Power supply control device and power supply control method

Abstract

To provide a power supply control device and a power supply control method with which it is possible to estimate an abnormal system when the voltages of first and second systems exceed or fall below about an abnormality criterion threshold.SOLUTION: A power supply control device according to an embodiment comprises a connecting device and a controller. The connecting device is provided in an inter-system line that connects a first system for supplying the electric power of a first power supply to a first load and a second system for supplying the electric power of a second power supply to a second load. The controller cuts off the inter-system line upon detecting a power failure in the first or second system, and performs a confirmation process of confirming the failed system on the basis of changes in the voltages of the first and second systems in a first period. When unable to confirm the failed system in the confirmation process, the controller performs an estimation process of estimating the abnormal system on the basis of changes in the voltages of the first and second systems in a second period which is longer than the first period.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] There is a redundant power supply system including a first system that supplies power of a first power supply to a first load and a second system that supplies power of a second power supply to a second load. The redundant power supply system includes a power control device including a controller that controls an inter-system switch provided between the first system and the second system.

[0003] When the power control device mounted on a vehicle detects a power failure due to a voltage drop in the first system or the second system, it disconnects the inter-system switch. Thereafter, the power control device determines an abnormal system in which a power failure has occurred between the first system and the second system. The power control device causes the vehicle to perform an evacuation run using a normal system in which no power failure has occurred (see, for example, Patent Document 1).

[0004] The power control device determines a system in which the voltage has been continuously below an abnormal determination threshold for a predetermined time as an abnormal system. The power control device determines a system that has recovered until the voltage exceeds the abnormal determination threshold as a normal system.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the voltages of the first and second systems may fluctuate around the abnormality detection threshold if a half-short occurs rather than a complete ground fault, or if high load conditions persist intermittently. When the voltages of the first and second systems fluctuate around the abnormality detection threshold, the power control device may not be able to determine which system is faulty.

[0007] One embodiment, made in view of the above, aims to provide a power supply control device and a power supply control method that can estimate an abnormal system when the voltages of the first system and the second system fluctuate around an abnormality determination threshold. [Means for solving the problem]

[0008] A power control device according to one embodiment includes a connection device and a controller. The connection device is provided in an inter-system line connecting a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load. The controller controls the connection device. When the controller detects a power failure in the first system or the second system, it controls the connection device to disconnect the inter-system line. The controller performs a determination process to determine the system that has failed based on the changes in the voltage of the first system and the voltage of the second system during a first period. If the controller cannot determine the system that has failed through the determination process, it performs an estimation process to estimate a system that is strongly suspected of being abnormal as an abnormal system based on the changes in the voltage of the first system and the voltage of the second system during a second period which is longer than the first period. [Effects of the Invention]

[0009] A power control device and power control method according to one embodiment have the effect of being able to estimate an abnormal system when the voltages of the first system and the second system fluctuate around an abnormality detection threshold. [Brief explanation of the drawing]

[0010] [Figure 1]Figure 1 is an explanatory diagram of the configuration and operation of the power control device according to the embodiment. [Figure 2] Figure 2 is an explanatory diagram of the configuration and operation of the power control device according to the embodiment. [Figure 3] Figure 3 is an explanatory diagram of the configuration and operation of the power control device according to the embodiment. [Figure 4] Figure 4 is an explanatory diagram of the configuration and operation of the power control device according to the embodiment. [Figure 5] Figure 5 is an explanatory diagram showing the state patterns of the first and second systems according to the embodiment. [Figure 6] Figure 6 is an explanatory diagram of the abnormality determination process according to the embodiment. [Figure 7] Figure 7 is an explanatory diagram of the normal confirmation process according to the embodiment. [Figure 8] Figure 8 is an explanatory diagram of the first estimation process according to the embodiment. [Figure 9] Figure 9 is an explanatory diagram of the second estimation process according to the embodiment. [Figure 10] Figure 10 is a flowchart showing an example of a process performed by the controller of the power control device according to the embodiment. [Figure 11] Figure 11 is a flowchart showing an example of a process performed by the controller of the power control device according to the embodiment. [Figure 12] Figure 12 is a flowchart showing an example of a process performed by the controller of the power control device according to the embodiment. [Figure 13] Figure 13 is a flowchart showing an example of a process performed by the controller of the power control device according to this embodiment. [Figure 14] Figure 14 is a flowchart showing an example of a process performed by the controller of the power control device according to this embodiment. [Figure 15] Figure 15 is a flowchart showing an example of a process performed by the controller of the power control device according to this embodiment. [Figure 16]FIG. 16 is a flowchart showing an example of the processing executed by the controller of the power control device according to the embodiment. [Figure 17] FIG. 17 is a flowchart showing an example of the processing executed by the controller of the power control device according to the embodiment. [Figure 18] FIG. 18 is a flowchart showing an example of the processing executed by the controller of the power control device according to the embodiment. [Figure 19] FIG. 19 is a flowchart showing an example of the processing executed by the controller of the power control device according to the embodiment. [Figure 20] FIG. 20 is an explanatory diagram of the configuration and operation of the power control device according to a modified example of the embodiment.

Embodiments for Carrying Out the Invention

[0011] <000管理制御装置094>Hereinafter, embodiments of a power control device and a power control method will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments shown below. Hereinafter, a power control device mounted on a vehicle having an automatic driving function and supplying power to a load will be described as an example.

[0012] Hereinafter, the case where the vehicle on which the power control device is mounted is an electric vehicle or a hybrid vehicle will be described, but the vehicle on which the power control device is mounted may be an engine vehicle that runs by an internal combustion engine.

[0013] [1. Configuration of Power Control Device] Referring to FIGS. 1 to 4, the configuration and operation of the power control device 1 according to the embodiment will be described. FIGS. 1 to 4 are explanatory diagrams of the configuration and operation of the power control device according to the embodiment. As shown in FIG. 1, the power control device 1 according to the embodiment is connected to a first power source 10, a first load 101, a general load 102, a second load 103, and an automatic driving control device 100.

[0014] The power control device 1 comprises a first system 110 and a second system 120. The first system 110 is a power supply system that supplies power from the first power supply 10 to the first load 101 and the general load 102. The second system 120 is a power supply system that supplies power from the second power supply 20, which will be described later, to the second load 103.

[0015] The first load 101 includes loads for autonomous driving. The first load 101 includes the steering motor, electric brake system, and onboard cameras that operate during autonomous driving. The general load 102 includes the display, air conditioning, audio, video, and various lights.

[0016] The second load 103 includes some of the functions for automatic driving that are present in the first load 101. The second load 103 includes the minimum necessary equipment for FOP (fail-safe control), such as a steering motor, electric brake system, and radar. The first load 101, general load 102, and second load 103 are powered by the power supply control device 1.

[0017] The automatic driving control device 100 is a device that controls the vehicle to drive automatically. The automatic driving control device 100 drives the vehicle by operating the first load 101 and the second load 103. If a power failure such as a ground fault occurs in the first system 110 during automatic driving, the automatic driving control device 100 can perform FOP using the second load 103. If a power failure such as a ground fault occurs in the second system 120, the automatic driving control device 100 can perform FOP using the first load 101.

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

[0019] DC / DC11 is connected to the generator and a high-voltage battery with a higher voltage than PbB12. DC / DC11 steps down the voltage of the generator and the high-voltage battery and outputs it to the first system 110. The generator is an alternator that generates electricity by converting the kinetic energy of a moving vehicle. The high-voltage battery is a vehicle drive battery installed in electric vehicles and hybrid vehicles.

[0020] When the first power supply 10 is installed in an engine-powered 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.

[0021] The power control device 1 comprises a second power supply 20, an inter-system switch 41, a battery switch 42, a controller 3, a first voltage sensor 51, and a second voltage sensor 52. The second power supply 20 is a backup power supply for when the power supply from the first power supply 10 becomes unavailable. The second power supply 20 is equipped with 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.

[0022] The inter-system switch 41 is installed in the inter-system line 130 that connects the first system 110 and the second system 120. The inter-system switch 41 is a switch that can connect and disconnect the first system 110 and the second system 120.

[0023] The inter-system switch 41 may be a DC / DC converter. In this case, the DC / DC converter is controlled by the controller 3. The DC / DC converter electrically connects the first system 110 and the second system 120 by starting operation. The DC / DC converter disconnects the electrical connection between the first system 110 and the second system 120 by stopping operation.

[0024] The inter-system switch 41 is an example of a connection device provided on the inter-system line 130. 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. Disconnecting the inter-system switch 41 means disconnecting the electrical connection between the first system 110 and the second system 120, that is, interrupting it.

[0025] The first voltage sensor 51 is installed in the first system 110. The first voltage sensor 51 detects the voltage of the first system 110. The first voltage sensor 51 outputs the detection result to the controller 3. The second voltage sensor 52 is installed in the second system 120. The second voltage sensor 52 detects the voltage of the second system 120. The second voltage sensor 52 outputs the detection result to the controller 3.

[0026] Controller 3 includes a microcomputer with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and various circuits. Controller 3 may also be composed of hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0027] Controller 3 controls the operation of the power control device 1 by executing a program stored in ROM by the CPU, using RAM as a working area. Controller 3 also controls the inter-system switch 41 and the battery switch 42.

[0028] The controller 3 detects ground faults in the first system 110 or the second system 120 based on the detection results input from the first voltage sensor 51 and the second voltage sensor 52. A specific example of the ground fault detection method by the controller 3 will be described later.

[0029] If controller 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 controller 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 controller 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] When controller 3 detects a power failure such as a ground fault in the first system 110, it shuts off the inter-system switch 41 and connects the battery switch 42. As a result, the controller supplies power from the second power supply 20 to the second load 103. When controller 3 detects a power failure such as a ground fault in the second system 120, it shuts off the inter-system switch 41 and the battery switch 42. As a result, controller 3 supplies power from the first power supply 10 to the first load 101 and the general load 102.

[0031] The power control device 1 can use the other functioning system even if one of the first system 110 and the second system 120 experiences a ground fault during automatic operation. In other words, the power control device 1 can perform a Forward Operation (FOP) to move the vehicle to a safe location by using the other functioning system as instructed by the automatic driving control device 100. This allows the automatic driving control device 100 to stop the vehicle in a safe location.

[0032] [2. Normal operation of the power control device] As shown in Figure 1, under normal conditions when no ground faults occur in the first system 110 and the second system 120, the controller 3 disconnects the battery switch 42 and connects the inter-system switch 41. As a result, the controller 3 supplies power from the first power supply 10 to the first load 101, the general load 102, and the second load 103. In addition, under normal conditions when no ground faults occur, the controller 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] The operation of the power control device 1 during a ground fault will now be explained. As shown in Figure 2, in the power control device 1, 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. As a result, the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 will be below the abnormality detection threshold.

[0034] When the voltage detected by the second voltage sensor 52 falls below the abnormality detection threshold, the controller 3 tentatively determines that a ground fault 200 or 201 has occurred in the first system 110 or the second system 120.

[0035] When controller 3 makes the preliminary determination, it outputs an automatic operation prohibition signal to the automatic operation control device 100. Also, when controller 3 makes a preliminary determination that ground faults 200 and 201 have occurred, it shuts off the inter-system switch 41 and connects the battery switch 42.

[0036] Hereafter, the tripping of the inter-system switch 41 based on the results of the preliminary determination will also be referred to as pre-tripping. As a result, the connection between the first system 110 and the second system 120 is disconnected. Therefore, power is supplied from the first power source 10 to the first system 110, and power is supplied from the second power source 20 to the second system 120.

[0037] Furthermore, the controller 3 can also make a provisional determination that a ground fault has occurred in the first system 110 or the second system 120 if the voltage detected by at least one of the first voltage sensor 51 or the second voltage sensor 52 falls below an abnormality determination threshold.

[0038] Thus, when the controller 3 provisionally determines that either the first system 110 or the second system 120 has lost power, it controls the inter-system switch 41 to disconnect the inter-system line 130, i.e., pre-shuts it off. After pre-shutting it off, the controller 3 performs a confirmation process to determine which system has lost power based on the changes in the voltage of the first system 110 and the voltage of the second system 120 during the first period.

[0039] The voltage of the first system 110 is the voltage detected by the first voltage sensor 51. The voltage of the second system 120 is the voltage detected by the second voltage sensor 52. The first period is, for example, 100ms, but is not limited to 100ms. Specific examples of the confirmation process will be described later with reference to Figures 6 and 7.

[0040] In the confirmation process, the controller 3 determines that a ground fault 200 has occurred in the first system 110 if the voltage of the first system 110 has been below the abnormality determination threshold for a period of 1 or more consecutively, and the voltage of the second system 120 has been above the normal determination threshold for a period of 1 or more consecutively.

[0041] As shown in Figure 3, when the controller 3 determines that a ground fault 200 has occurred in the first system 110, it supplies power from the second power supply 20 to the second load 103 while maintaining the disconnection of the inter-system switch 41 and the connection of the battery switch 42.

[0042] Controller 3 notifies the automatic driving control device 100 of this fact. The automatic driving control device 100 operates the second load 103 using power supplied from the second power supply 20, and drives the vehicle to a safe location and stops. The automatic driving control device 100 may also be configured to start the escape drive when an automatic driving prohibition signal is input from the power supply control device 1 based on a preliminary determination.

[0043] On the other hand, in the confirmation process, the controller 3 makes a final determination that a ground fault 201 has occurred in the second system 120 if the voltage of the second system 120 is below the abnormal determination threshold for the first period and the voltage of the first system 110 is above the normal determination threshold for the first period or longer.

[0044] As shown in Figure 4, when the controller 3 determines that a ground fault 201 has occurred in the second system 120, it keeps the inter-system switch 41 disconnected and disconnects the battery switch 42 to supply power from the first power supply 10 to the first load 101 and the general load 102.

[0045] Controller 3 notifies the automatic driving control device 100 of this. The automatic driving control device 100 operates the first load 101 using the power supplied from the first power supply 10, and drives the vehicle to a safe location and stops. The automatic driving control device 100 may be configured to start the escape drive when an automatic driving prohibition signal is input from the power supply control device 1.

[0046] Controller 3 is connected to the second power supply 20 by line 22 and monitors the voltage of the second power supply 20 (State of Charge (SOC) of LiB 21) via line 22. When the SOC of the second power supply 20 falls below a predetermined value, Controller 3 activates the inter-system switch 41 and the battery switch 42, charging the second power supply 20 with the power from the first power supply 10.

[0047] [4. Patterns of the state of the first and second systems] In the power control device 1, when it is tentatively determined that a ground fault has occurred in the first system 110 or the second system 120, it may be that a half-short is occurring rather than a complete ground fault, or that a high load condition is continuing intermittently.

[0048] In the power control device 1, if a half-short occurs or if a high load condition persists intermittently, the voltage of the first system 110 or the voltage of the second system 120 may fluctuate around the abnormality detection threshold.

[0049] Controller 3 may not be able to determine which system is faulted if the voltage of the first system 110 or the voltage of the second system 120 fluctuates around the abnormality detection threshold. In other words, if the voltage of the first system 110 or the second system 120 recovers to exceed the abnormality detection threshold before the first period elapses after Controller 3 has made a provisional determination that a ground fault has occurred, Controller 3 cannot determine that the system whose voltage has recovered is the faulty system that had the ground fault.

[0050] Referring to Figure 5, the state patterns of the first system 110 and the second system 120, and the actions taken by the controller 3 in each pattern will be explained. Figure 5 is an explanatory diagram showing the state patterns of the first system and the second system according to the embodiment.

[0051] As shown in Figure 5, there are six possible states for the first system 110 and the second system 120 after the preliminary determination, from pattern (1) to (6). Pattern (1) is a pattern in which both the first system 110 and the second system 120 have been determined to be either an abnormal system or a normal system. When both the first system 110 and the second system 120 have been determined to be normal systems, the controller 3 conducts the inter-system switch 41 and disconnects the battery switch 42, returning to the normal operation shown in Figure 1.

[0052] Furthermore, if both the first system 110 and the second system 120 are confirmed to be abnormal systems, the controller 3 shuts off the inter-system switch 41 and the battery switch 42, and notifies the automatic operation control device 100 of this. After that, the controller 3 stops operating.

[0053] Furthermore, if the controller 3 has determined that the first system 110 is an abnormal system and the second system 120 is a normal system, it will turn off the inter-system switch 41 and turn on the battery switch 42, as shown in Figure 3. As a result, power will be supplied from the second power supply 20 to the second load 103 via the second system 120.

[0054] Furthermore, if the controller 3 has determined that the first system 110 is a normal system and the second system 120 is an abnormal system, it will turn off the inter-system switch 41 and the battery switch 42, as shown in Figure 4. As a result, power will be supplied from the first power supply 10 to the first load 101 and the general load 102 via the first system 110.

[0055] Pattern (2) is a pattern in which the state of both the first system 110 and the second system 120 is undetermined. In other words, pattern (2) is a pattern in which it has not been determined whether either the first system 110 or the second system 120 is abnormal or normal. In the case of pattern (2), the controller 3 estimates that one of the systems suspected of having a ground fault is a ground fault. The controller 3 estimates the other system to be normal and causes the vehicle to move to safety via the other system. For example, if the second system 120 is suspected, the controller 3 estimates that the second system 120 has a ground fault and the first system 110 is normal. In that case, the controller 3 shuts off the inter-system switch 41 and the battery switch 42. As a result, the controller 3 causes the vehicle to move to safety by supplying power from the first power supply 10 to the first load 101 and the general load 102 via the first system 110.

[0056] Pattern (3) is a pattern where the state of the first system 110 is confirmed to be a ground fault, and the state of the second system 120 is undetermined. Since the second system 120, which is undetermined, is not completely ground faulted, power supply is possible. Therefore, in the case of pattern (3), the controller 3 considers the second system 120, which is undetermined, to be normal and causes the train to move to safety via the second system 120.

[0057] Pattern (4) is a pattern in which the state of the first system 110 is undetermined, and the state of the second system 120 is confirmed to be ground fault. Since the first system 110 on the undetermined side is not completely ground faulted, power supply is possible. Therefore, in the case of pattern (4), the controller 3 considers the first system 110 on the undetermined side to be normal and causes the train to move to safety via the first system 110.

[0058] Pattern (5) is a pattern in which the state of the first system 110 is confirmed to be normal, and the state of the second system 120 is undetermined. The first system 110 is confirmed to be normal, while the second system 120, which is undetermined, is in an unstable state. Therefore, in the case of pattern (5), the controller 3 considers the second system 120 to be on a ground fault, maintains the interruption of the inter-system switch 41, interrupts the battery switch 42, and causes the first system 110 to perform evasive maneuvers.

[0059] Pattern (6) is a pattern in which the state of the first system 110 is undetermined, and the state of the second system 120 is confirmed to be normal. The second system 120 is confirmed to be normal, and the first system 110, which is the undetermined side, is in an unstable state. Therefore, in the case of pattern (6), the controller 3 considers the first system 110 to be ground faulted and causes the second system 120 to perform evasive maneuvers.

[0060] [5. Explanation of actions taken when an abnormality is confirmed] The operation of the controller 3 when an abnormality is confirmed will be explained with reference to Figure 6. Figure 6 is an explanatory diagram of the abnormality confirmation process when the first system 110 is experiencing a ground fault according to the embodiment.

[0061] As shown in Figure 6, the abnormality detection threshold is set to a lower value than the normality detection threshold. The normality detection threshold is set to a value that guarantees no ground faults have occurred in systems with a voltage higher than that value. The abnormality detection threshold is set to a value that guarantees a ground fault has occurred in systems with a voltage lower than that value.

[0062] In the example shown in Figure 6, the voltage of the first system 110 changes from above the normal threshold to below the normal threshold at time T11, and then from above the abnormal threshold to below the abnormal threshold at time T12. Subsequently, the voltage of the first system 110 changes from below the abnormal threshold to above the abnormal threshold at time T13, and then from below the normal threshold to above the normal threshold at time T14. Further after that, the voltage of the first system 110 changes from above the normal threshold to below the normal threshold at time T15, and then from above the abnormal threshold to below the abnormal threshold at time T16. In this case, the controller 3 pre-cuts the inter-system switch 41 at time T12, when the voltage of the first system 110 first changes from above the abnormal threshold to below the abnormal threshold, and starts the main determination.

[0063] Controller 3 includes a normal duration timer for the first system 110 and an abnormal duration timer for the first system 110. The normal duration timer for the first system 110 is a timer that measures the duration for which the voltage of the first system 110 is above a normal threshold. In the example shown in Figure 6, the count value Tm13 of the normal duration timer for the first system 110 is reset at time T11 when the voltage of the first system 110 first falls below the normal threshold. The count value Tm13 then increases from time T14 when the voltage of the first system 110 is above the normal threshold, but is reset at time T15 when the voltage of the first system 110 goes from above the normal threshold to below the normal threshold, and this reset state continues thereafter.

[0064] Controller 3 determines the state of the first system 110 as "normal but not yet determined" if the time from time T14 to time T15, when the count value Tm13 of the normal duration timer of the first system 110 is equal to or greater than the normal determination threshold, is less than the first period, which is the normal determination time. The normal determination time is 100ms, but is not limited to 100ms.

[0065] The abnormal duration timer for the first system 110 is a timer that measures the duration for which the voltage of the first system 110 is below the abnormality detection threshold. In the example shown in Figure 6, the count value Tm11 of the abnormal duration timer for the first system 110 increases from the time T12 when the voltage of the first system 110 falls below the abnormality detection threshold, but is reset at the time T13 when the voltage of the first system 110 rises above the abnormality detection threshold.

[0066] Subsequently, the count value Tm1 continues to increase from time T16, when it falls below the abnormality detection threshold again. Controller 3 determines the state of the first system 110 to be abnormal when the count value Tm11 of the abnormality duration timer of the first system 110 exceeds the first period, which is the abnormality confirmation time. The abnormality confirmation time is 100ms, but is not limited to 100ms. Controller 3 uses time T17, when the abnormality is confirmed, as the timing for this determination.

[0067] Thus, if the first system 110 is experiencing a ground fault, the normal duration will not exceed the normal determination time, which is the first period, and the status will remain normal but undetermined. On the other hand, if the first system 110 is experiencing a ground fault, the abnormal duration will exceed the abnormal determination time, which is the first period, and the status will remain abnormal. Controller 3 prioritizes the determined state over the undetermined state. Therefore, Controller 3 makes a final determination that the first system 110 is abnormal, i.e., has a ground fault.

[0068] Although the first period for determining normality and the first period for determining abnormality were set to be the same length, they do not necessarily have to be the same length and may be different. For example, the first period for determining normality may be 100 ms, and the first period for determining abnormality may be 80 ms.

[0069] [6. Explanation of actions taken when a successful result is confirmed] The operation of the controller 3 when normal operation is confirmed will be explained with reference to Figure 7. Figure 7 is an explanatory diagram of the normal operation confirmation process when the first system 110 is not experiencing a ground fault according to this embodiment.

[0070] In the example shown in Figure 7, the voltage of the first system 110 changes from above the normal threshold to below the normal threshold at time T21, and then from above the abnormal threshold to below the abnormal threshold at time T22. Subsequently, the voltage of the first system 110 changes from below the abnormal threshold to above the abnormal threshold at time T23, and then from below the normal threshold to above the normal threshold at time T24. In this case, the controller 3 pre-cuts the inter-system switch 41 at time T22, when the voltage of the first system 110 first changes from above the abnormal threshold to below the abnormal threshold, and starts the main determination.

[0071] In the example shown in Figure 7, the count value Tm13 of the normal duration timer for the first system 110 is reset at time T21 when the voltage of the first system 110 first falls below the normal determination threshold. The count value Tm13 then continues to increase from time T24 when the voltage of the first system 110 rises above the normal determination threshold. Controller 3 determines the state of the first system 110 to be normal when the count value Tm13 of the normal duration timer for the first system 110 exceeds the normal determination time. Controller 3 uses time T25, when normality is determined, as the timing for this determination.

[0072] In the example shown in Figure 7, the count value Tm11 of the abnormal duration timer for the first system 110 increases from time T22, when the voltage of the first system 110 falls below the abnormality detection threshold, to time T23. The count value Tm11 of the abnormal duration timer for the first system 110 is reset at time T23, when the voltage of the first system 110 goes from below the abnormality detection threshold to above the abnormality detection threshold, and this reset state continues thereafter. If the time from time T22, when the voltage of the first system 110 falls below the abnormality detection threshold, to time T23 is less than the abnormality confirmation time, the controller 3 sets the state of the first system 110 to "abnormal undetermined".

[0073] Thus, if the first system 110 is normal, the duration of the abnormality will not exceed the abnormality confirmation time, which is the first period, and the abnormality will remain unconfirmed. On the other hand, if the first system 110 is normal, the duration of normality will exceed the normality confirmation time, which is the first period, and therefore the normality will be confirmed. Controller 3 prioritizes the confirmed state over the unconfirmed state. Therefore, controller 3 makes a final determination that the first system 110 is normal.

[0074] Controller 3 further includes a normal duration timer for the second system 120 and an abnormal duration timer for the second system 120. The normal duration timer for the second system 120 is a timer that measures the duration for which the voltage of the second system 120 is equal to or greater than a normal threshold. The abnormal duration timer for the second system 120 is a timer that measures the duration for which the voltage of the second system 120 is equal to or less than an abnormal threshold. Based on the count value Tm23 of the normal duration timer for the second system 120 and the count value Tm21 of the abnormal duration timer for the second system 120, Controller 3 determines the normal and abnormal status of the second system 120 in the same manner as for the first system 110.

[0075] [7. Explanation of operation when normal or abnormal conditions are not yet determined] The operation of the controller 3 when normal and abnormal conditions are undetermined will be explained with reference to Figures 8 and 9. Figure 8 is an explanatory diagram of the first estimation process according to the embodiment. Figure 9 is an explanatory diagram of the second estimation process according to the embodiment.

[0076] If the controller 3 cannot determine which system has failed through the confirmation process, it performs an estimation process. Specifically, the controller 3 performs an estimation process to estimate which system is strongly suspected of being abnormal as an abnormal system, based on the changes in the voltage of the first system 110 and the voltage of the second system 120 during the second period, which is longer than the first period.

[0077] The second period is 1 s (1000 ms), but is not limited to 1 s. The abnormality detection time shown in Figures 8 and 9 is an example of the second period. The controller 3 can estimate the abnormal system by estimation processing when the voltages of the first system 110 and the second system 120 fluctuate around the abnormality detection threshold.

[0078] Controller 3 includes an abnormal cumulative time timer for the first system 110, an abnormal cumulative count counter for the first system 110, an abnormal cumulative time timer for the second system 120, and an abnormal cumulative count counter for the second system 120.

[0079] The cumulative abnormal time timer for the first system 110 is a timer that measures the cumulative time during which the voltage of the first system 110 is below the normal judgment threshold and the cumulative time during which the voltage of the first system 110 is below the abnormal judgment threshold. Here, the count value of the cumulative time during which the voltage of the first system 110 is below the normal judgment threshold is denoted as Tm14. The count value of the cumulative time during which the voltage of the first system 110 is below the abnormal judgment threshold is denoted as Tm12. The count values ​​Tm12 and Tm14 are not reset during the abnormal judgment time, which is the second period from the time T32 to the time T42 when this judgment is started.

[0080] The cumulative abnormality count counter for the first system 110 is a counter that measures the cumulative number of times the voltage of the first system 110 has gone from above the normal judgment threshold to below the normal judgment threshold, and the cumulative number of times the voltage of the first system 110 has gone from above the abnormal judgment threshold to below the abnormal judgment threshold. Here, the count value of the cumulative number of times the voltage of the first system 110 has gone to below the normal judgment threshold is denoted as Ct12. The count value of the cumulative number of times the voltage of the first system 110 has gone to below the abnormal judgment threshold is denoted as Ct11. The count values ​​Ct11 and Ct12 are not reset during the abnormality judgment time, which is the second period from time T32 to time T42 when this judgment is started.

[0081] The abnormal cumulative time timer for the second system 120 is a timer that measures the cumulative time during which the voltage of the second system 120 is below the normal judgment threshold and the cumulative time during which the voltage of the second system 120 is below the abnormal judgment threshold. Here, the count value of the cumulative time during which the voltage of the first system 110 is below the normal judgment threshold is denoted as Tm24. The count value of the cumulative time during which the voltage of the first system 110 is below the abnormal judgment threshold is denoted as Tm22. The count values ​​Tm22 and Tm24 are not reset during the abnormal judgment time, which is the second period from the time T52 when this judgment starts to the time T60.

[0082] The cumulative number of abnormalities counter for the first system 110 is a counter that measures the cumulative number of times the voltage of the first system 110 has gone from above the abnormality threshold to below the normal threshold, and the cumulative number of times the voltage of the first system 110 has gone from above the abnormality threshold to below the abnormality threshold. Here, the count value of the cumulative number of times the voltage of the second system 120 has gone below the normal threshold is set to Ct22. The count value of the cumulative number of times the voltage of the first system 110 has gone below the abnormality threshold is set to Ct21. The count values ​​Ct21 and Ct22 are not reset during the abnormality determination time, which is the second period from time T52 to time T60 when this determination is started.

[0083] [7-1. Estimation processing for the first system] In the example shown in Figure 8, the voltage of the first system 110 changes from above the normal threshold to below the normal threshold at time T31, and from above the abnormal threshold to below the abnormal threshold at time T32. Subsequently, the voltage of the first system 110 changes from below the abnormal threshold to above the abnormal threshold at time T33, and from below the normal threshold to above the normal threshold at time T34. Subsequently, the voltage of the first system 110 changes from above the normal threshold to below the normal threshold at time T35, and from above the abnormal threshold to below the abnormal threshold at time T36.

[0084] Subsequently, the voltage of the first system 110 rises from below the abnormality threshold to above the abnormality threshold at time T37, and then falls back below the abnormality threshold at time T38. Subsequently, the voltage of the first system 110 rises from below the abnormality threshold to above the abnormality threshold at time T39, and then falls back below the abnormality threshold at time T40. Subsequently, the voltage of the first system 110 rises from below the abnormality threshold to above the abnormality threshold at time T41. Controller 3 pre-cuts the inter-system switch 41 at time T32, when the voltage of the first system 110 first rises from above the abnormality threshold to below the abnormality threshold, and starts the main determination.

[0085] In the example shown in Figure 8, the voltage of the first system 110 is above the normal determination threshold between time T34 and time T35. However, since the count value Tm13 of the normal duration timer for the first system 110 is within the normal determination time, it is determined to be undetermined as normal at time t42, after the abnormal determination time has elapsed.

[0086] Furthermore, within the abnormality detection time, the voltage of the first system 110 has the longest duration of being below the abnormality detection threshold between time T38 and time T39. However, since the count value Tm11 of the abnormality duration timer for the first system 110 is within the abnormality confirmation time, the controller 3 determines that the abnormality is not confirmed at time t42, after the abnormality detection time has elapsed.

[0087] If, at time t42 after the abnormality detection time has elapsed, the controller 3 refers to the count values ​​Tm14 and Tm12 of the cumulative abnormality time timer for the first system 110 and the count values ​​Ct12 and Ct11 of the cumulative abnormality count counter for the first system 110, if neither the normal nor abnormal status of the first system 110 has been determined.

[0088] Furthermore, if the normality or abnormality of the first system 110 is not yet determined, the controller 3 refers to the count values ​​Tm24 and Tm22 of the cumulative abnormality time timer and the count values ​​Ct22 and Ct21 of the cumulative abnormality count counter of the second system 120. Based on these count values ​​Tm14, Tm12, Tm24, Tm22, Ct12, Ct11, Ct22, and Ct21, the controller 3 estimates the normality or abnormality of the first system 110.

[0089] In the example shown in Figure 8, the count value Tm14 of the cumulative abnormal time timer for the first system 110 at the end of the abnormality detection time t42 is 60. The count value Tm12 of the cumulative abnormal time timer for the first system 110 at the end of the abnormality detection time is 50. The count value Ct12 of the cumulative abnormality count counter for the first system 110 at the end of the abnormality detection time is 2. The count value Ct11 of the cumulative abnormality count counter for the first system 110 at the end of the abnormality detection time is 4.

[0090] [7-2. Estimation processing of the second system] In the example shown in Figure 9, the voltage of the second system 120 changes from above the normal threshold to below the normal threshold at time T51, and from above the abnormal threshold to below the abnormal threshold at time T52. Subsequently, the voltage of the second system 120 changes from below the abnormal threshold to above the abnormal threshold at time T53, and from below the normal threshold to above the normal threshold at time T54. Subsequently, the voltage of the second system 120 changes from above the normal threshold to below the normal threshold at time T55, and from above the abnormal threshold to below the abnormal threshold at time T56.

[0091] Subsequently, the voltage of the second system 120 rises from below the abnormality threshold to above the abnormality threshold at time T57, and rises from below the normality threshold to above the normality threshold at time T58. Then, the voltage of the second system 120 falls from above the normality threshold to below the normality threshold at time T59. At time T52, when the voltage of the second system 120 first rises from above the abnormality threshold to below the abnormality threshold, the controller 3 pre-shuts off the inter-system switch 41 and starts the main determination.

[0092] In the example shown in Figure 9, the voltage of the second system 120 is above the normal determination threshold between times T54 and T55, and between times T58 and T59. However, because the count value Tm23 of the normal duration timer for the second system 120 is within the normal determination time, the controller 3 determines that the system is not yet normal at time t60, after the abnormal determination time has elapsed.

[0093] Furthermore, the voltage of the second system 120 falls below the abnormality detection threshold between times T52 and T53, and between times T56 and T57. However, since the count value Tm21 of the abnormality duration timer for the second system 120 is within the abnormality confirmation time, the controller 3 determines that the abnormality is not confirmed at time t60, after the abnormality detection time has elapsed.

[0094] If, at time t60 after the abnormality detection time has elapsed, the controller 3 refers to the count values ​​Tm24 and Tm22 of the abnormality cumulative time timer for the second system 120 and the count values ​​Ct22 and Ct21 of the abnormality cumulative count counter for the second system 120, if neither the normal nor abnormal status of the second system 120 has been determined.

[0095] If the normality or abnormality of the second system 120 is not yet determined, the controller 3 refers to the count values ​​Tm14 and Tm12 of the cumulative abnormality time timer and the count values ​​Ct12 and Ct11 of the cumulative abnormality count counter of the first system 110. Based on these count values ​​Tm14, Tm12, Tm24, Tm22, Ct12, Ct11, Ct22, and Ct21, the controller 3 estimates the normality or abnormality of the second system 120.

[0096] In the example shown in Figure 9, the count value Tm24 of the cumulative abnormal time timer for the second system 120 at the end of the abnormality detection time t60 is 50. The count value Tm22 of the cumulative abnormal time timer for the first system 110 at the end of the abnormality detection time is 20. The count value Ct22 of the cumulative abnormality count counter for the first system 110 at the end of the abnormality detection time is 3. The count value Ct21 of the cumulative abnormality count counter for the first system 110 at the end of the abnormality detection time is 2.

[0097] A system in which the voltage remains below the abnormality threshold for an extended period is strongly suspected of being abnormal. Therefore, if, after the abnormality detection period has elapsed, it is not yet determined whether either the first system 110 or the second system 120 is normal or abnormal—that is, if both systems are neither determined to be normal nor abnormal—the controller 3 uses the first estimation method to estimate the abnormal system based on the cumulative time during which the voltage remained below the abnormality threshold. Specifically, the controller 3 estimates the system with the longer cumulative time between the cumulative time during which the voltage of the first system 110 remained below the abnormality threshold and the cumulative time during which the voltage of the second system 120 remained below the abnormality threshold as the abnormal system.

[0098] When the voltage of the first system 110 is in the state shown in Figure 8, and the voltage of the second system 120 is in the state shown in Figure 9, the count value Tm12 of the cumulative abnormality timer for the first system 110 is 50. On the other hand, the count value Tm22 of the cumulative abnormality timer for the second system 120 is 20. In this case, the controller 3 estimates the first system 110 to be the abnormal system. Therefore, even when it is not determined whether either the first system 110 or the second system 120 is normal or abnormal, the controller 3 can estimate which system is the abnormal system.

[0099] Furthermore, systems where the voltage remains below the normal threshold for an extended period are strongly suspected of being abnormal. Therefore, if it is not yet determined whether either the first system 110 or the second system 120 is normal or abnormal after the abnormality determination time has elapsed, the controller 3 uses a second estimation method to estimate the abnormal system based on the time spent below the normal threshold. Specifically, the controller 3 estimates the system with the longer cumulative time between the cumulative time the voltage of the first system 110 remains below the normal threshold and the cumulative time the voltage of the second system 120 remains below the normal threshold as the abnormal system.

[0100] When the voltage of the first system 110 is in the state shown in Figure 8, and the voltage of the second system 120 is in the state shown in Figure 9, the count value Tm12 of the cumulative abnormality timer for the first system 110 is 60. On the other hand, the count value Tm24 of the cumulative abnormality timer for the second system 120 is 50. In this case, the controller 3 estimates that the first system 110 is an abnormal system. Therefore, even when it is not determined whether either the first system 110 or the second system 120 is normal or abnormal, the controller 3 can estimate which system is abnormal.

[0101] Incidentally, if the cumulative time during which the voltage of the first system 110 is below the abnormality detection threshold is the same as the cumulative time during which the voltage of the second system 120 is below the abnormality detection threshold, or if the time difference is within the error range, the controller 3 may not be able to estimate the abnormal system during the estimation process.

[0102] In this case, the controller 3 estimates the system with the longer cumulative time between the cumulative time the voltage of the first system 110 is below the normal threshold and the cumulative time the voltage of the second system 120 is below the normal threshold as the abnormal system. That is, the controller 3 estimates the abnormal system with the first estimation method as its first priority. If the controller 3 cannot estimate the abnormal system using the first estimation method, it then estimates the abnormal system using the second estimation method.

[0103] As a result, the controller 3 can estimate the faulty system when the cumulative time during which the voltage of the first system 110 is below the abnormality detection threshold is the same as the cumulative time during which the voltage of the second system 120 is below the abnormality detection threshold, or when the time difference is within the error range.

[0104] Furthermore, a system in which the voltage falls below the abnormal threshold many times is strongly suspected of being abnormal. Therefore, if it has not been determined whether either the first system 110 or the second system 120 is normal or abnormal after the abnormality determination time has elapsed, the controller 3 uses a third estimation method to estimate the abnormal system based on the number of times the voltage falls below the abnormal threshold. Specifically, the controller 3 estimates the system with a higher number of occurrences of the voltage of the first system 110 falling below the abnormal determination threshold and the voltage of the second system 120 falling below the abnormal determination threshold as the abnormal system.

[0105] When the voltage of the first system 110 is in the state shown in Figure 8, and the voltage of the second system 120 is in the state shown in Figure 9, the count value Ct11 of the cumulative abnormality counter for the first system 110 is 4. The count value Ct21 of the cumulative abnormality counter for the second system 120 is 2. In this case, the controller 3 estimates the first system 110 to be an abnormal system. Therefore, even when it is not determined whether either the first system 110 or the second system 120 is normal or abnormal, the controller 3 can estimate which system is abnormal.

[0106] Furthermore, a system in which the voltage falls below the normal threshold infrequently is, in other words, a system in which the voltage falls within the normal range infrequently, and is therefore strongly suspected of being abnormal. For this reason, if it has not been determined whether either the first system 110 or the second system 120 is normal or abnormal after the abnormality determination time has elapsed, the controller 3 uses a fourth estimation method to estimate the abnormal system based on the number of times the voltage falls below the normal threshold. Specifically, the controller 3 estimates the system with the fewer number of times the voltage of the first system 110 falls below the normal determination threshold and the number of times the voltage of the second system 120 falls below the normal determination threshold as the abnormal system.

[0107] When the voltage of the first system 110 is in the state shown in Figure 8, and the voltage of the second system 120 is in the state shown in Figure 9, the count value Ct12 of the cumulative abnormality counter for the first system 110 is 2. The count value Ct22 of the cumulative abnormality counter for the second system 120 is 3. In this case, the controller 3 estimates the first system 110 to be an abnormal system. Therefore, even when it is not determined whether either the first system 110 or the second system 120 is normal or abnormal, the controller 3 can estimate which system is abnormal.

[0108] The controller 3 may be configured to estimate the system with the higher number of occurrences of the voltage of the first system 110 rising from below the normal threshold to above the normal threshold, and the voltage of the second system 120 rising from below the normal threshold to above the normal threshold, as the abnormal system.

[0109] Incidentally, if the number of times the voltage of the first system 110 falls below the abnormality detection threshold is the same as the number of times the voltage of the second system 120 falls below the abnormality detection threshold, or if the difference in the number of times is within the error range, the controller 3 may not be able to estimate the abnormal system during the estimation process.

[0110] In this case, the controller 3 estimates the system with the fewer cumulative number of times the voltage of the first system 110 has fallen below the normal threshold and the voltage of the second system 120 has fallen below the normal threshold as the abnormal system. In other words, the controller 3 estimates the abnormal system with the third estimation method as its first priority. If the controller 3 cannot estimate the abnormal system using the third estimation method, it then estimates the abnormal system using the fourth estimation method.

[0111] As a result, the controller 3 can estimate the faulty system if the number of times the voltage of the first system 110 falls below the abnormality detection threshold is the same as the number of times the voltage of the second system 120 falls below the abnormality detection threshold, or if the difference in the number of times is within the error range.

[0112] Controller 3 may be configured to re-examine abnormal systems when it determines that a system is highly likely to be abnormal. That is, for systems that Controller 3 determines are highly likely to be abnormal as a result of the estimation process described above, it performs the confirmation process and estimation process described above again. This allows Controller 3 to more reliably identify abnormal systems.

[0113] In the embodiments described above, the controller 3 estimated the abnormal system using one or a combination of the first to fourth estimation methods, but it may also estimate the abnormal system using all of the first to fourth estimation methods. Specifically, the controller 3 estimates the abnormal system using each of the first to fourth estimation methods and estimates the system that is most frequently estimated to be abnormal as the abnormal system. For example, suppose the controller 3 estimates that the first system is abnormal using the first to third estimation methods and estimates that the second system is abnormal using the fourth estimation method. In this case, since the ratio is 3 to 1, the controller 3 estimates that the first system is abnormal.

[0114] [8. Processes executed by the controller] Next, referring to Figures 10 to 19, the processes executed by the controller 3 of the power control device 1 according to this embodiment will be described. Figures 10 to 19 are flowcharts showing an example of the processes executed by the controller of the power control device according to this embodiment.

[0115] [8-1. Abnormal System Detection Process] When controller 3 provisionally determines that there is a power failure in either the first system 110 or the second system 120, it starts the final determination process shown in Figure 10. Controller 3 repeats the process shown in Figure 10 until the abnormal system has been determined and estimated. Controller 3 is equipped with a final determination timer. This final determination timer is a timer that measures the abnormality determination time shown in Figures 8 and 9.

[0116] As shown in Figure 10, the controller 3 turns off the inter-system switch 41 and turns on the battery switch 42 (step S101). Next, the controller 3 starts the main determination timer (step S102). Note that the controller 3 executes the process in step S102 during the first abnormal system determination process. For the second and subsequent abnormal system determination processes, the controller 3 executes step S101 and then moves the process to step S103 without executing step S102.

[0117] Next, in step S103, the controller 3 executes the first system ground fault measurement process. A specific example of the first system ground fault measurement process will be described later with reference to Figure 11. Next, the controller 3 executes the first system normal measurement process (step S104). A specific example of the first system normal measurement process will be described later with reference to Figure 12.

[0118] Next, controller 3 performs the second system ground fault measurement process (step S105). A specific example of the second system ground fault measurement process will be described later with reference to Figure 13. Next, controller 3 performs the second system normal measurement process (step S106). A specific example of the second system normal measurement process will be described later with reference to Figure 14.

[0119] Next, controller 3 performs an abnormality determination process (step S107). Specific examples of the abnormality determination process will be described later with reference to Figures 15 and 16. Next, controller 3 determines whether the measurement time of this determination timer has exceeded the threshold abnormality determination time (step S108). The threshold is, for example, 1 s (1000 ms), but the threshold is not limited to 1 s.

[0120] If controller 3 determines that the measurement time of this judgment timer has not exceeded the threshold (step S108, No), it terminates the process. After that, controller 3 restarts the abnormal system detection process from step S101.

[0121] If controller 3 determines that the measurement time of this determination timer has exceeded the threshold (step S108, Yes), it determines whether the state of both the first system 110 and the second system 120 has been determined (step S109). If controller 3 determines that the state of both systems has been determined (step S109, Yes), it terminates the process.

[0122] Subsequently, controller 3 restarts the abnormal system determination process from step S101. If controller 3 determines that the state of either or both of the systems is not yet determined (step S109, No), it executes the abnormality estimation process (step S110) and terminates the process.

[0123] Specific examples of the anomaly estimation process will be described later with reference to Figures 17 and 18. Subsequently, the controller 3 restarts the anomaly system determination process from step S101.

[0124] [8-2. Ground fault measurement processing for the first system] The first system ground fault measurement process will be described with reference to Figure 11. As shown in Figure 11, when the controller 3 starts the first system ground fault measurement process, it determines whether the voltage V1 of the first system 110 detected by the first voltage sensor 51 is below an abnormality determination threshold (step S201). The controller 3 may be configured to determine whether the voltage V1 of the first system 110 detected by the first voltage sensor 51 is below an abnormality determination threshold instead of the process in step S201.

[0125] If the controller 3 determines that the voltage V1 of the first system 110 is not below the abnormality detection threshold (step S201, No), it clears the count value Tm11 of the abnormality duration timer for the first system 110 (step S206).

[0126] In other words, the controller 3 sets the count value Tm11 of the abnormal duration timer for the first system 110 to "0" and terminates the ground fault measurement process for the first system. After that, the controller 3 moves the process to the normal measurement process for the first system (step S104) shown in Figure 10.

[0127] If the controller 3 determines that the voltage V1 of the first system 110 is below the abnormality detection threshold (step S201, Yes), it determines whether the change in the voltage V1 of the first system 110 is a change from above the abnormality detection threshold to below the abnormality detection threshold (step S202).

[0128] If the controller 3 determines that the change in the voltage V1 of the first system 110 is not a change from above the abnormality detection threshold to below the abnormality detection threshold (step S202, No), it moves the process to step S204.

[0129] If the controller 3 determines that the change in the voltage V1 of the first system 110 is a change from above the abnormality detection threshold to below the abnormality detection threshold (step S202, Yes), it moves the process to step S203. In step S203, the controller 3 increments the count value Ct11 of the cumulative abnormality count counter for the first system 110. That is, the controller 3 adds "1" to the count value Ct11 of the cumulative abnormality count counter for the first system 110.

[0130] Next, the controller 3 increments the count value Tm11 of the abnormal duration timer for the first system 110 (step S204). Then, the controller 3 increments the count value Tm12 of the abnormal cumulative time timer for the first system 110 (step S205), and terminates the first system ground fault measurement process. After that, the controller 3 moves the process to the first system normal measurement process shown in Figure 10 (step S104).

[0131] [8-3. First System Normal Measurement Processing] The first system normal measurement process will be described with reference to Figure 12. As shown in Figure 12, when the controller 3 starts the first system normal measurement process, it determines whether the voltage V1 of the first system 110 detected by the first voltage sensor 51 exceeds the normal determination threshold (step S301). The controller 3 may be configured to determine whether the voltage V1 of the first system 110 detected by the first voltage sensor 51 is equal to or greater than the normal determination threshold instead of the process in step S301.

[0132] If the controller 3 determines that the voltage V1 of the first system 110 has exceeded the normal determination threshold (step S301, Yes), it increments the count value Tm13 of the normal duration timer for the first system 110 (step S302) and terminates the first system normal measurement process. After that, the controller 3 moves the process to the second system ground fault measurement process shown in Figure 10 (step S105).

[0133] If the controller 3 determines that the voltage V1 of the first system 110 does not exceed the normal determination threshold (step S301, No), it clears the count value Tm13 of the normal duration timer for the first system 110 (step S303). In other words, the controller 3 sets the count value Tm13 of the normal duration timer for the first system 110 to "0".

[0134] Next, the controller 3 determines whether the change in the voltage V1 of the first system 110 is from above the normal threshold to below the normal threshold (step S304). If the controller 3 determines that the change in the voltage V1 of the first system 110 is not from above the normal threshold to below the normal threshold (step S304, No), the process moves to step S306.

[0135] If the controller 3 determines that the change in the voltage V1 of the first system 110 is a change from above the normal judgment threshold to below the normal judgment threshold (step S304, Yes), it increments the count value Ct12 of the cumulative number of abnormalities of the first system 110 (step S305). In other words, the controller 3 adds "1" to the count value Ct12 of the cumulative number of abnormalities of the first system 110.

[0136] Next, the controller 3 increments the count value Tm14 of the abnormal cumulative time timer for the first system 110 (step S306), and terminates the normal measurement process for the first system. After that, the controller 3 moves the process to the ground fault measurement process for the second system shown in Figure 10 (step S105).

[0137] [8-4. Ground fault measurement processing for the second system] Referring to Figure 13, the second system ground fault measurement process will be described. As shown in Figure 13, when the controller 3 starts the second system ground fault measurement process, it determines whether the voltage V2 of the second system 120 detected by the second voltage sensor 52 is below an abnormality determination threshold (step S401). The controller 3 may be configured to determine whether the voltage V2 of the second system 120 detected by the second voltage sensor 52 is below an abnormality determination threshold instead of the process in step S401.

[0138] If controller 3 determines that the voltage V2 of the second system 120 is not below the abnormality detection threshold (step S401, No), it clears the count value Tm21 of the abnormality duration timer for the second system 120 (step S406).

[0139] In other words, controller 3 sets the count value Tm21 of the abnormal duration timer for the second system 120 to "0" and terminates the second system ground fault measurement process. After that, controller 3 moves the process to the second system normal measurement process (step S106) shown in Figure 10.

[0140] If the controller 3 determines that the voltage V2 of the second system 120 is below the abnormality detection threshold (step S401, Yes), it determines whether the change in the voltage V2 of the second system 120 is a change from above the abnormality detection threshold to below the abnormality detection threshold (step S402).

[0141] If the controller 3 determines that the change in voltage V2 of the second system 120 is not a change from above the abnormality detection threshold to below the abnormality detection threshold (step S402, No), it moves the process to step S404.

[0142] If the controller 3 determines that the change in the voltage V2 of the second system 120 is from above the abnormality detection threshold to below the abnormality detection threshold (step S402, Yes), it moves the process to step S403. In step S403, the controller 3 increments the count value Ct21 of the cumulative abnormality count counter for the second system 120. That is, the controller 3 adds "1" to the count value Ct21 of the cumulative abnormality count counter for the second system 120.

[0143] Next, the controller 3 increments the count value Tm21 of the abnormal duration timer for the second system 120 (step S404). Then, the controller 3 increments the count value Tm22 of the abnormal cumulative time timer for the second system 120 (step S405), and terminates the second system ground fault measurement process. After that, the controller 3 moves the process to the second system normal measurement process shown in Figure 10 (step S106).

[0144] [8-5. Second System Normal Measurement Processing] Referring to Figure 14, the second system normal measurement process will be described. As shown in Figure 14, when the controller 3 starts the second system normal measurement process, it determines whether the voltage V2 of the second system 120 detected by the second voltage sensor 52 exceeds the normal determination threshold (step S501). The controller 3 may be configured to determine whether the voltage V2 of the second system 120 detected by the second voltage sensor 52 is equal to or greater than the normal determination threshold instead of the process in step S501.

[0145] If the controller 3 determines that the voltage V2 of the second system 120 exceeds the normal determination threshold (step S501, Yes), it increments the count value Tm23 of the normal duration timer for the second system 120 (step S502) and terminates the normal measurement process for the second system. After that, the controller 3 moves the process to the abnormal determination process shown in Figure 10 (step S107).

[0146] If controller 3 determines that the voltage V2 of the second system 120 does not exceed the normal determination threshold (step S501, No), it clears the count value Tm23 of the normal duration timer for the second system 120 (step S503). In other words, controller 3 sets the count value Tm23 of the normal duration timer for the second system 120 to "0".

[0147] Next, the controller 3 determines whether the change in voltage V1 of the second system 120 is from above the normal threshold to below the normal threshold (step S504). If the controller 3 determines that the change in voltage V2 of the second system 120 is not from above the normal threshold to below the normal threshold (step S504, No), the process moves to step S506.

[0148] If the controller 3 determines that the change in the voltage V2 of the second system 120 is a change from above the normal judgment threshold to below the normal judgment threshold (step S504, Yes), it increments the count value Ct22 of the cumulative number of abnormalities of the second system 120 (step S505). In other words, the controller 3 adds "1" to the count value Ct22 of the cumulative number of abnormalities of the second system 120.

[0149] Next, controller 3 increments the count value Tm24 of the abnormal cumulative time timer for the second system 120 (step S506), and terminates the normal measurement process for the second system. After that, controller 3 moves the process to the abnormal confirmation process shown in Figure 10 (step S107).

[0150] [8-6. Abnormality Confirmation Processing] The abnormality determination process will be explained with reference to Figures 15 and 16. As shown in Figure 15, when the controller 3 starts the abnormality determination process, it determines whether the count value Tm11 of the abnormality duration timer of the first system 110 is equal to or greater than the abnormality determination time (step S601).

[0151] If controller 3 determines that the count value Tm11 of the abnormal duration timer for the first system 110 is not equal to or greater than the abnormal confirmation time (step S601, No), it moves the process to step S604.

[0152] If the controller 3 determines that the count value Tm11 of the abnormal duration timer for the first system 110 is equal to or greater than the abnormal confirmation time (step S601, Yes), it confirms that the first system 110 is an abnormal system (step S602).

[0153] Next, the controller 3 notifies the higher-level ECU that the first system 110 is an abnormal system (step S603). The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as the central ECU that controls the entire vehicle.

[0154] Next, the controller 3 determines whether the count value Tm21 of the abnormal duration timer of the second system 120 is equal to or greater than the abnormal confirmation time (step S604). If it is determined that the count value Tm21 of the abnormal duration timer of the second system 120 is not equal to or greater than the abnormal confirmation time (step S604, No), the process shown in Figure 16 is moved to step S608.

[0155] If the controller 3 determines that the count value Tm21 of the abnormal duration timer for the second system 120 is equal to or greater than the abnormal confirmation time (step S604, Yes), it confirms that the second system 120 is an abnormal system (step S605).

[0156] Next, the controller 3 notifies the higher-level ECU that the second system 120 is an abnormal system (step S606). The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as the central ECU that controls the entire vehicle.

[0157] Next, the controller 3 turns off the battery switch 42 (step S607) and moves the process to step S608 shown in Figure 16. In step S608, the controller 3 determines whether the count value Tm13 of the normal duration timer of the first system 110 is equal to or greater than the normal confirmation time.

[0158] If controller 3 determines that the count value Tm13 of the normal duration timer for the first system 110 is not equal to or greater than the normal confirmation time (step S608, No), it moves the process to step S610. If controller 3 determines that the count value Tm13 of the normal duration timer for the first system 110 is equal to or greater than the normal confirmation time (step S608, Yes), it confirms that the first system 110 is a normal system (step S609).

[0159] Next, controller 3 determines whether the count value Tm23 of the normal duration timer of the second system 120 is equal to or greater than the normal confirmation time (step S610). If controller 3 determines that the count value Tm23 of the normal duration timer of the second system 120 is not equal to or greater than the normal confirmation time (step S610, No), it moves the process to step S612.

[0160] If the controller 3 determines that the count value Tm23 of the normal duration timer for the second system 120 is equal to or greater than the normal confirmation time (step S610, Yes), it confirms that the second system 120 is normal (step S611).

[0161] The controller 3 determines whether both the first system 110 and the second system 120 are confirmed to be normal systems (step S612). If the controller 3 determines that both systems are confirmed to be normal systems (step S612, Yes), it turns on the inter-system switch 41 and turns off the battery switch 42 (step S613). As a result, the power control device 1 returns to its normal state.

[0162] If controller 3 determines that one or both of the two systems are not confirmed to be normal systems (step S612, No), it terminates the abnormality confirmation process. After that, controller 3 moves the process to step S108 shown in Figure 10.

[0163] [8-7. Anomaly Estimation Processing] The abnormality estimation process will be explained with reference to Figures 17 and 18. As shown in Figure 17, when the controller 3 starts the abnormality estimation process, it determines whether it is undetermined whether both the first system 110 and the second system 120 are abnormal systems or normal systems (step S701). That is, the controller 3 determines whether it is undetermined whether the first system 110 is normal or abnormal, and whether it is undetermined whether the second system 120 is normal or abnormal. If the controller 3 determines that either or both of the two systems are not undetermined (step S701, No), the process moves to step S715 shown in Figure 18.

[0164] If controller 3 determines that both systems are undecided (step S701, Yes), it moves the process to step S702. In step S702, controller 3 determines whether the absolute difference between the count value Tm12 of the abnormal cumulative time timer of the first system 110 and the count value Tm22 of the abnormal cumulative time timer of the second system 120 is greater than the statistical significance α (step 702). The statistical significance α can be set to any value by simulation or testing.

[0165] If controller 3 determines that the absolute value is greater than the statistically significant difference α (step S702, Yes), it moves the process to step S703. In step S703, controller 3 determines whether the count value Tm12 of the abnormal cumulative time timer of the first system 110 is greater than the count value Tm22 of the abnormal cumulative time timer of the second system 120.

[0166] If the controller 3 determines that the count value Tm12 of the abnormal cumulative time timer for the first system 110 is greater than the count value Tm22 of the abnormal cumulative time timer for the second system 120 (step S703, Yes), it moves the process to step S704. In step S704, the controller 3 estimates the first system 110 as an abnormal system.

[0167] Next, the controller 3 notifies the higher-level ECU that the first system 110 is an abnormal system (step S705). The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as the central ECU that controls the entire vehicle. Next, the controller 3 moves the process to step S715 shown in Figure 18.

[0168] On the other hand, if the controller 3 determines in step S703 that the count value Tm12 of the abnormal cumulative time timer of the first system 110 is not greater than the count value Tm22 of the abnormal cumulative time timer of the second system 120 (step S703, No), it moves the process to step S706.

[0169] In step S706, the controller 3 estimates that the second system 120 is an abnormal system. Next, the controller 3 turns off the battery switch 42 (step S707). Then, the controller 3 notifies the higher-level ECU that the second system 120 is an abnormal system (step S708).

[0170] The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as a central ECU that controls the entire vehicle. The controller 3 then moves the process to step S715 shown in Figure 18.

[0171] If, in step S702, the controller 3 determines that the absolute difference between the count value Tm12 of the abnormal cumulative time timer of the first system 110 and the count value Tm22 of the abnormal cumulative time timer of the second system 120 is not greater than a statistically significant difference α (step S702, No), the process moves to step S709.

[0172] In step S709, the controller 3 determines whether the count value Tm14 of the abnormal cumulative time timer of the first system 110 is greater than the count value Tm24 of the abnormal cumulative time timer of the second system 120.

[0173] If the controller 3 determines that the count value Tm14 of the abnormal cumulative time timer for the first system 110 is greater than the count value Tm24 of the abnormal cumulative time timer for the second system 120 (step S709, Yes), it moves the process to step S710. In step S710, the controller 3 estimates the first system 110 as an abnormal system.

[0174] Next, the controller 3 notifies the higher-level ECU that the first system 110 is an abnormal system (step S711). The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as the central ECU that controls the entire vehicle. Next, the controller 3 moves the process to step S715 shown in Figure 18.

[0175] If, in step S709, the controller 3 determines that the count value Tm14 of the abnormal cumulative time timer of the first system 110 is not greater than the count value Tm24 of the abnormal cumulative time timer of the second system 120 (step S709, No), the process moves to step S712.

[0176] In step S712, the controller 3 estimates the second system 120 to be an abnormal system. Next, the controller 3 turns off the battery switch 42 (step S713). Then, the controller 3 notifies the higher-level ECU that the second system 120 is an abnormal system (step S714).

[0177] The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as a central ECU that controls the entire vehicle. The controller 3 then moves the process to step S715 shown in Figure 18.

[0178] In step S715, the controller 3 determines whether it has determined that the state of the first system 110 is definitely abnormal and that the state of the second system 120 is undetermined. If the controller 3 has not determined that the state of the first system 110 is definitely abnormal and has not determined that the state of the second system 120 is undetermined (step S715, No), the process moves to step S717.

[0179] If the controller 3 determines that the state of the first system 110 is definitely abnormal and the state of the second system 120 is undetermined (step S715, Yes), it notifies the automatic driving control device 100 that it will take evasive action on the second system 120 (step S716).

[0180] Next, controller 3 determines whether it has determined the state of the first system 110 to be undetermined and the state of the second system 120 to be definitely abnormal (step S717). If controller 3 does not determine the state of the first system 110 to be undetermined and does not determine the state of the second system 120 to be definitely abnormal (step S717, No), the process moves to step S719.

[0181] If the controller 3 determines that the state of the first system 110 is undetermined and the state of the second system 120 is confirmed to be abnormal (step S717, Yes), it notifies the automatic driving control device 100 that it will take evasive action on the first system 110 (step S718).

[0182] Next, the controller 3 determines whether it has estimated the state of the first system 110 to be normal and the state of the second system 120 to be undetermined (step S719). If the controller 3 determines that it has estimated the state of the first system 110 to be normal and has not estimated the state of the second system 120 to be undetermined (step S719, No), the process moves to step S722.

[0183] If the controller 3 determines that the state of the first system 110 is normal and the state of the second system 120 is undetermined (step S719, Yes), it turns off the battery switch 42 (step S720). Next, the controller 3 notifies the automatic driving control device 100 that it will take evasive action using the first system 110 (step S721).

[0184] Next, the controller 3 determines whether it has estimated the state of the first system 110 to be undetermined and the state of the second system 120 to be normal (step S722). If the controller 3 determines that it has not estimated the state of the first system 110 to be undetermined and the state of the second system 120 to be normal (step S722, No), it terminates the abnormality estimation process.

[0185] If the controller 3 determines that the state of the first system 110 is undetermined and the state of the second system 120 is normal (step S722, Yes), it notifies the automatic driving control device 100 to take evasive action on the second system 120 (step S723) and terminates the abnormality estimation process.

[0186] The process shown in Figure 17 is an example and can be changed. Controller 3 can omit steps S702 and S709-S714. In this case, if Controller 3 determines that both systems are undecided (step S701, Yes), it moves the process to step S703.

[0187] Controller 3 can skip the processing in steps S702 to S708. In this case, if Controller 3 determines that both systems are undecided (step S701, Yes), it moves the process to step S709.

[0188] [8-8. Variations of Anomaly Estimation Processing] Referring to Figure 19, the abnormality estimation process for the modified example will be explained. As shown in Figure 19, when the controller 3 starts the abnormality estimation process for the modified example, it determines whether it is undetermined whether both the first system 110 and the second system 120 are abnormal systems or normal systems (step S801). If the controller 3 determines that either one or both of the two systems are not undetermined (step S801, No), it moves the process to step S715 shown in Figure 18.

[0189] If controller 3 determines that both systems are undecided (step S801, Yes), it moves the process to step S802. In step S802, controller 3 determines whether the absolute value of the difference between the count value Ct11 of the cumulative number of abnormal events counter for the first system 110 and the count value Ct21 of the cumulative number of abnormal events counter for the second system 120 is greater than 0 (step 802).

[0190] If controller 3 determines that the absolute value is greater than 0 (step S802, Yes), it moves the process to step S803. In step S803, controller 3 determines whether the count value Ct11 of the cumulative number of abnormal occurrences counter of the first system 110 is greater than the count value Ct21 of the cumulative number of abnormal occurrences counter of the second system 120.

[0191] If the controller 3 determines that the count value Ct11 of the cumulative number of abnormal events counter for the first system 110 is greater than the count value Ct21 of the cumulative number of abnormal events counter for the second system 120 (step S803, Yes), it moves the process to step S804. In step S804, the controller 3 estimates the first system 110 as an abnormal system.

[0192] Next, the controller 3 notifies the higher-level ECU that the first system 110 is an abnormal system (step S805). The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as the central ECU that controls the entire vehicle. Next, the controller 3 moves the process to step S715 shown in Figure 18.

[0193] On the other hand, if the controller 3 determines in step S803 that the count value Ct11 of the cumulative number of abnormal events counter of the first system 110 is not greater than the count value Ct21 of the cumulative number of abnormal events counter of the second system 120 (step S803, No), it moves the process to step S806.

[0194] In step S806, the controller 3 estimates that the second system 120 is an abnormal system. Next, the controller 3 turns off the battery switch 42 (step S807). Then, the controller 3 notifies the higher-level ECU that the second system 120 is an abnormal system (step S808).

[0195] The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as a central ECU that controls the entire vehicle. The controller 3 then moves the process to step S715 shown in Figure 18.

[0196] If, in step S802, the controller 3 determines that the absolute value of the difference between the count value Ct11 of the cumulative number of abnormal occurrences counter for the first system 110 and the count value Ct21 of the cumulative number of abnormal occurrences counter for the second system 120 is not greater than 0 (step S802, No), the process moves to step S809.

[0197] In step S809, the controller 3 determines whether the count value Ct12 of the cumulative number of abnormal events counter of the first system 110 is greater than the count value Ct22 of the cumulative number of abnormal events counter of the second system 120.

[0198] If the controller 3 determines that the count value Ct12 of the cumulative number of abnormal events counter for the first system 110 is greater than the count value Ct22 of the cumulative number of abnormal events counter for the second system 120 (step S809, Yes), it moves the process to step S810. In step S810, the controller 3 estimates the first system 110 as an abnormal system.

[0199] Next, the controller 3 notifies the higher-level ECU that the first system 110 is an abnormal system (step S811). The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be any other ECU, such as the central ECU that controls the entire vehicle. Next, the controller 3 moves the process to step S715 shown in Figure 18.

[0200] If the controller 3 determines in step S809 that the count value Ct12 of the cumulative number of abnormal events counter for the first system 110 is not greater than the count value Ct22 of the cumulative number of abnormal events counter for the second system 120 (step S809, No), it moves the process to step S812.

[0201] In step S812, the controller 3 estimates that the second system 120 is an abnormal system. Next, the controller 3 turns off the battery switch 42 (step S813). Then, the controller 3 notifies the higher-level ECU that the second system 120 is an abnormal system (step S814).

[0202] The higher-level ECU is the automatic driving control device 100. The higher-level ECU may be another ECU, such as the central ECU that controls the entire vehicle. Next, the controller 3 moves the process to step S715 shown in Figure 18. After that, the controller 3 executes the processes in steps S715 to S723 shown in Figure 18 and terminates the abnormality estimation process.

[0203] The process shown in Figure 19 is an example and can be changed. Controller 3 can omit steps S802 and S809-S814. In this case, if Controller 3 determines that both systems are undecided (step S801, Yes), it moves the process to step S803.

[0204] Controller 3 can skip the processing in steps S802 to S808. In this case, if Controller 3 determines that both systems are undecided (step S801, Yes), it moves the process to step S809.

[0205] [9. Power supply control device relating to a modified example] Figure 20 is an explanatory diagram of the configuration and operation of a power control device according to a modified embodiment. As shown in Figure 20, the power control device 1A is connected to the first load 101, the general load 102, and the second load 103, as well as the third load 104 and the fourth load 105.

[0206] A first load switch 43 is provided between the second system 120 and the second load 103. A second load switch 44 is provided between the second system 120 and the third load 104. A third load switch 45 is provided between the second system 120 and the fourth load 105.

[0207] If the controller 3 determines or estimates the second system 120 as an abnormal system through the confirmation or estimation process described above, it turns off and then on the first to third load switches 43 to 45 one by one, starting from a state where all of them are on.

[0208] If the voltage of the second system 120, detected by the second voltage sensor 52 when one of the first to third load switches 43 to 45 is turned off, the controller 3 determines that the load side of the turned-off load switch is experiencing a ground fault. The controller 3 then turns off the load switch that it has determined to have a ground fault on its load side.

[0209] As a result, when the controller 3 determines or estimates that the second system 120 is an abnormal system, it can allow the operation of the loads among the second to fourth loads 103 to 105 connected to the second system 120 that are not related to the ground fault to continue.

[0210] [10. Addendum] As an addendum, the features of the present invention are as follows. (1) A power control device comprising a connecting device provided in an inter-system line connecting a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load, and a controller that controls the connecting device, The aforementioned controller, When a power failure in the first or second system is detected, the connection device is controlled to disconnect the inter-system line, and a determination process is performed to determine which system has failed based on the changes in the voltage of the first system and the voltage of the second system during the first period. If the system that has failed cannot be determined by the confirmation process, an estimation process is performed to estimate the system that is strongly suspected of being abnormal as the abnormal system, based on the changes in the voltage of the first system and the voltage of the second system during a second period that is longer than the first period. Power supply control device. (2) The aforementioned controller, The cumulative time during which the voltage of the first system is below the abnormality threshold and the cumulative time during which the voltage of the second system is below the abnormality threshold are measured, and the system with the longer cumulative time is estimated to be the abnormal system. (1) The power control device described above. (3) The aforementioned controller, The cumulative time during which the voltage of the first system is below the normal threshold and the cumulative time during which the voltage of the second system is below the normal threshold are measured, and the system with the longer cumulative time is estimated to be the abnormal system. The power control device described in (1) or (2). (4) The aforementioned controller, The cumulative time during which the voltage of the first system is below the abnormality detection threshold and the cumulative time during which the voltage of the second system is below the abnormality detection threshold are measured. The cumulative time during which the voltage of the first system is below the normal threshold and the cumulative time during which the voltage of the second system is below the normal threshold are measured. Systems with a long cumulative time below the abnormality threshold are estimated as abnormal systems. If the estimation process does not allow for the estimation of an abnormal system, systems with a long cumulative time below the normality threshold are estimated as abnormal systems. (1) The power control device described above. (When the times for both systems are the same or the time difference is within the margin of error) (5) The aforementioned controller, The number of times the voltage of the first system falls below the abnormality detection threshold and the number of times the voltage of the second system falls below the abnormality detection threshold are measured. The system with the most occurrences is estimated to be the abnormal system. (1) The power control device described above. (6) The aforementioned controller, The number of times the voltage of the first system falls below the normal threshold and the number of times the voltage of the second system falls below the normal threshold are measured, and the system with fewer occurrences is estimated to be the abnormal system. (1) or (5) the power supply control device. (7) The aforementioned controller, The number of times the voltage of the first system falls below the abnormality detection threshold and the number of times the voltage of the second system falls below the abnormality detection threshold are measured. The number of times the voltage of the first system falls below the normal threshold and the number of times the voltage of the second system falls below the normal threshold are measured. A system that has frequently fallen below the abnormality threshold is estimated to be the abnormal system. If the system cannot be estimated as an abnormal system by the estimation process, a system that has a small number of times fallen below the normality threshold is estimated to be the abnormal system. (1) The power control device described above. (8) The aforementioned controller, If a strain strongly suspected of being abnormal is estimated to be a lost strain, the confirmation process and estimation process described above shall be repeated. A power control device as described in any one of (1) through (7). (9) A power control device having a connection device provided in an inter-system line connecting a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load, and a controller that controls the connection device, the controller of the power control device, When a power failure in the first or second system is detected, the connection device is controlled to disconnect the inter-system line, and a determination process is performed to determine which system has failed based on the changes in the voltage of the first system and the voltage of the second system during the first period. If the system that has failed cannot be determined by the confirmation process, an estimation process is performed to estimate the system that is strongly suspected of being abnormal as the abnormal system, based on the changes in the voltage of the first system and the voltage of the second system during a second period that is longer than the first period. Power control method.

[0211] 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]

[0212] 1.1A Power Supply Control Device 3 Controllers 10 1st power supply 20 2nd power supply 41 Inter-system switches 42 Battery Switch 43. First load switch 44. Second load switch 45. Third load switch 51. First voltage sensor 52 Second Voltage Sensor 100 Automatic Driving Control System 101 1st load 102 General load 103 2nd load 104 Third load 105 4th load 110 1st system 120 2nd system 130 Inter-system lines

Claims

1. A power control device comprising a connecting device provided in an inter-system line connecting a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load, and a controller that controls the connecting device, The aforementioned controller, When a power failure in the first or second system is detected, the connection device is controlled to disconnect the line between the systems, and a determination process is performed to determine which system has failed based on the changes in the voltage of the first system and the voltage of the second system during the first period. If the system that has failed cannot be determined by the confirmation process, an estimation process is performed to estimate the system that is strongly suspected of being abnormal as the abnormal system, based on the changes in the voltage of the first system and the voltage of the second system during a second period that is longer than the first period. Power supply control device.

2. The aforementioned controller, The cumulative time during which the voltage of the first system is below the abnormality threshold and the cumulative time during which the voltage of the second system is below the abnormality threshold are measured, and the system with the longer cumulative time is estimated to be the abnormal system. The power control device according to claim 1.

3. The aforementioned controller, The cumulative time during which the voltage of the first system is below the normal threshold and the cumulative time during which the voltage of the second system is below the normal threshold are measured, and the system with the longer cumulative time is estimated to be the abnormal system. The power control device according to claim 1.

4. The aforementioned controller, The cumulative time during which the voltage of the first system is below the abnormality detection threshold and the cumulative time during which the voltage of the second system is below the abnormality detection threshold are measured. The cumulative time during which the voltage of the first system is below the normal threshold and the cumulative time during which the voltage of the second system is below the normal threshold are measured. Systems with a long cumulative time below the abnormality threshold are estimated as abnormal systems. If the estimation process does not allow for the estimation of an abnormal system, systems with a long cumulative time below the normality threshold are estimated as abnormal systems. The power control device according to claim 1.

5. The aforementioned controller, The number of times the voltage of the first system falls below the abnormality detection threshold and the number of times the voltage of the second system falls below the abnormality detection threshold are measured. The system with the most occurrences is estimated to be the abnormal system. The power control device according to claim 1.

6. The aforementioned controller, The number of times the voltage of the first system falls below the normal threshold and the number of times the voltage of the second system falls below the normal threshold are measured, and the system with fewer occurrences is estimated to be the abnormal system. The power control device according to claim 1.

7. The aforementioned controller, The number of times the voltage of the first system falls below the abnormality detection threshold and the number of times the voltage of the second system falls below the abnormality detection threshold are measured. The number of times the voltage of the first system falls below the normal threshold and the number of times the voltage of the second system falls below the normal threshold are measured. A system that has frequently fallen below the abnormality threshold is estimated to be the abnormal system. If the system cannot be estimated as an abnormal system by the estimation process, a system that has a small number of times fallen below the normality threshold is estimated to be the abnormal system. The power control device according to claim 1.

8. The aforementioned controller, If a strain strongly suspected of being abnormal is estimated to be a lost strain, the confirmation process and estimation process described above shall be repeated. The power control device according to claim 1.

9. A power control device having a connection device provided in an inter-system line connecting a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load, and a controller that controls the connection device, the controller of the power control device When a power failure in the first or second system is detected, the connection device is controlled to disconnect the line between the systems, and a determination process is performed to determine which system has failed based on the changes in the voltage of the first system and the voltage of the second system during the first period. If the system that has failed cannot be determined by the confirmation process, an estimation process is performed to estimate the system that is strongly suspected of being abnormal as the abnormal system, based on the changes in the voltage of the first system and the voltage of the second system during a second period that is longer than the first period. Power control method.

Images