Visual alignment-based partial contact pre-fixing method for photovoltaic module gap reflective film

Abstract

This invention relates to a method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment, belonging to the field of photovoltaic module manufacturing technology. The method includes: acquiring an image of the cell array; identifying the gap boundaries and gap widths of adjacent cells at each detection position along the gap extension direction; determining the offset direction and amount of the gap relative to a predetermined laying position; determining the reflective film laying position based on the gap boundaries and gap width; laying the reflective film in the corresponding gap area; and determining the local pressing position of the flexible heating strip in the width direction of the reflective film based on the offset direction, forming spaced local pre-fixed areas; when the offset direction changes, interrupting the local pressing, and re-forming the local pre-fixed area after crossing the change position, creating an unpressed release section between the two local pre-fixed areas to isolate lateral traction transmission, reduce the possibility of film strip lateral shift, wrinkling, or local lifting, and improve the consistency and reliability of the reflective film pre-fixation state.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module manufacturing technology, specifically to a method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment. Background Technology

[0002] In existing technologies, to improve the utilization rate of incident light in the gaps between solar cells and between solar strings in photovoltaic modules, reflective films are typically placed at the corresponding gap positions. This allows light incident on the gap area to be reflected and re-enter the light-receiving area of ​​the solar cell, thereby reducing ineffective transmission or light leakage. As module designs tend to be larger, with narrower spacing and higher density, the relative positional accuracy between the reflective film and the gaps between solar cells directly affects the coverage of the film strip over the gaps and the subsequent lamination quality. Chinese patent CN115266754B discloses a visual inspection method for photovoltaic modules. This method uses upper and lower light sources in conjunction with an image acquisition device to obtain the coordinate information of the film strip end, solar cell edge, and gaps between cells or between strings. It then calculates the overlap distance between the film strip and the solar cell to identify modules with insufficient overlap or incomplete coverage of the gaps, resulting in light leakage. This solution demonstrates that visual methods can be used to determine the relative positional state of the film strip and the gaps, but its focus is on post-application inspection and screening. It is difficult to directly address the problems of local offset and stress accumulation of the film strip caused by deviations in the actual arrangement of solar cells during the installation process.

[0003] Existing technologies also disclose automated laying equipment for reflective film gaps. Chinese Patent Publication No. CN117727818B discloses an automated film-applying device for reflective film gaps in photovoltaic cell modules. This device uses a lifting conveyor, a horizontal moving device, a lifting film-applying device, and a feeding device to achieve continuous feeding, cutting, and hot-pressing of the reflective film. A correction mechanism is used to adjust the position of the cell modules, thereby improving film-applying production efficiency. While this type of solution can achieve automated conveying and hot-pressing of the reflective film, in actual production, the gaps formed by adjacent cells do not always maintain an ideal straight line and constant width. Affected by cell layout, welding, handling, and previous positioning errors, the same gap may shift towards different cell boundaries, narrow locally, or change direction along its extension direction. If the reflective film is still pressed and fixed continuously or symmetrically, the fixed area will exert lateral traction on the subsequently unfixed area, causing cumulative displacement, wrinkling, lifting, or insufficient coverage of the film strip at narrow gaps or shifting positions.

[0004] Therefore, while existing technologies possess capabilities for visual inspection, component alignment, automatic film laying, and hot-pressing, they still fall short in their ability to identify gap boundaries, widths, and offset trends at different detection positions in real time along the gap extension direction, select localized pressing sides in the reflective film width direction based on the offset direction, actively interrupt pressing at the point of offset direction change, and set up unpressed release sections to isolate the lateral traction transfer between the pre-fixed areas. Especially when local gap width and offset direction changes occur simultaneously, further improvements are needed to maintain the basic laying position of the reflective film while releasing localized lateral constraints, avoiding positional offset caused by continuous hot pressing, and providing a stable initial positioning state for subsequent overall lamination. Summary of the Invention

[0005] The purpose of this invention is to provide a method for local contact pre-fixation of reflective film in the gaps of photovoltaic modules based on visual alignment, thereby solving some of the drawbacks and shortcomings pointed out in the background art.

[0006] The present invention adopts the following technical solution to solve the above-mentioned technical problems:

[0007] The process involves acquiring an image of the battery cell array, identifying the gap boundaries and widths of adjacent battery cells at each detection position along the gap extension direction, and determining the offset direction and amount of the gap relative to the predetermined laying position. Based on the gap boundaries and widths, the reflective film laying position is determined, and the reflective film is laid in the corresponding gap area. The local pressing position of the flexible heating belt in the width direction of the reflective film is determined according to the offset direction, so that the flexible heating belt forms spaced local pre-fixed areas along the gap extension direction. When the offset directions of adjacent detection positions are consistent, a local pre-fixed area is formed along the gap extension direction. When the offset direction changes from towards one side of the battery cell boundary to towards the other side of the battery cell boundary, the local pressing is interrupted, and a new local pre-fixed area is formed after crossing the offset direction change position, creating an unpressed release section between the two local pre-fixed areas to isolate the lateral traction transmission of the reflective film by the local pre-fixed areas.

[0008] Furthermore, the local pre-fixed area is formed by multiple pressing. The flexible heating tape first forms an initial pressing area on the side of the reflective film away from the cell boundary pointed to by the offset direction in the width direction of the reflective film. After the adjacent local pre-fixed area is formed, the flexible heating tape presses again in the initial pressing area, so that the side of the reflective film close to the cell boundary remains unpressed.

[0009] Furthermore, the local pre-fixed areas at both ends of the unpressed release section are located on different sides of the reflective film width direction, and are located on the side away from the cell boundary pointed to by the corresponding offset direction, so that the local pre-fixed areas at both ends of the unpressed release section are misaligned in the reflective film width direction.

[0010] Furthermore, when the gap width at the offset direction change position is less than the gap width of the adjacent areas on both sides of the change position, the flexible heating band crosses the offset direction change position and forms local pre-fixed areas at the starting positions where the gap width on both sides of the change position changes from decreasing to increasing, so that the unpressed release section covers the area where the gap width decreases.

[0011] Furthermore, the gap offset on both sides of the unpressed release section is determined as the first offset and the second offset. The misalignment distance of the two local pre-fixed areas in the width direction of the reflective film is determined based on the difference between the first offset and the second offset. The local pre-fixed area corresponding to the higher offset is offset to the side away from the battery cell boundary pointed to by the corresponding offset direction, so as to reduce the lateral traction difference at both ends of the unpressed release section.

[0012] Furthermore, the local pre-fixed areas at both ends of the unpressed release section are formed sequentially in ascending order of the corresponding gap offset values. Before forming the next local pre-fixed area, the end of the reflective film close to the next local pre-fixed area is kept unpressed in the width direction, and the position constraint of the reflective film is completed after the next local pre-fixed area is formed.

[0013] Furthermore, the local pre-fixed areas at both ends of the unpressed release section are staggered along the gap extension direction, so that the adjacent ends of the two local pre-fixed areas have a gap along the gap extension direction, and the local pre-fixed areas at both ends of the unpressed release section are maintained in the width direction of the reflective film, so that the reflective film forms a lateral constraint staggered along the gap extension direction at the position where the offset direction changes.

[0014] Furthermore, the unpressed release section covers the region where the gap width decreases along the gap extension direction and extends to the position where the gap width is restored to the width corresponding to the starting position of the region where the gap width decreases, so that the local pre-fixed areas at both ends of the unpressed release section are located at both ends of the region where the gap width decreases, so that the lateral constraint generated by the local narrow gap is released within the unpressed release section.

[0015] Furthermore, the local pre-fixed areas at both ends of the unpressed release section are formed sequentially. First, a previous local pre-fixed area is formed at one end of the gap width reduction area. Then, the reflective film is made to cross the gap width reduction area along the gap extension direction and a subsequent local pre-fixed area is formed at the other end to avoid the reflective film being pulled in opposite directions by pressure at both ends of the local narrow gap.

[0016] Furthermore, the subsequent local pre-fixed area is formed after the gap width is restored and reaches the gap width corresponding to the previous local pre-fixed area, so that the unpressed release section crosses the area where the gap width is reduced, and the previous local pre-fixed area forms a unilateral constraint on the reflective film until the gap width reaches the gap width corresponding to the previous local pre-fixed area.

[0017] This invention acquires images of the battery cell array, identifies the gap boundaries and gap widths of adjacent battery cells at each detection position along the gap extension direction, and determines the offset direction and amount of the gap relative to the predetermined laying position. This allows the laying position of the reflective film to be determined based on the actual gap state. Compared to laying the film only according to a preset trajectory, this invention can improve the correspondence accuracy between the reflective film and the actual gap, and reduce the risk of insufficient coverage or excessive overlap with the battery cells caused by deviations in the battery cell arrangement.

[0018] The present invention determines the local pressing position of the flexible heating belt in the width direction of the reflective film based on the gap offset direction, and forms a locally pre-fixed area arranged at intervals along the gap extension direction, so that the reflective film retains the unpressed area while obtaining the necessary positional constraint, thereby reducing the lateral traction and thermal effect on the film body caused by continuous pressing, which is beneficial to maintaining the positional adjustability and morphological stability of the reflective film during the laying process.

[0019] When the offset direction of adjacent detection positions changes from one side to the other, the present invention interrupts the local pressing and re-forms the local pre-fixed area after crossing the position of the offset direction change, so that an unpressed release section is formed between the two local pre-fixed areas. This can isolate the lateral traction transmission between the front and rear local pre-fixed areas, reduce the lateral shift, wrinkling or local lifting of the film strip caused by traction accumulation, and help improve the consistency and reliability of the pre-fixed state of the reflective film before subsequent lamination. Attached Figure Description

[0020] Figure 1 This is a flowchart of the process for partial contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment, according to the present invention.

[0021] Figure 2 This is a diagram showing the visual detection of gaps and determination of directional offset in Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic diagram of the partially covered and uncovered areas of the flexible heating strip in Embodiment 1 of the present invention.

[0023] Figure 4 This is a diagram showing the misalignment of the uncompressed release section and the local pre-fixed area at the offset direction change point in Embodiment 1 of the present invention.

[0024] Figure 5 This is a diagram showing the change in gap width and the degree of relative reduction in Embodiment 2 of the present invention.

[0025] Figure 6 This is a diagram showing the relationship between the local narrow gap and the uncompressed release section in Embodiment 2 of the present invention.

[0026] Figure 7 This is a diagram illustrating the process of localized narrow gap crossing and sequential pre-fixing at both ends in Embodiment 2 of the present invention. Detailed Implementation

[0027] As attached Figure 1 As shown, in the specific implementation process, an image of the solar cell array in the photovoltaic module is first acquired, and the gap formed between adjacent solar cells is used as the identification object. The image can cover the gap area corresponding to the reflective film to be laid and can identify the boundary of the adjacent solar cells facing the gap. Multiple detection positions are set along the gap extension direction, and the solar cell boundary at each detection position is identified. The gap range at the corresponding position is determined by the boundary of the adjacent solar cells, and the corresponding gap width is obtained. Specifically, at the same detection position, the area between the two opposite boundaries of the adjacent solar cells is determined as the gap range, and the middle position of this gap range in the width direction of the reflective film is taken as the gap position corresponding to the detection position. The predetermined laying position is the reflective film laying reference position predetermined according to the predetermined arrangement relationship of the solar cells in the photovoltaic module. The identified gap position is compared with the predetermined reflective film laying position, and the offset direction corresponding to each detection position is determined according to the positional relationship between the two in the width direction of the reflective film. At the same time, the offset amount of the gap relative to the predetermined laying position is determined. Specifically, when the gap position moves to one side of the reflective film width direction relative to the predetermined laying position, that side is determined as the offset direction of the corresponding detection position, and the interval between the gap position and the predetermined laying position in the reflective film width direction is taken as the corresponding offset amount. This forms information on the gap boundary, gap width, offset direction, and offset amount distributed along the gap extension direction, providing a positional basis for subsequent reflective film laying and the determination of local pre-fixed positions.

[0028] The actual placement of the reflective film is determined based on the obtained gap boundaries and gap widths, ensuring the film is laid along the gap area between adjacent solar cells. The actual placement position is determined according to the gap range corresponding to each detection position, ensuring the reflective film's extension direction corresponds to the gap extension direction and its width direction is adapted to the corresponding gap range. After the reflective film is laid, the local pressing position of the flexible heating strip in the width direction of the reflective film is determined based on the offset direction corresponding to each detection position. The flexible heating strip is a flexible component capable of adhering to a local surface of the reflective film and heating and pressing the contact position. Its heating temperature, pressing degree, and contact time are designed to create a locally pre-fixed state at the corresponding position that maintains the reflective film's placement without causing significant thermal deformation. The flexible heating strip does not continuously press the reflective film; instead, it locally presses it at predetermined positions along the gap extension direction, creating multiple locally pre-fixed areas spaced apart along the gap extension direction. Each local pre-fixed area is used to constrain the position of the reflective film locally, while leaving uncovered areas of reflective film between adjacent local pre-fixed areas, so that the reflective film still has local adjustment space after pre-fixation is completed.

[0029] The offset direction of each detection position is continuously compared along the gap extension direction. When the offset direction of adjacent detection positions is consistent, a local pre-fixed area is formed according to the offset relationship corresponding to that gap segment, so that the reflective film maintains a local constraint adapted to the gap position in this area. When the offset direction changes from towards one side of the cell boundary to towards the other side of the cell boundary, the area where the offset direction changes between adjacent detection positions is determined as the offset direction change position. At the offset direction change position, the local pressing of the flexible heating band is interrupted, allowing the flexible heating band to cross the change position, and the reflective film is re-pressed locally after the change position. In this way, an unpressed release section is formed between the local pre-fixed areas on both sides of the offset direction change position. This unpressed release section does not directly bear the local pressing constraint formed by the flexible heating band, thereby isolating the continuous lateral traction transmission between the two local pre-fixed areas on the reflective film. This allows the reflective film to adapt to the change in the gap offset direction using the unpressed release section, reducing the possibility of the reflective film position shift caused by the mutual transmission of lateral traction generated by the two local pre-fixed areas.

[0030] In the specific implementation process, the local pre-fixed areas are formed by a staged pressing method. For each local pre-fixed area, after determining the offset direction of the corresponding position of the reflective film, the boundary of the solar cell pointed to by the offset direction is used as a position reference, and the side away from the solar cell boundary in the width direction of the reflective film is selected as the initial pressing position. The flexible heating strip first contacts the initial pressing position, and through local heating and pressing, the reflective film forms an initial pressing area at this position. The initial pressing position is located within the corresponding gap range and maintains an unpressed area on the side near the solar cell boundary, so that the local pressing does not cross the entire width of the reflective film. The initial pressing area is used to initially restrict the position of the reflective film, so that the reflective film maintains a basic laying position during the subsequent formation of adjacent local pre-fixed areas, while avoiding the formation of continuous pressing constraints on the side near the solar cell boundary.

[0031] After forming adjacent local pre-fixed areas along the gap extension direction, the flexible heating band acts again on the initial pressing area, performing re-pressing within the range of the initial pressing area to enhance the pre-fixing effect on the reflective film at that location. During the re-pressing process, the pressing range is not extended to the side closer to the cell boundary, so that the side of the reflective film near the cell boundary remains unpressed. After the re-pressing is completed, the initial pressing area forms a corresponding local pre-fixed area. When re-pressing the same local pre-fixed area, the range of action of the flexible heating band remains within the initial pressing area, aiming to strengthen the local constraint at that location without changing the pre-retained unpressed area. Thus, while obtaining stable positional constraint, the local pre-fixed area can retain an unpressed area in the width direction of the reflective film, giving the reflective film a certain adjustment space when subjected to lateral positional changes or traction from adjacent areas, and reducing the limitation of the local pressing on the lateral displacement capability of the reflective film.

[0032] In the specific implementation process, when the offset direction of the gap changes in the adjacent area along the gap extension direction, local pre-fixed areas are set on both sides of the position where the offset direction changes, and an unpressed release section is retained between the two local pre-fixed areas. The local pre-fixed area at one end of the unpressed release section is set on one side of the width direction of the reflective film, and the local pre-fixed area at the other end is set on the other side of the width direction of the reflective film. The two local pre-fixed areas are respectively arranged away from the cell boundary pointed to by their respective offset directions, thereby creating a misalignment between the local pre-fixed areas at both ends of the unpressed release section in the width direction of the reflective film. The offset of the gap on one side of the unpressed release section relative to the predetermined laying position is determined as the first offset, and the offset of the gap on the other side of the unpressed release section relative to the predetermined laying position is determined as the second offset. The first offset and the second offset are compared, and the misalignment distance between the two local pre-fixed areas in the width direction of the reflective film is determined based on their difference. The greater the difference between the first offset and the second offset, the larger the width misalignment is formed between the two local pre-fixed areas. When one offset value is higher than the other, the local pre-fixed area corresponding to the higher offset value is further offset away from the cell boundary pointed to by the offset direction. When the first offset and the second offset are the same or substantially the same, the two local pre-fixed areas are set according to their respective offset directions, without needing to further increase the offset on one side due to the offset difference. This results in the two local pre-fixed areas being misaligned in the width direction corresponding to the degree of gap offset on both sides. Through this setting, the lateral constraint positions formed by the two ends of the unpressed release section on the reflective film can be adapted to their respective gap offset states, reducing the difference in the degree of lateral traction between the two ends.

[0033] When forming the local pre-fixed areas at both ends of the un-pressed release section, the pressing sequence is determined according to the values ​​of the first offset and the second offset. First, the local pre-fixed area corresponding to the side with the lower offset value is formed, followed by the local pre-fixed area corresponding to the side with the higher offset value. Before the formation of the latter local pre-fixed area, the end of the reflective film closest to this local pre-fixed area remains unpressed in the width direction, allowing this end to adapt to the difference in gap offset between the two sides using the unpressed state. In the unpressed state, the reflective film can be locally laterally adjusted relative to the previously formed local pre-fixed area, so that the position of the reflective film in the latter local pre-fixed area adapts to the actual laying position. Once the reflective film at this position is within the corresponding gap range and remains smoothly laid, the latter local pre-fixed area is formed using a flexible heating strip to complete the positional constraint of the other end of the un-pressed release section. Simultaneously, the local pre-fixed areas at both ends of the un-pressed release section are not only staggered in the width direction of the reflective film but also staggered along the gap extension direction, so that the adjacent ends of the two local pre-fixed areas form a gap in the gap extension direction. Therefore, the two local pre-fixed areas will not form a concentrated lateral constraint at the same position when the offset direction changes. Instead, they will impose positional constraints on the reflective film along the gap extension direction, so that the lateral constraints are established sequentially at different positions as the gap offset direction changes. This allows the reflective film to retain continuous adjustment space in the offset direction change area and reduces the possibility that the lateral traction generated by the two local pre-fixed areas will directly superimpose at the offset direction change position, causing the reflective film to shift, wrinkle, or lift.

[0034] In the specific implementation process, the gap width at the offset direction change position and on both sides is compared along the gap extension direction. When the gap width corresponding to the offset direction change position is less than the gap width of the adjacent areas on both sides of that position, the area where that position is located is determined as the gap width reduction area. The gap width reduction area is composed of the continuously detected gap width reduction portion along the gap extension direction. Its starting position is the position where the gap width begins to decrease relative to the adjacent area, and its other end is the position where the gap width stops decreasing and enters the recovery and increase process. When forming the local pre-fixed area, the flexible heating strip does not continuously press over this gap width reduction area, but crosses the offset direction change position and forms local pre-fixed areas at the corresponding positions on both sides of the change position where the gap width changes from decreasing to increasing. Thus, the unpressed release section formed between the two local pre-fixed areas covers the gap width reduction area. The unpressurized release section is positioned along the gap extension direction. One end extends from the point where the gap width begins to decrease into the area where the gap width decreases, while the other end continues to extend until the gap width recovers to the width corresponding to the starting position of the gap width decrease area. When the gap width does not fully recover to the width corresponding to the starting position during actual testing, the other end of the unpressurized release section is defined as the position where the gap width has changed from decreasing to increasing and reaches the width closest to the starting position. By covering the area corresponding to the local narrow gap with the unpressurized release section, the reflective film is not subject to the continuous pressing constraint formed by the flexible heating band in this area, thus reserving release space for lateral positional changes caused by the local narrow gap.

[0035] When forming the local pre-fixed zones at both ends of the un-pressed release section, the two local pre-fixed zones are formed sequentially. First, a preceding local pre-fixed zone is formed at one end of the area where the gap width decreases, creating a unilateral positional constraint on the reflective film. Then, the reflective film is allowed to cross the area where the gap width decreases along the gap extension direction, maintaining this area in an unpressed state during the crossing, allowing the reflective film to adjust its position within a localized narrow gap. Position adjustment refers to the localized lateral adjustment of the reflective film in the unpressed state based on the gap boundary, gap width, and actual laying position, culminating in the reflective film being positioned within the corresponding gap range and laid smoothly. When the gap width recovers at the other end of the gap width-decreasing area and reaches the gap width corresponding to the position of the preceding local pre-fixed zone, a subsequent local pre-fixed zone is formed using a flexible heating strip. If the gap width has not fully recovered to the same width, a subsequent local pre-fixed zone is formed at the position where the gap width has changed from decreasing to increasing and reaches the position closest to the gap width corresponding to the position of the preceding local pre-fixed zone. Therefore, the unpressed release section completely spans the area where the gap width decreases, and before the formation of the next local pre-fixed area, the previous local pre-fixed area continuously applies unilateral constraint to the reflective film, avoiding simultaneous pressing at both ends of the local narrow gap and thus preventing the reflective film from being pulled in opposite directions. This allows the reflective film to maintain the corresponding lateral adjustment capability within the gap width variation area.

[0036] Example 1:

[0037] This embodiment provides a visual alignment-based method for local contact pre-fixation of reflective film in photovoltaic module gaps. First, an image of the solar cell array in the photovoltaic module is acquired. Using the gaps between adjacent cells as the identification target, multiple detection positions are set along the gap extension direction. The boundaries of adjacent cells facing the gap at each detection position are identified. The gap range and width are determined based on the two side boundaries, and the actual gap center position at each detection position is determined. Subsequently, the actual gap center position is compared with a pre-determined predetermined reflective film laying reference position to obtain the offset direction and offset amount distributed along the gap extension direction. Based on this, the actual laying position of the reflective film and the local pressing position of the flexible heating strip in the width direction of the reflective film are determined.

[0038] During visual recognition, lateral position coordinates are established along the width of the reflective film. After identifying the boundaries of two adjacent solar cells facing the gap at the same detection location, the midpoint between the two boundaries is determined as the actual gap center position. The predetermined laying reference position is determined based on the predetermined arrangement of the solar cells in the photovoltaic module and the predetermined laying path of the reflective film. In this embodiment, the first side of the reflective film width direction is defined as the positive direction, and the second side opposite to the first side is defined as the negative direction, so that the offset results obtained from different detection locations along the gap extension direction adopt a unified directional reference. Figure 2The correspondence between the detection positions, the actual gap center position, and the predetermined laying reference position, which are continuously set along the gap extension direction, is illustrated. When the actual gap center position is above the predetermined laying reference position, it corresponds to the first side offset; when it is below the predetermined laying reference position, it corresponds to the second side offset. A section in which the offset direction changes is formed between the second detection position and the third detection position.

[0039] The directional offset of the i-th detection position is determined by the following formula:

[0040]

[0041] In the formula, The directional offset of the actual gap center position at the i-th detection position relative to the predetermined laying reference position is expressed in mm. The actual gap center position identified at the i-th detection position, in mm; This is the predetermined laying reference position corresponding to the i-th detection position, in mm. Since... and Using the same lateral position coordinates, the difference between the two can directly characterize the direction and distance of movement of the actual gap center position relative to the predetermined laying reference position. When the value is greater than 0, it indicates that the actual gap center position is offset towards the first side in the width direction of the reflective film; when... When the value is less than 0, it indicates that the actual gap center position is offset to the second side; The absolute value is the magnitude of the offset at the corresponding detection position. Therefore, it is possible to determine the magnitude of the offset based on the position. The sign determines the direction of the offset, and its absolute value determines the degree of offset.

[0042] To illustrate the above visual recognition and calculation process, this embodiment uses a set of example detection data. This set of data is used to illustrate the implementation process of the method and does not represent the actual measurement results on a production line, nor does it constitute a limitation on the parameter range of this method. Four detection positions are selected, continuously distributed along the gap extension direction, and each detection position corresponds to a predetermined laying reference position. Both are 20.000 mm, and the actual gap center position is obtained by visual recognition. The values ​​are 20.120 mm, 20.180 mm, 19.860 mm, and 19.790 mm, respectively. Substituting these data into the formula for calculating directional offset, the four detection positions correspond to... The values ​​are 0.120 mm, 0.180 mm, -0.140 mm, and -0.210 mm, respectively. Specifically, 20.120 mm minus 20.000 mm equals 0.120 mm, 20.180 mm minus 20.000 mm equals 0.180 mm, 19.860 mm minus 20.000 mm equals -0.140 mm, and 19.790 mm minus 20.000 mm equals -0.210 mm. Therefore, Figure 2 The gaps at the first two detection positions are shifted to the first side, and the gaps at the last two detection positions are shifted to the second side. There is a change in the direction of shift between the second and third detection positions. Figure 2 The bidirectional dimension arrows are used to indicate the directional offset distance of the actual gap center position at each detection location relative to the predetermined laying reference position, so that the offset direction, offset value, and offset direction change position can be mapped to the same visual inspection result.

[0043] The actual placement of the reflective film is determined based on the gap boundaries and gap widths obtained at each detection location, allowing the reflective film to extend along the gap area between adjacent solar cells. After determining the offset direction of each detection location, the flexible heating belt selects a side away from the solar cell boundary indicated by the offset direction in the width direction of the reflective film for the first local pressing. When the gap between the first and second detection locations shifts towards the first side, the flexible heating belt selects a side away from the solar cell boundary on the first side to form an initial pressing area; when the gap between the third and fourth detection locations shifts towards the second side, the flexible heating belt selects a side away from the solar cell boundary on the second side to form an initial pressing area, thereby keeping the side of the reflective film close to the corresponding solar cell boundary unpressed and preserving local adjustment space for the reflective film in the width direction.

[0044] Figure 3 The diagram further illustrates the phased localized pressing relationship of the flexible heating band along the width of the reflective film. Taking the case where the gap is offset towards the first side as an example, the flexible heating band is positioned on the side of the reflective film away from the boundary of the first-side battery cell, forming a localized pressing area below it, while the side closer to the boundary of the first-side battery cell retains an unpressed area. After the first pressing, an initial pressing area is formed, used to establish preliminary positional constraints on the reflective film; after the formation of adjacent localized pre-fixed areas, the flexible heating band returns to the initial pressing area to perform a second pressing. Figure 3 The flexible heating zone and localized pressing area corresponding to the first and second pressing are basically consistent along the width direction of the reflective film. This is used to indicate that the second pressing enhances the pre-fixing effect within the original initial pressing range, rather than expanding the pressing range to the unpressed area.

[0045] After the initial bonding area is formed, the flexible heating band continues to form adjacent local pre-fixed areas at predetermined positions along the gap extension direction. Once the adjacent local pre-fixed areas are formed, the flexible heating band acts again on the already formed initial bonding area, performing a second bonding within the original range of the initial bonding area to enhance the pre-fixation effect on the reflective film at that location. The second bonding does not extend towards the side closest to the corresponding cell boundary, ensuring that the unbonded area retained after the first bonding remains unbonded. The first bonding establishes initial positional constraints on the reflective film, while the second bonding enhances local constraints at the same location. Both bonding processes ensure that the reflective film area near the corresponding cell boundary is not continuously bonded, thereby reducing the limitation of local fixation on the reflective film's lateral positional adjustment capability.

[0046] Continuously compare adjacent detection positions along the gap extension direction When adjacent detection positions When the symbols are the same, it indicates that the gap offset direction of the corresponding areas is consistent, and the flexible heating bands continue to form locally pre-fixed areas arranged at intervals according to the corresponding offset relationship. When adjacent detection positions When the sign changes from positive to negative or from negative to positive, it indicates a change in the direction of gap offset. Taking the detection data from the aforementioned implementation example as an example, the second detection position... The value is 0.180 mm, at the third detection position. The offset direction change zone is determined between the second and third detection positions, with a value of -0.140 mm. The flexible heating band interrupts local pressing in this zone, and after crossing the offset direction change zone, re-implements local pressing, creating an unpressurized release section between the pre-fixed local areas on both sides of the change zone. This unpressurized release section does not directly bear the local pressing constraint formed by the flexible heating band, allowing the reflective film to adapt to changes in the gap offset direction using the unpressurized state.

[0047] For the local pre-fixed areas at both ends of the unpressurized release section, the directional offset of the corresponding detection areas on both sides is obtained respectively. and The absolute values ​​of these two values ​​represent the magnitude of the offset of the gaps on both sides. Since the width-direction misalignment of the local pre-fixed area is used to accommodate the difference in the degree of gap offset on both sides, rather than to represent the total lateral positional change of the gap as it moves from the first side to the second side, the misalignment distance M is determined according to the difference in the magnitude of the offsets on both sides:

[0048]

[0049] In the formula, M is the additional misalignment distance in the width direction of the local pre-fixed area at both ends of the unpressurized release section, determined according to the difference in the degree of offset on both sides, and the unit is mm; The directional offset of the detection area corresponding to the first side of the uncompressed release section is expressed in mm. The directional offset of the detection area corresponding to the second side of the uncompressed release section is expressed in mm. and The absolute values ​​of M represent the magnitude of the offset of the gaps on both sides of the release section. First, obtain the absolute values ​​of the directional offsets on both sides, then calculate the difference between them and take its absolute value. This allows M to reflect the actual difference in the degree of offset between the two sides. When the offsets on both sides are the same, M is 0, indicating that there is no need to further increase the additional offset of the local pre-fixed area on one side due to the difference in the degree of offset. When the offsets on both sides are different, the local pre-fixed area corresponding to the side with the higher offset is further offset away from the boundary of the solar cell pointed to by the corresponding offset direction. The additional offset distance is determined based on M.

[0050] Using the aforementioned second and third detection positions as the corresponding detection positions on both sides of the uncompressed release section, take... It is 0.180 mm. The value is -0.140 mm. Substituting this into the above calculation formula:

[0051]

[0052] This results in a difference of 0.040 mm in the degree of gap offset between the two sides. Since the offset corresponding to the second detection position is 0.180 mm, which is higher than the offset corresponding to the third detection position of 0.140 mm, the local pre-fixed area corresponding to the second detection position is further offset by 0.040 mm away from the cell boundary pointed to by the offset direction on that side. Figure 4 The local pre-fixation relationship of the offset direction change area was expanded, wherein the unpressed release section is set between two local pre-fixation areas and spans the offset direction change position; the local pre-fixation area on one side of the release section is located on the first side of the width direction of the reflective film, and the local pre-fixation area on the other side is located on the second side, thus forming a basic width direction misalignment relationship. Figure 4 The M indicated in the figure represents the additional misalignment adjustment based on the difference in the degree of offset on both sides. It is not the total geometric distance between the centers of the two local pre-fixed areas on the drawing. The area size and distance in the figure are used to illustrate the positional relationship and are not drawn to the actual scale.

[0053] When forming the local pre-fixed areas at both ends of the un-covered release section, they are formed sequentially in order of increasing corresponding gap offset. For the test data in the above implementation example, a first local pre-fixed area is formed on one side of the third test position with an offset of 0.140 mm, thus initially constraining the reflective film at that position. Before forming the second local pre-fixed area on one side of the second test position with an offset of 0.180 mm, the end of the reflective film closest to the second local pre-fixed area remains un-covered in the width direction, allowing for local lateral adjustment relative to the already formed first local pre-fixed area. Once the reflective film has formed a laying state adapted to the actual gap position within the corresponding gap range, a second local pre-fixed area is formed using a flexible heating strip, thereby completing the positional constraint on the other end of the un-covered release section. Figure 4 The first and second local pre-fixed areas are respectively set at different ends of the unpressed release section and located on different sides along the width direction of the reflective film, so as to reflect that the local constraint position changes when the offset direction changes from one side to the other.

[0054] In addition to being misaligned in the width direction of the reflective film according to the above-mentioned offset difference, the local pre-fixed areas at both ends of the unpressed release section are also staggered along the gap extension direction, so that the ends of the two local pre-fixed areas that are adjacent to each other maintain a distance along the gap extension direction. Figure 4 The unpressed release section extends along the gap direction between two local pre-fixed areas. The adjacent ends of these two local pre-fixed areas are not located at the same extension position, thus allowing the lateral constraints on both sides to be established sequentially, rather than being concentrated at the location of the shift in offset direction. After completing the previous local pre-fixed area, the flexible heating belt crosses the area of ​​the shift in offset direction and then forms the next local pre-fixed area at a position offset from the previous one along the gap extension direction. Therefore, the width offset accommodates changes in the direction and degree of gap offset on both sides of the release section, and the offset gap extension direction reduces the concentration of lateral constraints on both sides at the same location. This ensures that the reflective film retains continuous unpressed adjustment space in the area of ​​the shift in offset direction and reduces the possibility of the reflective film's position shifting due to the continuous transmission of lateral traction generated by the local pre-fixed areas on both sides.

[0055] Example 2:

[0056] This embodiment provides a visual alignment-based method for local contact pre-fixation of reflective film in photovoltaic module gaps. After acquiring the image of the cell array, continuous detection positions are set along the extension direction of the gap between adjacent cells. The boundary of the adjacent cells facing the gap at each detection position is identified, and the corresponding gap width is obtained based on the distance between the two boundaries. Before performing visual inspection, image size calibration is performed using a known size reference, so that the pixel positions in the image can be converted into actual positions along the gap extension direction and actual distances along the width direction of the reflective film. Subsequently, the detected gap widths are continuously compared along the gap extension direction, and the width change process of the local gap from a stable state to a minimum value and then gradually recovers is identified by combining the gap offset direction change position.

[0057] When comparing gap widths along the gap extension direction, the position where the gap width begins to decrease from a stable state is determined as the starting position of the gap width reduction region, and the gap width corresponding to this starting position is used as the reference gap width. Continue detection along the gap extension direction, recording the width at each detection position as the gap width continues to decrease, and determine the minimum gap width from this region. After the gap width reaches its minimum value, detection continues. When the gap width at subsequent detection positions changes from decreasing to increasing, it indicates that the gap width recovery process begins at that position. For example... Figure 5 As shown, the continuous detection results along the gap extension direction are divided into a width reduction region and a width recovery interval. The 10 mm position is the starting position of the width reduction, the 30 mm position corresponds to the minimum gap width, and the detection positions after 30 mm reflect the gap width recovery process in sequence, so that the starting position, the narrowest position and the recovery trend of the local narrow gap can be determined in the same detection sequence.

[0058] To characterize the degree of reduction in local gap width relative to the initial state of the gap width reduction region, this embodiment uses the relative reduction in gap width q for quantification, and its calculation formula is as follows:

[0059]

[0060] In the formula, q represents the relative reduction in gap width and is a dimensionless quantity; The reference gap width is the starting position of the gap width reduction area, in mm. The minimum gap width detected within the area where the gap width is reduced is expressed in mm. The results are derived from visual detection at the location where the gap width begins to decrease. It is derived from the minimum width obtained by continuing to detect along the direction of the gap extension from that position. and The difference represents the actual reduction in width of the region relative to its initial state. This reduction in width is then compared with... By comparison, q can reflect the degree of contraction of the local narrow gap relative to its initial width. The larger q is, the more obvious the reduction of the local gap relative to the initial state. During implementation, this can be used to keep the gap width reduction area and its recovery interval in an uncovered state, and to determine the actual coverage range of the uncovered release section in combination with the subsequent width recovery position. However, q is not the only criterion limiting the scope of this method.

[0061] To illustrate the above visual inspection and calculation process, this embodiment uses a set of example inspection data. This set of data is used to illustrate the implementation process of the method and does not represent the actual measurement results on a production line, nor does it constitute a limitation on the parameter range of this method. Seven inspection positions are set along the gap extension direction. The actual positions of each inspection position are 0 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, and 60 mm, respectively, and the corresponding detected gap widths are 1.000 mm, 1.000 mm, 0.910 mm, 0.760 mm, 0.820 mm, 0.930 mm, and 1.000 mm, respectively. Continuous testing results show that the gap width remains constant at 1.000 mm from 0 mm to 10 mm. After 10 mm, the gap width begins to decrease, reaching a minimum of 0.910 mm at 20 mm and a minimum of 0.760 mm at 30 mm. It then increases to 0.820 mm at 40 mm, 0.930 mm at 50 mm, and returns to 1.000 mm at 60 mm. Therefore, the 10 mm position is defined as the starting point of the gap width reduction region, and the corresponding 1.000 mm is defined as... The 0.760 mm obtained from the 30 mm position detection was determined as... . Figure 5 The detection curves and values ​​at each detection position further indicate that the gap width continuously decreases from 10 mm to 30 mm, and then recovers gradually after 30 mm. This avoids ignoring the subsequent recovery process by determining the release area based on a single narrow point.

[0062] Substitute the above data into the formula for calculating the relative reduction in gap width:

[0063]

[0064] Therefore, q is 0.240, which means that the relative reduction in gap width is 24%. The difference between 1.000 mm and 0.760 mm is 0.240 mm, and the ratio of this width reduction to the reference gap width of 1.000 mm is 0.240. Therefore, the above calculation result corresponds to the detection data of the implementation example. Figure 5 Middle reference width Minimum width The correspondence between q and q is used to reflect the degree to which the local gap shrinks from its initial width to its minimum width. After recognizing this width change, the flexible heating strip forms a previous local pre-fixed area near the 10 mm position, and then stops forming local overlay along the gap extension direction, so that the reflective film is constrained by the already formed previous local pre-fixed area on one side across the local narrow gap and its subsequent width recovery range.

[0065] While determining the other end of the unpressurized release section, continue to measure the gap width along the gap extension direction. The actual position in the gap extension direction where the gap width begins to decrease is determined as... The actual position at which the gap width is restored at the other end and reaches the gap width corresponding to the previous local pre-fixed area is determined as follows: . and All are obtained by converting the detection locations in the visual image after size calibration. For example... Figure 6 As shown, the reflective film is laid along the middle of the gap, and the previous local pre-fixed area is set in Nearby, the next partial pre-fixed area is set up Nearby, the reflective film area between the two remains uncovered. Figure 6 It also shows the boundary profile of adjacent cells facing the gap side. The gap reaches its narrowest state near the 30 mm position and then gradually recovers, so that the unpressurized release section not only covers the area where the width continues to decrease, but also continues to extend to the position where the gap width recovers to the width corresponding to the previous local pre-fixed area.

[0066] The coverage length S of the uncovered release section along the gap extension direction is determined by the following formula:

[0067]

[0068] In the formula, S is the coverage length of the uncovered release section along the gap extension direction, in mm; These are the actual position coordinates corresponding to the location where the gap width begins to decrease, in mm; The coordinates, in mm, represent the actual position when the gap width is restored and reaches the gap width corresponding to the previous local pre-fixed area. Since... lie in The positional difference between the two along the direction of the gap extension is the actual length that the unpressed release section needs to cover, and can be used as the control distance that the flexible heating belt crosses along the direction of the gap extension after it stops pressing. Figure 6 middle and The dimensional relationship between them corresponds to the coverage range of the uncovered release section, with the narrowest position located in the middle of this range, so that the local narrow gap and its subsequent recovery section are not constrained by continuous overlay.

[0069] In the detection data of the above implementation example, The gap width at this location is 10 mm, and the corresponding gap width is 1.000 mm. After the flexible heating band forms the previous local pre-fixed area near this location, it stops pressing. The reflective film sequentially crosses the 0.910 mm gap at the 20 mm location, the narrowest gap at the 30 mm location (0.760 mm), the recovery gap at the 40 mm location (0.820 mm), and the recovery gap at the 50 mm location (0.930 mm). When the detection reaches the 60 mm location, the gap width recovers to 1.000 mm, the same as the gap width corresponding to the previous local pre-fixed area, therefore it is determined... The length is 60 mm, forming a subsequent local pre-fixation zone near this location. The corresponding uncompressed release section coverage length is:

[0070]

[0071] This determines that the flexible heating band extends a gap of 50 mm after the 10 mm position, and restores localized pressing at the 60 mm position. Figure 7 As shown, the entire pre-fixing process is implemented sequentially according to the formation of the previous local pre-fixing zone, the crossing of the unpressed release section, and the formation of the next local pre-fixing zone. In the first stage, the flexible heating belt... In the first stage, a pre-fixed area is formed nearby, keeping the subsequent release section uncompacted; in the second stage, the pre-fixed area continues to provide unilateral positional constraint, and the flexible heating band crosses the release section along the gap extension direction without compressing it; in the third stage, when the gap width is within... After the position is restored to 1.000 mm, the flexible heating band forms a local pre-fixed zone at that position, and to The release section between them remains uncompressed.

[0072] As the flexible heating strip crosses the unpressurized release section, the reflective membrane is primarily constrained on one side by the pre-fixed local area. Since the other end has not yet formed a pre-fixed local area, the reflective membrane can make local lateral adjustments in the local narrow gap and its recovery range according to the actual gap boundary and gap width changes. Figure 7 The unilateral constraint state shown demonstrates that the reflective film still possesses positional adaptability before the formation of the subsequent local pre-fixed area. The crossing path of the flexible heating band corresponds to S, allowing the movement distance of the flexible heating band to be directly obtained through visual detection. and Confirmed. The flexible heating band does not form continuous thermo-pressure contact with the release section when crossing this section, thus avoiding premature establishment of bilateral constraints near the narrowest point.

[0073] Once visual inspection confirms that the gap width at the 60 mm position has recovered and reached the 1.000 mm gap width corresponding to the previous local pre-fixed area, the flexible heating band forms a subsequent local pre-fixed area at that position, thus completing the positional constraint on the other end of the unpressed release section. The previous and subsequent local pre-fixed areas are formed sequentially, rather than simultaneously pressing at both ends of the narrow local gap. If both ends of the narrow local gap are pressed simultaneously, the lateral positional constraint formed at both ends may exert opposing traction on the reflective film, and... Figure 7 The sequential pre-fixing process shown allows the reflective film to first cross the narrow gap and complete the corresponding position adjustment under the constraint of the previous local pre-fixing area, and then establish the next local pre-fixing area after the gap width is restored, thereby avoiding the intermediate release area being closed and constrained before the adjustment is completed.

[0074] By means of the above method, the process of changing the gap width obtained by visual inspection is correlated with the local pressing action of the flexible heating belt, according to and Determine the relative reduction in local gaps, and based on... and The actual coverage length of the unpressed release section is determined so that the flexible heating belt crosses the area where the gap width decreases and its recovery range. A unilateral position constraint is first formed at one end, and the gap width at the other end is restored to the width corresponding to the previous local pre-fixed area before the next local pre-fixed area is formed. This reduces the possibility of the reflective film being pulled in opposite directions due to pressure at both ends of the local narrow gap, and preserves the reflective film's lateral adjustment capability in the gap width variation area.

[0075] The reflective film used in this application does not constitute a limitation on the type or function of the film material. In practical applications, the film material can also be selected based on the performance, appearance, or process requirements of the photovoltaic module, and can have functions such as reflection, anti-reflection, shading, decoration, protection, flexible support, or other functions. These include, but are not limited to, reflective film, EV film, appearance film, black film, flexible film, and other film materials that can achieve the same or similar technical effects. Any application of the above-mentioned film materials and implementation of the visual alignment, position adjustment, and partial contact pre-fixing methods described in this invention falls within the protection scope of this invention.

Claims

1. A method for localized contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment, characterized in that: Acquire an image of the battery cell array, identify the gap boundary and gap width of adjacent battery cells at each detection position along the gap extension direction, and determine the offset direction and offset amount of the gap relative to the predetermined laying position; The reflective film laying position is determined according to the gap boundary and gap width. The reflective film is laid in the corresponding gap area, and the local pressing position of the flexible heating belt in the width direction of the reflective film is determined according to the offset direction, so that the flexible heating belt forms a locally pre-fixed area arranged at intervals along the gap extension direction. When the offset directions of adjacent detection positions are consistent, a local pre-fixed area is formed along the gap extension direction. When the offset direction changes from toward one side of the battery cell boundary to toward the other side of the battery cell boundary, the local pressing is interrupted. After crossing the offset direction and changing position, the local pre-fixed area is re-formed, so that an unpressed release section is formed between the two local pre-fixed areas to isolate the lateral traction transmission of the local pre-fixed area to the reflective film.

2. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 1, characterized in that: The local pre-fixed area is formed by multiple pressing. The flexible heating strip first forms an initial pressing area on the side of the reflective film away from the cell boundary pointed to by the offset direction in the width direction. After the adjacent local pre-fixed area is formed, the flexible heating strip presses again in the initial pressing area, so that the side of the reflective film close to the cell boundary remains unpressed.

3. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 1, characterized in that: The local pre-fixed areas at both ends of the unpressed release section are located on different sides of the reflective film width direction, and are located on the side away from the cell boundary pointed to by the corresponding offset direction, so that the local pre-fixed areas at both ends of the unpressed release section are misaligned in the reflective film width direction.

4. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 1, characterized in that: When the gap width at the offset direction change position is less than the gap width of the adjacent areas on both sides of the change position, the flexible heating band crosses the offset direction change position and forms local pre-fixed areas at the starting positions where the gap width on both sides of the change position changes from decreasing to increasing, so that the unpressed release section covers the area where the gap width decreases.

5. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 3, characterized in that: The gap offset on both sides of the unpressed release section is determined as the first offset and the second offset. The misalignment distance of the two local pre-fixed areas in the width direction of the reflective film is determined based on the difference between the first offset and the second offset. The local pre-fixed area corresponding to the higher offset is offset to the side away from the battery cell boundary pointed to by the corresponding offset direction, so as to reduce the lateral traction difference at both ends of the unpressed release section.

6. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 3, characterized in that: The local pre-fixed areas at both ends of the unpressed release section are formed sequentially in ascending order of the corresponding gap offset values. Before forming the next local pre-fixed area, the end of the reflective film close to the next local pre-fixed area is kept unpressed in the width direction, and the position constraint of the reflective film is completed after the next local pre-fixed area is formed.

7. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 3, characterized in that: The local pre-fixed areas at both ends of the unpressed release section are staggered along the gap extension direction, so that the adjacent ends of the two local pre-fixed areas are spaced apart along the gap extension direction, and the local pre-fixed areas at both ends of the unpressed release section are misaligned in the width direction of the reflective film, so that the reflective film forms a lateral constraint that is staggered along the gap extension direction at the position where the offset direction changes.

8. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 4, characterized in that: The unpressed release section covers the area where the gap width decreases along the gap extension direction and extends to the position where the gap width is restored to the width corresponding to the starting position of the area where the gap width decreases. This allows the local pre-fixed areas at both ends of the unpressed release section to be located at both ends of the area where the gap width decreases, so that the lateral constraint generated by the local narrow gap is released within the unpressed release section.

9. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 4, characterized in that: The local pre-fixed areas at both ends of the unpressed release section are formed sequentially. First, a previous local pre-fixed area is formed at one end of the gap width reduction area. Then, the reflective film is made to cross the gap width reduction area along the gap extension direction and a subsequent local pre-fixed area is formed at the other end to avoid the reflective film being pulled in opposite directions by pressure at both ends of the local narrow gap.

10. The method for local contact pre-fixation of reflective film in photovoltaic module gaps based on visual alignment according to claim 9, characterized in that: The subsequent local pre-fixed area is formed after the gap width is restored and reaches the gap width corresponding to the previous local pre-fixed area, so that the unpressed release section crosses the area where the gap width is reduced, and the previous local pre-fixed area forms a unilateral constraint on the reflective film until the gap width reaches the gap width corresponding to the previous local pre-fixed area.

Images