Photovoltaic module

Abstract

The embodiment of the application relates to the photovoltaic technical field, and discloses a photovoltaic module, the photovoltaic module comprises at least two cell strings arranged along a first direction, the cell string comprises a plurality of cell pieces, the back surface of the cell piece is provided with a solder strip, and the plurality of cell pieces are sequentially connected in series along the first direction through the solder strip; a head-tail bus bar is located at the back surface of a first edge cell piece of the cell string; the first edge cell piece is located at one side end of the cell string along the first direction and is not adjacent to other cell strings in a second direction; a first isolation strip is arranged between the head-tail bus bar and the first edge cell piece; a first conductive connecting part is used for electrically connecting a first solder strip of the first edge cell piece and the head-tail bus bar; the first conductive connecting part is extended from the first solder strip of the back surface of the first edge cell piece, and extends to the head-tail bus bar around the first isolation strip; the power generation conversion efficiency per unit area is improved.

Description

Technical Field

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

[0002] Back-contact (BC) cells are solar cells with no electrodes on the front and both positive and negative electrodes on the back. This design maximizes the use of incident light, reduces optical losses, and provides higher short-circuit current, thereby increasing the maximum output power of back-contact cell modules.

[0003] However, there are still large gaps between the cells inside the existing back-contact batteries, resulting in a low effective cell ratio in photovoltaic modules and a low power conversion efficiency per unit area. Utility Model Content

[0004] The purpose of this application is to provide a photovoltaic module that at least helps to increase the effective proportion of photovoltaic module cells and improve the power generation conversion efficiency per unit area.

[0005] To address the aforementioned technical problems, embodiments of this application provide a photovoltaic module, comprising: at least two cell strings arranged along a first direction, each cell string including multiple cells, each cell having a solder strip on its back side to connect the multiple cells sequentially in series along the first direction; a head and tail busbar located on the back side of a first edge cell of the cell string; the first edge cell located at one end of the cell string along the first direction and not adjacent to other cell strings in a second direction; the second direction being perpendicular to the first direction and parallel to the back side of the cell string; and a first isolation strip disposed between the head and tail busbar and the first edge cell. The first conductive connection portion is used to electrically connect the first solder strip of the first edge battery cell and the head and tail busbars; the first conductive connection portion extends from the first solder strip on the back of the first edge battery cell and extends around the first separator to the head and tail busbars; the first encapsulating film is used to cover the surface of the battery string away from the first separator; the second encapsulating film is used to cover the surface of the head and tail busbars away from the first separator; the first substrate is used to cover the surface of the first encapsulating film away from the battery string; the second substrate is used to cover the surface of the second encapsulating film away from the head and tail busbars.

[0006] In some embodiments, the first insulating strip includes: a first adhesive film layer, a first insulating layer, and a second adhesive film layer; the first insulating layer is located between the first adhesive film layer and the second adhesive film layer.

[0007] In some embodiments, the materials of the first adhesive film layer, the second adhesive film layer, the first encapsulating adhesive film, and the second encapsulating adhesive film are the same.

[0008] In some embodiments, the length of the first isolation strip in the first direction is greater than the length of the head and tail confluence strips in the first direction.

[0009] In some embodiments, the photovoltaic module further includes: at least two adjacent second isolation strips disposed on the back side of a second edge cell of a battery string; the second edge cell is located at one end of the battery string along the first direction and close to the adjacent battery string in the second direction; a third isolation strip is located on the side of the two adjacent second isolation strips away from the battery string; an intermediate busbar is located on the side of the third isolation strip away from the second isolation strip; a second conductive connection portion is used to electrically connect the second solder strip of the second edge cell and the intermediate busbar; the second conductive connection portion extends from the second solder strip on the back side of the second edge cell, first extends around the corresponding second isolation strip, and then bends around the third isolation strip to extend to the intermediate busbar.

[0010] In some embodiments, the thickness of the first isolation strip, the thickness of the second isolation strip, and the thickness of the third isolation strip are all the same.

[0011] In some embodiments, the second isolation strip includes: a third adhesive film layer, a second insulating layer, and a fourth adhesive film layer; the second insulating layer is located between the third adhesive film layer and the fourth adhesive film layer; the third isolation strip includes: a fifth adhesive film layer, a third insulating layer, and a sixth adhesive film layer; the third insulating layer is located between the fifth adhesive film layer and the sixth adhesive film layer.

[0012] In some embodiments, the materials of the third, fourth, fifth, and sixth adhesive film layers are the same as the materials of the first and second encapsulating films.

[0013] In some embodiments, the length of the third isolation strip in the first direction is greater than the length of the intermediate busbar in the first direction; the total length of two adjacent second isolation strips in the first direction is greater than the length of the third isolation strip in the first direction.

[0014] In some embodiments, the solder strips of the plurality of solar cells are connected in series using a negative-pitch serial welding method.

[0015] The technical solutions provided in this disclosure have at least the following advantages:

[0016] In this embodiment, the head and tail busbars of the photovoltaic module are hidden behind the first edge cells of the battery string, reducing the area occupied by the head and tail busbars on the front of the photovoltaic module and maximizing the area of ​​the cells to be laid, thereby increasing the effective proportion of the photovoltaic module cells and improving the power generation conversion efficiency per unit area. At the same time, the head and tail busbars are electrically isolated from the first edge cells by a first isolation strip to ensure the power generation efficiency and safety of the photovoltaic module. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 This is a front view of a photovoltaic module according to an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the back of a photovoltaic module according to an embodiment of this application;

[0020] Figure 3 This is a partial schematic diagram of the head and tail busbars of a photovoltaic module according to an embodiment of this application;

[0021] Figure 4 This is a partial schematic diagram of the intermediate busbar of a photovoltaic module according to an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of the structure of the first isolation strip of a photovoltaic module according to an embodiment of this application.

[0023] Figure Labels

[0024] Battery string (100), first edge battery cell (101), second edge battery cell (102), middle battery cell (103), head and tail busbars (201), middle busbar (202), first separator (301), first solder ribbon (1011), first conductive connection (1012), first adhesive film layer (3011), first insulating layer (3012), second adhesive film layer (3013), first encapsulation film (41), second encapsulation film (42), first substrate (50), second substrate (60), second separator (302), third separator (303), second solder ribbon (1021), second conductive connection (1022). Detailed Implementation

[0025] As can be seen from the background technology, there are still large gaps between the cells inside the existing back contact batteries, resulting in a low effective proportion of photovoltaic module cells and a low power generation conversion efficiency per unit area.

[0026] This disclosure provides a photovoltaic module in which the head and tail busbars are hidden behind the first edge cells of the battery string, reducing the area occupied by the head and tail busbars on the front of the photovoltaic module and maximizing the area of ​​the battery cells, thereby increasing the effective proportion of the photovoltaic module cells and improving the power generation conversion efficiency per unit area; at the same time, the head and tail busbars are electrically isolated from the first edge cells by a first isolation strip to ensure the power generation efficiency and safety of the photovoltaic module.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after are in an "or" relationship.

[0030] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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. Therefore, they should not be construed as limitations on the embodiments of this application. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may cover both above and below orientation depending on the context in which the term is used, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0032] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. Furthermore, when describing a component as "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0033] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. The formation or provision of a second component above or on a first component, or on the surface of a first component, or on one side of a first component, may include embodiments where the first and second components are in direct contact, and may also include embodiments where an additional component may be present between the first and second components, thereby preventing direct contact between the first and second components. For simplicity and clarity, various components may be drawn at different scales. In the drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, the formation or provision of a second component on the surface of a first component refers to direct contact between the first and second components. The term "component" may refer to a layer, film, region, portion, structure, etc.

[0034] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0035] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0036] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 1 This is a front view of a photovoltaic module provided according to an embodiment of the present disclosure. Figure 2 This is a schematic diagram of the back of a photovoltaic module provided in one embodiment of this disclosure. Figure 3 This is a partial schematic diagram of the head and tail busbars of a photovoltaic module provided in an embodiment of this disclosure. Figure 4 This is a partial schematic diagram of the intermediate busbar of a photovoltaic module provided in one embodiment of the present disclosure. The battery string 100 is arranged in a first direction, and a second direction is perpendicular to the first direction and parallel to the back surface of the battery string 100.

[0037] In some embodiments, a photovoltaic module includes: at least two cell strings 100 arranged along a first direction; each cell string 100 includes multiple cells, and each cell has a solder strip on its back side to connect the multiple cells sequentially in series along the first direction. The cells are typically sheet-like structures, having a front (or light-absorbing) side and a back side opposite each other in the thickness direction. The front side of the cell can absorb light energy and convert it into electrical energy. A photovoltaic module typically includes multiple cell strings 100 arranged in a matrix, i.e., some cell strings 100 are arranged along the first direction, and some are arranged along a second direction; the cell strings 100 located at the edge of the cell string matrix have a first edge cell 101, which is located at one end of the cell string 100 along the first direction and is not adjacent to other cell strings 100 in the second direction, which is perpendicular to the first direction and parallel to the back side of the cell string 100; the first edge cell 101... 101 is used for electrical connection with the head and tail busbars 201; the battery string 100 also has a second edge battery piece 102, which is located at one end of the battery string 100 along the first direction and close to the adjacent battery string 100. The second edge battery piece 102 is used for electrical connection with the middle busbar 202, so that multiple battery strings 100 are connected in series through the head and tail busbars 201 and the middle busbar 202. In the battery string 100, the battery pieces other than the first edge battery piece 101 and the second edge battery piece 102 are all middle battery pieces 103.

[0038] refer to Figure 2 The photovoltaic module includes head and tail busbars 201 and middle busbars 202. The head and tail busbars 201 are mainly used to lead the current of the cell string 100 to the external circuit of the module, playing the role of current collection and output. They are usually connected at both ends of the cell string 100 matrix and are mainly responsible for summing the current of the cell string 100 matrix and transmitting it to the junction box. The middle busbar 202 is located in the middle area of ​​the cell string 100 matrix and is used to connect multiple cell strings 100 in the cell string 100 matrix, playing the role of current splitting and summing. The head and tail busbars 201 and the middle busbar 202 cooperate with each other to ensure the efficient operation and stability of the photovoltaic module.

[0039] In some embodiments, the solder ribbons of multiple cells in the battery string 100 are connected in series in a negative-pitch manner. The types of cells included in the battery string 100 may be PERC (Passivated Emitter and Rear Cell), Topcon (Tunnel Oxide Passivated Contact), HJT (Heterojunction with Intrinsic Thin film), or IBC (Interdigitated Back Contact).

[0040] The head and tail busbars 201 are located on the back of the first edge battery cell 101; the first edge battery cell 101 is located at one end of the battery string 100 along the first direction and is not adjacent to other battery strings 100. The head and tail busbars 201 can connect the first edge battery cells 101 of two adjacent battery strings 100 along the second direction.

[0041] refer to Figure 3 The photovoltaic module also includes: a first isolation strip 301; the first isolation strip 301 is disposed between the head and tail busbars 201 and the first edge cell 101.

[0042] Specifically, a first isolation strip 301 is disposed on the back of the first edge solar cell 101, covering the first solder strip 1011 of the first edge solar cell 101. The head and tail busbars 201 are disposed on the side of the first isolation strip 301 away from the first edge solar cell 101. The first isolation strip 301 effectively isolates the electrical connection between the head and tail busbars 201 and the solar cell, improving the electrical insulation performance of the photovoltaic module, preventing current leakage or leakage, and avoiding short circuits caused by poor contact or accidental contact, thereby ensuring the safe operation of the photovoltaic module. Simultaneously, the first isolation strip 301 prevents physical damage to the solar cell caused by the head and tail busbars 201 during welding or installation. Furthermore, the first isolation strip 301 effectively blocks the corrosion of the solar cell by moisture, oxygen, etc., ensuring the long-term stability of the module in complex environments such as high temperature, high humidity, and strong ultraviolet radiation.

[0043] The thickness of the first insulating strip 301 can be set according to the DC system voltage level of the photovoltaic module. For 1500V photovoltaic modules, the thickness of the first insulating strip 301 needs to be greater than or equal to 0.3mm, such as 0.3mm, 0.35mm, 0.45mm, 0.45mm, 0.5mm, 0.55mm, etc. For 2000V photovoltaic modules, the thickness of the first insulating strip 301 needs to be greater than or equal to 0.45mm, such as 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, etc. By setting a thicker first insulating strip 301, it can be ensured that the first insulating strip 301 has sufficient thickness at the connection between the head and tail busbars 201 and the solder strip, avoiding the problems of inconvenient operation and easy deformation when applying the first insulating strip 301 due to its thinness.

[0044] refer to Figure 5 This is a schematic diagram of the structure of the first isolation strip of a photovoltaic module provided in an embodiment of the present disclosure. The first isolation strip 301 includes: a first adhesive film layer 3011, a first insulating layer 3012, and a second adhesive film layer 3013; the first insulating layer 3012 is located between the first adhesive film layer 3011 and the second adhesive film layer 3013; the first adhesive film layer 3011 is disposed on the back side of the first edge cell 101, the first insulating layer 3012 is disposed on the surface of the first adhesive film layer 3011 away from the first edge cell 101, and the second adhesive film layer 3013 is disposed on the surface of the first insulating layer 3012 away from the first adhesive film layer 3011.

[0045] There are various ways to specifically set the first insulating layer 3012. For example, the first insulating layer 3012 can be insulating adhesive, insulating tape, or insulating film. The first insulating strip 301 has a first adhesive film layer 3011 and a second adhesive film layer 3013. On the one hand, it provides a buffer stress between the solder ribbon and the solar cell, reducing the problem of microcracks in the solar cell. On the other hand, during the preparation of the first encapsulation film 41 and the second encapsulation film 42, the first adhesive film layer 3011 and the second adhesive film layer 3013 can be bonded to the first encapsulation film 41 and the second encapsulation film 42, effectively blocking the corrosion of the solar cell by water vapor, oxygen, etc., and extending the life of the photovoltaic module. The first adhesive layer 3011 and the second adhesive layer 3013 can be made of polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), polyolefin thermoplastic elastomer (POE), or polyethylene glycol terephthalate (PET). (Reference) Figure 3The photovoltaic module also includes: a first conductive connection portion 1012; the first conductive connection portion 1012 is used to electrically connect the first solder strip 1011 of the first edge cell 101 and the head and tail busbars 201; the first conductive connection portion 1012 extends from the first solder strip 1011 on the back of the first edge cell 101 and extends around the first isolation strip 301 to the head and tail busbars 201.

[0046] refer to Figure 3 The specific implementation of the connection between the head and tail busbars 201 and the first edge battery cell 101 is as follows: after the first conductive connection part 1012 is led out from the solder strip of the first edge battery cell 101, it is directly flipped to the back side, that is, the first conductive connection part 1012 is connected to the first solder strip 1011 on the back side of the first edge battery cell 101. The first conductive connection part 1012 extends out from the first solder strip 101 on the back side of the first edge battery cell 101, first extending in a direction parallel to the first isolation strip 301 and away from the battery string 100, then bending upward and extending in a direction close to the head and tail busbars 201, and then bending again to connect the head and tail busbars 201.

[0047] Specifically, the length of the first isolation strip 301 in the first direction is greater than the length of the head and tail busbars 201 in the first direction, thereby effectively isolating the first edge battery cell 101 from the head and tail busbars 201 and improving the electrical isolation effect of the first isolation strip 301.

[0048] refer to Figure 3 , Figure 4 The photovoltaic module also includes: a first encapsulating film 41 and a second encapsulating film 42. The first encapsulating film 41 is used to cover the surface of the cell string 100 (including the first edge cell 101 and the second edge cell 102) away from the first separator 301. The second encapsulating film 42 is used to cover the surface of the head and tail busbars 201 away from the first separator 301.

[0049] The first encapsulating film 41 and the second encapsulating film 42 can firmly bond the glass cover (such as the first substrate 50 and the second substrate 60) to the solar cells, ensuring the structural stability of the photovoltaic module. Specifically, the materials of the first encapsulating film 41 and the second encapsulating film 42 can be any of the following: polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyolefin thermoplastic elastomer (POE) film, and polyethylene glycol terephthalate (PET) film.

[0050] In some embodiments, the materials of the first encapsulant layer 3011 and the second encapsulant layer 3013 are the same as the materials of the first encapsulant film 41 and the second encapsulant film 42. During the fabrication of the first encapsulant film 41 and the second encapsulant film 42, the first encapsulant film 41 and the second encapsulant film 42 are filled into the gaps of the photovoltaic module. The first encapsulant film 41 and the second encapsulant film 42 can adhere well to the first encapsulant film layer 3011 and the second encapsulant film layer 3013 of the first separator 301, more effectively blocking the corrosion of the solar cells by moisture, oxygen, etc., and further extending the life of the photovoltaic module. The first encapsulant film 41 and the second encapsulant film 42 can be fused together during the filling process of the photovoltaic module gaps. The illustration is only for illustrating the positional relationship between the first encapsulant film 41 and the second encapsulant film 42 and the solar cells. In reality, the first encapsulant film 41 and the second encapsulant film 42 can be filled as a whole into the photovoltaic module gap between the first substrate 50 and the second substrate 60.

[0051] refer to Figure 3 , Figure 4 The photovoltaic module also includes a first substrate 50, which covers the surface of the first encapsulating film 41 away from the cell string (including the first edge cell 101 and the second edge cell 102). The first substrate 50 is located on the outermost layer of the photovoltaic module, and its main function is to protect the cells from damage caused by external environments such as ultraviolet rays, wind, sand, and hail, while allowing sunlight to pass through efficiently to reach the cells. The first substrate 50 can be glass, such as tempered glass, which has high light transmittance, high strength, and good weather resistance, and can protect the cells from damage caused by external environments. At the same time, the glass cover has higher light transmittance, which can maximize the transmission of sunlight to the cells, thereby improving the power generation efficiency of the module. The glass cover also has good corrosion resistance and anti-aging properties, and can be used for a long time under various climatic conditions. In addition, an anti-reflective film, such as silicon dioxide or polydimethylsiloxane, can be deposited on the surface of the glass cover to further reduce light reflection, improve the light transmittance of the photovoltaic module, and improve the light conversion efficiency.

[0052] The first substrate 50 can also be a transparent polymer material, such as ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVF), polyvinylidene difluoride (PVDF), etc., to reduce the weight of the component.

[0053] The photovoltaic module also includes a second substrate 60, which covers the surface of the second encapsulating film 42 away from the head and tail busbars 201. The second substrate 60 is located on the back of the photovoltaic module and its main function is to provide electrical insulation, waterproofing, moisture protection, and mechanical protection, ensuring the long-term stability and safety of the module. The second substrate 60 can be a composite backsheet, for example, composed of fluorocarbon film, polyester film (Polyethylene Terephthalate, PET), and adhesives, possessing good weather resistance and mechanical properties; the second substrate 60 can also be a coated backsheet, for example, coated with a fluororesin coating on a PET base film, possessing excellent reflectivity, adhesion, abrasion resistance, and weather resistance; the second substrate 60 can also be a transparent backsheet, in some bifacial power generation modules, where a transparent backsheet allows some light to pass through, improving power generation efficiency.

[0054] refer to Figure 4 The photovoltaic module also includes at least two adjacent second isolation strips 302, which are disposed on the back side of the second edge cell 102 of a cell string 100; the second edge cell 102 is located at one end of the cell string 100 along the first direction and close to the adjacent cell string 100.

[0055] The photovoltaic module also includes a third isolation strip 303, which is located on the side of the two adjacent second isolation strips 302 away from the cell string 100.

[0056] The photovoltaic module also includes an intermediate busbar 202, which is located on the side of the third isolation bar 303 away from the second isolation bar 302.

[0057] Specifically, the second isolation strip 302 and the third isolation strip 303 are disposed between the intermediate busbar 202 and two adjacent second edge solar cells 102. Each of the two adjacent second edge solar cells 102 has a second isolation strip 302 covering the second solder strip 1021 of the second edge solar cell 102. The second isolation strip 302 is disposed on the back of the second edge solar cell 102, and the third isolation strip 303 overlaps with each of the two adjacent second isolation strips 302. By disposing of the second isolation strip 302 and the third isolation strip 303 between the intermediate busbar 202 and the second edge solar cells 102, the electrical connection between the intermediate busbar 202 and the second edge solar cells 102 can be more effectively isolated, further improving the electrical insulation performance of the photovoltaic module and ensuring the safe operation of the photovoltaic module.

[0058] The thickness of the second isolation strip 302 and the third isolation strip 303 can be set according to the DC system voltage level of the photovoltaic module. For 1500V photovoltaic modules, the thickness of the second isolation strip 302 and the third isolation strip 303 should be greater than or equal to 0.3mm, such as 0.3mm, 0.35mm, 0.45mm, 0.45mm, 0.5mm, 0.55mm, etc. For 2000V photovoltaic modules, the thickness of the second isolation strip 302 and the third isolation strip 303 should be greater than or equal to 0.45mm, such as 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, etc. By setting thicker second and third isolation strips 302 and 303, it can be ensured that the second and third isolation strips 302 and 303 have sufficient thickness at the connection between the intermediate busbar 202 and the welding strip. This avoids the problem that the second and third isolation strips 302 and 303 are too thin, making it inconvenient to apply and easy to deform when pulling.

[0059] In some embodiments, the thicknesses of the first isolation strip 301, the second isolation strip 302, and the third isolation strip 303 are all the same. When the first isolation strip 301, the second isolation strip 302, and the third isolation strip 303 are applied in photovoltaic modules of the same voltage level, by setting the first isolation strip 301, the second isolation strip 302, and the third isolation strip 303 to have the same structure and thickness, the problem of multiple isolation strips having different thicknesses, which would otherwise force the voltage level to be set according to the thinner isolation strip and result in a lower voltage level for the photovoltaic module, is avoided.

[0060] refer to Figure 4 The photovoltaic module also includes a second conductive connection portion 1022, which is used to electrically connect the second solder strip 1021 of the second edge cell 102 and the intermediate busbar 202. The second conductive connection portion 1022 extends from the second solder strip 1021 on the back of the second edge cell 102, and first extends around the corresponding second isolation strip 302, and then bends around the third isolation strip 303 to extend to the intermediate busbar 202.

[0061] refer to Figure 4The specific implementation of the intermediate busbar 202 connecting two adjacent second edge battery cells 102 is as follows: after the second solder strip 1021 of each second edge battery cell 102 leads out the second conductive connection portion 1022, it is directly flipped to the back side. That is, the second conductive connection portion 1022 is connected to the second solder strip 1021 of a second edge battery cell 102. The second conductive connection portion 1022 extends from the second solder strip 1021 of a second edge battery cell 102, first extending along the direction close to the adjacent battery string 100, then bending along the direction close to the third isolation strip 303, then bending along the direction away from the adjacent battery string 100 to the gap between the second isolation strip 302 and the third isolation strip 303, then bending along the direction close to the intermediate busbar 202, and then bending to one side end of the intermediate busbar 202. The second solder strips of the two second edge battery cells 102 are connected to the intermediate busbar 202 in the same way.

[0062] Specifically, the length of the third isolation strip 303 in the first direction is greater than the length of the middle busbar 202 in the first direction; the total length of the two adjacent second isolation strips 302 in the first direction is greater than the length of the third isolation strip 303 in the first direction, thereby effectively isolating the second edge cell 102 from the middle busbar 202 and improving the electrical isolation effect of the photovoltaic module.

[0063] In some embodiments, the second separator 301 includes: a third adhesive film layer, a second insulating layer, and a fourth adhesive film layer; the second insulating layer is located between the third adhesive film layer and the fourth adhesive film layer; the third adhesive film layer is disposed on the back side of the second edge battery cell, the second insulating layer is disposed on the surface of the third adhesive film layer away from the second edge battery cell, and the fourth adhesive film layer is disposed on the surface of the second insulating layer away from the third adhesive film layer; the third separator 303 includes: a fifth adhesive film layer, a third insulating layer, and a sixth adhesive film layer; the third insulating layer is located between the fifth adhesive film layer and the sixth adhesive film layer; the fifth adhesive film layer is disposed on the side of the second separator strip away from the second edge battery cell, the third insulating layer is disposed on the surface of the fifth adhesive film layer away from the second separator strip, and the sixth adhesive film layer is disposed on the surface of the third insulating layer away from the fifth adhesive film layer. It can be seen that the layer structure of the second separator 302 and the third separator 303 is the same as that of the first separator 301, and the layer structure of the second separator 302 and the third separator 303 can also be referenced. Figure 5 .

[0064] Specifically, the materials of the third, fourth, fifth, and sixth adhesive film layers can be any of the following: polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyolefin thermoplastic elastomer (POE) film, and polyethylene glycol terephthalate (PET) film.

[0065] There are various ways to specifically set the second and third insulating layers. For example, the second and third insulating layers can be insulating adhesive, insulating tape, or insulating film. The second separator 302 has a third and fourth adhesive film layer, and the third separator 303 has a fifth and sixth adhesive film layer. This serves two purposes: firstly, it provides a buffer stress between the solder ribbon and the solar cell, reducing the risk of microcracks in the solar cell; secondly, during the preparation of the first encapsulation film 41 and the second encapsulation film 42, the first adhesive film layer 3011 and the second adhesive film layer 3013 can bond with the first encapsulation film 41 and the second encapsulation film 42, effectively blocking the corrosion of the solar cell by moisture and oxygen, and extending the lifespan of the photovoltaic module.

[0066] In some embodiments, the materials of the third, fourth, fifth, and sixth encapsulating film layers are the same as the materials of the first encapsulating film 41 and the second encapsulating film 42. During the fabrication of the first and second encapsulating films 41 and 42, the first and second encapsulating films 41 and 42 are filled into the gaps of the photovoltaic module. The first and second encapsulating films 41 and 42 can adhere well to the third and fourth encapsulating film layers of the second separator 301 and the fifth and sixth encapsulating film layers of the third separator 303, more effectively blocking the corrosion of the solar cells by moisture, oxygen, etc., and further extending the life of the photovoltaic module.

[0067] In the aforementioned photovoltaic module, the head and tail busbars 201 are hidden behind the first edge cell 101 of the cell string 100, reducing the area occupied by the head and tail busbars 201 on the front of the photovoltaic module and maximizing the cell laying area, thereby increasing the effective proportion of the photovoltaic module cells and improving the power generation conversion efficiency per unit area. At the same time, the head and tail busbars 201 and the first edge cell 101 are electrically isolated from each other by the first isolation strip 301, ensuring the power generation efficiency and safety of the photovoltaic module.

[0068] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of this disclosure. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that, include: At least two battery strings arranged along a first direction, the battery strings comprising multiple battery cells, each battery cell having a solder strip on its back side to connect multiple battery cells sequentially in series along the first direction via the solder strip; The head and tail busbars are located on the back side of the first edge battery cell of the battery string; the first edge battery cell is located at one end of the battery string along the first direction and is not adjacent to other battery strings in the second direction; the second direction is perpendicular to the first direction and parallel to the back side of the battery string. A first isolation strip is disposed between the head and tail busbars and the first edge battery cell; A first conductive connection portion is used to electrically connect the first solder strip of the first edge battery cell and the head and tail busbars; the first conductive connection portion extends from the first solder strip on the back of the first edge battery cell and extends around the first isolation strip to the head and tail busbars; A first encapsulating film is used to cover the surface of the battery string away from the first separator strip; The second encapsulating film is used to cover the surface of the head and tail busbars away from the first isolation strip; A first substrate, the first substrate being used to cover the surface of the first encapsulating film away from the battery string; The second substrate is used to cover the surface of the second encapsulating film away from the head and tail busbars.

2. The photovoltaic module according to claim 1, characterized in that, The first isolation strip includes: a first adhesive film layer, a first insulating layer, and a second adhesive film layer; The first insulating layer is located between the first adhesive film layer and the second adhesive film layer.

3. The photovoltaic module according to claim 2, characterized in that, The materials of the first adhesive film layer, the second adhesive film layer, the first encapsulating adhesive film, and the second encapsulating adhesive film are the same.

4. The photovoltaic module according to claim 1, characterized in that, The length of the first isolation strip in the first direction is greater than the length of the head and tail busbars in the first direction.

5. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The photovoltaic module also includes: At least two adjacent second isolation strips are disposed on the back side of the second edge battery cell of the battery string; the second edge battery cell is located at one end of the battery string along the first direction and is close to the adjacent battery string in the second direction; A third isolation strip is located on the side of two adjacent second isolation strips away from the battery string; An intermediate busbar is located on the side of the third isolation strip away from the second isolation strip; The second conductive connection portion is used to electrically connect the second solder strip of the second edge battery cell and the intermediate busbar; the second conductive connection portion extends from the second solder strip on the back of the second edge battery cell, first extends around the corresponding second isolation strip, and then bends around the third isolation strip to extend to the intermediate busbar.

6. The photovoltaic module according to claim 5, characterized in that, The thickness of the first isolation strip, the thickness of the second isolation strip, and the thickness of the third isolation strip are all the same.

7. The photovoltaic module according to claim 5, characterized in that, The second isolation strip includes: a third adhesive film layer, a second insulating layer, and a fourth adhesive film layer; The second insulating layer is located between the third adhesive layer and the fourth adhesive layer; The third isolation strip includes: a fifth adhesive film layer, a third insulating layer, and a sixth adhesive film layer; The third insulating layer is located between the fifth adhesive layer and the sixth adhesive layer.

8. The photovoltaic module according to claim 7, characterized in that, The materials of the third, fourth, fifth, and sixth encapsulation layers are the same as those of the first and second encapsulation films.

9. The photovoltaic module according to claim 5, characterized in that, The length of the third isolation strip in the first direction is greater than the length of the intermediate busbar in the first direction; The total length of two adjacent second isolation strips in the first direction is greater than the length of the third isolation strip in the first direction.

10. The photovoltaic module according to any one of claims 1 to 3, characterized in that, The solder strips of multiple solar cells are connected in series using a negative-pitch serial welding method.

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