JP2017085764A - Terminal box for solar battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal box for a solar battery that enables easy exchange of a bypass diode.SOLUTION: A terminal box 5 for a solar battery comprises: a plurality of terminal plates 24 connected with a plurality of electrodes 8 of a solar battery module 1; external connection cables 6a and 6b for extracting generated power to the exterior; and a plurality of bypass diodes 20 for preventing counter flow between the plurality of terminal plates 24. In the terminal box 5, the plurality of bypass diodes 20 comprise a pair of connection parts 21 connected with a pair of the terminal plates 24 corresponding to each bypass diode 20, and are formed in an integral diode unit 23 in which respective adjacent sets of bypass diodes 20 are coupled in series to each other. The terminal plate 24 is electrically connected with the corresponding connection part 21, and comprises a holding part 25 for fixing the diode unit 23.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a solar cell terminal box (junction box) for connecting an electrode of a solar power generation module (solar cell module) and taking out power, and in particular, a junction box in which a bypass diode built in the junction box can be easily replaced. And a mounting structure of the bypass diode.

  Conventionally, a photovoltaic power generation system that generates power using solar energy has been widely spread. In this solar power generation system, a plurality of solar cell modules are installed side by side on a mounting base provided in an array, the solar cell modules are connected in series, and the generated DC power is converted into AC power by a power converter. It is comprised so that it may convert and to supply electric power.

  A general solar cell module includes a module body having a plurality of solar cells that generate sunlight and generate power, a frame frame provided around the module body, and a junction box attached to the back of the module body. And an external connection cable extending from a junction box for taking out the generated power to the outside.

  In the module body, a plurality of solar cells are connected in series to form one cluster, and the plurality of clusters are connected in series via a plurality of terminal plates provided inside the junction box. External connection cables are respectively connected to terminal plates located at both ends of a plurality of clusters connected in series, that is, a pair of electrodes of the module body.

  The junction box is for taking out generated power to the outside and electrically protecting the solar cell module. For example, Patent Documents 1 and 2 disclose a junction box including a plurality of bypass diodes connected in parallel to a plurality of clusters between a pair of external connection cables. This junction box has a bypass diode corresponding to a cluster including a solar cell in which power generation is stopped when power generation is stopped in some solar cells for reasons such as foreign matter being placed on the light receiving surface of the solar cell module. It is comprised so that the electric current from clusters other than the said cluster and another solar cell module may be bypassed. Solar cells that have stopped generating power are resistors, and when the current flows, the temperature rises due to Joule heat. By bypassing the current, the solar cells that have been stopped are prevented from being damaged or fired due to overheating of the solar cells. Is bypassed so that the cluster does not affect the power generation of other clusters.

JP 2002-359389 A JP 2005-310888 A

  By the way, since the solar cell module is installed outdoors, an excessive current may temporarily flow due to a lightning strike or the like, and the bypass diode may break down. In addition, the solar cell module is repeatedly subjected to the expansion and contraction stress caused by the temperature cycle of day and night, and the connection failure of the electrode connection part between the solar battery cells may occur, corresponding to the cluster in which the connection failure has occurred. If a current continues to flow through the bypass diode for a long period of time, the bypass diode may fail. If the failed bypass diode is left unattended, the above-described solar cell module may be damaged or fired, so it is necessary to replace the failed bypass diode.

  However, the inside of the current junction box is potted with resin to prevent corrosion due to the ingress of moisture, and it is difficult to remove and replace only the damaged diode. Moreover, when replacing | exchanging the junction box whole, since the junction box is adhere | attached on the back surface of the solar cell module, there exists a possibility that a solar cell module may be damaged and damaged when cut | disconnecting an adhesion part. When the entire solar cell module is replaced, the replacement cost becomes high.

  In addition, in the junction box of Citation Example 1, it is necessary to visually confirm the terminal plate to be connected when replacing the bypass diode, and in the junction box of Citation Example 2, the electrode of the bypass diode and the terminal plate are fixed with screws. In some cases, it is difficult to replace the bypass diode because the solar cell module is installed on the roof or the wall surface and a sufficient space cannot be secured on the back side of the solar cell module.

  The objective of this invention is providing the terminal box (junction box) for solar cells which can replace | exchange a bypass diode easily.

  The terminal box for a solar cell according to claim 1 prevents a backflow between the plurality of terminal plates connected to the electrodes of the solar cell module, an external connection cable for taking out the generated power to the outside, and the plurality of terminal plates. In the solar cell terminal box provided with a plurality of bypass diodes, the plurality of bypass diodes includes a pair of connection portions to which each bypass diode is connected to a corresponding pair of terminal plates, and Each adjacent pair of bypass diodes is formed as an integral diode unit connected in series, and the terminal plate is electrically connected to a corresponding connection part and has a clamping part for fixing the diode unit. It is characterized by having.

  The terminal box for solar cell according to claim 2 is characterized in that in claim 1, when the diode unit is connected to the terminal plate, it is connected by sliding in the longitudinal direction of the diode unit. .

  According to a third aspect of the present invention, there is provided the terminal box for solar cell according to the first or second aspect, wherein an opening for passing the diode unit is provided on a side surface of the main body of the terminal box.

  According to the first aspect of the present invention, each bypass diode connecting portion of an integral diode unit in which a plurality of bypass diodes are connected in series is connected to the corresponding terminal plate via the clamping portion, and the clamping portion. Therefore, the plurality of diodes can be easily attached at one time.

  According to the invention of claim 2, since the diode unit is formed so as to be slidable in the longitudinal direction, the diode unit can be easily replaced by sliding the original diode unit so as to be pushed out by the new diode unit. it can.

  According to invention of Claim 3, since the opening part which penetrates a diode unit was provided in the side surface of the terminal box for solar cells, it is not necessary to open the lid | cover of the terminal box for solar cells, and a diode unit is exchanged easily. be able to.

It is a front view of a solar cell module. It is a rear view of a solar cell module. It is principal part sectional drawing which shows the laminated structure of a solar cell module. It is a perspective view which shows the terminal box for solar cells of this invention. It is a perspective view which shows the terminal board accommodated in the terminal box for solar cells of this invention. It is a perspective view which shows another form of a terminal board. It is a perspective view which shows the diode unit accommodated in the terminal box for solar cells of this invention. It is the equivalent circuit schematic of the solar cell module which concerns on the Example of this invention.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

First, the overall configuration of the solar cell module will be briefly described.
As shown in FIGS. 1 and 2, the solar cell module 1 includes a rectangular module main body 2 that generates power, a metal frame 3 that surrounds and protects the entire periphery of the module main body 2, and the module main body 2. The junction box 5 is attached to the rear side of the cable, and the external connection cables 6a and 6b extend from the junction box 5.

Next, the module main body 2 will be described.
As shown in FIG. 3, the module body 2 includes a protective glass 11, a synthetic resin layer 12, a power generation layer 13 including a plurality of solar cells 4, a synthetic resin layer 14, and a back protective sheet in order from the light receiving surface side. The back protective layer 15 made of is laminated. As shown in FIG. 1, the power generation layer 13 is configured by arranging a plurality of flat solar cells 4 and connecting the solar cells 4 in series with strip-shaped conductors.

Next, the junction box 5 of the present invention will be described.
As shown in FIGS. 2 and 4, the junction box 5 is formed in a box shape with resin so as to take out the electric power generated by the module body 2 to the outside and to accommodate elements for electrically protecting the module body 2. The bottom surface side is attached to the back surface of the module body 2.

  As shown in FIG. 4, inside the junction box 5, for example, four terminal boards 24 (24a to 24d) arranged in a row so that three clusters 7 (7a to 7c) are connected in series, and A pair of external connection cables 6a and 6b respectively connected to the terminal plates 24a and 24d in order to take out the electric power generated in the clusters 7a to 7c, and a bypass function for bypassing the corresponding cluster 7 (7a to 7c) A diode unit 23 or the like having a reverse current prevention function is provided. The upper end of the junction box 5 is covered and sealed with a lid member (not shown) so that foreign matter cannot enter inside.

  Openings 5a and 5b are provided on the side surfaces of the junction box 5 at positions corresponding to both ends of the diode unit 23, and the end portions of the spacers 22a and 22b provided at both ends of the diode unit 23 are the openings 5a and 5b. Are loosely fitted. An adhesive tape may be affixed to the openings 5a and 5b so as to prevent entry of foreign matter from the gaps with the spacers 22a and 22b, and a lid member may be provided.

  As shown in FIGS. 4 and 5, the terminal plate 24 has a pair of engaging claws 27 provided on the inner bottom surface of the junction box 5 in a pair of rectangular engaging holes 26 formed in the terminal plate 24. It is inserted and fixed. The terminal board 24 may be fixed to the bottom surface of the junction box 5 with screws, rivets or the like.

  As shown in FIG. 4, an electrode 8 extending from each cluster 7 is introduced into the junction box 5 from an opening 5 c provided on the bottom surface of the junction box 5. The terminal plates 24 are insulated from each other, and the clusters 7 are connected in series via the terminal plates 24. For example, a pair of electrodes 8a and 8b of cluster 7a are connected to terminal plates 24a and 24b, respectively, a pair of electrodes 8c and 8d of cluster 7b are connected to terminal plates 24b and 24c, respectively, and a pair of clusters 7c Electrodes 8e and 8f are connected to terminal plates 24c and 24d, respectively. External connection cables 6a and 6b connected to the terminal plates 24a and 24d located at both ends respectively extend from the side surface of the junction box 5 to the outside.

  As shown in FIG. 5, the terminal plate 24 is cut and bent so that a part of a rectangular metal plate is opposed to each other to form a sandwiching portion 25. The clamping part 25 has an elastic force in the opposing direction so that the opposing metal plates can easily pass the diode unit 23 therebetween, and the clamping part 25 cannot be moved easily in the extending direction of the clamping part. It is bent in a bulging shape toward the outside. As shown in FIG. 6, a clamping portion 25 formed by being bent so that rectangular metal plates face each other may be fixed to the terminal plate 24 by screws, rivets, brazing, welding, or the like.

  As shown in FIG. 7, a plurality of columnar or prismatic bypass diodes 20 having electrodes, which are connection portions 21 connected to the terminal plate 24, are formed on a conductive connecting member, for example, a conductive adhesive. A pair of spacers 22a and 22b, which are insulators having the same thickness as that of the bypass diode 20, are connected to each other at both ends, thereby forming an integrated diode unit 20 in series. The diode unit 23 is formed by the pair of spacers 22a and 22b so as to have the same length as the width of the junction box 5 in the direction in which the diode unit 23 is mounted. The outer peripheral surface of the diode unit 23 is formed so that the clamping part 25 can slide smoothly.

  As shown in FIG. 4, the connecting portion 21 of the diode unit 23 can be sandwiched and fixed by the elastic force of the sandwiching portion 25, and the connecting portion 21 that is the electrode of the bypass diode 20 and the terminal plate 24 are interposed via the sandwiching portion 25. Are electrically connected. For example, in the bypass diode 20a corresponding to the cluster 7a, the connection portions 21a and 21b of the diode unit 23 are connected to the sandwiching portions 25a and 25b of the terminal plates 7a and 7b, respectively, and the bypass diode 20b corresponding to the cluster 7b is connected to the connection portion 21b. , 21c are connected to the clamping portions 25b, 25c of the terminal plates 7b, 7c, respectively, and the bypass diode 20c corresponding to the cluster 7c is connected to the clamping portions 25c, 25d of the terminal plates 7c, 7d, respectively. .

Next, an equivalent circuit of the solar cell module 1 will be described.
As shown in FIG. 8, the module body 2 of the solar cell module 1 includes, for example, 16 solar cells 4 connected in series to form one cluster 7, and three clusters 7 (7 a to 7 c) in series. One module main body 2 is formed by 48 solar cells 4 connected to. A corresponding bypass diode 20 is connected in parallel to one cluster 7. For example, corresponding bypass diodes 20a, 20b, and 20c are connected in parallel to the clusters 7a, 7b, and 7c. A pair of external connection cables 6a and 6b connected to both ends of the solar cells 4 connected in series are connected to the power conversion device via the adjacent solar cell module 1 or connection box, etc., although not shown. The DC power generated by the main body 2 is converted into AC power and fed.

Next, the operation and effect of the solar cell terminal box 5 of the present invention will be described.
The solar cells 4 connected in series in the module main body 2 receive sunlight to generate power, and the generated power is supplied to the outside through the external connection cables 6a and 6b. Here, when power generation is stopped in some of the solar cells 4, current from other clusters 7 flows to the bypass diode 20 corresponding to the cluster 7 including the solar cells 4, thereby reducing the influence of the power generation stop. . For example, even if power generation is stopped in the cluster 7a among the clusters 7a, 7b, and 7c, a current flows through the bypass diode 20a that bypasses the cluster 7a. it can.

  In addition, if the bypass diode 20 fails, leaving it alone may cause damage to the solar cell module 1 or a fire, so the bypass diode 20 is replaced. The diode unit 23 attached to the junction box 5 is formed by integrally forming a plurality of bypass diodes 20 in series, and the terminal board 24 includes a clamping part 25 corresponding to the connection part 21 of the diode unit 23. The diode unit 23 can be easily mounted, and the plurality of diodes 20 can be replaced at a time.

  Further, the diode unit 23 is formed so as to be slidable between the sandwiching portions 25, and can be slid in the longitudinal direction to a position where the connection portion 21 and the sandwiching portion 25 are connected. Mounting can be performed easily. Even when the diode unit 23 is replaced, by sliding the tip of the new diode unit 23 against the one end of the original diode unit 23 in the longitudinal direction, the original diode unit 23 can be removed and the new diode unit 23 can be removed. Since the mounting can be performed at the same time, the diode unit 23 can be easily replaced.

  Furthermore, since the openings 5a and 5b through which the diode unit 23 can be inserted are provided on the side surface of the junction box 5, for example, a new diode unit 23 is inserted from the opening 5a while the original diode unit 23 is opposed to the original position. It is possible to replace the diode unit 23 by removing it from the provided opening 5b, and it is not necessary to open the lid member of the junction box 5, and the diode unit 23 can be easily replaced.

  In addition, since the length of the diode unit 23 is formed to be the same as the width of the junction box 5, the diode unit 23 is attached so as not to protrude from the openings 5 a and 5 b, thereby connecting to the terminal plate 24. The diode unit 23 can be mounted at the position to be mounted, and the mounting position of the diode unit 23 can be easily determined.

An example in which the embodiment is partially changed will be described.
[1] The diode unit 23 may connect each bypass diode with an insulating connecting member. In this case, the clamping part 25 may be formed so as to be connected to the connection parts 21 on both sides of the insulating connecting member, and two clamping parts 25 are formed on one terminal plate 24 so as to be connected to each other. Also good.
[2] The spacers 22a and 22b may be gradually narrowed toward the tip.
[3] The diode unit 23 is mounted on a flat substrate so that a plurality of bypass diodes 20 are connected in series, and a connection portion 21 corresponding to an electrode of each bypass diode 20 is formed, and a corresponding terminal plate It may be connected to 24 clamping parts 25.
[4] A guide portion for guiding the sliding movement of the diode unit 23 may be provided between the openings 5 a and 5 b of the junction box 5 and the clamping portion 25.
[5] The inside of the junction box 5 may be potted with resin so that the clamping part 25 is exposed from the resin.
[6] In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. It is.

1 Photovoltaic module (solar cell module)
2 Module body 3 Frame frame 4 Solar cell 5 Junction box (terminal box for solar cell)
6a, 6b External connection cable 7, 7a-7c Cluster 8, 8a-8f Electrode 11 Protective glass 12 Synthetic resin layer 13 Power generation layer 14 Synthetic resin layer 15 Back surface protective layer 20, 20a-20c Bypass diodes 21, 21a-21d Connection part 22, 22a, 22b Spacer 23 Diode unit 24, 24a-24d Terminal plate 25, 25a-25d Holding part 26 Engaging hole 27 Engaging claw

Claims (3)

Provided with a plurality of terminal plates connected to a plurality of electrodes of the solar cell module, an external connection cable for taking out generated power to the outside, and a plurality of bypass diodes for preventing backflow between the plurality of terminal plates Solar cell terminal box
The plurality of bypass diodes include a pair of connection portions connected to the pair of terminal plates to which the bypass diodes correspond, and the adjacent bypass diodes of each pair are connected in series. Formed in the diode unit,
The said terminal board is provided with the clamping part which fixes the said diode unit while electrically connecting with a corresponding connection part, The terminal box for solar cells characterized by the above-mentioned.   2. The solar cell terminal box according to claim 1, wherein when the diode unit is connected to the terminal plate, the diode unit is connected by sliding in the longitudinal direction of the diode unit.   The solar cell terminal box according to claim 1 or 2, wherein an opening for passing the diode unit is provided on a side surface of the main body of the terminal box.