Electric vehicle and battery temperature control method

Abstract

This reduces the electricity costs required to raise the temperature of batteries installed in electric vehicles. [Solution] The battery mounted on the electric vehicle is heated by an electric heater. The planning unit 320 of the ECU 300 creates a heating plan HP from the time the battery charging is completed until the scheduled start time Dt of driving. The charging energy charge unit price calculation unit 323 calculates the charging energy charge unit price Cup, which is the unit price of the electricity used for this charging. The heating plan HP is designed so that when the energy charge unit price Eup of the external power source is higher than the charging energy charge unit price Cup, the battery power is supplied to the electric heater, and when the energy charge unit price Eup is less than or equal to the charging energy charge unit price Cup, the power from the external power source is supplied to the electric heater. The power control unit 330 supplies power to the electric heater based on the heating plan HP.

Description

Technical Field

[0001] The present disclosure relates to an electric vehicle and a method for controlling the temperature of a storage battery, and particularly to an electric vehicle equipped with a storage battery that can be charged from an external power source.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2016-201321 (Patent Document 1) discloses a temperature raising device for a battery mounted on an electric vehicle. This electric vehicle can be connected to an external power source. The temperature raising device controls an electric heater so that the temperature of the battery is not lower than a first lower limit temperature until a first predetermined period elapses after starting external charging of the battery, and controls the electric heater so that the temperature of the battery is not lower than a second lower limit temperature after the first predetermined period has elapsed. The second lower limit temperature is lower than the first lower limit temperature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a temperature raising device that uses electric power, such as an electric heater, an electricity bill is generated according to the amount of electric power of the external power source used. Patent Document 1 does not mention the electricity bill.

[0005] An object of the present disclosure is to suppress the electricity bill required to raise the temperature of a storage battery mounted on an electric vehicle.

Means for Solving the Problems

[0006] The electric vehicle of this disclosure is an electric vehicle equipped with a battery that can be charged by power supplied from an external power source, and comprises a heating device that uses electricity to raise the temperature of the battery, and a control device that controls the heating device. The control device includes a planning unit that creates a heating plan from the end of charging to the scheduled start time of driving so that the temperature of the battery reaches a predetermined temperature at the scheduled start time of driving of the electric vehicle, and a power control unit that controls the power supplied to the heating device based on the heating plan. The planning unit calculates the unit price of the electricity charges used for this charging, and creates a heating plan so that the battery's power is used during times when the unit price of the electricity charges of the external power source is higher than the heating energy charge unit price, and the power of the external power source is used during times when the unit price of the electricity charges of the external power source is less than or equal to the heating energy charge unit price.

[0007] In this configuration, the control unit's planning unit creates a temperature rise plan from the end of charging to the scheduled start time of the electric vehicle's operation, so that the battery temperature reaches a predetermined temperature by the scheduled start time of the electric vehicle's operation. The power control unit then controls the power supplied to the heating device based on the temperature rise plan. Since the battery temperature has reached the predetermined temperature at the start of operation, the electric vehicle can perform at a good level.

[0008] The heating plan calculates the electricity charge rate for the current charge, and is designed to use the battery's power during periods when the electricity charge rate for the external power source is higher than the heating charge rate, and to use the external power source when the electricity charge rate is lower than or equal to the heating charge rate. As a result, the power control unit supplies power from the battery to the heating device during periods when the electricity charge rate for the external power source is higher than the heating charge rate, thereby reducing the electricity costs required for heating.

[0009] Preferably, the power control unit may supply power from an external power source to the heating device when the State of Charge (SOC) of the storage battery is below a predetermined value.

[0010] With this configuration, the State of Charge (SOC) of the battery does not fall below a predetermined value when the electric vehicle starts running, thus suppressing the decrease in the amount of electricity used during operation.

[0011] The temperature control method for a battery of this disclosure is a temperature control method for a battery mounted on a vehicle, which can be charged from an external power source and is heated by a heating device. The heating device uses electricity to heat the battery. The temperature control method includes obtaining the scheduled start time of driving of the electric vehicle, obtaining the target temperature of the battery at the scheduled start time of driving, obtaining the electricity charge for the amount of electricity charged from the start to the end of charging from the external power source, obtaining the electricity charge unit price for the external power source, calculating the electricity charge unit price for the amount of electricity charged based on the electricity charge, creating a heating plan from the end of charging to the scheduled start time of driving so that the temperature of the battery reaches the target temperature at the scheduled start time of driving, and controlling the heating device based on the heating plan. The heating plan is created so that during times when the electricity charge unit price for the external power source is higher than the electricity charge unit price for charging, power from the battery is supplied to the heating device, and during times when the electricity charge unit price is less than or equal to the electricity charge unit price for charging, power from the external power source is supplied to the heating device.

[0012] This method creates a temperature rise plan from the end of charging to the scheduled start time of driving so that the battery temperature reaches the target temperature by the scheduled start time of driving of the electric vehicle. This method obtains the electricity charge for the amount of electricity used to charge from the start to the end of charging from an external power source, and calculates the electricity charge per unit based on this electricity charge. Then, when supplying power to the heating device based on the temperature rise plan, this method uses the battery's power during times when the electricity charge per unit of the external power source is higher than the electricity charge per unit of driving, and uses the external power source's power during times when the electricity charge per unit is lower than or equal to the electricity charge per unit of driving.

[0013] In this method, during periods when the electricity rate for external power is higher than the electricity rate for charging, power from the battery is supplied to the heating device to raise the battery's temperature, thereby reducing the electricity costs required for heating.

[0014] Preferably, the temperature control method further includes obtaining the State of Charge (SOC) of the storage battery, and if the SOC is below a predetermined value, power from an external power source may be supplied to the heating device even during the time when power from the storage battery is supplied to the heating device.

[0015] This method ensures that the State of Charge (SOC) of the battery does not fall below a predetermined value when the electric vehicle starts running, thereby suppressing the decrease in the amount of electricity used during operation. [Effects of the Invention]

[0016] According to this disclosure, it is possible to reduce the electricity costs required to raise the temperature of the battery installed in an electric vehicle. [Brief explanation of the drawing]

[0017] [Figure 1] This is an overall configuration diagram of the electric vehicle according to this embodiment. [Figure 2] This flowchart shows an example of plug-in temperature rise control performed by the ECU in this embodiment. [Figure 3] This figure shows an example of a functional block configured in an ECU. [Modes for carrying out the invention]

[0018] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0019] FIG. 1 is an overall configuration diagram of an electric vehicle 1 according to the present embodiment. In the present embodiment, the electric vehicle 1 is, for example, a battery electric vehicle (BEV). The electric vehicle 1 includes a motor generator (MG) 10 which is a rotary electric machine, a power transmission gear 20, drive wheels 30, a power control unit (PCU) 40, a system main relay (SMR) 50, a battery 100, a monitoring unit 200, and an electronic control unit (ECU) 300 which is an example of a control device.

[0020] MG10 is, for example, an embedded structure permanent magnet synchronous motor (IPM motor), and has functions as a motor and as a generator. The output torque of MG10 is transmitted to the drive wheels 30 via a power transmission gear 20 configured to include a reduction gear, a differential device, and the like.

[0021] During braking of the electric vehicle 1, MG10 is driven by the drive wheels 30, and MG10 operates as a generator. Thereby, MG10 also functions as a braking device that performs regenerative braking to convert the kinetic energy of the electric vehicle 1 into electric power. The regenerative power generated by the regenerative braking force in MG10 is stored in the battery 100.

[0022] PCU40 is a power conversion device that converts power bidirectionally between MG10 and the battery 100. PCU40 includes, for example, an inverter and a converter that operate based on a control signal from ECU300. PCU40 may have a configuration in which the converter is omitted.

[0023] The SMR50 is electrically connected to the power line connecting the battery 100 and the PCU40. When the SMR50 is closed (ON) in response to a control signal from the ECU300 (in a conductive state), power can be transferred between the battery 100 and the PCU40. On the other hand, when the SMR50 is opened (OFF) in response to a control signal from the ECU300 (in a cut-off state), the electrical connection between the battery 100 and the PCU40 is cut off.

[0024] The battery 100 stores power for driving the MG10. The battery 100 is a rechargeable DC power source (secondary battery), and a plurality of single cells (battery cells) are stacked and configured, for example, to be electrically connected in series. The battery 100 corresponds to a storage battery. The single cell is composed of, for example, a lithium-ion battery. The single cell may be a nickel-metal hydride battery or may be a all-solid-state battery. Note that the battery 100 corresponds to the "storage battery" of the present disclosure.

[0025] [[ID=⑧]]The monitoring unit 200 includes a voltage detection unit, a current sensor, and a temperature detection unit. The voltage detection unit detects the voltage VB of the battery. The current sensor detects the current IB input to and output from the battery 100. The temperature detection unit detects the temperature TB of the battery 100. Each detection unit outputs its detection result to the ECU300.

[0026] The electric vehicle 1 is equipped with an AC inlet 80, and the battery 100 can be charged (externally charged) from an EVSE (charging equipment) 500 that supplies power from an external AC power source 2 to the electric vehicle 1. The AC inlet 80 is configured to be connectable to a connector 520 provided at the end of the charging cable 510 of the EVSE 500. An onboard charger 130 is provided in the power line between the AC inlet 80 and the battery 100, which converts the AC power supplied from the external AC power source into DC power and also converts it to a voltage that can charge the battery 100. The charging relay 90 is electrically connected to the power line connecting the onboard charger 130 and the battery 100. The charging relay 90 switches between supplying and cutting off power between the onboard charger 130 and the battery 100 in response to a control signal from the ECU 300. When the charging relay 90 is closed and the SMR 50 is closed, external charging (normal charging) of the battery 100 is performed. The EVSE500 may be a type that has a control circuit built into it. The EVSE500 may also be an outlet that outputs an external AC power supply 2, and the charging cable 510 may have a built-in control circuit. External charging may also be performed by charging the battery 100 using an EVSE that outputs DC power.

[0027] External AC power supply 2 corresponds to the “external power supply” in this disclosure. In this embodiment, external AC power supply 2 is a commercial power supply, and the electricity rate per kWh [¥ / kWh] fluctuates depending on the time of day, weekdays / holidays, season, etc.

[0028] The ECU 300 includes a CPU (Central Processing Unit) 301, a memory (including, for example, ROM (Read Only Memory) and RAM (Random Access Memory)) 302, and a communication unit 303. Based on signals received from the monitoring unit 200, signals from various sensors (not shown) (for example, accelerator opening signal, vehicle speed signal, etc.), and information such as maps and programs stored in the memory 302, the ECU 300 controls each device so that the electric vehicle 1 reaches a desired state. The ECU 300 calculates the SOC (State of Charge) of the battery 100 based on voltage VB, current IB, etc. The ECU 300 also controls the temperature control device 800, which will be described later. The communication unit 303 includes a communication I / F (interface) for wireless communication with the network NW and user terminal 3. The communication unit 303 may also include a TCU (Telematics Control Unit) and / or a DCM (Data Communication Module) for wireless communication.

[0029] The HMI (Human Machine Interface) device 600 includes an input device and a display device. The HMI device 600 includes a touch panel display that functions as both an input device and a display device.

[0030] The user terminal 3 is configured to be portable by the user. The user terminal is a mobile terminal carried and operated by the user (vehicle manager) of the electric vehicle 1. In this embodiment, a smartphone equipped with a touch panel display is used as the user terminal 3. However, any terminal that can be carried by the user of the electric vehicle 1 can be used as the user terminal 3. For example, a laptop, tablet, portable game console, or wearable device (smartwatch, smart glasses, smart gloves, etc.) can also be used as the user terminal 3. The user terminal 3 can communicate with the communication unit 303, for example, by short-range wireless communication, and can also communicate with the external server 5 via the network NW.

[0031] The external server 5 is configured to communicate with the electric vehicle 1 (communication unit 303) and the user terminal 3 via the network NW. The external server 5 provides weather information around the electric vehicle 1, electricity rate information for the external AC power supply (commercial power supply), etc., via the network NW.

[0032] The electric vehicle 1 is equipped with a temperature control device 800. The temperature control device 800 adjusts the temperature of the battery 100 and corresponds to an example of a "heating device" in this disclosure. The temperature control device 800 consists of a battery cooling unit (battery cooling system) 801 and a battery heating unit (battery heating system) 802. The temperature control device 800 includes, for example, a battery thermal circuit through which a heat transfer medium that exchanges heat with the battery 100 circulates. The battery cooling unit 801 may employ a configuration that cools the heat transfer medium circulating in the battery thermal circuit using a chiller cooled by a refrigeration cycle device that is also used for indoor air conditioning, thereby cooling the battery 100. The battery heating unit 802 may, for example, heat the heat transfer medium circulating in the battery thermal circuit with an electric heater 810 to raise the temperature of the battery 100. The battery heating unit 802 may also directly heat the battery 100 with the electric heater 810.

[0033] The electric heater 810 is supplied with power from an external AC power source 2 (EVSE500) and power stored in the battery 100. When the connector 520 is connected to the AC inlet 80 (hereinafter referred to as the "plug-in state"), and the charging relay 90 is closed and the SMR 50 is open, activating the electric heater 810 supplies power from the external AC power source 2 to the electric heater 810, causing the battery 100 to heat up. When the plug-in state is in place, and the charging relay 90 is open and the SMR 50 is closed, activating the electric heater 810 supplies power from the battery 100 to the electric heater 810, causing the battery 100 to heat up.

[0034] Figure 2 is a flowchart showing an example of plug-in temperature rise control performed by the ECU 300 in this embodiment. This flowchart shows that the process starts when the connector 520 is connected to the AC inlet 80.

[0035] In step 10 (hereinafter, steps are abbreviated as "S"), the ECU 300 determines whether or not charging (external charging) of the battery 100 is complete. For example, charging of the battery 100 is complete when the battery 100 is fully charged, or when the State of Charge (SOC) of the battery 100 reaches a value set by the user (for example, 90%). If charging of the battery 100 is not complete, S10 is repeated until charging of the battery 100 is complete. When charging of the battery 100 is complete, S10 is affirmed and the process proceeds to S11. During charging of the battery 100, the SMR 50 and charging relay 90 are closed, and power from the external AC power supply 2 is supplied to the battery 100. When charging of the battery 100 is complete, the SMR 50 and charging relay 90 are opened, and the power supply to the battery 100 is cut off.

[0036] In S11, the ECU300 obtains the charging energy amount CA [kWh] and the charging electricity cost Cc [¥ / kWh]. The charging energy amount CA is the amount of energy used for this charge, and may be calculated and obtained, for example, from the SOC at the start of charging and the SOC at the end of charging. Alternatively, the charging energy amount CA may be calculated and obtained by integrating the current IB (corresponding to the charging current) from the start of charging to the end of charging.

[0037] The charging electricity cost Cc is the electricity cost incurred for this charging. The charging electricity cost Cc is calculated using the electricity rate Eup [¥ / kWh] of the external power source for each time period from the start to the end of charging, and the amount of electricity [kWh] supplied to battery 100 during each time period. The electricity rate Eup may be obtained from the external server 5. For example, if a kWh of electricity is used during the time period when the electricity rate Eup is A [¥ / kWh], b kWh of electricity is used during the time period when the electricity rate Eup is B [¥ / kWh], and c kWh of electricity is used during the time period when the electricity rate Eup is C [¥ / kWh], and charging is completed, then the charging electricity CA will be CA = a + b + c. The charging electricity cost Cc is calculated and obtained as "Cc = (A × a) + (B × b) + (C × c)".

[0038] In the following S12, the charging energy charge unit price Cup [¥ / kWh] is calculated. The charging energy charge unit price Cup is the unit price of the electricity used for this charge, and is the value obtained by dividing the charging electricity charge Cc by the amount of energy charged CA. In the example above, it is calculated as "Cup = Cc / CA = ((A × a) + (B × b) + (C × c)) / (a ​​+ b + c)".

[0039] In S13, the ECU 300 obtains the scheduled start time Dt, target temperature Ttb, electricity rate unit price Eup, outside temperature information Te, and temperature TB. The scheduled start time Dt is the time when the user starts driving the electric vehicle 1, and is set, for example, by the user inputting it into the HMI device 600. Alternatively, the user may set the scheduled start time Dt by operating the user terminal 3. Or, the ECU 300 may estimate the scheduled start time Dt from past performance based on the season, day of the week, etc. In this case, the scheduled start time Dt may be estimated using a machine learning model.

[0040] The target temperature Ttb is the target temperature of the battery 100 at the scheduled start time Dt of driving, and corresponds to an example of the "predetermined temperature" in this disclosure. The target temperature Ttb is set according to the characteristics of the battery 100, etc., and is preset as the temperature at which the battery 100's functions (charging and discharging) can be performed well. In this embodiment, the target temperature Ttb is set to 25°C. The target temperature Ttb may be corrected according to the State of Health (SOH) of the battery 100.

[0041] The electricity rate Eup is the rate [¥ / kWh] from the current time (when charging is complete) until the scheduled start time Dt of driving. Generally, the electricity rate Eup is set according to the time of day, weekdays / holidays, season, etc. For example, the electricity rate Eup is lower during nighttime hours. The electricity rate Eup is obtained from an external server 5.

[0042] The ambient temperature information Te indicates the change in ambient temperature around the electric vehicle 1 from the present time until the scheduled start time Dt. The ambient temperature information Te is included in the weather information received from the external server 5. The temperature TB is the current temperature of the battery 100. When the battery 100 is charged, the temperature TB of the battery 100 is controlled by the temperature control device 800 to a temperature suitable for charging. Therefore, the temperature TB acquired in S13 does not deviate significantly from the target temperature Ttb.

[0043] In S14, the ECU300 creates a temperature rise plan. The temperature rise plan is a power supply schedule (energy supply schedule) for the electric heater 810, and is created so that the temperature TB of the battery 100 reaches the target temperature Ttb at the scheduled start time Dt of driving. For example, based on the current temperature TB and the change in ambient temperature from the present to the scheduled start time Dt of driving, the temperature TB at the scheduled start time Dt of driving if the battery 100 is not heated is estimated. This estimated temperature TB is called the default temperature TBn. If the default temperature TBn is lower than the target temperature Ttb, the electric heater 810 is energized, and the battery 100 is heated by the temperature control device 800, creating an energy supply schedule so that the temperature TB of the battery 100 reaches the target temperature Ttb at the scheduled start time Dt of driving. If the default temperature TBn is higher than the target temperature Ttb, the process proceeds to S15 without creating a temperature rise plan (energy supply schedule).

[0044] The heating plan is a power supply schedule that includes the power supplied to the electric heater 810, the power supply period (start and end times), and the power source for the electric heater 810. For example, based on the current temperature TB and the change in ambient temperature from the present to the planned start time Dt, the amount of heat dissipated by the battery 100 is estimated, and the power supply start and end times (power supply period) and power supply are calculated from the amount of heating required for the temperature TB to reach the target temperature Ttb by the planned start time Dt. The power supply period and power supply may be calculated in such a way that the amount of power supplied to the electric heater 810 is minimized.

[0045] Once the ECU300 determines the power supply and energizing time in the heating plan, it selects the power source for the electric heater 810. The ECU300 selects battery 100 as the power source for the electric heater 810 during energizing time when the electricity rate per unit Eup is higher than the charging electricity rate per unit Cup. The CCU300 selects external AC power supply 2 as the power source for the electric heater 810 during energizing time when the electricity rate per unit Eup is less than or equal to the charging electricity rate per unit Cup. In this way, the ECU300 creates a heating plan that includes the power supply to the electric heater 810, the energizing time (start and end times), and the power source for the electric heater 810.

[0046] In the following step S15, the ECU300 determines whether or not it is necessary to raise the temperature of battery 100. If no temperature raising plan is created in S14, it is determined that raising the temperature of battery 100 is unnecessary, so the determination is affirmative and this routine ends. If a temperature raising plan is created in S14, the determination is negative, and the process proceeds to S16.

[0047] In S16, the ECU 300 supplies power to the electric heater 810 and executes temperature control according to the temperature rise plan created in S14. When the power supply start time of the temperature rise plan arrives, the ECU 300 supplies power to the electric heater 810. The amount of power supplied to the electric heater 810 may be adjusted, for example, by a DC-DC converter (not shown). During the power supply period in which the external AC power supply 2 is selected as the power source in the temperature rise plan, the SMR 50 is opened and the charging relay 90 is closed to supply power from the external AC power supply 2 to the electric heater 810. During the power supply period in which the battery 100 is selected as the power source in the temperature rise plan, the SMR is opened and the charging relay 90 is opened to supply power from the battery 100 to the electric heater 810.

[0048] In S17, the ECU300 determines whether the current time is the scheduled start time Dt. If the current time is the scheduled start time Dt, the determination in S17 is affirmative, and the process proceeds to S21. If the current time is before the scheduled start time Dt, the determination is negative, and the process proceeds to S18.

[0049] In S18, the ECU 300 determines whether the State of Charge (SOC) of the battery 100 is less than or equal to a predetermined value A. The predetermined value A may be a value that has been set in advance as the value at which the electric vehicle 1 can run sufficiently using the power of the battery 100. The predetermined value A may be set by the user by operating the HMI device 600. If the State of Charge (SCO) is greater than the predetermined value A, the determination is negative and the process returns to S16, and power from the external AC power supply 2 is supplied to the electric heater 810 according to the temperature rise plan. If the SOC is less than or equal to the predetermined value A, the determination is positive and the process proceeds to S19.

[0050] In S19, the ECU300 switches the power supply for the electric heater 810 to the external AC power supply 2 and continues the temperature rise control. The ECU300 opens the SMR50 and closes the charging relay 90. As a result, even during the power supply period when the battery 100 is selected as the power source, power from the external AC power supply 2 is supplied to the electric heater 810.

[0051] In the following step S20, the ECU300 determines whether the current time is the scheduled start time Dt. If the current time is the scheduled start time Dt, the determination in S20 is affirmative, and the process proceeds to S21. If the current time is before the scheduled start time Dt, the determination is negative, and the process returns to S19, where the process of S19 is repeated.

[0052] In S21, ECU300 terminates the current routine after finishing the temperature rise control.

[0053] Figure 3 shows an example of a functional block configured in the ECU300. As shown in Figure 3, the ECU300 receives battery voltage VB, current IB, and temperature TB from the monitoring unit 200. The scheduled start time Dt for driving is input to the ECU300 from the HMI device 600 and user terminal 3. The ECU300 receives the electricity rate unit price Eup and outside temperature information Te from the external server 5 via the network NW.

[0054] The SOC calculation unit 310 calculates the SOC of the battery 100 based on the voltage VB, current IB, etc. The planning unit 320 creates a temperature rise plan HP. The planning unit 320 includes a charging energy amount calculation unit 321, a charging electricity cost calculation unit 322, a charging energy cost unit price calculation unit 323, a driving start time acquisition unit 324, and a target temperature acquisition unit 325.

[0055] As explained in S12 (Figure 2), the charging energy amount calculation unit 321 calculates the charging energy amount CA from, for example, the SOC at the start of charging and the SOC at the end of charging. The charging electricity charge calculation unit 322 uses the electricity charge unit price Eup of the external power source for each time period from the start of charging to the end of charging, the amount of energy supplied to the battery 100 during charging, etc., to calculate the charging electricity charge Cc, which is the electricity charge required for this charging, as explained in S12. The charging energy charge unit price calculation unit 323 calculates the charging energy charge unit price Cup by dividing the charging electricity charge Cc by the charging energy amount CA.

[0056] The scheduled start time acquisition unit 324 acquires the scheduled start time Dt input by the ECU 300 from the HMI device 600 or the user terminal 3. Alternatively, the scheduled start time acquisition unit 324 may use a learned model to estimate the scheduled start time Dt from past performance based on the season, day of the week, etc. The target temperature acquisition unit 325 reads the target temperature Ttb stored in the memory 302. The target temperature acquisition unit 325 may correct the read target temperature Ttb according to the SOH of the battery 100.

[0057] As described in S14, the planning unit 320 creates a temperature rise plan HP based on the scheduled start time Dt, the current temperature TB of the battery 100, ambient temperature information Te, target temperature Ttb, energy charge unit price Eup, and charging energy charge unit price Cup. The temperature rise plan HP is an energization schedule that includes the power supplied to the electric heater 810, the energization period (energency start time and energization end time), and the power source for the electric heater 810.

[0058] The power control unit 330 controls the energization (power supply) of the electric heater 810 as described in S16 to S21, based on the temperature rise plan HP created by the planning unit 320 and the state of charge (SOC) of the battery 100.

[0059] According to this embodiment, the electric vehicle 1 is equipped with a battery 100 that is externally charged by power supplied from an external AC power source 2. The battery heating unit 802 of the temperature control device 800 heats up the battery 100 by energizing the electric heater 810. The planning unit 320 of the ECU 300 creates a heating plan from the end of external charging to the scheduled start time Dt so that the temperature TB of the battery 100 reaches the target temperature Ttb at the scheduled start time Dt. The power control unit 330 of the ECU 300 controls the power supplied to the electric heater 810 based on the heating plan. The planning unit 320 calculates the charging energy charge unit price Cup, which is the unit price of electricity used for this charging, and creates a heating plan so that the power of the battery 100 is used during the time when the energy charge unit price Eup of the external AC power source 2 is higher than the charging energy charge unit price Cup, and the power of the external AC power source 2 is used during the time when the energy charge unit price Eup is less than or equal to the charging energy charge unit price Cup. Therefore, the temperature of battery 100 at the scheduled start time Dt can be raised to the target temperature Ttb. In addition, during periods when the electricity rate Eup for external AC power supply 2 is higher than the electricity rate Cup for charging, the power from battery 100 is used, thus reducing the electricity cost required for raising the temperature.

[0060] The power control unit 330 supplies power from the external AC power supply 2 to the electric heater 810 when the State of Charge (SOC) of the battery 100 is below a predetermined value A. As a result, the SOC of the battery 100 does not fall below a predetermined value A when the electric vehicle 1 starts running, thus suppressing the electricity costs required for heating while preventing a decrease in the amount of power available for use during operation.

[0061] According to this embodiment, the temperature control method includes obtaining the scheduled start time Dt of the electric vehicle 1 (S13), obtaining the target temperature Ttb of the battery 100 at the scheduled start time Dt (S13), obtaining the charging electricity charge Cc for the amount of charging energy CA from the start to the end of charging of the external AC power supply 2 (S11), obtaining the unit price Eup for the amount of energy charge of the external AC power supply 2 (S12, 13), calculating the unit price Cup for the amount of energy charge of the charging energy based on the charging electricity charge Cc (S12), creating a temperature rise plan from the end of charging of the external AC power supply 2 to the scheduled start time Dt so that the temperature of the battery 100 reaches the target temperature Ttb at the scheduled start time Dt (S14), and controlling the electric heater 810 based on the temperature rise plan (S16 to S21).

[0062] The heating plan is designed so that when the electricity rate Eup of the external AC power supply 2 is higher than the electricity rate Cup, power from battery 100 is supplied to the electric heater 810, and when the electricity rate Eup is lower than or equal to the electricity rate Cup, power from the external AC power supply 2 is supplied to the electric heater 810. Therefore, the temperature of battery 100 at the scheduled start time Dt can be raised to the target temperature Ttb, and the electricity cost required to heat up battery 100 can be reduced.

[0063] In the temperature control method of this embodiment, when controlling power to the electric heater 810 based on the temperature rise plan, if the State of Charge (SOC) of the battery 100 is less than or equal to a predetermined value A, power from the external AC power source 2 is supplied to the electric heater 810 even during the time when power from the battery 100 is supplied to the electric heater 810 (S16 to S21). This suppresses the electricity costs required for temperature rise while suppressing the decrease in the amount of power available when the electric vehicle 1 is running.

[0064] In addition, in S14 of the above embodiment, the ECU 300 may take into account the electricity rate unit price Eup and determine the power supply and power supply time period to reduce electricity costs, and create a temperature rise plan. For example, if the power supply start time falls within a time period with a low electricity rate unit price Eup, and the power supply end time falls within a time period with a high electricity rate unit price Eup, the electricity cost may be lower than raising the temperature of the battery 100 using a uniform power supply by making the power supply in the initial period (low-cost period) of the power supply time period greater than the power supply in the later period (high-cost period) of the power supply time period. Furthermore, if the scheduled start time Dt falls within a period of high electricity rates (Eup), depending on the relationship between the time of transition from a low-rate period to a high-rate period (switching time), the scheduled start time Dt, and the unexpected ambient temperature at the start of operation, it may be possible to raise the temperature TB at the switching time to a temperature higher than the target temperature Ttb by supplying power during the low-rate period, and then stop supplying power, causing the temperature TB to decrease to the target temperature Ttb by heat dissipation at the scheduled start time Dt, while still incurring lower electricity costs than if power were supplied during the high-rate period.

[0065] Thus, the ECU300 may determine the power supply and energizing time to minimize electricity costs based on the current temperature TB, the target temperature Ttb, the change in ambient temperature from the present time to the scheduled start time Dt, and the electricity rate per unit Eup. In this case, the power consumption of the electric pump that circulates the heat transfer medium in the battery heat circuit may also be taken into consideration when calculating the electricity cost during the heating process.

[0066] Furthermore, in the temperature rise plan, the power supply and energizing time may be set so that the temperature TB of the battery 100 after charging is not below the minimum temperature required to prevent freezing.

[0067] In the above embodiment, the electric vehicle 1 is a BEV, but the electric vehicles to which this disclosure can be applied are not limited to BEVs. For example, this disclosure can also be applied to plug-in hybrid electric vehicles (PHEVs) equipped with an engine and a motor generator, and to fuel cell electric vehicles (FCEVs) equipped with an externally rechargeable battery. It can also be applied to industrial vehicles such as forklifts.

[0068] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0069] 1 Electric vehicle, 2 External AC power supply, 3 User terminal, 5 External server, 10 Motor generator (MG), 20 Drive transmission gear, 30 Drive wheel, 40 PCU, 50 SMR, 80 AC inlet, 90 Charging relay, 100 Battery, 200 Monitoring unit, 300 ECU, 320 Planning unit, 321 Charging energy amount calculation unit, 322 Charging electricity amount calculation unit, 323 Charging electricity rate unit calculation unit, 324 Driving start time acquisition unit, 325 Target temperature acquisition unit, 330 Power control unit, 500 EVSE, 520 Connector, 600 HMI device, 800 Temperature control device, 801 Battery cooling unit, 802 Battery heating unit, 810 Electric heater, HP Heating plan.

Claims

1. An electric vehicle equipped with a battery that can be charged by power supplied from an external power source, A heating device that uses electricity to raise the temperature of the storage battery, The system comprises a control device for controlling the heating device, The control device is A planning unit creates a temperature rise plan from the end of charging to the scheduled start time of driving so that the temperature of the storage battery reaches a predetermined temperature at the scheduled start time of driving of the electric vehicle, Includes a power control unit that controls the power supplied to the heating device based on the heating plan, The aforementioned planning department, We will calculate the unit price of the electricity used for this charge, which is the charge rate per unit of electricity. An electric vehicle that creates a temperature rise plan such that it uses the power of the storage battery during times when the electricity rate per unit of the external power source is higher than the electricity rate per unit of the charging power source, and uses the power of the external power source during times when the electricity rate per unit of the charging power source is lower than or equal to the electricity rate per unit of the charging power source.

2. The electric vehicle according to claim 1, wherein the power control unit supplies power from the external power source to the heating device when the state of charge (SOC) of the storage battery is below a predetermined value.

3. The control device is configured to communicate with an external server, The electric vehicle according to claim 1 or 2, wherein the planning unit obtains information regarding the unit price of the electricity charges from the external server.

4. A method for controlling the temperature of a battery mounted in a vehicle, which can be charged from an external power source and whose temperature is raised by a heating device, The heating device uses electricity to raise the temperature of the storage battery, The temperature control method is as follows: To obtain the scheduled start time of the aforementioned electric vehicle, To obtain the target temperature of the battery at the scheduled start time of driving, To obtain the electricity cost for the amount of electricity charged from the start to the end of charging of the aforementioned external power supply, To obtain the unit price of electricity charges for the aforementioned external power source, Based on the aforementioned electricity charges for charging, the unit price for the amount of electricity used for charging will be calculated. To create a temperature rise plan from the end of charging to the scheduled start time of driving so that the temperature of the storage battery reaches the target temperature at the scheduled start time of driving, This includes controlling the heating device based on the aforementioned heating plan, The aforementioned temperature increase plan is: During periods when the electricity rate per unit of the external power supply is higher than the electricity rate per unit of the charging power supply, the power from the storage battery is supplied to the heating device. A battery temperature control method configured to supply power from the external power source to the heating device during the time period when the electricity rate per unit is less than or equal to the charging electricity rate per unit.

5. The aforementioned temperature adjustment method is: This further includes obtaining the State of Control (SOC) of the aforementioned storage battery, The battery temperature control method according to claim 4, wherein when controlling the heating device based on the heating plan, if the SOC is below a predetermined value, power from the external power source is supplied to the heating device even during the time period when power from the battery is supplied to the heating device.

Images