In-vehicle backup control device

Abstract

An in-vehicle backup control device (1) is provided with: a first supply circuit (31) capable of outputting power from a first power storage unit (71) to a load (93) via a first conductive line (111); a second supply circuit (32) capable of outputting power from the second power storage unit (72) to a load (92) via a second conductive line (112); and a first control unit (41) and a second control unit (42) that cause the first supply circuit (31) and the second supply circuit (32) to perform a backup operation when in an external state. When the first control unit (41) and the second control unit (42) are in an external state, the first control unit (41) and the second control unit (42) perform a predetermined priority control that prioritizes a first backup operation that supplies power to the load (93) by the second power storage unit (72) over a second backup operation that supplies power to the load (93) by the second power storage unit (72). And a second backup operation for supplying the power from the second power storage unit (72) to the load (93).

Description

Technical Field

[0001] The present disclosure relates to a backup control device for vehicle use. Background Art

[0002] Patent document 1 discloses a power storage device that supplies power from a power storage unit to a load when the voltage of a main power supply decreases. The control circuit of the power storage device controls a charging circuit to charge the power storage unit when the main power supply is normal. Furthermore, when the voltage of the main power supply decreases (for example, when the engine is started after idling stop), the control circuit turns on a switch disposed between the power storage unit and the load to supply power to the load. In addition, Patent document 1 states that the power storage device can also be applied to a power backup system when the main power supply is abnormal.

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2009-296808 Summary of the invention

[0004] Problems to be solved by the invention

[0005] The power storage device of Patent Document 1 is configured to supply power to a load to be backed up from one power storage unit. However, in such a configuration, there is only one power source for the load during backing up, and the power supply method is limited.

[0006] The present disclosure aims to enable the operation of using the first power storage unit and the operation of using the second power storage unit to be used together in power backup for a common load, and to give priority to the backup operation for the second load in power backup for a first load and a second load using the second power storage unit.

[0007] Technical solutions to solve problems

[0008] The vehicle-mounted backup control device as one of the present disclosures is used in a vehicle-mounted power supply system having a power supply unit and a power storage unit, and performs a backup operation of outputting power to the load based on the power from the power storage unit when the power supply from the power supply unit to the load is cut off or reduced in a predetermined external state, wherein: The vehicle-mounted backup control device comprises: a first supply circuit capable of outputting electric power based on a first power storage unit to a common load via a first conductive path, the first power storage unit being one of the power storage units; a second supply circuit capable of outputting electric power based on a second power storage unit to the common load via a second conductive path, the second power storage unit being one of the power storage units; and a control unit that causes the first supply circuit and the second supply circuit to perform the standby operation when in the external state; The second supply circuit supplies power based on the second power storage unit to one or more first loads and one or more second loads. The control unit performs a prescribed priority control when in the external state, and the prescribed priority control gives priority to a first backup action over a second backup action, wherein the first backup action supplies power to the first load based on the power of the second power storage unit, and the second backup action supplies power to the second load based on the power of the second power storage unit.

[0009] Effects of the Invention

[0010] The technology involved in the present disclosure can use both the operation using the first power storage unit and the operation using the second power storage unit in backing up power for the common load, and can prioritize the backing up operation for the second load when backing up power for the first and second loads using the second power storage unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 1 is a block diagram schematically illustrating an in-vehicle power supply system including the in-vehicle backup control device according to the first embodiment. Figure 2 is a more detailed representation Figure 1 A block diagram of a portion of a block diagram. Figure 3 This is a flowchart illustrating the flow of control performed by the vehicle-mounted backup control device according to the first embodiment. Figure 4 is with Figure 3 A subroutine related to power supply control to the third load in the flowchart. Figure 5 is with Figure 3 The fourth load in the flowchart and the subroutine related to the power supply control to the fourth load. Figure 6 Yes Figure 1 An explanatory diagram for explaining an example in which the actual open circuit voltage of the second power storage unit falls below the cutoff voltage before a predetermined time elapses in a vehicle-mounted backup control device. Figure 7 Yes Figure 1 An explanatory diagram for explaining an example in which a predetermined time elapses before an actual open circuit voltage of a second power storage unit falls below a cutoff voltage in a vehicle-mounted backup control device. Figure 8 1 is a block diagram schematically illustrating an in-vehicle power supply system including an in-vehicle backup control device according to a second embodiment. Fig. 91 is a block diagram schematically illustrating an in-vehicle power supply system including an in-vehicle backup control device according to a third embodiment. Fig.10 1 is a block diagram schematically illustrating an in-vehicle power supply system including an in-vehicle backup control device according to a fifth embodiment. Fig.11 1 is a block diagram schematically illustrating an in-vehicle power supply system including an in-vehicle backup control device according to a sixth embodiment. Fig.12 is a more detailed representation Fig.11 A block diagram of a portion of a block diagram. DETAILED DESCRIPTION

[0012] The following lists and illustrates the embodiments of the present disclosure. In addition, the features [1] to [9] illustrated below may be combined arbitrarily within the range of non-contradiction.

[0013] [1] A vehicle-mounted backup control device, used in a vehicle-mounted power supply system having a power supply unit and a power storage unit, which performs a backup operation of outputting power to the load based on power from the power storage unit when a predetermined external state occurs in which the power supply from the power supply unit to the load is cut off or reduced, wherein: The vehicle-mounted backup control device comprises: a first supply circuit capable of outputting electric power based on a first power storage unit to a common load via a first conductive path, the first power storage unit being one of the power storage units; a second supply circuit capable of outputting electric power based on a second power storage unit to the common load via a second conductive path, the second power storage unit being one of the power storage units; and a control unit that causes the first supply circuit and the second supply circuit to perform the standby operation when in the external state; The second supply circuit supplies power based on the second power storage unit to one or more first loads and one or more second loads. The control unit performs a prescribed priority control when in the external state, and the prescribed priority control gives priority to a first backup action over a second backup action, wherein the first backup action supplies power to the first load based on the power of the second power storage unit, and the second backup action supplies power to the second load based on the power of the second power storage unit.

[0014] The vehicle-mounted backup control device of the above-mentioned [1] is capable of performing a backup operation using the power storage unit in a specified external state in which the supply of power from the power supply unit is cut off or reduced. In the backup control device, power can be supplied from the first power storage unit and the second power storage unit to a specified common load. Therefore, during the backup operation, the backup control device can use both the operation of supplying power from the first power storage unit to the common load and the operation of supplying power from the second power storage unit to the common load. On this basis, through the specified priority control performed by the control unit, the first backup operation (the operation of supplying power based on the second power storage unit to the first load) can be prioritized over the second backup operation (the operation of supplying power based on the second power storage unit to the second load).

[0015] [2] The vehicle-mounted backup control device described in [1] has the following features. A third conductive path is provided, the third conductive path is a path for outputting power to the common load, and is a path for supplying power from the first conductive path and the second conductive path. The first supply circuit includes a first switch element, the first switch element is provided on the first conductive path, and can conduct power from the first power storage unit to the third conductive path when in an on state, and cut off power from the first power storage unit to the third conductive path when in an off state. The second supply circuit includes a second switch element, the second switch element is provided on the second conductive path, and can conduct power from the second power storage unit to the third conductive path when in an on state, and cut off power from the second power storage unit to the third conductive path when in an off state. The control unit includes a first control unit and a second control unit, the first control unit controls the first supply circuit, and the second control unit controls the second supply circuit. The first control unit and the second control unit can communicate with each other. During the second backup action, the first control unit sets the first switch element to an off state, and the second control unit sets the second switch element to an on state, so that the voltage based on the second power storage unit is applied to the third conductive path via the second conductive path. During the first backup action, the first control unit sets the first switch element to an on state, and the second control unit sets the second switch element to an off state, so that the voltage based on the first power storage unit is applied to the third conductive path via the first conductive path.

[0016] In the vehicle-mounted backup control device of the above-mentioned [2], the on-off state of the first switch element and the second switch element can be switched respectively by the control of the first control unit and the second control unit that can communicate with each other. Therefore, the first switch element and the second switch element can be selectively turned on. As a result, the first backup action and the second backup action can be switched well at a desired time.

[0017] [3] The vehicle-mounted backup control device described in [1] has the following features. It has: a third conductive line, the third conductive line is a path for outputting power to the common load and is a path for supplying power from the second conductive line; and a diode, which is provided between the first conductive line and the third conductive line, the anode of the diode being electrically connected to the first conductive line side, and the cathode of the diode being electrically connected to the third conductive line side. The first supply circuit has a first conversion unit, the first conversion unit steps up or steps down an input voltage based on the power from the first power storage unit, and applies an output voltage to the first conductive line. The second supply circuit has a second conversion unit, the second conversion unit steps up or steps down an input voltage based on the power from the second power storage unit, and applies an output voltage to the second conductive line. During the priority control, the control unit controls the output of the first conversion unit to the first conductive path and the output of the second conversion unit to the second conductive path in such a manner that the power based on the second power storage unit is supplied to the third conductive path via the second conductive path and the power based on the first power storage unit is cut off by the diode.

[0018] In the vehicle-mounted backup control device of the above-mentioned [3], when the priority control is performed by the control unit, the power based on the second power storage unit can be supplied to the third conductive line via the second conductive line. In the state where the output voltage is applied to the first conductive line by the first conversion unit, the power based on the first power storage unit is cut off by the diode, so that the backup preparation state for the common load can be set in a form in which the power consumption of the first power storage unit is suppressed. When switching from the state of supplying the power based on the second power storage unit to the third conductive line to the state of supplying the power based on the first power storage unit to the third conductive line, the power based on the first power storage unit can be immediately supplied to the third conductive line via the diode. Therefore, when the power source is switched, the power supply to the common load can be prevented from being interrupted.

[0019] [4] The vehicle-mounted backup control device described in [3] has the following features. It has: a first voltage detection unit that detects the voltage of the first conductive path; and a second voltage detection unit that detects the voltage of the third conductive path. During the priority control, the control unit controls the first conversion unit in a manner that applies a voltage based on the first power storage unit to the first conductive path, controls the second conversion unit in a manner that applies a voltage based on the second power storage unit to the third conductive path, and controls the first conversion unit and the second conversion unit in a manner that maintains the voltage of the third conductive path at a voltage that cuts off the flow of current from the first conductive path to the third conductive path based on the voltage detection results of the first voltage detection unit and the second voltage detection unit.

[0020] In the vehicle-mounted backup control device of [4] above, during the priority control by the control unit, the first conversion unit and the second conversion unit can be controlled based on the voltage detection results of the first voltage detection unit and the second voltage detection unit. Therefore, the voltage applied to the first conductive path based on the power of the first power storage unit and the voltage applied to the second conductive path based on the power of the second power storage unit can be directly controlled.

[0021] [5] The vehicle-mounted backup control device described in [3] has the following features. A current detection unit is provided, and the current detection unit detects the current of the first conductive path. During the priority control, the control unit controls the first conversion unit in such a manner that a voltage based on the first power storage unit is applied to the first conductive path, controls the second conversion unit in such a manner that a voltage based on the second power storage unit is applied to the third conductive path, and controls the first conversion unit and the second conversion unit in such a manner that a current from the first conductive path to the diode side is close to or less than 0 based on the detection result of the current detection unit.

[0022] In the above-mentioned vehicle-mounted backup control device of [5], it is possible to directly detect whether the current flows from the first conductive path to the second conductive path. During the priority control, the control unit controls the first conversion unit in a manner that the voltage based on the first power storage unit is applied to the first conductive path, and controls the second conversion unit in a manner that the voltage based on the second power storage unit is applied to the third conductive path, so that the voltage applied to the first conductive path and the voltage applied to the second conductive path can be controlled to have a desired relationship. By controlling the first conversion unit and the second conversion unit in a manner that the current from the first conductive path to the diode side is close to zero or less, even if the current from the first conductive path to the diode side increases, its increase can be suppressed, and the state of cutting off the flow of current from the first conductive path to the third conductive path is maintained.

[0023] [6] The vehicle-mounted backup control device described in [3] has the following features. The control unit includes a first control unit and a second control unit, the first control unit controls the first supply circuit, and the second control unit controls the second supply circuit. The first control unit and the second control unit are capable of communicating with each other. During the priority control, the first control unit controls the first conversion unit in such a manner that a voltage based on the first power storage unit is applied to the first conductive path, and the second control unit controls the second conversion unit in such a manner that a voltage based on the second power storage unit is applied to the third conductive path. The first control unit and the second control unit control the first conversion unit and the second conversion unit in such a manner that the voltage of the third conductive path is maintained at a voltage that cuts off the flow of current from the first conductive path to the third conductive path.

[0024] In the vehicle-mounted backup control device of the above-mentioned [6], the first control unit and the second control unit can maintain a state in which the flow of current from the first conductive path to the third conductive path is cut off through mutual communication.

[0025] [7] The vehicle-mounted backup control device according to any one of [1] to [6] has the following features. The priority control includes a limiting control that stops the supply of electric power from the second power storage unit to the second load when the second power storage unit is in a specified state. The control unit performs the limiting control according to the specified state until the accumulated operation time of the first load based on the first backup operation reaches a specified time.

[0026] In the vehicle-mounted backup control device of [7] above, the supply of power from the second power storage unit to the second load is stopped (limit control is performed) when the second power storage unit is in a predetermined state, so that the power consumption of the second load after the predetermined state is reached can be suppressed. Therefore, during the period from when the accumulated operation time of the first load based on the first backup operation reaches the predetermined time, the limit control is performed according to the predetermined state, thereby ensuring the power of the second power storage unit for operating the first load.

[0027] [8] The vehicle-mounted backup control device according to [7] has the following feature: the predetermined state is a state in which the open circuit voltage of the second power storage unit is equal to or lower than a cutoff voltage, and the cutoff voltage is set in a predetermined manner.

[0028] In the vehicle-mounted backup control device of [8] above, whether the second power storage unit is in the predetermined state can be determined based on the magnitude of the open circuit voltage of the second power storage unit, so the power storage state of the second power storage unit can be detected with higher accuracy.

[0029] [9] The vehicle-mounted backup control device described in [1] to [8] has the following characteristics: the common load is the second load.

[0030] In the vehicle-mounted backup control device of the above-mentioned [9], the priority of the backup operation to the shared load can be lowered in the backup operation based on the power supply of the second power storage unit. On this basis, the shared load can perform power backup through the backup operation based on the power supply of the first power storage unit. Therefore, the shared load can perform backup based on the power supply of the first power storage unit, and can lower the priority in the backup based on the power supply of the first power storage unit.

[0031] <First embodiment>

[0032] [Structure of the vehicle power supply system]

[0033] Figure 1 The vehicle-mounted power supply system 100 shown includes a power supply unit 90, loads 91, 92, 93, 94, 95, and a vehicle-mounted backup control device 1. The vehicle-mounted backup control device 1 is also referred to as a backup control device 1.

[0034] The power supply unit 90 functions as a main power supply that continuously supplies power when the vehicle equipped with the vehicle power supply system 100 is started. The power supply unit 90 is a DC power supply that generates a DC voltage. The power supply unit 90 is composed of a storage battery such as a lead acid battery, for example. The terminal on the high potential side of the power supply unit 90 is electrically connected to the power line 80, and the terminal on the low potential side of the power supply unit 90 is electrically connected to the ground. The power supply unit 90 applies a predetermined voltage to the power line 80. In addition, in this specification, unless otherwise specified, voltage refers to a voltage with respect to the ground as a reference.

[0035] The power supply unit 90 is electrically connected to the loads 91, 92, 93, 94, and 95 via the power line 80. The power from the power supply unit 90 is supplied to the loads 91, 92, 93, 94, and 95 via the power line 80. Figure 1In the example of , the power line 80 includes: a power line 81A as a conductive line directly connected to the power supply unit 90; a power line 81B connected to the load 91; a power line 81C as a conductive line connected to the load 92; a power line 81D as a conductive line connected to the load 93; a power line 81E as a conductive line connected to the load 94; and a power line 81F as a conductive line connected to the load 95. The power lines 81A, 81B, 81C, 81D, 81E, and 81F are electrically connected to each other. When power is supplied from the power supply unit 90 to the loads 91, 92, 93, 94, and 95, the power lines 81A, 81B, 81C, 81D, 81E, and 81F are at the same potential. The power line 80 is provided with relays, fuses, and the like, which are not shown in the figure, and these elements have the function of cutting off the conduction of the power line 80.

[0036] Loads 91, 92, 93, 94, 95 are vehicle-mounted electrical devices. Loads 91, 92, 93, 94, 95 are loads to which power is expected to be supplied when the power supply from the power supply unit 90 stops in a specified external state (failure state). Loads 91, 92, 93, 94, 95 may be actuators such as motors, for example. Alternatively, they may be ECUs and actuators in electric parking brake systems, ECUs and actuators in shift-by-wire control systems, etc. Alternatively, they may be vehicle-mounted electrical devices other than these.

[0037] Load 93 corresponds to an example of the “predetermined common load” of the present disclosure. Load 93 can be supplied with power from first power storage unit 71 via first supply circuit 31 described later, and can be supplied with power from second power storage unit 72 via second supply circuit 32 described later.

[0038] The backup control device 1 includes a supply circuit 30, a first control unit 41, a second control unit 42, a first detection unit 51, a second detection unit 52, a first power storage unit 71, and a second power storage unit 72. The supply circuit 30 includes a first supply circuit 31 and a second supply circuit 32. The first supply circuit 31 and the second supply circuit 32 may be arranged on the same substrate or on different substrates. The first control unit 41 and the second control unit 42 are equivalent to an example of a “control unit” of the present disclosure. The first power storage unit 71 and the second power storage unit 72 are equivalent to an example of a “power storage unit” of the present disclosure. The backup control device 1 is a device that can perform a backup operation in a predetermined external state in which the supply of power from the power supply unit 90 to the loads 91, 92, 93, 94, 95 is cut off or reduced, and the backup operation supplies power to the loads 91, 92, 93, 94, 95 based on the power of the first power storage unit 71 and the second power storage unit 72.

[0039] The backup control device 1 includes a first power storage unit (basic side unit) 101 and a second power storage unit (expansion side unit) 102. The first power storage unit 101 includes a first power storage unit 71, a first control unit 41 described later, a first supply circuit 31, and a first detection unit 51. The second power storage unit 102 includes a second power storage unit 72, a second control unit 42 described later, a second supply circuit 32, and a second detection unit 52.

[0040] The first power storage unit 71 and the second power storage unit 72 function as auxiliary power supplies. The first power storage unit 71 and the second power storage unit 72 are DC power supplies that output DC voltage, such as double-layer capacitors. The first power storage unit 71 is electrically connected to the first supply circuit 31 described later via the conductive line 15, and is charged and discharged via the first supply circuit 31. The charging voltage (output voltage) of the first power storage unit 71 is the voltage applied to the conductive line 15. The terminal on the high potential side of the first power storage unit 71 is electrically connected to the conductive line 15 and is set to the same potential as the conductive line 15. The terminal on the low potential side of the first power storage unit 71 is electrically connected to the ground and is set to the same potential as the ground.

[0041] The second power storage unit 72 is electrically connected to the second supply circuit 32 described later via the conductive line 25, and is charged and discharged via the second supply circuit 32. The charging voltage (output voltage) of the second power storage unit 72 is the voltage applied to the conductive line 25. The terminal on the high potential side of the second power storage unit 72 is electrically connected to the conductive line 25 and is set to the same potential as the conductive line 25. The terminal on the low potential side of the second power storage unit 72 is electrically connected to the ground and is set to the same potential as the ground.

[0042] In the backup control device 1, in the stop state where the start switch of the vehicle equipped with the vehicle power supply system 100 is turned off, the charging voltage (output voltage) of the first power storage unit 71 and the second power storage unit 72 is maintained at a standby voltage or less. Then, in response to the start switch of the vehicle being turned on, the backup control device 1 charges the first power storage unit 71 and the second power storage unit 72 so that the charging voltage is greater than the target voltage greater than the standby voltage. When the start switch of the vehicle is turned on, the charging voltage of the first power storage unit 71 and the second power storage unit 72 is maintained at the target voltage if no failure state occurs. When the start switch of the vehicle is turned off from the on state, the backup control device 1 discharges the first power storage unit 71 and the second power storage unit 72 until the charging voltage of the first power storage unit 71 and the second power storage unit 72 becomes less than the standby voltage.

[0043] The first supply circuit 31 functions to supply electric power from the first power storage unit 71 to the loads 91 and 92 and the second supply circuit 32. The second supply circuit 32 functions to supply electric power to the loads 94 and 95.

[0044] The first supply circuit 31 outputs the power based on the first power storage unit 71 to the second supply circuit 32. The first supply circuit 31 operates based on the control of the first control unit 41 described later. The first supply circuit 31 is arranged between the conductive line 14 and the conductive lines 11, 12, and 13. The first supply circuit 31 has a voltage conversion circuit such as a DCDC converter. The voltage conversion circuit performs a charging operation and a discharging operation for the first power storage unit 71. As a charging operation, the voltage conversion circuit performs a voltage conversion operation of stepping up or down the voltage applied to the conductive line 14 and applying it to the conductive line 15. As a discharging operation, the voltage conversion circuit performs a voltage conversion operation of stepping up or down the voltage applied to the conductive line 15 and applying it to the conductive line 11, etc.

[0045] The second supply circuit 32 switches between a state in which power based on the input from the first supply circuit 31 is supplied to the load 93 and a state in which power based on the second power storage unit 72 is supplied to the load 93. The second supply circuit 32 operates based on the control of the second control unit 42 described later. The second supply circuit 32 is arranged between the conductive line 24 and the conductive lines 21, 22, and 23. The second supply circuit 32 has, for example, a voltage conversion circuit such as a DCDC converter. The voltage conversion circuit performs a charging operation and a discharging operation for the second power storage unit 72. As a charging operation, the voltage conversion circuit performs a voltage conversion operation to step up or step down the voltage applied to the conductive line 24 and apply it to the conductive line 25. When the voltage conversion circuit supplies power based on the second power storage unit 72 to the load 93, as a discharging operation, the voltage conversion circuit performs a voltage conversion operation to step up or step down the voltage applied to the conductive line 25 and apply it to the conductive line 21, etc.

[0046] The first control unit 41 controls the operation of supplying power from the first power storage unit 71 to the load 91, the load 92, and the second supply circuit 32. The first control unit 41 is an information processing device having information processing functions, calculation functions, control functions, and the like. The first control unit 41 is mainly composed of, for example, a microcomputer, and has a calculation device such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), an A / D converter, and the like. The first control unit 41 has a function of controlling the first supply circuit 31.

[0047] The second control unit 42 controls the operation of supplying power from the second power storage unit 72 to the loads 93, 94, and 95. The second control unit 42 is an information processing device having information processing functions, calculation functions, control functions, and the like. The second control unit 42 is mainly composed of, for example, a microcomputer, and has a calculation device such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), an A / D converter, and the like. The second control unit 42 has a function of controlling the second supply circuit 32.

[0048] The first detector 51 is configured as a voltage detection circuit, for example. The first detector 51 detects the voltage of the conductive line 14. The conductive line 14 is electrically connected to the power line 80 and is set to the same potential as the power line 80. Therefore, the first detector 51 can detect the voltage of the power line 80.

[0049] The conductive line 11 is a conductive line between the first supply circuit 31 and the load 91. The conductive line 12 is a conductive line between the first supply circuit 31 and the load 92. The conductive line 13 is a conductive line between the first supply circuit 31 and the second supply circuit 32.

[0050] The second detector 52 is configured as a voltage detection circuit, for example. The second detector 52 detects the voltage of the conductive line 24. The conductive line 24 is electrically connected to the power line 80 and is set to the same potential as the power line 80. Therefore, the second detector 52 can detect the voltage of the power line 80.

[0051] The conductive line 21 is a conductive line between the second supply circuit 32 and the load 93. The conductive line 22 is a conductive line between the second supply circuit 32 and the load 94. The conductive line 23 is a conductive line between the second supply circuit 32 and the load 95.

[0052] [Detailed structure of backup control device]

[0053] exist Figure 2 An example of the detailed structure of the backup control device 1 is shown in FIG. The first supply circuit 31 can output the power based on the first power storage unit 71 to the load 93 via the first conductive line 111. The first conductive line 111 is a conductive line between the diode 111A and the switch element 33. The anode of the diode 111A is electrically connected to the power line 80. The cathode of the diode 111A is electrically connected to one end of the first conductive line 111. The other end of the first conductive line 111 is electrically connected to the source of the switch element 33.

[0054] The first supply circuit 31 includes a first conversion unit 31A, a switch element 31B, and a first drive unit 31C. The first conversion unit 31A is configured as, for example, a DCDC converter. The first conversion unit 31A is electrically connected to the first conductive path 111. The first conversion unit 31A performs a charging operation and a discharging operation for the first power storage unit 71 based on the control of the first control unit 41. As a charging operation, the first conversion unit 31A performs a voltage conversion operation of stepping up or down an output voltage from the first power storage unit 71 and applying it to the first conductive path 111. As a discharging operation, the first conversion unit 31A steps up or down an input voltage based on the power from the first power storage unit 71 and applies an output voltage to the first conductive path 111. The switch element 31B is configured as, for example, an N-channel MOSFET. The drain of the switch element 31B is electrically connected to the conductive part 111C. The conductive part 111C is a conductive path that constitutes a portion of the first conductive path 111 on the power supply unit 90 side. The source of the switch element 31B is electrically connected to the conductive part 111D. The conductive portion 111D is a conductive path constituting a portion of the first conductive path 111 on the third conductive path 113 side. The first drive unit 31C is a drive circuit that drives the switch element 31B. The first drive unit 31C outputs a control signal to the gate of the switch element 31B.

[0055] The second supply circuit 32 can output the power from the second power storage unit 72 to the load 93 via the second conductive path 112. The second conductive path 112 is a conductive path between the diode 112A and the switch element 33. The anode of the diode 112A is electrically connected to the power line 80. The cathode of the diode 112A is electrically connected to the second conductive path 112.

[0056] The second supply circuit 32 supplies the power from the second power storage unit 72 to one or more loads (for example, loads 94 and 95) and one or more loads (for example, load 93). The loads 94 and 95 correspond to the "first load" of the present disclosure. The load 93 corresponds to the "second load" of the present disclosure.

[0057] The second supply circuit 32 includes a second conversion unit 32A, a switch element 32B, a switch element 32C, and a second drive unit 32D. The second conversion unit 32A is configured as a DCDC converter, for example. The second conversion unit 32A is electrically connected to the second conductive line 112. The second conversion unit 32A performs a charging operation and a discharging operation for the second power storage unit 72 based on the control of the second control unit 42. As a charging operation, the second conversion unit 32A performs a voltage conversion operation of stepping up or down the output voltage of the second power storage unit 72 and applying it to the second conductive line 112. As a discharging operation, the second conversion unit 32A steps up or down the input voltage based on the power from the second power storage unit 72 and applies the output voltage to the second conductive line 112. The switch element 32B is configured as an N-channel MOSFET, for example. The drain of the switch element 32B is electrically connected to the conductive part 112C. The conductive part 112C is a conductive line that constitutes the part of the power supply unit 90 side of the second conductive line 112. The source of the switch element 32B is electrically connected to the conductive portion 112D. The conductive portion 112D is a conductive path that constitutes a portion of the second conductive path 112 on the third conductive path 113 side. The switch element 32C is configured as, for example, an N-channel MOSFET. The source of the switch element 32C is electrically connected to the conductive portion 112D. The drain of the switch element 32C is electrically connected to the third conductive path 113 described later. The second drive unit 32D is a drive circuit that drives the switch element 32B. The second drive unit 32D outputs a control signal to the gate of the switch element 32B.

[0058] The backup control device 1 (more specifically, the second power storage unit 102) further includes a switch element 33, a first voltage detection unit 34, and a second voltage detection unit 35. The switch element 33 is configured as, for example, an N-channel MOSFET. The source of the switch element 33 is electrically connected to the first conductive line 111. The drain of the switch element 33 is electrically connected to the third conductive line 113. The diode 33A is a body diode (parasitic diode) of the switch element 33. The diode 33A is provided between the first conductive line 111 and the third conductive line 113. The anode of the diode 33A is electrically connected to the first conductive line 111 side. The cathode of the diode 33A is electrically connected to the third conductive line 113 side. The diode 33A (more specifically, the switch element 33) may be mounted on a substrate provided with the first supply circuit 31, may be mounted on a substrate provided with the second supply circuit 32, or may be provided outside the substrate provided with the first supply circuit 31 and the substrate provided with the second supply circuit 32.

[0059] The third conductive path 113 is a path for outputting electric power to the load 93. The third conductive path 113 is a path for supplying electric power from the first conductive path 111 and the second conductive path 112. The third conductive path 113 is electrically connected to the load 93.

[0060] The first voltage detection unit 34 is configured as a voltage detection circuit, for example. The first voltage detection unit 34 detects the voltage of the first conductive path 111 (more specifically, the conductive portion 111D). The first voltage detection unit 34 can detect a value based on the output voltage from the first conversion unit 31A.

[0061] The second voltage detection unit 35 is configured as a voltage detection circuit, for example. The second voltage detection unit 35 detects the voltage of the third conductive path 113. The second voltage detection unit 35 can detect a value based on the output voltage from the first conversion unit 31A or a value based on the output voltage from the second conversion unit 32A.

[0062] [Operation of the backup control device]

[0063] exist Figure 3 An example of backup control performed by the backup control device 1 (specifically, the first control unit 41 and the second control unit 42) is shown in FIG. Figure 2 Backup control of . Start Figure 2 The condition of the backup control may be, for example, the case where the start switch of the vehicle equipped with the vehicle power supply system 100 is switched from the off state to the on state, or other conditions. In the representative example described below, when the start switch of the vehicle is switched from the off state to the on state, a start signal indicating that the start switch is switched to the on state is given from an external device (for example, an external ECU (Electronic Control Unit)) to the first control unit 41 and the second control unit 42. When the first control unit 41 and the second control unit 42 receive such a start signal, they start Figure 2 Backup control.

[0064] The first control unit 41 and the second control unit 42 start Figure 2 In the case of standby control, the first power storage unit 71 and the second power storage unit 72 are charged in step S11 so that the charging voltage is equal to or higher than the target voltage greater than the standby voltage. The first control unit 41 and the second control unit 42 maintain the charging voltage of the first power storage unit 71 and the second power storage unit 72 at the target voltage.

[0065] From the start of the standby control until a predetermined decrease in the output voltage of the power supply unit 90 described later is detected (before the determination of "yes" in step S12), the standby standby state is entered. In the standby standby state, the first control unit 41 and the second control unit 42 control the output voltage of the second conversion unit 32A to be greater than the output voltage of the first conversion unit 31A. In the standby standby state, the switch element 31B is turned on by the control of the first control unit 41. The switch element 32B is turned on, the switch element 32C is turned off, and the switch element 33 is turned off by the control of the second control unit 42.

[0066] The first control unit 41 and the second control unit 42 determine in step S12 whether the output voltage of the power supply unit 90 (main power supply) is reduced (in a prescribed reduced state). The first control unit 41 determines whether the voltage of the conductive line 14 is less than a threshold value (in a prescribed reduced state) based on the voltage detected by the first detection unit 51, for example. The threshold value is a value significantly smaller than the output voltage applied to the power line 80 by the power supply unit 90 in normal conditions, and is a value greater than 0. In addition, the second control unit 42 may also determine whether the voltage of the conductive line 24 is less than a threshold value (in a prescribed reduced state) based on the voltage detected by the second detection unit 52. When the first control unit 41 determines in step S12 that the voltage of the conductive line 14 is less than the threshold value (in a prescribed reduced state) (in the case of "yes" in step S12), the process proceeds to step S13. In this representative example, the case where the voltage of the conductive line 14 is less than the threshold value, that is, the case where the voltage of the power line 80 is less than the threshold value corresponds to an example of a "predetermined external state". When the first control unit 41 determines in step S12 that the voltage of the conductive path 14 is equal to or higher than the threshold value (“NO” in step S12 ), the process of step S11 is performed again.

[0067] For example, in an abnormal state where the power supply from the power supply unit 90 to the conductive lines 14 and 24 and the power supply to the power lines 81B, 81C, 81D, 81E, and 81F are interrupted due to a ground fault or disconnection of the power line 80, the voltage of the conductive lines 14 and 24 becomes approximately 0 V. In such a case, in the backup control device 1, the first control unit 41 and the second control unit 42 perform a backup operation in which power is supplied to the plurality of loads 91, 92, 93, 94, and 95 based on the power from the first power storage unit 71 and the second power storage unit 72. The second control unit 42 performs the processing after step S13 on the loads 93, 94, and 95. In addition, the description of the backup operation of the first control unit 41 on the loads 91 and 92 is omitted below, and an example in which power is supplied to the loads 93, 94, and 95 by the second control unit 42 is described.

[0068] When the second control unit 42 determines in step S12 that the voltage of the conductive path 14 is less than the threshold value (in the case of "yes" in step S12), in step S13, power is started to be supplied to the loads 93, 94, and 95. The second control unit 42 causes the second supply circuit 32 to supply power to the conductive paths 21, 22, and 23. When the standby operation (step S13) starts, the switch element 31B is maintained in the on state. Thus, power can be supplied from the first conversion unit 31A to the anode of the diode 33B. The switch element 32B is maintained in the on state. Thus, power can be supplied from the second conversion unit 32A to the third conductive path 113 side. In addition, the switch element 32C is maintained in the off state, and the switch element 33 is maintained in the off state.

[0069] In the next step S14, the second control unit 42 performs power supply control for the load 93. In the power supply control for the load 93, Figure 4 As shown, the second control unit 42 first determines whether the open circuit voltage (OCV) of the second power storage unit 72 is equal to or lower than the cutoff voltage (step S21). The open circuit voltage Vocv of the second power storage unit 72 can be calculated using the following relational expression (1), for example.

[0070] Vocv=Vccv-I×R(1)

[0071] Vccv is a closed circuit voltage, which is an output voltage output from the second power storage unit 72. I is a current flowing through the second power storage unit 72. R is an internal resistance.

[0072] The cut-off voltage is a voltage threshold value set in a predetermined manner. For example, the cut-off voltage may be determined by using an operation cumulative time t as a variable and setting an operation formula in such a way that the cut-off voltage is lowered as t increases. The cut-off voltage may also be determined by setting an operation formula for the cut-off voltage based on the power consumption of the loads 94 and 95 from the start of the standby operation. Figure 6 As shown, the cutoff voltage (load 93 cutoff voltage) may be determined as a voltage equivalent to the operating energy of loads 94 and 95 (the energy that loads 94 and 95 can operate in the remaining time). Alternatively, the cutoff voltage may be determined as a fixed value.

[0073] When the second control unit 42 determines in step S21 that the open circuit voltage of the second power storage unit 72 is not less than the cutoff voltage (greater than the cutoff voltage) ("No" in step S21), the second supply circuit 32 is used for supply control. The second control unit 42 controls the second supply circuit 32 so that the power based on the second power storage unit 72 is output to the load 93 via the second conductive path 112. Here, the first control unit 41 and the second control unit 42 control the first conversion unit 31A and the second conversion unit 32A based on the voltage detection results generated by the first voltage detection unit 34 and the second voltage detection unit 35 so as to maintain the voltage of the third conductive path 113 at a voltage that cuts off the flow of current from the first conductive path 111 to the third conductive path 113. For example, the voltage of the cathode of the diode 33A (the voltage of the third conductive path 113) is controlled to be greater than the voltage of the anode of the diode 33A (the voltage of the first conductive path 111). In addition, the switch element 31B is maintained in the on state. The switch element 32B is maintained in the on operation. Then, the switch element 32C performs the on operation under the control of the second control unit 42. The switch element 33 maintains the off operation.

[0074] On the other hand, when the first control unit 41 and the second control unit 42 determine in step S21 that the open-circuit voltage of the second power storage unit 72 is below the cut-off voltage ("Yes" in step S21), the supply control based on the second supply circuit 32 is stopped, and the supply control based on the first supply circuit 31 is performed. The first control unit 41 stops supplying the power based on the second power storage unit 72 to the load 93. The second control unit 42 controls the second supply circuit 32 to output the power based on the second power storage unit 72 to the load 93 via the second conductive path 112. Specifically, the switch element 31B maintains the on action. Through the control of the second control unit 42, the switch element 32B performs the off action, the switch element 32C performs the off action, and the switch element 33 performs the on action. After the processing of steps S21 and S22, the first control unit 41 and the second control unit 42 perform Figure 3 Step S15.

[0075] In the next step S15, the first control unit 41 and the second control unit 42 perform power supply control for the loads 94 and 95. In the power supply control for the loads 94 and 95, as shown in FIG. Figure 5 As shown, the second control unit 42 first determines whether the specified time of the load 94, 95 has passed (step S31). The specified time is, for example, a time pre-set in order to make the load 94, 95 continuously operate. The specified time is set, for example, based on the power consumption of one operation of the load 94, 95, the number of predetermined operations, etc. In addition, within the specified time, making the load 94, 95 continuously operate also includes that the load 94, 95 continuously operates without interruption or operates intermittently. For example, Figure 7 As shown, the predetermined time is the time from the start time of the backup operation to the time when the operating energy of the loads 94 and 95 (the energy that can operate the loads 94 and 95 in the remaining time) falls below a predetermined lower limit voltage.

[0076] When the first control unit 41 and the second control unit 42 determine in step S31 that the predetermined time of the loads 94 and 95 has elapsed, in the next step S32, the power supply to the loads 94 and 95 is stopped. Figure 3 On the other hand, if the first control unit 41 and the second control unit 42 determine in step S31 that the predetermined time of the loads 94 and 95 has not elapsed, Figure 3 Step S16 is shown.

[0077] The first control unit 41 and the second control unit 42 perform a predetermined priority control when in the external state through the processing of the above-mentioned steps S14 and S15, and the predetermined priority control gives priority to the first backup action over the second backup action. The first backup action is an action of supplying the power based on the second power storage unit 72 to the loads 94 and 95. The second backup action is an action of supplying the power based on the second power storage unit 72 to the load 93. The priority control includes a restriction control (step S23) that stops the supply of the power based on the second power storage unit 72 to the load 93 when the second power storage unit 72 becomes a predetermined state. The first control unit 41 and the second control unit 42 perform the restriction control (step S23) according to the predetermined state until the cumulative operation time of the loads 94 and 95 based on the first backup action reaches the predetermined time (until it becomes "Yes" in step S31).

[0078] The first control unit 41 and the second control unit 42 control the output of the first conversion unit 31A to the first conductive path 111 and the output of the second conversion unit 32A to the second conductive path 112 in a priority control so that the power based on the second power storage unit 72 is supplied to the third conductive path 113 via the second conductive path 112 and the power based on the first power storage unit 71 is cut off by the diode 33A. Specifically, the first control unit 41 and the second control unit 42 control the first conversion unit 31A in a priority control so that the voltage based on the first power storage unit 71 is applied to the first conductive path 111, and control the second conversion unit 32A in a priority control so that the voltage based on the second power storage unit 72 is applied to the third conductive path 113. Furthermore, the first control unit 41 and the second control unit 42 control the first conversion unit 31A and the second conversion unit 32A based on the voltage detection results generated by the first voltage detection unit 34 and the second voltage detection unit 35 so as to maintain the voltage of the third conductive path 113 at a voltage that cuts off the flow of current from the first conductive path 111 to the third conductive path 113. For example, the voltage of the cathode of the diode 33A (the voltage of the third conductive path 113) is controlled to be greater than the voltage of the anode of the diode 33A (the voltage of the first conductive path 111). Thus, only the second power storage unit 72 is selectively supplied to the load 93. When switching from the state of supplying the power based on the second power storage unit 72 to the third conductive path 113 to the state of supplying the power based on the first power storage unit 71 to the third conductive path 113, the power based on the first power storage unit 71 can be immediately supplied to the third conductive path 113 via the diode 33A. Therefore, when switching the power source, it is possible to prevent the power supply to the load 93 from being interrupted.

[0079] After the first control unit 41 and the second control unit 42 have performed power supply control for the loads 94 and 95 (step S15), in the next step S16, it is determined whether the vehicle equipped with the vehicle power supply system 100 is in a stopped state. The first control unit 41 and the second control unit 42 determine whether the start switch of the vehicle equipped with the vehicle power supply system 100 has been switched from the on state to the off state. For example, when the start switch of the vehicle is changed from the on state to the off state, a start signal indicating that the start switch has been switched to the off state is given to the first control unit 41 and the second control unit 42 from an external device (for example, an external ECU (Electronic Control Unit)). When receiving such a start signal, the first control unit 41 and the second control unit 42 determine that the vehicle is in a stopped state. When the first control unit 41 and the second control unit 42 determine that the vehicle is not in a stopped state (is in a started state) in step S16 (in the case of "No" in step S16), the process of step S14 is performed again. If the first control unit 41 and the second control unit 42 determine that the vehicle is in a stopped state in step S16 (if "YES" in step S16), the process ends. Figure 2 Backup control.

[0080] The following description relates to an example of the effect of this configuration.

[0081] The backup control device 1 can perform a backup operation using the first power storage unit 71 and the second power storage unit 72 in an external state where the supply of power from the power supply unit 90 is cut off or reduced. In the backup control device 1, power can be supplied from the first power storage unit 71 and the second power storage unit 72 to a predetermined common load (load 93). Therefore, the backup control device 1 can use both the operation of supplying power from the first power storage unit 71 and the operation of supplying power from the second power storage unit 72 to the common load during the backup operation. On this basis, the first backup operation (operation of supplying power based on the second power storage unit 72 to the loads 94 and 95) can be prioritized over the second backup operation (operation of supplying power based on the second power storage unit 72 to the load 93) through a predetermined priority control performed by the first control unit 41 and the second control unit 42.

[0082] Furthermore, in the backup control device 1, when the second power storage unit 72 is in a predetermined state, the supply of power to the load by the second power storage unit 72 is stopped (limit control is performed), so that the power consumption by the loads 94 and 95 after the predetermined state is reached can be suppressed. Therefore, during the period until the cumulative operation time of the loads 94 and 95 based on the first backup operation reaches the predetermined time, the limit control is performed according to the predetermined state, thereby ensuring the power of the second power storage unit 72 for operating the loads 94 and 95.

[0083] Furthermore, in backup control device 1, whether or not second power storage unit 72 is in a predetermined state can be determined based on the magnitude of the open circuit voltage of second power storage unit 72, so the power storage state of second power storage unit 72 can be detected with higher accuracy.

[0084] In the backup control device 1, during the priority control by the first control unit 41 and the second control unit 42, the power from the second power storage unit 72 can be supplied to the third conductive path 113 via the second conductive path 112. In the state where the output voltage is applied to the first conductive path 111 by the first conversion unit 31A, the power from the first power storage unit 71 is cut off by the diode 33A, so that the backup preparation state for the common load (load 93) can be set in a form in which the power consumption of the first power storage unit 71 is suppressed. When switching from the state in which the power from the second power storage unit 72 is supplied to the third conductive path 113 to the state in which the power from the first power storage unit 71 is supplied to the third conductive path 113, the power from the first power storage unit 71 can be immediately supplied to the third conductive path 113 via the diode 33A. Therefore, when the power source is switched, the power supply to the common load (load 93) can be prevented from being interrupted.

[0085] In the backup control device 1, during the priority control by the first control unit 41 and the second control unit 42, the first conversion unit 31A and the second conversion unit 32A can be controlled based on the voltage detection results by the first voltage detection unit 34 and the second voltage detection unit 35. Therefore, the voltage applied to the first conductive path 111 based on the power of the first power storage unit 71 and the voltage applied to the second conductive path 112 based on the power of the second power storage unit 72 can be directly controlled.

[0086] In the backup control device 1, in the backup operation by the power supply by the second power storage unit 72, the priority of the backup operation to the common load (load 93) can be lowered. On this basis, the common load (load 93) can perform the backup operation by the power supply by the first power storage unit 71. Therefore, the common load (load 93) can perform the backup by the power supply by the first power storage unit 71, and can lower the priority in the backup by the power supply by the first power storage unit 71.

[0087] <Second embodiment>

[0088] The vehicle-mounted power supply system 200 of the second embodiment is different from the first embodiment in that a current detector 234 is provided instead of the first voltage detector 34 and the second voltage detector 35, but is the same in other aspects. The same reference numerals are used for the same structures as those of the first embodiment, and detailed descriptions thereof are omitted.

[0089] In the vehicle-mounted power supply system 200, as Figure 8 As shown, the second power storage unit 102 includes a current detection unit 234. The current detection unit 234 is configured as a current detection circuit. The current detection unit 234 detects the current of the first conductive path 111 (more specifically, the conductive portion 111D).

[0090] The backup control of the backup control device 1 is the same as that of the first embodiment, but the specific control contents shown below are different from those of the first embodiment. In the case of priority control, the first control unit 41 and the second control unit 42 control the first conversion unit 31A so that the voltage based on the first power storage unit 71 is applied to the first conductive path 111, and control the second conversion unit 32A so that the voltage based on the second power storage unit 72 is applied to the third conductive path 113. In the case of priority control, the control unit further controls the first conversion unit 31A and the second conversion unit 32A so that the current from the first conductive path 111 to the diode 33A side is close to zero or less based on the detection result of the current detection unit 234. For example, the voltage of the cathode of the diode 33A (the voltage of the third conductive path 113) is controlled to be a value greater than the voltage of the anode of the diode 33A (the voltage of the first conductive path 111). As a result, only the second power storage unit 72 selectively supplies power to the load 93.

[0091] In the backup control device 1, it is possible to directly detect whether or not the current flows from the first conductive path 111 to the second conductive path 112. In the case of priority control, the first control unit 41 and the second control unit 42 control the first conversion unit 31A so that the voltage based on the first power storage unit 71 is applied to the first conductive path 111, and control the second conversion unit 32A so that the voltage based on the second power storage unit 72 is applied to the third conductive path 113, so that the voltage applied to the first conductive path 111 and the voltage applied to the second conductive path 112 can be controlled to have a desired relationship. By controlling the first conversion unit 31A and the second conversion unit 32A so that the current from the first conductive path 111 to the diode 33A side is close to zero or less, even if the current from the first conductive path 111 to the diode 33A side increases, the increase can be suppressed, and the state of cutting off the flow of the current from the first conductive path 111 to the third conductive path 113 can be maintained. When switching the power source, it is possible to prevent the power supply to the common load (load 93) from being interrupted.

[0092] <Third Embodiment>

[0093] The vehicle-mounted power supply system 300 of the third embodiment is different from the first embodiment in that the first control unit 41 and the second control unit 42 can communicate with each other, but is the same in other aspects. The same reference numerals are used for the same structures as those of the first embodiment, and detailed descriptions thereof are omitted.

[0094] In the vehicle power system, such as Fig. 9 As shown, the backup control device 1 includes a first control unit 41 and a second control unit 42. The first control unit 41 and the second control unit 42 can communicate with each other. For example, the communication between the first control unit 41 and the second control unit 42 is CAN (Control Area Network) communication, LIN (Local Interconnect Network) communication, etc., and the communication method is not limited.

[0095] The backup control of the backup control device 1 is similar to the first embodiment ( Figure 3 to Figure 5 ), the following mainly describes the control contents (priority control) that are different from the first embodiment. First, similarly to the first embodiment, in the standby state, the first control unit 41 and the second control unit 42 control the second conversion unit 32A to be greater than the output voltage of the first conversion unit 31A. In the standby state, the switch element 31B is turned on by the control of the first control unit 41. The switch element 32B is turned on, the switch element 32C is turned off, and the switch element 33 is turned off by the control of the second control unit 42.

[0096] In the backup control of the backup control device 1 ( Figure 3 to Figure 5 ), when the backup operation (step S13) is started, the switch element 31B is maintained in the on state. The switch element 32B is maintained in the on state. Furthermore, the switch element 32C is maintained in the off state, and the switch element 33 is maintained in the off state.

[0097] In the priority control, the first control unit 41 controls the first conversion unit 31A so that the voltage based on the first power storage unit 71 is applied to the first conductive path 111, and the second control unit 42 controls the second conversion unit 32A so that the voltage based on the second power storage unit 72 is applied to the third conductive path 113. In addition, the first control unit 41 and the second control unit 42 control the first conversion unit 31A and the second conversion unit 32A so that the voltage of the third conductive path 113 is maintained at a voltage that cuts off the flow of current from the first conductive path 111 to the third conductive path 113. For example, the voltage of the cathode of the diode 33A (the voltage of the third conductive path 113) is controlled to be greater than the voltage of the anode of the diode 33A (the voltage of the first conductive path 111). In addition, the switch element 31B and the switch element 32B are maintained in the on operation. In addition, the switch element 32C is turned on by the control of the second control unit 42. The switch element 33 is maintained in the off operation. Thus, only the second power storage unit 72 selectively supplies power to the load 93. In this way, the mutual communication between the first control unit 41 and the second control unit 42 can maintain a state in which the flow of current from the first conductive path 111 to the third conductive path 113 is blocked.

[0098] When it is determined that the open circuit voltage of the second power storage unit 72 is below the cutoff voltage ("Yes" in step S21), the supply control based on the second supply circuit 32 is stopped, and the supply control based on the first supply circuit 31 is performed. Specifically, the switch element 31B maintains the on operation. Under the control of the second control unit 42, the switch element 32B performs the off operation, the switch element 32C performs the off operation, and the switch element 33 performs the on operation. When switching the power source, it is possible to prevent the power supply to the common load (load 93) from being interrupted.

[0099] <Fourth embodiment>

[0100] The vehicle-mounted power supply system of the fourth embodiment has the same structure as the vehicle-mounted power supply system of the third embodiment, and is different from the third embodiment in a part of the backup control of the backup control device 1, but is common in other aspects. In addition, the same reference numerals are given to the same structures as the third embodiment, and detailed descriptions are omitted.

[0101] In the backup control device 1 , similarly to the third embodiment, the first control unit 41 and the second control unit 42 are capable of communicating with each other.

[0102] In the backup control of the backup control device 1 ( Figure 3 to Figure 5), the following mainly describes the control (priority control) that is different from the third embodiment. First, similarly to the third embodiment, in the standby state, the first control unit 41 and the second control unit 42 control the second conversion unit 32A to be greater than the output voltage of the first conversion unit 31A. In the standby state, the switch element 31B is turned on by the control of the first control unit 41. The switch element 32B is turned on, the switch element 32C is turned off, and the switch element 33 is turned off by the control of the second control unit 42.

[0103] The backup operation is started (step S13), and the switch element 31B is turned off by the control of the first control unit 41. As a result, the energization from the first conversion unit 31A to the anode of the diode 33B is cut off. The switch element 32B is maintained in the on state. As a result, the energization from the second conversion unit 32A to the third conductive path 113 side can be performed. In addition, the switch element 32C is maintained in the on state, and the switch element 33 is maintained in the off state. In this way, by selectively turning the switch element 32B on, the backup control device 1 applies the voltage based on the second power storage unit 72 to the third conductive path 113 via the second conductive path 112 (step S22).

[0104] When the open circuit voltage of the second power storage unit 72 becomes less than the cut-off voltage ("Yes" in step S21), the first control unit 41 causes the switch element 31B to perform a turn-on operation through mutual communication between the first control unit 41 and the second control unit 42. As a result, the anode of the diode 33B can be energized from the first conversion unit 31A. The switch element 32B maintains the turn-on operation. Moreover, the switch element 32C performs a turn-off operation through the control of the second control unit 42. The switch element 33 maintains the turn-off operation. The larger voltage of the voltage applied to the switch element 32C and the voltage applied to the switch element 32C is applied to the third conductive path 113. During the period of transferring the power source from the second power storage unit 72 to the first power storage unit 71, the current flows to the third conductive path 113 via the diode 33B or the body diode of the switch element 32C.

[0105] When the power source is completely transferred from the second power storage unit 72 to the first power storage unit 71 (step S23), the switch element 31B is turned on by the control of the first control unit 41. As a result, the anode of the diode 33B can be energized from the first conversion unit 31A. The switch element 32B is turned off by the control of the second control unit 42. As a result, the energization from the second conversion unit 32A to the third conductive path 113 is cut off. The switch element 33 is turned on by the control of the second control unit 42. As a result, the third conductive path 113 can be energized from the first conversion unit 31A. In this way, by selectively turning on the switch element 31B, the backup control device 1 applies the voltage based on the first power storage unit 71 to the third conductive path 113 via the first conductive path 111. When switching the power source, it is possible to prevent the power supply to the common load (load 93) from being interrupted.

[0106] <Fifth embodiment>

[0107] The vehicle-mounted power supply system 400 of the fifth embodiment is different from the fourth embodiment in that a switching element 433 is provided instead of the switching element 33, and is the same in other aspects. The same reference numerals are used for the same structures as those of the fourth embodiment, and detailed descriptions thereof are omitted.

[0108] In the vehicle-mounted power supply system 400, as Fig.10 As shown, the backup control device 1 (more specifically, the first power storage unit 101) has a switch element 433. The switch element 433 is provided between the first conductive path 111 and the third conductive path 113. The first conductive path 111 is provided between the diode 111A and the switch element 433. The third conductive path 113 is provided between the switch element 433 and the switch element 32C and the load 93.

[0109] The switch element 433 is configured as, for example, an N-channel MOSFET. The source of the switch element 433 is electrically connected to one end (the end on the load 93 side) of the first conductive line 111. The drain of the switch element 433 is electrically connected to the third conductive line 113. The diode 433A is a body diode (parasitic diode) of the switch element 433. The diode 433A is provided between the first conductive line 111 and the third conductive line 113. The anode of the diode 433A is electrically connected to the first conductive line 111 side. The cathode of the diode 433A is electrically connected to the third conductive line 113 side. The diode 433A (more specifically, the switch element 433) may be mounted on the substrate provided with the first supply circuit 31, may be mounted on the substrate provided with the second supply circuit 32, or may be provided outside the substrate provided with the first supply circuit 31 and the substrate provided with the second supply circuit 32.

[0110] Backup control of backup control device 1 ( Figure 3 to Figure 5 ) is the same as the third embodiment. Specifically, the switch element 433 performs the on-off operation at the same time as the switch element 33 of the third embodiment. That is, the switch element 433 performs the on-operation at the time when the switch element 33 of the third embodiment performs the on-operation, and performs the off-operation at the time when the switch element 33 of the third embodiment performs the off-operation.

[0111] The vehicle-mounted power supply system 400 of the fifth embodiment can achieve the same effects as the vehicle-mounted power supply system of the fourth embodiment. In particular, when the backup operation (step S13) of the backup control device 1 starts, the voltage of the cathode of the diode 33A (the voltage of the third conductive path 113) is controlled to be greater than the voltage of the anode of the diode 33A (the voltage of the first conductive path 111). As a result, power can be selectively supplied to the load 93 only from the second power storage unit 72.

[0112] <Sixth embodiment>

[0113] The vehicle-mounted power supply system 500 of the sixth embodiment has a switching unit 533, which is different from the first embodiment mainly in that the power supplied to the load 93 is switched by the switching unit 533, and is common in other aspects. In addition, the same reference numerals are given to the same structures as the first embodiment, and detailed descriptions are omitted.

[0114] In the vehicle-mounted power supply system 500, as Fig.11 As shown, the supply circuit 530 of the backup control device 1 includes a first supply circuit 31, a second supply circuit 32, and a switching unit 533. The first supply circuit 31 functions to supply power to the switching unit 533. The first supply circuit 31 outputs power based on the first power storage unit 71 to the switching unit 533 via the first conductive path 511. The first conductive path 511 is a conductive path between the first supply circuit 31 and the switching unit 533.

[0115] The second supply circuit 32 functions to supply power to the switch unit 533. The second supply circuit 32 outputs the power based on the second power storage unit 72 to the switch unit 533 via the second conductive path 512. The second conductive path 512 is a conductive path between the second supply circuit 32 and the switch unit 533. The conductive path 534 is a conductive path between the switch unit 533 and the load 93.

[0116] The switching unit 533 switches between a state in which the power based on the output from the first supply circuit 31 is supplied to the load 93 and a state in which the power based on the output from the second supply circuit 32 is supplied to the load 93. The switching unit 533 includes, for example, a switch. The switching unit 533 operates under the control of, for example, the first control unit 41 and the second control unit 42.

[0117] exist Fig.12 An example of the detailed structure of the backup control device 1 is shown in . It is different from the first embodiment in that the first control unit 41 and the second control unit 42 can communicate with each other. For example, the communication between the first control unit 41 and the second control unit 42 is CAN (Control Area Network) communication, LIN (Local Interconnect Network) communication, etc., and the communication method is not limited. The switching unit 533 has a diode 535 and a diode 536. The first conductive line 511 is arranged between the diode 111A and the diode 535. The second conductive line 512 is arranged between the diode 112A and the diode 536. The third conductive line 513 is arranged between the diode 535 and the diode 536 and the load 93.

[0118] The anode of the diode 535 is electrically connected to the other end (the end on the load 93 side) of the first conductive path 511. The cathode of the diode 535 is electrically connected to the cathode of the diode 536 and one end (the end on the power supply unit 90 side) of the third conductive path 513. The anode of the diode 536 is electrically connected to the other end (the end on the load 93 side) of the second conductive path 512. The load 93 is electrically connected to the other end of the third conductive path 513.

[0119] The backup control of the backup control device 1 is similar to the first embodiment ( Figure 3 to Figure 5 ), the following mainly describes the control contents (priority control) that are different from the first embodiment. First, as in the first embodiment, in the standby state, the first control unit 41 and the second control unit 42 control the output voltage of the second conversion unit 32A to be greater than the output voltage of the first conversion unit 31A. In the standby state, the switch element 31B is disconnected by the control of the first control unit 41. The switch element 32B is disconnected by the control of the second control unit 42.

[0120] In the backup control of the backup control device 1 ( Figure 3 to Figure 5 ), when the standby operation (step S13) starts, the switch element 31B is turned on by the control of the first control unit 41. The switch element 32B is turned on by the control of the second control unit 42.

[0121] In the priority control, the first control unit 41 and the second control unit 42 control the second conversion unit 32A to be greater than the output voltage of the first conversion unit 31A. More specifically, the first conversion unit 31A and the second conversion unit 32A are controlled so that the voltage applied to the diode 535 (the voltage of the first conductive path 511) becomes greater than the voltage applied to the diode 536 (the voltage of the second conductive path 512). The switch element 31B and the switch element 32B are maintained in the on state. Thus, only the second power storage unit 72 is selectively supplied to the load 93. In this way, the mutual communication between the first control unit 41 and the second control unit 42 can maintain the state of cutting off the flow of current from the first conductive path 511 to the third conductive path 513.

[0122] When it is determined that the open circuit voltage of the second power storage unit 72 is below the cutoff voltage ("Yes" in step S21), the supply control based on the second supply circuit 32 is stopped, and the supply control based on the first supply circuit 31 is performed. Specifically, the switch element 31B maintains the on operation. The switch element 32B performs the off operation under the control of the second control unit 42. When the power source is switched, the power supply to the common load (load 93) can be prevented from being interrupted.

[0123] <Other embodiments>

[0124] The present disclosure is not limited to the embodiments described in the above description and the accompanying drawings. For example, the features of the above or later embodiments can be combined in all ways within the scope of non-contradiction. In addition, any feature in the above or later embodiments can be omitted as long as it is not explicitly stated as a required feature. Moreover, the above embodiments can also be changed as follows.

[0125] In the first to third embodiments, the diode 33A is configured as a body diode (parasitic diode) of the switching element 33, but may be configured as a general forward diode. The same applies to the diode 433A in the fourth and fifth embodiments.

[0126] In the above embodiment, in the backup control of the backup control device 1, in step S12, as the predetermined external state, the state in which the voltage of the conductive line 14 is less than the threshold value is exemplified, but other states may be used. For example, the predetermined external state may be a state in which there is a request for backup action from the load (specifically, a state in which at least one of the first control unit 41 and the second control unit 42 receives a signal requesting backup action from the load).

[0127] In the above embodiment, during the backup control (priority control) of the backup control device 1, the output voltage of the second conversion unit 32A is made larger than the output voltage of the first conversion unit 31A, but the control of either the first conversion unit 31A or the second conversion unit 32A may be stopped. The "control of the first conversion unit and the second conversion unit" in the present disclosure may also include stopping the operation of either the first conversion unit 31A or the second conversion unit 32A by stopping the control performed by either the first control unit 41 or the second control unit 42.

[0128] In the first to fourth embodiments described above, the load 93 is electrically connected to the second power storage unit 102, but it may be electrically connected to the first power storage unit 101. In this case, the first power storage unit 101 is supplied with power from the second power storage unit 102 and switches the power source for the load 93 (the same structure as the second power storage unit 102 in the first to fourth embodiments described above).

[0129] In the above embodiment, while the operation cumulative time reaches the predetermined time (until the result is “Yes” in step S31 ), the limiting control is performed according to the predetermined state (step S23 ), control may be performed such that power is not supplied to the load 93 until the operation cumulative time reaches the predetermined time.

[0130] In the above-mentioned embodiment, during the period until the accumulated action time reaches the prescribed time (until it becomes "Yes" in step S31), limit control is performed according to the prescribed state (step S23), but priority control such as performing the above-mentioned limit control until a certain time has passed since the occurrence of the external state (or the start of the standby action) may be performed, or control such as not supplying power to the load 93 until a certain time has passed since the occurrence of the external state (or the start of the standby action) may be performed.

[0131] In the above-described embodiment, the operations of the loads 94 and 95 are not restricted, and the load 93 may be preferentially controlled so that the total power consumption is suppressed within a predetermined range.

[0132] In the above embodiment, the start switch of the vehicle is described, but the start switch may be an ignition switch or, in an electric vehicle or the like, may be a power switch for operating the EV system.

[0133] In the above embodiment, the power source is a lead acid battery, but is not limited to a lead acid battery. The power source may be other types of batteries such as a lithium ion battery, or may be a power source such as an AC generator or a converter.

[0134] In the above embodiment, the power storage unit is an electric double layer capacitor, but the power storage unit is not limited to the electric double layer capacitor and may be another type of power storage unit such as a lithium ion capacitor or a lithium ion storage battery.

[0135] In the above embodiment, the backup control device performs the backup operation when the power supply from the power supply unit is interrupted. However, the backup control device may perform the backup operation by supplying power from the power storage unit in a predetermined state where the power supply is not completely interrupted.

[0136] The embodiments disclosed herein are illustrative in all aspects and should not be construed as restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope of the claims or within the scope equivalent to the claims.

[0137] Description of symbols 1: Backup control device 11, 12, 13, 14, 15, 21, 22, 23, 24, 25: Conductive circuits 30: Supply circuit 31: First supply circuit 31A: First conversion unit 31B: Switching element 31C: First drive unit 32: Second supply circuit 32A: Second conversion unit 32B: Switching element 32C: Switching element 32D: Second drive unit 33: Switching element 33A: Diode 33B: Diode 34: First voltage detection unit 35: Second voltage detection unit 41: First control unit (control unit) 42: Second control unit (control unit) 51: First Detection Department 52: Second detection unit 71: First power storage unit 72: Second power storage unit 80: Power lines 81A, 81B, 81C, 81D, 81E, 81F: Power lines 90: Power supply department 91, 92: Load 93: Load (shared load, second load) 94: Load (first load) 95: Load (first load) 100: In-vehicle power supply system 101: First power storage unit (base-side unit) 102: Second power storage unit (expansion side unit) 111: First conductive circuit 111A: Diode 111C: Conductive part 111D: Conductive part 112: Second conductive circuit 112A: Diode 112C: Conductive part 112D: Conductive part 113: The third conductive line 200: In-vehicle power supply system 234: Current detection unit 300: In-vehicle power supply system 400: In-vehicle power system 433: Switching element 433A: Diode 500: In-vehicle power system 511: First conductive circuit 512: Second conductive circuit 513: The third conductive circuit 530: Supply circuit 533: Switching Department 534: Conductive circuit 535: Diode 536: diode.

Claims

1. A vehicle-mounted backup control device, used in a vehicle-mounted power supply system having a power supply unit and a power storage unit, which performs a backup operation of outputting power to the load based on the power from the power storage unit when a predetermined external state occurs in which the power supply from the power supply unit to the load is cut off or reduced, wherein: The vehicle-mounted backup control device comprises: a first supply circuit capable of outputting electric power based on a first power storage unit to a common load via a first conductive path, the first power storage unit being one of the power storage units; a second supply circuit capable of outputting electric power based on a second power storage unit to the common load via a second conductive path, the second power storage unit being one of the power storage units; and a control unit that causes the first supply circuit and the second supply circuit to perform the standby operation when in the external state; The second supply circuit supplies power based on the second power storage unit to one or more first loads and one or more second loads. The control unit performs a prescribed priority control when in the external state, and the prescribed priority control gives priority to a first backup action over a second backup action, wherein the first backup action supplies power to the first load based on the power of the second power storage unit, and the second backup action supplies power to the second load based on the power of the second power storage unit.

2. The vehicle-mounted backup control device according to claim 1, wherein: The vehicle-mounted backup control device has a third conductive path, the third conductive path is a path for outputting power to the common load, and is a path for supplying power from the first conductive path and the second conductive path. The first supply circuit includes a first switch element, which is provided on the first conductive path and can conduct electricity from the first power storage unit to the third conductive path when in an on state, and cut off electricity from the first power storage unit to the third conductive path when in an off state. The second supply circuit includes a second switch element, which is provided in the second conductive path and can conduct electricity from the second power storage unit to the third conductive path when in an on state, and cut off electricity from the second power storage unit to the third conductive path when in an off state. The control unit includes a first control unit and a second control unit, the first control unit controls the first supply circuit, and the second control unit controls the second supply circuit. The first control unit and the second control unit are capable of communicating with each other, During the second backup action, the first control unit sets the first switching element to an off state, and the second control unit sets the second switching element to an on state, so that the voltage based on the second power storage unit is applied to the third conductive path via the second conductive path. During the first backup action, the first control unit sets the first switching element to an on state, and the second control unit sets the second switching element to an off state, so that the voltage based on the first power storage unit is applied to the third conductive path via the first conductive path.

3. The vehicle-mounted backup control device according to claim 1, wherein: The vehicle-mounted backup control device comprises: a third conductive path, the third conductive path being a path for outputting power to the common load and being a path for supplying power from the second conductive path; and a diode, disposed between the first conductive circuit and the third conductive circuit, wherein an anode of the diode is electrically connected to a side of the first conductive circuit, and a cathode of the diode is electrically connected to a side of the third conductive circuit, The first supply circuit includes a first conversion unit that steps up or steps down an input voltage based on the power from the first power storage unit and applies an output voltage to the first conductive path. The second supply circuit includes a second conversion unit that steps up or steps down an input voltage based on the power from the second power storage unit and applies an output voltage to the second conductive path. During the priority control, the control unit controls the output of the first conversion unit to the first conductive path and the output of the second conversion unit to the second conductive path in such a manner that the power based on the second power storage unit is supplied to the third conductive path via the second conductive path and the power based on the first power storage unit is cut off by the diode.

4. The vehicle-mounted backup control device according to claim 3, wherein: The vehicle-mounted backup control device comprises: A first voltage detection unit, detecting a voltage of the first conductive circuit; and a second voltage detection unit, detecting a voltage of the third conductive line; During the priority control, the control unit controls the first conversion unit in such a manner that a voltage based on the first power storage unit is applied to the first conductive path, controls the second conversion unit in such a manner that a voltage based on the second power storage unit is applied to the third conductive path, and controls the first conversion unit and the second conversion unit in such a manner that a voltage based on the second power storage unit is applied to the third conductive path, and based on the voltage detection results of the first voltage detection unit and the second voltage detection unit, controls the first conversion unit and the second conversion unit in such a manner that a voltage of the third conductive path is maintained at a voltage that cuts off a flow of current from the first conductive path to the third conductive path.

5. The vehicle-mounted backup control device according to claim 3, wherein: The vehicle-mounted backup control device includes a current detection unit, which detects the current of the first conductive path. During the priority control, the control unit controls the first conversion unit in such a manner that a voltage based on the first power storage unit is applied to the first conductive path, controls the second conversion unit in such a manner that a voltage based on the second power storage unit is applied to the third conductive path, and controls the first conversion unit and the second conversion unit based on the detection result of the current detection unit so that the current from the first conductive path toward the diode side is close to or less than 0.

6. The vehicle-mounted backup control device according to claim 3, wherein: The control unit includes a first control unit and a second control unit, wherein the first control unit controls the first supply circuit and the second control unit controls the second supply circuit. The first control unit and the second control unit are capable of communicating with each other, During the priority control, the first control unit controls the first conversion unit in such a manner that a voltage based on the first power storage unit is applied to the first conductive path, and the second control unit controls the second conversion unit in such a manner that a voltage based on the second power storage unit is applied to the third conductive path. The first control unit and the second control unit control the first conversion unit and the second conversion unit in such a manner that the voltage of the third conductive path is maintained at a voltage that cuts off the flow of current from the first conductive path to the third conductive path.

7. The vehicle-mounted backup control device according to any one of claims 1 to 6, wherein: The priority control includes a limit control for stopping the supply of electric power from the second power storage unit to the second load when the second power storage unit is in a predetermined state. The control unit performs the limit control according to the predetermined state until the cumulative operation time of the first load based on the first backup operation reaches a predetermined time.

8. The vehicle-mounted backup control device according to claim 7, wherein: The predetermined state is a state in which the open circuit voltage of the second power storage unit becomes equal to or lower than a cutoff voltage, and the cutoff voltage is set in a predetermined determination method.

9. The vehicle-mounted backup control device according to claim 1 or claim 2, wherein: The shared load is the second load.

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