Photovoltaic module and light transmittance control method for photovoltaic module

Abstract

This application relates to the field of colored photovoltaic module technology, specifically to a photovoltaic module and a method for controlling the transmittance of the photovoltaic module. The photovoltaic module includes: a transparent front panel; multiple colored layers attached to the inner surface of the transparent front panel; multiple reflective layers correspondingly attached to the side of the multiple colored layers facing away from the transparent front panel, each reflective layer and each colored layer forming a composite color block unit; solar cells disposed on the side of the composite color block unit facing away from the transparent front panel; and a supporting back panel disposed on the side of the solar cells facing away from the transparent front panel. The multiple composite color block units are configured such that the thickness of the reflective layers is adjusted based on the color parameters of the colored layers to ensure that the transmittance of each composite color block unit is the same. This achieves consistent transmittance of incident light across different color regions, eliminating uneven illumination and current mismatch problems caused by differences in transmittance, effectively suppressing the generation of hot spot effects, and improving the long-term operational safety and reliability of the colored photovoltaic module.

Description

Technical Field

[0001] This application relates to the field of colored photovoltaic module technology, specifically to a photovoltaic module and a method for controlling the transmittance of the photovoltaic module. Background Technology

[0002] With the rapid development of building-integrated photovoltaics (BIPV), colored photovoltaic modules with decorative functions have attracted much attention because they can give buildings an aesthetically pleasing visual effect. Currently, the mainstream technical solutions for achieving full-color photovoltaic modules include ultraviolet printing and screen printing. These technologies present a variety of colors and patterns by forming a colored ink layer or pattern layer on the transparent front panel (such as glass) of the module, thereby meeting the aesthetic requirements of architecture.

[0003] However, while achieving aesthetic appeal, related colored photovoltaic technologies generally suffer from a critical technical flaw. Due to the varying absorption and reflection capabilities of different colored ink layers for incident light, their transmittance is inconsistent. When these colored areas with varying transmittance cover the surface of photovoltaic cells, it causes uneven distribution of light intensity incident on the cells. During long-term operation, this uneven illumination can lead to current mismatch between the internal cells. Cells with lower transmittance will become power-consuming units due to insufficient light energy received, resulting in localized overheating, known as the hot spot effect. The hot spot effect not only significantly reduces the actual output power of the photovoltaic module and accelerates the aging of encapsulation materials, but in severe cases, it can even lead to cell rupture or fire, becoming a core challenge restricting the long-term reliability and safety of colored photovoltaic modules. Summary of the Invention

[0004] This application provides a photovoltaic module and a method for controlling the transmittance of the photovoltaic module, in order to solve the problem of hot spot effect caused by inconsistent transmittance of different color areas in existing colored photovoltaic modules.

[0005] The first aspect of this application provides a photovoltaic module, comprising: Transparent front panel; Multiple colored layers are attached to the inner surface of the transparent front panel; Multiple reflective layers are attached one-to-one to the side of the multiple colored layers facing away from the transparent front panel, and each of the reflective layers and each of the colored layers together form a composite color block unit; The battery cell is disposed on the side of the composite color block unit opposite to the transparent front panel; A support backplate is provided on the side of the battery cell facing away from the transparent front plate; The composite color block units are configured to adjust the thickness of the reflective layer based on the color parameters of the color layer, so that the transmittance of each composite color block unit is the same.

[0006] Optionally, the plurality of composite color block units are discretely distributed on the inner surface of the transparent front panel, with gaps between adjacent composite color block units.

[0007] Optionally, the reflective layer is formed of reflective ink, which includes at least one of titanium dioxide, ferric oxide and tin oxide, and at least one of terpineol or turpentine as a solvent.

[0008] A second aspect of this application provides a method for controlling the transmittance of a photovoltaic module as described above, comprising: Obtain the color parameters for each of the color layers; Obtain the original transmittance corresponding to each of the color layers; Based on the target transmittance and the original transmittance, determine the transmittance of the reflective layer corresponding to each color layer; The target thickness of the reflective layer is determined based on a preset correspondence between the light transmittance of the reflective layer and the thickness of the reflective layer. The reflective layer having the target thickness is formed on each of the plurality of color layers.

[0009] Optionally, the color parameter is an RGB color value; and / or, the reflective layer is formed of reflective ink.

[0010] Optionally, the transmittance T2 of the reflective layer satisfies: T2 = T0 / T1, where T0 is the target transmittance and T1 is the original transmittance.

[0011] Optionally, the target thickness D of the reflective layer satisfies: D = -1 / k·ln(T2), where k is the attenuation constant of the reflective layer.

[0012] Optionally, it also includes: The ink output L of the reflective layer is determined based on the target thickness D of the reflective layer and the area S of each color layer, wherein the ink output L satisfies: L = D·S.

[0013] Optionally, before forming the reflective layer having the ink output amount on each of the plurality of color layers, the method further includes: A printing parameter is generated that includes the position information of each color layer and its corresponding ink output. Based on the printing parameter, the printing device is controlled to print on each color layer one by one to form the corresponding reflective layer.

[0014] Optionally, obtaining the original transmittance corresponding to each of the color layers specifically includes: Based on the color parameters, a preset database is queried to obtain the original light transmittance corresponding to each color layer.

[0015] Beneficial effects: The photovoltaic module provided in this application uses composite color block units composed of each color layer and each reflective layer. The thickness of the reflective layer is adjusted based on the color parameters of the color layer, ensuring that the transmittance of each composite color block unit is uniform. This achieves consistent light transmittance across different color regions, largely eliminating uneven illumination and current mismatch issues caused by transmittance differences in the solar cells. It effectively suppresses hot spot effects and significantly improves the long-term operational safety and reliability of the colored photovoltaic module. Simultaneously, the color layer independently displays the desired color, while the reflective layer acts as a substrate to assist in color rendering. This ensures uniform transmittance while maintaining the module's full-color aesthetic effect, achieving a unity of color performance and photoelectric performance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a photovoltaic module according to an embodiment of this application; Figure 2 This is a flowchart of a photovoltaic module transmittance control method according to an embodiment of this application; Figure 3 This is a schematic diagram of the printing of the color layer in an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: 1. Transparent front panel; 2. Color layer; 3. Reflective layer; 4. Battery cell; 5. Supporting back panel; 6. First adhesive film; 7. Second adhesive film; 8. Color area one; 9. Color area two; 10. Color area three; 11. Color area four; 12. Color area five. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The first aspect of this application provides a photovoltaic module, which is particularly suitable for scenarios such as building-integrated photovoltaics and colored photovoltaic curtain walls, where both aesthetics and power generation efficiency are required.

[0021] Reference Figure 1 As shown, the photovoltaic module includes a transparent front panel 1, multiple colored layers 2, multiple reflective layers 3, solar cells 4, and a supporting back panel 5. The transparent front panel 1 serves as the light-receiving surface of the module and is typically made of high-transmittance glass, such as tempered glass, with its inner surface used to support the color patterns.

[0022] Multiple colored layers 2 are attached to the inner surface of the transparent front panel 1. Each colored layer 2 is used to present a specific color, such as red, blue, green, yellow, black, etc., or it can be a single color block in a complex pattern composed of multiple colors. The colored layers 2 can be formed by processes such as digital inkjet printing, screen printing, or high-temperature ink printing, and their thickness can be controlled, for example, between 0.005mm and 0.015mm.

[0023] Specifically, a reflective layer 3 is attached to the side of each color layer 2 facing away from the transparent front panel 1, and each reflective layer 3 together with each color layer 2 forms a composite color block unit. The reflective layer 3 is used to adjust the light transmittance, and at the same time serves as a substrate to enhance the color rendering effect of the color layer 2, avoiding interference from the dark battery cell 4 on the pattern colors.

[0024] Multiple composite color block units are configured such that the thickness of the reflective layer 3 is adjusted based on the color parameters of the color layer 2 to ensure that the total transmittance of each composite color block unit is the same. Specifically, the transmittance of light varies significantly between different colors of the color layer 2; for example, light-colored areas have higher transmittance, while dark-colored areas have lower transmittance. If the differences in transmittance are not compensated, the light intensity distribution incident on the surface of the solar cell 4 will be uneven, which can easily lead to current mismatch and hot spot effects.

[0025] Furthermore, the battery cell 4 is located on the side of the composite color block unit opposite to the transparent front panel 1, and is used to receive light transmitted through the composite color block unit and convert it into electrical energy. The supporting backplate 5 is located on the side of the battery cell 4 opposite to the transparent front panel 1, and is used to provide structural support and electrical protection. It can be a glass backplate or a polymer backplate. The thickness and material of the supporting backplate 5 can be the same as those of the transparent front panel 1.

[0026] By setting up composite color block units consisting of each color layer 2 and each reflective layer 3, and adjusting the thickness of the reflective layer 3 based on the color parameters of the color layer 2, the transmittance of each composite color block unit is made the same. This achieves a uniform transmittance of incident light across different color regions, largely eliminating uneven illumination and current mismatch issues in the solar cells 4 caused by transmittance differences, effectively suppressing hot spot effects, and significantly improving the long-term operational safety and reliability of the colored photovoltaic modules. At the same time, the color layer 2 is independently responsible for presenting the desired color, while the reflective layer 3 serves as a substrate to assist in color rendering. This preserves the full-color aesthetic effect of the module while ensuring uniform transmittance, achieving a unity of color performance and photoelectric performance.

[0027] In practical applications, the thickness of the reflective layer 3 can be adjusted within the range of 0mm-0.05mm. For light-colored areas with high inherent light transmittance, a thicker reflective layer 3 can be used to appropriately reduce the total light transmittance; for dark-colored areas with low inherent light transmittance, a thinner reflective layer 3 can be used; for color areas where the light transmittance is exactly equal to the target value, the reflective layer thickness can be set to zero, meaning that the reflective layer 3 can be omitted in this area. Through this differentiated adjustment, the total light transmittance of all composite color block units is unified to the target value, such as 80%. This target value can be set according to the needs of specific application scenarios. For example, skylights require high light transmittance, while decorative wall structures may allow lower light transmittance in exchange for more vibrant colors.

[0028] In one optional embodiment, multiple composite color block units are discretely distributed on the inner surface of the transparent front panel 1, with gaps between adjacent composite color block units. No color layer 2 or reflective layer 3 is provided in the gap area between adjacent color blocks, allowing light to directly pass through the gap and onto the solar cell 4. This improves the overall light transmittance of the module to a certain extent, compensating for light absorption loss in the colored areas. The presence of gaps allows the composite color block units to form a dot matrix or grid pattern. When the gap size is properly controlled, the boundaries of individual color blocks are difficult for the human eye to distinguish, and the overall pattern presents a continuous visual effect, suitable for simulating textures such as brick walls and stone. Furthermore, the gap area can also serve as a buffer space between the solar cell 4 and the transparent front panel 1, providing a channel for film flow during lamination and reducing bubbles and lamination defects.

[0029] Specifically, the shape of a single composite color block unit can be circular, square, star-shaped, hexagonal, or other arbitrary geometric shapes to adapt to different pattern design needs. The area of ​​the color block can be selected from 0.5mm² to 3mm². Too small an area will result in excessively high printing precision requirements, while too large an area may make the pattern appear grainy. The distance between the edges of adjacent color blocks can be selected from 0mm to 3mm. When the gap is 0, the color blocks are continuously distributed, suitable for full-page solid colors or gradient patterns; when the gap is greater than 0, a discrete distribution is formed. By reasonably selecting the shape, area, and gap distance of the color blocks, a balance can be achieved between light transmittance, color performance, and production efficiency.

[0030] In one optional embodiment, the reflective layer 3 is formed of reflective ink, which includes at least one of titanium dioxide, ferric oxide, and tin oxide, and at least one of terpineol or turpentine as a solvent. The formulation of this reflective ink satisfies both optical performance and process adaptability. Titanium dioxide has a high refractive index and high reflectivity, effectively reflecting light and enhancing the color rendering effect of the color layer 2; ferric oxide and tin oxide also have good reflective properties and good adhesion to the glass substrate. Terpineol and turpentine, as solvents, can adjust the viscosity of the ink, making it suitable for inkjet printing or screen printing processes, while also having good volatility, making it less prone to bubbles or cracks during drying.

[0031] Furthermore, referring to Figure 1 As shown, the photovoltaic module also includes a first encapsulating film 6 and a second encapsulating film 7. During lamination, the layers can be sequentially stacked in the following order: transparent front panel 1, composite color block unit, first encapsulating film 6, solar cell 4, second encapsulating film 7, and supporting back panel 5. After vacuum heating and lamination, the layers are cured and encapsulated, bonding them together as a single unit. The first encapsulating film 6 is made of transparent material and is used for light transmission and bonding the composite color block unit to the solar cell 4. The second encapsulating film 7 can be selected as transparent or white encapsulating film as needed, and is used to bond the solar cell 4 to the supporting back panel 5 and provide cushioning protection. Alternatively, it can be flexibly adjusted according to actual needs, for example, only one encapsulating film can be used, or neither film can be used, and the above components can be fixed through other fixing methods.

[0032] The second aspect of this application provides a method for controlling the light transmittance of the aforementioned photovoltaic module. This method, through the combination of algorithms and processes, achieves precise adjustment of the light transmittance of the composite color block unit. (Refer to...) Figure 2 As shown, the method includes the following steps: Obtain the color parameters for each color layer 2; Obtain the original transmittance corresponding to each color layer 2; Based on the target transmittance and the original transmittance, determine the transmittance of the reflective layer corresponding to each color layer 2; The target thickness of the reflective layer 3 is determined based on the preset correspondence between the light transmittance and the thickness of the reflective layer; A reflective layer 3 with a target thickness is formed on each of the multiple color layers 2.

[0033] Specifically, firstly, the color parameters of each color layer 2 are obtained. The color parameters can be at least one of the following: red-green-blue (RGB) color values, cyan-magenta-yellow-black (CMYK) color values, and CIELAB color values ​​(Lab color values). For example, due to the high compatibility of RGB color values ​​with digital printing devices, RGB color values ​​can be used as an exemplary solution. In practical implementation, the target pattern can be analyzed using image processing software, decomposing the pattern into multiple color block units, and extracting the color parameters of each color block. It should be noted that for a single-color color layer 2, its transmittance is determined by the hue, saturation, and brightness of that color.

[0034] Secondly, the original transmittance of each color layer 2 is obtained by querying a pre-set database based on the color parameters. This database is established through experimental testing, specifically by pre-printing different colors of colored ink (without superimposed reflective layer 3) individually on a transparent front panel 1 (such as glass), measuring their transmittance, and recording the correspondence between color parameters and transmittance in the database. For mixed colors or gradient colors, their equivalent transmittance can be calculated through interpolation or a color mixing model. It should be noted that the original transmittance of color layer 2 is related to its own ink output (i.e., thickness). In the process of establishing the database in this application, the transmittance under standard ink output (e.g., 100% ink output) is used as the benchmark value for each color.

[0035] Next, based on the preset target transmittance and the original transmittance of color layer 2, the target transmittance of the reflective layer 3 corresponding to each color layer 2 is determined. The target transmittance is preset according to the application scenario of the component, for example, 80%. The target transmittance of the reflective layer 3 and the original transmittance of color layer 2 satisfy a product relationship, that is, the total transmittance of the composite color block unit is equal to the transmittance of color layer 2 multiplied by the transmittance of the reflective layer. Therefore, the target transmittance of the reflective layer 3 is equal to the target total transmittance divided by the original transmittance of color layer 2.

[0036] Then, based on the preset correspondence between the transmittance and thickness of the reflective layer, the target thickness of reflective layer 3 is determined. This correspondence follows the Lambert-Beer Law, which states that transmittance decreases exponentially with increasing thickness. Using this law, the required thickness can be deduced from the target transmittance of reflective layer 3.

[0037] Finally, reflective layers 3 with target thicknesses are formed on multiple color layers 2, so that the light transmittance of each composite color block unit formed by the color layer 2 and the reflective layer 3 is a preset target light transmittance. The reflective layer 3 can be formed by digital inkjet printing, and the thickness can be adjusted by controlling the printhead to spray a set amount of reflective ink in the corresponding color block area.

[0038] Using the above method, even if the target pattern contains multiple colors, it can ensure that the final light transmittance of each color block unit is completely consistent, fundamentally solving the problem of hot spot effect caused by differences in light transmittance.

[0039] In one optional implementation, the color parameters use RGB color values. Referring to Table 1, which shows the original transmittance corresponding to the RGB values ​​of different colors, each color channel typically takes an integer value between 0 and 255. When obtaining the color parameters of color layer 2, the RGB values ​​of each color block can be directly read from the design file without additional color space conversion, simplifying the data processing flow. Furthermore, the RGB values ​​have a good correspondence with the driving parameters of the inkjet printer, facilitating the subsequent mapping of transmittance adjustment results to printed grayscale values. In practical applications, for solid color blocks, the RGB values ​​are relatively uniform; for gradients or complex patterns, the RGB values ​​of the pixels within each color block can be averaged to obtain the color parameters representing that color block.

[0040] Table 1

[0041] In one optional implementation, the transmittance T2 of the reflective layer satisfies: T2 = T0 / T1, where T0 is the preset target transmittance and T1 is the original transmittance of the color layer 2. The physical meaning of this formula is that the transmittance of the composite color block unit is equal to the product of the transmittance of the color layer 2 and the transmittance of the reflective layer. Since light passes through the color layer 2 and the reflective layer 3 sequentially, the attenuation effects of the two layers are additive, thus the total transmittance satisfies a product relationship. By dividing the target total transmittance by the original transmittance of the color layer 2, the required transmittance compensation value provided by the reflective layer 3 can be obtained. For example, if the target transmittance is 80%, and the original transmittance of a certain color layer 2 is 95%, then the target transmittance of the reflective layer 3 should be 80% ÷ 95% ≈ 84.2%; if the original transmittance of another color layer 2 is 86%, then the target transmittance of the reflective layer 3 should be 80% ÷ 86% ≈ 93.0%; if the original transmittance of a certain color layer 2 is exactly 80%, then the target transmittance of the reflective layer 3 is 100%, meaning that there is no need to set up a reflective layer 3. This formula is simple and clear, and easy to calculate directly in the control software.

[0042] In one alternative embodiment, the reflective layer 3 is formed of reflective ink, and the target thickness D of the reflective layer 3 satisfies: D = -1 / k·ln(T²), where k is the attenuation constant of the reflective layer 3. This formula originates from the Lambert-Beer law, which describes the attenuation law of light propagating in an absorbing medium. Specifically, when light passes perpendicularly through a uniform absorbing medium of thickness D, the transmittance T and thickness D satisfy an exponential attenuation relationship: T = e^(-k·D), where k is the absorption coefficient of the medium (i.e., the attenuation constant), which depends on the material composition of the ink and the wavelength of the light. Taking the natural logarithm of both sides of the equation, we obtain the thickness D = -1 / k·ln(T). In this application, T² is the target transmittance required for the reflective layer 3, and substituting it into the formula allows us to calculate the required thickness. This formula provides a mathematical basis for the precise control of the reflective layer thickness.

[0043] In practical implementation, the attenuation constant k of the reflective ink is calibrated experimentally. For example, by printing reflective ink of different thicknesses on a glass substrate, measuring the transmittance at each thickness, and fitting the exponential attenuation relationship to the Lambert-Beer law, the value of k can be determined. This attenuation constant is the fundamental parameter for subsequent thickness calculations. In actual production, the thickness of the reflective ink can be controlled by adjusting the ink output of the inkjet printer. Since there is a linear relationship between ink output and thickness, precise control of the ink output allows for precise control of the reflective layer thickness.

[0044] In an optional implementation, the method further includes determining the ink output L of the reflective layer 3 based on the target thickness D of the reflective layer 3 and the area S of each color layer 2, wherein the ink output L satisfies: L = D · S. Ink output refers to the volume of ink ejected by the printing equipment onto a single color block area, typically measured in picoliters or microliters. Since there is a linear relationship between the thickness of the reflective ink and the ink output per unit area, multiplying the target thickness by the color block area yields the total ink output required for that color block. In actual production, inkjet printers precisely control the ink output by controlling the number of ejections per unit area and the volume of ink droplets ejected each time. By embedding this formula into the printing control software, differentiated adjustment of the ink output for different color block areas can be achieved, thereby enabling precise control of the reflective layer thickness.

[0045] In one optional implementation, before forming reflective layers 3 with corresponding ink output on multiple color layers 2, printing parameters are generated, including the position information of each color layer 2 and its corresponding ink output. These printing parameters are key parameters connecting design data and production equipment. Specifically, after extracting color parameters for each color block, querying the original transmittance, calculating the target transmittance of the reflective layer 3, calculating the target thickness, and calculating the ink output, the position coordinates, shape, size, and corresponding reflective ink output of all color blocks need to be integrated into a file format recognizable by the equipment. These printing parameters may include the outline information of each color block (such as center coordinates, shape type, and size), ink output value, and printing order. After generating the printing parameters, they can be imported into printing equipment such as inkjet printers or screen printing equipment to achieve automated production. That is, the printing equipment is controlled to print sequentially on each color layer 2 according to these printing parameters to form the corresponding reflective layer 3. During printing, the printhead moves to the target color block area based on the position information and precisely ejects reflective ink according to the ink output corresponding to that area, completing the printing of all color blocks in sequence. The above methods enable high-precision differential control of the reflective layer thickness. By pre-generating printing parameters, simulation verification can be performed before production to ensure the accurate calculation of ink output for all color blocks, thus avoiding errors during the production process.

[0046] In one optional implementation, the original transmittance of each color layer 2 is obtained by querying a pre-set database. This database is pre-established and stores the correspondence between different color parameters and the transmittance of color inks in individual printing states. The database is established as follows: various colors of color ink are printed on the glass front panel, and a transmittance meter is used to measure the transmittance of each color at different ink volumes or thicknesses. The color parameters (such as RGB values) are then associated and stored with the measured transmittance. In practical applications, once the color parameters of each color layer 2 are obtained, the original transmittance of that color layer 2 can be obtained directly by searching the database using those parameters. This query method has the advantages of being fast, accurate, and highly repeatable, providing a reliable data foundation for subsequent adjustment of the reflective layer 3.

[0047] In one optional implementation, after obtaining the target pattern, the target pattern undergoes overall preliminary optimization. The color of the solar cell 4 serves as the background color, which is the light-absorbing color of the solar cell 4. In some embodiments, the background color is black or dark blue. The core of the solar cell 4 is to achieve photoelectric conversion by absorbing visible and near-infrared light from sunlight. Black and dark blue are high-absorption colors, which can minimize the reflection loss of sunlight on the surface of the solar cell 4 and avoid a decrease in power generation efficiency due to reflection of the background color.

[0048] Specifically, the color information of solar cell 4 in the photovoltaic module is obtained. Solar cell 4 is typically bluish-black. During optimization, the bluish-black color of solar cell 4 is used as the background color for compensation in the color layer 2, and the saturation of the target pattern is adjusted according to the preset target transmittance. Saturation and transmittance are negatively correlated; that is, higher saturation results in more vibrant colors and lower transmittance for the corresponding composite color block units, while lower saturation results in paler colors and higher transmittance for the corresponding composite color block units. By adjusting the saturation, the target pattern achieves the desired color performance while meeting the transmittance requirements.

[0049] Specifically, the target transmittance can be flexibly set according to the user's input transmittance requirements and preferences, or the system can automatically identify and determine the optimal transmittance based on the color distribution of the target pattern. When using the automatic identification method, the system performs color analysis on the target pattern, and automatically calculates a target transmittance that balances color performance and power generation efficiency based on the original transmittance distribution of each color layer 2 and the preset transmittance optimization range. Based on this target transmittance, the system then determines the ink output of the corresponding reflective layer 3 for each color layer 2, thereby achieving precise control of the transmittance.

[0050] In one specific implementation, refer to Figure 3 As shown, taking a Mickey Mouse pattern as an example, the pattern is divided into five colored areas: colored area 1 (8), colored area 2 (9), colored area 3 (10), colored area 4 (11), and colored area 5 (12). Colored area 1 (8) corresponds to the black part of Mickey's head, colored area 2 (9) corresponds to the gray part of the background, colored area 3 (10) corresponds to the skin color of the face, colored area 4 (11) corresponds to the red part of the clothes, and colored area 5 (12) corresponds to the yellow part of the shoes. The area of ​​each colored area is 1 mm², and the preset target light transmittance is 80%. It should be noted that the area, shape, and ink output of the reflective layer 3 can be adjusted according to the complexity of the actual pattern and the precision of the equipment, and are not limited to the specific values ​​listed in this embodiment.

[0051] First, the RGB values ​​of each color region are extracted using image processing software. The RGB values ​​corresponding to the five color regions are obtained separately. Based on these RGB values, a preset database is queried to obtain the original transmittance corresponding to each color layer 2: color region 1 (8) is 95%, color region 2 (9) is 86%, color region 3 (10) is 80%, color region 4 (11) is 86%, and color region 5 (12) is 85%.

[0052] Subsequently, the target transmittance of the reflective layer 3 in each region is calculated according to the formula T2=T0 / T1: 84.2% for color region 1 (8), 93% for color region 2 (9), 10% for color region 3 (10), 93% for color region 4 (11), and 94.1% for color region 5 (12). Then, the target thickness of the reflective layer 3 in each region is calculated according to the Lambert-Beer Law D=-1 / k·ln(T2), and the ink output of the reflective layer 3 in each region is obtained according to the ink output formula L = D·S. After generating printing parameters containing the position coordinates of each color region and its corresponding ink output, the printing equipment is controlled to print reflective ink one by one on each of the color layers 2 already formed on the inner surface of the transparent front plate 1. Since the original transmittance of color region 3 (10) is already equal to the target value, no reflective layer 3 is set. After subsequent drying and curing, the total transmittance of each composite color block unit is uniformly set to 80%.

[0053] By using the above method, the light transmittance of different color areas in the Mickey Mouse head pattern is made consistent, which effectively eliminates the problem of uneven lighting and current mismatch of battery cell 4 caused by differences in light transmittance, greatly suppresses the generation of hot spot effect, and at the same time preserves the richness of pattern colors.

[0054] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A photovoltaic module, characterized by, include: Transparent front panel (1); Multiple colored layers (2) are attached to the inner surface of the transparent front panel (1); Multiple reflective layers (3) are attached one-to-one to the side of the multiple colored layers (2) facing away from the transparent front panel (1), and each of the reflective layers (3) and each of the colored layers (2) together form a composite color block unit; The battery cell (4) is disposed on the side of the composite color block unit opposite to the transparent front panel (1); A support backplate (5) is provided on the side of the battery cell (4) facing away from the transparent front plate (1); The composite color block units are configured to adjust the thickness of the reflective layer (3) based on the color parameters of the color layer (2) so that the transmittance of each composite color block unit is the same.

2. The photovoltaic module of claim 1, wherein, The multiple composite color block units are discretely distributed on the inner surface of the transparent front panel (1), and there are gaps between adjacent composite color block units.

3. The photovoltaic module of claim 1, wherein, The reflective layer (3) is formed of reflective ink, which includes at least one of titanium dioxide, ferric oxide and tin oxide, and at least one of terpineol or turpentine as a solvent.

4. A method for controlling the light transmittance of a photovoltaic module as described in any one of claims 1-3, characterized in that, include: Obtain the color parameters of each of the color layers (2); Obtain the original transmittance corresponding to each of the color layers (2); Based on the target transmittance and the original transmittance, determine the transmittance of the reflective layer corresponding to each of the color layers (2); The target thickness of the reflective layer (3) is determined according to the preset correspondence between the light transmittance of the reflective layer and the thickness of the reflective layer; The reflective layer (3) having the target thickness is formed on each of the multiple color layers (2).

5. The method according to claim 4, characterized in that, The color parameters are RGB color values; and / or, the reflective layer (3) is formed of reflective ink.

6. The method according to claim 4, characterized in that, The light transmittance T2 of the reflective layer satisfies: T2=T0 / T1, where T0 is the target light transmittance and T1 is the original light transmittance.

7. The method according to claim 4, characterized in that, The target thickness D of the reflective layer (3) satisfies: D = -1 / k· ln(T2), where k is the attenuation constant of the reflective layer (3).

8. The method according to claim 4, characterized in that, Also includes: Based on the target thickness D of the reflective layer (3) and the area S of each color layer (2), the ink output L of the reflective layer (3) is determined, and the ink output L satisfies: L=D·S.

9. The method according to claim 8, characterized in that, Before forming the reflective layer (3) having the ink output amount on each of the plurality of color layers (2), the method further includes: Generate printing parameters containing the position information of each color layer (2) and its corresponding ink output. Based on the printing parameters, control the printing device to print on each color layer (2) one by one to form the corresponding reflective layer (3).

10. The method according to any one of claims 4-9, characterized in that, Obtaining the original transmittance corresponding to each of the color layers (2) specifically includes: Based on the color parameters, a preset database is queried to obtain the original transmittance corresponding to each color layer (2).

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