Back contact battery assembly and photovoltaic system

Abstract

The invention is suitable for the technical field of solar cells, and provides a back contact cell module and a photovoltaic system. The back contact battery assembly includes an end bus bar; the distance between the first end part battery piece and the end part bus bar in the first direction is a first distance; the first shading strip extends from the end bus bar to the first end battery piece, and a first extending distance is formed in the first direction; the second shading strip extends from the first end part battery piece to the end part bus bar, and forms a second extending distance in the first direction; the sum of the first extending distance and the second extending distance is larger than or equal to the first interval. Therefore, the combination of the second shading strip and the first shading strip can cover the gap between the first end part battery piece and the end part bus bar, so that the width of the second shading strip and the width of the first shading strip can be matched with the width of the gap between the first end part battery piece and the end part bus bar; therefore, the beautiful effect and the power generation efficiency of the back contact battery assembly can be improved.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and particularly relates to a back-contact battery module and photovoltaic system. Background Technology

[0002] In related technologies, photovoltaic modules consist of busbars and cell strings, with shading strips typically placed in the gaps between them. However, poor matching between the shading strips and the gaps can easily lead to the cells being blocked or the gaps not being completely blocked, thus affecting the aesthetics and power generation efficiency of the photovoltaic modules.

[0003] Therefore, the width of the light-shielding strip is difficult to match the gap between the battery cells and the busbar, which has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a back-contact battery module and photovoltaic system, which aims to solve the problem that the width of the shading strip is difficult to match the gap between the battery cell and the busbar.

[0005] A first aspect of this application provides a back contact battery assembly, the back contact battery assembly comprising: End busbar; The first battery string includes a first end solder strip and a first end battery cell. The first end battery cell is electrically connected to the end busbar through the first end solder strip. The distance between the first end battery cell and the end busbar in a first direction is a first distance. The first light-shielding strip extends from the end busbar toward the first end battery cell, forming a first extension distance in the first direction; The second light-shielding strip extends from the first end battery cell toward the end busbar, forming a second extension distance in the first direction; Wherein, the sum of the first extension distance and the second extension distance is greater than or equal to the first spacing.

[0006] Optionally, the back contact battery assembly satisfies: L ≤ 1 / 2 W; Where L is the second extension distance and W is the total width of the second light-shielding strip.

[0007] Optionally, the back contact battery assembly satisfies: 1 / 2 W - 0.5 ≤ L ≤ 1 / 2 W + 0.5; Where L is the second extension distance and W is the total width of the second light-shielding strip.

[0008] Optionally, the back contact battery assembly includes a second battery string, the first battery string and the second battery string are arranged along a second direction, which intersects the first direction; both the first battery string and the second battery string include a plurality of back contact battery cells arranged along the first direction and connected in series, and the number of back contact battery cells in the first battery string and the second battery string is the same. In the first direction, the back contact battery assembly has a central busbar, and in the first battery string, the back contact battery cell closest to the central busbar is the second end battery cell; In the second battery string, the back contact battery cell closest to the end busbar is the third end battery cell, and the back contact battery cell closest to the middle busbar is the fourth end battery cell. The distance between the third end battery cell and the end busbar in the first direction is the second distance. The second battery string has a second end solder strip, and the third end battery cell is electrically connected to the end busbar through the second end solder strip. Wherein, the second end battery cell in the first battery string and the fourth end battery cell in the second battery string are aligned in the second direction, and the first spacing is greater than the second spacing.

[0009] Optionally, the back contact battery assembly includes a third light-shielding strip that extends from the third end battery cell toward the end busbar, forming a third extension distance in the first direction, the third extension distance being less than the second extension distance.

[0010] Optionally, the sum of the first extension distance and the third extension distance is greater than or equal to the second spacing.

[0011] Optionally, the back contact battery assembly satisfies: W≥2 h, where W is the total width of the second light-shielding strip. h is the difference between the first spacing and the second spacing.

[0012] Optionally, the back contact battery assembly satisfies: W≥2 h+2.

[0013] Optionally, the back contact battery assembly includes a plurality of battery string groups, each of the battery string groups including a first battery string and a second battery string, and the plurality of battery string groups are arranged along the second direction; The first battery string in different battery string groups has the same length in the first direction; Alternatively, the lengths of the first battery strings in different battery string groups may differ in the first direction; The second battery string in different battery string groups has the same length in the first direction; Alternatively, the lengths of the second battery strings in different battery string groups may differ in the first direction.

[0014] A second aspect of this application provides a photovoltaic system including either the first aspect or the second aspect of an optional back-contact battery module.

[0015] As can be seen from the above technical solutions, this application has the following effects: In the back-contact battery module and photovoltaic system of this application embodiment, since the sum of the first extension distance and the second extension distance is greater than or equal to the first spacing, the combination of the second shading strip and the first shading strip can cover the gap between the first end battery cell and the end busbar, so that the width of the second shading strip and the first shading strip can match the width of the gap between the first end battery cell and the end busbar. This reduces the situation where the first end battery cell is blocked or the gap between the first end battery cell and the end busbar cannot be completely blocked, thereby improving the aesthetic effect and power generation efficiency of the back-contact battery module. Attached Figure Description

[0016] Figure 1 This is a top view schematic diagram of a back contact battery assembly according to an embodiment of this application; Figure 2 This is a side view schematic diagram of a back contact battery assembly according to an embodiment of this application; Figure 3 This is a top view schematic diagram of a back contact battery assembly according to another embodiment of this application.

[0017] Explanation of key component symbols: End busbar-1, first battery string-2, first end solder strip-21, first end battery cell-22, second end battery cell-23, first light-shielding strip-3, second light-shielding strip-4, second battery string-5, second end solder strip-51, third end battery cell-52, fourth end battery cell-53, intermediate busbar-6, third light-shielding strip-7, battery string group-100. Detailed Implementation

[0018] 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. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0019] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0024] Please see Figure 1 and Figure 2 The back contact battery assembly in this application embodiment includes: End busbar 1; The first battery string 2 includes a first end battery piece 22, which is electrically connected to the end busbar 1. The distance between the first end battery piece 22 and the end busbar 1 in the first direction is a first distance. The first light-shielding strip 3 extends from the end busbar 1 toward the first end battery cell 22, forming a first extension distance in a first direction; The second light-shielding strip 4 extends from the first end battery cell 22 toward the end busbar 1, forming a second extension distance in the first direction; Wherein, the sum of the first extension distance and the second extension distance is greater than or equal to the first spacing.

[0025] In this embodiment, since the sum of the first extension distance and the second extension distance is greater than or equal to the first gap, the combination of the second light-shielding strip 4 and the first light-shielding strip 3 can cover the gap between the first end battery cell 22 and the end busbar 1, so that the width of the second light-shielding strip 4 and the first light-shielding strip 3 can match the width of the gap between the first end battery cell 22 and the end busbar 1. This reduces the situation where the first end battery cell 22 is blocked or the gap between the first end battery cell 22 and the end busbar 1 cannot be completely blocked, thereby improving the aesthetic effect and power generation efficiency of the back contact battery assembly.

[0026] Specifically, the first battery string 2 includes a plurality of back contact battery cells. The plurality of back contact battery cells are connected in series along a first direction, and adjacent back contact battery cells are electrically connected by solder strips. It should be noted that the first direction can be a horizontal direction from left to right or a vertical direction from top to bottom, and the specific first direction can be determined according to the actual process layout requirements, and is not limited here.

[0027] It is understood that the number of back contact solar cells in the first battery string 2 is unlimited. For example, the number of back contact solar cells in the first battery string 2 can be 5, 6, 7, or 8, or it can be 12, 13, 14, or 15. The specific number can be set according to the actual power generation requirements and is not limited here.

[0028] Specifically, the end busbar 1 is located at the end of the first battery string 2 in the first direction. For example, if the first direction is a horizontal direction from left to right, the end busbar 1 is located at the leftmost or rightmost side of the first battery string 2.

[0029] Among them, the back contact battery cell closest to the end busbar 1 in the first battery string 2 is the first end battery cell 22, and the solder strip between the first end battery cell 22 and the end busbar 1 is the first end solder strip 21.

[0030] Specifically, a first light-shielding strip 3 is disposed on the end busbar 1. The total width of the first light-shielding strip 3 in the first direction is greater than the total width of the end busbar 1 in the first direction. The portion of the first light-shielding strip 3 that extends beyond the end busbar 1 protrudes from the end plane of the end busbar 1 near the first end battery cell 22 in the first direction; this protruding portion is the first protrusion distance. Please refer to [link / reference]. Figure 2 As shown, the first extension distance is J.

[0031] The second light-shielding strip 4 is disposed on the first end battery cell 22. The second light-shielding strip 4 includes a fixing part and a blocking part. The fixing part of the second light-shielding strip 4 is fixed to the first end battery cell 22. For example, the fixing part of the second light-shielding strip 4 is fixed between the first end battery cell 22 and the first end solder strip 21 by lamination.

[0032] The blocking portion of the second light-shielding strip 4 extends out of the end plane of the first end battery cell 22 near the end busbar 1. The width of the blocking portion of the second light-shielding strip 4 in the first direction is the second extension distance of the second light-shielding strip 4. Please refer to [link / reference]. Figure 2 As shown, the distance of the second extension is L.

[0033] In related technologies, the length of the first battery string 2 is affected by factors such as manufacturing precision. During the actual assembly of the back-contact battery assembly, the first spacing between the first end battery cell 22 and the end busbar 1 will deviate from the preset spacing. In this embodiment, by setting the sum of the first extension distance and the second extension distance to be greater than or equal to the first spacing (the first spacing is within...), the length of the first battery string 2 is affected by factors such as manufacturing precision. Figure 2As shown in the diagram (H), the extended portion of the first light-shielding strip 3 and the blocking portion of the second light-shielding strip 4 can be used to completely block the first end solder strip 21 between the first end battery cell 22 and the end busbar 1. This reduces the possibility of the first end solder strip 21 between the first end battery cell 22 and the end busbar 1 not being completely blocked due to the second light-shielding strip 4 being too short in the first direction, thus improving the aesthetics of the back contact battery assembly. It also reduces the possibility of the first end battery cell 22 being partially blocked by the second light-shielding strip 4 due to the second light-shielding strip 4 being too long in the first direction, thus improving the power generation efficiency of the back contact assembly.

[0034] In some embodiments, the back contact battery assembly satisfies: ;in, For the second extension distance, This is the total width of the second light-shielding strip 4.

[0035] Specifically, the second extension distance can be set to be less than or equal to half the total width of the second light-shielding strip 4. For example, if the total width of the second light-shielding strip 4 is 7mm, the second extension distance is half the total width of the second light-shielding strip 4, i.e., 3.5mm; or the second extension distance is one-quarter of the total width of the second light-shielding strip 4, i.e., 1.75mm. By limiting the second extension distance to this range, the connection stability between the second light-shielding strip 4 and the first end battery cell 22 can be improved, reducing the possibility of the second light-shielding strip 4 detaching. It should be noted that the total width of the second light-shielding strip 4 refers to the total width of the second light-shielding strip 4 in the first direction.

[0036] In some embodiments, the back contact battery assembly satisfies: ;in, This is the second extension distance. This refers to the total width of the second light-shielding strip 4.

[0037] Specifically, during the process of connecting and fixing the second light-shielding strip 4 to the first end battery cell 22, the fixing part of the second light-shielding strip 4 may be offset from the installation position of the first end battery cell 22, so that the actual second extension distance will deviate from the preset value.

[0038] Therefore, in this embodiment, a deviation coefficient of 0.5mm can be set for the second extension distance. The numerical range of the second extension distance is set to be greater than or equal to the difference between half the total width of the second light-shielding strip 4 and the deviation coefficient, and less than or equal to the sum of half the total width of the second light-shielding strip 4 and the deviation coefficient. For example, if the total width of the second light-shielding strip 4 is 7mm, the second extension distance is the difference between half the total width of the second light-shielding strip 4 and the deviation coefficient, i.e., 3.5-0.5=2mm; or the second extension distance is the sum of half the total width of the second light-shielding strip 4 and the deviation coefficient, i.e., 3.5+0.5=4mm. By limiting the second extension distance to this numerical range, the influence of the installation deviation of the second light-shielding strip 4 can be weakened, thereby improving the connection stability between the second light-shielding strip 4 and the first end battery cell 22 and reducing the possibility of the second light-shielding strip 4 falling off.

[0039] Please see Figure 3 In some embodiments, the back contact battery assembly includes a second battery string 5, the first battery string 2 and the second battery string 5 are arranged along a second direction, which intersects with the first direction; the first battery string 2 and the second battery string 5 each include a plurality of back contact battery pieces arranged along the first direction and connected in series, and the number of back contact battery pieces in the first battery string 2 and the second battery string 5 is the same. In the first direction, the back contact battery assembly has a central busbar 6, and in the first battery string 2, the back contact battery cell closest to the central busbar 6 is the second end battery cell 23. In the second battery string 5, the back contact battery cell closest to the end busbar 1 is the third end battery cell 52, and the back contact battery cell closest to the middle busbar 6 is the fourth end battery cell 53. The distance between the third end battery cell 52 and the end busbar 1 in the first direction is the second distance. The second battery string 5 has a second end solder strip 51, and the third end battery cell 52 is electrically connected to the end busbar 1 through the second end solder strip 51. In this configuration, the second end battery piece 23 in the first battery string 2 and the fourth end battery piece 53 in the second battery string 5 are aligned in the second direction, and the first spacing is greater than the second spacing.

[0040] Specifically, the second battery string 5 includes a plurality of back-contact battery cells. These back-contact battery cells are connected in series along the first direction, and adjacent back-contact battery cells are electrically connected by solder strips. It is understood that the number of back-contact battery cells in the second battery string 5 is unlimited, and the number of back-contact battery cells in the first battery string 2 is the same as the number of back-contact battery cells in the second battery string 5. For example, the number of back-contact battery cells in both the first battery string 2 and the second battery string 5 can be 5, 6, 7, or 8, or it can also be 12, 13, 14, or 15. The specific number can be set according to the actual power requirement, and is not limited here.

[0041] The second battery string 5 and the first battery string 2 are connected in series along the second direction. It should be noted that the first direction and the second direction are not specific fixed directions, but two opposite directions that intersect each other.

[0042] For example, if the first battery string 2 and the second battery string 5 are arranged from top to bottom, the second direction is the "vertical direction"; if several back-contact battery pieces in the first battery string 2 and the second battery string 5 are arranged from left to right, the first direction is the "horizontal direction". In this case, the first direction and the second direction are perpendicular to each other.

[0043] For example, if the first battery string 2 and the second battery string 5 are arranged from left to right, the second direction is the "horizontal direction"; if the back contact battery pieces in the first battery string 21 and the second battery string 5 are arranged from top to bottom, the first direction is the "vertical direction". At this time, the first direction and the second direction are still perpendicular to each other.

[0044] The intermediate busbar 6 and the end busbar 1 are respectively disposed on the two ends of the first battery string 2 and the second battery string 5 in the first direction. The intermediate busbar 6 and the end busbar 1 may be hidden on the back of the first battery string 2 and the second battery string 5, or they may not be hidden on the back of the first battery string 2 and the second battery string 5. The solder strip between the third end battery piece 52 and the end busbar 1 is the second end solder strip 51.

[0045] It is understood that the end busbar 1 and the intermediate busbar 6 are parallel to each other, and the first direction and the second direction are perpendicular to each other. The first direction can be a direction perpendicular to the end busbar 1, or it can be understood as a direction perpendicular to the intermediate busbar 6. The second direction can be a direction parallel to the end busbar 1, or it can be understood as a direction parallel to the intermediate busbar 6.

[0046] Specifically, the second end battery piece 23 in the first battery string 2 and the fourth end battery piece 53 in the second battery string 5 are aligned in the second direction. This can be understood as the spacing between the second end battery piece 23 in the first battery string 2 and the intermediate busbar 6 being the same as the spacing between the fourth end battery piece 53 in the second battery string 5 and the intermediate busbar 6. By aligning the second end battery piece 23 in the first battery string 2 and the fourth end battery piece 53 in the second battery string 5 in the second direction, the stability of current conduction can be ensured.

[0047] The first distance between the first end battery cell 22 and the end busbar 1 in the first battery string 2 is greater than the second distance between the third end battery cell 52 and the end busbar 1 in the second battery string 5.

[0048] Therefore, in the manufacturing process of back-contact battery modules, it is not necessary to precisely align the first end cell 22, the third end cell 52, and the end busbar 1 in different cell strings. This reduces the need for repeated adjustments to the positions of the first cell string 2 and the second cell string 5 by adding additional visual inspection equipment and moving equipment. This reduces the complexity of the process, increases the cycle time of manufacturing back-contact battery modules, and ultimately improves the production and manufacturing efficiency of back-contact battery modules.

[0049] Meanwhile, because the second spacing is smaller than the first spacing, the shadow will first block the third end cell 52 in the second battery string 5, and then move towards the first end cell 22 in the first battery string 2, gradually blocking the first end cell 22 in the first battery string 2. When the third end cell 52 is blocked by the shadow, the power generation capacity will drop sharply, becoming a load that consumes the power of other cells, leading to a local temperature increase and forming a hot spot effect. After the temperature detection device detects the hot spot effect of the third end cell 52, for example, if the temperature difference between the third end cell 52 and other cells is greater than a preset temperature value or the current difference between the third end cell 52 and other cells is greater than a preset current value, the shadow blocking triggering mechanism will be triggered immediately. When the shadow blocking triggering mechanism starts to operate, the central control system adjusts the bracket, causing it to move the first battery string 2 and the second battery string 5 simultaneously away from the shadow. In this way, the third end cell 52 can change from a shadowed state to an unshaded state, thereby reducing the power generation loss during the time from when the third end cell 52 is blocked by the shadow to when the shadow is removed.

[0050] In some embodiments, the back contact battery assembly includes a third light-shielding strip 7 that extends from the third end battery cell 52 toward the end busbar 1 and forms a third extension distance in a first direction, the third extension distance being less than the second extension distance.

[0051] Specifically, since the first spacing is greater than the second spacing, and both the first end battery cell 22 and the third end battery cell 52 are electrically connected to the end busbar 1, the third extension distance of the third light-shielding strip 7 can be set to be less than the extension distance of the second light-shielding strip 4 to reduce the ineffective area of ​​the third light-shielding strip 7, thereby reducing the manufacturing cost of the third light-shielding strip 7 and improving the space utilization of the back contact battery assembly.

[0052] Furthermore, the sum of the first extension distance and the third extension distance is greater than or equal to the second spacing.

[0053] Specifically, by setting the sum of the first extension distance and the third extension distance to be greater than or equal to the second spacing, the combination of the first light-shielding strip 3 and the third light-shielding strip 7 can be used to completely block the second end solder strip 51 between the third end battery cell 52 and the end busbar 1. This reduces the possibility that the second end solder strip 51 between the third end battery cell 52 and the end busbar 1 cannot be completely blocked due to the width of the third light-shielding strip 7 being too short in the first direction, thereby further improving the aesthetics of the back contact battery module. It also reduces the possibility that the third end battery cell 52 will be partially blocked by the third light-shielding strip 7 due to the width of the third light-shielding strip 7 being too long in the first direction, thereby further improving the power generation efficiency of the back contact module.

[0054] In some embodiments, the back contact battery assembly satisfies: ,in The total width of the second light-shielding strip 4 This is the difference between the first spacing and the second spacing.

[0055] Specifically, the total width of the second light-shielding strip 4 can be set to be greater than or equal to twice the difference between the first and second spacing. For example, if the difference between the first and second spacing is 2.5mm, the total width of the second light-shielding strip 4 is twice the difference between the first and second spacing, i.e., 5mm; or, the total width of the second light-shielding strip 4 is three times the difference between the first and second spacing, i.e., 7.5mm. By limiting the total width of the second light-shielding strip 4 to this range, the connection stability between the second light-shielding strip 4 and the first end battery cell 22 can be improved, reducing the possibility of the second light-shielding strip 4 detaching.

[0056] Furthermore, the back contact battery assembly satisfies: .

[0057] Specifically, based on the installation offset of the second light-shielding strip 4, a deviation coefficient of 2mm can be set for the total width of the second light-shielding strip 4. Alternatively, the total width of the second light-shielding strip 4 can be set to be greater than or equal to the sum of twice the difference between the first and second spacings and the deviation coefficient. If the difference between the first and second spacings is 2.5mm, the total width of the second light-shielding strip 4 is the sum of twice the difference between the first and second spacings and the deviation coefficient, i.e., 5+2=7mm; or, the total width of the second light-shielding strip 4 can be the sum of three times the difference between the first and second spacings and the deviation coefficient, i.e., 7.5+2=9.5mm. By limiting the total width of the second light-shielding strip 4 to this range, the impact of installation errors on the second light-shielding strip 4 can be reduced, thereby further improving the connection stability between the second light-shielding strip 4 and the first end battery cell 22 and reducing the possibility of the second light-shielding strip 4 detaching.

[0058] In some embodiments, the back contact battery assembly includes a plurality of battery string groups 100, each battery string group 100 including a first battery string 2 and a second battery string 5, and the plurality of battery string groups 100 are arranged along a second direction. The first battery string 2 in different battery string groups 100 has the same length in the first direction; Alternatively, the lengths of the first battery string 2 in different battery string groups 100 are different in the first direction; The second battery string 5 in different battery string groups 100 has the same length in the first direction; Alternatively, the length of the second battery string 5 in different battery string groups 100 may differ in the first direction.

[0059] Specifically, by simultaneously setting up multiple battery string groups 100, the overall power generation of the back-contact battery module can be increased. By not limiting the length of the first battery string 2 in different battery string groups 100 and the length of the second battery string 5 in different battery string groups 100, the back-contact battery module can be adapted to various sizes or types of back-contact battery cells, thus improving the process flexibility of the back-contact battery module.

[0060] The photovoltaic system of this application includes the back contact battery module in any of the above embodiments.

[0061] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0062] In the description of this specification, the references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] Furthermore, the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A back-contact battery assembly, characterized in that, The back contact battery assembly includes: End busbar; The first battery string includes a first end solder strip and a first end battery cell. The first end battery cell is electrically connected to the end busbar through the first end solder strip. The distance between the first end battery cell and the end busbar in a first direction is a first distance. The first light-shielding strip extends from the end busbar toward the first end battery cell, forming a first extension distance in the first direction; The second light-shielding strip extends from the first end battery cell toward the end busbar, forming a second extension distance in the first direction; Wherein, the sum of the first extension distance and the second extension distance is greater than or equal to the first spacing.

2. The back contact battery assembly according to claim 1, characterized in that, The back contact battery assembly satisfies: ; in, This is the second extension distance. This is the total width of the second light-shielding strip.

3. The back contact battery assembly according to claim 1, characterized in that, The back contact battery assembly satisfies: ; in, This is the second extension distance. This is the total width of the second light-shielding strip.

4. The back contact battery assembly according to claim 1, characterized in that, The back contact battery assembly includes a second battery string, the first battery string and the second battery string are arranged along a second direction, which intersects the first direction; both the first battery string and the second battery string include a plurality of back contact battery cells arranged along the first direction and connected in series, and the number of back contact battery cells in the first battery string and the second battery string is the same; In the first direction, the back contact battery assembly has a central busbar, and in the first battery string, the back contact battery cell closest to the central busbar is the second end battery cell; In the second battery string, the back contact battery cell closest to the end busbar is the third end battery cell, and the back contact battery cell closest to the middle busbar is the fourth end battery cell. The distance between the third end battery cell and the end busbar in the first direction is the second distance. The second battery string has a second end solder strip, and the third end battery cell is electrically connected to the end busbar through the second end solder strip. Wherein, the second end battery cell in the first battery string and the fourth end battery cell in the second battery string are aligned in the second direction, and the first spacing is greater than the second spacing.

5. The back contact battery assembly according to claim 4, characterized in that, The back contact battery assembly includes a third light-shielding strip that extends from the third end battery cell toward the end busbar, forming a third extension distance in the first direction, and the third extension distance is less than the second extension distance.

6. The back contact battery assembly according to claim 5, characterized in that, The sum of the first extension distance and the third extension distance is greater than or equal to the second spacing.

7. The back contact battery assembly according to claim 5, characterized in that, The back contact battery assembly satisfies: ,in The total width of the second light-shielding strip. It is the difference between the first spacing and the second spacing.

8. The back contact battery assembly according to claim 7, characterized in that, The back contact battery assembly satisfies: .

9. The back contact battery assembly according to claim 4, characterized in that, The back contact battery assembly includes several battery string groups, each battery string group including a first battery string and a second battery string, and the several battery string groups are arranged along the second direction. The first battery string in different battery string groups has the same length in the first direction; Alternatively, the lengths of the first battery strings in different battery string groups may differ in the first direction; The second battery string in different battery string groups has the same length in the first direction; Alternatively, the lengths of the second battery strings in different battery string groups may differ in the first direction.

10. A photovoltaic system, characterized in that, Includes the back contact battery assembly according to any one of claims 1 to 9.

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