Hybrid arc extinguishing circuit protection device

Abstract

The mixed arc extinguishing circuit protection device comprises an excitation source, a piston, a conductor, a melt and an arc extinguishing structure, one ends of the two melts are respectively connected to the conductor at a certain interval, the other ends, which are not connected with the conductor, of the two melts are not connected with each other, are exposed in the gaseous arc extinguishing medium and are insulated, and the piston is arranged corresponding to the conductor part between the two melts; the arc extinguishing structure is located on the outer side of the piston displacement path or the front end of the piston displacement path or the outer side and the front end of the piston displacement path. The excitation source can drive the piston to displace to disconnect a conductor part between the melts to form a fracture, the piston continues to displace to enable the melts located on the two sides of the fracture to be conducted under the action of an electric arc, and the conducted melts are fused under the action of current. The arc extinguishing capability and the breaking capability are improved through combination of arc extinguishing of the melt and arc extinguishing of the arc extinguishing structure.

Description

Technical Field

[0001] The present invention relates to the field of circuit protection, and in particular to a circuit protection device in the field of low-voltage electrical switches, which realizes circuit protection by mechanically disconnecting conductors. Background Art

[0002] With the rapid development of the new energy industry, especially the rapid development of the new energy automobile industry, the requirements for DC high voltage and high current short-circuit protection products, especially smart fuse products, are getting higher and higher, especially for the safety performance of battery packs. Smart fuses generally include an excitation source, a piston, and a conductor. The excitation source is a gas generating device. According to the triggering electrical signal, a reaction occurs to release high-pressure gas as a driving force. The conductor is used to be connected in series to the circuit to be protected. During operation, the excitation source releases high-pressure gas as a driving force to drive the piston to move, disconnect the conductor and thus disconnect the circuit to achieve circuit protection. However, when the conductor is disconnected, an arc will be generated. When the arc cannot be extinguished in time, it will cause a sustained arc, so that the circuit cannot be reliably disconnected. At present, in order to improve the arc extinguishing effect, an arc extinguishing grid is set in the excitation fuse, and the arc extinguishing grid is used to assist the arc extinguishing, or a fuse is connected in parallel to the conductor. After the conductor is disconnected, the current flows through the parallel fuse to limit the current and then fuse or mechanically disconnect to extinguish the arc. However, both of these arc extinguishing methods have certain defects. The reliability of the arc extinguishing grid solution decreases as the voltage and current increase; in the parallel fuse arc extinguishing solution structure, under normal working conditions, a small amount of current flows through the parallel fuse, causing power loss, and the structure is relatively complex. Summary of the invention

[0003] The object of the present invention is to provide a circuit protection device with mixed arc extinguishing, which realizes mixed arc extinguishing by combining an arc extinguishing grid structure (arc extinguishing metal wire) with a connected fuse, thereby improving arc extinguishing efficiency and breaking reliability.

[0004] To achieve the above-mentioned purpose, the technical solution of the present invention is a hybrid arc extinguishing circuit protection device, comprising an excitation source, a piston, a conductor, a melt and an arc extinguishing structure;

[0005] Along the current flow direction on the conductor, one end of the two fuses are connected to the conductor at a certain distance, and the other ends of the two fuses not connected to the conductor are not connected to each other, and are both exposed to the gaseous arc extinguishing medium and insulated;

[0006] The piston is arranged corresponding to the conductor part between the two melts, and the ends of the two melts not connected to the conductor are respectively located outside the displacement path after the piston disconnects the conductor, and the chambers where the ends of the two melts not connected to the conductor are located are connected chambers;

[0007] The arc extinguishing structure is located outside the piston displacement path, or located at the front end of the piston displacement path, or located at the outside and front end of the piston displacement path;

[0008] The excitation source can be actuated according to the received trigger electrical signal, driving the piston to displace and disconnect the conductor part between the two fuses to form a fracture. The continued displacement of the piston causes one end of the two fuse insulation devices located on both sides of the fracture to be conductive under the action of the electric arc, and the conductive fuse is melted under the action of the current.

[0009] Preferably, the arc extinguishing structure is one of an arc extinguishing grid, a metal wire mesh, a metal porous structure, or a combination of two or more structures.

[0010] Preferably, a pre-break is provided on the conductor, the piston is arranged corresponding to the pre-break of the conductor, the fuse is connected to both sides of the pre-break of the conductor respectively, and in the initial position, the two ends of the fuse on both sides of the pre-break that are not connected to the conductor are insulated.

[0011] Preferably, the pre-break opening is formed by providing a disconnection weak point on the conductor that can reduce the mechanical strength of the conductor, and the disconnection weak point runs through the width of the conductor.

[0012] Preferably, the disconnected weak point is a groove structure that runs through the width of the conductor, a variable cross-section structure, or an overlap structure connected by spot welding.

[0013] Preferably, the ends of the two melts that are not connected to the conductor are respectively suspended or supported by a supporting structure and exposed to the gaseous arc extinguishing medium; when the piston continues to move after disconnecting the conductor, the arc generated when the conductor is disconnected can be elongated under the drive of the piston, breaking through the ends of the two melts that are not connected to the conductor, so that the ends of the two melts that are insulated are conductive under the action of the arc.

[0014] Preferably, a limiting structure is provided on the periphery of the melt.

[0015] Preferably, the limiting structure is any one of a limiting hole, a limiting groove, and a clamping positioning component for the melt to pass through.

[0016] Preferably, a sealed cavity is formed between the high-pressure gas release end of the excitation source and the piston.

[0017] Preferably, the melt is provided with at least one narrow neck

[0018] The circuit protection device of the hybrid arc extinguishing of the present invention combines the connected fuse through the arc extinguishing grid (metal wire mesh for arc extinguishing) structure. After the conductor is disconnected, the arc is elongated by the piston, so that the fuses connected on both sides of the conductor break are connected in series, so that current flows through the fuses. When the temperature of the fuse rises to the melting temperature, the fuse melts and participates in arc extinguishing. At the same time, the elongated arc passes through the arc extinguishing structure and is extinguished by the arc extinguishing structure. Hybrid arc extinguishing is achieved through the fuse and the arc extinguishing structure, which improves arc extinguishing efficiency and breaking capacity.

[0019] When the circuit is in normal working condition, since one end of the fuse is connected to the broken side of the conductor and is not connected in parallel with the conductor, the fuse does not flow current. Only after the conductor is disconnected, the arc causes current to flow through the fuse. Therefore, under normal working conditions, no additional power loss will be added. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the principle structure.

[0021] Figure 2 yes Figure 1 Schematic diagram of the structure after the conductor is disconnected.

[0022] Figure 3 yes Figure 1 Schematic diagram of the structure in which the arc connects the melt on both sides of the break in series after the conductor is disconnected.

[0023] Reference numerals:

[0024] Excitation source 101 , piston 102 , conductor 103 , pre-break 107 , arc extinguishing structure 104 , melt 105 , arc 106 . DETAILED DESCRIPTION

[0025] The hybrid arc extinguishing circuit protection device of the present invention comprises an excitation source, a piston, a conductor, a fuse and an arc extinguishing structure; along the current flow direction on the conductor, one end of two fuses are respectively connected to the conductor at a certain distance, and the other ends of the two fuses not connected to the conductor are not connected to each other, and are both exposed to the gaseous arc extinguishing medium and insulated;

[0026] The piston is arranged corresponding to the conductor part between the two melts, and the ends of the two melts not connected to the conductor are respectively located outside the displacement path after the piston disconnects the conductor, and the chambers where the ends of the two melts not connected to the conductor are located are connected chambers;

[0027] The arc extinguishing structure is located outside the piston displacement path, or, located at the front end of the piston displacement path, or, located at the outside and front end of the piston displacement path;

[0028] The excitation source can be actuated according to the received trigger electrical signal, driving the piston to move to disconnect the conductor part between the two melts to form a fracture. The continued displacement of the piston causes one end of the two melt insulation devices on both sides of the fracture to be conductive under the action of the electric arc, and the conductive melt is melted under the action of the current.

[0029] The preferred embodiments are given below and described in detail with reference to the drawings. The directional words involved are only based on the directions shown in the drawings and do not constitute a limitation on the technical solution of the present invention.

[0030] See also Figures 1 to 3 The hybrid arc extinguishing circuit protection device of the present invention comprises a housing (not shown), and an excitation source 101, a piston 102, a conductor 103, a pre-break 107, a melt 105, and an arc extinguishing structure 104 located in the housing, wherein:

[0031] The excitation source 101 is a gas generating device that can be activated according to a triggering electrical signal to release high-pressure gas as a driving force.

[0032] The conductor 103, both ends of which can be connected in series to the circuit to be protected, when connected in series to the circuit to be protected, current flows through the conductor 103. A pre-break 107 is provided on the conductor 103, and the pre-break 107 is formed by providing a disconnection weak point on the conductor 103 that passes through the width of the conductor 103. The purpose of providing the disconnection weak point is to reduce the mechanical strength of the conductor, so that the piston can disconnect the conductor 103 from the disconnection weak point to form a break. The disconnection weak point can be a groove that passes through the width of the conductor on the conductor, the pre-break is set as a variable cross-section structure, or the conductor 103 is formed by overlapping two parts, and the disconnection weak point is formed by spot welding at the overlap, or the thickness of the conductor is thinned at the pre-break, etc.

[0033] The piston 102 is arranged on one side of the conductor 103 and is arranged opposite to the pre-break 107 of the conductor. The piston 102 is connected to the sealed cavity at the end where the driving force of the excitation source 101 is released. No matter in what direction and position the excitation source 101 is arranged, it is only necessary to meet the requirement that the high-pressure gas released by the excitation source 101 can reach the end face of the piston 102 and can drive the piston 102 to move toward the conductor, and disconnect the conductor 103 from the pre-break 107 of the conductor 103. Therefore, the piston 102 and the end where the high-pressure gas of the excitation source 101 is released can be directly connected through the sealed cavity, or through the air flow channel. In order to make the high-pressure gas released by the excitation source 101 act on the piston 102 to drive the piston 102 to move, and not leak to the end face of the piston 102 facing the conductor 103, thereby hindering the displacement of the piston 102, the outer periphery of the piston 102 is sealed in contact with the contact surface of the shell part or other parts in the shell, for example, by setting a sealing ring on the outer periphery of the piston 102. The arrangement of other components is based on the principle of not affecting the displacement of the piston 102 and disconnecting the conductor 103 .

[0034] The melt 105 is conductively connected to the conductor surface on both sides of the pre-break 107 of the conductor 103 and away from the piston 102, that is, the melt 105 is located on both sides of the displacement path after the piston 102 breaks the conductor 103. The specific connection mode of the melt 105 is as follows: one end of the two melts 105 is conductively connected to the conductor 103 located on both sides of the pre-break 107, and the other ends of the two melts 105 are not connected to each other, and are insulated away from the conductor 103 and are both exposed to the gaseous arc extinguishing medium. That is, one end of the two melts 105 connected to the conductor 103 is conducted through the conductor 103, and the ends of the two melts 105 not connected to the conductor 103 are insulated, and the insulated ends of the two melts 105 need to be located outside the displacement path after the piston 102 disconnects the conductor 103. At the same time, the piston 102 continues to displace after disconnecting the conductor 103. The arc generated after the conductor 103 is disconnected can break through the gaseous arc-extinguishing medium between the insulated ends of the two melts 105 as the piston 102 moves. The insulated ends of the two melts 105 are conducted through the arc, and the two conductor parts on both sides of the break re-establish a conductive series circuit through the two conducted melts. The current originally flowing through the conductor 103 flows through the conductor parts and the melt on both sides of the break, so that current flows through the two melts 105. Since the impedance between the two ends of the fuse 105 that are connected by the arc breakdown is much larger than that of the conductor 103, the current flowing through the fuse is much lower than the current flowing directly through the conductor 103, thereby achieving a current limiting effect. When current flows through the fuse, the fuse 105 melts under the action of the current, disconnecting the conductive series circuit again, consuming the arc energy and achieving arc extinguishing.

[0035] The ends of the two melts 105 that are not connected to the conductor 103 can be suspended or supported by a supporting structure. In order to ensure that the impact after the piston 102 disconnects the conductor 103 will not affect the initial position of the ends of the two melts 105 that are insulated, a limiting structure can be set on the outer peripheral side of the melt 105 inside the shell. Regardless of the setting of the limiting structure or the supporting structure, it must meet the following requirements: one end of the melt 105 that is insulated must be exposed in the gaseous arc-extinguishing medium, that is, located outside the limiting structure and the supporting structure, to ensure that the arc can break through the gaseous arc-extinguishing medium between the ends of the two melts 105 that are insulated, so that the ends of the two melts 105 that are insulated are conductive under the action of the arc. The limiting structure can be a limiting hole, a limiting groove, a clamping and positioning component, and other structures for the melt 105 to pass through.

[0036] During the assembly process, if no special treatment is done to the inside of the shell, there is a lot of air in the shell, and the fuse 105 is located in the air. Therefore, the gaseous arc-extinguishing medium that is broken down at one end of the insulation setting of the fuse 105 is air.

[0037] In order to improve the arc extinguishing efficiency, the shell can be sealed as a whole, and other gaseous arc extinguishing media other than air can be filled inside the shell. The other gaseous arc extinguishing media can be inert gas or other gas that can improve the arc extinguishing efficiency.

[0038] In order to speed up the melting speed of the melt 105 , at least one narrow neck may be provided on the melt 105 .

[0039] An arc extinguishing structure 104 is provided on the outer peripheral side of the end position of the piston 102. The arc extinguishing structure 104 may be an arc extinguishing grid structure, an arc extinguishing wire mesh structure, or other porous structures through which gas can pass and arc can flow.

[0040] The arc extinguishing structure 104 may also be disposed at the front end of the end position of the piston 102, or disposed at the outer peripheral side and the front end of the displacement path after the piston 102 disconnects the conductor.

[0041] How the arc extinguishing structure 104 is specifically arranged is specifically designed according to arc extinguishing requirements.

[0042] Working principle of the present invention:

[0043] Under normal working conditions, current flows through the conductor 103 , and the two fuses 105 are in an insulated and non-conductive state.

[0044] When a fault current (overload or short circuit) occurs, the excitation source 101 operates according to the trigger electrical signal, releasing high-pressure gas as a driving force. The high-pressure gas drives the piston 102 to move toward the conductor 103. When the piston 102 moves to the conductor 103, the conductor 103 is disconnected from the pre-break 107 on the conductor 103 to form a fracture, disconnecting the protection circuit in series with the conductor 103, and the piston 102 continues to move. When the piston 102 moves, the arc 106 generated when the conductor is disconnected is elongated along with the displacement of the piston. When the elongated arc approaches one end of the insulating device of the fuse 105 located on both sides of the fracture, it breaks through the gas between the two ends of the insulating device of the fuse 105. The arc extinguishing medium makes the two fuses 105 conductive, so that the two fuses 105 and the disconnected conductors are in series, forming a series circuit. Current flows through the fuses 105. Since the impedance between the two ends of the insulating arrangement of the fuses 105 is very high after breakdown, which is much higher than the impedance of the conductor 103, current limiting is formed. The fuses 105 are melted under the action of the current after current limiting, and part of the arc energy is consumed; at the same time, the elongated arc approaches the arc extinguishing structure 104, and part of the arc is extinguished by the arc extinguishing structure 104. At the same time, the gas with a higher temperature caused by the arc passes through the arc extinguishing structure with a porous structure, so that the gas temperature is reduced and the arc is cooled.

[0045] By combining the arc extinguishing of the fuse and the arc extinguishing structure, the arc can be extinguished quickly, the protection circuit can be disconnected reliably, the arc extinguishing efficiency can be improved, and the breaking capacity can be improved.

Claims

1. A hybrid arc extinguishing circuit protection device, characterized in that: It includes an excitation source, a piston, a conductor, a melt and an arc extinguishing structure; Along the current flow direction on the conductor, one end of the two fuses is connected to the conductor at a certain distance, and the other ends of the two fuses not connected to the conductor are not connected to each other, and are both exposed to the gaseous arc extinguishing medium and insulated; The piston is arranged corresponding to the conductor part between the two melts, and the ends of the two melts not connected to the conductor are respectively located outside the displacement path after the piston disconnects the conductor, and the chambers where the ends of the two melts not connected to the conductor are located are connected chambers; The arc extinguishing structure is located outside the piston displacement path, or located at the front end of the piston displacement path, or located at the outside and front end of the piston displacement path; The excitation source can be actuated according to the received trigger electrical signal, driving the piston to displace and disconnect the conductor part between the two fuses to form a fracture. The continued displacement of the piston causes one end of the two fuse insulation devices located on both sides of the fracture to be conductive under the action of the electric arc, and the conductive fuse is melted under the action of the current.

2. The circuit protection device according to claim 1, characterized in that: The arc extinguishing structure is one of an arc extinguishing grid, a metal wire mesh, and a metal porous structure, or a combination of two or more structures.

3. The circuit protection device according to claim 1, characterized in that: The conductor is provided with a pre-break, the piston is provided corresponding to the pre-break of the conductor, the fuses are connected to both sides of the pre-break of the conductor respectively, and in the initial position, the two ends of the fuses on both sides of the pre-break that are not connected to the conductor are insulated.

4. The circuit protection device according to claim 3, characterized in that: The pre-break opening is formed by being arranged on the conductor at a disconnection weak point which can reduce the mechanical strength of the conductor, and the disconnection weak point runs through the width of the conductor.

5. The circuit protection device according to claim 4, characterized in that: The disconnected weak point is a groove structure that runs through the width of the conductor, a variable cross-section structure, or an overlap structure connected by spot welding.

6. The circuit protection device according to claim 3, characterized in that: The ends of the two melts that are not connected to the conductor are respectively suspended or supported by a supporting structure and exposed to the gaseous arc extinguishing medium; when the piston continues to move after disconnecting the conductor, the arc generated when the conductor is disconnected can be elongated under the drive of the piston, breaking through the ends of the two melts that are not connected to the conductor, so that the ends of the two melts that are insulated are conductive under the action of the arc.

7. The circuit protection device according to claim 6, characterized in that: A limiting structure is arranged on the periphery of the melt.

8. The circuit protection device according to claim 7, characterized in that: The limiting structure is any one of a limiting hole, a limiting groove, and a clamping and positioning component for the melt to pass through.

9. The circuit protection device according to claim 1, characterized in that: A sealed cavity is formed between one end of the excitation source that releases high-pressure gas and the piston.

10. The circuit protection device according to claim 1, characterized in that: At least one narrow neck is arranged on the melt.

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