Arc striking system, circuit breaker and electrical equipment
By designing an arc-induced system in a low-voltage circuit breaker, transferring the arc root and accelerating the arc movement using a U-shaped arc-induced plate, the problem of difficulty in quickly extinguishing the arc in the prior art is solved, and the current limiting and breaking capabilities of the circuit breaker are improved.
Patent Information
- Application Number
- CN202421236555.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-31
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-05-31
AI Technical Summary
In the event of overload or short circuit failure, the arc is difficult to quickly extinguish the arc, resulting in ablation of the static contact material and unfavorable arc movement, affecting the current limiting and breaking capabilities of the circuit breaker.
An arc-induced arc system is designed to transfer the arc root through the arc-induced angle and equipotential arc-induced arc plate on the moving contacts and static contacts, and the U-shaped arc-induced arc-induced arc is accelerated to move the arc-extinguishing grid, achieving rapid movement and extinguishing of the arc.
It effectively avoids the ablation of contact materials by the arc, improves the current limiting and breaking capabilities of the circuit breaker, and promotes the rapid arc extinguishing of the arc.
Smart Images
Figure CN222705423U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of low-voltage electrical appliances, and relates to an arc striking technology, in particular to an arc striking system, a circuit breaker and electrical equipment. Background Art
[0002] Low-voltage circuit breakers play a control and protection role in the power distribution system. When fault currents such as overload and short circuit occur, an arc will be generated between the contacts of the circuit breaker. The high temperature of the arc will burn the contact material. Therefore, one of the design difficulties of low-voltage circuit breakers is how to quickly extinguish the arc and protect the contacts.
[0003] In the prior art, static contact structures such as bottom-inlet and top-inlet are used to accelerate the movement of the static contact arc root. The moving arc root on the moving contact usually continues to burn on the moving contact until the arc is extinguished. On the one hand, it will seriously burn the static contact material, and on the other hand, it is not conducive to the movement of the arc to the arc extinguishing chamber. Utility Model Content
[0004] In view of the problems existing in the prior art, the utility model provides an arc striking system, a circuit breaker and an electrical device, which transfer the arc roots on the moving contact and the static contact, and at the same time accelerate the arc to move toward the arc extinguishing grid through the arc striking plate, thereby accelerating the movement of the arc as a whole, avoiding the arc ablation of the contact material, and improving the current limiting and breaking capacity of the circuit breaker.
[0005] The utility model is realized by the following technical solutions:
[0006] An arc striking system, comprising a moving contact, a moving contact arc striking angle, a moving contact equipotential arc striking plate, a stationary contact, a stationary contact arc striking angle, an arc striking sheet and an arc extinguishing chamber;
[0007] The moving contact comprises a moving conductive rod and a moving contact arranged at the end thereof and facing the side of the static contact. The moving contact arcing angle is fixed at the end of the moving conductive rod and located at the front end of the moving contact. The front end is the radial extension direction of the moving contact relative to the arc trajectory of the static contact opening movement.
[0008] The static contact comprises a static conductive rod and a static contact point arranged thereon, and the movable contact can make opening and closing movements relative to the static contact under the drive of the circuit breaker operating mechanism, and the static contact point contacts the movable contact when closing;
[0009] The arcing angle of the static contact is fixed at the end of the static contact and is located at the front end of the static contact;
[0010] The moving contact equipotential arc-starting plate is fixed at the upper end of the moving contact opening position, and the upper end is the movement direction of the moving contact opening;
[0011] The arc extinguishing chamber is located between the moving contact equipotential arc striking plate and the static contact arc striking angle, and the arc striking sheet is installed between the arc extinguishing grid sheets of the arc extinguishing chamber.
[0012] Preferably, the end of the moving contact arc striking angle is a pointed end or a chamfered end, which is used to generate an electric field concentration effect so that the moving arc root is transferred to the moving contact arc striking angle.
[0013] Preferably, when the moving contact and the stationary contact are in a closed position, the end of the moving contact arcing angle away from the stationary contact points in the direction of the moving contact equipotential arcing plate.
[0014] Preferably, the moving contact equipotential arc-starting plate and the moving conductive rod are connected to the same potential via a soft wire or a hard conductor.
[0015] Preferably, the moving contact equipotential arc-starting plate is mounted on the circuit breaker housing, or at the end of the arc extinguishing chamber.
[0016] Preferably, the arc-striking piece is a U-shaped arc-striking piece, and the opening end of the U-shaped arc-striking piece is far away from the moving contact.
[0017] Preferably, the arc-starting plate is located between the grid plates of the arc-extinguishing chamber and in the middle of the arc-extinguishing chamber.
[0018] Preferably, the two walls of the U-shaped arc-starting piece are arranged in parallel or at an angle.
[0019] Preferably, the moving contact arcing angle is made integrally with the moving contact, or is fixed to the moving contact by riveting, screw connection or welding.
[0020] Preferably, the arc-starting angle of the static contact is made integrally with the static contact, or is fixed to the static contact by riveting, screw connection or welding.
[0021] A circuit breaker comprises a circuit breaker body and the arc striking system, wherein a moving contact of the arc striking system is connected to an operating mechanism of the circuit breaker body.
[0022] An electrical device comprises a circuit breaker, wherein the arc striking system is arranged in the circuit breaker.
[0023] Compared with the prior art, the utility model has the following beneficial technical effects:
[0024] The utility model provides an arc-striking system, wherein the moving contact arc-striking angle is fixed at the end of the moving contact, the static contact arc-striking angle is fixed at the end of the static contact, the moving contact equipotential arc-striking plate is fixed at the upper end of the moving contact opening position, the arc-striking sheet is installed between the metal grids of the arc-extinguishing chamber, the static arc root on the static contact is quickly transferred to the static contact arc-striking angle, the moving arc root on the moving contact is quickly transferred to the moving contact equipotential arc-striking plate through the moving contact arc-striking angle, and at the same time, under the action of the arc-striking sheet, the arc is quickly moved to the cutting part of the arc-extinguishing grid, thereby accelerating the movement and extinguishing of the arc as a whole, avoiding the arc ablation of the contact material, and improving the current limiting and breaking capacity of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a structural schematic diagram of the arc striking system of the utility model;
[0026] Figure 2 It is a schematic diagram of the installation position of the moving contact, the static contact, the moving contact and the equipotential arc-starting plate of the utility model;
[0027] Figure 3 This is a schematic diagram of the internal structure of the arc striking system of the utility model;
[0028] Figure 4 It is a cross-sectional view of the arc striking system of the utility model.
[0029] In the figure: 1 moving contact, 2 moving contact arcing angle, 3 moving contact equipotential arcing plate, 4 static contact, 5 static contact arcing angle, 6 U-type arcing plate, 7 arc extinguishing chamber, 101 moving conductive rod, 102 moving contact, 401 static conductive rod, 402 static contact. DETAILED DESCRIPTION
[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.
[0031] See also Figure 1-4 An arc striking system includes a moving contact 1, a moving contact arc striking angle 2, a moving contact equipotential arc striking plate 3, a stationary contact 4, a stationary contact arc striking angle 5, a U-shaped arc striking piece 6 and an arc extinguishing chamber 7.
[0032] The moving contact 1 includes a moving conductive rod 101 and a moving contact 102 arranged at its end and facing the static contact. The moving contact arcing angle 2 is fixed at the end of the moving conductive rod 101 and is located at the front end of the moving contact 102, and the front end is the radial extension direction of the arc trajectory of the moving contact relative to the static contact 4 when the moving contact is in the opening state; the moving contact equipotential arcing plate 3 is fixed at the upper end of the opening position of the moving contact 1, and the upper end is the movement direction of the moving contact when the moving contact is in the opening state. The moving contact equipotential arcing plate 3 is connected to the moving contact 1 at the same potential.
[0033] The static contact 4 includes a static conductive rod 401 and a static contact 402 arranged thereon. The moving contact can perform opening and closing movements relative to the static contact 4 under the drive of the circuit breaker operating mechanism. When closing, the static contact 402 contacts the moving contact 102; the static contact arcing angle 5 is fixed at the end of the static contact 4 and is located at the front end of the static contact 402.
[0034] The arc extinguishing chamber 7 is located between the moving contact equipotential arc-striking plate 3 and the static contact arc-striking angle. A plurality of arc-striking grids spaced apart from each other are arranged in the arc extinguishing chamber 7. The U-shaped arc-striking plate 6 is installed between the arc-striking grids of the arc extinguishing chamber 7. The closed end of the U-shaped arc-striking plate 6 is close to the moving contact.
[0035] In the arc striking system, when the moving contact opens and closes the arc, the static arc root of the arc is quickly transferred to the static contact arc striking angle 5, and the arc column moves quickly toward the cutting part of the arc extinguishing grid under the action of the U-shaped arc striking plate 6. The moving arc root is transferred to the moving contact equipotential arc striking plate 3 under the guidance of the moving contact arc striking angle 2, which accelerates the movement of the arc as a whole, avoids the arc ablation of the contact material, and improves the current limiting and breaking capacity of the circuit breaker.
[0036] One end of the moving conductive rod 101 is a fixed end, and the other end is a moving end. The fixed end of the moving conductive rod 101 is connected to the circuit breaker operating mechanism, and the moving end is located between the moving contact equipotential arc-starting plate 3 and the static contact 4. During the opening and closing process, the moving conductive rod 101 rotates along the fixed end, so that the movable end of the moving conductive rod 101 rotates along an arc trajectory; the moving contact 102 is arranged on the side of the moving end of the moving contact 1 close to the static contact 4. When closing the circuit, the moving end of the moving conductive rod 101 rotates toward the static contact 4, so that the moving contact 102 contacts the static contact 4.
[0037] The moving contact arcing angle 2 is arranged at the end of the moving contact 1, and is used to guide the moving arc root of the arc on the moving contact 102 to the moving contact arcing angle 2, so as to solve the problem of arc erosion of the moving contact and improve the service life of the moving contact.
[0038] The moving contact arcing angle 2 is a metal sheet structure fixed at the moving end of the moving contact. The end of the moving contact arcing angle 2 close to the moving contact is a tip structure, which is used to generate an electric field concentration effect and accelerate the transfer of the moving arc root to the end of the arcing angle of the moving contact 1; the other end of the moving contact arcing angle 2 extends to the end face of the moving contact. When the moving contact and the static contact are in contact, the extended end of the moving contact arcing angle 2 points in the direction of the moving contact equipotential arcing plate 3.
[0039] The tip structure is a V-shaped pointed structure arranged at the end of the metal sheet, or a chamfered structure arranged at the end of the metal sheet, and the tip of the chamfer is located at a side of the metal sheet close to the moving contact 102 .
[0040] The moving contact equipotential arc-starting plate 3 is suspended at the end of the arc extinguishing chamber and is at the same potential as the moving contact. When the moving contact 1 moves to the opening position area, the moving arc root will be transferred to the moving contact equipotential arc-starting plate 3 under the guidance of the moving contact arc-starting angle 2. Since the moving contact equipotential arc-starting plate 3 is at the same potential as the moving contact 1, the moving arc root will be completely transferred to the moving contact equipotential arc-starting plate, thereby minimizing the erosion of the arc root on the contact.
[0041] The moving contact arcing angle 3 is made in one piece with the moving conductive rod, or is fixed to the moving conductive rod by riveting, screw connection or welding.
[0042] The moving contact equipotential arc-starting plate 3 is connected to the moving contact through a wire, so that the moving contact equipotential arc-starting plate 3 and the moving contact form an equipotential, and the wire can be a soft wire or a hard wire, which can be determined according to the use environment of the circuit breaker. The moving contact equipotential arc-starting plate 3 needs to be in a stable state, so the moving contact equipotential arc-starting plate 3 can be installed on the housing of the circuit breaker, or assembled at the end of the arc extinguishing chamber.
[0043] The static conductive rod 401 is fixedly arranged at the bottom of the arc extinguishing chamber, and the static contact 402 is arranged on the static conductive rod 401 and is located on the movement track of the moving contact 102. When closing the circuit breaker, the moving contact 102 is pressed against the static contact 402.
[0044] The static contact arcing angle 5 is fixed on the static conductive rod 401 and is located on the side of the static contact 402 away from the moving contact 1. The static contact arcing angle 5 is tilted on the static conductive rod 401, and the upper end of the static contact arcing angle 5 is tilted toward the arc extinguishing chamber, which is used to guide the static arc root of the arc on the static contact 402 to the static contact arcing angle 5, so as to solve the problem of arc erosion of the static contact and improve the service life of the static contact.
[0045] The static contact arcing angle 5 is made in one piece with the static contact 4, or is fixed on the static contact 4 by riveting, screw connection or welding.
[0046] The arc extinguishing chamber includes an insulating plate and an arc extinguishing grid. The two insulating plates are arranged at intervals. The U-shaped arc-starting plate 6 is fixedly arranged between the two insulating plates and located in the middle. The open end of the U-shaped arc-starting plate 6 is away from the moving contact. A plurality of grids are arranged in sequence at intervals on both sides of the U-shaped arc-starting plate 6, that is, the U-shaped arc-starting plate 6 is fixedly installed between the metal grids of the arc extinguishing chamber 7.
[0047] The two walls of the U-shaped arc-striking piece are arranged in parallel or at an angle, and the angle is an acute angle. When the moving contact 1 moves close to the U-shaped arc-striking piece 6, the arc contacts the U-shaped arc-striking piece 6, and an arc root is formed at the bottom of the U-shaped arc-striking piece 6. The arc root will move toward the cutting part of the arc extinguishing grid under the action of the magnetic field generated by the current on the arc-striking piece, thereby extinguishing the arc.
[0048] The working principle of the above arc striking system is described in detail below, as follows:
[0049] When the circuit breaker breaks the fault current, the moving contact 1 is separated from the static contact 4, and an arc is generated therebetween. The static arc root moves toward the static contact arc striking angle 5 under the action of the magnetic field generated by the current in the static conductive rod 401, and the moving arc root moves toward the end of the moving contact arc striking angle 2 under the action of the magnetic field generated by the current in the moving conductive rod 101. The electric field concentration at the tip of the moving contact arc striking angle 2 promotes the movement of the moving arc root. When the moving contact 1 moves close to the U-shaped arc striking piece 6, the arc column of the arc contacts the U-shaped arc striking piece 6. The moving contact 1 moves to the vicinity of the opening position, and the moving arc root is transferred to the moving contact equipotential arc striking plate 3 under the guidance of the moving contact arc striking angle 2. Since the arc striking plate 3 is at the same potential as the moving contact 1, the moving arc root is completely transferred to the arc striking plate, thereby minimizing the erosion of the contacts by the arc root.
[0050] Example 1
[0051] A circuit breaker comprises a circuit breaker body and the above-mentioned arc striking system arranged inside the circuit breaker body, wherein a moving contact of the arc striking system is connected to an operating mechanism of the circuit breaker body.
[0052] Example 2
[0053] An electrical device comprises a circuit breaker, wherein the circuit breaker is provided with the above-mentioned arc striking system.
[0054] Example 3
[0055] A 250A circuit breaker, in order to verify the effect of the technical solution of the present application, the arc striking system is used for a circuit breaker with a rated current of 250A. On the basis of the arc extinguishing system structure of the circuit breaker, the arc striking angle of the moving contact 1 is riveted on the moving contact 1, the arc striking angle of the static contact 4 is riveted on the static contact 4, and an equipotential arc striking plate is installed above the arc extinguishing chamber 7. The short-circuit breaking test uses the LC oscillation circuit as the test power supply, and the expected short-circuit current effective value of 18kA and 25kA are successively carried out. The original arc extinguishing system structure of the commercial circuit breaker on the market is compared with the technical solution of the present application. The main parameters are shown in Table 1 below.
[0056] Arc voltage is one of the important indicators that characterize the current limiting and arc extinguishing capabilities of low-voltage circuit breakers. The higher the arc voltage, the stronger the current limiting and arc extinguishing capabilities of the circuit breaker. Generally, when the arc in the low-voltage circuit breaker is elongated or enters the arc extinguishing grid and is cut, the arc voltage will rise. It can be seen from the data in Table 1 that in the test of breaking the expected short-circuit current effective value of 18kA and 25kA, the technical solution proposed in this application is compared with the original arc extinguishing system solution. The arc voltage peak value increased by 52.8% and 53.4%, respectively, and then the arcing time was shortened by 58.3% and 56.3%, respectively, indicating that the current limiting and arc extinguishing capabilities of the technical solution proposed in this application are significantly improved compared with the original solution. This is because the arc striking system of the technical solution can elongate the arc earlier and introduce it into the arc extinguishing chamber 7, so that the arc is fully in contact with the arc extinguishing grid, and then cut into multiple short arcs, thereby increasing the arc voltage, limiting the arc current value and arc energy, improving the arc extinguishing capability of the circuit breaker, and reducing the ablation of the contact material.
[0057]
[0058] The above content is only for explaining the technical idea of the utility model and cannot be used to limit the protection scope of the utility model. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the utility model shall fall within the protection scope of the claims of the utility model.
Claims
1. An arc striking system, characterized in that: It comprises a moving contact (1), a moving contact arcing angle (2), a moving contact equipotential arcing plate (3), a stationary contact (4), a stationary contact arcing angle (5), an arcing plate and an arc extinguishing chamber (7); The moving contact (1) comprises a moving conductive rod (101) and a moving contact (102) arranged at the end of the moving conductive rod and facing the side of the static contact, the moving contact arcing angle (2) is fixed at the end of the moving conductive rod (101) and is located at the front end of the moving contact (102), and the front end is the radial extension direction of the arc trajectory of the opening movement of the moving contact relative to the static contact (4); The stationary contact (4) comprises a stationary conductive rod (401) and a stationary contact (402) arranged thereon, and the moving contact can perform opening and closing movements relative to the stationary contact (4) under the drive of the circuit breaker operating mechanism, and when closing, the stationary contact (402) contacts the moving contact (102); The static contact arcing angle (5) is fixed at the end of the static contact (4) and is located at the front end of the static contact point (402); The moving contact equipotential arc-starting plate (3) is fixed at the upper end of the moving contact (1) at the opening position, and the upper end is the movement direction of the moving contact opening; The arc extinguishing chamber (7) is located between the moving contact equipotential arc striking plate (3) and the stationary contact arc striking angle, and the arc striking plate is installed between the arc extinguishing grid plates of the arc extinguishing chamber.
2. An arc striking system according to claim 1, characterized in that: The end of the moving contact arc striking angle (2) is a pointed end or a chamfered end, which is used to generate an electric field concentration effect so that the moving arc root is transferred to the moving contact arc striking angle.
3. An arc striking system according to claim 1, characterized in that: When the moving contact (1) and the stationary contact (4) are in a closed position, the end of the moving contact arc striking angle (2) away from the stationary contact points in the direction of the moving contact equipotential arc striking plate (3).
4. An arc striking system according to claim 1, characterized in that: The moving contact equipotential arc-starting plate (3) and the moving conductive rod (101) are connected to the same potential via a soft wire or a hard conductor.
5. An arc striking system according to claim 1, characterized in that: The moving contact equipotential arc-starting plate (3) is mounted on the circuit breaker housing, or mounted at the end of the arc-extinguishing chamber (7).
6. An arc striking system according to claim 1, characterized in that: The arc-striking piece is a U-shaped arc-striking piece (6), and the opening end of the U-shaped arc-striking piece (6) is far away from the moving contact.
7. An arc striking system according to claim 6, characterized in that: The arc-starting plate is located between the grid plates of the arc-extinguishing chamber and in the middle of the arc-extinguishing chamber.
8. An arc striking system according to claim 7, characterized in that: The two wall surfaces of the U-shaped arc-starting piece are arranged in parallel or at an angle.
9. An arc striking system according to claim 1, characterized in that: The moving contact arcing angle is made integrally with the moving contact, or is fixed on the moving contact by riveting, screw connection or welding.
10. An arc striking system according to claim 1, characterized in that: The static contact arcing angle is made integrally with the static contact, or is fixed on the static contact by riveting, screw connection or welding.
11. A circuit breaker, characterized in that: It comprises a circuit breaker body and the arc striking system according to any one of claims 1 to 10, wherein the moving contact of the arc striking system is connected to the operating mechanism of the circuit breaker body.
12. An electrical device, characterized in that: It comprises a circuit breaker in which the arc striking system according to any one of claims 1 to 10 is arranged.