WO2017164151A1

WO2017164151A1 - Terminal box

Info

Publication number: WO2017164151A1
Application number: PCT/JP2017/011127
Authority: WO
Inventors: 康敏森; 裕幸神納; 康博日高; 柴田　哲司; 優小宮山; 信之森田
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2016-03-25
Filing date: 2017-03-21
Publication date: 2017-09-28
Also published as: JP2019092234A

Abstract

This terminal box (1) for a solar battery module is provided with a casing (30), a plurality of terminal plates (10) disposed inside the casing (30), and bypass diodes (20) disposed between adjacent terminal plates (10). Each of the terminal plates (10) has a diode connection part (11) connected to a lead terminal (21) of the bypass diode (20), and a pair of a first terminal part (12a) and a second terminal part (12b) that respectively extend from both ends of the diode connecting part (11) in a first direction.

Description

Terminal box

The present invention relates to a terminal box for a solar cell module.

The solar cell module is provided with a plurality of strings in which solar cells are connected in series. In the solar cell module, a terminal box is provided to connect an output lead wire for outputting generated power from each string and an external connection cable.

Patent Document 1 discloses a configuration of a terminal box including a plurality of terminal plates for relaying output lead wires and external connection cables, and an axial lead type diode bridged between the terminal plates. ing. More specifically, a part of the terminal board is cut and raised in an L shape, and the sandwiching piece rises from the tip of the standing piece. As a result, smooth solderability between the diode and the terminal plate can be realized by fitting the lead leg of the diode into the holding piece and soldering the lead leg along the flat surface of the standing piece.

JP 2013-229424 A

However, in the conventional terminal box disclosed in Patent Document 1, in order to ensure solderability between the diode lead legs and the standing pieces, heat dissipation from the standing pieces cut and raised in an L shape is limited. is doing. For this reason, when current flows through the diode, heat stays in the diode and the vertical piece, so that there is a problem that sufficient heat dissipation of the terminal box cannot be secured while suppressing the amount of material used. Yes.

The present invention has been made to solve such a problem, and an object thereof is to provide a terminal box having improved heat dissipation while suppressing the amount of material used.

In order to achieve the above object, one aspect of a terminal box according to the present invention is a terminal box for a solar cell module, and includes a casing, a plurality of terminal plates disposed inside the casing, and a terminal box. A bypass diode disposed between the matching terminal plates, and each of the plurality of terminal plates is a diode connection portion connected to a lead terminal of the bypass diode, and both ends of the diode connection portion, A pair of first terminal portions and second terminal portions extending from each of both end portions in a first direction intersecting with an arrangement direction of the plurality of terminal plates.

According to the present invention, it is possible to realize a terminal box with improved heat dissipation while suppressing the amount of material used.

FIG. 1 is a perspective view schematically showing a terminal box provided in a solar cell module according to an embodiment. FIG. 2 is a front view illustrating a state in which the lid of the terminal box according to the embodiment is removed. FIG. 3 is a perspective view illustrating a state in which the lid of the terminal box according to the embodiment is removed. FIG. 4 is an exploded perspective view of the terminal box according to the embodiment. FIG. 5 is a diagram illustrating a state in which the terminal box cover according to the embodiment is attached. FIG. 6 is a perspective view of the terminal board according to the embodiment. FIG. 7 is a front view and a side view of the terminal board according to the embodiment. FIG. 8 is a cross-sectional view of the terminal board according to the embodiment taken along line VIII-VIII in FIG. FIG. 9 is a perspective view of a terminal board used in a conventional terminal box. FIG. 10 is a perspective view of a terminal board according to Modification 1 of the embodiment. FIG. 11 is a perspective view of a terminal board according to Modification 2 of the embodiment. FIG. 12 is a perspective view of a terminal board according to Modification 3 of the embodiment. FIG. 13A is a front view illustrating a state in which a cover of a terminal box according to Modification 4 of the embodiment is removed. FIG. 13B is a front view showing a state in which a terminal box cover according to Modification 5 of the embodiment is removed. FIG. 13C is a front view illustrating a state in which a terminal box cover according to Modification 6 of the embodiment is removed. FIG. 14 is a diagram comparing temperature distributions of the terminal boxes according to the example and the comparative example. FIG. 15 is a graph showing the temperature distribution of the bypass diode according to the example and the comparative example. FIG. 16A is a diagram for explaining the dimensions of the terminal plate when the surface area ratio of the first terminal portion and the second terminal portion is changed. FIG. 16B is a graph showing the heat dissipation characteristics of the terminal board when the surface area ratio of the terminal board according to the embodiment is changed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Therefore, numerical values, shapes, materials, components, arrangement positions of components, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily shown strictly. Moreover, in each figure, the same code | symbol is attached | subjected to the substantially same structure, The overlapping description is abbreviate | omitted or simplified.

In the present specification and drawings, the X axis, the Y axis, and the Z axis represent the three axes of the three-dimensional orthogonal coordinate system. The X axis and the Y axis are orthogonal to each other, and are both orthogonal to the Z axis.

(Embodiment)
[1. Terminal box configuration]
First, the terminal box 1 according to the embodiment will be described.

FIG. 1 is a perspective view schematically showing a terminal box 1 provided in a solar cell module 100 according to an embodiment.

A plurality of solar cell modules 100 are installed on the roof of a facility such as a house to constitute a solar power generation system. As shown in FIG. 1, a terminal box 1 is provided in each of the plurality of solar cell modules 100. For example, when a storage battery is installed in a facility, the terminal box 1 is an intermediate member disposed in a power path between the solar cell module 100 and the storage battery. In addition, the terminal box 1 is being fixed to the back surface of the solar cell module 100, for example with the adhesive material or the adhesive tape.

Although not shown, each solar cell module 100 is provided with a plurality of solar cells arranged in a matrix on the same surface. A plurality of solar cells arranged in the row direction are connected in series to form a string. Each solar cell module 100 is provided with a plurality of strings.

The plurality of solar cell modules 100 are electrically connected to each other in series or in parallel via the terminal box 1. That is, the terminal box 1 electrically connects two adjacent solar cell modules 100 to other solar cell modules 100.

As shown in FIG. 1, the terminal box 1 electrically connects the output lead wire 2 and the external connection cable 3. That is, the output lead 2 and the external connection cable 3 are connected via the terminal box 1.

The output lead wire 2 is an electrode wire drawn from each string in order to output the electric power generated by the solar battery cell of the solar battery module 100. For example, five output lead wires are provided.

The external connection cable 3 is a cable for outputting the power generated by the solar cell module 100 from the terminal box 1 to the outside. The external connection cable 3 is a connection cable for connecting two adjacent solar cell modules 100 via the terminal box 1. Specifically, two external connection cables 3 are connected to the terminal box 1, and each external connection cable 3 has one end connected to the terminal box 1 and the other end adjacent to the solar cell module. 100 terminal boxes 1 are electrically connected.

Next, a detailed configuration of the terminal box 1 according to the embodiment will be described with reference to FIGS. 2 to 4 are views showing the inside of the terminal box 1 according to the embodiment and showing a state in which the lid 32 is removed. FIG. 5 is a view showing a state where the lid 32 of the terminal box 1 is attached. 2 to 4 are a front view, a perspective view, and an exploded perspective view of the terminal box 1, respectively.

The terminal box 1 is a terminal box for a solar cell module, and as shown in FIGS. 2 to 4, a plurality of terminal plates 10, one or more bypass diodes 20, a plurality of terminal plates 10 and a bypass diode 20 are provided. And a housing 30 for housing the container.

As shown in FIGS. 2 and 3, the plurality of terminal boards 10 are arranged inside the housing 30. The plurality of terminal boards 10 are arranged adjacent to each other so that their longitudinal (Y-axis direction) axes are substantially parallel to each other.

As shown in FIGS. 2 and 4, each of the plurality of terminal plates 10 extends from each of the diode connection portion 11 connected to the lead terminal 21 connected to the bypass diode 20 and both ends of the diode connection portion 11. A pair of first terminal portion 12a and second terminal portion 12b.

The number of terminal boards 10 corresponding to the number of strings of solar cell modules 100 is arranged, and five terminal boards 10 are arranged in the present embodiment. As shown in FIG. 2, the output lead wires 2 drawn from the strings of the solar cell modules 100 are connected to the first terminal portions 12 a of the five terminal plates 10. When one or more solar cells have a high resistance and become a reverse bias state due to light shielding or contamination due to the above connection, the rated current is supplied to the bypass diode 20 connected to the string including the one or more solar cells. Flows. That is, the bypass diode 20 can bypass the string including the one or more solar cells and output power generated by another string without generating a so-called hot spot in the string. .

The five terminal boards 10 include output terminal boards that are electrically connected to the external connection cables 3. In the present embodiment, the terminal boards 10 located at both ends of the five terminal boards 10 are output terminal boards. As shown in FIG. 2, the terminal plate 10 which is an output terminal plate is a terminal plate for relaying the output lead wire 2 and the external connection cable 3. The terminal plate 10 includes the output lead wire 2. Are connected to the external connection cable 3. Specifically, in the terminal plate 10 that is an output terminal plate, the output lead wire 2 is electrically and mechanically connected to the first terminal portion 12a, and the external connection cable 3 is electrically connected to the second terminal portion 12b. And mechanically connected.

The first terminal portion 12a of the terminal plate 10 that is an output terminal plate and the output lead wire 2 are connected at the first terminal portion 12a of the terminal plate 10. As shown in FIG. 2, one end of the output lead 2 is introduced from the outside of the housing 30 through an opening 31 a provided at the bottom of the housing 30 (box body 31). The exposed core wire (conductive wire) at one end of the output lead wire 2 introduced into the housing 30 is bent toward the surface of the first terminal portion 12a so that the portion protruding from the opening portion 31a is formed. It is connected to the first terminal portion 12a by solder. In FIG. 2, the output lead wire 2 connected to each terminal plate 10 and the region (solder region) where the output lead wire 2 is soldered to the terminal plate 10 (first terminal portion 12a) are indicated by broken lines. Yes.

The second terminal portion 12b of the terminal plate 10 that is an output terminal plate and the external connection cable 3 are connected by a crimp joint portion 17 formed on the second terminal portion 12b of the terminal plate 10. As shown in FIG. 2, one end of the external connection cable 3 extends from the outside of the housing 30 (box 31) to the inside through a through hole 31 b provided in a side portion of the housing 30 (box 31). Has been introduced. An exposed core wire (conductive wire) at one end of the external connection cable 3 introduced into the housing 30 is crimped and bonded at a crimping bonding portion 17 formed on the second terminal portion 12b of the terminal plate 10 which is an output terminal plate. As a result, the terminal board 10 is fixed. In FIG. 2, the core wire of the external connection cable 3 connected to each terminal board 10 is indicated by a broken line.

Of the five terminal boards 10, other than the output terminal board are non-output terminal boards. In the present embodiment, the terminal plates 10 arranged between the terminal plates 10 (output terminal plates) located at both ends are non-output terminal plates. The non-output terminal plate is a terminal plate 10 to which the external connection cable 3 is not connected, and only the output lead wire 2 of the output lead wire 2 and the external connection cable 3 is connected.

In addition, the connection method of the 1st terminal part 12a of the terminal board 10 which is a non-output terminal board, and the output lead wire 2 is the same as that of the terminal board 10 which is an output terminal board. Specifically, the first terminal portion 12a of the terminal board 10 which is a non-output terminal board and the output lead wire 2 are connected by solder.

The bypass diode 20 is a backflow prevention diode and is disposed between adjacent terminal plates 10. As shown in FIGS. 2 to 4, in the present embodiment, the bypass diode 20 is disposed between the terminal boards 10. Specifically, four bypass diodes 20 are arranged. In the present embodiment, the four bypass diodes 20 are connected in a straight line via the diode connection portion 11 so as to be connected in series by the lead terminal 21. Each bypass diode 20 is arranged in a state of being bridged between the terminal boards 10 by the lead terminals 21. Each bypass diode 20 is sandwiched between a pair of claw pieces provided at the bottom of the box 31.

2 and 3, the lead terminal 21 connected to the bypass diode 20 is electrically and mechanically connected to the diode connection portion 11 of the terminal plate 10. The lead terminal 21 is connected to the diode connection portion 11 by solder. In FIG. 2, a region (solder region) in which the lead terminal 21 is solder-connected to the diode connecting portion 11 is indicated by a broken line.

The casing 30 constitutes the outline of the terminal box 1, and as shown in FIGS. 2 to 5, a box-shaped box 31 having one surface opened and a closed surface of the box 31 closed. And a lid 32 (see FIG. 5) fitted in the box 31. The lid 32 is fixed to the box 31 after the inside of the box 31 is sealed with a sealing member such as a potting material. The box body 31 and the lid 32 are formed of, for example, a resin having flame resistance and weather resistance.

As described above, the opening 31 a is formed at the bottom of the box 31, and the through hole 31 b is formed at the side of the box 31.

Further, as shown in FIGS. 2 and 4, a pair of protruding pieces 31 c and a pair of protruding pieces 31 d are formed on the bottom of the box 31 so as to protrude from the bottom toward the open surface. The pair of protrusion pieces 31c are formed so as to face each other along the Y-axis direction, and the pair of protrusion pieces 31d are formed so as to face each other along the X-axis direction. As shown in FIG. 2, a pair of insertion holes 15 provided in each terminal plate 10 are inserted into the pair of protrusion pieces 31c, and a pair of protrusion pieces 31d are provided in the pair of protrusion pieces 31c. The insertion hole 16 is inserted. Thereby, each terminal board 10 is arrange | positioned in the predetermined position of the box 31, and the position of a horizontal direction (XY plane direction) is controlled.

[2. Terminal board configuration]
Next, a detailed configuration of the terminal board 10 according to the embodiment will be described with reference to FIGS. 6 to 8 with reference to FIGS. FIG. 6 is a perspective view of the terminal board 10 according to the embodiment. FIG. 7A is a front view of the terminal board 10, and FIG. 7B is a side view of the terminal board 10. FIG. 8 is a cross-sectional view of the terminal board 10 taken along the line VIII-VIII in FIG. The terminal board 10 shown in FIGS. 6 to 8 is a non-output terminal board, but the output terminal board is also used for non-output except that the crimp joint 17 of the second terminal part 12b is formed. The configuration is the same as that of the terminal board.

As shown in FIGS. 6 and 7, the terminal plate 10 is a terminal plate used in the terminal box 1 for a solar cell module, and as described above, the diode connection portion 11 and the pair of first terminal portions 12 a and And a second terminal portion 12b.

The diode connection part 11 is a diode terminal part (terminal base) which is a part connected to the lead terminal 21 connected to the bypass diode 20, and is positioned between the first terminal part 12a and the second terminal part 12b. is doing.

Each of the pair of first terminal portion 12a and second terminal portion 12b extends from both ends of the diode connecting portion 11 in the Y-axis direction. Here, the Y-axis direction is defined as a first direction that intersects with the arrangement direction (X-axis direction) of the plurality of terminal boards 10. Specifically, the first terminal portion 12a extends from one end portion of the diode connection portion 11 in the Y-axis direction, and the second terminal portion 12b extends from the other end portion of the diode connection portion 11 in the Y-axis direction. It is extended from. Thus, the diode connection part 11 has a bridge structure connected to both the pair of first terminal parts 12a and second terminal parts 12b.

In the present embodiment, the surface area A1 of the first terminal portion 12a and the surface area A2 of the second terminal portion 12b are substantially equal. The ratio of the surface areas of the first terminal portion 12a and the second terminal portion 12b will be described in detail in examples described later.

In addition, each of the first terminal portion 12a and the second terminal portion 12b has a ceiling of the housing 30 at a position facing the terminal plate 10 adjacent in the second direction (X-axis direction) that is the arrangement direction of the terminal plates 10. It has the folding | returning part 14 extended in a surface direction or a bottom face direction (Z-axis direction). That is, the folded portion 14 is connected to each of the first terminal portion 12a and the second terminal portion 12b. The folded portion 14 is formed so as to be bent from both ends in the second direction of each of the first terminal portion 12a and the second terminal portion 12b. The folded portion 14 functions as a heat radiating fin. That is, since the volume and surface area of the terminal board 10 can be increased by forming the folded portion 14, the heat dissipation of the terminal board 10 can be improved. Moreover, since it can suppress that the terminal board 10 becomes large in a horizontal direction by bending and forming a radiation fin (folding part 14), the terminal board 10 can be reduced in size. Therefore, the terminal box 1 can also be reduced in size.

In the present embodiment, as shown in FIG. 4, the height Hc of the folded portion 14 included in one terminal plate 10 is the terminal plate 10 disposed outside the one terminal plate 10 in the housing 30. It becomes more than the height Ht of the folding | turning part 14 which has. In other words, the height Hc of the folded portion 14 of the terminal plate 10 disposed on the center side in the X-axis direction inside the housing 30 is the terminal plate 10 disposed on the end side in the X-axis direction inside the housing 30. Is the height Ht or more of the folded portion 14.

In the present embodiment, as shown in FIG. 7B, the diode connecting portion 11 has a substantially U-shaped side surface and cross-sectional shape, and the first terminal portion 12a and the second terminal portion 12b. It is formed so as to be stepped. That is, the surface of the diode connection portion 11 and the surfaces of the first terminal portion 12a and the second terminal portion 12b are located on different surfaces.

Specifically, as shown in FIGS. 2 to 4, the first terminal portion 12a and the second terminal portion 12b are in contact with the inner surface of the bottom portion of the housing 30 (box body 31). The contact surfaces of the first terminal portion 12 a and the second terminal portion 12 b that are in contact with the housing 30 are different from the connection surfaces that are connected to the lead terminals 21.

In addition, as shown in FIG. 2, the second direction (X-axis) is a direction orthogonal to the first direction (Y-axis direction) that is the arrangement direction of the diode connection part 11, the first terminal part 12a, and the second terminal part 12b. The minimum width in the direction) is larger than the maximum width in the second direction (X-axis direction) in the diode connection portion 11. In the present embodiment, the shapes of the diode connecting portion 11, the first terminal portion 12a, and the second terminal portion 12b are substantially rectangular in a plan view when viewed from the Z-axis direction.

In the present embodiment, the terminal plate 10 is made of, for example, aluminum. However, the material of the terminal plate 10 is not limited to this, and may be any material having high thermal conductivity, for example, oxygen-free copper, tough pitch, etc. Pure copper such as copper, phosphor bronze, brass and the like, and copper alloys thereof may be used.

Further, as shown in FIG. 8, at least one material of nickel (Ni), tin (Sn), copper (Cu), silver (Ag), and gold (Au) is formed on the surface of the diode connection portion 11. The plating layer 13 comprised by these may be formed. The plating layer 13 is formed on at least one of the front surface and the back surface of the diode connection portion 11. In the present embodiment, the first plating layer 13a made of nickel plating and the second plating layer 13b made of tin plating are formed on the surface (surface to which the lead terminal 21 is connected) of the aluminum plate constituting the diode connection portion 11. A plating layer 13 having a laminated structure is formed.

Note that the plating layer 13 may be formed only on the back surface of the diode connection portion 11, or may be formed on both the front surface and the back surface of the diode connection portion 11. Further, the plating layer 13 may be formed on the entire aluminum plate constituting the entire terminal board 10. Moreover, the plating layer 13 is not limited to two layers, and may be only one layer or three or more layers.

As described above, the terminal plate 10 is formed with a pair of insertion holes 15 and a pair of insertion holes 16. As shown in FIG. 2, the pair of insertion holes 16 are formed so as to sandwich the solder connection portion between the output lead wire 2 and the first terminal portion 12a. Therefore, by forming the pair of insertion holes 16, the solder can be blocked by the pair of insertion holes 16 when the solder is applied and spreads wet.

Further, the output terminal plate and the non-output terminal plate can be formed by sheet-metal processing of an aluminum plate having the same shape, and the output terminal plate is crimped to the non-output terminal plate 17. Is a shape further formed.

[3. Effect etc.]
FIG. 9 is a perspective view of a terminal board 10X used in a conventional terminal box. As shown in FIG. 9, the diode connection part 11X of the conventional terminal board 10X is connected only to one terminal part among the terminal parts on both sides in the Y-axis direction of the diode connection part 11X. For this reason, the heat flow conducted from the bypass diode 20 to the diode connection portion 11X via the lead terminal 21 is only in one direction (Y-axis positive direction). That is, the heat of the diode connection part 11X is conducted only in the direction of the terminal part connected to the diode connection part 11X. For this reason, when a bypass current flows through the bypass diode 20, heat stays in the bypass diode 20 and the diode connection portion 11X. Therefore, it is difficult to ensure sufficient heat dissipation of the terminal box while suppressing the amount of material used in the housing 30.

On the other hand, in the terminal plate 10 according to the present embodiment, as shown in FIG. 6, the pair of first terminal portions 12 a and the second terminal portions 12 b are provided from both ends of the diode connecting portion 11 in the Y-axis direction. It has been extended. Thus, the diode connection part 11 has a bridge structure connected to both of the pair of first terminal parts 12a and second terminal parts 12b. Thereby, the heat of the diode connection part 11 can be conducted to both the 1st terminal part 12a side and the 2nd terminal part 12b side.

When the bypass diode 20 generates heat, the diode connection portion 11 connected to the lead terminal 21 becomes a heat source in the terminal plate 10. According to this structure, since both the 1st terminal part 12a and the 2nd terminal part 12b are connected with the diode connection part 11, the heat-transfer path | route from the diode connection part 11 is the 1st terminal part from the diode connection part 11. Two paths, a path to 12a and a path from the diode connection portion 11 to the second terminal portion 12b, can be secured. For this reason, compared with the conventional terminal board 10X which has only one heat transfer path from the diode connection part 11, heat retention in the diode connection part 11 can be suppressed, and rapid heat conduction is performed. Can do. As a result, the heat dissipation of the terminal board 10 can be remarkably improved. Furthermore, from the viewpoint that the heat dissipation efficiency of the terminal board 10 is improved by the heat dissipation from the first terminal portion 12a and the second terminal portion 12b, the amount of material used for the heat dissipation of the terminal box 1 can be suppressed, thereby realizing cost reduction. it can.

Further, it is preferable that the surface area A1 of the first terminal portion 12a and the surface area A2 of the second terminal portion 12b are substantially equal.

Thereby, since the surface area of the terminal board 10 contributing to heat radiation becomes substantially equal for each path, the heat radiation distribution of the terminal board 10 is symmetric with respect to the diode connection portion 11. Therefore, since the heat radiation of the terminal board 10 can be made uniform in the Y axis positive direction and the negative direction, the heat radiation efficiency can be optimized.

In addition, each of the plurality of terminal plates 10 is a folded portion that extends in the top surface direction or the bottom surface direction (Z-axis direction) of the housing 30 at a position facing the terminal plate 10 adjacent in the second direction (X-axis direction). 14, and the height of the folded portion 14 included in one terminal plate 10 is the height of the folded portion 14 included in the terminal plate 10 disposed outside the one terminal plate 10 in the housing 30. It may be more than that.

One bypass diode 20 is connected to the terminal plate 10 arranged at the end in the housing 30, whereas two bypass diodes 20 are connected to the terminal plate 10 arranged inside the housing 30. Are connected. For this reason, the amount of heat flowing into the inner terminal plate 10 is approximately twice the amount of heat flowing into the end terminal plate 10. On the other hand, by making the height of the folded portion 14 of the inner terminal plate 10 equal to or higher than the height of the folded portion 14 of the terminal plate 10 on the end side, the heat dissipation efficiency of the inner terminal plate 10 is further increased. It can be made high, and heat retention at the central part of the housing can be suppressed. Further, since the surface areas of the first terminal portion 12a and the second terminal portion 12b can be adjusted by the height of the folded portion 14, the arrangement pitch in the X-axis direction of the terminal plate 10 at the center portion of the housing can be reduced. The size of the terminal box 1 can be reduced. Moreover, since the folding | returning part 14 of the terminal board 10 by the side of a housing | casing can be made lower, the material reduction of the terminal board 10 can be achieved.

[4. Modified example]
FIG. 10 is a perspective view of a terminal board 10A according to Modification 1 of the embodiment. As illustrated in FIG. 10, the terminal plate 10 </ b> A is a folded portion that extends in the top surface direction or the bottom surface direction (Z-axis direction) of the housing 30 at a position facing a terminal plate adjacent in the second direction (X-axis direction). 14A. Here, the folded portion 14A may have a plurality of cut shapes at the end of the folded portion 14A.

This makes it possible to increase the surface area of the cross section in the thickness direction of the folded portion 14A, and to improve the heat dissipation efficiency from the folded portion 14A.

FIG. 11 is a perspective view of a terminal board 10B according to the second modification of the embodiment. As shown in FIG. 11, the terminal plate 10 </ b> B is a folded portion that extends in the top surface direction or the bottom surface direction (Z-axis direction) of the housing 30 at a position facing a terminal plate adjacent in the second direction (X-axis direction). 14 and 18. Here, the heights of the turn-

back portions

14 and 18 may be so low that they are separated from the center point of the diode connection portion 11 in the first direction (Y-axis direction) in the first direction (Y-axis direction). In the present modification, the folded portion 18 is higher than the folded portion 14.

This makes it possible to increase the height of the folded portion in the vicinity of the diode connection portion 11 that generates the largest amount of heat, thereby improving the heat dissipation efficiency.

In the present modification, the folded portion 14 extends from the first terminal portion 12a and the second terminal portion 12b, and the folded portion 18 extends from the diode connection portion 11, and the height of the folded portion 18 is increased. Exemplifies a configuration that is higher than the height of the folded portion 14. However, the present invention is not limited to this configuration example, and the folded portion 14 extended from the first terminal portion 12a and the second terminal portion 12b is separated from the center point of the diode connection portion 11 in the first direction (Y-axis direction). The structure which becomes low may be sufficient.

FIG. 12 is a perspective view of a terminal board 10C according to Modification 3 of the embodiment. As illustrated in FIG. 12, the terminal board 10 </ b> C may have a bent portion 14 </ b> C that contacts the bypass diode 20 and holds the bypass diode 20 by elasticity. The bent portion 14C is, for example, continuous with the folded portion 14 and has a structure that can move in the Y-axis direction.

Thereby, since the bypass diode 20 can be temporarily held on the terminal plate 10C, the workability of the connection (soldering) process between the lead terminal 21 of the bypass diode 20 and the diode connecting portion 11 can be improved. Furthermore, since the heat transfer path from the bypass diode 20 via the bent portion 14C is formed, the heat dissipation path can be increased, and the heat dissipation efficiency can be further increased.

FIG. 13A is a front view showing a state in which a terminal box cover according to Modification 4 of the embodiment is removed. As illustrated in FIG. 13A, the housing 30A may have a recess 33 that is recessed toward the center of the housing 30A.

This makes it possible to reduce the distance between the central portion of the terminal box where heat generation is most concentrated and the outside air, thus realizing efficient heat dissipation to the outside of the terminal box.

FIG. 13B is a front view illustrating a state in which the terminal box cover according to the fifth modification of the embodiment is removed. As illustrated in FIG. 13B, the housing 30B may have heat radiation fins 34 on the outer surface facing the center of the housing 30B.

As a result, the cooling fins 34 are formed on the outer surface of the casing facing away from the central portion of the terminal box where heat generation is most concentrated, thereby increasing the contact area with the outside air of the terminal box. Efficient heat dissipation to the outside can be realized. In addition, as shown to FIG. 13B, it is preferable that the radiation fin 34 is formed in the recessed part depressed toward the center part of the housing | casing 30B. Thereby, further efficient heat dissipation to the exterior of a terminal box is realizable.

FIG. 13C is a front view illustrating a state in which a terminal box cover according to Modification 6 of the embodiment is removed. As illustrated in FIG. 13C, the terminal box may further include a convex structure 35 that is disposed between the plurality of terminal plates 10 to maintain the interval between adjacent terminal plates.

Thereby, even when the number of the terminal boards 10 arranged in the terminal box is changed, the terminal boards 10 having the same shape can be used together, so that the molding die of the terminal board 10 and the types of the terminal boards 10 can be reduced.

In addition, it is preferable that the convex structure 35 disposed between the plurality of terminal boards 10 has higher thermal conductivity than the sealing member filled in the housing. Thereby, the filling amount of the sealing member can be reduced and the heat radiation efficiency can be improved.

[5. Example]
Next, the result of comparative examination of the heat transfer state inside the terminal box according to the present embodiment using the terminal box according to the example and the comparative example is shown. More specifically, the temperature distribution in the terminal box was calculated by simulation by setting the thermal conductivity of each component arranged in the terminal box. Table 1 below shows parameters such as the thermal conductivity of each component used in this simulation.

FIG. 14 is a diagram comparing temperature distributions of the terminal boxes according to the example and the comparative example. 14, the comparative example is a terminal box in which five conventional terminal boards 10X shown in FIG. 9 are arranged, and Example 1 is a terminal board 10 according to the present embodiment shown in FIG. Is a terminal box 1 in which five are arranged. Here, the terminal board 10X according to the comparative example and the terminal board 10 according to the first embodiment are set to have substantially the same weight. In addition, Example 2 is a terminal box in which five terminal boards according to the present embodiment are arranged. The length of the second terminal portion 12b is 5.4 mm shorter than that of Example 1, and the folded back. The height of the part 14 is 3 mm lower. That is, the surface area of the terminal board according to Example 2 is smaller than the surface area of the terminal board according to Comparative Example and Example 1. As a result, the weight of the terminal board according to the second embodiment is reduced by 37% compared to the weight of the terminal board 10X according to the comparative example.

The lower part of FIG. 14 shows the junction temperature of each bypass diode 20 as a parameter indicating the temperature distribution in the terminal box. In both the comparative example, Example 1 and Example 2, the junction temperatures T _D2 and T _D3 of the bypass diodes D2 and D3 disposed on the center side are the junction temperatures T _{D1 of} the bypass diodes D1 and D4 disposed on the end side. And higher than _TD4 . It can also be seen that the junction temperatures T _D1 to T _D4 of the terminal box 1 according to the first embodiment are lower than the junction temperatures T _D1 to T _{D4 of the} terminal box according to the comparative example and the second embodiment.

FIG. 15 is a graph showing the temperature distribution of the bypass diode 20 according to the example and the comparative example. The graph shown in FIG. 15 is a plot of the junction temperatures T _D1 to T _D4 of the bypass diodes D1 to D4 shown in FIG.

14 and 15, the terminal box 1 according to the first embodiment can reduce the junction temperature of the bypass diode 20 as a whole as compared with the terminal box according to the comparative example. The difference in temperature distribution is that, in the terminal box according to the comparative example, the diode connection portion 11X is connected only to the first terminal portion, whereas in the terminal box 1 according to the first embodiment, the first terminal portion 12a. It can be considered that both the second terminal portion 12 b and the second terminal portion 12 b are connected to the diode connection portion 11. That is, in the terminal box 1 according to the first embodiment, the heat transfer path from the heat source includes the path from the diode connection part 11 to the first terminal part 12a and the path from the diode connection part 11 to the second terminal part 12b. Two routes can be secured. For this reason, compared with the terminal board 10X which concerns on the comparative example which has only one heat-transfer path | route from the said heat source, the residence of the heat | fever in the diode connection part 11 can be suppressed, and rapid heat conduction is performed. Can do. As a result, the heat dissipation of the terminal board 10 can be remarkably improved.

Further, the terminal box according to Example 2 is compared with the terminal box according to Example 2 and the surface area of the terminal plate according to Example 2 is reduced by 37%, but the terminal box according to Example 2 is compared. It can be seen that the temperature distribution of the bypass diode 20 similar to the terminal box according to the comparative example can be maintained.

That is, in the terminal box according to the second embodiment, similarly to the terminal box according to the first embodiment, both the first terminal portion 12a and the second terminal portion 12b are connected to the diode connection portion 11, and therefore, transmission from the heat source is performed. Two heat paths can be secured. For this reason, compared with the terminal board 10X which concerns on a comparative example, since the residence of the heat | fever in the diode connection part 11 can be suppressed, the amount of material usage required for the heat dissipation of a terminal box can be suppressed as a result. Therefore, cost reduction can be realized as compared with a terminal box having a conventional terminal plate configuration.

Next, the result of examining the ratio of the surface areas of the first terminal portion 12a and the second terminal portion 12b in the terminal plate 10D according to the present embodiment will be described.

FIG. 16A is a diagram illustrating dimensions of the terminal plate 10D when the surface area ratio of the first terminal portion 12a and the second terminal portion 12b is changed. As shown in FIG. 16A, terminal plate 10D is assumed to have a structure in which diode connection portion 11 is flush with first terminal portion 12a and second terminal portion 12b (positions in the Z-axis direction are equal). In changing the surface area ratio of the first terminal portion 12a and the second terminal portion 12b of the terminal plate 10D, the length L _{L of} the first terminal portion 12a in the Y-axis direction and the length of the second terminal portion 12b in the Y-axis direction. The ratio with _LR was changed. By changing this ratio, the maximum temperature in the terminal box was calculated by the same method as in the simulation described above. The width W 30 in the X-axis direction of the housing ₃₀ is 30 mm, the length L ₃₀ in the Y-axis direction of the housing 30 is 50 mm, the thickness W _f and t ₃₀ of the housing ₃₀ is 5 mm, and the Y-axis of the terminal plate 10D X-axis direction of the direction of the length _{L 10} 35 mm, the width _{W 10} of the X-axis direction of the terminal board 10D 15 mm, X-axis direction 5mm width _{W C} of the diode connection portion 11, a housing 30 and the terminal plate 10D 2.5mm spacing _{G X} of the housing 30 and the Y-axis direction between _{G L} and 2.5mm between the

terminal plate

10D, 2 mm spacing _{G H} in the Z axis direction between the bottom surface and the terminal plate 10D of the housing 30 The size of the heat source was assumed to be 1 mm × 1 mm.

FIG. 16B is a graph showing the heat dissipation characteristics of the terminal board when the surface area ratio of the terminal board according to the embodiment is changed. The horizontal axis of the figure represents the heating element position X, and the vertical axis represents the maximum temperature of the heating element in the housing 30. Here, the heating element position X is the distance between the center point of the diode connection portion 11 and the reference point when the end of the terminal plate 10D on the Y axis positive direction side is used as the reference point.

From the graph of FIG. 16B, when the center point in the Y-axis direction of the diode connection portion 11 is the center portion in the Y-axis direction of the terminal board 10D (X = 17.5 mm), the maximum temperature of the heating element is the lowest. You can see that That is, the surface area A1 of the first terminal portion 12a and the surface area A2 of the second terminal portion 12b are preferably substantially equal. This is because the surface area of each terminal portion that contributes to heat dissipation is substantially the same for each heat dissipation path, so that the heat dissipation distribution in the Y-axis direction of the terminal plate 10D is relative to the center point (diode connection portion 11) of the terminal plate 10D. This is thought to be due to symmetry. Thereby, the thermal radiation efficiency of terminal board 10D can be optimized.

It is desirable that the junction temperature for normal operation of the bypass diode 20 is 200 ° C. or less. From this viewpoint, in FIG. 16B, the heating element position X is preferably 12.5 mm or more and 22.5 mm or less. In other words, the heating element position X is preferably within a range of ± 5 mm from the center point of the terminal board 10D. That is, the distance between the center point of the diode connection portion 11 in the first direction (Y-axis direction) and the center point of the terminal plate 10D in the first direction (Y-axis direction) is the terminal plate in the first direction (Y-axis direction). the length _{L 10} of 10D, which is preferably arranged within a range of ± 15%.

Thereby, the surface area of the terminal board 10D that contributes to heat dissipation becomes substantially equal for each path, and the heat dissipation distribution can be made uniform. As a result, the maximum temperature of the bypass diode 20 can be suppressed to 200 ° C. or lower. Therefore, the heat dissipation efficiency of the terminal board 10D can be optimized while ensuring the operation of the bypass diode 20.

In the examination of the surface area ratio of the first terminal portion 12a and the second terminal portion 12b described above, the diode connection portion 11 is flush with the first terminal portion 12a and the second terminal portion 12b in FIGS. 16A and 16B. (A position in the Z-axis direction is equal) was assumed (see terminal board 10B in FIG. 11). However, the examination result of the ratio of the surface areas of the first terminal portion 12a and the second terminal portion 12b described above is that the diode connection portion 11 as shown in FIGS. 6 and 7 is the first terminal portion 12a and the second terminal portion. It is applicable also to the terminal board 10 which has a structure which is not flush with 12b (the position in the Z-axis direction is different). In the terminal plate 10 having a structure in which the diode connection part 11 and the first terminal part 12a and the second terminal part 12b are not flush with each other, the diode connection part 11 and the first terminal part 12a, and the diode connection part 11 Connection portions extending in the Z-axis direction exist between the second terminal portions 12b, and these connection portions become a part of the heat dissipation path. Therefore, in this case, the heat radiation path length in the first direction can be regarded not as the distance in the first direction viewed from the Z-axis direction but as the development distance in the first direction.

In other words, the terminal plate 10D has a structure in which the diode connection portion 11 is flush with the first terminal portion 12a and the second terminal portion 12b, and the diode connection portion 11 faces the first terminal portion 12a and the second terminal portion 12b. In both of the terminal plates 10 having a structure that is not one, the development distance between the center point of the diode connection part 11 in the first direction (Y-axis direction) and the center point of the terminal plate 10 in the first direction (Y-axis direction) is against developed length L ₁₀ of the terminal plate 10 in a first direction (Y axis direction), which is preferably arranged within a range of ± 15%.

Thereby, the heat dissipation efficiency of the

terminal boards

10 and 10D can be optimized while the operation of the bypass diode 20 is guaranteed.

(Other embodiments)
As mentioned above, although the terminal box concerning the present invention was explained based on an embodiment, the present invention is not limited to the above-mentioned embodiment.

For example, in the above-described embodiment, the number of the

terminal boards

10, 10A, 10B, and 10C arranged in the terminal box 1 is five, but the present invention is not limited to this. The number of terminal boards 10 to 10C may be two, three or four, or may be six or more. That is, the number of terminal plates 10 to 10C arranged in the terminal box 1 may be plural.

In the above-described embodiment, the second terminal portion 12b of the terminal plate 10 that is the output terminal plate and the external connection cable 3 are connected by the crimp bonding portion 17, but the present invention is not limited to this. For example, the second terminal portion 12b and the external connection cable 3 may be connected by solder in the same manner as the connection mode between the first terminal portion 12a and the output lead wire 2. Further, the connection between the first terminal portion 12a and the output lead wire 2 is not limited to the solder connection.

In the above embodiment, the plating layer 13 is formed on the terminal board 10, but the plating layer 13 is not necessarily formed.

In addition, it is realized by arbitrarily combining the components and functions in the above-described embodiment without departing from the gist of the present invention, and forms obtained by making various modifications conceived by those skilled in the art. Forms are also included in the present invention.

DESCRIPTION OF SYMBOLS 1

Terminal box

10, 10A, 10B, 10C, 10D Terminal board 11 Diode connection part 12a 1st terminal part 12b 2nd

terminal part

14, 14A, 18 Folding part 14C Bending part 20 Bypass diode 21

Lead terminal

30, 30A, 30B Body 33 Concavity 34 Radiation fin (heat dissipation structure)
35 Convex structure 100 Solar cell module

Claims

A terminal box for a solar cell module,
A housing,
A plurality of terminal boards disposed inside the housing;
A bypass diode disposed between adjacent terminal plates, and
Each of the plurality of terminal boards is
A diode connection connected to the lead terminal of the bypass diode;
A terminal having a pair of first and second terminal portions extending from each of both end portions of the diode connecting portion in a first direction intersecting with an arrangement direction of the plurality of terminal plates box.
The terminal box according to claim 1, wherein a surface area of the first terminal portion and a surface area of the second terminal portion are substantially equal.
In each of the plurality of terminal boards,
The development distance between the center point of the diode connection portion in the first direction and the center point of the terminal plate in the first direction is within a range of ± 15% with respect to the development length of the terminal plate in the first direction. The terminal box of Claim 1 or 2 arrange | positioned in.
Each of the plurality of terminal boards is
In the position facing the terminal board adjacent in the arrangement direction, it has a folded portion extending in the top surface direction or the bottom surface direction of the housing,
The height of the folded portion included in one terminal plate is equal to or greater than the height of the folded portion included in the terminal plate disposed outside the one terminal plate in the housing. The terminal box according to item 1.
Each of the plurality of terminal boards is
In the position facing the terminal board adjacent in the arrangement direction, it has a folded portion extending in the top surface direction or the bottom surface direction of the housing,
The terminal box according to any one of claims 1 to 4, wherein the folded portion has a plurality of cut shapes at an end portion of the folded portion.
Each of the plurality of terminal boards is
In the position facing the terminal board adjacent in the arrangement direction, it has a folded portion extending in the top surface direction or the bottom surface direction of the housing,
The terminal box according to any one of claims 1 to 5, wherein a height of the folded portion decreases as the distance from the center point of the diode connection portion in the first direction increases in the first direction.
Each of the plurality of terminal boards is
The terminal box according to any one of claims 1 to 6, further comprising a bent portion that contacts the bypass diode and elastically holds the bypass diode.
The terminal box according to any one of claims 1 to 7, wherein the casing has a concave portion that is recessed toward a central portion of the casing.
The terminal box according to any one of claims 1 to 8, wherein the casing has a fin-shaped heat dissipation structure on an outer surface facing away from a central portion of the casing.
further,
The terminal box according to any one of claims 1 to 9, further comprising a convex structure that is disposed between the plurality of terminal plates and maintains an interval between adjacent terminal plates.