JP2023043533A - Power supply control unit - Google Patents

Abstract

To provide a power supply control unit that, when ground fault really occurs, can prevent a delay in fail-safe control.SOLUTION: A power supply control unit 1 comprises: a first system 110 that supplies power of a first power supply 10 to a first load 101; a second system 120 that supplies power of a second power supply 20 to a second load 103; an inter-system switch 41 that can connect the first system and the second system to each other and cut off the systems from each other; a first detection unit 31 that detects an abnormality in the first system or the second system based on a physical quantity indicating the state of the first system or the second system and a first threshold; and a second detection unit 32 that identifies whether the system in which the abnormality is detected by the first detection unit is the first system or the second system with a longer time than the time of detection performed by the first detection unit based on the physical quantity and a second threshold that is set to increase the sensitivity to detect an abnormality compared with the first threshold, and makes a transition to fail-safe control.SELECTED DRAWING: Figure 1

Description

The disclosed embodiments relate to power control devices.

A first system that supplies power from a first power supply to a first load, a second system that supplies power from a second power supply to a second load, and an inter-system switch capable of connecting and disconnecting the first system and the second system There is a power control device with

When the hardware detects a ground fault in the first system or the second system, the power control device shuts off the switch between systems, and then uses software to identify whether the system in which the ground fault was detected is the first system or the second system. and shift to fail-safe control (see Patent Document 1, for example).

JP 2019-62727 A

However, ground fault detection by software takes a longer determination time than ground fault detection by hardware. Therefore, when a ground fault actually occurs, fail-safe control is delayed.

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 capable of preventing a delay in fail-safe control when a ground fault actually occurs.

A power supply control device according to an aspect of an embodiment includes a first system, a second system, an inter-system switch, a first detector, and a second detector. The first system supplies power from the first power supply to the first load. The second system supplies power from the second power supply to the second load. An inter-system switch is capable of connecting and disconnecting the first system and the second system. The first detection unit detects an abnormality in the first system or the second system based on a physical quantity indicating the state of the first system or the second system and a first threshold value. The second detection unit sets whether the system in which the abnormality is detected by the first detection unit is the first system or the second system so that sensitivity for detecting abnormality is higher than the physical quantity and the first threshold. Based on the second threshold value that is determined, it takes a longer time than the detection time by the first detection unit to specify, and shifts to fail-safe control.

The power supply control device according to one aspect of the embodiment has the effect of being able to prevent delays in fail-safe control when a ground fault actually occurs.

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 of the first threshold and the second threshold according to the embodiment. FIG. 7 is an explanatory diagram illustrating a configuration example of a switch driving unit according to the embodiment; 8 is a flowchart illustrating an example of processing executed by a switch driving unit 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.

Note that the power supply control device according to the embodiment includes a first power supply and a second power supply, and when a power supply failure occurs in either one of the first power supply and the second power supply system, the other power supply system may be installed in any device that backs up the first power supply by

[1. Configuration of power 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 first 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 includes a first system 110 that supplies power from a first power supply 10 to a first load 101 and a general load 102, and a second system 120 that supplies power from a second power supply 20, which will be described later, to a second load 103. and

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

The second load 103 has part of the functions for automatic operation that the first load 101 has. For example, the second load 103 includes devices such as a steering motor, an electric brake device, and a radar that are minimally necessary for FOP (fail-safe control). 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 for controlling automatic driving of a vehicle. The automatic driving control device 100 operates the first load 101 and the second load 103 to drive the vehicle by automatic driving. Further, the automatic operation control device 100 can perform FOP by the second load 103 when a ground fault occurs in the first system 110 during automatic operation, and when a ground fault occurs in the second system 120 , the FOP can be implemented by the first load 101 .

The first power supply 10 includes a DC/DC converter (hereinafter referred to as "DC/DC11") and a lead battery (hereinafter referred to as "PbB12"). The battery of the first 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 first power supply 10 is installed in an engine vehicle, an alternator (generator) is provided instead of the DC/DC 11 . The DC/DC 11 charges the PbB 12, supplies power to the first load 101 and the general load 102, supplies power to the second load 103, and charges the second power supply 20, which will be described later.

The power supply control device 1 includes a second power supply 20 , an intersystem switch 41 , a battery switch 42 , a switch driving section 3 , a first voltage sensor 51 and a second voltage sensor 52 . The second power supply 20 is a backup power supply when the first power supply 10 cannot supply power. The second power source 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). The battery of the second power supply 20 may be any secondary battery other than 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 that connects the second power supply 20 to the second system 120 . In the following description, connecting the inter-system switch 41 means electrically connecting the first system 110 and the second system 120, that is, making them conductive. Further, disconnecting the inter-system switch 41 means disconnecting, that is, disconnecting the electrical connection between the first system 110 and the second system 120 .

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

The switch driving 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 switch driving unit 3 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

The switch drive unit 3 includes a first detection unit 31 and a second detection unit 32 that function when the CPU executes a program stored in the ROM using the RAM as a work area. controls the behavior of Note that the first detection unit 31 may be configured by hardware.

First detection unit 31 detects an abnormality in first system 110 or second system 120 based on a physical quantity indicating the state of first system 110 or second system 120 and a first threshold. A case where the physical quantity according to the embodiment is voltage will be described below. Moreover, below, the case where the abnormality which concerns on embodiment is a ground fault is demonstrated.

Note that the physical quantity according to the embodiment is not limited to voltage, and may be a physical quantity other than voltage, such as current or temperature. Moreover, the abnormality according to the embodiment is not limited to the ground fault, and may be other abnormality other than the ground fault, such as an abnormal overcurrent state or an abnormal high temperature state. A case where the physical quantity is other than the voltage and the case where the abnormality is other than the ground fault will be described later.

The second detection unit 32 determines whether the system in which the abnormality is detected by the first detection unit 31 is the first system 110 or the second system 120, the physical quantity indicating the state of the first system 110 or the second system 120, and the first threshold. Based on the second threshold value that is set so that the sensitivity for detecting an abnormality is higher than that of the first detection unit 31, it is specified over a longer period of time than the detection time by the first detection unit 31, and the process shifts to fail-safe control. As a result, the power supply control device 1 can prevent a delay in the fail-safe control when a ground fault actually occurs.

A specific configuration example of the switch drive unit 3 will be described later with reference to FIG. When activated, the switch drive unit 3 connects (turns on) the intersystem switch 41 and cuts off (turns off) the battery switch 42 . Switch drive unit 3 detects a ground fault in first system 110 or second system 120 based on detection results input from first voltage sensor 51 and second voltage sensor 52 . A specific example of a ground fault detection method by the switch drive unit 3 will be described later.

When the switch drive unit 3 detects a ground fault in the first system 110 or the second system 120, it notifies the automatic operation control device 100 to that effect. When detecting a ground fault in the first system 110 or the second system 120, the switch drive unit 3 outputs an automatic operation prohibition signal to the automatic operation control device 100 indicating that the automatic operation is disabled. In addition, when the switch drive unit 3 does not detect a ground fault in the first system 110 or the second system 120, it outputs an automatic operation permission signal indicating that automatic operation is possible to the automatic operation control device 100. do.

When a power failure such as a ground fault occurs in the first system 110, the switch drive unit 3 shuts off the inter-system switch 41, connects the battery switch 42, and switches from the second power supply 20 to the second load. 103 is powered. Further, when a power failure such as a ground fault occurs in the second system 120, the switch drive unit 3 shuts off the inter-system switch 41 and shuts off the battery switch 42. Power is supplied to the first load 101 and the 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 performs FOP in which the vehicle is evacuated to a safe place. can be parked. Next, the operation of the power control device 1 will be described with reference to FIGS. 2 to 5. FIG.

[2. Normal Operation of Power Control Device]
As shown in FIG. 2, the switch drive unit 3 shuts off the battery switch 42 and connects the inter-system switch 41 when the first system 110 and the second system 120 are not grounded. Power is supplied from the first power source 10 to the first load 101 , the general load 102 and the second load 103 . The switch drive unit 3 outputs an automatic operation permission signal to the automatic operation control device 100 during normal times when no ground fault occurs.

[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 or when a ground fault 201 occurs in the second system 120, an overload is directed toward the ground fault point. Since the current flows, the voltage detected by the first voltage sensor 51 and the second voltage sensor 52 becomes equal to or less than the ground fault determination threshold.

For this reason, when the first detection unit 31 of the switch driving unit 3 detects, for example, by hardware that the voltage detected by the second voltage sensor 52 has become equal to or lower than the first threshold, which is the ground fault determination threshold, , the first system 110 or the second system 120 is tentatively determined to have ground faults 200 and 201 .

When the first detection unit 31 provisionally determines that the ground faults 200 and 201 have occurred, the switch driving unit 3 outputs an automatic operation prohibition signal to the automatic operation control device 100 and immediately shuts off the inter-system switch 41. , the battery switch 42 is connected. As a result, the connection between the first system 110 and the second system 120 is cut, power is supplied from the first power supply 10 to the first system 110 , and power is supplied from the second power supply 20 to the second system 120 .

Note that first detection unit 31 detects first system 110 or second system 120 when the voltage detected by at least one of first voltage sensor 51 and second voltage sensor 52 becomes equal to or less than the first threshold. It is also possible to provisionally determine that a ground fault has occurred in

After that, the second detection unit 32 of the switch driving unit 3 determines whether the system in which the ground fault has been detected is the first system 110 or the second system 120 by detecting the voltage detected by the first voltage sensor 51 and the second voltage sensor 52 . and the second threshold.

The second threshold is set to have a higher sensitivity for detecting an abnormality than the first threshold. Specifically, it is set to a value higher than the second threshold by a predetermined voltage. Then, the second detection unit 32 identifies the system in which the ground fault occurred over a period of time longer than the ground fault detection time by the first detection unit 31, and shifts to fail-safe control.

At this time, the second detection unit 32 detects that the voltage detected by the first voltage sensor 51 is equal to or less than the second threshold for a predetermined time or longer, and the voltage detected by the second voltage sensor 52 exceeds the second threshold within the predetermined time. If the ground fault 200 has occurred in the first system 110, it is officially determined that the ground fault 200 has occurred.

In this case, as shown in FIG. 4 , the second detection unit 32 transitions to fail-safe control, and the second power supply 20 is switched while maintaining the cut-off state of the inter-system switch 41 and the connected state of the battery switch 42 . , supplies power 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 second power supply 20 to make the vehicle evacuate to a safe place and stop the vehicle. In addition, the automatic operation control device 100 may be configured to start evacuation traveling when an automatic operation prohibition signal is input from the power supply control device 1 .

Further, after the first detection unit 31 provisionally determines that a ground fault has occurred in the first system 110 or the second system 120, the second detection unit 32 detects the ground fault with the second voltage sensor 52 even after a predetermined time has passed. When the voltage detected by the first voltage sensor 51 is equal to or lower than the second threshold and the voltage detected by the first voltage sensor 51 returns to exceed the second threshold within a predetermined time, it is determined that the ground fault 201 has occurred in the second system 120. do.

In this case, as shown in FIG. 5 , the second detection unit 32 shifts to fail-safe control, shuts off the battery switch 42 while continuing the shut-off state of the inter-system switch 41 , and turns off the first power supply 10 . , supplies power 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 first power supply 10 to make the vehicle evacuate to a safe place and stop the vehicle. In addition, the automatic operation control device 100 may be configured to start evacuation traveling when an automatic operation prohibition signal is input from the power supply control device 1 .

In this way, the second detection unit 32 compares the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52 with the second threshold higher than the first threshold, thereby detecting the ground level. Identify the involved system and shift to fail-safe control. As a result, the power supply control device 1 can prevent a delay in the fail-safe control when a ground fault actually occurs.

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

In this case, in the power supply control device 1 , power is continuously supplied from the first power supply 10 to the first load 101 and the general load 102 , and power is supplied from the second power supply 20 to the second load 103 . Therefore, switch drive unit 3 temporarily determines that ground faults 200 and 201 have occurred in first system 110 or second system 120, and then switches first voltage sensor 51 and second voltage sensor 51 before a predetermined time elapses. If the voltages detected by 52 both return to exceed the ground fault determination threshold value, it is determined that there is no abnormality in the power supply due to a transient voltage drop. Thereafter, the switch drive unit 3 shuts off the battery switch 42 and reconnects the system switch 41 in order to return to the normal operation shown in FIG.

[4. Explanation of first threshold and second threshold]
FIG. 6 is an explanatory diagram of the first threshold and the second threshold according to the embodiment. As shown in FIG. 6, in the power supply control device 1, for example, when a ground fault or an overload condition occurs, the voltage detected by the first detection unit 31 (the voltage of the first system 110 or the voltage of the second system 120) drops. do. The first detector 31 determines that an abnormality has occurred when the detected voltage drops to the first threshold at time t1.

At this time, even if the second detection unit 32 detects the voltage of the first system 110 or the voltage of the second system 120, for example, due to individual differences, the voltage is exactly the same as that of the first detection unit 31. may not be detected. In other words, voltage detection errors may occur in the second detector 32 .

Here, when the first detection unit 31 detects an abnormality at time t1, the second detection unit 32 detects a voltage higher than the voltage detected by the first detection unit 31 (see the dotted line on the high voltage side shown in FIG. 6). is detected, an erroneous determination may occur if the same first threshold value as that of the first detection unit 31 is used.

Specifically, the second detection unit 32 performs the abnormality determination from the time t1 when the first detection unit 31 determines that there is an abnormality to the time t2. is detected, the detected voltage does not drop to the first threshold value, so it is erroneously determined that there is no abnormality at time t2.

Therefore, for example, if the determination period is extended to time t3, the second detection section 32 can determine that an abnormality has occurred at time t3, like the first detection section 31 does. However, if the second detection section 32 sets the determination period to be long, the transition to the fail-safe control is delayed.

Therefore, the second detection unit 32 sets the second threshold based on the detected value of the physical quantity detected by the second detection unit 32 when the first detection unit 31 detects an abnormality. At this time, the second detection unit 32 sets, for example, the second threshold used as the ground fault determination threshold higher than the first threshold (for example, +0.5 V).

For example, the second detection unit 32 shuts off the inter-system switch 41 in a situation that does not hinder the running of the vehicle, such as before shipment of the power supply control device 1 or while the vehicle is stopped after being mounted on the vehicle. Thus, by lowering the voltage of the second system 120, a ground fault condition is intentionally generated in the second system.

Then, when the first detection unit 31 detects a ground fault, the second detection unit 32 acquires the detected voltage of the second voltage sensor 52, and adds a predetermined voltage to the acquired voltage (for example, +0.5 V). The value obtained is set as the second threshold.

Thereby, the second detection unit 32 can set an appropriate second threshold that can accurately detect a ground fault even when there is an error between the detected voltage and the detected voltage of the first detection unit 31 . Furthermore, in the case shown in FIG. 6, the second detection unit 32 can determine that an abnormality has occurred at time t2 without extending the determination period. Therefore, the power supply control device 1 can prevent the fail-sale control from being sent while reliably detecting the ground fault.

[5. Configuration example of switch driving unit according to embodiment]
Next, a configuration example of the switch driving section 3 according to the embodiment will be described with reference to FIG. FIG. 7 is an explanatory diagram showing a configuration example of the switch driving section 3 according to the embodiment.

As shown in FIG. 7, the switch driver 3 includes a first detector 31, a second detector 32, an OR logic circuit 33, and an OR logic circuit . The voltage detection result of the first system 110 is input from the first voltage sensor 51 to the first detection unit 31 and the second detection unit 32, and the voltage detection result of the second system 120 is input from the second voltage sensor 52. be done.

When the first detection unit 31 detects a ground fault in the first system 110 or the second system 120, the inter-system switch 41 is cut off and the battery switch 42 is turned on. Specifically, when the voltage of the first system 110 or the voltage of the second system 120 becomes equal to or less than the first threshold, the first detection unit 31 detects the second detection unit 32, the OR logic circuit 33, and the OR logic circuit 34 to output a primary ground fault detection signal. At this time, the first detection unit 31 outputs, for example, a 50 ms one-shot pulse signal as the primary ground fault detection signal. When the primary ground fault detection signal is input from the first detection section 31 , the second detection section 32 outputs a secondary ground fault detection signal to the OR logic circuit 33 and the OR logic circuit 34 .

The OR logic circuit 34 outputs the primary ground fault detection signal from the first detection unit 31 or the secondary ground fault detection signal from the second detection unit 32 to the inter-system switch 41 as a cutoff signal, so that the inter-system switch 41 is blocked. The OR logic circuit 33 outputs the primary ground fault detection signal from the first detection unit 31 or the secondary ground fault detection signal from the second detection unit 32 as a connection signal to the battery switch 42, whereby the battery switch 42 is connected.

Therefore, when a ground fault occurs in the first system 110 or the second system 120, the first detection unit 31 instantly detects the ground fault, cuts off the inter-system switch 41 via the OR logic circuit 34, and A battery switch 42 is connected via circuit 33 .

After a short delay, the second detection unit 32 keeps the system switch 41 disconnected via the OR logic circuit 34 and keeps the battery switch 42 connected via the OR logic circuit 33 . Further, when the primary ground fault detection signal is input from the first detection unit 31 , the second detection unit 32 outputs an automatic operation prohibition signal to the automatic operation control device 100 .

Further, when the ground fault is detected by the first detection unit 31, the second detection unit 32 specifies whether the system in which the ground fault is detected is the first system 110 or the second system 120, and the ground fault is eliminated. If so, the system-to-system switch 41 is reconnected and the battery switch 42 is cut off.

Specifically, when detecting the primary ground fault detection signal output from the first detection unit 31, the second detection unit 32 reduces the voltage of the first system 110 and the second system 120 for a predetermined period of time. to sample. Then, the second detection unit 32 identifies the system in which the voltage below the second threshold is continuously sampled for a predetermined time (for example, 40 ms) as the system in which the ground fault has been detected.

Further, when the first system 110 and the second system 120 continuously sample the voltage exceeding the second threshold for a predetermined time (for example, 40 ms), the second detection unit 32 determines that the ground fault does not continue. , and the OR logic circuit 34 to output a connection signal (a signal of the opposite logic to the secondary ground fault detection signal). When the connection signal is input from the second detection unit 32 , the OR logic circuit 34 outputs the connection signal to the inter-system switch 41 to reconnect the inter-system switch 41 . At this time, the second detection unit 32 outputs an automatic operation permission signal to the automatic operation control device 100 and outputs a control signal to the battery switch 42 via the OR logic circuit 33 to shut off the battery switch 42 .

[6. Processing executed by the switch driving unit]
Next, processing executed by the switch drive unit 3 of the power supply control device 1 will be described with reference to FIG. FIG. 8 is a flow chart showing an example of processing executed by the switch drive unit 3 of the power control device 1 according to the embodiment. The switch drive unit 3 repeatedly executes the processing shown in FIG. 8 during normal operation.

Specifically, as shown in FIG. 8, the switch drive unit 3 first detects an abnormality (for example, ground fault) based on the physical quantity (for example, voltage) of the first system 110 or the second system 120 and the first threshold. ) is detected (step S101).

When the switch drive unit 3 determines that no abnormality is detected (step S101, No), it ends the process and restarts the process from step S101. When the switch drive unit 3 determines that an abnormality has been detected (step S101, Yes), it shuts off the inter-system switch 41 and turns on the battery switch 42 (step S102).

After that, the switch driving unit 3 determines whether or not the system in which the abnormality is detected has been identified based on the second threshold value that is higher in sensitivity than the first threshold value (step S103). When the switch drive unit 3 determines that the system in which the abnormality is detected has been identified (step S103, Yes), that is, when it is determined that an abnormality has occurred, the switch driving unit 3 shifts to fail-safe control (step S104) and performs processing. exit.

For example, when the switch drive unit 3 makes a final determination that the ground fault 200 has occurred in the first system 110, the system switch 41 is cut off and the battery switch 42 is turned on. It shifts to fail-safe control to supply power to the load 103 . Further, when the switch drive unit 3 determines that the ground fault 201 has occurred in the second system 120, the switch drive unit 3 switches the first power supply 10 to the first load 101 and the first load 101 and It shifts to fail-safe control to supply power to the general load 102 .

Further, when the switch drive unit 3 determines that the system in which the abnormality is detected cannot be identified (step S103, No), that is, when it is determined that the abnormality does not occur, the switch driving unit 3 turns on the inter-system switch 41. , the battery switch 42 is cut off to return to normal operation. After that, the switch driving section 3 restarts the processing from step S101.

[7. Modification]
The power supply control device 1 is configured to acquire a current value as a physical quantity indicating the state of the first system 110 or the second system 120, and determine an abnormality in the first system 110 or the second system 120 based on the current value. may

In this case, the power supply control device 1 includes a first current sensor that detects the value of the current flowing through the first system 110 and outputs the detection result to the switch drive unit 3, and detects the value of the current that flows through the second system 120 and switches A second current sensor that outputs a detection result to the drive unit 3 is further provided.

When the current value detected by the first current sensor or the second current sensor exceeds the first threshold, the first detection unit 31 detects occurrence of an overcurrent abnormality and shuts off the inter-system switch 41 . The second detection unit 32 sets a value lower than the first threshold as the second threshold.

For example, the second detection unit 32 operates the DC/DC 11 in a situation that does not hinder the running of the vehicle, such as before shipment of the power supply control device 1 or while the vehicle is stopped after being mounted on the vehicle. The current flowing through the first system 110 and the second system 120 is increased. Then, when the first detection unit 31 detects an overcurrent abnormality, the second detection unit 32 obtains the current value detected by the first detection unit 31, and obtains a value obtained by subtracting a predetermined value from the obtained current value. 2 is set as a threshold.

Then, the second detection unit 32 determines whether the system in which the overcurrent abnormality is detected by the first detection unit 31 is the first system 110 or the second system 120, based on the current detected by the first current sensor or the second current sensor. Based on the value and the second threshold value, it takes longer than the detection time by the first detection unit 31 to specify, and shift to fail-safe control. As a result, the power supply control device 1 can prevent the fail-safe control from being delayed when an overcurrent abnormality actually occurs.

Further, the power supply control device 1 is configured to acquire the temperature as a physical quantity indicating the state of the first system 110 or the second system 120, and determine abnormality of the first system 110 or the second system 120 based on the temperature. may

In this case, the first power supply 10 includes a first temperature sensor that detects the temperature of the PbB 12 and outputs it to the switch driving section 3 . The second power supply 20 includes a second temperature sensor that detects the temperature of the LiB 21 and outputs it to the switch driving section 3 .

When the temperature detected by the first temperature sensor or the second temperature sensor exceeds the first threshold value, the first detection unit 31 detects occurrence of an excessive temperature rise abnormality and shuts off the inter-system switch 41 . The second detection unit 32 sets a value lower than the first threshold as the second threshold.

For example, the second detection unit 32 heats the first power supply 10 or the second power supply 20 by using a heating device such as a heater before the power supply control device 1 is shipped. Then, the second detection unit 32 acquires the temperature of the first detection unit 31 when the first detection unit 31 detects an overheating abnormality, and subtracts a predetermined value from the acquired temperature to obtain the second threshold value. set as

Then, the second detection unit 32 detects, by the first temperature sensor or the second temperature sensor, whether the system in which the excessive temperature rise abnormality is detected by the first detection unit 31 is the first system 110 or the second system 120. Based on the temperature and the second threshold value, it takes longer than the detection time of the first detection unit 31 to specify, and shifts to fail-safe control. As a result, the power supply control device 1 can prevent the fail-safe control from being delayed when the excessive temperature rise abnormality actually occurs.

Power supply control device 1 may be configured to determine an overvoltage abnormality in first system 110 or second system 120 based on the voltage value of first system 110 or second system 120 .

In this case, when the voltage value detected by the first voltage sensor 51 or the second voltage sensor 52 exceeds the first threshold, the first detection unit 31 detects the occurrence of the overvoltage abnormality and shuts off the inter-system switch 41. do. The second detection unit 32 sets a value lower than the first threshold as the second threshold.

For example, the second detection unit 32 operates the DC/DC 11 in a situation that does not hinder the running of the vehicle, such as before shipment of the power supply control device 1 or while the vehicle is stopped after being mounted on the vehicle. The voltages of system 110 and second system 120 are increased. Then, when the first detection unit 31 detects an overvoltage abnormality, the second detection unit 32 acquires the detected voltage value of the first detection unit 31, subtracts a predetermined value from the acquired current value, Set as a threshold.

Then, the second detection unit 32 detects whether the system in which the overvoltage abnormality is detected by the first detection unit 31 is the first system 110 or the second system 120 by the first voltage sensor 51 or the second voltage sensor 52. Based on the voltage value and the second threshold value, it takes longer than the detection time by the first detection unit 31 to specify, and shift to fail-safe control. As a result, the power supply control device 1 can prevent the fail-safe control from being delayed when the overvoltage abnormality actually occurs.

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 supply control device 10 first power supply 11 DC/DC
12PbB
20 second power supply 21 LiB
3 switch drive unit 31 first detection unit 32 second detection unit 33 OR logic circuit 34 OR logic circuit 41 inter-system switch 42 battery switch 51 first voltage sensor 52 second voltage sensor 100 automatic operation control device 101 first load 102 General load 103 Second load 110 First system 120 Second system

Claims (5)

a first system that supplies power from the first power supply to the first load;
a second system that supplies power from the second power supply to the second load;
an inter-system switch capable of connecting and disconnecting the first system and the second system;
a first detection unit that detects an abnormality in the first system or the second system based on a first threshold value and a physical quantity indicating the state of the first system or the second system;
A second threshold value that is set such that the sensitivity for detecting an abnormality is higher than the physical quantity and the first threshold value, and determines whether the system in which the abnormality is detected by the first detection unit is the first system or the second system. and a second detection unit that takes a longer time than the detection time of the first detection unit to specify based on the above, and shifts to fail-safe control. the physical quantity is a voltage value,
The second detection unit is
The power control device according to claim 1, wherein the second threshold is set to a value higher than the first threshold. the physical quantity is a current value,
The second detection unit is
The power supply control device according to claim 1, wherein the second threshold is set to a value lower than the first threshold. the physical quantity is temperature;
The second detection unit is
The power supply control device according to claim 1, wherein the second threshold is set to a value lower than the first threshold. The second detection unit is
The second threshold is set based on the detected value of the physical quantity detected by the second detection unit when the abnormality is detected by the first detection unit. 1. The power control device according to claim 1.

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