Control method for power storage device and current interruption device

Abstract

To provide a power storage device which improves safety of a vehicle by securing a power source in the case of emergency.SOLUTION: A power storage device 50 comprises: a power storage cell 62, a current cutoff device 53 which cuts off a current I of the power storage cell 62; and a control unit 121. The control unit 121 cuts off the current by open-circuiting the current cutoff device 53 in a case where abnormality of the power storage device 50 is detected at the time of a vehicle crush, and restarts power supply to a crushed vehicle by close-circuiting the current cutoff device 53 in a case where the abnormality is not detected any more.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a technology for improving vehicle safety by ensuring power supply in an emergency. [Background technology]

[0002] An in-vehicle battery has a current interruption device as one of its protective devices. If any abnormality is detected, the current interruption device opens to interrupt the current, thereby protecting the battery (see Patent Document 1).

[0003] One of the above-mentioned abnormalities is an external short circuit. When reusing a battery that has had its current interrupted due to an external short circuit, if the external short circuit continues, a large current may flow when the current interruption device is returned to the closed state. Patent Document 2 discloses a technology for determining whether or not there is a short-circuiting object that shorts between external terminals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-5985 A [Patent Document 2] WO2019 / 9292 publication Summary of the Invention [Problem to be solved by the invention]

[0005] When a vehicle crash occurs, the battery or other power storage device may be damaged more than expected. Therefore, when an abnormality occurs in the power storage device due to a vehicle crash, there is a concept of maintaining the current interruption even after the abnormality is resolved after the current interruption device is opened, in order to ensure the safety of the power storage device.

[0006] However, because the interruption of the current cuts off the power supply from the power storage device to the crashed vehicle, even if the vehicle is equipped with a post-crash function (post-collision safety function) such as an emergency call, it may not be possible to use the function. Even if the vehicle is not equipped with a post-crash function, it is desirable to secure power to execute emergency actions to ensure the safety of the vehicle, such as moving the vehicle to a safe place. One embodiment of the present invention discloses a technology for improving vehicle safety after a crash by prioritizing vehicle safety and resuming power supply to the vehicle when an abnormality occurs in a power storage device due to a crash and the abnormality is resolved. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided an electric storage device including an electric storage cell, a current interruption device that interrupts a current in the electric storage cell, and a control unit. When the control unit detects a vehicle crash and an abnormality in the electric storage device, the control unit opens the current interruption device to interrupt the current, and when the abnormality is no longer detected, the control unit closes the current interruption device to resume power supply to the crashed vehicle.

[0008] This technique may be implemented as a method for controlling a current interruption device. Effect of the Invention

[0009] According to the above aspect, even if an abnormality occurs in the power storage device along with a crash, once the abnormality is resolved, the safety of the vehicle is prioritized and the supply of power to the vehicle is resumed, thereby improving the safety of the vehicle after a crash. [Brief description of the drawings]

[0010] [Figure 1] Car side view [Diagram 2] Exploded perspective view of the battery [Diagram 3] Plan view of a secondary battery cell [Figure 4] Cross section of line AA in Figure 3 [Diagram 5] Block diagram showing the electrical configuration of a vehicle [Figure 6] Battery Block Diagram [Figure 7] Diagram showing the current path of a short circuit current [Figure 8] Diagram showing voltage change at point A [Figure 9] Power recovery process flowchart [Figure 10] Battery Block Diagram [Figure 11] Battery Block Diagram [Figure 12] Battery Block Diagram [Figure 13] Battery Block Diagram DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An overview of a power storage device according to an embodiment of the present invention will be described. The power storage device includes a power storage cell, a current interruption device that interrupts the current of the power storage cell, and a control unit. When the control unit detects a vehicle crash and an abnormality in the power storage device, the control unit opens the current interruption device to interrupt the current, and when the abnormality is no longer detected, the control unit closes the current interruption device to resume power supply to the crashed vehicle.

[0012] According to the above configuration, when a crash occurs and an abnormality occurs in the power storage device, the safety of the power storage device is first ensured by cutting off the current. After that, when the abnormal state of the power storage device is resolved, the current cut-off device is returned to the closed state and the supply of power to the vehicle is resumed.

[0013] Resumption of power supply enables the use of post-crash functions such as hazard lights and emergency call in the vehicle. Even if the vehicle does not have post-crash functions, resumption of power supply can ensure power for carrying out emergency actions to ensure the safety of the vehicle, such as moving the crashed vehicle to a safe place. Therefore, it is possible to improve the safety of the vehicle after a crash while protecting the power storage device.

[0014] The energy storage device may include a pair of external terminals electrically connected to the energy storage cells for connecting a vehicle load, and the abnormality may be a short circuit of the pair of external terminals due to a vehicle crash. In this configuration, the power storage device can be protected from an external short circuit caused by a vehicle crash, and when the external short circuit is resolved, the power supply to the crashed vehicle can be resumed. By interrupting the short circuit current, abnormal heat generation in current-carrying components such as bus bars and the power storage cells can be suppressed, and damage to the power storage device can be suppressed. Furthermore, by interrupting the short circuit current, a decrease in the discharge capacity of the power storage cells can be suppressed, making it easier to secure the power to be supplied to the crashed vehicle after the power supply is resumed.

[0015] The control unit may be communicatively connected to a vehicle ECU and share information regarding a vehicle crash with the vehicle ECU. In this configuration, when a vehicle crash occurs, a crash notification can be received from the vehicle ECU. When cutting off the current to the power storage device for protection after a vehicle crash occurs, information indicating that the current will be cut off can also be transmitted to the crashed vehicle prior to the cutoff.

[0016] The power storage device may have a built-in acceleration sensor, and the control unit may detect a vehicle crash based on a measurement value of the acceleration sensor. In this configuration, even if the communication line with the vehicle is disconnected due to the impact of the crash, the acceleration sensor built into the power storage device can detect the vehicle crash. Therefore, when the abnormality in the power storage device is resolved, the current interrupter can be returned to the closed state to resume the power supply to the crashed vehicle.

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. <Embodiment 1> 1. Battery 50A Description As shown in Fig. 1, automobile 10 is equipped with acceleration sensor 15, engine 20, and battery 50A used when starting engine 20, etc. In this embodiment, automobile 10 is equipped with only one battery 50A (a low-voltage battery such as 12V), but the vehicle may be equipped with multiple batteries. Alternatively, battery 50A may be a 12V battery that enables starting a high-voltage battery for driving the vehicle. Battery 50A is an example of an "electricity storage device."

[0018] 2, the battery 50A includes a battery pack 60, a circuit board unit 65, and a housing 71. The housing 71 includes a main body 73 and a lid 74 made of a synthetic resin material. The main body 73 is cylindrical with a bottom, and includes a bottom portion 75 and four side portions 76. The four side portions 76 form an opening 77 at the upper end of the main body 73.

[0019] The container 71 houses the battery pack 60 and the circuit board unit 65. The circuit board unit 65 is a board unit having various components (such as the current interruption device 53, the current detection unit 54 shown in FIG. 6, and the management device 110) mounted on a circuit board 100, and is disposed adjacent to, for example, above, the battery pack 60 as shown in FIG. 2. Alternatively, the circuit board unit 65 may be disposed adjacent to, a side of, the battery pack 60.

[0020] The lid 74 closes the opening 77 of the main body 73. An outer peripheral wall 78 is provided around the lid 74. The lid 74 has a protruding portion 79 that is generally T-shaped in plan view. A positive external terminal 51 is fixed to one corner of the front part of the lid 74, and a negative external terminal 52 is fixed to the other corner. The circuit board unit 65 may be housed in the lid 74 (for example, in the protruding portion 79) instead of in the main body 73 of the container 71.

[0021] The battery pack 60 is composed of a plurality of cells 62. As shown in Fig. 4, each cell 62 has an electrode body 83 housed in a rectangular (prismatic) case 82 together with a non-aqueous electrolyte. The cell 62 is, for example, a lithium ion secondary battery cell. The case 82 has a case body 84 and a lid 85 that closes the upper opening.

[0022] Although not shown in detail, the electrode body 83 is configured by disposing a separator made of a porous resin film between a negative electrode plate made of a copper foil substrate coated with an active material and a positive electrode plate made of an aluminum foil substrate coated with an active material. Both of these are strip-shaped, and are wound flatly so that they can be housed in the case body 84, with the negative electrode plate and the positive electrode plate being shifted to opposite sides in the width direction relative to the separator.

[0023] A positive electrode terminal 87 is connected to the positive electrode plate via a positive electrode collector 86, and a negative electrode terminal 89 is connected to the negative electrode plate via a negative electrode collector 88. The positive electrode collector 86 and the negative electrode collector 88 each have a flat base portion 90 and a leg portion 91 extending from the base portion 90. A through hole is formed in the base portion 90. The leg portion 91 is connected to the positive electrode plate or the negative electrode plate.

[0024] The positive electrode terminal 87 and the negative electrode terminal 89 each comprise a terminal body 92 and a shaft 93 that protrudes downward from the center of the lower surface of the terminal body 92. The terminal body 92 and shaft 93 of the positive electrode terminal 87 are integrally formed from aluminum (a single material). In the negative electrode terminal 89, the terminal body 92 is made of aluminum, and the shaft 93 is made of copper, and these are assembled together. The terminal body 92 of the positive electrode terminal 87 and the negative electrode terminal 89 are disposed on both ends of the lid 85 via gaskets 94 made of an insulating material, and are exposed to the outside from the gaskets 94 as shown in FIG. 3.

[0025] The lid 85 has a pressure relief valve 95. The pressure relief valve 95 is located between the positive electrode terminal 87 and the negative electrode terminal 89. The pressure relief valve 95 opens to reduce the internal pressure of the case 82 when the internal pressure of the case 82 exceeds a limit value.

[0026] FIG. 5 is a block diagram showing the electrical configuration of the automobile 10. As shown in FIG.

[0027] As shown in FIG. 5, the automobile 10 includes an engine 20 as a drive device, an engine control unit 21, an engine starting device 23, an alternator 25 as a vehicle generator, a vehicle load 27, a vehicle ECU (Electronic Control Unit) 30, a battery 50A, and the like.

[0028] The battery 50A is connected to a power supply line 37. The engine starting device 23, the alternator 25, and the vehicle load 27 are connected to the battery 50A via the power supply line 37.

[0029] The engine starting device 23 includes a starter motor. When the ignition switch 24 is turned on, a cranking current flows from the battery 50A to drive the engine starting device 23. The driving of the engine starting device 23 rotates the crankshaft, and the engine 20 can be started.

[0030] The vehicle load 27 indicates an electric load mounted on the automobile 10 other than the engine starting device 23. The vehicle load 27 has a rated voltage of 12 V, and examples of the vehicle load 27 include an air conditioner, an audio system, a car navigation system, and auxiliary equipment. The vehicle load 27 also includes the vehicle ECU 30.

[0031] The alternator 25 is a vehicle generator that generates electricity using the power of the engine 20. When the amount of electricity generated by the alternator 25 exceeds the amount of electricity consumed by the vehicle load 27, the battery 50A is charged by the alternator 25. When the amount of electricity generated by the alternator 25 is less than the amount of electricity consumed by the vehicle load 27, the battery 50A is discharged to make up for the shortage of electricity generated.

[0032] The vehicle ECU 30 is communicatively connected to the battery 50A via a communication line L1, and is communicatively connected to the alternator 25 via a communication line L2. The vehicle ECU 30 receives state of charge (SOC) information from the battery 50A, and controls the amount of power generation of the alternator 25, thereby controlling the SOC of the battery 50A.

[0033] The vehicle ECU 30 is communicatively connected to the engine control unit 21 via the communication line L3. The engine control unit 21 is mounted on the automobile 10, and monitors the operating state of the engine 20. The engine control unit 21 also monitors the running state of the automobile 10 from the measured values ​​of instruments such as a speedometer. The vehicle ECU 30 can obtain, from the engine control unit 21, information on the on / off state of the ignition switch 24, information on the operating state of the engine 20, and information on the running state of the automobile 10 (driving, stopped, idling stop, etc.).

[0034] 6 is a block diagram showing the electrical configuration of the battery 50 A. The battery 50 A includes a battery pack 60, a current interruption device 53, a current detection unit 54, a temperature sensor 55, and a management device 110.

[0035] The battery pack 60 has, for example, 12 cells 62 (see FIG. 2), three connected in parallel and four in series. In FIG. 6, three cells 62 connected in parallel are represented by one battery symbol. The cell 62 is an example of a "storage cell." The storage cell is not limited to a prismatic cell, and may be a cylindrical cell or a pouch cell having a laminated film case.

[0036] The battery pack 60, the current interruption device 53, and the current detection unit 54 are connected in series via power lines 58P and 58N. The power lines 58P and 58N can be bus bars BSB (see FIG. 2), which are plate-shaped conductors made of a metal material such as copper.

[0037] 6, a power line 58P connects the positive external terminal 51 and the positive electrode of the battery pack 60. A power line 58N connects the negative external terminal 52 and the negative electrode of the battery pack 60. The external terminals 51, 52 are terminals for connecting the battery 50A to the automobile 10 (vehicle load 27). The battery 50A can be electrically connected to the alternator 25 and the engine starting device 23 via the external terminals 51, 52.

[0038] The current interruption device 53 is provided on the positive power line 58P. The current interruption device 53 may be a semiconductor switch such as an FET or a relay having a mechanical contact, and is preferably a self-holding switch such as a latch relay. The current interruption device 53 is of a normally closed type and is normally controlled to a closed state. If an abnormality occurs in the battery 50A, the current I of the battery pack 60 can be interrupted by switching the current interruption device 53 from a closed state to an open state.

[0039] The current detection unit 54 is provided on the negative power line 58N. The current detection unit 54 measures the current I of the battery pack 60. The current detection unit 54 may be configured with a shunt resistor. The resistive current detection unit 54 can distinguish between discharging and charging from the polarity (positive or negative) of the voltage. Alternatively, the current detection unit 54 may be a magnetic sensor. The temperature sensor 55 is of a contact or non-contact type and measures the temperature [°C] of the battery pack 60 or its surroundings.

[0040] The management device 110 is mounted on a circuit board 100 (see FIG. 2), and includes a control unit 121, a memory 123, a voltage detection unit 130, and a voltage application circuit 150, as shown in FIG. 6. The management device 110 is connected to the positive electrode of the battery pack 60 by a power line L4, and operates using the battery pack 60 as a power source.

[0041] The voltage detection unit 130 is connected to both ends of each cell 62 by a signal line, and measures the cell voltage Vs of each cell 62. The voltage detection unit 130 also measures or calculates the total voltage Ev of the assembled battery 60 from the cell voltage Vs of each cell 62. The total voltage Ev of the assembled battery 60 is the sum of the voltages of the cells 62 connected in series.

[0042] The voltage application circuit 150 includes a current limiting resistor 151 and a switch 153. The current limiting resistor 151 and the switch 153 are connected in series. As the switch 153, a semiconductor switch such as an FET can be used.

[0043] One end of the voltage application circuit 150 is connected to the positive external terminal 51 (point A in FIG. 6; one side of the current interruption device 53), and the other end is connected to the positive electrode of the battery pack 60 (point B in FIG. 6; the other side of the current interruption device 53). In other words, the voltage application circuit 150 is connected in parallel to the current interruption device 53. By closing the switch 153, the voltage application circuit 150 can apply the positive voltage of the battery pack 60 to the positive external terminal 51, using the battery pack 60 as a power source.

[0044] The control unit 121 monitors the state of the battery 50A based on the outputs of the current detection unit 54, the voltage detection unit 130, and the temperature sensor 55. That is, the current I, the total voltage Ev, the cell voltage Vs, and the temperature of the battery pack 60 are monitored.

[0045] The memory 123 stores a monitoring program for monitoring the state of the battery 50A, a power recovery program in the event of a crash, and data required for executing these programs. The programs may be stored on a recording medium such as a CD-ROM and used, transferred, lent, etc. The programs may be distributed using electric communication lines.

[0046] The management device 110 is connected to the vehicle ECU 30 via a communication connector 125 and a communication line L1, and communicates with the vehicle ECU 30 by CAN communication or LIN communication. The management device 110 can receive information on the operation or non-operation of the engine 20, which is the drive device, from the vehicle ECU 30. The management device 110 can also receive information on the state of the automobile 10, such as whether the automobile is running, stopped, or parked. The communication connector 125 may be provided on the lid 74 (see FIG. 2).

[0047] Furthermore, the automobile 10 is equipped with an acceleration sensor 15 (see FIG. 1), and detects a crash of the automobile 10 from the measured acceleration. When the vehicle ECU 30 shown in FIG. 6 detects a crash of the automobile 10, it transmits a crash notification to the battery 50A through the communication line L1.

[0048] 2. External short circuit and power restoration following a vehicle crash The negative external terminal 52 of the battery 50A is connected to the body, which is the reference potential of the automobile 10. If the positive external terminal 51 comes into contact with the body due to the impact of a crash, the positive and negative external terminals 51, 52 may be short-circuited via the body (see FIG. 7).

[0049] The short-circuit current Is that flows at this time can be a large current of several thousand A, and if this current continues to flow, the battery pack 60, bus bars, and other current-carrying components will overheat, making it difficult to ensure safety. Therefore, when the short-circuit current Is that exceeds the threshold flows, the control unit 121 opens the current interruption device 53 to interrupt the current. This makes it possible to ensure the safety of the battery 50A.

[0050] In the event of a crash, the battery 50A may have sustained more damage than expected. Therefore, after the current is once cut off, even if the abnormal event such as an external short circuit is eliminated, the current cutoff is maintained to ensure the safety of the battery 50A.

[0051] However, if the current interruption is maintained, the power supply to the automobile 10 (the vehicle load 27 and the vehicle ECU 30 shown in FIG. 5) will be cut off. Therefore, even if the vehicle is equipped with post-crash functions such as hazard lights and an emergency call, these functions cannot be used. This problem becomes more pronounced in particular when the automobile 10 is not equipped with a power source other than the battery 50A.

[0052] Therefore, in this embodiment, if an external short circuit occurs due to a crash of the automobile 10, the current is interrupted by opening the current interruption device 53. After that, if the external short circuit is resolved, the current interruption device 53 is returned to the closed state, and the power supply to the automobile 10 is resumed.

[0053] In this way, the safety of the vehicle 10 can be improved since post-crash functions are available after a crash.

[0054] The elimination of the external short circuit can be determined, for example, by the following steps: When an external short circuit is detected, current interruption device 53 is opened to interrupt the short circuit current Is, and then switch 153 of voltage application circuit 150 is closed to apply a voltage to positive external terminal 51 (see FIG. 7). Control unit 121 detects the voltage at point A measured at that time via signal line L5.

[0055] If the external short circuit continues after the current is cut off, the voltage at point A is "zero V" as shown in Fig. 8. If the external short circuit is eliminated and also cut off from the vehicle load 27, the voltage at point A is the "total voltage Ev" of the battery pack 60. Therefore, it is possible to determine whether the external short circuit has been eliminated from the measured voltage at point A.

[0056] 3. Explanation of power restoration process 9 is a flowchart of the power restoration process. The power restoration process is made up of five steps S10 to S50, and is performed at a predetermined interval while the management device 110 is running, in parallel with monitoring the state of the battery 50A.

[0057] When starting the power restoration process, the control unit 121 first determines whether or not a crash has occurred in the automobile 10 (S10).

[0058] The occurrence of a vehicle crash can be determined based on whether or not a crash notification has been received from the vehicle ECU 30. If no accident has occurred in the automobile 10, the vehicle ECU 30 will not transmit a crash notification to the battery 50A. Therefore, it is determined that no vehicle crash has occurred, and the standby state is entered (S10: NO).

[0059] When an accident occurs in the automobile 10, the acceleration sensor 15 detects an acceleration exceeding a predetermined value, which causes the vehicle ECU 30 to detect a crash.

[0060] When a crash is detected, a crash notification is transmitted from the vehicle ECU 30 to the battery 50A, and the crash notification is received by the control unit 121. By receiving the crash notification, the control unit 121 is able to share information about the vehicle crash with the vehicle ECU 30, and determines that a vehicle crash has occurred (S10: YES).

[0061] Thereafter, the control unit 121 determines whether or not there is an abnormality in the battery 50A (S20). In this embodiment, the presence or absence of an external short circuit is detected based on the current I of the battery pack 60. When the two external terminals 51, 52 are short-circuited due to the impact of a vehicle crash, such as when the positive external terminal 51 comes into contact with the body, the battery pack 60 discharges a short-circuit current Is that exceeds a threshold value.

[0062] When the short-circuit current Is exceeding the threshold value is measured by the current detection unit 54, the control unit 121 determines that an external short circuit has occurred (S20: YES).

[0063] When the control unit 121 detects an abnormality (external short circuit), it issues a command to the current interruption device 53 to switch the current interruption device 53 from a closed state to an open state (S30). When the current interruption device 53 is opened, the short-circuit current Is is interrupted.

[0064] After the short-circuit current Is is cut off, the control unit 121 determines whether the abnormality (external short circuit) has been eliminated (S40). The elimination of the external short circuit can be determined by applying a voltage to the positive external terminal 51 using the voltage application circuit 150 and judging from the voltage at point A measured at that time.

[0065] When the control unit 121 determines that the abnormality (external short circuit) has not been eliminated (S40: NO), it maintains the current interruption device 53 in the open state.

[0066] When the control unit 121 determines that the abnormality (external short circuit) has been resolved (S40: YES), it returns the current interruption device 53 to the closed state (S50). As a result, the power supply to the crashed automobile 10 is automatically resumed.

[0067] 4.Effects According to this embodiment, even if an abnormality such as an external short circuit temporarily occurs in the battery 50A due to a crash of the automobile 10, once the abnormality is resolved, the power supply to the crashed automobile 10 is automatically resumed. This makes it possible to use post-crash functions such as hazard lights and emergency calls. Even if the automobile 10 does not have a post-crash function, for example, if the automobile 10 is capable of running after a crash, the crashed automobile 10 can be moved to a safe place. As a result, it is possible to improve the safety of the automobile 10 after a crash.

[0068] One method of restoring an open current interruption device 53 is to apply a voltage to the external terminals 51, 52 of the battery 50A by a device external to the battery 50A. However, this method requires the driver of the automobile 10 to carry an external charger or the like close to the battery 50A and connect it to the external terminals 51, 52, and takes time to restore. According to this embodiment, the current interruption device 53 can be automatically restored after the external short circuit is eliminated, and the time until restoration can be shortened.

[0069] <Embodiment 2> As shown in FIG. 10, the battery 50B of the second embodiment differs from the battery 50A of the first embodiment in that an acceleration sensor 127 is built in.

[0070] Battery 50B measures acceleration using built-in acceleration sensor 127 and autonomously detects a crash of automobile 10. For example, when the battery 50B measures acceleration exceeding a predetermined value, it determines that automobile 10 has crashed.

[0071] Even if communication with the vehicle ECU 30 is interrupted due to a line break caused by a crash of the automobile 10, the battery 50B of the second embodiment can autonomously detect the crash of the automobile 10 using the built-in acceleration sensor 127 and execute the power recovery process shown in Fig. 9. Therefore, even if an abnormality such as an external short circuit occurs in the battery 50B due to the crash, the power supply to the automobile 10 is automatically resumed once the abnormality is resolved. The safety of the automobile 10 after a crash can be improved without relying on the function of the vehicle ECU 30.

[0072] <Embodiment 3> 11, the battery 50C of the third embodiment is different from the battery 50A of the first embodiment in the configuration of the voltage application circuit 150. The voltage application circuit 160 of the third embodiment has a capacitor 161, a switch 163, and a discharge resistor 165.

[0073] Capacitor 161 and switch 163 are connected in series. Capacitor 161 is connected to point A in Fig. 11, and switch 163 is connected to point B in Fig. 11, and are connected in parallel to current interruption device 53. Discharge resistor 165 has one end connected to intermediate connection point E between capacitor 161 and switch 163, and the other end connected to ground.

[0074] The discharge resistor 165 serves to discharge the charge stored in the capacitor 161 when the switch 163 is turned off.

[0075] In the battery 50C shown in FIG. 11, by turning on the switch 163 of the voltage application circuit 160, the voltage of the positive electrode of the battery pack 60 can be applied to the positive external terminal 51 (point A) using the battery pack 60 as a power source.

[0076] Therefore, similarly to embodiment 1, after the current interruption device is opened to interrupt the current upon detection of an external short circuit, a voltage is applied by the voltage application circuit 160, and the elimination of the external short circuit can be determined from the voltage at point A measured at that time.

[0077] <Embodiment 4> 12, the battery 50D of the fourth embodiment differs from the battery 50A of the first embodiment in that it does not include the voltage application circuit 150. The battery 50D of the fourth embodiment determines whether an external short circuit has been eliminated based on the current I of the battery pack 60.

[0078] When the control unit 121 detects an external short circuit of the battery 50D, it opens the current interruption device 53 to interrupt the short circuit current Is, similarly to the first to third embodiments. The control unit 121 closes the current interruption device 53 several seconds to several tens of seconds after the short circuit current Is is interrupted, and measures the current value at that time by the current detection unit 54.

[0079] If the current measurement value is equal to or greater than the threshold, it can be determined that the external short circuit continues, and if it is less than the threshold, it can be determined that the external short circuit has been resolved. By repeatedly performing this determination of the current measurement value at intervals of several seconds to several tens of seconds, rather than just once after the current is interrupted, it is possible to detect the point at which the external short circuit has been resolved.

[0080] In this configuration, even without the voltage application circuit 150 and the voltage application circuit 160, it is possible to determine whether or not an external short circuit has been eliminated, and the circuitry can be simplified.

[0081] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention.

[0082] (1) The cell 62 is not limited to a lithium ion secondary battery, but may be another nonaqueous electrolyte secondary battery or a lead storage battery. The cell 62 is not limited to a case where a plurality of cells are connected in series in parallel, but may be a plurality of cells connected in series, or may be a single cell. A capacitor may be used as the storage cell instead of the secondary battery cell 62. The secondary battery cell and the capacitor are examples of the storage cell.

[0083] (2) In the first to fourth embodiments, the battery is for an automobile. The battery is not limited to an automobile (four-wheeled vehicle) and may be for a motorcycle. In other words, the battery can be used for vehicles such as an automobile or a motorcycle.

[0084] (3) In the first embodiment, the present technology has been described by taking as an example a case where an abnormality in the battery 50A is detected after a vehicle crash is detected. The order of detection of the vehicle crash and detection of the battery abnormality may be reversed, and the present technology can also be applied to a case where a battery abnormality is detected first, the current interruption device 53 is opened, and then a crash is detected by a built-in acceleration sensor or the like. In other words, the present technology can be applied if an abnormality occurs in the battery together with a vehicle crash.

[0085] (4) In the first to fourth embodiments, when the battery 50 is subjected to an external short circuit due to a crash of the automobile 10, the current is temporarily cut off to protect the battery 50. When the external short circuit is subsequently eliminated, the current cut-off device 53 is returned to the closed state, and the power supply to the crashed automobile 10 is resumed. This technique can be applied not only to an external short circuit, but also to cases where other abnormalities occur in the battery 50.

[0086] (5) In the first embodiment, when the acceleration sensor 15 mounted on the automobile detects a vehicle crash, the vehicle ECU 30 transmits a "crash notification" to the battery 50A. When the current interruption device 53 is opened to interrupt the current to protect the battery after the occurrence of a vehicle crash, the battery 50A may transmit "current interruption information" to the vehicle ECU 30 prior to the interruption, thereby sharing the "current interruption information" with the vehicle ECU 30. By transmitting the "current interruption information" from the battery 50A to the vehicle ECU 30 in advance, the driver can select an emergency action on the assumption that the current will be interrupted.

[0087] (6) When the battery receives a crash notification from the vehicle ECU 30, it may receive not only information on whether or not a crash has occurred, but also information on the severity of the crash, the amount of power required to ensure the safety of the vehicle, etc. In this case, the control unit 121 may change the criteria for returning the current interruption device 53 from the open state to the closed state based on the obtained information.

[0088] For example, if the crash is minor and the urgency is low, the first judgment criterion is selected to wait for confirmation of the battery's safety before resuming the power supply. If the crash is serious and the urgency is high, the confirmation of the battery's safety is kept to a minimum, and the second judgment criterion is selected, which enables earlier resumption of the power supply to the crashed vehicle than the first judgment criterion. A specific example of the first and second judgment criterion is changing the length of the predetermined time when controlling the current interruption device to return from the open state to the closed state on the condition that the abnormality is resolved for a predetermined time. In other words, compared to the first judgment criterion, the second judgment criterion shortens the predetermined time, thereby enabling earlier resumption of the power supply to the crashed vehicle.

[0089] (7) In the first embodiment, the current interruption device 53 is disposed at the positive electrode of the battery pack 60, and the current detection unit 54 is disposed at the negative electrode of the battery pack. As shown in FIG. 13, the current detection unit 54 may be disposed at the positive electrode, and the current interruption device 53 may be disposed at the negative electrode. In this case, the voltage application circuit 150 applies the voltage of the negative electrode of the battery pack 60 to point C and measures the voltage, thereby making it possible to determine the state of the battery 50E. During an external short circuit, the voltage at point C becomes equal to the voltage Ev of the positive electrode of the battery pack 60. When the external short circuit is eliminated, if the battery 50E is disconnected from the vehicle load 27, the voltage at point C becomes equal to the voltage 0V of the negative electrode of the battery pack 60. Therefore, it is possible to determine whether the external short circuit has been eliminated from the voltage at point C.

[0090] (8) In the first embodiment, it is assumed that the battery 50 is disconnected from the vehicle load 27, and therefore it has been described that when a voltage is applied using the voltage application circuit 150 after current interruption, if the external short circuit is eliminated, the voltage at point A is equal to the total voltage Ev of the battery pack 60. If the battery 50 is not disconnected from the vehicle load 27, the voltage at point A is a voltage Ev×K obtained by multiplying the total voltage Ev of the battery pack 60 by a voltage division ratio K. The voltage division ratio is the resistance ratio between the current limiting resistor 151 of the voltage application circuit 150 and the vehicle load 27.

[0091] As described above, the voltage measured at point A differs depending on the state of vehicle load 27, but the fact that the voltage at point A changes whether the external short circuit continues or has been resolved is common regardless of whether vehicle load 27 is disconnected or not. Therefore, even if vehicle load 27 is not disconnected, it is possible to determine whether the external short circuit has been resolved from the voltage at point A. [Explanation of symbols]

[0092] 10 Automobiles 10 30 Vehicle ECU (Vehicle Control Unit) 50A~50E Battery (energy storage device) 53 Current interrupter 54 Current detection section 60 Battery pack 110 Management device 121 Control Unit

Claims

1. A power storage device mounted on a vehicle, comprising: A storage cell; A current interruption device that interrupts a current in the storage cell; A control unit provided in the power storage device, The control unit is When a vehicle crash is detected and an abnormality in the power storage device is detected, the current interruption device is opened to interrupt the current; When the abnormality is no longer detected, the power storage device closes the current interruption device to resume power supply to the crashed vehicle.

2. The power storage device according to claim 1 , A power storage device that, upon resumption of power supply, provides power for post-crash functions of the vehicle or power to perform emergency actions of the vehicle.

3. The power storage device according to claim 1 or 2, a pair of external terminals electrically connected to the storage cell for connecting a vehicle load; The abnormality is a short circuit between the pair of external terminals caused by a vehicle crash.

4. The power storage device according to any one of claims 1 to 3, The control unit is connected to a vehicle ECU via communication, A power storage device that shares information regarding a vehicle crash with the vehicle ECU.

5. The power storage device according to any one of claims 1 to 3, Equipped with an acceleration sensor, The control unit detects a vehicle crash based on a measurement value of the acceleration sensor.

6. A method for controlling a current interruption device of an electric storage device mounted on a vehicle, comprising: If a vehicle crash occurs and an abnormality in the power storage device is detected, the current interruption device is opened to cut off the current, A control method for a current interruption device, the control method including, when a control unit provided in the power storage device determines that the abnormality is no longer detected, closing the current interruption device to resume power supply to the crashed vehicle.

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