Photovoltaic module and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a photovoltaic module and a photovoltaic system. The photovoltaic module comprises 2N battery string groups which are connected in series, each battery string group comprises m battery strings which are connected in parallel, and each battery string comprises a plurality of battery pieces which are connected in series; wherein the nth battery string group and the (n + 1) th battery string group which are connected in series form a series structure, and the two ends of the series structure are not provided with diodes; the battery piece comprises a first doping layer and a second doping layer which are opposite in polarity. The battery piece further comprises an electric leakage composite contact structure which is at least partially arranged between the first doping layer and the second doping layer. Therefore, a bypass diode can be replaced to form a heat dissipation point in the battery piece through the electric leakage composite contact structure, the influence of hot spots is reduced or even eliminated, and the performance and the safety of the photovoltaic module are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a photovoltaic module and a photovoltaic system. Background Art

[0002] A photovoltaic module is a semiconductor device that converts sunlight energy directly into electrical energy. In related technologies, photovoltaic cell modules are usually composed of a battery array consisting of multiple cells. In order to effectively control the risk of hot spots, solar cells usually adopt a bypass diode design to reduce the leakage current of the cell, thereby controlling the heating power of the leakage point. At the same time, the photovoltaic module is divided into the upper and lower sides, and a middle bus bar is set at the center line of the module to connect the battery string units connected in series on the upper and lower sides in parallel to draw out current. The middle bus bar and diode used in this way will greatly occupy the module area, which reduces the module conversion efficiency. Based on this, how to avoid the reduction of module conversion efficiency has become an urgent problem to be solved. Utility Model Content

[0003] The present application provides a photovoltaic module and a photovoltaic system, aiming to solve the problem that the busbars and diodes in the middle of the photovoltaic module greatly occupy the module area, thereby reducing the module conversion efficiency.

[0004] The photovoltaic modules provided in this application include:

[0005] 2N battery string groups connected in series, where N is a positive integer; each battery string group includes m battery strings connected in parallel, each battery string group includes the same number of battery strings, and m is an integer greater than or equal to 2; each battery string includes a plurality of battery cells connected in series;

[0006] The nth battery string group and the n+1th battery string group connected in series form a series structure, no diodes are provided at both ends of the series structure, and n is an odd number;

[0007] The cell comprises a first doping layer and a second doping layer, wherein the second doping layer has a polarity opposite to that of the first doping layer;

[0008] The battery cell further includes a leakage composite contact structure, which is at least partially disposed between the first doping layer and the second doping layer.

[0009] Furthermore, the conductivity type of the leakage composite contact structure is opposite to that of the first doping layer, and the leakage composite contact structure and the second doping layer are of the same conductivity type and are continuous as one.

[0010] Furthermore, the conductivity type of the leakage composite contact structure is opposite to that of the second doping layer, and the leakage composite contact structure and the first doping layer have the same conductivity type and are continuous as one.

[0011] Furthermore, when N is equal to 1 and each battery string group includes two battery strings, the first battery string group and the second battery string group connected in series form a first series structure;

[0012] No diodes are provided at both ends of the first series structure;

[0013] The electrode lead-out end of the first battery string group and the electrode lead-out end of the second battery string group are located at the same side end of the photovoltaic module.

[0014] Furthermore, when N is equal to 2 and each battery string group includes two battery strings, the first battery string group and the second battery string group connected in series form a second series structure, and the third battery string group and the fourth battery string group connected in series form a third series structure;

[0015] No diodes are provided at both ends of the second series structure and at both ends of the third series structure;

[0016] The electrode lead-out end of the first battery string group and the electrode lead-out end of the fourth battery string group are located at the same side end of the photovoltaic module.

[0017] Furthermore, the photovoltaic module further comprises: a bus bar, the bus bar being located at an end of the photovoltaic module in a first direction and being laid along a second direction, the first direction being an arrangement direction of a plurality of cells included in the cell string, the second direction being perpendicular to the first direction;

[0018] The bus bar is not provided at the center line of the photovoltaic assembly in the first direction.

[0019] Furthermore, the bus bar includes: a first bus bar and a second bus bar; the first bus bar is located on the backlight side of the photovoltaic component and is arranged at the end close to the upper side of the photovoltaic component in the first direction, and the second bus bar is located on the backlight side of the photovoltaic component and is arranged at the end close to the lower side of the photovoltaic component in the first direction.

[0020] Furthermore, the photovoltaic module further comprises: an insulating strip, the insulating strip being arranged on the backlight surface of the photovoltaic module and laid along the second direction;

[0021] The first bus bar is arranged along the second direction on a side of the insulating bar away from the battery string group, and the first bus bar covers the insulating bar;

[0022] The insulating strip is provided with a through hole or a notch, and the welding strip is connected to the first bus bar through the through hole or the notch. The welding strip is arranged on the backlight surface of the photovoltaic module and laid along the first direction. The welding strip is used to connect the grid lines on the battery string.

[0023] Furthermore, the ratio of the total area of ​​the 2N battery strings to the total area of ​​the photovoltaic module is 0.93-0.99.

[0024] The photovoltaic system provided in the embodiment of the present application includes the photovoltaic module described in the above embodiment, wherein the electrode lead-out end of the first battery string group in the photovoltaic module is connected to the positive terminal of the photovoltaic module, and the electrode lead-out end of the last battery string group in the photovoltaic module is connected to the negative terminal of the photovoltaic module.

[0025] In a photovoltaic module according to an embodiment of the present application, the photovoltaic module includes: 2N battery strings connected in series, where N is a positive integer; each battery string includes m battery strings connected in parallel, each battery string includes the same number of battery strings, and m is an integer greater than or equal to 2; each battery string includes a plurality of battery cells connected in series; the nth battery string and the n+1th battery string connected in series form a series structure, wherein no diodes are provided at either end of the series structure, and n is an odd number; the battery cell includes a first doped layer and a second doped layer, wherein the second doped layer has an opposite polarity to the first doped layer; and the battery cell further includes a leakage composite contact structure, which is at least partially disposed between the first doped layer and the second doped layer. Thus, since the number of battery strings is always an even number, the electrode lead terminals of the first battery string and the electrode lead terminals of the last battery string are ensured to be located on the same side of the photovoltaic module, thereby achieving a high-efficiency battery module with a simple and reliable structure. The leakage composite contact structure forms a heat dissipation point within the battery cell, reducing or even eliminating the effects of hot spots, thereby improving the power generation efficiency and safety of the photovoltaic module. Furthermore, eliminating diodes and busbars at the centerline of the PV module reduces module costs, reduces the area of ​​​​blocking, improves the photovoltaic module's photoelectric conversion efficiency, and avoids hidden cracks and damage caused by busbar series connection. The absence of diodes and, consequently, a junction box improves aesthetics and facilitates installation and maintenance of the PV module. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a photovoltaic module according to an embodiment of the present application;

[0027] Figure 2 is another structural schematic diagram of a photovoltaic module according to an embodiment of the present application;

[0028] Figure 3 This is another structural diagram of a photovoltaic module according to an embodiment of the present application;

[0029] Figure 4 is another structural schematic diagram of a photovoltaic module according to an embodiment of the present application;

[0030] Figure 5 is another structural schematic diagram of a photovoltaic module according to an embodiment of the present application;

[0031] Figure 6 is another structural schematic diagram of a photovoltaic module according to an embodiment of the present application;

[0032] Figure 7 is another structural schematic diagram of a photovoltaic module according to an embodiment of the present application;

[0033] Figure 8 It is a structural diagram of a photovoltaic system according to an embodiment of the present application.

[0034] Description of main component symbols:

[0035] Photovoltaic module 100, battery string group 10, battery string 11, battery cell 12, first doped layer 21, second doped layer 22, leakage composite contact structure 30, first battery string group 41, second battery string group 42, third battery string group 43, fourth battery string group 44, first series structure 51, second series structure 52, third series structure 53, bus bar 60, first bus bar 61, second bus bar 62, photovoltaic system 200. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are merely used to explain the present application and are not intended to limit the present application.

[0037] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They 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, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this application.

[0038] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0040] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0041] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art will appreciate the application of other processes and / or the use scenarios of other materials.

[0042] In the related art, photovoltaic cell modules are usually composed of a cell array composed of multiple cells. In order to effectively control the risk of hot spots, solar cells usually adopt a bypass diode design to reduce the leakage current of the cell, thereby controlling the heat generation power of the leakage point. At the same time, the photovoltaic module is divided into upper and lower sides, and a central bus bar is set at the center line of the module to connect the cell strings connected in series on the upper and lower sides in parallel to draw out the current. The central bus bar and diode used in this way will greatly occupy the module area, resulting in a decrease in the module conversion efficiency. In this application, a leakage composite contact structure is used to form a heat dissipation point inside the cell, reducing or even eliminating the impact of hot spots, thereby improving the power generation efficiency and safety of the photovoltaic module. At the same time, no diode is set, and no bus bar is set at the center line of the photovoltaic module, which can reduce the cost of the module, reduce the area of ​​the module being blocked, improve the photoelectric conversion efficiency of the photovoltaic module, and avoid the problems of hidden cracks and damage caused by the series connection of bus bars. No diode is required, and no junction box is required, which improves the aesthetics and facilitates the installation and maintenance of the photovoltaic module.

[0043] Example 1

[0044] See also Figures 1 to 3 In the photovoltaic module 100 of the embodiment of the present application, the photovoltaic module 100 includes: 2N battery string groups 10 connected in series, where N is a positive integer; each battery string group 10 includes m battery strings 11 connected in parallel, and each battery string group 10 includes the same number of battery strings 11, where m is an integer greater than or equal to 2; each battery string 11 includes a plurality of battery cells 12 connected in series; the nth battery string group 10 and the (n+1)th battery string group 10 connected in series form a series structure, and no diodes are provided at both ends of the series structure, and n is an odd number; the battery cell 12 includes a first doping layer 21 and a second doping layer 22, and the second doping layer 22 has an opposite polarity to the first doping layer 21; the battery cell 12 also includes a leakage composite contact structure 30, and the leakage composite contact structure 30 is at least partially provided between the first doping layer 21 and the second doping layer 22.

[0045] In the photovoltaic module 100 of the embodiment of the present application, the photovoltaic module 100 includes: 2N battery string groups 10 connected in series, where N is a positive integer; each battery string group 10 includes m battery strings 11 connected in parallel, and each battery string group 10 includes the same number of battery strings 11, where m is an integer greater than or equal to 2; each battery string 11 includes a plurality of battery cells 12 connected in series; the nth battery string group 10 and the n+1th battery string group 10 connected in series form a series structure, and no diodes are provided at both ends of the series structure, and n is an odd number; the battery cell 12 includes a first doping layer 21 and a second doping layer 22, and the second doping layer 22 has an opposite polarity to the first doping layer 21; the battery cell 12 also includes a leakage composite contact structure 30, and the leakage composite contact structure 30 is at least partially provided between the first doping layer 21 and the second doping layer 22. In this way, since the number of battery string groups 10 is always an even number, it is possible to ensure that the electrode lead-out terminal of the first battery string group 41 and the electrode lead-out terminal of the last battery string group 10 are both located at the same side end of the photovoltaic module 100, which can realize a high-efficiency battery module with a simple and reliable structure. The leakage composite contact structure 30 forms a heat dissipation point inside the battery cell 12, reducing or even eliminating the impact of hot spots, thereby improving the power generation efficiency and safety of the photovoltaic module 100. At the same time, diodes are no longer provided, and busbars 60 are no longer provided at the center line position of the photovoltaic module 100, which can reduce the cost of the module, reduce the area of ​​the module being blocked, improve the photoelectric conversion efficiency of the photovoltaic module 100, and avoid the problems of hidden cracks and damage caused by the series connection of the busbars 60. There is no need to provide diodes, and thus there is no need to provide a junction box, which improves the aesthetics and facilitates the installation and maintenance of the photovoltaic module 100.

[0046] Specifically, a number of battery cells 12 are connected in series to form a battery string 11. In other words, the battery string 11 can be regarded as a whole composed of a number of battery cells 12 connected in series, and each battery string 11 contains the same number of battery cells 12. The battery string group 10 refers to a whole composed of at least two battery strings 11 connected in parallel, and each battery string group 10 contains the same number of battery strings 11, which is m (m is an integer greater than or equal to 2). It should be noted that in order to ensure that the electrode lead-out end of the first battery string group 41 and the electrode lead-out end of the last battery string group 10 are located at the same side end of the photovoltaic module 100, 2N (N is a positive integer) battery string groups 10 need to be connected in series. In other words, when the number of battery string groups 10 is an odd number, the electrode lead-out end of the first battery string group 41 and the electrode lead-out end of the last battery string group 10 will be led out from the ends on different sides of the photovoltaic module 100.

[0047] Furthermore, every two battery string groups 10 can form a series structure, that is, the positive and negative electrodes of the nth (n is an odd number and n is less than 2N) battery string group 10 and the n+1th battery string group 10 in the 2N battery string groups 10 can be connected to form a series structure. For example, when n is equal to 1, the first battery string group 41 and the second battery string group 42 are connected in series; when n is equal to 3, the third battery string group 43 and the fourth battery string group 44 are connected in series; when n is equal to 5, the fifth battery string group 10 and the sixth battery string group 10 are connected in series; when n is equal to 7, the seventh battery string group 10 and the eighth battery string group 10 are connected in series, and so on.

[0048] In addition, no diodes are provided at both ends of the series structure consisting of the nth battery string group 10 and the n+1th battery string group 10. Instead, a leakage composite contact structure 30 is provided between the first doped layer 21 and the second doped layer 22 of the battery cell 12, and the leakage composite contact structure 30 replaces the traditional bypass diode as a heat dissipation point.

[0049] Furthermore, the cell 12 includes a first doped layer 21 and a second doped layer 22 of opposite polarity. A leakage composite contact structure 30 is at least partially disposed between the first doped layer 21 and the second doped layer 22, allowing the leakage composite contact structure 30 to at least partially connect the first doped layer 21 and the second doped layer 22 to form a leakage point, facilitating heat dissipation. Thus, the leakage composite contact structure 30 forms a heat dissipation point within the cell 12, replacing the traditional diode heat dissipation point. This reduces or even eliminates the effects of hot spots, improves the power generation efficiency and safety of the photovoltaic module 100, and reduces module costs and the area of ​​​​blockage.

[0050] Furthermore, the elimination of diodes and busbar 60 at the centerline of photovoltaic module 100 reduces module cost, reduces the area of ​​module obstruction, improves the photovoltaic conversion efficiency of photovoltaic module 100, and avoids potential cracking and damage caused by serial connection of busbar 60. The elimination of diodes and, consequently, the need for a junction box improves aesthetics and facilitates installation and maintenance of photovoltaic module 100.

[0051] Example 2

[0052] See also Figure 1 and Figure 2 In some optional embodiments, the conductivity type of the leakage composite contact structure 30 is opposite to that of the first doped layer 21 , and the leakage composite contact structure 30 and the second doped layer 22 have the same conductivity type and are continuous as one.

[0053] This allows current to flow more smoothly between the leakage composite contact structure 30 and the second doped layer 22, improving heat dissipation and increasing reliability. Furthermore, during the manufacturing process of the cell 12, the leakage composite contact structure 30 and the second doped layer 22 can be manufactured simultaneously, simplifying the manufacturing process of the cell 12.

[0054] Specifically, the leakage composite contact structure 30 and the second doped layer 22 are a continuous whole, a seamless or almost seamless whole continuous structure, and the physical and chemical properties of the leakage composite contact structure 30 and the second doped layer 22 remain consistent at the connection.

[0055] Furthermore, the conductivity type of the continuous structure of the leakage composite contact structure 30 and the second doped layer 22 can be the same and both are P-type (positive electrode containing more holes), in which case the conductivity type of the first doped layer 21 can be N-type (negative electrode containing more free electrons); alternatively, the conductivity type of the continuous structure of the leakage composite contact structure 30 and the second doped layer 22 can both be N-type, in which case the conductivity type of the first doped layer 21 can be P-type. The embodiments of the present application do not limit the specific conductivity types of the first doped layer 21 and the leakage composite contact structure 30 and the second doped layer 22, as long as the leakage composite contact structure 30 and the second doped layer 22 have the same conductivity type and are opposite to the conductivity type of the first doped layer 21.

[0056] Furthermore, the first doping layer 21 and the second doping layer 22 of different conductive types can be at least partially connected together through the leakage composite contact structure 30 to form a leakage point, thereby reducing the leakage current of the battery cell 12, thereby controlling the heating power of the leakage point, reducing or even eliminating the impact of hot spots, and improving the power generation efficiency and safety of the photovoltaic module 100.

[0057] Example 3

[0058] See also Figure 1 and Figure 3 In some optional embodiments, the conductivity type of the leakage composite contact structure 30 is opposite to the conductivity type of the second doping layer 22 , and the leakage composite contact structure 30 and the first doping layer 21 have the same conductivity type and are continuous as one.

[0059] This allows current to flow more smoothly between the leakage composite contact structure 30 and the first doped layer 21, improving heat dissipation and increasing reliability. Furthermore, during the manufacturing process of the cell 12, the leakage composite contact structure 30 and the first doped layer 21 can be manufactured simultaneously, simplifying the manufacturing process of the cell 12.

[0060] Specifically, the leakage composite contact structure 30 and the first doped layer 21 are a continuous whole, a seamless or almost seamless whole continuous structure, and the physical and chemical properties between the leakage composite contact structure 30 and the first doped layer 21 remain consistent at the connection.

[0061] Furthermore, the leakage composite contact structure 30 and the continuous structure of the first doped layer 21 can have the same conductivity type and both are P-type, in which case the conductivity type of the second doped layer 22 can be N-type; alternatively, the leakage composite contact structure 30 and the continuous structure of the first doped layer 21 can both be N-type, in which case the conductivity type of the second doped layer 22 can be P-type. The embodiments of the present application do not limit the specific conductivity types of the second doped layer 22 and the leakage composite contact structure 30 and the first doped layer 21, as long as the leakage composite contact structure 30 has the same conductivity type as the first doped layer 21 and the opposite conductivity type to the second doped layer 22.

[0062] Furthermore, the first doping layer 21 and the second doping layer 22 of different conductive types can be at least partially connected together through the leakage composite contact structure 30 to form a leakage point, thereby reducing the leakage current of the battery cell 12, thereby controlling the heating power of the leakage point, reducing or even eliminating the impact of hot spots, and improving the power generation efficiency and safety of the photovoltaic module 100.

[0063] Example 4

[0064] See also Figure 4 and Figure 5 In some optional embodiments, when N is equal to 1 and each battery string group 10 includes two battery strings 11, the first battery string group 41 and the second battery string group 42 connected in series form a first series structure 51;

[0065] No diodes are provided at both ends of the first series structure 51;

[0066] The electrode lead-out end of the first battery string group 41 and the electrode lead-out end of the second battery string group 42 are located at the same end portion of the photovoltaic module 100 .

[0067] In this way, several cell strings 11 are connected in series to form a cell string group 10, and several cell string groups 10 are connected in series to form a series structure. Furthermore, the elimination of diodes can reduce module costs, reduce the area of ​​module obstruction, and improve the photoelectric conversion efficiency of the photovoltaic module 100. Furthermore, the need for a junction box is eliminated, improving the aesthetics and facilitating the installation and maintenance of the photovoltaic module 100.

[0068] Specifically, taking each battery string group 10 as an example, which includes two battery strings 11, the photovoltaic module 100 includes 2N battery strings 10 connected in series, where N is a positive integer. When N is equal to 1, the photovoltaic module 100 includes two battery strings 10 connected in series, that is, the photovoltaic module 100 includes a first battery string group 41 and a second battery string group 42 connected in series.

[0069] In the series-connected battery string groups 10, the first battery string group 41 can have its positive electrode facing the upper end of the photovoltaic module 100 and its negative electrode facing the lower end of the photovoltaic module 100, and the second battery string group 42 can have its positive electrode facing the lower end of the photovoltaic module 100 and its negative electrode facing the upper end of the photovoltaic module 100. The negative electrode of the first battery string group 41 can be connected to the positive electrode of the second battery string group 42 to form a first series structure 51. In this case, the positive electrode of the first battery string group 41 and the negative electrode of the second battery string group 42 serve as electrode lead terminals, and no bypass diode is provided between the positive electrode of the first battery string group 41 and the negative electrode of the second battery string group 10.

[0070] Alternatively, the positive electrode of the second battery string group 42 may be directed toward the upper end of the photovoltaic module 100 and the negative electrode toward the lower end of the photovoltaic module 100, while the positive electrode of the first battery string group 41 may be directed toward the lower end of the photovoltaic module 100 and the negative electrode toward the upper end of the photovoltaic module 100. The negative electrode of the second battery string group 42 is connected to the positive electrode of the first battery string group 41 to form a first series structure 51. In this case, the positive electrode of the second battery string group 42 and the negative electrode of the first battery string group 41 serve as electrode lead terminals, and no bypass diode is provided between the positive electrode of the second battery string group 42 and the negative electrode of the first battery string group 41. The embodiment of the present application does not limit the order and method of connecting two adjacent battery strings 11 in series to meet various needs.

[0071] In this way, the positive and negative electrode lead-out terminals of the battery string group 10 can be located at the ends of the same side of the photovoltaic module 100, thereby realizing a high-efficiency battery module with a simple and reliable structure.

[0072] It should be noted that the end portion of the photovoltaic module 100 refers to the edge region of the photovoltaic module 100 located above or below the cell string 11. The end portion of the photovoltaic module 100 on the same side may be the end portion of the upper side of the photovoltaic module 100 or the end portion of the lower side of the photovoltaic module 100. In this way, the electrode lead-out terminals of the first cell string group 41 and the second cell string group 42 can both be located at the upper end portion of the photovoltaic module 100. Of course, the electrode lead-out terminals can also be located at the lower end portion of the photovoltaic module 100. The specific location of the electrode lead-out terminals is not limited in the embodiments of the present application to meet various needs.

[0073] At the same time, a leakage composite contact structure 30 is provided between the first doping layer 21 and the second doping layer 22 of the cell 12 to replace the traditional bypass diode as the leakage point, thereby reducing the leakage current of the cell 12, thereby controlling the heating power of the leakage point, reducing or even eliminating the influence of hot spots, and improving the power generation efficiency and safety of the photovoltaic module 100.

[0074] The embodiment of the present application does not specifically limit the number of battery cells 12 that each battery string 11 can include. For example, each battery string 11 can include 9 battery cells 12, 10 battery cells 12, 11 battery cells 12, etc. to meet various needs.

[0075] Example 5

[0076] See also Figure 6 and Figure 7 In some optional embodiments, when N is equal to 2 and each battery string group 10 includes two battery strings 11, the first battery string group 41 and the second battery string group 42 connected in series form a second series structure 52, and the third battery string group 43 and the fourth battery string group 44 connected in series form a third series structure 53;

[0077] No diodes are provided at both ends of the second series structure 52 and the third series structure 53;

[0078] The electrode lead-out end of the first battery string group 41 and the electrode lead-out end of the fourth battery string group 44 are located at the same end portion of the photovoltaic module 100 .

[0079] In this way, several cell strings 11 are connected in series to form a cell string group 10, several cell string groups 10 are connected in series to form a series structure, and several series structures are connected in series to form a photovoltaic module 100. Furthermore, the elimination of diodes can reduce module costs, reduce the area of ​​module obstruction, and improve the photoelectric conversion efficiency of the photovoltaic module 100. Furthermore, the need for a junction box is eliminated, improving the aesthetics and facilitating the installation and maintenance of the photovoltaic module 100.

[0080] Specifically, taking the example that each battery string group 10 includes two battery strings 11, the photovoltaic module 100 includes 2N battery string groups 10 connected in series, where N is a positive integer. When N is equal to 2, the photovoltaic module 100 includes four battery string groups 10 connected in series, that is, the photovoltaic module 100 includes the first battery string group 41, the second battery string group 42, the third battery string group 43 and the fourth battery string group 44 connected in series.

[0081] In the series-connected battery string groups 10 , the first battery string group 41 can be connected in series with the second battery string group 42 to form a second series structure 52 . The third battery string group 43 can be connected in series with the fourth battery string group 44 to form a third series structure 53 .

[0082] Because the number of cell strings 10 is always an even number, the electrode lead terminals of the two cell strings 10 at the head and tail of the photovoltaic module 100, that is, the electrode lead terminals of the first and fourth cell strings 10, can be located at the ends of the same side of the photovoltaic module 100, thereby achieving a high-efficiency battery module with a simple and reliable structure. In this way, the electrode lead terminals of the first and fourth cell strings 41, 44 can both be located at the upper end of the photovoltaic module 100. Furthermore, no bypass diodes are provided on either side of the electrode lead terminals, between the first and second cell strings 10, or between the third and fourth cell strings 10.

[0083] It should be noted that the first and third cell string groups 10 can both be arranged with their positive electrodes facing the upper end of the photovoltaic module 100 and their negative electrodes facing the lower end of the photovoltaic module 100, while the second and fourth cell string groups 10 can both be arranged with their negative electrodes facing the upper end of the photovoltaic module 100 and their positive electrodes facing the lower end of the photovoltaic module 100. Hereinafter, the "upper end of the photovoltaic module 100" is collectively referred to as the "upper end," and the "lower end of the photovoltaic module 100" is collectively referred to as the "lower end." In this way, the lower electrodes of the first and second cell string groups 10 can be connected in series, the upper electrodes of the second and third cell string groups 10 can be connected in series, and the lower electrodes of the third and fourth cell string groups 10 can be connected in series, so that the four cell string groups 10 are connected in series, that is, the second series structure 52 and the third series structure 53 are connected in series. In this case, the upper electrodes of the first and fourth battery string groups 10 can serve as electrode lead terminals. Of course, all battery string groups 10 can also be reversed, with the electrode lead terminals located at the bottom. The specific locations of the electrode lead terminals are not limited in this embodiment to accommodate a variety of needs.

[0084] At the same time, a leakage composite contact structure 30 is provided between the first doping layer 21 and the second doping layer 22 of the battery cell 12 to replace the bypass diode between the nth and n+1th battery string groups 10 as a leakage point, thereby reducing the leakage current of the battery cell 12, thereby controlling the heating power of the leakage point, reducing or even eliminating the influence of hot spots, and improving the power generation efficiency and safety of the photovoltaic module 100.

[0085] The embodiment of the present application does not specifically limit the number of battery cells 12 that each battery string 11 can include. For example, each battery string 11 can include 9 battery cells 12 (e.g. Figure 4 and Figure 6 ), 10 battery cells 12, 11 battery cells 12, etc., to meet various needs.

[0086] Example 6

[0087] See also Figure 1 , Figure 5 and Figure 7 In some optional embodiments, the photovoltaic module 100 further includes: a bus bar 60, the bus bar 60 being located at an end of the photovoltaic module 100 in a first direction and being laid along a second direction, the first direction being an arrangement direction of the plurality of cells 12 included in the cell string 11, and the second direction being perpendicular to the first direction;

[0088] No bus bar 60 is provided at the center line of the photovoltaic assembly 100 in the first direction.

[0089] In this way, there is no need to set the bus bar 60 at the center line position of the photovoltaic module 100, which reduces the use of the bus bar 60 in the middle of the module and reduces the cost of the module.

[0090] Specifically, the ends of the photovoltaic assembly 100 in the first direction are the upper end and the lower end in the above embodiment.

[0091] On the photovoltaic module 100 , several battery strings 11 arranged at intervals along the second direction are connected in parallel via busbars 60 to form a battery string group 10 . At the same time, several battery string groups 10 arranged at intervals along the second direction are connected in series via busbars 60 to form the photovoltaic module 100 .

[0092] For example, N is equal to 2. The upper electrodes of the plurality of battery strings 11 constituting the first battery string group 41 are connected via a first short bus bar, and the first short bus bar is only connected to the upper electrodes of the plurality of battery strings 11 of the first battery string group 41, while the lower electrodes are connected via a first long bus bar; at the same time, the first long bus bar connected to the lower end of the first battery string group 41 continues to extend along the second direction to connect to the lower electrodes of the second battery string group 42, while the upper electrodes of the second battery string group 42 are connected via a second long bus bar; at the same time, the second battery string group 42 The second long busbar at the upper end continues to extend along the second direction, extending to connect with several electrodes at the upper end of the third cell string group 43, while several electrodes at the lower end of the third cell string group 43 are connected via the third long busbar. Simultaneously, the third long busbar at the lower end of the third cell string group 43 continues to extend along the second direction, extending to connect with several electrodes at the lower end of the fourth cell string group 44, while several electrodes at the upper end of the fourth cell string group 44 are connected via the second short busbar, with the second short busbar only connecting several electrodes at the upper end of the fourth cell string group 44. This allows the cell strings 11 to be connected in parallel to form cell string groups 10, and the cell string groups 10 to be connected in series to form the photovoltaic module 100. In this way, the busbars 60 are laid transversely along the second direction at the upper and lower ends of the photovoltaic module 100, eliminating the need to provide busbars 60 at the centerline of the photovoltaic module 100, reducing the use of busbars 60 in the middle of the module and lowering the module cost.

[0093] It should be noted that the short bus bar refers to a bus bar 60 that is shorter than the long bus bar, that is, the length of the short bus bar is less than the length of the long bus bar. In actual implementation, the lengths of the short bus bar and the long bus bar can be specifically set according to the specifications of the battery string 11 and the component specifications. The above-mentioned bus bars 60 can be set on the light-receiving surface of the photovoltaic module 100 at the same time, and can also be set on the backlight surface of the photovoltaic module 100 at the same time. It is also possible to set some bus bars 60 on the backlight surface and some bus bars 60 on the light-receiving surface according to actual needs. No specific limitation is made here.

[0094] Example 7

[0095] See also Figure 1 , Figure 5 and Figure 7 In some optional embodiments, the bus bar 60 includes: a first bus bar 61 and a second bus bar 62; the first bus bar 61 is located on the backlight side of the photovoltaic component 100 and is arranged at the end close to the upper side of the photovoltaic component 100 in the first direction, and the second bus bar 62 is located on the backlight side of the photovoltaic component 100 and is arranged at the end close to the lower side of the photovoltaic component 100 in the first direction.

[0096] In this way, the first bus bar 61 and the second bus bar 62 are hidden on the backlight side of the photovoltaic module 100 and cannot be observed from the light-receiving side, thereby increasing the light-receiving area of ​​the photovoltaic module 100 and improving power generation efficiency.

[0097] Specifically, taking the above embodiment as an example, the first busbar 61 includes the first short busbar, the second long busbar, and the second short busbar at the upper end; the second busbar 62 includes the first long busbar and the second long busbar at the lower end. The first and second busbars 61 and 62 are arranged in a second direction perpendicular to the first direction.

[0098] In some embodiments, the busbar 60 can be produced as a single piece and then later divided into several busbars 60, which are then welded to the electrodes of the battery string 11. Alternatively, the busbar 60 produced as a single piece can be welded to the electrodes first, and then the welded busbar 60 can be cut as needed. The embodiments of this application do not limit the specific production method of the busbar 60 to meet various needs.

[0099] In the prior art, the exposed busbars 60 affect the aesthetics of the cell 12 and reduce the light-receiving area of ​​the cell 12, resulting in poor power generation efficiency. In the embodiment of the present invention, the first and second busbars 61, 62 are concealed on the backlight side of the photovoltaic module 100. They are not visible from the light-receiving side, increasing the light-receiving area of ​​the photovoltaic module 100 and improving power generation efficiency.

[0100] Example 8

[0101] See also Figure 7 In some optional embodiments, the photovoltaic module 100 further includes: an insulating strip, the insulating strip being arranged on the backlight surface of the photovoltaic module 100 and being laid along the second direction;

[0102] The first bus bar 61 is arranged along the second direction on a side of the insulating strip away from the battery string group 10 , and the first bus bar 61 covers the insulating strip;

[0103] The insulating strip is provided with a through hole or a notch, and the welding ribbon is connected to the first bus bar 61 through the through hole or the notch. The welding ribbon is arranged on the backlight surface of the photovoltaic module 100 and laid along the first direction. The welding ribbon is used to connect the grid lines on the battery string 11.

[0104] In this way, the welding ribbon is connected to the first bus bar 61 through the through hole or notch on the insulating strip, which not only ensures a reliable connection between the welding ribbon and the bus bar 60, but also avoids direct contact between the welding ribbon and other parts of the photovoltaic module 100, thereby achieving the dual effects of insulation and fixation.

[0105] Specifically, the insulating strip can be a long strip similar in shape to the first bus bar 61 , and the insulating strip is laid on the upper end of the battery string group 10 along the second direction. The first bus bar 61 is arranged on the side of the insulating strip away from the battery string group 10 along the second direction.

[0106] That is, on the backlight side of the photovoltaic module 100, the first bus bar 61 and the insulating strip are both arranged along the second direction, and the first bus bar 61 covers the insulating strip. When viewed from the backlight side of the photovoltaic module 100, the orthographic projection of the first bus bar 61 is completely within the orthographic projection of the insulating strip.

[0107] In some embodiments, the welding ribbons of the same polarity on the battery string 11 are connected to the corresponding electrodes on the battery string 11, for example, the positive welding ribbon is connected to the positive electrode of the battery string 11, and the negative welding ribbon is connected to the negative electrode of the battery string 11. Of course, the welding ribbons can also be directly set as the electrodes of the battery string 11, for example, the positive welding ribbon is directly used as the positive electrode of the battery string 11, and the negative welding ribbon is directly used as the negative electrode of the battery string 11, so that the welding ribbons of corresponding polarity on the battery string group 10 are connected to the corresponding bus bar 60 through the precise through holes or notches provided on the insulating strip.

[0108] For example, the first bus bar 61 can be connected to the relevant electrode at the upper end of the battery string group 10 (that is, one end of the corresponding polarity welding strip laid along the first direction) through the through hole or notch on the insulating strip, while avoiding contact between the irrelevant welding strip and the first bus bar 61. Of course, an insulating strip can also be provided at the lower end of the battery string group 10, and the second bus bar 62 can be connected to the relevant electrode at the lower end of the battery string group 10 (that is, one end of the corresponding polarity welding strip laid along the first direction) through the through hole or notch on the insulating strip, while avoiding contact between the irrelevant welding strip and the second bus bar 62. The embodiment of the present application does not limit the number of insulating strips and the specific laying positions to meet various needs.

[0109] Compared with the insulating components that need to be prepared by grooving, segment distribution, punching, etc., the insulating strip process of the embodiment of the present invention is simpler and can save production time.

[0110] In the embodiment of the present invention, the first bus bar 61 and the insulating bar are both arranged on the backlight surface of the photovoltaic module 100, which can avoid affecting the light-receiving surface of the photovoltaic module 100, thereby increasing the light-receiving area and the power generation efficiency.

[0111] Embodiment 9

[0112] See also Figure 1 In some optional embodiments, the ratio of the total area of ​​the 2N battery strings 10 to the total area of ​​the photovoltaic assembly 100 is 0.93-0.99. For example, the ratio of the total area of ​​the 2N battery strings 10 to the total area of ​​the photovoltaic assembly 100 may be 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc.

[0113] In this way, the space utilization rate is higher, the full screen rate is improved, which is beneficial to reducing the cost of the photovoltaic module 100 and improving the photoelectric conversion efficiency of the photovoltaic module 100.

[0114] Specifically, the 2N battery string groups 10 cover a larger area of ​​the photovoltaic module 100, have a higher space utilization rate, and improve the full screen rate, which is beneficial to reducing the cost of the photovoltaic module 100 and improving the photoelectric conversion efficiency of the photovoltaic module 100.

[0115] For example, when the performance requirements for the photovoltaic module 100 are high, the ratio of the total area of ​​the 2N battery string groups 10 to the total area of ​​the photovoltaic module 100 can be large, such as a ratio of 0.98; when the performance requirements for the photovoltaic module 100 are low, the ratio of the total area of ​​the 2N battery string groups 10 to the total area of ​​the photovoltaic module 100 can be small, such as a ratio of 0.94.

[0116] Furthermore, the cell 12 in the cell string 11 can be any one of a PERC (Passivated Emitter and RearCell) cell, a TOPCon (Tunnel Oxide Passivating Contact) cell, a BC (Back Contact) cell, a heterojunction cell, a perovskite cell or a stacked cell, without limitation.

[0117] The distance between adjacent cells 12 in the battery string 11 is -4 to 2.5 mm, that is, the cell spacing can be designed to be positive or negative when the cells 12 are connected. Optionally, the cell 12 is a whole battery or a cell 12 that has been cut into multiple equal parts, without limitation. When the cell spacing of the cell 12 is positive, the cells 12 can be connected in series by ordinary string welding. When the cell spacing of the cell 12 is negative, the cells 12 in the battery string 11 can be connected in series by shingling or stack welding.

[0118] For example, when the inter-cell spacing is positive, it indicates that two adjacent cells 12 are spaced a predetermined distance apart. This predetermined distance can be 0.2 mm, 0.3 mm, 0.5 mm, 0.6 mm, 0.8 mm, or 2 mm, etc., without limitation. Through the above arrangement, the photoelectric conversion efficiency is guaranteed, thereby ensuring the power generation efficiency of the module.

[0119] When the cell spacing is negative, it means that two adjacent battery cells 12 at least partially overlap, and the width of the overlapping portion of the distance between adjacent battery cells 12 is extremely large. For example, when the distance between adjacent battery cells 12 is -4 mm, it means that the width of the overlapping portion of adjacent battery cells 12 is 4 mm. Optionally, the width of the overlapping portion of adjacent battery cells 12 can be 0.2 mm, 1 mm, 2 mm / 3 mm or 3.5 mm, etc., without limitation.

[0120] When welding cells 12 to form a battery string 11, a stringer can be used to perform shingling or stacking connections. The series connection process may or may not be conductive, depending on the component manufacturing process. For example, when using the string welding process, the cells 12 achieve the circuit conductivity of the battery string 11 through the welding ribbon. However, when using the lamination welding process, the cells 12 and the welding ribbon are first arranged and placed. During this process, the circuit is not yet conductive. The circuit is not conductive until the lamination is completed, achieving partial overlap between cells, eliminating gaps between cells 12, significantly improving the component packaging density, making the layout more compact, and reducing component space waste.

[0121] Example 10

[0122] See also Figure 1 and Figure 8The photovoltaic system 200 provided in the embodiment of the present application includes the photovoltaic module 100 of any of the above embodiments, the electrode lead-out end of the first battery string group 10 in the photovoltaic module 100 is connected to the positive terminal of the photovoltaic module 100, and the electrode lead-out end of the last battery string group 10 in the photovoltaic module 100 is connected to the negative terminal of the photovoltaic module 100.

[0123] In the photovoltaic module 100 and the photovoltaic system 200 of the embodiment of the present application, the photovoltaic module 100 includes: 2N battery string groups 10 connected in series, N is a positive integer; each battery string group 10 includes m battery strings 11 connected in parallel, each battery string group 10 includes the same number of battery strings 11, and m is an integer greater than or equal to 2; each battery string 11 includes a plurality of battery cells 12 connected in series; the nth battery string group 10 and the n+1th battery string group 10 connected in series form a series structure, no diodes are provided at both ends of the series structure, and n is an odd number; the battery cell 12 includes a first doping layer 21 and a second doping layer 22, and the second doping layer 22 has an opposite polarity to the first doping layer 21; the battery cell 12 also includes a leakage composite contact structure 30, and the leakage composite contact structure 30 is at least partially provided between the first doping layer 21 and the second doping layer 22. In this way, since the number of battery string groups 10 is always an even number, it is possible to ensure that the electrode lead-out terminal of the first battery string group 41 and the electrode lead-out terminal of the last battery string group 10 are both located at the same side end of the photovoltaic module 100, which can realize a high-efficiency battery module with a simple and reliable structure. The leakage composite contact structure 30 forms a heat dissipation point inside the battery cell 12, reducing or even eliminating the impact of hot spots, thereby improving the power generation efficiency and safety of the photovoltaic module 100. At the same time, diodes are no longer provided, and busbars 60 are no longer provided at the center line position of the photovoltaic module 100, which can reduce the cost of the module, reduce the area of ​​the module being blocked, improve the photoelectric conversion efficiency of the photovoltaic module 100, and avoid the problems of hidden cracks and damage caused by the series connection of the busbars 60. There is no need to provide diodes, and thus there is no need to provide a junction box, which improves the aesthetics and facilitates the installation and maintenance of the photovoltaic module 100.

[0124] It should be noted that the electrode lead-out terminals of the first and last battery string groups 10 are led out from the same end of the photovoltaic module 100, and are respectively connected to the positive terminal and the negative terminal of the photovoltaic module 100. Ensuring that the electrode lead-out terminals of the photovoltaic module 100 and the positive and negative terminals of the photovoltaic system 200 are located on the same end reduces the cost of the photovoltaic modules 100 of the photovoltaic system 200 and improves the photoelectric conversion efficiency of the photovoltaic system 200.

[0125] In this embodiment, the photovoltaic system 200 can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of the photovoltaic system 200 are not limited to this, that is, the photovoltaic system 200 can be applied to all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system 200 may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can 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 junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to be converted into the alternating current required by the mains power grid and then connected to the mains power network to achieve solar power supply.

[0126] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative use of the above terms does 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 any one or more embodiments or examples.

[0127] In addition, the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A photovoltaic module, characterized in that: include: 2N battery string groups connected in series, where N is a positive integer; each battery string group includes m battery strings connected in parallel, each battery string group includes the same number of battery strings, and m is an integer greater than or equal to 2; each battery string includes a plurality of battery cells connected in series; The nth battery string group and the n+1th battery string group connected in series form a series structure, no diodes are provided at both ends of the series structure, and n is an odd number; The cell comprises a first doping layer and a second doping layer, wherein the second doping layer has a polarity opposite to that of the first doping layer; The battery cell further includes a leakage composite contact structure, which is at least partially disposed between the first doping layer and the second doping layer.

2. The photovoltaic module according to claim 1, characterized in that The conductivity type of the leakage composite contact structure is opposite to that of the first doping layer, and the leakage composite contact structure is of the same conductivity type as the second doping layer and is continuous as a whole.

3. The photovoltaic module according to claim 1, characterized in that The conductivity type of the leakage composite contact structure is opposite to that of the second doping layer, and the leakage composite contact structure has the same conductivity type as the first doping layer and is continuous as a whole.

4. The photovoltaic module according to claim 1, characterized in that When N is equal to 1 and each battery string group includes two battery strings, the first battery string group and the second battery string group connected in series form a first series structure; No diodes are provided at both ends of the first series structure; The electrode lead-out end of the first battery string group and the electrode lead-out end of the second battery string group are located at the same side end of the photovoltaic module.

5. The photovoltaic module according to claim 1, characterized in that When N is equal to 2 and each battery string group includes two battery strings, the first battery string group and the second battery string group connected in series form a second series structure, and the third battery string group and the fourth battery string group connected in series form a third series structure; No diodes are provided at both ends of the second series structure and at both ends of the third series structure; The electrode lead-out end of the first battery string group and the electrode lead-out end of the fourth battery string group are located at the same side end of the photovoltaic module.

6. The photovoltaic module according to claim 1, characterized in that The photovoltaic assembly further includes: a bus bar, the bus bar being located at an end of the photovoltaic assembly in a first direction and being laid along a second direction, the first direction being an arrangement direction of a plurality of battery cells included in the battery string, the second direction being perpendicular to the first direction; The bus bar is not provided at the center line of the photovoltaic assembly in the first direction.

7. The photovoltaic module according to claim 6, characterized in that: The bus bar includes: a first bus bar and a second bus bar; the first bus bar is located on the backlight side of the photovoltaic component and is arranged at the end close to the upper side of the photovoltaic component in the first direction, and the second bus bar is located on the backlight side of the photovoltaic component and is arranged at the end close to the lower side of the photovoltaic component in the first direction.

8. The photovoltaic module according to claim 7, characterized in that: The photovoltaic module further comprises: an insulating strip, the insulating strip being arranged on the backlight surface of the photovoltaic module and laid along the second direction; The first bus bar is arranged along the second direction on a side of the insulating bar away from the battery string group, and the first bus bar covers the insulating bar; The insulating strip is provided with a through hole or a notch, and the welding strip is connected to the first bus bar through the through hole or the notch. The welding strip is arranged on the backlight surface of the photovoltaic module and laid along the first direction. The welding strip is used to connect the grid lines on the battery string.

9. The photovoltaic module according to any one of claims 1 to 8, characterized in that: The ratio of the total area of ​​the 2N battery strings to the total area of ​​the photovoltaic module is 0.93-0.

99.

10. A photovoltaic system, characterized in that: Comprising a photovoltaic assembly according to any one of claims 1 to 9, wherein the electrode lead-out end of the first battery string group in the photovoltaic assembly is connected to the positive terminal of the photovoltaic assembly, and the electrode lead-out end of the last battery string group in the photovoltaic assembly is connected to the negative terminal of the photovoltaic assembly.

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