JP6414038B2 - Battery system - Google Patents

Description

  The present invention relates to a battery system that is mounted on an electric vehicle and includes a chargeable / dischargeable battery.

  2. Description of the Related Art Conventionally, an electric vehicle that travels with power output from a rotating electrical machine is known. Such an electric vehicle is equipped with a battery system including an in-vehicle battery that supplies electric power to the rotating electrical machine. The battery system includes a chargeable / dischargeable battery, a charger that charges the battery with electric power from an external power source, a heater that raises the temperature of the battery, a controller that controls the charger and the heater, and the like. The control device is connected to the auxiliary battery via a power relay, and when the power relay is turned on, power is supplied to the control device and the control device is activated.

  Here, although a control apparatus is comprised with various electronic components, this electronic component deteriorates gradually with electricity supply. Therefore, it is desirable to reduce the total startup time (integrated energization time) of the control device in order to prevent a decrease in the life of the control device.

  Patent Document 1 discloses a technique for adjusting the temperature of a battery while the vehicle is not in use with the ignition switch turned off. Patent Document 1 discloses a technique for predicting a time when the battery temperature becomes lower than a predetermined temperature, turning off the power of the temperature controller (control device) until the predicted time, and setting the sleep state. In Patent Document 1, when the temperature controller is restarted, if the battery temperature is equal to or higher than the predetermined temperature, the time when the battery temperature becomes lower than the predetermined temperature is predicted again, and then the power source of the temperature controller is turned on. Turn off. According to such a technique, the total activation time of the control device can be reduced, and thus the life of the control device can be extended.

JP 2012-190686 A

  By the way, in order to prevent the life of the battery system from being reduced, it is necessary to reduce not only the total activation time of the control device but also the number of activations. That is, when starting or stopping the control device, it is necessary to turn on or off the power relay described above. However, normally, the total number of power relays that can be turned on / off is determined. Therefore, if the number of activations of the control device is large, the number of times the power relay is turned on / off also increases, and the power relay, and thus the battery system, reaches an early life.

  In the case of a configuration in which the next activation time of the control device is calculated based on the estimated value of the battery temperature and the like, and then the control device is put to sleep until the next activation time as in the prior art, the total activation time of the control device can be reduced. However, in the prior art, sufficient consideration has not been given to the number of activations of the control device. In particular, as in Patent Document 1, when the control device is restarted (released from sleep), when the temperature rise or charging is not required, the control device is started and started when the control device is put to sleep again. The number of stops may increase significantly. In this case, the power relay reaches the end of its life early, and as a result, the life of the battery system decreases.

  Therefore, an object of the present invention is to provide a battery system that can further improve the life.

  The battery system of the present invention controls a battery mounted on a vehicle, a charging mechanism that charges the battery with electric power from an external power source, a temperature raising mechanism that raises the temperature of the battery, and the charging mechanism and the temperature raising mechanism. A control device that is in a plug-in connection state in which the battery is connected to an external power source and that enters a sleep state that is activated and stopped during the period in which the temperature increase and charging are not required, and the control device in the sleep state The control device, in the plug-in connection state, before the transition to the sleep state, the control device estimates a remaining time until the next restart, the remaining time in advance When the specified threshold time is exceeded, the sleep state is started and stopped. When the remaining time is less than the threshold time, the sleep state is entered. Maintaining the Rukoto without activation state, characterized in that.

  According to the present invention, when the remaining time is long, the control device is put to sleep, and when the remaining time is short, the control device is continuously started. Can be suppressed. As a result, it is possible to further improve the life of the control device, and thus the battery system.

It is a figure which shows the structure of the battery system which is embodiment of this invention. It is a figure which shows the example of control at the time of intermittent temperature rising. It is a figure which shows the example of control at the time of charge reservation. It is a flowchart which shows the flow of control in a plug-in state. It is a flowchart which shows the flow of control in a plug-in state. It is a flowchart which shows the flow of control in a plug-in state. It is a figure which shows the other example of control at the time of charge reservation. It is a figure which shows the example of the conventional control at the time of intermittent temperature rising.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a battery system 10 according to an embodiment of the present invention.

  The battery system 10 is mounted on an electric vehicle such as a hybrid vehicle or an electric vehicle. The main battery 12 is a chargeable / dischargeable secondary battery. The main battery 12 is configured, for example, by connecting a plurality of single cells in series or in parallel. The unit cell constituting the main battery 12 is not particularly limited as long as it is a chargeable / dischargeable secondary battery, and for example, a lithium ion battery or a nickel hydrogen battery can be used. In addition, an electric double layer capacitor can be used instead of the secondary battery.

  A rotating electrical machine (not shown) that outputs driving power for a vehicle is connected to the main battery 12 via a PCU (power control unit, not shown) configured by an inverter, a DC / DC converter, and the like. . The PCU boosts the power from the main battery 12 and converts it into AC power before supplying it to the rotating electrical machine. Thus, the rotating electrical machine functions as a motor and outputs driving power. Further, the PCU steps down the electric power generated by the rotating electric machine and converts it into DC power, and then outputs it to the main battery 12. In this case, the main battery 12 is charged with electric power generated by the rotating electrical machine.

  A DC / DC converter 14 is also connected to the main battery 12. The DC / DC converter 14 steps down the power output from the main battery 12 and supplies it to the auxiliary battery 16 and other auxiliary machines. The DC / DC converter 14 is controlled by a control device 28 described later.

  The main battery 12 is further connected to a charging mechanism that charges the main battery 12 with power from the external power source 100. The charging mechanism includes a charger 18, a charging relay 20, an inlet 22, and the like. The charger 18 converts AC power supplied from the external power supply 100 into DC power. A charging relay 20 is provided between the main battery 12 and the charger 18. Charging relay 20 is switched between on and off in response to a control signal from control device 28. An inlet 22 is connected to the charger 18. This inlet 22 is a connector to which the charging plug 102 of the external power source 100 can be attached and detached. The control device 28 monitors the connection state between the inlet 22 and the charging plug 102. Hereinafter, a state where the inlet 22 and the charging plug 102 are connected is referred to as a “plug-in state”, and a state where the inlet 22 and the charging plug 102 are not connected is referred to as a “plug-out state”.

  When the charging relay 20 is on in the plug-in state, AC power from the external power source 100 is converted into DC power by the charger 18 and then supplied to the main battery 12. Thereby, the main battery 12 is charged with external power. The operations of the charger 18 and the charging relay 20 are controlled by the control device 28.

  The battery system 10 is further provided with a temperature raising mechanism for raising the temperature of the main battery 12. That is, when the temperature of the main battery 12 decreases, the charging time Ac becomes longer due to a decrease in chargeable capacity and a decrease in allowable input current. Moreover, when the main battery 12 falls to freezing temperature, there exists a characteristic that it becomes impossible to charge / discharge. Therefore, a temperature raising mechanism is provided for raising the temperature of the main battery 12 when the main battery 12 is at a low temperature.

  The temperature raising mechanism includes a heater 24 and a temperature raising relay 26. The heater 24 is provided in the vicinity of the main battery 12. In addition, the heater 24 may be single or plural. The charging relay 20 is provided in a current path between the DC / DC converter 14 and the heater 24. The temperature raising relay 26 is switched between on and off in response to a control signal from the control device 28. When the temperature raising relay 26 is turned on, predetermined power is supplied from the DC / DC converter 14 to the heater 24, and the heater 24 can generate heat. And when the heater 24 generates heat, the main battery 12 is heated.

  A first temperature sensor 30 is also provided in the vicinity of the main battery 12. The first temperature sensor 30 is a sensor that measures the temperature of the main battery 12. The detection value of the first temperature sensor 30 is input to the control device 28 as the battery temperature TB. The first temperature sensor 30 may be one or plural. When a plurality of first temperature sensors 30 are provided, a statistical value calculated from a plurality of detected values, for example, an average value, a minimum value, a maximum value, or the like may be used as the battery temperature TB.

  A second temperature sensor 32 for measuring the environmental temperature α is provided at a position away from the main battery 12. The second temperature sensor 32 is provided, for example, outside the passenger compartment or in the refrigerant intake path for cooling the main battery 12. The detected value of the second temperature sensor 32 is input to the control device 28 as the environmental temperature α.

  The battery system 10 is further provided with a voltage sensor and a current sensor (both not shown) for measuring the voltage (battery voltage VB) and current (battery current IB) of the main battery 12. Control device 28 calculates the SOC of main battery 12 based on battery voltage VB, battery current IB, etc. detected by these sensors. The SOC is a parameter indicating the ratio of the current charge capacity to the full charge capacity of the main battery 12.

  The reservation UI 34 is a user interface that accepts user instructions, and includes, for example, a display device that presents various types of information to the user, and an input device that accepts user operation input. A liquid crystal panel or the like corresponds to the display device, and a selection button, a rotary switch, or the like corresponds to the input device. The reservation UI 34 may be configured by a touch panel or the like in which a display device and an input device are integrated. When it is desired to set a charge reservation to be described later, the user operates the reservation UI 34 to set a time (charge end time te) at which charging is desired to be completed. A user instruction input via the reservation UI 34 is input to the control device 28.

  The control device 28 controls charging / discharging of the main battery 12, and controls a charging mechanism, a temperature raising mechanism, and the like. For example, the control device 28 calculates an allowable value of input / output power to the main battery 12 based on various parameters, and charges the main battery 12 so that the actual input / output power of the battery does not exceed the allowable value. Control the discharge. Further, the control device 28 monitors the connection state between the charging plug 102 and the inlet 22 and drives the charging mechanism and the temperature raising mechanism as necessary to charge the main battery 12 or raise the temperature. . A power relay 29 is provided in the current path between the control device 28 and the DC / DC converter 14. When the power supply relay 29 is turned on, power is supplied to the control device 28 and the control device 28 is activated.

  The activation device 36 turns on the power supply relay 29 that has been turned off. That is, as will be described in detail later, in the present embodiment, the control device 28 sets the next activation time ts in the activation device 36 as necessary, and then shifts to a sleep state in which the power supply relay 29 is turned off. When the activation device 36 reaches the set next activation time ts, the activation device 36 turns on the power relay 29 to restart the control device 28 that has entered the sleep state. The activation device 36 has a built-in battery 38 and a timer 40 and is driven by the power of the built-in battery 38. In other words, even if the power supply relay 29 is turned off, the activation device 36 can continue to be activated. Further, the configuration of the activation device 36 is simpler than that of the control device 28, and the energization time (total life) in which the activation device 36 can be normally driven is sufficiently longer than that of the control device 28.

  Next, the operation of the battery system 10 in the plug-in state will be described. When the user wants to externally charge the main battery 12, the user inserts the charging plug 102 into the inlet 22 to set the plug-in state. When in the plug-in state, the control device 28 drives the charging mechanism and the temperature raising mechanism to charge the main battery 12 and raise the temperature.

  In order to perform the charging and the temperature increase, the control device 28 stores a charge reference value Cdef, a temperature increase start temperature Ts, and a temperature increase stop temperature Te in advance. The charging reference value Cdef is a SOC value that allows the main battery 12 to be considered fully charged, and is, for example, a value of about 80 to 90%. In the plug-in state, control device 28 supplies power to main battery 12 until the SOC reaches charge reference value Cdef. The temperature rise start temperature Ts is a value set according to the property of the main battery 12 and the like, for example, a value around 0 ° C. can be set. The temperature increase stop temperature Te is a value obtained by adding a slight hysteresis (for example, several degrees Celsius) to the temperature increase start temperature Ts. The controller 28 starts the temperature increase if the battery temperature TB is lower than the temperature increase start temperature Ts, and ends the temperature increase if the battery temperature TB reaches the temperature increase stop temperature Te.

  By the way, control of charge and temperature rise in the plug-in state differs depending on the presence or absence of “charge reservation”. The charge reservation means that the user designates the charge end time te. When the user wishes to make a charge reservation, the user sets the time (charge end time te) at which he wants the external charging of the main battery 12 to be completed via the reservation UI 34.

  When this charge reservation is set, the control device 28 estimates the charge start time tc and the temperature rise start time tw at which the charge and temperature rise of the main battery 12 are completed at the charge end time te. Charging and heating start from the specified time. On the other hand, when the charge reservation is not set, the control device 28 performs charging immediately and continues the intermittent temperature increase until the plug-out state is reached. In the intermittent temperature increase, the process of driving the heater 24 is repeated when the battery temperature TB is lower than the temperature increase start temperature Ts, and the process of stopping the heater 24 is repeated when the battery temperature TB is equal to or higher than the temperature increase stop temperature Te.

  In order to perform the processing as described above, the control device 28 naturally monitors the control parameters such as the battery temperature TB, the battery voltage, and the battery current, and determines whether the charging mechanism or the temperature raising mechanism needs to be driven. . However, the plug-in state described above often continues for a relatively long time. For example, in the case of a user who uses a vehicle for commuting, the user may leave the plug-in state for about ten hours before going to work the next morning after returning home in the evening. If the control device 28 is always activated during the plug-in state, the accumulated energization time (integrated activation time) of the control device 28 increases. The control device 28 composed of various electronic components such as a CPU has a certain energization time (total life) that can be normally operated. If the control device 28 continues to start unnecessarily, the control device 28 is relatively early. Becomes unusable.

  In order to avoid such a problem, some techniques have been proposed in which a time at which the control device 28 needs to be activated is estimated and the control device 28 is activated and stopped (sleep) until the estimated time. In such a technique, when the control device 28 is activated, the control device 28 estimates the time when the temperature rise or charging is required as the next activation time ts. If the next activation time ts can be estimated, the control device 28 is deactivated (sleep) until that time. When the next activation time ts is reached, the control device 28 is restarted. Then, if necessary, temperature increase or charging is started. If unnecessary, the next activation time ts is estimated again, and the control device 28 is put to sleep.

  FIG. 8 is a diagram showing an operation example in the case where intermittent temperature rise is performed by such a conventional technique. In FIG. 8, the upper row shows the battery temperature TB, the middle row shows the on / off status of the heater 24, and the lower row shows the on / off status of the control device 28. In the upper part of FIG. 8, the solid line indicates the actual battery temperature TB (actual temperature), and the broken line indicates the battery temperature (estimated temperature TB *) estimated by the control device 28.

  When performing the intermittent temperature increase, the control device 28 turns on the heater 24 if the battery temperature TB becomes lower than the temperature increase start temperature Ts. Therefore, at time t0, the control device 28 estimates the time when the battery temperature TB becomes lower than the temperature rise start temperature Ts, and sets the time as the next activation time ts. In the example of FIG. 8, at time t0, the control device 28 estimates time t1 as the next activation time ts. If the next activation time ts = t1 can be estimated, the control device 28 shifts to the sleep state where the activation is stopped. Thereafter, when time t1 is reached, the control device 28 restarts and determines whether or not the temperature needs to be raised. In the example of FIG. 8, since the battery temperature TB is lower than the temperature increase start temperature Ts at time t1, the control device 28 turns on the heater 24 and starts temperature increase.

  When the temperature increase is completed at time t2, control device 28 again estimates the time when battery temperature TB becomes lower than temperature increase start temperature Ts. In the example of FIG. 8, at time t2, the control device 28 estimates time t3 as the next activation time ts. Thereafter, the control device 28 turns off the power supply relay 29 and shifts to the sleep state where the activation is stopped. When the time t3 is reached, the control device 28 is restarted. Here, at the time t3, the restarted control device 28 determines whether or not it is necessary to raise the temperature. In the example of FIG. 8, since the battery temperature TB is equal to or higher than the temperature increase start temperature Ts at time t3, it can be determined that the temperature increase is unnecessary. In this case, the control device 28 again estimates the next activation time ts = t4 and sleeps until that time. In the example of FIG. 8, the control device 28 estimates the time t4 as the next activation time ts at the time t3, and sleeps until the time t4. At time t4 when the control device 28 is restarted, if it is not necessary to raise the temperature, the next activation time ts = t5 is estimated again and the sleep is performed until that time.

  As is clear from the above description, according to the prior art shown in FIG. 8, since the control device 28 is started and stopped until the temperature rise is necessary, the energization time of the control device 28 can be greatly shortened. However, in this prior art, when the actual battery temperature TB is higher than the estimated temperature TB * at the time of restart, the state shifts to the sleep state again. Therefore, according to the prior art, there arises a new problem that the number of on / off switching of the power relay 29 that allows / stops energization of the control device 28 increases.

  That is, the control device 28 is switched on and off by switching on and off the power relay 29 interposed between the control device 28 and the power source. However, the number of times that the relay can normally be switched on and off is determined to some extent. Therefore, when the number of times of turning on / off the power relay 29 increases, the power relay 29 reaches the end of life relatively early, and as a result, the control device 28 becomes unusable relatively early.

  Therefore, in the present embodiment, when the control device 28 is activated, the time until the next charging and temperature increase is estimated as the remaining time Ar, and when this remaining time Ar is long, the control device 28 28 is put to sleep, but if the remaining time Ar is short, the control device 28 is kept running without being put to sleep. Thereby, it is possible to suppress an increase in the number of on / off switching of the power relay 29 while shortening the energization time of the control device 28.

  Specifically, control of intermittent temperature increase in the present embodiment will be described. FIG. 2 is a diagram showing an example of intermittent temperature rise control in this embodiment. The upper row shows the battery temperature TB, the middle row shows the on / off status of the heater 24, and the lower row shows the on / off status of the control device 28. ing. In FIG. 2, the solid line indicates the actual battery temperature TB, and the broken line indicates the battery temperature TB estimated by the control device 28 (estimated temperature TB *). In FIG. 2, it is assumed that the times Ar1 and Ar2 are larger than the predetermined threshold time Ath, and the time Ar3 is smaller than the threshold time Ath (Ar3 <Ath <(Ar1, Ar2)).

In the intermittent temperature increase, the control device 28 calculates the time until the next temperature increase is required, that is, the remaining time Ar until the battery temperature TB becomes lower than the temperature increase start temperature Ts. To do. The remaining time Ar can be estimated based on the battery temperature TB and the environmental temperature α. The control device 28 stores a map or an arithmetic expression indicating the correspondence between these parameters TB, α and the remaining time Ar, and the control device 28 converts the values of these parameters TB, α into a map or an arithmetic expression. Accordingly, the remaining time Ar is calculated. A map showing the correspondence between the parameters TB, α and the remaining time Ar can be created based on, for example, experiments or simulation results. Further, as an arithmetic expression indicating the correspondence between the parameters TB, α and the remaining time Ar, for example, Expression 1 can be used. In Equation 1, K is a variable indicating the amount of decrease in the battery temperature TB per unit time, and varies according to the difference between the environmental temperature α and the battery temperature TB. This variable K is obtained in advance by experiments or the like.
Ar = (TB−Ts) / K Equation 1

  In the example of FIG. 2, at time t0, the control device 28 estimates the time Ar1 as the remaining time. If the remaining time Ar = Ar1 can be calculated, the control device 28 compares the remaining time Ar = Ar1 with a predetermined threshold time Ath. The threshold time Ath is a predetermined time and indicates an allowable error amount of the remaining time. As the threshold time Ath, for example, about 15 minutes to 45 minutes can be set. If the remaining time Ar = Ar1 exceeds the threshold time Ath as a result of the comparison, the control device 28 sets the time obtained by adding the remaining time Ar = Ar1 to the current time (t0) as the next activation time ts to the activation device 36. After the setting, the power supply relay 29 is turned off to start and stop (sleep). The activation device 36 monitors the time and turns on the power relay 29 to activate the control device 28 when the set time t1 is reached.

  The restarted control device 28 confirms the battery temperature TB at time t1. In the illustrated example, since the battery temperature TB is lower than the temperature rise start temperature Ts at time t1, the control device 28 turns on the heater 24 to raise the temperature of the main battery 12. As a result of the temperature rise, if the battery temperature TB reaches the temperature rise stop temperature Te at time t2, the control device 28 turns off the heater 24. Then, the remaining time Ar is estimated again.

  In the illustrated example, at time t2, the control device 28 estimates the time Ar2 as the remaining time Ar. Since the remaining time Ar = Ar2 exceeds the threshold time Ath, similarly to the time t0, the control device 28 sets the time obtained by adding the remaining time Ar = Ar2 to the current time (t2) as the next activation time ts. After setting the starter 36, the power supply relay 29 is turned off to stop (sleep).

  At time t3, the activation device 36 turns on the power supply relay 29 to activate the control device 28. The restarted control device 28 confirms the battery temperature TB at the time t3, similarly to the time t1. In the illustrated example, the battery temperature TB is equal to or higher than the temperature rise start temperature Ts at time t3. In this case, the control device 28 again estimates the remaining time Ar, that is, the time until the battery temperature TB next becomes lower than the temperature rise start temperature. In the illustrated example, at time t3, the control device 28 estimates the time Ar3 as the remaining time Ar.

  Here, the remaining time Ar = Ar3 is less than the threshold time Ath. Therefore, in this case, the control device 28 continues to start without stopping (sleeping) at time t3. Then, at time t3, the heater 24 is turned on, and the main battery 12 starts to be heated. Thus, when the remaining time Ar until the next activation time ts is short, the number of times the power supply relay 29 is turned on and off can be reduced by continuing the activation without causing the control device 28 to sleep.

  Next, the control when the charge reservation in this embodiment is set will be described. FIG. 3 is a diagram illustrating an example of control when a charge reservation is set in the present embodiment. The upper row shows estimated values of the charging time Ac and the temperature rising time Aw, and the lower row shows the on / off status of the control device 28. Respectively. In FIG. 3, it is assumed that the times Ar1 and Ar2 are larger than the threshold time Ath and the time Ar3 is smaller than the threshold time Ath (Ar3 <Ath <(Ar1, Ar2)).

When the charge reservation is set, the control device 28 obtains the time required for charging (charge time Ac) and the time required for temperature increase (temperature increase time Aw). The temperature increase time Aw is obtained from parameters such as the temperature increase stop temperature Te, the current battery temperature TB, the environmental temperature α, and the remaining time from the current time tn to the charge end time te (reservation duration Am). Can do. The control device 28 stores a map or an arithmetic expression indicating a correspondence relationship between these parameters and the temperature increase time Aw, and the control device 28 stores the values of various parameters actually detected in the map or the calculation. By applying the equation, the heating time Aw is calculated. A map indicating the correspondence between various parameters and the temperature increase time Aw can be created based on, for example, experiments or simulation results. In addition, as an arithmetic expression indicating the correspondence between various parameters and the temperature increase time Aw, for example, Expression 2 or the like can be used. In Expression 3, B and C are predetermined constants.

  The charging time Ac is a total value of the first charging time Ac1 and the second charging time Ac2. The first charging time Ac1 is the time required to charge from the SOC at the time of plug-in connection to the SOC (charge reference value Cdef) that can be regarded as full charge. As a general rule, the SOC and the charge reference at the time of plug-in connection It is calculated based on the difference value from the value Cdef. In other words, the first charging time Ac1 does not vary with the battery temperature TB or the environmental temperature α.

  The second charging time Ac2 is a time required for charging for replenishing electric power required for temperature increase. That is, when the temperature of the main battery 12 is increased by the heater 24, extra power is required according to the temperature increase time Aw (power consumption of the heater 24). The second charging time Ac2 is a time required to charge this extra necessary power. The second charging time Ac2 is a value calculated based on the temperature raising time Aw, and is a value that varies depending on the battery temperature TB and the environmental temperature α.

  In the example of FIG. 3, the control device 28 estimates the temperature increase time Aw and the charge time Ac at time t0, time t1, and time t2, but at each time, the battery temperature TB and environmental temperature are estimated. α is changing. Therefore, the temperature rising time Aw and the second charging time Ac2 change at each time.

If the temperature raising time Aw and the charging time Ac can be calculated, the control device 28 obtains the remaining time Ar until the next activation time ts. The remaining time Ar is calculated by the following equation 3. In Equation 4, Am is the reservation duration Am and is the time from the current time tn to the charging end time te. Further, max () is a function that returns the maximum value of the argument, and max (Ac, Aw) indicates the higher value of Ac and Aw.
Ar = Am-max (Ac, Aw) Equation 3

  When the remaining time Ar is obtained, the control device 28 compares the remaining time Ar with the threshold time Ath. If the remaining time Ar exceeds the threshold time Ath, the control device 28 sets the next activation time ts in the activation device 36 and sleeps. On the other hand, if the remaining time Ar is equal to or less than the threshold time Ath, the control device 28 continues to start without sleeping.

  A specific control flow will be described with reference to FIG. In the example of FIG. 3, time te is set as the charging end time. If the plug-in connection is made at time t0, the control device 28 estimates the remaining time Ar. Specifically, the temperature increase time Aw is estimated, and the charge time Ac is estimated based on the temperature increase time Aw, the SOC, and the like. Furthermore, if charging time Ac and temperature raising time Aw are obtained, control device 28 obtains remaining time Ar based on Equation 3. In the illustrated example, at time t1, the control device 28 estimates the time Ar1 as the remaining time Ar. Then, the control device 28 compares the calculated remaining time Ar = Ar1 with the threshold time Ath. In the example of FIG. 3, at time t1, the remaining time Ar = Ar1 is longer than the threshold time Ath. In this case, after setting the time (t1) obtained by adding the remaining time Ar1 to the current time (t0) to the starter 36 as the next start time ts, the control device 28 turns off the power supply relay 29 and sleeps.

  When the time t1 is reached, the activation device 36 turns on the power supply relay 29 and restarts the control device 28. The restarted control device 28 calculates the temperature increase time Aw and the second charge time Ac2 based on the battery temperature TB and the environmental temperature α at the time of restart. Note that the first charging time Ac1 does not need to be recalculated because it does not vary with the battery temperature TB or the environmental temperature α as described above. If the temperature increase time Aw and the second charging time Ac2 can be calculated, the control device 28 calculates the remaining time Ar again based on these values. In the illustrated example, the time Ar2 is estimated as the remaining time Ar. Then, the calculated remaining time Ar = Ar2 is compared with the threshold time Ath. Since the remaining time Ar = Ar2 is larger than the threshold time Ath, the control device 28 sets the next activation time ts (t2 = t1 + Ar2) in the activation device 36 again, and then turns off the power supply relay 29 to sleep.

  When the time t2 is reached, the activation device 36 turns on the power supply relay 29 and restarts the control device 28. The restarted control device 28 calculates the remaining time Ar = Ar3 again and compares it with the threshold time Ath. Since the remaining time Ar = Ar3 is equal to or less than the threshold time Ath, the control device 28 continues to start without sleeping at time t2. Then, charging starts at time t2.

  As described above, even when the charge reservation is set, the control device 28 calculates the remaining time Ar until the next charging or temperature increase starts, and when the remaining time Ar is long, the controller 28 sleeps and is short. In case, continue to start as it is. As a result, it is possible to suppress an increase in the number of on / off switching of the power relay 29 while shortening the energization time of the control device 28.

  Next, the flow of control in this embodiment will be described with reference to FIGS. 4 to 6 are flowcharts showing the flow of control when plug-in connection is made. 4 to 6, the thick line blocks indicate processes performed by the activation device 36, and the other blocks indicate processes performed by the control device 28.

  As shown in FIG. 4, when plug-in connection is established (Yes in S10), the control device 28 confirms whether or not there is a charge reservation (S12). When the charge reservation is set, the process proceeds to step S14 (FIG. 5), and the charge reservation control is executed.

  On the other hand, when the charge reservation is not set, the control device 28 starts charging the main battery 12 (S16). Specifically, the control device 28 turns on the charging relay 20 and supplies the power of the external power source 100 to the main battery 12. During charging, the control device 28 monitors the battery voltage, the battery current, the battery temperature TB, and the like, and calculates the SOC of the main battery 12 based on these values. If the SOC of the main battery 12 reaches the charging reference value Cdef that can be regarded as fully charged (Yes in S18), the control device 28 turns off the charging relay 20 and ends the charging (S20).

  After the charging is completed, the control device 28 performs intermittent temperature increase. Specifically, the control device 28 first acquires the current time tn (S22). Subsequently, the current battery temperature TB and environmental temperature α are acquired, and based on these values, the remaining time Ar until the next temperature increase starts is calculated (S24). This remaining time Ar can be calculated, for example, by applying the battery temperature TB, the environmental temperature α, and the like to Equation 1.

  If the remaining time Ar can be calculated, the control device 28 then compares the remaining time Ar with the threshold time Ath (S26). As a result of the comparison, when the remaining time Ar exceeds the threshold time Ath, the control device 28 calculates the next activation time ts (S28). The next activation time ts is obtained by adding the remaining time Ar to the current time tn. When the next activation time ts is obtained, the control device 28 sets the time in the activation device 36 and then turns off the power supply relay 29 to sleep (S30, S32).

  The activation device 36 compares the current time tn with the next activation time ts (S34), and when the current time tn reaches the next activation time ts, the power relay 29 is turned on to restart the control device 28 ( S36). The restarted control device 28 returns to step S22 and again acquires the current time tn, calculates the remaining time Ar, and the like.

  On the other hand, when the remaining time Ar becomes equal to or shorter than the threshold time Ath in step S26, the control device 28 turns on the heater 24 and starts increasing the temperature of the main battery 12 (S38). If the battery temperature TB is equal to or higher than the temperature increase stop temperature Te as a result of the temperature increase (Yes in S40), the control device 28 turns off the heater 24 and stops the temperature increase (S42). Then, the process returns to step S22, and thereafter the same processing is repeated. Although not shown in the flowchart, the intermittent temperature increase process is forcibly terminated when the plug 22 is disconnected from the inlet 22 with the charging plug 102 removed.

  On the other hand, a case where a charge reservation is set in step S12 will be described. In this case, as shown in FIG. 5, the control device 28 first acquires the current time tn and the charging end time te (S44). Then, the difference value between the current time tn and the charging end time te is calculated as the reservation duration Am (S46).

  Next, the control device 28 acquires the current battery temperature TB and the environmental temperature α, and calculates the temperature increase time Aw based on these values (S48). The temperature increase time Aw can be calculated by applying the battery temperature TB, the environmental temperature α, the reservation duration Am, and the like to Equation 2.

  If the temperature raising time Aw can be calculated, the control device 28 calculates the charging time Ac (S50). As described above, the charging time Ac is an added value of the first charging time Ac1 and the second charging time Ac2. The first charging time Ac1 is obtained from the difference value between the SOC of the main battery 12 and the reference charging value. The second charging time Ac2 is obtained from the temperature raising time Aw and the power consumption per unit time of the heater 24.

  If the temperature increase time Aw and the charge time Ac can be calculated, the control device 28 calculates the remaining time Ar until the next temperature increase or charge starts (S52). The remaining time Ar is calculated based on Equation 3 as described above. Then, the control device 28 compares the calculated remaining time Ar with the threshold time Ath (S54). As a result of the comparison, when the remaining time Ar is larger than the threshold time Ath, the control device 28 calculates the next activation time ts (S56). Then, the control device 28 sets the next activation time ts in the activation device 36 and then turns off the power supply relay 29 to sleep (S58, 60). The activation device 36 compares the current time with the next activation time ts (S62). When the current time reaches the next activation time ts, the power supply relay 29 is turned on and the control device 28 is activated again (S64). . The restarted control device 28 returns to step S44 and again calculates the remaining time Ar.

  On the other hand, when the remaining time Ar is equal to or shorter than the threshold time Ath in step S54, the control device 28 proceeds to step S66 (FIG. 6). In step S66, the control device 28 confirms which of the temperature raising time Aw and the charging time Ac is longer. As a result of the confirmation, if the charging time Ac is longer, the process proceeds to step S68 and charging is started. That is, the control device 28 turns on the charging relay 20 and supplies power from the external power source 100 to the main battery 12. In parallel with this charging, the control device 28 checks whether or not the current time tn has reached the temperature rise start time tw = te−Aw (S70). When the current time tn has reached the temperature increase start time tw, the control device 28 turns on the heater 24 and starts temperature increase of the main battery 12 (S72). Finally, when the temperature rise and charge are completed (Yes in S80), the charge and temperature rise are stopped (S82).

  On the other hand, if the temperature increase time Aw is longer than the charge time Ac in step 66, the process proceeds to step S74, and the temperature increase is started. That is, the control device 28 turns on the heater 24 and raises the temperature of the main battery 12. In parallel with this temperature increase, the control device 28 checks whether or not the current time tn has reached the charging start time tc = te−Ac (S76). If the current time tn has reached the charging start time tc, the charging relay 20 is turned on to supply power from the external power source 100 to the main battery 12 (S78). Finally, when the temperature rise and charge are completed (Yes in S80), the charge and temperature rise are stopped (S82).

  As is apparent from the above description, in the present embodiment, the remaining time Ar until the next temperature increase or charging is estimated is estimated. If the remaining time Ar is long (Yes in S26 and S54), the control device 28 When the remaining time Ar is short (No in S26 and S54), the control device 28 continues to be activated without sleeping. As a result, the energization time of the control device 28 can be significantly shortened, and an increase in the number of on / off switching of the control device 28 can be suppressed. As a result, deterioration of both the control device 28 itself and the power supply relay 29 can be effectively prevented, and the time when the control device 28 cannot be used normally can be delayed.

  The configuration described so far is merely an example, and when the remaining time Ar is short, other configurations may be appropriately changed as long as the control device 28 is continuously started without sleeping. For example, in the present embodiment, when the remaining time Ar is short, charging or temperature increase is started immediately. However, as long as the control device 28 continues to be activated, the charging and the temperature increase need not be started. For example, when the remaining time Ar is short, the controller 28 may monitor the battery temperature TB and the like while starting up, and may continue to update the remaining time Ar as needed based on the battery temperature TB and the like. When the remaining time Ar becomes zero, the temperature rise or charging may be started.

  In the present embodiment, the control device 28 is always put to sleep when the remaining time Ar is larger than the threshold time Ath. However, if the control device 28 is restarted a certain number of times, for example, twice, the control device 28 may continue to be started without sleeping even if the remaining time Ar exceeds the threshold time Ath. . This will be described with reference to FIG. In FIG. 7, all the times Ar1 to Ar4 are greater than the threshold time Ath. As shown in FIG. 7, when the estimated remaining times Ar2 and Ar3 are larger than the threshold time Ath at the first restart (time t1) and the second restart (time t2), control is performed. The device 28 is put to sleep, but at the time of the third restart (time t3), even if the estimated remaining time Ar4 is longer than the threshold time Ath, the control device 28 is started without sleeping. Continue to let. With this configuration, it is possible to more effectively prevent the power relay 29 from being frequently switched on and off.

  In the present embodiment, the environmental temperature α is detected by the second temperature sensor 32. However, the second temperature sensor 32 may be omitted, and the environmental temperature α may be estimated from various parameters. There are various methods for estimating the environmental temperature α. For example, the environmental temperature α may be estimated based on an error between the detected value of the battery temperature TB and the estimated value. Specifically, the control device 28 calculates the estimated value TB * of the battery temperature after a predetermined time has elapsed based on the estimated value α * of the environmental temperature α and the battery temperature TB. Then, after the elapse of a predetermined time, the actually detected battery temperature TB is compared with the estimated value TB *. If the estimated value TB * is higher than the battery temperature TB, the estimated value α * is increased and the estimated value TB is increased. If * is lower than the battery temperature TB, the process of decreasing the estimated value α * may be repeated so that the estimated value α * approaches the actual environmental temperature α.

  Moreover, in this embodiment, although the starting device 36 is driven with the electric power of the internal battery 38, the starting device 36 may be driven with other electric power. For example, the starting device 36 may be configured to be always connected to the auxiliary battery 16 and the starting device 36 may be driven by the power of the auxiliary battery 16.

10 Battery System, 12 Main Battery, 14 DC / DC Converter, 16 Auxiliary Battery, 18 Charger, 20 Charge Relay, 22 Inlet, 24 Heater, 26 Heating Relay, 28 Control Device, 29 Power Relay, 30 First Temperature Sensor, 32 Second temperature sensor, 34 Reservation UI, 36 Start-up device, 38 Built-in battery, 40 Timer, 100 External power supply, 102 Charging plug.

Claims (1)

A battery mounted on the vehicle;
A charging mechanism for charging the battery with power from an external power source;
A temperature raising mechanism for raising the temperature of the battery;
A control device for controlling the charging mechanism and the temperature raising mechanism, wherein the battery is connected to an external power source in a plug-in connection state, and is controlled to enter a sleep state in which the temperature raising and charging are not required during the period during which the temperature raising and charging are not required. Equipment,
An activation device for restarting the control device in the sleep state;
With
In the plug-in connection state, the control device estimates a remaining time until the next restart before shifting to the sleep state, and starts when the remaining time exceeds a predetermined threshold time Transition to the stopped sleep state, if the remaining time is less than or equal to the threshold time, maintain the activation state without shifting to the sleep state,
A battery system characterized by that.