On-vehicle back-up control device

Abstract

The present invention makes it possible to reduce the load of an on-vehicle power supply system during charging operation.　This on-vehicle back-up control device (10) comprises: a plurality of charge units (52, 62) that supply charging current on the basis of electric power supplied from a first power supply unit (20); and a regulation unit (11) that controls the charge units (52, 62). The charge units (52, 62) respectively perform an operation of supplying charging current to power storage units (31, 32). The regulation unit (11) regulates the charging operation of the charge units (52, 62) so as to cause the total value of the charging current flowing to the power storage units (31, 32) to fall within a permissible range.

Description

In-vehicle backup control device

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

[0002] Patent Document 1 discloses a power storage device that supplies power to a load from a power storage unit serving as a backup power source when the voltage of the main power source drops. This power storage device outputs a charge signal to a charging circuit when the vehicle starts to be used. Upon receiving the charge signal, the charging circuit charges the power from the main power source into the power storage unit.

[0003] Japanese Patent Application Laid-Open No. 2009-296808

[0004] In a power storage device such as that described in Patent Document 1, it is conceivable to provide a plurality of power storage units as backup power sources in order to increase the redundancy of the power supply to the load, etc. However, if a charging current of the same magnitude as that supplied to a single power storage unit as in the conventional case is supplied to each of the plurality of power storage units, the load on the power storage device will increase.

[0005] The present disclosure aims to reduce the load on an in-vehicle power supply system during charging operations.

[0006] One aspect of the present disclosure is an in-vehicle backup control device that is used in an in-vehicle power supply system having a first power supply unit and a second power supply unit having a plurality of storage units, and that performs backup operation of outputting power to a load based on power from the second power supply unit when power supply from at least the first power supply unit to the load fails, the in-vehicle backup control device having: a plurality of charging units that supply charging current based on power supplied from the first power supply unit; and an adjustment unit that controls the plurality of charging units, each of which operates to supply charging current to each of the storage units, and the adjustment unit adjusts the charging operation of the plurality of charging units so that the total value of the charging current to the plurality of storage units falls within an allowable range.

[0007] The technology according to the present disclosure can reduce the load on an in-vehicle power supply system during charging operations.

[0008] Fig. 1 is a block diagram that schematically illustrates an example of an in-vehicle power supply system including an in-vehicle backup control device of a first embodiment. Fig. 2 is a flowchart that illustrates an example of a control flow performed by the in-vehicle backup control device of the first embodiment. Fig. 3 is a flowchart that illustrates an example of a standby control flow for a second power supply unit. Fig. 4 is a block diagram that schematically illustrates an example of an in-vehicle power supply system including an in-vehicle backup control device of a second embodiment.

[0009] The following describes exemplary embodiments of the present disclosure. The following exemplary features [1] to [3] may be combined in any manner as long as they are not inconsistent.

[0010] [1] An in-vehicle backup control device used in an in-vehicle power supply system having a first power supply unit and a second power supply unit having a plurality of power storage units, which performs backup operation of outputting power to a load based on power from the second power supply unit when power supply from at least the first power supply unit to the load fails, the in-vehicle backup control device having a plurality of charging units that supply charging current based on power supplied from the first power supply unit, and an adjustment unit that controls the plurality of charging units, wherein each of the charging units operates to supply charging current to each of the power storage units, and the adjustment unit adjusts the charging operation of the plurality of charging units so that the total value of the charging current to the plurality of power storage units falls within an allowable range.

[0011] The in-vehicle backup control device of [1] above adjusts the charging operations of the multiple charging units so that the total value of the charging current to the multiple power storage units falls within an allowable range using the adjustment unit, and therefore can supply power from the first power supply unit so that the charging current falls within the allowable range. Therefore, by appropriately setting the allowable range of the charging current, the load on the in-vehicle power supply system can be reduced.

[0012] [2] The vehicle backup control device according to [1] has the following features: The adjustment unit includes a plurality of control units, a plurality of detection units, and an electronic control unit. The electronic control unit communicates with the plurality of control units. Each of the detection units detects a value of a charging current supplied to each of the charging units. Each of the control units controls each of the charging units, and transmits charging current information that can identify the value of the charging current detected by each of the detection units to the electronic control unit. The electronic control unit controls the plurality of control units based on the charging current information provided by the plurality of control units so that the total value of the charging current to the plurality of power storage units falls within an allowable range.

[0013] The vehicle-mounted backup control device of [2] above is configured such that the electronic control unit controls each control unit, and each control unit can control the charging unit based on the control of the electronic control unit, thereby simplifying the control of each control unit.

[0014] [3] The vehicle backup control device according to [1] has the following features: the adjustment unit includes a plurality of control units and a plurality of detection units. Each of the detection units detects a value of a charging current supplied to each of the charging units. Each of the control units controls each of the charging units. The plurality of control units communicate with each other and control the plurality of charging units based on the values ​​of the charging current detected by the plurality of detection units so that the total value of the charging current to the plurality of power storage units falls within an allowable value range.

[0015] In the above-mentioned in-vehicle backup control device [3], each control unit communicates with each other and controls the charging unit, so there is no need to provide a separate control device that controls each control unit in an integrated manner. Therefore, charging control can be completed by each control unit.

[0016] 1 includes a first power supply unit 20, a second power supply unit 30, loads 41 and 42, and an in-vehicle backup control device 10. The in-vehicle backup control device 10 is also simply referred to as the backup control device 10.

[0017] The first power supply unit 20 functions as a main power supply that continuously supplies power when the vehicle equipped with the in-vehicle power supply system 100 is started. The first power supply unit 20 is a DC power supply that generates a DC voltage. The first power supply unit 20 is configured by a battery such as a lead battery. A high-potential terminal of the first power supply unit 20 is electrically connected to the power path 80, and a low-potential terminal of the first power supply unit 20 is electrically connected to ground. The first power supply unit 20 applies a predetermined voltage to the power path 80. In this specification, unless otherwise specified, voltage refers to a voltage referenced to ground.

[0018] The first power supply unit 20 is electrically connected to the loads 41 and 42 via a power path 80. Power from the first power supply unit 20 is supplied to the loads 41 and 42 via the power path 80. In the example of FIG. 1 , the power path 80 includes a power path 81A that is a conductive path directly connected to the first power supply unit 20, a power path 81B that is connected to the load 41, and a power path 81C that is a conductive path connected to the load 42. The power paths 81A, 81B, and 81C are electrically connected to each other. When power is supplied from the first power supply unit 20 to the loads 41 and 42, the power paths 81A, 81B, and 81C are at the same potential. Relays, fuses, and the like (not shown) are provided in the power path 80, and these elements have the function of interrupting the conduction of the power path 80.

[0019] The loads 41 and 42 are in-vehicle electrical devices. The loads 41 and 42 are loads to which a power supply is desired in an abnormal state (failure state) in which the power supply from the first power supply unit 20 is stopped. The loads 41 and 42 may be, for example, actuators such as motors. Alternatively, the loads 41 and 42 may be ECUs and actuators in an electric parking brake system, ECUs and actuators in a shift-by-wire control system, or other in-vehicle electrical devices.

[0020] The backup control device 10 has an adjustment unit 11, a first charging / discharging unit 52, a first voltage detection unit 53, a second charging / discharging unit 62, and a second voltage detection unit 63. The adjustment unit 11 controls the first charging / discharging unit 52 and the second charging / discharging unit 62. The adjustment unit 11 includes an electronic control device 12, a first control unit 51, a first current detection unit 54, a second control unit 61, and a second current detection unit 64. The first charging / discharging unit 52 and the second charging / discharging unit 62 correspond to an example of a "charging unit" in the present disclosure. The first control unit 51 and the second control unit 61 correspond to an example of a "control unit" in the present disclosure. The first current detection unit 54 and the second current detection unit 64 correspond to an example of a "detection unit" in the present disclosure.

[0021] The electronic control unit 12 is a control unit different from the first control unit 51 and the second control unit 61. The electronic control unit 12 is a control unit that is not included in the first power storage unit 101 and the second power storage unit 102 described below. The electronic control unit 12 is configured as, for example, a higher-level ECU (Electronic Control Unit) mounted on the vehicle. The electronic control unit 12 is capable of communicating with the first control unit 51 and the second control unit 61. The electronic control unit 12 controls the first control unit 51 and the second control unit 61.

[0022] The backup control device 10 is a device that can perform backup operation to supply power to the loads 41, 42 based on the power of the second power supply unit 30 (first storage unit 31 and second storage unit 32) when the power supply from the first power supply unit 20 to the loads 41, 42 is cut off or reduced in a predetermined state (abnormal state).

[0023] The in-vehicle power supply system 100 includes a first power storage unit 101 and a second power storage unit 102. The first power storage unit 101 includes a first power storage unit 31, a first control unit 51, a first charge / discharge unit 52, a first voltage detection unit 53, and a first current detection unit 54. The second power storage unit 102 includes a second power storage unit 32, a second control unit 61, a second charge / discharge unit 62, a second voltage detection unit 63, and a second current detection unit 64.

[0024] The first power storage unit 31 and the second power storage unit 32 function as auxiliary power sources. The first power storage unit 31 and the second power storage unit 32 correspond to an example of a "power storage unit" in the present disclosure. The first power storage unit 31 and the second power storage unit 32 are DC power sources that output DC voltage, such as electric double layer capacitors. The first power storage unit 31 is electrically connected to a first charging / discharging unit 52 (described later) via a conductive path 55, and is charged and discharged via the first charging / discharging unit 52. The charging voltage (output voltage) of the first power storage unit 31 is the voltage applied to the conductive path 55. The high-potential terminal of the first power storage unit 31 is electrically connected to the conductive path 55 and has the same potential as the conductive path 55. The low-potential terminal of the first power storage unit 31 is electrically connected to the ground and has the same potential as the ground.

[0025] The second power storage unit 32 is electrically connected to a second charging / discharging unit 62 (described later) via a conductive path 65, and is charged and discharged via the second charging / discharging unit 62. The charging voltage (output voltage) of the second power storage unit 32 is the voltage applied to the conductive path 65. The high-potential terminal of the second power storage unit 32 is electrically connected to the conductive path 65 and has the same potential as the conductive path 65. The low-potential terminal of the second power storage unit 32 is electrically connected to the ground and has the same potential as the ground.

[0026] In the backup control device 10, when the vehicle equipped with the in-vehicle power supply system 100 is in a stopped state with the start switch in the OFF state, the charging voltage (output voltage) of the first power storage unit 31 and the second power storage unit 32 is maintained at or below the standby voltage. When the start switch of the vehicle is switched to the ON state, the backup control device 10 charges the first power storage unit 31 and the second power storage unit 32 so that the charging voltage thereof becomes equal to or higher than a target voltage that is higher than the standby voltage. When the start switch of the vehicle is in the ON state and no fault condition has occurred, the charging voltage of the first power storage unit 31 and the second power storage unit 32 is maintained at the target voltage. When the start switch of the vehicle is switched from the ON state to the OFF state, the backup control device 10 discharges the first power storage unit 31 and the second power storage unit 32 until the charging voltage of the first power storage unit 31 and the second power storage unit 32 becomes equal to or lower than the standby voltage.

[0027] The first charging / discharging unit 52 functions to supply a charging current to the first power storage unit 31 based on the power supplied from the first power supply unit 20, and also functions to output the power based on the first power storage unit 31 to the load 41. The first charging / discharging unit 52 operates under the control of a first control unit 51, which will be described later. The first charging / discharging unit 52 is disposed between a conductive path 56 and a conductive path 57. The conductive path 57 is a conductive path between the first charging / discharging unit 52 and the load 41. The first charging / discharging unit 52 has a voltage conversion circuit, such as a DC / DC converter. The voltage conversion circuit performs a charging operation and a discharging operation for the first power storage unit 31. The voltage conversion circuit performs a charging operation, which increases or decreases the voltage applied to the conductive path 56 and applies the resulting voltage to the conductive path 55. The voltage conversion circuit performs a discharging operation, which increases or decreases the voltage applied to the conductive path 55 and applies the resulting voltage to the conductive path 57.

[0028] The second charging / discharging unit 62 functions to supply a charging current to the second power storage unit 32 based on the power supplied from the first power supply unit 20, and also functions to output the power based on the second power storage unit 32 to the load 42. The second charging / discharging unit 62 operates under the control of a second control unit 61, which will be described later. The second charging / discharging unit 62 is disposed between a conductive path 66 and a conductive path 67. The conductive path 67 is a conductive path between the second charging / discharging unit 62 and the load 42. The second charging / discharging unit 62 has a voltage conversion circuit, such as a DC / DC converter. The voltage conversion circuit performs a charging operation and a discharging operation for the second power storage unit 32. The voltage conversion circuit performs a charging operation, which increases or decreases the voltage applied to the conductive path 66 and applies the resulting voltage to the conductive path 65. The voltage conversion circuit performs a discharging operation, which increases or decreases the voltage applied to the conductive path 65 and applies the resulting voltage to the conductive path 67.

[0029] The first control unit 51 controls the operation of supplying power from the first power storage unit 31 to the load 41. The first control unit 51 is an information processing device having information processing functions, calculation functions, control functions, etc. The first control unit 51 is mainly configured, for example, with a microcomputer and has a calculation unit 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, etc. The first control unit 51 has a function of controlling the first charging / discharging unit 52. The first control unit 51 transmits charging current information that can identify the value of the charging current detected by the first current detection unit 54 to the electronic control device 12. The charging current information may be the actual value of the charging current detected by the first current detection unit 54, or a value obtained by correcting the value of the charging current.

[0030] The second control unit 61 controls the operation of supplying power from the second power storage unit 32 to the load 42. The second control unit 61 is an information processing device having information processing functions, calculation functions, control functions, etc. The second control unit 61 is mainly configured, for example, with a microcomputer and has a calculation unit such as a CPU (Central Processing Unit), memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), an A / D converter, etc. The second control unit 61 has a function of controlling the second charging / discharging unit 62. The second control unit 61 transmits charging current information that can identify the value of the charging current detected by the second current detection unit 64 to the electronic control device 12. The charging current information may be the actual value of the charging current detected by the second current detection unit 64, or a value obtained by correcting the value of the charging current.

[0031] The first voltage detection unit 53 is configured as, for example, a voltage detection circuit. The first voltage detection unit 53 detects the voltage of the conductive path 56. The conductive path 56 is electrically connected to the power path 80 and has the same potential as the power path 80. Therefore, the first voltage detection unit 53 can detect the voltage of the power path 80.

[0032] The second voltage detection unit 63 is configured as, for example, a voltage detection circuit. The second voltage detection unit 63 detects the voltage of the conductive path 66. The conductive path 66 is electrically connected to the power path 80 and has the same potential as the power path 80. Therefore, the second voltage detection unit 63 can detect the voltage of the power path 80.

[0033] The first current detection unit 54 is configured as, for example, a current detection circuit. The first current detection unit 54 detects the value of the current flowing through the conductive path 56. The first current detection unit 54 detects the value of the charging current supplied to the first charging / discharging unit 52. The current value detected by the first current detection unit 54 is a value (specifically, an analog voltage value) that can identify the current value of the conductive path 56.

[0034] The second current detection unit 64 is configured as, for example, a current detection circuit. The second current detection unit 64 detects the value of the current flowing through the conductive path 66. The second current detection unit 64 detects the value of the charging current supplied to the second charging / discharging unit 62. The current value detected by the second current detection unit 64 is a value (specifically, an analog voltage value) that can identify the current value of the conductive path 66.

[0035] [Control of Backup Control Device] The control shown in FIG. 2 is an example of backup control performed by the backup control device 10 (specifically, the electronic control device 12, the first control unit 51, and the second control unit 61). The backup control device 10 starts the backup control of FIG. 2 when a predetermined start condition is met. The condition for starting the backup control of FIG. 2 may be, for example, that the start switch of the vehicle equipped with the automotive power supply system 100 has been switched from an off state to an on state, or may be another condition. For example, when the start switch of the vehicle has been switched from an off state to an on state, a start signal indicating that the start switch has been switched on is input to the electronic control device 12. The backup control device 10 starts the backup control of FIG. 2 when the electronic control device 12 receives the start signal.

[0036] 2 starts, the backup control device 10 places the second power supply unit 30 (the first power storage unit 31 and the second power storage unit 32) in a standby state (step S11). The backup control device 10 charges the first power storage unit 31 and the second power storage unit 32 so that their charging voltages are equal to or higher than a target voltage that is higher than the standby voltage. The backup control device 10 maintains the charging voltages of the first power storage unit 31 and the second power storage unit 32 at the target voltage.

[0037] 3 is an example of a specific process of step S11. Backup control device 10 starts charging second power supply unit 30 (first power storage unit 31 and second power storage unit 32) (step S21). Adjustment unit 11 controls first charging / discharging unit 52 and second charging / discharging unit 62. First charging / discharging unit 52 supplies a charging current to first power storage unit 31 based on the power supplied from first power supply unit 20. Second charging / discharging unit 62 supplies a charging current to second power storage unit 32 based on the power supplied from first power supply unit 20.

[0038] Next, the backup control device 10 adjusts the charging operations of the first charging / discharging unit 52 and the second charging / discharging unit 62 (step S22). The adjustment unit 11 adjusts the charging operations of the first charging / discharging unit 52 and the second charging / discharging unit 62 so that the total value of the charging current to the first power storage unit 31 and the second power storage unit 32 falls within the allowable range. Specifically, the electronic control device 12 controls the first control unit 51 and the second control unit 61 based on the charging current information provided by the first control unit 51 and the second control unit 61 so that the total value of the charging current to the first power storage unit 31 and the second power storage unit 32 falls within the allowable range. The allowable range is a preset range of current values, for example, a range greater than 0 and equal to or less than the maximum allowable current value in the automotive power supply system 100. The upper limit of the allowable range (allowable threshold) is, for example, a value smaller than the maximum current value that can flow through a fuse provided in the power path 80, etc. The allowable threshold may be a fixed value or may be changeable.

[0039] The charging current information provided by the first control unit 51 is set to the current value (first current value Ia) detected by the first current detection unit 54. The charging current information provided by the second control unit 61 is set to the current value (second current value Ib) detected by the second current detection unit 64. For example, the electronic control unit 12 determines whether the sum of the first current value Ia and the second current value Ib is equal to or less than the allowable threshold value Imax. If the electronic control unit 12 determines that Ia + Ib > Imax, it performs feedback control so that the sum of the charging current value I1 supplied to the first power storage unit 31 by the first charging / discharging unit 52 and the charging current value I2 supplied to the second power storage unit 32 by the second charging / discharging unit 62 is equal to or less than Imax. For example, the electronic control unit 12 controls I1 and I2 so that I1 and I2 are equal to each other and I1 + I2 ≦ Imax. For example, the electronic control unit 12 controls I1 to Imax / 2 and I2 to Imax / 2. Note that I1 and I2 may be controlled to current values ​​lower than Imax / 2 in proportions corresponding to Ia and Ib, respectively. On the other hand, if the electronic control unit 12 determines that Ia + Ib ≤ Imax, it continues the charging operations of the first charging / discharging unit 52 and the second charging / discharging unit 62 without making any adjustments.

[0040] The electronic control unit 12 may also perform feedback control as follows. For example, assume that after starting charging in step S21, the electronic control unit 12 performs constant-voltage charging by controlling the first charge / discharge unit 52 and the second charge / discharge unit 62. In this case, the electronic control unit 12 determines whether the sum of the current value (first current value Ic) detected by the first current detection unit 54 and the current value (second current value Id) detected by the second current detection unit 64 is equal to or less than the allowable threshold value Imax. If the electronic control unit 12 determines that Ic + Id > Imax, it performs feedback control so that the sum of the charging current values ​​I1 and I2 is equal to or less than Imax. For example, the electronic control unit 12 controls I1 and I2 so that I1 + I2 ≦ Imax. For example, the electronic control unit 12 controls I1 to Imax / 2 and I2 to Imax / 2. It should be noted that I1 and I2 may be controlled to current values ​​lower than Imax / 2.

[0041] Subsequently, in step S23, when the backup control device 10 determines that charging of the second power supply unit 30 (first power storage unit 31 and second power storage unit 32) is completed, the backup control device 10 terminates the charging control of Fig. 3. The backup control device 10 determines that charging is completed when the output voltage of the first power storage unit 31 reaches the target voltage and the output voltage of the second power storage unit 32 reaches the target voltage.

[0042] After charging of the second power supply unit 30 is completed, the backup control device 10 determines whether the power supply from the first power supply unit 20 (main power supply) to the loads 41 and 42 has failed in step S12 of FIG. A failure in the power supply from the first power supply unit 20 occurs, for example, when the voltage of the power path 80 through which power is supplied from the first power supply unit 20 falls below a threshold voltage. The threshold voltage is, for example, a fixed value greater than zero and significantly smaller than the output voltage that the first power supply unit 20 normally applies to the power path 80. However, the threshold voltage may be changeable. For example, the first control unit 51 determines whether the voltage of the conductive path 56 is below the threshold (a predetermined drop state) based on the voltage detected by the first voltage detection unit 53. In an abnormal state in which a ground fault or disconnection occurs in the power path 80 and the power supply from the first power supply unit 20 to the conductive path 56 is interrupted, the voltage of the conductive path 56 becomes approximately 0 V. The second control unit 61 may determine whether the voltage of the conductive path 66 is below a threshold value (is in a predetermined decreased state) based on the voltage detected by the second voltage detection unit 63 .

[0043] In step S12, if the backup control device 10 determines that the power supply from the first power supply unit 20 to the loads 41 and 42 is in a failure state, the process proceeds to Yes and the process of step S13 is performed. On the other hand, in step S12, if the backup control device 10 determines that the power supply from the first power supply unit 20 to the loads 41 and 42 is not in a failure state, the process proceeds to No and the process of step S11 is performed again.

[0044] In step S13, the backup control device 10 starts a backup operation. The backup control device 10 supplies power from the second power supply unit 30 to the loads 41 and 42. When the first control unit 51 supplies power based on the first power storage unit 31 to the load 41, the first control unit 51 operates so that a voltage (a voltage of magnitude V1) based on the output voltage of the first power storage unit 31 is applied to the conductive path 57. The voltage V1 is a voltage obtained by increasing or decreasing the output voltage from the first power storage unit 31 using the voltage conversion circuit of the first charging / discharging unit 52. Similarly, when the second control unit 61 supplies power based on the second power storage unit 32 to the load 42, the second control unit 61 operates so that a voltage (a voltage of magnitude V2) based on the output voltage of the second power storage unit 32 is applied to the conductive path 67. The voltage V2 is a voltage obtained by increasing or decreasing the output voltage from the second power storage unit 32 using the voltage conversion circuit of the second charging / discharging unit 62.

[0045] If the backup control device 10 determines in the next step S14 that the vehicle equipped with the automotive power supply system 100 is in a stopped state, the backup control shown in Fig. 2 is terminated. Specifically, the electronic control device 12 determines whether the start switch of the vehicle equipped with the automotive power supply system 100 has been switched from an on state to an off state. For example, when the start switch of the vehicle is switched from an on state to an off state, a signal indicating that the start switch has been switched to an off state is sent to the electronic control device 12.

[0046] The following description relates to an example of the effect of this configuration. In the backup control device 10 of the first embodiment, the adjustment unit 11 adjusts the charging operations of the first charging / discharging unit 52 and the second charging / discharging unit 62 so that the total value of the charging current to the first power storage unit 31 and the second power storage unit 32 falls within an allowable range, and therefore, power can be supplied from the first power supply unit (main power supply) 20 so that the charging current falls within the allowable range. Therefore, by appropriately setting the allowable range of the charging current, the load on the automotive power supply system 100 can be reduced.

[0047] The backup control device 10 of the first embodiment is configured such that the electronic control device 12 controls the first control unit 51 and the second control unit 61, and therefore the first control unit 51 and the second control unit 61 can control the first charge / discharge unit 52 and the second charge / discharge unit 62, respectively, based on the control of the electronic control device 12. This allows for simplified control of the first control unit 51 and the second control unit 61.

[0048] Second Embodiment An in-vehicle power supply system 200 of the second embodiment is different from the first embodiment in that it does not include an electronic control unit 12 and that a first control unit 51 and a second control unit 61 are capable of communicating with each other, but is otherwise the same as the first embodiment. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0049] 4, the automotive power supply system 200 includes a first power supply unit 20, a second power supply unit 30, loads 41 and 42, and a backup control device 210. The backup control device 210 includes an adjustment unit 211, a first charge / discharge unit 52, a first voltage detection unit 53, a second charge / discharge unit 62, and a second voltage detection unit 63. The adjustment unit 211 includes a first control unit 51, a first current detection unit 54, a second control unit 61, and a second current detection unit 64.

[0050] The first control unit 51 and the second control unit 61 can communicate with each other. The first control unit 51 can transmit, to the second control unit 61, charging current information that can identify the value of the charging current detected by the first current detection unit 54. The second control unit 61 can transmit, to the first control unit 51, charging current information that can identify the value of the charging current detected by the second current detection unit 64.

[0051] [Operation of Backup Control Device] The backup control device 210 of the second embodiment performs the control shown in Figures 2 and 3, similar to the backup control of the first embodiment. The backup control performed by the backup control device 210 (specifically, the first control unit 51 and the second control unit 61) differs from that of the first embodiment mainly in the charge control (step S22) shown in Figure 3.

[0052] In step S22, first control unit 51 and second control unit 61 adjust the charging operations of first charging / discharging unit 52 and second charging / discharging unit 62. First control unit 51 and second control unit 61 adjust the charging operations of first charging / discharging unit 52 and second charging / discharging unit 62 so that the total value of the charging current to first power storage unit 31 and second power storage unit 32 falls within an allowable range. Specifically, first control unit 51 and second control unit 61 communicate with each other and control the charging operations of first charging / discharging unit 52 and second charging / discharging unit 62 so that the total value of the charging current to first power storage unit 31 and second power storage unit 32 falls within an allowable range based on the charging current value detected by first current detection unit 54 and the charging current value detected by second current detection unit 64. The allowable range is the same as the allowable range defined in the first embodiment.

[0053] For example, the second control unit 61 controls the charging operations of the first charging / discharging unit 52 and the second charging / discharging unit 62 based on the charging current information (first current value) provided by the first control unit 51. The second control unit 61 controls the first control unit 51 through communication and causes the first control unit 51 to perform the charging operation of the first charging / discharging unit 52. The feedback control (step S22) performed by the second control unit 61 is similar to the control performed by the electronic control unit 12 in step S22 in the first embodiment (feedback control for keeping the sum of the charging current value I1 and the charging current value I2 equal to or less than Imax).

[0054] The following description relates to an example of the effect of this configuration. In the backup control device 10 of the second embodiment, the first control unit 51 and the second control unit 61 communicate with each other to control the first charging / discharging unit 52 and the second charging / discharging unit 62. Therefore, there is no need to provide a separate control device that comprehensively controls the first control unit 51 and the second control unit 61. Therefore, charging control can be completed by the first control unit 51 and the second control unit 61.

[0055] <Other Embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of features of the above-described or below-described embodiments is possible within a range that does not contradict. Furthermore, any feature of the above-described or below-described embodiments may be omitted unless explicitly stated as essential. Furthermore, the above-described embodiments may be modified as follows.

[0056] In the first embodiment, the in-vehicle power supply system 100 includes two power storage units (the first power storage unit 101 and the second power storage unit 102). However, the in-vehicle power supply system 100 may include three or more power storage units having similar configurations. That is, the second power supply unit 30 may include three or more power storage units. Three or more control units control corresponding charge / discharge units, and each charge / discharge unit supplies a charging current to each power storage unit. Based on charging current information provided by the three or more control units, the electronic control unit 12 controls each control unit so that the total value of the charging current to the three or more power storage units falls within an allowable range. Similarly, in the second embodiment, the three or more control units communicate with each other and, based on the charging current values ​​detected by the corresponding current detection units, control each charging unit so that the total value of the charging current to the corresponding power storage units falls within an allowable range.

[0057] In the above second embodiment, the second control unit 61 controlled the charging operations of the first charging / discharging unit 52 and the second charging / discharging unit 62 based on the charging current information (first current value) provided by the first control unit 51, but the first control unit 51 may also control the charging operations of the first charging / discharging unit 52 and the second charging / discharging unit 62 based on the charging current information (second current value) provided by the second control unit 61.

[0058] In the first and second embodiments described above, the predetermined state in step S12 of the backup control of the backup control device 10 is a state in which the voltage of the conductive path 56 is less than the threshold value, but other states may also be used. For example, the predetermined state may be a state in which a backup operation is requested by the load (specifically, a state in which at least one of the first control unit 51 and the second control unit 61 has received a signal from the load requesting a backup operation).

[0059] In the first and second embodiments, a start switch for a vehicle is described, but the start switch may be an ignition switch, or in the case of an electric vehicle, it may be a power switch for controlling an EV system.

[0060] In the first and second embodiments, the first power supply unit 20 is a lead battery, but is not limited to a lead battery. The first power supply unit 20 may be, for example, another type of battery such as a lithium ion battery, or may be a power source such as an alternator or a converter.

[0061] In the first and second embodiments, the first and second power storage units 31 and 32 are electric double layer capacitors, but the power storage units are not limited to electric double layer capacitors. The first and second power storage units 31 and 32 may be other types of power storage units, such as lithium ion capacitors and lithium ion batteries.

[0062] In the first and second embodiments described above, the backup control device performs backup operation when the power supply from the power supply unit is cut off, but the backup control device may also perform backup operation to supply power from the storage unit in a specified state where the power supply is not completely cut off.

[0063] It should be noted that the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope indicated by the claims or within the scope equivalent to the claims.

[0064] DESCRIPTION OF SYMBOLS 10... Backup control device 11... Adjustment section 12... Electronic control device 20... First power supply section 30... Second power supply section 31... First power storage section (power storage section) 32... Second power storage section (power storage section) 41, 42... Load 51... First control section (control section) 52... First charge / discharge section (charging section) 53... First voltage detection section 54... First current detection section (detection section) 55, 56, 57... Conduction path 61... Second control section (control section) 62... Second charge / discharge section (charging section) 63... Second voltage detection section 64... Second current detection section (detection section) 65, 66, 67... Conduction path 80... Power path 81A, 81B, 81C... Power path 100... In-vehicle power supply system 101... First power storage unit 102... Second power storage unit 200... In-vehicle power supply system 210: Backup control device 211: Adjustment unit

Claims

1. An in-vehicle backup control device used in an in-vehicle power supply system having a first power supply unit and a second power supply unit having a plurality of power storage units, which performs backup operation of outputting power to a load based on power from the second power supply unit when power supply to the load from at least the first power supply unit fails, the backup control device having: a plurality of charging units that supply charging current based on power supplied from the first power supply unit; and an adjustment unit that controls the plurality of charging units, each of which operates to supply charging current to each of the power storage units, and the adjustment unit adjusts the charging operation of the plurality of charging units so that the total value of the charging current to the plurality of power storage units falls within an allowable range.

2. The vehicle-mounted backup control device according to claim 1, wherein the adjustment unit comprises a plurality of control units, a plurality of detection units, and an electronic control unit, the electronic control unit communicates with the plurality of control units, each of the detection units detects a value of the charging current supplied to each of the charging units, each of the control units controls the respective charging units, and transmits charging current information that can identify the value of the charging current detected by each of the detection units to the electronic control unit, and the electronic control unit controls the plurality of control units based on the charging current information provided by the plurality of control units so as to keep the total value of the charging current to the plurality of power storage units within an allowable range.

3. The vehicle-mounted backup control device according to claim 1, wherein the adjustment unit comprises a plurality of control units and a plurality of detection units, each of the detection units respectively detecting the value of the charging current supplied to each of the charging units, each of the control units respectively controlling each of the charging units, and the plurality of control units communicating with each other and controlling the plurality of charging units based on the values ​​of the charging current detected by the plurality of detection units so as to keep the total value of the charging current to the plurality of storage units within an allowable value range.

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