Backup power supply system, power supply backup method, and program product

Abstract

The present application provides a kind of backup power supply system, power backup method and program.The backup power supply system (1) of the present application is equipped with the 1st auxiliary power supply (22) and the 2nd auxiliary power supply (3) when main power supply (4) fails, can supply power to the 1st load (5).In the backup power supply system (1), the 2nd time is shorter than the 1st time.The 1st time is until the 1st auxiliary power supply (22) becomes the time of the state that can supply power to the 1st load (5).The 2nd time is until the 2nd auxiliary power supply (3) becomes the time of the state that can supply power to the 1st load (5).

Description

TECHNICAL FIELD

[0001] The present disclosure generally relates to a backup power supply system, a power supply backup method, and a program. More specifically, the present disclosure relates to a backup power supply system, a power supply backup method, and a program that are capable of supplying electric power to a load when a main power supply fails. BACKGROUND

[0002] In Patent Literature 1, a parking assistance device is described that is capable of causing a vehicle to perform a parking operation using a portable terminal from the outside of the vehicle. In the parking assistance device described in Patent Literature 1, in the case where the vehicle has experienced a power supply failure, a P-lock actuator that is capable of causing a shift of the vehicle to be fixed to P range, and a release method of an EPB actuator that controls an Electronic Parking Brake (EPB) are output to the portable terminal.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2018-130978 SUMMARY

[0006] An object of the present disclosure is to provide a backup power supply system, a power supply backup method, and a program that are less likely to become a state in which electric power is not supplied to a load when a main power supply fails.

[0007] A backup power supply system according to one embodiment of the present disclosure includes a first auxiliary power supply and a second auxiliary power supply that are capable of supplying electric power to a load when a main power supply fails. In the backup power supply system, a second time is shorter than a first time. The first time is a time until the first auxiliary power supply becomes a state in which the first auxiliary power supply is capable of supplying electric power to the load. The second time is a time until the second auxiliary power supply becomes a state in which the second auxiliary power supply is capable of supplying electric power to the load.

[0008] A power supply backup method according to one embodiment of the present disclosure is a power supply backup method for a backup power supply system. The backup power supply system includes a first auxiliary power supply and a second auxiliary power supply that are capable of supplying electric power to a load when a main power supply fails. In the backup power supply system, a second time is shorter than a first time. The first time is a time until the first auxiliary power supply becomes a state in which the first auxiliary power supply is capable of supplying electric power to the load. The second time is a time until the second auxiliary power supply becomes a state in which the second auxiliary power supply is capable of supplying electric power to the load.

[0009] A program according to one embodiment of the present disclosure is a program for causing one or more processors to execute the power supply backup method.

[0010] According to the present disclosure, it is possible to prevent the state in which the load is not supplied with electric power at the time of failure of the main power supply. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a diagram showing the structure of a drive system using the backup power supply system according to the embodiment.

[0012] Figure 2 is a side view showing a part of a vehicle on which the backup power supply system is mounted.

[0013] Figure 3 is a flowchart showing an example 1 of the operation of the backup power supply system.

[0014] Figure 4 is a timing chart showing an example 2 of the operation of the backup power supply system.

[0015] Figure 5 is a diagram showing the structure of a backup power supply system according to a modification 1 of the embodiment. DETAILED DESCRIPTION

[0016] (Embodiment)

[0017] The embodiment described below and the modification are only one example of the present disclosure, and the present disclosure is not limited to the embodiment and the modification described below. Even if the embodiment and the modification described below are not used, as long as the embodiment and the modification are within the scope of the technical idea of the present disclosure, various changes can be made according to design and the like.

[0018] (1) Outline

[0019] First, the outline of the backup power supply system 1 according to the embodiment will be described with reference to Figure 1 and Figure 2

[0020] The backup power supply system 1 according to the embodiment is mounted, for example, on a vehicle 9 (see Figure 2 ) and supplies electric power to a load at the time of failure of a main power supply 4 provided in the vehicle 9. That is, the backup power supply system 1 is mounted on the vehicle 9 provided with the main power supply 4 and the load. The "time of failure of the main power supply 4" according to the present disclosure means that the supply of electric power from the main power supply 4 to the load and the like is stopped due to a failure, deterioration, or disconnection of the main power supply 4 and the like.

[0021] The vehicle 9 is provided with a drive system 10 and a vehicle body (vehicle main body) 91 on which the drive system 10 is mounted (see Figure 2 ​). The drive system 10 has the backup power supply system 1, a main power supply 4, a plurality of loads (as an example, a first load 5 and a second load 6), and an ECU (Electronic Control Unit) 7. The main power supply 4 is, for example, a storage battery (as an example, a lead storage battery) mounted on the vehicle 9, and is configured to supply electric power to the plurality of loads. The ECU 7 is configured to control the plurality of loads provided to the vehicle 9.

[0022] The first load 5 is, for example, a brake system (hereinafter, also referred to as "brake system 5"). The second load 6 is, for example, a shift-by-wire system (hereinafter, also referred to as "shift-by-wire system 6"). In addition, in the present embodiment, the "shift-by-wire system 6" is denoted as "SBW system 6". Figure 1

[0023] The brake system 5 is a system that electrically drives a brake mechanism provided to each wheel of the vehicle 9. The brake system 5 has a drive control portion 51 and an actuator 52. The drive control portion 51 outputs a control signal to the actuator 52 based on an operation amount of a brake pedal operated by a driver, thereby controlling driving of the actuator 52. The actuator 52 is configured to actuate the brake mechanism provided to each wheel to apply a brake to each wheel in accordance with the control signal from the drive control portion 51.

[0024] The shift-by-wire system 6 is a system that electrically switches a shift range of an automatic transmission mounted on the vehicle 9. The shift-by-wire system 6 has a drive control portion 61 and an actuator 62. The drive control portion 61 outputs a control signal to the actuator 62 based on a position of a shift lever operated by a driver, thereby controlling driving of the actuator 62. The actuator 62 is configured to switch the shift range of the automatic transmission in accordance with the control signal from the drive control portion 61.

[0025] The shift range of the automatic transmission includes a parking range (P range), a reverse range (R range), a neutral range (N range), and a drive range (D range). The drive range is used when the vehicle 9 is running forward, the reverse range is used when the vehicle 9 is running backward, and the parking range is used when the vehicle 9 is parked. In the parking range, a rotating shaft in the automatic transmission is locked by the actuator 62, and the vehicle 9 is locked.

[0026] The brake system 5 and the shift-by-wire system 6 are configured to operate by electric power supplied from the main power supply 4 or the backup power supply system 1.

[0027] In a case where the main power supply 4 is normal, electric power is supplied from the main power supply 4 to the first load 5 and the second load 6 (i.e., the brake system 5 and the shift-by-wire system 6). On the other hand, in a case where the main power supply 4 is failed, electric power is supplied from the backup power supply system 1 to the first load 5 and the second load 6. Therefore, even in a case where the main power supply 4 is failed, the first load 5 and the second load 6 can operate in accordance with an operation of the driver.​

[0028] Backup power system 1 includes a first auxiliary power source 22 and a second auxiliary power source 3. Each of the first auxiliary power sources 22 and 3 is an auxiliary power source capable of supplying power to the first load (load) 5 when the main power source 4 fails. In backup power system 1, the second time is shorter than the first time. The first time is the time until the first auxiliary power source 22 becomes capable of supplying power to the first load 5. The second time is the time until the second auxiliary power source 3 becomes capable of supplying power to the first load 5. That is, the first time is equivalent to the charging time of the first auxiliary power source 22, and the second time is equivalent to the charging time of the second auxiliary power source 3. The first and second times are relative times.

[0029] In the backup power system 1 according to this embodiment, as described above, the second time corresponding to the charging time of the second auxiliary power supply 3 is shorter than the first time corresponding to the charging time of the first auxiliary power supply 22. Therefore, the charging of the second auxiliary power supply 3 can be completed before the charging of the first auxiliary power supply 22. Thus, even during the period before the first time, power can be supplied to the first load 5 through the second auxiliary power supply 3. Therefore, it has the advantage that, compared with the case where power is supplied to the first load 5 only by the first auxiliary power supply 22 when the main power supply 4 fails, it is less likely to become a state where power is not supplied to the first load 5 when the main power supply 4 fails.

[0030] (2) Details

[0031] Below, refer to Figure 1 Details of the backup power system 1 involved in the implementation method will be described.

[0032] like Figure 1 As shown, the backup power system 1 involved in this embodiment includes a backup power device 2 and a second auxiliary power supply 3.

[0033] Backup power supply unit 2 includes control circuit 21, first auxiliary power supply 22, power supply circuit 23, drive circuit 24, and multiple ( Figure 1 There are 5 switches in the middle (SW1~SW5) and multiple ( Figure 1 There are four diodes (D1 to D4). In addition, the backup power supply unit 2 also has multiple (… Figure 1 There are two input terminals T1 and T2 and one output terminal T3. That is to say, in the backup power system 1 according to this embodiment, the first auxiliary power supply 22 and the second auxiliary power supply 3 are provided separately.

[0034] (2.1) Terminal

[0035] The input terminal T1 is connected to the main power supply 4 via the ignition switch 8. The input terminal T1 is a terminal for inputting electric power supplied from the main power supply 4 to the backup power supply device 2 when the ignition switch 8 is on.

[0036] The input terminal T2 is connected to the 2nd auxiliary power supply 3. The input terminal T2 is a terminal for inputting electric power supplied from the 2nd auxiliary power supply 3 to the backup power supply device 2.

[0037] The output terminal T3 is connected to the brake system 5. The output terminal T3 is a terminal for outputting electric power supplied from the 1st auxiliary power supply 22 or the 2nd auxiliary power supply 3 to the brake system 5.

[0038] Further, for the brake system 5, the main power supply 4 is connected via the ignition switch 8. Therefore, the brake system 5 is also supplied with electric power from the main power supply 4 when the main power supply 4 is normal and the ignition switch 8 is on.

[0039] (2.2) Control circuit

[0040] The control circuit 21 includes, for example, a microcomputer having a processor and a memory. That is, the control circuit 21 is realized by a computer system having a processor and a memory. Further, the computer system functions as the control circuit 21 by executing an appropriate program by the processor. The program can be recorded in the memory in advance or provided through an electric communication line such as the Internet or a nonvolatile recording medium such as a memory card.

[0041] The control circuit 21 controls at least the drive circuit 24. Specifically, the control circuit 21 outputs 1st to 5th control signals for controlling the on / off of the switches SW1 to SW5 to the drive circuit 24. The drive circuit 24 controls the on / off of the switches SW1 to SW5 in accordance with the 1st to 5th control signals from the control circuit 21.

[0042] Further, the control circuit 21 has a function of diagnosing a failure with respect to the 2nd auxiliary power supply 3. Specifically, the control circuit 21 has a 1st function and a 2nd function. The 1st function is a function of determining whether the 2nd auxiliary power supply 3 is normal. The 2nd function is a function of determining whether the switches SW3 and SW4 provided in the 2nd power supply path 102 from the 2nd auxiliary power supply 3 to the brake system 5 are normal.

[0043] The control circuit 21 measures the voltage of the 1st midpoint Pl between the input terminal T2 connected to the 2nd auxiliary power supply 3 and the switch SW4 in the 1st function. If the voltage of the 1st midpoint Pl is 1st voltage or more, the control circuit 21 determines that the 2nd auxiliary power supply 3 is normal, and if the voltage of the 1st midpoint Pl is less than the 1st voltage, the control circuit 21 determines that the 2nd auxiliary power supply 3 is abnormal.

[0044] The control circuit 21, in the second function, measures the voltage of the second midpoint P2 between the switch SW3 and the switch SW4, thereby detecting a short circuit (short) and an open circuit (open) of the switches SW3, SW4.

[0045] (2.3) Auxiliary power supply

[0046] The first auxiliary power supply 22 and the second auxiliary power supply 3 are backup (i.e., auxiliary or standby) power supplies of the main power supply 4. In other words, the first auxiliary power supply 22 and the second auxiliary power supply 3 are auxiliary power supplies that can supply electric power to the first load 5 when the main power supply 4 fails.

[0047] The first auxiliary power supply 22 and the second auxiliary power supply 3 are each, for example, an electrical double layer capacitor (EDLC). In addition, the first auxiliary power supply 22 and the second auxiliary power supply 3 can each be a lithium ion capacitor (LIC), or a lithium ion battery (LIB) or the like. In the lithium ion capacitor, a positive electrode is formed of the same material as the EDLC (e.g., activated carbon), and a negative electrode is formed of the same material as the LIB (e.g., a carbon material such as graphite).

[0048] Furthermore, the first auxiliary power supply 22 and the second auxiliary power supply 3 are each not limited to an electrical double layer capacitor, and can be, for example, an electrochemical device having the structure described below. The electrochemical device referred to here has a positive electrode member, a negative electrode member, and a nonaqueous electrolyte solution. The positive electrode member has a positive electrode current collector and a positive electrode material layer supported on the positive electrode current collector and containing a positive electrode active material. The positive electrode material layer contains an electrically conductive polymer as a positive electrode active material that dopes and undopes anions (dopants). The negative electrode member has a negative electrode material layer containing a negative electrode active material. As an example, the negative electrode active material is a substance that promotes a redox reaction with the absorption and release of lithium ions, and is specifically a carbon material, a metal compound, an alloy, or a ceramic material, or the like. As an example, the nonaqueous electrolyte solution has lithium ion conductivity. Such a nonaqueous electrolyte solution contains a lithium salt and a nonaqueous solution in which the lithium salt is dissolved. The electrochemical device of this structure has a high energy density compared to an electrical double layer capacitor or the like.

[0049] Furthermore, the first auxiliary power supply 22 and the second auxiliary power supply 3 can each contain two or more electric storage devices (e.g., electrical double layer capacitors) connected in parallel, in series, or in parallel and in series electrically. That is, one first auxiliary power supply 22 and one second auxiliary power supply 3 can each be implemented by a parallel circuit or a series circuit of two or more electric storage devices, or a combination thereof.

[0050] In this embodiment, the second auxiliary power supply 3 has a smaller electrostatic capacity than the first auxiliary power supply 22. Therefore, in a case where the first auxiliary power supply 22 and the second auxiliary power supply 3 are simultaneously charged, the charging time of the second auxiliary power supply 3, i.e., the second time, is shorter than the charging time of the first auxiliary power supply 22, i.e., the first time. In other words, the second time until the second auxiliary power supply 3 becomes in a state capable of supplying electric power to the first load 5 is shorter than the first time until the first auxiliary power supply 22 becomes in a state capable of supplying electric power to the first load 5.

[0051] Further, in the emergency power supply system 1 of the present embodiment, the second auxiliary power supply 3 is configured to supply electric power to both the first load 5 and the second load 6. Therefore, the second auxiliary power supply 3 has a capacity (electrostatic) capable of supplying electric power to both the first load 5 and the second load 6.

[0052] Further, in the emergency power supply system 1 of the present embodiment, the first auxiliary power supply 22 and the second auxiliary power supply 3 are charged with electric power supplied from the main power supply 4. Specifically, if the ignition switch 8 is turned on and the switch SW5 is turned on, the first auxiliary power supply 22 is supplied with electric power from the main power supply 4 and is charged with the electric power. Further, if the ignition switch 8 is turned on, the second auxiliary power supply 3 is supplied with electric power from the main power supply 4 and is charged with the electric power. Further, the first auxiliary power supply 22 and the second auxiliary power supply 3 are configured to be discharged if the ignition switch 8 is turned off. Therefore, at the time of turning on the ignition switch 8 again, the first auxiliary power supply 22 and the second auxiliary power supply 3 are in a state of being not charged. The "state of being not charged" referred to in the present disclosure means a state of having a smaller amount of electric energy remaining than in a state of being fully charged, i.e., a state of sufficiently accumulating electric energy.

[0053] (2.4) Power supply circuit

[0054] The power supply circuit 23 is a circuit that generates an operating voltage of the control circuit 21. The power supply circuit 23 steps down the output voltage of the main power supply 4 input via the input terminal T1 and diodes D1, D3 to a given voltage (for example, 5 V) and outputs to the control circuit 21. Further, the power supply circuit 23 steps down the output voltage of the first auxiliary power supply 22 input via the diode D2 to a given voltage (for example, 5 V) and outputs to the control circuit 21. Further, the power supply circuit 23 steps down the output voltage of the second auxiliary power supply 3 input via the diode D4 to a given voltage (for example, 5 V) and outputs to the control circuit 21. The control circuit 21 can operate with the output power of the power supply circuit 23.

[0055] (2.5) Drive circuit

[0056] The drive circuit 24 is configured to individually control the plurality of switches SW1 to SW5. Specifically, the drive circuit 24 generates first to fifth drive signals for turning on / off the switches SW1 to SW5 in accordance with first to fifth control signals from the control circuit 21, and outputs the generated first to fifth drive signals to the switches SW1 to SW5. The switches SW1 to SW5 are turned on / off in accordance with the first to fifth drive signals from the drive circuit 24.

[0057] (2.6) Switches

[0058] The plurality of switches SW1 to SW5 are each, for example, an enhancement mode P-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The plurality of switches SW1 to SW5 are turned on / off in accordance with the first to fifth drive signals output from the drive circuit 24.

[0059] The switches SW1, SW2 are provided between the first auxiliary power supply 22 and the output terminal T3 in the first power supply path 101 that links the input terminal T1 and the output terminal T3. The switches SW1, SW2 are connected in series with each other in the first power supply path 101. The source of the switch SW1 is connected to the first auxiliary power supply 22, and the drain of the switch SW1 is connected to the drain of the switch SW2. Further, the source of the switch SW2 is connected to the output terminal T3. Also, by turning on both of the switches SW1, SW2, it is possible to supply the electric power accumulated in the first auxiliary power supply 22 to the brake system 5 via the switches SW1, SW2.

[0060] The switches SW3, SW4 are provided in the second power supply path 102 that links the input terminal T2 and the output terminal T3. The switches SW3, SW4 are connected in series with each other in the second power supply path 102. The source of the switch SW4 is connected to the input terminal T2, and the drain of the switch SW4 is connected to the drain of the switch SW3. Further, the source of the switch SW3 is connected to the output terminal T3. Also, by turning on both of the switches SW3, SW4, it is possible to supply the electric power accumulated in the second auxiliary power supply 3 to the brake system 5 via the switches SW3, SW4.

[0061] In this case, in the backup power supply system 1 according to the present embodiment, the configuration is such that electric power is supplied to the brake system 5 from one of the first auxiliary power supply 22 and the second auxiliary power supply 3. Therefore, in a case where the switches SW1 and SW2 are turned on and electric power is supplied to the brake system 5 from the first auxiliary power supply 22, the switches SW3 and SW4 are turned off and the supply of electric power from the second auxiliary power supply 3 is stopped. Further, in a case where the switches SW3 and SW4 are turned on and electric power is supplied to the brake system 5 from the second auxiliary power supply 3, the switches SW1 and SW2 are turned off and the supply of electric power from the first auxiliary power supply 22 is stopped.

[0062] In the backup power supply system 1 according to the present embodiment, the switching circuit 25 is configured by the switches SW1 to SW4 and the drive circuit 24. That is, the backup power supply system 1 according to the present embodiment further includes the switching circuit 25 that switches between a state in which the first auxiliary power supply 22 supplies electric power to the first load 5 and a state in which the second auxiliary power supply 3 supplies electric power to the first load 5.

[0063] The switch SW5 is provided between the input terminal T1 and the first auxiliary power supply 22 in the first power supply path 101 that links the input terminal T1 and the output terminal T3. The source of the switch SW5 is connected to the input terminal T1 via the diode D1, and the drain of the switch SW5 is connected to the first auxiliary power supply 22. In the backup power supply system 1 according to the present embodiment, the first auxiliary power supply 22 can be charged by turning on the ignition switch 8 and turning on the switch SW5. Therefore, even if the ignition switch 8 is turned on, if the switch SW5 is turned off, the first auxiliary power supply 22 is not charged.

[0064] (2.7) Diode

[0065] The diode D1 is provided between the input terminal T1 and the switch SW5 in the first power supply path 101 that links the input terminal T1 and the output terminal T3. The anode of the diode D1 is connected to the input terminal T1, and the cathode of the diode D1 is connected to the source of the switch SW5.

[0066] The diode D2 is provided between the first auxiliary power supply 22 and the power supply circuit 23. The anode of the diode D2 is connected to the first auxiliary power supply 22, and the cathode of the diode D2 is connected to the power supply circuit 23.

[0067] The diode D3 is provided between the connection point of the diode D1 and the switch SW5 and the power supply circuit 23. The anode of the diode D3 is connected to the connection point of the diode D1 and the switch SW5, and the cathode of the diode D3 is connected to the power supply circuit 23.

[0068] The diode D4 is provided between the input terminal T2 and the power supply circuit 23. The anode of the diode D4 is connected to the input terminal T2, and the cathode of the diode D4 is connected to the power supply circuit 23.

[0069] In this case, in a case where the output voltage of the main power supply 4 is higher than the output voltages of the first auxiliary power supply 22 and the second auxiliary power supply 3, the diodes D1, D3 are turned on, and the diodes D2, D4 become non-conducting, and the output voltage of the main power supply 4 is input to the power supply circuit 23 via the diodes D1, D3. Then, the power supply circuit 23 steps down the input output voltage of the main power supply 4 to a given voltage (for example, 5 V) and outputs to the control circuit 21.

[0070] Further, in a case where the output voltage of the first auxiliary power supply 22 is higher than the output voltages of the main power supply 4 and the second auxiliary power supply 3, the diode D2 is turned on, and the diodes D1, D3, D4 become non-conducting, and the output voltage of the first auxiliary power supply 22 is input to the power supply circuit 23 via the diode D2. Then, the power supply circuit 23 steps down the input output voltage of the first auxiliary power supply 22 to a given voltage (for example, 5 V) and outputs to the control circuit 21.

[0071] Further, in a case where the output voltage of the second auxiliary power supply 3 is higher than the output voltages of the main power supply 4 and the first auxiliary power supply 22, the diode D4 is turned on, and the diodes D1, D2, D3 become non-conducting, and the output voltage of the second auxiliary power supply 3 is input to the power supply circuit 23 via the diode D4. Then, the power supply circuit 23 steps down the input output voltage of the second auxiliary power supply 3 to a given voltage (for example, 5 V) and outputs to the control circuit 21.

[0072] (3) Operation

[0073] Next, the operation of the backup power supply system 1 according to the present embodiment will be described with reference to the flowchart of FIG. 6. Figure 3 and Figure 4 The operation of the backup power supply system 1 according to the present embodiment will be described.

[0074] (3.1) Operation Example 1

[0075] First, the operation of the backup power supply system 1 according to the present embodiment will be described with reference to the flowchart of FIG. 6. Figure 3 The operation of the backup power supply system 1 according to the present embodiment will be described. Hereinafter, the operation of supplying electric power from the main power supply 4 or the backup power supply system 1 to the first load 5 will be described. Further, hereinafter, it is assumed that the ignition switch 8 and the switch SW5 are turned on in advance and the operation will be described.

[0076] In a case where the main power supply 4 is not failed, that is, in a case where the main power supply 4 is normal (step S1: No), electric power is supplied from the main power supply 4 to the first load 5 (step S2). Here, the control circuit 21 is preferably configured to be able to determine whether the main power supply 4 is failed, for example, by measuring the output voltage of the main power supply 4.

[0077] In the event of a failure of the main power supply 4 (step S1: Yes), the control circuit 21 determines whether a first time has elapsed since the first auxiliary power supply 22 and the second auxiliary power supply 3 began charging (step S3). If the first time has elapsed (step S3: Yes), the control circuit 21 turns on switches SW1 and SW2 and turns off switches SW3 and SW4 to supply power from the first auxiliary power supply 22 to the first load 5 (step S4). On the other hand, if the first time has not elapsed (step S3: No), the control circuit 21 determines whether a second time has elapsed (step S5). In this case, since the first time has not elapsed, the first auxiliary power supply 22 has not been charged to a state where it can supply power to the first load 5.

[0078] If the second time period has elapsed (step S5: Yes), the control circuit 21 turns on switches SW3 and SW4 and turns off switches SW1 and SW2, thereby supplying power from the second auxiliary power supply 3 to the first load 5 (step S6). On the other hand, if the second time period has not elapsed (step S5: No), the control circuit 21 turns off switches SW1 to SW4, thereby preventing power from being supplied from either the first auxiliary power supply 22 or the second auxiliary power supply 3.

[0079] Furthermore, if a first time has elapsed while power is being supplied from the main power supply 4 to the first load 5, then in addition to power supply from the main power supply 4 to the first load 5, power can also be supplied from the first auxiliary power supply 22 to the first load 5. Moreover, if a second time has elapsed while power is being supplied from the main power supply 4 to the first load 5, then in addition to power supply from the main power supply 4 to the first load 5, power can also be supplied from the second auxiliary power supply 3 to the first load 5.

[0080] In the backup power system 1 according to this embodiment, the second time until the second auxiliary power supply 3 becomes capable of supplying power to the first load 5 is shorter than the first time until the first auxiliary power supply 22 becomes capable of supplying power to the first load 5. Therefore, during the period before the first time, power can be supplied to the first load 5 from the second auxiliary power supply 3. This has the advantage that, compared to the case where power is supplied to the first load 5 only by the first auxiliary power supply 22 when the main power supply 4 fails, it is less likely that the system will become unable to supply power to the first load 5 when the main power supply 4 fails.

[0081] (3.2) Action Example 2

[0082] Below, refer to Figure 4 Example 2 of the operation of backup power system 1 will be explained. Additionally, Figure 4 The "F1" in the output flag indicates the output status of the second auxiliary power supply 3. Figure 4"F2" in the "F2" is a request flag requesting output from the second auxiliary power supply 3. Further, Figure 4 "F3" in the "F3" is an allowance flag indicating whether or not remote parking is allowed, Figure 4 "F4" in the "F4" is a prohibition flag indicating whether or not remote parking is prohibited. Further, Figure 4 "F5" in the "F5" is a charge allowance flag indicating whether or not charging of the first auxiliary power supply 22 is allowed. Hereinafter, the description is made on the assumption that the main power supply 4 is not failed.

[0083] Hereinafter, the case where the vehicle 9 is automatically discharged from a parking lot by remote parking (remote control parking) is described as an example. In this case, in order to stop the vehicle 9 discharged from the parking lot, it is necessary to supply electric power to the brake system 5.

[0084] Here, during the remote parking, the vehicle 9 traveling at several km is stopped by the brake system 5, for example, and thus the consumed electric power of the brake system 5 is small as compared with the case where the vehicle 9 traveling at several tens of km is stopped. Thus, during the remote parking, the vehicle 9 can be stopped by the second auxiliary power supply 3 having a smaller electrostatic capacity than the first auxiliary power supply 22. On the other hand, in the case where the vehicle 9 traveling at several tens of km is stopped, electric power is supplied from the first auxiliary power supply 22 having a larger electrostatic capacity than the second auxiliary power supply 3 to the brake system 5. That is, in the backup power supply system 1 related to the present embodiment, the second auxiliary power supply 3 supplies electric power to the first load 5 in a second state where the consumed electric power of the first load 5 is smaller than the first state where the first auxiliary power supply 22 supplies electric power to the first load (brake system) 5.

[0085] The user (driver or passenger) of the vehicle 9 instructs the ECU 7 of the vehicle 9 to perform remote parking, for example, by using a dedicated remote controller. Here, in the case where the ECU 7 is not instructed to perform remote parking, the ignition switch 8 is turned off. Thus, in this case, electric power is not supplied from the main power supply 4 to the first auxiliary power supply 22 and the second auxiliary power supply 3, and the first auxiliary power supply 22 and the second auxiliary power supply 3 are not charged. Further, in the state where the ignition switch 8 is turned off, the electric power accumulated in the first auxiliary power supply 22 and the second auxiliary power supply 3 is discharged, and thus the first auxiliary power supply 22 and the second auxiliary power supply 3 are in an uncharged state.

[0086] If an instruction to remotely park the vehicle 9 is given to the ECU 7, the ECU 7 turns on the ignition switch 8 to start charging of the second auxiliary power supply 3. Further, if the ignition switch 8 is turned on, electric power is supplied from the main power supply 4 to the power supply circuit 23, and the control circuit 21 is activated by the output electric power of the power supply circuit 23. At this time, the permission flag F3 is made invalid (OFF), and remote parking cannot be performed. Further, at this time, the switches SW1 to SW5 are all turned off. In this state, the first auxiliary power supply 22 is not charged, and only the second auxiliary power supply 3 is charged. That is, the second auxiliary power supply 3 is charged with priority over the first auxiliary power supply 22 from the electric power supplied from the main power supply 4. Further, the ECU 7 outputs a request signal (specific signal) Sigl requesting implementation of remote parking to the control circuit 21. The control circuit 21, if receiving the request signal Sigl from the ECU 7, performs various processes shown below in order to perform remote parking. In the present embodiment, the ECU 7 of the vehicle 9 is an external system.

[0087] The control circuit 21 detects shorting of the switches SW2, SW3 before time tl. At this time, the control circuit 21 detects shorting of the switch SW2 by measuring the voltage of the third midpoint between the switches SW1, SW2 in a state where the switches SW1 to SW4 are turned off, and detects shorting of the switch SW3 by measuring the voltage of the second midpoint P2 between the switches SW3, SW4. Further, the control circuit 21 turns on the switch SW3 at time tl, and detects opening of the switch SW3 by measuring the voltage between the switches SW3, SW4. The control circuit 21 turns off the switch SW3 at time t2.

[0088] If the switch SW3 is not shorted and not opened, at time t2, the control circuit 21 makes the request flag F2 valid (ON). The control circuit 21 measures the voltage of the first midpoint Pl, and if the voltage is the first voltage or more, determines that electric power is output from the second auxiliary power supply 3. Then, the control circuit 21 makes the output flag Fl valid (refer to Figure 4 ). At this time, the switches SW3, SW4 are turned off, and therefore the output electric power of the second auxiliary power supply 3 is supplied to the shift-by-wire system 6 but is not supplied to the brake system 5.

[0089] The control circuit 21 detects shorting of the switch SW4 during a period from time t2 to time t3. In a state where the switches SW3, SW4 are turned off, the control circuit 21 detects shorting of the switch SW4 by measuring the voltage of the second midpoint P2 between the switches SW3, SW4. If the switch SW4 is not shorted, the control circuit 21 detects opening of the switch SW4 by turning on the switch SW4. The control circuit 21 detects opening of the switch SW4 by measuring the voltage of the second midpoint P2 between the switches SW3, SW4.

[0090] If the switch SW4 is not short-circuited and not open-circuited, the control circuit 21 turns on the switch SW3 at time t4. At this time, the control circuit 21 makes the request flag F2 invalid. Also, at this time, both the switches SW3 and SW4 are turned on, so the output power of the second auxiliary power supply 3 is supplied to both the brake system 5 and the shift-by-wire system 6.

[0091] Since the second auxiliary power supply 3 is in a state capable of supplying electric power to the brake system (first load) 5 and in a state capable of remote parking, the control circuit 21 makes the permission flag F3 valid and outputs a permission signal to the ECU 7. The ECU 7, if receiving the permission signal from the control circuit 21, transmits an operable signal indicating that remote parking is possible to the above-described remote controller. The user performs a specific operation (operation for implementing remote parking) to the above-described remote controller that has received the operable signal, thereby starting remote parking.

[0092] The control circuit 21 makes the charge permission flag F5 valid at time t5 and turns on the switch SW5 to start charging of the first auxiliary power supply 22.

[0093] The control circuit 21 makes the output flag Fl invalid at time t6 since the output voltage of the second auxiliary power supply 3 becomes lower than the first voltage. The control circuit 21 makes the permission flag F3 invalid at time t7 since the output voltage of the second auxiliary power supply 3 becomes lower than the first voltage and is not in a state capable of supplying electric power to the brake system 5. Also, the control circuit 21 makes the prohibition flag F4 valid at time t8 in accordance with the permission flag F3 changing from valid to invalid. The control circuit 21 turns off the switches SW3 and SW4 at time t9 and stops the supply of electric power from the second auxiliary power supply 3 to the brake system 5.

[0094] The control circuit 21 detects a short circuit of the switch SWl during a period from time t9 to time tio. The control circuit 21 detects the short circuit of the switch SWl by measuring the voltage of the third midpoint between the switches SWl and SW2 in a state where the switches SWl and SW2 are turned off. If the switches SWl and SW2 are not short-circuited, the control circuit 21 detects an open circuit of the switches SWl and SW2. The control circuit 21 turns on the switches SWl and SW2 at time tio and detects the open circuit of the switches SWl and SW2 by measuring the voltage of the third midpoint between the switches SWl and SW2.

[0095] The control circuit 21 turns off the switches SWl, SW2 and turns on the switches SW3, SW4 at the time tl l. Then, the control circuit 21 turns on the output flag Fl and turns on the permission flag F3 at the time tl 2 because the output voltage of the second auxiliary power supply 3 becomes the first voltage or more, and becomes a state in which the brake system 5 can be supplied with electric power.

[0096] The control circuit 21 turns off the switches SW3, SW4 at the time tl 3 in order to stop the supply of electric power from the second auxiliary power supply 3 to the brake system 5 because the charging of the first auxiliary power supply 22 is completed. Thus, the supply of electric power from the second auxiliary power supply 3 to the brake system 5 can be stopped. Then, the control circuit 21 turns on the switches SWl, SW2 at the time tl 3 or later because the first auxiliary power supply 22 becomes a state in which the brake system 5 can be supplied with electric power, and thus electric power is supplied from the first auxiliary power supply 22 to the brake system 5.

[0097] In the present embodiment, in the backup power supply system 1, during the period from the time t4 to the time t6 and the period from the time tl 2 to the time tl 3 in which the switches SW3, SW4 are on and the output flag Fl is on, remote parking can be performed by electric power from the second auxiliary power supply 3.

[0098] In the backup power supply system 1 according to the present embodiment, the second time until the second auxiliary power supply 3 becomes a state in which the first load 5 can be supplied with electric power is shorter than the first time until the first auxiliary power supply 22 becomes a state in which the first load 5 can be supplied with electric power. Thus, during the period before the first time elapses, electric power can be supplied from the second auxiliary power supply 3 to the first load 5. Thus, it is possible to have an advantage that, when the main power supply 4 fails, it is less likely to become a state in which electric power is not supplied to the first load 5 compared to a case in which only the first auxiliary power supply 22 supplies electric power to the first load 5 when the main power supply 4 fails.

[0099] Further, as in the backup power supply system 1 according to the present embodiment, by preferentially charging the second auxiliary power supply 3, it is possible to shorten the charging time of the second auxiliary power supply 3 compared to a case in which the first auxiliary power supply 22 and the second auxiliary power supply 3 are charged at the same time.

[0100] Further, in the backup power supply system 1 according to the embodiment, the control circuit 21 outputs, in a case where the request signal (specific signal) Sigl input from the ECU 7 as an external system is received, that the second auxiliary power supply 3 is in a power supply-possible state, that is, outputs the above-described permission signal, to the ECU 7 if the second auxiliary power supply 3 is in a power supply-possible state with respect to the first load 5. In particular, in a case where the engine of the vehicle 9 is started before remote parking is instructed by the above-described remote controller, the second auxiliary power supply 3 can be charged during a period from when the engine of the vehicle 9 is started to when remote parking is instructed. Thus, the first load 5 can be started to be supplied with power at an earlier timing than in a case where the second auxiliary power supply 3 is made to be in a power supply-possible state after the request signal Sigl from the ECU 7 is received. The "power supply-possible state" according to the present disclosure includes that the second auxiliary power supply 3 is charged and can supply the first load 5 with power from the second auxiliary power supply 3, and that the second auxiliary power supply 3 is normal and the switches SW3 and SW4 are normal (the second power supply path 102 from the second auxiliary power supply 3 to the first load 5 is normal).

[0101] (4) Modification

[0102] The above-described embodiment is only one of various embodiments of the present disclosure. The above-described embodiment can be changed in various ways according to design and the like as long as the object of the present disclosure is achieved. Further, the same functions as those of the backup power supply system 1 according to the above-described embodiment can be achieved by a power supply backup method, a computer program, or a nonvolatile recording medium in which a computer program is recorded.

[0103] The power supply backup method according to one embodiment is a power supply backup method used for the backup power supply system 1. The backup power supply system 1 includes the first auxiliary power supply 22 and the second auxiliary power supply 3 that can supply the first load (load) 5 with power when the main power supply 4 fails. In the power supply backup method, the second time is shorter than the first time. The first time is a time until the first auxiliary power supply 22 becomes in a state where the first load 5 can be supplied with power. The second time is a time until the second auxiliary power supply 3 becomes in a state where the first load 5 can be supplied with power. The program according to one embodiment is a program for causing one or more processors to execute the above-described power supply backup method.

[0104] Hereinafter, modifications of the above-described embodiment will be described. The modifications described below can be appropriately combined and applied.

[0105] In the backup power supply system 1 in the present disclosure, the control circuit 21 includes a computer system. The computer system has a processor as hardware and a memory as a main structure. By the processor executing a program recorded in the memory of the computer system, the functions of the control circuit 21 in the present disclosure are realized. The program can be recorded in advance in the memory of the computer system, can be provided through an electric communication line, or can be recorded in a nonvolatile recording medium such as a memory card, an optical disk, or a hard disk drive that is readable by the computer system. The processor of the computer system can be constituted by one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuit referred to as an IC or an LSI herein varies in name depending on the degree of integration and includes an integrated circuit referred to as a system LSI, a very large scale integration (VLSI), or an ultra large scale integration (ULSI). Further, a field-programmable gate array (FPGA) that is programmable after the LSI is manufactured or a logic device that enables reconfiguration of the connection relationship within the LSI or reconfiguration of the circuit division within the LSI can also be employed as the processor. The plurality of electronic circuits can be integrated in one chip or can be provided separately in a plurality of chips. The plurality of chips can be integrated in one device or can be provided separately in a plurality of devices. The computer system herein includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller can also be constituted by one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

[0106] Further, it is not essential for the backup power supply system 1 to have the plurality of functions integrated in one housing. That is, the structural elements of the backup power supply system 1 can be provided separately in a plurality of housings. Further, at least a part of the functions of the backup power supply system 1, such as the function of the control circuit 21, can be realized by a cloud (cloud computing) or the like.

[0107] (4.1) Modification 1

[0108] In the above-described embodiment, the first auxiliary power supply 22 and the second auxiliary power supply 3 are provided separately, but as shown in FIG. 4, the second auxiliary power supply 3A can be included in the first auxiliary power supply 22A. That is, the second auxiliary power supply 3A can be constituted by a part of the first auxiliary power supply 22A. Hereinafter, the backup power supply system 1A related to Modification 1 will be described with reference to FIG. 4. Figure 5 Figure 5 The backup power supply system 1A related to Modification 1 will be described. For the same structures as those of the backup power supply system 1 related to the above-described embodiment, the same reference numerals are assigned and the description is omitted.​

[0109] As Figure 4 shown in FIG. 1, the backup power system 1 according to the embodiment includes a backup power device 2, a main power source 4, a first auxiliary power source 22, a second auxiliary power source 3, and a first load 5.

[0110] The backup power device 2 includes a control circuit 21, the first auxiliary power source 22, a power supply circuit 23, a drive circuit 24, a plurality of (five in this embodiment) switches SW1 to SW5, and a plurality of (four in this embodiment) diodes D1 to D4. In addition, the backup power device 2 includes a plurality of (two in this embodiment) input terminals T1, T2, and one output terminal T3. The backup power device 2 further includes a first auxiliary power source 22. Figure 5 Figure 5 Figure 5

[0111] The first auxiliary power source 22 has, for example, a series circuit in which five electric double layer capacitors are connected in series between the first power supply path 101 and the ground. Among the five electric double layer capacitors that constitute the first auxiliary power source 22, the second auxiliary power source 3 is constituted by the electric double layer capacitor connected closest to the ground. That is, in the backup power system 1 according to the embodiment, the first auxiliary power source 22 includes the second auxiliary power source 3. In the first auxiliary power source 22, among the five electric double layer capacitors, charging is performed in order from the electric double layer capacitor connected closest to the ground, and thus the second auxiliary power source 3 can be preferentially charged.

[0112] In the backup power system 1 according to the embodiment, as described above, the second auxiliary power source 3 is preferentially charged. Thus, even during a period until the first auxiliary power source 22 is charged, the first load 5 can be supplied with electric power by the second auxiliary power source 3. Therefore, it is possible to avoid a state in which the first load 5 is not supplied with electric power at the time of failure of the main power source 4, compared with a case in which the first load 5 is supplied with electric power only by the first auxiliary power source 22 at the time of failure of the main power source 4.

[0113] (4.2) Other Modified Examples

[0114] Hereinafter, other modified examples of the above-described embodiment will be described.

[0115] In the above-described embodiment, the second auxiliary power source 3 is preferentially charged than the first auxiliary power source 22 by electric power supplied from the main power source 4, but the first auxiliary power source 22 and the second auxiliary power source 3 can be simultaneously charged. In this case, for example, the switches SW5 are turned on at a timing at which the control circuit 21 is activated, and thus the first auxiliary power source 22 and the second auxiliary power source 3 can be simultaneously charged.

[0116] ​​​In the above-described embodiment, the state in which the first auxiliary power supply 22 supplies electric power to the first load 5 and the state in which the second auxiliary power supply 3 supplies electric power to the first load 5 are switched by the switching circuit 25. In contrast to this, it is also possible to configure so as to supply electric power to the first load 5 from both the first auxiliary power supply 22 and the second auxiliary power supply 3.

[0117] In the above-described embodiment, the second load is the shift-by-wire system 6, but the second load is not limited to the shift-by-wire system 6, and for example, can be a door lock system that locks a door of the vehicle 9.

[0118] In the above-described embodiment, a case in which remote parking is performed using a remote controller is exemplified, but for example, remote parking can be performed using a smartphone, a tablet, or the like on which a dedicated application is downloaded.

[0119] In the above-described embodiment, in a case in which the control circuit 21 receives the request signal Sig1 from the ECU 7, if the second auxiliary power supply 3 is in the state in which electric power can be supplied, the ECU 7 is outputted that the second auxiliary power supply 3 is in the state in which electric power can be supplied. In contrast to this, it is also possible to cause the second auxiliary power supply 3 to be in the state in which electric power can be supplied to the first load 5 after receiving the request signal Sig1 from the ECU 7. Thus, it is possible to cause the second auxiliary power supply 3 to be in the state in which electric power can be supplied in accordance with the request signal Sig1 from the ECU 7.

[0120] (SUMMARY)

[0121] As described above, the backup power supply system (1; 1A) according to the first aspect includes the first auxiliary power supply (22; 22A) and the second auxiliary power supply (3; 3A). The first auxiliary power supply (22; 22A) is configured to supply electric power to the load (5) in a case in which the main power supply (4) is disabled. The second auxiliary power supply (3; 3A) is configured to supply electric power to the load (5) in a case in which the main power supply (4) is disabled. The first time is a time until the first auxiliary power supply (22; 22A) becomes in a state in which electric power can be supplied to the load (5). The second time is a time until the second auxiliary power supply (3; 3A) becomes in a state in which electric power can be supplied to the load (5). The second time is shorter than the first time.

[0122] According to the first aspect, before the first auxiliary power supply (22; 22A) becomes in the state in which electric power can be supplied to the load (5), it is possible to supply electric power to the load (5) by the second auxiliary power supply (3; 3A). Thus, it is possible to have an advantage that, in a case in which the main power supply (4) is disabled, it is less likely to become in a state in which electric power is not supplied to the load (5) compared to a case in which only the first auxiliary power supply (22; 22A) supplies electric power to the load (5) in a case in which the main power supply (4) is disabled.

[0123] In the backup power supply system (1; 1A) according to the second aspect, in the first aspect, the first auxiliary power supply (22; 22A) and the second auxiliary power supply (3; 3A) are charged with electric power supplied from the main power supply (4).

[0124] According to this aspect, the first auxiliary power supply (22; 22A) and the second auxiliary power supply (3; 3A) can be charged by the electric power supplied from the main power supply (4).

[0125] In the backup power supply system (1; 1A) according to the third aspect, the capacity of the second auxiliary power supply (3; 3A) is smaller than the capacity of the first auxiliary power supply (22; 22A) in the first aspect or the second aspect.

[0126] According to this aspect, even when the first auxiliary power supply (22; 22A) and the second auxiliary power supply (3; 3A) are charged at the same time, the second auxiliary power supply (3; 3A) can be charged in a shorter time than the first auxiliary power supply (22; 22A).

[0127] In the backup power supply system (1; 1A) according to the fourth aspect, the second auxiliary power supply (3; 3A) is preferentially charged by the electric power supplied from the main power supply (4) in any one of the first aspect to the third aspect.

[0128] According to this aspect, the second auxiliary power supply (3; 3A) can be charged in a shorter time than when the first auxiliary power supply (22; 22A) and the second auxiliary power supply (3; 3A) are charged at the same time.

[0129] In the backup power supply system (1A) according to the fifth aspect, the first auxiliary power supply (22A) includes the second auxiliary power supply (3A) in any one of the first aspect to the fourth aspect.

[0130] According to this aspect, the second auxiliary power supply (3A) can be omitted, and the backup power supply system (1A) can be prevented from being upsized.

[0131] The backup power supply system (1; 1A) according to the sixth aspect is mounted on a vehicle (9) provided with a main power supply (4) and a load (5) in any one of the first aspect to the fifth aspect.

[0132] According to this aspect, it is difficult to become a state in which the load (5) provided on the vehicle (9) is not supplied with electric power at the time of failure of the main power supply (4).

[0133] In the backup power supply system (1; 1A) according to the seventh aspect, the second auxiliary power supply (3; 3A) can supply electric power to both the first load (5) as a load and a second load (6) different from the first load (5) in any one of the first aspect to the sixth aspect.

[0134] According to this mode, it is possible to supply electric power to both the first load (5) and the second load (6) when the main power supply (4) fails.

[0135] In the backup power supply system (1; 1A) according to the eighth mode, the second auxiliary power supply (3; 3A) has a capacity capable of supplying electric power to both the first load (5) and the second load (6) in the seventh mode.

[0136] According to this mode, it is possible to supply electric power to both the first load (5) and the second load (6) when the main power supply (4) fails.

[0137] In the backup power supply system (1; 1A) according to the ninth mode, the second auxiliary power supply (3; 3A) supplies electric power to the load (5) in the second state in any one of the first mode through the eighth mode. In the second state, the consumed electric power of the load (5) is smaller than in the first state in which the first auxiliary power supply (22; 22A) supplies electric power to the load (5).

[0138] According to this mode, it is possible to operate the load (5) by the electric power supplied from the second auxiliary power supply (3; 3A) in the second state.

[0139] The backup power supply system (1; 1A) according to the tenth mode further includes a switching circuit (25) in any one of the first mode through the ninth mode. The switching circuit (25) switches between a state in which the first auxiliary power supply (22; 22A) supplies electric power to the load (5) and a state in which the second auxiliary power supply (3; 3A) supplies electric power to the load (5).

[0140] According to this mode, it is possible to switch between a state in which the first auxiliary power supply (22; 22A) supplies electric power to the load (5) and a state in which the second auxiliary power supply (3; 3A) supplies electric power to the load (5).

[0141] The backup power supply system (1; 1A) according to the eleventh mode, in any one of the first mode through the tenth mode, in a case where a specific signal (Sigl) from an external system (7) is received, if the second auxiliary power supply (3; 3A) is in a power supply enabled state, outputs to the external system (13) that the second auxiliary power supply (3; 3A) is in the power supply enabled state. The power supply enabled state is a state in which the second auxiliary power supply (3; 3A) is capable of supplying electric power to the load (5).

[0142] According to this mode, it is possible to start supplying electric power to the load (5) at an earlier timing than in a case where the second auxiliary power supply (3; 3A) is made in the power supply enabled state after the specific signal (Sigl) from the external system (7) is received.

[0143] In the backup power supply system (1; 1A) according to the 12th aspect, in any one of the 1st to 10th aspects, the 2nd auxiliary power supply (3; 3A) is brought to a state in which the load (5) can be supplied with electric power after receiving a specific signal (Sig1) input from an external system (7).

[0144] According to this aspect, the 2nd auxiliary power supply (3; 3A) can be brought to a state in which the load (5) can be supplied with electric power in accordance with a specific signal (Sig1) input from an external system (7).

[0145] The backup power supply system (1; 1A) according to the 13th aspect has a function of diagnosing a failure related to the 2nd auxiliary power supply (3; 3A) in any one of the 1st to 12th aspects.

[0146] According to this aspect, a failure related to the 2nd auxiliary power supply (3; 3A) can be diagnosed.

[0147] The power backup method according to the 14th aspect is a power backup method for a backup power supply system (1; 1A). The backup power supply system (1; 1A) has a 1st auxiliary power supply (22; 22A) and a 2nd auxiliary power supply (3; 3A) that can supply a load (5) with electric power when a main power supply (4) fails. In the power backup method, a 2nd time is shorter than a 1st time. The 1st time is a time until the 1st auxiliary power supply (22; 22A) becomes a state in which the load (5) can be supplied with electric power. The 2nd time is a time until the 2nd auxiliary power supply (3; 3A) becomes a state in which the load (5) can be supplied with electric power.

[0148] According to this aspect, the load (5) can be supplied with electric power by the 2nd auxiliary power supply (3; 3A) before the 1st auxiliary power supply (22; 22A) becomes a state in which the load (5) can be supplied with electric power. Thus, there is an advantage that it is less likely to become a state in which the load (5) is not supplied with electric power when the main power supply (4) fails, as compared with a case where the load (5) is supplied with electric power by only the 1st auxiliary power supply (22; 22A) when the main power supply (4) fails.

[0149] The program according to the 15th aspect is a program for causing one or more processors to execute the power backup method according to the 14th aspect.

[0150] According to this aspect, the load (5) can be supplied with electric power by the 2nd auxiliary power supply (3; 3A) before the 1st auxiliary power supply (22; 22A) becomes a state in which the load (5) can be supplied with electric power. Thus, there is an advantage that it is less likely to become a state in which the load (5) is not supplied with electric power when the main power supply (4) fails, as compared with a case where the load (5) is supplied with electric power by only the 1st auxiliary power supply (22; 22A) when the main power supply (4) fails.

[0151] As for the structures related to the modes 2 to 13, structures not necessary for the backup power supply system (1; 1A) can be appropriately omitted.

[0152] Symbol explanation

[0153] 1, 1A backup power supply system;

[0154] 3, 3A second auxiliary power supply;

[0155] 4 main power supply;

[0156] 5 first load (load);

[0157] 6 second load;

[0158] 7 ECU (external system);

[0159] 9 vehicle;

[0160] 22, 22A first auxiliary power supply;

[0161] 25 switching circuit;

[0162] Sig1 request signal (specific signal).

Claims

1. A backup power supply system provided with a first auxiliary power supply and a second auxiliary power supply that are able to supply electric power to a load when a main power supply fails, a second time until the second auxiliary power supply becomes in a state able to supply electric power to the load is shorter than a first time until the first auxiliary power supply becomes in a state able to supply electric power to the load, the first auxiliary power supply is not charged, the second auxiliary power supply is charged, and then, in a second state in which the load consumes less electric power than in a first state in which the first auxiliary power supply supplies electric power to the load, the second auxiliary power supply supplies electric power to the load, charging of the first auxiliary power supply is started during a period in which the second auxiliary power supply is in a state able to supply electric power to the load in the second state, the first auxiliary power supply supplies electric power to the load in the first state.

2. The backup power supply system according to claim 1, wherein the first auxiliary power supply and the second auxiliary power supply are charged by electric power supplied from the main power supply.

3. The backup power supply system according to claim 1 or 2, wherein a capacity of the second auxiliary power supply is smaller than a capacity of the first auxiliary power supply.

4. The backup power supply system according to claim 1 or 2, wherein the first auxiliary power supply includes the second auxiliary power supply.

5. The backup power supply system according to claim 1 or 2, wherein the backup power supply system is mounted on a vehicle provided with the main power supply and the load.

6. The backup power supply system according to claim 1 or 2, wherein the second auxiliary power supply is able to supply electric power to both a first load and a second load that are different from the first load, as the load.

7. The backup power supply system according to claim 6, wherein the second auxiliary power supply has a capacity that is at least able to supply electric power to both the first load and the second load.

8. The backup power supply system according to claim 1 or 2, wherein the backup power supply system is further provided with a switching circuit that switches between a state in which the first auxiliary power supply supplies electric power to the load and a state in which the second auxiliary power supply supplies electric power to the load.

9. The backup power supply system according to claim 1 or 2, wherein in a case where a specific signal input from an external system is received, if the second auxiliary power supply is in a power supplyable state in which the second auxiliary power supply is able to supply electric power to the load, it is output to the external system that the second auxiliary power supply is in the power supplyable state.

10. The backup power supply system according to claim 1 or 2, wherein after a specific signal input from an external system is received, the second auxiliary power supply is made to be in a state in which the second auxiliary power supply is able to supply electric power to the load.

11. The backup power supply system according to claim 1 or 2, wherein the backup power supply system has a function of diagnosing a failure related to the second auxiliary power supply.

12. The backup power supply system according to claim 1 or 2, wherein the first time is a time from when the first auxiliary power supply is charged to when the first auxiliary power supply becomes in a state able to supply electric power to the load, The second time is a time from when the second auxiliary power supply starts to be charged until the second auxiliary power supply becomes in a state capable of supplying electric power to the load.

13. A power backup method used for a backup power system having a first auxiliary power supply and a second auxiliary power supply capable of supplying electric power to a load, The power backup method includes: a step of supplying electric power to the load by a main power supply when the main power supply is not failed; a step of supplying electric power to the load by the backup power system when the main power supply is failed; a step of not charging the first auxiliary power supply and charging the second auxiliary power supply; a step of supplying electric power to the load by the second auxiliary power supply in a second state in which a consumed electric power of the load is smaller than a first state in which the first auxiliary power supply supplies electric power to the load, after the step of not charging the first auxiliary power supply and charging the second auxiliary power supply; a step of starting charging of the first auxiliary power supply during a period in which the second auxiliary power supply is in a state capable of supplying electric power to the load in the second state; and a step of supplying electric power to the load by the first auxiliary power supply in the first state, a second time until the second auxiliary power supply becomes in a state capable of supplying electric power to the load is shorter than a first time until the first auxiliary power supply becomes in a state capable of supplying electric power to the load.

14. The power backup method according to claim 13, wherein the first time is a time from when the first auxiliary power supply starts to be charged until the first auxiliary power supply becomes in a state capable of supplying electric power to the load, the second time is a time from when the second auxiliary power supply starts to be charged until the second auxiliary power supply becomes in a state capable of supplying electric power to the load.

15. The power backup method according to claim 13 or 14, wherein the power backup method further includes a step of judging whether the main power supply is failed.

16. The power backup method according to claim 13 or 14, wherein the step of supplying electric power to the load by the backup power system when the main power supply is failed includes: a step of supplying electric power to the load by the first auxiliary power supply when the main power supply is failed if the first time elapses from when the first auxiliary power supply starts to be charged; and a step of supplying electric power to the load by the second auxiliary power supply when the main power supply is failed if the second time elapses from when the second auxiliary power supply starts to be charged without the first time elapsing from when the first auxiliary power supply starts to be charged.

17. The power backup method according to claim 16, wherein the power backup method further includes: a step of not supplying electric power to the load by the backup power system when the main power supply is failed if neither the first time elapses from when the first auxiliary power supply starts to be charged nor the second time elapses from when the second auxiliary power supply starts to be charged.

18. The power backup method according to claim 13 or 14, wherein the step of the main power supply supplying power to the load when the main power supply is not failed includes a step of the backup power supply system not supplying power to the load and the main power supply supplying power to the load when the main power supply is not failed, the step of the backup power supply system supplying power to the load when the main power supply is failed includes a step of the main power supply not supplying power to the load and the backup power supply system supplying power to the load when the main power supply is failed.

19. A program product comprising a program for causing one or more processors to execute the power backup method according to any one of claims 13 to 18.

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