WO2016157696A1

WO2016157696A1 - Solar cell module

Info

Publication number: WO2016157696A1
Application number: PCT/JP2016/000904
Authority: WO
Inventors: 和生太田; 亮治内藤; 村上　洋平; 裕幸神納
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2015-03-31
Filing date: 2016-02-19
Publication date: 2016-10-06
Also published as: JP2018142747A; JPWO2016157696A1; JP6532046B2; JP6365911B2

Abstract

A solar cell module (100) is provided with, in this order: a plurality of solar cell strings (10); an insulating sheet (80) formed from a resin sheet; and at least one of inter-string wiring material (30) electrically connecting the solar cell strings (10) to each other and electricity extraction wiring material (40) extending from the solar cell strings (10). The insulating sheet (80) is disposed so as to straddle adjacent solar cell strings (10), and the direction of the maximum expansion and contraction of the insulating sheet (80) is different from the direction in which the plurality of solar cell strings (10) is arranged.

Description

Solar cell module

The present invention relates to a solar cell module.

Solar cells are expected as a new energy source because they can directly convert clean and infinitely supplied solar energy into electrical energy.

Generally, a solar battery cell is a photoelectric conversion element having a thickness of about 200 μm, and its output per sheet is about several watts and is fragile. Therefore, when a solar cell is used as a power source for a house or a building, a solar cell module configured to increase output by electrically connecting a plurality of solar cells and protect the solar cells from impact. Is used. The solar cell module is configured as follows.

First, a solar cell string in which a plurality of solar cells are electrically connected in series using an inter-cell wiring material having conductivity is prepared. Subsequently, a plurality of solar cell strings are further electrically connected using an inter-string wiring material, and a power extraction wiring material connected to the terminal box is provided from the solar cell string arranged at the end of the solar cell module. The whole is sealed in a resin such as ethylene vinyl acetate copolymer (EVA), and further, glass or a composite resin sheet for protecting from impacts is disposed outside as a protective member.

Incidentally, there is a demand for a solar cell module to increase the amount of power generation per unit area. In view of this, an effort has been made to reduce the area of the solar cell module by arranging an interstring wiring material and a power extraction wiring material on the back side of the solar cell string. At this time, an insulating sheet for preventing a short circuit is disposed between the wiring members or between the wiring member and the solar cell string.

JP 2007-294866 A

The present invention provides a solar cell module with improved reliability.

A solar cell module according to an aspect of the present invention includes a plurality of solar cell strings, an insulating sheet made of a resin sheet, an interstring wiring material that electrically connects the solar cell strings, and power extraction extending from the solar cell string A solar cell module comprising at least one of the wiring members in this order, wherein the insulating sheet is disposed across the adjacent solar cell strings, and the maximum expansion and contraction direction of the insulating sheet is the plurality of solar cell strings. It is different from the arrangement direction.

According to the present invention, a solar cell module with improved reliability can be provided.

FIG. 1 is a layout diagram of solar cell modules according to the first embodiment. FIG. 2 is a plan view of the surface side of the solar cell module according to the first embodiment. FIG. 3 is a plan view of the back side of the solar cell module according to the first embodiment. FIG. 4 is a diagram illustrating a state of a resin sheet in a previous stage applied to the solar cell module. FIG. 5 is a layout diagram of solar cell modules according to the second embodiment. FIG. 6 is a plan view of the surface side of the solar cell module according to the third embodiment. FIG. 7 is a plan view of the back surface side of the solar cell module according to the third embodiment.

Embodiments according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[First Embodiment]
(Configuration of solar cell module)
FIG. 1 is a layout diagram of a solar cell module 100 according to the first embodiment. A plurality of solar cell strings 10 to be described later are protected from both front and back surfaces by

fillers

50a and 50b made of a resin sheet. Moreover, the solar cell module 100 is provided with the surface side protection board 60 which protects the filler 50a, and the back surface side protective material 70 which protects the filler 50b.

The material of the

fillers

50a and 50b is preferably selected from the group consisting of thermoplastic resins such as polyolefins, polyethylenes, polyphenylenes and copolymers thereof, or thermosetting resins.

Fillers

50a and 50b are cured by thermocompression bonding. In the present embodiment, as an example, a polyolefin resin is used for the filler 50a and an ethylene vinyl acetate copolymer (EVA) is used for the filler 50b, but the combination is not limited thereto.

It is desirable that the surface-side protection plate 60 is made of a material that has high light transmittance and is hard enough to protect the surface of the solar cell module 100 from falling objects. Although a resin material such as an acrylic plate may be used, tempered glass is used in this embodiment. Moreover, although the back surface side protection material 70 may be formed with a glass plate, an acrylic plate, etc. similarly to the surface side protection plate 60, the composite resin sheet with high weather resistance may be used. In this embodiment, a composite resin sheet based on polyethylene terephthalate (PET) is used.

Since the schematic configuration of the solar cell module 100 described above is common to all the first to third embodiments, description thereof will be omitted in the following embodiments.

FIG. 2 is a plan view of the surface side of the solar cell module 100 according to the first embodiment. As shown in FIG. 2, the solar cell module 100 includes a plurality of solar cell strings 10 in which a plurality of solar cells are connected in series by inter-cell wiring members 20. The plurality of solar cell strings 10 are electrically connected by the inter-string wiring member 30, and the power extraction wiring member 40 extends from the solar cell string located at the end of the solar cell module 100. In the solar cell module 100, the inter-string wiring member 30 and the power extraction wiring member 40 are disposed on the back side of the solar cell string 10.

FIG. 3 is a plan view of the back side of the solar cell module 100 according to the first embodiment. Note that FIG. 3 does not show parts unnecessary for describing the features of the present embodiment.

When the solar cell module 100 is viewed from the back side, a plurality of solar cell strings 10 are electrically connected using inter-string wiring members 30 as shown in FIG. Furthermore, in order to extract electric power from the plurality of solar cell strings 10 and connect it to a terminal box (not shown), an electric power extraction wiring member 40 extends from the solar cell string 10 at the end of the solar cell module 100. .

Here, the inter-string wiring member 30 and the power extraction wiring member 40 are arranged at positions overlapping the solar cell string. For this reason, the inter-string wiring member 30 and the power extraction wiring member 40 and the solar cell string 10 are not connected to each other so that the inter-string wiring member 30 and the power extraction wiring member 40 and the solar cell string 10 do not short-circuit. An insulating sheet 80 made of a resin material is disposed.

The insulating sheet 80 is not particularly limited as long as it is a soft material made of an insulator, but is preferably a thin composite resin sheet made of PET, polyethylene or the like. In this embodiment, a composite resin sheet having a PET film as a base material is used. In addition, it is preferable that the width | variety of the insulating sheet 80 is narrower than one solar cell.

(Arrangement form of insulating sheet 80)
FIG. 4 is a diagram illustrating a state of a resin sheet in a previous stage applied to the solar cell module. The composite resin sheet is wound into a single roll while being pulled strongly in the final stage of the manufacturing process, and then molded using a technique such as cutting or punching. At this time, the direction of winding is called MD (Machine Direction), and the direction perpendicular to MD is called TD (Transverse Direction).

In the resin sheet produced by such a method, the stretching stress in the MD direction is inherent. When such a resin sheet expands and contracts due to heat, the expansion rate in the MD direction is larger than the expansion rate in the TD direction. Therefore, in the present specification, this MD direction is defined as a “maximum expansion / contraction direction”. The winding direction of the resin sheet can also be measured by confirming the orientation of the molecules in the resin using a chemical analysis technique.

When the insulating sheet 80 made of a composite resin sheet is disposed for the purpose of insulating the solar cell string 10 from the inter-string wiring member 30 and the power extraction wiring member 40, in the manufacturing process of the solar cell module 100, the filler 50a and When the 50b is thermocompression bonded, the insulating sheet 80 may be deformed or stretched.

The inventor of the present application has found that when the insulating sheet 80 is arranged so as to satisfy a specific condition, the insulating sheet 80 contracts and the interval between the solar cell strings 10 is narrowed. By narrowing the space between the solar cell strings 10, the contact between the solar cells constituting the solar cell string 10, that is, the risk of a short circuit increases. That is, the present embodiment is a configuration for reducing the risk of short-circuiting of the solar cell string 10 due to the shrinkage of the insulating sheet 80.

From the above viewpoint of reducing the short circuit risk of the solar cell string 10, in the first embodiment, the insulating sheet 80 is disposed as shown in FIG. That is, the insulating sheet 80 is arranged so that the arrangement direction (x direction) of the solar cell strings 10 and the maximum expansion / contraction direction of the insulating sheet 80 do not coincide. Specifically, in FIG. 3, when the x direction is the arrangement direction of the plurality of solar cell strings 10, the insulating sheet 80 is arranged so that the maximum expansion / contraction direction of the insulating sheet 80 is the y direction. That is, the arrangement direction of the solar cell strings 10 and the maximum expansion / contraction direction of the insulating sheet 80 are orthogonal to each other.

When the maximum expansion / contraction direction of the insulating sheet 80 is orthogonal to the arrangement direction of the solar cell strings 10, the expansion / contraction amount of the insulating sheet 80 in the x direction can be reduced. By reducing the amount of expansion and contraction of the insulating sheet 80 in the x direction, the space between the solar cell strings 10 disposed so as to be in contact with the insulating sheet 80 is suppressed, so that the solar cell string 10 is configured. The possibility of a short circuit between solar cells can be reduced.

In the present embodiment, the term “perpendicular” between the arrangement direction of the solar cell strings 10 and the maximum expansion / contraction direction of the insulating sheet 80 indicates a range of about 90 ° ± 10 °. If the arrangement direction of the solar cell strings 10 and the maximum expansion / contraction direction of the insulating sheet 80 are not matched, the amount of expansion / contraction in the y direction can be reduced as compared with the case where they match. effective. In order to have a certain effect, the crossing angle range between the arrangement direction of the solar cell strings 10 and the maximum expansion / contraction direction of the insulating sheet 80 should be 90 ° ± 45 °. preferable.

In addition, when the width | variety of the insulating sheet 80 is narrower than one solar cell, even when the insulating sheet 80 contracts, it is electrically connected by the solar cell in contact with the insulating sheet 80 and the wiring material. The distance between the connected solar cells is not reduced. Therefore, the possibility of contact between the solar cells in the maximum expansion / contraction direction of the insulating sheet 80 is extremely small.

[Second Embodiment]
FIG. 5 is a layout diagram of the solar cell module 200 according to the second embodiment. The schematic configuration of the solar cell module 200, the arrangement of the solar cell string 10, the positional relationship between the solar cell string 10 and the inter-string wiring member 30, and the positional relationship between the solar cell string 10 and the power extraction wiring member 40 are as follows. Since this is the same as the first embodiment, the description thereof is omitted.

In 2nd Embodiment, about the resin sheet which comprises the solar cell module 200, in addition to the arrangement | positioning direction of the insulating sheet 80, resin sheets other than the insulating sheet 80, ie, arrangement | positioning of the

fillers

50a and 50b, and the back surface side protective material 70 The direction is fixed.

In this embodiment, the

fillers

50a and 50b for sealing the solar cell string 10 and the back surface side protective material 70 are all resin sheets molded through a manufacturing process similar to the insulating sheet 80, and are in the MD direction. The stretching stress is inherent. At this time, as shown in FIG. 5, the respective resin sheets are arranged so that the extending direction of the solar cell string 10 and the maximum expansion / contraction direction (MD direction) of each resin sheet are orthogonal to each other. That is, referring to the coordinates in FIG. 5, the solar cell string 10 extends in the y direction, and the plurality of solar cell strings 10 are arranged in the x direction. At this time, the maximum expansion / contraction direction of the

fillers

50a and 50b and the back surface side protection member 70 is the x direction, and the maximum expansion / contraction direction of the insulating sheet 80 is the y direction.

As described above, the solar cell string 10 has a configuration in which a plurality of solar cells are connected in series using the inter-cell wiring member 20. The extending direction of the solar cell string 10 is the same as the length direction of the inter-cell wiring member 20. By using the solar cell module outdoors, the solar cell module 200 undergoes a thermal cycle. Due to this thermal cycle, the

fillers

50a and 50b once heat-cured also expand and contract slightly, and the interval between the solar cells constituting the solar cell string 10 increases or decreases.

Since most of the length of the inter-cell wiring member 20 is electrically and physically connected to the solar cells and is fixed, when the interval between the solar cells changes, the inter-cell wiring member 20 The portion not connected to the solar battery cell is bent. If the bending of the inter-cell wiring member 20 is repeated over a long period of time, the risk that the inter-cell wiring member 20 is deteriorated due to metal fatigue increases.

In the present embodiment, in order to suppress deterioration due to metal fatigue of the inter-cell wiring member 20, the maximum expansion / contraction direction of the

fillers

50a and 50b and the back surface side protection member 70 is defined as the extending direction of the solar cell string 10, that is, the cell. The direction perpendicular to the length direction of the intermediate wiring member 20 (x direction) is used. On the other hand, the maximum expansion / contraction direction of the insulating sheet 80 is the y direction as described above. With such a configuration, the stretching stress in the extending direction of the solar cell string 10, that is, the length direction of the inter-cell wiring member 20, is alleviated, and the reliability of the solar cell module 200 is further increased.

In the second embodiment, the maximum expansion / contraction directions of the

fillers

50a and 50b and the back surface side protective material 70 are all perpendicular to the length direction of the inter-cell wiring member 20, This arrangement method may be selected for at least one of the

materials

50 a and 50 b and the back surface side protective material 70. This also has the effect that the stretching stress in the length direction of the inter-cell wiring member 20 is relaxed. That is, the maximum expansion / contraction direction and the length direction of the inter-cell wiring member 20 may be different only for one type or two types of the

fillers

50 a and 50 b and the back surface side protective material 70.

[Third Embodiment]
FIG. 6 is a plan view of the surface side of the solar cell module 300 according to the third embodiment. The schematic configuration of the solar cell module 300 is the same as that of the first embodiment, and the arrangement direction of the

fillers

50a and 50b and the back surface side protective material 70 is the same as that of the second embodiment, and thus the description thereof is omitted.

FIG. 7 is a plan view of the back side of the solar cell module 300 according to the third embodiment. In FIG. 7, parts unnecessary for explaining the features of the present embodiment are not shown.

In this embodiment, the positional relationship between the solar cell string 10 and the inter-string wiring member 31 and the positional relationship between the solar cell string 10 and the power extraction wiring member 41 are as shown in FIGS. That is, as can be seen from FIG. 6 and FIG. 7, in this embodiment, the inter-string wiring member 31 is arranged at a position that does not overlap the solar battery string 10, and the power extraction wiring member 41 is on the back surface side of the solar battery cell. Has been placed.

The solar battery cell is a thin and fragile component as described above. Therefore, when the solar battery string 10 is sandwiched between the

fillers

50a and 50b and heated under pressure to cure the

fillers

50a and 50b, there should be as little irregularities or steps as possible on the front and back sides of the solar cells. Good. For this reason, the connecting portion between the inter-string wiring member 31 and the inter-cell wiring member 20, which tend to have many connecting portions, is arranged so as not to overlap the solar battery cell. Thereby, the production yield of the solar cell module 300 can be kept high while increasing the amount of power generation per area of the solar cell module 300.

In addition, after the inter-string wiring member 31 is disposed at a position not overlapping with the solar cell string 10 and the power extraction wiring member 41 is disposed on the back surface side of the solar cell string 10, insulation is performed as in the first embodiment. Only the arrangement direction of the sheet 81 may be limited. Furthermore, tempered glass, an acrylic plate, or the like may be used for the back surface side protective material 70 instead of the composite resin sheet.

In the first to third embodiments, the method for connecting the inter-cell wiring member 20 to the solar battery cell is not particularly limited. Specifically, it may be connected by soldering using a copper inter-cell wiring material having a structure in which a copper core wire is solder-coated. In addition, a solder-coated copper inter-cell wiring material or a copper inter-cell wiring material without solder coating may be prepared and connected to the solar battery cell using a resin adhesive.

The outer shape of the solar cell module according to the first to third embodiments is a rectangle having a long side and a short side when the solar cell string 10 is viewed in plan (when viewed from the XY plane). And the arrangement direction of the plurality of solar cell strings 10 may be orthogonal to each other.

DESCRIPTION OF SYMBOLS 10 Solar cell string 20

Inter-cell wiring material

30, 31

Inter-string wiring material

40, 41 Power

extraction wiring material

50a, 50b Filler 60 Front surface side protective plate 70 Back surface side

protective material

80, 81 Insulating

sheet

100, 200, 300 Solar cell module

Claims

A plurality of solar cell strings;
An insulating sheet made of a resin sheet;
A solar cell module comprising, in this order, at least one of an interstring wiring material that electrically connects each of the plurality of solar cell strings and a power extraction wiring material that extends from the plurality of solar cell strings,
The insulating sheet is disposed across adjacent solar cell strings,
A maximum expansion / contraction direction of the insulating sheet is different from an arrangement direction of the plurality of solar cell strings.
The solar cell module according to claim 1, wherein a maximum expansion / contraction direction of the insulating sheet is orthogonal to an arrangement direction of the plurality of solar cell strings.
When the plurality of solar cell strings are viewed in plan, the planar shape of the solar cell module is a rectangle having a long side and a short side,
The solar cell module according to claim 2, wherein a direction of the long side and an arrangement direction of the plurality of solar cell strings are orthogonal to each other.