Power control unit

Abstract

To provide a power supply control device capable of preventing delay in fail-safe control when a ground fault occurs.SOLUTION: A power supply control device includes a first system, a second system, an inter-system switch, a first detection unit, and a second detection unit. The first system supplies power from a first power source to a first load, and the second system supplies power from a second power source to a second load. The inter-system switch can connect and disconnect the first system and the second system. The first detection unit detects an abnormality in the first system or the second system on the basis of a physical quantity indicating the state of the first system or the second system and a first threshold value, and when an abnormality is detected, shuts off the inter-system switch. The second detection unit determines whether the system in which the abnormality is detected by the first detection unit is the first system or the second system on the basis of the physical quantity and a second threshold value set to have higher sensitivity for detecting abnormalities than the first threshold value, taking a longer time than the detection time of the first detection unit, and transitions to fail-safe control while maintaining the inter-system switch in a shut-off state.SELECTED DRAWING: Figure 1

Description

Technical Field

[0007]

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

Background Art

[0002] There is a power control device including a first system that supplies power of a first power source to a first load, a second system that supplies power of a second power source to a second load, and an inter-system switch capable of connecting and disconnecting the first system and the second system.

[0003] When the power control device detects a ground fault in the first system or the second system by hardware, it cuts off the inter-system switch, and then identifies whether the system in which the ground fault is detected is the first system or the second system by software and shifts to fail-safe control (see, for example, Patent Document 1).

Prior Art Documents

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029] [[ID=A power control device according to one embodiment comprises a first system, a second system, an inter-system switch, a first detection unit, and a second detection unit. The first system supplies power from a first power source to a first load. The second system supplies power from a second power source to a second load. The inter-system switch can connect and disconnect 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. When it detects the occurrence of an abnormality, it shuts off the inter-system switch. The second detection unit determines whether the system in which the first detection unit detected an abnormality is the first system or the second system, based on the physical quantity and a second threshold value set to have a higher sensitivity for detecting abnormalities than the first threshold value, over a period of time longer than the detection time by the first detection unit. It then transitions to fail-safe control while maintaining the shut-off state of the inter-system switch. [Effects of the Invention]

[0008] A power control device according to one embodiment has the effect of preventing a delay in fail-safe control in the event that a ground fault actually occurs. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is an explanatory diagram showing an example of the configuration of a power supply control device according to an embodiment. [Figure 2] Figure 2 is an explanatory diagram showing an example of operation of the power control device according to the embodiment. [Figure 3] Figure 3 is an explanatory diagram showing an example of operation of the power control device according to the embodiment. [Figure 4] Figure 4 is an explanatory diagram showing an example of operation of the power control device according to the embodiment. [Figure 5] Figure 5 is an explanatory diagram showing an example of operation of the power control device according to the embodiment. [Figure 6] Figure 6 is an explanatory diagram of the first and second thresholds according to the embodiment. [Figure 7] Figure 7 is an explanatory diagram showing an example of the configuration of a switch drive unit according to an embodiment. [Figure 8] Figure 8 is a flowchart showing an example of the process performed by the switch drive unit according to the embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the power control device and power control method will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments shown below. In the following description, a power control device that is mounted on a vehicle equipped with an autonomous driving function and supplies power to a load will be used as an example, but the power control device according to the embodiment may be mounted on a vehicle that is not equipped with an autonomous driving function.

[0011] Furthermore, the following description will focus on the case where the vehicle equipped with the power control device is an electric vehicle or a hybrid vehicle, but the vehicle equipped with the power control device may also be an engine-powered vehicle that runs on an internal combustion engine.

[0012] The power control device according to this embodiment may be mounted on any device that includes a first power supply and a second power supply, and backs up the first power supply with the other power supply system in the event of a power failure in either the first or second power supply system.

[0013] [1. Configuration of the power control unit] Figure 1 is an explanatory diagram showing an example configuration of a power control device according to an embodiment. As shown in Figure 1, the power control device 1 according to the embodiment is connected to a first power supply 10, a first load 101, a general load 102, a second load 103, and an automatic operation control device 100. The power control device 1 includes a first system 110 that supplies power from the first power supply 10 to the first load 101 and the general load 102, and a second system 120 that supplies power from a second power supply 20 (described later) to the second load 103.

[0014] The first load 101 includes loads for autonomous driving. For example, the first load 101 includes a steering motor, an electric brake device, and an in-vehicle camera that operate during autonomous driving. The general load 102 includes, for example, a display, an air conditioner, an audio system, a video system, and various lights.

[0015] The second load 103 includes a part of the functions for autonomous driving provided by the first load 101. For example, the second load 103 includes devices that are minimally necessary for FOP (fail-safe control) of a steering motor, an electric brake device, and a radar. The first load 101, the general load 102, and the second load 103 operate with the power supplied from the power control device 1.

[0016] The autonomous driving control device 100 is a device that controls the autonomous driving of the vehicle. The autonomous driving control device 100 causes the vehicle to travel by autonomous driving by operating the first load 101 and the second load 103. Further, when a ground fault occurs in the first system 110 during autonomous driving, the autonomous driving control device 100 can perform FOP by the second load 103, and when a ground fault occurs in the second system 120, the autonomous driving control device 100 can perform FOP by the first load 101.

[0017] The first power source 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 source 10 may be any secondary battery other than PbB12.

[0018] DC / DC11 is connected to a generator and a high-voltage battery having a voltage higher than that of PbB12, and steps down the voltages of the generator and the high-voltage battery and outputs them to the first system 110. The generator is, for example, an alternator that generates electricity by converting the kinetic energy of a traveling vehicle into electricity. The high-voltage battery is, for example, a vehicle drive battery mounted on an electric vehicle or a hybrid vehicle.

[0019] In addition, when the first power source 10 is mounted on 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 source 20 described later.

[0020] The power supply control device 1 includes a second power source 20, an inter-system switch 41, a battery switch 42, a switch drive unit 3, a first voltage sensor 51, and a second voltage sensor 52. The second power source 20 is a backup power source when the power supply by the first power source 10 becomes unavailable. The second power source 20 includes a lithium-ion battery (hereinafter referred to as "LiB 21"). Note that the battery of the second power source 20 may be any secondary battery other than LiB 21.

[0021] The inter-system switch 41 is provided on an inter-system line 130 connecting the first system 110 and the second system 120, and is a switch capable of connecting and disconnecting the first system 110 and the second system 120. The battery switch 42 is a switch that connects the second power source 20 to the second system 120. In the following description, connecting the inter-system switch 41 means electrically connecting, that is, conducting, the first system 110 and the second system 120. Also, disconnecting the inter-system switch 41 means disconnecting, that is, interrupting, the electrical connection between the first system 110 and the second system 120.

[0022]

[0023] I The first voltage sensor 51 is provided on the first system 110, detects the voltage of the first system 110, and outputs the detection result to the switch drive unit 3. The second voltage sensor 52 is provided on the second system 120, detects the voltage of the second system 120, and outputs the detection result to the switch drive unitThe switch drive unit 3 includes a microcomputer with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and various circuits. The switch drive unit 3 may also be composed of hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0024] The switch drive unit 3 includes a first detection unit 31 and a second detection unit 32, which function by the CPU executing a program stored in ROM using RAM as a working area, and controls the operation of the power control device 1. The first detection unit 31 may be configured as hardware.

[0025] The first detection unit 31 detects an abnormality in the first system 110 or the second system 120 based on a physical quantity indicating the state of the first system 110 or the second system 120 and a first threshold value. The following describes the case where the physical quantity according to the embodiment is voltage. The following also describes the case where the abnormality according to the embodiment is a ground fault.

[0026] The physical quantity in the embodiment is not limited to voltage, but may be other physical quantities such as current or temperature. Furthermore, the abnormality in the embodiment is not limited to a ground fault, but may be other abnormalities such as an abnormal overcurrent or abnormal high temperature. Cases where the physical quantity is other than voltage and cases where the abnormality is other than a ground fault will be described later.

[0027] The second detection unit 32 determines whether the system in which the first detection unit 31 detected an abnormality is the first system 110 or the second system 120, based on a physical quantity indicating the state of the first system 110 or the second system 120 and a second threshold set to have a higher sensitivity for detecting abnormalities than the first threshold, taking a longer time than the detection time of the first detection unit 31, and then transitions to fail-safe control. This prevents the power control device 1 from delaying fail-safe control if a ground fault has actually occurred.

[0028] A specific configuration example of the switch drive unit 3 will be described later with reference to Figure 7. When activated, the switch drive unit 3 connects (turns on) the inter-system switch 41 and disconnects (turns off) the battery switch 42. Based on the detection results input from the first voltage sensor 51 and the second voltage sensor 52, the switch drive unit 3 detects a ground fault in the first system 110 or the second system 120. A specific example of the ground fault detection method by the switch drive unit 3 will be described later.

[0029] If 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 of this fact. If the switch drive unit 3 detects a ground fault in the first system 110 or the second system 120, it outputs an automatic operation prohibition signal to the automatic operation control device 100 indicating that automatic operation is not possible. If 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 to the automatic operation control device 100 indicating that automatic operation is possible.

[0030] If 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 supplies power from the second power source 20 to the second load 103. Also, if 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 the battery switch 42, and supplies power from the first power source 10 to the first load 101 and the general load 102.

[0031] As a result, even if one of the power systems experiences a ground fault during automatic driving, the power control device 1 can use the other system and implement a Forward Operation (FOP) using the automatic driving control device 100 to move the vehicle to a safe location and bring it to a stop. Next, the operation of the power control device 1 will be explained with reference to Figures 2 to 5.

[0032] [2. Normal operation of the power control device] When no ground faults occur in the first system 110 and the second system 120, the switch drive unit 3, as shown in Figure 2, shuts off the battery switch 42 and connects the inter-system switch 41 to supply power from the first power supply 10 to the first load 101, the general load 102, and the second load 103. When no ground faults occur in this manner, the switch drive unit 3 outputs an automatic operation permission signal to the automatic operation control device 100.

[0033] [3. Operation of the power control device in the event of a ground fault] Next, the operation of the power control device 1 during a ground fault will be explained with reference to Figures 3 to 5. As shown in Figure 3, in the power control device 1, for example, if a ground fault 200 occurs in the first system 110, or if a ground fault 201 occurs in the second system 120, an overcurrent flows toward the ground fault point, causing the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 to fall below the ground fault detection threshold.

[0034] Therefore, the first detection unit 31 of the switch drive unit 3, for example, if the voltage detected by the second voltage sensor 52 falls below the first threshold, which is the ground fault determination threshold, the hardware detects that a ground fault 200 or 201 has occurred in the first system 110 or the second system 120.

[0035] Then, when the first detection unit 31 provisionally determines that ground faults 200 and 201 have occurred, the switch drive unit 3 outputs an automatic operation prohibition signal to the automatic operation control device 100, immediately shuts off the inter-system switch 41, and connects the battery switch 42. As a result, the connection between the first system 110 and the second system 120 is severed, 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.

[0036] Furthermore, the first detection unit 31 can also provisionally determine that a ground fault has occurred in the first system 110 or the second system 120 when the voltage detected by at least one of the first voltage sensor 51 or the second voltage sensor 52 falls below a first threshold.

[0037] Subsequently, the second detection unit 32 of the switch drive unit 3 determines whether the system in which the ground fault was detected is the first system 110 or the second system 120, based on the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52, and the second threshold value.

[0038] The second threshold is set to have a higher sensitivity for detecting abnormalities than the first threshold. Specifically, it is set to a value that is a predetermined voltage higher than the second threshold. The second detection unit 32 then identifies the system in which the ground fault occurred after a longer period of time than the ground fault detection time by the first detection unit 31, and transitions to fail-safe control.

[0039] At this time, the second detection unit 32 determines that a ground fault 200 has occurred in the first system 110 if the voltage detected by the first voltage sensor 51 remains below the second threshold for a predetermined period of time or longer, and the voltage detected by the second voltage sensor 52 recovers to exceed the second threshold within a predetermined period of time.

[0040] In this case, as shown in Figure 4, the second detection unit 32 switches to fail-safe control and supplies power from the second power supply 20 to the second load 103 while maintaining the disconnected state of the inter-system switch 41 and the connected state of the battery switch 42, and notifies the automatic driving control device 100 of this. As a result, the automatic driving control device 100 operates the second load 103 with the power supplied from the second power supply 20, causing the vehicle to move to a safe location and stop. The automatic driving control device 100 may also be configured to start moving to a safe location when an automatic driving prohibition signal is input from the power supply control device 1.

[0041] Furthermore, after the first detection unit 31 has made a provisional determination that a ground fault has occurred in the first system 110 or the second system 120, if the voltage detected by the second voltage sensor 52 remains below the second threshold even after a predetermined time has elapsed, and the voltage detected by the first voltage sensor 51 recovers to exceed the second threshold within a predetermined time, the second detection unit 32 makes a final determination that a ground fault 201 has occurred in the second system 120.

[0042] In this case, as shown in Figure 5, the second detection unit 32 switches to fail-safe control, keeping the inter-system switch 41 in the off state, and then shuts off the battery switch 42 to supply power from the first power supply 10 to the first load 101, and notifies the automatic driving control device 100 of this. As a result, the automatic driving control device 100 operates the first load 101 with the power supplied from the first power supply 10, causing the vehicle to move to a safe location and stop. The automatic driving control device 100 may also be configured to start moving to a safe location when an automatic driving prohibition signal is input from the power supply control device 1.

[0043] In this way, the second detection unit 32 identifies the faulty system by comparing the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52 with a second threshold that is higher than the first threshold, and then switches to fail-safe control. This prevents the power supply control device 1 from delaying the fail-safe control if a ground fault has actually occurred.

[0044] In addition, in the power control device 1, the voltage detected by the first voltage sensor 51 may temporarily fall below the ground fault detection threshold if the first load 101 or the general load 102 is temporarily overloaded, rather than due to ground faults 200 or 201. Also, in the power control device 1, the voltage detected by the second voltage sensor 52 may temporarily fall below the ground fault detection threshold if the second load 103 is temporarily overloaded.

[0045] In this case, the power control device 1 continuously supplies power 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, after the switch drive unit 3 provisionally determines that a ground fault 200,201 has occurred in the first system 110 or the second system 120, if the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 both recover to exceed the ground fault detection threshold before a predetermined time has elapsed, it makes a final determination that it was a transient voltage drop and there is no abnormality in the power supply. After that, the switch drive unit 3 disconnects the battery switch 42 and reconnects the inter-system switch 41 in order to return to the normal operation shown in Figure 2.

[0046] [4. Explanation of the first and second thresholds] Figure 6 is an explanatory diagram of the first and second thresholds according to the embodiment. As shown in Figure 6, in the power control device 1, for example, when a ground fault or overload condition occurs, the detected voltage by the first detection unit 31 (voltage of the first system 110 or voltage of the second system 120) decreases. The first detection unit 31 determines that an abnormality has occurred when the detected voltage drops to the first threshold at time t1.

[0047] In this case, even if the second detection unit 32 detects the voltage of the first system 110 or the voltage of the second system 120, it may not detect the exact same voltage as the first detection unit 31 due to, for example, individual differences. In other words, voltage detection errors may occur in the second detection unit 32.

[0048] Here, if 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 Figure 6) when the first detection unit 31 detects an abnormality at time t1, using the same first threshold value as the first detection unit 31 may lead to a misjudgment.

[0049] Specifically, the second detection unit 32 performs an abnormality determination from time t1, which was determined to be abnormal by the first detection unit 31, to time t2. However, if it detects the voltage shown by the dotted line on the high-voltage side in Figure 6, the detected voltage will not drop to the first threshold, and therefore it will incorrectly determine that there is no abnormality at time t2.

[0050] Therefore, if the second detection unit 32 extends the judgment period to time t3, for example, it can determine that an abnormality has occurred at time t3, just like the first detection unit 31. However, if the second detection unit 32 sets a longer judgment period, the transition to fail-safe control will be delayed.

[0051] Therefore, when the first detection unit 31 detects an abnormality, the second detection unit 32 sets a second threshold value based on the detected value of the physical quantity detected by the second detection unit 32. At this time, the second detection unit 32 sets the second threshold value, which is used as the ground fault determination threshold, higher than the first threshold value (for example, +0.5V).

[0052] For example, the second detection unit 32 intentionally causes a ground fault in the second system by lowering the voltage of the second system 120, such as by shutting off the inter-system switch 41, when the power control device 1 is not shipped or when the vehicle is stopped after being installed in the vehicle, in a situation that does not interfere with the vehicle's operation.

[0053] Then, when the first detection unit 31 detects a ground fault, the second detection unit 32 acquires the detected voltage from the second voltage sensor 52 and sets the acquired voltage plus a predetermined voltage (for example, +0.5V) as the second threshold value.

[0054] As a result, the second detection unit 32 can set an appropriate second threshold that accurately detects a ground fault even if there is an error between the detected voltage and the detected voltage of the first detection unit 31. Furthermore, in the case shown in Figure 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 reliably detect a ground fault while suppressing delays in fail-sail control.

[0055] [5. Example of switch drive unit configuration according to the embodiment] Next, with reference to Figure 7, an example of the configuration of the switch drive unit 3 according to the embodiment will be described. Figure 7 is an explanatory diagram showing an example of the configuration of the switch drive unit 3 according to the embodiment.

[0056] As shown in Figure 7, the switch drive unit 3 includes a first detection unit 31, a second detection unit 32, an OR logic circuit 33, and an OR logic circuit 34. The first detection unit 31 and the second detection unit 32 receive the voltage detection result of the first system 110 from the first voltage sensor 51 and the voltage detection result of the second system 120 from the second voltage sensor 52.

[0057] When the first detection unit 31 detects a ground fault in the first system 110 or the second system 120, it shuts off the inter-system switch 41 and turns on the battery switch 42. Specifically, when the voltage of the first system 110 or the voltage of the second system 120 falls below a first threshold, the first detection unit 31 outputs a primary ground fault detection signal to the second detection unit 32, the OR logic circuit 33, and the OR logic circuit 34. At this time, the first detection unit 31 outputs, for example, a 50ms one-shot pulse signal as the primary ground fault detection signal. When the first detection unit 31 inputs the primary ground fault detection signal to the second detection unit 32, it outputs a secondary ground fault detection signal to the OR logic circuit 33 and the OR logic circuit 34.

[0058] The OR logic circuit 34 shuts off the inter-system switch 41 by outputting 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 shut-off signal to the inter-system switch 41. The OR logic circuit 33 connects the battery switch 42 by outputting 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.

[0059] 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 and shuts off the inter-system switch 41 via the OR logic circuit 34, while simultaneously connecting the battery switch 42 via the OR logic circuit 33.

[0060] A short delay, the second detection unit 32 maintains the inter-system switch 41 in the off state via the OR logic circuit 34, and maintains the battery switch 42 in the connected state via the OR logic circuit 33. Furthermore, when the second detection unit 32 receives a primary ground fault detection signal from the first detection unit 31, it outputs an automatic operation prohibition signal to the automatic operation control device 100.

[0061] Furthermore, when the first detection unit 31 detects a ground fault, the second detection unit 32 identifies whether the system where the ground fault was detected is the first system 110 or the second system 120. If the ground fault has been resolved, it performs a recovery control by reconnecting the inter-system switch 41 and shutting off the battery switch 42.

[0062] Specifically, when the second detection unit 32 detects a primary ground fault detection signal output from the first detection unit 31, it samples the voltages of the first system 110 and the second system 120 at predetermined intervals for a predetermined period. The second detection unit 32 then identifies the system from which it has continuously sampled a voltage below the second threshold for a predetermined time (for example, 40 ms) or longer as the system from which a ground fault has been detected.

[0063] Furthermore, if the second detection unit 32 samples voltages exceeding the second threshold for a predetermined time (for example, 40 ms) or longer in both the first system 110 and the second system 120, it determines that the ground fault is not continuing and outputs a connection signal (a signal with the inverse logic of the secondary ground fault detection signal) to the OR logic circuit 34. When the OR logic circuit 34 receives the connection signal from the second detection unit 32, it outputs the connection signal to the inter-system switch 41 and reconnects 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.

[0064] [6. Processes executed by the switch drive unit] Next, the process performed by the switch drive unit 3 of the power control device 1 will be described with reference to Figure 8. Figure 8 is a flowchart showing an example of the process performed by the switch drive unit 3 of the power control device 1 according to this embodiment. The switch drive unit 3 repeatedly performs the process shown in Figure 8 during normal operation.

[0065] Specifically, as shown in Figure 8, the switch drive unit 3 first determines whether or not an abnormality (e.g., the occurrence of a ground fault) has been detected based on a physical quantity (e.g., voltage) of the first system 110 or the second system 120 and a first threshold value (step S101).

[0066] If the switch drive unit 3 determines that it has not detected an abnormality (step S101, No), it terminates the process and restarts the process from step S101. If the switch drive unit 3 determines that it has detected an abnormality (step S101, Yes), it shuts off the inter-system switch 41 and opens the battery switch 42 (step S102).

[0067] Subsequently, the switch drive unit 3 determines whether it was able to identify the system in which the abnormality was detected based on a second threshold that is more sensitive than the first threshold (step S103). If the switch drive unit 3 determines that it was able to identify the system in which the abnormality was detected (step S103, Yes), that is, if it has determined that an abnormality has occurred, it transitions to fail-safe control (step S104) and terminates the process.

[0068] For example, if the switch drive unit 3 determines that a ground fault 200 has occurred in the first system 110, it switches to fail-safe control, which supplies power from the second power supply 20 to the second load 103 while keeping the inter-system switch 41 shut off and the battery switch 42 conductive. Also, if the switch drive unit 3 determines that a ground fault 201 has occurred in the second system 120, it switches to fail-safe control, which supplies power from the first power supply 10 to the first load 101 and the general load 102 while keeping the inter-system switch 41 and the battery switch 42 shut off.

[0069] Furthermore, if the switch drive unit 3 determines that it could not identify the system in which an abnormality was detected (step S103, No), that is, if it determines that no abnormality has occurred, it conducts the inter-system switch 41 and disconnects the battery switch 42 (step S105) to return to normal operation. After that, the switch drive unit 3 starts processing again from step S101.

[0070] [7. Variant] The power control device 1 may be configured to acquire a current value as a physical quantity indicating the state of the first system 110 or the second system 120, and to determine an abnormality in the first system 110 or the second system 120 based on the current value.

[0071] In this case, the power control device 1 further includes a first current sensor that detects the current value flowing through the first system 110 and outputs the detection result to the switch drive unit 3, and a second current sensor that detects the current value flowing through the second system 120 and outputs the detection result to the switch drive unit 3.

[0072] The first detection unit 31 detects the occurrence of an overcurrent abnormality when the current value detected by the first current sensor or the second current sensor exceeds the first threshold, and shuts off the inter-system switch 41. The second detection unit 32 sets a second threshold value lower than the first threshold.

[0073] For example, the second detection unit 32 operates the DC / DC converter 11 to increase the current flowing to the first system 110 and the second system 120 in situations that do not interfere with the vehicle's operation, such as before the power control device 1 is shipped or while the vehicle is stopped after being installed. When the first detection unit 31 detects an overcurrent abnormality, the second detection unit 32 acquires the detected current value from the first detection unit 31 and sets a value obtained by subtracting a predetermined value from the acquired current value as the second threshold value.

[0074] Then, the second detection unit 32 determines whether the system in which the overcurrent abnormality was detected by the first detection unit 31 is the first system 110 or the second system 120, based on the current value detected by the first current sensor or the second current sensor and the second threshold, taking a longer time than the detection time by the first detection unit 31, and then transitions to fail-safe control. This prevents the power supply control device 1 from delaying the fail-safe control in the event that an overcurrent abnormality has actually occurred.

[0075] Furthermore, the power control device 1 may be configured to acquire temperature as a physical quantity indicating the state of the first system 110 or the second system 120, and to determine an abnormality in the first system 110 or the second system 120 based on the temperature.

[0076] 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 drive unit 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 drive unit 3.

[0077] The first detection unit 31 detects the occurrence of an overheating anomaly when the temperature detected by the first or second temperature sensor exceeds the first threshold, and shuts off the inter-system switch 41. The second detection unit 32 sets a second threshold value lower than the first threshold.

[0078] For example, before shipping the power control device 1, the second detection unit 32 heats the first power supply 10 or the second power supply 20 using a heating device such as a heater to raise its temperature. Then, when the first detection unit 31 detects an overheating abnormality, the second detection unit 32 acquires the temperature of the first detection unit 31 and sets a value obtained by subtracting a predetermined value from the acquired temperature as the second threshold.

[0079] Then, the second detection unit 32 determines whether the system in which the first detection unit 31 detected an overheating anomaly is the first system 110 or the second system 120, based on the temperature detected by the first or second temperature sensor and the second threshold, taking a longer time than the detection time by the first detection unit 31, and then transitions to fail-safe control. This prevents the power control device 1 from delaying the fail-safe control if an overheating anomaly has actually occurred.

[0080] Furthermore, the power control device 1 may be configured to determine an overvoltage abnormality in the first system 110 or the second system 120 based on the voltage value of the first system 110 or the second system 120.

[0081] In this case, the first detection unit 31 detects the occurrence of an overvoltage abnormality when the voltage value detected by the first voltage sensor 51 or the second voltage sensor 52 exceeds the first threshold, 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.

[0082] For example, the second detection unit 32 operates the DC / DC converter 11 to increase the voltage of the first system 110 and the second system 120 in situations that do not interfere with the vehicle's operation, such as before the power control device 1 is shipped or while the vehicle is stopped after being installed. When the first detection unit 31 detects an overvoltage abnormality, the second detection unit 32 acquires the voltage value detected by the first detection unit 31 and sets a value obtained by subtracting a predetermined value from the acquired current value as the second threshold.

[0083] Then, the second detection unit 32 determines whether the system in which the overvoltage abnormality was detected by the first detection unit 31 is the first system 110 or the second system 120, based on the voltage value detected by the first voltage sensor 51 or the second voltage sensor 52 and the second threshold, taking a longer time than the detection time by the first detection unit 31, and then transitions to fail-safe control. This prevents the power supply control device 1 from delaying the fail-safe control in the event that an overvoltage abnormality has actually occurred.

[0084] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0085] 1 Power supply control device 10 1st power supply 11 DC / DC 12 PbB 20 2nd power supply 21 LiB 3. Switch drive unit 31 First detection unit 32 Second detection unit 33 OR Logic Circuits 34 OR Logic Circuits 41 Inter-system switches 42 Battery Switch 51. First voltage sensor 52 Second Voltage Sensor 100 Automatic Driving Control System 101 1st load 102 General load 103 2nd load 110 1st system 120 2nd system

Claims

1. A first system that supplies power from the first power source to the first load, A second system that supplies power from the second power source to the second load, A system-to-system switch that can connect and disconnect the first system and the second system, A first detection unit detects an abnormality in the first or second system based on a physical quantity indicating the state of the first or second system and a first threshold value, and when an abnormality is detected, it shuts off the inter-system switch. The second detection unit determines whether the system in which the first detection unit has detected an abnormality is the first system or the second system, based on the physical quantity and a second threshold set to have a higher sensitivity for detecting abnormalities than the first threshold, over a period of time longer than the detection time of the first detection unit, and then transitions to fail-safe control while maintaining the disconnected state of the inter-system switch. A power control device equipped with the following features.

2. A first system that supplies power from the first power source to the first load, A second system that supplies power from the second power source to the second load, A system-to-system switch that can connect and disconnect the first system and the second system, A battery switch that can connect and disconnect the second power supply to the second system, With the inter-system switch connected and the battery switch disconnected, 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, and when an abnormality is detected, it disconnects the inter-system switch and connects the battery switch. The second detection unit determines whether the system in which the first detection unit has detected an abnormality is the first system or the second system, based on the physical quantity and a second threshold set to have a higher sensitivity for detecting abnormalities than the first threshold, over a period of time longer than the detection time by the first detection unit, and if the abnormal system is the first system, it transitions to fail-safe control while maintaining the disconnected state of the inter-system switch and the connected state of the battery switch. A power control device equipped with the following features.

3. A first system that supplies power from the first power source to the first load, A second system that supplies power from the second power source to the second load, A system-to-system switch that can connect and disconnect the first system and the second system, A battery switch that can connect and disconnect the second power supply to the second system, With the inter-system switch connected and the battery switch disconnected, 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, and when an abnormality is detected, it disconnects the inter-system switch and connects the battery switch. The second detection unit determines whether the system in which the first detection unit has detected an abnormality is the first system or the second system, based on the physical quantity and a second threshold set to have a higher sensitivity for detecting abnormalities than the first threshold, over a period of time longer than the detection time by the first detection unit. If the abnormal system is the second system, the second detection unit continues the disconnected state of the inter-system switch and disconnects the battery switch, thereby transitioning to fail-safe control. A power control device equipped with the following features.

4. If the second detection unit determines that no abnormality has occurred, it performs a recovery control to connect the inter-system switch. A power control device according to any one of claims 1 to 3.

5. A power supply control device that supplies power to a load installed on a vehicle, The aforementioned fail-safe control is a control that causes the vehicle to move to an escape route. A power control device according to any one of claims 1 to 4.

6. A first system that supplies power from the first power source to the first load, A second system that supplies power from the second power source to the second load, A system-to-system switch that can connect and disconnect the first system and the second system, A first detection unit performs a preliminary determination of whether an abnormality has occurred in the first or second system based on a physical quantity indicating the state of the first or second system and a first threshold value, and if it is preliminary determined that an abnormality has occurred, it shuts off the inter-system switch. After the first detection unit has made a preliminary determination that an abnormality has occurred, the second detection unit makes a final determination of the occurrence of an abnormality based on the physical quantity and a second threshold set to have a higher sensitivity for detecting abnormalities than the first threshold, taking a longer time than the detection time by the first detection unit, and if it makes a final determination that no abnormality has occurred, the second detection unit performs a return control to connect the inter-system switch. A power control device equipped with the following features.

7. A first system that supplies power from the first power source to the first load, A second system that supplies power from the second power source to the second load, A system-to-system switch that can connect and disconnect the first system and the second system, A battery switch that can connect and disconnect the second power supply to the second system, With the inter-system switch connected and the battery switch disconnected, the first detection unit makes a preliminary determination of whether an abnormality has occurred 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, and if it is preliminary determined that an abnormality has occurred, it disconnects the inter-system switch and connects the battery switch. After the first detection unit has made a preliminary determination that an abnormality has occurred, the second detection unit makes a final determination of the occurrence of an abnormality based on the physical quantity and a second threshold set to have a higher sensitivity for detecting abnormalities than the first threshold, taking a longer time than the detection time by the first detection unit. If the second detection unit makes a final determination that no abnormality has occurred, it connects the inter-system switch and disconnects the battery switch. A power control device equipped with the following features.

8. The first detection unit is composed of hardware, The second detection unit is composed of a computer that functions by executing a program. A power control device according to any one of claims 1 to 7.

9. The aforementioned physical quantity is the voltage value. The second detection unit is, Set a value higher than the first threshold as the second threshold. A power control device according to any one of claims 1 to 8.

10. The aforementioned physical quantity is the current value, The second detection unit is, Set the second threshold value to a value lower than the first threshold value. A power control device according to any one of claims 1 to 8.

11. The aforementioned physical quantity is temperature. The second detection unit is, Set the second threshold value to a value lower than the first threshold value. A power control device according to any one of claims 1 to 8.

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