Maintenance-free photovoltaic inverter control device

Abstract

The invention belongs to the technical field of photovoltaic power generation, and discloses a maintenance-free photovoltaic inverter control device which comprises a protective shell and a protective cover clamped at the upper end of the protective shell, a control panel is embedded in the upper end of the protective cover, the front end of the protective shell is connected with a panel, and a circuit board and a transformer are arranged in the protective shell. The protective shell is in bolted connection with the protective cover, the heat exchange plate is fixed to the bottom of the protective shell, the lower ends of the circuit board and the transformer are both connected with the heat exchange plate, and the side face of the circuit board is connected with the heat conduction fins. According to the maintenance-free photovoltaic inverter control device, an efficient multi-stage heat transfer network is constructed, and heat conduction fins, a first heat conduction plate, a sealing pipe, a second heat conduction plate and a circulating groove are matched, so that the heat exchange area is enlarged, the heat transfer speed is increased, and the heat exchange efficiency is remarkably improved; heat of electrical components such as a circuit board and a transformer can be quickly absorbed and dissipated, meanwhile, a circulation pipeline is designed, and efficient heat dissipation of the electrical components is achieved through circulation of cooling liquid.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, specifically to a maintenance-free photovoltaic inverter control device. Background Technology

[0002] As the core component of a photovoltaic power generation system, the photovoltaic inverter is responsible for converting the direct current generated by the solar panels into alternating current that can be connected to the grid or used directly. Its operational stability and service life directly affect the power generation efficiency of the entire photovoltaic system. However, traditional photovoltaic inverter control devices face problems such as insufficient heat dissipation efficiency, poor dust protection performance, and high maintenance costs during long-term operation, which seriously restricts their application in complex outdoor environments. In terms of heat dissipation, traditional photovoltaic inverter control devices integrate a large number of heat-generating components such as circuit boards and transformers. These components continuously generate heat during operation, and if they cannot be dissipated in a timely and effective manner, the internal temperature of the device will rise.

[0003] Existing photovoltaic inverter control devices still have certain problems in use: A photovoltaic inverter control device, as described in Chinese patent application number CN202222383409.9, includes a protective frame, an inverter, a limiting buffer assembly, an adjusting and fixing assembly, and a heat dissipation assembly. The protective frame is a hollow cavity with an opening on one side. The limiting buffer assembly and the adjusting and fixing assembly are respectively connected to two opposite inner walls of the protective frame. The inverter is located inside the protective frame and is connected between the limiting buffer assembly and the adjusting and fixing assembly. The heat dissipation assembly is connected to the inner top of the protective frame.

[0004] Existing photovoltaic inverter control devices require heat dissipation structures to prevent internal temperature rise. However, these structures need filters to prevent dust from entering. These filters block dust but are also prone to clogging, requiring regular maintenance and incurring high maintenance costs.

[0005] To address the aforementioned issues, an innovative design was implemented based on the existing maintenance-free photovoltaic inverter control device. Summary of the Invention

[0006] The purpose of this invention is to provide a maintenance-free photovoltaic inverter control device to solve the problem mentioned in the background art that existing photovoltaic inverter control devices suffer from dust clogging of the filter screen due to filtration, requiring regular maintenance and cleaning, resulting in high maintenance costs.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a maintenance-free photovoltaic inverter control device, comprising a protective housing and a protective cover engaged at the upper end, a control board embedded in the upper end of the protective cover, a panel connected to the front end of the protective housing, and a circuit board and a transformer disposed inside the protective housing. The protective housing is bolted to the protective cover. A heat exchange plate is fixed to the bottom of the protective housing. The lower ends of the circuit board and the transformer are both connected to the heat exchange plate. Heat-conducting fins are connected to the side of the circuit board and are in contact with the heat exchange plate. The heat exchange plate has a circulation groove inside, and a sealing tube is connected to the upper end of the heat exchange plate. The sealing tube is filled with a heat-deformation material. The protective shell is filled with a liquid storage tank, which is connected to the circulation groove. The left end of the sealing tube is connected to the left end of the circulation groove.

[0008] Preferably, the circulation tank is arranged in an "S" shape, a return pipe is connected between the right end of the circulation tank and the storage tank, the left end of the sealing pipe is connected to a first one-way valve and is conductively connected to the left end of the circulation tank, the right end of the sealing pipe is connected to a second one-way valve, the second one-way valve is connected to an inlet pipe, and the upper end of the inlet pipe is conductively connected to the storage tank.

[0009] By adopting the above technical solution, the flow direction of the coolant can be strictly controlled by setting the first one-way valve and the second one-way valve. Directional control can prevent backflow in the system and ensure that the coolant circulates stably along the designed path. The cooperation of the sealing pipe, circulation tank, inlet pipe and return pipe constitutes the circulation pipeline to realize the circulation of coolant.

[0010] Preferably, the liquid storage tank is connected to fins at both the upper and lower ends, and the fins are distributed in an equidistant array.

[0011] By adopting the above technical solution, coolant can be stored in the liquid storage tank so that the inverter control device can be cooled when the coolant circulates. At the same time, the array of fins can improve heat dissipation efficiency and improve the heat dissipation of the liquid storage tank.

[0012] Preferably, the heat-deformable material is symmetrically distributed inside the sealed tube. The heat-deformable material is a composite material of copper sheet and polyimide film. The polyimide film is bonded to the opposite sides of the two sets of heat-deformable materials. After heating, the heat-deformable material will bend towards the polyimide side and return to straight after cooling.

[0013] Using the above technical solution, the thermoplastic material adopts a composite structure of "copper sheet + polyimide film". It utilizes the significant difference in the thermal expansion coefficients of the two materials to achieve efficient deformation. When the temperature rises, the expansion of the copper sheet side is much greater than that of the polyimide side, and the material will bend towards the polyimide side. When the temperature drops, the copper sheet contracts and the whole thing returns to a straight shape. This "temperature difference driven deformation" characteristic can achieve rapid and autonomous response to temperature changes without additional power. It is suitable for scenarios that require automatic temperature control. The combination of copper sheet and polyimide film also takes into account temperature resistance, durability and functionality, and achieves multiple advantages such as no-power temperature control response, stable deformation output and long-term durability.

[0014] Preferably, the upper end of the heat-conducting fins is connected to a first heat-conducting plate, and the front end of the first heat-conducting plate is attached to the upper end of the sealing tube. The lower end of the sealing tube is connected to a second heat-conducting plate, and the lower end of the second heat-conducting plate extends into the circulation groove. The second heat-conducting plates are distributed in an equidistant array.

[0015] By adopting the above technical solution, through the design of the first heat-conducting plate and the second heat-conducting plate, heat can be transferred to the sealed tube in real time and to the coolant inside the sealed tube, accelerating the heat exchange rate. This allows the thermal deformation material inside the sealed tube to more accurately sense temperature changes, ensuring that its deformation action is highly matched with the system temperature requirements. In case of overheating, it can quickly trigger deformation to regulate the flow rate.

[0016] Preferably, the protective housing is connected to air ducts on both sides, a guide fan is connected to the inside of the air ducts, a protective cover is connected to the outside end of the air ducts, an air inlet is opened in the array of the protective cover, and a second fan is embedded in both sides of the panel.

[0017] By adopting the above technical solution, a three-dimensional airflow circulation system is constructed through the combination of air ducts, guide fans, and a second fan. The guide fans are symmetrically distributed on both sides of the protective shell, which can draw in cold air from the outside to form a transverse airflow channel, quickly removing the accumulated heat inside the shell. The second fan forms an auxiliary airflow from the front of the equipment, complementing the airflow from the air ducts on both sides, avoiding ventilation dead corners inside the shell. The design of side main ventilation and front auxiliary ventilation greatly increases the air exchange rate between the inside and outside of the shell, which is especially suitable for equipment with dense heat-generating components and can effectively prevent performance degradation or failure caused by high temperature.

[0018] Preferably, a filter screen is fixed in the middle of the air duct, and a scraper is provided on the outside of the filter screen, with both ends of the scraper being slidably connected to both ends of the filter screen.

[0019] The above technical solution uses a filter located in the middle of the duct to effectively intercept dust, particulate matter, lint and other impurities in the air, preventing them from entering the equipment with the airflow. The combination design of the filter and the sliding scraper, through the dual functions of interception and active cleaning, maintains ventilation efficiency while ensuring the cleanliness of the equipment, reduces maintenance costs, and significantly improves the long-term reliability of the entire system. It is especially suitable for operating environments with a lot of dust and impurities.

[0020] Preferably, the outer side of the air guide fan is connected to a drive gear, the inner wall of the air duct is rotatably connected to a driven gear, the driven gear meshes with the drive gear, the outer edge of the driven gear is connected to a drive shaft, the two ends of the scraper are connected to a drive plate, a drive groove is opened in the middle of the drive plate, and the drive shaft extends into the drive groove to form a sliding structure.

[0021] The above technical solution directly utilizes the rotation of the airflow fan as a power source: when the fan is working, the outer drive gear rotates synchronously, driving the driven gear to rotate through gear meshing, and then driving the scraper to move through the cooperation of the transmission shaft and the transmission plate. There is no need to configure an independent power device such as a motor or battery, which reduces energy consumption and saves installation space inside the air duct, making the overall structure more compact. It is especially suitable for miniaturized or integrated equipment. While achieving automatic cleaning of the filter, it also takes into account the advantages of energy saving, compactness, and reliability, significantly improving the long-term stability and ease of use of the ventilation system. It is especially suitable for equipment that needs to operate continuously and without human intervention.

[0022] Preferably, a discharge hole is provided at the lower outer end of the air duct, and the discharge hole is distributed on the outer side of the filter screen.

[0023] By adopting the above technical solution, dust will adhere to the surface of the filter screen, and the scraper will scrape off the dust on the surface of the filter screen during the reciprocating motion, thereby realizing the dust discharge.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: This maintenance-free photovoltaic inverter control device, by constructing a highly efficient multi-stage heat transfer network, expands the heat exchange area and accelerates the heat transfer speed through the cooperation of heat-conducting fins, a first heat-conducting plate, a sealing pipe, a second heat-conducting plate and a circulation tank, significantly improving the heat exchange efficiency. It can quickly absorb and dissipate the heat of electrical components such as circuit boards and transformers. At the same time, the design of the circulation pipeline enables efficient heat dissipation of electrical components through the circulation of coolant.

[0025] 1. The setting of the first and second check valves strictly controls the flow direction of the coolant, prevents backflow, ensures stable circulation of the coolant along the designed path, guarantees the stability of temperature control, and, in conjunction with the self-extrusion structure, the heat-deformable material inside the sealing tube can deform autonomously according to temperature changes. After the temperature rises, the two sets of heat-deformable materials bend towards the middle, extruding the internal space of the sealing tube, and the internal coolant flows out through the check valve and into the coolant at a lower temperature, thereby achieving cooling. This realizes automatic temperature control of the coolant circulation, making the temperature control more precise and adapting to different temperature requirements of the system. 2. The design incorporates an air-cooled structure to further assist in cooling. If the liquid-cooled circulation structure cannot cool the device in time during prolonged high-power operation, the air-cooled cooling structure can be activated. The liquid-cooled system and the air-cooled system work together to significantly improve the overall heat dissipation capacity, effectively preventing the impact of high temperatures on the device's performance. Furthermore, the active cleaning structure is driven by the power of the guide fan to reciprocate, uniformly and thoroughly removing deposits from the filter screen, maintaining the filter screen's permeability, and ensuring smooth ventilation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic cross-sectional view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the circuit board and heat-conducting fin structure of the present invention; Figure 4 This is a schematic diagram of the liquid inlet pipe and liquid storage tank structure of the present invention; Figure 5 This is a schematic diagram of the sealing tube and the first one-way valve structure of the present invention; Figure 6 This is a schematic diagram of the heat exchange plate and circulation tank structure of the present invention; Figure 7 This is a schematic diagram of the sealing tube and heat-deformable material structure of the present invention; Figure 8 This is a schematic diagram of the duct and protective cover structure of the present invention; Figure 9 This is a schematic diagram of the driven gear and transmission shaft structure of the present invention; Figure 10 This is a schematic diagram of the transmission shaft and transmission plate structure of the present invention.

[0027] In the diagram: 1. Protective housing; 2. Protective cover; 3. Control board; 4. Panel; 5. Circuit board; 6. Heat-conducting fins; 7. Transformer; 8. Heat exchange plate; 9. Circulation tank; 10. Sealing pipe; 11. First check valve; 12. Second check valve; 13. Return pipe; 14. Liquid inlet pipe; 15. First heat-conducting plate; 16. Liquid storage tank; 17. Second heat-conducting plate; 18. Thermal deformation material; 19. Air duct; 20. Guide fan; 21. Protective cover; 22. Filter screen; 23. Drive gear; 24. Driven gear; 25. Drive shaft; 26. Scraper; 27. Transmission plate; 28. Second fan. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1-10 The present invention provides the following technical solutions.

[0030] Example 1: This invention provides a technical solution: a maintenance-free photovoltaic inverter control device, comprising a protective housing 1 and a protective cover 2 that engages at the top. The protective housing 1 and the protective cover 2 form a hollow box, providing a dustproof and moisture-proof protective space for internal components. A control board 3 is embedded in the upper end of the protective cover 2. A mounting groove is reserved at the upper end of the protective cover 2, and the control board 3 is embedded in the groove and fixed by a snap fastener. The wiring terminals of the control board 3 extend through the reserved through holes in the protective cover 2 into the interior of the housing, achieving electrical connection with the circuit board 5. A panel 4 is connected to the front end of the protective housing 1, and the front end of the protective housing 1 is fixed to the panel 4 by screws. The panel 4 is made of high-temperature resistant insulating material, and its surface is provided with operation buttons and indicator lights. A circuit board 5 and a transformer 7 are disposed inside the protective housing 1. The protective housing 1 is bolted to the protective cover 2. A heat exchange plate 8 is fixed to the bottom of the protective housing 1. The lower ends of the circuit board 5 and the transformer 7 are both connected to the heat exchange plate 8. Heat-conducting fins 6 are connected to the side of the circuit board 5, and the heat-conducting fins 6 are in contact with the heat exchange plate 8. Circuit board 5 and transformer 7 are attached to heat exchange plate 8 at the bottom of protective housing 1 by heat dissipation silicone pad. The heat-conducting fins 6 on the side of circuit board 5 are fixed by welding, and the bottom of the fins are in close contact with heat exchange plate 8 to ensure rapid heat conduction.

[0031] A circulation groove 9 is formed inside the heat exchange plate 8. A sealing pipe 10 is connected to the upper end of the heat exchange plate 8. A heat-deformable material 18 is placed inside the sealing pipe 10. A liquid storage tank 16 is set inside the protective shell 1. The liquid storage tank 16 is connected to the circulation groove 9. The left end of the sealing pipe 10 is connected to the left end of the circulation groove 9. The circulation groove 9 is distributed in an "S" shape. The heat exchange plate 8 is made by one-piece molding process. The cross-section of the circulation groove 9 is circular. This shape design can extend the flow path of the coolant in the heat exchange plate 8, increase the heat exchange time and heat exchange uniformity. A return pipe 13 is connected between the right end of the circulation groove 9 and the liquid storage tank 16. The left end of the sealing pipe 10 is connected to the first one-way valve 11, and the first one-way valve 11 is connected to the left end of the circulation groove 9. The right end of the sealing pipe 10 is connected to the second one-way valve 12. The second one-way valve 12 is connected to the liquid inlet pipe 14. The upper end of the liquid inlet pipe 14 is connected to the liquid storage tank 16. Fins are connected to the upper and lower ends of the liquid storage tank 16. The fins are distributed in an equidistant array. Thermodeformable material 18 is symmetrically distributed inside the sealing tube 10. The thermodeformable material 18 is a composite material of copper sheet and polyimide film. The polyimide film is bonded to the opposite sides of the two sets of thermodeformable materials 18. After heating, the thermodeformable material 18 will bend towards the polyimide side and return to straight after cooling. The thermodeformable material 18 is composed of copper sheet and polyimide film. The copper sheet is 0.2 mm thick and the polyimide film is 0.1 mm thick. They are bonded together with high-temperature resistant adhesive, and the polyimide film is bonded to the opposite sides of the two sets of thermodeformable materials 18. The upper end of the heat-conducting fin 6 is connected to the first heat-conducting plate 15, and the front end of the first heat-conducting plate 15 is attached to the upper end of the sealing tube 10. The upper end of the heat-conducting fin 6 is connected to the first heat-conducting plate 15 by welding. The first heat-conducting plate 15 is made of pure copper with a thickness of 2 mm. The front end is tightly attached to the upper end of the sealing tube 10, and thermal grease is applied to the bonding surface to reduce thermal resistance. The lower end of the sealing tube 10 is connected to a second heat-conducting plate 17, and the lower end of the second heat-conducting plate 17 extends into the circulation tank 9. The second heat-conducting plates 17 are distributed in an equidistant array.

[0032] During device operation, the heat generated by circuit board 5 and transformer 7 is absorbed by the heat exchange plate 8 attached to the bottom and transferred to the circulating coolant inside the circulation tank 9. The heat generated by circuit board 5 is also simultaneously transferred to the heat-conducting fins 6. The heat-conducting fins 6 transfer the heat to the sealing tube 10 through the first heat-conducting plate 15. The bottom of the heat-conducting fins 6 can further improve the efficiency of heat transfer to the heat exchange plate 8. By using the second heat-conducting plate 17 in conjunction with the first heat-conducting plate 15, heat can be transferred to the coolant inside the sealing tube 10 simultaneously. The sealing tube 10 is made of aluminum alloy. When the temperature of the sealing tube 10 rises due to heat absorption, the internal coolant and the heat-deformation material 18 heat up together. After the temperature of the heat-deformation material 18 rises, it bends towards the polyimide side, and the internal space of the sealing tube 10 is squeezed, causing the coolant inside the sealing tube 10 to flow from the second one-way valve 12 to the inlet pipe 14 and then back to the storage tank 16. Because the inside of the liquid storage tank 16 is a sealed design, when the liquid inlet pipe 14 injects coolant into it, the same volume of coolant flows out through the return pipe 13 and flows into the circulation tank 9, pushing the coolant inside the circulation tank 9 into the sealing pipe 10 through the first one-way valve 11. The coolant flowing inside the circulation tank 9 has a lower temperature and is transferred to the sealing pipe 10. After the temperature drops, the thermal deformation material 18 resets.

[0033] Example 2: This invention provides another technical solution. The difference between this example and Example 1 is that an air-cooling structure is added to the liquid-cooling cycle of Example 1. Through the coordinated operation of liquid cooling and air cooling, malfunctions caused by excessive temperature in the photovoltaic inverter control device are further avoided. Temperature sensors are installed at multiple points inside the protective housing 1 and inside the liquid storage tank 16. When the temperature of the liquid storage tank 16 rises to a set value due to insufficient heat dissipation, the air-cooling structure is activated. Air ducts 19 are connected to both sides of the protective housing 1. A guide fan 20 is connected to the inner side of the air duct 19, and a protective cover 21 is connected to the outer end of the air duct 19. The protective cover 21 has arrayed air inlets. Square mounting holes are reserved on both sides of the protective housing 1. The air duct 19 has a square structure, and the outer end of the air duct 19 is connected to the protective cover 21 by a buckle. The protective cover 21 is made of metal. The panel 4 has a second fan 28 embedded on both sides; the air duct 19 has a filter screen 22 fixed in the middle, and a scraper 26 is provided on the outside of the filter screen 22, with the two ends of the scraper 26 slidably connected to the two ends of the filter screen 22; the guide fan 20 is connected to the outside of the drive gear 23, and the inner wall of the air duct 19 is rotatably connected to the driven gear 24, which meshes with the drive gear 23. The outer edge of the driven gear 24 is connected to the drive shaft 25, and the two ends of the scraper 26 are connected to the drive plate 27. The drive plate 27 has a drive groove in the middle, and the drive shaft 25 extends into the drive groove to form a sliding structure; the lower outer end of the air duct 19 has a discharge hole, which is distributed on the outside of the filter screen 22. When the device is running, the guide fan 20 and the second fan 28 start at the same time. The guide fan 20 draws in cold air from the outside, which is initially filtered by the protective cover 21 and then enters the air duct 19, and flows into the protective shell 1. After mixing with the hot air inside the shell, it is discharged by the second fan 28, forming a continuous airflow circulation that carries away the heat inside the shell. Simultaneously, the guide fan 20 drives the drive gear 23 to rotate, which in turn drives the driven gear 24. The drive shaft 25 on the driven gear 24 slides within the transmission groove of the transmission plate 27, causing the scraper 26 to reciprocate along the surface of the filter screen 22. The number of reciprocations per minute matches the rotational speed of the driven gear 24. The scraper 26 scrapes off the dust and impurities adhering to the filter screen 22. The impurities are discharged through the discharge hole under gravity and can be fitted with a dust collection box. When the device stops operating, the fan stops rotating, and the scraper 26 also stops moving. This structure achieves simultaneous ventilation and dust removal without the need for an additional power source. It ensures ventilation efficiency while reducing clogging of the filter screen 22, eliminating the need for regular cleaning and maintenance like traditional filters and ensuring long-term stable operation of the device.

[0034] The contents not described in detail in this specification are prior art known to those skilled in the art. 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 variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A maintenance-free photovoltaic inverter control device, comprising a protective shell (1) and a protective cover (2) engaged at the upper end, and a control board (3) embedded in the upper end of the protective cover (2), wherein the front end of the protective shell (1) is connected with a panel (4), and the inside of the protective shell (1) is provided with a circuit board (5) and a transformer (7), characterized in that: the protective shell (1) is bolted with the protective cover (2), the bottom of the protective shell (1) is fixed with a heat exchange plate (8), the lower end of the circuit board (5) and the transformer (7) are connected with the heat exchange plate (8), and the side of the circuit board (5) is connected with a heat-conducting fin (6) in contact with the heat exchange plate (8). The inside of the heat exchange plate (8) is provided with a circulating groove (9), the upper end of the heat exchange plate (8) is connected with a sealed pipe (10), the inside of the sealed pipe (10) is provided with a thermal deformation material (18), the inside of the protective shell (1) is provided with a liquid storage tank (16), the liquid storage tank (16) is communicated with the circulating groove (9), and the left end of the sealed pipe (10) is communicated with the left end of the circulating groove (9). The circulating groove (9) is distributed in an "S" shape, a return pipe (13) is connected between the right end of the circulating groove (9) and the liquid storage tank (16), the left end of the sealed pipe (10) is connected with a first one-way valve (11), the first one-way valve (11) is communicated with the left end of the circulating groove (9), the right end of the sealed pipe (10) is connected with a second one-way valve (12), the second one-way valve (12) is connected with a liquid inlet pipe (14), and the upper end of the liquid inlet pipe (14) is communicated with the liquid storage tank (16).

2. A maintenance free photovoltaic inverter control device according to claim 1, characterized in that: The upper and lower ends of the liquid storage tank (16) are connected with fins, and the fins are distributed in an equidistant array.

3. A maintenance-free photovoltaic inverter control device according to claim 2, characterized in that: The thermal deformation material (18) is symmetrically distributed in the sealed pipe (10), the thermal deformation material (18) is a composite material of copper sheet and polyimide film, the polyimide film is adhered to the opposite sides of the two groups of thermal deformation materials (18), the thermal deformation material (18) will bend to the side of the polyimide after heating, and will restore flat after cooling.

4. A maintenance free photovoltaic inverter control device as claimed in claim 1, wherein: The upper end of the heat-conducting fin (6) is connected with a first heat-conducting plate (15), the front end of the first heat-conducting plate (15) is attached to the upper end of the sealed pipe (10), the lower end of the sealed pipe (10) is connected with a second heat-conducting plate (17), the lower end of the second heat-conducting plate (17) extends into the circulating groove (9), and the second heat-conducting plate (17) is distributed in an equidistant array.

5. A maintenance-free photovoltaic inverter control device according to claim 4, characterized in that: The two sides of the protective shell (1) are connected with air pipes (19), the inner side of the air pipe (19) is connected with a guide fan (20), the outer side of the air pipe (19) is connected with a protective cover (21), the protective cover (21) is arrayed with air inlet holes, and the two sides of the panel (4) are embedded with second fans (28).

6. A maintenance free photovoltaic inverter control device as claimed in claim 1, wherein: The middle of the air pipe (19) is fixed with a filter screen (22), the outer side of the filter screen (22) is provided with a scraping strip (26), and the two ends of the scraping strip (26) are slidingly connected with the two ends of the filter screen (22).

7. A maintenance-free photovoltaic inverter control device according to claim 6, characterized in that: ​ 8. A maintenance-free photovoltaic inverter control device according to claim 7, characterized in that: The guide fan (20) is connected with a driving gear (23) outside, the inner wall of the air pipe (19) is rotatably connected with a driven gear (24), the driven gear (24) is connected with the driving gear (23) in meshing mode, the outer edge of the driven gear (24) is connected with a transmission shaft (25), the scraping strips (26) are connected with transmission plates (27) at two ends, the middle part of the transmission plate (27) is provided with a transmission groove, and the transmission shaft (25) extends into the transmission groove and forms a sliding structure.

9. A maintenance free photovoltaic inverter control device according to claim 8, characterized in that: The lower end of the outer side of the air pipe (19) is provided with a discharging hole, and the discharging hole is distributed outside the filter screen (22).

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