Power supply equipment and determination method

Abstract

A power supply device includes: a first system; a second system; an inter-system switch configured to be able to connect and disconnect between the first system and the second system; a determination unit configured to keep the inter-system switch in an on state during a normal time, and if a ground fault is detected in the first system or the second system, turn off the inter-system switch and determine the system in which the ground fault has occurred; and a suppression circuit configured to suppress discharge of a second power supply and supply power for ground fault detection to the second system, wherein the determination unit determines whether a ground fault has occurred in the second system based on the power supplied from the suppression circuit to the second system.

Description

Technical Field

[0001] Embodiments of the present invention relate to a power supply device and a determination method. Background Art

[0002] Conventionally, there is a redundant power supply system having a first power supply and a second power supply so that when a ground fault occurs in the other power supply system, power is supplied to the on-board equipment (load) by one of the power supply systems for self-driving, so that even if a power failure occurs while the vehicle is autonomously driving, the redundant power supply system can enable the vehicle to operate to evacuate to a safe place and stop there.

[0003] The redundant power supply system has a first system connected to a first load for self-driving, 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 between the first system and the second system.

[0004] The redundant power supply system typically maintains an intersystem switch in the on state to supply power from the first power source to the first load and the second load. Furthermore, if a power failure, such as a ground fault, occurs in the first system, the redundant power supply system performs backup control to turn off the intersystem switch, allowing power to be supplied from the second power source to the second load for evacuation.

[0005] To prevent the redundant power supply system from performing backup control using the second power supply when a ground fault occurs in the second system, if a ground fault in the first system or the second system is detected, the redundant power supply system needs to determine whether the detected ground fault is a ground fault in the second system.

[0006] To this end, there is a power supply system that detects a ground fault in the first or second system and determines whether the detected ground fault is a ground fault in the second system by turning off the intersystem switch and supplying power to the second system from the second power supply (see, for example, Japanese Patent Application Publication No. 2019-62727). When the voltage of the second system is lower than the normal voltage, the power supply system determines that it is a ground fault in the second system, and when the voltage of the second system is normal, the power supply system determines that it is not a ground fault in the second system. Summary of the Invention

[0007] However, in the conventional technology, since the second power source is discharged to determine whether the detected ground fault is a ground fault of the second system, the remaining power stored in the second power source is reduced and the time period when the backup control is operated for evacuation may be shortened.

[0008] One aspect of the embodiment has been made in view of such circumstances, and an object thereof is to provide a power supply apparatus and a determination method capable of determining whether a ground fault is a ground fault of a second system while suppressing discharge of a second power supply.

[0009] According to one aspect of the embodiment, a power supply device includes a first system, a second system, an intersystem switch, a determination unit, and a suppression circuit. The first system supplies power from a first power source to a first load. The second system supplies power from a second power source to a second load. The intersystem switch can connect and disconnect between the first and second systems. The determination unit maintains the intersystem switch in an on state during normal operation, and if a ground fault is detected in the first or second system, turns off the intersystem switch and determines the system in which the ground fault has occurred. The suppression circuit suppresses discharge of the second power source and supplies power to the second system for ground fault detection. The determination unit determines whether a ground fault has occurred in the second system based on the power supplied from the suppression circuit to the second system.

[0010] The power supply device and the determination method according to this aspect of the embodiment have the effect of being able to determine whether the ground fault is a ground fault of the second system while suppressing the discharge of the second power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is an explanatory view showing a configuration example of the power supply device according to the first embodiment.

[0012] Figure 2 : are explanatory views showing an operation example of the power supply device according to the first embodiment.

[0013] Figure 3 is an explanatory view showing another operation example of the power supply device according to the first embodiment.

[0014] Figure 4 1 is an explanatory view showing a further operation example of the power supply device according to the first embodiment.

[0015] Figure 5 : are explanatory views showing still further operation examples of the power supply device according to the first embodiment.

[0016] Figure 6 is a flowchart illustrating an example of processing performed by the determination unit of the power supply device according to the first embodiment.

[0017] Figure 7 is an explanatory view showing a configuration example of a power supply device according to the second embodiment.

[0018] Figure 8 : is an explanatory view showing an operation example of the power supply device according to the second embodiment.

[0019] Figure 9 is an explanatory view showing another operation example of the power supply device according to the second embodiment.

[0020] Figure 10 : are explanatory views showing a further operation example of the power supply device according to the second embodiment.

[0021] Figure 11 : are explanatory views showing still further operation examples of the power supply device according to the second embodiment.

[0022] Figure 12 is a flowchart illustrating an example of processing performed by a determination unit of the power supply device according to the second embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of a power supply device and a determination method will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. Hereinafter, the power supply device will be described as an example of a vehicle equipped with a self-driving function to supply power to a load. However, the power supply device according to the embodiments may also be installed in vehicles without self-driving functions.

[0024] Furthermore, hereinafter, description will be made of a case where a vehicle on which an electric device is mounted is a hybrid vehicle; however, a vehicle on which an electric device may be mounted may be an engine vehicle driven by an internal combustion engine.

[0025] [1. First embodiment]

[0026] [1-1. Configuration of power supply equipment]

[0027] Figure 1 1 is an explanatory diagram showing a configuration example of the power supply device according to the first embodiment. Figure 1 As shown, 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 a self-driving control device 100. The power supply device 1 includes a first system 110 and a second system 120. The first system 110 is used to provide power from the first power source 10 to the first load 101 and the general load 102, and the second system 120 is used to provide power from a second power source 20 (to be described below) to the second load 103.

[0028] The first load 101 includes loads used for self-driving. For example, the first load 101 includes a steering motor, electric brake system, onboard camera, radar, etc. that operate during self-driving. The general load 102 includes, for example, a display, air conditioning, audio system, video system, various lights, etc.

[0029] Second load 103 has the same function as first load. Second load 103 includes devices that operate during self-driving, such as a steering motor, electric brakes, onboard cameras, and radar. First load 101, general load 102, and second load 103 are operated by power supplied by power supply device 1. Self-driving control device 100 is a device that performs self-driving control of a vehicle by operating first load 101 or second load 103.

[0030] 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"). However, the battery used for the first power source 10 may be any secondary battery other than the PbB 12.

[0031] The DC / DC converter 11 is connected to a generator and a high-voltage battery having a higher voltage than the PbB 12, and reduces the voltage of the generator and the high-voltage battery, outputting them to the first system 110. The generator is, for example, an AC generator that generates electricity by converting the kinetic energy of a moving vehicle. The high-voltage battery is, for example, a vehicle drive battery that can be installed in an electric vehicle or a hybrid vehicle.

[0032] Incidentally, when the first power supply 10 is mounted on an engine vehicle, an AC generator (generator) may be provided instead of the DC / DC 11. The DC / DC 11 performs the functions of charging the PbB 12, supplying power to the first load 101 and the general load 102, supplying power to the second load 103, and charging the second power supply 20 (to be described below).

[0033] The power supply device 1 includes a second power supply 20 , an inter-system switch 41 , a battery switch 42 , a determination unit 3 , a suppression circuit 61 , and voltage sensors 51 and 52 .

[0034] The second power supply 20 is a backup power supply for situations where power supply by the first power supply 10 becomes impossible. The second power supply 20 includes a lithium-ion battery (hereinafter referred to as "LiB 21"). However, the battery used for the second power supply 20 may be any secondary battery other than LiB 21.

[0035] The inter-system switch 41 is a switch capable of connecting and disconnecting between the first system 110 and the second system 120. The battery switch 42 is a switch capable of connecting and disconnecting between the LiB 21 and the suppression circuit 61.

[0036] The suppression circuit 61 is a circuit for suppressing discharge of the second power source 20 and providing 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.

[0037] The backup switch 43 is a switch that can connect and disconnect between the battery switch 42 and the second load 103. The current limiting circuit 62 is a circuit for limiting the current output from the second power supply 20 and supplying 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.

[0038] However, the current limiting circuit 62 is not limited to the resistor 63. The current limiting circuit 62 may be any other circuit element as long as it can limit the current output from the second power source 20. For example, the current limiting circuit 62 may be a plurality of diodes connected in series.

[0039] The voltage sensor 51 is connected between the first power supply 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.

[0040] The determination unit 3 includes a microcomputer and various circuits having a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), etc. However, the determination unit 3 may be configured with hardware such as an application specific integrated circuit (ASIC) and a field programmable gate array (FPGA).

[0041] The CPU executes the program stored in the ROM using the RAM as a work area, so that the determination unit 3 controls the operation of the power supply device 1. The determination unit 3 determines a 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 states of the system room switch 41, the battery switch 42, and the backup switch 43.

[0042] The determination unit 3 controls the on / off states of the system room switch 41, the battery switch 42 and the backup switch 43 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. Figures 2 to 5 The power supply operation of the power supply device 1 is described.

[0043] Furthermore, if the voltage of the LiB 21 drops, the determination unit 3 charges the LiB 21 using the power supplied from the first power source 10. For example, when the voltage of the LiB 21 detected by the voltage sensor (not shown) becomes equal to or lower than the charging threshold, 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 using the power supplied from the first power source 10.

[0044] If a power failure 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 through the other system. Therefore, even if a ground fault occurs in either system during self-driving, the power supply device 1 uses the other system to enable the self-driving control device 100 to drive the vehicle to a safe place for evacuation and stop the vehicle.

[0045] Now, refer to Figures 2 to 5 The operation of the power supply device 1 is described. Figures 2 to 5 In order to facilitate understanding of the operation of the power supply device 1, the determination unit 3, the self-driving control device 100, Figure 1 The control signal lines indicated by dashed arrows are not shown.

[0046] [1-2. Normal operation of power supply equipment]

[0047] During a normal time when there is no ground fault in the first system 110 and the second system 120, the determination unit 3 Figure 2 As shown, the inter-system switch 41 is turned on, the battery switch 42 is turned off, and the backup switch 43 is turned off, so that power is supplied from the first power source 10 to the first load 101 , the general load 102 , and the second load 103 .

[0048] [1-3. Ground fault system determination operation of power supply equipment]

[0049] In power supply device 1, if Figure 2 If a ground fault 200 occurs in the first system 110 or the second system 120 during normal operation as shown, a discharge occurs from the first power source 10 and the second power source 20 to the ground fault point. Figure 3 As shown, if a ground fault is detected in the first system 110 or the second system 120 , the determination unit 3 turns off the inter-system switch 41 to prevent discharge from the power source where the ground fault 200 has not occurred to the ground fault point.

[0050] Specifically, if 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.

[0051] Incidentally, the power supply device 1 may have a configuration in which a current sensor is used instead of the voltage sensors 51 and 52. In this case, if the current detected by the current sensor becomes equal to or lower 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.

[0052] Subsequently, the determination unit 3 determines in which of the first system 110 and 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 the ground fault 200 has occurred in the second system 120, after the inter-system switch 41 is opened, power is supplied from the first power source 10 to the first load 101, but no power is supplied from the second power source 20 to the second load 103.

[0053] Therefore, after the inter-system switch 41 is opened, if the voltage detected by the voltage sensor 51 recovers to a voltage higher than the ground fault threshold within the predetermined time T for abnormality determination, the determination unit 3 determines that there is no ground fault 200 in the first system 110. Furthermore, if the voltage detected by the voltage sensor 51 continues to be 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 determines that an abnormality has occurred in the first system 110.

[0054] Similarly, after the inter-system switch 41 is disconnected, for example, when the second power source 20 is directly connected to the second load 103, if the voltage detected by the voltage sensor 52 recovers to a voltage higher than the ground fault threshold within a predetermined time T, the determination unit 3 can determine that there is no ground fault 200 in the second system 120. In addition, if the voltage detected by the voltage sensor 52 continues to be equal to or lower than the ground fault threshold within the predetermined time T, the determination unit 3 can determine that there is a ground fault 200 in the second system 120.

[0055] However, when the second power source 20 is directly connected to the second load 103 to discharge the second power source 20 in order to determine whether this is a ground fault 200 of the second system 120, a portion of the power stored in the second power source 20 is consumed to perform the determination, so that the remaining power stored in the second power source 20 is reduced, and the time period of backup control for evacuation can be shortened.

[0056] To this end, the power supply device 1 includes a suppression circuit 61 for suppressing discharge of the second power source 20 and supplying power for ground fault determination to the second system 120. Furthermore, 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. Therefore, the power supply device 1 can determine whether a ground fault 200 has occurred in the second system 120 while suppressing discharge of the second power source 20.

[0057] Specifically, if a ground fault 200 of the first system 110 or the second system 120 is detected, the determining unit 3 may determine whether the ground fault 200 is detected. Figure 3 As shown, the inter-system switch 41 is turned off and the battery switch 42 is turned on. At this time, the backup switch 43 is in the off state.

[0058] Furthermore, 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 output from the second power source 20 passes through the battery switch 42 and the resistor 63 so that the current is limited, and then the power from the second power source 20 is supplied to the second load 103.

[0059] As a result, the voltage detected by the voltage sensor 52 becomes higher than the ground fault threshold. In contrast, if a ground fault 200 occurs in the second system 120, even if the battery switch 42 is turned on, current flows from the second power source 20 to the ground fault point, so that the voltage detected by the voltage sensor 52 becomes equal to or lower than the ground fault threshold.

[0060] To this end, after the inter-system switch 41 is turned off and the battery switch 42 is turned on, if the voltage detected by the voltage sensor 52 continues to be lower than the ground fault threshold value for a predetermined time T, the determination unit 3 determines that a ground fault 200 exists in the second system 120 and determines that an abnormality has occurred in the second system 120. If the voltage detected by the voltage sensor 52 recovers to a voltage equal to or higher than the ground fault threshold value within the predetermined time T, the determination unit determines that there is no ground fault in the second system 120.

[0061] If it is determined that no ground fault has occurred in any of the first system 110 and the second system 120, the determination unit 3 determines that this is a detection error caused by a temporal overload, noise, etc. attributed to the first load 101, the second load 103, etc., and turns on the inter-system switch 41 and then turns off the battery switch 42, thereby restoring the power supply device to a normal state.

[0062] As described above, the power supply device 1 supplies the second system 120 with power for ground fault detection, which is obtained by limiting the current output from the second power source 20 by the current limiting circuit 62, thereby determining whether the ground fault 200 exists in the second system 120. Therefore, the power supply device 1 can determine whether the ground fault is the ground fault 200 of the second system 120 while suppressing the discharge amount of the second power source 20 to the necessary minimum.

[0063] [1-4. Operation of power supply equipment during the first system ground fault]

[0064] Now, refer to Figure 4 The operation of the power supply device 1 during a first system ground fault is described. Figure 4 As shown, if the ground fault 200 of the first system 110 is detected and determined to be abnormal, the determination unit 3 Figure 3The state shown is that the standby switch 43 is turned on.

[0065] As a result, the power supply device 1 supplies power from the second power source 20 to the second load 103 through the battery switch 42 and the backup switch 43 , so that the second load 103 can evacuate the vehicle.

[0066] As described above, if the ground fault 200 of the first system 110 is detected and determined, the power supply device 1 directly supplies power to the second load 103 from the second power supply 20 without performing current limiting by the current limiting circuit 62. Therefore, necessary and sufficient power can be supplied to the second load 103.

[0067] [1-5. Operation of power supply equipment during a second system ground fault]

[0068] Now, refer to Figure 5 The operation of the power supply device 1 during a second system ground fault is described. Figure 5 As shown, if a ground fault 200 of the second system 120 is detected and determined to be abnormal, the determination unit 3 supplies power from the first power source 10 to the first load 101 so that the first load 101 can evacuate the vehicle.

[0069] [1-6. Processing Performed by Determination Unit of Power Supply Device]

[0070] Now, refer to Figure 6 An example of processing performed by the determination unit of the power supply device according to the first embodiment is described. Figure 6 is a flowchart illustrating an example of processing performed by the determination unit of the power supply device according to the first embodiment.

[0071] During normal operation of the vehicle in an active state, the determination unit 3 performs Figure 6 As shown in the following example. Figure 6 As shown, if the vehicle is activated, the determination unit 3 first determines whether any ground fault of the first system 110 or the second system 120 has been detected (step S101 ).

[0072] If it is determined that no ground fault has been detected in the first system 110 or the second system 120 ("No" in step S101), the determination unit 3 repeats the determination process of step S101 until a ground fault is detected. Meanwhile, if it is determined that a ground fault has been detected in the first system 110 or the second system 120 ("Yes" in step S101), the determination unit 3 turns off the inter-system switch 41 (step S102) and turns on the battery switch 42 (step S103).

[0073] Subsequently, the determination unit 3 determines whether any ground fault has occurred in the first system 110 (step S104). If it is determined that a ground fault has occurred in the first system ("Yes" in step S104), the determination unit 3 determines that an abnormality has occurred in the first system 110, turns on the backup switch 43 (step S105) to supply power from the second power supply 20 to the second load 103, and ends the process.

[0074] Meanwhile, if it is determined that no ground fault has occurred in the first system 110 ("No" in step S104), the determination unit 3 determines whether any ground fault has occurred in the second system 120 (step S106). If it is determined that a ground fault has occurred in the second system 120 ("Yes" in step S106), the determination unit 3 determines that an abnormality has occurred in the second system 120, turns off the battery switch 42 (step S107) to prevent the second power source 20 from discharging, and supplies power from the first power source 10 to the first load 101, and ends the process.

[0075] Meanwhile, if it is determined that no ground fault has occurred in the second system 120 ("No" in step S106), the determination unit 3 determines that this is a detection error caused by time overload, noise, etc., and turns on the inter-system switch 41 (step S108), and then turns off the battery switch 42 (step S109), thereby restoring the power supply device to a normal state. In addition, since the determination unit 3 turns on the inter-system switch 41 and then turns off the battery switch 42 when the power supply device returns to a normal state, the power supply device can be restored to a normal state without interrupting the power to the second load 103.

[0076] [2. Second embodiment]

[0077] [2-1. Configuration of power supply equipment]

[0078] Now, refer to Figure 7 The configuration of a power supply device according to the second embodiment is described. Figure 7 1 is an explanatory diagram showing a configuration example of a power supply device according to a second embodiment. Figure 7 The components shown are Figure 1 The same components as shown are used with Figure 1 The same reference numerals are used to designate the same reference numerals to avoid repeated description thereof.

[0079] like Figure 7 As shown, the power supply device 1a according to the second embodiment is Figure 1 The power supply device 1 shown differs in that it comprises a suppression circuit 61a instead of Figure 1 The suppression circuit 61 shown controls the determination unit 3 a on the battery switch 42 .

[0080] The suppression circuit 61a includes a power storage circuit 62a. For example, the power storage circuit 62a is charged with the power supplied from the first power source 10 and supplies the stored power to the second system 120. The power storage circuit 62a is, for example, a capacitor 63a.

[0081] If a ground fault 200 is detected in either the first system 110 or the second system 120, the determination unit 3a turns off the intersystem switch 41. At this time, the battery switch 42 is in the off state. Therefore, if the intersystem switch 41 is off, the capacitor 63a discharges, thereby supplying power to the second system 120.

[0082] Therefore, the determination unit 3 a can determine whether a ground fault has occurred in the second system 120 using the power stored in the capacitor 63 a without using the power of the second power source 20 .

[0083] Now, refer to Figures 8 to 11 The operation of the power supply device 1a is described. Figures 8 to 11 In order to facilitate understanding of the operation of the power supply device 1a, the determination unit 3a, the self-driving control device 100, and Figure 7 The control signal lines indicated by dotted arrows are not shown.

[0084] [2-2. Normal operation of power supply equipment]

[0085] During a normal time when there is no ground fault in the first system 110 and the second system 120, the determination unit 3a is as follows: Figure 8 As shown, the inter-system switch 41 is turned on and the battery switch 42 is turned off, so that power is supplied from the first power source 10 to the first load 101, the general load 102, and the second load 103. At this time, the capacitor 63a is charged with power supplied from the first power source 10.

[0086] [2-3. Ground fault system determination operation of power supply equipment]

[0087] like Figure 9 As shown, similar to the first embodiment, if at least one of the voltages detected by the voltage sensors 51 and 52 becomes equal to or lower than the ground fault threshold value 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. Subsequently, the determination unit 3a determines in which of the first system 110 and the second system 120 the ground fault 200 has occurred.

[0088] After the inter-system switch 41 is disconnected, if the voltage detected by the voltage sensor 51 recovers 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. In addition, if the voltage detected by the voltage sensor 51 continues to be equal to or lower than the ground fault threshold for a predetermined time T, the determination unit 3a determines that a ground fault 200 has occurred in the first system 110, and determines that an abnormality has occurred in the first system 110.

[0089] Furthermore, in the power supply apparatus 1a, if the inter-system switch 41 is turned off, the capacitor 63a is discharged, thereby supplying power for ground fault detection to the second system 120. At this time, the battery switch 42 is in the off state, so the second power supply 20 is not discharged.

[0090] If the voltage detected by the voltage sensor 52 recovers to a voltage higher than the ground fault threshold value within the predetermined time T due to the power supplied from the capacitor 63 a to the second system 120, the determination unit 3 a determines that there is no ground fault 200 in the second system 120. Furthermore, if the voltage detected by the voltage sensor 52 continues to be equal to or lower than the ground fault threshold value within the predetermined time T, the determination unit 3 a determines that a ground fault 200 has occurred in the first system 120, and determines that an abnormality has occurred in the second system 120.

[0091] As described above, if a ground fault of the first system 110 or the second system 120 is detected, the power supply apparatus 1a supplies the power for ground fault detection output from the capacitor 63a disconnected from the second power source 20 to the second system 120 to determine whether the ground fault 200 exists in the second system 120. Therefore, the power supply apparatus 1a can determine whether the ground fault is the ground fault 200 of the second system 120 by making the discharge amount of the second power source 20 zero.

[0092] [2-4. Operation of power supply equipment during the first system ground fault]

[0093] Now, refer to Figure 10 The operation of the power supply device 1a during the first system ground fault is described. Figure 10 As shown, if a ground fault 200 of the first system 110 is detected and determined, the determining unit 3a is Figure 9 The state shown turns on the battery switch 42. As a result, the power supply device 1a supplies power from the second power source 20 to the second load 103, so that the second load 103 can evacuate the vehicle.

[0094] [2-5. Operation of power supply equipment during a second system ground fault]

[0095] Now, refer to Figure 11The operation of the power supply device 1a during the second system ground fault is described. Figure 11 As shown, if a ground fault 200 of the second system 120 is detected and determined, the determination unit 3a supplies power from the first power source 10 to the first load 101 while keeping the battery switch 42 in the open state, so that the first load 101 can evacuate the vehicle.

[0096] If it is determined that no ground fault has occurred in any of the first system 110 and the second system 120, the determination unit 3a determines that this is a detection error caused by a temporal overload, noise, etc. attributed to the first load 101, the second load 103, etc., and turns on the inter-system switch 41, thereby restoring the power supply device to a normal state.

[0097] [2-6. Processing Performed by Determination Unit of Power Supply Device]

[0098] Now, refer to Figure 12 An example of processing performed by the determination unit of the power supply device according to the second embodiment is described. Figure 12 is a flowchart illustrating an example of processing performed by a determination unit of the power supply device according to the second embodiment.

[0099] During normal operation of the vehicle in an active state, the determination unit 3a performs Figure 12 As shown in the following example. Figure 12 As shown, if the vehicle is activated, the determination unit 3a first determines whether any ground fault of the first system 110 or the second system 120 has been detected (step S201).

[0100] If it is determined that no ground fault has been detected in the first system 110 or the second system 120 ("No" in step S201), the determination unit 3a repeats the determination process of step S201 until a ground fault is detected. Meanwhile, if it is determined that a ground fault has been detected in the first system 110 or the second system 120 ("Yes" in step S201), the determination unit 3a turns off the inter-system switch 41 (step S202) and determines whether a ground fault has occurred in the first system 110 (step S203).

[0101] If it is determined that a ground fault has occurred in the first system 110 ("Yes" in step S203), the determination unit 3a turns on the battery switch 42 (step S204) to supply power from the second power supply 20 to the second load 103, and ends the process. Meanwhile, if it is determined that no ground fault has occurred in the first system 110 ("No" in step S203), the determination unit 3a determines whether any ground fault has occurred in the second system 120 (step S205).

[0102] If it is determined that a ground fault has occurred in the second system 120 ("Yes" in step S205), the determination unit 3a determines that an abnormality has occurred in the second system 120, supplies power from the first power source 10 to the first load 101, and terminates the process. At this time, the battery switch 42 is in the off state, so the second power source 20 is not discharged.

[0103] Meanwhile, if it is determined that no ground fault has occurred in the second system 120 ("No" in step S205), the determination unit 3a determines that this is a detection error caused by time overload, noise, etc., and turns on the inter-system switch 41 (step S206), thereby restoring the power supply device to a normal state.

[0104] Various advantages and modifications may be readily realized by those skilled in the art. Therefore, the present invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Therefore, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0105] [Explanation of Reference Numerals]

[0106] 1.1a Power supply equipment

[0107] 10 First Power Source

[0108] 11 DC / DC

[0109] 12 Lead Batteries

[0110] 20 Second power supply

[0111] 21 Lithium-ion battery

[0112] 3.3a Determine the unit

[0113] 41 Inter-system switch

[0114] 42 Battery switch

[0115] 43 spare switch

[0116] 51, 52 Voltage sensor

[0117] 61, 61a suppression circuit

[0118] 62 Current limiting circuit

[0119] 62a Storage circuit

[0120] 63 resistors

[0121] 63a capacitor

[0122] 100 Self-driving control equipment

[0123] 101 First Load

[0124] 102 General Load

[0125] 103 Second load

[0126] 110 First System

[0127] 120 Second system.

Claims

1. A power supply device, comprising: a first system configured to provide power from a first power source to a first load; a second system configured to provide power from a second power source to a second load; an inter-system switch configured to be able to connect and disconnect between the first system and the second system; a determining unit configured to maintain the inter-system switch in an on state during normal operation so that power from the first power source is supplied to the first load and the second load, and in response to detecting a ground fault in the first system or the second system during the normal operation, turn off the inter-system switch, and after the turning off, determine whether the ground fault occurs in the first system or the second system; as well as a suppression circuit configured to simultaneously: (i) suppress discharge of the second power source, and (ii) provide power to the second system for ground fault detection, wherein the determination unit determines whether any ground fault has occurred in the second system based on the power supplied from the suppression circuit to the second system.

2. The power supply device according to claim 1, further comprising: a battery switch configured to be able to connect and disconnect between the second power source and the second system, wherein the suppression circuit includes a current limiting circuit configured to limit current output from the second power supply and to provide power for the ground fault detection to the second system, and When the ground fault of the first system or the second system is detected, the determination unit turns on the battery switch and determines whether any ground fault has occurred in the second system based on power supplied from the current limiting circuit to the second system.

3. The power supply device according to claim 1 , further comprising: a battery switch configured to be able to connect and disconnect between the second power source and the second system, wherein the suppression circuit includes a power storage circuit configured to provide the second system with power stored in the power storage circuit, and When the ground fault of the first system or the second system is detected, the determination unit turns off the battery switch and determines whether any ground fault has occurred in the second system based on the power supplied from the power storage circuit to the second system.

4. A determination method comprising: The determining unit of the power supply device is caused to maintain an inter-system switch in an on state during normal operation so that power from a first power source is supplied to a first load and a second load, and in response to detecting a ground fault in the first system or the second system during the normal operation, to turn off the inter-system switch, and after the turning off, to determine whether the ground fault occurs in the first system or the second system, wherein the power supply device includes: a first system configured to supply power from the first power source to the first load; a second system configured to supply power from the second power source to the second load; and the inter-system switch configured to be capable of connecting and disconnecting between the first system and the second system. causing a suppression circuit of the power supply device to simultaneously: (i) suppress discharge of the second power supply, and (ii) provide power to the second system for ground fault detection, and The determination unit of the power supply device is caused to determine whether any ground fault has occurred in the second system based on the power supplied from the suppression circuit to the second system.

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