AC / DC hybrid and multi-voltage adaptation ring main unit

Abstract

The application relates to the technical field of power equipment, in particular to a ring network box capable of mixing AC and DC and adapting to multiple voltages, which comprises an outer sealed shell, an inner sealed shell and a nitrogen supply device, a main sealed cavity is formed in the outer sealed shell, the inner sealed shell is installed in the main sealed cavity, power equipment is installed in the inner sealed shell through a sealed unit cavity, and the nitrogen supply device is used for supplying nitrogen into the sealed unit cavity. The ring network box is protected by the outer sealed shell and the inner sealed shell, so that dust cannot enter the main sealed cavity, air cannot directly contact the power equipment in the sealed unit cavity, the different power equipment is isolated through the sealed unit cavity, and the power equipment is protected and radiated through nitrogen, therefore, the power equipment can be effectively protected from the influence of air and the interference of other faulty equipment, and the integrated operation mode of mixing AC and DC and adapting to multiple voltages can be maintained.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, specifically to a ring main unit with AC / DC hybrid and multi-voltage adaptability. Background Technology

[0002] With advancements in power equipment technology, outdoor ring main units (RMMs) have become the mainstream choice for installation. Simultaneously, the increasing intelligence of power systems has led to a growing demand for multi-voltage levels and DC power supply, such as for various monitoring devices requiring DC power. Therefore, current RMMs are increasingly pursuing primary and secondary integration, combining primary power distribution equipment with secondary protection, control, and monitoring equipment for unified management. This necessitates that RMMs achieve AC / DC hybrid operation and multi-voltage compatibility.

[0003] Traditional ring main units (RMUs) are primarily designed for AC power and a few centralized voltage levels, and typically rely on the RMU's own protection (such as gas protection) to meet safety requirements. However, for RMUs that integrate AC / DC hybrid power and multi-voltage adaptability, additional protection measures are required because they contain a large number of electrical devices that lack their own protection.

[0004] Patent CN217406039 discloses a primary and secondary integrated ring main unit with cooling function. This solution uses vents to cool the electrical equipment, but the direct contact of air with the equipment can easily lead to dust and moisture, causing power failures. Existing technologies also have solutions for dust removal and dehumidification, but these solutions cannot guarantee long-term trouble-free operation of the dehumidification and dust removal equipment; once the equipment fails, moisture and dust in the air will still directly contact the electrical equipment, posing a risk. Therefore, they are insufficient to meet the safety requirements of modern ring main units. In view of this, this application provides a ring main unit with AC / DC hybrid and multi-voltage adaptability. Summary of the Invention

[0005] This invention provides the following technical solution: a ring main unit with AC / DC hybrid and multi-voltage adaptability, comprising:

[0006] The outer sealing housing has a main sealing cavity inside. The left and right sides of the outer sealing housing are equipped with pressurized air pumps to send external air filtered by a dust filter into the main sealing cavity, thereby maintaining the air pressure in the main sealing cavity higher than that of the external air. The front and rear sides of the outer sealing housing are sealed with outer sealing doors, and the outer sealing doors are equipped with one-way exhaust valves that only allow air to be discharged from the main sealing cavity to the outside.

[0007] An inner sealing shell is fixed inside the main sealing cavity, and at least six sealing unit cavities for installing power equipment units are opened inside the inner sealing shell. The power equipment corresponding to all the power equipment units located in the inner sealing shell includes at least a high-voltage ring main unit, a low-voltage ring main unit, a transformer, a DC power supply cabinet, a rectifier, and an inverter, and each power equipment unit corresponds to one of the power equipment.

[0008] A nitrogen supply device is installed in the main sealing cavity, and the nitrogen supply device supplies nitrogen at a specified pressure to the sealing unit cavity through a unit cavity supply valve corresponding to each sealing unit cavity.

[0009] Preferably, a main controller is installed on the top of the main sealing cavity, and a second sensor group is provided in each sealing unit cavity for detecting the internal air pressure, temperature and nitrogen concentration of the sealing unit cavity. The main controller is electrically connected to the pressurized air pump, the unit cavity air supply valve and the second sensor group respectively.

[0010] Preferably, the nitrogen supply device includes a heat-insulating shell fixedly installed in the main sealing cavity, and a vacuum chamber is provided inside the heat-insulating shell. A nitrogen tank that is connected to the unit cavity gas supply valve and supplies nitrogen is fixed inside the vacuum chamber. A semiconductor cooler for cooling the nitrogen tank is fixed on the heat-insulating shell. A first temperature sensor for detecting the temperature of the nitrogen tank is fixedly installed on the heat-insulating shell. The main controller is electrically connected to the semiconductor cooler and the first temperature sensor respectively.

[0011] Preferably, the front end of the sealing unit cavity is sealed by an inner sealing door, and a heat sink is fixedly installed on the inner sealing door to facilitate the transfer of heat located in the sealing unit cavity to the main sealing cavity. An operation panel electrically connected to the main controller is fixedly installed on the inner sealing door.

[0012] Preferably, the bottom of the sealing unit cavity is provided with an exhaust pump for discharging the gas in the corresponding sealing unit cavity into the outside air, and the exhaust pump is electrically connected to the main controller.

[0013] Preferably, a heat exchanger is fixedly installed in the main sealing cavity, and each sealing unit cavity is provided with a unit cavity suction pump and a unit cavity return valve at its upper and lower ends, respectively. The unit cavity suction pump is connected to the heat source inlet of the heat exchanger and draws nitrogen gas located in the sealing unit cavity into the heat exchanger. The unit cavity return valve is connected to the heat source outlet of the heat exchanger and sends nitrogen gas located in the heat exchanger back into the sealing unit cavity. The cold source inlet of the heat exchanger sends air located in the main sealing cavity into the heat exchanger through an air supply pump, and the cold source outlet of the heat exchanger sends air located in the heat exchanger into the outside air through a second exhaust pipe. The main controller is electrically connected to the unit cavity suction pump, the unit cavity return valve, and the air supply pump, respectively.

[0014] Preferably, a fixed housing is fixedly installed on the left and right sides of the outer sealing housing, and a dust filter is installed at the inlet end of the fixed housing. The outlet end of the fixed housing is connected to the inlet end of the pressurized air pump. A dust filter device for filtering air is provided inside the fixed housing. A first sensor group for detecting the temperature, humidity and air pressure of the air in the main sealing cavity is fixedly installed below the sealing housing, and the main controller is electrically connected to the first sensor group.

[0015] Preferably, the dust filtration device is one or more of a dust collector bag, an electrostatic precipitator, or an activated carbon filter packing, and a rain cover is provided on the outside of the fixed housing to prevent rainwater from entering the dust filter.

[0016] Preferably, the end of the pressurized air pump is connected to a ceramic heat insulation tube, and the interior of the ceramic heat insulation tube is filled with moisture-absorbing filler, which is one or more of sponge, silica gel, or molecular sieve. A heater for heating and drying the moisture-absorbing filler is installed on the ceramic heat insulation tube, and a second temperature sensor for detecting the temperature of the moisture-absorbing filler is fixedly installed on the ceramic heat insulation tube. The end of the ceramic heat insulation tube is connected to an air distribution pipe and a first exhaust pipe through a reversing solenoid valve. The first exhaust pipe is used to discharge the air inside the ceramic heat insulation tube to the outside air, and the air distribution pipe is used to send air into the main heat source located in the main sealing cavity through at least three pairs of hoses connected to the end.

[0017] Compared with the prior art, the beneficial effects of the AC / DC hybrid and multi-voltage adaptable ring main unit of the present invention are:

[0018] 1. With the dual protection of the outer and inner sealing shells, dust cannot enter the main sealing cavity, and air cannot directly contact the electrical equipment located in the sealing unit cavity, thus effectively avoiding power failures caused by dust and moisture carried by the air.

[0019] 2. A sealed unit cavity is used to separate electrical equipment with different functions and voltages, and nitrogen is used as a protective gas to enhance the protection of the electrical equipment. At the same time, nitrogen can also be used for efficient heat dissipation, thus effectively improving the safety of the electrical equipment.

[0020] 3. By ensuring that the air pressure inside the main sealing cavity is greater than that outside the air, and the air pressure inside the sealing unit cavity is greater than that inside the main sealing cavity, even if there is a slight leak in the outer sealing shell and the inner sealing shell, dust in the outside air cannot enter the main sealing cavity, and air inside the main sealing cavity cannot enter the sealing unit cavity. Therefore, the fault caused by contact between air and electrical equipment is completely solved. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 This is a cross-sectional view of the structure of the present invention;

[0023] Figure 3 This is a longitudinal sectional view of the structure of the present invention;

[0024] Figure 4 This is a schematic diagram of the installation of the inner sealing shell, heat exchanger, and nitrogen supply device in this invention;

[0025] Figure 5 This is a side view showing the installation of the inner sealing shell, heat exchanger, and nitrogen supply device in this invention;

[0026] Figure 6 This is a schematic diagram showing the internal cross-section of the ceramic heat insulation tube and the fixed shell in this invention.

[0027] In the diagram: 1. Outer sealing housing; 2. Nitrogen supply device; 201. First temperature sensor; 202. Heat insulation housing; 203. Semiconductor cooler; 204. Vacuum chamber; 205. Nitrogen tank; 3. Airflow distribution pipe; 4. First sensor group; 5. Dust filter; 6. Pressurized air pump; 7. Moisture-absorbing packing; 8. Heater; 9. Ceramic heat insulation tube; 10. Second temperature sensor; 11. Reversing solenoid valve; 12. First exhaust pipe; 13. Fixed housing; 14. Rainproof 15. Dust filter; 16. Exhaust pump; 17. Unit cavity return valve; 18. Second exhaust pipe; 19. Heat exchanger; 20. Air supply pump; 21. Inner sealing housing; 22. Second sensor group; 23. Operation panel; 24. Inner sealing door; 25. Heat sink; 26. Unit cavity air pump; 27. Unit cavity air supply valve; 28. One-way exhaust valve; 29. ​​Outer sealing door; 30. Main sealing cavity; 31. Sealed unit cavity; 32. Power equipment unit; 33. Main controller. Detailed Implementation

[0028] To clearly and completely describe the objectives and technical solutions of this invention, and to more clearly illustrate its advantages, the embodiments of this invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of this invention, and are merely used to explain the embodiments of this invention. They are not intended to limit the embodiments of this invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] Example 1: Please refer to Figures 1 to 6This invention provides a ring main unit with AC / DC hybrid and multi-voltage adaptability, including an outer sealing shell 1, an inner sealing shell 21, and a nitrogen supply device 2. The outer sealing shell 1 forms a main sealing cavity 30, and the left and right sides of the outer sealing shell 1 are equipped with pressurized air pumps 6 to send external air filtered by dust filter 15 into the main sealing cavity 30, thereby maintaining the air pressure in the main sealing cavity 30 higher than that of the external air. The front and rear sides of the outer sealing shell 1 are sealed by outer sealing doors 29, and the outer sealing doors 29 are equipped with one-way exhaust valves 28 that only allow air to be discharged from the main sealing cavity 30 to the outside. After the pressurized air pump 6 delivers outside air into the main sealing cavity 30, the air pressure inside the main sealing cavity 30 becomes higher than the air pressure outside. This allows the air inside the main sealing cavity 30 to open the one-way exhaust valve 28 and flow into the outside air. The one-way exhaust valve 28 can be a spring valve. Simultaneously, because the air pressure inside the main sealing cavity 30 is higher than the air pressure outside, outside air cannot easily flow into the main sealing cavity 30 from other parts. It can only be delivered into the main sealing cavity 30 by the pressurized air pump 6 and then flow out through the one-way exhaust valve 28, thus preventing dust from entering the main sealing cavity 30 from other locations. A main controller 33 is installed on the top of the main sealing cavity 30.

[0030] Please see Figures 2 to 5 An inner sealing shell 21 is fixed inside the main sealing cavity 30, and at least six sealing unit cavities 31 are opened inside the inner sealing shell 21 for installing power equipment units 32. The power equipment corresponding to all the power equipment units 32 located in the inner sealing shell 21 includes at least high-voltage ring main units, low-voltage ring main units, transformers, DC power supply cabinets, rectifiers, and inverters, and each power equipment unit 32 corresponds to one type of power equipment. Depending on the needs, PLC equipment for monitoring the power network and communication equipment for communicating with the power control center can also be installed in the sealing unit cavities 31. Other power equipment can also be installed as needed, thereby realizing AC / DC hybrid and multi-voltage adaptation functions, meeting the high integration requirements of existing power systems for primary power distribution and secondary protection, monitoring, and control. The front end of the sealed unit cavity 31 is sealed by an inner sealing door 24, and a heat sink 25 is fixedly installed on the inner sealing door 24 to facilitate the transfer of heat from the sealed unit cavity 31 to the main sealed cavity 30. An operation panel 23 electrically connected to the main controller 33 is fixedly installed on the inner sealing door 24. Control commands can be issued to the main controller 33 or the operating status of the main controller 33 can be viewed through the operation panel 23. An exhaust pump 16 is provided at the bottom of the sealed unit cavity 31 to discharge the gas in the corresponding sealed unit cavity 31 to the outside air. The exhaust pump 16 is electrically connected to the main controller 33. The exhaust pump 16 is used to discharge the air in the sealed unit cavity 31, so that the nitrogen supply device 2 can fill the sealed unit cavity 31 with nitrogen, thereby using nitrogen to achieve the protection function of electrical equipment.

[0031] Please see Figures 2 to 5 The nitrogen supply device 2 is installed in the main sealing cavity 30, and the nitrogen supply device 2 supplies nitrogen 2 at a specified pressure to the sealing unit cavity 31 through the unit cavity supply valve 27 corresponding to each sealing unit cavity 31. The nitrogen supply device 2 includes a heat insulation shell 202 fixedly installed in the main sealing cavity 30, and a vacuum chamber 204 is provided in the heat insulation shell 202. A nitrogen tank 205 connected to the unit cavity supply valve 27 and supplying nitrogen is fixed in the vacuum chamber 204. A semiconductor cooler 203 for cooling the nitrogen tank 205 is fixed on the heat insulation shell 202. A first temperature sensor 201 for detecting the temperature of the nitrogen tank 205 is fixedly installed on the heat insulation shell 202, and the main controller 33 is electrically connected to the semiconductor cooler 203 and the first temperature sensor 201 respectively. The vacuum chamber 204 effectively isolates heat transfer, preventing heat from the main sealed chamber 30 from being effectively transferred to the nitrogen tank 205. Combined with the semiconductor cooler 203, the nitrogen tank 205 is cooled, effectively maintaining it at a suitable storage temperature. The first temperature sensor 201 monitors the temperature of the nitrogen tank 205 in real time, facilitating the main controller 33 to adjust the operating state of the semiconductor cooler 203. Each sealed unit cavity 31 is equipped with a second sensor group 22 for detecting the internal air pressure, temperature, and nitrogen concentration. The second sensor group 22 includes a pressure sensor, a temperature sensor, and a nitrogen concentration sensor to perform the aforementioned detection functions. The main controller 33 is electrically connected to the pressurized air pump 6, the unit cavity air supply valve 27, and the second sensor group 22.

[0032] Working Principle: During operation, the air pressure inside the main sealing chamber 30 is maintained higher than that of the outside air by the pressurizing air pump 6. This prevents outside air from entering the main sealing chamber 30 even if there are minor cracks in the outer sealing shell 1. Instead, outside air must pass through the dust filter 15 to remove dust before being pumped into the main sealing chamber 30 by the pressurizing air pump 6. The air is then vented in one direction by the one-way exhaust valve 28. This effectively prevents dust in the air from contaminating the interior of the main sealing chamber 30, thus reducing the occurrence of electrical accidents. Furthermore, the inner sealing shell 21 can accommodate at least six sealing unit cavities 31 to house electrical equipment with different functions and voltages. This prevents mutual interference between different electrical equipment in case of failure. For example, static electricity and arcing generated during high-voltage equipment failure can affect the operational stability of other electrical equipment, thus achieving effective isolation and protection. Furthermore, nitrogen can be supplied to each sealed unit cavity 31 for protection via the nitrogen supply device 2. Specifically, the air in the sealed unit cavity 31 is first extracted using the exhaust pump 16, and then pure nitrogen is introduced into the sealed unit cavity 31 using the nitrogen supply device 2. This effectively protects the electrical equipment with nitrogen. This process is repeated every time the inner sealing door 24 is opened, ensuring that the sealed unit cavity 31 is in a pure nitrogen environment during operation. At the same time, the nitrogen pressure in the sealed unit cavity 31 is maintained at a higher level than the air pressure in the main sealing cavity 30, effectively preventing air from the main sealing cavity 30 from entering the sealed unit cavity 31, thus ensuring the effectiveness of nitrogen protection. The main controller 33 detects the nitrogen pressure and nitrogen concentration in the corresponding sealed unit cavity 31 through the second sensor group 22. When the nitrogen pressure is low, it will open the corresponding unit cavity gas supply valve 27 to replenish nitrogen. When the nitrogen concentration is lower than the preset value, it will first discharge the gas in the sealed unit cavity 31 through the exhaust pump 16, and then supply pure nitrogen to the sealed unit cavity 31 again through the nitrogen supply device 2, thereby maintaining the sealed unit cavity 31 in an effective nitrogen protection state. When internal equipment malfunctions and requires repair, maintenance personnel first open the outer sealing door 29, and then issue a maintenance waiting command to the main controller 33 via the main controller 33 or the operation panel 23. At this time, the pressurized air pump 6 will stop working, and all unit chamber air supply valves 27 will be closed. Subsequently, the maintenance personnel open the corresponding inner sealing door 24 to maintain the corresponding electrical equipment. After maintenance is completed, the maintenance personnel close the inner sealing door 24 again and issue a maintenance end command to the main controller 33. Then, the maintenance personnel close the outer sealing door 29. After receiving the maintenance end command, the main controller 33 waits for a specified time interval, such as two minutes, and then restarts the pressurized air pump 6. Then, the nitrogen gas inside the corresponding sealed unit chamber 31 is replaced again through the exhaust pump 16 and the unit chamber air supply valve 27, thereby ensuring that any sealed unit chamber 31 is within the effective protection range of nitrogen.By adopting the above methods, dust prevention, mutual interference prevention, and nitrogen protection can be effectively achieved for power equipment with different functions and voltages, thereby ensuring that the ring main unit can achieve AC / DC hybrid and multi-voltage adaptation and stable operation.

[0033] Example 2: Please refer to Figures 2 to 5 Based on Embodiment 1, a heat exchanger 19 is fixedly installed in the main sealing cavity 30, and a unit cavity suction pump 26 and a unit cavity return valve 17 are respectively provided at the upper and lower ends of each sealing unit cavity 31. The unit cavity suction pump 26 is connected to the heat source inlet of the heat exchanger 19 and draws nitrogen gas located in the sealing unit cavity 31 into the heat exchanger 19. The unit cavity return valve 17 is connected to the heat source outlet of the heat exchanger 19 and sends nitrogen gas located in the heat exchanger 19 back into the sealing unit cavity 31. The cold source inlet of the heat exchanger 19 sends air located in the main sealing cavity 30 into the heat exchanger 19 through the air supply pump 20, and the cold source outlet of the heat exchanger 19 sends air located in the heat exchanger 19 into the outside air through the second exhaust pipe 18. The main controller 33 is electrically connected to the unit cavity suction pump 26, the unit cavity return valve 17 and the air supply pump 20 respectively. The heat exchanger 19 can be a plate heat exchanger. Through the heat exchanger 19, nitrogen gas located in the sealed unit cavity 31 can be used as a heat transfer medium to quickly exchange the heat in the sealed unit cavity 31 with the air located in the main sealed cavity 30, and then exhaust this air to the outside air. In this process, nitrogen gas not only protects the electrical equipment located in the sealed unit cavity 31, but also acts as a heat transfer medium to achieve efficient cooling of these electrical equipment. At the same time, the whole process is carried out in a closed loop, which will not be contaminated by external media, and will not allow moisture in the outside air to enter the sealed unit cavity 31. Therefore, both the cooling effect and the safety of the electrical equipment are guaranteed. When maintenance personnel need to maintain the electrical equipment in the sealed unit cavity 31, the corresponding unit cavity air pump 26 and unit cavity return valve 17 will be closed, thereby isolating the sealed unit cavity 31 from other sealed unit cavities 31 and preventing air from flowing from the cooling circuit of the heat exchanger 19 to other sealed unit cavities 31. After the maintenance is completed, the maintenance personnel will issue a maintenance completion command to the main controller 33 to restore the corresponding unit cavity air pump 26 and unit cavity return valve 17 to work.

[0034] Example 3: Please refer to Figure 1 , Figure 2 and Figure 6Based on Embodiment 2, a fixed housing 13 is fixedly installed on the left and right sides of the outer sealing housing 1, and a dust filter 15 is installed at the inlet end of the fixed housing 13. The outlet end of the fixed housing 13 is connected to the inlet end of the pressurized air pump 6. A dust filter device 5 for filtering air is provided inside the fixed housing 13. A first sensor group 4 for detecting the temperature, humidity and air pressure of the air in the main sealing cavity 30 is fixedly installed below the outer sealing housing 1. The first sensor group 4 is equipped with a temperature detection sensor, a humidity detection sensor and an air pressure detection sensor to realize the above detection functions. The main controller 33 is electrically connected to the first sensor group 4. When the first sensor group 4 detects that the air pressure in the main sealing cavity 30 is lower than the preset value or the temperature is higher than the preset value, the main controller 33 will control the pressurized air pump 6 to operate at a higher power. Otherwise, the pressurized air pump 6 will operate at a lower power to save energy. The dust filtration device 5 is one or more of the following: a dust collector bag, an electrostatic precipitator, or activated carbon filter media. A rain cover 14 is provided on the outside of the fixed housing 13 to prevent rainwater from entering the dust filter 15. The further filtration by the dust filtration device 5 can effectively prevent dust from entering the main sealing cavity 30, and the dust filtration device 5 can be replaced at any time, thereby ensuring the best dust filtration effect.

[0035] Example 4: Please refer to Figure 1 , Figure 2 and Figure 6Based on Embodiment 3, the end of the pressurized air pump 6 is connected to a ceramic heat-insulating tube 9, and the interior of the ceramic heat-insulating tube 9 is filled with a moisture-absorbing filler 7, which is one or more of sponge, silica gel, or molecular sieve. A heater 8 for heating and drying the moisture-absorbing filler 7 is installed on the ceramic heat-insulating tube 9, and a second temperature sensor 10 for detecting the temperature of the moisture-absorbing filler 7 is fixedly installed on the ceramic heat-insulating tube 9. The end of the ceramic heat-insulating tube 9 is connected to the air distribution pipe 3 and the first exhaust pipe 12 through a reversing solenoid valve 11. The first exhaust pipe 12 is used to exhaust the air located in the ceramic heat-insulating tube 9. The air is released into the outside air, and the air distribution pipe 3 is used to deliver air to the main heat source located in the main sealing cavity 30 through at least three pairs of hoses connected to the end. The moisture-absorbing filler 7 can effectively absorb moisture in the air, so that the air entering the main sealing cavity 30 can meet the humidity requirements. When the first sensor group 4 detects that the humidity in the main sealing cavity 30 exceeds the preset value, it indicates that the moisture-absorbing filler 7 needs to be dehydrated. At this time, the main controller 33 will control the pressurized air pump 6 to stop working, and then use the reversing solenoid valve 11 to connect the end of the ceramic heat insulation tube 9 to the first exhaust pipe 12, and then... Heater 8 begins heating the moisture-absorbing packing 7. The main controller 33 can detect the surface temperature of the moisture-absorbing packing 7 via the second temperature sensor 10. When the temperature on the moisture-absorbing packing 7 rises to the preset dehumidification temperature, the moisture inside the packing 7 will evaporate into water vapor and be discharged through the first exhaust pipe 12. This state is maintained for a specified time, such as fifteen minutes, to ensure that the moisture inside the moisture-absorbing packing 7 is completely removed. Afterward, heater 8 stops working, and pressurized air pump 6 is turned on. The air supplied by pressurized air pump 6 is used to cool the moisture-absorbing packing 7. The generated air after cooling... The airflow will also be discharged from the first exhaust pipe 12, thus preventing heat from remaining in the main sealing cavity 30. When the moisture-absorbing packing 7 is cooled to below a specified temperature, such as below 40 degrees Celsius, cooling is considered complete. At this time, the reversing solenoid valve 11 connects the end of the ceramic heat insulation tube 9 to the airflow distribution pipe 3, thereby using the airflow distribution pipe 3 to properly distribute the airflow provided by the pressurized air pump 6 to the heat sources located in the main sealing cavity 30. These heat sources can be heat sinks 25, main controllers 33, etc. The user can decide where the airflow distribution pipe 3 needs to distribute the airflow to via the hose as needed. The ceramic heat insulation tube 9 can effectively prevent heat transfer to the air in the main sealing cavity 30 when the moisture-absorbing packing 7 is heated, thus avoiding unnecessary heat loss. After the moisture-absorbing packing 7 is dehydrated, the air that the pressurized air pump 6 sends into the main sealing cavity 30 again through the airflow distribution pipe 3 can be considered dry air. This dry air can be used to discharge the moisture in the main sealing cavity 30 through the one-way exhaust valve 28, thereby effectively reducing the humidity in the main sealing cavity 30. Therefore, it can further prevent malfunctions caused by excessive humidity inside the ring network box, ensuring the safety of equipment use.

[0036] Although the illustrative specific embodiments of this application have been described above to enable those skilled in the art to understand this application, this application is not limited to the scope of the specific embodiments. For those skilled in the art, all applications utilizing the concept of this application are protected as long as various variations are within the spirit and scope of this application as defined and determined by the appended claims.

Claims

1. A ring main unit with AC / DC hybrid and multi-voltage adaptability, characterized in that, include: An outer sealing housing (1) is formed inside a main sealing cavity (30). The left and right sides of the outer sealing housing (1) are equipped with a pressurized air pump (6) to send external air filtered by a dust filter (15) into the main sealing cavity (30), thereby maintaining the air pressure in the main sealing cavity (30) higher than that of the external air. The front and rear sides of the outer sealing housing (1) are sealed with an outer sealing door (29), and a one-way exhaust valve (28) is installed on the outer sealing door (29) to allow air to be discharged from the main sealing cavity (30) to the outside. The inner sealing housing (21) is fixed inside the main sealing cavity (30), and the inner sealing housing (21) has at least six sealing unit cavities (31) for installing power equipment units (32). All power equipment units (32) located in the inner sealing housing (21) correspond to at least high voltage ring network cabinets, low voltage ring network cabinets, transformers, DC power supply cabinets, rectifiers and inverters, and each power equipment unit (32) corresponds to one type of power equipment. Nitrogen supply device (2) is installed in the main sealing cavity (30) and supplies nitrogen (2) at a specified pressure to the sealing unit cavity (31) through the unit cavity supply valve (27) corresponding to each sealing unit cavity (31).

2. The AC / DC hybrid and multi-voltage adaptable ring main unit according to claim 1, characterized in that: A main controller (33) is installed on the top of the main sealing cavity (30). Each sealing unit cavity (31) is provided with a second sensor group (22) for detecting the internal air pressure, temperature and nitrogen concentration of the sealing unit cavity (31). The main controller (33) is electrically connected to the pressurized air pump (6), the unit cavity air supply valve (27) and the second sensor group (22).

3. The AC / DC hybrid and multi-voltage adaptable ring main unit according to claim 2, characterized in that: The nitrogen supply device (2) includes a heat insulation shell (202) fixedly installed in the main sealing cavity (30), and a vacuum cavity (204) is provided in the heat insulation shell (202). A nitrogen tank (205) connected to the unit cavity gas supply valve (27) and supplying nitrogen is fixed in the vacuum cavity (204). A semiconductor cooler (203) for cooling the nitrogen tank (205) is fixed on the heat insulation shell (202). A first temperature sensor (201) for detecting the temperature of the nitrogen tank (205) is fixedly installed on the heat insulation shell (202). The main controller (33) is electrically connected to the semiconductor cooler (203) and the first temperature sensor (201) respectively.

4. A ring main unit with AC / DC hybrid and multi-voltage adaptability according to claim 2, characterized in that: The front end of the sealed unit cavity (31) is sealed by an inner sealing door (24), and a heat sink (25) is fixedly installed on the inner sealing door (24) to facilitate the transfer of heat in the sealed unit cavity (31) to the main sealing cavity (30). An operation panel (23) electrically connected to the main controller (33) is fixedly installed on the inner sealing door (24).

5. A ring main unit with AC / DC hybrid and multi-voltage adaptability according to claim 4, characterized in that: The bottom of the sealing unit cavity (31) is provided with an exhaust pump (16) for discharging the gas in the corresponding sealing unit cavity (31) into the outside air, and the exhaust pump (16) is electrically connected to the main controller (33).

6. A ring main unit with AC / DC hybrid and multi-voltage adaptability according to claim 2, characterized in that: A heat exchanger (19) is fixedly installed inside the main sealing cavity (30), and a unit cavity suction pump (26) and a unit cavity return valve (17) are respectively provided at the upper and lower ends of each sealing unit cavity (31). The unit cavity suction pump (26) is connected to the heat source inlet of the heat exchanger (19) and draws nitrogen gas located in the sealing unit cavity (31) into the heat exchanger (19), and the unit cavity return valve (17) is connected to the heat source outlet of the heat exchanger (19) and draws nitrogen gas located in the sealing unit cavity (31) into the heat exchanger (19). The nitrogen gas in the main sealed cavity (30) is sent back to the sealed unit cavity (31). The cold source inlet of the heat exchanger (19) sends the air in the main sealed cavity (30) into the heat exchanger (19) through the air supply pump (20). The cold source outlet of the heat exchanger (19) sends the air in the heat exchanger (19) into the outside air through the second exhaust pipe (18). The main controller (33) is electrically connected to the unit cavity air pump (26), the unit cavity return valve (17) and the air supply pump (20) respectively.

7. A ring main unit with AC / DC hybrid and multi-voltage adaptability according to claim 2, characterized in that: Fixed housings (13) are fixedly installed on the left and right sides of the outer sealing housing (1), and a dust filter (15) is installed at the inlet end of the fixed housing (13). The outlet end of the fixed housing (13) is connected to the inlet end of the pressurized air pump (6). A dust filter device (5) for filtering air is provided inside the fixed housing (13). A first sensor group (4) for detecting the temperature, humidity and air pressure of the air in the main sealing cavity (30) is fixedly installed below the sealing housing (1), and the main controller (33) is electrically connected to the first sensor group (4).

8. A ring main unit with AC / DC hybrid and multi-voltage adaptability according to claim 7, characterized in that: The dust filter device (5) is one or more of the following: dust collector bag, electrostatic precipitator or activated carbon filter packing. The outer side of the fixed housing (13) is provided with a rain cover (14) to prevent rainwater from entering the dust filter (15).

9. A ring main unit with AC / DC hybrid and multi-voltage adaptability according to claim 7, characterized in that: The end of the pressurized air pump (6) is connected to a ceramic heat insulation tube (9), and the interior of the ceramic heat insulation tube (9) is filled with a moisture-absorbing filler (7). The moisture-absorbing filler (7) is one or more of sponge, silica gel or molecular sieve. A heater (8) for heating and drying the moisture-absorbing filler (7) is installed on the ceramic heat insulation tube (9), and a second temperature sensor (10) for detecting the temperature of the moisture-absorbing filler (7) is fixedly installed on the ceramic heat insulation tube (9). The end of the ceramic heat insulation tube (9) is connected to the air distribution pipe (3) and the first exhaust pipe (12) respectively through a reversing solenoid valve (11). The first exhaust pipe (12) is used to discharge the air in the ceramic heat insulation tube (9) to the outside air, and the air distribution pipe (3) is used to send air into the main heat source located in the main sealing cavity (30) through at least three pairs of hoses connected to the end.

Images