KR20130011116A

KR20130011116A - Solar cell module

Info

Publication number: KR20130011116A
Application number: KR1020110072030A
Authority: KR
Inventors: 이채용; 김병수; 홍세은; 양혜영; 김화년; 이영식
Original assignee: 엘지전자 주식회사
Priority date: 2011-07-20
Filing date: 2011-07-20
Publication date: 2013-01-30

Abstract

PURPOSE: A solar cell module is provided to prevent the output degradation of the solar cell module due to a voltage drop in a lead line by efficiently reducing the lengths of a first lead line and a second lead line. CONSTITUTION: A solar cell panel includes a first outer string, a second outer string, and two inner strings. Interconnectors(220a-220f) electrically connect a plurality of solar cells(210) in each string. A first terminal box includes a first bypass diode which is electrically connected to the interconnector of the first outer string. A second terminal box includes a second bypass diode which is electrically connected to the interconnector of the second outer string. A third terminal box includes a third bypass diode which is electrically connected to the interconnector of the inner strings.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module, and more particularly to a solar cell module having a separate branch device.

With the recent prediction of the depletion of existing energy resources such as oil and coal, the interest in alternative energy to replace them is increasing, and solar cells producing electric energy from solar energy are attracting attention.

The photovoltaic power generation system is formed by connecting a plurality of solar cell modules in series or in parallel, and each solar cell module includes a plurality of solar cells arranged in a plurality of strings. Here, the string refers to a string formed by connecting a plurality of solar cells arranged in series.

Each solar cell module is provided with a branching device, such as a junction box, for drawing power generated from a plurality of solar cells to an external system, and in series or parallel with a neighboring solar cell module by a cable connected to the terminal box. Connected.

The present invention provides a solar cell module having a separate branch device.

The solar cell module according to one aspect of the invention has a branching device such that a first current, for example a positive current, is collected in the first terminal box and a second current, for example a negative current, is collected in the second terminal box. Is separated.

In one embodiment of the present invention, a solar cell module includes a first outer string and a second outer string spaced apart by a certain distance, and at least two inners positioned between the first and second outer strings. A solar cell panel including an inner string; An interconnector for electrically connecting the plurality of solar cells in each string; A first terminal box including a first bypass diode electrically connected to the interconnector of the first outer string; A second terminal box including a second bypass diode electrically connected to an interconnector of a second external string; And a third terminal box including a third bypass diode electrically connected to the interconnectors of the inner strings, wherein the first bypass diode and the second bypass diode are electrically connected to the third bypass diode, respectively.

The solar cell panel includes a first region in which a plurality of strings are positioned and a second region located at an edge of the first region, and the first to third terminal boxes are located in the second region.

The interconnector of the first external string and the first bypass diode are electrically connected by a first lead wire, and the interconnector of the second bypass diode and the second external string is electrically connected by a second lead wire. The first bypass diode and the third bypass diode are electrically connected by the third lead wire, and the third bypass diode and the second bypass diode are electrically connected by the fourth lead wire.

The first to fourth lead wires are located in the second area and include interconnector connection portions and terminal box connection portions, respectively.

In this case, the interconnector connecting portions of the first to fourth lead wires are arranged in a straight line in a direction crossing the plurality of strings.

The first lead wire and the second lead wire each have one terminal box connection part, and the third lead wire and the fourth lead wire each have two terminal box connection parts, and the terminal box connection parts of the first to fourth lead wires each include a plurality of strings. Are arranged in a direction parallel to the.

According to this aspect, the first bypass diode of the first terminal box is connected to the interconnector of the first external string by the first lead wire and the third bypass diode of the third terminal box by the third lead wire. In this case, the third lead wire electrically connects the interconnectors of the at least two inner strings adjacent to the first outer string.

Similarly, the second bypass diode of the second terminal box is connected to the interconnector of the second external string by the second lead wire, and the third bypass diode of the third terminal box is connected by the fourth lead wire. In this case, the fourth lead wire electrically connects the interconnectors of the at least two inner strings adjacent to the second outer string.

Thus, the first terminal box can be arranged in a position adjacent to the first outer string, and likewise the second terminal box can be arranged in a position adjacent to the second outer string.

According to this configuration, since the length of the first lead wire and the second lead wire can be effectively reduced, the output deterioration of the solar cell module due to the voltage drop generated in the lead wire can be prevented.

In addition, since the length of the cable electrically connecting the first terminal box to the second terminal box of the neighboring solar cell module can be reduced, it is possible to prevent the output degradation of the solar cell module due to the voltage drop generated in the cable.

In addition, since the first to fourth lead wires are positioned in the second region of the solar cell panel, it is not necessary to use an insulating tube or an insulating film for insulating the lead wires with the solar cells. Therefore, it is possible to prevent a decrease in reliability due to damage of the insulating tube or the insulating film.

In addition, since one terminal box includes only one bypass diode, the heat dissipation effect is excellent compared to the case where the plurality of bypass diodes are provided in one terminal box, thereby ensuring the reliability of the solar cell module.

1 is a plan view of a solar cell module according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the solar cell panel shown in FIG. 1.
3 is a rear view of the solar cell panel shown in FIG. 1.
4 is an enlarged view of a main part of the solar cell panel illustrated in FIG. 3.
5 is a perspective view of an essential part of the solar cell shown in FIG. 1.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention in the drawings, portions not related to the description are omitted, and like reference numerals are given to similar portions throughout the specification.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. When a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case directly above another portion but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

An embodiment of the present invention will now be described with reference to the accompanying drawings.

1 is a plan view of a solar cell module according to a first embodiment of the present invention, Figure 2 is an exploded perspective view of the solar cell panel shown in FIG. 3 is a rear view of the solar cell panel illustrated in FIG. 1, FIG. 4 is an enlarged view of an essential part of the solar cell panel illustrated in FIG. 3, and FIG. 5 is a perspective view of an essential part of the solar cell illustrated in FIG. 1.

Referring to the drawings, the solar cell module 100 according to the embodiment of the present invention includes a solar cell panel 200.

The solar cell panel 200 includes a plurality of solar cells 210, an interconnector 220 electrically connecting adjacent solar cells 210, and a protective film (EVA) to protect the solar cells 210 (EVA). 230, a transparent member 240 disposed on the passivation layer 230 toward the light receiving surface of the solar cells 210, and a back sheet 250 made of an opaque material disposed under the passivation layer 230 opposite to the light receiving surface. ).

The solar cell module 100 includes a frame 300 for accommodating the components integrated by a lamination process and a junction box for collecting electric power produced by the solar cells 210.

The back sheet 250 protects the solar cell 210 from the external environment by preventing moisture from penetrating at the rear of the solar cell module 100. The back sheet 250 may have a multilayer structure such as a layer for preventing moisture and oxygen penetration, a layer for preventing chemical corrosion, and a layer having insulation properties.

The protective film 230 is integrated with the solar cells 210 by a lamination process in a state disposed on the upper and lower portions of the solar cells 210, respectively, to prevent corrosion due to moisture penetration and to impact the solar cell 210. Protect from The passivation layer 230 may be made of a material such as ethylene vinyl acetate (EVA).

The transparent member 240 positioned on the passivation layer 230 is made of tempered glass having high transmittance and excellent breakage prevention function. In this case, the tempered glass may be a low iron tempered glass having a low iron content. The transparent member 240 may be embossed with an inner surface in order to enhance the light scattering effect.

As shown in FIG. 5, the solar cell 210 provided in the solar cell panel 200 according to the present embodiment includes an emitter part 212 positioned on a light receiving surface of a substrate 211 and a substrate 211 into which light is incident. The plurality of first electrodes 213 positioned on the emitter portion 212, the at least one first current collector 214 positioned on the emitter portion 212 in a direction crossing the first electrodes 213, and the first The anti-reflection film 215 positioned on the emitter portion 212 where the electrode 213 and the first current collector 214 are not located, the second electrode 216 and the second current collector (located on the opposite side of the light receiving surface) 217).

The solar cell 210 may further include a back surface field (BSF) portion formed between the second electrode 216 and the substrate 211. The backside electric field is a region in which impurities of the same conductivity type as the substrate 211 are doped at a higher concentration than the substrate 211, for example, a p + region.

The rear electric field serves as a potential barrier at the rear of the substrate 211. Therefore, the electrons and holes are recombined and extinguished in the rear side of the substrate 211, thereby improving the efficiency of the solar cell.

The substrate 211 is a semiconductor substrate made of silicon of a first conductivity type, for example, a p-type conductivity. In this case, the silicon may be monocrystalline silicon, polycrystalline silicon, or amorphous silicon. When the substrate 211 has a p-type conductivity type, it contains impurities of trivalent elements such as boron (B), gallium (Ga), indium (In), and the like.

The substrate 211 may be texturized to form the surface of the substrate 211 as a texturing surface. When the surface of the substrate 211 is formed as a texturing surface, the light reflectance at the light receiving surface of the substrate 211 is reduced, and incident and reflection operations are performed on the texturing surface to trap light in the solar cell, thereby increasing light absorption. . Thus, the efficiency of the solar cell is improved.

The emitter portion 212 is a region doped with impurities having a second conductivity type that is opposite to the conductivity type of the substrate 211, for example, an n-type conductivity type, and includes a substrate 211 and pn. To form a junction. When the emitter portion 212 has an n-type conductivity type, the emitter portion 212 may be doped with impurities of a pentavalent element such as phosphorus (P), arsenic (As), antimony (Sb), and the like on the substrate 211. Can be formed.

Accordingly, when electrons in the semiconductor receive energy by light incident on the substrate 211, the electrons move toward the n-type semiconductor and the holes move toward the p-type semiconductor. Therefore, when the substrate 211 is p-type and the emitter portion 212 is n-type, the separated holes move toward the substrate 211 and the separated electrons move toward the emitter portion 212.

On the contrary, the substrate 211 may be of an n-type conductivity type and may be made of a semiconductor material other than silicon. When the substrate 211 has an n-type conductivity type, the substrate 211 may contain impurities of pentavalent elements such as phosphorus (P), arsenic (As), and antimony (Sb).

Since the emitter portion 212 forms a p-n junction with the substrate 11, when the substrate 211 has an n-type conductivity type, the emitter portion 212 has a p-type conductivity type. In this case, the separated electrons move toward the substrate 211 and the separated holes move toward the emitter portion 212.

When the emitter portion 212 has a p-type conductivity type, the emitter portion 212 may dopant impurities of trivalent elements such as boron (B), gallium (Ga), and indium (In) onto the substrate 211. Can be formed.

An antireflection film 215 formed of at least one material selected from silicon nitride film SiNx, silicon oxide film SiO ₂ , and titanium dioxide TiO ₂ is formed on the emitter portion 212 of the substrate 211. The anti-reflection film 215 increases the efficiency of the solar cell 210 by reducing the reflectance of light incident on the solar cell 210 and increasing selectivity of a specific wavelength region. The anti-reflection film 215 may have a thickness of about 70 nm to 80 nm, and may be omitted as necessary.

The plurality of first electrodes 213 are formed on the emitter part 212 and electrically connected to the emitter part 212, and are formed in one direction while being spaced apart from the adjacent first electrode 213. Each first electrode 213 collects charge, for example, electrons moved toward the emitter unit 212 and transfers the electrons to the corresponding first current collector 214.

The plurality of first electrodes 213 are made of at least one conductive material, and the conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), and zinc (Zn). ), At least one selected from the group consisting of indium (In), titanium (Ti), gold (Au), and combinations thereof, but may be formed of another conductive metal material.

The plurality of first current collectors 214 are positioned on the emitter unit 212. The first current collector 214, also called a bus bar, is formed in a direction crossing the first electrode 213. Accordingly, the first electrode 213 and the first current collector 214 are disposed to intersect the emitter portion 212.

The first current collector 214 is made of at least one conductive material and is connected to the emitter part 212 and the first electrode 213. Accordingly, the first current collector 214 outputs the charge, for example, electrons transferred from the first electrode 213 to the external device.

The conductive metal materials constituting the first current collector 214 include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), and titanium. It may be at least one selected from the group consisting of (Ti), gold (Au), and combinations thereof, but may be made of another conductive metal material. In the present exemplary embodiment, the plurality of first current collectors 214 may include the same material as the first electrode 213, but may include a material different from that of the first electrode.

The first electrode 213 and the first current collector 214 are coated with a conductive metal material on the anti-reflection film 215 and then patterned, and then etched, for example, glass, included in the conductive metal material in the process of baking the same. As the anti-reflection film is etched by the glass frit, the antireflection film may be electrically connected to the emitter unit 212.

The second electrode 216 is formed on the opposite side of the light receiving surface of the substrate 211, that is, on the rear surface of the substrate 211, and collects charges, for example, holes, moving toward the substrate 211.

The second electrode 216 is made of at least one conductive material. The conductive material may be at least one selected from the group consisting of Ni, Cu, Ag, Al, Sn, Zn, In, Ti, Au, And combinations thereof, but may be made of other conductive materials.

The plurality of second current collectors 217 are positioned on the same surface as the second electrode 216. The second current collector 217 is formed in a direction crossing the first electrode 213, that is, in a direction parallel to the first current collector 214.

The second current collector 217 is made of at least one conductive material and is electrically connected to the second electrode 216. Accordingly, the second current collector 217 outputs the charge, for example, holes, transferred from the second electrode 216 to the external device.

The conductive metal materials constituting the second current collector 217 include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), and titanium. It may be at least one selected from the group consisting of (Ti), gold (Au), and combinations thereof, but may be made of another conductive metal material.

Hereinafter, the electrical connection structure of the solar cell panel will be described in detail.

The solar cell panel 200 includes a first area A1 in which a plurality of solar cells are located and a second area A2 located at an edge of the first area A1, and a plurality of in the first area A1. The solar cells 210 are arranged in the form of a plurality of strings.

Here, the string refers to a minimum series group electrically connected in a state where a plurality of solar cells are arranged in a line.

Therefore, the solar cell module 200 illustrated in FIGS. 1 and 3 has six strings, for example, the first to sixth strings S1 to S6.

Hereinafter, the strings S1 and S6 which are spaced apart from each other at regular intervals and positioned at edges of the solar cell panel 200 are referred to as first outer strings S1 and second outer strings S6, respectively. The strings S2 to S5 positioned between S1 and the second outer string S6 may be respectively classified into a first inner string S2, a second inner string S3, a third inner string S4, and a fourth inner string S4. It is called an internal string S5.

The plurality of solar cells 210 arranged in each of the strings S1 to S6 are electrically connected by the interconnector 220.

More specifically, the first current collector of any one of the plurality of solar cells 210 disposed adjacent to each other in the longitudinal direction in one string, for example, the first outer string S1 (see FIG. 5, 214). ) Is electrically connected to the second current collector (see FIG. 5, 217) of the adjacent solar cell by the interconnector 220a.

The interconnector 220a positioned at the lower side of the first outer string S1 is connected to the interconnector 220b positioned at the lower side of the first inner string S2 by another interconnector 222, and the second interconnector 220a is disposed at the lower side of the first outer string S1. The interconnector 220c positioned on the lower side of the inner string S3 is connected to the interconnector 220d positioned on the lower side of the third inner string S4 by the interconnector 222, and the fourth inner string S5. The interconnector 220e located at the lower side of the s) is connected to the interconnector 220f located at the lower side of the second outer string S6 by the interconnector 222.

Lead wires (LWs) are connected to the interconnectors 220a, 220b, 220c, 220d, 220c, and 220f positioned on the upper sides of the strings S1-S6.

In the following description, the lead wire connected to the interconnector 220a positioned on the upper side of the first outer string S1 is called the first lead wire LW1 and the interconnector 220f positioned on the upper side of the second outer string S6. The lead wire connected to is referred to as a second lead wire LW2.

The lead wires connected to the interconnectors 220b and 220c of the first inner string S2 and the second inner string S3 are referred to as a third lead wire LW3 and the third inner string S4 and the fourth inner string. The lead wires connected to the interconnectors 220d and 220e of S5 are referred to as fourth lead wires LW4.

According to a feature of the present invention, the first to fourth lead wires LW1 to LW4 are located in the second area A2 of the solar cell panel, and the interconnector connection part (ICP) and the terminal box connection part (JCP) Each contains a junction box connection part.

The first to fourth lead wires LW1 to LW4 do not overlap each other, and the interconnector connection portions ICP of the first to fourth lead wires LW1 to LW4 cross the plurality of strings S1 to S6. 3, 4, and in a transverse direction as shown in FIGS. 3 and 4.

Therefore, it is not necessary to use an insulating tube or an insulating film for insulating the lead wires LW1 to LW4 from the solar cells, thereby reducing the reliability deterioration due to damage of the insulating tube or the insulating film.

Meanwhile, the first lead wire LW1 and the second lead wire LW2 each have one terminal box connection part JCP, and the third lead wire LW3 and the fourth lead wire LW4 each have two terminal box connection parts JCP. It is provided. In addition, the terminal box connection portions JCP of the first to fourth lead wires LW1 to LW4 are arranged in a direction parallel to the plurality of strings S1 to S6, that is, in the longitudinal direction as shown in FIGS. 3 and 4.

Hereinafter, a connection structure between the lead wires LW1 to LW4 and the terminal box will be described.

Three terminal boxes JB1 to JB3 are positioned on the rear surface of the rear sheet as the second area A2 of the solar cell panel.

In this case, the first terminal box JB1 is positioned at a midpoint between the first outer string S1 and the first inner string S2, and the second terminal box JB2 is the fourth inner string S5 and the second outer string S. The third terminal box JB3 is positioned at an intermediate point of S6, and the third terminal box JB3 is located at an intermediate point of the second inner string S3 and the third inner string S4.

In addition, each of the first to third terminal boxes JB1 to JB3 includes one bypass diode BD.

Hereinafter, for convenience of description, a bypass diode provided in the first terminal box JB1 is referred to as a first bypass diode BD1, and a bypass diode provided in the second terminal box JB2 is referred to as a second bypass diode BD2. The bypass diode provided in the third terminal box JB3 is referred to as a third bypass diode BD3.

The interconnector connection unit ICP of the first lead wire LW1 connects two to three interconnectors 220a provided in the first external string S1 and connects the terminal box connection unit JCP connected to the interconnector connection unit ICP. ) Is connected to one terminal of the first bypass diode BD1 provided in the first terminal box JB1.

Similarly, the interconnector connection unit ICP of the second lead wire LW2 connects two to three interconnectors 220f provided in the second external string S6 and is connected to the interconnector connection unit ICP. The connection part JCP is connected to one terminal of the second bypass diode BD2 provided in the second terminal box JB2.

The interconnector connecting portion ICP of the third lead wire LW3 connects the interconnectors 220b and 220c provided in the first inner string S2 and the second inner string S3, and the interconnector connecting portion ICP. ), One of the two terminal box connections, for example, the terminal box connection located on the right side of FIG. 3 is connected to one terminal of the bypass diode BD3.

Similarly, the interconnector connecting portion ICP of the fourth lead wire LW4 connects the interconnectors 220d and 220e provided in the third inner string S4 and the fourth inner string S5, and the interconnector connecting portion One of the two terminal box connections connected to the (ICP), for example, the terminal box connection located on the right side of FIG. 4, is connected to the other terminal of the third bypass diode BD3, and the other, for example, the terminal box connection part located on the left side of FIG. 4. Is connected to the other terminal of the second bypass diode BD3.

Accordingly, a first current, for example, a positive current, is collected in the first terminal box BD1, and a second current, for example, a negative current, is collected in the second terminal box BD2.

In addition, a cable CB is connected to one terminal of the first bypass diode BD1 and one terminal of the second bypass diode BD2, and each cable CB is electrically connected to a cable of a neighboring solar cell module. Is connected.

According to this configuration, since the first terminal box BD1 and the second terminal box BD2 are positioned adjacent to the first external string S1 and the second external string S6, respectively, the first lead wire LW1 and the first terminal box BD2 are disposed. The length of the two lead wires LW2 can be effectively reduced.

In addition, since the length of the cable CB electrically connecting the first terminal box BD1 to the second terminal box BD2 of the neighboring solar cell module can be reduced, the solar cell due to the voltage drop generated in the lead wire and the cable. The module's output can be prevented from falling.

Since each terminal box is provided with only one bypass diode, each terminal box has a better heat dissipation effect than a case where the terminal box is provided with a plurality of bypass diodes, thereby ensuring reliability of the solar cell module.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

100: solar cell module 200: solar cell panel
210: solar cell 220: interconnect
230: protective film 240: transparent member
250: rear sheet 260: insulating film
300: frames JB1 to JB3: terminal box
BD1 to BD3: Bypass diodes LW1 to LW4: Lead wire

Claims

A solar cell panel including a first outer string and a second outer string spaced apart from each other by a predetermined distance, and at least two inner strings positioned between the first and second outer strings;
An interconnector for electrically connecting the plurality of solar cells in each string;
A first terminal box including a first bypass diode electrically connected to an interconnector of the first external string;
A second terminal box including a second bypass diode electrically connected to an interconnector of the second external string; And
A third terminal box including a third bypass diode electrically connected to an interconnector of the inner strings
Including,
And the first bypass diode and the second bypass diode are electrically connected to the third bypass diode, respectively.

In claim 1,
The solar cell panel includes a first region in which the plurality of strings are positioned and a second region located at an edge of the first region.

In claim 2,
The first terminal box to the third terminal box is located in the second region solar cell module.

4. The method of claim 3,
The interconnector of the first external string and the first bypass diode are electrically connected by a first lead wire, and the interconnector of the second bypass diode and the second external string is electrically connected by a second lead wire. And the first bypass diode and the third bypass diode are electrically connected by a third lead wire, and the third bypass diode and the second bypass diode are electrically connected by a fourth lead wire. Battery module.

5. The method of claim 4,
The first to fourth lead wires are located in the second region, and each of the solar cell modules includes an interconnector connection part and a terminal box connection part.

The method of claim 5,
The interconnector connecting portions of the first to fourth lead wires are arranged in a straight line in a direction crossing the plurality of strings.

The method of claim 6,
The first lead wire and the second lead wire each have one terminal box connection portion, and the third lead wire and the fourth lead wire each have two terminal box connection portions.

In claim 7,
The terminal box connection portions of the first to fourth lead wires are arranged in a direction parallel to the strings.