A high-voltage vacuum circuit breaker with pressure self-compensation

Abstract

The application discloses a kind of pressure self-compensating high-voltage vacuum circuit breaker, belongs to vacuum circuit breaker technical field, including jar body and vacuum arc-extinguishing chamber, vacuum arc-extinguishing chamber is fixedly installed in jar body by installation structure, the end of jar body is equipped with end cover, the outer end of movable conducting rod of vacuum arc-extinguishing chamber is fixedly installed with pull rod assembly, the inside of end cover is fixedly installed with volume adjusting assembly, the present application adopts pressure compensation structure, without being sealed in low pressure gas chamber for relieving the pressure that bellows is subjected to bellows, thus avoid using complex double gas chamber structure, avoid high pressure gas chamber to low pressure bellows air leakage risk, improve circuit breaker safety reliability;At the same time, without lengthening the length of insulation pull rod, avoid occupying too much space, reduce the bending and deformation of insulation pull rod, improve the switching precision of high-voltage vacuum circuit breaker.

Description

Technical Field

[0001] This invention belongs to the field of vacuum circuit breaker technology, and specifically provides a pressure self-compensating high-voltage vacuum circuit breaker. Background Technology

[0002] High-voltage vacuum circuit breakers are critical protection and control devices in power systems. To ensure sufficient insulation strength, their tanks are typically filled with high-voltage insulating gas at 0.4 MPa to 0.7 MPa, while the vacuum interrupter chamber remains under vacuum. This significant pressure difference exerts a continuous inward pressure on the bellows connecting the moving conductor. During circuit breaker tripping operations, the operating mechanism must not only provide the force required for the moving conductor's movement but also overcome this additional pressure on the bellows, directly leading to increased power loss in the operating mechanism.

[0003] Currently, there are two solutions for existing high-voltage vacuum circuit breakers: one is to seal the bellows in a low-pressure chamber, independent of the high-pressure circuit breaker, forming a double-chamber structure. However, since the insulation strength of the low-pressure gas is much lower than that of the surrounding high-pressure insulating gas, the length of the insulating rod needs to be increased by 3 to 5 times to prevent excessive concentration of the electric field at the low-pressure area. The length of the insulating rod exceeds 1000mm, which occupies too much space, increases operating power and wear, and is prone to bending or deformation, affecting the accuracy of opening and closing. At the same time, it makes the double-chamber structure complex and there is a risk of air leakage from the high-pressure chamber to the low-pressure bellows. The other solution is to increase the spring force of the spring operating mechanism to overcome the greater pressure on the bellows, but this will lead to excessively fast opening speed, increasing the load and wear of the circuit breaker.

[0004] To overcome the above problems and improve the safety and stability of circuit breakers, developing a pressure-compensated high-voltage vacuum circuit breaker that can operate reliably under high pressure and has a long service life has become an urgent technical problem for engineers in this field. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a pressure-self-compensating high-voltage vacuum circuit breaker.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a pressure self-compensating high-voltage vacuum circuit breaker, comprising a tank and a vacuum interrupter, wherein the vacuum interrupter is fixedly installed in the tank by an installation structure, an end cover is installed at the end of the tank, a pull rod assembly is fixedly installed at the outer end of the moving conductive rod of the vacuum interrupter, and a volume adjustment assembly is fixedly installed inside the end cover;

[0007] The pull rod assembly includes an insulating pull rod, a piston, and an annular protrusion. The piston is fixedly installed on the outer end of the insulating pull rod and passes through the end cap. The annular protrusion is integrally formed on the inner end of the outer wall of the piston. Pressure regulating components are uniformly inserted and assembled on the side wall of the annular protrusion. An installation ring is assembled on the outer wall of the insulating pull rod, and a temperature regulating component is fixedly installed on the outer circumferential surface of the installation ring.

[0008] The temperature regulating component and the pressure regulating component form a pressure compensation structure. The temperature regulating component is used to drive the pressure regulating component to move. The pressure regulating component is used to adjust the effective pressure-bearing area of ​​the annular protrusion. The volume regulating component is used to assist in adjusting the internal volume of the tank.

[0009] Furthermore, the temperature regulating component includes a base bracket, a top bracket, a bimetallic strip, positioning studs, and a moving ring. Multiple base brackets are evenly fixedly installed on the outer wall of the mounting ring. Each base bracket has a V-shaped structure, and a top bracket is fixedly installed on its upper end via positioning studs. Mounting grooves are formed on the inner walls of both the base brackets and the top brackets, and both ends of the bimetallic strip are fitted into these grooves. The moving ring is sleeved around the middle of the bimetallic strip, and a drive rod is fixedly installed on the outer wall of the moving ring. A transmission tube is fixedly installed on the outer end of the drive rod.

[0010] Furthermore, the pressure regulating assembly includes a plate and a driven rod, with the driven rod fixedly installed on the outer end of the plate. A transmission rod is fixedly installed on the surface of the driven rod, and the transmission rod is movably assembled inside the transmission tube. The annular protrusion has uniformly formed grooves on its sidewalls, and slots are formed on the surface of each groove. The plate is inserted into the slot.

[0011] Furthermore, the inner wall of the slot is provided with a guide groove, and a guide block is fixedly installed at the inner end of the insert plate, and the guide block is inserted into the guide groove.

[0012] Furthermore, mounting blocks are uniformly fixedly installed on the inner wall of the tank, and telescopic rods are fixedly installed on the inner ends of the mounting blocks. A through hole is opened at the lower end of the side wall of the telescopic rod, and the transmission pipe passes through the through hole.

[0013] Furthermore, the active layer of the bimetallic sheet is located inside the passive layer, and elongated holes are provided at both ends of the outer surface of the bimetallic sheet, with positioning studs penetrating through the elongated holes.

[0014] Furthermore, reinforcing ribs are fixedly installed on both the upper and lower surfaces of the movable ring.

[0015] Furthermore, the insert plate has a shell structure, the outer end of the insert plate is an arc-shaped surface, and the diameter of the outer end of the insert plate is equal to the diameter of the annular protrusion.

[0016] Furthermore, the volume adjustment assembly includes a box body and an adjustment plate, with the adjustment plate movably assembled inside the box body. An elastic structure is fitted between the adjustment plate and the inner wall of the box body, and a retaining ring is fixedly installed at the outer end of the inner cavity of the box body.

[0017] Furthermore, the elastic structure adopts a spring, and the inner wall of the box body and the surface of the adjustment plate are symmetrically fixedly installed with limit rings, and the elastic structure is located inside the limit rings.

[0018] The beneficial effects of using this invention are:

[0019] This invention employs a pressure compensation structure, eliminating the need to seal the bellows in a low-pressure chamber to alleviate pressure on the bellows. This avoids the use of a complex dual-chamber structure, mitigates the risk of air leakage from the high-pressure chamber to the low-pressure bellows, and improves the safety and reliability of the circuit breaker. At the same time, it eliminates the need to lengthen the insulating tie rod, avoiding excessive space occupation, reducing bending and deformation of the insulating tie rod, and improving the opening and closing accuracy of the high-voltage vacuum circuit breaker.

[0020] This invention, by setting up a pressure compensation structure composed of a temperature regulation component and a pressure regulation component, can automatically respond to pressure fluctuations caused by temperature changes inside the tank. When the temperature changes, it can automatically adjust the effective pressure-bearing area at the piston, thereby adjusting the compensation force to ensure that it cancels out the pressure at the bellows and maintains dynamic balance. This achieves adaptive adjustment to the main sources of interference and improves the accuracy and stability of the pressure compensation structure under variable temperature conditions.

[0021] The present invention incorporates a volume adjustment component, which can effectively absorb pressure disturbances caused by instantaneous factors such as the opening and closing arc effect or long-term trace gas changes. As an auxiliary adjustment unit, it works in conjunction with the pressure compensation structure to jointly ensure the overall stability of the gas pressure inside the tank. Attached Figure Description

[0022] Figure 1 This is a front sectional view of the present invention.

[0023] Figure 2 This is a three-dimensional schematic diagram of the tie rod assembly and pressure compensation structure of the present invention.

[0024] Figure 3 This is a three-dimensional schematic diagram of the pull rod assembly of the present invention.

[0025] Figure 4 This is a cross-sectional view of the annular protrusion of the present invention.

[0026] Figure 5 This is a three-dimensional schematic diagram of the mounting ring and part of the temperature regulation components of the present invention.

[0027] Figure 6 This is a three-dimensional schematic diagram of the temperature regulating component and the pressure regulating component of the present invention.

[0028] Figure 7 This is a three-dimensional schematic diagram of the bimetallic sheet of the present invention.

[0029] Figure 8 This is a cross-sectional view of the volume adjustment component of the present invention.

[0030] The reference numerals in the attached drawings include: 1. Tank body; 11. Mounting block; 12. Telescopic rod; 2. End cap; 3. Vacuum interrupter; 4. Rod assembly; 41. Insulating rod; 42. Piston; 43. Annular protrusion; 44. Groove; 45. Slot; 46. Guide groove; 5. Mounting ring; 6. Temperature regulating assembly; 61. Bottom support; 62. Top support; 63. Bimetallic strip; 64. Positioning stud; 65. Moving ring; 66. Driving rod; 67. Transmission tube; 7. Pressure regulating assembly; 71. Insert plate; 72. Guide block; 73. Driven rod; 74. Transmission rod; 8. Volume regulating assembly; 81. Box body; 82. Adjusting plate; 83. Elastic structure; 84. Retaining ring; 85. Limiting ring. Detailed Implementation

[0031] 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.

[0032] Reference Figures 1 to 8 A pressure-compensated high-voltage vacuum circuit breaker includes a tank body 1 and a vacuum interrupter 3. The vacuum interrupter 3 is fixedly installed inside the tank body 1 by an installation structure. An end cover 2 is installed at the end of the tank body 1. A pull rod assembly 4 is fixedly installed at the outer end of the moving conductive rod of the vacuum interrupter 3. A volume adjustment assembly 8 is fixedly installed inside the end cover 2.

[0033] The tank 1 is filled with insulating gas at a pressure of 0.4 to 0.7 MPa. The vacuum interrupter 3 is in a vacuum, while the outside of the tank 1 is filled with air. Therefore, under the action of pressure difference, the insulating gas will exert inward pressure on the bellows in the vacuum interrupter 3 and outward pressure on the piston 42 of the pull rod assembly 4. By setting the effective pressure-bearing area at the piston 42, the two pressures can be canceled out to achieve pressure self-compensation. During the operation of the vacuum interrupter disconnection, there is no need to apply greater force to overcome the reverse pressure on the bellows, which reduces losses and reduces the operating power of the mechanism.

[0034] like Figure 2 and Figure 3As shown, the pull rod assembly 4 includes an insulating pull rod 41, a piston 42, and an annular protrusion 43. The piston 42 is fixedly installed on the outer end of the insulating pull rod 41 and passes through the end cap 2. The annular protrusion 43 is integrally formed on the inner end of the outer wall of the piston 42. Pressure regulating components 7 are evenly inserted and assembled on the side wall of the annular protrusion 43. An installation ring 5 is assembled on the outer wall of the insulating pull rod 41. A temperature regulating component 6 is fixedly installed on the outer circumferential surface of the installation ring 5.

[0035] The mounting ring 5 can be fixedly mounted on the insulating tie rod 41, or it can be set to be movable on the insulating tie rod 41. When it is set to be movable, a limiting structure needs to be set on the insulating tie rod 41.

[0036] Temperature regulating component 6 and pressure regulating component 7 form a pressure compensation structure. Temperature regulating component 6 is used to drive pressure regulating component 7 to move. Pressure regulating component 7 is used to adjust the effective pressure bearing area of ​​the annular protrusion 43. Volume regulating component 8 is used to assist in adjusting the internal volume of tank 1.

[0037] The pressure inside tank 1 is affected by factors such as temperature, the arc effect of the opening and closing operation, and gas decomposition and adsorption during long-term operation. Among these factors, temperature has a greater impact on gas pressure, and the gas pressure changes significantly under temperature changes. The arc effect of the opening and closing operation is an instantaneous effect, a brief dynamic disturbance. Gas decomposition and adsorption during long-term operation produce minute changes, and are a slow, long-term process.

[0038] To address the aforementioned factors, when the temperature changes, the effective pressure-bearing area of ​​the annular protrusion 43 is adjusted by the temperature regulating component 6 and the pressure regulating component 7, ensuring that the pressure at the piston 42 is always equal to the pressure at the bellows in the vacuum interrupter 3. The arc effect during the opening and closing operation, as well as the factors of gas decomposition and adsorption during long-term operation, are mainly adaptively adjusted by the volume regulating component 8 to maintain a constant gas pressure inside the tank 1.

[0039] Specifically, such as Figures 5 to 7 As shown, the temperature regulating component 6 includes a base bracket 61, a top bracket 62, a bimetallic strip 63, a positioning stud 64, and a moving ring 65. Multiple base brackets 61 are evenly fixedly installed on the outer wall of the mounting ring 5. The base brackets 61 have a V-shaped structure, and the top brackets 62 are fixedly installed on the upper ends of the base brackets 61 through the positioning studs 64. The inner walls of the base brackets 61 and the inner walls of the top brackets 62 are provided with mounting grooves, and the two ends of the bimetallic strip 63 are assembled in the mounting grooves. The moving ring 65 is sleeved in the middle of the bimetallic strip 63. An active rod 66 is fixedly installed on the outer wall of the moving ring 65, and a transmission tube 67 is fixedly installed on the outer end of the active rod 66. The active layer of the bimetallic strip 63 is located inside the passive layer. Both ends of the outer surface of the bimetallic strip 63 are provided with elongated holes, and the positioning studs 64 penetrate through the elongated holes. Reinforcing ribs are fixedly installed on the upper and lower surfaces of the moving ring 65.

[0040] The bottom bracket 61 and the top bracket 62 are used to fix the bimetallic strip 63. In this embodiment, a total of six sets of bottom brackets 61 are provided. Therefore, the included angle between the two side plates of each bottom bracket 61 is 30°, ensuring that the adjacent side plates on the two bottom brackets 61 are parallel. This ensures that the bimetallic strip 63 can be installed perpendicular to the radial direction of the mounting ring 5. When the temperature changes, the deformation of the bimetallic strip 63 can drive the moving ring 65 to move in the radial direction relative to the mounting ring 5, thereby driving the insertion plate 71 to move in the slot 45.

[0041] In this embodiment, five bimetallic strips 63 are installed between adjacent base supports 61. The arrangement of multiple bimetallic strips 63 can enhance the thrust or pull generated by their deformation, thereby effectively driving the insert plate 71 to move after transmission.

[0042] By setting the active and passive layers of the bimetallic strip 63, its center gradually bulges up when the temperature rises, causing the insert plate 71 to gradually move outward. As the temperature rises, the air pressure increases, and the bellows will bear greater pressure. Therefore, the insertion plate 71 moves outward through the transmission, which increases the effective pressure-bearing area, thereby increasing the pressure on the piston 42 and the annular protrusion 43, ensuring that the two pressures are always equal. When the temperature drops, the center of the bimetallic strip 63 will be concave, thereby causing the insert plate 71 to move inward. The purpose is also to ensure that the pressure on the bellows, piston 42, and annular protrusion 43 is equal, achieving dynamic balance of pressure in response to temperature changes.

[0043] Specifically, such as Figure 4 and Figure 6 As shown, the pressure regulating assembly 7 includes a plate 71 and a driven rod 73. The driven rod 73 is fixedly installed on the outer end of the plate 71. A transmission rod 74 is fixedly installed on the surface of the driven rod 73 and is movably assembled in the transmission tube 67. The sidewall of the annular protrusion 43 is uniformly provided with grooves 44, and the surface of each groove 44 is provided with slots 45. The plate 71 is inserted into the slot 45. The inner wall of the slot 45 is provided with a guide groove 46. A guide block 72 is fixedly installed on the inner end of the plate 71 and is inserted into the guide groove 46. The plate 71 has a shell structure, the outer end of the plate 71 is an arc-shaped surface, and the diameter of the outer end of the plate 71 is equal to the diameter of the annular protrusion 43.

[0044] In this embodiment, there are six grooves 44, which match the structure of the temperature regulating component 6 and the pressure regulating component 7. In practical applications, their number can be adjusted.

[0045] In this embodiment, the two side walls of the insert plate 71 are parallel. Therefore, when the insert plate 71 moves within the slot 45, the change in the effective pressure-bearing area is linear, which can effectively adjust the pressure and is applicable to situations with small temperature changes. In addition, for different application scenarios, the shapes of the groove 44 and the insert plate 71 can be adjusted to change their area change rate or make their area change non-linear, which is suitable for different temperature ranges and different deformations of the bimetallic strip 63, achieving targeted application.

[0046] In the initial state, the outer wall of the insert plate 71 and the outer peripheral surface of the annular protrusion 43 are on the same cylindrical surface, wherein there is a gap between the inner end of the insert plate 71 and the slot 45 so that the insert plate 71 can move inward when the temperature decreases; the insert plate 71 adopts a hollow design, which greatly reduces the weight, allowing the deformation of the bimetallic strip 63 to drive its movement.

[0047] During the opening process, the moving conductive rod of the vacuum interrupter 3 needs to be moved outward by the pull rod assembly 4. Therefore, the pressure regulating assembly 7 will move accordingly. By setting the transmission rod 74 and the transmission pipe 67 in cooperation, the movement of the pressure regulating assembly 7 will not affect the state of the temperature regulating assembly 6. Therefore, in the case of axial movement, the temperature regulating assembly 6 and the pressure regulating assembly 7 do not interfere with each other, avoiding the situation where the position of the bimetallic strip 63, the insert plate 71 and other structures is offset due to the tension when they are connected. This ensures that deformation and displacement can be accurately transmitted when the temperature changes, and ensures the accuracy of the dynamic pressure balance.

[0048] Specifically, such as Figure 1 and Figure 2 As shown, mounting blocks 11 are uniformly fixedly installed on the inner wall of the tank body 1, and telescopic rods 12 are fixedly installed on the inner ends of the mounting blocks 11. The lower end of the side wall of the telescopic rod is provided with a through hole, and the transmission pipe 67 passes through the through hole.

[0049] The telescopic rod 12 is provided to support the transmission tube 67 and the transmission rod 74, while not restricting the movement of the temperature regulating component 6 and the pressure regulating component 7. The telescopic rod 12 can extend and retract to change its length, so it will not affect the deformation and displacement transmission of the bimetallic strip 63.

[0050] When the temperature rises, the adjustment process is as follows: the bimetallic strip 63 deforms when heated, and its middle part bulges outward, driving the moving ring 65 to move outward. Then, through the transmission of the driving rod 66, the transmission tube 67, the transmission rod 74, and the driven rod 73 in sequence, the insert plate 71 moves outward. Conversely, when the temperature drops, the adjustment process is reversed. The middle part of the bimetallic strip 63 is concave, which eventually drives the insert plate 71 to move inward.

[0051] Specifically, such as Figure 8As shown, the volume adjustment assembly 8 includes a box body 81 and an adjustment plate 82, and the adjustment plate 82 is movably assembled inside the box body 81. An elastic structure 83 is assembled between the adjustment plate 82 and the inner wall of the box body 81, and a retaining ring 84 is fixedly installed at the outer end of the inner cavity of the box body 81.

[0052] A sealing structure is provided between the adjusting plate 82 and the box body 81, which can be a sealing ring.

[0053] The sealed cavity formed by the box body 81 and the regulating plate 82 can be set to a vacuum or to air. The elastic structure 83 applies a supporting force to the regulating plate 82. The supporting force is equal to the pressure generated by the air pressure difference on the regulating plate 82. Therefore, when the arc effect of the opening and closing operation or the decomposition and adsorption of gas during long-term operation occur, the volume regulating component 8 will drive the regulating plate 82 to move accordingly according to the air pressure change, so as to fine adjust the internal volume of the tank body 1 and keep the air pressure stable by adjusting the volume.

[0054] The volume of the box 81 is very small compared to that of the tank 1. Therefore, the adjustment of the volume regulating component 8 has little effect on the adjustment of the temperature regulating component 6 and the pressure regulating component 7 due to the change in air pressure caused by temperature changes, and can be ignored.

[0055] Specifically, the elastic structure 83 uses a spring, and the inner wall of the box 81 and the surface of the adjusting plate 82 are symmetrically fixed with a limiting ring 85, and the elastic structure 83 is located inside the limiting ring 85.

[0056] When the elastic structure 83 is a spring, a limiting ring 85 is provided to limit its position in order to provide a stable spring force.

[0057] In addition, the elastic structure 83 can also be made of cylinder or hydraulic cylinder, which provides sufficient force while also facilitating fine adjustment.

[0058] As a passive, high-response fine-tuning unit, the volume regulating component 8 mainly functions to quickly absorb instantaneous pressure pulses caused by opening and closing arcs, or to slowly compensate for minute changes in the gas medium during long-term operation.

[0059] The above content is only a preferred embodiment of the present invention. For those skilled in the art, many changes can be made in the specific implementation and application scope based on the concept of the present invention. As long as these changes do not depart from the concept of the present invention, they all fall within the protection scope of the present invention.

Claims

1. A pressure-self-compensating high-voltage vacuum circuit breaker, characterized in that: It includes a tank body and a vacuum interrupter chamber. The vacuum interrupter chamber is fixedly installed in the tank body by an installation structure. An end cover is installed at the end of the tank body. A pull rod assembly is fixedly installed at the outer end of the moving conductive rod of the vacuum interrupter chamber. A volume adjustment assembly is fixedly installed inside the end cover. The pull rod assembly includes an insulating pull rod, a piston, and an annular protrusion. The piston is fixedly installed on the outer end of the insulating pull rod and passes through the end cap. The annular protrusion is integrally formed on the inner end of the outer wall of the piston. Pressure regulating components are uniformly inserted and assembled on the side wall of the annular protrusion. An installation ring is assembled on the outer wall of the insulating pull rod, and a temperature regulating component is fixedly installed on the outer circumferential surface of the installation ring. The temperature regulating component and the pressure regulating component form a pressure compensation structure. The temperature regulating component is used to drive the pressure regulating component to move. The pressure regulating component is used to adjust the effective pressure-bearing area of ​​the annular protrusion. The volume regulating component is used to assist in adjusting the internal volume of the tank.

2. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 1, characterized in that: The temperature regulating assembly includes a base bracket, a top bracket, a bimetallic strip, positioning studs, and a movable ring. Multiple base brackets are evenly fixed to the outer wall of the mounting ring. Each base bracket has a V-shaped structure, and a top bracket is fixedly mounted to its upper end via positioning studs. Mounting grooves are formed on the inner walls of both the base brackets and the top brackets, and both ends of the bimetallic strip are fitted into these grooves. The movable ring is fitted around the middle of the bimetallic strip. A drive rod is fixedly mounted to the outer wall of the movable ring, and a transmission tube is fixedly mounted to the outer end of the drive rod.

3. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 2, characterized in that: The pressure regulating assembly includes a plate and a driven rod, with the driven rod fixedly installed on the outer end of the plate. A transmission rod is fixedly installed on the surface of the driven rod, and the transmission rod is movably assembled inside the transmission tube. The annular protrusion has grooves evenly distributed on its sidewalls, and slots are formed on the surface of each groove. The plate is inserted into the slot.

4. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 3, characterized in that: The inner wall of the slot is provided with a guide groove, and a guide block is fixedly installed on the inner end of the insert plate, and the guide block is inserted into the guide groove.

5. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 4, characterized in that: The inner wall of the tank is uniformly fixed with mounting blocks, and each mounting block is fixedly installed with a telescopic rod at its inner end. The lower end of the side wall of the telescopic rod is provided with a through hole, and the transmission pipe passes through the through hole.

6. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 2, characterized in that: The active layer of the bimetallic sheet is located inside the passive layer, and elongated holes are provided at both ends of the outer surface of the bimetallic sheet, with positioning studs passing through the elongated holes.

7. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 2, characterized in that: Reinforcing ribs are fixedly installed on both the upper and lower surfaces of the movable ring.

8. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 3, characterized in that: The insert plate has a shell structure, and the outer end of the insert plate is an arc-shaped surface. The diameter of the outer end of the insert plate is equal to the diameter of the annular protrusion.

9. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 1, characterized in that: The volume adjustment assembly includes a box and an adjustment plate, with the adjustment plate movably assembled inside the box. An elastic structure is fitted between the adjustment plate and the inner wall of the box, and a retaining ring is fixedly installed at the outer end of the inner cavity of the box.

10. A pressure-self-compensating high-voltage vacuum circuit breaker according to claim 9, characterized in that: The elastic structure uses a spring, and the inner wall of the box and the surface of the adjustment plate are symmetrically fixed with limit rings, with the elastic structure located inside the limit rings.

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