252kV / 63kA pneumatic GIS circuit breaker structure

Abstract

The invention provides a 252kV / 63kA pneumatic GIS circuit breaker structure, which comprises a middle contact seat, a moving contact assembly, a static contact assembly and a piston seat, and is characterized in that one end, far away from the static contact assembly, of the moving contact assembly penetrates through the piston seat and then is connected with a spring operating mechanism through an insulating pull rod, a piston head is arranged on the piston seat, and the piston head is connected with the static contact assembly; the moving contact assembly comprises a nozzle, a cylinder and a rod fixed in the cylinder, the outer wall of the cylinder is in contact with the middle contact seat, the inner wall of the cylinder is in contact with the piston head, an expansion chamber is formed above the piston head, the piston head is provided with an air hole penetrating in the axial direction of the piston head and an annular valve plate, and when the valve plate is in contact with the top face of the piston head, the valve plate is in contact with the top face of the piston head. The circuit breaker has the beneficial effect that the durability and the reliability of the circuit breaker are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power engineering, and particularly to a structure of a 252 kV / 63 kA puffer-type GIS circuit breaker. Background Art

[0002] With the continuous growth of the global economy, the power system is facing unprecedented challenges. Especially for the 220 kV power grid system, its capacity is constantly climbing and it has become an important part of the modern power network. However, this development trend has also brought new problems, that is, the risk of excessive short-circuit current has increased significantly, posing a huge threat to the stable operation of the power grid. Excessive short-circuit current may not only cause equipment damage, but also lead to large-scale power outages, seriously affecting social production and people's lives.

[0003] To address this challenge, puffer-type GIS circuit breakers are commonly used in the prior art. Its core structure includes a piston head, a valve plate and a pore design. Specifically, a positioning bolt is penetrated through the pore of the piston head of the existing circuit breaker, and the valve plate slides along the axial direction of the positioning bolt to open or close the pore. During the opening process, the valve plate moves along the positioning bolt under the action of air pressure and mechanical driving force to block or open the pore, thereby controlling the flow of gas in the expansion chamber.

[0004] However, the above prior art has at least the following defects: The setting of the positioning bolt will limit the internal space of the pore of the piston head, and the valve plate is prone to friction with the positioning bolt during the sliding process, which not only increases the operating resistance, but also may cause the valve plate to deflect or jam, making it difficult to meet the requirements of modern power grids for high reliability and durability. Summary of the Invention

[0005] Embodiments of the present application provide a structure of a 252 kV / 63 kA puffer-type GIS circuit breaker, aiming to solve the deficiencies in the prior art, improve the durability and reliability of the circuit breaker, and provide a strong guarantee for the stable operation of the power system.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions. A 252kV / 63kA puffer-type GIS circuit breaker structure includes an intermediate contact seat, a moving contact assembly, a static contact assembly, and a piston seat. One end of the moving contact assembly away from the static contact assembly passes through the piston seat and is connected to a spring operating mechanism through an insulating pull rod. A piston head is provided on the piston seat. The moving contact assembly includes a nozzle, a cylinder body, and a rod body fixed inside the cylinder body. The outer wall of the cylinder body contacts the intermediate contact seat, and the inner wall of the cylinder body contacts the piston head and forms an expansion chamber above the piston head. The piston head is provided with an axially penetrating air hole and an annular valve plate. When the valve plate contacts the top surface of the piston head, the air hole of the piston head can be blocked. The gravity-type valve plate structure adopted by the present invention simplifies the opening and closing process of the air hole, reduces the manufacturing cost. At the same time, due to the relatively simple structure, the maintenance difficulty is correspondingly reduced, which is beneficial to extending the service life of the equipment and improving the reliability of the equipment.

[0007] As a further improvement of the above solution, a columnar cavity is provided at the top of the piston head. A retaining ring is embedded on the inner wall of the cavity. The retaining ring is located above the valve plate, and the inner diameter of the retaining ring is smaller than the outer diameter of the valve plate. This can effectively limit the movement range of the valve plate, ensure that the valve plate can accurately and reliably block the air hole of the piston head when needed, while simplifying the structure and improving the overall reliability and durability.

[0008] As a further improvement of the above solution, a sealing ring is provided on the inner wall of the intermediate contact seat. The inner ring of the sealing ring contacts the outer wall of the cylinder body. This can ensure that the high-pressure gas inside the circuit breaker can be smoothly blown out to extinguish the arc during opening, and can also prevent external impurities or moisture from entering the inside of the circuit breaker.

[0009] As a further improvement of the above solution, the static contact assembly includes an arc extinguishing chamber and a static arc contact located inside the arc extinguishing chamber. The nozzle of the moving contact assembly has a throat. The inner diameter of the throat of the nozzle is not less than the diameter of the static arc contact. The inner diameter of the nozzle gradually expands both upward and downward from the throat position. During the opening process, when an arc is formed between the static arc contact and the moving contact assembly, the high-pressure gas can more effectively blow towards the arc through the throat of the nozzle, enhancing the arc blowing effect. At the same time, the gradual expansion of the inner diameter of the nozzle helps to reduce the resistance during gas flow and improve the arc blowing efficiency. In addition, it also helps to prevent the arc from reigniting inside the nozzle, thereby improving the breaking capacity and reliability of the circuit breaker.

[0010] As a further improvement of the above solution, the end of the rod body inside the cylinder body close to the static contact assembly is a hollow structure. The inner diameter of the hollow structure inside the rod body is not less than the diameter of the static arc contact.

[0011] As a further improvement of the above solution, the stroke of the nozzle of the moving contact assembly inside the arc extinguishing chamber is between 180mm and 220mm, and the length of the throat position of the nozzle is between 14mm and 16mm.

[0012] As a further improvement of the above solution, the travel of the nozzle of the moving contact assembly in the arc extinguishing chamber is 200 mm, and the length of the throat position of the nozzle is 15 mm.

[0013] As a further improvement of the above solution, the upper end of the static arc contact is a static arc contact support seat, and the static arc contact support seat is provided with a steel sheath.

[0014] It can be seen from the above technical solutions that the present invention has at least the following technical effects or advantages: The gravity valve plate structure adopted by the present invention simplifies the opening and closing process of the air holes and reduces the manufacturing cost. At the same time, due to the relatively simple structure, the maintenance difficulty is also correspondingly reduced, which is beneficial to extending the service life of the equipment and improving the reliability of the equipment. The moving contact assembly has a nozzle facing the static contact assembly. The nozzle has a throat, and the inner diameter of the nozzle gradually expands upward from the throat position. In this way, during the opening process, when an arc is formed between the static arc contact and the moving contact assembly, the high-pressure gas can more effectively blow towards the arc through the throat of the nozzle, enhancing the arc blowing effect. At the same time, the gradual expansion of the inner diameter of the nozzle helps to reduce the resistance during gas flow and improve the arc blowing efficiency. In addition, it also helps to prevent the arc from reigniting in the nozzle, thereby improving the breaking capacity and reliability of the circuit breaker. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings: Figure 1 Structural schematic diagram of the whole of the present invention (open state); Figure 2 Structural schematic diagram of the whole of the present invention (closed state); Figure 3 Partial enlarged schematic diagram of the present invention; Figure 4 Usage schematic diagram of the present invention.

[0016] Explanation of reference numerals in the drawings: 1, intermediate contact seat; 2, static contact assembly; 3, arc extinguishing chamber; 4, static arc contact; 5, piston seat; 6, piston head; 7, cylinder body; 8, rod body; 9, nozzle; 10, expansion chamber; 11, valve plate; 12, retaining ring. Detailed Embodiments To enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in this patent, other embodiments obtained by those of ordinary skill in the art without creative efforts all fall within the scope of protection of this patent.

[0017] The present invention discloses a structure of a 252 kV / 63 kA puffer-type GIS circuit breaker. As Figures 1 to 4 shown, it includes an intermediate contact base 1, a moving contact assembly, a static contact assembly 2, and a piston base 5. A piston head 6 is provided on the piston base 5. The moving contact assembly includes a cylinder body 7 and a rod body 8 fixed inside the cylinder body 7. Among them, one end of the rod body 8 far from the static contact assembly 2 passes through the piston base 5 and is connected to a spring operating mechanism through an insulating pull rod. The inner wall of the cylinder body 7 contacts the piston head 6 and forms an expansion chamber 10 above the piston head 6. The outer wall of the cylinder body 7 contacts the intermediate contact base 1.

[0018] The static contact assembly 2 includes an arc extinguishing chamber 3 and a static arc contact 4 located inside the arc extinguishing chamber 3. The structure of the static arc contact 4 is a cylinder extending towards the moving contact assembly. The moving contact assembly further includes a nozzle 9 facing the static contact assembly 2. The nozzle 9 has a throat. The inner diameter of the throat of the nozzle 9 is not less than the diameter of the static arc contact 4. The inner diameter of the nozzle 9 gradually expands both upward and downward from the position of the throat. Thus, during the opening process, when the static arc contact 4 is located at the opening of the nozzle 9, the high-pressure gas in the expansion chamber 10 can be quickly blown out, thereby extinguishing the arc.

[0019] The piston head 6 is provided with an axially penetrating air hole and an annular valve plate 11. When the valve plate 11 contacts the top surface of the piston head 6, the air hole of the piston head 6 can be blocked. In addition, a columnar cavity is provided at the top of the piston head 6. A retaining ring 12 is embedded on the inner wall of the cavity. The retaining ring 12 is located above the valve plate 11, and the inner diameter of the retaining ring 12 is smaller than the outer diameter of the valve plate 11. In this way, the position of the valve plate 11 can be restricted within the columnar cavity at the top of the piston head 6 through the retaining ring 12.

[0020] The inner wall of the middle contact base 1 is provided with a sealing ring. The inner ring of the sealing ring contacts the outer wall of the cylinder body 7. During the process of closing or opening, the outer wall of the cylinder body 7 of the moving contact assembly contacts the sealing ring and slides frictionally. The sealing ring can improve the reliability of the moving contact assembly during operation. One end of the rod body 8 of the moving contact assembly close to the static contact assembly 2 is a hollow structure. The inner diameter of the hollow structure in the rod body 8 is not less than the diameter of the static arc contact 4. In this way, when in the closed state, the lower end of the static arc contact 4 can extend into the hollow structure of the rod body 8 after passing through the throat position of the nozzle 9. The other end of the rod body 8 is connected to a spring operating mechanism, and the spring operating mechanism is a CT26 spring operating mechanism, which is prior art and will not be elaborated here.

[0021] The stroke of the nozzle 9 of the moving contact assembly in the arc extinguishing chamber 3 is between 180 mm and 220 mm, preferably 200 mm. The length of the throat position of the nozzle 9 is between 14 mm and 16 mm, preferably 15 mm. This can ensure that the circuit breaker has sufficient arc extinguishing ability during the opening process.

[0022] In addition, a static arc contact support is provided at the upper end of the static arc contact 4, and the static arc contact support is provided with a steel sheath. The provision of the steel sheath can further reduce the risk of shell breakdown caused by ablation metal ions brought by gas blowing.

[0023] The working process of the present invention is as follows: Opening process: Initially, the circuit breaker is in the closed state. At this time, the pressure in the expansion chamber 10 is balanced with the external pressure. The moving contact assembly is connected to the static contact assembly 2, and the circuit is in a conducting state. Since the spring operating mechanism is connected to the rod body 8 of the moving contact assembly through an insulating pull rod, when a opening signal is received, the spring operating mechanism starts to act, driving the moving contact assembly to perform an opening movement. During this process, the valve plate 11 blocks the air hole at the piston head 6 under the dual action of gravity and air pressure. At this time, the static arc contact 4 has not been pulled out of the throat of the nozzle 9. As the moving contact assembly continues to move, the gas in the expansion chamber 10 is compressed, and the pressure in the cylinder gradually increases. When the static arc contact 4 is located at the opening of the nozzle 9, the high-pressure gas in the expansion chamber 10 is quickly blown out, thereby blowing out the arc and achieving successful arc extinction.

[0024] Closing process: In the initial state, the circuit breaker is in the open state, and the pressure in the expansion chamber 10 is balanced with the external pressure. When a closing signal is received, the spring operating mechanism acts, driving the moving contact assembly to perform a closing movement. During this process, as the moving contact assembly moves, the pressure in the expansion chamber 10 gradually decreases, forming a pressure difference with the outside. Under the action of the pressure difference, the valve plate 11 moves to the position of the retaining ring 12, and at this time, the air hole at the piston head 6 opens, and air intake begins. When the moving contact assembly reaches the closing position, the air intake process stops. The valve plate 11 resets to the upper end face of the piston head 6 under the action of gravity, blocking the air hole, and preparing for the next opening.

[0025] It can be seen that the gas-blast GIS circuit breaker disclosed in the present invention realizes efficient and reliable circuit opening and closing operations. At the same time, the gravity-type valve plate structure adopted by it simplifies the opening and closing process of the air hole, reducing the manufacturing cost and maintenance difficulty.

[0026] In the description of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for describing the present invention rather than requiring the present invention to be constructed or operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. The "connected" and "connected" in the present invention should be understood in a broad sense. For example, it can be a connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0027] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in their embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novelties disclosed herein.

Claims

1. A 252kV / 63kA compressed air GIS circuit breaker structure, comprising an intermediate contact seat (1), a moving contact assembly, a stationary contact assembly (2) and a piston seat (5), wherein one end of the moving contact assembly away from the stationary contact assembly (2) passes through the piston seat (5) and is connected to a spring operating mechanism via an insulating pull rod, characterized in that: A piston head (6) is arranged on the piston seat (5), and the moving contact assembly comprises a nozzle (9), a cylinder (7) and a rod (8) fixed in the cylinder (7); the outer wall of the cylinder (7) contacts the intermediate contact seat (1), the inner wall of the cylinder (7) contacts the piston head (6) and forms an expansion chamber (10) above the piston head (6); the piston head (6) is provided with an air hole penetrating along its axial direction and an annular valve plate (11); when the valve plate (11) contacts the top surface of the piston head (6), the air hole of the piston head (6) can be blocked.

2. A 252kV / 63kA compressed air GIS circuit breaker structure according to claim 1, characterized in that: A columnar cavity is provided on the top of the piston head (6), a retaining ring (12) is embedded in the inner wall of the cavity, the retaining ring (12) is located above the valve plate (11), and the inner diameter of the retaining ring (12) is smaller than the outer diameter of the valve plate (11).

3. A 252kV / 63kA compressed air GIS circuit breaker structure according to claim 1, characterized in that: A sealing ring is provided on the inner wall of the middle contact seat (1), and the inner ring of the sealing ring contacts the outer wall of the cylinder (7).

4. A 252kV / 63kA compressed air GIS circuit breaker structure according to claim 1, characterized in that: The stationary contact assembly (2) comprises an arc extinguishing chamber (3) and a stationary arc contact (4) located in the arc extinguishing chamber (3); the nozzle (9) of the moving contact assembly has a throat; the inner diameter of the throat of the nozzle (9) is not less than the diameter of the stationary arc contact (4); and the inner diameter of the nozzle (9) gradually increases upward and downward from the throat position.

5. A 252kV / 63kA compressed air GIS circuit breaker structure according to claim 4, characterized in that: One end of the rod body (8) in the cylinder (7) close to the static contact assembly (2) is a hollow structure, and the inner diameter of the hollow structure in the rod body (8) is not less than the diameter of the static arc contact (4).

6. A 252kV / 63kA compressed air GIS circuit breaker structure according to claim 5, characterized in that: The travel of the nozzle (9) of the moving contact assembly in the arc extinguishing chamber (3) is between 180 mm and 220 mm, and the length of the throat position of the nozzle (9) is between 14 mm and 16 mm.

7. A 252kV / 63kA compressed air GIS circuit breaker structure according to claim 6, characterized in that: The travel of the nozzle (9) of the moving contact assembly in the arc extinguishing chamber (3) is 200 mm, and the length of the throat position of the nozzle (9) is 15 mm.

8. A 252kV / 63kA compressed air GIS circuit breaker structure according to claim 1, characterized in that: The upper end of the static arc contact (4) is a static arc contact support, and the static arc contact support is provided with a steel sheath.

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