Power supply control device

Abstract

To provide a power supply control device capable of suppressing a power supplied from a second power supply without stopping a power supply to a second load during an initial check.SOLUTION: A power supply control device according to an embodiment includes an inter-system switch that connects a first system that supplies a power from a first power supply to a first load and a second system that supplies a power from a second power supply to a second load; a battery switch that connects the second power supply to the second system; a backup circuit; and a controller. The backup circuit is provided to the second system, and is constructed by parallely connecting a DC-DC converter and a backup switch. The backup switch contains a pair of switching elements of which a direction of a parasitic diode is inversely connected, each other. The controller performs an off-fixing check of each switching element of which a cathode of the parasitic diode contained in the backup switch is connected to the second power supply side in a period when an ignition switch in an OFF.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] There is a redundant power supply system that includes an inter-system switch that connects a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load, and a battery switch that connects the second power source and the second system.

[0003] The redundant power supply system normally supplies power from the first power supply to the first load and the second load with the inter-system switch turned on and the battery switch turned off. If an abnormality occurs in the first system, the redundant power supply system performs a fail-safe operation by turning off the inter-system switch, turning on the battery switch, and supplying power from the second power supply to the second load.

[0004] In order to check whether the fail-safe operation can be performed normally, such a redundant power supply system performs an initial check to determine whether the inter-system switch and the battery switch are stuck at startup. For example, Patent Document 1 discloses a redundant power supply system that performs an initial check while preventing the power supply to the second load from being interrupted. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-111637 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the redundant power supply system described in this prior art document, power from the second power supply is used when determining whether the battery switch is stuck, and so the remaining charge of the second power supply decreases during the initial check.

[0007] One aspect of the embodiment has been made in consideration of the above, and aims to provide a power supply control device that can suppress power supply from a second power source without interrupting power supply to a second load during an initial check. [Means for solving the problem]

[0008] A power supply control device according to an embodiment includes an inter-system switch, a battery switch, a backup circuit, and a controller. The inter-system switch connects a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load. The battery switch connects the second power source to the second system. The backup circuit is provided in the second system and includes a DC-DC converter and a backup switch connected in parallel to the DC-DC converter. The controller controls the inter-system switch, the battery switch, and the backup switch, and performs a stuck-off check to determine whether or not at least the backup switch is stuck in a cut-off state. The backup switch includes a pair of switching elements connected such that the orientations of parasitic diodes are opposite to each other. When the controller performs a stuck-off check of one switching element in which a cathode of a parasitic diode included in the backup switch is connected to the second power source side, the controller turns on the inter-system switch during a period when an ignition switch is off. The controller turns on the battery switch. The controller turns on the one switching element while turning off the other switching element included in the backup switch. The controller performs the stuck-off check based on a voltage across the one switching element. Effect of the Invention

[0009] A power supply control device according to an aspect of the embodiment provides an advantage in that it is possible to suppress power supply from the second power supply without interrupting the power supply to the second load during an initial check. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram illustrating an example of the configuration of a power supply control device according to an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing a normal state of the power supply control device according to the embodiment. [Diagram 3] FIG. 3 is an explanatory diagram showing a state when an abnormality occurs in the first system of the power supply control device according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Diagram 5] FIG. 5 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 6] FIG. 6 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 7] FIG. 7 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 8] FIG. 8 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 9] FIG. 9 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 10] FIG. 10 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 11] FIG. 11 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 12] FIG. 12 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 13] FIG. 13 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 14] FIG. 14 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 15] FIG. 15 is an explanatory diagram of the initial check executed by the power supply control device according to the embodiment. [Figure 16] FIG. 16 is a flowchart showing the initial check process of the first example executed by the controller according to the embodiment. [Figure 17] FIG. 17 is a flowchart showing the initial check process of the second example executed by the controller according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a power supply control device will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiment described below. In the following, a case where a vehicle equipped with a power supply control device according to the embodiment is an electric vehicle or a hybrid vehicle will be described.

[0012] The vehicle in which the power supply control device according to the embodiment is installed may be an engine vehicle that runs on an internal combustion engine. The power supply control device according to the embodiment is a device that is installed in a vehicle with an automatic driving function and supplies power to a load.

[0013] [1. Power supply control device configuration] The configuration of a power supply control device according to an embodiment will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram showing an example of the configuration of a power supply control device 1 according to an embodiment. Fig. 1 shows the state of the power supply control device 1 when the ignition switch of a vehicle is turned off.

[0014] As shown in FIG. 1, the power supply control device 1 is connected to a first power supply 10, a DC / DC converter (hereinafter referred to as "DCDC11"), an ignition switch (hereinafter referred to as "IG12"), a first load 101, and a second load 102.

[0015] The first power source 10 is, for example, a lead battery capable of outputting a voltage of 12 V. The first power source 10 may be any secondary battery other than a lead battery. The DCDC 11 is connected to an alternator and a high-voltage battery.

[0016] The alternator is a generator that converts the kinetic energy of a running vehicle into electricity to generate electricity. The high-voltage battery is a battery for driving the vehicle. The DCDC 11 boosts or lowers the voltage input from the alternator or the high-voltage battery and supplies it to the power supply control device 1.

[0017] When the vehicle is started, the IG 12 transmits a start signal to the power supply control device 1. Furthermore, when the vehicle start-up is ended, the IG 12 transmits an end signal to the power supply control device 1.

[0018] The first load 101 includes a load for autonomous driving. The load for autonomous driving includes, for example, a steering motor, an electric brake device, an in-vehicle camera, and the like that operate during autonomous driving. Furthermore, the first load 101 includes a load that is not involved in autonomous driving. The load that is not involved in autonomous driving includes, for example, a display, an air conditioner, an audio device, a video device, various lights, and the like.

[0019] The second load 102 has some of the functions for automatic driving that the first load 101 has. The second load 102 includes, for example, a steering motor, an electric brake device, and a device that is minimally required for FOP (Fail Operation, evacuation drive control), such as a radar. The first load 101 and the second load 102 operate using power supplied from the power supply control device 1.

[0020] The power supply control device 1 includes a second power supply 20, an inter-system switch 31, a battery switch 32, a backup circuit 33, a dark current switch 34, and a controller 3. The second power supply 20 is a backup power supply in case the first power supply 10 is unable to supply power. The second power supply 20 is, for example, a lithium ion battery. The second power supply 20 may be any secondary battery other than a lithium ion battery.

[0021] The inter-system switch 31 connects a first system 110 that supplies power from the first power source 10 to the first load 101, and a second system 120 that supplies power from the second power source 20 to the second load 102. Specifically, the inter-system switch 31 is made conductive by being turned on, and electrically connects the first system 110 and the second system 120. The inter-system switch 31 is also cut off by being turned off, and cuts off the electrical connection between the first system 110 and the second system 120.

[0022] The inter-system switch 31 includes a first switching element 41 and a second switching element 42. The first switching element 41 and the second switching element 42 are, for example, field effect transistors (FETs). The first switching element 41 and the second switching element 42 are connected in series such that the orientations of their parasitic diodes are different from each other.

[0023] Here, the anodes of the parasitic diodes of the first switching element 41 and the second switching element 42 are connected to each other. The cathode side of the parasitic diode of the first switching element 41 is connected to the first system 110. The cathode side of the parasitic diode of the second switching element 42 is connected to the second system 120.

[0024] The battery switch 32 connects the second power source 20 to the second system 120. Specifically, the battery switch 32 is conductive when turned on, and electrically connects the second power source 20 and the second system 120. The battery switch 32 is cut off when turned off, and cuts off the electrical connection with the second system 120.

[0025] The battery switch 32 includes a third switching element 43 and a fourth switching element 44. The third switching element 43 and the fourth switching element 44 are, for example, FETs. The third switching element 43 and the fourth switching element 44 are connected in series such that the orientations of their parasitic diodes are different from each other.

[0026] Here, the anodes of the parasitic diodes of the third switching element 43 and the fourth switching element 44 are connected to each other. The cathode side of the parasitic diode of the third switching element 43 is connected to the second power supply. The cathode side of the parasitic diode of the fourth switching element 44 is connected to the backup circuit 33.

[0027] The backup circuit 33 is provided in the second system 120 and includes a DCDC converter 35 (hereinafter, referred to as "DCDC 35") and a backup switch 36 connected in parallel to the DCDC 35. The DCDC 35 boosts or lowers the voltage input from the first power supply 10 side and outputs it to the second power supply side.

[0028] The backup switch 36 is conductive when turned on, and electrically connects the battery switch 32 and the second system 120. The backup switch 36 is cut off when turned off, and cuts off the electrical connection between the battery switch 32 and the second system 120.

[0029] The backup switch 36 includes a fifth switching element 45 and a sixth switching element 46. The fifth switching element 45 and the sixth switching element 46 are, for example, FETs. The fifth switching element 45 and the sixth switching element 46 are connected in series such that the orientations of their parasitic diodes are different from each other.

[0030] Here, the anodes of the parasitic diodes of the fifth switching element 45 and the sixth switching element 46 are connected to each other. The cathode side of the parasitic diode of the fifth switching element 45 is connected to the battery switch 32. The cathode side of the parasitic diode of the sixth switching element 46 is connected to the inter-system switch 31, the dark current switch 34, and the second load 102.

[0031] The dark current switch 34 connects the first system 110 and the second system 120 while the IG 12 of the vehicle is turned off, and supplies a minimum necessary weak current from the first power source 10 to the first load 101 and the second load 102.

[0032] In this way, since the dark current switch 34 is a switch for passing a weak current, a switch having a lower withstand voltage and lower cost is adopted compared to the inter-system switch 31 that passes a relatively large current.

[0033] The dark current switch 34 is turned on to conduct electricity and electrically connect the first system 110 and the second system 120. The dark current switch 34 is turned off to cut off electricity and cut off the electrical connection between the first system 110 and the second system 120.

[0034] The dark current switch 34 includes a seventh switching element 47 and an eighth switching element 48. The seventh switching element 47 and the eighth switching element 48 are, for example, FETs. The seventh switching element 47 and the eighth switching element 48 are connected in series such that the orientations of their parasitic diodes are different from each other.

[0035] Here, the anodes of the parasitic diodes of the seventh switching element 47 and the eighth switching element 48 are connected to each other. The cathode side of the parasitic diode of the seventh switching element 47 is connected to the first system 110. The cathode side of the parasitic diode of the eighth switching element 48 is connected to the second system 120.

[0036] The power supply control device 1 further includes first to ninth voltage sensors 51 to 59. The first voltage sensor 51 detects the voltage of the connection line connecting the first system 110 and the inter-system switch 31, and outputs the detection result to the controller 3.

[0037] The second voltage sensor 52 detects the voltage of the connection line connecting the first switching element 41 and the second switching element 42, and outputs the detection result to the controller 3. The third voltage sensor 53 detects the voltage of the connection line connecting the second power source 20 and the battery switch 32, and outputs the detection result to the controller 3.

[0038] The fourth voltage sensor 54 detects the voltage of the connection line connecting the third switching element 43 and the fourth switching element 44, and outputs the detection result to the controller 3. The fifth voltage sensor 55 detects the voltage of the connection line connecting the battery switch 32 and the backup circuit 33, and outputs the detection result to the controller 3.

[0039] The sixth voltage sensor 56 detects the voltage of the connection line connecting the fifth switching element 45 and the sixth switching element 46, and outputs the detection result to the controller 3. The seventh voltage sensor 57 detects the voltage of the connection line connecting the backup circuit 33 with the inter-system switch 31, the dark current switch 34, and the second load 102, and outputs the detection result to the controller 3.

[0040] The eighth voltage sensor 58 detects the voltage of the connection line connecting the dark current switch 34 and the first system 110, and outputs the detection result to the controller 3. The ninth voltage sensor 59 detects the voltage of the connection line connecting the seventh switching element 47 and the eighth switching element 48, and outputs the detection result to the controller 3.

[0041] The controller 3 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like, and various other circuits.

[0042] The controller 3 controls the inter-system switch 31, the battery switch 32, the backup switch 36, and the dark current switch 34 by the CPU executing a program stored in the ROM using the RAM as a working area.

[0043] The controller 3 may be configured in part or in whole using hardware such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0044] When the controller 3 receives the end signal from the IG 12, it puts the power supply control device 1 into the state shown in Fig. 1. Specifically, when the IG 12 is turned off, the controller 3 stops outputting control signals to the inter-system switch 31, the battery switch 32, the backup switch 36, and the dark current switch 34.

[0045] As a result, in the power supply control device 1, the inter-system switch 31, the battery switch 32, and the backup switch 36 are cut off, and the dark current switch 34 is in a conductive state. In this way, the inter-system switch 31, the battery switch 32, and the backup switch 36 are normally open type switches. On the other hand, the dark current switch 34 is a normally closed type switch.

[0046] [2. Normal state of the power supply control device] Next, the normal state of the power supply control device 1 will be described with reference to Fig. 2. Fig. 2 is an explanatory diagram showing the normal state of the power supply control device 1 according to the embodiment.

[0047] 2, in normal operation after receiving a start-up signal from the IG 12, the controller 3 turns off the battery switch 32, the backup switch 36, and the dark current switch 34, and turns on the inter-system switch 31. In this way, the power supply control device 1 supplies power to the first load 101 and the second load 102 from the first power supply 10 or the DCDC 11.

[0048] [3. Power supply control device first system abnormality state] Next, the state of the power supply control device 1 when the first system is abnormal will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram showing the state of the power supply control device 1 according to the embodiment when the first system is abnormal.

[0049] 3, in the power supply control device 1, an abnormality 100 may occur in the first system 110 due to some cause during normal operation. The abnormality 100 occurring in the first system 110 may be, for example, a disconnection or a ground fault.

[0050] When an abnormality 100 occurs in the first system 110, the power supply control device 1 cannot supply power from the first power source 10 or the DCDC 11 to the first load 101 and the second load 102 if the normal state remains.

[0051] Therefore, when an abnormality 100 occurs in the first system 110, the controller 3 performs a fail-safe operation by disconnecting the inter-system switch 31 and the dark current switch 34 and connecting the battery switch 32 and the backup switch 36, as shown in FIG. 3.

[0052] As a result, even if an abnormality 100 occurs in the first system 110 during autonomous driving, the power supply control device 1 can supply power from the second power source 20 to the second load 102, so that the second load 102 can be used to perform evacuation driving and the vehicle can be stopped in a safe place.

[0053] However, if the inter-system switch 31, the battery switch 32, the backup switch 36, or the dark current switch 34 is stuck in a conductive or cut-off state, the power supply control device 1 may not be able to perform fail-safe operation.

[0054] Therefore, while the vehicle is not running, the controller 3 executes an initial check to determine whether or not the inter-system switch 31, the battery switch 32, the backup switch 36, and the dark current switch 34 have a stuck fault. A specific example of the initial check executed by the controller 3 will be described below.

[0055] [4. First Example of Initial Check] 4 to 15 are explanatory diagrams of the initial check executed by the power supply control device 1 according to the embodiment. In the following, a fault where the switch is stuck in the conductive state is referred to as "stuck on," and a fault where the switch is stuck in the cut-off state is referred to as "stuck off." The controller 3 according to the first embodiment executes the initial check when the IG12 changes from on to off.

[0056] First, the controller 3 checks whether the seventh switching element 47, the eighth switching element 48, the third switching element 43, and the sixth switching element 46 are stuck on. In this case, the controller 3 turns on the inter-system switch 31 and turns off the battery switch 32, the backup switch 36, and the dark current switch 34, as shown in FIG.

[0057] This enables the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also enables the controller 3 to suppress the power supply from the second power source 20.

[0058] At this time, if the seventh switching element 47 is fixed on, the voltage of the first power source 10 is applied to the eighth voltage sensor 58, and the voltage of the first power source 10 is applied to the ninth voltage sensor 59 via the seventh switching element 47. Therefore, the voltage detected by the eighth voltage sensor 58 and the voltage detected by the ninth voltage sensor 59 become substantially equal. Also, if the eighth switching element 48 is fixed on, the voltage of the first power source 10 is applied to the eighth voltage sensor 58, and the voltage of the first power source 10 is applied to the ninth voltage sensor 59 via the inter-system switch 31 and the eighth switching element 48. Therefore, the voltage detected by the eighth voltage sensor 58 and the voltage detected by the ninth voltage sensor 59 become substantially equal.

[0059] On the other hand, if both the seventh switching element 47 and the eighth switching element 48 are normal, the voltage of the first power supply 10 is applied to the eighth voltage sensor 58, and no voltage is applied to the ninth voltage sensor 59. Therefore, a large difference appears between the voltage detected by the eighth voltage sensor 58 and the voltage detected by the ninth voltage sensor 59.

[0060] Therefore, if the absolute value of the difference between the voltage detected by the eighth voltage sensor 58 and the voltage detected by the ninth voltage sensor 59 is greater than a predetermined value, the controller 3 determines that the seventh switching element 47 and the eighth switching element 48 are not stuck on. Note that the predetermined value here is a value slightly smaller than the voltage value of the first power source 10.

[0061] Furthermore, if the third switching element 43 is stuck on, the voltage of the second power supply 20 is applied to the third voltage sensor 53, and the voltage of the second power supply 20 is applied to the fourth voltage sensor 54 via the third switching element 43. Therefore, the voltage detected by the third voltage sensor 53 and the voltage detected by the fourth voltage sensor 54 become substantially equal.

[0062] On the other hand, if the third switching element 43 is normal, the voltage of the second power supply 20 is applied to the third voltage sensor 53, and no voltage is applied to the fourth voltage sensor 54. Therefore, a large difference appears between the voltage detected by the third voltage sensor 53 and the voltage detected by the fourth voltage sensor 54.

[0063] Therefore, if the absolute value of the difference between the voltage detected by the third voltage sensor 53 and the voltage detected by the fourth voltage sensor 54 is greater than a predetermined value, the controller 3 determines that the third switching element 43 is not stuck on. Note that the predetermined value here is a value slightly lower than the voltage value of the second power supply 20.

[0064] Furthermore, if the sixth switching element 46 is stuck on, the voltage of the first power supply 10 is applied to the seventh voltage sensor 57 via the inter-system switch 31, and the voltage of the first power supply 10 is applied to the sixth voltage sensor 56 via the inter-system switch 31 and the sixth switching element 46. Therefore, the voltage detected by the sixth voltage sensor 56 and the voltage detected by the seventh voltage sensor 57 become substantially equal.

[0065] On the other hand, if sixth switching element 46 is normal, the voltage of first power supply 10 is applied to seventh voltage sensor 57, and no voltage is applied to sixth voltage sensor 56. Therefore, a large difference appears between the voltage detected by sixth voltage sensor 56 and the voltage detected by seventh voltage sensor 57.

[0066] Therefore, if the absolute value of the difference between the voltage detected by the sixth voltage sensor 56 and the voltage detected by the seventh voltage sensor 57 is greater than a predetermined value, the controller 3 determines that the sixth switching element 46 is not stuck on. Note that the predetermined value here is a value slightly smaller than the voltage value of the first power supply 10.

[0067] Next, the controller 3 checks whether the first switching element 41 and the second switching element 42 are stuck on. In this case, as shown in FIG 5, the controller 3 turns off the inter-system switch 31, the battery switch 32, and the backup switch 36, and turns on the dark current switch 34.

[0068] This enables the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also enables the controller 3 to suppress the power supply from the second power source 20.

[0069] At this time, if the first switching element 41 is stuck on, the voltage of the first power supply 10 is applied to the first voltage sensor 51, and the voltage of the first power supply 10 is applied to the second voltage sensor 52 via the first switching element 41. Therefore, the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52 are approximately equal. Also, if the second switching element 42 is stuck on, the voltage of the first power supply 10 is applied to the first voltage sensor 51, and the voltage of the first power supply 10 is applied to the second voltage sensor 52 via the dark current switch 34 and the second switching element 42. Therefore, the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52 are approximately equal.

[0070] On the other hand, if both the first switching element 41 and the second switching element 42 are normal, the voltage of the first power supply 10 is applied to the first voltage sensor 51, and no voltage is applied to the second voltage sensor 52. Therefore, a large difference appears between the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52.

[0071] Therefore, if the absolute value of the difference between the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52 is greater than a predetermined value, the controller 3 determines that the first switching element 41 and the second switching element 42 are not stuck on. Note that the predetermined value here is a value slightly smaller than the voltage value of the first power source 10.

[0072] Next, the controller 3 checks whether the fourth switching element 44 is stuck on. In this case, as shown in FIG 6, the controller 3 turns off the inter-system switch 31 and the battery switch 32, and turns on the backup switch 36 and the dark current switch 34.

[0073] This enables the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also enables the controller 3 to suppress the power supply from the second power source 20.

[0074] At this time, if the fourth switching element 44 is stuck on, the voltage of the first power supply 10 is applied to the fifth voltage sensor 55 via the dark current switch 34 and the backup switch 36. Also, the voltage of the first power supply 10 is applied to the fourth voltage sensor 54 via the dark current switch 34, the backup switch 36, and the fourth switching element 44. Therefore, the voltage detected by the fourth voltage sensor 54 and the voltage detected by the fifth voltage sensor 55 become substantially equal.

[0075] On the other hand, if the fourth switching element 44 is normal, the voltage of the first power supply 10 is applied to the fifth voltage sensor 55, and no voltage is applied to the fourth voltage sensor 54. Therefore, a large difference appears between the voltage detected by the fourth voltage sensor 54 and the voltage detected by the fifth voltage sensor 55.

[0076] Therefore, if the absolute value of the difference between the voltage detected by the fourth voltage sensor 54 and the voltage detected by the fifth voltage sensor 55 is greater than a predetermined value, the controller 3 determines that the fourth switching element 44 is not stuck on. Note that the predetermined value here is a value slightly smaller than the voltage value of the second power supply 20.

[0077] Next, the controller 3 checks whether the fifth switching element 45 is stuck on. In this case, as shown in FIG 7, the controller 3 turns off the inter-system switch 31 and the backup switch 36, and turns on the battery switch 32 and the dark current switch 34.

[0078] This enables the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also enables the controller 3 to suppress the power supply from the second power source 20.

[0079] At this time, if the fifth switching element 45 is stuck on, the voltage of the second power supply 20 is applied to the fifth voltage sensor 55 via the battery switch 32, and the voltage of the second power supply 20 is applied to the sixth voltage sensor 56 via the battery switch 32 and the fifth switching element 45. Therefore, the voltage detected by the fifth voltage sensor 55 and the voltage detected by the sixth voltage sensor 56 become approximately equal.

[0080] On the other hand, if fifth switching element 45 is normal, the voltage of second power supply 20 is applied to fifth voltage sensor 55, and no voltage is applied to sixth voltage sensor 56. Therefore, a large difference appears between the voltage detected by fifth voltage sensor 55 and the voltage detected by sixth voltage sensor 56.

[0081] Therefore, the controller 3 determines that the fifth switching element 45 is not stuck on if the absolute value of the difference between the voltage detected by the fifth voltage sensor 55 and the voltage detected by the sixth voltage sensor 56 is greater than a predetermined value. The predetermined value here is a value slightly smaller than the voltage value of the second power supply 20.

[0082] Next, the controller 3 checks whether the seventh switching element 47 is stuck off. In this case, the controller 3 turns on the inter-system switch 31 and turns off the battery switch 32 and the backup switch 36, as shown in FIG.

[0083] Furthermore, the controller 3 turns on the seventh switching element 47 and turns off the eighth switching element 48. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also allows the controller 3 to suppress the power supply from the second power source 20.

[0084] At this time, if seventh switching element 47 is stuck off, the voltage of first power supply 10 is applied to eighth voltage sensor 58, and no voltage is applied to ninth voltage sensor 59. Therefore, a large difference appears between the voltage detected by eighth voltage sensor 58 and the voltage detected by ninth voltage sensor 59.

[0085] On the other hand, if seventh switching element 47 is normal, the voltage of first power supply 10 is applied to eighth voltage sensor 58 and ninth voltage sensor 59. Therefore, the voltage detected by eighth voltage sensor 58 and the voltage detected by ninth voltage sensor 59 are substantially equal to each other.

[0086] Therefore, the controller 3 determines that the seventh switching element 47 is not stuck off if the absolute value of the difference between the voltage detected by the eighth voltage sensor 58 and the voltage detected by the ninth voltage sensor 59 is smaller than a predetermined value. The predetermined value here is a value slightly larger than 0V.

[0087] Next, the controller 3 checks whether the eighth switching element 48 is stuck off. In this case, the controller 3 turns on the inter-system switch 31 and turns off the battery switch 32 and the backup switch 36, as shown in FIG.

[0088] Furthermore, the controller 3 turns off the seventh switching element 47 and turns on the eighth switching element 48. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also allows the controller 3 to suppress the power supply from the second power source 20.

[0089] At this time, if eighth switching element 48 is stuck off, the voltage of first power supply 10 is applied to seventh voltage sensor 57 via inter-system switch 31, and no voltage is applied to ninth voltage sensor 59. Therefore, a large difference appears between the voltage detected by seventh voltage sensor 57 and the voltage detected by ninth voltage sensor 59.

[0090] On the other hand, if eighth switching element 48 is normal, the voltage of first power supply 10 is applied to seventh voltage sensor 57 via inter-system switch 31, and the voltage of first power supply 10 is applied to ninth voltage sensor 59 via inter-system switch 31 and eighth switching element 48. Therefore, the voltage detected by seventh voltage sensor 57 and the voltage detected by ninth voltage sensor 59 are substantially equal to each other.

[0091] Therefore, if the absolute value of the difference between the voltage detected by the ninth voltage sensor 59 and the voltage detected by the seventh voltage sensor 57 is smaller than a predetermined value, the controller 3 determines that the eighth switching element 48 is not stuck off. Note that the predetermined value here is a value slightly larger than 0V.

[0092] Next, the controller 3 checks whether the first switching element 41 is stuck off. In this case, the controller 3 turns off the battery switch 32 and the backup switch 36, and turns on the dark current switch 34, as shown in FIG.

[0093] Furthermore, the controller 3 turns on the first switching element 41 and turns off the second switching element 42. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also allows the controller 3 to suppress the power supply from the second power source 20.

[0094] At this time, if the first switching element 41 is stuck off, the voltage of the first power supply 10 is applied to the first voltage sensor 51, and no voltage is applied to the second voltage sensor 52. Therefore, a large difference appears between the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52.

[0095] On the other hand, if the first switching element 41 is normal, the voltage of the first power supply 10 is applied to the first voltage sensor 51, and the voltage of the first power supply 10 is applied to the second voltage sensor 52 via the first switching element 41. Therefore, the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52 are substantially equal to each other.

[0096] Therefore, the controller 3 determines that the first switching element 41 is not stuck off if the absolute value of the difference between the voltage detected by the first voltage sensor 51 and the voltage detected by the second voltage sensor 52 is smaller than a predetermined value. Note that the predetermined value here is a value slightly larger than 0V.

[0097] Next, the controller 3 checks whether the second switching element 42 is stuck off. In this case, the controller 3 turns off the battery switch 32 and the backup switch 36, and turns on the dark current switch 34, as shown in FIG.

[0098] Furthermore, the controller 3 turns off the first switching element 41 and turns on the second switching element 42. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-on check, and also allows the controller 3 to suppress the power supply from the second power source 20.

[0099] At this time, if the second switching element 42 is stuck off, the voltage of the first power supply 10 is applied to the seventh voltage sensor 57 via the dark current switch 34, and no voltage is applied to the second voltage sensor 52. Therefore, a large difference appears between the voltage detected by the seventh voltage sensor 57 and the voltage detected by the second voltage sensor 52.

[0100] On the other hand, if the second switching element 42 is normal, the voltage of the first power supply 10 is applied to the seventh voltage sensor 57 via the dark current switch 34, and the voltage of the first power supply 10 is applied to the second voltage sensor 52 via the dark current switch 34 and the second switching element 42. Therefore, the voltage detected by the seventh voltage sensor 57 and the voltage detected by the second voltage sensor 52 are approximately equal.

[0101] Therefore, if the absolute value of the difference between the voltage detected by the second voltage sensor 52 and the voltage detected by the seventh voltage sensor 57 is smaller than a predetermined value, the controller 3 determines that the second switching element 42 is not stuck off. Note that the predetermined value here is a value slightly larger than 0V.

[0102] Next, the controller 3 checks whether the sixth switching element 46 is stuck off. In this case, as shown in Fig. 12, the controller 3 turns off the battery switch 32 and the dark current switch 34, turns on the first switching element 41, and turns off the second switching element 42. Furthermore, the controller 3 turns off the fifth switching element 45 and turns on the sixth switching element 46.

[0103] That is, when the controller 3 performs a stuck-off check of the sixth switching element 46 included in the backup switch 36, the controller 3 turns on the inter-system switch 31. At this time, the second switching element 42 is cut off, but the current flowing through the first system 110 is supplied to the second system 120 via a parasitic diode of the second switching element 42. Note that the second switching element 42 is cut off in preparation for the next stuck-off check of the fifth switching element 45, and the controller 3 may turn on the second switching element 42.

[0104] Furthermore, the controller 3 turns off the battery switch 32, turns off the fifth switching element 45 included in the backup switch , and turns on the sixth switching element included in the backup switch with the fifth switching element 45 being turned off.

[0105] Then, the controller 3 performs a stuck-off check of the sixth switching element 46 included in the backup switch 36 based on the voltage across the sixth switching element 46 included in the backup switch 36. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-off check, and also allows the controller 3 to suppress the power supply from the second power source 20.

[0106] At this time, if sixth switching element 46 is stuck off, the voltage of first power supply 10 is applied to seventh voltage sensor 57 via inter-system switch 31, and no voltage is applied to sixth voltage sensor 56. Therefore, a large difference appears between the voltage detected by sixth voltage sensor 56 and the voltage detected by seventh voltage sensor 57.

[0107] On the other hand, if the sixth switching element 46 is normal, the voltage of the first power source 10 is applied to the seventh voltage sensor 57 via the inter-system switch 31, and the voltage of the first power source 10 is applied to the sixth voltage sensor 56 via the inter-system switch 31 and the sixth switching element 46. Therefore, the voltage detected by the sixth voltage sensor 56 and the voltage detected by the seventh voltage sensor 57 become substantially equal.

[0108] Therefore, if the absolute value of the difference between the voltage detected by the sixth voltage sensor 56 and the voltage detected by the seventh voltage sensor 57 is smaller than a predetermined value, the controller 3 determines that the sixth switching element 46 is not stuck off.

[0109] Next, when IG12 is off, the controller 3 performs a stuck-off check of the fifth switching element 45. In this case, as shown in Fig. 13, the battery switch 32 is made conductive and the dark current switch 34 is cut off. Furthermore, the controller 3 makes the first switching element 41 conductive, cuts off the second switching element 42, makes the fifth switching element 45 conductive, and cuts off the sixth switching element 46.

[0110] That is, when the controller 3 performs a stuck-off check of the fifth switching element 45 in which the cathode of the parasitic diode included in the backup switch 36 is connected to the second power supply side, the controller 3 performs the stuck-off check while IG12 is off.

[0111] In this case, the controller 3 turns on the inter-system switch 31 and turns on the battery switch 32. At this time, the second switching element 42 is cut off, but the current flowing through the first system 110 is supplied to the second system 120 via the parasitic diode of the second switching element 42.

[0112] Furthermore, the controller 3 turns on the fifth switching element 45 while cutting off the sixth switching element 46 included in the backup switch, and performs a stuck-off check based on the voltage across the fifth switching element 45. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-off check.

[0113] At this time, if fifth switching element 45 is stuck off, the voltage of second power supply 20 is applied to fifth voltage sensor 55 via battery switch 32, and no voltage is applied to sixth voltage sensor 56. Therefore, a large difference appears between the voltage detected by fifth voltage sensor 55 and the voltage detected by sixth voltage sensor 56.

[0114] On the other hand, if the fifth switching element 45 is normal, the voltage of the second power supply 20 is applied to the fifth voltage sensor 55 via the battery switch 32, and the voltage of the second power supply 20 is applied to the sixth voltage sensor 56 via the battery switch 32 and the fifth switching element 45. Therefore, the voltage detected by the fifth voltage sensor 55 and the voltage detected by the sixth voltage sensor 56 are approximately equal.

[0115] Therefore, the controller 3 determines that the fifth switching element 45 is not stuck off if the absolute value of the difference between the voltage detected by the fifth voltage sensor 55 and the voltage detected by the sixth voltage sensor 56 is smaller than a predetermined value. Note that the predetermined value here is a value slightly larger than 0V.

[0116] At this time, the sixth switching element 46 is in a cut-off state, but the battery switch 32 and the fifth switching element 45 are conductive, so power is supplied from the second power source 20 to the second load 102 via the parasitic diode of the sixth switching element 46. However, since the IG12 is turned off and the second load 102 is not operating, the amount of power supplied from the second power source 20 to the second load 102 is zero or very small, and the controller 3 can suppress the power supply from the second power source 20.

[0117] As described above, the inter-system switch 31 includes the first switching element 41 and the second switching element 42 connected such that the orientations of the parasitic diodes are opposite to each other. When the controller 3 performs a stuck-off check of the fifth switching element 45, the controller 3 turns on the first switching element 41, the cathode of which of the parasitic diodes included in the inter-system switch is connected to the first system side. The controller 3 turns off the second switching element 42, the cathode of which of the parasitic diodes included in the inter-system switch 31 is connected to the second system side.

[0118] At this time, the first switching element 41 is conductive but the second switching element 42 is cut off, so the current flowing from the second power source 20 through the second system 120 is prevented from flowing into the first system 110 by the parasitic diode of the second switching element 42. This allows the controller 3 to prevent power supply from the second power source 20 to the first system 110.

[0119] As described above, the check for the fifth switching element 45 being stuck in the off state is performed when IG12 is turned off, so the second load 102 is not operating and it is possible to prevent power supply from the second power source 20 to the second load 102. However, some second loads 102 perform a termination process, such as writing data from RAM to flash memory, when IG12 is turned from on to off.

[0120] In this case, if the termination process takes a long time, when the check for stuck-off of the fifth switching element 45 is performed, the load will be in operation, and power will be supplied from the second power source 20 to the second load 102, which may cause a drop in the voltage of the second power source 20.

[0121] Therefore, the controller 3 adjusts the voltage of the first power source 10 so that it is higher than the voltage of the second power source 20, and then controls the inter-system switch 31, the battery switch 32, the backup switch , and the dark current switch .

[0122] As a result, the voltage on the second load 102 side of the sixth switching element 46 becomes higher than the voltage on the second power source 20 side, and the parasitic diode of the sixth switching element 46 becomes non-conductive. Therefore, power is not supplied from the second power source 20 to the second load 102, and the power consumed from the second power source 20 becomes zero. Therefore, the controller 3 can prevent the power supply to the second load 102 from being interrupted during the stuck-off check of the fifth switching element 45, and can suppress the power supply from the second power source 20.

[0123] Next, the controller 3 checks whether the fourth switching element 44 is stuck off. In this case, as shown in Fig. 14, the controller 3 turns on the inter-system switch 31 and the backup switch 36 and turns off the dark current switch 34. Furthermore, the controller 3 turns off the third switching element 43 and turns on the fourth switching element 44.

[0124] That is, when the controller 3 performs a stuck-off check of the fourth switching element 44, in which the anode of the parasitic diode included in the battery switch 32 is connected to the second power source 20 side, the controller 3 makes the inter-system switch 31 conductive and the backup switch 36 conductive. Furthermore, the controller 3 makes the fourth switching element 44 included in the battery switch 32 conductive while keeping the third switching element 43 included in the battery switch 32 cut off.

[0125] The controller 3 then performs a stuck-off check of the fourth switching element 44 included in the battery switch 32 based on the voltage across the fourth switching element 44 included in the battery switch 32. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-off check, and also allows the controller 3 to suppress the power supply from the second power source 20.

[0126] At this time, if the fourth switching element 44 is stuck off, the voltage of the first power source 10 is applied to the fifth voltage sensor 55 via the inter-system switch 31 and the backup switch 36, and no voltage is applied to the fourth voltage sensor 54. Therefore, a large difference appears between the voltage detected by the fourth voltage sensor 54 and the voltage detected by the fifth voltage sensor 55.

[0127] On the other hand, if the fourth switching element 44 is normal, the voltage of the first power supply 10 is applied to the fifth voltage sensor 55, and the voltage of the first power supply 10 is further applied to the fourth voltage sensor 54 via the fourth switching element 44. Therefore, the voltage detected by the fourth voltage sensor 54 and the voltage detected by the fifth voltage sensor 55 become substantially equal.

[0128] Therefore, the controller 3 determines that the fourth switching element 44 is not stuck off if the absolute value of the difference between the voltage detected by the fourth voltage sensor 54 and the voltage detected by the fifth voltage sensor 55 is smaller than a predetermined value. Note that the predetermined value here is a value slightly larger than 0V.

[0129] Next, the controller 3 checks whether the third switching element 43 is stuck off. In this case, as shown in Fig. 15, the controller 3 turns on the inter-system switch 31 and turns off the backup switch 36 and the dark current switch 34. Furthermore, the controller 3 turns on the third switching element 43 and turns off the fourth switching element 44.

[0130] That is, when the controller 3 performs a stuck-off check of the third switching element 43, the cathode of which of the parasitic diode included in the battery switch 32 is connected to the second power source 20 side, the controller 3 makes the inter-system switch 31 conductive and cuts off the backup switch 36. Furthermore, the controller 3 makes the third switching element 43 included in the battery switch 32 conductive while keeping the fourth switching element 44 included in the battery switch 32 cut off.

[0131] The controller 3 then performs a stuck-off check of the third switching element 43 included in the battery switch 32 based on the voltage across the third switching element 43 included in the battery switch 32. This allows the controller 3 to prevent the power supply to the second load 102 from being interrupted during the stuck-off check, and also allows the controller 3 to suppress the power supply from the second power source 20.

[0132] At this time, if the third switching element 43 is stuck off, the voltage of the second power supply 20 is applied to the third voltage sensor 53, and no voltage is applied to the fourth voltage sensor 54. Therefore, a large difference appears between the voltage detected by the third voltage sensor 53 and the voltage detected by the fourth voltage sensor 54.

[0133] On the other hand, if the third switching element 43 is normal, the voltage of the second power supply 20 is applied to the third voltage sensor 53, and the voltage of the second power supply 20 is applied to the fourth voltage sensor 54 via the third switching element 43. Therefore, the voltage detected by the third voltage sensor 53 and the voltage detected by the fourth voltage sensor 54 are substantially equal to each other.

[0134] Therefore, if the absolute value of the difference between the voltage detected by the third voltage sensor 53 and the voltage detected by the fourth voltage sensor 54 is smaller than a predetermined value, the controller 3 determines that the third switching element 43 is not stuck off. Note that the predetermined value here is a value slightly larger than 0V.

[0135] In the above embodiment, the predetermined value used as a threshold for determining whether a switching element is stuck, which is described as being slightly smaller than the voltage value of the first power source 10, may be a voltage value that is half the voltage value of the first power source 10. In the above embodiment, the predetermined value used as a threshold for determining whether a switching element is stuck, which is described as being slightly smaller than the voltage value of the second power source 20, may be a voltage value that is half the voltage value of the second power source 20.

[0136] [5. Processing performed by the controller] Next, the initial check process executed by the controller 3 will be described with reference to FIGS.

[0137] [5-1. Initial check process of the first embodiment] FIG. 16 is a flowchart showing the initial check process of the first example executed by the controller 3 according to the embodiment.

[0138] 16, in the initial check process of the first embodiment, the controller 3 first determines whether or not the IG12 is turned off (step S101). If the controller 3 determines that the IG12 is turned off (step S101, Yes), the controller 3 adjusts the voltage of the first power source 10 so that it is higher than the voltage of the second power source 20 (step S102).

[0139] After that, the controller 3 performs a stuck-on check of each switching element (the first to eighth switching elements 41 to 48) (step S103). Next, the controller 3 performs a stuck-off check of each switching element (the first to eighth switching elements 41 to 48) (step S104).

[0140] Thereafter, the controller 3 stores the check results of each switching element (the first to eighth switching elements 41 to 48) (step S105) and ends the process. At this time, the controller 3 stores the check results in, for example, a non-volatile memory included in the controller 3 itself.

[0141] Moreover, when it is determined that the IG 12 is not turned off (step S101, No), the controller 3 reads out the check result from the non-volatile memory only for the first time after the IG 12 is turned on from off (step S106).

[0142] Then, the controller 3 notifies the automatic driving control device that controls the automatic driving of the vehicle of the check result only for the first time after the IG 12 is turned on from off (step S107), and ends the process.

[0143] At this time, if each switching element (first to eighth switching elements 41 to 48) is normal, the controller 3 notifies the automatic driving control device that automatic driving is possible. Also, if any of the switching elements (first to eighth switching elements 41 to 48) is abnormal, the controller 3 notifies the automatic driving control device that automatic driving is not possible.

[0144] In this way, the controller 3 adjusts the voltage of the first power source 10 to be higher than the voltage of the second power source 20 while the IG12 is off, and then checks whether each switching element (first to eighth switching elements 41 to 48) is normal.

[0145] This allows the controller 3 to prevent power from being supplied from the second power source 20 to some of the loads for which it takes time for the termination process to be completed when the IG 12 is switched from on to off.

[0146] 13 while IG12 is off, the controller 3 stops the operation of the load and prevents power from being supplied to the load from the second power supply 20. However, when IG12 goes from on to off, some loads perform a termination process such as writing data in RAM to flash memory before turning off the power themselves.

[0147] In that case, if the termination process takes a long time, the load will be in operation when the check shown in Fig. 13 is performed, and power will be supplied from the second power source 20. Therefore, as a precaution, the controller 3 adjusts the voltage of the first power source 10 to be higher than the voltage of the second power source 20 while the IG 12 is off. This allows the controller 3 to prevent power from being supplied from the second power source 20 to the load when the check is performed.

[0148] [5-2. Initial check process of the second embodiment] FIG. 17 is a flowchart showing the initial check process of the second example executed by the controller 3 according to the embodiment.

[0149] 17, in the initial check process of the second embodiment, the controller 3 first determines whether or not the IG12 is turned on (step S201). If the controller 3 determines that the IG12 is not turned on (step S201, No), the controller 3 ends the process.

[0150] Furthermore, when it is determined that the IG 12 is turned on (Yes at step S201), the controller 3 adjusts the voltage of the first power source 10 so that it is higher than the voltage of the second power source 20 (step S202).

[0151] After that, the controller 3 performs a stuck-on check of each switching element (the first to eighth switching elements 41 to 48) (step S203). Next, the controller 3 performs a stuck-off check of each switching element (the first to eighth switching elements 41 to 48) (step S204).

[0152] After that, the controller 3 stores the check results of each switching element (the first to eighth switching elements 41 to 48) (step S205). At this time, the controller 3 stores the check results in, for example, a RAM included in the controller 3 itself.

[0153] Then, the controller 3 notifies the automatic driving control device of the check result (step S206) and ends the process. At this time, if each switching element (the first to eighth switching elements 41 to 48) is normal, the controller 3 notifies the automatic driving control device that automatic driving is possible.

[0154] Furthermore, if any of the switching elements (first to eighth switching elements 41 to 48) is abnormal, the controller 3 notifies the automatic driving control device that automatic driving cannot be performed.

[0155] When the IG 12 changes from off to on, the load starts to start up, so that the load is in operation when the controller 3 performs the check shown in FIG.

[0156] Therefore, as described above, when IG12 is turned on, the controller 3 adjusts the voltage of the first power source 10 so that it is higher than the voltage of the second power source 20, and then checks whether each switching element (first to eighth switching elements 41 to 48) is normal. This allows the controller 3 to prevent power from being supplied to the load from the second power source 20 when performing the check.

[0157] [6. Notes] As an appendix, the features of the present invention are as follows. (1) an inter-system switch that connects a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load; a battery switch for connecting the second power source to the second system; A backup circuit provided in the second system includes a DC-DC converter and a backup switch connected in parallel to the DC-DC converter; A power supply control device comprising: a controller that controls the system switch, the battery switch, and the backup switch, and performs a stuck-off check to determine whether or not at least the backup switch is stuck in an interrupted state, The backup switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions to each other, The controller: When a check is performed for a stuck-off state of one of the switching elements in which a cathode of a parasitic diode included in the backup switch is connected to the second power supply side, During a period when an ignition switch is off, the inter-system switch is turned on and the battery switch is turned on; the one switching element is turned on while the other switching element included in the backup switch is turned off, and the stuck-off check is performed based on a voltage across the one switching element. Power control device. (2) The controller: The power supply control device according to (1), wherein, when the stuck-off check is performed, the voltage of the first power supply is adjusted to be higher than the voltage of the second power supply. (3) an inter-system switch that connects a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load; a battery switch for connecting the second power source to the second system; A backup circuit provided in the second system includes a DC-DC converter and a backup switch connected in parallel to the DC-DC converter; A power supply control device including a controller that controls the system switch, the battery switch, and the backup switch, and performs a stuck-off check to determine whether or not at least the backup switch is stuck in an interrupted state, The backup switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions to each other, The controller: When a check is performed for a stuck-off state of one of the switching elements in which a cathode of a parasitic diode included in the backup switch is connected to the second power supply side, adjusting the voltage of the first power source to be higher than the voltage of the second power source to turn on the inter-system switch and turn on the battery switch; the one switching element is turned on while the other switching element included in the backup switch is turned off, and the stuck-off check is performed based on a voltage across the one switching element. Power control device. (4) The controller: The power supply control device according to (3), wherein the stuck-off check is performed while an ignition switch is off. (5) The controller: The power supply control device according to (3), wherein the stuck-off check is performed while an ignition switch is on. (6) The inter-system switch includes a pair of switching elements connected such that the orientations of parasitic diodes are opposite to each other, The controller: When the off-stick check is performed, a cathode of a parasitic diode included in the inter-system switch turns on one of the switching elements connected to the first system side; a cathode of a parasitic diode included in the inter-system switch cuts off the other switching element connected to the second system side; The power supply control device according to any one of (1) to (5). (7) The controller: When performing a stuck-off check of the other switching element included in the backup switch, making the inter-system switch conductive, cutting off the battery switch, and in a state in which the one switching element included in the backup switch is cut off, making the other switching element included in the backup switch conductive; performing a stuck-off check of the other switching element included in the backup switch based on a voltage across both ends of the other switching element included in the backup switch; The power supply control device according to any one of (1) to (6). (8) the battery switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions; The controller: When a check is performed for a stuck-off state of one of the switching elements in which the anode of a parasitic diode included in the battery switch is connected to the second power supply side, making the inter-system switch conductive, making the backup switch conductive, and making the one switching element included in the battery switch conductive while keeping the other switching element included in the battery switch cut off; performing a check for the one of the switching elements included in the battery switch being stuck off based on a voltage across both ends of the one of the switching elements included in the battery switch; The power supply control device according to any one of (1) to (7). (9) the battery switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions; The controller: When a check is performed for a stuck-off state of one of the switching elements in which a cathode of a parasitic diode included in the battery switch is connected to the second power supply side, making the inter-system switch conductive, cutting off the backup switch, and making the one switching element included in the battery switch conductive while cutting off the other switching element included in the battery switch; performing a check for the one of the switching elements included in the battery switch being stuck off based on a voltage across both ends of the one of the switching elements included in the battery switch; The power supply control device according to any one of (1) to (8).

[0158] 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]

[0159] 1 Power supply control device 3. Controller 10 1st power supply 20 2nd power supply 31 Intersystem switch 32 Battery switch 33 Backup circuit 34 Dark current switch 36 Backup switch 41 First switching element 42 Second switching element 43 Third switching element 44 Fourth switching element 45 5th switching element 46 6th switching element 47 Seventh switching element 48 8th switching element 51 First voltage sensor 52 Second voltage sensor 53 Third voltage sensor 54 4th voltage sensor 55 5th voltage sensor 56 6th voltage sensor 57 7th voltage sensor 58 8th voltage sensor 59 9th voltage sensor 100 Abnormal 101 1st load 102 2nd load 110 1st system 120 2nd system

Claims

1. an inter-system switch that connects a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load; a battery switch for connecting the second power source to the second system; a backup circuit provided in the second system, the backup circuit including a DC-DC converter and a backup switch connected in parallel to the DC-DC converter; A power supply control device comprising: a controller that controls the system switch, the battery switch, and the backup switch, and performs a stuck-off check to determine whether or not at least the backup switch is stuck in an interrupted state, The backup switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions to each other, The controller: When a check is performed for a stuck-off state of one of the switching elements in which a cathode of a parasitic diode included in the backup switch is connected to the second power supply side, During a period when an ignition switch is off, the inter-system switch is turned on and the battery switch is turned on; the one switching element is turned on while the other switching element included in the backup switch is turned off, and the stuck-off check is performed based on a voltage across the one switching element. Power control device.

2. The controller:

2. The power supply control device according to claim 1, wherein, when the stuck-off check is performed, the voltage of the first power supply is adjusted to be higher than the voltage of the second power supply.

3. an inter-system switch that connects a first system that supplies power from a first power source to a first load and a second system that supplies power from a second power source to a second load; a battery switch for connecting the second power source to the second system; a backup circuit provided in the second system, the backup circuit including a DC-DC converter and a backup switch connected in parallel to the DC-DC converter; A power supply control device including a controller that controls the system switch, the battery switch, and the backup switch, and performs a stuck-off check to determine whether or not at least the backup switch is stuck in an interrupted state, The backup switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions to each other, The controller: When a check is performed for a stuck-off state of one of the switching elements in which a cathode of a parasitic diode included in the backup switch is connected to the second power supply side, adjusting the voltage of the first power source to be higher than the voltage of the second power source to turn on the inter-system switch and turn on the battery switch; the one switching element is turned on while the other switching element included in the backup switch is turned off, and the stuck-off check is performed based on a voltage across the one switching element. Power control device.

4. The controller:

4. The power supply control device according to claim 3, wherein the stuck-off check is performed while an ignition switch is off.

5. The controller:

4. The power supply control device according to claim 3, wherein the stuck-off check is performed while an ignition switch is on.

6. The inter-system switch includes a pair of switching elements connected such that the orientations of parasitic diodes are opposite to each other, The controller: When the off-stick check is performed, a cathode of a parasitic diode included in the inter-system switch turns on one of the switching elements connected to the first system side; a cathode of a parasitic diode included in the inter-system switch cuts off the other switching element connected to the second system side; The power supply control device according to claim 1 .

7. The controller: When performing a stuck-off check of the other switching element included in the backup switch, making the inter-system switch conductive, cutting off the battery switch, and in a state in which the one switching element included in the backup switch is cut off, making the other switching element included in the backup switch conductive; performing a stuck-off check of the other switching element included in the backup switch based on a voltage across both ends of the other switching element included in the backup switch; The power supply control device according to claim 1 or 3.

8. the battery switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions; The controller: When a check is performed for a stuck-off state of one of the switching elements connected to the second power source side by an anode of a parasitic diode included in the battery switch, making the inter-system switch conductive, making the backup switch conductive, and making the one switching element included in the battery switch conductive while keeping the other switching element included in the battery switch cut off; a check for the one switching element included in the battery switch being stuck off is performed based on a voltage across both ends of the one switching element included in the battery switch; The power supply control device according to any one of claims 1 to 4.

9. the battery switch includes a pair of switching elements connected such that the parasitic diodes of the pair are oriented in opposite directions; The controller: When a check is performed for a stuck-off state of one of the switching elements in which a cathode of a parasitic diode included in the battery switch is connected to the second power supply side, making the inter-system switch conductive, cutting off the backup switch, and making the one switching element included in the battery switch conductive while cutting off the other switching element included in the battery switch; a check for the one switching element included in the battery switch being stuck off is performed based on a voltage across both ends of the one switching element included in the battery switch; The power supply control device according to any one of claims 1 to 4.

Images