Power control device

Abstract

To provide a power supply control unit that can detect open fastening of an inter-system switch.SOLUTION: A power supply control unit 1 comprises: a first system 110 that supplies power to a first load 101; a second system 120 that supplies power to a second load 103; an inter-system switch 41 that can connect the first system and the second system to each other and cut off the systems from each other; a switch 42 for a battery that can connect a second power supply 21 and the second system to each other and cut off the power supply and the system from each other; a primary ground fault detection unit 31; a secondary ground fault detection unit 32; and a failure determination unit 33. When the primary ground fault detection unit detects the ground fault of the first system or the second system, it cuts off the inter-system switch and conducts the switch for a battery. The secondary ground fault detection unit specifies the system in which the ground fault is detected, and if the ground fault is resolved, performs restoration control of reconnecting the inter-system switch and cutting off the switch for a battery. When the frequency of repetition of the restoration control and ground fault detection after the detection of the ground fault is equal to or more than a predetermined frequency, the failure determination unit determines the occurrence of open fastening of the inter-system switch.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

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

[0003] When the power control device detects that the voltage of the first system or the second system has dropped below the ground fault determination threshold, it shuts off the inter-system switch to identify the grounded system. Thereafter, if the voltages of the first system and the second system return above the ground fault within a predetermined time, the power control device determines that it is normal, reconnects the inter-system switch, and returns to normal control (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the inter-system switch is stuck open, the power control device cannot charge the second power source, so the SOC (State Of Charge) of the second power source may be insufficient and the desired backup may not be achievable. Therefore, the power control device needs to detect the stuck open state of the inter-system switch.

[0006] One aspect of the embodiment has been made in view of the above, and an object thereof is to provide a power control device capable of detecting a stuck open state of an inter-system switch.

Means for Solving the Problems

[0007] A power control device according to an aspect of the embodiment includes a first system, a second system, an inter-system switch, a battery switch, a primary ground fault detection unit, a secondary ground fault detection unit, and a fault determination unit. The first system supplies the power of the first power source to the first load. The second system supplies the power of the second power source to the second load. The inter-system switch can connect and disconnect the first system and the second system. The battery switch can connect and disconnect the second power source and the second system. When the primary ground fault detection unit detects a ground fault in the first system or the second system, it shuts off the inter-system switch and conducts the battery switch. When the secondary ground fault detection unit detects a ground fault by the primary ground fault detection unit, it identifies whether the system in which the ground fault is detected is the first system or the second system, and if the ground fault has been eliminated, it performs a return control of reconnecting the inter-system switch and shutting off the battery switch. When the frequency at which the return control and the ground fault detection by the primary ground fault detection unit are repeated after the ground fault is detected by the primary ground fault detection unit is equal to or higher than a predetermined frequency, the fault determination unit determines that the inter-system switch is stuck open.

Advantages of the Invention

[0008] The power control device according to an aspect of the embodiment can detect the stuck-open state of the inter-system switch. It has the effect of being able to do so.

Brief Description of the Drawings

[0009]

Figure 1

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Figure 10

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the power control device and the 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. In the following, 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. However, the power control device according to the embodiment may be mounted on a vehicle not having an automatic driving function.

[0011] In addition, in the following, the case where the vehicle on which the power control device is mounted is an electric vehicle or a hybrid vehicle will be described. However, the vehicle on which the power control device is mounted may be an engine vehicle that runs by an internal combustion engine.

[0012] Note that the power control device according to the embodiment includes a first power source and a second power source, and when a power failure occurs in either one of the power source systems of the first power source and the second power source, the first power source is backed up by the other power source system, and it may be mounted on any device.

[0013] [1. Configuration of Power Control Device] FIG. 1 is an explanatory diagram showing a configuration example of a power control device according to an embodiment. As shown in FIG. 1, a power control device 1 according to an 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. The power control device 1 includes a first system 110 that supplies the power of the first power source 10 to the first load 101 and the general load 102, and a second system 120 that supplies the power of a second power source 20, which will be described later, to the second load 103.

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

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

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

[0017] The first power source 10 includes a DC / DC converter (hereinafter referred to as "DC / DC11") and a lead battery (hereinafter referred to as "PbB12"). Note that the battery of the first power source 10 may be any secondary battery other than PbB12.

[0018] DC / DC 11 is connected to a generator and a high-voltage battery with a voltage higher than that of PbB 12, steps down the voltages of the generator and the high-voltage battery, and outputs them to the first system 110. The generator is, for example, an alternator that converts the kinetic energy of a traveling vehicle into electricity to generate power. The high-voltage battery is, for example, a vehicle drive battery mounted on an electric vehicle or a hybrid vehicle.

[0019] Note that when the first power source 10 is mounted on an engine vehicle, an alternator (generator) is provided instead of DC / DC 11. DC / DC 11 performs charging of PbB 12, power supply to the first load 101 and the general load 102, power supply to the second load 103, and charging of the second power source 20 described later.

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

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

[0022] The first voltage sensor 51 is provided in the first system 110, detects the voltage of the first system 110, and outputs the detection result to the switch driving unit 3. The second voltage sensor 52 is provided in the second system 120, detects the voltage of the second system 120, and outputs the detection result to the switch driving unit 3.

[0023] The switch driving unit 3 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and various circuits. Note that the switch driving unit 3 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0024] The switch driving unit 3 includes a primary ground fault detection unit 31, a secondary ground fault detection unit 32, and a fault determination unit 33 that function by the CPU executing a program stored in the ROM using the RAM as a work area, and controls the operation of the power control device 1.

[0025] The primary ground fault detection unit 31 detects a ground fault in the first system 110 or the second system 120 by hardware (for example, a comparator). Therefore, the primary ground fault detection unit 31 can quickly detect a ground fault. When the primary ground fault detection unit 31 detects a ground fault in the first system 110 or the second system 120, it cuts off the inter-system switch 41 and conducts the battery switch 42.

[0026] The secondary ground fault detector 32 detects the ground fault of the first system 110 or the second system 120 by software. Therefore, the speed at which the secondary ground fault detector 32 detects the ground fault is slower than the ground fault detection speed by the primary ground fault detector 31 due to the influence of the AD conversion of the output voltages of the first voltage sensor 51 and the second voltage sensor 52. When the primary ground fault detector 31 detects a ground fault, the secondary ground fault detector 32 identifies whether the system in which the ground fault is detected is the first system 110 or the second system 120, and if the ground fault has been eliminated, it performs a return control of reconnecting the inter-system switch 41 and disconnecting the battery switch 42.

[0027] The fault determination unit 33 determines the open fixation of the inter-system switch 41. A specific configuration example of the switch drive unit 3 will be described later with reference to FIG. 9. When activated, the switch drive unit 3 connects (turns on) the inter-system switch 41 and disconnects (turns off) the battery switch 42.

[0028] The switch drive unit 3 detects the ground fault of 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 switch drive unit 3 will be described later.

[0029] When the switch drive unit 3 detects a ground fault in the first system 110 or the second system 120, it notifies the automatic operation control device 100 to that effect. When the switch drive unit 3 detects a ground fault in the first system 110 or the second system 120, it outputs an automatic operation prohibition signal indicating that the automatic operation is impossible to the automatic operation control device 100. Further, when the switch drive unit 3 does not detect a ground fault in the first system 110 or the second system 120, it outputs an automatic operation permission signal indicating that the automatic operation is possible to the automatic operation control device 100.

[0030] When a power failure such as a ground fault occurs in the first system 110, the switch driving unit 3 disconnects the inter-system switch 41 and connects the battery switch 42 to supply power from the second power source 20 to the second load 103. Further, when a power failure such as a ground fault occurs in the second system 120, the switch driving unit 3 disconnects the inter-system switch 41 and supplies power from the first power source 10 to the first load 101 and the general load 102 with the battery switch 42 being in the disconnected state.

[0031] As a result, even if either one of the systems experiences a ground fault during automatic driving, the power control device 1 can use the other system to implement the FOP of retreating the vehicle to a safe location by the automatic driving control device 100 and stopping the vehicle. Next, with reference to FIGS. 2 to 8, the operation of the power control device 1 will be described.

[0032] [2. Normal operation of the power control device] In the normal state where no ground fault has occurred in the first system 110 and the second system 120, as shown in FIG. 2, the switch driving unit 3 disconnects the battery switch 42 and connects the inter-system switch 41 to supply power from the first power source 10 to the first load 101, the general load 102, and the second load 103. In the normal state where no ground fault has occurred in this way, the switch driving unit 3 outputs an automatic driving permission signal to the automatic driving control device 100.

[0033] [3. Operation of the power control device when a ground fault occurs] Next, with reference to FIGS. 3 to 5, the operation of the power control device 1 when a ground fault occurs will be described. As shown in FIG. 3, in the power control device 1, for example, when a ground fault 200 occurs in the first system 110 or a ground fault 201 occurs in the second system 120, an overcurrent flows toward the ground fault point, so that the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 become equal to or lower than the ground fault determination threshold value.

[0034] Therefore, when the voltage detected by the second voltage sensor 52, for example, is equal to or lower than the ground fault determination threshold value, the switch driving unit 3 tentatively determines that a ground fault 200, 201 has occurred in the first system 110 or the second system 120, and outputs an automatic driving prohibition signal to the automatic driving control device 100. Then, when tentatively determining that a ground fault 200, 201 has occurred, the switch driving unit 3 disconnects the inter-system switch 41 and connects the battery switch 42. As a result, the connection between the first system 110 and the second system 120 is disconnected, 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.

[0035] Note that when the voltage detected by at least one of the first voltage sensor 51 or the second voltage sensor 52 is equal to or lower than the ground fault determination threshold value, the switch driving unit 3 can also tentatively determine that a ground fault has occurred in the first system 110 or the second system 120.

[0036] After that, when the voltage detected by the first voltage sensor 51 is equal to or lower than the ground fault determination threshold value for a predetermined time or more and the voltage detected by the second voltage sensor 52 returns above the ground fault determination threshold value within the predetermined time, the switch driving unit 3 makes a final determination that a ground fault 200 has occurred in the first system 110.

[0037] In this case, as shown in FIG. 4, the switch driving unit 3 supplies power from the second power source 20 to the second load 103 and notifies the automatic driving control device 100 to that effect. As a result, the automatic driving control device 100 can operate the second load 103 with the power supplied from the second power source 20 to cause the vehicle to perform an evacuation run to a safe location and stop. Note that the automatic driving control device 100 may be configured to start the evacuation run when an automatic driving prohibition signal is input from the power control device 1.

[0038] Further, after temporarily determining that a ground fault has occurred in the first system 110 or the second system 120, if the voltage detected by the second voltage sensor 52 is equal to or lower than the ground fault determination threshold even after a predetermined time has elapsed, and the voltage detected by the first voltage sensor 51 returns until it exceeds the ground fault determination threshold within the predetermined time, it is finally determined that a ground fault 201 has occurred in the second system 120.

[0039] In this case, as shown in FIG. 5, the switch driving unit 3 shuts off the battery switch 42, supplies power from the first power source 10 to the first load 101, and notifies the automatic driving control device 100 to that effect. As a result, the automatic driving control device 100 can operate the first load 101 with the power supplied from the first power source 10, and retreat and park the vehicle to a safe place. Note that the automatic driving control device 100 may be configured to start the retreat driving when an automatic driving prohibition signal is input from the power control device 1.

[0040] The switch driving unit 3 is also connected to the second power source 20 and monitors the voltage of the second power source 20 (SOC (State Of Charge) of the LiB21). When the voltage of the second power source 20 drops to or below a predetermined voltage, as shown in FIG. 6, the inter-system switch 41 and the battery switch 42 are turned on, and the second power source 20 is charged by the DC / DC 11.

[0041] [4. Problems in the case of open fixation of the inter-system switch] In the power control device 1, when the first load 101 or the general load 102 is temporarily in an overload state instead of the ground faults 200 and 201, the voltage detected by the first voltage sensor 51 may temporarily become equal to or lower than the ground fault determination threshold. Also, in the power control device 1, when the second load 103 is temporarily in an overload state, the voltage detected by the second voltage sensor 52 may temporarily become equal to or lower than the ground fault determination threshold.

[0042] In this case, in the power supply control device 1, power is continuously supplied from the first power supply 10 to the first load 101 and the general load 102, and power is supplied from the second power supply 20 to the second load 103. Therefore, after the switch driving unit 3 tentatively determines that a ground fault 200, 201 has occurred in the first system 110 or the second system 120, if it returns before a predetermined time elapses until the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 both exceed the ground fault determination threshold value, it determines that this is a transient voltage drop and there is no abnormality in the power supply. Thereafter, in order for the switch driving unit 3 to return to the normal operation shown in FIG. 2, the battery switch 42 is cut off and the inter-system switch 41 is connected again.

[0043] At this time, as shown in FIG. 7, when the inter-system switch 41 is stuck open, even if an attempt is made to cut off the battery switch 42 and reconnect the inter-system switch 41, the battery switch 42 can be cut off, but the inter-system switch 41 cannot be made conductive. For this reason, since the second system 120 is not supplied with power from the first power supply 10, the voltage drops to the ground fault determination threshold value.

[0044] As a result, the switch driving unit 3 tentatively determines that a ground fault 201 has occurred in the second system 120, and as shown in FIG. 8, cuts off the inter-system switch 41 and reconnects the battery switch 42. Thereby, power is supplied from the second power supply 20 to the second system 120, and the voltage of the second system 120 returns until it exceeds the ground fault determination threshold value.

[0045] Therefore, the switch driving unit 3 determines that this is a transient voltage drop and there is no abnormality in the power supply, and attempts to cut off the battery switch 42 and reconnect the inter-system switch 41 in order to return to the normal operation, but the state of the power supply control device 1 returns to the state of FIG. 7. Thus, when the inter-system switch 41 is stuck open, the power supply control device 1 alternately repeats the state shown in FIG. 7 and the state shown in FIG. 8. That is, the power supply control device 1 repeatedly cuts off and reconnects the battery switch 42.

[0046] At this time, while the battery switch 42 is conducting, the power supply control device 1 consumes the power of the second power supply 20. However, since the inter-system switch 41 is open-stuck, the inter-system switch 41 and the battery switch 42 cannot be conducted to charge the second power supply 20. Therefore, the switch driving unit 3 of the power supply control device 1 according to the embodiment includes a failure determination unit 33 that detects the open-stuck of the inter-system switch 41.

[0047] [5. Configuration example of the switch driving unit according to the embodiment] Next, with reference to FIG. 9, a configuration example of the switch driving unit 3 according to the embodiment will be described. FIG. 9 is an explanatory diagram showing a configuration example of the switch driving unit 3 according to the embodiment.

[0048] As shown in FIG. 9, the switch driving unit 3 includes a primary ground fault detection unit 31, a secondary ground fault detection unit 32, a failure determination unit 33, an OR logic circuit 34, and an OR logic circuit 35. The detection results of the voltages of the first system 110 from the first voltage sensor 51 and the detection results of the voltages of the second system 120 from the second voltage sensor 52 are input to the primary ground fault detection unit 31 and the secondary ground fault detection unit 32.

[0049] When the primary ground fault detection unit 31 detects a ground fault in the first system 110 or the second system 120, it shuts off the inter-system switch 41 and conducts the battery switch 42. Specifically, when the voltage of the first system 110 or the voltage of the second system 120 becomes equal to or lower than the ground fault determination threshold value, the primary ground fault detection unit 31 outputs a primary ground fault detection signal to the secondary ground fault detection unit 32, the OR logic circuit 34, and the OR logic circuit 35. At this time, the primary ground fault detection unit 31 outputs, for example, a primary ground fault detection signal of a 50 ms one-shot pulse. When the secondary ground fault detection unit 32 receives the primary ground fault detection signal from the primary ground fault detection unit 31, it outputs a secondary ground fault detection signal to the OR logic circuit 34, the OR logic circuit 35, and the failure determination unit 33.

[0050] When a primary ground fault detection signal from the primary ground fault detection unit 31 or a secondary ground fault detection signal from the secondary ground fault detection unit 32 is input to the OR logic circuit 35, the OR logic circuit 35 outputs a cutoff signal to the inter-system switch 41 to cut off the inter-system switch 41. Also, when a primary ground fault detection signal from the primary ground fault detection unit 31 or a secondary ground fault detection signal from the secondary ground fault detection unit 32 is input to the OR logic circuit 34, the OR logic circuit 34 outputs a control signal to the battery switch 42 to turn on the battery switch 42.

[0051] That is, since the primary ground fault detection unit 31 has a faster detection speed than the secondary ground fault detection unit 32, when the voltage of the first system 110 or the second system 120 drops, the primary ground fault detection signal from the primary ground fault detection unit 31 immediately cuts off the inter-system switch 41 and turns on the battery switch 42. Thereafter, the secondary ground fault detection signal from the secondary ground fault detection unit 32 will continue to cut off the inter-system switch 41 and turn on the battery switch 42.

[0052] Also, when a ground fault is detected by the primary ground fault detection unit 31, the secondary ground fault detection unit 32 identifies whether the system in which the ground fault is detected is the first system 110 or the second system 120. If the ground fault has been eliminated, the secondary ground fault detection unit 32 performs a return control to reconnect the inter-system switch 41 and cut off the battery switch 42.

[0053] Specifically, when a ground fault is detected by the primary ground fault detection unit 31, the secondary ground fault detection unit 32 samples the voltages of the first system 110 and the second system 120 at a predetermined period for a predetermined period of time. Then, the secondary ground fault detection unit 32 identifies the system that has sampled a voltage below the ground fault determination threshold continuously for a predetermined time (for example, 100 ms) or more as the system in which the ground fault is detected.

[0054] Further, when the secondary ground fault detection unit 32 samples a voltage exceeding the ground fault determination threshold continuously for a predetermined time (for example, 40 ms) or more, it determines that the ground fault is not continuous and stops outputting the second ground fault detection signal to the OR logic circuit 35. That is, it outputs a connection signal. When the OR logic circuit 35 receives the connection signal from the secondary ground fault detection unit 32, it outputs the connection signal to the inter-system switch 41 to reconnect the inter-system switch 41. At this time, the secondary ground fault detection unit 32 outputs a control signal to the battery switch 42 via the OR logic circuit 34 to cut off the battery switch 42.

[0055] When the frequency at which the restoration control and the ground fault detection by the primary ground fault detection unit 31 are repeated after the ground fault is detected by the primary ground fault detection unit 31 is equal to or higher than a predetermined frequency, the fault determination unit 33 determines that the inter-system switch 41 is stuck open.

[0056] Specifically, the fault determination unit 33 includes an open-stuck determination timer 36 and a cut-off count counter 37. The open-stuck determination timer 36 resets the measurement time every time a predetermined time elapses. For example, the open-stuck determination timer 36 resets the measurement time every time 5 seconds elapse.

[0057] Every time a signal indicating that a ground fault has occurred in the first system 110 or the second system 120 is input from the primary ground fault detection unit 31 via the secondary ground fault detection unit 32, the cut-off count counter 37 increments the count value indicating the cut-off count of the inter-system switch 41 by 1. The cut-off count counter 37 resets the count value every time the measurement time of the open-stuck determination timer 36 becomes equal to or longer than a predetermined time.

[0058] Before the measurement time of the open-stuck determination timer 36 reaches a predetermined time, when the count value of the cut-off count counter 37 becomes equal to or more than a predetermined number of times (for example, 3 times), the fault determination unit 33 determines that the states shown in FIG. 7 and the state shown in FIG. 8 are repeated at a predetermined frequency or more, and determines that the inter-system switch 41 is stuck open. Thus, according to the power control device 1, the fault determination unit 33 can determine the open-stuck of the inter-system switch 41.

[0059] Further, when the failure determination unit 33 determines that the inter-system switch 41 is open-stuck, it outputs an automatic operation prohibition signal to the automatic operation control device 100 to prohibit automatic operation. Thereby, the power supply control device 1 can prevent the automatic operation from shifting to a dangerous state in which the inter-system switch 41 is open-stuck and the backup of the first power supply 10 by the second power supply 20 is impossible.

[0060] Also, after the failure determination unit 33 determines that the inter-system switch 41 is open-stuck, even if a ground fault is detected by the primary ground fault detection unit 31, the conduction of the battery switch 42 by the primary ground fault detection unit 31 is prohibited.

[0061] Specifically, after the failure determination unit 33 determines that the inter-system switch 41 is open-stuck, when a signal indicating that a ground fault has occurred in the first system 110 or the second system 120 is input from the primary ground fault detection unit 31 via the secondary ground fault detection unit 32, a control signal for prohibiting the conduction of the battery switch 42 thereafter is output to the battery switch 42.

[0062] Thereby, the power supply control device 1 can suppress the deterioration of the LiB 21 due to repeated discharges by preventing the second power supply 20 from discharging unnecessarily after the inter-system switch 41 is open-stuck.

[0063] [6. Processing Executed by Switch Driving Unit] Next, the processing executed by the switch driving unit 3 of the power supply control device 1 will be described with reference to FIG. 10. FIG. 10 is a flowchart showing an example of the processing executed by the switch driving unit 3 of the power supply control device 1 according to the embodiment. The switch driving unit 3 repeatedly executes the processing shown in FIG. 10 during normal operation.

[0064] Specifically, as shown in FIG. 10, the switch drive unit 3 first determines whether the open fixation determination time of the inter-system switch 41 is equal to or longer than a predetermined time (step S101). If the switch drive unit 3 determines that the open fixation determination time is not equal to or longer than the predetermined time (step S101, No), the process proceeds to step S103.

[0065] If the switch drive unit 3 determines that the open fixation determination time is equal to or longer than the predetermined time (step S101, Yes), it resets the open fixation determination timer 36 and the interruption count counter 37 (step S102), and determines whether a power supply abnormality has occurred (step S103). If the switch drive unit 3 determines that a power supply abnormality has not occurred (step S103, No), the process proceeds to step S101.

[0066] If the switch drive unit 3 determines that a power supply abnormality has occurred (step S103, Yes), it interrupts the inter-system switch 41 and conducts the battery switch 42 (step S104). Subsequently, the switch drive unit 3 increments the count value of the interruption count counter 37 by 1 (step S105).

[0067] Then, the switch drive unit 3 determines whether the number of interruptions of the inter-system switch 41 is equal to or more than a predetermined number (step S106). If the switch drive unit 3 determines that the number of interruptions is equal to or more than the predetermined number (step S106, Yes), it interrupts the inter-system switch 41 and interrupts the battery switch 42 (step S107), prohibits automatic driving, prohibits the conduction of the battery switch 42 (step S108), and ends the process.

[0068] Also, when the switch driving unit 3 determines that the number of interruptions is not equal to or greater than a predetermined number (step S106, No), it determines whether or not a power supply abnormality has been confirmed (step S109). When the switch driving unit 3 determines that a power supply abnormality has not been confirmed (step S109, No), it closes the inter-system switch 41 and closes the battery switch 42 (step S110), and transfers the process to step S101. Also, when the switch driving unit 3 determines that a power supply abnormality has been confirmed (step S109, Yes), it performs fail-safe control (step S111) and ends the process.

[0069] Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments presented and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Signs

[0070] 1 Power supply control device 10 First power supply 11 DC / DC 12 PbB 20 Second power supply 21 LiB 3 Switch driving unit 31 Primary ground fault detection unit 32 Secondary ground fault detection unit 33 Fault determination unit 34 OR logic circuit 35 OR logic circuit 36 Open stuck determination timer 37 Interruption count counter 41 Inter-system switch 42 Battery switch 51 First voltage sensor 52 Second voltage sensor 100 Automatic driving control device 101 First load 102 General load 103 Second load 110 First system 120 Second system

Claims

1. A first system that supplies the power of a first power source to a first load, A second system that supplies the power of a second power source to a second load, An inter-system switch capable of connecting and disconnecting the first system and the second system, A battery switch capable of connecting and disconnecting the second power source and the second system, A primary ground fault detection unit that shuts off the inter-system switch and conducts the battery switch when a ground fault in the first system or the second system is detected, When a ground fault is detected by the primary ground fault detection unit, it identifies whether the system in which the ground fault is detected is the first system or the second system, and if the ground fault has been eliminated, it performs a return control to reconnect the inter-system switch and shut off the battery switch. A secondary ground fault detection unit, A failure determination unit that determines that the inter-system switch is open-stuck when the frequency at which the return control and the ground fault detection by the primary ground fault detection unit are repeated after the ground fault is detected by the primary ground fault detection unit is equal to or higher than a predetermined frequency A power supply control device characterized by comprising the above.

2. The failure determination unit, When it determines that the inter-system switch is open-stuck, prohibits automatic operation by an automatic operation control device The power supply control device according to claim 1, characterized by the above.

3. The failure determination unit, After determining that the inter-system switch is open-stuck, prohibits conduction of the battery switch by the primary ground fault detection unit even if a ground fault is detected by the primary ground fault detection unit The power supply control device according to claim 1 or claim 2, characterized by the above.

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