JP6369429B2 - Battery cooling control method - Google Patents

Description

  The present invention relates to a battery cooling control method, and more particularly to a battery cooling control method having an intake air temperature sensor for detecting an outside air temperature supplied to the battery.

  When the battery is charged and discharged, the battery temperature rises, and the battery characteristics change accordingly, so that appropriate cooling is required.

  In Patent Document 1, as a pre-ventilation control performed in a stop mode before an operation for starting a vehicle system by a driver is performed, the battery cooling is performed when the temperature in the passenger compartment or the intake air temperature is lower than the battery temperature. It is stated that the fan is driven.

  Patent Document 2 discloses disposing an intake air temperature sensor and an exhaust gas temperature sensor outside a battery storage case as a method of detecting a failure of a fan for cooling a power supply device. Here, when the fan for cooling the power supply device breaks down, both the intake temperature sensor and the exhaust temperature sensor detect the outside air temperature, and the fact that the difference between the detected values of both temperature sensors becomes small is utilized.

JP 2010-163095 A JP 2005-293971 A

  The cooling of the air-cooled battery is performed by comparing the outside air temperature and the battery temperature, for example, when the outside air temperature is lower than the battery temperature, driving the battery cooling fan to supply the outside air to the battery. In this case, if the intake air temperature sensor that detects the outside air temperature supplied to the battery becomes abnormal, the battery cooling fan is driven in a state of being deviated from the actual intake air temperature. Therefore, a battery cooling control method that can detect abnormality of the intake air temperature sensor is desired.

  A battery cooling control method according to an embodiment of the present invention is a battery cooling control method having an outside air intake port and an exhaust port for cooling a battery, and obtains an output value of an intake air temperature sensor provided at the intake port. If the time change in the output value of the intake air temperature sensor is greater than or equal to a predetermined value, the intake air temperature sensor is normal.If the time change in the output value of the intake air temperature sensor is less than the predetermined value, outside air is taken into the battery from the intake port. When the fan that is supplied and exhausted from the exhaust port is driven and the time change of the output value of the intake air temperature sensor exceeds a predetermined value after the fan is driven, the intake air temperature sensor is assumed to be normal, and the output value of the intake air temperature sensor It is assumed that the intake air temperature sensor is abnormal when the time change of the time remains below a predetermined value.

  According to the battery cooling control method having the above-described configuration, the abnormality of the intake air temperature sensor is detected based on the temporal change in the output value of the intake air temperature sensor before and after the fan is driven. That is, since the outside air temperature is lower than the temperature of the battery, when the outside air is sent to the battery by the fan, the temperature of the battery inlet changes to the low temperature side. Nevertheless, when the output value of the intake air temperature sensor does not fluctuate, it is possible to detect an abnormality in the intake air temperature sensor.

  According to the battery cooling control method configured as described above, it is possible to detect abnormality of the intake air temperature sensor.

1 is a configuration diagram of a battery cooling system to which a battery cooling control method according to an embodiment of the present invention is applied. It is detail drawing of the battery which is a control object of the cooling control method of the battery of embodiment which concerns on this invention. It is a flowchart which shows the process sequence of the cooling control method of the battery in embodiment which concerns on this invention. FIG. 4 is a time chart showing the relationship among the output value of the intake air temperature sensor, the output value of the battery temperature sensor, and the fan drive timing with respect to FIG. 3. It is a figure which shows the process sequence when performing battery cooling control when another intake air temperature sensor is abnormal as another embodiment. 6 is a time chart showing the relationship between battery temperature change and fan drive control.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Below, the battery mounted in a vehicle is described as a battery, However, This is an illustration for description, Comprising: The battery used for another use may be sufficient. As the battery, a battery stack in which a plurality of single cells are stacked will be described. However, this is an example for explanation, and any battery having a cooling inlet and an outlet may be used. The arrangement of the air intake port, the air exhaust port, the intake port, the exhaust port and the like in the following is an example for explanation, and can be appropriately changed depending on the specifications of the battery cooling system to which the battery cooling control method is applied. . Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a configuration diagram of a battery cooling system 10 that cools a battery mounted on a vehicle. The battery cooling system 10 includes a battery pack 12 and a control device 50 that executes a battery cooling control method for the battery stack 30 included in the battery pack 12. The battery pack 12 includes a pack case 14, a plurality of battery stacks 30 housed in the pack case 14, and fans 22 and 24 for battery cooling.

  The battery pack 12 is a power source that is disposed below the floor of the rear seat of the vehicle and connected to a rotating electrical machine (not shown). The pack case 14 is a case body having a connecting portion for shaping the outer shape of the battery pack 12 and connecting and fixing it to the vehicle body. The pack case 14 is formed into a predetermined shape using a material having appropriate strength and electrical insulation. As the material, a metal such as an aluminum alloy whose surface is electrically insulated or a plastic can be used.

  The air intake ports 16 and 18 and the air discharge port 20 provided in the battery pack 12 drive the fan 22 and 24 for cooling the battery, thereby taking in and exhausting air in the vehicle interior as outside air. It is. In the example of FIG. 1, air intake ports 16 and 18 are provided at both ends in the longitudinal direction of the elongated battery pack 12, and an air discharge port 20 is provided at substantially the center in the longitudinal direction.

  The battery cooling fans 22 and 24 are battery cooling electric fans that are provided inside the pack case 14 and are driven or stopped under the control of the control device 50. Hereinafter, the fans 22 and 24 for cooling the battery are simply referred to as fans 22 and 24. The fans 22 and 24 are arranged at both ends of the battery pack 12 in the longitudinal direction corresponding to the arrangement of the air intake ports 16 and 18. When the fans 22 and 24 are driven, air in the vehicle compartment is taken into the pack case 14 from the air intake ports 16 and 18, flows through the battery stack 30, and then flows from the air discharge port 20 to the pack case 14. Is discharged outside. In FIG. 1, the flow of air inside the pack case 14 and the battery stack 30 when the fans 22 and 24 are driven is indicated by white arrows. When the fans 22 and 24 are stopped, the air flow indicated by these white arrows does not occur.

  The battery stack 30 is formed by stacking a plurality of unit cells 34 (see FIG. 2) into one. A plurality of battery stacks 30 are accommodated in the pack case 14. Assuming that the number of battery stacks 30 constituting the battery pack 12 is N and the number of unit cells 34 constituting the battery stack 30 is M, one battery pack 12 has a total of (M × N) unit cells 34. It is comprised including. For example, by connecting a plurality of unit cells 34 in the battery stack 30 in series, the terminal voltage of the battery stack 30 can be set to a high voltage M times the terminal voltage of the unit cell 34. By connecting a plurality of battery stacks 30 in the battery pack 12 in parallel, the current capacity of the battery pack 12 can be N times the current capacity of the battery stack 30. In this way, by connecting a plurality of single cells 34 in series and in parallel, the battery pack 12 can output a high voltage and a large current necessary for an electric device mounted on the vehicle. The above series-parallel method is an example for explanation, and other series-parallel methods may be used.

  In the example of FIG. 1, five battery stacks 30 a, 30 b, 30 c, 30 d, and 30 e are accommodated in the battery pack 12. Since these are all the same, FIG. 2 shows the configuration of the battery stack 30 as a representative of the battery stack 30b.

  The battery stack 30 includes a stack case 32, a plurality of unit cells 34 that are stacked inside the stack case 32, and a cooling flow path unit 36 that supplies outside air to the unit cells 34 for air cooling. The The stack case 32 is a rectangular parallelepiped housing extending in the stacking direction of the plurality of unit cells 34. The cooling flow path portion 36 may be configured as a part of the stack case 32. The stack case 32 and the cooling flow path portion 36 are formed into a predetermined shape using a material having appropriate strength and electrical insulation. As the material, a metal such as an aluminum alloy whose surface is electrically insulated or a plastic can be used.

  The single battery 34 is a chargeable / dischargeable secondary battery cell and is a lithium ion single battery. Instead, a nickel metal hydride battery can be used. The terminal voltage of the unit cell 34 is about 1 V to several V, but a desired high voltage can be obtained by connecting a plurality of them in series.

  The air inlet 38 is connected to the air outlets of the fans 22 and 24 through a pipe line such as an appropriate air duct, and the outside air sent from the air intake port 16 of the pack case 14 when the fans 22 and 24 are driven. It is an opening for sucking air into the battery stack 30. In the exhaust port 40, the outside air sucked from the intake port 38 flows toward each unit cell 34 via the cooling flow path 36, and the air that has been warmed by taking the heat of each unit cell 34 is removed from the cell stack 30. An opening for exhausting to the outside. The exhaust port 40 is connected to the air exhaust port 20 of the pack case 14 by a pipe line such as an appropriate exhaust duct. Hereinafter, the battery stack 30 will be described as a battery having the intake port 38 and the exhaust port 40.

  The intake air temperature sensor 42 is a temperature detection means that is disposed in the vicinity of the intake port 38 of the cooling flow path portion 36. When the fans 22 and 24 are driven, it is an intake air temperature detecting means for detecting the temperature of air sucked into the battery stack 30, but when the fans 22 and 24 are not driven, the air is not sucked. It becomes a means for detecting the temperature in the vicinity of the intake port 38 at. The output value of the intake air temperature sensor 42 is transmitted to the control device 50 via an appropriate signal line.

  The output value of the intake air temperature sensor 42 is a voltage. The control device 50 can convert the acquired voltage into the intake air temperature using a predetermined conversion relationship. When the intake air temperature sensor 42 is operating normally, the output value of the intake air temperature sensor 42 is a voltage corresponding to the temperature of the intake port 38, so this may be considered as the intake air temperature. When the operation of the intake air temperature sensor 42 is abnormal, the output value of the intake air temperature sensor 42 becomes a voltage unrelated to the temperature of the intake port 38. In that case, even if the output value of the intake air temperature sensor 42 is converted into temperature, the temperature of the intake port 38 is not correctly reflected. In some cases, the output value of the intake air temperature sensor 42 may become constant at the power supply voltage or the GND voltage of the output circuit of the intake air temperature sensor 42. As the intake air temperature sensor 42, a temperature measuring element such as a thermistor is used.

  The battery temperature sensor 44 is a battery temperature detection unit that detects the temperature of the battery stack 30. The battery temperature sensor 44 is disposed outside or inside the stack case 32 of the battery stack 30 at a position suitable for detecting the temperature of the unit cell 34. Since the plurality of unit cells 34 are stacked, the intake port 38 is provided at one place. Therefore, the battery temperature of the unit cell 34 may vary depending on the distance from the intake port 38. Therefore, it is preferable to detect the battery temperature using a plurality of battery temperature sensors 44. In the example of FIG. 2, three battery temperature sensors 44 </ b> A, 44 </ b> C, and 44 </ b> B are arranged along the longitudinal center axis of the stack case 32. The output values of the battery temperature sensors 44A, 44C, 44B are transmitted to the control device 50 via appropriate signal lines. The number and arrangement of the battery temperature sensors described above are illustrative examples, and other numbers and arrangements may be used.

  The output values of the battery temperature sensors 44A, 44C, 44B are voltages. The control device 50 can convert the acquired voltage into a battery temperature using a predetermined conversion relationship. As such battery temperature sensors 44A, 44C, and 44B, a temperature measuring element such as a thermistor is used similarly to the intake air temperature sensor.

  Based on the detected values of the three battery temperature sensors 44A, 44C, and 44B, the battery temperature of the battery stack 30 as a whole is estimated. Typically, the detection value of the battery temperature sensor 44 </ b> C arranged at the substantially central position of the stack case 32 can be used as the battery temperature of the battery stack 30. Hereinafter, the battery temperature sensor 44C is simply referred to as a battery temperature sensor 44.

  Returning to FIG. 1, the control device 50 is connected to the intake air temperature sensor 42 and the battery temperature sensor 44 provided in each of the battery stacks 30 a to 30 e and the fans 22 and 24, and is stored in the battery pack 12. It is a computer that performs battery cooling control for the stack 30. As an example of cooling control, when the battery temperature exceeds a predetermined temperature for cooling the battery, the control device 50 drives the fans 22 and 24 when the intake air temperature is lower than the battery temperature, and the battery stack. 30 is cooled. This is the normal cooling control of the battery performed when each component of the battery cooling system 10 is normal.

  The control device 50 detects an abnormality in the intake air temperature sensor 42 in addition to performing normal cooling control of the battery. Further, when the intake air temperature sensor 42 is abnormal, the cooling control of the battery is performed as much as possible. The control device 50 includes a sensor output value acquisition processing unit 52 that acquires an output value of the intake air temperature sensor 42 and an output value of the battery temperature sensor 44, a fan drive processing unit 54, and an abnormality processing unit 56 of the intake air temperature sensor. And have.

  These functions are realized by causing the control device 50 whose software is a computer to execute each processing procedure. Specifically, these functions are realized by causing the control device 50, which is a computer, to execute each processing procedure by the battery cooling control program. A part of each function may be realized by hardware.

  The operation of the above configuration, in particular, the contents of each procedure of the battery cooling control method executed by the control device 50 will be described in more detail with reference to FIGS. FIG. 3 is a flowchart showing the procedure of the battery cooling control method. Each procedure corresponds to each processing procedure that the battery cooling control program causes the control device 50 to execute. The abnormality detection of the intake air temperature sensor 42 can be performed in several stages of operation of the vehicle. Here, the abnormality detection of the intake air temperature sensor 42 in the initial diagnosis when the vehicle starts will be described.

  When a start switch such as an ignition switch is turned on in the vehicle, each element of the vehicle control system is initialized, and a battery cooling control program is started. Examples of initialization of each element of the vehicle control system are initialization of various electronic control units, status confirmation of the system main relay, initialization of various registers, initialization of various actuators, and the like. Since the electric power necessary for the initialization is supplied from each battery stack 30 housed in the battery pack 12, the battery that is the battery stack 30 is discharged, and the battery temperature rises.

  When the battery cooling control program starts up, the output value of the intake air temperature sensor 42 is acquired (S10). This processing procedure is executed by the function of the sensor output value acquisition processing unit 52 in the control device 50. At this stage, the fans 22 and 24 are not driven and are in a stopped state. Therefore, the intake air temperature sensor 42 detects not the outside air temperature but the temperature inside the pack case 14 as the temperature of the intake port 38.

  Next, the control device 50 determines whether or not the time change of the acquired output value of the intake air temperature sensor 42 is less than a predetermined value (S12). Since the battery temperature rises due to the initialization of the vehicle control system, the internal temperature of the pack case 14 also varies. When the intake air temperature sensor 42 operates normally, the output value of the intake air temperature sensor 42 also changes reflecting the change in the internal temperature of the pack case 14. S12 is a processing procedure for proceeding to the next, assuming that there is a possibility of abnormality of the intake air temperature sensor 42 when the acquired output value hardly fluctuates and stays within the detection error of the intake air temperature sensor 42. .

  The time for obtaining the magnitude of the time change of the output value is a time necessary for the rise in the battery temperature due to the initialization to be reflected in the temperature of the intake port 38. For example, about 1 minute to 2 minutes after the start switch is turned on. The predetermined value set in advance is set based on the detection error of the intake air temperature sensor 42. For example, when the detection error of the intake air temperature sensor 42 is ± 10 mV corresponding to ± 1 ° C. in terms of temperature, the predetermined value is set to a value slightly larger than ± 10 mV. For example, ± 20 mV corresponding to ± 2 ° C. in terms of temperature is set as the predetermined value. In this example, if the output value of the intake air temperature sensor 42 fluctuates by ± 20 mV or more between about 1 minute and 2 minutes after the start switch is turned on, the determination of S12 is denied and the output value of the intake air temperature sensor 42 When the fluctuation of is less than ± 20 mV, the determination in S12 is affirmed. These values are illustrative examples, and can be appropriately changed according to the configuration of the battery pack 12 and the battery stack 30.

  If the determination in S12 is negative, the intake air temperature sensor 42 is operated normally (S20). When the intake air temperature sensor 42 is normal and there is no failure in other elements, the normal cooling control of the battery is executed. When S12 is positive, the fans 22 and 24 are driven (S14). This processing procedure is executed by the function of the fan drive processing unit 54 in the control device 50. When the fans 22, 24 are driven, outside air is taken into the pack case 14 from the air intake ports 16, 18, and is sucked into the battery stack 30 from the intake port 38 of each battery stack 30, so that the unit cell 34 is To be cooled. Here, the outside air is air in the vehicle compartment of the vehicle, and is cooler than the battery temperature rising due to the discharge. Although the battery temperature is lowered by the outside air being taken into the pack case 14, the temperature of the air inlet 38 is also lowered as compared with that before the fans 22 and 24 are driven.

FIG. 4 is a diagram showing the contents of S14. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the sensor output value. Time t = t ₀ is a time when the start switch of the vehicle is turned on, and time t = t _F is a timing when the fans 22 and 24 are driven. A characteristic line 60 is an output value of the intake air temperature sensor 42. Characteristic lines 62 and 64 are output values of the battery temperature sensor 44. When the start switch of the vehicle is turned on at time t = t ₀ and each element is initialized, the battery stack 30 is discharged to supply the electric power, and the battery temperature gradually rises with time. In FIG. 4, the output value of the intake air temperature sensor 42 is shown as a value higher than the output value of the battery temperature sensor 44, but this is an example for explanation.

When the fans 22 and 24 are driven at time t = t _F , the air in the vehicle interior of the vehicle is taken into the pack case 14 as outside air. Since the temperature in the passenger compartment is lower than the temperature of the battery stack 30 that generates heat due to charging and discharging, the battery stack 30 is cooled. As a result, the battery temperature starts to decrease from time t = t _F. At this time, since the intake port 38 of the battery stack 30 is also cooled, if the operation of the intake temperature sensor 42 is normal and the output value of the characteristic line 60 corresponds to the temperature of the intake port 38, the expected characteristic line 66 As shown, the output value of the intake air temperature sensor 42 should also decrease. However, in FIG. 4, the output value of the intake air temperature sensor 42 does not fluctuate before and after the fans 22 and 24 are driven as shown by the characteristic line 60 and remains a constant value.

  Returning to FIG. 3, after the fans 22 and 24 are driven, it is determined whether the temporal change in the output value of the intake air temperature sensor 42 remains below a predetermined value (S16). If the determination in S16 is affirmative, it is assumed that the intake air temperature sensor 42 is abnormal (S18). On the other hand, if the time change of the output value of the intake air temperature sensor 42 becomes equal to or greater than a predetermined value after driving the fans 22 and 24, the process proceeds to S20, and the intake air temperature sensor 42 is operated normally. This processing procedure is executed by the function of the abnormality processing unit 56 of the intake air temperature sensor in the control device 50. In the example of FIG. 4, the output value of the intake air temperature sensor 42 does not fluctuate before and after the fans 22 and 24 are driven, and both remain constant within a range of detection error, so that the intake air temperature sensor 42 is abnormal. The

  As shown in FIG. 4, the output value of the battery temperature sensor 44 varies before and after the fans 22 and 24 are driven. Therefore, it is preferable to add the fluctuation state of the output value of the battery temperature sensor 44 to the determination criterion of S16. For example, “when the output value of the battery temperature sensor 44 fluctuates more than a predetermined fluctuation range before and after driving the fans 22 and 24, but the time change of the output value of the intake air temperature sensor 42 remains below a predetermined value. The intake air temperature sensor 42 is abnormal. This improves the reliability of determining whether the intake air temperature sensor 42 is operating normally or abnormally.

  Note that when the vehicle starts, it is considered that the vehicle is left unattended, and the temperature in the pack case 14 is uniform if the vehicle is left for a long period of time. Therefore, the temperature of the battery stack 30 corresponding to the output value of the battery temperature sensor 44 and the temperature of the intake port 38 corresponding to the output value of the intake air temperature sensor 42 are considered to be substantially the same temperature. By utilizing this, when the vehicle is started after being left for a long period of time, the temperature of the battery stack 30 corresponding to the output value of the battery temperature sensor 44 and the intake port 38 corresponding to the output value of the intake air temperature sensor 42 are used. Compare the temperature with. As a result of the comparison, when the temperature difference is equal to or greater than a predetermined value, the intake air temperature sensor 42 is abnormal.

  In the above, the procedure regarding the abnormality detection of the intake air temperature sensor 42 in the initial diagnosis when the vehicle starts is described. When the vehicle is running, the driving wind enters the passenger compartment or the air conditioner is activated, and the air in the passenger compartment is at a comfortable temperature by the driver. The vehicle interior temperature is lower than the battery temperature of the battery stack 30 that is charged and discharged by operation. Even in this case, the abnormality of the intake air temperature sensor 42 can be detected using the procedure of FIG. In addition, when the vehicle charges the battery stack 30 from an external charging power source, the vehicle interior temperature is adjusted to an appropriate temperature by air conditioning, and the vehicle interior temperature is increased by charging. It is colder than. Even in this case, the abnormality of the intake air temperature sensor 42 can be detected using the procedure of FIG.

  The intake air temperature sensor 42 is not abnormal only by the determination in S12, and the steps S14 and S16 are performed because the intake air temperature sensor 42 provided in each battery stack 30 is one. In the example of FIG. 2, three battery temperature sensors 44 are provided in one battery stack 30. Two fans 22 and 24 are provided for one pack case 14. As described above, since a plurality of battery temperature sensors 44 and fans 22 and 24 are provided as elements used for battery cooling control, an abnormality of these elements can be detected by comparing state changes between the same elements. . On the other hand, since only one intake air temperature sensor 42 is provided for the battery stack 30, the procedure of S14 and S16 is followed to make a determination in two stages to determine the abnormality.

  FIG. 5 is an example of a procedure for performing the battery cooling control until the parts are replaced when the intake air temperature sensor 42 is abnormal. If the intake air temperature sensor 42 is abnormal in S18 of FIG. 3, the fans 22 and 24 are driven to cool the battery (S30). In the procedure of FIG. 3, the fans 22 and 24 are driven in S14. If the fans 22 and 24 are kept in this state, the driving state is continued as it is. When the driving of the fans 22 and 24 is stopped after the determination of S18, the fans 22 and 24 are driven again. And it is judged whether the output value of the battery temperature sensor 44 shows the fall of battery temperature (S32). If the result is negative, it indicates that the battery is not cooled even if the fans 22 and 24 are driven, so the driving of the fans 22 and 24 is stopped (S38). When S32 is positive, since the battery is cooled, the fans 22 and 24 are continuously driven (S34). Then, when the battery temperature indicating the output value of the battery temperature sensor 44 falls below a predetermined temperature, the driving of the fans 22 and 24 is stopped (S38). In this way, the battery cooling control can be performed for a period until the intake air temperature sensor 42 determined to be abnormal is replaced.

FIG. 6 is a diagram showing the contents of S32 to S38. In FIG. 6, the horizontal axis represents time, and the vertical axis represents the sensor output value. Time t = t ₁ is when the intake air temperature sensor 42 is determined to be abnormal in S18 and driving of the fans 22 and 24 is stopped, and time t = t _C is the time when the fans 22 and 24 are cooled for battery cooling in S30. Is when it is driven. A characteristic line 60 is an output value of the intake air temperature sensor 42. The characteristic line 70 is an example of the output value of the battery temperature sensor 44 in the period up to time t _F. The characteristic line 72 is an example of the output value of the battery temperature sensor 44 when the determination in S32 is negative. The characteristic line 74 is an example of the output value of the battery temperature sensor 44 when the determination of S32 is affirmative. The battery temperature corresponding to the output value continues to decrease with time, and becomes an output value corresponding to the predetermined temperature. At the time t = t _E , the driving of the fans 22 and 24 is stopped.

  Thereafter, when a change in the output value of the battery temperature sensor 44 indicating that the battery temperature rises occurs, the driving of the fans 22 and 24 is resumed with an appropriate hysteresis temperature margin, and S34, S36, and S38. Repeat the procedure. In this way, the battery cooling control can be performed even when the intake air temperature sensor 42 is abnormal.

  10 Battery cooling system, 12 Battery pack, 14 Pack case, 16, 18 Air intake port, 20 Air exhaust port, 22, 24 Fan, 30, 30a, 30b, 30c, 30d, 30e Battery stack (intake and exhaust port Battery), 32 stack case, 34 single cell, 36 cooling flow path section, 38 air inlet, 40 air outlet, 42 air intake temperature sensor, 44, 44A, 44B, 44C battery temperature sensor, 50 control device, 52 sensor Output value acquisition processing unit, 54 fan drive processing unit, 56 intake air temperature sensor abnormality processing unit, 60, 62, 64, 70, 72, 74 characteristic line, 66 expected characteristic line.

Claims (1)

A cooling control method for a battery having an air inlet and an air outlet for cooling the battery,
Obtaining an output value of an intake air temperature sensor provided at the intake port;
When the time change of the output value of the intake air temperature sensor is a predetermined value or more, the intake air temperature sensor is normal,
When the time change of the output value of the intake air temperature sensor is less than the predetermined value, the fan that takes in the outside air from the intake port, supplies it to the battery, and discharges it from the exhaust port is driven.
After the fan is driven, if the time change of the output value of the intake air temperature sensor is equal to or greater than the predetermined value, the intake temperature sensor is normal, and the time change of the output value of the intake air temperature sensor is the predetermined value. The battery cooling control method according to claim 1, wherein the intake air temperature sensor is abnormal when the temperature remains below the value.

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