Power supply device and control method

Abstract

To provide a power source device capable of accurately determining whether or not backup can be performed by a second power source even in cold districts, and a determination method.SOLUTION: A power source device comprises a storage section and a determination section. The storage section stores: first characteristic information to be used for determining whether or not backup can be performed in a case where a cell resistance value of a second power source, which performs the backup when a first power source is abnormal, is a first cell resistance value; and second characteristic information to be used for determining whether or not the backup can be performed in a case where the cell resistance value of the second power source is a second resistance value which is smaller than the first cell resistance value. The determination section performs the backup possibility determination based on the second characteristic information in a case where cell resistance of the second power source is less than second cell resistance and performs the backup possibility determination based on the first characteristic information in a case where the cell resistance of the second power source is equal to or more than the second cell resistance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] As a redundant power supply system, if an abnormality occurs in the primary power supply during automatic operation, the secondary power supply must supply power and perform fail-over (FOP). Therefore, for safety reasons, it is desirable to determine in advance whether backup by the secondary power supply is possible.

[0003] As a method for determining whether backup is possible, there is a method for determining whether the power determined by the SOC (State Of Charge) and temperature of the battery of the second power source is more than the required power (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-156228 Summary of the Invention [Problem to be solved by the invention]

[0005] However, for example, even though battery deterioration is less likely to progress in cold regions than in warm regions, the same criteria are used to determine whether backup is possible regardless of the region, so it may be erroneously determined that backup is not possible even if the battery is not deteriorated.

[0006] One aspect of the embodiment has been made in consideration of the above, and aims to provide a power supply device and a determination method that can accurately determine whether backup by a second power source is possible even in cold regions. [Means for solving the problem]

[0007] According to one embodiment, a power supply device includes a storage unit and a determination unit. The storage unit stores first characteristic information used to determine whether backup is possible when a cell resistance value of a second power source that backs up a first power source when an abnormality occurs is a first cell resistance value, and second characteristic information used to determine whether backup is possible when the cell resistance value of the second power source is a second cell resistance value that is smaller than the first cell resistance value. The determination unit determines whether backup is possible based on the second characteristic information when the cell resistance value of the second power source is less than the second cell resistance value, and determines whether backup is possible based on the first characteristic information when the cell resistance value of the second power source is equal to or greater than the second cell resistance value. [Effects of the Invention]

[0008] A power supply device and a determination method according to an aspect of the embodiment provide an advantage in that it is possible to accurately determine whether or not backup by a second power source is possible, even in cold regions. [Brief explanation of the drawings]

[0009] [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 the power supply device according to the embodiment. [Figure 7] FIG. 7 is an explanatory diagram illustrating an example of application periods of the first characteristic information and the second characteristic information according to the embodiment. [Figure 8]FIG. 8 is an explanatory diagram of the first characteristic information according to the embodiment. [Figure 9] FIG. 9 is an explanatory diagram of the second characteristic information according to the embodiment. [Figure 10] FIG. 10 is a flowchart illustrating an example of processing executed by the determining unit according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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.

[0011] In addition, although the following description will be given of a case where the vehicle equipped with the power supply device is an electric vehicle or a hybrid vehicle, the vehicle equipped with the power supply device may also be an engine vehicle that runs on an internal combustion engine.

[0012] The power supply device according to the embodiment may be installed in any device that includes a first power supply and a second power supply and that backs up the first power supply with the second power supply in the event of a power failure in the first power supply.

[0013] [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, a first load 101, a general load 102, a second load 103, and an automatic driving control device 100. The power supply device 1 includes a first system 110 that supplies power from the first power source 10 to the first load 101 and the general load 102, and a second system 120 that supplies power from a second power source 20 (described later) to the second load 103.

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

[0015] The second load 103 has the same functions as the first load 101. The second load 103 includes devices that operate during autonomous driving, such as a steering motor, an electric brake device, an on-board camera, and a radar. The first load 101, the general load 102, and the second load 103 operate using power supplied from the power supply device 1. The autonomous driving control device 100 is a device that operates the first load 101 or the second load 103 to control the autonomous driving of a vehicle.

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

[0017] The DC / DC converter 11 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 stepped-down voltage to the first system 110. The generator is, for example, an alternator that converts the kinetic energy of a running vehicle into electricity to generate power. The high-voltage battery is, for example, a battery for driving the vehicle that is installed in an electric vehicle or a hybrid vehicle.

[0018] When the first power supply 10 is installed in an engine vehicle, an alternator (generator) is provided instead of the DC / DC 11. The DC / DC 11 charges the PbB 12, supplies power to the first load 101 and the general load 102, supplies power to the second load 103, and charges the second power supply 20, which will be described later.

[0019] The power supply device 1 includes a second power supply 20, an inter-system switch 41, a battery switch 42, a bypass switch 43, a control unit 3, a first voltage sensor 51, a second voltage sensor 52, a DC / DC converter 53, and a memory unit 6. The second power supply 20 is a backup power supply in case the first power supply 10 is unable to supply power.

[0020] The second power source 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). Note that the battery of the second power source 20 may be any secondary battery other than the LiB21. The second power source 20 also includes a temperature sensor that detects the temperature of the LiB21 and outputs the result to the control unit 3, a voltage sensor that detects the voltage of the LiB21 and outputs the result to the control unit 3, and a current sensor that detects the current output from and input to the LiB21 and outputs the result to the control unit 3.

[0021] The inter-system switch 41 is provided on the inter-system line 130 connecting 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 battery switch 42 is a switch that can connect and disconnect the LiB 21 to the second system 120, and specifically, the battery switch 42 is a switch that can connect and disconnect the LiB 21 to the bypass switch 43 and the DC / DC 53.

[0022] The bypass switch 43 is a switch that can connect and disconnect the battery switch 42 and the second system 120. The DC / DC 53 is connected in parallel with the bypass switch 43, and adjusts the voltage output from the LiB21 and the voltage input to the LiB21.

[0023] The first voltage sensor 51 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 52 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] 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).

[0025] The control unit 3 controls the operation of the power supply device 1 by causing the CPU to execute a program stored in the ROM using the RAM as a work area. 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 51 and the second voltage sensor 52. A specific example of a method for detecting a ground fault by the control unit 3 will be described later.

[0026] 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.

[0027] When a power supply failure such as a ground fault occurs in the first system 110, the control unit 3 cuts off the inter-system switch 41, turns on the battery switch 42 and the bypass switch 43, and supplies power from the second power supply 20 to the second load 103. When a power supply failure such as a ground fault occurs in the second system 120, the control unit 3 cuts off the inter-system switch 41 and supplies power from the first power supply 10 to the first load 101 and the general load 102 with the battery switch 42 cut off.

[0028] 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.

[0029] In this way, the control unit 3 performs backup using the second power source 20 when the first power source 10 is abnormal, but if, for example, the performance of the LiB 21 of the second power source 20 deteriorates, the backup cannot be performed normally.

[0030] For this reason, the control unit 3 includes a determination unit 31 that determines whether or not backup by the second power source 20 is possible (hereinafter, may be referred to as "backup possibility determination"). The determination unit 31 determines whether or not backup is possible based on the temperature of the LiB 21 acquired from the second power source 20 via the line 22 and the SOC (State Of Charge) of the LiB 21 calculated based on the voltage of the LiB 21 and the input / output current.

[0031] Here, one method for determining whether backup is possible is to determine whether the power of the second power source 20, which is determined by the SOC and temperature of the battery of the second power source 20, is equal to or greater than the required power. On the other hand, it is known that the LiB 21 deteriorates more slowly in a relatively low temperature environment than in a high temperature environment.

[0032] Therefore, when determining whether backup is possible based on the SOC and temperature of LiB21, if the determination is based on criteria that assume a relatively warm region with high temperatures, there is a risk that in cold regions, it will be erroneously determined that backup is not possible even though backup is possible.

[0033] Therefore, the power supply device 1 is provided with a memory unit 6 that stores first characteristic information 61 assuming a warm region where the second power source 20 is likely to deteriorate, and second characteristic information 62 assuming a cold region where the second power source 20 is unlikely to deteriorate.

[0034] The first characteristic information 61 is information used to determine whether backup is possible when the cell resistance value of the second power supply 20 is a first cell resistance value. The second characteristic information 62 is information used to determine whether backup is possible when the cell resistance value of the second power supply 20 is a second resistance value smaller than the first cell resistance value.

[0035] The first resistance value is, for example, the cell resistance value when the LiB21 reaches EOL (End Of Life: battery life) (hereinafter, may be referred to as "EOL cell resistance value"). The second resistance value is, for example, a cell resistance value that is an intermediate value (hereinafter, may be referred to as "intermediate cell resistance value") between the cell resistance value when the LiB21 is BOL (Beginning Of Life: brand new) (hereinafter, may be referred to as "BOL cell resistance value") and the cell resistance value when the LiB21 reaches EOL. Note that the first resistance value and the second resistance value are not limited to these, and may be values ​​other than the above-exemplified cell resistance values ​​as long as the first resistance value is higher than the second resistance value.

[0036] Then, if the cell resistance value of the second power source 20 is less than the second cell resistance value, the judgment unit 31 judges whether backup is possible based on the second characteristic information, and if the cell resistance value of the second power source 20 is equal to or greater than the second cell resistance value, the judgment unit 31 judges whether backup is possible based on the first characteristic information.

[0037] As a result, the power supply device 1 can accurately determine whether backup is possible for the second power source 20, for example, in a cold region where deterioration has not progressed and the cell resistance value is equal to or greater than the BOL cell resistance value and less than the intermediate resistance value, by making a judgment based on the second characteristic information.

[0038] Furthermore, the power supply device 1 can accurately determine whether backup is possible for the second power source 20 whose cell resistance value has reached or exceeded the intermediate resistance value due to deterioration, regardless of whether the region is cold or temperate, by making a determination based on the first characteristic information.

[0039] [2. Normal operation of the power supply] Under normal circumstances when no ground fault has occurred in the first system 110 or the second system 120, the control unit 3 turns off the battery switch 42, turns on the inter-system switch 41 while keeping the bypass switch 43 conductive, and supplies power from the first power source 10 to the first load 101, the general load 102, and the second load 103, as shown in FIG. 2 .

[0040] [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 200 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 51 becomes equal to or lower than the ground fault threshold value.

[0041] Furthermore, in the power supply device 1, when a ground fault 201 occurs in the second system 120, an overcurrent flows toward the ground fault point, and the voltage of the second system 120 detected by the second voltage sensor 52 becomes equal to or lower than the ground fault threshold value.

[0042] Therefore, when the voltage detected by at least one of the first voltage sensor 51 and the second voltage sensor 52 becomes equal to or lower than the ground fault threshold, the control unit 3 detects an abnormality in the power supply, turns off the inter-system switch 41, and turns on the battery switch 42. 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.

[0043] Thereafter, if the voltage detected by the first voltage sensor 51 remains below the ground fault threshold for a predetermined period of time or more and the voltage detected by the second voltage sensor 52 returns to exceeding the ground fault threshold within the predetermined period of time, the control unit 3 determines that a ground fault 200 has occurred in the first system 110.

[0044] 4, the control unit 3 supplies power from the second power source 20 to the second load 103 and notifies the automatic driving control device 100 of this fact. As a result, the automatic driving control device 100 operates the second load 103 using the power supplied from the second power source 20, and causes the vehicle to evacuate to a safe place and stop.

[0045] In addition, after the control unit 3 has provisionally determined 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 52 is below the ground fault threshold and the voltage detected by the first voltage sensor 51 returns to exceeding the ground fault threshold within a predetermined time, the control unit 3 finally determines that a ground fault 201 has occurred in the second system 120.

[0046] 5, the control unit 3 then shuts off the battery switch 42, supplies power from the first power source 10 to the first load 101, and notifies the automatic driving control device 100 of this fact. As a result, the automatic driving control device 100 operates the first load 101 using the power supplied from the first power source 10, and causes the vehicle to retreat to a safe place and stop.

[0047] Furthermore, in the power supply device 1, when the first load 101 or the general load 102 temporarily falls into an overload state, rather than when the ground faults 200 and 201 occur, the voltage detected by the first voltage sensor 51 may temporarily fall below the ground fault threshold. Furthermore, in the power supply device 1, when the second load 103 falls into an overload state, the voltage detected by the second voltage sensor 52 may temporarily fall below the ground fault threshold.

[0048] In this case, in the power supply device 1, power is continuously supplied from the first power source 10 to the first load 101 and the general load 102, and from the second load 103 to the second load 103. Therefore, after provisionally determining that a ground fault has occurred in the first system 110 or the second system 120, the control unit 3 officially determines that there is no abnormality in the power supply if the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 both return to exceeding the ground fault threshold before a predetermined time has elapsed. Thereafter, the control unit 3 turns off the battery switch 42 and re-opens the inter-system switch 41 to return to normal operation shown in FIG. 2.

[0049] [4. Charging operation of the power supply] Furthermore, when the SOC of the second power source 20 falls below a predetermined value (for example, SOC: 80%), the power supply device 1 charges the second power source 20 so that the SOC of the second power source 20 returns to the predetermined value. In this case, as shown in Fig. 6 , the control unit 3 supplies power from the first power source 10 to the second power source 20 via the DC / DC converter 53 with the inter-system switch 41 conductive, the bypass switch 43 cut off, and the battery switch 42 conductive, thereby charging the second power source 20.

[0050] [5. Backup availability determination] Next, the backup availability determination performed by the determining unit 31 will be described with reference to Figs. 7 to 9. Fig. 7 is an explanatory diagram showing an example of application periods of first characteristic information and second characteristic information according to the embodiment. Fig. 8 is an explanatory diagram of first characteristic information according to the embodiment. Fig. 9 is an explanatory diagram of second characteristic information according to the embodiment.

[0051] As shown in Fig. 7, the cell resistance value of the LiB21 increases with time and use as the degradation state of the LiB21 progresses from BOL to EOL. The cell resistance value of the LiB21 also varies due to individual differences between the battery cells included in the LiB21. The calculated cell resistance value of the LiB21 also varies due to individual differences between the calculation circuits included in the determination unit 31.

[0052] Here, if the backup feasibility determination is performed based on the calculation error lower limit of the calculated cell resistance value, for example, even if the determination result indicates that backup is possible, there is a risk that the actual cell resistance value will reach the EOL cell resistance value, making backup impossible. Therefore, in consideration of safety, the determination unit 31 determines whether backup is possible based on the calculation error upper limit of the cell resistance value. The calculation error upper limit of the cell resistance value can be obtained, for example, by adding a predetermined error value to the calculated cell resistance value.

[0053] Specifically, the judgment unit 31 calculates the cell resistance value of LiB21, and if the upper limit value of the calculation error of the calculated cell resistance value is equal to or greater than the EOL cell resistance value, judges that backup is not possible (impossible) without using the first characteristic information 61 and the second characteristic information 62.

[0054] As a result, the judgment unit 31 can ensure safety by judging that backup is not possible when the cell resistance value of LiB21 is approaching the EOL cell resistance value within the range of calculation error, even if it has not actually reached the EOL cell resistance value.

[0055] Furthermore, if the calculated cell resistance value of LiB 21 is equal to or greater than the EOL cell resistance value, determination unit 31 may be configured to determine that backup is not possible without using first characteristic information 61 and second characteristic information 62. In this way, determination unit 31 can extend the backup possible period as much as possible by determining that backup is possible (enabled) until just before the cell resistance value reaches the EOL cell resistance value.

[0056] In addition, during a period when the upper limit value of the calculation error of the cell resistance value of LiB21 is equal to or greater than the intermediate cell resistance value and less than the EOL cell resistance value, the judgment unit 31 uses an EOL cell resistance map, which is an example of the first characteristic information 61, to determine whether backup is possible.

[0057] Furthermore, the determination unit 31 may be configured to determine whether backup is possible based on the first characteristic information 61 during a period when the calculated cell resistance value of the LiB21 is equal to or greater than the intermediate cell resistance value and less than the EOL cell resistance value. Note that the determination unit 31 may be configured to determine whether backup is possible based on the first characteristic information 61 during a period when the calculated cell resistance value of the LiB21 is equal to or greater than the intermediate cell resistance value.

[0058] 8, the EOL cell resistance map, which is an example of the first characteristic information 61, is map information that indicates a backup possible region A1 determined by the SOC of the second power source 20 and the temperature of the second power source 20 when the cell resistance value of the second power source 20 is an EOL cell resistance value corresponding to the battery life. The determination unit 31 determines that backup is possible if the SOC of the second power source 20 and the temperature of the second power source 20 are within the backup possible region A1, and determines that backup is not possible if they are not within the backup possible region A1.

[0059] In this way, the judgment unit 31 can accurately determine whether backup is possible by a simple process of checking to which position in the EOL cell resistance map the SOC of the second power source 20 and the temperature of the second power source 20 obtained from the second power source 20 correspond.

[0060] Furthermore, during a period in which the upper limit of calculation error in the cell resistance value of the LiB21 is less than the intermediate cell resistance value, the determination unit 31 determines whether backup is possible using an intermediate cell resistance map, which is an example of the second characteristic information 62. Furthermore, the determination unit 31 may be configured to determine whether backup is possible based on the second characteristic information 62 during a period in which the calculated cell resistance value of the LiB21 is less than the intermediate cell resistance value.

[0061] The intermediate cell resistance map, which is an example of the second characteristic information 62, is map information that indicates the backup possible regions A1, A2 determined by the SOC of the second power source 20 and the temperature of the second power source 20 when the cell resistance value of the second power source 20 is a predetermined resistance value (intermediate cell resistance value) between the EOL cell resistance value corresponding to the battery life and the cell resistance value of the second power source 20 in a BOL state without degradation, as shown in FIG.

[0062] The intermediate cell resistance map has the same backup possible region A1 as the EOL cell resistance map, but also has a backup possible region A2 that is further expanded to the low SOC side and low temperature side. The determination unit 31 determines that backup is possible if the SOC and temperature of the second power supply 20 are within the backup possible regions A1 and A2, and determines that backup is not possible if they are not within the backup possible regions A1 and A2.

[0063] Therefore, even if the second power source SOC and temperature are slightly outside (lower than) the backup possible region A1 in a warm region, the determination unit 31 determines that backup is possible if the backup is possible in a cold region and is included in the backup possible region A2. This allows the determination unit 31 to accurately determine whether backup by the second power source 20 is possible even in a cold region.

[0064] [6. Processing performed by the control unit] Next, the processing executed by the determining unit 31 of the power supply device 1 will be described with reference to Fig. 10. Fig. 10 is a flowchart showing an example of the processing executed by the determining unit 31 of the power supply device 1 according to the embodiment.

[0065] 10, when the determination unit 31 is started, it first calculates the cell resistance of the LiB 21 (step S101) and determines whether the cell resistance value is smaller than the EOL cell resistance value (step S102). If the determination unit 31 determines that the cell resistance value is equal to or greater than the EOL cell resistance value (step S102, No), it determines that backup is not possible (step S112) and ends the process.

[0066] If the determination unit 31 determines that the cell resistance value is smaller than the EOL cell resistance value (step S102, Yes), it determines whether the cell resistance value is smaller than the intermediate cell resistance value (step S103).If the determination unit 31 determines that the cell resistance value is equal to or greater than the intermediate cell resistance value (step S103, No), it performs an EOL cell resistance map determination (step S108) and determines whether the SOC and temperature of the LiB 21 are within the backup possible region A1 (step S109).

[0067] If the determination unit 31 determines that the SOC and temperature of the LiB 21 are not within the backup possible area A1 (step S109, No), it determines that backup is not possible (step S111) and ends the process.If the determination unit 31 determines that the SOC and temperature of the LiB 21 are within the backup possible area A1 (109, Yes), it determines that backup is possible (step S110) and ends the process.

[0068] Furthermore, if the judgment unit 31 determines that the cell resistance value is smaller than the intermediate cell resistance value (step S103, Yes), it performs an intermediate cell resistance map judgment (step S104) and determines whether the SOC and temperature of the LiB21 are within the backup possible regions A1 and A2 (step S105).

[0069] If the determination unit 31 determines that the SOC and temperature of the LiB 21 are not within the backup possible ranges A1 and A2 (step S105, No), it determines that backup is not possible (step S107) and ends the process.If the determination unit 31 determines that the SOC and temperature of the LiB 21 are within the backup possible ranges A1 and A2 (105, Yes), it determines that backup is possible (step S106) and ends the process.

[0070] 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]

[0071] 1 Power supply 10 1st power supply 11 DC / DC 12 PbB 20 2nd power supply 21 LiB 22 lines 3. Control Unit 31 Judgment section 41 Intersystem switch 42 Battery switch 43 Bypass switch 51 First voltage sensor 52 Second voltage sensor 53 DC / DC 6 Memory section 61 First characteristic information 62 Second characteristic information 100 Automatic driving control device 101 1st load 102 General load 103 2nd load 110 1st system 120 2nd system A1, A2 backup area

Claims

1. A power supply device that backs up a first power supply with a second power supply when the first power supply is abnormal, a storage unit that stores first characteristic information and second characteristic information, which are characteristic information of the second power source; when the cell resistance value of the second power source is less than the first cell resistance value and is equal to or greater than a second cell resistance value that is smaller than the first cell resistance value, determining whether backup is possible based on the first characteristic information; a control unit that determines whether backup is possible based on the second characteristic information when the cell resistance value of the second power supply is less than the second cell resistance value; and A power supply device comprising:

2. the first characteristic information and the second characteristic information are map information indicating a backup possible region determined by a state of charge (SOC) of the second power source and a temperature of the second power source, The control unit determines that backup is possible if the SOC of the second power source and the temperature of the second power source are within the backup possible region. The power supply device of claim 1 .

3. The first cell resistance value is a cell resistance value of the second power source corresponding to a battery life; The second cell resistance value is a predetermined resistance value between a cell resistance value of the second power source corresponding to the battery life and a cell resistance value of the second power source in a state without deterioration. The power supply device according to claim 1 or 2.

4. The control unit determines that backup is impossible when a cell resistance value of the second power supply is equal to or greater than the first cell resistance value. The power supply device according to any one of claims 1 to 3.

5. A control method for controlling a power supply device that is backed up by a second power supply when a first power supply is abnormal, using a control device, comprising: When the cell resistance value of the second power source is less than the first cell resistance value and is equal to or greater than a second cell resistance value that is smaller than the first cell resistance value, a determination is made as to whether backup is possible based on first characteristic information stored in a storage unit, and when the cell resistance value of the second power source is less than the second cell resistance value, a determination is made as to whether backup is possible based on second characteristic information stored in a storage unit. Control method.

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