Shut-off control device

Abstract

A shut-off control device (1) is used in an in-vehicle system (100). The in-vehicle system (100) comprises a power supply unit (90), a power path (80), a switch (11), and a shut-off unit (12). The power path (80) is a path through which power is transmitted between the power supply unit (90) and a load (91). The switch (11) is provided in the power path (80) and switches the power path (80) to an energization state and a non-energization state. The shut-off unit (12) switches from an allowable state in which power is allowed to be supplied from the power supply unit (90) side to the load (91) side in the power path (80) to a shut-off state in which the power is shut off. The shut-off control device (1) has a control unit (14) that switches the shut-off unit (12) to a shut-off state when the value of current flowing through the power path (80) exceeds a first threshold value (Ith1). The first threshold value (Ith1) is smaller than a second threshold value (Ith2) that is the maximum current value with which the switch (11) can maintain the power path (80) in the energization state.

Description

[Technical Field]

[0001] The present disclosure relates to a shutoff control device. [Background technology]

[0002] The background art of Patent Document 1 discloses a load circuit that supplies power to a load. This load circuit includes a battery and a switch (semiconductor switch) provided between the battery and the load, and the load is switched between being driven and stopped by turning the switch on and off. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-35951 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned switches may not operate normally if a current exceeding a threshold flows through them. When attempting to design a switch that can withstand a larger current, the switch tends to become larger.

[0005] The present disclosure aims to provide a technique that can prevent a switch from malfunctioning while suppressing an increase in size of the switch. [Means for solving the problem]

[0006] The shutoff control device of the present disclosure includes: A power supply unit; a power path that is a path through which power is transmitted between the power supply unit and a load; a switch provided on the power path and configured to switch the power path between a conducting state and a non-conducting state; a cutoff unit that switches from a permissive state that allows power to be supplied from the power supply unit side to the load side in the power path to a cutoff state that cuts off the power; A shut-off control device used in an in-vehicle system comprising: a control unit that switches the interrupter to the interrupted state when a value of a current flowing through the power path exceeds a first threshold; The first threshold value is smaller than a second threshold value that is a maximum current value at which the switch can maintain the power path in the energized state. [Effects of the Invention]

[0007] The technology of the present disclosure can prevent the switch from becoming too large and also prevent the switch from malfunctioning. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram illustrating a vehicle-mounted system including a cutoff control device according to the first embodiment. [Figure 2] FIG. 2 is a graph of correspondence data showing the correspondence relationship between the time elapsed since the ground fault occurred and the value of the current flowing through the power line. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the following, embodiments of the present disclosure are listed and illustrated.

[0010] [1] A power supply unit; a power path that is a path through which power is transmitted between the power supply unit and a load; a switch provided on the power path and configured to switch the power path between a conducting state and a non-conducting state; a cutoff unit that switches from a permissive state that allows power to be supplied from the power supply unit side to the load side in the power path to a cutoff state that cuts off the power; A shut-off control device used in an in-vehicle system comprising: a control unit that switches the interrupter to the interrupted state when a value of a current flowing through the power path exceeds a first threshold; The first threshold is smaller than a second threshold, which is a maximum current value at which the switch can maintain the power path in the energized state. Shut-off control device.

[0011] In the above-described tripping control device, the control unit switches the tripping unit to the tripping state when the value of the current flowing through the power path exceeds a first threshold. The first threshold is set to a value smaller than a second threshold, which is the maximum current value at which the switch can maintain the power path in a conductive state. This makes it easier for the control unit to switch the tripping unit to the tripping state before the switch can no longer maintain the power path in a conductive state. Therefore, even if the second threshold is reduced by suppressing the increase in the size of the switch, it becomes difficult for a current exceeding the second threshold to flow through the switch, making it easier to avoid a situation in which the switch is unable to maintain the power path in a conductive state. Therefore, with this configuration, it is possible to suppress the increase in size of the switch while preventing the switch from malfunctioning.

[0012] [2] The switch is an electromagnetic relay, and when the switch is in an on state, the power path is in the energized state, and when the switch is in an off state, the power path is in the non-energized state, and when a current greater than the second threshold flows through the switch, the on state is canceled by electromagnetic repulsion and the switch is switched to the off state. The shutoff control device described in [1].

[0013] According to this configuration, the control unit can easily switch the interrupter unit to the interrupting state before the switch in the on state is switched to the off state by the electromagnetic repulsive force.

[0014] [3] The second threshold value is smaller than a saturation current that flows through the power line when the power line has a ground fault. The shutoff control device according to [1] or [2].

[0015] According to this configuration, in order to prevent the switch from becoming large, a switch whose maximum current value that can maintain a conducting state is smaller than the saturation current can be used in the in-vehicle system, and in this configuration, it is possible to prevent the switch from malfunctioning.

[0016] [4] The first threshold value is set in consideration of a time lag between when it is determined that the current value flowing through the power path exceeds the first threshold value and when the breaker unit switches to the cut-off state, so that the breaker unit switches to the cut-off state before the current value flowing through the power path reaches the saturation current. The shutoff control device described in [3].

[0017] According to this configuration, the breaker unit can be switched to the breaker state before the value of the current flowing through the power path reaches the saturation current.

[0018] [5] The first threshold value is set in consideration of a time lag between when it is determined that the current value flowing through the power path exceeds the first threshold value and when the breaker unit switches to the cut-off state, so that the breaker unit switches to the cut-off state before the current value flowing through the power path reaches the second threshold value. The shutoff control device according to any one of [1] to [4].

[0019] With this configuration, the breaker can be switched to the breaker state before the value of the current flowing through the power path reaches the second threshold, thereby preventing a situation in which a current exceeding the second threshold flows through the switch and the switch is unable to maintain the power path in a conducting state.

[0020] [6] The first threshold value is greater than a third threshold value, which is a maximum current value that can flow through the power path in a normal state of the power path. The shutoff control device according to any one of [1] to [5].

[0021] This configuration makes it easier to prevent the breaker from being switched to the breaker state when the power path is in a normal state.

[0022] [7] The interrupter uses any one of a pyro-fuse, a semiconductor switch, and an electro-magnetic fuse. The shutoff control device according to any one of [1] to [6].

[0023] This configuration allows the interrupter to be quickly switched to the interrupted state.

[0024] First Embodiment 1 is a system mounted on a vehicle. The vehicle system 100 includes a power supply unit 90, a load 91, a power path 80, a cutoff control device 1, and a second control unit 92.

[0025] The power supply unit 90 is, for example, a DC power supply that generates a DC voltage, such as a battery. The battery is, for example, a lead battery, a lithium-ion battery, or the like. The load 91 is an electronic component provided in the vehicle. The load 91 is, for example, an electric component, an ECU, an ADAS target component, or the like. The power path 80 is a path through which power is transmitted between the power supply unit 90 and the load 91. One end of the power path 80 is electrically connected to the power supply unit 90, and the other end is electrically connected to the load 91.

[0026] The trip control device 1 is used in an in-vehicle system 100. The trip control device 1 is configured as, for example, a junction box. The trip control device 1 has a housing 10, a switch 11, a breaker 12, a current detector 13, and a control unit 14. The switch 11, the breaker 12, the current detector 13, and the control unit 14 are arranged inside the housing 10. The housing 10 has a first terminal unit 10A and a second terminal unit 10B.

[0027] The above-described power path 80 has a first wiring portion 81, a second wiring portion 82, and a conductive path 83. The first wiring portion 81 and the second wiring portion 82 are disposed outside the housing 10, and the conductive path 83 is disposed inside the housing 10.

[0028] The first wiring portion 81 is configured as, for example, an electric wire. One end of the first wiring portion 81 is electrically connected to the power supply portion 90, and the other end is electrically connected to the first terminal portion 10A. The second wiring portion 82 is configured as, for example, an electric wire. One end of the second wiring portion 82 is electrically connected to the second terminal portion 10B, and the other end is electrically connected to the load 91.

[0029] The conductive path 83 is configured as, for example, a bus bar. One end of the conductive path 83 is electrically connected to the first terminal 10A, and the other end is electrically connected to the second terminal 10B. The conductive path 83 has a first conductive path 84, a second conductive path 85, and a third conductive path 86. One end of the first conductive path 84 is electrically connected to the first terminal 10A, and the other end is electrically connected to one end of the interrupter 12. One end of the second conductive path 85 is electrically connected to the other end of the interrupter 12, and the other end is electrically connected to one end of the switch 11. One end of the third conductive path 86 is electrically connected to the other end of the switch 11, and the other end is electrically connected to the second terminal 10B.

[0030] The switch 11 is configured as, for example, an electromagnetic relay and has contacts that operate by electromagnetic force. The switch 11 is provided on the power path 80 (more specifically, the conductive path 83) and switches the power path 80 between a conductive state and a non-conductive state. The switch 11 is provided between the second conductive path 85 and the third conductive path 86 and switches the second conductive path 85 and the third conductive path 86 between a conductive state and a non-conductive state. When the second conductive path 85 and the third conductive path 86 are in a conductive state, the power path 80 is in a conductive state. When the second conductive path 85 and the third conductive path 86 are in a non-conductive state, the power path 80 is in a non-conductive state. When the switch 11 is in an on state, the second conductive path 85 and the third conductive path 86 are in a conductive state, and the power path 80 is in a conductive state. When the switch 11 is in the OFF state, there is no conduction between the second conductive path 85 and the third conductive path 86, and the power path 80 is in a non-conductive state. The switch 11 is controlled by a second control unit 92.

[0031] The interrupter 12 is configured as, for example, a pyrofuse (registered trademark), a semiconductor switch, an electromagnetic fuse, or the like. The interrupter 12 is provided in the power path 80 (more specifically, the conductive path 83). The interrupter 12 is arranged on the power path 80 (more specifically, the conductive path 83) closer to the power supply unit 90 than the switch 11. The interrupter 12 switches from a permissive state that allows power to be supplied from the power supply unit 90 side to the load 91 side on the power path 80 to a cutoff state that cuts off the power. The interrupter 12 is provided between the first conductive path 84 and the second conductive path 85. The interrupter 12 switches from a permissive state that allows power to be supplied from the first conductive path 84 side to the second conductive path 85 side to a cutoff state that cuts off the power. If the interrupter 12 is a pyrofuse (registered trademark), a semiconductor switch, or an electromagnetic fuse, it is likely to switch quickly to the cutoff state. The interrupter 12 may be configured to be able to return to an open state after being in the interrupted state, or may be configured not to be able to return to the open state. The interrupter 12 is controlled by the controller 14.

[0032] The current detection unit 13 is configured as, for example, a known current sensor. The current detection unit 13 detects the current flowing through the power path 80 (more specifically, the second conductive path 85). The current detection unit 13 outputs a signal that can identify the detected value. This signal is input to the control unit 14 and the second control unit 92, respectively.

[0033] The control unit 14 controls the breaker unit 12. The control unit 14 is configured as, for example, an MCU (Micro Controller Unit). The control unit 14 is configured as a device separate from the second control unit 92. The control unit 14 identifies the value of the current flowing through the power path 80 based on the signal output from the current detection unit 13. The control unit 14 switches the breaker unit 12 to the cut-off state when the value of the current flowing through the power path 80 exceeds a first threshold value Ith1.

[0034] The second control unit 92 controls the switch 11. The second control unit 92 is configured as, for example, an MCU (Micro Controller Unit). The second control unit 92 is disposed outside the housing 10. When a predetermined start condition is met, the second control unit 92 controls the switch 11 to switch the power path 80 to a conducting state. Specifically, the second control unit 92 switches the switch 11 to an ON state. The start condition is, for example, that a start switch of the vehicle has been switched to an ON state. When a predetermined stop condition is met, the second control unit 92 controls the switch 11 to switch the power path 80 to a non-conducting state. Specifically, the second control unit 92 switches the switch 11 to an OFF state. The stop condition is, for example, that a start switch of the vehicle has been switched to an OFF state. When a predetermined cut-off condition is met, the second control unit 92 controls the switch 11 to switch the power path 80 to a non-conducting state. Specifically, the second control unit 92 switches the switch 11 to the OFF state. The interruption condition is, for example, a condition that can be met based on the value of the current flowing through the power path 80. For example, the condition that can be met based on the value of the current flowing through the power path 80 is a condition that the value of the current flowing through the power path 80 exceeds a reference value. The second control unit 92 identifies the value of the current flowing through the power path 80 based on the signal output from the current detection unit 13.

[0035] Depending on the performance of the switch 11, there is a risk that the switch 11 will be unable to maintain a conducting state due to an increase in the current value flowing through the power path 80 before the interruption condition is met and the second control unit 92 switches the switch 11 to the off state. Therefore, the first threshold value Ith1 is set to a value smaller than the second threshold value Ith2, which is the maximum current value at which the switch 11 can maintain the power path 80 in a conducting state. This makes it easier for the control unit 14 to switch the interrupter 12 to the interrupting state before the switch 11 can no longer maintain the power path 80 in a conducting state. Therefore, even if the second threshold value is reduced by suppressing an increase in the size of the switch 11, a current exceeding the second threshold value Ith2 is less likely to flow through the switch 11. As a result, it is easier to avoid a situation in which the switch 11 is unable to maintain the power path 80 in a conducting state. Therefore, this configuration makes it possible to suppress an increase in the size of the switch 11 while preventing the switch 11 from malfunctioning.

[0036] The switch 11 is an electromagnetic relay. When the current flowing through the power line 80 flows into the electromagnetic relay, on From the state off An electromagnetic repulsive force is generated to change the state of the electromagnetic relay to the ON state. This electromagnetic repulsive force increases as the magnitude of the current flowing into the electromagnetic relay increases. When the current flowing into the electromagnetic relay exceeds the second threshold Ith2, the electromagnetic repulsive force becomes greater than the force maintaining the electromagnetic relay in the ON state, and the electromagnetic relay changes to the OFF state. When the electromagnetic relay changes to the OFF state, an arc may occur within the electromagnetic relay, causing the electromagnetic relay to malfunction. However, as described above, the first threshold Ith1 is set to a value smaller than the second threshold Ith2. Therefore, the control unit 14 can easily switch the breaker unit 12 to the OFF state before the switch 11, which is in the ON state, is switched to the OFF state by the electromagnetic repulsive force.

[0037] The second threshold value Ith2 is set to a value smaller than the saturation current IS that flows through the power path 80 when a ground fault occurs in the power path 80. The saturation current IS is the saturation current that occurs when a ground fault occurs at the second terminal 10B when the power supply unit 90 is fully charged and the in-vehicle system 100 is not deteriorated. According to this configuration, in order to prevent the switch 11 from becoming large, the switch 11 whose maximum current value that can maintain a conducting state is smaller than the saturation current IS can be used in the in-vehicle system 100. In addition, with this configuration, it is possible to prevent the switch 11 from malfunctioning.

[0038] The first threshold Ith1 is set in consideration of a time lag TL between when it is determined that the value of the current flowing through the power path 80 exceeds the first threshold Ith1 and when the breaker 12 switches to the cutoff state, so that the breaker 12 switches to the cutoff state before the value of the current flowing through the power path 80 reaches the saturation current IS. The first threshold Ith1 is set, for example, based on the time lag TL and correspondence data (see FIG. 2) that indicates the correspondence relationship between the time elapsed since the ground fault and the value of the current flowing through the power path 80.

[0039] The time lag TL is generated by the time from when the control unit 14 determines that the first threshold Ith1 has been exceeded until when the control unit 14 starts control to switch the cutoff unit 12 to the cutoff state, and the time from when the control to switch the cutoff unit 12 to the cutoff state starts until the cutoff unit 12 switches to the cutoff state. The time lag TL can be obtained, for example, from test results or simulation results.

[0040] The corresponding data can be obtained, for example, from test results or simulation results. The test results or simulation results are, for example, results obtained when the second terminal 10B is grounded when the in-vehicle system 100 is not deteriorated and the power supply unit 90 is fully charged.

[0041] In the corresponding data shown in Figure 2, a ground fault occurs at time T0. Thereafter, the current value gradually increases over time. At time T4, the current value flowing through power path 80 reaches saturation current IS.

[0042] The timing at which it is determined that the current value flowing through power path 80 has reached saturation current IS may be, for example, when the time elapsed since the ground fault has occurred is three times the time constant τ, or when 1 ms has elapsed since the ground fault has occurred. The time constant τ is calculated, for example, using the following equation (1): Time constant τ=(L1+L2+L3) / (R1+R2+R3)...Equation (1) L1 is the internal inductance of the power supply unit 90. L2 is the inductance of the path between the power supply unit 90 and the second terminal 10B. L3 is the inductance of the ground fault location. R1 is the internal resistance value of the power supply unit 90. R2 is the resistance value of the path between the power supply unit 90 and the second terminal 10B. R3 is the resistance value of the ground fault location. Note that L3 and R3 may change depending on the type of ground fault, and may therefore be set to 0, for example.

[0043] For example, the current value corresponding to the timing T1 that does not reach the timing T4 even when the time lag TL is taken into consideration is set as the first threshold value Ith1. That is, the timing T1 at which the timing T2 after the time lag TL elapses is earlier than the timing T4 is identified, and the current value corresponding to this timing T1 is set as the first threshold value Ith1.

[0044] According to this configuration, the interrupter 12 can be switched to the interrupted state before the value of the current flowing through the power path 80 reaches the saturation current IS.

[0045] The first threshold Ith1 is set in consideration of the time lag TL between when it is determined that the current value flowing through the power path 80 exceeds the first threshold Ith1 and when the breaker 12 switches to the cut-off state, so that the breaker 12 switches to the cut-off state before the current value flowing through the power path 80 reaches the second threshold Ith2. The first threshold Ith1 is set based on, for example, the time lag TL and the corresponding data.

[0046] 2, the timing at which the value of the current flowing through the power path 80 reaches the second threshold value Ith2 is time T3. For example, the current value corresponding to time T1, which does not reach time T3 even when time lag TL is taken into account, is set as the first threshold value Ith1. In other words, time T1 is identified at which time T2 after time lag TL has elapsed is earlier than time T3, and the current value corresponding to this time T1 is set as the first threshold value Ith1.

[0047] According to this configuration, the breaker 12 can be switched to the interrupted state before the value of the current flowing through the power path 80 reaches the second threshold value Ith2. This prevents a situation in which a current exceeding the second threshold value Ith2 flows through the switch 11 and the switch 11 is unable to maintain the power path 80 in a conducting state.

[0048] The first threshold value Ith1 is set to a value greater than the third threshold value Ith3, which is the maximum current value that can flow through the power path 80 when the power path 80 is in a normal state. The normal state of the power path 80 refers to a state in which the power path 80 is not faulted to ground, and more specifically, a state in which the voltage value of the power path 80 is equal to or greater than a threshold voltage. The threshold voltage is a value greater than or equal to 0 V. The maximum current value that can flow through the power path 80 refers to, for example, the current that flows through the power path 80 when a load 91, such as a motor in a vehicle, is operated at maximum capacity when the power supply unit 90 is fully charged.

[0049] This configuration makes it easy to prevent the breaker unit 12 from being switched to the breaker state when the power path 80 is in a normal state.

[0050] <Other embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of features of the above-described or following embodiments is possible within a range that does not contradict. Furthermore, any feature of the above-described or following embodiments may be omitted unless explicitly stated as essential. Furthermore, the above-described embodiment may be modified as follows.

[0051] In the above embodiment, the second control unit 92 is configured to be arranged outside the tripping control device 1, but it may also be configured to be arranged inside the tripping control device 1. In other words, the second control unit 92 may be a part of the tripping control device 1.

[0052] It should be noted that the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope indicated by the claims or within the scope equivalent to the claims. [Explanation of symbols]

[0053] 1:Shut-off control device 10: Housing 10A: 1st terminal part 10B: 2nd terminal part 11: Switch 12: Breaking section 13: Current detection section 14: Control section 80: Power line 81: 1st wiring section 82: 2nd wiring section 83: Conductive path 84: First conductive path 85: Second conductive path 86: Third conductive path 90: Power supply section 91: Load 92: Second control section 100: In-vehicle systems IS: Saturation current Ith1: First threshold Ith2: Second threshold Ith3: Third threshold

Claims

1. A power supply unit; a power path that is a path through which power is transmitted between the power supply unit and a load; a switch provided on the power path and configured to switch the power path between a conducting state and a non-conducting state; a cutoff unit that switches from a permissive state that allows power to be supplied from the power supply unit side to the load side in the power path to a cutoff state that cuts off the power; A shut-off control device used in an in-vehicle system comprising: a control unit that switches the interrupter to the interrupted state when a value of a current flowing through the power path exceeds a first threshold; the first threshold is smaller than a second threshold, which is a maximum current value at which the switch can maintain the power path in the energized state; the second threshold value is smaller than a saturation current that flows through the power line when a ground fault occurs in the power line; The first threshold value is set in consideration of a time lag between when it is determined that the value of the current flowing through the power path has exceeded the first threshold value and when the breaker unit switches to the cut-off state, so that the breaker unit switches to the cut-off state before the value of the current flowing through the power path reaches the saturation current. Shut-off control device.

2. The first threshold value is set in consideration of a time lag between when it is determined that the value of the current flowing through the power path exceeds the first threshold value and when the breaker unit switches to the cut-off state, so that the breaker unit switches to the cut-off state before the value of the current flowing through the power path reaches the second threshold value. The shutoff control device according to claim 1 .

3. A power supply unit; a power path that is a path through which power is transmitted between the power supply unit and a load; a switch provided on the power path and configured to switch the power path between a conducting state and a non-conducting state; a cutoff unit that switches from a permissive state that allows power to be supplied from the power supply unit side to the load side in the power path to a cutoff state that cuts off the power; A shut-off control device used in an in-vehicle system comprising: a control unit that switches the interrupter to the interrupted state when a value of a current flowing through the power path exceeds a first threshold; the first threshold is smaller than a second threshold, which is a maximum current value at which the switch can maintain the power path in the energized state; The first threshold value is set in consideration of a time lag between when it is determined that the value of the current flowing through the power path exceeds the first threshold value and when the breaker unit switches to the cut-off state, so that the breaker unit switches to the cut-off state before the value of the current flowing through the power path reaches the second threshold value. Shut-off control device.

4. The second threshold value is smaller than a saturation current that flows through the power line when the power line has a ground fault. The shutoff control device according to claim 3 .

5. The switch is an electromagnetic relay, and when the switch itself is in an on state, the power path is in the energized state, and when the switch itself is in an off state, the power path is in the non-energized state, and when a current greater than the second threshold flows through the switch itself, the on state is canceled by electromagnetic repulsion and the switch is switched to the off state. The shutoff control device according to any one of claims 1 to 4.

6. The first threshold is greater than a third threshold, which is a maximum current value that can flow through the power path in a normal state of the power path. The shutoff control device according to any one of claims 1 to 4.

7. The interrupter uses any one of a pyro-fuse, a semiconductor switch, and an electro-magnetic fuse. The shutoff control device according to any one of claims 1 to 4.

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