JP2023049726A - Solar battery module and photovoltaic power generation system - Google Patents

Abstract

To provide a solar battery module and a photovoltaic power generation system capable of enhancing a filling factor of cells to a module area without using a dummy cell in a corner module.SOLUTION: In a solar battery module M1, a plurality of solar battery cells C are respectively connected in series to configure a plurality of cell groups CG. The plurality of cell groups CG are respectively connected by intermediate electrode wirings La to configure a plurality of strings S. The plurality of strings S are connected in parallel with each other. The solar battery cell C is a division cell. The numbers of cells in columns of the cell groups CG are all different. A difference in the number of cells in the column between the adjacent cell groups CG is not constant.SELECTED DRAWING: Figure 1

Description

The present invention relates to a solar cell module and a solar power generation system using the same.

In recent years, solar cell modules using split cells have become mainstream (for example, Patent Document 1). A split cell here refers to a small cell obtained by splitting a standard size cell (a cell for one solar cell wafer, also referred to as a full cell), for example, a half cell obtained by splitting a full cell in half. In the half cell, the current value of the current per cell can be halved compared to the full cell, and the power loss of the solar cell module can be reduced accordingly.

Assuming that a solar cell module formed by connecting a plurality of full cells in series has a current of 10 A, in order to obtain a similar current in a solar cell module using half cells, two strings each having a plurality of half cells connected in series are connected in parallel. must be connected to That is, a current of 5A is generated in one string, so a current of 10A is obtained by connecting two strings in parallel.

A common usage pattern of solar cell modules is to arrange a plurality of modules on a roof or the like and connect them to each other to form a photovoltaic power generation system. Here, when installing a photovoltaic power generation system on a hipped roof or the like, a rectangular module and a polygonal (for example, pentagonal) corner module are combined (for example, Patent Document 2).

Japanese Unexamined Patent Application Publication No. 2020-98931 Patent No. 2017-112175

In a solar cell power generation system, when connecting rectangular modules and corner modules, it is necessary to match the output characteristics of each module. In a corner module where cells are arranged in a stepped pattern, if the number of cells is adjusted to match the output characteristics, and if the area where no cells are arranged is widened, the filling ratio of the cells relative to the module area will appear low, and this will spoil the appearance. .

Patent Literature 2 discloses a corner module in which a dummy cell is arranged in an empty space (an area in which no cell is arranged) of the corner module to suppress deterioration of aesthetic appearance. However, provision of dummy cells that do not contribute to power generation is disadvantageous in terms of cost.

The present invention has been made in view of the above problems, and aims to provide a solar cell module and a solar power generation system capable of increasing the cell filling rate with respect to the module area without using dummy cells in the corner modules. aim.

In order to solve the above problems, a solar cell module according to a first aspect of the present invention includes a plurality of solar cells connected in series to form a plurality of cell groups, and the plurality of cell groups each A plurality of strings are connected by intermediate electrode wirings, the plurality of strings are connected in parallel, the solar cells are divided cells, and the number of cells in each column of the cell group is all different and adjacent to each other. It is characterized in that the difference in the number of cells in the columns of the cell group is not constant.

According to the above configuration, in the corner module, the cell filling rate with respect to the module area can be increased, and the appearance of the solar cell module can be improved.

Further, in the above solar cell module, the difference in the number of cells between the adjacent cell rows may be within one full cell.

According to the above configuration, it is possible to prevent the generation of a large space exceeding one full cell in the area where no cell is installed, and it is possible to further improve the appearance of the solar cell module.

Further, in the above solar cell module, the difference in the number of cells between the adjacent cell rows can be smaller than that of one full cell.

According to the above configuration, the areas in each row of the cell group where no cells are installed can be brought closer to a uniform space, and the appearance of the solar cell module can be further improved.

Further, in order to solve the above problems, a solar cell module according to a second aspect of the present invention has a plurality of cell rows formed in a stepped shape, and a plurality of solar cells each arranged in series. a plurality of cell groups are configured by connecting the plurality of cell groups by intermediate electrode wirings to configure a plurality of strings, the plurality of strings are connected in parallel, and the solar cells are divided cells In at least one of the cell strings, the string is switched in the middle, and in the cell string in which the string is switched, the end connected to the end of the string in the middle of the cell string It is characterized in that the electrode wiring is arranged.

Further, the solar cell module may be configured such that each string has the same number of cells.

According to the above configuration, the voltage in each string can be the same, the occurrence of reverse current between different strings can be avoided, and power loss can be effectively prevented.

Further, in order to solve the above problems, a solar power generation system according to a third aspect of the present invention is a solar power generation system comprising a combination of corner modules and rectangular modules, wherein the corner modules are the above-described is characterized by being a solar cell module of

Further, in the photovoltaic power generation system, the corner module and the rectangular module can be configured to use the same type of divided cells.

According to the above configuration, by using the same type of divided cells for the corner modules and the rectangular modules, the appearance of the entire photovoltaic power generation system can be improved.

ADVANTAGE OF THE INVENTION The solar cell module and solar power generation system of this invention can raise the filling rate of the cell with respect to a module area in a corner module, and it is effective in improving an aesthetic appearance.

1 is a plan view schematically showing an example of a solar cell module according to Embodiment 1; FIG. FIG. 4 is a plan view schematically showing a modification of the solar cell module of Embodiment 1; FIG. 4 is a plan view schematically showing an example of a solar cell module according to Embodiment 2; FIG. 11 is a plan view showing an example of arrangement of corner modules and rectangular modules in a photovoltaic power generation system according to Embodiment 3;

[Embodiment 1]
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same parts are given the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

FIG. 1 is a plan view schematically showing an example of a solar cell module M1 according to this embodiment. The solar cell module M1 is a polygonal (pentagonal in this example) corner module having right-angled corners and non-right-angled corners, and is composed of a plurality of cell rows formed in steps. It is Note that the solar cell module M1 shown in FIG. 1 may be configured so that the polarities are reversed.

The solar cell module M1 comprises two strings connected in parallel, namely a first string S(1) and a second string S(2). The first string S(1) includes a plurality of cell groups CG(1,1) to CG(1,n1) (n1 is an integer of 2 or more). The second string S(2) includes a plurality of cell groups CG(2,1) to CG(2,n2) (n2 is an integer equal to or greater than 2). In the solar cell module M1 shown in FIG. 1, n1=2 and n2=4. In the configuration of FIG. 1, each cell group CG constitutes a different cell string, and the cell group CG and the cell string are in one-to-one correspondence.

Each cell group in the first string S(1) and the second string S(2) is connected by an intermediate electrode wiring La (bus bar). In each of the first string S(1) and the second string S(2), the solar cells C are connected in series. The intermediate electrode wiring La is an electrode wiring that connects the ends of the cell groups CG included in the same string.

More specifically, the solar cells C are arranged in a row in a predetermined row direction X in the first string S(1) and the second string S(2). The first string S(1) and the second string S(2) are arranged side by side in the orthogonal direction Y. As shown in FIG. In each of the first string S(1) and the second string S(2), cell groups CG(1,1) to CG(1,n1) and CG(2,1) to CG(2,n2) are They are arranged side by side in the orthogonal direction Y. The end electrode wiring Lb (bus bar) connected to at least one side of the cell groups CG(1,1) to CG(1,n1) and CG(2,1) to CG(2,n2) is arranged in the row direction. It is provided at the end on at least one side of X. In the example shown in FIG. 1, the end electrode wiring lines Lb connected to both sides of the cell groups CG(1,1) to CG(1,n1) and CG(2,1) to CG(2,n2) are arranged in the row direction. It is provided at the end of one side (X1) of X. The end electrode wiring Lb is an electrode wiring connected to the end of each string.

In the example shown in FIG. 1, the end electrode wiring Lb of the cell group CG (1, 1) and the end electrode wiring Lb of the cell group CG (2, n2) are connected to the cathode (not shown). Connected. The end electrode wiring Lb of the cell group CG(1,n1) and the cell group CG(2,1) is connected to the anode connection electrode wiring (not shown). As a result, the first string S(1) and the second string S(2) in the solar cell module M1 are connected in parallel.

In this embodiment, the solar cell C in the solar cell module M1 is exemplified by dividing a solar cell (full cell) substrate having a size of about 160 mm square into two. That is, the photovoltaic cell C after division is a half cell having a size of about 160 mm×80 mm square as a whole. In addition, the specific configuration of each solar cell C, and the solar cells C in the cell groups CG (1, 1) to CG (1, n1) and CG (2, 1) to CG (2, n2) Since the connection configuration is well known, detailed description is omitted here.

In the solar cell module M1, the number of solar cells C in one first string S(1) is equal to the number of solar cells C in the other second string S(2). In the example shown in FIG. 1, each of the first string S(1) and the second string S(2) has 22 cells. In this way, by equalizing the number of solar cells C in the first string S(1) and the second string S(2), one string S(1) and the other string S(2) can have the same voltage. As a result, the occurrence of backflow between the string S(1) and the string S(2) can be avoided, and power loss can be effectively prevented.

In addition, the solar cell module M1 has six cell rows, but the number of cells is different in each cell row, and the number of cells changes stepwise along the orthogonal direction Y monotonically. arranged in a shape. Specifically, the cell group CG(1,1) has 12 cells, the cell group CG(1,n1) has 10 cells, the cell group CG(2,1) has 8 cells, and the cell group CG(2,1) has 8 cells. 2) has 6 sheets, cell group CG(2,3) has 5 sheets, and cell group CG(2,n2) has 3 sheets. In the first embodiment, since the cell group CG and the cell row correspond one-to-one in the solar cell module M1, the number of cells in each cell group CG is also used to mean the number of cells in each cell row. ing.

Moreover, in the solar cell module M1, the difference in the number of cells between adjacent cell rows is not constant. Specifically, the difference in the number of cells between the cell group CG(2,2) and the cell group CG(2,3) is 1, but the difference in the number of cells between adjacent cell rows is 2. is.

In the corner module in which the solar cells C are arranged in a stepped pattern, it is required to effectively cover the polygonal module surface with the cells to suppress deterioration of the aesthetic appearance. Furthermore, when a plurality of strings are connected in parallel in a corner module, it is necessary to align the voltages in each string (that is, align the number of cells in each string). By changing the difference in the number of cells between adjacent cell rows instead of making it constant, the cells can be efficiently laid out according to the shape of the polygonal module surface.

In the solar cell module M1 according to Embodiment 1, the difference in the number of cells between adjacent cell rows is not constant, and the number of cells is different in all the cell rows (there are no cell rows with the same number of cells). By arranging in such a manner, the filling rate of the cells with respect to the module area can be increased, and the appearance can be improved. In addition, since the number of cells is different in all cell rows, the distance between the oblique side of the polygonal module and the cell C at the end of the cell row can be made small, and the cell filling rate with respect to the module area increases, and the output of the module increases. can increase

As a more preferable condition, in the solar cell module M1, the difference in the number of cells between adjacent cell rows is at most one full cell (two half cells) or less. Also, the difference in the number of cells between adjacent cell rows is made smaller than one full cell. In the example of FIG. 1, the difference in the number of cells in adjacent columns is two half-cells at a large number and one half-cell at a small number (between cell group CG(2,2) and cell group CG(2,3)). Since the number of cells is one, the difference in the number of cells is one half cell. Further, the locations where the difference in the number of cells is different are not on the end side but on the inner side in the direction in which the cell rows are arranged (the orthogonal direction Y). In the example of FIG. 1, the location where the difference in the number of cells in adjacent columns is different is between the cell group CG(2,2) and the cell group CG(2,3). As a result, even if the difference in the number of cells between adjacent cell rows is not constant, the difference in the number of cells becomes less noticeable, and the filling rate of the cells with respect to the module area can be increased, thereby improving the appearance. .

In addition, in the solar cell module M1, the number of cells in the cell row having the smallest number of cells is preferably larger than the maximum difference between the numbers of cells in adjacent cell rows. In the example of FIG. 1, the cell row with the smallest number of cells is the cell group CG (2, n2), which has three cells. On the other hand, the maximum difference in the number of cells between adjacent cell columns is two. With such a cell arrangement, the solar cell module M1 appears to have a high cell filling rate.

FIG. 2 is a plan view schematically showing a modification of solar cell module M1 according to the present embodiment. In the example of FIG. 2, the solar cells C are arranged such that the polarity of the second string S(2) is reversed with respect to the example of FIG. In the example shown in FIG. 2, the end electrode wiring Lb of the cell group CG(1,1) and the end electrode wiring Lb of the cell group CG(2,1) are cathode connection electrode wirings (not shown). ). The end electrode wiring Lb of the cell group CG(1, n1) and the end electrode wiring Lb of the cell group CG(2, n2) are connected to the anode connection electrode wiring (not shown). Note that the solar cells C may be arranged such that the polarity of the first string S(1) is reversed with respect to the example of FIG.

[Embodiment 2]
In Embodiment 1, the solar cell module M1 using half cells as the solar cells C is exemplified. However, the present invention is not limited to this, and other split cells can be used as the solar cells C. FIG. In Embodiment 2, a solar cell module M2 using ⅓ cells as the solar cells C is illustrated. FIG. 3 is a plan view schematically showing an example of a solar cell module M2 according to this embodiment.

The solar cell module M2 comprises three strings connected in parallel, namely a first string S(1), a second string S(2) and a third string S(3). The first string S(1) includes a plurality of cell groups CG(1,1) to CG(1,n1) (n1 is an integer of 2 or more). The second string S(2) includes a plurality of cell groups CG(2,1) to CG(2,n2) (n2 is an integer equal to or greater than 2). The third string S(3) includes a plurality of cell groups CG(3,1) to CG(3,n3) (n3 is an integer of 2 or more). In the solar cell module M2 shown in FIG. 1, n1=2, n2=2, and n3=3.

Cell groups CG (1, 1) to CG (1, n1), CG (2, 1) to CG (2, n2), and CG (3, 1) to CG (3, n3) each have an intermediate electrode wiring La (busbar). In these cell groups, the solar cells C are connected in series.

In the example shown in FIG. 3, the end electrode wiring Lb of the cell group CG (1, n1), the end electrode wiring Lb of the cell group CG (2, n2), and the end electrode wiring of the cell group CG (3, n3) Lb is connected to a cathode connection electrode wiring (not shown). The end electrode wirings Lb of the cell group CG(1,1), the cell group CG(2,1) and the cell group CG(3,1) are connected to the anode connection electrode wiring (not shown). As a result, the first string S(1), the second string S(2) and the third string S(3) in the solar cell module M2 are connected in parallel. In the example shown in FIG. 3, each of the first string S(1), the second string S(2) and the third string S(3) has 24 cells. 3, the solar cells C are arranged such that the polarities are reversed in any one of the first string S(1), the second string S(2) and the third string S(3). may be

In this way, when a split cell obtained by dividing a full cell into 1/m (m is a natural number of 2 or more) is used as the solar cell C, in a solar cell module in which m strings are connected in parallel, the full cells are connected in series. It is possible to obtain the same current as a solar cell module formed by

In the corner module, since the solar cells C are arranged stepwise, it is not easy to match the number of cells in each string in a configuration in which one cell group corresponds to one cell row. This is even more so when trying to increase the cell filling factor in the module. On the other hand, the solar cell module M2 of FIG. 3 adopts a configuration in which a plurality of cell groups are allowed to be included in one cell row, and strings are switched in the middle of the cell row. Specifically, in the second cell row from the right in FIG. 3, the cell group CG (1, n1) belonging to the first string S(1) and the cell group CG (2 , 1) and a switch is made from the first string S(1) to the second string S(2). In the example of FIG. 3, the number of cell columns whose strings are switched midway is only one, but there may be two or more cell columns whose strings are switched midway.

Further, when strings are switched in the middle of a cell row, the end electrode wiring Lb is arranged using an area of one cell in the middle of the cell row at the string switching point in the cell row. This facilitates matching the number of cells in each string. In addition, in a cell row in which the string is switched in the middle and the end electrode wiring Lb is arranged in the middle, the arrangement area of the end electrode wiring Lb is also counted as the apparent number of cells. That is, in the second cell row from the right in FIG. 3, the number of actually arranged solar cells C is 15, but the number of cells in this cell row is counted as 16.

[Embodiment 3]
In the third embodiment, an example of a photovoltaic power generation system configured by combining corner modules and rectangular modules will be described.

FIG. 4 is a plan view showing an arrangement example of a solar cell module M1 that is a corner module and a solar cell module M3 that is a rectangular module in a photovoltaic power generation system. The number of corner modules and rectangular modules used in the photovoltaic power generation system according to the third embodiment and the layout layout thereof are not particularly limited. However, each module used in the photovoltaic power generation system is connected in series with each other, and the system current in each module needs to be the same current (for example, 10 A).

The solar cell module M3 shown in FIG. 4 uses half cells as the solar cells C, and uses two strings, each of which is formed by connecting a plurality of half cells in series, connected in parallel. A detailed description of the layout of the strings and electrode wiring in the solar cell module M3 will be omitted.

In a photovoltaic power generation system, when half cells are used in rectangular modules, it is preferable to use half cells in corner modules as well, because the appearance of the photovoltaic power generation system can be improved. In this regard, it is preferable to use the same type of solar cells for the rectangular module and the corner module, without being limited to half cells. For example, the rectangular module and the corner module may both use ⅓ solar cells.

However, the present invention is not limited to this, and the rectangular module and the corner module may use different solar cells. For example, the corner modules may use half cells and the rectangular modules may use full cells. Even in this case, the corner module and the rectangular module must have the same current flow, so the corner module must have two half cells in parallel, and the rectangular module must have one full cell in series.

The embodiments disclosed this time are exemplifications in all respects and are not grounds for restrictive interpretation. Therefore, the technical scope of the present invention is not to be interpreted only by the above-described embodiments, but is defined based on the claims. In addition, all changes within the meaning and range of equivalence to the claims are included.

C Solar battery cell CG Cell group La Intermediate electrode wiring Lb End electrode wiring M1 to M3 Solar battery module S String

Claims (7)

It has a plurality of cell rows formed stepwise, and a plurality of solar cells are connected in series to form a plurality of cell groups, and the plurality of cell groups are connected by intermediate electrode wirings. a plurality of strings are configured by connecting the plurality of strings in parallel;
The solar cell is a split cell,
the numbers of cells in the cell columns are all different,
A solar cell module, wherein a difference in the number of cells between adjacent cell rows is not constant. The solar cell module according to claim 1,
A solar cell module, wherein the difference in the number of cells between the adjacent cell rows is within one full cell. The solar cell module according to claim 1 or 2,
A solar cell module, wherein a difference in the number of cells between adjacent cell rows is smaller than that of one full cell. It has a plurality of cell rows formed stepwise, and a plurality of solar cells are connected in series to form a plurality of cell groups, and the plurality of cell groups are connected by intermediate electrode wirings. a plurality of strings are configured by connecting the plurality of strings in parallel;
The solar cell is a split cell,
A string is switched in the middle of at least one of the cell rows, and in the cell row in which the string is switched, an end electrode wiring is connected to an end of the string in the middle of the cell row. A solar cell module, characterized in that is arranged. The solar cell module according to any one of claims 1 to 4,
A solar cell module, wherein the number of cells in each string is the same. A photovoltaic power generation system comprising a combination of corner modules and rectangular modules,
A photovoltaic power generation system, wherein the corner module is the photovoltaic module according to any one of claims 1 to 5. The solar power generation system according to claim 6,
The solar power generation system, wherein the corner module and the rectangular module use the same type of divided cells.

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