Bus bar, photovoltaic module and photovoltaic system

Abstract

The utility model is suitable for the field of photovoltaic technology, and provides a bus bar, a photovoltaic assembly and a photovoltaic system. The bus bar comprises a body, the body comprises a plurality of welding sections, the welding sections are used for being connected with a plurality of welding strips in a one-to-one correspondence mode, at least part of the surface of each welding section is provided with a plurality of protrusions, and the protrusions are used for being connected with the welding strips. According to the bus bar, the protrusions are arranged on the surface of the body, when the bus bar is welded with a welding strip, due to the fact that the area of each protrusion is small, the contact area between the bus bar and the welding strip is increased, the situation that contact between structures of an incomplete fusion area or a fusion alloy layer is not uniform is reduced, the structural strength of the welding position is improved, and the service life of the bus bar is prolonged. And therefore, the tensile force after welding is improved, and the product yield is improved.

Description

Technical Field

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

[0002] Solar cells, also known as photovoltaic cells, are devices that directly convert light energy into direct current using the photovoltaic effect. The PN junction on the semiconductor in a solar cell can directly convert solar energy into electrical energy through the photovoltaic effect. The most common type is the crystalline silicon solar cell, which includes monocrystalline silicon solar cells and polycrystalline silicon solar cells.

[0003] During solar cell production, multiple cells are connected in series using solder ribbons, which are then welded to busbars to collect and discharge current. However, because the solder ribbons and busbars are made of different materials, their melting temperatures differ during welding, resulting in low welding tensile strength and poor weld quality. Utility Model Content

[0004] The busbar, photovoltaic module, and photovoltaic system provided in this embodiment of the present invention aim to solve the problem of poor welding of busbars and solder strips in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a busbar, comprising:

[0006] The body includes multiple welding segments, which are connected one-to-one with multiple welding strips. At least a portion of the surface of each welding segment is provided with multiple protrusions, which are used to connect with the welding strips.

[0007] Furthermore, each of the welded segments includes a rough portion and a smooth portion, and the surface of the rough portion is provided with the protrusions.

[0008] Furthermore, along the length direction of the busbar, the width b1 of the rough portion is greater than or equal to 1.5 times the width b2 of the solder strip.

[0009] Furthermore, along the width direction of the body, the length a2 of the rough portion is greater than or equal to half the width a1 of the body.

[0010] Furthermore, the surface of each welded section is provided with the protrusions.

[0011] Furthermore, the protrusions are provided on both opposite surfaces of the welded section.

[0012] Furthermore, the protrusion is one or more of the following: arc-shaped protrusion, block-shaped protrusion, wavy protrusion, or irregular protrusion.

[0013] Furthermore, the protrusions are formed through an embossing process.

[0014] Furthermore, the height range of the protrusion is 1μm≤d≤25μm.

[0015] Secondly, this utility model embodiment provides a photovoltaic module, including: a solder strip; and the busbar described above, wherein the busbar and the solder strip are connected.

[0016] Thirdly, this utility model provides a photovoltaic system including the photovoltaic module described above.

[0017] The beneficial effects achieved by this utility model are:

[0018] By setting multiple protrusions on the surface of the welding section of the busbar, the contact area with the welding strip is increased when welding with the welding strip because the area of ​​each protrusion is small. This reduces the uneven contact between the unfused areas or the structure of the fused alloy layer, improves the structural strength of the welding position, and thus increases the tensile strength after welding, thereby improving the product yield. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a busbar provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of a busbar provided in another embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram showing the connection between the busbar and the solder strip in an embodiment of the utility model;

[0022] Figure 4 This is a cross-sectional schematic diagram of the busbar according to an embodiment of the present invention.

[0023] Explanation of key component symbols: 100-busbar, 10-body, 11-soldering section, 111-smooth part, 112-rough part, 12-protrusion, 13-groove, 14-substrate, 15-tin alloy layer, 200-solder strip. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0025] Briefly describe the distinguishing features between this utility model and the prior art; these distinguishing features constitute the utility model's inventive point.

[0026] Example 1

[0027] Solar cells, also known as photovoltaic cells, mainly consist of a substrate, cell arrays, and glass. Cell arrays include multiple sets of cells connected in parallel, and each cell array includes multiple cells arranged in parallel. The cells in a cell array are connected by multiple solder strips 200. Each series of cells is connected by a busbar 100 to achieve concentrated current output.

[0028] It should be noted that both the welding strip 200 and the busbar 100 are made of metal. When the metals are welded, under heating and / or pressure, atomic bonding occurs between the two metals of the same or different types, thereby achieving the welding effect.

[0029] In related technologies, the solder ribbon 200 and busbar 100 mainly consist of a substrate 13 and a tin alloy layer 14. The substrate 13 primarily functions as a conductor; it is typically made of metals such as copper or aluminum, possessing good conductivity, structural strength, and corrosion resistance. It can withstand high voltage and high current and operate within a wide range of temperature and humidity conditions, making it a suitable material for the substrate. The tin alloy layer 14 primarily enables the solder ribbon 200 and busbar 100 to be solderable, allowing for stable welding to achieve conductivity. The tin alloy layer can be uniformly coated onto the substrate surface using processes such as electroplating, vacuum deposition, spraying, and hot-dip coating.

[0030] In particular, because the doped metals of the tin alloy layer 15 on the surface of the solder strip 200 and the busbar 100 are different, the melting temperatures of the two are different. When the difference in melting temperature between the two is ≥ 30℃, and because the size of the solder strip 200 is very small and the contact area between it and the busbar 100 is small, the welding pull between the two is low, resulting in poor welding between the two.

[0031] To resolve the above technical issues, please refer to Figures 1 to 4 The busbar 100 provided in this embodiment of the utility model includes a body 10, which includes a substrate 13 and a tin alloy layer 14.

[0032] The body 10 includes multiple welding segments 11, which are connected one-to-one with multiple welding strips 200. At least a portion of the surface of each welding segment 11 is provided with multiple protrusions 12, which are used to connect with the welding strips 200.

[0033] The aforementioned busbar 100, by providing multiple protrusions 12 on the surface of the welding section 11 of the busbar 100, increases the contact area with the welding strip 200 when welding with the welding strip 200 due to the small area of ​​each protrusion 12. This reduces uneven contact between the unfused areas or the structure of the fused alloy layer, improves the structural strength of the welding position, and thus enhances the tensile strength after welding, thereby improving the product yield.

[0034] In this embodiment, the thickness of the body 10 can be set to 0.1-0.4mm, for example, 0.1mm, 0.2mm, 0.3mm or 0.4mm. This ensures that the thickness of the busbar 100 is within a suitable range, avoiding the problem that a thin body 10 would result in poor strength and conductivity of the entire busbar 100, and also avoiding the waste of materials and increased costs caused by a thick body 10.

[0035] The thickness of the tin alloy layer 15 is 3μm-25μm. For example, it can be set to values ​​such as 3μm, 7μm, 9μm, 11μm, 13μm, 15μm, 20μm, or 25μm, and is not limited here. This ensures that the thickness of the tin alloy layer 15 is within a suitable range, avoiding poor soldering results due to an excessively thin tin alloy layer, and also avoiding material waste and increased costs due to an excessively thick tin alloy layer. The material of the tin alloy layer 15 includes, but is not limited to, at least one of SnPb, SnBi, and SnAg layers, and is not specifically limited here.

[0036] It should be noted that, since multiple solder strips 200 are spaced apart along the length x of the body 10 when soldering the solder strips 200 onto the body 10, thus setting the body 10 into multiple welding segments 11, in one embodiment, protrusions 12 can be provided on the entire surface of the welding segment 11, or protrusions 12 can be provided on a portion of the surface of each welding segment 11, that is, a portion is a smooth portion 111 and a portion is a rough portion 112. No protrusions 12 are provided on the smooth portion 111, and multiple protrusions 12 are provided on the rough portion 112. The rough portion 112 is used for soldering with the solder strips 200, and the smooth portion 111 is separated between the solder strips 200; in another embodiment, protrusions 12 can be provided on the entire surface of each welding segment 11.

[0037] Example 2

[0038] Please see Figure 1 and Figure 3This is a schematic diagram of the structure of a busbar 100 according to an embodiment of the present utility model. Each welding segment 11 includes a smooth portion 111 and a rough portion 112. The surface of the rough portion 112 is provided with protrusions 12, that is, protrusions 12 are only provided in the area where welding with the welding strip 200 is required, and no protrusions 12 are provided in the area where welding with the welding strip 200 is not required, thereby reducing the production cost of providing protrusions 12 on the surface of the busbar 100.

[0039] Furthermore, since each welding segment 11 includes a smooth portion 111 and a rough portion 112, when the body 10 includes multiple welding segments 11, the rough portion 112 can be positioned at the end of the smooth portion 111 along the length x direction of the body 10. In this case, when the entire body 10 is configured, a smooth portion 111 and a rough portion 112 are alternately arranged in sequence; or each rough portion 112 can be positioned in the middle region of the smooth portion 111, in which case the smooth portions 111 are connected to each other.

[0040] Example 3

[0041] Furthermore, such as Figure 3 As shown, when each welding segment 11 is configured to include a smooth portion 111 and a rough portion 112, in order to ensure the welding strength with the welding strip 200, along the length direction x of the busbar 100, the width b1 of the rough portion 112 is ≥ 1.5 times the width b2 of the welding strip 200. Since the welding strip 200 may be misaligned when it is placed on the body 10 and welded to the body 10, it should be welded perpendicularly to the body 10, i.e., the length direction of the welding strip 200 is parallel to the width direction y of the body 10. However, when the welding strip 200 is misaligned, there may be an acute angle between the welding strip 200 and the length direction and the width direction y of the body 10. Therefore, the width b1 of the rough portion 112 is set to be ≥ 1.5 times the width b2 of the welding strip 200 to ensure the connection area with the welding strip 200, thereby ensuring the connection strength.

[0042] For example, the width b1 of the rough portion 112 can be set to a value that is 1.5 times, 1.8 times, or 2.0 times the width b2 of the solder strip 200, etc., and there is no limitation here.

[0043] For example, in some embodiments, when the width b2 of the solder strip 200 is 6 mm and the width b1 of the rough portion 112 is set to 1.5 times the width b2 of the solder strip 200, the width b1 of the rough portion 112 is 9 mm; when the width b2 of the solder strip 200 is 6 mm and the width b1 of the rough portion 112 is set to 2 times the width b2 of the solder strip 200, the width b1 of the rough portion 112 is 12 mm.

[0044] Example 4

[0045] Furthermore, when each welding segment 11 is configured to include a smooth portion 111 and a rough portion 112, in order to ensure the welding strength with the welding strip 200, the length a2 of the rough portion 112 is greater than or equal to half the width a1 of the busbar 100 along the width direction y of the body 10. Thus, by setting this length, it can be ensured that the body 10 and the welding strip 200 have sufficient connection length along the width direction y of the body 10, that is, sufficient contact area, thereby ensuring the connection strength of the weld.

[0046] In some embodiments, the length a1 of the rough portion 112 of the welding portion 112 along the width direction y of the body 10 can be set to be exactly equal to the length of the welding strip 200 to be connected, or it can be set to be greater than the length of the welding strip 200 to be connected, which is not limited here.

[0047] Example 5

[0048] Please see Figure 2 The diagram below shows the structure of a busbar 100 according to an embodiment of the present invention. In this embodiment, the surface of the welding section 11 is provided with protrusions 12. Thus, there is no need to distinguish between areas where protrusions 12 do not need to be designed and areas where protrusions 12 need to be set. Protrusions 12 can be directly set on the entire surface of the body 10, which improves the convenience of setting protrusions 12 on the surface of the body 10 and thus improves production efficiency.

[0049] Example 6

[0050] Furthermore, when a protrusion 12 is provided on the surface of the body 10, the protrusion 12 can be provided on the welding surface of the body 10 where it needs to be welded to the welding strip 200, or the protrusion 12 can be provided on both surfaces of the welding strip 200.

[0051] Specifically, in this embodiment, since the busbar 100 is stored in a wound manner when it is manufactured and before it is welded to the solder strip 200, protrusions 12 are provided on both opposite surfaces of the welding section 11 to facilitate the winding of the busbar 100. This eliminates the need to distinguish between the inner and outer surfaces of the busbar 100 during winding. At the same time, it is not necessary to distinguish the surfaces with protrusions 12 when welding with the solder strip 200, thereby improving welding efficiency.

[0052] Understandably, when a protrusion 12 is provided on a portion of the surface of the welding segment 11, a protrusion 12 can be designed on each surface of the welding segment 11; or when a protrusion 12 is provided on the entire surface of the welding segment 11, a protrusion 12 can be provided on each surface of the welding segment 11.

[0053] Example 7

[0054] When protrusions 12 are provided on the surface of the welding section 11, the shapes of the protrusions 12 can be the same or different. For example, they can be one or more of the following: arc-shaped protrusions 12, block-shaped protrusions 12, wavy protrusions 12, or irregular protrusions 12. That is, only one type of protrusion 12 can be provided on the surface of the welding section 11, or multiple types of protrusions 12 can be combined. In this way, by setting the protrusions 12, the welding yield between the welding section 11 and the welding strip 200 can be improved.

[0055] Among them, the arc-shaped protrusion 12 can be a hemispherical protrusion 12, the block-shaped protrusion 12 can be a square, rectangle, trapezoid, or a serrated protrusion 12.

[0056] In a preferred embodiment, in order to facilitate the setting of the rough section and reduce the opening cost, when the protrusions 12 are set on the rough section, the protrusions 12 are all the same shape, thereby facilitating the forming of the protrusions 12.

[0057] Example 8

[0058] In one embodiment of this utility model, when forming the protrusion 12 on the welding section 11, the protrusion 12 is formed by an embossing process. In this way, pressure can be directly applied to the body 10 to deform the body 10 and form a concave-convex pattern, thus quickly forming the protrusion 12. Furthermore, when the protrusion 12 is formed by the embossing process, the pressure can deform the tin alloy layer 15, or it can also cause the substrate 13 to deform simultaneously.

[0059] Alternatively, in some other embodiments, when protrusions 12 are provided on the welding section 11, they can be formed by a sanding process, such as by sandblasting, electroplating, or electrophoresis, to form a new protrusion layer on each welding section 11. Understandably, the protrusion layer is provided on the surface of the tin alloy layer 15. Since the protrusion layer consists of multiple particles provided on the surface of the tin alloy layer 15, these particles are protrusions 12, and there are also grooves 13 between the particles.

[0060] Example 9

[0061] Please refer to Figure 4When the protrusion 12 is formed on the surface of the welding section 11 by embossing, since the thickness of the busbar 100 ranges from 0.1 to 0.4 mm and the thickness of the tin alloy layer 15 ranges from 3 μm to 25 μm, the height range of the protrusion 12 in this embodiment is set to 1 μm ≤ d ≤ 25 μm. Since the groove 13 is formed simultaneously with the protrusion 12, the depth range of the groove 13 is 1 μm ≤ d ≤ 25 μm. For example, the height of the protrusion 12 can be set to 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, or 25 μm, etc., and is not limited here. Correspondingly, by setting the depth of the groove 13 to 1 μm ≤ d ≤ 25 μm, the depth of the groove 13 is less than or equal to the thickness of the tin alloy layer 15. This avoids reducing the structural strength of the entire busbar 100 when the groove 13 is too deep, and avoids failing to achieve a good fusion effect when welding with the solder strip 200 when the depth is too shallow.

[0062] The aforementioned busbar 100 ensures sufficient contact area during welding with the welding strip 200 by setting the width b1 of the rough portion 112 in the welding section 11 to be ≥ 1.5 times the width b2 of the welding strip 200, thereby ensuring connection strength. Setting the length a2 of the rough portion 112 to be ≥ 1 / 2 of the width a1 of the busbar 100, along the width direction y of the body 10, ensures sufficient connection length between the body 10 and the welding strip 200, i.e., sufficient contact area, thereby ensuring welding connection strength. By providing protrusions 12 on the entire surface of the welding section 11, it is unnecessary to distinguish between areas with and without protrusions 12, thus improving the efficiency of providing protrusions 12 on the surface of the body 10. This improves convenience and thus increases production efficiency. By providing protrusions 12 on both opposite surfaces of the welding section 11, it is not necessary to distinguish between the inner and outer surfaces of the busbar 100 during winding. At the same time, when welding with the solder strip 200, it is not necessary to distinguish the surface where the protrusions 12 are provided, thereby improving welding efficiency. By setting the height range of the protrusions 12 to 1μm≤d≤25μm, that is, the depth range of the groove 13 between the protrusions 12 is 1μm≤d≤25μm, and the depth of the groove 13 is less than or equal to the thickness of the tin alloy layer 15, it is avoided that if the groove 13 is set too deep, it will reduce the structural strength of the entire busbar 100, and if the depth is too shallow, it will not achieve a good fusion effect when welding with the solder strip 200.

[0063] Example 10

[0064] In the tenth embodiment of this utility model, a photovoltaic module is provided, including a solder strip 200 and the busbar 100 described above.

[0065] The welding strip 200 is used to connect multiple battery cells into a battery string. Each string of battery cells is connected in series through the bus bar 100, thereby achieving centralized current output.

[0066] Furthermore, the photovoltaic module also includes a panel, photovoltaic glass, and encapsulant film. The solar cells, solder ribbon 200, and busbar 100 are sandwiched between the backsheet and the photovoltaic glass. An encapsulant film is provided on both the upper and lower surfaces of the solar cells to isolate them from water and oxygen. As a filler, it can be a transparent colloid with good light transmittance and aging resistance to avoid affecting the absorption of light by the solar cells.

[0067] Photovoltaic glass can be applied to the encapsulation layer on the front of the solar cell. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of ultra-clear glass can reach more than 92%, which can protect the solar cell without affecting its efficiency as much as possible.

[0068] The backsheet can be attached to the adhesive film on the back of the solar cells. The backsheet protects and supports the cells, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite adhesive film, etc. The specific choice depends on the specific circumstances and is not limited here. The entire assembly, consisting of the backsheet, solar cells, adhesive film, and photovoltaic glass, can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire photovoltaic module, providing stable support and installation. For example, the solar module can be installed at the desired location using the metal frame.

[0069] In the aforementioned photovoltaic module, the surface of the busbar 100, which collects the current from the solar cells, is provided with protrusions 12. When the busbar 100 is welded to the solder ribbon 200, the contact area with the solder ribbon 200 is increased, reducing the uneven contact between unfused areas or the structure of the fused alloy layer, improving the structural strength of the welding position, increasing the tensile strength after welding, improving the product yield, and thus improving the stability of the photovoltaic module in use.

[0070] Example 11

[0071] In the eleventh embodiment, this utility model also provides a photovoltaic system, including the aforementioned photovoltaic module.

[0072] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios for photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be an array combination of multiple photovoltaic modules; for example, multiple photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter, converts it into AC power required by the mains grid, and then connects to the mains grid to achieve solar power supply.

[0073] In the aforementioned photovoltaic system, the surface of the busbar 100, which collects the current from the solar cells, is provided with protrusions 12. When the busbar 100 is welded to the solder ribbon 200, the contact area with the solder ribbon 200 is increased, reducing the uneven contact between unfused areas or the structure of the fused alloy layer. This improves the structural strength of the welding position, increases the tensile strength after welding, improves the product yield, and thus improves the stability of the photovoltaic module and ensures the stability of the photovoltaic system.

[0074] It is understood that those skilled in the art can combine various implementation methods in the above embodiments under the guidance of the above examples to obtain technical solutions with multiple implementation methods.

[0075] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A busbar, characterized in that, include: The body includes multiple welding segments, which are connected one-to-one with multiple welding strips. At least a portion of the surface of each welding segment is provided with multiple protrusions for connecting with the welding strips. Each welding segment includes a rough portion and a smooth portion. The surface of the rough portion is provided with the protrusions. Along the length direction of the busbar, the width b1 of the rough portion is greater than or equal to 1.5 times the width b2 of the welding strip.

2. The busbar as described in claim 1, characterized in that, Along the width direction of the body, the length a2 of the rough portion is greater than or equal to half the width a1 of the body.

3. The busbar as described in claim 1, characterized in that, The surface of each welded section is provided with the aforementioned protrusions.

4. The busbar as described in claim 1, characterized in that, The protrusions are provided on both opposite surfaces of the welded section.

5. The busbar as described in claim 1, characterized in that, The protrusion is one or more of the following: arc-shaped protrusion, block-shaped protrusion, wavy protrusion, or irregular protrusion.

6. The busbar as described in claim 1, characterized in that, The protrusions are formed by an embossing process.

7. The busbar as described in claim 6, characterized in that, The height range of the protrusion is 1μm≤d≤25μm.

8. A photovoltaic module, characterized in that, include: Welding strip; The busbar as described in any one of claims 1-7, wherein the busbar and the solder strip are connected.

9. A photovoltaic system, characterized in that, Including the photovoltaic module as described in claim 8.

Images