JP5528277B2 - Terminal box for solar cell module and solar cell module - Google Patents

Description

  The present invention relates to a terminal box for a solar battery module including a bypass diode for bypassing a non-power generation cell that bypasses a solar battery output for the purpose of preventing destruction of unpowered solar battery cells.

  In a solar 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 connected in series with a module connection cable via a terminal box for solar cell modules (hereinafter simply referred to as a terminal box) arranged on the back side of each module.

  On the other hand, a solar cell module is generally produced by sealing a plurality of solar cells, the plurality of solar cells are connected in series by output lead wires, and the output lead wires are drawn out to a terminal box.

  The terminal box is composed of a plurality of terminal plates to which output lead wires drawn out from the solar cell module are connected at one end and a module connecting cable to the other end, and an unpowered cell bypass bridged between the terminal plates. And a bypass diode.

  In general, in a solar cell module, some solar cells are shaded, and when the solar cell enters an unpowered state without being exposed to sunlight, the unpowered solar cell functions as a resistor. When current flows from the cell, it may generate heat and destroy the cell. In order to prevent the destruction of such unpowered solar cells, an unpowered cell bypass diode called a bypass diode is usually connected. The bypass diode bypasses the unpowered solar cell to prevent the cell from being destroyed by flowing current, but generates heat at that time. If this heat cannot be sufficiently released, there is a risk of damage exceeding the rated temperature.

  In a terminal box, a bypass diode that is bridged between a plurality of terminal plates usually has the following configuration. In other words, the bypass diode is composed of an element main body having a rectifying function based on a PN junction and two leg electrodes extending from the element main body, and is connected to one of the two adjacent terminal plates. While supporting the element body, one of the leg electrodes is connected to this terminal plate, and the other of the leg electrodes is extended to the other terminal plate to bridge between the two terminal plates. That is, the element body of the bypass diode is mounted on the terminal board. The heat generated by the bypass diode is dissipated through the terminal board. Since it is such a structure, the proposal which aims at the improvement of heat dissipation by providing a fin structure in a terminal board etc. conventionally is proposed (for example, refer to patent documents 1).

  On the other hand, a terminal box may be filled with a potting material that is a heat conductive insulating resin for the purpose of waterproofing. This potting material is poured in between the components in a molten state without any gaps after the placement and wiring of the components in the terminal box are completed, and then hardened. Potting material seals the inside of the terminal box without any gaps and protects electrical components from rainwater.

JP 2006-269803 A

  According to the above conventional technique, the fin structure may be provided on the terminal board in order to improve the heat dissipation as described above. However, if the fin structure is provided on the terminal board, the wraparound of the potting material becomes worse. The air layer or the like is not formed between the parts without gaps, and the heat radiation performance may be reduced.

  The present invention has been made in view of the above, and an object of the present invention is to provide a solar cell module terminal box that improves the heat dissipation of the terminal plate and does not hinder the wraparound of the filler filled in the box body. And

  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 is a terminal box constituting an output part of a solar cell module, and is a box shape fixed to the solar cell module. Box body, a plurality of terminal plates with good heat conductivity connected to the output lead wires extending from the solar cell module in the box body, an element body mounted on the terminal board, and a leg portion extending from the element body A plurality of non-power generation cell bypass rectifier elements that are bridged between the terminal plates by the leg electrodes, and a filling material filled in the box body, the terminal plate having a bottom surface of the box body The upper and lower surfaces of the terminal plate are sealed with a filler, and when the filler is filled into the box body, a through hole through which the molten filler can circulate penetrates. And it is provided Te.

  According to the present invention, since the filler in the molten state circulates through the circulation holes by forming the circulation holes in the terminal plate, the fillers can be satisfactorily distributed without gaps between the parts, and no air layer is formed. , There is an effect that heat dissipation is further improved.

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 showing a state in which the terminal box is filled with a potting material (thermally conductive insulating resin). FIG. 5 is a front view of a rectifying element (bypass diode). FIG. 6 is a schematic circuit diagram showing a connection state around the terminal box. FIG. 7 is a front view of the terminal box from which the lid of the terminal box for a solar cell module according to Embodiment 2 of the present invention is removed. FIG. 8 is a cross-sectional view of a terminal board according to Embodiment 2 of the present invention. FIG. 9 is a cross-sectional view of another example of a terminal board shown for comparison. FIG. 10: is a front view of the terminal board of the terminal box for solar cell modules which concerns on Embodiment 3 of this invention. 11 is a cross-sectional view taken along line AA in FIG.

  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. In the solar cell module 100, a large number of solar cells 12 connected in series are sandwiched between a front cover member with high translucency and a back cover member 14 with excellent weather resistance, and between the cover members. Solar cell panel 15 sealed with injected resin, rectangular frame-shaped aluminum support frame 13 that supports solar cell panel 15, and output portion of solar cell module 100 attached to back cover member 14 It is comprised from the terminal box for solar cell modules (henceforth a simple terminal box) 20 which comprises.

  The terminal box 20 is made of a resin material such as plastic and has a substantially box shape constituting the outer shell. The terminal box 20 is further divided into a box body 20A and a lid 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. And the output part of the solar cell module 100 is accommodated in the inside of the box main body 20A. Module output cables (external cables) 16a and 16b extending to the outside are connected to the output unit for the purpose of taking out the output of the solar cell module 100 and for connecting to other solar cell modules.

  FIG. 3 is a front view of the terminal box 20 with the lid 20B removed. FIG. 4 is a front view showing the terminal box filled with a potting material (thermally conductive insulating resin) 4A. FIG. 5 is a front view of a rectifying element (bypass diode). FIG. 6 is a schematic circuit diagram showing a connection state around the terminal box.

  The box main body 20A has a substantially rectangular parallelepiped box shape, has a bottom surface and side surfaces that surround the four sides, and accommodates the output unit 4 of the solar cell module 100 therein. A rectangular lead wire inlet 20a is opened along the side at the upper corner of the bottom surface of the box body 20A shown in FIG. An output lead wire (not shown) extending from the inside of the solar cell panel 15 is inserted into the box body 20A 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, cable lead-out holes 20b and 20c for pulling out the module connecting cables 16a and 16b are formed on the side surface opposite to the lead wire lead-in port 20a.

  The output unit 4 includes three terminal plates (first to third terminal plates) 1A, 1B, and 1C for connecting external wires, and two bypass diodes (hereinafter simply referred to as diodes) 8A for bypassing the non-power generation cell. , 8B. Projections 7A, 7B, and 7C project from the bottom surface of the box body 20A. The three terminal boards 1A, 1B, and 1C are made of a material having good heat conductivity, and are inserted into the mounting holes that are perforated by the protrusions 7A, 7B, and 7C, and are fixed to the protrusions 7A, 7B, and 7C. A predetermined gap is provided between the box body 20A and the bottom surface of the box body 20A. The terminal boards 1A, 1B, 1C are arranged in parallel to each other in the left-right direction in FIG. 3, and each has a long shape extending in the up-down direction in the figure. At the upper end of each terminal plate 1A, 1B, 1C shown in FIG. 3, a lead wire connecting portion 1a to which an output lead wire inserted through the lead wire inlet 20a is soldered is provided. 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 (FIG. 6).

  On the other hand, of the three terminal boards 1A, 1B, and 1C, the cable connecting portion 1b is provided at the lower end of the two terminal boards 1A and 1C at the left and right ends in FIG. 3, and the module connection cables 16a and 16b are connected to each other. Crimped and joined. The cable connecting portion 1b is not provided at the lower end of the terminal board 1B shown in FIG. The lower end of the terminal board 1B shown in FIG. 3 is a large-area portion 1f that has a larger area than the other terminal boards 1A and 1C because heat dissipation is achieved and the width and length are both increased. And three flow holes 1e are perforated in this large area portion 1f. The flow hole 1e has a small diameter and is formed simultaneously with the outer shape of the terminal board 1B by, for example, press punching.

  As shown in FIG. 4, the potting material (filling material) 4A, which is a heat conductive insulating resin, is filled in the output part 4 of the box body 20A for the purpose of waterproofing. After the placement / wiring of the output unit 4 is completed and the potting material 4A is attached to the solar cell module, the potting material 4A flows in between the components in a molten state without any gap, and then hardens. At this time, the terminal plates 1A, 1B, 1C are sealed with the potting material 4A at the upper and lower surfaces. When the molten potting material 4A is poured, the potting material 4A flows through the flow hole 1e. In the present embodiment, the flow hole 1e is provided only in the terminal plate 1B, but the flow hole 1e may be provided in the other terminal plates 1A and 1C.

  As shown in FIG. 5, the diode 8A includes an element body 8a in which a semiconductor element is resin-sealed with an insulating resin material, and leg electrodes 8b and 8c extending from the element body 8a. The element body 8a has a rectangular flat shape and a heat sink is exposed on one main surface in order to improve heat dissipation. Other diodes 8B have the same configuration. The diodes 8A and 8B are mounted on the terminal plates 1A and 1B such that one main surface (lower surface) of the element body 8a is in surface contact with the terminal plates 1A and 1B, respectively.

  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. That is, the diodes 8A and 8B have the element body 8a supported by one of the two adjacent terminal plates, and one of the leg electrodes connected to the terminal plate, and the other of the leg electrodes. Is extended to the other terminal board side to bridge between the two terminal boards. The diode 8A bridges between the terminal plate 1A and the terminal plate 1B, and when there is an unpowered cell, bypasses it to prevent current from flowing into the unpowered cell. The diode 8B bridges between the terminal plate 1B and the terminal plate 1C, and when there is an unpowered cell, bypasses it to prevent the current from flowing into the unpowered cell (FIG. 6).

  In particular, the element body 8a of the diodes 8A and 8B is a heat source that generates heat. The module connecting cables 16a and 16b include metal wires, and have a heat dissipation function although not in large quantities. An element body 8a of a diode 8A is mounted on a terminal board (first terminal board) 1A, and a module connection cable 16a is connected thereto. The element body 8a of the diode 8B is mounted on the terminal board (second terminal board) 1B, and the module connection cable is not connected thereto. No diode is mounted on the terminal board (third terminal board) 1C, and the module connection cable 16b is connected thereto. That is, the terminal board 1B is in the most severe environment with respect to heat dissipation. In the present embodiment, the area opposite to the lead wire connecting portion 1a of the terminal plate 1B is made larger than the other terminal plates 1A and 1C, and the large-area portion 1f is provided to improve heat dissipation. It has been.

  As described above, in the solar cell module terminal box 20 according to the present embodiment, the three heat-conductive terminal plates 1A to which the output lead wires extending from the solar cell module 100 connected to the box body 20A are connected. , 1B, 1C, a plurality of unpowered cell bypass diodes 8A, 8B mounted on the terminal boards 1A, 1B and bridging between the terminal boards 1A, 1B, 1C, and potting filled in the box body 20A 4A, and the terminal plates 1A, 1B, 1C are supported by protrusions 7A, 7B, 7C standing from the bottom surface of the box body 20A so as to form gaps between the bottom surfaces. Is sealed with a potting material 4A. The terminal plate 1B has a flow hole 1e. When the potting material 4A is filled in the box body, the molten potting material 4A flows through the flow hole 1e. Since the inside of the box body 20A including the back surface of the terminal board 1B is satisfactorily surrounded and no air layer is formed, the inside of the box body 20A is appropriately cooled and the performance is improved.

Embodiment 2. FIG.
FIG. 7 is a front view of the terminal box from which the lid of the terminal box for a solar cell module according to Embodiment 2 of the present invention is removed. FIG. 8 is a cross-sectional view of a terminal board according to Embodiment 2 of the present invention. In the present embodiment, in FIG. 7, in the central terminal plate (second terminal plate) 1Ba, the large area portion 1f opposite to the lead wire connecting portion 1a is formed into a waveform as shown in FIG. The fin structure portion 1g is made to improve heat dissipation and to be compact. In the present embodiment, a through hole 1e is formed in the fin structure portion 1g formed in this waveform. Other configurations are the same as those of the first embodiment.

  Conventionally, when such a corrugated portion is provided on the terminal board, the wrapping of the potting material 4A may be deteriorated, which has been a problem. However, in this embodiment, the circulation hole 1e is provided in the fin structure portion 1g. Therefore, the potting material 4A is circulated favorably.

  As shown in FIG. 8, the shape of the fin structure portion 1g of the present embodiment is such that the center of the corrugated peak and valley portions in the height direction is approximately the height of the surface including the flat portion 1h. . In other words, with the height of the flat portion 1h as a reference, it has a wave shape that undulates in the vertical direction with the reference as a center.

  FIG. 9 is a cross-sectional view of another example terminal board 1Bb shown for comparison. The terminal board 1Bb shown in FIG. 9 has a wave shape that swells above the plane including the flat portion 1h (the center of the corrugated peak and valley portions in the height direction is higher than the plane including the flat portion 1h. Position). With such a shape, a space for accommodating the terminal board 1Bb is required to be large in the wave height direction, which is an adverse effect of miniaturization. On the other hand, the fin structure portion 1g of the present embodiment contributes to downsizing because it has a wave shape that swells up and down around the height of the surface including the flat portion 1h as described above.

  The circulation hole 1e may be drilled after the fin structure portion 1g is formed, or may be formed after the circulation hole 1e is drilled. The fin structure portion 1g of the present embodiment is formed by bending a part of the terminal plate 1Bb into a corrugated shape as described above, but plate-like fins are erected like a general fin structure. It may be done.

Embodiment 3 FIG.
FIG. 10: is a front view of the terminal board of the terminal box for solar cell modules which concerns on Embodiment 3 of this invention. 11 is a cross-sectional view taken along line AA in FIG. The three flow holes 1j formed in the large area 1f of the terminal board 1Bc of the present embodiment are produced by cutting and raising. That is, a U-shaped cut is formed in the flat plate, and the square piece inside the cut is bent and raised at one side where there is no cut. Other configurations are the same as those of the first embodiment.

  According to such a configuration, the raised square piece operates as a heat radiating fin, so that the amount of surface area that is reduced by forming a hole can be reduced. As in the above embodiment, potting is performed. It is possible to simultaneously improve the wraparound property of the material 4A and the heat dissipation.

  In the first to third embodiments, the three terminal plates 1A, 1B, and 1C and the two diodes 8A and 8B are provided, but at least two terminal plates and one diode are provided. The present embodiment can be applied to any terminal box.

  In the terminal box for a solar cell module according to the present invention, the potting material wraps well to every corner in the box body including the back surface of the terminal plate, and no air layer is formed, so that the heat dissipation performance of the diode is improved. Accordingly, the reliability of the solar cell module using the solar cell module terminal box according to the present invention is also improved. In general, solar cell modules are often installed on the roof of a house, and work such as inspection and replacement in the event of a failure requires a considerable amount of work, so the effect of improving reliability is extremely great.

  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 unpowered cell 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.

DESCRIPTION OF SYMBOLS 1A 1st terminal board 1B 2nd terminal board 1C 3rd terminal board 1a Output lead wire connection part 1b Cable connection part 1e Flow hole 1f Large area part 1g Waveform part 1h Flat part 1j Flow hole (flow hole by cutting and raising) )
4 Output part 4A Potting material (thermally conductive insulating resin)
7A, 7B, 7C Protrusion 8A, 8B Bypass diode (rectifier element)
8a Element body 8b, 8c Leg electrode 12 Solar cell 13 Support frame 14 Back cover member 15 Solar panel 16a, 16b Module connection cable (external cable)
20 Terminal box 20A Box body 20B Lid 20a Lead wire inlet 20b, 20c Cable outlet hole 100 Solar cell module

Claims (9)

A terminal box constituting the output part of the solar cell module,
A box-shaped box body fixed to the solar cell module;
A plurality of terminal plates with good thermal conductivity to which output lead wires extending from the solar cell module are connected in the box body;
An element body mounted on the terminal board, and a leg electrode extending from the element body, and a plurality of rectifying elements for unpowered cell bypass that bridges between the terminal boards at the leg electrode;
A filler filled in the box body, and the terminal plate is supported with a gap between the bottom surface of the box body and the upper and lower surfaces are sealed with the filler,
Wherein the terminal plate, when the filling material is filled in the box body, the solar cell module terminal box, wherein the passage hole filling material flows, characterized in that provided through the molten state. The solar cell module terminal box according to claim 1, wherein the terminal plate is provided with a fin structure portion that enlarges a surface area, and the flow hole is formed in the fin structure portion. The solar cell module terminal box according to claim 2, wherein at least a part of the terminal plate is formed in a corrugated shape in the fin structure portion. The plurality of terminal plates include a first terminal plate in which an external cable extending to the outside for taking out electric power is connected to the side opposite to the output lead wire, and a second terminal plate to which the external cable is not connected Including
An area of the second terminal plate opposite to the output lead wire is larger than that of the first terminal board opposite to the output lead wire to form a large area portion. It is formed in an area part. The terminal box for solar cell modules of Claim 1 characterized by the above-mentioned. The plurality of terminal plates include a first terminal plate in which an external cable extending to the outside for taking out electric power is connected to the side opposite to the output lead wire, and a second terminal plate to which the external cable is not connected Including
The side opposite to the output lead wire of the second terminal plate has a larger area than the side opposite to the output lead wire of the first terminal plate to form a large area portion, and the fin structure portion and the flow The hole is formed in the said large area part. The terminal box for solar cell modules of Claim 2 or 3 characterized by the above-mentioned. 4. The solar cell module terminal box according to claim 3, wherein the corrugation of the fin structure portion has a shape that undulates up and down around the height of the flat portion. The terminal box for a solar cell module according to any one of claims 1 to 6, wherein the distribution hole is formed by cutting and raising. The terminal box for a solar cell module according to any one of claims 1 to 7, wherein the circulation hole is formed with a plurality of small-diameter holes.   The solar cell module using the terminal box for solar cell modules of any one of Claim 1 to 8.

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