Current interruption device

Abstract

This technology provides a way to easily interrupt current in both series and parallel connections. [Solution] The current interruption device 30 comprises a first interruption unit 41, a second interruption unit 42, and a control unit 50. The control unit 50 switches the first interruption unit 41 to a first interruption state when the current flowing through the first conductive path 31 exceeds the series threshold in a series connection state, switches the first interruption unit 41 to a first interruption state when the current flowing through the first conductive path 31 exceeds the first parallel threshold in a parallel connection state, and switches the second interruption unit 42 to a second interruption state when the current flowing through the second conductive path 32 exceeds the second parallel threshold in a parallel connection state. The first parallel threshold and the second parallel threshold are smaller than the series threshold.

Description

Technical Field

[0001] This disclosure relates to a current interruption device.

Background Art

[0002] Patent Document 1 discloses a vehicle power interruption system. This vehicle power interruption system includes an interruption control unit and an explosive interruption unit. When an overcurrent occurs in the conductor part of the explosive interruption unit, for example, the interruption control unit switches by physically destroying the explosive interruption unit from the connected state to the interrupted state.

[0003] Patent Document 2 discloses a power supply system in which a first high-voltage battery and a second high-voltage battery can be switched between series connection and parallel connection.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the power supply system of Patent Document 2, there is a conductive path through which current flows in series connection and only the output current of one battery flows in parallel connection. When interrupting the current using an interruption part such as the explosive interruption part of Patent Document 1 in this conductive path, if the overcurrent threshold is set assuming the overcurrent in series connection, there is a possibility that it cannot be interrupted in parallel connection. Conversely, if the overcurrent threshold is set assuming the overcurrent in parallel connection, there is a possibility that it will be interrupted even though there is no overcurrent in series connection.

[0006] An object of this disclosure is to provide a technique that can appropriately interrupt current easily in both series connection and parallel connection states. [Means for solving the problem]

[0007] The current interruption device of this disclosure is A current interruption device included in an in-vehicle system comprising: a battery including a first battery and a second battery that can switch between series and parallel connections; a first conductive path through which current flows when the battery is in series and through which the first battery flows when the battery is in parallel and through which the first battery flows when the battery is in parallel and through which the second battery flows; and a second conductive path through which current flows when the battery is in series and through which the second battery flows when the battery is in parallel and through which the first battery flows when the battery is in parallel and through which the second battery flows when the battery is in parallel, A first interruption unit that switches from a first allowable state that allows current to flow through the first conductive path to a first interruption state that interrupts the current flowing through the first conductive path, A second interruption unit that switches from a second allowable state that permits current to flow through the second conductive path to a second interruption state that interrupts the current flowing through the second conductive path, The system comprises a control unit that controls the first interruption unit and the second interruption unit, The control unit switches the first interruption unit to the first interruption state when the current flowing through the first conductive path exceeds the series threshold in the series connection state, switches the first interruption unit to the first interruption state when the current flowing through the first conductive path exceeds the first parallel threshold in the parallel connection state, and switches the second interruption unit to the second interruption state when the current flowing through the second conductive path exceeds the second parallel threshold in the parallel connection state. The first parallel threshold and the second parallel threshold are smaller than the series threshold. [Effects of the Invention]

[0008] According to the technology disclosed herein, it is possible to appropriately interrupt the current in both series and parallel connection states. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing an in-vehicle system including a current interruption device according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing the in-vehicle system of the first embodiment when connected in series. [Figure 3] Figure 3 is a schematic diagram showing the in-vehicle system of the first embodiment when connected in parallel. [Figure 4] Figure 4 is a conceptual diagram illustrating how the in-vehicle system of the first embodiment is short-circuited while connected in series. [Figure 5] Figure 5 is a conceptual diagram illustrating the state in which the first conductive path is short-circuited in the in-vehicle system of the first embodiment while it is connected in parallel. [Figure 6] Figure 6 is a conceptual diagram illustrating the state in which the second conductive path is short-circuited in the in-vehicle system of the first embodiment while it is connected in parallel. [Figure 7] Figure 7 is a flowchart showing the processing performed by the first control circuit of the first embodiment. [Figure 8] Figure 8 is a flowchart showing the processing performed by the second control circuit of the first embodiment. [Figure 9] Figure 9 is a schematic diagram showing an in-vehicle system including a current interruption device according to the second embodiment. [Modes for carrying out the invention]

[0010] [Description of Embodiments in this Disclosure] First, the embodiments of this disclosure will be listed and described.

[0011] A vehicle-mounted system including a battery including a first battery and a second battery that can be switched between series connection and parallel connection, a first conductive path through which a current flowing through the first battery and the second battery flows in the case of the series connection and only a current flowing through the first battery flows among a current flowing through the first battery and a current flowing through the second battery in the case of the parallel connection, and a second conductive path through which a current flowing through the first battery and the second battery flows in the case of the series connection and only a current flowing through the second battery flows among a current flowing through the first battery and a current flowing through the second battery in the case of the parallel connection, and a current cutoff device included in the vehicle-mounted system, a first cutoff unit that switches from a first allowable state in which a current is allowed to flow through the first conductive path to a first cutoff state in which the current flowing through the first conductive path is cutoff; a second cutoff unit that switches from a second allowable state in which a current is allowed to flow through the second conductive path to a second cutoff state in which the current flowing through the second conductive path is cutoff; and a control unit that controls the first cutoff unit and the second cutoff unit, wherein the control unit switches the first cutoff unit to the first cutoff state when the current flowing through the first conductive path exceeds a series-use threshold value in the series connection state, switches the first cutoff unit to the first cutoff state when the current flowing through the first conductive path exceeds a first parallel-use threshold value in the parallel connection state, and switches the second cutoff unit to the second cutoff state when the current flowing through the second conductive path exceeds a second parallel-use threshold value in the parallel connection state, and the first parallel-use threshold value and the second parallel-use threshold value are smaller than the series-use threshold value Current cutoff device.

[0012] In the case of series connection, when the current flowing through the first conductive path exceeds the series threshold value, the control unit of the current interruption device can interrupt the current flowing through the first conductive path. Also, in the case of parallel connection, the control unit can detect an overcurrent in the first conductive path using a smaller threshold value compared to the case of series connection and interrupt the current flowing through the first conductive path. Further, in the case of parallel connection, the control unit can detect an overcurrent in the second conductive path using a smaller threshold value compared to the case of series connection and interrupt the current flowing through the second conductive path. That is, the current interruption device can appropriately interrupt the current easily in either the series connection state or the parallel connection state.

[0013] 〔2〕The first parallel threshold value and the second parallel threshold value are the same value. The current interruption device according to 〔1〕.

[0014] In the configuration where the output voltages of the first battery and the second battery are the same, the current interruption device can appropriately interrupt the current flowing through the first conductive path and the current flowing through the second conductive path easily when in parallel connection.

[0015] 〔3〕When the current flowing through the second conductive path exceeds the series threshold value in the series connection state, the control unit switches the second interruption unit to the second interruption state. The current interruption device according to 〔1〕 or 〔2〕.

[0016] In the case of series connection, when the current flowing through the first conductive path exceeds the series threshold value, the control unit switches the first interruption unit to the first interruption state, and when the current flowing through the second conductive path exceeds the series threshold value, the control unit switches the second interruption unit to the second interruption state. Therefore, when an overcurrent exceeding the series threshold value occurs in the series connection state, the current interruption device can more reliably interrupt the overcurrent.

[0017] 〔4〕The control unit determines whether it is in series connection or parallel connection based on the voltage of the battery. The current interruption device according to any one of 〔1〕 to 〔3〕.

[0018] With this configuration, the current interruption device can determine on its own whether the connections are in series or parallel.

[0019] [5] The control unit determines whether the connection is in series or parallel based on the current in the conductive path that switches between a state where current flows and a state where no current flows in the series connection and the parallel connection. A current interruption device as described in any of [1] to [3].

[0020] With this configuration, the current interruption device can determine on its own whether the connections are in series or parallel.

[0021] [6] The battery is housed in the case of the battery pack, The first shut-off unit, the second shut-off unit, and the control unit are housed within the case. A current interruption device as described in any of [1] to [5].

[0022] With this configuration, the first shut-off unit, the second shut-off unit, and the control unit can be housed together in the case that contains the battery.

[0023] [7] The control unit comprises a first control circuit and a second control circuit separate from the first control circuit, The first control circuit controls the first interruption unit, The 2nd control circuit controls the 2nd interruption unit. A current interruption device as described in any of [1] to [6].

[0024] With this configuration, the first and second interruption units can be controlled by separate control circuits.

[0025] [Details of the embodiments of this disclosure] 1. First Embodiment 1-1. Configuration of In-Vehicle System 1 The in-vehicle system 1 shown in Figure 1 comprises a battery 10, a power line 11, and a load 12. The power line 11 is provided between the battery 10 and the load 12. Power is supplied from the battery 10 to the load 12 via the power line 11. The power line 11 has a positive-side power line 11A and a negative-side power line 11B.

[0026] The battery 10 includes a first battery 13 and a second battery 14. The first battery 13 and the second battery 14 are composed of, for example, lithium-ion batteries or sodium-ion batteries. In this embodiment, the output voltage of the first battery 13 when fully charged and the output voltage of the second battery 14 when fully charged are the same, for example, 400V.

[0027] The first battery 13 and the second battery 14 switch between series connection and parallel connection between the positive-side power path 11A and the negative-side power path 11B. When connected in series, the output voltage of battery 10 is, for example, 800V. When connected in parallel, the output voltage of battery 10 is, for example, 400V.

[0028] In series connection, the positive terminal 13A of the first battery 13 is electrically connected to the positive power line 11A, the negative terminal 13B of the first battery 13 is electrically connected to the positive terminal 14A of the second battery 14, and the negative terminal 14B of the second battery 14 is electrically connected to the negative power line 11B. In parallel connection, the positive terminal 13A of the first battery 13 and the positive terminal 14A of the second battery 14 are electrically connected to the positive power line 11A, and the negative terminal 13B of the first battery 13 and the negative terminal 14B of the second battery 14 are electrically connected to the negative power line 11B.

[0029] The in-vehicle system 1 includes a switching unit 20. The switching unit 20 switches between a series connection and a parallel connection of the first battery 13 and the second battery 14. The switching unit 20 switches between a first state in which the first battery 13 and the second battery 14 are connected in series, and a second state in which the first battery 13 and the second battery 14 are connected in parallel.

[0030] The switching unit 20 includes a first switch unit 21, a second switch unit 22, and a third switch unit 23. The first switch unit 21, the second switch unit 22, and the third switch unit 23 are also referred to as switch units 21, 22, and 23. The switch units 21, 22, and 23 may be composed of semiconductor switching elements such as MOSFETs, or they may be composed of mechanical switches having contacts. The switch units 21, 22, and 23 are connected in series between the positive-side power path 11A and the negative-side power path 11B. The switch units 21, 22, and 23 are arranged in order from the positive-side power path 11A to the negative-side power path 11B.

[0031] The second switch unit 22 is provided between the negative terminal 13B of the first battery 13 and the positive terminal 14A of the second battery 14. The first switch unit 21 is provided between the conductive path between the second switch unit 22 and the positive terminal 14A of the second battery 14 and the positive power path 11A. The third switch unit 23 is provided between the conductive path between the first switch unit 21 and the negative terminal 13B of the first battery 13 and the negative power path 11B.

[0032] As shown in Figure 2, the switching unit 20 enters a first state when the second switch unit 22 is ON and the first switch unit 21 and the third switch unit 23 are OFF. As a result, current flows as shown by the arrows in Figure 2. As shown in Figure 3, the switching unit 20 enters a second state when the second switch unit 22 is OFF and the first switch unit 21 and the third switch unit 23 are ON. As a result, current flows as shown by the arrows in Figure 3.

[0033] The in-vehicle system 1 includes a switching control unit 24 that controls the switching unit 20. The switching control unit 24 is configured, for example, by a microcomputer. The switching control unit 24 switches the switching unit 20 between a first state and a second state.

[0034] The in-vehicle system 1 includes a battery pack case 25. The case 25 houses the battery 10, the switching unit 20, and the switching control unit 24.

[0035] The in-vehicle system 1 includes a first conductive path 31 and a second conductive path 32. The first conductive path 31 is a conductive path through which current flows when connected in series, through which current flows through the first battery 13 and the second battery 14, and when connected in parallel, through which only the current flowing through the first battery 13 flows. Specifically, the first conductive path 31 is a conductive path through which the first battery 13 is provided, and is a conductive path between a first connection point P1 between one end of the first switch unit 21 and the positive electrode side power path 11A, and a third connection point P3 between the other end of the second switch unit 22 and one end of the third switch unit 23.

[0036] The second conductive path 32 is a conductive path through which current flows when the batteries are connected in series, and through which only the current flowing through the second battery 14 flows when the batteries are connected in parallel. Specifically, the second conductive path 32 is a conductive path through which the second battery 14 is provided, and is a conductive path between the second connection point P2 between the other end of the first switch unit 21 and one end of the second switch unit 22, and the fourth connection point P4 between the other end of the third switch unit 23 and the negative electrode power path 11B.

[0037] Incidentally, when a short circuit occurs in the in-vehicle system 1, the magnitude of the overcurrent flowing through the first conductive path 31 and the second conductive path 32 may differ depending on whether the connections are in series or parallel. For example, as shown in Figure 4, if the positive power path 11A is short-circuited to the negative power path 11B in a series connection, the current loops along the path indicated by the arrow in Figure 4, resulting in an overcurrent. Also, as shown in Figure 5, if one end of the first conductive path 31 is short-circuited to the other end in a parallel connection, the current loops along the path indicated by the arrow in Figure 5, resulting in an overcurrent. Furthermore, as shown in Figure 6, if one end of the second conductive path 32 is short-circuited to the other end in a parallel connection, the current loops along the path indicated by the arrow in Figure 6, resulting in an overcurrent. In the case of Figure 5, the magnitude of the overcurrent flowing through the first conductive path 31 is smaller compared to the case of Figure 4. In the case of Figure 6, the magnitude of the overcurrent flowing through the second conductive path 32 is smaller compared to the case of Figure 4. Therefore, in order to appropriately interrupt the current in any state, the in-vehicle system 1 includes a current interruption device 30.

[0038] 1-2. Configuration of the current interruption device 30 The current interruption device 30 is housed in the case 25. The current interruption device 30 comprises a first interruption unit 41, a second interruption unit 42, a first current detection unit 43, a second current detection unit 44, a voltage detection unit 45, and a control unit 50. The first conductive path 31, the second conductive path 32, the first interruption unit 41, the second interruption unit 42, the first current detection unit 43, the second current detection unit 44, the voltage detection unit 45, and the control unit 50 are housed in the case 25.

[0039] The first interruption unit 41 is provided in the first conductive path 31. The first interruption unit 41 switches from a first allowable state, which permits current to flow through the first conductive path 31, to a first interruption state, which interrupts the current flowing through the first conductive path 31. The second interruption unit 42 is provided in the second conductive path 32. The second interruption unit 42 switches from a second allowable state, which permits current to flow through the second conductive path 32, to a second interruption state, which interrupts the current flowing through the second conductive path 32. The first interruption unit 41 and the second interruption unit 42 may be configured by, for example, a pyroelectric circuit breaker such as a pyro fuse, by a semiconductor switching element, or by a mechanical switch having contacts.

[0040] The first current detection unit 43 detects the current flowing through the first conductive path 31. The first current detection unit 43 is configured, for example, by a known current sensor. The signal indicating the detection result from the first current detection unit 43 is input to the control unit 50. The second current detection unit 44 detects the current flowing through the second conductive path 32. The second current detection unit 44 is configured, for example, by a known current sensor. The signal indicating the detection result from the second current detection unit 44 is input to the control unit 50. The voltage detection unit 45 detects the voltage across the battery 10. The voltage detection unit 45 is configured, for example, by a known voltage detection circuit. The signal indicating the detection result from the voltage detection unit 45 is input to the control unit 50.

[0041] The control unit 50 is provided separately from the switching control unit 24. The control unit 50 controls the first interruption unit 41 and the second interruption unit 42. When the current flowing through the first conductive path 31 exceeds the series threshold in a series connection state, the control unit 50 switches the first interruption unit 41 to the first interruption state. When the current flowing through the first conductive path 31 exceeds the first parallel threshold in a parallel connection state, the control unit 50 switches the second interruption unit 42 to the second interruption state when the current flowing through the second conductive path 32 exceeds the series threshold in a series connection state. When the current flowing through the second conductive path 32 exceeds the second parallel threshold in a parallel connection state, the control unit 50 switches the second interruption unit 42 to the second interruption state. The first parallel threshold and the second parallel threshold are smaller than the series threshold. In this embodiment, the first parallel threshold and the second parallel threshold are the same, but they do not have to be the same. The serial threshold, the first parallel threshold, and the second parallel threshold may be fixed values ​​or variable values.

[0042] The control unit 50 determines whether the batteries 10 are connected in series or in parallel based on their voltage. For example, the control unit 50 determines that the batteries are connected in series if the voltage of the batteries 10 exceeds a threshold voltage, and determines that they are connected in parallel if the voltage of the batteries 10 is below the threshold voltage. The threshold voltage is, for example, 600V.

[0043] The control unit 50 includes a first control circuit 51 and a second control circuit 52. The first control circuit 51 controls the first interruption unit 41. The second control circuit 52 is provided separately from the first control circuit 51 and controls the second interruption unit 42. The control by the first control circuit 51 and the control by the second control circuit 52 may be implemented by hardware or by software.

[0044] The first control circuit 51 receives a signal indicating the detection result from the voltage detection unit 45. The first control circuit 51 determines whether the battery 10 is connected in series or in parallel based on the voltage of the battery 10. If the first control circuit 51 determines that it is connected in series, it determines whether the current flowing through the first conductive path 31 exceeds the series threshold. If the first control circuit 51 determines that the current flowing through the first conductive path 31 exceeds the series threshold, it switches the first interruption unit 41 to the first interruption state. If the first control circuit 51 determines that it is connected in parallel, it determines whether the current flowing through the first conductive path 31 exceeds the first parallel threshold. If the first control circuit 51 determines that the current flowing through the first conductive path 31 exceeds the first parallel threshold, it switches the first interruption unit 41 to the first interruption state.

[0045] The first control circuit 51 performs the processing shown in Figure 7, for example. In step S11, the first control circuit 51 determines whether the voltage of the battery 10 a predetermined time ago exceeds the threshold voltage. The reason for specifying "a predetermined time ago" is to refer to the voltage of the battery 10 before it is affected by a short circuit in the event of a short circuit. The predetermined time is, for example, 10 seconds. If the first control circuit 51 determines that the voltage of the battery 10 a predetermined time ago exceeds the threshold voltage (if Yes in step S11), in step S12, it sets the series threshold as the overcurrent threshold. If the first control circuit 51 determines that the voltage of the battery 10 a predetermined time ago does not exceed the threshold voltage (if No in step S11), in step S13, it sets the first parallel threshold as the overcurrent threshold. After step S12 or after step S13, the first control circuit 51 determines whether the current flowing through the first conductive path 31 exceeds the overcurrent threshold. If the first control circuit 51 determines that the current flowing through the first conductive path 31 does not exceed the overcurrent threshold (if the answer is No in step S14), it returns to step S11. If the first control circuit 51 determines that the current flowing through the first conductive path 31 exceeds the overcurrent threshold (if the answer is Yes in step S14), it switches the first interruption unit 41 to the first interruption state in step S15.

[0046] The second control circuit 52 receives a signal indicating the detection result from the voltage detection unit 45. The second control circuit 52 determines whether the battery 10 is connected in series or in parallel based on the voltage of the battery 10. If the second control circuit 52 determines that it is connected in series, it determines whether the current flowing through the second conductive path 32 exceeds the series threshold. If the second control circuit 52 determines that the current flowing through the second conductive path 32 exceeds the series threshold, it switches the second interruption unit 42 to the second interruption state. If the second control circuit 52 determines that it is connected in parallel, it determines whether the current flowing through the second conductive path 32 exceeds the second parallel threshold. If the second control circuit 52 determines that the current flowing through the second conductive path 32 exceeds the second parallel threshold, it switches the second interruption unit 42 to the second interruption state.

[0047] The second control circuit 52 performs the processing shown in Figure 8, for example. In step S21, the second control circuit 52 determines whether the voltage of the battery 10 a predetermined time ago exceeds the threshold voltage. If the second control circuit 52 determines that the voltage of the battery 10 a predetermined time ago exceeds the threshold voltage (if Yes in step S21), in step S22, it sets the series threshold as the overcurrent threshold. If the second control circuit 52 determines that the voltage of the battery 10 a predetermined time ago does not exceed the threshold voltage (if No in step S21), it sets the second parallel threshold as the overcurrent threshold in step S23. After step S22 or after step S23, the second control circuit 52 determines whether the current flowing through the second conductive path 32 exceeds the overcurrent threshold. If the second control circuit 52 determines that the current flowing through the second conductive path 32 does not exceed the overcurrent threshold (if No in step S24), it returns to step S21. If the second control circuit 52 determines that the current flowing through the second conductive path 32 exceeds the overcurrent threshold (if the answer is Yes in step S24), it switches the second interruption unit 42 to the second interruption state in step S25.

[0048] 1-3. Effects of the First Embodiment The control unit 50 of the current interruption device 30 can interrupt the current flowing through the first conductive path 31 when the current flowing through the first conductive path 31 exceeds the series threshold when the devices are connected in series. In parallel, the control unit 50 can detect overcurrent in the first conductive path 31 using a smaller threshold than when connected in series, and interrupt the current flowing through the first conductive path 31. In parallel, the control unit 50 can detect overcurrent in the second conductive path 32 using a smaller threshold than when connected in series, and interrupt the current flowing through the second conductive path 32. In other words, the current interruption device 30 can easily interrupt the current appropriately in both series and parallel connections.

[0049] The output voltages of the first battery 13 and the second battery 14 are the same, and the threshold values ​​for the first parallel connection and the threshold values ​​for the second parallel connection are the same. Therefore, the current interruption device 30 can easily interrupt the current flowing through the first conductive path 31 and the second conductive path 32 when connected in parallel.

[0050] In a series connection state, the control unit 50 switches the first interruption unit 41 to the first interruption state when the current flowing through the first conductive path 31 exceeds the series threshold, and switches the second interruption unit 42 to the second interruption state when the current flowing through the second conductive path 32 exceeds the series threshold. Therefore, the current interruption device 30 can more reliably interrupt overcurrents when a current exceeding the series threshold occurs in a series connection state.

[0051] The control unit 50 determines whether the batteries 10 are connected in series or in parallel based on their voltage. Therefore, the current interruption device 30 can determine whether the batteries are connected in series or in parallel on its own without obtaining information from the switching control unit 24.

[0052] The first shut-off unit 41, the second shut-off unit 42, and the control unit 50 are all housed together in the case 25 that houses the battery 10.

[0053] The current interruption device 30 can control the first interruption unit 41 and the second interruption unit 42 by separate control circuits.

[0054] 2. Second Embodiment In the second embodiment, an example of determining whether a connection is in series or parallel using a method different from that of the first embodiment will be described. In the second embodiment, the same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations are omitted.

[0055] As shown in Figure 9, the in-vehicle system 201 of the second embodiment includes a current interruption device 230 instead of the current interruption device 30 of the first embodiment. The current interruption device 230 includes a third current detection unit 245 instead of the voltage detection unit 45 of the first embodiment.

[0056] The in-vehicle system 201 includes a conductive path 33 that switches between a state where current flows and a state where no current flows depending on whether it is connected in series or in parallel. The conductive path 33 is a conductive path on which a second switch unit 22 is provided, and is a conductive path provided between a second connection unit P2 and a third connection unit P3. Current flows through the conductive path 33 when it is connected in series, and no current flows when it is connected in parallel. The third current detection unit 245 detects the current flowing through the conductive path 33. The third current detection unit 245 is configured, for example, by a known current sensor. The signal indicating the detection result of the third current detection unit 245 is input to the control unit 50. The control unit 50 determines whether it is connected in series or in parallel based on the current flowing through the conductive path 33. Specifically, the control unit 50 determines that it is connected in series if the current flowing through the conductive path 33 exceeds a threshold current, and determines that it is connected in parallel if the current flowing through the conductive path 33 is less than or equal to the threshold current.

[0057] The control unit 50 performs the processing shown in Figures 7 and 8 described in the first embodiment. However, in step S11 of Figure 7 and step S21 of Figure 8, the control unit 50 performs the processing of determining whether the current flowing through the conductive path 33 exceeds the threshold current, instead of determining whether the voltage of the battery 10 a predetermined time ago exceeds the threshold voltage.

[0058] As described above, the current interruption device 230 of the second embodiment can also determine whether the connections are in series or parallel without obtaining information from the switching control unit 24.

[0059] <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. In addition, the embodiments described above may be modified as follows.

[0060] In the embodiments described above, the threshold for the first parallelism and the threshold for the second parallelism were the same value, but the threshold for the first parallelism and the threshold for the second parallelism may be different values.

[0061] In the above embodiments, the control unit 50 was configured such that, in a series connection state, the first interruption unit 41 was switched to the first interruption state when the current flowing through the first conductive path 31 exceeded the series threshold, and the second interruption unit 42 was switched to the second interruption state when the current flowing through the second conductive path 32 exceeded the series threshold. In contrast, the control unit 50 may be configured such that, in a series connection state, the first interruption unit 41 is switched to the first interruption state when the current flowing through the first conductive path 31 exceeds the series threshold, while the second interruption unit 42 is not switched to the second interruption state even if the current flowing through the second conductive path 32 exceeds the series threshold.

[0062] The arrangement of the first battery 13 and the second battery 14 may be reversed. In the above embodiments, the first battery 13 was positioned on the positive electrode side of the power path 11A than the second battery 14, but the first battery 13 may also be positioned on the negative electrode side of the power path 11B than the second battery 14.

[0063] In the embodiments described above, the switching control unit 24 was provided separately from the control unit 50, but the switching control unit 24 may also be included in the control unit 50. In this case, the control unit 50 does not need to determine whether the connections are in series or parallel based on the voltage of the battery 10 or the current flowing through the conductive path 33.

[0064] In the above embodiments, the control entity that controls the first interruption unit 41 and the control entity that controls the second interruption unit 42 were separate, but they may be a single entity.

[0065] In the second embodiment described above, the "conductive path that switches between a state where current flows and a state where no current flows depending on whether it is connected in series or in parallel" was a "conductive path where current flows when connected in series and no current flows when connected in parallel," but it may also be a "conductive path where no current flows when connected in series and current flows when connected in parallel."

[0066] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0067] 1…In-vehicle systems 10…Battery 11…Power line 11A…Positive side power path 11B…Negative side power path 12…Load 13…Battery No. 1 13A...Positive terminal of the first battery 13B... Negative terminal of the first battery 14…Second Battery 14A...Positive terminal of the second battery 14B...Positive terminal of the second battery 20…Switching section 21…First switch section 22...Second switch section 23…Third switch section 24…Switching control unit 25...case 30... Current interruption device 31…First conductive path 32...Second conductive circuit 33... A conductive circuit that switches between a state where current flows and a state where it does not flow depending on whether it is connected in series or parallel. 41...First Shut-off Section 42...Second Shut-off Section 43...First current detection unit 44...Second current detection unit 45...Voltage detection unit 50…Control Unit 51...First control circuit 52...Second control circuit 201... In-vehicle systems 230... Current interruption device 243...Current detection unit P1...First connection point P2...Second connection point P3...Third connection point P4...Fourth connection point

Claims

1. A current interruption device included in an in-vehicle system comprising: a battery including a first battery and a second battery that can switch between series and parallel connections; a first conductive path through which current flows when the battery is in series and through which the first battery flows when the battery is in parallel and through which the first battery flows when the battery is in parallel and through which the second battery flows; and a second conductive path through which current flows when the battery is in series and through which the second battery flows when the battery is in parallel and through which the second battery flows when the battery is in parallel, wherein A first interruption unit that switches from a first allowable state that allows current to flow through the first conductive path to a first interruption state that interrupts the current flowing through the first conductive path, A second interruption unit that switches from a second allowable state that permits current to flow through the second conductive path to a second interruption state that interrupts the current flowing through the second conductive path, The system comprises a control unit that controls the first interruption unit and the second interruption unit, The control unit switches the first interruption unit to the first interruption state when the current flowing through the first conductive path exceeds the series threshold in the series connection state, switches the first interruption unit to the first interruption state when the current flowing through the first conductive path exceeds the first parallel threshold in the parallel connection state, and switches the second interruption unit to the second interruption state when the current flowing through the second conductive path exceeds the second parallel threshold in the parallel connection state. The first parallel threshold and the second parallel threshold are smaller than the series threshold. Current interruption device.

2. The first parallel threshold and the second parallel threshold are the same value. The current interruption device according to claim 1.

3. The control unit switches the second interruption unit to the second interruption state when the current flowing through the second conductive path exceeds the series threshold in the series connection state. The current interruption device according to claim 1 or claim 2.

4. The control unit determines whether the battery is connected in series or in parallel based on the battery voltage. The current interruption device according to claim 1 or claim 2.

5. The control unit determines whether the connection is in series or parallel based on the current in the conductive path, which switches between a state where current flows and a state where no current flows in the series connection and the parallel connection. The current interruption device according to claim 1 or claim 2.

6. The aforementioned battery is housed within the battery pack case. The first shut-off unit, the second shut-off unit, and the control unit are housed within the case. The current interruption device according to claim 1 or claim 2.

7. The control unit comprises a first control circuit and a second control circuit separate from the first control circuit. The first control circuit controls the first interruption unit, The second control circuit controls the second interruption unit. The current interruption device according to claim 1 or claim 2.

Images