Excitation fuse with active and passive integrated protection function

Abstract

The invention relates to the field of electric vehicles and other electric power control, in particular to an excitation fuse with an active and passive integrated protection function, which comprises an excitation source, a passive control power supply circuit, an excitation action piece, a conductive piece and a magnetic trigger device in mechanical linkage with a switch arranged in series in the passive control power supply circuit, the magnetic triggering device is arranged on a magnetic field loop generated when the conductive piece is electrified; the switch in the normal working state is in a normally open state; the excitation source can receive a trigger signal sent by the passive control power supply circuit or sent by the outside of the excitation fuse; when the current of the conductive piece exceeds a threshold value, the magnetic trigger device drives the switch to be closed, and the excitation source receives a trigger signal sent by the passive control power supply circuit to act; and the excitation action piece is driven to disconnect the conductive loop of the conductive piece. The protection is more reliable, the protection range is large, the action time is short, the loop resistance is low, the temperature rise power consumption performance is good, the size is small, and the structure is simple and reliable.

Description

Technical Field

[0001] The present invention relates to the field of circuit protection and circuit protection of new energy vehicles, specifically to protective electrical appliances in the field of new energy direct current distribution, and in particular to an excitation fuse with active and passive integrated protection functions. Background Art

[0002] Existing excitation fuses, especially those used in new energy fields such as electric vehicles, are mainly based on active protection, that is, when the control system (BMS) detects abnormal conditions such as a short circuit in the main circuit and needs to cut off the circuit, the control system needs to provide a trigger signal to the trigger device of the excitation fuse, and the excitation fuse can cut off the circuit. In other words, the excitation fuse is an actuator, and the realization of its protection function is completely dependent on the control system. It cannot cut off the circuit by itself by sensing large currents. The applicant has developed a high-reliability active and passive integrated protection device as disclosed in Chinese Patent 2022215716777. The protection device is a passive excitation protection device. The product adds a passive protection function on the basis that the original excitation fuse can accept active control of the system. The basic principle is that a signal fuse is connected in series on the main circuit (conductive plate of the excitation fuse). When the current in the main circuit is too large, the signal fuse can be passively blown. The voltage signal at both ends of the signal fuse blown port is connected to the excitation source, thereby triggering the excitation source to act and completing the circuit cutoff. This product has active and passive integrated protection functions, but it also has certain disadvantages: because the signal fuse is connected in series in the main circuit, the signal fuse needs to ensure normal current carrying and current shock resistance, and it must also blow when abnormal current occurs. Therefore, the lower limit value of its short-circuit protection is relatively high, and the action time is relatively long, which cannot meet the requirements of some systems. At the same time, because of the series connection of the signal fuse, the resistance value of the entire main circuit is increased compared to the ordinary excitation fuse, and the temperature rise power consumption becomes worse. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an excitation fuse with active and passive integrated protection functions. Without changing the main circuit structure of the excitation fuse, a magnetic trigger device is used to control the passive control power supply circuit to send a trigger signal to the excitation source, thereby keeping the main circuit resistance value and power consumption unchanged.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is an excitation fuse with active and passive integrated protection functions, including an excitation source, an excitation action member, a conductive member, a passive control power supply circuit, and a magnetic trigger device;

[0005] The excitation source is conductively connected to the passive control power circuit, and the excitation source can receive a trigger signal sent by the passive control power circuit or a trigger signal sent from outside the excitation fuse;

[0006] A switch is provided in series in the passive control power supply circuit, and in a normal working state, the switch is in a normally open state;

[0007] The magnetic trigger device is arranged on the magnetic field loop generated when the conductive member is energized, and the magnetic trigger device is made of magnetic conductive material; when the current flowing through the conductive member exceeds a set threshold, the magnetic trigger device is triggered and at least a part of the magnetic trigger device can be displaced under the action of the magnetic field force generated when the conductive member is energized;

[0008] The magnetic trigger device is mechanically linked to the switch; when the current flowing through the conductive member exceeds a set threshold, the magnetic trigger device is triggered and drives the switch to close, so that the passive control power supply circuit is turned on and a trigger signal is sent to the excitation source;

[0009] The excitation source is actuated according to the received trigger signal, releases the driving force, and drives the excitation action member to disconnect the conductive loop where the conductive member is located.

[0010] Preferably, the magnetic trigger device includes a dynamic magnet and a static magnet, and the static magnet or the dynamic magnet is arranged around the conductive part. When the switch is in a normally open state, an air gap is arranged between the dynamic magnet and the static magnet; the dynamic magnet is mechanically linked to the switch; when the current flowing through the conductive part exceeds a threshold value, the dynamic magnet moves toward the static magnet to drive the switch to close.

[0011] Preferably, the number of the passive control power circuits is at least one group; when the number of the passive control power circuits is more than two groups, the number of the magnetic trigger devices is at least one group and is less than or equal to the number of the passive control power circuits; when the number of the magnetic trigger devices is equal to the number of the passive control power circuits, each group of the magnetic trigger devices can be mechanically linked with the switches in each group of the passive control power circuits in a one-to-one correspondence; when the number of the magnetic trigger devices is less than the number of the passive control power circuits, the switches in each group of the passive control power circuits are mechanically linked with the magnetic trigger devices of the same group, or the switches in some groups of the passive control power circuits are mechanically linked with the magnetic trigger devices of the same group.

[0012] Preferably, the moving magnet is displaced toward the static magnet in a rotational manner or a translational manner.

[0013] Preferably, the initial position of the moving magnet is limited by a limiting member.

[0014] Preferably, the limiting member is a spring, one end of the limiting member is connected to the moving magnet, and the other end of the limiting member is fixedly arranged.

[0015] Preferably, the static magnet or the dynamic magnet is a semi-enclosed structure, and the conductive member passes through a recess in the semi-enclosed structure; the other of the dynamic magnet and the static magnet is arranged near the end of the semi-enclosed structure having the recess; in the initial state of the magnetic trigger device, the dynamic magnet and the static magnet are arranged at an angle or in parallel to each other, so that an air gap is formed between the dynamic magnet and the static magnet.

[0016] Preferably, the static magnet is a U-shaped structure or a C-shaped structure, the conductive member passes through a groove of the U-shaped structure or the C-shaped structure, and the dynamic magnet is arranged at an open end of the U-shaped structure or the C-shaped structure of the static magnet; in the initial state of the magnetic trigger device, the dynamic magnet is arranged at an angle or in parallel with the open end of the U-shaped structure or the C-shaped structure.

[0017] Preferably, the switch is a switch sheet structure or a micro switch, wherein the switch sheet structure includes a static switch sheet and a dynamic switch sheet; the dynamic magnet is mechanically linked to the dynamic switch sheet, or the dynamic magnet is mechanically linked to a driving rod of the micro switch; when the current flowing through the conductive member exceeds a threshold value, the dynamic magnet is displaced toward the static magnet and drives the dynamic switch sheet to displace toward the static switch sheet or drives the driving rod of the micro switch to displace toward the closing direction of the micro switch, so that the switch is closed.

[0018] Preferably, a capacitor is provided in the passive control power supply circuit, and the capacitor is provided in parallel with the power supply in the passive control power supply circuit.

[0019] Preferably, a diode is provided between the capacitor and the power supply in the passive control power supply circuit, and the diode blocks the capacitor from discharging to the power supply.

[0020] Preferably, an arc-extinguishing fuse is connected in parallel to the conductive member.

[0021] Preferably, it includes a first shell and a second shell; the excitation source, the excitation action member, and the arc-extinguishing fuse are respectively arranged in the first shell, the conductive member is arranged through the first shell, and both ends of the conductive member are located outside the first shell; the magnetic trigger device and the switch of the passive control power supply circuit are arranged in the second shell, and the second shell is located at the conductive member outside the first shell.

[0022] Preferably, the excitation source operates according to the received trigger signal to drive the excitation action member to disconnect the conductive member.

[0023] The excitation fuse of the present invention integrates a passive control power supply circuit and a magnetic trigger device in the excitation fuse on the basis that the excitation fuse can be controlled by an external control system and actively sends a trigger signal to an excitation source. The magnetic trigger device controls the passive control power supply circuit to send a trigger signal to the excitation source, thereby realizing passive excitation, that is, passive excitation, and realizing active and passive integrated protection.

[0024] The magnetic trigger device is activated by magnetic induction, and there is no need to connect a signal fuse in series with the conductive plate (main circuit) of the excitation fuse, so the resistance value of the main circuit and the power consumption due to temperature rise can be kept unchanged.

[0025] The trigger signal is sent by the magnetic trigger device, which has a larger breaking current range and faster response speed than connecting the signal fuse in series in the main circuit.

[0026] Compared with the existing passively excited excitation fuse, the main circuit resistance is lower, the temperature rise power consumption performance is better, and the structure is simple, compact and smaller in size.

[0027] The excitation fuse of the active and passive integrated protection arrangement of the present invention improves the breaking capacity and breaking reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the principle of the excitation fuse for passive protection.

[0029] Figure 2 yes Figure 1 Schematic diagram of the principle of adding capacitance.

[0030] Figure 3 It is a schematic diagram of the principle of the excitation fuse for active and passive protection.

[0031] Figure 4 yes Figure 3 Schematic diagram of the principle of adding capacitance.

[0032] Figure 5 It is a cross-sectional structural schematic diagram and a partial cross-sectional view of one embodiment of the excitation fuse of the present invention when it is not triggered, wherein Figure E is the AA cross-sectional view of Figure F.

[0033] Figure 6 yes Figure 5 Schematic diagram of the structure after triggering, where Figure G is the AA cross-sectional view of Figure H.

[0034] Figure 7 It is a structural diagram of the second embodiment.

[0035] Figure 8 yes Figure 7 Schematic diagram of the appearance structure.

[0036] Excitation source 1, excitation action part 2, conductive part 3, disconnect weak point 31, arc extinguishing fuse 4, passive control power supply circuit 5, capacitor 51, diode 52, power supply 10, switch 6, fixed switch piece 61, moving switch piece 62, drive rod 63, magnetic trigger device 7, static magnet 71, moving magnet 72, support spring 73, guide column 74, active control power supply circuit 8, circuit board 9, first shell 100, second shell 101, third shell 102. DETAILED DESCRIPTION

[0037] The excitation fuse with active and passive integrated protection function of the present invention is characterized in that it includes an excitation source, an excitation action member, a conductive member, a passive control power circuit, and a magnetic trigger device; the excitation source is conductively connected to the passive control power circuit, and the excitation source can receive a trigger signal sent by the passive control power circuit or a trigger signal sent from the outside of the excitation fuse; a switch is provided in series in the passive control power circuit, and under normal working conditions, the switch is in a normally open state;

[0038] The magnetic trigger device is arranged on the magnetic field loop generated when the conductive part is energized, and is made of magnetic conductive material; when the current flowing through the conductive part exceeds a set threshold, the magnetic trigger device is triggered and at least a part of the magnetic trigger device can be displaced under the action of the magnetic field force generated when the conductive part is energized;

[0039] The magnetic trigger device is mechanically linked to the switch; when the current flowing through the conductive part exceeds the set threshold, the magnetic trigger device is triggered and drives the switch to close, turning on the passive control power supply circuit and sending a trigger signal to the excitation source; the excitation source acts according to the received trigger signal, releases the driving force, and drives the excitation action member to disconnect the conductive circuit where the conductive part is located.

[0040] The excitation source in the present invention is a gas generating device, which is ignited by receiving a trigger signal to release high-pressure gas as a driving force.

[0041] The excitation source, the excitation action part, the conductive part, the arc-extinguishing fuse and the structural positional relationship therebetween are all technical solutions for the existing excitation fuse. Therefore, in the following embodiments, the excitation source, the excitation action part, the conductive part, the arc-extinguishing fuse and the structural positional relationship therebetween are not described in detail. As long as the excitation fuse includes the excitation source (a device that releases the driving force under the action of a trigger signal), the excitation action part (a component that can be moved under the driving force and can disconnect the conductive part), and the conductive part (a conductive structure that can be connected to the circuit, such as a conductive plate), the requirements can be met.

[0042] The technical solution of the present invention is described in detail below with reference to preferred embodiments and accompanying drawings.

[0043] See also Figure 1, which is a schematic diagram of the principle structure of the excitation fuse of the present invention, includes an excitation source 1, an excitation action member 2, a conductive member 3, and an arc-extinguishing fuse 4. The excitation action member 2 is arranged corresponding to the disconnection weak point 31 of the conductive member 3, and the arc-extinguishing fuse 4 is connected in parallel at both ends of the disconnection weak point 31 of the conductive member 3. The arc-extinguishing fuse 4 is located on the displacement path after the excitation action member 2 disconnects the conductive member.

[0044] The excitation source 1 is actuated according to the received trigger signal, and can release the driving force to drive the excitation action member 2 to move, thereby successively cutting off the disconnection weak point 31 of the conductive member 3 and the arc-extinguishing fuse 4, disconnecting the main circuit, and the arc-extinguishing fuse 4 is used to extinguish the arc.

[0045] The passive control power supply circuit 5 is integrated in the excitation fuse. The passive control power supply circuit 5 is connected to the signal receiving end of the excitation source 1 to form a trigger circuit. A connection end connected to the power supply 10 is left on the passive control power supply circuit 5. When the excitation fuse is used, the passive control power supply circuit 5 is connected to the power supply through the connection end to form a complete trigger circuit, and a trigger signal is sent to the excitation source 1 through the passive control power supply circuit 5.

[0046] A switch 6 is connected in series in the passive control power supply circuit 5 . Under normal working conditions, the switch 6 is normally open, and the passive control power supply circuit 5 is in a non-conducting state, and cannot send a trigger signal to the excitation source 1 .

[0047] The magnetic trigger device 7 is arranged around the conductive member 3, and is arranged on the magnetic field loop generated when the conductive member 3 is energized. Under normal working conditions, the magnetic trigger device 7 retains an air gap. The magnetic trigger device 7 is arranged at a position that does not affect the excitation action member 2 to disconnect the conductive member 3 and the arc-extinguishing fuse 4.

[0048] Magnetic trigger device 7, see Figure 1, including a static magnet 71 and a dynamic magnet 72. The static magnet 71 is arranged around the conductive member 3. One end of the dynamic magnet 72 is located at one side of the switch 6 and is mechanically linked to the switch 6. The other end is arranged adjacent to the static magnet 71. Under normal working conditions, an air gap is arranged between the static magnet 71 and the dynamic magnet 72. When current flows through the conductive member 3, a magnetic field is generated around the conductive member 3. The static magnet is arranged around the conductive member 3 for magnetization, so that the static magnet has a certain magnetic field. When the current is larger, the magnetic field transmitted to the static magnet is stronger. When the current flowing through the conductive member 3 exceeds a certain value, the current value is the set threshold value, that is, the minimum overload current value. Since there is an air gap between the static magnet 71 and the dynamic magnet 72, the magnetic field of the static magnet 71 acting on the dynamic magnet 72 can drive the dynamic magnet 72 to move toward the static magnet 71, that is, the dynamic magnet moves toward the static magnet in the direction of closing the air gap and is adsorbed on the static magnet 71. As the dynamic magnet 72 moves, the dynamic magnet 72 drives the switch 6 to close, so that the passive control power supply circuit 5 is turned on and a trigger signal is sent to the excitation source 1.

[0049] Figure 1 In the embodiment, the static magnet 71 of the magnetic trigger device 7 is arranged around the conductive member 3, which does not change the structure of the conductive member 3. Therefore, the magnetic trigger device 7 does not change the resistance value of the conductive member (ie, the main circuit) and does not increase the power consumption due to temperature rise.

[0050] By setting the magnetic trigger device 72, the passive control power supply circuit 5 is controlled to be closed, thereby controlling the sending of the trigger signal. When the current flowing through the conductive part 3 exceeds the set threshold, the magnetic trigger device responds and controls the passive control power supply circuit 5 to send a trigger signal, and the excitation source 1 acts according to the trigger signal received from the conductive part, drives the excitation action part 2 to move, cuts off the conductive part 3 and the arc extinguishing fuse 4 in turn, and disconnects the main circuit to achieve passive protection. Therefore, the excitation fuse of the present invention has a fast response speed, a lower main circuit resistance than the existing passive excitation fuse, and low power consumption due to temperature rise.

[0051] Figure 1 Passive protection is achieved by controlling the passive control power circuit 5 to close and send a trigger signal through the magnetic trigger device. However, when any one of the magnetic trigger device, the passive control power circuit 5, and the power supply 10 fails, the trigger signal cannot be sent to the excitation source, resulting in a major safety accident in which the excitation fuse cannot be disconnected. In order to improve the disconnection reliability of the excitation fuse, refer to Figure 2, an active control power circuit 8 can also be connected to the signal receiving end of the excitation source 1, and an external trigger signal is sent to the excitation source through the active control power circuit 8. The active control power circuit 8 is controlled by the control system of the client, and in the case of overload or abnormal conditions (such as a collision accident of a new energy vehicle, or under certain specific conditions), it actively sends a trigger signal to the excitation source 1 to form active protection. The active control power circuit 8 is a circuit outside the excitation fuse, belongs to the client, and is not integrated in the excitation fuse of the present invention. When in use, the signal receiving end of the excitation source of the excitation fuse of the present invention can be connected to the external active control power circuit 8 to achieve active protection.

[0052] In order to prevent the power supply 10 of the passive control power supply circuit 5 from failing to work, see Figure 3 and Figure 4 A capacitor 51 is connected in parallel at both ends of the positive and negative electrodes of the power supply 10 of the passive control power supply circuit 5, so that the capacitor 51 and the power supply 10 are connected in parallel, and the capacitor 51 is used as a backup of the power supply 10. A diode 52 is provided between the connection line between the capacitor 51 and the power supply 10, and the function of the diode 52 is to prevent the capacitor 51 from discharging to the power supply 10.

[0053] Function of capacitor 51: When the current of conductive member 3 exceeds the set threshold value, i.e., the overload current, the passive control power circuit 5 is turned on, but the power supply 10 suddenly fails and cannot work, then capacitor 51 discharges to provide power to the passive control power circuit 5, so that it sends a trigger signal to the excitation source 1. Capacitor 51 serves as a backup for the power supply 10, and improves the working reliability of the passive control power circuit 5.

[0054] See also Figure 5 and Figure 6 , is a schematic diagram of a specific structure of one embodiment of the excitation fuse of the present invention. The excitation source 1 and the excitation action member 2 are sequentially arranged on the same side of the conductive member 3, and a disconnection weak point 31 is arranged on the conductive member 3. The disconnection weak point 31 is a part for reducing the mechanical strength, and the excitation action member 2 is arranged opposite to the disconnection weak point 31 of the conductive member 3.

[0055] The trigger signal receiving end of the excitation source 5 is connected to the circuit board 9, and the passive control power supply circuit 5 is integrated on the circuit board 9. The switch 6 is conductively arranged on the circuit board 9, and is a switch sheet structure, including a fixed switch sheet 61 and a movable switch sheet 62. The movable switch sheet 62 can be displaced to conductively contact with the fixed switch sheet to close the switch 6. Sufficient gaps are reserved between the fixed switch sheet 61 and the movable switch sheet 62 and the circuit board 9.

[0056] A groove is provided at one end of the static magnet 71, and the groove passes through both sides of the static magnet 71. The conductive member 3 passes through the groove of the static magnet 71, so that the static magnet 71 surrounds the outer periphery of the conductive member 3, and the conductive member 3 does not contact the static magnet 71. One end of the opening of the groove of the static magnet 71 faces the circuit board 9. When the groove is provided on the static magnet 71, the static magnet 71 can be a semi-enclosed structure such as a U-shaped structure and a C-shaped structure.

[0057] The moving magnet 72 is similar to an inverted T-shaped structure. The end close to the static magnet 71 is set at an angle with the end of the static magnet 71 with a groove, so that an air gap is formed between the static magnet 71 and the moving magnet 72. The end close to the circuit board 9 is penetrated on the guide column 74, and one side of the end penetrated on the guide column 74 is located on the side of the moving switch sheet 62. A support spring 73 is set as a limiter on the side where the angle between the moving magnet 72 and the static magnet 71 is the largest. One end of the support spring 73 is connected to the moving magnet 72, and the other end is fixedly connected to the excitation fuse housing to support the initial position of the moving magnet 72 and keep it in a stable state. The other end of the support spring 73 can also be fixedly connected to the static magnet 71. When the current on the conductive member 3 exceeds the set threshold, the magnetic field of the static magnet 71 drives the dynamic magnet 72 to move in the direction of the static magnet 71 in a rotating manner. The dynamic magnet 72 overcomes the elastic force of the support spring 73 and is finally adsorbed on the static magnet 71. During the movement of the dynamic magnet 72, the dynamic magnet 72 presses the dynamic switch piece 62 to move and make conductive contact with the fixed switch piece 61, so that the switch 6 is closed and the passive control power supply circuit is turned on; the support spring 73 is compressed and in a compressed state. The limiter for defining the initial position of the dynamic magnet 72 can also be a spring, one end of which is fixedly set on the excitation fuse housing or the static magnet 71, and the other end is suspended to form a support for the dynamic magnet 72. When the dynamic magnet 72 is attracted by the static magnet, the dynamic magnet 82 overcomes the supporting force of the spring and is attracted to the static magnet 71.

[0058] In this embodiment, the dynamic conductive magnet contacts the static conductive magnet in a rotational manner or in a translational manner. When in translational contact with the static conductive magnet, the dynamic conductive magnet and the static conductive magnet are arranged parallel to each other at adjacent ends.

[0059] The support spring 73 and the guide column 74 are all arranged on the first housing 100. The excitation source, the excitation action member, the conductive member, the magnetic trigger device, and the circuit board 9 are all arranged on the housing. Figure 5 and Figure 6 Only part of it is shown.

[0060] Figure 5 Before triggering, there is an air gap between the dynamic magnet and the static magnet, and the dynamic switch piece and the static switch piece of the switch are not in contact; Figure 6After being triggered, the moving magnet is adsorbed on the static magnet, and the moving switch piece and the static switch piece of the switch are in conductive contact.

[0061] See also Figure 7 and Figure 8 , is another specific structural embodiment of the present invention. It includes a second shell 101, and a third shell 102 is arranged next to the second shell. An excitation source 1, an excitation action member 2, and a conductive member 3 are arranged in the second shell 101 and pass through the second shell 101 and the third shell 102. The arc extinguishing fuse is arranged in parallel on the conductive member 3 in the second shell 101, and the circuit board 9 is arranged in the second shell 101. The conductive member 3 located in the third shell 102 is arranged around the static conductive magnet 71, and the dynamic conductive magnet 72 is arranged on one end side of the static conductive magnet 71. An air gap is arranged between the dynamic conductive magnet and the static conductive magnet. The structural relationship between the dynamic and static conductive magnets can be referred to. Figure 5 The switch 6 is arranged in the third housing, the switch 6 is a micro switch, and the moving magnet 72 is located on one side of the driving rod 63 outside the micro switch. The connecting line of the micro switch passes through the third housing and the second housing and is connected to the circuit board 9.

[0062] Figure 7 The operating principle is the same as Figure 5 The principle of action.

[0063] In the above embodiment, one passive control power supply circuit 5 and one group of magnetic trigger devices are provided. In other embodiments, multiple passive control power supply circuits 5 and one group of magnetic trigger devices may be provided, or when multiple passive control power supply circuits 5 are provided, each passive control power supply circuit 5 is provided with one group of magnetic trigger devices; or when multiple passive control power supply circuits 5 are provided, the number of magnetic trigger devices is greater than one group and less than the number of passive control power supply circuits 5. When one group of magnetic trigger devices is provided corresponding to multiple passive control power supply circuits 5, the switches of the magnetic trigger devices and the multiple passive control power supply circuits 5 are mechanically linked. When provided one-to-one, one group of magnetic trigger devices is mechanically linked with the switches of one passive control power supply circuit 5.

[0064] Compared with the current excitation fuse, the excitation fuse of the present invention has both active protection and passive protection functions, and the protection functions are more complete and reliable; the protection range is larger, and the action time is faster (especially in the case of a low-multiple short circuit); the loop resistance is lower, and the temperature rise power consumption performance is better; the volume is smaller, and the structure is simpler and more reliable.

Claims

1. An excitation fuse with active and passive integrated protection functions, characterized in that: include: Excitation source, excitation action part, conductive part, passive control power circuit, magnetic trigger device; The excitation source is conductively connected to the passive control power circuit, and the excitation source can receive a trigger signal sent by the passive control power circuit or a trigger signal sent from outside the excitation fuse; A switch is arranged in series in the passive control power supply circuit, and in a normal working state, the switch is in a normally open state; the magnetic trigger device is arranged on the magnetic field loop generated when the conductive member is energized, and the magnetic trigger device is made of a magnetic conductive material; when the current flowing through the conductive member exceeds a set threshold, the magnetic trigger device is triggered and causes at least a part of the magnetic trigger device to be displaced under the action of the magnetic field force generated when the conductive member is energized; The magnetic trigger device is mechanically linked to the switch; when the current flowing through the conductive member exceeds a set threshold, the magnetic trigger device is triggered and drives the switch to close, so that the passive control power supply circuit is turned on and a trigger signal is sent to the excitation source; The excitation source is actuated according to the received trigger signal, releases the driving force, and drives the excitation action member to disconnect the conductive loop where the conductive member is located.

2. The excitation fuse according to claim 1, characterized in that: The magnetic trigger device includes a dynamic magnet and a static magnet. The static magnet or the dynamic magnet is arranged around the conductive member. When the switch is in a normally open state, an air gap is arranged between the dynamic magnet and the static magnet. The dynamic magnet is mechanically linked to the switch. When the current flowing through the conductive member exceeds a threshold value, the dynamic magnet moves toward the static magnet to drive the switch to close.

3. The excitation fuse according to claim 1 or 2, characterized in that: The number of the passive control power circuits is at least one group; when the number of the passive control power circuits is more than two groups, the number of the magnetic trigger devices is at least one group and is less than or equal to the number of the passive control power circuits; when the number of the magnetic trigger devices is equal to the number of the passive control power circuits, each group of the magnetic trigger devices can be mechanically linked with the switches in each group of the passive control power circuits in a one-to-one correspondence; when the number of the magnetic trigger devices is less than the number of the passive control power circuits, the switches in each group of the passive control power circuits are mechanically linked with the magnetic trigger devices of the same group, or the switches in some groups of the passive control power circuits are mechanically linked with the magnetic trigger devices of the same group.

4. The excitation fuse according to claim 2, characterized in that: The moving magnet is displaced toward the static magnet in a rotational manner or a translational manner.

5. The excitation fuse according to claim 2, characterized in that: The initial position of the moving magnet is limited by a limiting member.

6. The excitation fuse according to claim 5, characterized in that: The limiting member is a spring, one end of the limiting member is connected to the moving magnet, and the other end of the limiting member is fixedly arranged.

7. The excitation fuse according to claim 2, characterized in that: The static magnet or the dynamic magnet is a semi-enclosed structure, and the conductive member passes through a recess in the semi-enclosed structure; the other of the dynamic magnet and the static magnet is arranged near an end of the semi-enclosed structure having the recess; in the initial state of the magnetic trigger device, the dynamic magnet and the static magnet are arranged at an angle or in parallel, so that an air gap is formed between the dynamic magnet and the static magnet.

8. The excitation fuse according to claim 7, characterized in that: The static magnet is a U-shaped structure or a C-shaped structure, the conductive member passes through a groove of the U-shaped structure or the C-shaped structure, and the dynamic magnet is arranged at an open end of the U-shaped structure or the C-shaped structure of the static magnet; in the initial state of the magnetic trigger device, the dynamic magnet is arranged at an angle or in parallel with the open end of the U-shaped structure or the C-shaped structure.

9. The excitation fuse according to claim 2, characterized in that: The switch is a switch sheet structure or a micro switch, wherein the switch sheet structure includes a static switch sheet and a dynamic switch sheet; the dynamic magnet is mechanically linked with the dynamic switch sheet, or the dynamic magnet is mechanically linked with a driving rod of the micro switch; when the current flowing through the conductive member exceeds a threshold value, the dynamic magnet is displaced toward the static magnet and drives the dynamic switch sheet to displace toward the static switch sheet or drives the driving rod of the micro switch to displace toward the closing direction of the micro switch, so that the switch is closed.

10. The excitation fuse according to claim 1, characterized in that: A capacitor is provided in the passive control power supply circuit, and the capacitor is provided in parallel with the power supply in the passive control power supply circuit.

11. The excitation fuse according to claim 10, characterized in that: A diode is provided between the capacitor and a power supply in the passive control power supply circuit, and the diode blocks the capacitor from discharging to the power supply.

12. The excitation fuse according to any one of claims 1 to 2 and 4 to 11, characterized in that: An arc-extinguishing fuse is connected in parallel to the conductive member.

13. The excitation fuse according to claim 12, characterized in that: It includes a first shell and a second shell; the excitation source, the excitation action member, and the arc-extinguishing fuse are respectively arranged in the first shell, the conductive member is arranged through the first shell, and the two ends of the conductive member are located outside the first shell; the magnetic trigger device and the switch of the passive control power supply circuit are arranged in the second shell, and the second shell is located at the conductive member outside the first shell.

14. The excitation fuse according to claim 1, characterized in that: The excitation source is actuated according to the received trigger signal to drive the excitation action member to disconnect the conductive member.

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