JP6488974B2 - Battery device - Google Patents

Description

  The present invention relates to a battery device mounted on a vehicle.

  In recent years, electric vehicles such as electric vehicles using a motor as a driving source and hybrid vehicles using a motor and an engine as driving sources are often used. These electric vehicles are equipped with a chargeable / dischargeable battery that supplies electric power to the motor and charges the generated electric power when the motor is operated as a generator, and a cooling device that cools the battery. The cooling device drives a cooling fan to suck in cooling air, and flows the sucked cooling air through a cooling flow path around the battery to cool the battery.

  The cooling device control method is to detect the battery temperature, the intake air temperature, and the exhaust air temperature after cooling the battery, determine the heat generation state and cooling state of the battery, and adjust the operation of the cooling fan. A method for controlling the temperature of the battery to a temperature suitable for operation is used (see, for example, Patent Document 1).

JP 2010-57292 A

  In the control method of the prior art as described in Patent Document 1, the cooling state is adjusted by using the intake air temperature to adjust the cooling fan, so the air temperature sensor that detects the intake air temperature has failed. In some cases, the cooling fan may not be accurately adjusted. In order to detect the abnormality of the air temperature sensor, there is a method of arranging two air temperature sensors and determining that the air temperature sensor is abnormal when the difference between the detection values of the two air temperature sensors becomes large. It is done. However, this method has a problem that the number of air temperature sensors increases and the cooling device becomes complicated.

  Accordingly, an object of the present invention is to detect an abnormality of an air temperature sensor by a simple method in a battery device.

  The battery device of the present invention includes a battery for driving a vehicle, a cooling fan that supplies cooling air to the battery, an air temperature sensor that detects a temperature of the cooling air that the cooling fan supplies to the battery, A battery device comprising: a controller to which the temperature of the battery, the input / output current value of the battery, the rotation speed of the cooling fan, and the detection value of the air temperature sensor are input, The temperature difference between the first battery temperature at the first time and the second battery temperature at the second time after a lapse of a predetermined period from the first time, the amount of heat generated by the battery within the predetermined period, and the cooling fan Based on the volume of the cooling air supplied to the battery within a predetermined period and the average battery temperature within the predetermined period, the cooling fan supplies the battery to the battery. An estimated average cooling air temperature within the predetermined period is calculated, and the estimated average cooling air temperature is compared with an actual average cooling air temperature within the predetermined period based on a detection value of the air temperature sensor. It is characterized by determining abnormality.

  The present invention can detect abnormality of an air temperature sensor in a battery device by a simple method.

It is a systematic diagram which shows the structure of the battery apparatus in embodiment of this invention. It is a flowchart which shows operation | movement of the battery apparatus of this invention. It is a map which shows the relationship between the rotation speed of a cooling fan, and an air volume.

  Hereinafter, a battery device 100 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the battery device 100 includes a vehicle driving battery 10, a cooling fan 11 that supplies cooling air to the battery 10, and a temperature Ta of cooling air that the cooling fan 11 supplies to the battery 10. An air temperature sensor 21 to be detected, and a controller 30 that controls the temperature Tb of the battery 10 by adjusting the rotational speed S of the motor 12 that drives the cooling fan 11 are provided.

  The battery 10 is connected to an inverter 18 via a positive electrode line 16 and a negative electrode line 17. The inverter 18 converts the DC power of the battery 10 into AC power and drives the motor generator 19 for driving the vehicle. The AC power generated by the motor generator 19 is converted into DC power by the inverter 18 and charged to the battery 10. The positive line 16 is provided with a current sensor 24 that detects an input / output current Ib of the battery 10. A voltage sensor 23 that detects the voltage Vb of the battery 10 is provided between the positive electrode line 16 and the negative electrode line 17. In addition, a battery temperature sensor 22 that detects a temperature Tb of the battery 10 is attached to the battery 10.

  The battery 10 includes a cooling passage (not shown) inside, and the discharge port of the cooling fan 11 and the cooling air inlet of the battery 10 are connected by an intake duct 14. Further, an exhaust duct 15 for discharging the air after cooling the battery 10 is attached to the outlet of the cooling flow path of the battery 10. Therefore, as shown by the arrows in FIG. 1, the cooling air sucked from the intake port 13 of the cooling fan 11 flows into the cooling flow path inside the battery 10 through the intake duct 14 and cools the battery 10. The exhaust duct 15 is discharged. An air temperature sensor 21 that detects the temperature Ta of the cooling air supplied from the cooling fan 11 to the battery 10 is attached inside the intake duct 14. The cooling fan 11 is driven by a motor 12, and a rotation speed sensor 25 that detects the rotation speed S of the cooling fan 11 is attached to the motor 12 or the cooling fan 11.

  The controller 30 is a computer that includes a CPU 31 that performs arithmetic processing therein and a memory 32 that stores control programs, control data, and the like, and includes an air temperature sensor 21, a battery temperature sensor 22, a voltage sensor 23, and a current sensor. 24 and each detection value of the rotation speed sensor 25 are input.

  Next, the operation of the battery device 100 of this embodiment will be described with reference to FIG. The controller 30 performs the processing from S101 to S112 in FIG. 2 every predetermined period ΔT (for example, about 10 seconds), and determines whether the air temperature sensor 21 is abnormal every predetermined period ΔT.

  First, as shown in step S101 of FIG. 2, the controller 30 detects the temperature Tb of the battery 10 at the initial stage of the predetermined period ΔT by the battery temperature sensor 22, and stores it in the memory 32 as the first battery temperature Tb1 (K). Further, the temperature Ta of the cooling air supplied from the cooling fan 11 to the battery 10 at the initial stage of the predetermined period ΔT is detected by the air temperature sensor 21 and stored in the memory 32 as the first cooling air temperature Ta1 (K).

  Next, as shown in steps S102 to S104 in FIG. 2, the controller 30 performs a heat generation amount integration process of the battery 10 shown in step S102 in FIG. 2 and a step S103 in FIG. The cooling air volume integration process that the cooling fan 11 supplies to the battery 10 is repeated.

The battery heat generation amount integration process shown in step S102 of FIG. 2 detects the input / output current Ib of the battery 10 by the current sensor 24 every predetermined period Δt (for example, 100 msec, etc.), and based on the following formula (1): The calorific value ΔQH (J) of the battery 10 during a predetermined period Δt is calculated.
ΔQH = Ib ² × R × Δt (1)
Here, R is the internal resistance of the battery 10. Since the internal resistance R of the battery 10 varies depending on the temperature Tb of the battery 10, a map or a relational expression indicating the relationship of the internal resistance R to the temperature Tb of the battery 10 is stored in the memory 32 and detected by the battery temperature sensor 22. The calculated temperature Tb and this map or relational expression may be used. Moreover, it is good also as a predetermined setting value.
Next, during the predetermined period ΔT, the above-described ΔQH is integrated as in the following equation (2) to obtain the heat generation amount QH (J) of the battery 10 during the predetermined period ΔT.
QH = Σ (ΔQH) (2)

The cooling air volume integration process shown in step S103 of FIG. 2 sent to the battery 10 by the cooling fan 11 is similar to that in step S102 described above, and the cooling fan 11 is supplied every predetermined period Δt (for example, 100 msec). The rotational speed S is detected, the air volume QV (m ³ / h) of the cooling fan 11 with respect to the rotational speed S of the cooling fan 11 as shown in FIG. 3 stored in the memory 32 is calculated, and the period is calculated by the following equation (3). The volume ΔV (m ³ ) of the cooling air supplied from the cooling fan 11 to the battery 10 during Δt is calculated.
ΔV = QV × Δt (3)
Next, during the predetermined period ΔT, the volume ΔV of the cooling air V (m ³ ) supplied by the cooling fan 11 to the battery 10 during the predetermined period ΔT by accumulating the above ΔV as in the following equation (4). Ask for.
V = Σ (ΔV) (4)

  The controller 30 performs the processing of steps S102 and S103 shown in FIG. 2 for a predetermined period ΔT. When the controller 30 determines that the predetermined period ΔT has elapsed in step S104 of FIG. 2, the controller 30 proceeds to step S105 of FIG. As shown in step S105, the battery temperature sensor 22 detects the temperature Tb of the battery 10 at the end of the predetermined period ΔT, and stores it in the memory 32 as the second battery temperature Tb2 (K). Further, the temperature Ta of the cooling air supplied from the cooling fan 11 to the battery 10 at the end of the predetermined period ΔT is detected by the air temperature sensor 21 and stored in the memory 32 as the second cooling air temperature Ta2 (K).

Next, the controller 30 proceeds to step S106 shown in FIG. 2 and performs an estimation calculation of the temperature Ta of the cooling air supplied from the cooling fan 11 to the battery 10.
The heat difference ΔQB (J) between the heat generation amount QH of the battery 10 during the predetermined period ΔT and the heat amount QC taken by the cooling air from the battery 10 during the predetermined period ΔT is an initial first battery temperature Tb1 of the predetermined period ΔT. The difference between (K) and the second battery temperature Tb2 (K) at the end of the predetermined period ΔT is multiplied by the heat capacity CB (J / K) of the battery 10 stored in the memory 32, and the following formula ( It can be calculated as in 5).
ΔQB = (Tb2−Tb1) × CB (5)

Further, the amount of heat QC (J) taken by the cooling air of the cooling fan 11 from the battery 10 during the predetermined period ΔT can be calculated by the following equation (6).
QC = V × (average battery temperature Tbm−average cooling air temperature Tam)
X Volumetric specific heat (J / (m3 · K)) x Coefficient (6)
In the equation (6), the average battery temperature Tbm is an average value of the temperature Tb of the battery 10 detected by the battery temperature sensor 22 during the predetermined period ΔT. As shown in the following expression (7), the average battery temperature Tbm It may be an average temperature between the initial first battery temperature Tb1 and the second battery temperature Tb2 at the end of the predetermined period ΔT. The volume specific heat is a quantity of heat required to raise 1 ° K air ^{1m 3 (J / (m3 ·} K)). The volume specific heat and the coefficient are stored in the memory 32.
Average battery temperature Tbm = (first battery temperature Tb1 + second battery temperature Tb2) / 2
From
Tbm = (Tb1 + Tb2) / 2 (7)

The calorific value difference ΔQB (J) between the calorific value QH of the battery 10 during the predetermined period ΔT and the calorific value QC taken by the cooling air from the battery 10 is the heat generation of the battery 10 during the predetermined period ΔT calculated by the equation (2). Since the cooling air is equal to the difference between the amount of heat QC taken from the battery 10 during the predetermined period ΔT calculated by the equation (6) from the amount QH,
ΔQB = QH−QC (8)
Substituting equation (6) into equation (8),
ΔQB
= QH- [V × (Tbm-Tam) × Volume specific heat × Coefficient] (9)
Solving equation (8) for the average cooling air temperature Tam,
(Tam−Tbm) = (ΔQB−QH) / [V × volume specific heat × coefficient]
It becomes. Substituting equations (5), (1), (2), and (7) into this,
Average cooling air temperature Tam
= (ΔQB−QH) / [V × volume specific heat × coefficient] + average battery temperature Tbm
= [(Tb2−Tb1) × CB−Σ (ΔIb ² × R × Δt)] / [V × Volume specific heat × Coefficient]
+ (Tb2 + Tb1) / 2 (10)
It becomes.
In step S106 of FIG. 2, the controller 30 stores the heat generation amount QH during the predetermined period ΔT accumulated in step S102, the cooling air volume V during the predetermined period ΔT accumulated in step S103, and the memory 32. Using the heat capacity CB of the battery 10 and the volume specific heat and coefficient of the cooling air, and the first and second battery temperatures Tb1 and Tb2 detected by the battery temperature sensor 22, from the equation (10) to the predetermined period ΔT The average temperature of the cooling air supplied from the cooling fan 11 to the battery 10 (average cooling air temperature Tam) is calculated and stored in the memory 32 as the estimated average cooling air temperature Tam1.

When the controller 30 stores the estimated average cooling air temperature Tam1 in the memory 32 in step S106 of FIG. 2, the controller 30 proceeds to step S107 of FIG. 2 and stores the first cooling air temperature Ta1 and the second cooling air temperature Ta2 stored in the memory 32. Is calculated, and the actual average cooling air temperature Tam2 based on the air temperature sensor 21 during the predetermined period ΔT is calculated and stored in the memory 32.
Actual average cooling air temperature Tam2
= (First cooling air temperature Ta1 + second cooling air temperature Ta2) / 2
(12)

  Next, the controller 30 proceeds to step S108 in FIG. 2, and calculates a temperature difference ΔTa between the estimated average cooling air temperature Tam1 and the actual average cooling air temperature Tam2. Then, the process proceeds to step S109 in FIG. 2 to determine whether or not the temperature difference ΔTa exceeds a predetermined threshold value. If the temperature difference ΔTa exceeds the predetermined threshold value, the process proceeds to step S110 in FIG. 2, and it is determined that the air temperature sensor 21 is abnormal. For example, a warning is displayed on a diagnostic display, as shown in FIG. Proceed to step S112. On the other hand, if the temperature difference ΔTa does not exceed the predetermined threshold value, the process proceeds to step S111 in FIG. 2, the air temperature sensor 21 is determined to be normal, and the process proceeds to step S112 shown in FIG.

  As shown in step S112 in FIG. 2, the controller 30 clears each data stored in the memory 32 in steps S101 to S103 and S105 to S107, returns to step S101, and returns to the air temperature sensor 21 for the next predetermined period ΔT. Judgment is made.

  As described above, the battery device 100 of the present embodiment supplies the battery 10 from the cooling fan 11 based on the detection value detected by the sensor used for normal operation without providing two air temperature sensors 21. The air temperature sensor 21 can be detected by a simple method of estimating the temperature Ta of the cooling air.

  DESCRIPTION OF SYMBOLS 10 Battery, 11 Cooling fan, 12 Motor, 13 Inlet, 14 Intake duct, 15 Exhaust duct, 16 Positive line, 17 Negative line, 18 Inverter, 19 Motor generator, 21 Air temperature sensor, 22 Battery temperature sensor, 23 Voltage sensor , 24 current sensor, 25 rotation speed sensor, 30 controller, 31 CPU, 32 memory, 100 battery device.

Claims (1)

A battery for driving the vehicle;
A cooling fan for supplying cooling air to the battery;
An air temperature sensor that detects a temperature of the cooling air that the cooling fan supplies to the battery;
A battery device comprising: a controller to which the temperature of the battery, the input / output current value of the battery, the number of rotations of the cooling fan, and the detection value of the air temperature sensor are input,
The controller is
The temperature difference between the first battery temperature at the first time and the second battery temperature at the second time after a lapse of a predetermined period from the first time, the amount of heat generated by the battery within the predetermined period, and the cooling fan Based on the volume of the cooling air supplied to the battery within a predetermined period and the average battery temperature within the predetermined period, the estimated average cooling within the predetermined period supplied from the cooling fan to the battery Calculate the air temperature,
Comparing the estimated average cooling air temperature with an actual average cooling air temperature within the predetermined period based on a detection value of the air temperature sensor to determine an abnormality of the air temperature sensor;
A battery device characterized by the above.

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