JP6465146B2 - In-vehicle battery charge control system - Google Patents

Description

  In the present invention, for example, in a state where an in-vehicle battery of a vehicle such as an electric vehicle and an external power supply device for charging the in-vehicle battery are connected, the battery temperature of the in-vehicle battery in a low temperature environment is in an appropriate temperature range. The present invention relates to a charging control system for an on-vehicle battery that is maintained.

  In vehicles such as plug-in hybrid vehicles and electric vehicles that use the output of the drive motor as the driving force, lithium-ion secondary batteries with higher output and better charging efficiency than conventional lead-acid batteries are used for driving. It is used as an in-vehicle battery for supplying electric power to the motor.

  Such an in-vehicle battery of the vehicle cannot be sufficiently charged only by the electric power obtained by converting the regenerative energy, and is therefore charged by the external electric power supplied from an external electric power supply device provided in a vehicle storage place such as a home. At this time, since it takes a certain amount of time to charge the in-vehicle battery as compared with the case where fuel such as gasoline is supplied, the in-vehicle battery is often charged in a time zone where the vehicle is not used for a long time such as at night.

  However, the lithium ion secondary battery is characterized in that the output characteristics are extremely lowered when the battery temperature is low, for example, the battery temperature is 0 ° C. or lower. For this reason, when the vehicle in which the in-vehicle battery is completely charged is left in a low temperature environment for a long time, the battery temperature of the in-vehicle battery is lowered, and the startability as the vehicle is lowered.

Therefore, a technique for suppressing a decrease in battery temperature in a state where the on-vehicle battery of the vehicle and the external power supply device are connected has been proposed.
For example, in Patent Document 1, when an in-vehicle battery and an external power supply device are connected in a low temperature environment, by repeating charge and discharge of the in-vehicle battery within a predetermined charging rate range, self-heating is promoted and the battery temperature is increased. Is suppressed.

  By the way, in Patent Document 1, the number of vehicles that can be connected to one external power supply device is one. For this reason, when there are a plurality of vehicles that can be connected to one external power supply device, in Patent Document 1, a plurality of in-vehicle batteries are charged by simultaneously charging a plurality of connected in-vehicle batteries. There was a risk that the total amount of power supplied to would exceed the contracted power capacity.

  Thus, when a plurality of vehicles are connected to the external power supply device, a new problem of how to perform charge / discharge control in order to achieve both charging of the in-vehicle battery and maintenance of the battery temperature. Has occurred.

Japanese Patent No. 545701

  In view of the above-described problems, the present invention provides an in-vehicle battery capable of both charging an in-vehicle battery and maintaining the battery temperature even when a plurality of vehicles are connected to an external power supply device in a low temperature environment. An object of the present invention is to provide a charging control system.

  The present invention includes an in-vehicle battery mounted in a vehicle, an external power supply device that is electrically connected to the in-vehicle battery and supplies external power to the in-vehicle battery from the outside of the vehicle, and charging of the in-vehicle battery. Charge / discharge control means for controlling discharge within a predetermined charging rate range of the in-vehicle battery and controlling discharge of the in-vehicle battery so as to maintain a battery temperature of the in-vehicle battery within a predetermined temperature range A charge control system for an in-vehicle battery, wherein the charge / discharge control means performs charge control for charging the in-vehicle battery, standby control for waiting for charge / discharge of the in-vehicle battery, and discharge control for discharging the in-vehicle battery in this order. The charge control, the standby control, and the discharge control are performed as one charge / discharge cycle, and the charge / discharge cycle is repeated. And the external power supply device is configured such that a plurality of the vehicles can be connected, and when the plurality of vehicles are connected to the external power supply device, the charge / discharge cycle between the plurality of vehicles. Timing control means for controlling the start timing of the vehicle, and the timing control means is configured to start the charge control when the charge / discharge cycle in another vehicle is the standby control or / and the discharge control. It is the structure which controls the start timing of the charging / discharging cycle between the said vehicles.

The in-vehicle battery is an in-vehicle battery for supplying power to a drive motor in an electric vehicle, for example, and can be a lithium ion secondary battery.
The range of the predetermined charging rate is a range of charging rate at which charging is completed, and can be set to a range of 80% to 100%, for example.
The predetermined temperature range is a battery temperature range in which desired output characteristics of the in-vehicle battery can be obtained, and can be, for example, a normal temperature range.
The charge / discharge control means can be a control means provided in a vehicle or a vehicle-mounted battery, a control means provided in an external power supply device, or a control means based on cooperation thereof.

  According to the present invention, the in-vehicle battery charging control system achieves both charging of the in-vehicle battery and maintenance of the battery temperature even when a plurality of vehicles are connected to the external power supply device in a low temperature environment. be able to.

  Specifically, the charge control, standby control, and discharge control are set as one charge / discharge cycle, and the charge / discharge cycle is repeated. The natural cooling of the in-vehicle battery by the control and the temperature maintenance of the in-vehicle battery by the discharge control can be repeated.

  At this time, since discharge control is performed so as to maintain the battery temperature, the in-vehicle battery charge control system can suppress the discharge amount as compared with the discharge amount for raising the temperature of the in-vehicle battery. For this reason, the in-vehicle battery charging control system can maintain the battery temperature while suppressing a decrease in the charging rate.

  When a plurality of vehicles are connected to the external power supply device, the charge / discharge cycle between the vehicles is started so that the charge control is started when the charge / discharge cycle in another vehicle is standby control or / and discharge control. By controlling the start timing, the in-vehicle battery charging control system can prevent charging control from being performed simultaneously among a plurality of vehicles. For this reason, the charge control system for in-vehicle batteries can prevent the total amount of power supplied to the plurality of in-vehicle batteries from exceeding the contract power capacity.

  Furthermore, by providing standby control between the charge control and the discharge control, the charge control system for the in-vehicle battery can be applied to the in-vehicle battery as compared with the case where the charge control and the discharge control are performed as one charge / discharge cycle. A long time for stopping the power supply can be secured. For this reason, even if it is a case where a some vehicle is connected to an external electric power supply apparatus, the charging control system of a vehicle-mounted battery can ensure the charging time per vehicle stably.

  In addition, when the number of vehicles connected to the external power supply device is large, the in-vehicle battery charge control system, for example, adjusts the control time of standby control to charge all connected in-vehicle batteries. Can be easily. For this reason, the in-vehicle battery charging control system can flexibly cope with increase / decrease in the number of vehicles connected to the external power supply device.

  Therefore, the in-vehicle battery charging control system can achieve both charging of the in-vehicle battery and maintenance of the battery temperature even when a plurality of vehicles are connected to the external power supply device in a low temperature environment. it can.

As an aspect of the present invention, an outside air temperature detecting unit that detects an outside air temperature is provided, and the timing control unit controls the control time of the standby control in the one charge / discharge cycle based on the detected outside air temperature. It is a configuration.
According to the present invention, the in-vehicle battery charging control system can prevent unnecessary charging and discharging and maintain the battery temperature more efficiently.

Specifically, the battery temperature of the in-vehicle battery decreases with time due to heat radiation to the atmosphere in a state where charging and discharging are not performed. For this reason, if the control time of standby control becomes long under a low temperature environment, the battery temperature of the in-vehicle battery may fall below a predetermined temperature range.
Furthermore, in this case, since it is necessary to raise the in-vehicle battery to a predetermined temperature range when the discharge control is started, there is a possibility that the charging rate falls below the predetermined charging rate due to excessive discharge.

Therefore, by controlling the control time of standby control based on the outside air temperature, the in-vehicle battery charge control system performs discharge control in a low temperature environment before the battery temperature of the in-vehicle battery falls below a predetermined temperature range. Can start.
Therefore, the on-board battery charging control system controls the standby control time based on the outside air temperature, thereby preventing unnecessary discharge more reliably and maintaining the battery temperature more efficiently.

  According to the present invention, an in-vehicle battery charging control system capable of both charging an in-vehicle battery and maintaining the battery temperature even when a plurality of vehicles are connected to an external power supply device in a low temperature environment is provided. can do.

The block diagram which shows the structure in a charge control system. The circuit diagram which shows the relationship between an external charging device, a vehicle-mounted battery, and a battery heater with a circuit. The timing chart which shows the time change of battery current, battery temperature, and a charging rate. The sequence diagram which shows the processing operation | movement in a charge control system, and the transmission / reception operation | movement of various signals. The timing chart which shows the charging / discharging cycle in each vehicle. The flowchart which shows operation | movement of a charging / discharging cycle process. Explanatory drawing explaining the flow of the electric current in a charge control system. The timing chart which shows the charging / discharging cycle in another embodiment.

An embodiment of the present invention will be described below with reference to the drawings.
The charge control system 1 according to the present embodiment is a battery of an in-vehicle battery in a low-temperature environment in a state where an in-vehicle battery of a vehicle 10 such as an electric vehicle and an external charging device 20 for charging the in-vehicle battery are connected. The temperature is maintained within an appropriate temperature range.

Such a charge control system 1 will be described in detail with reference to FIGS. 1 to 3.
1 shows a block diagram of the configuration in the charging control system 1, FIG. 2 shows a circuit diagram of the relationship between the external charging device 20, the in-vehicle battery 11 and the battery heater 14, and FIG. 3 shows battery current, battery temperature, And the timing chart of a charging rate is shown.
In FIG. 2, detailed illustration of the external charging device 20 is omitted, and the external charging device 20 is illustrated with a DC power source and a switch based on the function thereof.

As shown in FIG. 1, the charging control system 1 supplies electric power from the outside to a vehicle 10 such as an electric vehicle and an in-vehicle battery 11 of the vehicle 10 and can connect three vehicles 10 at one time. And two external charging devices 20.
Since the three vehicles 10 all have the same configuration, the following description will be made using the vehicle 10 (10a) connected to the first charger 22 of the external charging device 20 described later.

  As shown in FIG. 1, the vehicle 10 is electrically connected to the in-vehicle battery 11 that can be charged and discharged, the battery temperature sensor 12 that detects the temperature of the in-vehicle battery 11, the outside air temperature sensor 13 that detects the outside air temperature, Connected to the battery heater 14, the drive motor 15 electrically connected to the in-vehicle battery 11, the charger connecting portion 16 to which the external charging device 20 is connected, and electrically connected thereto. And an electronic control unit (hereinafter referred to as “ECU”) 17 for controlling these operations.

  The in-vehicle battery 11 is a lithium ion secondary battery, and as shown in FIG. 2, the cell module 11a in which a plurality of cells (not shown) having the same output characteristics are connected in series and the conduction to the cell module 11a are switched. It consists of a switch 11b. The in-vehicle battery 11 is alternatively connected to the drive motor 15 or the charger connection unit 16 via a changeover switch that switches electrical connection to the drive motor 15 and the charger connection unit 16.

The battery temperature sensor 12 is a temperature sensor mounted at an appropriate position of the in-vehicle battery 11 and has a function of detecting the temperature of the in-vehicle battery 11 and a function of outputting the detected temperature to the ECU 17 as a battery temperature signal. doing.
The outside air temperature sensor 13 is a temperature sensor arranged at a position where the ambient temperature of the in-vehicle battery 11 can be detected, and has a function of detecting the outside air temperature and a function of outputting the detected outside air temperature to the ECU 17 as an outside air temperature signal. have.

  The battery heater 14 is an electric heater disposed in the vicinity of the in-vehicle battery 11, and includes a heating element 14a having a high resistance value and a switch 14b for switching power supply to the heating element 14a as shown in FIG. ing. The battery heater 14 has a function of generating heat of a calorific value that maintains the temperature of the in-vehicle battery 11 by the electric power from the in-vehicle battery 11.

  The drive motor 15 is, for example, an electric motor disposed in an engine room (not shown) at the front of the vehicle, and has a function of generating a driving force transmitted to the wheels by electric power supplied from the in-vehicle battery 11. doing.

  The charger connection unit 16 is a connection unit that is disposed at an appropriate part of the vehicle 10 and to which a connection cable (not shown) of the external charging device 20 is connected. The charger connection unit 16 includes a power receiving unit 16 a that receives supply of power from the external charging device 20 and a communication unit 16 b that communicates with the external charging device 20.

The power reception unit 16a has a function of receiving DC power output from the external charging device 20 via a connection cable and a function of supplying the received DC current to the in-vehicle battery 11.
The communication unit 16b has a function of transmitting various signals to the external charging device 20 based on an instruction from the ECU 17, a function of receiving various signals output from the external charging device 20, and a function of outputting the received various signals to the ECU 17. have.

  The ECU 17 is configured with a hardware configuration such as a CPU and a memory, and a software configuration such as a program and data. The ECU 17 is electrically connected to a lead storage battery (not shown) and is operated by the power of the lead storage battery.

  Further, when the battery temperature rises due to charging, the ECU 17 stabilizes the vehicle 10 under a low temperature environment and an upper limit temperature that is a battery temperature that can ensure both stable output and safety. The lower limit temperature, which is the battery temperature at which an output that can be started, is obtained, the upper limit charging rate of the charging target that is the range of the charging rate that is charged when charging the vehicle-mounted battery 11, the lower limit charging rate, and the like are stored in advance. .

  For example, the ECU 17 stores 60 ° C. as the upper limit temperature of the battery temperature, stores 25 ° C. as the lower limit temperature of the battery temperature, and ranges from a charging rate of 80% to a charging rate of 100% as a range of charging rate at which charging is completed. Is remembered.

On the other hand, the external charging device 20 is configured to be electrically connected to the AC power network 2 and connectable to three vehicles 10 at a time.
More specifically, as shown in FIG. 1, the external charging device 20 includes a power conversion unit 21 electrically connected to the AC power network 2, a first charger 22 and a second charger 23 to which the vehicle 10 is connected. , And a third charger 24 and a charge control unit 25 for controlling these operations.

  The power conversion unit 21 includes a switch that switches an electrical connection between the circuit breaker, the AC / DC converter, and the first charger 22, the second charger 23, or the third charger 24. The power conversion unit 21 converts the AC power from the AC power network 2 into DC power, and the first charger 22, the second charger 23, or the third charger based on an instruction from the charge control unit 25. 24 has a function of outputting DC power.

  The first charger 22 includes a connection cable (not shown) connected to the vehicle 10, a power supply unit 22a that supplies DC power to the vehicle 10 via the connection cable, and a communication unit 16b of the vehicle 10 via the connection cable. And a communication unit 22b that performs communication.

The power feeding unit 22 a has a function of outputting the DC power output from the power conversion unit 21 to the vehicle 10 via the connection cable based on an instruction from the charging control unit 25.
The communication unit 22b is configured to transmit various signals to the vehicle 10 based on instructions from the charging control unit 25, to receive various signals output from the communication unit 16b of the vehicle 10, and to charge the received various signals. 25.

The second charger 23 includes a power feeding unit 23a and a communication unit 23b. Since the second charger 23 has the same configuration as the first charger 22, detailed description thereof is omitted.
The third charger 24 includes a power feeding unit 24a and a communication unit 24b. Since the third charger 24 has the same configuration as the first charger 22, detailed description thereof is omitted.

The charging control unit 25 includes a CPU and a memory with a hardware configuration and a software configuration such as a program and data. The charging control unit 25 has a function of controlling the supply of DC power output from the power conversion unit 21 to the vehicle 10 and a function of controlling the timing of supplying DC power to a plurality of connected vehicles 10. Have.
Further, the charge control unit 25 stores in advance a required time ΔT of a charge / discharge cycle to be described later, and a charge time ΔT _c for supplying power to the connected vehicle 10.

Here, one charge / discharge cycle will be described with reference to FIG.
As shown in FIG. 3, the charging / discharging cycle per time indicates charging, standby, and discharging cycles in the in-vehicle battery 11 in a state where the vehicle 10 is connected to the external charging device 20.

  More specifically, as shown in FIG. 3, the charge / discharge cycle per time is controlled so that current is input to the in-vehicle battery 11 until the elapsed time reaches time t1, and time t1 From the time t2 to the time t2, and the process for controlling the current input / output of the in-vehicle battery 11 to be stopped, and the control from the time t2 to the time t3 so that the current is output from the on-vehicle battery 11 to the battery heater 14. The processes performed in this order are regarded as one cycle.

  That is, the charging / discharging cycle comprises one cycle with a charging process for charging the in-vehicle battery 11, a standby process for waiting for charging / discharging of the in-vehicle battery 11, and a discharging process for discharging the electric power of the in-vehicle battery 11. Yes.

In this charging / discharging cycle, the required time ΔT per time described above includes a charging time ΔT _c that is a time required for the charging process, a waiting time ΔT _w that is a time required for the standby process, and a discharge as shown in FIG. it is the total time is the time required to process the discharge time [Delta] T _d.

Among these, the required time ΔT and the charging time ΔT _c are stored in the charging control unit 25 of the external charging device 20, and the standby time ΔT _w and the discharging time ΔT _d are based on the outside air temperature and the battery temperature in the vehicle 10. Thus, the time length is calculated to be adjusted.

As described above, the required time ΔT is stored in advance in the charge control unit 25 and is set to 600 sec, for example.
On the other hand, the charging time ΔT _c stored in the charging control unit 25 is defined by the following equation 1.

例えば、本実施形態では外部充電装置２０の最大接続台数が３台のため、所要時間ΔＴを例えば６００ｓｅｃとした場合、充電時間ΔＴ_ｃは、ΔＴ_ｃ＝６００／３＝２００ｓｅｃとなる。

For example, in this embodiment, since the maximum number of external charging devices 20 that can be connected is three, if the required time ΔT is set to 600 sec, for example, the charging time ΔT _c is ΔT _c = 600/3 = 200 sec.

Next, operations in charging the three vehicles 10 in the charging control system 1 having the above-described configuration will be described with reference to FIGS.
In the present embodiment, for ease of explanation, as shown in FIG. 1, the vehicle 10 connected to the first charger 22 is a vehicle 10a, and the vehicle 10 connected to the second charger 23 is a vehicle. The vehicle 10 connected to the third charger 24 will be described as a vehicle 10c.

  4 shows a sequence diagram of processing operations in the charge control system 1 and various signal transmission / reception operations, FIG. 5 shows a timing chart of charge / discharge cycles in each vehicle 10, and FIG. 6 shows operations of charge / discharge cycle processing. FIG. 7 is an explanatory diagram for explaining the current flow X in the charge control system 1.

  5A shows a timing chart of the input / output current of the in-vehicle battery 11 in the vehicle 10a to which the first charger 22 is connected, and FIG. 5B shows the vehicle 10b to which the second charger 23 is connected. FIG. 5C shows a timing chart of the input / output current of the in-vehicle battery 11 in the vehicle 10c to which the third charger 24 is connected.

7A shows the state of each switch in the charging process, FIG. 7B shows the state of each switch in the standby process, and FIG. 7C shows the state of each switch in the discharging process. Yes.
Further, in the present embodiment, when the third charger 24 is connected to the vehicle 10c in a state where the first charger 22 and the second charger 23 of the external charging device 20 are connected to the vehicles 10a and 10b, respectively. Will be described.

  First, when receiving power supply from the AC power network 2, the charging control unit 25 of the external charging device 20 starts the processing operation as shown in FIG. 4, and whether the third charger 24 is connected to the vehicle 10c. It is determined whether or not (step S101). When the third charger 24 is not connected to the vehicle 10c (step S101: No), the charging control unit 25 waits for processing until it is connected to the vehicle 10c.

On the other hand, when the third charger 24 is connected to the vehicle 10c (step S101: Yes), the charge control unit 25 starts the condition transmission process (step S102), and the required time ΔT for one charge / discharge cycle. The required time information indicating the charging time and the charging time information indicating the charging time ΔT _c are transmitted to the vehicle 10c via the connection cable.

  And ECU17 of the vehicle 10c which received required time information and charging time information starts the charging / discharging condition calculation process which calculates the detailed conditions of the charging / discharging cycle per time, as shown in FIG. 4 (step S103). ).

Specifically, the ECU 17 is a standby time ΔT _w , a discharge time ΔT _d , and an input current for charging the in-vehicle battery 11 based on the required time ΔT and the charging time ΔT _c acquired from the external charging device 20. A charging current I _c and a discharging current I _d that is an output current for discharging to the battery heater 14 are calculated.
Of these, the discharge current I _d is Teigizuke by the following equation 2.

Further, the discharge time ΔT _d is calculated based on the amount of heat generated by the in-vehicle battery 11, the amount of heat received by the in-vehicle battery 11 from the battery heater 14, and the amount of heat released from the surface of the in-vehicle battery 11.
More specifically, the ECU 17 calculates the following equation 3 indicating a relational expression between the amount of heat generated by adding the amount of heat received from the battery heater 14 to the amount of internal heat generated by the vehicle-mounted battery 11 and the amount of heat released from the surface of the vehicle-mounted battery 11. A satisfactory discharge time ΔT _d is calculated.

In the above formula 3, the internal heating value Q _bc of the in-vehicle battery 11 in the charging process, the internal heating value Q _bd of the in-vehicle battery 11 in the discharging process, the heating value Q _h of the battery heater 14, and the heat dissipation from the surface of the in-vehicle battery 11. Q _out is defined by the following Equation 4, Equation 5, Equation 6, and Equation 7, respectively.

In the above-described equation 3, the internal heat generation amount Q _bc of the in-vehicle battery 11 in the charging process of equation 4, the internal heat generation amount Q _bd of the in-vehicle battery 11 in the discharging step of equation 5, the heat generation amount Q _h of the battery heater 14 in equation 6 When the heat radiation amount Q _out from the surface of the in-vehicle battery 11 in Expression 7 is substituted, Expression 3 can be replaced with Expression 8 below.

The charging current I _c is Teigizuke by the following equation 9 showing the relationship between the charge rate after charge step and the charge rate after the discharge process.

Then, based on the required time ΔT and the charging time ΔT _c acquired from the external charging device 20 and the discharge current I _d defined by the above-described equation 2, the discharge satisfying the above-described equation 8 and the above-mentioned equation 9 When the time ΔT _d and the charging current I _c are calculated, they are defined by the following equations 10 and 11, respectively.

In this way, the ECU 17 calculates the discharge time ΔT _d , the charging current I _c , and the discharging current I _d .
Further, the ECU 17 subtracts the charging time ΔT _c and the discharging time ΔT _d from the required time ΔT to calculate the standby time ΔT _w .

  Returning to step S103 in FIG. 4, when the charge / discharge condition calculation processing is completed, the ECU 17 outputs a preparation completion signal indicating that preparation for charging the vehicle-mounted battery 11 is completed to the external charging device 20 via the connection cable. (Step S104).

  When the preparation completion signal is received, the charging control unit 25 of the external charging device 20 receives the vehicle 10a connected to the first charger 22 or the vehicle 10b connected to the second charger 23 as shown in FIG. It is determined whether or not it is a charging process (step S105).

  When the vehicle 10a connected to the first charger 22 or the vehicle 10b connected to the second charger 23 is in the charging process (step S105: Yes), the charging control unit 25 is connected to the third charger 24. The shift process for delaying the start timing of the charging process in the vehicle 10c is started (step S106).

  At this time, the charging control unit 25 performs the charging process of the vehicle 10c so as not to overlap the charging process of the vehicle 10a connected to the first charger 22 or the charging process of the vehicle 10b connected to the second charger 23. Is adjusted by shifting the start timing to the rear of the time axis.

  That is, the charging control unit 25 sets the start timing of the charging process in each vehicle 10 so that the charging process of the vehicle 10c is started when the charge / discharge cycle in the other vehicle 10 is a standby process or / and a discharging process. adjust.

  More specifically, when the third charger 24 and the vehicle 10c are connected, as shown in FIG. 5, after the charging process of the vehicle 10a to which the first charger 22 is connected is performed until time t4, It is assumed that the charging / discharging cycle of the vehicle 10b is adjusted with respect to the charging / discharging cycle of the vehicle 10a so that the charging process of the vehicle 10b to which the two chargers 23 are connected is performed until time t5.

  In such a state, when the time when it is determined whether the other vehicle 10 is in the charging process is less than time t4, the vehicle 10a is in the charging process from time t4, and the vehicle 10b is in the charging process from time t4 to time t5. The charging control unit 25 delays the start time of the charging process so that the charging process of the vehicle 10c to which the third charger 24 is connected is started when the time t5 when the charging process of the vehicle 10b ends is reached. .

  Alternatively, when the time when it is determined whether or not the other vehicle 10 is in the charging process is not less than time t4 and less than time t5, the vehicle 10a is in the standby process, but the vehicle 10b is in the charging process. When the time t5 when the charging process ends is reached, the start time of the charging process is delayed so that the charging process of the vehicle 10c is started.

  When the shift process is completed, the charging control unit 25 determines whether or not it is a start time for starting the charging process of the vehicle 10c connected to the third charger 24 as shown in FIG. 4 (step S107). When the current time is not the start time when the charging process of the vehicle 10c is started (step S107: No), the charging control unit 25 waits for the process until the starting time when the charging process of the vehicle 10c is started.

  On the other hand, when the current time is the start time when the charging process of the vehicle 10c is started (step S107: Yes), the charging control unit 25 starts to supply power to the vehicle 10c connected to the third charger 24. A power supply start signal indicating that the operation is to be performed is output (step S108). Thereafter, the charging control unit 25 starts to supply power to the vehicle 10 c connected to the third charger 24.

In step S108, when the power supply start signal transmitted by the external charging device 20 is received, the ECU 17 of the vehicle 10c starts a charge / discharge cycle process (step S109).
More specifically, as shown in FIG. 6, the ECU 17 that has started the charge / discharge cycle process starts the first switch state switching process (step S <b> 121), turns on the switch 11 b of the in-vehicle battery 11, and the battery heater The 14 switches 14b are turned off (see FIG. 7A).

For this reason, as shown in FIG. 7A, the current flow X passes from the external charging device 20 through the charger connection unit 16 in the order of the switch 11b of the in-vehicle battery 11 and the cell module 11a, and again. The flow returns to the external charging device 20 via the charger connection unit 16.
At this time, the vehicle-mounted battery 11 is, as shown in FIG. 3, the charging current I _c is input, battery temperature, and the charging rate is increased with time.

Thereafter, as shown in FIG. 6, the ECU 17 determines whether or not the charging process is completed (step S122). At this time, as shown in FIG. 3, the ECU 17 determines that the charging process is completed when the elapsed time from the start of the charging process reaches the time t1, that is, when charging is performed for the charging time ΔT _c . Alternatively, when the battery temperature reaches the upper limit temperature, or when the charging rate of the in-vehicle battery 11 reaches the upper limit charging rate of the charging target, it is determined that the charging process is finished.

In step S121, when the charging process is not completed (step S122: No), the ECU 17 waits for the process until the charging process is completed.
On the other hand, when the charging process is completed (step S122: Yes), the ECU 17 starts a second switch state switching process for switching the state of the switch 11b in the in-vehicle battery 11 (step S123).

  Specifically, the ECU 17 switches the switch 11b of the in-vehicle battery 11 from the on state to the off state, as shown in FIGS. 7 (a) and 7 (b). At this time, the ECU 17 outputs a stop signal for stopping the supply of power to the external charging device 20.

And the charge control part 25 of the external charging device 20 which received the stop signal interrupts | blocks the electric power supply to the vehicle 10c via the 3rd charger 24, as shown in FIG.7 (b). For this reason, the vehicle 10c shifts to a standby state in which the vehicle-mounted battery 11 waits for charging / discharging.
At this time, as shown in FIG. 3, the in-vehicle battery 11 has no change in the charging rate, but the battery temperature decreases with time due to heat radiation to the atmosphere.

Thereafter, as shown in FIG. 6, the ECU 17 determines whether or not the standby process has ended (step S124). At this time, ECU 17, as shown in FIG. 3, when the elapsed time from the start of the charging process has reached the time t2, that is, if you have only continue wait state waiting time [Delta] T _w, standby step is completed and judge. Alternatively, the ECU 17 determines that the standby process has ended when the battery temperature has reached the lower limit temperature.

  When the standby process is not completed (step S124: No), the ECU 17 waits for the process until the standby process is completed. On the other hand, when the standby process is completed (step S124: Yes), the ECU 17 starts a third switch state switching process for switching the state of the switch 11b of the in-vehicle battery 11 and the switch 11b of the battery heater 14 (step S125).

  Specifically, as shown in FIGS. 7B and 7C, the ECU 17 switches the switch 11b of the in-vehicle battery 11 from the off state to the on state, and turns off the switch 14b of the battery heater 14. To turn it on.

  Therefore, as shown in FIG. 7C, the current flow X passes through the cell module 11a of the in-vehicle battery 11 through the switch 11b, the switch 14b of the battery heater 14 and the heating element 14a in order. The flow returns to the module 11a.

At this time, the vehicle-mounted battery 11 is, as shown in FIG. 3, the discharge current I _d only by discharging the battery heater 14, the charging rate decreases gradually with the lapse of time. Furthermore, the battery temperature of the in-vehicle battery 11 is maintained at a constant temperature within the range between the upper limit temperature and the lower limit temperature by heat received from the battery heater 14 and self-heating due to discharge to the battery heater 14.

Thereafter, as shown in FIG. 6, the ECU 17 determines whether or not the discharging process has ended (step S126). At this time, ECU 17 determines, as shown in FIG. 3, when the elapsed time from the start of the charging process has reached a time t3, i.e. when discharged by the discharge time [Delta] T _d, the discharge process is finished. Alternatively, when the charging rate of the in-vehicle battery 11 reaches the lower limit charging rate of the charging target, it is determined that the discharging process is finished.

  When the discharge process has not ended (step S126: No), the ECU 17 waits for the process until the discharge process ends. On the other hand, when the discharging process is completed (step S126: Yes), the ECU 17 starts the second switch state switching process (step S127), and similarly to step S123 described above, the switch 11b of the in-vehicle battery 11 and the battery Each switch 14b of the heater 14 is turned off (see FIG. 7B).

  Thereafter, the ECU 17 outputs a one-cycle end signal indicating that one charge / discharge cycle has ended to the external charging device 20 via the connection cable (step S128), and then ends the charge / discharge cycle process. The process returns to step S109 in FIG.

  Returning to step S109 in FIG. 4, when a one-cycle end signal is received from the vehicle 10c to which the third charger is connected, the charging control unit 25 of the external charging device 20 performs the operation of the occupant as shown in FIG. It is determined whether or not the connection with the vehicle 10c has been released (step S110).

When the connection with the vehicle 10c is released (step S110: Yes), the charging control unit 25 ends the processing operation for the vehicle 10c.
On the other hand, when the connection with the vehicle 10c is not released (step S110: No), the charging control unit 25 returns the process to step S105. Thereafter, the charging control system 1 repeatedly executes the charging / discharging cycle by repeating the processing from step S105 to step S110 until the connection with the vehicle 10c is released.

  4, when the vehicle 10a connected to the first charger 22 or the vehicle 10b connected to the second charger 23 is not in the charging process (step S105: No), the charging control unit 25 is Then, the process proceeds to step S108, and a power supply start signal is output.

  Thereafter, in the charge / discharge cycle process of step S109, the ECU 17 of the vehicle 10 immediately starts the charge process of the charge / discharge cycle. In this case, the time when the charging process is started is not less than time t4 when the charging process of the vehicle 10b is completed and not more than time t6 when the discharging process of the vehicle 10a is completed.

  In this way, the charging control system 1 charges the in-vehicle batteries 11 of all the vehicles 10 connected to the external charging device 20, and maintains the battery temperature of the in-vehicle batteries 11 within the range between the upper limit temperature and the lower limit temperature. .

  The charging control system 1 for the in-vehicle battery 11 that realizes the operation as described above can charge the in-vehicle battery 11 even when a plurality of vehicles 10 are connected to the external charging device 20 in a low temperature environment. Both maintenance of the battery temperature can be achieved.

  Specifically, the charging control system 1 increases the temperature of the in-vehicle battery 11 by the charging process, and waits by repeating the charging / discharging cycle with the charging process, the standby process, and the discharging process as one charge / discharge cycle. It is possible to repeat the natural cooling of the in-vehicle battery 11 by the above and the temperature maintenance of the in-vehicle battery 11 by the discharging process.

  At this time, since the discharging process is performed so as to maintain the battery temperature, the charge control system 1 can suppress the discharge amount as compared with the discharge amount for raising the temperature of the in-vehicle battery 11. For this reason, the charging control system 1 can maintain the battery temperature while suppressing a decrease in the charging rate.

  And when the some vehicle 10 is connected to the external charging device 20, between the vehicles 10 so that a charge process may be started when the charging / discharging cycle in another vehicle 10 is a standby process or / and a discharge process. By controlling the start timing of the charge / discharge cycle, the charge control system 1 can prevent the charging process from being performed simultaneously among the plurality of vehicles 10. For this reason, the charge control system 1 can prevent the total power supplied to the plurality of in-vehicle batteries 11 from exceeding the contract power capacity.

  Furthermore, since the standby process is provided between the charging process and the discharging process, the charging control system 1 can provide power to the in-vehicle battery 11 as compared with the case where the charging process and the discharging process are performed as one charge / discharge cycle. A long time for stopping the supply can be secured. For this reason, even if the charging control system 1 is a case where the some vehicle 10 is connected to the external charging device 20, it can ensure the charging time per 101 vehicles stably.

In addition, if the number of vehicles 10 which are connected to the external charging device 20 is large, the charge control system 1 of the in-vehicle battery 11, for example, by adjusting the waiting time [Delta] T _w, to all of the in-vehicle battery 11 connected Can be easily charged. For this reason, the charging control system 1 for the in-vehicle battery 11 can flexibly cope with the increase or decrease of the vehicle 10 connected to the external charging device 20.

  Accordingly, the charging control system 1 can achieve both charging of the in-vehicle battery 11 and maintenance of the battery temperature even when a plurality of vehicles 10 are connected to the external charging device 20 in a low temperature environment. it can.

Also, the wait time [Delta] T _w in a single charge-discharge cycle, by controlling on the basis of the outside air temperature and the battery temperature, the charging control system 1 is to prevent unnecessary discharge, more efficient battery temperature Can be maintained.

Specifically, the battery temperature of the in-vehicle battery 11 decreases with time due to heat radiation to the atmosphere when charging and discharging are not performed. Therefore, in a low temperature environment, the waiting time [Delta] T _w is prolonged, the battery temperature of the vehicle battery 11, which may fall below the minimum temperature.
Furthermore, in this case, since it is necessary to raise the in-vehicle battery 11 to the lower limit temperature at the start of the discharging step, there is a possibility that the charging rate is lower than the predetermined charging rate due to excessive discharge.

Therefore, by controlling the standby time based on the outside air temperature and the battery temperature, the charging control system 1 starts the discharging process before the battery temperature of the in-vehicle battery 11 falls below the lower limit temperature in a low temperature environment. be able to.
Therefore, the charge control system 1 controls the waiting time [Delta] T _w based on the outside air temperature and the battery temperature can be maintained by preventing unnecessary discharge more reliably, the battery temperature more efficiently .

In correspondence between the configuration of the present invention and the above-described embodiment,
The external power supply device of the present invention corresponds to the external charging device 20 of the embodiment,
Similarly,
The range of the predetermined charging rate corresponds to the range of the upper limit charging rate and the lower limit charging rate of the charging target,
The predetermined temperature range corresponds to the range between the upper limit temperature and the lower limit temperature of the battery temperature,
The charge / discharge control means corresponds to the ECU 17 of the vehicle 10 and the charge control unit 25 of the external charging device 20,
The timing control means corresponds to the charging control unit 25 of the external charging device 20,
The outside air temperature detection means corresponds to the outside air temperature sensor 13 and the ECU 17 of the vehicle 10,
Control time of the standby control, but corresponds to the waiting time ΔT _w,
The present invention is not limited only to the configuration of the above-described embodiment, and many embodiments can be obtained.

  For example, in the above-described embodiment, the vehicle 10 is an electric vehicle. However, the present invention is not limited to this, and the vehicle 10 includes an in-vehicle battery 11 for rotating the drive motor 15 and is supplied with electric power supplied from the outside of the vehicle 10. For example, a plug-in hybrid vehicle may be used as long as the vehicle battery 11 is charged.

  Further, although the outside air temperature sensor 13 that detects the outside air temperature is provided in the vehicle 10, the outside air temperature sensor may be provided in the external charging device 20 without being limited thereto. In this case, in the condition transmission process in step S102 of FIG. 4, outside temperature information indicating the outside temperature is transmitted to the vehicle 10 in addition to the required time information and the charging time information.

  Moreover, although the vehicle 10 was connected to the 1st charger 22 and the 2nd charger 23, respectively, and the case where the vehicle 10 was connected to the 3rd charger 24 was demonstrated, it is not limited to this, The 1st charger 22, the second charger 23, and the third charger 24 are connected to the vehicle 10, or the first charger 22, the second charger 23, and the third charger 24 are all vehicles. 10 may not be connected.

  Moreover, although it was set as the structure provided with the battery heater 14 in order to heat-retain the vehicle-mounted battery 11, it is not limited to this, It is good also as a vehicle-mounted battery incorporating the resistor which becomes a heat generating body. Or it is good also as a structure which does not provide the battery heater 14 etc. but maintains the battery temperature of the vehicle-mounted battery 11 by the self-heating by discharge.

  Further, the ECU 17 of the vehicle 10 and the charging control unit 25 of the external charging device 20 cooperate to control charging / discharging and standby in the in-vehicle battery 11 and control the start timing of the charging / discharging cycle. Without being limited thereto, the charging control unit 25 of the external charging device 20 may control charging / discharging and standby in the in-vehicle battery 11 and control the start timing of the charging / discharging cycle.

For example, when the vehicle 10 is connected to the external charging device 20, the external charging control unit 25 of the external charging device 20 acquires various information such as the charging rate of the in-vehicle battery, the battery temperature, and the internal resistance value from the vehicle 10. , Charging current I _c , charging time ΔT _c , standby time ΔT _w , discharging current I _d , and discharging time ΔT _d are calculated.

  And the charging control part 25 controls the electric power feeding from the external charging device 20 to the vehicle-mounted battery 11 by carrying out on-off control of the switch provided in the external charging device 20, and controls a charging process and a standby process. Furthermore, the charging control unit 25 may be configured to discharge the in-vehicle battery 11 by connecting the in-vehicle battery 11 of the vehicle 10 to a load device provided in the external charging device 20.

In addition, the charging control system 1 is configured such that a maximum of three vehicles 10 can be connected to one external charging device 20. However, the present invention is not limited thereto, and an appropriate number of vehicles can be connected to one external charging device 20. It is good also as a structure which can be connected.
For example, as shown in FIG. 8 showing a timing chart of a charge / discharge cycle in another embodiment, a charge control system 1 in which up to ten vehicles 10 can be connected to one external charging device 20 may be used.

  8A shows a timing chart of the charge / discharge cycle in the vehicle connected to the first charger, and FIG. 8B shows the timing of the charge / discharge cycle in the vehicle connected to the second charger. FIG. 8C shows a timing chart of the charge / discharge cycle in the vehicle connected to the third charger, and FIG. 8D shows the charge / discharge cycle in the vehicle connected to the ninth charger. FIG. 8E shows a timing chart of a charge / discharge cycle in the vehicle connected to the tenth charger.

In this case, the wait time [Delta] T _w in a single charge-discharge cycle, as shown in FIG. 8, connectable number is longer than the wait time [Delta] T _w in the case of three. Further, the charging time [Delta] T _c, as well as shorter than the charging time [Delta] T _c when connectable number is three, the charging current I _c, than the charging current I _c when connectable number is three Increase the value. Thereby, the charge control system 1 can have the same effect as the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 ... Charge control system 10 ... Vehicle 10a ... Vehicle 10b ... Vehicle 10c ... Vehicle 11 ... In-vehicle battery 13 ... Outside temperature sensor 17 ... ECU
20 ... external charging device 25 ... charging control unit ΔT w _... the waiting time

Claims (2)

An in-vehicle battery mounted on the vehicle;
An external power supply device that is electrically connected to the in-vehicle battery and supplies external power to the in-vehicle battery from outside the vehicle;
Charge / discharge control for controlling charging / discharging of the in-vehicle battery within a predetermined charging rate range of the in-vehicle battery and controlling discharging of the in-vehicle battery so as to maintain a battery temperature of the in-vehicle battery within a predetermined temperature range. A vehicle-mounted battery charging control system comprising:
The charge / discharge control means
The charging control for charging the in-vehicle battery, the standby control for waiting for charging / discharging of the in-vehicle battery, and the discharging control for discharging the in-vehicle battery are performed in this order, and the charging control, the standby control, and the discharging control are performed. As one charge / discharge cycle, the charge / discharge cycle is repeated,
The external power supply device is configured such that a plurality of the vehicles can be connected,
When the plurality of vehicles are connected to the external power supply device, comprising timing control means for controlling the start timing of the charge / discharge cycle between the plurality of vehicles,
The timing control means
A vehicle-mounted battery configured to control the start timing of the charge / discharge cycle between the vehicles so that the charge control is started when the charge / discharge cycle in another vehicle is the standby control or / and the discharge control. Charging control system. An outside air temperature detecting means for detecting the outside air temperature,
The timing control means;
The in-vehicle battery charge control system according to claim 1, wherein the control time of the standby control in the one charge / discharge cycle is controlled based on the detected outside air temperature.

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