Detection method of photovoltaic module

Abstract

The embodiment of the invention relates to the field of photovoltaic technology, and provides a photovoltaic module detection method, which comprises the following steps: laying a welding strip on the surface of a battery piece, fixing the welding strip on the battery piece through a plurality of glue points, and connecting the plurality of battery pieces through the welding strip to form a battery string; performing first image detection on the battery string to obtain a detection image of each battery piece in the battery string; judging whether each battery piece in the battery string meets a preset condition or not according to the detection image, and judging that the battery string is sent to a next working procedure or a repair working procedure; performing second image detection on the battery string to obtain a glue point image of each battery piece in the battery string; and according to the glue point image, obtaining a through printing ratio corresponding to each battery piece, and according to the through printing ratio, judging that the battery string is sent to a next process, a glue supplementing process or a repairing process. According to the photovoltaic module detection method provided by the embodiment of the invention, at least the manufacturing efficiency of the photovoltaic module can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic technology, and in particular to a method for detecting a photovoltaic component. Background Art

[0002] Photovoltaic modules are components that use the photovoltaic effect to generate electricity. They are usually composed of solar cells, welding ribbons, adhesive films and cover plates. Solar cells are an important component of the main components. The welding performance of solar cells at the component end directly affects the power generation performance and power of photovoltaic modules.

[0003] At present, the busbar-free technology is a cost-reduction technology that removes the busbar and solder joints on the battery cell. The busbar-free structure can significantly reduce the silver paste cost of the battery cell. The existing busbar-free solution arranges glue points on the busbar-free battery cell by dispensing or printing glue to strengthen the connection between the glue points and the solder strips. After the series connection process, the glue points have been completely fixed on the battery cell, and then the battery cell is inspected for defects through series inspection. When the battery string has problems such as hidden cracks, broken pieces, and glue leakage, the operator repairs the battery string. Since the glue points on the surface of the battery have solidified, the busbar-free battery string can only be repaired by replacing the cell, and it is impossible to replace the solder strip or re-weld like conventional batteries; when the battery has leakage, the operator also repairs it by replacing the cell, which increases the process time and component production cost.

[0004] Therefore, there is an urgent need to improve the existing process to increase the manufacturing efficiency of photovoltaic modules. Summary of the invention

[0005] The embodiment of the present application provides a method for detecting a photovoltaic module, which is at least beneficial to improving the manufacturing efficiency of the photovoltaic module.

[0006] According to some embodiments of the present application, on the one hand, the embodiments of the present application provide a method for detecting a photovoltaic module, including: laying a welding tape on the surface of a battery cell, and fixing the welding tape on the battery cell through multiple glue points, and connecting multiple battery cells through the welding tape to form a battery string; performing a first image detection on the battery string to obtain a detection image of each battery cell in the battery string; judging whether each battery cell in the battery string meets a preset condition based on the detection image, if all the battery cells in the battery string meet the preset condition, the battery string is sent to the next process; if at least one battery cell in the battery string does not meet the preset condition, the battery string is sent to a repair process; performing a second image detection on the battery string , to obtain the glue spot image of each battery cell in the battery string; obtain the missing print ratio corresponding to each battery cell according to the glue spot image, and the missing print ratio is expressed as the ratio of the number of unqualified glue spots on each battery cell to the total number of preset glue spot positions on the battery cell; if the missing print ratios of all battery cells in the battery string are less than or equal to the first preset value, the battery string is sent to the next process; if the missing print ratio of at least one battery cell in the battery string is greater than the first preset value, and the missing print ratios of all battery cells in the battery string are less than the second preset value, the battery string is sent to the glue filling process; if the missing print ratio of at least one battery cell in the battery string is greater than or equal to the second preset value, the battery string is sent to the rework process.

[0007] In some embodiments, if the missing printing ratios of all battery cells in the battery string are less than or equal to a first preset value, sending the battery string to the next process includes: obtaining the glue deficiency ratio corresponding to each solder strip according to the glue dot image, the glue deficiency ratio being the ratio of the number of unqualified glue points corresponding to each solder strip to the total number of preset glue point positions corresponding to the solder strip; if the glue deficiency ratio is less than or equal to a third preset value, sending the battery string to the next process; if the glue deficiency ratio is greater than the third preset value, sending the battery string to the glue filling process.

[0008] In some embodiments, the third preset value is 1.5% to 2.5%.

[0009] In some embodiments, if at least one battery cell in a battery string does not meet a preset condition, the battery string is sent to a rework process including: cutting the battery cells in the battery string that do not meet the preset condition, connecting the remaining battery cells in the battery string in series to form a first reorganized battery string; and performing a second image inspection on the first reorganized battery string.

[0010] In some embodiments, if the leakage printing ratio of at least one battery cell in the battery string is greater than or equal to the second preset value, sending the battery string to the rework process includes: cutting the battery cells in the battery string whose leakage printing ratio is greater than or equal to the second preset value, and connecting the remaining battery cells in the battery string in series to form a second reorganized battery string; if the leakage printing ratios of all battery cells in the second reorganized battery string are less than or equal to the first preset value, sending the second reorganized battery string to the next process; if the leakage printing ratio of at least one battery cell in the second reorganized battery string is greater than the first preset value, and the leakage printing ratios of all battery cells in the second reorganized battery string are less than the second preset value, sending the second reorganized battery string to the glue filling process.

[0011] In some embodiments, after cutting the battery cells with an underprinting ratio greater than or equal to the second preset value in the battery string, the method further includes: connecting in series the cut battery cells with an underprinting ratio greater than or equal to the second preset value to form a third reorganized battery string; and sending the third reorganized battery string to a glue filling process.

[0012] In some embodiments, the soldering ribbon is fixed to the battery cell via a plurality of glue spots, including: the glue spots are located on the surface of the soldering ribbon away from the battery cell; or, the glue spots are located between the soldering ribbon and the battery cell.

[0013] In some embodiments, if the glue spot is located on the surface of the soldering ribbon away from the battery cell, the unqualified glue spot includes the following situations: there is no glue spot on the surface of the soldering ribbon.

[0014] In some embodiments, if the glue spot is located between the soldering ribbon and the battery cell, the unqualified glue spot includes the following situations: the diameter of the glue spot is smaller than the diameter of the soldering ribbon; or the spacing between the glue spot and the soldering ribbon is greater than 0.

[0015] In some embodiments, the first preset value is 1.5% to 2.5%; the second preset value is 4% to 6%.

[0016] The technical solution provided by the embodiments of the present application has at least the following advantages:

[0017] In the detection method of photovoltaic modules provided in the embodiment of the present application, the battery cells are connected by welding strips, and the welding strips are fixed on the battery cells by multiple glue points to form a battery string without a main grid structure. The main grid structure is conducive to reducing the cost of silver paste, reducing shading loss, shortening the current transmission path, reducing the series resistance, and improving the power of photovoltaic modules. First, the battery string is subjected to a first image detection, and it is determined whether each battery cell in the battery string meets the preset requirements according to the result of the first image detection. If at least one battery cell does not meet the preset requirements, the battery string is sent to the rework process; if all battery cells meet the preset requirements, the battery string is sent to the next process. It is judged in advance that the battery cells in the battery string do not meet the preset conditions or have defects, and the battery strings that do not meet the preset conditions are sent to the rework process, which can avoid the problem of increased time and cost caused by the defective battery cells entering the subsequent process and then rework. Then, the battery string is subjected to a second image detection to obtain the glue point image of each battery cell in the battery string, and the corresponding leakage ratio of each battery cell is obtained according to the glue point image, and the battery string is judged based on the leakage ratio to which process it will be sent. For example, if the leakage ratio of all cells in the battery string is less than or equal to the first preset value, the battery string is sent to the next process; if the leakage ratio of at least one cell in the battery string is greater than or equal to the second preset value, the battery string is sent to the repair process; if the leakage ratio of all cells in the battery string is less than the second preset value, and the leakage ratio of at least one cell is greater than the first preset value, the cell is sent to the glue filling process. When the leakage ratio corresponding to the cell is greater than the first preset value, it means that the cell needs to be glued, but when the leakage ratio of the cell is greater than the second preset value, it means that the cell needs to be glued a lot, so the glue filling time of a single cell is relatively long. If all the cell strings that need to be glued are waiting in the glue filling process, a large number of cell strings will be piled up in the glue filling process, which will further reduce the manufacturing efficiency of photovoltaic modules. Therefore, the battery strings corresponding to the battery cells whose leakage printing ratio is between the first preset value and the second preset value are sent to the glue filling process, and the battery strings corresponding to the battery cells whose leakage printing ratio is greater than the second preset value are sent to the repair process. Different processes can be selected for battery strings in different conditions to avoid the problem of a large number of battery strings queuing in the glue filling process, thereby improving the production efficiency of photovoltaic modules and saving production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present application or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A flowchart corresponding to a photovoltaic module detection method provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the structure of a battery string provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of the structure of another battery string provided in an embodiment of the present application;

[0022] Figure 4 A flowchart corresponding to another photovoltaic module detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] As can be seen from the background technology, the manufacturing efficiency of photovoltaic modules needs to be improved.

[0024] The present application provides a photovoltaic module detection method, which is at least beneficial to improving the manufacturing efficiency of photovoltaic modules.

[0025] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0026] In the description of the embodiments of the present application, “plurality” means more than two, unless otherwise clearly and specifically defined.

[0027] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0029] In the description of the embodiments of the present application, technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0030] In the description of the embodiments of the present application, when a certain component “includes” another component, unless otherwise stated, other components are not excluded and other components may be further included.

[0031] The terms used in the description of the various described embodiments herein are used only to describe specific embodiments and are not intended to be limiting. As used in the description of the various described embodiments and the appended claims, "components" are also intended to include plural forms unless the context clearly indicates otherwise.

[0032] The following will describe the various embodiments of the present application in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present application, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed in the present application can be implemented.

[0033] Figure 1 A flowchart corresponding to a photovoltaic module detection method provided in an embodiment of the present application.

[0034] refer to Figure 1 The photovoltaic module detection method provided in the embodiment of the present application includes:

[0035] Step S101: Laying a soldering tape on the surface of a battery cell and fixing the soldering tape on the battery cell through a plurality of glue points. A plurality of battery cells are connected through the soldering tape to form a battery string.

[0036] In some embodiments, the cell may be any one of a PERC cell (Passivated Emitter and Rear Cell), a PERT cell (Passivated Emitter and Rear Totally-diffused cell), a TOPCon cell (Tunnel Oxide Passivated Contact), a HIT / HJT cell (Heterojunction Technology), or a BC cell (Back Contact).

[0037] In some embodiments, the cell may be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell or a multi-compound solar cell. The multi-compound solar cell may specifically be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell or a perovskite solar cell.

[0038] The battery cell may include a first surface and a second surface that are arranged opposite to each other. In some embodiments, the first surface of the battery cell has a first grid line, and the second surface of the battery cell has a second grid line, and the polarity of the first grid line and the second grid line are different. In other embodiments, the first grid line and the second grid line may both be located on the first surface of the battery cell.

[0039] Figure 2 A schematic diagram of the structure of a battery string provided in an embodiment of the present application.

[0040] refer to Figure 2 In some embodiments, the first surface 11 of the cell 10 has a first grid line 13, and the second surface 12 of the cell 10 has a second grid line (not shown in the figure), and the first grid line 13 and the second grid line have different polarities. That is, the grid lines of different polarities on the cell 10 are located on both side surfaces of the cell 10.

[0041] refer to Figure 2 When the grid lines of different polarities on the battery cell 10 are respectively located on both side surfaces of the battery cell 10, during the series connection process, one end of the welding ribbon 20 is located on the first surface 11 of one battery cell 10 and electrically contacts the first grid line 13 of the battery cell 10, and the other end of the welding ribbon 20 is located on the second surface 12 of another battery cell 10 and electrically contacts the second grid line of the battery cell 10, thus forming a battery string structure.

[0042] Figure 3 A schematic diagram of the structure of another battery string provided in an embodiment of the present application.

[0043] refer to Figure 3In other embodiments, the first surface 11 of the battery cell 10 has a first grid line 13 and a second grid line 14, the first grid line 13 and the second grid line 14 have different polarities, and the first grid line 13 and the second grid line 14 are staggered on the first surface 11. That is, the grid lines of different polarities on the battery cell 10 are located on the same side surface of the battery cell 10.

[0044] refer to Figure 3 When the grid lines of different polarities on the battery cell 10 are located on the same side surface of the battery cell 10, during the series connection process, for the middle battery cell 10, the first grid line 13 on the first surface 11 is connected to the second grid line 14 on the left battery cell 10 through the left welding strip 20, and the second grid line 14 on the first surface 11 is connected to the first grid line 13 on the right battery cell 10 through the right welding strip 20.

[0045] It should be noted that Figure 2 and Figure 3 The number of battery cells 10 in the battery string shown in the figure does not constitute a limitation on the battery string, and the number of battery cells 10 in the battery string can be adjusted according to actual conditions.

[0046] Step S102: performing a first image detection on the battery string to obtain a detection image of each battery cell in the battery string; and judging whether each battery cell in the battery string meets a preset condition according to the detection image.

[0047] If all the battery cells in the battery string meet the preset conditions, the battery string is sent to the next process; if at least one battery cell in the battery string does not meet the preset conditions, the battery string is sent to the repair process.

[0048] The first image detection method can be photoluminescence (PL) detection or electroluminescence (EL) detection. PL detection evaluates the quality and performance of photovoltaic modules by irradiating photovoltaic materials and measuring their luminous intensity. PL detection can provide relevant information such as the optical properties and defects of materials, which is very helpful for discovering defects and damage in photovoltaic modules; EL detection is to apply voltage to solar cells so that the electrons and holes inside the cells emit light when they recombine, thereby observing the structure and performance of the cells. EL detection can intuitively display potential defects in solar cell modules, such as cracks or fragments, which is of great significance for improving the quality and performance of photovoltaic modules.

[0049] During the first image detection process, the battery cells in the battery string that do not meet the preset conditions or have defects are first determined, and the battery strings that do not meet the preset conditions are sent to the rework process, which can avoid the problem of increased time and cost caused by rework of defective battery cells after entering the subsequent process.

[0050] Step S103: performing a second image detection on the battery string to obtain a glue point image of each battery cell in the battery string.

[0051] The second inspection image can be automated optical inspection (AOI). AOI inspection is a device that detects common defects encountered in photovoltaic modules during welding production based on optical principles. The AOI inspection principle is to use camera technology to output the reflected light intensity of the inspected object as a quantitative grayscale value, and then analyze and determine the defects and classify them by comparing them with the grayscale value of the standard image.

[0052] When the grid lines of two polarities on the battery cell are located on the two sides of the battery cell respectively, there are two groups of corresponding glue dot images of the battery cell; when the grid lines of two polarities on the battery cell are located on the same side surface of the battery cell, there is one group of corresponding glue dot images of the battery cell.

[0053] Step S104: obtaining the missing printing ratio corresponding to each battery cell according to the glue spot image, where the missing printing ratio is represented by the ratio of the number of unqualified glue spots on each battery cell to the total number of preset glue spot positions on the battery cell.

[0054] If the missing printing ratio of all cells in the battery string is less than or equal to the first preset value (corresponding to Figure 1 If the condition 1 is met in the battery string, the battery string is sent to the next process; if the missing printing ratio of at least one battery cell in the battery string is greater than the first preset value, and the missing printing ratios of all battery cells in the battery string are less than the second preset value (corresponding to Figure 1 In the same battery string, the number of battery cells whose missed printing ratio is greater than the first preset value and less than the second preset value may be multiple, for example, 1, 2, 4 or 6; if at least one battery cell in the battery string has a missed printing ratio greater than or equal to the second preset value (corresponding to Figure 1 If the condition 3 is met in the test, the battery string is sent to the rework process; in the same battery string, the number of battery cells with the missed printing ratio greater than or equal to the second preset value can be multiple, for example, 1, 2, 4 or 6.

[0055] When the grid lines of two polarities on the battery cell are located on the two sides of the battery cell respectively, the corresponding battery cell has two groups of corresponding glue dot images and the same battery cell has two groups of corresponding missing printing ratios. If the missing printing ratios corresponding to the two groups of glue dot images of the battery cell are both less than or equal to the first preset value, it is judged that the missing printing ratio of the battery cell is less than or equal to the first preset value; if the missing printing ratios corresponding to the two groups of glue dot images of the battery cell are both less than the second preset value, and at least one group of glue dot images corresponding to the missing printing ratio is greater than the first preset value, it is judged that the missing printing ratio of the battery cell is greater than the first preset value and less than the second preset value; if at least one group of glue dot images among the missing printing ratios corresponding to the two groups of glue dot images of the battery cell has a missing printing ratio greater than or equal to the second preset value, it is judged that the missing printing ratio of the battery cell is greater than or equal to the second preset value.

[0056] In the detection method of photovoltaic modules provided in the embodiment of the present application, the battery cells are connected by welding strips, and the welding strips are fixed on the battery cells by multiple glue points to form a battery string without a main grid structure. The main grid structure is conducive to reducing the cost of silver paste, reducing shading loss, shortening the current transmission path, reducing the series resistance, and improving the power of photovoltaic modules. First, the battery string is subjected to a first image detection, and it is determined whether each battery cell in the battery string meets the preset requirements according to the result of the first image detection. If at least one battery cell does not meet the preset requirements, the battery string is sent to the rework process; if all battery cells meet the preset requirements, the battery string is sent to the next process. It is judged in advance that the battery cells in the battery string do not meet the preset conditions or have defects, and the battery strings that do not meet the preset conditions are sent to the rework process, which can avoid the problem of increased time and cost caused by the defective battery cells entering the subsequent process and then rework. Then, the battery string is subjected to a second image detection to obtain the glue point image of each battery cell in the battery string, and the corresponding leakage ratio of each battery cell is obtained according to the glue point image, and the battery string is judged based on the leakage ratio to which process it will be sent. For example, if the leakage ratio of all cells in the battery string is less than or equal to the first preset value, the battery string is sent to the next process; if the leakage ratio of at least one cell in the battery string is greater than or equal to the second preset value, the battery string is sent to the repair process; if the leakage ratio of all cells in the battery string is less than the second preset value, and the leakage ratio of at least one cell is greater than the first preset value, the cell is sent to the glue filling process. When the leakage ratio corresponding to the cell is greater than the first preset value, it means that the cell needs to be glued, but when the leakage ratio of the cell is greater than the second preset value, it means that the cell needs to be glued a lot, so the glue filling time of a single cell is relatively long. If all the cell strings that need to be glued are waiting in the glue filling process, a large number of cell strings will be piled up in the glue filling process, which will further reduce the manufacturing efficiency of photovoltaic modules. Therefore, the battery strings corresponding to the battery cells whose leakage printing ratio is between the first preset value and the second preset value are sent to the glue filling process, and the battery strings corresponding to the battery cells whose leakage printing ratio is greater than the second preset value are sent to the repair process. Different processes can be selected for battery strings in different conditions to avoid the problem of a large number of battery strings queuing in the glue filling process, thereby improving the production efficiency of photovoltaic modules and saving production costs.

[0057] The preset glue point position on the battery cell refers to the position on the battery cell where the glue point needs to be set.

[0058] In some embodiments, the soldering tape is fixed to the battery cell by multiple glue dots, including: the glue dots are located on the surface of the soldering tape away from the battery cell, and / or the glue dots are located between the soldering tape and the battery cell. There are two ways to fix the soldering tape to the battery cell by glue dots. One is to first apply glue on the battery cell, then lay the soldering tape, and then solidify the glue dots to fix the soldering tape on the battery cell, so that the glue dots are located between the soldering tape and the battery cell; the other is to first lay the soldering tape on the battery cell, then apply glue on the soldering tape, and then solidify the glue dots to fix the soldering tape on the battery cell, so that the glue dots are located on the surface of the soldering tape away from the battery cell.

[0059] If the glue spot is located on the surface of the solder ribbon away from the battery cell, the unqualified glue spot includes the following situations: There is no glue spot on the surface of the solder ribbon. Since the glue spot is located on the surface of the solder ribbon away from the battery cell, the solder ribbon is laid first and then the glue is applied. If there is no glue on the surface of the solder ribbon, it can be judged that the point is missing, which is an unqualified glue spot.

[0060] If the glue spot is located between the soldering ribbon and the battery cell, unqualified glue spots include the following situations: the diameter of the glue spot is smaller than the diameter of the soldering ribbon; or, the spacing between the glue spot and the soldering ribbon is greater than 0. Since the glue spot is located between the soldering ribbon and the battery cell, the glue is applied first and then the soldering ribbon is laid, and there is no glue on the surface of the soldering ribbon, it is necessary to determine whether the glue spot is an unqualified glue spot based on the positional relationship between the glue spot and the soldering ribbon. If the diameter of the glue spot is smaller than the diameter of the soldering ribbon, it means that the glue spot does not exist or the area is too small to fix the soldering ribbon; if the spacing between the glue spot and the soldering ribbon is greater than 0, it means that the glue spot is offset and the soldering ribbon cannot be fixed. Both of the above situations are judged as unqualified glue spots.

[0061] In some embodiments, the first preset value may be set to 1.5% to 2.5%, for example, may be set to 1.5%, 2%, 2.1%, 2.3%, 2.4% or 2.5%.

[0062] In some embodiments, the second preset value may be set to 4% to 6%, for example, 4%, 4.4%, 5%, 5.3%, 5.6% or 6%.

[0063] The settings of the first preset value and the second preset value can be adjusted according to the number of solder strips on the battery cell and the number of glue points required for a single solder strip.

[0064] In a specific example, the first preset value is 2.1%, and the second preset value is 5%. After the battery string enters the second image detection, each battery cell corresponds to a glue point image. If the leakage ratio of all battery cells in the battery string is less than or equal to 2.1%, it is determined that the battery string can enter the next process. Since the leakage ratio of all battery cells is small, the possibility of the soldering strip shifting or falling off in the subsequent process, resulting in the disconnection of the soldering strip and the grid line after lamination, is low. In order to improve the production efficiency of photovoltaic modules and save costs, the battery string can be allowed to enter the next process; if the leakage ratio of at least one battery string in the battery string is greater than or equal to 5%, it means that the possibility of the soldering strip shifting or falling off in the subsequent process is high, and the battery cell needs to be glued, but because the leakage ratio of the battery cell is relatively large, it needs to be repaired. It takes a long time to refill the glue. After entering the refilling process, other cells in the battery string need to wait for refilling at the same time, which may easily lead to a decrease in the manufacturing efficiency of the photovoltaic module. Therefore, sending the battery cell to the rework process can reduce the number of battery strings waiting in the refilling process and improve the manufacturing efficiency of the photovoltaic module. If the omission ratio of all battery cells in the battery string is less than 5%, but the omission ratio of at least one battery cell is greater than 2.1%, it is judged that the battery cell needs to be refilled. Since the omission is relatively small, the time required for refilling is shorter. Therefore, the waiting time of a single battery string in the refilling process is shorter. Sending the battery string to the refilling process can make the battery cells with omission problems meet the requirements after refilling in a faster way, so that the battery string can enter the next process faster.

[0065] In some embodiments, if at least one battery cell in a battery string does not meet a preset condition, the battery string is sent to a rework process including: cutting the battery cells in the battery string that do not meet the preset condition, connecting the remaining battery cells in the battery string in series to form a first reorganized battery string; and performing a second image inspection on the first reorganized battery string.

[0066] That is, after the battery strings that do not meet the preset conditions are cut, the other battery cells that meet the preset conditions are reconnected in series to form a new first reorganized battery string, and then the first reorganized battery string is sent to the next process for the second image inspection. Since the battery cells in the first reorganized battery string are all battery cells that meet the preset conditions, the first reorganized battery string is directly sent to the next process for the second image inspection after the reorganization, which can improve the repair efficiency of the battery string and save the time that the battery cells that meet the preset conditions need to wait for the repair of the battery strings that do not meet the preset conditions in the group of battery strings.

[0067] It should be noted that the battery cells in the first reorganized battery string can come from different battery strings. Since the battery cells that do not meet the preset conditions in the battery string are cut out, the number of remaining battery cells is less than the total number of battery cells required in a single battery string. Therefore, the first reorganized battery string can be formed by re-connecting the battery cells that meet the preset conditions in multiple cut battery strings.

[0068] In some embodiments, if the leakage ratio of at least one cell in the cell string is greater than a first preset value, and the leakage ratios of all cells in the cell string are less than a second preset value, before sending the cells to the glue repair process, it also includes: obtaining the total number of cells in the cell string whose leakage ratio is greater than the first preset value, if the total number of cells whose leakage ratio is greater than the first preset value is greater than or equal to 1 / 2 of the total number of cells in the cell string, then sending the cell string to the repair process; if the total number of cells whose leakage ratio is greater than the first preset value is less than 1 / 2 of the total number of cells in the cell string, then sending the cell string to the glue repair process. When the number of cells in the cell string that need to be glued is large, it is also easy to cause a large number of cell strings waiting for glue repair to pile up in the glue repair process. Therefore, further judging whether the cell string should enter the glue repair process or the repair process according to the number of cells in the cell string that need to be glued can help further improve the manufacturing efficiency of photovoltaic modules.

[0069] In some embodiments, if the leakage printing ratio of at least one battery cell in the battery string is greater than or equal to the second preset value, sending the battery string to the rework process includes: cutting the battery cells in the battery string whose leakage printing ratio is greater than or equal to the second preset value, and connecting the remaining battery cells in the battery string in series to form a second reorganized battery string; if the leakage printing ratios of all battery cells in the second reorganized battery string are less than or equal to the first preset value, sending the second reorganized battery string to the next process; if the leakage printing ratio of at least one battery cell in the second reorganized battery string is greater than the first preset value, and the leakage printing ratios of all battery cells in the second reorganized battery string are less than the second preset value, sending the second reorganized battery string to the glue filling process.

[0070] That is, if the leakage ratio of at least one battery cell in the battery string is greater than or equal to the second preset value, the battery cells in the battery string with a leakage ratio greater than or equal to the second preset value are cut, and the battery cells in the battery string with a leakage ratio less than the second preset value are reconnected in series to form a new second reorganized battery string, and then the relationship between the leakage ratios of all battery cells in the second reorganized battery string and the first preset value is re-determined. Since the battery cells in the battery string with a leakage ratio greater than or equal to the second preset value have been cut, the leakage ratios of all battery cells in the second reorganized battery string are less than the second preset value. If the leakage ratios of all battery cells in the second reorganized battery string are less than the first preset value, it is determined that the second reorganized battery string does not need to be glued and can be allowed to enter the next process; if the leakage ratio of at least one battery cell in the second reorganized battery string is greater than the first preset value, it is determined that the second reorganized battery string needs to be glued. In this way, after the battery cells with relatively low leakage ratios are assembled into a second reorganized battery string in the repair process, the first preset value is combined to determine whether the second reorganized battery string should enter the glue filling process or the next process, which can improve the repair efficiency of the battery string and save the repair time of the battery cells with relatively low leakage ratios waiting for the battery cells with relatively high leakage ratios in the battery string.

[0071] It should be noted that the battery cells in the second reorganized battery string can come from different battery strings. Since the battery cells with a leakage ratio greater than or equal to the second preset value in the battery string are cut out, the number of remaining battery cells is less than the total number of battery cells required in a single battery string. Therefore, the second reorganized battery string can be formed by re-connecting battery cells with a leakage ratio less than the second preset value in multiple cut battery strings.

[0072] In some embodiments, after cutting the battery cells with a leakage ratio greater than or equal to the second preset value in the battery string, the method further includes: connecting the cut battery cells with a leakage ratio greater than or equal to the second preset value in series to form a third reorganized battery string; and sending the third reorganized battery string to a glue filling process. Although all battery cells in the third reorganized battery string require a relatively long time for glue filling, for all battery strings that need to wait in the glue filling process, if the battery string with a relatively long glue filling time is only the third reorganized battery string, the overall working efficiency of the glue filling process can still be improved compared to when all battery strings require a relatively long glue filling time, thereby facilitating the improvement of the overall manufacturing efficiency of the photovoltaic module process.

[0073] It should be noted that the battery cells in the third reorganized battery string can be formed by reconnecting battery cells in a plurality of trimmed battery strings whose printing leakage ratio is greater than or equal to the second preset value, so that the total number of battery cells in the third reorganized battery string meets the total number of battery cells required in a single battery string.

[0074] Figure 4A flowchart corresponding to another photovoltaic module detection method provided in an embodiment of the present application.

[0075] refer to Figure 4 In some embodiments, if the missed printing ratios of all battery cells in the battery string are less than or equal to a first preset value, sending the battery string to the next process includes: obtaining the glue deficiency ratio corresponding to each solder strip according to the glue dot image, and the glue deficiency ratio is the ratio of the number of unqualified glue points corresponding to each solder strip to the total number of preset glue point positions corresponding to the solder strip.

[0076] If the glue shortage ratio is less than or equal to the third preset value (corresponding to Figure 4 If the condition 4 is met in the above, the battery string will be sent to the next process; if the glue shortage ratio is greater than the third preset value (corresponding to Figure 4 If the battery string meets condition 5, the battery string will be sent to the glue filling process.

[0077] Regardless of whether the two polarity grid lines on the battery cell are respectively located on the two sides of the battery cell or the two polarity grid lines on the battery cell are located on the same side surface of the battery cell, if the glue deficiency ratio corresponding to any welding strip is less than or equal to the third preset value, the battery string can be sent to the next process; if the glue deficiency ratio corresponding to any welding strip is greater than the third preset value, the battery string needs to be sent to the glue filling process.

[0078] That is to say, when the missing printing ratios corresponding to all the cells in the battery string are less than or equal to the first preset value, it is also necessary to determine whether the number of glue points corresponding to each welding strip in the battery string meets the requirements. When the glue shortage ratios corresponding to each welding strip are less than the third preset value, it can further ensure that the battery string will not have problems with welding strip offset or falling off during the subsequent process, which is beneficial to improving the manufacturing yield of photovoltaic modules. Since the glue shortage ratio of a single welding strip exceeds the third preset value, but the missing printing ratio corresponding to the battery cell is less than the first preset value, the battery string needs a shorter time to be glued, and will not cause a large number of battery strings to accumulate in the glue filling process. Therefore, first judge the overall missing printing ratio of the battery cell, and then judge the glue shortage ratio corresponding to a single welding strip, which is beneficial to improving the manufacturing efficiency of photovoltaic modules.

[0079] In some embodiments, if the glue shortage ratio is greater than the third preset value, before sending the battery string to the glue repair process, it also includes: obtaining the total number of battery cells corresponding to the solder strips with a glue shortage ratio greater than the third preset value in the battery string, if the total number of battery cells corresponding to the solder strips with a glue shortage ratio greater than the third preset value is greater than or equal to 1 / 2 of the total number of battery cells in the battery string, then sending the battery string to the repair process; if the total number of battery cells corresponding to the solder strips with a glue shortage ratio greater than the third preset value is less than 1 / 2 of the total number of battery cells in the battery string, then sending the battery string to the glue repair process. Since the number of battery cells or solder strips that need to be repaired in the battery string is large, it is also easy to cause a large number of battery strings waiting for glue repair to accumulate in the glue repair process. Therefore, further judging whether the battery string should enter the glue repair process or the repair process based on the number of battery cells that need to be repaired in the battery string can help further improve the manufacturing efficiency of photovoltaic modules.

[0080] In some embodiments, the third preset value can be set to 1.5% to 2.5%, for example, 1.5%, 1.6%, 1.8%, 2%, 2.2% or 2.5%, etc. The third preset value can be adjusted according to the length of the solder strip and the position where the glue point can be set on the battery cell.

[0081] In the detection method of photovoltaic modules provided in the embodiment of the present application, the battery cells are connected by welding strips, and the welding strips are fixed on the battery cells by multiple glue points to form a battery string without a main grid structure. The main grid structure is conducive to reducing the cost of silver paste, reducing shading loss, shortening the current transmission path, reducing the series resistance, and improving the power of photovoltaic modules. First, the battery string is subjected to a first image detection, and it is determined whether each battery cell in the battery string meets the preset requirements according to the result of the first image detection. If at least one battery cell does not meet the preset requirements, the battery string is sent to the rework process; if all battery cells meet the preset requirements, the battery string is sent to the next process. It is judged in advance that the battery cells in the battery string do not meet the preset conditions or have defects, and the battery strings that do not meet the preset conditions are sent to the rework process, which can avoid the problem of increased time and cost caused by the defective battery cells entering the subsequent process and then rework. Then, the battery string is subjected to a second image detection to obtain the glue point image of each battery cell in the battery string, and the corresponding leakage ratio of each battery cell is obtained according to the glue point image, and the battery string is judged based on the leakage ratio to which process it will be sent. For example, if the leakage ratio of all cells in the battery string is less than or equal to the first preset value, the battery string is sent to the next process; if the leakage ratio of at least one cell in the battery string is greater than or equal to the second preset value, the battery string is sent to the repair process; if the leakage ratio of all cells in the battery string is less than the second preset value, and the leakage ratio of at least one cell is greater than the first preset value, the cell is sent to the glue filling process. When the leakage ratio corresponding to the cell is greater than the first preset value, it means that the cell needs to be glued, but when the leakage ratio of the cell is greater than the second preset value, it means that the cell needs to be glued a lot, so the glue filling time of a single cell is relatively long. If all the cell strings that need to be glued are waiting in the glue filling process, a large number of cell strings will be piled up in the glue filling process, which will further reduce the manufacturing efficiency of photovoltaic modules. Therefore, the battery strings corresponding to the battery cells whose leakage printing ratio is between the first preset value and the second preset value are sent to the glue filling process, and the battery strings corresponding to the battery cells whose leakage printing ratio is greater than the second preset value are sent to the repair process. Different processes can be selected for battery strings in different conditions to avoid the problem of a large number of battery strings queuing in the glue filling process, thereby improving the production efficiency of photovoltaic modules and saving production costs.

[0082] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present application. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application, and therefore the scope of protection of the present application shall be subject to the scope defined in the claims.

Claims

1. A method for detecting a photovoltaic module, characterized in that: include: Laying a welding tape on the surface of a battery cell, and fixing the welding tape on the battery cell through a plurality of glue points, and connecting a plurality of battery cells through the welding tape to form a battery string; Performing a first image detection on the battery string to obtain a detection image of each battery cell in the battery string; Judging whether each of the battery cells in the battery string meets a preset condition according to the detection image, if all of the battery cells in the battery string meet the preset condition, the battery string is sent to the next process; if at least one of the battery cells in the battery string does not meet the preset condition, the battery string is sent to a repair process; Performing a second image detection on the battery string to obtain a glue point image of each battery cell in the battery string; Obtaining a missing print ratio corresponding to each of the battery cells according to the glue dot image, wherein the missing print ratio is expressed as a ratio of the number of unqualified glue dots on each of the battery cells to the total number of preset glue dot positions on the battery cell; If the missing printing ratios of all the battery cells in the battery string are less than or equal to a first preset value, the battery string is sent to the next process; If the missing printing ratio of at least one of the battery cells in the battery string is greater than the first preset value, and the missing printing ratios of all the battery cells in the battery string are less than the second preset value, the battery string is sent to the glue filling process; If the missing printing ratio of at least one of the battery cells in the battery string is greater than or equal to the second preset value, the battery string is sent to the rework process.

2. The photovoltaic module detection method according to claim 1, characterized in that: If the missing printing ratios of all the battery cells in the battery string are less than or equal to the first preset value, sending the battery string to the next process includes: obtaining the glue shortage ratio corresponding to each solder strip according to the glue spot image, wherein the glue shortage ratio is the ratio of the number of unqualified glue spots corresponding to each solder strip to the total number of preset glue spot positions corresponding to the solder strip; If the glue deficiency ratio is less than or equal to a third preset value, sending the battery string to the next process; If the glue deficiency ratio is greater than the third preset value, the battery string is sent to the glue filling process.

3. The photovoltaic module detection method according to claim 2, characterized in that: The third preset value is 1.5% to 2.5%.

4. The photovoltaic module detection method according to claim 1, characterized in that: If at least one of the battery cells in the battery string does not meet the preset condition, the battery string is sent to a rework process including: Cutting the battery cells in the battery string that do not meet the preset condition, and connecting the remaining battery cells in the battery string in series to form a first reorganized battery string; The second image detection is performed on the first recombinant battery string.

5. The photovoltaic module detection method according to claim 1, characterized in that: If the missing printing ratio of at least one of the battery cells in the battery string is greater than or equal to the second preset value, sending the battery string to the rework process includes: Cutting the battery cells in the battery string whose leakage ratio is greater than or equal to the second preset value, and connecting the remaining battery cells in the battery string in series to form a second reorganized battery string; If the missed printing ratios of all the battery cells in the second reorganized battery string are less than or equal to the first preset value, the second reorganized battery string is sent to the next process; If the missing printing ratio of at least one battery cell in the second reorganized battery string is greater than the first preset value, and the missing printing ratios of all the battery cells in the second reorganized battery string are less than the second preset value, the second reorganized battery string is sent to the glue filling process.

6. The photovoltaic module detection method according to claim 5, characterized in that: After cutting the battery cells in the battery string whose missing printing ratio is greater than or equal to the second preset value, the method further includes: connecting in series a plurality of the cut battery cells whose missing printing ratio is greater than or equal to the second preset value to form a third reorganized battery string; and sending the third reorganized battery string to the glue filling process.

7. The photovoltaic module detection method according to claim 1, characterized in that: The soldering tape is fixed to the battery cell by means of the plurality of glue spots, including: the glue spots are located on the surface of the soldering tape away from the battery cell; and / or the glue spots are located between the soldering tape and the battery cell.

8. The photovoltaic module detection method according to claim 7, characterized in that: If the glue spot is located on the surface of the soldering ribbon away from the battery cell, the unqualified glue spot includes the following situation: there is no glue spot on the surface of the soldering ribbon.

9. The photovoltaic module detection method according to claim 7, characterized in that: If the glue spot is located between the soldering ribbon and the battery cell, the unqualified glue spot includes the following situations: the diameter of the glue spot is smaller than the diameter of the soldering ribbon; or the distance between the glue spot and the soldering ribbon is greater than 0.

10. The photovoltaic module detection method according to claim 1, characterized in that: The first preset value is 1.5% to 2.5%; The second preset value is 4% to 6%.

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