Three-phase string-type photovoltaic grid-connected device

Abstract

This utility model discloses a three-phase string photovoltaic grid-connected device, belonging to the field of photovoltaic grid-connected inverters. The three-phase string photovoltaic grid-connected device of this utility model includes a housing, with a heat sink at the rear end of the housing. The heat sink has second mounting slots at both its upper and lower ends, and first fans are installed on both sides of the two second mounting slots. This utility model solves the problem of existing three-phase photovoltaic inverters where the lack of an additional air-driven structure at the heat sink location affects the heat dissipation efficiency. The first fans installed at the second mounting slots at the upper and lower ends of the heat sink can draw gas from the middle, allowing the gas to be transferred towards the upper and lower ends of the heat sink for active heat transfer and heat dissipation, thus improving the heat dissipation speed. The reserved first and second mounting slots provide a stable heat dissipation trajectory.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic grid-connected inverters, specifically a three-phase string photovoltaic grid-connected device. Background Technology

[0002] The core of a three-phase string photovoltaic grid-connected equipment is built upon a three-phase string photovoltaic grid-connected inverter. It collects the DC power generated by multiple photovoltaic strings and converts it into three-phase AC power that meets grid requirements through the inverter, achieving stable grid connection. This equipment has high-efficiency power conversion capabilities, can accurately track the maximum power point, and improve power generation efficiency. At the same time, it has comprehensive protection functions, such as overvoltage, overcurrent, and islanding protection, to ensure the safe operation of the equipment and the grid. It is a key device for achieving efficient grid connection in photovoltaic power generation systems. Chinese patent CN205407618U discloses an intelligent string-type three-phase photovoltaic inverter, including a top cover, a faceplate, a protective plate, a display board PCB, an I / O board, an internal fan, a main power board PCB, a control board, a heat sink, and a mounting plate. The top cover 1 is directly installed on the heat sink 17, and the main power board PCB 15 and the control board 16, etc., are directly installed on the heat dissipation substrate 21 of the heat sink 13. The internal fan 14 provides forced air cooling for the boost inductor 12 of the control board 16. This patent application has the advantages of simple structure, good heat dissipation, reasonable layout, and easy assembly and maintenance.

[0003] In the aforementioned patented three-phase photovoltaic inverter, no additional air-driven structure is installed at the heat sink location during heat dissipation. As a result, after the heat is transferred to the heat sink location, there is no high-speed airflow to carry away the heat, which affects the heat dissipation efficiency of the three-phase photovoltaic inverter. Summary of the Invention

[0004] The purpose of this utility model is to provide a three-phase string photovoltaic grid-connected device. The first fan installed at the second mounting slots at the upper and lower ends inside the heat sink can draw gas from the middle position, so that the gas can be transferred to the upper and lower ends inside the heat sink and actively transfer heat to the heat sink to dissipate heat, thereby improving the heat dissipation speed. The reserved first and second reserved slots can provide a stable heat dissipation trajectory, thus solving the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a three-phase string photovoltaic grid-connected device, including a housing, a heat sink at the rear end of the housing, a second mounting groove at both the upper and lower ends of the heat sink, a first fan on both sides of the two second mounting grooves, a second reserved groove recessed in the middle of the heat sink, the gas extraction positions of the two second mounting grooves facing the second reserved groove, and a bracket welded to both sides of the heat sink, with a first reserved groove corresponding to the second reserved groove at the middle position of the bracket.

[0006] Preferably, the front end of the bracket is provided with a housing, and the four corners of the heat sink are fixedly connected to the four corners of the housing by bolts.

[0007] Preferably, a connecting piece is provided at the rear end of the second mounting slot, and a second mounting hole is recessed on the side of the connecting piece facing the first fan, and the second mounting hole is fixedly connected to the first fan by bolts.

[0008] Preferably, the upper and lower ends of the second mounting hole are both recessed and provided with first mounting grooves.

[0009] Preferably, both sides of the connecting piece extend to both sides of the bracket, and the sides of the connecting piece and the sides of the bracket are fixedly connected by bolts.

[0010] Preferably, the lower end of the outer casing is provided with a second heat dissipation hole to provide heat dissipation capability, and the sides and the upper end of the outer casing are provided with first heat dissipation holes.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: After the heat from the outer casing is transferred to the heat sink, the first fan installed at the second mounting slots at the upper and lower ends of the heat sink can draw gas from the middle position. This allows the gas to be transferred to the upper and lower ends of the heat sink and actively transfer heat to the heat sink, thus improving the heat dissipation speed. The reserved first and second slots can provide a stable heat dissipation trajectory, preventing the heat sink from being too close to the installation position for a long time, which would affect the heat dissipation speed and cause heat accumulation. This improves the stability and heat dissipation capacity of the three-phase string photovoltaic grid-connected equipment during long-term operation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall external structure of this utility model; Figure 2 This is an exploded view of the overall structure of this utility model; Figure 3 This is an exploded view of the cover plate installation position of this utility model; Figure 4This is a schematic diagram of the gas flow trajectory inside the heat sink of this utility model.

[0013] In the diagram: 1. Outer shell; 2. Bracket; 3. Heat sink; 4. Connecting piece; 5. First reserved slot; 6. Cover plate; 7. First mounting hole; 8. First mounting slot; 9. Second mounting hole; 10. First fan; 11. Second fan; 12. First heat dissipation hole; 13. Third fan; 14. Second reserved slot; 15. Second mounting slot; 16. Second heat dissipation hole; 17. Mounting frame. Detailed Implementation

[0014] The present invention will be further described below with reference to specific embodiments.

[0015] like Figure 1 , Figure 2 and Figure 4 As shown, a three-phase string photovoltaic grid-connected device in this embodiment includes a housing 1. A heat sink 3 is provided at the rear end of the housing 1. A second mounting groove 15 is provided at both the upper and lower ends inside the heat sink 3. A first fan 10 is provided on both sides inside the two second mounting grooves 15. The first fan 10 installed inside the heat sink 3 can provide efficient heat dissipation and avoid the inefficient dissipation of heat after it is transferred to the heat sink 3.

[0016] Furthermore, a second reserved groove 14 is provided in the middle of the heat sink 3. The positions of the two second mounting grooves 15 for extracting gas are both facing the position of the second reserved groove 14. After the first fan 10 is turned on, the extracted gas flows into the heat sink 3 through the position of the second reserved groove 14. Both sides of the heat sink 3 are provided with brackets 2 for installation, and the brackets 2 are welded and fixed to the heat sink 3. The front end of the bracket 2 is provided with a shell 1. The control board is installed between the shell 1 and the bracket 2. The heat generated by the control board is absorbed by the heat sink 3 and then discharged. The shell 1 and the heat sink 3 protect the control board by wrapping it.

[0017] The bracket 2 has a first reserved slot 5 in the middle position corresponding to the second reserved slot 14. Through the correspondence between the first reserved slot 5 and the second reserved slot 14, after the first fan 10 draws the second reserved slot 14, the external gas passes through the first reserved slot 5 and enters the interior of the second reserved slot 14 to complete the heat dissipation. The reserved second reserved slot 14 and the first reserved slot 5 provide heat dissipation capacity, and avoid the two sides of the second reserved slot 14 being completely restricted by the bracket 2, which would reduce the cooling capacity.

[0018] In addition, the four corners of the heat sink 3 are fixedly connected to the four corners of the outer casing 1 by bolts. Connecting the heat sink 3 and the outer casing 1 at the four corners facilitates installation and maintenance of the internal structure.

[0019] To facilitate the installation of the first fan 10, a connecting piece 4 is provided at the rear end of the second mounting slot 15. The side of the connecting piece 4 facing the first fan 10 is recessed with a second mounting hole 9, and the second mounting hole 9 is fixedly connected to the first fan 10 by bolts. The upper and lower ends of the second mounting hole 9 are both recessed with a first mounting groove 8. The recessed first mounting groove 8 facilitates the passage of bolts and the installation of the connecting piece 4. The connecting piece 4 can be pre-installed in the required fixed position.

[0020] Furthermore, in order to complete the connection between the connecting piece 4 and the bracket 2, and also to complete the installation of the first fan 10, so that the first fan 10 is installed inside the second mounting slot 15, both sides of the connecting piece 4 extend to both sides of the bracket 2. When installing the bracket 2 and the connecting piece 4, the connecting piece 4 covers the side of the bracket 2, and the side of the connecting piece 4 is fixedly connected to the side of the bracket 2 by bolts. The connection between the bracket 2 and the heat sink 3 and the connecting piece 4 can be completed by bolts.

[0021] It is worth mentioning that, in order to actively cool the area covered by the outer casing 1 and the heat sink 3, a second heat dissipation hole 16 is provided at the lower end of the outer casing 1 to provide heat dissipation capability. External air enters between the outer casing 1 and the heat sink 3 through the second heat dissipation hole 16. A second fan 11 is horizontally arranged in the middle between the outer casing 1 and the heat sink 3. The exhaust position of the second fan 11 corresponds to the high-heat position of the control board, and the second fan 11 is started by entering between the outer casing 1 and the heat sink 3 through the second heat dissipation hole 16.

[0022] To facilitate the dissipation of heat from the interior of the outer casing 1, and to accommodate this heat dissipation, such as... Figure 3 As shown, the outer casing 1 has first heat dissipation holes 12 on both sides and the top. The reserved first heat dissipation holes 12 facilitate the direct discharge of heat. The inner wall of the outer casing 1 is provided with a mounting frame 17 corresponding to the position of the first heat dissipation hole 12, and the mounting frame 17 is welded and fixed to the outer casing 1. The mounting frame 17 is provided with a third fan 13 inside, and the third fan 13 is fixedly connected to the mounting frame 17 by bolts. The mounting frame 17 can provide for the installation and removal of the third fan 13. Each first heat dissipation hole 12 corresponds to a third fan 13, which can meet the heat dissipation needs of the corresponding position.

[0023] To accommodate different installation orientations and positions, and to prevent foreign objects from easily entering the housing 1 through the first heat dissipation hole 12 due to the installation orientation, a sheet-like cover plate 6 is provided inside the first heat dissipation hole 12. The cover plate 6 is fixedly connected to the housing 1 by bolts. After the bolts penetrate the cover plate 6 and are embedded inside the housing 1, the first heat dissipation hole 12 is prevented from being exposed, and the heat dissipation of the first heat dissipation hole 12 cannot be covered. This can cope with extreme installation positions.

[0024] The outer wall of the outer casing 1 is recessed and has a first mounting hole 7. The reserved first mounting hole 7 provides a mounting position for the removable cover plate 6.

[0025] In this application, the power input terminals of the first fan 10, the second fan 11, and the third fan 13 are all coupled to the low-voltage DC output terminal of the auxiliary power supply built into the device. The provision of an auxiliary power supply to dissipate heat from the first fan 10, the second fan 11, and the third fan 13 is a conventional technical means, and therefore will not be elaborated on in this application.

[0026] Referring to Chinese Patent Publication No. CN205407618U, a smart string-type three-phase photovoltaic inverter is disclosed. The application details a DC switch, an AC connector, an H4 connector, and an RS-485 interface. The inverter is connected through these interfaces to realize the connection of the photovoltaic string group to the inverter and the connection of the inverter to the three-phase power grid. This connection method and the use of the corresponding connection interfaces are conventional technical means. Therefore, this application does not elaborate too much on the DC switch, AC connector, H4 connector, and RS-485 interface, nor does it elaborate too much on the operation of the control board.

[0027] Working Principle: During the use and installation of the device, bolts are first inserted through the first mounting slot 8 and embedded in the fixed position, thus fixing the connecting piece 4 in the required position. Bolts then pass through the first fan 10 and are embedded in the second mounting hole 9 of the connecting piece 4. The bracket 2 is installed facing the connecting piece 4. Bolts are then inserted through the sides of the connecting piece 4 and the bracket 2 in sequence, fixing the bracket 2 and the connecting piece 4. The first fan 10 will then be located in the second mounting slot 15. This completes the fixing of the three-phase string photovoltaic grid-connected equipment in the required installation position. After the three-phase string photovoltaic grid-connected equipment is put into use and generates heat, the heat is transferred to the heat sink 3, activating the first fan 10 inside the two second mounting slots 15. The first fan 10 then activates its suction force to draw gas, causing... After the gas flows through the first reserved slot 5 and the second reserved slot 14, the heat dissipation gas can flow efficiently along the heat sink 3, achieving efficient cooling of the heat sink 3. At the same time, the second fan 11 starts and draws external gas from the second heat dissipation hole 16 into the housing 1. The second heat dissipation hole 16 provides forced air cooling to the boost inductor of the control board. To meet the heat dissipation requirements, the first heat dissipation hole 12 corresponding to the heat dissipation direction is removed, and the bolts that penetrate the cover plate 6 and are embedded in the housing 1 are rotated and removed, allowing the cover plate 6 to be removed and the first heat dissipation hole 12 to be exposed. The heat inside the housing 1 can be drawn by the third fan 13 and directly discharged from the first heat dissipation hole 12, thereby achieving internal and external heat dissipation during long-term use of the equipment.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0029] 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.

Claims

1. A three-phase string photovoltaic grid-connected device, characterized in that, The device includes a housing (1), a heat sink (3) is provided at the rear end of the housing (1), a second mounting groove (15) is provided at both the upper and lower ends of the heat sink (3), a first fan (10) is provided on both sides of the two second mounting grooves (15), a second reserved groove (14) is provided in the middle of the heat sink (3), the gas extraction positions of the two second mounting grooves (15) are all facing the second reserved groove (14), a bracket (2) is welded on both sides of the heat sink (3), and a first reserved groove (5) is provided in the middle position of the bracket (2) corresponding to the second reserved groove (14).

2. The three-phase string photovoltaic grid-connected equipment according to claim 1, characterized in that, The front end of the bracket (2) is provided with a shell (1), and the four corners of the heat sink (3) are fixedly connected to the four corners of the shell (1) by bolts.

3. A three-phase string photovoltaic grid-connected device according to claim 2, characterized in that, The rear end of the second mounting groove (15) is provided with a connecting piece (4). The side of the connecting piece (4) facing the first fan (10) is recessed with a second mounting hole (9), and the second mounting hole (9) is fixedly connected to the first fan (10) by bolts.

4. A three-phase string photovoltaic grid-connected device according to claim 3, characterized in that, The second mounting hole (9) has a first mounting groove (8) recessed at both the upper and lower ends.

5. A three-phase string photovoltaic grid-connected device according to claim 4, characterized in that, Both sides of the connecting piece (4) extend to both sides of the bracket (2), and the side of the connecting piece (4) and the side of the bracket (2) are fixedly connected by bolts.

6. A three-phase string photovoltaic grid-connected device according to claim 5, characterized in that, The lower end of the outer shell (1) is provided with a second heat dissipation hole (16) to provide heat dissipation capability, and the outer shell (1) is provided with a first heat dissipation hole (12) on both sides and the upper end.

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