CN211017100U

CN211017100U - Component of crystal silicon solar cell string

Info

Publication number: CN211017100U
Application number: CN201921580529.XU
Authority: CN
Inventors: 杨振英; 卢刚; 郑璐; 马冀超; 杨紫琪; 雷鸣宇; 陈燕; 海建平
Original assignee: Yellow River Hydropower Photovoltaic Industry Technology Co ltd; Qinghai Huanghe Hydropower Development Co Ltd; Huanghe Hydropower Development Co Ltd; Photovoltaic Industry Technology Branch of Qinghai Huanghe Hydropower Development Co Ltd
Current assignee: Yellow River Hydropower Photovoltaic Industry Technology Co ltd; Qinghai Huanghe Hydropower Development Co Ltd; Huanghe Hydropower Development Co Ltd; State Power Investment Corp Ltd Huanghe Hydropower Development Co Ltd; Photovoltaic Industry Technology Branch of Qinghai Huanghe Hydropower Development Co Ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2020-07-14
Anticipated expiration: 2029-09-20

Abstract

The utility model relates to a component of a crystal silicon solar cell string, which adopts the splicing technology of two adjacent batteries, shortens the space between solar cells inside the component, reduces the blank inside the component in the packaging of components with the same specification, increases the using quantity of the batteries and greatly improves the conversion efficiency of the component; due to the use of the triangular welding strip on the front surface of the cell, the sunlight absorption rate of the crystalline silicon solar cell is effectively improved, and the short-circuit current of the cell is improved; the use of the flat welding strip on the back of the cell reduces the stress when adjacent cells are connected in series, and reduces the subfissure and fragment rate of the solar cell in the processes of series connection and lamination. In a word, adopt the utility model discloses when carrying out the encapsulation of crystal silicon solar cell module, when promoting subassembly power, conversion efficiency, production efficiency and reduction subassembly preparation cost, greatly reduced among the subassembly packaging process battery because of the stress that is heated and produces, reduced the probability that the hidden crack appears and split, improved the subassembly reliability when extension crystal silicon solar cell module life cycle.

Description

Component of crystal silicon solar cell string

Technical Field

The utility model relates to a subassembly of crystal silicon solar cell cluster belongs to crystal silicon solar cell and makes technical field.

Background

The technical innovation is the most effective method for promoting the efficiency enhancement, cost reduction and quality improvement of the photovoltaic industry. Innovative packaging technologies such as half-chip technology, double-glass technology, multi-master-grid technology and lamination technology are developed in the assembly preparation links in the last two years. Particularly, the lamination technology greatly reforms the interconnection technology of the assembly, makes full use of the inter-chip distance in the original packaging mode, and achieves a new level for effectively utilizing the battery and other packaging materials.

At present, the interconnection mode of the cells in the preparation of the crystalline silicon solar module can be largely divided into two modes, one mode is a welding strip connection mode, and the other mode is a welding strip-free connection mode. The welding strip connection mode can be divided into a flat welding strip interconnection technology and a circular welding strip interconnection technology according to different shapes of the welding strips; the solderless strip connection method is such as lamination technology, back contact connection technology and the like.

In a welding strip connection mode, the front side and the back side of the battery are connected by adopting flat welding strips, the mass production scale is the largest, the application is the most extensive and the process is mature at present, the flat welding strips used on the front side of the battery can shield a part of the light receiving area of the solar battery and have a reflection effect on incident sunlight, so that the utilization of the sunlight at the welding strip position is insufficient; taking the conventional 5BB solar cell in series connection as an example, the connection method of 5 flat welding strips with rectangular sections enables about 3% of the area of the front surface of the solar cell to be shielded by the flat welding strips, and most of the light is wasted due to the reflection principle of the flat welding strips to the light; the back of the battery adopts a flat welding strip with the thickness consistent with that of the front, the thickness is generally 0.20-0.25 mm, and the thermal stress received by the battery is large when the battery is heated due to the yield strength of the welding strip during welding of the battery, so that the problems of hidden cracking and splitting of the solar battery are easily caused. The circular welding strip connection mode improves the utilization rate of incident light to a certain extent, but most of the incident light is reflected to the interface of the glass and the air, the incident light returns to the surface of the cell after being totally reflected on the interface, and the absorption rate of the glass and the EVA to the light is as high as 1.45% and 1.79%, so that little sunlight which can really generate photoproduction current after being reflected for many times is generated.

The existing mature technology in the solderless strip connection mode is a lamination technology, the lamination wastes more solar cells, the 66 plate type assemblies and adjacent cells are calculated by the overlapping width of 1.0mm, the area of the wasted cells of the overlapping parts is equivalent to 2.5 solar cells, namely, the number of the solar cells which can actually and effectively generate electricity is only 3.5 because the number of the 6 solar cells which are subjected to white leaving and multiple packaging in the assemblies is reduced; another back contact connection technique without solder ribbon connection is currently being applied to a large scale due to the high cost of manufacturing the cells and components.

Disclosure of Invention

The to-be-solved technical problem of the utility model is: the problem of how to increase the sunlight utilization ratio of solder strip department under the condition of not increasing cost is solved.

In order to solve the technical problem, the technical solution of the present invention is to provide a crystalline silicon solar cell string assembly, which is characterized by comprising a plurality of crystalline silicon solar cell strings sequentially subjected to typesetting, laminating and packaging; each crystalline silicon solar cell string comprises a plurality of crystalline silicon solar cells, and any two adjacent crystalline silicon solar cells are connected through a triangular welding strip on the front side of each crystalline silicon solar cell and a flat welding strip on the back side of each crystalline silicon solar cell to form the crystalline silicon solar cell string.

Preferably, the triangular welding strip is a triangular narrow tinned welding strip made of a tinned copper strip, the melting point of the tinned copper strip is 140-220 ℃, and the side length of a triangle of the triangular welding strip is 0.35-0.55 mm.

Preferably, the flat welding strip is a flexible ultrathin flat tinned welding strip made of a tinned copper strip, the melting point of the flexible ultrathin flat tinned welding strip is 140-220 ℃, the thickness of the flat welding strip is 0.5-0.9 mm, and the width of the flat welding strip is 1.0-2.0 mm.

Preferably, the distance between two adjacent crystalline silicon solar cells is 0.3-1.0 mm.

The utility model discloses use triangle-shaped to weld the area and the back uses the connected mode of flexible ultra-thin flat solder strip at the battery openly both continue to use flat solder strip contact resistance low advantage, remedied again flat solder strip and leaded to the defect that the utilization ratio is low to incident light reflection. By using the welding strip with the triangular interface, the shielding area is reduced, the light at the welding strip is secondarily utilized, and finally, the light at the welding strip is wasted by only 20% when the flat welding strip is used for connecting the 5BB solar cell; the ultra-soft and ultra-thin flat welding strip is adopted on the back of the cell, so that the welding stress can be effectively reduced, the stress unevenness during welding and the cold and hot expansion stress of the welding strip after welding can be eliminated, the probability of hidden cracks and fragments of the cell during interconnection welding of the cell can be reduced, and the solar cell packaging method is more suitable for the thin solar cell packaging development trend in the future photovoltaic industry; meanwhile, a glue film material with smaller gram weight can be used in the packaging of the component, so that the preparation cost of the component can be effectively reduced; in addition, the triangular welding strip splicing method is adopted, the blank in the assembly is reduced, the triangular welding strip is used on the front side, incident light is irradiated on the surface of the triangular welding strip and then is totally reflected to the surface of the battery, and few light rays enter the naked eyes of an observer, so that the triangular welding strip has a hidden effect in vision, and the appearance of the assembly is more attractive and elegant.

The utility model discloses openly adopt the cross-section to be triangle-shaped's narrow tin-plating solder strip (hereinafter for short triangle solder strip), the back adopts flexible ultra-thin flat tin-plating solder strip (hereinafter for short flat solder strip), realizes two adjacent crystal silicon solar cell's interconnection, forms crystal silicon solar cell cluster.

Due to the adoption of the technology of splicing two adjacent batteries, the space between the batteries in the battery string can be controlled to be 0.3-1.0 mm, the space between the solar batteries in the assembly is shortened, the blank space in the assembly is reduced in the assembly packaging with the same specification, the use number of the batteries is increased, and the conversion efficiency of the assembly is greatly improved; due to the use of the triangular welding strip on the front surface of the cell, the sunlight absorption rate of the crystalline silicon solar cell is effectively improved, and the short-circuit current of the cell is improved; the use of the flat welding strip on the back of the cell reduces the stress when adjacent cells are connected in series, and reduces the subfissure and fragment rate of the solar cell in the processes of series connection and lamination. In a word, adopt the utility model discloses when carrying out the encapsulation of crystal silicon solar cell module, when promoting subassembly power, conversion efficiency, production efficiency and reduction subassembly preparation cost, greatly reduced among the subassembly packaging process battery because of the stress that is heated and produces, reduced the probability that the hidden crack appears and split, improved the subassembly reliability when extension crystal silicon solar cell module life cycle.

Drawings

FIG. 1 is a schematic diagram of a pattern printing scheme of a crystalline silicon solar cell;

FIG. 2 is a schematic view of adjacent solar cells spliced together;

FIG. 3 is a cross-sectional view of a fillet weld fillet;

FIG. 4 is a cross-sectional view of the ribbon.

Detailed Description

In order to make the present invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

A splicing method of crystal silicon solar cell strings comprises the following steps:

as shown in fig. 1, a crystalline silicon solar cell is prepared according to a crystalline silicon solar cell printing pattern scheme for standby; and (3) setting the welding parameters of the crystalline silicon solar cell string on an operation interface of the automatic string welding machine, and starting all systems on the string welding machine to start welding. Placing front side conductive materials (namely triangular welding strips) of the front two crystalline silicon solar cells 3 on a welding table, placing the first crystalline silicon solar cell 3 on the triangular welding strips with the front side facing downwards to ensure that a main grid of the crystalline silicon solar cell 3 is aligned with the triangular welding strips, placing back side conductive materials of the first crystalline silicon solar cell 3, placing the second crystalline silicon solar cell 3, and then placing front side conductive materials of the third crystalline silicon solar cell 3 and back side conductive materials of the second crystalline silicon solar cell 3. And analogizing in sequence, placing the set crystalline silicon solar cell string, transferring the crystalline silicon solar cell string to a welding station for welding, and realizing interconnection of adjacent crystalline silicon solar cells in the crystalline silicon solar cell string.

And typesetting and laminating a plurality of crystalline silicon solar cell strings, and packaging into the crystalline silicon solar cell component with high conversion efficiency and beautiful appearance.

In the pattern printing scheme of the crystalline silicon solar cell, the printing of the thin grid lines of the solar cell adopts an anti-breaking grid 1 and the thin grid lines 2 connected with a main grid line section adopt a gradual width scheme, the gradual width range is 15-30 mu m, and the solar cell can be a whole piece or a half piece; the splicing method of the adjacent solar cells comprises the following steps: the front surface of the crystalline silicon solar cell 3 adopts a triangular welding strip 4 with a triangular cross section, and the back surface of the crystalline silicon solar cell adopts a flexible ultrathin flat welding strip 5, so that the interconnection of two adjacent crystalline silicon solar cells 3 is realized, and a crystalline silicon solar cell string is formed; the distance between two adjacent solar cells 3 is 0.3-1.0 mm; the front conductive material spliced by the adjacent solar cells is a triangular solder strip 4 made of a tinned copper strip, the melting point of the triangular solder strip is 140-220 ℃, and the side length of a triangle is 0.35-0.55 mm; the back conductive material spliced by the adjacent solar cells is a flat welding strip 5, the material is a tinned copper strip, the melting point of the flat welding strip is 140-220 ℃, the thickness of the flat welding strip is 0.5-0.9 mm, and the width of the flat welding strip is 1.0-2.0 mm; the surfaces of the front and back conductive materials are uniformly distributed tin-containing coatings, and the melting point of the tin-containing coatings is 140-220 ℃.

Claims

1. A module of a crystalline silicon solar cell string is characterized by comprising a plurality of crystalline silicon solar cell strings which are sequentially subjected to typesetting, laminating and packaging; each crystalline silicon solar cell string comprises a plurality of crystalline silicon solar cells (3), and any two adjacent crystalline silicon solar cells (3) are connected through a triangular welding strip on the front side of each crystalline silicon solar cell (3) and a flat welding strip on the back side of each crystalline silicon solar cell (3) to form the crystalline silicon solar cell string.

2. The crystalline silicon solar cell string assembly as defined in claim 1, wherein the fillet solder is a triangular narrow tin-plated solder strip made of a tin-plated copper strip, the melting point of the tin-plated copper strip is 140-220 ℃, and the side length of the triangle of the fillet solder strip is 0.35-0.55 mm.

3. The crystalline silicon solar cell string assembly of claim 1, wherein the ribbon solder is a flexible ultra-thin ribbon solder made of tinned copper tape, the melting point is 140-220 ℃, the thickness of the ribbon solder is 0.5-0.9 mm, and the width of the ribbon solder is 1.0-2.0 mm.

4. The crystalline silicon solar cell string component as claimed in claim 1, wherein the spacing between two adjacent crystalline silicon solar cells (3) is between 0.3 mm and 1.0 mm.