Patent ID: 12246580

DESCRIPTION OF EMBODIMENTS

[Vehicle]

A vehicle V in the present embodiment is, for example, an electric vehicle such as a plug-in hybrid vehicle or an electric automobile, includes a battery BAT capable of storing electric power from an external power supply100provided in a charging station, a home, or the like as shown inFIG.1. The vehicle is capable of traveling on the electric power stored in the battery BAT. The battery BAT is implemented by stacking a plurality of battery cells (not shown), and is, for example, a lithium ion battery or a nickel hydrogen battery. In addition, the battery BAT is provided with a temperature sensor60that detects a temperature of the battery BAT (hereinafter also referred to as a battery temperature). InFIG.1, a thick solid line indicates mechanical connection, and a double line indicates electric wiring. In addition, the configuration shown inFIG.1is an example, and a part of the configuration may be omitted, or another configuration may be added.

The vehicle V is provided with a charge port10and a charger OBC (on-board charger) disposed between the charge port10and the battery BAT. When a charge plug of a charge cable110of the external power supply100is connected (plugged in) to the charge port10, the charger OBC converts a current introduced from the external power supply100via the charge port10, for example, converts an AC during normal charge into a DC, and outputs the converted DC to the battery BAT In this way, the battery BAT stores electric power supplied from the external power supply100. The configuration for charging the battery BAT by the external power supply100is not limited thereto. For example, the battery BAT may be charged by a configuration in which a power receiving coil or the like capable of receiving electric power transmitted from the external power supply100in a non-contact manner is provided in the vehicle V.

The vehicle V includes a drive unit DU a temperature control device20, a control device CTR, and a communication device70.

The drive unit DUT includes a DC-DC converter CONV, an inverter INV, and a motor MOT. The DC-DC converter CONV boosts electric power supplied from the battery BAT and outputs the boosted electric power to the inverter INV. The inverter INV converts a DC supplied from the DC-DC converter CONV into an AC and outputs the AC to the motor MOT. The motor MOT is, for example, a three-phase AC motor, and is driven by electric power supplied from the battery BAT via the DC-DC converter CONV and the inverter INV An output of the motor MOT is transmitted to drive wheels DW of the vehicle V, and thus the vehicle V travels.

The control device CTR controls the charger OBC, the battery BAT, the drive unit DU, the temperature control device20, and the communication device70. In addition, the control device CTR also controls a battery heater ECH1and a heating heater ECH2to be described later. The control device CTR is implemented by an electronic control unit (ECU) including a processor, a memory, an interface, and the like. The control device CTR may be implemented by a plurality of control devices, that is, the control device may be provided for each of the above-described control objects.

The communication device70includes a wireless module for connecting to a cellular network or a Wi-Fi network. The communication device70is a communication interface that communicates, via a network such as the Internet or Ethernet, with a user terminal200(for example, a smartphone or a tablet terminal) operated by a user of the vehicle V.

The communication device70cooperates with schedule information on the vehicle V registered in advance by the user in the user terminal200. The control device CTR acquires the schedule information on the vehicle V via the communication device70. Then, the control device CTR acquires a start time of the vehicle V based on the schedule information. Here, the start time of the vehicle V includes a time when the vehicle V starts and a pre-air-conditioning start time when an operation of an air conditioner is started before the start. When the schedule information on the vehicle V is stored in an external server different from the user terminal200, the communication device70may communicate with the external server via a network, and the control device CTR may acquire the schedule information on the vehicle V via the communication device70and acquire the start time of the vehicle V based on the schedule information.

[Temperature Control Device]

As shown inFIG.2, the temperature control device20includes an air conditioner30that heats or cools a vehicle compartment, a battery temperature control circuit40that warms or cools down the battery BAT, and a first heat exchanger50that performs heat exchange between a heat pump circuit31of the air conditioner30and the battery temperature control circuit40.

[Battery Temperature Control Circuit]

A liquid coolant C1(for example, water) circulates inside the battery temperature control circuit40, and heat exchange is performed between the battery BAT and the charger OBC.

Specifically, in the battery temperature control circuit40, when the battery BAT is charged with the electric power from the external power supply100before the start of the vehicle V, the charger OBC generates heat and has a high temperature. The charger OBC performs heat exchange with the coolant C1flowing through the battery temperature control circuit40, the charger OBC is cooled down, and the coolant C1is warmed. The warmed coolant C1circulates through the battery temperature control circuit40to perform heat exchange with the battery BAT, thereby warming the battery BAT. A black arrow Y1shown inFIG.3indicates transfer of heat from the charger OBC to the battery BAT. In this way, the battery BAT stores heat from the charger OBC via the coolant C1during charging by the external power supply100.

The battery temperature control circuit40is provided with the battery heater ECH1. The battery heater ECH1is, for example, an electric heater (electric coolant heater), and operates by electric power from the external power supply100when the external power supply100is connected, and operates by electric power from the battery BAT when the external power supply100is not connected. Specifically, the coolant C1is warmed by the battery heater ECH1, and the warmed coolant C1performs heat exchange with the battery BAT to warm the battery BAT. A black arrow Y2shown inFIG.3indicates transfer of heat from the battery heater ECH1to the battery BAT. In this way, the battery BAT stores the heat from the battery heater ECH1via the coolant C1.

Further, the battery BAT generates heat by itself when being charged by the external power supply100, and stores the heat generated by itself.

Since the battery BAT has a large thermal capacity and easily stores heat, as described above, the charge plug coupled to the external power supply100is connected to the vehicle V after the use of the vehicle V until the next use of the vehicle V to charge the battery BAT, and thus the heat from the charger OBC, the heat from the batter heater ECH1, and the heat generated by the battery BAT itself are stored in the battery BAT.

[Air Conditioner]

The air conditioner30includes the heat pump circuit31, a temperature increase circuit32, and a second heat exchanger33that performs heat exchange between the heat pump circuit31and the temperature increase circuit32. The heat pump circuit31includes a refrigeration cycle including a compressor, a condenser, an expansion valve, an evaporator, and the like, and a liquid coolant C2(for example, an air-conditioning coolant) flows therein. The condenser (hereinafter, referred to as a third heat exchanger34) of the heat pump circuit31is exposed to outside air, and is capable of absorbing heat (that is, heat-pumping) from the outside air under a low-temperature environment when heating the vehicle compartment. A black arrow Y3shown inFIGS.4and5indicates transfer of heat from the outside air to the third heat exchanger34.

The liquid coolant C1(for example, water) flows inside the temperature increase circuit32. The coolant in the temperature increase circuit32and the coolant in the battery temperature control circuit40are both the coolant C1and are common. The coolant C1in the temperature increase circuit32performs heat exchange with the coolant C2in the heat pump circuit31via the second heat exchanger33, and thus a temperature thereof is increased. A black arrow Y4shown inFIGS.4and5indicates transfer of heat from the third heat exchanger34to the temperature increase circuit32via the second heat exchanger33.

The heating heater ECH2is provided in the temperature increase circuit32, and the temperature of the coolant C1in the temperature increase circuit32is also increased by heat from the heating heater ECH2. The heating heater ECH2is, for example, an electric heater (electric coolant heater). A black arrow Y5shown inFIGS.4and5indicates transfer of heat from the heating heater ECH2to a heater core35.

The temperature of the coolant C1in the temperature increase circuit32is increased by heat transferred from the heat pump circuit31to the temperature increase circuit32via the second heat exchanger33and heat from the heating heater ECH2, and heat exchange is performed with conditioned air in the heater core35to heat the vehicle compartment.

[Heating Mode]

(Battery-Heat Absorption Mode)

As described above, the first heat exchanger50enabling heat exchange between the coolant C1and the coolant C2is provided between the heat pump circuit31and the battery temperature control circuit40. Therefore, heat (arrow Y1inFIG.3) from the charger OBC during charge, heat (arrow Y2inFIG.3) from the battery heater ECH1, and heat (not shown) stored in the battery BAT by self-heat-generation of the battery BAT during charge are transmitted to the heat pump circuit31via the first heat exchanger50. A black arrow Y6shown inFIG.4indicates transfer of heat from the battery temperature control circuit40to the heat pump circuit31. Then, the heat (arrow Y6inFIG.4) from the battery BAT is transmitted to the temperature increase circuit32via the second heat exchanger33together with heat (arrow Y3inFIG.4) from the outside air, and heat (arrow Y5inFIG.4) from the heating heater ECH2is applied to heat the vehicle compartment. That is, in this heating mode, the heat stored in the battery BAT is absorbed and used to heat the vehicle compartment in addition to outside-air-heat absorption. Hereinafter, heat absorption from the battery BAT is also referred to as battery-heat absorption, and an operation mode in which heating of the vehicle compartment is performed by battery-heat absorption is also referred to as a battery-heat absorption mode.FIG.4shows a flow of heat in the battery-heat absorption mode.

(Outside-Air-Heat Absorption Mode)

On the other hand, an operation mode in which the vehicle compartment is heated by absorbing heat from the outside air without using the heat stored in the battery BAT is also referred to as an outside-air-heat absorption mode.FIG.5shows a flow of heat in the outside-air-heat absorption mode.

Here,FIG.6Ais a graph in which a vertical axis represents an effective capacity of the battery BAT and a horizontal axis represents the battery temperature. The effective capacity of the battery BAT refers to a capacity that can be used for operating the vehicle V in a charge capacity. As shown inFIG.6A, when the battery temperature decreases, the effective capacity of the battery BAT decreases. In the present embodiment, by warming the battery BAT before the start of the vehicle V, the heat stored in the battery BAT can be used to heat the vehicle compartment as described above, and, in addition, the effective capacity of the battery BAT can be increased.

FIG.6Bis a graph in which a vertical axis represents a ratio (expressed by a percentage) of an electric power amount P1in the battery-heat absorption mode to an electric power amount P2in the outside-air-heat absorption mode, and a horizontal axis represents the battery temperature at the start of the vehicle V The electric power amounts P1and P2are electric power amounts (that is, electricity costs) of the battery BAT consumed when the air conditioner30performs heating for a predetermined time (for example, 30 minutes). When the vertical axis is 100%, it means that the electric power amount P1is equal to the electric power amount P2. When a value of the vertical axis is smaller than 100%, the electric power amount P1is smaller than the electric power amount P2, that is, the battery-heat absorption mode is more efficient than the outside-air-heat absorption mode.

As shown inFIG.6B, when the battery temperature at the start of the vehicle V is −10° C. to 15° C., the electric power amount P1in the battery-heat absorption mode is about 80% to 95% of the electric power amount P2in the outside-air-heat absorption mode, and, when the battery temperature is 15° C. or higher, the electric power amount P1in the battery-heat absorption mode converges to about 80% of the electric power amount P2in the outside-air-heat absorption mode. In this way, in the battery-heat absorption mode, the electric power consumption amount of the battery BAT used for heating the vehicle compartment is smaller than that in the outside-air-heat absorption mode. Accordingly, in the battery-heat absorption mode, it is possible to reduce a decrease in a charge amount (also referred to as a state of charge (SOC)) of the battery BAT due to heating, and to improve a cruising distance of the vehicle V.

[Heating Control Method]

Next, a heating control method according to the present embodiment will be described.

FIG.7is a graph showing changes over time in the battery temperature, the temperature of the coolant C2in the heat pump circuit31, the temperature of the coolant C1in the battery temperature control circuit40, and the outside air temperature. In addition,FIG.7shows a graph representing a change over time in an amount of heat absorbed by the coolant C2in the heat pump circuit31from the coolant C1in the battery temperature control circuit40in the first heat exchanger50.FIG.7shows a case where heating is continued in the battery-heat absorption mode from a time t0when the air conditioner30starts an operation to a time t2when the operation is completed. InFIG.7, the outside air temperature is a constant value, that is, −10° C. from the time t0to the time t2. In addition, the temperature of the coolant C2is a temperature immediately before receiving the heat from the battery BAT in the first heat exchanger50, and is lower than the battery temperature. InFIG.7, the temperature of the coolant C2has a constant value, that is, −20° C. from the time t0to the time t2.

When heating is performed in the battery-heat absorption mode from the time t0, the heat stored in the battery BAT is transferred to the heat pump circuit31via the first heat exchanger50(arrow Y6inFIG.4). Accordingly, the battery temperature and the temperature of the coolant C1in the battery temperature control circuit40gradually decrease from 20° C. at the time t0. As the temperature of the coolant C1decreases, a temperature difference with the temperature of the coolant C2in the heat pump circuit31decreases, and an amount of heat absorbed in the first heat exchanger50gradually decreases.

As shown inFIGS.6A and6B, when the battery temperature is high, the effective capacity of the battery BAT is high, and heating efficiency by battery-heat absorption is favorable. However, when the battery temperature decreases as the heating is continued in the battery-heat absorption mode, the heating efficiency by the battery-heat absorption deteriorates, and the cruising distance of the vehicle V decreases as the effective capacity of the battery BAT decreases, Thus, heating in the battery-heat absorption mode has favorable heating efficiency over a short time, the heating efficiency gradually deteriorates over a long time and, further, the cruising distance may decrease. Therefore, it may not be preferable to continue the heating of the vehicle V in the battery-heat absorption mode from the time t0to the time t2.

Therefore, after the operation of the air conditioner30is started in a state where the battery-heat absorption mode is selected, the control device CTR switches the mode from the battery-heat absorption mode to the outside-air-heat absorption mode or reduces the amount of heat absorbed from the battery BAT in the battery-heat absorption mode, based on a predetermined condition.

Specifically, as shown inFIG.7, the control device CTR selects the battery-heat absorption mode at the time t0and then starts the operation of the air conditioner30. Then, at a time t1, the control device CTR switches the mode from the battery-heat absorption mode to the outside-air-heat absorption mode, or reduces the amount of heat absorbed from the battery BAT in the battery-heat absorption mode. Here, the time t1is a time when an amount of decrease in the battery temperature since the start of the operation of the air conditioner is equal to or larger than a predetermined temperature decrease amount (for example, when the battery temperature decreases by 10° C. or more).

More specifically, before the time t1, the air conditioner30heats the vehicle compartment by using at least heat absorbed from the battery BAT. Accordingly, since it is possible to perform heating by efficient battery-heat absorption in the state where the battery temperature is relatively high, the electricity cost of the vehicle V is improved. Before the time t1, only the battery-heat absorption may be performed, or the battery-heat absorption may be performed together with outside-air-heat absorption.

After the time11, the air conditioner30switches the mode to the outside-air-heat absorption mode to perform heating by absorbing heat from the outside air without absorbing heat from the battery BAT or maintains the battery-heat absorption mode while reducing the amount of heat absorbed from the battery BAT to less than that before the time t1and increasing an amount of heat absorbed from the outside air instead to perform heating. Accordingly, it is possible to prevent the heating in the battery-heat absorption mode from continuing in a state where the heating efficiency by the battery-heat absorption deteriorates when the battery temperature decreases to a certain extent. Thus, a further decrease in the battery temperature is prevented, so it is possible to prevent a decrease in the effective capacity of the battery BAT, that is, it is possible to prevent a decrease in the cruising distance.

By appropriately controlling the heat absorption from the battery BAT as described above, it is possible to achieve a balance between the electricity cost and the cruising distance of the vehicle V.

Here, the predetermined temperature decrease amount is preferably determined based on a decrease amount of the effective capacity of the battery BAT due to the decrease in the battery temperature. For example, the predetermined temperature decrease amount is determined such that a decrease in the effective capacity from the time t0is 10% Accordingly, it is possible to prevent an excessive decrease in the cruising distance of the vehicle V caused by the decrease in the effective capacity of the battery BAT due to the decrease in the battery temperature.

The control device CTR may switch the mode from the battery-heat absorption mode to the outside-air-heat absorption mode or may reduce the amount of heat absorbed from the battery BAT in the battery-heat absorption mode when a predetermined time elapses since the start of the operation of the air conditioner30. Specifically, the mode may be switched from the battery-heat absorption mode to the outside-air-heat absorption mode or the amount of heat absorbed from the battery BAT in the battery-heat absorption mode may be reduced at a time when a predetermined time (for example, 30 minutes) elapses from the time t0when the operation of the air conditioner30is started. With such a configuration, it is possible to perform efficient heating by battery-heat absorption in an initial stage when the battery temperature is relatively high, and to prevent the heating in the battery-heat absorption mode from continuing in a state where the heating efficiency by battery-heat absorption deteriorates when the battery temperature is low after the initial stage.

The above-described control of battery-heat absorption can achieve a balance between the electricity cost and the cruising distance of the vehicle V However, for example, when the vehicle V is to travel for a long time, priority may be given to the cruising distance. In such a case, it may be favorable to perform heating by the outside-air-heat absorption mode instead of the battery-heat absorption mode since the start of the operation of the air conditioner30. Thus, it is preferable that the control device CTR determines in which mode the air conditioner30is to be operated before the vehicle V starts traveling. In the following description, control under which the heating in the battery-heat absorption mode is performed during travel of the vehicle V is referred to as “battery-heat absorption priority control”. In other words, the battery-heat absorption priority control includes control under which the vehicle compartment is heated in the battery-heat absorption mode at the start of the operation of the air conditioner30and then the mode is switched to the outside-air-heat absorption mode, and control under which the amount of heat absorbed from the battery BAT is reduced in the middle of heating the vehicle compartment in the battery-heat absorption mode. In addition, the control under which the heating in the outside-air-heat absorption mode is performed without in the battery-heat absorption mode during travel of the vehicle V is referred to as the “outside-air-heat absorption priority control”.

FIG.8is a graph showing a change over time in energy required for travel of the vehicle V (hereinafter, also referred to as travel-required energy) when the battery-heat absorption priority control is performed (thin solid line) and a change over time in the travel-required energy of the vehicle V when the outside-air-heat absorption priority control is performed (thin broken line). A time t0′ is a time when the vehicle V is predicted to start traveling. A time t1′ is a time when switching from the battery-heat absorption mode to the outside-air-heat absorption mode is predicted in consideration of the heating efficiency when the battery-heat absorption priority control is performed, and corresponds to the time t1inFIG.7. A time t2′ is a time when completion of travel of the vehicle V is predicted.

FIG.8also shows a graph showing a change over time in the effective capacity of the battery BAT when the battery-heat absorption priority control is performed (thick solid line) and a change over time in the effective capacity of the battery BAT when the outside-air-heat absorption priority control is performed (thick broken line). To specifically describe the graph on the effective capacity, when the battery-heat absorption priority control is performed (thick solid line), the battery temperature decreases from the time t0′ to the time t1′ due to battery-heat absorption, and the effective capacity of the battery BAT decreases from the time t0′ to the time t1′. The battery temperature is maintained without performing battery-heat absorption from the time t1′ to the time t2′, and the effective capacity of the battery BAT is maintained from the time t1′ to the time t2′. When the battery-heat absorption priority control is performed, a difference E1between the effective capacity of the battery BAT at the time t2′ and the travel-required energy is energy (residual capacity) remaining in the battery BAT after the travel is completed. On the other hand, when the outside-air-heat absorption priority control is performed (thick broken line), the battery temperature is maintained from the time t0′ to the time t2′ since no battery-heat absorption is performed. Thus, the effective capacity of the battery BAT is maintained from the time t0′ to the time t2′. When the outside-air-heat absorption priority control is performed, a difference E2between the effective capacity of the battery BAT at the time t2′ and the travel-required energy is the residual capacity of the battery BAT after the travel is completed.

As shown inFIG.8, when the battery-heat absorption priority control is performed, the heating efficiency is favorable and the travel-required energy is small, whereas the effective capacity of the battery BAT is reduced, as compared to the case where the outside-air-heat absorption priority control is performed. Thus, the residual capacity E1of the battery BAT when the battery-heat absorption priority control is performed may be smaller than the residual capacity E2of the battery BAT when the outside-air-heat absorption priority control is performed (that is, E1<E2).

When it is predicted that the travel is of a relatively short time such that the travel of the vehicle V is completed before the time t1′, the residual capacity of the battery BF at the time of completion of the travel is sufficiently large and the battery BAT does not run out of charge. Therefore, it is preferable that the control device CTR performs the battery-heat absorption priority control to travel in a manner that reduces the travel-required energy and improves the electricity cost. On the other hand, when it is predicted that the travel is of a relatively long time such that the travel of the vehicle V is completed at the time t2′, it is preferable to prioritize the residual capacity of the battery BAT at the time of completion of the travel over traveling with a good electricity cost in order to avoid running out of charge. Thus, when travel for a relatively long time is predicted, as shown in the example inFIG.8, in a case where the residual capacity E2when performing the outside-air-heat absorption priority control is larger than the residual capacity E1when performing the battery-heat absorption priority control, the control device CTR preferably performs the outside-air-heat absorption priority control without performing the battery-heat absorption priority control of the vehicle V from the time t0′.

Next, a control flow through which the control device CTR determines whether to perform the battery-heat absorption priority control or the outside-air-heat absorption priority control before the vehicle V starts traveling will be described with reference toFIG.9.

First, the control device CTR determines whether a travel time of the vehicle V is predictable before the vehicle V starts traveling (step S11). Specifically, when the schedule information on the vehicle V is set by the user or a destination or a travel route of the vehicle V is set in a navigation device (not shown), the control device CTR determines that the travel time of the vehicle V is predictable.

When the travel time of the vehicle V is not predictable (step S11: NO), the control device CTR executes the battery-heat absorption priority control since the start of the operation of the air conditioner30(step S23).

On the other hand, when the travel time of the vehicle V is predictable (step S11: YES), the control device CTR acquires a predicted travel time based on the above-described schedule information or the like (step S13). Then, the control device CTR calculates a battery-heat absorption expectation time (step S15). Here, the battery-heat absorption expectation time is a time in which the heating efficiency by battery-heat absorption is high, and is a time from the time t0to the time t1inFIG.7or a time from the time t0′ to the time t1′ inFIG.8. The control device CTR predicts a temperature change of the battery BAT based on a predetermined thermal model (a predetermined temperature map, a temperature calculation formula, or the like), and calculates the battery-heat absorption expectation time based on the prediction result.

Next, the control device CTR compares the predicted travel time with the battery-heat absorption expectation time (step S17). When the predicted travel time is less than the battery-heat absorption expectation time (step S17: YES), travel of a relatively short time is predicted. Since the heating efficiency by the battery-heat absorption is high in the travel of a relatively short time, the control device CTR executes the battery-heat absorption priority control since the start of the operation of the air conditioner30as described above (step S23).

When the predicted travel time is equal to or longer than the battery-heat absorption expectation time (step S17: NO), travel of a relatively long time is predicted. Then, the control device CTR calculates the travel-required energy in the case of performing the battery-heat absorption priority control and the travel-required energy in the case of performing the outside-air-heat absorption priority control as predicted travel-required energy from when the travel starts to when the travel completes (step S19).

Next, the control device CTR compares the residual capacity E1of the battery BAT when the battery-heat absorption priority control is performed and the residual capacity E2of the battery BAT when the outside-air-heat absorption priority control is performed based on the travel-required energy calculated in step S19and the effective capacity of the battery BAT when the travel completes (step S21).

When the residual capacity E1is larger than the residual capacity E2(step S21: YES), the control device CTR executes the battery-heat absorption priority control since the start of the operation of the air conditioner (step S23).

On the other hand, when the residual capacity E2is equal to or larger than the residual capacity E1(step S21: NO), the control device CTR executes the outside-air-heat absorption priority control since the start of the operation of the air conditioner30(step S25). Accordingly, when travel of a relatively long time is predicted, it is possible to prioritize the residual capacity of the battery BAT at the time of the completion of travel, and it is possible to avoid running out of charge.

Although various embodiments have been described above with reference to the drawings, it is needless to say that the present invention is not limited to these examples. It is apparent that those skilled in the art can conceive of various modifications and changes within the scope described in the claims, and it is understood that such modifications and changes naturally fall within the technical scope of the present invention. In addition, respective constituent elements in the above embodiment may be freely combined without departing from the gist of the invention.

The battery temperature control circuit40may allow the coolant C1to perform heat exchange with the drive unit DU. During driving of the drive unit DU (for example, when the vehicle V travels), the drive unit DU has a high temperature. With such a configuration, the drive unit DU is cooled down by the coolant C1, and the coolant C1that receives heat from the drive unit DU is warmed. The coolant C1that receives the heat from the drive unit DU can supply the heat to the heat pump circuit31via the first heat exchanger50. That is, during heating of the vehicle compartment, the air conditioner30can also use the heat from the drive unit DU.

The battery temperature control circuit40may be connected to the temperature increase circuit32via an on-off valve. In this case, the vehicle compartment can be heated by the coolant C1flowing through the battery temperature control circuit40and the temperature increase circuit32through the on-off valve without passing through the first heat exchanger50.

The coolant in the battery temperature control circuit40may be different from the coolant in the temperature increase circuit32.

The time t1inFIG.7may be a time when the battery temperature is equal to or lower than a predetermined temperature (for example, the battery temperature is equal to or lower than 10° C.). The predetermined temperature at this time may be determined based on the effective capacity of the battery BAT.

In step S17inFIG.9, the control device CTR compares the predicted travel time with the battery-heat absorption expectation time, but the invention is not limited thereto, and comparison may be performed between a predicted heating time and the battery-heat absorption expectation time. At this time, in step S11, the control device CTR determines whether the predicted heating time is predictable, and in step S13, the control device CTR acquires the predicted heating time. For example, when pre-air conditioning is started before the vehicle V starts traveling, the predicted heating time and the battery-heat absorption expectation time are compared in step S17.

In the present description, at least the following matters are described. Although corresponding constituent elements or the like in the above-described embodiment are shown in parentheses, the present invention is not limited thereto.

(1) A heating control method for a vehicle (vehicle V) including a battery (battery BAT) and an air conditioner (air conditioner30) that enables to heat a vehicle compartment, the vehicle being capable of traveling by electric power of the battery,in which an operation mode in which heating of the vehicle compartment is performed includes:an outside-air-heat absorption mode in which the vehicle compartment is heated by absorbing heat from outside air without absorbing heat from the battery; anda battery-heat absorption mode in which the vehicle compartment is heated by absorbing heat from at least the battery,the heating control method includes:after an operation of the air conditioner is started in a state where the battery-heat absorption mode is selected, switching from the battery-heat absorption mode to the outside-air-heat absorption mode, or reducing an amount of heat absorbed from the battery in the battery-heat absorption mode, based on a predetermined condition.

According to (1), since the operation of the air conditioner is started in the state where the battery-heat absorption mode is selected, it is possible to perform heating by battery-heat absorption with high efficiency in a state where a battery temperature is relatively high, and an electricity cost of the vehicle is improved. On the other hand, by switching from the battery-heat absorption mode to the outside-air-heat absorption mode or reducing the amount of heat absorbed from the battery in the battery-heat absorption mode based on the predetermined condition, it is possible to prevent the heating in the battery-heat absorption mode from continuing when the battery temperature decreases to a certain extent. Thus, since a further decrease in the battery temperature is prevented, it is possible to prevent a decrease in an effective capacity of the battery, that is, it is possible to prevent a decrease in a cruising distance. Therefore, it is possible to achieve a balance between the electricity cost and the cruising distance of the vehicle.

(2) The heating control method for the vehicle according to (1),in which when the operation of the air conditioner is started, the vehicle compartment is heated in the battery-heat absorption mode, andthe heating control method includes:switching from the battery-heat absorption mode to the outside-air-heat absorption mode, or reducing the amount of heat absorbed from the battery in the battery-heat absorption mode, at a time (time t1, time t1′) when a temperature decrease amount of the battery since the start of the operation of the air conditioner is equal to or larger than a predetermined temperature decrease amount.

According to (2), it is possible to appropriately control heat absorption from the battery based on the temperature decrease amount of the battery.

(3) The heating control method for the vehicle according to (2), in whichthe predetermined temperature decrease amount is determined based on a decrease amount of an effective capacity of the battery due to a temperature decrease of the battery.

According to (3), it is possible to prevent an excessive decrease in the cruising distance of the vehicle caused by the decrease in the effective capacity of the battery due to the decrease in the battery temperature.

(4) The heating control method for the vehicle according to (1), including:switching from the battery-heat absorption mode to the outside-air-heat absorption mode, or reducing the amount of heat absorbed from the battery in the battery-heat absorption mode, when a predetermined time elapses since the start of the operation of the air conditioner.

According to (4), it is possible to perform efficient heating by battery-heat absorption in an initial stage when the battery temperature is relatively high, and to prevent the heating in the battery-heat absorption mode from continuing in a state where the heating efficiency by battery-heat absorption deteriorates when the battery temperature is low after the initial stage.

(5) The heating control method for the vehicle according to any one of (1) to (4), further including:acquiring a predicted travel time of the vehicle or a predicted heating time of the air conditioner;predicting a first residual capacity (residual capacity E1) of the battery after a lapse of the predicted travel time or the predicted heating time in a case where the heating at least in the battery-heat absorption mode is performed during the predicted travel time or the predicted heating time;predicting a second residual capacity (residual capacity E2) of the battery after a lapse of the predicted travel time or the predicted heating time in a case where the heating in only the outside-air-heat absorption mode is performed during the predicted travel time or the predicted heating time; andheating the vehicle compartment in the outside-air-heat absorption mode since the start of the operation of the air conditioner, in a case where the second residual capacity is equal to or larger than the first residual capacity.

According to (5), it is possible to prioritize the residual capacity of the battery at the time of completion of travel or at the time of completion of heating.