Method for evaluating relative attenuation rate of photovoltaic module

Abstract

The invention belongs to the field of solar cells. The embodiment of the invention provides a method for evaluating the relative attenuation rate of a photovoltaic module. The method comprises the steps that the electrical performance attenuation rate of a first battery piece before and after corrosion is obtained; obtaining the electrical performance attenuation rate of the photovoltaic module formed by manufacturing the second battery piece; calculating the unit attenuation rate Pcell i of the first battery piece under corrosion at different times and the unit attenuation rate Pmodule m of the photovoltaic module; a simulation formula of the Pmodule and a simulation formula of the Pcell are obtained; the method comprises the following steps: testing a third battery piece to obtain the electrical performance attenuation rate of the third battery piece, calculating to obtain the unit attenuation rate Pcell of the electrical performance, and simulating the attenuation rate Pmodule after the third battery piece is prepared into a photovoltaic module by using a simulation formula. According to the method, the relative attenuation rate of the battery when the battery is used for the assembly can be rapidly evaluated at the battery end. And evaluating whether the preparation process or material of the battery is qualified or not according to the attenuation rate.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a method for evaluating the relative attenuation rate of a photovoltaic module. Background Art

[0002] PV module reliability refers to the ability of a PV module to continuously and stably output electrical energy under specific operating conditions. It is the foundation for the long-term stable operation of a PV power generation system. With the rapid development of the PV industry, the reliability of PV modules has become increasingly prominent, directly impacting the economic and environmental benefits of PV power generation systems. Improving PV module reliability is key to promoting the sustainable development of the PV industry and is of great significance for reducing the cost of PV power generation and improving its market competitiveness.

[0003] During their application, photovoltaic modules face various harsh environmental conditions, such as high temperature, high humidity, and long-term moisture penetration. We simulate the attenuation of modules under these harsh environmental conditions through wet heat tests, and feed the results back to the battery end to improve the performance of the battery end, thereby enhancing the reliability and durability of the modules.

[0004] Traditionally, moisture and heat resistance is tested by preparing solar cells into photovoltaic modules and then testing the photovoltaic modules. However, the testing time is relatively long (1000 hours to 3000 hours), which is not conducive to optimizing and improving the process at the battery end. In other words, the timeliness of optimizing the battery end performance is poor.

[0005] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the Invention

[0006] The embodiments of the present application provide a method for evaluating the relative attenuation rate of a photovoltaic module to solve or alleviate the above-mentioned technical problem of poor timeliness of optimizing and improving the process at the battery end.

[0007] The present application provides a method for evaluating the relative attenuation rate of a photovoltaic module, comprising: (1) Test the first electrical performance of the first cell, denoted as P 1处理前 , and corrode the first battery cell, and then perform different t i The second electrical performance test under time is recorded as P 1i处理后 , to obtain the electrical performance attenuation rate △P before and after the corrosion of the first cell 1i =(P 1i处理后 -P 1处理前 ) / P 1处理前 , i is a positive number; (2) A photovoltaic module is made by using a second cell that is the same as the first cell in step (1), and the photovoltaic module is tested for a third electrical performance, which is recorded as P 2处理前 , and then subject the photovoltaic module to a second wet heat treatment, and then m The fourth electrical performance test of the photovoltaic module subjected to the wet heat treatment under the time is recorded as P 2m处理后 , to obtain the electrical performance attenuation rate ΔP of the photovoltaic module before and after the second wet heat treatment 2m =(P 2m处理后 -P 2处理前 ) / P 2处理前 , m is a positive number; (3) Calculate the unit attenuation rate P of the first cell under different corrosion time cell i =△P 1i / t i , and the unit attenuation rate P of the photovoltaic module module m= △P 2m / t m ; (4) For P in step (3) module m and P cell i The data were fitted to obtain P module and P cell The simulation formula of (5) Perform the test of step (1) on the third cell to obtain the electrical performance attenuation rate of the third cell, and calculate the unit attenuation rate P of the electrical performance. cell , and then use the simulation formula in step (4) to evaluate the attenuation rate P of the third cell after it is prepared into a photovoltaic module module .

[0008] The method of the present application can quickly evaluate the attenuation rate of the battery when it is used in the assembly at the battery end, and then evaluate whether the manufacturing process or materials of the battery are qualified based on the attenuation rate.

[0009] According to an embodiment of the present application, in step (1), the corrosion is salt spray corrosion, and the spraying time of the salt spray corrosion process is 3S~10S; The mass percentage of sodium chloride in the salt mist is 1% to 8%.

[0010] According to an embodiment of the present application, the first cell after corrosion is subjected to different t i The test of the second electrical performance under the time includes the second photoelectric performance of the first cell after corrosion tested under the first wet heat treatment conditions, t i 1h~8h; The first wet heat treatment includes a temperature of 60° C. to 90° C. and a humidity of 60% to 95%.

[0011] According to an embodiment of the present application, in step (2), the third electrical property and the fourth electrical property each independently include photoelectric efficiency, t m 500h~4000h.

[0012] According to an embodiment of the present application, in step (2), the second wet heat treatment includes a temperature of 60°C to 90°C and a humidity of 60% to 95%.

[0013] According to an embodiment of the present application, in step (4), the simulation formula is obtained by mathematical modeling.

[0014] According to an embodiment of the present application, in step (5), the third battery cell is a battery cell based on the same battery type as the first battery cell, but obtained using different processes and / or process conditions.

[0015] According to an embodiment of the present application, in step (5), the attenuation rate P of the third cell after being prepared into a photovoltaic module is simulated. module n include: According to the simulation formula, the attenuation rate P of the third cell after being prepared into a photovoltaic module is obtained. module , and according to P module If the attenuation rate is not greater than the standard attenuation rate, the attenuation rate of the third cell when used to prepare a photovoltaic module is evaluated as qualified; Otherwise, the attenuation rate of the third solar cell when used to prepare a photovoltaic module is evaluated as unqualified.

[0016] According to an embodiment of the present application, the first cell is a stack of one or both of a crystalline silicon cell and a perovskite cell.

[0017] According to an embodiment of the present application, the crystalline silicon cell includes an emitter and back passivation cell, a tunneling oxide passivation contact solar cell, a TOPCon stacked back electrode contact cell, a heterojunction cell or a back contact heterojunction cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0019] Figure 1 1 is a schematic diagram of a process for evaluating the relative attenuation rate of a photovoltaic module provided in an embodiment of the present application; Figure 2 is a line diagram of the simulation formula of Example 1; Figure 3 This is the line diagram of the touch you formula of Example 2. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless there is a conflict.

[0021] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there can be no intervening elements or layers. It should be understood that while the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or portion from another. Thus, without departing from the teachings of the present application, a first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion. Furthermore, when a second element, component, region, layer, or portion is discussed, it does not necessarily indicate that the first element, component, region, layer, or portion is present in the present application.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, including the two endpoint integers of the numerical range, and each integer between the two endpoints, is equivalent to directly enumerating each integer. When multiple numerical ranges are provided to describe a feature or characteristic, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0024] The embodiment of the present application provides a method for evaluating the relative attenuation rate of a photovoltaic module. Figure 1 , including the following steps: S1: Test the first electrical performance of the first cell, denoted as P 1处理前 , and corrode the first battery cell, and then perform different t i The second electrical performance test under time is recorded as P 1i处理后 , to obtain the electrical performance attenuation rate ΔP of the first cell before and after the corrosion 1i =(P 1i处理后 -P 1处理前 ) / P 1处理前 , i is a positive number.

[0025] In this step, the electrical performance attenuation rate of the first cell before and after corrosion is obtained by testing the first electrical performance and the second electrical performance of the first cell before and after salt spray corrosion.

[0026] In some embodiments, the salt spray corrosion test comprises the following steps: S100: Provide the first battery cell and pre-clean the front and back sides with pure water and blow dry with a nitrogen gun to remove any attachments that may exist on the battery surface and ensure that the battery surface is clean.

[0027] S200: Testing the first electrical performance of the first battery cell, denoted as P 1处理前 As some examples, the photovoltaic efficiency of the first cell is tested.

[0028] S300: Corrosion treatment of the first cell. Optionally, the corrosion is salt spray corrosion, the salt spray time during the salt spray corrosion process is 3s to 10s, and the mass percentage of sodium chloride in the salt spray is 1% to 8%.

[0029] S400: Dry the corroded product. Drying is done by standing it at room temperature for 15 to 60 minutes.

[0030] S500: The dried product is subjected to different t i Time for the second electrical performance test, t i The first wet heat treatment includes a temperature of 60°C to 90°C, for example, the temperature can be 60°C, 70°C, 80°C, 90°C, etc.; the humidity is 60%-95%, for example, 60%, 80%, 95%, etc. Therefore, the aging test is carried out under the set high temperature and high humidity conditions, wherein the temperature range is the high temperature environment that may be encountered in the subsequent photovoltaic module process and use, such as lamination temperature, hot spots causing local high temperature environment, etc., and the relative humidity range includes common humidity and high humidity environment on the water surface. The setting of this simulated wet heat environment is closer to reality, and the results obtained can better guide actual practice.

[0031] As some examples, the second electrical performance of the corroded first battery cell is tested. Every 1 hour to 8 hours, the battery is taken out for performance testing. For example, the second electrical performance at time t1 = 1 hour, t2 = 2 hours, t3 = 3 hours, t4 = 4 hours, t5 = 5 hours, t6 = 6 hours, etc. is recorded as P 11 、P 12 、P 13 、P 14 、P 15 、P 16 .

[0032] S600: Obtaining the electrical performance degradation rate ΔP of the first cell before and after corrosion 1i =(P 1i处理后 -P 1处理前 ) / P 1处理前 , i is a positive number.

[0033] S2: Use the second cell that is the same as the first cell in step (1) to make a photovoltaic module, and test the photovoltaic module for the third electrical performance, which is recorded as P 2处理前 , and then subject the photovoltaic module to a second wet heat treatment, and then m The fourth electrical performance test of the photovoltaic module subjected to the wet heat treatment under the time is recorded as P 2m处理后 , to obtain the electrical performance attenuation rate ΔP of the photovoltaic module before and after the second wet heat treatment 2m =(P 2m处理后 -P 2m处理前 ) / P 2m处理前 , m is a positive number.

[0034] In this step, a second cell identical to the first cell is used to make a photovoltaic module, and a third electrical performance test is performed on the second cell that has not undergone the second wet heat treatment. The photovoltaic module is then subjected to a second wet heat treatment, and a fourth electrical performance test is performed on the photovoltaic module at different second wet heat treatment times, thereby obtaining the electrical performance attenuation rate ΔP of the photovoltaic module before and after the second wet heat treatment. 2m =(P 2m处理后 -P 2m处理前 ) / P 2m处理前 .

[0035] In some embodiments, the second heat and humidity treatment comprises a temperature of 60° C. to 90° C. and a humidity of 60% to 95%.

[0036] In some embodiments, the third electrical performance and the fourth electrical performance independently include the photovoltaic efficiency of the first cell under damp heat test conditions, t m It is 500h~4000h, for example, 500h, 1000h, 2000h, 3000h, 4000h, etc.

[0037] In some embodiments, the first battery cell and the second battery cell being the same means that the first battery cell and the second battery cell are produced using the same materials and process conditions.

[0038] S3: Calculate the unit attenuation rate P of the first cell cell i =△P 1i / t i , and calculate the unit attenuation rate P of the photovoltaic module module m= △P 2m / t m In this step, the unit attenuation rate P of the first cell is calculated. cell i =△P 1i / t i , that is, multiple P cell Calculate the unit attenuation rate P of the photovoltaic module module m= △P 2m / t m , to obtain multiple P module Value S4: P in step S3 module m and P cell i The data were fitted to obtain P module and P cell The simulation formula In this step, by module m and P cel i The values ​​of are fitted to obtain the simulation formula.

[0039] In some embodiments, the simulation formula is derived through mathematical modeling. The equivalent mapping fitting method for attenuation characteristics uses mathematical modeling to perform function fitting based on the homology of the physical mechanisms of battery and component attenuation (e.g., material aging, electrochemical reactions, etc.) to derive the simulation formula.

[0040] S5: Test the third cell in step (1) to obtain the electrical performance attenuation rate of the third cell, and calculate the unit attenuation rate P of the electrical performance. cell , and then use the simulation formula in step (4) to evaluate the attenuation rate P of the third cell after it is prepared into a photovoltaic module module .

[0041] In some embodiments, the third cell is based on the same cell type but is manufactured using a different process and / or process conditions. Therefore, the third cell is selected to be of the same type as the first cell (e.g., both are tunnel oxide passivation contact solar cells or heterojunction solar cells). The first cell is manufactured using the same process technology, and the third cell differs from the first cell in that one or more steps in the manufacturing process use different process methods or materials (e.g., different diffusion processes, passivation processes, or slurries).

[0042] In some embodiments, the attenuation rate P of the third cell after being prepared into a photovoltaic module is evaluated. module include: According to the simulation formula, the attenuation rate P of the third cell after being prepared into a photovoltaic module is output. module , and according to P module If the attenuation rate is not greater than the standard attenuation rate, the attenuation rate of the third cell when used to prepare a photovoltaic module is evaluated as qualified; Otherwise, the attenuation rate of the third solar cell when used to prepare a photovoltaic module is evaluated as unqualified.

[0043] It is understandable that n can be a positive number.

[0044] The term standard attenuation rate can be: the company's standard 2000-hour attenuation for PV modules subjected to damp heat is <4%.

[0045] In some embodiments, the first, second, third, and fourth electrical properties described above may each include maximum output power, i.e., the maximum output power of the cell measured using an FCT650 instrument under standard electrical performance test conditions. Compared to contact resistance, which only reflects the corrosion status of the cell's metal gridline area, maximum output power, as a comprehensive parameter, can more comprehensively reflect the cell's corrosion resistance.

[0046] In some embodiments, the first, second, and third cells may be crystalline silicon cells, perovskite cells, or a stack of one or both. Thus, the cell-side method for assessing the degradation rate of a photovoltaic module has a wide range of applications. Furthermore, the crystalline silicon cells include, but are not limited to, emitter and back passivated cells (PERC cells), tunneling oxide passivated contact solar cells (TOPCon cells), TOPCon-stacked back contact solar cells (TBC cells), heterojunction cells (HJT cells), or back contact heterojunction cells (HBC cells).

[0047] The method of the present application can quickly evaluate the attenuation rate of the battery when it is used in the assembly at the battery end, and then evaluate whether the manufacturing process or materials of the battery are qualified based on the attenuation rate.

[0048] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0049] Example 1: Take TOPCon battery as an example: Select 10 cells (first cell), clean them with pure water and blow dry them, test the electrical performance, and record the average power of 10 cells as P 1处理前 , The 10 cells (the first cell) were sprayed with a sodium chloride solution, ensuring that both the front and back sides of the cells were evenly and completely sprayed. The mass fraction of sodium chloride was 4%. The 10 cells were then placed in a test chamber at a temperature of 85°C and a humidity of 85%. The cells were removed from the test chamber after 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, and 8 hours of treatment, and the second electrical performance (power) was measured, recorded as P. 1i After treatment, a total of 15 times were taken out, and the electrical performance (power) attenuation rate △P corresponding to treatment time of 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, and 8h was calculated. 1i =(P 1i处理后 -P 1处理前 ) / P 1处理前 , and record it in the table.

[0050] Use the second cell that is the same as the first cell to make 2pcs of finished photovoltaic modules, and first test the third electrical performance P 2处理前, and then treated in a test box with a temperature of 85°C and a humidity of 85%. After 500h, 750h, 1000h, 1250h, 1500h, 1750h, 2000h, 2250h, 2500h, 2750h, 3000h, 3250h, 3500h, 3750h, and 4000h, the fourth electrical performance was taken out and tested, and recorded as P 2m处理后 Calculate the component power attenuation △P corresponding to the processing time of 500h, 750h, 1000h, 1250h, 1500h, 1750h, 2000h, 2250h, 2500h, 2750h, 3000h, 3250h, 3500h, 3750h, and 4000h. 2m =(P 2m处理后 -P 2处理前 ) / P 2处理前 , and recorded in Table 1.

[0051] Calculate the battery unit decay rate P corresponding to each time cell i (P cell i =△P 1i / t i ) and the component unit attenuation rate P module m (P module m =△P 2m / t m ), all data are shown in Table 1.

[0052] For the data in Table 1, the battery / module unit attenuation rate P cell i and P module m Perform fitting ( Figure 2 ), using mathematical modeling, we can get P cell i and P module m Simulation formula: Y=0.306830×X 2 +0.006628×X+0.000015, where X is P cell , Y is P module .

[0053] Take the third cell, which is a new batch of cells produced on the production line. Only the diffusion process has been improved. It is necessary to confirm the heat and humidity performance of the third cell when it is prepared into a photovoltaic module. Take 10 pieces of this batch of cells (the third cell) and treat them with a 4% sodium chloride solution. Then treat them in a test chamber at a temperature of 85°C and a humidity of 85% for 4 hours. The average battery power attenuation rate P is obtained. cell 4 =-2.4%, calculate the battery unit attenuation rate P cell =-2.4% / 4=-0.6%, then calculate the unit attenuation rate of the component according to the simulation formula: P module =-0.00137%.

[0054] According to our company's module damp heat standard, attenuation is less than 4% after 2000 hours. Based on the unit attenuation rate calculated in the simulation above, the simulated module attenuation power = -0.00137% * 2000 = -2.74%, which meets the standard. Therefore, this method can be used to quickly simulate module attenuation at the cell end.

[0055] Table 1

[0056] Example 2: Take HJT battery as an example: Select 10 cells (first cell), clean them with pure water and blow dry them, test the electrical performance, and record the average power of 10 cells as P 1处理前 , The 10 cells (the first cell) were sprayed with a sodium chloride solution, ensuring that both the front and back sides of the cells were evenly and completely sprayed. The mass fraction of sodium chloride was 4%. The 10 cells were then placed in a test chamber at a temperature of 85°C and a humidity of 85%. The cells were removed from the test chamber after 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, and 8 hours of treatment, and the second electrical performance (power) was measured, recorded as P. 1i处理后 , a total of 15 times, calculate the electrical performance (power) attenuation rate △P corresponding to 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, and 8h 1i =(P 1i处理后 -P 1处理前 ) / P 1处理前 , and record it in the table.

[0057] Use the second cell that is the same as the first cell to make 2pcs of finished photovoltaic modules, and first test the third electrical performance P 2处理前 , and then treated in a test box with a temperature of 85°C and a humidity of 85%. After 500h, 750h, 1000h, 1250h, 1500h, 1750h, 2000h, 2250h, 2500h, 2750h, 3000h, 3250h, 3500h, 3750h, and 4000h, the fourth electrical performance was taken out and tested, and recorded as P 2m处理后Calculate the component power attenuation △P corresponding to the processing time of 500h, 750h, 1000h, 1250h, 1500h, 1750h, 2000h, 2250h, 2500h, 2750h, 3000h, 3250h, 3500h, 3750h, and 4000h. 2m =(P 2m处理后 -P 2处理前 ) / P 2处理前 , and record it in the table.

[0058] Calculate the battery unit decay rate P corresponding to each time cell i (P cell i =△P 1i / t i ) and the component unit attenuation rate P module m (P module m =△P 2m / t m ), all data are shown in Table 2.

[0059] For the data in Table 2, the battery / module unit attenuation rate P cell i and P module m Perform fitting ( Figure 3 ), using mathematical modeling, we can get P cell i and P module m Simulation formula: Y=-0.854028×X 2 -0.016376×X-0.0001, where X is P cell , Y is P module .

[0060] The third battery cell is a new batch of battery cells produced by the production line. The screen process has been improved, and its component heat and humidity performance needs to be confirmed. Take 10 pieces of this batch of battery cells, use 4% sodium chloride solution to treat them, and then treat them in a test chamber at a temperature of 85℃ and a humidity of 85% for 5 hours. The average battery power attenuation rate is -6.0%, and the battery unit attenuation rate P is calculated. cell =-6.0% / 5=-1.2%, then calculate the unit attenuation rate of the component according to the simulation formula: P module =-0.00265%.

[0061] According to the company's module damp heat standard, the 2000-hour attenuation is <4.5%. Based on the above-calculated unit attenuation rate, the module simulated attenuation power = -0.00265%*2000 = -5.30%. This exceeds the standard, and the attenuation rate of the third battery cell when used to prepare a photovoltaic module is evaluated as unqualified.

[0062] Table 2

[0063] It should also be noted that references to "some embodiments," "other embodiments," "embodiments," etc., in this application refer to specific features, structures, or characteristics described in conjunction with such embodiments as are included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that the realization of such feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0064] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] It should also be noted that the above are only preferred embodiments of the present application and do not limit the scope of patent protection of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of the present application.

Claims

1. A method for evaluating the relative attenuation rate of a photovoltaic module, characterized in that: include: (1) Test the first electrical performance of the first cell, denoted as P 1处理前 , and corrode the first battery cell, and then perform different t i The second electrical performance test under time is recorded as P 1i处理后 , to obtain the electrical performance attenuation rate △P before and after the corrosion of the first cell 1i =(P 1i处理后 -P 1处理前 ) / P 1处理前 , i is a positive number; (2) A second cell identical to the first cell in step (1) is used to make a photovoltaic module, and a third electrical performance test is performed on the photovoltaic module, which is recorded as P 2处理前 , and then subject the photovoltaic module to a second wet heat treatment, and then m The fourth electrical performance test of the photovoltaic module subjected to the wet heat treatment under the time is recorded as P 2m处理后 , to obtain the electrical performance attenuation rate ΔP of the photovoltaic module before and after the second wet heat treatment 2m =(P 2m处理后 -P 2处理前 ) / P 2处理前 , m is a positive number; (3) Calculate the unit attenuation rate P of the first cell under different corrosion time cell i =△P 1i / t i , and the unit attenuation rate P of the photovoltaic module module m= △P 2m / t m ; (4) For P in step (3) module m and P cell i The data were fitted to obtain P module and P cell The simulation formula of (5) Perform the test of step (1) on the third cell to obtain the electrical performance attenuation rate of the third cell, and calculate the unit attenuation rate P of the electrical performance. cell , and then use the simulation formula in step (4) to evaluate the attenuation rate P of the third cell after it is prepared into a photovoltaic module module .

2. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 1, wherein: In step (1), the corrosion is salt spray corrosion, and the spraying time of the salt spray during the salt spray corrosion process is 3S~10S; The mass percentage of sodium chloride in the salt mist is 1% to 8%.

3. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 1 or 2, characterized in that: The first cell after corrosion is subjected to different i The test of the second electrical performance under the time includes the second photoelectric performance of the first cell after corrosion tested under the first wet heat treatment conditions, t i 1h~8h; The first wet heat treatment includes: a temperature of 60° C. to 90° C. and a humidity of 60% to 95%.

4. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 1, wherein: In step (2), the third electrical property and the fourth electrical property each independently include photoelectric efficiency, and / or, m 500h~4000h.

5. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 4, characterized in that: In step (2), the second wet heat treatment includes: a temperature of 60°C to 90°C and a humidity of 60% to 95%.

6. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 1, wherein: In step (4), the simulation formula is obtained through mathematical modeling.

7. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 1, wherein: In step (5), the third battery cell is a battery cell based on the same battery type as the first battery cell, but obtained using different processes and / or process conditions.

8. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 1, wherein: In step (5), the attenuation rate P of the third cell after being prepared into a photovoltaic module is evaluated. module include: According to the simulation formula, the attenuation rate P of the third cell after being prepared into a photovoltaic module is obtained. module , and according to P module If the attenuation rate is not greater than the standard attenuation rate, the attenuation rate of the third cell when used to prepare a photovoltaic module is evaluated as qualified; Otherwise, the attenuation rate of the third solar cell when used to prepare a photovoltaic module is evaluated as unqualified.

9. The method for evaluating the relative attenuation rate of a photovoltaic module according to any one of claims 1 to 8, characterized in that: The first cell is a stack of one or both of a crystalline silicon cell and a perovskite cell.

10. The method for evaluating the relative attenuation rate of a photovoltaic module according to claim 9, characterized in that: The crystalline silicon cell includes an emitter and back passivation cell, a tunneling oxide layer passivation contact solar cell, a TOPCon stacked back electrode contact cell, a heterojunction cell or a back contact heterojunction cell.

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