Shut-off system and shut-off method

Abstract

A shutoff system (1) comprises: an active fuse (13) that is provided in a power path (30) that connects a battery (10) with a load (11) and is for shutting off a power path (30); a current sensor (12) that detects a current flowing through the power path (30); a control unit (14); a reversible switch (20) that is provided on a voltage detection wiring (16) that connects the control unit (14) with a node between a positive-side terminal of the battery (10) and a positive-side terminal of the load (11) in the power path (30). The control unit (14) determines whether the detected current indicates an abnormal state. When it is determined that the detected current indicates the abnormal state, the control unit (14) transmits an opening instruction signal for opening the reversible switch (20) to the reversible switch (20), and transmits a shut-off instruction signal for shutting off the power path (30) to the active fuse (13).

Description

Isolation system and isolation method

[0001] The present disclosure relates to an interruption system for interrupting an electric power line.

[0002] Patent Document 1 discloses a system that detects the voltage of a power line and cuts off the power line using a relay switch if the detected voltage is abnormal.

[0003] Japanese Patent Application Laid-Open No. 2021-180545

[0004] In recent years, active fuses capable of quickly interrupting power lines have been installed in systems such as those disclosed in Patent Document 1. When an active fuse interrupts a power line, a large back electromotive force is generated in the power line. This back electromotive force may be applied to a control unit (hereinafter referred to as a control unit) via wiring for detecting the voltage of the power line. If such a large back electromotive force is applied to the control unit, a voltage exceeding the rated voltage may be applied to components included in the control unit, destroying these components and potentially causing the control unit to catch fire or emit smoke.

[0005] Therefore, the present disclosure provides an interruption system and the like that can protect a control unit from a back electromotive force generated in a power line.

[0006] The interruption system of the present disclosure comprises an active fuse provided in a power path connecting a battery and a load for interrupting the power path, a current sensor for detecting a current flowing in the power path, a control unit, and a reversible switch provided in a voltage detection wiring connecting a node in the power path between the positive terminal of the battery and the positive terminal of the load and the control unit, wherein the control unit determines whether the detected current indicates an abnormal state, and if it determines that the detected current indicates an abnormal state, it sends an open instruction signal to the reversible switch to open the reversible switch, and sends a cut-off instruction signal to the active fuse to cut off the power path.

[0007] The interruption method according to the present disclosure is a method for an interruption system, the interruption system being provided in a power path connecting a battery and a load and including an active fuse for interrupting the power path, a current sensor for detecting a current flowing in the power path, and a reversible switch provided in a voltage detection wiring connecting a node in the power path between the positive terminal of the battery and the positive terminal of the load and a control unit, the interruption method determining whether the detected current indicates an abnormal state, and if it is determined that the detected current indicates an abnormal state, transmitting an open instruction signal to the reversible switch to open the reversible switch, and transmitting a cutoff instruction signal to the active fuse to cut off the power path.

[0008] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0009] According to an aspect of the present disclosure, the interruption system can protect the control unit from the back electromotive force generated in the power line.

[0010] FIG. 1 is a block diagram showing an example of an isolation system according to an embodiment. FIG. 2 is a flowchart showing an example of an operation of the isolation system according to an embodiment. FIG. 3 is a timing chart showing a first example of an operation of the isolation system according to an embodiment. FIG. 4 is a timing chart showing a second example of an operation of the isolation system according to an embodiment. FIG. 5 is a timing chart showing a third example of an operation of the isolation system according to an embodiment. FIG. 6 is a block diagram showing an example of an isolation system according to a first modified example of an embodiment. FIG. 7 is a block diagram showing an example of an isolation system according to a second modified example of an embodiment. FIG. 8 is a block diagram showing an example of an isolation system according to a third modified example of an embodiment. FIG. 9 is a block diagram showing an example of an isolation system according to a fourth modified example of an embodiment.

[0011] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0012] The embodiments described below are all comprehensive or specific examples, and the numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0013] (Embodiment) Hereinafter, an interruption system according to an embodiment will be described.

[0014] Fig. 1 is a block diagram showing an example of an interruption system 1 according to an embodiment. The interruption system 1 is used in transportation equipment or the like including a battery 10 and a load 11. Fig. 1 also shows the battery 10 and the load 11 provided in the transportation equipment or the like in addition to the interruption system 1. The interruption system 1 is used in an electric vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a fuel cell vehicle (FCV) as the transportation equipment, for example.

[0015] The battery 10 is a battery capable of applying a high voltage of, for example, several hundred volts to the load 11. For example, the battery 10 is a main battery (for example, a lithium ion battery) in an electric vehicle.

[0016] The load 11 is, for example, a motor, inverter, or converter of an electric vehicle. Power is supplied from the battery 10 to the load 11, a motor drive signal is generated in the load 11, and the motor is driven by the signal, thereby providing propulsion power for the electric vehicle. In the event of an accident or the like, a large current may flow due to a short circuit in the power path 30 connecting the battery 10 and the load 11, which may cause the battery 10 and the load 11 to emit smoke or catch fire, and therefore the interruption system 1 is used in transportation equipment.

[0017] The interruption system 1 is a system for interrupting an electric power path 30 in the event of an abnormality, and includes terminals A, B, C, and D. Terminal A is connected to the positive terminal of a battery 10, terminal B is connected to the negative terminal of the battery 10, terminal C is connected to the positive terminal of a load 11, and terminal D is connected to the negative terminal of the load 11. Note that, in this example, both the path connecting the positive terminal of the battery 10 and the positive terminal of the load 11 (in other words, the path connecting terminals A and C) and the path connecting the negative terminal of the battery 10 and the negative terminal of the load 11 (in other words, the path connecting terminals B and D) are part of the electric power path 30. The interruption system 1 includes an active fuse 13 that is interrupted by a signal from outside the active fuse 13 (e.g., the control unit 14 in FIG. 1 ), a current sensor 12, a control unit 14, and a reversible switch 20. Note that, for example, the active fuse 13 is a pyro-fuse, a pyro-switch, or a pyrotechnic interruption device. Furthermore, this embodiment does not deny the use of an active switch as the active fuse 13.

[0018] The active fuse 13 is a device provided in the power path 30 connecting the battery 10 and the load 11 for interrupting the power path 30. For example, the active fuse 13 is provided between the positive terminal of the battery 10 and the positive terminal of the load 11 in the power path 30. The active fuse 13 interrupts the power path 30 when a large current flows through the power path 30 due to a short circuit abnormality. A pyro-fuse, pyro-switch, or pyrotechnic interrupting device used as the active fuse 13 contains explosives and ignites the explosives based on an interruption command signal from outside the active fuse 13, thereby interrupting the power path 30 with the explosive force generated by the ignition of the explosives. The active fuse 13 interrupts the power path 30 upon receiving an interruption command signal from the control unit 14 via the interruption wiring 40.

[0019] The current sensor 12 is a sensor that detects the current flowing through the power path 30. For example, the current sensor 12 is a shunt-type sensor (e.g., a shunt resistor) or a sensor such as a Hall element. The current sensor 12 outputs the detection result (e.g., a current value (analog value)) to the control unit 14 via the current detection wiring 18.

[0020] The current sensor 12 is provided on the power path 30 between the positive terminal of the battery 10 and the positive terminal of the load 11, or between the negative terminal of the battery 10 and the negative terminal of the load 11. If the current sensor 12 is provided on the power path 30 between the positive terminal of the battery 10 and the positive terminal of the load 11 (in other words, on the path connecting terminals A and C), a high voltage may be applied between the current sensor 12 and the reference potential of the control unit 14 (also called a sensing board), to which the detection result of the current sensor 12 is output. This is because the reference potential of the control unit 14 is often set to the potential of the negative terminal of the battery 10. As shown in FIG. 1 , a grounding wire 15 for grounding the control unit 14 is connected to a node on the power path 30 between the negative terminal of the battery 10 and the current sensor 12. However, if the current sensor 12 is a non-contact type sensor such as a Hall element, even if the current sensor 12 is provided between the positive terminal of the battery 10 and the positive terminal of the load 11 in the power path 30, a high voltage is not applied to the current sensor 12 itself, and the control unit 14 is not affected, so this does not pose a problem. On the other hand, if the current sensor 12 is a shunt type sensor, a high voltage is applied to the current sensor 12, and the control unit 14 connected to the shunt resistor is also affected. For this reason, the current sensor 12 is provided between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30 (in other words, on the path connecting terminals B and D), as shown in FIG.

[0021] The control unit 14 is formed by, for example, a substrate also called a sensing board as described above. For example, the control unit 14 has a detection IC realized by a microcomputer (MCU: Micro Controller Unit) or the like, and the detection IC is mounted on the substrate.

[0022] The reversible switch 20 is provided on the voltage detection wiring 16 that connects the control unit 14 to a node on the power path 30 between the positive terminal of the battery 10 and the positive terminal of the load 11 (in other words, a node on the path connecting terminals A and C). For example, the reversible switch 20 is provided on the voltage detection wiring 16 that connects the control unit 14 to a node on the power path 30 between the active fuse 13 and the positive terminal of the load 11.

[0023] The reversible switch 20 is a semiconductor switch such as a field effect transistor (FET) or a bipolar transistor. For example, the reversible switch 20 may be a relay switch, but in this case, the response speed of the reversible switch 20 is slow and the reversible switch 20 is large. Therefore, using a semiconductor switch improves the response speed and reduces the size of the reversible switch 20. The gate or base of the reversible switch 20 is connected to the control unit 14 via a control wiring 41, and the control unit 14 controls the connection and disconnection (on and off) of the reversible switch 20. When the reversible switch 20 is in a connected state (on state), the control unit 14 is electrically connected to the power path 30 via the voltage detection wiring 16, and can acquire the voltage of the power path 30 (specifically, the voltage applied to the load 11). When the reversible switch 20 is in an open state (off state), the voltage detection wiring 16 is interrupted, and the control unit 14 is electrically disconnected from the power path 30.

[0024] Although not shown, providing a ladder resistor in the voltage detection wiring 16 can prevent a large current from flowing from the power path 30 to the control unit 14. The ladder resistor may be provided on the substrate of the control unit 14. Also, a portion of the voltage detection wiring 16 may be provided as a wiring pattern on the substrate of the control unit 14, or the reversible switch 20 may be mounted on the substrate of the control unit 14 and integrated with the control unit 14.

[0025] The control unit 14 determines whether the current detected by the current sensor 12, acquired via the current detection wiring 18, indicates an abnormal state. If the control unit 14 determines that the detected current indicates an abnormal state, it transmits a cutoff instruction signal to the active fuse 13 via the cutoff wiring 40 to cut off the power path 30.

[0026] The control unit 14 can also determine that the detected current indicates an abnormal state when the magnitude of the detected current exceeds a predetermined value. However, in this case, it may take some time for the magnitude of the current to exceed the predetermined value. Therefore, the control unit 14 may also determine that the detected current indicates an abnormal state when the change in the detected current per unit time exceeds a predetermined threshold. Because the current tends to increase rapidly in a short period of time when the current is in an abnormal state, monitoring the change in the detected current per unit time makes it possible to quickly determine whether the current is in an abnormal state. This prevents a large current from continuing to flow through the power path 30 for a long period of time before the active fuse 13 interrupts the power path 30, thereby preventing damage to components within the interruption system 1.

[0027] As described above, when the active fuse 13 interrupts the power path 30, a large back electromotive force is generated in the power path 30. For example, the parasitic inductance component of the path connecting the active fuse 13 and the positive terminal of the load 11 in the power path 30 and the inductance component of the load 11 attempt to continue flowing the current that was flowing in the power path 30 before the active fuse 13 interrupted the power path 30, generating a back electromotive force as shown in FIG. 1 . This back electromotive force is a large voltage, such as 1600 V, and may be applied to the control unit 14 via the voltage detection wiring 16. If such a large back electromotive force is applied to the control unit 14, a voltage exceeding the rated voltage will be applied to the components and ladder resistors included in the control unit 14, destroying these components and potentially causing the control unit 14 to catch fire or emit smoke. Therefore, the interruption system 1 includes a reversible switch 20 provided in the voltage detection wiring 16. Furthermore, since the ladder resistor is provided, the voltage applied to the reversible switch 20 is reduced by resistive voltage division, so the reversible switch 20 does not need to have a voltage resistance performance that can withstand a voltage corresponding to a back electromotive force, such as 1600 V.

[0028] Here, the operation of the control unit 14 will be described in detail with reference to FIG.

[0029] FIG. 2 is a flowchart showing an example of the operation of the shutdown system 1 (specifically, the control unit 14) according to the embodiment.

[0030] First, the control unit 14 determines whether the detected current indicates an abnormal state (step S11). If the control unit 14 determines that the detected current does not indicate an abnormal state (No in step S11), it ends the process and repeats the process from step S11.

[0031] When the control unit 14 determines that the detected current indicates an abnormal state (Yes in step S11), it transmits an open instruction signal to the reversible switch 20 to open the reversible switch 20, and transmits a cutoff instruction signal to the active fuse 13 to cut off the power path 30 (step S12). For example, the control unit 14 simultaneously transmits the open instruction signal and the cutoff instruction signal. When the current flowing through the power path 30 indicates an abnormal state, the control unit 14 needs to transmit the cutoff instruction signal to the active fuse 13 as quickly as possible after determining that the current flowing through the power path 30 indicates an abnormal state in order to prevent smoke or fire from occurring in the battery 10 and the load 11. On the other hand, in order to protect the control unit 14 from a back electromotive force generated in the power path 30 due to the cutoff of the power path 30, the control unit 14 needs to transmit the open instruction signal to the reversible switch 20 as quickly as possible after determining that the current flowing through the power path 30 indicates an abnormal state. Therefore, by transmitting both the open instruction signal and the cut-off instruction signal at the fastest possible simultaneous timing, it is possible to protect the control unit 14 from the back electromotive force generated in the power path 30 while suppressing smoke or fire from the battery 10 and the load 11.

[0032] After transmitting the open instruction signal and the cutoff instruction signal, the control unit 14 determines whether the detected current indicates a predetermined state (step S13). For example, the predetermined state may be a safe state in which the current is 0 A. That is, the control unit 14 determines whether current is still flowing through the power path 30 after the power path 30 is cut off. If the control unit 14 determines that the detected current does not indicate the predetermined state (No in step S13), the control unit 14 may end the processing and notify the user that current is flowing through the power path 30 even though the power path 30 has been cut off by the active fuse 13.

[0033] If the control unit 14 determines that the detected current indicates a predetermined state (Yes in step S13), it transmits a connection instruction signal to the reversible switch 20 to switch the reversible switch 20 into a connected state (step S14). For example, there is a desire to monitor the state of the load 11 even after the active fuse 13 interrupts the power path 30. Therefore, after the active fuse 13 interrupts the power path 30 and the reversible switch 20 is set to an open state, if the current flowing through the power path 30 is in a predetermined state, the reversible switch 20 is set to a connected state. This makes it possible to monitor the voltage applied to the load 11 even after the active fuse 13 interrupts the power path 30, thereby enabling diagnosis of the state of the load 11 or determination of an abnormality.

[0034] In cases where there is no desire to monitor the state of the load 11 even after the active fuse 13 has cut off the power path 30, the control unit 14 does not need to send a connection instruction signal to the reversible switch 20 even if it determines that the detected current indicates a predetermined state.

[0035] Depending on the specifications of the reversible switch 20 and the active fuse 13, the time until the reversible switch 20 actually enters the open state after the transmission of the open instruction signal and the transmission of the cut-off instruction signal may be shorter or longer than the time until the active fuse 13 cuts off the power path 30. For example, the time until the reversible switch 20 actually enters the open state varies depending on the input capacitance and input resistance of the reversible switch 20, the response performance of the reversible switch 20, the magnitude of the current input to the base of the reversible switch 20 (bipolar transistor) or the magnitude of the voltage input to the gate of the reversible switch 20 (FET), etc.

[0036] A case where the time required for the reversible switch 20 to be opened is shorter than the time required for the active fuse 13 to cut off the power path 30 will be described with reference to FIG.

[0037] FIG. 3 is a timing chart showing a first example of the operation of the shutdown system 1 according to the embodiment.

[0038] As shown in FIG. 3 , after an abnormality occurs in the current flowing through the power path 30, it takes a time indicated by i for the control unit 14 to determine that the current is in an abnormal state. After the control unit 14 determines that the current is in an abnormal state, it takes a time indicated by ii for the control unit 14 to transmit an open instruction signal and a shutoff instruction signal. The times indicated by i and ii correspond to the processing speed of a detection IC such as a microcomputer. After the control unit 14 transmits the open instruction signal, it takes a time indicated by iii for the reversible switch 20 to become completely open. The time indicated by iii corresponds to the specifications of the reversible switch 20. After the reversible switch 20 becomes open, it takes a time indicated by iv for the active fuse 13 to shut off the power path 30. The time indicated by iii + iv corresponds to the specifications of the active fuse 13. When the active fuse 13 shuts off the power path 30, the current flowing through the power path 30 becomes zero. In the first example, the reversible switch 20 is in an open state before the active fuse 13 shuts off the power path 30.

[0039] After the current flowing through the power path 30 becomes zero, it takes the time indicated by v for the control unit 14 to determine that the current is not abnormal (i.e., the magnitude of the current is zero). After the control unit 14 determines that the current is not abnormal, it takes the time indicated by vi for the control unit 14 to stop transmitting the open instruction signal and the cut-off instruction signal. The time indicated by vi depends on the processing speed of a detection IC such as a microcomputer. After the control unit 14 stops transmitting the open instruction signal and the cut-off instruction signal, it takes the time indicated by vii for the reversible switch 20 to enter a connected state. The time indicated by vii depends on the specifications of the reversible switch 20. Note that once the active fuse 13 cuts off the power path 30, it cannot return to its pre-cut state.

[0040] In this way, in the first example, the control unit 14 sends an open instruction signal and a cut-off instruction signal, so that the reversible switch 20 first goes into an open state, and then the active fuse 13 cuts off the power path 30 .

[0041] A case where the time until the reversible switch 20 is opened is the same as the time until the active fuse 13 cuts off the power path 30 will be described with reference to FIG.

[0042] FIG. 4 is a timing chart showing a second example of the operation of the shutdown system 1 according to the embodiment.

[0043] As shown in FIG. 4 , after an abnormality occurs in the current flowing through the power path 30, it takes a time indicated by i for the control unit 14 to determine that the current is in an abnormal state. After the control unit 14 determines that the current is in an abnormal state, it takes a time indicated by ii for the control unit 14 to transmit an open instruction signal and a cut-off instruction signal. The times indicated by i and ii correspond to the processing speed of a detection IC such as a microcomputer. After the control unit 14 transmits the open instruction signal and the cut-off instruction signal, it takes a time indicated by iii for the reversible switch 20 to be completely open and for the active fuse 13 to cut off the power path 30. The time indicated by iii corresponds to the specifications of the active fuse 13 and the reversible switch 20. When the active fuse 13 cuts off the power path 30, the current flowing through the power path 30 becomes zero. In the second example, the reversible switch 20 is open at the same time that the active fuse 13 cuts off the power path 30.

[0044] After the current flowing through the power path 30 becomes zero, it takes the time indicated by iv for the control unit 14 to determine that the current is not in an abnormal state (i.e., the magnitude of the current is zero). After the control unit 14 determines that the current is not in an abnormal state, it takes the time indicated by v for the control unit 14 to stop transmitting the open instruction signal and the cut-off instruction signal. The time indicated by v depends on the processing speed of a detection IC such as a microcomputer. After the control unit 14 stops transmitting the open instruction signal and the cut-off instruction signal, it takes the time indicated by vi for the reversible switch 20 to enter a connected state. The time indicated by vi depends on the specifications of the reversible switch 20.

[0045] In this way, in the second example, the control unit 14 transmits an open instruction signal and a cut-off instruction signal, which causes the reversible switch 20 to be in an open state, and at the same time, the active fuse 13 cuts off the power path 30 .

[0046] A case where the time required for the reversible switch 20 to be opened is longer than the time required for the active fuse 13 to cut off the power path 30 will be described with reference to FIG.

[0047] FIG. 5 is a timing chart showing a third example of the operation of the shutdown system 1 according to the embodiment.

[0048] As shown in FIG. 5 , after an abnormality occurs in the current flowing through the power path 30, it takes a time indicated by i for the control unit 14 to determine that the current is in an abnormal state. After the control unit 14 determines that the current is in an abnormal state, it takes a time indicated by ii for the control unit 14 to transmit an open instruction signal and a cut-off instruction signal. The times indicated by i and ii correspond to the processing speed of a detection IC such as a microcomputer. After the control unit 14 transmits the open instruction signal and the cut-off instruction signal, it takes a time indicated by iii for the active fuse 13 to cut off the power path 30. The time indicated by iii corresponds to the specifications of the active fuse 13. When the active fuse 13 cuts off the power path 30, the current flowing through the power path 30 becomes zero. After the active fuse 13 cuts off the power path 30, it takes a time indicated by iv for the reversible switch 20 to be completely open. The time indicated by iii + iv corresponds to the specifications of the reversible switch 20. In the third example, the reversible switch 20 is in an open state after the active fuse 13 interrupts the power path 30 .

[0049] After the current flowing through the power path 30 becomes zero, it takes the time indicated by v for the control unit 14 to determine that the current is not in an abnormal state (i.e., the magnitude of the current is zero). After the control unit 14 determines that the current is not in an abnormal state, it takes the time indicated by vi for the control unit 14 to stop transmitting the open instruction signal and the cut-off instruction signal. The time indicated by vi is a time that depends on the processing speed of a detection IC such as a microcomputer. After the control unit 14 stops transmitting the open instruction signal and the cut-off instruction signal, it takes the time indicated by vii for the reversible switch 20 to enter a connected state. The time indicated by vii is a time that depends on the specifications of the reversible switch 20.

[0050] In this way, in the third example, the control unit 14 transmits an open instruction signal and a cut-off instruction signal, so that the active fuse 13 first cuts off the power path 30, and then the reversible switch 20 is opened. Even in this case, the time during which the back electromotive force generated in the power path 30 is applied to the control unit 14 can be reduced, and therefore the control unit 14 can be protected from the back electromotive force generated in the power path 30.

[0051] As described above, when the power path 30 is interrupted by the active fuse 13, the reversible switch 20 provided in the voltage detection wiring 16 connecting the power path 30 and the control unit 14 is opened, thereby preventing electrical continuity between the power path 30 and the control unit 14. Therefore, the back electromotive force generated when the power path 30 is interrupted by the active fuse 13 can be prevented from being applied to the control unit 14, and the control unit 14 can be protected from the back electromotive force generated in the power path 30.

[0052] (Modification 1) For example, the interruption system may include two reversible switches, which will be described with reference to FIG.

[0053] FIG. 6 is a block diagram illustrating an example of an interruption system 2 according to the first modification of the embodiment.

[0054] The interruption system 2 differs from the interruption system 1 in that it further includes a reversible switch 21. Since the other points are the same as those in the interruption system 1, the following description will focus on the differences.

[0055] One of the two reversible switches, reversible switch 21, is provided on voltage detection wiring 17 that connects the control unit 14 to a node in the power path 30 between the positive terminal of the battery 10 and the active fuse 13. The other of the two reversible switches, reversible switch 20, is provided on voltage detection wiring 16 that connects the control unit 14 to a node in the power path 30 between the active fuse 13 and the positive terminal of the load 11, as in the interruption system 1.

[0056] Like the reversible switch 20, the reversible switch 21 is a semiconductor switch. The gate or base of the reversible switch 21 is connected to the control unit 14 via a control wire 42, and the control unit 14 controls the connection and opening (on and off) of the reversible switch 21. When the reversible switch 21 is in a connected state (on state), the control unit 14 is electrically connected to the power path 30 via the voltage detection wire 17, and can acquire the voltage of the power path 30 (specifically, the voltage of the battery 10). When the reversible switch 21 is in an open state (off state), the voltage detection wire 17 is cut off, and the control unit 14 is not electrically connected to the power path 30.

[0057] Although not shown, by providing a ladder resistor in voltage detection wiring 17, it is possible to prevent a large current from flowing from power path 30 to control unit 14. The ladder resistor may be provided on the substrate of control unit 14. Also, a part of voltage detection wiring 17 may be provided as a wiring pattern on the substrate of control unit 14, and reversible switch 21 may be mounted on the substrate of control unit 14.

[0058] When the control unit 14 determines that the detected current indicates an abnormal state, it transmits an open instruction signal to the reversible switch 20 to put the reversible switch 20 into an open state, an open instruction signal to the reversible switch 21 to put the reversible switch 21 into an open state, and a cut-off instruction signal to the active fuse 13 to cause the active fuse 13 to cut off the power path 30. For example, the control unit 14 transmits each of the open instruction signal and the cut-off instruction signal simultaneously.

[0059] In the path connecting the positive terminal of battery 10 and the positive terminal of load 11 in power path 30, when active fuse 13 interrupts power path 30, there is a risk of back electromotive force being generated between the positive terminal of battery 10 and active fuse 13 in power path 30, and between active fuse 13 and the positive terminal of load 11 in power path 30. Therefore, by providing reversible switches 20 and 21 in voltage detection wiring 16 and 17 corresponding to these two locations, it is possible to prevent the back electromotive force generated at these two locations from being applied to control unit 14.

[0060] After transmitting each open instruction signal and each disconnect instruction signal, the control unit 14 determines whether the detected current indicates a predetermined state. If it determines that the detected current indicates a predetermined state, the control unit 14 transmits a connection instruction signal to the reversible switch 20 to set the reversible switch 20 to a connected state, and transmits a connection instruction signal to the reversible switch 21 to set the reversible switch 21 to a connected state. For example, the control unit 14 may simultaneously transmit the connection instruction signal to the reversible switch 20 and the connection instruction signal to the reversible switch 21. There is a demand for monitoring the status of the battery 10 or the load 11 even after the active fuse 13 interrupts the power path 30. Therefore, after the active fuse 13 interrupts the power path 30 and the reversible switches 20 and 21 are set to an open state, if the current flowing through the power path 30 is in a predetermined state, the reversible switches 20 and 21 are set to a connected state. This allows the voltage of the battery 10 or the voltage applied to the load 11 to be monitored even after the active fuse 13 interrupts the power path 30, enabling status diagnosis or abnormality detection.

[0061] In cases where there is no desire to monitor the status of the battery 10 or the load 11 even after the active fuse 13 has cut off the power path 30, the control unit 14 does not need to send a connection instruction signal to the reversible switches 20 and 21 even if it determines that the detected current indicates a predetermined state.

[0062] (Modification 2) For example, the active fuse 13 may be provided between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30. This case will be described with reference to FIG.

[0063] FIG. 7 is a block diagram showing an example of an interruption system 3 according to the second modification of the embodiment.

[0064] The interruption system 3 differs from the interruption system 1 in that the active fuse 13 is not provided between the positive terminal of the battery 10 and the positive terminal of the load 11 in the power path 30, but is provided between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30. The other points are the same as those in the interruption system 1, and therefore a description thereof will be omitted.

[0065] 7 , the active fuse 13 may be provided between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30. For example, the active fuse 13 may be provided between the current sensor 12 and the negative terminal of the load 11 in the power path 30.

[0066] Even if the active fuse 13 is provided between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30, a back electromotive force may be generated in the path connecting the positive terminal of the battery 10 and the positive terminal of the load 11 in the power path 30, so the technology disclosed herein can be applied.

[0067] (Modification 3) For example, the grounding line 15 may be connected to a node in the power path 30 between the current sensor 12 and the negative terminal of the load 11. This case will be described with reference to FIG.

[0068] FIG. 8 is a block diagram showing an example of an interruption system 4 according to the third modification of the embodiment.

[0069] The interruption system 4 differs from the interruption system 1 in that the grounding wire 15 is not connected to a node in the power path 30 between the negative terminal of the battery 10 and the current sensor 12, but is connected to a node in the power path 30 between the current sensor 12 and the negative terminal of the load 11. The other points are the same as those in the interruption system 1, and therefore a description thereof will be omitted.

[0070] For example, if the current sensor 12 is a non-contact sensor such as a Hall element, the potential between the negative terminal of the battery 10 and the current sensor 12 in the power path 30 and the potential between the current sensor 12 and the negative terminal of the load 11 will be the same, so as shown in Figure 8, the grounding wire 15 may be connected to the node between the current sensor 12 and the negative terminal of the load 11 in the power path 30.

[0071] For example, if current sensor 12 is configured as a shunt resistor, current sensor 12 is provided between the negative terminal of battery 10 and the negative terminal of load 11 on power path 30, i.e., at a location where the voltage is low on power path 30. In this case, as shown in Fig. 8 , when grounding wire 15 is connected to a node on power path 30 between current sensor 12 and the negative terminal of load 11, the reference potential of control unit 14 is affected by a voltage drop due to current sensor 12 (shunt resistor). Therefore, if control unit 14 is designed taking into consideration the effect of this voltage drop, grounding wire 15 may be connected to a node on power path 30 between current sensor 12 and the negative terminal of load 11, as shown in Fig. 8 .

[0072] In addition, as in the interruption system 1, by connecting the grounding wiring 15 to a node between the negative terminal of the battery 10 and the current sensor 12 in the power path 30, the reference potential of the control unit 14 can be prevented from being affected by the voltage drop caused by the current sensor 12.

[0073] In the interruption system 2 according to the first modification of the embodiment, the grounding wire 15 may also be connected to a node in the power path 30 between the current sensor 12 and the negative terminal of the load 11. In the interruption system 3 according to the second modification of the embodiment, the grounding wire 15 may also be connected to a node in the power path 30 between the current sensor 12 and the active fuse 13.

[0074] (Variation 4) For example, the grounding wire 15 may be connected to a current sensor 12 (shunt resistor) provided between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30. This case will be described with reference to FIG.

[0075] FIG. 9 is a block diagram illustrating an example of an interruption system 5 according to the fourth modification of the embodiment.

[0076] The interruption system 5 differs from the interruption system 1 in that the grounding wire 15 is not connected to a node between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30, but is connected to a current sensor 12 (shunt resistor) provided between the negative terminal of the battery 10 and the negative terminal of the load 11 in the power path 30. The other points are the same as those in the interruption system 1, and therefore a description thereof will be omitted.

[0077] As shown in FIG. 9, the grounding wiring 15 may be connected to a point in the current sensor 12 (shunt resistor) that is connected to the power path 30 (for example, a terminal in the shunt resistor that is connected to the power path 30).

[0078] In addition, in the interruption system 2 or 3 according to the first or second modified embodiment, the grounding wiring 15 may also be connected to the point of the current sensor 12 (shunt resistor) that is connected to the power path 30.

[0079] (Other Embodiments) As described above, the embodiments have been described as examples of the technology according to the present disclosure. However, the technology according to the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. For example, the following modifications are also included in one embodiment of the present disclosure.

[0080] For example, in the above embodiment, the control unit 14 transmits the open instruction signal and the cut-off instruction signal simultaneously, but this is not limiting. For example, the timings at which the control unit 14 transmits the open instruction signal and the cut-off instruction signal do not have to be completely synchronized, and may be slightly different.

[0081] For example, when there are multiple voltage detection wires, the interruption system may include n reversible switches (n is an integer greater than or equal to 1), and the n reversible switches may be provided on m (m is an integer greater than or equal to 1 and less than or equal to n) voltage detection wires among the multiple voltage detection wires that have a large inductance at the point where they are connected to the power path 30.

[0082] For example, in the interruption system 2 according to the first modification of the embodiment, two reversible switches 20 and 21 do not need to be provided, and a reversible switch may be provided in only one of the voltage detection wires 16 and 17. If the inductance at the point where the voltage detection wire 16 is connected to the power path 30 (specifically, the parasitic inductance component of the path connecting the active fuse 13 and the positive terminal of the load 11 and the inductance component of the load 11) is greater than the inductance at the point where the voltage detection wire 17 is connected to the power path 30 (specifically, the parasitic inductance component of the path connecting the positive terminal of the battery 10 and the active fuse 13 and the inductance component of the battery 10), the reversible switch 20 may be provided only in the voltage detection wire 16. Furthermore, if the inductance at the point where the voltage detection wire 17 is connected to the power path 30 is greater than the inductance at the point where the voltage detection wire 16 is connected to the power path 30, the reversible switch 21 may be provided only in the voltage detection wire 17.

[0083] In addition, there may be three or more voltage detection wirings, and a reversible switch may be provided for each of the three or more voltage detection wirings, or a reversible switch may not be provided for a voltage detection wiring connected to a location in the power path 30 where the inductance is low.

[0084] In this way, when there are multiple voltage detection wires, it is not necessary to provide a reversible switch for each of the multiple voltage detection wires, and reversible switches may be provided preferentially for voltage detection wires connected to locations in the power path 30 where inductance is high, i.e., locations where large back electromotive force is likely to occur.

[0085] For example, the present disclosure can be realized not only as an interruption system, but also as an interruption method including steps (processing) performed by components (e.g., the control unit 14) that make up the interruption system.

[0086] The interruption method is a method for an interruption system, the interruption system being provided in a power path 30 connecting a battery 10 and a load 11 and including an active fuse 13 for interrupting the power path 30, a current sensor 12 for detecting a current flowing through the power path 30, and a reversible switch provided in a voltage detection wiring connecting a node on the power path 30 between the positive terminal of the battery 10 and the positive terminal of the load 11 and a control unit 14, and as shown in FIG. 2 , the interruption method determines whether the detected current indicates an abnormal state (step S11), and if it is determined that the detected current indicates an abnormal state (Yes in step S11), transmits an open instruction signal to the reversible switch to open the reversible switch, and transmits a shutoff instruction signal to the active fuse 13 to shut off the power path 30 (step S12).

[0087] For example, the present disclosure can be realized as a program for causing a computer (processor) to execute steps included in the blocking method. Furthermore, the present disclosure can be realized as a non-transitory computer-readable recording medium, such as a CD-ROM, on which the program is recorded.

[0088] For example, when the present disclosure is realized as a program (software), each step is performed by running the program using hardware resources such as a computer's CPU, memory, input / output circuits, etc. In other words, each step is performed by the CPU acquiring data from memory or input / output circuits, etc., performing calculations, and outputting the calculation results to memory or input / output circuits, etc.

[0089] In the above-described embodiment, each component included in the shutdown system may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0090] Some or all of the functions of the shutdown system according to the above-described embodiments are typically realized as an LSI, which is an integrated circuit. These may be individually implemented as single chips, or may be integrated into a single chip that includes some or all of the functions. Furthermore, the integrated circuit is not limited to an LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within an LSI, may also be used.

[0091] Furthermore, if an integrated circuit technology that can replace LSIs emerges due to advances in semiconductor technology or other derivative technologies, that technology may naturally be used to integrate each component included in the shutdown system.

[0092] In addition, this disclosure also includes forms obtained by making various modifications to the embodiments that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions in each embodiment within the scope of the present disclosure.

[0093] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0094] (Technology 1) An interruption system comprising: an active fuse provided in an electric power path connecting a battery and a load, for interrupting the electric power path; a current sensor for detecting a current flowing in the electric power path; a control unit; and a reversible switch provided in a voltage detection wiring connecting the control unit to a node in the electric power path between the positive terminal of the battery and the positive terminal of the load, wherein the control unit determines whether the detected current indicates an abnormal state, and if it determines that the detected current indicates an abnormal state, transmits an open instruction signal to the reversible switch to open the reversible switch, and transmits a cutoff instruction signal to the active fuse to cut off the electric power path.

[0095] According to this, when the power path is interrupted by the active fuse, a reversible switch provided in the voltage detection wiring connecting the power path and the control unit is opened, thereby preventing electrical continuity between the power path and the control unit. Therefore, the back electromotive force generated when the power path is interrupted by the active fuse can be prevented from being applied to the control unit, and the control unit can be protected from the back electromotive force generated in the power path.

[0096] (Technology 2) The shutdown system according to Technology 1, wherein the control unit simultaneously transmits the opening instruction signal and the shutdown instruction signal.

[0097] When the current flowing through the power path indicates an abnormal state, the control unit must send a cutoff instruction signal to the active fuse as quickly as possible after determining that the current flowing through the power path indicates an abnormal state in order to prevent the battery or load from emitting smoke or catching fire. Meanwhile, the control unit must send an open instruction signal to the reversible switch as quickly as possible after determining that the current flowing through the power path indicates an abnormal state in order to protect the control unit from back electromotive force generated in the power path due to the interruption of the power path. Therefore, by simultaneously transmitting the open instruction signal and the cutoff instruction signal as quickly as possible, it is possible to protect the control unit from back electromotive force generated in the power path while preventing the battery from emitting smoke or catching fire.

[0098] (Technology 3) An interruption system described in Technology 1 or 2, in which the control unit first sends the open instruction signal and the cut-off instruction signal, causing the reversible switch to be in an open state, and then the active fuse cuts off the power path.

[0099] Thus, depending on the specifications of the reversible switch and the active fuse, the reversible switch may first be opened, and then the active fuse may cut off the power path.

[0100] (Technology 4) An interruption system described in Technology 1 or 2, in which the control unit sends the open instruction signal and the cut-off instruction signal, causing the reversible switch to be in an open state, and at the same time, the active fuse cuts off the power path.

[0101] Thus, depending on the specifications of the reversible switch and the active fuse, the reversible switch may be in an open state and, at the same time, the active fuse may cut off the power path.

[0102] (Technology 5) A blocking system described in Technology 1 or 2, in which the control unit sends the open instruction signal and the cut-off instruction signal, so that the active fuse first cuts off the power path, and then the reversible switch is opened.

[0103] In this way, depending on the specifications of the reversible switch and the active fuse, the active fuse may first cut off the power path, and then the reversible switch may open. Even in this case, the time during which the back electromotive force generated in the power path is applied to the control unit can be reduced, so the control unit can be protected from the back electromotive force generated in the power path.

[0104] (Technology 6) The interruption system according to any one of Technologies 1 to 5, wherein the interruption system includes two reversible switches, the active fuse is provided between the positive terminal of the battery and the positive terminal of the load in the power path, one of the two reversible switches is provided in a voltage detection wiring that connects the control unit and a node in the power path between the positive terminal of the battery and the active fuse, and the other of the two reversible switches is provided in a voltage detection wiring that connects the control unit and a node in the power path between the active fuse and the positive terminal of the load.

[0105] In the power path connecting the positive terminal of the battery and the positive terminal of the load, when the active fuse interrupts the power path, there is a risk of a back electromotive force being generated between the positive terminal of the battery and the active fuse, and between the active fuse and the positive terminal of the load. Therefore, by providing a reversible switch in the voltage detection wiring corresponding to these two locations, it is possible to prevent the back electromotive force generated at these two locations from being applied to the control unit.

[0106] (Technology 7) A shutdown system described in any of Technologies 1 to 6, wherein, after transmitting the open instruction signal and the shutdown instruction signal, if the control unit determines that the detected current indicates a predetermined state, it transmits a connection instruction signal to the reversible switch to set the reversible switch to a connected state.

[0107] For example, there is a demand for monitoring the status of a battery or a load even after an active fuse has cut off the power path. Therefore, after the active fuse has cut off the power path and the reversible switch has been set to an open state, if the current flowing through the power path is in a predetermined state (e.g., a safe state of 0 A), the reversible switch is set to a closed state. This makes it possible to monitor the voltage of the battery or the voltage applied to the load even after the active fuse has cut off the power path, thereby enabling status diagnosis or abnormality detection.

[0108] (Technology 8) When there are a plurality of voltage detection wirings, the shutdown system is provided with n (n is an integer equal to or greater than 1) reversible switches, and the n reversible switches are provided on m (m is an integer equal to or greater than 1 and equal to or less than n) voltage detection wirings among the plurality of voltage detection wirings that have large inductance at the point where they are connected to the power path. This is a shutdown system described in any one of Technologies 1 to 7.

[0109] According to this, when there are multiple voltage detection wires, it is not necessary to provide a reversible switch for each of the multiple voltage detection wires, and a reversible switch may be preferentially provided for voltage detection wires connected to locations in the power path where inductance is high, i.e., locations where large back electromotive force is likely to occur.

[0110] (Technology 9) An interruption system described in any of Technologies 1 to 8, wherein the control unit determines that the detected current indicates an abnormal state when the amount of change in the detected current per unit time exceeds a predetermined threshold.

[0111] For example, if the magnitude of the detected current exceeds a predetermined value, it may be determined that the detected current indicates an abnormal state. However, in this case, it may take some time for the magnitude of the current to exceed the predetermined value. In contrast, if the current is in an abnormal state, the current tends to increase rapidly in a short period of time. Therefore, by monitoring the amount of change in the detected current per unit time, it is possible to quickly determine whether the current is in an abnormal state. This prevents a large current from continuing to flow through the power path for a long period of time before the active fuse interrupts the power path, thereby preventing damage to components in the interruption system.

[0112] (Technology 10) A shutoff system described in any one of technologies 1 to 9, wherein the current sensor is provided between the negative terminal of the battery and the negative terminal of the load in the power path, and a grounding wire for grounding the control unit is connected to a node between the negative terminal of the battery and the current sensor in the power path.

[0113] For example, if the current sensor is configured as a shunt resistor, the current sensor is provided between the negative terminal of the battery and the negative terminal of the load in the power path, i.e., at a location in the power path where the voltage is low. In this case, when a grounding wire is connected to a node in the power path between the current sensor and the negative terminal of the load, the reference potential of the control unit is affected by a voltage drop due to the current sensor (shunt resistor). Therefore, by connecting the grounding wire to the node in the power path between the negative terminal of the battery and the current sensor, the reference potential of the control unit can be prevented from being affected by the voltage drop due to the current sensor.

[0114] (Technology 11) A shutdown system according to any one of technologies 1 to 10, wherein the active fuse is a pyro fuse.

[0115] Thus, the active fuse may be a pyro fuse.

[0116] (Technology 12) A shut-off method for a shut-off system, the shut-off system being provided in a power path connecting a battery and a load and including: an active fuse for shutting off the power path; a current sensor for detecting a current flowing in the power path; and a reversible switch provided in a voltage detection wiring connecting a node in the power path between a positive terminal of the battery and a positive terminal of the load and a control unit, the shut-off method determining whether the detected current indicates an abnormal state, and if it is determined that the detected current indicates an abnormal state, transmitting an open instruction signal to the reversible switch to open the reversible switch, and transmitting a shut-off instruction signal to the active fuse to shut off the power path.

[0117] This provides a cutoff method that can protect the control unit from the back electromotive force generated in the power line.

[0118] The present disclosure can be applied to a system that uses an active fuse to interrupt a power path.

[0119] 1, 2, 3, 4, 5 Breaking system 10 Battery 11 Load 12 Current sensor 13 Active fuse 14 Control unit 15 Grounding wire 16, 17 Voltage detection wire 18 Current detection wire 20, 21 Reversible switch 30 Power path 40 Breaking wire 41, 42 Control wire A, B, C, D Terminals

Claims

1. An interruption system comprising: an active fuse provided in an electric power path connecting a battery and a load for interrupting the electric power path; a current sensor for detecting a current flowing in the electric power path; a control unit; and a reversible switch provided in a voltage detection wiring connecting the control unit to a node in the electric power path between the positive terminal of the battery and the positive terminal of the load, wherein the control unit determines whether the detected current indicates an abnormal state, and if it determines that the detected current indicates an abnormal state, transmits an open instruction signal to the reversible switch to open the reversible switch, and transmits a cutoff instruction signal to the active fuse to cut off the electric power path.

2. The shutdown system according to claim 1, wherein the control unit transmits the opening instruction signal and the shutdown instruction signal simultaneously.

3. The interruption system according to claim 1 or 2, wherein the control unit transmits the open instruction signal and the interruption instruction signal, so that the reversible switch first goes into an open state, and then the active fuse interrupts the power path.

4. The interruption system according to claim 1 or 2, wherein the control unit transmits the open instruction signal and the cut-off instruction signal, thereby causing the reversible switch to be in an open state and simultaneously causing the active fuse to cut off the power path.

5. The interruption system according to claim 1 or 2, wherein the control unit transmits the open instruction signal and the cutoff instruction signal, so that the active fuse first cuts off the power path, and then the reversible switch is set to an open state.

6. The interruption system according to any one of claims 1 to 5, wherein the interruption system comprises two of the reversible switches, the active fuse is provided between the positive terminal of the battery and the positive terminal of the load in the power path, one of the two reversible switches is provided in a voltage detection wiring that connects the control unit to a node in the power path between the positive terminal of the battery and the active fuse, and the other of the two reversible switches is provided in a voltage detection wiring that connects the control unit to a node in the power path between the active fuse and the positive terminal of the load.

7. The interruption system according to any one of claims 1 to 6, wherein, after transmitting the open instruction signal and the interrupt instruction signal, if the control unit determines that the detected current indicates a predetermined state, it transmits a connection instruction signal to the reversible switch to switch it into a connected state.

8. The interruption system according to any one of claims 1 to 7, wherein when there are a plurality of voltage detection wires, the interruption system comprises n reversible switches (n is an integer of 1 or more), and the n reversible switches are provided on m (m is an integer of 1 or more and n or less) voltage detection wires of the plurality of voltage detection wires that have large inductance at the point where they are connected to the power path.

9. The circuit breaker system according to any one of claims 1 to 8, wherein the control unit determines that the detected current indicates an abnormal state when the amount of change in the detected current per unit time exceeds a predetermined threshold.

10. The interruption system according to any one of claims 1 to 9, wherein the current sensor is provided between the negative terminal of the battery and the negative terminal of the load in the power path, and a grounding wire for grounding the control unit is connected to a node in the power path between the negative terminal of the battery and the current sensor.

11. The interruption system according to any one of claims 1 to 10, wherein the active fuse is a pyro-fuse.

12. A shut-off method for a shut-off system, the shut-off system comprising: an active fuse provided in a power path connecting a battery and a load, for shutting off the power path; a current sensor for detecting a current flowing in the power path; and a reversible switch provided in a voltage detection wiring connecting a node in the power path between the positive terminal of the battery and the positive terminal of the load and a control unit, the shut-off method determining whether the detected current indicates an abnormal state, and if it is determined that the detected current indicates an abnormal state, transmitting an open instruction signal to the reversible switch to open the reversible switch, and transmitting a shut-off instruction signal to the active fuse to shut off the power path.

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