Protection device and method for high-voltage circuit breaker of pumped storage power station

Abstract

A protection device and method for a high-voltage circuit breaker of a pumped storage power station mainly comprises a protection box and the high-voltage circuit breaker, the high-voltage circuit breaker is installed in the protection box, a supporting mechanism is installed behind the protection box, and the supporting mechanism freely penetrates through the protection box and fixes the high-voltage circuit breaker; a lead screw mechanism is arranged between the protection box and the supporting mechanism. The lead screw mechanism drives the protection box to move back and forth relative to the high-voltage circuit breaker. A first heat dissipation mechanism and a second heat dissipation mechanism are installed in the protection box, and the first heat dissipation mechanism and the second heat dissipation mechanism are both used for heat dissipation of the high-voltage circuit breaker; a drying mechanism is installed between the first heat dissipation mechanism and the second heat dissipation mechanism and used for drying air entering the protection box. According to the protection device and method for the high-voltage circuit breaker of the pumped storage power station, heat dissipation and moisture removal are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of circuit breakers, and in particular to a protective device and method for a high-voltage circuit breaker in a pumped storage power station. Background Technology

[0002] High-voltage circuit breakers (or high-voltage switches) are safety switches that shut off power to provide safety through the neutral section of overhead lines during lightning strikes. They not only interrupt or close no-load and load currents in high-voltage circuits, but also, through relay protection devices, interrupt overload and short-circuit currents when system faults occur. They possess a sophisticated arc-extinguishing structure and sufficient breaking capacity, and can be categorized as follows: oil circuit breakers (multi-oil circuit breakers, low-oil circuit breakers), sulfur hexafluoride (SF6) circuit breakers, compressed air circuit breakers, vacuum circuit breakers, etc.

[0003] A search revealed that Chinese patent number CN112216565A discloses a high-voltage circuit breaker protection device based on the power internet, belonging to the field of circuit breaker protection. The device includes a protective box, with a sealing mechanism on the top of the protective box and a first shock-absorbing plate fixedly connected to the bottom inner surface of the protective box. By setting up the sealing mechanism, a placement plate, a clamping mechanism, a circular through hole, and a wire mesh, the high-voltage circuit breaker body is placed on the placement plate and fixed by the clamping mechanism.

[0004] The aforementioned public documents describe the protection of high-voltage circuit breakers by installing the circuit breaker body inside a protective enclosure. However, high-voltage circuit breakers inevitably generate heat during operation, so the protective enclosure must also have a heat dissipation function. The circular through-hole at the bottom of the protective enclosure is designed to allow normal air circulation inside. However, this also presents a problem: the air inside and outside the protective enclosure circulates without obstruction. Therefore, when the external air is too humid, such as in scenarios where high-voltage circuit breakers are used in pumped storage power stations, water droplets can easily adhere to the circuit breaker. In severe cases, this can even lead to malfunctions. Furthermore, the circuit breaker cannot prevent moisture during heat dissipation, resulting in low safety. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a protective device and method for a high-voltage circuit breaker in a pumped storage power station, which can achieve moisture protection and heat dissipation.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A protective device for a high-voltage circuit breaker in a pumped-storage power station includes a protective box and a high-voltage circuit breaker, wherein the high-voltage circuit breaker is installed inside the protective box. A support mechanism is installed at the rear of the protective box. The support mechanism can freely pass through the protective box and fix the high-voltage circuit breaker. A screw mechanism is provided between the protective box and the support mechanism. The screw mechanism drives the protective box to move back and forth relative to the high-voltage circuit breaker. The protective box is equipped with a first heat dissipation mechanism and a second heat dissipation mechanism, both of which are used for heat dissipation of the high-voltage circuit breaker. A drying mechanism is installed between the first and second heat dissipation mechanisms. The drying mechanism is used to dry the air entering the protective box.

[0007] The support mechanism includes a first mounting plate and a second mounting plate, which are connected by a connecting plate. The first mounting plate is located inside the protective box and fixes the high-voltage circuit breaker. The second mounting plate is located at the rear of the protective box and is fixed in a designated position. The connecting plate freely passes through the hole on the protective box and slides with the protective box.

[0008] The first mounting plate is L-shaped and has through holes, the second mounting plate is H-shaped and has mounting holes, and the connecting plates are made of angle steel and are arranged in a rectangular array.

[0009] The lead screw mechanism includes a lead screw that freely passes through a hole in the protective box; the two ends of the lead screw are respectively fixed to a first mounting plate and a second mounting plate; a lead screw motor is fixedly connected to the rear side inside the protective box; the lead screw passes through the lead screw motor and is threadedly connected to a nut inside the rotor of the lead screw motor.

[0010] The first heat dissipation mechanism includes an air inlet pipe, which is fixed to the bottom of the protective box and is connected to the inside of the protective box; a first cooling fan and a first filter plate are fixed inside the air inlet pipe, with the first filter plate located below the first cooling fan; and a right air outlet is provided on one side of the upper part of the protective box.

[0011] The second heat dissipation mechanism includes a sealing cover, which is fixed at the bottom of the protective box and located on one side of the first heat dissipation mechanism. One side of the sealing cover is connected to the upper air duct through the middle air duct, and the upper air duct is fixed at the top of the protective box. The other side of the upper air duct is connected to the fan cover, which is fixed at the left air outlet of the protective box and connected to the left air outlet. A second cooling fan is installed at the bottom opening of the upper air duct.

[0012] The lower end of the sealing cover is connected to the air outlet pipe, the air outlet of the air outlet pipe is located on the side away from the first heat dissipation mechanism, and a second filter plate is installed at the outer end of the air outlet pipe.

[0013] The drying mechanism includes a movable plate located above the first heat dissipation mechanism and penetrating through the sealing cover; a through-hole is provided on one side of the movable plate, and a desiccant box is fixedly connected to the through-hole; an electric push rod is fixedly connected to the bottom of the corresponding protective box; the piston rod end of the electric push rod is fixedly connected to one side of the movable plate.

[0014] A humidity detector is fixedly connected to the bottom of the protective box.

[0015] The protective box has a door hinged to the front, and hydraulic support rods are hinged to both sides inside the protective box. The piston rod end of the hydraulic support rod is hinged to the inside of the door.

[0016] A protection method for a high-voltage circuit breaker in a pumped storage power station includes the following steps: 1) When the high-voltage circuit breaker is operating normally inside the protective box, the humidity detector detects the humidity of the air outside the protective box. When the air humidity is high, the electric push rod will pull the moving plate to the left until the desiccant box on the moving plate is directly above the first heat dissipation mechanism. At this time, the first heat dissipation fan will start. The first heat dissipation fan blows the air outside the protective box into the protective box. The air will be dried by the desiccant box when it enters the protective box. Therefore, the heat dissipation air blown towards the high-voltage circuit breaker is relatively dry. Then the hot air inside the protective box is discharged from the right air outlet. 2) When the humidity detector detects that the humidity of the air outside the protective box is low, the electric push rod pushes the moving plate to the right until the through-hole moves into the sealed cover. At this time, the first cooling fan stops running, and the second cooling fan starts. After the second cooling fan starts, it draws away the hot air inside the protective box, and the cold air outside the protective box enters the protective box through the air inlet pipe and the right air outlet in the first cooling mechanism. When the second cooling fan expels the hot air from the protective box, some of the hot air enters the fan cover and is discharged through the left air outlet, and some of the hot air enters the sealed cover through the middle air pipe. Finally, the hot air passes through the desiccant box and is discharged through the air outlet pipe. When the hot air passes through the desiccant box, it can carry away the moisture absorbed in the desiccant box, thereby drying the desiccant box so that it can be used normally again. 3) When it is necessary to inspect the high-voltage circuit breaker, the box door can be opened, and then the screw motor can be started so that the protective box can move backward along the screw. During this process, the connecting plate will also support the protective box to move backward until the high-voltage circuit breaker extends to the front of the protective box.

[0017] This invention provides a protection device and method for high-voltage circuit breakers in pumped storage power stations, which has the following technical advantages: 1) The high-voltage circuit breaker can be installed inside the protective box through the support mechanism. While not affecting the stability of the high-voltage circuit breaker, it can facilitate the first and second heat dissipation mechanisms to dissipate heat fully. At the same time, when the high-voltage circuit breaker is being maintained, it can extend from inside the protective box to the front of the protective box, avoiding interference from the protective box and affecting the maintenance work of the high-voltage circuit breaker. It is very convenient to use.

[0018] 2) Through the cooperation of the first heat dissipation mechanism, the drying mechanism and the right air outlet, the air entering the protective box can be relatively dry when the air humidity is high. This avoids the problem of a large amount of water mist adhering to the surface of the high voltage circuit breaker due to excessive humidity, and also avoids the problem of high voltage circuit breaker failure caused by water mist or even condensation. The moisture-proof effect is better and the use is safer.

[0019] 3) Through the cooperation of the second heat dissipation mechanism and the left air outlet, when the hot air inside the protective box is extracted, a portion of the hot air can also be blown towards the desiccant box in the drying mechanism, thereby removing the moisture adsorbed in the desiccant box and keeping it dry for subsequent use. There is no need for manual removal or replacement of the desiccant, which can be used continuously and autonomously, making it more convenient to use. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is a schematic diagram of the internal structure of the protective box of the present invention.

[0022] Figure 3 This is a front sectional view of the protective box of the present invention.

[0023] Figure 4 This is a schematic diagram of the second heat dissipation mechanism of the present invention.

[0024] Figure 5 This is a schematic diagram of the drying mechanism of the present invention.

[0025] Figure 6 This is a schematic diagram of the support mechanism of the present invention.

[0026] Figure 7 This is a schematic diagram of the high-voltage circuit breaker extending out of the protective box in this invention.

[0027] In the diagram: 1. Protective box; 2. Box door; 3. Hydraulic rod; 4. Left air outlet; 5. Right air outlet; 6. High-voltage circuit breaker; 7. First mounting plate; 8. Pull rod; 9. Second mounting plate; 10. Connecting plate; 11. Lead screw; 12. Lead screw motor; 13. Corrugated pipe; 14. Air inlet pipe; 15. First cooling fan; 16. First filter plate; 17. Moving plate; 18. Through-hole; 19. Desiccant box; 20. Electric push rod; 21. Sealing cover; 22. Middle air duct; 23. Upper air duct; 24. Air cover; 25. Second cooling fan; 26. Humidity detector; 27. Air outlet pipe; 28. Second filter plate. Detailed Implementation

[0028] like Figure 1-2As shown, a protective device for a high-voltage circuit breaker in a pumped-storage power station includes a protective box 1. A left air outlet 4 and a right air outlet 5 are respectively opened on both sides of the protective box 1, both used for heat dissipation. A support mechanism is installed at the rear of the protective box 1, extending into the interior of the protective box 1. The support mechanism is used to install the high-voltage circuit breaker 6. A screw mechanism is also installed on the support mechanism, driving the protective box 1 to move back and forth, causing the high-voltage circuit breaker 6 to extend or retract relative to the interior of the protective box 1.

[0029] like Figure 6 As shown, the support mechanism includes a first mounting plate 7 and a second mounting plate 9. The first mounting plate 7 is located inside the protective box 1 and has an L-shaped structure. The high-voltage circuit breaker 6 is fixedly mounted on the horizontal part of the first mounting plate 7. The second mounting plate 9 is located behind the protective box 1 and is H-shaped. The second mounting plate 9 has multiple bolt holes, and bolts are used to fix the second mounting plate 9 in a designated position. Four connecting plates 10 are fixedly connected between the first mounting plate 7 and the second mounting plate 9, serving as support and guide components.

[0030] The connecting plate 10 is made of angle steel. Since angle steel has better multi-directional resistance to deformation, it avoids the problem of the support mechanism bending and tilting due to wind and other issues.

[0031] An L-shaped hole adapted to the connecting plate 10 is provided on the rear side of the protective box 1. The protective box 1 and the connecting plate 10 are slidably connected, and the protective box 1 can move back and forth along the connecting plate 10 without shaking. Four angle steels are distributed in a rectangular array, and the four rectangular connecting plates 10 pass freely through the rear side of the protective box 1, which can provide support for the protective box 1 when it moves.

[0032] like Figure 6 As shown, the lead screw mechanism includes a lead screw 11, which is fixed between the first mounting plate 7 and the second mounting plate 9, and located between the four connecting plates 10. A lead screw motor 12 is fixedly connected to the rear side inside the protective box 1, and the lead screw 11 passes through and is assembled with the lead screw motor 12. The lead screw motor 12 is a through-shaft type lead screw motor. A circular hole is provided on the rear side of the corresponding protective box 1. The lead screw 11 passes through the circular hole of the protective box 1, and the diameter of the circular hole is larger than the diameter of the lead screw 11. In this way, the lead screw 11 passes through the rear side of the protective box 1, avoiding friction interference between the protective box 1 and the threads on the lead screw 11 when the protective box 1 moves back and forth. After the lead screw motor 12 is started, the lead screw motor 12 moves back and forth on the lead screw 11, thereby driving the protective box 1 to move back and forth. When the protective box 1 moves backward, the high-voltage circuit breaker 6 can be extended to the front side of the protective box 1 to facilitate maintenance of the high-voltage circuit breaker 6.

[0033] Preferably, the first mounting plate 7 has multiple ventilation holes, which is beneficial for heat dissipation.

[0034] like Figure 6 As shown, preferably, two tie rods 8 are fixedly connected to the inner side of the bend of the first mounting plate 7, with the high-voltage circuit breaker 6 located between the two tie rods 8. The tie rods 8 can improve the stability of the first mounting plate 7 and avoid the problem of deformation of the first mounting plate 7 due to the weight of the high-voltage circuit breaker 6.

[0035] like Figure 1 As shown, preferably, both the connecting plate 10 and the lead screw 11 are fitted with corrugated pipes 13, and the two ends of the corrugated pipes 13 are fixedly connected to the rear side of the protective box 1 and the front side of the second mounting plate 9, respectively. Due to the structural characteristics of the corrugated pipes 13, they can retract when the protective box 1 moves backward and unfold on their own when the protective box 1 moves forward, without interfering with the movement of the protective box 1.

[0036] Meanwhile, the corrugated pipe 13 also has the following advantages: 1) The corrugated pipe 13 can protect the L-shaped hole and the round hole on the rear side of the protective box 1, so that even if it rains, rainwater will not enter the interior of the protective box 1 through the L-shaped hole and the round hole. 2) The corrugated pipe 13 can also wrap the connecting plate 10 and the lead rod 11 inside, preventing bird droppings and other foreign objects from falling on them and affecting the movement of the protective box 1.

[0037] like Figures 1-2 , Figure 7 As shown, preferably, a door 2 is hinged to the front of the protective box 1, and hydraulic support rods 3 are hinged to both sides inside the protective box 1. The piston rod end of the hydraulic support rod 3 is hinged to the inner side of the door 2. The hydraulic support rods 3 can open and support the door 2; at the same time, when the door 2 is closed, the interior of the protective box 1 is sealed. The protective box 1 and the door 2 can protect the high-voltage circuit breaker 6 from rain, bird droppings, bird nesting, and other problems.

[0038] Preferably, the protective box 1 is equipped with a first heat dissipation mechanism and a second heat dissipation mechanism, both of which are used to dissipate heat from the high-voltage circuit breaker 6.

[0039] The first heat dissipation mechanism includes an air inlet pipe 14, which is fixedly connected to the bottom of the protective box 1 and is connected to the interior of the protective box 1. A first cooling fan 15 and a first filter plate 16 are fixedly connected inside the air inlet pipe 14, with the first filter plate 16 located below the first cooling fan 15.

[0040] like Figure 3 As shown, the first cooling fan 15 can actively blow outside air into the protective box 1 to cool the high voltage circuit breaker 6. Then the hot air can be discharged through the right air outlet 5. The first filter plate 16 prevents mosquitoes and other insects from flying into the air inlet pipe 14.

[0041] like Figures 3-4 As shown, the second heat dissipation mechanism includes a sealing cover 21, which is fixed to the bottom of the protective box 1. The sealing cover 21 is located on one side above the first heat dissipation mechanism. An upper air duct 23 is fixedly connected to the top of the protective box 1. An intermediate air duct 22 is fixedly connected between the upper air duct 23 and the sealing cover 21. A fan cover 24 is fixedly connected to the side of the upper air duct 23 away from the intermediate air duct 22. The fan cover 24 is fixed to one side inside the protective box 1. The left air outlet 4 is connected to the inside of the fan cover 24. A second heat dissipation fan 25 is embedded in the bottom of the upper air duct 23.

[0042] The second cooling fan 25 can draw away the hot air inside the protective cover 1 and exhaust it through the left air outlet 4, while some of the hot air will be diverted to the inside of the sealing cover 21 through the L-shaped air duct 22.

[0043] Preferably, an air outlet pipe 27 is installed at the bottom of the protective box 1 and directly below the sealing cover 21. The air outlet pipe 27 is in communication with the sealing cover 21. The air outlet of the air outlet pipe 27 is located on the side away from the first heat dissipation mechanism, and a second filter plate 28 is fixedly connected to the air outlet of the air outlet pipe 27.

[0044] The air outlet 27 can divert the hot air from the second heat dissipation mechanism to dry the desiccant box 19. The direction of the air outlet of the air outlet 27 can also prevent the hot air from being quickly discharged back into the protective box 1 through the air inlet 14. The second filter plate 28 can prevent birds, bees, etc. from entering the air outlet 27 to build nests.

[0045] Preferably, a drying mechanism is installed at the bottom of the protective box 1. The drying mechanism is installed between the first heat dissipation mechanism and the second heat dissipation mechanism. The drying mechanism is used to dry the air entering the protective box 1.

[0046] like Figure 3 , Figure 5 As shown, the drying mechanism includes a movable plate 17, which is located above the first heat dissipation mechanism and penetrates the sealing cover 21. A through-hole 18 is provided at the top of the movable plate 17, and a desiccant box 19 is fixedly connected inside the through-hole 18. An electric push rod 20 is fixedly connected to the bottom of the protective box 1. The piston rod end of the electric push rod 20 is fixedly connected to one side of the movable plate 17, and the electric push rod 20 is located on the other side above the first heat dissipation mechanism.

[0047] When the first heat dissipation mechanism is running, the electric push rod 20 in the drying mechanism pulls the moving plate 17 to the left, moving the desiccant box 19 directly above the air inlet pipe 14 to dry the air blown into the protective box 1 by the first cooling fan 15. When the second heat dissipation mechanism is running, the electric push rod 20 in the drying mechanism pushes the moving plate 17 to the right, moving the desiccant box 19 into the sealing cover 21. At this time, the hot air diverted from the second heat dissipation mechanism blows onto the desiccant box 19 to dry it again for subsequent use. Regardless of whether the moving plate 17 moves to the left or right, the moving plate 17 and the sealing cover 21 are sealed. Therefore, air inside the protective box 1 will not be directly discharged from the gaps in the sealing cover 21, and hot air inside the sealing cover 21 will not return to the protective box 1 through the gaps. The desiccant box 19 can be composed of a filter cage and desiccant filled inside.

[0048] like Figure 3 As shown, preferably, a humidity detector 26 is fixedly connected to the bottom of the protective box 1. The humidity detector 26 is used to detect the air humidity. Then, based on the air humidity, it is determined whether to use the first heat dissipation mechanism or the second heat dissipation mechanism.

[0049] Preferably, the protective device has a built-in control box (not shown in the figure), which contains a controller, power supply, etc. The temperature and humidity detector 26, the lead screw motor 12, the first cooling fan 15, and the second cooling fan 25 are all electrically connected to the controller, and the controller controls the orderly operation of each drive device.

[0050] Working principle and process: 1) When the high-voltage circuit breaker 6 is operating normally inside the protective box 1, the humidity detector 26 will detect the humidity of the air outside the protective box 1. When the air humidity is high, the electric push rod 20 will pull the moving plate 17 to the left until the desiccant box 19 on the moving plate 17 is directly above the first heat dissipation mechanism. At this time, the first heat dissipation fan 15 will run and blow the air outside the protective box 1 into the protective box 1. The air will be dried by the desiccant box 19 when it enters the protective box 1. Therefore, the heat dissipation air blown towards the high-voltage circuit breaker 6 is relatively dry. Then the hot air inside the protective box 1 will be discharged from the right air outlet 5.

[0051] 2) When the humidity detector 26 detects that the external air humidity of the protective box 1 is low, the electric push rod 20 can push the moving plate 17 to the right until the through-hole 18 moves with the moving plate 17 into the sealing cover 21. At this time, the first cooling fan 15 stops running, and the second cooling fan 25 starts. After the second cooling fan 25 starts, it draws away the hot air inside the protective box 1, and the cold air outside the protective box 1 can enter the protective box 1 through the air inlet pipe 14 and the right air outlet 5 in the first heat dissipation mechanism. When the second cooling fan 25 exhausts the hot air in the protective box 1, part of the hot air enters the fan cover 24 and is exhausted through the left air outlet 4, and part of the hot air enters the sealing cover 21 through the middle air pipe 22. Finally, the hot air passes through the desiccant box 19 and is exhausted through the air outlet pipe 27. When the hot air passes through the desiccant box 19, it can take away the moisture absorbed in the desiccant box 19, thereby drying the desiccant box 19 so that it can be used normally again.

[0052] 3) When it is necessary to inspect the high voltage circuit breaker 6, the box door 2 can be opened, and then the screw motor 12 can be started so that the protective box 1 can move backward along the screw 11. During this time, the connecting plate 10 will also support the protective box 1 so that it can move backward smoothly until the high voltage circuit breaker 6 extends to the front of the protective box 1.

Claims

1. A protective device for a high-voltage circuit breaker in a pumped-storage power station, comprising a protective enclosure (1) and a high-voltage circuit breaker (6), wherein the high-voltage circuit breaker (6) is installed inside the protective enclosure (1), characterized in that: A support mechanism is installed at the rear of the protective box (1). The support mechanism can freely pass through the protective box (1) and fix the high voltage circuit breaker (6). A screw mechanism is provided between the protective box (1) and the support mechanism. The screw mechanism drives the protective box (1) to move back and forth relative to the high voltage circuit breaker (6). The protective box (1) is equipped with a first heat dissipation mechanism and a second heat dissipation mechanism. Both the first heat dissipation mechanism and the second heat dissipation mechanism are used for heat dissipation of the high voltage circuit breaker (6). A drying mechanism is installed between the first heat dissipation mechanism and the second heat dissipation mechanism. The drying mechanism is used to dry the air entering the protective box (1).

2. The protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 1, characterized in that: The support mechanism includes a first mounting plate (7) and a second mounting plate (9), which are connected by a connecting plate (10). The first mounting plate (7) is located inside the protective box (1) and is fixed to the high-voltage circuit breaker (6). The second mounting plate (9) is located behind the protective box (1) and is fixed in a designated position. The connecting plate (10) freely passes through the hole on the protective box (1) and slides with the protective box (1).

3. The protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 2, characterized in that: The first mounting plate (7) is L-shaped and has through holes, the second mounting plate (9) is H-shaped and has mounting holes, and the connecting plate (10) is made of angle steel and is distributed in a rectangular array.

4. The protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 3, characterized in that: The lead screw mechanism includes a lead screw (11), which freely passes through a hole in the protective box (1); the two ends of the lead screw (11) are respectively fixed on the first mounting plate (7) and the second mounting plate (9); a lead screw motor (12) is fixedly connected to the rear side inside the protective box (1); the lead screw (11) passes through the lead screw motor (12) and is threadedly connected to the nut inside the rotor of the lead screw motor (12).

5. The protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 4, characterized in that: The first heat dissipation mechanism includes an air inlet pipe (14), which is fixed at the bottom of the protective box (1) and connected to the inside of the protective box (1); a first heat dissipation fan (15) and a first filter plate (16) are fixed inside the air inlet pipe (14), and the first filter plate (16) is located below the first heat dissipation fan (15); a right air outlet (5) is provided on one side of the upper part of the protective box (1).

6. The protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 5, characterized in that: The second heat dissipation mechanism includes a sealing cover (21), which is fixed to the bottom of the protective box (1) and located on one side of the first heat dissipation mechanism. One side of the sealing cover (21) is connected to the upper air pipe (23) through the middle air pipe (22), and the upper air pipe (23) is fixed to the top of the protective box (1). The other side of the upper air pipe (23) is connected to the fan cover (24), and the fan cover (24) is fixed at the left air outlet (4) of the protective box (1) and connected to the left air outlet (4). A second heat dissipation fan (25) is installed at the bottom opening of the upper air pipe (23). The lower end of the sealing cover (21) is connected to the air outlet pipe (27), and the air outlet of the air outlet pipe (27) is located on the side away from the first heat dissipation mechanism. A second filter plate (28) is installed at the outer end of the air outlet pipe (27).

7. The protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 6, characterized in that: The drying mechanism includes a movable plate (17), which is located above the first heat dissipation mechanism and passes through the sealing cover (21); a through-hole (18) is provided on one side of the movable plate (17), and a desiccant box (19) is fixedly connected to the through-hole (18); an electric push rod (20) is fixedly connected to the bottom of the corresponding protective box (1); the piston rod end of the electric push rod (20) is fixedly connected to one side of the movable plate (17).

8. The protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 7, characterized in that: A humidity detector (26) is fixedly connected to the bottom of the protective box (1).

9. A protective device for a high-voltage circuit breaker in a pumped storage power station according to claim 8, characterized in that: The protective box (1) has a door (2) hinged to the front side. Hydraulic support rods (3) are hinged to both sides inside the protective box (1). The piston rod end of the hydraulic support rod (3) is hinged to the inside of the door (2).

10. A method for protecting a high-voltage circuit breaker in a pumped storage power station according to claim 9, characterized in that: Includes the following steps: 1) When the high-voltage circuit breaker (6) is operating normally inside the protective box (1), the humidity detector (26) detects the humidity of the air outside the protective box (1). When the air humidity is high, the electric push rod (20) will pull the moving plate (17) to the left until the desiccant box (19) on the moving plate (17) is directly above the first heat dissipation mechanism. At this time, the first heat dissipation fan (15) runs. The first heat dissipation fan (15) blows the air outside the protective box (1) into the protective box (1). The air will be dried by the desiccant box (19) when it enters the protective box (1). Therefore, the heat dissipation air blown towards the high-voltage circuit breaker (6) is relatively dry. Then the hot air inside the protective box (1) is discharged from the right air outlet (5). 2) When the humidity detector (26) detects that the humidity of the air outside the protective box (1) is low, the electric push rod (20) pushes the moving plate (17) to the right until the through-hole (18) moves with the moving plate (17) into the sealing cover (21). At this time, the first cooling fan (15) stops running, while the second cooling fan (25) starts. After the second cooling fan (25) starts, it draws away the hot air inside the protective box (1), and the cold air outside the protective box (1) enters through the air inlet pipe (14) and the right air outlet (5) in the first heat dissipation mechanism. Inside the protective box (1), when the second heat dissipation fan (25) exhausts the hot air in the protective box (1), part of the hot air enters the fan cover (24) and is discharged through the left air outlet (4), while part of the hot air enters the sealed cover (21) through the middle air duct (22). Finally, the hot air passes through the desiccant box (19) and is discharged through the air outlet (27). When the hot air passes through the desiccant box (19), it can remove the moisture adsorbed in the desiccant box (19), thereby drying the desiccant box (19) so that it can be used normally again. 3) When it is necessary to inspect the high voltage circuit breaker (6), the box door (2) can be opened, and then the screw motor (12) can be started so that the protective box (1) can move backward along the screw (11). During this period, the connecting plate (10) will also support the protective box (1) to move backward until the high voltage circuit breaker (6) extends to the front of the protective box (1).

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