Power supply device and disconnection detection method

Abstract

To provide a power supply device and a disconnection detection method that can reliably perform backup control by a second power supply when a power failure occurs in a first system.SOLUTION: A power supply device includes a first system, a second system, an inter-system switch, a current supply portion, and a disconnection detection portion. The first system supplies the power of a first power supply to a load. The second system supplies the power of a second power supply to the load. The inter-system switch is capable of connecting and disconnecting the connection path that connects the first system and the second system. The current supply portion constantly feeds a current through a specific path between a connection point between the connection path and the second system and the second power supply. The disconnection detection portion detects disconnection of the specific path according to the presence or absence of a current flowing through the specific path.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The disclosed embodiments relate to a power supply device and a method for detecting an open circuit. [Background technology]

[0002] Conventionally, there has been a redundant power supply system that includes a first power supply and a second power supply so that, even if a power failure occurs while a vehicle is traveling in autonomous driving mode, the vehicle can be evacuated to a safe place and stopped. In the event of a ground fault in one of the power supply systems, the other power supply system supplies power to on-board equipment (load) for autonomous driving (see, for example, Patent Document 1).

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

[0004] The redundant power supply system normally connects the inter-system switch to supply 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 shuts off the inter-system switch and supplies power from the second power supply to the second load, thereby performing backup control for evacuation driving. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-61240 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a redundant power supply system, if there is a disconnection between the connection path connecting the first and second systems and the connection point of the second system and the second power supply, backup control by the second power supply cannot be performed in the event of a power failure in the first system.

[0007] One aspect of the embodiment has been made in consideration of the above, and aims to provide a power supply device and a disconnection detection method that can reliably perform backup control using a second power source in the event of a power failure in the first system. [Means for solving the problem]

[0008] A power supply device according to one aspect of the embodiment includes a first system, a second system, an inter-system switch, a current supply unit, and a disconnection detection unit. The first system supplies power from a first power source to a load. The second system supplies power from a second power source to the load. The inter-system switch is capable of connecting and disconnecting a connection path connecting the first system and the second system. The current supply unit constantly passes a current through a specific path between the second power source and a connection point between the connection path and the second system. The disconnection detection unit detects a disconnection of the specific path depending on the presence or absence of a current flowing through the specific path. Effect of the Invention

[0009] A power supply device and a disconnection detection method according to an aspect of the embodiment provide an advantage in that, when a power failure occurs in a first system, backup control by a second power supply can be reliably performed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram showing an example of the configuration of a power supply device according to a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing an example of the operation of the power supply device according to the first embodiment. [Diagram 3] FIG. 3 is an explanatory diagram showing an example of the operation of the power supply device according to the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing an example of the operation of the power supply device according to the first embodiment. [Diagram 5] FIG. 5 is an explanatory diagram showing an example of the operation of the power supply device according to the first embodiment. [Figure 6]FIG. 6 is a flowchart showing an example of processing executed by the disconnection determination unit of the power supply device according to the first embodiment. [Figure 7] FIG. 7 is an explanatory diagram showing an example of the configuration of a power supply device according to the second embodiment. [Figure 8] FIG. 8 is an explanatory diagram showing an example of the operation of the power supply device according to the second embodiment. [Figure 9] FIG. 9 is a flowchart showing an example of processing executed by a disconnection determination unit of the power supply device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a power supply device and a disconnection detection method will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiment. Below, a power supply device that is mounted on a vehicle with an automatic driving function and supplies 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 that does not have an automatic driving function.

[0012] Further, although the following description will be given of a case where the vehicle on which the power supply device is mounted is an electric vehicle or a hybrid vehicle, the vehicle on which the power supply device is mounted may also be an engine vehicle that is run by an internal combustion engine.

[0013] [1. First embodiment] [1-1. Power supply configuration] Fig. 1 is an explanatory diagram showing a configuration example of a power supply device according to a first embodiment. As shown in Fig. 1, the power supply device 1 according to the first 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 supply device 1 includes a first system 110 that supplies power from the first power source 10 to the first load 101 and the general load 102, and a second system 120 that supplies power from a second power source 20 (described later) to the second load 103.

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

[0015] The second load 103 has the same function as the first load 101. The second load 103 includes 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 with 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 control the automatic driving of the vehicle.

[0016] The first power source 10 includes a DC / DC converter (hereinafter, referred to as "DC / DC 11") and a lead battery (hereinafter, referred to as "PbB 12"). The battery of the first power source 10 may be any secondary battery other than PbB 12.

[0017] The DC / DC 11 is connected to a generator and a high-voltage battery having a higher voltage than PbB 12, and steps down the voltages of the generator and the high-voltage battery and outputs the stepped-down voltage to the first system 110. The DC / DC 11 can also make the voltage of the first system 110 higher than the voltage of a second power source 20, which will be described later, by adjusting the amount of voltage step-down.

[0018] The generator is, for example, an alternator that converts the kinetic energy of a running vehicle into electricity to generate power, and the high-voltage battery is, for example, a battery mounted on an electric vehicle or a hybrid vehicle for driving the vehicle.

[0019] When the first power source 10 is installed in an engine vehicle, an alternator (generator) is provided instead of the DC / DC 11. The DC / DC 11 charges the PbB 12, supplies power to the first load 101 and the general load 102, supplies power to the second load 103, and charges the second power source 20 described later.

[0020] The power supply device 1 includes a second power supply 20, an inter-system switch 41, a battery switch 42, a disconnection determination unit 3, a current supply unit 61, voltage sensors 51 and 52, and a current sensor 53.

[0021] The second power source 20 is a backup power source in case the first power source 10 is unable to supply power. The second power source 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). Note that the battery of the second power source 20 may be any secondary battery other than the LiB21.

[0022] The inter-system switch 41 is a switch capable of connecting and disconnecting a connection path 130 that connects the first system 110 and the second system 120. The battery switch 42 is a switch capable of connecting and disconnecting the LiB 21 and the second system 120.

[0023] The current supply unit 61 is a circuit that constantly supplies a current to the specific path 121 if there is no disconnection in the specific path 121 between the second power source 20 and a connection point P between the connection path 130 and the second system 120. Specifically, the current supply unit 61 is a discharge path that branches off from the specific path 121 and has a current limiting element 62. Note that "constantly" in this embodiment is not limited to the concept of "continuously" but also includes the concept of "periodically."

[0024] The current limiting element 62 is, for example, a resistor having an extremely large resistance value, one end of which is connected to the specific path 121 and the other end of which is connected to ground, and which discharges a small amount of current from the specific path 121 to ground. Note that the current limiting element 62 is not limited to a resistor, and may be any other circuit element, such as a plurality of diodes connected in series, as long as it is a circuit element capable of reducing the current that flows.

[0025] 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 disconnection determination unit 3. The voltage sensor 52 is connected between the specific path 121 and the second load 103. The voltage sensor 52 detects the voltage of the second system 120 and outputs the detection result to the disconnection determination unit 3.

[0026] The disconnection 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 other circuits. The disconnection determination unit 3 may be configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0027] The disconnection determination unit 3 controls the operation of the power supply device 1 by causing the CPU to execute a program stored in the ROM using the RAM as a working area. The disconnection determination unit 3 controls the inter-system switch 41 and the battery switch 42 based on the detection results input from the voltage sensors 51 and 52.

[0028] The disconnection determination unit 3 controls the system switch 41 and the battery switch 42 to supply 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. In addition, the disconnection determination unit 3 detects a disconnection of the specific path 121 according to the presence or absence of a current flowing through the specific path 121, based on the detection result input from the current sensor 53.

[0029] When determining whether or not a break is occurring, the break determination unit 3 determines that the specific path 121 is not broken if there is a current flowing through the specific path 121, and determines that the specific path 121 is broken if there is no current flowing through the specific path 121.

[0030] As described above, the current supply unit 61 constantly supplies current to the specific path 121 unless there is a break in the specific path 121, so that the break determination unit 3 can immediately detect the occurrence of a break in the specific path 121.

[0031] When a disconnection occurs in the specific route 121, the disconnection determination unit 3 notifies the automatic driving control device 100 of that fact. When a disconnection occurs in the specific route 121, the disconnection determination unit 3 may notify the automatic driving control device 100 of a state in which automatic driving is impossible. When no disconnection occurs in the specific route 121, the disconnection determination unit 3 may notify the automatic driving control device 100 of a state in which automatic driving is possible.

[0032] In this way, the disconnection determination unit 3 grasps in real time the presence or absence of a disconnection in the specific path 121, and therefore can reliably perform backup control by the second power source 20 when a power failure occurs in the first system 110. An example of the operation of the power supply device 1 will be described later with reference to Figs. 2 to 5.

[0033] Furthermore, the disconnection determination unit 3 controls the system switch 41 and the battery switch 42 based on the detection result input from the voltage sensor 52 to charge the LiB 21 with the power supplied from the first power source 10.

[0034] The disconnection determination unit 3 turns off the inter-system switch 41 and turns on the battery switch 42 at predetermined times, for example, when the vehicle is started, shut down, or during manual driving, and obtains the detection result of the voltage of the LiB 21 from the voltage sensor 52.

[0035] If the voltage of the LiB 21 is equal to or lower than the charging threshold, the disconnection determination unit 3 turns on the inter-system switch 41 to charge the LiB 21 with power supplied from the first power source 10, and cuts off the battery switch 42 when charging is complete.

[0036] Furthermore, when a power failure such as a ground fault occurs in one of the first system 110 and the second system 120, the disconnection determination unit 3 supplies power to the load through the other system. As a result, even if a ground fault occurs in one of the systems during autonomous driving, the power supply device 1 can use the other system and have the autonomous driving control device 100 evacuate the vehicle to a safe place and stop it.

[0037] Next, the operation of the power supply device 1 will be described with reference to Figures 2 to 5. In Figures 2 to 5, in order to facilitate understanding of the operation of the power supply device 1, the disconnection determination unit 3, the automatic driving control device 100, and the signal lines indicated by the dashed arrows in Figure 1 are omitted.

[0038] [1-2. Normal operation of the power supply] Under normal circumstances when no ground fault has occurred in the first system 110 and the second system 120, the disconnection judgment unit 3 turns on the inter-system switch 41 and turns off the battery switch 42, as shown in FIG. 2, to supply power from the first power source 10 to the first load 101, the general load 102, and the second load 103.

[0039] [1-3. Operation of power supply unit when second system has ground fault] Next, the operation of the power supply device 1 when a ground fault occurs in the second system will be described with reference to Fig. 3. When a ground fault occurs in the first system 110 or the second system during normal operation shown in Fig. 2, a discharge occurs toward the ground fault point, and the detection results of the voltage sensors 51, 52 drop below the ground fault threshold.

[0040] Therefore, when at least one of the detection results input from the voltage sensors 51, 52 falls below the ground fault threshold, the disconnection judgment unit 3 judges that a ground fault has occurred in the first system 110 or the second system 120, and turns off the inter-system switch 41, as shown in Figure 3.

[0041] Then, after turning off the inter-system switch 41, the disconnection determination unit 3 turns on the battery switch 42 and determines whether the system has a ground fault based on the detection results of the voltage sensors 51, 52. If the detection result of the voltage sensor 51 exceeds the ground fault threshold and the detection result of the voltage sensor 52 is still equal to or lower than the ground fault threshold, the disconnection determination unit 3 determines that a ground fault 200 has occurred in the second system 120 and notifies the automatic driving control device 100 of that effect.

[0042] At this time, the disconnection determination unit 3 returns the battery switch 42 to the cut-off state. As a result, the autonomous driving control device 100 prevents further discharge of the LiB 21, while operating the first load 101 with the power supplied from the first power source 10 to the first load 101, and allows the vehicle to travel to an evacuation site.

[0043] [1-4. Operation of the power supply unit when the first system has a ground fault] Next, the operation of the power supply device 1 when a ground fault occurs in the first system will be described with reference to Fig. 4. As in the operation when a ground fault occurs in the second system 120, when the detection results input from the voltage sensors 51, 52 become equal to or lower than the ground fault threshold, the disconnection determination unit 3 determines that a ground fault has occurred in the first system 110 or the second system 120, and turns off the inter-system switch 41 as shown in Fig. 4.

[0044] Then, after turning off the inter-system switch 41, the disconnection determination unit 3 turns on the battery switch 42 and determines whether the system has a ground fault based on the detection results of the voltage sensors 51, 52. If the detection result of the voltage sensor 51 is still equal to or less than the ground fault threshold value and the detection result of the voltage sensor 52 exceeds the ground fault threshold value, the disconnection determination unit 3 determines that a ground fault 200 has occurred in the first system 110 and notifies the automatic driving control device 100 of that effect.

[0045] Then, the disconnection determination unit 3 maintains the conduction of the battery switch 42. As a result, the autonomous driving control device 100 operates the second load 103 with the power supplied from the second power source 20 to the second load 103, and allows the vehicle to travel to an evacuation site.

[0046] However, if a break occurs in the specific path 121 at this time, the power supply device 1 cannot perform backup control to supply power from the second power source 20 to the second load 103 even if the battery switch 42 is turned on. Therefore, the power supply device 1 constantly monitors whether or not there is a break in the specific path 121 during normal operation.

[0047] [1-5. Disconnection monitoring for specific routes] 5, during normal operation of the power supply device 1, the first power source 10 and the ground are constantly connected via the current supply unit 61. Therefore, the power supply device 1 can constantly pass a current from the first power source 10 to the ground via the specific path 121 and the current supply unit 61, unless the specific path 121 is disconnected during normal operation.

[0048] When a break occurs in the specific path 121, the power supply device 1 stops current flowing through the specific path 121. Therefore, if the current sensor 53 detects a current, the break determination unit 3 can determine that there is no break in the specific path 121, and can immediately determine that a break has occurred in the specific path 121 when the current sensor 53 no longer detects a current.

[0049] Furthermore, the current supply unit 61 can constantly pass a current through a discharge path having a simple configuration in which a current limiting element 62 such as a resistor element is connected between the specific path 121 and the ground, so long as there is no break in the specific path 121. Furthermore, the current limiting element 62 limits the current supplied from the specific path 121 and discharges it to the ground, so that waste of the current used to detect a break in the specific path 121 can be suppressed.

[0050] [1-6. Processing performed by the disconnection determination unit] Next, an example of the process executed by the disconnection determination unit according to the first embodiment will be described with reference to Fig. 6. Fig. 6 is a flow chart showing an example of the process executed by the disconnection determination unit according to the first embodiment. The disconnection determination unit 3 according to the first embodiment repeatedly executes the process shown in Fig. 6 during normal operation.

[0051] 6, the disconnection determination unit 3 first determines whether or not there is a current flowing through the specific path 121 (step S101). If the disconnection determination unit 3 determines that there is no current flowing through the specific path 121 (step S101, No), it determines that there is a disconnection in the specific path 121 (step S107), notifies the automatic driving control device 100 of that fact (step S105), and ends the process. After that, the disconnection determination unit 3 starts the process again from step S101.

[0052] If the disconnection determination unit 3 determines that a current flows through the specific path 121 (step S101, Yes), it determines whether or not a ground fault has occurred (step S102). If the disconnection determination unit 3 determines that a ground fault has not occurred (step S102, No), it ends the process. After that, the disconnection determination unit 3 starts the process again from step S101.

[0053] Furthermore, if the disconnection determination unit 3 determines that a ground fault has occurred (Yes in step S102), it turns off the inter-system switch 41 and turns on the battery switch 42 (step S103), and determines whether or not a ground fault has occurred in the first system 110 (step S104).

[0054] If the disconnection determination unit 3 determines that the first system 110 has a ground fault (step S104, Yes), it notifies the automatic driving control device 100 of that fact (step S105) and ends the process. As a result, evacuation travel is performed in the second system 120. After that, the disconnection determination unit 3 starts the process again from step S101.

[0055] Furthermore, when the disconnection determination unit 3 determines that the ground fault is not in the first system 110 (step S104, No), the ground fault is in the second system 120, so the disconnection determination unit 3 turns off the battery switch 42 (step S106), notifies the automatic driving control device 100 that a ground fault has occurred in the second system 120 (step S105), and ends the process. As a result, evacuation travel is performed in the first system 110. After that, the disconnection determination unit 3 starts the process again from step S101.

[0056] In addition, when the disconnection judgment unit 3 detects a ground fault in the first system 110, a ground fault in the second system 120, or a disconnection in the specific path 121 and notifies the automatic driving control device 100 of this, it can end the processing without starting the processing again from step S101.

[0057] [2. First embodiment] [2-1. Power supply configuration and operation] Next, a configuration example and an operation example of a power supply device according to a second embodiment will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is an explanatory diagram showing a configuration example of a power supply device according to a second embodiment. Fig. 8 is an explanatory diagram showing the operation of a power supply device according to a second embodiment. Here, among the components shown in Fig. 7, the same components as those shown in Fig. 1 are given the same reference numerals as those shown in Fig. 1, and duplicated explanations will be omitted.

[0058] As shown in FIG. 7, the power supply device 1a according to the second embodiment does not include the current supply unit 61 shown in FIG. 1, but instead functions as a current supply unit 63 in which the DC / DC 11 of the first power supply 10 constantly supplies current to a specific path 121.

[0059] The DC / DC 11 functioning as the current supply unit 63 functions as a transformer unit 64 that controls the voltage of the first power source 10 to be always higher or lower than the voltage of the second power source 20. Furthermore, the power supply device 1a includes a voltage sensor 54 that detects the voltage of the second power source 20 and outputs the detection result to the disconnection determination unit 3a.

[0060] The disconnection determination unit 3a controls the inter-system switch 41 and the battery switch 42 in the same manner as in the first embodiment during normal operation, operation during the first system earth fault, and operation during the second system earth fault. Specifically, the disconnection determination unit 3a normally turns on the inter-system switch 41 and turns off the battery switch 42 to supply power from the first power source 10 to the first load 101, the general load 102, and the second load 103.

[0061] Furthermore, when a ground fault occurs in the first system 110, the disconnection determination unit 3a cuts off the inter-system switch 41 and turns on the battery switch 42 to supply power from the second power source 20 to the second load 103. Furthermore, when a ground fault occurs in the second system 120, the disconnection determination unit 3a cuts off the inter-system switch 41 and supplies power from the first power source 10 to the first load 101 with the battery switch 42 turned off.

[0062] However, the operation of the disconnection determination unit 3a when determining the presence or absence of a disconnection in the specific path 121 differs from that of the first embodiment. Specifically, at a predetermined timing for determining the presence or absence of a disconnection in the specific path 121, the disconnection determination unit 3a turns on the battery switch 42 while keeping the system switch 41 conductive, as shown in FIG.

[0063] As a result, for example, when the voltage of the first power source 10 is higher than the voltage of the second power source 20, if there is no break in the specific path 121, the current sensor 53 detects a current because a current flows from the connection point P to the second power source 20 as shown by the thick arrow in Fig. 8. At this time, if there is a break in the specific path 121, no current flows and the current sensor 53 does not detect a current.

[0064] Furthermore, when the voltage of the first power source 10 is lower than the voltage of the second power source 20, if there is no break in the specific path 121, a current flows from the second power source 20 to the connection point P as shown by the dashed arrow in Fig. 8, and thus the current sensor 53 detects a current. At this time, if there is a break in the specific path 121, no current flows, and therefore the current sensor 53 does not detect a current.

[0065] Therefore, when the battery switch 42 is made conductive while the system switch 41 is made conductive, if no current is detected by the current sensor 53, the disconnection determination unit 3a determines that there is a disconnection in the specific path 121.

[0066] Furthermore, when the battery switch 42 is made conductive while the system switch 41 is made conductive, if a current is detected by the current sensor 53, the disconnection determination unit 3a determines that there is no disconnection in the specific path 121.

[0067] However, in the power supply unit 1a, when the battery switch 42 is turned on while the system switch 41 is turned on, if the voltage of the first power source 10 and the voltage of the second power source 20 are equal, no current flows through the specific path 121 even if there is no break in the line.

[0068] Therefore, when the disconnection determination unit 3a turns on the battery switch 42, it controls the voltage of the first power source 10 to be always higher or lower than the voltage of the second power source 20 based on the detection results of the voltage sensors 51, 54. This allows the current supply unit 63 to constantly supply current to the specific path 121 if there is no disconnection in the specific path 121 when the disconnection determination for the specific path 121 is performed.

[0069] For example, the disconnection determination unit 3a operates the DC / DC 11 to control the voltage of the first power source 10 to be higher than the voltage of the second power source 20. At this time, the disconnection determination unit 3a operates the DC / DC 11 so that the amount of voltage reduction of the generator or high-voltage battery by the DC / DC 11 is smaller than that in normal times, thereby reducing the voltage of the first power source 10.

[0070] Furthermore, the disconnection determination unit 3a performs control such that the voltage of the first power supply 10 becomes lower than the voltage of the second power supply 20 by stopping the operation of the DC / DC 11. When the operation of the DC / DC 11 stops, the PbB 12 continues to supply power to the first load 101, the general load 102, and the second load 103 without being charged, so that the voltage of the PbB 12 becomes lower than the voltage of the second power supply 20.

[0071] When determining a disconnection of the specific path 121, the disconnection determination unit 3a may, in addition to stopping the DC / DC 11, for example, force the first load 101 and the general load 102 to operate by a higher-level ECU (Electronic Control Unit) to consume the power of the first power source 10. This allows the disconnection determination unit 3a to control the voltage of the first power source 10 to be lower than the voltage of the second power source 20 more quickly.

[0072] [2-2. Processing performed by the disconnection determination unit] Next, an example of the process executed by the disconnection determination unit according to the second embodiment will be described with reference to Fig. 9. Fig. 9 is a flow chart showing an example of the process executed by the disconnection determination unit according to the second embodiment. The disconnection determination unit 3a according to the second embodiment repeatedly executes the process shown in Fig. 9 during normal operation.

[0073] Specifically, as shown in Fig. 9, the disconnection determination unit 3a first determines whether or not it is time to detect a disconnection in the specific path 121. The disconnection detection timing may be constant or may be at a predetermined cycle. When the disconnection determination unit 3a determines that it is not time to detect a disconnection (step S201, No), the process proceeds to step S206.

[0074] Furthermore, when it is determined that it is time to detect a disconnection (Yes at step S201), the disconnection determination unit 3a controls the voltage of the first power source 10 to be higher or lower than the voltage of the second power source 20 (step S202). After that, the disconnection determination unit 3a turns on the battery switch 42 (step S203). Note that the order of the process of step S202 and the process of step S203 may be reversed.

[0075] Next, the disconnection determination unit 3a determines whether or not there is a current flowing through the specific path 121 (step S204). When the disconnection determination unit 3a determines that there is no current flowing through the specific path 121 (step S204, No), it determines that there is a disconnection in the specific path 121 (step S211), notifies the automatic driving control device 100 of that fact (step S209), and ends the process. After that, the disconnection determination unit 3a restarts the process from step S201.

[0076] If the disconnection determination unit 3a determines that a current flows through the specific path 121 (step S204, Yes), it turns off the battery switch 42 (step S205) and determines whether a ground fault has occurred (step S206). If the disconnection determination unit 3a determines that a ground fault has not occurred (step S206, No), it ends the process and restarts the process from step S201.

[0077] Furthermore, if the disconnection determination unit 3a determines that a ground fault has occurred (step S206, Yes), it turns off the inter-system switch 41 and turns on the battery switch 42 (step S207), and determines whether or not the first system 110 has a ground fault (step S208). If the disconnection determination unit 3a determines that the first system 110 has a ground fault (step S208, Yes), it notifies the automatic driving control device 100 of this (step S209) and ends the process. As a result, evacuation travel is performed in the second system 120. After that, the disconnection determination unit 3a restarts the process from step S201.

[0078] Furthermore, when the disconnection determination unit 3a determines that the fault is not a ground fault in the first system 110 (step S208, No), the fault is a ground fault in the second system 120, so the disconnection determination unit 3a turns off the battery switch 42 (step S210), notifies the automatic driving control device 100 of this (step S209), and ends the process. As a result, evacuation travel is performed in the first system 110. After that, the disconnection determination unit 3a restarts the process from step S201.

[0079] In addition, when the disconnection judgment unit 3a detects a ground fault in the first system 110, a ground fault in the second system 120, or a disconnection in the specific path 121 and notifies the automatic driving control device 100 of this, it can end the processing without starting the processing again from step S201.

[0080] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0081] 1,1a power supply 10 1st power supply 11 DC / DC 12 PbB 20 2nd power supply 21 LiB 3. Disconnection detection section 41 Intersystem switch 42 Battery switch 51, 52, 54 Voltage Sensor 53 Current Sensor 61,63 Current supply section 62 Current limiting element 64 Transformer 100 Automatic driving control device 101 1st load 102 General load 103 2nd load 110 1st system 120 2nd system 121 Specific Route 130 Connection Path P Connection Point

Claims

1. a first system that supplies power from a first power source to a load; a second system that supplies power from a second power source to a load; an inter-system switch capable of connecting and disconnecting a path connecting the first system and the second system; a current supply unit that constantly supplies a current to a specific path between a connection point between the connection path and the second system and the second power source; a disconnection detection unit that detects a disconnection of the specific path depending on the presence or absence of a current flowing through the specific path; A power supply device comprising:

2. The current supply unit includes: A discharge path that branches off from the specific path and has a current limiting element.

2. The power supply device according to claim 1 .

3. The current supply unit includes: A transformer unit that controls the voltage of the first power source so that it is always higher or lower than the voltage of the second power source.

2. The power supply device according to claim 1 .

4. a first system that supplies power from a first power source to a load; a second system that supplies power from a second power source to a load; an inter-system switch capable of connecting and disconnecting a connection path connecting the first system and the second system; A current supply unit of a power supply device comprising: causing a current to flow through a specific path between a connection point between the connection path and the second system and the second power source; The disconnection detection unit of the power supply device detecting a break in the specific path according to the presence or absence of a current flowing through the specific path; A method for detecting a disconnection, comprising:

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