Three-split junction box of solar cell

Abstract

The utility model discloses a three-split junction box of a solar cell, which comprises a cathode junction box, an intermediate junction box and an anode junction box which are arranged in sequence, the cathode junction box, the intermediate junction box and the anode junction box respectively comprise a box body, a diode module is connected inside the box body, a box cover is connected above the box body, and the anode junction box is connected with the anode junction box. One end of the negative junction box and one end of the positive junction box are connected with connecting wires, reinforcing ribs are arranged in the box body, and hollow grooves are formed in the positions, corresponding to the middles and the two sides of the reinforcing ribs, of the bottom of the box body. According to the utility model, the bottom of the box body is provided with the large-area hollow-out groove, so that the heat dissipation area is increased, the heat dissipation effect is effectively improved, and when the photovoltaic module is installed, silica gel is filled in the box body, so that the heat dissipation effect can be further ensured; according to the utility model, the upper end and the lower end of the packaging diode are both of a trapezoidal structure, so that the flowing of silica gel is accelerated during gel filling, and the situation of non-uniform heat dissipation caused by incomplete silica gel filling is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of junction box technology, specifically relating to a three-part junction box for solar cells. Background Technology

[0002] A photovoltaic junction box is a connection device between a solar cell array composed of solar cell modules and a solar charging control device. Its main functions are to connect and protect the solar photovoltaic modules, connect the power generated by the solar cells to the external line, and conduct the current generated by the photovoltaic modules.

[0003] Photovoltaic junction boxes serve two key functions in photovoltaic systems: connection and protection. The connection function is responsible for accurately transmitting the current generated by the photovoltaic modules to electrical equipment via cables and connectors. During this process, to minimize energy loss within the junction box itself, the resistance of the conductive materials and contact resistance must be extremely low. The protection function is mainly reflected in two aspects: firstly, by using bypass diodes to protect the photovoltaic modules, effectively improving their power output in the event of shading or other fault conditions; secondly, through a specially designed sealed heat dissipation system, achieving waterproof and fireproof properties. This reduces the operating temperature of the junction box and protects the photovoltaic modules, minimizing the possibility of power loss due to leakage current from the bypass diodes.

[0004] As the power output of solar modules continues to rise and conversion efficiency increases year by year, the operating current of photovoltaic systems is significantly increasing. Junction boxes, as critical connection and protection devices between solar modules, bear the heavy responsibility of power output and line protection, and therefore need to have strong current-carrying capacity. Current-carrying capacity is closely related to several indicators such as heat dissipation, conductivity, and reliability tolerance.

[0005] However, the heat dissipation of existing junction boxes can no longer meet the requirements. Therefore, there is an urgent need for a three-part junction box for solar cells with good heat dissipation performance that can pass junction temperature and thermal escape tests under high current conditions. Utility Model Content

[0006] The purpose of this invention is to provide a three-part junction box for solar cells to solve the problems mentioned in the background art. The three-part junction box for solar cells provided by this invention has good heat dissipation performance and can pass junction temperature and thermal escape tests under high current conditions.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a three-part junction box for a solar cell, comprising a negative junction box, a middle junction box, and a positive junction box arranged sequentially, wherein the negative junction box, the middle junction box, and the positive junction box each include a box body, a diode module is connected inside the box body, a box cover is connected to the top of the box body, a connecting wire is connected to one end of the negative junction box and the positive junction box, a reinforcing rib is provided inside the box body, and hollow grooves are provided at the bottom of the box body corresponding to the middle and both sides of the reinforcing rib.

[0008] To further connect the lid and the box body, the box body has fastening blocks on its two short sides, the lid has fastening grooves corresponding to the fastening blocks, and the box body also has support blocks inside.

[0009] To prevent damage to the silicone inside the box when opening the lid, a notch is provided on one side of the latch.

[0010] To prevent silicone from overflowing during potting and to protect the edges of the solar panel and the housing, the negative terminal box and the positive terminal box are further provided with overflow grooves near the connecting wires.

[0011] To secure the connecting wire to the box and ensure the tensile strength of the connecting wire, a pressure plate is further connected to the bottom of both the negative and positive terminal boxes near the connecting wire. The pressure plate has symmetrical ribs inside.

[0012] To accelerate the flow of silicone during potting and avoid uneven heat dissipation due to incomplete silicone filling, the diode module further includes a copper bracket with a packaged diode connected to it. The upper and lower ends of the packaged diode are both trapezoidal in shape.

[0013] To facilitate the routing of the busbar, additionally, lead-out slots are provided on both sides of the packaged diode on the copper support.

[0014] To position the copper bracket during installation and prevent it from shifting during welding, positioning holes are provided at the four corners of the copper bracket, and positioning posts corresponding to the positioning holes are provided inside the box.

[0015] To raise the height of the box, allowing the silicone to penetrate to the bottom and ensure a tight seal, and to prevent black leakage from the bottom, support feet are provided at the four corners of the bottom of the box.

[0016] To facilitate the application of sealant and ensure a tight seal between the box and the photovoltaic module, a sealant groove is provided along the bottom edge of the box.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. This utility model has a large area of ​​hollowed-out groove at the bottom of the box, which increases the heat dissipation area and effectively improves the heat dissipation effect. When installing with photovoltaic modules, filling the inside of the box with silicone can further ensure the heat dissipation effect.

[0019] 2. This utility model supports the diode module with reinforcing ribs, which can prevent the diode from collapsing due to stress on the solder pads during soldering. In addition, the sloping surface at the bottom of the reinforcing ribs can facilitate the passage of the busbar.

[0020] 3. The upper and lower ends of the diode packaged in this utility model are both trapezoidal in shape, which accelerates the flow of silicone during potting and avoids uneven heat dissipation caused by incomplete silicone filling.

[0021] 4. The copper bracket of this utility model adopts a large area copper sheet design, which can increase the heat dissipation speed and reduce safety hazards;

[0022] 5. The box body of this utility model is provided with a notch groove located on one side of the buckle block. Setting the notch groove on the box body can prevent damage to the silicone inside the box body when opening the box lid.

[0023] 6. The negative terminal box and the positive terminal box of this utility model are provided with an overflow groove at one end of the box near the connecting wire to prevent silicone from overflowing during glue filling and to protect the edges of the solar panel and the box body.

[0024] 7. The pressure plate of this utility model has symmetrical ribs inside to ensure the tension of the connecting wire and increase the distance of water vapor transmission, thus preventing water vapor from entering the interior of the box along the connecting wire.

[0025] 8. The four corners of the bottom of the box body of this utility model are provided with support feet to raise the height of the box body, so that the silicone can penetrate into the bottom of the box body to ensure the seal and prevent the bottom of the box body from leaking black.

[0026] 9. The bottom edge of the box body of this utility model is provided with a glue groove for applying sealant to ensure the sealing of the connection between the box body and the photovoltaic module. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of this utility model;

[0028] Figure 2 This is a schematic diagram of the negative terminal box of this utility model;

[0029] Figure 3 This is a schematic diagram of the intermediate junction box of this utility model;

[0030] Figure 4 This is a schematic diagram of the positive terminal box of this utility model;

[0031] Figure 5 This is a schematic diagram of the structure of the box body of this utility model;

[0032] Figure 6 This is a schematic diagram of the structure of the box lid of this utility model;

[0033] Figure 7 This is a schematic diagram of the front structure of the diode module of this utility model;

[0034] Figure 8 This is a schematic diagram of the back of the diode module of this utility model;

[0035] Figure 9 This is a top-view structural diagram of the diode module and housing after assembly of this utility model;

[0036] Figure 10 This is a schematic diagram of the pressure plate of this utility model.

[0037] In the diagram: 1. Negative terminal box; 2. Intermediate terminal box; 3. Positive terminal box; 4. Box body; 41. Buckle block; 42. Notch groove; 43. Reinforcing rib; 44. Hollowed-out groove; 45. Glue overflow groove; 46. Positioning post; 47. Support block; 48. Glue groove; 49. Support foot; 5. Diode module; 51. Copper bracket; 52. Encapsulated diode; 53. Positioning hole; 54. Lead-out groove; 55. Bottom solder block; 6. Box cover; 61. Buckle groove; 7. Connecting wire; 8. Wire clamping plate; 81. Raised rib; 9. Indicator block. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] Example 1

[0040] Please see Figures 1-10This utility model provides the following technical solution: a three-part junction box for a solar cell, comprising a negative junction box 1, a middle junction box 2, and a positive junction box 3 arranged sequentially. The negative junction box 1 and the positive junction box 3 are symmetrically arranged. Each of the negative junction box 1, the middle junction box 2, and the positive junction box 3 includes a box body 4. A diode module 5 is connected inside the box body 4. A box cover 6 is connected to the top of the box body 4. A connecting wire 7 is connected to one end of the negative junction box 1 and the positive junction box 3. A reinforcing rib 43 is provided inside the box body 4. The bottom of the reinforcing rib 43 has a slope. Hollow grooves 44 are provided at the middle and both sides of the bottom of the box body 4 corresponding to the reinforcing rib 43. In this embodiment, the inside of the box body 4 and the outside of the connecting wire 7 are corona treated to ensure adhesion to the silicone.

[0041] By adopting the above technical solution, the present invention provides a large area of ​​hollow groove 44 at the bottom of the box 4, which increases the heat dissipation area and effectively improves the heat dissipation effect. When installing with photovoltaic modules, silicone is filled inside the box 4 to further ensure the heat dissipation effect. The present invention supports the diode module 5 with reinforcing ribs 43, which can prevent the diode from collapsing due to the force on the solder pads during welding. In addition, the sloping surface at the bottom of the reinforcing ribs 43 can facilitate the passage of the busbar.

[0042] Specifically, the box body 4 has fastening blocks 41 on its two short sides, and the box cover 6 has fastening grooves 61 corresponding to the fastening blocks 41. The box body 4 also has a support block 47 inside, which supports the box cover 6.

[0043] By adopting the above technical solution, the connection between the lid 6 and the body 4 is achieved through the cooperation of the buckle 41 and the buckle groove 61.

[0044] Specifically, the bottom of the box 4 of the negative terminal box 1 and the positive terminal box 3, near the end of the connecting wire 7, is connected to a wire clamping plate 8.

[0045] The above technical solution is used to fix the connecting wire 7 to the box 4.

[0046] Specifically, the diode module 5 includes a copper bracket 51, on which a packaged diode 52 is connected. The upper and lower ends of the packaged diode 52 are both trapezoidal in shape.

[0047] By adopting the above technical solution, the flow of silicone is accelerated during the potting process, avoiding uneven heat dissipation caused by incomplete silicone filling.

[0048] In this utility model, the copper bracket 51 adopts a large-area copper sheet design, which can increase the heat dissipation speed and reduce safety hazards.

[0049] Specifically, lead-out slots 54 are provided on both sides of the packaged diode 52 on the copper bracket 51.

[0050] The above technical solution is used to draw out the busbar.

[0051] Example 2

[0052] The difference between this embodiment and embodiment 1 is that, specifically, the box body 4 is provided with a notch 42 located on one side of the buckle 41.

[0053] By adopting the above technical solution and setting the notch 42 on the box body 4, the silicone inside the box body 4 can be prevented from being damaged when the box cover 6 is opened.

[0054] Example 3

[0055] The difference between this embodiment and embodiment 1 is that, specifically, an overflow groove 45 is provided inside the box 4 of the negative terminal box 1 and the positive terminal box 3 near the end of the connecting wire 7.

[0056] By adopting the above technical solution, silicone overflow during potting is prevented, thus protecting the edges of the solar panel and the housing 4.

[0057] Example 4

[0058] The difference between this embodiment and embodiment 1 is that, specifically, the inside of the pressure plate 8 is provided with symmetrical ribs 81.

[0059] By adopting the above technical solution, the tensile strength of the connecting wire 7 is guaranteed, and the distance for moisture transmission is increased, preventing moisture from entering the interior of the box 4 along the connecting wire 7. In addition, the wire pressing plate 8 is ultrasonically pressed to further guarantee the tensile strength of the connecting wire 7.

[0060] Example 5

[0061] The difference between this embodiment and embodiment 1 is that: specifically, the four corners of the copper bracket 51 are provided with positioning holes 53, and the inside of the box body 4 is provided with positioning posts 46 corresponding to the positioning holes 53.

[0062] By adopting the above technical solution, the installation of the copper bracket 51 can be positioned, and the offset of the copper bracket 51 during welding can be avoided.

[0063] In addition, the upper ends of the two positioning posts 46 on one side are provided with circular pins, and the upper ends of the two positioning posts 46 on the other side are provided with rectangular pins, and the shape of the positioning hole 53 corresponds to them.

[0064] The above technical solution is used to limit the installation direction of the copper bracket 51 and prevent the direction from being reversed.

[0065] Example 6

[0066] The difference between this embodiment and embodiment 1 is that, specifically, the four corners at the bottom of the box 4 are provided with support feet 49.

[0067] By adopting the above technical solution, the height of the box body 4 is increased, allowing the silicone to penetrate to the bottom of the box body 4, ensuring sealing, and preventing black leakage from the bottom of the box body 4.

[0068] Example 7

[0069] The difference between this embodiment and embodiment 1 is that, specifically, a glue groove 48 is provided on the edge of the bottom of the box 4.

[0070] By adopting the above technical solution, sealant is applied to ensure the airtightness of the connection between the box 4 and the photovoltaic module.

[0071] Example 8

[0072] The difference between this embodiment and embodiment 1 is that, specifically, one end of the box body 4 of the intermediate junction box 2 is connected to an indicator block 9.

[0073] The above technical solution is used to distinguish between positive and negative terminals and avoid reverse connection of the intermediate junction box 2.

[0074] Example 9

[0075] The difference between this embodiment and embodiment 1 is that, specifically, the copper support 51 has bottom solder blocks 55 on both sides of the packaged diode 52.

[0076] By adopting the above technical solution, it can be used in resistance welding. If laser welding is used, the bottom solder block 55 is not required.

[0077] Example 10

[0078] The difference between this embodiment and embodiment 1 is that, specifically, the bottom of the box 4 is provided with a dense dotted structure.

[0079] By adopting the above technical solution, the bonding performance between the box 4 and the photovoltaic module is increased.

[0080] In summary, this invention features a large-area hollowed-out groove 44 at the bottom of the housing 4, increasing the heat dissipation area and effectively improving heat dissipation. When installed with photovoltaic modules, filling the interior of the housing 4 with silicone further ensures heat dissipation. The reinforcing ribs 43 support the diode module 5, preventing the diode from collapsing due to stress on the solder pads during soldering. Additionally, the sloping bottom of the reinforcing ribs 43 facilitates the passage of the busbar. The upper and lower ends of the encapsulated diode 52 are trapezoidal, accelerating silicone flow during potting and preventing uneven heat dissipation due to incomplete silicone filling. The copper bracket 51 uses a large-area copper sheet design, increasing heat dissipation speed and reducing safety hazards. The housing 4 has a notch 42 located on one side of the latch block 41. On the box body 4, the silicone inside the box body 4 can be prevented from being damaged when the box cover 6 is opened; the negative terminal junction box 1 and the positive terminal junction box 3 of this utility model have an overflow groove 45 near the connecting wire 7 inside the box body 4 to prevent silicone from overflowing during glue filling and to protect the edges of the solar panel and the box body 4; the inside of the pressure plate 8 of this utility model has symmetrical ribs 81 to ensure the tension of the connecting wire 7, and at the same time to increase the distance of water vapor transmission, preventing water vapor from entering the inside of the box body 4 along the connecting wire 7; the four corners of the bottom of the box body 4 of this utility model are respectively provided with support feet 49 to raise the height of the box body 4, so that the silicone can penetrate to the bottom of the box body 4 to ensure the seal and prevent black leakage from the bottom of the box body 4; the bottom edge of the box body 4 of this utility model has a glue groove 48 for applying sealant to ensure the seal between the box body 4 and the photovoltaic module.

[0081] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A three-part junction box for a solar cell, characterized in that: It includes a negative terminal box, an intermediate terminal box, and a positive terminal box arranged in sequence. Each of the negative terminal box, intermediate terminal box, and positive terminal box includes a box body. A diode module is connected inside the box body. A box cover is connected to the top of the box body. A connecting wire is connected to one end of the negative terminal box and the positive terminal box. The box body is provided with reinforcing ribs inside. The bottom of the box body is provided with hollow grooves in the middle and on both sides corresponding to the reinforcing ribs.

2. The three-part junction box for a solar cell according to claim 1, characterized in that: The box body has fastening blocks on its two short sides, and the box lid has fastening grooves corresponding to the fastening blocks. The box body also has support blocks inside.

3. The three-part junction box for a solar cell according to claim 2, characterized in that: The box body is provided with a notch or groove located on one side of the buckle.

4. The three-part junction box for a solar cell according to claim 1, characterized in that: The negative terminal box and the positive terminal box are provided with an overflow groove near the connecting wire inside the box.

5. A three-part junction box for a solar cell according to claim 1, characterized in that: The bottom of the negative terminal box and the positive terminal box are connected to a pressure plate near the connecting wire, and the pressure plate has symmetrical ribs inside.

6. A three-part junction box for a solar cell according to claim 1, characterized in that: The diode module includes a copper support, on which a packaged diode is connected. The upper and lower ends of the packaged diode are both trapezoidal in shape.

7. A three-part junction box for a solar cell according to claim 6, characterized in that: The copper support has lead-out slots on both sides of the packaged diode.

8. A three-part junction box for a solar cell according to claim 6, characterized in that: The copper bracket has positioning holes at its four corners, and the box has positioning posts inside that correspond to the positioning holes.

9. A three-part junction box for a solar cell according to claim 1, characterized in that: The box is equipped with four support legs at the four corners of its bottom.

10. A three-part junction box for a solar cell according to claim 1, characterized in that: The bottom edge of the box is provided with a glue groove.

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