Battery temperature control system for vehicle

Abstract

[Problem] To suppress energy consumption. [Solution] A control unit 11 executes battery temperature control such that temperature of a battery falls within an optimum range, which is set as a first temperature range, in a first time period after a vehicle starts traveling, and the temperature of the battery falls within an allowable range which is a second temperature range broader than the first temperature range in a second time period after the first time period until the vehicle arrives at a destination. Thus, by managing the temperature of the battery 12 so as to be within the allowable range when the vehicle arrives at the destination, unnecessary temperature control of the battery 12 in a range not affecting deterioration and performance of the temperature-controlled battery 12 is not performed, and accordingly energy consumption can be suppressed.

Description

Vehicle battery temperature control system

[0001] The present invention relates to a vehicle battery temperature control system.

[0002] A vehicle battery temperature control system that controls the temperature of a battery mounted on a vehicle is known. For example, Patent Document 1 discloses a technology that stops the temperature control of the battery if it is determined that the battery temperature will not exceed a predetermined temperature when the remaining driving distance or remaining driving time is less than a threshold value.

[0003] Chinese Patent Application Publication No. 116788113

[0004] An object of the present invention is to provide a vehicle battery temperature regulation system that can reduce energy consumption.

[0005] According to one aspect of the present invention, a vehicle battery temperature control system includes a battery mounted on a vehicle, a battery temperature control unit that controls the temperature of the battery, and a control unit capable of executing battery temperature control that controls the temperature of the battery, wherein the control unit executes battery temperature control so that the battery temperature falls within a first temperature range during a first time period after the vehicle starts to travel, and so that the battery temperature falls within a second temperature range that is wider than the first temperature range during a second time period after the first time period until the vehicle arrives at its destination.

[0006] According to the present invention, it is possible to provide a vehicle battery temperature regulation system that can reduce energy consumption.

[0007] Fig. 1 is a functional block diagram showing the overall configuration of a vehicle battery temperature regulation system. Fig. 2 is a diagram showing an example of a flowchart showing the processing procedure in the battery temperature regulation control of the first embodiment. Fig. 3 is a diagram showing a specific example of a change in battery temperature when the battery temperature regulation control of the first embodiment is executed. Fig. 4 is a diagram showing an example of a flowchart showing the processing procedure in the battery temperature regulation control of the second embodiment. Fig. 5 is a diagram showing a specific example of a change in battery temperature when the battery temperature regulation control of the second embodiment is executed.

[0008] [Configuration of Vehicle Battery Temperature Control System] The vehicle battery temperature control system of this embodiment is configured to be able to control the temperature of the battery while taking into account battery degradation, while suppressing an increase in power consumption. The vehicle battery temperature control system of this embodiment is also configured to be able to suppress energy consumption.

[0009] FIG. 1 is an explanatory diagram showing an outline of a configuration example of a vehicle battery temperature regulation system 1 according to this embodiment.

[0010] The vehicle battery temperature control system 1 controls the temperature of a battery mounted in an electric vehicle (EV) such as an electric vehicle or a hybrid vehicle. The vehicle battery temperature control system 1 is incorporated into a vehicle air conditioning device for conditioning the interior of the vehicle.

[0011] The vehicle battery temperature regulation system 1 includes a battery temperature regulation circuit 10 and a control unit 11 .

[0012] The battery temperature control circuit 10 is part of a heat medium circuit used for air conditioning the vehicle interior. The battery temperature control circuit 10 includes a battery 12, a battery temperature control unit 13 that controls the temperature of the battery 12, a circulation pump 14 that pushes out the heat medium, and a heat medium heater 15 that heats the heat medium.

[0013] When the battery 12 is charged or discharged, the battery temperature rises due to self-heating of the battery 12. Therefore, the battery temperature regulation circuit 10 regulates the temperature of the battery 12 to prevent deterioration and performance degradation of the battery 12. In this embodiment, a lithium-ion battery is used as the battery 12. However, a battery other than a lithium-ion battery may also be used as the battery 12.

[0014] The heat medium in the battery temperature control circuit 10 is circulated by the operation of a circulation pump 14. In the battery temperature control circuit 10, the temperature of the battery 12 is adjusted by the heat medium circulating through the battery temperature control circuit 10. The heat medium flowing through the battery temperature control circuit 10 can exchange heat with the refrigerant flowing through a refrigerant circuit 16. The refrigerant circuit 16 includes a compressor, a high-temperature side heat exchanger, a pressure reducing device, and a low-temperature side heat exchanger. The refrigerant circuit 16 is configured to function as a heat pump that circulates the refrigerant and repeatedly compresses, condenses, expands, and evaporates the refrigerant. The heat medium that exchanges heat with the refrigerant in the refrigerant circuit 16 is used for air conditioning in the vehicle cabin and for temperature control of the battery 12 and the motor.

[0015] The control unit 11 is a microcomputer equipped with a processor, a memory, and an input / output interface. The control unit 11 is capable of executing battery temperature control, which controls the temperature of the battery 12. The control unit 11 is capable of controlling the operation of the heat medium circuit, including the battery temperature control circuit 10, and the refrigerant circuit 16. When executing battery temperature control, the control unit 11 can, for example, switch the heat medium circuit so that heat exchange is possible between the heat medium in the battery temperature control circuit 10 and the refrigerant in the refrigerant circuit 16, switch the heat medium circuit so that the heat medium circulates between the battery temperature control circuit 10 and the radiator circuit, or switch the heat medium circuit so that the heat medium circulates through the battery temperature control circuit 10, which is isolated from the other circuits.

[0016] The control unit 11 receives detection signals from various sensors 17. The sensors 17 include an inside air temperature sensor that measures the temperature of the air inside the vehicle cabin, an outside air temperature sensor that detects the outside air temperature, and the like.

[0017] The control unit 11 can transmit and receive data (such as estimated arrival time data, driving route data, and weather information data) to and from the ECU of a navigation device 19 installed in the vehicle via the communication bus 18. The control unit 11 can also obtain necessary data (such as vehicle speed) from other ECUs (not shown) of the vehicle via the communication bus 18. In addition to the information obtained from the vehicle's ECU, the control unit 11 can also obtain detailed route information such as elevation changes and traffic congestion information from the cloud, other vehicles, infrastructure facilities, etc. via V2X communication.

[0018] [Battery Temperature Control] In this embodiment, a lithium-ion battery is used as the battery 12. The optimal temperature for a lithium-ion battery is approximately 25°C ± 5°C (i.e., in the range of 20°C to 30°C). Therefore, when using a lithium-ion battery, it is preferable to manage the temperature at approximately 25°C ± 5°C. However, it is generally believed that managing the temperature of a lithium-ion battery within the allowable temperature range of 0°C to 40°C has little effect on battery performance or lifespan. Therefore, this embodiment takes advantage of this characteristic and performs battery temperature control on the battery 12 according to the vehicle's running time. This reduces power consumption associated with temperature control of the battery 12, or suppresses energy consumption associated with temperature control of the battery 12.

[0019] The vehicle battery temperature control system 1 of this embodiment is equipped with a protection function for the battery 12. Specifically, it is expected that the battery temperature will be equal to the ambient temperature if a long time has passed since the user stopped driving. If the temperature of the battery 12 exceeds the upper limit of the allowable range of 40°C, this may cause thermal runaway or deterioration. Furthermore, if the temperature of the battery 12 exceeds the lower limit of the allowable range, this may cause a decrease in the performance of the battery 12. Therefore, if the battery temperature is less than 0°C or less than 40°C, a vehicle-side battery protection function is activated to ensure that 0°C≦battery temperature≦40°C. Specifically, the control unit 11 forcibly heats the battery 12 when the battery temperature is less than 0°C, and forcibly cools the battery 12 when the battery temperature is less than 40°C. Therefore, the battery temperature control described below is performed assuming that the battery temperature is between 0°C and 40°C.

[0020] Below, we will explain the battery temperature control of the first embodiment and the battery temperature control of the second embodiment that can be executed by the control unit 11, but it is possible to execute only one of the controls, or to execute both controls.

[0021] In this embodiment, the optimum temperature range of the battery 12 will be described as a range that has less effect on deterioration and performance of the battery 12 than the allowable range. In this embodiment, the optimum range is 20°C to 30°C, and the allowable range is 0°C to 40°C. The optimum range and the allowable range are not limited to this embodiment and can be set as appropriate.

[0022] <Battery Temperature Control of First Embodiment> When the vehicle is traveling for a short period of time, it is expected that the effect of suppressing deterioration of the battery 12 is small compared to the power consumption required to maintain the temperature of the battery 12 within the optimal temperature range. That is, when maintaining the temperature of the battery 12 within the optimal temperature range, power consumption increases due to factors such as the need to increase the compressor rotation speed to enhance the heat absorption effect of the refrigerant. On the other hand, since the battery 12 is used for a short period of time during short traveling, it is expected that even if the temperature of the battery 12 does not fall within the optimal temperature range, the impact on deterioration of the battery 12 is small or almost negligible. Therefore, it is preferable to perform battery temperature control that takes into account the cost-effectiveness of the power consumed when performing battery temperature control to suppress deterioration of the battery 12. Therefore, the control unit 11 can perform the battery temperature control shown in FIG. 2.

[0023] FIG. 2 is a flowchart showing an example of the battery temperature regulation control by the control unit 11.

[0024] 2, the control unit 11 acquires vehicle driving information (S1). The driving information includes, for example, remaining battery charge, battery temperature, outside air temperature, driving distance, and driving time. This information can be acquired based on departure point information, destination information, and route information obtained from learning data, settings for the navigation device 19, data acquired from the cloud, data obtained through communications with other vehicles, data acquired from infrastructure facilities, etc.

[0025] Next, the control unit 11 predicts the temperature rise of the battery based on the driving information, and predicts the temperature of the battery 12 when the vehicle arrives at the destination based on the predicted temperature rise of the battery (S2). Specifically, the control unit 11 predicts the timing of battery charge / discharge requests until the vehicle arrives at the destination. Then, based on the battery temperature and the amount of heat generated by the battery 12 during driving due to charging and discharging, the control unit 11 predicts the temperature rise of the battery if temperature control is not performed from the time the vehicle starts driving until it arrives at the destination, and predicts the temperature of the battery 12 when the vehicle arrives at the destination based on the prediction result.

[0026] Next, the control unit 11 determines whether the vehicle's travel time exceeds a threshold value (S3). Whether the vehicle's travel time exceeds a threshold value may be determined based on a travel time predicted from the travel route, or based on a travel distance predicted from the travel route.

[0027] Next, when the control unit 11 determines that the vehicle running time exceeds the threshold value (S3: YES), in other words, when it determines that the vehicle running time is a long time, it performs first battery temperature control to adjust the temperature of the battery 12 so that the temperature of the battery 12 falls within an optimum range (S4). That is, in step S4, it executes battery temperature management control to manage the temperature of the battery 12 within the optimum range.

[0028] Furthermore, if the control unit 11 determines that the vehicle's driving time does not exceed the threshold value (S3: NO), in other words, if it determines that the vehicle's driving time is a short driving time, it determines, based on the prediction result of step S2, whether the temperature of the battery 12 will exceed the upper limit of the allowable range of 40°C when the vehicle arrives at the destination (S5).

[0029] If the control unit 11 determines that the temperature of the battery 12 will exceed the upper limit of 40°C of the allowable range when the vehicle arrives at the destination (S5: YES), the control unit 11 performs second battery temperature control to adjust the temperature of the battery 12 so that the temperature of the battery 12 falls within the allowable range (S6). That is, in step S6, battery temperature management control is executed to manage the temperature of the battery 12 within the allowable range.

[0030] If the control unit 11 determines that the temperature of the battery 12 will not exceed the upper limit of 40°C of the allowable range when the vehicle arrives at the destination (S5: NO), it halts the execution of battery temperature management control based on the target temperature and temperature management range (S7). At this time, the control unit 11 may stop the operation of the circulation pump 14 to stop the circulation of the heat medium in the battery temperature control circuit 10. Alternatively, the control unit 11 may simply circulate the heat medium in the battery temperature control circuit 10 without managing the battery temperature based on the target temperature and temperature management range. For example, the control unit 11 may circulate the heat medium in the battery temperature control circuit 10 without cooling the radiator or exchanging heat with the refrigerant. This eliminates temperature variations between the battery cells of the battery 12 and prevents deterioration of the battery 12.

[0031] When the travel time of the vehicle is equal to the threshold value, it may be determined that the vehicle has traveled for a long time or for a short time.

[0032] As described above, by changing the battery temperature control when the battery 12 is used for a long time and when it is used for a short time, it is possible to control the temperature of the battery 12 within an optimal range that takes into account the deterioration of the battery 12 when the battery 12 is used for a long time, while suppressing an increase in power consumption that would otherwise be caused by unnecessarily controlling the temperature within the optimal range when the battery 12 is used for a short time.

[0033] In other words, by controlling the temperature of battery 12 within the optimal range during long-term driving, the life of battery 12 can be extended, and by controlling the temperature of battery 12 within the acceptable range during short-term driving, it is possible to suppress an increase in power consumption while suppressing a decrease in performance of battery 12.

[0034] The temperature of the battery 12 may be adjusted in real time by monitoring the battery temperature while the vehicle is running, or may be adjusted as a pre-temperature adjustment before passengers get in the vehicle.

[0035] For example, the control unit 11 determines whether to perform pre-temperature control by determining whether an occupant is scheduled to board the vehicle. Whether an occupant is scheduled to board the vehicle can be determined, for example, from activation of the vehicle system before the occupant boards the vehicle via a remote control operation from outside the vehicle, activation of the vehicle system before the occupant boards the vehicle via a timer, or learning data based on the behavioral patterns of the vehicle owner.

[0036] The control unit 11 then performs pre-temperature control when an occupant is scheduled to board the vehicle and the battery 12 is being externally charged. The pre-temperature control can be performed together with pre-air conditioning, which pre-conditions the interior of the vehicle.

[0037] In this case, pre-temperature control alone is not enough to keep the temperature of the battery 12 within the optimal range during long-term driving. Therefore, in the battery temperature control in step S4 of FIG. 2 , pre-temperature control is performed to keep the temperature of the battery 12 within the optimal range before the vehicle starts running. Alternatively, pre-temperature control is performed to bring the temperature of the battery 12 close to the optimal range before the vehicle starts running, and then, when the temperature of the battery 12 exceeds the upper limit of the optimal range (30°C) while the vehicle is running, the battery 12 is cooled to control the temperature. For example, in pre-temperature control, the temperature of the battery 12 is controlled by cooling or heating the heat medium through heat exchange in the refrigerant circuit 16, and while the vehicle is running, the battery 12 is cooled by cooling the heat medium through the radiator. At this time, the battery 12 is cooled so that the temperature of the battery 12 does not drop below the lower limit of the optimal range. As a result, the temperature of the battery 12 is kept within the optimal range.

[0038] On the other hand, during short-term driving, the temperature of the battery 12 can be kept within the allowable range with only pre-temperature control. Therefore, in the battery temperature control in step S6 of FIG. 2, if pre-temperature control is performed so that the temperature of the battery 12 falls within the allowable range when the vehicle arrives at the destination without performing temperature control while the vehicle is driving, the pre-temperature control cools the battery 12 so that the temperature of the battery 12 reaches the upper limit of the allowable range, 40°C, when the vehicle arrives at the destination. For example, pre-temperature control cools the heat medium through heat exchange in the refrigerant circuit 16. As a result, the temperature of the battery 12 falls within the allowable range. In this case, temperature control is not required while the vehicle is driving, thereby reducing power consumption during driving.

[0039] On the other hand, in the battery temperature control in step S6 of FIG. 2 , if the temperature of the battery 12 exceeds the upper limit of 40°C of the allowable range when the vehicle arrives at the destination even after performing pre-temperature control, the battery 12 is cooled as much as possible so as not to fall below the lower limit of the allowable range. Then, when it is determined that the temperature of the battery 12 will exceed the upper limit of 40°C of the allowable range while the vehicle is running, the temperature of the battery 12 is controlled by cooling the battery 12. For example, in the pre-temperature control, the heat medium is cooled by heat exchange in the refrigerant circuit 16, and while the vehicle is running, the battery 12 is cooled by cooling the heat medium using the radiator. As a result, the temperature of the battery 12 falls within the allowable range. In this case, performing pre-temperature control can reduce power consumption while the vehicle is running.

[0040] Note that even if a passenger is scheduled to board the vehicle, if the battery 12 is not being externally charged, the control unit 11 predicts the power consumption required to lower the temperature of the battery 12 to the upper limit of the allowable range of 40° C. or less when the vehicle arrives at the destination. Then, if the value obtained by subtracting the running power from the remaining battery charge is greater than the power consumption required to regulate the temperature of the battery 12, the control unit 11 performs pre-temperature regulation in the same manner as described above.

[0041] Furthermore, if the value obtained by subtracting the driving power from the remaining battery charge is smaller than the power consumption required for temperature control of the battery 12, the control unit 11 notifies the occupant to charge the battery. For example, this is displayed on an information display terminal such as a smartphone. As a result, if external charging of the battery 12 is started, the control unit 11 performs pre-temperature control in the same manner as described above.

[0042] On the other hand, if external charging of the battery 12 is not started, the temperature of the battery 12 is adjusted while the vehicle is running.

[0043] In this case, in the battery temperature regulation in step S4 of Fig. 2, when it is determined that the temperature of the battery 12 exceeds the upper limit of the optimum range of 30°C while the vehicle is running, the temperature of the battery 12 is regulated by cooling the battery 12. For example, the battery 12 is cooled by cooling the heat medium using a radiator. At this time, the battery 12 is cooled so that the temperature of the battery 12 does not fall below the lower limit of the optimum range. As a result, the temperature of the battery 12 falls within the optimum range.

[0044] In the battery temperature control in step S6 of Fig. 2, when it is determined that the temperature of the battery 12 exceeds the upper limit of the allowable range of 40°C while the vehicle is running, the temperature of the battery 12 is controlled by cooling the battery 12. For example, the battery 12 is cooled by cooling the heat medium using a radiator. At this time, the battery 12 is cooled so that the temperature of the battery 12 does not fall below the lower limit of the allowable range. As a result, the temperature of the battery 12 falls within the allowable range.

[0045] Regardless of whether or not the pre-temperature adjustment is performed, the power consumption required for the battery temperature adjustment can be reduced by not performing the battery temperature adjustment in step S7 of FIG.

[0046] As described above, battery temperature control can be performed either when pre-temperature control is performed or when temperature control is performed while the vehicle is running, but when pre-temperature control is performed, the power consumption of battery 12 while the vehicle is running can be reduced, which is effective in extending the vehicle's driving distance.

[0047] Figure 3 is an explanatory diagram showing a specific example of temperature change of the battery 12 when the battery temperature control shown in Figure 2 is executed. In Figure 3, the presence of a passenger separates the period into pre-temperature control and temperature control during driving, and the threshold value TH separates the period into short-term driving and long-term driving. A specific example is shown in which pre-temperature control is not performed for short-term driving, and a specific example is shown in which pre-temperature control is performed for long-term driving. In Figure 3, the optimal range of battery temperature is 20°C to 30°C, and the allowable range of battery temperature is 0°C to 40°C.

[0048] As shown in Fig. 3, when a long-term drive is to be performed (step S3 in Fig. 2: YES), the battery 12 is heated by pre-temperature control to keep the temperature a of the battery 12 within the optimum range. Then, when it is determined that the temperature of the battery 12 will exceed 30°C, which is the upper limit of the optimum range, the battery 12 is cooled so that the temperature does not fall below 20°C (step S4 in Fig. 2). As a result, when a long-term drive is to be performed, the temperature a of the battery 12 stays within the optimum range of 20°C to 30°C.

[0049] When traveling for a short time (step S3 in FIG. 2: NO), the temperature of the battery 12 is controlled by cooling the battery 12 when it is determined that the temperature will exceed 40°C, which is the upper limit of the allowable range, while the vehicle is traveling without performing pre-temperature control (step S6 in FIG. 2). As a result, in this example, the temperature b of the battery 12 drops. Note that in this example, the battery 12 is cooled so that the temperature of the battery 12 does not exceed 40°C. Then, when the vehicle arrives at the destination, the temperature b of the battery 12 reaches near the upper limit of 40°C. As a result, when traveling for a short time, the temperature of the battery 12 falls within the allowable range of 0°C to 40°C.

[0050] <Battery Temperature Control of Second Embodiment> The temperature of the battery 12 needs to be maintained within an optimal range while the vehicle is traveling in order to prevent deterioration and performance degradation of the battery 12. On the other hand, maintaining the temperature of the battery 12 within an acceptable range when the vehicle arrives at its destination has little effect on deterioration and performance of the battery 12. Therefore, if the temperature of the battery 12 is maintained within an optimal range until the vehicle arrives at its destination, the vehicle will arrive at its destination with surplus thermal energy compared to maintaining the temperature of the battery 12 within an acceptable range when the vehicle arrives at its destination. In this case, the thermal energy is not used after the vehicle arrives at its destination, resulting in a large loss of thermal energy after the vehicle arrives at its destination. Therefore, it is preferable to perform battery temperature control to reduce energy consumption while maintaining the temperature of the battery 12 within an optimal range. Therefore, the control unit 11 can execute the battery temperature control shown in FIG. 4 .

[0051] FIG. 4 is a flowchart showing an example of the battery temperature regulation control by the control unit 11.

[0052] 4, the control unit 11 acquires vehicle driving information (S1). The driving information includes, for example, the remaining battery charge, the battery temperature, the outside air temperature, the driving distance, and the driving time. This information can be acquired based on departure point information, destination information, and route information obtained from learning data, settings for the navigation device 19, data acquired from the cloud, data acquired through communications with other vehicles, data acquired from infrastructure facilities, etc.

[0053] Next, the control unit 11 predicts the temperature rise of the battery based on the driving information, and predicts the temperature of the battery 12 when the vehicle arrives at the destination based on the predicted temperature rise of the battery (S2). Specifically, the control unit 11 predicts the timing of battery charge / discharge requests until the vehicle arrives at the destination. Then, based on the battery temperature and the amount of heat generated by the battery 12 during driving due to charging and discharging, the control unit 11 predicts the temperature rise of the battery if temperature control is not performed from the time the vehicle starts driving until it arrives at the destination, and predicts the temperature of the battery 12 when the vehicle arrives at the destination based on the prediction result.

[0054] Next, the control unit 11 determines, based on the prediction result of step S2, whether or not the temperature of the battery 12 will exceed the upper limit of the allowable range of 40° C. when the vehicle arrives at the destination (S3).

[0055] If the control unit 11 determines that the temperature of the battery 12 will exceed 40°C, the upper limit of the allowable range, when the vehicle arrives at the destination (S3: YES), the control unit 11 executes battery temperature adjustment control to adjust the temperature of the battery 12 so that the temperature of the battery 12 falls within the optimum range in a first time slot after the vehicle starts traveling and so that the temperature of the battery 12 falls within the allowable range in a second time slot after the first time slot and until the vehicle arrives at the destination (S4). That is, in step S4, the control unit 11 executes battery temperature management control to manage the temperature of the battery 12 so that the temperature of the battery 12 falls within the optimum range in the first time slot and so that the temperature of the battery 12 falls within the allowable range in the second time slot.

[0056] Specifically, based on the progression of the battery temperature rise predicted in step S2, the control unit 11 determines the vehicle's driving time until the temperature of the battery 12 reaches the starting point of the rise in temperature when the temperature of the battery 12 rises from the upper limit of the optimal range of 30°C while the vehicle is driving and reaches the upper limit of the acceptable range of 40°C when the vehicle arrives at the destination.

[0057] Then, in a first time period from when the vehicle starts traveling until the time when the vehicle's traveling time reaches the rising start point, battery temperature control is executed so that the temperature of battery 12 falls within the first temperature range and the battery temperature at the rising start point reaches the upper limit of the optimal range of 30°C. On the other hand, in a second time period from when the vehicle reaches the destination after the first time period, battery temperature control is not executed. As a result, in the first time period, the temperature of battery 12 falls within the optimal range and the battery temperature at the rising start point reaches the upper limit of the optimal range of 30°C, and in the second time period, the temperature of battery 12 falls within the allowable range and reaches the upper limit of the allowable range of 40°C when the vehicle arrives at the destination.

[0058] If the control unit 11 determines that the temperature of the battery 12 when the vehicle arrives at the destination will not exceed the upper limit of the allowable range (S3: NO), it stops executing battery temperature management control based on the target temperature and temperature management range (S5). As a result, the temperature of the battery 12 falls within the allowable range during the second time period. At this time, the control unit 11 may stop the operation of the circulation pump 14 to stop the circulation of the heat medium in the battery temperature control circuit 10. Alternatively, the control unit 11 may simply circulate the heat medium through the battery temperature control circuit 10 without managing the battery temperature based on the target temperature and temperature management range. For example, the control unit 11 may circulate the heat medium through the battery temperature control circuit 10 without cooling the battery in the radiator or exchanging heat with the refrigerant. This eliminates temperature variations between the battery cells of the battery 12 and prevents deterioration of the battery 12.

[0059] As described above, by managing the temperature of the battery 12 so that it is within an acceptable range when the vehicle arrives at the destination, unnecessary temperature control of the battery 12 within a range that does not affect the deterioration or performance of the battery 12 is not performed, thereby reducing energy consumption.

[0060] In particular, since battery temperature control is not executed during the second time slot, energy consumption can be effectively reduced. Note that although the present embodiment describes an example in which battery temperature control is not executed during the second time slot, battery temperature control may be executed during the second time slot.

[0061] 4, the temperature of the battery 12 may be controlled in accordance with a temperature control plan created for the battery 12 before the occupant gets on board, or may be controlled by monitoring the temperature of the battery 12 while the vehicle is running without creating a temperature control plan. In either case, the temperature of the battery 12 is controlled after identifying the running time of the vehicle until it reaches the above-mentioned starting point of the temperature rise.

[0062] When creating a temperature control plan for the battery 12, for example, the temperature control plan for the battery 12 is created so that the temperature of the battery 12 falls within a first temperature range during a first time period and the battery temperature at the start of the temperature rise reaches the upper limit of the optimal range of 30°C. The temperature of the battery 12 is then controlled in accordance with the created temperature control plan. As a result, the temperature of the battery 12 falls within the optimal range during the first time period and the battery temperature at the start of the temperature rise reaches the upper limit of the optimal range of 30°C, and in the second time period, the temperature of the battery 12 falls within an acceptable range even without temperature control of the battery 12, and reaches the upper limit of the acceptable range of 40°C when the vehicle arrives at the destination. Note that if the timing of the charge / discharge request for the battery 12 changes, the temperature control plan is recreated.

[0063] If a temperature control plan for the battery 12 is not created, for example, the temperature of the battery 12 is monitored and the temperature of the battery 12 is controlled while the vehicle is running so that the temperature of the battery 12 falls within the optimum range in the first time slot and the temperature of the battery 12 at the start of the temperature rise reaches the upper limit of the optimum range, 30°C. Note that if temperature control during running is not required by performing pre-temperature control, which will be described later, only the temperature of the battery 12 is monitored in the first time slot. As a result, the temperature of the battery 12 falls within the optimum range in the first time slot and the battery temperature at the start of the temperature rise reaches the upper limit of the optimum range, 30°C. In the second time slot, the temperature of the battery 12 falls within the allowable range even without temperature control of the battery 12, and reaches the upper limit of the allowable range, 40°C, by the time the vehicle arrives at the destination.

[0064] In either case where a temperature control plan for battery 12 is created or where a temperature control plan for battery 12 is not created, the temperature control of battery 12 may be performed in real time by monitoring the temperature of battery 12 while the vehicle is running, or may be performed as pre-temperature control before passengers board the vehicle.

[0065] For example, the control unit 11 determines whether to perform pre-temperature control by determining whether an occupant is scheduled to board the vehicle. Whether an occupant is scheduled to board the vehicle can be determined, for example, from activation of the vehicle system before the occupant boards the vehicle via a remote control operation from outside the vehicle, activation of the vehicle system before the occupant boards the vehicle via a timer, or learning data based on the behavioral patterns of the vehicle owner.

[0066] The control unit 11 then performs pre-temperature control when an occupant is scheduled to board the vehicle and the battery 12 is being externally charged. The pre-temperature control can be performed together with pre-air conditioning, which pre-conditions the interior of the vehicle.

[0067] In the battery temperature control in step S4 of FIG. 4 , pre-temperature control is performed to keep the temperature of the battery 12 within the optimal range. Therefore, even if temperature control of the battery 12 is not performed while the vehicle is traveling, if the temperature of the battery 12 falls within the optimal range in the first time slot and then falls within the allowable range in the second time slot, pre-temperature control is performed so that the temperature of the battery 12 reaches the upper limit of the allowable range, 40°C, when the vehicle arrives at the destination. For example, in pre-temperature control, the temperature of the battery 12 is controlled by cooling or heating the heat medium through heat exchange in the refrigerant circuit 16. As a result, in the first time slot, the temperature of the battery 12 falls within the optimal range and reaches the upper limit of the optimal range, 30°C, at the start of the temperature rise. In the second time slot, the temperature of the battery 12 falls within the allowable range without temperature control of the battery 12, and reaches the upper limit of the allowable range, 40°C, when the vehicle arrives at the destination. In this case, temperature control is not required while the vehicle is traveling, thereby reducing power consumption during traveling.

[0068] On the other hand, in the battery temperature control of step S4 in FIG. 4 , even if pre-temperature control is performed to keep the temperature of the battery 12 within the optimal range, if the temperature of the battery 12 falls within the optimal range in the first time slot but does not fall within the allowable range in the second time slot, pre-temperature control is performed so that the temperature of the battery 12 falls to 20°C, the lower limit of the optimal range. Furthermore, in the first time slot, the temperature of the battery 12 is controlled by cooling the battery 12 when it is determined that the temperature of the battery 12 exceeds 30°C, the upper limit of the optimal range. At this time, in the first time slot, the temperature of the battery 12 is controlled so that the temperature of the battery 12 does not fall below 20°C, the lower limit of the optimal range. In addition, the temperature of the battery 12 is controlled so that the temperature of the battery 12 reaches 30°C, the upper limit of the optimal range, at the start of the rise. For example, in the pre-temperature control, the temperature of the battery 12 is controlled by cooling or heating the heat medium through heat exchange in the refrigerant circuit 16, and the battery 12 is cooled by cooling the heat medium using a radiator while the vehicle is running. As a result, in the first time slot, the temperature of the battery 12 falls within the optimum range and reaches the upper limit of the optimum range of 30° C. at the start of the rise, and in the second time slot, the temperature of the battery 12 falls within the allowable range even without temperature control of the battery 12, and reaches the upper limit of the allowable range of 40° C. when the vehicle arrives at the destination. In this case, by performing pre-temperature control, it is possible to reduce power consumption during driving.

[0069] Note that even if a passenger is scheduled to board the vehicle, if the battery 12 is not being externally charged, the control unit 11 predicts the power consumption required to lower the temperature of the battery 12 to the upper limit of the allowable range of 40° C. or less when the vehicle arrives at the destination. Then, if the value obtained by subtracting the running power from the remaining battery charge is greater than the power consumption required to regulate the temperature of the battery 12, the control unit 11 performs pre-temperature regulation in the same manner as described above.

[0070] Furthermore, if the value obtained by subtracting the driving power from the remaining battery charge is smaller than the power consumption required for temperature control of the battery 12, the control unit 11 notifies the occupant to charge the battery. For example, this is displayed on an information display terminal such as a smartphone. As a result, if external charging of the battery 12 is started, the control unit 11 performs pre-temperature control in the same manner as described above.

[0071] On the other hand, if external charging of the battery 12 is not started, the temperature of the battery 12 is adjusted while the vehicle is running.

[0072] In this case, in the battery temperature control in step S4 of FIG. 4 , during the first time slot, the temperature of the battery 12 is monitored in real time, and when it is determined that the temperature of the battery 12 exceeds the upper limit of the optimal range of 30° C. while the vehicle is traveling, the temperature of the battery 12 is controlled by cooling the battery 12. At this time, during the first time slot, the temperature of the battery 12 is controlled so that the temperature of the battery 12 does not fall below the lower limit of the optimal range of 20° C. In addition, the temperature of the battery 12 is controlled while the vehicle is traveling so that the temperature of the battery 12 reaches the upper limit of the optimal range of 30° C. at the start of the temperature rise. For example, the battery 12 is cooled by cooling the heat medium using a radiator. As a result, during the first time slot, the temperature of the battery 12 falls within the optimal range and reaches the upper limit of the optimal range of 30° C. at the start of the temperature rise. During the second time slot, the temperature of the battery 12 falls within the allowable range without temperature control of the battery 12, and reaches the upper limit of the allowable range of 40° C. by the time the vehicle arrives at the destination.

[0073] In step S5 of FIG. 4, the battery temperature is not adjusted, thereby reducing the power consumption required for adjusting the battery temperature.

[0074] As described above, battery temperature control can be performed either when pre-temperature control is performed or when temperature control is performed while the vehicle is running, but when pre-temperature control is performed, the power consumption of battery 12 while the vehicle is running can be reduced, which is effective in extending the vehicle's driving distance.

[0075] FIG. 5 is an explanatory diagram showing a specific example of the temperature change of the battery 12 when the battery temperature control shown in FIG. 4 is executed. Note that FIG. 5 shows a specific example when pre-temperature control is executed. In FIG. 5, the pre-temperature control start time before the occupant gets on board is set to 0, and the occupant's on-board time is set to t1. The temperature of the battery 12 when the vehicle starts running from t1 and arrives at the destination at t2 is set to temperature a, the temperature of the battery 12 when the vehicle starts running from t1 and arrives at the destination at t3 is set to temperature b, and the temperature of the battery 12 when the vehicle starts running from t1 and arrives at the destination at t4 is set to temperature c. In FIG. 5, the optimal range of the battery temperature is 20°C to 30°C, and the allowable range of the battery temperature is 0°C to 40°C.

[0076] As shown in Fig. 5, if the vehicle starts traveling at t1 and arrives at the destination at t2, it can be predicted that the temperature a of the battery 12 will not exceed the upper limit of the allowable range of 40°C when the vehicle arrives at the destination (step S3 in Fig. 4: NO). Furthermore, since the traveling time is short and the impact on the battery 12 is small, temperature control of the battery 12 is not performed (step S5 in Fig. 4). In this case, the power consumption required for battery temperature control can be reduced.

[0077] On the other hand, if the vehicle starts traveling at t1 and arrives at the destination at t3, it can be predicted that the temperature b of the battery 12 will exceed the upper limit of the allowable range of 40°C when the vehicle arrives at the destination (step S3 in Figure 4: YES).

[0078] Therefore, based on the predicted temperature rise trend of the battery 12, the vehicle's running time t11 until the battery temperature reaches the starting point s1 of the rise in temperature is determined when the temperature b of the battery 12 rises from the upper limit of the optimal range of 30°C while the vehicle is running and reaches the upper limit of the allowable range of 40°C when the vehicle arrives at the destination.

[0079] Then, during the first time period t1 to t11, which is the time when the vehicle's running time reaches the rising starting point s1, battery temperature control is performed so that the temperature of the battery 12 falls within the optimum range and the temperature b of the battery 12 at the rising starting point s1 reaches the upper limit value of the optimum range, 30°C (step S4 in Figure 4).

[0080] On the other hand, the battery temperature control is not executed in a second time period t11 to t3, which is from the time t11 when the vehicle reaches the rising start point s1 until the time t3 when the vehicle arrives at the destination.

[0081] In this example, if pre-temperature control is performed to keep the temperature of the battery 12 within the optimal range before the passenger gets in, the temperature of the battery 12 will stay within the optimal range during the first time period t1 to t11, and the temperature b of the battery 12 at the rising starting point s1 will reach the upper limit of the optimal range, 30°C, even without temperature control of the battery 12 while the vehicle is traveling. Furthermore, during the second time period t11 to t3, the upper limit of the allowable range, 40°C, will be reached by the time the vehicle arrives at the destination, even without temperature control of the battery 12. Therefore, in this example, only pre-temperature control is performed to cool the battery 12 so that the temperature of the battery 12 stays within the optimal range before the passenger gets in. In this way, pre-temperature control eliminates the need for temperature control while the vehicle is traveling, thereby reducing power consumption while traveling.

[0082] Furthermore, if the vehicle starts traveling at t1 and arrives at the destination at t4, it can be predicted based on the temperature rise of the battery 12 that the temperature c of the battery 12 will exceed the upper limit of the allowable range of 40°C when the vehicle arrives at the destination (step S3 in Figure 4: YES).

[0083] Therefore, based on the predicted temperature rise trend of the battery 12, the vehicle's running time t22 until the battery temperature rise starting point s2 while the vehicle is running is determined when the temperature c of the battery 12 rises from the upper limit value of the optimal range of 30°C while the vehicle is running and reaches the upper limit value of the allowable range of 40°C when the vehicle arrives at the destination.

[0084] Then, during the first time period t1 to t22, which is the time when the vehicle's running time reaches the rising starting point s2 at time t22, battery temperature control is performed so that the temperature of the battery 12 falls within the optimal range and the temperature c of the battery 12 at the rising starting point s2 reaches the upper limit value of the optimal range, 30°C (step S4 in Figure 4).

[0085] On the other hand, the battery temperature control is not executed in a second time period t22 to t4, which is from the time t22 when the vehicle reaches the ascending starting point s2 until the time t4 when the vehicle arrives at the destination.

[0086] In this example, even if pre-temperature control is performed to cool the battery 12 before the passengers get in, the temperature of the battery 12 exceeds the upper limit of the allowable range of 40°C when the vehicle arrives at the destination. Therefore, in this example, pre-temperature control is performed to lower the temperature of the battery 12 to 20°C, the lower limit of the optimal range, before the passengers get in, and temperature control of the battery 12 is also performed while the vehicle is traveling. As a result, during the first time period t1 to t22, the temperature of the battery 12 falls within the optimal range, and the temperature c of the battery 12 at the rising starting point s2 reaches the upper limit of the optimal range of 30°C. Furthermore, during the second time period t22 to t4, the upper limit of the allowable range of 40°C is reached when the vehicle arrives at the destination, even without temperature control of the battery 12. This reduces power consumption during traveling compared to when temperature control is performed only while the vehicle is traveling.

[0087] In this embodiment, an example has been described in which battery temperature control is performed so that the temperature of the battery 12 reaches the upper limit of the allowable range when the vehicle arrives at the destination. However, if the temperature of the battery 12 is within the allowable range when the vehicle arrives at the destination, it is not necessary to perform battery temperature control so that the temperature reaches the upper limit. In other words, if it is necessary to heat the battery 12 so that the temperature of the battery 12 reaches the upper limit of the allowable range, it is preferable to control the temperature within the allowable range without heating the battery 12. This can suppress an increase in energy consumption.

[0088] [Advantages of the Present Embodiment] (a1) A vehicle battery temperature control system 1 includes a battery 12 mounted on a vehicle, a battery temperature control unit that controls the temperature of the battery 12, and a control unit 11 that can execute battery temperature control to control the temperature of the battery, wherein the control unit 11 predicts vehicle driving information from when the vehicle departs from a current location to when the vehicle arrives at a destination, determines whether the vehicle driving time exceeds a threshold based on the predicted driving information, and executes first battery temperature control if it determines that the vehicle driving time exceeds the threshold, and executes second battery temperature control if it determines that the vehicle driving time does not exceed the threshold. Thus, by changing the battery temperature control depending on whether the battery 12 is used for a long time or a short time, it is possible to control the temperature of the battery 12 within an optimal range that takes into account deterioration of the battery 12 when the battery 12 is used for a long time, while suppressing an increase in power consumption that would be caused by unnecessarily controlling the temperature within the optimal range when the battery 12 is used for a short time.

[0089] Note that the first battery temperature control is an example of battery temperature control that is performed to keep the battery temperature within an optimal range, and the second battery temperature control is an example of battery temperature control that keeps the battery temperature within an acceptable range. However, the aspects of the first battery temperature control and the second battery temperature control do not have to be limited to the aspects of this embodiment; for example, the first battery temperature control may be configured so that the proportion of battery temperatures that stay within the optimal range is higher than the second battery temperature control.

[0090] (a2) In the first battery temperature control, the control unit 11 controls the battery temperature so that the battery temperature falls within an optimal range, which is a first temperature range, and in the second battery temperature control, the control unit 11 controls the battery temperature so that the battery temperature falls within an allowable range, which is a second temperature range that is wider than the first temperature range. Controlling the battery temperature so that the battery temperature falls within the optimal range, which is the first temperature range, has less impact on battery degradation or performance than controlling the battery temperature so that the battery temperature falls within the allowable range, which is the second temperature range. Therefore, when the battery 12 is used for a long period of time, the temperature of the battery 12 is controlled within the optimal range taking into account deterioration of the battery 12, and when the battery 12 is used for a short period of time, it is possible to suppress an increase in power consumption caused by unnecessary temperature control within the optimal range.

[0091] (a3) In the second battery temperature control, the control unit 11 determines whether the temperature of the battery 12 exceeds 40° C., which is the upper limit of the allowable range that is the second temperature range, and executes the battery temperature control when it determines that the temperature of the battery 12 exceeds 40° C., which is the upper limit of the allowable range that is the second temperature range. Therefore, when the battery 12 is used for a short period of time, the temperature of the battery 12 is adjusted so that the upper limit of the allowable range, 40° C., thereby suppressing deterioration of the battery 12 and suppressing an increase in power consumption.

[0092] (b1) A vehicle battery temperature control system 1 includes a battery 12 mounted on a vehicle, a battery temperature control unit that controls the temperature of the battery 12, and a control unit 11 capable of executing battery temperature control to control the temperature of the battery, wherein the control unit 11 executes battery temperature control so that the battery temperature falls within an optimal range, which is a first temperature range, during a first time period after the vehicle starts traveling, and so that the battery temperature falls within an acceptable range, which is a second temperature range that is wider than the optimal range, which is the first temperature range, during a second time period after the first time period and until the vehicle arrives at its destination. Thus, by managing the temperature of the battery 12 so that it falls within the acceptable range when the vehicle arrives at its destination, unnecessary temperature control of the battery 12 is not performed within a range that does not affect the deterioration or performance of the battery 12, thereby reducing energy consumption.

[0093] (b2) The control unit 11 executes battery temperature control so that the temperature of the battery 12 falls within the second temperature range when the vehicle arrives at the destination, and reaches the upper limit of the allowable range, 40° C., which is the second temperature range. Therefore, by managing the temperature of the battery 12 so that the upper limit of the allowable range, 40° C., is reached when the vehicle arrives at the destination, unnecessary temperature control of the battery 12 within a range that does not affect the deterioration or performance of the temperature-controlled battery 12 is not performed, thereby reducing energy consumption.

[0094] (b3) The control unit 11 predicts the temperature rise trend of the battery 12 from when the vehicle starts traveling until it arrives at the destination, and determines whether the temperature of the battery 12 exceeds the upper limit of 40°C of the allowable range, which is the second temperature range, when the temperature of the battery 12 rises from when the vehicle starts traveling until it arrives at the destination based on the predicted rise trend. If the temperature of the battery 12 exceeds the upper limit of 40°C of the allowable range, which is the second temperature range, based on the predicted rise trend, the control unit 11 determines whether the temperature of the battery 12 rises from the upper limit of 30°C of the optimal range, which is the first temperature range, during the traveling of the vehicle and arrives at the destination. The system specifies the vehicle running time until the battery 12 temperature reaches the rising start point when the upper limit of the allowable range, 40°C, which is the second temperature range, is reached when the temperature reaches the rising start point, and performs battery temperature control so that the temperature of the battery 12 falls within the optimal range, which is the first temperature range, and the battery temperature at the rising start point reaches the upper limit of the optimal range, 30°C, which is the first temperature range, during a first time period after the vehicle starts running and until the vehicle running time reaches the rising start point, but does not perform battery temperature control during a second time period after the first time period and until the vehicle arrives at the destination. Therefore, by not performing temperature control of the battery 12 during the second time period, it is possible to reduce the power required for temperature control of the battery 12, and thereby suppress energy consumption.

[0095] The present invention has been described above by showing preferred embodiments, but it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0096] 1: Vehicle battery temperature control system 10: Battery temperature control circuit 11: Control unit 12: Battery 13: Battery temperature control unit 14: Circulation pump 15: Heat medium heating device 16: Refrigerant circuit

Claims

1. A vehicle battery temperature control system comprising a battery mounted on a vehicle, a battery temperature control unit that controls the temperature of the battery, and a control unit capable of executing battery temperature control to control the temperature of the battery, wherein the control unit executes battery temperature control so that the temperature of the battery falls within a first temperature range during a first time period after the vehicle starts to travel, and so that the temperature of the battery falls within a second temperature range wider than the first temperature range during a second time period after the first time period until the vehicle arrives at its destination.

2. The vehicle battery temperature control system according to claim 1, characterized in that the control unit executes battery temperature control so that the battery temperature falls within the second temperature range when the vehicle arrives at the destination.

3. The vehicle battery temperature control system according to claim 2, wherein the control unit predicts a rise in battery temperature from when the vehicle starts traveling to when the vehicle arrives at the destination, determines whether the battery temperature will exceed an upper limit of a second temperature range if the battery temperature rises from when the vehicle starts traveling to when the vehicle arrives at the destination based on the predicted rise in temperature, and if the battery temperature exceeds the upper limit of the second temperature range, specifies a vehicle traveling time until the battery temperature reaches a start point of rise in battery temperature based on the predicted rise in temperature, in which the battery temperature rises from the upper limit of a first temperature range while the vehicle is traveling and reaches the upper limit of the second temperature range when the vehicle arrives at the destination, and performs battery temperature control so that the battery temperature falls within the first temperature range and the battery temperature at the start point of rise reaches the upper limit of the first temperature range during a first time period after the vehicle starts traveling until the vehicle traveling time reaches the start point of rise in temperature, and does not perform battery temperature control during a second time period after the first time period until the vehicle arrives at the destination.

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