Self-energy arc extinguishing device, circuit breaker and electric power system

Abstract

The invention discloses a self-energy arc extinguishing device, a circuit breaker and an electric power system, the self-energy arc extinguishing device comprises an air compression chamber, an expansion chamber, a first nozzle and a moving arc contact, and a piston pull rod is arranged in the air compression chamber; the expansion chamber is connected with the air compression chamber, and the front end of the piston can extend into the expansion chamber to form a boosting air chamber; the first nozzle is arranged at the end, away from the air compression chamber, of the expansion chamber, and an arc generation area is formed in the first nozzle. The moving arc contact is arranged at the front end of the piston, a first channel is arranged in the moving arc contact, one end of the first channel is communicated with the boosting air chamber, the other end of the first channel faces the arc generation area, a first one-way valve is arranged on the circumferential wall of the boosting air chamber, and the first one-way valve is configured to enable the boosting air chamber to be communicated with the expansion chamber in a one-way mode. The self-energy arc extinguishing device can make full use of expansion pressure caused by arc energy, and the voltage building capacity of the expansion chamber is greatly improved.

Description

Technical Field

[0001] The present application relates to the technical field of circuit breaking, and more specifically, to a self-energizing arc extinguishing device, a circuit breaker and a power system. Background Art

[0002] In the power system, in addition to carrying the rated current, the circuit breaker also needs to carry the fault current generated by opening and closing or grounding. In general, the fault current is much greater than the rated current. When a fault current occurs, an arc will be generated. The arc is a gas discharge phenomenon that has certain hazards to electrical appliances, so the circuit breaker needs to be arc extinguished. Self-energized arc extinguishing is a major arc extinguishing method. The self-energized arc extinguishing chamber includes a compressed air chamber and an expansion chamber. The increase in gas pressure in the expansion chamber will spray insulating gas into the arc area, thereby extinguishing the arc. The source of the increase in gas pressure in the expansion chamber includes two aspects. On the one hand, it is the arc energy generated during the breaking process, and on the other hand, it is from the injection of high-pressure gas in the compressed air chamber.

[0003] The pressure of the expansion chamber plays a great role in the breaking capacity of the arc extinguishing chamber. The greater the pressure in the expansion chamber, the better the breaking effect of the arc extinguishing chamber. Therefore, how to establish a higher pressure in the expansion chamber is an important direction of arc extinguishing chamber research. Summary of the invention

[0004] In view of this, the present application provides a self-energy arc extinguishing device, a circuit breaker and a power system to enhance the pressure building capacity of the expansion chamber of the self-energy arc extinguishing device.

[0005] To achieve the above objectives, this application provides the following technical solutions: A self-energizing arc extinguishing device, applied to a circuit breaker, comprising: A compressed air chamber, in which a movable piston and a piston pull rod connected to the piston are arranged, and the piston pull rod is used to drive the piston to move; An expansion chamber, connected to one end of a piston corresponding to the compression chamber, and the front end of the piston can extend into the expansion chamber, and a boost chamber is formed at the front end of the piston; A first nozzle is arranged at one end of the expansion chamber away from the compressed air chamber and has an arc generating area formed therein; A moving arc contact is arranged at the front end of the piston, an injection channel is formed between the moving arc contact and the inner cavity of the first nozzle, a first channel is arranged in the moving arc contact, one end of the first channel is connected to the boosting air chamber, and the other end of the first channel faces the arc generation area; Wherein, a first one-way valve is arranged on the circumferential wall of the boost air chamber, and the first one-way valve is configured to conduct one-way electricity from the boost air chamber to the expansion chamber.

[0006] In some embodiments of the present application, the number of the first one-way valves is one or more; wherein, when the number of the first one-way valves is multiple, the first one-way valves are distributed along the circumferential wall of the pressure boosting air chamber.

[0007] In some embodiments of the present application, a second channel is provided in the piston pull rod, one end of the second channel is connected to the pressure boosting air chamber through a pressure relief valve, and the other end of the second channel communicates with the inner cavity of the breaker housing; Wherein, the pressure relief valve is used to release the pressure of the pressure boosting air chamber into the second channel when the pressure in the pressure boosting air chamber reaches a preset pressure value.

[0008] In some embodiments of the present application, the pressure relief valve is configured as a pressure relief valve with an adjustable preset pressure value.

[0009] In some embodiments of the present application, an adjusting spring is provided on the pressure relief valve, and the adjusting spring is used to control the preset pressure value for the pressure relief valve to act.

[0010] In some embodiments of the present application, the pressure relief valve is provided on the end face where the piston pull rod is connected to the piston.

[0011] In some embodiments of the present application, the self - energy arc extinguishing device further includes a second nozzle disposed outside the moving arc contact, and the inner cavity of the first nozzle and the outer surface of the second nozzle enclose to form the injection channel.

[0012] In some embodiments of the present application, the second nozzle is detachably connected to the front end of the piston; And / or, the moving arc contact is detachably connected to the front end of the piston.

[0013] In some embodiments of the present application, a second one - way valve is provided on the piston, and the second one - way valve is configured to conduct unidirectionally from the compression chamber to the expansion chamber.

[0014] In some embodiments of the present application, one end of the first nozzle corresponding to the connection with the expansion chamber is configured as a flared mouth; And / or, one end of the first nozzle corresponding to the insertion into the static arc contact is configured as a flared mouth.

[0015] To solve the problem of improving the pressure - building capacity of the expansion chamber of the self - energy arc - extinguishing device, the self - energy arc - extinguishing device provided by this application includes a compression chamber, an expansion chamber, a first nozzle, and a moving arc contact. Among them, a movable piston and a piston pull rod connected to the piston are arranged in the compression chamber, and the piston pull rod is used to drive the piston to move; the expansion chamber is correspondingly arranged at one end of the piston connected to the compression chamber, and the front end of the piston can extend into the expansion chamber, and a pressure - increasing chamber is formed at the front end of the piston; the first nozzle is arranged at the end of the expansion chamber far from the compression chamber, and an arc - generating area is formed therein; the moving arc contact is arranged at the front end of the piston, a spray channel is formed between the moving arc contact and the inner cavity of the first nozzle, a first channel is arranged in the moving arc contact, one end of the first channel is communicated with the pressure - increasing chamber, and the other end of the first channel faces the arc - generating area; in addition, a first one - way valve is arranged on the circumferential wall of the pressure - increasing chamber, and the first one - way valve is configured to conduct unidirectionally from the pressure - increasing chamber to the expansion chamber.

[0016] In the actual application process of this self - energy arc - extinguishing device, when the circuit breaker interrupts the current, an arc - generating area will generate an arc. Under the action of the arc, the gas in the arc - generating area will instantaneously expand due to the increase in temperature. Since one end of the first channel is communicated with the pressure - increasing chamber and the other end faces the arc - generating area, the instantaneously expanded gas will enter the pressure - increasing chamber through the first channel, and the pressure in the pressure - increasing chamber will rise to a relatively high pressure at a relatively fast speed. Since the volume of the pressure - increasing chamber is much smaller than the volume of the expansion chamber, when the pressure in the pressure - increasing chamber is greater than the pressure in the expansion chamber, the air flow in the pressure - increasing chamber can enter the expansion chamber through the one - way valve, causing the pressure in the expansion chamber to increase. At the same time, it can also cooperate with the piston pull rod to pull the piston, forcing the compression chamber to charge and boost the pressure of the expansion chamber. The gas with increased pressure in the expansion chamber will be sprayed or rush to the arc - generating area through the spray channel, thus completing the arc - extinguishing operation. In this process, the source of building the pressure in the expansion chamber not only comes from the introduction of the compression chamber, but also makes full use of the expansion pressure caused by the arc energy, greatly improving the pressure - building capacity of the expansion chamber.

[0017] On the other hand, the embodiment of this application also provides a circuit breaker, including a self - energy arc - extinguishing device, and the self - energy arc - extinguishing device is the self - energy arc - extinguishing device described in any of the above solutions. Since the aforementioned self - energy arc - extinguishing device has the above technical effects, the circuit breaker with this self - energy arc - extinguishing device should also have corresponding technical effects, which will not be elaborated here.

[0018] On yet another hand, the embodiment of this application also provides a power system, including a circuit breaker, and the circuit breaker is the circuit breaker described in any of the above solutions. Since the aforementioned circuit breaker has the above technical effects, the power system with this circuit breaker should also have corresponding technical effects, which will not be elaborated here.

[0019] The technical features mentioned above, the technical features to be mentioned below, and the technical features shown separately in the drawings can be combined with each other arbitrarily, as long as the combined technical features are not mutually contradictory. All feasible feature combinations are the technical contents clearly recorded in this article. Any one of the multiple sub-features included in the same statement can be applied independently without necessarily being applied together with other sub-features. Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 It is a schematic internal structure diagram of the static arc contact and the moving arc contact in the self-powered arc extinguishing device provided by the embodiment of the present application in a separated state.

[0022] Among them, Figure 1 In: 1 - Moving arc contact; 2 - Second nozzle; 3 - Piston; 4 - Expansion chamber; 5 - Compression chamber; 6 - Piston rod; 7 - First nozzle; 8 - Static arc contact; 9 - Boost pressure chamber; 10 - Arc generation area; 11 - Injection channel; 12 - First channel; 13 - First one-way valve; 14 - Pressure relief valve; 15 - Second channel; 16 - Adjusting spring. Detailed Embodiments

[0023] The core of the present application is to provide a self-powered arc extinguishing device, a circuit breaker, and a power system to improve the pressure building ability of the expansion chamber of the self-powered arc extinguishing device.

[0024] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0025] In the power system, in addition to carrying the rated current, the circuit breaker also needs to carry the fault current generated by switching on and off or grounding, etc. Generally, the fault current is much larger than the rated current. When a fault current appears, an arc will be generated. An arc is a gas discharge phenomenon and has certain harm to electrical appliances. Therefore, it is necessary to extinguish the arc of the circuit breaker. Self-energy arc extinguishing is a main arc extinguishing method. The self-energy arc extinguishing chamber includes a compression chamber and an expansion chamber. When the gas pressure in the expansion chamber increases, insulating gas will be sprayed into the arc area, thereby extinguishing the arc. The increase in the gas pressure in the expansion chamber comes from two aspects. On the one hand, it is the arc energy generated during the breaking process, and on the other hand, it is the influx of high-pressure gas from the compression chamber.

[0026] The pressure magnitude of the expansion chamber plays a greater role in the breaking capacity of the arc extinguishing chamber. The greater the pressure in the expansion chamber, the better the breaking effect of the arc extinguishing chamber. Therefore, how to establish a higher pressure in the expansion chamber is an important research direction for the arc extinguishing chamber.

[0027] Based on this, the present application provides a self-energy arc extinguishing device, which is applied to a circuit breaker to improve the pressure building capacity of the expansion chamber of the self-energy arc extinguishing device.

[0028] Specifically, as shown in Figure 1 The self-energy arc extinguishing device includes a compression chamber 5, an expansion chamber 4, a first nozzle 7 and a moving arc contact 1. Among them, the compression chamber 5, the expansion chamber 4, the first nozzle 7 and the moving arc contact 1 are all located inside the housing of the circuit breaker. The inside of the housing is filled with arc extinguishing gas. By building pressure and relieving pressure on the expansion chamber 4, the arc extinguishing gas can have an arc extinguishing effect on the arc generation area 10.

[0029] Among them, a movable piston 3 and a piston pull rod 6 connected to the piston 3 are arranged in the compression chamber 5. The piston pull rod 6 is used to drive the piston 3 to move. The expansion chamber 4 is correspondingly connected to one end of the piston 3 of the compression chamber 5, and the front end of the piston 3 can extend into the expansion chamber 4. A pressure boosting chamber 9 is formed at the front end of the piston 3; the end of the piston 3 facing away from the expansion chamber 4 and the compression chamber 5 enclose a relatively closed space. By pulling the piston pull rod 6, the piston 3 can be controlled to slide in the compression chamber 5, and then the volume of the space enclosed by the piston 3 and the compression chamber 5 can be changed. For example, as shown in Figure 1As shown, pulling the piston rod 6 can compress the volume of the air compression chamber 5, causing the gas pressure in the air compression chamber 5 to increase. At the same time, a corresponding valve body is generally provided on the piston 3, and the gas in the air compression chamber 5 enters the expansion chamber 4 through this valve body and generates a pressure - building effect on the expansion chamber 4. Among them, the valve body can specifically but is not limited to a one - way valve. For example, a second one - way valve is provided on the piston 3, and this second one - way valve is configured to conduct unidirectionally from the air compression chamber 5 to the expansion chamber 4.

[0030] The first nozzle 7 is arranged at one end of the expansion chamber 4 away from the air compression chamber 5, and an arc - generating region 10 is formed inside the first nozzle 7. This arc - generating region 10 is specifically the spatial region where the corresponding moving arc contact 1 and static arc contact 8 in the circuit breaker perform opening and closing actions; the moving arc contact 1 is arranged at the front end of the piston 3 (that is, the end of the piston 3 facing the expansion chamber 4). A spray channel 11 is formed between the moving arc contact 1 and the inner cavity of the first nozzle 7. This spray channel 11 is mainly used to blow the arc - extinguishing gas gushing out from the expansion chamber 4 towards the arc - generating region 10. A first channel 12 is arranged inside the moving arc contact 1. The specific structural form of the first channel 12 can specifically but is not limited to a cavity structure arranged at the central position of the moving arc contact 1. One end of the first channel 12 is connected to the pressure - boosting air chamber 9, and the other end of the first channel 12 faces the arc - generating region 10.

[0031] In addition, a first one - way valve 13 is arranged on the circumferential wall of the pressure - boosting air chamber 9, and this first one - way valve 13 is configured to conduct unidirectionally from the pressure - boosting air chamber 9 to the expansion chamber 4.

[0032] In the actual application process of this self - energy arc - extinguishing device, when the circuit breaker interrupts the current, an arc - generating region 10 will accompany the generation of the arc. Under the action of the arc, the gas located in the arc - generating region 10 will instantaneously expand due to the increase in temperature. Since one end of the first channel 12 is connected to the pressure - boosting air chamber 9 and the other end faces the arc - generating region 10, therefore, the instantaneously expanding gas will enter the pressure - boosting air chamber 9 through the first channel 12, and cause the pressure in the pressure - boosting air chamber 9 to rise to a relatively high pressure at a relatively fast speed. Since the volume of the pressure - boosting air chamber 9 is much smaller than the volume of the expansion chamber 4, when the pressure in the pressure - boosting air chamber 9 is greater than the pressure in the expansion chamber 4, the air flow in the pressure - boosting air chamber 9 can enter the expansion chamber 4 through the first one - way valve 13, causing the pressure in the expansion chamber 4 to increase. At the same time, it can also cooperate with the piston rod 6 to pull the piston 3, forcing the air compression chamber 5 to inflate and boost the pressure of the expansion chamber 4. The gas with increased pressure in the expansion chamber 4 will be sprayed or gush towards the arc - generating region 10 through the spray channel 11, thus completing the arc - extinguishing operation. In this process, in addition to the pressure introduced from the air compression chamber 5, the pressure - building source of the air pressure in the expansion chamber 4 also makes full use of the expansion pressure caused by the arc energy, greatly improving the pressure - building ability of the expansion chamber.

[0033] It is worth mentioning that when the gas in the arc generation area 10 expands instantaneously due to the temperature rise, a small amount of gas will also enter the expansion chamber 4 through the injection channel 11. However, since the injection channel 11 is designed to achieve a relatively high purging effect, the opening gap of the injection channel 11 is usually small. Therefore, the amount of expansion gas in the arc generation area 10 entering the expansion chamber 4 through the injection channel 11 is relatively small, and the airflow entering the expansion chamber 4 from the self-pressurizing chamber 9 and the first one-way valve 13 through the first channel 12 is relatively larger.

[0034] In addition, the applicant has found through research that the airflow of the expansion gas in the arc generation area 10 entering the expansion chamber 4 from the self-pressurizing chamber 9 and the first one-way valve 13 through the first channel 12 not only has a better pressure-building effect on the expansion chamber 4 than that of the pressure gas chamber 5 on the expansion chamber 4, but also is the main source of the pressure building of the expansion chamber 4.

[0035] For better understanding of the self-energy arc extinguishing device provided by the present application by those skilled in the art, the following briefly describes its specific working process: Continue to refer to Figure 1 , the Figure 1 only shows a partial structure of the pressure gas chamber 5 and the piston rod 6, and the housing of the circuit breaker is omitted. The self-energy arc extinguishing device usually can be configured with an operating mechanism, which Figure 1 is not shown in the figure. It is mainly used to drive the closing and opening of the self-energy arc extinguishing device, that is, the engagement and disconnection between the moving arc contact 1 and the static arc contact 8.

[0036] Taking Figure 1 the state shown in the figure - the static arc contact 8 and the moving arc contact 1 are in a separated state as an example, when the static arc contact 8 and the moving arc contact 1 need to be engaged, the pressure gas chamber 5, the expansion chamber 4, the first nozzle 7, the piston 3 and the piston rod 6 can be driven by the operating mechanism to move as a whole towards the static arc contact 8 until the static arc contact 8 and the moving arc contact 1 are engaged. When the static arc contact 8 and the moving arc contact 1 need to be separated and disconnected, the pressure gas chamber 5, the expansion chamber 4, the first nozzle 7, the piston 3 and the piston rod 6 can be driven by the operating mechanism to move as a whole away from the static arc contact 8 until the static arc contact 8 and the moving arc contact 1 are separated.

[0037] Since the operating mechanism can adopt the operating mechanism in the prior art, the specific principle will not be described in detail here.

[0038] In some specific implementation schemes, the number of the above-mentioned first one-way valves 13 can be selected to be designed as one, or can be selected to be configured as multiple. Among them, when the first one-way valve 13 is designed to be multiple, it can be specifically designed to be distributed along the circumferential wall of the boosting air chamber 9. For example, it can be designed to be evenly distributed along the circumferential wall of the boosting air chamber 9. By designing it into this structural form, it is beneficial for the gas in the boosting air chamber 9 to enter the expansion chamber 4 more evenly, and then when the expansion chamber 4 purges the arc extinguishing gas into the arc occurrence area 10, the purging effect is more uniform and stable.

[0039] In some other specific implementation schemes, a second channel 15 may be provided in the piston rod 6. The specific arrangement may be, but is not limited to, a cavity structure coaxially arranged with the piston rod 6. For example, the piston rod 6 is a tubular structure, one end of the second channel 15 is connected to the boosting chamber 9 through a pressure relief valve 14, and the other end of the second channel 15 is connected to the inner cavity of the casing of the circuit breaker; wherein the pressure relief valve 14 is used to release the pressure of the boosting chamber 9 to the second channel 15 when the pressure in the boosting chamber 9 reaches a preset pressure value. By designing the second channel 15 and the pressure relief valve 14, the occurrence of damage to the boosting chamber 9 due to excessive pressure can be reduced. Among them, the preset pressure value usually meets the following requirements: the value should be as high as possible to ensure more effective use of the arc energy; at the same time, the value cannot exceed the strength limit of the part forming the boosting chamber 9 to ensure the safety of the part.

[0040] In a further embodiment, the pressure relief valve 14 can be specifically constructed as a pressure relief valve with an adjustable preset pressure value. Then, the preset pressure value of the pressure relief valve 14 can be adjusted according to actual needs, such as the strength of the booster chamber 9 itself.

[0041] The specific structural form of the pressure relief valve 14 to achieve adjustable preset pressure value is not limited. For example, the pressure relief valve 14 may be provided with an adjusting spring 16, and the preset pressure value of the pressure relief valve 14 is adjusted by adjusting the elastic force value of the adjusting spring 16, that is, the adjusting spring 16 can control the preset pressure value of the pressure relief valve 14. Of course, other pressure-adjustable pressure relief valve structures can also be designed, which are not specifically limited here.

[0042] In some other specific implementation schemes, the above-mentioned pressure relief valve 14 can be specifically selected to be arranged on the end surface where the piston rod 6 and the piston 3 are connected. With this design, when the pressure relief valve 14 is in a non-opened state, the volume of the boosting air chamber 9 and the second channel 15 can be minimized, which is more conducive to achieving rapid pressure increase in the boosting air chamber 9.

[0043] In some specific embodiments, the above-mentioned self-powered arc extinguishing device may further include a second nozzle 2 disposed outside the moving arc contact 1. The inner cavity of the first nozzle 7 and the outer surface of the second nozzle 2 enclose to form a spraying channel 11. By designing the second nozzle 2, the formation structure of the spraying channel 11 is not affected by the shape of the moving arc contact 1, and the structure of the spraying channel 11 can be optimized to better meet the effect of spraying and purging.

[0044] Wherein, the second nozzle 2 and the front end of the piston 3 may be specifically designed into a detachable connection structure form. For example, the second nozzle 2 and the front end of the piston 3 are connected by threads. By designing such a detachable structure form, the maintenance and replacement of the second nozzle 2 are more convenient. Of course, the second nozzle 2 and the front end of the piston 3 can also be designed into a non-detachable structure, such as a fixed connection method of integral molding or welding connection. In the actual application process, it can be selected and configured according to actual needs, and no specific limitation is made here.

[0045] In addition, the moving arc contact 1 and the front end of the piston 3 may also be specifically designed into a detachable connection structure form. For example, the moving arc contact 1 and the front end of the piston 3 are connected by threads. By designing such a detachable structure form, the maintenance and replacement of the moving arc contact 1 are more convenient. Of course, the moving arc contact 1 and the front end of the piston 3 can also be designed into a non-detachable structure, such as a fixed connection method of integral molding or welding connection. In the actual application process, it can be selected and configured according to actual needs, and no specific limitation is made here.

[0046] In some other specific embodiments, one end of the above-mentioned first nozzle 7 corresponding to the communication with the expansion chamber 4 may be specifically configured into a flared structure form. By setting such a structure form, the resistance of the gas in the expansion chamber 4 flowing into the inlet of the first channel 12 is smaller.

[0047] In addition, one end of the above-mentioned first nozzle 7 corresponding to being inserted into the static arc contact 8 may also be configured into a flared structure form, so that the air flow flowing into or spraying to the arc generation area 10 can be discharged into the housing of the circuit breaker more smoothly, reducing the air flow resistance.

[0048] On the other hand, the embodiment of the present application also provides a circuit breaker, including a self-powered arc extinguishing device, and the self-powered arc extinguishing device is the self-powered arc extinguishing device described in any of the above solutions. Since the foregoing self-powered arc extinguishing device has the above technical effects, the circuit breaker having the self-powered arc extinguishing device should also have the corresponding technical effects, which will not be elaborated here.

[0049] On the other hand, an embodiment of the present application further provides a power system, including a circuit breaker, and the circuit breaker is the circuit breaker described in any of the above solutions. Since the aforementioned circuit breaker has the above technical effects, the power system having such a circuit breaker should also have corresponding technical effects, which will not be elaborated herein.

[0050] It should be noted that the embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0051] As shown in the present application and the claims, unless the context clearly indicates an exceptional situation, the words such as "a", "an", "one" and / or "the" are not specifically singular and may also include the plural. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, in the description of the embodiments of the present application, unless otherwise specified, "a plurality of" means two or more than two.

[0052] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the core idea of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A self-energized arc extinguishing device, applied to a circuit breaker, characterized in that: include: A compressed air chamber (5) is provided with a movable piston (3) and a piston pull rod (6) connected to the piston (3), wherein the piston pull rod (6) is used to drive the piston (3) to move; An expansion chamber (4) is connected to one end of a piston (3) corresponding to the compression chamber (5), and a front end of the piston (3) can extend into the expansion chamber (4), and a boost chamber (9) is formed at the front end of the piston (3); A first nozzle (7) is arranged at one end of the expansion chamber (4) away from the compressed air chamber (5), and an arc generating area (10) is formed therein; A moving arc contact (1) is arranged at the front end of the piston (3), an injection channel (11) is formed between the moving arc contact (1) and the inner cavity of the first nozzle (7), a first channel (12) is arranged in the moving arc contact (1), one end of the first channel (12) is connected to the boosting air chamber (9), and the other end of the first channel (12) faces the arc generation area (10); A first one-way valve (13) is provided on the circumferential wall of the boost chamber (9), and the first one-way valve (13) is configured to conduct one-way flow from the boost chamber (9) to the expansion chamber (4).

2. The self-energized arc extinguishing device according to claim 1, characterized in that: The number of the first one-way valve (13) is one or more; Wherein, when there are multiple first one-way valves (13), the first one-way valves (13) are distributed along the circumferential wall of the boost air chamber (9).

3. The self-energized arc extinguishing device according to claim 1, characterized in that: A second channel (15) is provided in the piston pull rod (6), one end of the second channel (15) is connected to the boost air chamber (9) via a pressure relief valve (14), and the other end of the second channel (15) is communicated with the inner cavity of the casing of the circuit breaker; The pressure relief valve (14) is used to release the pressure of the boosting chamber (9) into the second channel (15) when the pressure in the boosting chamber (9) reaches a preset pressure value.

4. The self-powered arc extinguishing device according to claim 3, characterized in that: The pressure relief valve (14) is configured as a pressure relief valve with an adjustable preset pressure value.

5. The self-powered arc extinguishing device according to claim 4, characterized in that: The pressure relief valve (14) is provided with an adjusting spring (16), and the adjusting spring (16) is used to control a preset pressure value for the action of the pressure relief valve (14).

6. The self-powered arc extinguishing device according to claim 3, characterized in that: The pressure relief valve (14) is arranged on the end surface where the piston pull rod (6) is connected to the piston (3).

7. The self-energized arc extinguishing device according to claim 1, characterized in that: It also comprises a second nozzle (2) arranged on the outside of the moving arc contact (1), and the inner cavity of the first nozzle (7) and the outer surface of the second nozzle (2) are arranged to form the injection channel (11).

8. The self-powered arc extinguishing device according to claim 7, characterized in that: The second nozzle (2) is detachably connected to the front end of the piston (3); And / or, the moving arc contact (1) is detachably connected to the front end of the piston (3).

9. The self-energized arc extinguishing device according to any one of claims 1 to 8, characterized in that: The piston (3) is provided with a second one-way valve, and the second one-way valve is configured to conduct one-way communication from the compression chamber (5) to the expansion chamber (4).

10. The self-energized arc extinguishing device according to any one of claims 1, characterized in that: The end of the first nozzle (7) corresponding to the end communicating with the expansion chamber (4) is configured as a bell mouth; And / or, the end of the first nozzle (7) corresponding to the end inserted into the static arc contact (8) is configured as a bell mouth.

11. A circuit breaker, comprising a self-energizing arc extinguishing device, characterized in that: The self-energy arc extinguishing device is the self-energy arc extinguishing device as described in any one of claims 1-10.

12. An electric power system, comprising a circuit breaker, characterized in that: The circuit breaker is the circuit breaker according to claim 11.

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