Photovoltaic module

Abstract

The invention relates to a photovoltaic module, the photovoltaic module comprises three battery string groups which are connected in series, each battery string group comprises four battery strings which are connected in parallel, each battery string comprises a plurality of fragmented battery pieces, and each fragmented battery piece is a quarter piece formed by cutting a whole battery piece; the three battery string groups which are connected in series are distributed along a first direction, and a plurality of fragmented battery pieces in the battery strings are distributed along a second direction; the heads and the tails of the battery strings are connected with the bus bars, the bus bars comprise first bus bars located at the two ends of the photovoltaic module in the second direction and second bus bars located in the middle of the photovoltaic module in the second direction, and the first bus bars are located on the back face of the photovoltaic module. According to the photovoltaic module, on one hand, one half of the fragmented battery piece in the battery string is replaced by one fourth of the fragmented battery piece, and on the other hand, the photoelectric conversion efficiency of the photovoltaic module is relatively high by enabling the first bus bar to be located on the back surface of the photovoltaic module.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic module. Background Art

[0002] Photovoltaic modules can directly convert solar radiation energy into electrical energy, mainly based on the photovoltaic effect of crystalline silicon. That is, when the photons of sunlight are absorbed by semiconductor crystalline silicon, electron-hole pairs are generated. When these electron-hole pairs reach the pn junction composed of p-type crystalline silicon and n-type crystalline silicon, they are separated to both sides of the pn junction by the junction electric field. When an external load is connected, photocurrent is formed and electrical energy is output.

[0003] The photoelectric conversion efficiency of existing photovoltaic modules is relatively low, and how to improve the photoelectric conversion efficiency of photovoltaic modules is an urgent problem to be solved. Summary of the Invention

[0004] The present application provides a photovoltaic module for improving the photoelectric conversion efficiency of the photovoltaic module.

[0005] A photovoltaic module provided in an embodiment of the present application includes three battery string groups connected in series, each of the battery string groups includes four battery strings connected in parallel, and the battery string includes a plurality of split battery cells, each of which is a quarter slice cut from a whole battery cell; The three battery strings connected in series are distributed along a first direction, and the plurality of battery cells in the battery string are distributed along a second direction; The head and tail of the battery string are both connected to bus bars, which include: a first bus bar located at both ends of the photovoltaic component along the second direction and a second bus bar located in the middle of the photovoltaic component along the second direction, and the first bus bar is located on the back of the photovoltaic component.

[0006] In a possible design, a first insulating member is provided between the first bus bar and the segmented battery cells.

[0007] In a possible design, the photovoltaic assembly further includes a jumper extending along the second direction, the jumper is connected to the first bus bar, and is located between adjacent battery strings; a second insulating member is provided between the jumper and the segmented battery cells.

[0008] In a possible design, the first insulating member and the second insulating member are integrally provided.

[0009] In one possible design, the jumper includes a first jumper not connected to the second bus bar and a second jumper connected to the second bus bar; the first jumper has a first lead-out end near the second bus bar, and the first lead-out end is provided with a first junction box; the second jumper has a second lead-out end near the second bus bar, and the second lead-out end is provided with a second junction box.

[0010] In one possible design, the quarter slices cut from the whole battery cell include two edge slices and two middle slices; the multiple sliced ​​battery cells in the battery string are all edge slices; or, the multiple sliced ​​battery cells in the battery string are all middle slices; or, the multiple sliced ​​battery cells in the battery string have both edge slices and middle slices.

[0011] In a possible design, when the plurality of segmented battery cells in the battery string include both edge cells and middle cells, the edge cells and the middle cells are arranged alternately.

[0012] In a possible design, the length L of the segmented battery cell satisfies: 180 mm ≤ L ≤ 220 mm, and the width W of the segmented battery cell satisfies: 45 mm ≤ W ≤ 55 mm.

[0013] In a possible design, the number n of the segmented battery cells included in each battery string satisfies: 18≤n≤24.

[0014] In a possible design, in the battery string, the distance d between adjacent battery cells satisfies: -0.5 mm ≤ d ≤ 1.0 mm.

[0015] In this application, by replacing the sliced ​​cells in the cell string from half a cell to a quarter cell and adopting a three-in-four string arrangement, the area of ​​the sliced ​​cells is reduced, the power loss in each cell string is reduced, and the overall output current of the photovoltaic module is reduced by using smaller sliced ​​cells, thereby improving the photovoltaic module's photoelectric conversion efficiency. At the same time, the first bus bar is located on the back of the photovoltaic module, that is, along the thickness direction of the sliced ​​cells. The projection of the first bus bar on the cell string mostly overlaps with the cell string, thereby reducing the area ratio of the bus bar in the photovoltaic module and increasing the area ratio of the cell string in the photovoltaic module, further improving the photovoltaic module's photoelectric conversion efficiency.

[0016] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of a photovoltaic module provided in this application in a specific embodiment; Figure 2 for Figure 1 Circuit diagram of photovoltaic modules; Figure 3 for Figure 1 A schematic structural diagram in which no jumper wire, first insulating member, and second insulating member are placed on the photovoltaic module and the first bus bar is not folded to the back of the photovoltaic module; Figure 4 for Figure 1 Schematic diagram of part of the structure of photovoltaic modules; Figure 5 for Figure 1 A top view of the first lead-out terminal; Figure 6 for Figure 1 A side view of the first lead-out terminal; Figure 7 for Figure 1 A top view of the second lead-out terminal; Figure 8 A schematic diagram of the structure of a whole battery cell being cut into four separate battery cells; Figure 9 This is a schematic structural diagram of another specific embodiment of the photovoltaic module provided by the present application; wherein the first bus bar has not yet been folded to the back side of the cell slice; Figure 10 for Figure 9 Schematic diagram of the structure in which the first bus bar of the photovoltaic module is folded over to the back of the sliced ​​solar cell.

[0018] Reference numerals: 11-battery string; 111-sliced ​​battery cell; 112-welding strip; 12- first bus bar; 13- second bus bar; 13a-second lead; 14-First jumper; 14a-first lead; 15-second jumper; 16- first insulating member; 17- second insulating member; 21-first bypass diode; 22- second bypass diode; 23-Third bypass diode.

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0020] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0021] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0022] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0023] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0024] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that an element is connected to another element "on" or "under", it can not only be directly connected to the other element "on" or "under", but also be indirectly connected to the other element "on" or "under" through an intermediate element.

[0025] At present, conventional photovoltaic modules are usually composed of six battery strings connected in series to form a battery string group, and then two battery string groups are connected in parallel to form six strings (that is, two parallel to six strings). The sliced ​​battery cells in the battery string are half of the whole battery cell cut. Therefore, the area of ​​the sliced ​​battery cells is relatively large, and each battery cell generates relatively more carriers. The current in each battery string is relatively large. Since the power loss of electrons during transmission is proportional to the square of the current, the loss of photovoltaic modules is relatively large.

[0026] At the same time, the head and tail of the battery string are connected to busbars to conduct the current in the battery string. Since the busbars are placed at the head and tail of the battery string, the battery cell area in the photovoltaic module is relatively small, affecting the photovoltaic module's photoelectric conversion efficiency.

[0027] The embodiment of the present application provides a photovoltaic module, such as Figure 1 and Figure 2 As shown, the photovoltaic module includes three battery strings connected in series ( Figure 1 The dotted box in the figure shows one of the battery string groups), each battery string group includes four parallel battery strings 11 ( Figure 2 The dashed box in the figure shows one of the battery strings 11. The battery string 11 includes multiple sliced ​​battery cells 111. Each sliced ​​battery cell 111 is a quarter slice cut from a whole battery cell. The multiple sliced ​​battery cells 111 in a battery string 11 are electrically connected via welding ribbons 112.

[0028] By replacing the segmented cell 111 in the cell string 11 from a half cell to a quarter cell and adopting a three-in-four string arrangement, the area of ​​the segmented cell 111 is reduced, the power loss in each cell string 11 is reduced, and the use of smaller segmented cell 111 leads to a reduction in the overall output current of the photovoltaic module, thereby improving the photoelectric conversion efficiency of the photovoltaic module.

[0029] Specifically, compared with conventional photovoltaic modules that use a two-in-parallel six-string arrangement, the photovoltaic module in this application has a current in a single cell string 11 that is 1 / 2 of the current in a single cell string in a conventional photovoltaic module, thereby reducing the power loss of a single cell string 11 by 3 / 4 and increasing the overall power of the photovoltaic module by at least 5W.

[0030] For ease of description, the direction of arrangement of the three battery strings in series is defined as a first direction X, the direction of arrangement of the multiple sliced ​​battery cells 111 in the battery string 11 is defined as a second direction Y, and the thickness direction of the sliced ​​battery cells 111 is defined as a third direction Z. One end of the battery string 11 along the second direction Y is the head of the battery string 11, and the other end is the tail of the battery string 11.

[0031] Furthermore, the head and tail of the battery string 11 are connected to the busbars via welding ribbons 112. The busbars include: a first busbar 12 located at both ends of the photovoltaic module along the second direction Y; and a second busbar 13 located in the middle of the photovoltaic module along the second direction Y. The first busbar 12 is located on the back of the photovoltaic module, and both the first busbar 12 and the second busbar 13 extend along the first direction X. The second busbar 13 being located in the middle of the photovoltaic module along the second direction Y means that the second busbar 13 can be located on the midline of the photovoltaic module along the second direction Y, or can be located to the left or right of the photovoltaic module along the second direction Y, that is, the second busbar 13 is not located at both ends of the photovoltaic module along the second direction Y. The first bus bar 12 is located on the back side of the photovoltaic module. That is, along the third direction Z, the projection of the first bus bar 12 on the cell string 11 mostly overlaps with the cell string 11. This reduces the area of ​​the bus bar in the photovoltaic module, increases the area of ​​the cell string 11 in the photovoltaic module, and further improves the photovoltaic conversion efficiency of the photovoltaic module. The back side of the photovoltaic module refers to the side facing away from the light.

[0032] Specifically, such as Figure 1 and Figure 2 As shown, the four battery strings 11 in the battery string group are arranged in an array along a first direction X and a second direction Y, i.e., the four battery strings 11 are arranged in two rows and two columns. For ease of description, the two ends of the battery strings 11 distributed along the second direction Y are defined as the tail end, the end facing the other battery strings 11, and the end not facing the other battery strings 11 as the head end. That is, the head end of the battery string 11 is connected to the first bus bar 12, and the tail end of the battery string 11 is connected to the second bus bar 13.

[0033] like Figure 3 As shown, two first bus bars 12 are provided at each end of the photovoltaic module along the second direction Y, wherein one first bus bar 12 is longer and the other first bus bar 12 is shorter. The longer first bus bar 12 is connected to the battery strings 11 in two battery string groups, while the shorter first bus bar 12 is connected to the battery strings 11 in only one battery string group.

[0034] Optionally, two shorter first bus bars 12 located at both ends of the photovoltaic assembly along the second direction Y are connected to the same battery string 11 .

[0035] Accordingly, three second bus bars 13 are provided, and each second bus bar 13 is connected to only one battery string 11 in one battery string group.

[0036] More specifically, the photovoltaic module also includes jumpers extending along the second direction Y. These jumpers connect to the busbars and are located between adjacent battery strings. These jumpers include a first jumper 14 and a second jumper 15. The first jumper 14 connects to the two longer first busbars 12 and is not connected to the second busbar 13. The second jumper 15 connects to the two shorter first busbars 12 and is also connected to the middle second busbar 13 along the first direction X. The blue lines in the accompanying drawings represent the jumpers.

[0037] Preferably, along the first direction X, the shorter first bus bar 12 protrudes from the edge of the battery string group connected thereto, so as to facilitate the connection between the shorter first bus bar 12 and the second jumper 15 .

[0038] Further, such as Figure 4 As shown, a first insulating member 16 is provided between the first bus bar 12 and the segmented battery cell 111 . The width of the first insulating member 16 is greater than that of the first bus bar 12 to prevent the first bus bar 12 from contacting the segmented battery cell 111 .

[0039] A jumper wire is typically a conductive metal strip. To prevent short circuits caused by contact between the jumper wire and the cell 111, a second insulating member 17 is provided between the jumper wire and the cell 111. The width L1 of the second insulating member 17 is greater than the width L2 of the jumper wire, effectively preventing contact between the jumper wire and the cell 111, thereby improving the safety and reliability of the photovoltaic module. The red lines in the accompanying drawings illustrate the first insulating member 16 and the second insulating member 17.

[0040] Specifically, the width L2 of the jumper is 4 mm to 8 mm, and the thickness is 0.15 mm to 0.4 mm. If the width of the jumper is less than 4 mm and the thickness is less than 0.15 mm, the cross-sectional area of ​​the jumper is small, resulting in poor current carrying capacity and inability to carry the current in the photovoltaic module. If the width L2 of the jumper is greater than 8 mm, the size of the area where the jumper overlaps with the cell 111 increases, increasing the risk of the jumper causing hidden cracks in the cell 111 during the lamination process. If the photovoltaic module is a double-glass module, both sides of the cell 111 are used to absorb sunlight. If the width of the jumper is too large, it will increase the obstruction of the cell 111, thereby affecting the photovoltaic module's photoelectric conversion efficiency. Therefore, the width L2 of the jumper can be 4 mm, 6 mm, 8 mm, etc. Along the first direction X, the spacing between adjacent cell 111 is 1.6 mm, which is less than the width L2 of the jumper. Therefore, the jumper can be set on one side of the cell 111 in the thickness direction. If the thickness of the jumper is greater than 0.4 mm, the jumper will protrude from the battery cell 111 to a larger extent. During the lamination process, the jumper may squeeze the battery cell 111, causing hidden cracks in the battery cell 111. It may also increase the possibility of deformation of the jumper, causing the jumper to contact the battery cell 111 and cause a short circuit. Therefore, the thickness of the jumper can be 0.15 mm, 0.3 mm, 0.4 mm, etc.

[0041] Preferably, the difference between the width L1 of the second insulating member 17 and the width L2 of the jumper wire satisfies: 6mm≤L1-L2≤10mm. For example, the difference L1-L2 can be: 6mm, 6.5mm, 7mm, 8mm, 9mm, 9.5mm, 10mm, etc.

[0042] The difference L1-L2 should be neither too large nor too small. If the difference L1-L2 is too small (e.g., less than 6 mm), the jumper wire will easily drift outside the second insulating member 17, and the second insulating member 17 will not be able to block the jumper wire from contacting the cell 111. If the difference L1-L2 is too large (e.g., greater than 10 mm), the width L1 of the second insulating member 17 will be too large, resulting in higher costs. Therefore, the difference L1-L2 should be set within a reasonable range.

[0043] Preferably, the thickness h1 of the second insulating member 17 satisfies: 0.2 mm ≤ h1 ≤ 0.5 mm. For example, the thickness h1 of the second insulating member 17 can be: 0.2 mm, 0.25 mm, 0.3 mm, 0.4 mm, 0.45 mm, 0.5 mm, etc.

[0044] The thickness h1 of the second insulating member 17 should be neither too large nor too small. If the thickness h1 of the second insulating member 17 is too small (for example, less than 0.2 mm), the strength and reliability of the second insulating member 17 will be reduced, the second insulating member 17 will be easily damaged by external forces, and will not be able to effectively block the contact between the jumper wire and the battery cell 111. If the thickness h1 of the second insulating member 17 is too large (for example, greater than 0.5 mm), the cost of the second insulating member 17 will be high. Therefore, the thickness h1 of the second insulating member 17 should be set within a reasonable range.

[0045] Preferably, the second insulating member 17 may include an insulating layer and an adhesive layer. The insulating layer may be made of polyethylene terephthalate (PET), and the adhesive layer may be made of ethylene vinyl acetate copolymer (EVA).

[0046] The width, thickness and material of the first insulating member 16 can be the same as those of the second insulating member 17 , so that the first insulating member 16 and the second insulating member 17 can be cut from the same batch of coils.

[0047] In some other embodiments, the width, thickness, or material of the first insulating member 16 may be partially the same as or completely different from those of the second insulating member 17 .

[0048] Furthermore, the first insulating member 16 and the second insulating member 17 are integrally provided, so that the first insulating member 16 and the second insulating member 17 can be placed together on the sliced ​​cell 111 when assembling the photovoltaic module, thereby simplifying the steps of assembling the photovoltaic module.

[0049] It can be understood that the first insulating member 16 and the second insulating member 17 can also be set separately. When assembling the photovoltaic module, the first insulating member 16 and the second insulating member 17 are respectively placed on the segmented battery cell 111, and a part of the first insulating member 16 and the second insulating member 17 are overlapped to ensure the insulation effect of the first bus bar 12 when the first insulating member 16 and the second insulating member 17 are close to each other.

[0050] The first insulating member 16 provided at one end of the photovoltaic assembly along the second direction Y can be a whole section or multiple sections. When the first insulating member 16 is multiple sections, each section of the first insulating member 16 corresponds to a battery string group.

[0051] In the above embodiments, the length L of the segmented cell 111 satisfies: 180mm≤L≤220mm, and the width W of the segmented cell 111 satisfies: 45mm≤W≤55mm, so that the string length of the battery string 11 formed by multiple segmented cell 111 can meet the creepage distance required by the photovoltaic module, ensuring the normal use of the photovoltaic module. At the same time, the size of the photovoltaic module formed by the four-parallel-three-string arrangement method is close to the size of the photovoltaic module formed by the two-parallel-six-string arrangement method, so that the photovoltaic module in the embodiment of the present application does not require special processes or steps during production or assembly, thereby reducing production costs.

[0052] In the above embodiment, the location where the first jumper 14 and the second bus bar 13 are close together is the first lead-out end, and the location where the second jumper 15 and the second bus bar 13 are close together is the second lead-out end. A first junction box is provided at the first lead-out end, to which both the second bus bars 13 and the first jumper 14 are connected; a second junction box is provided at the second lead-out end, to which one second bus bar 13 and the second jumper 15 are connected. The first junction box and the second junction box are connected to external devices.

[0053] Specifically, such as Figure 5 and Figure 6 As shown, the first jumper 14 has a first lead 14a at the first lead end, and the second bus bar 13 has a second lead 13a at the first lead end. The two second leads 13a and the one first lead 14a are arranged in a herringbone shape.

[0054] Specifically, such as Figure 7 As shown, at the second lead-out end, the second jumper 15 and the second bus bar 13 connected thereto share a third lead (not shown in the figure), and the second bus bar 13 not connected to the second jumper 15 has a fourth lead (not shown in the figure), and the third lead and the fourth lead are spaced apart along the first direction X.

[0055] In the above embodiment, the first bus bar 12 can be folded to the back of the photovoltaic module. Figure 1 and Figure 3 As shown, first, the head of the cell string 11 is connected to the first bus bar 12 via the welding ribbon 112, and the tail of the cell string 11 is connected to the second bus bar 13 via the welding ribbon 112. Then, the first insulating member 16 is placed on the back of the cell photovoltaic module, and the first bus bar 12 is folded to the back of the photovoltaic module using a tool. At this time, the first insulating member 16 is located between the first bus bar 12 and the sliced ​​cell 111.

[0056] Furthermore, when the welding ribbon 112 connected to the first bus bar 12 extends from the front of the photovoltaic module to the first bus bar 12, the welding ribbon 112 is connected to the side of the first bus bar 12 facing the cell 111. In this case, the first bus bar 12 can protect the connection between the welding ribbon 112 and the welding ribbon 112. When the welding ribbon 112 connected to the first bus bar 12 extends from the back of the photovoltaic module to the first bus bar 12, the welding ribbon 112 is connected to the side of the first bus bar 12 facing away from the cell 111. This makes the radius of the bending part of the welding ribbon 112 larger, making the welding ribbon 112 less likely to break. In addition, to prevent the welding ribbon 112 from being too thick, resulting in greater stress on the cell 111 during lamination, the welding ribbon 112 can be tilted relative to the second direction Y so that the welding ribbon 112 before and after the folding do not overlap in the third direction Z.

[0057] It can be understood that the first bus bar 12 can also be directly set on the back of the photovoltaic module. By opening a hole corresponding to the welding ribbon 112 on the first insulating member 16, the first bus bar 12 is in contact with the welding ribbon 112, thereby being electrically connected to the segmented battery cell 111, and there is no need to fold the first bus bar 12.

[0058] In the above embodiments, Figure 2 As shown, the photovoltaic module further includes a first bypass diode 21, a second bypass diode 22 and a third bypass diode 23. For ease of description, the definition Figure 2 From left to right in the figure, there are the first, second, and third battery strings. The first battery string is connected in reverse parallel to a first bypass diode 21 via a first jumper 14, the second battery string is connected in reverse parallel to a second bypass diode 22 via a first jumper 14, and the third battery string is connected in reverse parallel to a third bypass diode 23 via a second jumper 15.

[0059] Specifically, the first bypass diode 21 is connected in reverse parallel with the first battery string group through the first jumper 14 (that is, the first bypass diode 21 is connected in parallel with the first battery string group, but with opposite polarity). When the segmented battery cells 111 on any battery string 11 in the first battery string group are blocked or faulty, and a hot spot effect occurs (that is, the short-circuit current of some segmented battery cells 111 in the photovoltaic module is less than the operating current of the module due to blocking, cracking, etc., causing these segmented battery cells 111 to be in a reverse bias state and consume energy generated by other areas), the first bypass diode 21 can form a forward bias, allowing the current to bypass the blocked or faulty battery string 11 and flow through the first bypass diode 21, without affecting the normal power generation of other battery strings 11 in the first battery string group.

[0060] The second bypass diode 22 is connected in reverse parallel with the second battery string group via the first jumper 14 (i.e., the second bypass diode 22 is connected in parallel with the second battery string group, but with opposite polarity). When a cell 111 on any battery string 11 within the second battery string group is blocked or fails, causing a hot spot effect, the second bypass diode 22 can form a forward bias, allowing current to bypass the blocked or failed battery string 11 and flow through the second bypass diode 22, without affecting the normal power generation of other battery strings 11 within the second battery string group.

[0061] The third bypass diode 23 is connected in reverse parallel with the third battery string group via the second jumper 15 (i.e., the third bypass diode 23 is connected in parallel with the third battery string group, but with opposite polarity). When a cell 111 on any battery string 11 within the third battery string group is blocked or fails, causing a hot spot effect, the third bypass diode 23 can form a forward bias, allowing current to bypass the blocked or failed battery string 11 and flow through the third bypass diode 23, without affecting the normal power generation of other battery strings 11 within the third battery string group.

[0062] Furthermore, the number of segmented battery cells 111 in the first battery string group, the second battery string group and the third battery string group are all the same, so that the number of segmented battery cells 111 in the three battery string groups is equal, and thus the number of segmented battery cells 111 protected by the three bypass diodes is equal, which can improve the working stability of the three bypass diodes and further improve the protection effect of the three bypass diodes on the photovoltaic modules.

[0063] In the above embodiment, the number n of the sliced ​​solar cells 111 included in each battery string 11 satisfies the following: 18 ≤ n ≤ 24. For example, the number n can specifically be 18, 19, 21, 22, 23, 24, etc. The number n of the sliced ​​solar cells 111 included in each battery string 11 should be neither too many nor too few. If the number of sliced ​​solar cells 111 in each battery string 11 is too few (e.g., fewer than 18), the overall size of the photovoltaic module will be too small, making it impossible to assemble using existing photovoltaic module production equipment, and the effective light absorption area of ​​the photovoltaic module will be reduced. If the number of sliced ​​solar cells 111 in each battery string 11 is too many (e.g., more than 24), the overall size of the photovoltaic module will be too large, making it impossible to assemble using existing photovoltaic module production equipment.

[0064] Furthermore, in the battery string 11, the distance d between adjacent battery cells 111 satisfies: -0.5 mm ≤ d ≤ 1.0 mm. For example, the distance d can be -0.5 mm, -0.2 mm, 0, 0.2 mm, 0.5 mm, 0.8 mm, 1.0 mm, etc.

[0065] When the distance d between adjacent solar cells 111 is a negative number, the adjacent solar cells 111 partially overlap, eliminating gaps between the multiple solar cells 111. This increases the area ratio of the solar cells 111 in the photovoltaic module, thereby increasing the effective light absorption area of ​​the photovoltaic module and improving the photovoltaic module's photoelectric conversion efficiency. Specifically, adjacent solar cells 111 can be welded using a lap welding technique.

[0066] When the distance d between adjacent segmented cell panels 111 is 0, the adjacent segmented cell panels 111 abut against each other, so that there is no gap between the multiple segmented cell panels 111, thereby increasing the area ratio of the segmented cell panels 111 in the photovoltaic module, thereby increasing the effective light absorption area in the photovoltaic module and improving the photoelectric conversion efficiency of the photovoltaic module.

[0067] When the distance d between adjacent segmented cell sheets 111 is a number greater than 0, there is a gap between adjacent segmented cell sheets 111. Therefore, the distance d should not be too large (for example, not greater than 1.0 mm), thereby preventing the segmented cell sheets 111 from occupying a small area in the photovoltaic module, resulting in a small effective light absorption area in the photovoltaic module.

[0068] In the above embodiments, Figure 8 As shown, a quarter piece cut from a whole cell includes two edge pieces 111 a and two middle pieces 111 b . Some corners of the edge pieces 111 a are chamfered, and the four corners of the middle pieces 111 b are all right angles.

[0069] Specifically, the area S of a single chamfer on the edge piece 111a satisfies: 0.5mm 2 ≤S≤10mm 2 For example, the area S can be 0.5 mm 2 , 0.8 mm 2 、 1.0mm 2 , 2.0mm 2 , 5 mm 2 , 8 mm 2 , 9 mm 2 , 10 mm 2 wait.

[0070] The area S of a single chamfer on the edge piece 111a should not be too large or too small. If the area S of a single chamfer is too large (for example, greater than 10 mm 2 ), the light receiving area of ​​the split cell 111 will be smaller, affecting the photoelectric conversion efficiency of the photovoltaic module; if the area S of a single chamfer is too small (for example, less than 0.5 mm 2 ), the stress concentration cannot be effectively relieved, causing micro cracks or splits in the cell. Therefore, the area S of a single chamfer on the edge piece 111a should be set within a reasonable range.

[0071] Optionally, the multiple sliced ​​cells 111 in the battery string 11 are all edge cells 111a. The edge cells 111a have fewer cutting edges and less damage. Therefore, the photovoltaic module composed of edge cells 111a has a higher photoelectric conversion efficiency. Optionally, the multiple sliced ​​cells 111 in the battery string 11 are all intermediate cells 111b, thereby reducing the waste caused by the intermediate cells 111b not being used. Optionally, the multiple sliced ​​cells 111 in the battery string 11 include both edge cells 111a and intermediate cells 111b, thereby further reducing the storage pressure and waste of the sliced ​​cells 111 caused by more edge cells 111a or more intermediate cells 111b.

[0072] Optionally, the battery strings 11 in the battery string group are all battery strings 11 composed of edge sheets 111a; optionally, the battery strings 11 in the battery string group are all battery strings 11 composed of middle sheets 111b; the battery strings 11 in the battery string group include both battery strings 11 composed of edge sheets 111a and battery strings 11 composed of middle sheets 111b, and the two are arranged alternately.

[0073] Furthermore, when the plurality of cell slices 111 in the battery string 11 include both edge slices 111a and middle slices 111b, the edge slices 111a and middle slices 111b are arranged alternately to facilitate cell arrangement and string formation. It is understood that the edge slices 111a and middle slices 111b of the battery string 11 may also be randomly distributed or distributed according to other rules.

[0074] In the above embodiments, the types of the sliced ​​cells 111 include, but are not limited to, Passivated Emitter Rear Cells (PERC), Tunnel Oxide Passivated Contact (TOPCON), Heterojunction with Intrinsic Thin-layer (HIT), Perovskite Solar Cells (PSC), etc. The embodiments of the present application do not specifically limit the types of the sliced ​​cells 111 in the photovoltaic module.

[0075] A TOPCon cell, along its thickness, consists of a silver electrode, a front silicon nitride passivation layer, a boron-doped emitter, an N-type base silicon layer, a diffused doped layer, an ultrathin silicon oxide layer, doped polysilicon, silicon nitride, and a silver electrode. The back of the cell consists of an ultrathin silicon oxide layer (1nm-2nm) and a phosphorus-doped microcrystalline amorphous hybrid silicon thin film, which together form a passivated contact structure. This structure blocks minority carrier-hole recombination, improving the cell's open-circuit voltage and short-circuit current. The ultrathin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking minority carrier-hole recombination. The excellent passivation effect of the ultrathin silicon oxide and heavily doped silicon film causes surface band bending of the silicon wafer, creating a field passivation effect. This significantly increases the probability of electron tunneling and reduces contact resistance, thereby increasing the cell's open-circuit voltage and short-circuit current, and thus improving the cell's conversion efficiency.

[0076] For HIT batteries, along their thickness direction, the HIT batteries include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0077] For PERC cells, along the thickness direction, the PERC cell includes the front surface metal silver electrode, the front surface silicon nitride passivation layer, the phosphorus layer emitter, the P-type base silicon layer, the local aluminum back field, the metal aluminum back electrode, the back passivation layer (Al2O3 / SiN x PERC cells use a passivation film to passivate the back surface, replacing the all-aluminum back surface field. This enhances the internal back reflection of light in the silicon substrate, reduces the recombination rate on the back surface, and increases the efficiency of the cell by 0.5%-1%.

[0078] For a PSC cell, along its thickness, the perovskite cell consists of a substrate material, a conductive film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrode with minimal loss. This can generate a high photogenerated voltage and current, making the perovskite exhibit a high photoelectric conversion efficiency.

[0079] In another embodiment, Figure 9 and Figure 10 As shown, the type of the split cell 111 is a back contact cell (BC).

[0080] For BC cells, the emitter, surface field and metal electrode are all set on the back of the cell and cross-distributed. The front of the cell uses a SiNx / SiOx double-layer anti-reflection passivation film, so that the front of the cell is not blocked by the metal electrode, allowing the cell to receive more incident light, reduce optical loss, and improve photoelectric conversion efficiency.

[0081] Since the metal electrodes of the BC battery are all arranged on the back of the segmented battery cell 111, the welding strips 112 connecting the segmented battery cell 111 and the first bus bar 12 are also arranged on the back of the segmented battery cell 111. The welding strips 112 are connected to the side of the first bus bar 12 away from the segmented battery cell 111, so that the radius of the bending part of the welding strips 112 is larger, and thus the welding strips 112 are not easy to break.

[0082] In another embodiment, the cell 111 is a tandem cell, comprising a top cell, an intermediate connecting layer, and a bottom cell, with the intermediate connecting layer connecting between the bottom and top cells. The top cell may be a perovskite cell, a cadmium telluride solar cell, a copper indium gallium selenide solar cell, or a gallium arsenide solar cell; the bottom cell may be a PERC cell, a TOPCON cell, a HIT cell, or a BC cell; the intermediate connecting layer may be selected from a transparent material with a high refractive index, such as a transparent conductive metal oxide film (ITO). An effective intermediate connecting layer requires high light transmittance to reduce light reflection and absorption at the connecting layer interface, as well as good conductivity to reduce the impact of series resistance on device performance.

[0083] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A photovoltaic module, characterized in that: The photovoltaic module comprises three battery string groups connected in series, each of the battery string groups comprises four battery strings (11) connected in parallel, the battery string (11) comprises a plurality of split battery slices (111), and the split battery slices (111) are quarter slices cut from a whole battery slice; The three battery string groups connected in series are distributed along a first direction (X), and the plurality of battery slices (111) in the battery string (11) are distributed along a second direction (Y); The head and tail of the battery string (11) are both connected to bus bars, and the bus bars include: a first bus bar (12) located at both ends of the photovoltaic component along the second direction (Y) and a second bus bar (13) located in the middle of the photovoltaic component along the second direction (Y), and the first bus bar (12) is located on the back of the photovoltaic component.

2. The photovoltaic module according to claim 1, characterized in that A first insulating member (16) is provided between the first bus bar (12) and the segmented battery sheet (111).

3. The photovoltaic module according to claim 2, characterized in that The photovoltaic assembly further includes a jumper extending along the second direction (Y), the jumper being connected to the first bus bar (12) and being located between adjacent battery strings; A second insulating member (17) is provided between the jumper and the segmented battery sheet (111).

4. The photovoltaic module according to claim 3, characterized in that The first insulating member (16) and the second insulating member (17) are integrally provided.

5. The photovoltaic module according to claim 3, characterized in that: The jumper comprises a first jumper (14) not connected to the second bus bar (13) and a second jumper (15) connected to the second bus bar (13); The first jumper (14) has a first lead-out end near the second bus bar (13), and the first lead-out end is provided with a first junction box; the second jumper (15) has a second lead-out end near the second bus bar (13), and the second lead-out end is provided with a second junction box.

6. The photovoltaic module according to claim 1, characterized in that The quarter pieces cut from the whole cell sheet include two edge pieces (111a) and two middle pieces (111b); The plurality of segmented battery cells (111) in the battery string (11) are all edge cells (111a); Or, the plurality of the segmented battery slices (111) in the battery string (11) are all the intermediate slices (111b); Alternatively, the plurality of segmented battery slices (111) in the battery string (11) include both the edge slices (111a) and the middle slices (111b).

7. The photovoltaic module according to claim 6, characterized in that: When the plurality of segmented battery slices (111) in the battery string (11) include both the edge slices (111a) and the middle slices (111b), the edge slices (111a) and the middle slices (111b) are arranged in an alternating manner.

8. The photovoltaic module according to any one of claims 1 to 7, characterized in that: The length L of the segmented battery sheet (111) satisfies: 180 mm ≤ L ≤ 220 mm, and the width W of the segmented battery sheet (111) satisfies: 45 mm ≤ W ≤ 55 mm.

9. The photovoltaic module according to any one of claims 1 to 7, characterized in that: The number n of the segmented battery slices (111) included in each battery string (11) satisfies the following: 18≤n≤24.

10. The photovoltaic module according to any one of claims 1 to 7, characterized in that: In the battery string (11), the distance d between adjacent segmented battery cells (111) satisfies: -0.5 mm ≤ d ≤ 1.0 mm.

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