WO2022121230A1

WO2022121230A1 - Multibreak excitation fuse having grouped breaking

Info

Publication number: WO2022121230A1
Application number: PCT/CN2021/092736
Authority: WO
Inventors: 段少波; 石晓光; 戈西斌; 王欣
Original assignee: 西安中熔电气股份有限公司
Priority date: 2020-12-11
Filing date: 2021-05-10
Publication date: 2022-06-16
Also published as: CN112447463A

Abstract

A multibreak excitation fuse having grouped breaking, comprising a housing, a conductor, an excitation device and a breaking device. The breaking device is able to break the conductor under the driving of the excitation device. At least one cut-off structure capable of cutting off the conductor is arranged in a cavity on the other side of the conductor. Two groups of breaking weak points are arranged at intervals along the length direction of the conductor located in the housing. After the breaking device breaks the conductor off from the first break-off weak point group, at least one break-off conductor portion that can be disengaged from an original position is formed, to form a first group of breaks, and the second break-off weak point group is disposed on the break-off conductor portion. When the break-off conductor portion is displaced to the position of a cut-off structure, the cut-off structure breaks off the break-off conductor portion from the second break-off weak point group to form a second group of breaks. The first group of breaks at least comprises two breaks, and the second set of breaks at least comprises one break. The present excitation fuse structure is able to improve breaking ability and arc extinguishing ability.

Description

A multi-break excitation fuse with group disconnection

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims the priority of the Chinese Patent Application No. 2020114610446 and entitled "Multi-Break Excitation Fuse with Group Disconnection" filed with the Chinese Patent Office on December 11, 2020, the entire contents of which are incorporated by reference in in this disclosure.

technical field

The present disclosure relates to the field of electric power, and in particular, to a multi-break excitation fuse for group disconnection.

Background technique

Products used for circuit overcurrent protection are fuses that are blown based on the heat generated by the current flowing through the fuse. The main problem is how to select a thermal fuse that matches the load. For example, in the case of protecting the main circuit of a new energy vehicle, if the load has a low multiple overload or short circuit, selecting a fuse with a low current specification cannot prevent the current from overshooting in a short time. If a fuse with a high current specification is selected, it cannot meet the fast protection requirements. At present, the output current of lithium battery packs that provide energy to new energy vehicles is about several times the rated current under short-circuit conditions. circuit devices, causing the battery pack to heat up and catch fire. The melting caused by the heating of the withstand current and the heating of the breaking current is caused by the current flowing through the fuse. Under the condition of inrush current (such as short-term high current when electric vehicle starts or climbing a slope), the fault current of a certain amplitude can be broken at a fast enough breaking speed, or the fault current of a certain amplitude cannot be broken at a fast enough breaking speed , can also achieve higher rated current, or withstand larger overload/impulse current without damage.

Another problem with thermal fuses is that they cannot communicate with external devices and cannot be triggered by signals other than current, such as signals from vehicle ECU, BMS or other sensors. If the circuit cannot be cut off in time when the vehicle is in a serious collision, soaked in water, or the battery temperature is too high after exposure, it may lead to serious incidents that the battery pack will burn and eventually damage the vehicle.

At present, there is a structure for quick disconnection and opening on the market, which mainly includes a gas generating device, a conductive terminal, and an accommodating cavity configured to receive the dropped conductive terminal. The gas generating device generates high-pressure gas to drive the interrupting device to break Conductive terminals, the broken conductive terminals drop down into the accommodating cavity to achieve the purpose of quick disconnection of the circuit.

However, the above-mentioned quick-breaking cut-off opening structure still has some deficiencies and defects: a single fracture has insufficient arc extinguishing ability, and can only interrupt a small fault current, and it is difficult to interrupt a large fault current. The larger the arc current, the more difficult it is to extinguish. All the arcs are concentrated on one fracture. The arc heats the copper bar and the air, which is easy to be self-sustaining and cannot be extinguished. That is, the arc will not be extinguished immediately after it is generated. When the state is stable, the fracture is When the distance is stable, the voltage is stable, and the current is stable, the arc will continue. In the breaking process of the above-mentioned fuse with a cutting opening structure, the arc is directly cooled by air, and there is no other structure or mechanism to assist the arc extinguishing. In addition, a single fracture can generally only work in an environment with a voltage of 500V and below, and it is difficult to achieve breaking in an environment above 500V, because the higher the voltage, the easier it is to form an arc between the fractures, and the arc is more likely to be self-sustaining.

SUMMARY OF THE INVENTION

The purpose of the present disclosure is to provide a group-disconnected multi-break excitation fuse to improve at least one of the above problems.

An embodiment of the present disclosure provides a multi-break energizing fuse disconnected in groups, including a housing, a cavity is opened in the housing, a conductor is passed through the housing, and the cavity is divided into Two parts, an excitation device and an interruption device are sequentially arranged in the cavity on one side of the conductor, and the interruption device is driven by the excitation device to interrupt the conductor; the cavity on the other side of the conductor At least one cutting structure that can cut off the conductor is arranged inside; two groups of weak points for breaking are arranged at intervals along the length direction of the conductor located in the casing; At least one disconnected conductor part that can be disengaged from the original position is formed after the conductor is disconnected at the weak point to form a first group of fractures, and the second group of disconnected weak points is arranged on the disconnected conductor part; when the disconnection When the conductor part is displaced to the cut-off structure, the cut-off structure cuts the cut-off conductor part from the second group of broken weak points to form a second group of fractures, and the first group of fractures includes at least two A fracture, the second group of fractures includes at least one fracture.

Optionally, driven by the excitation device, the breaking device can first break the first group of weak points on the conductor, and then cooperate with the cutting structure in the housing to break the second group of weak points on the conductor, and then break the second group of weak points on the conductor. Grouping to form fractures.

Optionally, on the end face of the breaking device located on one side of the conductor, corresponding to the second group of broken weak points of the conductor, cavities are respectively opened, and the cavities are provided with an arc extinguishing medium or Arc extinguishing structure.

Optionally, the arc-extinguishing medium is gas, liquid or solid particulate matter, and the arc-extinguishing medium is sealed in the cavity through a sealing plate; After the second group of weak points is broken, the cutting structure can break the sealing plate.

Optionally, the arc extinguishing structure is an arc extinguishing grid.

Optionally, an arc-extinguishing chamber is provided on the inner wall of the casing through which the disconnected conductor portion is displaced to the cutting structure, and a solidified arc-extinguishing medium or an arc-extinguishing grid can be arranged in the arc-extinguishing chamber.

Optionally, the cutting structure is a rib.

Optionally, one or more combinations of grooves and holes for reducing conductor strength, reducing conductor width to concentrate stress, and materials with lower strength than the conductor material are used for the disconnected weak point.

Optionally, at least one melt is connected to the conductor in the housing.

Optionally, both ends of the melt are connected to a conductor in parallel, and all disconnected weak points on the conductor are located between the two ends of the melt.

Optionally, in the casing, one end of the melt is connected to the outside of the outermost one or two disconnected weak points, and the other end of the melt is located outside the cut structure; When the disconnected conductor portion is displaced to a position close to the cutting structure and is not disconnected, the disconnected conductor portion can be connected to an end of the melt located outside the cutting structure.

Optionally, a melt is provided at the cut-off structure; when the cut-off conductor part is displaced to a position close to the cut-off structure and is not cut off, the cut-off conductor part is located at both ends of the weak point on the cut-off conductor part Can be connected to both ends of the melt.

Optionally, the excitation device comprises a gas generating device.

Optionally, the breaking device is provided with a plurality of impact heads at intervals.

Optionally, the arc-extinguishing structure includes a solid non-granular arc-extinguishing substance.

In addition, an embodiment of the present disclosure provides a power distribution unit, the application including the excitation fuse described in any one of the above.

In addition, an embodiment of the present disclosure provides an energy storage device, the application including the excitation fuse described in any one of the above.

In addition, an embodiment of the present disclosure provides a new energy vehicle, the application includes the excitation fuse described in any one of the above.

Description of drawings

In order to illustrate the technical solutions of the present disclosure more clearly, the following drawings will be briefly introduced. It should be understood that the following drawings only show some implementations of the present disclosure, and therefore should not be regarded as It is a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is the structural schematic diagram of the longitudinal section without arc extinguishing medium;

Fig. 2 is the structural schematic diagram after the formation of the first group of fractures of the structure of Fig. 1;

Fig. 3 is the structural representation after the formation of the second kind of fracture of the structure of Fig. 1;

4 is a schematic structural diagram of a longitudinal section with an arc extinguishing medium;

Fig. 5 is the structural schematic diagram after the formation of the first group of fractures of the structure of Fig. 4;

Fig. 6 is the structural representation after the formation of the second kind of fracture of the structure of Fig. 4;

FIG. 7 is a schematic view of the structure of conductors with melts connected in parallel, and between the melts and the rib, and F in the figure represents the melt. Among them, there are a total of five structural schematic diagrams of ABCDE melt parallel solutions;

Fig. 8 is the structural schematic diagram after the melt is connected with the disconnected conductor part, wherein A is the scheme A, B is the scheme B; F represents the melt;

Fig. 9 is the circuit schematic diagram of scheme A and scheme B, wherein, A is scheme A, B is scheme B; F represents melt.

Reference numerals: 101-upper casing; 102-exciting device; 103-interrupting device; 104-conductor; 105-lower casing; 107-breaking weak point; 108-impact head; Disconnect the conductor part; 110 - ridge; 112 - arc extinguishing structure; 111 - arc extinguishing melt.

Detailed ways

In view of the above technical solutions, embodiments are now given and described in detail with reference to the drawings. The excitation fuse (also referred to as a trigger fuse) proposed in the embodiments of the present disclosure mainly includes a housing, a conductor 104, an excitation device 102 (also referred to as a trigger device), and an interruption device 103.

As shown in FIG. 1 to FIG. 3 , the casing can be composed of upper and lower casings or left and right casings. In this embodiment, the upper casing 101 and the lower casing 105 are combined as an example for description. A cavity is opened in the shell. The conductor 104 is inserted between the upper and lower casings, and divides the cavity in the casing into two parts. An excitation device 102 and an interruption device 103 are sequentially arranged in the cavity on one side of the conductor 104 . The interruption device 103 is located between the excitation device 102 and the conductor 104 . The excitation device 102 is fixed by limiting steps and pressing plates (not shown) in the cavity. The excitation device 102 can receive an excitation signal from the outside and act to provide driving force for the interruption device 103 . When the excitation device 102 is a gas generating device, the breaking device 103 is in sealing contact with the cavity, and the sealing contact is generally achieved by the interference fit between the breaking device 103 and the cavity. The high pressure gas is generated by the detonation of the gas generating device to drive the displacement of the breaking device 103 . The excitation device 102 may also be an air cylinder, a hydraulic cylinder, an electromagnet drive, etc., all of which can act according to the received external excitation signal.

The breaking device 103 is fixed in the cavity through the limiting mechanism, so as to ensure that the breaking device 103 is fixed at the initial position, and will not cause malfunction due to displacement in the cavity. The limiting mechanism may be small bumps arranged at intervals on the outer circumference of the breaking device 103, and grooves are formed on the inner wall of the corresponding cavity, and the bumps of the breaking device 103 are snapped into the grooves to achieve position limitation. When the breaking device 103 receives the driving force from the excitation device 102, the limiting mechanism can be disconnected under impact, thereby releasing the limiting effect.

At least three disconnected weak points 107 are spaced apart on the conductor 104 located in the housing. As shown in FIG. 1 , the conductors 104 in the casing have a trapezoidal structure, and the conductors 104 at the inner side of the casing are respectively provided with disconnected weak points 107 , which are called the first group of disconnected weak points. The conductors 104 between the weak points are provided with two broken weak points 107 spaced apart, which are called the second group of broken weak points, and the two groups have a total of four broken weak points 107 . The purpose of the break weak point 107 is to reduce the breaking strength of the conductor 104, so that it is easier to break when it is impacted. The disconnected weak point 107 can be the conductor 104 with a reduced thickness or the width of the conductor 104 with a reduced width. For example, a U-shaped slot, a V-shaped slot, a hole, etc. are opened on one or both sides of the conductor 104; it is also possible to reduce the width of the conductor 104. structure, so as to generate stress concentration in the transition area, such as reserving a gap; or use low-strength conductor material 107 to replace the body material of conductor 104 at the weak point 107, such as tin, etc.; or use mechanical compression and/or fixed prefabricated Break etc.

On the end face of the breaking device 103 on one side of the conductor 104, there are spaced impact heads 108 that can break the weak points 107 at the two ends of the conductor 104 in the casing. Between the two impact heads 108, the corresponding conductors Protruding ends are respectively opened at the adjacent positions of the weak point 107 104 . Between the two adjacent protruding ends, a cavity is reserved for the conductor 104 to be completely disconnected at the weak point 107 . After the impact end 108 of the breaking device 103 breaks the first set of breaking weak points on the conductor 104 to form a first set of at least two fractures, the protruding end of the breaking device 103 abuts against the non-contact surface of the breaking conductor portion 200 Breaking the weakness 107 forces the breaking conductor portion 200 to displace within the housing.

At the bottom of the casing, a sharp-edged rib 110 is provided corresponding to the disconnected weak point 107 on the disconnected conductor portion 200 . When the breaking device 103 forces the disconnected part of the conductor 104 to move to the bottom of the housing, the matching rib 110 can disconnect the disconnected weak point 107 on the disconnected conductor part 200 to form a second group of fractures. The fracture includes at least one fracture.

When the conductor 104 is provided with a plurality of broken weak points 107 , a plurality of impact heads 108 may be arranged on the breaking device 103 at intervals, and a convex rib 110 may also be arranged. Taking the conductor 104 with five broken weak points 107 as an example, one broken broken point 107 is set at each end of the conductor 104 in the housing, and three broken broken points 107 are arranged at intervals between the two broken broken weak points 107 . Open weak points 107, wherein, the broken weak points 107 at both ends of the conductor 104 and the broken weak point 107 located in the middle are the first group of broken weak points, located between the weak points at both ends of the conductor 104 and the middle weak point The other two disconnected weak points 107 are the second group of disconnected weak points, that is, the remaining two disconnected weak points 107 except the above-mentioned first group of disconnected weak points are the second group of disconnected weak points. The breaking device 103 is provided with three impact heads 108 at intervals, respectively corresponding to the three broken weak points 107 in the first group of broken weak points, and two raised ribs 110 on the cutting structure are provided, respectively corresponding to the second group of broken weak points. Two of the broken weaknesses 107 correspond. After the breaking device 103 breaks the conductor 104, a first group of breaks and two broken conductor portions 200 separated from the conductor 104 are formed at the conductor 104, and one broken conductor portion 200 is left unbroken on each broken conductor portion 200. The open disconnected weak point 107; as the breaking device 103 moves against the two disconnected conductor parts 200 to the ridge 110 at the bottom of the housing, the raised rib 110 breaks the disconnection on the aforementioned disconnected conductor part 200 The weakness 107 forms a second set of fractures.

It can be seen from the above that the first group of fractures includes at least two fractures, and the second group of fractures includes at least one fracture. The conductors 104 are disconnected successively by grouping disconnection, and multiple groups of multiple fractures that are disconnected at different times are formed on the conductors 104 to improve the breaking capacity and the arc extinguishing capacity.

In order to better improve the breaking capacity and the arc extinguishing capacity, an arc extinguishing medium or an arc extinguishing structure 106 is provided at the cavity between the two adjacent protruding ends of the breaking device 103 . 4 to 6 , the arc extinguishing medium can be gas, liquid, or solid granular arc extinguishing material, and the arc extinguishing structure is an arc extinguishing grid-like structure or a solid non-granular arc extinguishing material. When the arc extinguishing medium is gas, liquid or solid arc extinguishing medium, it needs to be sealed by the sealing plate 109 . After the sharp-edged ridge 110 disconnects the weak point 107 of the conductor, the raised rib 110 can break the sealing plate 109 of the arc-extinguishing medium, so that the arc-extinguishing medium leaks from the break and covers the weak point 107 for extinguishing. arc. An arc extinguishing structure 112 is provided on the inner wall of the casing through which the disconnected conductor portion 200 is displaced between the bottoms of the casings of the conductor 104 , and the arc extinguishing structure 112 is an arc extinguishing grid-like arc extinguishing structure or a solidified non-granular extinguishing structure. Arc media, etc. In this embodiment, they may all be arc chute structures, but should not be regarded as a limitation.

The working principle of the above-mentioned fuse structure: the excitation device 102 acts when receiving an external excitation signal, provides a driving force to the interrupting device 103, drives the interrupting device 103 to impact and displace in the direction of the conductor 104, and the interrupting device 103 first disconnects the device located in the shell. The first group of broken weak points at the inner wall forms a first group of fractures, and the first group of fractures includes at least two fractures. The conductor 104 located in the housing is partially disconnected. At this time, at least one unbroken disconnected weak point 107 remains on the disconnected conductor portion 200 that has been disconnected from the original position, that is, the second group is disconnected. The weak points, the second group of broken weak points in FIG. 1 are two unbroken broken weak points 107 . As the disconnected conductor portion 200 is forced by the breaking device 103 to move downward to the bottom of the housing until the bottom dead center of the housing, the second set of disconnected weak points on the disconnected conductor portion 200 is at the bottom of the housing ridge 110 Under the action of the fracture, the second group of fractures is formed, and the second group of fractures includes at least one fracture. The above working principle realizes the grouping disconnection of multiple fractures on the conductor 104 . When the arc-extinguishing medium is gas, liquid or granular solid, the convex rib 110 will break the sealing plate 109 of the arc-extinguishing medium after breaking the second group of fractures, so that the arc-extinguishing medium pours out at the second group of fractures to participate in the extinguishing arc.

The arc extinguishing principle of the above fuse structure is explained as follows:

First, the arc resistance at the fracture is much greater than the resistance of conductor 104 .

Under a low multiple fault current, the excitation device 102 drives the interruption device 103 to interrupt the first group of fractures of the conductor 104 after being triggered by an external excitation signal, and an arc is generated after the first group of fractures of the conductor 104 is interrupted. Between the fractures of the conductor 104, the total resistance increases compared with that before the first group of fractures is disconnected, the voltage across the conductor 104 remains unchanged, and the fault current decreases; the breaking device 103 continues to move downward and forms a slit with the inner wall of the lower shell Squeeze the arc, the arc is cooled by the arc extinguishing medium in the arc extinguishing chamber inside the lower shell during the movement, the arc resistance increases, the fault current is further reduced to the point where it is difficult to hold the arc, the arc is completely extinguished, and the fault current is cut off; The device 103 continues to move and squeezes the conductors in the middle of the first group of fractures of the conductor 104 with the sharp-edged rib 110 structure of the lower casing. Fracture, the second group of fractures is broken, forming a clean physical fracture, and enhancing the insulation performance after breaking. If the physical fracture is not clean, that is, there is too much conductive material around the fracture or carbonized conductive material after the arc burns the plastic, the fracture will be easily broken down by voltage, forming a path, reducing the insulating ability, and may cause the arc to reignite and break. fail.

Under the high multiple fault current, the excitation device 102 drives the interruption device 103 to interrupt the first group of fractures of the conductor 104 after being triggered by the external excitation signal, and the first group of fractures of the conductor 104 is disconnected to generate an arc. At this time, the arc is connected in series in Between the fractures of the conductor 104, the total resistance increases compared with that before the first group of fractures is disconnected, the voltage across the conductor 104 remains unchanged, and the fault current decreases; the breaking device 103 continues to move downward and forms a slit with the inner wall of the lower shell The arc is squeezed, and the arc is cooled by the arc extinguishing medium in the arc extinguishing chamber inside the lower shell during the movement, the arc resistance increases, and the fault current is further reduced. Hold the arc; the breaking device 103 continues to move and squeezes the conductor in the middle of the first group of fractures of the conductor 104 with the sharp-edged rib 110 structure of the lower shell, and the conductor in the middle of the first group of fractures of the conductor 104 is broken at the weak point to form The second set of fractures. A small arc is generated at the second group of fractures. As the breaking device 103 cooperates with the lower casing to squeeze the arc between the second group of fractures, the arc is cooled by the arc-extinguishing medium in the groove at the lower end of the breaking device 103. The resistance continues to increase, the fault current is reduced to the point where it is difficult to hold the arc, the arc is completely extinguished, and the fault current is cut off.

In order to further improve the arc extinguishing effect, an auxiliary arc extinguishing melt 111 is also provided on the conductor 104 .

Arc-extinguishing melt arrangement scheme A, as shown in A in FIG. 7 , conductors 104 on both sides of all disconnected weak points 107 of conductor 104 are respectively connected to one end of an arc-extinguishing melt 111 , and the other end of the arc-extinguishing melt is connected. One end is arranged on the bottom of the casing outside all the ridges 110. Before the breaking conductor part 200 moves to the sharp-edged ridges 110 at the bottom of the casing, both ends of the breaking conductor part 200 are in contact with the arc-extinguishing melt. Connection; as the breaking device 103 continues to move, the rib 110 breaks the breaking weakness 107 on the breaking conductor portion 200 to form a second set of fractures.

The arc-extinguishing melt arrangement B, as shown in B in FIG. 7 , is provided with arc-extinguishing melts 111 on both sides of the ridges 110 at the bottom of the casing, and both ends of the arc-extinguishing melt are slightly higher than the ridges 110 . With the formation of the first group of fractures, when the disconnected conductor portion 200 moves to the bottom of the casing, its two ends first contact both ends of the melt; as the disconnected conductor portion 200 continues to move, it is disconnected by the raised rib 110, and the disconnection The weakness 107 forms a second set of fractures.

Arrangement scheme C of the arc-extinguishing melt, as shown in C in FIG. After the first set of fractures are formed, current flows through the melt to fuse and extinguish the arc, and then the conductor portion 200 is disconnected to form the second set of fractures again. In this solution, the fractures include two groups of fractures of the conductor 104 and fractures of the arc-extinguishing melt.

Arrangement scheme D and E of the arc-extinguishing melt, as shown in D and E in FIG. 7 , connect one end of the arc-extinguishing melt to the conductor 104 on the outer side of all the disconnected weak points 107 of the conductor 104, and the other end of the arc-extinguishing melt. One end is arranged on the bottom of the casing outside the convex rib 110. Before the disconnecting conductor part 200 moves to the sharp-edged convex rib 110 at the bottom of the casing, one end of the disconnecting conductor part 200 is connected with the arc-extinguishing melt; As the breaking device 103 continues to move, the cooperating rib 110 breaks the broken weak point 107 on the broken conductor part 200 to form a second group of fractures.

The melts in the above-mentioned schemes A, D, and E can be located on one side or both sides of the rib 110; the melts in schemes B and C can be arranged through the rib 110, or can be placed in the shell below the rib 110. in the body wall. In a word, the setting of the melt does not affect the breaking of the weak point 107 of the conductor part 200 by the rib 110 .

FIG. 8 is a schematic diagram of the structure when the arc-extinguishing melt is in contact with the disconnected conductor portion 200 . In the figure, picture A is a schematic diagram of the structure when scheme A is working; picture B is a schematic diagram of the structure when scheme B is working. Since the principles of schemes A, D, and E are the same, only scheme A is taken as an example. Option C The melt is not in contact with the disconnected conductor portion 200, and no structural diagram is provided.

9 is a circuit schematic diagram, A is the circuit schematic diagram of the arc-extinguishing melt scheme A; B is the circuit schematic diagram of the arc-extinguishing melt scheme B. Since Schemes D and E are connected in parallel with Scheme A in a similar manner and in the same principle, scheme A is used as an example in the circuit schematic diagram. Option C is to directly connect the melt on the conductor 104 in parallel. Because of its simplicity, the circuit schematic diagram will not be used for description.

Before the conductor 104 is disconnected, the resistance of the melt (RF1, RF2, RF3) is much greater than the resistance of the conductor 104. At this time, the total resistance of the excitation fuse is approximately equal to the resistance of the conductor 104; after the conductor 104 is disconnected, the arc at the fracture The resistance is much greater than that of the melt (RF1, RF2, RF3).

Option A works as follows:

When the disconnected weak point 107 between ac and bd on the conductor 104 is broken to form the first group of fractures, the middle conductor of the conductor 104 will interact with the melt F1 and the melt during the downward movement of the conductor 104. The body F2 is connected, the fault current will flow through the melt F1 and the melt F2, the fracture resistance between the ac and bd is much larger than that of the melt, so almost no arc is generated, and the melt F1 and the melt F2 are connected in series at this time. In the circuit, the total resistance increases compared to that before the first group of fractures is disconnected, the voltage across the conductor 104 remains unchanged, and the fault current decreases.

At this time, it is roughly divided into three situations according to the size of the fault current: under the low multiple fault current, the fault current flowing through the melt F1 and the melt F2 is not enough to fuse the melt, and the weak point 107 of the disconnection between the ce The weak point 107 between the disconnection and de is interrupted to form a second group of fractures, the arc generated at the second group of fractures is squeezed, the arc resistance increases, the fault current is reduced to the point where it is difficult to hold the arc, the arc is completely extinguished, and the fault occurs. The current is cut off; under the medium multiple fault current, the fault current flowing through the melt F1 and the melt F2 causes the narrow diameter of the melt F1 and the melt F2 to start to melt. The weak point 107 between 107 and de is broken to form a second group of fractures, the arc generated at the second group of fractures is squeezed, and the melt and the second group of fractures work together to extinguish the arc and break the fault current; high multiples Under the fault current, the fault current flowing through the melt F1 and the melt F2 makes the melt F1 and the melt F2 fuse rapidly, and the fault current is cut off. At this time, the second group of fractures is interrupted, which enhances the insulation performance after breaking.

Option B works as follows:

When the disconnection weak point 107 between ac and bd on the conductor 104 is broken to form the first group of fractures, an arc is generated at the first group of fractures, and the conductor moves downward in the middle of the conductor 104. During the process, it is connected to the melt F3. At this time, the arc of the first group of fractures is connected in series in the circuit, and the fault current flows through the arc of the first group of fractures and the conductor between the cd on the conductor 104. The total resistance is higher than that of the first group of fractures. Increases before interruption, the voltage across conductor 104 does not change, and the fault current decreases.

At this time, it is roughly divided into three situations according to the magnitude of the fault current: under the low multiple fault current, the arc generated by the first group of fractures is stretched and squeezed, the arc resistance increases, the fault current is further reduced to the point where it is difficult to hold the arc, and the arc Completely extinguished, the fault current is cut off, and the piston continues to move to interrupt the second group of fractures. In this case, the first group of fractures is sufficient to interrupt the low multiple fault current; under the medium multiple fault current, the arc generated by the first group of fractures is elongated, Squeeze but still hold the arc, the disconnection weak point 107 between ce and de is interrupted to form the second group of fractures, the fault current flows through the melt F3, and the second group of fractures Almost no arc is generated. At this time, the melt F3 is connected in series in the circuit, and the total resistance is increased compared with that before the second group of fractures is interrupted. The fault current is further reduced to the point where it is difficult to hold the arc. The arc is completely extinguished and the fault current is cut off; Under the multiple fault current, the arc generated by the first group of fractures is elongated and squeezed but can still hold the arc, and the broken weak point 107 between ce and de is interrupted to form the second group. After the fracture, the fault current flows through the melt F3, almost no arc is generated at the second group of fractures, and the fault current is cut off with the melting of the melt F3.

It can be seen from the above that adding a parallel arc extinguishing melt can improve the breaking capacity and arc extinguishing capacity of the fuse.

Industrial Applicability:

In the technical solution proposed in the present disclosure, the excitation fuses are grouped on the conductor 104 successively to form multiple groups of multiple fractures in sequence, and the multiple fractures formed by the multiple groups of time delays realize the reliability of arc extinguishing and disconnection, and improve the reliability of arc extinguishing and disconnection. Breaking capacity and arc extinguishing capacity.

Claims

A multi-break excitation fuse disconnected in groups is characterized in that it comprises a casing, a cavity is opened in the casing, a conductor is passed through the casing, and the cavity is divided into two parts , an excitation device and an interruption device are sequentially arranged in the cavity on one side of the conductor, and the interruption device is driven by the excitation device to interrupt the conductor; the cavity on the other side of the conductor is arranged There is at least one cutting structure that can cut off the conductor; two groups of weak points for breaking are arranged at intervals along the length direction of the conductor located in the casing; At least one disconnected conductor part that can be disengaged from the original position is formed after the conductor is disconnected at this point to form a first group of fractures, and the second group of disconnected weak points is arranged on the disconnected conductor part; when the disconnected conductor part is When displaced to the cut-off structure, the cut-off structure cuts off the cut-off conductor portion from the second set of cut-off weak points to form a second set of fractures, the first set of fractures includes at least two fractures, The second set of fractures includes at least one fracture.
The multi-break excitation fuse for group disconnection according to claim 1, characterized in that, on the end face of the breaking device on one side of the conductor, corresponding to the second group of disconnected weak points of the conductor, A cavity is respectively opened, and an arc extinguishing medium or an arc extinguishing structure is arranged in the cavity.
The multi-break energizing fuse disconnected in groups according to claim 2, wherein the arc-extinguishing medium is gas, liquid or solid particulate matter, and the arc-extinguishing medium is sealed in the cavity through a sealing plate inside; after the cutting structure breaks the second group of broken weak points on the broken conductor portion, the cutting structure can break the sealing plate.
The multi-break excitation fuse for group disconnection according to claim 2 or 3, wherein the arc extinguishing structure is an arc extinguishing grid.
The multi-break excitation fuse for group disconnection according to any one of claims 1 to 4, characterized in that, on the inner wall of the casing where the disconnected conductor portion is displaced to the cut-off structure, there is provided with an extinguishing An arc chamber, wherein a solidified arc extinguishing medium or an arc extinguishing grid is arranged in the arc extinguishing chamber.
The multi-break energizing fuse for group disconnection according to any one of claims 1 to 5, wherein the cutting structure is a rib.
The multi-break energizing fuse for group disconnection according to any one of claims 1 to 6, characterized in that, grooves and holes for reducing conductor strength are used at the weak point of disconnection, and conductor width is reduced for stress concentration. , one or more materials with lower strength than the conductor material are combined.
The multi-break energizing fuse for group disconnection according to any one of claims 1 to 7, characterized in that at least one fuse is connected to the conductor in the housing.
The multi-break energizing fuse disconnected in groups according to claim 8, wherein both ends of the melt are connected to conductors in parallel, and all disconnected weak points on the conductors are located at both ends of the melt between.
The multi-break energizing fuse for group disconnection according to claim 8 or 9, characterized in that, in the housing, the melt is connected to the outside of one or two disconnected weak points located at the outermost side one end of the melt, the other end of the melt is located outside the cutting structure; when the disconnected conductor part is displaced to a position close to the cutting structure and is not disconnected, the disconnected conductor part can be connected with the melt An end located outside the cut-off structure is connected.
The multi-break energizing fuse for group disconnection according to any one of claims 1 to 10, wherein a melt is provided at the disconnecting structure; when the disconnecting conductor portion is displaced to be close to the disconnecting When the structure is not disconnected, the two ends of the disconnected conductor portion at the disconnected weak point can be connected to both ends of the melt.
The group-disconnected multi-break energizing fuse according to any one of claims 1 to 11, wherein the energizing device comprises a gas generating device.
According to the multi-broken excitation fuse for group breaking according to any one of claims 1 to 12, a plurality of impact heads are arranged on the breaking device at intervals.
The multi-break energizing fuse disconnected in groups according to claim 2, wherein the arc-extinguishing structure comprises a solid non-granular arc-extinguishing substance.
A power distribution unit, characterized in that the application comprises at least one excitation fuse as claimed in any one of the preceding claims 1 to 14 .
An energy storage device, characterized in that the application comprises at least one excitation fuse according to any one of the preceding claims 1 to 14 .
A new energy vehicle, characterized in that the application includes at least one excitation fuse according to any one of claims 1 to 14.