Power supply device and control method

Abstract

To provide a power supply device and an inspection method capable of inspecting whether or not backup by a second power supply is possible while suppressing degradation of the second power supply.SOLUTION: A power supply device comprises a first system, a second system, a connection part, a second system switch, and an inspection part. The first system supplies a power of a first power supply to a first load. The second system supplies a power of a second power supply to a second load. The connection part can connect and disconnect between the first system and the second system. The second system switch can connect the second power supply to the second system. The inspection part inspects whether or not power can be supplied from the second power supply to the second load. The inspection part, in a case where a voltage of the second power supply is not equal to a voltage of the first power supply, controls the first power supply so as to equalize the voltage of the second power supply to the voltage of the first power supply, makes the second system switch conductive, steps down or up the first power supply, and performs inspection.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The disclosed embodiments relate to a power supply device and a testing method. [Background technology]

[0002] A battery control device that uses a second power supply as a sub-battery as backup when an abnormality occurs in a first power supply that serves as a main battery is known (see, for example, Patent Document 1). Such a battery control device needs to check whether backup by the second power supply is possible, that is, whether power can be supplied from the second power supply to a load that is to be supplied with power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-156228 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when checking whether backup by the second power source is possible, there is a problem that if the second power source discharges a large amount, deterioration of the second power source progresses.

[0005] One aspect of the embodiment has been made in consideration of the above, and aims to provide a power supply device and an inspection method that can inspect whether backup by a second power source is possible while suppressing deterioration of the second power source. [Means for solving the problem]

[0006] A power supply device according to one aspect of the embodiment includes a first system, a second system, a connection unit, a second system switch, and an inspection unit. The first system supplies power from a first power source to a first load. The second system supplies power from a second power source to a second load. The connection unit is capable of connecting and disconnecting the first system and the second system. The second system switch is capable of connecting the second power source to the second system. The inspection unit inspects whether power can be supplied from the second power source to the second load. If the voltage of the second power source is not equal to the voltage of the first power source, the inspection unit controls the first power source so that the voltage of the second power source becomes equal to the voltage of the first power source, then turns on the second system switch, and performs the inspection by stepping down or stepping up the voltage of the first power source. [Effects of the Invention]

[0007] A power supply device and a testing method according to one aspect of the embodiment have an effect of being able to test whether backup by the second power supply is possible while suppressing deterioration of the second power supply. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing an example of the configuration of a power supply device according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. [Figure 3] FIG. 3 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. [Figure 5] FIG. 5 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. [Figure 6] FIG. 6 is an explanatory diagram showing an example of the operation of a power supply device according to a comparative example. [Figure 7] FIG. 7 is an explanatory diagram of the inspection method according to the embodiment. [Figure 8] FIG. 8 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. [Figure 9]FIG. 9 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. [Figure 10] FIG. 10 is an explanatory diagram of the inspection method according to the embodiment. [Figure 11] FIG. 11 is an explanatory diagram of the inspection method according to the embodiment. [Figure 12] FIG. 12 is an explanatory diagram of the inspection method according to the embodiment. [Figure 13] FIG. 13 is a flowchart illustrating an example of processing executed by the inspection unit according to the embodiment. [Figure 14] FIG. 14 is an explanatory diagram of an inspection method according to a modified example of the embodiment. [Figure 15] FIG. 15 is a flowchart illustrating an example of processing executed by an inspection unit according to a modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of a power supply device and a power supply control method will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below. The following description will be given using an example of a power supply device that is installed in a vehicle with an automatic driving function and supplies power to a load, but the power supply device according to the embodiment may also be installed in a vehicle that does not have an automatic driving function.

[0010] The power supply device according to the embodiment is installed in an electric vehicle, a hybrid vehicle, or an internal combustion engine vehicle. The power supply device according to the embodiment may be installed in any device that has a first power supply and a second power supply, and that performs fail-operation (FOP) by backing up the first power supply with the second power supply in the event of a power failure in the first power supply.

[0011] [1. Power supply configuration] Fig. 1 is an explanatory diagram showing an example of the configuration of a power supply device according to an embodiment. As shown in Fig. 1, the power supply device 1 according to the embodiment is connected to a first power source 10 and an automatic driving control device 100. Furthermore, the power supply device 1 is connected to a first FOP load 101, a second FOP load 102, a third FOP load 103, and a general load 104, which are examples of first loads, and to the first FOP load 101, the second FOP load 102, and the third FOP load 103, which are examples of second loads.

[0012] The power supply device 1 includes a first system 110 and a second system 120. The first system 110 supplies power from the first power source 10 via a first connection device 50 to a first FOP load 101, a second FOP load 102, a third FOP load 103, and a general load 104, which are examples of first loads.

[0013] The first connection device 50 includes switches 51, 52, 53, and 54. The switch 51 can connect and disconnect the first system 110 and the first FOP load 101. The switch 52 can connect and disconnect the first system 110 and the second FOP load 102. The switch 53 can connect and disconnect the first system 110 and the third FOP load 103. The switch 54 can connect and disconnect the first system 110 and the general load 104.

[0014] The second system 120 supplies power from a second power supply 20 (described later) to a first FOP load 101, a second FOP load 102, and a third FOP load 103, which are examples of second loads, via a second connection device 60. The second connection device 60 includes switches 61, 62, and 63. The switch 61 is capable of connecting and disconnecting the second system 120 and the first FOP load 101. The switch 62 is capable of connecting and disconnecting the second system 120 and the second FOP load 102. The switch 63 is capable of connecting and disconnecting the second system 120 and the third FOP load 103.

[0015] The first FOP load 101, the second FOP load 102, and the third FOP load 103 are loads for autonomous driving. For example, the first FOP load 101, the second FOP load 102, and the third FOP load 103 are a steering motor, an electric brake device, an in-vehicle camera, a radar, etc. that operate during autonomous driving. The general load 104 includes, for example, a display, an air conditioner, an audio device, a video device, various lights, etc.

[0016] The first FOP load 101, the second FOP load 102, the third FOP load 103, and the general load 104 operate using power supplied from the power supply device 1. The automatic driving control device 100 is a device that operates the first FOP load 101, the second FOP load 102, and the third FOP load 103 to control the automatic driving of a vehicle.

[0017] When the power supply device 1 is mounted on an engine vehicle, the first power source 10 includes a generator 11 and a lead battery (hereinafter referred to as "PbB12"). The battery of the first power source 10 may be any secondary battery other than PbB12.

[0018] The generator 11 is, for example, an alternator that generates electricity by converting the kinetic energy of a running vehicle into electricity. The generator 11 charges the PbB 12 and the second power source 20 with the generated power, and supplies power to the first FOP load 101, the second FOP load 102, the third FOP load 103, and the general load 104.

[0019] When the power supply device 1 is mounted on an electric vehicle or a hybrid vehicle, the first power source 10 includes a DC / DC converter (hereinafter referred to as "DC / DC") and a PbB 12. In this case, the DC / DC is connected to a generator and a high-voltage battery having a higher voltage than the PbB 12, and steps down the voltages of the generator and the high-voltage battery and outputs the voltage to the first system 110. The generator is, for example, an alternator. The high-voltage battery is, for example, a battery for driving the vehicle mounted on the electric vehicle or hybrid vehicle.

[0020] The power supply device 1 includes a second power supply 20, a connection unit 41, a second system switch 42, a DC / DC converter (hereinafter referred to as "DC / DC 43"), a control unit 3, a first voltage sensor 7, a second voltage sensor 70, and a current sensor 8. The second power supply 20 is a backup power supply in case the first power supply 10 is unable to supply power.

[0021] The second power source 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). The battery of the second power source 20 may be any secondary battery other than the LiB21. The second power source 20 also includes a temperature sensor, a voltage sensor, and a current sensor, all of which are not shown. The temperature sensor detects the temperature of the LiB21 and outputs the result to the control unit 3. The voltage sensor detects the voltage of the LiB21 and outputs the result to the control unit 3. The current sensor detects the current output from the LiB21 and the current input to the LiB21 and outputs the result to the control unit 3.

[0022] The connection unit 41 is provided on the inter-system line 130 that connects the first system 110 and the second system 120, and is a switch that can connect and disconnect the first system 110 and the second system 120. The second system switch 42 is a switch that can connect and disconnect the second power supply 20 to the second system 120. The DC / DC 43 is connected in parallel with the second system switch 42, and adjusts the voltage output from the LiB21 and the voltage input to the LiB21.

[0023] The first voltage sensor 7 is provided in the first system 110, detects the voltage of the first system 110, and outputs the detection result to the control unit 3. The second voltage sensor 70 is provided in the second system 120, detects the voltage of the second system 120, and outputs the detection result to the control unit 3.

[0024] Specifically, the second voltage sensor 70 includes voltage sensors 71, 72, and 73. The voltage sensor 71 detects the voltage applied from the second system 120 to the first FOP load 101 and outputs the detection result to the control unit 3. The voltage sensor 72 detects the voltage applied from the second system 120 to the second FOP load 102 and outputs the detection result to the control unit 3.

[0025] The voltage sensor 73 detects the voltage applied to the third FOP load 103 from the second system 120 and outputs the detection result to the control unit 3. The current sensor 8 detects the current flowing in the second system 120 and outputs the detection result to the control unit 3.

[0026] Note that a single voltage sensor may be provided instead of providing a voltage sensor for each of the first to third FOP loads 101 to 103. In this case, voltage sensor 70 may be provided between the point where second system 120 branches off to first to third FOP loads 101 to 103 and the connection point between second system 120 and inter-system line 130.

[0027] The control unit 3 includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and various other circuits. The control unit 3 may also be configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0028] The control unit 3 includes an inspection unit 31 that functions when the CPU executes a program stored in the ROM using the RAM as a work area, and controls the operation of the power supply device 1. When the power supply device 1 is in normal operation, the control unit 3 places the switches 51, 52, 53, 54, 61, 62, and 63 in a conductive state.

[0029] The control unit 3 detects a ground fault in the first system 110 or the second system 120 based on the detection results input from the first voltage sensor 7 and the second voltage sensor 70. A specific example of a method for detecting a ground fault by the control unit 3 will be described later.

[0030] When the control unit 3 detects a ground fault in the first system 110 or the second system 120, it notifies the automatic driving control device 100 of that fact. When the control unit 3 detects a ground fault in the first system 110 or the second system 120, it may also notify the automatic driving control device 100 that automatic driving is not possible. When the control unit 3 does not detect a ground fault in the first system 110 or the second system 120, it may also notify the automatic driving control device 100 that automatic driving is possible.

[0031] When a ground fault occurs in the first system 110, the control unit 3 cuts off the connection unit 41, turns on the second system switch 42, and supplies power from the second power source 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103.

[0032] When a ground fault occurs in the second system 120, the control unit 3 cuts off the connection unit 41 and supplies power from the first power source 10 to the first FOP load 101, the second FOP load 102, the third FOP load 103, and the general load 104 with the second system switch 42 cut off.

[0033] As a result, even if a ground fault occurs in one of the systems during automatic driving, the power supply device 1 can use the other system, and the automatic driving control device 100 can cause the vehicle to evacuate to a safe place and stop.

[0034] In this way, the control unit 3 performs backup using the second power supply 20 when the first power supply 10 is abnormal, but if, for example, the second system switch 42 is stuck off, backup cannot be performed normally.

[0035] For this reason, the control unit 3 needs to determine whether backup by the second power source 20 is possible (hereinafter, this may be referred to as "backup possibility determination"). A typical control unit will turn on the second system switch 42 and supply power from the second power source 20 to the second system 120, for example, immediately after the ignition switch (IG) is turned on or while the vehicle is stopped at a traffic light, and then determine whether backup is possible.

[0036] The control unit determines that backup is possible when power is normally supplied from the second power source 20 to the second system 120, and determines that backup is not possible when power is not supplied from the second power source 20 to the second system 120. However, when checking whether backup by the second power source 20 is possible, there is a problem that deterioration of the LiB 21 in the second power source 20 progresses if the discharge amount of the second power source 20 is large.

[0037] Therefore, the inspection unit 31 of the embodiment is equipped with an inspection unit 31 that inspects whether power can be supplied from the second power source 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103, which are examples of second loads, while suppressing deterioration of the second power source 20.

[0038] If the voltage of the first power source 10 is not equal to the voltage of the second power source 20, the inspection unit 31 controls the first power source 10 so that the voltage of the first power source 10 becomes equal to the voltage of the second power source 20, and then turns on the second system switch 42 to step down or step up the voltage of the first power source 10 to perform the inspection. At this time, the inspection unit 31 steps up or down the voltage of the first power source 10 by controlling the generator 11 of the first power source 10.

[0039] If the current sensor 8 detects the minimum necessary current being discharged from the second power source 20 immediately after the voltage of the first power source 10, which has become equal to the voltage of the second power source 20, is reduced, the inspection unit 31 determines that the second system switch 42 is not stuck off and that backup is possible.

[0040] Furthermore, if the current sensor 8 does not detect a current being discharged from the second power source 20 immediately after the voltage of the first power source 10, which has become equal to the voltage of the second power source 20, is lowered, the inspection unit 31 can determine that the second system switch 42 is stuck off and backup is not possible.

[0041] In this way, the inspection unit 31 discharges the minimum necessary current from the second power source 20 to inspect whether backup is possible, so that it is possible to inspect whether power can be supplied from the second power source 20 to the second system 120 while suppressing deterioration of the second power source 20.

[0042] Furthermore, if the current sensor 8 detects the minimum current required to charge the second power source 20 immediately after boosting the voltage of the first power source 10, which has become equal to the voltage of the second power source 20, the inspection unit 31 determines that the second system switch 42 is not stuck off and that backup is possible.

[0043] Furthermore, if the current sensor 8 does not detect a current charging the second power source 20 immediately after boosting the voltage of the first power source 10, which has become equal to the voltage of the second power source 20, the inspection unit 31 determines that the second system switch 42 is stuck off and that backup is not possible.

[0044] In this way, the inspection unit 31 charges the second power source 20 with the minimum necessary current and performs an inspection to determine whether backup is possible, so that it is possible to inspect whether power can be supplied from the second power source 20 to the second system 120 while suppressing deterioration of the second power source 20.

[0045] Furthermore, when the voltage of the first power source 10 is equal to the voltage of the second power source 20, the inspection unit 31 lowers or raises the voltage of the first power source 10 to inspect whether power can be supplied from the second power source 20 to the second system 120.

[0046] This allows the inspection unit 31 to perform an inspection to determine whether backup is possible by discharging the minimum necessary current from the second power source 20 or charging the second power source 20 with the minimum necessary current. Therefore, the inspection unit 31 can inspect whether power can be supplied from the second power source 20 to the second system 120 while suppressing deterioration of the second power source 20.

[0047] Although the generator 11 can boost the voltage of the first power source 10 to a voltage higher than the voltage of PbB12, it cannot lower the voltage of the first power source 10 to a voltage lower than the voltage of PbB12 even when the power generation operation is stopped.

[0048] Therefore, if the voltage of the first power source 10 and the voltage of the second power source 20 cannot be made equal, the inspection unit 31 cuts off the connection unit 41, turns on the second system switch 42, and inspects whether power can be supplied from the second power source 20 to the second system 120.

[0049] This allows the inspection unit 31 to inspect whether power can be supplied from the second power source 20 to the second system 120 even if the voltage of the first power source 10 and the voltage of the second power source cannot be made equal.

[0050] [2. Normal operation of the power supply] 2, the control unit 3 turns on all of the switches 51, 52, 53, and 54 of the first connection device 50 and all of the switches 61, 62, and 63 of the second connection device 60. Then, the control unit 3 turns on the connection unit 41 while keeping the second system switch 42 off, and supplies power from the first power supply 10 to the first FOP load 101, the second FOP load 102, the third FOP load 103, and the general load 104. At this time, the control unit 3 stops the operation of the DC / DC converter 43.

[0051] [3. Operation of power supply when a ground fault occurs] Next, the operation of the power supply device 1 when a ground fault occurs will be described with reference to Figures 3 to 5. As shown in Figure 3, in the power supply device 1, for example, when a ground fault 202 occurs in the first system 110, an overcurrent flows toward the ground fault point, and the voltage of the first system 110 detected by the first voltage sensor 7 becomes equal to or lower than the ground fault threshold value.

[0052] Furthermore, in the power supply device 1, when a ground fault 201 occurs in the second system 120 (for example, the second system 120 connected to the third FOP load 103), an overcurrent flows toward the ground fault point. As a result, the voltage of the second system 120 detected by the second voltage sensor 70 becomes equal to or lower than the ground fault threshold value.

[0053] Therefore, when the voltage detected by at least one of the first voltage sensor 7 and the second voltage sensor 70 becomes equal to or lower than the ground fault threshold, the control unit 3 detects an abnormality in the power supply, cuts off the connection unit 41, and turns on the second system switch 42 to enter a pre-cutoff state. At this time, the control unit 3 provisionally determines that a ground fault has occurred in the first system 110 or the second system 120.

[0054] Thereafter, after provisionally determining that a ground fault has occurred in the first system 110 or the second system 120, if the voltage detected by the second voltage sensor 70 is below the ground fault threshold and the voltage detected by the first voltage sensor 70 returns to exceeding the ground fault threshold within a predetermined time, the control unit 3 makes a definitive determination that a ground fault 201 has occurred in the second system 120.

[0055] 4, the control unit 3 shuts off the second system switch 42 and shuts off all of the switches 61, 62, and 63 of the second connection device 60 to enter a fully shut-off state. The control unit 3 then supplies power from the first power source 10 to the first FOP load 101, the second FOP load 102, the third FOP load 103, and the general load 104, and notifies the automatic driving control device 100 of this fact.

[0056] As a result, the automatic driving control device 100 can operate the first FOP load 101, the second FOP load 102, the third FOP load 103, and the general load 104 using power supplied from the first power source 10, and can evacuate the vehicle to a safe location and stop it.

[0057] Furthermore, after provisionally determining that a ground fault has occurred in the first system 110 or the second system 120, if the voltage detected by the first voltage sensor 7 remains below the ground fault threshold for a predetermined period of time or more and the voltage detected by the second voltage sensor 70 returns to exceeding the ground fault threshold within the predetermined period of time, the control unit 3 finally determines that a ground fault 202 has occurred in the first system 110.

[0058] 5, the control unit 3 turns off all of the switches 51, 52, 53, and 54 of the first connection device 50 to a main shutoff state, and supplies power from the second power source 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103. The control unit 3 then notifies the automatic driving control device 100 of this fact.

[0059] As a result, the automatic driving control device 100 can operate the first FOP load 101, the second FOP load 102, and the third FOP load 103 using power supplied from the second power source 20, and can evacuate the vehicle to a safe location and stop it.

[0060] In addition, in the power supply device 1, if the first FOP load 101, the second FOP load 102, the third FOP load 103, or the general load 104 temporarily becomes overloaded, rather than due to a ground fault 201, 202, the voltage detected by the first voltage sensor 7 and the second voltage sensor 70 may temporarily fall below the ground fault threshold.

[0061] In this case, the power supply device 1 cuts off the connection part 41, turns on the second system switch 42 to put it in a temporary cut-off state, and continuously supplies power from the first power source 10 and the second power source 20 to the first FOP load 101, the second FOP load 102, the third FOP load 103, and the general load 104.

[0062] After provisionally determining that a ground fault has occurred in first system 110 or second system 120, if the voltages detected by first voltage sensor 7 and second voltage sensor 70 both return to exceeding the ground fault threshold before a predetermined time has elapsed, control unit 3 officially determines that there is no abnormality in the power supply. Thereafter, control unit 3 turns off second system switch 42 and re-establishes conduction in connection unit 41 to return to normal operation shown in FIG. 2 .

[0063] [4. Inspection of the second system for comparison] Furthermore, the power supply device 1 checks the operation of the second system 120 at a timing that does not interfere with automatic driving, such as when starting up or stopping the vehicle. Here, for example, as shown in Fig. 6, as a comparative method for inspecting the second system 120, there is a method in which the connection part 41 is shut off during normal operation and the inspection is performed.

[0064] In the inspection method according to the comparative example, if the current sensor 8 detects a current after the connection part 41 is cut off, it can be determined that power is being supplied from the second power source 20 to the second system 120 and therefore normal. Also, in the inspection method according to the comparative example, if the current sensor 8 does not detect a current after the connection part 41 is cut off, it can be determined that power is not being supplied from the second power source 20 to the second system 120 and therefore abnormal.

[0065] However, in the inspection method according to the comparative example, a current corresponding to the voltage of the second power source 20 flows as the inspection current, which inevitably results in a large amount of discharge. If the second power source 20 discharges a large amount, deterioration of the second power source 20 progresses. Therefore, in the inspection method according to the embodiment, whether backup by the second power source 20 is possible is inspected while suppressing deterioration of the second power source 20.

[0066] [5. Inspection of the second system according to the embodiment] 7, the inspection unit 31 according to the embodiment first detects the voltages of the first power source 10 and the second power source 20 at a timing that does not impede automatic driving, such as when starting or stopping the vehicle. At this time, the voltage of the first power source 10 is 16 (V) when the voltage of the generator 11 is 16 (V) and the voltage of the PbB 12 is 13 (V). Furthermore, the voltage of the second power source 20 is 16 (V) when the voltage of the LiB 21 is 16 (V).

[0067] When the voltage of the first power supply 10 and the voltage of the second power supply 20 are equal, the inspection unit 16 turns on the second system switch 42, controls the generator 11, and adjusts the voltage by increasing or decreasing the voltage of the first power supply 10. Thereafter, an inspection is performed to determine whether or not power can be supplied from the second power supply 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103.

[0068] 8, for example, when the inspection unit 31 steps down the voltage of the first power supply 10 while the second system switch 42 is in a conductive state, the voltage of the first power supply 10 gradually becomes lower than the voltage of the second power supply 20. That is, the differential voltage between the first power supply 10 and the second power supply 20 gradually increases from 0, and a current corresponding to this differential voltage flows from the second power supply 20 to the second system 120. This current gradually increases from 0 according to the differential voltage.

[0069] Therefore, the inspection unit 31 can detect the minute current that starts to flow from the second power source 20 to the second system 120 as a current for checking continuity using the current sensor 8. Note that once the continuity check is completed, the inspection unit 31 stops stepping down the voltage of the first power source 10.

[0070] Therefore, if the current sensor 8 detects the minimum necessary current being discharged from the second power source 20 immediately after the voltage of the first power source 10, which has become equal to the voltage of the second power source 20, is reduced, the inspection unit 31 determines that the second system switch 42 is not stuck off and that backup is possible.

[0071] Furthermore, if the current sensor 8 does not detect a current being discharged from the second power source 20 immediately after the voltage of the first power source 10, which has become equal to the voltage of the second power source 20, is reduced, the inspection unit 31 determines that the second system switch 42 is stuck off and that backup is not possible.

[0072] In this way, the inspection unit 31 discharges the minimum necessary current from the second power source 20 to inspect whether backup is possible, so that it is possible to inspect whether power can be supplied from the second power source 20 to the second system 120 while suppressing deterioration of the second power source 20.

[0073] Furthermore, for example, when the inspection unit 31 boosts the voltage of the first power supply 10 with the second system switch 42 in a conductive state, the voltage of the first power supply 10 gradually becomes higher than the voltage of the second power supply 20. That is, the differential voltage between the first power supply 10 and the second power supply 20 gradually increases from 0, and a current according to this differential voltage flows from the first power supply 10 to the second power supply 20 as a charging current. This current gradually increases from 0 according to the differential voltage.

[0074] 9, the inspection unit 31 can detect the minute current that starts to flow from the first power source 10 to the second power source 20 as a charging current for the continuity check using the current sensor 8. Once the continuity check is completed, the inspection unit 31 stops boosting the voltage of the first power source 10.

[0075] Therefore, if the current sensor 8 detects the minimum necessary charging current flowing from the first power source 10 to the second power source 20 immediately after boosting the voltage of the first power source 10, the inspection unit 31 determines that the second system switch 42 is not stuck off and that backup is possible.

[0076] Furthermore, if the current sensor 8 does not detect a current flowing from the first power source 10 to the second power source 20 immediately after boosting the voltage of the first power source 10, the inspection unit 31 determines that the second system switch 42 is stuck off and that backup is not possible.

[0077] In this way, the inspection unit 31 charges the second power source 20 with the minimum necessary current and performs an inspection to determine whether backup is possible, so that it is possible to inspect whether power can be supplied from the second power source 20 to the second system 120 while suppressing deterioration of the second power source 20.

[0078] 10 , when the voltages are detected, the voltage of the first power source 10 and the voltage of the second power source 20 may not be equal. For example, if the voltage of the first power source 10 is lower than the voltage of the second power source 20, the inspection unit 31 increases the voltage of the first power source 10 while keeping the second system switch 42 turned off, thereby adjusting the voltage so that the voltage of the first power source 10 and the voltage of the second power source 20 become equal.

[0079] Then, the inspection unit 31 turns on the second system switch 42, lowers the voltage of the first power source 10, and inspects whether power can be supplied from the second power source 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103.

[0080] This allows the inspection unit 31 to create the same state as that shown in Figure 8, so that it can discharge the minimum necessary current from the second power source 20, thereby suppressing deterioration of the second power source 20, and inspect whether or not power can be supplied from the second power source 20 to the second system 120.

[0081] The inspection unit 31 may adjust the voltage so that the voltage of the first power source 10 and the voltage of the second power source 20 are equal, and then turn on the second system switch 42, boost the voltage of the first power source 10, and inspect whether or not power can be supplied from the second power source 20 to the second system 120.

[0082] This allows the inspection unit 31 to create the same state as that shown in Figure 9, so that the second power source 20 can be charged with the minimum necessary charging current, thereby suppressing deterioration of the second power source 20 and inspecting whether or not power can be supplied from the second power source 20 to the second system 120.

[0083] 11, when the voltage is detected, the voltage of the first power source 10 may be higher than the voltage of the second power source. In this case, if the voltage of the LiB 21 is higher than the voltage of the PbB 12, the inspection unit 31 reduces the voltage of the generator 11 and adjusts the voltage so that the voltage of the first power source 10 and the voltage of the LiB 21 are equal.

[0084] Thereafter, the inspection unit 31 turns on the second system switch 42, drops the voltage of the first power supply 10, and inspects whether or not power can be supplied from the second power supply 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103. At this time, the inspection unit 31 may turn on the second system switch 42, raise the voltage of the first power supply 10, and inspect whether or not power can be supplied from the second power supply 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103.

[0085] 12, when the voltage is detected, the voltage of LiB 21 may be lower than the voltage of PbB 12. In this case, even if the inspection unit 31 controls the generator 11, it is not possible to reduce the voltage of the first power source 10 to the voltage of the second power source 20.

[0086] Therefore, when the voltage of LiB21 is lower than the voltage of PbB12, the inspection unit 31 turns off the connection unit 41 and then turns on the second system switch 42, similar to the inspection method according to the comparative example shown in Fig. 6. Then, the inspection unit 31 inspects whether or not power can be supplied from the second power source 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103.

[0087] [6. Processing performed by the inspection department] Next, the processing executed by the inspection unit 31 will be described with reference to Fig. 13. Fig. 13 is a flowchart showing an example of the processing executed by the inspection unit 13 according to the embodiment. The inspection unit 31 starts the processing shown in Fig. 13 at a timing when there is no interference with the autonomous driving, such as when starting or stopping the vehicle. At this time, the connection unit 41 is conductive and the second system switch 42 is cut off.

[0088] As shown in FIG. 13, when the timing for inspection arrives, the inspection unit 31 first detects the voltages of the first power source 10 and the second power source 20 (step S101), and determines whether the voltage of the first power source 10 and the voltage of the second power source 20 are equal to each other (step S102).

[0089] If the inspection unit 31 determines that the voltage of the first power source 10 and the voltage of the second power source 20 are equal (step S102, Yes), it turns on the second system switch 42 (step S103) and instructs the generator 11 to step down (step S104).

[0090] Then, the inspection unit 31 determines whether backup power can be supplied from the second power source 20 to the second system 120 (step S105). At this time, if a current is detected by the current sensor 8, the inspection unit 31 determines that backup power can be supplied. If a current is not detected by the current sensor 8, the inspection unit 31 determines that backup power cannot be supplied. Thereafter, the inspection unit 31 cancels the instruction to the generator 11 to stop the generator 11 (step S106), turns off the second system switch 42 (step S107), and ends the process.

[0091] Furthermore, if the inspection unit 31 determines in step S102 that the voltage of the first power source 10 and the voltage of the second power source 20 are not equal (step S102, No), it determines whether the voltage of the first power source 10 is lower than the voltage of the second power source 20 (step S108).

[0092] If the inspection unit 31 determines that the voltage of the first power source 10 is lower than the voltage of the second power source 20 (step S108, Yes), it instructs the generator 11 to increase the voltage (step S109) and proceeds to step S111. If the inspection unit 31 determines that the voltage of the first power source 10 is higher than the voltage of the second power source 20 (step S108, No), it instructs the generator 11 to decrease the voltage (step S110) and proceeds to step S111.

[0093] In step S111, the inspection unit 31 determines whether or not the voltage of the first power source 10 has been equalized to the voltage of the second power source 20. If the inspection unit 31 determines that the voltage of the first power source 10 has been equalized to the voltage of the second power source 20 (Yes in step S111), the processing proceeds to step S103.

[0094] Furthermore, if the inspection unit 31 determines that the voltage of the first power source 10 cannot be made equal to the voltage of the second power source 20 (No in step S111), it shuts off the connection unit 41 (step S112), shuts off the second system switch 42 (step S113), and proceeds to step S105. Note that the above-described embodiment is merely an example, and various modifications are possible. Below, an example of an inspection method according to a modification of the embodiment and a process executed by the inspection unit 31 will be described.

[0095] [7. Inspection of the second system according to the modified embodiment] The inspection unit 31 according to the modified example controls the first power supply 10 so that the voltage of the first power supply 10 is equal to the voltage of the second power supply 20, and when the voltage difference between the first power supply 10 and the second power supply 20 falls within a predetermined voltage difference, turns on the second system switch 42. Then, the inspection unit 31 inspects whether or not power can be supplied from the second power supply 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103.

[0096] For example, as shown in FIG. 14, when the inspection unit 31 detects the voltage, if the voltage of the first power source 10 is lower than the voltage of the second power source 20, the inspection unit 31 instructs the generator 11 to increase the voltage so that the voltage of the first power source 10 becomes equal to the voltage of the second power source 20.

[0097] Then, when the voltage difference between the first power source 10 and the second power source 20 falls within a predetermined voltage difference before the voltage of the first power source 10 becomes equal to the voltage of the second power source 20, the inspection unit 31 terminates the voltage boost by the generator 11. At this time, the voltage of the first power source 10 is lower than the voltage of the second power source 20 by the predetermined voltage difference.

[0098] Therefore, by turning on the second system switch 42 in this state, the inspection unit 31 can discharge a small amount of current from the second power supply 20 to the second system 120. Then, depending on whether or not a current is detected by the current sensor 8, the inspection unit 31 can inspect whether or not power can be supplied from the second power supply 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103.

[0099] As a result, the inspection unit 31 can inspect whether or not power can be supplied from the second power source 20 to the second system 120 without first boosting the voltage of the first power source 10 until it becomes equal to the voltage of the second power source 20 and then lowering the voltage of the first power source 10.

[0100] If the voltage of the first power source 10 is higher than the voltage of the second power source 20, the inspection unit 31 instructs the generator 11 to step down the voltage so that the voltage of the first power source 10 becomes equal to the voltage of the second power source 20. The inspection unit 31 then stops the step-down operation by the generator 11 when the voltage difference between the first power source 10 and the second power source 20 becomes within a predetermined voltage difference before the voltage of the first power source 10 becomes equal to the voltage of the second power source 20. At this time, the voltage of the first power source 10 is higher than the voltage of the second power source 20 by the predetermined voltage difference. Therefore, the inspection unit 31 can charge the second power source 20 with a small current by turning on the second system switch 42 in this state. The inspection unit 31 can then inspect whether power can be supplied from the second power source 20 to the first FOP load 101, the second FOP load 102, and the third FOP load 103, depending on whether a current is detected by the current sensor 8.

[0101] 8. Processing Executed by the Inspection Unit According to Modification of the Embodiment Next, processing executed by the inspection unit 31 according to the modified example will be described with reference to Fig. 15. Fig. 15 is a flowchart showing an example of processing executed by the inspection unit 13 according to the modified example of the embodiment.

[0102] As shown in FIG. 15, when the timing for inspection arrives, the inspection unit 31 first detects the voltages of the first power source 10 and the second power source 20 (step S201), and determines whether the voltage of the first power source 10 and the voltage of the second power source 20 are equal to each other (step S202).

[0103] If the inspection unit 31 determines that the voltage of the first power source 10 and the voltage of the second power source 20 are equal (Yes in step S202), it turns on the second system switch 42 (step S203) and instructs the generator 11 to step down (step S204).

[0104] Then, the inspection unit 31 determines whether backup power can be supplied from the second power source 20 to the second system 120 (step S205). After that, the inspection unit 31 cancels the instruction to the generator 11 to stop the generator 11 (step S206), turns off the second system switch 42 (step S207), and ends the processing. The processing from steps S201 to S207 up to this point is the same as the processing from steps S101 to S107 shown in FIG. 13.

[0105] In the modified example, if the inspection unit 31 determines in step S202 that the voltage of the first power source 10 is not equal to the voltage of the second power source 20 (step S202, No), it determines whether the voltage of the first power source 10 is lower than the voltage of the second power source 20 (step S208).

[0106] If the inspection unit 31 determines that the voltage of the first power source 10 is not lower than the voltage of the second power source 20 (step S208, No), it instructs the generator 11 to step down (step S209) and determines whether the voltage difference between the first power source 10 and the second power source 20 has become equal to or less than a predetermined voltage difference (step S210).

[0107] If the inspection unit 31 determines that the voltage difference between the first power source 10 and the second power source 20 is equal to or less than the predetermined voltage difference (Yes in step S210), it turns on the second system switch 42 (step S215) and moves the process to step S205. If the inspection unit 31 determines that the voltage difference between the first power source 10 and the second power source 20 is not equal to or less than the predetermined voltage difference (No in step S210), it determines whether a certain time has elapsed since the voltage step-down instruction was issued in step S209 (step S211).

[0108] If the inspection unit 31 determines that the certain time has not elapsed (step S211, No), it returns the process to step S209. If the inspection unit 31 determines that the certain time has elapsed (step S211, Yes), it determines that the voltage of PbB 12 is higher than the voltage of LiB 21 by a certain voltage difference or more and that the voltage of first power supply 10 cannot be lowered any further, disconnects connection unit 41 (step S212), and moves the process to step S205.

[0109] Furthermore, if the inspection unit 31 determines that the voltage of the first power source 10 is lower than the voltage of the second power source 20 (Yes in step S208), it instructs the generator 11 to increase the voltage (step S213). Then, the inspection unit 31 determines whether the voltage difference between the first power source 10 and the second power source 20 is equal to or less than a predetermined voltage difference (step S214).

[0110] If the inspection unit 31 determines that the voltage difference between the first power source 10 and the second power source 20 is equal to or less than the predetermined voltage difference (Yes in step S214), the processing proceeds to step S215. If the inspection unit 31 determines that the voltage difference between the first power source 10 and the second power source 20 is not equal to or less than the predetermined voltage difference (No in step S214), the processing proceeds to step S213.

[0111] Further advantages and modifications will readily occur to those skilled in the art. Therefore, 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 their equivalents. [Explanation of symbols]

[0112] 1 Power supply 10 1st power supply 11. Generator 12 PbB 20 2nd power supply 21 LiB 3. Control Unit 31 Inspection Department 41 Connection 42 Second system switch 43 DC / DC 50 First connection device 60 Second connection device 51~54,61~63 Switches 7. First voltage sensor 70 Second voltage sensor 71~73 Voltage sensor 8 Current Sensor 100 Automatic driving control device 101 1st FOP load 102 2nd FOP load 103 3rd FOP load 104 General load 110 1st system 120 2nd system 130 Intersystem Line

Claims

1. a first system that supplies power from a first power source to a first load; a second system that supplies power from a second power source including a secondary battery to a second load; a connection part that can connect and disconnect the first system and the second system; a second system switch capable of connecting the second power supply to the second system; a control unit that checks whether power can be supplied from the second power source to the second load; a first voltage sensor that detects a first voltage of the first system and outputs the detected first voltage to the control unit; a second voltage sensor that detects a second voltage of the secondary battery and outputs the detected voltage to the control unit; a current sensor that detects a current flowing through the second system and outputs the detected current to the control unit; Equipped with The control unit If the second voltage is not equal to the first voltage, the first power supply is controlled so that the first voltage becomes equal to the second voltage, and then the second system switch is turned on to step down the voltage of the first power supply. Thereafter, when the current sensor detects a current, the test is performed to determine that power can be supplied from the second power supply to the second load. power supply.

2. The control unit When the first voltage is equal to the second voltage, the second system switch is turned on, and the first power supply is lowered to perform the inspection. The power supply device of claim 1 .

3. The control unit If the first voltage and the second voltage cannot be made equal even when the first power supply is controlled so that the first voltage is equal to the second voltage, the connection part is cut off and the second system switch is made conductive to perform the inspection. The power supply device according to claim 1 or 2.

4. a first system that supplies power from a first power source to a first load; a second system that supplies power from a second power source including a secondary battery to a second load; a connection part that can connect and disconnect the first system and the second system; a second system switch capable of connecting the second power supply to the second system; a control unit that checks whether power can be supplied from the second power source to the second load; a first voltage sensor that detects a first voltage of the first system and outputs the detected first voltage to the control unit; a second voltage sensor that detects a second voltage of the secondary battery and outputs the detected voltage to the control unit; a current sensor that detects a current flowing through the second system and outputs the detected current to the control unit; Equipped with The control unit When the first voltage is lower than the second voltage, the first power supply is controlled so that the first voltage becomes equal to the second voltage, and when a difference between the first voltage and the second voltage becomes within a threshold before the first voltage and the second voltage become equal, the second system switch is turned on, and thereafter, when the current sensor detects a current, the inspection is performed to determine that power can be supplied from the second power supply to the second load. power supply.

5. a first system that supplies power from a first power source to a first load; a second system that supplies power from a second power source including a secondary battery to a second load; a connection part that can connect and disconnect the first system and the second system; a second system switch capable of connecting the second power supply to the second system; a first voltage sensor that detects a first voltage of the first system; a second voltage sensor for detecting a second voltage of the secondary battery; a current sensor for detecting a current flowing through the second system; A control method for controlling a power supply device using a control device, If the second voltage detected by the second voltage sensor is not equal to the first voltage detected by the first voltage sensor, the first power supply is controlled so that the first voltage becomes equal to the second voltage, and then the second system switch is turned on to step down the voltage of the first power supply. Thereafter, when the current sensor detects a current, a test is performed to determine that power can be supplied from the second power supply to the second load. Control method.

6. a first system that supplies power from a first power source to a first load; a second system that supplies power from a second power source including a secondary battery to a second load; a connection part that can connect and disconnect the first system and the second system; a second system switch capable of connecting the second power supply to the second system; a first voltage sensor that detects a first voltage of the first system; a second voltage sensor for detecting a second voltage of the secondary battery; a current sensor for detecting a current flowing through the second system; A control method for controlling a power supply device using a control device, When the first voltage detected by the first voltage sensor is lower than the second voltage detected by the second voltage sensor, the first power supply is controlled so that the first voltage becomes equal to the second voltage, and when a difference between the first voltage and the second voltage becomes within a threshold value before the first voltage and the second voltage become equal, the second system switch is turned on, and thereafter, when the current sensor detects a current, a test is performed to determine that power can be supplied from the second power supply to the second load. Control method.

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