Vehicle power source system

Abstract

To provide a vehicle power supply system that is able to specify a place where an anomaly occurs when the anomaly occurs in supply of electrical power.SOLUTION: A vehicle power supply system mounted on a vehicle, comprises: a first power supply connected to a load group of a first system so as to be capable of supplying electric power; a second power supply connected to a load group of a second system so as to be capable of supplying electric power; a first switch inserted between the first power supply and a first load belonging to the load group of the first system; a second switch inserted between the second power supply and a second load belonging to the load group of the second system; a third switch inserted between the first power supply and the second power supply; and a control unit configured to control conduction / cutoff states of the first switch, the second switch, and the third switch. When an anomaly occurs in supply of electric power, the control unit controls the first switch, the second switch, and the third switch and specifies a place where the anomaly occurs based on a current flowing through the first switch and a current flowing through the second switch.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a vehicle power supply system that controls power supply from multiple power sources mounted on a vehicle. [Background technology]

[0002] Patent Document 1 discloses a vehicle power supply system in which a main power supply system to which an auxiliary power supply is connected and a backup power supply system to which a high-voltage power supply is connected are electrically connected via a switch. This vehicle power supply system describes that, if an abnormality occurs in one of the systems, the switch is turned off to isolate the abnormal system, and the vehicle continues to operate using the other system that is not abnormal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-032346 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the vehicle power supply system described in Patent Document 1 above can determine whether an abnormality has occurred in the main power supply system or the backup power supply system, but cannot identify where in the system the abnormality has occurred.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a vehicle power supply system that, when an abnormality occurs in the power supply, can identify the location where the abnormality has occurred. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the disclosed technology is a vehicle power supply system mounted on a vehicle, comprising: a first power supply connected to a load group of a first system so as to be able to supply power; a second power supply connected to a load group of a second system so as to be able to supply power; a first switch inserted between the first power supply and a first load belonging to the load group of the first system; a second switch inserted between the second power supply and a second load belonging to the load group of the second system; a third switch inserted between the first power supply and the second power supply; and a controller that controls the conductive / cut-off states of the first switch, the second switch, and the third switch when an abnormality occurs in the power supply, and identifies the location where the abnormality has occurred based on the current flowing through the first switch and the current flowing through the second switch. Effect of the Invention

[0007] According to the vehicle power supply system of the present disclosure, when an abnormality occurs in the power supply, the switching between the conductive state and the cut-off state of each switch is appropriately controlled to observe changes in the current flowing through the first switch and the second switch. Based on the changes in the current, it is possible to further narrow down and identify a specific location where an abnormality occurs in which an overcurrent flows due to a ground fault or the like, from the broad scope of the system. [Brief description of the drawings]

[0008] [Figure 1] A functional block diagram of a vehicle power supply system and its peripheral parts according to a first embodiment of the present disclosure. [Figure 2A] 1 is a flowchart showing a process for switch control executed by a vehicle power supply system according to a first embodiment when an abnormality occurs; [Figure 2B] 1 is a flowchart showing a process for switch control executed by a vehicle power supply system according to a first embodiment when an abnormality occurs; [Diagram 3] A functional block diagram of a vehicle power supply system and its peripheral parts according to a second embodiment of the present disclosure. [Figure 4A] 11 is a flowchart showing a process for switch control executed by a vehicle power supply system according to a second embodiment when an abnormality occurs. [Figure 4B] 11 is a flowchart showing a process for switch control executed by a vehicle power supply system according to a second embodiment when an abnormality occurs. [Figure 4C] 11 is a flowchart showing a process for switch control executed by a vehicle power supply system according to a second embodiment when an abnormality occurs. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The vehicle power supply system according to the present disclosure uses a switch inserted in front of a load, and if an abnormality occurs in the power supply in the system, it is determined whether or not an abnormality has occurred below the switch based on the change in the current that flows when the switch is on / off. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0010] <First embodiment> [composition] FIG. 1 is a functional block diagram of a vehicle power supply system 10 according to a first embodiment of the present disclosure and its peripheral parts. The functional block illustrated in FIG. 1 includes the vehicle power supply system 10, a first system load group 410, and a second system load group 420. The vehicle power supply system 10 includes a first power source 110, a second power source 120, a first SW 210, a second SW 220, a third SW 230, and a control unit 300. The first system load group 410 includes a first system a load 411, a first system b load 412, a first system steering control load 413, a first system brake control load 414, and a first system driving support control load 415. The second system load group 420 includes a second system c load 421, a second system d load 422, a second system steering control load 423, a second system brake control load 424, and a second system driving support control load 425. The vehicle power supply system 10, the first group of loads 410, and the second group of loads 420 may be mounted on a vehicle.

[0011] The first power source 110 is a power supply source for supplying power to the load group 410 of the first system and the load group 420 of the second system. This first power source 110 is connected to the load group 410 side of the first system. Examples of the first power source 110 include a secondary battery (high voltage battery) configured to be chargeable and dischargeable, such as a lithium ion battery, and a DC-DC converter (DDC) that converts the power of a secondary battery (not shown) to a predetermined voltage.

[0012] The second power source 120 is a power supply source for supplying power to the load group 410 of the first system and the load group 420 of the second system. This second power source 120 is connected to the load group 420 side of the second system. An example of the second power source 120 is a secondary battery (auxiliary battery) configured to be chargeable and dischargeable, such as a lithium ion battery or a lead storage battery.

[0013] The first SW 210 is a switching element (such as a semiconductor switch) that can switch between an electrically conductive state and a cut-off state based on the control of the control unit 300. The first SW 210 is inserted between the first power source 110 and a first system b load 412 (first load) belonging to the load group 410 of the first system.

[0014] The second SW 220 is a switching element (such as a semiconductor switch) that can switch between an electrically conductive state and a cut-off state based on the control of the control unit 300. The second SW 220 is inserted between the second power supply 120 and a second system d load 422 (second load) belonging to the load group 420 of the second system.

[0015] The third SW 230 is a switching element (such as a semiconductor switch) that can switch between an electrically conductive state and an electrically cut-off state based on the control of the control unit 300. This third SW 230 is inserted between the first power source 110 and the second power source 120. In other words, the third SW 230 connects the first system of loads 410 and the second system of loads 420 so as to enable mutual transmission and reception of power.

[0016] The control unit 300 is configured to monitor the state of power supply in the vehicle power supply system 10 and control (switch) the conductive / cut-off states of the first SW 210, the second SW 220, and the third SW 230. The control unit 300 can detect the occurrence of an abnormality in the power supply of the vehicle power supply system 10 based on a change in the output voltage VDDC of the first power supply 110 or a change in the output voltage VLiB of the second power supply 120. The control unit 300 can also identify the location where the abnormality has occurred based on a change in the current I1 flowing through the first SW 210 or a change in the current I2 flowing through the second SW 220.

[0017] The first-system load group 410 is a group consisting of loads that operate using the first power source 110 as a power source when the control unit 300 controls the third SW 230 to be in an interrupted state. In the first-system load group 410, the first-system a load 411 and the first-system b load 412 are in-vehicle devices that do not require a redundant power supply configuration. Here, the first-system b load 412 to which the first SW 210 is provided can be an in-vehicle device such as a heater that does not affect the safety of vehicle driving even if the supply of power is stopped during the period in which the control unit 300 performs the abnormality determination process. The first-system steering control load 413 is a device for controlling the steering of the vehicle, the first-system brake control load 414 is a device for controlling the brake control load of the vehicle, and the first-system driving assistance control load 415 is a device for controlling the automatic driving of the vehicle, and each of these is an in-vehicle device that requires a redundant power supply configuration.

[0018] The second system load group 420 is a group consisting of loads that operate using the second power source 120 as a power source when the third SW 230 is controlled to be in an interrupted state by the control unit 300. In the second system load group 420, the second system c load 421 and the second system d load 422 are in-vehicle devices that do not require a redundant power supply configuration. Here, the second system d load 422 to which the second SW 220 is provided can be a load that does not affect the safety of vehicle driving even if the supply of power is stopped during the period in which the control unit 300 performs the abnormality determination process. The second system steering control load 423 is a device of the same configuration provided for backup of the first system steering control load 413, the second system brake control load 424 is a device of the same configuration provided for backup of the first system brake control load 414, and the second system driving support control load 425 is a device of the same configuration provided for backup of the first system driving support control load 415.

[0019] The number of loads belonging to the first load group 410 and the number of loads belonging to the second load group 420 mounted on the vehicle are not limited to those shown in FIG.

[0020] [control] Next, the operation of the vehicle power supply system 10 according to the first embodiment of the present disclosure will be described with further reference to Figures 2A and 2B. Figures 2A and 2B are flowcharts illustrating a process procedure for switch control when an abnormality occurs, which is executed by the vehicle power supply system 10. The process of Figure 2A and the process of Figure 2B are connected by a connector X.

[0021] 2A and 2B is started when the control unit 300 determines that an abnormality has occurred in the power supply of the vehicle power supply system 10. This determination can be made by detecting, for example, a decrease in the output voltage VDDC of the first power supply 110 or a decrease in the output voltage VLiB of the second power supply 120.

[0022] (Step S201) The control unit 300 controls the first SW 210, the second SW 220, and the third SW 230 to be all in an interrupted state. This control separates the load group 410 of the first system from the load group 420 of the second system, making it easier to determine in which system an abnormality has occurred. When the first SW 210, the second SW 220, and the third SW 230 are all controlled to be in an interrupted state, the process proceeds to step S202.

[0023] (Step S202) The control unit 300 judges whether the output voltage VDDC of the first power supply 110 is greater than the third threshold Vth1. This judgment is made to check whether there is an abnormality in the first system. Therefore, the third threshold Vth1 is set to a predetermined voltage value that is expected to drop if an abnormality occurs in the first system. If it is judged that the output voltage VDDC is greater than the third threshold Vth1 (step S202, Yes), the process proceeds to step S203. On the other hand, if it is judged that the output voltage VDDC is equal to or less than the third threshold Vth1 (step S202, No), the process proceeds to step S204.

[0024] (Step S203) The control unit 300 judges whether the output voltage VLiB of the second power supply 120 is greater than the fourth threshold Vth2. This judgment is made to check the presence or absence of an abnormality in the second system. Therefore, the fourth threshold Vth2 is set to a predetermined voltage value that is expected to drop if an abnormality occurs in the second system. If it is judged that the output voltage VLiB is greater than the fourth threshold Vth2 (step S203, Yes), the process proceeds to step S206. On the other hand, if it is judged that the output voltage VLiB is equal to or less than the fourth threshold Vth2 (step S203, No), the process proceeds to step S205.

[0025] (Step S204) The control unit 300 determines that an abnormality has occurred in the first system. Then, the control unit 300 causes the vehicle to perform a predetermined evacuation running using the second power source 120 and the load group 420 of the second system. When it is determined that an abnormality has occurred in the first system and evacuation running is performed using the second system, the switch control at the time of occurrence of this abnormality ends.

[0026] (Step S205) The control unit 300 determines that an abnormality has occurred in the second system. Then, the control unit 300 causes the vehicle to perform a predetermined evacuation running using the first power source 110 and the load group 410 of the first system. When it is determined that an abnormality has occurred in the second system and evacuation running is performed using the first system, the switch control during the occurrence of this abnormality ends.

[0027] (Step S206) The control unit 300 controls the first SW 210 to be in a conductive state. This control enables power supply from the first power source 110 to the first system b load 412 (first load). When the first SW 210 is controlled to be in a conductive state, the process proceeds to step S207.

[0028] (Step S207) The control unit 300 judges whether the current I1 flowing through the first SW 210 is less than the first threshold Ith1. This judgment is made to check the presence or absence of an abnormality, such as a ground fault, in the connection line under the first SW 210. Therefore, the first threshold Ith1 is set to a predetermined current value that is expected to flow if the connection line under the first SW 210 has a ground fault. If it is judged that the current I1 is less than the first threshold Ith1 (step S207, Yes), the process proceeds to step S208. On the other hand, if it is judged that the current I1 is equal to or greater than the first threshold Ith1 (step S207, No), the process proceeds to step S209.

[0029] (Step S208) The control unit 300 sets a conduction flag for the first SW 210. This conduction flag is a flag for specifying that the switch is controlled to be in a conductive state after a series of abnormality determination processes are completed. When the conduction flag is set for the first SW 210, the process proceeds to step S210.

[0030] (Step S209) The control unit 300 determines that an abnormality has occurred in the connection line under the first SW 210, i.e., the connection path of the first system b load 412 (first load). Then, the control unit 300 sets a cutoff flag for the first SW 210. This cutoff flag is a flag for specifying that the switch is controlled to a cutoff state after a series of abnormality determination processes are completed. When the cutoff flag is set for the first SW 210, the process proceeds to step S210.

[0031] (Step S210) The control unit 300 controls the first SW 210 to be in an interrupted state and the second SW 220 to be in a conductive state. This control enables power supply from the second power source 120 to the second system d load 422 (second load). When the first SW 210 is controlled to be in an interrupted state and the second SW 220 is controlled to be in a conductive state, the process proceeds to step S211.

[0032] (Step S211) The control unit 300 judges whether the current I2 flowing through the second SW 220 is less than the second threshold Ith2. This judgment is made to check the presence or absence of an abnormality, such as a ground fault, in the connection line under the second SW 220. Therefore, the second threshold Ith2 is set to a predetermined current value that is expected to flow if the connection line under the second SW 220 has a ground fault. If it is judged that the current I2 is less than the second threshold Ith2 (step S211, Yes), the process proceeds to step S212. On the other hand, if it is judged that the current I2 is equal to or greater than the second threshold Ith2 (step S211, No), the process proceeds to step S213.

[0033] (Step S212) The control unit 300 sets a continuity flag for the second SW 220. When the continuity flag for the second SW 220 is set, the process proceeds to step S214.

[0034] (Step S213) The control unit 300 determines that an abnormality has occurred in the connection line under the second SW 220, that is, the connection path of the second system d load 422 (second load). Then, the control unit 300 sets a cutoff flag for the second SW 220. When the cutoff flag is set for the second SW 220, the process proceeds to step S214.

[0035] (Step S214) The control unit 300 controls the second SW 220 to be in the cut-off state. With this control, the abnormality determination process is completed. When the second SW 220 is controlled to be in the cut-off state, the process proceeds to step S215.

[0036] (Step S215) The control unit 300 controls the first SW 210 and the second SW 220 to a conductive state or a cut-off state based on the flags set for each SW, and controls the third SW 230 to a conductive state. When the connection states of the first SW 210, the second SW 220, and the third SW 230 are controlled, the switch control during the occurrence of the abnormality is terminated.

[0037] According to the switch control when an abnormality occurs according to the first embodiment described above, when an abnormality occurs in the power supply and the first and second systems are separated, the first system b load 412 and the second system d load 422, which do not affect the safety of vehicle driving when stopped for a short time, are also stopped to eliminate unnecessary power consumption. This makes it possible to avoid a situation in which it is not possible to perform abnormality determination processing for each system due to a power shortage (such as at low temperatures) in the first power source 110 or the second power source 120.

[0038] Furthermore, according to the switch control when an abnormality occurs according to the first embodiment, when the power supply to the first system b load 412 and the second system d load 422 is stopped by the first SW 210 and the second SW 220, the presence or absence of an abnormality in the connection path is also determined. This makes it possible to prevent the occurrence of a hunting phenomenon in which an abnormality is determined again when a normal state is restored due to an erroneous determination and the first SW 210 or the second SW 220 is made conductive.

[0039] <Second embodiment> [composition] Fig. 3 is a functional block diagram of a vehicle power supply system 20 according to a second embodiment of the present disclosure and its peripheral parts. The functional block illustrated in Fig. 3 includes the vehicle power supply system 20, a first system load group 410, and a second system load group 420. The vehicle power supply system 20 includes a first power supply 110, a second power supply 120, a first SW 210, a second SW 220, a third SW 230, SW 510, SW 520, a plurality of SW(1) 611, SW 612-614, a plurality of SW(2) 621, SW 622-624, and a control unit 300. The first system load group 410 includes a first system a load 411, a plurality of first system b loads 412, a first system steering control load 413, a first system brake control load 414, and a first system driving assistance control load 415. The second system load group 420 includes a second system c load 421, a plurality of second system d loads 422, a second system steering control load 423, a second system brake control load 424, and a second system driving assistance control load 425. The vehicle power supply system 20, the first system load group 410, and the second system load group 420 may be mounted on a vehicle.

[0040] The first power source 110 is a power supply source for supplying power to the load group 410 of the first system and the load group 420 of the second system. This first power source 110 is connected to the load group 410 side of the first system. Examples of the first power source 110 include a secondary battery (high voltage battery) configured to be chargeable and dischargeable, such as a lithium ion battery or a lead storage battery, and a DC-DC converter (DDC) that converts the power of a secondary battery (not shown) to a predetermined voltage.

[0041] The second power source 120 is a power supply source for supplying power to the load group 410 of the first system and the load group 420 of the second system. This second power source 120 is connected to the load group 420 of the second system. An example of the second power source 120 is a secondary battery (auxiliary battery) configured to be chargeable and dischargeable, such as a lithium ion battery.

[0042] The first SW 210, the second SW 220, the third SW 230, SW510, SW520, the plurality of SW(1) 611, SW612-614, the plurality of SW(2) 621, and SW622-624 are each a switching element (such as a semiconductor switch) that can switch between an electrically conductive state and a cut-off state based on the control of the control unit 300. Among these, SW510, SW520, the plurality of SW(1) 611, SW612-614, the plurality of SW(2) 621, and SW622-624 are provided to play a role of protection (fuse function) in the event of a ground fault in the wire harness (W / H).

[0043] The first SW 210 is inserted between the first power source 110 and a plurality of first system b loads 412 (a plurality of first loads) belonging to the first system load group 410. The second SW 220 is inserted between the second power source 120 and a plurality of second system d loads 422 (a plurality of second loads) belonging to the second system load group 420. The third SW 230 is inserted between the first power source 110 and the second power source 120. The SW 510 is inserted between the first power source 110 and the first system load group 410. The SW 520 is inserted between the second power source 120 and the second system load group 420. A plurality of SW(1) 611 are provided corresponding to the plurality of first system b loads 412, and are inserted between the first SW 210 and each of the first system b loads 412. The SW 612 is inserted between the SW 510 and the first system steering control load 413. SW613 is inserted between SW510 and the first system brake control load 414. SW614 is inserted between SW510 and the first system driving assistance control load 415. A plurality of SW(2)621 are provided corresponding to a plurality of second system d loads 422, and are inserted between the second SW220 and each of the second system d loads 422. SW622 is inserted between SW520 and the second system steering control load 423. SW623 is inserted between SW520 and the second system brake control load 424. SW624 is inserted between SW520 and the second system driving assistance control load 425.

[0044] The control unit 300 is configured to monitor the state of power supply in the vehicle power supply system 20 and control (switch) the conductive / cut-off state of the first SW 210, the second SW 220, the third SW 230, SW 510, SW 520, the plurality of SW(1) 611, SW 612-614, the plurality of SW(2) 621, and SW 622-624. The control unit 300 can detect the occurrence of an abnormality in the power supply of the vehicle power supply system 10 based on a change in the output voltage VDDC of the first power supply 110 or a change in the output voltage VLiB of the second power supply 120. The control unit 300 can also identify the location where the abnormality has occurred based on a change in the current I1 flowing through the first SW 210 or a change in the current I2 flowing through the second SW 220.

[0045] The first-system load group 410 is a group consisting of loads that operate using the first power source 110 as a power source when the third SW 230 is controlled to be in an interrupted state by the control unit 300. In the first-system load group 410, the first-system a load 411 and the first-system b loads 412 are in-vehicle devices that do not require a redundant power supply configuration. Here, the first-system b loads 412 to which the first SW 210 is provided can be in-vehicle devices such as heaters that do not affect the safety of vehicle driving even if the supply of power is stopped during a period in which the control unit 300 performs an abnormality determination process. The first-system steering control load 413 is a device for controlling the steering of the vehicle, the first-system brake control load 414 is a device for controlling the brakes of the vehicle, and the first-system driving assistance control load 415 is a device for controlling automatic driving of the vehicle, and each of these is an in-vehicle device that requires a redundant power supply configuration.

[0046] The second system load group 420 is a group consisting of loads that operate using the second power source 120 as a power source when the third SW 230 is controlled to be in an interrupted state by the control unit 300. In the second system load group 420, the second system c load 421 and the multiple second system d loads 422 are in-vehicle devices that do not require a redundant power supply configuration. Here, the multiple second system d loads 422 to which the second SW 220 is provided can be loads that do not affect the safety of vehicle driving even if the supply of power is stopped during a period in which the control unit 300 performs an abnormality determination process. The second system steering control load 423 is a device of the same configuration provided for backup of the first system steering control load 413, the second system brake control load 424 is a device of the same configuration provided for backup of the first system brake control load 414, and the second system driving support control load 425 is a device of the same configuration provided for backup of the first system driving support control load 415.

[0047] In addition, the number of loads belonging to the first system load group 410 mounted on the vehicle, the number of loads belonging to the second system load group 420, the number of multiple first system b loads 412, and the number of multiple second system d loads 422 are not limited to those shown in Figure 3.

[0048] [control] Next, the operation of the vehicle power supply system 20 according to the second embodiment of the present disclosure will be described with further reference to Figures 4A, 4B, and 4C. Figures 4A, 4B, and 4C are flowcharts illustrating a process procedure for switch control when an abnormality occurs, which is executed by the vehicle power supply system 20. The process of Figure 4A and the process of Figure 4B are connected by a connector Y, and the process of Figure 4B and the process of Figure 4C are connected by a connector Z.

[0049] 4A, 4B, and 4C is started by control unit 300 determining that an abnormality has occurred in the power supply of vehicle power supply system 20. This determination can be made, for example, by detecting a drop in output voltage VDDC of first power supply 110 or a drop in output voltage VLiB of second power supply 120. It is assumed that SW510, SW520, multiple SW(1) 611, SW612-614, multiple SW(2) 621, and SW622-624 are controlled to be in a conductive state.

[0050] (Step S401) The control unit 300 controls the first SW 210, the second SW 220, and the third SW 230 to be all in an interrupted state. This control separates the load group 410 of the first system from the load group 420 of the second system, making it easier to determine in which system an abnormality has occurred. When the first SW 210, the second SW 220, and the third SW 230 are all controlled to be in an interrupted state, the process proceeds to step S402.

[0051] (Step S402) The control unit 300 controls all of the multiple SW(1) 611 connected under the first SW 210 to be in an interrupted state, and controls all of the multiple SW(2) 621 connected under the second SW 220 to be in an interrupted state. This control stops power supply to the multiple first system b loads 412 and the multiple second system d loads 422. When all of the multiple SW(1) 611 and the multiple SW(2) 621 are controlled to be in an interrupted state, the process proceeds to step S403.

[0052] (Step S403) The control unit 300 judges whether the output voltage VDDC of the first power supply 110 is greater than the third threshold Vth1. This judgment is made to check whether there is an abnormality in the first system. Therefore, the third threshold Vth1 is set to a predetermined voltage value that is expected to drop if an abnormality occurs in the first system. If it is judged that the output voltage VDDC is greater than the third threshold Vth1 (step S403, Yes), the process proceeds to step S404. On the other hand, if it is judged that the output voltage VDDC is equal to or less than the third threshold Vth1 (step S403, No), the process proceeds to step S405.

[0053] (Step S404) The control unit 300 judges whether the output voltage VLiB of the second power supply 120 is greater than the fourth threshold Vth2. This judgment is made to check the presence or absence of an abnormality in the second system. Therefore, the fourth threshold Vth2 is set to a predetermined voltage value that is expected to drop if an abnormality occurs in the second system. If it is judged that the output voltage VLiB is greater than the fourth threshold Vth2 (step S404, Yes), the process proceeds to step S407. On the other hand, if it is judged that the output voltage VLiB is equal to or less than the fourth threshold Vth2 (step S404, No), the process proceeds to step S406.

[0054] (Step S405) The control unit 300 determines that an abnormality has occurred in the first system. Then, the control unit 300 causes the vehicle to perform a predetermined evacuation running using the second power source 120 and the load group 420 of the second system. When it is determined that an abnormality has occurred in the first system and evacuation running is performed using the second system, the switch control at the time of occurrence of this abnormality ends.

[0055] (Step S406) The control unit 300 determines that an abnormality has occurred in the second system. Then, the control unit 300 causes the vehicle to perform a predetermined evacuation running using the first power source 110 and the load group 410 of the first system. When it is determined that an abnormality has occurred in the second system and evacuation running is performed using the first system, the switch control during the occurrence of this abnormality ends.

[0056] (Step S407) The control unit 300 controls the first SW 210 to be in a conductive state. This control enables power to be supplied from the first power source 110 to the multiple first system b loads 412 (first loads) via the multiple SW(1) 611. When the first SW 210 is controlled to be in a conductive state, the process proceeds to step S408.

[0057] (Step S408) The control unit 300 controls only one of the multiple SW(1) 611, “SW(1)-i”, to be in a conductive state (i is any value from 1 to n, which is the total number of SW(1) 611). When SW(1)-i is controlled to be in a conductive state, the process proceeds to step S409.

[0058] (Step S409) The control unit 300 judges whether the current I1 flowing through the first SW 210 is less than the first threshold Ith1. This judgment is made to check the presence or absence of an abnormality, such as a ground fault, in the connection line under the first SW 210. Therefore, the first threshold Ith1 is set to a predetermined current value that is expected to flow if the connection line under the first SW 210 has a ground fault. If it is judged that the current I1 is less than the first threshold Ith1 (step S409, Yes), the process proceeds to step S410. On the other hand, if it is judged that the current I1 is equal to or greater than the first threshold Ith1 (step S409, No), the process proceeds to step S411.

[0059] (Step S410) The control unit 300 sets a continuity flag for SW(1)-i. This continuity flag is a flag for specifying that the switch is controlled to a conductive state after a series of abnormality determination processes are completed. When the continuity flag is set for SW(1)-i, the process proceeds to step S408.

[0060] (Step S411) The control unit 300 determines that an abnormality has occurred in the connection line that is subordinate to the first SW 210 and also subordinate to SW(1)-i. Then, the control unit 300 sets a cutoff flag for SW(1)-i. This cutoff flag is a flag for specifying that the switch is controlled to a cutoff state after a series of abnormality determination processes are completed. When the cutoff flag is set for SW(1)-i, the process proceeds to step S408.

[0061] The SW(1) switching operation shown in steps S408 to S411 above is repeated until it is performed for all of the multiple SW(1) 611 (SW(1)-1 to SW(1)-n).

[0062] (Step S412) The control unit 300 controls the first SW 210 to be in an interrupted state and the second SW 220 to be in a conductive state. This control enables power to be supplied from the second power source 120 to a plurality of second system d loads 422 (second loads) via a plurality of SW(2) 621. When the first SW 210 is controlled to be in an interrupted state and the second SW 220 is controlled to be in a conductive state, the process proceeds to step S413.

[0063] (Step S413) The control unit 300 controls only one of the multiple SW(2) 621, "SW(2)-j," to be in a conductive state (j is any value from 1 to m, which is the total number of SW(2) 621). When SW(2)-j is controlled to be in a conductive state, the process proceeds to step S414.

[0064] (Step S414) The control unit 300 judges whether the current I2 flowing through the second SW 220 is less than the second threshold Ith2. This judgment is made to check the presence or absence of an abnormality, such as a ground fault, in the connection line under the second SW 220. Therefore, the second threshold Ith2 is set to a predetermined current value that is expected to flow if the connection line under the second SW 220 has a ground fault. If it is judged that the current I2 is less than the second threshold Ith2 (step S414, Yes), the process proceeds to step S415. On the other hand, if it is judged that the current I2 is equal to or greater than the second threshold Ith2 (step S414, No), the process proceeds to step S416.

[0065] (Step S415) The control unit 300 sets a continuity flag for SW(2)-j. This continuity flag is a flag for specifying that the switch is controlled to be in a conductive state after a series of abnormality determination processes are completed. When the continuity flag is set for SW(2)-j, the process proceeds to step S413.

[0066] (Step S416) The control unit 300 determines that an abnormality has occurred in the connection line that is subordinate to the second SW 220 and also subordinate to SW(2)-j. Then, the control unit 300 sets a cutoff flag for SW(2)-j. This cutoff flag is a flag for specifying that the switch is controlled to a cutoff state after a series of abnormality determination processes are completed. When the cutoff flag is set for SW(2)-j, the process proceeds to step S413.

[0067] The SW(2) switching operation shown in steps S413 to S416 above is repeated until it is performed for all of the multiple SW(2) 621 (SW(2)-1 to SW(2)-m).

[0068] (Step S417) The control unit 300 controls the second SW 220 to be in the cut-off state. With this control, the abnormality determination process is completed. When the second SW 220 is controlled to be in the cut-off state, the process proceeds to step S418.

[0069] (Step S418) The control unit 300 controls the first SW 210, the second SW 220, and the third SW 230 to a conductive state, and controls the plurality of SW(1) 611 and the plurality of SW(2) 621 to a conductive state or a cut-off state based on flags set for each of them. When the connection states of the first SW 210, the second SW 220, the third SW 230, the plurality of SW(1) 611, and the plurality of SW(2) 621 are each controlled, the switch control during the occurrence of this abnormality ends.

[0070] According to the switch control when an abnormality occurs according to the second embodiment described above, when an abnormality occurs in the power supply and the first and second systems are separated, the first system b loads 412 and the second system d loads 422, which do not affect the safety of vehicle driving when stopped for a short time, are also stopped to eliminate unnecessary power consumption. This makes it possible to avoid a situation in which it is not possible to perform abnormality determination processing for each system due to a power shortage (such as at low temperatures) in the first power source 110 or the second power source 120.

[0071] Furthermore, according to the switch control when an abnormality occurs according to the second embodiment, the conductive / cut-off state of the plurality of SW(1) 611 and the plurality of SW(2) 621 subordinate to the plurality of SW(1) 611 and the plurality of SW(2) 621 is controlled based on the presence or absence of an abnormality in the connection path. If the control (cut-off instruction, etc.) of the plurality of SW(1) 611 and the plurality of SW(2) 621 is performed using a signal terminal of a conventional microcomputer, the control unit 300 only needs to control the first SW 210, the second SW 220, and the third SW 230, and the circuit scale of the vehicle power supply system 20 can be reduced.

[0072] <Actions and Effects> As described above, the vehicle power supply systems 10 and 20 according to each embodiment of the present disclosure include a first SW 210 inserted between the first power source 110 connected to the first system load group 410 and the first system b load 412 belonging to the first system load group 410, a second SW 220 inserted between the second power source 120 connected to the second system load group 420 and the second system d load 422 belonging to the second system load group 420, and a third SW 230 inserted between the first power source 110 and the second power source 120, and the conductive / cut-off states of the first SW 210, the second SW 220, and the third SW 230 are appropriately controlled by the control unit 300.

[0073] With this control, if an abnormality occurs in the power supply, the location under the first SW 210 of the first system can be identified as the location where the abnormality has occurred based on a change in the current I1 flowing through the first SW 210 when the first SW 210 is conductive and cut off. Also, if an abnormality occurs in the power supply, the location under the second SW 220 of the second system can be identified as the location where the abnormality has occurred based on a change in the current I2 flowing through the second SW 220 when the second SW 220 is conductive and cut off. Then, by identifying the location where the abnormality has occurred, the location where the abnormality has occurred can be cut off and power supply can be restored to other locations other than the location where the abnormality has occurred.

[0074] The above describes embodiments of the disclosed technology, but the present disclosure can be understood as not only a vehicle power supply system but also a control method performed by a vehicle power supply system, a program for the control method, a computer-readable non-transitory storage medium storing the program, a vehicle equipped with a vehicle power supply system, and the like. [Industrial Applicability]

[0075] The vehicle power supply system of the present disclosure can be used for power supply control of a vehicle or the like that is equipped with a first power supply connected to a load group of a first system so as to be able to supply power, and a second power supply connected to a load group of a second system so as to be able to supply power. [Explanation of symbols]

[0076] 10, 20 Vehicle power supply system 110 1st power supply 120 2nd power supply 210 1st SW 220 2nd SW 230 Third Switch 300 Control section 410 Load group of the first system 420 Load group of the second system 411~415, 421~425 Load 510, 520, 611~614, 621~624 SW

Claims

1. A vehicle power supply system mounted on a vehicle, a first power supply connected to a first system of loads so as to be able to supply electric power; a second power supply connected to the loads of a second system so as to be able to supply electric power; a first switch inserted between the first power source and a first load belonging to the load group of the first system; a second switch inserted between the second power source and a second load belonging to the second load group; a third switch inserted between the first power source and the second power source; a control unit that controls the conductive / cut-off states of the first switch, the second switch, and the third switch, the control unit controls the first switch, the second switch, and the third switch when an abnormality occurs in the power supply, and identifies a location where the abnormality has occurred based on a current flowing through the first switch and a current flowing through the second switch. Vehicle power system.

2. When an abnormality occurs in the power supply, the control unit turns off the third switch, acquiring a current flowing through the first switch when the first switch is turned on and off, and, if a change in the current flowing through the first switch is equal to or greater than a first threshold, identifying a location below the first switch as a location where an abnormality has occurred; a current flowing through the second switch when the second switch is turned on and off is acquired, and when a change in the current flowing through the second switch is equal to or greater than a second threshold, a portion below the second switch is identified as a location where an abnormality has occurred; 10. The vehicle power system of claim 1.

3. When the control unit identifies a location under the first switch as a location where an abnormality has occurred, the control unit controls the first switch to a cut-off state, and when the control unit identifies a location under the second switch as a location where an abnormality has occurred, the control unit controls the second switch to a cut-off state.

3. The vehicle power supply system of claim 2.

4. The first load and the second load are loads that do not affect safety of vehicle driving even if the supply of power is stopped during a period in which the abnormality determination process is performed by the control unit.

4. A vehicle power supply system according to claim 1.

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