In-vehicle control device

Abstract

This vehicle-mounted control device (60) is used in an in-vehicle system (100) and controls a charging operation performed by a charging unit (20) and a discharging operation performed by a discharging unit (30). The vehicle-mounted control device (60) comprises a control unit (61) that controls the charging unit (20) and the discharging unit (30). The control unit (61) is able to execute a first control that, while causing the charging unit (20) to perform the charging operation, causes the discharging unit (30) to perform the discharging operation, and a second control that, without causing the charging unit (20) to perform the charging operation, causes the discharging unit (30) to perform the discharging operation. The control unit (61) executes the first control when the voltage in a power path (80) satisfies a voltage condition of being at most a failure determination voltage and does not satisfy a failure determination condition that is different from the voltage condition.

Description

Technical Field

[0001] The present disclosure relates to an in-vehicle control device.

Background Art

[0002] Patent Document 1 discloses a power supply device having a backup function. This power supply device supplies power to a load circuit using the power provided from an AC-DC conversion power supply if the power supply unit (AC power supply) is operating, and supplies power to the load circuit using the power stored in a power storage unit (battery) when the power supply unit (AC power supply) is stopped.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an in-vehicle system that supplies power from a power supply unit to a load in a vehicle, it is desirable to immediately supply power from a power storage unit different from the power supply unit at the time of a power failure where the power supply from the power supply unit stops. For this purpose, it is desirable to supply power from the power storage unit as soon as possible when the possibility of a power failure increases. However, if a method of supplying power from the power storage unit early when the power failure is not confirmed is adopted, although the risk of power supply to the load being interrupted at the time of a power failure can be suppressed, false determination due to noise or the like tends to increase the discharge from the power storage unit, and the charge amount of the power storage unit tends to decrease.

[0005] The present disclosure provides a technique that makes it easy to supply power to a load early at the time of a power failure and that easily suppresses a decrease in the charge level of the power storage unit.

Means for Solving the Problems

[0006] One of the on-vehicle control devices disclosed herein is a power supply unit, a power storage unit different from the power supply unit, a power path that is a path for supplying power from the power supply unit to a load, a charging unit that performs a charging operation of supplying a current to the power storage unit based on the power supplied from the power supply unit, and a discharging unit that performs a discharging operation of flowing a current to the load side based on the power supplied from the power storage unit, and is used in an on-vehicle system including: an on-vehicle control device that controls the charging operation by the charging unit and the discharging operation by the discharging unit, having a control unit that controls the charging unit and the discharging unit, the control unit is capable of executing a first control for causing the charging unit to perform the charging operation and causing the discharging unit to perform the discharging operation, and a second control for causing the discharging unit to perform the discharging operation without causing the charging unit to perform the charging operation, and executes the first control when a voltage condition that the voltage of the power path is equal to or lower than a fault determination voltage is satisfied and a fault determination condition different from the voltage condition is not satisfied.

Advantages of the Invention

[0007] The technology according to the present disclosure can easily supply power to a load at an early stage during a power supply failure, and can easily suppress a decrease in the charge level of the power storage unit.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] [Description of Embodiments of the Present Disclosure] Hereinafter, embodiments of the present disclosure will be listed and exemplified.

[0010] 〔1〕An in-vehicle system including a power supply unit, a power storage unit different from the power supply unit, a power path that is a path for supplying power from the power supply unit to a load, a charging unit that performs a charging operation of supplying a current to the power storage unit based on the power supplied from the power supply unit, and a discharging unit that performs a discharging operation of flowing a current to the load side based on the power supplied from the power storage unit, and an in-vehicle control device that controls the charging operation by the charging unit and the discharging operation by the discharging unit, having a control unit that controls the charging unit and the discharging unit, the control unit is capable of executing a first control for causing the charging unit to perform the charging operation and causing the discharging unit to perform the discharging operation, and a second control for causing the discharging unit to perform the discharging operation without causing the charging unit to perform the charging operation, and executes the first control when a voltage condition that the voltage of the power path is equal to or lower than a fault determination voltage is satisfied and a fault determination condition different from the voltage condition is not satisfied In-vehicle control device.

[0011] The in-vehicle control device described in [1] can discharge the power storage unit and supply power to the load earlier even if the defect determination condition is not satisfied when the voltage of the power line is equal to or lower than the defect determination voltage. Therefore, this in-vehicle control device can suppress the risk of power supply to the load being interrupted during a power supply failure. On the other hand, when the voltage of the power line is equal to or lower than the defect determination voltage, the charging operation by the charging unit can be continued without satisfying the defect determination condition. Therefore, even if the discharge of the power storage unit increases due to noise or the like, a decrease in the degree of charge of the power storage unit can be suppressed.

[0012] The defect determination condition includes that the time during which the voltage of the power line is equal to or lower than the defect determination voltage continues for a certain period of time. The control unit executes the second control when the time during which the voltage of the power line is equal to or lower than the defect determination voltage continues for the certain period of time. The in-vehicle control device described in [1].

[0013] The in-vehicle control device described in [2] can continue the charging operation by the charging unit without satisfying the defect determination condition when the voltage of the power line is equal to or lower than the defect determination voltage. Therefore, even if the discharge of the power storage unit increases due to noise or the like, a decrease in the degree of charge of the power storage unit can be suppressed. On the other hand, when the time during which the voltage of the power line is equal to or lower than the defect determination voltage continues for a certain period of time, that is, when the possibility of a power supply failure further increases, the in-vehicle control device executes the second control and stops the charging operation, thereby suppressing the influence caused by the state of the power line from reaching the power storage unit side due to the charging operation.

[0014] In [3], the in-vehicle system is provided with a switch unit in the power line. The charging unit supplies a current to the power storage unit based on the power supplied from the first power line on the power supply unit side of the switch unit in the power line. The discharging unit performs the discharging operation so as to pass a current through the second power line on the load side of the switch unit in the power line. When the switch unit is in the on state, energization between the first power path and the second power path is permitted bidirectionally. When the switch unit is in the off state, energization from at least the second power path to the first power path is blocked. After the control unit satisfies the voltage condition, the power path voltage is kept in the off state until a certain time has elapsed since the time when the voltage of the power path has been below the dropout determination voltage. After the control unit satisfies the voltage condition, the power path voltage is turned on on the condition that the voltage of the power path exceeds the dropout determination voltage before the certain time has elapsed since the time when the voltage of the power path has been below the dropout determination voltage. After the control unit satisfies the voltage condition, the power path voltage is turned off to stop the charging operation when the certain time has elapsed since the time when the voltage of the power path has been below the dropout determination voltage. The in-vehicle control device according to [2].

[0015] In the in-vehicle control device according to [3], when the voltage of the power path becomes lower than the dropout determination voltage, the switch unit can be kept in the off state so that no current flows from the second power path to the first power path until a certain time has elapsed since the time when the voltage has been below the dropout determination voltage. Therefore, if the voltage of the power path has become lower than the dropout determination voltage due to a power supply dropout, it is possible to surely block the discharge current from flowing back into the first power path while supplying the discharge current from the power storage unit to the load. On the other hand, after the in-vehicle control device satisfies the voltage condition, the in-vehicle control device can return to supplying power from the power supply unit to the load by switching the switch unit to the on state on the condition that the voltage of the power path exceeds the dropout determination voltage again before the certain time has elapsed since the time when the voltage of the power path has been below the dropout determination voltage. Therefore, even when the voltage of the power path temporarily becomes lower than the dropout determination voltage due to noise or the like, if the voltage returns quickly, the device can quickly return to normal operation. And even if the discharge operation based on such a temporary voltage drop is repeated, the charging operation is likely to be performed each time, so that a decrease in the degree of charge of the power storage unit can be suppressed. Furthermore, after the in-vehicle control device satisfies the voltage condition, the power path voltage is turned off to stop the charging operation when the certain time has elapsed since the time when the voltage of the power path has been below the dropout determination voltage. After the control unit satisfies the voltage condition, the power path voltageWhen the time during which the voltage is below the fault determination voltage has elapsed for a certain period of time, the switch unit is turned off to stop the charging operation. Therefore, when the possibility of power supply failure further increases, while suppressing the influence caused by the state of the first power path from reaching the second power path side, the discharge current based on the power storage unit can be supplied to the load.

[0016] 〔4〕The fault determination condition includes that a current flows from the charging unit side to the power path side. When a current flows from the charging unit side to the power path side, the control unit executes the second control. The in-vehicle control device according to 〔1〕.

[0017] In the in-vehicle control device according to 〔4〕, when the voltage of the power path is below the fault determination voltage, if the fault determination condition is not satisfied, the charging operation by the charging unit can be continued. Therefore, even if the discharge of the power storage unit increases due to noise or the like, the decrease in the charging degree of the power storage unit can be suppressed. On the other hand, when a current flows from the charging unit side to the power path side, the above in-vehicle control device executes the second control and stops the charging operation, thereby suppressing the influence caused by the state of the power path from reaching the power storage unit side due to the charging operation. For example, when a ground fault occurs in the power path and the voltage of the power path becomes below the fault determination voltage due to the ground fault, there is a concern that a large current will flow into the ground fault location if the charging operation is continued. However, if the second control is executed when a current flows from the charging unit side to the power path side, such a problem is less likely to occur.

[0018] 〔5〕The in-vehicle system is provided with a switch unit in the power path. The charging unit supplies a current to the power storage unit based on the power supplied from the first power path on the power supply unit side of the switch unit in the power path. The discharging unit performs the discharging operation so that a current flows through the second power path on the load side of the switch unit in the power path. When the switch unit is in the on state, energization between the first power path and the second power path is allowed bidirectionally. When the switch unit is in the off state, at least energization from the second power path to the first power path is blocked. The control unit executes the first control on the condition that the voltage condition is satisfied and no current flows from the charging unit side to the power path side. When the voltage condition is satisfied and current flows from the charging unit side to the power path side, the control unit executes the second control while keeping the switch unit in the off state. The in-vehicle control device according to [4].

[0019] When the voltage of the power path becomes equal to or lower than the fault determination voltage, the in-vehicle control device according to [5] executes the first control on the condition that no current flows from the charging unit side to the power path side. Therefore, when the voltage of the power path becomes equal to or lower than the fault determination voltage, the charging operation can be performed after confirming that the possibility of a ground fault is low. On the other hand, when current flows from the charging unit side to the power path side when the voltage of the power path becomes equal to or lower than the fault determination voltage, that is, when the possibility of a ground fault is high, the switch unit is turned off and the second control is executed to supply the discharge current based on the power storage unit to the load while preventing current from flowing from the second power path to the first power path.

[0020] 〔6〕The fault determination condition includes that the voltage of the power path becomes equal to or lower than a reference voltage that is lower than the fault determination voltage. The control unit executes the second control when the voltage becomes equal to or lower than the reference voltage. The in-vehicle control device according to [1].

[0021] The in-vehicle control device described in [6] can continue the charging operation by the charging unit without satisfying the fault determination condition when the voltage of the power line is equal to or lower than the fault determination voltage. Therefore, even if the discharge of the power storage unit increases due to noise or the like, it is possible to suppress a decrease in the charging degree of the power storage unit. On the other hand, since the in-vehicle control device can stop the charging operation and perform the discharging operation when the voltage of the power line becomes equal to or lower than the reference voltage that is smaller than the fault determination voltage, when the possibility of power supply failure is higher, it is possible to suppress the influence caused by the state of the power line from reaching the power storage unit side due to the charging operation.

[0022] <First Embodiment> 1. Overview of In-Vehicle System FIG. 1 shows an in-vehicle system 100. The in-vehicle system 100 shown in FIG. 1 mainly includes an in-vehicle power supply system 3 and a load 11. The in-vehicle power supply system 3 is also referred to as the power supply system 3 in the following description. The in-vehicle system 100 is a system that supplies power to the load 11 by the power supply system 3 and operates the load 11. In FIG. 1, the load 11 is exemplified as an example of an in-vehicle load, but other loads may be provided in the in-vehicle system 100.

[0023] The load 11 is an electrical component mounted on the vehicle. The load 11 operates by receiving the power supplied via the power line 80. The type of the load 11 is not limited. As the load 11, various known in-vehicle components can be adopted. The load 11 may have a plurality of electrical components or may be a single electrical component. The load 11 is a load that is required to operate even when the power supply from the power supply unit 10 to itself is interrupted. For example, it is a load that performs an operation necessary for the vehicle to stop (shift-by-wire control system, electronic control brake system, etc.).

[0024] The power supply system 3 is a system that supplies power to the load 11. The power supply system 3 supplies power to the load 11 using the power supply unit 10 or the power storage unit 13 as a power supply source. The power supply system 3 can supply power from the power supply unit 10 to the load 11. For example, when the power supply from the power supply unit 10 is interrupted due to a failure or the like, the power supply system 3 can supply power from the power storage unit 13 to the load 11.

[0025] 2. Overview of the power supply system The power supply system 3 includes a power supply unit 10, a power storage unit 13, a charging unit 20, a discharging unit 30, an in-vehicle control device 60, a power path 80, a first switch unit 12, a first voltage detection unit 51, a second voltage detection unit 52, a third voltage detection unit 53, conductive paths 83, 84, and the like.

[0026] The power supply unit 10 is an in-vehicle power supply that supplies power to the load 11 and functions as a main power supply for supplying power to the load 11. The power supply unit 10 is configured as a known in-vehicle battery such as a lead battery, for example. The power supply unit 10 may be configured by a battery other than a lead battery, and may have power supply means other than a battery instead of or in addition to the battery. The positive electrode of the power supply unit 10 is electrically connected to the first power path 81, which is a part of the power path 80, in a configuration short-circuited to the first power path 81. The negative electrode of the power supply unit 10 is electrically connected to the ground in a configuration short-circuited to the ground. The power supply unit 10 applies a DC voltage of a constant value to the first power path 81. The voltage applied by the power supply unit 10 to the first power path 81 may vary slightly from the above constant value.

[0027] The power storage unit 13 is a power source different from the power supply unit 10. The power storage unit 13 is a power source that serves as a power supply source at least when the power supply from the power supply unit 10 is interrupted, and functions as a backup power source that supplies power to the load 11 when the power supply based on the power supply unit 10 is insufficient. The power storage unit 13 is configured by known power storage means such as an electric double layer capacitor (EDLC), for example. The power storage unit 13 may be configured by a capacitor other than the electric double layer capacitor, or may be provided with other power storage means (such as a battery) instead of or in addition to the capacitor. The positive electrode of the power storage unit 13 is electrically connected to the conductive path 83 in a configuration short-circuited to the conductive path 83. The negative electrode of the power storage unit 13 is electrically connected to the ground in a configuration short-circuited to the ground. The output voltage of the power storage unit 13 (the voltage applied to the conductive path 83 by the power storage unit 13) may be greater than or less than the output voltage of the power supply unit 10 (the voltage applied to the first power path 81 by the power supply unit 10).

[0028] In this specification, unless otherwise particularly limited, the voltage is the voltage with respect to the ground potential (for example, 0V) and is the potential difference from the ground potential. For example, the voltage applied to the first power path 81 is the potential difference between the potential of the first power path 81 and the ground potential. The voltage applied to the conductive path 83 is the potential difference between the potential of the conductive path 83 and the ground potential.

[0029] The power path 80 is a path through which the power based on the power supply unit 10 is transmitted, and is a path for supplying power from the power supply unit 10 to the load 11. In the example of FIG. 1, the power path 80 includes a first power path 81 provided on the power supply unit 10 side of the first switch unit 12 and a second power path 82 provided on the load 11 side of the first switch unit 12. The first power path 81 is a power path on the power supply unit 10 side of the first switch unit 12 (switch unit) in the power path 80. A voltage identical or substantially identical to the output voltage of the power supply unit 10 is applied to the first power path 81. One end of the first power path 81 is electrically connected to the positive electrode in a configuration short-circuited to the positive electrode of the power supply unit 10. The other end of the first power path 81 is electrically connected to one end of the first switch unit 12. A relay or a fuse may be provided in the first power path 81. The second power path 82 is a power path on the load 11 side of the first switch unit 12 (switch unit) in the power path 80. One end of the second power path 82 is electrically connected to the other end of the first switch unit 12. In the example of FIG. 1, the second power path 82 is short-circuited to one end of the load 11.

[0030] The first switch unit 12 is composed of, for example, one or more FETs (Field Effect Transistors). The first switch unit 12 corresponds to an example of the "switch unit". The first switch unit 12 is provided in the power path 80. The first switch unit 12 may be composed of FETs arranged in opposite directions to each other, or may be composed of other semiconductor switches that cut off energization in both directions. In this case, when the first switch unit 12 is in the on state, it allows energization between the first power path 81 and the second power path 82 in both directions, and when it is in the off state, it cuts off energization between the first power path 81 and the second power path 82 in both directions. The first switch unit 12 may be composed of a single FET having a parasitic diode with its anode connected to the first power path 81 and its cathode connected to the second power path 82. In this case, when the first switch unit 12 is in the on state, it allows energization between the first power path 81 and the second power path 82 in both directions, and when it is in the off state, it blocks current from flowing from the second power path 82 to the first power path 81 through itself, and allows current to flow from the first power path 81 to the second power path 82. In any case, when the first switch unit 12 is in the off state, current flow from the second power path 82 to the first power path 81 is blocked.

[0031] The charging unit 20 is provided between the first power path 81 and the power storage unit 13. The charging unit 20 performs a charging operation of supplying a current to the power storage unit 13 based on the power supplied from the power supply unit 10 via the first power path 81. In the example of FIG. 1, the charging unit 20 includes a second switch unit 21 and a resistance unit 22. The second switch unit 21 may be configured by two FETs (Field Effect Transistors) arranged in opposite directions to each other, or may be configured by other semiconductor switches capable of blocking energization in both directions. The resistance unit 22 is configured as, for example, a known resistor. In the example of FIG. 1, the second switch unit 21 and the resistance unit 22 are connected in series with each other. The second switch unit 21 is arranged closer to the power supply unit 10 than the resistance unit 22. When the charging operation is performed such that the second switch unit 21 is turned on when the charging voltage of the power storage unit 13 is lower than the voltage of the first power path 81, a charging current flows from the first power path 81 to the power storage unit 13. When the second switch unit 21 is in the off state, charging stops, no current flows from the first power path 81 to the conduction path 83, and no current flows from the conduction path 83 to the first power path 81. In a representative example of the present embodiment, the output voltage applied to the first power path 81 when the power supply unit 10 is fully charged is greater than the output voltage applied to the conduction path 83 when the power storage unit 13 is fully charged.

[0032] The discharge unit 30 is provided between the power storage unit 13 and the second power path 82. The discharge unit 30 performs a discharging operation to cause a current to flow to the load 11 side via the second power path 82 based on the power supplied from the power storage unit 13. The discharge unit 30 includes a conductive path 31, a voltage conversion circuit 32, and a cutoff unit 14. The conductive path 31 is a conductive path that forms a path for supplying a discharge current to the load 11 side. One end of the conductive path 31 can be electrically connected to the second power path 82 via a conductive path 84 described later. One end of the voltage conversion circuit 32 is electrically connected to the power storage unit 13 via a conductive path 83 and is short-circuited to the positive electrode of the conductive path 83 and the power storage unit 13. The other end of the voltage conversion circuit 32 is electrically connected in a short-circuited form to the other end of the conductive path 31. The voltage conversion circuit 32 performs a voltage conversion operation to boost or step down the input voltage based on the power storage unit 13 and apply the output voltage to the conductive path 31. The voltage conversion circuit 32 is, for example, a DC-DC converter (e.g., a step-up type DC-DC converter), and boosts the input voltage based on the power storage unit 13 (specifically, the voltage of the conductive path 83) and applies the output voltage to the conductive path 31. The discharge unit 30 performs a discharging operation when the voltage conversion circuit 32 performs a voltage conversion operation, and stops the discharging operation when the voltage conversion circuit 32 stops the voltage conversion operation.

[0033] The conductive path 84 is provided between the second power path 82 and the discharge unit 30. The cutoff unit 14 is provided between the conductive path 84 and the conductive path 31. The cutoff unit 14 may be configured by, for example, FETs arranged in opposite directions to each other, or may be configured by other semiconductor switches that block energization in both directions. In this case, when the cutoff unit 14 is in the on state, it allows energization between the second power path 82 and the conductive path 31 (specifically, energization between the second power path 82 and the voltage conversion circuit 32) in both directions, and when the cutoff unit 14 is in the off state, it blocks energization between the second power path 82 and the conductive path 31 in both directions.

[0034] In a representative example, the cutoff unit 14 is configured to block energization in both directions when it is in the off state. In this example, the cutoff unit 14 switches between a cutoff state (off state) that blocks current from flowing from the conductive path 31 to the second power path 82 via itself and a permitted state (on state) that permits it.

[0035] The first voltage detection unit 51, the second voltage detection unit 52, and the third voltage detection unit 53 are each configured as a known voltage detection circuit. The first voltage detection unit 51 detects the voltage of the power path 80 (more specifically, the first power path 81), and gives a voltage signal capable of identifying the voltage of the power path 80 to the control unit 61. The second voltage detection unit 52 gives a voltage signal capable of identifying the voltage of the conductive path 83, that is, the output voltage of the power storage unit 13, to the control unit 61. The third voltage detection unit 53 gives a voltage signal capable of identifying the voltage of the conductive path 31 to the control unit 61.

[0036] The in-vehicle control device 60 is a device that controls the charging operation by the charging unit 20 and the discharging operation by the discharging unit 30. The in-vehicle control device 60 includes a control unit 61.

[0037] The control unit 61 is a device that controls the charging unit 20 and the discharging unit 30. In the representative example described below, the control unit 61 also controls the first switch unit 12 and the cutoff unit 14. The control unit 61 is configured as, for example, an MCU (Micro Controller Unit). Signals given from the first voltage detection unit 51, the second voltage detection unit 52, and the third voltage detection unit 53 are input to the control unit 61. The control unit 61 identifies the voltage of the power path 80 (more specifically, the first power path 81), the output voltage of the power storage unit 13, and the voltage of the conductive path 31 (that is, the output voltage of the discharging unit 30) based on these signals.

[0038] When the control unit 61 controls the charging unit 20, for example, it gives a PWM signal that periodically outputs an on signal for turning on the second switch unit 21 to the second switch unit 21 of the charging unit 20, and controls the duty of this PWM signal. Then, the control unit 61 adjusts the charging current supplied to the power storage unit 13 by adjusting the PWM signal given to the second switch unit 21. Note that the method for controlling the charging current by the control unit 61 is not limited to this example, and other known methods may be used.

[0039] The control unit 61 can cause the voltage conversion circuit 32 to perform a voltage conversion operation so that, for example, the voltage applied to the conductive path 31 is a target voltage.

[0040] The following description relates to the operation of the in-vehicle control device 60. When a predetermined start condition is satisfied, the control unit 61 starts backup support control as shown in FIG. 2. The start condition may be, for example, that the start switch of the vehicle on which the in-vehicle system 100 is mounted is switched from the off state to the on state. In this case, the start switch may be, for example, an ignition switch or a power switch provided in an electric vehicle. The start condition may be other than the above-described condition. For example, it may be that a predetermined signal is received from an external ECU (Electronic Control Unit), or other conditions.

[0041] When the control unit 61 starts the control of FIG. 2, it determines whether the voltage of the power path 80 (specifically, the voltage of the first power path 81) is equal to or lower than the low voltage threshold Vth1 in step S1. The low voltage threshold Vth1 corresponds to the first threshold. The low voltage threshold Vth1 is a value greater than 0V. The low voltage threshold Vth1 is a value smaller than the output voltage of the power supply unit 10 at full charge and greater than the defect determination voltage Vth2 described later.

[0042] When the control unit 61 determines in step S1 that the voltage of the first power path 81 is not equal to or lower than the low voltage threshold Vth1, the process proceeds to step S2. If the first switch unit 12 is in the on state immediately before the start of step S2, the control unit 61 maintains the on state of the first switch unit 12 in step S2. If the first switch unit 12 is in the off state immediately before the start of step S2, the control unit 61 turns on the first switch unit 12 in step S2. When the first switch unit 12 is in the on state when the voltage of the first power path 81 is not equal to or lower than the low voltage threshold Vth1, power can be supplied from the power supply unit 10 to the load 11.

[0043] After step S2, the control unit 61 advances the process to step S3. If the discharge by the discharge unit 30 has stopped immediately before the start of step S3, the control unit 61 maintains the discharge stop state in step S3. If the discharge by the discharge unit 30 is being performed immediately before the start of step S3, the control unit 61 switches to the discharge stop state in step S3. The discharge stop state is a state in which current is not supplied from the discharge unit 30 to the second power path 82. The discharge stop state may be a state in which the cutoff unit 14 is in the off state (cutoff state) while the voltage conversion circuit 32 is performing a voltage conversion operation to apply an output voltage to the conductive path 31. The discharge stop state may be a state in which the voltage conversion circuit 32 stops performing the voltage conversion operation and the conductive path 83 and the conductive path 31 are electrically disconnected.

[0044] After step S3, the control unit 61 advances the process to step S4 and determines whether a predetermined charging condition is satisfied. The charging condition is, for example, "the output voltage of the power storage unit 13 (the voltage of the conductive path 83) is equal to or less than the threshold voltage Vth4". The threshold voltage Vth4 corresponds to the fourth threshold. The threshold voltage Vth4 is a value greater than 0V. The threshold voltage Vth4 is preferably, for example, a value lower than the low voltage threshold Vth1. However, the threshold voltage Vth4 may be a value higher than the low voltage threshold Vth1 or may be the same as the low voltage threshold Vth1. Note that the charging condition is not limited to the above example, and may be, for example, "the voltage of the first power path 81 is higher than the voltage of the conductive path 83". In the representative example described below, "the voltage of the conductive path 83 is equal to or less than the threshold voltage Vth4" is the above charging condition, and the threshold voltage Vth4 is a value lower than the low voltage threshold Vth1.

[0045] When the control unit 61 determines in step S4 that the charging condition is satisfied, the process proceeds to step S5. When it determines that the charging condition is not satisfied, the process proceeds to step S6. If the charging operation state is the charging operation state immediately before the start of step S5, the control unit 61 maintains the charging operation state in step S5. If the charging operation state is the charging stop state immediately before the start of step S5, the control unit 61 sets the charging operation state in step S5. If the charging stop state is the charging stop state immediately before the start of step S6, the control unit 61 maintains the charging stop state in step S6. If the charging operation state is the charging operation state immediately before the start of step S6, the control unit 61 sets the charging stop state in step S6. In the example of FIG. 1, the charging operation state is a state in which the second switch unit 21 is maintained in the on state. The charging stop state is a state in which the second switch unit 21 is maintained in the off state. When the charging stop state is set in step S6, power can be supplied from the power supply unit 10 to the load 11 in a state where the charging operation has stopped as shown in FIG. 3. In the charging operation state, when the voltage of the first power path 81 is higher than the voltage of the conductive path 83, a charging current based on the power from the power supply unit 10 is supplied to the power storage unit 13. Therefore, when the charging operation state is set in step S5, when the voltage of the first power path 81 is higher than the voltage of the conductive path 83, as shown in FIG. 4, power can be supplied from the power supply unit 10 to the power storage unit 13 while power is supplied to the load 11. The control unit 61 returns the process to step S1 after step S5 or step S6.

[0046] When the control unit 61 determines in step S1 that the voltage of the first power path 81 is less than or equal to the low voltage threshold Vth1, the process proceeds to step S7. If the first switch unit 12 is in the off state immediately before the start of step S7, the control unit 61 maintains the off state of the first switch unit 12 in step S7. If the first switch unit 12 is in the on state immediately before the start of step S7, the control unit 61 turns off the first switch unit 12 in step S7.

[0047] After step S7, the control unit 61 proceeds with the process to step S8. If the discharge operation state is present immediately before the start of step S8, the control unit 61 maintains that discharge operation state in step S8. If the discharge by the discharge unit 30 has stopped immediately before the start of step S8, the control unit 61 switches to the discharge operation state in step S8. The discharge operation state is a state in which the discharge unit 30 performs a discharge operation, and is a state in which the discharge unit 30 supplies a discharge current to the second power path 82 based on the power from the power storage unit 13. Specifically, the discharge operation state is a state in which the cutoff unit 14 is in the on state and the voltage conversion circuit 32 performs voltage conversion so as to apply a target voltage to the conductive path 31. The target voltage may be the low voltage threshold Vth1, may be a value greater than the low voltage threshold Vth1, or may be a value less than the low voltage threshold Vth1. The above target voltage is, for example, a value greater than the defect determination voltage Vth2. If the above discharge operation state is present when the first switch unit 12 is maintained in the off state, a current is supplied from the voltage conversion circuit 32 to the second power path 82 based on the power supplied from the power storage unit 13.

[0048] After step S8, the control unit 61 proceeds with the process to step S9 and determines whether the above charging condition is satisfied. If the control unit 61 determines in step S9 that the above charging condition is satisfied, the process proceeds to step S10. If it determines that the above charging condition is not satisfied, the process proceeds to step S11. If the control unit 61 is in the charging operation state immediately before the start of step S10, it maintains the charging operation state in step S10. If it is in the charging stop state immediately before the start of step S10, it sets the charging operation state in step S10. If the control unit 61 is in the charging stop state immediately before the start of step S11, it maintains the charging stop state in step S11. If it is in the charging operation state immediately before the start of step S11, it sets the charging stop state in step S11. Thus, in the representative example, when the voltage of the power path 80 (more specifically, the first power path 81) is equal to or lower than the low voltage threshold Vth1, the control unit 61 causes the discharging unit 30 to perform a discharging operation. When the output voltage of the power storage unit 13 (the voltage of the conductive path 83) is equal to or lower than the threshold voltage Vth4, the control unit 61 causes the charging unit 20 to perform a charging operation. The control for the control unit 61 to cause the charging unit 20 to perform a charging operation while causing the discharging unit 30 to perform a discharging operation corresponds to an example of the first control. When setting the charging operation state in step S10, if the voltage of the first power path 81 is higher than the voltage of the conductive path 83, as shown in FIG. 5, power can be supplied from the power supply unit 10 to the power storage unit 13 side while power is supplied to the load 11 based on the power from the power storage unit 13 side.

[0049] When the control unit 61 sets the discharge operation state in step S8 and the charge operation state in step S10, during the period when the discharge operation by the discharge unit 30 and the charge operation by the charge unit 20 are performed in parallel, the control unit 61 controls so that the power supplied by the charge unit 20 to the power storage unit 13 is equal to or greater than the power supplied by the discharge unit 30 by discharge. The specific control method is not limited. For example, the control unit 61 may calculate the power per unit time supplied by the discharge unit 30 by discharge, and cause the charge unit 20 to perform a charge operation so that the power per unit time supplied by the charge unit 20 to the power storage unit 13 is equal to or greater than the calculated value. The "power per unit time supplied by the discharge unit 30 by discharge" may be calculated based on, for example, the voltage of the conductive path 31 and the current flowing through the conductive path 31. The "power per unit time supplied by the charge unit 20 to the power storage unit 13" may be calculated based on, for example, the voltage of the path between the charge unit 20 and the conductive path 83 and the current flowing through that path.

[0050] After step S10 or step S11, the control unit 61 advances the process to step S12, and in step S12, determines whether or not the voltage of the power path 80 (specifically, the voltage of the first power path 81) is equal to or lower than the defect determination voltage Vth2. The defect determination voltage Vth2 corresponds to the second threshold value. The defect determination voltage Vth2 is a value greater than 0V. The defect determination voltage Vth2 is a value smaller than the low voltage threshold Vth1. The defect determination voltage Vth2 is a value smaller than the threshold voltage Vth4. If the control unit 61 determines in step S12 that the voltage of the first power path 81 is equal to or lower than the defect determination voltage Vth2, the process advances to step S13, and if it determines that the voltage of the first power path 81 is not equal to or lower than the defect determination voltage Vth2, the process returns to step S1.

[0051] When the control unit 61 proceeds with the process to step S13, it determines whether or not the defect determination condition predetermined in step S13 is satisfied. The defect determination condition is, for example, "the time during which the voltage of the first power path 81 is equal to or less than the defect determination voltage Vth2 has continued for a certain period of time". When the control unit 61 determines in step S13 that the defect determination condition is satisfied, it proceeds with the process to step S14, and when it determines that the defect determination condition is not satisfied, it returns the process to step S1. In the present embodiment, when the voltage of the power path 80 (specifically, the voltage of the first power path 81) satisfies the voltage condition of being equal to or less than the defect determination voltage Vth2 and does not satisfy a defect determination condition different from the voltage condition (when it is determined as No in step S13), the first control is executed when the charging condition is satisfied. Specifically, the first control is performed when it is determined as Yes in step S12 immediately after step S10 and it is determined as No in step S13. When the first control is performed, power is supplied as shown in FIG. 5.

[0052] If the control unit 61 is in the charge stop state immediately before the start of step S14, it maintains the charge stop state in step S14, and if it is in the charge operation state immediately before the start of step S14, it sets the charge stop state in step S14. "Control to cause the discharge unit 30 to perform a discharge operation without causing the charging unit 20 to perform a charging operation" corresponds to an example of the second control. In a representative example, after the voltage of the first power path 81 satisfies the voltage condition of being equal to or less than the defect determination voltage Vth2, when the time during which the voltage of the first power path 81 is equal to or less than the defect determination voltage Vth2 has continued for a certain period of time, the control unit 61 executes the second control in step S14, stops the charging operation of the charging unit 20, causes the discharge unit 30 to perform a discharge operation, and maintains the first switch unit 12 in the off state. When the second control is thus performed in step S14, power is supplied from the storage unit 13 to the load 11 in a state where the power supply from the power supply unit 10 to the load 11 is stopped and the power supply from the power supply unit 10 to the storage unit 13 is stopped, as shown in FIG. 6.

[0053] Thus, in step S14, the control unit 61 performs control so as to stop the charging operation while performing the discharging operation, but in addition to or instead of stopping the charging operation, a notification signal may be output to an external device (e.g., an ECU other than the in-vehicle control device 60) to notify that the power supply unit 10 has failed. In this example, when the external device receives the notification signal, it may notify a person in the vehicle cabin of the abnormality (e.g., notify that a power supply failure has occurred) by voice or display.

[0054] In the representative example described above, after "the voltage condition that the voltage of the first power path 81 is equal to or lower than the failure determination voltage Vth2" is satisfied, the control unit 61 maintains the first switch unit 12 in the OFF state until a certain time has elapsed during which the voltage of the first power path 81 is equal to or lower than the failure determination voltage Vth2 (i.e., while the determinations of Yes in steps S1 and S12 and No in step S13 are repeated). Therefore, during the period during which there is a concern of a failure, the first power path 81 and the second power path 82 can be electrically disconnected.

[0055] In a representative example, the control unit 61 determines whether or not the first power path 81 is in a fault determination voltage Vth2 after the voltage condition is satisfied. voltage The first switch unit 12 is turned on on the condition that the voltage of the first power path 81 exceeds the failure determination voltage Vth2 before a certain period of time during which the voltage of the first power path 81 is equal to or less than the failure determination voltage Vth2 has elapsed. For example, if the voltage of the first power path 81 exceeds the low voltage threshold Vth1 while the determinations of Yes in steps S1 and S12 and No in step S13 are repeated, the first switch unit 12 is turned on in step S2. Therefore, even if the voltage of the first power path 81 temporarily falls below the failure determination voltage Vth2, if the voltage of the first power path 81 returns to exceeding the low voltage threshold Vth1 before the certain period of time has elapsed, normal operation can be restored.

[0056] The above description relates to the effects of the vehicle control device 60. When the voltage of the power path 80 is equal to or lower than the fault determination voltage Vth2, the in-vehicle control device 60 can discharge the power storage unit 13 and supply power to the load 11 earlier even if the fault determination condition is not satisfied. Therefore, this in-vehicle control device 60 can suppress the risk of power supply to the load 11 being interrupted during a power supply fault. On the other hand, when the voltage of the power path 80 is equal to or lower than the fault determination voltage Vth2, the charging operation by the charging unit 20 can be continued without satisfying the fault determination condition. Therefore, even if the discharge of the power storage unit 13 increases due to a temporary decrease in the voltage of the power path 80 caused by noise or the like, a decrease in the degree of charge of the power storage unit 13 can be suppressed.

[0057] When the time during which the voltage of the power path 80 is equal to or lower than the fault determination voltage Vth2 continues for a certain period, that is, when the possibility of a power supply fault further increases, the in-vehicle control device 60 executes second control and stops the charging operation, thereby suppressing the influence caused by the state of the power path 80 from reaching the power storage unit 13 side due to the charging operation. For example, when a ground fault occurs in the first power path 81 and the voltage drops below the fault determination voltage Vth2, if the charging operation time becomes too long, there is a concern that the energy stored in the power storage unit 13 will disappear due to discharge from the power storage unit 13 to the ground fault location. However, if the charging operation is stopped when the time during which the voltage is equal to or lower than the fault determination voltage Vth2 continues for a certain period, the subsequent discharge can be suppressed.

[0058] When the voltage of the first power path 81 becomes equal to or lower than the fault determination voltage Vth2, the in-vehicle control device 60 can keep the first switch unit 12 (switch unit) in the off state until a certain period of time has elapsed while the voltage is equal to or lower than the fault determination voltage Vth2, so that current does not flow from the second power path 82 to the first power path 81. Therefore, if the voltage of the first power path 81 has become equal to or lower than the fault determination voltage Vth2 due to a power supply fault, it is possible to surely block the discharge current from flowing back into the first power path 81 while supplying the discharge current from the power storage unit 13 to the load 11. On the other hand, after the in-vehicle control device 60 satisfies the above voltage condition, the first power path 81 voltageIf the voltage exceeds the dropout determination voltage Vth2 again before a certain time has elapsed while the time when the voltage is equal to or lower than the dropout determination voltage Vth2, the first switch unit 12 is switched to the ON state, and power can be supplied from the power supply unit 10 to the load 11 to return to the normal state. Therefore, even if the voltage of the first power path 81 temporarily drops below the dropout determination voltage Vth2 due to noise or the like, if the voltage returns quickly, the operation can quickly return to the normal operation state. And even if the discharge operation based on such a temporary voltage drop is repeated, since the charging operation is likely to be performed each time, a decrease in the degree of charge of the power storage unit 13 can be suppressed. Further, after the in - vehicle control device 60 satisfies the above voltage condition, the first power path 81 voltage When a certain time has elapsed while the voltage is equal to or lower than the dropout determination voltage, the first switch unit 12 is turned off to stop the charging operation. Therefore, when the possibility of power supply dropout further increases, while suppressing the influence caused by the state of the first power path 81 from reaching the second power path 82 side, the discharge current based on the power storage unit 13 can be supplied to the load 11.

[0059] <Second Embodiment> The in - vehicle control device 60 of the second embodiment is the same as the in - vehicle control device 60 of the first embodiment except for the dropout determination condition. The in - vehicle system 100 in which the in - vehicle control device 60 of the second embodiment is used is the same as the in - vehicle system 100 in which the in - vehicle control device 60 of the first embodiment is used except for the dropout determination condition, and has the configuration as shown in FIG. 1. Also, the backup - corresponding control performed by the control unit 61 of the in - vehicle control device 60 of the second embodiment is the same as the backup - corresponding control performed by the in - vehicle control device 60 of the first embodiment except for the specific determination method in step S13. Therefore, hereinafter, the in - vehicle control device 60 of the second embodiment will be described with reference to FIGS. 1 and 2.

[0060] When the control unit 61 performs the backup support control of FIG. 2, the in-vehicle control device 60 according to the second embodiment sets "current flowing from the charging unit 20 side to the power path 80 side" as the defect determination condition in step S13. That is, when the control unit 61 determines in step S13 that "current is flowing from the charging unit 20 side to the power path 80 side", it determines that the defect determination condition is satisfied in step S13 and advances the process to step S14. On the other hand, when the control unit 61 determines in step S13 that "no current is flowing from the charging unit 20 side to the power path 80 side", it determines that the defect determination condition is not satisfied in step S13 and returns the process to step S1. When the control unit 61 determines in step S13 that the defect determination condition is satisfied (that is, when current is flowing from the charging unit 20 side to the power path 80 side), the control unit 61 executes the above-described second control in step S14.

[0061] The determination as to whether or not current is flowing from the charging unit 20 side to the power path 80 side can be made in various ways. For example, when the second switch unit 21 is in the on state, the voltages at both ends of the resistor unit 22 are detected respectively, and when the voltage at the terminal on the first power path 81 side in the resistor unit 22 is lower than the voltage at the terminal on the conductive path 83 side, the control unit 61 may determine that "current is flowing from the charging unit 20 side to the power path 80 side". Alternatively, a current sensor may be provided in a configuration in which the current sensor is connected in series to the second switch unit 21 and the resistor unit 22 in a path in which the second switch unit 21 and the resistor unit 22 are provided in series. In this case, the control unit 61 may obtain the detection value of the current sensor and determine that "current is flowing from the charging unit 20 side to the power path 80 side" when a current of a certain value or more is flowing in the direction from the charging unit 20 to the first power path 81.

[0062] Also in the in-vehicle control device 60 according to the second embodiment, a first switch unit 12 (switch unit) is provided in the power path 80. The charging unit 20 supplies a current to the power storage unit 13 based on the power supplied from the first power path 81 (the power path on the power supply unit 10 side of the first switch unit 12 in the power path 80). Then, the discharging unit 30 performs a discharging operation so as to pass a current through the second power path 82 (the power path on the load 11 side of the first switch unit 12 in the power path 80). When the first switch unit 12 is in the on state, energization between the first power path 81 and the second power path 82 is allowed bidirectionally. When the first switch unit 12 is in the off state, at least the energization from the second power path 82 to the first power path 81 is blocked. It is desirable that the energization between the first power path 81 and the second power path 82 be blocked bidirectionally when the first switch unit 12 is in the off state. However, a configuration in which energization from the first power path 81 to the second power path 82 is allowed when the first switch unit 12 is in the off state may also be adopted.

[0063] In the second embodiment, the control unit 61 can execute the first control on the condition that the above-described voltage condition (the voltage condition that the voltage of the first power path 81 is equal to or lower than the failure determination voltage Vth2) is satisfied and no current flows from the charging unit 20 side to the power path 80 side. Specifically, after step S10, when the control unit 61 determines Yes in step S12 and No in step S13, the control unit 61 turns off the first switch unit 12 and executes the first control so as to cause the charging unit 20 to perform a charging operation and the discharging unit 30 to perform a discharging operation. On the other hand, when the voltage condition that the voltage of the first power path 81 is equal to or lower than the failure determination voltage Vth2 is satisfied and a current flows from the charging unit 20 side to the power path 80 side, the control unit 61 executes the second control while turning off the first switch unit 12. Specifically, when the control unit 61 determines Yes in step S12 and Yes in step S13, the control unit 61 turns off the first switch unit 12 and executes the second control so as to cause the discharging unit 30 to perform a discharging operation without causing the charging unit 20 to perform a charging operation.

[0064] When the voltage of the first power path 81 is equal to or lower than the fault determination voltage Vth2, the in-vehicle control device 60 according to this embodiment can continue the charging operation by the charging unit 20 without satisfying the fault determination condition. Therefore, even if the discharge of the power storage unit 13 increases due to noise or the like, it is possible to suppress a decrease in the charging degree of the power storage unit 13. On the other hand, when the voltage of the first power path 81 is equal to or lower than the fault determination voltage Vth2, the in-vehicle control device 60 executes the second control and stops the charging operation when a current flows from the charging unit 20 side to the power path 80 side. By such control, the in-vehicle control device 60 can suppress the influence caused by the state of the power path 80 from reaching the power storage unit 13 side due to the charging operation. For example, when a ground fault occurs in the power path 80 and the voltage of the power path 80 becomes equal to or lower than the fault determination voltage Vth2 due to the ground fault, there is a concern that a large current will flow into the ground fault location if the charging operation is continued. However, if the second control is executed when a current flows from the charging unit 20 side to the power path 80 side, such a problem is less likely to occur.

[0065] When the voltage of the first power path 81 becomes equal to or lower than the fault determination voltage Vth2, the in-vehicle control device 60 of this embodiment executes the first control on the condition that no current flows from the charging unit 20 side to the power path 80 side. Therefore, when the voltage of the first power path 81 becomes equal to or lower than the fault determination voltage Vth2, it is possible to perform the charging operation after confirming that the possibility of a ground fault is low. On the other hand, when a current flows from the charging unit 20 side to the power path 80 side when the voltage of the first power path 81 becomes equal to or lower than the fault determination voltage Vth2, that is, when the possibility of a ground fault is high, the first switch unit 12 is turned off and the second control is executed to prevent the current from flowing from the second power path 82 into the first power path 81 and from the power storage unit 13 into the first power path 81, and at the same time, the discharge current based on the power storage unit 13 can be supplied to the load 11.

[0066] <Third Embodiment> The in-vehicle control device 60 of the third embodiment is the same as the in-vehicle control device 60 of the first embodiment except for the fault determination conditions. The in-vehicle system 100 in which the in-vehicle control device 60 of the third embodiment is used is the same as the in-vehicle system 100 in which the in-vehicle control device 60 of the first embodiment is used except for the fault determination conditions, and has the configuration as shown in FIG. 1. Further, the backup response control performed by the control unit 61 of the in-vehicle control device 60 of the third embodiment is the same as the backup response control performed by the in-vehicle control device 60 of the first embodiment except for the specific determination method in step S13. Therefore, hereinafter, the in-vehicle control device 60 of the third embodiment will be described with reference to FIGS. 1 and 2.

[0067] When the control unit 61 of the in-vehicle control device 60 of the third embodiment performs the backup response control of FIG. 2, the in-vehicle control device 60 sets "the voltage of the first power path 81 has become equal to or lower than a reference voltage Vth3 which is lower than the fault determination voltage Vth2" as the fault determination condition in step S13. The reference voltage Vth3 corresponds to the third threshold value. The reference voltage Vth3 is a value greater than 0. The reference voltage Vth3 is a value smaller than the threshold voltage Vth4. When the control unit 61 determines in step S13 that "the voltage of the first power path 81 is equal to or lower than the reference voltage Vth3", it determines that the fault determination condition is satisfied in step S13, and advances the process to step S14. On the other hand, when the control unit 61 determines in step S13 that "the voltage of the first power path 81 is greater than the reference voltage Vth3", it determines that the fault determination condition is not satisfied in step S13, and returns the process to step S1. When the control unit 61 determines in step S13 that the fault determination condition is satisfied (that is, when the voltage of the first power path 81 is equal to or lower than the reference voltage Vth3), it executes the above-described second control in step S14, and causes the discharge unit 30 to perform a discharge operation without causing the charging unit 20 to perform a charging operation.

[0068] <Other Embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, the features of the above-described or below-described embodiments can be combined in any non-conflicting manner. Also, any feature of the above-described or below-described embodiments can be omitted if it is not explicitly specified as essential. Furthermore, the above-described embodiments may be modified as follows.

[0069] In the above-described embodiment, the control unit 61 executes the first control when the charging condition described above is satisfied in a case where the voltage of the power path 80 satisfies the voltage condition that the voltage is less than or equal to the voltage drop determination voltage Vth2 and does not satisfy a voltage drop determination condition different from the voltage condition. However, the first control may always be executed in a case where the voltage condition is satisfied and the voltage drop determination condition is not satisfied.

[0070] In the above-described embodiment, the in-vehicle control device 60 includes at least the control unit 61, but the in-vehicle control device 60 may be configured to include the entire power system 3.

[0071] In the above-described embodiment, the power system 3 includes the power supply unit 10 and the power storage unit 13. However, even in the above-described embodiment, when the in-vehicle control device 60 is configured to include the entire power system 3, the power system 3 may be changed to a configuration in which only the power supply unit 10 is removed from the configuration of the above-described power system 3, may be changed to a configuration in which only the power storage unit 13 is removed from the configuration of the above-described power system 3, or may be changed to a configuration in which both the power supply unit 10 and the power storage unit 13 are removed from the configuration of the above-described power system 3.

[0072] In the above-described embodiment, as an example of the blocking unit 14, a switching element having a predetermined structure that switches between a state allowing bidirectional energization and a state blocking bidirectional energization is exemplified, but the present invention is not limited to this example. For example, the blocking unit 14 in FIG. 1 may be constituted by a single FET having a parasitic diode whose anode is connected so as to short-circuit the conductive path 31 and whose cathode is connected so as to short-circuit the second power path 82. Alternatively, the blocking unit 14 in FIG. 1 may be changed to a diode that is electrically connected such that the anode is short-circuited to the conductive path 31 and the cathode is electrically connected such that it is short-circuited to the conductive path 84.

[0073] In the above-described embodiment, the first switch unit 12 is exemplified as an example of the element provided in the power path 80. However, the first switch unit 12 may be changed to another type of element that can block the flow of current from the load 11 side to the power supply unit 10 side. For example, in the configuration of FIG. 1, the first switch unit 12 may be changed to a diode. In this case, the anode of the diode may be electrically connected so as to short-circuit the first power path 81, and the cathode may be electrically connected so as to short-circuit the second power path 82.

[0074] In the above-described embodiment, the charging unit 20 has a configuration including the second switch unit 21 and the resistance unit 22, but it may have another configuration. For example, the charging unit 20 may be constituted by a voltage conversion circuit (for example, a DC-DC converter). In this case, the voltage conversion circuit may perform a boosting operation or a bucking operation using the voltage applied to the first power path 81 as an input voltage, and may perform a charging operation (voltage conversion operation) so as to apply the output voltage to the conductive path 83.

[0075] In the above-described embodiment, the discharging unit 30 has a configuration including the voltage conversion circuit 32, but it may have a configuration without the voltage conversion circuit 32. For example, the discharging unit 30 may be changed to a switching element.

[0076] It should be noted that the embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed this time, but is intended to include all modifications within the scope indicated by the claims or within the scope equivalent to the claims.

Explanation of Reference Numerals

[0077] 3: In-vehicle power supply system 10: Power supply unit 11: Load 12: First switch unit 13: Power storage unit 14: Cut-off unit 20: Charging unit 21: Second switch unit 22: Resistance unit 30: Discharging unit 31: Conductive path 32: Voltage conversion circuit 51: First voltage detection unit 52: Second voltage detection unit 53: Third voltage detection unit 60: In-vehicle control device 61: Control unit 80: Power path 81: First power path 82: Second power path 83: Conductive path 84: Conductive path 100: In-vehicle system

Claims

1. An in-vehicle control device used in an in-vehicle system including a power supply unit, a power storage unit different from the power supply unit, a power path that is a path for supplying power from the power supply unit to a load, a charging unit that performs a charging operation of supplying a current to the power storage unit based on the power supplied from the power supply unit, and a discharging unit that performs a discharging operation of flowing a current to the load side based on the power supplied from the power storage unit, the in-vehicle control device controlling the charging operation by the charging unit and the discharging operation by the discharging unit, having a control unit that controls the charging unit and the discharging unit, the control unit being capable of executing a first control for causing the charging unit to perform the charging operation and causing the discharging unit to perform the discharging operation, and a second control for causing the discharging unit to perform the discharging operation without causing the charging unit to perform the charging operation, and executing the first control when a voltage condition that the voltage of the power path is equal to or lower than a voltage failure determination voltage is satisfied and a failure determination condition different from the voltage condition is not satisfied, the failure determination condition including that the time during which the voltage of the power path is equal to or lower than the voltage failure determination voltage continues for a certain time, the control unit executing the second control when the time during which the voltage of the power path is equal to or lower than the voltage failure determination voltage continues for the certain time In-vehicle control device.

2. The in-vehicle system is provided with a switch unit in the power path, the charging unit supplying a current to the power storage unit based on the power supplied from a first power path on the power supply unit side of the switch unit in the power path, the discharging unit performing the discharging operation so as to flow a current through a second power path on the load side of the switch unit in the power path, when the switch unit is in an on state, energization between the first power path and the second power path is allowed in both directions, and when the switch unit is in an off state, at least energization from the second power path to the first power path is blocked, After satisfying the voltage condition, the control unit keeps the switch unit in the off state until a certain time has elapsed since the voltage of the power path has been equal to or lower than the defect determination voltage. After satisfying the voltage condition, the control unit turns on the switch unit on the condition that the voltage of the power path has exceeded the defect determination voltage before the certain time has elapsed since the voltage of the power path has been equal to or lower than the defect determination voltage. When the certain time has elapsed since the voltage of the power path has been equal to or lower than the defect determination voltage after satisfying the voltage condition, the control unit stops the charging operation while keeping the switch unit in the off state. The in-vehicle control device according to claim 1.

3. An in-vehicle control device used in an in-vehicle system including a power supply unit, a power storage unit different from the power supply unit, a power path that is a path for supplying power from the power supply unit to a load, a charging unit that performs a charging operation of supplying a current to the power storage unit based on the power supplied from the power supply unit, and a discharging unit that performs a discharging operation of flowing a current to the load side based on the power supplied from the power storage unit, the in-vehicle control device controlling the charging operation by the charging unit and the discharging operation by the discharging unit, having a control unit that controls the charging unit and the discharging unit, the control unit being capable of executing a first control for causing the charging unit to perform the charging operation and causing the discharging unit to perform the discharging operation, and a second control for causing the discharging unit to perform the discharging operation without causing the charging unit to perform the charging operation, and executing the first control when a voltage condition that the voltage of the power path is equal to or lower than a defect determination voltage is satisfied and a defect determination condition different from the voltage condition is not satisfied, the defect determination condition including that a current flows from the charging unit side to the power path side, the control unit executing the second control when a current flows from the charging unit side to the power path side. In-vehicle control device.

4. The in-vehicle system is provided with a switch unit in the power path, the charging unit supplying a current to the power storage unit based on the power supplied from a first power path on the power supply unit side of the switch unit in the power path, the discharging unit performing the discharging operation so as to flow a current through a second power path on the load side of the switch unit in the power path, when the switch unit is in the on state, energization between the first power path and the second power path is allowed bidirectionally, and when the switch unit is in the off state, at least energization from the second power path to the first power path is cut off. The control unit executes the first control on the condition that the voltage condition is satisfied and no current flows from the charging unit side to the power path side, and executes the second control while turning off the switch unit when the voltage condition is satisfied and current flows from the charging unit side to the power path side. The in-vehicle control device according to claim 3.

5. An in-vehicle control device used in an in-vehicle system including a power supply unit, a power storage unit different from the power supply unit, a power path that is a path for supplying power from the power supply unit to a load, a charging unit that performs a charging operation of supplying current to the power storage unit based on the power supplied from the power supply unit, and a discharging unit that performs a discharging operation of flowing current to the load side based on the power supplied from the power storage unit, the in-vehicle control device controlling the charging operation by the charging unit and the discharging operation by the discharging unit, having a control unit that controls the charging unit and the discharging unit, the control unit being capable of executing a first control for causing the charging unit to perform the charging operation and causing the discharging unit to perform the discharging operation, and a second control for causing the discharging unit to perform the discharging operation without causing the charging unit to perform the charging operation, and executing the first control when a voltage condition that the voltage of the power path is equal to or lower than a voltage drop determination voltage is satisfied and a voltage drop determination condition different from the voltage condition is not satisfied, the voltage drop determination condition including that the voltage of the power path has become equal to or lower than a reference voltage that is lower than the voltage drop determination voltage, the control unit executing the second control when the voltage becomes equal to or lower than the reference voltage In-vehicle control device.

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