively small, and can effectively reduce power loss caused by battery obstruction. Each battery string 50 includes several sliced ​​batteries 51 connected in series. Specifically, the positive terminal of each sliced ​​battery 51 is electrically connected to the negative terminal of the previous sliced ​​battery 51, or the negative terminal of each sliced ​​battery 51 is electrically connected to the positive terminal of the previous sliced ​​battery 51. In each battery string 50, the sliced ​​batteries 51 are connected in series by conductive tape or metal interconnecting strips. Specifically, the positive terminal of each slice battery 51 is connected to the negative terminal of the previous slice battery 51 by conductive tape or metal interconnection strip, or the negative terminal of each slice battery 51 is connected to the positive terminal of the previous slice battery 51 by conductive tape or metal interconnection strip. It should be noted that the metal interconnection strip is preferably a tin-plated metal interconnection strip. The connection is not limited to conductive tape or metal interconnection strip, but can also be other conductive media.

[0041] In this embodiment, it should also be noted that the photovoltaic module contains multiple power generation units 20, wherein there are at least three or more power generation units 20, and the photovoltaic module can be a multi-slice, multi-parallel module, such as a 2-slice, 3-parallel, 3-slice, 4-parallel, 3-slice, 5-parallel module, etc., or a 3-slice, 3-parallel, 4-slice, 4-parallel, 5-slice, 5-parallel module, etc. The more parallel areas of a photovoltaic module composed of the same slice of cells, the greater the output power of the module cells and the greater its power generation. This embodiment does not impose specific limitations.

[0042] In one example, such as Figure 3 As shown, the photovoltaic module contains at least three power generation units 20, namely a first power generation unit 21, a second power generation unit 22, and a third power generation unit 23. The second power generation unit 22 and the third power generation unit 23 are arranged side by side, and the first power generation unit 21 is located below the second power generation unit 22 and the third power generation unit 23. Along the extension direction of the battery string 50, the single battery string 50 is divided into two regions according to the number of sliced ​​cells 51 in a 2:1 ratio and assigned to two different power generation units 20. Since the first power generation unit 21 at the bottom consists of two battery strings 50 connected in series, it is equivalent to the same number of sliced ​​cells 51 in each power generation unit 20, so that the entire photovoltaic module is divided into three sequentially connected second power generation units 22, first power generation units 21, and third power generation units 23.

[0043] The busbars include a first busbar 41 and a second busbar 42. The first power generation unit 21 and the second power generation unit 22 are connected in series via the first busbar 41; the first power generation unit 21 and the third power generation unit 23 are connected in series via the second busbar 42. It should be noted that the second power generation unit 22 has a head busbar 46 at its head, and the third power generation unit 23 has a tail busbar 47 at its tail. Therefore, the head busbar 46 of the second power generation unit 22 serves as the positive electrode, the tail of the second power generation unit 22 and the head of the first power generation unit 21 are connected in series via the first busbar 41, the tail of the first power generation unit 21 and the head of the third power generation unit 23 are connected in series via the second busbar 42, and the tail busbar 47 of the third power generation unit 23 serves as the negative electrode.

[0044] Each power generation unit 20 is also connected to a bypass diode via a busbar, so that the bypass diode is connected in parallel with the corresponding power generation unit 20. Specifically, the busbar also includes a second bypass busbar 44 and a third bypass busbar 45. The bypass diodes include a first bypass diode 31, a second bypass diode 32, and a third bypass diode 33. The first bypass diode 31 is connected to the first busbar 41 and the second busbar 42, and is connected in parallel with the first power generation unit 21 through the first busbar 41 and the second busbar 42. The second bypass diode 32 is connected in parallel with the second power generation unit 22 through the second bypass busbar 44. Specifically, the second bypass busbar 44 is connected to the head busbar 46 and the first busbar 41. The second bypass busbar 44 is composed of two spaced-apart busbar segments, and the second bypass diode 32 is located between the two busbar segments and connects them. The third bypass diode 33 is connected in parallel with the third power generation unit 23 through the third bypass bus bar 45. Specifically, the third bypass bus bar 45 connects the second bus bar 42 and the tail bus bar 47. The third bypass bus bar 45 is composed of two segments of bus bar units that are spaced apart. The third bypass diode 33 is located between the two segments of bus bar units and connects them.

[0045] Specifically, the photovoltaic module is designed as a six-string module. Three battery strings 50 on the left are connected in parallel, three battery strings 50 on the right are connected in parallel, and three battery strings 50 on each side are connected in series. At the same time, bypass diodes are connected in parallel with the corresponding power generation units 20 through busbars to achieve the electrical connection design of three bypass diodes in parallel. For example, the 1st to 22nd sliced ​​battery cells 51 are connected in series to form three battery strings 50, and then the three battery strings 50 are connected in parallel to form the second power generation unit 22. The second bypass diode 32 is connected in parallel through the second bypass busbar 44. Similarly, the 23rd to 44th sliced ​​battery cells 51 are connected in series to form three battery strings 50, and then the three battery strings 50 are connected in parallel to form the first power generation unit 21. The first bypass diode 31 is connected in parallel through the first busbar 41 and the second busbar 42. The 45th to 66th sliced ​​battery cells 51 form the third power generation unit 23. The third bypass diode 33 is connected in parallel through the third bypass busbar 45. The three bypass diodes protect the corresponding power generation units 20. In the structural design, the photovoltaic module is divided into multiple power generation units 20 by busbars. Typically, the number of sliced ​​cells 51 in each power generation unit 20 is equal, ensuring that the output voltage of each power generation unit 20 is equal. The busbars not only separate the power generation units 20 but also connect them; in effect, the busbars connect multiple power generation units 20 in series. The criteria for dividing the power generation units 20 are not specifically required, and the number of sliced ​​cells 51 can be adjusted according to actual needs. The division method in this application is merely an example.

[0046] In the above configuration, the number of sliced ​​cells 51 in each battery string 50 within each bypass diode power generation unit 20 is the same. Similarly, the probability of hot spots being generated at the lower edge of the module is higher than that at the upper edge of the module, which means that the existing photovoltaic module's design method of uniform distribution of hot spot temperature rise is not compatible with the application environment.

[0047] Based on the above, such as Figure 4As shown in the embodiment of this application, the first busbar 41 and the second busbar 42 are shifted as a whole towards the lower edge of the module. At this time, for the second power generation unit 22 and the third power generation unit 23 (equivalent to the upper edge of the module), the number of sliced ​​cells 51 in each battery string 50 increases, while for the first power generation unit 21 (equivalent to the lower edge of the module), the number of sliced ​​cells 51 in each battery string 50 decreases. It can be understood that the original design of equal distribution of the number of sliced ​​cells 51 corresponding to each bypass diode is adjusted to a non-equal distribution design. Since the temperature of the hot spot and the magnitude of the reverse bias voltage on the sliced ​​cells 51 when the hot spot occurs are positively correlated, that is, the number of sliced ​​cells 51 connected in parallel to each bypass diode is positively correlated, when adjusting the number of sliced ​​cells 51, under the premise of ensuring that the battery string 50 at the upper edge of the module meets the hot spot reliability, by adjusting the number of sliced ​​cells 51 to a non-equal distribution design, the battery hot spot temperature at the lower edge of the module can be reduced, thereby improving the module reliability.

[0048] For example, for a 54-cell module, the number of evenly distributed sliced ​​cells 51 corresponding to each bypass diode is 18. In this embodiment, the number of sliced ​​cells 51 in the cell string 50 at the lower edge of the module is adjusted to be less than 18.

[0049] For example, in a 60-cell module, if the number of evenly distributed sliced ​​cells 51 corresponding to each bypass diode is 20, then in this embodiment, the number of sliced ​​cells 51 in the cell string 50 located at the lower edge of the module is adjusted to be less than 20.

[0050] For example, in a 66-cell module, the number of evenly distributed sliced ​​cells 51 corresponding to each bypass diode is 22. In this embodiment, the number of sliced ​​cells 51 in the cell string 50 located at the lower edge of the module is adjusted to be less than 22.

[0051] For example, in a 72-cell module, each bypass diode corresponds to 24 evenly distributed sliced ​​cells 51. Therefore, in this embodiment, the number of sliced ​​cells 51 in the cell string 50 located at the lower edge of the module is adjusted to be less than 24. It should be noted that in current multi-slice and multi-parallel module settings, one bypass diode can manage a maximum of 26-30 sliced ​​cells 51. If the number is greater, additional bypass diodes are required.

[0052] To facilitate understanding, the following examples are provided for reference. Figure 3 As shown, each battery string 50 in the first power generation unit 21, the second power generation unit 22, and the third power generation unit 23 has 22 sliced ​​batteries 51. Since the number of sliced ​​batteries 51 is the same, under the same shading conditions, when hot spots occur in all sliced ​​batteries 51, the temperature rise range is equal, and the hot spot risk is also equal for each sliced ​​battery 51. (Refer to...) Figure 4As shown, when the first busbar 41 and the second busbar 42 are shifted as a whole towards the lower edge of the module, the number of sliced ​​cells 51 in each string of cells 50 in the first power generation unit 21 is reduced to 16, and the number of sliced ​​cells 51 in each string of cells 50 in the second power generation unit 22 and the third power generation unit 23 is increased to 25. Thus, the number of sliced ​​cells 51 at the lower edge of the module is reduced. Under the premise of ensuring that the string of cells 50 at the upper edge of the module meets the hot spot reliability requirements, the hot spot temperature of the cells at the lower edge of the module can be reduced, thereby improving the module reliability and increasing the power generation. It should be noted that the increase in the number of sliced ​​cells 51 at the upper edge of the module must be based on ensuring that the string of cells 50 at the upper edge of the module meets the hot spot reliability requirements. For example, in the original method of evenly distributing 51 sliced ​​cells, the total power output of the photovoltaic module is 210W. The first power generation unit 21, the second power generation unit 22, and the third power generation unit 23 each generate 70W. When the first power generation unit 21 at the bottom edge of the module is shaded, the first bypass diode 31 conducts, effectively rendering the first power generation unit 21 inactive, resulting in a 70W loss, leaving only 140W. However, with the non-uniform distribution design in this embodiment, the power output of the second and third power generation units 22 increases to 90W, while the power output of the first power generation unit 21 decreases to 30W. When the first power generation unit 21 at the bottom edge of the module is shaded, this 30W loss results in a remaining 180W. Therefore, by adopting a non-uniform distribution design, the impact on power output can be minimized, increasing power output compared to the original even distribution method. Similarly, regarding the hot spot temperature of the cells, the original even distribution method reduces the heating temperature, ensuring the safety of the module.

[0053] Example 2

[0054] The difference between Example 2 and Example 1 is as follows: Figure 5As shown, the photovoltaic module forms three power generation units 20, namely the first power generation unit 21, the second power generation unit 22, and the third power generation unit 23. The first power generation unit 21, the second power generation unit 22, and the third power generation unit 23 are arranged sequentially from top to bottom, and the number of sliced ​​cells 51 in the cell string 50 within the first power generation unit 21, the second power generation unit 22, and the third power generation unit 23 are all set in equal numbers. The busbars include a first busbar 41 and a second busbar 42. The first power generation unit 21 and the second power generation unit 22 are connected in series through the first busbar 41, and the second power generation unit 22 and the third power generation unit 23 are connected in series through the second busbar 42. It should be noted that the first power generation unit 21 has a head busbar 46 at its head, and the third power generation unit 23 has a tail busbar 47 at its tail. Therefore, the head busbar 46 of the first power generation unit 21 serves as the positive electrode. The head of the second power generation unit 22 and the tail of the first power generation unit 21 are connected in series through the first busbar 41, and the tail of the second power generation unit 22 and the head of the third power generation unit 23 are connected in series through the second busbar 42. The tail busbar 47 of the third power generation unit 23 serves as the negative electrode.

[0055] Similarly, each power generation unit 20 is also connected to a bypass diode via a busbar, so that the bypass diode is connected in parallel with the corresponding power generation unit 20. Specifically, the busbar also includes a first bypass busbar 43, a second bypass busbar 44, and a third bypass busbar 45. The bypass diodes include a first bypass diode 31, a second bypass diode 32, and a third bypass diode 33. The first bypass diode 31 is connected in parallel with the first power generation unit 21 via the first bypass busbar 43. Specifically, the first bypass busbar 43 connects the head busbar 46 and the first busbar 41. The second bypass diode 32 is connected in parallel with the second power generation unit 22 via the second bypass busbar 44. Specifically, the second bypass busbar 44 connects the first busbar 41 and the second busbar 42. The third bypass diode 33 is connected in parallel with the third power generation unit 23 via the third bypass busbar 45. Specifically, the third bypass busbar 45 connects the second busbar 42 and the tail busbar 47.

[0056] Similarly, in the above configuration, the number of sliced ​​cells 51 in each battery string 50 within each bypass diode power generation unit 20 is the same, which will also lead to the existing photovoltaic module's hot spot temperature rise distribution design not matching the application environment.

[0057] Based on the above, such as Figure 6As shown, in this embodiment, the first busbar 41 connecting the first power generation unit 21 and the second power generation unit 22 is shifted upward, and the second busbar 42 connecting the second power generation unit 22 and the third power generation unit 23 is shifted downward. This makes the number of sliced ​​batteries 51 in the battery string 50 of the first power generation unit 21 at the top and the third power generation unit 23 at the bottom equal, but both less than the number of sliced ​​batteries 51 in the battery string 50 of the second power generation unit 22 in the middle. This design is also a change from the original design where the number of sliced ​​batteries 51 corresponding to each bypass diode was equally divided to a non-equal division design. It should be noted that the first power generation unit 21 is equivalent to the upper edge of the component, the second power generation unit 22 is equivalent to the middle position of the component, and the third power generation unit 23 is equivalent to the lower edge of the component. Of course, the positions of the first power generation unit 21 and the third power generation unit 23 can be interchanged. Under the premise that the battery string 50 of the second power generation unit 22 meets the hot spot reliability requirements, the above-mentioned configuration can reduce the hot spot temperature of the batteries in the first power generation unit 21 and the third power generation unit 23, thereby improving the reliability of the module. In this case, the module has a symmetrical structure and the upper and lower edges can be interchanged. If the upper and lower ends are not clear during the actual installation process, the upper edge can be installed at the bottom and the lower edge can be installed at the top.

[0058] Or, such as Figure 7 As shown, the first busbar 41 connecting the first power generation unit 21 and the second power generation unit 22 is shifted downwards, and the second busbar 42 connecting the second power generation unit 22 and the third power generation unit 23 is also shifted downwards. This makes the number of sliced ​​cells 51 in the battery string 50 of the bottom third power generation unit 23 less than the number of sliced ​​cells 51 in the battery string 50 of the middle second power generation unit 22, and also less than the number of sliced ​​cells 51 in the battery string 50 of the top first power generation unit 21. This design also changes the original equal-division design of the number of sliced ​​cells 51 corresponding to each bypass diode to a non-equal-division design. This reduces the hotspot temperature of the cells at the bottom edge of the module while ensuring the hotspot reliability of the battery strings 50 at the upper edge and middle of the module, thereby improving the module's reliability. It should be noted that in this case, the module has an asymmetrical structure, and the upper and lower edges cannot be interchanged.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A photovoltaic module, characterized by, include: Power generation unit (20) and bypass diode; The power generation unit (20) is configured as multiple units, and the multiple power generation units (20) are connected in series through busbars; each power generation unit (20) includes multiple battery strings (50) connected in parallel with each other, and the battery strings (50) include multiple sliced ​​batteries (51) connected in series in sequence. The sliced ​​battery (51) is a 1 / R slice of the whole battery, where R≥2. Each of the power generation units (20) is also provided with a bypass diode connected in parallel; The number of sliced ​​cells (51) corresponding to each bypass diode is not evenly distributed. The number of sliced ​​cells (51) in the battery string (50) of the power generation unit (20) located at the edge of the photovoltaic module is less than the number of sliced ​​cells (51) in the battery string (50) of the power generation unit (20) in the middle position.

2. The photovoltaic module according to claim 1, characterized in that, The photovoltaic module has at least three power generation units (20) formed therein, namely a first power generation unit (21), a second power generation unit (22) and a third power generation unit (23); The second power generation unit (22) and the third power generation unit (23) are arranged side by side, and the first power generation unit (21) is located below the second power generation unit (22) and the third power generation unit (23); The number of sliced ​​batteries (51) in the battery string (50) in the first power generation unit (21) is less than the number of sliced ​​batteries (51) in the battery string (50) in the second power generation unit (22) and the third power generation unit (23).

3. The photovoltaic module according to claim 2, characterized in that, The busbar includes a first busbar (41) and a second busbar (42); The first power generation unit (21) and the second power generation unit (22) are connected in series via the first busbar (41); The first power generation unit (21) and the third power generation unit (23) are connected in series via the second busbar (42).

4. The photovoltaic module according to claim 3, characterized in that, The bypass diode includes a first bypass diode (31); The first bypass diode (31) connects the first busbar (41) and the second busbar (42); The first bypass diode (31) is connected in parallel with the first power generation unit (21) through the first busbar (41) and the second busbar (42).

5. The photovoltaic module according to claim 4, characterized in that, The busbar also includes a second bypass busbar (44), and the bypass diode also includes a second bypass diode (32); The second bypass busbar (44) is connected to the first busbar (41); The second bypass diode (32) is connected in parallel with the second power generation unit (22) through the second bypass busbar (44); And / or, The busbar also includes a third bypass busbar (45), and the bypass diode also includes a third bypass diode (33); The third bypass busbar (45) is connected to the second busbar (42); The third bypass diode (33) is connected in parallel with the third power generation unit (23) through the third bypass busbar (45).

6. The photovoltaic module according to claim 1, characterized in that, The photovoltaic module has at least three power generation units (20) formed therein, namely a first power generation unit (21), a second power generation unit (22) and a third power generation unit (23), which are arranged from top to bottom. The number of sliced ​​batteries (51) in the battery string (50) in the first power generation unit (21) and the third power generation unit (23) is equal, and both are less than the number of sliced ​​batteries (51) in the battery string (50) in the second power generation unit (22).

7. The photovoltaic module according to claim 1, characterized in that, The photovoltaic module has at least three power generation units (20) formed therein, namely a first power generation unit (21), a second power generation unit (22) and a third power generation unit (23), which are arranged from top to bottom. The number of sliced ​​batteries (51) in the battery string (50) of the third power generation unit (23) is less than the number of sliced ​​batteries (51) in the battery string (50) of the second power generation unit (22), and is also less than the number of sliced ​​batteries (51) in the battery string (50) of the first power generation unit (21).

8. The photovoltaic module according to claim 6 or 7, characterized in that, The busbar includes a first busbar (41) and a second busbar (42); The first power generation unit (21) and the second power generation unit (22) are connected in series via the first busbar (41); The second power generation unit (22) and the third power generation unit (23) are connected in series via the second busbar (42).

9. The photovoltaic module according to claim 8, characterized in that, The busbar also includes a first bypass busbar (43), and the bypass diode includes a first bypass diode (31); The first bypass busbar (43) is connected to the first busbar (41); The first bypass diode (31) is connected in parallel with the first power generation unit (21) through the first bypass busbar (43).

10. The photovoltaic module according to claim 9, characterized in that, The busbar also includes a second bypass busbar (44), and the bypass diode also includes a second bypass diode (32); The second bypass busbar (44) connects the first busbar (41) and the second busbar (42); The second bypass diode (32) is connected in parallel with the second power generation unit (22) through the second bypass busbar (44); And / or, The busbar also includes a third bypass busbar (45), and the bypass diode also includes a third bypass diode (33); The third bypass bus bar (45) is connected with the second bus bar (42); The third bypass diode (33) is connected in parallel with the third power generating unit (23) through the third bypass bus bar (45).

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