Photovoltaic module capable of identifying abnormality of battery piece

Abstract

The invention discloses a photovoltaic module capable of identifying abnormity of a battery piece, which comprises a front light-transmitting packaging part, a battery string and a back packaging part which are packaged into a whole, and is characterized in that the front light-transmitting packaging part comprises an abnormity identification film layer; wherein in a normal working temperature range, the abnormity identification film layer is transparent, and when the temperature rises to an abnormal working temperature due to the fact that abnormal battery pieces appear in the battery string, at least part of the abnormity identification film layer area packaged corresponding to the abnormal battery pieces is in a non-transparent shape with the appearance capable of being identified. And rapid identification of the abnormal battery piece is realized.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaic modules, and in particular relates to a photovoltaic module capable of identifying abnormalities of solar cells. Background Art

[0002] As we all know, the main layer structure of a photovoltaic module is a battery string composed of several electrically connected cells, and then the battery string is laminated and packaged to obtain a photovoltaic module. Generally speaking, the electrical characteristics of the cells used in a photovoltaic module must be basically consistent, otherwise it will lead to poor electrical performance of the module or abnormal cells that are blocked will cause a "hot spot effect".

[0003] Furthermore, in order to ensure that the electrical characteristics of the cells used in photovoltaic modules are within the expected target range, the cells are sorted and tested during the manufacturing process. However, in the actual manufacturing process, it is found that there are various reasons for the abnormality of the cells. For example, there are defects in the silicon material used in the cell itself, or poor sintering during the manufacturing process of the cell, and cold soldering during the manufacturing of the battery string. There may be problems that have not been exposed during the cell sorting test. After being made into photovoltaic modules and used for a long time, they gradually change and cause abnormal cells to be present in parts of the module, which in turn leads to an increase in the leakage current of the module, and the accompanying problem of rising module temperature, which ultimately leads to the "hot spot effect" and burning problems in the module.

[0004] Although it is possible to detect the "hot spot effect" of a module in the laboratory by testing the output characteristic curve of the module and infrared imaging, for actual applications, it is impossible to visually detect whether there are abnormal cells during outdoor installation and subsequent use of photovoltaic modules. This is not observed until the abnormal problem causes the module to burn, which obviously affects the electrical performance and service life of the photovoltaic module.

[0005] Therefore, the applicant hopes to seek technical solutions to solve the above technical problems. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a photovoltaic module that can identify abnormalities in battery cells. By setting an abnormal identification film layer, when the photovoltaic module is in a normal operating temperature range, the abnormal identification film layer is transparent, and when an abnormal battery cell appears in the battery string, at least part of the abnormal identification film layer area corresponding to the package of the abnormal battery cell will be non-transparent and identifiable by appearance. The abnormal battery cell can be quickly identified by observing the change in the appearance state.

[0007] The technical solution adopted by the present invention is as follows: A photovoltaic module capable of identifying abnormal cells, comprising a front light-transmitting packaging portion, a cell string and a back light-transmitting packaging portion which are packaged as one body, wherein the front light-transmitting packaging portion comprises an abnormality identification film layer; wherein, within the normal operating temperature range, the abnormality identification film layer is transparent; when an abnormal cell appears in the cell string causing the temperature to rise to an abnormal operating temperature, at least part of the abnormality identification film layer area corresponding to the abnormal cell package is non-transparent and can be identified from the outside, thereby enabling rapid identification of the abnormal cell.

[0008] Preferably, the transparency means that the transmittance of the abnormality identification film layer is not less than 60%, more preferably not less than 70%, and further preferably not less than 80%. The transmittance is determined by testing the transmittance of a designated area of ​​the photovoltaic module within the wavelength range of 380-1100nm according to the test standard GB / T 2410-2008.

[0009] Preferably, the non-transparent state means that the transmittance of at least part of the abnormal identification film layer area corresponding to the package of the abnormal battery cell is less than 50%, more preferably less than 40%, and the transmittance is tested on the designated area of ​​the photovoltaic module within the wavelength range of 380-1100nm according to the test standard GB / T 2410-2008.

[0010] Preferably, the normal operating temperature range means that the surface temperature of the photovoltaic module is not higher than 70°C, and more preferably not higher than 60°C; the surface temperature is obtained by testing the light-receiving surface of the photovoltaic module using an infrared thermal imager according to the test standard GB / T38883-2020.

[0011] Preferably, the abnormal operating temperature is a surface temperature of the photovoltaic module greater than 90°C, more preferably greater than 100°C, and less than the melting temperature of the abnormal identification film layer; the surface temperature is obtained by testing the light-receiving surface of the photovoltaic module using an infrared thermal imager according to the test standard GB / T 38883-2020.

[0012] Preferably, the abnormality identification film layer will undergo recrystallization at an abnormal working temperature, causing its light transmittance to decrease, resulting in its appearance being non-transparent and recognizable by appearance.

[0013] Preferably, the abnormality identification film layer is made of thermoplastic polymer material, preferably polyethylene or modified polyethylene material.

[0014] Preferably, when an abnormal battery cell appears in the battery string and causes the temperature to rise to an abnormal operating temperature, at least a portion of the abnormal identification film layer area of ​​the package corresponding to the abnormal battery cell appears white and can be identified by the naked eye.

[0015] Preferably, at abnormal working temperature, the crystallinity of the abnormality identification film layer is 30-90%, more preferably 40-85%.

[0016] Preferably, when a non-transparent area that can be identified from the outside is observed in a photovoltaic module, this situation is used as a maintenance reminder to facilitate maintenance and replacement of the corresponding area of ​​the photovoltaic module, thereby avoiding the problem of electrical performance degradation or burning of the photovoltaic module due to abnormal cell cells.

[0017] The present application provides an abnormality identification film layer in the front light-transmitting packaging part of the photovoltaic module (that is, the light-receiving surface packaging structure of the battery string). When the photovoltaic module is in the normal operating temperature range, the abnormality identification film layer is transparent. When an abnormal battery cell appears in the battery string, the leakage current will increase and quickly cause the temperature to rise to an abnormal operating temperature. At least part of the abnormality identification film layer area corresponding to the abnormal battery cell will be non-transparent and recognizable from the outside. As time accumulates, the non-transparent area will become larger and larger. By observing the change in the appearance state, the abnormal battery cell can be quickly identified. In actual applications, this situation can be used as a maintenance reminder information, which can facilitate the maintenance and replacement of the corresponding area of ​​the photovoltaic module, thereby avoiding the problem of electrical performance degradation or burning of the photovoltaic module due to abnormal battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a partial photograph of a photovoltaic module in a normal operating temperature range under a specific implementation mode of the present application; Figure 2 It is an infrared thermal image of the temperature test of the photovoltaic module in the normal working temperature range using an infrared thermal imager; Figure 3 It is a partial photograph of a photovoltaic module at an abnormal normal operating temperature under a specific implementation mode of the present application; Figure 4 It is an infrared thermal imaging image obtained by using an infrared thermal imager to test the temperature of photovoltaic modules at abnormal operating temperatures. DETAILED DESCRIPTION

[0019] The embodiment of the present invention discloses a photovoltaic module capable of identifying abnormality of a cell, comprising a front light-transmitting encapsulation part, a cell string and a back light-transmitting encapsulation part which are encapsulated as one, wherein the front light-transmitting encapsulation part comprises an abnormality-identifying film layer; wherein, see Figure 1 and Figure 2 As shown, when in the normal operating temperature range, the abnormal identification film is transparent, see Figure 3 and Figure 4As shown, when an abnormal battery cell appears in the battery string and causes the temperature to rise to an abnormal working temperature, at least part of the abnormal identification film layer area of ​​the package corresponding to the abnormal battery cell becomes non-transparent and can be identified from the outside, thereby realizing rapid identification of the abnormal battery cell; preferably, in this embodiment, when patrolling staff or drones or cameras observe that there are non-transparent areas in the photovoltaic module that can be identified from the outside, this situation is used as maintenance reminder information, which can facilitate maintenance and replacement of the corresponding areas of the photovoltaic module, thereby avoiding the problem of electrical performance degradation of the photovoltaic module due to abnormal batteries or burning of the photovoltaic module.

[0020] The abnormal cells involved in this embodiment include abnormal cells such as a mixture of light and dark cells or poorly sintered cells in a photovoltaic module, and cell shielding or hidden cracking in the photovoltaic module during outdoor application, which in turn causes excessive current in the area of ​​the abnormal cells and leads to heating in local areas of the module. The present application utilizes the change in temperature of the photovoltaic module caused by the heat to configure an abnormal identification film layer that can produce a corresponding change in transmittance, and uses the change in transmittance to quickly identify whether there is an abnormal cell problem.

[0021] Preferably, in this embodiment, the front light-transmitting packaging part includes a transparent front panel, an abnormality identification film layer and a front packaging film layer (optional), wherein the transparent front panel can adopt any known transparent front panel, such as transparent glass or a flexible lightweight front panel; the front packaging film layer can adopt any known front film; the battery string can adopt any known battery string; the back packaging part includes a back packaging film layer (optional) and a photovoltaic back panel, wherein the back packaging film layer can adopt any known back film, and the photovoltaic back panel can adopt any known photovoltaic back panel structure.

[0022] Preferably, in this embodiment, transparent means that the transmittance of the abnormal identification film layer is not less than 60%, more preferably not less than 70%, and further preferably not less than 80%; non-transparent means that the transmittance of at least part of the abnormal identification film layer area corresponding to the package of the abnormal battery cell is less than 50%, more preferably less than 40%; wherein, the transmittance involved in the full text of this application is a transmittance test of a designated area of ​​a photovoltaic module within the wavelength range of 380-1100nm based on the test standard GB / T 2410-2008.

[0023] Preferably, in this embodiment, the normal operating temperature range refers to the surface temperature of the photovoltaic module not higher than 70°C, more preferably not higher than 60°C, and more preferably, the normal operating temperature range is generally 20-50°C; the abnormal operating temperature is the surface temperature of the photovoltaic module greater than 90°C, more preferably greater than 100°C, and less than the melting temperature of the abnormal identification film layer (when the melting temperature of the abnormal identification film layer is reached, the appearance will also remain transparent); the surface temperature involved in the full text of this application is obtained by testing the light-receiving surface of the photovoltaic module with an infrared thermal imager according to the test standard GB / T 38883-2020.

[0024] Preferably, in this embodiment, the abnormal identification film layer will undergo recrystallization at an abnormal working temperature, causing its light transmittance to decrease, resulting in its appearance being non-transparent and recognizable by appearance, wherein the higher the degree of recrystallization, the lower the light transmittance; further preferably, in this embodiment, the abnormal identification film layer is made of thermoplastic polymer material, preferably polyethylene PE or modified polyethylene PE material; when an abnormal battery cell appears in the battery string and causes the temperature to rise to an abnormal working temperature, at least part of the abnormal identification film layer area corresponding to the package of the abnormal battery cell appears white and recognizable to the naked eye; Further preferably, in this embodiment, at abnormal operating temperature, the abnormal identification film layer has a crystallinity of 30-90%, more preferably 40-85%. Specifically, when the abnormal identification film layer is recrystallized, scattering will occur at the interface between its crystalline region and amorphous region, thereby causing a change in transmittance. The higher the crystallinity, the lower the transmittance.

[0025] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0026] Embodiment 1: A photovoltaic module capable of identifying abnormal cells, comprising an integrated front encapsulation glass, a modified PE film (as an abnormal identification film layer, the material model is the PETB series provided by Ningbo Fuzhi New Materials Co., Ltd., with a crystallization temperature of 125-135°C and a thickness of 200 microns), an EVA film, a crystalline silicon cell string, an EVA film and a photovoltaic backplane; wherein the modified PE film is transparent in a normal operating temperature range (usually 20-50°C); when a milky white local area is found, it means that an abnormal cell has occurred in the area, and upon detection, the corresponding surface temperature is 130°C (i.e., an abnormal normal operating temperature), and the crystallinity of the modified PE film is 80-85%; this situation is used as a maintenance reminder message, and the corresponding area of ​​the photovoltaic module is maintained and replaced to avoid the problem of electrical performance degradation or burning of the photovoltaic module due to abnormal cells.

[0027] Embodiment 2: A photovoltaic module capable of identifying abnormal cells, comprising a front flexible transparent front plate, a modified PE film (as an abnormal identification film layer, the material model is the PETB series provided by Ningbo Fuzhi New Materials Co., Ltd., with a crystallization temperature of 110-121°C and a thickness of 200 microns), an EVA film, a crystalline silicon cell string, an EVA film and a photovoltaic backplane; wherein the modified PE film is transparent within the normal operating temperature range (20-50°C); when a milky white local area is found, it means that an abnormal cell has occurred in the area, and upon detection, the corresponding surface temperature is 115°C (i.e., an abnormal operating temperature), and the crystallinity of the modified PE film is 45-55%; this situation is used as a maintenance reminder to perform maintenance and replacement on the corresponding area of ​​the photovoltaic module to avoid the problem of electrical performance degradation or burning of the photovoltaic module due to abnormal cells.

[0028] Embodiment 3: A photovoltaic module capable of identifying abnormal cells, comprising a front flexible transparent front plate, a modified PE film (as an abnormal identification film layer, the material model is the PETB series provided by Ningbo Fuzhi New Materials Co., Ltd., with a crystallization temperature of 115-123°C and a thickness of 200 microns), an EVA film, a crystalline silicon cell string, an EVA film and a photovoltaic backplane; wherein the modified PE film is transparent within the normal operating temperature range (20-50°C); when a milky white local area is found, it means that an abnormal cell has occurred in the area, and upon detection, the corresponding surface temperature is 119°C (i.e., an abnormal operating temperature), and the crystallinity of the modified PE film is 60-70%; this situation is used as a maintenance reminder to perform maintenance and replacement on the corresponding area of ​​the photovoltaic module to avoid the problem of electrical performance degradation or burning of the photovoltaic module due to abnormal cells.

[0029] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0030] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A photovoltaic module capable of identifying abnormality of a cell, comprising a front light-transmitting encapsulation part, a cell string and a back encapsulation part encapsulated as one, characterized in that: The front light-transmitting packaging portion includes an abnormal identification film layer; wherein, when in the normal operating temperature range, the abnormal identification film layer is transparent, and when an abnormal battery cell appears in the battery string, causing the temperature to rise to an abnormal operating temperature, at least part of the abnormal identification film layer area corresponding to the package of the abnormal battery cell becomes non-transparent and can be identified from the outside, thereby realizing rapid identification of the abnormal battery cell.

2. The photovoltaic module capable of identifying abnormality of a cell according to claim 1, characterized in that: The transparency means that the transmittance of the abnormality identification film layer is not less than 60%, more preferably not less than 70%, and further preferably not less than 80%. The transmittance is tested on a designated area of ​​the photovoltaic module within a wavelength range of 380-1100nm according to the test standard GB / T 2410-2008.

3. The photovoltaic module capable of identifying abnormality of a cell according to claim 1, characterized in that: The non-transparent state means that the transmittance of at least part of the abnormal identification film layer area corresponding to the package of the abnormal battery cell is less than 50%, more preferably less than 40%. The transmittance is tested on the designated area of ​​the photovoltaic module within the wavelength range of 380-1100nm based on the test standard GB / T 2410-2008.

4. The photovoltaic module capable of identifying abnormality of a cell according to claim 1, characterized in that: The normal operating temperature range means that the surface temperature of the photovoltaic module is not higher than 70°C, and more preferably not higher than 60°C; the surface temperature is obtained by testing the light-receiving surface of the photovoltaic module using an infrared thermal imager according to the test standard GB / T 38883-2020.

5. The photovoltaic module capable of identifying abnormality of a cell according to claim 1, characterized in that: The abnormal operating temperature refers to the surface temperature of the photovoltaic module being greater than 90°C, more preferably greater than 100°C, and less than the melting temperature of the abnormal identification film layer; the surface temperature is obtained by testing the light-receiving surface of the photovoltaic module with an infrared thermal imager according to the test standard GB / T38883-2020.

6. The photovoltaic module capable of identifying abnormality of a cell according to claim 1, characterized in that: The abnormal identification film layer will recrystallize at an abnormally normal operating temperature, causing its light transmittance to decrease, resulting in its appearance being non-transparent and recognizable from the outside.

7. The photovoltaic module capable of identifying abnormality of a cell according to claim 1 or 6, characterized in that: The abnormality identification film layer is made of thermoplastic polymer material, preferably polyethylene or modified polyethylene material.

8. The photovoltaic module capable of identifying abnormality of a cell according to claim 7, characterized in that: When an abnormal battery cell appears in the battery string and causes the temperature to rise to an abnormal operating temperature, at least a portion of the abnormal identification film layer area of ​​the package corresponding to the abnormal battery cell appears white and can be identified by the naked eye.

9. The photovoltaic module capable of identifying abnormality of a cell according to claim 6, characterized in that: At abnormal working temperature, the crystallinity of the abnormality identification film layer is 30-90%, and more preferably 40-85%.

10. The photovoltaic module capable of identifying abnormality of a cell according to claim 1, characterized in that: When a photovoltaic module is observed to have an outwardly identifiable non-transparent area, this situation is used as a maintenance reminder to facilitate maintenance and replacement of the corresponding area of ​​the photovoltaic module, thereby avoiding the problem of electrical performance degradation or photovoltaic module burning due to abnormal battery cells.

Images