JP6424596B2 - Vehicle charge control device - Google Patents

Description

  The present invention relates to a charge control device for a vehicle.

  2. Description of the Related Art A technology for mounting a storage device (battery) including a secondary battery or the like on a vehicle and charging the storage device by an external charging device outside the vehicle has been put to practical use. In addition, when the battery is charged under conditions of extremely low temperature in a cold region or the like, since the internal resistance of the battery is high, charging loss may be large, and inconveniences such as prolongation of charging time may be concerned. Therefore, there has been proposed a technique for warming up the battery at the time of charging the battery under a very low temperature condition.

  For example, according to the technology described in Patent Document 1, warm-up of the battery is started in a configuration in which normal charging and rapid charging for causing heat generation larger than normal charging are selectively performed when charging the battery by the external charging device. The battery is warmed up by starting the rapid charging at the time.

Unexamined-Japanese-Patent No. 2010-110196

  However, in the above-mentioned prior art, there is a concern that the battery deterioration may be advanced by performing the rapid charge of the battery during the cryogenic temperature. For example, in a lithium ion battery, there is a concern that lithium may be deposited on the surface of the negative electrode to accelerate deterioration (decrease in capacity) by continuing charging of a large current under extremely low temperature conditions. Therefore, it is desirable to limit the charge current of the battery during cryogenic temperatures.

  However, limiting the charging current under cryogenic conditions will limit the ability of the external charging device to supply current. Therefore, it is considered that a decrease in efficiency occurs when the current supply from the external charging device is performed.

  The present invention has been made in view of the above circumstances, and a main object thereof is to provide a charge control device for a vehicle capable of appropriately performing external charging of a power storage device even in a low temperature state.

  The charge control device for a vehicle according to the present invention includes a chargeable and dischargeable power storage device (11) and a heating means (25) for heating the power storage device, and an external current supplied from an external power supply (40) outside the vehicle. It applies to the vehicle which implements charge with respect to the said electrical storage apparatus. Then, first setting means for setting a supply current supplied to the vehicle from the external power supply, second setting means for setting a charging current to the power storage device based on the temperature of the power storage device, and Warm-up control means for performing warm-up of the power storage device by heating of the heating means using a residual current obtained by subtracting the charging current set by the second setting means from the supply current set by the setting means; And the like.

  According to the above configuration, the charging current to the power storage device is set based on the temperature of the power storage device. This makes it possible to limit the charging current under extremely low temperature conditions, and to suppress the deterioration of the power storage device. Further, the storage device is warmed up by the heating of the heating unit using the remaining current obtained by subtracting the charging current to the storage device from the supply current supplied to the vehicle from the external power supply. In this case, the current supply capacity of the external power supply is hard to be restricted by making effective use of the current of the external power supply remaining due to the limitation of the charging current to the power storage device for warming up the power storage device. It can charge the device. As a result, external charging of the power storage device can be appropriately performed even in a low temperature state.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows the whole of the charge system of a vehicle. The flowchart which shows the processing procedure of battery external charge. The figure which shows the relationship between battery temperature, SOC, and charge limit current. The time chart for demonstrating battery external charge more concretely.

  Hereinafter, an embodiment in which the charge control device of the present invention is embodied will be described with reference to the drawings. In this embodiment, in a hybrid vehicle including an engine and a motor as a power source for traveling, a configuration for charging a vehicle-mounted battery with external power is illustrated, and the schematic configuration is shown in FIG. However, FIG. 1 mainly describes the configuration of the battery and the motor generator driven by the power supply from the battery, and the illustration of the engine and other configurations is omitted.

  In FIG. 1, a vehicle 10 includes a battery 11 as a chargeable / dischargeable power storage device, a PCU 12 (Power Control Unit), a motor generator 13, a PM-ECU 14 (PM: Power Management), and a battery monitoring unit 15. And an SMR 16 (System Main Relay). The battery 11 is configured by, for example, a secondary battery such as a lithium ion battery or a nickel hydrogen battery. The output voltage of the battery 11 is about 200V. Note that the power storage device can also be configured by an electric double layer capacitor or a combination of a secondary battery and a capacitor. The battery 11 is provided in the vehicle cabin or in the vicinity of the vehicle cabin. Specifically, the battery 11 is provided in a seat lower portion, a floor lower portion, a rear loading platform portion or the like in the vehicle cabin.

  The PCU 12 has a DCDC converter 21 and an inverter 22 for converting the stored power of the battery 11 into a drive power for the motor generator 13, and an MG-ECU 23 for controlling the drive of the inverter 22. The motor generator 13 is formed of, for example, a permanent magnet type three-phase synchronous motor, and is driven by the power of the battery 11 supplied via the PCU 12. At the time of braking of the vehicle 10, the motor generator 13 generates regenerative power, and the battery 11 is charged by the generated power.

  The PM-ECU 14 and the MG-ECU 23 are composed of a known electronic control unit having a CPU and a memory, and perform various arithmetic processing based on programs and maps stored in the memory. The respective ECUs 14 and 23 and the PLG-ECU 31 described later are connected via communication lines, and can mutually communicate various information.

  The battery monitoring unit 15 monitors the state (voltage, current, temperature, etc.) of the battery 11 by various sensors, and outputs the monitoring result to the PM-ECU 14. The battery monitoring unit 15 has at least a temperature detection unit 15a, and outputs the detection result of the battery temperature by a battery temperature sensor (not shown) from the temperature detection unit 15a to the PM-ECU 14.

  The PM-ECU 14 controls the overall operation of the vehicle 10. For example, the PM-ECU 14 calculates the required driving force of the vehicle 10 based on the vehicle operation by the driver, the vehicle state, etc., and outputs the control command calculated based on the required driving force to the MG-ECU 23 . MG-ECU 23 controls the drive of motor generator 13 based on a control command from PM-ECU 14. Specifically, inverter 22 is controlled such that the output torque of motor generator 13 matches the torque command value. Further, the PM-ECU 14 calculates a state of charge (SOC) indicating the storage state of the battery 11 based on the monitoring result of the battery 11 by the battery monitoring unit 15.

  The SMR 16 has relay circuits respectively provided on the positive electrode terminal side and the negative electrode terminal side of the battery 11, and the on / off (opening and closing) of each relay circuit is controlled by the PM-ECU 14. When the SMR is off, the battery 11 and the PCU 12 are electrically disconnected, and when the SMR is on, the battery 11 and the PCU 12 are electrically conducted.

  In addition, the vehicle 10 includes an air conditioner 25 that performs air conditioning (heating and cooling) of the vehicle interior. The air conditioner 25 corresponds to a heating unit that is driven by the supply of power to heat the vehicle interior. The air conditioner 25 has an electric compressor (not shown), and the air conditioner 25 is driven by supplying electric power to the electric compressor.

  As described above, the battery 11 is provided in the vehicle cabin or in the vicinity of the vehicle cabin, and when the air conditioner 25 heats the vehicle cabin, the heat of the heating enables the battery 11 to be warmed up (heating). It has become.

  Further, the battery 11 of the vehicle 10 can be charged by an external charging device 40 as an external power supply. The vehicle 10 has a PLG-ECU 31 for controlling an external charging operation, a charging relay 32 provided in a charging path, a voltage sensor 33 for detecting a charging voltage, and an external charging port as a configuration related to battery external charging. And an inlet 34. With the external charging device 40 connected to the inlet 34 by the charging cable, charging of the battery 11 by the external charging device 40 is performed. When the charging cable is connected to the inlet 34, the PLG-ECU 31 and the external charging device 40 can communicate with each other, and the information on the external charging device 40 side can be obtained from the PLG-ECU 31 side. .

  The PLG-ECU 31 is formed of a known electronic control unit having a CPU and a memory, as with the above-described ECUs. The PLG-ECU 31 turns on (closes) the charging relay 32 during external charging by the external charging device 40. At this time, the SMR 16 is turned on by the PM-ECU 14 in response to the turning on of the charging relay 32 so that the charging path from the external charging device 40 to the battery 11 is opened, and power supply from the external charging device 40 Charging is performed.

  Further, the PLG-ECU 31 has a function of controlling the driving of the air conditioner 25, and heating of the air conditioner 25 is performed when the battery external charge is performed in the extremely low temperature state (for example, less than 0.degree. C.) of the battery 11. It is made to carry out.

  The external charging device 40 is a DC charger that supplies DC power to the vehicle 10, and the maximum supply current as the current supply capability is defined in advance. Further, by receiving a designated current from the vehicle 10 side, it is also possible to supply a current at the designated current.

  Further, in the present embodiment, when charging the battery 11 with the supply current from the external charging device 40 under conditions of extremely low temperature in a cold area or the like, the charging current of the battery 11 is limited, and the external caused by the limitation of the charging current The battery 11 is warmed up using the remaining current of the charging device 40. The details will be described below.

  FIG. 2 is a flowchart showing the processing procedure of the battery external charge, and this processing is performed by the PLG-ECU 31 when the condition for starting charging is satisfied.

  In FIG. 2, in step S <b> 11, the external supply current Ia supplied from the external charging device 40 to the vehicle 10 is set. Specifically, the smaller one of the maximum supply current defined in advance by external charging device 40 and the designated current designated by vehicle 10 is set as external supply current Ia. The designated current is, for example, a current determined by the specification of the vehicle type and the power supply system. It is also possible to set the current value designated by the user each time charging as the designated current.

  Thereafter, in step S12, it is determined whether the battery temperature is less than a predetermined value K1. The predetermined value K1 is a threshold value for determining that the battery 11 is in a predetermined low temperature state, and is 0 ° C., for example. In step S13, it is determined whether the SOC of the battery 11 is less than a predetermined value K2. The predetermined value K2 is, for example, 70%, which is a threshold value for determining that the battery 11 is in a state near full charge, that is, the required charge amount is small.

  And if both step S12 and S13 are YES, it will progress to step S14, and if either of step S12, S13 is NO, it will progress to step S16.

  In step S14, based on the battery temperature and the SOC of the battery 11, the charging limit current Ib, which is the limiting value of the charging current, is calculated to limit the charging current used for battery charging. At this time, for example, using the relationship shown in FIG. 3, the charge limiting current Ib is reduced (the current limit is increased) as the battery temperature is lower. Further, the charge limiting current Ib is reduced (the current limit is increased) as the SOC is larger.

  Note that, based on the battery temperature and the SOC of the battery 11, the limiting coefficient (= 0 to 1) for the external supply current Ia is set, and the external supply current Ia is multiplied by the limiting coefficient to calculate the charge limiting current Ib. It is also possible.

  Thereafter, in step S15, it is determined that the air conditioner 25 performs heating, and in the subsequent step S16, an air conditioner use current Ic for driving the air conditioner 25 is set. In this case, the air conditioner use current Ic is obtained by subtracting the charge limiting current Ib calculated in step S14 from the external supply current Ia set in step S11 (Ic = Ia-Ib).

  In the subsequent step S17, the operating condition of the air conditioner 25 (that is, the embodiment of heating) is set. Specifically, as the operating condition, the air conditioner set temperature and the air conditioner air volume are set. In this case, the air conditioner operating condition may be set based on the air conditioner use current Ic. For example, as the air conditioner use current Ic is larger, the air conditioner set temperature may be increased or the air conditioner air volume may be increased. In step S18, a control command for performing heating is output to the air conditioner 25.

  In step S19, it is determined whether the air conditioner 25 is heating. If heating is in progress, the process proceeds to step S20, and the driving of the air conditioner 25 is stopped.

  After the execution of steps S18 and S20, or if step S19 is NO, the process proceeds to step S21. In step S21, it is determined whether the SOC of the battery 11 has become a fully charged value, and if not fully charged, the process returns to step S12, and if fully charged, the current battery external charging is ended.

  FIG. 4 is a time chart for more specifically explaining battery charging by external charging device 40. As shown in FIG. In addition, although the conditions of an air-conditioner drive at the time of battery external charge include temperature conditions and SOC conditions, only temperature conditions are shown here for convenience of explanation.

  In FIG. 4, the power supply to the vehicle 10 by the external charging device 40 is started at timing t1. At this time, since the battery temperature is less than the predetermined value K1, the charging current of the battery 11 is limited. That is, the charging limit current Ib is calculated based on the battery temperature and the SOC of the battery 11, and the air conditioning working current Ic is calculated by subtracting the charging limit current Ib from the external supply current Ia. Then, the battery 11 is charged by the charge limiting current Ib, and the vehicle indoor heating of the air conditioner 25 is performed by the air conditioner use current Ic. At this time, the air conditioner 25 is driven by the PLG-ECU 31 in a state where the drive current of the air conditioner 25 is adjusted to the air conditioner use current Ic. As a result, charging power to battery 11 among external supply current Ia is limited to charge limiting current Ib.

  The battery temperature gradually rises due to the heating of the vehicle interior. In this case, the charging limit current Ib is gradually updated to the increase side as the battery temperature rises, and the air conditioner use current Ic gradually decreases according to the increase change of the charging limit current Ib.

  Thereafter, at timing t2, when the battery temperature reaches the predetermined value K1, the limitation of the charging current is released. In addition, the driving of the air conditioner 25 is stopped. That is, after timing t2, the external supply current Ia is supplied as it is to the battery 11 (Ib = Ia), and normal charging is performed by the external supply current Ia.

  Thereafter, the charging of the battery 11 further proceeds, and the SOC reaches the fully charged value at timing t3. Thereby, the charging of the battery 11 is completed, and the power supply of the external charging device 40 is stopped.

  According to the embodiment described above, the following excellent effects can be obtained.

  Based on the temperature of the battery 11, the charging limit current Ib to the battery 11 is set. This makes it possible to limit the charging current under extremely low temperature conditions, and to suppress the deterioration of the battery 11. Further, the battery 11 is warmed up by the heating of the air conditioner 25 using the remaining current (air conditioner use current Ic) obtained by subtracting the charge limiting current Ib from the external supply current Ia supplied from the external charging device 40 to the vehicle 10. It was made to carry out. In this case, the battery 11 can be charged without limiting the current supply capability of the external charging device 40. As a result, the external charging of the battery 11 can be appropriately performed even in a low temperature state.

  During battery charging under extremely low temperature conditions, the charge limiting current Ib is gradually increased as the battery temperature gradually rises, and the air conditioner use current Ic is gradually decreased accordingly. As a result, it is possible to properly charge and warm up the battery 11 while changing the balance between the charge limiting current Ib and the air conditioner use current Ic as the warm-up of the battery 11 progresses.

  Since the charge limit current Ib is set in consideration of the SOC in addition to the temperature of the battery 11, the charge current is limited in consideration of how much charge current needs to be supplied to the battery 11. it can.

  When the warm-up of the battery 11 is carried out, heating of the passenger compartment by the air conditioner 25 is carried out using a part of the externally supplied current Ia. In this case, the use of the air conditioner 25 eliminates the need to provide a heating device dedicated to battery warm-up. Therefore, the battery 11 can be warmed up without increasing the cost.

  Based on the size of the air conditioner use current Ic, the embodiment of heating such as the set temperature and the air volume of the air conditioner 25 is set. Therefore, it is possible to realize control such as strengthening the heating when the battery temperature is low and particularly requiring warm-up, and weakening the heating thereafter.

(Other embodiments)
The above embodiment may be modified, for example, as follows.

  In the above embodiment, the air conditioner working current Ic is calculated from the externally supplied current Ia and the charge limiting current Ib such that the relationship of “Ia = Ib + Ic” is established, but this is changed to “Ia The air conditioner use current Ic may be calculated based on the relation of> Ib + Ic.

  The configuration may be such that the charge limiting current Ib and the air conditioner use current Ic are set at the start of charging, and then remain constant until the battery temperature reaches K1 during battery external charging in a very low temperature state. In addition, after start of charging, Ib and Ic may be changed stepwise in a predetermined width.

  · During battery external charge in a very low temperature state, charge limit current Ib and air conditioner use current Ic are set at the start of charge, and thereafter, battery with charge limit current Ib in a period until a predetermined time elapses The configuration may be such that the charging restriction to 11 and the heating drive of the air conditioner 25 are performed.

  In the above embodiment, when the battery 11 is warmed up by the heating of the air conditioner 25, the embodiment of heating such as the set temperature and the air volume of the air conditioner 25 is variably set according to the air conditioner use current Ic. However, this may be changed to make the set temperature and the air volume constant (for example, the MAX value).

  The air conditioner 25 may be provided with a duct for directly supplying the heating air to the battery 11. In this case, a path for supplying the heating air to the vehicle compartment and a path for supplying the battery 11 are provided, and a path switching means is provided, and the path of the heating air is on the battery side To switch to

  The heating means may be other than the air conditioner 25 (heating means). For example, the battery 11 may be warmed up by providing the battery 11 with an electric heater and driving the electric heater with the current supplied from the external charging device 40.

  The external power supply may be configured as an AC charging device that supplies AC power to the vehicle 10. In this case, in the vehicle 10, the AC supply power from the AC charging device is AC / DC converted, and then the battery 11 is charged. Moreover, it is also possible to embody the present invention as a technology for externally charging an on-vehicle battery of an electric vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Battery (electrical storage apparatus), 25 ... Air-conditioner apparatus (heating means), 31 ... PLG-ECU (1st setting means, 2nd setting means, warm-up control means) 40: External charge apparatus (external Power supply).

Claims (4)

A vehicle comprising a chargeable and dischargeable storage device (11) and a heating means (25) for heating the storage device, wherein the storage device is charged by an external current supplied from an external power supply (40) outside the vehicle The charge control device (31) to be applied,
First setting means for setting a supply current supplied to the vehicle from the external power source;
Second setting means for setting a charging current to the power storage device based on the temperature of the power storage device and the storage amount of the power storage device;
Warm-up control means for performing warm-up of the power storage device by heating of the heating means using the residual current obtained by subtracting the charging current set by the second setting means from the supply current set by the first setting means When,
Equipped with
A charge control device for a vehicle, wherein the second setting means reduces the charge current as the temperature of the power storage device is lower, and reduces the charge current as the storage amount of the power storage device is larger .   2. The charge control device for a vehicle according to claim 1, wherein the second setting unit increases the charge current according to the temperature rise of the power storage device after the start of charging of the power storage device. The present invention is applied to a vehicle provided with heating means (25) driven by supply of electric power to heat the vehicle interior, and the power storage device is provided in the vehicle interior or in the vicinity of the vehicle interior,
The charge control device for a vehicle according to claim 1 or 2 , wherein the warm-up control means uses the heating means as the heating means, and performs heating of the heating means by the residual current. The charge control device for a vehicle according to claim 3 , wherein the warm-up control means sets an embodiment of heating by the heating means based on a magnitude of the residual current.

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