Solar cell string and solar cell module
By using the connection method between the interconnection strip and the bus bar in the solar cell string, the problems of increased material consumption, reduced efficiency and low aesthetics in the prior art are solved, and a more efficient connection effect and a more beautiful component appearance are achieved.
Patent Information
- Application Number
- CN202421593306.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-05
- Publication Date
- 2025-04-22
- Estimated Expiration
- 2034-07-05
AI Technical Summary
In the existing photovoltaic module manufacturing technology, there are problems such as increasing material consumption, reduced efficiency, and hidden cracking through bus bars and PAD spot welding on the back of the battery cell, and the pulling and distortion caused by cell string displacement affects the aesthetics of the module.
A solar cell string design is adopted, which is connected to the bus bar through the interconnection strip. The bus bar is set to fixed sites and the interconnection strip are fixedly connected. The non-fixed section is erected on the interconnection strip to contact it, avoiding the use of PAD points and auxiliary welding materials.
It reduces the material consumption of a single-piece battery, improves battery efficiency, enhances the connection effect of bus bars, reduces the occurrence of adverse phenomena, and improves the aesthetics of the components.
Smart Images
Figure CN222786251U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of photovoltaic module manufacturing, and in particular to a solar cell string and a solar cell module. Background Art
[0002] The current conventional shingled solar cell module is a full parallel design, using three bypass diodes in parallel in the circuit, and the connection is achieved by welding the bus bars corresponding to the bypass diodes to the PAD points designed separately on the back of the cell.
[0003] However, this method of welding the busbar to the pad point on the back of the cell has the following problems: the setting of the pad point on the back of the cell will increase the material consumption of the single cell and reduce the cell efficiency; in order to ensure the welding effect, auxiliary welding materials such as solder paste or flux need to be added, which will also increase the material consumption; because the busbar and the cell are directly in contact with each other, with the trend of thinning the cell sheet, it will increase the undesirable phenomenon such as hidden cracks in the cell. In addition, as the film flows during the lamination process of the photovoltaic module, the cell string has a slight displacement, resulting in the phenomenon that the head and tail interconnection bars of the cell string and the busbar are pulled and twisted, and the appearance of the module is reduced. Utility Model Content
[0004] The purpose of the embodiments of the present application is to provide a solar cell string and a solar cell module, which do not require PAD points to be set on the surface, nor do they require the addition of auxiliary welding materials, thereby reducing the material consumption of a single cell sheet and improving the battery efficiency; and the bus bar connection effect is good, reducing the occurrence of adverse phenomena; it can also reduce the pulling and twisting phenomenon caused by slight displacement of the battery string, thereby improving the overall aesthetics of the module.
[0005] In a first aspect, an embodiment of the present application provides a solar cell string, which includes at least two sequentially arranged solar cells, two adjacent solar cells are respectively connected by a plurality of interconnection bars, and a bus bar is provided on all the interconnection bars connected to at least one of the solar cells;
[0006] The bus bar includes a plurality of fixed sites arranged at intervals along the length direction and a non-fixed segment connecting two adjacent fixed sites, wherein the fixed site is fixedly connected to the interconnection bar thereunder, at least a portion of the non-fixed segments are laid on the interconnection bar, and the non-fixed segment is not fixedly connected to the interconnection bar thereunder, and the non-fixed segment is in contact with at least a portion of the interconnection bars thereunder.
[0007] In the above implementation process, the battery cells are connected to the busbars through the interconnection bars. There is no need to set PAD points on the surface of the battery cells, nor is there any need to add auxiliary welding materials such as solder paste or flux. Therefore, the process window is large, and the material consumption of the single battery cell can be reduced, and the battery efficiency is improved; the fixed positions of the busbars are fixedly connected to the corresponding interconnection bars, and the non-fixed sections of the busbars are in contact with the corresponding interconnection bars. Not only are there many contact points of the busbars, the connection effect is good, and the heating problem can be reduced, but the overall surface is relatively flat, and the stress on the battery cells is relatively small, which can reduce the occurrence of adverse phenomena. Even if the battery cells are thin, the overall fragmentation rate during lamination is low. In addition, the above-mentioned arrangement and connection method of the interconnection bars and the busbars can release the pulling force of the film flow on the battery string during the lamination process, reduce the pulling and twisting phenomenon of the interconnection bars and the busbars, and improve the overall aesthetics of the component.
[0008] In a possible implementation, the bus bar is located on the battery, and each of the fixed locations is fixedly connected to a corresponding location of the battery cell via the interconnection bar thereunder.
[0009] In the above implementation process, the bus bar is located on the battery and is fixedly connected to the interconnection bar which is also located on the battery. The fixed connection effect between the bus bar and the interconnection bar is good.
[0010] In a possible implementation, each of the fixing sites is fixedly connected to one of the interconnection bars thereunder.
[0011] In the above implementation process, each fixed position is fixedly connected to an interconnection bar, which makes it easy to achieve a fixed connection between the bus bar and the interconnection bar.
[0012] In a possible implementation manner, the number of the interconnection bars arranged below the non-fixed segments on the interconnection bars is 1 to 3.
[0013] In the above implementation process, the number of fixing sites can be controlled to achieve a good fixing connection effect between the bus bar and all interconnection bars.
[0014] In a possible implementation manner, the non-fixed segment arranged on the interconnection bar contacts all the interconnection bars thereunder.
[0015] In the above implementation process, the connection effect between the non-fixed section of the bus bar and the interconnection bar is good, and it is not easy to break during lamination.
[0016] In a possible implementation manner, at least a portion of the non-fixed segments located between adjacent interconnection bars are recessed toward the battery cell.
[0017] In the above implementation process, the recessed position of the non-fixed section of the busbar is equivalent to a reserved free section, which can release the stress caused by the thermal expansion and contraction of the busbar (for example, when the busbar is welded to the interconnection bar) and prevent the pulling and displacement caused by the contraction of the busbar. Therefore, the busbar is not easy to break and does not affect the lamination process.
[0018] In a possible implementation manner, a portion of the non-fixed segment that contacts the interconnection bar has a folded portion, and the folded portion is not higher than a surface of the bus bar.
[0019] In the above implementation process, the folded portion of the non-fixed segment of the busbar is equivalent to a free segment, so that the entire busbar is not easy to break and does not affect the lamination process.
[0020] In a possible implementation, the busbar is made of tinned copper strip, the thickness of the busbar is 0.05 to 0.15 mm, and the width of the busbar is 5 to 15 mm;
[0021] The interconnection strip is made of tinned copper strip, and the diameter of the interconnection strip is 0.15-0.3 mm.
[0022] In the above implementation process, the fixed position can be directly welded with the interconnection bar, which can ensure the melting of the tin layer and the contact welding effect, and can also improve the contact effect between the non-fixed segment and the bus bar.
[0023] In a second aspect, an embodiment of the present application provides a solar cell assembly, comprising a plurality of solar cell strings provided in the first aspect, wherein the bus bars of all the solar cell strings are connected in sequence. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0025] Figure 1 A schematic structural diagram of a solar cell string provided in the first embodiment;
[0026] Figure 2 for Figure 1 Schematic diagram of the middle structure;
[0027] Figure 3 for Figure 2 A schematic diagram of the structure of a battery cell with a bus bar;
[0028] Figure 4 for Figure 3A schematic diagram of the structure from another perspective;
[0029] Figure 5 A schematic structural diagram of a solar cell having a bus bar in a solar cell string provided in a second embodiment;
[0030] Figure 6 A schematic structural diagram of a solar cell having a bus bar in a solar cell string provided in a third embodiment;
[0031] Figure 7 A schematic structural diagram of a solar cell assembly provided in the fourth embodiment.
[0032] Icon: 100 - battery string; 110 - battery cell; 120 - interconnection bar; 130 - bus bar; 131 - fixed site; 132 - first non-fixed segment; 133 - second non-fixed segment. DETAILED DESCRIPTION
[0033] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.
[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0035] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.
[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0037] In the description of this application, it should be noted that the terms "upper", "lower", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.
[0038] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0039] First embodiment
[0040] Please see Figure 1 , Figure 2 and Figure 3 , Figure 4 The present embodiment provides a solar cell string 100, which includes at least two cells 110 arranged in sequence, wherein two adjacent cells 110 are connected by a plurality of interconnection bars 120, respectively, and a bus bar 130 is arranged on all interconnection bars 120 connected to at least one cell 110; the bus bar 130 includes a plurality of fixed sites 131 arranged at intervals along the length direction and a non-fixed segment connecting two adjacent fixed sites 131, wherein the fixed site 131 is fixedly connected to the interconnection bar 120 thereunder, and at least a portion of the non-fixed segments are laid on the interconnection bar 120, and the non-fixed segments are not fixedly connected to the interconnection bar 120 thereunder, and the non-fixed segments are in contact with at least a portion of the interconnection bars 120 thereunder.
[0041] In the embodiment of the present application, the bus bar 130 in the solar cell string 100 is set at a location where a bus bar 130 is set on the interconnection bar 120 on a certain cell. Generally, the solar cell string 100 is set with a bus bar 130. Of course, two or more bus bars 130 can also be set according to the needs. The cell 110 has a front and a back, and the front and the back refer to the two opposite surfaces of the cell 110. The front refers to the surface facing the sun in actual use, and the back refers to the surface away from the sun. As an embodiment, the connection between two adjacent cells 110 through the interconnection bar 120 means that the front (positive electrode) of a cell 110 is connected to the back (negative electrode) of the adjacent cell 110 through the interconnection bar 120. The connection method of the solar cell string 100 is that the front of the first cell 110 is connected to the back of the second cell 110 through the interconnection bar 120, and the front of the second cell 110 is connected to the back of the third cell 110 through the interconnection bar 120. As an embodiment, the bus bar 130 is located on the back side of the middle battery cell 110 and is welded to the back side of the interconnection bar 120 located on the back side. Figure 1 , Figure 2 and Figure 3 The figure shows the connection status of the back side of the battery cell 110. Figure 1 The dots in the figure represent battery cells not shown.
[0042] In the embodiment of the present application, the fixed position 131 of the bus bar 130 refers to a position fixed together with the corresponding interconnection bar 120 in a fixed manner, and the fixed position 131 and the interconnection bar 120 will not be separated during the conventional process and use; the non-fixed sections of the bus bar 130 are divided into two types, one is the first non-fixed section 132, under which there is an interconnection bar 120 (mounted on the interconnection bar 120), this non-fixed section is not fixed by any fixing method or is not welded, and the non-fixed section and the corresponding interconnection bar 120 can be separated; the other is the second non-fixed section, under which there is no interconnection bar 120, and this non-fixed section will definitely not be connected or contacted with the interconnection bar 120.
[0043] Exemplarily, the fixing methods include welding and bonding. The welding method is to weld the bus bar 130 and the interconnection bar 120 together through mainstream welding methods such as infrared heating, electromagnetic heating or hot air welding; the bonding method is to use glue to bond, such as conductive glue, insulating glue, thermosetting glue and ultraviolet glue. Different glues have different curing conditions. Conductive glue, insulating glue, and thermosetting glue need to be heated or cured during the lamination process, and ultraviolet glue needs to be cured by ultraviolet light or heating.
[0044] The non-fixed section may not be fixed, or by using a low-temperature bus bar 130 or a low-temperature interconnect bar 120 (such as SnPbBi, SnBiAg and other alloys) with a lower melting point, melting and solidification will occur during the lamination process, and after lamination, the bus bar 130 and the interconnect bar 120 form a good physical contact.
[0045] In some embodiments of the present application, the battery cell 110 may be formed by cutting a 182 mm silicon wafer into two or three pieces; in some other embodiments of the present application, the battery cell 110 may also be formed by cutting a 210 mm silicon wafer into two or three pieces.
[0046] In some embodiments of the present application, the battery cells 110 are arranged in parallel (without overlapping) along the arrangement direction, and the electrical connection between the battery cells 110 is achieved through the interconnection bars 120 .
[0047] In some embodiments of the present application, the material of the bus bar 130 is tinned copper strip or other conductive materials, the thickness of the bus bar 130 is 0.05 mm-0.15 mm, and the width of the bus bar 130 is 5 mm-15 mm;
[0048] The interconnection bar 120 is made of tinned copper strip or other conductive materials, and the diameter of the interconnection bar 120 is 0.15-0.3 mm.
[0049] In some embodiments of the present application, the bus bar 130 is located on the battery, and each fixed site 131 is fixedly connected to the corresponding position of the battery cell 110 through the interconnection bar 120 below it. The number of fixed sites 131 is usually 4 to 20, thereby ensuring the current carrying capacity and connection strength of the bus bar 130 and the interconnection bar 120. In some embodiments of the present application, the number of interconnection bars 120 arranged below the non-fixed section on the interconnection bar 120 is 1 to 3.
[0050] In this embodiment, each fixed point 131 is fixedly connected to an interconnection bar 120 below it, specifically through welding connection, the interconnection bar 120 corresponding to the fixed point 131 is not continuously arranged, and no second non-fixed section is arranged; the number of interconnection bars 120 below each non-fixed section (first non-fixed section 132) arranged on the interconnection bar 120 is 2; each non-fixed section (first non-fixed section 132) arranged on the interconnection bar 120 is in contact with all interconnection bars 120 below it. From the overall point of view, the bus bar 130 is in a straight state, the fixed point 131 of the bus bar 130 is fixedly connected to the interconnection bar 120, and the non-fixed section is in contact with the interconnection bar 120. In other embodiments, the number of interconnection bars 120 under each non-fixed segment (first non-fixed segment 132) is 3 or more; in other embodiments, each non-fixed segment (first non-fixed segment 132) contacts some interconnection bars 120 under it, but does not contact other interconnection bars 120, for example, it is at a distance from the interconnection bars 120. In other embodiments, the bus bar 130 may also be bent on the surface of the battery cell, which can also reduce the stress of the bus bar 130.
[0051] Second embodiment
[0052] Please see Figure 5 The present embodiment provides a solar cell string, which is different from the first embodiment in that at least a portion of the non-fixed segments located between adjacent interconnecting bars 120 are recessed toward the direction of the solar cell 110, and the connection between the recessed position and other positions is configured as a chamfer, a right angle or a rounded corner. In the present embodiment, the portion of each non-fixed segment (first non-fixed segment 132) located between adjacent interconnecting bars 120 is recessed toward the direction of the solar cell 110.
[0053] In other embodiments, the busbar 130 with excess length may be folded after lamination. Specifically, the portion of the non-fixed section in contact with the interconnection bar 120 may also have a folded portion, which is not higher than the surface of the busbar 130 .
[0054] Third embodiment
[0055] Please see Figure 6The present embodiment provides a solar cell string, which differs from the first embodiment in that: some adjacent interconnecting bars 120 are respectively connected with fixed sites 131, and some adjacent interconnecting bars 120 are provided with non-fixed sections, which are in contact with the interconnecting bars 120 below. In the present embodiment, the bus bar 130 is fixed to two consecutive interconnecting bars 120 to form two fixed sites 131, and the non-fixed section between the two fixed sites 131 is the second non-fixed section 133, which is in a straight state. The bus bar 130 is then provided on two consecutive interconnecting bars 120 to form a circulation unit, and the subsequent bus bars 130 are repeatedly provided according to the circulation unit. The non-fixed section provided on the interconnecting bar 120 is the first non-fixed section 132, and there are two interconnecting bars 120 below it. The part of the non-fixed section located between the adjacent interconnecting bars 120 is recessed toward the direction of the battery cell 110.
[0056] Fourth embodiment
[0057] Please see Figure 7 The present embodiment provides a solar cell assembly, comprising a plurality of solar cell strings of the first embodiment, wherein the solar cell strings are arranged in parallel, wherein the bus bars 130 of the solar cell strings are connected in sequence, and the non-fixed section of the bus bar 130 refers to the area where the bus bar 130 is not fixed by welding. Figure 7 The dots in the figure represent cells not shown. In this embodiment, the same bus bar 130 connects all solar cell strings; in other embodiments, the bus bar 130 of each solar cell string may be independently provided and then connected together.
[0058] In summary, the surface of the solar cell string and solar cell module of the embodiment of the present application does not need to be set with PAD points, nor does it need to add auxiliary welding materials, which can reduce the material consumption of a single cell and improve the battery efficiency; the bus bar has a good connection effect and reduces the occurrence of adverse phenomena; it can also reduce the pulling and twisting caused by slight displacement of the battery string, thereby improving the overall aesthetics of the module.
[0059] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A solar cell string, characterized in that: It comprises at least two battery cells arranged in sequence, two adjacent battery cells are respectively connected by a plurality of interconnection bars, and a bus bar is arranged on all the interconnection bars connected to at least one of the battery cells; The bus bar includes a plurality of fixed sites arranged at intervals along the length direction and a non-fixed segment connecting two adjacent fixed sites, wherein the fixed site is fixedly connected to the interconnection bar thereunder, at least a portion of the non-fixed segments are laid on the interconnection bar, and the non-fixed segment is not fixedly connected to the interconnection bar thereunder, and the non-fixed segment is in contact with at least a portion of the interconnection bars thereunder.
2. The solar cell string according to claim 1, characterized in that: The bus bar is located on the battery, and each of the fixed locations is fixedly connected to a corresponding position of the battery sheet through the interconnection bar thereunder.
3. The solar cell string according to claim 1 or 2, characterized in that: Each of the fixing points is fixedly connected to one of the interconnection bars below it.
4. The solar cell string according to claim 1, characterized in that: The number of the interconnection bars below the non-fixed segments arranged on the interconnection bars is 1 to 3.
5. The solar cell string according to claim 1 or 4, characterized in that: The non-fixed section arranged on the interconnection bar is in contact with all the interconnection bars thereunder.
6. The solar cell string according to claim 1, characterized in that: At least a portion of the non-fixed segments located between adjacent interconnection bars are recessed toward the battery cell.
7. The solar cell string according to claim 1, characterized in that: The portion of the non-fixed segment in contact with the interconnection bar has a folded portion, and the folded portion is not higher than the surface of the bus bar.
8. The solar cell string according to claim 1, characterized in that: The material of the busbar is tinned copper strip, the thickness of the busbar is 0.05-0.15 mm, and the width of the busbar is 5-15 mm.
9. The solar cell string according to claim 1, characterized in that: The interconnection strip is made of tinned copper strip, and the diameter of the interconnection strip is 0.15-0.3 mm.
10. A solar cell module, characterized in that: It comprises a plurality of solar cell strings according to any one of claims 1 to 9, wherein the bus bars of all the solar cell strings are connected in sequence.