Backup power supply system, moving body, control method for backup power supply system, and program

Abstract

The standby power supply system is connected between a power supply and a load. A backup power supply system includes a first port, a second port, a conductive path, a power storage unit, a charging circuit, a discharging circuit, a switch, and a control circuit. The first port is connected with a power supply. And the second port is connected with a load. The conductive path connects the first port and the second port. The charging circuit is provided in a first path that connects the conductive path and the power storage unit. The discharge circuit is provided in a second path that connects the conductive path and the power storage unit. The switch is provided between the first port and the charging circuit, is a conductive path between the first port and the discharging circuit, and conducts and cuts off the conductive path. The control circuit controls the switch, the charging circuit and the discharging circuit.

Description

Technical Field

[0001] The present disclosure relates to a backup power supply system, a mobile object, a control method for the backup power supply system, and a program. More specifically, the present disclosure relates to a backup power supply system for supplying power to a load when a power supply fails, a mobile object having the backup power supply system, and a control method for the backup power supply system and a program. Background Art

[0002] The charging device described in Patent Document 1 includes a secondary battery (power source), a charging circuit, a discharging circuit, a double-layer capacitor (power storage unit), a load driving circuit, and a load. The load driving circuit is provided in a conductive path connecting the secondary battery and the load. The charging circuit is provided between the secondary battery and the load driving circuit in the conductive path. The discharging circuit is connected in parallel with the charging circuit. The double-layer capacitor is connected between a branch point between the charging circuit and the load and a ground line in the conductive path.

[0003] In this charging device, in order to extend the life of the double-layer capacitor, the stored power of the double-layer capacitor is discharged (charged) to the secondary battery via a discharge circuit. At this time, the output voltage of the double-layer capacitor is also supplied to the load from the above-mentioned conductive path via the load drive circuit without passing through the discharge circuit.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-171694 Summary of the invention

[0007] In the charging device described in Patent Document 1, the voltage supplied from the double-layer capacitor to the load is supplied to the load without passing through a discharge circuit, so the voltage decreases as the double-layer capacitor is discharged. Therefore, during the discharge of the double-layer capacitor, the output voltage of the double-layer capacitor decreases and becomes lower than the voltage required by the load, and the load cannot be operated by the output voltage of the double-layer capacitor.

[0008] A backup power supply system of one embodiment of the present disclosure is connected between a power supply and a load. The backup power supply system includes a first port, a second port, a conductive path, a storage unit, a charging circuit, a discharging circuit, a switch, and a control circuit. The first port is connected to the power supply. The second port is connected to the load. The conductive path connects the first port and the second port. The charging circuit is provided in a first path connecting the conductive path and the storage unit, and charges the power from the conductive path to the storage unit. The discharging circuit is provided in a second path connecting the conductive path and the storage unit, and discharges the stored power of the storage unit to the conductive path. The switch is provided between the first port and the charging circuit and is the conductive path between the first port and the discharging circuit, and turns on and off the conductive path. The control circuit controls the switch, the charging circuit, and the discharging circuit.

[0009] A mobile object according to one aspect of the present disclosure includes the backup power supply system, the power supply, the load, and a mobile object body. The mobile object body is provided with the backup power supply system, the power supply, and the load.

[0010] A control method for a backup power supply system according to one embodiment of the present disclosure is a control method for a backup power supply system connected between a power supply and a load. The backup power supply system comprises a first port, a second port, a conductive path, a power storage unit, a charging circuit, a discharging circuit, and a switch. The first port is connected to the power supply. The second port is connected to the load. The conductive path connects the first port and the second port. The charging circuit is provided in a first path connecting the conductive path and the power storage unit, and charges the power from the conductive path to the power storage unit. The discharging circuit is provided in a second path connecting the conductive path and the power storage unit, and discharges the stored power of the power storage unit to the conductive path. The switch is provided between the first port and the charging circuit and is the conductive path between the first port and the discharging circuit, and turns on and off the conductive path. The control method for the backup power supply system comprises a control process of controlling the switch, the charging circuit, and the discharging circuit by a control circuit. In the control step, when discharging the stored power of the storage unit, the stored power of the storage unit is discharged to the conductive path via the discharge circuit while the charging circuit is stopped, thereby charging the power supply and supplying the power to the load.

[0011] A program according to one aspect of the present disclosure causes one or more processors to execute the control method of the backup power supply system.

[0012] According to the present disclosure, there is an effect that the load can be operated by the discharge of the power storage unit even during the discharge of the power storage unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a block diagram of a backup power supply system according to an embodiment.

[0014] Figure 2 This is a side view of a portion of a vehicle having the same backup power system as above, which is cut away.

[0015] Figure 3 It is an explanatory diagram for explaining the operation of the backup power supply system in the first mode.

[0016] Figure 4 It is an explanatory diagram for explaining the operation of the backup power supply system in the second mode.

[0017] Figure 5 It is an explanatory diagram for explaining the operation of the backup power supply system in the third mode.

[0018] Figure 6 It is an explanatory diagram for explaining the operation of the backup power supply system in the fourth mode.

[0019] Figure 7 It is a flowchart explaining the operation of the backup power supply system as above.

[0020] Figure 8 This is a block diagram of a backup power supply system according to Modification 3. DETAILED DESCRIPTION

[0021] (1) Implementation Method

[0022] (1-1)Overview

[0023] The backup power supply system 1 of this embodiment is described with reference to the drawings. The structure described in this embodiment is only an example of the present disclosure. The present disclosure is not limited to this embodiment, and various changes can be made according to the design, etc. as long as they do not depart from the scope of the technical concept of the present disclosure.

[0024] like Figure 1 As shown, the backup power supply system 1 is provided in, for example, a vehicle 100 (see Figure 2 ), when the power source 2 is normal, the output voltage of the power source 2 is supplied to the load 3, and when the power source 2 fails, the power storage unit 5 is used to supply power to the load 3 instead of the power source 2. Thus, even when the power source 2 fails, the load 3 can continue to operate by supplying power from the power storage unit 5. Here, "power source 2 failure" means that the power supply from the power source 2 to the load 3 stops due to a fault, degradation, or disconnection of the power source 2.

[0025] In this way, the backup power supply system 1 is mounted on the vehicle 100 having the power supply 2 and the load 3. That is, the vehicle 100 (mobile body) has the vehicle body 101 (mobile body body), the power supply 2, the load 3, and the backup power supply system 1. The power supply 2, the load 3, and the backup power supply system 1 are arranged in the vehicle 100. In addition, in the present embodiment, the case where the backup power supply system 1 is provided in the vehicle 100 is illustrated, but the backup power supply system 1 may also be provided in a mobile body other than the vehicle 100 (for example, an airplane, a ship, or a train).

[0026] The power source 2 is a power source provided in the vehicle 100 and can be used to supply power to the load 3 , and is, for example, a battery.

[0027] The load 3 is a load (e.g., equipment) provided by the vehicle 100, and is, for example, a load that is always in operation when powered by the power supply 2. The load 3 may be, for example, a shift-by-wire system, a door locking / unlocking device, or a braking system. The shift-by-wire system electrically switches the shift position of the automatic transmission based on the position of the shift lever. The door locking / unlocking system is a system that electrically switches the locking and unlocking of the doors of the vehicle 100. The braking system electrically activates the braking mechanism provided on each wheel of the vehicle 100.

[0028] (1-2) Detailed description of the backup power system

[0029] like Figure 1 As shown, the backup power supply system 1 includes a first port P1, a second port P2, a circuit 4, a switch SW, a storage unit 5, a charging circuit 6, a discharging circuit 7, a voltage measuring circuit 8, and a control circuit 9. The storage unit 5 may not be included in the components of the backup power supply system 1.

[0030] (1-2-1) First port and second port

[0031] The first port P1 is an input / output port that can be connected to the positive electrode of the power supply 2 via the wiring 10. The negative electrode of the power supply 2 is connected to a ground line 44 described later. The first port P1 inputs the output voltage of the power supply 2 via the wiring 10, or outputs the output voltage of the power storage unit 5 to the power supply 2 via the wiring 10.

[0032] The second port P2 is an output port that can be connected to one end of the load 3 via the wiring 11. The other end of the load 3 is connected to a ground line 44 described later. The second port P2 supplies the output voltage of the power supply 2 or the output voltage of the power storage unit 5 to the load 3 via the wiring 11. The wirings 10 and 11 are formed of, for example, a harness.

[0033] (1-2-2) Circuit

[0034] The circuit 4 is a circuit for transmitting the output voltage of the power supply 2 from the first port P1 to the power storage unit 5 and the second port P2, or transmitting the output voltage of the power storage unit 5 to the first port P1 and the second port P2. The circuit 4 includes a conductive path 41 as a main circuit, a charging path 42 (first path), a discharge circuit 43 (second path), and a ground line 44.

[0035] The conductive path 41 is a circuit (power line) connecting the first port P1 and the second port P2. The conductive path 41 transfers the output voltage of the power supply 2 from the first port P1 to the second port P2, or transfers the output voltage (discharge voltage) of the discharge circuit 7 output (discharged) to the conductive path 41 to the first port P1 and the second port P2.

[0036] The charging path 42 is a circuit provided with the charging circuit 6 , and connects the branch point N1 of the conductive path 41 to a first end 5 a (described later) of the power storage unit 5 . The charging path 42 inputs the voltage of the conductive path 41 to the power storage unit 5 via the charging circuit 6 .

[0037] The discharge circuit 43 is a circuit provided with a discharge circuit 7, and connects a branch point N2 of the conductive path 41 to a first end 5a of the power storage unit 5 described later. The branch point N1 is arranged at a position closer to the first port P1 than the branch point N2 in the conductive path 41. The discharge circuit 43 discharges the output voltage (discharge voltage) of the power storage unit 5 to the conductive path 41 via the discharge circuit 7.

[0038] The grounding line 44 is a circuit maintained at a ground potential and is connected to the ground line. The grounding line 44 is connected to the negative electrode of the power source 2 , the second end 5 b of the power storage unit 5 , and the other end of the load 3 .

[0039] (1-2-3) Power storage unit

[0040] The power storage unit 5 is a power supply for backup (i.e., auxiliary or standby) of the power supply 2. In other words, the power storage unit 5 is a power supply that can supply power (voltage and current) to the load 3 when the power supply 2 fails. The power storage unit 5 is, for example, an electrical double layer capacitor (EDLC). The power storage unit 5 may also be composed of two or more power storage devices (e.g., electrical double layer capacitors) electrically connected in parallel, in series, or in parallel and in series. That is, the power storage unit 5 may also be implemented by a parallel circuit or a series circuit of two or more power storage devices, or a combination thereof.

[0041] The power storage unit 5 has a first end 5a and a second end 5b. The first end 5a of the power storage unit 5 is an input / output unit for inputting a charging current and a charging voltage from the charging circuit 6, or outputting (discharging) the stored power of the power storage unit 5 to the discharge circuit 7. The first end 5a of the power storage unit 5 is connected to one end of the charging circuit 42 and one end of the discharge circuit 43. The second end 5b of the power storage unit 5 is connected to the ground line 44.

[0042] (1-2-4) Charging circuit

[0043] The charging circuit 6 is a circuit for charging the power storage unit 5 using the output voltage of the power supply 2 when the power supply 2 is normal. More specifically, the charging circuit 6 transforms (e.g., boosts) the voltage of the conductive path 41 (i.e., the output voltage of the power supply 2 input from the first port P1 to the conductive path 41), maintains the transformed voltage and outputs it to the power storage unit 5, thereby charging the power storage unit 5. The charging circuit 6 may also be, for example, a buck-boost DCDC converter. The charging circuit 6 is provided in the charging path 42. The charging circuit 6 is activated and stopped according to the control of the control circuit 9.

[0044] (1-2-5) Discharge circuit

[0045] The discharge circuit 7 is a circuit for adjusting the stored power of the storage unit 5 to the voltage required by the load 3 and discharging it to the conductive path 41 instead of the power supply 2 when the power supply 2 fails (in the second mode described later), thereby supplying power to the load 3. In addition, the discharge circuit 7 is a circuit for reducing the stored power of the storage unit 5 to a predetermined threshold voltage by discharging the stored power of the storage unit 5 to the conductive path 41 when the power supply 2 fails and the load 3 does not need to be supplied from the storage unit 5 (in the third mode described later). By reducing the stored power of the storage unit 5 to the threshold voltage in this way, the life of the storage unit 5 can be extended. When discharging the stored power of the storage unit 5 to the conductive path 41, the discharge circuit 7 transforms the output voltage of the storage unit 5 to an appropriate value, maintains the transformed voltage, and discharges to the conductive path 41. The discharge circuit 7 is operated and stopped according to the control of the control circuit 9.

[0046] (1-2-6) Switch

[0047] The switch SW is a switch for turning on and off the conductive path 41, and is provided in the conductive path 41. The switch SW is provided between the first port P1 and the charging circuit 6 and between the first port P1 and the discharging circuit 7 in the conductive path 41. The switch SW switches on and off according to the control of the control circuit 9, thereby turning on and off the conductive path 41. By this disconnection, when the power supply 2 fails (in the second mode described later), the voltage of the conductive path 41 is prevented from being dragged down by the decrease in the output voltage of the power supply 2. The switch SW is composed of, for example, a semiconductor switch element such as a MOSFET (metal-oxide-semiconductor field-effect transistor) or a mechanical switch such as an electromagnetic relay.

[0048] (1-2-7) Voltage measurement circuit

[0049] The voltage measurement circuit 8 measures the output voltage of the power supply 2 by measuring the voltage of the conductive path 41 (more specifically, the voltage of the portion of the conductive path 41 between the first port P1 and the switch SW).

[0050] (1-2-8) Control circuit

[0051] The control circuit 9 controls the switch SW, the charging circuit 6, and the discharging circuit 7 based on the measurement result of the voltage measuring circuit 8 (ie, voltage information on the output voltage of the power supply 2) and status information (described later) acquired from an external device.

[0052] The above-mentioned status information is information indicating whether it is necessary to supply power from the power storage unit 5 to the load 3 or not to supply power from the power storage unit 5 to the load 3 when the power supply 2 fails. The above-mentioned status information is provided by, for example, the on / off information of the ignition signal (hereinafter referred to as "IG signal") of the vehicle 100. The on state of the IG signal means that the vehicle 100 is in motion. In addition, "in motion" includes not only the vehicle 100 in motion, but also the state in which the vehicle 100 can be started (i.e., the state in which the engine can be started in the case of an engine vehicle, and the state in which the motor can be started in the case of an electric vehicle). Therefore, "in motion" also includes temporary stops of the vehicle such as waiting for a signal. In this embodiment, the vehicle 100 in motion is a state in which the load 3 needs to be operated, and it is a state in which the power storage unit 5 needs to supply power to the load 3 when the power supply 2 fails. In addition, the off state of the IG signal means that the vehicle 100 is parked. "Parking" means that the vehicle 100 is parked, such as when the vehicle 100 is parked. In this embodiment, the vehicle 100 is parked, which is a situation where the load 3 needs to be operated, and when the power source 2 fails, it is not necessary to supply power from the power storage unit 5 to the load 3.

[0053] In more detail, the control circuit 9 determines whether the power supply 2 is normal based on the measurement result of the voltage measurement circuit 8. In other words, the control circuit 9 determines whether the power supply 2 is normal according to whether the output voltage of the power supply 2 measured by the voltage measurement circuit 8 is within a prescribed voltage range. Specifically, the control circuit 9 determines that the power supply 2 is normal when the output voltage of the power supply 2 measured by the voltage measurement circuit 8 is within a prescribed voltage range. In addition, the control circuit 9 determines that the power supply 2 is abnormal (that is, the power supply 2 fails) when the output voltage of the power supply 2 measured by the voltage measurement circuit 8 is not within the prescribed voltage range. In addition, "the power supply 2 is normal" means that the power supply 2 has not failed, and means that the power supply from the power supply 2 to the load 3 has not stopped due to a fault, degradation or disconnection.

[0054] Furthermore, control circuit 9 determines whether vehicle 100 is traveling (ie, whether power storage unit 5 needs to supply power to load 3 when power source 2 fails) based on the status information from the external device.

[0055] Furthermore, the control circuit 9 determines whether the output voltage of the power storage unit 5 (ie, the power storage voltage) is equal to or lower than a threshold voltage.

[0056] The control circuit 9 controls the switch SW, the charging circuit 6, and the discharging circuit 7 based on the above-mentioned determination result (i.e., whether the power supply 2 is normal, whether the vehicle 100 is running, and whether the output voltage of the power storage unit 5 is below the threshold voltage). Through this control, the control circuit 9 supplies the output voltage of the power supply 2 to the load 3, or charges the power storage unit 5 using the output voltage of the power supply 2, or discharges the stored power of the power storage unit 5 to the conductive path 41.

[0057] In particular, when the control circuit 9 discharges the stored power of the storage unit 5 to the conductive path 41, the control circuit 9 discharges the stored power of the storage unit 5 to the conductive path 41 via the discharge circuit 7 while stopping the charging circuit 6, thereby charging the power supply 2 and supplying it to the load 3. At this time, the voltage discharged from the storage unit 5 to the conductive path 41 (the output voltage of the discharge circuit 7) is controlled by the discharge circuit 7 to be an appropriate value. Therefore, even if the output voltage of the storage unit 5 decreases due to the discharge of the storage unit 5, the voltage supplied from the discharge circuit 7 to the load 3 (the output voltage of the discharge circuit 7) does not decrease excessively. Therefore, during the discharge of the storage unit 5, the decrease in the voltage supplied from the storage unit 5 to the load 3 can be suppressed. As a result, the load 3 can be operated by the discharge of the storage unit 5.

[0058] Then, the control circuit 9 continues the discharge of the storage unit 5 until the output voltage of the storage unit 5 drops to the threshold voltage. Then, when the output voltage of the storage unit 5 drops to the threshold voltage, the control circuit 9 stops the discharge circuit 7 and stops the discharge of the storage unit 5. By reducing the output voltage of the storage unit 5 to the threshold voltage (i.e., a relatively low voltage), the life of the storage unit 5 can be extended. In addition, the control circuit 9 supplies the output voltage of the power supply 2 to the load 3 by stopping the discharge circuit 7. Thus, even if the output voltage of the storage unit 5 drops to the threshold voltage, the load 3 can be operated by the output voltage of the power supply 2.

[0059] In addition, in this embodiment, the above-mentioned status information is provided by the on / off information of the IG signal. However, the above-mentioned status information can also be provided by various signals (gear position signal, vehicle speed signal, and sensor signal used in automatic driving / ADAS (Advanced Driver Assistance System)) that can be obtained from the vehicle 100 instead of the IG signal.

[0060] The control circuit 9 is composed of, for example, a microcomputer having a processor and a memory. That is, the control circuit 9 is implemented by a computer system having a processor and a memory. Furthermore, the computer system functions as the control circuit 9 by executing an appropriate program by the processor. The program may be recorded in advance in the memory, or may be provided through an electrical communication line such as the Internet, or recorded in a non-temporary recording medium such as a memory card. In addition, the control circuit 9 is a structure that uses a microcomputer for digital control, but may also be a structure that does not use a microcomputer for analog control.

[0061] (1-3) Action Description

[0062] Reference Figure 3 to Figure 6 , an example of the operation of the backup power supply system 1 is described.

[0063] (1-3-1) Actions when the vehicle is moving and the power supply is normal

[0064] Reference Figure 3 , which illustrates the operation when the vehicle 100 is in motion and the power source 2 is normal.

[0065] The control circuit 9 determines whether the power supply 2 is normal and whether the vehicle 100 is running based on the measurement result of the voltage measurement circuit 8 and the IG signal. If the result of the determination is that the power supply 2 is normal (i.e., the output voltage of the power supply 2 is within the prescribed voltage range) and the vehicle 100 is running (i.e., when the power supply 2 fails, it is necessary to supply power from the power storage unit 5 to the load 3), the control circuit 9 operates in the first mode.

[0066] In the first mode, the control circuit 9 turns on the switch SW, activates the charging circuit 6 (i.e., controls the charging circuit 6 to charge the storage unit 5 with the output power of the power supply 2), and stops the discharge circuit 7 (i.e., controls the discharge circuit 7 so that the stored power of the storage unit 5 is not discharged to the conductive path 41).

[0067] Therefore, if Figure 3 As shown by arrow K1, the output power of power source 2 is supplied to load 3 via wiring 10, conductive path 41 and wiring 11, so that load 3 can operate. In addition, charging circuit 6 charges power storage unit 5 using the output power of power source 2.

[0068] (1-3-2) Action when the vehicle is in motion and the power fails (power backup action)

[0069] Reference Figure 4 , the operation when the vehicle 100 is running and the power source 2 fails will be described.

[0070] The control circuit 9 determines whether the power supply 2 is normal and whether the vehicle 100 is running based on the measurement result of the voltage measurement circuit 8 and the IG signal. If the result of the determination is that the power supply 2 fails (i.e., the output voltage of the power supply 2 is not within the prescribed voltage range) and the vehicle 100 is running (i.e., when the power supply 2 fails, it is necessary to supply power from the power storage unit 5 to the load 3), the control circuit 9 operates in the second mode.

[0071] In the second mode, the control circuit 9 cuts off (disconnects) the switch SW, stops the charging circuit 6 (i.e., controls the charging circuit 6 so that the storage unit 5 is not charged by the output power of the power supply 2), and activates the discharge circuit 7 (i.e., controls the discharge circuit 7 so that the stored power of the storage unit 5 is discharged to the conductive path 41).

[0072] That is, when it is determined that the power source 2 fails, the switch SW is turned off, thereby preventing the power source 2 from being separated from the conductive path 41 and the voltage of the conductive path 41 from being attracted by the output voltage of the power source 2. In addition, by stopping the charging circuit 6 and operating the discharging circuit 7, as shown in FIG. Figure 4 As shown by arrow K2, the stored power of the power storage unit 5 is discharged to the conductive path 41 via the discharge circuit 7 and supplied to the load 3. Thus, even when the power supply 2 fails, the power supply to the load 3 can be continued by the discharge of the power storage unit 5.

[0073] (1-3-3) Actions when the vehicle is parked and the power supply is normal

[0074] (Step 1)

[0075] Reference Figure 5, illustrating the operation when the vehicle 100 is parked and the power supply 2 is normal (step 1).

[0076] The control circuit 9 determines whether the power supply 2 is normal and whether the vehicle 100 is running based on the measurement result of the voltage measurement circuit 8 and the IG signal. In addition, the control circuit 9 determines whether the storage voltage (i.e., the output voltage) of the storage unit 5 is below the threshold voltage. When the results of these determinations are that the power supply 2 is normal (i.e., the output voltage of the power supply 2 is within the prescribed voltage range), the vehicle 100 is not running (i.e., it is parked, i.e., when the power supply 2 fails, it is not necessary to supply power from the storage unit 5 to the load 3), and the storage voltage of the storage unit 5 is not below the threshold voltage (i.e., the storage voltage is relatively high), the control circuit 9 operates in the third mode.

[0077] In the third mode, the control circuit 9 turns on the switch SW, stops the charging circuit 6 (i.e., controls the charging circuit 6 so that the storage unit 5 is not charged with the output power of the power supply 2), and activates the discharge circuit 7 (i.e., controls the discharge circuit 7 so that the stored power of the storage unit 5 is discharged to the conductive path 41).

[0078] Therefore, if Figure 5 As shown by the arrow K3, the stored power of the storage unit 5 is discharged to the conductive path 41 via the discharge circuit 7. And the stored power of the storage unit 5 discharged to the conductive path 41 is supplied to the load 3 via the conductive path 41 and charges the power supply 2. Therefore, during the discharge of the storage unit 5, the output voltage of the storage unit 5 is controlled to an appropriate value by the discharge circuit 7, so that the decrease in the voltage (output voltage of the discharge circuit 7) supplied from the storage unit 5 to the load 3 can be suppressed. Therefore, during the discharge of the storage unit 5, the load 3 can be operated by the discharge of the storage unit 5.

[0079] (1-3-4) Actions when the vehicle is parked and the power supply is normal

[0080] (Step 2)

[0081] Reference Figure 6 , illustrating the operation when the vehicle 100 is parked and the power supply 2 is normal (step 2).

[0082] The control circuit 9 determines whether the power supply 2 is normal and whether the vehicle 100 is running based on the measurement result of the voltage measurement circuit 8 and the IG signal. In addition, the control circuit 9 determines whether the storage voltage (i.e., the output voltage) of the storage unit 5 is below the threshold voltage. When the results of these determinations are that the power supply 2 is normal (i.e., the output voltage of the power supply 2 is within the prescribed voltage range), the vehicle 100 is not running (i.e., it is parked, i.e., when the power supply 2 fails, it is not necessary to supply power from the storage unit 5 to the load 3), and the storage voltage of the storage unit 5 is below the threshold voltage (i.e., the storage voltage is relatively high), the control circuit 9 operates in the fourth mode.

[0083] In the fourth mode, the control circuit 9 turns on the switch SW, stops the charging circuit 6 (i.e., controls the charging circuit 6 so that the storage unit 5 is not charged with the output power of the power supply 2), and stops the discharging circuit 7 (i.e., controls the discharging circuit 7 so that the stored power of the storage unit 5 is not discharged to the conductive path 41).

[0084] That is, when the storage voltage of the storage unit 5 drops to the threshold voltage in the third mode, the control circuit 9 switches to the fourth mode and further stops the discharge circuit 7 to stop the discharge of the storage unit 5. As a result, the storage voltage of the storage unit 5 is maintained at the threshold voltage (i.e., a relatively low voltage). As a result, the storage voltage of the storage unit 5 is maintained at a relatively low voltage, thereby extending the life of the storage unit 5. In addition, as Figure 6 As shown by arrow K4, after the storage unit 5 is discharged, the output voltage of the power supply 2 is supplied to the load 3 via the conductive path 41. Therefore, after the storage unit 5 is discharged, even if the storage voltage (i.e., output voltage) of the storage unit 5 is low, the load 3 can be operated by the output voltage of the power supply 2.

[0085] (1-3-5) Operation description of the flowchart

[0086] Next, refer to Figure 7 The operation of the backup power supply system 1 will be described.

[0087] The control circuit 9 determines whether the vehicle 100 as a moving body is running based on the IG signal (step S1). If the result of the determination is that the vehicle 100 is running (step S1: Yes), the control circuit 9 further determines whether the power supply 2 is normal based on the measurement result of the voltage measurement circuit 8 (step S2). If the result of the determination is that the power supply 2 is normal (step S2: Yes), the control circuit 9 proceeds to step S3 and operates in the first mode described above (see step S1). Figure 3 ). Therefore, if Figure 3As shown by arrow K1, the output power of power source 2 is supplied to load 3 via wiring 10, conductive path 41 and wiring 11, and load 3 can be operated. In addition, charging circuit 6 charges power storage unit 5 using the output voltage of power source 2. Then, the process returns to step S1.

[0088] In addition, if the result of the determination in step S2 is that the power supply 2 is abnormal (i.e., the power supply 2 fails) (step S2: No), the control circuit 9 proceeds to step S4 and operates in the above-mentioned second mode (refer to Figure 4 ). Therefore, if Figure 4 As shown by arrow K2, the stored power of the power storage unit 5 is discharged to the conductive path 41 via the discharge circuit 7 and supplied to the load 3. Thus, even if the power supply 2 fails, the power supply to the load 3 can continue by discharging the power storage unit 5. Then, the process returns to step S1.

[0089] In addition, when the result of the determination in step S1 is that the vehicle 100 is not traveling (i.e., parked) (step S1: No), the control circuit 9 further determines whether the power supply 2 is normal based on the measurement result of the voltage measurement circuit 8 (step S5). When the result of the determination is that the power supply 2 is not normal (i.e., the power supply 2 is faulty) (step S5: No), the process returns to step S1.

[0090] On the other hand, if the result of the determination in step S1 is that the power supply 2 is normal (step S5: Yes), the control circuit 9 further determines whether the storage voltage of the storage unit 5 is below the threshold voltage (step S6). Then, if the result of the determination in step S6 is that the storage voltage of the storage unit 5 is not below the threshold voltage (step S6: No), the control circuit 9 proceeds to step S7 and operates in the third mode described above (see step S6). Figure 5 ). Therefore, if Figure 5 As shown by the arrow K3, the stored power of the storage unit 5 is discharged to the conductive path 41 via the discharge circuit 7. And the stored power of the storage unit 5 discharged to the conductive path 41 is supplied to the load 3 via the conductive path 41 and charges the power supply 2. Therefore, during the discharge of the storage unit 5, the output voltage of the storage unit 5 is controlled to an appropriate value by the discharge circuit 7, so that the decrease in the voltage (output voltage of the discharge circuit 7) supplied from the storage unit 5 to the load 3 can be suppressed. Thus, during the discharge of the storage unit 5, the load 3 can be operated by the discharge of the storage unit 5. Then, the process returns to step S6.

[0091] In addition, when the result of the determination in step S6 is that the storage voltage of the storage unit 5 is below the threshold voltage (step S6: Yes), the control circuit 9 proceeds to step S8 and operates in the fourth mode described above. In the fourth mode, as described above, the discharge circuit 7 stops, and the discharge of the storage unit 5 stops. As a result, the storage voltage of the storage unit 5 is maintained at the threshold voltage (i.e., a relatively low voltage), so that the life of the storage unit 5 can be extended. In addition, in the fourth mode (i.e., after the storage unit 5 is discharged), if Figure 6 As shown by arrow K4, the output voltage of the power supply 2 is supplied to the load 3 via the conductive path 41. Therefore, after the power storage unit 5 is discharged, even if the storage voltage (i.e., the output voltage) of the power storage unit 5 is low, the load 3 can be operated by the output voltage of the power supply 2. Then, the process returns to step S1.

[0092] (1-4) Main effects

[0093] As described above, the backup power supply system 1 of the present embodiment is a backup power supply system connected between the power supply 2 and the load 3. The backup power supply system 1 includes a first port P1, a second port P2, a conductive path 41, a power storage unit 5, a charging circuit 6, a discharging circuit 7, a switch SW, and a control circuit 9. The first port P1 is connected to the power supply 2. The second port P2 is connected to the load 3. The conductive path 41 connects the first port P1 and the second port P2. The charging circuit 6 is provided in a charging path 42 (first path) connecting the conductive path 41 and the power storage unit 5, and charges the power from the conductive path 41 to the power storage unit 5. The discharging circuit 7 is provided in a discharging circuit 43 (second path) connecting the conductive path 41 and the power storage unit 5, and discharges the stored power of the power storage unit 5 to the conductive path 41. The switch SW is provided in the conductive path 41 between the first port P1 and the charging circuit 6 and between the first port P1 and the discharging circuit 7, and turns on and off the conductive path 41. The control circuit 9 controls the switch SW, the charging circuit 6, and the discharging circuit 7.

[0094] According to this configuration, the discharge of the storage unit 5 can be performed by discharging the stored power of the storage unit 5 to the conductive path 41 via the discharge circuit 7 while the charging circuit 6 is stopped by the control circuit 9. As a result, the stored power of the storage unit 5 is charged (regenerated) to the power supply 2 through the discharge circuit 7 and supplied to the load 3. At this time, the voltage discharged from the storage unit 5 to the conductive path 41 (that is, the output voltage of the discharge circuit 7) is controlled to an appropriate value by the discharge circuit 7. Therefore, even if the output voltage of the storage unit 5 decreases due to the discharge of the storage unit 5, the voltage supplied from the discharge circuit 7 to the load 3 (the output voltage of the discharge circuit 7) does not decrease excessively. Therefore, even during the discharge of the storage unit 5, the decrease in the voltage supplied from the storage unit 5 to the load 3 can be suppressed. As a result, even during the discharge of the storage unit 5, the load 3 can be operated by the discharge of the storage unit 5.

[0095] (1-5) Control methods of backup power supply systems, etc.

[0096] The same functions as those of the backup power supply system 1 of the above-described embodiment can also be realized by a control method of the backup power supply system, a computer program (program), or a non-transitory recording medium recording the computer program.

[0097] A control method of a backup power supply system according to one embodiment is a control method of a backup power supply system 1 connected between a power supply 2 and a load 3. The backup power supply system 1 includes a first port P1, a second port P2, a conductive path 41, a power storage unit 5, a charging circuit 6, a discharging circuit 7, a switch SW, and a control circuit 9. The first port P1 is connected to the power supply 2. The second port P2 is connected to the load 3. The conductive path 41 connects the first port P1 and the second port P2. The charging circuit 6 is provided in a charging path 42 (first path) connecting the conductive path 41 and the power storage unit 5, and charges the power from the conductive path 41 to the power storage unit 5. The discharging circuit 7 is provided in a discharging circuit 43 (second path) connecting the conductive path 41 and the power storage unit 5, and discharges the stored power of the power storage unit 5 to the conductive path 41. The switch SW is provided in the conductive path 41 between the first port P1 and the charging circuit 6 and between the first port P1 and the discharging circuit 7, and turns on and off the conductive path 41. The control method of the backup power supply system 1 includes a control process of controlling the switch SW, the charging circuit 6, and the discharging circuit 7 by the control circuit 9. In the above control process, when the stored power of the storage unit 5 is discharged, the stored power of the storage unit 5 is discharged to the conductive path 41 via the discharging circuit 7 while the charging circuit 6 is stopped, thereby charging the power supply 2 and supplying it to the load 3.

[0098] A program according to one embodiment causes one or more processors to execute the control method of the backup power supply system.

[0099] A non-transitory recording medium in one embodiment records a program that causes one or more processors to execute the control method of the backup power supply system.

[0100] (1-6) Modification

[0101] Next, modifications of the above-described embodiment will be described. The following modifications can be implemented in combination.

[0102] (Variant 1)

[0103] In the above embodiment, the discharge voltage (ie, output voltage) of the discharge circuit 7 may be different in the second mode (first operation mode) (ie, during standby operation) and in the third mode (second operation mode) (ie, during power regeneration).

[0104] In more detail, when the discharge circuit 7 discharges the stored power of the storage unit 5 to the conductive path 41 in the second mode and the third mode, the discharge voltage of the discharge circuit 7 is transformed into the first voltage or the second voltage according to whether the current mode is the second mode or the third mode. Furthermore, the discharge circuit 7 maintains the discharge voltage of the discharge circuit 7 at the above-mentioned changed voltage (the first voltage or the second voltage) and discharges the discharged power of the storage unit 5 to the conductive path 41.

[0105] The first voltage is the discharge voltage of the discharge circuit 7 in the second mode. In the second mode, since the power supply 2 fails, the discharge voltage of the discharge circuit 7 (i.e., the voltage after the storage voltage of the storage unit 5 is transformed by the discharge circuit 7) is supplied to the load 3 instead of the power supply 2. Therefore, the first voltage is set to an operation voltage suitable for the operation of the load 3. More specifically, the operation voltage range of the load 3 is generally within a voltage range of 8V to 16V, for example. In order to make the load 3 perform a power saving operation, the first voltage is set to a voltage near the lower limit value (e.g., 10V) within the operation voltage range (8V to 16V) of the load 3.

[0106] The second voltage is the discharge voltage of the discharge circuit 7 in the third mode. In the third mode, the power supply 2 is charged (regenerated) by the discharge voltage of the discharge circuit 7 (i.e., the voltage after the storage voltage of the storage unit 5 is transformed by the discharge circuit 7). Therefore, the second voltage is set to a charging voltage suitable for charging the power supply 2. In more detail, the setting range of the output voltage of the power supply 2 is generally within the voltage range of 8V to 16V, for example. The second voltage is set to an upper limit value (16V) within the setting range (8V to 16V) of the output voltage of the power supply 2 to limit the charging current to the power supply 2 and charge the power supply 2 slowly.

[0107] In Modification 1, for example, the first voltage (eg, 10 V) is set to a value smaller than the second voltage (eg, 16 V). However, the first voltage may be the same value as the second voltage or a value larger than the second voltage.

[0108] According to Modification 1, the discharge voltage of the discharge circuit 7 can be changed to a discharge voltage suitable for each mode (the second mode and the third mode), and the stored power of the storage unit 5 can be discharged to the conductive path 41 via the discharge circuit 7 .

[0109] (Variant 2)

[0110] In the above embodiment, the upper limit value of the discharge current (ie, output current) of the discharge circuit 7 may be different in the second mode (first operation mode) (ie, during standby operation) and in the third mode (second operation mode) (ie, during power regeneration).

[0111] In more detail, when the discharge circuit 7 discharges the stored power of the storage unit 5 to the conductive path 41 in the second mode and the third mode, the upper limit value of the discharge current of the discharge circuit 7 is changed to the first upper limit value or the second upper limit value according to whether the current mode is the second mode or the third mode. And, the discharge circuit 7 discharges the stored power of the storage unit 5 to the conductive path 41 while controlling the discharge current of the discharge circuit 7 so as not to exceed the changed upper limit value.

[0112] The first upper limit is the upper limit of the discharge current of the discharge circuit 7 in the second mode. In the second mode, the discharge current of the discharge circuit 7 is supplied from the conductive path 41 to the load 3 via the wiring 11. Therefore, the first upper limit is set to the upper limit of the allowable current of the wiring 11 (for example, 30A).

[0113] The second upper limit value is the upper limit value of the discharge current of the discharge circuit 7 in the third mode. In the third mode, the discharge current of the discharge circuit 7 charges (regenerates) the power supply 2 from the conductive path 41 via the wiring 10. Therefore, the second upper limit value is set to the upper limit value of the allowable current of the wiring 10 (for example, 5A).

[0114] In Modification 2, for example, the first upper limit value (eg, 30) is set to a value greater than the second upper limit value (eg, 5 A). However, the first upper limit value may be the same as the second upper limit value or may be a value smaller than the second upper limit value.

[0115] According to Modification 2, the discharge current of discharge circuit 7 can be changed to a discharge current suitable for each mode (second mode and third mode), and the stored power of storage unit 5 can be discharged to conductive path 41 via discharge circuit 7 .

[0116] (Variant 3)

[0117] In the above-mentioned embodiment, the charging circuit 6 and the discharging circuit 7 have different structures (see Figure 1 ), but the charging circuit 6 and the discharging circuit 7 can also be integrated by a charging and discharging circuit 13 (refer to Figure 8 ). In this case, if Figure 8 As shown, the charging circuit 42 and the discharging circuit 43 in the above-mentioned embodiment are integrated by a charging and discharging circuit 45. The charging and discharging circuit 45 connects the branch point N3 of the conductive path 41 and the first end 5a of the storage unit 5. The charging and discharging circuit 13 is provided in the charging and discharging circuit 45. According to this structure, the number of components of the backup power supply system 1 can be reduced, which can contribute to the miniaturization of the backup power supply system 1.

[0118] (Variant 4)

[0119] In the above-mentioned embodiment, the charging circuit 6 may be configured to include one of a boost circuit and a buck circuit, and the discharging circuit 7 may be configured to include the other of a boost circuit and a buck circuit. That is, the charging circuit 6 may include a boost circuit and the discharging circuit 7 may include a buck circuit, or the charging circuit 6 may include a buck circuit and the discharging circuit 7 may include a boost circuit. According to this structure, the charging circuit 6 and the discharging circuit 7 may be configured by a boost circuit and a buck circuit (i.e., a known circuit).

[0120] (Variant 5)

[0121] In the above embodiment, the control circuit 9 controls the switch SW, the charging circuit 6, and the discharging circuit 7 based on both the voltage information and the status information. However, the control circuit 9 may control the switch SW, the charging circuit 6, and the discharging circuit 7 based on at least one of the voltage information and the status information.

[0122] (2) Summary

[0123] According to the above-described embodiment and modified examples, the present disclosure includes the following aspects.

[0124] A backup power supply system (1) of a first embodiment is connected between a power supply (2) and a load (3). The backup power supply system (1) includes a first port (P1), a second port (P2), a conductive path (41), a power storage unit (5), a charging circuit (6), a discharging circuit (7), a switch (SW), and a control circuit (9). The first port (P1) is connected to the power supply (2). The second port (P2) is connected to the load (3). The conductive path (41) connects the first port (P1) and the second port (P2). The charging circuit (6) is provided in a first path (42) connecting the conductive path (41) and the power storage unit (5), and charges the power storage unit (5) with power from the conductive path (41). The discharging circuit (7) is provided in a second path (43) connecting the conductive path (41) and the power storage unit (5), and discharges the stored power of the power storage unit (5) to the conductive path (41). The switch (SW) is arranged in a conductive path (41) between the first port (P1) and the charging circuit (6) and between the first port (P1) and the discharging circuit (7), and switches the conductive path (41) on and off. The control circuit (9) controls the switch (SW), the charging circuit (6) and the discharging circuit (7).

[0125] According to this configuration, the discharge of the storage unit (5) can be performed by discharging the stored power of the storage unit (5) to the conductive path (41) via the discharge circuit (7) in a state where the charging circuit (6) is stopped by the control circuit (9). As a result, the stored power of the storage unit (5) is charged (regenerated) to the power source (2) via the discharge circuit (7) and is simultaneously supplied to the load (3). At this time, the voltage discharged from the storage unit (5) to the conductive path (41) (i.e., the discharge voltage of the discharge circuit (7)) is controlled to an appropriate value by the discharge circuit (7). Therefore, even if the output voltage of the storage unit (5) decreases due to the discharge of the storage unit (5), the voltage supplied from the discharge circuit (7) to the load (3) (i.e., the output voltage of the discharge circuit (7)) does not decrease excessively. Therefore, during the discharge of the storage unit (5), the decrease in the voltage supplied from the storage unit (5) to the load (3) (i.e., the output voltage of the discharge circuit (7)) can be suppressed. Thus, during the discharge of the power storage unit (5), the load (3) can be operated by the discharge of the power storage unit (5).

[0126] In the backup power supply system (1) of the second mode, in the first mode, the control circuit (9) discharges the stored power of the storage unit (5) through the discharge circuit (7) to the conductive path (41) while stopping the charging circuit (6) to charge the power supply (2) and supply it to the load (3).

[0127] According to this structure, when the stored power of the storage unit (5) is discharged, the stored power of the storage unit (5) is charged (regenerated) to the power supply (2) from the conductive path (41) and supplied to the load (3). At this time, the voltage supplied from the storage unit (5) to the load (3) (i.e., the discharge voltage of the discharge circuit (7)) is controlled by the discharge circuit (7) to be an appropriate value. Therefore, even if the output voltage of the storage unit (5) decreases, the voltage supplied from the discharge circuit (7) to the load (3) (i.e., the output voltage of the storage unit (5)) does not decrease excessively. Therefore, during the discharge of the storage unit (5), the decrease in the voltage supplied from the storage unit (5) to the load (3) can be suppressed. Therefore, during the discharge of the storage unit (5), the load (3) can be operated by the discharge of the storage unit (5).

[0128] In a backup power supply system (1) of a third aspect, in the first aspect or the second aspect, a control circuit (9) acquires at least one of voltage information related to an output voltage of a power supply (2) and status information indicating whether it is necessary to supply power from a power storage unit (5) to a load (3) when the power supply (2) fails. The control circuit (9) controls a switch (SW), a charging circuit (6), and a discharging circuit (7) based on at least one of the acquired voltage information and status information.

[0129] According to this configuration, the switch (SW), the charging circuit (6), and the discharging circuit (7) can be controlled based on at least one of the voltage information and the status information.

[0130] A fourth aspect of the backup power supply system (1) is provided in the third aspect, further comprising a voltage measuring circuit (8) for measuring a voltage of a conductive path (41) between the first port (P1) and the switch (SW). The control circuit (9) obtains voltage information by obtaining a measurement result of the voltage measuring circuit (8).

[0131] According to this configuration, voltage information (that is, information related to the output voltage of the power supply (2)) can be appropriately acquired by the voltage measuring circuit (8).

[0132] In the backup power supply system (1) of the fifth aspect, in the third or fourth aspect, the status information is an ignition signal obtained from a vehicle (100) equipped with the backup power supply system (1). When the ignition signal is turned on, it is necessary to supply power from the power storage unit (5) to the load (3) when the power supply (2) fails. When the ignition signal is turned off, it is not necessary to supply power from the power storage unit (5) to the load (3) when the power supply (2) fails.

[0133] According to this configuration, the above-mentioned status information can be acquired through the ignition signal (that is, through a signal that can be easily acquired).

[0134] In a backup power supply system (1) of a sixth aspect, in any one of the first to fifth aspects, a condition in which power supply from the power storage unit (5) to the load (3) is required when the power supply (2) fails is a condition in which a vehicle equipped with the backup power supply system (1) is traveling. A condition in which power supply from the power storage unit (5) to the load (3) is not required when the power supply (2) fails is a condition in which the vehicle (100) is parked.

[0135] According to this structure, the switch (SW), the charging circuit (6) and the discharging circuit (7) can be controlled according to whether the vehicle (100) equipped with the backup power supply system (1) is running or stopped.

[0136] In a backup power supply system (1) of a seventh aspect, in any one of the first to sixth aspects, the charging circuit (6) and the discharging circuit (7) are constituted by one charging and discharging circuit (13).

[0137] According to this structure, the number of components of the backup power supply system (1) can be reduced. As a result, it can contribute to the miniaturization of the backup power supply system (1).

[0138] In the backup power supply system (1) of the eighth aspect, in any one of the first to seventh aspects, the charging circuit (6) includes one of a step-up circuit and a step-down circuit, and the discharging circuit (7) includes the other of the step-up circuit and the step-down circuit.

[0139] According to this structure, the charging circuit (6) and the discharging circuit (7) can be constituted by a step-up circuit and a step-down circuit (that is, known circuits).

[0140] In a ninth embodiment of a backup power supply system (1), in any of the first to eighth embodiments, when the power supply (2) fails and there is no need to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is within a prescribed voltage range, and the stored voltage of the power storage unit (5) is not less than a threshold voltage, the control circuit (9) turns on the switch (SW), controls the charging circuit (6) in a manner that the power storage unit (5) is not charged with the output power of the power supply (2), and controls the discharging circuit (7) in a manner that the stored power of the power storage unit (5) is discharged to the conductive path (41).

[0141] According to this configuration, when the power supply (2) fails and it is not necessary to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is within a predetermined voltage range (i.e., the power supply (2) is normal), and the storage voltage of the power storage unit (5) is not less than a threshold voltage (i.e., the storage voltage of the power storage unit (5) is relatively high), the stored power of the power storage unit (5) can be discharged to the conductive path (41) via the discharge circuit (7). Therefore, during the discharge of the power storage unit (5), the output voltage of the power storage unit (5) is controlled to an appropriate value by the discharge circuit (7), so that the voltage supplied from the power storage unit (5) to the load (3) (i.e., the output voltage of the discharge circuit (7)) can be suppressed from decreasing. Therefore, during the discharge of the power storage unit (5), the load (3) can be operated by the discharge of the power storage unit (5).

[0142] In a backup power supply system (1) of a tenth embodiment, in any one of the first to ninth embodiments, when the power supply (2) fails and there is no need to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is within a prescribed voltage range, and the stored voltage of the power storage unit (5) is below a threshold voltage, the control circuit (9) turns on the switch (SW), charges the power storage unit (5) without using the output power of the power supply (2), and controls the discharge circuit (7) in such a manner that the stored power of the power storage unit (5) is not discharged to the conductive path (41).

[0143] According to this structure, when the power supply (2) fails and it is not necessary to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is within a specified voltage range (i.e., the power supply (2) is normal), and the storage voltage of the power storage unit (5) is below a threshold voltage, the storage voltage of the power storage unit (5) can be maintained at the threshold voltage (i.e., a relatively low voltage). Thus, the life of the power storage unit (5) can be extended. In addition, the output voltage of the power supply (2) is supplied to the load (3) via the conductive path (41), so that even if the storage voltage of the power storage unit (5) is low, the load (3) can be operated by the output voltage of the power supply (2).

[0144] In the backup power supply system (1) of the eleventh embodiment, in the ninth or tenth embodiment, when the power supply (2) fails and it is necessary to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is within a prescribed voltage range, the control circuit (9) turns on the switch (SW), controls the charging circuit (6) in such a manner that the power storage unit (5) is charged with the output power of the power supply (2), and controls the discharging circuit (7) in such a manner that the stored power of the power storage unit (5) is not discharged to the conductive path (41).

[0145] According to this structure, when the power supply (2) fails and it is necessary to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is within a prescribed voltage range (i.e., the power supply (2) is normal), the output power of the power supply (2) can be used to supply power to the load (3) and charge the power storage unit (5).

[0146] In a backup power supply system (1) of a twelfth mode, in any of the ninth to eleventh modes, when the power supply (2) fails and it is necessary to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is not within a prescribed voltage range, the control circuit (9) cuts off the switch (SW), controls the charging circuit (6) in a manner not to charge the power storage unit (5) using the output power of the power supply (2), and controls the discharging circuit (7) in a manner to discharge the stored power of the power storage unit (5) to the conductive path (41).

[0147] According to this structure, when the power supply (2) fails and it is necessary to supply power from the power storage unit (5) to the load (3), and the output voltage of the power supply (2) is not within a predetermined voltage range (i.e., the power supply (2) fails), the stored power of the power storage unit (5) can be discharged to the conductive path (41) through the discharge circuit (7). Thus, when the power supply (2) fails, the load (3) can be supplied (i.e., the load (3) can be operated) by discharging the power storage unit (5).

[0148] In the backup power supply system (1) of the thirteenth aspect, in any one of the first to twelfth aspects, the control circuit (9) turns off the switch (SW), controls the charging circuit (6) in a manner that the storage unit (5) is not charged with the output power of the power supply (2), and controls the operation of the discharge circuit (7) in a manner that the stored power of the storage unit (5) is discharged to the conductive path (41) as a first operation mode. The control circuit (9) turns on the switch (SW), controls the charging circuit (6) in a manner that the storage unit (5) is not charged with the output power of the power supply (2), and controls the operation of the discharge circuit (7) in a manner that the stored power of the storage unit (5) is discharged to the conductive path (41) as a second operation mode. When the discharge circuit (7) discharges the stored power of the storage unit (5) to the conductive path (41), the discharge voltage of the discharge circuit (7) is different between the first operation mode and the second operation mode.

[0149] According to this structure, the discharge voltage of the discharge circuit (7) can be changed to a discharge voltage suitable for each operation mode (first operation mode and second operation mode), and the stored power of the storage unit (5) can be discharged to the conductive path (41) via the discharge circuit (7).

[0150] In a backup power supply system (1) of a fourteenth aspect, in any one of the first to thirteenth aspects, the control circuit (9) turns off the switch (SW), controls the charging circuit (6) in a manner that the storage unit (5) is not charged with the output power of the power supply (2), and controls the operation of the discharge circuit (7) in a manner that the stored power of the storage unit (5) is discharged to the conductive path (41), which is set to a first operation mode. The control circuit (9) turns on the switch (SW), controls the charging circuit (6) in a manner that the storage unit (5) is not charged with the output power of the power supply (2), and controls the operation of the discharge circuit (7) in a manner that the stored power of the storage unit (5) is discharged to the conductive path (41), which is set to a second operation mode. When the discharge circuit (7) discharges the stored power of the storage unit (5) to the conductive path (41), the upper limit value of the discharge current of the discharge circuit (7) is different between the first operation mode and the second operation mode.

[0151] According to this structure, the upper limit value of the discharge current of the discharge circuit (7) can be changed to an upper limit value suitable for each operation mode (first operation mode and second operation mode), and the stored power of the storage unit (5) can be discharged to the conductive path (41) via the discharge circuit (7).

[0152] A mobile body (100) of a fifteenth aspect comprises a backup power supply system (1) of any one of the first to thirteenth aspects, a power supply (2), a load (3), and a mobile body (101). The mobile body (101) is provided with a backup power supply system (1), a power supply (2), and a load (3).

[0153] According to this structure, a mobile object (100) including the above-mentioned backup power supply system (1) can be provided.

[0154] In a sixteenth embodiment, a control method for a backup power supply system (1) is provided, which is a control method for a backup power supply system (1) connected between a power supply (2) and a load (3). The backup power supply system (1) comprises a first port (P1), a second port (P2), a conductive path (41), a power storage unit (5), a charging circuit (6), a discharging circuit (7), a switch (SW), and a control circuit (9). The first port (P1) is connected to the power supply (2). The second port (P2) is connected to the load (3). The conductive path (41) connects the first port (P1) and the second port (P2). The charging circuit (6) is provided in a first path (42) connecting the conductive path (41) and the power storage unit (5), and charges the power storage unit (5) with power from the conductive path (41). The discharging circuit (7) is provided in a second path (43) connecting the conductive path (41) and the power storage unit (5), and discharges the stored power of the power storage unit (5) to the conductive path (41). The switch (SW) is provided in a conductive path (41) between the first port (P1) and the charging circuit (6) and between the first port (P1) and the discharging circuit (7), and switches the conductive path (41) on and off. The control method of the backup power supply system (1) comprises a control step of controlling the switch (SW), the charging circuit (6) and the discharging circuit (7) by a control circuit (9). In the above control step, when the stored power of the storage unit (5) is discharged, the stored power of the storage unit (5) is discharged to the conductive path (41) via the discharging circuit (7) in a state where the charging circuit (6) is stopped, thereby charging the power supply (2) and supplying it to the load (3).

[0155] According to this structure, during the discharge of the storage unit (5), the stored power of the storage unit (5) is charged (regenerated) to the power supply (2) from the conductive path (41) and supplied to the load (3). At this time, the voltage supplied from the storage unit (5) to the load (3) (i.e., the output voltage of the discharge circuit (7)) is controlled by the discharge circuit (7) to be an appropriate value. Therefore, even if the output voltage of the storage unit (5) decreases due to the discharge of the storage unit (5), the voltage supplied from the discharge circuit (7) to the load (3) (i.e., the output voltage of the discharge circuit (7)) does not decrease excessively. Therefore, during the discharge of the storage unit (5), the decrease in the voltage supplied from the storage unit (5) to the load (3) (i.e., the output voltage of the discharge circuit (7)) can be suppressed. Therefore, during the discharge of the storage unit (5), the load (3) can be operated by the discharge of the storage unit (5).

[0156] The program of the seventeenth aspect causes one or more processors to execute the control method of the backup power supply system of the sixteenth aspect.

[0157] According to this configuration, it is possible to provide a program for causing one or more processors to execute the method for controlling the backup power supply system.

[0158] Description of Reference Numerals

[0159] 1. Backup power system

[0160] 2 Power supply

[0161] 3 Load

[0162] 5. Power storage unit

[0163] 6 Charging Circuit

[0164] 7. Discharge circuit

[0165] 8 Voltage measurement circuit

[0166] 9. Control Circuit

[0167] 13. Charge and discharge circuit

[0168] P1 first port

[0169] P2 Second Port

[0170] 41 Conductive Path

[0171] 42 Charging path (first path)

[0172] 43 Amplifier circuit (second path)

[0173] 100 vehicles (mobile objects)

[0174] 101 Vehicle body (mobile body)

Claims

1. A backup power system connected between a power source and a load, wherein: have: A first port connected to the power source; A second port connected to the load; a conductive path connecting the first port and the second port; Power storage unit; a charging circuit provided in a first path connecting the conductive path and the power storage unit, for charging the power storage unit with electric power from the conductive path; a discharge circuit provided in a second path connecting the conductive path and the power storage unit, for discharging the stored power of the power storage unit to the conductive path; A switch, disposed between the first port and the charging circuit and forming the conductive path between the first port and the discharging circuit, for switching on and off the conductive path; as well as A control circuit controls the switch, the charging circuit and the discharging circuit.

2. The backup power supply system according to claim 1, wherein: When discharging the stored power of the storage unit, the control circuit discharges the stored power of the storage unit to the conductive path via the discharge circuit while stopping the charging circuit, thereby charging the power supply and supplying the power to the load.

3. The backup power supply system according to claim 1 or 2, wherein: The control circuit obtains at least one of voltage information related to the output voltage of the power supply and status information indicating whether power needs to be supplied from the power storage unit to the load when the power supply fails, and controls the switch, the charging circuit and the discharging circuit based on the obtained voltage information and at least one of the status information.

4. The backup power supply system according to claim 3, wherein: further comprising a voltage measuring circuit for measuring a voltage of the conductive path between the first port and the switch, The control circuit acquires the voltage information by acquiring a measurement result of the voltage measurement circuit.

5. The backup power supply system according to claim 3, wherein: The status information is an ignition signal obtained from a vehicle equipped with the backup power system. The ignition signal is turned on when the power supply fails and the load needs to be supplied with power from the power storage unit. The case where the ignition signal is off is a situation where it is not necessary to supply power from the power storage unit to the load when the power supply fails.

6. The backup power supply system according to claim 1 or 2, wherein: In a situation where the power storage unit needs to supply power to the load when the power source fails, the vehicle equipped with the backup power source system is running. The situation in which it is not necessary to supply power from the power storage unit to the load when the power supply fails is a situation in which the vehicle is parked.

7. The backup power supply system according to claim 1 or 2, wherein: The charging circuit and the discharging circuit are constituted by one charging and discharging circuit.

8. The backup power supply system according to claim 1 or 2, wherein: The charging circuit includes one of a boost circuit and a buck circuit, and the discharging circuit includes the other of the boost circuit and the buck circuit.

9. The backup power system according to claim 1, wherein: When the power supply fails and the load does not need to be supplied with power from the power storage unit, and the output voltage of the power supply is within a predetermined voltage range and the storage voltage of the power storage unit is not less than a threshold voltage, The control circuit: Turning on the switch, and controlling the charging circuit so that the power storage unit is not charged with the output power of the power supply. Furthermore, the discharge circuit is controlled so that the stored electric power of the electric storage unit is discharged to the conductive path.

10. The backup power supply system according to claim 9, wherein: When the power supply fails and there is no need to supply power from the power storage unit to the load, and the output voltage of the power supply is within the predetermined voltage range and the storage voltage of the power storage unit is less than or equal to the threshold voltage, The control circuit: Turning on the switch, and controlling the charging circuit so that the power storage unit is not charged with the output power of the power supply, The discharge circuit is controlled so that the stored electric power of the electric storage unit is not discharged to the conductive path.

11. The backup power supply system according to claim 9 or 10, wherein: In a situation where the power supply fails and the load needs to be supplied with power from the power storage unit, and the output voltage of the power supply is within the predetermined voltage range, The control circuit: Turning on the switch, and controlling the charging circuit so that the power storage unit is charged with the output power of the power supply, The discharge circuit is controlled so that the stored electric power of the electric storage unit is not discharged to the conductive path.

12. The backup power supply system according to claim 9 or 10, wherein: When the power supply fails and the load needs to be supplied with power from the power storage unit, and the output voltage of the power supply is not within the predetermined voltage range, The control circuit: The switch is turned off, and controlling the charging circuit so that the power storage unit is not charged with the output power of the power supply, The discharge circuit is controlled so that the stored electric power of the electric storage unit is discharged to the conductive path.

13. The backup power supply system according to claim 1 or 2, wherein: The control circuit turns off the switch, controls the charging circuit in a manner that the power storage unit is not charged with the output power of the power supply, and controls the discharge circuit in a manner that the stored power of the power storage unit is discharged to the conductive path, as a first operation mode, The control circuit turns on the switch, controls the charging circuit so as not to charge the power storage unit with the output power of the power supply, and controls the discharge circuit so as to discharge the stored power of the power storage unit to the conductive path, as a second operation mode, When the discharge circuit discharges the stored power of the power storage unit to the conductive path, a discharge voltage of the discharge circuit is different between the first operation mode and the second operation mode.

14. The backup power supply system according to claim 1 or 2, wherein: The control circuit turns off the switch, controls the charging circuit in a manner that the power storage unit is not charged with the output power of the power supply, and controls the discharge circuit in a manner that the stored power of the power storage unit is discharged to the conductive path, as a first operation mode, The control circuit turns on the switch, controls the charging circuit so as not to charge the power storage unit with the output power of the power supply, and controls the discharge circuit so as to discharge the stored power of the power storage unit to the conductive path, as a second operation mode, When the discharge circuit discharges the stored electric power of the electric storage unit to the conductive path, an upper limit value of a discharge current of the discharge circuit is set to be different between the first operation mode and the second operation mode.

15. A mobile object, comprising: The backup power supply system according to claim 1 or 2; the power supply; the load; and The mobile body is provided with the backup power supply system, the power supply and the load.

16. A control method for a backup power system, wherein the backup power system is connected between a power source and a load, wherein: The control method of the backup power supply system comprises a preparation step and a control step. The preparation step prepares the following backup power system, which includes: A first port connected to the power source; A second port connected to the load; a conductive path connecting the first port and the second port; Power storage unit; a charging circuit provided in a first path connecting the conductive path and the power storage unit, for charging the power storage unit with electric power from the conductive path; a discharge circuit provided in a second path connecting the conductive path and the power storage unit, for discharging the stored power of the power storage unit to the conductive path; as well as a switch, disposed between the first port and the charging circuit and forming the conductive path between the first port and the discharging circuit, for conducting and cutting off the conductive path; The control step uses a control circuit to control the switch, the charging circuit, and the discharging circuit. In the control step, when discharging the stored power of the storage unit, the stored power of the storage unit is discharged to the conductive path via the discharge circuit while the charging circuit is stopped, thereby charging the power supply and supplying it to the load.

17. A program causing one or more processors to execute the control method of the backup power supply system according to claim 16.

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