JP2022190470A - Power supply controller and power supply control method - Google Patents

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

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

Conventionally, a main power supply and an auxiliary power supply have been provided so that even if a power failure occurs while the vehicle is running under automatic driving, the vehicle can be evacuated to a safe place and stopped. There is a redundant power supply system that supplies electric power to an onboard device (load) for automatic operation from a power supply system of an auxiliary power supply when a failure occurs (see, for example, Patent Document 1).

A vehicle equipped with a redundant power supply system is diagnosed as to whether or not the main power supply can be backed up by an auxiliary power supply.

As a method of diagnosing whether or not backup by an auxiliary power supply is possible, for example, supply the electric power required from the start of the evacuation run to the completion of the evacuation run from the auxiliary power supply to the load, and make a diagnosis based on the voltage of the auxiliary power supply that drops as a result. There is a way.

In this method, if the voltage of the auxiliary power supply that drops due to power supply to the load exceeds a predetermined threshold, it is diagnosed that backup is possible. After the vehicle has been diagnosed as capable of backing up, it is allowed to transition to autonomous driving once the auxiliary power supply has been recharged.

JP 2018-182864 A

However, the diagnostic method described above has the problem that it takes time to recharge the auxiliary power supply.

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

A power supply control device according to an aspect of an embodiment includes a diagnostic unit. The diagnostic unit causes a current smaller than the current supplied from the auxiliary power supply to the load to be supplied to the load for a predetermined period of time when the main power supply is backed up by the auxiliary power supply, and based on the voltage of the auxiliary power supply after the lapse of the predetermined period of time. to diagnose whether or not the backup is possible.

A power supply control device and a power supply control method according to an aspect of an embodiment can reduce the time required for recharging an auxiliary power supply.

FIG. 1 is an explanatory diagram illustrating a configuration example of a power control device according to an embodiment. FIG. 2 is an explanatory diagram showing an operation example of the power supply control device according to the embodiment. FIG. 3 is an explanatory diagram showing an operation example of the power supply control device according to the embodiment. FIG. 4 is an explanatory diagram showing an operation example of the power supply control device according to the embodiment. FIG. 5 is an explanatory diagram showing an operation example of the power supply control device according to the embodiment. FIG. 6 is an explanatory diagram showing an operation example of the power supply control device according to the embodiment. FIG. 7 is an explanatory diagram of a power control method according to the embodiment. 8 is a flowchart illustrating an example of a process executed by a diagnostic unit of the power control device according to the embodiment; FIG.

Embodiments of a power control device and a power control method will be described in detail below with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below. In the following, a power supply control device installed in a vehicle equipped with an automatic driving function and supplying electric power to a load will be described as an example. may be

In the following description, the vehicle in which the power control device is mounted is an electric vehicle or a hybrid vehicle, but the vehicle in which the power control device is mounted may be an internal combustion engine driven vehicle.

The power supply control device according to the embodiment may be installed in any device that includes a main power supply and an auxiliary power supply, and that backs up the main power supply with the auxiliary power supply when a power failure occurs in the main power supply.

[1. Configuration of power supply control device]
FIG. 1 is an explanatory diagram illustrating a configuration example of a power control device according to an 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 operation control device 100 . The power supply control device 1 has a first system 110 that supplies the power of the main power supply 10 to the first load 101 and the general load 102, and a second system 120 that supplies the power of the auxiliary power supply 20, which will be described later, to the second load 103. Prepare.

The first load 101 includes a load for automatic operation. For example, the first load 101 includes a steering motor, an electric brake device, an in-vehicle camera, a radar, etc. that operate during automatic driving. General loads 102 include, for example, displays, air conditioners, audio, video, and various lights.

The second load 103 has functions similar to those of the first load 101 . The second load 103 includes, for example, devices that operate during automatic 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 with power supplied from the power control device 1 . The automatic driving control device 100 is a device that operates the first load 101 or the second load 103 to control the automatic driving of the vehicle.

The main power supply 10 includes a DC/DC converter (hereinafter referred to as "DC/DC 11") and a lead battery (hereinafter referred to as "PbB 12"). The battery of the main power supply 10 may be any secondary battery other than PbB12.

DC/DC 11 is connected to a generator and a high-voltage battery having a higher voltage than PbB 12 , steps down the voltage of the generator and high-voltage battery, and outputs the voltage to first system 110 . A generator is, for example, an alternator that converts the kinetic energy of a running vehicle into electricity to generate electricity. A high-voltage battery is, for example, a battery for driving a vehicle mounted on an electric vehicle or a hybrid vehicle.

When the main power supply 10 is installed in an engine vehicle, an alternator (generator) is provided instead of the DC/DC 11 . DC/DC 11 charges PbB 12, supplies power to first load 101 and general load 102, supplies power to second load 103, and charges auxiliary power supply 20, which will be described later.

The power supply control device 1 includes an auxiliary power supply 20, an intersystem switch 41, a battery switch 42, a bypass switch 43, a control section 3, a first voltage sensor 51, a second voltage sensor 52, and a DC/DC 53. and The auxiliary power supply 20 is a backup power supply when the main power supply 10 cannot supply power. The auxiliary power supply 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). The battery of the auxiliary power supply 20 may be any secondary battery other than the LiB21.

Inter-system switch 41 is provided in inter-system line 130 that connects first system 110 and second system 120 , and is a switch capable of connecting and disconnecting first system 110 and second system 120 . The battery switch 42 is a switch capable of connecting and disconnecting the LiB 21 and the second system 120 , specifically, a switch capable of connecting and disconnecting the LiB 21 and the bypass switch 43 and the DC/DC 53 .

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

The first voltage sensor 51 is provided in the first system 110 to detect the voltage of the first system 110 and output the detection result to the control unit 3 . Second voltage sensor 52 is provided in second system 120 , detects the voltage of second system 120 , and outputs the detection result to control unit 3 .

The control unit 3 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), 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).

The control unit 3 controls the operation of the power supply control device 1 by causing the CPU to execute programs stored in the ROM using the RAM as a work area. Control unit 3 detects a ground fault in first system 110 or second system 120 based on the detection results input from first voltage sensor 51 and second voltage sensor 52 . A specific example of the ground fault detection method by the control unit 3 will be described later.

When the ground fault in the first system 110 or the second system 120 is detected, the control unit 3 notifies the automatic operation control device 100 to that effect. In addition, when the ground fault of the first system 110 or the second system 120 is detected, the control unit 3 may notify the automatic operation control device 100 that automatic operation is impossible. Moreover, when the ground fault of the 1st system|strain 110 or the 2nd system|strain 120 is not detected, the control part 3 may notify the automatic operation control apparatus 100 that an automatic operation is possible.

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, turns on the battery switch 42 and the bypass switch 43, and connects the auxiliary power supply 20 to the first system. 2 to supply power to the load 103; 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 shuts off the battery switch 42. Power is supplied to load 101 and general load 102 .

As a result, even if one of the systems has a ground fault during automatic operation, the power supply control device 1 uses the other system, and the automatic operation control device 100 makes the vehicle evacuate to a safe place and stop the vehicle. be able to.

The control unit 3 also includes a diagnosis unit 31 that diagnoses whether or not the main power supply 10 can be backed up by the auxiliary power supply 20 . A diagnostic method by the diagnostic unit 31 will be described later with reference to FIG. Next, the operation of the power control device 1 will be described with reference to FIGS. 2 to 6. FIG.

[2. Normal Operation of Power Control Device]
In a normal state when no ground fault occurs in the first system 110 and the second system 120, as shown in FIG. The switch 41 is turned on to supply power from the main power supply 10 to the first load 101 , the general load 102 and the second load 103 .

[3. Operation of Power Supply Control Device When Ground Fault Occurs]
Next, the operation of the power supply control device 1 when a ground fault occurs will be described with reference to FIGS. 3 to 5. FIG. As shown in FIG. 3 , in the power supply control device 1, for example, when a ground fault 200 occurs in the first system 110, overcurrent flows toward the ground fault point. The voltage of grid 110 falls below the ground fault threshold.

In addition, in the power supply control device 1, when the ground fault 201 occurs in the second system 120, an overcurrent flows toward the ground fault point. below the threshold.

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 less than the ground fault threshold, the control unit 3 detects an abnormality in the power supply and switches between systems. 41 is cut off, and the battery switch 42 is turned on. At this time, control unit 3 provisionally determines that a ground fault has occurred in first system 110 or second system 120 .

Thereafter, the control unit 3 determines that the voltage detected by the first voltage sensor 51 is equal to or less than the ground fault threshold for the predetermined time or more even after the predetermined time has passed, and the voltage detected by the second voltage sensor 52 is within the predetermined time. When the ground fault threshold is exceeded, it is finally determined that the ground fault 200 has occurred in the first system 110 .

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. As a result, the automatic driving control device 100 can operate the second load 103 with the electric power supplied from the auxiliary power supply 20 to evacuate the vehicle to a safe place and stop the vehicle.

Further, after the control unit 3 provisionally determines that a ground fault has occurred in the first system 110 or the second system 120, the voltage detected by the second voltage sensor 52 is equal to or less than the ground fault threshold even after a predetermined time has passed. , and when the voltage detected by the first voltage sensor 51 recovers to exceed the ground fault threshold value within a predetermined time, it is officially determined that the ground fault 201 has occurred in the second system 120 .

Then, as shown in FIG. 5, the control unit 3 shuts off the battery switch 42, supplies power from the main power supply 10 to the first load 101, and notifies the automatic operation control device 100 to that effect. As a result, the automatic driving control device 100 can operate the first load 101 with the electric power supplied from the main power supply 10 to evacuate the vehicle to a safe place and stop the vehicle.

In addition, in the power supply control device 1, when the first load 101 or the general load 102 is overloaded instead of the ground faults 200 and 201, the voltage detected by the first voltage sensor 51 is temporarily It may be below the threshold. In addition, in the power supply control device 1, when the second load 103 is overloaded, the voltage detected by the second voltage sensor 52 may temporarily fall below the ground fault threshold.

In this case, in the power supply control device 1 , power is continuously supplied from the main power supply 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 . Therefore, after the control unit 3 provisionally determines that a ground fault has occurred in the first system 110 or the second system 120, the ground fault is detected by the first voltage sensor 51 and the second voltage sensor 52 before the predetermined time elapses. If both voltages return to the level exceeding the ground fault threshold, it is determined that the voltage drop is transient and that there is no abnormality in the power supply. After that, in order to return to the normal operation shown in FIG. 2, the control unit 3 shuts off the battery switch 42 and turns on the system switch 41 again.

[4. Operation during auxiliary power supply diagnosis]
Next, with reference to FIGS. 6 and 7, the diagnostic operation of the diagnostic unit 31 of the power supply control device 1 to diagnose whether or not the main power supply 10 can be backed up by the auxiliary power supply 20 will be described.

For example, when the IG (ignition switch) of the vehicle is turned off, the diagnosis unit 31 diagnoses in the background whether or not the main power supply 10 can be backed up by the auxiliary power supply 20 the next time the IG is turned on. conduct. Note that the diagnosis unit 31 may perform diagnosis after the IG is turned on.

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

After that, the diagnosis unit 31 diagnoses whether or not the main power supply 10 can be backed up by the auxiliary power supply 20 based on the voltage of the auxiliary power supply 20 after the predetermined time has elapsed. In this embodiment, after switching to the auxiliary power supply 20, power is supplied from the auxiliary power supply 20 to the steering motor for 30 seconds to cause the vehicle to run in evacuation, and then power is supplied from the auxiliary power supply 20 to the electric brake device for 6 seconds. Backup control to stop the vehicle is assumed.

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

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

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

However, in this case, the power consumption required for the diagnosis is as large as about 0.3 [Ah], which is the same as the backup power amount when actually performing evacuation driving under backup control. takes longer.

Therefore, the diagnosis unit 31 sets a first current (for example, 10 [A ]) is supplied to the second load 103 by the control of the DC/DC 53 . After that, the diagnosis unit 31 outputs a second current (here, 6 seconds) from time t2 to time t3 as a diagnostic current, which is smaller than the actual backup control and larger than the first current ( Here, 20 [A]) is supplied to the second load 103 by the control of the DC/DC 53 .

At this time, the power consumption during diagnosis is approximately 0.1 [Ah], which is significantly reduced compared to the backup power consumption of approximately 0.3 [Ah] when the evacuation run is actually performed by backup control. be done.

Then, the diagnostic unit 31 detects the voltage of the auxiliary power supply 20 at the time t3 as the diagnostic voltage by the second voltage sensor 52 . At this time, as shown in FIG. 7, the diagnostic voltage is higher than the backup voltage during actual backup control.

For this reason, as shown in FIG. 7, the diagnostic unit 31 performs the first voltage correction and the second voltage correction on the voltage at the time of diagnosis, so that the voltage at the time of diagnosis is corrected when the backup control is actually performed. to estimate the backup voltage of

The first voltage correction is based on the voltage drop amount of the auxiliary power supply 20 when the first current of 10 [A] is supplied to the second load 103 for 30 seconds, and the backup current of 20 [A] is applied to the second load for 30 seconds. This is a process of estimating the amount of voltage drop in the auxiliary power supply 20 when the auxiliary power supply 20 is supplied to 103 .

The second voltage correction is based on the voltage drop of the auxiliary power supply 20 when the first current of 20 [A] is supplied to the second load 103 for 6 seconds, and the backup current of 80 [A] is applied to the second load for 6 seconds. This is a process of estimating the amount of voltage drop in the auxiliary power supply 20 when the auxiliary power supply 20 is supplied to 103 .

Then, if the backup voltage estimated by performing the second voltage correction exceeds a predetermined threshold value, the diagnosis unit 31 diagnoses that backup is possible. The threshold value here is set, for example, to a voltage value that is higher than the lowest voltage that can be backed up (eg, 11.5 [V]) by an estimated error margin. Further, the voltage at diagnosis and the backup voltage fluctuate according to the voltage of the auxiliary power supply 20 at the start of diagnosis.

For this reason, the diagnosis unit 31 sets, for example, a value obtained by adding an estimated error margin to the minimum voltage that can be backed up assumed when the SOC (State Of Charge) of the auxiliary power supply 20 at the start of the diagnosis is 80%, as the upper threshold limit. do. In addition, the diagnosis unit 31 sets, for example, a value obtained by adding an estimated error margin to the minimum backup-possible voltage assumed when the SOC of the auxiliary power supply 20 at the start of the diagnosis is 60%, as the lower threshold limit. Then, the diagnosis unit 31 selects a threshold value between the upper threshold value and the lower threshold value according to the SOC of the auxiliary power supply 20 at the start of the diagnosis.

In this way, the power supply control device 1 supplies the second load 103 with the first current and the second current that are smaller than the backup current supplied to the second load 103 during actual backup control, so that the auxiliary power supply 20 Diagnose whether backup is possible or not. As a result, the power supply control device 1 can reduce the power consumption during diagnosis and suppress the voltage drop of the auxiliary power supply 20 , thereby shortening the time required for recharging the auxiliary power supply 20 .

Also, the first current and the second current are set based on an assumed current supplied to the second load 103 driven when the main power supply 10 is backed up by the auxiliary power supply 20 . Thereby, the diagnosis unit 31 can estimate the correct backup voltage of the auxiliary power supply 20 when the backup control is actually performed.

Also, the first predetermined time and the second predetermined time are set based on the assumed drive time of the second load 103 that is driven when the main power supply 10 is backed up by the auxiliary power supply 20 . This also allows the diagnosis unit 31 to estimate the correct backup voltage of the auxiliary power supply 20 when the backup control is actually performed.

Further, the diagnostic unit 31 performs a third voltage correction on the backup voltage estimated by performing the second voltage correction, taking into consideration changes in temperature. Specifically, when the temperature drops, the output voltage of the LiB 21 drops according to the change in temperature.

For this reason, for example, if the IG is turned off during the day and then turned on at night or early in the morning when the temperature is lower than during the day, the voltage of the LiB 21 may be lower than the voltage during the day. be. In this case, even if the auxiliary power supply 20 was diagnosed as being capable of backup when the IG was turned off during the daytime, the next time the IG was turned on early in the morning, the auxiliary power supply 20 would be in a state where backup is not possible. There is a possibility that

Therefore, the diagnosis unit 31 performs backup 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 after the above-mentioned predetermined time (first predetermined time + second predetermined time) has elapsed. A third voltage correction for estimating the voltage of the auxiliary power supply 20 after the correction is performed.

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

Then, the diagnosis unit 31 diagnoses whether backup by the auxiliary power supply 20 is possible based on the voltage estimated by the third voltage correction (backup voltage (-15° C.) shown in FIG. 7). At this time, if the backup voltage (−15° C.) exceeds the threshold corresponding to the voltage of the auxiliary power supply 20 before diagnosis, the diagnosis unit 31 diagnoses that backup is possible.

As a result, even if the temperature drops between when the IG is turned off and when the IG is next turned on, the diagnosis unit 31 can It is possible to accurately diagnose whether or not backup by the auxiliary power supply 20 is possible.

It should be noted that each numerical value shown for the first predetermined time, the second predetermined time, the first current, the second current, the temperature, etc. described above is an example, and limits the operation of the power supply control device 1 according to the present embodiment. It can be changed arbitrarily depending on the situation.

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

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 the second current to the second load 103 for a second predetermined time (step S103), and performs a second voltage correction (step S104).

After that, the diagnosis unit 31 performs the third voltage correction on the backup voltage after the second voltage correction (step S105), and determines whether or not the voltage correction value is higher than the backup possible voltage threshold (step S106).

Then, if the diagnosis unit 31 determines that the voltage correction value is higher than the backup possible voltage threshold (step S106, Yes), the diagnosis unit 31 diagnoses that backup is possible (step S107), and ends the process. Further, when the diagnosis unit 31 determines that the voltage correction value is equal to or less than the backup possible voltage threshold (step S106, No), the diagnosis unit 31 diagnoses that backup is impossible (step S108), and ends the process.

Note that the processing shown in FIG. 8 is an example, and various modifications are possible. For example, the diagnosis unit 31 can omit the processing of the third voltage correction. For example, the diagnosis unit 31 can omit the third voltage correction in areas where the daily or annual temperature range is within a predetermined temperature range. As a result, the diagnosis unit 31 can accurately diagnose whether or not backup is possible while reducing the processing load required for the third voltage correction.

Further, the diagnosis unit 31 may omit the process of the second voltage correction and the process of the third voltage correction. In this case, for example, the diagnosis unit 31 supplies the first current to the second load 103 for a first predetermined time, and supplies the second current to the second load 103 for a second predetermined time from the voltage of the auxiliary power supply 20 that drops accordingly. The voltage of the auxiliary power supply 20 (voltage after the first voltage correction) when supplied is estimated.

Then, the diagnosis unit 31 estimates the voltage of the auxiliary power supply 20 after the second voltage correction from the estimated voltage after the first voltage correction, and estimates the voltage of the auxiliary power supply 20 after the estimated second voltage correction to the third It is also possible to estimate the voltage of the auxiliary power supply 20 after voltage correction processing.

In this case, although the diagnostic accuracy of the diagnostic unit 31 is slightly lower than that of the processing shown in FIG. 8, the processing load of steps S104 and S105 is not required, and the processing load can be reduced. Furthermore, 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, so that the time required for recharging the auxiliary power supply 20 can be further shortened.

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

1 power control device 10 main power supply 11 DC/DC
12PbB
20 auxiliary power supply 21 LiB
3 Control Unit 31 Diagnosis Unit 41 Intersystem Switch 42 Battery Switch 43 Bypass Switch 51 First Voltage Sensor 52 Second Voltage Sensor 53 DC/DC
100 Automatic Operation Control Device 101 First Load 102 General Load 103 Second Load 110 First System 120 Second System

Claims (6)

When the main power supply is backed up 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 period of time, and based on the voltage of the auxiliary power supply after the elapse of the predetermined period of time, the backup power supply is controlled. A power supply control device, comprising: a diagnosis unit that diagnoses whether or not the above is possible. The predetermined time is
including a first predetermined time and a second predetermined time that is shorter than the first predetermined time;
The diagnosis unit
After the first current is supplied 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 for the first predetermined time and the second predetermined time. The voltage of the auxiliary power supply after the backup is performed is estimated from the voltage of the auxiliary power supply after the elapse, and whether or not the backup is possible is diagnosed based on the voltage. The power control device according to . The first current and the second current are
3. The power control device according to claim 2, wherein the setting is based on an assumed current supplied to the load driven when performing the backup. The first predetermined time and the second predetermined time are
4. The power supply control device according to claim 2, wherein the setting is based on an assumed driving time of the load driven when performing the backup. The diagnosis unit
estimating the voltage of the auxiliary power supply after performing the backup when the temperature of the auxiliary power supply is lower than the current temperature by a predetermined temperature from the voltage of the auxiliary power supply after the elapse of the predetermined time; The power supply control device according to any one of claims 1 to 3, wherein it is diagnosed whether or not said backup is possible. The diagnosis part of the power control unit
When the main power supply is backed up 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 period of time, and based on the voltage of the auxiliary power supply after the elapse of the predetermined period of time, the backup power supply is controlled. diagnosing whether or not it is possible to control the power supply.

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