CN209822658U

CN209822658U - Photovoltaic module

Info

Publication number: CN209822658U
Application number: CN201920287980.6U
Authority: CN
Inventors: 潘秀娟; 黄甫阳; 董经兵; 刘亚锋; 邢国强
Original assignee: Canadian Solar Manufacturing Changshu Inc; CSI Solar Technologies Inc; Atlas Sunshine Power Group Co Ltd
Current assignee: Canadian Solar Inc; CSI Cells Co Ltd; Canadian Solar Manufacturing Changshu Inc
Priority date: 2019-03-07
Filing date: 2019-03-07
Publication date: 2019-12-20
Anticipated expiration: 2029-03-07

Abstract

The embodiment of the utility model provides a photovoltaic module. The photovoltaic module comprises a plurality of battery strings, and each battery string comprises a plurality of solar cells, a solder strip and a buffer layer. The solder strip is used for connecting two adjacent solar cells to connect the solar cells into a string, and the buffer layer can be arranged on the edge of the solar cell, which is crossed with the solder strip, and is positioned between the surface of the solar cell, which is provided with the electrode, and the solder strip.

Description

Photovoltaic module

Technical Field

The utility model relates to a solar energy field especially relates to a photovoltaic module.

Background

In a conventional photovoltaic module, solar cells are connected with each other through solder strips, so that one end of each solder strip is connected to one surface electrode of each solar cell, and the other end of each solder strip is connected to the other surface electrode of the adjacent solar cell, thereby forming a series connection of cells. In the above-mentioned conventional photovoltaic module, since the solder strip needs to be pressed on the edge of the cell, and the contact between the solder strip and the edge of the cell is hard contact, there is a certain possibility that the cell is damaged.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a photovoltaic module.

In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions:

a photovoltaic module comprising a plurality of cell strings, the cell strings comprising:

the solar cells comprise electrodes arranged on the surfaces of the cells;

the welding strip is used for connecting two adjacent solar cells so as to connect the plurality of solar cells into a string;

and the buffer layer is arranged on the edge of the solar cell, which is crossed with the solder strip, and is positioned between the solder strip and the cell surface facing the solder strip.

Wherein the edges of two adjacent solar cells are overlapped to form an overlapping space between the two adjacent solar cells, and the buffer layer is positioned in the overlapping space.

The buffer layer comprises a front buffer layer arranged on the front side of the solar cell and a back buffer layer arranged on the back side of the solar cell, and the front buffer layer and the back buffer layer are positioned on different side edges.

Wherein the buffer layer is fixed on the surface of the battery; preferably, the thickness of buffer layer is 200 ~ 400 um.

The buffer layer is long and extends along the edge, or the buffer layer includes n interval settings and with weld the buffer dish that takes the position to correspond, n is the solder strip quantity that solar cell unilateral surface set up.

Wherein the size of the buffer layer in the extending direction of the solder strip is larger than or equal to the size of the overlapping space in the extending direction of the solder strip.

Wherein the solder ribbon comprises a first section soldered to a front electrode of a solar cell, a second section soldered to a back electrode of another adjacent solar cell, and a transition section connecting the first and second sections, the transition section being disposed in the overlapping space, the width of the transition section being greater than the width of the first and/or second section; preferably, the first section and the second section overlap outside the overlapping space.

Wherein the buffer layer comprises ethylene-vinyl acetate copolymer EVA and/or polyolefin elastomer POE.

In another aspect, a photovoltaic module includes a plurality of cell strings, the cell strings including:

the edges of two adjacent solar cells are mutually overlapped to form an overlapping space between the two adjacent solar cells;

the solder strip is used for connecting two adjacent solar cells and passing through the overlapping space;

and the buffer layer is arranged in the overlapping space and is positioned between two adjacent parallel welding strips.

Wherein the solder strip comprises a first section soldered to the front electrode of the solar cell, a second section soldered to the back electrode of another adjacent solar cell, and a transition section connecting the first and second sections, the transition section being disposed in the overlapping space, and the buffer layer has a dimension in the cell thickness direction larger than that of the transition section.

The embodiment of the utility model provides a set up the buffer layer through the solar cell surface, can utilize this buffer layer to play the effect of alleviating the rigid contact between solar cell and the solder strip to photovoltaic module's lobe of a leaf rate has been reduced.

Drawings

Fig. 1A is a schematic diagram of an intersecting and stacking state of two adjacent solar cells suitable for a stacked assembly according to an embodiment of the present invention.

Fig. 1B is a schematic diagram of a connection state between two adjacent solar cells suitable for a conventional module according to an embodiment of the present invention.

Fig. 2 is a schematic view of a solder strip structure for connecting two adjacent solar cells according to an embodiment of the present invention.

Fig. 3 is a top view of a solar cell before being divided according to an embodiment of the present invention.

Fig. 4 is a top view of a solar cell before being divided according to an embodiment of the present invention.

Fig. 5 is a top view of a solar cell before being divided according to an embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view illustrating a cross-stacked state of solar cells according to an embodiment of the present invention.

Fig. 7 is a top view of a solar cell before being divided according to an embodiment of the present invention.

Fig. 8 is a schematic cross-sectional view (taken along the direction of the cutting line) of the cross-stacked state of the solar cells provided by the embodiment shown in fig. 7.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the aspects of the present invention are shown in the drawings, and other details not relevant to the present invention are omitted.

In addition, it is also to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

As shown in fig. 1A, the stacked solar cell is suitable for use in a stacked assembly in which two adjacent solar cells are stacked. The photovoltaic module comprises a plurality of battery strings, and the battery strings are generally in a straight line. The cell string comprises a plurality of solar cells 1 including, but not limited to, crystalline silicon cells or thin film cells, and solder ribbons 2 for connecting the plurality of solar cells 1 into a string (e.g., a series). Taking series connection as an example, two adjacent cells can be connected by n solder strips parallel to the main grid lines (electrodes) on the surface of the cell, where n is the number of the main grid lines arranged on the single-side surface of the solar cell.

In the laminated module, in order to increase the effective area of the cell on the module and improve the power and the module efficiency, the edges of the adjacent solar cells are overlapped to form an overlapping space between the two adjacent solar cells. The edge of the solar cell 1, which is intersected with the solder strip 2, is provided with a buffer layer 12, the buffer layer 12 is arranged in the overlapped space during the series welding of the cell, and the buffer layer 12 is positioned between the solder strip 2 and the surface of the solar cell 1, so that the problem of hard contact between the solder strip and the cell edge in the existing assembly is solved by avoiding the direct contact between the solder strip and the solar cell.

As shown in fig. 1B, the connection state of two adjacent solar cells is suitable for the conventional module. It can be seen that there may be some gap or close to zero gap between two adjacent solar cells in the conventional module. In the assembly, the buffer layer arranged at the edge of the battery is also suitable, and the problem of hard contact between the welding strip and the edge of the battery in the existing assembly is solved.

As shown in fig. 2, each solder ribbon may include a first segment 21 soldered to the front side busbar of one solar cell, a second segment 22 connected to the back side busbar of another solar cell adjacent thereto, and a transition segment 23 connecting the first and second segments 21 and 22. The solder strip includes, but is not limited to, a tin-plated copper strip or a tin-plated copper strip, and the shape of the solder strip is not limited.

In an embodiment of the present invention, the first section 21 may be a circular wire solder strip or a polygonal solder strip, so as to reduce the light shielding of the front side (i.e. the light receiving surface) of the battery piece; the second segment 22 may be a flat solder ribbon to match the wider back side of the cell grid lines, reducing resistance and increasing power. In view of the fact that different types of solder tapes are required to be used for the first section 21 and the second section 22, the first section 21 and the second section 22 may be two separate solder tapes, and during series welding, the first section 21 may be welded to the front surface of one cell piece, the second section 22 may be welded to the back surface of another cell piece, and then the ends of the first section 21 and the second section 22 are connected. Wherein, in actual production, the first section 21 and the second section 22 usually overlap outside the overlapping space.

In the laminated assembly, the transition section 23 is disposed in the overlapping space, and the width of the transition section 23 may be greater than the width of the first section 21 and/or the second section 22, so that the transition section 23 is substantially flat to increase the contact area between the transition section 23 and the object in contact in the overlapping space, further reducing the possibility of cell rupture at the position of the lamination. The flattened transition section 23 may be obtained by flattening a conventional solder strip in a certain direction.

In the photovoltaic module, a solar cell sheet having a regular size (substantially square shape) may be used as the solar cell, or a cell unit obtained by dividing a solar cell sheet having a regular size may be used. For convenience of description, the solar cell before division is defined herein as a "first solar cell".

As shown in fig. 3, the first solar cell surface 10 may be printed with a bus bar 15 and a thin bus bar (not shown) connected to the bus bar 15. A number of parallel cutting lines 17 are drawn on the first solar cell surface 10, the number of cutting lines depending on the number of strips to be divided. Taking 1-to-3 as an example, before the division, 3 parallel buffer layers may be disposed on the first solar cell surface 10, and the number of the buffer layers is consistent with the number of the cells divided by a single first solar cell. Wherein, the buffer layer can select the material that is lower than solder strip hardness, for example: ethylene-vinyl acetate copolymer EVA or polyolefin elastomer POE, etc. The process of forming the buffer layer is, for example: firstly, a layer of buffer material solvent is coated on the surface of the battery by a dropping or spin coating method, and then the solvent is removed by a baking method to leave unpolymerized buffer material on the surface of the battery to form a buffer layer. Of course, a solid buffer layer can be used and fixed at a specific position on the surface of the solar cell. The embodiment of the utility model provides an in, the thickness of buffer layer can be 200 ~ 400um to compromise buffering effect and material cost.

The first solar cell sheet is provided with a first edge 11 and a second edge 13 which are opposite and parallel, the surface 10 is provided with a first strip-shaped buffer layer 12a adjacent to the first edge 11 and a second strip-shaped buffer layer 12b adjacent to the second edge 13, the cutting line 17 is positioned between the first strip-shaped buffer layer 12a and the second strip-shaped buffer layer 12b, and a middle strip-shaped buffer layer 12c adjacent to the cutting line 17 is further arranged between the first strip-shaped buffer layer 12a and the second strip-shaped buffer layer 12 b. With this arrangement, the specific gravity of stacking two cut edges can be reduced, and the specific gravity of stacking a non-cut edge and a cut edge can be increased as much as possible, thereby improving the overall breakage rate of the assembly.

As shown in fig. 4, a first solar cell is cut into two halves to obtain two halves. Aiming at the design of the battery piece, a layer of buffer material is coated in the area of the battery piece lamination by a screen printing mode, the width of the buffer material can be 0.8mm, and then the solvent is removed by a low-temperature baking mode at 80-100 ℃, and the unpolymerized buffer material is left to be about 300 um.

In fig. 3 and 4, the buffer layer has an elongated shape and extends along the side of the first solar cell, but this way there is a certain waste of buffer material. For this purpose, an intermittent buffer layer design as shown in fig. 5 may be adopted, wherein a plurality of rows of intermittent buffer layers perpendicular to the bus bars are formed on the battery surface 10, each row of buffer layers may include n buffer disks 12d arranged at intervals and corresponding to the positions of the solder strips, and the size of the buffer disks 12d in the width direction of the bus bars may be greater than or equal to the width of the solder strips, so as to avoid direct contact between the transition sections located in the overlapping spaces and the battery surface.

As shown in fig. 1A and 6, in the cell string, adjacent first cells 1A and second cells 1b overlap, and the buffer layer 12 is located between the solder ribbon 2 and the surface of the solar cell provided with the electrode. Adjacent first and second cells 1a, 1b overlap, and a buffer layer 12 is located between the solder strip 2 and the surface of the solar cell on which the electrodes are provided. The buffer layer can comprise a front buffer layer arranged on the front side of the solar cell and a back buffer layer arranged on the back side of the solar cell, and the front buffer layer and the back buffer layer are positioned on different side edges. Of course, as another possible solution, the above buffer layer 12 may be provided only on one side surface edge of the solar cell.

The size of the buffer layer 12 in the extending direction of the solder strip may be larger than or equal to the size of the overlapping space in the extending direction of the solder strip, so as to ensure the buffering effect on the solder strip in the overlapping space, and of course the buffer layer may be a transparent material so as not to block light.

Referring to fig. 7 and 8, in another embodiment of the present invention, the single-row buffer layer may include a plurality of buffer portions 12e disposed at intervals and filled between two adjacent solder strips 2. The size of the buffer parts 12e in the thickness direction of the battery can be larger than that of the transition section in the thickness direction of the battery, so that a channel for the transition section to pass through is formed between two adjacent buffer parts 12e, and the hard contact between the transition section and the surface of the battery piece is relieved.

Correspondingly, the embodiment of the utility model provides a method of manufacturing above photovoltaic module.

As a first embodiment, the method may include steps S1 and S2, in which:

s1: the edge of the surface of the solar cell is provided with a buffer layer, and the surface is provided with an electrode.

S2: connecting a plurality of solar cells in a string by solder strips such that the buffer layer is located between the surface and the solder strips.

As a second embodiment, in order to obtain a laminated assembly, then based on the content of the above first embodiment, the method further includes step S3:

the edges of adjacent solar cells in the plurality of solar cells are overlapped with each other to form an overlapping space between the adjacent two solar cells.

As a third embodiment, in order to improve the assembly efficiency by reducing the area of the single cell, the conventional size cell needs to be divided, and then based on the above second embodiment, the step S1 may specifically include:

s101: providing a first solar cell to be divided, wherein the surface of the first solar cell is provided with an electrode.

S102: and forming a separation line on the surface of the first solar cell.

S103: and arranging a buffer layer on the surface of the first solar cell.

S104: and dividing the first solar cell into at least two cell strips along the dividing line, wherein the cell strips comprise buffer layers arranged along the long edges of the cell strips.

The first solar cell is provided with a first edge and a second edge which are opposite and parallel, a first strip-shaped buffer layer adjacent to the first edge and a second strip-shaped buffer layer adjacent to the second edge are arranged on the surface of the first solar cell, and the cutting line is located between the first strip-shaped buffer layer and the second strip-shaped buffer layer. This approach can minimize the proportion of the assembly where the two cutting edges overlap.

As a fourth embodiment, a manufacturing method of a photovoltaic module includes steps S1 and S3, in which:

s1: arranging a buffer layer at the edge of the surface of the solar cell, wherein the surface is provided with an electrode;

s3: connecting a plurality of solar cells into a string through solder strips, wherein the edges of adjacent solar cells in the plurality of solar cells are overlapped with each other to form an overlapping space for the solder strips to pass through between the adjacent two solar cells, and the buffer layer is positioned in the overlapping space and filled between the two adjacent solder strips.

In a more specific embodiment, the solder ribbon includes a first segment soldered to the front electrode of the solar cell, a second segment soldered to the back electrode of another adjacent solar cell, and a transition segment connecting the first and second segments, the transition segment being disposed in the overlapping space, and the buffer layer having a dimension in the cell thickness direction larger than a dimension of the transition segment in the cell thickness direction.

The above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A photovoltaic module comprises a plurality of battery strings and is characterized in that: the battery string includes:

the solar cells comprise electrodes arranged on the surfaces of the cells;

2. The photovoltaic module of claim 1, wherein: the edges of two adjacent solar cells are overlapped with each other to form an overlapping space between the two adjacent solar cells, and the buffer layer is positioned in the overlapping space.

3. The photovoltaic module of claim 1, wherein: the buffer layer includes the front buffer layer of locating the solar cell front and locates the back buffer layer of solar cell back to front buffer layer and back buffer layer are located different side reason.

4. The photovoltaic module of claim 1, wherein: the buffer layer is fixed in the battery surface, the thickness of buffer layer is 200 ~ 400 um.

5. The photovoltaic module of claim 1, wherein: the buffer layer is rectangular form and follows the edge extends, perhaps the buffer layer includes n interval settings and with weld the buffer disc that takes the position to correspond, n is the strip quantity that welds that solar cell unilateral surface set up.

6. The photovoltaic module of claim 2, wherein: the size of the buffer layer in the extending direction of the solder strip is larger than or equal to the size of the overlapping space in the extending direction of the solder strip.

7. The photovoltaic module of claim 2, wherein: the solder strip comprises a first section welded with the front electrode of the solar cell, a second section welded with the back electrode of another adjacent solar cell and a transition section connecting the first section and the second section, wherein the transition section is arranged in the overlapping space, the width of the transition section is larger than that of the first section and/or the second section, and the first section and the second section are overlapped outside the overlapping space.

8. The photovoltaic module of claim 1, wherein: the buffer layer comprises ethylene-vinyl acetate copolymer EVA and/or polyolefin elastomer POE.

9. A photovoltaic module comprises a plurality of battery strings and is characterized in that: the battery string includes:

10. The photovoltaic module of claim 9, wherein: the solder strip comprises a first section soldered to the front electrode of the solar cell, a second section soldered to the back electrode of another adjacent solar cell, and a transition section connecting the first section and the second section, the transition section being disposed in the overlapping space, and the buffer layer having a dimension in the cell thickness direction larger than that of the transition section.