Combined arc extinguishing intelligent fuse

Abstract

The utility model provides a combined arc extinguishing intelligent fuse, comprising a conductor provided with a plurality of conductor pre-fractures; a melt electrically connected to both ends of at least one of the plurality of conductor pre-fractures; the arc extinguishing device is electrically insulated from the conductor; the trigger mechanism is used for pushing the cut-off device to cut off the conductor according to the trigger signal, and the cut-off device is an arc chute; and the connector is used for transmitting the trigger signal to the trigger mechanism. A first preset distance is kept between one end of the cutting device and the trigger mechanism, and a second preset distance is kept between the other end of the cutting device and the conductor pre-fracture. According to the utility model, the high-current breaking capacity can be improved, and the circuit can be ensured to be disconnected when the circuit is cut off under low current and no current, so that the breaking capacity and the arc extinguishing capacity are improved, and the safety of a protected system is ensured.

Description

Technical Field

[0001] This utility model belongs to the field of fuses, and in particular relates to a combined arc-extinguishing intelligent fuse. Background Technology

[0002] The statements in this section are merely to provide background information related to this utility model to aid in understanding it, and this background information does not necessarily constitute prior art.

[0003] Currently, circuit protection devices for new energy projects such as photovoltaics and energy storage typically use thermal fuses, which are characterized by simple structure, mature technology, high reliability, and strong high-current breaking capacity. However, they cannot meet the requirements for breaking small multiples of current. To address this, various pyrotechnic circuit breakers, also known as smart fuses, have emerged, using ignition tubes or miniature gas generators (MGGs) as excitation sources. These circuit breakers are triggered by an external system based on the magnitude of the fault current, actively cutting off the circuit and completing the disconnection action within milliseconds.

[0004] Since the trigger signal is generated by an external system based on the magnitude of the fault current, the current in the disconnected circuit could be a large current, a small current, or even the circuit could be disconnected when there is no current. Existing smart fuses, in order to eliminate the arc generated when disconnecting a circuit with a large current and thus improve the breaking capacity for large currents, typically connect a fusible element in parallel at the break point. However, the fusible element will not melt when there is a small current or no current, resulting in the circuit not being able to be disconnected under these conditions. Therefore, a smart fuse that can both improve the breaking capacity for large currents and disconnect the circuit under small current or no current is needed.

[0005] Chinese invention patent application CN112447462A discloses a multi-break excitation fuse capable of interrupting the circuit across its entire range, combining mechanical breaking and fusing. It includes a conductor with at least two breaks and an arc-extinguishing chamber filled with an arc-extinguishing medium. The fusible element is partially or completely housed within the arc-extinguishing chamber, with the melt-broken section located within it. The arc generated at the melt-broken section is extinguished in the arc-extinguishing medium, while smaller arcs at breaks connected in series are extinguished by air. This fuse still has room for further improvement. Utility Model Content

[0006] Therefore, the purpose of this utility model is to overcome the defects of the prior art and provide a combined arc-extinguishing intelligent fuse, comprising:

[0007] A conductor for carrying current, the conductor having multiple conductor pre-cuts to facilitate cutting the conductor;

[0008] A molten element, electrically connected to both ends of at least one of the plurality of conductor pre-breaks, is used to allow current to pass through to extinguish the arc when the conductor pre-break is broken;

[0009] An arc-extinguishing device, which is electrically insulated from the conductor, is used to extinguish an electric arc generated when at least one of the other pre-broken points of the plurality of conductors is disconnected;

[0010] The triggering mechanism is used to push the cutting device to move rapidly to the location of the multiple conductor pre-break points according to the triggering signal, so as to cut the conductor. The cutting device is an arc-extinguishing grid to extinguish a part of the electric arc while cutting the conductor.

[0011] Connectors are used to transmit trigger signals generated by external systems to the triggering mechanism;

[0012] Wherein, one end of the cutting device maintains a first preset distance from the triggering mechanism, and the other end maintains a second preset distance from the conductor pre-break; the first preset distance is greater than 0.1 mm and less than 3 mm, and the second preset distance is greater than 0.2 mm and less than 4 mm.

[0013] According to the combined arc-extinguishing intelligent fuse of this utility model, preferably, the triggering mechanism is an ignition tube or a micro gas generator.

[0014] According to the combined arc-extinguishing intelligent fuse of this utility model, preferably, the cutting device is made of insulating material and is configured to keep the conductor in an open state after cutting the conductor.

[0015] According to the combined arc-extinguishing intelligent fuse of this utility model, preferably, the cutting device has a plurality of blade-shaped protrusions, each corresponding to each of the plurality of conductor pre-break points, so as to quickly cut the conductor from the conductor pre-break point.

[0016] According to the combined arc-extinguishing intelligent fuse of this utility model, preferably, the length of the protrusion on the cutting device used to cut the conductor pre-break corresponding to the molten body is greater than the length of the protrusion used to cut the conductor pre-break corresponding to the arc-extinguishing device.

[0017] According to the combined arc-extinguishing intelligent fuse of this utility model, preferably, the arc-extinguishing device is a wire mesh or an arc-extinguishing grid.

[0018] According to the combined arc-extinguishing intelligent fuse of this utility model, preferably, the conductor pre-break is formed by removing a portion of material from the conductor, thereby reducing the cross-sectional area of ​​the conductor at that location.

[0019] According to the combined arc-extinguishing intelligent fuse of this utility model, preferably, the insulating material is PA66, PA6, PPSU, PPA or PC.

[0020] Compared with the prior art, the advantages of this utility model are: by combining the arc extinguishing device with the arc extinguishing device such as molten material and wire mesh or arc extinguishing grid, the arc extinguishing can be combined to improve the ability to interrupt large currents and ensure the ability to disconnect the circuit when there is no current or when the circuit is cut off, thereby improving the total current interrupting capacity and arc extinguishing capacity, and ensuring the safety of the protected system. Attached Figure Description

[0021] The embodiments of this utility model will be further described below with reference to the accompanying drawings, wherein:

[0022] Figure 1 This is a structural schematic diagram of a combined arc-extinguishing intelligent fuse according to an embodiment of the present utility model. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments given in this utility model are for illustrative purposes only and do not limit the scope of protection of this utility model.

[0024] The inventors discovered that there are a large number of inductances in energy storage, photovoltaic and other systems, and a large amount of energy accumulates in the circuit. Especially when the circuit is broken by a large current, the arc at the break point connected in series with the fuse in Chinese invention patent application CN112447462A is not effectively extinguished by air alone and cannot eliminate the arc generated there. If no effective measures are taken, the circuit cannot be broken normally, which will lead to product damage.

[0025] Therefore, this utility model adopts a combined arc extinguishing method, aiming to solve the problem that existing smart fuses connect fuse elements in parallel at the pre-break point in order to improve the breaking capacity of large currents, which leads to the inability to disconnect the circuit under small currents and no fault currents. It provides a smart fuse that can safely and reliably disconnect in the full current range, suitable for systems with a large amount of inductance such as energy storage and photovoltaics.

[0026] like Figure 1 As shown, the intelligent fuse of this invention includes a conductor 10, on which two conductor pre-break points 4 are provided. Depending on the breaking performance requirements, more than two conductor pre-break points 4 can also be provided. At least one of the conductor pre-break points 4 is connected in parallel with a fusible element 5, and an arc-extinguishing device 6 is correspondingly provided with at least one of the other conductor pre-break points 4 and is electrically insulated from the conductor 10. A cutting device 3 is provided adjacent to the conductor in a direction perpendicular to the conductor 10, and a triggering mechanism 2 is provided on the side of the cutting device 3 away from the conductor. The triggering mechanism 2 is coupled to a connector 1.

[0027] Conductor 10 is used to carry current. In order to carry large currents, its material is generally a low resistivity metal such as copper, brass, aluminum, silver, copper-silver, or copper-aluminum.

[0028] To enable the conductor 10 to be cut quickly, a portion of material is removed from it, reducing the cross-sectional area at that point and forming a conductor pre-break 4. Preferably, the conductor pre-break 4 is located on the side of the conductor 10 opposite to the cutting device 3. The pre-break 4 can be V-shaped, with its tip pointing towards the cutting device 3. Alternatively, the pre-break 4 can also be U-shaped or other groove shapes, or a combination of various groove shapes.

[0029] The molten element 5 is used to allow current to pass through when the conductor pre-break 4 is opened, thereby extinguishing the arc. Specifically, when the fault current is a large current, the arc-extinguishing device 6 extinguishes the arc generated at its corresponding pre-break 4, while the arc generated at the pre-break 4 corresponding to the molten element 5 flows through the molten element 5, causing the molten element 5 to open and extinguish the arc. When the fault current is a small current, the conductor pre-break 4 on the conductor 10 is cut off, the arc generated at at least one conductor pre-break 4 is extinguished by the arc-extinguishing device 6, and the current that is broken at at least one other pre-break 4 flows through the molten element 5 and is consumed by it.

[0030] The arc-extinguishing device 6 is used to extinguish the electric arc at at least one corresponding conductor pre-break 4. This prevents the energy accumulated in the circuit due to the large inductance present in energy storage, photovoltaic, and other systems from generating an arc that air cannot extinguish when a large current disconnects the circuit, leading to product explosion and failure to disconnect safely. The arc-extinguishing device 6 is electrically insulated from the conductor 10. Because the conductor pre-break 4 corresponding to the arc-extinguishing device 6 has been cut, it ensures that even if the fusible element 5 does not melt, the circuit remains open when the conductor pre-break 4 on the conductor 10 is disconnected by a small fault current or a fault-free current, thus ensuring system safety. The arc-extinguishing device can be a wire mesh, arc-extinguishing grid, etc.

[0031] The function of the cutting device 3 is to cut the conductor 10, changing the conductor 10 from a conductive state to an open state at the conductor pre-break 4, and maintaining this open state. Therefore, the cutting device 3 can be made of synthetic insulating materials such as PA66, PA6, PPSU, PPA, and PC. To ensure the safety and reliable cutting of the conductor 10, one end of the cutting device 3 adjacent to the triggering mechanism 2 maintains a first preset distance from the triggering mechanism 2. The first preset distance is preferably greater than 0.1 mm and less than 3 mm. When the first preset distance is within the preferred range, it can reduce the pressure of the gas generated when the triggering mechanism explodes on its chamber, while ensuring that sufficient pressure is generated to push the cutting device 3 to cut the conductor 10. The other end adjacent to the conductor maintains a second preset distance from the conductor pre-break 4. The second preset distance is preferably greater than 0.2 mm and less than 4 mm. When the second preset distance is within the preferred range, it can prevent the cutting device from being deformed and compressing the conductor during abnormal use, causing the conductor 10 to deform or even break at the pre-break 4, and at the same time prevent tilting during the cutting of the conductor 10, which would prevent the conductor 10 from being cut. The setting of the first and second preset distances further ensures that the product's cutting device can be equipped with multiple blade-shaped protrusions, each corresponding to a conductor pre-break 4 on the conductor 10. Preferably, the length of the protrusion used to cut the conductor pre-break 4 corresponding to the melt 5 is greater than the length of the protrusion used to cut the conductor pre-break 4 corresponding to the arc extinguishing device 6. This ensures that the conductor pre-break 4 corresponding to the melt 5 breaks first, allowing the arc to be mainly extinguished by the melt 5, thus better improving the high-current breaking capacity. Furthermore, for systems with a large number of inductors, such as energy storage and photovoltaic systems, an arc-extinguishing grid is preferably used in the cutting device 3 to further achieve safe arc extinguishing. In this way, the cutting device 3 can extinguish a portion of the arc while cutting the conductor 10, improving the arc extinguishing effect and ensuring circuit safety.

[0032] The triggering mechanism 2 can be one or both of an ignition tube or a micro gas generator. After being powered on, it can quickly generate a large amount of gas, which pushes the cutting device 3 to move rapidly to the position of the conductor pre-break 4 to cut the conductor 10.

[0033] Connector 1 is used to couple a trigger signal generated by an external system to trigger mechanism 2, so that when the external system (not shown) detects an abnormality and sends a signal, the signal can be transmitted to trigger mechanism 2 and trigger it, thereby driving the cutting device 3 to cut conductor 10.

[0034] The working principle of this invention is explained below. When an external system detects an anomaly and generates a trigger signal, the trigger signal is transmitted to the triggering mechanism 2 through connector 1. The gas generated by the triggering mechanism 2 pushes the cutting device 3 to move rapidly towards the position of the conductor pre-break 4, cutting the conductor 10 to form a break. When the current flowing through the conductor 10 is a large current, the arc generated at the pre-break 4 corresponding to the arc extinguishing device 6 is extinguished by the arc extinguishing device, and the arc generated at the pre-break 4 corresponding to the fusible element 5 flows through the fusible element 5, causing the fusible element 5 to melt and thus extinguish the arc at that point. At this time, the circuit remains open at both the break point corresponding to the arc extinguishing device 6 and the break point corresponding to the fusible element 5. Therefore, this intelligent fuse has a high current breaking capacity. When the current flowing through conductor 10 is small, the arc generated at the pre-break point 4 corresponding to the arc-extinguishing device 6 is extinguished by the arc-extinguishing device 6. The current interrupted at the pre-break point 4 corresponding to the fusible element 5 flows through and is consumed by the fusible element 5. At this time, the fusible element usually does not melt, and the circuit at this point remains connected. However, since the circuit at the pre-break point 4 corresponding to the arc-extinguishing device 6 is open, the entire circuit remains open. Therefore, this intelligent fuse has a small current breaking capacity. When no current flows through conductor 10, the circuit at the pre-break point 4 corresponding to the fusible element 5 remains connected due to the presence of the fusible element 5. However, the circuit at the pre-break point 4 corresponding to the arc-extinguishing device 6 is open. Therefore, the entire circuit remains open. Thus, this intelligent fuse still has a breaking capacity when there is no current.

[0035] This utility model of a combined arc-extinguishing intelligent fuse uses a combination of a fusible element and an arc-extinguishing device such as a wire mesh or arc-extinguishing grid to extinguish arcs. It can simultaneously improve the breaking capacity of high currents and ensure circuit disconnection when the circuit is cut off by low current or no current, thereby improving the breaking capacity and arc-extinguishing capacity and ensuring the safety of the protected system.

[0036] Although the present invention has been described through preferred embodiments, the present invention is not limited to the embodiments described herein, and includes various changes and variations without departing from the scope of the present invention.

Claims

1. A combined arc-extinguishing intelligent fuse, characterized in that, A conductor (10) for carrying current, the conductor (10) having a plurality of conductor pre-cuts (4) for facilitating cutting of the conductor (10); The melt (5) is electrically connected to both ends of at least one of the plurality of conductor pre-breaks (4) for allowing current to pass through to extinguish the arc when the conductor pre-break (4) is broken; Arc extinguishing device (6), which is electrically insulated from the conductor (10), is used to extinguish the arc generated when at least one of the other conductor pre-breaks (4) is disconnected; Triggering mechanism (2) and cutting device (3), wherein the triggering mechanism (2) is used to push the cutting device (3) to move rapidly to the location of the plurality of conductor pre-breaks (4) according to the triggering signal, so as to cut the conductor (10), and the cutting device (3) is an arc-extinguishing grid to extinguish a portion of the arc while cutting the conductor (10); Connector (1) is used to transmit trigger signals generated by an external system to the triggering mechanism (2); Wherein, one end of the cutting device (3) maintains a first preset distance from the triggering mechanism (2), and the other end maintains a second preset distance from the conductor pre-break (4); the first preset distance is greater than 0.1 mm and less than 3 mm, and the second preset distance is greater than 0.2 mm and less than 4 mm.

2. The combined arc-extinguishing intelligent fuse according to claim 1, characterized in that, The triggering mechanism (2) is an ignition tube or a micro gas generator.

3. The combined arc-extinguishing intelligent fuse according to claim 1, characterized in that, The cutting device (3) is made of insulating material and is configured to keep the conductor (10) disconnected after it is cut.

4. The combined arc-extinguishing intelligent fuse according to claim 1, characterized in that, The cutting device (3) has a plurality of blade-shaped protrusions, each corresponding to one of the plurality of conductor pre-breaks (4), to quickly cut the conductor from the conductor pre-break (4).

5. The combined arc-extinguishing intelligent fuse according to claim 4, characterized in that, The length of the protrusion on the cutting device (3) used to cut the conductor pre-break (4) corresponding to the melt (5) is greater than the length of the protrusion used to cut the conductor pre-break (4) corresponding to the arc extinguishing device (6).

6. The combined arc-extinguishing intelligent fuse according to any one of claims 1-5, characterized in that, The arc-extinguishing device (6) is a wire mesh or an arc-extinguishing grid.

7. The combined arc-extinguishing intelligent fuse according to any one of claims 1-5, characterized in that, The conductor pre-break (4) is formed by removing a portion of material from the conductor to reduce the cross-sectional area of ​​the conductor at its location.

8. The combined arc-extinguishing intelligent fuse according to claim 3, characterized in that, The insulating material is PA66, PA6, PPSU, PPA, or PC.

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