A contact device of current repulsion type

Abstract

The present application relates to a current repulsion type contact device, comprising at least a static contact assembly and a dynamic contact assembly, the static contact assembly comprising at least a static contact, a static contact support, a first magnetic body and a second magnetic body; the dynamic contact assembly comprising at least a dynamic contact, a dynamic contact support and a dynamic contact elastic member, the current flowing through the static contact and the dynamic contact in opposite directions, under normal current state, the first magnetic body and the second magnetic body generate an attractive force to keep the static contact and the dynamic contact in reliable contact; under short-circuit current state, the static contact and the dynamic contact repel each other due to electrodynamic repulsion, at the same time, the static contact drives the first magnetic body to move to increase the distance between the two magnetic bodies, so as to weaken the attractive force, thereby accelerating the separation speed of the dynamic contact and the static contact and / or increasing the repulsion distance.

Description

[0001] This invention relates to switching electrical appliances, specifically to a current repulsion type contact device, belonging to the field of low-voltage electrical appliances. Background Technology

[0002] Contact devices are an important component of switching equipment, mainly composed of stationary contact assemblies and moving contact assemblies. Their performance directly affects the switching capacity, breaking capacity, and lifespan of the equipment. Under normal operating current, the stationary and moving contacts achieve circuit switching through mechanical closing and opening. However, during short-circuit faults, the contacts rely on the electrodynamic repulsive force generated by the current to quickly separate, achieving current limiting and arc extinguishing by lengthening the arc and increasing arc resistance. With the development of new energy sources (such as photovoltaics and energy storage) and DC microgrids, system voltage levels have generally increased to over 800V, significantly increasing the energy generated during short circuits and placing higher demands on the contact breaking speed and distance.

[0003] Limitations of current technology:

[0004] 1. Fixed stationary contact structure: The stationary contact is in a fixed position, and only the moving contact can repel it. As a result, the electric repulsion force only acts on one side, the effective repulsion stroke is limited, the repulsion speed is constrained by the elastic reaction force, the arc stagnation time is long, and it is easy to cause the contact material to be ablated. The breaking capacity is particularly insufficient in high voltage DC scenarios.

[0005] 2. Repulsive stationary contact structure: Although the stationary contact is repelled, the contact pressure is provided by an elastic element. During the repulsion process, the reaction force of the elastic element increases almost linearly with displacement, creating a counteracting effect against the electro-repulsive force. When the electro-repulsive force and the elastic reaction force reach equilibrium, the contact repulsion motion stops, significantly inhibiting the repulsion amplitude and speed of the stationary contact, and posing a risk of arc reignition. Experiments show that the breaking time is extended by more than 30% compared to the ideal value, with limited improvement in breaking performance.

[0006] There is an urgent need for a new structure that can significantly improve the contact repulsion speed and distance to enhance the breaking capacity of the switch and adapt to the application of switching electrical appliances in different scenarios. Summary of the Invention

[0007] This invention proposes a current repulsion type contact device, which is a contact mechanism controlled by magnetic force and repulsion coupling. By dynamically adjusting the spacing of the magnetic bodies through the repulsion movement of the stationary contact, the attractive force is changed, the repulsion resistance is reduced, and ultra-high speed breaking and multiplied opening distance of the contacts are achieved under short-circuit current. It aims to solve the problem of limited contact repulsion distance and insufficient speed in traditional switchgear during short-circuit breaking, which leads to difficulties in arc extinguishing. It is especially suitable for the high breaking capacity requirements of high voltage DC switchgear in fields such as new energy and rail transportation.

[0008] The technical solution of the present invention is as follows:

[0009] A current repulsion type contact device is disclosed, comprising at least a stationary contact assembly and a moving contact assembly. The stationary contact assembly includes at least a stationary contact, a stationary contact support, a first magnetic body, and a second magnetic body. The moving contact assembly includes at least a moving contact, a moving contact support, and a moving contact elastic member. The currents flowing through the stationary and moving contacts are in opposite directions. Under normal current conditions, the first and second magnetic bodies are either adjacent to each other or spaced apart, and the attraction between the first and second magnetic bodies maintains reliable contact between the stationary and moving contacts. Under short-circuit current conditions, the stationary and moving contacts repel each other due to electrodynamic repulsion, and the stationary contact drives the first magnetic body to move, increasing the distance between the first and second magnetic bodies and weakening the attraction.

[0010] In this manner, under normal current conditions, the first and second magnetic bodies of the contact device generate an attractive force that keeps the stationary and moving contacts in reliable contact, ensuring tight contact and generating stable contact pressure to guarantee minimum contact resistance and enable the switch to operate normally. Under short-circuit current conditions, the contact device utilizes the repulsive force (Lorentz force) generated by two conductors with opposite current directions, along with the Holm force and arc repulsion generated when the contacts break, collectively referred to as electrodynamic repulsion. Under the action of this electrodynamic repulsion, the stationary and moving contacts repel each other, multiplying the contact separation speed and making the separation process much faster.

[0011] The movement of the stationary contact drives the first magnetic body to move, increasing the distance between the two magnetic bodies. Utilizing the characteristic that the attractive force between the magnetic bodies monotonically decreases with increasing distance, a mechanical linkage design achieves rapid attenuation of the attractive force after repulsion is triggered. This reduces the resistance to the stationary contact's repulsion, further accelerating the separation speed and avoiding the separation delay caused by the increasing resistance of the reaction force of traditional elastic elements as the repulsion distance increases. This creates a positive feedback effect: short-circuit current → electric repulsion → increased magnetic distance → decreased attractive force → increased repulsion acceleration, further accelerating contact separation. The repulsion distance can also be adjusted arbitrarily without restriction.

[0012] Compared to traditional repellable stationary contacts, this contact device offers faster contact separation, a greater repulsion distance, and a faster arc elongation, leading to a rapid increase in arc resistance and thus faster arc extinguishing, further shortening the arc burning time. In high-voltage scenarios, rapid separation can withstand higher dielectric recovery strength, preventing arc reignition due to voltage recovery. Furthermore, it can forcibly cut off the current before it reaches its peak, limiting the short-circuit current and adapting to higher short-circuit currents and voltages, thereby significantly improving the short-circuit breaking capacity of the switching device.

[0013] In some embodiments, the first magnetic body and the stationary contact are fixed by a rigid connection or by insert molding.

[0014] In some embodiments, the first magnetic body is provided with a connector, and the stationary contact drives the first magnetic body to move through the connector.

[0015] In some embodiments, the stationary contact support is provided with a rotating shaft; the repulsive movement of the stationary contact is a rotation about the rotating shaft, which directly or indirectly changes the relative distance between the two magnetic bodies.

[0016] In some embodiments, the direction of motion of the first magnetic body is axial motion or tangential motion.

[0017] In some embodiments, the first magnetic body and the second magnetic body are both permanent magnets and are arranged in a manner with opposite poles, or one of the first magnetic body and the second magnetic body is a permanent magnet and the other is a magnetically conductive material.

[0018] In some embodiments, when both the first magnetic body and the second magnetic body are permanent magnets, the stationary contact drives one of the permanent magnets to move while the other permanent magnet is fixed; when one of the first magnetic body and the second magnetic body is a permanent magnet and the other is a magnetically conductive material, the stationary contact drives one of the magnetically conductive material or the permanent magnet to move while the other is fixed.

[0019] In the above embodiments, the initial attractive force is adjustable by selecting the magnetic material. The combination of dual permanent magnets, with opposite poles facing each other, provides a stronger initial attractive force. As the magnetic gap increases, the attractive force decays rapidly, making it more suitable for high-voltage, high-current short-circuit breaking. The combination of a single magnet and a magnetically conductive material eliminates the need for pole pairing, simplifies the process, and reduces costs by approximately 60%. Furthermore, changes in the magnetic gap cause the attractive force to decay slowly, making it more suitable for medium-sized breaking requirements.

[0020] In some embodiments, the stationary contact assembly is further provided with a reset elastic element, which is a compression spring, a tension spring, or a torsion spring; one end of the reset elastic element acts directly or indirectly on the stationary contact, and the other end is fixed to the stationary contact support or an external fixing structure.

[0021] In some embodiments, the reset elastic element stores energy during the repulsive movement of the stationary contact; when the electric repulsive force disappears, the stationary contact is automatically reset to the initial contact position by releasing the elastic potential energy.

[0022] In some embodiments, the pressure at one end of the reset elastic element acts on the stationary contact.

[0023] In some embodiments, the total holding force on the stationary contact in a stationary state is equal to the sum of the pressure of the reset elastic element and the attraction between the first magnetic body and the second magnetic body.

[0024] In the above embodiments, the reset elastic element has two functions: first, it acts on the stationary contact together with the attractive force generated by the two permanent magnets, and adopts a pressure compensation design and multi-force synthesis control, which can more conveniently adjust the various contact pressures required; second, the reset elastic element stores energy when the stationary contact moves away; when the electric repulsion force disappears, it releases elastic potential energy to reset the driven magnetic body and bring it close to the stationary magnetic body again, so that the stationary contact automatically resets to the initial contact position.

[0025] In some embodiments, the stationary contact assembly does not include a reset elastic element, and the reset of the stationary contact is achieved by manual operation or an electric drive device.

[0026] In the above embodiments, the stationary contact may not be reset, but is allowed to remain in a certain position after being pushed away. This increases the electrical clearance between the stationary contact and the moving contact, enabling the switch to have electrical isolation function under higher voltage, ensuring maintenance safety. After the short circuit fault is cleared, the stationary contact can be reset by manual or electric means.

[0027] In the above embodiments, the attractive force between the first magnetic body and the second magnetic body decreases monotonically as the distance increases.

[0028] In the above embodiments, the stationary contact head is provided with an alloy stationary contact point, and the connecting contact part is provided with a soft conductor or a planar contact structure.

[0029] The main innovation of this invention is that it proposes an innovative current repulsion type contact device, which achieves two working states through the cooperation of a stationary contact assembly and a moving contact assembly.

[0030] • Normal state: The first and second magnetic bodies provide stable contact pressure through a strong attraction between short gaps, keeping the contacts in close contact, ensuring minimum contact resistance, and reliably passing normal operating current.

[0031] • Short circuit state: The first magnetic body is displaced by the electric repulsion force, which increases the distance between the two magnetic bodies, weakens the attraction force, further accelerates the contact repulsion speed, increases the repulsion distance, and thus significantly improves the breaking capacity of the switchgear. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1This is a schematic diagram of the moving contact assembly and the stationary contact assembly of the contact device of the present invention in the contact state;

[0034] Figure 2 This is a schematic diagram of the moving contact assembly and the stationary contact assembly of the contact device of the present invention in the repulsive state;

[0035] Figure 3 for Figure 1 A schematic diagram of the intermediate static contact assembly in the contact state;

[0036] Figure 4 for Figure 2 Schematic diagram of the structure of the stationary contact assembly in the repulsive state;

[0037] Figure 5 for Figure 1 A schematic diagram of the moving contact assembly in the contact state;

[0038] Figure 6 for Figure 2 A schematic diagram of the moving contact assembly in the repulsive state;

[0039] Figure 7 This is a schematic diagram of the stationary contact structure of the present invention;

[0040] Figure 8 for Figure 1 A partial structural diagram;

[0041] Figure 9 for Figure 2 A partial structural diagram;

[0042] Figure 10 This is a 3D view of the stationary contact assembly;

[0043] Figure 11 This is a structural schematic diagram of the stationary contact support component. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some embodiments of this invention, but not all embodiments.

[0045] In the description of this invention, it should be noted that, unless otherwise stated, the terms "first" and "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance; "a plurality of" means two or more; the terms "inner," "outer," "left," "right," "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0046] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0047] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0048] like Figures 1 to 11 The present invention provides a current repulsion type contact device 1000, the contact device 1000 including a stationary contact assembly 100 and a moving contact assembly 200. The stationary contact assembly 100 includes at least a stationary contact 101, a stationary contact support 102, a first magnetic body 103, a second magnetic body 104, a connector 105, a reset elastic member 106, a rotating shaft 107, a flexible wire 108, a housing 109, and a receiving plate 110. The moving contact assembly 200 includes at least a moving contact 201, a moving contact support 202, and a moving contact elastic member 203. The current flowing through the stationary contact 101 and the moving contact 201 are in opposite directions. The stationary contact 101 is connected to the connecting plate connected to the external wire through the flexible conductor 108.

[0049] Specifically, one end of the connector 105 is fixedly connected to the first magnetic component 103, and the lower end of the other end is provided with a groove. The two ends are connected by a columnar body. The housing 109 is roughly barrel-shaped. The second magnetic component 104 is fixedly disposed at one end of the housing 109. The first magnetic component 103 and the second magnetic component 104 are disposed close to each other or have a certain distance. The smaller the distance, the greater the attraction between them. The other end of the housing 109 is provided with a shaft hole for the columnar body of the connector 105 to pass through. The reset elastic component 106 is located inside the housing 109. It is sleeved on the columnar body of the connector 105 and one end abuts against the end of the connector 105 connected to the first magnetic component 103. The other end abuts against the inner wall of the right side of the housing 109. The first magnetic component 103 can be slidably disposed inside the housing 109.

[0050] The reset elastic element 106 is a compression spring, tension spring, or torsion spring. One end of the reset elastic element 106 acts directly or indirectly on the stationary contact 101, and the other end is fixed to the stationary contact support 102 or an external fixing structure. It is used to reset the first magnetic body 103 and enhance the holding force on the stationary contact 101. The reset elastic element 106 stores energy when the stationary contact 101 moves away; when the electric repulsion force disappears, it releases elastic potential energy to automatically reset the stationary contact 101 to the initial contact position. The total holding force on the stationary contact 101 in the stationary state is equal to the sum of the pressure of the reset elastic element 106 and the attraction force of the first magnetic body 103 and the second magnetic body 104.

[0051] If the reset elastic element 106 is not provided, the holding force of the stationary contact 101 is entirely provided by the attraction between the first magnetic body 103 and the second magnetic body 104, and the reset is achieved by manual or electric means or other methods.

[0052] Please continue to refer to this. Figure 7 , Figure 10 and Figure 11 The stationary contact 101 is mounted on the rotating shaft 107 and can rotate around it. A driving member 1011 is provided at one end of the stationary contact 101 away from the alloy stationary contact point 1012. The driving member 1011 is a columnar protrusion extending from one side of the stationary contact 101. The driving member 1011 is located in a groove at one end of the connecting member 105 and can rotate in the groove. The connecting member 105 and the driving member 1011 are linked and can drive each other to move. The stationary contact support 102 is provided with a slot 1021. The two ends of the rotating shaft 107 are located in the slot 1021 and can rotate around the slot 1021. The receiving plate 110 is located above the stationary contact support 102 and the two are fixedly connected by screws. The housing 109 is located on the receiving plate 110. One end of the stationary contact 101 passes through the opening on the receiving plate 110 and is linked with the connecting member 105 through the driving member 1011.

[0053] like Figure 5 As shown, the moving contact 201 is rotatably mounted in the moving contact support 202 via the moving contact rotation shaft 204. The moving contact support 202 is provided with a motion groove 2021, and the moving contact 201, under the action of the elastic force of the moving contact elastic element 203, is by default stopped at the left end of the motion groove 2021.

[0054] like Figure 6As shown, when the contact device 1000 is subjected to a short-circuit current, the electric repulsion force generated between the moving contact 201 and the stationary contact 101 will overcome the elastic force of the moving contact elastic element 203, forcing the moving contact 201 to move counterclockwise around the moving contact rotation axis 204 until it moves to the right end of the moving groove 2021.

[0055] like Figure 1 , Figure 3 and Figure 5 As shown, the first magnetic body 103 and the second magnetic body 104 generate a strong attractive force when close together. This attractive force is transmitted to the stationary contact 101 through the connector 105, causing it to generate torque around the rotation axis 107. Under the pressure of the moving contact 201, the stationary contact remains stationary and does not displace. This structure ensures a tight contact between the stationary contact 101 and the moving contact 201, forming a stable contact pressure, thereby minimizing contact resistance and ensuring the smooth flow of normal current.

[0056] like Figure 1 , Figure 2 and Figure 4 As shown, the stationary contact 101 and the moving contact 201 are arranged as parallel conductors. Whether it is direct current or alternating current, the current flowing through them always flows in opposite directions. Based on the principle of Ampere's force (Lorentz force), the reverse current generates a mutually repulsive electrodynamic force. Simultaneously, during the contact breaking process, Holm force and arc repulsion are superimposed, together forming a strong electrodynamic repulsive force. When the contact device 1000 carries a short-circuit current, the electrodynamic repulsive force drives the stationary contact 101 and the moving contact 201 to move in opposite directions simultaneously.

[0057] The stationary contact 101 rotates clockwise around the stationary contact rotation axis 107 and drives the connecting member 105 to move to the right through the driving member 1011, overcoming the attraction between the first magnetic body 103 and the second magnetic body 104; the moving contact 201 overcomes the elastic force of the moving contact elastic member 203 and rotates counterclockwise around the moving contact rotation axis 203.

[0058] The moving contact 201 and the stationary contact 101 move in a "scissor-like" separation manner. The superposition of angular velocities significantly increases the separation speed and distance, rapidly elongating the arc and drastically increasing the arc resistance, thereby accelerating arc extinguishing and shortening the arc burning time. Experimental data shows that increasing the contact separation speed by 50% can shorten the arc burning time to 1 / 4 of the original time, reduce arc energy by 75%, significantly reduce contact erosion, and improve the electrical life and breaking reliability of the switching device.

[0059] Based on Coulomb's law for permanent magnets, the attractive force between the first magnetic body 103 and the second magnetic body 104 decreases monotonically with increasing spacing. As the spacing increases, the attractive force rapidly diminishes until it disappears. This rapidly reduces the resistance to the repulsion of the stationary contact 101, while simultaneously accelerating the separation speed. This creates a positive feedback effect—short-circuit current → electrodynamic repulsion → increased magnetic spacing → decreased attractive force → increased repulsion acceleration, further accelerating contact separation. Compared to existing stationary contacts on the market, this design experiences less resistance during breaking, and this resistance does not significantly increase with increasing breaking distance.

[0060] If a reset elastic element 106 is provided, the reset elastic element 106 stores energy when the first magnetic body 103 moves. When the repulsive force disappears, the reset elastic element 106 releases its stored elastic potential energy, pushing the first magnetic body 103 closer to the second magnetic body 104. As the distance between the first magnetic body 103 and the second magnetic body 104 decreases, the attractive force between them is strengthened again. This attractive force, together with the elastic force of the reset elastic element 106, is transmitted to the driving element 1011 through the connecting member 105, driving the stationary contact 101 to rotate counterclockwise around the stationary contact rotation axis 107. This movement causes the stationary contact 101 to reapply stable contact pressure to the moving contact 201, ensuring tight contact between the contacts, thereby providing a reliable conductive path for the flow of normal current.

[0061] This invention may be implemented in other specific forms without departing from its spirit and essential characteristics. The present embodiments are to be regarded in all respects as exemplary rather than limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and all modifications falling within the meaning of the claims and their equivalents are thus included within the scope of the invention.

Claims

1. A current repulsion type contact device (1000), said contact device (1000) comprising at least a stationary contact assembly (100) and a moving contact assembly (200), characterized in that: The stationary contact assembly (100) includes at least a stationary contact (101), a stationary contact support (102), a first magnetic body (103), and a second magnetic body (104); The moving contact assembly (200) includes at least a moving contact (201), a moving contact support (202), and a moving contact elastic member (203); The current flowing through the stationary contact (101) and the moving contact (201) are in opposite directions; In the normal current state, the first magnetic body (103) and the second magnetic body (104) of the contact device (1000) are close to each other or there is a gap between them. The attraction between the first magnetic element (103) and the second magnetic element keeps the stationary contact (101) and the moving contact (201) in reliable contact. When the contact device (1000) is in a short-circuit current state, the stationary contact (101) and the moving contact (201) repel each other due to electric repulsion, and the stationary contact (101) drives the first magnetic body (103) to move, thereby increasing the distance between the first magnetic body (103) and the second magnetic body (104) and weakening the attraction force.

2. The contact device (1000) according to claim 1, characterized in that: The first magnetic body (103) is fixed to the stationary contact (101) by a rigid connection or by an insert molding method.

3. The contact device (1000) according to claim 1, characterized in that: The first magnetic body (103) is provided with a connector (105), and the stationary contact (101) drives the first magnetic body (103) to move through the connector (105).

4. The contact device (1000) according to any one of claims 1 to 3, characterized in that: The stationary contact support (102) is provided with a rotating shaft (107); the repulsive movement of the stationary contact (101) is a rotation about the rotating shaft (107), which directly or indirectly changes the relative distance between the two magnetic bodies.

5. The contact device (1000) according to any one of claims 1 to 3, characterized in that: The first magnetic body (103) moves in either an axial or tangential direction.

6. The contact device (1000) according to any one of claims 1 to 3, characterized in that: The first magnetic body (103) and the second magnetic body (104) are both permanent magnets and are arranged in a manner with opposite poles, or one of the first magnetic body (103) and the second magnetic body (104) is a permanent magnet and the other is a magnetically conductive material.

7. The contact device (1000) according to claim 6, characterized in that: When both the first magnetic body (103) and the second magnetic body (104) are permanent magnets, the stationary contact (101) drives one of the permanent magnets to move while the other permanent magnet is fixed. When one of the first magnetic body (103) and the second magnetic body (104) is a permanent magnet and the other is a magnetically conductive material, the stationary contact (101) drives one of the magnetically conductive material or the permanent magnet to move while the other is fixed.

8. The contact device (1000) according to claim 1, characterized in that: The stationary contact assembly (100) is also provided with a reset elastic element (106), which is a compression spring, tension spring or torsion spring; one end of the reset elastic element (106) acts directly or indirectly on the stationary contact (101), and the other end is fixed to the stationary contact support (102) or an external fixing structure.

9. The contact device (1000) according to claim 8, characterized in that: The reset elastic element (106) stores energy when the stationary contact (101) moves away; when the electric repulsion force disappears, it releases the elastic potential energy to automatically reset the stationary contact (101) to the initial contact position.

10. The contact device (1000) according to claim 8, characterized in that: The pressure at one end of the reset elastic element (106) acts on the stationary contact (101).

11. The contact device (1000) according to claim 8, characterized in that: The total holding force on the stationary contact (101) in a stationary state is equal to the sum of the pressure of the reset elastic element (106) and the attraction between the first magnetic body (103) and the second magnetic body (104).

12. The contact device (1000) according to claim 1, characterized in that: The stationary contact assembly (100) does not include a reset elastic element (106), and the reset of the stationary contact (101) is achieved by manual operation or electric drive.

13. The contact device (1000) according to claim 1, characterized in that: The attraction between the first magnetic body (103) and the second magnetic body (104) decreases monotonically as the distance increases.

14. The contact device (1000) according to claim 1, characterized in that: The stationary contact (101) is provided with an alloy stationary contact point (1012), and the connecting contact part is provided with a soft conductor (108) or a planar contact structure.

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