JP2016111721A - Charge control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform external charging of a power storage device properly even in a low-temperature state.SOLUTION: A vehicle 10 comprises a battery 11 that can be charged and discharged, and an air conditioner 25 for heating inside a cabin. The battery 11 is charged by an external current supplied from an external charging device 40 outside the vehicle. A PLG-ECU 31 comprises: first setting means for setting an external supply current supplied from the external charging device 40 to the vehicle 10; second setting means for setting a charging limit current to the battery 11 based on the temperature of the battery 11; and heating control means for heating the battery 11 by heating of the drive of the air conditioner 25 using a residual current obtained by subtracting the charging limit current from the external supply current.SELECTED DRAWING: Figure 1

Description

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

  A technology for mounting a power storage device (battery) made of a secondary battery or the like on a vehicle and charging the power storage device with an external charging device outside the vehicle has been put into practical use. In addition, when charging a battery in a cold region or the like under extremely low temperature conditions, there is a concern about inconveniences such as a large charging loss and prolonged charging time because the internal resistance of the battery is high. Therefore, a technique for warming up the battery during battery charging under extremely low temperature conditions has been proposed.

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

JP 2010-110196 A

  However, in the above conventional technique, there is a concern that the battery will deteriorate due to the rapid charging of the battery at an extremely low temperature. For example, in a lithium ion battery, there is a concern that lithium is deposited on the negative electrode surface and deterioration (decrease in capacity) is promoted by continuing charging with a large current under extremely low temperature conditions. Therefore, it is desirable to limit (squeeze) the charging current of the battery at extremely low temperatures.

  However, if the charging current is limited under extremely low temperature conditions, the current supply capability of the external charging device is limited. For this reason, it is considered that the efficiency is lowered when current is supplied from the external charging device.

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

  A vehicle charge control device according to the present invention includes a chargeable / 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. The present invention is applied to a vehicle that charges the power storage device. A first setting unit configured to set a supply current supplied to the vehicle from the external power source; a second setting unit configured to set a charging current to the power storage device based on a temperature of the power storage device; A 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 a charging current set by the second setting means from a supply current set by one setting means; It is characterized by providing.

  According to the above configuration, the charging current to the power storage device is set based on the temperature of the power storage device. Thereby, the charging current can be limited under extremely low temperature conditions, and deterioration of the power storage device can be suppressed. Further, the power storage device is warmed up by heating of the heating means, using the remaining current obtained by subtracting the charging current for the power storage device from the supply current supplied to the vehicle from the external power source. In this case, the remaining current of the external power supply due to the limitation of the charging current to the power storage device is effectively used for warming up the power storage device, so that the current supply capability of the external power supply is less likely to be limited. The device can be charged. As a result, it is possible to appropriately perform external charging of the power storage device even in a low temperature state.

The schematic block diagram which shows the whole charging system of a vehicle. The flowchart which shows the process sequence of battery external charge. The figure which shows the relationship between battery temperature, SOC, and a charge limiting current. The time chart for demonstrating a battery external charge more concretely.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment embodying a charge control device of the present invention will be described with reference to the drawings. In the present embodiment, a configuration in which a vehicle-mounted battery is charged with external power in a hybrid vehicle including an engine and an electric motor as a driving power source is illustrated, and FIG. 1 shows a schematic configuration thereof. However, FIG. 1 mainly shows the configuration of a battery and a motor generator driven by 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), a battery monitoring unit 15, SMR16 (System Main Relay). The battery 11 is composed of a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The output voltage of the battery 11 is about 200V. Note that the power storage device can 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 passenger compartment or in the vicinity of the passenger compartment. Specifically, the battery 11 is provided in the lower part of the seat, the lower part of the floor, the rear cargo bed part, etc. in the passenger compartment.

  The PCU 12 includes a DCDC converter 21 and an inverter 22 that convert stored power of the battery 11 into driving power of the motor generator 13, and an MG-ECU 23 that controls driving of the inverter 22. The motor generator 13 is constituted by, 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. When the vehicle 10 is braked, the motor generator 13 generates regenerative power, and the battery 11 is charged with the generated power.

  The PM-ECU 14 and the MG-ECU 23 include a well-known electronic control unit having a CPU and a memory, and perform various arithmetic processes based on programs, maps, and the like stored in the memory. These ECUs 14 and 23 and a PLG-ECU 31 to be described later are connected via a communication line so that various types of information can be communicated with each other.

  The battery monitoring unit 15 monitors the state (voltage, current, temperature, etc.) of the battery 11 with 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 a battery temperature detection result from 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 a required driving force in the vehicle 10 based on a vehicle operation or a vehicle state by the driver, and outputs a control command calculated based on the required driving force to the MG-ECU 23. . The MG-ECU 23 controls driving of the motor generator 13 based on a control command from the PM-ECU 14. Specifically, the inverter 22 is controlled so that the output torque of the motor generator 13 matches the torque command value. Further, the PM-ECU 14 calculates an SOC (State of Charge) 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 on / off (open / close) of each relay circuit is controlled by the PM-ECU 14. When SMR is off, battery 11 and PCU 12 are electrically disconnected, and when SMR is on, battery 11 and PCU 12 are electrically connected.

  The vehicle 10 also includes an air conditioner 25 that performs air conditioning (heating and cooling) in the passenger compartment. The air conditioner device 25 corresponds to a heating unit that is driven by the supply of electric power and performs heating of the passenger compartment. 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 interior or in the vicinity of the vehicle interior. When the vehicle interior is heated by the air conditioner 25, the battery 11 can be warmed up (heated) by the heat of the heating. It has become.

  The battery 11 of the vehicle 10 can be charged by an external charging device 40 as an external power source. The vehicle 10 includes 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. The battery 11 is charged by the external charging device 40 in a state where the external charging device 40 is connected to the inlet 34 by the charging cable. In a state where 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 information on the external charging device 40 side can be obtained on the PLG-ECU 31 side. .

  The PLG-ECU 31 includes a well-known electronic control unit having a CPU and a memory, like 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 PM-ECU 14 is turned on by the PM-ECU 14 when the charging relay 32 is turned on, so that a charging path from the external charging device 40 to the battery 11 is opened. Charging is performed.

  Further, the PLG-ECU 31 has a function of controlling the driving of the air conditioner device 25, and heats the air conditioner device 25 when battery external charging is performed in a very low temperature state of the battery 11 (for example, less than 0 ° C.). I am trying to do it.

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

  Further, in the present embodiment, when charging the battery 11 with a supply current from the external charging device 40 in a cold region or the like in a cold region or the like, the charging current of the battery 11 is limited and the external generated due to the limitation of the charging current. The remaining current of the charging device 40 is used to warm up the battery 11. Details will be described below.

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

  In FIG. 2, in step S11, an 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 specified in advance in the external charging device 40 and the specified current specified on the vehicle 10 side is set as the external supply current Ia. The designated current is a current determined by, for example, the specifications of the vehicle type and the power supply system. It is also possible to set the current value designated by the user each time the battery is charged as the designated current.

  Thereafter, in step S12, it is determined whether or not the battery temperature is lower 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 a threshold value for determining that the battery 11 is close to a fully charged state, that is, that the required charge amount is very small, and is 70%, for example.

  If both of steps S12 and S13 are YES, the process proceeds to step S14, and if any of steps S12 and S13 is NO, the process proceeds to step S16.

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

  Based on the battery temperature and the SOC of the battery 11, a limit coefficient (= 0 to 1) for the external supply current Ia is set, and the charge limit current Ib is calculated by multiplying the external supply current Ia by the limit coefficient. It is also possible to do.

  Thereafter, in step S15, it is determined that heating by the air conditioner device 25 is to be performed, and in the subsequent step S16, an air conditioner use current Ic for driving the air conditioner device 25 is set. In this case, the air-conditioner use current Ic is obtained by subtracting the charging limit 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 device 25 (that is, the heating mode) is set. Specifically, an air conditioner set temperature and an air conditioner air volume are set as operating conditions. In this case, the air conditioner operating condition may be set based on the air conditioner use current Ic. For example, the larger the air conditioner use current Ic, the higher the air conditioner set temperature or the air conditioner air volume. 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 it is during heating, it will progress to Step S20 and will stop drive of air-conditioner device 25.

  After performing Steps S18 and S20, or when Step S19 is NO, the process proceeds to Step S21. In step S21, it is determined whether or not the SOC of the battery 11 has reached a fully charged value. If not fully charged, the process returns to step S12. If fully charged, the current external charging of the battery is terminated.

  FIG. 4 is a time chart for more specifically explaining battery charging by the external charging device 40. Note that there are a temperature condition and an SOC condition as conditions for driving the air conditioner during external charging of the battery, but only the temperature condition is shown here for convenience of explanation.

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

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

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

  Thereafter, charging of the battery 11 further proceeds, and the SOC reaches a 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 in detail above, the following excellent effects can be obtained.

  Based on the temperature of the battery 11, the charge limiting current Ib to the battery 11 is set. As a result, the charging current can be limited under extremely low temperature conditions, and deterioration of the battery 11 can be suppressed. Further, the battery 11 is warmed up by heating of the air conditioner 25 using the remaining current (air conditioner current Ic) obtained by subtracting the charging limit current Ib from the external supply current Ia supplied from the external charger 40 to the vehicle 10. I tried to do it. 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 battery 11 can be appropriately externally charged even in a low temperature state.

  When charging the battery under extremely low temperature conditions, the charging limit current Ib is gradually increased as the battery temperature gradually increases, and the air-conditioner use current Ic is gradually decreased accordingly. Thereby, the battery 11 can be appropriately charged and warmed up while changing the balance between the charge limiting current Ib and the air conditioner use current Ic as the battery 11 warms up.

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

  When the battery 11 is warmed up, the vehicle interior is heated by the air conditioner 25 using a part of the external supply current Ia. In this case, by using the air conditioner device 25, there is no need to provide a heating device dedicated to warming up the battery. Therefore, the battery 11 can be warmed up without increasing the cost.

  Based on the magnitude | size of the air-conditioner use electric current Ic, it was set as the structure which sets the embodiment of heating, such as preset temperature of the air-conditioner apparatus 25, and an air volume. Therefore, when the battery temperature is low and the warm-up is particularly necessary, it is possible to realize control such that heating is strengthened and thereafter heating is weakened.

(Other embodiments)
You may change the said embodiment as follows, for example.

  In the above embodiment, the air conditioner use current Ic is calculated from the external supply current Ia and the charge limiting current Ib so that the relationship of “Ia = Ib + Ic” is established, but this is changed to “Ia The air conditioner use current Ic may be calculated so that “> Ib + Ic” is established.

  -At the time of external charging of the battery in an extremely low temperature state, the charging limit current Ib and the air-conditioner use current Ic may be set at the start of charging, and thereafter may be kept constant until the battery temperature reaches K1. Moreover, the structure which changes Ib and Ic in steps with predetermined width after charge start may be sufficient.

  When the battery is externally charged in an extremely low temperature state, the battery with the charge limiting current Ib is set in a period until a predetermined time elapses after the charge limiting current Ib and the air conditioner use current Ic are set at the start of charging. 11 may be configured to perform charging limitation to the air conditioner 11 and heating driving of the air conditioner device 25.

  In the above embodiment, when the battery 11 is warmed up by the heating of the air conditioner 25, the heating embodiment 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).

  In the air conditioner 25, a duct that directly supplies the heating air to the battery 11 may be provided. In this case, a path for supplying the heating air into the vehicle interior and a path for supplying the battery 11 are provided, and a path switching unit is provided. When charging the battery outside in the extremely low temperature state, the path of the heating air is connected to the battery side. To switch to.

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

  The external power source may be configured as an AC charging device that supplies AC power to the vehicle 10. In this case, the vehicle 10 charges the battery 11 after AC / DC conversion is performed on the AC power supplied from the AC charging device. Further, the present invention can be embodied as a technique for externally charging an on-vehicle battery of an electric vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Battery (power storage device), 25 ... Air conditioner device (heating means), 31 ... PLG-ECU (first setting means, second setting means, warm-up control means), 40 ... External charging device (external) Power supply).

Claims (5)

A vehicle that includes a chargeable / dischargeable power storage device (11) and heating means (25) for heating the power storage device, and that charges the power storage device with an external current supplied from an external power source (40) outside the vehicle. A 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;
A 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 first setting means When,
A vehicle charge control device comprising:   2. The vehicle charging control device according to claim 1, wherein the second setting unit increases the charging current in accordance with a temperature rise of the power storage device after starting charging of the power storage device. A determination means for determining a power storage state of the power storage device;
The vehicle charging control device according to claim 1, wherein the second setting unit sets the charging current based on a temperature of the power storage device and a determination result of a power storage state. A heating means (25) that is driven by the supply of electric power to perform heating of the passenger compartment, and is applied to a vehicle in which the power storage device is provided in the passenger compartment or in the vicinity of the passenger compartment;
4. The vehicle charge control device according to claim 1, wherein the warm-up control unit uses the heating unit as the heating unit and performs heating of the heating unit by the residual current. 5.   5. The vehicle charging control device according to claim 4, wherein the warm-up control means sets an embodiment of heating by the heating means based on the magnitude of the residual current.

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