JP5119575B2 - Battery module and temperature control method thereof - Google Patents

Description

  The present invention relates to a battery module, and more particularly to a battery module suitable for being cooled by circulation of a refrigerant and a temperature control method thereof.

  Power converters such as an assembled battery in which a plurality of batteries are connected as a power source for an electric vehicle or a hybrid vehicle, an inverter that converts DC power of the assembled battery into AC power, and a converter that boosts the output voltage of the assembled battery Is known.

  In such a battery module, the assembled battery generates heat along with charge / discharge, and generates heat due to the operation of the power converter. For this reason, the space in the housing is divided into rooms in which the assembled battery and the power conversion device are respectively stored, and cooling fans are provided in each room to distribute cooling air (for example, see Patent Document 1). The circulated cooling air is discharged out of the casing through an outlet provided in each room of the casing.

When such a battery module is mounted on a vehicle, usually, each discharge port and a trunk room's drafter and the like are connected to each other through a duct, and the cooling air discharged from the inside of the casing is discharged outside the vehicle compartment.
JP 2004-22317 A (FIG. 1)

  However, as described above, in a configuration in which the outlets provided in each room of the casing are connected to a drafter or the like, a plurality of ducts arranged in the middle are required, and the duct layout becomes difficult. . In addition, an increase in the number of parts reduces the space in the vehicle interior.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery module and a temperature control method thereof that can appropriately cool the battery module without requiring a plurality of ducts.

An assembled battery that generates electric power, a housing that houses the assembled battery, and the assembled battery are housed in the housing together with the assembled battery, and are arranged in series with the assembled battery along a direction in which refrigerant flows in the housing. , have a, a power conversion apparatus for converting power of the battery pack, based on the temperature of the battery pack, the direction of flow of the refrigerant are possible changes, the battery pack first temperature below the temperature of a given When the flow of the refrigerant is started from the power conversion device to the assembled battery, and the temperature of the assembled battery becomes equal to or higher than a third temperature higher than the first temperature, A battery module that is a converter that starts circulation of the refrigerant in a direction of a power converter, and the power converter boosts an output voltage of the assembled battery to a predetermined voltage and outputs the voltage .

Supplying a refrigerant so that the battery pack and the power conversion device sequentially pass through the battery pack and the power conversion device for the battery module in which the battery pack and the power conversion device are housed in series in the housing , and detecting the temperature of the battery pack And when the detected temperature of the assembled battery is equal to or lower than a predetermined first temperature, starting the flow of the refrigerant from the power converter toward the assembled battery, and the temperature of the assembled battery is Starting the circulation of the refrigerant from the assembled battery in the direction of the power converter when the temperature is equal to or higher than a third temperature higher than the first temperature, and the power converter includes an output of the assembled battery A temperature control method for a battery module, which is a converter that boosts and outputs a voltage to a predetermined voltage .

  According to the battery module of the present invention, since the assembled battery and the power conversion device are arranged side by side in the refrigerant flow direction, a single refrigerant flow path is sufficient, and the discharge port for discharging the refrigerant from the housing Will also be one. As a result, it is sufficient to provide one duct for guiding the refrigerant to the outside of the passenger compartment, and the layout can be easily performed.

  According to the temperature control method for a battery module of the present invention, since the refrigerant is supplied so as to sequentially pass through the assembled battery and the power conversion device, only one refrigerant circulation path is required and the refrigerant is discharged from the housing. There will also be one outlet. As a result, it is sufficient to provide one duct for guiding the refrigerant to the outside of the passenger compartment, and the layout can be easily performed.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a battery module according to the present embodiment.

  The battery module is mounted on a vehicle as a power source for an electric vehicle or a hybrid vehicle.

  In the present embodiment, the battery module 10 includes a battery 11 (assembled battery) 11, a temperature sensor (temperature detection means) 12, a DC / DC converter (power converter) 13, a housing 14, and a cooling fan 15. including.

  The battery 11 is formed by connecting a plurality of single cells that are stacked and arranged at approximately equal intervals in series or in parallel. As the single battery, for example, a flat lithium ion secondary battery is used. The internal resistance of the battery 11 changes according to the temperature and the deterioration state, and the output voltage changes accordingly. In this embodiment, it is assumed that the output voltage changes from about 200V to 400V.

  The temperature sensor 12 is attached to the battery 11. The temperature sensor 12 detects the temperature of the battery 11 that is heated along with charging and discharging, and transmits a detection result to the fan control unit 32 described later.

  DC / DC converter 13 (hereinafter simply referred to as converter 13) is arranged along with battery 11. Converter 13 is a booster circuit, boosts the output voltage from battery 11 to a predetermined voltage, and outputs the boosted voltage to external inverter 30. For example, the converter 13 boosts the output voltage of the battery 11 to 240V. When the output voltage of battery 11 is 240 V or higher, converter 13 stops the boosting operation and outputs the input voltage as it is.

  The housing 14 houses the battery 11 and the converter 13 in one space. Two openings 16 and 17 are provided on the side surface of the housing 14. One first opening 16 is connected to the vehicle interior. The other second opening 17 is connected to the outside of the passenger compartment, such as a trunk room. The first opening 16 and the second opening 17 serve as an inlet or an outlet for flowing in or out of the housing 14 using indoor air or outside air as a refrigerant. The first opening 16 and the second opening 17 are provided at positions where the battery 11 and the converter 13 are sandwiched therebetween. At this time, the battery 11 and the converter 13 are arranged along the flow direction of the refrigerant flowing between the first opening 16 and the second opening 17. That is, the battery 11 is arranged downstream or upstream of the converter 13 in the refrigerant flow direction.

  The cooling fan 15 is attached to the first opening 16 or the second opening 17 of the housing 14. In the present embodiment, the cooling fan 15 is attached to the second opening 17. The cooling fan 15 can change the rotation direction to forward rotation or reverse rotation. For example, when the cooling fan 15 rotates forward, the refrigerant flows from the first opening 16 toward the second opening 17. Conversely, when the cooling fan 15 rotates in the reverse direction, the refrigerant flows from the second opening 17 toward the first opening 16. The rotation direction of the cooling fan 15 is controlled by a fan control unit 32 described later.

  The battery module 10 including the above configuration is connected to the motor 31 via the inverter 30 and also connected to the fan control unit 32.

  The inverter 30 is a kind of power converter, and converts the DC power of the battery module 10 into AC power. The motor 31 is driven by the converted DC power. The motor 31 is connected to a tire (drive wheel) via a drive shaft, and generates a drive force for rotating the tire.

  The battery module 10 is connected to the fan control unit 32. The fan control unit 32 may be realized as a function of an electronic control unit (ECU) for controlling the vehicle. However, in the present embodiment, the fan control unit 32 is shown as a single configuration for the sake of clarity.

  The fan control unit 32 is connected to the temperature sensor 12 and the cooling fan 15, and controls the cooling fan 15 based on the temperature detected by the temperature sensor 12. The fan control unit 32 is connected to a timer 33 for measuring time. According to the measurement by the timer 33, the time for controlling the cooling fan 15 is adjusted. The timer 33 may also be realized as a function of the electronic control device.

  In the battery module 10 as described above, the battery 11 is heated by charging and discharging. Since the internal resistance of the battery 11 varies depending on the temperature, it is important to control the temperature of the battery 11 by the circulation of the refrigerant. A relationship between the temperature of the battery 11 and the internal resistance will be described.

  FIG. 2 is a conceptual diagram showing the relationship between the temperature of the battery and the internal resistance when new.

  As shown in FIG. 2, when the battery 11 becomes 0 ° C. or lower, the internal resistance increases rapidly. If the battery 11 is used with a high internal resistance, the load on the battery 11 is large and the life of the battery 11 may be reduced. Further, if the boosting operation is continued by the converter 13 at a low temperature such as 0 ° C. or lower, the power consumption efficiency is lowered, so that the temperature of the battery 11 does not increase easily. Therefore, it can be seen that at low temperatures, it is preferable to raise the temperature of the battery 11 as quickly as possible to lower the internal resistance of the battery 11.

  On the other hand, if the temperature of the battery 11 becomes too high, the electrolyte inside the battery 11 may vaporize and the life of the battery 11 may be reduced. Therefore, when the temperature of the battery 11 becomes a predetermined temperature, for example, 60 ° C. or higher, it is necessary to limit the output of the motor 31.

  In view of the above, it is preferable that the temperature of the battery 11 is maintained in an appropriate range of temperature, for example, in a range of 25 ° C to 35 ° C. Therefore, in the present embodiment, the temperature of the battery 11 is controlled by the above configuration. Next, a procedure for controlling the temperature of the battery module 10 will be described.

  FIG. 3 is a flowchart showing a procedure for controlling the temperature of the battery module. This control is executed by the fan control unit 32. In FIG. 3, Tb indicates the temperature of the battery 11 detected by the temperature sensor 12, and t indicates the count value by the timer 33.

  The fan control unit 32 determines whether or not the ignition is turned on, that is, whether or not the vehicle is started (step S1).

  If the ignition is not turned on (step S1: NO), the process waits until the ignition is turned on. When the ignition is turned on (step S1: YES), it is determined whether or not the temperature Tb detected by the temperature sensor 12 is −10 ° C. or less (step S2).

  When the temperature Tb is equal to or lower than −10 ° C. (first temperature) (step S2: YES), the fan control unit 32 rotates the cooling fan 15 in the reverse direction so that the refrigerant flows from the converter 13 toward the battery 11. Start (step S3). In FIG. 1, the refrigerant flows from the second opening 17 toward the first opening 16.

  At the same time, measurement by the timer 33 is started (step S4).

  Then, it is determined by the timer 33 whether or not the measurement time t has become 30 seconds or more, that is, whether or not 30 seconds have elapsed (step S5). If 30 seconds have not elapsed (step S5: NO), the cooling fan 15 continues to rotate until 30 seconds have elapsed.

  When 30 seconds have elapsed (step S5: YES), the timer 33 is stopped and the counter is reset (step S6).

  Then, it is determined whether or not the ignition is turned off (step S7). If the ignition is not turned off (step S7: NO), the process returns to step S1.

  On the other hand, when the ignition is turned off (step S7: YES), the cooling fan 15 is stopped (step S8), and the temperature control of the battery module 10 ends.

  Returning to the process of step S2, if the temperature Tb is not −10 ° C. or lower (step S2: NO), it is further determined whether or not the temperature Tb is 0 ° C. (second temperature) or lower (step S9).

  When the temperature Tb is 0 ° C. or lower (step S9: YES), the process proceeds to step S4 without changing the state of the cooling fan 15. That is, when the cooling fan 15 has already been rotated, the rotation is maintained in the same rotational direction for at least 30 seconds, and when the cooling fan 15 is stopped, the stopped state is continued for at least 30 seconds (steps S4 to S6). When the ignition is turned off (step S7: YES), the cooling fan 15 is stopped regardless of whether it is rotating (step 8), and the temperature control of the battery module 10 is finished.

  In step S9, when the temperature Tb is not 0 ° C. or lower (step S9: NO), it is further determined whether or not the temperature Tb is 35 ° C. (third temperature) or lower (step S10).

  If the temperature Tb is 35 ° C. or lower (step S10: YES), the cooling fan 15 is stopped regardless of whether it is rotating (step S11), and the process proceeds to step S4. The processing after step S4 is as described above.

  In step S10, when the temperature Tb is not 35 ° C. or lower (step S10: NO), the fan control unit 32 starts the cooling fan 15 in the reverse rotation so that the refrigerant flows from the battery 11 toward the converter 13 ( Step S12). In FIG. 1, the refrigerant flows from the first opening 16 toward the second opening 17. Then, the rotation of the cooling fan 15 is maintained for at least 30 seconds (steps S4 to S6), and when the ignition is turned off (step S7: YES), the cooling fan 15 is stopped (step 8). Temperature control ends.

  As described above, in the present embodiment, the battery 11 and the converter 13 are arranged in series on the refrigerant flow path. Therefore, only one refrigerant distribution path is required, and only one duct for connecting the second opening 17 to the outside of the passenger compartment is sufficient, thereby facilitating layout. Moreover, since the casing 14 is not divided into a plurality of rooms and a refrigerant passage is not formed for each room, the number of parts does not increase and the space in the vehicle interior does not decrease.

  Further, if the temperature Tb of the battery 11 is −10 ° C. or lower, the refrigerant flows from the converter 13 to the battery 11 due to the reverse rotation of the cooling fan 15. That is, the battery 11 is disposed on the downstream side of the converter 13. Therefore, the refrigerant heated when passing through the converter 13 is heated when passing through the battery 11. As a result, since the temperature rise of the battery 11 is promoted, the low temperature battery 11 can be quickly warmed to 0 ° C. or more.

  On the other hand, when the temperature Tb of the battery 11 becomes higher than 35 ° C., the refrigerant flows from the battery 11 to the converter 13 due to the forward rotation of the cooling fan 15. That is, the converter 13 is arranged on the downstream side of the battery 11. Therefore, when the cold refrigerant passes through the battery 11, the battery 11 is cooled. As a result, the hot battery 11 can be quickly cooled to the optimum temperature range.

  When the temperature Tb of the battery 11 is between 0 ° C. and 35 ° C., the cooling fan 15 is stopped. When the temperature Tb of the battery 11 is in the range of 0 ° C. to 35 ° C., as shown in FIG. 2, the internal resistance of the battery 11 is considerably small and the load applied to the battery 11 is also small. Leave to fever.

  Furthermore, since the cooling fan 15 can be switched between forward rotation and reverse rotation, the flow direction of the refrigerant can be easily changed.

  In the above embodiment, the battery 11, the converter 13, the temperature sensor 12, and the cooling fan 15 are housed in the housing 14 as the battery module 10. However, it is not limited to this. Depending on the layout, any configuration shown in FIG. 1 can be stored in the housing 14 as the battery module 10. On the contrary, the structure shown as the battery module 10 in the said embodiment can also be arrange | positioned out of the housing | casing 14 apart from a battery and a module. For example, the inverter 30 can be aligned with the converter 13 and housed in the housing 14 to be a part of the battery module 10.

  In the above embodiment, the state of the cooling fan controlled based on the detected temperature Tb is maintained for at least 30 seconds. However, it is not limited to this. The time for maintaining the state of the cooling fan can be adjusted as appropriate.

  In the above embodiment, only one cooling fan is provided. However, it is not limited to this. A cooling fan may be selected in the vicinity of the first opening 16 and the second opening 17 and driven according to the flow direction of the refrigerant. In this case, it is not necessary to control the cooling fan in the forward direction or the reverse direction.

It is a schematic block diagram of the battery module which concerns on this embodiment. It is a conceptual diagram which shows the relationship between the temperature of the battery at the time of a new article, and internal resistance. It is a flowchart which shows the procedure which controls the temperature of a battery module.

Explanation of symbols

10 ... Battery module,
11 ... Battery,
12 ... temperature sensor,
13 ... Converter,
14 ... Case,
15 ... Cooling fan,
16 ... 1st opening,
17 ... second opening,
30 ... Inverter,
31 ... motor,
32. Fan control unit,
33: Timer.

Claims (6)

An assembled battery for generating electric power;
A housing for storing the assembled battery;
A power conversion device that is housed in the housing together with the assembled battery, arranged in series with the assembled battery along a direction in which a refrigerant flows in the housing, and converts the power of the assembled battery;
Have
When the flow direction of the refrigerant can be changed based on the temperature of the assembled battery and the temperature of the assembled battery is equal to or lower than a predetermined first temperature, the refrigerant flows from the power conversion device toward the assembled battery. Distribution started,
When the temperature of the assembled battery is equal to or higher than a third temperature higher than the first temperature, the refrigerant starts to flow from the assembled battery toward the power converter,
The power conversion device is a battery module that is a converter that boosts and outputs an output voltage of the assembled battery to a predetermined voltage. The set temperature is higher than the first temperature of the battery, when it becomes a third lower than the temperature the second temperature or more, the battery module according to claim 1 in which circulation of the refrigerant is stopped. Temperature detecting means for detecting the temperature of the assembled battery;
Based on the temperature of the assembled battery detected by the temperature detection means, a change in rotation direction or a stop of rotation is controlled, and a cooling fan that changes or stops the circulation of the refrigerant,
The battery module according to claim 1 or 2 further comprising a. 4. The battery module according to claim 3 , further comprising a cooling fan control device configured to control a rotation direction of the cooling fan or stop of rotation based on the temperature of the assembled battery detected by the temperature detection unit. Supplying a refrigerant so that the assembled battery and the power converter are sequentially passed through the battery module in which the assembled battery and the power converter are housed in series in the housing;
Detecting the temperature of the assembled battery;
When the detected temperature of the assembled battery is equal to or lower than a predetermined first temperature, starting the flow of the refrigerant from the power conversion device in the direction of the assembled battery;
When the temperature of the assembled battery is equal to or higher than a third temperature higher than the first temperature, starting the flow of the refrigerant from the assembled battery toward the power converter;
Including
The battery module temperature control method, wherein the power converter is a converter that boosts and outputs an output voltage of the assembled battery to a predetermined voltage. The temperature control method for a battery module according to claim 5 , wherein when the temperature of the assembled battery is higher than the first temperature and equal to or higher than a second temperature lower than the third temperature, the refrigerant flow is stopped.

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