Power control device and power control method

Abstract

To provide a power supply controller and a power supply control method, capable of shortening time required for recharge of an auxiliary power supply.SOLUTION: A power supply controller comprises a diagnosis unit. The diagnosis unit makes current smaller than current to be supplied from an auxiliary power supply to a load in the case of backup of a main power supply by the auxiliary power supply be supplied to the load for a predetermined period time and, on the basis of voltage of the auxiliary power supply after a lapse of a predetermined time, performs diagnosis on whether or not the backup is possible. The current to be supplied to the load at the time of the diagnosis is set on the basis of assumed current to be supplied to the load that is driven at the time of the backup. The predetermined time is set on the basis of an assumed driving time of the load that is driven at the time of the backup.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The disclosed embodiments relate to a power control device and a power control method.

Background Art

[0002] Conventionally, even if a power failure occurs during driving by the automatic driving of a vehicle, the vehicle is provided with a main power source and an auxiliary power source so that it can retreat to a safe place and stop. When a failure occurs in the power supply system of the main power source, there is a redundant power supply system that supplies power to in-vehicle devices (loads) for automatic driving by the power supply system of the auxiliary power source (see, for example, Patent Document 1).

[0003] In a vehicle equipped with a redundant power supply system, a diagnosis is made as to whether the auxiliary power source can back up the main power source. If it is diagnosed that the backup is possible, the transition to automatic driving is permitted.

[0004] As a method for diagnosing whether backup by the auxiliary power source is possible, for example, there is a method of supplying power required from the start to the completion of retreat driving from the auxiliary power source to the load, and diagnosing based on the voltage of the auxiliary power source that decreases thereby.

[0005] In this method, if the voltage of the auxiliary power source that decreases due to power supply to the load exceeds a predetermined threshold value, it is diagnosed that backup is possible. After it is diagnosed that backup is possible, when the recharge of the auxiliary power source is completed, the vehicle is permitted to transition to automatic driving.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the above-described diagnostic method has a problem that it takes time to recharge the auxiliary power supply.

[0008] One aspect of the embodiment is made in view of the above, and an object thereof is to provide a power control device and a power control method capable of shortening the time required for recharging the auxiliary power supply.

Means for Solving the Problems

[0009] The power control device according to one aspect of the embodiment includes a diagnostic unit. The diagnostic unit supplies a current smaller than the current supplied from the auxiliary power supply to the load to the load for a predetermined time when the main power supply is backed up by the auxiliary power supply, and diagnoses whether the backup is possible based on the voltage of the auxiliary power supply after the elapse of the predetermined time.

Effects of the Invention

[0010] The power control device and the power control method according to one aspect of the embodiment can shorten the time required for recharging the auxiliary power supply.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

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Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the power control device and the power control method will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments shown below. Hereinafter, a power control device mounted on a vehicle having an automatic driving function and supplying power to a load will be described as an example. However, the power control device according to the embodiment may be mounted on a vehicle that does not have an automatic driving function.

[0013] In addition, hereinafter, the case where the vehicle on which the power control device is mounted is an electric vehicle or a hybrid vehicle will be described. However, the vehicle on which the power control device is mounted may be an engine vehicle that runs by an internal combustion engine.

[0014] Note that the power control device according to the embodiment includes a main power source and an auxiliary power source, and may be mounted on any device that backs up the main power source with the auxiliary power source when a power failure occurs in the main power source.

[0015] [1. Configuration of Power Control Device] FIG. 1 is an explanatory diagram showing a configuration example of the power control device according to the embodiment. As shown in FIG. 1, the power control device 1 according to the embodiment is connected to a main power source 10, a first load 101, a general load 102, a second load 103, and an automatic driving control device 100. The power control device 1 includes a first system 110 that supplies the power of the main power source 10 to the first load 101 and the general load 102, and a second system 120 that supplies the power of the auxiliary power source 20, which will be described later, to the second load 103.

[0016] The first load 101 includes loads for automatic driving. For example, the first load 101 includes a steering motor, an electric brake device, an in-vehicle camera, and a radar that operate during automatic driving. The general load 102 includes, for example, a display, an air conditioner, an audio, a video, and various lights.

[0017] The second load 103 has the same function as the first load 101. The second load 103 includes, for example, devices that operate during autonomous driving such as a steering motor, an electric brake device, an in-vehicle camera, and a radar. The first load 101, the general load 102, and the second load 103 operate by the power supplied from the power control device 1. The autonomous driving control device 100 is a device that controls the autonomous driving of the vehicle by operating the first load 101 or the second load 103.

[0018] The main power supply 10 includes a DC / DC converter (hereinafter referred to as "DC / DC11") and a lead battery (hereinafter referred to as "PbB12"). Note that the battery of the main power supply 10 may be any secondary battery other than PbB12.

[0019] DC / DC11 is connected to a generator and a high-voltage battery having a voltage higher than that of PbB12, steps down the voltages of the generator and the high-voltage battery, and outputs them to the first system 110. The generator is, for example, an alternator that generates electricity by converting the kinetic energy of a traveling vehicle into electricity. The high-voltage battery is, for example, a battery for vehicle drive mounted on an electric vehicle or a hybrid vehicle.

[0020] Note that when the main power supply 10 is mounted on an engine vehicle, an alternator (generator) is provided instead of DC / DC11. DC / DC11 performs charging of PbB12, power supply to the first load 101 and the general load 102, power supply to the second load 103, and charging of the auxiliary power supply 20 described later.

[0021] The power control device 1 includes an auxiliary power supply 20, an inter-system switch 41, a battery switch 42, a bypass switch 43, a control unit 3, a first voltage sensor 51, a second voltage sensor 52, and DC / DC53. The auxiliary power supply 20 is a backup power supply when the power supply from the main power supply 10 becomes unavailable. The auxiliary power supply 20 includes a lithium-ion battery (hereinafter referred to as "LiB21"). Note that the battery of the auxiliary power supply 20 may be any secondary battery other than LiB21.

[0022] The inter-system switch 41 is provided on the inter-system line 130 that connects the first system 110 and the second system 120, and is a switch capable of connecting and disconnecting the first system 110 and the second system 120. The battery switch 42 is a switch capable of connecting and disconnecting the LiB 21 and the second system 120. Specifically, it is a switch capable of connecting and disconnecting the LiB 21, the bypass switch 43, and the DC / DC 53.

[0023] The bypass switch 43 is a switch capable of connecting and disconnecting the battery switch 42 and the second system 120. The DC / DC 53 is connected in parallel with the bypass switch 43 and adjusts the voltage output from the LiB 21 and the voltage input to the LiB 21.

[0024] The first voltage sensor 51 is provided on the first system 110, detects the voltage of the first system 110, and outputs the detection result to the control unit 3. The second voltage sensor 52 is provided on the second system 120, detects the voltage of the second system 120, and outputs the detection result to the control unit 3.

[0025] The control unit 3 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and various circuits. Note that the control unit 3 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0026] The control unit 3 controls the operation of the power control device 1 by the CPU executing the program stored in the ROM using the RAM as a work area. The control unit 3 detects a ground fault in the first system 110 or the second system 120 based on the detection results input from the first voltage sensor 51 and the second voltage sensor 52. A specific example of the method for detecting a ground fault by the control unit 3 will be described later.

[0027] When the control unit 3 detects a ground fault in the first system 110 or the second system 120, it notifies the automatic driving control device 100 to that effect. Note that when the control unit 3 detects a ground fault in the first system 110 or the second system 120, it may notify the automatic driving control device 100 that the automatic driving is impossible. Further, when the control unit 3 does not detect a ground fault in the first system 110 or the second system 120, it may notify the automatic driving control device 100 that the automatic driving is possible.

[0028] When a power failure such as a ground fault occurs in the first system 110, the control unit 3 shuts off the inter-system switch 41, conducts the battery switch 42 and the bypass switch 43, and supplies power from the auxiliary power supply 20 to the second load 103. Also, when a power failure such as a ground fault occurs in the second system 120, the control unit 3 shuts off the inter-system switch 41 and supplies power from the main power supply 10 to the first load 101 and the general load 102 with the battery switch 42 shut off.

[0029] Thereby, even if either one of the systems has a ground fault during automatic driving, the power control device 1 can use the other system and cause the vehicle to retreat to a safe place and stop by the automatic driving control device 100.

[0030] Further, the control unit 3 includes a diagnosis unit 31 that diagnoses whether the auxiliary power supply 20 can back up the main power supply 10. The diagnosis method by the diagnosis unit 31 will be described later with reference to FIG. 7. Next, with reference to FIGS. 2 to 6, the operation of the power control device 1 will be described.

[0031] [2. Normal operation of the power control device] During normal times when no ground fault has occurred in the first system 110 and the second system 120, as shown in FIG. 2, the control unit 3 shuts off the battery switch 42, conducts the bypass switch 43, conducts the inter-system switch 41, and supplies power from the main power supply 10 to the first load 101, the general load 102, and the second load 103.

[0032] [3. Operation of the power control device when a ground fault occurs] Next, with reference to FIGS. 3 to 5, the operation of the power control device 1 when a ground fault occurs will be described. As shown in FIG. 3, in the power control device 1, for example, when a ground fault 200 occurs in the first system 110, an overcurrent flows toward the ground fault point, so that the voltage of the first system 110 detected by the first voltage sensor 51 becomes equal to or lower than the ground fault threshold value.

[0033] Also, in the power control device 1, when a ground fault 201 occurs in the second system 120, an overcurrent flows toward the ground fault point, so that the voltage of the second system 120 detected by the second voltage sensor 52 becomes equal to or lower than the ground fault threshold value.

[0034] Therefore, when the voltage detected by at least one of the first voltage sensor 51 and the second voltage sensor 52 becomes equal to or lower than the ground fault threshold value, the control unit 3 detects an abnormality in the power supply, shuts off the inter-system switch 41, and conducts the battery switch 42. At this time, the control unit 3 provisionally determines that a ground fault has occurred in the first system 110 or the second system 120.

[0035] After that, when the voltage detected by the first voltage sensor 51 remains equal to or lower than the ground fault threshold value for a predetermined time or more and the voltage detected by the second voltage sensor 52 returns above the ground fault threshold value within the predetermined time, the control unit 3 makes a final determination that a ground fault 200 has occurred in the first system 110.

[0036] Then, as shown in FIG. 4, the control unit 3 supplies power from the auxiliary power supply 20 to the second load 103 and notifies the automatic operation control device 100 to that effect. Thereby, the automatic operation control device 100 can operate the second load 103 with the power supplied from the auxiliary power supply 20, and can make the vehicle retreat to a safe place and stop.

[0037] Also, after provisionally determining that a ground fault has occurred in the first system 110 or the second system 120, when the voltage detected by the second voltage sensor 52 remains equal to or lower than the ground fault threshold value even after a predetermined time has elapsed and the voltage detected by the first voltage sensor 51 returns above the ground fault threshold value within the predetermined time, the control unit 3 makes a final determination that a ground fault 201 has occurred in the second system 120.

[0038] Then, as shown in FIG. 5, the control unit 3 shuts off the battery switch 42, supplies power from the main power source 10 to the first load 101, and notifies the automatic operation control device 100 to that effect. As a result, the automatic operation control device 100 can operate the first load 101 with the power supplied from the main power source 10, and cause the vehicle to retreat to a safe location and stop.

[0039] Also, in the power supply control device 1, when the first load 101 or the general load 102 is in an overload state rather than the ground faults 200, 201, the voltage detected by the first voltage sensor 51 may temporarily become equal to or lower than the ground fault threshold. Further, in the power supply control device 1, when the second load 103 is in an overload state, the voltage detected by the second voltage sensor 52 may temporarily become equal to or lower than the ground fault threshold.

[0040] In this case, in the power supply control device 1, power is continuously supplied from the main power source 10 to the first load 101 and the general load 102, and power is supplied from the second load 103 to the second load 103. For this reason, after the control unit 3 temporarily determines that a ground fault has occurred in the first system 110 or the second system 120, if the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 both exceed the ground fault threshold before a predetermined time elapses, it determines that this is a transient voltage drop and there is no abnormality in the power supply. Thereafter, in order to return to the normal operation shown in FIG. 2, the control unit 3 shuts off the battery switch 42 and re-conducts the inter-system switch 41.

[0041] [4. Operation during Auxiliary Power Supply Diagnosis] Next, with reference to FIGS. 6 and 7, the diagnostic operation for the diagnostic unit 31 of the power supply control device 1 to diagnose whether the auxiliary power supply 20 can back up the main power source 10 will be described.

[0042] When, for example, the vehicle's IG (ignition switch) is turned off, the diagnosis unit 31 performs a background diagnosis on whether the backup of the main power supply 10 by the auxiliary power supply 20 is possible when the IG is turned on next time. Note that the diagnosis unit 31 may perform the diagnosis after the IG is turned on.

[0043] At this time, as shown in FIG. 6, the diagnosis unit 31 turns on the battery switch 42 and turns off the bypass switch 43. Then, when the diagnosis unit 31 backs up the main power supply 10 with the auxiliary power supply 20, it supplies a diagnostic current smaller than the current (backup current) that is assumed to be supplied from the auxiliary power supply 20 to the second load 103 to the second load 103 via the DC / DC 53 for a predetermined time. The diagnosis unit 31 controls the diagnostic current value by controlling the DC / DC 53.

[0044] Thereafter, the diagnosis unit 31 diagnoses whether the backup of the main power supply 10 by the auxiliary power supply 20 is possible based on the voltage of the auxiliary power supply 20 after a predetermined time has elapsed. In the present embodiment, it is assumed that after switching to the auxiliary power supply 20, the vehicle is made to perform a retreating operation by supplying power from the auxiliary power supply 20 to the steering motor for 30 seconds, and then the vehicle is stopped by supplying power from the auxiliary power supply 20 to the electric brake device for 6 seconds.

[0045] Specifically, as shown in FIG. 7, for example, it is assumed that in order to make the vehicle perform a retreating operation for the first predetermined time (for example, 30 seconds) from time t1 to time t2, it is necessary to supply a backup current of 20 [A] to the steering motor for 30 seconds.

[0046] Also, in order to stop the vehicle in the second predetermined time (for example, 6 seconds) from time t2 to time t3, it is assumed that it is necessary to supply a backup current of 80 [A] to the electric brake device for 6 seconds.

[0047] Here, for diagnosis, if the voltage of the auxiliary power supply 20 exceeds a predetermined threshold value after actually supplying a backup current of 20 [A] from the auxiliary power supply 20 to the second load 103 for 30 seconds and then supplying a backup current of 80 [A] for 6 seconds, it can be diagnosed that backup is possible. Note that the threshold value here is set to a value higher than the lower limit value of the voltage value at which the electric brake device can operate normally.

[0048] However, in this case, the power consumption required for diagnosis becomes as large as about 0.3 [Ah], which is the same as the backup power consumption when actually performing evacuation running by backup control. Accordingly, the time required to recharge the auxiliary power supply 20 becomes longer by that amount.

[0049] Therefore, the diagnosis unit 31 supplies a first current (for example, 10 [A]), which is smaller than that in the actual backup control, as a diagnostic current to the second load 103 by controlling the DC / DC 53 for a first predetermined time (here, 30 seconds) from time t1 to time t2 during diagnosis. After that, the diagnosis unit 31 supplies a second current (here, 20 [A]), which is smaller than that in the actual backup control and larger than the first current, as a diagnostic current to the second load 103 by controlling the DC / DC 53 for a second predetermined time (here, 6 seconds) from time t2 to time t3.

[0050] At this time, the power consumption during diagnosis is about 0.1 [Ah], which is significantly reduced compared to about 0.3 [Ah], the backup power consumption when actually performing evacuation running by backup control.

[0051] Then, the diagnosis unit 31 detects, by the second voltage sensor 52, the voltage of the auxiliary power supply 20 at time t3 as the voltage during diagnosis. At this time, as shown in FIG. 7, the voltage during diagnosis becomes a voltage value higher than the backup voltage during actual backup control.

[0052] Therefore, as shown in FIG. 7, the diagnosis unit 31 estimates the backup voltage when actual backup control is performed from the voltage during diagnosis by performing a first voltage correction and a second voltage correction on the voltage during diagnosis.

[0053] The first voltage correction is a process of estimating the voltage drop amount of the auxiliary power supply 20 when a backup current of 20 [A] is supplied to the second load 103 for 30 seconds from the voltage drop amount of the auxiliary power supply 20 when a first current of 10 [A] is supplied to the second load 103 for 30 seconds.

[0054] The second voltage correction is a process of estimating the voltage drop amount of the auxiliary power supply 20 when a backup current of 80 [A] is supplied to the second load 103 for 6 seconds from the voltage drop amount of the auxiliary power supply 20 when a first current of 20 [A] is supplied to the second load 103 for 6 seconds.

[0055] Then, if the backup voltage estimated by performing the second voltage correction exceeds a predetermined threshold value, the diagnosis unit 31 diagnoses that it is backup - possible. The threshold value here is set to a voltage value higher by the amount of the estimation error margin than the backup - possible minimum voltage (for example, 11.5 [V]), for example. Also, the voltage at the time of diagnosis and the backup voltage vary according to the voltage of the auxiliary power supply 20 at the start of diagnosis.

[0056] Therefore, the diagnosis unit 31 sets, for example, a value obtained by adding the estimation error margin to the backup - possible minimum voltage assumed when the SOC (State Of Charge) of the auxiliary power supply 20 at the start of diagnosis is 80% as the upper limit of the threshold value. Also, the diagnosis unit 31 sets, for example, a value obtained by adding the estimation error margin to the backup - possible minimum voltage assumed when the SOC of the auxiliary power supply 20 at the start of diagnosis is 60% as the lower limit of the threshold value. Then, the diagnosis unit 31 selects a threshold value between the upper limit of the threshold value and the lower limit of the threshold value according to the SOC of the auxiliary power supply 20 at the start of diagnosis.

[0057] In this way, the power supply control device 1 supplies a first current and a second current, which are smaller than the backup current supplied to the second load 103 during actual backup control, to the second load 103 to diagnose whether backup by the auxiliary power supply 20 is possible. Thereby, the power supply control device 1 can reduce the power consumption during diagnosis and suppress the voltage drop of the auxiliary power supply 20, so as to shorten the time required for recharging the auxiliary power supply 20.

[0058] Also, the first current and the second current are set based on the assumed current supplied to the second load 103 that is driven when the auxiliary power supply 20 backs up the main power supply 10. Thereby, the diagnosis unit 31 can estimate the accurate backup voltage of the auxiliary power supply 20 when the backup control is actually performed.

[0059] Also, the first predetermined time and the second predetermined time are set based on the assumed driving time of the second load 103 that is driven when the auxiliary power supply 20 backs up the main power supply 10. Also by this, the diagnosis unit 31 can estimate the accurate backup voltage of the auxiliary power supply 20 when the backup control is actually performed.

[0060] Furthermore, the diagnosis unit 31 performs a third voltage correction on the backup voltage estimated by performing the second voltage correction in consideration of the change in the air temperature. Specifically, for the LiB21, when the air temperature drops, the output voltage drops according to the change in the air temperature.

[0061] For this reason, for example, when the IG is turned off during the day and then the IG is turned on at night or in the early morning when the air temperature is lower than during the day, the voltage of the LiB21 may be lower than the voltage during the day. In this case, even if the auxiliary power supply 20 was diagnosed as capable of backup when the IG was turned off during the previous day, there is a possibility that it may be in a state where backup is impossible when the IG is turned on in the early morning of the next day.

[0062] Therefore, after the lapse of the above-described predetermined time (the first predetermined time + the second predetermined time), the diagnosis unit 31 performs a third voltage correction to estimate the voltage of the auxiliary power supply 20 after backup is performed when the temperature of the auxiliary power supply 20 is lower than the current temperature by a predetermined temperature, based on the voltage of the auxiliary power supply 20.

[0063] For example, the diagnosis unit 31 estimates, by means of the third voltage correction, the voltage of the auxiliary power supply 20 (the backup voltage (-15°C) shown in FIG. 7) when the temperature of the air is 15°C lower than the current temperature, from the backup voltage estimated by performing the second voltage correction.

[0064] Then, the diagnosis unit 31 diagnoses whether backup by the auxiliary power supply 20 is possible or not, based on the voltage estimated by the third voltage correction (the backup voltage (-15°C) shown in FIG. 7). At this time, if the backup voltage (-15°C) exceeds the threshold value corresponding to the voltage of the auxiliary power supply 20 before diagnosis, the diagnosis unit 31 diagnoses that backup is possible.

[0065] Thereby, even when the temperature of the air decreases between the time when the IG is turned off and the time when the IG is next turned on, the diagnosis unit 31 can accurately diagnose whether the auxiliary power supply 20 is in a state where backup is possible when the IG is next turned on.

[0066] Note that the numerical values shown for the above-described first predetermined time, second predetermined time, first current, second current, and temperature of the air are examples, and do not limit the operation of the power supply control device 1 according to the present embodiment, and can be arbitrarily changed according to the situation.

[0067] [5. Processing executed by diagnosis unit] Next, with reference to FIG. 8, the processing executed by the diagnosis unit 31 according to the embodiment will be described. FIG. 8 is a flowchart showing an example of the processing executed by the diagnosis unit of the power supply control device according to the embodiment. When the IG of the vehicle including the power supply control device 1 is turned off, the diagnosis unit 31 starts the processing shown in FIG. 8 in the background.

[0068] Specifically, as shown in FIG. 8, the diagnosis unit 31 first supplies a first current to the second load 103 for a second predetermined time (step S101) and performs a first voltage correction (step S102). Subsequently, the diagnosis unit 31 supplies a second current to the second load 103 for a second predetermined time (step S103) and performs a second voltage correction (step S104).

[0069] Thereafter, the diagnosis unit 31 performs a third voltage correction on the backup voltage after the second voltage correction (step S105) and determines whether the voltage correction value is higher than the backup-capable voltage threshold (step S106).

[0070] When the diagnosis unit 31 determines that the voltage correction value is higher than the backup-capable voltage threshold (step S106, Yes), it diagnoses that backup is possible (step S107) and ends the process. Also, when the diagnosis unit 31 determines that the voltage correction value is equal to or lower than the backup-capable voltage threshold (step S106, No), it diagnoses that backup is impossible (step S108) and ends the process.

[0071] Note that the process shown in FIG. 8 is an example, and various modifications are possible. For example, the diagnosis unit 31 can also omit the process of the third voltage correction. For example, in a region where the daily or annual difference in temperature is within a predetermined temperature range, the diagnosis unit 31 can omit the third voltage correction. Thereby, the diagnosis unit 31 can accurately diagnose whether backup is possible while reducing the processing load required for the third voltage correction.

[0072] Also, the diagnosis unit 31 may omit the processes of the second voltage correction and the third voltage correction. In this case, the diagnosis unit 31, for example, supplies a first current to the second load 103 for a first predetermined time and estimates the voltage of the auxiliary power supply 20 when a second current is supplied to the second load 103 for a second predetermined time from the voltage of the auxiliary power supply 20 that has dropped accordingly (the voltage after the first voltage correction).

[0073] Then, the diagnosis unit 31 can estimate the voltage of the auxiliary power supply 20 after the second voltage correction from the estimated voltage after the first voltage correction, and can also estimate the voltage of the auxiliary power supply 20 after the third voltage correction process from the estimated voltage of the auxiliary power supply 20 after the second voltage correction.

[0074] In this case, although the accuracy of the diagnosis by the diagnosis unit 31 is slightly reduced compared to the process shown in FIG. 8, the processing load can be reduced because the processes of steps S104 and S105 become unnecessary. Further, the diagnosis unit 31 does not perform the process of step S103, that is, does not supply the second current to the second load 103. Therefore, the diagnosis unit 31 can further reduce the power consumption for diagnosis, and thus can further shorten the time required for recharging the auxiliary power supply 20.

[0075] Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments presented and described above. Accordingly, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Reference Numerals

[0076] 1 Power supply control device 10 Main power supply 11 DC / DC 12 PbB 20 Auxiliary power supply 21 LiB 3 Control unit 31 Diagnosis unit 41 Inter-system switch 42 Battery switch 43 Bypass switch 51 First voltage sensor 52 Second voltage sensor 53 DC / DC 100 Automatic driving control device 101 First load 102 General load 103 Second load 110 First system 120 Second system

Claims

1. When performing backup of the main power supply by the auxiliary power supply, a current smaller than the current supplied from the auxiliary power supply to the load is supplied to the load for a predetermined time, and from the voltage of the auxiliary power supply after the lapse of the predetermined time, the voltage of the auxiliary power supply after performing the backup is estimated, and based on the estimated voltage, a control unit that diagnoses whether the backup is possible A power supply control device comprising the same.

2. The predetermined time Includes a first predetermined time and a second predetermined time shorter than the first predetermined time, The control unit After supplying a first current to the load for the first predetermined time, a second current larger than the first current is supplied to the load for the second predetermined time, and from the voltage of the auxiliary power supply after the lapse of the first predetermined time and the second predetermined time, the voltage of the auxiliary power supply after performing the backup is estimated, and based on the voltage, it is diagnosed whether the backup is possible The power supply control device according to claim 1.

3. The first current and the second current Are set based on an assumed current supplied to the load driven when performing the backup The power supply control device according to claim 2.

4. The first predetermined time and the second predetermined time Are set based on an assumed driving time of the load driven when performing the backup The power supply control device according to claim 2 or claim 3.

5. The control unit From the voltage of the auxiliary power supply after the lapse of the predetermined time, when the temperature of the auxiliary power supply is lower than the current temperature by a predetermined temperature, the voltage of the auxiliary power supply after performing the backup is estimated, and based on the voltage, it is diagnosed whether the backup is possible The power supply control device according to any one of claims 1 to 3.

6. When performing backup of the main power supply by an auxiliary power supply, a current smaller than the current supplied from the auxiliary power supply to a load is supplied to the load for a predetermined time, and based on the voltage of the auxiliary power supply after the elapse of the predetermined time, the voltage of the auxiliary power supply after performing the backup is estimated, and based on the estimated voltage, it is diagnosed whether the backup is possible. A power supply control method performed by a control device.

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