Vehicle power cutoff system

Abstract

To improve reliability relating to an electric power shut-off operation.SOLUTION: A vehicle power shut-off system 1 includes: a shut-off unit 2 having a first power terminal 8 and a second power terminal 10 receiving power supply from an auxiliary equipment battery 14, a shut-off control part 9, and a pyrotechnic shut-off part 11 controlled by the shut-off control part 9 and capable of shutting off power supply from a vehicle propulsion driving power storage part 12 to a vehicle propulsion driving load 13; and a backup unit 3 having a power storage part 7, a first discharge circuit 5 capable of outputting the power of the power storage part 7 to the shut-off control part 9 with a first voltage, a second discharge circuit 6 capable of outputting the power of the power storage part 7 to the pyrotechnic shut-off part 11 with a second voltage having a higher value than that of the first voltage when the first discharge circuit 5 outputs the first voltage to the shut-off control part 9, and a power supply control part 4 controlling operations of the first discharge circuit 5 and the second discharge circuit 6.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle power cutoff system for use in various battery-powered vehicles. [Background technology]

[0002] A conventional cutoff device will be described below. The conventional cutoff device is provided between the propulsion drive power storage device and the propulsion drive load. The power required for the cutoff device to operate is supplied from a storage battery. When the vehicle is damaged due to a collision or the like, the cutoff device immediately cuts off the power supply from the propulsion drive power storage device to the propulsion drive load, preventing the vehicle and passengers from falling into a more dangerous situation due to a current leakage from the propulsion drive power storage device.

[0003] As prior art document information related to the invention of this application, for example, Patent Document 1 is known. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-25912 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional circuit breaker, there is a risk that the circuit breaker may not operate correctly if the power supply from the storage battery becomes unstable.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to improve the reliability of the power cut-off operation. [Means for solving the problem]

[0007] In order to achieve this object, the present disclosure is characterized in comprising a backup unit having a first power terminal and a second power terminal receiving an operating voltage from an auxiliary battery, a cutoff control unit connected to the first power terminal, and a pyrotechnic cutoff unit connected to the second power terminal and controlled by the cutoff control unit, and capable of cutting off power supply from a vehicle propulsion drive storage unit to a vehicle propulsion drive load, a storage unit, a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the storage unit to the cutoff control unit at a first voltage, a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic cutoff unit at a second voltage higher than the first voltage when the first discharge circuit outputs the first voltage to the cutoff control unit, and a power supply control unit that controls the operation of the first discharge circuit and the second discharge circuit. Effect of the Invention

[0008] According to the present invention, the cutoff control unit and the pyrotechnic cutoff unit are capable of receiving power from both the auxiliary battery and the power storage unit. Therefore, even when the voltage of the auxiliary battery becomes temporarily unstable or when the vehicle is involved in an accident and the auxiliary battery fails, a stable power supply from the backup unit to the cutoff control unit required for cutting off power from the vehicle propulsion drive power storage unit to the vehicle propulsion drive load is possible. Furthermore, a sufficiently high voltage can be supplied from the backup unit to the pyrotechnic cutoff unit. This stabilizes the operation of the cutoff control unit and enables the pyrotechnic cutoff unit to operate at high speed, improving the reliability of the power cutoff operation by the cutoff control unit and the pyrotechnic cutoff unit. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a first circuit block diagram showing a configuration of a vehicle power cutoff system according to an embodiment of the present disclosure; [Diagram 2] FIG. 2 is a second circuit block diagram showing the configuration of a vehicle power cutoff system according to an embodiment of the present disclosure; [Diagram 3]FIG. 3 is a third circuit block diagram showing the configuration of a vehicle power cutoff system according to an embodiment of the present disclosure. [Figure 4] A fourth circuit block diagram showing the configuration of a vehicle power cut-off system according to an embodiment of the present disclosure. [Diagram 5] A fifth circuit block diagram showing the configuration of a vehicle power cut-off system according to an embodiment of the present disclosure. [Figure 6] FIG. 1 is a first schematic diagram of a pyrotechnic cutoff unit used in a vehicle power cutoff system according to an embodiment of the present disclosure; [Figure 7] FIG. 2 is a second schematic diagram of a pyrotechnic cutoff unit used in a vehicle power cutoff system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] (Embodiment) 1 is a first circuit block diagram showing a configuration of a vehicle power interruption system according to an embodiment of the present disclosure. The vehicle power interruption system 1 includes a interruption unit 2 and a backup unit 3.

[0012] The backup unit 3 includes a power supply control unit 4, a first discharge circuit 5, a second discharge circuit 6, and a power storage unit 7. The circuit breaker unit 2 includes a first power end 8, a circuit breaker control unit 9 connected to the first power end 8, a second power end 10, and a pyrotechnic circuit breaker unit 11 connected to the second power end 10. The circuit breaker control unit 9 controls the operation of the pyrotechnic circuit breaker unit 11.

[0013] The cutoff unit 2 is capable of supplying and cutting off power from the vehicle propulsion drive power storage unit 12 to the vehicle propulsion drive load 13. The first power terminal 8 and the second power terminal 10 receive the supply of operating power. The first power terminal 8 and the second power terminal 10 are connected to the auxiliary battery 14. The first discharge circuit 5 is connected to the first power terminal 8. The second discharge circuit 6 is connected to the second power terminal 10.

[0014] The power storage unit 7 supplies the stored power to the first discharge circuit 5 and the second discharge circuit 6. The first discharge circuit 5 is capable of outputting a first voltage V1 to the interruption control unit 9 through a first power terminal 8. Furthermore, while the first discharge circuit 5 is outputting the first voltage V1 to the interruption control unit 9, the second discharge circuit 6 is capable of outputting a second voltage V2, which is higher than the first voltage V1, to the pyrotechnic interruption unit 11 through a second power terminal 10.

[0015] With the above configuration and operation, the cutoff control unit 9 and the pyrotechnic cutoff unit 11 are capable of receiving power from both the auxiliary battery 14 and the power storage unit 7. Therefore, even when the vehicle 15 encounters an accident and the auxiliary battery 14 fails, or even if the voltage of the auxiliary battery 14 becomes unstable before the vehicle 15 encounters an accident, the cutoff control unit 9, which executes control to cut off the power from the vehicle propulsion drive power storage unit 12 to the vehicle propulsion drive load 13 by the pyrotechnic cutoff unit 11, can receive a stable power supply from the first discharge circuit 5. Furthermore, it becomes possible to supply a sufficiently high voltage from the second discharge circuit 6 to the pyrotechnic cutoff unit 11. As a result, the operation of the cutoff control unit 9 is stable, the pyrotechnic cutoff unit 11 can perform a high-speed cutoff operation, and the reliability of the power cutoff operation by the cutoff control unit 9 and the pyrotechnic cutoff unit 11 is improved.

[0016] Below, the details of the configuration and operation of the vehicle power cutting system 1 will be described using a second circuit block diagram showing the configuration of the vehicle power cutting system in an embodiment of the present disclosure in FIG. 2, a third circuit block diagram showing the configuration of the vehicle power cutting system in an embodiment of the present disclosure in FIG. 3, a fourth circuit block diagram showing the configuration of the vehicle power cutting system in an embodiment of the present disclosure in FIG. 4, and a fifth circuit block diagram showing the configuration of the vehicle power cutting system in an embodiment of the present disclosure in FIG. 5.

[0017] The vehicle power interruption system 1 is mounted on a vehicle body 16 of a vehicle 15. The interruption unit 2 of the vehicle power interruption system 1 is disposed between the vehicle propulsion drive power storage unit 12 and the vehicle propulsion drive load 13, and is capable of connecting or disconnecting the vehicle propulsion drive power storage unit 12 and the vehicle propulsion drive load 13, and is in the connected state when the vehicle 15 and the vehicle body 16 are in a normal state.

[0018] In other words, the breaker unit 2 is initially in a connected state, and goes into a cut-off state when an accident occurs in the vehicle 15 or the vehicle body 16, or when an overcurrent flows from the vehicle propulsion driving power storage unit 12 to the vehicle propulsion driving load 13. The vehicle propulsion driving power storage unit 12 is provided with a plurality of power storage elements, each of which uses a secondary battery such as a lithium battery as a power storage element to obtain a terminal voltage of, for example, about 500 V. The vehicle propulsion driving load 13 may, for example, be a motor for propelling the vehicle 15 and an inverter device for supplying AC power to the motor.

[0019] The circuit breaker unit 2 is normally operable by using power supplied from the auxiliary battery 14. As described above, the circuit breaker unit 2 includes the first power terminal 8, the circuit breaker control unit 9 connected to the first power terminal 8, and the second power terminal 10, the pyrotechnic circuit breaker unit 11 connected to the second power terminal 10. The circuit breaker control unit 9 controls the operation of the pyrotechnic circuit breaker unit 11. For example, when the vehicle 15 falls into an abnormal state or when an overcurrent or abnormal current occurs in the conductor unit 18 described below, the circuit breaker control unit 9 switches the pyrotechnic circuit breaker unit 11 from a connected state to a disconnected state by physically destroying it.

[0020] Alternatively, the circuit breaker unit 2 can usually be operated by using power supplied from the auxiliary battery 14. The circuit breaker unit 2 includes a first power terminal 8, a circuit breaker control unit 9 connected to the first power terminal 8, and a second power terminal 10, a pyrotechnic circuit breaker unit 11 connected to the second power terminal 10 via a switch 26. The circuit breaker control unit 9 controls the operation of the pyrotechnic circuit breaker unit 11 by executing control to set the switch 26 to a connected state or a disconnected state. For example, when the vehicle 15 falls into an abnormal state or when an overcurrent or an abnormal current occurs in the conductor unit 18 described later, the circuit breaker control unit 9 supplies power to the pyrotechnic circuit breaker unit 11 by changing the switch 26 from a disconnected state to a connected state. The pyrotechnic circuit breaker unit 11 is switched from a connected state to a disconnected state by being physically destroyed.

[0021] Furthermore, the circuit breaker unit 2 is usually operable by using power supplied from the auxiliary battery 14. The circuit breaker unit 2 includes a first power terminal 8 and a circuit breaker control unit 9 connected to the first power terminal 8, and a second power terminal 10 and a switch 26 connected to the second power terminal 10. The circuit breaker control unit 9 receives power from the second power terminal 10 via the switch 26 in a connected state, and can control the operation of the pyrotechnic circuit breaker unit 11. For example, when the vehicle 15 falls into an abnormal state, or when an overcurrent or an abnormal current occurs in the conductor unit 18 described later, the circuit breaker control unit 9 supplies power to the pyrotechnic circuit breaker unit 11 using power supplied from the switch 26 in a connected state. The pyrotechnic circuit breaker unit 11 is switched from the connected state to the cutoff state by being physically destroyed. Although not shown here, the circuit breaker control unit 9 and the switch 26 may be connected by a conductor for control and a conductor for power supply. Although not shown, the second power terminal 10 and the circuit breaker control unit 9 may be directly connected by a conductor for power supply without the switch 26.

[0022] In this embodiment, the cutoff control unit 9 and the switch 26 are described as different elements and circuits, but the cutoff control unit 9 and the switch 26 may be provided as a cutoff circuit unit (not shown) that is a single control circuit. In other words, the cutoff circuit unit (not shown) may be capable of supplying power for operating the pyrotechnic cutoff unit 11 using signals and power supplied from the first power terminal 8 and the second power terminal 10.

[0023] The pyrotechnic cutoff unit 11, particularly, of the cutoff unit 2 has the vehicle propulsion drive power storage unit 12 and the vehicle propulsion drive load 13 connected in an initial state. As shown in the first schematic diagram of the pyrotechnic cutoff unit 11 used in the vehicle power cutoff system in the embodiment of the present disclosure in Fig. 6, the pyrotechnic cutoff unit 11 has a pyrotechnic unit 17 and a conductor unit 18. The pyrotechnic unit 17 further has an energy generation unit 17A that generates large mechanical energy by exploding explosives, etc., and a destruction piece 17B that uses the mechanical energy generated by the energy generation unit 17A as kinetic energy to cause a position change. The cutoff control unit 9 issues a cutoff instruction to the pyrotechnic cutoff unit 11, thereby causing the pyrotechnic cutoff unit 11 to execute a cutoff operation of detonating the pyrotechnic unit 17 and destroying the conductor unit 18. In other words, the pyrotechnic unit 17 receives a signal for initiating detonation by the energy generating unit 17A from the cutoff control unit 9, and power for promoting the detonation in the energy generating unit 17A from the second power terminal 10.

[0024] Alternatively, as shown in the second schematic diagram of the pyrotechnic cutoff unit 11 used in the vehicle power cutoff system in the embodiment of the present disclosure in FIG. 7, the pyrotechnic unit 17 may receive power from the second power terminal 10 through the switch 26 switched from the cutoff state to the connected state under the control of the cutoff control unit 9 in order to detonate the energy generating unit 17A. Then, by detonating the energy generating unit 17A, the destructive piece 17B irreversibly mechanically destroys the conductor unit 18, and the connection state between the vehicle propulsion drive storage unit 12 and the vehicle propulsion drive load 13 is switched to the cutoff state. Here, the destructive piece 17B is generally a blade-shaped metal piece or a bullet-shaped metal piece, but it is not limited to a metal piece as long as it is a material that can destroy and cut the conductor unit 18.

[0025] Here, the cut-off control unit 9 of the cut-off unit 2 changes the state of the pyrotechnic cut-off unit 11 from the connected state to the cut-off state when the vehicle control unit 19 mounted on the vehicle body 16 detects the occurrence of an accident, etc. and the cut-off control unit 9 receives a cut-off instruction from the vehicle control unit 19, or when the cut-off control unit 9 detects an overcurrent in the cut-off unit 2.

[0026] As described above, when the auxiliary battery 14 or the vehicle 15 is normal, the power supplied from the first power terminal 8 to the cutoff control unit 9 to enable the cutoff control unit 9 to operate is supplied by the auxiliary battery 14. Also, when the auxiliary battery 14 or the vehicle 15 is normal, the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A is supplied by the auxiliary battery 14.

[0027] Here, the backup unit 3 is connected to the first power terminal 8 and the second power terminal 10. Strictly speaking, the first power terminal 8 is connected to the first discharge circuit 5. Furthermore, the second power terminal 10 is connected to the second discharge circuit 6. The first discharge circuit 5 and the second discharge circuit 6 are capable of outputting voltage or supplying power from the first power terminal 8 to the interruption control unit 9 or from the second power terminal 10 to the pyrotechnic interruption unit 11, using the power stored in the power storage unit 7. In other words, the auxiliary battery 14 and the backup unit 3 are connected in parallel to the first power terminal 8 and the second power terminal 10.

[0028] The first discharge circuit 5 and the second discharge circuit 6 may be independent circuits, or may be configured as circuits capable of outputting different voltages using a voltage divider circuit. Here, the first discharge circuit 5 and the second discharge circuit 6 may use a DC-DC converter so that they can be started at different times and controlled by the power supply control unit 4 to stably and continuously output different powers.

[0029] As a result, the cutoff control unit 9 and the pyrotechnic cutoff unit 11 are capable of receiving power supply from both the auxiliary battery 14 and the power storage unit 7. For this reason, even when the vehicle 15 is involved in an accident and the auxiliary battery 14 fails, or even if the voltage of the auxiliary battery 14 becomes unstable before the vehicle 15 is involved in an accident, the cutoff control unit 9, which executes control to cut off the power from the vehicle propulsion drive power storage unit 12 to the vehicle propulsion drive load 13 by the pyrotechnic cutoff unit 11, can receive a stable power supply from the first discharge circuit 5.

[0030] Here, the second voltage V2 that the second discharge circuit 6 can output to the pyrotechnic cutoff unit 11 through the second power terminal 10 is set to a higher voltage value than the first voltage V1 that the first discharge circuit 5 can output to the cutoff control unit 9 through the first power terminal 8. The cutoff control unit 9 is composed of a calculation element and a memory element, and therefore can perform control and detection operations at a low voltage value of, for example, about 3V to 5V. On the other hand, when the pyrotechnic cutoff unit 11 operates, a high voltage of, for example, about 10V can be applied to the pyrotechnic cutoff unit 11 to allow a large current to flow to the pyrotechnic section 17 of the pyrotechnic cutoff unit 11, and the speed of detonation in the energy generation unit 17A can be increased. Therefore, when power is supplied to the cutoff control unit 9 through the first power terminal 8 and power is supplied to the pyrotechnic cutoff unit 11 through the second power terminal 10, the cutoff speed in the pyrotechnic cutoff unit 11 is improved, and the reliability of the cutoff is also improved.

[0031] Here, the backup unit 3 may be provided with a diode 20 that connects the first power terminal 8 and the first discharge circuit 5. Similarly, the backup unit 3 may be provided with a diode 20 that connects the second power terminal 10 and the second discharge circuit 6. Here, the anode of the diode 20 is connected to the first discharge circuit 5 and the second discharge circuit 6. Also, the cathode of the diode 20 is connected to the first power terminal 8 and the second power terminal 10. As a result, when the auxiliary battery 14 is normal or when the vehicle 15 is normal, even if the voltage supplied by the auxiliary battery 14 to the first power terminal 8 and the second power terminal 10 is a standard voltage V0 that is higher than the first voltage V1 or the second voltage V2, the power does not flow back to the backup unit 3.

[0032] The voltage supplied to the first power terminal 8 and the second power terminal 10 by the auxiliary battery 14 may be supplied at different voltage values ​​from the auxiliary battery 14 to the first power terminal 8 and the second power terminal 10 via the voltage conversion circuit 21 by providing the voltage conversion circuit 21 in the vehicle power cutoff system 1. At this time, the first power terminal 8 receives a first steady-state voltage V01 from the auxiliary battery 14 via the voltage conversion circuit 21, and the second power terminal 10 receives a second steady-state voltage V02 from the auxiliary battery 14 via the voltage conversion circuit 21. At this time, the voltage conversion circuit 21 may have two independent DCDC converters, and each DCDC converter may supply the first steady-state voltage V01 and the second steady-state voltage V02. Alternatively, the first steady-state voltage V01 and the second steady-state voltage V02 may be supplied by a voltage divider circuit included in the voltage conversion circuit 21.

[0033] Here, by setting the first voltage V1 described above to a value lower than the first steady-state voltage V01, even if the first voltage is output from the first discharge circuit 5, no power is actually discharged from the first discharge circuit 5, and the power stored in the storage unit 7 can be maintained.

[0034] With the above configuration and operation, the cutoff control unit 9 and the pyrotechnic cutoff unit 11 are capable of receiving power from both the auxiliary battery 14 and the power storage unit 7. Therefore, even when the vehicle 15 encounters an accident and the auxiliary battery 14 fails, or even if the voltage of the auxiliary battery 14 becomes unstable before the accident, the cutoff control unit 9, which executes control to cut off the power from the vehicle propulsion drive power storage unit 12 to the vehicle propulsion drive load 13 by the pyrotechnic cutoff unit 11, can receive a stable power supply from the first discharge circuit 5. Furthermore, it is possible to supply a sufficiently high voltage and a large current from the second discharge circuit 6 to the pyrotechnic cutoff unit 11. As a result, the operation of the cutoff control unit 9 is stable, the pyrotechnic cutoff unit 11 can perform a high-speed cutoff operation, and the reliability of the power cutoff operation by the cutoff control unit 9 and the pyrotechnic cutoff unit 11 is improved.

[0035] The operation of the backup unit 3 will be described in detail below. The backup unit 3 may start operating in response to the start of the vehicle 15. For example, in response to the vehicle start-up signal receiving end 4A provided in the power supply control unit 4 receiving a vehicle start-up signal from a device provided in the vehicle 15, such as the vehicle control unit 19, the power supply control unit 4 may execute control to make the first discharge circuit 5 output the first voltage V1. Here, the first discharge circuit 5 may output the first voltage V1 at the same time that the vehicle start-up signal receiving end 4A receives the vehicle start-up signal, or may output the first voltage V1 at a timing that is a predetermined time after the vehicle start-up signal receiving end 4A receives the vehicle start-up signal and before the vehicle 15 starts running.

[0036] Furthermore, the power supply control section 4 executes control so as to cause the second discharge circuit 6 to output the second voltage V2. Here, the second discharge circuit 6 may output the second voltage V2 at the same time as it starts to output the first voltage V1 to the first discharge circuit 5, or after it starts to output the first voltage V1 to the first discharge circuit 5. In other words, the first discharge circuit 5 starts to operate preferentially. Therefore, the interruption control section 9 of the breaking unit 2 is preferentially placed in a state in which it has a backup of driving power, and the operation of the pyrotechnic interruption section 11 requires that the interruption control section 9 is operating, thereby improving the operational reliability of the breaking unit 2.

[0037] Here, the first voltage V1 can operate the cutoff control unit 9 and has a voltage value lower than the first steady-state voltage V01, and the second voltage V2 has a voltage value lower than the second steady-state voltage V02. Therefore, if the auxiliary battery 14 is normal, no power is output even if the backup unit 3 applies a voltage. Therefore, the power stored in the power storage unit 7 is not wasted and can be maintained for a long period of time.

[0038] As a result, the backup unit 3 starts operating in response to the start-up of the vehicle 15, and in particular the first discharge circuit 5 is in a state in which it can supply power to the interruption control section 9 of the interruption unit 2 almost all the time while the vehicle 15 is running. Furthermore, the second discharge circuit 6 is also in a state in which it can supply power to the pyrotechnic interruption section 11 of the interruption unit 2 almost all the time while the vehicle 15 is running. As a result, even if the auxiliary battery 14 fails due to an accident of the vehicle 15, the interruption unit 2 can operate without interruption.

[0039] The operation of the backup unit 3 may be performed, for example, based on the start-up of the vehicle 15 and information about the accident from the vehicle 15 or the vehicle body 16.

[0040] Here, in response to the vehicle start-up signal received by the vehicle start-up signal receiving end 4A provided in the power supply control unit 4 from a device provided in the vehicle 15 such as the vehicle control unit 19, the power supply control unit 4 executes control to make the first discharge circuit 5 output the first voltage V1. Thereafter, when the first receiving end 4B provided in the power supply control unit 4 receives a vehicle accident signal from a device provided in the vehicle 15 such as the vehicle control unit 19, the power supply control unit 4 executes control to make the second discharge circuit 6 output the second voltage V2. Furthermore, the second receiving end 9A provided in the cut-off control unit 9, which is capable of receiving the vehicle accident signal, receives the vehicle accident signal simultaneously with the power supply control unit 4. Then, the cut-off control unit 9 causes the pyrotechnic cut-off unit 11 to perform a cut-off operation.

[0041] As a result, the backup unit 3 begins operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is able to supply power to the cut-off control unit 9 of the cut-off unit 2 almost at all times while the vehicle 15 is started.

[0042] Further, here, the second discharge circuit 6 supplies power to the pyrotechnic cutoff unit 11 when the vehicle 15 encounters an accident. Then, when the vehicle 15 encounters an accident, the pyrotechnic cutoff unit 11 receives an instruction to perform cutoff from the cutoff control unit 9. This allows the cutoff unit 2 to operate without interruption even if the auxiliary battery 14 fails due to an accident of the vehicle 15 or the like. Alternatively, when the vehicle 15 encounters an accident, the cutoff control unit 9 switches the switch 26 from the cutoff state to the connected state, and the pyrotechnic cutoff unit 11 receives power supply from the second power terminal 10 and switches to the cutoff state. This allows the cutoff unit 2 to operate without interruption even if the auxiliary battery 14 fails due to an accident of the vehicle 15 or the like. Here, it is preferable to use a semiconductor switch such as a field effect transistor (FET) for the switch 26.

[0043] Moreover, regardless of the state of the auxiliary battery 14, the second discharge circuit 6 can output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be increased in value. As a result, the cutoff speed of the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

[0044] The operation of the backup unit 3 may also be based on, for example, the start-up of the vehicle 15 and information regarding the occurrence of an overcurrent in the pyrotechnic breaker 11 .

[0045] Here, in response to the vehicle start signal issued from a device provided in the vehicle 15 such as the vehicle control unit 19 being received by the vehicle start signal receiving end 4A provided in the power supply control unit 4, the power supply control unit 4 executes control so as to make the first discharge circuit 5 output the first voltage V1. After that, the current detection circuit 11A provided in the pyrotechnic circuit breaker 11 starts to detect the current flowing through the conductor 18. Then, when the current detection circuit 11A detects that the current flowing through the conductor 18 exceeds the overcurrent threshold, it transmits an overcurrent detection signal to the detection signal receiving unit 9B of the circuit breaker control unit 9. At this time, the power supply control unit 4 also receives an overcurrent detection signal at the third receiving end 4C from the current detection circuit 11A or the circuit breaker control unit 9. When the power supply control unit 4 receives the overcurrent detection signal, it makes the second discharge circuit 6 output the second voltage V2. Also, the circuit breaker control unit 9 instructs the pyrotechnic circuit breaker unit 11 to perform circuit breaker. Alternatively, the cutoff control unit 9 controls the switch 26 to switch from the cutoff state to the connected state, causing the pyrotechnic cutoff unit 11 to perform cutoff.

[0046] As a result, the backup unit 3 begins operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is in a state in which it is able to supply power to the cut-off control unit 9 of the cut-off unit 2 at almost all times while the vehicle 15 is started.

[0047] Furthermore, here, the second discharge circuit 6 supplies power to the pyrotechnic breaker unit 11 when a short circuit occurs in the vehicle propulsion drive load 13 or the like due to the vehicle 15 encountering an accident or the like, causing an overcurrent to flow in the conductor unit 18. Then, when an overcurrent occurs in the conductor unit 18, the pyrotechnic breaker unit 11 receives an instruction to perform a break from the breaker control unit 9. Alternatively, when an overcurrent flows in the conductor unit 18, the breaker control unit 9 controls the switch 26 to switch from a cut-off state to a connected state, causing the pyrotechnic breaker unit 11 to perform a break. This allows the breaker unit 2 to operate uninterruptedly even if the auxiliary battery 14 fails due to an accident of the vehicle 15 or the like.

[0048] At this time, regardless of the state of the auxiliary battery 14, the second discharge circuit 6 can output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be increased in value. As a result, the cutoff speed of the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

[0049] For ease of explanation, the current detection circuit 11A, the cutoff control unit 9, and the detection signal receiving unit 9B are explained as separate elements here. However, these may be collectively considered as functions included in the cutoff control unit 9.

[0050] In other words, in the above description, the current detection circuit 11A detects the current flowing through the conductor 18 as a detection voltage value using a shunt resistor (not shown) or a Hall element (not shown), and the current detection circuit 11A has a function of using a calculation device (not shown) to compare the detected voltage value with a voltage value corresponding to an overcurrent threshold value previously stored in a storage device (not shown). The result of the calculation device (not shown) judging that the current flowing through the conductor 18 exceeds the overcurrent threshold corresponds to the transmission of an overcurrent detection signal. As described above, the storage device (not shown) and the calculation device (not shown) are considered as elements constituting the current detection circuit 11A, separate from the interruption control unit 9. However, the function of the current detection circuit 11A, including the storage device (not shown) and the calculation device (not shown), may be provided in the interruption control unit 9. In other words, it may be considered that the interruption control unit 9 having the current detection circuit 11A and the detection signal receiving unit 9B is provided in the pyrotechnic interruption unit 11, except for the shunt resistor (not shown) and the Hall element (not shown).

[0051] The operation of the backup unit 3 may also be performed based on, for example, the start-up of the vehicle 15, the state of the power supply from the auxiliary battery 14, and information regarding an accident from the vehicle 15 or the vehicle body 16.

[0052] Here, in response to a vehicle start-up signal issued from a device provided in the vehicle 15, such as a vehicle control unit 19, being received by a vehicle start-up signal receiving end 4A provided in the power supply control unit 4, the power supply control unit 4 executes control to make the first discharge circuit 5 output a first voltage V1. In addition, when the vehicle start-up signal receiving end 4A receives the vehicle start-up signal, the power supply control unit 4 detects the voltage of a power receiving end 22 provided in the backup unit 3. The auxiliary battery 14 supplies power to the power storage unit 7 through the power receiving end 22. Alternatively, the auxiliary battery 14 charges the power storage unit 7 through the power receiving end 22.

[0053] Thereafter, when the power supply control unit 4 detects that the voltage at the power receiving end 22 has dropped below the battery voltage threshold while the vehicle start-up signal receiving end 4A is receiving the vehicle start-up signal, in other words, while the vehicle 15 is in a driving state, the power supply control unit 4 causes the second discharge circuit 6 to output the second voltage V2. Furthermore, the power supply control unit 4 transmits a vehicle accident signal to the second receiving end 9A, which is provided in the cut-off control unit 9 and is capable of receiving a vehicle accident signal. Then, the cut-off control unit 9 causes the pyrotechnic cut-off unit 11 to perform a cut-off operation. Alternatively, the cut-off control unit 9 controls the switch 26 to switch from a cut-off state to a connected state, causing the pyrotechnic cut-off unit 11 to perform a cut-off operation.

[0054] As a result, the backup unit 3 begins operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is able to supply power to the cut-off control unit 9 of the cut-off unit 2 almost at all times while the vehicle 15 is started.

[0055] Furthermore, in this case, even though the vehicle 15 is being driven, the voltage of the auxiliary battery 14 drops below the battery voltage threshold, causing the second discharge circuit 6 to supply power to the pyrotechnic cutoff unit 11. Then, the power supply control unit 4 issues a cutoff instruction to the cutoff control unit 9 to forcibly cause the pyrotechnic cutoff unit 11 to perform cutoff. In other words, in response to a battery failure state in which the auxiliary battery 14 is lost while the vehicle 15 is being driven, the second discharge circuit 6 supplies power to the pyrotechnic cutoff unit 11 and further causes the pyrotechnic cutoff unit 11 to perform cutoff. For this reason, the battery voltage threshold may be set to a level close to 0V, which is a low value far removed from the battery voltage fluctuation range that does not normally occur. This suppresses erroneous detection of battery failure.

[0056] As a result, even if the auxiliary battery 14 fails due to an accident involving the vehicle 15, the circuit breaker unit 2 can operate continuously to prevent leakage current, regardless of whether an overcurrent condition exists.

[0057] Here, the second discharge circuit 6 can output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be increased in value. As a result, the cutoff speed of the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

[0058] The operation of the backup unit 3 may also be performed based on, for example, the start-up of the vehicle 15, the state of the power supply from the auxiliary battery 14, and information regarding the occurrence of an overcurrent in the pyrotechnic breaker unit 11.

[0059] Here, in response to a vehicle start-up signal issued from a device provided in the vehicle 15, such as a vehicle control unit 19, being received by a vehicle start-up signal receiving end 4A provided in the power supply control unit 4, the power supply control unit 4 executes control to make the first discharge circuit 5 output a first voltage V1. In addition, when the vehicle start-up signal receiving end 4A receives the vehicle start-up signal, the power supply control unit 4 detects the voltage of a power receiving end 22 provided in the backup unit 3. The auxiliary battery 14 supplies power to the power storage unit 7 through the power receiving end 22. Alternatively, the auxiliary battery 14 charges the power storage unit 7 through the power receiving end 22.

[0060] Thereafter, when the vehicle start-up signal receiving end 4A is receiving the vehicle start-up signal, in other words, when the vehicle 15 is in a driving state and the power supply control unit 4 detects that the voltage of the power receiving end 22 has dropped below the battery voltage threshold, the power supply control unit 4 causes the second discharge circuit 6 to output the second voltage V2. Further thereafter, the interruption control unit 9 detects the occurrence of an overcurrent in the conductor part 18, and the pyrotechnic breaker unit 11 receives an instruction to perform interruption from the interruption control unit 9. Alternatively, when the interruption control unit 9 detects the occurrence of an overcurrent in the conductor part 18, the interruption control unit 9 controls the switch 26 to switch from the interrupted state to the connected state, and causes the pyrotechnic breaker unit 11 to perform interruption.

[0061] As a result, the backup unit 3 begins operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is able to supply power to the cut-off control unit 9 of the cut-off unit 2 almost at all times while the vehicle 15 is started.

[0062] Furthermore, in this case, even though the vehicle 15 is being driven, the voltage of the auxiliary battery 14 drops below the battery voltage threshold, causing the second discharge circuit 6 to be in a state in which it is possible to supply power to the pyrotechnic cutoff unit 11. After this, when an overcurrent occurs, the pyrotechnic cutoff unit 11 executes cutoff. In other words, in response to a battery failure state in which the auxiliary battery 14 is lost while the vehicle 15 is being driven, the second discharge circuit 6 is in a state in which it is possible to supply power to the pyrotechnic cutoff unit 11. For this reason, the battery voltage threshold may be set to a level close to 0V, which is a low value far removed from the battery voltage fluctuation range that would not normally occur. This suppresses erroneous detection of battery failure.

[0063] As a result, even if the auxiliary battery 14 fails due to an accident of the vehicle 15, sufficient voltage and power can be supplied to the pyrotechnic breaker section 11 when an overcurrent state occurs, and the breaker unit 2 can operate normally. If there is a time difference between the timing when the battery fails while the vehicle 15 is being driven and the timing when the breaker control section 9 detects an overcurrent, the second discharge circuit 6 may have a standby state in which it maintains a state in which it can supply power to the pyrotechnic breaker section 11 and waits for the breaker control section 9 to detect an overcurrent.

[0064] Here, the procedure when the interruption control section 9 and the current detection circuit 11A detect an overcurrent in the conductor section 18 may be the same as that described above.

[0065] The second discharge circuit 6 can also output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be increased in value. As a result, the cutoff speed of the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

[0066] The operation of the backup unit 3 may also be carried out based on, for example, a prediction of a collision in the vehicle 15 and information about an accident from the vehicle 15 or the vehicle body 16 or information about the occurrence of an overcurrent in the pyrotechnic breaker 11.

[0067] Here, in response to a danger prediction signal, such as a collision prediction signal, issued from a device provided in the vehicle 15, such as the vehicle control unit 19, being received by the fourth receiving end 4D provided in the power supply control unit 4 as a vehicle start signal, the power supply control unit 4 executes control to make the first discharge circuit 5 output the first voltage V1. Then, the power supply control unit 4 executes control to make the second discharge circuit 6 output the second voltage V2. The timing at which the first voltage V1 is output may precede the timing at which the second voltage V2 is output, but it is preferable that the first voltage V1 and the second voltage V2 are output simultaneously.

[0068] Then, when the cut-off control unit 9 receives a vehicle accident signal at the second receiving end 9A provided in the cut-off control unit 9, or when the current detection circuit 11A of the cut-off unit 2 detects that the current flowing through the conductor portion 18 has exceeded the overcurrent threshold, the cut-off control unit 9 causes the pyrotechnic cut-off unit 11 to perform a cut-off operation.

[0069] In other words, at the point in time when a dangerous state is approaching before an accident such as a collision occurs in the vehicle 15, the power supply control unit 4 executes control to make the first discharge circuit 5 output the first voltage V1 and the second discharge circuit 6 output the second voltage V2, regardless of the state of the auxiliary battery 14. Then, thereafter, when the vehicle 15 actually encounters an accident or when an overcurrent occurs as a result of the vehicle 15 encountering an accident, the cutoff control unit 9 causes the pyrotechnic cutoff unit 11 to execute a cutoff operation. Alternatively, when the vehicle 15 actually encounters an accident or when an overcurrent occurs as a result of the vehicle 15 encountering an accident, the cutoff control unit 9 controls the switch 26 to switch from the cutoff state to the connected state, causing the pyrotechnic cutoff unit 11 to execute a cutoff.

[0070] This enables the backup unit 3 to supply all the power required by the cutoff unit 2 before the vehicle 15 encounters an accident, regardless of the state of the auxiliary battery 14. Therefore, when the vehicle 15 encounters an accident and the cutoff unit 2 needs to operate, it can operate immediately and normally.

[0071] Here, the procedure when the interruption control section 9 and the current detection circuit 11A detect an overcurrent in the conductor section 18 may be the same as that described above.

[0072] The second discharge circuit 6 can also output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be increased in value. As a result, the cutoff speed of the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

[0073] The power storage unit 7 of the backup unit 3 is charged by receiving power from the auxiliary battery 14 via the power receiving end 22. Here, a charging circuit 23 may be provided between the power receiving end 22 and the power storage unit 7. In other words, the charging circuit 23 is provided in the charging path of the power storage unit 7, and the first discharge circuit 5 and the charging circuit 23 are provided in parallel in the discharging path of the power storage unit 7. Here, it is preferable that the charging circuit 23 adjusts the charging state and charging speed of the power storage unit 7 under the control of the power supply control unit 4. The charging circuit 23 may charge the power storage unit 7 by either a step-up operation or a step-down operation.

[0074] In response to a vehicle start signal being received by a vehicle start signal receiving terminal 4A provided in the power supply control unit 4, the charging circuit 23 ,versus In addition, before charging is performed when vehicle 15 is started, some amount of power may be stored in power storage unit 7 as residual power.

[0075] It is desirable to use, for the power storage element (not shown) of power storage unit 7, an element capable of discharging at a large current density, such as an electric double layer capacitor or a lithium ion capacitor.

[0076] In the above embodiment, the connection points for transmitting signals and power between the components are given specific names such as the vehicle activation signal receiving end 4A, the first receiving end 4B, the second receiving end 9A, the third receiving end 4C, the fourth receiving end 4D, the first power end 8, and the second power end 10 for convenience of explanation. The above connection points may be replaced with terminals, but on the other hand, the conductors themselves that connect the components or parts of the electric circuit may correspond to the above connection points. In other words, it is not necessary to provide connection points as specific components.

[0077] In the above embodiment, the vehicle start signal receiving end 4A, the first receiving end 4B, the third receiving end 4C, and the fourth receiving end 4D are described as being different receiving ends for the sake of convenience. However, the vehicle start signal receiving end 4A, the first receiving end 4B, the third receiving end 4C, and the fourth receiving end 4D may be different receiving ends, or may be a single receiving end, or may be any multiple receiving ends, as long as the power supply control unit 4 can recognize what kind of signal the power supply control unit 4 has received.

[0078] As explained above, the second voltage V2 supplied from the second discharge circuit 6 to the pyrotechnic cutoff unit 11 through the second power terminal 10 is set to a higher value than the first voltage V1 supplied from the first discharge circuit 5 to the cutoff control unit 9 through the first power terminal 8. Since the cutoff control unit 9 mainly performs calculations, storage, and control, its power consumption is small, and the current flowing through the first power terminal 8 is of a weak value. On the other hand, although the operating time of the energy generating unit 17A of the pyrotechnic cutoff unit 11 is very short and short compared to the cutoff control unit 9, the power consumption of the pyrotechnic cutoff unit 11 during operation is greater than the power consumption of the cutoff control unit 9, and a current of a larger value than that of the first power terminal 8 flows through the second power terminal 10.

[0079] Therefore, the second conductor 25 connecting the second discharge circuit 6 and the pyrotechnic cutoff unit 11 has a larger cross-sectional area and a larger current capacity than the first conductor 24 connecting the first discharge circuit 5 and the cutoff control unit 9. This stabilizes the power supply from the second discharge circuit 6 to the pyrotechnic cutoff unit 11, improving the operational reliability of the pyrotechnic cutoff unit 11. [Industrial Applicability]

[0080] The vehicle power cut-off system of the present invention has the effect of improving the reliability of the power cut-off operation, and is useful in various battery-powered vehicles. [Explanation of symbols]

[0081] 1 Vehicle power cut-off system 2. Breaking unit 3. Backup Unit 4 Power supply control unit 4A Vehicle start signal receiving terminal 4B First receiving end 4C Third receiving end 4D 4th receiving end 5 1st discharge circuit 6 Second discharge circuit 7. Power storage unit 8 1st power end 9. Shutoff control section 10 2nd power end 11 Pyrotechnics Breaking Section 11A current detection circuit 12 Vehicle propulsion drive power storage unit 13 Vehicle propulsion drive load 14 Auxiliary battery 15 Vehicles 16 Body 17 Pyrotechnic Department 17A Energy Generation Unit 17B Demolition Fragment 18 Conductor 19 Vehicle control unit 20 Diode 21 Voltage conversion circuit 22 Receiving end 23 Charging circuit 24 First Conductor 25 Second Conductor

Claims

1. a cutoff unit having a first power terminal and a second power terminal that receive an operating voltage from an auxiliary battery, a cutoff control unit connected to the first power terminal, and a pyrotechnic cutoff unit that is connected to the second power terminal and controlled by the cutoff control unit, and capable of cutting off power supply from the vehicle propulsion drive power storage unit to a vehicle propulsion drive load; A power storage unit; a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the power storage unit to the cutoff control unit at a first voltage; a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic interrupter at a second voltage higher than the first voltage when the first discharge circuit outputs a first voltage to the interrupter control unit; a power supply control unit that controls operations of the first discharge circuit and the second discharge circuit; A backup unit having Equipped with Vehicle power cutoff system.

2. a cutoff unit having a first power terminal and a second power terminal that receive an operating voltage from an auxiliary battery, a cutoff control unit connected to the first power terminal, and a pyrotechnic cutoff unit connected to the second power terminal via a switch that is controlled to be opened or closed by the cutoff control unit, and capable of cutting off power supply from the vehicle propulsion drive power storage unit to a vehicle propulsion drive load; A power storage unit; a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the power storage unit to the cutoff control unit at a first voltage; a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic interrupter at a second voltage higher than the first voltage when the first discharge circuit outputs a first voltage to the interrupter control unit; a power supply control unit that controls operations of the first discharge circuit and the second discharge circuit; A backup unit having Equipped with Vehicle power cutoff system.

3. a cutoff unit having a first power terminal and a second power terminal that receive an operating voltage from an auxiliary battery, a cutoff control unit that is connected to the first power terminal and is connected to the second power terminal via a switch, and a pyrotechnic cutoff unit that can be supplied with power by the cutoff control unit, and capable of cutting off power supply from the vehicle propulsion drive power storage unit to a vehicle propulsion drive load; A power storage unit; a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the power storage unit to the cutoff control unit at a first voltage; a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic interrupter at a second voltage higher than the first voltage when the first discharge circuit outputs a first voltage to the interrupter control unit; a power supply control unit that controls operations of the first discharge circuit and the second discharge circuit; A backup unit having Equipped with Vehicle power cutoff system.

4. The pyrotechnic interruption unit includes: a conductor section capable of supplying electric power from the vehicle propulsion drive power storage section to the vehicle propulsion drive load; A pyrotechnic part capable of destroying the conductor part, The cutoff control unit issues a cutoff instruction to the pyrotechnic cutoff unit, or switches a switch connecting the cutoff control unit to the second power end from a cutoff state to a connected state, thereby causing the pyrotechnic cutoff unit to execute a cutoff operation to detonate the pyrotechnic unit and destroy the conductor unit.

4. The vehicle power cutoff system according to claim 1.

5. The power supply control unit further includes a vehicle start signal receiving terminal capable of receiving a vehicle start signal; The power supply control unit is causing the first discharge circuit to output the first voltage in response to receiving the vehicle start signal, and causing the second discharge circuit to output the second voltage at the same time as the first discharge circuit outputs the first voltage or after the first discharge circuit outputs the first voltage; 5. The vehicle power cutoff system according to claim 4.

6. The power supply control unit includes a vehicle start signal receiving end capable of receiving a vehicle start signal and a first receiving end capable of receiving a vehicle accident signal. The cut-off control unit further includes a second receiving end capable of receiving the vehicle accident signal, the power supply control unit causes the first discharge circuit to output the first voltage in response to receiving the vehicle start signal, and causes the second discharge circuit to output the second voltage when receiving the vehicle accident signal; The cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation when the vehicle accident signal is received.

5. The vehicle power cutoff system according to claim 4.

7. The pyrotechnic circuit breaker includes a current detection circuit capable of detecting an overcurrent flowing in the conductor, The cutoff control unit includes a detection signal receiving unit capable of receiving an overcurrent detection signal generated by the current detection circuit, The power supply control unit includes a vehicle start signal receiving end capable of receiving a vehicle start signal, and a third receiving end capable of receiving the overcurrent detection signal from the cutoff control unit or the current detection circuit. Furthermore, the power supply control unit causes the first discharge circuit to output the first voltage in response to receiving the vehicle start signal, and causes the second discharge circuit to output the second voltage when the overcurrent detection signal is received at the third receiving end; The cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation when the detection signal receiving unit receives the overcurrent detection signal.

5. The vehicle power cutoff system according to claim 4.

8. a power receiving terminal for supplying power from the auxiliary battery to the power storage unit, The power supply control unit further has a vehicle start-up signal receiving terminal capable of receiving a vehicle start-up signal and is capable of detecting a voltage of the receiving terminal; The cut-off control unit further includes a second receiving end capable of receiving a vehicle accident signal, When the power supply control unit detects that the voltage at the power receiving end has dropped below a threshold value while receiving the vehicle start-up signal after causing the first discharge circuit to output the first voltage in response to receiving the vehicle start-up signal, 5. The vehicle power cut-off system according to claim 4, wherein the power supply control unit causes the second discharge circuit to output the second voltage and transmits the vehicle accident signal to the cut-off control unit, and the cut-off control unit causes the pyrotechnic cut-off unit to perform the cut-off operation.

9. a power receiving terminal for supplying power from the auxiliary battery to the power storage unit, The power supply control unit further has a vehicle start-up signal receiving terminal capable of receiving a vehicle start-up signal and is capable of detecting a voltage of the receiving terminal; The interruption control unit further includes a current detection circuit that detects a current flowing through the pyrotechnic interruption unit, When the power supply control unit detects that the voltage at the power receiving end has dropped below a threshold value while receiving the vehicle start-up signal after causing the first discharge circuit to output the first voltage in response to receiving the vehicle start-up signal, The power supply control unit causes the second discharge circuit to output the second voltage, and thereafter, when the current detection circuit detects an overcurrent, the cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation.

5. The vehicle power cutoff system according to claim 4.

10. The power supply control unit includes a fourth receiving unit capable of receiving a danger prediction signal, The cutoff control unit includes at least one of a second receiving unit capable of receiving a vehicle accident signal and a current detection circuit that detects a current flowing through the pyrotechnic cutoff unit, Furthermore, the power supply control unit causes the first discharge circuit to output the first voltage in response to receiving the danger prediction signal, and further causes the second discharge circuit to output the second voltage; The cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation when the vehicle accident signal is received or when the current detection circuit detects that the current has exceeded a threshold value.

5. The vehicle power cutoff system according to claim 4.

11. The backup unit further includes a charging circuit for charging the power storage unit, The power supply control unit further includes a vehicle start-up signal receiving terminal capable of receiving a vehicle start-up signal, In response to the vehicle startup signal receiving terminal receiving the vehicle startup signal, the charging circuit charges the power storage unit using power supplied via a power receiving terminal connected to the charging circuit.

5. The vehicle power cutoff system according to claim 4.

12. A voltage conversion circuit is further provided, the first power terminal is supplied with a first steady voltage from the auxiliary battery via the voltage conversion circuit, and the second power terminal is supplied with a second steady voltage from the auxiliary battery via the voltage conversion circuit; 5. The vehicle power cutoff system according to claim 4.

13. The first voltage is lower than the first steady voltage.

13. The vehicle power cutoff system of claim 12.

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