Photovoltaic module
By setting an offset reflective structure in the photovoltaic module, the problem of light leakage caused by cell slippage is solved, thereby improving the light energy utilization rate and photoelectric conversion efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG JINKO SOLAR CO LTD
- Filing Date
- 2022-11-03
- Publication Date
- 2026-07-31
AI Technical Summary
During the lamination process of photovoltaic modules, the slippage of the cells can cause a misalignment between the gaps between the cells or between the strings and the position of the reflective film, resulting in light leakage.
A reflective structure is incorporated into the photovoltaic module, offset relative to the gaps, to compensate for the slippage of the solar cells and ensure that no light leaks from the area covered by the reflective structure.
By offsetting the reflective structure, the light energy utilization rate and photoelectric conversion rate are improved, and light leakage is prevented.
Smart Images
Figure CN115692531B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic technology, and more particularly to a photovoltaic module. Background Technology
[0002] To improve light utilization, traditional photovoltaic (PV) modules typically incorporate reflective films evenly distributed between strings or cells. However, during the lamination process, cell slippage can occur, causing positional misalignment between the reflective films and the cell or string gaps, resulting in light leakage. Summary of the Invention
[0003] The purpose of this application is to provide a photovoltaic module to solve the problem of light leakage caused by the positional deviation between the solar cells and the reflective film during the lamination process of existing photovoltaic modules.
[0004] This application provides a photovoltaic module, comprising:
[0005] Multiple battery strings are arranged in parallel along the width direction of the photovoltaic module, and a first gap is provided between two adjacent battery strings; each battery string includes multiple battery cells, and a second gap is provided between two adjacent battery cells along the length direction of the photovoltaic module.
[0006] A back panel, wherein a third gap is provided between the edge of the back panel and the battery string near the edge of the back panel, and a reflective structure is provided on the back panel at a position corresponding to the third gap; and / or the reflective structure is provided on the back panel at a position corresponding to the first gap and / or the second gap;
[0007] Wherein, along the sliding direction of the battery cell in the lamination process, the reflective structure has an offset relative to at least one of the third gap, the first gap and the second gap.
[0008] In one possible design, the reflective structure includes a plurality of first reflective films disposed in corresponding first gaps, and at least a portion of the first reflective films along a first direction having a first offset relative to the corresponding first gap, the first direction being the sliding direction of the battery string in the lamination process.
[0009] In one possible design, the reflective structure includes a plurality of second reflective films disposed in corresponding second gaps, wherein at least a portion of the second reflective films have a second offset relative to the corresponding second gap along a second direction, the second direction being the sliding direction of the battery cells in the lamination process in a direction perpendicular to the length of the battery string.
[0010] In one possible design, along the length direction, the first reflective film has a first center line, the first gap has a second center line, and the photovoltaic module has a third center line;
[0011] The first center line of the first reflective film is offset away from the third center line of the photovoltaic module relative to the second center line of the corresponding first gap, and at least a portion of the first offset of the first center line of the first reflective film relative to the second center line of the corresponding first gap gradually increases from the third center line of the photovoltaic module towards both sides in the width direction.
[0012] In one possible design, the number of the first reflective film and the first gap is N, where N is an odd number greater than or equal to 3, and the center line of the first reflective film located in the middle of the photovoltaic module coincides with the center line of the corresponding first gap.
[0013] The first reflective film, excluding the first reflective film located at the center of the photovoltaic module, has the first offset relative to the corresponding first gap along the first direction.
[0014] In one possible design, the first offset is determined by the following formula:
[0015] u(n)=(0.2~0.4)mm+(n-1)*0.2mm;
[0016] Where u is the first offset; n is the nth first reflective film arranged from the center of the photovoltaic module to any side of the width direction, excluding the first reflective film located at the center of the photovoltaic module, n = 1, 2, 3...
[0017] In one possible design, the first offset ranges from 0.2 to 1 mm.
[0018] In one possible design, along the width direction, the second reflective film has a fourth center line, the second gap has a fifth center line, and the photovoltaic module has a sixth center line;
[0019] The fourth center line of the second reflective film is offset relative to the fifth center line of the corresponding second gap towards the sixth center line of the photovoltaic module, and at least a portion of the second offset of the fourth center line of the second reflective film relative to the fifth center line of the corresponding second gap gradually increases from the sixth center line of the photovoltaic module towards both sides of the length direction.
[0020] In one possible design, the second offset is determined by the following formula:
[0021] w1(m)=(m-1)*(0.02~0.05);
[0022] Where w1 is the second offset; m is the m-th second reflective film arranged from the center of the photovoltaic module to any side of the length direction, m = 1, 2, 3...
[0023] In one possible design, the second offset is determined by the following formula:
[0024]
[0025] Where w2 is the second offset; k is the kth second reflective film arranged from the center of the photovoltaic module to any side of the length direction, k = 1, 2, 3...; q is the total number of second reflective films with a fixed second offset arranged continuously from the center of the photovoltaic module to any side of the length direction.
[0026] In one possible design, the second offset ranges from 0.04 to 0.44 mm.
[0027] In one possible design, the reflective structure includes a third reflective film disposed on the back panel at a position corresponding to the third gap, the offset of the third reflective film relative to the third gap being 0.5 to 2 mm.
[0028] The technical solution provided in this application can achieve the following beneficial effects:
[0029] The photovoltaic module provided in this application compensates for the slippage of the solar cells by offsetting the reflective structure in the length or width direction of the photovoltaic module. This prevents light leakage in the area covered by the reflective structure, thereby improving the utilization rate of light energy and the photoelectric conversion efficiency.
[0030] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description
[0031] Figure 1 A schematic diagram of the photovoltaic module provided in the embodiments of this application;
[0032] Figure 2 This is a schematic diagram of the back panel (showing the positions of the first and second gaps).
[0033] Figure label:
[0034] 1-Back panel;
[0035] 2-First gap;
[0036] 3-Second gap;
[0037] 4-First reflective film;
[0038] 5-Second reflective film;
[0039] a-First centerline;
[0040] b - Second centerline;
[0041] c - Third center line;
[0042] d - Fourth centerline;
[0043] e-Fifth Center Line;
[0044] f-Sixth center line;
[0045] X - Length direction;
[0046] Y - Width direction.
[0047] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation
[0048] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0049] In the description of this application, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0050] In the description of this specification, it should be understood that the directional terms such as "upper" and "lower" used in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should also be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.
[0051] To improve light utilization, traditional photovoltaic modules typically incorporate reflective films evenly distributed between strings or between cells. Specifically, the centerline of the reflective film located between strings is aligned with the centerline of the string gap, while the centerline of the reflective film located between cells is aligned with the centerline of the cell gap.
[0052] However, since photovoltaic modules have a multi-layer structure, such as adhesive layer, cell layer, and back panel layer, a stable structure needs to be formed through lamination process. During the lamination process, the adhesive layer will stretch and deform, causing the cells to slip. This leads to a positional deviation between the center line of the cell gap or string gap and the center line of the reflective film. Some light will penetrate the back panel and cannot be reflected by the reflective film, causing light leakage problem.
[0053] This application provides a photovoltaic module, which, from top to bottom, may include a cover plate, an upper encapsulating film, multiple cell strings, a lower encapsulating film, and a back panel 1. The multiple cell strings are arranged parallel to each other along the width direction Y of the photovoltaic module, and a first gap 2 is provided between adjacent cell strings; each cell string includes multiple solar cells, and a second gap 3 is provided between adjacent solar cells along the length direction X of the photovoltaic module.
[0054] The back panel 1 is provided with a reflective structure that can reflect light onto the solar cells to increase the utilization rate of light energy.
[0055] In one embodiment, a third gap is provided between the edge of the back panel 1 and the cell string near the edge of the back panel 1, and a reflective structure is disposed on the back panel 1 at a position corresponding to the third gap. The third gap can surround the edge of the back panel 1, and the reflective structure located at the third gap can reflect light onto adjacent cells to improve the utilization rate of light illuminating the edge of the photovoltaic module.
[0056] In another embodiment, the reflective structure can be disposed on the back panel 1 at a position corresponding to the first gap 2, or at a position corresponding to the second gap 3, or both at a position corresponding to the first gap 2 and a position corresponding to the second gap 3, so as to reflect the light that shines on the back panel 1 from between the battery cells or between the battery strings back to the battery cells, thereby improving the light utilization rate.
[0057] In another embodiment, the reflective structure can be set at the position corresponding to the third gap on the back panel 1, or at the position corresponding to the first gap 2 or the second gap 3 on the back panel 1. The reflective structure can also be set at the position corresponding to the third gap on the back panel 1, and at the position corresponding to the first gap 2 and the second gap 3 on the back panel 1, so that the light at the edge of the photovoltaic module, as well as the light between the cells and between the cells and the strings, can be fully utilized at the same time, thereby improving the photoelectric conversion efficiency.
[0058] Along the sliding direction of the solar cell in the lamination process, the reflective structure has an offset relative to at least one of the third gap, the first gap 2, and the second gap 3.
[0059] It is understandable that the sliding direction of the solar cells is not regular during the lamination process, but the sliding direction of the solar cells can be equivalent to the offset in the length direction X or width direction Y of the photovoltaic module. The reflective structure has a certain width, and the offset of the reflective structure in the length direction X or width direction Y of the photovoltaic module can compensate for the sliding amount of the solar cells. Therefore, in the laminated photovoltaic module, the reflective structure can be aligned with at least one of the third gap, the first gap 2, or the second gap 3. That is, the reflective structure can completely cover the third gap, the first gap 2, or the second gap 3. There will be no light leakage problem in the area covered by the reflective structure, thereby improving the utilization rate of light energy and the photoelectric conversion efficiency.
[0060] In a specific implementation, such as Figure 1 and Figure 2 As shown, the reflective structure includes multiple first reflective films 4, which are disposed in corresponding first gaps 2. At least a portion of the first reflective films 4 have a first offset relative to the corresponding first gap 2 along a first direction, where the first direction is the sliding direction of the battery string during the lamination process. Figure 1 The widths of the first reflective film 4 and the first gap 2 are only schematic widths for the purpose of illustrating the scheme and do not represent the actual widths and proportions.
[0061] In this embodiment, when considering the slippage of the solar cells in the width direction Y of the photovoltaic module, the entire solar cell string can be considered as the object of study. The length direction X of the solar cell string is consistent with the length direction X of the photovoltaic module, and the slippage direction of the solar cell string can be regarded as a slippage along the width direction Y of the photovoltaic module. That is, the first direction mentioned above can be equivalent to the width direction Y of the photovoltaic module. It is understood that when the solar cell string does not slip, the position of the first reflective film 4 on the back panel 1 can be aligned with the first gap 2. However, after the solar cell string undergoes the lamination process, the slippage of the solar cell string will cause the first gap 2 between the solar cell strings to shift, which in turn causes the first gap 2 after the lamination process to not be aligned with the first reflective film 4 in its original position.
[0062] In order to align the first reflective film 4 with the first gap 2 after lamination, the first reflective film 4 can be pre-offset on the back panel 1 along the sliding direction of the battery string by a first offset amount relative to its original position, based on the theoretical or empirical sliding amount of the battery string. This first offset amount can be the same as the sliding amount of the battery string, so that after the battery string is laminated and slid, the first gap 2 between the battery strings can be aligned with the first reflective film 4, preventing light leakage.
[0063] In a specific implementation, such as Figure 1 and Figure 2 As shown, the reflective structure includes multiple second reflective films 5, which are disposed in corresponding second gaps 3. Along a second direction, at least a portion of the second reflective films 5 have a second offset relative to the corresponding second gap 3. The second direction is the sliding direction of the battery cells during the lamination process, perpendicular to the length direction X of the battery string. Figure 1 The widths of the second reflective film 5 and the second gap 3 are only schematic widths for illustrative purposes and do not represent the actual widths and proportions.
[0064] Since the slippage of the solar cells in the width direction Y of the photovoltaic module was studied primarily with regard to the cell string, in this embodiment, when considering the slippage of the solar cells in the length direction X of the photovoltaic module, the study can focus solely on the solar cells within the cell string. That is, the slippage of the solar cells in the second direction can be equivalent to the slippage of the solar cells in the width direction Y of the photovoltaic module.
[0065] Understandably, if the solar cells do not slip, the second reflective film 5 on the back panel 1 can be aligned with the second gap 3. However, after the solar cells undergo the lamination process, slippage of the solar cells will cause the second gap 3 between the solar cells to shift, which in turn will cause the second gap 3 after the lamination process to not be aligned with the second reflective film 5 in its original position.
[0066] In order to align the second reflective film 5 with the second gap 3 after lamination, the second reflective film 5 can be pre-offset on the back panel 1 along the sliding direction of the battery cell by a second offset amount relative to its original position, based on the theoretical or empirical sliding amount of the battery cell. This second offset amount can be the same as the sliding amount of the battery cell, so that after the battery cell is laminated and slid, the second gap 3 between the battery cells can be aligned with the second reflective film 5, preventing light leakage.
[0067] In one specific implementation, along the length direction X of the photovoltaic module, the first reflective film 4 has a first center line a, the first gap 2 has a second center line b, and the photovoltaic module has a third center line c. The first center line a of the first reflective film 4 is offset relative to the second center line b of the corresponding first gap 2 in a direction away from the third center line c of the photovoltaic module, and at least part of the first offset of the first center line a of the first reflective film 4 relative to the second center line b of the corresponding first gap 2 (which is the first gap 2 formed when the battery string has not undergone a lamination process) gradually increases from the third center line c of the photovoltaic module towards both sides in the width direction Y.
[0068] When laminating photovoltaic modules, the adhesive layer stretches and deforms under pressure, causing the amount of slippage accumulated near the edge of the photovoltaic module to be greater. Therefore, by gradually increasing the first offset from the third center line c of the photovoltaic module to both sides of the width direction Y, each first reflective film 4 can be aligned with the corresponding first gap 2, effectively preventing light leakage.
[0069] In one specific implementation, the number of first reflective film 4 and first gap 2 is N, where N is an odd number greater than or equal to 3. The center line of the first reflective film 4 located in the middle of the photovoltaic module coincides with the center line of the corresponding first gap 2. During the lamination process, the two battery strings adjacent to the first reflective film 4 located in the middle of the photovoltaic module hardly slip or the slippage is negligible. Before and after lamination, the first reflective film 4 located in the middle of the photovoltaic module can be aligned with the first gap 2 located in the middle of the photovoltaic module. Therefore, the offset of the first reflective film 4 located in the middle of the photovoltaic module can be ignored.
[0070] Except for the first reflective film 4 located at the center of the photovoltaic module, the first reflective film 4 has a first offset relative to the corresponding first gap 2 along the first direction.
[0071] Specifically, in one embodiment, such as Figure 1 and Figure 2 As shown, the battery string has six cells, forming five first gaps 2. The center line of the middle first gap 2 coincides with the center line of the photovoltaic module. Of course, in other embodiments, there may be seven, nine, or other first gaps 2.
[0072] In one specific implementation, the number of first reflective films 4 and first gaps 2 can both be even, for example, 2, 4, 6, 8, or 10 first reflective films 4 and first gaps 2, respectively. The first gaps 2 can be symmetrically distributed on both sides of the third center line c of the photovoltaic module, and each first reflective film 4 corresponding to each first gap 2 can have a first offset. In some other embodiments, since the slippage of the cell string near the third center line c of the photovoltaic module is small and can be ignored, the portion of the first reflective film 4 near the third center line c of the photovoltaic module may not have a first offset.
[0073] In one specific implementation, the first offset is determined by the following formula:
[0074] u(n)=(0.2~0.4)mm+(n-1)*0.2mm;
[0075] Where u is the first offset; n is the nth first reflective film 4 arranged from the center of the photovoltaic module to any side of the width direction Y, except for the first reflective film 4 located at the center of the photovoltaic module, n=1,2,3….
[0076] For example, such as Figure 1 As shown, when there are 5 first reflective films 4, there are 2 on each side of the first reflective film 4 located in the middle. When n=1, according to the above formula, u(1)=0.2mm~0.4mm, that is, the first offset of the first first reflective film 4 arranged from the center of the photovoltaic module to any side of the width direction Y is 0.2mm~0.4mm. Specifically, u(1)=0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, etc.
[0077] For example, such as Figure 1 As shown, when there are 5 first reflective films 4, there are 2 on each side of the first reflective film 4 located in the middle. When n=2, according to the above formula, u(2)=0.4mm~0.6mm, that is, the first offset of the second first reflective film 4 arranged from the center of the photovoltaic module to any side of the width direction Y is 0.4mm~0.6mm. Specifically, u(2)=0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, etc.
[0078] Therefore, when the value of n is larger, that is, when the position of the first reflective film 4 is further away from the center of the photovoltaic module along the width direction Y, the first offset of the first reflective film 4 is larger, so that the offset state of the first reflective film 4 at different positions can match the sliding state of the battery string after lamination, effectively avoiding light leakage.
[0079] Specifically, the first offset of the first reflective film 4 is in the range of 0.2 to 1 mm, which can be used to solve the light leakage problem of photovoltaic modules of different types.
[0080] In one specific implementation, along the width direction Y, the second reflective film 5 has a fourth center line d, the second gap 3 has a fifth center line e, and the photovoltaic module has a sixth center line f. The fourth center line d of the second reflective film 5 is offset relative to the fifth center line e of the corresponding second gap 3 towards the sixth center line f of the photovoltaic module, and at least a portion of the second offset of the fourth center line d of the second reflective film 5 relative to the fifth center line e of the corresponding second gap 3 (which is a second gap 3 formed when the solar cells have not undergone a lamination process) gradually increases from the sixth center line f of the photovoltaic module towards both sides in the length direction X.
[0081] When laminating photovoltaic modules, the adhesive layer is stretched and deformed under pressure, resulting in a greater amount of slippage accumulated near the edge of the photovoltaic module. Therefore, by gradually increasing the second offset from the sixth center line f of the photovoltaic module to both sides of the length direction X, each second reflective film 5 can be aligned with the corresponding second gap 3, effectively preventing light leakage.
[0082] Specifically, the second offset is determined by the following formula:
[0083] w1(m)=(m-1)*(0.02~0.05);
[0084] Where w1 is the second offset; m is the m-th second reflective film 5 arranged from the center of the photovoltaic module to any side of the length direction X, m=1,2,3….
[0085] For example, such as Figure 1 As shown, when there are 22 second reflective films 5, 11 of them are located on one side of the sixth center line f of the photovoltaic module, and the remaining 11 are located on the other side of the sixth center line f of the photovoltaic module. When m = 1, according to the above formula, w(1) = 0, that is, the second reflective film 5 adjacent to the sixth center line f of the photovoltaic module has no offset, that is, the solar cells adjacent to the sixth center line f of the photovoltaic module hardly slip.
[0086] For example, when m=3, according to the above formula, w(3)=0.04mm~0.1mm, that is, the second offset of the third second reflective film 5 arranged from the center of the photovoltaic module to any side of the length direction X is 0.04mm~0.1mm. Specifically, w(3)=0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, etc.
[0087] For example, when m = 5, according to the above formula, w(5) = 0.1mm ~ 0.25mm, that is, the second offset of the fifth second reflective film 5 arranged from the center of the photovoltaic module to any side of the length direction X is 0.08mm ~ 0.2mm. Specifically, w(3) = 0.08mm, 0.12mm, 0.15mm, 0.16mm, 0.18mm, 0.2mm, etc.
[0088] Therefore, the larger the value of m, that is, the further away the position of the second reflective film 5 is from the center of the photovoltaic module along the length direction X, the larger the second offset of the second reflective film 5 is. This allows the offset state of the second reflective film 5 at different positions to match the sliding state of the battery string after lamination, effectively avoiding light leakage.
[0089] Specifically, in one embodiment, when m is 1-11, the corresponding second offset is 0, 0.04mm, 0.08mm, 0.12mm, 0.16mm, 0.20mm, 0.24mm, 0.28mm, 0.32mm, 0.36mm, or 0.40mm. Alternatively, in another embodiment, when m is 1-11, the corresponding second offset is 0, 0.03mm, 0.06mm, 0.09mm, 0.12mm, 0.15mm, 0.18mm, 0.21mm, 0.24mm, 0.27mm, or 0.30mm.
[0090] In one specific implementation, the second offset can be determined by the following formula:
[0091]
[0092] Where w2 is the second offset; k is the kth second reflective film 5 arranged from the center of the photovoltaic module to any side of the length direction X, k = 1, 2, 3...; q is the total number of second reflective films 5 arranged continuously from the center of the photovoltaic module to any side of the length direction X with a fixed second offset.
[0093] In this embodiment, the cells near the center of the photovoltaic module hardly slip along the length direction X, or the slip is so small as to be negligible. Therefore, the corresponding second reflective film 5 may not have an offset. In this embodiment, q can be used to represent the number of consecutive second reflective amounts with a fixed second offset near the center of the photovoltaic module.
[0094] For example, when q = 7, if the value of k is less than or equal to 7, then w2(k≤7) = 0.1~0.25mm, that is, the second offset of the seven consecutive second reflective films 5 on either side of the photovoltaic module center along the length direction X is the same constant value, specifically 0.1mm, 0.15mm, 0.2mm or 0.25mm, etc. When k > 7, for example, k = 8, according to the above formula, w2(8) = (0.02~0.05)mm + (0.1~0.25)mm = (0.12~0.30)mm, specifically 0.12mm, 0.15mm, 0.20mm, 0.22mm, 0.25mm, 0.26mm, 0.30mm.
[0095] Specifically, in one embodiment, q = 7, and when k is 1-11, the corresponding second offsets are 0.02mm, 0.02mm, 0.02mm, 0.02mm, 0.02mm, 0.02mm, 0.02mm, 0.22mm, 0.26mm, 0.30mm, and 0.35mm respectively.
[0096] Of course, in some other embodiments, at least one second reflective film 5 adjacent to the center of the photovoltaic module along the length direction X has no offset, while some of the other second reflective films 5 arranged continuously may have the same second offset. For example, when 11 second reflective films 5 are arranged from the center of the photovoltaic module to any side of the length direction X, starting from the center of the photovoltaic module, the second offset of the second reflective film 5 can be 0, 0.10mm, 0.15mm, 0.15mm, 0.15mm, 0.20mm, 0.25mm, 0.25mm, 0.25mm, 0.30mm, and 0.30mm respectively.
[0097] Specifically, the second offset of the second reflective film 5 is in the range of 0.04 to 0.44 mm, which can be used to solve the light leakage problem of photovoltaic modules of different types.
[0098] In one specific implementation, the reflective structure may further include a third reflective film, which is disposed on the back panel 1 at a position corresponding to the third gap, and the offset of the third reflective film relative to the third gap is 0.5 to 2 mm.
[0099] It is understandable that the cell string lamination slippage at the edge of the photovoltaic module is relatively large. Therefore, the third reflective film also needs to have a relatively large offset to prevent light leakage. In this embodiment, by setting the second offset of the third reflective film to a range of 0.5–2 mm, the problem of light leakage at the edge of photovoltaic modules of different types can be solved.
[0100] In one specific implementation, the width of the first reflective film 4 can be 4.5–5.5 mm. This first reflective film 4 is positioned between adjacent battery strings. Currently, if a reflective film is placed between strings, it is generally considered to align the reflective film with the gap, i.e., the centerline of the reflective film coincides with the centerline of the gap. To allow the reflective film to absorb the slippage of the battery strings, its width is often designed to be wider, typically exceeding 6 mm, which increases the material cost. In this embodiment, by having the first reflective film 4 have a first offset relative to the first gap 2 before lamination when it is placed on the back panel 1, the first reflective film 4 can be aligned with the first gap 2 after lamination of the battery strings. Therefore, it is not necessary to design a large width for the reflective film. In this embodiment, the width of the first reflective film 4 can be 4.5–5.5 mm, thereby saving material and cost. Here, the first gap 2 before lamination is a theoretical gap, and the first gap 2 after lamination is the actual gap.
[0101] In one specific implementation, the width of the second reflective film 5 can be 3.5–4.5 mm. This second reflective film 5 is disposed between adjacent solar cells along the X-direction of the photovoltaic module. Currently, if a reflective film is placed between cells, it is generally considered to align the reflective film with the gap, i.e., the centerline of the reflective film coincides with the centerline of the gap. To allow the reflective film to absorb the slippage of the solar cells, its width is often designed to be wider, typically exceeding 5 mm, which increases the material cost. In this embodiment, by having a second offset relative to the second gap 3 before lamination when the second reflective film 5 is placed on the back panel 1, the second reflective film 5 can be aligned with the second gap 3 after lamination of the solar cell string. Therefore, it is not necessary to design a large width for the reflective film. In this embodiment, the width of the second reflective film 5 can be 4.5–5.5 mm, thereby saving material and reducing costs. Here, the second gap 3 before lamination is a theoretical gap, and the second gap 3 after lamination is the actual gap.
[0102] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A photovoltaic module, characterized in that, include: Multiple battery strings are arranged in parallel along the width direction (Y) of the photovoltaic module, and a first gap (2) is provided between two adjacent battery strings; each battery string includes multiple battery cells, and a second gap (3) is provided between two adjacent battery cells along the length direction (X) of the photovoltaic module. A back panel (1) is provided with a third gap between the edge of the back panel (1) and the battery string near the edge of the back panel (1). A reflective structure is provided on the back panel (1) and the reflective structure is provided at a position on the back panel (1) corresponding to the first gap (2). The reflective structure includes a plurality of first reflective films (4). The plurality of first reflective films (4) are provided in the corresponding first gap (2). At least a portion of the first reflective films (4) along a first direction has a first offset relative to the corresponding first gap (2) to compensate for the slippage of the battery cell in the width direction (Y). The first direction is the slippage direction of the battery string in the lamination process. Along the length direction (X), the first reflective film (4) has a first center line (a), the first gap (2) has a second center line (b), and the photovoltaic module has a third center line (c). The first center line (a) of the first reflective film (4) is offset away from the third center line (c) of the photovoltaic module relative to the second center line (b) of the corresponding first gap (2), and the first offset of at least part of the first center line (a) of the first reflective film (4) relative to the second center line (b) of the corresponding first gap (2) gradually increases from the third center line (c) of the photovoltaic module toward both sides of the width direction (Y).
2. The photovoltaic module of claim 1, wherein, The reflective structure includes a plurality of second reflective films (5), which are disposed in corresponding second gaps (3). Along a second direction, at least a portion of the second reflective films (5) have a second offset relative to the corresponding second gaps (3) to compensate for the slippage of the battery cell in the length direction (X). The second direction is the slippage direction of the battery cell in the lamination process in the length direction (X) perpendicular to the length direction (X) of the battery string.
3. The photovoltaic module of claim 1, wherein, The number of the first reflective film (4) and the first gap (2) is N, where N is an odd number greater than or equal to 3. The center line of the first reflective film (4) located at the center of the photovoltaic module coincides with the center line of the corresponding first gap (2). The first reflective film (4), except for the first reflective film (4) located at the center of the photovoltaic module, has the first offset relative to the corresponding first gap (2) along the first direction.
4. The photovoltaic module of claim 3, wherein, The first offset is determined by the following formula: u(n) = (0.2~0.4) mm + (n-1) 0.2 mm; Where u is the first offset; n is the nth first reflective film (4) arranged from the center of the photovoltaic module to any side of the width direction (Y), except for the first reflective film (4) located at the center of the photovoltaic module, u(n) is the first offset of the nth first reflective film, n=1,2,3….
5. The photovoltaic module of claim 1, wherein, The first offset ranges from 0.2 to 1 mm.
6. The photovoltaic module of claim 2, wherein, Along the width direction (Y), the second reflective film (5) has a fourth center line (d), the second gap (3) has a fifth center line (e), and the photovoltaic module has a sixth center line (f); The fourth center line (d) of the second reflective film (5) is offset relative to the fifth center line (e) of the corresponding second gap (3) towards the sixth center line (f) of the photovoltaic module, and the second offset of at least part of the fourth center line (d) of the second reflective film (5) relative to the fifth center line (e) of the corresponding second gap (3) gradually increases from the sixth center line (f) of the photovoltaic module towards both sides of the length direction (X).
7. The photovoltaic module of claim 6, wherein, The second offset is determined by the following formula: w1(m) = (m-1) (0.02~0.05) mm; Where w1 is the second offset; m is the mth second reflective film (5) arranged from the center of the photovoltaic module to any side of the length direction (X), w1(m) is the second offset of the mth second reflective film, m=1,2,3….
8. The photovoltaic module according to claim 6, characterized in that, The second offset is determined by the following formula: ； Where w2 is the second offset; k is the kth second reflective film (5) arranged from the center of the photovoltaic module to any side of the length direction (X), w2(k) is the second offset of the kth second reflective film, k=1,2,3…; q is the total number of second reflective films (5) with a fixed second offset arranged continuously from the center of the photovoltaic module to any side of the length direction (X).
9. The photovoltaic module according to claim 2, characterized in that, The second offset ranges from 0.04 to 0.44 mm.
10. The photovoltaic module of claim 1, wherein, The reflective structure includes a third reflective film, which is disposed on the back panel (1) at a position corresponding to the third gap, and the offset of the third reflective film relative to the third gap is 0.5~2mm.