In-vehicle control device

Abstract

A vehicle-mounted control device (10) comprises a control part (16), a voltage conversion part (30), a first element part (21), a second element part (22), and a third element part (23). The first element part (21) can permit the flow of current from the voltage conversion part (30) side to a second power route (82) side, and can shut off the flow of current from the second power route (82) side to the voltage conversion part (30) side. The second element part (22) can permit the flow of current from a first power route (82) side to the voltage conversion part (30) side, and can shut off the flow of current from the voltage conversion part (30) side to the first power route (81) side. The third element part (23) can permit the flow of current from a power storage part (92) side to the second power route (82) side, and can shut off the flow of current from the second power route (82) side to the power storage part (92) side.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a power supply system. The power supply system of Patent Document 1 includes a main battery and a sub-battery, and operates to switch the power supply source to the load from the main battery side to the sub-battery side when the power supply from the main battery side is interrupted. In the power supply system of Patent Document 1, a body diode is provided in the switch between the sub-battery and the load, and when the power from the main battery is interrupted, power is supplied to the load through the body diode even when the switch is in the off state, so the power supply is not interrupted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power supply system of Patent Document 1, there is a possibility that an appropriate voltage cannot be supplied to the load when the output voltage of the sub-battery decreases. In order to eliminate this concern, it is desirable to introduce a discharge circuit that can supply an appropriate voltage to the load based on the power from the sub-battery, but simply introducing it will complicate the device configuration. On the other hand, in a system that can supply power from the sub-battery to the load, when the sub-battery is discharged for some reason, it is necessary to recharge the sub-battery in case of failure, and for this purpose, it is desirable to introduce a charging circuit that can supply an appropriate voltage to the sub-battery, but simply introducing it will cause further complication.

[0005] The present disclosure relates to an in-vehicle control device capable of performing a backup operation that supplies power based on a power storage unit, and can adjust the charging voltage when charging the power storage unit and the discharging voltage when discharging the power storage unit with a simpler configuration, and one of the purposes is to provide a technology that can discharge the power storage unit through a path different from the path for adjusting the voltage.

Means for Solving the Problems

[0006] An in-vehicle control device which is one of the present disclosures is a power supply unit that supplies power, a power storage unit different from the power supply unit, a first power path to which a voltage based on the power supply unit is applied, a second power path that is a path for supplying the power supplied from the first power path to a load, a third power path different from the first power path and the second power path, and a fourth power path to which a voltage based on the power storage unit is applied, and is used in an in-vehicle system, and is an in-vehicle control device that controls power supply from the power storage unit, a voltage conversion unit that performs a first conversion operation of converting the voltage applied to the third power path and applying the output voltage to the fourth power path, and a second conversion operation of converting the voltage applied to the fourth power path and applying the output voltage to the third power path, a control unit that controls the voltage conversion unit, a first element unit that can allow current to flow from the voltage conversion unit side to the second power path side and can block current from flowing from the second power path side to the voltage conversion unit side, a second element unit that can allow current to flow from the first power path side to the voltage conversion unit side and can block current from flowing from the voltage conversion unit side to the first power path side, a third element unit that can allow current to flow from the power storage unit side to the second power path side and can block current from flowing from the second power path side to the power storage unit side, and includes.

Effects of the Invention

[0007] The technology according to the present disclosure can adjust the charging voltage when charging the power storage unit and the discharging voltage when discharging the power storage unit with a simpler configuration, and can discharge the power storage unit through a path different from the path for adjusting the voltage.

Brief Description of the Drawings

[0008]

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[0009] [Explanation of Embodiments of the Present Disclosure] Hereinafter, embodiments according to the present disclosure are listed and exemplified. Note that the features [1] to

[13] exemplified below may be combined in any combination without contradiction.

[0010] [1] An in-vehicle control device used in an in-vehicle system including a power supply unit that supplies power, a power storage unit different from the power supply unit, a first power path to which a voltage based on the power supply unit is applied, a second power path that is a path for supplying the power supplied from the first power path to a load, a third power path different from the first power path and the second power path, and a fourth power path to which a voltage based on the power storage unit is applied, and controlling power supply from the power storage unit, a voltage conversion unit that performs a first conversion operation of converting the voltage applied to the third power path and applying an output voltage to the fourth power path, and a second conversion operation of converting the voltage applied to the fourth power path and applying an output voltage to the third power path; a control unit that controls the voltage conversion unit; a first element unit that can allow current to flow from the voltage conversion unit side to the second power path side and can block current from flowing from the second power path side to the voltage conversion unit side; A second element section that allows current to flow from the first power path side to the voltage conversion section side and can block current from flowing from the voltage conversion section side to the first power path side; A third element section that allows current to flow from the power storage section side to the second power path side and can block current from flowing from the second power path side to the power storage section side; Comprising An in-vehicle control device.

[0011] In the in-vehicle control device according to [1] above, when the second element section allows current to flow from the first power path side to the voltage conversion section side, by causing the voltage conversion section to perform a first conversion operation, the power storage section can be charged while applying a desired voltage to the fourth power path. On the other hand, when the first element section allows current to flow from the voltage conversion section side to the second power path side, by causing the voltage conversion section to perform a second conversion operation, power can be supplied to the second power path while applying a desired voltage to the third power path. That is, this in-vehicle control device can adjust the charging voltage when charging the power storage section and the discharging voltage when discharging the power storage section with a simpler configuration. In some cases, the second element section can block current from flowing from the voltage conversion section side to the first power path side. Furthermore, since the third element section is provided and allows current to flow from the power storage section side to the second power path side, the power storage section can be discharged through a path different from the path for voltage adjustment by the voltage conversion section. Furthermore, since the third element section can block current from flowing from the second power path side to the power storage section side, in some cases, it is possible to block current from flowing into the power storage section from the second power path side through the third element section.

[0012] 〔2〕An in-vehicle control device according to [1], further comprising a fourth element section that allows current to flow from the first power path side to the second power path side and can block current from flowing from the second power path side to the first power path side. The in-vehicle control device according to [1].

[0013] In the in-vehicle control device of [2] above, since the fourth element unit allows current to flow from the first power path side to the second power path side, the power based on the power supply unit can be directly supplied to the second power path via the fourth element unit. On the other hand, in some cases, the fourth element unit can block current from flowing from the second power path side to the first power path side.

[0014] 〔3〕The fourth element unit is configured to bidirectionally block current from flowing between the first power path and the second power path through itself when it is in the off state, and allow current to flow from the first power path to the second power path through itself when it is in the on state. When the voltage of the first power path exceeds the first threshold value, the control unit sets the fourth element unit to the on state. When the voltage of the first power path is less than or equal to the first threshold value, while allowing current to flow from the power storage unit side to the second power path side in the third element unit, the control unit sets the fourth element unit to the off state. The in-vehicle control device according to [2].

[0015] In the in-vehicle control device of [3] above, when the voltage of the first power path exceeds the first threshold value, by setting the fourth element unit to the on state, the power based on the power supply unit can be directly supplied to the second power path while suppressing losses. On the other hand, when the voltage of the first power path is less than or equal to the first threshold value, since the control unit can set the fourth element unit to the off state while allowing current to flow from the power storage unit side to the second power path side in the third element unit, it is possible to suppress the influence of the first power path on the second power path via the fourth element unit and allow a discharge current to flow from the power storage unit to the second power path via the third element unit.

[0016] 〔4〕It includes an abnormality detection unit that detects an abnormality in the fourth element unit. The first element unit is configured to bidirectionally block current from flowing between the third power path and the second power path through itself when it is in the off state, and allow current to flow from the third power path to the second power path through itself when it is in the on state. When the abnormality detection unit detects an abnormality in the fourth element unit, while allowing current to flow from the first power path side to the third power path side in the second element unit, the control unit turns on the first element unit. The in-vehicle control device according to [2] or [3].

[0017] When the abnormality detection unit of the in-vehicle control device according to [4] above detects an abnormality in the fourth element unit, while allowing current to flow from the first power path side to the third power path side in the second element unit, the control unit can turn on the first element unit. Therefore, power can be supplied from the first power path side to the second power path side using the paths of the second element unit and the first element unit. On the other hand, the first element unit can also be turned off. In this case, it is possible to prevent current from flowing from the second power path side through the first element unit to the third power path side.

[0018] 〔5〕The fourth element unit is configured to bidirectionally block current flow between the first power path and the second power path through itself when it is in the off state, and allow current to flow from the first power path to the second power path through itself when it is in the on state. When the voltage of the first power path exceeds the first threshold value and is less than a voltage threshold value greater than the first threshold value, the control unit turns on the fourth element unit. When the voltage of the first power path is equal to or higher than the voltage threshold value, while allowing current to flow from the power storage unit side to the second power path side in the third element unit, the control unit turns off the fourth element unit. The in-vehicle control device according to any one of [2] to [4].

[0019] When the voltage of the first power path is not large enough to exceed the first threshold value until reaching the voltage threshold value, the in-vehicle control device described in [5] turns on the fourth element section, so that the power based on the power supply section can be directly supplied to the second power path while suppressing losses. On the other hand, when the voltage of the first power path rises too much to reach or exceed the voltage threshold value, since the fourth element section can be turned off while allowing current to flow from the storage section side to the second power path side in the third element section, it is possible to suppress the influence of the overvoltage of the first power path from reaching the second power path through the fourth element section and to allow a discharge current to flow from the storage section to the second power path through the third element section.

[0020] 〔6〕When the voltage of the first power path is equal to or higher than the voltage threshold value, while allowing current to flow from the storage section side to the second power path side in the third element section, the control section causes the voltage conversion section to perform the first conversion operation. The in-vehicle control device according to [5].

[0021] When the voltage of the first power path in the in-vehicle control device described in [6] rises too much to reach or exceed the voltage threshold value, while supplying power from the first power path to the storage section side, a discharge current can flow through the third element section to the second power path. Voltage conversion unit from the first power path to the storage section side while supplying power from the first power path to the storage section side, a discharge current can flow through the third element section to the second power path.

[0022] 〔7〕The second element section is configured to bidirectionally block current from flowing between the first power path and the third power path through itself when it is in the off state, and to allow current to flow from the first power path to the third power path through itself when it is in the on state. On the condition that the voltage of the first power path exceeds the first threshold value and is less than a voltage threshold value greater than the first threshold value, the control section sets the second element section to the on state. When the voltage of the first power path is equal to or higher than the voltage threshold value, while allowing current to flow from the third power path side to the second power path side in the first element section, the control section sets the second element section to the off state and causes the voltage conversion section to perform the second conversion operation. The in-vehicle control device according to any one of [1] to [3].

[0023] When the voltage of the first power path exceeds the first threshold value and is less than the voltage threshold value, the second element part is turned on, and power supply from the first power path side to the voltage conversion part side can be enabled. On the other hand, when the voltage of the first power path rises too much to be equal to or higher than the voltage threshold value, the second element part is turned off, the energization from the first power path side to the third power path side is cut off, and the voltage conversion part can be made to perform a second conversion operation in a state where the energization from the third power path side to the second power path side through the first element part is permitted.

[0024] 〔8〕When the voltage of the first power path is less than or equal to the first threshold value and a predetermined condition is satisfied, while allowing current to flow from the power storage part side to the second power path side in the third element part, the control part causes the voltage conversion part to perform the first conversion operation The in-vehicle control device according to any one of [1] to [7].

[0025] The in-vehicle control device according to [8] above can cause the voltage conversion part to perform the first conversion operation to supply power to the power storage part side even when the voltage of the first power path drops below the first threshold value and a predetermined condition is satisfied. While supplying power to the power storage part side in this way, it is also possible to supply power to the second power path side through the third element part.

[0026] 〔9〕The predetermined condition includes that a predetermined fault determination condition is not satisfied, When the voltage of the first power path is less than or equal to the first threshold value and the fault determination condition is not satisfied, while allowing current to flow from the first power path side to the voltage conversion part side in the second element part, the control part causes the voltage conversion part to perform the first conversion operation, When the voltage of the first power path is equal to or lower than the first threshold value and the open-circuit failure determination condition is satisfied, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking the current flowing from the voltage conversion unit side to the first power path side in the second element unit and allowing the current to flow from the third power path side to the second power path side in the first element unit. The in-vehicle control device according to [8].

[0027] The in-vehicle control device according to [9] allows current to flow to the voltage conversion unit side through the second element unit on the condition that the open-circuit failure determination condition is not satisfied even when the voltage of the first power path drops below the first threshold value, causes the voltage conversion unit to perform the first conversion operation, and can charge the power storage unit. On the other hand, when the open-circuit failure determination condition is satisfied, this in-vehicle control device can supply the voltage adjusted based on the voltage conversion operation of the voltage conversion unit to the second power path while blocking the reverse current to the first power path side.

[0028] 〔10〕The third element unit is configured to bidirectionally block the current flowing between the fourth power path and the second power path through itself when it is in the off state, and allow the current to flow from the fourth power path to the second power path through itself when it is in the on state. The control unit controls at least the on / off of the third element unit. When the voltage of the first power path is equal to or lower than the first threshold value and a transition occurs from a state where the open-circuit failure determination condition is not satisfied to a state where it is satisfied, the control unit maintains the third element unit in the on state before and after the transition. After the transition, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking the current flowing from the voltage conversion unit side to the first power path side in the second element unit and allowing the current to flow from the third power path side to the second power path side in the first element unit. When the voltage conversion unit satisfies a predetermined operating condition after the transition, the control unit switches the third element unit to the off state. The in-vehicle control device according to [9].

[0029] When the voltage of the first power path becomes less than or equal to the first threshold value and the open-circuit failure determination condition changes to a state where it is not satisfied, the in-vehicle control device of

[10] can quickly supply power from the power storage unit to the second power path by turning on the third element unit. Then, when a switch occurs from a state where the open-circuit failure determination condition is not satisfied to a state where it is satisfied while the voltage of the first power path is less than or equal to the first threshold value, after the switch, while preventing backflow to the first power path side, the power whose voltage has been adjusted by the second conversion operation can be supplied to the second power path via the third power path and the first element unit. Moreover, since this in-vehicle control device can maintain the third element unit in the on state before and after the switch, even if the rise of the output of the voltage conversion unit is slow after the switch, the power supply from the power storage unit to the second power path via the third element unit can be continued. Further, when the voltage conversion unit satisfies a predetermined operation condition after the switch, this in-vehicle control device can narrow down the discharge path to the path of the first element unit among the first element unit and the third element unit by switching the third element unit to the off state.

[0030] 〔11〕The open-circuit failure determination condition includes a condition that a current flows from the voltage conversion unit side to the first power path side via the second element unit. On the condition that no current flows from the voltage conversion unit side to the first power path side via the second element unit when the voltage of the first power path is less than or equal to the first threshold value, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, and allows a current to flow from the power storage unit side to the second power path side in the third element unit. When a current flows from the voltage conversion unit side to the first power path side via the second element unit when the voltage of the first power path is less than or equal to the first threshold value, the flow of the current from the voltage conversion unit side to the first power path side in the second element unit is blocked, and the control unit causes the voltage conversion unit to perform the second conversion operation while allowing a current to flow from the third power path side to the second power path side in the first element unit. The in-vehicle control device according to [9] or

[10] .

[0031] When the voltage of the first power path is equal to or lower than the first threshold value, the in-vehicle control device according to

[11] can confirm that no current flows to the first power path side through the second element unit, that is, it is highly likely that no ground fault has occurred in the first power path, and then cause the voltage conversion unit to perform the first conversion operation to charge the power storage unit. And this in-vehicle control device can perform discharge through the third element unit in parallel with the power supply to the power storage unit side by the first conversion operation. On the other hand, when the voltage of the first power path is equal to or lower than the first threshold value and current flows to the first power path side through the second element unit, that is, when there may be a ground fault in the first power path, the second element unit can block the current from flowing to the first power path side, and suppress the influence of the ground fault from reaching the third power path side. And by allowing the voltage conversion unit to perform the second conversion operation while allowing current to flow to the second power path side in the first element unit, it is possible to supply the power whose voltage is adjusted by the voltage conversion unit to the second power path while suppressing the influence of the ground fault.

[0032] 〔12〕The ground fault determination condition includes the condition that the voltage of the first power path becomes equal to or lower than a second threshold value that is lower than the first threshold value. On the condition that the voltage of the first power path is equal to or lower than the first threshold value and exceeds the second threshold value, the control unit allows current to flow from the first power path side to the voltage conversion unit side in the second element unit and causes the voltage conversion unit to perform the first conversion operation, and allows current to flow from the power storage unit side to the second power path side in the third element unit. When the voltage of the first power path is equal to or lower than the second threshold value, the second element unit blocks the current from flowing from the voltage conversion unit side to the first power path side, and the control unit allows current to flow from the third power path side to the second power path side in the first element unit and causes the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to any one of [9] to

[11] .

[0033] When the voltage of the first power path is equal to or lower than the first threshold value, after confirming that the voltage exceeds the second threshold value, that is, the voltage of the first power path is not too low, the in-vehicle control device causes the voltage conversion unit to perform the first conversion operation, and can charge the power storage unit. Then, this in-vehicle control device can perform discharge through the third element unit in parallel with the power supply to the power storage unit side by the first conversion operation. On the other hand, when the voltage of the first power path is equal to or lower than the second threshold value, that is, when the voltage of the first power path is too low, since the second element unit can block the current from flowing to the first power path side, even if a ground fault occurs in the first power path, the influence of the ground fault on the third power path side can be suppressed. And, by allowing the current to flow to the second power path side in the first element unit while causing the voltage conversion unit to perform the second conversion operation, while suppressing the influence of the voltage drop in the first power path, the power whose voltage has been adjusted by the voltage conversion unit can be supplied to the second power path.

[0034] 〔1 3 〕The fault determination condition includes a condition in which a predetermined fault signal is given to the in-vehicle control device from an external device different from the in-vehicle control device. On the condition that the voltage of the first power path is equal to or lower than the first threshold value and the fault signal is not given from the external device, while allowing the current to flow from the first power path side to the voltage conversion unit side in the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation, and allows the current to flow from the power storage unit side to the second power path side in the third element unit. When the voltage of the first power path is equal to or lower than the first threshold value and the fault signal is given from the external device, the second element unit blocks the current from flowing from the voltage conversion unit side to the first power path side, and while allowing the current to flow from the third power path side to the second power path side in the first element unit, the control unit causes the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to any one of 〔9〕 to 〔12〕.

[0035] When the voltage of the first power path is less than or equal to the first threshold value, the in-vehicle control device described in

[13] can cause the voltage conversion unit to perform a first conversion operation and charge the power storage unit after confirming that no fault signal is received from an external device. Then, this in-vehicle control device can perform discharge via the third element unit in parallel with the power supply to the power storage unit side by the first conversion operation. On the other hand, when a fault signal occurs while the voltage of the first power path is less than or equal to the first threshold value, the second element unit can be made to perform a second conversion operation on the voltage conversion unit while blocking the current flowing to the first power path side and allowing the current to flow to the second power path side in the first element unit. Therefore, even if a ground fault or the like occurs in the first power path when a fault signal occurs, it is possible to supply the power whose voltage is adjusted by the voltage conversion unit to the second power path while suppressing the influence.

[0036] 〔14〕During the period in which the control unit causes the voltage conversion unit to perform the first conversion operation while allowing current to flow from the power storage unit side to the second power path side in the third element unit, the control unit makes the power supplied from the voltage conversion unit to the fourth power path side larger than the power supplied to the second power path side via the third element unit. 〔8〕The in-vehicle control device according to any one of [8] to

[13] .

[0037] When performing the first conversion operation and the discharge via the third element unit in parallel, the in-vehicle control device described in

[14] can make the charging power based on the first conversion operation larger than the discharge power via the third element unit. Therefore, when the above parallel operation is performed, it is possible to supply power to the second conductive path while more reliably securing the charging current to the power storage unit.

[0038] 〔15〕When the voltage of the first power path exceeds the first threshold value and the output voltage of the power storage unit is less than or equal to a predetermined value, the control unit allows the current to flow from the first power path side to the voltage conversion unit side in the second element unit and causes the voltage conversion unit to perform the first conversion operation. 〔1〕The in-vehicle control device according to any one of [1] to

[14] .

[0039] When the output voltage of the power storage unit drops below a predetermined value, the in-vehicle control device of

[15] above can charge the power storage unit by the first conversion operation. [Details of Embodiments of the Present Disclosure]

[0040] <First Embodiment> 1. Overview of In-Vehicle System FIG. 1 shows an in-vehicle system 2. The in-vehicle system 2 in FIG. 1 mainly includes an in-vehicle power supply system 3 and a load 101. 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 2 is a system that supplies power to the load 101 by the power supply system 3 and operates the load 101. In FIG. 1, the load 101 is illustrated as an example of an in-vehicle load, but other loads may be provided in the in-vehicle system 2.

[0041] The load 101 is an electrical component mounted on the vehicle. The load 101 operates by receiving power supplied via the power path 80. The type of the load 101 is not limited. Various known in-vehicle components can be adopted as the load 101. The load 101 may have a plurality of electrical components or may be a single electrical component.

[0042] The power supply system 3 is a system that supplies power to the load 101. The power supply system 3 supplies power to the load 101 using the power supply unit 91 or the power storage unit 92 as a power supply source. The power supply system 3 can supply power from the power supply unit 91 to the load 101. For example, when the power supply from the power supply unit 91 is interrupted due to a failure or the like, the power supply system 3 can supply power from the power storage unit 92 to the load 101. The power storage unit 92 may be used as a supply source that supplies power to the load 101 even when the power supply from the power supply unit 91 to the load 101 is not interrupted depending on the situation.

[0043] 2. Overview of Power Supply System The power supply system 3 includes a power supply unit 91, a power storage unit 92, an in-vehicle control device 10, etc. In the representative example shown in FIG. 1, a first power path 81, a second power path 82, a third power path 83, a fourth power path 84, a conductive path 89, etc. are configured as part of the in-vehicle control device 10. However, any of the first power path 81, the second power path 82, the third power path 83, the fourth power path 84, and the conductive path 89 may not be an element of the in-vehicle control device 10, either partially or entirely.

[0044] The power supply unit 91 is an in-vehicle power supply capable of supplying power to the load 101. The power supply unit 91 is configured as a known in-vehicle power storage unit such as a lead battery, for example. The power supply unit 91 may be configured by a battery other than a lead battery (for example, a lithium-ion battery or other batteries, etc.), and may have power supply means other than a battery instead of or in addition to a battery. In the example of FIG. 1, the positive electrode of the power supply unit 91 is electrically connected to the first power path 81 in a configuration short-circuited to a part of the power path 80, which is the first power path 81. The negative electrode of the power supply unit 91 is electrically connected to the ground in a configuration short-circuited to the ground. The power supply unit 91 applies a DC voltage of a certain value to the first power path 81. The voltage applied by the power supply unit 91 to the first power path 81 may vary slightly from the above-mentioned certain value.

[0045] The power storage unit 92 is a power source different from the power supply unit 91. The power storage unit 92 is a power source that serves as a power supply source at least when the power supply from the power supply unit 91 is interrupted. The power storage unit 92 is configured by known power storage means such as an electric double layer capacitor (EDLC), for example. The power storage unit 92 may be configured by a capacitor other than an electric double layer capacitor, and may be provided with other power storage means (such as a battery) instead of or in addition to a capacitor. In the example of FIG. 1, the positive electrode of the power storage unit 92 is electrically connected to the fourth power path 84 in a configuration short-circuited to the fourth power path 84. The negative electrode of the power storage unit 92 is electrically connected to the ground in a configuration short-circuited to the ground. The output voltage of the power storage unit 92 (the voltage applied to the fourth power path 84 by the power storage unit 92) may be greater than, less than, or approximately the same as the output voltage of the power supply unit 91 (the voltage applied to the first power path 81 by the power supply unit 91).

[0046] In this specification, unless otherwise specified, the voltage is the voltage with respect to the ground potential (e.g., 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 fourth power path 84 is the potential difference between the potential of the fourth power path 84 and the ground potential.

[0047] The power path 80 is a path through which the power based on the power supply unit 91 is transmitted, and is a path for supplying the power based on the power supply unit 91 to the load 101. In the example of FIG. 1, the power path 80 includes a first power path 81 to which the voltage based on the power supply unit 91 is applied, and a second power path 82 which is a path for supplying the power supplied from the first power path 81 to the load 101.

[0048] The first power path 81 is a conductive path that constitutes part or all of the power supply path between the power supply unit 91 and the second element unit 22. A voltage identical or substantially identical to the output voltage of the power supply unit 91 is applied to the first power path 81. A part of one end side 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 91. In the example of FIG. 1, a part of the other end side of the first power path 81 is electrically connected to one end portion of the second element unit 22 (in the example of FIG. 1, the drain terminal which is one end of the semiconductor switch) in a configuration short-circuited to the one end portion. Further, a part of the first power path 81 is electrically connected to one end portion of the fourth element unit 24 (in the example of FIG. 1, the drain terminal which is one end of the semiconductor switch 24A) in a configuration short-circuited to the one end portion. A relay or a fuse may be provided in the first power path 81. The first power path 81 functions to make the positive electrode of the power supply unit 91, one end portion of the second element unit 22, and one end portion of the fourth element unit 24 at the same potential or substantially the same potential.

[0049] The second power path 82 is a conductive path that constitutes part or all of the power supply path between the first element unit 21 and the load 101. A part of one end side of the second power path 82 is electrically connected to the other end of the first element unit 21 (in the example of FIG. 1, the drain terminal which is the other end of the semiconductor switch 21B). Further, a part of the second power path 82 is electrically connected in a configuration short-circuited to the other end of the fourth element unit 24 (in the example of FIG. 1, the drain terminal which is one end of the semiconductor switch 24B), and is electrically connected in a configuration short-circuited to the other end of the third element unit 23 (in the example of FIG. 1, the drain terminal which is one end of the semiconductor switch 23B). In the example of FIG. 1, a part of the other end side of the second power path 82 is electrically connected to the load 101 in a configuration short-circuited to one end of the load 101. A relay or a fuse may be provided in the second power path 82. The second power path 82 functions, for example, to make the other end of the first element unit 21, the other end of the fourth element unit 24, the other end of the third element unit 23, and one end of the load 101 at the same potential or substantially the same potential.

[0050] The third power path 83 is a power path different from the first power path 81 and the second power path 82. A part of one end side of the third power path 83 is electrically connected to the other end of the second element unit 22 (in the example of FIG. 1, the source terminal which is the other end of the semiconductor switch) in a configuration short-circuited to the other end. A part of the other end side of the third power path 83 is electrically connected to one end of the voltage conversion unit 30 in a configuration short-circuited to the one end. A part of the third power path 83 is electrically connected in a configuration short-circuited to one end of the first element unit 21 (in the example of FIG. 1, the drain terminal which is one end of the semiconductor switch 21A). The third power path 83 functions, for example, to make one end of the first element unit 21, the other end of the second element unit 22, and one end of the voltage conversion unit 30 at the same potential or substantially the same potential.

[0051] The fourth power path 84 is a power path different from the first power path 81, the second power path 82, and the third power path 83, and is a power path to which a voltage based on the power storage unit 92 is applied. A part of one end side of the fourth power path 84 is electrically connected to the other end of the voltage conversion unit 30 in a configuration short-circuited to the other end. A part of the other end side of the fourth power path 84 is electrically connected in a configuration short-circuited to the positive electrode of the power storage unit 92. A part of the fourth power path 84 is electrically connected to one end of the third element unit 23 (in the example of FIG. 1, the drain terminal which is one end of the semiconductor switch 23A) in a configuration short-circuited to the one end. The fourth power path 84 functions, for example, to make the other end of the voltage conversion unit 30, the positive electrode of the power storage unit 92, and one end of the third element unit 23 have the same potential or substantially the same potential.

[0052] 3. Details of the in-vehicle control device The in-vehicle control device 10 is used in the in-vehicle system 2 and is a device that controls power supply from the power storage unit 92. The in-vehicle control device 10 is a backup control device that can control a backup operation of outputting power based on the power storage unit 92. The in-vehicle control device 10 includes the first power path 81, the second power path 82, the third power path 83, the fourth power path 84, the control unit 16, the voltage conversion unit 30, the first element unit 21, the second element unit 22, the third element unit 23, the fourth element unit 24, the voltage detection units 41, 43, 44, etc.

[0053] In a representative example, the in-vehicle control device 10 includes the first power path 81, the second power path 82, the third power path 83, and the fourth power path 84, but may include only a part of each, and any one or all of the power paths may not be elements of the in-vehicle control device 10.

[0054] In the representative example of FIG. 1, the first element section 21 is composed of two semiconductor switches 21A and 21B. The second element section 22 is composed of one semiconductor switch. The third element section 23 is composed of two semiconductor switches 23A and 23B. The fourth element section 24 is composed of two semiconductor switches 24A and 24B. In the example of FIG. 1, the semiconductor switches 21A, 21B, 22, 23A, 23B, 24A, and 24B are all composed of N-channel FETs (Field Effect Transistors).

[0055] The first element section 21 is a switch section that can allow current to flow from the voltage conversion section 30 side to the second power path 82 side and can block current from flowing from the second power path 82 side to the voltage conversion section 30 side. The semiconductor switches 21A and 21B that constitute the first element section 21 are connected in opposite directions to each other. In the example of FIG. 1, the drain of the semiconductor switch 21A is short-circuited to the third power path 83, the drain of the semiconductor switch 21B is short-circuited to the second power path 82, and the sources of the semiconductor switch 21A and the semiconductor switch 21B are short-circuited. The off state of the first element section 21 means that both the semiconductor switches 21A and 21B are in the off state. When the first element section 21 is in the off state, energization through the first element section 21 is blocked in both directions, and both the flow of current from the second power path 82 side to the voltage conversion section 30 side and the flow of current from the voltage conversion section 30 side to the second power path 82 side are blocked. The on state of the first element section 21 means that both the semiconductor switches 21A and 21B are in the on state. When the first element section 21 is in the on state, energization through the first element section 21 is allowed in both directions, and both the flow of current from the second power path 82 side to the voltage conversion section 30 side and the flow of current from the voltage conversion section 30 side to the second power path 82 side are allowed.

[0056] The second element section 22 is configured to allow current to flow from the first power path 81 side to the voltage conversion section 30 side, and to block current from flowing from the voltage conversion section 30 side to the first power path 81 side. In the example of FIG. 1, the drain of the second element section 22 is electrically connected so as to be short-circuited to the third power path 83, and the source of the second element section 22 is electrically connected so as to be short-circuited to the first power path 81. When the second element section 22 is in the on state, energization through the second element section 22 is allowed in both directions. When the second element section 22 is in the off state, current flow from the voltage conversion section 30 side to the first power path 81 side through the second element section 22 is always blocked.

[0057] The third element section 23 is a switch section that allows current to flow from the power storage section 92 side to the second power path 82 side and blocks current from flowing from the second power path 82 side to the power storage section 92 side. The semiconductor switches 23A and 23B that constitute the third element section 23 are connected in opposite directions to each other. In the example of FIG. 1, the drain of the semiconductor switch 23A is short-circuited to the fourth power path 84, the drain of the semiconductor switch 23B is short-circuited to the second power path 82, and the sources of the semiconductor switches 24A and 24B are short-circuited. The off state of the third element section 23 means that both the semiconductor switches 23A and 23B are in the off state. When the third element section 23 is in the off state, energization through the third element section 23 is blocked in both directions, and current flow from the second power path 82 side to the power storage section 92 side through the third element section 23 and current flow from the power storage section 92 side to the second power path 82 side through the third element section 23 are both blocked. The on state of the third element section 23 means that both the semiconductor switches 23A and 23B are in the on state. When the third element section 23 is in the on state, energization through the third element section 23 is allowed in both directions, and current flow from the second power path 82 side to the power storage section 92 side and From the power storage unit 92 side to the second power path 82 side current flow in are both allowed.

[0058] The fourth element section 24 is a switch section that allows current to flow from the first power path 81 side to the second power path 82 side and can block current from flowing from the second power path 82 side to the first power path 81 side. The semiconductor switches 24A and 24B that make up the fourth element section 24 are connected in opposite directions to each other. In the example of FIG. 1, the drain of the semiconductor switch 24A is short-circuited to the first power path 81, the drain of the semiconductor switch 24B is short-circuited to the second power path 82, and the source of the semiconductor switch 24A and the source of the semiconductor switch 24B are short-circuited. The off state of the fourth element section 24 means that both the semiconductor switches 24A and 24B are in the off state. When the fourth element section 24 is in the off state, energization through the fourth element section 24 is blocked in both directions, and both the flow of current from the first power path 81 side through the fourth element section 24 to the second power path 82 side and the flow of current from the second power path 82 side through the fourth element section 24 to the first power path 81 side are blocked. The on state of the fourth element section 24 means that both the semiconductor switches 24A and 24B are in the on state. When the fourth element section 24 is in the on state, energization through the fourth element section 24 is allowed in both directions, and both the flow of current from the first power path 81 side to the second power path 82 side and the flow of current from the second power path 82 side to the first power path 81 side are allowed.

[0059] The voltage conversion section 30 is constituted by a known voltage conversion circuit such as a DC-DC converter, for example. In the example of FIG. 1, the voltage conversion section 30 performs voltage conversion between the third power path 83 and the fourth power path 84. The voltage conversion section 30 is a device that performs a first conversion operation of voltage-converting the voltage applied to the third power path 83 to step up or step down the voltage and applying the output voltage to the fourth power path 84, and a second conversion operation of voltage-converting the voltage applied to the fourth power path 84 to step up or step down the voltage and applying the output voltage to the third power path 83. Thus, the voltage conversion section 30 performs voltage conversion in both directions. The operation of the voltage conversion section 30 is controlled by the control section 16.

[0060] The control unit 16 is a device that controls the voltage conversion unit 30, the first element unit 21, the second element unit 22, the third element unit 23, the fourth element unit 24, etc. The control unit 16 has an information processing device having an information processing function, an arithmetic function, a control function, etc., and may be constituted by this information processing device, or may be constituted by an information processing device and other devices. For example, the control unit 16 may be such that a common control device controls all of the voltage conversion unit 30, the first element unit 21, the second element unit 22, the third element unit 23, and the fourth element unit 24, or a device that controls some of them and a device that controls the other part may be separate.

[0061] The voltage detection unit 41 is a circuit that gives the control unit 16 a detection value (for example, an analog voltage value) that can identify the value of the voltage applied to the first power path 81. The voltage detection unit 43 is a circuit that gives the control unit 16 a detection value (for example, an analog voltage value) that can identify the value of the voltage applied to the third power path 83. The voltage detection unit 44 is a circuit that gives the control unit 16 a detection value (for example, an analog voltage value) that can identify the value of the voltage applied to the fourth power path 84.

[0062] 4. Operation of the in-vehicle control device The following description relates to the control for backup operation performed by the in-vehicle control device 10. FIG. 2 is a flowchart illustrating the flow of control for backup operation.

[0063] When a predetermined start condition is satisfied, the control unit 16 starts the control for backup operation shown in FIG. 2. The above "start condition" may be, for example, the condition that "the vehicle is in a starting state", or may be that a predetermined instruction is given from an external device (for example, an external ECU), or may be other conditions. In the representative example described below, the control unit 16 determines that the start condition is satisfied when the vehicle equipped with the in-vehicle system 2 is in a starting state, and starts the control for backup operation shown in FIG. 2. The case where the vehicle is in a starting state means, for example, the case where a start switch such as an ignition switch in a hybrid vehicle or a power switch in an electric vehicle is switched from the off state to the on state.

[0064] Note that when the control unit 16 starts the control shown in FIG. 2, it may continue the control shown in FIG. 2 until a predetermined end condition is satisfied, and end the control shown in FIG. 2 when the predetermined end condition is satisfied. The predetermined end condition may be, for example, that the start switch of the vehicle has been switched from the on state to the off state, or other conditions.

[0065] When the control unit 16 starts the control for backup operation shown in FIG. 2, it determines whether 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 an example of the first threshold. When the control unit 16 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, it determines in step S2 whether the voltage of the first power path 81 is equal to or higher than the overvoltage threshold Vth3. The overvoltage threshold Vth3 corresponds to an example of the voltage threshold. When the control unit 16 determines in step S2 that the voltage of the first power path 81 is not equal to or higher than the overvoltage threshold Vth3, in step S3, it turns off the first element unit 21, turns on the second element unit 22, turns off the third element unit 23, and turns on the fourth element unit 24.

[0066] Thus, when the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (the first threshold) and is less than the overvoltage threshold Vth3 (the voltage threshold) greater than the low voltage threshold Vth1, the control unit 16 turns on the fourth element unit 24.

[0067] After step S3, the control unit 16 determines whether the fourth element unit 24 is abnormal in step S4. For example, the control unit 16 may determine that the fourth element unit 24 is abnormal when the voltage of the second power path 82 immediately after step S3 is equal to or lower than a predetermined reference value. Alternatively, the control unit 16 may determine that the fourth element unit 24 is abnormal when the voltage applied to the gate of the fourth element unit 24 is an off voltage while the fourth element unit 24 is being turned on. Alternatively, the control unit 16 may determine that the fourth element unit 24 is abnormal when there is a temperature abnormality such that the temperature near the fourth element unit 24 exceeds a threshold temperature. In the present embodiment, the control unit 16 corresponds to an example of an abnormality detection unit and has a function of detecting an abnormality of the fourth element unit 24.

[0068] When the control unit 16 determines in step S4 that the fourth element unit 24 is not abnormal, it determines in step S5 whether charging conditions are satisfied. In a representative example, the case where the voltage of the fourth power path 84 is equal to or lower than a predetermined value in a state where at least the voltage conversion unit 30 has stopped the charging operation (a state where the first conversion operation is not being performed) is the case where the charging conditions are satisfied. The control unit 16 determines in step S 5 whether the above charging conditions are satisfied. If it is determined that the charging conditions are satisfied, the process proceeds to step S6. If it is determined that the charging conditions are not satisfied, the process proceeds to step S7. In the representative example, the case where the voltage of the fourth power path 84 is equal to or higher than a full charge voltage that is higher than a predetermined value (lower limit voltage) is the case where the charging conditions are not satisfied, and the case where the voltage of the fourth power path is equal to or higher than the above predetermined value during the stop of the first conversion operation is the case where the charging conditions are not satisfied. On the other hand, the case where the voltage of the fourth power path does not reach the full charge voltage or higher during the first conversion operation is the case where the charging conditions are satisfied.

[0069] When the control unit 16 advances the process to step S6, it causes the voltage conversion unit 30 to perform a first conversion operation in step S6. The first conversion operation is a step-down operation or a step-up operation for applying an output voltage of a first target value to the fourth power path 84. The first target value is, for example, larger than the above-described predetermined value. When the process of step S6 is performed, power is supplied in the flow as shown in FIG. 3. When the control unit 16 advances the process to step S7, it sets the voltage conversion unit 30 in a stopped state in step S7. FIG. 4 is an explanatory diagram showing each change in a normal state where the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and is less than the overvoltage threshold Vth3 (voltage threshold) larger than the low voltage threshold Vth1. In the example of FIG. 4, the above-described start condition is satisfied at time t11, and the control of FIG. 2 is started. In this example, after the start condition is satisfied at time t11, the first conversion operation (charging operation) is performed during periods t11 to 12 and t13 to t14 that satisfy the above charging condition, and the first conversion operation (charging operation) is performed during periods t12 to 13 and t14 to that do not satisfy the above charging condition None 。

[0070] As described above, in the present embodiment, when the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and the output voltage of the power storage unit 92 is equal to or lower than a predetermined value, the control unit 16 causes the voltage conversion unit 30 to perform a first conversion operation while allowing a current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22.

[0071] When the control unit 16 determines in step S4 that the fourth element unit 24 is abnormal, in step S8, it turns on the first element unit 21, turns on the second element unit 22, turns off the third element unit 23, and turns on the fourth element unit 24. After step S8, the control unit 16 notifies an external device (for example, an external ECU) in step S9 that the fourth element unit 24 is abnormal. Thus, in the present embodiment, when the abnormality detection unit detects an abnormality in the fourth element unit 24, while allowing current to flow from the first power path 81 side to the third power path 83 side in the second element unit 22, the control unit 16 turns on the first element unit 21. When the control unit 16 performs an operation as in step S4, as shown in FIG. 10, the fourth element unit 24 can be turned off, and power can be supplied to the second power path via the second element unit 22 and the first element unit 21. When performing an operation as in FIG. 10, the voltage conversion unit 30 may always be stopped, or control may be performed such that the first conversion operation is performed when the voltage of the fourth power path 84 drops below the predetermined value. FIG. 11 is an example when an abnormality in the fourth element unit 24 is confirmed. In the example of FIG. 11, the state before time t 41 is the above-described normal state, and an abnormality in the fourth element unit 24 is confirmed at time t41. In this example, the first element unit 21 is turned off until time t41, and the current flowing through the second power path 82 via the first element unit 21 is ensured by turning on the first element unit 21 after time t41. In the representative example shown in FIG. 11 and the like, the fourth element unit 24 is kept on even after an abnormality is detected in the fourth element unit 24, but the fourth element unit 24 may be switched to the off state when an abnormality in the fourth element unit 24 is detected.

[0072] When the control unit 16 determines in step S2 that the voltage of the first power path 81 is equal to or higher than the overvoltage threshold value (voltage threshold value), in step S10, it turns off the first element unit 21, turns on the second element unit 22, turns on the third element unit 23, and turns off the fourth element unit 24. After step S10, the control unit 16 performs the first conversion operation in step S11. Thus, in the present embodiment, the The voltage isWhen it is equal to or higher than the above overvoltage threshold (voltage threshold), while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23, the control unit 16 can cause the voltage conversion unit to perform the first conversion operation. When the control unit 16 performs operations such as in steps S10 and S11, as shown in FIG. 12, the fourth element unit 24 and the first element unit 21 are turned off, and while performing the first conversion operation, power based on the power storage unit 92 can be supplied to the second power path 82 via the third element unit 23. After step S11, the control unit 16 determines whether the voltage of the first power path 81 has become less than the overvoltage threshold. If it is determined that the voltage of the first power path 81 is equal to or higher than the overvoltage threshold, the process proceeds to No in step S12, and the first conversion operation is continued. When the control unit 16 determines in step S12 that the voltage of the first power path 81 is less than the overvoltage threshold, the process proceeds to Yes in step S12, the process proceeds to step S3, and the process can proceed as a normal state thereafter.

[0073] FIG. 13 shows an example where an overvoltage state occurs in the first power path 81. In the example of FIG. 13, the state before time 51 is the above-described normal state, the voltage of the first power path 81 becomes equal to or higher than the above overvoltage threshold (voltage threshold) at time t51, and it is determined that the voltage of the first power path 81 has become less than the above overvoltage threshold (voltage threshold) at time t52. In such an example, between time t51 and time t52, while performing the first conversion operation and supplying power via the third element unit 23, the current supply via the fourth element unit 24 is stopped. On the other hand, after time t52, the operation returns to the normal operation, and current can be supplied via the fourth element unit 24. Thus, in this configuration, when the voltage of the first power path 81 is equal to or higher than the overvoltage threshold Vth3 (voltage threshold), while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23, the control unit 16 turns off the fourth element unit 24

[0074] When the control unit 16 determines in step S1 that the voltage of the first power path 81 is less than or equal to the low voltage threshold value (first threshold value), in step S13, the control unit 16 turns off the first element unit 21, turns on the second element unit 22, turns on the third element unit 23, and turns off the fourth element unit 24. After step S13, the control unit 16 determines in step S14 whether or not the breakdown condition is satisfied. If the breakdown condition is not satisfied, the control unit 16 performs the first conversion operation in step S15. When the control unit 16 performs an operation as in step S15, as shown in FIG. 5, the fourth element unit 24 and the first element unit 21 are turned off, and while performing the first conversion operation, the power based on the power storage unit 92 can be supplied to the second power path 82 through the third element unit 23. The example of FIG. 6 is an example in the case where the voltage of the first power path 81 becomes less than or equal to the low voltage threshold value (first threshold value) and the breakdown determination condition is not satisfied. In the example of FIG. 6, after the voltage of the first power path 81 becomes less than or equal to the low voltage threshold value (first threshold value) at time t21, the breakdown determination condition is not satisfied, and the voltage of the first power path 81 returns to exceed the low voltage threshold value (first threshold value) at time t22. In this example, from time t21 to time t22, it can operate as shown in FIG. 5, and after time t22, it can operate in the same manner as the above-described normal state.

[0075] When the control unit 16 determines in step S14 that the breakdown condition is satisfied, in step S16, it turns off the first element unit 21, turns off the second element unit 22, turns on the third element unit 23, and turns off the fourth element unit 24. After step S16, the control unit 16 performs a second conversion operation in step S17. After step S17, the control unit 16 determines whether the stop condition is satisfied in step S18. If it is satisfied, the control unit 16 continues the second conversion operation while continuing the operations of the respective element units performed in step S16. When the control unit 16 determines in step S18 that the stop condition is satisfied, in step S19, it turns on the first element unit 21, turns off the second element unit 22, turns off the third element unit 23, and turns off the fourth element unit 24. When proceeding to Yes in step S18, power supply is performed as shown in FIG. 7, and when the process of step S19 is performed, power supply is performed as shown in FIG. 8. The above stop condition may be that the voltage of the third power path 83 exceeds a certain value, or a certain time has elapsed since the start of the second conversion operation in step S17, or other conditions may also be possible.

[0076] FIG. 9 illustrates an example when it is determined as Yes in step S14. In the example of FIG. 9, the low voltage threshold Vt1 is reached at time t31, and after time t31, it is determined as Yes in step S1 in the control of FIG. 2. The period from time t31 to time t32 is a period during which the breakdown determination condition is not satisfied. During this period, a No determination is made in step S14, and the process of step S15 is continuously performed. The period from time t32 to time t33 is a period during which the stop condition is not satisfied when the breakdown determination condition is satisfied, and after time t33 is a period during which the stop condition is satisfied when the breakdown determination condition is satisfied.

[0077] As described above, in this configuration, when the voltage of the first power path 81 is equal to or lower than the first threshold value, while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23, the control unit 16 turns off the fourth element unit 24. Then, when a predetermined condition is satisfied when the voltage of the first power path 81 is equal to or lower than the first threshold value, as shown in FIG. 5, while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23, the control unit 16 causes the voltage conversion unit 30 to perform a first conversion operation.

[0078] In this specification, the above-described predetermined condition includes, on the condition that a predetermined defect determination condition is not satisfied. That is, on the condition that the defect determination condition is not satisfied when the voltage of the first power path 81 is equal to or lower than the first threshold value, while allowing current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, the control unit 16 operates to cause the voltage conversion unit 30 to perform a first conversion operation. On the other hand, when the defect determination condition is satisfied when the voltage of the first power path 81 is equal to or lower than the first threshold value, the control unit 16 causes the voltage conversion unit 30 to perform a second conversion operation while blocking current from flowing from the voltage conversion unit 30 side to the first power path 81 side in the second element unit 22 and allowing current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21.

[0079] When the voltage of the first power path 81 is equal to or lower than the first threshold value, and when a switch occurs from a state where the defect determination condition is not satisfied to a state where the defect determination condition is satisfied, the control unit 16 maintains the third element unit 23 in the on state before and after the switch. After the switch, the control unit 16 blocks current from flowing from the voltage conversion unit 30 side to the first power path 81 side in the second element unit 22 and allows current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21, and causes the voltage conversion unit 30 to perform a second conversion operation. When the voltage conversion unit 30 satisfies a predetermined operating condition after the switch, the control unit 16 can operate to switch the third element unit 23 to the off state.

[0080] In the representative example, the above-mentioned defect determination condition includes a condition that current flows from the voltage conversion unit 30 side to the first power path 81 side via the second element unit 22. That is, in the representative example, when the voltage of the first power path 81 is equal to or lower than the first threshold value, the process of step S15 is performed on the condition that no current flows from the voltage conversion unit 30 side to the first power path 81 side via the second element unit 22. While allowing current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation, and allows current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold value and current flows from the voltage conversion unit 30 side to the first power path 81 side via the second element unit 22, the processes after step S16 are performed. The second element unit 22 blocks current from flowing from the voltage conversion unit 30 side to the first power path 81 side, and while allowing current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21, the control unit 16 causes the voltage conversion unit 30 to perform the second conversion operation.

[0081] The defect determination condition may include a condition that the voltage of the first power path 81 becomes equal to or lower than a second threshold value Vth2 that is lower than the low voltage threshold value Vth1 (the first threshold value). In this case, the process of step S15 is performed on the condition that the voltage of the first power path 81 is equal to or lower than the low voltage threshold value Vth1 (the first threshold value) and exceeds the second threshold value Vth2. While allowing current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation, and allows current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23. Then, when the voltage of the first power path 81 is equal to or lower than the second threshold value, the processes after step S16 are performed. The second element unit 22 blocks current from flowing from the voltage conversion unit 30 side to the first power path 81 side, and while allowing current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21, the control unit 16 causes the voltage conversion unit 30 to perform the second conversion operation

[0082] The failure determination condition may include a condition in which a predetermined failure signal is given to the in-vehicle control device 10 from an external device (for example, an external ECU) different from the in-vehicle control device 10. In this example, on the condition that the voltage of the first power path 81 is equal to or lower than the first threshold value and no failure signal is given from the external device, the process of step S15 is performed, and while allowing current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation, and allows current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold value and a failure signal is given from the external device, the processes after step S16 are performed, the current flowing from the voltage conversion unit 30 side to the first power path 81 side in the second element unit 22 is blocked, and while allowing current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21, the control unit 16 causes the voltage conversion unit 30 to perform the second conversion operation.

[0083] In the present embodiment, during a period in which the voltage conversion unit 30 is caused to perform the first conversion operation while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23, such as when performing the process of step S10 or the process of step S15, the control unit 16 makes the power supplied from the voltage conversion unit 30 to the fourth power path 84 side larger than the power supplied to the second power path 82 side via the third element unit 23.

[0084] 5. Examples of effects In the in-vehicle control device 10, when the second element unit 22 allows current to flow from the first power path 81 side to the voltage conversion unit 30 side and causes the voltage conversion unit 30 to perform the first conversion operation, the power storage unit 92 can be charged while applying a desired voltage to the fourth power path 84. On the other hand, when the first element unit 21 allows current to flow from the voltage conversion unit 30 side to the second power path 82 side and causes the voltage conversion unit 30 to perform the second conversion operation, power can be supplied to the second power path 82 while applying a desired voltage to the third power path 83. That is, this in-vehicle control device 10 can adjust the charging voltage when charging the power storage unit 92 and the discharging voltage when discharging the power storage unit 92 with a simpler configuration, and in some cases, the second element unit 22 can block current from flowing from the voltage conversion unit 30 side to the first power path 81 side. Furthermore, since the third element unit 23 is provided and allows current to flow from the power storage unit 92 side to the second power path 82 side, the power storage unit 92 can be discharged via a path different from the path for voltage adjustment by the voltage conversion unit 30. Furthermore, since the third element unit 23 can block current from flowing from the second power path 82 side to the power storage unit 92 side, in some cases, it is possible to block current from flowing into the power storage unit 92 from the second power path 82 side via the third element unit 23.

[0085] In the in-vehicle control device 10, since the fourth element unit 24 allows current to flow from the first power path 81 side to the second power path 82 side, the power based on the power supply unit 91 can be directly supplied to the second power path 82 via the fourth element unit 24. On the other hand, in some cases, the fourth element unit 24 can block current from flowing from the second power path 82 side to the first power path 81 side.

[0086] When the voltage of the first power path 81 exceeds the first threshold value, the in-vehicle control device 10 can supply the power based on the power supply unit 91 directly to the second power path 82 while suppressing losses by turning on the fourth element unit 24. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold value, the control unit 16 can turn off the fourth element unit 24 while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23. Therefore, while suppressing the influence of the first power path 81 on the second power path 82 via the fourth element unit 24, a discharge current can flow from the power storage unit 92 to the second power path 82 via the third element unit 23.

[0087] When the abnormality detection unit detects an abnormality in the fourth element unit 24, the in-vehicle control device 10 can turn on the first element unit 21 while allowing current to flow from the first power path 81 side to the third power path 83 side in the second element unit 22. Therefore, power can be supplied from the first power path 81 side to the second power path 82 side using the paths of the second element unit 22 and the first element unit 21. On the other hand, the first element unit 21 can also be turned off. In this case, it is possible to prevent current from flowing from the second power path 82 side into the third power path 83 side via the first element unit 21.

[0088] When the voltage of the first power path 81 is not large enough to reach the voltage threshold value to the extent that it exceeds the first threshold value, the in-vehicle control device 10 can supply the power based on the power supply unit 91 directly to the second power path 82 while suppressing losses by turning on the fourth element unit 24. On the other hand, when the voltage of the first power path 81 rises too much to the extent that it becomes equal to or higher than the voltage threshold value, the control unit 16 can turn off the fourth element unit 24 while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23. Therefore, while suppressing the influence of the overvoltage of the first power path 81 on the second power path 82 via the fourth element unit 24, a discharge current can flow from the power storage unit 92 to the second power path 82 via the third element unit 23.

[0089] When the voltage of the first power path 81 drops below the first threshold value, if a predetermined condition is satisfied, the in-vehicle control device 10 can cause the voltage conversion unit 30 to perform a first conversion operation and supply power to the power storage unit 92 side. While supplying power to the power storage unit 92 side in this way, it is also possible to supply power to the second power path 82 side via the third element unit 23.

[0090] When the voltage of the first power path 81 drops below the first threshold value, the in-vehicle control device 10 allows current to flow to the voltage conversion unit 30 side via the second element unit 22 on the condition that the defect determination condition is not satisfied, and causes the voltage conversion unit 30 to perform a first conversion operation to charge the power storage unit 92. On the other hand, when the defect determination condition is satisfied, this in-vehicle control device 10 can supply the voltage adjusted based on the voltage conversion operation of the voltage conversion unit 30 to the second power path 82 while blocking the reverse flow to the first power path 81 side.

[0091] When the voltage of the first power path 81 becomes less than or equal to the first threshold value and changes to a state where the defect determination condition is not satisfied, the in-vehicle control device 10 can quickly supply power from the power storage unit 92 to the second power path 82 by turning on the third element unit 23. When the switching occurs from a state where the defect determination condition is not satisfied to a state where it is satisfied when the voltage of the first power path 81 is less than or equal to the first threshold value, after the switching, while preventing the reverse flow to the first power path 81 side, the power whose voltage is adjusted by the second conversion operation can be supplied to the second power path 82 via the third power path 83 and the first element unit 21. Moreover, since this in-vehicle control device 10 can maintain the third element unit 23 in the on state before and after the switching, even if the rise of the output of the voltage conversion unit 30 is slow after the above switching, the power supply from the power storage unit 92 to the second power path 82 via the third element unit 23 can be continued. Further, when the voltage conversion unit 30 satisfies a predetermined operating condition after the switching, this in-vehicle control device 10 can switch the third element unit 23 to the off state to narrow the discharge path to the path of the first element unit 21 among the first element unit 21 and the third element unit 23.

[0092] When the voltage of the first power path 81 is equal to or lower than the first threshold value, in-vehicle control device 10 can confirm that no current flows to the first power path 81 side through the second element unit 22, that is, it is highly likely that no ground fault has occurred in the first power path 81, and then cause the voltage conversion unit 30 to perform a first conversion operation to charge the power storage unit 92. And this in-vehicle control device 10 can perform discharge through the third element unit 23 in parallel with the power supply to the power storage unit 92 side by the above first conversion operation. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold value and current flows to the first power path 81 side through the second element unit 22, that is, when there may be a ground fault in the first power path 81, the second element unit 22 can block the current from flowing to the first power path 81 side, and suppress the influence of the ground fault from reaching the third power path 83 side. And by allowing current to flow to the second power path 82 side in the first element unit 21 and causing the voltage conversion unit 30 to perform a second conversion operation, while suppressing the influence of the ground fault, the power whose voltage is adjusted by the voltage conversion unit 30 can be supplied to the second power path 82.

[0093] When the voltage of the first power path 81 is equal to or lower than the first threshold value, in-vehicle control device 10 can confirm that the voltage exceeds the second threshold value, that is, the voltage of the first power path 81 is not too low, and then cause the voltage conversion unit 30 to perform a first conversion operation to charge the power storage unit 92. And this in-vehicle control device 10 can perform discharge through the third element unit 23 in parallel with the power supply to the power storage unit 92 side by the above first conversion operation. On the other hand, when the voltage of the first power path 81 is equal to or lower than the second threshold value, that is, when the voltage of the first power path 81 is too low, the second element unit 22 can block the current from flowing to the first power path 81 side, so even if a ground fault has occurred in the first power path 81, the influence of the ground fault can be suppressed from reaching the third power path 83 side. And by allowing current to flow to the second power path 82 side in the first element unit 21 and causing the voltage conversion unit 30 to perform a second conversion operation, while suppressing the influence of the voltage drop in the first power path 81, the power whose voltage is adjusted by the voltage conversion unit 30 can be supplied to the second power path 82.

[0094] When the voltage of the first power path 81 is equal to or lower than the first threshold value, on condition that no fault signal is provided from an external device, the in-vehicle control device 10 causes the voltage conversion unit 30 to perform a first conversion operation, and can charge the power storage unit 92. Then, the in-vehicle control device 10 can perform discharge via the third element unit 23 in parallel with the power supply to the power storage unit 92 by the first conversion operation. On the other hand, when a fault signal is generated while the voltage of the first power path 81 is equal to or lower than the first threshold value, while blocking the current from flowing to the first power path 81 side in the second element unit 22, the in-vehicle control device 10 can cause the voltage conversion unit 30 to perform a second conversion operation while allowing the current to flow to the second power path 82 side in the first element unit 21. Therefore, even if a ground fault or the like occurs in the first power path 81 when a fault signal is generated, the power whose voltage is adjusted by the voltage conversion unit 30 can be supplied to the second power path 82 while suppressing the influence thereof.

[0095] When the in-vehicle control device 10 performs the first conversion operation and the discharge via the third element unit 23 in parallel, the charging power based on the first conversion operation can be made larger than the discharge power via the third element unit 23. Therefore, when the above parallel operation is performed, power can be supplied to the second conductive path while more reliably securing the charging current to the power storage unit 92.

[0096] When the output voltage of the power storage unit 92 drops below a predetermined value, the in-vehicle control device 10 can charge the power storage unit 92 by the first conversion operation.

[0097] <Second Embodiment> The following description relates to the second embodiment. The circuit configuration of the in-vehicle control device 210 according to the second embodiment shown in FIG. 14 is different from that of the in-vehicle control device 10 according to the first embodiment in that the fourth element section 24 is not provided, and the other circuit configurations are the same as those of the in-vehicle control device 10. The control of the in-vehicle control device 210 is different from the control in FIG. 2 in that the control of the fourth element section 24 is omitted and the processes of steps S4, S8, and S9 are omitted, and the other controls are the same as the control in FIG. 2. In the control of the in-vehicle control device 210 in FIG. 2, after step S3, the process of step S5 is performed.

[0098] In the in-vehicle control device 210 according to the second embodiment, when the process of step S6 is performed in the case where the voltage of the first power path 81 is in the above-described normal state, power supply is performed as shown in FIG. 15. On the other hand, when the process of step S15 is performed in the case where the voltage of the first power path 81 is equal to or lower than the low voltage threshold and the defect determination condition is not satisfied, power supply is performed as shown in FIG. 16. When the process of step S16 is performed immediately after the defect determination condition is satisfied in the case where the voltage of the first power path 81 is equal to or lower than the low voltage threshold, power supply is performed as shown in FIG. 17. On the other hand, when the process of step S19 is performed in the case where the above-described stop condition is satisfied, power supply is performed as shown in FIG. 18. Thus, even when the fourth element section 24 in the configuration of FIG. 1 does not exist, control similar to that of the first embodiment can be performed.

[0099] <Third Embodiment> The following description relates to the third embodiment. The circuit configuration of the in-vehicle control device 310 according to the third embodiment shown in FIG. 20 differs from that of the in-vehicle control device 10 according to the first embodiment only in that the second element section 22 in FIG. 1 is changed to a second element section 322, and the other circuit configurations are the same as those of the in-vehicle control device 10. The control performed by the in-vehicle control device 310 is that, when turning on the second element section in steps S3, S8, and S13 in FIG. 2, both semiconductor switches 322A and 322B are turned on, and when turning off the second element section in S16 and S19, both semiconductor switches 322A and 322B are turned off, the point that the second element section 322 is turned off in step S10, and the point that the second conversion operation is performed in step S11 are the only differences from the control in FIG. 2 of the first embodiment, and the other controls are the same as the control in FIG. 2 of the first embodiment.

[0100] In the in-vehicle control device 310 of FIG. 20, the second element unit 322 is configured to bidirectionally block the flow of current between the first power path 81 and the third power path 83 through itself when it is in the off state, and to allow the flow of current from the first power path 81 to the third power path 83 through itself when it is in the on state. The semiconductor switches 322A and 322B constituting the second element unit 322 are connected in opposite directions to each other and are both constituted by FETs. In the example of FIG. 1, the drain of the semiconductor switch 322A is short-circuited to the first power path 81, the drain of the semiconductor switch 322B is short-circuited to the third power path 83, and the sources of the semiconductor switch 322A and the semiconductor switch 322B are short-circuited. The off state of the second element unit 322 means that both the semiconductor switches 322A and 322B are in the off state. When the second element unit 322 is in the off state, energization through the second element unit 322 is blocked bidirectionally, and both the flow of current from the first power path 81 side to the third power path 83 side and the flow of current from the third power path 83 side to the first power path 81 side are blocked. The on state of the second element unit 322 means that both the semiconductor switches 322A and 322B are in the on state. When the second element unit 322 is in the on state, energization through the second element unit 322 is allowed bidirectionally, and both the flow of current from the first power path 81 side to the third power path 83 side and the flow of current from the third power path 83 side to the first power path 81 side are allowed.

[0101] Even in the in-vehicle control device 310 of FIG. 20, as in FIG. 2, on the condition that the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and is less than the overvoltage threshold (voltage threshold) greater than the low voltage threshold Vth1 (first threshold) (that is, when the answer in step S2 is No), the control unit 16 turns on the second element unit 322 in step S3. On the other hand, when the control unit 16 determines in step S2 of FIG. 2 that the voltage of the first power path 81 is equal to or higher than the overvoltage threshold (voltage threshold), in step S10, it performs a process different from the example of FIG. 2, turns on the first element unit 21, turns off the second element unit 22, turns on the third element unit 23, and turns off the fourth element unit 24. Then, in step S11 after that, it performs a process different from the example of FIG. 2 and causes the voltage conversion unit 30 to perform a second conversion operation. In this way, when the voltage of the first power path 81 is equal to or higher than the overvoltage threshold (voltage threshold), the control unit 16 allows current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21 by turning on the first element unit 21, turns off the second element unit 322, and causes the voltage conversion unit 30 to perform the second conversion operation in this state. When such an operation is performed, with the energization between the first power path 81 and the third power path 83 blocked bidirectionally, the voltage conversion unit 30 applies an output voltage to the third power path 83 based on the power from the power storage unit 92, and power is supplied from the third power path 83 to the second power path 82. During such a power supply operation, the fourth element unit 24 blocks the energization between the first power path 81 and the second power path 82 bidirectionally through itself. Also in this example, after the process of step S11, a determination process of step S12 is performed, and when the voltage of the first power path 81 becomes less than the overvoltage threshold (voltage threshold), the processes after step S3 may be performed.

[0102] When the voltage of the first power path 81 exceeds the low voltage threshold value Vth1 (first threshold value) and is less than the overvoltage threshold value (voltage threshold value), the second element unit 22 is turned on, and power supply from the first power path 81 side to the voltage conversion unit 30 side can be enabled. On the other hand, when the voltage of the first power path 81 rises too much to be equal to or higher than the overvoltage threshold value (voltage threshold value), the second element unit 22 is turned off, the energization from the first power path 81 side to the third power path 83 side is cut off, and the voltage conversion unit 30 can be made to perform a second conversion operation in a state where energization from the third power path 83 side to the second power path 82 side via the first element unit 21 is permitted. Specifically, in order to perform the above operation while turning off the fourth element unit 24, it is possible to stably supply the power whose voltage is adjusted by the voltage conversion unit 30 to the second power path 82 while suppressing the influence of the overvoltage of the first power path 81 from reaching the second power path 82.

[0103] <Other Embodiments> The present disclosure is not limited to the embodiments described by the above description and drawings. For example, the features of the above-described or below-described embodiments can be combined in any combination without contradiction. Also, any feature of the above-described or below-described embodiments can be omitted if it is not explicitly stated as essential. Furthermore, the above-described embodiments may be modified as follows.

[0104] In the above-described embodiment, the power storage unit 92 is provided outside the in-vehicle control device 10, but the power storage unit 92 may be included in the in-vehicle control device 10.

[0105] When the voltage of the first power path 81 exceeds the low voltage threshold value Vth1 (first threshold value) and is less than the overvoltage threshold value Vth3 (voltage threshold value) greater than the low voltage threshold value Vth1, the fourth element unit is turned on, but the fourth element unit may be turned on regardless of whether the voltage of the first power path 81 is less than the overvoltage threshold value Vth3 (voltage threshold value) when it exceeds the low voltage threshold value Vth1 (first threshold value).

[0106] In the above-described embodiment, the first element portion 21 is constituted by two FETs. However, as shown in FIG. 21(A), the first element portion 21 may be constituted by only the diode 191. In this case, it is sufficient that the conductive path 181A is electrically connected to the third power path 83 and the conductive path 181B is electrically connected to the second power path 82. Alternatively, as shown in FIG. 21(B), the first element portion 21 may be a switch portion in which a switch element 192A (e.g., FET) and a diode 192B are provided in series. In this case, it is sufficient that the conductive path 182A is electrically connected to the third power path 83 and the conductive path 182B is electrically connected to the second power path 82. Alternatively, as shown in FIG. 21(C), the first element portion 21 may be only a switch element 193 (e.g., FET). In this case, it is sufficient that the conductive path 183A is electrically connected to the third power path 83 and the conductive path 183B is electrically connected to the second power path 82. Alternatively, as shown in FIG. 21(D), the first element portion 21 may be a switch portion 194 composed of a known semiconductor switch other than FET or a mechanical relay. In this case, it is sufficient that the conductive path 184A is electrically connected to the third power path 83 and the conductive path 184B is electrically connected to the second power path 82.

[0107] In the first embodiment, a single FET is provided in the second element portion 22, and in the third embodiment, two FETs are provided, but the present invention is not limited to this example. For example, applying the configuration of FIG. 21(A), the second element portion 22 may be constituted by only the diode 191. In this case, it is sufficient that the conductive path 181A is electrically connected to the first power path 81 and the conductive path 181B is the third power path 83. Alternatively, applying the configuration of FIG. 21(B), the second element portion 22 may be a switch portion in which a switch element 192A (e.g., FET) and a diode 192B are provided in series. In this case, it is sufficient that the conductive path 182A is electrically connected to the first power path 81 and the conductive path 182B is the third power path 83. Alternatively, applying the configuration of FIG. 21(D), the second element portion 22 may be a switch portion 194 composed of a known semiconductor switch other than FET or a mechanical relay. In this case, it is sufficient that the conductive path 184A is electrically connected to the first power path 81 and the conductive path 184B is the third power path 83.

[0108] In the above-described embodiment, two FETs are provided in the third element section 23. However, the configuration of FIG. 21(A) may be applied, and the third element section 23 may be constituted only by the diode 191. In this case, the conductive path 181A may be electrically connected to the fourth power path 84, and the conductive path 181B may be electrically connected to the second power path 82. Alternatively, the configuration of FIG. 21(B) may be applied, and the third element section 23 may be a switch section in which the switch element 192A (for example, FET) and the diode 192B are provided in series. In this case, the conductive path 182A may be electrically connected to the fourth power path 84, and the conductive path 182B may be electrically connected to the second power path 82. Alternatively, the configuration of FIG. 21(C) may be applied, and the third element section 23 may be only the switch element 193 (for example, FET). In this case, the conductive path 183A may be electrically connected to the fourth power path 84, and the conductive path 183B may be electrically connected to the second power path 82. Alternatively, the configuration of FIG. 21(D) may be applied, and the third element section 23 may be a switch section 194 composed of a known semiconductor switch other than FET or a mechanical relay. In this case, the conductive path 184A may be electrically connected to the fourth power path 84, and the conductive path 184B may be electrically connected to the second power path 82.

[0109] In the above-described embodiment, two FETs are provided in the fourth element section 24. However, the configuration of FIG. 21(A) may be applied, and the fourth element section 24 may be constituted only by the diode 191. In this case, the conductive path 181A may be the first power path 81, and the conductive path 181B may be the second power path 82. Alternatively, the configuration of FIG. 21(B) may be applied, and the fourth element section 24 may be a switch section in which a switch element 192A (e.g., FET) and a diode 192B are provided in series. In this case, the conductive path 182A may be the first power path 81, and the conductive path 182B may be the second power path 82. Alternatively, the configuration of FIG. 21(C) may be applied, and the fourth element section 24 may be only a switch element 193 (e.g., FET). In this case, the conductive path 183A may be the first power path 81, and the conductive path 183B may be the second power path 82. Alternatively, the configuration of FIG. 21(D) may be applied, and the fourth element section 24 may be a switch section 194 composed of a known semiconductor switch other than FET or a mechanical relay. In this case, the conductive path 184A may be the first power path 81, and the conductive path 184B may be the second power path 82.

[0110] The in-vehicle control device 310 of the third embodiment has a configuration in which the second element section 22 of the in-vehicle control device 10 of the first embodiment is changed to the second element section 322. However, the in-vehicle control device 210 may be configured such that the second element section 22 is changed in the same manner as the second element section 322 in the in-vehicle control device 210 of the second embodiment. In this example, the processing other than steps S10 to S12 is performed in the same manner as in the second embodiment, and the processing of steps S10 to S12 is performed in the same manner as in the third embodiment, but it may be made different from the third embodiment in that the control of the fourth element section is omitted.

[0111] It should be considered that all the embodiments disclosed this time are illustrative and not restrictive in any way. The scope of the present invention is not limited to the embodiments disclosed this time, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Explanation of reference numerals

[0112] 2: In-vehicle system 3: In-vehicle power supply system 10: In-vehicle control device 16: Control unit 21: First element unit 21A: Semiconductor switch 21B: Semiconductor switch 22: Second element unit 23: Third element unit 23A: Semiconductor switch 23B: Semiconductor switch 24: Fourth element unit 24A: Semiconductor switch 24B: Semiconductor switch 30: Voltage conversion unit 41: Voltage detection unit 43: Voltage detection unit 44: Voltage detection unit 80: Power path 81: First power path 82: Second power path 83: Third power path 84: Fourth power path 89: Conductive path 91: Power supply unit 92: Energy storage unit 101: Load 210: In-vehicle control device 310: In-vehicle control device 322: Second element unit 322A: Semiconductor switch 322B: Semiconductor switch

Claims

1. An in - vehicle control device used in an in - vehicle system comprising a power supply unit for supplying power, a power storage unit different from the power supply unit, a first power path to which a voltage based on the power supply unit is applied, a second power path which is a path for supplying the power supplied from the first power path to a load, a third power path different from the first power path and the second power path, and a fourth power path to which a voltage based on the power storage unit is applied, the in - vehicle control device controlling power supply from the power storage unit, a voltage conversion unit that performs a first conversion operation of converting the voltage applied to the third power path and applying the output voltage to the fourth power path, and a second conversion operation of converting the voltage applied to the fourth power path and applying the output voltage to the third power path; a control unit for controlling the voltage conversion unit; a first element unit that can allow current to flow from the voltage conversion unit side to the second power path side and can block current from flowing from the second power path side to the voltage conversion unit side; a second element unit that can allow current to flow from the first power path side to the voltage conversion unit side and can block current from flowing from the voltage conversion unit side to the first power path side; a third element unit that can allow current to flow from the power storage unit side to the second power path side and can block current from flowing from the second power path side to the power storage unit side; comprising an in - vehicle control device.

2. The in - vehicle control device according to claim 1, further comprising a fourth element unit that can allow current to flow from the first power path side to the second power path side and can block current from flowing from the second power path side to the first power path side. The in - vehicle control device according to claim 1.

3. The fourth element unit is configured to bidirectionally block current from flowing between the first power path and the second power path through itself when it is in an off state, and to allow current to flow from the first power path to the second power path through itself when it is in an on state. When the voltage of the first power path exceeds a first threshold value, the control unit sets the fourth element unit to an on state. When the voltage of the first power path is equal to or less than the first threshold value, while allowing current to flow from the power storage unit side to the second power path side in the third element unit, the control unit sets the fourth element unit to an off state. When the voltage of the first power path exceeds a first threshold value, the control unit sets the fourth element unit to an on state. When the voltage of the first power path is equal to or less than the first threshold value, while allowing current to flow from the power storage unit side to the second power path side in the third element unit, the control unit sets the fourth element unit to an off state. The in - vehicle control device according to claim 2.

4. The in - vehicle control device according to claim 3, further comprising an abnormality detection unit for detecting an abnormality of the fourth element unit. When the first element unit is in the off state, it bidirectionally blocks the current flow between the third power path and the second power path through itself, and when it is in the on state, it allows the current to flow from the third power path to the second power path through itself. When the abnormality detection unit detects an abnormality in the fourth element unit, while allowing the current to flow from the first power path side to the third power path side in the second element unit, the control unit turns on the first element unit. The in-vehicle control device according to claim 2 or claim 3.

5. When the fourth element unit is in the off state, it bidirectionally blocks the current flow between the first power path and the second power path through itself, and when it is in the on state, it allows the current to flow from the first power path to the second power path through itself. When the voltage of the first power path exceeds the first threshold and is less than the voltage threshold greater than the first threshold, the control unit turns on the fourth element unit. When the voltage of the first power path is equal to or higher than the voltage threshold, while allowing the current to flow from the power storage unit side to the second power path side in the third element unit, the control unit turns off the fourth element unit. The in-vehicle control device according to claim 2 or claim 3.

6. When the voltage of the first power path is equal to or higher than the voltage threshold, while allowing the current to flow from the power storage unit side to the second power path side in the third element unit, the control unit causes the voltage conversion unit to perform the first conversion operation. The in-vehicle control device according to claim 5.

7. When the second element unit is in the off state, it bidirectionally blocks the current flow between the first power path and the third power path through itself, and when it is in the on state, it allows the current to flow from the first power path to the third power path through itself. On the condition that the voltage of the first power path exceeds the first threshold and is less than the voltage threshold greater than the first threshold, the control unit turns on the second element unit. When the voltage of the first power path is equal to or higher than the voltage threshold, while allowing the current to flow from the third power path side to the second power path side in the first element unit, the control unit turns off the second element unit and causes the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to any one of claims 1 to 3.

8. When a predetermined condition is satisfied when the voltage of the first power path is equal to or lower than a first threshold value, while allowing a current to flow from the power storage unit side to the second power path side in the third element unit, the control unit causes the voltage conversion unit to perform the first conversion operation The in-vehicle control device according to claim 1

9. The predetermined condition includes, on the condition that a predetermined defect determination condition is not satisfied On the condition that the defect determination condition is not satisfied when the voltage of the first power path is equal to or lower than the first threshold value, while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation When the defect determination condition is satisfied when the voltage of the first power path is equal to or lower than the first threshold value, while blocking a current from flowing from the voltage conversion unit side to the first power path side in the second element unit and allowing a current to flow from the third power path side to the second power path side in the first element unit, the control unit causes the voltage conversion unit to perform the second conversion operation The in-vehicle control device according to claim 8

10. The third element unit is configured to bidirectionally block a current from flowing between the fourth power path and the second power path through itself when it is in an off state, and allow a current to flow from the fourth power path to the second power path through itself when it is in an on state The control unit controls at least the on / off of the third element unit When the voltage of the first power path is equal to or lower than a first threshold value, when a switch occurs from a state where the defect determination condition is not satisfied to a state where it is satisfied, the control unit maintains the third element unit in an on state before and after the switch, and after the switch, blocks a current from flowing from the voltage conversion unit side to the first power path side in the second element unit and allows a current to flow from the third power path side to the second power path side in the first element unit, and the control unit causes the voltage conversion unit to perform the second conversion operation. When the voltage conversion unit satisfies a predetermined operating condition after the switch, the control unit switches the third element unit to an off state The in-vehicle control device according to claim 9

11. The defect determination condition includes a condition that a current flows from the voltage conversion unit side to the first power path side through the second element unit On the condition that no current flows from the voltage conversion unit side to the first power path side through the second element unit when the voltage of the first power path is equal to or lower than the first threshold value, while allowing current to flow from the first power path side to the voltage conversion unit side in the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation, and allows current to flow from the power storage unit side to the second power path side in the third element unit, When the voltage of the first power path is equal to or lower than the first threshold value and current flows from the voltage conversion unit side to the first power path side through the second element unit, the second element unit blocks the flow of current from the voltage conversion unit side to the first power path side, and while allowing current to flow from the third power path side to the second power path side in the first element unit, the control unit causes the voltage conversion unit to perform the second conversion operation The in-vehicle control device according to claim 9 or claim 10.

12. The fault determination condition includes a condition that the voltage of the first power path becomes equal to or lower than a second threshold value that is lower than the first threshold value. On the condition that the voltage of the first power path is equal to or lower than the first threshold value and exceeds the second threshold value, while allowing current to flow from the first power path side to the voltage conversion unit side in the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation, and allows current to flow from the power storage unit side to the second power path side in the third element unit, When the voltage of the first power path is equal to or lower than the second threshold value, the second element unit blocks the flow of current from the voltage conversion unit side to the first power path side, and while allowing current to flow from the third power path side to the second power path side in the first element unit, the control unit causes the voltage conversion unit to perform the second conversion operation The in-vehicle control device according to claim 9 or claim 10.

13. The fault determination condition includes a condition that a predetermined fault signal is given to the in-vehicle control device from an external device different from the in-vehicle control device. On the condition that the voltage of the first power path is less than or equal to the first threshold value and the defect signal is not given from the external device, while allowing current to flow from the first power path side to the voltage conversion unit side in the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation, and allows current to flow from the power storage unit side to the second power path side in the third element unit. When the voltage of the first power path is less than or equal to the first threshold value and the defect signal is given from the external device, the control unit cuts off the current flowing from the voltage conversion unit side to the first power path side in the second element unit, and allows the current to flow from the third power path side to the second power path side in the first element unit while causing the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to claim 9 or claim 10.

14. During the period when the control unit causes the voltage conversion unit to perform the first conversion operation while allowing current to flow from the power storage unit side to the second power path side in the third element unit, the control unit makes the power supplied from the voltage conversion unit to the fourth power path side larger than the power supplied to the second power path side via the third element unit. The in-vehicle control device according to any one of claims 8 to 10.

15. When the voltage of the first power path exceeds the first threshold value and the output voltage of the power storage unit is less than or equal to a predetermined value, while allowing current to flow from the first power path side to the voltage conversion unit side in the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation. The in-vehicle control device according to any one of claims 3, 8, 9, and 10.

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