A photovoltaic module

Abstract

The utility model relates to a kind of photovoltaic modules, including multiple battery string groups.The battery string group includes two adjacent battery strings, each battery string is formed by multiple cell pieces through welding band series connection, the first cell piece of the same side end of two battery strings is connected to the same first busbar to realize series connection, the back of the second cell piece of the same side end of two adjacent battery strings is simultaneously provided in the first busbar, and the second cell piece is contacted with the first busbar by insulation isolation layer;The welding band connecting the first busbar and the first cell piece front electrode starts from the front electrode, passes through the gap between the first cell piece and the second cell piece, and extends to the back of the second cell piece.The utility model sets the first busbar on the back of the second cell piece of battery string end, and the welding band connected to the front electrode of the first cell piece is connected to the first busbar by passing through the gap between the first and second cell pieces, which improves the appearance of the front of photovoltaic module.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic module manufacturing, and in particular to a photovoltaic module. Background Technology

[0002] In various application scenarios of photovoltaic (PV) modules, their appearance often has specific requirements. Especially in scenarios where both power generation and decorative functions are required, PV modules not only bear the responsibility of power generation but also play a crucial role in aesthetics. Therefore, while ensuring reliability, beautifying the module's appearance helps meet the diverse aesthetic needs of different scenarios. Currently, mass-produced PV modules have made many breakthroughs in appearance, with some products evolving from traditional transparent and colorless to those with rich colors, exquisite patterns, and even customizable shapes. Busbars are used to connect the various cell strings in a PV module. Commonly used busbars are often exposed on the light-receiving surface, making it difficult for their appearance to completely match the cells. This necessitates changes to the color scheme of the encapsulation material and the selection of special production materials, increasing production costs. Utility Model Content

[0003] In view of this, the present invention provides a photovoltaic module that solves or at least alleviates one or more of the above-mentioned problems and other problems existing in the prior art.

[0004] To achieve the aforementioned objective, this utility model provides a photovoltaic module, including multiple battery string groups, wherein each battery string group includes two adjacent battery strings, each battery string is formed by multiple battery cells connected in series by solder strips, the first battery cells at the same end of the two battery strings are connected in series to the same first busbar, the first busbar is also disposed on the back of the second battery cells at the same end of the two adjacent battery strings, and the second battery cells are in contact with the first busbar through an insulating isolation layer;

[0005] The solder strip connecting the first busbar to the front electrode of the first cell starts from the front electrode, passes through the gap between the first and second cells, and extends to the back of the second cell.

[0006] In the photovoltaic module described above, optionally, the solder strip connecting the first busbar to the back electrode of the first cell at the end of the cell string starts from the back electrode and extends parallel to the back of the second cell.

[0007] In the photovoltaic module described above, optionally, the welding positions of the first busbar and the solder strip are both located on the back of the solar cell.

[0008] In the photovoltaic module described above, optionally, the solder strip connecting the first busbar and the first cell has the insulating isolation layer disposed on its surface.

[0009] In the photovoltaic module described above, the insulating layer may optionally be made of epoxy resin, polytetrafluoroethylene, aluminum oxide, or titanium dioxide.

[0010] In the photovoltaic module as described above, optionally, the insulating layer is deposited or bonded to the non-welded surface of the first busbar.

[0011] In the photovoltaic module described above, optionally, the battery string group further includes a second busbar and a junction box. The first busbar is connected to one end of the battery string, and two second busbars are respectively connected to the other end of the battery string. The junction box is connected between the second busbars for outputting and storing electrical energy.

[0012] Optionally, in the photovoltaic module described above, the photovoltaic module includes a plurality of symmetrical battery string groups arranged longitudinally, with a junction box provided between adjacent symmetrical battery string groups, and the symmetrical battery string group is composed of two battery string groups connected in parallel.

[0013] In the photovoltaic module described above, optionally, two battery strings in the symmetrical battery string group are horizontally aligned and arranged symmetrically. In the symmetrical battery string group, the inner ends of every two horizontally aligned battery strings are connected to an independent second busbar. The second busbars are connected to each other through the junction box. Both the second busbar and the junction box are located on the back of the battery cell.

[0014] In the photovoltaic module described above, optionally, the front color of the photovoltaic module is the same as the front color of the cells in the battery string.

[0015] This invention improves the aesthetics of the front of the photovoltaic module by placing the first busbar on the back of the second cell at the end of the battery string and connecting the solder strip connected to the front electrode of the first cell through the gap between the first and second cells to the first busbar. Attached Figure Description

[0016] The disclosure of this utility model will become more apparent with reference to the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings:

[0017] Figure 1 This is a side view of one embodiment of the battery string of this utility model;

[0018] Figure 2 This is a front view of the back of an embodiment of the photovoltaic module of this utility model;

[0019] Figure 3 yes Figure 2 Front view of the Chinese embodiment;

[0020] Figure 4 A schematic diagram of the cross-sectional structure for setting up an insulating isolation layer.

[0021] Reference numerals: 1-Battery string; 2-Battery cell; 3-First busbar; 4-Insulating layer; 5-Gap; 6-Junction box; 7-Battery string assembly; 8-Second busbar; 9-Solder strip; 10-Busbar; 11-Symmetrical battery string assembly. Detailed Implementation

[0022] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of a photovoltaic module of the present invention will be described below by way of example; however, all descriptions should not be construed as limiting the present invention in any way.

[0023] For any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various drawings, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of the description herein.

[0024] 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 with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0025] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", 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.

[0026] The existing photovoltaic module includes a cell string structure as follows: Figure 1 As shown, multiple solar cells 2 are arranged side by side. The front of the solar cell 2 is the light-receiving surface, and the back is the non-light-receiving surface. In actual use, the front of the solar cell is usually the positive electrode, and the back is the negative electrode. To connect the solar cells, as shown in the figure, except for the solar cell at the far right, a solder ribbon 9 is led out from the front of each solar cell and extends to the back of the adjacent solar cell on the right side, thereby connecting the solar cells in series to form a solar cell string 1. In the figure, the right end of the solar cell string 1 is the positive electrode, represented by a "+", and the left end is the negative electrode, represented by a "-". A certain distance is left between adjacent solar cells to form a gap 5 through which the aforementioned solder ribbon can pass.

[0027] It should be noted that in this invention, the light-receiving surface (front) of the solar cells is always the positive electrode, and the back surface is always the negative electrode. This should not be considered a limitation of this photovoltaic module, but is merely an example. The orientation of the solar cells can also be reversed so that the negative electrode faces the light-receiving surface.

[0028] To connect two cell strings, a busbar 10 is typically installed on the outer side of the cell string end, with solder strips extending from the end cells to the busbar 10. For example, if the end of the cell string is the positive terminal, the solder strip 9 extends from the front (positive) side of the end cell; if it is the negative terminal, it extends from the back (negative) side. Currently, the busbars in photovoltaic modules are located on the outer side of the cell string, exposed on the light-receiving surface (front) of the string, which affects the color uniformity of the light-receiving surface of the photovoltaic module. To achieve color uniformity in photovoltaic modules, the color scheme of the encapsulation materials for the cells and busbars needs to be changed. This not only limits the selection of raw materials and complicates the production and encapsulation processes, but may also affect the reliability of the welding fabrication of crystalline silicon substrate solar cell modules, creating a dilemma where it is difficult to balance the decorative and power generation performance of photovoltaic modules.

[0029] To address the aforementioned problems, this utility model proposes a photovoltaic module comprising multiple battery string groups 7. Each battery string group 7 includes two adjacent battery strings 1. For example... Figure 2 As shown, two battery strings 1 can be arranged horizontally parallel to each other, with their electrodes facing opposite directions. Each battery string 1 is formed by connecting multiple battery cells 2 in series via solder ribbons 9. The first battery cell at one end of each of the two battery strings has a solder ribbon extended from it and connected to the same first busbar 3, thus achieving series connection. The first busbar 3 is located on one side of the battery string 1 and is fixedly mounted on the back of the battery cell on that side, thus concealing it from the light-receiving surface. This reduces factors affecting the appearance of the photovoltaic module's front side, makes color consistency easier, and minimizes changes to the color scheme of the battery cells and busbar encapsulation materials during production, thereby improving production quality.

[0030] The first busbar 3 is connected to the solder strip 9 extending from the first cell at the same end of both cell strings. The first busbar is then bent and wrapped around the back of the cell and fixed, thus concealing the busbar. However, in photovoltaic modules using this implementation, the solder strip is prone to stress concentration after bending, damaging the internal structure of the solder strip and affecting its lifespan. Furthermore, the bent busbar is more susceptible to detachment due to vibration or external impact, reducing the reliability of the connection between cell strings.

[0031] To improve this shortcoming, the first busbar is simultaneously positioned on the back side of the second cell 2 at the end of the aforementioned battery string and fixedly connected. Since the electrode directions of the two battery strings in the battery string assembly are opposite, the polarities of the battery string ends on the same side are different, and the electrodes from which the solder ribbon is drawn from the first cell are also different. Specifically, since the front of the cell is positive and the back is negative, when the end of the battery string 1 is positive, the solder ribbon should be drawn from the front electrode of the first cell. This solder ribbon starts from the front electrode, passes through the gap 5 between the first and second cells, extends to the back of the second cell, and is welded to the first busbar there. If the end of the battery string is negative, the solder ribbon is drawn from the back electrode of the first cell at that end, extending parallel to the direction of the battery string to the back of the second cell, and then welded to the first busbar there. Compared to the technical solution of bending the solder ribbon 9, the design of this utility model improves the reliability and durability of the connection structure between battery strings, thereby increasing the lifespan of the photovoltaic module. It should be noted that… Figure 2 Battery string 1 in the diagram schematically includes four battery cells. In practical applications, battery string 1 can contain any number of battery cells as needed.

[0032] Since the back of the second battery cell is the negative electrode, and the first busbar 3 is a conductor and is attached to the back of the cell, and the second battery cell is connected in series with the first battery cell, the first busbar and the back electrode (negative electrode) of the second battery cell 2 need to be in contact through the insulating layer 4. The insulating layer 4 prevents the first battery cell or both the first and second battery cells at this end of the battery string from being short-circuited.

[0033] Specifically, the insulating layer can be made of polymer materials such as epoxy resin and polytetrafluoroethylene, or metal oxides such as alumina and titanium dioxide, resulting in good insulation performance and wear resistance. Epoxy resin, in particular, has good adhesion and can be uniformly coated onto the electrode surface through spraying, brushing, or other methods, forming a robust insulating layer after curing. Alternatively, a thin film of alumina can be deposited on the surface of the electrode or the first busbar using physical or chemical vapor deposition methods, giving the electrode surface good chemical stability and insulation properties. For the first busbar 3, an insulating layer can be deposited or adhered to its non-welded surfaces. These surfaces, whether used to connect the battery cell electrodes or exposed to air, provide insulation and reduce the probability of short circuits.

[0034] Because the cells are connected in series in the battery string, there is already a through gap 5 between the first and second cells at the end of the battery string (e.g., Figure 1The solder strip (shown) is used. As mentioned earlier, when the first busbar is placed on the back of the second cell, there is a need to additionally provide solder strips to connect the front electrode of the first cell and the first busbar. In this case, both solder strips pass through the gap 5 with a certain angle. Although they can be staggered by a certain distance to avoid contact, due to processing errors, it is difficult to completely prevent the two solder strips from contacting each other, thereby short-circuiting the first cell, causing safety hazards, and reducing product reliability. Therefore, as an alternative embodiment, insulating glue can be injected into the gap 5 between the first and second cells at the end of the battery string, or the aforementioned insulating isolation layer can be provided on the surface of the solder strip passing through this area, or the insulating isolation layer can be provided only on the surface of the solder strip connecting the first busbar and the first cell, thereby improving product reliability.

[0035] Since the first busbar is fixed to the back of the solar cell, and the welding positions of the first busbar and the solder strip are both located on the back of the solar cell, a better shading effect is achieved. From the light-receiving side, the welding positions will not affect the overall appearance of the photovoltaic module.

[0036] The battery string assembly 7 has two battery strings 1. A first busbar 3 is located at one end of the battery strings to connect the first battery cell at each end. A second busbar 8 and a junction box 6 are located at the other end of the battery strings to connect the battery cell at that end. The two second busbars are connected to the ends of the two battery strings respectively, one as the positive terminal and the other as the negative terminal. The junction box 6 is connected between the two second busbars 8, thereby discharging and storing electrical energy. The first busbar 3, the second busbar 8, and the junction box 6 connect the two battery strings 1 in series to obtain a higher output voltage.

[0037] This invention also proposes a photovoltaic module comprising multiple longitudinally arranged symmetrical battery string groups 11. Each symmetrical battery string group 11 includes two parallel battery string groups 7. The two battery string groups 7 are laterally aligned and symmetrically arranged. Within each symmetrical battery string group, two battery strings are arranged longitudinally, with the strings in each group laterally aligned in two rows and having opposite electrode directions. Every two laterally aligned battery strings 1 have the same polarity at their inward-facing ends and are connected to the same independent second busbar 8. The two rows of battery strings 1 are connected to two different second busbars, and the two second busbars 8 are connected via a junction box 6. By sharing the second busbar 8 and the junction box 6, the two battery string groups improve the space utilization of the photovoltaic module and reduce its structural weight. The second busbar 8 and the junction box 6 can be located on the back of the first battery cell at the inner end of the battery string. In this case, the polarity of the battery string at this end is opposite to the polarity of the back of the battery cell (in this embodiment, the polarity of the battery string at this end is positive). Therefore, an insulating layer needs to be provided between the second busbar and the back of the battery cell to avoid short-circuiting the battery cell.

[0038] The first busbar 3 is distributed on both sides of the symmetrical battery string group 11. Through sharing the second busbar 8, the two battery strings 7 in the symmetrical battery string group 11 are connected in parallel. The upper and lower symmetrical battery string groups 11 are connected via a junction box 6 for collecting electrical energy. The first busbar 3 of the battery strings 7 in different symmetrical battery string groups 11 are not connected to each other. The parallel battery strings 7 can increase the output current of the symmetrical battery string group 11 and its associated photovoltaic module, meeting the load requirements with high current demands, and also improving reliability, preventing damage to one battery string from affecting the overall performance of the module. Figure 3 As can be seen in the magnified view, only a small portion of the first busbar 3 is visible through the gap between the upper and lower cells on the light-receiving surface (front) of the photovoltaic module. Furthermore, in the middle of the symmetrical cell string group 11, both the second busbar 8 and the junction box 6 are located on the back of the cells. Figure 3 The area is indicated by a dashed line. As can be seen, the second busbar 8 and most of the junction box are obscured by the solar cells, and are essentially not exposed on the light-receiving surface. This design not only improves the aesthetics of the photovoltaic module's light-receiving surface but also saves front-side space, increasing the effective area ratio.

[0039] By arranging symmetrical battery string groups 11, the photovoltaic module of this utility model has neatly arranged battery cells. Furthermore, because the first busbar is fixedly set on the back of the battery cells, the color of the light-receiving surface (front) of the photovoltaic module is the same as the color of the front of the battery cells, thus achieving uniformity of the light-receiving surface color, enhancing its aesthetics, reducing the difficulty of selecting production materials and packaging color schemes, and lowering costs.

[0040] Figure 4 A schematic diagram of the cross-sectional structure for setting up an insulating isolation layer. Figure 4 It could also be Figure 3 The enlarged top view of the embodiment at point A shows the hierarchical structure at the connection between the first busbar and the solar cell. From top to bottom, the photovoltaic module is divided into five layers: the first layer is a solder ribbon extending from the positive electrode of the first solar cell at the end of the cell string and connecting to the first busbar 3 in the second layer; the third layer is an insulating layer; the fourth layer is the solar cell 2, with its negative electrode facing upwards and an insulating layer between it and the first busbar, and its positive electrode facing downwards; the fifth layer, solder ribbon 9, is welded to the positive electrode of the solar cell. This insulating layer design ensures that no short circuit occurs between the first busbar and the first and second solar cells.

[0041] This utility model also proposes a method for manufacturing a photovoltaic module, the steps of which include:

[0042] Step A, preparing for welding. The solar cells are arranged in rows, and the front and back of the solar cells have not yet been welded with solder strips.

[0043] Step B, welding the solder strips. Adjacent solar cells are connected using solder strips.

[0044] Step C: Install the first busbar. Attach the first busbar to the back of the second cell at the end of the battery string, install an insulating layer, and extend solder ribbons from the first cell through the gaps between the cells to the first busbar on the back of the second cell, thus welding the two battery strings together to form a battery string assembly.

[0045] Step D, Layout. First, arrange the two battery string groups horizontally and mirror-symmetrically, with the battery strings aligned horizontally and the electrodes of the same polarity in the two horizontally aligned battery string groups facing each other. Second, set a second bus bar between the two horizontally aligned battery string groups, and lead solder strips from the battery cells at the ends of the battery strings on the left and right sides to connect to the second bus bar. Next, set a junction box between the upper and lower second bus bars to form a complete symmetrical battery string group 11. Finally, arrange the symmetrical battery string groups 11 vertically, and set a junction box between the second bus bars of the upper and lower adjacent symmetrical battery string groups 11.

[0046] Step E involves lamination and other encapsulation processes. The arranged symmetrical cell strings are then encapsulated to form a complete photovoltaic module.

[0047] The technical scope of this utility model is not limited to the contents of the above description. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the scope of this utility model.

Claims

1. A photovoltaic module comprising a plurality of strings (7) of cells, characterized in that, The battery string group (7) includes two adjacent battery strings (1). Each battery string (1) is formed by multiple battery cells (2) connected in series by solder strips (9). The first battery cell (2) at the same end of the two battery strings (1) is connected in series to the same first bus bar (3). The first bus bar (3) is also provided on the back of the second battery cell (2) at the same end of the two adjacent battery strings (1). The second battery cell (2) is in contact with the first bus bar (3) through an insulating isolation layer (4). The solder strip connecting the first busbar (3) to the front electrode of the first battery cell (2) starts from the front electrode, passes through the gap (5) between the first battery cell (2) and the second battery cell (2), and extends to the back of the second battery cell (2).

2. The photovoltaic module of claim 1, wherein, The solder strip (9) connecting the first busbar (3) to the back electrode of the first battery cell (2) at the end of the battery string (1) starts from the back electrode and extends parallel to the back of the second battery cell (2).

3. The photovoltaic module of claim 1, wherein, The welding positions of the first busbar (3) and the welding strip are both located on the back of the battery cell (2).

4. The photovoltaic module of claim 1, wherein, The solder strip connecting the first busbar (3) and the first battery cell (2) has the insulating isolation layer (4) disposed on its surface.

5. The photovoltaic module of claim 1 or 4, wherein, The insulating layer (4) is made of epoxy resin, polytetrafluoroethylene, aluminum oxide or titanium dioxide.

6. The photovoltaic module as described in claim 1, characterized in that, The insulating layer (4) is deposited or adhered to the non-welded surface of the first busbar (3).

7. The photovoltaic module as described in claim 1, characterized in that, The battery string group (7) also includes a second busbar (8) and a junction box (6). The first busbar (3) is connected to one end of the battery string (1), and the two second busbars (8) are respectively connected to the other end of the battery string (1). The junction box (6) is connected between the second busbars (8) for outputting and storing electrical energy.

8. The photovoltaic module as described in claim 1, characterized in that, The photovoltaic module includes multiple symmetrical battery strings (11) arranged longitudinally, and a junction box (6) is provided between adjacent symmetrical battery strings (11). The symmetrical battery string (11) is composed of two battery strings (7) connected in parallel.

9. The photovoltaic module as described in claim 8, characterized in that, The two battery strings (7) in the symmetrical battery string group (11) are horizontally aligned and arranged symmetrically. In the symmetrical battery string group (11), the battery cells (2) of each two horizontally aligned battery strings (1) are connected together to an independent second busbar (8). The second busbars (8) are connected to each other through the junction box (6). The second busbars (8) and the junction box (6) are both located on the back of the battery cells (2).

10. The photovoltaic module as described in claim 8, characterized in that, The front color of the photovoltaic module is the same as the front color of the cell (2) in the battery string (7).

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