CN217788321U

CN217788321U - Self-excitation protection device

Info

Publication number: CN217788321U
Application number: CN202221571725.2U
Authority: CN
Inventors: 石晓光; 王立强; 姜依玲
Original assignee: Xian Zhongrong Electric Co Ltd
Current assignee: Xian Zhongrong Electric Co Ltd
Priority date: 2022-06-22
Filing date: 2022-06-22
Publication date: 2022-11-11
Anticipated expiration: 2032-06-22

Abstract

The invention belongs to the field of circuit protection, and discloses a self-excitation protection device, which comprises a first conductor, a second conductor, a driving melt and at least one piston, wherein the first conductor and the second conductor are arranged in an insulated manner; driving the melt in series between a first conductor and a second conductor; when the driving melt is fused, the generated arc energy or elastic force can drive the piston to displace to disconnect the first conductor and/or the second conductor. The self-excitation protection device does not need a special excitation source, an excitation circuit for sending an excitation signal and a power supply, improves the breaking capacity and reduces the production cost.

Description

Self-excitation protection device

Technical Field

The invention relates to the field of power control and electric automobiles, in particular to a protection device for circuit protection, which cuts off the circuit to carry out current breaking through self-generated driving force.

Background

An excitation protection device that quickly cuts off the opening already exists and gradually expands the range of applications. The traditional fuse is a protection device which utilizes the current heat accumulation effect to lead a current sensing point, namely a narrow neck, arranged on a melt to melt and break and extinguish electric arcs in a certain time. The excitation fuse is a rapid protection device which utilizes an electronic gas generating device to push an insulator to cut off a conductor to form a physical fracture in a short time.

The traditional fuse has the advantages of being mature and stable, high in upper limit of breaking, strong in arc extinguishing capability and the defects of: the current impact resistance is poor; the heating value is large; the circuit can be disconnected for a long time under low-multiple fault current, and quick protection cannot be realized; the fuse can not achieve complete physical isolation after fusing, which is mainly characterized in that the insulation resistance value after fusing is small, and the value range is 0.1 MOmega-50 MOmega; the volume and weight are large. The excitation protection device has the advantages that the rapid protection is realized by rapidly cutting off the opening, the current impact resistance is good, the heating value is small, the complete physical isolation can be realized after the disconnection, and the numerical range of the insulation resistance after the disconnection is more than 5M omega.

However, excitation protection devices currently have some disadvantages:

1. the gunpowder is needed, the service life of the gunpowder is prolonged, the gunpowder can lose efficacy under the condition of long-time non-use, and potential safety hazards are caused.

2. An additional electronic ignition device is required.

Disclosure of Invention

The invention aims to provide a self-excitation protection device, which can break the self-excitation protection device through the movement of a piston by using arc energy generated by the protection device under the condition of unused gunpowder and an electronic ignition device, thereby reducing potential safety hazards; or the elastic force generated after the protection device is fused is used as the driving force to drive the piston to move to break the protection device.

Aiming at the aim, the technical scheme provided by the invention is a self-excitation protection device, which comprises a first conductor, a second conductor, a driving melt and at least one piston, wherein the first conductor and the second conductor are arranged in an insulating way; driving the melt in series between a first conductor and a second conductor; when the driving melt melts, the generated arc energy or elastic force can drive the piston to displace to disconnect the first conductor and/or the second conductor.

Preferably, the piston is located on one side of the drive melt or is separated from the drive melt by a cavity structure in which the drive melt is located.

Preferably, when there are two pistons, the two pistons respectively correspond to the first conductor and the second conductor; when the driving melt is fused, the generated arc energy can respectively drive the two pistons to displace to disconnect the first conductor and the second conductor simultaneously or sequentially.

Preferably, a second melt is connected in parallel to the driving melt, and when the driving melt is fused, the second melt is fused, and the energy of the arc energy generated by the fusion of the second melt can drive the piston to displace to disconnect the first conductor and/or the second conductor.

Preferably, the driving melt is arranged in a flexible film ball in a penetrating mode, when the driving melt is fused, the generated arc energy can drive the flexible film ball to expand to drive the piston to displace and disconnect the first conductor and/or the second conductor.

Preferably, a hydraulic device is arranged between the driving melt and the piston, when the driving melt is fused, the generated arc energy can drive the hydraulic device to act, and the piston is driven to displace by the hydraulic device to disconnect the first conductor and/or the second conductor.

Preferably, a third melt is connected in parallel to the first conductor and/or the second conductor respectively, and when the driving melt melts, the generated arc energy can drive the piston to displace to break the first conductor and/or the second conductor and then break the third melt.

Preferably, the driving melt binds the elastic device to be in a compressed state, and when the driving melt is fused, the elastic force of the elastic device drives the piston to displace to disconnect the first conductor and/or the second conductor.

Preferably, the cavity where the first conductor and the second conductor are located is filled with arc extinguishing media, the cavity where the first conductor and the second conductor are located is provided with an opening through which the arc extinguishing media flow out of the cavity, and the opening is detachably plugged by a plug.

Preferably, the piston closes a cavity in which the drive melt is located, and an arc-extinguishing medium is filled in the cavity.

The invention also provides a self-excitation protection device, which comprises a first conductor and a second conductor which are insulated from each other, wherein a driving melt and a piston are connected in series between the first conductor and the second conductor; at least one first melt is connected in parallel with the driving melt; when the driving melt fuses, the piston can be driven to displace to disconnect the first melt.

The self-excitation protection device provided by the invention has the advantages that the electric arc energy generated by driving the fused melt to be fused per se is used for quickly breaking the conductor or connecting the first melt in parallel, an electronic ignition device and an excitation circuit for sending an excitation signal are saved, the breaking capacity is improved, the production cost is reduced, and the safety and reliability are improved. Meanwhile, the arc energy generated by the fuse body is utilized to directly drive the breaking conductor or the first fuse body connected in parallel, so that in a relatively high-voltage application environment, the length of the driving fuse body can be shorter, the power consumption of the fuse can be smaller, and the energy-saving effect is remarkable. Meanwhile, the volume of the fuse can be further reduced.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment.

FIG. 2 is a schematic cross-sectional view of the embodiment.

FIG. 3 is a schematic cross-sectional structure of the second embodiment.

FIG. 4 is a schematic structural diagram of the third embodiment.

FIG. 5 is a schematic cross-sectional view of the embodiment.

FIG. 6 is a schematic cross-sectional structure of the fifth embodiment.

Fig. 7 is a schematic view of the spring and drive melt configuration of fig. 6.

FIG. 8 is a schematic diagram of a sixth embodiment.

FIG. 9 is a schematic structural view of the seventh embodiment.

Fig. 10 is a schematic structural diagram of an eighth embodiment.

Fig. 11 is a schematic sectional view of the embodiment.

Figure 12 shows a schematic cross-sectional structure of the ninth embodiment.

Detailed Description

The structural orientation terms such as up, down, left, right, front, rear, top, bottom, etc. referred to in the specification do not limit the structural position, but merely facilitate understanding.

Example one

The self-energizing protection device of the present invention mainly comprises a housing 10, a first conductor 20, a second conductor 30, a drive melt 40, a first piston 50, and referring to fig. 1 to 2:

the housing 10 is made of an insulating material, and includes a first housing 100 and a second housing 101, which are butted to form a housing. A groove through which the first and

second conductors

20 and 30 pass is provided at the mating surface of the first and second housings. A first cavity 102 and a second cavity 103 are arranged in the housing in a sealed manner, and the first cavity and the second cavity are completely isolated.

The first conductor 20 is in an L-shaped structure, one part of which is located in a groove at the butt joint face of the first housing and the second housing, the other part of which passes through the second cavity 103 and then extends out of the housing, and one end located outside the housing is a connection end.

One end of the second conductor 30 is inserted into a groove formed at the butt joint surface of the first housing and the second housing, and the other end is located outside the housing as a connection end. The second conductor 20 is spaced apart from the first conductor 30 by an insulation distance.

The drive melt 40 is disposed in the first cavity 102 and has two ends that pass through the inner wall of the housing and are electrically connected to the first conductor and the second conductor, respectively, in series relationship therewith. The connection form of the driving melt and the first conductor and the second conductor can adopt bolt compression joint, conductive elastic sheet connection, welding and the like.

The first piston 50, which is made of an insulating material, is located in the first cavity 102 on the side where the melt 40 is driven. The first piston 50 is a T-shaped structure with a large diameter end on the side of the drive melt 40 dividing the first cavity into two cavities. The cavity in which the drive melt 40 is located is the first arc-quenching chamber 105. The first quenching chamber 105 is filled with a quenching medium.

The side face, in contact with the housing, of the first piston 50 is provided with a limiting bump 501 and a slider 502, the contact face, corresponding to the limiting bump 501, of the housing is provided with a limiting groove, the limiting groove is located at the butt joint face of the first housing and the second housing, and the limiting bump 501 is clamped in the limiting groove to limit the initial position of the first piston 50. A strip-shaped sliding groove 104 is formed in the position, corresponding to the sliding block, on the inner wall of the shell, and the sliding groove 104 is located on the butt joint face of the first shell and the second shell. The sliding block 502 of the first piston 50 is engaged with the sliding slot 104, so that the piston can linearly displace along the sliding slot 104. The impact end, i.e. the smaller diameter end, of the first piston 50 extends through the sealed partition between the first and second cavities into the second cavity. The contact surface between the piston impact end and the partition plate is in sealing contact, and sealing is realized by adopting interference fit or arranging an elastic sealing element on the contact surface between the piston impact end and the partition plate, so that electric arcs are prevented from entering the second cavity.

The working principle is as follows:

when the fuse is connected in series into the circuit, current normally flows through the first conductor 20, the second conductor 30, and the drive fuse element 40. When fault current occurs, the fuse element 40 is driven to fuse to generate electric arc, and when the generated electric arc is extinguished for the first time, the circuit is disconnected by driving the fuse element to fuse;

when the driving melt 40 is fused to form an arc, arc energy is accumulated in the first arc extinguishing chamber 105 to form a driving force for driving the first piston 50 to move, the first piston 50 is driven to break the limiting bump 501, the limiting bump moves linearly along the sliding groove 104, the impact end of the first piston 50 breaks the first conductor 20 in the second cavity to form a fracture, a circuit is completely broken, and breaking is achieved.

In this embodiment, whether the first piston seals the first arc-extinguishing chamber 105 in which the driving melt 40 is located is treated as the case may be, since the first cavity and the second cavity are completely insulated from each other. When the first arc extinguishing chamber 105 in which the driving melt 40 is located is not filled with arc extinguishing medium, the arrangement of the piston only needs to meet the requirement that the driving melt 40 is fused, and the generated arc energy can drive the first piston 50 to overcome the displacement of the limiting structure and break the first conductor.

When the first arc-extinguishing chamber 105, in which the melt 40 is driven, is filled with an arc-extinguishing medium, the first piston 50 must be sealed from the housing to prevent leakage of the arc-extinguishing medium from impeding the movement of the piston. The sealing between the first piston 50 and the housing is achieved by interference fit or by providing a seal between the contacting surfaces.

Example two

The improvement is carried out on the basis of the first embodiment. Referring to fig. 3, a third cavity 109 is added to one side of the first cavity 102, and the third cavity 109 is insulated from the second cavity 102 by a partition. The second conductor 30 is of the same construction as the first conductor 20 and is L-shaped with one end disposed in a recess in the wall of the housing and one end extending outside the housing through the third cavity 109. A drive melt 40 is located in the first cavity 102 and is connected in series with the first conductor 20 and the second conductor 30. A first piston 50 and a second piston 50a are disposed on either side of the drive melt 40. The second piston 50a is identical in structure to the first piston 50. The impact end of the second piston 50a passes through the first cavity and the partition of the third cavity into the third cavity 109. The second piston is in sealing contact with the contact surface of the partition plate. Sealing is achieved by interference fit or by arranging an elastic sealing element on the contact surface of the impact end of the piston and the partition plate, so that electric arcs at the position of the driving melt are prevented from entering the third cavity 109.

The first cavity 102, in which the drive melt is located, is divided into three chambers by a first piston and a second piston, and a first arc-extinguishing chamber 105, in which the drive melt 40 is located, is filled with an arc-extinguishing medium between the first piston and the second piston.

The distance between the impact ends of the first piston and the second piston and the first conductor and the distance between the impact ends of the first piston and the second conductor can be the same or different, namely, the first piston and the second piston can cut off the first conductor and the second conductor synchronously or cut off the first conductor and the second conductor sequentially.

The working principle is as follows:

when the fuse is connected in series into the circuit, current normally flows through the first conductor 20, the second conductor 30, and the drive fuse element 40. When fault current occurs, the fuse melt 40 is driven to fuse to generate electric arc, and when the generated electric arc is extinguished in the first time, the circuit is disconnected by driving the fuse melt 40 to fuse;

when the driving melt 40 melts to form an arc, arc energy is accumulated in the first arc extinguishing chamber 105 to form a driving force for driving the first piston 50 and the second piston 50a to displace, the first piston 50 and the second piston 50a are driven to break the position limitation of the limit bump and the limit groove respectively, the first piston 50 and the second piston 50a displace to break the first conductor 20 and the second conductor 30 in the second cavity and the third cavity respectively to form a fracture, and a circuit is completely broken, so that the breaking is realized.

When the cavity where the driving melt is located is filled with arc extinguishing medium, the arc extinguishing medium cannot leak from the first piston and the second piston to influence the movement of the first piston and the second piston when the arc drives the first piston and the second piston to move due to the sealing between the contact surfaces of the first piston, the second piston and the shell.

EXAMPLE III

In the first embodiment, the housing may also be a concave structure as shown in fig. 4, and an external groove structure 106 is formed outside the housing. The first conductor 20 and the second conductor 30 are both in a straight line structure, the driving melt 40 is positioned in a first cavity 102 in the shell on one side of the groove outside the shell, and the first conductor 20 passes through a second cavity 103 on the other side of the groove structure 106 outside the shell, then passes through the groove structure 106 outside the shell and then is connected with the driving melt 40 in the first cavity 102; the first piston 50 is located in the first cavity 102 above the second cavity 103.

In the third embodiment, the first cavity 102 in which the driving melt 40 is located is deformed and elongated, so that the driving melt 40 and the first piston 50 are respectively disposed on two sides of the outer groove structure 106, and arc isolation is performed through a spatial structure, so that when the driving melt 40 melts, the first piston 50 is prevented from being ablated by an arc.

When the cavity where the driving melt is located is filled with arc extinguishing medium, the arc extinguishing medium cannot leak from the first piston to influence the movement of the first piston when the arc drives the first piston to move due to the sealing between the contact surfaces of the first piston and the shell.

The working principle is the same as that of the first embodiment.

Example four

In addition to the second embodiment, the configuration of the cavity in the housing is modified such that the drive melt 40 and the first and

second pistons

50 and 50a are separated by the first cavity configuration in the housing. Referring to fig. 5, one side of the housing is in a bow-shaped configuration, and two groove structures 106 are formed outside the housing. The interior of the housing is divided into three cavities, a first cavity 102, a second cavity 103 and a third cavity 109, by partitions 110. The second cavity 103 and the third cavity 109 are located outside the groove structure 106, respectively. The drive melt 40 is located in the first cavity 102 in the housing between the two groove structures 106. The first conductor 20 penetrates through the second cavity 103 and the groove structure 106 adjacent to the second cavity and then is connected with one end of the driving melt 40 in series; a second conductor 30 is connected in series with the other end of the drive melt 40 after passing through a third hollow 109 and the groove structure 106 immediately adjacent thereto. In fig. 5, the first conductor and the second conductor are both in a line-shaped structure. The first conductor and the second conductor can change the shape and structure according to actual needs. The first and

second pistons

50 and 50a, respectively, are located in the housing outside of the groove structure 106. The first piston 50 and the third piston 50a have the same structure as the first piston 50 of the first embodiment, and are both T-shaped, and the impact ends are respectively located in the second cavity and the third cavity through the partition 110. The first piston 50 and the second piston 50a are each isolated from the drive melt 40 by a first cavity structure within the housing. The first piston 50 and the second piston 50a are sealed with the contact surface of the shell or gaps are reserved according to the arc state after the driving melt 40 is melted, and the arc energy can drive the first piston and the second piston to overcome the displacement of the limiting structure to cut off the first conductor and the second conductor.

In the first cavity 102, a first arc-extinguishing chamber 105 is formed between the first piston and the second piston, the driving melt is located in the first arc-extinguishing chamber 105, and the first arc-extinguishing chamber 105 is filled with an arc-extinguishing medium.

The working principle is as follows:

under normal working state, current flows through the first conductor, the driving melt and the second conductor.

When fault current occurs, the melt 40 is driven to fuse, and when electric arc is instantly extinguished, the melt 40 is driven to fuse to disconnect the circuit to carry out circuit protection;

when the driving melt is fused, an arc is generated at the fused position, and the generated arc energy is relatively large, the arc energy drives the first piston and the second piston to overcome the limiting structure, the first conductor and the second conductor are cut off along the sliding groove in a displacement mode, and a circuit is disconnected.

Because the driving melt is separated from the first piston and the second piston through the first cavity structure of the shell, the arc generated by fusing the driving melt cannot cause ablation on the first piston and the second piston.

EXAMPLE five

Changes may be made in accordance with embodiment one. Referring to fig. 6 and 7, a spring 111 is disposed at the driving melt 40, one end of the spring is fixed on the housing, and the other end is restrained by the driving melt 40, so that the spring 111 is in a compressed state. For better binding of the springs, a drive plate 112 may be fixedly attached to the free ends of the springs, with drive melt 40 being inserted into drive plate 112 to bind the springs.

When the driving melt melts, the spring 111 loses the binding force, and under the action of the elastic force of the spring, the spring drives the driving plate to drive the first piston 50 to overcome the limiting structure to act, so that the first conductor is cut off.

If the cavity in which the melt is driven is filled with an arc-extinguishing medium, it is necessary to ensure that the free end of the spring is in contact with the end face of the first piston, for example, the drive plate is in contact with the end face of the first piston, ensuring that the spring is not blocked in its elongation.

Example six

Changes may be made in the embodiment one. Referring to fig. 8, a hollow flexible membrane sphere 401 is disposed within the first cavity 102, and the drive melt 40 is disposed through the flexible membrane sphere 401. The flexible membrane ball 401 is located on one side of the first piston 50. The flexible membrane ball is made of elastic materials.

The working principle is as follows:

When the fault current occurs, the fuse element 40 is driven to be fused, the electric arc is instantly extinguished, and the circuit is disconnected by driving the fuse element 40 to be fused;

when the driving melt 40 is fused to generate arc holding, the generated arc energy drives the flexible die ball to expand rapidly, the expanded flexible die ball is contacted with the end face of the first piston 50 to provide driving force for the first piston, and the first piston 50 is driven to overcome the displacement of the limiting structure to cut off the first conductor 20 to break a circuit.

EXAMPLE seven

The method is changed on the basis of the fourth embodiment. Referring to fig. 9, a hydraulic drive 114 is added to the first cavity between the first piston 50 and the second piston 50a. The hydraulic device 114 comprises a tubular container, wherein two ends of the tubular melt are in an open structure and are respectively positioned at the end surfaces of the first piston and the second piston, and the opening is closed by the first piston and the second piston. The first piston and the second piston are respectively filled with insulating liquid columns 115 at the closed two ends, and the insulating liquid columns 115 can be displaced under the driving of external force.

The drive melt 40 is inserted into a container of a hydraulic device 114 with the drive melt 40 located between insulating liquid columns 115.

The working principle is as follows:

When the fault current occurs, the melt 40 is driven to fuse, the electric arc is instantly extinguished, and the circuit is disconnected by driving the melt 40 to fuse;

when the driving fuse element 40 melts to generate arc holding, the generated arc energy drives the insulating liquid column 115 to displace towards the first piston and the second piston end, air between the first piston and the second piston is sealed through the compression of the insulating liquid column, and the limiting structures of the first piston and the second piston are overcome along with the increase of air pressure, so that the first piston and the second piston are driven to displace to cut off the circuit of the first conductor 20 and the second conductor 30.

The insulating liquid column and air between the first piston and the second piston can be replaced by insulating liquid, and when the insulating liquid column is driven by telephone energy, the first piston and the second piston are driven by the driving insulating liquid to overcome the displacement of the limiting structure and cut off the first conductor and the second conductor.

Example eight

On the basis of the first embodiment, referring to fig. 10 and 11, the housing is in a convex structure, the first conductor 20 and the second conductor 30 are both L-shaped and are oppositely arranged on two sides of the L-shape of the housing, one part of the first conductor is located in a groove at the butt joint face of the first housing and the second housing, the other part of the first conductor passes through the outer wall of the housing, and one end located outside the housing is a connecting end.

At least one first melt 60, in this embodiment two first melts 60, are disposed in parallel and spaced apart in the second cavity. The first melt 60 is in parallel relationship with the drive melt 40. The resistance of the first fuse element 60 is much greater than the resistance of the drive fuse element 40, and when the fuse element is connected in series in the circuit, current flows through the first conductor, the drive fuse element, and the second conductor under normal conditions, with only a small portion of the current flowing through the first fuse element 60. An arc extinguishing medium, such as quartz sand, is filled in the second cavity to form a second arc extinguishing chamber. The small diameter end 504 of the first piston is of a sheet-like structure, and the end face of the impact end is of a knife-edge structure, so that the impact end of the piston can conveniently displace in the second cavity, and the displacement obstruction is reduced.

A limiting sliding groove is formed in the wall of the housing of the second cavity, and two sides of the small-diameter end of the first piston are clamped in the sliding groove, so that the impact end of the piston does not shake when moving in the second cavity.

A fourth cavity 107 is arranged below the second cavity 103 and adjacent to the second cavity, and a communication channel 108 is arranged on the partition plate connecting the second cavity and the fourth cavity, wherein the communication channel 108 is sealed by a sealing element, such as a sealing film, in the state that the piston is not operated. The strength of the seal is such that when the piston impact end enters the second cavity to cut off the first melt, the impact force imparted by the piston impact end drives the arc quenching medium to break open the seal to open the communication channel 108, allowing the arc quenching medium to enter the fourth cavity.

When the driving melt is fused, most of current is reversed to flow through the first melt, electric arcs generated at the fracture formed by fusing of the driving melt drive the first piston 50 to linearly displace along the sliding chute, and the impact end of the first piston enters the second cavity to sequentially cut off the first melt 60 to form the fracture, so that circuit breaking is realized. In the present embodiment, three fractures are formed in the excitation fuse in total, and a plurality of fractures can improve the breaking capacity and the arc extinguishing capacity.

Example nine

On the basis of the principle of example 2, referring to fig. 12, a second melt 70 is connected in parallel on the drive melt 40, and the second melt 70 is a fuse wire. The resistance of the second melt 70 is much greater than the resistance of the drive melt 40. The second melt 70 is arranged in a closed space and sealed by the first piston 50, and the first piston 50 is provided with a limiting structure at the initial position. A third fuse element 80 is connected in parallel to the first conductor 20, the resistance of the third fuse element 80 also being much greater than the resistance of the first conductor. The second melt 70 and the first piston 50 are isolated from the drive melt 40, respectively. Under normal conditions, current flows through the first conductor, the drive melt, the second conductor, and only a small portion of the current flows through the second melt and the third melt.

Both the drive melt 40 and the second melt 70 may be disposed in an arc-extinguishing chamber filled with an arc-extinguishing medium.

When the driving melt 40 is fused, most of the current flowing through the driving melt 40 flows through the second melt 70, the second melt 70 is fused along with the sudden increase of the current on the second melt 70, the arc energy generated by the fusion of the second melt 70 drives the first piston 50 to overcome the limit structure to move, and after the first conductor is cut off, the first piston can cut off the second melt after the first conductor is cut off.

The working principle is as follows:

under normal conditions, current flows through the first conductor, the drive melt, the second conductor, and only a small portion of the current flows through the second melt and the third melt.

When a fault current occurs, the fuse element 40 is driven to fuse, most of the current flows through the second fuse element 70, the second fuse element fuses, and the generated arc energy drives the first piston 50 to act to cut off the first conductor 20, and then the third fuse element 80 is cut off.

In the above embodiments, the second cavity or the third cavity in which the first conductor and the second conductor are located may be filled with an arc-extinguishing medium. When the arc-extinguishing medium is filled, openings for the arc-extinguishing medium to flow out must be provided in the second cavity and the third cavity. In a normal state, the opening is blocked with a plug. When the piston enters the second cavity or the third cavity to cut off the first conductor or the second conductor, under the driving force of the piston, the arc extinguishing medium presses the plug to be separated from the opening, so that the arc extinguishing medium flows out from the opening, and a displacement space is provided for the first conductor and the second conductor after being disconnected.

Claims

1. A self-excitation protection device is characterized by comprising a first conductor, a second conductor, a driving melt and at least one piston, wherein the first conductor and the second conductor are arranged in an insulated mode; driving the melt in series between a first conductor and a second conductor; when the driving melt melts, the generated arc energy or elastic force can drive the piston to displace to disconnect the first conductor and/or the second conductor.

2. The self-energizing protection device of claim 1, wherein said piston is located on a side of said drive melt or is separated from said drive melt by a cavity structure in which said drive melt is located.

3. The self-energizing protection device according to claim 2, wherein when there are two pistons, the two pistons correspond to the first conductor and the second conductor, respectively; when the driving melt is fused, the generated arc energy can respectively drive the two pistons to displace and simultaneously or sequentially disconnect the first conductor and the second conductor.

4. The self-energizing protection device according to claim 1, wherein a second melt is connected in parallel to the driving melt, and the second melt melts when the driving melt melts, and the energy of the arc energy generated by the melting of the second melt drives the piston to displace to disconnect the first conductor and/or the second conductor.

5. The self-energizing protection device according to claim 1, wherein the drive melt is disposed in a flexible membrane ball, and when the drive melt melts, the generated arc energy can drive the flexible membrane ball to expand to drive the piston to displace to disconnect the first conductor and/or the second conductor.

6. The self-energizing protection device according to claim 1, wherein a hydraulic device is disposed between said drive melt and said piston, wherein when said drive melt melts, the generated arc energy drives said hydraulic device to operate, and said piston is driven by said hydraulic device to displace to disconnect said first and/or second conductors.

7. The self-energizing protection device of claim 1, wherein a third fuse element is connected in parallel to each of said first and second conductors, and wherein when said driving fuse element melts, the arc energy generated drives said piston to displace to open said first and/or second conductors and then to open said third fuse element.

8. The self-energizing protection device of claim 1, wherein said drive melt traps said spring means in a compressed state, and when said drive melt melts, the spring force of said spring means drives said piston to displace to disconnect said first and/or second conductors.

9. The self-energizing protection device according to claim 1, wherein the cavity in which the first conductor and the second conductor are disposed is filled with an arc-extinguishing medium, and the cavity in which the first conductor and the second conductor are disposed is opened with an opening through which the arc-extinguishing medium flows out of the cavity, and the opening is detachably blocked by a plug.

10. A self-energizing protection device according to any one of claims 1 to 9, wherein said piston closes a cavity in which said drive melt is located, and an arc-extinguishing medium is filled in said cavity.

11. A self-excitation protection device is characterized by comprising a first conductor and a second conductor which are insulated from each other, wherein a driving melt and a piston are connected in series between the first conductor and the second conductor; at least one first melt is connected in parallel with the driving melt; when the driving melt melts, the piston can be driven to displace to disconnect the first melt.

12. The self-energizing protection device according to claim 11, wherein said piston encloses a cavity in which said drive melt is located, said cavity being filled with an arc-quenching medium; and the cavity in which the first melt is located is filled with an arc extinguishing medium.