Contact structure for raising arc voltage under external magnetic field

Abstract

The application relates to a contact structure for raising arc voltage under an external magnetic field, belonging to the technical field of circuit breaker devices, which comprises a static contact, a dynamic contact arranged on one side of the static contact and parallel to each other, two first metal contact petals symmetrically arranged on one side of a contact surface of the static contact and the dynamic contact, and a plurality of second metal contact petals symmetrically arranged on the contact surface of the static contact and the dynamic contact, the adjacent second metal contact petals and the first metal contact petals and the second metal contact petals are disconnected to form a plurality of open slots, the melting point of the second metal contact petals is higher than that of the first metal contact petals, and the external magnetic field is arranged outside the static contact and the dynamic contact; the first metal contact petals and the second metal contact petals are used in cooperation with the static contact and the dynamic contact, arc striking on the first metal contact petals can be realized, the arc is driven to move fast to the edge of the first metal contact petals by the Lorentz force under the action of the external magnetic field, the arc voltage is raised, and the conductive surface is prevented from being ablated by the contact.

Description

Technical Field

[0001] This invention belongs to the technical field of circuit breaker equipment, specifically relating to a contact structure that increases arc voltage under an external magnetic field. Background Technology

[0002] With continuous social development and the interconnection of multiple energy sources, my country's power industry is constantly evolving, resulting in more complex and diverse system structures and operating modes, and a gradual increase in system capacity. This leads to a significant potential impact from short-circuit hazards. Therefore, there is an urgent need for reliable short-circuit fault isolation technologies, and circuit breakers are key equipment for short-circuit fault isolation in power systems. While AC circuit breakers have matured due to the continuous development of AC systems, the integration of new energy sources and the vigorous development of distributed energy have led to the gradual improvement of DC systems. From miniaturized locomotive DC circuit breakers to ultra-high voltage DC transmission system circuit breakers, DC system capacity is also gradually increasing. Short-circuit fault modes are becoming more diverse, and the short-circuit current rise rate is higher, placing higher demands on the breaking capacity of DC circuit breakers. Compared to AC breaking, DC breaking lacks a natural zero-crossing point, presenting numerous technical challenges.

[0003] Existing DC interruption methods include forced zero-crossing, transfer interruption, and arc voltage enhancement. Forced zero-crossing involves superimposing a reverse current on the original current to generate a zero-crossing point for interruption. Transfer interruption connects a transfer switch in parallel with a power electronic circuit breaker or fuse, rapidly transferring current to the parallel device during a fault. Arc voltage enhancement directly increases the arc voltage to the system voltage for DC interruption. Circuit breakers require high-performance contacts during rapid operation, demanding not only rapid arc extinguishing but also high contact strength and long service life.

[0004] When using the method of increasing arc voltage for DC switching, it is necessary to fix the position of the arc ignition point and quickly extinguish the arc. Currently, existing patent document CN113205983B discloses a fast mechanical switch flat contact with an arc-ignition device, which can fix the position of the arc ignition point and achieve rapid arc extinguishing to a certain extent. However, the arc generated at the fixed point can only be extinguished naturally to achieve switching, which not only easily leads to the conductive surface being ablated by the contact, but also the structure for fixing the arc ignition point is relatively complex, affecting the normal current-carrying area and preventing large-scale application. Summary of the Invention

[0005] In view of this, the present invention provides a contact structure for increasing arc voltage under an external magnetic field. By using a stationary contact, a moving contact, and first and second metal contact petals in conjunction, it is possible not only to enable the arc to ignite on the low-melting-point first metal contact petal and fix the position of the arc ignition point, but also, under the action of an external magnetic field, the arc is driven by the Lorentz force to move rapidly towards the edge of the first metal contact petal to increase the arc voltage. This achieves rapid arc extinguishing while preventing the conductive surface from being burned by the contact, ensuring normal current flow in the contact, and further improving the breaking capacity of the contact.

[0006] The technical solution of this invention is: a contact structure for increasing arc voltage under an external magnetic field, comprising a stationary contact, a moving contact, a conductive rod, two first metal contact lobes, multiple second metal contact lobes, an open slot, and an external magnetic field; the moving contact is disposed on one side of the stationary contact and parallel to each other, the contact surface of the stationary contact and the moving contact is flat, and its non-contact surface is connected to the main circuit through the conductive rod; the two first metal contact lobes are symmetrically disposed on one side of the contact surface of the stationary contact and the moving contact, and the first metal contact lobes are fixedly connected to the stationary contact and the moving contact; the multiple second metal contact lobes are symmetrically disposed on the stationary contact and the moving contact. On the contact surface of the moving contact, the second metal contact petal is fixedly connected to the stationary contact and the moving contact. Adjacent second metal contact petals and the first metal contact petal and the second metal contact petal are disconnected to form multiple open slots. The multiple open slots are parallel to each other. The melting point of the second metal contact petal is higher than that of the first metal contact petal. An external magnetic field is set on the outside of the stationary contact and the moving contact. The magnetic field lines of the external magnetic field pass through the stationary contact and the moving contact. The direction of the external magnetic field is parallel to the open slots. The direction of the Lorentz force on the contact surface of the stationary contact and the moving contact is towards one side of the first metal contact petal.

[0007] Preferably, the total number of the first metal contact flap and the second metal contact flap is n, the number of opening slots is n-1, and the area of ​​the first metal contact flap is less than or equal to the area of ​​the second metal contact flap.

[0008] Preferably, two bases are symmetrically provided on the non-contact surfaces of the stationary contact and the moving contact. One side of the base is fixedly connected to the stationary contact and the moving contact respectively, and the other side is fixedly connected to the conductive rod.

[0009] Preferably, the contact surfaces of the stationary and moving contacts are any one of rectangle, ellipse, circle, or rhombus, and the opening groove is parallel to the long side of the rectangle, the long axis of the ellipse, and the long axis of the rhombus.

[0010] Preferably, the edges of the first metal contact flap and the second metal contact flap are located inside the edges of the stationary contact and the moving contact, and the outer shapes of the first metal contact flap and the second metal contact flap are the same as the outer shapes of the stationary contact and the moving contact.

[0011] Preferably, the external magnetic field is a permanent magnet or a coil, which is fixed on the outside of the stationary contact and the moving contact.

[0012] Preferably, the first metal contact flap is made of any one of pure copper, pure silver, or copper-silver alloy, and the second metal contact flap is made of any one of pure tungsten or copper-tungsten alloy.

[0013] Preferably, the groove spacing of the opening is 1mm-2mm.

[0014] Compared with existing technologies, the present invention provides a contact structure for increasing arc voltage under an external magnetic field. By using a stationary contact, a moving contact, and first and second metal contact petals in conjunction, it not only enables the arc to ignite on the low-melting-point first metal contact petal and fixes the position of the arc ignition point, but also, under the action of an external magnetic field, the Lorentz force drives the arc to move rapidly towards the edge of the first metal contact petal, increasing the arc voltage. This achieves rapid arc extinguishing while preventing the conductive surface from being burned by the contact, ensuring normal current flow. Furthermore, the opening slots between adjacent second metal contact petals and between the first and second metal contact petals allow the arc to potentially jump from one contact petal across the slot to another. However, the overall arc movement distance is shorter than that of traditional contacts, and only a portion of the arc jumps, increasing the unstable speed of the arc and causing a rapid increase in arc voltage, further enhancing the overall breaking capacity of the contact. The contact structure of the present invention has strong DC starting capability, long lifespan, and high practicality, making it worthy of promotion. Attached Figure Description

[0015] Figure 1 This is a front view of the present invention;

[0016] Figure 2 This is a cross-sectional view of the present invention;

[0017] Figure 3 This is a perspective view of the present invention;

[0018] Figure 4 This is a perspective view of the present invention where the lower and second metal contact petals have the same area;

[0019] Figure 5 This is a perspective view of the present invention with different areas of the lower and second metal contact petals;

[0020] Figure 6 This is a side view of the present invention with different areas of the lower and second metal contact flaps. Detailed Implementation

[0021] This invention provides a contact structure for increasing arc voltage under an external magnetic field, which is described below in conjunction with... Figures 1 to 6 The present invention is illustrated by the structural diagram shown below.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of 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. Therefore, they should not be construed as limitations on this invention.

[0023] With continuous social development and the interconnection of multiple energy sources, my country's power industry is constantly evolving, resulting in more complex and diverse system structures and operating modes, and a gradual increase in system capacity. This leads to a significant potential impact from short-circuit hazards. Therefore, there is an urgent need for reliable short-circuit fault isolation technologies, and circuit breakers are key equipment for short-circuit fault isolation in power systems. While AC circuit breakers have matured due to the continuous development of AC systems, the integration of new energy sources and the vigorous development of distributed energy have led to the gradual improvement of DC systems. From miniaturized locomotive DC circuit breakers to ultra-high voltage DC transmission system circuit breakers, DC system capacity is also gradually increasing. Short-circuit fault modes are becoming more diverse, and the short-circuit current rise rate is higher, placing higher demands on the breaking capacity of DC circuit breakers. Compared to AC breaking, DC breaking lacks a natural zero-crossing point, presenting numerous technical challenges.

[0024] Existing DC interruption methods include forced zero-crossing, transfer interruption, and arc voltage enhancement. Forced zero-crossing involves superimposing a reverse current on the original current to generate a zero-crossing point for interruption. Transfer interruption connects a transfer switch in parallel with a power electronic circuit breaker or fuse, rapidly transferring current to the parallel device during a fault. Arc voltage enhancement directly increases the arc voltage to the system voltage for DC interruption. Circuit breakers require high-performance contacts during rapid operation, demanding not only rapid arc extinguishing but also high contact strength and long service life.

[0025] When using the method of increasing arc voltage for DC switching, it is necessary to fix the position of the arc ignition point and quickly extinguish the arc. Currently, existing patent document CN113205983B discloses a fast mechanical switch flat contact with an arc-ignition device, which can fix the position of the arc ignition point and achieve rapid arc extinguishing to a certain extent. However, the arc generated at the fixed point can only be extinguished naturally to achieve switching, which not only easily leads to the conductive surface being ablated by the contact, but also the structure for fixing the arc ignition point is relatively complex, affecting the normal current-carrying area and preventing large-scale application.

[0026] Based on the above problems, the present invention provides a contact structure for increasing arc voltage under an external magnetic field. By using a stationary contact, a moving contact, and first and second metal contact petals in conjunction, it not only enables the arc to ignite on the low-melting-point first metal contact petal and fixes the position of the arc ignition point, but also, under the action of an external magnetic field, the arc is driven by the Lorentz force to move rapidly towards the edge of the first metal contact petal to increase the arc voltage. This achieves rapid arc extinguishing while preventing the conductive surface from being burned by the contact, ensuring normal current flow in the contact, and further improving the breaking capacity of the contact.

[0027] Example 1

[0028] like Figure 1 , 3 As shown, a contact structure for increasing arc voltage under an external magnetic field includes a stationary contact 1, a moving contact 2, a conductive rod 3, first metal contact petals 4, second metal contact petals 5, and opening slots 6. The moving contact 2 is disposed on one side of the stationary contact 1 and is parallel to each other. The contact surfaces of the stationary contact 1 and the moving contact 2 are flat, and their non-contact surfaces are connected to the main circuit through the conductive rod 3. Two first metal contact petals 4 are symmetrically disposed on one side of the contact surfaces of the stationary contact 1 and the moving contact 2, and the first metal contact petals 4 are fixedly connected to the stationary contact 1 and the moving contact 2. Multiple second metal contact petals 5 are symmetrically disposed on the contact surfaces of the stationary contact 1 and the moving contact 2, and the second metal contact petals 5 are fixedly connected to the stationary contact 1 and the moving contact 2. Multiple opening slots 6 are formed by the gaps between adjacent second metal contact petals 5 and between the first metal contact petals 4 and the second metal contact petals 5. The multiple opening slots 6 are parallel to each other. The melting point of the first metal contact lobe 5 is higher than that of the first metal contact lobe 4. An external magnetic field is set on the outside of the stationary contact 1 and the moving contact 2. Metal contact lobes with different melting points are distributed on the contact surface of the contacts, so that the electric arc is generated on the local first metal contact lobe on the contact surface, thereby further shortening the arc movement distance, increasing the movement speed, enhancing the breaking capacity, and ensuring the stable and safe operation of the power system. There are opening slots between the contact lobes. The opening slots 6 are actually the boundaries of the metal contact lobes and are used to divide the metal contact lobes. The number of contact lobes and the number of opening slots can be adjusted. The area ratio of metal contact lobes with different melting points is determined according to the number and position of the opening slots. The magnetic field lines of the external magnetic field pass through the stationary contact 1 and the moving contact 2. The magnetic field direction of the external magnetic field is parallel to the opening slots 6. The direction of the Lorentz force on the contact surface of the stationary contact 1 and the moving contact 2 is towards the side of the first metal contact lobe 4.

[0029] When a power system fault occurs, the temperature between the stationary and moving contacts reaches the melting point of the lower-melting-point metal first. At this point, the lower-melting-point metal is in a molten state, meaning that liquid and solid states coexist. As the temperature continues to rise and reaches the melting point of the higher-melting-point metal, the higher-melting-point metal begins to melt. However, at this point, the molten portion of the lower-melting-point metal is more liquid. When the stationary and moving contacts are opened, because the molten portion of the higher-melting-point metal is less than that of the lower-melting-point metal, the liquid metal bridge on the second metal contact piece is more likely to break first, leaving liquid metal on the first metal contact piece. With a longer bridge length and later fracture time, the liquid metal bridge of the low-melting-point metal will remain conductive until arcing occurs, meaning the arc will be generated on the first metal contact lobe. The arc ignition position is fixed, and combined with the short arc movement distance on a single contact lobe, the arc voltage is rapidly increased. At the same time, the arc is subjected to the Lorentz force under the external magnetic field. The direction of the Lorentz force can be adjusted, causing the arc to move along a shorter distance on the contact lobe to the edge of the contact lobe, which can further rapidly increase the arc voltage while reducing the contact ablation area.

[0030] Preferably, two bases 31 are symmetrically provided on the non-contact surfaces of the stationary contact 1 and the moving contact 2. One side of the base 31 is fixedly connected to the stationary contact 1 and the moving contact 2 respectively, and the other side is fixedly connected to the conductive rod 3. By using the base as the electrical connection part of the contact, the impedance of the arc-extinguishing chamber is reduced when the contact is closed.

[0031] Preferably, the edges of the first metal contact petal 4 and the second metal contact petal 5 are located inside the edges of the stationary contact 1 and the moving contact 2, and the outer shapes of the first metal contact petal 4 and the second metal contact petal 5 are the same as the outer shapes of the stationary contact 1 and the moving contact 2.

[0032] Preferably, the external magnetic field is a permanent magnet or a coil, which is fixed on the outside of the stationary contact 1 and the moving contact 2. The permanent magnet or coil can drive the electric arc on the first metal contact petal to move towards the edge of the contact petal, thereby increasing the speed of the electric arc movement.

[0033] Preferably, the first metal contact flap 4 is made of any one of pure copper, pure silver, or copper-silver alloy, and the second metal contact flap 5 is made of any one of pure tungsten or copper-tungsten alloy.

[0034] Preferably, the slot spacing of the opening slot 6 is 1mm-2mm. The metal contact petals and the opening slots are similar to a gate structure. This structure shortens the width of each contact petal, further shortens the distance the arc moves in the direction of the Lorentz force, and causes the arc to move to the edge at a faster speed, thus increasing the arc voltage more quickly. When an arc transition occurs, the larger the slot spacing of the opening slots, the less likely the arc is to transition from one metal contact petal to another. However, the opening slots only serve as the dividing line between metal contact petals with different melting points, and the slot spacing should not be too large, otherwise it will affect the current carrying effect. Generally, the slot spacing of the small opening slots is set to be relatively small, about 1mm-2mm.

[0035] Example 2

[0036] To further enhance the overall breaking capacity of the contacts, opening slots are provided between adjacent second metal contact segments and between the first and second metal contact segments. This allows the arc to jump from one contact segment to another across the opening slot. However, the overall arc travel distance is shorter than that of traditional contacts, and only a portion of the arc jumps. This increases the speed of arc instability and causes the arc voltage to rise rapidly.

[0037] Preferably, the total number of first metal contact petals 4 and second metal contact petals 5 is n, and the number of opening slots 6 is n-1. The area of ​​the first metal contact petal 4 is less than or equal to the area of ​​the second metal contact petal 5. For metal contact petals with different melting points and opening slots, changing the number or position of the opening slots can change the area distribution ratio of metal petals with different melting points. For example, when there are two metal contact petals and one opening slot, the position of the opening slot can be at 1 / 2, 1 / 3, or 1 / 4 of the entire contact piece, and the area ratio of the high melting point metal petal to the area of ​​the first metal contact petal is determined to be 1:1 or 2. The ratio of 1 to 3:1 reduces the area of ​​a single metal contact lobe, which can effectively reduce the arc movement distance on a single contact lobe and increase the speed at which the arc moves to the edge. However, due to the presence of the Lorentz force, some of the arc will still jump from one metal contact lobe across the opening slot to another melting point metal contact lobe. But only a portion of the arc jumps, so the arc movement distance is still much smaller than that of the traditional contact structure. It can move to the contact edge quickly, accelerate the arc extinguishing, and only a portion of the arc jumps, which makes the arc unstable and speed up, resulting in a rapid increase in arc voltage.

[0038] Example 3

[0039] To further improve the speed of arc extinguishing, various contact surface shapes are used to facilitate different application scenarios. Furthermore, the opening slots are parallel to the long side of the rectangle, the long axis of the ellipse, and the long axis of the rhombus, which can effectively shorten the width of the short axis of a single contact lobe, thereby shortening the arc movement distance and making it easier to increase the arc voltage.

[0040] Preferably, the contact surfaces of the stationary contact 1 and the moving contact 2 are any one of rectangle, ellipse, circle, or rhombus. The opening slot 6 is parallel to the long side of the rectangle, the major axis of the ellipse, and the major axis of the rhombus. There are various shapes of the contact surfaces, and each shape has a "longer line" and a "shorter line", such as the length and width of the rectangle, the major axis and minor axis of the rhombus, the major axis and minor axis of the ellipse, etc. When the contacts are pulled apart, the applied external magnetic field will cause the electric arc formed in the contact gap to move along the direction of the Lorentz force. Since the direction of the external magnetic field is parallel to the contact plane and perpendicular to the current direction, the Lorentz force is also parallel to the contact plane. The direction of the Lorentz force can be adjusted according to the current direction and the magnetic field direction, but it mainly causes the electric arc to move to the edge of the contact along a certain short distance. At this time, the distance that the electric arc moves to the edge of the contact is shorter than that of ordinary contacts, which can quickly increase the arc voltage.

[0041] like Figure 2 The diagram shows a cross-section of the contact structure, which is actually a rectangle with inconsistent length and width. The horizontal direction represents the length of the rectangle, and the vertical direction represents the width of the rectangle. The contact piece is divided into two parts along the vertical direction, with the second metal contact lobe and the first metal contact lobe each occupying half. The boundary between the two metal contact lobes is an open groove. At this time, the width of each metal contact lobe is half of that before the division.

[0042] The applied external magnetic field is horizontal from left to right, and the current direction is inward. At this time, the Lorentz force generated on the entire contact is vertically upward, forcing the arc to move upward, that is, to move vertically upward. Compared with moving to the edge in the horizontal direction, the distance of arc movement in the vertical direction is significantly reduced. Under this structure, when there is a situation where the arc jumps from one metal contact lobe to another metal contact lobe along the Lorentz force direction, the jump distance in the overall jump direction is the width of the rectangle, so the distance is shorter, and only part of the arc jumps. Compared with traditional contacts, it still has the advantage of moving to the contact edge faster and has the ability to quickly increase the arc voltage.

[0043] like Figure 4 , 5Figure 6 shows a schematic diagram of a contact structure for increasing arc voltage under an external magnetic field according to the present invention. It includes a first metal contact lobe 4, a high-melting-point metal lobe 5, and two small opening slots 6 between the metal lobes. The contact surface is circular, divided into three contact lobes and two opening slots along a certain diameter. The area distribution ratio of the second metal contact lobe to the first metal contact lobe is 3:1. The direction of the external magnetic field is perpendicular to the direction of the divided contact lobes. This causes the external magnetic field to be parallel to the horizontal direction, resulting in the Lorentz force being in the vertical direction, causing the arc to move upwards or downwards to the contact edge. If the arc moves upward by a distance equal to 1 / 4 of the original contact surface of the first metal contact petal 4, upward by a distance equal to 1 / 2 of the original contact surface of the upper high-melting-point metal petal 5, and upward by a distance equal to 1 / 4 of the original contact surface of the lower high-melting-point metal petal 5, the distance the arc has to travel to the edge is reduced overall. Therefore, the arc can be lengthened quickly and the arc voltage can be increased. At the same time, due to the first metal contact petal 4, the probability of the arc starting on this contact petal is increased, thereby reducing the ablation area of ​​the entire contact plane.

[0044] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A contact structure for increasing arc voltage under an external magnetic field, comprising: A stationary contact (1) and a moving contact (2) are disposed on one side of the stationary contact (1) and are parallel to each other. The contact surfaces of the stationary contact (1) and the moving contact (2) are flat, and their non-contact surfaces are connected to the main circuit through a conductive rod (3). The feature is that it further includes: Two first metal contact petals (4) are symmetrically arranged on one side of the contact surface of the stationary contact (1) and the moving contact (2), and the first metal contact petals (4) are fixedly connected to the stationary contact (1) and the moving contact (2). Multiple second metal contact petals (5) are symmetrically arranged on the contact surfaces of the stationary contact (1) and the moving contact (2). The second metal contact petals (5) are fixedly connected to the stationary contact (1) and the moving contact (2). Multiple opening slots (6) are formed between adjacent second metal contact petals (5) and between the first metal contact petal (4) and the second metal contact petal (5). The multiple opening slots (6) are parallel to each other. The melting point of the second metal contact petal (5) is higher than that of the first metal contact petal (4). An external magnetic field is provided outside the stationary contact (1) and the moving contact (2). The magnetic field lines of the external magnetic field pass through the stationary contact (1) and the moving contact (2). The direction of the external magnetic field is parallel to the opening slot (6). The direction of the Lorentz force on the contact surface of the stationary contact (1) and the moving contact (2) is toward the side of the first metal contact flap (4).

2. The contact structure for increasing arc voltage under an external magnetic field according to claim 1, characterized in that, The total number of the first metal contact flap (4) and the second metal contact flap (5) is n, the number of the opening slots (6) is n-1, and the area of ​​the first metal contact flap (4) is less than or equal to the area of ​​the second metal contact flap (5).

3. The contact structure for increasing arc voltage under an external magnetic field according to claim 1, characterized in that, Two bases (31) are symmetrically provided on the non-contact surfaces of the stationary contact (1) and the moving contact (2). One side of the base (31) is fixedly connected to the stationary contact (1) and the moving contact (2) respectively, and the other side is fixedly connected to the conductive rod (3).

4. The contact structure for increasing arc voltage under an external magnetic field according to claim 1, characterized in that, The contact surfaces of the stationary contact (1) and the moving contact (2) are any one of rectangle, ellipse, circle, or rhombus, and the opening groove (6) is parallel to the long side of the rectangle, the long axis of the ellipse, and the long axis of the rhombus.

5. The contact structure for increasing arc voltage under an external magnetic field according to claim 1, characterized in that, The edges of the first metal contact petal (4) and the second metal contact petal (5) are located inside the edges of the stationary contact (1) and the moving contact (2), and the outer shapes of the first metal contact petal (4) and the second metal contact petal (5) are the same as the outer shapes of the stationary contact (1) and the moving contact (2).

6. The contact structure for increasing arc voltage under an external magnetic field according to claim 1, characterized in that, The external magnetic field is a permanent magnet or a coil, which is fixed on the outside of the stationary contact (1) and the moving contact (2).

7. The contact structure for increasing arc voltage under an external magnetic field according to claim 1, characterized in that, The first metal contact flap (4) is made of any one of pure copper, pure silver, or copper-silver alloy, and the second metal contact flap (5) is made of any one of pure tungsten or copper-tungsten alloy.

8. The contact structure for increasing arc voltage under an external magnetic field according to claim 1, characterized in that, The groove spacing of the opening groove (6) is 1mm-2mm.

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