Photovoltaic junction box

Abstract

The utility model provides a photovoltaic junction box, relates to the field of photovoltaic technology, and aims to solve the technical problem of poor heat dissipation performance of the photovoltaic junction box. The photovoltaic junction box comprises a diode, at least one heat conduction piece and a body with a cavity, wherein the diode is arranged in the cavity; the heat conduction piece comprises a hot end located in the cavity and a cold end located outside the cavity, and the hot end surrounds at least one part of the cylindrical outer surface of the diode in the circumferential direction. The heat of the photovoltaic junction box is dissipated to the external environment of the body as much as possible through the heat conduction piece, so that the overall heat dissipation performance of the photovoltaic junction box can be improved.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a photovoltaic junction box. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Photovoltaic junction boxes are an indispensable part of photovoltaic modules. They serve as both protective devices and interconnectors with the outside world, addressing safety issues related to hot spots on photovoltaic modules and the output of direct current.

[0004] In photovoltaic junction boxes of related technologies, the heat generated by the diodes and their corresponding plates is accumulated inside the junction box cavity, and cannot be dissipated to the external environment in a timely and rapid manner, which affects the working performance of the diode components and the safety of the entire circuit. Utility Model Content

[0005] The purpose of this utility model is to provide a photovoltaic junction box to solve the technical problem of poor heat dissipation performance of photovoltaic junction boxes.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] This utility model provides a photovoltaic junction box, including a diode, at least one heat-conducting component, and a body having a cavity, wherein the diode is disposed in the cavity;

[0008] The heat-conducting element includes a hot end located inside the cavity and a cold end located outside the cavity, the hot end circumferentially surrounding at least a portion of the cylindrical outer surface of the diode.

[0009] According to at least one embodiment of the present invention, the ratio of at least a portion of the cylindrical outer surface of the diode surrounded by the hot end of the heat-conducting element to the entire cylindrical outer surface of the diode is greater than or equal to 0.3.

[0010] According to at least one embodiment of the present invention, the hot end of the heat-conducting element is attached to at least a portion of the cylindrical outer surface of the diode.

[0011] According to at least one embodiment of the present invention, an insulating adhesive layer is provided between the hot end of the heat-conducting element and at least a portion of the cylindrical outer surface of the diode.

[0012] According to at least one embodiment of the present invention, the hot end of the heat-conducting element matches the shape of at least a portion of the cylindrical outer surface of the diode.

[0013] According to at least one embodiment of the present invention, the main body includes a box body and a box cover covering the box body;

[0014] The number of heat-conducting components is two, located above and below the diode respectively. The cold end of the heat-conducting component located above the diode extends through the cover to the outside of the cover, and the cold end of the heat-conducting component located below the diode extends through the bottom of the housing to the outside of the housing.

[0015] According to at least one embodiment of the present invention, the hot end of the heat-conducting element located above the diode has a half-cylindrical surface that matches at least a portion of the cylindrical outer surface of the diode, and the hot end of the heat-conducting element located below the diode has a quarter-cylindrical surface that matches at least a portion of the cylindrical outer surface of the diode.

[0016] According to at least one embodiment of the present invention, the photovoltaic junction box further includes an electrode plate electrically connected to the diode, the electrode plate being used for electrical connection to the busbar of the photovoltaic cell;

[0017] The electrode plate has a strip-shaped hole. When the busbar is connected to the electrode plate, part of the strip-shaped hole is covered by the busbar, and the other part is exposed.

[0018] According to at least one embodiment of the present invention, the box body further includes a guide tube for the passage of the busbar, the guide tube extending upward from the bottom of the box body;

[0019] The cross-sectional area of ​​the guide tube decreases along the direction away from the bottom of the box.

[0020] According to at least one embodiment of the present invention, the bottom of the box body is provided with at least one through hole; and / or,

[0021] The material of the heat-conducting component includes one of gold, silver, silver alloy, copper, copper alloy, aluminum, or aluminum alloy.

[0022] In one or more technical solutions provided in the exemplary embodiments of this utility model, at least one of the following beneficial effects can be achieved.

[0023] In the photovoltaic junction box of the exemplary embodiment of this utility model, at least a portion of the cylindrical outer surface of the diode disposed in the cavity of the main body is surrounded by the hot end of the heat-conducting element, while the cold end of the heat-conducting element penetrates through the main body and extends out of the main body to contact the external environment. Thus, through a sufficient contact area, the heat of the diode is transferred to the cold end of the heat-conducting element as much as possible, and the heat is dissipated to the external environment of the main body as much as possible through the heat-conducting element. This can improve the overall heat dissipation performance of the photovoltaic junction box, thereby improving the safety of the entire photovoltaic module or power station. Attached Figure Description

[0024] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0025] Figure 1 This is a three-dimensional exploded view of a photovoltaic junction box according to an embodiment of the present invention.

[0026] Figure 2 This is an isometric structural schematic diagram of a photovoltaic junction box (without cover and diode) according to an embodiment of the present invention;

[0027] Figure 3 This is an isometric structural diagram of the box lid according to an embodiment of the present invention;

[0028] Figure 4 This is an isometric structural schematic diagram of the box body according to an embodiment of the present utility model;

[0029] Figure 5 This is a structural schematic diagram of a heat-conducting component according to an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the structure of a heat-conducting component according to another embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of the structure of the photovoltaic junction box and the busbar after welding, according to an embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of a photovoltaic junction box for detecting poor solder joints according to an embodiment of the present invention.

[0033] Figure label:

[0034] 11. Box body; 111. Through hole; 112. Pressure block; 12. Box lid; 13. Guide tube;

[0035] 20. Thermal conductive components;

[0036] 30. Diode; 31. Electrode; 311. Slot; 311a. Notch;

[0037] 40. Pulling the pin;

[0038] 50. Busbar. Detailed Implementation

[0039] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0040] There are many types of photovoltaic junction boxes in related technologies. During the operation of photovoltaic cells, the diodes in the junction box accumulate a lot of heat inside the box, which is difficult to dissipate to the external environment and can easily lead to junction box failure.

[0041] To address the aforementioned issues, the photovoltaic junction box provided in the exemplary embodiment of this utility model uses a heat-conducting component. One end of the component is connected to the side surface of the main heat source diode, while the other end penetrates the junction box and contacts the external environment. This allows heat to dissipate outside the junction box, improving its reliability.

[0042] Figure 1 This is a three-dimensional exploded view of a photovoltaic junction box according to an embodiment of the present invention. Figure 2 This is an isometric structural schematic diagram of a photovoltaic junction box (without cover and diode) according to an embodiment of this utility model. (In conjunction with...) Figure 1 and Figure 2 As shown, the photovoltaic junction box provided by the exemplary embodiment of the present invention includes a diode 30, at least one heat-conducting element 20, and a body having a cavity. The diode 30 is disposed in the cavity. The heat-conducting element 20 includes a hot end located in the cavity and a cold end located outside the cavity. The hot end surrounds at least a portion of the cylindrical outer surface of the diode 30 in the circumferential direction.

[0043] In some embodiments, at least a portion of the cylindrical outer surface of the diode 30 surrounded by the hot end of the heat-conducting element 20 is greater than or equal to 0.3 to the entire cylindrical outer surface of the diode 30.

[0044] In practical applications, the diode 30 can be an axial diode, which is cylindrical in shape and has corresponding electrode plates 31 connected to both ends. Two busbars 50 of the photovoltaic cell, each with opposite electrodes, pass through the main body and enter the cavity, where they are welded to the two electrode plates 31. The two electrode plates 31 are fixed to the top of the posts by multiple fixing posts on the bottom of the main body, while the diode 30 is suspended within the cavity. An opening is provided on the main body to house a heat-conducting element 20. The cold end of the heat-conducting element 20 is in contact with the external environment, while the hot end is connected to the cylindrical side surface of the suspended diode 30, allowing heat from the diode 30 to dissipate to the external environment through the heat-conducting element 20. It is understood that the heat-conducting element 20 can be made of a metal with high thermal conductivity, such as gold, silver, silver alloy, copper, copper alloy, aluminum, or aluminum alloy.

[0045] In order to dissipate the heat of diode 30 as much as possible, at least a portion of the cylindrical outer surface of diode 30 surrounded by the hot end of heat-conducting element 20 is greater than or equal to the whole cylindrical outer surface of diode 30 by a ratio greater than or equal to 0.3, for example, it can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1, etc.

[0046] In some embodiments, the heat-conducting element 20 may be in direct contact with the cylindrical outer surface of the diode 30, that is, the hot end of the heat-conducting element 20 is attached to at least a portion of the cylindrical outer surface of the diode 30. In this embodiment, the edge of the heat-conducting element 20 has a sufficiently large creepage distance from the electrode plates 31 at both ends of the diode 30.

[0047] In other embodiments, the heat-conducting element 20 surrounding the cylindrical outer surface of the diode 30 may be non-contact.

[0048] For example, the heat-conducting component 20 is close to and spaced a certain distance from the diode 30. An insulating layer, such as potting compound or silicone, with strong heat dissipation capabilities, is formed between the hot end of the heat-conducting component 20 and the diode 30. The heat-conducting component 20 then surrounds the side surface of the diode 30 through the aforementioned insulating layer.

[0049] In practical applications, there is a certain gap between the end face of the heat-conducting component 20 and the cylindrical side surface of the diode 30. When the junction box is installed on the photovoltaic cell and potting compound is poured in, it will enter the gap to form an insulating layer. This insulating layer can make the heat-conducting component 20 and the diode 30 tightly connected. On the other hand, this insulating layer can also make the metal heat-conducting component 20 and the plates 31 at both ends of the diode 30 meet the electrical requirements, such as the creepage distance requirement.

[0050] In order to maximize the area of ​​the heat-conducting element 20 surrounding the outer surface of the diode 30, the end face of the hot end of the heat-conducting element 20 surrounding the cylindrical outer surface of the diode 30 is shaped to at least a portion of the cylindrical outer surface of the diode 30.

[0051] For example, the end face of the heat-conducting element 20 surrounding the hot end of the cylindrical outer surface of the diode 30 can be a half-cylindrical curved surface, and the heat-conducting element 20 can be located below the diode 30, such as... Figure 5 As shown; the end face of the hot end of the heat-conducting element 20 surrounding the cylindrical outer surface of the diode 30 can also be a quarter-cylindrical curved surface. This heat-conducting element 20 can be located above the diode 30, such as... Figure 6 As shown. Among them, Figure 5 This is a structural schematic diagram of a heat-conducting component according to an embodiment of the present invention; Figure 6 This is a structural schematic diagram of a heat-conducting component according to another embodiment of the present invention.

[0052] Figure 3This is an isometric structural diagram of the box lid according to an embodiment of the present invention. Figure 2 and Figure 3 As shown, the number of heat-conducting components 20 can be determined according to the actual heat dissipation effect and the layout of various components in the cavity.

[0053] For example, the number of heat-conducting components 20 is one, and the main body includes a housing 11 and a cover 12 covering the housing 11. The heat-conducting component 20 can be disposed above, below, or to the side of the diode. The heat-conducting component 20 can also be disposed only below the diode, with the cold end passing through an opening in the bottom of the housing 11 to contact the external environment, and the hot end of the heat-conducting component 20 surrounding the lower half of the cylindrical outer surface of the diode 30, such as... Figure 2 As shown. According to some embodiments, the hot end of the heat conductor 20 can be shaped to cover at least a portion of the lower half and / or upper half of the cylindrical outer surface of the diode 30.

[0054] It is understood that the heat-conducting element 20 may also be disposed only on the side of the diode, with the cold end passing through the opening in the side wall of the housing 11 to contact the external environment, and the hot end surrounding the cylindrical outer surface of the diode 30. In some embodiments, the heat-conducting element 20 may also be disposed only above the diode, with the cold end passing through the opening in the housing cover 12 to contact the external environment, and the hot end surrounding the upper half of the cylindrical outer surface of the diode 30, such as... Figure 3 As shown.

[0055] In some embodiments, the heat-conducting element 20 may have one or more hot ends, which may surround one or more of the upper portion, lower portion, and side portion of the diode. The heat-conducting element 20 may have one or more cold ends, which may pass through one or more of the bottom of the housing, the side wall of the housing, and the lid of the housing.

[0056] In other embodiments, there are two heat-conducting elements 20. One heat-conducting element 20 can be located below the diode, with its cold end passing through the opening at the bottom of the housing 11 to contact the external environment, and its hot end surrounding the lower part of the cylindrical outer surface of the diode. The other heat-conducting element 20 can be located below the diode, with its cold end extending through the opening of the cover 12 to contact the external environment, and its hot end surrounding the upper part of the cylindrical outer surface of the diode. Thus, heat is dissipated to the outside of the housing bottom and the outside of the cover 12 on both the upper and lower sides of the diode 30 through the heat-conducting elements 20, respectively. This embodiment can maximize heat dissipation efficiency, and the use of two heat-conducting elements 20 on the cover 12 and the bottom of the housing facilitates the assembly of the photovoltaic junction box.

[0057] In some embodiments, the hot end of the heat conductor 20 located above the diode has a half-cylindrical surface that matches at least a portion of the cylindrical outer surface of the diode, and the hot end of the heat conductor located below the diode has a quarter-cylindrical surface that matches at least a portion of the cylindrical outer surface of the diode.

[0058] Considering that after the photovoltaic junction box is installed into the photovoltaic cell, the electrode plate 31 on the diode 30 is welded to the bus bar 50 of the photovoltaic cell, the problem of poor soldering will inevitably occur during the welding process. Poor soldering will reduce the power generation of the photovoltaic power station and may even pose a fire risk.

[0059] To minimize the occurrence of the above situations, the photovoltaic junction box in the exemplary embodiment of this utility model can perform tensile testing on the busbar 50 to ensure welding reliability.

[0060] Figure 7 This is a schematic diagram of the structure of the photovoltaic junction box and the busbar after welding, according to an embodiment of the present invention. Figure 8 This is a schematic diagram of a photovoltaic junction box undergoing a cold solder joint test according to an embodiment of this utility model. (Combined with...) Figure 1 , Figure 7 and Figure 8 As shown, the faulty solder joint detection device includes two L-shaped pull pins 40. When the busbar 50 extends from the bottom of the box into the cavity and is bent and welded to the electrode 31 on the top surface of the electrode 31, one end of the pull pin 40 needs to be hooked onto the back of the busbar 50 and pulled to test whether the welding strength is achieved. Therefore, in the photovoltaic junction box provided by the exemplary embodiment of this utility model, each electrode 31 is provided with a strip-shaped hole 311. When the busbar 50 is welded to the electrode 31, part of the strip-shaped hole 311 is covered by the busbar 50, and the other part is exposed.

[0061] For example, the width of the busbar 50 is usually between 6mm and 8mm, and the length of the strip hole 311 needs to be greater than the width of the busbar 50 so as to leave a notch 311a, which can be hooked onto the back of the busbar 50 by the pull pin 40.

[0062] For example, the length of the exposed portion of the strip hole 311, that is, the length of the notch 311a, is 2mm to 5mm, such as 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, etc.

[0063] Figure 4 This is an isometric structural diagram of the box body according to an embodiment of the present invention. (In conjunction with...) Figure 4 and Figure 2As shown, the photovoltaic junction box 11 provided in the exemplary embodiment of this utility model also includes a guide tube 13 for the busbar 50 to pass through. The guide tube 13 extends upward from the bottom of the box 11. The cross-sectional area of ​​the guide tube 13 decreases along the direction away from the bottom of the box.

[0064] In practical applications, the busbar 50 extends from the bottom of the box 11 into the cavity and is welded to the electrode plate 31. In order to improve the success rate of perforation in automated production, the cross-section of the guide tube 13 gradually narrows from the bottom of the box to the electrode plate 31, that is, the cross-sectional area gradually decreases, which makes the busbar 50 easier to insert.

[0065] Considering that sealant is filled between the junction box and the photovoltaic cell during installation, air needs to be expelled from the bottom of the box during the process of pressing the photovoltaic junction box down into the sealant. Therefore, the photovoltaic junction box provided in the exemplary embodiment of this utility model has at least one through hole 111 on its bottom, for example, two through holes 111. Figure 4 As shown, this allows air to escape through the through hole 111 when the junction box is pressed down to the sealant, preventing voids in the sealant and ensuring that the photovoltaic junction box meets the wet leakage current qualification requirements.

[0066] Combination Figure 1 and Figure 4 As shown, the photovoltaic junction box also has a cable passage for cables to pass through, and a pressure block 112 is provided on the cable passage, which is embedded in the groove of the cable passage.

[0067] After the cable connecting diode 30 passes through the cable tray, the clamping block 112 can be embedded in the slot of the cable tray to form a complete wire hole. The detachable design of the cable tray and the clamping block 112 facilitates the removal of the junction box from the photovoltaic module.

[0068] Those skilled in the art should understand that the above embodiments are merely for clearly illustrating the present invention and are not intended to limit the scope of the present invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A photovoltaic junction box, characterized in that, It includes a diode, at least one heat-conducting component, and a body having a cavity, wherein the diode is disposed within the cavity; The heat-conducting element includes a hot end located inside the cavity and a cold end located outside the cavity, the hot end circumferentially surrounding at least a portion of the cylindrical outer surface of the diode.

2. The junction box according to claim 1, characterized in that, The ratio of at least a portion of the cylindrical outer surface of the diode surrounded by the hot end of the heat-conducting element to the entire cylindrical outer surface of the diode is greater than or equal to 0.

3.

3. The photovoltaic junction box according to claim 1, characterized in that, The hot end of the heat-conducting element is attached to at least a portion of the cylindrical outer surface of the diode.

4. The photovoltaic junction box according to claim 1, characterized in that, An insulating adhesive layer is provided between the hot end of the heat-conducting element and at least a portion of the cylindrical outer surface of the diode.

5. The photovoltaic junction box according to claim 1, characterized in that, The hot end of the heat-conducting element matches the shape of at least a portion of the cylindrical outer surface of the diode.

6. The photovoltaic junction box according to any one of claims 1-5, characterized in that, The main body includes a box body and a box cover covering the box body; The number of heat-conducting components is two, located above and below the diode respectively. The cold end of the heat-conducting component located above the diode extends through the cover to the outside of the cover, and the cold end of the heat-conducting component located below the diode extends through the bottom of the housing to the outside of the housing.

7. The photovoltaic junction box according to claim 6, characterized in that, The hot end of the heat-conducting element located above the diode has a half-cylindrical surface that matches at least a portion of the cylindrical outer surface of the diode, and the hot end of the heat-conducting element located below the diode has a quarter-cylindrical surface that matches at least a portion of the cylindrical outer surface of the diode.

8. The photovoltaic junction box according to claim 6, characterized in that, The photovoltaic junction box also includes an electrode plate electrically connected to the diode, the electrode plate being used for electrical connection to the busbar of the photovoltaic cell; The electrode plate has a strip-shaped hole. When the busbar is connected to the electrode plate, part of the strip-shaped hole is covered by the busbar, and the other part is exposed.

9. The photovoltaic junction box according to claim 8, characterized in that, The housing also includes a guide tube for the passage of the busbar, the guide tube extending upward from the bottom of the housing; The cross-sectional area of ​​the guide tube decreases along the direction away from the bottom of the housing.

10. The photovoltaic junction box according to claim 7, characterized in that, The bottom of the box body has at least one through hole; and / or, The material of the heat-conducting component includes one of gold, silver, silver alloy, copper, copper alloy, aluminum, or aluminum alloy.

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