JP2013152839A - Battery temperature control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery temperature control device, performing temperature control of a battery installed on a vehicle or the like, capable of achieving optimum temperature control by exactly directing air flow toward a portion at which a temperature in a battery pack is high or low.SOLUTION: Two sensors 102 for detecting temperatures are disposed in proximity to two upper and lower faces with which air flows on each of a plurality of fins 101 are brought into contact. Each of the fins 101 and the two sensors 102 in contact with the fins are structured to rotate integrally. A control section 103 rotates the direction of each of the fins so that temperatures detected by the two sensors 102 installed on each of the fins 101 are equal to each other and so that the air flowing direction is toward a high temperature area (or a low temperature area).

Description

  The present invention relates to a battery temperature control device that adjusts the temperature of a battery mounted on a vehicle or the like.

Batteries and battery packs vary in output power characteristics depending on the environment, and are particularly sensitive to temperature.
Recently, so-called hybrid cars, plug-in hybrid cars, hybrid vehicles, hybrid electric vehicles, and the like, which are equipped with a motor (electric motor) as a power source in addition to an engine (hereinafter referred to as “vehicles”). ) Has been put to practical use. Furthermore, an electric vehicle that does not include an engine and drives the vehicle only by a motor is being put into practical use.

  As a power source for driving these motors, a lithium ion battery having a small size and a large capacity has been frequently used. In such applications, a plurality of batteries and battery packs are often connected to each other and supplied as power. In this case, the characteristics of the lithium ion battery or the like greatly change depending on the temperature, and the life of the battery greatly changes depending on the temperature of the environment in which the battery is used.

  Due to the above characteristics, the battery pack is required to be operated so as to have a predetermined temperature as much as possible, and to be controlled to suppress deterioration. Therefore, in a battery mounted on a vehicle or the like, it is important how to realize intelligent temperature adjustment control (hereinafter referred to as “temperature control”).

  As a conventional technique related to battery temperature control, a plurality of wind direction change devices are provided as air direction control means in the intake side flow path of the cooling air flow path defined between the battery module and the lower case, and the battery module A technology is known in which the flow direction of cooling air supplied to a battery module is controlled based on temperature information of the battery module input to a control unit from a temperature sensor provided on the upper surface of the battery (for example, Patent Documents) 1).

  As another conventional technique, each of the first cooling air inlet 32 and the second cooling air inlet 32 formed in each of the pair of side panels facing each other, and each of the first cooling air inlet and the second cooling air inlet. The first rectifying fins and the second rectifying fins, each of which is independently controlled in movement, and a cooling air discharge port formed so as to be positioned at a substantially middle portion between the side surfaces are provided. An assembled battery device having a casing that is provided is known. In this prior art, when the ECU determines that the temperature detected by the temperature sensor installed on the battery surface is higher than the predetermined temperature (first threshold), the ECU turns the cooling air in a diagonally upward direction. The angle of the current plate is adjusted so as to flow into the housing (for example, the technique described in Patent Document 2).

  However, in a battery having a complicated configuration such as an assembled battery, variation in internal resistance occurs for each battery cell due to manufacturing variation or aging of the battery cell constituting the assembled battery, and the temperature distribution in the assembled battery is not constant. It can change without any change. Therefore, as in the prior art, if a temperature sensor is simply arranged on the top or surface of the battery module, the air flow direction is changed in the assembled battery by the wind direction changing device or the rectifying fin based on the temperature information detected by the temperature sensor. However, it is difficult to correctly direct the temperature to a high or low temperature.

JP 2006-185788 A JP 2010-225472 A

  An object of the present invention is to realize an optimum temperature control by correctly directing the air flow direction to a portion where the temperature in the assembled battery is high or low.

  The present invention is an apparatus for adjusting the temperature of a battery by blowing air adjusted in temperature by a heat source using a fan, and is installed on a flow path of air blown from the fan to the battery. A fin that can be changed, a sensor that is installed close to the fin and detects a portion where the temperature of the battery is high, and a fin that causes the air flow toward the portion where the temperature of the battery is high based on the temperature detected by the sensor The control part which changes the flow direction of air is provided.

  According to the present invention, the air flow direction can be correctly directed to a portion where the temperature in the assembled battery is high or low based on the temperature detected by the sensor installed in the vicinity of the fin, and the optimum temperature control is achieved. Realized.

It is an apparatus block diagram of 1st Embodiment. It is a block diagram of the actuator mechanism which rotates each fin. FIG. 3 is an operation concept diagram of the first embodiment. It is explanatory drawing (the 1) of the battery internal temperature detection operation | movement in 1st Embodiment. It is explanatory drawing (the 2) of battery temperature detection operation | movement in 1st Embodiment. It is a flowchart which shows the control operation of 1st Embodiment. It is a block diagram of 2nd Embodiment. It is explanatory drawing of the battery internal temperature detection operation | movement in 2nd Embodiment. It is a flowchart which shows the control action of 2nd Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is an apparatus configuration diagram of a first embodiment of the present invention. 1st Embodiment is implemented as a battery temperature control apparatus which performs temperature control of the battery mounted in a vehicle.

The assembled battery (hereinafter simply referred to as “battery”) 104 is, for example, a lithium ion battery that drives a vehicle or the like, and includes a plurality of battery cells.
The battery 104 is cooled or heated by the air emitted from the fan 106 being cooled or heated by the Peltier element 105 as a heat source and then blown to the battery 104 through the plurality of fins 101.

In the first embodiment, two sensors 102 for detecting temperature are installed in close proximity to the upper and lower surfaces where the air flow on each fin of the plurality of fins 101 contacts.
Each fin 101 and the two sensors 102 adjacent thereto are configured to rotate together.

  Based on the temperature detected by each of the two sensors 102 installed in each fin 101, the control unit 103 rotates the direction of each fin 101 so that the air flows toward the portion where the temperature of the battery 104 is high. Change the flow direction of

FIG. 2 is a configuration diagram of an actuator mechanism that rotates each fin 101. In FIG. 2, the fin 101, the sensor 102, and the control unit 103 are the same as those in FIG.
Each fin 101 is configured to be rotatable by a motor 202 via a gear group 203.

  Based on the temperatures detected by the two sensors # 1 and # 2 installed on the upper and lower surfaces of the fin 101, the control unit 103 controls the gear group so that the air flow is directed toward the portion where the temperature of the battery 104 is high. A rotation angle 203 is determined, and a digital value of the rotation angle information is output to the D / A converter 202. The D / A converter 202 converts the digital value into analog rotation angle information and causes the motor 202 to input the digital value. As a result, the motor 202 drives the gear group 203 by the rotation angle corresponding to the input rotation angle information, and rotates the fin 101. At this time, the rotation state in the gear group 203 is detected by the encoder 204 and fed back to the control unit 103. Thereby, the control unit 103 corrects the rotation angle information given to the motor 202 by feedback control, and realizes accurate rotation of the fin 101. The rotation direction of the fin 101 can change the air flow direction.

The above actuator mechanism is configured for each fin 101.
FIG. 3 is an operation conceptual diagram of the first embodiment. In the configuration of the first embodiment shown in FIG. 1 and FIG. 2, the plurality of fins 101 are usually configured such that the air blown from the fan 106 via the Peltier element 105 is as shown in FIG. The battery 104 is arranged so as to hit the battery 104 in the horizontal direction in FIG. Thereafter, it is assumed that the temperature of the region indicated by 301 in the battery 104 in FIG. 3B has increased due to variations in the internal resistance of the battery cells in the battery 104. In this case, each fin 101 is rotated as shown in FIG. 3B by information from the sensor 102 installed close to each fin 101. As a result, the air blown from the fan 106 through the Peltier element 105 is controlled so as to be directed toward the region 301 where the temperature in the battery 104 is high through each rotated fin 101. As a result, the region 301 having a high temperature in the battery 104 is appropriately cooled. In the case where the temperature of the battery 104 is partially low, the air heated by the Peltier element 105 is blown in the direction of the part through the fin 101, so that an appropriate heating operation is performed. Is done.

  Here, since the battery (assembled battery) 104 constituted by a large number of battery cells has a complicated and dense configuration, it is costly to appropriately arrange sensors for detecting the temperature at each location in the battery 104. It is difficult from the aspect. For this reason, conventionally, a sensor for detecting the temperature of the assembled battery has been installed on the surface of the module of the battery cell. However, in this case, it is difficult to accurately detect a portion having a high temperature in the assembled battery, and it is difficult to appropriately control the fins.

  On the other hand, the first embodiment makes it possible to accurately detect the region 301 having a high temperature in the battery 104 not by the battery 104 but by the sensor 102 installed in the vicinity of the fin 101. .

FIG. 4 is an explanatory diagram (part 1) of the battery temperature detection operation in the first embodiment.
In the first embodiment, as shown as # 1 and # 2 sensors 102 in FIG. 4A, the sensors 102 are installed close to the upper and lower surfaces where the air flow on the fin 101 contacts. The

  Here, it is assumed that a region 401 having a high temperature exists in the battery 104 obliquely below, for example, as shown in FIG. In this case, it is considered that the detected temperature is higher in the # 2 sensor 102 that is directly heated by the region 401 where the temperature is higher than the # 1 sensor 102. Therefore, the inventor of this patent application controls the inclination of the fin 101 so that the detection temperatures of the two sensors 102 of # 1 and # 2 are equal in one fin 101, thereby controlling the direction of the fin with good control. It was found that it can be controlled. That is, as shown in FIG. 4B, the fins 101 are rotated so that the tilt axis 402 of the fins 101 coincides with the direction of the high temperature region 401, whereby the sensors 102 of # 1 and # 2 are used. The temperatures detected by are almost equal. Accordingly, the air cooled from the fan 106 in FIG. 1 through the Peltier element 105 passes through the fin 101 inclined as shown in FIG. Will be.

FIG. 5 is an explanatory diagram (part 2) of the temperature detection operation in the battery according to the first embodiment.
Now, let h1 and h2 be the distance between the heat source and the sensors 102 of # 1 and # 2, respectively. In general, the temperature distribution from the heat source in the high temperature region 401 is concentrically distributed, and the temperature decreases as the distance increases. Therefore, if there is a difference between the distance h1 from the heat source to the # 1 sensor 102 and the distance h2 from the heat source to the # 2 sensor 102, the detected temperature of each of the sensors # 1 and # 2 is different. . On the other hand, as shown in FIG. 4B, when the tilt axis 402 of the fin 101 faces the direction of the heat source, the three points at the center of the heat source and each sensor 102 are in an isosceles triangle relationship. Thus, the distance h1 and the distance h2 are substantially equal. Therefore, in this case, the detected temperatures of the sensors # 1 and # 2 are substantially equal.

  Based on the above knowledge, by controlling the rotation angle of the fin 101 so that the detected temperatures of the sensors # 1 and # 2 are equal, the tilt axis 402 of the fin 101 is directed to the heat source in the region 401 where the temperature is high. It is thought that it can be controlled in this way.

  Here, the distance between the sensors 102 of # 1 and # 2 is d, and the angle formed by the tilt axis 402 of the fin 101 with respect to the horizontal line is θ. In this case, when θ is small, the following equation is established.

h1−h2 = dsinθ≈dθ (1)
Now, the rate of change of the temperature T with respect to the distance x from the heat source in the battery 104 is (dT / dx). In this case, a value dθ (dT / dx) obtained by multiplying the difference between h1 and h2 obtained by the equation (1) by the change rate (dT / dx) is a temperature difference corresponding to the difference between h1 and h2. . Therefore, if the temperature detection accuracy of each sensor 102 is, for example, 0.1 [degree],
dθ (dT / dx)> 0.1 [degree] (2)
In this case, it can be said that there is a detectable temperature difference between the sensors 102 of # 1 and # 2.

The distance d between the sensors 102 of # 1 and # 2 and the minimum rotation angle θ may be determined so as to satisfy the relationship of the above expression (2).
FIG. 6 is a flowchart showing the control operation of the first embodiment having the configuration of FIGS. 1 and 2. This control operation is realized as an operation in which a CPU (central processing unit) (not shown) in the control unit 103 executes a control program stored in a memory (not shown). Note that the control operation of the flowchart of FIG. 6 is sequentially executed for all the fins 101 of FIG.

First, the control unit 103 in FIG. 1 acquires the temperature T1 of the sensor 102 # 1 (step S601).
Next, the control unit 103 acquires the temperature T2 of the sensor # 2 (step S602).

Then, the control unit 103 determines whether or not the absolute value | T1−T2 | of the difference between the temperatures T1 and T2 is smaller than a predetermined temperature difference threshold th (step S603).
If | T1-T2 | <th and the determination in step S603 is YES, the control unit 103 does not need to rotate the fin 101 currently being controlled. In this case, the control unit 103 returns to the process of step S601 and repeatedly executes a series of processes from step S601 to S603.

  If | T1-T2 | <th is not satisfied and the determination in step S603 is NO, the control unit 103 sets the motor 202 of the actuator mechanism in FIG. 2 to D / A (digital / analog) by K (T1-T2) degrees. ) Driven through the converter 201 (step S604). Here, K is a proportional gain having an appropriate value. As a result, the motor 202 drives the gear group 203 to rotate the fin 101.

Next, the control unit 103 measures an error between the rotation angle set in step S604 and the rotation angle detected by the encoder 204 in FIG. 2 (step S605).
The control unit 103 determines whether or not the error measured in step S605 is smaller than a predetermined threshold (step S606).

  If the error is equal to or greater than the threshold value and the determination in step S606 is NO, the control unit 103 continues to drive the motor 202 and repeats the error measurement and determination processing in steps S605 and S606.

When the error is smaller than the threshold value and the determination in step S606 is YES, the rotation control for the fin 101 is stopped, and the process returns to step S601.
Note that the control operation in the flowchart of FIG. 6 is terminated by a program interrupt triggered by, for example, turning off the ignition of the vehicle (step S608).

  With the control process of the first embodiment described above, the simple configuration of installing the two sensors 102 above and below the fin 101 makes it possible to accurately direct the fin 101 to a region where the temperature inside the battery 104 is high, As a result, it is possible to appropriately cool the region where the temperature is high. It should be noted that the same control is possible when a low temperature region occurs in the battery 104 and heating operation is required.

  In the configuration of the first embodiment shown in FIG. 1, two sensors 102 are installed on the upper and lower surfaces of each fin 101. On the other hand, two sensors 102 may be installed on a predetermined fin 101 among the plurality of fins 101. In this case, the control unit 103 controls the predetermined fins 102 and the predetermined fins 101 so that the temperatures detected by the sensors 102 corresponding to the upper and lower surfaces of the predetermined fins 101 are equal to the predetermined fins 101. The direction of the fins 102 in the vicinity of the predetermined fin 102 where the sensor 102 is not installed can be configured to rotate in common.

  FIG. 7 is an apparatus configuration diagram of the second embodiment of the present invention. Similarly to the case of the first embodiment, the second embodiment is also implemented as a battery temperature control device that controls the temperature of a battery mounted on a vehicle. In the configuration of the second embodiment shown in FIG. 7, the same reference numerals as those in the first embodiment shown in FIG. 1 have the same functions. The configuration of the second embodiment shown in FIG. 7 is different from the configuration of the first embodiment shown in FIG. 1 in that a sensor for detecting temperature is installed on the air flow path close to the fin 101, The thermographic sensor 701 detects the temperature distribution of the battery 104.

FIG. 8 is an explanatory diagram of the battery temperature detection operation in the second embodiment.
In the configuration of the second embodiment, for example, a thermographic temperature distribution image 801 as shown in FIG. 8 detected by the thermographic sensor 701 in FIG. And the direction of the fin 101 is rotated so that the air flow is directed to that portion.

The configuration of the actuator mechanism that rotates the fin 101 is the same as the configuration of FIG. 2 in the first embodiment.
FIG. 9 is a flowchart showing the control operation of the second embodiment having the configuration of FIGS. 1 and 2. This control operation is realized as an operation in which a CPU (not shown) in the control unit 103 executes a control program stored in a memory (not shown). The control operation of the flowchart of FIG. 9 is sequentially executed for all the fins 101 of FIG.

First, the control unit 103 acquires information of a thermographic image by the thermographic sensor 701 (step S901).
Next, the control unit 103 identifies the highest temperature position (P1) and the lowest temperature position (P2) on the thermographic image, and obtains the temperature (T1 for P1 and T2 for P2) at each position. (Step S902).

Next, the control unit 103 determines whether or not the temperature T1 at the hottest position P1 is higher than the high temperature threshold thmax (step S903).
If T1> thmax and the determination in step S903 is YES, the control unit 103 sets the Peltier element 105 to cooling (step S904).

  And the control part 103 rotates the fin 101 so that it may face the hottest position P1. This control process is the same as the process of steps S604 to S607 in FIG. 6 in the first embodiment.

When the rotation ends, the control unit 103 returns to the process of step S901.
If T1> thmax is not satisfied and the determination in step S903 is NO, the control unit 103 determines whether the temperature T2 at the lowest temperature position P2 is lower than the low temperature threshold thmin (step S906).

If T1 <thmin and the determination in step S906 is YES, the control unit 103 sets the Peltier element 105 to heating (step S907).
And the control part 103 rotates the fin 101 so that it may face the coldest position P2. This control process is also the same as the process of steps S604 to S607 in FIG. 6 in the first embodiment, similarly to step S905.

When the rotation ends, the control unit 103 returns to the process of step S901.
Even when T1 <thmin is not satisfied and the determination in step S906 is NO, the control unit 103 returns to the process in step S901.

Note that the control operation in the flowchart of FIG. 9 ends with a program interrupt triggered by, for example, turning off the ignition of the vehicle (step S909).
With the above-described control process of the second embodiment, the temperature of the fin 101 in the battery 104 is high as in the case of the first embodiment by a simple configuration in which the thermographic sensor 701 is installed in the vicinity of the fin 101. It is possible to accurately aim at (or low) areas, which allows the area to be properly cooled (or heated).

DESCRIPTION OF SYMBOLS 101 Fin 102 Sensor 103 Control part 104 Battery 105 Peltier element 106 Fan 201 D / A converter 202 Motor 203 Gear group 204 Encoder 301, 401 High temperature area 402 Inclination axis 701 Thermography sensor 801 Thermography image 802 The highest temperature part

Claims (6)

A device that adjusts the temperature of the battery by blowing air that has been temperature adjusted by a heat source using a fan,
A fin installed on a flow path of air blown from the fan to the battery and capable of changing a flow direction of the air;
A sensor that is installed close to the fin and detects a portion of the battery having a high temperature;
A control unit that changes the flow direction of the air with respect to the fin so that the flow of the air is directed toward a portion where the temperature of the battery is high based on a temperature detected by the sensor;
A battery temperature control device comprising: The sensors are installed close to two upper and lower surfaces where the air flow on the fin contacts,
The control unit rotates the direction of the fin so that the temperatures detected by the sensors corresponding to the upper and lower two surfaces are equal.
The battery temperature control apparatus according to claim 1, wherein The sensor is installed on a predetermined fin among the plurality of fins,
The control unit is provided with the predetermined fin and the sensor such that the temperature detected by each sensor corresponding to the upper and lower surfaces of the predetermined fin is equal to each of the predetermined fin. Rotating the direction of the fins in the vicinity of the predetermined fin in common,
The battery temperature control apparatus according to claim 2, wherein: The sensor is a thermographic sensor that is installed on the air flow path close to the fin and detects the temperature distribution of the battery,
The control unit rotates the direction of the fin based on a temperature distribution detected by the thermographic sensor.
The battery temperature control apparatus according to claim 1, wherein The control unit rotates the direction of the fins so that the flow of the air is directed to the highest temperature portion or the lowest temperature portion in the temperature distribution detected by the thermographic sensor.
The battery temperature control apparatus according to claim 4, wherein The control unit sets the heat source to cooling when the highest temperature portion in the temperature distribution detected by the thermography sensor exceeds the first temperature threshold, and the lowest temperature portion in the temperature distribution. Sets the heat source to heating when is below a second temperature threshold;
The battery temperature control apparatus according to claim 5, wherein