JP7812634B2 - Power supply control device, power supply control method and control program - Google Patents

Description

The present invention relates to a power supply control device and a power supply control method.

Conventionally, for example, in consideration of power supply failure during autonomous operation, redundant power supply technology has been proposed that uses two power supply systems (see, for example, Patent Document 1). With this type of technology, when the current value flowing through each system exceeds a predetermined threshold, the failed system is disconnected and power is supplied from the other system.

JP 2017-61240 A

However, conventional technology leaves room for improvement in terms of detecting grid failures with high accuracy.

The present invention has been made in light of the above, and aims to provide a power supply control device and power supply control method that can detect system failures with high accuracy.

To solve the above-mentioned problems and achieve the objectives, the power supply control device of the present invention comprises a first system, a second system, a system switch, and a control unit. The first system includes a first battery and supplies power from the first battery to a load. The second system includes a second battery and supplies power from the second battery to the load. The system switch connects and disconnects the first system and the second system. When the control unit detects an overcurrent in the first system or the second system, it controls the system switch to turn off. The control unit corrects the threshold for detecting the overcurrent depending on the state of the first battery or the second battery.

The present invention makes it possible to detect system failures with high accuracy.

FIG. 1 is a diagram illustrating an example of the configuration of a power supply control device according to an embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a power supply control device according to an embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a power supply control device according to an embodiment. FIG. 4 is a diagram illustrating a method for correcting the current threshold. FIG. 5 is a diagram illustrating a power supply control device 1 according to a first modified example. FIG. 6 is a diagram illustrating a power supply control device 1 according to a second modified example. FIG. 7 is a diagram illustrating a method for correcting the voltage threshold. FIG. 8 is a diagram illustrating a power supply control device 1 according to a third modified example.

Embodiments of the power supply control device and power supply control method disclosed herein are described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below.

First, an example configuration of a power supply control device according to an embodiment will be described using Figures 1 to 3. Figures 1 to 3 are diagrams showing an example configuration of a power supply control device according to an embodiment. The power supply control device 1 according to an embodiment is a device mounted on a vehicle, and executes a power supply control method according to an embodiment.

As shown in FIG. 1, the power supply control device 1 according to the embodiment is connected to a first load 100 and a second load 200, and supplies power to each of the first load 100 and the second load 200.

The first load 100 is, for example, a load related to the forward or reverse movement of the vehicle, or a load not related to the vehicle's driving (forward or reverse movement, turning, and stopping). Loads related to the forward or reverse movement include, for example, the engine ECU (Electronic Control Unit) and the transmission ECU. Loads not related to driving include, for example, the air conditioner, windshield wipers, power windows, etc.

The second load 200 is a load related to the vehicle's turning, stopping, and autonomous driving. A load related to turning is, for example, EPS (Electric Power Steering). A load related to stopping is, for example, a brake ECU. A load related to autonomous driving is, for example, a radar, a camera, etc.

The second load 200 includes a load that allows the vehicle to perform FOP (Fail Operational) driving, such as evacuation driving, in the event of a power failure, etc.

The power supply control device 1 according to this embodiment includes a control unit 2, a high-voltage battery 3, a DC-DC converter 4, a PbB 5, an LiB 6, diodes 7 and 8, a system switch SW1, and a battery switch SW2.

Here, the power supply control device 1 includes, for example, a computer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), flash memory, input/output ports, etc., as well as various other circuits.

The computer's CPU functions as the control unit 2, for example, by reading and executing programs stored in ROM.

Furthermore, at least one or all of the functions of the control unit 2 can be configured using hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

The power supply control device 1 also has a storage unit (not shown), which corresponds to RAM or flash memory. The RAM or flash memory can store information about various programs. The power supply control device 1 may also acquire the above-mentioned programs and various information via other computers or portable recording media connected via a wired or wireless network.

The high-voltage battery 3 is a secondary battery that supplies power to the first load 100 and the second load 200. The high-voltage battery 3 is a battery with a higher voltage value than PbB5 and LiB6, which will be described later. The high-voltage battery 3, along with PbB5, which will be described later, is an example of a first battery.

The DC-DC converter 4 steps down the voltage of the high-voltage battery 3 according to the required voltage of the first load 100 or the second load 200.

PbB5 is a lead-acid battery that supplies power to the first load 100 and the second load 200. As described above, PbB5 is an example of a first battery. LiB6 is a lithium-ion battery that supplies power to the second load 200 in the event of a power failure in the first system, as described below. LiB6 is an example of a second battery.

Diodes 7 and 8 are diodes for preventing reverse current. Specifically, diode 7 has its cathode connected to the second load 200 and its anode connected to the DCDC converter 4 and PbB5. Diode 8 has its cathode connected to the second load 200 and its anode connected to the system switch SW1 and battery switch SW2.

Furthermore, below, the system that supplies power from the high-voltage battery 3 and PbB5 to the first load 100 and the second load 200 will be referred to as the first system, and the path that supplies power from the LiB6 to the second load 200 will be referred to as the second system.

As shown in FIG. 1, the first system is provided with a current sensor S1, and the second system is provided with a current sensor S2. The control unit 2, which will be described later, determines whether a power failure has occurred in each of the first and second systems based on the current values detected by the current sensors S1 and S2.

System switch SW1 is a switch that separates the first and second systems. In the event of a power failure in either the first or second system, system switch SW1 shuts off, thereby separating the first and second systems.

Battery switch SW2 is a switch that disconnects and connects LiB6 to the second system. When power to the first system fails, battery switch SW2 connects, allowing power to be supplied from LiB6 to the second load 200.

Here, an example of the operation of the power supply control device 1 will be described using Figures 1 to 3. Figure 1 shows a normal state, i.e., when there is no power failure in the first and second systems, Figure 2 shows a case where there is a power failure in the first system, and Figure 3 shows a case where there is a power failure in the second system. Note that a power failure here refers to a power failure caused by a ground fault within a system.

First, an example of the operation of the power supply control device 1 under normal conditions will be described using Figure 1. As shown in Figure 1, under normal conditions, the control unit 2 of the power supply control device 1 connects the system switch SW1 and disconnects the battery switch SW2. Under normal conditions, the current values of the current sensors S1 and S2 are each below a predetermined current threshold.

As a result, under normal conditions, power is supplied from the high-voltage battery 3 and PbB5 to the first load 100 and the second load 200 via the first system. Furthermore, power is supplied from the high-voltage battery 3 and PbB5 to the second load 200 via the second system.

Next, using Figure 2, we will explain an example of the operation of the power supply control device 1 when the first system fails. When the control unit 2 of the power supply control device 1 detects an overcurrent in the first system, it turns off the system switch SW1 and turns on the battery switch SW2. Note that an overcurrent is detected in the first system when the current value of current sensor S1 is equal to or greater than a predetermined current threshold and the current value of current sensor S2 is less than the predetermined current threshold.

As a result, in the event of a power failure in the first system, the first system is disconnected from the second load 200 and LiB6 is connected to the second load 200, allowing power to be supplied from LiB6 to the second load 200, thereby enabling FOP travel such as evacuation travel using the second load 200.

Next, using Figure 3, we will explain an example of the operation of the power supply control device 1 when the second system fails. If the control unit 2 of the power supply control device 1 detects an overcurrent in the second system, it shuts off both the system switch SW1 and the battery switch SW2. Note that an overcurrent is detected in the second system when the current value of current sensor S1 is equal to or greater than a predetermined current threshold, and the current value of current sensor S2 is equal to or greater than a predetermined current threshold.

As a result, in the event of a power failure in the second system, the second load 200 can be disconnected from the LiB 6, and by shutting off the system switch SW1, backflow from the LiB 6 to the first system can be prevented with high precision. Furthermore, by shutting off the system switch SW1, power is supplied from the high-voltage battery 3 and the PbB 5 to the first load 100 and the second load 200 via the first system.

In the event of a power failure in the second system, normal driving is possible by supplying power to both the first load 100 and the second load 200, but since power supply redundancy has been lost, it is preferable to switch to FOP driving, such as evacuation driving.

Here, in the power supply control method according to the embodiment, the current threshold used to detect an overcurrent from the current values of current sensors S1 and S2 is corrected according to the state of the first battery or the second battery.

In other words, in the power supply control method according to the embodiment, the current threshold is corrected according to the state of at least one of the high-voltage battery 3, PbB5, and LiB6. This point will be explained using Figure 4.

Figure 4 is a diagram explaining the current threshold correction method. As shown in Figure 4, a reference threshold is set in advance for the current threshold. The control unit 2 corrects the reference threshold by increasing or decreasing it depending on the state of the first battery or the second battery.

In the example shown in Figure 4, the battery status is displayed as battery temperature, remaining charge, battery deterioration over time, and whether or not there is an abnormality in the DCDC converter 4.

As shown in Figure 4, the control unit 2 corrects the reference threshold value to a higher value when the battery temperature is higher than the reference value, and corrects the reference threshold value to a lower value when the battery temperature is lower than the reference value. This is because the lower the battery temperature, the less current the battery can output.

Furthermore, as shown in Figure 4, the control unit 2 corrects the reference threshold value to a higher value when the remaining charge is greater than the reference value, and corrects the reference threshold value to a lower value when the remaining charge is less than the reference value. This is because the lower the remaining charge, the less current the battery can output.

Also, as shown in Figure 4, the control unit 2 corrects the reference threshold value to a higher value if the battery has deteriorated less than the standard value, and corrects the reference threshold value to a lower value if the battery has deteriorated more than the standard value. This is because the more advanced (greater) the battery has deteriorated, the less current it can output.

Also, as shown in Figure 4, the control unit 2 corrects the reference threshold value to a higher value if there is no abnormality in the DCDC converter 4, and corrects the reference threshold value to a lower value if there is an abnormality in the DCDC converter 4. This is because if the DCDC converter 4 stops due to an abnormality, the power supply from the high-voltage battery 3 will be cut off.

In this way, the power supply control method according to the embodiment corrects the current threshold (reference threshold) according to the state of the first or second battery, making it possible to detect overcurrents due to ground faults in the first and second systems with high accuracy. In other words, the power supply control method according to the embodiment makes it possible to detect system failures with high accuracy.

In addition, the control unit 2 can detect grid failures with greater accuracy by correcting the current threshold according to the battery's condition, such as the battery temperature, remaining charge, deterioration of the battery over time, and whether or not there is an abnormality in the DCDC converter 4.

In the example shown in Figure 4, the reference threshold is increased or decreased depending on the battery state, but the current threshold may also be corrected using a model learned through machine learning. Specifically, the correction value may be determined by inputting the battery state into a model obtained by performing machine learning using the battery state as an explanatory variable and the correction value from the reference threshold as a target variable.

Furthermore, the control unit 2 may apply the corrected current threshold to each of the two current sensors S1 and S2 as is, or may make the current threshold different for each of the two current sensors S1 and S2 based on the corrected current threshold.

Specifically, the control unit 2 may set the current threshold of the current sensor S2, which is located farther from the first battery (high-voltage battery 3 and PbB5), to be smaller than the current threshold of the current sensor S1, which is located closer to the first battery (high-voltage battery 3 and PbB5).

This is because when current flows from the first battery (high-voltage battery 3 and PbB5) to the second load 200, the current is shunted to the first load 100, etc., so the current value of current sensor S2 is smaller than the current value of current sensor S1.

The extent to which the current threshold of current sensor S2 is to be smaller than the current threshold of current sensor S1 is preferably determined based on, for example, the path length between current sensor S1 and current sensor S2, and the type, number, and resistance value of the resistors present between current sensor S1 and current sensor S2.

The control unit 2 may also measure the inrush current generated when the vehicle is started as the battery status, and correct the current threshold value according to the inrush current. Specifically, the control unit 2 measures the inrush current when the accessory power supply or ignition key is turned on using current sensors S1 and S2, and corrects the current threshold value to a value higher than the measured inrush current. This makes it possible to accurately avoid erroneous detection of a grid failure due to inrush current.

The control unit 2 may correct the current threshold based on the results of a single inrush current measurement, but it may also correct the current threshold based on the results of multiple past inrush current measurements. In such cases, the current threshold is corrected to a value higher than the average inrush current or the maximum value of the multiple past inrush current measurements.

In addition, the control unit 2 issues simulated high-load control instructions to the loads (first load 100 and second load 200) while the vehicle is parked, measures the current value flowing during high-load control using current sensors S1 and S2, and corrects the current threshold value according to the measured current value. Note that high-load control refers to control in which the power consumption of the load is equal to or greater than a predetermined value.

The control unit 2 corrects the current threshold to a value higher than the current value detected by the current sensors S1 and S2 during high-load control. This makes it possible to accurately avoid erroneous detection of a grid failure when high-load control is performed in an actual driving situation.

The control unit 2 may correct the current threshold value based on the measurement results during a single high-load control operation, but it may also correct the current threshold value based on the measurement results during multiple past high-load control operations. In such cases, the current threshold value is corrected to a value higher than the average value during high-load control or the maximum value during multiple past high-load control operations.

In addition, while the above description shows a case where the control unit 2 measures inrush current when the vehicle is started, it is also possible to measure pseudo inrush current even after the vehicle has started. This point will be explained using Figure 5.

(First Modification)
Fig. 5 is a diagram illustrating a power supply control device 1 according to a first modified example. As shown in Fig. 5, the power supply control device 1 according to the modified example further includes a first load switch SW3 that connects and disconnects a first load 100 from the first system, and a second load switch SW4 that connects and disconnects a second load 200 from the first system.

When the vehicle is parked, the control unit 2 disconnects and then connects the first load switch SW3 and the second load switch SW4, measures the current value flowing when the switches are connected using the current sensor S1, and corrects the current threshold value according to the measured current value.

In other words, by disconnecting and then connecting the first load switch SW3 and the second load switch SW4, the control unit 2 simulates a state that occurs when the vehicle is started, generating an inrush current. This increases the frequency and number of times the inrush current is measured, thereby improving the accuracy of correcting the current threshold.

As described above, the power supply control device 1 according to the embodiment includes a first system, a second system, a system switch SW1, and a control unit 2. The first system includes a first battery (high-voltage battery 3 and PbB5) and supplies power from the first battery to a load (first load 100 and second load 200). The second system includes a second battery (LiB6) and supplies power from the second battery to a load (second load 200). The system switch SW1 connects and disconnects the first system and the second system. The control unit 2 controls the system switch SW1 to shut off when an overcurrent is detected in the first system or the second system. The control unit 2 corrects the threshold for detecting an overcurrent depending on the state of the first battery or the second battery. This enables highly accurate detection of a system failure.

In the above, the control unit 2 detects an overcurrent as a power supply failure, but it may also detect a voltage drop as a power supply failure. That is, when a ground fault occurs as a power supply failure, an overcurrent flows toward the ground fault point, but at the same time, a sudden voltage drop occurs. Therefore, a ground fault can also be detected as a voltage drop rather than an overcurrent. This point will be explained using Figure 6.

(Second Modification)
Fig. 6 is a diagram illustrating a power supply control device 1 according to a second modification. As shown in Fig. 6, the power supply control device 1 according to the second modification has voltage sensors V1 and V2 instead of the current sensors S1 and S2 of Fig. 1. The voltage sensor V1 is provided in the first system and detects the voltage of the first system. The voltage sensor V2 is provided in the second system and detects the voltage of the second system.

When a ground fault occurs in the first or second system, the voltage detected by voltage sensor V1 or voltage sensor V2 drops. The control unit 2 compares the voltage value detected by voltage sensor V2 with a voltage threshold, and if the voltage value falls below the voltage threshold, it provisionally determines that a ground fault has occurred in the first or second system, shuts off system switch SW1, and connects battery switch SW2.

As a result, if a ground fault occurs in the first system, the detected voltage of voltage sensor V1 will remain below the voltage threshold, and the detected voltage of voltage sensor V2 will return to above the voltage threshold. After disconnecting system switch SW1, if the detected voltage of voltage sensor V1 remains below the voltage threshold for a predetermined period of time or longer, and the detected voltage of voltage sensor V2 returns to above the voltage threshold, the control unit 2 will determine that a ground fault has occurred in the first system and will continue to disconnect system switch SW1 and connect battery switch SW2.

As a result, in the event of a power failure (ground fault) in the first system, the first system is disconnected from the second load 200 and LiB6 is connected to the second load 200, allowing power to be supplied from LiB6 to the second load 200, thereby enabling FOP travel, such as evacuation travel, using the second load 200.

Furthermore, if a ground fault occurs in the second system, the control unit 2 will shut off the system switch SW1 and close the battery switch SW2, causing the detected voltage of the voltage sensor V2 to remain below the voltage threshold and the detected voltage of the voltage sensor V1 to return to above the voltage threshold. If, after shutting off the system switch SW1, the detected voltage of the voltage sensor V2 remains below the voltage threshold for a predetermined period of time or longer and the detected voltage of the voltage sensor V1 returns to above the voltage threshold, the control unit 2 will determine that a ground fault has occurred in the second system and will shut off the system switch SW1 and the battery switch SW2.

As a result, in the event of a power failure (ground fault) in the second system, the second load 200 can be disconnected from the LiB 6, and by shutting off the system switch SW1, backflow from the LiB 6 to the first system can be prevented with high precision. Furthermore, by shutting off the system switch SW1, power is supplied from the high-voltage battery 3 and the PbB 5 to the first load 100 and the second load 200 via the first system.

Here, in the power supply control method according to the second variant, the voltage threshold used to detect low voltage from the voltage values of voltage sensors V1 and V2 is corrected according to the state of the first battery or the second battery.

In other words, in the power supply control method according to the second modification, the voltage threshold is corrected according to the state of at least one of the high-voltage battery 3, PbB5, and LiB6. This point will be explained using Figure 7.

Figure 7 is a diagram illustrating a method for correcting the voltage threshold. As shown in Figure 7, a reference threshold is set in advance for the voltage threshold. The control unit 2 corrects the voltage threshold by increasing or decreasing the reference threshold depending on the state of the first or second battery. This correction method, similar to the current threshold correction method shown in Figure 4, uses battery temperature, remaining charge, battery deterioration over time, and the presence or absence of an abnormality in the DCDC converter 4 as battery state, and performs correction in the same way as the current threshold correction method.

In this way, the power supply control method according to the second modification can accurately detect low voltages caused by ground faults in the first and second systems by correcting the voltage threshold (reference threshold) according to the state of the first or second battery. In other words, the power supply control method according to the embodiment can accurately detect system failures.

In addition, the control unit 2 can detect grid failures with greater accuracy by correcting the voltage threshold based on the battery's condition, such as the battery temperature, remaining charge, deterioration of the battery over time, and whether or not there is an abnormality in the DCDC converter 4.

The control unit 2 may apply the corrected voltage threshold to each of the two voltage sensors V1 and V2 as is, or may make the voltage threshold different for each of the two voltage sensors V1 and V2 based on the corrected voltage threshold.

Specifically, the control unit 2 may set the voltage threshold of the voltage sensor V2 located farther away from the first battery (high-voltage battery 3 and PbB5) lower than the voltage threshold of the voltage sensor V1 located closer to the first battery (high-voltage battery 3 and PbB5).

This is because when current flows from the first battery (high-voltage battery 3 and PbB5) to the second load 200, the voltage value of voltage sensor V2 becomes smaller than the voltage value of voltage sensor V1 due to resistance losses.

The extent to which the voltage threshold of voltage sensor V2 should be smaller than the voltage threshold of voltage sensor V1 is preferably determined based on, for example, the path length between voltage sensor V1 and voltage sensor V2, and the type, number, and resistance value of the resistors present between voltage sensor V1 and voltage sensor V2.

The control unit 2 may also measure the amount of voltage drop that occurs when the vehicle is started as the battery status, and correct the voltage threshold value according to the amount of voltage drop at startup. Specifically, the control unit 2 measures the amount of voltage drop when the accessory power supply or ignition key is turned on using voltage sensors V1 and V2, and corrects the voltage threshold value to a value lower than the measured amount of voltage drop. This makes it possible to accurately avoid erroneous detection of a grid failure due to a voltage drop.

The control unit 2 may correct the voltage threshold value based on the measurement results of the amount of voltage drop at one startup, but it may also correct the voltage threshold value based on the measurement results of the amount of voltage drop at multiple previous startups. In such cases, the voltage threshold value is corrected to a value lower than the average amount of voltage drop or the maximum amount of voltage drop at multiple previous startups.

In addition, the control unit 2 issues simulated high-load control instructions to the loads (first load 100 and second load 200) while the vehicle is parked, measures the voltage value that drops during high-load control using voltage sensors V1 and V2, and corrects the voltage threshold value according to the measured voltage value. Note that high-load control refers to control in which the power consumption of the load is equal to or greater than a predetermined value.

The control unit 2 corrects the voltage threshold to a value lower than the voltage value detected by the voltage sensors V1 and V2 during high-load control. This makes it possible to accurately avoid erroneous detection of a grid failure when high-load control is performed in an actual driving situation.

The control unit 2 may correct the voltage threshold value based on the measurement results during a single high-load control operation, but it may also correct the voltage threshold value based on the measurement results during multiple past high-load control operations. In such cases, the voltage threshold value is corrected to a value lower than the average value during high-load control or the maximum value during multiple past high-load control operations.

In addition, while the above example shows the case where the control unit 2 measures the amount of voltage drop when the vehicle is started, it is also possible to measure a pseudo-voltage drop amount even after the vehicle has started. This point will be explained using Figure 8.

(Third Modification)
Fig. 8 is a diagram illustrating a power supply control device 1 according to a third modified example. As shown in Fig. 8, the power supply control device 1 according to the third modified example is configured in the same manner as in Fig. 5, except that the current sensors S1 and S2 in Fig. 5 are replaced with voltage sensors V1 and V2.

When the vehicle is parked, the control unit 2 disconnects and then connects the first load switch SW3 and second load switch SW4, measures the voltage value that drops when the switches are connected using the voltage sensor V1, and corrects the voltage threshold value based on the measured voltage value.

In other words, by first disconnecting the first load switch SW3 and the second load switch SW4 and then connecting them, the control unit 2 simulates a state that occurs when the vehicle is started, causing a voltage drop. This increases the frequency and number of times the voltage drop is measured, thereby improving the accuracy of voltage threshold correction.

(Fourth Modification)
In the above description, the control unit 2 detects an overcurrent or a voltage drop as a power supply failure. However, an overvoltage may also be detected as a power supply failure. The DC-DC converter 4 reduces the voltage of the high-voltage battery 3. However, if an abnormality occurs in the DC-DC converter 4, the DC-DC converter 4 may be unable to reduce the voltage and output the voltage of the high-voltage battery 3 as is, or may over-boost the voltage of the high-voltage battery 3 and output it. In other words, if the voltage of the first or second system reaches an overvoltage state equal to or greater than the overvoltage threshold, this indicates that an abnormality has occurred in the DC-DC converter 4. In this way, the fourth modification detects a power supply failure due to an abnormality in the DC-DC converter 4 by detecting an overvoltage. The configuration diagram of this fourth modification is the same as that shown in FIG. 6, and the method of correcting the voltage threshold is the same as that shown in FIG. 7, so detailed description will be omitted.

In variant 4, as with the second variant described above, it is also possible to correct the voltage threshold by measuring the amount of voltage drop that occurs when the vehicle is started, and to correct the voltage threshold in accordance with the measured value of the voltage drop due to simulated high-load control while the vehicle is parked.

In addition, in variant 4, voltage threshold correction similar to that in variant 3 described above can also be applied.

(Fifth Modification)
In the above example, the control unit 2 normally turns off the battery switch SW2, but as a fifth variation, the control unit 2 may normally turn on the battery switch SW2. In this case, power is normally supplied to the first load 100 and the second load 200 from both the first battery and the second battery. Therefore, even if a temporary abnormality such as a power outage occurs in one of the batteries, power can be stably supplied to the first load 100 and the second load 200.

In the fifth variant, the current threshold and voltage threshold are corrected according to the state of the battery with the higher voltage between the first and second batteries. This also enables grid failure to be detected with high accuracy.

The above-described embodiments and variations may be combined as appropriate. For example, a current sensor S1 and a voltage sensor V1 may be arranged in the first system, and a current sensor S2 and a voltage sensor V2 may be arranged in the second system.

In such cases, the control unit 2 corrects the threshold (current threshold or voltage threshold) according to the current values of the current sensors S1 and S2 or the voltage values of the voltage sensors V1 and V2.

Further advantages and modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

1 Power supply control device 2 Control unit 3 High voltage battery 4 DC-DC converter 5 PbB
6 LiB
7, 8 Diode 100 First load 200 Second load S1, S2 Current sensor SW1 System switch SW2 Battery switch SW3 First load switch SW4 Second load switches V1, V2 Voltage sensor

Claims (3)

a first system that supplies power from a first battery to a load;
a second system that supplies power from a second battery to the load;
a system switch that connects and disconnects the first system and the second system;
a control unit that performs control to shut off the system switch when a voltage drop is detected in the first system or the second system;
a load switch that connects and disconnects the load from the first system;
Equipped with
The control unit
a threshold value for detecting the voltage drop is corrected according to a state of the first battery or the second battery;
A power supply control device that connects the load switch after disconnecting it while the vehicle is parked, measures the current value that flows when the load switch is connected, or the voltage value of the first system or the second system, and corrects the threshold value according to the current value or the voltage value. a first system that supplies power from a first battery to a load;
a second system that supplies power from a second battery to the load;
a system switch that connects and disconnects the first system and the second system;
a load switch that connects and disconnects the load from the first system;
A power supply control method in which a control unit controls a power supply control device including:
When a voltage drop is detected in the first system or the second system, the system switch is turned off;
a threshold value for detecting the voltage drop is corrected according to a state of the first battery or the second battery;
By connecting the load switch after disconnecting it while the vehicle is parked, the current value flowing when the load switch is connected or the voltage value of the first system or the second system is measured, and the threshold value is corrected according to the current value or the voltage value.
Power control method. a first system that supplies power from a first battery to a load;
a second system that supplies power from a second battery to the load;
a system switch that connects and disconnects the first system and the second system;
a load switch that connects and disconnects the load from the first system;
A control program executed by a computer that controls a power supply control device comprising:
When a voltage drop is detected in the first system or the second system, the system switch is turned off;
a threshold value for detecting the voltage drop is corrected according to a state of the first battery or the second battery;
A control program that connects the load switch after disconnecting it while the vehicle is parked, measures the current value that flows when the load switch is connected, or the voltage value of the first system or the second system, and corrects the threshold value according to the current value or the voltage value.