Photovoltaic module

Abstract

The application relates to a photovoltaic module, comprising: a plurality of cell strings; a plurality of bus bars arranged transversely respectively for connecting adjacent cell strings in series; a plurality of jumpers arranged longitudinally respectively for being connected on the bus bars; a groove is arranged at the connection between the bus bar and the jumper, and the jumper is embedded in the groove. By arranging the groove structure at the connection between the bus bar and the jumper, the protrusion height at the connection between the bus bar and the jumper is effectively reduced, the stress generated by the cold shrinkage of the laminated material and the glass cover plate in a low-temperature environment is effectively reduced, the risk of the glass cover plate being burst is reduced, and the long-term reliability and safety of the photovoltaic module are improved.

Description

Technical Field

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

[0002] With the development of technology in the photovoltaic module field, the entire cell is divided into multiple smaller pieces. By increasing the number of main grids, the current transmission path is shortened, thereby reducing resistance loss.

[0003] In related technologies, electrical connections between battery strings are typically achieved by welding busbars to connectors, such as metal conductive strips. Because the busbars and connectors are welded together in layers, the thickness of the connectors, solder, and the busbars themselves overlaps, creating localized protrusions. In low-temperature environments, the laminated material and the glass cover will shrink, causing stress concentration at these protrusions. This can easily lead to the glass cover cracking, affecting the safety and reliability of the photovoltaic modules. Utility Model Content

[0004] Therefore, it is necessary to provide a photovoltaic module that addresses the problems of large protrusion thickness and stress concentration at the existing busbar and connector layer welding joints, which affect the safety of photovoltaic module use.

[0005] A photovoltaic module, comprising:

[0006] Multiple battery strings;

[0007] Multiple busbars are arranged horizontally to connect adjacent battery strings in series;

[0008] Multiple jumpers, each arranged longitudinally, are used to connect to the busbar;

[0009] A groove is provided at the connection between the bus bar and the jumper, and the jumper is embedded in the groove.

[0010] In one embodiment, the depth of the groove is greater than or equal to the thickness of the jumper wire.

[0011] In one embodiment, the groove is a through slot that extends along the length of the busbar and passes through the width of the busbar.

[0012] In one embodiment, the cross-section of the groove is rectangular, trapezoidal, or arc-shaped.

[0013] In one embodiment, the busbar includes a first edge busbar, a second edge busbar, and at least one interconnecting busbar disposed between the first edge busbar and the second edge busbar; wherein the first edge busbar, the second edge busbar, and the interconnecting busbar are all provided with the groove, and at least one jumper wire has both ends embedded and welded into the groove.

[0014] In one embodiment, each battery string is formed by connecting multiple battery cells in series via conductive connectors; the battery cells are multi-cell batteries.

[0015] In one embodiment, the width of the busbar is 3mm-10mm.

[0016] In one embodiment, the thickness of the busbar is 0.1mm-0.8mm.

[0017] In one embodiment, the jumper wire has a width of 3mm-15mm.

[0018] In one embodiment, the thickness of the jumper is 0.1mm-0.5mm.

[0019] The aforementioned photovoltaic module, by creating a groove structure at the connection between the busbar and the jumper, effectively reduces the protrusion height at the connection point, effectively reduces the stress caused by the cold contraction of the laminate material and the glass cover in low-temperature environments, thereby reducing the risk of the glass cover cracking and improving the long-term reliability and safety of the photovoltaic module. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the solar cell layer of the photovoltaic module according to an embodiment of this application. Figure 1 .

[0021] Figure 2 This is a schematic diagram of the structure of the solar cell layer of the photovoltaic module according to an embodiment of this application. Figure 2 .

[0022] Figure 3 This is a schematic diagram of the connection between the jumper and the bus bar in an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the groove structure according to an embodiment of this application.

[0024] In the diagram: 11, First edge busbar; 12, Second edge busbar; 131, First interconnect busbar; 132, Second interconnect busbar; 133, Third interconnect busbar; 20, Jumper; 30, Groove. Detailed Implementation

[0025] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0026] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms 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.

[0027] Furthermore, where the terms "first" and "second" appear, these terms are 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 with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0030] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0031] Currently, electrical connections between multiple battery strings are mostly achieved through welding busbars and connectors, such as metal conductive strips. Because the busbars and connectors are welded together in layers, the thickness of the connectors, solder, and the busbars themselves overlaps, creating localized protrusions. In low-temperature environments, the laminated material and the glass cover will shrink, causing stress concentration at these protrusions. This can easily lead to the glass cover cracking, affecting the safety and reliability of the photovoltaic modules.

[0032] like Figure 1 , Figure 2 As shown, Figure 1 This is a schematic diagram of the structure of the solar cell layer of the photovoltaic module according to an embodiment of this application. Figure 1 . Figure 2 This is a schematic diagram of the structure of the solar cell layer of the photovoltaic module according to an embodiment of this application. Figure 2 .

[0033] To solve the above-mentioned technical problems, an embodiment of this application provides a photovoltaic module, including: multiple battery strings; multiple busbars, each arranged horizontally for connecting adjacent battery strings in series; multiple jumpers 20, each arranged vertically for connecting to the busbars; a groove 30 is provided at the connection between the busbar and the jumper 20, and the jumper 20 is embedded in the groove 30.

[0034] The photovoltaic module comprises, from top to bottom, a glass cover plate, an upper encapsulant layer, a cell layer, a lower encapsulant layer, and a backsheet. The cell layer includes multiple cell strings, each consisting of multiple cells connected in series. The cells are crystalline silicon cells of types such as PERC, TOPCon, HJT, or BC. The substrate of the cells is a doped N-type silicon wafer or a doped P-type silicon wafer. The doping elements for the N-type silicon wafer include one or more of phosphorus, arsenic, and antimony; the doping elements for the P-type silicon wafer include one or more of boron, indium, and gallium.

[0035] Multiple busbars extend laterally along the photovoltaic module, i.e., along the short side of the photovoltaic module. The busbars are conductive metal strips, such as copper strips, tin-plated copper strips, or copper alloy strips. Each busbar's two ends are electrically connected to the electrodes on the end cells of two adjacent cell strings via soldering, thereby achieving series connection of the cell strings.

[0036] Multiple jumpers 20 extend along the longitudinal direction of the photovoltaic module, i.e., along the long side of the photovoltaic module. Jumpers 20 are also conductive metal strips, such as copper strips, tin-plated copper strips, or copper alloy strips. Jumpers 20 are used to bridge two busbars that require electrical connection, thus achieving circuit bridging.

[0037] At the connection between the busbar and the jumper 20, a groove 30 is formed on the busbar. This groove 30 can be formed by processes such as stamping, etching, or engraving. The thickness of the groove 30 is slightly greater than the thickness of the busbar; the width of the groove 30 is the same as or slightly greater than the width of the jumper 20. The cross-sectional shape of the groove 30 can be rectangular, trapezoidal, arc-shaped, or other shapes.

[0038] The jumper wire 20 is embedded in the groove 30 and is fixedly connected to the busbar by solder. The solder can be pre-applied solder paste. Because the jumper wire 20 is partially embedded in the groove 30 of the busbar, the total thickness at the connection point is significantly reduced. Compared to the traditional layered welding structure, the total thickness at the connection point between the jumper wire 20 and the busbar is significantly reduced, resulting in a smoother surface for the photovoltaic module.

[0039] The aforementioned photovoltaic module effectively reduces the protrusion height at the connection point between the busbar and jumper 20 by creating a groove 30 on the busbar. In low-temperature environments, the stress generated by the cold contraction of the laminated material (EVA or POE) and the glass cover is effectively reduced, thereby lowering the risk of glass cover shattering and improving the long-term reliability and safety of the photovoltaic module. Compared to traditional lamination welding processes, this effectively improves reliability without increasing process complexity.

[0040] Furthermore, the bottom surface of the groove 30 may also have multiple pits or protrusions. When solder fills the groove 30, the pits or protrusions make full contact with the solder, thereby improving the connection strength and stability at the connection between the busbar and the jumper 20.

[0041] Furthermore, the groove 30 is formed on the jumper 20. When the jumper 20 is connected to the busbar, the groove 30 on the jumper 20 snaps into or fits into the busbar and is welded with solder. This improves the flexibility of welding the jumper 20 and the busbar while reducing the thickness at the connection point.

[0042] Furthermore, the connection between the busbar and the jumper 20 can be provided with matching grooves 30 and protrusions, respectively. The busbar has grooves 30, and the lower surface of the jumper 20 has corresponding protrusions. After the two are fitted together, they are welded and fixed, which further reduces the connection thickness, improves flatness, and improves alignment accuracy and connection accuracy, thereby improving welding efficiency.

[0043] like Figure 3 As shown, Figure 3 This is a schematic diagram showing the connection between the jumper 20 and the busbar according to an embodiment of this application. In one embodiment, the depth of the groove 30 is greater than or equal to the thickness of the jumper 20.

[0044] The depth of the groove 30 refers to the vertical distance from the upper surface of the busbar to the bottom of the groove 30.

[0045] The depth of the groove 30 is configured to be greater than or equal to the thickness of the jumper 20, and the width of the groove 30 is slightly greater than the width of the jumper 20 to ensure that the jumper 20 can be smoothly embedded in the groove 30 and to allow space for solder filling. After the jumper 20 is fully embedded in the groove 30, the upper surface of the jumper 20 is not higher than or slightly lower than the upper surface of the busbar. The jumper 20 is soldered to the busbar with solder. The solder can fill the gaps between the jumper 20 and the sidewalls and bottom of the groove 30 to ensure that the solder does not overflow after soldering, avoid bulges at the connection, ensure the flatness of the connection, and form a smooth solder interface.

[0046] In one embodiment, the groove 30 is a through groove that extends along the length direction of the busbar and penetrates along the width direction of the busbar.

[0047] The groove 30 is a through slot formed on the busbar, extending laterally along the length of the busbar and penetrating both sides along its width. The width of the through slot can be greater than or equal to the width of the jumper 20 to ensure that the jumper 20 can be embedded within it. The through slot structure positions and limits the jumper 20, restricting its movement, reducing welding difficulty, and improving the flatness of the weld.

[0048] The jumper wire 20 is arranged longitudinally and passes through the through slot. The portion of the jumper wire 20 at the through slot is welded to the busbar for electrical connection. The jumper wire 20 passes through the busbar for welding, avoiding the thickness accumulation problem of traditional layered welding, effectively reducing the thickness at the connection, avoiding stress concentration during low-temperature shrinkage, and improving reliability.

[0049] Furthermore, since the through slot is a through structure, the jumper wire 20 can enter from one side and exit from the other; the portion of the jumper wire 20 inside the through slot is welded to the busbar. This through-type connection structure effectively increases the welding area and improves the connection strength.

[0050] The through groove can be integrally formed during the manufacturing of the busbar through processes such as stamping and laser cutting.

[0051] like Figure 4 As shown, Figure 4 This is a schematic diagram of the groove 30 according to an embodiment of this application. In one embodiment, the groove 30 has a rectangular cross-section. The rectangular groove 30 has a sidewall perpendicular to the upper surface of the busbar and a groove bottom parallel to the lower surface of the busbar, which is adapted to the rectangular jumper 20. The depth and width of the rectangular groove 30 are greater than or equal to the thickness and width of the jumper 20. The rectangular groove 30 has a simple structure and is easy to manufacture.

[0052] In one embodiment, the groove 30 has a trapezoidal cross-section. The trapezoidal groove 30 has inclined sidewalls, and its opening width is greater than the bottom width. The trapezoidal groove 30 helps guide the flow of solder during welding, improving the welding effect, and guides the movement of the jumper 20 when it is engaged, facilitating the installation, positioning, and welding of the jumper 20.

[0053] In one embodiment, the groove 30 has an arc-shaped cross-section. The arc-shaped groove 30 has smoothly transitioned sidewalls and a rounded bottom. The arc-shaped groove 30 effectively reduces stress concentration at the connection between the jumper 20 and the busbar, avoiding the risk of breakage.

[0054] like Figure 1 , Figure 2 As shown, Figure 1 This is a schematic diagram of the structure of the solar cell layer of the photovoltaic module according to an embodiment of this application. Figure 1 . Figure 2 This is a schematic diagram of the structure of the solar cell layer of the photovoltaic module according to an embodiment of this application. Figure 2 .

[0055] In one embodiment, the busbar includes a first edge busbar 11, a second edge busbar 12, and at least one interconnecting busbar disposed between the first edge busbar 11 and the second edge busbar 12; wherein the first edge busbar 11, the second edge busbar 12 and the interconnecting busbar are all provided with the groove 30, and at least one jumper 20 has both ends embedded and welded into the groove 30.

[0056] The busbar includes a first edge busbar 11 and a second edge busbar 12 disposed on both sides of the battery string, and an interconnecting busbar disposed between the first edge busbar 11 and the second edge busbar 12. The interconnecting busbar includes a first interconnecting busbar 131, a second interconnecting busbar 132, and a third interconnecting busbar 133.

[0057] The photovoltaic module includes three sets of cell strings, each set comprising four cell strings arranged in a matrix, each cell string containing multiple four-cell modules connected in series. Each set of cell strings has a first edge busbar 11 and a second edge busbar 12 on both sides. A first interconnect busbar 131 is located in the middle of the first set of cell strings, connecting the four cell strings in parallel with the first edge busbar 11 and the second edge busbar 12 to form the first set of cell strings. A second interconnect busbar 132 is located in the middle of the second set of cell strings, connecting the four cell strings in parallel with the first edge busbar 11 and the second edge busbar 12 to form the second set of cell strings. A third interconnect busbar 133 is located in the middle of the third set of cell strings, connecting the four cell strings in parallel with the first edge busbar 11 and the second edge busbar 12 to form the third set of cell strings.

[0058] The first edge busbar 11 and the second edge busbar 12 of the second battery string group are connected to the first edge busbar 11 and the second edge busbar 12 of the third battery string group, so that the second battery string group and the third battery string group are connected in series. One of the jumpers 20 is connected at both ends to the groove 30 of the first edge busbar 11 and the groove 30 of the second edge busbar 12 of the first battery string group, respectively; the jumper 20 can also be connected to the groove 30 of the second interconnecting busbar 132 to connect the third battery string group and the second battery string group in series.

[0059] Another jumper 20 is located between the second interconnect bus bar 132 and the third interconnect bus bar 133. The two ends of the jumper 20 are respectively connected to the grooves 30 of the first edge bus bar 11 of the second battery string group and the grooves 30 of the second edge bus bar 12 of the third battery string group.

[0060] By creating grooves 30 on the first edge busbar 11, the second edge busbar 12, and the interconnecting busbar, the connection thickness between the jumper 20 and the busbar is further reduced, ensuring that the electrical connection points between all cell strings inside the photovoltaic module are thinned and flattened, avoiding stress concentration caused by connection point protrusions, and improving the operational safety and reliability of the photovoltaic module.

[0061] In one embodiment, each battery string is formed by connecting multiple battery cells in series via conductive connectors; the battery cells are multi-cell batteries.

[0062] The solar cell is a multi-segmented cell, formed by dividing a complete solar cell along a direction perpendicular to the main grid line. Each solar cell can be divided into two or more segments, such as two-segment, three-segment, four-segment, six-segment, eight-segment, etc.

[0063] Conductive connectors are used to connect two adjacent solar cells in series. The conductive connectors are flat metal solder strips. The material of the conductive connectors can be copper core plated with tin. The conductive connectors are electrically connected to the main grid lines of the two adjacent solar cells through a soldering process, thereby realizing the series connection of the solar cells to form a solar cell string.

[0064] Because multi-cell batteries have a greater number of busbars and jumpers 20, there are more connection points. If traditional stacked welding methods are used, there will be more local protrusions, leading to more pronounced stress concentration. By creating grooves 30 on the busbars, the jumpers 20 are embedded and welded in place, effectively reducing local protrusions and avoiding the risk of stress concentration at low temperatures.

[0065] The solar cell is a gridless solar cell, with multiple fine grid lines on its surface. These fine grid lines are connected by a conductive adhesive film (POE film) covering the solar cell or by solder ribbons. The gridless structure eliminates the resistance of the grid itself and the contact resistance between the solder ribbon and the grid, thereby helping to reduce the series resistance of the photovoltaic module and improve the fill factor and output power.

[0066] Furthermore, the cells are divided along the extension direction parallel to the fine grid lines to form multi-segment cells. Each cell can be divided into two or more segments, such as two-segment, three-segment, four-segment, six-segment, eight-segment, etc.

[0067] In one embodiment, the width of the busbar is 3mm-10mm.

[0068] The width of the busbar is 3mm-10mm. More specifically, the width of the busbar is one of 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm. A wider busbar can carry a larger output current.

[0069] In one embodiment, the thickness of the busbar is 0.1mm-0.8mm.

[0070] The thickness of the busbar is 0.1mm-0.8mm. More specifically, the thickness of the busbar is one of 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm. The width and thickness of the busbar can be adjusted according to the dimensions of the jumper 20.

[0071] The aforementioned width and thickness ranges of the busbar ensure the strength of the busbar itself, facilitate the machining of grooves 30 on it, and reduce the machining difficulty of grooves 30; at the same time, without sacrificing electrical performance, the thickness of the connection is effectively reduced.

[0072] In one embodiment, the jumper 20 has a width of 3mm-15mm.

[0073] The width of the jumper 20 is 3mm-15mm. More specifically, the width of the jumper 20 is one of 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, or 15mm. The width of the jumper 20 is less than or equal to the width of the groove 30 on the busbar, ensuring that the jumper 20 can be embedded and providing space for solder filling. A wider jumper 20 can carry a larger bus current.

[0074] In one embodiment, the thickness of the jumper 20 is 0.1mm-0.5mm.

[0075] The thickness of the jumper 20 is 0.1mm-0.5mm. Further, the thickness of the jumper 20 is one of 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm. The depth of the groove 30 on the busbar is greater than or equal to the thickness of the jumper 20 to ensure a smooth connection.

[0076] The width and thickness range of the aforementioned jumper 20 optimizes its cross-sectional area, thereby improving its current carrying capacity and ensuring efficient current transmission. This prevents overheating or losses caused by excessively small jumper dimensions. Furthermore, the thickness range ensures the jumper 20 maintains basic flexibility while preventing excessive deformation when embedded in the groove 30 of the busbar, thus guaranteeing the connection strength between the jumper 20 and the busbar and improving the reliability of the photovoltaic module operation.

[0077] 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.

[0078] 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 in that, include: Multiple battery strings; Multiple busbars are arranged horizontally to connect adjacent battery strings in series; Multiple jumpers, each arranged longitudinally, are used to connect to the busbar; A groove is provided at the connection between the busbar and the jumper, and the jumper is embedded in the groove.

2. The photovoltaic module according to claim 1, characterized in that, The depth of the groove is greater than or equal to the thickness of the jumper wire.

3. The photovoltaic module according to claim 1 or 2, characterized in that, The groove is a through groove that extends along the length of the busbar and penetrates along the width of the busbar.

4. The photovoltaic module according to claim 1 or 2, characterized in that, The cross-section of the groove is rectangular, trapezoidal, or arc-shaped.

5. The photovoltaic module according to claim 1, characterized in that, The busbar includes a first edge busbar, a second edge busbar, and at least one interconnecting busbar disposed between the first edge busbar and the second edge busbar; wherein the first edge busbar, the second edge busbar, and the interconnecting busbar are all provided with the groove, and at least one jumper wire has both ends embedded and welded into the groove.

6. The photovoltaic module according to claim 1, characterized in that, Each of the battery strings is formed by connecting multiple battery cells in series through conductive connectors; the battery cells are multi-cell batteries.

7. The photovoltaic module according to claim 1, characterized in that, The width of the busbar is 3mm-10mm.

8. The photovoltaic module according to claim 1, characterized in that, The thickness of the busbar is 0.1mm-0.8mm.

9. The photovoltaic module according to claim 1, characterized in that, The width of the jumper is 3mm-15mm.

10. The photovoltaic module according to claim 1, characterized in that, The thickness of the jumper is 0.1mm-0.5mm.

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