Blocking device

Abstract

A blocking device (100) comprises: a blocking control unit (10) that controls a blocking unit (40) for blocking the current from a battery (200); a first current detection unit (21) that detects the current flowing through a first current path (P1) connecting the blocking unit (40) and a first load (301); a second current detection unit (22) that detects the current flowing through a second current path (P2) connected in parallel with the first current path (P1) and connecting the blocking unit (40) and a second load (302); and a measurement unit (30) for measuring the current flowing through the first current path (P1), the current flowing through the second current path (P2), and the voltage of the battery (200). The blocking control unit (10) controls the blocking unit (40) on the basis of the measured current flowing through one of the first current path (P1) and the second current path (P2) and the measured voltage of the battery (200).

Description

Circuit breaker

[0001] The present disclosure relates to a circuit breaker that interrupts a large current that flows in a current path when an abnormality occurs.

[0002] Patent Document 1 discloses a technique for detecting a short circuit by detecting voltages at a plurality of locations.

[0003] U.S. Patent No. 9,257,729

[0004] It is conceivable to use the technology disclosed in Patent Document 1 to increase the redundancy of abnormality detection by determining whether or not an abnormality such as a short circuit has occurred in each of multiple current paths from the battery to multiple loads. However, if an abnormality is detected in any of the multiple current paths and the current from the battery is cut off, the current to all of the multiple loads will be cut off, so it is important to prevent current cut-off due to erroneous detection.

[0005] Therefore, the present disclosure provides a circuit breaker that can increase the redundancy of abnormality detection and suppress current interruption due to erroneous detection.

[0006] The interrupting device of the present disclosure comprises an interrupting control unit that controls an interrupting unit for interrupting current from a battery, a first current detection unit that detects current flowing in a first current path connecting the interrupting unit and a first load, a second current detection unit that detects current flowing in a second current path that connects the interrupting unit and a second load and is connected in parallel to the first current path, and a measurement unit that measures the current flowing in the first current path, the current flowing in the second current path, and the voltage of the battery, and the interrupting control unit controls the interrupting unit based on the measured current flowing in one of the first current path and the second current path, and the voltage of the battery.

[0007] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to an aspect of the present disclosure, the interruption device can increase the redundancy of abnormality detection and prevent current interruption due to erroneous detection.

[0009] Fig. 1 is a block diagram showing an example of an interrupter according to embodiment 1. Fig. 2 is a cross-sectional view showing an example of a pyrofuse. Fig. 3 is a circuit configuration diagram showing an example of an interrupter according to embodiment 1. Fig. 4 is a diagram showing an example of a battery voltage and currents flowing in a first current path and a second current path when an overcurrent flows. Fig. 5 is a block diagram showing an example of an interrupter according to embodiment 2. Fig. 6 is a block diagram showing an example of an interrupter according to embodiment 3.

[0010] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0011] The embodiments described below are all comprehensive or specific examples, and the numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0012] (First embodiment) Hereinafter, a circuit breaking device according to a first embodiment will be described.

[0013] Fig. 1 is a block diagram showing an example of a circuit breaker 100 according to embodiment 1. In Fig. 1, in addition to the circuit breaker 100, a battery 200 and loads 301 and 302 are also shown.

[0014] The interrupter 100 is mounted on a vehicle such as an electric vehicle that uses electric power for propulsion. A high-voltage battery is mounted on the vehicle such as an electric vehicle as a battery 200, and power is supplied from the battery 200 to various drive loads such as a motor and an inverter, thereby propelling the vehicle such as an electric vehicle. Note that although two loads 301 and 302 are shown here as an example, power may be supplied to three or more loads.

[0015] When an accident or the like occurs, a large current due to an abnormality such as a short circuit may flow in the current path connecting battery 200 and loads 301 and 302, which may cause the vehicle to smoke or catch fire. For this reason, interrupter 100 is provided in the vehicle to interrupt the current path (specifically, to interrupt the large current that flows in the current path when an abnormality occurs).

[0016] For this reason, as will be described later, it is more preferable that the interrupting section 40 provided in the interrupting device 100 is a pyrotechnic fuse (pyrotechnic circuit breaker, irreversible pyrotechnic circuit breaker) that can instantly interrupt a large current in the event of an abnormality.

[0017] The interruption device 100 includes an interruption control unit 10, current detection units 21 and 22, a measurement unit 30, and an interruption unit 40. Note that, as an example, two loads 301 and 302 are shown here, and therefore two current detection units 21 and 22 are shown, but three or more current detection units may be provided for three or more loads.

[0018] The interrupter 40 is a component for interrupting the current from the battery 200. The interrupter 40 is an active fuse that is interrupted based on a signal from the interruption control unit 10 to cut off the current path connecting the battery 200 and the loads 301 and 302 when a large current due to a short circuit flows through the current path. For example, the interrupter 40 is inserted into the current path connecting the positive side of the battery 200 and the loads 301 and 302 (specifically, the path before branching to the loads 301 and 302) so as to be part of the current path. The interrupter 40 interrupts the current path based on a signal from the interruption control unit 10 (specifically, cuts off a bus bar or the like that constitutes the current path). Note that the interrupter device 100 does not necessarily have to include the interrupter 40, and the interrupter 40 may be a component external to the interrupter device 100.

[0019] An example of an active fuse is a pyrotechnic circuit breaker (irreversible pyrotechnic circuit breaker).

[0020] FIG. 2 is a cross-sectional view showing an example of the pyrofuse 41. As shown in FIG.

[0021] As shown in Figure 2, pyrofuse 41 has a casing portion 201 that forms the outer shell of pyrofuse 41, a piston 203, an ignition portion 202 that activates piston 203, and a bus bar 204 that is inserted into the current path and becomes part of the current path.

[0022] The current detection unit 21 detects a current flowing in a current path P1 connecting the interrupter 40 and the load 301. The current detection unit 21 is an example of a first current detection unit, the load 301 is an example of a first load, and the current path P1 is an example of a first current path. In the first embodiment, the current detection unit 21 is connected between the interrupter 40 and the load 301 in the current path P1. Details of the current detection unit 21 will be described later.

[0023] The current detection unit 22 detects a current flowing through a current path P2 that connects the interrupter 40 and the load 302 and is connected in parallel to the current path P1. The current detection unit 22 is an example of a second current detection unit, the load 302 is an example of a second load, and the current path P2 is an example of a second current path. In the first embodiment, the current detection unit 22 is connected between the interrupter 40 and the load 302 in the current path P2. Details of the current detection unit 22 will be described later.

[0024] Note that, as an example, two loads 301 and 302 are shown here, and therefore two current paths P1 and P2 are shown, but three or more current paths connected in parallel may be provided for three or more loads.

[0025] The measurement unit 30 measures the current flowing through the current path P1, the current flowing through the current path P2, and the voltage of the battery 200. Details of the measurement unit 30 will be described later.

[0026] The cutoff control unit 10 controls the cutoff unit 40. Specifically, the cutoff control unit 10 controls the cutoff unit 40 based on the current flowing through one of the current paths P1 and P2 and the voltage of the battery 200, which are measured by the measurement unit 30. That is, the cutoff control unit 10 controls the cutoff unit 40 using not only the measurement result of the current flowing through one of the current paths P1 and P2, but also the measurement result of the voltage of the battery 200. The cutoff control unit 10 will be described in detail later. The cutoff control unit 10 is realized by, for example, a microcomputer (MCU: Micro Controller Unit) or the like.

[0027] FIG. 3 is a circuit configuration diagram showing an example of the circuit breaker 100 according to the first embodiment.

[0028] For example, the current detection unit 21 has a shunt resistor R1 provided in the current path P1, and the current detection unit 22 has a shunt resistor R2 provided in the current path P2. The shunt resistor R1 is an example of a first shunt resistor, and the shunt resistor R2 is an example of a second shunt resistor. By using the shunt resistors R1 and R2, it is possible to detect the currents flowing through the current paths P1 and P2.

[0029] The measurement unit 30 includes voltage follower circuits 31, 32, 33, and 34 and differential amplifier circuits 35 and 36.

[0030] The positive input terminal of the voltage follower circuit 31 is connected to the terminal of the shunt resistor R1 on the cutoff unit 40 side, the negative input terminal of the voltage follower circuit 31 is connected to ground (the negative side of the battery 200), and the output terminal of the voltage follower circuit 31 is connected to the cutoff control unit 10 and the positive input terminal of the differential amplifier circuit 35.

[0031] The positive input terminal of the voltage follower circuit 32 is connected to the terminal of the shunt resistor R1 on the load 301 side, the negative input terminal of the voltage follower circuit 32 is connected to ground, and the output terminal of the voltage follower circuit 32 is connected to the negative input terminal of the differential amplifier circuit 35.

[0032] The positive input terminal of the voltage follower circuit 33 is connected to the terminal of the shunt resistor R2 on the cutoff unit 40 side, the negative input terminal of the voltage follower circuit 33 is connected to ground, and the output terminal of the voltage follower circuit 33 is connected to the cutoff control unit 10 and the positive input terminal of the differential amplifier circuit 36.

[0033] The positive input terminal of the voltage follower circuit 34 is connected to the terminal of the shunt resistor R2 on the load 302 side, the negative input terminal of the voltage follower circuit 34 is connected to ground, and the output terminal of the voltage follower circuit 34 is connected to the negative input terminal of the differential amplifier circuit 36.

[0034] The positive input terminal of the differential amplifier circuit 35 is connected to the output terminal of the voltage follower circuit 31, the negative input terminal of the differential amplifier circuit 35 is connected to the output terminal of the voltage follower circuit 32, and the output terminal of the differential amplifier circuit 35 is connected to the cut-off control unit 10.

[0035] The positive input terminal of the differential amplifier circuit 36 ​​is connected to the output terminal of the voltage follower circuit 33, the negative input terminal of the differential amplifier circuit 36 ​​is connected to the output terminal of the voltage follower circuit 34, and the output terminal of the differential amplifier circuit 36 ​​is connected to the cut-off control unit 10.

[0036] With the above circuit configuration, the measurement unit 30 measures the voltage at the terminal of the shunt resistor R1 on the cutoff unit 40 side and the voltage at the terminal of the shunt resistor R2 on the cutoff unit 40 side as the voltage of the battery 200. This is because the voltage at the terminal of the shunt resistor R1 on the cutoff unit 40 side and the terminal of the shunt resistor R2 on the cutoff unit 40 side are each connected to the battery 200 via the cutoff unit 40, and the voltages at these terminals are approximately the same potential as the voltage of the battery 200. Furthermore, because the output terminals of the voltage follower circuits 31 and 33 are directly connected to the cutoff control unit 10, the measurement unit 30 can notify the cutoff control unit 10 of the measured voltage at the terminal of the shunt resistor R1 on the cutoff unit 40 side and the voltage at the terminal of the shunt resistor R2 on the cutoff unit 40 side, i.e., the voltage of the battery 200. Therefore, the cutoff control unit 10 can control the cutoff unit 40 based on the measured voltage of the battery 200.

[0037] Furthermore, with the above circuit configuration, the measurement unit 30 measures the voltage between the terminal of the shunt resistor R1 on the cutoff unit 40 side and the terminal of the shunt resistor R1 on the load 301 side as the current flowing through the current path P1. This is because a voltage corresponding to the current flowing through the current path P1 is generated across the shunt resistor R1. Note that the resistance value of the shunt resistor R1 is very small, and the voltage generated across the shunt resistor R1 can also be small. Therefore, the voltage is differentially amplified by the differential amplifier circuit 35 and notified to the cutoff control unit 10. This allows the cutoff control unit 10 to control the cutoff unit 40 based on the measured current flowing through the current path P1 (specifically, the voltage corresponding to the current).

[0038] Furthermore, the measurement unit 30 measures the voltage between the terminal of the shunt resistor R2 on the cutoff unit 40 side and the terminal of the shunt resistor R2 on the load 302 side as the current flowing through the current path P2. This is because a voltage corresponding to the current flowing through the current path P2 is generated across the shunt resistor R2. Note that the resistance value of the shunt resistor R2 is very small, and the voltage generated across the shunt resistor R2 can also be small. Therefore, the voltage is differentially amplified by the differential amplifier circuit 36 ​​and notified to the cutoff control unit 10. This allows the cutoff control unit 10 to control the cutoff unit 40 based on the measured current flowing through the current path P2 (specifically, the voltage corresponding to the current).

[0039] In this way, the currents flowing through the current paths P1 and P2 can be measured from the voltages across the shunt resistors R1 and R2.

[0040] The measuring unit 30 measures the voltage via the voltage follower circuits 31, 32, 33 and 34, and the voltage can be accurately measured by the impedance conversion performed by the voltage follower circuits 31, 32, 33 and 34.

[0041] For example, when communication data indicating the current detected by the current detection unit 21 is notified from the measurement unit 30 to the cutoff control unit 10, this communication data contains only a sign bit, and it is difficult to verify the authenticity of this communication data from this communication data alone. In other words, even if an overcurrent is measured, there is a possibility that the overcurrent detection is a false detection.

[0042] Therefore, as described above, the cutoff control unit 10 controls the cutoff unit 40 using not only the measurement result of the current flowing through one of the current paths P1 and P2, but also the measurement result of the voltage of the battery 200.

[0043] For example, the cutoff control unit 10 controls the cutoff unit 40 based on the measured current flowing through one of the current paths P1 and P2 and the voltage at the terminal of the shunt resistor R1 or R2, which is provided in the other of the current paths P1 and P2, that is on the cutoff unit 40 side. For example, when an overcurrent is measured in the current path P1, the cutoff control unit 10 controls the cutoff unit 40 based on the current flowing through the current path P1 and the voltage at the terminal of the shunt resistor R2, which is provided in the current path P2, that is on the cutoff unit 40 side. For example, when the current flowing through one of the current paths is equal to or greater than a predetermined current value and the voltage of the battery 200 is equal to or less than a predetermined voltage, the cutoff control unit 10 controls the cutoff unit 40 to cut off the current from the battery 200. As will be described later, an overcurrent causes the voltage of battery 200 to drop, so if an overcurrent is measured in one current path and a drop in the voltage of battery 200 is measured, it is possible to determine that the overcurrent detection was normal and cut off the current from battery 200.

[0044] Furthermore, even if the current flowing through one current path is equal to or greater than a predetermined current value, if the voltage of the battery 200 is not equal to or less than a predetermined voltage, the cutoff control unit 10 does not control the cutoff unit 40 and does not cut off the current from the battery 200. As will be described later, this is because, since the voltage of the battery 200 does not drop even though an overcurrent has been measured, it can be determined that the detection of the overcurrent was an erroneous detection.

[0045] The predetermined current value is not particularly limited, but may be set, for example, according to the current value at which the current path should be interrupted. The predetermined voltage is not particularly limited, but may be set, for example, to a low voltage that is not generated during normal use of the battery 200.

[0046] As described above, the circuit breaker 100 is equipped with a current detection unit 21 that detects the current flowing through current path P1 and a current detection unit 22 that detects the current flowing through current path P2, thereby increasing the redundancy of abnormality detection.

[0047] Furthermore, when an overcurrent is detected in one of the current paths P1 and P2, if the detection of this overcurrent is normal, a large current will flow from the battery 200, causing the voltage of the battery 200 to drop.

[0048] 4 is a diagram showing an example of the voltage of battery 200 and the currents flowing through current paths P1 and P2 when an overcurrent flows. The first current shown in FIG. 4 indicates the current flowing through current path P1, and the second current indicates the current flowing through current path P2. As shown in FIG. 4, for example, when an overcurrent flows through current path P1, it can be seen that the voltage of battery 200 drops.

[0049] On the other hand, if the detection of the overcurrent is a false detection, a large current is not actually flowing from the battery 200, and therefore the voltage of the battery 200 does not drop. Therefore, if an overcurrent is measured in one current path but a drop in the voltage of the battery 200 is not measured, it is possible to determine that the detection of the overcurrent was a false detection and not to cut off the current from the battery 200. This increases the redundancy of abnormality detection and prevents current cut-off due to false detection.

[0050] 3, when each shunt resistor is connected between the cutoff unit 40 and the load, the voltage at the terminal of each shunt resistor on the cutoff unit 40 side becomes the voltage of the battery 200. Therefore, when an overcurrent is measured in one current path, if a voltage drop is not measured at the terminal on the cutoff unit 40 side of the shunt resistor provided in the other current path, it is possible to determine that the detection of the overcurrent was a false detection and not cut off the current from the battery 200.

[0051] As shown in FIG. 4 , it can be seen that the current flowing through current path P2 also changes (here, it has become smaller). This is because the current flowing through current path P2 also decreases as the voltage of battery 200 drops. Therefore, cutoff control unit 10 may control cutoff unit 40 based on the measured current flowing through one current path, the voltage of battery 200, and the current flowing through the other current path. If an overcurrent flows through one current path, the current flowing through the other current path also changes due to a drop in the voltage of battery 200, etc. Therefore, by using the measured current flowing through one current path and the voltage of battery 200, as well as the measured current flowing through the other current path, it is possible to accurately control cutoff unit 40. For example, if an overcurrent is measured in one current path, the voltage of battery 200 drops, and it is measured that the current flowing through the other current path has changed by a predetermined amount (e.g., decreased by a predetermined amount), it is possible to cut off the current from battery 200, assuming that the overcurrent detection was normal.

[0052] Second Embodiment Next, a circuit breaking device according to a second embodiment will be described.

[0053] Fig. 5 is a block diagram showing an example of a circuit breaker 100a according to embodiment 2. In Fig. 5, a battery 200 and loads 301 and 302 are also shown in addition to the circuit breaker 100a.

[0054] The circuit breaker 100a according to the second embodiment differs from the circuit breaker 100 according to the first embodiment in the following respects. The other points are basically the same as those in the first embodiment, and therefore description thereof will be omitted.

[0055] Current detection unit 21 is connected between load 301 and the negative side of battery 200, and current detection unit 22 is connected between load 302 and the negative side of battery 200. In the second embodiment, current detection units 21 and 22 are connected to breaker unit 40 and ultimately to the positive side of battery 200 via loads 301 and 302, and therefore the voltages at the terminals of current detection units 21 and 22 (shunt resistors R1 and R2) on the breaker unit 40 side are not at the same potential as the voltage of battery 200.

[0056] Therefore, the measuring unit 30 measures the voltage between the positive side of the battery 200 (specifically, a node in the path connecting the cut-off unit 40 and the load 301 or 302) and the negative side of the battery 200 (specifically, a node in the path connecting the negative side of the battery 200 and the current detection unit 21 or 22) as the voltage of the battery 200.

[0057] Furthermore, the measurement unit 30 measures, as the current flowing through current path P1, the voltage between the terminal of the current detection unit 21 (shunt resistor R1) on the load 301 side and the negative terminal of the current detection unit 21 (shunt resistor R1) on the battery 200. Furthermore, the measurement unit 30 measures, as the current flowing through current path P2, the voltage between the terminal of the current detection unit 22 (shunt resistor R2) on the load 302 side and the negative terminal of the current detection unit 22 (shunt resistor R2) on the battery 200.

[0058] In this way, shunt resistors R1 and R2 may be connected between loads 301 and 302 and the negative side of battery 200. In this case, too, it is possible to measure the voltage of battery 200 and the current flowing through current paths P1 and P2. Therefore, it is possible to control circuit breaker 40 based on the current flowing through one of current paths P1 and P2 and the voltage of battery 200, thereby increasing the redundancy of abnormality detection and suppressing current interruption due to erroneous detection.

[0059] Third Embodiment Next, a circuit breaking device according to a third embodiment will be described.

[0060] Fig. 6 is a block diagram showing an example of a circuit breaker 100b according to embodiment 3. In Fig. 6, a battery 200 and loads 301 and 302 are also shown in addition to the circuit breaker 100b.

[0061] The interrupting device 100b according to the third embodiment differs from the interrupting device 100 according to the first embodiment in the following respects. The other points are basically the same as those in the first embodiment, and therefore description thereof will be omitted. Note that, as in the second embodiment, the measuring unit 30 measures the voltage between the positive side of the battery 200 and the negative side of the battery 200 as the voltage of the battery 200.

[0062] The current detection unit 21 detects the current flowing through the current path P1 using a coil or a Hall element, and the current detection unit 22 detects the current flowing through the current path P2 using a coil or a Hall element. In this way, by using the coil or the Hall element, the currents flowing through the current paths P1 and P2 can be detected in a non-contact manner.

[0063] For example, if an overcurrent flows through current path P1, a large magnetic field is generated around current path P1 through which the overcurrent flows, affecting the coil or Hall element of current detection unit 22 and changing the current detection result of current detection unit 22. The current detection result of current detection unit 22 may be larger or smaller than it should be depending on the winding direction of the coil of current detection unit 22 or the orientation of the Hall element of current detection unit 22 relative to the magnetic field generated around current path P1.

[0064] Therefore, the cutoff control unit 10 may control the cutoff unit 40 based on the measured current flowing in one current path, the voltage of the battery 200, and the current flowing in the other current path. If an overcurrent flows in one current path, the detection result of the current flowing in the other current path will also change due to the influence of the overcurrent in one current path. Therefore, the cutoff unit 40 can be accurately controlled by using the measured current flowing in the other current path in addition to the measured current flowing in one current path and the voltage of the battery 200. For example, if an overcurrent is measured in one current path, and it is measured that the voltage of the battery 200 drops and the current flowing in the other current path has changed by a predetermined amount (for example, increased or decreased by a predetermined amount), it is possible to cut off the current from the battery 200, assuming that the overcurrent detection was normal.

[0065] (Other Embodiments) As described above, the embodiments have been described as examples of the technology according to the present disclosure. However, the technology according to the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. For example, the following modifications are also included in one embodiment of the present disclosure.

[0066] In the above-described embodiment, each component included in the shutdown device may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0067] Some or all of the functions of the shutdown device according to the above embodiments are typically realized as an LSI, which is an integrated circuit. These may be individually integrated into single chips, or may be integrated into a single chip that includes some or all of the functions. Furthermore, the integrated circuit is not limited to an LSI, and may be realized using a dedicated circuit or a general-purpose processor. It is also possible to use an FPGA (Field Programmable Gate Array) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI.

[0068] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derived technologies, it is natural that each component included in the circuit breaker may be integrated using that technology.

[0069] In addition, this disclosure also includes forms obtained by making various modifications to the embodiments that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions in each embodiment within the scope of the present disclosure.

[0070] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0071] (Technology 1) A disconnection device comprising: a disconnection control unit that controls a disconnection unit for cutting off current from a battery; a first current detection unit that detects current flowing in a first current path connecting the disconnection unit and a first load; a second current detection unit that detects current flowing in a second current path that connects the disconnection unit and a second load and is connected in parallel to the first current path; and a measurement unit that measures the current flowing in the first current path, the current flowing in the second current path, and the voltage of the battery, wherein the disconnection control unit controls the disconnection unit based on the measured current flowing in one of the first current path and the second current path, and the voltage of the battery.

[0072] According to this, the interrupter device includes a first current detection unit that detects the current flowing through the first current path and a second current detection unit that detects the current flowing through the second current path, thereby enhancing redundancy in abnormality detection. Furthermore, when an overcurrent is detected in one of the first and second current paths, if the overcurrent detection is correct, a large current flows from the battery, causing a drop in the battery voltage. On the other hand, if the overcurrent detection is erroneous, no large current actually flows from the battery, and the battery voltage does not drop. Therefore, if an overcurrent is measured in one current path but a drop in the battery voltage is not measured, the overcurrent detection can be determined to be erroneous, and the current from the battery can be prevented from being interrupted. This enhances redundancy in abnormality detection and reduces current interruption due to erroneous detection.

[0073] (Technology 2) The circuit breaker according to Technology 1, wherein the circuit breaker is a pyro-fuse.

[0074] This allows a large current to be cut off instantly in the event of an abnormality.

[0075] (Technology 3) An interrupter device according to Technology 1 or 2, wherein the first current detection unit has a first shunt resistor provided in the first current path, and the second current detection unit has a second shunt resistor provided in the second current path.

[0076] In this way, by using a shunt resistor, it is possible to detect the current flowing through the current path.

[0077] (Technology 4) The first current detection unit is connected between the interrupter and the first load in the first current path, the second current detection unit is connected between the interrupter and the second load in the second current path, the measurement unit measures a voltage at a terminal of the first shunt resistor on the interrupter side and a voltage at a terminal of the second shunt resistor on the interrupter side as the voltage of the battery, and the interruption control unit controls the interrupter based on the measured current flowing in one of the first current path and the second current path and a voltage at a terminal of the first shunt resistor or the second shunt resistor on the interrupter side, which is provided in the other current path of the first current path and the second current path.

[0078] According to this, when each current detection unit (shunt resistor) is connected between the interrupter and the load, the voltage at the terminal on the interrupter side of each shunt resistor becomes the battery voltage. Therefore, if an overcurrent is measured in one current path but a voltage drop is not measured at the terminal on the interrupter side of the shunt resistor provided in the other current path, it is possible to determine that the overcurrent detection was a false detection and not interrupt the current from the battery.

[0079] (Technology 5) In the circuit breaking device described in Technology 4, the measurement unit measures the voltage between the terminal of the first shunt resistor on the circuit breaking unit side and the terminal of the first shunt resistor on the first load side as the current flowing in the first current path, and measures the voltage between the terminal of the second shunt resistor on the circuit breaking unit side and the terminal of the second shunt resistor on the second load side as the current flowing in the second current path.

[0080] In this way, the current flowing through the current path can be measured from the voltage across the shunt resistor.

[0081] (Technology 6) The first current detection unit is connected between the first load and the negative side of the battery, the second current detection unit is connected between the second load and the negative side of the battery, and the measurement unit measures the voltage between the first load side terminal of the first shunt resistor and the negative side terminal of the battery as the current flowing in the first current path, and measures the voltage between the second load side terminal of the second shunt resistor and the negative side terminal of the battery as the current flowing in the second current path.

[0082] In this way, each shunt resistor may be connected between the load and the negative side of the battery, and in this case, the battery voltage and the current flowing through each current path can be measured. Therefore, the cutoff unit can be controlled based on the current flowing through one of the first and second current paths and the battery voltage, thereby increasing the redundancy of abnormality detection and preventing current cutoff due to erroneous detection.

[0083] (Technology 7) The circuit breaker according to any one of techniques 3 to 6, wherein the measurement unit measures the voltage via a voltage follower circuit.

[0084] This allows the voltage to be measured accurately through impedance conversion by the voltage follower circuit.

[0085] (Technology 8) The first current detection unit detects the current flowing in the first current path using a coil or a Hall element, and the second current detection unit detects the current flowing in the second current path using a coil or a Hall element, in a circuit breaking device described in Technology 1 or 2.

[0086] In this way, by using a coil or a Hall element, the current flowing through the current path can be detected in a non-contact manner.

[0087] (Technology 9) A circuit breaking device described in any one of Technologies 1 to 8, wherein the circuit breaking control unit controls the circuit breaking unit to cut off the current from the battery when the measured current flowing in one of the current paths is equal to or greater than a predetermined current value and the voltage of the battery is equal to or less than a predetermined voltage.

[0088] According to this, if an overcurrent is measured in one current path and a drop in the battery voltage is measured, it is determined that the overcurrent detection was normal and the current from the battery can be cut off.

[0089] (Technology 10) A circuit breaking device according to any one of technologies 1 to 8, wherein the circuit breaking control unit controls the circuit breaking unit based on the measured current flowing in one of the current paths, the voltage of the battery, and the current flowing in the other of the first current path and the second current path.

[0090] If an overcurrent flows in one current path, the current flowing in the other current path will also change due to a drop in battery voltage, etc. Therefore, by using the current flowing in one current path and the battery voltage as well as the current flowing in the other current path, the cut-off unit can be controlled with high precision.

[0091] (Technology 11) The cut-off control unit controls the cut-off unit to cut off the current from the battery when the measured current flowing in one of the current paths is equal to or greater than a predetermined current value, the voltage of the battery is equal to or less than a predetermined voltage, and the current flowing in the other current path has changed by a predetermined amount. This is a cut-off device described in Technology 10.

[0092] According to this, if an overcurrent is measured in one current path, the battery voltage drops, and if it is measured that the current flowing in the other current path has changed by a predetermined amount, it is determined that the overcurrent detection was normal and the current from the battery can be cut off.

[0093] The present disclosure can be applied to devices that interrupt large currents that flow through a current path when an abnormality occurs.

[0094] REFERENCE SIGNS LIST 10 Shutdown control unit 21, 22 Current detection unit 30 Measurement unit 31, 32, 33, 34 Voltage follower circuit 35, 36 Differential amplifier circuit 40 Shutdown unit 41 Pyro fuse 100, 100a, 100b Shutdown device 200 Battery 201 Casing unit 202 Ignition unit 203 Piston 204 Bus bar 301, 302 Load P1, P2 Current path R1, R2 Shunt resistor

Claims

1. a cutoff control unit that controls a cutoff unit for cutting off current from the battery; a first current detection unit that detects a current flowing through a first current path that connects the interrupter unit and a first load; a second current detection unit that detects a current flowing through a second current path that connects the interrupter unit and a second load and is connected in parallel to the first current path; a measurement unit that measures a current flowing through the first current path, a current flowing through the second current path, and a voltage of the battery; the cutoff control unit controls the cutoff unit based on the measured current flowing through one of the first current path and the second current path and the voltage of the battery. Shut-off device.

2. The interrupter is a pyro fuse. The shutoff device according to claim 1 .

3. the first current detection unit has a first shunt resistor provided in the first current path, the second current detection unit has a second shunt resistor provided in the second current path; The shutoff device according to claim 1 .

4. the first current detection unit is connected between the interrupter unit and the first load in the first current path, the second current detection unit is connected between the interrupter unit and the second load in the second current path, the measurement unit measures a voltage at a terminal of the first shunt resistor on the interrupter side and a voltage at a terminal of the second shunt resistor on the interrupter side as voltages of the battery, the cutoff control unit controls the cutoff unit based on the measured current flowing through one of the first current path and the second current path and a voltage at a terminal on the cutoff unit side of the first shunt resistor or the second shunt resistor, which is provided in the other of the first current path and the second current path. The shutoff device according to claim 3.

5. The measurement unit measuring a voltage between a terminal of the first shunt resistor on the interrupter side and a terminal of the first shunt resistor on the first load side as a current flowing through the first current path; a voltage between a terminal of the second shunt resistor on the interrupter side and a terminal of the second shunt resistor on the second load side is measured as the current flowing through the second current path; The shutoff device according to claim 4.

6. the first current detection unit is connected between the first load and the negative side of the battery; the second current detection unit is connected between the second load and the negative side of the battery, The measurement unit measuring a voltage between a terminal of the first shunt resistor on the first load side and a terminal of the first shunt resistor on the negative side of the battery as a current flowing through the first current path; a voltage between a terminal of the second shunt resistor on the second load side and a terminal of the second shunt resistor on the negative side of the battery is measured as the current flowing through the second current path; The shutoff device according to claim 3.

7. the measurement unit measures the voltage via a voltage follower circuit; The shutoff device according to claim 3.

8. the first current detection unit detects the current flowing through the first current path using a coil or a Hall element; the second current detection unit detects the current flowing through the second current path using a coil or a Hall element; The shutoff device according to claim 1 .

9. the cutoff control unit controls the cutoff unit to cut off the current from the battery when the measured current flowing through the one current path is equal to or greater than a predetermined current value and the voltage of the battery is equal to or less than a predetermined voltage. The interrupter according to any one of claims 1 to 8.

10. the cutoff control unit controls the cutoff unit based on the measured current flowing through the one current path, the voltage of the battery, and the measured current flowing through the other current path of the first current path and the second current path. The interrupter according to any one of claims 1 to 8.

11. the cutoff control unit controls the cutoff unit to cut off the current from the battery when the measured current flowing through the one current path is equal to or greater than a predetermined current value, the voltage of the battery is equal to or less than a predetermined voltage, and the current flowing through the other current path has changed by a predetermined amount. The shutoff device of claim 10.