A high voltage, small size energizing fuse

Abstract

The application discloses a high-voltage and small-size excitation fuse, which comprises a shell, an excitation source arranged in the shell, a power device, a conductor penetrating through the shell and a fuse body arranged in the shell and connected in parallel with the conductor, wherein the impact end of the power device comprises at least two spaced-apart cutter heads, corresponding pre-breaking points are arranged on the conductor and the fuse body respectively and correspondingly to the positions of the cutter heads, the fuse body penetrates through an arc extinguishing chamber in the shell, and the fuse breaking weak position of the fuse body is located in the arc extinguishing chamber; under the drive of the excitation source, the power device can sequentially break the pre-breaking points on the conductor and the fuse body to form breaking points. The application has small size, and improves breaking capacity and arc extinguishing capacity.

Description

Technical Field

[0001] This invention relates to the fields of power and new energy, and in particular to the field of fuses for circuit protection, including fuses that achieve protection by mechanical means and thermal melting. Background Technology

[0002] Currently, there are two types of excitation fuses in the electric vehicle market: low voltage level, small size; and high voltage level, large size. However, with the trend of modularization and intelligence in battery packs, the requirements for the size of each component are becoming increasingly stringent, while the performance remains the same or even improves.

[0003] Currently, the two main battery pack protection solutions on the market are traditional thermal fuses and traditional thermal fuses combined with excitation fuses. Traditional fuses are protective devices that use the current-heat accumulation effect to melt and extinguish the arc at the current-sensing point (neck) of the fusible element within a certain time. Excitation fuses are fast-acting protective devices that use an electronic gas generator to push the insulator to cut the conductor, forming a physical break in a short time. The advantages of traditional fuses are maturity and stability, high breaking capacity, and strong arc-extinguishing capability. Their disadvantages include poor current surge resistance and high heat generation. They also require a long time to disconnect the circuit under low fault currents and cannot break below the rated current, thus failing to achieve fast protection. Excitation fuses offer the advantages of rapid protection through a quick-cutting opening, good current surge resistance, low heat generation, and complete physical isolation after disconnection. Their disadvantages include a relatively low breaking capacity due to the cutting opening alone and weak arc-extinguishing capability (relying on air cooling or compression for arc extinguishing). Summary of the Invention

[0004] The purpose of this invention is to provide an excitation fuse that improves the breaking capacity and arc extinguishing capacity of the excitation fuse by forming at least two breaks on the conductor and the molten element respectively; at the same time, it reduces the size of the fuse.

[0005] To address the aforementioned objectives, the present invention provides a high-voltage, small-volume excitation fuse, comprising a housing, an excitation source and a power device disposed within the housing, a conductor passing through the housing, and a molten element located within the housing and connected in parallel to the conductor. The impact end of the power device includes at least two spaced-apart cutting edges, with corresponding pre-breaks provided on the conductor and the molten element at positions corresponding to the cutting edges. The molten element passes through several arc-extinguishing chambers within the housing. Under the drive of the excitation source, the power device can sequentially disconnect the pre-breaks on the conductor and the molten element to form a fracture. The fracture of the molten element is located within the arc-extinguishing chambers.

[0006] Preferably, each of the pre-fracture points of the melt is provided with at least one set of push blocks and guide blocks, and the pre-fracture point of the melt is clamped between the push blocks and guide blocks; the arc-extinguishing chamber is provided between the push blocks and guide blocks and the shell, and the fracture formed after the pre-fracture point of the melt is broken is located in the arc-extinguishing chamber between the push blocks and guide blocks and the shell.

[0007] Preferably, the weakest point of the melt is located in the arc-extinguishing chamber.

[0008] Preferably, each pre-break of the conductor has a weak break point on both sides; an insulating protective sleeve is wrapped around each pre-break point, with both ends of the insulating protective sleeve located at the weak break point.

[0009] Preferably, the insulating protective sleeve includes an upper protective sleeve and a lower protective sleeve connected as one piece.

[0010] Preferably, each pre-break point of the conductor has a weak break point on one side and a weak rotation point on the other side; after the conductor breaks, a groove is provided at the bottom of the cavity into which the broken part of the conductor falls.

[0011] Preferably, the housing includes an excitation source housing and a power device housing, and a sealing device is provided between the contact surfaces of the excitation source housing and the power device housing.

[0012] Preferably, the shell includes a melt shell, a melt shell cover plate is provided on the melt shell, and the bottom of the melt shell is sealed by a bottom cover; a cavity is opened in the melt shell and the melt shell cover plate at the position of the double cutter head of the power device, the melt pre-cutting point is located in the cavity, and the push block and guide block are located in the cavity to clamp and fix the melt pre-cutting point; several arc-extinguishing chambers are formed between the melt shell and the melt shell cover plate, between the push block and the guide block and the melt shell, and between the melt shell cover plate; the melt is fixedly arranged between the melt shell cover plate and the melt shell and passes through the arc-extinguishing chambers.

[0013] Preferably, the housing further includes a first housing and a second housing that are sealed together, with the other end of the second housing sealed together with the melt housing and the melt housing cover plate; the conductor passes through the first housing and the second housing; and the excitation source and the power device are respectively disposed in the first housing.

[0014] Preferably, the housing further includes an excitation source housing and a power device housing that are sealed together, with the other end of the power device housing being sealed together with the melt housing cover plate; the conductor passes through the power device housing and the melt housing cover plate; the excitation source is housed in the excitation source housing, and the power device is housed in the power device housing.

[0015] Preferably, a limiting structure is provided between the contact surfaces of the melt shell and the bottom cover to prevent relative displacement.

[0016] Preferably, a positioning post is provided between the contact surfaces of the melt shell and the melt shell cover plate, and the melt passes through the positioning post for positioning and fixation.

[0017] The advantages of this invention are as follows: Firstly, multiple mechanical fractures are formed on the conductor and the parallel melt, and combined with the melt fracture, the arc generated at each fracture is reduced by utilizing the voltage division principle of the fracture, thereby improving the breaking capacity and arc extinguishing capacity. Simultaneously, arc extinguishing is achieved through an arc-extinguishing medium, with both the mechanically broken and melt-broken fractures on the melt being extinguished by the medium, further enhancing the arc extinguishing capacity. Furthermore, the presence of air chambers in the shell is reduced, lowering the requirements for shell strength. An insulating protective sleeve is fitted onto the pre-fractured conductor, establishing insulation protection at the moment of conductor breakage, rapidly cutting off the arc and preventing arc flame retardancy. The use of a single excitation source and a single power device to simultaneously form multiple fractures on the conductor and melt provides a prerequisite for a small volume. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure in the initial position of Example 1.

[0019] Figure 2 This is a schematic diagram of the structure after the power device in Embodiment 1 is activated.

[0020] Figure 3 This is a schematic diagram of the structure in the initial position of Example 2.

[0021] Figure 4 This is a schematic diagram of the structure after the power unit of Embodiment 2 is activated. Detailed Implementation

[0022] The above technical solutions will be explained in detail with reference to the illustrations.

[0023] Example 1

[0024] See Figure 1The housing includes a first housing 100 and a second housing 101 that are sealed together. A molten housing 102 is sealed together below the second housing 101, and the bottom of the molten housing 102 is sealed by a bottom cover 103. The housing is made of insulating material, and each housing is formed by injection molding, but other molding methods are also possible. A cavity is formed in both the first and second housings, extending through both ends of the first and second housings. A conductor 104 passes between the first and second housings, with its two ends located outside the housings, allowing it to be connected to an external circuit. The conductor located inside the housing passes through the cavity in the upper second housing. The conductor 104 is positioned by a limiting structure between the contact surfaces of the first and second housings, and a sealed contact is formed between the upper second housing and the conductor contact surface.

[0025] The upper part of the first housing cavity has a stepped hole structure, and the excitation source 105 is disposed in the stepped hole structure. A pressure sleeve 106 is pressed onto the outer circumferential surface of the first housing, and the excitation source 105 is fixed to the upper part of the first housing cavity by the pressure sleeve 106. The excitation source 105 is a gas generating device, which can receive excitation signals and act according to the received excitation signals to release high-pressure gas.

[0026] The power unit 107 is disposed in the cavity of the first housing, located on the drive end side of the excitation source 105. The power unit 107 includes an end that is in sealed contact with the cavity near the excitation source. A groove is formed on the outer circumferential surface of this sealed end, and a sealing ring 108 is disposed within the groove to seal the contact surface. The sealing ring ensures that the impact device and its cavity remain in sealed contact during displacement, preventing high-pressure gas from entering below the power unit, which could impede its movement and affect arc extinguishing. The power unit is interference-fitted with the cavity to limit its initial position. Alternatively, a limiting structure, such as a bump-groove structure, can be provided between the power unit and the cavity contact surface to limit the initial position. An arc-shaped concave structure is provided on the upper end face of the power unit. This arc-shaped concave structure aims to concentrate the high-pressure gas released from the excitation source directly onto the upper end face of the impact device, maximizing the driving force, while also reducing the weight of the impact device and saving materials.

[0027] In this embodiment, the power unit has a T-shaped structure, with its upper part completely sealed to the cavity it is in, while its lower part remains non-contact with the cavity. This design aims to reduce frictional resistance during the power unit's movement. To ensure linear displacement of the power unit within the cavity, a guide device is provided between the power unit and the cavity's contact surface. The guide device includes a groove and a slider disposed within the groove. The guide device ensures linear displacement of the power unit and prevents rotation within the cavity. Furthermore, to prevent incorrect installation, the depth or width of the groove and slider on one side can be made different from that on the other side.

[0028] The impact end of the power unit 107 near the conductor 104 has double cutting heads (109, 110), with a groove of a certain depth between the double cutting heads. The double cutting heads (109, 110) are at the same or different distances from the conductor 104. When the double cutting heads are at the same distance from the conductor 104, they can simultaneously break the conductor, forming multiple breaks on the conductor at the same time. When their distances are different, they break the conductor sequentially, forming multiple breaks on the conductor sequentially.

[0029] Conductor 104, made of conductive material, is located between the first and second housings. Conductor 104 is a long, plate-like structure with both ends extending outside the housing for connection to external circuits. It can be a straight plate or a U-shaped plate. Two weak points 104a are spaced apart on conductor 104 located in the cavity of the upper second housing. The conductor portion between the two weak points is supported by a support block 111b of the second housing. When the power device moves, the conductor portion between the two weak points and the support block enter the groove of the double-blade head, thus limiting the displacement position of the power device. A rotating weak point 104b is provided on the side of the weak point 104a near the housing wall. A pre-break is formed between the rotating weak point 104b and the adjacent weak point 104a. In this example, two pre-breaks are formed on the conductor. The double-blade head of the power device is positioned directly opposite the pre-break points of the conductor. When the conductor's pre-break point is subjected to impact from the double-bladed head, the conductor portion at the pre-break point breaks off at the weak point under the impact of the power device, and then bends along the weak point into the cavity of the second housing, forming two breaks on the conductor. The bottom of the cavity in the second housing for the conductor's broken portion to enter has a groove structure, allowing the conductor's broken portion to enter the groove part of the cavity under the drive of the power device. The groove structure limits the conductor's broken portion and prevents it from rebounding.

[0030] In this embodiment, each weak point is formed by V-shaped grooves corresponding to the upper and lower surfaces of the conductor. The purpose of the weak points and rotational weak points is to reduce the mechanical strength of the conductor at that point, with the mechanical strength of the rotational weak point being greater than that of the weak point. The weak points can be grooves to reduce mechanical strength, variable cross-section structures with thinner or narrower cross-sections, through-hole structures arranged in rows at intervals, overlapping structures, etc.

[0031] A melt shell 102 is provided with a melt shell cover plate 112, which is in sealed contact with the melt shell, forming at least one sealed arc-extinguishing chamber 113 within the melt shell, which is filled with an arc-extinguishing medium. Corresponding cavities are formed in the melt shell and melt shell cover plate at the locations of the dual-blade positions of the corresponding power unit. A melt 114 is fixed between the melt shell and the melt shell cover plate. A positioning post 111a is provided between the melt shell and the melt shell cover plate, and a corresponding through hole is provided on the melt. The positioning post 111a passes through the through hole in the melt to fix the melt between the melt shell and the melt shell cover plate.

[0032] After passing through the cavity and arc-extinguishing chamber on the melt shell, the molten material 114 passes through the melt shell, the melt shell cover plate, and the second shell at both ends and is electrically connected to the conductor. In this embodiment, both pre-break points of the conductor are located between the two ends of the melt. The melt and the conductor are electrically connected by screws 115, or by welding, riveting, or other elastic contact methods. A weak point is provided on the melt in the arc-extinguishing chamber. The weak point is a narrow neck or a metallurgical effect point. When the melt breaks, it breaks at the weak point in the arc-extinguishing chamber. In the design, one of the pre-break points only needs to be located between the two ends of the melt.

[0033] Weak points are provided on both sides of the melt in the cavity corresponding to the cutter head of the power unit within the melt shell 102, forming a pre-fracture in the melt portion within the cavity. Push blocks 116 and guide blocks 117 are respectively provided on the upper and lower surfaces of the melt in the cavity. Limiting protrusions are provided on the push blocks and guide blocks, which are engaged in limiting grooves on the melt shell to define their initial positions. The push blocks and guide blocks are in sealed contact with the cavity. An arc-extinguishing chamber 102a is formed between the melt shell, the melt cover plate, and the push blocks and guide blocks, filled with an arc-extinguishing medium. The weak point at the pre-fracture of the melt is located within the arc-extinguishing chamber 102a. When the melt mechanically breaks, the fracture formed by the mechanical break is also located at the arc-extinguishing medium 102a, and the arc generated at the fracture is extinguished by the arc-extinguishing medium.

[0034] The pusher block and guide block are interlocked. For example, the pusher block has a protrusion, the guide block has a groove, and the melt has a corresponding through hole. The protrusion of the pusher block passes through the through hole in the melt and then nests into the groove of the guide block, fixing the melt between the pusher block and the guide block. Each cutter head of the power unit corresponds to a set of pusher blocks and guide blocks located in a cavity.

[0035] A limiting groove is made on the bottom end face of the melt shell, and a limiting protrusion is made at the corresponding position of the bottom cover. The bottom cover is placed on the bottom of the melt shell, and the limiting protrusion of the bottom cover is located in the limiting groove at the bottom of the melt shell, which seals and fixes the position of the melt shell and prevents the bottom cover from moving relative to the melt shell.

[0036] The workflow and principle of this embodiment are as follows: See Figure 1 and Figure 2 The excitation source operates according to the received excitation signal, releasing high-pressure gas to drive the power device to overcome the limiting structure or interference fit and move to the conductor pre-break point. The double cutter head of the power device disconnects the corresponding pre-break point, forming two breaks on the conductor. Since there is molten material connected in parallel on the conductor, when two breaks are formed on the conductor, nearly 70% of the fault current flows through the molten material. Therefore, the arc generated at the conductor break point is very small, and the arc can be extinguished by air. The power device continues to move, driving the disconnected part of the conductor into the cavity of the second shell. At the same time, the double cutter head of the power device enters the cavity of the molten material shell and drives the push block and guide block corresponding to the double cutter head of the power device to overcome the limiting structure and move, pulling the molten material apart. Four mechanical breaks are formed on the molten material in different cavities in the molten material shell. The broken part of the molten material is located at the arc extinguishing chamber, where the arc is extinguished by the arc extinguishing medium. At the same time, the broken molten material is squeezed between the push block and the cavity, and the arc is also extinguished by compression. When the fault current is small and insufficient to melt the molten metal, only four mechanical fractures are formed on the molten metal. The arc generated at these fractures is very small and can be easily extinguished by air and pressure. When the fault current is large, four more mechanical fractures are formed on the molten metal at the same time as the melting fracture, resulting in at least five fractures. These five fractures are connected in series, and the voltage at each fracture is reduced proportionally. Consequently, the arc generated at the fractures is also reduced, and combined with the arc-extinguishing medium, the arc can be extinguished quickly.

[0037] As can be seen from the above, the structure of this embodiment, which adopts a power device with a double-blade structure and forms at least a plurality of mechanical breaks on the conductor and the molten material respectively, can reduce the structural volume of the excitation fuse and improve the breaking voltage and arc extinguishing capability.

[0038] Example 2

[0039] See Figure 3 and Figure 4 The difference from Embodiment 1 is that the first housing includes an excitation source housing 130 for housing the excitation source and a power device housing 131 for housing the power device. The second housing is replaced by a melt housing cover plate 137, which is sealed and connected to the power device housing 131. A conductor 104 passes between the power device housing 131 and the melt housing cover plate 137.

[0040] The contact surfaces between the excitation source housing and the power unit housing are in a sealed contact. This can be achieved through a sealing structure, such as nested grooves and protrusions between the contact surfaces, or by using a sealing device, such as a sealing ring. In this example, a sealing ring 132 is provided at the stepped surface where the excitation source housing and the power unit housing contact to seal the contact surface. A protective cover 133 is pressed onto the outer circumferential surface of the excitation source housing 130 to fix the excitation source 105.

[0041] The conductor 104 has no rotational weak points, only disconnection weak points 104a. Four disconnection weak points 104a are spaced apart on the conductor, and a pre-break 104c is formed between two adjacent disconnection weak points 104a. The conductor between two pre-break 104c is supported by a support block 111c. An insulating protective sleeve 135 is provided on the pre-break 104c.

[0042] The insulating protective sleeve 135 includes an upper protective sleeve and a lower protective sleeve clamped on the upper and lower sides of the conductor pre-break. The upper and lower protective sleeves can be separate structures, connected as a single unit via snap-fits or other means, or they can be a single unit fitted onto the pre-break. The two ends of the insulating protective sleeve are located at the thinnest points of the conductor break. The insulating protective sleeve is fitted snugly against the conductor. The insulating protective sleeve ensures no excess air at the conductor pre-break; after the pre-break, the insulating protective sleeve covers the broken portion of the conductor to the maximum extent possible.

[0043] The impact end of the power unit 107 has a double-blade structure with a square columnar shape, which matches the shape of the cavity on the melt shell and the melt shell cover plate.

[0044] In this embodiment 2, the structures of the melt shell and the melt shell cover plate differ from those in embodiment 1. In this embodiment 2, the melt shell 136 and the melt shell cover plate 137 are sealed together, and through holes are provided on the melt shell cover plate 137 for the two ends of the melt 114 to pass through. On the conductor 104, a pre-break 104c with an insulating protective sleeve 135 is located at the cavity opening end of the melt shell cover plate and the melt shell. The shape of the pre-break 104 with the insulating protective sleeve 135 matches the shape of the cavity in the melt shell and the melt shell cover plate. When the pre-break 104c breaks, it can enter the cavity in the melt shell and the melt shell cover plate and make sealed contact with the cavity.

[0045] Several sealed arc-extinguishing chambers 136b are also formed on one side of the positioning post 136a, between the melt shell 136, the melt shell cover plate 137, and the push block and guide block. Several arc-extinguishing chambers 136c are formed between the melt shell 136 and the melt shell cover plate 137. The melt 114 passes through several arc-extinguishing chambers 136b and 136c, with both ends of the melt 114 passing through through holes on the melt shell cover plate 137 and connected in parallel with the conductor. The melt in each arc-extinguishing chamber has the same weak point as in Example 1, and the weak point at the pre-fracture of the melt is located in arc-extinguishing chamber 136b. Each arc-extinguishing chamber is filled with an arc-extinguishing medium. The fracture surfaces formed by melt melting or mechanical breakage are all located in the arc-extinguishing chambers, allowing the arc generated at the melt fracture surface to be extinguished by the arc-extinguishing medium.

[0046] The operation flow and principle of this embodiment are as follows:

[0047] The excitation source operates according to the received excitation signal, releasing high-pressure gas to drive the power device to overcome the limiting structure or interference fit, displacing it to the conductor pre-break point. The power device's double cutter heads disconnect the corresponding pre-break points, forming two breaks on the conductor. Because a molten metal is connected in parallel on the conductor, when two breaks are formed, nearly 70% of the fault current flows through the molten metal. Therefore, the arc generated at the conductor break point is very small, and air can extinguish the arc at the conductor break point. After the conductor breaks, an insulating protective sleeve is fitted over the broken part of the conductor, so that only the smallest cross-section of the two ends of the broken part is exposed outside the insulating protective sleeve. The broken part of the conductor, with the insulating protective sleeve, enters the cavity along the guide device in the shortest possible time. The two ends of the broken part of the conductor are in close contact with the cavity, squeezing the arc. At the same time, the insulating protective sleeve and the cavity combine to insulate the broken part of the conductor, quickly cutting off the arc generated at the break point.

[0048] The power unit continues to move, driving the conductor with the insulating protective sleeve to displace the disconnected portion. This drives the corresponding push block and guide block to move after overcoming the limiting structure, breaking the molten metal. Four mechanical fractures are formed on the molten metal in different cavities within the molten metal shell. These mechanical fractures are located at the arc-extinguishing chambers, where the arc is extinguished by the arc-extinguishing medium. The broken molten metal, along with the displacement of the push block and guide block, is squeezed between the contact surfaces of the push block and guide block and the cavities, extinguishing the arc through compression. When the fault current is small and insufficient to melt the molten metal, only four mechanical fractures are formed on the molten metal. The arc generated at these fractures is very small and easily extinguished by the arc-extinguishing medium. When the fault current is large, four more mechanical fractures are formed on the molten metal simultaneously with the melting and fracture formation, resulting in at least five fractures on the molten metal. The five breaks are connected in series, and the voltage at each of the five breaks is reduced by a factor of two, which reduces the arc generated at the breaks. Since the breaks in the melt are all in the arc-extinguishing medium, the arc can be extinguished quickly by using the arc-extinguishing medium.

Claims

1. A high-voltage, small-volume excitation fuse, comprising a housing, an excitation source and a power device disposed within the housing; a conductor passing through the housing and a fusible element located inside the housing and connected in parallel to the conductor, characterized in that, The impact end of the power device includes at least two spaced-apart cutters. Corresponding pre-breaks are provided on the conductor and the melt at positions corresponding to the cutter positions. The melt passes through several arc-extinguishing chambers in the housing. Under the drive of the excitation source, the power device can sequentially disconnect the pre-breaks on the conductor and the melt, forming at least two breaks on the conductor and the melt simultaneously. The melt breaks are located in the arc-extinguishing chambers.

2. The high-voltage, small-volume excitation fuse according to claim 1, characterized in that, At least one set of push blocks and guide blocks are provided at each melt pre-fracture point, and the melt pre-fracture point is clamped between the push blocks and guide blocks; the arc extinguishing chamber is provided between the push blocks and guide blocks and the shell, and the fracture formed after the melt pre-fracture point is broken is located in the arc extinguishing chamber between the push blocks and guide blocks and the shell.

3. The high-voltage, small-volume excitation fuse according to claim 1, characterized in that, The weakest point of the melt is located in the arc-extinguishing chamber.

4. The high-voltage, small-volume excitation fuse according to claim 2, characterized in that, Each pre-break point of the conductor has a weak break point on both sides; an insulating protective sleeve is wrapped around each pre-break point, with both ends of the insulating protective sleeve located at the weak break point.

5. The high-voltage, small-volume excitation fuse according to claim 4, characterized in that, The insulating protective sleeve includes an upper protective sleeve and a lower protective sleeve connected as one piece.

6. The high-voltage, small-volume excitation fuse according to claim 1, characterized in that, Each pre-break section of the conductor has a weak break point on one side and a weak rotation point on the other side; after the conductor breaks, a groove is provided at the bottom of the cavity into which the broken part of the conductor falls.

7. The high-voltage, small-volume excitation fuse according to claim 1, characterized in that, The housing includes an excitation source housing and a power unit housing, and a sealing device is provided between the contact surfaces of the excitation source housing and the power unit housing.

8. The high-voltage, small-volume excitation fuse according to any one of claims 1 to 7, characterized in that, The shell includes a melt shell, on which a melt shell cover plate is provided, and the bottom of the melt shell is sealed by a bottom cover; a cavity is opened in the melt shell and the melt shell cover plate at the position of the double cutter head of the power device, the melt pre-cutting point is located in the cavity, and the push block and guide block are located in the cavity to clamp and fix the melt pre-cutting point; several arc-extinguishing chambers are formed between the melt shell and the melt shell cover plate, between the push block and the guide block and the melt shell, and between the melt shell cover plate; the melt is fixedly arranged between the melt shell cover plate and the melt shell and passes through the arc-extinguishing chambers.

9. The high-voltage, small-volume excitation fuse according to claim 8, characterized in that, The housing also includes a first housing and a second housing that are sealed together, with the other end of the second housing sealed together with the melt housing and the melt housing cover plate; the conductor passes through the first housing and the second housing; the excitation source and the power device are respectively disposed in the first housing.

10. The high-voltage, small-volume excitation fuse according to claim 8, characterized in that, The housing also includes a sealed excitation source housing and a power device housing, with the other end of the power device housing sealed to the melt housing cover plate; the conductor passes through the power device housing and the melt housing cover plate; the excitation source is housed in the excitation source housing, and the power device is housed in the power device housing.

11. The high-voltage, small-volume excitation fuse according to any one of claims 9 or 10, characterized in that, A limiting structure is provided between the contact surfaces of the melt shell and the bottom cover to prevent relative displacement.

12. The high-voltage, small-volume excitation fuse according to any one of claims 9 or 10, characterized in that, A positioning post is provided between the contact surface of the melt shell and the melt shell cover plate, and the melt is positioned and fixed by passing through the positioning post.

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