JP5523227B2 - Terminal box for solar cell module - Google Patents

Description

  The present invention relates to a terminal box for a solar cell module including a bypass diode for bypass at the time of reverse load that bypasses a solar cell output for the purpose of preventing destruction of solar cells due to a backflow current.

  In the photovoltaic power generation system, DC power from a plurality of solar cell modules laid on the roof of a house is supplied to each electrical appliance via an inverter or the like. The plurality of solar cell modules are configured to be connected in series via a solar cell module terminal box (hereinafter simply referred to as a terminal box) disposed on the back side of each solar cell module.

  As a conventional terminal box, a plurality of terminal boards that are arranged in parallel inside the housing, one end is connected to the output lead drawn from the back side of the solar cell module and the other end is connected to the module connecting cable And a bypass diode for reverse load that is bridged between the terminal plates are known.

  In a solar cell module, when some solar cells are shaded and are not exposed to sunlight and are in a non-power generation state, a current in the reverse direction is generated from the solar cells in a power generation state. Flow and may destroy the cell. In order to prevent the destruction of the solar battery cell due to such a reverse current, a diode for preventing the reverse current called a bypass diode is usually connected. The bypass diode generates heat when a current flows so as to bypass the unpowered solar cell. If this heat cannot be sufficiently released, there is a risk of damage exceeding the rated temperature.

  On the other hand, when installing a solar cell module on the roof of a house, etc., it is usually mounted on a mount using a mounting bracket, but on the back side of the solar cell module, the above bypass diode and connection terminal are protected from the external environment. A terminal box is installed. This terminal box is usually manufactured by molding from a thermoplastic material (see, for example, Patent Document 1).

International Publication No. 2005/088732

  However, as described above, the bypass diode generates heat when a current flows so as to bypass the unpowered solar cell. When the terminal box is made of a thermoplastic material as in the prior art, the terminal box may be deformed so that the distance between the terminal boards is widened. In such a case, stress concentrates on the leg electrode of the bypass diode that is bridged between the terminal plates. And when a deformation | transformation of the terminal box is large, since there exists a possibility that a bypass diode may be damaged, the improvement was desired.

  The present invention has been made in view of the above, and even when the temperature of the bypass diode changes, such as when the bypass diode generates heat, no stress acts on the leg electrode of the bypass diode. It is an object of the present invention to provide a solar cell module terminal box that can prevent breakage and improve reliability.

  In order to solve the above-described problems and achieve the object, a terminal box for a solar cell module according to the present invention includes a first terminal plate and a first terminal plate that are provided in the box body and connected to output lead wires extending from the solar cell module. 2 terminal plate, a resin-sealed sealing portion, and a first leg electrode and a second leg electrode extending from the sealing portion, and the sealing portion is used as the first terminal plate. A reverse load bypass rectifier element fixed, connected to the first terminal plate with the first leg electrode, and connected to the second terminal plate with the second leg electrode. The terminal plate and the second terminal plate are supported by a positioning component that does not have thermal softening properties so that a change in the interval between them is restricted by a temperature change.

  According to the present invention, the first terminal plate to which the sealing portion of the rectifying element is fixed and the second terminal plate to which the leg electrode of the rectifying element is connected are formed by the positioning component that does not have thermal softening properties. Since the change in the distance between each other due to temperature changes is supported and supported, even if the temperature inside the terminal box changes, such as when the rectifier element generates heat, stress is applied to the leg electrodes of the rectifier element. This prevents the rectifying element from being damaged, thereby improving the reliability.

FIG. 1 is a perspective view showing a solar cell module to which a solar cell module terminal box according to Embodiment 1 of the present invention is applied. FIG. 2 is a perspective view of the solar cell module in which the solar cell module terminal box according to Embodiment 1 of the present invention is disposed as viewed from the back side. FIG. 3 is a front view of the terminal box with the lid removed. FIG. 4 is a front view of the rectifying element (bypass diode). FIG. 5 is a front view of a terminal box from which a cover, a terminal plate, and a heat radiating plate are removed from a terminal box for a solar cell module according to Embodiment 2 of the present invention. FIG. 6 is a front view of the terminal box from which the lid of the terminal box for a solar cell module according to Embodiment 3 of the present invention is removed. FIG. 7 is a diagram illustrating a state in which the terminal plate having a cross-sectional view along the line AA in FIG. 6 is engaged with the connecting member. FIG. 8 is a side view, partly in section, showing the relationship between a diode according to Embodiment 4 of the present invention and members that support it. FIG. 9 is a side view, partly in section, illustrating the relationship between a diode according to Embodiment 5 of the present invention and a member that supports the diode.

  Hereinafter, embodiments of a terminal box for a solar cell module according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a solar cell module to which a solar cell module terminal box according to Embodiment 1 of the present invention is applied. FIG. 2 is a perspective view of the solar cell module in which the solar cell module terminal box according to Embodiment 1 of the present invention is disposed as viewed from the back side. The solar cell module 100 includes a large number of solar cells 12 connected in series, a front cover member having high translucency, a back cover member 14 having excellent weather resistance, and a resin encapsulated between them. For the solar cell module that is attached to the back cover member 14 and constitutes the output portion of the solar cell module 100, the solar cell panel protected by the above, a rectangular frame-shaped aluminum support frame 13 that supports the solar cell panel And a terminal box (hereinafter simply referred to as a terminal box) 20.

  The terminal box 20 has a substantially box-shaped casing that constitutes an outer shell, and further includes a box body 20A and a lid body 20B. The substantially plate-shaped lid body 20B closes the open surface of the box body 20A having a substantially rectangular parallelepiped box shape that opens one surface. In the present embodiment, at least the box body 20A of the terminal box 20 is made of a material having no thermoplasticity (thermosoftening property) such as a thermosetting resin or ceramic. The output part of the solar cell module 100 is accommodated in the housing. To this output portion, module connection cables (external cables) 16A and 16B extending to the outside are connected for the purpose of taking out the output of the solar cell module 100 and for the purpose of connecting to other solar cell modules. 16A is the + side of the solar cell, 16B is the-side of the solar cell, and each is connected to another solar cell module.

  FIG. 3 is a front view of the terminal box 20 with the lid 20B removed. FIG. 4 is a front view of the rectifying element (bypass diode). The box body 20 </ b> A has a substantially rectangular parallelepiped box shape, has a bottom surface and an outer surface 2 surrounding the four sides, and has an inner surface 3 that accommodates an output portion inside the outer surface 2. A rectangular lead wire inlet 20a is opened along the side at the upper end of the bottom of the box body 20A, for example, in FIG. An output lead wire (not shown) extending from the inside of the solar cell panel is inserted through the lead wire inlet 20a. Specifically, the output lead wire is a flat copper wire having a surface plated with solder. On the other hand, a cable lead-out hole 20b for pulling out the module connecting cables 16A and 16A is formed on the side surface opposite to the lead wire lead-in port 20a.

  The output unit is configured to include two bypass diodes (hereinafter simply referred to as diodes) 8A and 8B and three terminal plates 1A, 1B and 1C as rectifying elements for bypass during reverse load. The inside of the inner side surface 3 surrounding the output portion is finally filled with a waterproof filler after the completion of the wiring connection.

  Terminal mounting portions 7A, 7B, and 7C projecting from the bottom surface of the box body 20A protrude into the box body 20A, and the three terminal plates 1A, 1B, and 1C made of a conductive material are themselves The terminal mounting portions 7A, 7B, and 7C are inserted into the mounting holes that are perforated, and fixed to the terminal mounting portions 7A, 7B, and 7C, respectively. The terminal boards 1A, 1B, and 1C are arranged in parallel in the horizontal direction in the drawing, and each has a long shape extending in the vertical direction in the drawing. A lead wire connecting portion 1a to which an output lead wire inserted through the lead wire lead-in port 20a is soldered is provided at the upper end of each terminal plate 1A, 1B, 1C in the figure. Output lead wires extending from one end of the plurality of solar cells 12 connected in series are joined to the lead wire connecting portion 1a. On the other hand, among the three terminal boards 1A, 1B, 1C, a cable connecting portion to which the module connecting cable 16A is crimped and joined is provided at the lower end of the two terminal boards 1A at the left and right ends in the figure.

  The diodes 8A and 8B are arranged in a direction orthogonal to the arrangement of the three terminal plates 1A, 1B, and 1C. As shown in FIG. 4, the diode 8A includes a sealing portion 8a in which a semiconductor element is resin-sealed with an insulating resin material and leg electrodes 8b and 8c extending from the sealing portion 8a. On the opposite side of the leg electrodes 8b and 8c, fixing holes 8d for fixing with rivets or the like are formed. The sealing portion 8a has a rectangular flat shape and a heat sink is exposed on one main surface in order to improve heat dissipation. The other diodes 8B have the same configuration. The diodes 8A and 8B have a rectifying function based on a PN junction, and the two leg electrodes 8b and 8c are an N pole and a P pole, respectively. The two leg electrodes 8b and 8c are bridged across the terminal boards.

  The diode 8A is supported on the terminal plate 1A, and the sealing portion 8a of the diode 8A is fixed to the terminal plate 1A by the rivet 2a. A leg electrode 8b having a polarity on the N side of the diode 8A is soldered and electrically connected to the terminal board 1A. A diode leg electrode 8c having a polarity on the P side of the diode 8A extends to the adjacent terminal board 1B and is soldered to be electrically connected. The terminal board 1A and the cable 7 are connected by crimping and electrically connected.

  The diode 8B is supported on the terminal plate 1B, and the sealing portion 8a of the diode 8B is fixed to the terminal plate 1B by the rivet 2b. A leg electrode 8b having a polarity on the N side of the diode 8B is soldered and electrically connected to the terminal board 1B. A diode leg electrode 8c having a polarity on the P side of the diode 8B extends to the adjacent terminal plate 1C and is soldered to be electrically connected. The diode 8A bridges between the terminal plate 1A and the terminal plate 1B to prevent reverse current flowing between them. The diode 8B bridges between the terminal plate 1B and the terminal plate 1C to prevent a reverse current flowing between them.

  According to the present embodiment, the box body 20A is made of a material that does not have thermoplasticity (thermosoftening properties) such as thermosetting resin or ceramic. It does not change. Further, the distance between the terminal plate mounting portions 7A and 7B molded integrally with the box body 20A does not change with temperature. As a result, the gap between the terminal plate 1A supporting the sealing portion 8a of the diode 8A and the terminal plate 1B supporting the leg electrode 8c of the diode 8A is made of a material having no thermoplasticity (thermosoftening property). The box body 20A is positioned with the change in the distance between the box bodies 20A regulated, so that the stress acting on the leg electrodes 8c is reduced. The same applies to the diode 8B.

Embodiment 2. FIG.
FIG. 5 is a front view of a terminal box from which a cover, a terminal plate, and a heat radiating plate are removed from a terminal box for a solar cell module according to Embodiment 2 of the present invention. In the present embodiment, the positioning component 6 that reduces the stress acting on the leg electrodes is integrally formed on the bottom surface of the box body 20A. The positioning component 6 is a portion in which light ink as shown in FIG. 5 is put, and includes a part of the bottom surface of the box main body 20A and terminal mounting portions 7A, 7B, and 7C standing upright therefrom. The positioning component 6 is made of a material having no thermoplasticity (thermosoftening property) such as thermosetting resin or ceramic. Other configurations are the same as those of the first embodiment.

  The above structure is obtained by integrally molding (insert molding) the positioning component 6 when molding the resin box body 20A. Specifically, the positioning component 6 is loaded into a molding die at the time of resin molding of the box body 20A, and molten resin is injected into the remaining space in the molding die so that at least a part thereof is wrapped with resin. Molded integrally with the box body 20A.

  The positioning component 6 may be integrally formed on the bottom surface of the box body 20A as described above, but may be manufactured separately from the box body 20A and attached to the box body 20A by bonding or screwing. .

  According to the present embodiment, the space between the terminal plate 1A that supports the sealing portion 8a of the diode 8A and the terminal plate 1B that supports the leg electrode 8c of the diode 8A has thermoplasticity (thermosoftening property). By the positioning component 6 made of a non-material, positioning is performed while the change in the mutual interval is restricted, so that the stress acting on the leg electrode 8c is reduced. The same applies to the diode 8B.

Embodiment 3 FIG.
FIG. 6 is a front view of the terminal box from which the lid of the terminal box for a solar cell module according to Embodiment 3 of the present invention is removed. FIG. 7 is a diagram illustrating a state in which the terminal plate having a cross-sectional view along the line AA in FIG. 6 is engaged with the connecting member. In the present embodiment, a connecting member 5 that positions the terminal plates 1A, 1B, and 1C relative to each other is provided as a positioning component that does not have heat softening properties. The connecting member 5 is made of a material that does not have thermoplasticity (thermosoftening properties) such as thermosetting resin or ceramic, and has three protruding portions 5a provided at both end portions and the central portion of the terminal plates 1A, 1B, 1C. Are respectively press-fitted into the engagement holes formed therein. Other configurations are the same as those of the first embodiment.

  According to the present embodiment, the space between the terminal plate 1A that supports the sealing portion 8a of the diode 8A and the terminal plate 1B that supports the leg electrode 8c of the diode 8A has thermoplasticity (thermosoftening property). The connecting member 5 made of a non-material is positioned with the change in the distance between the connecting members 5 being restricted, thereby reducing the stress acting on the leg electrode 8c. The same applies to the diode 8B.

Embodiment 4 FIG.
FIG. 8 is a side view, partly in section, showing the relationship between a diode according to Embodiment 4 of the present invention and members that support it. In the present embodiment, there is provided a heat radiating plate 15 made of a material having good heat conductivity that spreads along the bottom surface of the box body 20A. The heat radiating plate 15 spreads in close contact with the entire bottom surface of the box body 20A, and a terminal mounting portion 7B standing from the bottom surface of the box body 20A is passed through a hole formed on the main surface.

  The diode 8B is supported on the heat sink 15 and the sealing portion 8a of the diode 8B is directly fixed to the heat sink 15 by the rivet 2b. A leg electrode 8b having a polarity on the N side of the diode 8B is soldered and electrically connected to the terminal board 1B. A diode leg electrode 8c (not shown) having a polarity on the P side of the diode 8B extends to the adjacent terminal plate 1C and is soldered to be electrically connected.

  The diode 8B has one main surface (lower surface) of the sealing portion 8a brought into surface contact with the heat radiating plate 15 and fixed on the heat radiating plate 15, and the other main surface (upper surface) of the sealing portion 8a is fixed to the terminal plate 1B. Is sandwiched between the two in surface contact with each other. The heat radiating plate 15 is made of a material having good heat conductivity, extends substantially over the bottom surface of the box body 20A, and faces the solar cell module (not shown) via the bottom surface of the box body 20A. With this heat radiating plate 15, the heat of the sealing part 8a escapes to the solar cell module.

  As in the second embodiment, a part of the bottom surface of the box body 20A and the terminal mounting portion 7B erected therefrom are made of a material having no thermoplasticity (thermosoftening property) such as thermosetting resin or ceramic. ing.

  According to the present embodiment, the heat dissipation plate 15 that supports the sealing portion 8a of the diode 8B and the terminal plate 1B that supports the leg electrode 8b of the diode 8B have thermoplasticity (thermosoftening property). The terminal mounting portion 7B made of a non-material is positioned with the change in the distance between the terminal mounting portion 7B being restricted, thereby reducing the stress acting on the leg electrode 8b. The same applies to the diode 8A.

  In the present embodiment, the terminal mounting portion 7B regulates the change in the distance between the sealing portion 8a of the diode 8B and the terminal plate 1B. However, the heat sink 15 seals the diode 8B. The change of the space | interval between the part 8a and the terminal board 1C may be controlled, and a plurality of terminal attachment parts may be provided to perform both. Moreover, you may make it regulate the change of the space | interval between the terminal board 1B to which the leg part electrodes 8b and 8c of the diode 8B are connected, and the terminal board 1C.

Embodiment 5 FIG.
FIG. 9 is a side view, partly in section, illustrating the relationship between a diode according to Embodiment 5 of the present invention and a member that supports the diode. The positioning component 17 of the present embodiment is formed on a part of the box body 20A as in the second embodiment. The positioning component 17 is made of a material that does not have thermoplasticity (thermosoftening), and the positioning component 17 includes a portion constituting a part of the bottom portion of the box body 20A and a terminal mounting portion 7B that stands vertically from the portion. It is composed of

  The diode 8B is supported on the positioning component 17, and the sealing portion 8a of the diode 8B is directly fixed to the main surface of the positioning component 17 by the rivet 2b. A leg electrode 8b having a polarity on the N side of the diode 8B is soldered and electrically connected to the terminal board 1B. A diode leg electrode 8c (not shown) having a polarity on the P side of the diode 8B extends to the adjacent terminal plate 1C and is soldered to be electrically connected.

  According to the present embodiment, the gap between the sealing portion 8a of the diode 8B and the terminal plate 1B that supports the leg electrode 8b of the diode 8B is made of a material that does not have thermoplasticity (thermosoftening property). By the positioning component 17 being positioned while the change in the mutual interval is restricted, the stress acting on the leg electrode 8b is reduced. The same applies to the diode 8A.

  In the present embodiment, the positioning component 17 regulates the change in the distance between the sealing portion 8a of the diode 8B and the terminal plate 1B. However, the positioning component 17 is the sealing portion of the diode 8B. The change in the distance between 8a and the terminal board 1C may be regulated, or both of them may be performed. You may make it control the change of the space | interval between the terminal board 1B to which the leg part electrodes 8b and 8c of the diode 8B are connected, and the terminal board 1C.

  It should be noted that the present invention is not limited to the embodiments described in the first to fifth embodiments, and the portion between the member that supports the diode sealing portion and the member that supports the diode leg electrode has thermoplasticity (thermosoftening property). A predetermined effect can be obtained by regulating the change of the interval by the non-members and positioning them mutually.

  Further, the member supporting one leg electrode of the diode and the other leg electrode of the diode are supported not only between the member supporting the diode sealing portion and the member supporting the leg electrode of the diode. A predetermined effect can also be obtained by positioning the mutual change of the gap by a member having no thermoplasticity (thermosoftening property) between the members.

  As described above, the solar cell module terminal box according to the present invention is useful when applied to a solar cell module terminal box including a rectifying element for reverse load bypass that bypasses the solar cell output, and particularly heat generation. It is optimally applied to those equipped with a large amount of bypass rectifier.

1A, 1B, 1C Terminal board 1a Lead wire connection part 2 Outer side surface 3 Inner side surface 5 Connecting member (positioning part)
5a Convex part 6 Positioning parts 7A, 7B, 7C Terminal mounting part 8A, 8B Bypass diode (rectifier element)
8a Sealing portion 8b, 8c Leg electrode 8d Fixing hole 12 Solar cell 13 Support frame 14 Back cover member 15 Heat sink 16 Module connection cable (external cable)
17 Positioning parts 20 Terminal box 20A Box body 20B Lid 20a Lead wire inlet 20b, 20c Cable outlet 100 Solar cell module

Claims (1)

A terminal box constituting the output part of the solar cell module,
A rectangular parallelepiped box shape that opens one surface, a terminal mounting portion projects from the bottom, and a box body fixed to the solar cell module;
Has a mounting hole in which the terminal mounting portion is inserted, the juxtaposed inside said box body by said terminal mounting portion into the hole with said mounting is inserted, output lead extending from the solar cell modules are connected A terminal plate of 1 and a second terminal plate;
It consists of a resin-sealed sealing portion and a first leg electrode and a second leg electrode extending from the sealing portion, and the sealing portion is fixed to the first terminal plate, A rectifying element for bypass during reverse load, wherein a first leg electrode is connected to the first terminal plate and the second leg electrode is connected to the second terminal plate ;
It is made of a material that does not have thermoplasticity, and includes a connecting member that positions the first terminal plate and the second terminal plate ,
An engagement hole is formed in the first terminal plate and the second terminal plate,
The connecting member has a protrusion inserted into the engagement hole, and the protrusion is press-fitted into the engagement hole from above and is attached to the first terminal plate and the second terminal plate. A terminal box for a solar cell module that regulates a change in a distance between the first terminal plate and the second terminal plate .