WO2012169171A1 - Vehicle power-supply system - Google Patents

Vehicle power-supply system Download PDF

Info

Publication number
WO2012169171A1
WO2012169171A1 PCT/JP2012/003658 JP2012003658W WO2012169171A1 WO 2012169171 A1 WO2012169171 A1 WO 2012169171A1 JP 2012003658 W JP2012003658 W JP 2012003658W WO 2012169171 A1 WO2012169171 A1 WO 2012169171A1
Authority
WO
WIPO (PCT)
Prior art keywords
voltage
power supply
diodes
storage battery
unit
Prior art date
Application number
PCT/JP2012/003658
Other languages
French (fr)
Japanese (ja)
Inventor
森本　直久
Original Assignee
パナソニック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パナソニック株式会社 filed Critical パナソニック株式会社
Publication of WO2012169171A1 publication Critical patent/WO2012169171A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
    • B60L58/20—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules having different nominal voltages
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
    • H02J7/342—The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/54—Drive Train control parameters related to batteries
    • B60L2240/547—Voltage
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/54—Drive Train control parameters related to batteries
    • B60L2240/549—Current
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2310/00—The network for supplying or distributing electric power characterised by its spatial reach or by the load
    • H02J2310/40—The network being an on-board power network, i.e. within a vehicle
    • H02J2310/48—The network being an on-board power network, i.e. within a vehicle for electric vehicles [EV] or hybrid vehicles [HEV]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries

Definitions

  • the present invention relates to a vehicle power supply system using a storage battery mounted on a vehicle.
  • An electric vehicle Electric Vehicle
  • HEV Hybrid Electric Vehicle
  • a traction battery which is a high voltage storage battery for driving a motor for traveling.
  • vehicle-mounted devices other than a traveling motor such as an electronic control unit (ECU), a power window, an air conditioner, a lighting, and an audio device are called auxiliary devices.
  • ECU electronice control unit
  • auxiliary devices These accessories operate at low voltage. Therefore, a DC-DC converter is provided which steps down the output voltage of the traction battery and converts it to the operation power supply voltage of the accessory.
  • an automobile powered by an internal combustion engine includes an alternator that generates electric power by driving the internal combustion engine. And the power supply voltage for operation is supplied to the auxiliary equipment by the generated power of the alternator.
  • a lead storage battery is connected to a power supply line for auxiliary equipment. And the lead storage battery is always charged by the voltage of the power supply line. And when power supply from a traction battery or an alternator runs short, electric power is supplied to an auxiliary machine from a lead storage battery via a power supply line. As described above, when the power supplied from the traction battery or the alternator runs short, a storage battery that supplies power to the auxiliary device is referred to as an auxiliary battery.
  • the lead storage battery has a characteristic that the change of the output voltage with respect to the state of charge (SOC: State Of Charge) is small and the output voltage is flat. Therefore, conventionally, it has been possible to connect a DC-DC converter or an alternator directly to a lead storage battery to perform constant voltage charging.
  • SOC State Of Charge
  • the lithium ion battery may be overcharged and deteriorated.
  • a charger DC-DC converter that controls the charging current of the lithium ion battery based on the voltage of the power supply line output from the power supply unit such as a traction battery or alternator (For example, Patent Document 1).
  • the power supply unit such as the DC-DC converter or the alternator breaks down and the power supply voltage decreases. Even in such a case, the current from the lithium ion battery to the power supply line is interrupted by the charger. Therefore, when such a voltage drop is detected, it is necessary to control the operation of the charger to supply current from the lithium ion battery to the power supply line.
  • An object of the present invention is to provide a power supply system for a vehicle in which it is easy to shorten the time until the supply of voltage from the storage battery to the power supply line is started when the supply voltage from the power supply unit to the power supply line decreases. It is.
  • a vehicle power supply system is configured using a power supply unit that supplies a power supply voltage of a preset setting voltage to a power supply line, and a lithium ion battery, and has a full charge voltage higher than the preset voltage.
  • a storage battery a charging unit for charging the storage battery based on a power supply voltage output from the power supply unit, and a plurality of diodes connected in series, the plurality of diodes being directed from the storage battery to the power supply line Connected between the storage battery and the power supply line so as to be in a forward direction, the total of the on-state voltages of the respective diodes is equal to or greater than the difference between the set voltage and the full charge voltage of the storage battery The difference between the lower limit value of the target voltage range preset as the voltage to be supplied to the line and the full charge voltage is not satisfied.
  • FIG. 1 is a circuit diagram showing an example of a power supply system for a vehicle according to a first embodiment of the present invention.
  • the vehicle power supply system 1 shown in FIG. 1 includes a power supply unit 2, a storage battery 3, a charger 4 (charging unit), an ECU 5, a current detection unit 7, a voltage detection unit 8, diodes D1 to D6, a switching element SW1, and an operation switch. It has SW0.
  • the power supply system 1 for vehicles is mounted in vehicles, such as EV and HEV. Then, the vehicle power supply system 1 supplies power to the traveling drive motor in the vehicle and the accessory.
  • the accessory includes a vehicle ECU 10 that controls the vehicle and an ECU 5.
  • the power supply unit 2 includes a DC / DC converter 21 and a battery pack 22.
  • produces by the drive of an internal combustion engine is used as the power supply part 2, for example.
  • the battery pack 22 includes a traction battery TB and contactors CT1 to CT4.
  • the traction battery TB is an assembled battery configured by combining, for example, a plurality of lithium ion batteries, nickel hydrogen secondary batteries, and the like.
  • the traction battery TB is configured to output, for example, 350V.
  • the positive electrode (+) of the traction battery TB is connected to the DC / DC converter 21 via the contactor CT1.
  • the negative electrode (-) of the traction battery TB is connected to the DC / DC converter 21 via the contactor CT2.
  • the positive electrode (+) of the traction battery TB is connected to an unillustrated inverter via a contactor CT3
  • the negative electrode (-) of the traction battery TB is connected to an unillustrated inverter via a contactor CT4.
  • the inverter drives a power motor for traveling the vehicle based on the power supplied from the traction battery TB.
  • the contactors CT1 to CT4 are opened and closed in response to a control signal from the vehicle ECU 10.
  • the contactors CT1 to CT4 are off (open).
  • the contactors CT1 to CT4 are turned off (opened), thereby cutting off the supply of the power supply voltage from the traction battery TB to the DC / DC converter 21 or the inverter. Leakage current is prevented when the vehicle is at rest (off).
  • the output voltage of the traction battery TB is a high voltage
  • the contactors CT1 to CT4 are turned on (closed) by the vehicle ECU 10.
  • the power supply voltage is supplied from the traction battery TB to the DC / DC converter 21 and the inverter.
  • the DC / DC converter 21 steps down the output voltage of the traction battery TB to a power supply voltage at which the accessory can operate. Then, the DC / DC converter 21 supplies the stepped down voltage to the accessory via the power supply line PL.
  • the voltage applied to the power supply line PL is referred to as a voltage (+ BAT).
  • auxiliary devices such as the vehicle ECU 10 and the ECU 5 are operable at a power supply voltage in the range of 8V to 16V. Therefore, in the vehicle power supply system 1, a target voltage range which is a voltage to be supplied to the power supply line PL is set to, for example, 8V to 16V.
  • a voltage within a target voltage range is preset as a set voltage Vs.
  • the set voltage Vs is set to 12 V, for example.
  • the DC / DC converter 21 outputs the set voltage Vs, that is, 12 V to the power supply line PL.
  • the storage battery 3 is configured, for example, by connecting four lithium ion batteries in series.
  • the discharge termination voltage of a one-cell lithium ion battery is about 2.75V.
  • the full charge voltage of the lithium ion battery of one cell is about 4V.
  • the discharge termination voltage of the entire storage battery 3 is from 2.75 V ⁇ 4 to about 11 V, and the full charge voltage of the entire storage battery 3 is from 4 V ⁇ 4 to about 16 V.
  • the output voltage range in which storage battery 3 can be used is about 11V to about 16V.
  • Charger 4 generates a charge current for charging storage battery 3 from the voltage (+ BAT) of power supply line PL.
  • the charger 4 is, for example, a step-up / step-down DC / DC converter capable of performing boosting and bucking.
  • the ECU 5 boosts the voltage (+ BAT) by the charger 4 to set the charging current of the preset current value to the charger 4 To the storage battery 3.
  • the ECU 5 steps down the voltage (+ BAT) by the charger 4 to charge the charging current of the preset current value Ic. Supply the battery 4 to the storage battery 3.
  • the charger 4 is configured to charge the storage battery 3 at a constant current.
  • the charger 4 includes, for example, a field effect transistor (FET) 41, a diode 42, an insulating transformer 43, and a diode 44.
  • the power supply line PL is connected to one end of the primary coil of the transformer 43.
  • the other end of the primary coil of the transformer 43 is connected to the circuit ground via the FET 41.
  • a diode (parasitic diode) 42 is connected between both ends of the FET 41.
  • One end of the secondary coil of the transformer 43 is connected to the circuit ground.
  • the other end of the secondary coil of the transformer 43 is connected to the anode of the diode 44.
  • the anode of the diode 44 is connected to the positive electrode of the storage battery 3 via the current detection unit 7.
  • the current detection unit 7 is configured of, for example, a current sensor such as a shunt resistor or a Hall element.
  • the current detection unit 7 detects the charge / discharge current value of the storage battery 3 and outputs a signal indicating the detected current value to the ECU 5.
  • the current detection unit 7 indicates the charging current flowing in the direction of charging the storage battery 3 by a positive current value, and indicates the discharging current flowing in the direction of discharging the storage battery 3 by a negative current value.
  • the diodes D1 to D6 are connected in series so that the direction from the storage battery 3 toward the power supply line PL is forward.
  • the cathode of the diode D1 is connected to the power supply line PL, and the anode of the diode D6 is connected to the positive electrode of the storage battery 3 via the current detection unit 7.
  • One on-state voltage of the diodes D1 to D6 is, for example, 0.7V.
  • the total of the on voltages of the diodes D1 to D6 is 4.2V.
  • the set voltage Vs is 12 V and the full charge voltage of the storage battery 3 is about 16 V
  • the sum of the on voltages of the diodes D1 to D6 exceeds the difference between the set voltage Vs and the full charge voltage of the storage battery 3 Become.
  • the lower limit value of the target voltage range is 8V. Therefore, the total of the on-state voltages of the diodes D1 to D6 is a voltage less than 8 V which is the difference between the lower limit value of the target voltage range and the full charge voltage of the storage battery 3. That is, when the potential difference between the voltage (+ BAT) of the power supply line PL and the output voltage of the storage battery 3 becomes 4.2 V or more, the diodes D1 to D6 turn on.
  • DC / DC converter 21 breaks down and power supply unit 2 can not supply power supply voltage to power supply line PL. If the voltage (+ BAT) falls below the lower limit value of the target voltage range, that is, before the auxiliaries stop operating, diodes D1 to D6 are turned on and the output voltage of storage battery 3 is applied to power supply line PL. .
  • a control circuit such as the ECU 5 is used to detect an abnormality, and a charger performs control to reverse current.
  • the supply voltage from the power supply unit 2 to the power supply line PL decreases, it is possible to shorten the time until the voltage supply from the storage battery 3 to the power supply line PL is started.
  • connection point P1 between the diode D1 and the diode D2 is connected to the positive electrode of the storage battery 3 via the switching element SW1 and the current detection unit 7.
  • the switching element SW1 for example, a transistor such as a FET or a switching element such as a relay switch is used.
  • the switching element SW1 is turned on (closed) and turned off (opened) in accordance with a control signal from the ECU 5.
  • the switching element SW1 may be provided so as to short the remaining diodes except one of the diodes D1 to D6.
  • the switching element SW1 is provided between the cathode of the diode D1 and the anode of the diode D5. May be
  • the voltage detection unit 8 is configured using, for example, an analog-to-digital converter or the like.
  • the voltage detection unit 8 detects a voltage (+ BAT) and outputs a signal indicating the voltage (+ BAT) to the ECU 5.
  • the ECU 5 is, for example, a CPU (Central Processing Unit), a ROM (Read) Only memory, RAM (Random Access Memory), timer circuit, and peripheral circuits thereof are used. Then, the ECU 5 functions as the determination unit 51 and the control unit 52 by executing, for example, a control program stored in the ROM.
  • a CPU Central Processing Unit
  • ROM Read Only memory
  • RAM Random Access Memory
  • the ECU 5 is provided with power supply terminals 53 and 54.
  • the power supply terminal 53 is connected to the power supply line PL. Therefore, the voltage (+ BAT) is supplied to the power supply terminal 53.
  • the power supply terminal 54 is connected to one end of the operation switch SW0, and the other end of the operation switch SW0 is connected to the positive electrode of the storage battery 3 via the current detection unit 7. Therefore, when the operation switch SW0 is turned on, the output voltage Vout is supplied from the storage battery 3 to the power supply terminal 54 through the current detection unit 7 and the operation switch SW0.
  • the operation switch SW0 is, for example, a push button switch that can be operated by the user.
  • the ECU 5 that is, the determination unit 51 and the control unit 52 operate with the power supply voltage received by one of the power supply terminals 53 and 54.
  • the control unit 52 monitors the current value detected by the current detection unit 7. Then, the control unit 52 controls the on / off of the FET 41 so that the current value detected by the current detection unit 7 becomes the set current value Ic. Thereby, the control unit 52 causes the charger 4 to perform constant current charging of the storage battery 3. Further, when it is detected that the terminal voltage of the storage battery 3 has become a full charge voltage, for example, by the voltage detection circuit (not shown), the control unit 52 stops the constant current charging by the charger 4.
  • determination unit 51 determines that the current value detected by current detection unit 7 is a negative value, that is, storage battery 3 is in a discharged state, power supply to power supply line PL by power supply unit 2 is insufficient. It is determined that
  • the determination unit 51 monitors the voltage (+ BAT) detected by the voltage detection unit 8, and when the voltage (+ BAT) falls below a preset threshold voltage Vth, the power supply to the power supply line PL by the power supply unit 2 is performed. It may be determined that the supply is insufficient.
  • the threshold voltage Vth is a voltage lower than the set voltage Vs, for example, 8 V which is the lower limit value of the target voltage range.
  • the determination unit 51 is satisfied. It may be determined that the power supply to the power supply line PL by the power supply unit 2 is insufficient. In this case, the determination accuracy of the power supply shortage to the power supply line PL due to the failure or the like of the power supply unit 2 is improved.
  • the control unit 52 turns on the switching element SW1.
  • forward voltage drop in diode D1 to D6 is approximately equal to the total on voltage, ie, a voltage of about 4.2 V There is a descent. As a result, a power loss corresponding to the product of the voltage drop across the diodes D1 to D6 and the current flow occurs.
  • control unit 52 causes the diodes D2 to D6 to bypass the output current of the storage battery 3 by turning on the switching element SW1.
  • the power loss is a product of the voltage drop of about 0.7 V and the current generated in the diode D1, the power loss generated by the diodes D1 to D6 can be reduced.
  • the forward voltage generated in the diodes D1 to D6 increases as the current flowing through the diodes increases, and thus does not necessarily coincide with the sum of the on voltages of the respective diodes. However, in the following description, it is assumed that the sum of the forward voltage generated at the diodes D1 to D6 and the on voltage of each diode is approximately equal.
  • the diodes D1 to D6 turn on when the voltage (+ BAT) decreases to 6.8 V.
  • the ECU 5 starts operation.
  • the determination unit 51 determines that the power supply by the power supply unit 2 is insufficient, and the control unit 52 turns on the switching element SW1.
  • FIG. 2 is a timing chart showing an example of the operation of the vehicular power supply system 1 shown in FIG.
  • the vertical axis shows voltage
  • the horizontal axis shows the passage of time.
  • the solid line indicates the voltage (+ BAT)
  • the alternate long and short dash line indicates the output voltage Vout of the storage battery 3.
  • the storage battery 3 is fully charged, and the output voltage Vout is 16V.
  • the power supply unit 2 operates normally, and the voltage (+ BAT) is 12 V by the output voltage from the power supply unit 2.
  • the difference between the output voltage Vout and the voltage (+ BAT) is 4 V, which is less than 4.2 V which is the total of the on-voltages of the diodes D1 to D6. Therefore, the diodes D1 to D6 are off, and the storage battery 3 is not discharged.
  • timing T2 when the voltage output from the power supply unit 2 disappears, for example, because the DC / DC converter 21 breaks down, the voltage (+ BAT) drops sharply. Then, the difference between the output voltage Vout and the voltage (+ BAT) exceeds 4.2 V, and the diodes D1 to D6 are turned on (timing T2).
  • the current value detected by the current detection unit 7 becomes a negative value, which indicates that the storage battery 3 is discharged. Then, the determination unit 51 determines that the power supply by the power supply unit 2 is insufficient, and the control unit 52 turns on the switching element SW1 (timing T3).
  • Vehicle power supply system 1a shown in FIG. 3 differs from vehicle power supply system 1 shown in FIG. 1 in that DC / DC converter 21a outputs 10 V to power supply line PL as set voltage Vs. Further, in the power supply system 1a for a vehicle, nine diodes D1 to D9 are connected in series, and the total on voltage of the diodes D1 to D9 is 6.3 V. Different from system 1
  • Vehicle power supply system 1a is different from vehicle power supply system 1 in that charger 6 is used instead of charger 4 which is a buck-boost converter.
  • the charger 6 is a step-up DC / DC converter that generates a charging current for charging the storage battery 3 by boosting a voltage (+ BAT).
  • the charger 6 includes a coil 61, an FET 62, and diodes 63 and 64.
  • One end of the coil 61 is connected to the power supply line PL, and the other end is connected to the anode of the diode 64.
  • the cathode of the diode 64 is connected to the positive electrode of the storage battery 3 via the current detection unit 7.
  • the anode of the diode 64 is connected to the circuit ground via the FET 62.
  • a diode (parasitic diode) 63 is connected between both ends of the FET 62.
  • the set voltage Vs that is, the voltage (+ BAT) is lower than the discharge termination voltage of the storage battery 3 as long as the power supply unit 2a operates normally. Therefore, the charger 6 does not need to step down the voltage (+ BAT). As a result, a step-up type DC / DC converter that can be realized with a simpler configuration than the charger 4 and therefore cost less than the charger 4 can be used as the charger 6.
  • the set voltage Vs may be a voltage within the power supply voltage range in which the accessory can operate, that is, a voltage within the target voltage range, and is not limited to 12 V and 10 V.
  • FIG. 4 is a circuit diagram showing an example of the configuration of a vehicular power supply system 1b according to a second embodiment of the present invention.
  • the vehicle power supply system 1b shown in FIG. 4 differs from the vehicle power supply system 1 shown in FIG. 1 in the following points.
  • the vehicle power supply system 1b includes switching elements SW2 to SW5 in addition to the switching element SW1.
  • the connection point P2 between the diode D2 and the diode D3 is connected to the positive electrode of the storage battery 3 via the switching element SW2 and the current detection unit 7, and the connection point P3 between the diode D3 and the diode D4 is current detection from the switching element SW3
  • the junction point P4 of the diode D4 and the diode D5 is connected to the positive pole of the storage battery 3 via the switching element SW4 and the current detection unit 7, and the diode D5 and the diode D6 are connected.
  • the connection point P5 between the two is connected to the positive electrode of the storage battery 3 via the switching element SW5 and the current detection unit 7.
  • switching elements SW1 to SW5 for example, transistors such as FETs and switching elements such as relay switches are used.
  • the switching elements SW1 to SW5 are turned on (closed) and off (opened) in accordance with the control signal from the ECU 5, respectively.
  • the switching elements SW1 to SW5 correspond to an example of a short circuit part.
  • the ECU 5 b does not include the determination unit 51. Further, the ECU 5 b includes a control unit 52 b instead of the control unit 52.
  • control unit 52b sequentially selects voltage (+ BAT) from switching element SW5 corresponding to connection point P5 positioned closest to storage battery 3.
  • the switching elements SW5 to SW1 are sequentially turned on until the voltage V.sub.s becomes equal to or higher than the set voltage V.sub.s.
  • the control unit 52b When the voltage (+ BAT) falls below the threshold voltage Vth, the control unit 52b turns on the switching elements SW5 to SW1 one by one to thereby reduce the number of diodes shorted, that is, the number of diodes whose current is bypassed. Should be increased sequentially. Therefore, the order in which the control unit 52b turns on the switching elements SW5 to SW1 is not limited to a specific order.
  • control unit 52b sets a time from turning on one switching element to turning on the next switching element to be equal to or longer than a preset setting time ts. .
  • the set time ts becomes longer, the rising speed of the voltage (+ BAT) by sequentially turning on the switching elements SW5 to SW1 becomes slower. On the other hand, if the voltage (+ BAT) rises rapidly, the accessory may malfunction. Therefore, a value of the set time ts that allows stable operation of the auxiliary machine without malfunctioning is obtained, for example, experimentally, and set in advance as the set time ts.
  • the other configuration is the same as that of the power supply system 1 for a vehicle shown in FIG.
  • FIG. 5 is a timing chart showing an example of the operation of the vehicular power supply system 1b shown in FIG.
  • the vertical axis shows voltage, and the horizontal axis shows the passage of time.
  • the solid line indicates the voltage (+ BAT), and the alternate long and short dash line indicates the output voltage Vout of the storage battery 3.
  • the output voltage Vout of the storage battery 3 is 15V.
  • the power supply unit 2 operates normally, and the voltage (+ BAT) is 12 V by the output voltage from the power supply unit 2.
  • the difference between the output voltage Vout and the voltage (+ BAT) is 3 V, which is less than 4.2 V which is the total of the on-voltages of the diodes D1 to D6. Therefore, the diodes D1 to D6 are off.
  • timing T2 when the voltage output from the power supply unit 2 disappears, for example, because the DC / DC converter 21 breaks down, the voltage (+ BAT) drops sharply. Then, the difference between the output voltage Vout and the voltage (+ BAT) exceeds 4.2 V, and the diodes D1 to D6 are turned on (timing T2).
  • the control unit 52b maintains the state in which the switching element SW4 is turned on without turning on the subsequent switching elements SW3, SW2, and SW1. Then, the voltage (+ BAT) is maintained at 12.2V.
  • the accessory can operate in the power supply voltage range of 8 V to 16 V, for example, the operation of the accessory is generally performed when the voltage (+ BAT) of the set voltage Vs is normally output from the power supply unit 2 Most stable.
  • Vehicle power supply system 1c shown in FIG. 6 differs from vehicle power supply system 1b shown in FIG. 4 in that DC / DC converter 21a outputs 10 V to power supply line PL as set voltage Vs. Further, in the power supply system 1c for a vehicle, nine diodes D1 to D9 are connected in series, and the total on voltage of the diodes D1 to D9 is 6.3 V. Thus, the power supply for a vehicle shown in FIG. Different from system 1b.
  • Vehicle power supply system 1c is different from vehicle power supply system 1b in that charger 6 is used instead of charger 4 which is a buck-boost converter.
  • the set voltage Vs that is, the voltage (+ BAT) is lower than the discharge termination voltage of the storage battery 3 as long as the power supply unit 2a operates normally. Therefore, the charger 6 does not need to step down the voltage (+ BAT). As a result, as the charger 6, it is possible to use a step-up DC / DC converter that can be realized with a simpler configuration than the charger 4 and therefore cost less than the charger 4.
  • the vehicle power supply system is configured using a power supply unit that supplies a power supply voltage of a preset setting voltage to the power supply line, and a lithium ion battery, and a full charge voltage higher than the preset voltage.
  • a charging unit for charging the storage battery based on the power supply voltage output from the power supply unit, and a plurality of diodes connected in series, the plurality of diodes being directed from the storage battery to the power supply line Connected between the storage battery and the power supply line such that the direction is forward, the total of the on-state voltages of the respective diodes is equal to or greater than the difference between the set voltage and the full charge voltage of the storage battery; The difference between the lower limit value of the target voltage range preset as the voltage to be supplied to the power supply line and the full charge voltage is not satisfied.
  • the power supply unit when the power supply unit is operating normally, supplies the power supply voltage of the preset voltage set to the power supply line. Further, a plurality of diodes are connected in series between the storage battery and the power supply line. The sum of the on-state voltages of the respective diodes is equal to or greater than the set voltage, ie, the difference between the voltage of the power supply line and the full charge voltage of the storage battery. Therefore, even if the charging unit fully charges the storage battery, the plurality of diodes remain off. As a result, the charging current from the charging unit is prevented from flowing out to the power supply line through the plurality of diodes, and the power loss due to the outflow of the charging current is prevented.
  • the total of the on-state voltages of the respective diodes does not satisfy the difference between the lower limit value of the target voltage range preset as the voltage to be supplied to the power supply line and the full charge voltage of the storage battery. Therefore, when the power supply unit does not operate normally and the power supply voltage drops, a plurality of diodes are turned on before the voltage of the power supply line falls below the lower limit of the target voltage range, and a voltage is supplied from the storage battery to the power supply line . In this case, the control time for the operation control of the charger, which is required in the background art, is not necessary to start discharging the storage battery. Therefore, when the supply voltage from the power supply unit to the power supply line is reduced, it is easy to shorten the time until the voltage supply from the storage battery to the power supply line is started.
  • a switching element that shorts the remaining diodes except one of the plurality of diodes, a determination unit that determines presence or absence of a shortage in supply of the power supply voltage by the power supply unit, and a shortage of the supply by the determination unit It is preferable to include a control unit that turns on the switching element when it is determined that there is a.
  • the determination unit determines that the supply of the power supply voltage is insufficient.
  • the voltage of the power supply line is lowered to turn on the plurality of diodes, and a current is supplied from the storage battery to the power supply line.
  • a forward voltage drop occurs and a power loss occurs.
  • the control unit turns on the switching element when the determination unit determines that the supply of the power supply voltage is insufficient.
  • the discharge current of the storage battery bypasses the other diode leaving one diode. This reduces the voltage drop across the diode and reduces power dissipation.
  • the switching element is turned on, one diode remains between the storage battery and the power supply line, so that backflow from the power supply line to the storage battery is prevented.
  • a current detection unit for detecting the charge and discharge current of the storage battery is further provided, and the determination unit has the shortage of the supply when the charge and discharge current detected by the current detection unit is a current in the discharge direction. It is preferable to determine
  • the determination unit can determine that there is a shortage of power supply.
  • the voltage detection unit further includes a voltage detection unit that detects the voltage of the power supply line, and the determination unit determines that the voltage detected by the voltage detection unit falls below a threshold voltage preset to a voltage that does not meet the set voltage. In this case, it may be determined that there is a shortage of the supply.
  • the determination unit can determine that there is a shortage of power supply.
  • the number of the diodes is three or more, and a voltage detection unit for detecting the voltage of the power supply line and any one of the plurality of diodes can be short-circuited and the number of diodes short-circuited can be changed.
  • the voltage detector detects the number of diodes short-circuited by the short circuit and the number of diodes shorted by the short circuit when the voltage detected by the voltage detector falls below a threshold voltage preset to a voltage less than the set voltage. It is preferable to include a control unit that sequentially increases the detected voltage until it reaches the set voltage or more.
  • the control unit sequentially increases the number of diodes short-circuited by the short circuit. Then, as the number of shorted diodes increases, the number of diodes to which the discharge current bypasses increases and the voltage drop decreases.
  • the voltage detected by the voltage detection unit that is, the voltage of the power supply line rises.
  • the control unit sequentially increases the number of diodes shorted by the shorting unit until the voltage of the power supply line becomes equal to or higher than the set voltage, and increases the number of diodes shorted further when the voltage of the power supply line becomes equal to or higher than the set voltage. I will not let you. Therefore, the voltage of the power supply line is maintained at a voltage slightly higher than the set voltage. As a result, even when the power supply is insufficient due to a failure of the power supply unit or the like, the voltage of the power supply line can be maintained at a voltage close to the set voltage.
  • control unit may set a time from the short-circuiting of one diode to the short-circuiting of the next diode not less than a preset setting time. It is preferable to do.
  • the control unit When the control unit shorts the plurality of diodes sequentially, the voltage of the power supply line rises. However, the load receiving the supply of the power supply voltage from the power supply line is likely to become unstable in operation if the power supply voltage rises rapidly. Therefore, when sequentially short-circuiting a plurality of diodes, the control unit allows a time longer than a preset setting time to short-circuit one diode and then short-circuit the next diode. Slowly raise the line voltage. As a result, the stability of the operation of the load receiving the supply of the power supply voltage from the power supply line is improved.
  • the control unit may further operate using the power supply voltage as a power supply voltage for operation, and the operation switch may output an output voltage of the storage battery when the operation switch is operated. It is preferable to supply as an operation power supply voltage of the control unit.
  • the control unit does not operate with the voltage of the power supply line due to the voltage drop due to the diode. Also, the user can activate the control unit by operating the operation switch.
  • the set voltage is 12 V
  • the charging unit is a buck-boost converter capable of stepping up and down the power supply voltage.
  • the set voltage may be a voltage lower than a discharge termination voltage preset as a voltage to stop the discharge of the storage battery, and the charging unit may be a boost converter capable of boosting the power supply voltage.
  • the power supply voltage of the power supply line does not become higher than the output voltage of the storage battery. Therefore, since the charging unit does not need to step down the power supply voltage, the charging unit can be configured by a boost converter. Then, the cost can be reduced as compared to the case where the charging unit is configured by a buck-boost converter.
  • the power supply system for vehicles which concerns on this invention is useful as a power supply system for vehicles using the storage battery mounted in a vehicle.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Power Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Secondary Cells (AREA)
  • Battery Mounting, Suspending (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)

Abstract

A vehicle power-supply system provided with the following: a power-supply unit that provides a preset power-supply voltage to a power-supply line; a rechargeable battery that comprises a lithium-ion battery and has a fully-charged voltage that is higher than the aforementioned power-supply voltage; a charging unit that uses the power-supply voltage outputted by the power-supply unit to charge the rechargeable battery; and a plurality of diodes connected in series. Said diodes are connected between the rechargeable battery and the abovementioned power-supply line such that the forward direction of said diodes runs from the rechargeable battery towards the power-supply line. The total forward voltage drop of the diodes is greater than or equal to the difference between the power-supply voltage and the fully-charged voltage of the rechargeable battery but less than the difference between the lower limit of a preset target voltage range, where said voltage range indicates the voltage that should be supplied to the power-supply line, and the fully-charged voltage of the rechargeable battery.

Description

車両用電源システムVehicle power system
　本発明は、車両に搭載される蓄電池を用いた車両用電源システムに関する。 The present invention relates to a vehicle power supply system using a storage battery mounted on a vehicle.
　電気自動車（EV：Electric Vehicle）やハイブリッド自動車（HEV : Hybrid Electric Vehicle）は、走行用のモータを駆動するための高電圧の蓄電池であるトラクションバッテリを搭載している。また、ＥＣＵ（Electronic Control Unit）、パワーウィンド、エアコン、照明、及びオーディオ機器等、走行用のモータ以外の車載機器は、補機と呼ばれている。これらの補機は、低電圧で動作する。そのため、トラクションバッテリの出力電圧を降圧して、補機の動作用電源電圧に変換するＤＣ－ＤＣコンバータを備えている。 An electric vehicle (EV: Electric Vehicle) or a hybrid vehicle (HEV: Hybrid Electric Vehicle) is equipped with a traction battery which is a high voltage storage battery for driving a motor for traveling. In addition, vehicle-mounted devices other than a traveling motor such as an electronic control unit (ECU), a power window, an air conditioner, a lighting, and an audio device are called auxiliary devices. These accessories operate at low voltage. Therefore, a DC-DC converter is provided which steps down the output voltage of the traction battery and converts it to the operation power supply voltage of the accessory.
　一方、内燃機関を動力とする自動車では、内燃機関の駆動により発電するオルタネータを備えている。そして、オルタネータの発電電力によって、補機へ動作用電源電圧を供給するようになっている。 On the other hand, an automobile powered by an internal combustion engine includes an alternator that generates electric power by driving the internal combustion engine. And the power supply voltage for operation is supplied to the auxiliary equipment by the generated power of the alternator.
　ＥＶ、ＨＥＶ、及び内燃機関を動力とする自動車等の車両では、上述のＤＣ―ＤＣコンバータやオルタネータが故障すると、補機用の低電圧の電源電圧が供給できなくなる結果、ＥＣＵその他の補機が全く動作しなくなり、不都合である。 In vehicles such as EVs, HEVs, and vehicles powered by internal combustion engines, if the above-mentioned DC-DC converter or alternator fails, the low-voltage power supply voltage for auxiliary equipment can not be supplied, resulting in ECUs and other auxiliary equipment. It does not work at all and is inconvenient.
　そこで、これらの車両では、補機用の電源ラインに鉛蓄電池が接続されている。そして、電源ラインの電圧によって、常時鉛蓄電池が充電されている。そして、トラクションバッテリやオルタネータからの供給電力が不足した場合に、鉛蓄電池から電源ラインを介して補機へ電力が供給されるようになっている。このように、トラクションバッテリやオルタネータからの供給電力が不足した場合に、補機へ電力を供給する蓄電池を補機バッテリと称する。 Therefore, in these vehicles, a lead storage battery is connected to a power supply line for auxiliary equipment. And the lead storage battery is always charged by the voltage of the power supply line. And when power supply from a traction battery or an alternator runs short, electric power is supplied to an auxiliary machine from a lead storage battery via a power supply line. As described above, when the power supplied from the traction battery or the alternator runs short, a storage battery that supplies power to the auxiliary device is referred to as an auxiliary battery.
　しかしながら、鉛蓄電池は、体積が大きく且つ重量も重い。そこで、補機バッテリとして、鉛蓄電池よりも小型軽量化が容易なリチウムイオン電池（リチウムイオン二次電池）を用いることが検討されている（例えば、特許文献１、及び特許文献２）。 However, lead acid batteries are bulky and heavy. Then, using a lithium ion battery (lithium ion secondary battery) whose size and weight can be reduced more easily than a lead storage battery is examined as an auxiliary battery (for example, Patent Document 1 and Patent Document 2).
　ところで、鉛蓄電池は充電状態（ＳＯＣ：State Of Charge）に対する出力電圧の変化が少なく、出力電圧がフラットな特性を有している。そのため、従来、ＤＣ―ＤＣコンバータやオルタネータを直接鉛蓄電池に接続して定電圧充電することが可能であった。 By the way, the lead storage battery has a characteristic that the change of the output voltage with respect to the state of charge (SOC: State Of Charge) is small and the output voltage is flat. Therefore, conventionally, it has been possible to connect a DC-DC converter or an alternator directly to a lead storage battery to perform constant voltage charging.
　一方、リチウムイオン電池は、ＳＯＣの変化に対する出力電圧の変化が大きい。そのため、上述のＤＣ―ＤＣコンバータから出力される一定の電源電圧を直接リチウムイオン電池に印加すると、リチウムイオン電池が低ＳＯＣのときは、電源電圧とリチウムイオン電池の出力電圧との差が大きいために、リチウムイオン電池に大電流が流れて電池を劣化させてしまう。 On the other hand, in lithium ion batteries, the change in output voltage with respect to the change in SOC is large. Therefore, when a constant power supply voltage output from the above DC-DC converter is directly applied to a lithium ion battery, when the lithium ion battery has a low SOC, the difference between the power supply voltage and the output voltage of the lithium ion battery is large. In addition, a large current flows in the lithium ion battery to deteriorate the battery.
　また、オルタネータに直接リチウムイオン電池を接続した場合においても、オルタネータで発電された電力が直接リチウムイオン電池に充電されると、リチウムイオン電池が過充電されて劣化するおそれがある。 Further, even when the lithium ion battery is directly connected to the alternator, if the power generated by the alternator is directly charged to the lithium ion battery, the lithium ion battery may be overcharged and deteriorated.
　そのため、補機バッテリとしてリチウムイオン電池を用いるときは、トラクションバッテリやオルタネータ等の電源部から出力される電源ラインの電圧に基づき、リチウムイオン電池の充電電流を制御する充電器（ＤＣ―ＤＣコンバータ）を備える必要がある（例えば、特許文献１）。 Therefore, when using a lithium ion battery as an auxiliary battery, a charger (DC-DC converter) that controls the charging current of the lithium ion battery based on the voltage of the power supply line output from the power supply unit such as a traction battery or alternator (For example, Patent Document 1).
　しかしながら、リチウムイオン電池が電源ラインに直接接続されておらず、電源ラインとリチウムイオン電池との間に充電器が介在すると、ＤＣ―ＤＣコンバータやオルタネータ等の電源部が故障して電源電圧が低下した場合であっても、リチウムイオン電池から電源ラインへ向かう電流は充電器によって遮断されてしまう。そのため、このような電圧低下を検知した場合、リチウムイオン電池から電源ラインへ向かって電流を供給させるように充電器の動作を制御する必要がある。 However, if the lithium ion battery is not directly connected to the power supply line and a charger intervenes between the power supply line and the lithium ion battery, the power supply unit such as the DC-DC converter or the alternator breaks down and the power supply voltage decreases. Even in such a case, the current from the lithium ion battery to the power supply line is interrupted by the charger. Therefore, when such a voltage drop is detected, it is necessary to control the operation of the charger to supply current from the lithium ion battery to the power supply line.
　そうすると、電源ラインの電圧が低下してからリチウムイオン電池による電圧供給が開始されるまでに、充電器の動作制御のための制御時間が必要となる結果、リチウムイオン電池による電圧供給が開始されるまでの間に瞬時停電が生じるという、不都合があった。 Then, since the control time for the operation control of the charger is required until the voltage supply by the lithium ion battery is started after the voltage of the power supply line decreases, the voltage supply by the lithium ion battery is started In the meantime, there was a disadvantage that a momentary power failure would occur.
特開２００４－２２９４７８号公報Japanese Patent Laid-Open No. 2004-229478 実用新案登録第３１３４９５０号公報Utility model registration 3134950 gazette
　本発明の目的は、電源部からの電源ラインへの供給電圧が低下した場合に、蓄電池から電源ラインへ電圧供給が開始されるまでの時間を短縮することが容易な車両用電源システムを提供することである。 An object of the present invention is to provide a power supply system for a vehicle in which it is easy to shorten the time until the supply of voltage from the storage battery to the power supply line is started when the supply voltage from the power supply unit to the power supply line decreases. It is.
　本発明の一局面に従う車両用電源システムは、予め設定された設定電圧の電源電圧を電源ラインへ供給する電源部と、リチウムイオン電池を用いて構成され、前記設定電圧より高い満充電電圧を有する蓄電池と、前記電源部から出力された電源電圧に基づき前記蓄電池を充電する充電部と、直列接続された複数のダイオードとを備え、前記複数のダイオードは、前記蓄電池から前記電源ラインへ向かう方向が順方向になるように、前記蓄電池と前記電源ラインとの間に接続され、前記各ダイオードのオン電圧の合計は、前記設定電圧と前記蓄電池の満充電電圧との差以上であり、かつ前記電源ラインに供給されるべき電圧として予め設定された目標電圧範囲の下限値と前記満充電電圧との差に満たない。 A vehicle power supply system according to one aspect of the present invention is configured using a power supply unit that supplies a power supply voltage of a preset setting voltage to a power supply line, and a lithium ion battery, and has a full charge voltage higher than the preset voltage. A storage battery, a charging unit for charging the storage battery based on a power supply voltage output from the power supply unit, and a plurality of diodes connected in series, the plurality of diodes being directed from the storage battery to the power supply line Connected between the storage battery and the power supply line so as to be in a forward direction, the total of the on-state voltages of the respective diodes is equal to or greater than the difference between the set voltage and the full charge voltage of the storage battery The difference between the lower limit value of the target voltage range preset as the voltage to be supplied to the line and the full charge voltage is not satisfied.
本発明の第１実施形態に係る車両用電源システムの一例を示す回路図である。It is a circuit diagram showing an example of the power supply system for vehicles concerning a 1st embodiment of the present invention. 図１に示す車両用電源システムの動作の一例を示すタイミングチャートである。It is a timing chart which shows an example of operation of a power supply system for vehicles shown in Drawing 1. 図１に示す車両用電源システムの変形例を示す回路図である。It is a circuit diagram which shows the modification of the power supply system for vehicles shown in FIG. 本発明の第２実施形態に係る車両用電源システムの構成の一例を示す回路図である。It is a circuit diagram showing an example of composition of a power supply system for vehicles concerning a 2nd embodiment of the present invention. 図４に示す車両用電源システムの動作の一例を示すタイミングチャートである。It is a timing chart which shows an example of operation of a power supply system for vehicles shown in Drawing 4. 図４に示す車両用電源システムの変形例を示す回路図である。It is a circuit diagram which shows the modification of the power supply system for vehicles shown in FIG.
　以下、本発明に係る実施形態を図面に基づいて説明する。なお、各図において同一の符号を付した構成は、同一の構成であることを示し、その説明を省略する。 Hereinafter, an embodiment according to the present invention will be described based on the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, and abbreviate | omits the description.
　（第１実施形態）
　図１は、本発明の第１実施形態に係る車両用電源システムの一例を示す回路図である。図１に示す車両用電源システム１は、電源部２、蓄電池３、充電器４（充電部）、ＥＣＵ５、電流検出部７、電圧検出部８、ダイオードＤ１～Ｄ６、スイッチング素子ＳＷ１、及び操作スイッチＳＷ０を備えている。車両用電源システム１は、ＥＶやＨＥＶ等の車両に搭載されている。そして、車両用電源システム１は、車両内の走行用駆動モータや、補機に電力を供給する。補機には、車両の制御を行う車両ＥＣＵ１０や、ＥＣＵ５が含まれる。 First Embodiment
FIG. 1 is a circuit diagram showing an example of a power supply system for a vehicle according to a first embodiment of the present invention. The vehicle power supply system 1 shown in FIG. 1 includes a power supply unit 2, a storage battery 3, a charger 4 (charging unit), an ECU 5, a current detection unit 7, a voltage detection unit 8, diodes D1 to D6, a switching element SW1, and an operation switch. It has SW0. The power supply system 1 for vehicles is mounted in vehicles, such as EV and HEV. Then, the vehicle power supply system 1 supplies power to the traveling drive motor in the vehicle and the accessory. The accessory includes a vehicle ECU 10 that controls the vehicle and an ECU 5.
　電源部２は、ＤＣ／ＤＣコンバータ２１と、電池パック２２とを備えている。なお、車両用電源システム１が、内燃機関で走行する車両に搭載される場合には、電源部２として、例えば内燃機関の駆動により発電を行うオルタネータが用いられる。 The power supply unit 2 includes a DC / DC converter 21 and a battery pack 22. In addition, when the power supply system 1 for vehicles is mounted in the vehicle which drive | works with an internal combustion engine, the alternator which generate | occur | produces by the drive of an internal combustion engine is used as the power supply part 2, for example.
　電池パック２２は、トラクションバッテリＴＢと、コンタクタＣＴ１～ＣＴ４とを備えている。トラクションバッテリＴＢは、例えば複数のリチウムイオン電池やニッケル水素二次電池等が組み合わされて構成された組電池である。トラクションバッテリＴＢは、例えば３５０Ｖを出力するようになっている。 The battery pack 22 includes a traction battery TB and contactors CT1 to CT4. The traction battery TB is an assembled battery configured by combining, for example, a plurality of lithium ion batteries, nickel hydrogen secondary batteries, and the like. The traction battery TB is configured to output, for example, 350V.
　トラクションバッテリＴＢの正極（＋）は、コンタクタＣＴ１を介してＤＣ／ＤＣコンバータ２１と接続されている。トラクションバッテリＴＢの負極（－）は、コンタクタＣＴ２を介してＤＣ／ＤＣコンバータ２１と接続されている。 The positive electrode (+) of the traction battery TB is connected to the DC / DC converter 21 via the contactor CT1. The negative electrode (-) of the traction battery TB is connected to the DC / DC converter 21 via the contactor CT2.
　また、トラクションバッテリＴＢの正極（＋）はコンタクタＣＴ３を介して図略のインバータと接続され、トラクションバッテリＴＢの負極（－）はコンタクタＣＴ４を介して図略のインバータと接続されている。インバータは、トラクションバッテリＴＢから供給された電力に基づき、車両走行用の動力モータを駆動する。 Further, the positive electrode (+) of the traction battery TB is connected to an unillustrated inverter via a contactor CT3, and the negative electrode (-) of the traction battery TB is connected to an unillustrated inverter via a contactor CT4. The inverter drives a power motor for traveling the vehicle based on the power supplied from the traction battery TB.
　コンタクタＣＴ１～ＣＴ４は、車両ＥＣＵ１０からの制御信号に応じて開閉される。車両が停止（オフ）状態のときは、コンタクタＣＴ１～ＣＴ４はオフ（開）される。このように、車両が停止（オフ）状態のときはコンタクタＣＴ１～ＣＴ４がオフ（開）されることによって、トラクションバッテリＴＢからＤＣ／ＤＣコンバータ２１やインバータへの電源電圧の供給が遮断される結果、車両が停止（オフ）状態のときに漏れ電流が生じることが防止されている。 The contactors CT1 to CT4 are opened and closed in response to a control signal from the vehicle ECU 10. When the vehicle is in the stop (off) state, the contactors CT1 to CT4 are off (open). As described above, when the vehicle is in the stop (off) state, the contactors CT1 to CT4 are turned off (opened), thereby cutting off the supply of the power supply voltage from the traction battery TB to the DC / DC converter 21 or the inverter. Leakage current is prevented when the vehicle is at rest (off).
　また、トラクションバッテリＴＢの出力電圧は高電圧であるので、車両内に引き回される配線に、トラクションバッテリＴＢの出力電圧が印加されたままになっていると、配線から漏電する可能性が増大する。そこで、車両が停止（オフ）状態のときはコンタクタＣＴ１～ＣＴ４をオフ（開）させることによって、トラクションバッテリＴＢから、ＤＣ／ＤＣコンバータ２１やインバータへ接続される配線に高電圧が印加されない状態にする。これによって、漏電が生じるおそれを低減するようになっている。 In addition, since the output voltage of the traction battery TB is a high voltage, there is an increased possibility of leakage from the wiring if the output voltage of the traction battery TB remains applied to the wiring routed in the vehicle. Do. Therefore, when the vehicle is in the stop (off) state, the contactors CT1 to CT4 are turned off (opened) to prevent the high voltage from being applied to the wiring connected to the DC / DC converter 21 or the inverter from the traction battery TB. Do. This reduces the possibility of leakage.
　また、車両が起動された状態（オン状態）のときは、車両ＥＣＵ１０によって、コンタクタＣＴ１～ＣＴ４がオン（閉）される。これにより、トラクションバッテリＴＢからＤＣ／ＤＣコンバータ２１やインバータへ電源電圧が供給される。その結果、車両の動力モータや補機を動作させることが可能となる。 When the vehicle is in the activated state (on state), the contactors CT1 to CT4 are turned on (closed) by the vehicle ECU 10. As a result, the power supply voltage is supplied from the traction battery TB to the DC / DC converter 21 and the inverter. As a result, it is possible to operate the power motor and the accessory of the vehicle.
　ＤＣ／ＤＣコンバータ２１は、トラクションバッテリＴＢの出力電圧を、補機が動作可能な電源電圧に降圧する。そして、ＤＣ／ＤＣコンバータ２１は、降圧した電圧を、電源ラインＰＬを介して補機へ供給する。以下、電源ラインＰＬに印加されている電圧を、電圧（＋ＢＡＴ）と称する。 The DC / DC converter 21 steps down the output voltage of the traction battery TB to a power supply voltage at which the accessory can operate. Then, the DC / DC converter 21 supplies the stepped down voltage to the accessory via the power supply line PL. Hereinafter, the voltage applied to the power supply line PL is referred to as a voltage (+ BAT).
　例えば車両ＥＣＵ１０やＥＣＵ５等の補機は、電源電圧が、８Ｖ～１６Ｖの範囲で動作可能とされている。従って、車両用電源システム１は、電源ラインＰＬに供給すべき電圧である目標電圧範囲が例えば８Ｖ～１６Ｖに設定されている。ＤＣ／ＤＣコンバータ２１には、目標電圧範囲内の電圧が設定電圧Ｖｓとして予め設定されている。設定電圧Ｖｓは、例えば１２Ｖにされている。ＤＣ／ＤＣコンバータ２１は、設定電圧Ｖｓ、すなわち１２Ｖを電源ラインＰＬへ出力する。 For example, auxiliary devices such as the vehicle ECU 10 and the ECU 5 are operable at a power supply voltage in the range of 8V to 16V. Therefore, in the vehicle power supply system 1, a target voltage range which is a voltage to be supplied to the power supply line PL is set to, for example, 8V to 16V. In the DC / DC converter 21, a voltage within a target voltage range is preset as a set voltage Vs. The set voltage Vs is set to 12 V, for example. The DC / DC converter 21 outputs the set voltage Vs, that is, 12 V to the power supply line PL.
　なお、補機バッテリとして鉛蓄電池を用いる車両が市場に広く流通している。従って、設定電圧Ｖｓを１２Ｖとすれば、車両用電源システム１を既存の車両に適用することが容易である。 In addition, a vehicle using a lead storage battery as an auxiliary battery is widely distributed in the market. Therefore, if the set voltage Vs is 12 V, it is easy to apply the vehicle power supply system 1 to an existing vehicle.
　蓄電池３は、例えばリチウムイオン電池が４個直列接続されて、構成されている。１セルのリチウムイオン電池の放電終止電圧は、約２．７５Ｖである。また、１セルのリチウムイオン電池の満充電電圧は約４Ｖである。そうすると、蓄電池３全体の放電終止電圧は２．７５Ｖ×４から約１１Ｖとなり、蓄電池３全体の満充電電圧は４Ｖ×４から約１６Ｖとなる。そうすると、蓄電池３を利用することが可能な出力電圧範囲は、約１１Ｖ～約１６Ｖとなる。 The storage battery 3 is configured, for example, by connecting four lithium ion batteries in series. The discharge termination voltage of a one-cell lithium ion battery is about 2.75V. Moreover, the full charge voltage of the lithium ion battery of one cell is about 4V. Then, the discharge termination voltage of the entire storage battery 3 is from 2.75 V × 4 to about 11 V, and the full charge voltage of the entire storage battery 3 is from 4 V × 4 to about 16 V. Then, the output voltage range in which storage battery 3 can be used is about 11V to about 16V.
　充電器４は、電源ラインＰＬの電圧（＋ＢＡＴ）から、蓄電池３を充電するための充電電流を生成する。充電器４は、例えば、昇圧と降圧とが実行可能な昇降圧型のＤＣ／ＤＣコンバータである。 Charger 4 generates a charge current for charging storage battery 3 from the voltage (+ BAT) of power supply line PL. The charger 4 is, for example, a step-up / step-down DC / DC converter capable of performing boosting and bucking.
　そして、蓄電池３の端子電圧が電圧（＋ＢＡＴ）より高い場合、例えば１６Ｖの場合、ＥＣＵ５は、充電器４によって電圧（＋ＢＡＴ）を昇圧させて、予め設定された電流値の充電電流を充電器４から蓄電池３へ供給させる。また、蓄電池３の端子電圧が電圧（＋ＢＡＴ）より低い場合、例えば１１Ｖの場合、ＥＣＵ５は、充電器４によって電圧（＋ＢＡＴ）を降圧させて、予め設定された設定電流値Ｉｃの充電電流を充電器４から蓄電池３へ供給させる。これにより、充電器４は、蓄電池３を定電流充電するようになっている。 When the terminal voltage of the storage battery 3 is higher than the voltage (+ BAT), for example, in the case of 16 V, the ECU 5 boosts the voltage (+ BAT) by the charger 4 to set the charging current of the preset current value to the charger 4 To the storage battery 3. When the terminal voltage of the storage battery 3 is lower than the voltage (+ BAT), for example, in the case of 11 V, the ECU 5 steps down the voltage (+ BAT) by the charger 4 to charge the charging current of the preset current value Ic. Supply the battery 4 to the storage battery 3. Thereby, the charger 4 is configured to charge the storage battery 3 at a constant current.
　充電器４は、例えば、ＦＥＴ（Field Effect Transistor）４１、ダイオード４２、絶縁型のトランス４３、及びダイオード４４を備えて構成されている。電源ラインＰＬは、トランス４３の一次コイルの一端に接続されている。また、トランス４３の一次コイルの他端は、ＦＥＴ４１を介して回路グラウンドに接続されている。ＦＥＴ４１の両端間には、ダイオード（寄生ダイオード）４２が接続されている。トランス４３の二次コイルの一端は回路グラウンドに接続されている。トランス４３の二次コイルの他端はダイオード４４のアノードに接続されている。ダイオード４４のアノードは、電流検出部７を介して蓄電池３の正極に接続されている。 The charger 4 includes, for example, a field effect transistor (FET) 41, a diode 42, an insulating transformer 43, and a diode 44. The power supply line PL is connected to one end of the primary coil of the transformer 43. The other end of the primary coil of the transformer 43 is connected to the circuit ground via the FET 41. A diode (parasitic diode) 42 is connected between both ends of the FET 41. One end of the secondary coil of the transformer 43 is connected to the circuit ground. The other end of the secondary coil of the transformer 43 is connected to the anode of the diode 44. The anode of the diode 44 is connected to the positive electrode of the storage battery 3 via the current detection unit 7.
　電流検出部７は、例えばシャント抵抗やホール素子等の電流センサによって構成されている。電流検出部７は、蓄電池３の充放電電流値を検出し、検出された電流値を示す信号をＥＣＵ５へ出力する。電流検出部７は、例えば、蓄電池３を充電する方向に流れる充電電流をプラスの電流値で示し、蓄電池３を放電する方向に流れる放電電流をマイナスの電流値で示す。 The current detection unit 7 is configured of, for example, a current sensor such as a shunt resistor or a Hall element. The current detection unit 7 detects the charge / discharge current value of the storage battery 3 and outputs a signal indicating the detected current value to the ECU 5. For example, the current detection unit 7 indicates the charging current flowing in the direction of charging the storage battery 3 by a positive current value, and indicates the discharging current flowing in the direction of discharging the storage battery 3 by a negative current value.
　ダイオードＤ１～Ｄ６は、蓄電池３から電源ラインＰＬへ向かう方向が順方向になるように、直列接続されている。そして、ダイオードＤ１のカソードが電源ラインＰＬに接続され、ダイオードＤ６のアノードが電流検出部７を介して蓄電池３の正極に接続されている。ダイオードＤ１～Ｄ６は、１個のオン電圧が例えば０．７Ｖである。 The diodes D1 to D6 are connected in series so that the direction from the storage battery 3 toward the power supply line PL is forward. The cathode of the diode D1 is connected to the power supply line PL, and the anode of the diode D6 is connected to the positive electrode of the storage battery 3 via the current detection unit 7. One on-state voltage of the diodes D1 to D6 is, for example, 0.7V.
　これにより、ダイオードＤ１～Ｄ６のオン電圧の合計が、４．２Ｖとされている。ここで、設定電圧Ｖｓは１２Ｖ、蓄電池３の満充電電圧は約１６Ｖであるから、ダイオードＤ１～Ｄ６のオン電圧の合計は、設定電圧Ｖｓと蓄電池３の満充電電圧との差を超える電圧となる。 Thus, the total of the on voltages of the diodes D1 to D6 is 4.2V. Here, since the set voltage Vs is 12 V and the full charge voltage of the storage battery 3 is about 16 V, the sum of the on voltages of the diodes D1 to D6 exceeds the difference between the set voltage Vs and the full charge voltage of the storage battery 3 Become.
　従って、電源部２が正常に動作して、電圧（＋ＢＡＴ）が設定電圧Ｖｓと等しいときは、蓄電池３が満充電状態であってもダイオードＤ１～Ｄ６はオンしない。従って、電源部２が正常に動作しており、蓄電池３を放電させる必要の無いときは、ダイオードＤ１～Ｄ６がオンせず、蓄電池３が放電しないようにされている。なお、ダイオードＤ１～Ｄ６のオン電圧の合計が設定電圧Ｖｓと蓄電池３の満充電電圧との差と等しい場合、電圧（＋ＢＡＴ）が設定電圧Ｖｓと等しく蓄電池３が満充電であって、ダイオードＤ１～Ｄ６がオンしたとしても、ダイオードＤ１～Ｄ６で生じる電圧降下のために電流は流れないから、ダイオードＤ１～Ｄ６のオン電圧の合計は、設定電圧Ｖｓと蓄電池３の満充電電圧との差以上であればよい。 Therefore, when the power supply unit 2 operates normally and the voltage (+ BAT) is equal to the set voltage Vs, the diodes D1 to D6 do not turn on even if the storage battery 3 is fully charged. Therefore, when the power supply unit 2 is operating normally and it is not necessary to discharge the storage battery 3, the diodes D1 to D6 are not turned on and the storage battery 3 is prevented from discharging. When the total of the on-state voltages of diodes D1 to D6 is equal to the difference between set voltage Vs and the full charge voltage of storage battery 3, voltage (+ BAT) is equal to set voltage Vs and storage battery 3 is fully charged. Even if D1 to D6 are turned on, no current flows because of the voltage drop occurring in diodes D1 to D6, so the total on voltage of diodes D1 to D6 is equal to or greater than the difference between set voltage Vs and the full charge voltage of storage battery 3 If it is
　また、目標電圧範囲の下限値は８Ｖである。従って、ダイオードＤ１～Ｄ６のオン電圧の合計は、目標電圧範囲の下限値と蓄電池３の満充電電圧との差である８Ｖに満たない電圧となっている。すなわち、電源ラインＰＬの電圧（＋ＢＡＴ）と、蓄電池３の出力電圧との電位差が４．２Ｖ以上になると、ダイオードＤ１～Ｄ６がオンする。 Further, the lower limit value of the target voltage range is 8V. Therefore, the total of the on-state voltages of the diodes D1 to D6 is a voltage less than 8 V which is the difference between the lower limit value of the target voltage range and the full charge voltage of the storage battery 3. That is, when the potential difference between the voltage (+ BAT) of the power supply line PL and the output voltage of the storage battery 3 becomes 4.2 V or more, the diodes D1 to D6 turn on.
　蓄電池３は、通常、充電器４及び制御部５２によって満充電状態にされているから、例えばＤＣ／ＤＣコンバータ２１が故障するなどして電源部２から電源ラインＰＬへの電源電圧供給ができなくなった場合、電圧（＋ＢＡＴ）が目標電圧範囲の下限値を下回る前に、すなわち補機が動作しなくなる前に、ダイオードＤ１～Ｄ６がオンして蓄電池３の出力電圧が電源ラインＰＬへ印加される。 Since storage battery 3 is normally fully charged by charger 4 and control unit 52, for example, DC / DC converter 21 breaks down and power supply unit 2 can not supply power supply voltage to power supply line PL. If the voltage (+ BAT) falls below the lower limit value of the target voltage range, that is, before the auxiliaries stop operating, diodes D1 to D6 are turned on and the output voltage of storage battery 3 is applied to power supply line PL. .
　これにより、電源部２から電源ラインＰＬへの電源電圧供給ができなくなった場合、例えばＥＣＵ５のような制御回路を用いて異常を検出し、充電器によって電流を逆流させる制御を行う従来方式よりも、電源部２からの電源ラインＰＬへの供給電圧が低下した場合に蓄電池３から電源ラインＰＬへ電圧供給が開始されるまでの時間を短縮することが可能となる。 Thereby, when the power supply voltage can not be supplied from the power supply unit 2 to the power supply line PL, for example, a control circuit such as the ECU 5 is used to detect an abnormality, and a charger performs control to reverse current. When the supply voltage from the power supply unit 2 to the power supply line PL decreases, it is possible to shorten the time until the voltage supply from the storage battery 3 to the power supply line PL is started.
　また、ダイオードＤ１とダイオードＤ２との接続点Ｐ１が、スイッチング素子ＳＷ１と電流検出部７とを介して蓄電池３の正極に接続されている。スイッチング素子ＳＷ１としては、例えばＦＥＴ等のトランジスタやリレースイッチ等のスイッチング素子が用いられる。スイッチング素子ＳＷ１は、ＥＣＵ５からの制御信号に応じてオン（閉）、オフ（開）する。 In addition, a connection point P1 between the diode D1 and the diode D2 is connected to the positive electrode of the storage battery 3 via the switching element SW1 and the current detection unit 7. As the switching element SW1, for example, a transistor such as a FET or a switching element such as a relay switch is used. The switching element SW1 is turned on (closed) and turned off (opened) in accordance with a control signal from the ECU 5.
　なお、スイッチング素子ＳＷ１は、ダイオードＤ１～Ｄ６のうち一つを除いた残余のダイオードを短絡するように設けられていればよく、例えばダイオードＤ１のカソードとダイオードＤ５のアノードとの間に設けられていてもよい。 The switching element SW1 may be provided so as to short the remaining diodes except one of the diodes D1 to D6. For example, the switching element SW1 is provided between the cathode of the diode D1 and the anode of the diode D5. May be
　電圧検出部８は、例えばアナログデジタルコンバータ等を用いて構成されている。電圧検出部８は、電圧（＋ＢＡＴ）を検出し、電圧（＋ＢＡＴ）を示す信号をＥＣＵ５へ出力する。 The voltage detection unit 8 is configured using, for example, an analog-to-digital converter or the like. The voltage detection unit 8 detects a voltage (+ BAT) and outputs a signal indicating the voltage (+ BAT) to the ECU 5.
　ＥＣＵ５は、例えばＣＰＵ（Central Processing Unit）、ＲＯＭ（Read
Only Memory）、ＲＡＭ（Random Access Memory）、タイマ回路、及びこれらの周辺回路等を用いて構成されている。そして、ＥＣＵ５は、例えばＲＯＭに記憶された制御プログラムを実行することによって、判定部５１、及び制御部５２として機能する。 The ECU 5 is, for example, a CPU (Central Processing Unit), a ROM (Read)
Only memory, RAM (Random Access Memory), timer circuit, and peripheral circuits thereof are used. Then, the ECU 5 functions as the determination unit 51 and the control unit 52 by executing, for example, a control program stored in the ROM.
　ＥＣＵ５は、電源端子５３，５４を備えている。電源端子５３は、電源ラインＰＬに接続されている。従って、電源端子５３には、電圧（＋ＢＡＴ）が供給される。 The ECU 5 is provided with power supply terminals 53 and 54. The power supply terminal 53 is connected to the power supply line PL. Therefore, the voltage (+ BAT) is supplied to the power supply terminal 53.
　電源端子５４は操作スイッチＳＷ０の一端に接続され、操作スイッチＳＷ０の他端は電流検出部７を介して蓄電池３の正極に接続されている。従って、操作スイッチＳＷ０がオンされると、蓄電池３から電流検出部７及び操作スイッチＳＷ０を介して電源端子５４へ出力電圧Ｖｏｕｔが供給されるようになっている。 The power supply terminal 54 is connected to one end of the operation switch SW0, and the other end of the operation switch SW0 is connected to the positive electrode of the storage battery 3 via the current detection unit 7. Therefore, when the operation switch SW0 is turned on, the output voltage Vout is supplied from the storage battery 3 to the power supply terminal 54 through the current detection unit 7 and the operation switch SW0.
　操作スイッチＳＷ０は、例えばユーザが操作可能な押しボタンスイッチである。 The operation switch SW0 is, for example, a push button switch that can be operated by the user.
　そして、ＥＣＵ５、すなわち判定部５１及び制御部５２は、電源端子５３，５４のいずれかによって受電された電源電圧によって動作する。 Then, the ECU 5, that is, the determination unit 51 and the control unit 52 operate with the power supply voltage received by one of the power supply terminals 53 and 54.
　制御部５２は、電流検出部７によって検出される電流値を監視する。そして、制御部５２は、電流検出部７によって検出される電流値が、設定電流値Ｉｃとなるように、ＦＥＴ４１のオン、オフを制御する。これにより、制御部５２は、充電器４によって、蓄電池３の定電流充電を実行させる。また、制御部５２は、例えば図略の電圧検出回路によって、蓄電池３の端子電圧が満充電電圧になったことが検出されたとき、充電器４による定電流充電を停止させる。 The control unit 52 monitors the current value detected by the current detection unit 7. Then, the control unit 52 controls the on / off of the FET 41 so that the current value detected by the current detection unit 7 becomes the set current value Ic. Thereby, the control unit 52 causes the charger 4 to perform constant current charging of the storage battery 3. Further, when it is detected that the terminal voltage of the storage battery 3 has become a full charge voltage, for example, by the voltage detection circuit (not shown), the control unit 52 stops the constant current charging by the charger 4.
　判定部５１は、電流検出部７によって検出された電流値がマイナスの値となったとき、すなわち蓄電池３が放電状態となったときに、電源部２による電源ラインＰＬへの電源供給が不足していると判定する。 When determination unit 51 determines that the current value detected by current detection unit 7 is a negative value, that is, storage battery 3 is in a discharged state, power supply to power supply line PL by power supply unit 2 is insufficient. It is determined that
　なお、判定部５１は、電圧検出部８によって検出される電圧（＋ＢＡＴ）を監視し、電圧（＋ＢＡＴ）が予め設定された閾値電圧Ｖｔｈを下回った場合、電源部２による電源ラインＰＬへの電源供給が不足していると判定するようにしてもよい。この場合、閾値電圧Ｖｔｈは、設定電圧Ｖｓより低い電圧、例えば目標電圧範囲の下限値である８Ｖとされる。 The determination unit 51 monitors the voltage (+ BAT) detected by the voltage detection unit 8, and when the voltage (+ BAT) falls below a preset threshold voltage Vth, the power supply to the power supply line PL by the power supply unit 2 is performed. It may be determined that the supply is insufficient. In this case, the threshold voltage Vth is a voltage lower than the set voltage Vs, for example, 8 V which is the lower limit value of the target voltage range.
　また、判定部５１は、電流検出部７によって検出された電流値がマイナスの値になる条件、あるいは電圧（＋ＢＡＴ）が閾値電圧Ｖｔｈを下回る条件のうち、少なくとも一つの条件が満たされた場合に、電源部２による電源ラインＰＬへの電源供給が不足していると判定するようにしてもよい。この場合、電源部２の故障等による電源ラインＰＬへの電源供給不足の判定精度が向上する。 In addition, when at least one of the condition that the current value detected by the current detection unit 7 is a negative value or the condition that the voltage (+ BAT) is lower than the threshold voltage Vth is satisfied, the determination unit 51 is satisfied. It may be determined that the power supply to the power supply line PL by the power supply unit 2 is insufficient. In this case, the determination accuracy of the power supply shortage to the power supply line PL due to the failure or the like of the power supply unit 2 is improved.
　制御部５２は、判定部５１によって電源部２による電源供給が不足していると判定された場合、スイッチング素子ＳＷ１をオンさせる。ダイオードＤ１～Ｄ６がオンして蓄電池３の出力電圧が電源ラインＰＬへ印加されたとき、ダイオードＤ１～Ｄ６では、オン電圧の合計にほぼ等しい順方向電圧の電圧降下、すなわち約４．２Ｖの電圧降下が生じる。そのため、ダイオードＤ１～Ｄ６での電圧降下と流れる電流の積に相当する電力損失が生じる。 If the determination unit 51 determines that the power supply by the power supply unit 2 is insufficient, the control unit 52 turns on the switching element SW1. When diodes D1 to D6 are turned on and the output voltage of storage battery 3 is applied to power supply line PL, forward voltage drop in diode D1 to D6 is approximately equal to the total on voltage, ie, a voltage of about 4.2 V There is a descent. As a result, a power loss corresponding to the product of the voltage drop across the diodes D1 to D6 and the current flow occurs.
　そこで、制御部５２は、スイッチング素子ＳＷ１をオンさせることによって、蓄電池３の出力電流を、ダイオードＤ２～Ｄ６をバイパスさせる。これにより、電力損失はダイオードＤ１において生じる約０．７Ｖの電圧降下と電流との積となるから、ダイオードＤ１～Ｄ６によって生じる電力損失を低減することができる。 Therefore, the control unit 52 causes the diodes D2 to D6 to bypass the output current of the storage battery 3 by turning on the switching element SW1. Thereby, since the power loss is a product of the voltage drop of about 0.7 V and the current generated in the diode D1, the power loss generated by the diodes D1 to D6 can be reduced.
　なお、ダイオードＤ１～Ｄ６で生じる順方向電圧は、ダイオードに流れる電流が増加すると増大するから、必ずしも各ダイオードのオン電圧の合計と一致しない。しかしながら、以下の説明においては、近似的にダイオードＤ１～Ｄ６で生じる順方向電圧と各ダイオードのオン電圧の合計とはほぼ等しいものとして説明する。 The forward voltage generated in the diodes D1 to D6 increases as the current flowing through the diodes increases, and thus does not necessarily coincide with the sum of the on voltages of the respective diodes. However, in the following description, it is assumed that the sum of the forward voltage generated at the diodes D1 to D6 and the on voltage of each diode is approximately equal.
　ここで、例えば蓄電池３の出力電圧Ｖｏｕｔが１１ＶのときにＤＣ／ＤＣコンバータ２１の故障が生じた場合、電圧（＋ＢＡＴ）が６．８Ｖまで低下したときにダイオードＤ１～Ｄ６がオンする。しかしながら、ダイオードＤ１～Ｄ６での電圧降下が４．２Ｖあるので、電圧（＋ＢＡＴ）は１１Ｖ－４．２＝６．８Ｖのままとなる。 Here, for example, when the failure of the DC / DC converter 21 occurs when the output voltage Vout of the storage battery 3 is 11 V, the diodes D1 to D6 turn on when the voltage (+ BAT) decreases to 6.8 V. However, since there is a voltage drop of 4.2V at the diodes D1 to D6, the voltage (+ BAT) remains at 11V-4.2 = 6.8V.
　しかしながら、補機が動作可能な電源電圧範囲は８Ｖ～１６Ｖであるから、電圧（＋ＢＡＴ）が６．８Ｖの状態では、ＥＣＵ５等の補機を動作させることができない。このような場合、ユーザが操作スイッチＳＷ０をオンすると、蓄電池３の出力電圧Ｖｏｕｔ（＝１１Ｖ）がそのまま電源端子５４へ供給される。 However, since the power supply voltage range in which the auxiliary device can operate is 8V to 16V, the auxiliary device such as the ECU 5 can not operate when the voltage (+ BAT) is 6.8V. In such a case, when the user turns on the operation switch SW0, the output voltage Vout (= 11 V) of the storage battery 3 is supplied to the power supply terminal 54 as it is.
　そうすると、ＥＣＵ５が動作を開始する。このとき、蓄電池３は放電しているから、判定部５１によって電源部２による電源供給が不足していると判定され、制御部５２によってスイッチング素子ＳＷ１がオンされる。そうすると、ダイオードＤ２～Ｄ６がバイパスされて電圧降下が減少し、電圧（＋ＢＡＴ）は、１１Ｖ―０．７Ｖ＝１０．３Ｖとなる。これにより、補機を動作させることが可能となる。 Then, the ECU 5 starts operation. At this time, since the storage battery 3 is discharged, the determination unit 51 determines that the power supply by the power supply unit 2 is insufficient, and the control unit 52 turns on the switching element SW1. Then, the diodes D2 to D6 are bypassed to reduce the voltage drop, and the voltage (+ BAT) becomes 11V−0.7V = 10.3V. This makes it possible to operate the accessory.
　図２は、図１に示す車両用電源システム１の動作の一例を示すタイミングチャートである。縦軸は電圧、横軸は時間の経過を示している。また、実線は電圧（＋ＢＡＴ）を示し、一点鎖線は蓄電池３の出力電圧Ｖｏｕｔを示している。 FIG. 2 is a timing chart showing an example of the operation of the vehicular power supply system 1 shown in FIG. The vertical axis shows voltage, and the horizontal axis shows the passage of time. The solid line indicates the voltage (+ BAT), and the alternate long and short dash line indicates the output voltage Vout of the storage battery 3.
　まず、タイミングＴ０では、蓄電池３は満充電状態にされており、出力電圧Ｖｏｕｔは１６Ｖとなっている。また、タイミングＴ０では、電源部２が正常に動作しており、電源部２からの出力電圧によって、電圧（＋ＢＡＴ）は１２Ｖになっている。タイミングＴ０においては、出力電圧Ｖｏｕｔと電圧（＋ＢＡＴ）との差は４Ｖであり、ダイオードＤ１～Ｄ６のオン電圧の合計である４．２Ｖに満たない。そのため、ダイオードＤ１～Ｄ６はオフしており、蓄電池３は放電しない。 First, at timing T0, the storage battery 3 is fully charged, and the output voltage Vout is 16V. At timing T0, the power supply unit 2 operates normally, and the voltage (+ BAT) is 12 V by the output voltage from the power supply unit 2. At timing T0, the difference between the output voltage Vout and the voltage (+ BAT) is 4 V, which is less than 4.2 V which is the total of the on-voltages of the diodes D1 to D6. Therefore, the diodes D1 to D6 are off, and the storage battery 3 is not discharged.
　そして、タイミングＴ１において、例えばＤＣ／ＤＣコンバータ２１が故障するなどして電源部２からの電圧出力がなくなると、電圧（＋ＢＡＴ）が急激に低下する。そうすると、出力電圧Ｖｏｕｔと電圧（＋ＢＡＴ）との差が４．２Ｖを超え、ダイオードＤ１～Ｄ６がオンする（タイミングＴ２）。 Then, at timing T1, when the voltage output from the power supply unit 2 disappears, for example, because the DC / DC converter 21 breaks down, the voltage (+ BAT) drops sharply. Then, the difference between the output voltage Vout and the voltage (+ BAT) exceeds 4.2 V, and the diodes D1 to D6 are turned on (timing T2).
　ダイオードＤ１～Ｄ６がオンすると、蓄電池３の出力電圧Ｖｏｕｔが電流検出部７及びダイオードＤ１～Ｄ６を介して電源ラインＰＬへ供給される。このとき、ダイオードＤ１～Ｄ６の順方向電圧によって、４．２Ｖの電圧降下が生じるため、電圧（＋ＢＡＴ）は、１６－４．２＝１１．８Ｖとなる。 When the diodes D1 to D6 are turned on, the output voltage Vout of the storage battery 3 is supplied to the power supply line PL through the current detection unit 7 and the diodes D1 to D6. At this time, a voltage drop of 4.2 V is generated by the forward voltage of the diodes D1 to D6, so that the voltage (+ BAT) is 16-4.2 = 11.8 V.
　そうすると、電源部２からの電圧出力がなくなってからダイオードＤ１～Ｄ６がオンするまでの時間は、ダイオードのスイッチング応答時間のみであるから、電源部２からの電圧出力がなくなった後、極めて短時間で蓄電池３からの電力供給を開始することが可能となる。 Then, since the time from when the voltage output from the power supply unit 2 disappears to when the diodes D1 to D6 turn on is only the switching response time of the diode, it is extremely short after the voltage output from the power supply unit 2 disappears. Power supply from the storage battery 3 can be started.
　そして、タイミングＴ２において蓄電池３からの電力供給が開始されると、電流検出部７によって検出される電流値はマイナスの値となり、蓄電池３が放電していることを示すこととなる。そうすると、判定部５１によって電源部２による電源供給が不足していると判定され、制御部５２によって、スイッチング素子ＳＷ１がオンされる（タイミングＴ３）。 Then, when power supply from the storage battery 3 is started at timing T2, the current value detected by the current detection unit 7 becomes a negative value, which indicates that the storage battery 3 is discharged. Then, the determination unit 51 determines that the power supply by the power supply unit 2 is insufficient, and the control unit 52 turns on the switching element SW1 (timing T3).
　タイミングＴ３において、スイッチング素子ＳＷ１がオンされると、蓄電池３の出力電流はダイオードＤ２～Ｄ６をバイパスする結果、電圧（＋ＢＡＴ）は、ダイオードＤ１での電圧降下である０．７Ｖだけ出力電圧Ｖｏｕｔ（１６Ｖ）から低下した１５．３Ｖとなる。 At timing T3, when the switching element SW1 is turned on, the output current of the storage battery 3 bypasses the diodes D2 to D6. As a result, the voltage (+ BAT) becomes 0.7V which is a voltage drop at the diode D1. It becomes 15.3V which decreased from 16V).
　これにより、ダイオードＤ２～Ｄ６における電力損失がなくなるので、電力損失を低減することができる。 Thereby, power loss can be reduced because power loss in the diodes D2 to D6 is eliminated.
　なお、設定電圧Ｖｓを１２Ｖとする例を示したが、例えば図３に示すように、ＤＣ／ＤＣコンバータ２１ａから出力される設定電圧Ｖｓを、蓄電池３の放電終止電圧である１１Ｖより低い１０Ｖとしてもよい。図３に示す車両用電源システム１ａは、ＤＣ／ＤＣコンバータ２１ａが、設定電圧Ｖｓとして１０Ｖを電源ラインＰＬへ出力する点で、図１に示す車両用電源システム１と異なる。また、車両用電源システム１ａは、９個のダイオードＤ１～Ｄ９が直列接続されており、ダイオードＤ１～Ｄ９のオン電圧の合計が６．３Ｖにされている点で、図１に示す車両用電源システム１と異なる。 Although an example in which the set voltage Vs is 12 V is shown, for example, as shown in FIG. 3, the set voltage Vs output from the DC / DC converter 21 a is 10 V lower than 11 V which is the discharge termination voltage of the storage battery 3. It is also good. Vehicle power supply system 1a shown in FIG. 3 differs from vehicle power supply system 1 shown in FIG. 1 in that DC / DC converter 21a outputs 10 V to power supply line PL as set voltage Vs. Further, in the power supply system 1a for a vehicle, nine diodes D1 to D9 are connected in series, and the total on voltage of the diodes D1 to D9 is 6.3 V. Different from system 1
　また、車両用電源システム１ａは、昇降圧コンバータである充電器４の代わりに、充電器６を用いる点で車両用電源システム１と異なる。充電器６は、電圧（＋ＢＡＴ）を昇圧することによって、蓄電池３を充電するための充電電流を生成する昇圧型のＤＣ／ＤＣコンバータである。 Vehicle power supply system 1a is different from vehicle power supply system 1 in that charger 6 is used instead of charger 4 which is a buck-boost converter. The charger 6 is a step-up DC / DC converter that generates a charging current for charging the storage battery 3 by boosting a voltage (+ BAT).
　充電器６は、コイル６１、ＦＥＴ６２、及びダイオード６３，６４を備えている。コイル６１は、一端が電源ラインＰＬに接続され、他端がダイオード６４のアノードに接続されている。ダイオード６４のカソードは、電流検出部７を介して蓄電池３の正極に接続されている。また、ダイオード６４のアノードは、ＦＥＴ６２を介して回路グラウンドに接続されている。ＦＥＴ６２の両端間には、ダイオード（寄生ダイオード）６３が接続されている。 The charger 6 includes a coil 61, an FET 62, and diodes 63 and 64. One end of the coil 61 is connected to the power supply line PL, and the other end is connected to the anode of the diode 64. The cathode of the diode 64 is connected to the positive electrode of the storage battery 3 via the current detection unit 7. In addition, the anode of the diode 64 is connected to the circuit ground via the FET 62. A diode (parasitic diode) 63 is connected between both ends of the FET 62.
　車両用電源システム１ａにおいては、電源部２ａが正常に動作している限り、設定電圧Ｖｓすなわち電圧（＋ＢＡＴ）は蓄電池３の放電終止電圧より低い。そのため、充電器６は、電圧（＋ＢＡＴ）を降圧する必要がない。その結果、充電器４よりも簡素な構成で実現でき、従って充電器４よりも低コストである昇圧型のＤＣ／ＤＣコンバータを、充電器６として用いることができる。 In the vehicle power supply system 1a, the set voltage Vs, that is, the voltage (+ BAT) is lower than the discharge termination voltage of the storage battery 3 as long as the power supply unit 2a operates normally. Therefore, the charger 6 does not need to step down the voltage (+ BAT). As a result, a step-up type DC / DC converter that can be realized with a simpler configuration than the charger 4 and therefore cost less than the charger 4 can be used as the charger 6.
　なお、設定電圧Ｖｓが１２Ｖの場合と１０Ｖの場合とを例示した。しかしながら、設定電圧Ｖｓは、補機が動作可能な電源電圧範囲内の電圧、すなわち目標電圧範囲内の電圧であればよく、１２Ｖ及び１０Ｖに限らない。 The cases where the set voltage Vs is 12 V and 10 V are illustrated. However, the set voltage Vs may be a voltage within the power supply voltage range in which the accessory can operate, that is, a voltage within the target voltage range, and is not limited to 12 V and 10 V.
　（第２実施形態）
　次に、本発明の第２実施形態に係る車両用電源システム１ｂについて説明する。図４は、本発明の第２実施形態に係る車両用電源システム１ｂの構成の一例を示す回路図である。図４に示す車両用電源システム１ｂと図１に示す車両用電源システム１とでは、下記の点で異なる。 Second Embodiment
Next, a vehicular power supply system 1b according to a second embodiment of the present invention will be described. FIG. 4 is a circuit diagram showing an example of the configuration of a vehicular power supply system 1b according to a second embodiment of the present invention. The vehicle power supply system 1b shown in FIG. 4 differs from the vehicle power supply system 1 shown in FIG. 1 in the following points.
　すなわち、車両用電源システム１ｂは、スイッチング素子ＳＷ１に加えて、スイッチング素子ＳＷ２～ＳＷ５を備えている。そして、ダイオードＤ２とダイオードＤ３との接続点Ｐ２がスイッチング素子ＳＷ２と電流検出部７とを介して蓄電池３の正極に接続され、ダイオードＤ３とダイオードＤ４との接続点Ｐ３がスイッチング素子ＳＷ３と電流検出部７とを介して蓄電池３の正極に接続され、ダイオードＤ４とダイオードＤ５との接続点Ｐ４がスイッチング素子ＳＷ４と電流検出部７とを介して蓄電池３の正極に接続され、ダイオードＤ５とダイオードＤ６との接続点Ｐ５がスイッチング素子ＳＷ５と電流検出部７とを介して蓄電池３の正極に接続されている。 That is, the vehicle power supply system 1b includes switching elements SW2 to SW5 in addition to the switching element SW1. The connection point P2 between the diode D2 and the diode D3 is connected to the positive electrode of the storage battery 3 via the switching element SW2 and the current detection unit 7, and the connection point P3 between the diode D3 and the diode D4 is current detection from the switching element SW3 The junction point P4 of the diode D4 and the diode D5 is connected to the positive pole of the storage battery 3 via the switching element SW4 and the current detection unit 7, and the diode D5 and the diode D6 are connected. The connection point P5 between the two is connected to the positive electrode of the storage battery 3 via the switching element SW5 and the current detection unit 7.
　スイッチング素子ＳＷ１～ＳＷ５としては、例えばＦＥＴ等のトランジスタやリレースイッチ等のスイッチング素子が用いられる。スイッチング素子ＳＷ１～ＳＷ５は、ＥＣＵ５からの制御信号に応じてそれぞれオン（閉）、オフ（開）する。スイッチング素子ＳＷ１～ＳＷ５は、短絡部の一例に相当している。 As the switching elements SW1 to SW5, for example, transistors such as FETs and switching elements such as relay switches are used. The switching elements SW1 to SW5 are turned on (closed) and off (opened) in accordance with the control signal from the ECU 5, respectively. The switching elements SW1 to SW5 correspond to an example of a short circuit part.
　ＥＣＵ５ｂは、判定部５１を備えない。また、ＥＣＵ５ｂは、制御部５２の代わりに制御部５２ｂを備える。 The ECU 5 b does not include the determination unit 51. Further, the ECU 5 b includes a control unit 52 b instead of the control unit 52.
　制御部５２ｂは、電圧検出部８によって検出された電圧（＋ＢＡＴ）が閾値電圧Ｖｔｈを下回った場合、最も蓄電池３に近い位置に位置する接続点Ｐ５に対応するスイッチング素子ＳＷ５から順に、電圧（＋ＢＡＴ）が設定電圧Ｖｓ以上になるまで、スイッチング素子ＳＷ５～ＳＷ１を、順次オンさせる。 When the voltage (+ BAT) detected by voltage detection unit 8 falls below threshold voltage Vth, control unit 52b sequentially selects voltage (+ BAT) from switching element SW5 corresponding to connection point P5 positioned closest to storage battery 3. The switching elements SW5 to SW1 are sequentially turned on until the voltage V.sub.s becomes equal to or higher than the set voltage V.sub.s.
　なお、制御部５２ｂは、電圧（＋ＢＡＴ）が閾値電圧Ｖｔｈを下回った場合、スイッチング素子ＳＷ５～ＳＷ１を一つずつオンさせることによって、短絡されるダイオードの数、すなわち電流がバイパスされるダイオードの数を順次増加させればよい。従って、制御部５２ｂがスイッチング素子ＳＷ５～ＳＷ１をオンさせる順序は、特定の順序に限定されない。 When the voltage (+ BAT) falls below the threshold voltage Vth, the control unit 52b turns on the switching elements SW5 to SW1 one by one to thereby reduce the number of diodes shorted, that is, the number of diodes whose current is bypassed. Should be increased sequentially. Therefore, the order in which the control unit 52b turns on the switching elements SW5 to SW1 is not limited to a specific order.
　また、制御部５２ｂは、スイッチング素子ＳＷ５～ＳＷ１を順次オンさせる際に、一つのスイッチング素子をオンさせてから次のスイッチング素子をオンさせるまでの時間を、予め設定された設定時間ｔｓ以上とする。 In addition, when sequentially turning on the switching elements SW5 to SW1, the control unit 52b sets a time from turning on one switching element to turning on the next switching element to be equal to or longer than a preset setting time ts. .
　設定時間ｔｓが長くなるほど、スイッチング素子ＳＷ５～ＳＷ１を順次オンさせることによる電圧（＋ＢＡＴ）の上昇速度が遅くなる。一方、電圧（＋ＢＡＴ）が急激に上昇すると、補機が誤動作する場合がある。そこで、補機が誤動作することなく安定動作できるような設定時間ｔｓの値が、例えば実験的に求められて、予め設定時間ｔｓとして設定されている。 As the set time ts becomes longer, the rising speed of the voltage (+ BAT) by sequentially turning on the switching elements SW5 to SW1 becomes slower. On the other hand, if the voltage (+ BAT) rises rapidly, the accessory may malfunction. Therefore, a value of the set time ts that allows stable operation of the auxiliary machine without malfunctioning is obtained, for example, experimentally, and set in advance as the set time ts.
　その他の構成は図１に示す車両用電源システム１と同様であるのでその説明を省略し、以下本実施形態の特徴的な点について説明する。 The other configuration is the same as that of the power supply system 1 for a vehicle shown in FIG.
　図５は、図４に示す車両用電源システム１ｂの動作の一例を示すタイミングチャートである。縦軸は電圧、横軸は時間の経過を示している。また、実線は電圧（＋ＢＡＴ）を示し、一点鎖線は蓄電池３の出力電圧Ｖｏｕｔを示している。 FIG. 5 is a timing chart showing an example of the operation of the vehicular power supply system 1b shown in FIG. The vertical axis shows voltage, and the horizontal axis shows the passage of time. The solid line indicates the voltage (+ BAT), and the alternate long and short dash line indicates the output voltage Vout of the storage battery 3.
　まず、タイミングＴ０では、蓄電池３の出力電圧Ｖｏｕｔは１５Ｖとなっている。また、タイミングＴ０では、電源部２が正常に動作しており、電源部２からの出力電圧によって、電圧（＋ＢＡＴ）は１２Ｖになっている。タイミングＴ０においては、出力電圧Ｖｏｕｔと電圧（＋ＢＡＴ）との差は３Ｖであり、ダイオードＤ１～Ｄ６のオン電圧の合計である４．２Ｖに満たない。そのため、ダイオードＤ１～Ｄ６はオフしている。 First, at timing T0, the output voltage Vout of the storage battery 3 is 15V. At timing T0, the power supply unit 2 operates normally, and the voltage (+ BAT) is 12 V by the output voltage from the power supply unit 2. At timing T0, the difference between the output voltage Vout and the voltage (+ BAT) is 3 V, which is less than 4.2 V which is the total of the on-voltages of the diodes D1 to D6. Therefore, the diodes D1 to D6 are off.
　そして、タイミングＴ１において、例えばＤＣ／ＤＣコンバータ２１が故障するなどして電源部２からの電圧出力がなくなると、電圧（＋ＢＡＴ）が急激に低下する。そうすると、出力電圧Ｖｏｕｔと電圧（＋ＢＡＴ）との差が４．２Ｖを超え、ダイオードＤ１～Ｄ６がオンする（タイミングＴ２）。 Then, at timing T1, when the voltage output from the power supply unit 2 disappears, for example, because the DC / DC converter 21 breaks down, the voltage (+ BAT) drops sharply. Then, the difference between the output voltage Vout and the voltage (+ BAT) exceeds 4.2 V, and the diodes D1 to D6 are turned on (timing T2).
　ダイオードＤ１～Ｄ６がオンすると、蓄電池３の出力電圧Ｖｏｕｔが電流検出部７及びダイオードＤ１～Ｄ６を介して電源ラインＰＬへ供給される。このとき、ダイオードＤ１～Ｄ６の順方向電圧によって、４．２Ｖの電圧降下が生じるため、電圧（＋ＢＡＴ）は、１５－４．２＝１０．８Ｖとなる。 When the diodes D1 to D6 are turned on, the output voltage Vout of the storage battery 3 is supplied to the power supply line PL through the current detection unit 7 and the diodes D1 to D6. At this time, a voltage drop of 4.2 V is generated by the forward voltage of the diodes D1 to D6, so that the voltage (+ BAT) is 15-4.2 = 10.8 V.
　そうすると、電源部２からの電圧出力がなくなってからダイオードＤ１～Ｄ６がオンするまでの時間は、ダイオードのスイッチング応答時間のみであるから、電源部２からの電圧出力がなくなった後、極めて短時間で蓄電池３からの電力供給を開始することが可能となる。 Then, since the time from when the voltage output from the power supply unit 2 disappears to when the diodes D1 to D6 turn on is only the switching response time of the diode, it is extremely short after the voltage output from the power supply unit 2 disappears. Power supply from the storage battery 3 can be started.
　また、タイミングＴ１において、電圧検出部８によって検出される電圧（＋ＢＡＴ）は閾値電圧Ｖｔｈを下回る。そのため、制御部５２ｂは、スイッチング素子ＳＷ５をオンさせる（タイミングＴ３）。そうすると、蓄電池３の出力電流はダイオードＤ６をバイパスする結果、電圧（＋ＢＡＴ）は、ダイオードＤ１～Ｄ５での電圧降下である３．５Ｖだけ出力電圧Ｖｏｕｔ（＝１５Ｖ）から低下した１１．５Ｖとなる。 Also, at timing T1, the voltage (+ BAT) detected by the voltage detection unit 8 falls below the threshold voltage Vth. Therefore, the control unit 52b turns on the switching element SW5 (timing T3). Then, as a result of the output current of storage battery 3 bypassing diode D6, voltage (+ BAT) becomes 11.5 V which is reduced from output voltage Vout (= 15 V) by 3.5 V which is a voltage drop at diodes D1 to D5. .
　次に、１１．５Ｖは設定電圧Ｖｓ（＝１２Ｖ）に満たないから、制御部５２ｂは、タイミングＴ３から設定時間ｔｓが経過したタイミングＴ４において、スイッチング素子ＳＷ４をオンさせる（タイミングＴ４）。そうすると、蓄電池３の出力電流はダイオードＤ６，Ｄ５をバイパスする結果、電圧（＋ＢＡＴ）は、ダイオードＤ１～Ｄ４での電圧降下である２．８Ｖだけ出力電圧Ｖｏｕｔ（＝１５Ｖ）から低下した１２．２Ｖとなる。 Next, since 11.5 V does not reach the set voltage Vs (= 12 V), the control unit 52b turns on the switching element SW4 at timing T4 when the set time ts has elapsed from timing T3 (timing T4). Then, as a result of the output current of storage battery 3 bypassing diodes D6 and D5, the voltage (+ BAT) is lowered from output voltage Vout (= 15 V) by 2.8 V which is a voltage drop at diodes D1 to D4. It becomes.
　そうすると、１２．２Ｖは設定電圧Ｖｓ（＝１２Ｖ）以上であるから、制御部５２ｂは、以降のスイッチング素子ＳＷ３，ＳＷ２，ＳＷ１をオンさせることなく、スイッチング素子ＳＷ４をオンさせた状態を維持する。そうすると、電圧（＋ＢＡＴ）が１２．２Ｖに維持される。 Then, since 12.2 V is equal to or higher than the set voltage Vs (= 12 V), the control unit 52b maintains the state in which the switching element SW4 is turned on without turning on the subsequent switching elements SW3, SW2, and SW1. Then, the voltage (+ BAT) is maintained at 12.2V.
　これにより、車両用電源システム１ｂは、車両用電源システム１と比べて、電圧（＋ＢＡＴ）を設定電圧Ｖｓ（＝１２Ｖ）により近い電圧に維持することができる。補機は、例えば８Ｖ～１６Ｖといった電源電圧範囲で動作可能であるものの、一般的には、電源部２から正常に設定電圧Ｖｓの電圧（＋ＢＡＴ）が出力されている場合に補機の動作が最も安定する。 Thus, the vehicle power supply system 1b can maintain the voltage (+ BAT) at a voltage closer to the set voltage Vs (= 12 V) as compared to the vehicle power supply system 1. Although the accessory can operate in the power supply voltage range of 8 V to 16 V, for example, the operation of the accessory is generally performed when the voltage (+ BAT) of the set voltage Vs is normally output from the power supply unit 2 Most stable.
　そこで、車両用電源システム１ｂは、車両用電源システム１と比べて、電圧（＋ＢＡＴ）を設定電圧Ｖｓ（＝１２Ｖ）により近い電圧に維持することによって、補機の動作の安定性を向上させることができる。 Therefore, the vehicle power supply system 1b improves the stability of the operation of the accessory by maintaining the voltage (+ BAT) at a voltage closer to the set voltage Vs (= 12 V) as compared to the vehicle power supply system 1. Can.
　なお、設定電圧Ｖｓを１２Ｖとする例を示したが、図３に示す車両用電源システム１ａと同様、例えば図６に示すように、設定電圧Ｖｓを、蓄電池３の放電終止電圧である１１Ｖより低い１０Ｖとしてもよい。図６に示す車両用電源システム１ｃは、ＤＣ／ＤＣコンバータ２１ａが、設定電圧Ｖｓとして１０Ｖを電源ラインＰＬへ出力する点で、図４に示す車両用電源システム１ｂと異なる。また、車両用電源システム１ｃは、９個のダイオードＤ１～Ｄ９が直列接続されており、ダイオードＤ１～Ｄ９のオン電圧の合計が６．３Ｖにされている点で、図４に示す車両用電源システム１ｂと異なる。 Although an example in which the set voltage Vs is 12 V is shown, as in the case of the vehicle power supply system 1a shown in FIG. 3, for example, as shown in FIG. It may be as low as 10V. Vehicle power supply system 1c shown in FIG. 6 differs from vehicle power supply system 1b shown in FIG. 4 in that DC / DC converter 21a outputs 10 V to power supply line PL as set voltage Vs. Further, in the power supply system 1c for a vehicle, nine diodes D1 to D9 are connected in series, and the total on voltage of the diodes D1 to D9 is 6.3 V. Thus, the power supply for a vehicle shown in FIG. Different from system 1b.
　また、車両用電源システム１ｃは、昇降圧コンバータである充電器４の代わりに、充電器６を用いる点で車両用電源システム１ｂと異なる。 Vehicle power supply system 1c is different from vehicle power supply system 1b in that charger 6 is used instead of charger 4 which is a buck-boost converter.
　車両用電源システム１ｃにおいては、電源部２ａが正常に動作している限り、設定電圧Ｖｓすなわち電圧（＋ＢＡＴ）は蓄電池３の放電終止電圧より低い。そのため、充電器６は、電圧（＋ＢＡＴ）を降圧する必要がない。その結果、充電器６として、充電器４よりも簡素な構成で実現でき、従って充電器４よりも低コストである昇圧型のＤＣ／ＤＣコンバータを用いることができる。 In the vehicular power supply system 1c, the set voltage Vs, that is, the voltage (+ BAT) is lower than the discharge termination voltage of the storage battery 3 as long as the power supply unit 2a operates normally. Therefore, the charger 6 does not need to step down the voltage (+ BAT). As a result, as the charger 6, it is possible to use a step-up DC / DC converter that can be realized with a simpler configuration than the charger 4 and therefore cost less than the charger 4.
　即ち、本発明の一局面に従う車両用電源システムは、予め設定された設定電圧の電源電圧を電源ラインへ供給する電源部と、リチウムイオン電池を用いて構成され、前記設定電圧より高い満充電電圧を有する蓄電池と、前記電源部から出力された電源電圧に基づき前記蓄電池を充電する充電部と、直列接続された複数のダイオードとを備え、前記複数のダイオードは、前記蓄電池から前記電源ラインへ向かう方向が順方向になるように、前記蓄電池と前記電源ラインとの間に接続され、前記各ダイオードのオン電圧の合計は、前記設定電圧と前記蓄電池の満充電電圧との差以上であり、かつ前記電源ラインに供給されるべき電圧として予め設定された目標電圧範囲の下限値と前記満充電電圧との差に満たない。 That is, the vehicle power supply system according to one aspect of the present invention is configured using a power supply unit that supplies a power supply voltage of a preset setting voltage to the power supply line, and a lithium ion battery, and a full charge voltage higher than the preset voltage. And a charging unit for charging the storage battery based on the power supply voltage output from the power supply unit, and a plurality of diodes connected in series, the plurality of diodes being directed from the storage battery to the power supply line Connected between the storage battery and the power supply line such that the direction is forward, the total of the on-state voltages of the respective diodes is equal to or greater than the difference between the set voltage and the full charge voltage of the storage battery; The difference between the lower limit value of the target voltage range preset as the voltage to be supplied to the power supply line and the full charge voltage is not satisfied.
　この構成によれば、電源部が正常に動作しているときは、電源部によって、予め設定された設定電圧の電源電圧が電源ラインへ供給されている。また、蓄電池と電源ラインとの間に複数のダイオードが直列に接続されている。そして、各ダイオードのオン電圧の合計は、設定電圧すなわち電源ラインの電圧と蓄電池の満充電電圧との差以上である。従って、充電部が蓄電池を満充電しても、複数のダイオードはオフしたままとなる。その結果、充電部による充電電流が複数のダイオードを介して電源ラインへ流れ出すことが防止され、充電電流の流出による電力損失が防止される。また、各ダイオードのオン電圧の合計は、電源ラインに供給されるべき電圧として予め設定された目標電圧範囲の下限値と蓄電池の満充電電圧との差に満たない。従って、電源部が正常に動作しなくなって電源電圧が低下したとき、電源ラインの電圧が目標電圧範囲の下限値を下回る前に複数のダイオードがオンして蓄電池から電源ラインへ電圧が供給される。この場合、蓄電池の放電を開始するために、背景技術で必要とされていた充電器の動作制御のための制御時間が不要である。従って、電源部からの電源ラインへの供給電圧が低下した場合に、蓄電池から電源ラインへ電圧供給が開始されるまでの時間を短縮することが容易である。 According to this configuration, when the power supply unit is operating normally, the power supply unit supplies the power supply voltage of the preset voltage set to the power supply line. Further, a plurality of diodes are connected in series between the storage battery and the power supply line. The sum of the on-state voltages of the respective diodes is equal to or greater than the set voltage, ie, the difference between the voltage of the power supply line and the full charge voltage of the storage battery. Therefore, even if the charging unit fully charges the storage battery, the plurality of diodes remain off. As a result, the charging current from the charging unit is prevented from flowing out to the power supply line through the plurality of diodes, and the power loss due to the outflow of the charging current is prevented. Further, the total of the on-state voltages of the respective diodes does not satisfy the difference between the lower limit value of the target voltage range preset as the voltage to be supplied to the power supply line and the full charge voltage of the storage battery. Therefore, when the power supply unit does not operate normally and the power supply voltage drops, a plurality of diodes are turned on before the voltage of the power supply line falls below the lower limit of the target voltage range, and a voltage is supplied from the storage battery to the power supply line . In this case, the control time for the operation control of the charger, which is required in the background art, is not necessary to start discharging the storage battery. Therefore, when the supply voltage from the power supply unit to the power supply line is reduced, it is easy to shorten the time until the voltage supply from the storage battery to the power supply line is started.
　また、前記複数のダイオードのうち一つを除く残余のダイオードを短絡するスイッチング素子と、前記電源部による前記電源電圧の供給における不足の有無を判定する判定部と、前記判定部によって前記供給の不足が有ると判定された場合、前記スイッチング素子をオンさせる制御部とを備えることが好ましい。 In addition, a switching element that shorts the remaining diodes except one of the plurality of diodes, a determination unit that determines presence or absence of a shortage in supply of the power supply voltage by the power supply unit, and a shortage of the supply by the determination unit It is preferable to include a control unit that turns on the switching element when it is determined that there is a.
　この構成によれば、例えば電源部が正常に動作しなくなって電源電圧の供給が不足したとき、判定部によって電源電圧の供給不足が有ると判定される。電源電圧の供給が不足すると、電源ラインの電圧が低下して複数のダイオードがオンし、蓄電池から電源ラインへ電流が供給される。しかしながら、各ダイオードに電流が流れると、順方向電圧の電圧降下が生じ、電力損失が発生する。 According to this configuration, for example, when the power supply unit does not operate normally and the supply of the power supply voltage is insufficient, the determination unit determines that the supply of the power supply voltage is insufficient. When the supply of the power supply voltage is insufficient, the voltage of the power supply line is lowered to turn on the plurality of diodes, and a current is supplied from the storage battery to the power supply line. However, when current flows in each diode, a forward voltage drop occurs and a power loss occurs.
　そこで、制御部は、判定部によって電源電圧供給の不足が有ると判定された場合、スイッチング素子をオンする。その結果、蓄電池の放電電流は、ダイオードを一つ残して他のダイオードをバイパスして流れる。これにより、ダイオードによる電圧降下が減少し、電力損失が低減される。また、スイッチング素子をオンしても、蓄電池と電源ラインとの間にダイオードが１つ残るので、電源ラインから蓄電池への逆流が防止される。 Therefore, the control unit turns on the switching element when the determination unit determines that the supply of the power supply voltage is insufficient. As a result, the discharge current of the storage battery bypasses the other diode leaving one diode. This reduces the voltage drop across the diode and reduces power dissipation. Also, even if the switching element is turned on, one diode remains between the storage battery and the power supply line, so that backflow from the power supply line to the storage battery is prevented.
　また、前記蓄電池の充放電電流を検出する電流検出部をさらに備え、前記判定部は、前記電流検出部によって検出された充放電電流が放電方向の電流であった場合、前記供給の不足が有ると判定することが好ましい。 Furthermore, a current detection unit for detecting the charge and discharge current of the storage battery is further provided, and the determination unit has the shortage of the supply when the charge and discharge current detected by the current detection unit is a current in the discharge direction. It is preferable to determine
　例えば電源部が正常に動作しなくなって電源電圧の供給が不足し、電源ラインの電圧が低下すると、複数のダイオードがオンして蓄電池が放電を開始する。従って、電流検出部によって検出された充放電電流が放電方向の電流であった場合、判定部は、電源供給の不足が有ると判定することができる。 For example, when the power supply unit does not operate normally and the supply of the power supply voltage is insufficient and the voltage of the power supply line decreases, the plurality of diodes turn on and the storage battery starts discharging. Therefore, when the charge / discharge current detected by the current detection unit is a current in the discharge direction, the determination unit can determine that there is a shortage of power supply.
　また、前記電源ラインの電圧を検出する電圧検出部をさらに備え、前記判定部は、前記電圧検出部によって検出された電圧が、前記設定電圧に満たない電圧に予め設定された閾値電圧を下回った場合、前記供給の不足が有ると判定するようにしてもよい。 The voltage detection unit further includes a voltage detection unit that detects the voltage of the power supply line, and the determination unit determines that the voltage detected by the voltage detection unit falls below a threshold voltage preset to a voltage that does not meet the set voltage. In this case, it may be determined that there is a shortage of the supply.
　電源部が正常に動作し、電源供給が不足していなければ、電源ラインの電圧は設定電圧に保たれる。従って、電圧検出部によって検出された電圧が、設定電圧に満たない電圧に予め設定された閾値電圧を下回った場合、判定部は、電源供給の不足が有ると判定することができる。 If the power supply unit operates normally and the power supply is not insufficient, the voltage of the power supply line is maintained at the set voltage. Therefore, when the voltage detected by the voltage detection unit falls below a threshold voltage preset to a voltage less than the set voltage, the determination unit can determine that there is a shortage of power supply.
　また、前記ダイオードの数は、３個以上であり、前記電源ラインの電圧を検出する電圧検出部と、前記複数のダイオードのうちいずれかを短絡すると共に、短絡されるダイオードの数を変更可能な短絡部と、前記電圧検出部によって検出された電圧が前記設定電圧に満たない電圧に予め設定された閾値電圧を下回った場合、前記短絡部によって短絡されるダイオードの数を、前記電圧検出部によって検出される電圧が前記設定電圧以上になるまで順次増加させる制御部を備えることが好ましい。 Further, the number of the diodes is three or more, and a voltage detection unit for detecting the voltage of the power supply line and any one of the plurality of diodes can be short-circuited and the number of diodes short-circuited can be changed. The voltage detector detects the number of diodes short-circuited by the short circuit and the number of diodes shorted by the short circuit when the voltage detected by the voltage detector falls below a threshold voltage preset to a voltage less than the set voltage. It is preferable to include a control unit that sequentially increases the detected voltage until it reaches the set voltage or more.
　この構成によれば、電源部による電源供給が不足して電源ラインの電圧が低下すると、まず複数のダイオードがオンして蓄電池から電源ラインへの放電が開始される。このとき、ダイオードの個数分、電圧降下が生じる。そこで、制御部は、短絡部によって短絡されるダイオードの数を、順次増加させる。そうすると、短絡されるダイオードの数が増加する都度、放電電流がバイパスするダイオードの数が増加し、電圧降下が減少する。電圧降下が減少すると、電圧検出部によって検出される電圧すなわち電源ラインの電圧が上昇する。制御部は、電源ラインの電圧が設定電圧以上になるまで短絡部によって短絡されるダイオードの数を順次増加させ、電源ラインの電圧が設定電圧以上になるとそれ以上、短絡されるダイオードの数を増加させない。従って、電源ラインの電圧が、設定電圧を僅かに超える程度の電圧に維持される。これにより、電源部の故障等により電源供給が不足した場合であっても、電源ラインの電圧を設定電圧に近い電圧に維持することが可能となる。 According to this configuration, when the power supply by the power supply unit is insufficient and the voltage of the power supply line decreases, first, the plurality of diodes are turned on to start discharging the storage battery to the power supply line. At this time, a voltage drop occurs by the number of diodes. Therefore, the control unit sequentially increases the number of diodes short-circuited by the short circuit. Then, as the number of shorted diodes increases, the number of diodes to which the discharge current bypasses increases and the voltage drop decreases. When the voltage drop decreases, the voltage detected by the voltage detection unit, that is, the voltage of the power supply line rises. The control unit sequentially increases the number of diodes shorted by the shorting unit until the voltage of the power supply line becomes equal to or higher than the set voltage, and increases the number of diodes shorted further when the voltage of the power supply line becomes equal to or higher than the set voltage. I will not let you. Therefore, the voltage of the power supply line is maintained at a voltage slightly higher than the set voltage. As a result, even when the power supply is insufficient due to a failure of the power supply unit or the like, the voltage of the power supply line can be maintained at a voltage close to the set voltage.
　また、前記制御部は、前記短絡部によって短絡されるダイオードの数を増加させる際に、一つのダイオードを短絡させてから次のダイオードを短絡させるまでの時間を、予め設定された設定時間以上とすることが好ましい。 In addition, when increasing the number of diodes short-circuited by the short circuit, the control unit may set a time from the short-circuiting of one diode to the short-circuiting of the next diode not less than a preset setting time. It is preferable to do.
　制御部が複数のダイオードを順次短絡させると電源ラインの電圧が上昇する。しかしながら、電源ラインから電源電圧の供給を受ける負荷は、急激に電源電圧が上昇すると動作が不安定になり易い。そこで、制御部は、複数のダイオードを順次短絡させる際に、一つのダイオードを短絡させてから次のダイオードを短絡させるまでの間に、予め設定された設定時間以上の時間を空けることで、電源ラインの電圧を緩やかに上昇させる。その結果、電源ラインから電源電圧の供給を受ける負荷の動作の安定性が向上する。 When the control unit shorts the plurality of diodes sequentially, the voltage of the power supply line rises. However, the load receiving the supply of the power supply voltage from the power supply line is likely to become unstable in operation if the power supply voltage rises rapidly. Therefore, when sequentially short-circuiting a plurality of diodes, the control unit allows a time longer than a preset setting time to short-circuit one diode and then short-circuit the next diode. Slowly raise the line voltage. As a result, the stability of the operation of the load receiving the supply of the power supply voltage from the power supply line is improved.
　また、ユーザが操作可能な操作スイッチをさらに備え、前記制御部は、前記電源電圧を動作用電源電圧として動作するものであり、前記操作スイッチは、操作された場合に前記蓄電池の出力電圧を前記制御部の動作用電源電圧として供給することが好ましい。 The control unit may further operate using the power supply voltage as a power supply voltage for operation, and the operation switch may output an output voltage of the storage battery when the operation switch is operated. It is preferable to supply as an operation power supply voltage of the control unit.
　蓄電池の出力電圧が低下している状態で、複数のダイオードがオンして蓄電池の出力電圧が電源ラインへ供給された場合、蓄電池から出力された電圧に対して複数のダイオードによる電圧降下が生じると、蓄電池からの電源電圧の供給に不足が生じるために電源ラインの電圧が、制御部が動作するために必要な電圧に満たなくなるおそれがある。このような場合、ユーザが操作スイッチを操作することで、蓄電池の出力電圧を直接制御部の動作用電源電圧として供給することができる。そして、制御部は、蓄電池の出力電圧により動作可能となると、スイッチング素子をオンさせてダイオードによる電圧降下を減少させることが可能となる。ダイオードによる電圧降下が減少すると、電源ラインの電圧が上昇する。これにより、蓄電池の出力電圧は制御部の動作に必要な電圧以上であるにもかかわらず、ダイオードによる電圧降下のために、電源ラインの電圧では制御部が動作しない状態になった場合であっても、ユーザが操作スイッチを操作することで、制御部を起動することが可能となる。 When a plurality of diodes are turned on and the output voltage of the storage battery is supplied to the power supply line while the output voltage of the storage battery is decreasing, a voltage drop due to the plurality of diodes occurs with respect to the voltage output from the storage battery Since the supply of the power supply voltage from the storage battery is insufficient, the voltage of the power supply line may not reach the voltage required for the control unit to operate. In such a case, when the user operates the operation switch, the output voltage of the storage battery can be directly supplied as the operation power supply voltage of the control unit. Then, when the control unit becomes operable by the output voltage of the storage battery, it is possible to turn on the switching element to reduce the voltage drop due to the diode. As the voltage drop across the diode decreases, the voltage on the power supply line rises. Thus, although the output voltage of the storage battery is equal to or higher than the voltage required for the operation of the control unit, the control unit does not operate with the voltage of the power supply line due to the voltage drop due to the diode. Also, the user can activate the control unit by operating the operation switch.
　また、前記蓄電池は、前記リチウムイオン電池が４個直列接続されて構成されていることが好ましい。 Moreover, it is preferable that four said lithium ion batteries are connected in series, and the said storage battery is comprised.
　この構成によれば、蓄電池の出力電圧は、約１１Ｖ～１６Ｖ程度となるので、１２Ｖ出力の鉛蓄電池の代わりに上記蓄電池を用いることが容易である。 According to this configuration, since the output voltage of the storage battery is about 11V to 16V, it is easy to use the above storage battery instead of the lead storage battery of 12V output.
　また、前記設定電圧は、１２Ｖであり、前記充電部は、前記電源電圧を昇圧及び降圧可能な昇降圧コンバータであることが好ましい。 Preferably, the set voltage is 12 V, and the charging unit is a buck-boost converter capable of stepping up and down the power supply voltage.
　この構成によれば、電源部として、１２Ｖ出力の鉛蓄電池と組み合わせて用いられるＤＣ／ＤＣコンバータやオルタネータをそのまま用いることが容易である。 According to this configuration, it is easy to use a DC / DC converter or an alternator, which is used in combination with a 12 V lead storage battery, as it is.
　また、前記設定電圧は、前記蓄電池の放電を停止させるべき電圧として予め設定された放電終止電圧より低い電圧であり、前記充電部は、前記電源電圧を昇圧可能な昇圧コンバータとしてもよい。 The set voltage may be a voltage lower than a discharge termination voltage preset as a voltage to stop the discharge of the storage battery, and the charging unit may be a boost converter capable of boosting the power supply voltage.
　この構成によれば、電源ラインの電源電圧が蓄電池の出力電圧より高くなることがない。従って、充電部は、電源電圧を降圧する必要がないので、充電部を昇圧コンバータによって構成することができる。そうすると、充電部を昇降圧コンバータによって構成する場合に比べてコストを低減することができる。 According to this configuration, the power supply voltage of the power supply line does not become higher than the output voltage of the storage battery. Therefore, since the charging unit does not need to step down the power supply voltage, the charging unit can be configured by a boost converter. Then, the cost can be reduced as compared to the case where the charging unit is configured by a buck-boost converter.
　このような構成の車両用電源システムは、電源部からの電源ラインへの供給電圧が低下した場合に、蓄電池から電源ラインへ電圧供給が開始されるまでの時間を短縮することが容易である。 In the power supply system for vehicles having such a configuration, when the supply voltage from the power supply unit to the power supply line is reduced, it is easy to shorten the time until the voltage supply from the storage battery to the power supply line is started.
　この出願は、２０１１年６月６日に出願された日本国特許出願特願２０１１－１２６３６２を基礎とするものであり、その内容は、本願に含まれるものである。 This application is based on Japanese Patent Application No. 2011-126362 filed on Jun. 6, 2011, the contents of which are included in the present application.
　なお、発明を実施するための形態の項においてなされた具体的な実施態様又は実施例は、あくまでも、本発明の技術内容を明らかにするものであって、本発明は、そのような具体例にのみ限定して狭義に解釈されるべきものではない。 The specific embodiments or examples made in the section of the mode for carrying out the invention merely clarify the technical contents of the present invention, and the present invention relates to such specific examples. It should not be interpreted only in a narrow sense.
　本発明に係る車両用電源システムは、車両に搭載される蓄電池を用いた車両用電源システムとして有用である。 The power supply system for vehicles which concerns on this invention is useful as a power supply system for vehicles using the storage battery mounted in a vehicle.

Claims (10)

  1. 　予め設定された設定電圧の電源電圧を電源ラインへ供給する電源部と、
    　リチウムイオン電池を用いて構成され、前記設定電圧より高い満充電電圧を有する蓄電池と、
    　前記電源部から出力された電源電圧に基づき前記蓄電池を充電する充電部と、
    　直列接続された複数のダイオードとを備え、
    　前記複数のダイオードは、
    　前記蓄電池から前記電源ラインへ向かう方向が順方向になるように、前記蓄電池と前記電源ラインとの間に接続され、
    　前記各ダイオードのオン電圧の合計は、前記設定電圧と前記蓄電池の満充電電圧との差以上であり、かつ前記電源ラインに供給されるべき電圧として予め設定された目標電圧範囲の下限値と前記満充電電圧との差に満たない車両用電源システム。     A power supply unit that supplies a power supply voltage of a preset setting voltage to a power supply line;
    A storage battery configured using a lithium ion battery and having a full charge voltage higher than the set voltage;
    A charging unit that charges the storage battery based on a power supply voltage output from the power supply unit;
    And a plurality of diodes connected in series,
    The plurality of diodes are
    It is connected between the storage battery and the power supply line such that the direction from the storage battery to the power supply line is forward.
    The sum of the on voltage of each of the diodes is equal to or greater than the difference between the set voltage and the full charge voltage of the storage battery, and the lower limit value of the target voltage range preset as the voltage to be supplied to the power supply line Power supply system for vehicles that does not meet the difference with full charge voltage.
  2. 　前記複数のダイオードのうち一つを除く残余のダイオードを短絡するスイッチング素子と、
    　前記電源部による前記電源電圧の供給における不足の有無を判定する判定部と、
    　前記判定部によって前記供給の不足が有ると判定された場合、前記スイッチング素子をオンさせる制御部とを備える請求項１記載の車両用電源システム。     A switching element for shorting the remaining diodes except one of the plurality of diodes;
    A determination unit that determines presence or absence of a shortage in supply of the power supply voltage by the power supply unit;
    The vehicle power supply system according to claim 1, further comprising: a control unit that turns on the switching element when it is determined by the determination unit that there is a shortage of the supply.
  3. 　前記蓄電池の充放電電流を検出する電流検出部をさらに備え、
    　前記判定部は、
    　前記電流検出部によって検出された充放電電流が放電方向の電流であった場合、前記供給の不足が有ると判定する請求項２記載の車両用電源システム。     It further comprises a current detection unit that detects the charge and discharge current of the storage battery,
    The determination unit is
    The power supply system for a vehicle according to claim 2, wherein if the charge / discharge current detected by the current detection unit is a current in the discharge direction, it is determined that the supply is insufficient.
  4. 　前記電源ラインの電圧を検出する電圧検出部をさらに備え、
    　前記判定部は、
    　前記電圧検出部によって検出された電圧が、前記設定電圧に満たない電圧に予め設定された閾値電圧を下回った場合、前記供給の不足が有ると判定する請求項２記載の車両用電源システム。     It further comprises a voltage detection unit for detecting the voltage of the power supply line,
    The determination unit is
    The power supply system for a vehicle according to claim 2, wherein it is determined that the supply is insufficient when the voltage detected by the voltage detection unit is lower than a threshold voltage preset to a voltage less than the set voltage.
  5. 　前記ダイオードの数は、３個以上であり、
    　前記電源ラインの電圧を検出する電圧検出部と、
    　前記複数のダイオードのうちいずれかを短絡すると共に、短絡されるダイオードの数を変更可能な短絡部と、
    　前記電圧検出部によって検出された電圧が前記設定電圧に満たない電圧に予め設定された閾値電圧を下回った場合、前記短絡部によって短絡されるダイオードの数を、前記電圧検出部によって検出される電圧が前記設定電圧以上になるまで順次増加させる制御部を備える請求項１記載の車両用電源システム。     The number of the diodes is three or more,
    A voltage detection unit that detects a voltage of the power supply line;
    A short circuit which can short any one of the plurality of diodes and change the number of shorted diodes;
    When the voltage detected by the voltage detection unit falls below a threshold voltage preset to a voltage less than the set voltage, the number of diodes short-circuited by the short circuit is detected by the voltage detection unit The power supply system for a vehicle according to claim 1, further comprising: a control unit that sequentially increases the voltage until the voltage exceeds the set voltage.
  6. 　前記制御部は、
    　前記短絡部によって短絡されるダイオードの数を増加させる際に、一つのダイオードを短絡させてから次のダイオードを短絡させるまでの時間を、予め設定された設定時間以上とする請求項５記載の車両用電源システム。     The control unit
    The vehicle according to claim 5, wherein the time from the short circuit of one diode to the short circuit of the next diode is equal to or longer than a preset set time when increasing the number of diodes shorted by the short circuit portion. Power supply system.
  7. 　ユーザが操作可能な操作スイッチをさらに備え、
    　前記制御部は、
    　前記電源電圧を動作用電源電圧として動作するものであり、
    　前記操作スイッチは、
    　操作された場合に前記蓄電池の出力電圧を前記制御部の動作用電源電圧として供給する請求項２又は５記載の車両用電源システム。     It also has an operation switch that can be operated by the user
    The control unit
    The power supply voltage operates as a power supply voltage for operation,
    The operation switch is
    The power supply system for vehicles according to claim 2 or 5 which supplies an output voltage of said storage battery as operation power supply voltage of said control part, when it was operated.
  8. 　前記蓄電池は、
    　前記リチウムイオン電池が４個直列接続されて構成されている請求項１～７のいずれか１項に記載の車両用電源システム。     The storage battery is
    The vehicle power supply system according to any one of claims 1 to 7, wherein four lithium ion batteries are connected in series.
  9. 　前記設定電圧は、１２Ｖであり、
    　前記充電部は、前記電源電圧を昇圧及び降圧可能な昇降圧コンバータである請求項８記載の車両用電源システム。     The set voltage is 12 V,
    The vehicle power supply system according to claim 8, wherein the charging unit is a buck-boost converter capable of boosting and stepping down the power supply voltage.
  10. 　前記設定電圧は、前記蓄電池の放電を停止させるべき電圧として予め設定された放電終止電圧より低い電圧であり、
    　前記充電部は、前記電源電圧を昇圧可能な昇圧コンバータである請求項８記載の車両用電源システム。     The set voltage is a voltage lower than a discharge termination voltage preset as a voltage to stop the discharge of the storage battery,
    The vehicle power supply system according to claim 8, wherein the charging unit is a boost converter capable of boosting the power supply voltage.
PCT/JP2012/003658 2011-06-06 2012-06-04 Vehicle power-supply system WO2012169171A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011-126362 2011-06-06
JP2011126362A JP2014150593A (en) 2011-06-06 2011-06-06 Power supply system for vehicle

Publications (1)

Publication Number Publication Date
WO2012169171A1 true WO2012169171A1 (en) 2012-12-13

Family

ID=47295756

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/003658 WO2012169171A1 (en) 2011-06-06 2012-06-04 Vehicle power-supply system

Country Status (2)

Country Link
JP (1) JP2014150593A (en)
WO (1) WO2012169171A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017143682A (en) * 2016-02-12 2017-08-17 株式会社日本製鋼所 Backup storage battery of power supply for controlling industrial machine
WO2018135668A1 (en) * 2017-01-23 2018-07-26 ヤマハ発動機株式会社 Lithium ion battery pack
EP3275720A4 (en) * 2015-03-27 2018-10-31 Kabushiki Kaisha Toshiba Auxiliary power supply device

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9927998B2 (en) 2014-02-05 2018-03-27 Tidal Systems, Inc. Flash memory compression
KR101779942B1 (en) 2015-02-24 2017-10-10 주식회사 엘지화학 Integrated power supply device in hybrid vehicle
JP6458712B2 (en) * 2015-11-13 2019-01-30 トヨタ自動車株式会社 Vehicle power supply system
JP2017118788A (en) * 2015-12-25 2017-06-29 カルソニックカンセイ株式会社 Storage battery system
JP6704895B2 (en) 2017-12-20 2020-06-03 株式会社Ｓｕｂａｒｕ Electric vehicle power supply system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03293939A (en) * 1990-04-06 1991-12-25 Nippon Telegr & Teleph Corp <Ntt> Dc power supply system
JPH04265641A (en) * 1991-02-19 1992-09-21 Nippon Telegr & Teleph Corp <Ntt> Dc uninterruptive power feeder
JP2011109745A (en) * 2009-11-13 2011-06-02 Panasonic Corp Energy storage device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03293939A (en) * 1990-04-06 1991-12-25 Nippon Telegr & Teleph Corp <Ntt> Dc power supply system
JPH04265641A (en) * 1991-02-19 1992-09-21 Nippon Telegr & Teleph Corp <Ntt> Dc uninterruptive power feeder
JP2011109745A (en) * 2009-11-13 2011-06-02 Panasonic Corp Energy storage device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3275720A4 (en) * 2015-03-27 2018-10-31 Kabushiki Kaisha Toshiba Auxiliary power supply device
JP2017143682A (en) * 2016-02-12 2017-08-17 株式会社日本製鋼所 Backup storage battery of power supply for controlling industrial machine
WO2018135668A1 (en) * 2017-01-23 2018-07-26 ヤマハ発動機株式会社 Lithium ion battery pack

Also Published As

Publication number Publication date
JP2014150593A (en) 2014-08-21

Similar Documents

Publication Publication Date Title
WO2012169171A1 (en) Vehicle power-supply system
JP5865013B2 (en) Power supply device for vehicle and vehicle provided with this power supply device
US10710469B2 (en) Automotive dual voltage battery charging system
CN102668229B (en) Battery temperature elevating circuit and battery temperature elevating device
EP2272722B1 (en) Power source apparatus for vehicle
US7832513B2 (en) Vehicular electrical system and control method therefor
US8134338B2 (en) Battery management system and driving method thereof
US8487558B2 (en) Electric vehicle
US9843184B2 (en) Voltage conversion apparatus
EP2200146A1 (en) Power supply device
US20090050092A1 (en) Engine Start Device
AU2016102104B4 (en) Apparatus for starting an electrically cranked engine
US10361572B2 (en) Power supply component and power supply method
CN113711457A (en) Conversion device, conversion system, switching device, vehicle including these devices, and control method
US8890488B2 (en) Power supply apparatus and method of controlling the same
KR101795169B1 (en) Method for jumping ignition of battery
US20200395780A1 (en) Charge control apparatus, energy storage apparatus, and charging method
JP2004023803A (en) Voltage controller for battery pack
US7477040B2 (en) Circuit for a motor vehicle electrical distribution system and an associated operating method
JP2012035756A (en) Power supply device for vehicle
JP2002281609A (en) Combined secondary battery circuit and regenerative control system
JP6409635B2 (en) Power storage system
JP6969200B2 (en) Power system
JP2008253083A (en) Power supply device for mobile vehicle
CN112649748A (en) Method for determining the state of charge of a low-voltage battery of a motor vehicle

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12796081

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12796081

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP