Power supply device

Abstract

To provide a power supply device and a determination metho, capable of determining whether or not there is a ground fault of a second system while suppressing discharge of a second power supply.SOLUTION: A power supply device according to an embodiment comprises: a first system; a second system; an inter-system switch; a determination unit; and a suppression circuit. The first system supplies electric power of a first power supply to a first load. The second system supplies electric power of a second power supply to a second load. The inter-system switch is capable of connecting and disconnecting the first system and the second system. The determination unit turns on the inter-system switch during normal time, and upon detecting a ground fault of the first system or the second system, determines which of the systems has the ground fault by turning off the inter-system switch. The suppression circuit suppresses discharge of the second power supply and supplies power for determining a ground fault to the second system. The determination unit determines whether or not any ground fault has occurred in the second system on the basis of the power supplied to the second system from the suppression circuit.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, even if a power failure occurs during driving by automatic driving of a vehicle, a redundant power supply system having a first power supply and a second power supply is provided so that the vehicle can be driven to a safe place and stopped. When a ground fault occurs in one power supply system, the other power supply system supplies power to in-vehicle devices (loads) for automatic driving.

[0003] The redundant power supply system includes a first system connected to a first load for automatic driving, a second system connected to a second load having the same function as the first load, and an inter-system switch capable of disconnecting the connection between the first system and the second system.

[0004] Normally, the redundant power supply system connects the inter-system switch and supplies power from the first power supply to the first load and the second load. When a power failure such as a ground fault occurs in the first system, the redundant power supply system disconnects the inter-system switch and supplies power from the second power supply to the second load to perform backup control for evacuation driving.

[0005] In the redundant power supply system, when a ground fault occurs in the second system, backup control by the second power supply cannot be performed. Therefore, when a ground fault in the first system or the second system is detected, it is necessary to determine whether or not there is a ground fault in the second system.

[0006] For this reason, there is a power supply system that detects a ground fault in the first system or the second system, disconnects the inter-system switch, and then supplies power from the second power supply to the second system to determine whether or not there is a ground fault in the second system (see, for example, Patent Document 1). The power supply system determines that there is a ground fault in the second system if the voltage of the second system is lower than the normal voltage, and determines that there is no ground fault in the second system if the voltage is normal.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the conventional technology, in order to discharge the second power source to determine whether or not there is a ground fault in the second system, the remaining amount of power stored in the second power source decreases, and the time for enabling backup control for evacuation travel becomes short.

[0009] One aspect of the embodiment is made in view of the above, and an object is to provide a power supply device and a determination method capable of determining whether or not there is a ground fault in the second system while suppressing the discharge of the second power source.

Means for Solving the Problems

[0010] A power supply device according to one aspect of the embodiment includes a first system, a second system, an inter-system switch, a determination unit, and a suppression circuit. 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 determination unit turns on the inter-system switch during normal times, and turns off the inter-system switch and determines the grounded system when a ground fault in the first system or the second system is detected. The suppression circuit suppresses the discharge of the second power source and supplies power for ground fault determination to the second system. The determination unit determines whether or not a ground fault has occurred in the second system based on the power supplied to the second system from the suppression circuit.

Effects of the Invention

[0011] The power supply device and the determination method according to one aspect of the embodiment have an effect that it is possible to determine whether or not there is a ground fault in the second system while suppressing the discharge of the second power source.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the power supply device and the determination 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 supply device mounted on a vehicle equipped with an automatic driving function and supplying power to a load will be described as an example, but the power supply device according to the embodiment may be mounted on a vehicle not equipped with an automatic driving function.

[0014] Further, in the following, although the case where the vehicle equipped with the power supply device is an electric vehicle or a hybrid vehicle will be described, the vehicle equipped with the power supply device may be an engine vehicle that runs by an internal combustion engine.

[0015] [1. First Embodiment] [1-1. Configuration of Power Supply Device] FIG. 1 is an explanatory diagram showing a configuration example of a power supply device according to the first embodiment. As shown in FIG. 1, the power supply device 1 according to the first embodiment is connected to a first power supply 10, a first load 101, a general load 102, a second load 103, and an automatic driving control device 100. The power supply device 1 includes a first system 110 that supplies the power of the first power supply 10 to the first load 101 and the general load 102, and a second system 120 that supplies the power of a second power supply 20, which will be described later, to the second load 103.

[0016] The first load 101 includes loads for automatic driving. For example, the first load 101 includes a steering motor, an electric brake device, an in-vehicle camera, and a radar that operate during automatic driving. The general load 102 includes, for example, a display, an air conditioner, an audio, a video, and various lights.

[0017] The second load 103 has the same functions as the first load 101. The second load 103 includes, for example, devices that operate during automatic driving, such as a steering motor, an electric brake device, an in-vehicle camera, and a radar. The first load 101, the general load 102, and the second load 103 operate by the power supplied from the power supply device 1. The automatic driving control device 100 is a device that operates the first load 101 or the second load 103 to perform automatic driving control of the vehicle.

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

[0019] 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 for power generation. The high-voltage battery is, for example, a vehicle drive battery mounted on an electric vehicle or a hybrid vehicle.

[0020] In addition, 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.

[0021] The power supply device 1 includes a second power source 20, an inter-system switch 41, a battery switch 42, a determination unit 3, a suppression circuit 61, and voltage sensors 51 and 52.

[0022] 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.

[0023] The inter-system switch 41 is a switch capable of connecting and disconnecting the first system 110 and the second system 120. The battery switch 42 is a switch capable of connecting and disconnecting LiB 21 and the suppression circuit 61.

[0024] The suppression circuit 61 is a circuit that suppresses the discharge of the second power source 20 and supplies power for ground fault determination to the second system 120. The suppression circuit 61 is connected between the battery switch 42 and the second load 103. The suppression circuit 61 includes a backup switch 43 and a current limiting circuit 62.

[0025] The backup switch 43 is a switch capable of connecting and disconnecting the battery switch 42 and the second load 103. The current limiting circuit 62 is a circuit that limits the current output from the second power source 20 and supplies power to the second system 120. The current limiting circuit 62 is connected in parallel with the backup switch 43. The current limiting circuit 62 is, for example, a resistor 63.

[0026] Note that the current limiting circuit 62 is not limited to the resistor 63. As long as the current limiting circuit 62 can limit the current output from the second power source 20, it may be other circuit elements. For example, the current limiting circuit 62 may be a plurality of diodes connected in series.

[0027] The voltage sensor 51 is connected between the first power source 10 and the first load 101. The voltage sensor 51 detects the voltage of the first system 110 and outputs the detection result to the determination unit 3. The voltage sensor 52 is connected between the suppression circuit 61 and the second load 103. The voltage sensor 52 detects the voltage of the second system 120 and outputs the detection result to the determination unit 3.

[0028] The determination 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 determination unit 3 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0029] The determination unit 3 controls the operation of the power supply device 1 by the CPU executing the program stored in the ROM using the RAM as a work area. The determination unit 3 determines the ground fault of the first system 110 or the second system 120 based on the detection results input from the voltage sensors 51 and 52, and controls the on / off of the inter-system switch 41, the battery switch 42, and the backup switch 43.

[0030] The determination unit 3 supplies power from the first power source 10 or the second power source 20 to the first load 101, the general load 102, and the second load 103 by controlling the on / off states of the inter-system switch 41, the battery switch 42, and the backup switch 43. The power supply operation of the power supply device 1 will be described later with reference to FIGS. 2 to 5.

[0031] Also, when the voltage of the LiB 21 drops, the determination unit 3 charges the LiB 21 with the power supplied from the first power source 10. For example, when the voltage of the LiB 21 detected by a voltage sensor (not shown) becomes equal to or lower than the charging threshold value, the determination unit 3 turns on the inter-system switch 41, the battery switch 42, and the backup switch 43. As a result, the LiB 21 is charged with the power supplied from the first power source 10.

[0032] When a power supply fault such as a ground fault occurs in one of the first system 110 and the second system 120, the determination unit 3 supplies power to the load by the other system. Thereby, even if either one of the systems has a ground fault during automatic operation, the power supply device 1 can use the other system and cause the vehicle to retreat to a safe place and stop by the automatic driving control device 100.

[0033] Next, with reference to FIGS. 2 to 5, the operation of the power supply device 1 will be described. In FIGS. 2 to 5, for ease of understanding the operation of the power supply device 1, the illustration of the determination unit 3, the automatic driving control device 100, and the control signal lines shown by broken line arrows in FIG. 1 is omitted.

[0034] [1-2. Normal operation of the power supply device] During normal times when no ground fault has occurred in the first system 110 and the second system 120, as shown in FIG. 2, the determination unit 3 turns on the inter-system switch 41, turns off the battery switch 42, and turns off the backup switch 43, and supplies power from the first power source 10 to the first load 101, the general load 102, and the second load 103.

[0035] [1-3. Ground fault system determination operation of the power supply device] In the power supply device 1, when a ground fault 200 occurs in the first system 110 or the second system 120 during normal operation shown in FIG. 2, discharge from the first power supply 10 and the second power supply 20 to the ground fault point occurs. Therefore, as shown in FIG. 3, when the determination unit 3 detects the ground fault 200 in the first system 110 or the second system 120, in order to suppress the discharge from the power supply where the ground fault 200 has not occurred to the ground fault point, the inter-system switch 41 is turned off.

[0036] Specifically, when at least one of the voltages detected by the voltage sensors 51 and 52 becomes equal to or lower than the ground fault threshold due to the occurrence of the ground fault 200, the determination unit 3 determines that the ground fault 200 has occurred in the first system 110 or the second system 120, and turns off the inter-system switch 41.

[0037] Note that the power supply device 1 may be configured to include current sensors instead of the voltage sensors 51 and 52. In this case, when the current detected by the current sensor becomes equal to or higher than the ground fault threshold, the determination unit 3 determines that the ground fault 200 has occurred in the first system 110 or the second system 120, and turns off the inter-system switch 41.

[0038] After that, the determination unit 3 determines in which system, the first system 110 or the second system 120, the ground fault 200 has occurred. At this time, if the ground fault 200 has not occurred in the first system 110 and has occurred in the second system 120, after the inter-system switch 41 is turned off, power is supplied from the first power supply 10 to the first load 101, but power is not supplied from the second power supply 20 to the second load 103.

[0039] Therefore, after the determination unit 3 turns off the inter-system switch 41, if the voltage detected by the voltage sensor 51 returns to a voltage higher than the ground fault threshold within a predetermined time T for abnormal determination confirmation, the determination unit 3 determines that there is no ground fault 200 in the first system 110. Also, if the voltage detected by the voltage sensor 51 is continuously equal to or lower than the ground fault threshold for the predetermined time T, the determination unit 3 determines that there is a ground fault 200 in the first system 110 and confirms that an abnormality has occurred in the first system 110.

[0040] Similarly, after turning off the inter-system switch 41, the determination unit 3 directly connects the second power supply 20 and the second load 103, for example. If the voltage detected by the voltage sensor 52 returns to a voltage higher than the ground fault threshold within a predetermined time T, it can be determined that there is no ground fault 200 in the second system 120. Further, if the voltage detected by the voltage sensor 52 is continuously below the ground fault threshold for a predetermined time T, it can be determined that there is a ground fault 200 in the second system 120.

[0041] However, when directly connecting the second power supply 20 and the second load 103 and discharging the second power supply 20 to determine whether there is a ground fault 200 in the second system 120, a part of the power stored in the second power supply 20 is consumed for the determination, the remaining amount of power of the second power supply 20 decreases, and the time for enabling backup control for evacuation running becomes shorter.

[0042] Therefore, the power supply device 1 includes a suppression circuit 61 that suppresses the discharge of the second power supply 20 and supplies power for ground fault determination to the second system 120. Then, the determination unit 3 determines whether a ground fault 200 has occurred in the second system 120 based on the power supplied from the suppression circuit 61 to the second system 120. Thereby, the power supply device 1 can determine whether there is a ground fault 200 in the second system 120 while suppressing the discharge of the second power supply 20.

[0043] Specifically, as shown in FIG. 3, when the determination unit 3 detects a ground fault 200 in the first system 110 or the second system 120, it turns off the inter-system switch 41 and turns on the battery switch 42. At this time, the backup switch 43 is off.

[0044] Then, the determination unit 3 determines whether a ground fault 200 has occurred in the second system 120 based on the power supplied from the current limiting circuit 62 to the second system 120. At this time, if there is no ground fault 200 in the second system 120, the power with the current output from the second power supply 20 limited is supplied from the second power supply 20 to the second load 103 via the battery switch 42 and the resistor 63.

[0045] As a result, the voltage detected by the voltage sensor 52 becomes higher than the ground fault threshold value. On the other hand, if there is a ground fault 200 in the second system 120, even if the battery switch 42 is turned on, current flows from the second power supply 20 to the ground fault point, so the voltage detected by the voltage sensor 52 becomes equal to or lower than the ground fault threshold value.

[0046] Therefore, after the determination unit 3 turns off the inter-system switch 41 and turns on the battery switch 42, if the voltage detected by the voltage sensor 52 is continuously lower than the ground fault threshold value for a predetermined time T, it is determined that there is a ground fault in the second system 120, and it is confirmed that an abnormality has occurred in the second system 120. If the voltage detected by the voltage sensor 52 returns to be equal to or higher than the ground fault threshold value within the predetermined time T, it is determined that there is no ground fault in the second system 120.

[0047] When the determination unit 3 determines that there is no ground fault in either the first system 110 or the second system 120, it is determined that it is a temporary overload due to the first load 101, the second load 103, etc., or a false detection due to noise, etc. Then, the inter-system switch 41 is turned on, and then the battery switch 42 is turned off to return to the normal state.

[0048] In this way, the power supply device 1 supplies the power for ground fault determination, in which the current output from the second power supply 20 is limited by the current limiting circuit 62, to the second system 120, and determines the presence or absence of the ground fault 200 in the second system 120. Thereby, the power supply device 1 can determine whether or not there is a ground fault 200 in the second system 120 while suppressing the discharge amount of the second power supply 20 to the minimum necessary.

[0049] [1-4. Operation of the Power Supply Device When the First System Has a Ground Fault] Next, with reference to FIG. 4, the operation of the power supply device 1 when the first system has a ground fault will be described. As shown in FIG. 4, when the determination unit 3 detects a ground fault 200 in the first system 110 and confirms an abnormality, the backup switch 43 is turned on from the state shown in FIG. 3.

[0050] As a result, the power supply device 1 can supply power from the second power supply 20 to the second load 103 via the battery switch 42 and the backup switch 43, and the vehicle can be driven in retreat by the second load 103.

[0051] In this way, when the power supply device 1 detects and determines the ground fault 200 in the first system 110, it directly supplies power from the second power supply 20 to the second load 103 without performing current limiting by the current limiting circuit 62, so that sufficient power can be supplied to the second load 103.

[0052] [1-5. Operation of the power supply device during a ground fault in the second system] Next, with reference to FIG. 5, the operation of the power supply device 1 during a ground fault in the second system will be described. As shown in FIG. 5, when the determination unit 3 detects a ground fault 200 in the second system 120 and determines an abnormality, it can supply power from the first power supply 10 to the first load 101, and the vehicle can be driven in retreat by the first load 101.

[0053] [1-6. Processing executed by the determination unit of the power supply device] Next, with reference to FIG. 6, an example of the processing executed by the determination unit of the power supply device according to the first embodiment will be described. FIG. 6 is a flowchart showing an example of the processing executed by the determination unit of the power supply device according to the first embodiment.

[0054] During normal operation when the vehicle is started, the determination unit 3 executes the processing shown in FIG. 6. As shown in FIG. 6, when the vehicle is started, the determination unit 3 first determines whether a ground fault in the first system 110 or the second system 120 has been detected (step S101).

[0055] If the determination unit 3 determines that a ground fault in the first system 110 or the second system 120 has not been detected (step S101, No), the determination process in step S101 is repeated until a ground fault is detected. Also, if the determination unit 3 determines that a ground fault in the first system 110 or the second system 120 has been detected (step S101, Yes), it turns off the inter-system switch 41 (step S102) and turns on the battery switch 42 (step S103).

[0056] Thereafter, the determination unit 3 determines whether or not a ground fault has occurred in the first system 110 (step S104). When the determination unit 3 determines that a ground fault has occurred in the first system 110 (step S104, Yes), it determines that an abnormality has occurred in the first system 110, turns on the backup switch 43 (step S105), supplies power from the second power supply 20 to the second load 103, and ends the process.

[0057] On the other hand, when the determination unit 3 determines that no ground fault has occurred in the first system 110 (step S104, No), it determines whether or not a ground fault has occurred in the second system 120 (step S106). When the determination unit 3 determines that a ground fault has occurred in the second system 120 (step S106, Yes), it determines that an abnormality has occurred in the second system 120, turns off the battery switch 42 (step S107), prevents the discharge of the second power supply 20, supplies power from the first power supply 10 to the first load 101, and ends the process.

[0058] On the other hand, when the determination unit 3 determines that no ground fault has occurred in the second system 120 (step S106, No), it determines that it is a false detection due to a temporary overload, noise, etc., and turns on the inter-system switch 41 (step S108) in order to return to the normal state. Then, the battery switch 42 is turned off (step S109). When returning to the normal state, the determination unit 3 can return to the normal state without interruption of the power supply to the second load 103 by turning off the battery switch 42 after turning on the inter-system switch 41.

[0059] [2. Second Embodiment] [2-1. Configuration of Power Supply Device] Next, with reference to FIG. 7, the configuration of the power supply device according to the second embodiment will be described. FIG. 7 is an explanatory diagram showing a configuration example of the power supply device according to the second embodiment. Hereinafter, among the components shown in FIG. 7, the same components as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG. 1, and redundant descriptions are omitted.

[0060] As shown in Fig. 7, the power supply device 1a according to the second embodiment is different from the power supply device 1 shown in Fig. 1 in that it includes a suppression circuit 61a instead of the suppression circuit 61 shown in Fig. 1, and the control of the battery switch 42 by the determination unit 3a is different.

[0061] The suppression circuit 61a includes a power storage circuit 62a. The power storage circuit 62a is charged by the power supplied from the first power supply 10, for example, and supplies the stored power to the second system 120. The power storage circuit 62a is, for example, a capacitor 63a.

[0062] When the determination unit 3 detects a ground fault in the first system 110 or the second system 120, it turns off the inter-system switch 41. At this time, the battery switch 42 remains off. For this reason, when the inter-system switch 41 is turned off, the capacitor 63a discharges and supplies power to the second system 120.

[0063] Thereby, the determination unit 3a can determine whether or not a ground fault has occurred in the second system 120 by using the power stored in the capacitor 63a without using the power of the second power supply 20.

[0064] Next, with reference to Figs. 8 to 11, the operation of the power supply device 1a will be described. In Figs. 8 to 11, for ease of understanding of the operation of the power supply device 1, the illustration of the determination unit 3, the automatic driving control device 100, and the control signal lines shown by broken line arrows in Fig. 7 is omitted.

[0065] [2-2. Normal operation of the power supply device] During normal times when no ground fault has occurred in the first system 110 and the second system 120, as shown in Fig. 8, the determination unit 3a turns on the inter-system switch 41 and turns off the battery switch 42, and supplies power from the first power supply 10 to the first load 101, the general load 102, and the second load 103. At this time, the capacitor 63a is charged by the power supplied from the first power supply 10.

[0066] [2-3. Ground fault system determination operation of the power supply device] As shown in FIG. 9, similar to the first embodiment, when at least one of the voltages detected by the voltage sensors 51 and 52 becomes equal to or lower than the ground fault threshold due to the occurrence of the ground fault 200, the determination unit 3a of the power supply device 1a determines that the ground fault 200 has occurred in the first system 110 or the second system 120, and turns off the inter-system switch 41. Thereafter, the determination unit 3a determines in which system, the first system 110 or the second system 120, the ground fault 200 has occurred.

[0067] After turning off the inter-system switch 41, if the voltage detected by the voltage sensor 51 returns to a voltage higher than the ground fault threshold within a predetermined time T, the determination unit 3a determines that there is no ground fault 200 in the first system 110. Also, if the voltage detected by the voltage sensor 51 is continuously equal to or lower than the ground fault threshold for a predetermined time T, the determination unit 3 determines that there is a ground fault 200 in the first system 110 and confirms that an abnormality has occurred in the first system 110.

[0068] Also, in the power supply device 1a, when the inter-system switch 41 is turned off, the capacitor 63a discharges and supplies power for ground fault determination to the second system 120. At this time, since the battery switch 42 is turned off, the second power supply 20 does not discharge.

[0069] Based on the power supplied from the capacitor 63a to the second system 120, if the voltage detected by the voltage sensor 52 returns to a voltage higher than the ground fault threshold within a predetermined time T, the determination unit 3a determines that there is no ground fault 200 in the second system 120. Also, if the voltage detected by the voltage sensor 52 is continuously equal to or lower than the ground fault threshold for a predetermined time T, the determination unit 3a determines that there is a ground fault 200 in the second system 120 and confirms that an abnormality has occurred in the second system 120.

[0070] In this way, when the power supply device 1a detects a ground fault in the first system 110 or the second system, it supplies the power for ground fault determination output from the capacitor 63a whose connection to the second power supply 20 has been cut off to the second system 120, and determines the presence or absence of the ground fault 200 in the second system 120. Thereby, the power supply device 1a can set the discharge amount of the second power supply 20 to 0 and determine whether or not there is a ground fault 200 in the second system 120.

[0071] [2-4. Operation of the power supply device during a ground fault in the first system] Next, with reference to FIG. 10, the operation of the power supply device 1a during a ground fault in the first system will be described. As shown in FIG. 10, when the determination unit 3a detects and determines a ground fault 200 in the first system 110, the battery switch 42 is turned on from the state shown in FIG. 9. Thereby, the power supply device 1a can supply power from the second power supply 20 to the second load 103, and the vehicle can be driven in retreat by the second load 103.

[0072] [2-5. Operation of the power supply device during a ground fault in the second system] Next, with reference to FIG. 11, the operation of the power supply device 1a during a ground fault in the second system will be described. As shown in FIG. 11, when the determination unit 3a detects and determines a ground fault 200 in the second system 120, the battery switch 42 remains off and power is supplied from the first power supply 10 to the first load 101, and the vehicle can be driven in retreat by the first load 101.

[0073] When the determination unit 3a determines that there is no ground fault in either the first system 110 or the second system 120, it determines that it was a temporary overload or false detection due to noise or the like by the first load 101, the second load 103, etc., and turns on the inter-system switch 41 to return to the normal state.

[0074] [2-6. Processing executed by the determination unit of the power supply device] Next, with reference to FIG. 12, an example of the processing executed by the determination unit of the power supply device according to the second embodiment will be described. FIG. 12 is a flowchart showing an example of the processing executed by the determination unit of the power supply device according to the second embodiment.

[0075] During normal operation when the vehicle is started, the determination unit 3a executes the process shown in FIG. 12. As shown in FIG. 12, when the vehicle is started, the determination unit 3a first determines whether a ground fault in the first system 110 or the second system 120 has been detected (step S201).

[0076] If the determination unit 3a determines that a ground fault in the first system 110 or the second system 120 has not been detected (step S201, No), the determination process of step S201 is repeated until a ground fault is detected. Also, if the determination unit 3a determines that a ground fault in the first system 110 or the second system 120 has been detected (step S201, Yes), the inter-system switch 41 is turned off (step S202), and it is determined whether a ground fault has occurred in the first system 110 (step S203).

[0077] If the determination unit 3a determines and confirms that a ground fault has occurred in the first system 110 (step S203, Yes), the battery switch 42 is turned on (step S204), and power is supplied from the second power source 20 to the second load 103 to end the process. Also, if the determination unit 3a determines that no ground fault has occurred in the first system 110 (step S203, No), it is determined whether a ground fault has occurred in the second system 120 (step S205).

[0078] If the determination unit 3a determines that a ground fault has occurred in the second system 120 (step S205, Yes), it is confirmed that an abnormality has occurred in the second system 120, and power is supplied from the first power source 10 to the first load 101 to end the process. At this time, since the battery switch 42 is off, the second power source 20 does not discharge.

[0079] Also, if the determination unit 3a determines that no ground fault has occurred in the second system 120 (step S205, No), it is determined that it is a false detection due to a temporary overload, noise, etc., and the inter-system switch 41 is turned on (step S206) to return to the normal state.

[0080] 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 described and represented as above. Accordingly, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Signs

[0081] 1, 1a Power supply device 10 First power supply 11 DC / DC 12 PbB 20 Second power supply 21 LiB 3, 3a Determination unit 41 Inter-system switch 42 Battery switch 43 Backup switch 51, 52 Voltage sensors 61, 61a Suppression circuit 62 Current limiting circuit 62a Power storage circuit 63 Resistor 63a Capacitor 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 supply to a first load, A second system that supplies the power of a second power supply 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 supply to the second system, A current limiting circuit that limits the current output from the second power supply and supplies power for ground fault determination to the second system, A determination unit that normally turns on the inter-system switch and turns off the inter-system switch when a ground fault in the first system or the second system is detected to determine the grounded system, When the determination unit detects a ground fault in the first system or the second system, it turns off the inter-system switch, turns on the battery switch, and determines whether a ground fault has occurred in the second system based on the power supplied from the current limiting circuit to the second system A power supply device characterized by the above.

2. It is provided with a backup switch in parallel with the current limiting circuit, The determination unit, When detecting a ground fault in the first system or the second system, it turns off the inter-system switch, turns on the battery switch, and turns off the backup switch, and determines whether a ground fault has occurred in the second system based on the power supplied from the current limiting circuit to the second system. When it determines that there is a ground fault in the first system, it turns off the inter-system switch, turns on the battery switch, and turns on the backup switch The power supply device according to claim 1, characterized by the above.

3. A first system that supplies the power of a first power supply to a first load, A second system that supplies the power of a second power supply 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 supply to the second system, A power storage circuit that supplies the stored power to the second system, A determination unit that normally turns on the inter-system switch and turns off the inter-system switch when a ground fault in the first system or the second system is detected to determine the grounded system, When the determination unit detects a ground fault in the first system or the second system, it turns off the inter-system switch and turns off the battery switch, and determines whether a ground fault has occurred in the second system based on the power supplied from the power storage circuit to the second system A power supply device characterized by the above. ​

4. When the determination unit determines that there is a ground fault in the first system, it turns off the inter-system switch and turns on the battery switch. The power supply device according to claim 3, characterized in that.

5. A first system that supplies the power of the first power supply to a first load that is at least one of a steering motor and an electric brake, A second system that supplies the power of the second power supply to a second load that is at least one of a steering motor and an electric brake, An inter-system switch that can connect and disconnect the first system and the second system, which are normally controlled to be on, A power supply device provided in a vehicle that performs evacuation travel in a state where the inter-system switch is controlled to be off when a ground fault in the first system or the second system is detected, A suppression circuit that suppresses the discharge of the second power supply and supplies power for ground fault determination to the second system, A determination unit that, when detecting a ground fault in the first system or the second system, turns off the inter-system switch and determines whether a ground fault has occurred in the second system based on the power supplied from the suppression circuit to the second system, Comprising The power supply device is characterized in that.

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