Photovoltaic intelligent junction box

Abstract

The utility model provides a photovoltaic intelligent junction box, which is characterized in that a shell is a strip-shaped shell, a circuit board is arranged in the shell, the circuit board is connected with one end of each photovoltaic cable, each photovoltaic cable is led out from the end part of the shell, the other end of each photovoltaic cable is provided with a photovoltaic connector, and two photovoltaic cables are respectively led out from two ends of the shell; the circuit board is provided with a welding terminal for connecting a photovoltaic cable, a bypass protection MOSFET bypass switch and a control circuit, the welding terminal adopts a flat design, and the bypass protection MOSFET bypass switch is electrically isolated from the control circuit; two bus bar through holes are formed in the circuit board, the MOSFET bypass switch is arranged in the middle of the two bus bar through holes, and the photovoltaic bus bars are welded to the bus bar bonding pads through the bus bar through holes. According to the utility model, the power loss is reduced, the current mismatch is relieved, the material cost is saved, the production time is saved, and the fixing stability and tensile resistance of the photovoltaic cable are improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of junction box, especially relates to a photovoltaic intelligent junction box. BACKGROUND

[0002] The photovoltaic junction box, as the name implies, is a wiring device used to connect photovoltaic modules and external circuits. It is usually installed on the back of the photovoltaic module and consists of high-strength plastic, bypass diodes, photovoltaic cables, photovoltaic connectors, and other parts. As an important part of photovoltaic modules, the photovoltaic junction box plays an important role in photovoltaic modules. First, the photovoltaic junction box connects the photovoltaic module with external loads or other photovoltaic modules. Second, the photovoltaic junction box contains bypass diodes, which provide a bypass protection path when the photovoltaic module is partially shaded or fails, preventing hot spot effects and protecting the photovoltaic module from damage. Finally, the dust and water-proof function ensures stable operation in various environments, and the photovoltaic junction box has good sealing performance to prevent water, dust, and other impurities from entering the photovoltaic module.

[0003] With the continuous progress of science and technology, photovoltaic power generation systems are also constantly upgrading and innovating. Based on traditional photovoltaic junction boxes, photovoltaic intelligent junction boxes have emerged as the times require and have become the new darling of modern photovoltaic systems. It not only inherits the basic functions of traditional junction boxes, but also integrates intelligent technology, providing more protection for the efficient and safe operation of photovoltaic systems. Photovoltaic intelligent junction boxes integrate intelligent monitoring, rapid and safe shutdown, maximum power point tracking, arc detection, and other management functions based on traditional junction boxes.

[0004] However, with the adjustment of photovoltaic module technology, the traditional integrated photovoltaic junction box structure on conventional photovoltaic modules is split into a split structure, corresponding to the battery string inside the photovoltaic module, to achieve better heat dissipation to meet the greater output current of the photovoltaic module. However, the photovoltaic intelligent junction box cannot adapt to the split structure design due to circuit arrangement and other factors. The photovoltaic intelligent junction box usually needs to make major changes to the original circuit arrangement of the photovoltaic module to meet the normal operation of the intelligent junction box, which increases the difficulty of photovoltaic module production. In the current photovoltaic module production, which uses automated equipment, changing the circuit arrangement of the photovoltaic module is costly. Minimizing changes to the circuit of the photovoltaic module is a key consideration in the design of the photovoltaic intelligent junction box.

[0005] In addition, the existing photovoltaic intelligent junction box also faces the following problems:

[0006] 1. The photovoltaic smart junction box must meet the operating current of the photovoltaic modules, which is close to 20A (amperes), resulting in significant power loss and severe heat generation. Typically, the ambient temperature during operation of the photovoltaic junction box is very high, requiring stable operation at 85℃. High operating temperatures will shorten the lifespan of the electronic components in the smart junction box and may even cause them to fail or be damaged. Therefore, to ensure long-term stable operation, the photovoltaic smart junction box requires very high standards for power consumption and heat dissipation capabilities.

[0007] 2. Damage to the photovoltaic smart junction box will cause the entire photovoltaic module to malfunction, resulting in significant losses. Even if the smart circuit part is replaced by plugging and unplugging the circuit board, there is still a risk of fire caused by aging of the metal parts in the plugged-in area leading to high contact resistance. Therefore, the maintainability of photovoltaic modules using smart junction boxes is also a key consideration to reduce property damage caused by damage to the smart junction box.

[0008] 3. When the temperature rises, the open-circuit voltage (Voc) of the photovoltaic module drops significantly. Although the short-circuit current (Isc) increases slightly, the overall power output (Pmax) decreases noticeably. Therefore, accurately understanding the operating temperature of the photovoltaic module is very helpful for analyzing its power generation and for promptly identifying temperature anomalies caused by hot spots or fires. However, current photovoltaic smart junction boxes mostly collect temperatures from the internal circuit boards, resulting in significant discrepancies between the collected temperature data and the actual photovoltaic module temperature.

[0009] 4. Typically, photovoltaic smart junction boxes need to be designed to be large in size to meet multiple intelligent functions and the aforementioned heat resistance and heat dissipation capabilities, which is detrimental to cost control. For photovoltaic smart junction boxes used in double-glass photovoltaic modules, a large size will cause shading of the cells on the back of the photovoltaic module, resulting in current mismatch and reduced power generation.

[0010] 5. Because conventional smart junction boxes contain integrated circuits that adjust voltage and current values, these integrated circuits will adjust the above parameter values ​​during routine electrical performance testing of photovoltaic modules, making it impossible to obtain accurate electrical performance parameters of photovoltaic modules. Utility Model Content

[0011] To address the above problems, this utility model provides a photovoltaic smart junction box.

[0012] The photovoltaic intelligent junction box provided by this utility model includes: a shell, a cover, a circuit board, four photovoltaic cables, a cable clamp, and a photovoltaic connector.

[0013] in,

[0014] The shell is a long strip-shaped shell, which is internally provided with the circuit board fixedly connected with one end of each of the photovoltaic cables, and the cable pressing block is used for fixing each of the photovoltaic cables to the circuit board; each of the photovoltaic cables is led out from the end of the shell, and the other end of each of the photovoltaic cables is provided with the photovoltaic connector; two photovoltaic cables are led out from each of the two ends of the shell respectively.

[0015] The circuit board is provided with a welding terminal for connecting the photovoltaic cable, a bypass protection MOSFET bypass switch and a control circuit, the welding terminal adopts a flattened design, i.e. a flat structure, and the bypass protection MOSFET bypass switch is electrically isolated from the control circuit.

[0016] The circuit board is provided with two bus bar perforations, the MOSFET bypass switch is arranged at the middle position of the two bus bar perforations, and the photovoltaic bus bar is welded to the bus bar pad on the circuit board through the bus bar perforation.

[0017] Further,

[0018] Each of the photovoltaic cables is an input end of the photovoltaic intelligent junction box, and the photovoltaic intelligent junction box is connected with the cell string in the photovoltaic module through bus bar welding.

[0019] Further,

[0020] The input end of the photovoltaic intelligent junction box is connected with the negative box body and the positive box body of the conventional split-type junction box through the photovoltaic cable and the photovoltaic connector.

[0021] Further,

[0022] The MOSFET in the bypass protection MOSFET bypass switch is a wide band gap semiconductor material MOSFET.

[0023] Further,

[0024] The box cover is used for sealing the shell and is made of aluminum alloy.

[0025] Further,

[0026] The box cover extends into the interior of the shell and is provided with a plurality of heat dissipation columns, the end of the plurality of heat dissipation columns is opposite to the surface of the heating component on the circuit board and the welding terminal, and the gap between the plurality of heat dissipation columns and the heating component and the welding terminal is filled with a heat-conducting gasket.

[0027] Further,

[0028] The box cover is treated by an anodization process, and an oxide layer is added to the surface.

[0029] Further,

[0030] The entire cavity of the photovoltaic intelligent junction box is sealed by using a pouring sealant with a viscosity less than 3000 mPa.s and a thermal conductivity greater than 1 W / (m.K).

[0031] Further,

[0032] The temperature sensor is further arranged adjacent to the bus bar pad to collect the temperature of the photovoltaic bus bar.

[0033] Further,

[0034] The material of the box cover is aluminum alloy 6063-T5;

[0035] The soldering terminal and the photovoltaic cable are made of tinned copper material with a thermal conductivity greater than 380 W / (m.K);

[0036] The material of the heat-conducting gasket is at least one of the following materials: silica gel, metal oxide and boron nitride, and the thermal conductivity of the heat-conducting gasket is greater than 10 W / (m.K), and the thickness range is 0.5mm-1mm;

[0037] The wide-bandgap semiconductor material MOSFET is a silicon carbide MOSFET or a gallium nitride MOSFET.

[0038] The photovoltaic intelligent junction box provided by the utility model realizes the following effects:

[0039] 1. Since the novel low-voltage high-frequency MOSFET material has high electron mobility and low on-resistance, the overall scheme of the utility model can achieve the same current processing capacity with smaller device size. In addition to reducing power loss, the size of the circuit board is reduced by one-third compared with the silicon MOSFET scheme, so that the volume of the entire photovoltaic intelligent junction box is reduced, and the material cost is saved.

[0040] 2. When applied to a photovoltaic double-glass assembly, the utility model avoids shielding the back cell due to the small-volume long-strip design, which to some extent relieves the current mismatch problem and helps improve the subsequent power generation capacity.

[0041] 3. The heat dissipation column of the aluminum alloy box cover extending into the box body increases the heat dissipation capacity and also reduces the space inside the box body. The amount of subsequent pouring sealant is significantly reduced, and the material cost is also saved.

[0042] 4. The utility model discloses a photovoltaic cable is fixed to the circuit board through the welding terminal, although the material cost is increased, but the process that the photovoltaic cable is welded to the circuit board is simplified, and the production time is saved. Also avoid the defect in the welding process such as soldering tin deficiency, increase the stability and the tensile strength of photovoltaic cable fixation.

[0043] 5. The utility model discloses a photovoltaic split type terminal box positive box body and negative box body collocation use, when the photovoltaic module power test can connect test equipment only with positive box body and negative box body. At this time, only bypass diode works in intelligent terminal box, therefore will not produce influence to photovoltaic module electrical parameter.

[0044] Other features and advantages of the present utility model will be set forth in the following description of the utility model, and in part will become apparent from the description, or be learned by practice of the present utility model. The purpose and other advantages of the present utility model can be realized and obtained through the structure indicated in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will briefly introduce the drawing needed to be used in the embodiment or prior art description, obviously, the drawing in the following description is some embodiments of the utility model, and for the ordinary skilled person in the art, under the premise of not paying the creative labor, still can obtain other drawings according to these drawings.

[0046] Figure 1 The photovoltaic intelligent terminal box schematic diagram according to the embodiment of the utility model is shown;

[0047] Figure 2 The conventional photovoltaic terminal box use schematic diagram is shown;

[0048] Figure 3 The photovoltaic intelligent terminal box exploded view schematic diagram according to the embodiment of the utility model is shown;

[0049] Figure 4 The photovoltaic intelligent terminal box application schematic diagram on photovoltaic module according to the embodiment of the utility model is shown;

[0050] Figure 5 The box cover heat conduction structure schematic diagram of photovoltaic intelligent terminal box according to the embodiment of the utility model is shown;

[0051] Figure 6 The temperature sensor position schematic diagram of photovoltaic intelligent terminal box according to the embodiment of the utility model is shown. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely explained in combination with the drawings in the embodiments of the utility model below, obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the protection scope of the utility model.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application; the description and the drawings are to be regarded as illustrative in nature and are not intended to be limiting and the description herein including the claims uses the terms comprising and including to mean "including but not limited to". The terms first, second, third, etc. are used to distinguish different objects and are not to be construed as describing a particular order or sequence unless otherwise specified.

[0054] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is expressly understood that the embodiments described herein are merely examples from a whole class of comparable embodiments which those skilled in the art will readily appreciate.

[0055] Figure 1 The utility model provides a photovoltaic intelligent junction box schematic diagram, Figure 3 It is the exploded view schematic diagram of the photovoltaic intelligent junction box.

[0056] Referring to Figure 1 And Figure 3 The utility model provides a photovoltaic intelligent junction box 10 including casing 11, box cover 12, circuit board 13, 4 photovoltaic cables 8, cable pressing block 14, photovoltaic connector 9. The casing 11 is long strip shape casing, is provided with the fixed circuit board 13 in it. Circuit board 13 is connected with each photovoltaic cable 8 one end, and cable pressing block 14 is used for fixing each photovoltaic cable 8 on circuit board 13. Each photovoltaic cable 8 is led out from the end of casing 11, and two photovoltaic cables 8 are led out from the both ends of casing 11 respectively, and the other end of each photovoltaic cable 8 is equipped with photovoltaic connector 9.

[0057] The circuit board 13 is provided with a welding terminal 15 for connecting the photovoltaic cable 8, a bypass protection metal-oxide-semiconductor field-effect transistor (MOSFET) bypass switch 16 and a control circuit 17. The welding terminal 15 adopts a flattened design, i.e. a flat structure, to increase the contact area with the circuit board 13 and improve the overcurrent capacity and heat dissipation capacity. The bypass protection MOSFET bypass switch 16 and the control circuit 17 including a control chip are electrically isolated and work independently. The intelligent junction box 10 is provided with an input end, and each photovoltaic cable 8 is drawn from the housing 11 to serve as the input end for connecting the photovoltaic module 1. The intelligent junction box 10 is also provided with an output end for connecting a load. The MOSFET in the bypass protection MOSFET bypass switch 16 is a wide-bandgap semiconductor material MOSFET, which has the characteristics of low voltage, high frequency and high power, and can be a silicon carbide (SiC) MOSFET or a gallium nitride (GaN) MOSFET.

[0058] Figure 2 is a use schematic view of a conventional photovoltaic junction box, i.e. a conventional split-type junction box, Figure 4 is a use schematic view of the photovoltaic intelligent junction box on a photovoltaic module. Referring to Figure 2 and Figure 4 When the photovoltaic intelligent junction box 10 provided by the utility model is applied, the photovoltaic intelligent junction box 10 is used to replace the middle box body 3 of the junction box. The photovoltaic intelligent junction box 10 is connected with the cell string 7 in the photovoltaic module 1 through the welding of the busbar 6. The input end of the photovoltaic intelligent junction box 10 is connected with the negative box body 2 and the positive box body 4 of the conventional junction box through the photovoltaic cable 8 and the photovoltaic connector 9. Therefore, when there is voltage under illumination, the output voltage of the positive box body 4 and the negative box body 2 of the photovoltaic module 1 supplies power to the photovoltaic intelligent junction box 10, and the control circuit 17 works. At this time, the MOSFET bypass switch 16 also works normally. On the contrary, when the negative box body 2 and the positive box body 4 of the photovoltaic module 1 are disconnected with the photovoltaic intelligent junction box 10, the control circuit 17 cannot work due to no driving voltage. However, the MOSFET bypass switch 16 can still work normally. At this time, the photovoltaic module 1 is similar to the photovoltaic module with the conventional split-type junction box and can generate electricity and power normally.

[0059] Figure 5 is a cover heat conduction structure schematic view of the photovoltaic intelligent junction box 10 provided by the utility model. As Figure 5As shown, the box cover 12 for sealing the shell 11 is made of aluminum alloy, which extends to the inside of the shell 11 and is provided with multiple (more than one) heat dissipation columns 18. The end of the heat dissipation column 18 is opposite to the surface of the heat generating components on the circuit board 13 and the welding terminal 15. The gap between the end of the heat dissipation column 18 and the heat generating components on the circuit board 13 and the welding terminal 15 is filled with a heat conducting gasket 19. When the intelligent junction box 10 is working, most of the heat generated by the heat generating components is first conducted to the surface of the aluminum alloy box cover 12 through the heat conducting gasket 19 and the heat dissipation column 18, and then diffused to the air. A part of the heat that is not diffused to the air can be conducted to the welding terminal 15 through the heat dissipation column 18, and then conducted to the outside of the intelligent junction box 10 through the photovoltaic cable 8. A part of the heat on the circuit board 13 can be conducted to the outside of the intelligent junction box 10 through the welding terminal 15 and the photovoltaic cable 8. A part of the heat on the circuit board 13 can be conducted to the inside of the photovoltaic module 1 through the photovoltaic busbar 6, and then diffused to the air through the photovoltaic module 1.

[0060] Figure 6 The temperature sensor position diagram of the photovoltaic intelligent junction box 10 is provided. Figure 6 As shown, the photovoltaic busbar passes through the busbar perforation 21 and is welded to the busbar pad 22 on the circuit board 13. The temperature sensor 20 is arranged adjacent to the busbar pad 22 to collect the temperature of the busbar. The working temperature inside the photovoltaic module 1 can be more accurately understood. This will help to timely discover the temperature anomaly of the photovoltaic module 1 caused by hot spots or fire, and prevent trouble in advance. Two busbar perforations 21 are arranged on the circuit board 13, and the MOSFET bypass switch 16 is arranged at the middle position of the two busbar perforations 21. The purpose is to save the use space of the circuit board 13, and the heat generated by the MOSFET bypass switch 16 can be quickly conducted to the photovoltaic module 1 through the busbar on both sides.

[0061] Among them, it should be noted that:

[0062] 1. In order to reduce the high loss of the photovoltaic intelligent junction box during work, in the selection of circuit board components, a wide band gap semiconductor material MOSFET with low voltage, high frequency and high power characteristics is used to replace the conventional low voltage and low frequency silicon MOSFET. The wide band gap semiconductor material MOSFET has high breakdown voltage, high electron mobility and high thermal conductivity. This makes the MOSFET perform better than silicon MOS in high frequency, high power and high temperature applications. Lower on-resistance helps to reduce the power loss of the photovoltaic intelligent junction box, and the heat generation is significantly improved.

[0063] 2, The utility model uses MOSFET bypass switch instead of the conventional bypass diode as the bypass protection scheme. Its characteristics are low forward voltage, low power consumption and low heat generation. Therefore, when the MOSFET bypass switch is turned on, the temperature rise is significantly lower than that of the conventional bypass diode. The temperature of the intelligent terminal box during operation is effectively reduced.

[0064] 3, The utility model uses aluminum alloy such as aluminum alloy 6063-T5 instead of conventional plastic (such as polyphenylene oxide, PPO) as the cover of the photovoltaic intelligent terminal box to increase the heat dissipation effect. The thermal conductivity increases from 0.2 W / (m·K) to more than 200 W / (m·K). In addition, multiple aluminum alloy heat dissipation columns are added to the inside of the aluminum alloy cover for heat dissipation. The column body extends to the surface of the heat generating electronic components, which helps to quickly conduct the heat generated by the heat generating components to the outside of the box body. The entire cover is treated by anodizing process, and an oxide layer composed of aluminum oxide is added to the surface to play a pressure-resistant insulating role. The thickness of the oxide layer ranges from 10 μm to 15 μm. The surface of the anodized cover is rough, which enhances the adhesion between the cover and the potting glue inside the box body, and has better sealing performance.

[0065] 4, In order to increase the heat dissipation, the utility model uses a soldering terminal made of tinned copper material with a thermal conductivity of more than 380 W / (m·K) on the circuit board of the photovoltaic intelligent terminal box to connect the photovoltaic cable also made of the tinned copper material to the circuit board. The soldering terminal adopts a flattened design, closely fits the circuit board, increases the contact area to increase the current carrying capacity and heat dissipation capacity. There are also heat dissipation columns extending to the surface of the soldering terminal on the aluminum alloy cover mentioned above. The heat of the heat generating electronic components is conducted from the aluminum alloy cover to the soldering terminal, and then conducted to the outside of the box body through the photovoltaic cable.

[0066] 5, The utility model fills a heat conducting gasket between the aluminum alloy heat dissipation column and the heat generating components or the soldering terminal, which plays a role of pressure-resistant insulation and buffer protection of the components. The heat conducting gasket is made of conventional materials, including silica gel, metal oxide and boron nitride. The thermal conductivity is greater than 10 W / (m·K). The thickness is controlled within the range of 0.5 mm to 1 mm. If the thickness is too small, it cannot play a role of buffer protection of the components during the assembly process of the aluminum alloy cover, which may easily cause damage to the components. If the thickness is greater than 1 mm, it will affect the heat conduction to the aluminum alloy cover.

[0067] 6. The utility model discloses a high thermal conductivity (thermal conductivity is greater than 1W / (mK)) potting sealant with better liquidity (the viscosity of potting sealant is less than 3000mPa.s (millipascal second)) is used to seal the whole cavity of photovoltaic intelligent terminal box. Better liquidity helps to prevent air remaining in the cavity from affecting heat dissipation. Higher thermal conductivity is still to increase the heat dissipation of the whole product and conduct the heat generated by the product during operation to the outside of the box as soon as possible.

[0068] 7. The utility model discloses a MOSFET bypass switch and control circuit used in conventional terminal box are integrated on a circuit board, the function of the MOSFET bypass switch is used to replace one of the split terminal box, and is connected to the internal battery string of photovoltaic module through welding with bus bar. Photovoltaic intelligent terminal box is connected with other remaining conventional box through cable and connector, and is used in combination to meet the bypass protection function of all battery strings in photovoltaic module. Therefore, the internal circuit arrangement and production process of photovoltaic module using photovoltaic intelligent terminal box remain the same as the photovoltaic module using conventional photovoltaic terminal box. Therefore, no additional production cost is generated in the production process of photovoltaic module.

[0069] 8. The MOSFET bypass switch in the above is independently operated on the circuit board in the interior of photovoltaic intelligent terminal box. If the control circuit on the circuit board cannot work, the MOSFET bypass switch can still work normally and play a bypass protection role. Therefore, photovoltaic intelligent terminal box can be used in combination with other box as the split box of conventional photovoltaic terminal box. At this time, photovoltaic module with intelligent function will become conventional photovoltaic module again. It can generate electricity and test according to conventional photovoltaic module. The problem that the whole photovoltaic module cannot work due to the damage of photovoltaic intelligent terminal box is avoided.

[0070] The utility model discloses photovoltaic intelligent terminal box applied to photovoltaic module, and it has obvious performance advantage, cost advantage and installation simplicity. First, the utility model discloses photovoltaic intelligent terminal box solves the problem of high risk of circuit damage under high temperature environment of intelligent terminal box on the basis of realizing the intelligent function of photovoltaic intelligent terminal box through multiple technologies. During the circuit design process, the power consumption of intelligent terminal box is greatly reduced by applying MOSFET bypass switch and low-voltage high-frequency high-power MOSFET technologies, and the heat dissipation capacity is effectively improved by matching the box cover made of high-thermal-conductivity material and high-thermal-conductivity gasket. Secondly, the utility model discloses intelligent terminal box replaces the middle box of conventional split terminal box and is used in combination with the original positive box and negative box, reduces the loss caused by the damage of intelligent terminal box and solves the problem that the electrical parameters are affected by intelligent circuit during power test of photovoltaic module.

[0071] Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features therein can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. A photovoltaic intelligent junction box, characterized in that, It comprises: a shell, a box cover, a circuit board, 4 photovoltaic cables, a cable pressing block, a photovoltaic connector, wherein, the shell is a long strip-shaped shell, which is internally provided with the circuit board fixed therein, the circuit board is connected with one end of each of the photovoltaic cables, the cable pressing block is used to fix each of the photovoltaic cables to the circuit board; each of the photovoltaic cables is led out from the end of the shell, and the other end of each of the photovoltaic cables is provided with the photovoltaic connector; two of the photovoltaic cables are led out from each of the two ends of the shell, respectively; the circuit board is provided with a soldering terminal for connecting the photovoltaic cable, a bypass protection MOSFET bypass switch and a control circuit, the soldering terminal adopts a flattened design, i.e. a flat structure, the bypass protection MOSFET bypass switch is electrically isolated from the control circuit; two bus bar perforations are provided on the circuit board, the MOSFET bypass switch is arranged at the middle position of the two bus bar perforations, and a photovoltaic bus bar is welded to a bus bar pad on the circuit board through the bus bar perforation.

2. The photovoltaic intelligent junction box according to claim 1, wherein each of the photovoltaic cables is an input end of the photovoltaic intelligent junction box, and the photovoltaic intelligent junction box is connected with a cell string in a photovoltaic module through bus bar welding.

3. The photovoltaic intelligent junction box according to claim 2, wherein the input end of the photovoltaic intelligent junction box is connected with a negative box body and a positive box body of a conventional split junction box through the photovoltaic cable and the photovoltaic connector.

4. The photovoltaic intelligent junction box according to claim 3, wherein the MOSFET in the bypass protection MOSFET bypass switch is a wide bandgap semiconductor material MOSFET.

5. The photovoltaic intelligent junction box according to claim 4, wherein the box cover is used to seal the shell and is made of an aluminum alloy material.

6. The photovoltaic intelligent junction box according to claim 5, wherein a plurality of heat dissipation columns are arranged on the box cover and extend into the shell, the end portions of the plurality of heat dissipation columns are opposite to the surfaces of the heat generating components and the soldering terminals on the circuit board, and the gaps between the plurality of heat dissipation columns and the heat generating components and the soldering terminals are filled with heat conductive gaskets.

7. The photovoltaic intelligent junction box according to claim 6, wherein the box cover is treated by an anodization process, and an oxide layer is added to the surface thereof.

8. The photovoltaic intelligent junction box according to claim 7, wherein a sealing glue with a viscosity less than 3000 mPa.s and a thermal conductivity coefficient greater than 1 W / (m·K) is used to seal the entire cavity of the photovoltaic intelligent junction box.

9. The photovoltaic intelligent junction box according to any one of claims 1-8, further comprising a temperature sensor, wherein the temperature sensor is arranged adjacent to the bus bar pad and is used to collect the temperature of the photovoltaic bus bar.

10. The photovoltaic intelligent junction box according to claim 7, wherein the material of the box cover is an aluminum alloy 6063-T5. ​ The welding terminal and the photovoltaic cable are made of tinned copper material with a thermal conductivity of more than 380 W / (m*K); The material of the heat-conducting gasket is one of the following: silica gel, metal oxide and boron nitride, and the heat-conducting gasket has a thermal conductivity of more than 10 W / (m*K) and a thickness ranging from 0.5 mm to 1 mm; The wide-bandgap semiconductor material MOSFET is a silicon carbide MOSFET or a gallium nitride MOSFET.

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