CN108352719B - Power supply device - Google Patents

Power supply device Download PDF

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Publication number
CN108352719B
CN108352719B CN201680060735.0A CN201680060735A CN108352719B CN 108352719 B CN108352719 B CN 108352719B CN 201680060735 A CN201680060735 A CN 201680060735A CN 108352719 B CN108352719 B CN 108352719B
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China
Prior art keywords
battery
switch
switches
power supply
state
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CN201680060735.0A
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Chinese (zh)
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CN108352719A (en
Inventor
铃木良规
渡边裕介
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Denso Corp
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Denso Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R16/00—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for
    • B60R16/02—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for electric constitutive elements
    • B60R16/03—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for electric constitutive elements for supply of electrical power to vehicle subsystems or for
    • 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
    • H01M10/486—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte for measuring temperature
    • 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
    • H01M10/482—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte for several batteries or cells simultaneously or sequentially
    • 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
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/14—Balancing the load in a network
    • 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
    • H02J7/14—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
    • H02J7/1423—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle with multiple batteries
    • 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
    • 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
    • H02J2310/46—The network being an on-board power network, i.e. within a vehicle for ICE-powered road vehicles
    • 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
    • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
    • Y02T10/92—Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

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  • 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)
  • Mechanical Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Secondary Cells (AREA)
  • Control Of Charge By Means Of Generators (AREA)

Abstract

The present invention relates to a power supply device. A power supply system to which the power supply device is applied is provided with: and a1 st battery and a2 nd battery connected in parallel to the rotating electric machine having at least a power generation function. The power supply device includes: a1 st branch path and a2 nd branch path branched between a1 st point connected to the rotating electrical machine and a2 nd point connected to the 2 nd storage battery; the 1 st switch is arranged on the 1 st branch path; a2 nd switch and a 3 rd switch provided in series in the 2 nd branch path; a 4 th switch provided in an energization path between the 1 st point or any one of the 2 nd switch and the 3 rd point between the 3 rd switch and the 1 st battery; and a control unit for controlling the opening and closing of the 1 st to 4 th switches.

Description

Power supply device
Technical Field
The present invention relates to a power supply device mounted on a vehicle or the like.
Background
For example, as an in-vehicle power supply system mounted on a vehicle, there is known a configuration in which: a plurality of storage batteries such as lead storage batteries and lithium ion storage batteries are used, and power is supplied to various loads mounted on a vehicle by using the respective storage batteries separately (for example, see patent document 1). For example, a switch is provided in an electric path from the generator to each of the storage batteries, and the switch is controlled based on the storage power of each of the storage batteries, so that the generator charges any of the storage batteries.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open No. 2012-130108
Disclosure of Invention
Technical problem to be solved by the invention
Here, when a plurality of storage batteries are used, it is conceivable that the storage batteries have different properties and different storage states. In this case, if each battery is used without considering the difference in properties and states, there is a possibility that a problem such as an excessive pressure is applied to each battery. This allows for improvement in the related aspects.
The present invention has been made in view of the above problems, and a main object thereof is to provide a power supply device capable of performing charging and discharging of each storage battery while reducing the pressure on each storage battery.
Technical scheme for solving technical problem
A power supply device according to a first aspect of the present invention is a power supply device applied to a power supply system including a1 st storage battery and a2 nd storage battery, the 1 st storage battery and the 2 nd storage battery being connected in parallel to a rotating electric machine having at least a power generation function. The power supply device includes: a1 st branch path and a2 nd branch path branched between a1 st point connected to the rotating electrode and a2 nd point connected to the 2 nd secondary battery; a1 st switch, the 1 st switch being provided in the 1 st branch path; a2 nd switch and a 3 rd switch, the 2 nd switch and the 3 rd switch being arranged in series in the 2 nd branch path; a 4 th switch provided in a current-carrying path between the 1 st point or any one of the 3 rd points between the 2 nd switch and the 3 rd switch and the 1 st battery; and a control unit that controls opening and closing of each of the 1 st to 4 th switches.
In the power supply device according to the above-mentioned 1 st aspect, a1 st branch path and a2 nd branch path are provided by branching between a1 st point connected to the rotating electrode and a2 nd point connected to the 2 nd battery, a1 st switch is provided in the 1 st branch path, and a2 nd switch and a 3 rd switch are provided in series in the 2 nd branch path. Thus, a closed circuit with the 1 st to 3 rd switches is formed between the 1 st and 2 nd points (i.e., between the 2 nd battery and the rotating electrode). In the configuration, the control unit can selectively connect the 2 nd battery and the rotating electric machine through two current-carrying paths (the 1 st branch path and the 2 nd branch path). In this case, when the control unit individually controls the opening and closing of each of the 1 st to 3 rd switches in each branch path, the wiring resistance between the 2 nd battery and the rotating electric machine is varied by the resistance (on-resistance) of the switch, and the magnitude of the current flowing through the 2 nd battery can be adjusted. By adjusting the current of the 2 nd battery, the current distribution between the 1 st battery and the 2 nd battery can be changed. That is, the current flowing through the 1 st battery connected to the 1 st point or the 3 rd point via the 4 th switch can be adjusted for the 1 st battery. Therefore, the batteries can be used while taking into consideration differences in properties and states. As a result, the charge and discharge of each battery can be appropriately performed.
In the configuration in which the closed circuit including the 1 st to 3 rd switches is formed, even if any one of the switches is abnormal in opening (abnormal in opening), the control unit closes both the switches, and thereby the current between the 2 nd battery and the rotating electric machine is continuously supplied.
In the power supply device according to the second aspect of the present invention, an electric load is connected to the 3 rd point.
In the configuration in which the electrical load is connected to the 3 rd point on the 2 nd branch path, the wiring resistance between the 2 nd battery and the electrical load can be made different by controlling the opening and closing of the 1 st to 3 rd switches by the control unit. Therefore, the magnitude of the discharge current discharged from the 2 nd battery to the electrical load, that is, the discharge load of the 2 nd battery can be adjusted. This can suppress energy loss during driving of the electric load.
In the power supply device according to a third aspect of the present invention, the control unit closes each of the 1 st to 3 rd switches in a state where the 4 th switch is opened.
In the above configuration, the 4 th switch is turned on by the control unit, so that the 2 nd battery out of the 1 st battery and the 2 nd battery can be preferentially used to discharge the electric load. In this case, the control unit closes all of the 1 st to 3 rd switches, thereby reducing the wiring resistance and discharging the electric load from the 2 nd battery.
In the power supply device according to the fourth aspect of the present invention, when the rotating electric machine and the electric load are simultaneously supplied with power and are brought into the driving state, the control unit closes the 4 th switch, opens two switches connected to one of the 1 st point and the 3 rd point on one end side of the 4 th switch among the 1 st switch to the 3 rd switch, and closes the remaining one switch.
Fig. 4(b) and 9(b) show the state corresponding to the fourth aspect of the present invention. That is, fig. 4(b) shows the following state: the 4 th switch (SW1) is turned on, and among the 1 st to 3 rd switches (SW11 to SW13), two switches (SW11 and SW12) connected to the 1 st point (N1) on one end side of the 4 th switch are turned off, and the remaining one switch (SW13) is turned on. Further, fig. 9(b) shows the following state: the 4 th switch (SW1) is turned on, and among the 1 st to 3 rd switches (SW11 to SW13), two switches (SW12 and SW13) connected to the 3 rd point (N3) on one end side of the 4 th switch are turned off, and the remaining one switch (SW11) is turned on.
In this case, the power supply path to the rotary electric machine and the power supply path to the electric load are disconnected by the switches (SW11, SW12 in fig. 4(b), SW12, SW13 in fig. 9 (b)) in the off state. Therefore, in a state where the rotating electrical machine and the electric load are driven together, the influence of the voltage variation of the battery due to the driving of the rotating electrical machine is exerted on the driving of the electric load.
In the power supply apparatus according to the fifth aspect of the present invention, the electric load is a constant-voltage required load that is a stable electric load requiring a constant supply voltage or a fluctuation of the supply voltage at least within a predetermined range.
When the electric load is a constant-voltage-required load, the power supply voltage fluctuates as the rotating electric machine is driven, and the operation of the electric load may become unstable. In this regard, by disconnecting the power supply path to the rotating electrical machine and the power supply path to the electrical load as described above, a stable operation of the constant voltage requiring load can be achieved.
In a power supply device according to a sixth embodiment of the present disclosure, the control unit switches the 1 st to 3 rd switches between two states: i.e. a state in which all switches are closed, and a state in which at least one switch is open.
As described above, in the configuration in which the 1 st branch path and the 2 nd branch path are provided with the 1 st to 3 rd switches, the resistance value between the 1 st point and the 2 nd point, and the resistance value between the 2 nd point and the 3 rd point can be changed by switching the state in which all the switches are closed and the state in which at least one switch is opened by the control unit for the 1 st to 3 rd switches. This makes it possible to increase or decrease the wiring resistance between the 2 nd battery and the rotating electric machine or the wiring resistance between the 2 nd battery and the electric load, and further to change the state of charge and discharge in the 2 nd battery.
In a power supply device according to a seventh aspect of the present invention, the control unit controls opening and closing of each of the 1 st to 3 rd switches individually in a state where the 4 th switch is opened.
When the 4 th switch is closed by the control unit, the 1 st battery is in a state of being electrically connected to the 1 st point or the 3 rd point, that is, the 1 st battery and the rotating electric machine are in an electrically connected state, or the 1 st battery and the electric load are in an electrically connected state. In this state, the control unit individually controls the opening and closing of the 1 st to 3 rd switches, so that, for example, for the rotating electric machine, the charge/discharge sharing ratio of each battery can be adjusted when the 1 st battery and the 2 nd battery are turned on. This enables the pressure for use of each battery to be appropriately adjusted.
In the power supply device according to the eighth aspect of the present invention, the control unit controls the opening and closing of each of the 1 st to 4 th switches based on a parameter including at least one of a state of charge and a temperature of each of the 1 st and 2 nd batteries.
For example, when a charge/discharge current flows in the 2 nd battery, a decrease in the amount of stored electricity and an increase in the battery temperature due to the current flow occur. In this case, the control unit controls the opening and closing of the switches based on the state of charge and the temperature of each battery, so that the decrease in the excessive amount of charge and the increase in the temperature can be suppressed, and the charging and discharging of each battery can be appropriately performed.
In the power supply device according to a ninth aspect of the present invention, the control unit is configured to determine whether or not there is an abnormality in the 2 nd storage battery, and when it is determined that an abnormality has occurred in the 2 nd storage battery, the control unit closes the 4 th switch, opens two switches connected to the 2 nd point among the 1 st switch to the 3 rd switch, and closes the remaining one switch.
Fig. 4(f) and 9(f) show the states corresponding to the ninth embodiment, for example. That is, fig. 4(f) and 9(f) show the following states: the 4 th switch (SW1) is turned on by the control unit, and of the 1 st to 3 rd switches (SW11 to SW13), two switches (SW11 and SW13) connected to the 2 nd point (N2) are turned off, and the remaining one switch (SW12) is turned on.
In this case, when the 2 nd battery is abnormal, the 2 nd battery is separated from the rotating electric machine and the electric load, and the 1 st battery supplies power to the rotating electric machine and the electric load. Therefore, the rotating electric machine and the electric load can be continuously used even after the abnormality occurs in the 2 nd storage battery.
Drawings
Fig. 1 is a circuit diagram showing a power supply system according to a first embodiment.
Fig. 2 is a diagram for explaining on/off patterns of the 1 st to 3 rd switches shown in fig. 1.
Fig. 3A is a diagram showing an SOC usage range of the lead-acid battery shown in fig. 1.
Fig. 3B is a diagram showing the SOC usage range of the lithium ion battery shown in fig. 1.
Fig. 4 is a diagram showing a vehicle state and states of the switches shown in fig. 1.
Fig. 5 is a diagram showing five discharge states of each battery shown in fig. 1.
Fig. 6 is a timing chart showing a change in voltage at the time of discharge in the lithium-ion battery shown in fig. 1.
Fig. 7 is a flowchart showing a procedure of the switching control executed by the control unit shown in fig. 1.
Fig. 8 is a circuit diagram showing a power supply system according to a second embodiment of the present invention.
Fig. 9 is a diagram showing a vehicle state of the second embodiment and states of the switches shown in fig. 8.
Fig. 10 is a diagram showing five discharge states of each battery shown in fig. 8 in the second embodiment.
Detailed Description
(first embodiment)
Hereinafter, embodiments embodying the present invention will be described based on the drawings. The present embodiment specifically describes an in-vehicle power supply device that supplies power to various devices of a vehicle running on an engine (internal combustion engine) as a drive source.
As shown in fig. 1, the present power supply system is a two-power supply system including a lead storage battery 11 as a1 st storage battery and a lithium ion storage battery 12 as a2 nd storage battery, and is capable of supplying power from the storage batteries 11 and 12 to various electric loads 14 and 15. The batteries 11 and 12 can be charged by the rotating electric machine 16. In the present system, the lead storage battery 11 and the lithium ion storage battery 12 are connected in series with the rotating electrical machine 16, and the lead storage battery 11 and the lithium ion storage battery 12 are connected in parallel with the electrical loads 14, 15.
The lead storage battery 11 is a generally-used storage battery. In contrast, the lithium ion battery 12 is a high-density battery having a smaller power loss during charging and discharging and having a higher output density and energy density than the lead battery 11. The lithium ion battery 12 may have higher energy efficiency in charging and discharging than the lead battery 11.
The electric loads 14 and 15 are different from requests for the voltage of the power supply supplied from the storage batteries 11 and 12. The electric load 15 includes a stable constant voltage demand load that requires a constant or at least a predetermined range of fluctuation of the voltage of the power supply. In contrast, the electrical load 14 is a general electrical load other than the constant voltage-requiring load. The electrical load 15 may also be referred to as a protected load. The electric load 15 is a load that does not allow a power failure, and the electric load 14 is a load that allows a power failure as compared with the electric load 15.
Specific examples of the electric load 15 as the constant voltage required load include various ECUs such as a navigation device, an audio device, a meter device, and an engine ECU. In this case, by suppressing the voltage variation of the power supply, the occurrence of unnecessary reset or the like in each device is suppressed, and stable operation can be achieved. Specific examples of the electric load 14 include a seat heater, a heater for defrosting a rear windshield, a windshield wiper such as a front lamp or a front windshield, and a blower fan of an air conditioner.
The rotating shaft of the rotating electrical machine 16 is drivingly coupled to an engine output shaft, not shown, by a belt or the like, and the rotating shaft of the rotating electrical machine 16 is rotated by the rotation of the engine output shaft, while the engine output shaft is rotated by the rotation of the rotating shaft of the rotating electrical machine 16. In this case, the rotating electrical machine 16 has a power generating function of generating power (regenerative power generation) by the rotation of the engine output shaft and the axle, and a power outputting function of giving a rotational force to the engine output shaft. The rotating electric machine 16 adjusts the generated current during power generation and adjusts the torque during rotational driving by an inverter provided integrally with or separately from the power conversion device.
The rotating electrical machine 16 is an electrical load from the viewpoint of adding power to the engine output shaft, and is a high power/high current load as compared with the electrical load 15. Hereinafter, for convenience of description, the electric load 15 and the rotating electric machine 16 are also collectively referred to as electric loads 15 and 16.
Next, the circuit configuration of the present system will be described in detail.
In this system, a switch SW1 is provided on an electrical path L1 connecting the lead storage battery 11 and the rotating electric machine 16. The position of the electrical path L1 where the switch SW1 is provided is also a position corresponding to an electrical path for connecting the electrical load 15 and the lithium-ion battery 12 to the lead-acid battery 11. The 1 st point N1 on the electrical path L1 is connected to the 1 st branch path L11 and the 2 nd branch path L12. The branch paths L11 and L12 are two paths between the 1 st point N connected to the rotating electric machine 16 and the 2 nd point N2 connected to the positive electrode side of the lithium ion battery 12.
Further, a switch SW11 is provided in the 1 st branch path L11, and a switch SW12 and a switch SW13 are provided in series in the 2 nd branch path L12. That is, a closed circuit having the switches SW11 to SW13 is formed between the 1 st point N1 and the 2 nd point N2. Both ends of each of the switches SW11 to SW13 are connected to each other. The 3 rd point N3 between the switches SW12 and SW13 in the 2 nd branch path L12 is connected to the electric load 15.
The closed circuit including the branch paths L11 and L12 and the switches SW11 to SW13 constitutes the wiring resistance switching unit 20, and the resistance values between the points N1 and N2, the resistance values between the points N1 and N3, and the resistance values between the points N2 and N3 can be changed by turning on and off the switches SW11 to SW 13. The switches SW11 to SW13 correspond to the 1 st switch, the 2 nd switch, and the 3 rd switch, respectively. The switch SW1 corresponds to the 4 th switch.
The switches SW1, SW11 to SW13 are each formed of a semiconductor switching element such as a MOSFET. Further, each of the switches SW1, SW11 to SW13 may be configured to have two MOSFETs in one group, and the parasitic diodes of the MOSFETs in each group may be connected in series so as to be opposite to each other. When the switches SW1, SW11 to SW13 are turned off, the parasitic diodes in opposite directions block the current flowing through the path in which the switches are provided. The switches SW1, SW11 to SW13 may have any configuration using semiconductor switching elements, and for example, parasitic diodes of MOSFETs may not be arranged in opposite directions.
The switches SW1, SW11 to SW13 are turned on, that is, closed, respectively, to turn on the corresponding paths. When the switches SW1, SW11 to SW13 are on, on-resistance is generated in the switches. The on-resistance values of the switches SW1, SW11 to SW13 also depend on the number of semiconductor switching elements. In the present embodiment, the on-resistances of the switches SW11 to SW13 are all set to the same value, but may be different from each other.
In this case, by turning on/off any of the switches SW11 to SW13, the wiring resistance between the lithium-ion battery 12 and the electric load 15 and the wiring resistance between the lithium-ion battery 12 and the rotating electric machine 16 can be changed. Here, the on/off modes of the switches SW11 to SW13 will be described with reference to fig. 2. In fig. 2, only switches in the on state among the switches SW11 to SW13 are shown as R11, R12, and R13.
In fig. 2(a), all of the switches SW11 to SW13 are on. In this case, the combined resistances are formed by the resistances R11 to R13 between the lithium-ion battery 12 and the electric load 15 and between the lithium-ion battery 12 and the rotating electric machine 16, respectively. Therefore, the wiring resistance between the lithium-ion battery 12 and the electric load 15 and the wiring resistance between the lithium-ion battery 12 and the rotating electrical machine 16 are lower than the wiring resistance corresponding to the case where any of the switches SW11 to SW13 described below is in the off state. Therefore, the charge/discharge current of the lithium ion battery 12 is easily made to flow. In this state, even if any one of the three switches SW11 to SW13 has an open failure (open failure), charge and discharge can be continued.
Fig. 3 (b) shows a state where the switch SW11 is off, the switch SW12 is on, and the switch SW13 is on. In this case, the wiring resistance between the lithium-ion battery 12 and the electric load 15 is R13, and the wiring resistance between the lithium-ion battery 12 and the rotating electrical machine 16 is R12+ R13.
Fig. 3 (c) shows a state in which the switch SW11 is on, the switch SW12 is off, and the switch SW13 is on. In this case, the wiring resistance between the lithium-ion battery 12 and the electric load 15 is R13, and the wiring resistance between the lithium-ion battery 12 and the rotating electrical machine 16 is R11.
Fig. 3 (d) shows a state in which the switch SW11 is on, the switch SW12 is on, and the switch SW13 is off. In this case, the wiring resistance between the lithium-ion battery 12 and the electric load 15 is R11+ R12, and the wiring resistance between the lithium-ion battery 12 and the rotating electrical machine 16 is R11.
When the states of fig. 2(a) to (d) are compared, the wiring resistance between the lithium ion battery 12 and the electric load 15 (also referred to as the 1 st wiring resistance) and the wiring resistance between the lithium ion battery 12 and the rotating electric machine 16 (also referred to as the 2 nd wiring resistance) are different from each other in each state. Accordingly, the charge/discharge state of the lithium ion battery 12 can be changed by setting desired values for the 1 st and 2 nd wiring resistances while considering whether or not various conditions such as the charge and discharge state of the lithium ion battery 12 are to be positively performed. In addition to the above-described fig. 2(a) to (d), only one of the switches SW11 to SW13 may be turned on.
The present system has a control unit 30 constituting a battery control unit. The control unit 30 is configured mainly by a computer having a CPU, a memory, an input/output interface, and the like connected to each other, for example. The controller 30 switches on and off (opens and closes) the switches SW1, SW11 to SW 13. In this case, the control unit 30 monitors the running state of the vehicle and the storage states of the batteries 11 and 12, and controls the on/off of the switches SW1, SW11 to SW13 based on the monitored running state of the vehicle and the storage states of the batteries 11 and 12. Thereby, the lead storage battery 11 and the lithium ion storage battery 12 are selectively used, and the lead storage battery 11 and the lithium ion storage battery 12 are charged and discharged.
Here, charge/discharge control based on the stored power state of each of the storage batteries 11 and 12 will be briefly described.
The control unit 30 sequentially acquires, for example, the detected values of the terminal voltages of the lead storage battery 11 and the lithium ion storage battery 12 detected by the power supply sensor VS, and sequentially acquires the input/output currents (charge/discharge currents) of the lead storage battery 11 and the lithium ion storage battery 12 detected by the current detection unit CS.
Based on these obtained values, the control unit 30 calculates OCV (Open Circuit Voltage) and SOC (State Of Charge) Of the lead-acid battery 11 and the lithium-ion battery 12, and controls the amount Of Charge and the amount Of discharge Of the lead-acid battery 11 and the lithium-ion battery 12 so that the OCV and the SOC Of the lithium-ion battery 12 are kept within predetermined usage ranges. The OCV and the SOC correspond to storage state parameters indicating the storage state of each of the batteries 11 and 12. Temperature information of the batteries 11 and 12 is input to the control unit 30 from temperature sensors TS provided in the batteries 11 and 12.
The lithium-ion battery 12 of the two batteries 11 and 12 may be housed in a housing (housing case) not shown to constitute a battery unit, or the battery unit may be housed in the housing with the switches SW11 to SW13 and the controller 30 mounted on the same board.
An ECU (Electronic Control Unit) 40 is connected to the Control section 30. These control unit 30 and ECU40 are connected to each other via a communication Network such as CAN (Controller Area Network) so as to be communicable, and various data stored in control unit 30 and ECU40 CAN be shared with each other. The ECU40 is an electronic control device having a function of executing idling stop control of the vehicle. As is well known, the idling stop control is a control in which an engine is automatically stopped by satisfaction of a predetermined automatic stop condition and the engine is restarted by satisfaction of a predetermined restart condition in the automatic stop state. In the vehicle, the engine is started by the rotating electric machine 16 at the time of automatic restart of the idle reduction control.
Here, the SOC usage range of each battery 11, 12 will be described. Fig. 3 shows the correlation between the Open Circuit Voltage (OCV) and the state of charge (SOC) of the lead storage battery 11 and the lithium ion storage battery 12.
Fig. 3A shows a correlation between the open circuit voltage and the state of charge of the lead secondary battery (Pb)11, and the SOC usage range of the lead secondary battery 11 is W1. Fig. 3B shows a correlation between the open circuit voltage and the state of charge of the lithium ion battery (Li)12, and the SOC usage range of the lithium ion battery 12 is W2. Fig. 3B is also an enlarged view of the one-dot chain line portion (portion showing the SOC usage range W1 (Pb)) of fig. 3A, and the position on the horizontal axis of fig. 3B where the SOC of the lithium-ion battery 12 is 0% corresponds to the value of SOCa in the SOC usage range W1 (Pb). In both the figures, voltages Va and Vb have the same voltage value.
The horizontal axis in fig. 3A represents the SOC of the lead secondary battery 11, and the solid line a1 in the figure is a voltage characteristic line representing the relationship between the SOC of the lead secondary battery 11 and the open circuit voltage V0 (Pb). In proportion to the increase in the charge amount SOC, the opening voltage V0(Pb) also increases. The horizontal axis in fig. 3B represents the SOC of the lithium ion battery 12, and the solid line a2 in the figure is a voltage characteristic line representing the relationship between the SOC of the lithium ion battery 12 and the open circuit voltage V0 (Li). The charge amount increase SOC rises with the opening voltage V0(Li) also rising.
As shown in fig. 3B, the open voltage of the lead secondary battery 11 and the lithium ion secondary battery 12 differ in correlation with SOC, and it is determined that the open voltage of the lithium ion secondary battery 12 is made higher than the open voltage of the lead secondary battery 11 in the SOC use range W2 (Li). In the present embodiment, the lithium-ion battery 12 corresponds to a "priority battery", and the lead battery 11 corresponds to a "non-priority battery".
The batteries 11 and 12 may be overcharged or overdischarged to cause early deterioration. This limits the charge/discharge amount of the batteries 11 and 12 so that the SOC of each of the batteries 11 and 12 falls within a range (SOC use range) of a predetermined lower limit value and an upper limit value of the SOC that will not cause overcharge/discharge. In this case, the control unit 30 performs protection control for limiting the amount of charge in the batteries 11 and 12 to perform overcharge protection and limiting the amount of discharge from the lead-acid battery 11 and the lithium-ion battery 12 to perform overdischarge protection, in order to control the SOC of the lead-acid battery 11 within the SOC use range W1 and the SOC of the lithium-ion battery 12 within the SOC use range W2.
Next, the vehicle state and the states of the switches SW1, SW11 to SW13 will be described with reference to fig. 4.
Fig. 4(a) shows a state when the engine is automatically stopped by the idling stop control, (b) shows a state when the engine is restarted after being automatically stopped, (c) shows a state when the electric rotating machine 16 performs power assist, (d) shows a state where only the lithium ion battery 12 is charged when the electric rotating machine 16 performs deceleration regeneration, (e) shows a state where both the batteries 11 and 12 are charged when the electric rotating machine 16 performs deceleration regeneration, and (f) shows a state when the use of the lithium ion battery 12 is stopped. For convenience of explanation, the on/off states of the switches SW1, SW11 to SW13 are described in the order of SW1, SW11, SW12, and SW13 as "off, on", for example.
When the engine shown in fig. 4(a) is automatically stopped, the switches SW1, SW11 to SW13 are controlled to be in the states of "on, off, on" by the control unit 30. In this case, the lead storage battery 11 supplies power to the electric load 14. Further, power is supplied from the lithium ion battery 12 to the electric load 15.
At the time of engine restart shown in fig. 4(b), switches SW1, SW11 to SW13 are controlled to be in the states of "on, off, on" by control unit 30. That is, the switches SW1, SW11 to SW13 are controlled in the same state as in fig. 4 (a). In this case, the lead storage battery 11 supplies power to the electric load 14 and the rotating electric machine 16, and the rotating electric machine 16 starts the engine. Further, power is supplied from the lithium ion battery 12 to the electric load 15. At this time, since the power supply path to the rotating electrical machine 16 and the power supply path to the electric load 15 are disconnected by the switches SW11 and SW12 in the off state, no voltage variation occurs in the power supplied to the electric load 15 as the constant voltage request load.
At the time of the assist force shown in fig. 4(c), the switches SW1, SW11 to SW13 are controlled to be in the states of "off, on" by the control unit 30. In this case, the lead storage battery 11 supplies power to the electric load 14. Further, power is supplied from the lithium ion battery 12 to the electric load 15 and the rotating electric machine 16, respectively. The states of the switches SW1, SW11 to SW13 during the assisting operation of the rotary electric machine 16 will be described in detail later.
When the lithium-ion battery 12 is charged in the deceleration regeneration state shown in fig. 4(d), the switches SW1, SW11 to SW13 are controlled by the controller 30 to be in the states of "off, on". In this case, the electric power generated by the regenerative power generation of the rotating electrical machine 16 is supplied to the lithium-ion battery 12 and the electric load 15.
When the two batteries 11 and 12 are charged in the deceleration regeneration state shown in fig. 4(e), the switches SW1, SW11 to SW13 are controlled to the states of [ on, conducting ] by the controller 30. In this case, the electric power generated by the regenerative power generation of the rotating electrical machine 16 is supplied to the respective storage batteries 11 and 12, and the respective storage batteries 11 and 12 are appropriately charged. The generated power of the rotating electrical machine 16 is supplied to the electrical load 15.
When the use of the lithium-ion battery 12 shown in fig. 4(f) is stopped, the switches SW1, SW11 to SW13 are controlled to be in the states of [ on, off, on, off ] by the control unit 30. For example, when the calculation of the SOC of the lithium ion battery 12 is not completed after the start of the vehicle system, the charge and discharge of the lithium ion battery 12 are stopped when the SOC of the lithium ion battery 12 is low, at a low temperature, or at a fail-safe time. In this case, the lead storage battery 11 supplies power to the electric loads 14 and 15 and the rotating electric machine 16. The fail-safe determination of the lithium ion battery 12 may be performed by the control unit 30 based on, for example, changes in the terminal voltages of the lead batteries 11 and the lithium ion battery 12 detected by the voltage sensor VS during charge and discharge, the battery temperatures of the lead batteries 11 and the lithium ion battery 12, and the like.
In the present embodiment, when power is supplied to the rotating electric machine 16, that is, when power is discharged for high-output driving, as in the case of power assist, and when power is supplied to the other electric loads 14 and 15, the control unit 30 controls the on/off of the switches SW1, SW11 to SW13 based on the storage states and/or temperatures of the lead storage battery 11 and the lithium ion storage battery 12, and the details will be described later. Fig. 5 shows five discharge states in the case where the electric loads 14, 15 and the rotary electric machine 16 are the power supply targets.
In the present embodiment, the control unit 30 determines whether the lead storage battery 11 or the lithium ion storage battery 12 is to be discharged, for example, by comparing the storage states and/or temperatures of the lead storage battery 11 and the lithium ion storage battery 12 with corresponding predetermined values, and determines which route the lithium ion storage battery 12 is to discharge to which discharge target when the lithium ion storage battery 12 is to be discharged. In the present embodiment, the control unit 30 uses the OCV (or SOC) as the state-of-charge parameter of each battery 11, 12.
When the OCV of the lithium-ion battery 12 is larger than the OCV of the lead-acid battery 11, the control unit 30 controls the switches SW1, SW11 to SW13 to the state 1 of fig. 5(a), that is, to the state of [ on, conduction, on ]. In this case, the lithium-ion battery 12 has a sufficient margin, and power is supplied from the lithium-ion battery 12 to the electric loads 14 and 15 and the rotating electrical machine 16, respectively. At this time, the discharge from the lead storage battery 11 is stopped.
In short, the control unit 30 compares the storage states of the priority storage battery (Li) and the non-priority storage battery (Pb) by comparing the OCVs of the storage batteries 11 and 12, and sets a discharge state in which the priority storage battery supplies power to all the electrical loads 14 to 16 when the priority storage battery (Li) is in a high storage state.
When the OCV of the lithium ion battery 12 becomes lower than the OCV of the lead battery 11 as the electric power consumption decreases, the following states 2 to 5 are appropriately switched by the control unit 30 according to the amount of charge (the magnitude of OCV) of the lithium ion battery 12 and the temperature of the lithium ion battery 12. In short, when the non-priority battery (Pb) is in a high storage state in comparison of the OCV of each battery 11, 12, the control unit 30 appropriately discharges the non-priority battery and supplies power to each of the electrical loads 14 to 16.
In the 2 nd state of fig. 5(b), the switches SW1, SW11 to SW13 are controlled to be in the states of "off, on" by the controller 30. For example, when the state is changed from the 1 st state to the 2 nd state, in the 2 nd state, the lithium ion battery 12 starts discharging the electric load 15 and the rotating electric machine 16, and the lead battery 11 starts discharging. In this case, even if the OCV of the lithium ion battery 12 becomes smaller than the OCV of the lead battery 11, the lithium ion battery 12 is continuously discharged to a limited extent, and the lithium ion battery 12 is preferentially discharged to the electric load 15 and the rotating electrical machine 16, thereby reducing the temperature rise and the service stress of the lead battery 11.
In the 3 rd state of fig. 5(c), the switches SW1, SW11 to SW13 are controlled to be in the states of "on, off, on" by the controller 30. Thus, the discharge from the lithium-ion battery 12 to the rotary electric machine 16 is performed through the current-carrying path via the switches SW12 and SW 13. In this case, since the wiring resistance of the path from the lithium ion battery 12 to the rotating electrical machine 16 is increased as compared with the 1 st state and the 2 nd state, the power supply from the lithium ion battery 12 to the rotating electrical machine 16 is restricted, and the power supply from the lead battery 11 to the rotating electrical machine 16 is performed in accordance with the restriction.
In the 4 th state of fig. 5(d), the switches SW1, SW11 to SW13 are controlled to be in the states of on, off, on by the controller 30. In this case, the object to be discharged of the lithium ion battery 12 is limited to the electric load 15. Thereby, the discharge amount of the lithium ion battery 12 is suppressed, and the temperature rise due to the continued discharge is suppressed.
In the 5 th state of fig. 5(e), the switches SW1, SW11 to SW13 are controlled to be in the states of [ on, off, on, off ] by the controller 30. In this case, the discharge of the lithium ion battery 12 is stopped, and the electric loads 14 and 15 and the rotating electric machine 16 are supplied with power from the lead storage battery 11.
Here, when the respective states 2 to 5 are controlled according to the magnitude of the OCV of the lithium ion battery 12, the control unit 30 can switch the states in the order of the 2 nd state → the 3 rd state → the 4 th state → the 5 th state as the OCV decreases with the discharge of the lithium ion battery 12. Specifically, the threshold values TH1, TH2, and TH3 of the OCV of the lithium ion battery 12 are determined in advance (TH1 > TH2 > TH3), and the state is switched between the 2 nd state and the 5 TH state based on the result of comparison between the OCV of the lithium ion battery 12 and the threshold values by the control unit 30. The minimum threshold TH3 among the thresholds TH1 to TH3 may be determined with reference to the lower limit discharge voltage of the lithium ion battery 12, or may be determined on the high voltage side near and above the lower limit discharge voltage, for example.
Here, in the case of controlling the respective states 2 to 5 according to the temperature of the lithium ion battery 12, the control unit 30 may switch the states in the order of 2 nd state → 3 rd state → 4 th state → 5 th state as the discharge of the lithium ion battery 12 is accompanied by an increase in the battery temperature. Specifically, the threshold values TH11, TH12, and TH13 of the temperature of the lithium ion battery 12 are determined in advance (TH11 > TH12 > TH13), and the state is switched between the 2 nd state and the 5 TH state based on the result of comparison between the battery temperature of the lithium ion battery 12 and the magnitude of each threshold value by the control unit 30. The threshold TH13 on the highest temperature side among the thresholds TH11 to TH13 may be determined on the low temperature side lower than the upper limit allowable temperature of the lithium ion battery 12.
The control unit 30 may be configured to control the states 2 nd to 5 th according to the OCV and the temperature of the lithium ion battery 12. In this case, the state switching between the 2 nd state to the 5 th state may be performed by the control unit in consideration of the decrease in OCV and the increase in temperature of the lithium-ion battery 12 accompanying the discharge thereof.
According to the above-described 1 st to 5 th states, when the respective electric loads are discharged from the respective storage batteries 11 and 12, the lithium ion storage battery 12 of the two storage batteries 11 and 12 is preferentially used and the electric power is appropriately supplied to the respective electric loads. When the power supply load to each electrical load is switched by each battery 11, 12, stable power supply is performed to each electrical load without lowering the drive voltage. Further, since the situation (scene) in which the discharge is performed in the batteries 11 and 12 is limited, the pressure generated with the use of the batteries 11 and 12 can be reduced.
When the control unit 30 switches between the 1 st to 5 th states as described above, the discharge target to be discharged from the lithium ion battery 12 gradually decreases while the SOC of the lithium ion battery 12 gradually decreases. In this case, the discharge current of the lithium-ion battery 12 decreases stepwise every time the discharge target decreases, and the battery voltage (OCV) increases at the time of state switching. Therefore, the life of the lithium-ion battery 12 can be extended.
That is, as shown in fig. 6, a voltage drop occurs in the battery voltage (OCV) of the lithium ion battery 12 with the passage of time in the discharged state of the lithium ion battery 12, and a voltage rise occurs in a stepwise manner at timings t1, t2 when the state is switched. In this case, by separating the load from the lithium ion battery 12, the battery voltage of the lithium ion battery 12 increases compared to before the separation. This enables the lithium-ion battery 12 to be fully used up to the usable lower limit voltage.
When power is supplied from the rotating electric machine 16, that is, during charging, the switches SW1, SW11 to SW13 are appropriately switched by the control unit 30. In this case, the control unit 30 compares the storage states and temperatures of the lead storage battery 11 and the lithium ion storage battery 12 to determine which storage battery is to be charged, and determines via which route to charge each storage battery 11, 12. For example, the controller 30 controls the on/off of the switches SW1, SW11 to SW13 so that the charging current is more likely to flow into the lithium ion battery 12 as the amount of power stored in the lithium ion battery 12 is smaller. The controller 30 controls the on/off of the switches SW1, SW11 to SW13 so that the charging current is less likely to flow into the lithium ion battery 12 as the temperature of the lithium ion battery 12 is higher.
Next, a process procedure of the switching control (switching control flow) performed by the control unit 30 will be described with reference to the flowchart of fig. 7. This flow is executed at a predetermined cycle in the control unit 30. Here, the control of switching the switches SW1, SW11 to SW13 based on the amount of stored electricity in the lithium ion battery 12 when the rotating electrical machine 16 is driven will be described.
In fig. 7, in step S11, the control unit 30 determines whether or not there is a request for driving the rotating electric machine 16. When there is a drive request, the switch changeover control flow proceeds to step S12. In step S12, the control unit 30 determines whether or not the OCV (Li _ OCV in fig. 7) of the lithium-ion battery 12 is greater than the OCV (Pb _ OCV in fig. 7) of the lead battery 11.
If the result of the determination at step S12 is yes, the switch changeover control flow proceeds to step S13, and the controller 30 controls the switches SW1, SW11 to SW13 in the 1 st state. That is, the controller 30 sets the switches SW1, SW11 to SW13 to "on, conducting".
If no in step S12, the switch switching control flow proceeds to step S14, and controller 30 switches the state based on the determination results in steps S14 to S16. Specifically, the control unit 30 determines whether the OCV of the lithium ion battery 12 is equal to or greater than a threshold TH1 in step S14, determines whether the OCV of the lithium ion battery 12 is equal to or greater than a threshold TH2 in step S15, and determines whether the OCV of the lithium ion battery 12 is equal to or greater than a threshold TH3 in step S16.
If the determination of step S14 is yes, control unit 30 controls switches SW1 and SW11 to SW13 to the 2 nd state, that is, the state of [ off, on ] in step S17.
If no in step S14 and yes in step S15, in step S18, controller 30 controls switches SW1, SW11 to SW13 to the 3 rd state, that is, the state of [ on, off, on ].
If step S14 and step S15 are no and step S16 is yes, control unit 30 controls switches SW1 and SW11 to SW13 to the 4 th state, that is, to the state of [ on, off, on ] in step S19.
Next, if no in step S16, in step S20, controller 30 controls switches SW1, SW11 to SW13 to the 5 th state, that is, the state of [ on, off, on, off ].
The processing in fig. 7 may be configured as follows: even when the OCV of the lithium-ion battery 12 is larger than the OCV of the lead-acid battery 11 (yes in step S12), if the OCV of the lithium-ion battery 12 is equal to or smaller than a predetermined threshold value or the battery temperature of the lithium-ion battery 12 is equal to or larger than a predetermined threshold value, the control unit 30 controls the switches SW1, SW11 to SW13 in any of the 2 nd to 4 th states.
Instead of the configuration in which the control unit 30 switches the switches SW1, SW11 to SW13 on condition that the request for driving the rotating electric machine 16 is made, the configuration may be such that the switches are switched regardless of the presence or absence of the request for driving the rotating electric machine 16.
The power supply system according to the present embodiment described in detail above can obtain excellent effects described below.
That is, in the power supply system according to the present embodiment, the 1 st branch path L11 and the 2 nd branch path L12 are provided so as to branch between the 1 st point N1 connected to the rotary electric machine 16 and the 2 nd point N2 connected to the lithium ion battery 12, the switch SW11 (the 1 st switch) is provided on the 1 st branch path L11, and the switches SW12 and SW13 (the 2 nd switch and the 3 rd switch) are provided in series on the 2 nd branch path L12. With this configuration, the lithium-ion battery 12 and the rotary electric machine 16 can be connected by selectively using the two branch paths L11, L12. In this case, by individually controlling the on/off states of the switches SW11 to SW13, the wiring resistances between the lithium-ion battery 12 and the rotating electrical machine 16 can be made different from each other by the resistances (on resistances) of the corresponding switches, and the magnitude of the current flowing through the lithium-ion battery 12 can be adjusted. By adjusting the magnitude of the current flowing through the lithium ion battery 12, the current distribution between the lead battery 11 and the lithium ion battery 12 can be changed. Accordingly, the batteries 11 and 12 can be used while taking into consideration differences in properties and states. As a result, the respective batteries 11 and 12 can be appropriately charged and discharged.
In the configuration in which the closed circuit including the switches SW11 to SW13 is formed in the power supply system according to the present embodiment, even if an open abnormality (open abnormality) occurs in any one of the switches SW11 to SW13, the remaining two switches are turned on, whereby the current can be continuously supplied between the lithium-ion battery 12 and the rotating electrical machine 16.
In the power supply system according to the present embodiment, in the configuration in which the electric load 15 is connected to the 3 rd point N3 on the 2 nd branch path L12, the on/off states of the switches SW11 to SW13 are controlled by the controller 30, whereby the wiring resistances between the lithium ion battery 12 and the electric load 15 can be made different from each other. As a result, the magnitude of the discharge current discharged from the lithium ion battery 12 to the electrical load 15, that is, the discharge load of the lithium ion battery 12 can be adjusted. This can suppress energy loss during driving of the electric load 15.
In the power supply system according to the present embodiment, the control unit 30 controls all of the switches SW11 to SW13 of the wiring resistance switching unit 20 to be on in a state where the switch SW1 (the 4 th switch) is turned off. In this case, by turning off the switch SW1, the lithium ion battery 12 among the batteries 11 and 12 is preferentially used to discharge the electric load 15 and the rotating electric machine 16. By turning on all of the switches SW11 to SW13 of the wiring resistance switching unit 20, the lithium ion battery 12 can discharge electricity to the electric load 15 and the rotating electric machine 16 while the wiring resistance is reduced.
In the power supply system according to the present embodiment, when the rotating electrical machine 16 and the electric load 15 are both in the driving state by the power supply, the switches SW1, SW11 to SW13 are controlled to the states of [ on, off, on ] by the control unit 30. In this configuration, the power supply path to the rotary electric machine 16 and the power supply path to the electric load 15 are disconnected by the switches SW11, SW12 in the off state. Therefore, in a state where the rotating electric machine 16 and the electric load 15 are driven together, the influence of the driving of the rotating electric machine 16 on the voltage variation of the battery is not exerted on the driving of the electric load 15.
When the electric load 15 is a constant-voltage-required load, the power supply voltage fluctuates as the rotating electric machine 16 is driven, and thus the operation of the electric load 15 may become unstable. In this connection, by disconnecting the power supply path to the rotating electrical machine 16 and the power supply path to the electrical load 15 as described above, a stable operation of the constant voltage-requiring load can be achieved.
In the power supply system according to the present embodiment, the control unit 30 is configured to switch between: all of the switches SW11 to SW13 of the wiring resistance switching unit 20 are turned on; and bringing at least one switch into an open state. Therefore, the resistance values (the resistance values between N1 and N2, the resistance values between N1 and N3, and the resistance values between N2 and N3) between the points N1 and N3 can be changed. This can increase or decrease the wiring resistance between the lithium ion battery 12 and the rotating electrical machine 16 or between the lithium ion battery 12 and the electrical load 15, and can change the state of charge and discharge in the lithium ion battery 12.
In the power supply system according to the present embodiment, the on/off of each of the switches SW11 to SW13 of the wiring resistance switching unit 20 is controlled by the control unit 30 in a state where the switch SW1 is turned on. With this configuration, for example, when the lead storage battery 11 and the lithium ion storage battery 12 are electrically connected to the rotating electric machine 16, the charge/discharge sharing ratio of each of the storage batteries 11 and 12 can be adjusted. This enables the pressure for use of each of the batteries 11 and 12 to be appropriately adjusted.
The power supply system according to the present embodiment is configured to control on/off of the switches SW11 to SW13 of the wiring resistance switching unit 20 based on a parameter including at least one of the storage state and the temperature of the lead storage battery 11 and the lithium ion storage battery 12. For example, when a charge/discharge current flows through the lithium ion battery 12, a reduction in the amount of stored electricity and an increase in the battery temperature due to the discharge occur. In this case, by controlling the on/off states of the switches SW1, SW11 to SW12 by the control unit 30 based on the storage states and temperatures of the storage batteries 11 and 12, it is possible to suppress a decrease in the excessive storage amount and a temperature increase of the storage batteries 11 and 12, and further, it is possible to appropriately perform charging and discharging of the storage batteries 11 and 12.
The power supply system according to the present embodiment is configured such that when it is determined that an abnormality has occurred in the lithium-ion battery 12, the switches SW1, SW11 to SW13 are controlled to be in the states of "on, off, on, and off" by the control unit 30. With this configuration, when the lithium-ion battery 12 is abnormal, the lithium-ion battery 12 is separated from the rotating electric machine 16 and the electric load 15, and the lead battery 11 supplies power to the rotating electric machine 16 and the electric load 15. Therefore, even after the abnormality of the lithium-ion battery 12 occurs, the rotating electric machine 16 and the electric load 15 can be continuously used.
(embodiment 2)
Next, the power supply system according to embodiment 2 will be described focusing on differences from the power supply system according to embodiment 1. The circuit configuration of the power supply system according to the present embodiment is shown in fig. 8.
In the circuit configuration of fig. 8, similarly to the circuit configuration of fig. 1, a1 st branch path L11 and a2 nd branch path L12 are provided between a1 st point N1 connected to the rotating electric machine 16 and a2 nd point N2 connected to the lithium ion battery 12. Further, a switch SW11 is provided in the 1 st branch path L11, and a switch SW12 and a switch SW13 are provided in series in the 2 nd branch path L12. This constitutes the wiring resistance switching unit 20. Next, the 2 nd branch path L12 connects the electric load 15 to the 3 rd point between the switches SW12 and SW13, and connects the lead secondary battery 11 and the electric load 14 via the switch SW 1.
In this case, the lead storage battery 11 is connected to the 1 st point N1 in the circuit configuration of fig. 1, whereas the lead storage battery 11 is connected to the 3 rd point N3 in the circuit configuration of fig. 8, which is different from each other. In the present embodiment, a part of the 2 nd branch path L12 (between N1 and N3) also serves as an electrical path L1 connecting the lead acid battery 11 and the rotating electric machine 16.
Similarly, in the circuit configuration of fig. 8, the wiring resistance between the lithium-ion battery 12 and the electric load 15 and the wiring resistance between the lithium-ion battery 12 and the rotating electrical machine 16 can be changed by turning on or off any of the switches SW11 to SW 13.
Next, the vehicle state and the states of the switches SW1, SW11 to SW13 will be described with reference to fig. 9. In the present embodiment, at the time of the engine restart of the idle reduction control, the lithium ion battery 12 supplies power to the rotating electric machine 16 to start the engine.
Fig. 9(a) shows a state when the engine is automatically stopped by the idling stop control, (b) shows a state when the engine is restarted after being automatically stopped, (c) shows a state when the rotary electric machine 16 performs power assist, (d) shows a state where only the lithium ion battery 12 is charged when the rotary electric machine 16 performs deceleration regeneration, (e) shows a state where both the batteries 11 and 12 are charged when the rotary electric machine 16 performs deceleration regeneration, and (f) shows a state when the use of the lithium ion battery 12 is stopped.
When the engine shown in fig. 9(a) is automatically stopped, the switches SW1, SW11 to SW13 are controlled to be in the states of "on, off, and off" by the control unit 30. In this case, power is supplied from the lead storage battery 11 to the electric loads 14 and 15.
At the time of engine restart shown in fig. 9(b), switches SW1, SW11 to SW13 are controlled to be in the states of "on, off" by control unit 30. That is, the switches SW1, SW11 to SW13 are controlled in the same state as in fig. 9 (a). In this case, in a state where the lead storage battery 11 supplies power to the electric loads 14 and 15, the lithium ion storage battery 12 supplies power to the rotating electric machine 16, and the rotating electric machine 16 starts the engine. At this time, since the power supply path to the rotating electrical machine 16 and the power supply path to the electric load 15 are disconnected by the switches SW12 and SW13 in the off state, no voltage variation occurs in the power supplied to the electric load 15 as the constant voltage request load.
At the time of the assist force shown in fig. 9(c), the switches SW1, SW11 to SW13 are controlled to be in the states of "off, on" by the control unit 30. In this case, the lead storage battery 11 supplies power to the electric load 14. Further, power is supplied from the lithium ion battery 12 to the electric load 15 and the rotating electric machine 16, respectively. The states of the switches SW1, SW11 to SW13 during the assisting operation of the rotary electric machine 16 will be described in detail later.
When the lithium-ion battery 12 is charged in the deceleration regeneration state shown in fig. 9(d), the switches SW1, SW11 to SW13 are controlled by the controller 30 to be in the states of "off, on". In this case, the electric load 14 is supplied with power from the lead storage battery 11, and the electric power generated by the regenerative power generation of the rotating electrical machine 16 is supplied to the lithium-ion storage battery 12 and the electric load 15.
When the two batteries 11 and 12 are charged in the deceleration regeneration state shown in fig. 9(e), the switches SW1, SW11 to SW13 are controlled to the states of [ on, conducting ] by the controller 30. In this case, the electric power generated by the regenerative power generation of the rotating electrical machine 16 is supplied to the respective storage batteries 11 and 12, and the respective storage batteries 11 and 12 are appropriately charged. The generated power of the rotating electrical machine 16 is supplied to the electrical loads 14, 15.
When the use of the lithium-ion battery 12 shown in fig. 9(f) is stopped, the switches SW1, SW11 to SW13 are controlled to be in the states of [ on, off, on, off ] by the control unit 30. In this case, the lead storage battery 11 supplies power to the electric loads 14 and 15 and the rotating electric machine 16.
When power is supplied to the rotating electrical machine 16, i.e., during discharge for high-power drive, as in the case of power assist, and when power is supplied to the other electrical loads 14 and 15 by the rotating electrical machine 16, the control unit 30 controls the on/off of the switches SW1, SW11 to SW13 based on the storage states and/or temperatures of the lead storage battery 11 and the lithium ion storage battery 12. Fig. 10 shows five discharge states in the case where the electric loads 14, 15 and the rotary electric machine 16 are power-supplied objects.
When the OCV of the lithium-ion battery 12 is larger than the OCV of the lead battery 11, the control unit 30 controls the switches SW1, SW11 to SW13 to the state 1 of fig. 10(a), i.e., [ on, conductive, on, conductive ]. In this case, the lithium-ion battery 12 has a sufficient margin, and power is supplied from the lithium-ion battery 12 to the electric loads 14 and 15 and the rotating electrical machine 16, respectively. At this time, the discharge from the lead storage battery 11 is stopped.
In short, the control unit 30 compares the storage states of the priority storage battery (Li) and the non-priority storage battery (Pb) by comparing the OCVs of the storage batteries 11 and 12, and sets a discharge state in which the priority storage battery supplies power to all the electrical loads 14 to 16 when the priority storage battery (Li) is in a high storage state.
When the OCV of the lithium ion battery 12 decreases and the power consumption becomes smaller than the OCV of the lead battery 11, the following states 2 to 5 are appropriately switched by the control unit 30 depending on the amount of power stored in the lithium ion battery 12 (the magnitude of the OCV) and the temperature of the lithium ion battery 12. In short, when the non-priority battery (Pb) is in a high storage state in comparison of the OCV of each battery 11, 12, the control unit 30 appropriately discharges the non-priority battery and supplies power to each of the electrical loads 14 to 16.
In the 2 nd state of fig. 10(b), the switches SW1, SW11 to SW13 are controlled to be in the states of "off, on" by the controller 30. For example, when the state is changed from the 1 st state to the 2 nd state, in the 2 nd state, the lead storage battery 11 starts discharging in addition to the lithium ion storage battery 12 to supply power to the electric load 14. In this case, even if the OCV of the lithium ion battery 12 becomes smaller than the OCV of the lead battery 11, the lithium ion battery 12 can continue to be discharged to a limited extent, that is, the lithium ion battery 12 can preferentially discharge to the electric loads 15 and 16, and the temperature rise and the service pressure of the lead battery 11 can be reduced.
In the 3 rd state of fig. 10(c), the switches SW1, SW11 to SW13 are controlled to be in the states of "on, off, on" by the controller 30. Thereby, the lead storage battery 11 discharges the electric loads 14 and 15 and the rotating electric machine 16, and the lithium ion storage battery 12 also discharges the electric load 15 and the rotating electric machine 16. At this time, the electric discharge to the rotating electric machine 16 is performed through the current-carrying path via the switches SW12 and SW 13. In this case, since the wiring resistance of the path from the lithium ion battery 12 to the rotating electrical machine 16 is increased as compared with the 1 st state and the 2 nd state, the power supply from the lithium ion battery 12 to the rotating electrical machine 16 is restricted, and the power supply from the lead battery 11 to the rotating electrical machine 16 is performed in accordance with the restriction.
In the 4 th state of fig. 10(d), the switches SW1, SW11 to SW13 are controlled to be in the states of on, off, and off by the controller 30. In this case, the electric loads 14 and 15 are discharged by the lead storage battery 11, and the discharging target of the lithium ion storage battery 12 is limited to only the rotating electrical machine 16. Thereby, the discharge amount of the lithium ion battery 12 is suppressed, and the temperature rise due to the continued discharge is suppressed.
In the 5 th state of fig. 10(e), the switches SW1, SW11 to SW13 are controlled to be in the states of [ on, off, on, off ] by the controller 30. In this case, the discharge of the lithium ion battery 12 is stopped, and the electric loads 14 and 15 and the rotating electric machine 16 are supplied with power from the lead storage battery 11.
Here, when the respective states 2 to 5 are controlled according to the magnitude of the OCV of the lithium ion battery 12, the control unit 30 can switch the states in the order of the 2 nd state → the 3 rd state → the 4 th state → the 5 th state as the OCV becomes smaller with the discharge of the lithium ion battery 12 (the 3 rd state and the 4 th state may be reversed). Specifically, as in embodiment 1, the threshold values TH1, TH2, and TH3 of the OCV of the lithium-ion battery 12 are determined in advance (TH1 > TH2 > TH3), and the state is switched between the 2 nd state and the 5 TH state based on the result of comparison between the OCV of the lithium-ion battery 12 and the threshold values by the control unit 30.
In the case where the states 2 to 5 are controlled in accordance with the temperature of the lithium ion battery 12, the control unit 30 may switch the states 2 → 3, 4, and 5 in this order as the battery temperature increases with the discharge of the lithium ion battery 12 (the states 3 and 4 may be reversed). Specifically, as in embodiment 1, the threshold values TH11, TH12, and TH13(TH11 < TH12 < TH13) of the temperature of the lithium-ion battery 12 are determined in advance, and the state is switched between the 2 nd state and the 5 TH state based on the result of comparison between the battery temperature of the lithium-ion battery 12 and the magnitude of each threshold value by the controller 30.
The control unit 30 may be configured to control the states 2 nd to 5 th according to the OCV and the temperature of the lithium ion battery 12. In this case, the state switching between the 2 nd state to the 5 th state may be performed by the control unit 30 in consideration of the decrease in OCV and the increase in temperature of the lithium-ion battery 12 accompanying the discharge thereof.
According to the above-described 1 st to 5 th states, when the respective batteries 11 and 12 discharge the respective electric loads, the lithium ion battery 12 of the two batteries 11 and 12 is preferentially used to appropriately supply power to the respective electric loads at the same time. When the load of power supply to each electric load is switched by each battery 11, 12, stable power supply is performed to each electric load without lowering the driving voltage. Further, since the situation (scene) in which the batteries 11 and 12 are discharged is limited, the pressure generated during the use of the batteries 11 and 12 can be reduced.
In embodiment 2 described in detail above, as in embodiment 1, the excellent effects of being able to appropriately perform charging and discharging of the batteries 11 and 12 can be obtained.
(other embodiments)
The above embodiment may be modified as described below.
The control unit 30 may be configured to monitor the power storage state of each of the storage batteries 11 and 12 based on the record of the charge and discharge in each of the storage batteries 11 and 12. In this case, the control unit 30 grasps the charge record based on at least one of the number of times and the time of charging the storage batteries 11 and 12, and grasps the discharge record based on at least one of the number of times and the time of discharging the storage batteries 11 and 12. When the lithium ion battery 12 is charged, the controller 30 controls the on/off of the switches SW1, SW11 to SW13 based on the charge record of the lithium ion battery 12. When the lithium ion battery 12 is discharged, the controller 30 controls the on/off of the switches SW1, SW11 to SW13 based on the charge record of the lithium ion battery 12. At this time, the controller 30 controls the on/off of the switches SW1, SW11 to SW13 so that the discharge from the lithium ion battery 12 is performed as the discharge amount of the lithium ion battery 12 determined based on the discharge record increases, for example.
The controller 30 may be configured to control the on/off of the switches SW1, SW11 to SW13 based on the operating state of the engine and the vehicle and the surrounding environment. For example, controller 30 controls on/off of switches SW1, SW11 to SW13 based on the engine speed, the engine load, the engine temperature (coolant temperature), the vehicle speed, the outside air temperature, and the like.
In the above embodiment, the lithium ion battery 12 is used as the priority battery and the lead battery 11 is used as the non-priority battery, but the opposite is also possible.
The rotating electrical machine 16 may be a power generation device such as an alternator, for example, as long as it has at least a power generation function. The electric load 15 may not include the constant voltage requiring load.
The power supply system is not limited to the configuration including the lead storage battery 11 as the 1 st storage battery and the lithium ion storage battery 12 as the 2 nd storage battery. For example, another storage battery such as a nickel metal hydride battery may be used as the 2 nd storage battery. Both the 1 st battery and the 2 nd battery may be a lead battery or a lithium ion battery.
The present invention is not limited to the in-vehicle power supply device, and may be applied to a power supply device other than the in-vehicle power supply device.
Further, the present application claims priority on the basis of japanese patent application 2015-205326, and the disclosure of the japanese patent application on which the priority is based is incorporated into the present application as a reference.
Description of the reference symbols
11 lead storage batteries (1 st storage battery), 12 lithium ion storage batteries (2 nd storage battery), 16 rotating electrical machines, SW11 1 st switch, SW12 2 nd switch, SW13 3 rd switch, SW 14 th switch and 30 control parts.

Claims (9)

1. A kind of power supply device is disclosed,
a power supply system to which the power supply device is applied is provided with: a power supply device comprising a1 st battery (11) and a2 nd battery (12) connected in parallel to a rotating electric machine (16) having at least a power generation function, the power supply device being characterized by comprising:
a1 st branch path (L11) and a2 nd branch path (L12), the 1 st branch path (L11) and the 2 nd branch path (L12) being branched between a1 st point (N1) connected to the rotating electrical machine and a2 nd point (N2) connected to the 2 nd storage battery;
a1 st switch (SW11), the 1 st switch (SW11) being provided on the 1 st branch path;
a2 nd switch (SW12) and a 3 rd switch (SW13), the 2 nd switch (SW12) and the 3 rd switch (SW13) being arranged in series in the 2 nd branch path;
a 4 th switch (SW1) provided in a current-carrying path between the 1 st battery (11) and either the 1 st point (N1) or the 3 rd point (N3), the 4 th switch (SW1) being different from the current-carrying paths of the 1 st branch path (L11) and the 2 nd branch path (L12); and
and a control unit (30), wherein the control unit (30) controls the opening and closing of each of the 1 st to 4 th switches.
2. The power supply device according to claim 1,
an electrical load (15) is connected to the 3 rd point.
3. The power supply device according to claim 2,
the control unit closes each of the 1 st to 3 rd switches in a state where the 4 th switch is opened.
4. The power supply device according to claim 2 or 3,
when the rotating electric machine and the electric load are driven by supplying power together, the control unit closes the 4 th switch, opens two switches connected to one of the 1 st point and the 3 rd point on one end side of the 4 th switch among the 1 st switch to the 3 rd switch, and closes the remaining one switch.
5. The power supply device according to claim 4,
the electric load is a stable electric load required to keep the voltage of the power supply constant or to vary at least within a predetermined range.
6. The power supply device according to any one of claims 1 to 3,
the control unit switches the following two states for the 1 st to 3 rd switches: that is, a state in which all switches are closed; and a state in which at least one switch is opened.
7. The power supply device according to any one of claims 1 to 3,
the control unit controls the 1 st to 3 rd switches to be opened and closed individually in a state where the 4 th switch is closed.
8. The power supply device according to any one of claims 1 to 3,
the control unit controls the 1 st to 4 th switches to be opened and closed based on a parameter including at least one of a state of charge and a temperature of each of the 1 st and 2 nd batteries.
9. The power supply device according to any one of claims 1 to 3,
the control unit (30) is configured to determine whether or not there is an abnormality in the 2 nd storage battery,
when it is determined that the 2 nd battery is abnormal, the control unit closes the 4 th switch, opens two switches connected to the 2 nd point among the 1 st to 3 rd switches, and closes the remaining one switch.
CN201680060735.0A 2015-10-19 2016-10-17 Power supply device Active CN108352719B (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2015-205326 2015-10-19
JP2015205326A JP6406205B2 (en) 2015-10-19 2015-10-19 Power supply
PCT/JP2016/080745 WO2017069096A1 (en) 2015-10-19 2016-10-17 Power supply device

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JP3417720B2 (en) * 1995-04-24 2003-06-16 株式会社デンソー Power generator for vehicles
JP2008190323A (en) * 2005-05-13 2008-08-21 Matsushita Electric Ind Co Ltd Engine starting system
WO2011121974A1 (en) * 2010-03-29 2011-10-06 パナソニック株式会社 Power supply device for vehicle
CN202633993U (en) * 2012-05-10 2012-12-26 杨湘武 Automatic battery pack charging-discharging management device
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JP2017079503A (en) 2017-04-27

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