A photovoltaic module with a short creepage distance

Abstract

This utility model discloses a photovoltaic module with a small creepage distance, including a battery string layer. Glass layers are provided on both the top and bottom sides of the battery string layer, and an adhesive film layer is provided between the glass layers and the battery string layer. An insulating layer is provided around the outer edges of the battery string layer and the adhesive film layer. This utility model uses an insulating layer around the battery string layer for edge sealing, which not only helps reduce the creepage distance but also effectively prevents moisture, humidity, and rainwater from entering the photovoltaic module, preventing moisture corrosion of the internal cells and wiring, avoiding short circuits and corrosion problems, thereby extending the service life of the photovoltaic module. This utility model includes a battery string, a busbar, and at least one solder strip connecting the cells and the busbar. By bending the end of the solder strip towards the back of the photovoltaic module, the busbar portion is located on the back of the photovoltaic module, reserving space for increased cell size and facilitating increased photovoltaic module power.

Description

Technical Field

[0001] This utility model belongs to the field of photovoltaic module technology, specifically relating to a photovoltaic module with a small creepage distance. Background Technology

[0002] As competition in the photovoltaic module market intensifies, the requirements for modules are becoming increasingly stringent, demanding not only high power output but also high weather resistance and safety. Increasing cell size is a key area for improvement to enhance module power, and reducing creepage distance allows for greater flexibility in this regard.

[0003] However, reducing the creepage distance will reduce the safety performance of the solar cells. Therefore, a photovoltaic module with a small creepage distance can ensure the safety performance of the solar cells while reducing the creepage distance. Utility Model Content

[0004] The purpose of this invention is to provide a photovoltaic module with a short creepage distance to solve the problems mentioned in the background section. The photovoltaic module with a short creepage distance provided by this invention has the characteristic of ensuring the safety performance of the solar cells while reducing the creepage distance.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a photovoltaic module with a small creepage distance, comprising a battery string layer, glass layers on both the upper and lower sides of the battery string layer, an adhesive film layer between the glass layer and the battery string layer, and an insulating layer on the outer periphery of the battery string layer and the adhesive film layer.

[0006] In a further embodiment of this invention, the insulating layer is rectangular or elliptical.

[0007] Furthermore, in this invention, the thickness of the insulating layer is 0.5-2mm, and the width of one side of the insulating layer is 3-8mm.

[0008] In a further embodiment of this invention, the insulating layer is an organic polymer material or a composite modified material.

[0009] Furthermore, in this invention, the organic polymer material includes, but is not limited to, one of butyl rubber, silicone rubber, or polyisobutylene.

[0010] Furthermore, in this invention, the composite modified material includes, but is not limited to, one of butyl-silicone blend or nano-filled EVA tape.

[0011] To allow for increased cell size and facilitate higher photovoltaic module power, the cell string layer further includes several cell strings connected by busbars. Each cell string includes several cells connected by solder strips. The solder strips at one end of the cell string on the short side of the photovoltaic module have a bending structure, which bends the busbar at that end to the back of the short side of the photovoltaic module.

[0012] To prevent short circuits caused by direct contact between the battery string layer and the front solder strip and busbar, and to reduce the risk of microcracks in the battery cells during lamination, an insulating pad is further provided between the busbar and the battery string layer.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. This utility model sets an insulating layer around the battery string layer for sealing, which not only helps to reduce the creepage distance, but also effectively prevents moisture, humidity and rainwater from entering the photovoltaic module, preventing the battery cells and circuits inside the module from being corroded by moisture, avoiding problems such as short circuits and corrosion, thereby extending the service life of the photovoltaic module.

[0015] 2. This utility model bends the end of the welding strip toward the back of the photovoltaic module, so that the busbar part is located on the back of the photovoltaic module, which reserves space for increasing the size of the cell and facilitates the improvement of the photovoltaic module power.

[0016] 3. This utility model places the busbar on the back of the photovoltaic module, which can increase the width of the busbar to 5-12mm and reduce the thickness to 0.05-0.15mm. This not only increases the collection and transmission of current, but also reduces the risk of microcracks that may occur at the overlap of the cell and the busbar.

[0017] 4. The insulating material edge sealing technology of this utility model can be combined with the edge busbar bending technology. The insulating material edge sealing technology can reduce the creepage distance to a minimum of about 3.5mm. The edge busbar bending technology leaves a 1-3mm allowance on the weld strip from the cell to the edge busbar. Assuming that the initial distance between the edge of the module glass and the edge cell is 19mm, after combining the insulating material edge sealing technology to reduce the creepage distance and the edge busbar bending technology, a 12.5-16.5mm allowance can be left for changes in cell size. The entire module can reserve a distance of 25-33mm. Attached Figure Description

[0018] Figure 1 This is a partial cross-sectional view of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the battery string layer and the insulating layer of this utility model.

[0020] Figure 3 This is a schematic diagram of the battery string structure of this utility model.

[0021] Figure 4 This is a partial structural diagram of the present invention when the welding strip is led out from the front of the battery cell.

[0022] Figure 5 This is a partial structural diagram of the present invention when the welding strip is led out from the back of the battery cell.

[0023] In the diagram: 1. Battery string layer; 101. Battery string; 102. Battery cell; 2. Adhesive film layer; 3. Glass layer; 4. Insulating layer; 5. Solder strip; 6. Busbar; 7. Insulating pad. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Example 1

[0026] Please see Figures 1-5 The present invention provides the following technical solution: a photovoltaic module with a small creepage distance, including a battery string layer 1, glass layers 3 on both the upper and lower sides of the battery string layer 1, an adhesive film layer 2 between the glass layer 3 and the battery string layer 1, an insulating layer 4 on the outer periphery of the battery string layer 1 and the adhesive film layer 2, the insulating layer 4 being located inside the glass layer 3, the insulating layer 4 being rectangular, the insulating layer 4 having a thickness of 0.5 mm, the insulating layer 4 having a width of 3 mm on one side, and the insulating layer 4 being made of butyl rubber material.

[0027] By adopting the above technical solution, this utility model uses an insulating layer 4 to seal the perimeter of the battery string layer 1, replacing the traditional adhesive film layer. After lamination, the insulating layer 4 undergoes a morphological change, with its width increasing by 1.2-2 times both inward and outward. This morphological change of the insulating material will be concealed by the frame after the module is mounted, without affecting the appearance. Furthermore, the insulating material has poor fluidity, so its inward extension will not obstruct the battery cells. The laminated insulating layer has excellent adhesion to the glass layer 3. The creepage distance of conventional modules is 10-14mm. After sealing the perimeter with the insulating layer, the creepage distance can be reduced to a minimum of about 3.5mm, thus reserving a space of 6.5-10.5mm, which can be used to increase the size of the battery cells to improve efficiency. The insulating layer 4 generally has weak adhesion to the backsheet; therefore, sealing with the insulating layer is suitable for double-glass photovoltaic modules.

[0028] This invention provides an insulating layer 4 around the battery string layer 1 for sealing, which not only helps to reduce creepage distance, but also effectively prevents moisture, humidity and rainwater from entering the photovoltaic module, preventing the battery cells and wiring inside the module from being corroded by moisture, avoiding short circuits and corrosion problems, thereby extending the service life of the photovoltaic module.

[0029] Example 2

[0030] The difference between this embodiment and embodiment 1 is that, specifically, the insulating layer 4 is elliptical, the thickness of the insulating layer 4 is 1mm, the width of one side of the insulating layer 4 is 5mm, and the insulating layer 4 is made of polyisobutylene material.

[0031] Example 3

[0032] The difference between this embodiment and embodiment 1 is that, specifically, the insulating layer 4 is rectangular or elliptical, the thickness of the insulating layer 4 is 2mm, the width of one side of the insulating layer 4 is 8mm, and the insulating layer 4 is a butyl-silicone blend material.

[0033] Example 4

[0034] The difference between this embodiment and embodiment 1 is that, specifically, the battery string layer 1 includes a plurality of battery strings 101, which are connected by busbars 6. Each battery string 101 includes a plurality of battery cells 102 connected by solder strips 5. The solder strip of the battery string 101 at one end of the short side of the photovoltaic module extends 1-3mm and then has a bending structure, so that the busbar 6 at that end is bent to the back side of the short side of the photovoltaic module.

[0035] By adopting the above technical solution, this utility model bends the end of the welding strip 5 towards the back of the photovoltaic module, so that the busbar 6 is located on the back of the photovoltaic module, reserving space for increasing the size of the cell 1 and facilitating the improvement of the photovoltaic module's power. This utility model places the busbar 6 on the back of the photovoltaic module, allowing the width of the busbar 6 to be increased to 5-12mm and the thickness to be reduced to 0.05-0.15mm (the width of a conventional busbar is about 4mm and the thickness is about 0.3mm). This not only increases current collection and transmission but also reduces the risk of microcracks that may occur at the overlap between the cell and the busbar.

[0036] After bending the end of the solder strip 5 towards the back of the photovoltaic module, so that the busbar 6 is located on the back of the photovoltaic module, assuming the distance between the edge of the module glass layer and the edge cell is 19mm, if it is a conventional edge busbar with a width of about 4mm, the initial creepage distance is between 11-13mm. However, this invention can reserve a distance of 3-7mm, and the entire module can reserve a distance of 6-14mm. In order to buffer the stress caused by the bending of the solder strip and the folding of the cell, which may lead to microcracks in the cell, and without affecting its current collection effect, this invention expands the width of the busbar to 5-12mm. The reserved distance for the entire module can be used to increase the size of the cell and improve the overall power of the module.

[0037] Specifically, an insulating pad 7 is provided between the busbar 6 and the battery string layer 1. The insulating pad 7 has a three-layer structure. One layer is a PET layer with a coating that is resistant to yellowing, UV rays and water. The other layer is an EVA layer. The side of the insulating pad 7 extends beyond the edges of the busbar 6 and the battery string layer 1.

[0038] By adopting the above technical solution, short circuits can be prevented from being caused by direct contact between the battery string layer 1 and the front solder strip 5 and the bus bar 6. At the same time, the risk of microcracks in the battery cells during lamination can also be reduced.

[0039] In summary, this invention provides an insulating layer 4 around the perimeter of the battery string layer 1 for sealing. This not only helps reduce creepage distance but also effectively prevents moisture, humidity, and rainwater from entering the photovoltaic module, preventing moisture corrosion of the internal cells and wiring, thus avoiding short circuits and corrosion, and extending the lifespan of the photovoltaic module. By bending the end of the welding strip 5 towards the back of the photovoltaic module, this invention positions the busbar 6 on the back of the module, allowing for increased size of the battery string layer 1 and facilitating higher photovoltaic module power output. Positioning the busbar 6 on the back of the photovoltaic module allows for increased width (5-12mm) and reduced thickness (0.05-0.15mm), which not only increases current collection and transmission but also reduces the risk of microcracks at the overlap of the cells and busbar.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A photovoltaic module with a short creepage distance, characterized in that: It includes a battery string layer, with glass layers on both the top and bottom sides of the battery string layer, an adhesive film layer between the glass layer and the battery string layer, and an insulating layer around the battery string layer and the adhesive film layer.

2. A photovoltaic module with a short creepage distance according to claim 1, characterized in that: The insulating layer is rectangular or elliptical.

3. A photovoltaic module with a short creepage distance according to claim 1, characterized in that: The thickness of the insulating layer is 0.5-2mm, and the width of one side of the insulating layer is 3-8mm.

4. A photovoltaic module with a short creepage distance according to claim 1, characterized in that: The insulating layer is an organic polymer material or a composite modified material.

5. A photovoltaic module with a small creepage distance according to claim 4, characterized in that: The organic polymer material includes, but is not limited to, one of butyl rubber, silicone rubber, or polyisobutylene.

6. A photovoltaic module with a short creepage distance according to claim 4, characterized in that: The composite modified material includes, but is not limited to, one of butyl-silicone blend or nano-filled EVA tape.

7. A photovoltaic module with a short creepage distance according to claim 1, characterized in that: The battery string layer includes several battery strings, which are connected by busbars. Each battery string includes several cells connected by solder strips. The solder strip at one end of the battery string on the short side of the photovoltaic module has a bending structure, so that the busbar at that end is bent to the back side of the short side of the photovoltaic module.

8. A photovoltaic module with a short creepage distance according to claim 7, characterized in that: An insulating pad is provided between the busbar and the battery string layer.

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