A single excitation source step-by-step action excitation protection device

Abstract

A single excitation source step action excitation protection device, comprising a shell, an excitation source, an impact device and a conductor; at least two impact devices are arranged in different cavities in the shell, one side of the impact device is provided with an excitation source, the impact device and the excitation source are in sealed contact with the cavity where they are located; the excitation source drives the impact device to displace simultaneously or in sequence, at least one impact device breaks the conductor during displacement. The excitation protection device of the application can be used for electric vehicle battery pack and load loop protection, or for other power control circuits. The excitation protection device of the application has excellent current impact resistance; arc extinguishing capacity is improved, fast protection can be realized; post-breakdown insulation performance is excellent; the sequence and time difference of multiple breaking points are widely adjustable, which is beneficial to the successful breaking and the improvement of breaking capacity of the excitation protection device; product reliability is improved.

Description

Technical Field

[0001] This invention relates to the fields of power control and electric vehicles, and in particular to an excitation protection device that interrupts current by disconnecting conductors in stages through an excitation source. Background Technology

[0002] Currently, in addition to traditional thermal fuses, electric vehicle battery pack protection devices have developed a structure that quickly cuts off the circuit, namely an excitation protection device, which is gradually expanding its application range. This is mainly to overcome the shortcomings of traditional fuses, such as high heat generation, high power consumption, large size and weight, limited resistance to current surges, long breaking time, and uncontrolled breaking process.

[0003] The excitation protection device generally consists of a housing, within which an excitation source, an impact device, and a conductor are sequentially arranged, with a pre-break on the conductor. Its working principle is as follows: When a fault current occurs in the main circuit of the battery pack, the excitation source in the excitation protection device, connected in series with the main circuit, is triggered. The excitation source generates high-pressure gas, which pushes the impact device downwards to break the pre-break on the conductor, creating a physical break in the conductor. Because the conductor of the excitation protection device is connected in series with the main circuit of the battery pack, the arc generated at the conductor break gradually cools and extinguishes in the air, cutting off the current and thus achieving the purpose of quickly disconnecting the circuit.

[0004] The earliest excitation protection devices consisted of a single excitation source, a single impact device, and a conductor with pre-breaks. While offering advantages such as good current surge resistance, low power consumption, and rapid breaking, they also suffered from drawbacks including low breaking capacity, insufficient arc extinguishing capability, and low breaking voltage. To address these shortcomings, researchers developed a system with a single excitation source, a single impact device, and a conductor with two or more pre-breaks. The order in which the two or more pre-breaks on the conductor break is controlled by adjusting the height of the punches on the impact device. This partially solves the problems of low breaking capacity, insufficient arc extinguishing capability, and low breaking voltage associated with a single pre-break, but it also has the following limitations: the order and time difference of breaking multiple pre-breaks are only adjusted by the height difference of the punches on a single impact device, resulting in few adjustable parameters and a small controllable range; during operation, the sequential breaking of pre-breaks by punches of different heights on the impact device leads to uneven stress on the entire device, making it prone to breakage and affecting breaking. Summary of the Invention

[0005] To address the aforementioned shortcomings, this invention designs a single-excitation-source, step-by-step excitation protection device. This device uses a single excitation source to drive at least two independent impact devices to simultaneously or sequentially cut off the conductor, thus disconnecting the circuit. Furthermore, a molten metal can be connected in parallel to the conductor, and the impact devices can sequentially disconnect the conductor and the molten metal, or one impact device can disconnect the conductor while another impact device disconnects the molten metal.

[0006] To achieve the above-mentioned technical objectives, the present invention provides a single-excitation-source step-by-step excitation protection device, comprising a housing, an excitation source, an impact device, and a conductor; at least two impact devices are disposed in different cavities within the housing, and an excitation source is disposed on one side of each impact device, with the impact device and the excitation source respectively in sealed contact with their respective cavities; the excitation source drives the impact devices to move simultaneously or sequentially, and at least one of the impact devices disconnects the conductor during the displacement process.

[0007] Preferably, at least one melt is connected in parallel with the conductor.

[0008] Preferably, at least one of the impact devices disconnects the conductor, at least one impact device disconnects the melt, or disconnects the conductor and the melt in sequence.

[0009] Preferably, the melt is provided with a melting weak point and a breaking weak point, wherein the breaking weak point is located at the part that is broken by the impact device.

[0010] Preferably, a pusher block is provided in the cavity near the impact device at the weak point of the melt break, and a limiting structure is provided between the pusher block and the cavity to limit the initial position of the pusher block.

[0011] Preferably, the weak point of the fusion is located in a sealed cavity filled with an arc-extinguishing medium.

[0012] Preferably, the cavity where the excitation source is located is connected to the cavity where each of the impact devices is located, so that when the excitation source is activated, the impact devices can be driven to activate simultaneously or sequentially; or the cavity where the excitation source is located is connected to the cavity where one of the impact devices is located, and the cavities where each of the impact devices is located are connected in series through flow channels, so that when the excitation source is activated, the impact devices can be driven to activate sequentially.

[0013] Preferably, when the cavities of each impact device are connected in series through a flow channel, the impact device that acts first opens the flow channel opening that connects the cavity of the impact device that acts immediately after it with its cavity through displacement.

[0014] Preferably, one of the impact devices is centrally located, and the other impact devices are arranged at intervals around the centrally located impact device.

[0015] Preferably, the impact device is arranged around the outside of the cavity where the excitation source is located.

[0016] Preferably, the impact devices located outside the central impact device are all ring-shaped structures, and are sequentially and spaced apart on the outer periphery of the central impact device.

[0017] Preferably, a notch is provided at the position of the annular structure corresponding to the conductor, and when the impact device of the annular structure is displaced and breaks the melt, the conductor is located in the notch.

[0018] Preferably, a sealing device for sealing the contact surfaces is provided between the impact device and the excitation source and their respective contact surfaces with the cavity.

[0019] Preferably, the housing further includes a melt shell disposed at its bottom, the melt passing through the melt shell, and its two ends passing through the melt shell and connected in parallel with the conductor; a cavity is formed on the melt shell for the impact device to disconnect the melt.

[0020] Preferably, an indicator device is provided on the housing and is in sealing contact with the housing, and a limiting mechanism is provided between the indicator device and the housing; the indicator device is connected to the cavity of one of the impact devices that operate simultaneously through a flow channel, or is connected to the cavity of the last impact device that operates sequentially through a flow channel; the opening position of the flow channel of the indicator device in the cavity of the impact device satisfies the following condition: after all impact devices have operated, the indicator device overcomes the displacement of the limiting mechanism under the driving force generated by the excitation source, and one end of the indicator device extends out of the housing.

[0021] Preferably, the excitation source is an electronic ignition device or a hydraulic device that can receive excitation signals and act accordingly; the electronic ignition device releases high-pressure gas, and the hydraulic device releases insulating high-pressure liquid.

[0022] The excitation protection device of the present invention has the following advantages compared with existing excitation protection devices:

[0023] Multiple impact devices are installed, and the impact devices operate in a step-by-step and orderly manner without affecting each other. The impact devices are subjected to more uniform force, resulting in higher reliability.

[0024] By rationally distributing the high-pressure gas generated by the excitation source, multiple impact devices can operate in a step-by-step and orderly manner, maximizing the effective use of the high-pressure gas's energy, reducing the possibility of gunpowder gas leaking into other chambers or to the outside, and avoiding the adverse effects caused by leakage.

[0025] The sequence and time difference of the actions of each impact device can be adjusted by adjusting multiple parameters such as the relative height position of the air guide hole, the cross-sectional area of ​​the air guide hole, the cross-sectional area of ​​the impact device chamber, and the stroke of the impact device. There are many adjustable parameters, and the adjustment range of the time difference can be widened by adjusting multiple parameters.

[0026] The excitation protection device of this invention has excellent resistance to current surges; improved arc extinguishing capability, enabling rapid protection; excellent post-break insulation performance; and a wide range of adjustable sequences and time differences for multiple breaks, which is beneficial for successful breaking and improved breaking capacity of the excitation protection device; thus enhancing product reliability. Attached Figure Description

[0027] Figure 1 This is a schematic cross-sectional view of the excitation protection device in the initial position, as shown in Example 1.

[0028] Figure 2 This is Example 1, at the initial position, with Figure 1 A schematic diagram of the cross-sectional structure of an excitation protection device with a vertical cross-sectional view.

[0029] Figure 3 This is a cross-sectional structural diagram of the excitation protection device after the first impact device is activated, as shown in Example 1.

[0030] Figure 4 This is Example 1, and... Figure 3 A cross-sectional schematic diagram of the excitation and protection device after the first impact device is activated, with the cross-sectional direction perpendicular to the direction of the cross-section.

[0031] Figure 5 This is a cross-sectional structural diagram of the excitation protection device after both the first and second impact devices have been activated, as shown in Example 1.

[0032] Figure 6 This is Example 1, and... Figure 5 A cross-sectional schematic diagram of the excitation protection device after both the first and second impact devices, which are perpendicular to the cross-sectional direction, have been activated.

[0033] Figure 7 This is Example 1. Figures 1 to 6 A schematic diagram of the second impact device in the diagram.

[0034] Figure 8 This is Example 1. Figures 1 to 6 A schematic diagram of the conductor and melt in the image.

[0035] Figure 9 This is a schematic cross-sectional view of the excitation protection device in the initial position, as shown in Embodiment 2.

[0036] Figure 10 This is a cross-sectional view of the excitation protection device after the first impact device is activated, as shown in Embodiment 2.

[0037] Figure 11 Example 2: Cross-sectional view of the excitation protection device after the second impact device is activated.

[0038] Figure 12This is a schematic cross-sectional view of the excitation protection device in the initial position, as shown in Embodiment 3.

[0039] Figure 13 This is a cross-sectional view of the excitation protection device after the first impact device is activated, as shown in Embodiment 3.

[0040] Figure 14 This is a cross-sectional structural diagram of the excitation protection device after the second impact device is activated, as shown in Example 3.

[0041] Figure 15 This is a schematic cross-sectional view of the excitation protection device in the initial position, as shown in Example 4.

[0042] Figure 16 This is a cross-sectional structural diagram of the excitation protection device after the first impact device is activated, as shown in Embodiment 4.

[0043] Figure 17 This is a cross-sectional view of the excitation protection device after the second impact device is activated, as shown in Example 4.

[0044] Figure 18 These are schematic diagrams of the conductor structures in Examples 2 to 4.

[0045] Figure 19 This is a structural schematic diagram of Example 5 under normal conditions.

[0046] Figure 20 This is a structural diagram of Example 5 after the entire action has been completed. Detailed Implementation

[0047] The preferred embodiments described above are illustrated in detail below. The structural positional relationships mentioned in this invention, such as up / down / left / right, above, below, left, right, forward, backward, etc., do not constitute a limitation of this invention. Example 1

[0048] See Figures 1 to 6 In this embodiment, the housing includes an upper housing 102 and a lower housing 106 that docks with it. The contact surfaces of the upper and lower housings 106 are sealed. The upper and lower housings are made of insulating material and can be entirely or partially injection molded. A conductor 105 is inserted between the contact surfaces of the upper and lower housings, with both ends of the conductor located outside the upper and lower housings respectively. When the excitation protection device is in use, the two ends of the conductor can be connected in series to an external circuit to protect it. Several cavities penetrating the contact surfaces of the upper and lower housings are respectively provided in the upper and lower housings. The conductor 105 has a long strip plate structure, and limiting protrusions 105a are provided on both sides of the conductor. The limiting protrusions are engaged in the corresponding limiting grooves on the lower housing to position the conductor.

[0049] The upper shell 102 is a hollow shell with two cavities inside. The first cavity 102b is located in the middle of the upper shell, and the second cavity is spaced apart on the outer periphery of the first cavity. The second cavity 102c has an annular structure. A gas flow channel is provided between the first and second cavities. The first and second cavities are respectively connected to the cavities of the lower shell. A conductor passes through the first cavity 102b.

[0050] A cavity for accommodating the excitation source 101 is formed at the top of the upper housing corresponding to the first cavity 102b, and the first cavity and the cavity accommodating the excitation source are completely connected. The excitation source 101 can be fixed to the upper housing by injection molding, or by installing the excitation source 101 through stepped holes in the cavity, and by fixing the excitation source with a pressure plate or cover (not shown) on the upper housing. The excitation source and its cavity are in sealed contact. The excitation source can receive excitation signals from the outside and act to generate a driving force to drive the first impact device. In this embodiment, the excitation source is an electronic ignition device, which can ignite according to the received excitation signal, and the chemicals inside react to release a large amount of high-pressure gas as the driving force.

[0051] The first impact device 103 is disposed in the first cavity 102b. An annular limiting protrusion 103a is provided on the top of the first impact device 103. The limiting protrusion is engaged with the top of the first cavity 102b and contacts the inner wall of the top of the upper housing, forming a limiting structure that defines the initial position of the first impact device. The initial position of the first impact device can also be defined by creating a groove in the cavity wall and providing a protrusion on the first impact device, allowing the protrusion to embed into the limiting structure within the groove. The top of the first impact device 103 is in sealed contact with the top of the upper housing. In the initial state, this seals the gas flow channel between the first cavity 102b and the second cavity 102c, separating them and preventing them from communicating. Only when the first impact device overcomes the limiting protrusion and moves towards the conductor direction, changing from sealed contact to unsealed contact with the top of the upper housing, does the gas flow channel become exposed, and the first and second cavities become connected. A groove is provided on the upper surface of the first impact device, and the excitation source is located in the area of ​​the groove, ensuring that the high-pressure gas released by the excitation source acts on the first impact device first.

[0052] Limiting grooves, penetrating the contact surfaces of the upper and lower shells, are formed on opposite side walls of the first cavity 102b. A slider is positioned at the location of the first impact device relative to the limiting grooves. The slider of the first impact device is embedded in the limiting grooves to form a guide device, ensuring linear displacement of the first impact device along the limiting grooves under the action of driving force and preventing its rotation. The first impact device and the first cavity are in sealed contact to prevent high-pressure gas from leaking from gaps, which could cause a reverse force to hinder the movement of the first impact device or cause a decrease in the pressure of the high-pressure gas, affecting the movement of the second impact device.

[0053] The impact end of the first impact device can be a blade-shaped structure, a pointed structure, such as a tapered contraction section structure, or other structures that are conducive to increasing the force per unit area.

[0054] Conductor 105 has a long strip-shaped plate structure, see [link / reference] Figure 8 At least one weak point 105b is provided on the conductor 105 to reduce the structural strength of the conductor. The weak point can be a groove formed on the surface of the conductor, for example... Figure 1 and Figure 3 The V-shaped groove can be a U-shaped groove or a groove of other structures; it can also be several through holes spaced apart in the width direction of the conductor, as long as it can reduce the structural strength of the conductor and facilitate the breaking of the conductor by the impact device. Bending weak points 105c are provided at certain intervals on both sides of the weak breaking point 105b. When the first impact device impacts the weak breaking point of the conductor, the conductor breaks at the weak breaking point. After breaking, under the action of the first impact device, it bends along the bending weak points, so that the bent parts of the conductor after breaking are located on both sides of the first impact device.

[0055] The second impact device 104 is fitted into the second cavity 102c, and the second impact device and the second cavity are in sealed contact. (See also...) Figure 7 In this embodiment, the second impact device 104 is a ring-shaped structure, with notches 104a extending through the impact ends of the second impact device on opposite sides of the ring-shaped structure. When the second impact device displaces through the conductor, the conductor is located at the notch of the second impact device, ensuring that the displacement of the second impact device does not affect the conductor. Several notches 104b are spaced apart near the end of the second impact device close to the excitation source. When the excitation source actuates and drives the first impact device to actuate, the first cavity and the second cavity connect as the first impact device displaces, allowing the high-pressure gas generated by the excitation source to enter the second cavity and drive the second impact device to displace. The second impact device can also be a ring-shaped structure of other shapes, such as elliptical or square.

[0056] A molten element 107 is connected in parallel below the conductor, and the molten element 107 is enclosed and installed in the lower housing by a bottom cover 108. The bottom cover is provided with a support structure to support the molten element. (See attached image) Figure 8 The melt 107 has a spatial geometric shape, formed by bending. Both ends of the melt are connected to the outer portions of the weak points of the conductor 105, meaning that after the conductor breaks, both ends of the melt are located on either side of the fracture. Several weak points and breakage points are formed on the melt; in this example, the weak points are narrow necks. For example... Figure 4In this design, the main body of the melt 107 is perpendicularly intersecting the conductor 105, with the melt spanning the conductor along its length and its two ends located outside the conductor's width. This arrangement ensures that the conductor is not affected when the second impact device breaks the melt. To achieve a conductive connection between the melt and the conductor, both ends of the connection are designed with curved structures, allowing for a parallel connection. The melt and conductor can be connected using bolt crimping, conductive spring connection, welding, or other methods. A cavity communicating with the second cavity is provided in the lower housing, facilitating the second impact device's movement to the melt to break it. The portion of the melt impacted by the second impact device is supported on both sides by the lower housing, facilitating the second impact device's breaking of the melt. A sealing cap 106a, with a bowl-shaped structure, is provided between the melt and the conductor. The sealing cap seals the space where the melt is located and also forms a cavity in the lower housing below the conductor for the broken portion to slide off and for the first impact device to displace after the conductor is broken. The cavity containing the melt is filled with an arc-quenching medium, which is arc-quenching sand or arc-quenching gel.

[0057] Working principle: When zero-current interruption or low-multiple fault current is required, the excitation source is triggered by an electrical signal to generate high-pressure gas. The high-pressure gas first drives the first impact device to move, pushing the first impact device to break the conductor and create a break. The arc current at the break point is completely transferred to the melt connected in parallel with the two ends of the weak break. Because the fault current is small, the heat generated at the narrow diameter of the melt is insufficient to melt the narrow diameter and extinguish the arc. During the movement of the first impact device, the first cavity and the second cavity gradually connect. The amount of high-pressure gas entering the second cavity gradually increases, filling the space between the upper notch of the second impact device and the top of the second cavity. When the amount of high-pressure gas accumulates to a certain level, it drives the second impact device to move downward along the second cavity, cutting off the melt. The arc cools down and extinguishes quickly, and the circuit is broken.

[0058] Under medium-multiple fault current, the excitation source is triggered by an electrical signal to generate high-pressure gas. The high-pressure gas first pushes the first impact device to break the conductor at the weak point, forming a break. The arc current at the break point is completely transferred to the melt connected in parallel with the two ends of the weak point. Due to the large fault current, heat is generated through the narrow diameter of the melt, and melting begins to occur at the narrow diameter of the melt. During the melting process, the first cavity and the second cavity gradually connect, and the amount of high-pressure gas entering the second cavity gradually increases, filling the space between the upper notch of the second impact device and the top of the second cavity. When the amount of high-pressure gas accumulates to a certain level, it drives the second impact device to move downward along the second cavity, cutting off the melt. The melting of the melt and the mechanical breaking of the break point work together to extinguish the arc and disconnect the circuit.

[0059] Under high fault current, the excitation source generates high-pressure gas triggered by an electrical signal. The high-pressure gas first enters the chamber of the first impact device, pushing the first impact device to break the conductor at the weak point and form a break. The arc-holding current at the break point is completely transferred to the molten material connected in parallel with the two ends of the weak point. Due to the large fault current, a large amount of heat is generated at the narrow diameter of the molten material and it melts rapidly. The arc-extinguishing medium participates in the arc extinguishing, and the arc is quickly extinguished. During the movement of the first impact device, the first cavity and the second cavity gradually connect. The high-pressure gas pushes the second impact device to cut the molten material, forming a clean physical break and ensuring insulation after the break. Example 2

[0060] See Figures 9 to 11 The system includes an upper housing 202 and a lower housing 206 sealed to it. A melt cover plate 209 and a bottom housing 211 for accommodating melt 210 are installed below the lower housing 206. A conductor 205 passes through the contact surface between the upper and lower housings. At least three mutually spaced cavities—a first cavity 203a, a second cavity 204a, and a closed third cavity 201a—are formed in the upper housing on the conductor side. The first cavities 203a and 204a penetrate the contact surface between the upper and lower housings and communicate with a fourth cavity 207a and a fifth cavity 208a formed in the lower housing. The conductor passes through the first cavity, the second cavity, and the fourth and fifth cavities. A first impact device 203 and a second impact device 204 are respectively provided in the first cavity 203a and the second cavity 204a. A certain gap is maintained between the top of the first impact device and the top of its respective cavity to allow high-pressure gas to enter and drive the impact device. The first and second impact devices are respectively in sealed contact with the cavity they are in. The sealing contact can be an interference fit, or a sealing device, such as sealing rings 203b and 204b, can be installed at the contact surface. Through the sealed contact design, the upper and lower chambers are completely separated, which can avoid the influence of high-pressure gas on the insulation capacity at the break and prevent the fault current in the lower chamber from being introduced into the drive circuit. At the same time, the high-pressure gas is independently sealed in the upper part, which can prevent the impact device from rebounding after it has moved into place.

[0061] The first and second impact devices are similar in shape to a T-shaped structure, with their impact ends being blade-shaped. An excitation source 201 is disposed at the top of the third cavity 201a. The excitation source 201 can be installed in the upper housing via injection molding or fixedly mounted in the third cavity using a stepped hole or similar method. The third cavity 201a is connected to the first cavity 203a via a first air passage 201b. The first air passage 201b is located in the gap between the top of the first impact device and the first cavity 203a to ensure that when the excitation source is activated, high-pressure gas can drive the first impact device to operate immediately. The third cavity is not connected to the second cavity. The second cavity 204a is connected to the first cavity 203a via a second air passage 212. The second air passage 212 is... Figures 9 to 11 As shown by the dotted lines, the second air passage can be one, two, or more, connecting to the second cavity from multiple directions within the first cavity. The opening of the second air passage 212 at the first cavity 203a is positioned appropriately below the top of the first impact device in its initial position. This position ensures that, before the first impact device is displaced (i.e., before disconnecting the conductor and the melt), the high-pressure gas generated by the excitation source will not enter the second cavity through the second air passage 212. This is to ensure that the high-pressure gas can effectively drive the first impact device to disconnect the conductor and the melt connected in parallel. The opening of the second air passage 212 in the second cavity is located at the gap between the top of the second impact device and the top of the second cavity, ensuring that the second impact device can be activated when the high-pressure gas enters the second cavity.

[0062] The initial positions of the first and second impact devices are limited by a limiting structure disposed between the first and second impact devices and their respective cavities. This limiting structure can be achieved by creating a groove in the cavity and a protrusion on the impact device, with the groove and protrusion engaging to achieve the limiting effect; alternatively, it can be achieved by creating a limiting step in the cavity and a limiting ridge on the impact device, with the limiting ridge engaging the limiting step to achieve the limiting effect; or by other locking and limiting methods. The top end faces of the first and second impact devices are designed as concave arc surfaces, which facilitates the movement of the impact devices by high-pressure gas. The lower punch of the impact device has a blade-like structure, which facilitates concentrated force to cut the conductor.

[0063] The fourth cavity 207a and the fifth cavity 208a of the lower shell are independently configured. The fourth cavity is connected to the first cavity, and the fifth cavity is connected to the second cavity. This ensures that the first and second impact devices can be displaced into the cavities of the lower shell after cutting the conductor to continue cutting the melt. The shapes of the fourth and fifth cavities are similar to those of the first and second impact devices, i.e., the upper cavities of the fourth and fifth cavities are relatively large. When the first or second impact device displaces and disconnects the conductor, it enters the fourth or fifth cavity, and the disconnected part of the conductor can be bent into the fourth or fifth cavity. The impact ends of the first and second impact devices are tightly fitted to their corresponding fourth and fifth cavities, respectively. This is to facilitate the dissipation of excess high-pressure gas impact energy and avoid shell rupture; at the same time, it can squeeze the arc, playing a certain auxiliary arc-extinguishing role.

[0064] The conductor 205 located in the fourth and fifth cavities is thinned, and then a break weak point 205a is formed at the thinned part of the conductor 205. A rotating weak point 205d is formed on one or both sides of the break weak point 205a. In embodiment 2, the rotating weak point is a reduced cross-section structure. When the first or second impact device is activated, the corresponding break weak point on the conductor can be cut off. After the conductor is broken, the break weak point can rotate and slide down along the rotating weak point. The break weak point facilitates the impact device to cut the conductor at a designated position, and the rotating weak point ensures that the conductor rotates along a predetermined trajectory after being broken. The break weak point and the rotating weak point can take the form of a "V" groove, a "U" groove, a reduced cross-section, or a pre-rolled opening, etc., to reduce strength. However, the structural strength of the rotating weak point must be higher than that of the break weak point to avoid adverse effects caused by the rotation weak point breaking during operation. See also... Figure 18 In addition to setting weak points for disconnection on the conductor, positioning holes 205b and positioning grooves 205c are also provided at both ends of the conductor inside the housing. These positioning holes and grooves cooperate with the housing to secure the conductor. Simultaneously, anti-misalignment grooves 205e and 205f are provided on both sides of the conductor's width. The different numbers or shapes of these anti-misalignment grooves on both sides prevent incorrect installation.

[0065] Vertical limiting grooves are provided on at least two opposite sides of the contact surfaces of the first and second impact devices in the cavity through which the displacement of the first and second impact devices occurs. The first or second impact device is provided with a corresponding slider, which is disposed in the limiting groove, so that the first and second impact devices can make linear displacement movements along the limiting groove, thereby preventing the first or second impact device from rotating.

[0066] After passing through the lower shell, the melt 210 is connected in parallel with the conductor. The connection points between the two ends of the melt and the conductor are located on the outside of the fourth cavity and the fifth cavity, respectively, so that the melt and the conductor are connected in parallel.

[0067] A melt cover plate 209 and a bottom shell 211 are fixedly installed at the bottom of the lower shell. The melt is sealed in the bottom shell by the melt cover plate and the bottom shell 211, and the bottom shell supports the melt. To better fix the melt, ribs 209a are provided on the cover plate to support the melt. The melt located outside the sixth cavity and the seventh cavity is further fixed on the ribs. The two ends of the melt pass through the cover plate and are electrically connected to the conductor. At the through hole where the melt passes through the cover plate, the gap between the melt and the cover plate is sealed by sealant or by setting a sealing ring in advance, thus sealing the internal space between the cover plate and the bottom shell. The structure of the melt can refer to the melt structure in Embodiment 1, which is a spatial geometric shape. The melt passes through the sixth cavity 211a and the seventh cavity 211b on the bottom shell. Weak points are opened on the melt located in the sixth cavity 211a and the seventh cavity 211b. The weak points can be punched holes, reduced cross-sections, etc. A first pusher block 207 and a second pusher block 208 are respectively installed in the sixth and seventh cavities located above the weak point of the melt break. The end faces of the first and second pushers that contact the melt are flat, and the first and second pushers respectively seal the sixth and seventh cavities containing the melt. The first and second pushers are fixed to their initial positions with the bottom shell by a limiting structure. When the impact device disconnects the conductor, it can drive the pushers to break the melt. In addition to the weak point of breakage, several narrow passages are also provided on the melt. The narrow passages can be located on the melt between the first and second pushers. A buffer pad (not shown) is provided at the bottom of the sixth and seventh cavities. When the impact device drives the pushers to break the melt, the buffer pad can absorb most of the kinetic energy brought by the pushers, preventing damage to the bottom shell. The cavity formed by the cover plate and the bottom shell is filled with an arc-extinguishing medium. The arc-extinguishing medium is arc-extinguishing sand or arc-extinguishing gel, and the melt is located in the arc-extinguishing medium. The cover plate, melt, and bottom shell are assembled as an independent part before being connected and fixed to the lower shell.

[0068] Working principle:

[0069] When zero-current interruption or low-multiple fault current is required, the excitation source is triggered by an electrical signal to generate high-pressure gas. The high-pressure gas first enters the first cavity through the first gas channel, pushing the first impact device to overcome the limiting structure and displace, breaking the conductor at the weak point to form a fracture. The arc-holding current at the fracture point is completely transferred to the molten metal connected in parallel with both ends of the weak point. Due to the small fault current, the heat generated at the narrow diameter of the molten metal is insufficient to melt the narrow diameter and extinguish the arc. The first impact device continues to move and cuts the molten metal, and the arc is quickly extinguished, breaking the circuit. Once the first impact device is in position, the second gas channel and the first gas channel are connected. The high-pressure gas flows through the first gas channel, the first cavity, and the second gas channel into the second cavity, where it circulates and accumulates. When the gas pressure is sufficient, it pushes the second impact device to sequentially break the conductor and the molten metal, forming a clean physical fracture and ensuring insulation after the break.

[0070] Under a medium-multiple fault current, the excitation source is triggered by an electrical signal to generate high-pressure gas. The high-pressure gas first enters the first cavity through the first gas channel, pushing the first impact device to break the conductor at the weak point, forming a break. The arc current at the break point is completely transferred to the molten metal connected in parallel with the two ends of the weak point. Due to the large fault current, heat is generated through the narrow diameter of the molten metal, and the narrow diameter of the molten metal begins to melt. During the melting process, the first impact device continues to move and cut the molten metal. At this time, the narrow diameter is not completely melted, and there may still be an arc at the first cut point of the molten metal. When the first impact device reaches its position, the second gas channel and the first gas channel are connected. The high-pressure gas flows through the first gas channel, the first cavity, and the second gas channel into the second cavity and accumulates. When the gas pressure is sufficient, it pushes the second impact device to sequentially break the conductor and the molten metal. The melting of the molten metal and the mechanical breaking of the break point work together to extinguish the arc and disconnect the circuit.

[0071] Under high fault current, the excitation source generates high-pressure gas triggered by an electrical signal. The high-pressure gas first enters the first cavity through the first air channel, pushing the first impact device to break the conductor at the weak point and form a break. The arc-holding current at the break point is completely transferred to the molten metal connected in parallel with the two ends of the weak point. Due to the large fault current, a large amount of heat is generated at the narrow diameter of the molten metal and it melts rapidly. The arc-extinguishing medium participates in the arc extinguishing, and the arc is quickly extinguished. The circuit is broken. The first impact device continues to move and cuts the molten metal in the absence of current. When the first impact device is in position, the second air channel and the first air channel are connected. The high-pressure gas flows through the first air channel, the first cavity, and the second air channel into the chamber of the second impact device and accumulates. When the gas pressure is sufficient, it pushes the second impact device to break the conductor and the molten metal in sequence, forming a clean physical break and ensuring insulation after the break. Example 3

[0072] The structure is modified from Example 2; see [link / reference]. Figures 12 to 14 In this embodiment, no sixth cavity is provided on the bottom shell 211 and the melt cover plate 209. The lower end face of the fourth cavity 207a cuts off the bottom of the lower shell 206. The first impact device 203 only needs to disconnect the conductor 205, and the second impact device 204 disconnects the conductor and the melt in sequence. However, in order to better fix the melt 210, a rib 209a for fixing the melt is added at the location where no sixth cavity is provided on the melt cover plate, and the shape of the melt is also slightly modified. Other structures are the same as in Embodiment 2.

[0073] Working principle: Excitation source 201 receives an external signal and generates high-pressure gas that enters the first cavity 203a through the first air passage 201a, driving the first impact device 203 to displace and disconnect the weak point of the conductor 205; the first air passage is connected to the second air passage 212, and the high-pressure gas enters the second cavity 204a, driving the second impact device 204 to disconnect the conductor and the melt in sequence. Example 4

[0074] Further modifications were made based on Example 3. See [link / reference] Figures 15 to 17 The melt is not connected in parallel. The melt cover plate and bottom shell are removed. A fourth cavity 307 and a fifth cavity 308 are opened on the lower shell 206. The fourth cavity 307 and the fifth cavity 308 do not penetrate the bottom of the lower shell. Other structures are the same as those in Embodiments 2 and 3.

[0075] Working principle: When the excitation source 201 is activated, high-pressure gas enters the first cavity 203a through the first air passage 201, driving the first impact device 203 to disconnect the conductor 205; the second air passage 212 is connected to the first air passage 201a, and high-pressure gas enters the second cavity 204a, driving the second impact device 204 to disconnect the conductor.

[0076] In embodiments 1 to 4 above, the impact device is not limited to two; multiple impact devices located in independent chambers can be provided. The excitation source can be directly connected to the cavities containing multiple impact devices through a first air passage. The impact devices in cavities directly connected to the excitation source are all first impact devices. The impact devices in cavities directly connected to the cavities containing the first impact devices through a second air passage are second impact devices, and the impact devices in cavities directly connected to the cavities containing the second impact devices through a third air passage are third impact devices, and so on. The air passages of the cavities containing the first, second, and third impact devices are connected in series. Therefore, the first, second, and third impact devices operate sequentially according to the order in which the high-pressure gas flows. As long as the high-pressure gas provided by the excitation source is sufficient to drive all impact devices to operate, theoretically, multiple impact devices that operate simultaneously or sequentially can exist. Example 5

[0077] Based on the excitation protection device structures of Embodiments 1 to 4 described above, an indicating device can also be added. See [link / reference] Figure 19 Taking Embodiment 1 as an example, a third cavity is formed in the upper shell outside the second cavity 102c. One end of the third cavity is open on the outer surface of the upper shell and communicates with the outside, while the other end is connected to the second cavity 102c through an air passage 102e. An indicator device 109 is interference-fitted in the third cavity. In this embodiment, the indicator device 109 has an inverted T-shaped structure, with its large-diameter end interference-fitted with the third cavity and located at the end connected to the air passage, and its small-diameter end located at the open end on the outer surface of the upper shell. A limiting mechanism is provided at the contact surface between the indicator device and the third cavity. In this embodiment, the limiting mechanism is an interference fit. The purpose of the limiting mechanism is to fix the indicator device in the third cavity and maintain its initial position, preventing the indicator device from malfunctioning and giving incorrect indications.

[0078] The opening position of the air passage 102e in the second cavity 102c is such that when the second impact device 104 disconnects the melt and moves to the dead point position, the opening of the air passage 102e in the second cavity 102c can be exposed. When the second impact device 104 has not moved to the dead point position, the opening of the air passage 102e in the second cavity 102c is closed by the second impact device.

[0079] Working principle of Example 5: After the first and second impact devices are fully displaced, the opening of the air passage 102e in the second cavity 102c is exposed. High-pressure gas enters the third cavity through the air passage 102e, driving the indicator device 109 to overcome the frictional force of the interference fit, causing one end of the indicator device to extend outside the excitation protection device housing and connect to the indicator circuit located outside the excitation protection device. The other end remains interference-fitted in the third cavity. By connecting the indicator device to the indicator circuit, a fault is indicated in the main circuit, indicating that the excitation protection device has completed its protection action and that the main circuit needs timely repair.

[0080] The purpose of the indicating device is to indicate the occurrence of a main circuit fault and to trigger the completion of the protection device's operation. Therefore, the indicating device only needs to be connected to the cavity containing the last impact device to operate through an air passage. When all impact devices operate simultaneously, the indicating device only needs to be connected to the cavity containing one of the impact devices through an air passage. The opening position of the air passage of the indicating device in the cavity containing the impact device must be such that the opening of the air passage of the indicating device can only be exposed after all impact devices have operated, and only then can the indicating device operate. Example 6

[0081] The cavity containing the excitation source can be connected to the cavities containing each impact device via air passages. When the excitation source receives an excitation signal and activates, the high-pressure gas it generates can simultaneously enter the cavities containing each impact device through the air passages, driving each impact device to activate simultaneously. Example 7

[0082] In embodiments 1 to 6 above, the excitation source is an electronic ignition device capable of generating high-pressure gas. In this embodiment, the excitation source is a hydraulic device capable of receiving external excitation signals. By receiving the excitation signal, it releases high-pressure liquid, which flows through the liquid channel (i.e., the gas channel in the above embodiments) into the cavity containing the corresponding impact device to drive the impact device to actuate. When a hydraulic device is used, the released high-pressure liquid must be an insulating liquid. In this embodiment, only the type of excitation source is changed; the rest of the structure is the same as in the above embodiments.

[0083] In this invention, the air passage in the above embodiments and the liquid flow passage in this embodiment are uniformly defined as flow passages.

Claims

1. A single-excitation-source step-by-step excitation protection device, comprising a housing, an excitation source, an impact device, and a conductor; characterized in that, At least two impact devices are disposed in different cavities within the housing. An excitation source is disposed on one side of each impact device. The impact device and the excitation source are in sealed contact with their respective cavities. The cavity containing the excitation source is connected to at least one cavity containing an impact device. The cavities containing impact devices that are connected to the cavity containing the excitation source, as well as the cavities containing each impact device that are not directly connected to the cavity containing the excitation source, are connected in series via flow channels. When the excitation source is activated, at least one impact device that activates first opens the flow channel connecting the cavity containing the impact device that activates immediately after it to its cavity through displacement. At least one impact device disconnects the conductor during displacement.

2. The excitation protection device with single excitation source and step-by-step operation according to claim 1, characterized in that, At least one melt is connected in parallel to the conductor.

3. The excitation protection device with single excitation source and step-by-step operation according to claim 2, characterized in that, At least one of the impact devices disconnects the conductor, at least one impact device disconnects the melt, or disconnects the conductor and the melt in sequence.

4. The excitation protection device with single excitation source and step-by-step operation according to claim 3, characterized in that, The melt is provided with a melting weak point and a breaking weak point, and the breaking weak point is located at the part that is broken by the impact device.

5. The excitation protection device with single excitation source and step-by-step operation according to claim 4, characterized in that, A pusher block is provided in the cavity near the impact device at the weak point of the melt break, and a limiting structure is provided between the pusher block and the cavity to limit the initial position of the pusher block.

6. The excitation protection device with single excitation source and step-by-step operation according to claim 4, characterized in that, The weak point of the fuse is located in a sealed cavity filled with an arc-extinguishing medium.

7. The excitation protection device with single excitation source and step-by-step operation according to claim 1, characterized in that, One of the impact devices is centrally located, while the other impact devices are arranged at intervals around the centrally located impact device.

8. The excitation protection device with single excitation source and step-by-step operation according to claim 1, characterized in that, The impact device is arranged around the outside of the cavity where the excitation source is located.

9. The excitation protection device with single excitation source and step-by-step operation according to claim 7, characterized in that, The impact devices located outside the central impact device are all ring-shaped structures, and are sequentially and spaced apart on the outer periphery of the central impact device.

10. The excitation protection device with single excitation source and step-by-step operation according to claim 9, characterized in that, The conductor is provided with a notch at the position of the annular structure. When the impact device of the annular structure is displaced and breaks the melt, the conductor is located in the notch.

11. The excitation protection device with single excitation source and step-by-step operation according to claim 1, characterized in that, A sealing device for sealing the contact surface is provided between the impact device and the excitation source and the contact surface of the cavity in which they are located.

12. The excitation protection device with single excitation source and step-by-step operation according to claim 2, characterized in that, The housing also includes a melt housing disposed at its bottom, the melt passing through the melt housing, and its two ends passing through the melt housing and connected in parallel with the conductor; a cavity is provided on the melt housing for the impact device to disconnect the melt.

13. The excitation protection device with single excitation source and step-by-step operation according to claim 1, characterized in that, An indicating device is provided on the housing and is in sealed contact with the housing. A limiting mechanism is provided between the indicating device and the housing. The indicating device is connected to the cavity of one of the impact devices that are operating simultaneously, or connected to the cavity of the last impact device that operates sequentially, through a flow channel. The opening position of the flow channel of the indicating device in the cavity of the impact device satisfies the following condition: after all impact devices have operated, the indicating device overcomes the displacement of the limiting mechanism under the driving force generated by the excitation source, and one end of the indicating device extends out of the housing.

14. The excitation protection device with single excitation source and step-by-step operation according to claim 1, characterized in that, The excitation source is an electronic ignition device or a hydraulic device that can receive excitation signals and act accordingly; the electronic ignition device releases high-pressure gas, and the hydraulic device releases insulating high-pressure liquid.

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