JP2022174606A - Power control device - Google Patents

Abstract

To provide a technology capable of appropriately operating a load even when one of two batteries fails.SOLUTION: A power control device is used in a power supply system mounted on a vehicle. A power supply system includes a first battery that outputs a first voltage, a second battery that outputs a second voltage to a conductive path to which a load is electrically connected, and a voltage output unit that outputs a third voltage to the conductive path on the basis of the first voltage. The power control device includes a control unit that controls the voltage output unit. The control unit maintains the value of the third voltage at the first set value during a predetermined time when a stop instruction operation is performed on the vehicle to instruct to stop the operation of the vehicle in a case in which the value of the third voltage is set to the first set value.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a power control device.

Patent Literature 1 describes a power supply device that includes a high-voltage battery and a low-voltage battery. In the power supply device of Patent Document 1, a voltage generated based on the output voltage of the high-voltage battery (specifically, the output voltage of the DCDC converter) and the output voltage of the low-voltage battery are supplied to the load.

JP 2020-137247 A

In a system in which a voltage based on the output voltage of one battery and the output voltage of the other battery are supplied to a load, such as the power supply device of Patent Document 1, when a predetermined condition is satisfied, one battery The supply of voltage based on the output voltage to the load may be stopped. At this time, if the other battery is defective, the load cannot operate properly.

Therefore, it is an object of the present invention to provide a technology capable of appropriately operating a load even when one of two batteries fails.

A power supply control device of the present disclosure includes a first battery that outputs a first voltage, a second battery that outputs a second voltage to a conducting path electrically connected to a load, and a voltage output unit that outputs a third voltage based on the first voltage, and a power supply control device used in a power supply system mounted on a vehicle, the control unit comprising a control unit that controls the voltage output unit; The unit, when the value of the third voltage is set to the first set value, during a predetermined time, when a stop instruction operation instructing to stop the operation of the vehicle is performed on the vehicle, The value of the third voltage is maintained at the first set value.

According to the present disclosure, it is possible to appropriately operate the load even when the second battery fails.

FIG. 1 is a schematic diagram showing an example of the configuration of an in-vehicle system. FIG. 2 is a schematic diagram showing an example of the configuration of the power control device. FIG. 3 is a schematic diagram showing a non-volatile memory included in the power control device. FIG. 4 is a schematic diagram showing an example of the configuration of the vehicle control device. FIG. 5 is a flow chart showing an example of the operation of the in-vehicle system. FIG. 6 is a schematic diagram showing an example of time change of each voltage. FIG. 7 is a schematic diagram showing an example of time change of each voltage.

[Description of Embodiments of the Present Disclosure]
First, the embodiments of the present disclosure are listed and described.

The power control device of the present disclosure is as follows.

(1) a first battery that outputs a first voltage, a second battery that outputs a second voltage to a conductive path electrically connected to a load, and a voltage applied to the conductive path based on the first voltage; and a voltage output section for outputting a third voltage, the power supply control apparatus used in a power supply system mounted on a vehicle, comprising a control section for controlling the voltage output section, wherein the control section comprises the third When the value of the three voltages is set to the first set value, the third voltage is maintained for a predetermined time when a stop command operation is performed on the vehicle to instruct the vehicle to stop operating. maintain the value at the first set value. According to the present disclosure, when the value of the third voltage is set to the first set value and the vehicle is instructed to stop, the control unit changes the value of the third voltage for a predetermined time. Since the first set value is maintained, an appropriate voltage can be supplied to the load even if the second battery fails when the stop instruction operation is performed. Therefore, even if the second battery fails, the load can be properly operated.

(2) The control section may stop the voltage output section after the predetermined time has elapsed. In this case, since the control unit stops the voltage output unit after the lapse of the predetermined time, the voltage output unit can be stopped after the load performs necessary operations. Therefore, the power stored in the first battery is less likely to be consumed while appropriately operating the load.

(3) The control unit reduces the value of the third voltage to a second set value smaller than the first set value after the predetermined time has elapsed, and a detection unit that detects the voltage of the conducting path. and a determination unit that determines abnormality of the second battery based on the voltage of the conductive path detected by the detection unit when the value of the third voltage is set to the second set value. may In this case, if the second battery does not fail and the value of the second voltage is greater than the second set value, the voltage of the conduction path will be greater than the second set value. On the other hand, if the second battery has failed and the value of the second voltage is equal to or less than the second set value, the voltage of the conducting path will be the same value as the second set value. In this way, since the voltage of the conductive path changes depending on whether or not the second battery is defective, it is possible to appropriately determine whether the second battery is abnormal based on the voltage of the conductive path.

(4) A nonvolatile memory is further provided, and when the determination unit determines that the second battery is abnormal, the determination unit stores abnormality information indicating that the second battery is abnormal in the nonvolatile memory. good too. In this case, since the abnormality information indicating that the second battery is abnormal is stored in the nonvolatile memory, it is possible to identify that the second battery is abnormal based on the information in the nonvolatile memory. can be done.

(5) The nonvolatile memory may operate based on the voltage of the conduction path, and the control section may stop the voltage output section after the abnormality information is stored in the nonvolatile memory. In this case, since the voltage output unit stops after the abnormality information is stored in the nonvolatile memory that operates based on the voltage of the conductive path, the abnormality information is appropriately stored in the nonvolatile memory, and the accumulation of the first battery is performed. less power is consumed.

(6) The load includes a system for improving the safety of the vehicle, and the control unit terminates the predetermined time after the system performs processing for improving the safety of the vehicle. In this case, since the predetermined period of time ends after the process for improving the safety of the vehicle is performed, it is possible to appropriately improve the safety of the vehicle even if the second battery fails. can.

[Details of the embodiment of the present disclosure]
A specific example of the power supply control device of the present disclosure will be described below with reference to the drawings. It should be noted that the present invention is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope of equivalents to the scope of the claims.

<Overview of in-vehicle system>
FIG. 1 is a schematic diagram showing an example of a configuration of an in-vehicle system 2 including a power control device 34. As shown in FIG. The vehicle-mounted system 2 is a system mounted on the vehicle 1 . The vehicle 1 is, for example, a PHEV (Plug-in Hybrid Electric Vehicle) or an EV (Electric Vehicle).

The in-vehicle system 2 includes, for example, a power supply system 3 that supplies power to a load, a vehicle control device 10, an operation unit 11, a notification unit 12, a relay 15, and a shift-by-wire system 20 that electrically performs shift switching. Prepare. The shift-by-wire system 20 has, for example, a shift selector 13, an SBW controller 14, an actuator 16, and a transmission 17. The transmission 17 is, for example, an automatic transmission. In the shift-by-wire system 20, shift switching of the transmission 17 is performed electrically. SBW is an abbreviation for Shift By Wire. The shift-by-wire system 20 is hereinafter also referred to as the SBW system 20 .

The power supply system 3 can supply electric power (in other words, power supply) to the vehicle control device 10, the operation unit 11, and the SBW system 20, for example. The shift selector 13 , SBW control section 14 and actuator 16 of the SBW system 20 operate based on power from the power supply system 3 .

The power supply system 3 includes, for example, a first battery 31, a second battery 32, a voltage output section 33, and a power control device . Each of the first battery 31 and the second battery 32 is, for example, a rechargeable secondary battery. Each of the output voltage V1 of the first battery 31 (also referred to as the first voltage V1 or the first battery voltage V1) and the output voltage V2 of the second battery 32 (also referred to as the second voltage V2 or the second battery voltage V2) is a DC voltage. is. The output voltage V1 of the first battery 31 when fully charged is, for example, higher than the output voltage V2 of the second battery 32 when fully charged. The output voltage V1 of the first battery 31 when fully charged is +400V, for example. The output voltage V2 of the second battery 32 when fully charged is, for example, +12V. The values of the first battery voltage V1 and the second battery voltage V2 are not limited to this. A lithium ion battery, for example, is employed as the first battery 31 . The second battery 32 is, for example, a lead battery.

The voltage output unit 33 outputs a voltage V3 (also referred to as a third voltage V3) based on the first battery voltage V1. The voltage output unit 33 outputs the third voltage V3 to the conducting path 5 electrically connected to the load. The loads electrically connected to the conducting path 5 include, for example, the vehicle control device 10, the operation unit 11, the SBW system 20, and the power control device 34.

The voltage output unit 33 is, for example, a DC/DC converter that steps down and outputs the output voltage V1. The value of the third voltage V3 is smaller than the value of the first battery voltage V1. The value of the third voltage V3 is, for example, +14V, which is basically higher than the value of the output voltage V2 of the second battery 32 when fully charged. As will be described later, the control of the voltage output section 33 by the power control device 34 may cause the value of the third voltage V3 to be lower than the value of the output voltage V2 of the second battery 32 when fully charged.

A positive terminal of the second battery 32 is connected to the conducting path 5 . The second battery 32 outputs the second voltage V2 to the conductive path 5. FIG. Further, the second battery 32 is supplied with power from the voltage output section 33 through the conducting path 5 . The second battery 32 is charged with power supplied from the voltage output section 33 . Since the voltage output section 33 operates based on the power supplied from the first battery 31 , it can be said that the second battery 32 is charged by the power supplied from the first battery 31 through the voltage output section 33 . Conductive path 5 is configured by, for example, an electric wire.

As described above, in this example, the voltage output section 33 outputs the third voltage V3 and the second battery 32 outputs the second voltage V2 to the conducting path 5 . If the third voltage V3 is greater than the second voltage V2, the value of the voltage V5 of the conductive path 5 will be the same as the value of the third voltage V3. On the other hand, when the third voltage V3 is lower than the second voltage V2, the value of the voltage V5 of the conducting path 5 is the same as the value of the second voltage V2. A load (vehicle control device 10, etc.) electrically connected to the conductive path 5 is supplied with the voltage V5 of the conductive path 5 as a power supply voltage. A load electrically connected to the conducting path 5 operates based on power supplied from the first battery 31 or the second battery 32 through the conducting path 5 . Hereinafter, the voltage V5 of the conductive path 5 will also be referred to as a conductive path voltage V5. Moreover, simply speaking of a load means a load electrically connected to the conducting path 5 .

The power control device 34 is connected to the conductive path 5 and operates based on the conductive path voltage V5. The power control device 34 can control the voltage output section 33 to set the value of the output voltage V3.

The vehicle control device 10 is connected to the conducting path 5 and operates based on the conducting path voltage V5. The vehicle control device 10 can manage the operation of the entire in-vehicle system 2 by controlling other components of the in-vehicle system 2 . The vehicle control device 10 is, for example, an ECU (Electronic Control Unit) and is also called a body control module.

The operation unit 11 is connected to the conductive path 5 and operates based on the conductive path voltage V5. The operation unit 11 can receive an operation by a user such as a driver. The operation unit 11 can receive, for example, a start instruction operation for instructing the start of operation of the vehicle 1 . Further, the operation unit 11 can receive a stop instruction operation for instructing to stop the operation of the vehicle 1 . Upon receiving a user's operation, the operation unit 11 notifies the vehicle control device 10 of it.

The operation unit 11 is, for example, an ignition switch provided in a PHEV or the like, or a power switch provided in an EV or the like, and is called a starting switch. The operation unit 11 has, for example, mechanical operation buttons. This operation button is an ignition button when the vehicle 1 is a PHEV, and a power button when the vehicle 1 is an EV. For example, when the vehicle 1 is stationary and the transmission 17 is set to the P range, the user can perform a start instruction operation or a stop instruction operation by operating the operation button of the operation unit 11. can be done. The operation unit 11 is also called a push start switch.

Here, the start of operation of the vehicle 1 means that the vehicle 1 changes from the state in which the vehicle 1 cannot travel to the state in which the vehicle 1 can travel. Therefore, the start instruction operation is an operation for instructing the vehicle 1 to change from the state in which the vehicle 1 cannot travel to the state in which the vehicle 1 can travel. Stopping the operation of the vehicle 1 means that the vehicle 1 changes from a state in which it can travel to a state in which it cannot travel. Therefore, the stop instruction operation is an operation for instructing to change the vehicle 1 from the travelable state to the travel-impossible state. The drivable state means a state in which the vehicle 1 travels by transmitting power to the wheels of the vehicle 1 when the accelerator is stepped on while the shift range of the transmission 17 is set to a travel range such as the D range. . On the other hand, the non-running state means a state in which the vehicle 1 does not run because power is not transmitted to the wheels of the vehicle 1 even if the accelerator pedal is stepped on regardless of the shift range setting of the transmission 17 .

The start instruction operation is performed, for example, when the vehicle 1 is stopped, the transmission 17 is set to the P range, and the vehicle 1 is in a travel-impossible state (in other words, when the operation of the vehicle 1 is stopped). , is an operation in which an operation button of the operation unit 11 is pressed. When the operation unit 11 receives the start instruction operation, the vehicle 1 starts operating and becomes ready to run.

The stop instruction operation is performed, for example, when the vehicle 1 is stopped, the transmission 17 is set to the P range, and the vehicle 1 is in a travelable state (in other words, when the vehicle 1 is operating). This is the operation of pressing the operation button of the unit 11 . When the operation unit 11 receives a stop instruction operation, the vehicle 1 stops operating and becomes in a travel-impossible state.

The shift selector 13 is connected to the conductive path 5 and operates based on the conductive path voltage V5. The shift selector 13 is a shift-by-wire range selection device that receives a shift range selection operation by the driver. The shift selector 13 is arranged near the driver's seat of the vehicle 1 . The shift selector 13 includes, for example, a shift lever (also referred to as an operation lever), a P range selection button, a display, a sensor that detects displacement of the shift lever, a sensor that detects depression of the P range selection button, and the like. The shift selector 13 outputs to the vehicle control device 10 the output signals of the sensor that detects the displacement of the shift lever and the sensor that detects the depression of the P range selection button, thereby selecting the shift range selected by the driver (selected shift range). ) is notified to the vehicle control device 10 .

The SBW controller 14 is connected to the conductive path 5 and operates based on the conductive path voltage V5. The SBW control section 14 can control the relay 15 and the actuator 16 based on the notification from the vehicle control device 10 . The SBW control unit 14 is an ECU, for example.

The relay 15 can be switched between on and off under the control of the SBW control section 14 . A relay 15 is connected to the conductive path 5 . Conductive path voltage V5 is applied to actuator 16 when relay 15 is in the ON state. On the other hand, when the relay 15 is in the OFF state, the conductive path voltage V5 is not supplied to the actuator 16. The relay 15 is basically set to an ON state. Then, as will be described later, after the parking lock is executed, the relay 15 is changed from the ON state to the OFF state.

Actuator 16 is an electric actuator, and is electrically connected to conductive path 5 when relay 15 is in the ON state. Actuator 16 operates based on conductive path voltage V5 when relay 15 is in the ON state. The actuator 16 switches the shift range of the transmission 17 under the control of the SBW control section 14 . The actuator 16 has, for example, a motor and a speed reducer.

The transmission 17 has a parking lock mechanism 170, for example. The parking lock mechanism 170 is a mechanism that executes a parking lock that locks the rotation of the wheel shaft of the vehicle 1 . The operation of parking lock mechanism 170 is controlled by actuator 16 . The parking lock mechanism 170 includes, for example, a parking gear directly or indirectly connected to the wheel axle and a parking lock port engageable with the parking gear. The rotation of the wheel axle is locked by the parking lock port engaging the parking gear. Actuator 16 can move the parking lock port between an engaged position in which it engages parking gear and a disengaged position in which it does not engage parking gear. In this example, when the shift range of the transmission 17 is set to the P range by the actuator 16, the parking lock port is automatically engaged with the parking gear and the parking lock is executed. SBW system 20 including parking lock mechanism 170 is a system for improving the safety of vehicle 1 . Parking lock is a process for improving the safety of the vehicle 1 .

The notification unit 12 can notify at least one of a person and a device under the control of the vehicle control device 10 . The notification unit 12 may include a display unit such as a liquid crystal display that presents information to the driver. In addition, the notification unit 12 may include a sound generator that transmits sound to the driver. The sound generator may include a speaker or a buzzer. Also, the notification unit 12 may include a communication unit that notifies a device outside the vehicle 1 . The communication unit may perform wired communication or wireless communication.

In this example, the vehicle control device 10, the shift selector 13, the SBW control unit 14, and the power control device 4 can communicate using, for example, the CAN system. CAN is an abbreviation for Controller Area Network. In FIG. 1, the communication line 25 used in CAN system communication (also referred to as CAN communication) is indicated by a dashed line.

In the in-vehicle system 2 configured as described above, when the shift selector 13 notifies the selected shift range, the vehicle control device 10 notifies the SBW control unit 14 of the notified selected shift range. The SBW control unit 14 controls the actuator 16 to set the shift range of the transmission 17 to the selected shift range. In parking lock mechanism 170, the parking lock port is engaged with the parking gear in response to setting the shift range of transmission 17 to the P range, and parking lock is executed. After the parking lock port engages the parking gear, that state is mechanically maintained. Therefore, after the parking lock is executed, the parking lock state is mechanically maintained even if the actuator 16 is not driven.

<Configuration example of power supply control device>
FIG. 2 is a schematic diagram showing an example of the configuration of the power control device 34. As shown in FIG. As shown in FIG. 2, the power control device 34 includes, for example, a control section 340 that controls the voltage output section 33, a detection section 350 that detects the conductive path voltage V5, and a communication section 360. The control unit 340, the detection unit 350, and the communication unit 360 operate based on the conduction path voltage V5, for example.

The control unit 340 is a kind of computer, and can also be called a control circuit. The control unit 340 is composed of, for example, an MCU (Micro Controller Unit). The control unit 340 includes, for example, a CPU (Central Processing Unit) 341 which is a kind of processor, and a storage unit 345 . The storage unit 345 can also be called a storage circuit. The storage unit 345 includes non-temporary recording media readable by the CPU 341, such as ROM (Read Only Memory) and RAM (Random Access Memory). The storage unit 345 stores a program 345a for controlling the power supply control device 34 and the like. Various functions of the control unit 340 are realized by the CPU 341 executing a program 345 a in the storage unit 345 .

The control section 340 can control the voltage output section 33 to set the value of the output voltage V3 of the voltage output section 33 . In this example, the CPU 341 executes the program 345a to form a determination unit 341a for determining abnormality of the second battery 32 as a functional block. When determining that the second battery 32 is abnormal, the determination unit 341a generates abnormality information 346a indicating that the second battery 32 is abnormal. In this example, the control unit 340 can control the voltage output unit 33 and can determine whether the second battery 32 is abnormal. The control unit 340 can exchange information with the vehicle control device 10 .

As shown in FIG. 3, the storage unit 345 has a non-volatile memory 346, for example. The nonvolatile memory 346 stores abnormality information 346a generated by the determination unit 341a. The nonvolatile memory 346 is, for example, a nonvolatile memory to which data can be written by the CPU 341 . Non-volatile memory 346 may be, for example, EEPROM (Electrically Erasable Programmable ROM), flash ROM, or other non-volatile memory.

Note that the configuration of the control unit 340 is not limited to the above example. For example, the control unit 340 may include multiple CPUs 341 . Also, the control unit 340 may be provided with a processor capable of executing a program other than the CPU. The storage unit 345 may also include a non-temporary computer-readable recording medium other than the ROM and RAM. Also, all the functions of the control unit 340 or part of the functions of the control unit 340 may be implemented by hardware circuits that do not require software to implement the functions.

The detector 350 is connected to the conductive path 5 . It can be said that the detection unit 350 is a voltage sensor that detects the conduction path voltage V5. A detection result of the detection unit 350 is input to the control unit 340 . The communication unit 360 can perform, for example, CAN communication with a device external to the power control device 34 . The communication unit 360 can also be said to be a communication circuit. The communication unit 360 can communicate not only with devices within the in-vehicle system 2 but also with devices external to the in-vehicle system 2 (also referred to as external devices). The non-system device includes, for example, a personal computer, a mobile phone such as a smart phone, a tablet, and the like. The communication unit 360 can transmit, for example, the abnormality information 346a in the nonvolatile memory 346 to an external device. Note that the control unit 340 may exchange information with the vehicle control device 10 through the communication unit 360 .

<Configuration example of vehicle control device>
FIG. 4 is a schematic diagram showing an example of the configuration of the vehicle control device 10. As shown in FIG. As shown in FIG. 4 , the vehicle control device 10 includes, for example, a control section 100 and a communication section 110 . The control unit 100 and the communication unit 110 operate based on the conductive path voltage V5, for example. In this example, the SBW control unit 14 also has a configuration similar to that shown in FIG.

The control unit 100 is a kind of computer, and can also be called a control circuit. The control unit 100 is composed of, for example, an MCU. The control unit 100 includes a CPU 101 and a storage unit 105, for example. The storage unit 105 includes non-temporary recording media such as ROM and RAM that are readable by the CPU 101 . A program 105 a for controlling the vehicle control device 10 and the like are stored in the storage unit 105 . Various functions of the control unit 100 are realized by the CPU 101 executing a program 105 a in the storage unit 105 . The control unit 100 can exchange information with the control unit 340 of the power control device 34 .

Note that the configuration of the control unit 100 is not limited to the above example. For example, the control unit 100 may include multiple CPUs 101 . Also, the control unit 100 may include a processor capable of executing a program other than the CPU. The storage unit 105 may also include a non-temporary computer-readable recording medium other than the ROM and RAM. Further, all functions of the control unit 100 or part of the functions of the control unit 100 may be implemented by hardware circuits that do not require software to implement the functions.

The communication unit 110 can perform, for example, CAN communication with a device external to the vehicle control device 10 . The communication unit 110 may communicate not only with devices inside the in-vehicle system 2 but also with devices outside the in-vehicle system 2 (that is, external devices). Note that the control unit 100 may exchange information with the power control device 34 through the communication unit 110 .

<Example of in-vehicle system operation>
FIG. 5 is a flow chart showing an example of the operation of the in-vehicle system 2. As shown in FIG. FIG. 5 shows an example of operations of the vehicle control device 10, the power source control device 34, and the SBW system 20 when the vehicle 1 is instructed to stop.

In this example, when the vehicle 1 is in a running state and when the vehicle 1 is in a running-ready state, the power supply control device 34 changes the value of the third voltage V3 output from the voltage output section 33 to the first set value. set to The first set value is greater than the value of the output voltage V2 of the second battery 32 when fully charged, for example +14V. Then, as will be described later, after the vehicle 1 is instructed to stop, the power supply control device 34 sets the value of the third voltage V3 to a second set value that is smaller than the first set value. Further, the relay 15 is on when the vehicle 1 is running and when the vehicle 1 is ready to run.

When the shift selector 13 notifies the vehicle control device 10 of the selection of the P range, in step s1, the control unit 100 of the vehicle control device 10 recognizes that the driver has selected the P range. Then, in step s2, the control section 100 notifies the SBW control section 14 of the SBW system 20 of the selection of the P range. In the SBW system 20, the shift range of the transmission 17 is set to the P range by the SBW control section 14 controlling the actuator 16 in step s11. Then, in the SBW system 20, in step s12, parking lock is automatically executed according to the setting of the P range. After step s12, the parking lock is maintained mechanically. Note that the setting of the P range in step s11 and the execution of the parking lock in step s12 may be performed substantially at the same time.

After step s1, when the operation unit 11 notifies the vehicle control device 10 that the stop instruction operation has been performed, the control unit 100 recognizes that the stop instruction operation has been performed on the vehicle 1 in step s3. do. Then, in step s4, the control unit 100 notifies the control unit 340 of the power source control device 34 that the vehicle 1 has been instructed to stop.

After step s4, in step s21, the control section 340 maintains the value of the third voltage V3 output from the voltage output section 33 at the first set value for a predetermined period of time. That is, the control unit 340 continues setting the value of the third voltage V3 to the first set value (for example, +14 V) for a predetermined period of time from the notification of step s4 even after receiving the notification of step s4. Then, for example, immediately after the predetermined time has elapsed, the control unit 340 reduces the value of the third voltage V3 to set it to the second set value in step s22.

The predetermined time (also called maintenance time) in step s21 is set, for example, to a time such that step s22 is always executed after the parking lock is executed in step s12. The maintenance time is set, for example, from several minutes to ten and several minutes.

After the value of the third voltage V3 is set to the second set value in step s22, in step s23, the determination unit 341a of the control unit 340 determines the second voltage based on the conduction path voltage V5 detected by the detection unit 350. Abnormality determination for determining abnormality of the battery 32 is performed.

The second set value is set, for example, to a value slightly smaller than the lower limit of the normal range of the second battery voltage V2. Here, in the specifications of the in-vehicle system 2, the lower limit of the normal range of the second battery voltage V2 and the lower limit of the driving voltage for driving the SBW system 20 are predetermined. The lower limit of the driving voltage of the SBW system 20 is set smaller than the lower limit of the normal range of the second battery voltage V2. The lower limit value of the normal range of the second battery voltage V2 is set, for example, to a voltage value at which the overdischarge protection circuit of the second battery 32 operates. Assuming that the lower limit of the normal range of the second battery voltage V2 is MIN1 and the lower limit of the drive voltage of the SBW system 20 is MIN2, the second set value is set to, for example, (MIN2+α)≦second set value<MIN1. be. Here, α is a value set based on the voltage drop until the third voltage V3 is supplied from the voltage output section 33 to the SBW system 20, the tolerance of each device, and the like. For example, if MIN1=8.0V, MIN2=7.0V, and α=0.5V, the second set value is set to 7.5V or more and less than 8.0V. If the value of the conductive path voltage V5 is (MIN2+α) or more, each component (SBW control unit 14, etc.) of the SBW system 20 that improves the safety of the vehicle 1 can appropriately operate based on the conductive path voltage V5. can.

Also, the second set value is set to, for example, the lower limit value or more of the power supply voltage range in which the power supply control device 34 can operate. This allows the power control device 34 to execute step s23 after step s22. Assuming that the lower limit value of the power supply voltage range in which the power supply control device 34 can operate is, for example, 4.5 V, when the second set value is set to 7.5 V or more and less than 8.0 V, the second 2 set value is greater than or equal to the lower limit value.

In step s23, the determination unit 341a determines that the second battery 32 is abnormal when the value of the conduction path voltage V5 detected by the detection unit 350 matches the second set value. That is, the determination unit 341a determines that the second battery 32 is defective when the value of the conductive path voltage V5 detected by the detection unit 350 matches the second set value. On the other hand, the determination unit 341a determines that the second battery 32 is not abnormal when the value of the conductive path voltage V5 detected by the detection unit 350 does not match the second set value.

FIG. 6 is a diagram showing an example of temporal changes of the second battery voltage V2, the third voltage V3, and the conduction path voltage V5 when the second battery 32 is not defective. FIG. 7 is a diagram showing an example of temporal changes in the second battery voltage V2, the third voltage V3, and the conduction path voltage V5 when the second battery 32 is defective. In the example of FIG. 6, the value of the second voltage V2 of the second battery 32 that has not failed is +12V. In the example of FIG. 7, the value of the second voltage V2 of the second battery 32 in which failure has occurred is +3V. In FIGS. 6 and 7, the time variations of the second voltage V2, the third voltage V3 and the conductive path voltage V5 are shown by waveforms 502, 503 and 505, respectively.

As shown in FIGS. 6 and 7, when step s4 is notified at time t1, power supply control device 34 maintains the value of third voltage V3 at the first set value for maintenance time T. FIG. Since the first set value is greater than the value of the second battery voltage V2 (+12 V or +3 V in this example), the value of the conduction path voltage V5 (see waveform 505) during the sustain time T is greater than the value of the third voltage V3. value (see waveform 503). Further, in the SBW system 20, step s12 is executed at time t11 before time t2 at which the maintenance time T ends, and the parking lock is executed.

When the sustain time T ends at time t2, the power supply control device 34 reduces the value of the third voltage V3 to the second set value, as indicated by the waveform 503. FIG. In the example of FIG. 6, the second setpoint is less than the value of the second battery voltage V2 (i.e., +12V), so the value of the conductive path voltage V5 drops to the second setpoint, as shown in waveform 505. It becomes the same as the value of the second battery voltage V2 (that is, +12V). In the example of FIG. 6, the value of the conductive path voltage V5 is greater than the second set value. On the other hand, in the example of FIG. 7, the second set value is greater than the value of the second battery voltage V2 (i.e., +3V), so the value of the conductive path voltage V5, as shown in waveform 505, is at the second set value. value and becomes the same as the second set value.

In this manner, when the second battery 32 is normal and the value of the second battery voltage V2 is greater than the second set value, the value of the conductive path voltage V5 is greater than the second set value and the second set value does not match On the other hand, if the second battery 32 has failed and the value of the second battery voltage V2 is equal to or lower than the second set value, the value of the conduction path voltage V5 will match the second set value. The determination unit 341a determines that the second battery 32 is defective when the value of the conduction path voltage V5 detected by the detection unit 350 matches the second set value.

As described above, in this example, the second set value is set to a value smaller than the lower limit value MIN1 of the normal range of the second battery voltage V2. Therefore, even if the conduction path voltage V5 is lower than the lower limit value MIN1 of the normal range of the second battery voltage V2, it may be determined that the second battery 32 is not abnormal. However, since the second set value is set to a value equal to or greater than (MIN2+α) based on the lower limit value MIN2 of the drive voltage of the SBW system 20, when it is determined that the second battery 32 is not abnormal, , the SBW system 20 can operate reliably.

Note that the determination unit 341a considers detection errors and the like in the detection unit 350, and determines when the value of the conduction path voltage V5 detected by the detection unit 350 not only matches the second set value but also substantially matches the second set value. Also, it may be determined that the second battery 32 is abnormal. In this case, the determination unit 341a obtains, for example, the absolute value of the difference between the value of the conduction path voltage V5 detected by the detection unit 350 and the second set value. Then, the determination unit 341a may determine that the second battery 32 is abnormal when the obtained absolute value is equal to or less than the threshold value (in other words, when the obtained absolute value is small). The threshold is set to less than 0.2V, for example.

In step s23, when determining that the second battery 32 is abnormal, the determination unit 341a generates abnormality information 346a indicating that fact. Then, in step s23, the determination unit 341a stores the generated abnormality information 346a in the nonvolatile memory 346 of the storage unit 345. FIG.

After step s23, in step s24, the control unit 340 notifies the control unit 100 of the vehicle control device 10 that the abnormality determination has ended. At step s5, the control unit 100 instructs the SBW control unit 14 of the SBW system 20 to turn off the relay 15. FIG. The SBW control unit 14 turns off the relay 15 in step s13. As a result, the actuator 16 is no longer supplied with the conductive path voltage V5.

After step s24, the control section 340 of the power control device 34 stops the voltage output section 33 in step s25. As a result, the third voltage V3 is no longer output from the voltage output unit 33 (in other words, the third voltage V3 becomes 0 V), and the power stored in the first battery 31 is less likely to be consumed thereafter.

After step s13 is executed, when the operation unit 11 receives a start instruction operation, the vehicle control device 10 instructs the SBW control unit 14 to turn on the relay 15 . Upon receiving this instruction, the SBW control unit 14 turns on the relay 15 . Thereby, the conductive path voltage V5 is supplied to the actuator 16, and the SBW system 20 can electrically switch the shift range of the transmission 17 according to the shift range selected by the driver.

As described above, in this example, step s12 is executed before the end of the sustain period in which the value of the third voltage V3 is maintained at the first set value. Therefore, when step s25 is executed, the parking lock has already been executed. Therefore, even if the voltage output unit 33 is stopped in a state where the second battery 32 is in failure, and the conduction path voltage V5 drops below the lower limit value of the drive voltage of the SBW system 20, the vehicle 1 is safe. can maintain sexuality.

In the above example, when it is determined that the second battery 32 is abnormal in the abnormality determination, the abnormality information 346a is generated, but the abnormality information 346a does not have to be generated. In this case, the storage unit 345 does not have to include the nonvolatile memory 346 .

Also, in the above example, the abnormality determination is performed after step s21, but the abnormality determination does not have to be performed. In this case, for example, after step s21, step s25 may be executed without executing steps s22, s23, and s24.

In the above example, the relay 15 is turned off after the abnormality determination, but the relay 15 may be turned off before the abnormality determination after step s12 is executed.

As described above, in the present example, when the value of the third voltage V3 is set to the first set value, the power supply control device 34, when the vehicle 1 is instructed to stop, is stopped for a predetermined period of time. , the value of the third voltage V3 is maintained at the first set value.

On the other hand, when the voltage output unit 33 is immediately stopped in response to the stop instruction operation, if the second battery 32 is defective when the stop instruction operation is performed, the conductive path 5 There is a possibility that an appropriate voltage cannot be supplied to the electrically connected loads such as the vehicle control device 10 and the SBW system 20 .

In this example, when the stop instruction operation is performed on the vehicle 1, the value of the third voltage V3 is maintained at the first set value for a predetermined period of time. Appropriate voltage can be supplied to the load even when the second battery 32 is defective. Therefore, even if the second battery 32 fails, the load can be properly operated.

In addition, in this example, the power supply control device 34 stops the voltage output section 33 after the maintenance time has elapsed, so that the voltage output section 33 can be stopped after the load performs an operation that requires it. For example, the power control unit 34 can deactivate the voltage output 33 after the SBW system 20 included in the load has executed the parking lock. Therefore, the power stored in the first battery 31 is less likely to be consumed while appropriately operating the load.

Further, as described above, when the second battery 32 has not failed and the value of the second battery voltage V2 is higher than the second set value, the value of the conduction path voltage V5 is higher than the second set value. growing. On the other hand, when the second battery 32 has failed and the value of the second voltage V2 is equal to or less than the second battery set value, the value of the conduction path voltage V5 matches the second set value. Since the conductive path voltage V5 changes according to the presence or absence of failure of the second battery 32 in this way, it is possible to appropriately determine whether the second battery 32 is abnormal based on the conductive path voltage V5.

Further, when it is determined that the second battery 32 is abnormal and the abnormality information 346a is stored in the nonvolatile memory 346, the abnormality occurs in the second battery 32 based on the information in the nonvolatile memory 346. You can identify what you are doing. For example, the non-system device can communicate with the communication unit 360 of the power control unit 34 using CAN communication and acquire the abnormality information 346 a in the nonvolatile memory 346 through the communication unit 360 . As a result, the system-external device can identify that the second battery 32 is abnormal. The external device that has acquired the abnormality information 346a may, for example, display information indicating that the second battery 32 has an abnormality on the display unit. In this case, when the non-system device is owned by the dealer of the vehicle 1, the dealer's employee can easily recognize that the second battery 32 is abnormal.

As in the example of FIG. 4, when the voltage output unit 33 stops after the abnormality information 346a is stored in the nonvolatile memory 346, the nonvolatile memory 346 that operates based on the conductive path voltage V5 The information 346a is appropriately stored, and the power stored in the first battery 31 is less likely to be consumed.

In addition, when a system for improving the safety of the vehicle 1 (also referred to as a safety improvement system) is included in the load like the SBW system 20, processing for improving the safety of the vehicle 1 in the system (for example, By ending the maintenance time after the parking lock is performed, the safety of the vehicle 1 can be appropriately improved even if the second battery fails.

Note that the load electrically connected to the conducting path 5 is not limited to the above example. For example, loads may include safety-enhancing systems other than the SBW system 20 . For example, the load may include an electric parking brake (EPB) system as a safety enhancement system. In this case, even if the second battery 32 fails due to the EPB system operating the parking brake and mechanically maintaining the state by the end time t2 of the maintenance time T, the vehicle will 1 safety can be appropriately improved. It can be said that the parking brake executed by the EPB system is a process for improving the safety of the vehicle 1 .

In the above example, the voltage output unit 33 is a step-down DC/DC converter, but may be a step-up DC/DC converter. In this case, the value of the first battery voltage V1 is set smaller than the second set value, for example. Then, the voltage output unit 33 boosts the first battery voltage V1 and outputs it as a third voltage V3.

In the above example, the first set value is smaller than the value of the first battery voltage V1, but may be the same value as the first battery voltage V1, or may be larger than the value of the first battery voltage V1. good too. The first set value may be the same as the value of the second voltage V2 output from the second battery 32 when fully charged, or may be smaller than the value of the second voltage V2. Also, the second set value is not limited to the above example, and may be smaller than (MIN2+α), for example.

Although the determination unit 341a is provided in the power control device 34 in the above example, it may be provided in another device. For example, the determination unit 341 a may be provided in the vehicle control device 10 . In this case, the vehicle control device 10 may include the detection unit 350 or may receive the detection result of the detection unit 350 from the power supply control device 34 . Alternatively, the vehicle control device 10 may function as a device that controls the voltage output section 33 without providing the power control device 34 . In this case, at least one of the determination unit 341 a and the detection unit 350 may be provided in the vehicle control device 10 or may not be provided in the vehicle control device 10 .

Also, the vehicle 1 may be other than PHEV and EV. For example, the vehicle 1 may be a hybrid vehicle, a fuel cell vehicle, or a gasoline vehicle.

Although the in-vehicle system 2 including the power control device 34 has been described in detail as above, the above description is illustrative in all aspects, and the present disclosure is not limited thereto. Moreover, the various modifications described above can be applied in combination as long as they do not contradict each other. And it is understood that numerous variations not illustrated can be envisioned without departing from the scope of this disclosure.

Reference Signs List 1 vehicle 2 in-vehicle system 3 power supply system 4 power control device 5 conduction path 10 vehicle control device 11 operation unit 12 notification unit 13 shift selector 14 SBW control unit 15 relay 16 actuator 17 transmission 20 shift-by-wire system 25 communication line 31 first battery 32 second battery 33 voltage output section 34 power control device 100 control section 101 CPU
105 storage unit 105a program 110 communication unit 170 parking lock mechanism 340 control unit 341 CPU
341a determination unit 345 storage unit 345a program 346 nonvolatile memory 346a abnormality information 350 detection unit 360 communication unit 502, 503, 505 waveform T maintenance time V1 first voltage V2 second voltage V3 third voltage V5 conduction path voltage t1, t2, t11 time

Claims (6)

a first battery that outputs a first voltage; a second battery that outputs a second voltage to a conducting path to which a load is electrically connected; and a third battery to the conducting path based on the first voltage. A power supply control device for use in a power supply system mounted on a vehicle, comprising a voltage output unit that outputs a voltage,
A control unit that controls the voltage output unit,
When the value of the third voltage is set to the first set value, the control unit controls the operation of the vehicle for a predetermined period of time when a stop instruction operation for instructing the vehicle to stop is performed. a power control device that maintains the value of the third voltage at the first set value for a period of time. The power supply control device according to claim 1,
The power supply control device, wherein the control unit stops the voltage output unit after the predetermined time has elapsed. The power supply control device according to claim 1 or 2,
After the predetermined time has elapsed, the control unit reduces the value of the third voltage to a second set value that is smaller than the first set value,
a detection unit that detects the voltage of the conducting path;
a determination unit that determines an abnormality of the second battery based on the voltage of the conductive path detected by the detection unit when the value of the third voltage is set to the second set value; Power control unit. The power supply control device according to claim 3,
with additional non-volatile memory,
The power supply control device, wherein the determining unit stores abnormality information indicating that the second battery is abnormal in the nonvolatile memory when it is determined that the second battery is abnormal. The power supply control device according to claim 4,
the non-volatile memory operates based on the voltage of the conductive path;
The power supply control device, wherein the control unit stops the voltage output unit after the abnormality information is stored in the nonvolatile memory. The power supply control device according to any one of claims 1 to 5,
the load includes a system that enhances the safety of the vehicle;
The power supply control device, wherein the control unit terminates the predetermined time after the system performs a process for improving the safety of the vehicle.

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