Vehicle-mounted control devices

Abstract

A voltage conversion unit (30) carries out a first conversion operation for converting a voltage applied to a third power path (83) and applying the output voltage to a fourth power path (84) and a second conversion operation for converting the voltage applied to the fourth power path (84) and applying the output voltage to the third power path (83). A control unit (16) controls the voltage conversion unit (30). A first element unit (21) can permit the flow of current from a first power path (81) towards the third power path (83), and can shut off the flow of current from the third power path (83) towards the first power path (81). A second element unit (22) can permit the flow of current from an intermediate conductive path (89) between a first power storage unit (92A) and a second power storage unit (92B) towards a second power path (82), and can shut off the flow of current from the second power path (82) towards the intermediate conductive path (89).

Description

Technical Field

[0001] This 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 a 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] This disclosure relates to an in-vehicle control device capable of backup operation by supplying power based on an energy storage unit, and aims to provide a technology that allows for adjustment of the charging voltage when charging the energy storage unit and the discharge voltage when discharging the energy storage unit with a simpler configuration, and that allows the energy storage unit to be discharged via a path separate from the path used to adjust the voltage. [Means for solving the problem]

[0006] The in-vehicle control device disclosed herein is An in-vehicle control device for use in an in-vehicle system comprising a power supply unit that supplies power, a power storage unit different from the power supply unit, a first power line through which power is supplied from the power supply unit, and a second power line that is a path for supplying power supplied from the first power line to the load side, which controls the power supply from the power storage unit, A voltage conversion unit is provided between the second power circuit and the energy storage unit and performs a first conversion operation which converts the voltage applied to the third power circuit provided on the second power circuit side and applies an output voltage to the fourth power circuit provided on the energy storage unit side, and a second conversion operation which converts the voltage applied to the fourth power circuit and applies an output voltage to the third power circuit. A control unit that controls the voltage conversion unit, A first element unit that can allow current to flow from the first power line side to the third power line side and can block current from flowing from the third power line side to the first power line side, Equipped with, The energy storage unit comprises a first energy storage unit and a second energy storage unit that is positioned at a lower potential than the first energy storage unit and connected in series with the first energy storage unit. Furthermore, the device includes a second element that allows current to flow from the intermediate conductive path between the first and second energy storage units to the second power path, and that can block current from flowing from the second power path to the intermediate conductive path. [Effects of the Invention]

[0007] The technology disclosed herein allows for adjustment of the charging voltage when charging the energy storage unit and the discharge voltage when discharging the energy storage unit with a simpler configuration, and also allows the energy storage unit to be discharged via a path separate from the voltage adjustment path. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic circuit diagram showing an example of an in-vehicle system including an in-vehicle control device according to the first embodiment. [Figure 2] Figure 2 is an explanatory diagram illustrating an example of the operation in which the energy storage unit is charged when the first power line is in a normal state. [Figure 3] Figure 3 is an explanatory diagram illustrating an example of the operation in which power is supplied to the second energy storage unit when the first power line is in a normal state. [Figure 4] Figure 4 is an explanatory diagram illustrating an example of the operation in which power from the power supply unit is converted to voltage by the voltage conversion unit and supplied to the second power line. [Figure 5] Figure 5 is an explanatory diagram illustrating an example of a power supply operation performed by the in-vehicle control device of the first embodiment immediately after the first power line is below the first threshold and the failure determination condition is met. [Figure 6] Figure 6 is an explanatory diagram illustrating an example of a power supply operation performed by the in-vehicle control device of the first embodiment after a certain amount of time has elapsed since the failure determination condition was met. [Figure 7] Figure 7 is an explanatory diagram showing an example of a modification to the element section. [Modes for carrying out the invention]

[0009] The embodiments relating to this disclosure are listed and illustrated below.

[0010] [1] An in-vehicle control device used in an in-vehicle system comprising a power supply unit that supplies power, a power storage unit different from the power supply unit, a first power line through which power from the power supply unit is supplied, and a second power line that is a path for supplying power supplied from the first power line to the load side, which controls the power supply from the power storage unit, A voltage conversion unit is provided between the second power circuit and the energy storage unit and performs a first conversion operation which converts the voltage applied to the third power circuit provided on the second power circuit side and applies an output voltage to the fourth power circuit provided on the energy storage unit side, and a second conversion operation which converts the voltage applied to the fourth power circuit and applies an output voltage to the third power circuit. A control unit that controls the voltage conversion unit, A first element unit that can allow current to flow from the first power line side to the third power line side and can block current from flowing from the third power line side to the first power line side, Equipped with, The energy storage unit comprises a first energy storage unit and a second energy storage unit that is positioned at a lower potential than the first energy storage unit and connected in series with the first energy storage unit. Furthermore, the system includes a second element that allows current to flow from the intermediate conductive path between the first and second energy storage units to the second power path, and that can block current from flowing from the second power path to the intermediate conductive path. In-vehicle control device.

[0011] The above-described in-vehicle control measure allows the energy storage unit to be charged while applying a desired voltage to the fourth power line by causing the voltage conversion unit to perform a first conversion operation while the first element unit is allowing current to flow from the first power line side to the third power line side. Furthermore, the above-described in-vehicle control measure allows power to be supplied to the second power line while applying a desired voltage to the third power line by causing the voltage conversion unit to perform a second conversion operation. In other words, this in-vehicle control device can adjust the charging voltage when charging the energy storage unit and the discharge voltage when discharging the energy storage unit with a simpler configuration, and in some cases, the first element unit can block the flow of current from the third power line side to the first power line side. Moreover, since a second element unit is provided and current can flow from the intermediate conductive path between the first and second energy storage units to the second power line side, the second energy storage unit can be discharged via a path different from the path through which the voltage is adjusted by the voltage conversion unit. Furthermore, since the second element can block the flow of current from the second power line to the intermediate conductive line, it can, in some cases, block the flow of current from the second power line to the second energy storage unit via the second element. Moreover, with a configuration in which the second energy storage unit is discharged via the second element, the output voltage decreases compared to a configuration in which the energy storage unit is discharged directly. Therefore, it is easier to prevent the voltage input to the load from exceeding the load's rated voltage.

[0012] [2] A third element section provided between the fourth power line and the fifth power line to which the output voltage of the energy storage unit is applied, The structure comprises a third element section and a first energy storage section connected in series, and a fourth element section provided in parallel with the structure, The third element section blocks the flow of current from the fifth power path to the fourth power path when it is in the off state, and allows current to flow from the fifth power path to the fourth power path when it is in the on state. The fourth element section blocks the flow of current from the fourth power path to the intermediate conductive path when it is in the off state, and allows current to flow from the fourth power path to the intermediate conductive path when it is in the on state. When the control unit turns on the third element unit, turns off the fourth element unit, and causes the voltage conversion unit to perform the first conversion operation, power is supplied from the voltage conversion unit to the power storage unit. When the control unit turns off the third element unit, turns on the fourth element unit, and causes the voltage conversion unit to perform the first conversion operation, power is supplied from the voltage conversion unit to the second power storage unit through the fourth element unit. The in-vehicle control device according to [1].

[0013] The in-vehicle control device can selectively supply power from the voltage conversion unit to the power storage unit and supply power to the second power storage unit bypassing the first power storage unit.

[0014] (3) Allowing current to flow from the first power path side to the third power path side in the first element unit and allowing current to flow from the intermediate conduction path side to the second power path side in the second element unit, while the control unit turns off the third element unit, turns on the fourth element unit, and causes the voltage conversion unit to perform the first conversion operation. The in-vehicle control device according to [2].

[0015] Even if current flows from the intermediate conduction path side to the second power path side through the second element unit in the in-vehicle control device, power is supplied to the intermediate conduction path through the first element unit and the fourth element unit, so that a voltage drop of the second power storage unit can be suppressed. Further, thereby, a voltage increase of the first power storage unit due to a voltage drop of the second power storage unit can be suppressed, and thus, deterioration of the first power storage unit can be suppressed.

[0016] (4) The control unit makes the power supplied from the voltage conversion unit to the intermediate conduction path side through the fourth element unit larger than the power supplied from the intermediate conduction path side to the second power path side through the second element unit. The in-vehicle control device according to [3].

[0017] The above-described in-vehicle control device can supply greater power to the intermediate conductive path even if current flows from the intermediate conductive path to the second power path via the second element section. Therefore, the above-described in-vehicle control device can supply power to the second power path while more reliably securing the charging current to the second energy storage section.

[0018] [5] The control unit, When the voltage of the energy storage unit is below a predetermined lower limit voltage, the voltage conversion unit is instructed to start the first conversion operation, while the third element unit is turned on and the fourth element unit is turned off, so that the voltage applied to the fourth power path becomes the first target value. When the voltage of the energy storage unit reaches a charging completion voltage that is equal to or greater than the lower limit voltage, the third element unit is turned off and the fourth element unit is turned on, and the voltage conversion unit is instructed to perform the first conversion operation so that the voltage applied to the fourth power path becomes a second target value that is smaller than the first target value. An in-vehicle control device as described in any one of [2] to [4].

[0019] The above-described in-vehicle control device can charge the energy storage unit with power from the voltage conversion unit when the voltage of the energy storage unit is below the lower limit voltage, and when the energy storage unit reaches the charging completion voltage, it can supply power to the second energy storage unit at a lower output voltage.

[0020] [6] When the voltage of the first power path is below the first threshold and the predetermined failure determination condition is not met, the control unit allows current to flow from the first power path side to the third power path side in the first element section, and allows current to flow from the intermediate conductive path side to the second power path side in the second element section, while the control unit turns off the third element section, turns on the fourth element section, and causes the voltage conversion section to perform the first conversion operation. When the failure determination condition is met, and the voltage of the first power path is below the first threshold, the first element unit blocks the flow of current from the third power path to the first power path, and the second element unit blocks the flow of current from the second power path to the intermediate conductive path, while the control unit turns on the third element unit, turns off the fourth element unit, and causes the voltage conversion unit to perform the second conversion operation. The in-vehicle control device described in [5].

[0021] The above-described in-vehicle control device can, even when the voltage of the first power line drops below a first threshold, supply power from the second energy storage unit to the second power line via the second element unit, while simultaneously converting the voltage of the power supply unit in the voltage conversion unit and supplying it to the intermediate conductive line side, provided that the failure detection condition is not met. On the other hand, when the failure detection condition is met, this in-vehicle control device can, while blocking reverse current to the first power line, convert the voltage of the energy storage unit in the voltage conversion unit and supply it to the second power line.

[0022] [7] The second element is configured to bidirectionally block the flow of current between the intermediate conductive path and the second power path when it is in the off state, and to allow current to flow from the intermediate conductive path to the second power path when it is in the on state. The control unit controls at least the on / off state of the second element, If the voltage of the first power line is below the first threshold, and a switch occurs from a state where the failure determination condition is not met to a state where it is met, the control unit maintains the second element unit in the ON state before and after the switch. After the switch, the control unit switches the third element unit to the ON state and the fourth element unit to the OFF state while blocking the flow of current from the third power line side to the first power line side in the first element unit, causing the voltage conversion unit to perform the second conversion operation. If the voltage conversion unit satisfies predetermined operating conditions after the switch, the control unit switches the second element unit to the OFF state. The in-vehicle control device described in [6].

[0023] The above-described in-vehicle control device can quickly supply power from the second energy storage unit to the second power circuit by turning on the second element unit when the voltage of the first power circuit changes to a state where it is below the first threshold and the failure detection condition is not met. Furthermore, when a switch occurs from a state where the failure detection condition is not met to a state where it is met while the voltage of the first power circuit is below the first threshold, the device can supply power whose voltage has been adjusted by the second conversion operation to the second power circuit via the third power circuit, while preventing reverse current to the first power circuit. Moreover, since this in-vehicle control device can maintain the second element unit in the ON state before and after the switch, it can continue to supply power from the second energy storage unit to the second power circuit via the second element unit even if the rise time of the output of the voltage conversion unit is slow after the switch. Furthermore, this in-vehicle control device can narrow the discharge path to the path of the second element and the third power path among the third power paths by switching the second element to the off state when the voltage conversion unit satisfies predetermined operating conditions after switching.

[0024] [8] The failure determination condition includes the condition that current flows from the third power line side through the first element to the first power line side, When the voltage of the first power path is below the first threshold and no current flows from the third power path side through the first element section to the first power path side, the control unit turns off the third element section, turns on the fourth element section, and causes the voltage conversion section to perform the first conversion operation, while allowing current to flow from the first power path side to the third power path side in the first element section, When the voltage of the first power path is below the first threshold and current flows from the third power path through the first element to the first power path, the control unit turns on the third element and turns off the fourth element, while blocking the flow of current from the third power path to the first power path in the first element, causing the voltage conversion unit to perform the second conversion operation. The vehicle-mounted control device described in [6] or [7].

[0025] The above-described in-vehicle control device can, when the voltage of the first power line is below a first threshold, confirm that no current flows to the first power line through the first element unit, i.e., that there is a high probability that a ground fault has not occurred in the first power line, and then have the voltage conversion unit perform the first conversion operation to charge the second energy storage unit. In parallel with supplying power to the second energy storage unit through the first conversion operation, this in-vehicle control device can discharge through the second element unit. On the other hand, if the voltage of the first power line is below a first threshold and current flows to the first power line through the first element unit, i.e., if there is a possibility that a ground fault has occurred in the first power line, the first element unit can block the flow of current to the first power line, thereby suppressing the effects of the ground fault on the third power line. Then, by having the voltage conversion unit perform the second conversion operation, power whose voltage has been adjusted by the voltage conversion unit can be supplied to the second power line while suppressing the effects of the ground fault.

[0026] [9] The failure determination condition includes a condition in which the voltage of the first power line is less than or equal to a second threshold, which is lower than the first threshold, When the voltage of the first power path is below the first threshold and exceeds the second threshold, the control unit turns off the third element and turns on the fourth element, while allowing current to flow from the first power path to the third power path in the first element section, and causes the voltage conversion section to perform the first conversion operation, and also allows current to flow from the intermediate conductive path to the second power path in the second element section. If the voltage of the first power path is below the second threshold, the control unit blocks the flow of current from the third power path to the first power path in the first element unit, turns on the third element unit, turns off the fourth element unit, and causes the voltage conversion unit to perform the second conversion operation. An in-vehicle control device as described in any one of [6] to [8].

[0027] The above-described in-vehicle control device, when the voltage of the first power line is below the first threshold, can confirm that it exceeds the second threshold, i.e., that the voltage of the first power line is not too low, and then have the voltage conversion unit perform the first conversion operation to charge the second energy storage unit. In parallel with supplying power to the second energy storage unit through the first conversion operation, this in-vehicle control device can discharge through the second element unit. On the other hand, when the voltage of the first power line is below the second threshold, i.e., when the voltage of the first power line is too low, the first element unit can interrupt the flow of current to the first power line, thus suppressing the effects of a ground fault on the third power line even if a ground fault occurs in the first power line. By having the voltage conversion unit perform the second conversion operation, the power whose voltage has been adjusted by the voltage conversion unit can be supplied to the second power line while suppressing the effects of the voltage drop in the first power line.

[0028]

[10] The failure determination condition includes a condition in which a predetermined failure signal is supplied to the in-vehicle control device from an external device different from the in-vehicle control device, When the voltage of the first power path is below the first threshold and no loss signal is supplied from the external device, the control unit turns off the third element and turns on the fourth element, causing the voltage conversion unit to perform the first conversion operation, while allowing current to flow from the first power path to the third power path in the first element unit, When the voltage of the first power path is below the first threshold and the loss signal is supplied from the external device, the control unit blocks the flow of current from the third power path to the first power path in the first element unit, turns on the third element unit, turns off the fourth element unit, and causes the voltage conversion unit to perform the second conversion operation. An in-vehicle control device as described in any one of [6] through [9].

[0029] The above-described in-vehicle control device can, when the voltage of the first power line is below a first threshold, confirm that no failure signal is being supplied from an external device, and then have the voltage conversion unit perform a first conversion operation to charge the second energy storage unit. In parallel with supplying power to the second energy storage unit through the first conversion operation, this in-vehicle control device can also discharge power via the second element unit. On the other hand, when a failure signal occurs while the voltage of the first power line is below a first threshold, the first element unit can interrupt the flow of current to the first power line while simultaneously having the voltage conversion unit perform a second conversion operation. Therefore, even if a ground fault or the like occurs in the first power line when a failure signal occurs, the effects of the fault can be suppressed, and power with voltage adjusted by the voltage conversion unit can be supplied to the second power line.

[0030]

[11] A fifth element section is provided which allows current to flow from the third power line side to the second power line side and which can block current from flowing from the second power line side to the third power line side. An in-vehicle control device as described in any one of [1] through

[10] .

[0031] The above-mentioned in-vehicle control device can supply power to the second power circuit while applying a desired voltage to the third power circuit by causing the voltage conversion unit to perform a second conversion operation when the fifth element unit is in a state where current is allowed to flow from the third power circuit side to the second power circuit side.

[0032] <First Embodiment> 1. Overview of the in-vehicle system Figure 1 shows the in-vehicle system 2. The in-vehicle system 2 in Figure 1 comprises an in-vehicle power supply system 3 and a load 101. The in-vehicle system 2 is a system that supplies power to the load 101 by the in-vehicle power supply system 3 and operates the load 101.

[0033] Load 101 is an electrical component mounted in the vehicle. Load 101 operates by receiving power supplied from the on-board power supply system 3. The type of load 101 is not limited. Various known on-board components can be used as load 101. Load 101 may have multiple electrical components or may be a single electrical component.

[0034] The vehicle-mounted power supply system 3 is a system that supplies power to the load 101. The vehicle-mounted power supply system 3 supplies power to the load 101 using either the power supply unit 91 or the energy storage unit 92 as the power source. The vehicle-mounted power supply system 3 can supply power to the load 101 from the power supply unit 91, and if the power supply from the power supply unit 91 is interrupted due to a malfunction or the like, for example, the energy storage unit 92 can supply power to the load 101. Depending on the situation, the energy storage unit 92 may also be used as a power source to supply power to the load 101 when the power supply from the power supply unit 91 to the load 101 is not interrupted.

[0035] 2. Overview of the In-Vehicle Power Supply System The in-vehicle power supply system 3 includes a power supply unit 91, an energy storage unit 92, an in-vehicle control device 10, and the like. In the representative example shown in Figure 1, the first power line 81, the second power line 82, the third power line 83, the fourth power line 84, and the fifth power line 85 are configured as part of the in-vehicle control device 10. However, it is not necessary for any part or all of the first power line 81, the second power line 82, the third power line 83, the fourth power line 84, and the fifth power line 85 to be elements of the in-vehicle control device 10.

[0036] 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 energy storage unit, such as a lead-acid battery. The power supply unit 91 may also be composed of a battery other than a lead-acid battery (for example, a lithium-ion battery or other batteries), and may have a power supply means other than a battery in place of or in addition to a battery. In the example in Figure 1, the positive terminal of the power supply unit 91 is electrically connected to the first power line 81 in a short-circuit configuration. The negative terminal of the power supply unit 91 is electrically connected to ground in a short-circuit configuration. The power supply unit 91 applies a constant DC voltage to the first power line 81. The voltage applied by the power supply unit 91 to the first power line 81 may vary slightly from the constant value.

[0037] The energy storage unit 92 is a different power source from the power supply unit 91. The energy storage unit 92 is a power source that becomes a power supply source at least when the power supply from the power supply unit 91 is interrupted. The energy storage unit 92 is composed of known energy storage means, such as an electric double-layer capacitor (EDLC). The energy storage unit 92 may be composed of a capacitor other than an electric double-layer capacitor, and may be equipped with other energy storage means (such as a battery) in place of or in addition to the capacitor. In the example of Figure 1, the positive terminal of the energy storage unit 92 is electrically connected to the fifth power line 85 in a configuration that is short-circuited to the fifth power line 85. The negative terminal of the energy storage unit 92 is electrically connected to ground in a configuration that is short-circuited to ground. The output voltage of the energy storage unit 92 (the voltage applied to the fifth power line 85 by the energy storage unit 92) may be greater than, less than, or about the same as the output voltage of the power supply unit 91 (the voltage applied to the first power line 81 by the power supply unit 91).

[0038] The energy storage unit 92 comprises a first energy storage unit 92A and a second energy storage unit 92B. The second energy storage unit 92B is positioned at a lower potential than the first energy storage unit 92A and is connected in series with the first energy storage unit 92A. The positive terminal of the first energy storage unit 92A constitutes the positive terminal of the energy storage unit 92. The negative terminal of the first energy storage unit 92A is electrically connected to the positive terminal of the second energy storage unit 92B in a short-circuit configuration. The negative terminal of the second energy storage unit 92B constitutes the negative terminal of the energy storage unit 92.

[0039] In this specification, unless otherwise specified, voltage refers to the voltage relative to ground potential (e.g., 0V), and is the potential difference with respect to ground potential. For example, the voltage applied to the first power line 81 is the potential difference between the potential of the first power line 81 and ground potential.

[0040] The output voltage of the power supply unit 91 is applied to the first power line 81. The first power line 81 constitutes part or all of the power supply path between the power supply unit 91 and the first element unit 21. One end of the first power line 81 is electrically connected to the positive terminal of the power supply unit 91 in a short-circuit configuration. In the example of Figure 1, the other end of the first power line 81 is electrically connected to one end of the first element unit 21 (in the example of Figure 1, the source terminal, which is one end of the semiconductor switch constituting the first element unit 21) in a short-circuit configuration. Relays and fuses may be provided in the first power line 81. The first power line 81 functions, for example, to bring the positive terminal of the power supply unit 91 and one end of the first element unit 21 to the same potential or approximately the same potential.

[0041] The second power line 82 is a path that supplies power supplied from the first power line 81 to the load 101. The second power line 82 constitutes part or all of the power supply path between the fifth element unit 25 and the load 101. One end of the second power line 82 is electrically connected to the other end of the fifth element unit 25 (in the example shown in Figure 1, the drain terminal, which is the other end of the semiconductor switch 25B). The other end of the second power line 82 is electrically connected to the load 101 in a configuration that short-circuits one end of the load 101. The second other end of the second power line 82 is electrically connected to the other end of the second element unit 22 (in the example shown in Figure 1, the drain terminal, which is the other end of the semiconductor switch 22B) in a configuration that short-circuits it. Relays and fuses may be provided in the second power line 82. The second power line 82 functions, for example, to bring the other end of the fifth element section 25, the other end of the second element section 22, and one end of the load 101 to the same potential or approximately the same potential.

[0042] The third power line 83 is a power line different from the first power line 81 and the second power line 82. The third power line 83 is provided on the side of the voltage conversion unit 30 to the first power line 81 and on the side of the voltage conversion unit 30 to the second power line 82. One end of the third power line 83 is electrically connected to the other end of the first element unit 21 by short-circuiting it to the other end (in the example in Figure 1, the drain terminal, which is the other end of the semiconductor switch constituting the first element unit 21). The other end of the third power line 83 is electrically connected to one end of the voltage conversion unit 30 by short-circuiting it to one end of the voltage conversion unit 30. The second other end of the third power line 83 is electrically connected to one end of the fifth element unit 25 by short-circuiting it to one end (in the example in Figure 1, the drain terminal, which is one end of the semiconductor switch 25A). The third power line 83 functions, for example, to bring the other end of the first element section 21, one end of the fifth element section 25, and one end of the voltage conversion section 30 to the same potential or approximately the same potential.

[0043] The fourth power line 84 is a power line different from the first power line 81, the second power line 82, and the third power line 83. The fourth power line 84 is provided on the energy storage unit 92 side of the voltage conversion unit 30. One end of the fourth power line 84 is electrically connected to the other end of the voltage conversion unit 30 in a short-circuit configuration. The other end of the fourth power line 84 is electrically connected to one end of the third element unit 23 in a short-circuit configuration (in the example in Figure 1, the source terminal, which is one end of the semiconductor switch constituting the third element unit 23). The second other end of the fourth power line 84 is electrically connected to one end of the fourth element unit 24 in a short-circuit configuration (in the example in Figure 1, the drain terminal, which is one end of the semiconductor switch constituting the fourth element unit 24). The fourth power line 84 functions, for example, to bring the other end of the voltage conversion unit 30, one end of the third element unit 23, and one end of the fourth element unit 24 to the same potential or approximately the same potential.

[0044] The fifth power line 85 is a power line different from the first power line 81, the second power line 82, the third power line 83, and the fourth power line 84. One end of the fifth power line 85 is electrically connected to the other end of the third element section 23 by short-circuiting it to the other end of the third element section 23 (in the example shown in Figure 1, the drain terminal, which is the other end of the semiconductor switch constituting the third element section 23). The other end of the fifth power line 85 is electrically connected to the positive terminal of the energy storage section 92 by short-circuiting it to the positive terminal of the energy storage section 92. The fifth power line 85 functions, for example, to bring the other end of the third element section 23 and the positive terminal of the energy storage section 92 to the same potential or approximately the same potential.

[0045] An intermediate conductive path 89 is provided between the first energy storage unit 92A and the second energy storage unit 92B. One end of the intermediate conductive path 89 is electrically connected to the negative terminal of the first energy storage unit 92A by being short-circuited to the negative terminal of the first energy storage unit 92A. The other end of the intermediate conductive path 89 is electrically connected to the positive terminal of the second energy storage unit 92B by being short-circuited to the positive terminal of the second energy storage unit 92B. The other end of the second intermediate conductive path 89 is electrically connected to the other end of the fourth element unit 24 by being short-circuited to the other end of the fourth element unit 24 (in the example shown in Figure 1, the source terminal, which is the other end of the semiconductor switch constituting the fourth element unit 24). The third end of the intermediate conductive path 89 is electrically connected to one end of the second element unit 22 by being short-circuited to the drain terminal, which is one end of the semiconductor switch 22A, in the example shown in Figure 1. The intermediate conductive path 89 functions, for example, to bring the negative terminal of the first energy storage unit 92A, the positive terminal of the second energy storage unit 92B, the other end of the fourth element unit 24, and one end of the second element unit 22 to the same potential or approximately the same potential.

[0046] 3. Details of the in-vehicle control system The in-vehicle control device 10 is used in the in-vehicle system 2 and controls the power supply from the energy storage unit 92. The in-vehicle control device 10 is a backup control device capable of controlling the backup operation of outputting power from the energy storage unit 92. The in-vehicle control device 10 includes a first power line 81, a second power line 82, a third power line 83, a fourth power line 84, a fifth power line 85, a control unit 16, a voltage conversion unit 30, a first element unit 21, a second element unit 22, a third element unit 23, a fourth element unit 24, a fifth element unit 25, voltage detection units 41, 43, 44, and the like.

[0047] In the representative example shown in Figure 1, the first element section 21 is composed of one semiconductor switch. The second element section 22 is composed of two semiconductor switches 22A and 22B. The third element section 23 is composed of one semiconductor switch. The fourth element section 24 is composed of one semiconductor switch. The fifth element section 25 is composed of two semiconductor switches 25A and 25B. In the example shown in Figure 1, the semiconductor switches constituting the first element section 21, the second element section 22, the third element section 23, the fourth element section 24, and the fifth element section 25 are all N-channel type FETs (Field Effect Transistors).

[0048] The first element unit 21 is configured to allow current to flow from the first power line 81 to the third power line 83 (i.e., the voltage conversion unit 30), and to block current from flowing from the third power line 83 (i.e., the voltage conversion unit 30) to the first power line 81. In the example shown in Figure 1, the drain of the first element unit 21 is electrically connected to short-circuit the third power line 83, and the source of the first element unit 21 is electrically connected to short-circuit the first power line 81. When the first element unit 21 is ON, current is allowed to flow in both directions through the first element unit 21. When the first element unit 21 is OFF, current is blocked from flowing from the third power line 83 to the first power line 81 through the first element unit 21.

[0049] The second element section 22 can allow current to flow from the intermediate conductive path 89 to the second power path 82. The second element section 22 can block current from flowing from the second power path 82 to the intermediate conductive path 89. The semiconductor switches 22A and 22B constituting the second element section 22 are connected in opposite directions. In the example in Figure 1, the drain of semiconductor switch 22A is short-circuited to the intermediate conductive path 89, the drain of semiconductor switch 22B is short-circuited to the second power path 82, and the source of semiconductor switch 22A and the source of semiconductor switch 22B are short-circuited. The second element section 22 is in the off state when both semiconductor switches 22A and 22B are in the off state. When the second element section 22 is in the off state, current flow through the second element section 22 is interrupted in both directions, preventing current from flowing from the second power line 82 side through the second element section 22 to the intermediate conductive line 89 side and from the intermediate conductive line 89 side through the second element section 22 to the second power line 82 side. The second element section 22 being in the on state means that both semiconductor switches 22A and 22B are in the on state. When the second element section 22 is in the on state, current flow through the second element section 22 is permitted in both directions, allowing current to flow from the second power line 82 side to the intermediate conductive line 89 side and from the intermediate conductive line 89 side to the second power line 82 side.

[0050] The third element unit 23 is provided between the fourth power line 84 and the fifth power line 85. In other words, the third element unit 23 is provided between the voltage conversion unit 30 and the energy storage unit 92. When the third element unit 23 is in the off state, it blocks the flow of current from the fifth power line 85 to the fourth power line 84 through it. When the third element unit 23 is in the on state, it allows current to flow from the fifth power line 85 to the fourth power line 84 through it. When the third element unit 23 is in the on state, current flow through the third element unit 23 is permitted in both directions. When the third element unit 23 is in the on state, the voltage of the fourth power line 84 and the voltage of the energy storage unit 92 are the same. In other words, when the third element unit 23 is in the on state, the output voltage of the energy storage unit 92 is applied to the fourth power line 84.

[0051] The fourth element unit 24 is provided in parallel with the configuration in which the third element unit 23 and the first energy storage unit 92A are connected in series. When the fourth element unit 24 is in the off state, it blocks the flow of current from the fourth power line 84 to the intermediate conductive line 89 through it. When the fourth element unit 24 is in the on state, it allows current to flow from the fourth power line 84 to the intermediate conductive line 89 through it. When the fourth element unit 24 is in the on state, current flow through the fourth element unit 24 is permitted in both directions. When the fourth element unit 24 is in the on state, the voltage of the fourth power line 84 and the voltage of the second energy storage unit 92B are the same. In other words, when the fourth element unit 24 is in the on state, the output voltage of the second energy storage unit 92B is applied to the fourth power line 84.

[0052] The fifth element section 25 can allow current to flow from the third power line 83 side (i.e., the voltage conversion section 30 side) to the second power line 82 side. The fifth element section 25 can block current from flowing from the second power line 82 side to the third power line 83 side (i.e., the voltage conversion section 30 side). The semiconductor switches 25A and 25B constituting the fifth element section 25 are connected in opposite directions. In the example in Figure 1, the drain of semiconductor switch 25A is short-circuited to the third power line 83, the drain of semiconductor switch 25B is short-circuited to the second power line 82, and the source of semiconductor switch 25A and the source of semiconductor switch 25B are short-circuited. The fifth element section 25 is in the off state when both semiconductor switches 25A and 25B are in the off state. When the fifth element section 25 is in the off state, current flow through the fifth element section 25 is interrupted in both directions, preventing current from flowing from the second power line 82 to the third power line 83 (i.e., the voltage conversion section 30) and from the third power line 83 (voltage conversion section 30) to the second power line 82. The fifth element section 25 being in the on state means that both semiconductor switches 25A and 25B are in the on state. When the fifth element section 25 is in the on state, current flow through the fifth element section 25 is permitted in both directions, allowing current to flow from the second power line 82 to the third power line 83 (i.e., the voltage conversion section 30) and from the third power line 83 (i.e., the voltage conversion section 30) to the second power line 82.

[0053] The voltage conversion unit 30 is composed of a known voltage conversion circuit, such as a DC-DC converter. In the example shown in Figure 1, the voltage conversion unit 30 performs voltage conversion between the third power line 83 and the fourth power line 84. The voltage conversion unit 30 is a device that performs a first conversion operation in which the voltage applied to the third power line 83 is converted to increase or decrease in voltage and applied to the fourth power line 84 as an output voltage, and a second conversion operation in which the voltage applied to the fourth power line 84 is converted to increase or decrease in voltage and applied to the third power line 83 as an output voltage. In this way, the voltage conversion unit 30 performs voltage conversion in both directions. The operation of the voltage conversion unit 30 is controlled by the control unit 16.

[0054] The control unit 16 controls the first element section 21, the second element section 22, the third element section 23, the fourth element section 24, the fifth element section 25, and the voltage conversion section 30. The control unit 16 is composed of an information processing device having information processing functions, calculation functions, control functions, etc. The device that controls the first element section 21, the second element section 22, the third element section 23, the fourth element section 24, the fifth element section 25, and the voltage conversion section 30 may be a single common device or may be composed of multiple devices.

[0055] The voltage detection unit 41 is a circuit that provides the control unit 16 with a detection value (e.g., an analog voltage value) that can identify the voltage applied to the first power line 81. The voltage detection unit 43 is a circuit that provides the control unit 16 with a detection value (e.g., an analog voltage value) that can identify the voltage applied to the third power line 83. The voltage detection unit 44 is a circuit that provides the control unit 16 with a detection value (e.g., an analog voltage value) that can identify the voltage applied to the fourth power line 84.

[0056] The control unit 16 can determine the output voltage of the energy storage unit 92 based on the value detected by the voltage detection unit 44 when the third element unit 23 is ON and the fourth element unit 24 is OFF. The control unit 16 can determine the output voltage of the second energy storage unit 92B based on the value detected by the voltage detection unit 44 when the third element unit 23 is OFF and the fourth element unit 24 is ON.

[0057] 4. Operation of the in-vehicle control device The control unit 16 turns on the first element unit 21 and the fifth element unit 25 when the vehicle starts. As a result, as shown in Figure 2, power from the power supply unit 91 is supplied to the second power line 82 via the first element unit 21 and the fifth element unit 25. The control unit 16 also keeps the second element unit 22 in the off state even when the vehicle starts. The control unit 16 can determine that the vehicle has started by receiving a signal indicating the on / off state of the start switch, or by receiving a signal output from an external ECU when the vehicle starts. The start switch is an ignition switch, a power switch, etc.

[0058] Furthermore, when the voltage of the energy storage unit 92 is below a predetermined lower limit voltage, the control unit 16 turns on the third element unit 23 and turns off the fourth element unit 24, while causing the voltage conversion unit 30 to perform a first conversion operation so that the voltage applied to the fourth power line 84 becomes a first target value. As a result, as shown in Figure 2, the power from the power supply unit 91 is converted to a voltage by the voltage conversion unit 30 and supplied to the energy storage unit 92, thereby charging the energy storage unit 92. The lower limit voltage is 0V or higher. The first target value is a value greater than the lower limit voltage. The first target value may also be greater than the rated voltage of the load 101.

[0059] When the voltage of the energy storage unit 92 reaches the charging completion voltage, which is equal to or greater than the lower limit voltage, the control unit 16 switches the third element unit 23 to the off state, switches the fourth element unit 24 to the on state, and switches the target voltage of the voltage conversion unit 30 from the first target value to the second target value. In other words, when the voltage of the energy storage unit 92 reaches the charging completion voltage, the control unit 16 switches the third element unit 23 to the off state and the fourth element unit 24 to the on state, and causes the voltage conversion unit 30 to perform the first conversion operation so that the voltage applied to the fourth power line 84 becomes a second target value which is smaller than the first target value. As a result, as shown in Figure 3, the power from the power supply unit 91 is converted to voltage by the voltage conversion unit 30 and supplied to the second energy storage unit 92B via the fourth element unit 24. The control unit 16 remains in standby mode while maintaining this state. The charging completion voltage may be the same as the lower limit voltage, or it may be a value greater than the lower limit voltage. The charging completion voltage may be the same as the first target value, or it may be a value smaller than the first target value.

[0060] When the vehicle starts and the voltage of the energy storage unit 92 is above the lower limit voltage, the control unit 16 may charge the second energy storage unit 92B without charging the entire energy storage unit 92. In other words, when the voltage of the energy storage unit 92 is above the lower limit voltage, the control unit 16 may turn off the third element unit 23 and turn on the fourth element unit 24, and cause the voltage applied to the fourth power line 84 to become a second target value which is smaller than the first target value.

[0061] The control unit 16 performs the above-described operations (specifically, the operation of supplying power to the second power line 82 via the fifth element unit 25, and the operation of supplying power to the energy storage unit 92 or the second energy storage unit 92B) when the voltage of the first power line 81 exceeds the first threshold and is less than an overvoltage threshold that is greater than the first threshold.

[0062] When the voltage of the first power line 81 is above a predetermined overvoltage threshold, the control unit 16 turns on the first element unit 21, the second element unit 22, the third element unit 23, the fourth element unit 24, and the fifth element unit 25, causing the voltage conversion unit 30 to perform the first conversion operation. As a result, when the voltage of the first power line 81 rises above the overvoltage threshold, as shown in Figure 4, the power from the power supply unit 91 is converted by the voltage conversion unit 30 and supplied to the second power line 82 via the fourth element unit 24 and the second element unit 22. The control unit 16 makes the power supplied from the voltage conversion unit 30 to the intermediate conductive line 89 side via the fourth element unit 24 greater than the power supplied to the second power line 82 side via the second element unit 22.

[0063] When the voltage of the first power line 81 is below a first threshold and the predetermined failure determination conditions are not met, the control unit 16 turns on the first element unit 21, the second element unit 22, the third element unit 23, the fourth element unit 24, and the fifth element unit 25, causing the voltage conversion unit 30 to perform the first conversion operation. As a result, as shown in Figure 4, the power from the power supply unit 91 is converted to voltage by the voltage conversion unit 30 and supplied to the second power line 82 via the fourth element unit 24 and the second element unit 22. The control unit 16 makes the power supplied from the voltage conversion unit 30 to the intermediate conductive line 89 side via the fourth element unit 24 greater than the power supplied to the second power line 82 side via the second element unit 22.

[0064] When the failure determination condition is met, such that the voltage of the first power line 81 is below the first threshold, the control unit 16 turns off the first element unit 21, turns off the second element unit 22, turns on the third element unit 23, turns off the fourth element unit 24, and turns on the fifth element unit 25, causing the voltage conversion unit 30 to perform the second conversion operation. As a result, as shown in Figure 6, the power from the energy storage unit 92 is converted to voltage by the voltage conversion unit 30 and supplied to the second power line 82 via the fifth element unit 25.

[0065] More specifically, when the voltage of the first power line 81 is below the first threshold, the control unit 16 maintains the second element unit 22 in the ON state before and after the switchover when the failure determination condition is not met to the state in which it is met. As a result, as shown in Figure 5, power from the second energy storage unit 92B is supplied to the second power line 82 via the second element unit 22. After the switchover, 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, turns off the fourth element unit 24, and turns off the fifth element unit 25, causing the voltage conversion unit 30 to perform the second conversion operation. When the voltage conversion unit 30 satisfies predetermined operating conditions after the switchover, the fifth element unit 25 is switched to the ON state. As a result, as shown in Figure 6, power from the energy storage unit 92 is converted by the voltage conversion unit 30 and supplied to the second power line 82 via the fifth element unit 25. Furthermore, the control unit 16 switches the second element unit 22 to the off state.

[0066] The predetermined operating conditions may be, for example, when the output voltage of the voltage conversion unit 30 reaches a predetermined operating start voltage, or when a predetermined time has elapsed since the above switching occurred, or it may be any other condition.

[0067] The failure detection conditions described above may include a condition in which current flows from the voltage conversion unit 30 to the first power line 81 via the first element unit 21. The failure detection conditions may also include a condition in which the voltage of the first power line 81 falls below a second threshold, which is lower than the first threshold. The failure detection conditions may also include a condition in which a predetermined failure signal is supplied to the on-board control device 10 from an external device different from the on-board control device 10.

[0068] 5. Examples of effects The in-vehicle control device 10 can charge the energy storage unit 92 while applying a desired voltage to the fourth power line 84 by having the voltage conversion unit 30 perform a first conversion operation when the first element unit 21 is allowing current to flow from the first power line 81 to the third power line 83. Furthermore, the in-vehicle control device 10 can supply power to the second power line 82 while applying a desired voltage to the third power line 83 by having the voltage conversion unit 30 perform a second conversion operation when the fifth element unit 25 is allowing current to flow from the third power line 83 to the second power line 82. In other words, this in-vehicle control device 10 can adjust the charging voltage when charging the energy storage unit 92 and the discharge voltage when discharging the energy storage unit 92 with a simpler configuration, and in some cases, the first element unit 21 can block the flow of current from the third power line 83 to the first power line 81. Furthermore, since the second element section 22 is provided, and current can flow from the intermediate conductive path 89 between the first energy storage section 92A and the second energy storage section 92B to the second power path 82, the second energy storage section 92B can be discharged via a path separate from the path through which the voltage is adjusted by the voltage conversion section 30. Moreover, since the second element section 22 can block the flow of current from the second power path 82 to the intermediate conductive path 89, it is possible to block the flow of current from the second power path 82 to the second energy storage section 92B via the second element section 22 in some cases. Furthermore, with the configuration in which the second energy storage section 92B is discharged via the second element section 22, the output voltage is lower compared to the configuration in which the energy storage section 92 is discharged directly. For this reason, it is easier to prevent the voltage input to the load 101 from exceeding the rated voltage of the load 101.

[0069] The in-vehicle control device 10 can selectively supply power from the voltage conversion unit 30 to the energy storage unit 92, and supply power to the second energy storage unit 92B, bypassing the first energy storage unit 92A.

[0070] Even if current flows from the intermediate conductive path 89 to the second power path 82 via the second element section 22, the in-vehicle control device 10 can still supply power to the intermediate conductive path 89 via the first element section 21 and the fourth element section 24, thereby suppressing a voltage drop in the second energy storage section 92B. Furthermore, this can suppress a voltage rise in the first energy storage section 92A caused by a voltage drop in the second energy storage section 92B, and consequently, can suppress deterioration of the first energy storage section 92A.

[0071] Even if current flows from the intermediate conductive path 89 to the second power path 82 via the second element section 22, the in-vehicle control device 10 can supply more power to the intermediate conductive path 89. Therefore, the in-vehicle control device 10 can supply power to the second power path 82 while more reliably securing the charging current to the second energy storage section 92B.

[0072] The in-vehicle control device 10 can charge the energy storage unit 92 with power from the voltage conversion unit 30 when the voltage of the energy storage unit 92 is below the lower limit voltage, and when the energy storage unit 92 reaches the charging completion voltage, it can supply power to the second energy storage unit 92B at a lower output voltage.

[0073] The in-vehicle control device 10 can supply power from the second energy storage unit 92B to the second power line 82 via the second element unit 22, while simultaneously converting the voltage of the power supply unit 91 in the voltage conversion unit 30 and supplying it to the intermediate conductive line 89, even if the voltage of the first power line 81 falls below the first threshold, as long as the failure detection condition is not met. On the other hand, when the failure detection condition is met, the in-vehicle control device 10 can block the reverse current to the first power line 81 while converting the voltage of the energy storage unit 92 in the voltage conversion unit 30 and supplying it to the second power line 82.

[0074] The in-vehicle control device 10 can quickly supply power from the second energy storage unit 92B to the second power line 82 by turning on the second element unit 22 when the voltage of the first power line 81 changes to a state where it is below the first threshold and the failure detection condition is not met. Furthermore, when a switch occurs from a state where the failure detection condition is not met when the voltage of the first power line 81 is below the first threshold to a state where it is met, after the switch, the power whose voltage has been adjusted by the second conversion operation can be supplied to the second power line 82 via the third power line 83 while preventing reverse current to the first power line 81. Moreover, since the in-vehicle control device 10 can maintain the second element unit 22 in the ON state before and after the switch, even if the rise time of the output of the voltage conversion unit 30 is slow after the switch, power can be continuously supplied from the second energy storage unit 92B to the second power line 82 via the second element unit 22. Furthermore, when the voltage conversion unit 30 satisfies predetermined operating conditions after switching, the in-vehicle control device 10 switches the second element unit 22 to the off state, thereby narrowing the discharge path to the path of the second element unit 22 and the third power path 83 of the third power path 83.

[0075] In a configuration where the fault detection condition includes a condition in which current flows from the voltage conversion unit 30 to the first power line 81 via the first element unit 21, the following effects can be obtained. When the voltage of the first power line 81 is below the first threshold, the on-board control device 10 can confirm that current does not flow to the first power line 81 via the first element unit 21, that is, that there is a high probability that no ground fault has occurred in the first power line 81, and then have the voltage conversion unit 30 perform the first conversion operation to charge the second energy storage unit 92B. Furthermore, the on-board control device 10 can discharge via the second element unit 22 in parallel with supplying power to the second energy storage unit 92B through the first conversion operation. On the other hand, if the voltage of the first power line 81 is below the first threshold and current flows to the first power line 81 side via the first element unit 21, that is, if there is a possibility of a ground fault occurring in the first power line 81, the first element unit 21 can block the flow of current to the first power line 81 side, thereby suppressing the effects of the ground fault on the third power line 83 side. Then, by having the voltage conversion unit 30 perform the second conversion operation, power whose voltage has been adjusted by the voltage conversion unit 30 can be supplied to the second power line 82 while suppressing the effects of the ground fault.

[0076] In a configuration where the failure detection condition includes a condition that the voltage of the first power line 81 is below a second threshold, which is lower than the first threshold, the following effects can be obtained. When the voltage of the first power line 81 is below the first threshold, the on-board control device 10 can confirm that it exceeds the second threshold, i.e., that the voltage of the first power line 81 is not too low, and then have the voltage conversion unit 30 perform the first conversion operation to charge the second energy storage unit 92B. The on-board control device 10 can then perform discharge via the second element unit 22 in parallel with supplying power to the second energy storage unit 92B through the first conversion operation. On the other hand, when the voltage of the first power line 81 is below the second threshold, i.e., when the voltage of the first power line 81 is too low, the first element unit 21 can block the flow of current to the first power line 81, thus preventing the effects of the ground fault from extending to the third power line 83 even if a ground fault occurs in the first power line 81. Then, by having the voltage conversion unit 30 perform a second conversion operation, the effects of the voltage drop in the first power line 81 can be suppressed, and power whose voltage has been adjusted by the voltage conversion unit 30 can be supplied to the second power line 82.

[0077] In a configuration where the failure detection condition includes a condition in which a predetermined failure signal is supplied to the on-board control device 10 from an external device different from the on-board control device 10, the following effects can be obtained. When the voltage of the first power line 81 is below a first threshold, the on-board control device 10 can confirm that no failure signal has been supplied from an external device, and then have the voltage conversion unit 30 perform a first conversion operation to charge the second energy storage unit 92B. The on-board control device 10 can then perform discharge via the second element unit 22 in parallel with supplying power to the second energy storage unit 92B through the first conversion operation. On the other hand, when a failure signal is generated while the voltage of the first power line 81 is below a first threshold, the first element unit 21 can interrupt the flow of current to the first power line 81 while having the voltage conversion unit 30 perform a second conversion operation. Therefore, even if a ground fault or the like occurs in the first power line 81 when a failure signal is generated, the voltage can be adjusted by the voltage conversion unit 30 and power can be supplied to the second power line 82 while suppressing its effects.

[0078] The in-vehicle control device 10 can supply power to the second power line 82 while applying a desired voltage to the third power line 83 by causing the voltage conversion unit 30 to perform a second conversion operation when the fifth element unit 25 is in a state where it allows current to flow from the voltage conversion unit 30 to the second power line 82.

[0079] <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. Moreover, the embodiments described above may be modified as follows.

[0080] In the embodiment described above, the energy storage unit 92 is provided outside the in-vehicle control device 10, but the energy storage unit 92 may also be included in the in-vehicle control device 10.

[0081] The fifth element section 25 is not required. In other words, an element does not need to be interposed between the third power path 83 and the second power path 82. For example, the third power path 83 and the second power path 82 may be configured to be short-circuited.

[0082] In the embodiments described above, a single FET is provided in the first element section 21, but the invention is not limited to this example. For example, the configuration of Figure 7(A) may be applied, and the first element section 21 may consist only of a diode 191. In this case, the conductive path 181A may be electrically connected to the first power path 81, and the conductive path 181B may be the third power path 83. Alternatively, the configuration of Figure 7(B) may be applied, and the first element section 21 may be a switch section in which a switch element 192A (e.g., an FET) and a diode 192B are provided in series. In this case, the conductive path 182A may be electrically connected to the first power path 81, and the conductive path 182B may be the third power path 83. Alternatively, the configuration of Figure 7(D) may be applied, and the first element section 21 may be a switch section 194 consisting of a known semiconductor switch other than an FET or a mechanical relay. In this case, the conductive path 184A may be electrically connected to the first power path 81, and the conductive path 184B may be the third power path 83. Alternatively, the configuration shown in Figure 7(E) may be applied, and the first element section 21 may be composed of two semiconductor switches 195A and 195B. In this case, the conductive path 185A may be electrically connected to the first power path 81, and the conductive path 185B may be the third power path 83. The two semiconductor switches 195A and 195B may be, for example, FETs, and may be arranged so that their sources are short-circuited.

[0083] In the embodiment described above, two FETs are provided in the second element section 22, but the configuration of Figure 7(A) may be applied and the second element section 22 may consist only of a diode 191. In this case, the conductive path 181A is electrically connected to the fourth power path 84, and the conductive path 181B is electrically connected to the second power path 82. Alternatively, the configuration of Figure 7(B) may be applied and the second element section 22 may be a switch section in which a switch element 192A (e.g., an FET) and a diode 192B are provided in series. In this case, the conductive path 182A is electrically connected to the fourth power path 84, and the conductive path 182B is electrically connected to the second power path 82. Alternatively, the configuration of Figure 7(C) may be applied and the second element section 22 may consist only of a switch element 193 (e.g., an FET). In this case, the conductive path 183A is electrically connected to the fourth power path 84, and the conductive path 183B is electrically connected to the second power path 82. Alternatively, the configuration shown in Figure 7(D) may be applied, and the second element section 22 may be a switch section 194 consisting of a known semiconductor switch other than an FET or a mechanical relay. In this case, it is sufficient that the conductive path 184A is electrically connected to the fourth power path 84 and the conductive path 184B is electrically connected to the second power path 82.

[0084] In the embodiments described above, a single FET is provided in the third element section 23, but the invention is not limited to this example. For example, applying the configuration of Figure 7(D), the third element section 23 may be a switch section 194 consisting of a known semiconductor switch other than an FET or a mechanical relay. In this case, the conductive path 184A may be the fourth power path 84, and the conductive path 184B may be the fifth power path 85. Alternatively, applying the configuration of Figure 7(E), the third element section 23 may be composed of two semiconductor switches 195A and 195B. In this case, the conductive path 185A may be the fourth power path 84, and the conductive path 185B may be the fifth power path 85. The two semiconductor switches 195A and 195B may be, for example, FETs, and may be arranged so that their sources are short-circuited.

[0085] In the embodiment described above, a single FET is provided in the fourth element section 24, but the invention is not limited to this example. For example, applying the configuration of Figure 7(D), the fourth element section 24 may be a switch section 194 consisting of a known semiconductor switch other than an FET or a mechanical relay. In this case, the conductive path 184A is electrically connected to the fourth power path 84, and the conductive path 184B is electrically connected to the intermediate conductive path 89. Alternatively, applying the configuration of Figure 7(E), the fourth element section 24 may be composed of two semiconductor switches 195A and 195B. In this case, the conductive path 185A is electrically connected to the fourth power path 84, and the conductive path 185B is electrically connected to the intermediate conductive path 89. The two semiconductor switches 195A and 195B are, for example, FETs, and may be arranged so that their sources are short-circuited.

[0086] In the embodiment described above, the fifth element section 25 is composed of two FETs, but as shown in Figure 7(A), the fifth element section 25 may be composed of only a diode 191. In this case, 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 Figure 7(B), the fifth element section 25 may be a switch section in which a switch element 192A (e.g., an FET) and a diode 192B are provided in series. In this case, 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 Figure 7(C), the fifth element section 25 may be composed of only a switch element 193 (e.g., an FET). In this case, 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 Figure 7(D), the fifth element section 25 may be a switch section 194 consisting of a known semiconductor switch other than an 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.

[0087] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is indicated by the claims, and all modifications within the meaning and scope of the claims are intended to be included. [Explanation of Symbols]

[0088] 2…In-vehicle systems 3. In-vehicle power supply system 10… Vehicle-mounted control devices 16…Control Unit 21...First element section 22...Second element section 22A…Semiconductor switch 22B... Semiconductor switch 23...Third element section 24...Fourth element section 25... Fifth element section 25A…Semiconductor switch 25B... Semiconductor switch 30...Voltage conversion section 41...Voltage detection unit 43...Voltage detection unit 44...Voltage detection unit 81…1st power path 82…Second power path 83…Third power path 84…4th power path 85…5th power path 89…Intermediate conductive path 91...Power supply section 92... Energy storage unit 92A...First Energy Storage Unit 92B…Second power storage unit 101... Load 181A…Conducting path 181B…Conducting path 182A…Conducting path 182B…Conducting path 183A…Conducting path 183B…Conducting path 184A…Conducting path 184B…Conducting path 185A…Conducting path 185B…Conducting path 191... Diode 192A…Switching element 192B…diode 193... Switching element 194... Switch section 195A…Semiconductor switch 195B... Semiconductor switch

Claims

1. An in-vehicle control device for use in an in-vehicle system comprising a power supply unit that supplies power, a power storage unit different from the power supply unit, a first power line through which power is supplied from the power supply unit, and a second power line that is a path for supplying power supplied from the first power line to the load side, which controls the power supply from the power storage unit, A voltage conversion unit is provided between the second power circuit and the energy storage unit and performs a first conversion operation which converts the voltage applied to the third power circuit provided on the second power circuit side and applies an output voltage to the fourth power circuit provided on the energy storage unit side, and a second conversion operation which converts the voltage applied to the fourth power circuit and applies an output voltage to the third power circuit. A control unit that controls the voltage conversion unit, A first element unit that can allow current to flow from the first power line side to the third power line side and can block current from flowing from the third power line side to the first power line side, Equipped with, The energy storage unit comprises a first energy storage unit and a second energy storage unit that is positioned at a lower potential than the first energy storage unit and connected in series with the first energy storage unit. Furthermore, the system includes a second element that allows current to flow from the intermediate conductive path between the first and second energy storage units to the second power path, and that can block current from flowing from the second power path to the intermediate conductive path. In-vehicle control device.

2. A third element unit is provided between the fourth power circuit and the fifth power circuit to which the output voltage of the energy storage unit is applied, The structure comprises a third element section and a first energy storage section connected in series, and a fourth element section provided in parallel with the structure, The third element section blocks the flow of current from the fifth power path to the fourth power path when it is in the off state, and allows current to flow from the fifth power path to the fourth power path when it is in the on state. The fourth element section blocks the flow of current from the fourth power path to the intermediate conductive path when it is in the off state, and allows current to flow from the fourth power path to the intermediate conductive path when it is in the on state. When the control unit turns on the third element and turns off the fourth element and causes the voltage conversion unit to perform the first conversion operation, power is supplied from the voltage conversion unit to the energy storage unit. When the control unit turns off the third element and turns on the fourth element, causing the voltage conversion unit to perform the first conversion operation, power is supplied from the voltage conversion unit to the second energy storage unit via the fourth element. The in-vehicle control device according to claim 1.

3. The control unit allows current to flow from the first power path to the third power path in the first element section, and allows current to flow from the intermediate conductive path to the second power path in the second element section, while the control unit turns off the third element section, turns on the fourth element section, and causes the voltage conversion unit to perform the first conversion operation. The in-vehicle control device according to claim 2.

4. The control unit makes the power supplied from the voltage conversion unit to the intermediate conductive path side via the fourth element unit greater than the power supplied from the intermediate conductive path side to the second power path side via the second element unit. The in-vehicle control device according to claim 3.

5. The control unit, When the voltage of the energy storage unit is below a predetermined lower limit voltage, the voltage conversion unit is instructed to start the first conversion operation, while the third element unit is turned on and the fourth element unit is turned off, so that the voltage applied to the fourth power path becomes the first target value. When the voltage of the energy storage unit reaches a charging completion voltage that is equal to or greater than the lower limit voltage, the third element unit is turned off and the fourth element unit is turned on, and the voltage conversion unit is instructed to perform the first conversion operation so that the voltage applied to the fourth power path becomes a second target value that is smaller than the first target value. An in-vehicle control device according to any one of claims 2 to 4.

6. When the voltage of the first power path is below a first threshold and the predetermined failure determination condition is not met, the control unit allows current to flow from the first power path side to the third power path side in the first element section, and allows current to flow from the intermediate conductive path side to the second power path side in the second element section, while the control unit turns off the third element section, turns on the fourth element section, and causes the voltage conversion section to perform the first conversion operation. When the voltage of the first power path is below the first threshold and the failure determination condition is met, the first element unit blocks the flow of current from the third power path to the first power path, and the second element unit blocks the flow of current from the second power path to the intermediate conductive path, while the control unit turns on the third element unit, turns off the fourth element unit, and causes the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to claim 5.

7. The second element is configured to bidirectionally block the flow of current between the intermediate conductive path and the second power path when it is in the off state, and to allow current to flow from the intermediate conductive path to the second power path when it is in the on state. The control unit controls at least the on / off state of the second element, If the voltage of the first power line is below the first threshold, and a switch occurs from a state where the failure determination condition is not met to a state where it is met, the control unit maintains the second element unit in the ON state before and after the switch. After the switch, the control unit switches the third element unit ON and the fourth element unit OFF while blocking the flow of current from the third power line side to the first power line side in the first element unit, causing the voltage conversion unit to perform the second conversion operation. If the voltage conversion unit satisfies predetermined operating conditions after the switch, the control unit switches the second element unit to the OFF state. The in-vehicle control device according to claim 6.

8. The failure determination condition includes the condition that current flows from the third power line side through the first element to the first power line side, When the voltage of the first power path is below the first threshold and no current flows from the third power path side through the first element section to the first power path side, the control unit turns off the third element section and turns on the fourth element section, causing the voltage conversion section to perform the first conversion operation, while allowing current to flow from the first power path side to the third power path side in the first element section, When the voltage of the first power path is below the first threshold and current flows from the third power path through the first element to the first power path, the control unit turns on the third element and turns off the fourth element, while blocking the flow of current from the third power path to the first power path in the first element, causing the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to claim 6.

9. The failure determination condition includes a condition in which the voltage of the first power line becomes less than or equal to a second threshold, which is lower than the first threshold. When the voltage of the first power path is below the first threshold and exceeds the second threshold, the control unit turns off the third element and turns on the fourth element, while allowing current to flow from the first power path to the third power path in the first element section, and causes the voltage conversion section to perform the first conversion operation, and also allows current to flow from the intermediate conductive path to the second power path in the second element section. If the voltage of the first power path is below the second threshold, the control unit blocks the flow of current from the third power path to the first power path in the first element unit, turns on the third element unit, turns off the fourth element unit, and causes the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to claim 6.

10. The failure determination condition includes a condition in which a predetermined failure signal is supplied to the in-vehicle control device from an external device different from the in-vehicle control device. When the voltage of the first power path is below the first threshold and no loss signal is supplied from the external device, the control unit turns off the third element and turns on the fourth element, while allowing current to flow from the first power path to the third power path in the first element section, causing the voltage conversion section to perform the first conversion operation, and also allowing current to flow from the intermediate conductive path to the second power path in the second element section. When the voltage of the first power path is below the first threshold and the loss signal is supplied from the external device, the control unit blocks the flow of current from the third power path to the first power path in the first element unit, turns on the third element unit, turns off the fourth element unit, and causes the voltage conversion unit to perform the second conversion operation. The in-vehicle control device according to claim 6.

11. The system includes a fifth element that allows current to flow from the third power line to the second power line and can block current from flowing from the second power line to the third power line. An in-vehicle control device according to any one of claims 1 to 4.

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