Power supply control device, power supply control method, and power supply control program

Abstract

To provide a power supply control device, a power supply control method, and a power supply control program, capable of performing a quick charge of a backup power supply.SOLUTION: A power supply control device according to an embodiment comprises: a controller; a DC-DC converter; and a backup switch. The controller performs a backup control by switching the controller into a backup power supply when a main power supply is in fault. The DC-DC converter is connected to between the main power supply and the backup power supply. The backup switch connects the main power supply and the backup power supply while bypassing the DC-DC converter. The controller selects a charging processing of which a charging current is larger from a first charging processing for directly charging the backup power supply from the main power supply by conducting the backup switch in the case where the backup power supply is charged and a second charging processing for charging the backup power supply via the DC-DC converter from the main power supply by disconnecting the backup switch.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A power supply control device is known that is installed in a vehicle equipped with an autonomous driving function and performs backup control using a backup power supply when the main power supply fails (for example, see Patent Document 1). In this prior art, if the charge level of the backup power supply is insufficient before the autonomous driving starts, the backup power supply is charged from the main power supply via a DC-DC converter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-125004 Summary of the Invention [Problem to be solved by the invention]

[0004] However, DC-DC converters have current limits and cannot meet the demands of rapid charging.

[0005] One aspect of the embodiments has been made in view of the above, and aims to provide a power supply control device, a power supply control method, and a power supply control program that are capable of rapid charging of a backup power supply. [Means for solving the problem]

[0006] A power supply control device according to an embodiment includes a controller, a DCDC converter, and a backup switch. When a main power supply fails, the controller switches to a backup power supply and performs backup control. The DCDC converter is connected between the main power supply and the backup power supply. The backup switch connects the main power supply and the backup power supply, bypassing the DCDC converter. When charging the backup power supply, the controller selects a charging process with a larger charging current from among a first charging process in which the backup switch is turned on and the backup power supply is directly charged from the main power supply, and a second charging process in which the backup switch is turned off and the backup power supply is charged from the main power supply via the DCDC converter. Effect of the Invention

[0007] Advantageous Effects of Invention According to a power supply control device, a power supply control method, and a power supply control program according to an aspect of an embodiment, it is possible to achieve rapid charging of a backup power supply. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram of the configuration and operation of a power supply control device according to an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram of the configuration and operation of the power supply control device according to the embodiment. [Diagram 3] FIG. 3 is an explanatory diagram of the charging process according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram of the charging process according to the embodiment. [Diagram 5] FIG. 5 is an explanatory diagram of the charging process according to the embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of a charging process executed by the controller according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of a power supply control device, a power supply control method, and a power supply control program will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiment. In the following, a case will be described in which a vehicle equipped with a power supply control device according to the embodiment is an engine automobile that has an automatic driving function and runs on an internal combustion engine.

[0010] The vehicle in which the power supply control device according to the embodiment is installed may be an electric vehicle or a hybrid vehicle equipped with an automatic driving function. The power supply control device according to the embodiment is a device that supplies electric power to various loads installed in the vehicle.

[0011] [1. Power supply control device configuration] The configuration and operation of a power supply control device 1 according to an embodiment will be described with reference to Figures 1 and 2. Figures 1 and 2 are explanatory diagrams of the configuration and operation of a power supply control device 1 according to an embodiment. As shown in Figure 1, the power supply control device 1 according to an embodiment is connected to a main power supply 10, a first load 101, a general load 102, a second load 103, and an external device 100.

[0012] The power supply control device 1 includes a first system 110 and a second system 120. The first system 110 is a power supply system that supplies power from a main power supply 10 to a first load 101 and a general load 102. The second system 120 is a power supply system that supplies power from a backup power supply 20 (described later) to a second load 103.

[0013] The first load 101 includes a load for automatic driving. The first load 101 includes, for example, a steering motor, an electric brake device, an in-vehicle camera, etc. that operate during automatic driving. The general load 102 is a load that is not involved in automatic driving, and includes a display, an air conditioner, an audio device, a video device, various lights, etc.

[0014] The second load 103 has some of the functions for automatic driving that the first load 101 has. The second load 103 includes, for example, a steering motor, an electric brake device, and a radar, which are minimum devices required for FOP (Fail Operation, evacuation drive control). The first load 101, the general load 102, and the second load 103 operate with power supplied from the power supply control device 1.

[0015] The external device 100 is a host ECU (Electronic Control Unit) having a function of controlling automatic driving of the vehicle by operating a first load 101 and a second load 103, a function of monitoring the state of the main power supply 10, and a function of controlling a generator 11 described later. The external device 100 monitors the voltage of PbB 12 acquired via a state monitoring line 13, and outputs the voltage value of PbB 12 to a controller 3 of the power supply control device 1 described later.

[0016] When a power supply abnormality such as a ground fault occurs in the first system 110 during automatic driving of the vehicle, the external device 100 can implement FOP by the second load 103. Also, when a power supply abnormality such as a ground fault occurs in the second system 120, the external device 100 can implement FOP by the first load 101.

[0017] The main power supply 10 includes a generator 11 and a lead battery (hereinafter, referred to as "PbB12"). The PbB12 is a secondary power supply capable of outputting a voltage of 12V when fully charged. The battery of the main power supply 10 may be any secondary battery other than the PbB12.

[0018] The generator 11 includes an alternator and an AC / DC converter. The alternator generates electricity by converting the kinetic energy of a running vehicle into electricity. The AC / DC converter converts the AC power generated by the alternator into DC power.

[0019] The AC / DC converter is set with a limit current that is the maximum current that can be designed to flow upstream. The generator 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 backup power source 20, which will be described later.

[0020] When the main power supply 10 is mounted on an electric vehicle or a hybrid vehicle, it is connected to a high-voltage battery having a higher voltage than the PbB 12. The high-voltage battery is a battery mounted on the electric vehicle or hybrid vehicle for driving the vehicle.

[0021] In this case, the main power supply 10 is provided with a DC / DC converter instead of the generator 11. The DC / DC converter steps down the voltage of the high-voltage battery to 12V that can be output when the PbB 12 is fully charged, and outputs the voltage to the first system 110. The DC / DC converter is set with a limit current that is the maximum current that can be output by design.

[0022] The power supply control device 1 includes a backup power supply 20, an inter-system switch 41, a battery switch 42, and a backup switch 43. The power supply control device 1 further includes a DC / DC converter (hereinafter, referred to as “DC / DC 23”), a controller 3, a first voltage sensor 51, and a second voltage sensor 52.

[0023] The backup power supply 20 is a backup power supply in the event that the main power supply 10 is unable to supply power. The backup power supply 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). The LiB21 is a battery capable of outputting a higher voltage than the PbB12 when fully charged. The LiB21 can output a voltage of, for example, 16V. The battery of the backup power supply 20 may be any secondary battery other than the LiB21.

[0024] The inter-system switch 41 is provided on an inter-system line 130 that connects the first system 110 and the second system 120. The inter-system switch 41 is a switch that can connect and disconnect the first system 110 and the second system 120.

[0025] The inter-system switch 41, when in a conductive state, electrically connects the first system 110 and the second system 120. Moreover, the inter-system switch 41, when in a cut-off state, cuts off the electrical connection between the first system 110 and the second system 120.

[0026] The inter-system switch 41 may be configured by a DC / DC converter. In this case, the DC / DC converter electrically connects the first system 110 and the second system 120 by starting operation. Moreover, the DC / DC converter cuts off the electrical connection between the first system 110 and the second system 120 by stopping operation.

[0027] The battery switch 42 is a switch that connects the backup power supply 20 to the backup switch 43 and the DC / DC 23. When the battery switch 42 is in a conductive state, it electrically connects the backup power supply 20 to the backup switch 43 and the DC / DC 23. When the battery switch 42 is in a cutoff state, it cuts off the electrical connection between the backup power supply 20 and the backup switch 43 and the DC / DC 23.

[0028] The DC / DC 23 is connected between the main power supply 10 and the backup power supply 20. The DC / DC 23 can boost the voltage supplied from the main power supply 10 to, for example, 16 V that the LiB 21 can output when fully charged, and supply the boosted voltage to the backup power supply 20. In addition, the DC / DC 23 has a limit current set as the maximum current that can be output by design.

[0029] The backup switch 43 is a switch that bypasses the DC / DC 23 and connects the main power supply 10 and the backup power supply 20. The backup switch 43 also connects the battery switch 42 and the second system 120. When the backup switch 43 is in a conductive state, it electrically connects the battery switch 42 and the second system 120. When the backup switch 43 is in a cutoff state, it cuts off the electrical connection between the battery switch 42 and the second system 120.

[0030] The first voltage sensor 51 is provided in the first system 110. The first voltage sensor 51 detects the voltage of the first system 110 (hereinafter referred to as the “first system voltage”) and outputs the detection result to the controller 3. The second voltage sensor 52 is provided in the second system 120. The second voltage sensor 52 detects the voltage of the second system 120 (hereinafter referred to as the “second system voltage”) and outputs the detection result to the controller 3.

[0031] The controller 3 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), etc., and various other circuits. The controller 3 may be configured with hardware such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0032] The controller 3 executes a program stored in the ROM by using the RAM as a working area, and thereby switches to the backup power supply 20 and performs backup control when the main power supply 10 fails.

[0033] The controller 3 controls the conduction and interruption of the system switch 41, the battery switch 42, and the backup switch 43. Furthermore, the controller 3 controls the operation of the DC / DC 23 and the charging of the main power supply 10 and the backup power supply 20.

[0034] Furthermore, the controller 3 acquires information indicating the remaining charge of the backup power supply 20 from the backup power supply 20 via the status monitoring line 22. The information indicating the remaining charge of the backup power supply 20 is, for example, the SOC (State Of Charge) of the LiB 21 and the voltage value of the LiB 21.

[0035] The LiB 21 is in a state where the remaining charge is maximum when the SOC is 100%. The LiB 21 is in a state where the remaining charge is zero when the SOC is 0%. The controller 3 monitors the remaining charge of the backup power source 20 based on the SOC of the LiB 21, and determines that charging of the backup power source 20 is required when the SOC of the LiB 21 falls below 80%, for example. A specific example of the charging process of the backup power source 20 executed by the controller 3 will be described later with reference to Figs. 3 to 5.

[0036] The controller 3 detects a power failure of 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. The power failure is, for example, a ground fault. When the controller 3 detects a ground fault of the first system 110 or the second system 120, it notifies the external device 100 of the detection.

[0037] Specifically, when the controller 3 detects a ground fault in the first system 110 or the second system 120, it outputs an automatic driving prohibition signal indicating that automatic driving is not possible to the external device 100. In addition, when the controller 3 does not detect a ground fault in the first system 110 or the second system 120, it outputs an automatic driving permission signal indicating that automatic driving is possible to the external device 100.

[0038] [2. Normal operation of the power supply control device] During normal operation when no power failure is detected in the first system 110 and the second system 120, the controller 3 turns on the inter-system switch 41 while keeping the battery switch 42 and the backup switch 43 in an OFF state, as shown in FIG.

[0039] In this way, the controller 3 supplies power from the main power supply 10 to the first load 101, the general load 102, and the second load 103. Note that the controller 3 outputs an automatic operation permission signal to the external device 100 during normal times when no abnormality occurs in the first system 110 and the second system 120.

[0040] [3. Operation of the power supply control device when power failure is detected] The controller 3 detects the occurrence of a power supply failure by comparing a parameter relating to a failure in the first system 110 or the second system 120 with a threshold value.

[0041] Here, a case will be described in which the parameter related to a failure in the first system 110 is the voltage of the first system 110, and the parameter related to a failure in the second system 120 is the voltage of the second system 120.

[0042] The parameter related to the abnormality in the first system 110 may be a current flowing through the first system 110 or a current flowing through the second system 120. In this case, the power supply control device 1 includes a current sensor that detects the current flowing through the first system 110 and a current sensor that detects the current flowing through the second system 120. Then, the controller 3 detects the occurrence of a ground fault when the current flowing through the first system 110 or the current flowing through the second system 120 exceeds an overcurrent threshold.

[0043] As shown in FIG. 2, in the power supply control 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 first system voltage and the second system voltage become equal to or lower than the ground fault threshold value.

[0044] For example, when the second system voltage becomes equal to or lower than the ground fault threshold, the controller 3 provisionally determines that a ground fault has occurred in the first system 110 or the second system 120. After that, the controller 3 outputs an automatic operation prohibition signal to the external device 100. Then, when the controller 3 provisionally determines that a ground fault has occurred, it shuts off the inter-system switch 41 and conducts the battery switch 42 and the backup switch 43 to perform pre-shutoff control.

[0045] As a result, the connection between the first system 110 and the second system 120 is cut off, so that power is supplied from the main power source 10 to the first system 110, and power is supplied from the backup power source 20 to the second system 120. Thereafter, the controller 3 performs a main determination to determine which of the first system 110 and the second system 120 has had a ground fault.

[0046] That is, the controller 3 shuts off the inter-system switch 41 and turns on the battery switch 42 and the backup switch 43, so that the voltage in the system with the ground fault continues to drop, while the voltage in the normal system without the ground fault recovers to a normal value. Therefore, the controller 3 judges which system has the ground fault and which system is normal by checking the state of voltage recovery of each system after the pre-shutdown.

[0047] If, after the pre-shutdown, the first system voltage is equal to or lower than the ground fault threshold for a predetermined period or more and the second system voltage is restored to equal to or higher than the normal threshold which is higher than the ground fault threshold for a predetermined period or more, the controller 3 determines that the second system 120 is normal and that the ground fault 200 has occurred in the first system 110. The predetermined period here is, for example, 100 ms. Note that the predetermined period is not limited to 100 ms. The normal threshold is a value higher than the ground fault threshold.

[0048] If the controller 3 determines that a ground fault 200 has occurred in the first system 110, it performs fail-safe control to supply power from the backup power source 20 to the second load 103, as shown in FIG. 2, and notifies the external device 100 of this fact.

[0049] As a result, the external device 100 can operate the second load 103 using power supplied from the backup power source 20 and evacuate the vehicle to a safe place and stop the vehicle. Note that the fail-safe control may also include shutting off the inter-system switch 41 based on a provisional determination, turning on the battery switch 42, and notifying the external device 100 of the actual determination.

[0050] In addition, after the pre-shutdown, if the first system voltage returns to above the normal threshold for a predetermined period of time or more and the second system voltage is below the ground fault threshold for a predetermined period of time or more, the controller 3 makes a final determination that the first system 110 is normal and that a ground fault has occurred in the second system 120.

[0051] When the controller 3 determines that a ground fault has occurred in the second system 120, it performs fail-safe control by shutting off the battery switch 42 and the backup switch 43 to supply power from the main power supply 10 to the first load 101 and the general load 102.

[0052] Then, the controller 3 notifies the external device 100 of this fact. As a result, the external device 100 can operate the first load 101 with the power supplied from the main power supply 10, and can evacuate the vehicle to a safe place and stop the vehicle.

[0053] In this way, when the controller 3 detects a ground fault in the first system 110 or the second system 120, it turns the inter-system switch 41 to an interrupted state. Then, the controller 3 performs fail-safe control to supply power through the normal system of the first system 110 or the second system 120.

[0054] Furthermore, if both the first system voltage and the second system voltage are restored to be equal to or higher than the normal threshold for a predetermined period or more after the pre-shutdown, the controller 3 determines that the voltage drop is a temporary voltage drop and that no ground fault has occurred. In other words, the controller 3 determines that both the first system 110 and the second system 120 are normal. In this case, the controller 3 performs a recovery control to restore the normal operation state of FIG. 1.

[0055] However, in the power supply control device 1, the voltage of the backup power supply 20 may drop due to natural discharge of the LiB 21, etc. In this case, the controller 3 needs to promptly charge the backup power supply 20 in preparation for autonomous driving or the occurrence of a ground fault. Therefore, the controller 3 is capable of rapid charging of the backup power supply 20 when the voltage of the backup power supply 20 drops. Hereinafter, the charging operation and charging process of the backup power supply 20 executed by the controller 3 will be described.

[0056] [4. Charging operations performed by the controller] 3 to 5 are explanatory diagrams of charging processing according to the embodiment. The battery icons shown in Figs. 3 to 5 are schematic representations of the amount of stored power in the battery. The number of black rectangles in the battery icon indicates the amount of stored power in the secondary battery. In other words, the secondary battery corresponding to the battery icon with a larger number of black rectangles has a larger amount of stored power.

[0057] When charging the backup power supply 20, the controller 3 enables high-speed charging by selecting a charging process with a large charging current from two types of charging processes, broadly classified as a first charging process and a second charging process.

[0058] The first charging process is a charging process in which the backup switch 43 is turned on and the backup power supply 20 is charged directly from the main power supply 10. The second charging process is a charging process in which the backup switch 43 is turned off and the backup power supply is charged from the main power supply 10 via the DC / DC 23.

[0059] The first charging process includes a third charging process in which the backup power source 20 is charged directly from the PbB 12, and a fourth charging process in which the backup power source 20 is charged directly from the generator 11. The controller 3 selects the charging process with the largest charging current from the second charging process, the third charging process, and the fourth charging process, and selects the backup power source. This enables the controller 3 to charge the backup power source at high speed.

[0060] When performing the third charging process, the controller 3 turns on the backup switch 43 and the battery switch 42 while keeping the system switch 41 conductive, as shown in Fig. 3. At this time, the controller 3 stops the operation of the DC / DC converter 23 and does not request the external device 100 to start the operation of the alternator of the generator 11.

[0061] As a result, the backup power supply 20 is charged by power supplied from PbB11 via the system switch 41, the backup switch 43, and the battery switch 42. At this time, the charging current I1 is determined based on the difference between the voltage value V1 of PbB12 and the voltage value V2 of LiB21, and the combined resistance R of the resistance value of the charging path and the internal resistance of LiB21. Specifically, it can be derived by I1=(V1-V2) / R (1).

[0062] For this reason, the controller 3 acquires the voltage value V1 of PbB12 from the external device 100, and acquires the voltage value V2 of LiB21 from the backup power supply 20. Note that the controller 3 may acquire the first system voltage acquired from the first voltage sensor 51 with the inter-system switch 41 in a cut-off state as the voltage value V1 of PbB12.

[0063] Furthermore, the controller 3 may obtain the second system voltage from the second voltage sensor 52 as the voltage value V2 of the LiB 21 with the inter-system switch 41 cut off and the battery switch 42 and the backup switch 43 in a conductive state.

[0064] Moreover, the controller 3 can calculate the internal resistance of the LiB 21 from information indicating the remaining charge of the backup power source 20 at the time of startup, and can calculate the charging current I1 in the third charging process by the above formula (1) because the resistance value of the charging path in the third charging process is known. In other words, the controller 3 can calculate the charging current in the first charging process.

[0065] In this way, the controller 3 calculates the charging current of the third charging process based on the voltage value of the main power supply 10 when the alternator of the generator 11 is not operating and the voltage value of the backup power supply. In other words, the controller 3 calculates the charging current of the first charging process. This allows the controller 3 to accurately calculate the charging current when charging the backup power supply 20 with power only from PbB 12.

[0066] As is clear from the above formula (1), the third charging process increases the charging current as the difference between the voltage value V1 of PbB12 and the voltage value V2 of LiB21 increases. Therefore, the third charging process is more effective for high-speed charging as PbB12 approaches a fully charged state. However, when the voltage value V1 of PbB12 and the voltage value V2 of LiB21 become equal, the third charging process is no longer able to perform any further charging.

[0067] 4, when the fourth charging process is performed, the controller 3 turns on the backup switch 43 and the battery switch 42 while keeping the system switch 41 conductive, and outputs an operation start request for the generator 11 to the external device 100. At this time, the controller 3 stops the operation of the DC / DC 23.

[0068] This allows the controller 3 to directly charge the backup power supply 20 with the power generated by the generator 11 even when the voltage value V1 of the PbB 12 is lower than the voltage value V2 of the LiB 21 as shown in FIG.

[0069] However, as described above, the maximum voltage that the generator 11 can output is 12 V, which is equal to the voltage value when the PbB 12 is fully charged. Therefore, in the fourth charging process, when the voltage value V2 of the LiB 21 reaches 12 V, further charging is not possible. Also, the upper limit of the charging current that can be supplied by the generator 11 is the limited current set in the alternator.

[0070] Therefore, when the fourth charging process is performed, the controller 3 can calculate the charging current I2 for the fourth charging process based on the limit current set in the alternator, which allows the controller 3 to accurately calculate the charging current when the backup power supply 20 is directly charged from the generator of the main power supply 10.

[0071] Here, the case where the main power supply 10 includes the generator 11 has been described, but as described above, when the main power supply 10 is mounted on an electric vehicle or a hybrid vehicle, an AC / DC converter connected to a high-voltage battery is provided instead of the generator 11. In this case, when performing the fourth charging process, the controller 3 can calculate the charging current I2 for the fourth charging process based on the limit current set in the AC / DC converter.

[0072] In addition, when performing the second charging process, as shown in FIG. 5, the controller 3 turns on the system switch 41 and the battery switch 42 while keeping the backup switch 43 disconnected, and outputs a request to start operating the generator 11 to the external device 100 as necessary.

[0073] The controller 3 does not operate the generator 11 when the voltage of PbB 12 is equal to or higher than a threshold voltage close to full charge, and operates the generator 11 when the voltage is equal to or lower than the threshold voltage.

[0074] Then, the controller 3 operates to boost the DC / DC 23. As a result, the backup power supply 20 is charged by boosting the voltage of the main power supply 10, that is, the voltage of the PbB 12 or the generator 11, by the DC / DC 23.

[0075] At this time, as described above, the DC / DC 23 can boost the voltage supplied from the main power supply 10 to 16 V, which is the voltage when the LiB 21 is fully charged. Therefore, in the second charging process, even after the voltage value V2 of the LiB 21 reaches 12 V, which is the maximum voltage that the main power supply 10 can output, charging can be continued until the voltage value V2 of the LiB 21 reaches 16 V. However, as described above, the DC / DC 23 has a limit current that can be passed.

[0076] Therefore, when the second charging process is performed, the controller 3 can calculate the charging current I3 of the second charging process based on the limit current set in the DC / DC 23. This allows the controller 3 to accurately calculate the charging current when charging the backup power supply 20 from the main power supply 10 via the DC / DC 23.

[0077] Thus, in terms of high-speed charging, the second charging process, the third charging process, and the fourth charging process each have advantages and disadvantages depending on the state of the voltage value V1 of PbB12 and the voltage value V2 of LiB21.

[0078] Therefore, the controller 3 selects the charging process with the largest charging current from among the charging current I3 of the second charging process in which charging is performed with a limited current by the DC / DC 23, the charging current I1 of the third charging process, and the charging current I2 of the fourth charging process in which charging is performed with a limited current by the alternator.

[0079] This allows the controller 3 to select the charging process capable of charging the backup power supply 20 in the shortest time from the second charging process, the third charging process, and the fourth charging process, and to perform high-speed charging.

[0080] [5. Charging process performed by the controller] Fig. 6 is a flowchart showing an example of a charging process executed by a controller according to an embodiment. The controller 3 repeatedly executes the process shown in Fig. 6 while the vehicle is running, and ends the process when the start-up of the vehicle is finished.

[0081] Specifically, as shown in Fig. 6, when the vehicle is started, the controller 3 first determines whether charging of the backup power supply 20 is necessary (step S101). If the SOC of the LiB 21 is less than 80%, the controller 3 determines that charging is necessary. Also, if the SOC of the LiB 21 is 80% or more, the controller 3 determines that charging is not necessary.

[0082] When the controller 3 determines that charging is not required (step S101, No), it ends the process and restarts the process from step S101. When the controller 3 determines that charging is required (step S101, Yes), it calculates the charging current I1 of the second charging process, the charging current I2 of the third charging process, and the charging current I3 of the fourth charging process (step S102).

[0083] Next, the controller 3 determines whether or not the voltage value of the backup power supply 20 has reached the full charge voltage value of the main power supply 10 (step S103). If the controller 3 determines that the voltage value of the backup power supply 20 has not reached the full charge voltage value of the main power supply 10 (step S103, No), the controller 3 proceeds to step S105.

[0084] In step S105, the controller 3 selects the charging process with the largest charging current from among the charging currents I1, I2, and I3, charges the backup power supply 20, and moves the process to step S101. This enables the controller 3 to shorten the charging time required for the voltage value of the backup power supply 20 to reach the full charge voltage value of the main power supply 10 as much as possible.

[0085] Furthermore, when the controller 3 determines that the voltage value of the backup power supply 20 has reached the full charge voltage value of the main power supply 10 (Yes in step S103), it selects the second charging process to charge the backup power supply 20 (step S104) and moves the process to step S101. That is, the controller 3 charges the backup power supply 20 with the voltage of 16 V that the DC / DC 23 can output, and moves the process to step S101.

[0086] In this way, the controller 3 selects the charging process with the largest charging current until the voltage value of the backup power source 20 reaches the voltage value of the main power source 10 in the fully charged state, and selects the second charging process after the voltage value of the backup power source 20 reaches the voltage value of the main power source 10 in the fully charged state.

[0087] As a result, even if the voltage value of the backup power supply 20 reaches the voltage value of the main power supply 10 in a fully charged state, the controller 3 continues charging until the backup power supply 20 is fully charged, thereby ensuring that the charging of the backup power supply 20 is completed.

[0088] [6. Notes] As an appendix, the features of the present invention are as follows: (1) a controller that switches to a backup power source and performs backup control when the main power source fails; A DC-DC converter connected between the main power supply and the backup power supply; a backup switch that bypasses the DC-DC converter and connects the main power supply and the backup power supply; A power supply control device comprising: The controller: When charging the backup power source, a charging process with a larger charging current is selected from a first charging process in which the backup switch is turned on and the backup power source is directly charged from the main power source, and a second charging process in which the backup switch is turned off and the backup power source is charged from the main power source via the DCDC converter. Power control device. (2) The main power source includes a secondary battery and a generator. The first charging process includes a third charging process in which the backup power source is charged directly from the secondary battery, and a fourth charging process in which the backup power source is charged directly from the generator, The controller: A charging process that has the largest charging current is selected from the second charging process, the third charging process, and the fourth charging process. The power supply control device according to (1) above. (3) The controller: Calculating a charging current for the first charging process based on a voltage value of the main power source and a voltage value of the backup power source. The power supply control device according to (1) or (2). (4) The generator includes an alternator. The controller: Calculating a charging current for the third charging process based on a voltage value of the main power source and a voltage value of the backup power source when the alternator is not in operation. The power supply control device according to (2) above. (5) The controller: A charging process with the largest charging current is selected from among the charging current of the second charging process in which charging is performed with a limited current by the DCDC converter, the charging current of the third charging process, and the charging current of the fourth charging process in which charging is performed with a limited current by the alternator. The power supply control device according to (4) above. (6) a voltage value of the backup power supply in a fully charged state is higher than a voltage value of the main power supply in a fully charged state; The controller: A charging process with the largest charging current is selected until the voltage value of the backup power source reaches the voltage value of the main power source in the fully charged state, and the second charging process is selected after the voltage value of the backup power source reaches the voltage value of the main power source in the fully charged state. The power supply control device according to any one of (1) to (5). (7) a controller that switches to a backup power source and performs backup control when the main power source fails; A DC-DC converter connected between the main power supply and the backup power supply; a backup switch that bypasses the DC-DC converter and connects the main power supply and the backup power supply; The controller of the power supply control device includes: When charging the backup power source, a charging process with a larger charging current is selected from a first charging process in which the backup switch is turned on and the backup power source is directly charged from the main power source, and a second charging process in which the backup switch is turned off and the backup power source is charged from the main power source via the DCDC converter. A power supply control method comprising: (8) a controller that switches to a backup power source and performs backup control when the main power source fails; A DC-DC converter connected between the main power supply and the backup power supply; a backup switch that bypasses the DC-DC converter and connects the main power supply and the backup power supply; The controller of the power supply control device includes: When charging the backup power source, a charging process with a larger charging current is selected from a first charging process in which the backup switch is turned on and the backup power source is directly charged from the main power source, and a second charging process in which the backup switch is turned off and the backup power source is charged from the main power source via the DCDC converter. A power control program that executes the following:

[0089] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0090] 1 Power supply control device 3. Controller 10 Main power supply 11. Generator 13 Condition monitoring line 20 Backup Power 22 Condition monitoring line 41 Intersystem switch 42 Battery switch 43 Backup switch 51 First voltage sensor 52 Second voltage sensor 100 External device 101 1st load 102 General load 103 2nd load 110 1st system 120 2nd system 130 Intersystem Line 200 Earth fault

Claims

1. a controller that switches to a backup power source and performs backup control when the main power source fails; a DC-DC converter connected between the main power supply and the backup power supply; a backup switch that bypasses the DCDC converter and connects the main power supply and the backup power supply; A power supply control device comprising: The controller: When charging the backup power supply, a charging process with a larger charging current is selected from a first charging process in which the backup switch is turned on and the backup power supply is directly charged from the main power supply, and a second charging process in which the backup switch is turned off and the backup power supply is charged from the main power supply via the DCDC converter. Power control device.

2. The main power source includes a secondary battery and a generator. The first charging process includes a third charging process in which the backup power source is charged directly from the secondary battery, and a fourth charging process in which the backup power source is charged directly from the generator, The controller: A charging process that has the largest charging current is selected from the second charging process, the third charging process, and the fourth charging process. The power supply control device according to claim 1 .

3. The controller: Calculating a charging current for the first charging process based on a voltage value of the main power supply and a voltage value of the backup power supply The power supply control device according to claim 1 .

4. The generator includes an alternator. The controller: Calculating a charging current for the third charging process based on a voltage value of the main power source and a voltage value of the backup power source when the alternator is not in operation. The power supply control device according to claim 2.

5. The controller: A charging process with the largest charging current is selected from among the charging current of the second charging process in which charging is performed with a limited current by the DC-DC converter, the charging current of the third charging process, and the charging current of the fourth charging process in which charging is performed with a limited current by the alternator. The power supply control device according to claim 4.

6. a voltage value of the backup power supply in a fully charged state is higher than a voltage value of the main power supply in a fully charged state; The controller: A charging process with the largest charging current is selected until the voltage value of the backup power source reaches the voltage value of the main power source in the fully charged state, and the second charging process is selected after the voltage value of the backup power source reaches the voltage value of the main power source in the fully charged state. The power supply control device according to claim 1 .

7. a controller that switches to a backup power source and performs backup control when the main power source fails; a DC-DC converter connected between the main power supply and the backup power supply; a backup switch that bypasses the DCDC converter and connects the main power supply and the backup power supply; The controller of the power supply control device includes: When charging the backup power supply, a charging process with a larger charging current is selected from a first charging process in which the backup switch is turned on and the backup power supply is directly charged from the main power supply, and a second charging process in which the backup switch is turned off and the backup power supply is charged from the main power supply via the DCDC converter. A power supply control method comprising:

8. a controller that switches to a backup power source and performs backup control when the main power source fails; a DC-DC converter connected between the main power supply and the backup power supply; a backup switch that bypasses the DCDC converter and connects the main power supply and the backup power supply; The controller of the power supply control device includes: When charging the backup power supply, a charging process that produces a larger charging current is selected from a first charging process in which the backup switch is turned on and the backup power supply is directly charged from the main power supply, and a second charging process in which the backup switch is turned off and the backup power supply is charged from the main power supply via the DCDC converter. A power control program that executes the following:

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