JP5048226B2 - Terminal box for solar panel - Google Patents

Description

  The present invention relates to a solar cell panel terminal box for electrically connecting a plurality of solar cell panels to each other. In particular, the present invention relates to a terminal box for a solar cell panel that can efficiently dissipate heat generated by a bypass diode incorporated in a terminal box by devising a structure of a cover plate to the surrounding atmosphere.

  Many solar cell panels are arranged on the roof of a sunny house to increase the amount of power generation. As apparent from the schematic diagram of FIG. 1, each solar cell panel P has a terminal box B attached to the back surface thereof, and the terminal boxes B of the adjacent solar cell panels P are electrically connected to each other via the external connection cable 5. Connect and use. A panel distortion preventing frame (not shown) is attached to the end of the solar cell panel P.

  The general internal structure of the terminal box B is shown in FIG. 2 with the cover plate removed. In the figure, 1 is a bottom plate, 2 is a bottom plate opening for electrodes, 3 is a side wall, 4 is a terminal plate, 5 is an external connection cable, and 6 is a bypass diode.

  The bottom plate 1 is a portion of the casing that faces the solar cell panel when the terminal box is attached to the solar cell panel. The bottom plate 1 also has a bottom plate opening 2 for electrodes, and when the bottom plate 1 is attached to the solar cell panel, the positive electrode and the negative electrode coming out of the solar cell panel are passed through the bottom plate opening 2 into the housing. It has become.

  A side wall 3 is erected on the outer periphery of the bottom plate 1 so as to surround the outer periphery of the bottom plate 1. A lid plate (not shown) is provided on the side wall at a distance from the bottom plate 1 so as to face the bottom plate 1. In addition, the bottom plate, the side wall, and the cover plate constituting the terminal box are generally made of plastic resin.

  A pair of terminal plates 4 are attached on the bottom plate 1 inside the housing, and one end of each of these terminal plates is connected to an external connection cable 5 and the other end is connected to an electrode (not shown) of the solar cell panel. Is done. Further, a bypass diode 6 is incorporated inside the housing, and the pair of terminal plates are connected to each other. In order to protect the terminal board and the bypass diode from moisture and dust, the casing is generally filled with an insulating sealing material (not shown). In addition, the number of terminal plates and bypass diodes of the solar cell panel terminal box is not limited to that shown in FIG. 2, and it is of course possible to have three or more terminal plates and two or more bypass diodes.

  The bypass diode is for short-circuiting the current due to application of the reverse voltage from one external connection cable to the other external connection cable when the electromotive force of the solar cell panel is lowered. When the bypass diode plays the above-mentioned role, since a large current flows in the forward direction of the diode, the bypass diode may generate heat violently and exceed its proper use temperature. In such a case, the diode may not function as a diode (thermal runaway), and the diode and peripheral circuits may be destroyed. Moreover, even if it is not destroyed, the life of the diode is remarkably shortened if such thermal runaway is repeated. Therefore, it is necessary to efficiently dissipate the generated heat so that the heat generated during the operation of the bypass diode does not exceed the proper operating temperature of the bypass diode.

  However, since the casing of the terminal box for a conventional solar cell panel is formed from a plastic resin having low thermal conductivity as described above, the heat dissipation efficiency from the casing to the surrounding atmosphere is not good. On the other hand, it has been proposed that the entire cover plate of the casing of the solar cell panel terminal box is made from plastic resin to metal (Patent Document 1).

Although this technology certainly has better heat dissipation efficiency than plastic resin casings, it uses a limited size of the cover plate facing the bottom plate to improve the heat dissipation efficiency from the cover plate to the surrounding atmosphere. There was a limit.
Japanese Patent Laid-Open No. 11-251614

  The present invention was devised in order to eliminate the drawbacks of the prior art, and the object thereof is a terminal box for a solar cell panel that can efficiently dissipate heat generated from a bypass diode from the housing to the surrounding atmosphere. Is to provide.

  In order to achieve the above object, the present inventor has intensively studied the preferred structure of the cover plate of the housing of the solar cell panel terminal box, and as a result, the cover plate is extended by extending outward from the side wall, thereby bypassing. It has been found that heat generated from the diode can be efficiently received by the cover plate and radiated from the housing to the surrounding atmosphere, and the present invention has been completed.

  That is, the present invention provides a terminal panel for a solar cell panel including a casing including a bottom plate, a side wall, and a cover plate, a plurality of terminal boards incorporated in the casing, and a bypass diode connecting the plurality of terminal boards to each other. The cover plate is made of a plastic resin member and extends outward from the side wall, and the plastic member is not in contact with a bypass diode. It is a terminal box. In a preferred embodiment of the solar cell panel of the present invention, the extended cover plate portion is in contact with the frame of the solar cell panel.

  Since the terminal box for solar cell panel of the present invention is enlarged by extending the cover plate outward from the side wall, the heat generated by the bypass diode can be efficiently received by the cover plate and diffused from the housing to the surrounding atmosphere. it can. In particular, when the extended cover plate comes into contact with the frame of the solar cell panel, a heat flow to the frame can also be formed, which contributes to an improvement in heat dissipation efficiency.

  Although the terminal box for solar cell panels of this invention is demonstrated concretely below, this invention is not limited to these.

  The terminal box for a solar cell panel of the present invention has a casing including a bottom plate, a side wall and a lid plate, a plurality of terminal plates incorporated in the casing, and the plurality of terminals, as in the conventional example shown in FIG. It has a structure including a bypass diode for connecting the plates to each other, but the cover plate is extended outward from the side wall, the size of the cover plate is expanded, and extended as necessary. The cover plate is in contact with the frame of the solar cell panel.

  Whereas the conventional terminal box has almost the same size as the bottom plate facing the lid plate, the terminal box of the present invention extends the lid plate outward from the side wall, and further, The main difference is that the extended cover plate portion is in contact with the frame of the solar cell panel. The terminal box of the present invention can expand the heat diffusion location and direction of the cover plate received from the bypass diode by enlarging the cover plate in this way, and also by the contact between the extended cover plate portion and the frame. It is possible to promote the release of the heat of the cover plate received from the bypass diode in the frame direction, and the heat dissipation efficiency of the bypass diode is extremely high.

  The extension expansion of the cover plate in the terminal box of the present invention may be performed in any form as long as it contributes to the expansion of the heat diffusion location or diffusion direction or the contact of the frame, and only from one side wall to the outside. It may be performed outward from a plurality or all of the side walls. Further, the extension of the cover plate is not limited to simply extending the cover plate straight, but may be bent, thickened or branched in the extended direction.

  The cover plate in the terminal box of the present invention is formed from a plastic resin member. The plastic resin member is excellent in weather resistance and insulation.

  The frame to which the extension part of the cover plate of the terminal box of the present invention is to be contacted is provided at the end of the solar cell panel as a frame for preventing distortion of the solar cell, and is generally extruded from aluminum having good thermal conductivity. It is formed from a material. In addition, the frame is generally colored black, has good heat radiation, and is extremely effective as a heat dissipation destination for heat generated during operation of the bypass diode. In the terminal box of the present invention, the heat radiation efficiency from the cover plate of the bypass diode is remarkably improved by bringing the extension part of the cover plate into contact with the frame of the solar cell panel which is an effective heat radiation destination. The contact of the extension part of the lid plate in the terminal box of the present invention with the frame includes not only direct contact between the lid plate and the frame but also indirect contact via a member having good thermal conductivity.

  Next, a structural example of the cover plate of the terminal box of the present invention will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view of the terminal box cut along a cross section passing through the bypass diode portion, and the terminal plate and the like are omitted. In the figure, 1 is a bottom plate which is a portion of a housing facing the solar cell panel when the terminal box is attached, 3 is a side wall standing so as to surround the outer periphery of the bottom plate 1, 6 is a bypass diode, and 7 is a cover plate. A plastic resin member which is a constituent member, 8 is a metal member which is a constituent member of the cover plate, 9 is a sealing material, and 10 is an air layer.

  3 to 10, the lid plate is extended and extended outward from the side wall in any of the examples. In particular, in the examples of FIGS. 8 to 10, the extended and enlarged lid plate portion serves as a heat radiation destination of the solar cell panel. Touching the frame. The terminal box of the present invention can transfer heat to the outside of the side wall and to the frame by extending and expanding the lid plate and contacting the frame in this way, thus efficiently discharging the heat generated from the bypass diode. Can be done well. In the illustrated example, the surface of the cover plate facing the inside of the housing is not in contact with the sealing material, and there is an air layer between them.

  The plastic resin member constituting the lid plate may be made of a material conventionally used for lid plates such as vinyl chloride and acrylic. The shape and dimensions of the plastic resin member constituting the cover plate are not particularly limited as long as the heat conduction efficiency is good, but larger than the bypass diode and the entire cover plate so that the heat generated from the bypass diode can be effectively dissipated to the outside. And preferably in contact with the frame.

  As a method for producing the cover plate, the plastic resin member may be formed into a desired shape by a usual method.

  The preferred examples of the solar cell panel terminal box of the present invention have been described above, but any combination, change, modification, or addition of known techniques may be included in the scope of the present invention without departing from the scope of the claims of the present invention. Belongs to. For example, the plastic resin member or metal member constituting the lid plate of the present invention can take various shapes such as a plate shape, a corrugated plate shape, a convex shape, a concave shape, and a U-shape as long as the thermal conductivity is not hindered. Also, the dimensions can be of any size as long as they are accommodated after the panel.

  According to the terminal box for a solar cell panel of the present invention, since the extension of the cover plate and the contact of the extension with the frame are made, the heat generated by the bypass diode can be released out of the housing with extremely high heat dissipation efficiency. In particular, it can be suitably used in the field of solar cell panel terminal boxes that are required to have high heat dissipation.

It is a schematic diagram which shows the back surface of a solar cell panel. It is the inside schematic diagram which removed the cover plate of the conventional terminal box. It is a schematic sectional drawing of the terminal box of this invention in which the cover board is formed only from the plastic resin member.

Explanation of symbols

P Solar cell panel B Terminal box 1 Bottom plate 2 Electrode bottom plate opening 3 Side wall 4 Terminal plate 5 External connection cable 6 Bypass diode 7 Cover plate 8 High heat conduction member 9 Sealing material 10 Air layer

Claims (2)

  In the case of a solar cell panel terminal box including a housing including a bottom plate, a side wall and a lid plate, a plurality of terminal plates incorporated in the housing, and a bypass diode connecting the plurality of terminal plates to each other. Is formed only of a plastic resin member, and is extended linearly without being bent outward from the side wall, and that an air layer exists between the plastic resin member and the bypass diode. Characteristic terminal box for solar panel.   2. The solar cell panel terminal box according to claim 1, wherein the extended cover plate portion is in contact with the frame of the solar cell panel.

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