JP2013207927A - Charge control device for vehicle battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge control device for a vehicle battery pack, capable of satisfactorily reducing the temperature of the vehicle battery pack and expanding the lifetime of the vehicle battery pack.SOLUTION: When charging starts from an external power supply 10 to a battery pack 3, an in-charging lamp 24 is lit on, so as to supply the notification of in-charging. At the same time, a surface temperature at a plurality of positions of the battery pack 3 is detected. If a surface temperature at at least one position is a predetermined temperature or higher, a predetermined period after the start of charging is set to be a suspension period. In the suspension period, the in-charging lamp 24 continues to be lit on, so as to continue the notification of in-charging, whereas charging from the external power supply 10 to the battery pack 3 is suspended.

Description

  The present invention relates to a charge control device for an assembled battery for vehicles.

  A vehicle such as an electric vehicle (EV) or a hybrid vehicle (HV: Hybrid Vehicle) is equipped with a high voltage battery for storing electric power supplied to a traveling motor. As a high-voltage battery, an assembled battery configured by connecting a plurality of secondary batteries is widely used.

  The temperature of the assembled battery rises due to heat generated by charging and discharging. When the temperature of the assembled battery rises, the deterioration of the assembled battery (secondary battery) proceeds and the life of the assembled battery is reduced. Therefore, temperature management is important for the assembled battery.

  For example, it has been proposed to cool a battery pack by driving a battery cooling fan when the battery surface temperature exceeds a predetermined limit temperature during charging of the battery pack. However, according to this method, the individual secondary batteries constituting the assembled battery cannot be cooled uniformly, and temperature variation occurs between the secondary batteries. When the temperature varies, the secondary battery deteriorates, resulting in a decrease in the life of the assembled battery as a whole.

  In addition, when the battery pack is charged evenly, the temperature of the secondary battery having the highest temperature among the secondary batteries is detected, and the charging current is reduced in accordance with the temperature rise, thereby suppressing the temperature rise of the secondary battery. It has been proposed. However, a reduction in the charging current alone has a small effect of suppressing the temperature rise of the secondary battery, and cannot prevent a reduction in the life of the secondary battery. In addition, temperature management of the assembled battery is required even during normal charging that is not equal charging.

JP 2000-21457 A JP 2001-314046 A

  The objective of this invention is providing the charge control apparatus of the assembled battery for vehicles which can reduce the temperature of the assembled battery for vehicles favorably, and can extend the lifetime of the assembled battery for vehicles.

  In order to achieve the above object, a charging control apparatus for an assembled battery for a vehicle according to the present invention includes an assembled battery for a vehicle that accumulates electric power supplied to a vehicle driving motor, an external power supply provided outside the vehicle, and It is used for a vehicle provided with the charging circuit which connects the said assembled battery for vehicles, and the cooling means which cools the said assembled battery for vehicles. The charging control device includes battery temperature detection means for detecting surface temperatures at a plurality of positions in the vehicle assembled battery, and an in-charge notification for informing that the vehicle assembled battery is being charged from the external power source. And at the start of charging from the external power source to the assembled battery for the vehicle, the charging informing means starts notifying that charging is in progress, and the temperature detected by the battery temperature detecting means is referred to When the surface temperature at at least one position is equal to or higher than a predetermined temperature, the charging is performed while the charging notifying means continues to be informed during the predetermined suspension period after the start of charging. Pause control means for controlling a circuit to pause charging from the external power source to the assembled battery for vehicles.

  Electric power is supplied to the vehicle running motor from the assembled battery for the vehicle. The vehicle is provided with a charging circuit for charging the assembled battery for the vehicle with electric power from an external power source. Further, in consideration of temperature rise due to heat generation during charging / discharging of the assembled battery for vehicles, the vehicle is provided with cooling means for cooling the assembled battery for vehicles.

  When charging from the external power source to the vehicle battery pack is started, it is notified that charging is in progress. At the same time, surface temperatures at a plurality of positions of the assembled battery for a vehicle are detected. And if the surface temperature in at least 1 position is more than predetermined temperature, the predetermined period after charge start will be set as a rest period. In the suspension period, charging from the external power source to the assembled battery for the vehicle is suspended while the notification that charging is in progress is continued.

  Even if charging is started in a state where the assembled battery for the vehicle is at a high temperature, the temperature of the assembled battery for the vehicle at the end of charging can be lowered by stopping the charging after the start of charging. Therefore, it is possible to prevent the assembled battery for a vehicle from being in an abnormally high temperature state while the vehicle is running after the charging is completed. As a result, it is possible to prevent deterioration of the assembled battery for a vehicle due to a temperature rise. Further, it is possible to prevent the output of the traveling motor from being restricted (the discharge from the assembled battery for the vehicle is restricted) due to the abnormally high temperature state of the assembled battery for the vehicle during traveling of the vehicle.

  Furthermore, since it is not natural cooling by a cooling means such as a blower fan but natural cooling by suspension of charging, it is possible to suppress the occurrence of temperature variations among a plurality of secondary batteries constituting the assembled battery for vehicles. As a result, it is possible to suppress a variation in deterioration due to a variation in temperature between the plurality of secondary batteries, and to extend the life of the assembled battery for a vehicle.

  In addition, since the notification that charging is in progress is continued even during the suspension of charging, it is possible to prevent the user from separating the assembled battery for the vehicle and the external power source due to an erroneous determination that charging is complete.

  The temperature difference between the minimum temperature and the maximum temperature of the surface temperature of the assembled battery for a vehicle may be monitored, and the time point when the temperature difference reaches a predetermined value or more may be set as the beginning of the suspension period.

  When a temperature difference of a predetermined value or more occurs in the surface temperature of the assembled battery for the vehicle, the assembled battery for the vehicle can be cooled by stopping charging to the assembled battery for the vehicle, and the temperature difference is reduced. can do. As a result, the life of the assembled battery for vehicles can be further extended.

  During the suspension period, the cooling of the assembled battery by the cooling means may be suppressed.

  Thereby, it can suppress that the temperature difference resulting from cooling nonuniformity between several secondary batteries arises. As a result, the temperature difference between the surface temperatures of the assembled battery for vehicles can be further reduced, and the life of the assembled battery for vehicles can be further extended.

  ADVANTAGE OF THE INVENTION According to this invention, the temperature of the assembled battery for vehicles can be reduced favorably, and the lifetime of the assembled battery for vehicles can be extended.

FIG. 1 is a block diagram illustrating a configuration of a main part of a vehicle provided with a charge control device according to an embodiment of the present invention. FIG. 2A is a flowchart (part 1) illustrating a flow of charge control. FIG. 2B is a flowchart (part 2) illustrating the flow of charge control. FIG. 3 is a flowchart showing another procedure for setting the suspension period. FIG. 4 is a graph showing the change over time of the maximum temperature, the minimum temperature, and the temperature difference between the maximum temperature and the minimum temperature of the surface temperature of the assembled battery. FIG. 5A is a flowchart illustrating another example of charge control. FIG. 5B is a flowchart illustrating another example of the charge control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a configuration of a main part of a vehicle provided with a charge control device according to an embodiment of the present invention.

  The vehicle 1 is an automobile (an electric car or a hybrid car) that uses a traveling motor 2 as a drive source.

  The vehicle 1 includes an assembled battery 3 for storing electric power supplied to the traveling motor 2, and a charging circuit 4 connected to the assembled battery 3 and charging the assembled battery 3.

  The assembled battery 3 is configured by electrically connecting a plurality of (for example, 1000) secondary batteries 5 to each other and housing them in one package 6.

  A blower duct 7 is connected to one end of the package 6. A blower fan 8 is disposed in the blower duct 7. Further, an exhaust port (not shown) is formed at the other end of the package 6. When the blower fan 8 is driven, cooling air is supplied from the air duct 7 into the package 6, and the cooling air passes through the package 6 toward the exhaust port. Thereby, at the time of charging / discharging of the assembled battery 3, the assembled battery 3 can be cooled with cooling air.

  The charging circuit 4 is electrically connected to a charging port 9 provided in the vehicle 1. On the other hand, a charging cable 11 is connected to an external power source 10 installed outside the vehicle 1. A charging connector 12 that can be connected / disconnected to / from the charging port 9 is provided at the tip of the charging cable 11. By connecting the charging connector 12 to the charging port 9, the charging circuit 4 and the external power supply 10 are electrically connected.

  The charging circuit 4 includes a relay for electrically connecting / disconnecting the assembled battery 3 and the external power source 10, a protection circuit for preventing an inrush current when the relay is turned on, and the like. When the relay is turned on, the assembled battery 3 and the external power supply 10 are electrically connected, and the assembled battery 3 is charged with power from the external power supply 10. On the other hand, when the relay is turned off, the assembled battery 3 and the external power supply 10 are electrically disconnected, and charging of the assembled battery 3 by the power from the external power supply 10 is stopped.

  In addition, the vehicle 1 includes a control unit 21 having a configuration including a CPU and a memory.

  A battery temperature sensor 22 and an outside air temperature sensor 23 are connected to the control unit 21. The battery temperature sensor 22 is disposed at each of a plurality of positions (for example, 20 locations) of the assembled battery 3, and detects the surface temperature at each position. The outside air temperature sensor 23 detects the temperature outside the vehicle 1 (outside temperature). The controller 21 receives the surface temperature at each of a plurality of positions of the assembled battery 3 detected by the battery temperature sensor 22 and the outside air temperature detected by the outside air temperature sensor 23.

  Then, the control unit 21 controls the charging circuit 4 based on temperatures detected by the battery temperature sensor 22 and the outside air temperature sensor 23. The control unit 21 controls lighting of the charging lamp 24. The charging lamp 24 is provided in the vehicle 1 and / or the external power supply 10 in order to notify that the assembled battery 3 is being charged with power from the external power supply 10. Further, the control unit 21 controls driving of the blower fan 8.

  2A and 2B are flowcharts showing the flow of charge control.

  When the charging connector 12 is connected to the charging port 9, the relay of the charging circuit 4 is turned on by the control unit 21, and charging of the assembled battery 3 with electric power from the external power source 10 is started (step S1). The relay may be turned on immediately in response to the charging connector 12 being connected to the charging port 9. For example, if the charging connector 12 is connected to the charging port 9 before 11 pm, To use midnight power, the relay may be turned on at 11:00 pm.

  When charging is started, the control unit 21 executes the following control.

  First, the charging lamp 24 is turned on (step S2). While the charging lamp 24 is lit, the blower fan 8 is driven with a constant blowing capacity (air volume).

  Next, whether the surface temperature (battery temperature) of the assembled battery 3 detected by the at least one battery temperature sensor 22 is referred to the temperature detected by the battery temperature sensor 22 is equal to or higher than a predetermined temperature, for example, 50 ° C. or higher. Is determined (step S3).

  If this determination is affirmed (YES in step S3), a suspension period for suspending charging of the assembled battery 3 is set. The suspension period is set by avoiding the time period in which the outside air temperature is estimated to be the lowest among the time required from the start of charging to the completion of charging. Further, the length of the suspension period is determined based on the maximum surface temperature of the assembled battery 3 detected by the battery temperature sensor 22 and the outside air temperature detected by the outside air temperature sensor 23. For example, it is set within a range of 60 to 100 minutes so that the surface temperature approaches the target temperature (for example, 33 ° C.) as much as possible.

  Thereafter, when it becomes the timing (pause timing) at which the suspension period starts (YES in step S4), the relay of the charging circuit 4 is switched from on to off, and charging of the assembled battery 3 is stopped (step S5).

  When the end of the suspension period comes (YES in step S6), the relay of the charging circuit 4 is switched from off to on, and charging of the assembled battery 3 is resumed (step S7).

  Thereafter, when the assembled battery 3 is fully charged, it is determined that charging of the assembled battery 3 is completed (YES in step S8), the relay of the charging circuit 4 is switched from on to off, and the assembled battery 3 is charged. Stopped (finished) (step S9).

  Then, the charging lamp 24 is turned off (step S10), and the charging control shown in FIGS. 2A and 2B is ended.

  On the other hand, after the start of charging, when the surface temperature (battery temperature) of the assembled battery 3 detected by all the battery temperature sensors 22 is lower than the predetermined temperature (NO in step S3), the charging of the assembled battery 3 is suspended. It continues without being. When the assembled battery 3 is fully charged, it is determined that the charging of the assembled battery 3 is completed (YES in step S8), the relay of the charging circuit 4 is switched from on to off, and the assembled battery 3 is charged. Stopped (finished) (step S9).

  Thereafter, the charging lamp 24 is turned off (step S10), and the charging control shown in FIGS. 2A and 2B is ended.

  As described above, when charging of the assembled battery 3 from the external power source 10 is started, the charging lamp 24 is turned on to notify that charging is in progress. At the same time, surface temperatures at a plurality of positions of the assembled battery 3 are detected. And if the surface temperature in at least 1 position is more than predetermined temperature, the predetermined period after charge start will be set as a rest period. During the suspension period, charging from the external power source 10 to the assembled battery 3 is suspended while the charging lamp 24 continues to be lit and notification that charging is in progress.

  Even if charging is started in a state where the assembled battery 3 is at a high temperature, the temperature of the assembled battery 3 at the end of charging can be lowered by stopping the charging after the start of charging. Therefore, it is possible to prevent the assembled battery 3 from being in an abnormally high temperature state while the vehicle 1 is running after the end of charging. As a result, it is possible to prevent deterioration of the assembled battery 3 due to a temperature rise. Further, it is possible to prevent the output of the traveling motor 2 from being restricted (the discharge from the assembled battery 3 is restricted) due to the abnormally high temperature state of the assembled battery 3 while the vehicle 1 is traveling.

  Furthermore, since the cooling is not the cooling by the blower fan 8 but the natural cooling by the suspension of charging, it is possible to suppress the occurrence of temperature variation among the plurality of secondary batteries 5 constituting the assembled battery 3. As a result, it is possible to suppress the occurrence of variation in deterioration due to temperature variation among the plurality of secondary batteries 5, thereby extending the life of the assembled battery 3.

  In addition, since the notification that the charging is in progress is continued even during the suspension of the charging, it is possible to prevent the user from separating the assembled battery 3 and the external power source 10 due to an erroneous determination that the charging is completed.

  FIG. 3 is a flowchart showing another procedure for setting the suspension period. FIG. 4 is a graph showing the change over time of the maximum temperature, the minimum temperature, and the temperature difference between the maximum temperature and the minimum temperature of the surface temperature of the assembled battery.

  In the charging control shown in FIGS. 2A and 2B, the suspension period is set to avoid the time zone in which the outside air temperature is the lowest among the time required from the start of charging to the completion of charging. Instead, the suspension period may be set by the procedure shown in FIG.

  That is, the temperature difference between the maximum temperature and the minimum temperature of the surface temperature of the assembled battery 3 detected by the battery temperature sensor 22 is calculated with reference to the detected temperature of the battery temperature sensor 22. When the temperature difference becomes equal to or greater than the predetermined value (YES in step S11), the time is set as the start of the suspension period (step S12). In this case, at the same time as the start of the suspension period is set, at step S4 in the flowcharts shown in FIGS. 2A and 2B, the determination as to whether or not it is the timing to start the suspension period is affirmed, and the relay of the charging circuit 4 Is switched from on to off, and charging of the battery pack 3 is stopped.

  As in the case of the above-described embodiment, the group at the end of charging is based on the maximum surface temperature of the assembled battery 3 detected by the battery temperature sensor 22 and the outside air temperature detected by the outside air temperature sensor 23. The length of the suspension period is set so that the surface temperature of the battery 3 approaches the target temperature as much as possible.

  As shown in FIG. 4, after the charging of the assembled battery 3 starts, the surface temperature of the assembled battery 3 once rises and then gradually decreases as the charging proceeds. Since the degree of the temperature drop varies among the secondary batteries 5, the temperature difference between the highest temperature and the lowest temperature increases as the surface temperature of the assembled battery 3 decreases. For example, when about 60 minutes have elapsed since the start of charging, the maximum surface temperature of the assembled battery 3 is about 47 ° C., the minimum temperature is about 37 ° C., and the temperature difference between the maximum temperature and the minimum temperature is about Spread to 10 ° C. If charging is continued, it is considered that the temperature difference is substantially maintained or the temperature difference is further widened as indicated by a virtual line (two-dot chain line) in FIG. Therefore, when the temperature difference between the maximum temperature and the minimum temperature of the surface temperature of the assembled battery 3 becomes 10 ° C. or more, the relay of the charging circuit 4 is switched from on to off, and charging of the assembled battery 3 is stopped. Thereby, the degree of temperature drop of the secondary battery 5 that is easier to cool than the other secondary batteries 5 is reduced, and the temperature difference between the maximum temperature and the minimum temperature of the surface temperature of the assembled battery 3 is reduced.

  As a result, it is possible to suppress a variation in deterioration due to a temperature variation between the plurality of secondary batteries 5, and to further extend the life of the assembled battery 3.

  5A and 5B are flowcharts showing another example of charge control.

  In the charging control shown in FIGS. 2A and 2B, it is assumed that the blowing fan 8 is driven with a constant blowing capacity (air volume) while the charging lamp 24 is lit. However, the air volume by the blower fan 8 may be suppressed during the suspension of charging of the assembled battery 3.

  Specifically, when charging is started (step S21), the charging lamp 24 is turned on (step S22).

  Then, it is determined whether or not the surface temperature (battery temperature) of the assembled battery 3 detected by the at least one battery temperature sensor 22 is equal to or higher than a predetermined temperature, for example, 50 ° C. (step S23).

  If this determination is affirmed (YES in step S23), a suspension period for suspending charging of the assembled battery 3 is set as in the case of the charge control shown in FIGS. 2A and 2B.

  Thereafter, when it becomes the timing (pause timing) at which the suspension period starts (YES in step S24), the relay of the charging circuit 4 is switched from on to off, and charging of the assembled battery 3 is stopped (step S25).

  Moreover, the air volume by the ventilation fan 8 is reduced with a stop of charge (step S26).

  When the end of the suspension period comes (YES in step S27), the relay of the charging circuit 4 is switched from off to on, and charging of the assembled battery 3 is resumed (step S28).

  Moreover, with the resumption of charging, the air volume by the blower fan 8 is returned to the original air volume (step S29).

  Thereafter, when the assembled battery 3 is fully charged, it is determined that charging of the assembled battery 3 is completed (YES in step S30), the relay of the charging circuit 4 is switched from on to off, and charging of the assembled battery 3 is performed. Stopped (finished) (step S31).

  Then, the charging lamp 24 is turned off (step S32), and the charging control shown in FIGS. 5A and 5B is ended.

  On the other hand, after the start of charging, when the surface temperature (battery temperature) of the assembled battery 3 detected by all the battery temperature sensors 22 is lower than the predetermined temperature (NO in step S23), charging of the assembled battery 3 is suspended. It continues without being. When the assembled battery 3 is fully charged, it is determined that the charging of the assembled battery 3 is completed (YES in step S30), the relay of the charging circuit 4 is switched from on to off, and the assembled battery 3 is charged. Stopped (finished) (step S31).

  Thereafter, the charging lamp 24 is turned off (step S32), and the charging control shown in FIGS. 5A and 5B is ended.

  The temperature difference in the surface temperature of the assembled battery 3 is considered to be one of the causes because the cooling by the air blowing of the blower fan 8 is uneven. During suspension of charging of the assembled battery 3, the drive of the blower fan 8 is stopped, so that it is possible to suppress a temperature difference caused by uneven cooling among the plurality of secondary batteries 5. As a result, the temperature difference in the surface temperature of the assembled battery 3 can be further reduced, and the life of the assembled battery 3 can be further extended.

  While the embodiments of the present invention have been described above, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

  For example, the time when the maximum temperature of the surface temperature of the assembled battery 3 detected by the battery temperature sensor 22 becomes equal to or higher than a predetermined temperature (for example, 45 ° C.) after the charging of the assembled battery 3 is started is set as the start of the cooling period. Also good.

  In addition, the time when a predetermined time has elapsed from the start of charging of the assembled battery 3 may be the start of the cooling period.

  The cooling means is not limited to the blower fan 8 and may be a water cooling mechanism that supplies cooling water to the assembled battery 3.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Traveling motor 3 Assembly battery (Vehicle assembly battery)
4 Charging circuit 8 Blower fan (cooling means)
10 External power supply 21 Control unit (pause control means, temperature difference monitoring means)
22 Battery temperature sensor (battery temperature detection means)
24 Charging lamp (charging indicator)

Claims (2)

Vehicle assembled battery for accumulating electric power supplied to a vehicle driving motor, a charging circuit for connecting the external power source provided outside the vehicle and the vehicle assembled battery, and cooling for cooling the vehicle assembled battery A charging control device for controlling charging from the external power source to the assembled battery for a vehicle.
Battery temperature detection means for detecting surface temperatures at a plurality of positions in the vehicle battery pack;
In-charging notification means for notifying that the vehicle battery pack is being charged from the external power source,
At the start of charging from the external power source to the assembled battery for the vehicle, the notification that charging is in progress by the charging informing means is started, and the temperature detected by the battery temperature detecting means is referred to, and at least When the surface temperature at one position is equal to or higher than a predetermined temperature, the charging circuit is controlled while continuing the notification that charging is being performed by the charging informing means during a predetermined suspension period after the start of charging. And a suspension control means for halting charging from the external power source to the assembled battery for vehicles. Temperature difference monitoring means for monitoring a temperature difference between the lowest temperature and the highest temperature detected by the battery temperature detection means;
The charge control device for an assembled battery for a vehicle according to claim 1, wherein the suspension period starts when a temperature difference monitored by the temperature difference monitoring means reaches a predetermined value or more.

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