Electrical loop protection device

Abstract

The invention relates to the field of circuit protection and electric automobiles, in particular to an electrical loop protection device which comprises a first excitation fuse and a first mechanical switch, the first excitation fuse can be connected into an electrical loop in a series connection mode, and the first mechanical switch and the first excitation fuse are connected in parallel to form a first reset branch; in an initial working state, the first excitation fuse is in a conducting state, and the first mechanical switch is in a normally open state; when the electrical loop has a fault current or the current exceeds a threshold value for the first time, the first excitation fuse acts according to a received trigger signal and disconnects the electrical loop for the first time, and when the electrical loop reaches a reset condition, the first mechanical switch is closed according to a received closing instruction, so that the first reset branch is connected to the electrical loop in a conducting manner, and the electrical loop is reset. And the electrical loop is conducted again for the first time. According to the electrical loop protection device, disconnection and resetting of an electrical loop can be achieved, the maintenance and replacement time is shortened, and the working efficiency and economic benefits are improved.

Description

Technical Field

[0001] The invention relates to the field of circuit protection and electric vehicles, and in particular to a protection device for an electric circuit. Background Art

[0002] At present, the protection of the main circuit and charging circuit of electric vehicles mainly relies on fuses. When an overload fault such as a short circuit occurs in the circuit, the fuse will be activated to disconnect the electrical circuit for protection. In order to speed up the protection response speed, excitation fuses are currently mainly used for protection in electric vehicles. The excitation fuse mainly includes an excitation source, a piston, and a conductive plate with two connection ends. The conductive plate can be connected in series to the electrical circuit. The excitation source is a gas generating device. According to the received trigger signal, the excitation source ignites and releases high-pressure gas as a driving force, driving the piston to move and cut off the conductive plate, thereby disconnecting the electrical circuit for protection. The trigger signal can be sent through an external trigger circuit or through an internally integrated trigger detection module. For example, the excitation fuse structure in an excitation fuse with an integrated arc-extinguishing fuse disclosed in Chinese Patent 2019222547413.

[0003] The protection for electrical circuit overload faults is already mature, but since the fuse cannot be restored after it is actuated, the electrical circuit becomes invalid after it is disconnected. Even if the circuit is tested and has reset conditions, the main circuit or charging circuit cannot be restored immediately, affecting normal operation. It must be repaired to find the actuated fuse and replace it before it can be restored. In addition, the DC charging circuit of some electric vehicles is connected in series with the main circuit. Due to the large charging current, when the charging circuit is short-circuited or overloaded due to external factors (such as charging pile failure), the main circuit fuse will be actuated, making it impossible to charge the charging circuit again, resulting in poor user experience and high maintenance costs for the car factory. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an electrical circuit protection device, which can disconnect the electrical circuit immediately when a short circuit, overload or other fault occurs, and can automatically restore the electrical circuit when the electrical circuit meets the reset condition, without the need to check which fuse in the electrical circuit is disconnected and then perform repair and replacement. By automatically restoring the conduction of the electrical circuit, the time for finding the disconnection point and repair and replacement is avoided, and the electrical circuit can be automatically restored as long as it meets the reset condition, thereby improving user experience and economic benefits.

[0005] To solve the above technical problems, the present invention provides an electrical circuit protection device, comprising: a first excitation fuse and a first mechanical switch, wherein the first excitation fuse can be connected to the electrical circuit in series, and the first mechanical switch is connected in parallel with the first excitation fuse to form a first reset branch; in the initial working state, the first excitation fuse is in a conducting state, and the first mechanical switch is in a normally open state; when a fault current appears in the electrical circuit for the first time or the current exceeds a threshold, the first excitation fuse is actuated according to the received trigger signal to disconnect the electrical circuit for the first time, and when the electrical circuit reaches the reset condition, the first mechanical switch is closed according to the received closing instruction, so that the first reset branch is conductively connected to the electrical circuit, and the electrical circuit is reopened for the first time.

[0006] Preferably, the first reset branch also includes a first circuit protection device, which is connected in series with the first mechanical switch; in the initial working state, the first circuit protection device is in an on state; when a fault current appears in the electrical circuit for the second time or the current exceeds a threshold, the first electrical protection device is actuated to disconnect the first reset branch and disconnect the electrical circuit for the second time.

[0007] Preferably, a second mechanical switch is connected in parallel at both ends of the first excitation fuse or at both ends of the first circuit protection device to form a second reset branch; when the second mechanical switch is connected in parallel at both ends of the first circuit protection device, the second mechanical switch is connected in series with the first mechanical switch; in the initial working state, the second mechanical switch is in a normally open state; when the electrical circuit that is disconnected for the second time reaches the reset condition, the second mechanical switch is closed according to the received closing instruction, so that the second reset branch is conductively connected to the electrical circuit, and the electrical circuit is reopened for the second time.

[0008] Preferably, the second reset branch also includes a second circuit protection device, which is connected in series with the second mechanical switch, wherein one end of the second circuit protection device is connected to one end of the first circuit protection device, and the other end of the second circuit protection device is connected to the second mechanical switch; in the initial working state, the second circuit protection device is in an on state; when a fault current appears in the electrical circuit for the third time or the current exceeds a threshold, the second electrical protection device is actuated to disconnect the second reset branch, thereby disconnecting the electrical circuit for the third time.

[0009] Preferably, it also includes a third reset branch, and the third reset branch is a third mechanical switch connected in parallel at both ends of the first excitation fuse, or at both ends of the second reset branch, or at both ends of the second circuit protection device; when the second reset branch is connected in parallel to the first circuit protection device and the third mechanical switch is connected in parallel to both ends of the second reset branch, the third mechanical switch is connected in series with the first mechanical switch; when the third mechanical switch is connected in parallel to the second circuit protection device, the third mechanical switch is connected in series with the second mechanical switch; in the initial working state, the third mechanical switch is in a normally open state; when the electrical circuit that is disconnected for the third time reaches the reset condition, the third mechanical switch is closed according to the received closing instruction, so that the third reset branch is conductively connected to the electrical circuit, and the electrical circuit is reopened for the third time.

[0010] Preferably, the third reset branch also includes a third circuit protection device, which is connected in series with the third mechanical switch, wherein one end of the third circuit protection device is connected to one end of the second circuit protection device, and the other end of the third circuit protection device is connected to the third mechanical switch; in an initial working state, the third circuit protection device is in an on state; when a fault current appears in the electrical circuit for the fourth time or the current exceeds a threshold, the third electrical protection device is actuated to disconnect the third reset branch and disconnect the electrical circuit for the fourth time.

[0011] Preferably, the first mechanical switch, the second mechanical switch and the third mechanical switch respectively include a driving mechanism and a mechanical contact system; the mechanical contact system includes a static contact and a moving contact; in the initial working state, the moving contact is insulated from the static contact; the driving mechanism actuates according to the received closing instruction to drive the moving contact to make conductive contact with the static contact.

[0012] Preferably, the static contact is a soft-connection type static contact.

[0013] Preferably, the driving mechanism is a permanent magnet mechanism, an electromagnetic mechanism or an excitation closing mechanism; when it is a permanent magnet mechanism or an electromagnetic mechanism, the moving contact is driven to be in conductive contact with the static contact by the moving iron core of the permanent magnet mechanism or the electromagnetic mechanism; when it is an excitation closing mechanism, the excitation closing mechanism includes an excitation source and a piston, the excitation source operates according to the received closing instruction, releases a driving force, the driving force drives the piston, and the piston drives the moving contact to be in conductive contact with the static contact.

[0014] Preferably, when the driving mechanism is a permanent magnet mechanism or an electromagnetic mechanism, an insulating partition is provided between the driving mechanism and the moving contact.

[0015] Preferably, it also includes a detection control module, the detection output end of the detection control module is connected to the first excitation fuse signal receiving end; the detection control module detects the current signal of the electrical circuit by electromagnetic induction; when a fault current occurs in the electrical circuit or the current exceeds a threshold, the detection output end of the detection control module sends a trigger signal, and according to the order in which the detection output end of the detection control module sends the trigger signal, the electrical circuit protection device performs one of the following actions: the first excitation fuse disconnects the electrical circuit for the first time according to the received trigger signal; or, the first circuit protection device disconnects the electrical circuit for the second time according to the received trigger signal; or, the second circuit protection device disconnects the electrical circuit for the third time according to the received trigger signal, or, the third circuit protection device disconnects the electrical circuit for the fourth time according to the received trigger signal.

[0016] Preferably, the first circuit protection device, the second circuit protection device and the third circuit protection device are at least one of a fuse, a thermal fuse and an excitation fuse.

[0017] Preferably, when at least one of the first circuit protection device, the second circuit protection device and the third circuit protection device is a fuse, a stationary contact of a stationary contact of a mechanical switch connected in series with the fuse is arranged on the fuse.

[0018] Preferably, when at least one of the first circuit protection device, the second circuit protection device and the third circuit protection device is an excitation fuse, a trigger signal of the circuit protection device set to be the excitation fuse and a common trigger signal of the first excitation fuse, and an output end of the trigger signal is conductively connected to a signal receiving end of the first excitation fuse.

[0019] The electrical circuit protection device of the present invention realizes the disconnection protection of the electrical circuit and the automatic recovery after disconnection by stimulating the parallel setting of the fuse and the mechanical switch, thereby avoiding the steps of finding the disconnection position of the fuse and repairing and replacing the fuse, shortening the maintenance time of the first disconnection of the electrical circuit, and improving the working efficiency and economic benefits of the electrical circuit.

[0020] By setting the driving mechanism, the miniaturized design of the device can be realized on the basis of completing reliable closure, especially in the height direction of the device.

[0021] The static contact end of the mechanical switch uses the connection end of one end of the excitation fuse. Considering the impact of the action process, a flexible connection method can be used at one end of the static contact, such as a soft-connection static contact, which can be realized by copper foil or copper braid. That is, a flexible static contact is set at the connection end of the excitation fuse through copper foil or copper braid to reduce the impact when the moving and static contacts contact, protect the connection end of the excitation fuse, and improve the stability of the protection device. Silver alloy contacts can be used for the moving contact and the static contact, preferably silver tin oxide, to enhance the contact effect and reduce the contact resistance.

[0022] The protection device can be installed between the drive mechanism and the moving contact to set up an independent secondary circuit compartment, which can be physically insulated from the main electrical circuit, improve the insulation withstand voltage level, reduce the size of the device, achieve miniaturization, and improve product reliability.

[0023] The electrical circuit protection device provided by the present invention, when considered to be set in the electrical circuit of an electric vehicle, can cut off the circuit where the electrical circuit protection device is located when an overcurrent fault such as a short circuit occurs, and restore the electrical circuit after the equipment self-checks and meets the reset conditions.

[0024] The electrical circuit protection device provided in the present application, when used as a protection device for the main circuit, can avoid the situation where the line is cut off and cannot work again due to occasional faults, and provide the circuit with the ability to recover at least once after functional testing.

[0025] When used as a protection device for the charging circuit, the user can charge normally after replacing the charging pile with a fault-free one. At the same time, in order to cope with the same fault again, the electrical circuit protection device can also be set to allow more than two cuts before resetting the conduction, and the last cut can be on the charging circuit without affecting the main circuit fuse. During maintenance, only the module of the charging circuit protection device needs to be replaced, and there is no need to repair or replace the high-voltage box. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the principle structure of an embodiment of the electrical circuit protection device of the present application, that is, a schematic diagram of the principle structure of a first mechanical switch 20 connected in parallel to a first excitation fuse 10 to form a first reset branch.

[0027] Figure 2 is Figure 1 On the basis of, a first circuit protection device is connected in series in the first mechanical switch 20 in the first reset branch, and the first circuit protection device is a schematic diagram of the principle structure of a fuse.

[0028] Figure 3 is Figure 1Based on the principle structure diagram of the invention, a first circuit protection device is connected in series to a first mechanical switch 20 in a first reset branch, and the first circuit protection device is a second excitation fuse 11.

[0029] Figure 4 is Figure 3 On the basis of, a second mechanical switch 21 is connected in parallel to the second excitation fuse 11 in the first reset branch to form a schematic diagram of the principle structure of the second reset branch.

[0030] Figure 5 is Figure 4 Based on the principle structural diagram of the invention, a second circuit protection device is connected in series in the second reset branch, and the second circuit protection device is a fuse.

[0031] Figure 6 is Figure 4 Based on the principle structure diagram of the invention, a second circuit protection device is connected in series in the second reset branch, and the second circuit protection device is a third excitation fuse.

[0032] Figure 7 yes Figure 1 A schematic structural diagram of an electrical circuit protection device according to the illustrated embodiment.

[0033] Figure 8 yes Figure 2 A schematic structural diagram of an electrical circuit protection device according to the illustrated embodiment.

[0034] Fig. 9 This is a schematic diagram of the structure between the driving mechanism and the static contact in the electrical circuit protection device of the present application when the driving mechanism is a permanent magnet mechanism or an electromagnetic mechanism.

[0035] Fig.10 This is a schematic diagram of the structure between the driving mechanism, the static contact and the excitation fuse when the driving mechanism is an excitation closing mechanism in the electrical circuit protection device of the present application.

[0036] Fig.11 yes Figure 3 A schematic diagram of the appearance and structure of an electrical circuit protection device of the illustrated embodiment.

[0037] Fig.12 yes Fig.11 A schematic diagram of the exploded structure of the electrical circuit protection device of the illustrated embodiment.

[0038] Fig.13 It is a principle structure diagram of the electrical circuit protection device of the present application, in which the first reset branch and the second reset branch are respectively connected in parallel to the first excitation fuse.

[0039] Fig.14It is a principle structural diagram of the electrical circuit protection device of the present application, in which the first reset branch and the second reset branch are respectively connected in parallel to the first excitation fuse, and the second reset branch is also connected in series with the second circuit protection device.

[0040] Fig.15 It is a principle structural diagram of the electrical circuit protection device of the present application in which the second reset branch and the third reset branch are respectively connected in parallel at the two ends of the first circuit protection device in the first reset branch.

[0041] Fig.16 This is a principle structural diagram of the electrical circuit protection device of the present application, in which the first reset branch and the third reset branch are respectively connected in parallel at both ends of the first excitation fuse, and the second reset branch is connected in parallel at both ends of the first circuit protection device of the first reset branch.

[0042] Fig.17 It is a schematic diagram of the principle structure of the electrical circuit protection device of the present application, in which the first reset branch and the second reset branch are respectively connected in parallel at both ends of the first excitation fuse, and the third reset branch is connected in parallel at both ends of the second circuit protection device of the second reset branch.

[0043] Fig.18 It is a schematic diagram of the principle structure of the electrical circuit protection device of the present application, in which the first reset branch, the second reset branch, and the third reset branch are respectively connected in parallel at both ends of the first excitation fuse.

[0044] Reference numerals:

[0045] The first excitation fuse 10, the second excitation fuse 11, the third excitation fuse 12, the first mechanical switch 20, the second mechanical switch 21, the third mechanical switch 22, the first fuse 30, the second fuse 31, the moving contact 40, the static contact 50, the drive mechanism 60, the insulating partition 61, the detection control module 70, the shell 100, the connection end 101 of the first excitation fuse 10, the conductive connecting plate 102, the first reset branch 81, the second reset branch 82, the third reset branch 83, the first circuit protection device 91, and the second circuit protection device 92. DETAILED DESCRIPTION

[0046] With respect to the above technical solution, preferred embodiments are now cited and specifically described in conjunction with drawings.

[0047] The electrical circuit protection device of the present invention is shown in FIG. Figure 1 , Figure 1The schematic diagram of the principle structure of an embodiment of the electrical circuit protection device of the present application is shown, which includes a first excitation fuse 10 that can be connected in series with the electrical circuit, a first mechanical switch 20 is connected in parallel to the first excitation fuse 10, and the branch where the first mechanical switch 20 is located forms a first reset branch. When the electrical circuit is in a normal working state (i.e., in the initial working state of the electrical circuit protection device), the first excitation fuse 10 is in a conducting state, and the first mechanical switch 20 is in a normally open state; when a fault current occurs in the electrical circuit or the current exceeds a set threshold, the first excitation fuse 10 is actuated to disconnect the electrical circuit connected in series with it, thereby protecting the electrical circuit. At this time, the first reset branch where the first mechanical switch 20 is located is in an open state. When the disconnected electrical circuit reaches the reset condition, the first mechanical switch 20 is actuated according to the received external closing command, and the first mechanical switch 20 is switched from normally open to normally closed, connecting the disconnected electrical circuit, so that the electrical circuit is in a working state again.

[0048] Each excitation fuse in the present application, including the first excitation fuse, etc., mainly includes an excitation source, a piston, a conductive plate, and terminals connected to the two ends of the conductive plate that can be connected to the electrical circuit. The excitation fuse can be activated according to the received trigger signal, release the driving force, drive the piston to move through the driving force, disconnect the conductive plate, and realize the disconnection of the excitation fuse. The excitation fuse structure is a prior art, and its specific structure will not be repeated in this application.

[0049] In the present application, the trigger signal of each excitation fuse may be a trigger signal sent by a trigger control source outside the electrical circuit protection device, or may be a trigger signal sent by a detection control module 70 integrated in the electrical circuit protection device. Fig.12 The trigger signal output terminal is conductively connected to the signal receiving terminal of the first excitation fuse 10 .

[0050] The detection control module 70 is used to detect the current signal of the electrical circuit by electromagnetic induction. When the current of the electrical circuit detected by the detection control module 70 is a fault current or the current exceeds a set threshold, the signal transmission end of the detection control module 70 sends a trigger signal to the first excitation fuse 10, and the first excitation fuse 10 is actuated according to the received trigger signal to disconnect the electrical circuit. The structure of the detection control module 70 for detecting the current signal of the electrical circuit by electromagnetic induction is a prior art and will not be described in detail here.

[0051] The mechanical switch of the present application includes a driving mechanism and a mechanical contact system, and the mechanical contact system includes a moving contact and a static contact. The static contact is preferably a soft-connected static contact, and the soft-connected static contact includes a flexible structure and a static contact point, and the flexible structure is a conductive structure such as copper foil, copper braided belt, copper belt, copper silver belt, etc., and the static contact point is arranged on the flexible structure. The contacts of the moving contact and the static contact can use silver alloy contacts, preferably silver tin oxide, to enhance the contact effect and reduce the contact resistance. The use of a soft-connected static contact can reduce part of the impact energy of the moving contact, and play a role in shock and vibration reduction. In the initial working state, the moving contact and the static contact of the mechanical contact system are in an insulated disconnected state. The driving mechanism can act according to the closing instruction sent by the client to drive the mechanical contact system to conduct. The driving mechanism is a permanent magnet mechanism, an electromagnetic mechanism or an excitation closing mechanism. The excitation closing mechanism mainly includes an excitation source and a piston, and the excitation source is a gas generating device. The excitation source can be activated according to the received trigger signal, release the driving force, drive the piston to move through the driving force, and then drive the movable contact of the mechanical contact system to make conductive contact with the static contact through the displaced piston, so as to realize the conduction of the mechanical switch. The structure of the excitation closing mechanism is also prior art and will not be described in detail here.

[0052] When it is a permanent magnet mechanism or an electromagnetic mechanism, according to the closing instruction sent by the control end of the client, the moving contact is driven to make conductive contact with the static contact through the moving iron core of the permanent magnet mechanism or the electromagnetic mechanism. When the driving mechanism is an excitation closing mechanism, the excitation source of the excitation closing mechanism uses the received external closing instruction as a trigger signal to release the driving force, drive the piston to move, and the piston drives the moving contact to make conductive contact with the static contact to realize the closing and conduction of the mechanical switch.

[0053] The external closing command means that when the client uses the electrical circuit protection device of the present application, the client's control circuit can be connected to the driving mechanism of the mechanical switch and send an electrical signal to it as a closing command. The specific details depend on the client design.

[0054] Figure 1 Working principle of the illustrated embodiment:

[0055] Under normal working conditions, the first excitation fuse 10 is in the on state. After being connected in series to the electrical circuit, the electrical circuit is in the on state. The first mechanical switch 20 is in the normally open state, and the first reset branch where it is located is in the disconnected state. When a short circuit, overload or other fault current or current exceeds a set threshold in the electrical circuit, the external trigger control source or the internal integrated detection control module 70 sends a trigger signal to the first excitation fuse 10, and the first excitation fuse 10 is actuated to cut off the conductive plate in the first excitation fuse 10, thereby disconnecting the electrical circuit. When the disconnected electrical circuit reaches the reset condition, the first mechanical switch 20 is actuated according to the received external closing command, and the first mechanical switch 20 is switched from normally open to normally closed, so that the first reset branch is turned on, and the electrical circuit is reopened through the first reset branch where the first mechanical switch 20 is located.

[0056] pass Figure 1 The principle structure can realize the cutting off and resetting of the electrical circuit. Figure 1 The principle of the first excitation fuse 10 connected in parallel with the first mechanical switch 20 can be integrated to form a protection device module, see Figure 7 The first excitation fuse 10 and the first mechanical switch 20 are both integrated in the housing 100, and the connection end 101 of the first excitation fuse 10 is located outside the housing 100, forming a modular structure, which can be easily installed and repaired and replaced.

[0057] Figure 1 In the embodiment, when the disconnected electrical circuit is reset and connected by the first mechanical switch 20, since there is no circuit protection device, when a fault current occurs again in the electrical circuit or the current exceeds the set threshold, the electrical circuit cannot be cut off immediately for protection.

[0058] In some embodiments, in order to protect the electrical circuit where the fault current reoccurs or the current exceeds the set threshold, the first circuit protection device can be connected in series in the first reset branch where the first mechanical switch 20 is located. The first circuit protection device and the first mechanical switch 20 are connected in series, that is, one end of the first mechanical switch 20 is conductively connected to one end of the first excitation fuse 10, the other end of the first mechanical switch 20 is conductively connected to one end of the first circuit protection device, and the other end of the first circuit protection device is conductively connected to the other end of the first excitation fuse 10. Figure 2 , Figure 3 In the embodiment shown, Figure 2 , Figure 3 In the embodiments shown, Figure 1 The embodiment structure is based on Figure 1 In the embodiment shown, a first circuit protection device is connected in series with the mechanical switch (ie, the first mechanical switch). Figure 2 As shown in , the first circuit protection device can be configured as a first fuse 30; for example Figure 3 As shown in , the first circuit protection device can be set as the second excitation fuse 11. In the present application, the first circuit protection device can be at least one of a fuse, a thermal fuse, and an excitation fuse.

[0059] By connecting the first circuit protection device in series in the first reset branch, when a fault current appears in the electrical circuit for the second time or the current exceeds a set threshold, the first circuit protection device is disconnected, and the first reset branch that has been turned on disconnects the electrical circuit due to the action of the first circuit protection device being disconnected, thereby achieving protection of the electrical circuit.

[0060] Figure 2 The principle of the embodiment shown is integrated into a protection device module, which can be seen in Figure 8 As shown in the structural schematic diagram, the electrical circuit protection device may include a first excitation fuse 10, a first melt 30 connected to the connection end of the first excitation fuse 10, the first melt 30 is in a bent structure, a static contact point of a static contact 50 is arranged at one end of the first melt 30, and the first melt 30 also serves as a flexible structure 51 of the static contact 50. A moving contact 40 is arranged on the driving mechanism 60, and the moving contact 40 is driven by the driving mechanism 60 to move and contact with the static contact 50 in an electrically conductive manner. When the first melt 30 also serves as a flexible structure of the static contact, the end thereof in contact with the moving contact is preferably set to a convex shape as a static contact point 52 of the static contact. When the first melt 30 also serves as a static contact, the impact energy of the contact between the moving contact and the static contact can be reduced by the flexibility of the melt, so as to achieve the purpose of shock absorption, and the number of components can be saved, the utilization rate of the installation space can be improved, and the product volume can be miniaturized.

[0061] See also Figure 3 , Figure 3 In the illustrated embodiment, when the second excitation fuse 11 is connected in series in the first reset branch where the first mechanical switch 20 is located, the first reset branch is connected in parallel to both ends of the first excitation fuse, and the trigger signal of the second excitation fuse 11 can be sent by the trigger signal output terminal connected to the first excitation fuse 10. Only when the first mechanical switch 20 is closed can the second excitation fuse 11 receive the trigger signal.

[0062] Figure 3 The principle structure of the embodiment shown is the same as Figure 2 The principles of the embodiments shown are the same. In normal operation, the two ends of the first excitation fuse 10 are connected in series to the electrical circuit, the electrical circuit is turned on, and the first reset branch where the first mechanical switch 20 and the second excitation fuse 11 (or the first fuse 30) are located is disconnected.

[0063] When a fault current first appears in the electrical circuit or the current exceeds the set threshold, the control source is triggered to act, and the trigger signal output terminal sends a trigger signal to the first excitation fuse 10. Since the first mechanical switch 20 is disconnected, the second excitation fuse 11 cannot receive the trigger signal; the first excitation fuse 10 is actuated, the electrical circuit is disconnected for the first time, and the electrical circuit protection is realized. When the disconnected electrical circuit reaches the reset condition, the first mechanical switch 20 is closed according to the received external closing command, switching from normally open to normally closed, so that the first reset branch is turned on, and the electrical circuit is reset and turned on for the first time.

[0064] When a fault current appears in the electrical circuit for the second time or the current exceeds the set threshold, the first mechanical switch 20 is closed, the second excitation fuse 11 receives the trigger signal and is actuated, and the electrical circuit is disconnected for the second time; (when it is the first fuse 30, the first fuse 30 melts and disconnects the electrical circuit), thereby realizing electrical circuit protection.

[0065] Depend on Figure 3 The circuit protection device module formed by integrating the principle structure of the embodiment shown in FIG. Fig.11 and Fig.12 The structural schematic diagram shown includes a housing 100, which is composed of an upper and lower housing. The connection ends of the first excitation fuse 10 and the second excitation fuse 11 at the same end are conductively connected through a conductive connecting plate 102, and the conductive connecting plate 102 can be connected to the electrical circuit. A static contact 50 of the first mechanical switch 20 is respectively arranged on the connection ends of the other ends of the first excitation fuse 10 and the second excitation fuse 11, and the two static contacts 50 are insulated. The static contact 50 includes a flexible structure 51 and a static contact 52, and a static contact that is in conductive contact with the moving contact is arranged at one end of the flexible structure, so that the static contact becomes a soft-connection static contact. The static contact is connected to the connection ends of the first excitation fuse 10 and the second excitation fuse 11 through a conductive flexible structure, and one end provided with the static contact is used as a free end. The driving mechanism 60 of the first mechanical switch 20 is provided with a moving contact 40, and the moving contact 40, the static contact 50 and the driving mechanism 60 are the main components of the first mechanical switch 20. In the initial state and normal working state of the electrical circuit protection device, the moving contact 40 and the stationary contact 50 remain insulated, that is, the first mechanical switch 20 remains in the normally open state, and the first reset branch is in the disconnected state. When a fault current appears in the electrical circuit or the current exceeds the set threshold, the drive mechanism 60 receives an external closing command to drive the moving contact 40 to move and make conductive contact with the stationary contact 50, thereby making the first reset branch conductive. Since the stationary contact adopts a conductive flexible structure, when the moving contact contacts the stationary contact, the stationary contact with a flexible structure can buffer part of the impact energy of the moving contact, thereby achieving a shock-absorbing effect.

[0066] The contacts of the moving contact and the stationary contact of the first mechanical switch 20 can use silver alloy contacts, preferably silver tin oxide, to enhance the contact effect and reduce the contact resistance. The driving mechanism 60 is a permanent magnet mechanism, an electromagnetic mechanism or an excitation closing mechanism. When the driving mechanism 60 is a permanent magnet driving mechanism or an electromagnetic driving mechanism, the moving contact 40 is arranged on the driving mechanism 60, and an insulating partition 61 is arranged between the driving mechanism 60 and the moving contact 40. The insulating partition 61 separates the driving mechanism from the moving contact, that is, separates the driving mechanism from the electrical circuit that is turned on after the moving contact contacts the stationary contact. By setting the insulating partition 61, an independent secondary circuit compartment is formed in combination with the shell, which is physically insulated from the electrical circuit, thereby improving the insulation withstand voltage level, reducing the volume of the device, achieving miniaturization, and improving product reliability.

[0067] See also Figure 4 , Figure 4 FIG. 2 is a schematic diagram showing the principle structure of another embodiment of the electrical circuit protection device of the present invention. Figure 4 As shown, in Figure 3 Based on the embodiment structure of the electrical circuit protection device shown, a second mechanical switch 21 can be connected in parallel at both ends of the second excitation fuse 11 to form a second reset branch, and the first mechanical switch 20 and the second mechanical switch 21 are connected in series, and the first mechanical switch 20 is located between the first excitation fuse 10 and the second mechanical switch 21.

[0068] Under normal working conditions, the two ends of the first excitation fuse 10 are connected in series to the electrical circuit, the first mechanical switch 20 and the second mechanical switch 21 are both in a normally open state, and the first reset branch and the second reset branch are both in a disconnected state.

[0069] When a fault current first appears in the electrical circuit or the current exceeds the set threshold, the control source is triggered to act, and the trigger signal output terminal sends a trigger signal to the first excitation fuse 10. Since the first mechanical switch 20 is disconnected, the second excitation fuse 11 cannot receive the trigger signal; the first excitation fuse 10 acts according to the received trigger signal, cuts off the conductive plate, and the electrical circuit is disconnected for the first time, thereby realizing electrical circuit protection. When the disconnected electrical circuit reaches the reset condition, the first mechanical switch 20 is closed according to the received external closing command, switching from normally open to normally closed, so that the first reset branch is turned on, and the electrical circuit is reset and turned on for the first time.

[0070] When a fault current appears in the electrical circuit for the second time or the current exceeds the set threshold, the first mechanical switch 20 is closed, the second excitation fuse 11 receives the trigger signal and is activated, and the electrical circuit is disconnected for the second time, thereby realizing electrical circuit protection; when the disconnected electrical circuit reaches the reset condition again, the second mechanical switch 21 is closed according to the external closing command received, switching from normally open to normally closed, the second reset branch is turned on, and the electrical circuit is reset and turned on for the second time.

[0071] Figure 4 The principle of the embodiment shown is to realize two disconnection protections of the electrical circuit and reset the conduction after two disconnection protections through two excitation fuses (10, 11) and two mechanical switches (20, 21).

[0072] In some embodiments, Figure 4 Based on the principle, the second circuit protection device is connected in series on the second reset branch where the mechanical switch 21 is located, so that after the electrical circuit is reset and turned on for the second time, the electrical circuit protection device still has a safety protection function for the electrical circuit. That is, the second circuit protection device and the second mechanical switch 21 are connected in series to form a second reset branch, one end of the second circuit protection device is connected to the second mechanical switch 21, and the other end is conductively connected to the first excitation fuse 10 and one end of the first circuit protection device, and one end of the second mechanical switch 21 is conductively connected to one end of the second mechanical switch 20.

[0073] See also Figure 5 , Figure 6 In the embodiment shown, Figure 5 , Figure 6 In the embodiments of the electrical circuit protection device shown in FIG. Figure 4 The structure of the embodiment shown is based on Figure 4 In the embodiment shown, a second circuit protection device is connected in series with the mechanical switch (ie, the second mechanical switch): Figure 5 As shown in , the second circuit protection device may be a second fuse 31; for example Figure 6 As shown in , the second circuit protection device may be a third excitation fuse 12 . Figure 5 and Figure 6 According to the structural principle, after the electrical circuit is disconnected and reset twice, when a fault current occurs in the electrical circuit for the third time or the current exceeds the set threshold, the electrical circuit can be disconnected for the third time by the second circuit protection device to achieve electrical circuit protection.

[0074] Figure 5 and Figure 6 The working principle of the embodiment shown is the same. Figure 6 The illustrated embodiment is taken as an example, that is, the second circuit protection device is the third excitation fuse 12 as an example for explanation.

[0075] Figure 6 Working principle of the illustrated embodiment:

[0076] When the electrical circuit is in normal working condition, the two ends of the first excitation fuse 10 are connected to the electrical circuit in series, the first mechanical switch 20 and the second mechanical switch 21 are both in a normally open state, the first reset branch and the second reset branch are both in a disconnected state, and the first excitation fuse 10, the second excitation fuse 11, and the third excitation fuse 12 are all in a conducting state.

[0077] When a fault current first appears in the electrical circuit or the current exceeds the set threshold, the control source is triggered to act, and the trigger signal output terminal sends a trigger signal to the first excitation fuse 10. Since the first mechanical switch 20 is disconnected, the second excitation fuse 11 cannot receive the trigger signal; the first excitation fuse 10 acts according to the received trigger signal, cuts off the conductive plate, and the electrical circuit is disconnected for the first time, thereby realizing electrical circuit protection. When the disconnected electrical circuit reaches the reset condition, the first mechanical switch 20 is closed according to the received external closing command, switching from normally open to normally closed, so that the first reset branch is turned on, and the electrical circuit is reset and turned on for the first time.

[0078] When a fault current appears in the electrical circuit for the second time or the current exceeds the set threshold, the first mechanical switch 20 is closed, the second excitation fuse 11 receives the trigger signal and is activated, and the electrical circuit is disconnected for the second time, thereby realizing electrical circuit protection; when the disconnected electrical circuit reaches the reset condition again, the second mechanical switch 21 is closed according to the external closing command received, switching from normally open to normally closed, the second reset branch is turned on, and the electrical circuit is reset and turned on for the second time.

[0079] When a fault current appears in the electrical circuit for the third time or the current exceeds the set threshold, since the first mechanical switch 20 and the second mechanical switch 21 are both closed, the trigger signal output terminal will send a trigger signal to the third excitation fuse 12. The third excitation fuse 12 will be actuated according to the received trigger signal to cut off the conductive plate, and the electrical circuit will be disconnected for the third time, thereby realizing the third disconnection protection of the electrical circuit.

[0080] In actual use, according to customer needs, the first, second, third ... Nth reset branches can be designed, with a total of N reset branches. When there are N reset branches, mechanical switches and circuit protection devices are respectively connected in series on the 1st to N-1th reset branches. The Nth reset branch must be equipped with a mechanical switch, and whether to set a circuit protection device depends on the needs. In the initial state, in the electrical circuit protection device, the mechanical switches in all reset branches are in the normally open state. When each reset branch includes a circuit protection device, the initial state of the circuit protection devices in all reset branches is the on state. The specific structure is as follows: a first excitation fuse that can be connected in series to the electrical circuit, a first mechanical switch is connected in parallel to the first excitation fuse to form a first reset branch; a first circuit protection device is connected in series to the first reset branch, one end of the first circuit protection device is connected to the first mechanical switch, and the other end is connected to the end of the first excitation fuse that is not connected to the first mechanical switch; a second mechanical switch is connected in parallel to the first circuit protection device to form a second reset branch, in the second reset branch, a second circuit protection device is connected in series, one end of the second circuit protection device is connected to the second mechanical switch, and the other end is connected to the end of the first excitation fuse that is not connected to the first mechanical switch; a third mechanical switch is connected in parallel to the second circuit protection device to form a third reset branch, in the third reset branch, a third circuit protection device is connected in series, one end of the third circuit protection device is connected to the third mechanical switch, and the other end is connected to the end of the first excitation fuse that is not connected to the first mechanical switch; and so on, when N reset branches are provided, the Nth reset branch is connected in parallel to the N-1th circuit protection device on the N-1th reset branch. The Nth reset branch must include the Nth mechanical switch. The Nth reset branch may be provided with the Nth circuit protection device connected in series with the Nth mechanical switch, or may not be provided. When the Nth circuit protection device is provided, one end of the Nth circuit protection device is connected to one end of the Nth mechanical switch, and the other end is connected to the end of the first excitation fuse that is not connected to the first mechanical switch. Wherein, N is a natural number greater than or equal to 1. When the Nth reset branch is not provided with the Nth circuit protection device, N disconnections and N resets of the electrical circuit can be achieved. When the Nth reset branch is provided with the Nth circuit protection device, N+1 disconnections and N resets of the electrical circuit can be achieved. In the present application, the N reset branches from the first reset branch to the Nth reset branch are all in the disconnected state in the initial working state of the electrical circuit protection device. In a specific application, according to the position of each reset branch or the connection relationship in the circuit, the conduction of the two ends of the corresponding reset branch is achieved by closing the mechanical switches in each reset branch.

[0081] Figure 1 In the illustrated embodiment, N is 1, and the first reset branch is not connected in series with the first circuit protection device, so it can achieve one disconnection and one reset of the electrical circuit; Figure 2 and Figure 3In the illustrated embodiment, N is 1, and the first reset branch is connected in series with the first circuit protection device, which can achieve two disconnections and one reset of the electrical circuit.

[0082] Figure 4 In the illustrated embodiment, N is 2, and there are a first reset branch and a second reset branch. The first reset branch is connected in series with a first circuit protection device, and the second reset branch is not provided with a second circuit protection device. Then, it can realize two disconnections and two resets of the electrical circuit.

[0083] Figure 5 and Figure 6 In the illustrated embodiment, N is 2, and there are a first reset branch and a second reset branch. The first reset branch is connected in series with a first circuit protection device, and the second reset branch is connected in series with a second circuit protection device. This can achieve three disconnections and two resets of the electrical circuit.

[0084] Therefore, the design can be carried out according to the actual number of disconnections and resets of the electrical circuit, and the principle satisfies the above description.

[0085] The excitation fuse and the mechanical switch in the electrical circuit protection device of the present invention are integrated to form a modular structure. The two connection ends of the first excitation fuse are used as the electrical circuit access ends, and the other components are connected in sequence and finally connected to the two ends of the first excitation fuse, combined with the housing, to form a modular structure. When connecting and installing, only the two ends of the first excitation fuse need to be connected to the electrical circuit, which saves installation and connection time and reduces the product volume.

[0086] The mechanical switch of each of the above embodiments includes a drive mechanism 60 and a mechanical contact system, wherein the mechanical contact system includes a stationary contact 50 and a moving contact 40. The driving mechanism 60 drives the moving contact 40 to move and make conductive contact with the stationary contact 50, thereby closing the mechanical switch. Fig. 9As shown, two static contacts 50 are respectively arranged on a conductive connecting plate, where the conductive connecting plate can be the two ends of the disconnected circuit or the connection end of the excitation fuse connected to the mechanical switch, that is, the static contact is preferably arranged in the circuit using existing parts. The static contact 50 includes a flexible structure 51 and a static contact 52. The flexible structure 51 is U-shaped, and the static contact 52 is arranged on the free end of the flexible structure 51 to form a soft-connected static contact. The static contact is made of a silver alloy contact, preferably silver tin oxide. The driving mechanism 60 is a permanent magnet mechanism or an electromagnetic mechanism, and an insulating partition 61 is arranged on the driving mechanism 60, and a moving contact 40 is arranged on the insulating partition, and a moving contact corresponding to the static contact is arranged on the moving contact 40, and the material of the moving contact is a silver alloy contact, preferably silver tin oxide. The driving mechanism is separated from the moving contact and the electrical circuit by the insulating partition 61 to achieve physical insulation. The moving contact is connected to the moving iron core (not shown) of the driving mechanism through a connecting rod (not shown). The moving contact is driven by the driving mechanism 60 to move and make conductive contact with the stationary contact to close the mechanical switch.

[0087] When the driving mechanism of the mechanical switch in the electrical circuit protection device is an excitation closing mechanism, refer to Fig.10 As shown. The driving mechanism 60 is an excitation closing mechanism. The flexible structure of the static contact 50 is respectively arranged on the connecting ends on the same side of the first excitation fuse 10 and the second excitation fuse 11. The flexible structure of the static contact 50 is bent in a U shape, and a static contact is arranged on the free end of the static contact 50. The static contact is made of a silver alloy contact, preferably silver tin oxide. The moving contact 40 is arranged on the piston (not shown) of the excitation closing mechanism. The excitation source (i.e., the gas generating device) of the excitation closing mechanism is actuated according to the received trigger signal, and the driving force is released. The driving piston drives the moving contact 40 to move, and makes conductive contact with the static contact 50 to realize the closure of the mechanical switch.

[0088] One, part or all of the static contacts of the above-mentioned mechanical switches adopt static contacts of soft connection mode, which is specifically determined according to the components connecting the two ends of the mechanical switch.

[0089] In some other embodiments, the second reset branch, the third reset branch, the fourth reset branch, etc., each reset branch can be connected in parallel with the first excitation fuse, for example Fig.13 As shown in , the first reset branch and the second reset branch can be connected in parallel at both ends of the first excitation fuse, respectively, and the second reset branch includes a second mechanical switch; or, for example Fig.14 As shown in , the first reset branch and the second reset branch can be connected in parallel to the first excitation fuse, respectively, and the second reset branch includes a second mechanical switch and a second circuit protection device connected in series with the second mechanical switch. Fig.13 and Fig.14, taking the first reset branch 81 and the second reset branch 82 connected in parallel to the first excitation fuse 10 as an example, the first reset branch 81 must include the first mechanical switch 20 and the first circuit protection device 91 connected in series therewith in order to disconnect the electrical circuit again through the first circuit protection device 91 after the first reset branch 81 resets the electrical circuit. The second reset branch 82 must include the second mechanical switch 21. Whether to include the second circuit protection device 92 connected in series with the second mechanical switch 21 depends on the design requirements. When the second mechanical switch 21 resets the electrical circuit, it is no longer necessary to protect the electrical circuit, and the second circuit protection device does not need to be connected in series. When the second mechanical switch 21 resets the electrical circuit, it is necessary to protect the electrical circuit, and the second circuit protection device is connected in series in the second reset branch to achieve the desired effect.

[0090] If N reset branches are connected in parallel to the first excitation fuse 10, that is, the first reset branch, the second reset branch, the third reset branch, ... the N-1th reset branch, the Nth reset branch are connected in parallel; each reset branch from the first reset branch to the N-1th reset branch must include a mechanical switch and a circuit protection device connected in series therewith, and the Nth reset branch must include a mechanical switch. Whether to include a circuit protection device connected in series with the mechanical switch is determined according to actual needs. Its working principle and Figures 1 to 12 The principles of the embodiments shown are different. Figures 1 to 12 The principle of the illustrated embodiment is that the mechanical switches must be closed in sequence because the mechanical switches in different reset branches are connected in series; however Fig.13 and Fig.14 In the illustrated embodiment, the closing order of the mechanical switches of the reset branches does not affect each other, and the order is specified by the control end of the client.

[0091] Fig.15 , Fig.16 The structure of the embodiment shown can be Figure 6 On the basis of the structure of the embodiment shown, a third reset branch 83 is added to set, for example Fig.15 , 16 As shown in , a third reset branch 83 can be added on the basis of the first reset branch 81 and the second reset branch 82, wherein the third reset branch 83 includes a third mechanical switch 22, or includes a third mechanical switch 22 and a third circuit protection device connected in series with the third mechanical switch 22. Specifically, there are multiple ways to set the third reset branch 83 in the electrical circuit protection device:

[0092] See also Fig.15 , Fig.15In the illustrated embodiment, the third reset branch 83 is connected in parallel with the second reset branch 82 . The third reset branch 83 and the second reset branch 82 are respectively connected in parallel to two ends of the first circuit protection device 91 in the first reset branch 81 .

[0093] See also Fig.16 , Fig.16 In the illustrated embodiment, the first reset branch 81 and the third reset branch 83 are respectively connected in parallel at both ends of the first excitation fuse 10, and the second reset branch 82 (that is, a branch consisting of the second circuit protection device 92 and the second mechanical switch 21 connected in series) is connected in parallel at both ends of the first circuit protection device 91 in the first reset branch 81; specifically, Fig.16 The embodiment shown can be realized by Figure 6 On the basis of the illustrated embodiment, the third reset branch 83 is connected in parallel to both ends of the first excitation fuse 10 .

[0094] Fig.17 , Fig.18 The structure of the embodiment shown can be Fig.14 On the basis of the structure of the embodiment shown, a third reset branch 83 is added. Fig.17 , 18 As shown in , a third reset branch 83 can be added on the basis of the first reset branch 81 and the second reset branch 82, wherein the third reset branch 83 includes a third mechanical switch 22, or includes a third mechanical switch 22 and a third circuit protection device, wherein the third circuit protection device is connected in series with the third mechanical switch 22. Specifically, there are multiple ways to set the third reset branch 83 in the electrical circuit protection device:

[0095] See also Fig.17 ,exist Fig.17 In the embodiment of the electrical circuit protection device shown, the first reset branch 81 and the second reset branch 82 are respectively connected in parallel at both ends of the first excitation fuse 10, and the third reset branch 83 is connected in parallel at both ends of the second circuit protection device 92 in the second reset branch 82.

[0096] See also Fig.18 ,exist Fig.18 In the embodiment of the electrical circuit protection device shown, the first reset branch 81 , the second reset branch 82 , and the third reset branch 83 are respectively connected in parallel at both ends of the first excitation fuse 10 .

[0097] In the present application, in each embodiment, the first circuit protection device, the second circuit protection device, and the third circuit protection device can be at least one of an excitation fuse, a fuse, and a thermal fuse, respectively; and in the present application, in the initial state, the first circuit protection device, the second circuit protection device, and the third circuit protection device are respectively in the on state, and the first mechanical switch, the second mechanical switch, and the third mechanical switch are respectively in the normally open state in the initial state.

[0098] The electrical circuit protection device of the present invention can realize at least one disconnection and one reset of the electrical circuit, thereby reducing the number of times the electrical circuit protection device needs to be repaired and replaced, and reducing the use cost and maintenance cost.

Claims

1. An electrical circuit protection device, characterized in that: include: A first excitation fuse and a first mechanical switch, wherein the first excitation fuse can be connected in series to an electrical circuit, and the first mechanical switch is connected in parallel with the first excitation fuse to form a first reset branch; in an initial working state, the first excitation fuse is in a conducting state, and the first mechanical switch is in a normally open state; when a fault current appears in the electrical circuit for the first time or the current exceeds a threshold, the first excitation fuse is actuated according to the received trigger signal to disconnect the electrical circuit for the first time; when the electrical circuit reaches a reset condition, the first mechanical switch is closed according to the received closing instruction, so that the first reset branch is conductively connected to the electrical circuit, and the electrical circuit is reopened for the first time.

2. The electrical circuit protection device according to claim 1, characterized in that: The first reset branch also includes a first circuit protection device, which is connected in series with the first mechanical switch; in the initial working state, the first circuit protection device is in an on state; when a fault current appears in the electrical circuit for the second time or the current exceeds a threshold, the first electrical protection device is actuated to disconnect the first reset branch and disconnect the electrical circuit for the second time.

3. The electrical circuit protection device according to claim 2, characterized in that: A second mechanical switch is connected in parallel at both ends of the first excitation fuse or at both ends of the first circuit protection device to form a second reset branch; when the second mechanical switch is connected in parallel at both ends of the first circuit protection device, the second mechanical switch is connected in series with the first mechanical switch; in the initial working state, the second mechanical switch is in a normally open state; when the electrical circuit that is disconnected for the second time reaches the reset condition, the second mechanical switch is closed according to the received closing instruction, so that the second reset branch is conductively connected to the electrical circuit, and the electrical circuit is reopened for the second time.

4. The electrical circuit protection device according to claim 3, characterized in that: The second reset branch also includes a second circuit protection device, which is connected in series with the second mechanical switch, wherein one end of the second circuit protection device is connected to one end of the first circuit protection device, and the other end of the second circuit protection device is connected to the second mechanical switch; in an initial working state, the second circuit protection device is in an on state; when a fault current appears in the electrical circuit for the third time or the current exceeds a threshold, the second electrical protection device is actuated to disconnect the second reset branch, thereby disconnecting the electrical circuit for the third time.

5. The electrical circuit protection device according to claim 4, characterized in that: It also includes a third reset branch, wherein the third reset branch is a third mechanical switch connected in parallel at both ends of the first excitation fuse, or at both ends of the second reset branch, or at both ends of the second circuit protection device; when the second reset branch is connected in parallel to the first circuit protection device and the third mechanical switch is connected in parallel to both ends of the second reset branch, the third mechanical switch is connected in series with the first mechanical switch; when the third mechanical switch is connected in parallel to the second circuit protection device, the third mechanical switch is connected in series with the second mechanical switch; in the initial working state, the third mechanical switch is in a normally open state; when the electrical circuit that is disconnected for the third time reaches the reset condition, the third mechanical switch is closed according to the received closing instruction, so that the third reset branch is conductively connected to the electrical circuit, and the electrical circuit is reopened for the third time.

6. The electrical circuit protection device according to claim 5, characterized in that: The third reset branch also includes a third circuit protection device, which is connected in series with the third mechanical switch, wherein one end of the third circuit protection device is connected to one end of the second circuit protection device, and the other end of the third circuit protection device is connected to the third mechanical switch; in an initial working state, the third circuit protection device is in an on state; when a fault current appears in the electrical circuit for the fourth time or the current exceeds a threshold, the third electrical protection device is actuated to disconnect the third reset branch and disconnect the electrical circuit for the fourth time.

7. The electrical circuit protection device according to any one of claims 1 to 6, characterized in that: The first mechanical switch, the second mechanical switch and the third mechanical switch respectively include a driving mechanism and a mechanical contact system; the mechanical contact system includes a static contact and a moving contact; in the initial working state, the moving contact is insulated from the static contact; the driving mechanism acts according to the received closing instruction to drive the moving contact to make conductive contact with the static contact.

8. The electrical circuit protection device according to claim 7, characterized in that: The static contact is a soft-connection type static contact.

9. The electrical circuit protection device according to claim 7, characterized in that: The driving mechanism is a permanent magnet mechanism, an electromagnetic mechanism or an excitation closing mechanism; when it is a permanent magnet mechanism or an electromagnetic mechanism, the moving contact is driven to be in conductive contact with the static contact by the moving iron core of the permanent magnet mechanism or the electromagnetic mechanism; When it is an excitation closing mechanism, the excitation closing mechanism includes an excitation source and a piston. The excitation source acts according to the received closing instruction to release a driving force, and the driving force drives the piston, and the piston drives the moving contact to be in conductive contact with the static contact.

10. The electrical circuit protection device according to claim 9, characterized in that: When the driving mechanism is a permanent magnet mechanism or an electromagnetic mechanism, an insulating partition is provided between the driving mechanism and the moving contact.

11. The electrical circuit protection device according to any one of claims 1 to 6, characterized in that: It also includes a detection control module, wherein the detection output end of the detection control module is connected to the first excitation fuse signal receiving end; the detection control module detects the current signal of the electrical circuit by electromagnetic induction; When a fault current occurs in the electrical circuit or the current exceeds a threshold, the detection output terminal of the detection control module sends a trigger signal. According to the order in which the detection output terminal of the detection control module sends the trigger signal, the electrical circuit protection device performs one of the following actions: The first excitation fuse disconnects the electrical circuit for the first time according to the received trigger signal; or, The first circuit protection device disconnects the electrical circuit for a second time according to the received trigger signal; or, The second circuit protection device disconnects the electrical circuit for a third time according to the received trigger signal, or, The third circuit protection device disconnects the electrical circuit for a fourth time according to the received trigger signal.

12. The electrical circuit protection device according to any one of claims 1 to 6, characterized in that: The first circuit protection device, the second circuit protection device and the third circuit protection device are respectively at least one of a fuse, a thermal fuse and an excitation fuse.

13. The electrical circuit protection device according to claim 12, characterized in that: When at least one of the first circuit protection device, the second circuit protection device and the third circuit protection device is a fuse, the static contact on the static contact of the mechanical switch connected in series with the fuse is arranged on the fuse.

14. The electrical circuit protection device according to claim 12, characterized in that: When at least one of the first circuit protection device, the second circuit protection device and the third circuit protection device is an excitation fuse, a trigger signal of the circuit protection device set to be the excitation fuse and a common trigger signal of the first excitation fuse are provided, and an output end of the trigger signal is conductively connected to a signal receiving end of the first excitation fuse.

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