Large-current photovoltaic junction box structure

Abstract

The invention discloses a large-current photovoltaic junction box structure, and belongs to the field of photovoltaic junction box structure design. According to the technical scheme, a main heat source heat dissipation component, namely a pin of a diode, is welded to the lower portion of tin of a copper terminal, a bus bar is welded to the tin of the copper terminal, and a large amount of heat on the pin of the diode is taken away from a box body through the bus bar; the copper terminal is provided with a bus bar through hole, so that heat at two ends of the diode can be quickly led away; the copper terminal bend is arranged on the copper terminal, so that the heat dissipation area of the copper terminal and the axial surface of the diode is increased, heat exchange is enhanced, and heat of a diode heat source is rapidly led away. A base protrusion is arranged below the base, the heat dissipation area of the copper terminal and the diode axial surface is increased, heat exchange is enhanced, heat of a diode heat source is rapidly taken away, and the structural strength of the side edge of the base is enhanced. Under the conditions of small width and small size, the heat dissipation effect of the box body can be effectively enhanced, large bypass protection current can be realized, the temperature of the junction box during bypass protection is reduced, and the service life of a product is prolonged.

Description

[0001] This invention application is a divisional application filed with the Chinese Patent Office on May 11, 2020, with application number 202010393097.2 and invention title "A High Current Photovoltaic Junction Box Structure". Technical Field

[0002] This invention belongs to the field of solar photovoltaic junction box structure design, specifically relating to a high-current photovoltaic junction box, which is characterized by its ability to carry high current. Background Technology

[0003] A solar photovoltaic (PV) junction box is a connector between a solar cell array composed of solar cell modules and a solar cell charging control device. Its main function is to connect and protect the solar PV modules, enabling the electricity generated by the solar cells to be connected to external power lines and to conduct the electrical energy generated by the solar cell modules through cables. The PV junction box and the wiring system form a sealed space. The PV junction box provides protection against environmental impacts for the wires and their connections, provides accessibility protection for live parts, and reduces the tensile stress on the connected wiring system.

[0004] Due to the specific applications and high cost of solar cells, solar photovoltaic (PV) junction boxes must be specially designed to meet the requirements of solar cell modules. One key technical indicator is the module's operating current. Operating current refers to the maximum forward current allowed to flow through a diode during continuous operation. Current flowing through a diode causes the diode's core to heat up, and exceeding the allowable temperature limit will damage the core. Therefore, the diode's rated forward operating current must not be exceeded. Current flows through the diode when the module experiences hot spot effects. Generally, a higher operating current is better, as this expands the operating range of the PV junction box. Simultaneously, to improve module power generation efficiency and reduce costs, the junction box's width and volume should be as small as possible. With technological advancements, the requirements for the current carrying capacity and miniaturization of solar PV junction boxes have become increasingly stringent, and existing PV junction box structures can no longer meet these requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a high-current photovoltaic junction box structure to solve the problem of insufficient high-current carrying capacity of current photovoltaic junction boxes mentioned in the background art.

[0006] The technical solution of the present invention is as follows:

[0007] A high-current photovoltaic junction box structure includes a box body formed by a base and a cover fastened together. The box body is provided with copper terminals, diodes, and busbars. The diodes and busbars are both soldered to the copper terminals. The copper terminals, along with the diodes and busbars, are installed together in the base. The box body is filled with potting compound to cover the diodes. The copper terminals are narrow and long. The busbars are installed on the copper terminals at the center of the copper terminals and on both sides of the diodes. The bending direction of the busbars during soldering is consistent with the length direction of the copper terminals. The diodes are installed on the copper terminals at a position biased towards one side of the copper terminals and close to one side wall of the base.

[0008] Preferably, the copper terminal includes two parts: a first terminal block and a second terminal block. The first terminal block has a first solder block on its front side, and the second terminal block has a second solder block on its front side. The diode is installed between the first terminal block and the second terminal block, and the diode is soldered to the copper terminal through the pins at both ends. The soldering area of ​​the busbar on the copper terminal and the soldering area of ​​the diode on the copper terminal are located on opposite sides of the copper terminal, respectively.

[0009] Preferably, the first terminal block and the second terminal block are respectively provided with a first busbar through hole and a second busbar through hole, the first busbar through hole and the second busbar through hole are respectively located at both ends of the diode, and the busbar passes through the first busbar through hole and the second busbar through hole respectively.

[0010] Preferably, the diode has a first pin and a second pin at its two ends; both the first pin and the second pin are bent at an angle of more than 45 degrees; the first pin is soldered to the bottom of the first solder block of the first terminal block, and the second pin is soldered to the bottom of the second solder block of the second terminal block; the two busbars are soldered to the top of the first solder block and the second solder block, respectively.

[0011] Preferably, the first terminal block and the second terminal block have a first copper terminal bend and a second copper terminal bend respectively near the axial surface of the diode, and the angles of the first copper terminal bend and the second copper terminal bend are close to the diode along the axial surface of the diode but do not contact it.

[0012] Preferably, the base has a base protrusion, the inner angle of which wraps around the diode axis, and the distance between the outer wall and the inner wall of the base protrusion remains consistent throughout.

[0013] Preferably, the outer ring of the copper terminal is bent and close to the side wall of the base.

[0014] Due to the adoption of the above technical solution, the beneficial technical effects of the present invention are as follows:

[0015] This invention relates to a high-current photovoltaic junction box, characterized by its ability to handle large currents. The invention solders the diode leads, the main heat-dissipating component, to the underside of the solder, and the busbar to the solder. The busbar removes a large amount of heat from the diode leads away from the box body. Through-holes in the busbar quickly dissipate heat from both ends of the diode. Bending the copper terminals increases the heat dissipation area between the copper terminals and the diode's axial surface, enhancing heat exchange and rapidly dissipating heat from the diode. A protruding base further increases the heat dissipation area between the copper terminals and the diode's axial surface, enhancing heat exchange and rapidly dissipating heat from the diode. Moreover, the protruding base does not increase the contact area between the base and the backplate, while simultaneously strengthening the structural strength of the base sides to prevent thermal deformation. In summary, this photovoltaic junction box effectively enhances heat dissipation while handling large currents, reducing the temperature generated during operation and significantly extending the lifespan of the photovoltaic junction box product.

[0016] The advantages of the present invention will be set forth in the following detailed description, and in some respects will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is an overall appearance view of the photovoltaic junction box of the present invention.

[0018] Figure 2 This is a diagram of the internal structure of the photovoltaic junction box of the present invention.

[0019] Figure 3 This is a front view of the copper terminals with diodes soldered on.

[0020] Figure 4 This is a back view of the copper terminals with the diode soldered on.

[0021] Figure 5 This is a diagram showing the location of the manifold perforation.

[0022] Figure 6 yes Figure 5 A cross-sectional view of AA.

[0023] The markings in the diagram are defined as follows: 1. Base, 2. Cover, 3. Wire clamp, 4. Copper terminal, 5. Diode, 6. First solder block, 7. Second solder block, 41. First terminal block, 42. Second terminal block, 51. First pin, 52. Second pin, 81. First busbar through hole, 82. Second busbar through hole, 91. First copper terminal bend, 92. Second copper terminal bend, 11. Base protrusion. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this embodiment, the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0028] Figure 1 and Figure 2 The diagram illustrates the structure of either the positive or negative terminal box in a split-type junction box. A split-type junction box decomposes the main junction box into a positive terminal box, a negative terminal box, and several intermediate terminal boxes. This minimizes connection length, disperses heat from the diode, and allows the electrical components within the intermediate terminal boxes to be pre-sealed. During on-site installation, only the positive and negative terminal boxes need to be sealed, reducing on-site work and improving wiring reliability. This embodiment uses a split-type junction box as an example; obviously, the structural design of this invention is also applicable to single-unit junction boxes. Figure 1 The image shown is an overall view of the photovoltaic junction box. Figure 2This diagram shows the internal structure of a photovoltaic junction box. (See also...) Figure 1 The photovoltaic junction box of the present invention, viewed from the outside, comprises a box body consisting of a base 1 and a cover 2 that interlock. In this embodiment, as the junction box at both ends of a split junction box, one end of the base 1 is provided with a wire clamp 3. The function of the wire clamp 3 is to allow the photovoltaic cable to pass through the middle of the wire clamp 3 and connect to the internal structure of the box body; if it is the junction box in the middle of a split junction box, this structure is not present. See also Figure 2 The internal structure of the housing includes copper terminals 4 and diodes 5. Multiple copper terminals 4 are fitted onto guide posts within the base 1 for fixation. Photovoltaic cables are threaded through the housing and soldered to the copper terminals 4. Diodes 5 are soldered to the copper terminals 4, electrically connecting the multiple copper terminals 4. The area below the diodes 5 is completely filled with potting compound. Additionally, busbars are soldered to the first solder block 6 and the second solder block 7 of the copper terminals 4. The busbars are not shown in the diagram. As can be seen from the diagram, the busbar is centered on the copper terminals 4, while the diodes 5 are positioned off-center. The function of this structure is to position the busbar in the center of the housing for better heat dissipation.

[0029] Figure 3 and Figure 4 The diode's soldering location, axial surface perimeter structure, and busbar heat dissipation method are shown. See also Figure 3 and Figure 4 The copper terminal 4 comprises two parts: a first terminal block 41 and a second terminal block 42. The first terminal block 41 has a first solder block 6 on its front side, and the second terminal block 42 has a second solder block 7 on its front side. A diode 5 is mounted between the first terminal block 41 and the second terminal block 42, electrically connecting them via its pins. The diode 5 has a first pin 51 and a second pin 52 at its two ends, both bent at 90°. The first pin 51 is resistance-welded to the underside of the first solder block 6 of the first terminal block 41, and the second pin 52 is resistance-welded to the underside of the second solder block 7 of the second terminal block 42. Two busbars are respectively welded above the first solder block 6 and the second solder block 7. The function of this structure is that the diode is a heat source, and the pins are one of the main components for heat dissipation. The diode leads are soldered to the underside of the tin, and the busbar is soldered to the tin. This ensures that the soldering area of ​​the busbar on the copper terminal and the soldering area of ​​the diode on the copper terminal are located on opposite sides of the copper terminal, facilitating the removal of a large amount of heat from the diode leads to the housing via the busbar.

[0030] Figure 5 and Figure 6 The peripheral structure of the diode is shown. See also Figure 5A first busbar through-hole 81 and a second busbar through-hole 82 are respectively provided on the first terminal block 41 and the second terminal block 42, and are located at both ends of the diode 5. The function of this structure is that the busbar passes through the first busbar through-hole 81 and the second busbar through-hole 82, thereby quickly dissipating heat from both ends of the diode. See also... Figure 6 The first terminal block 41 and the second terminal block 42 have a first copper terminal bend 91 and a second copper terminal bend 92 respectively near the diode axial surface (see reference). Figure 4 The angles of the first copper terminal bend 91 and the second copper terminal bend 92 are close to the diode along the diode's axial surface. The function of this structure is to increase the heat dissipation area between the copper terminal and the diode's axial surface, enhancing heat exchange and quickly dissipating heat from the diode's heat source. The outer rings of the first terminal block 41 and the second terminal block 42, i.e., the side closest to the housing, also have bends. The function of this structure is to increase the heat dissipation area between the copper terminal and the housing, enhancing heat exchange and quickly dissipating heat from the copper terminal. See also... Figure 6 The base 1 has an inwardly protruding base 11, the interior of which wraps around the diode's axial surface. The function of this structure is to increase the heat dissipation area between the base and the diode's axial surface, thus enhancing heat exchange. Furthermore, the distance between the outer and inner walls of the protruding base 11 remains consistent, meaning the thickness of the protruding base 11 is not altered. The function of this structure is twofold: firstly, it does not increase the contact area between the base and the backplate; secondly, it enhances the structural strength of the base's sides, preventing thermal deformation.

[0031] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A photovoltaic junction box, comprising a box body, wherein the box body is provided with copper terminals, diodes, and a busbar, wherein the diodes and the busbar are both soldered to the copper terminals; characterized in that: The copper terminal includes a first terminal block and a second terminal block. The first terminal block has a first solder block on its front side, and the second terminal block has a second solder block on its front side. The diode is installed between the first terminal block and the second terminal block. The soldering area of ​​the busbar on the copper terminal and the soldering area of ​​the diode on the copper terminal are located on opposite sides of the copper terminal, respectively. The diode has a first pin and a second pin at its two ends respectively; both the first pin and the second pin are bent at an angle of more than 45 degrees; the first pin is soldered to the bottom of the first solder block of the first terminal block, and the second pin is soldered to the bottom of the second solder block of the second terminal block; the two busbars are respectively soldered above the first solder block and the second solder block. The diode is a heat source, and the two busbars are located at both ends of the diode to dissipate the heat from both ends of the diode.

2. The photovoltaic junction box according to claim 1, characterized in that: The first terminal block and the second terminal block have a first copper terminal bend and a second copper terminal bend respectively near the axial surface of the diode. The angles of the first copper terminal bend and the second copper terminal bend are close to the diode along the axial surface of the diode but do not contact it.

3. The photovoltaic junction box according to claim 1, characterized in that: The base of the box has a base protrusion, the inner angle of which wraps around the diode axis, and the distance between the outer wall and the inner wall of the base protrusion remains consistent throughout.

4. The photovoltaic junction box according to claim 1, characterized in that: The outer ring of the copper terminal is bent and close to the base side wall of the box body.

5. The photovoltaic junction box according to claim 1, characterized in that: The copper terminal is narrow and elongated.

6. The photovoltaic junction box according to claim 1, characterized in that: The busbar is installed at the center of the copper terminal.

7. The photovoltaic junction box according to claim 1, characterized in that: The bending direction of the busbar during welding is consistent with the length direction of the copper terminal.

8. The photovoltaic junction box according to claim 1, characterized in that: The diode body is mounted on the copper terminal at a position biased towards one side of the copper terminal and close to the side wall of the base of the housing.

9. The photovoltaic junction box according to claim 1, characterized in that: The first terminal block and the second terminal block are respectively provided with a first busbar through hole and a second busbar through hole. The first busbar through hole and the second busbar through hole are respectively located at both ends of the diode, and the two busbars pass through the first busbar through hole and the second busbar through hole respectively.

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