JP5928385B2 - Power storage system - Google Patents

Description

  The present invention relates to a technique for estimating a temperature (standby temperature) when a power storage device is not charged / discharged.

  Patent Document 1 describes that a deterioration rate of a power storage unit is calculated based on a temporal change in battery temperature. Here, the battery temperature includes the battery temperature during the leaving period, and the battery temperature during the leaving period is estimated from the heat radiation amount of the power storage unit. The neglected period is a period from when the external charging is completed until the ignition switch is turned on.

JP 2010-035280 A

  The deterioration state of the secondary battery mounted on the vehicle depends not only on the temperature of the secondary battery when the ignition switch of the vehicle is on, but also on the temperature of the secondary battery when the ignition switch is off. In a configuration in which the temperature of the secondary battery cannot be detected when the ignition switch is off, it is necessary to estimate the temperature of the secondary battery. The present invention provides a technique for estimating the temperature of a power storage device when an ignition switch is off by a method different from that of Patent Document 1.

  The power storage system according to the present invention includes a power storage device mounted on a vehicle, an outside air temperature sensor that detects an outside air temperature outside the vehicle, and a controller. When the ignition switch of the vehicle is on, the controller detects the outside air temperature using the outside air temperature sensor while distinguishing the time zone of the day. Then, the controller estimates the leaving temperature based on the detected outside air temperature. The standing temperature is the temperature of the power storage device when the ignition switch is off.

  Since the temperature of the power storage device is affected by the outside air temperature outside the vehicle, it is possible to estimate the standing temperature of the power storage device based on the outside air temperature. Here, the outside air temperature is not constant throughout the day, but changes according to the time zone of the day. For example, the daytime outside temperature tends to be higher than the nighttime outside temperature. In the present invention, it is easy to specify the outside air temperature that is a reference when estimating the standing temperature by detecting the outside air temperature while distinguishing the time zones of the day.

  For example, if it is detected at night as the outside temperature during the day, it may be estimated to be lower than the actual measured value when the standing temperature is estimated based on the outside temperature. . In addition, if it is detected as an outside air temperature at night even though it is during the daytime, the abandoning temperature may be estimated to be higher than the actual measured value when the standing temperature is estimated based on the outside air temperature. . In the present invention, since the outside air temperature is detected while distinguishing the time zone of the day, it is possible to prevent the neglected temperature from being estimated to be high or low as described above.

  When estimating the neglected temperature, first, the traveling region of the vehicle can be specified. Specifically, by preparing in advance information indicating the correspondence between the travel area and the outside air temperature, the travel area corresponding to the detected outside air temperature can be specified. And if the outside air temperature for every traveling area is set in advance, the neglected temperature can be estimated based on the outside air temperature of the identified traveling area.

  If the outside temperature is continuously detected, the maximum temperature, the minimum temperature, and the average temperature in the first period can be calculated. In addition, the average temperature in the second period longer than the first period can be calculated. A travel region can be specified by using the temperature calculated in this way.

  Specifically, an area corresponding to the calculated temperature can be specified as a travel area by obtaining in advance information indicating the correspondence between the various temperatures and areas described above. Here, it is possible to identify the traveling region by confirming that various temperatures coincide with each other or show similar behavior.

  A temperature higher than the outside air temperature of the identified travel area can be estimated as the leaving temperature. The power storage device is mounted on a vehicle, and the temperature inside the vehicle may be higher than the temperature outside the vehicle. Therefore, it can be estimated that the standing temperature is higher than the outside air temperature in the traveling area. Here, the standing temperature can be estimated by considering the temperature difference between the inside and the outside of the vehicle. Specifically, the standing temperature can be calculated by adding the above-described temperature difference to the outside air temperature in the traveling area.

  On the other hand, the outside air temperature of the specified travel area can be estimated as the neglected temperature. When the temperature difference between the inside and the outside of the vehicle is unlikely to occur and the temperature of the power storage device is easily influenced by the outside air temperature, the outside air temperature in the traveling area can be set as the neglected temperature. Here, as the outside temperature in the travel region, the annual average temperature in the identified travel region can be used.

When estimating the in release置温degree as described above, until calculates the average temperature in the second period, it is impossible to estimate the standing temperature. Therefore, until the average temperature in the second period is calculated , the outside temperature preset as the average temperature in the second period can be used . Then, after calculating the average temperature in the second period, the standing temperature can be estimated using this average temperature .

  The power storage system can be provided with an illuminance sensor that detects the illuminance outside the vehicle. Here, if the illuminance detected by the illuminance sensor is used, day and night as a time zone can be distinguished. Specifically, if the detected illuminance is higher than a threshold value (illuminance), it can be determined as daytime. If the detected illuminance is lower than the threshold (illuminance), it can be determined that the night.

  Here, depending on the environment outside the vehicle, the detected illuminance may be lower than the threshold (illuminance) even during the daytime, or the detected illuminance may be higher than the threshold (illuminance) even at night. There is. Therefore, it is necessary to accurately distinguish day and night. Specifically, the count value is incremented when the detected illuminance is greater than or equal to a threshold value (threshold value). When the count value is equal to or larger than the threshold value (count value), it is determined that the day is noon, and when the count value is smaller than the threshold value (count value), the night is determined. By setting the count value in this way, the probability of discriminating between daytime and night can be increased.

  The battery system can be provided with a radio clock that specifies the current time using standard radio waves. If a radio clock is used, the time zone of the day can be specified. Thereby, outside temperature can be detected, distinguishing a time slot | zone.

  When the storage temperature of the power storage device is estimated, the deterioration state of the power storage device can be estimated based on the storage temperature. Specifically, if the correspondence relationship between the deterioration state and the leaving temperature is obtained in advance, the deterioration state corresponding to the estimated leaving temperature can be specified. In general, in a vehicle, the time when the ignition switch is off tends to be longer than the time when the ignition switch is on.

  Therefore, it is preferable to consider the standing temperature in estimating the deterioration state of the power storage device. Specifically, the deterioration state of the power storage device can be accurately estimated by considering not only the deterioration state when the ignition switch is on, but also the deterioration state when the ignition switch is off.

It is a figure which shows the structure of a battery system. It is a flowchart which shows the process which specifies the outdoor temperature of daytime and nighttime. It is a figure which shows the change of illumination intensity, a count value, and external temperature. It is a figure which shows the change of illumination intensity, a count value, and external temperature. It is a flowchart which shows the process which specifies the use area of an assembled battery. It is a flowchart which shows the process which estimates the leaving temperature of an assembled battery. It is a figure which shows the relationship between a leaving temperature and annual average temperature. It is a flowchart which shows the process which controls the input / output of an assembled battery. It is a figure which shows the correspondence of deterioration rate, battery temperature, and SOC.

  Examples of the present invention will be described below.

  FIG. 1 is a diagram showing a configuration of a battery system (corresponding to the power storage system of the present invention) according to the present embodiment. The battery system shown in FIG. 1 is mounted on a vehicle. Such vehicles include hybrid vehicles and electric vehicles. The hybrid vehicle includes another power source such as an internal combustion engine or a fuel cell in addition to the assembled battery described later as a power source for running the vehicle. Moreover, the electric vehicle includes only an assembled battery described later as a power source for running the vehicle.

  The assembled battery (corresponding to the power storage device of the present invention) 10 has a plurality of unit cells 11 connected in series. As the cell 11, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. In addition, an electric double layer capacitor can be used instead of the secondary battery.

  The number of the single cells 11 can be appropriately set based on the required output of the assembled battery 10 or the like. In the present embodiment, the assembled battery 10 is configured by connecting all the unit cells 11 in series, but is not limited thereto. The assembled battery 10 can include a plurality of single cells 11 connected in parallel.

  The monitoring unit 21 detects the voltage value Vb of the assembled battery 10 or detects the voltage value Vb of each unit cell 11, and outputs the detection result to the controller 30. The current sensor 22 detects the current Ib flowing through the assembled battery 10 and outputs the detection result to the controller 30. In the present embodiment, when the battery pack 10 is discharged, a positive value is used as the current value (discharge current) Ib. Further, when charging the battery pack 10, a negative value is used as the current value (charging current) Ib.

  In the present embodiment, the current sensor 22 is provided on the positive line PL connected to the positive terminal of the battery pack 10. Here, the current sensor 22 only needs to be able to detect the current Ib flowing through the assembled battery 10, and the position where the current sensor 22 is provided can be set as appropriate. For example, the current sensor 22 can be provided on the negative electrode line NL connected to the negative electrode terminal of the assembled battery 10. A plurality of current sensors 22 can also be provided.

  The temperature sensor 23 detects the temperature Tb of the assembled battery 10 (unit cell 11) and outputs the detection result to the controller 30. When the temperature Tb varies depending on the position of the unit cell 11 included in the assembled battery 10, the temperature sensors 23 can be arranged at a plurality of locations in the assembled battery 10. Thereby, the temperature Tb of each cell 11 can be detected with high accuracy.

  The controller 30 has a memory 31 and a timer 32. The memory 31 stores various types of information for the controller 30 to perform predetermined processing (for example, processing described in the present embodiment). The timer 32 is used for time measurement. In the present embodiment, the memory 31 and the timer 32 are built in the controller 30, but at least one of the memory 31 and the timer 32 may be provided outside the controller 30.

  The outside air temperature sensor 41 detects the outside air temperature (outside air temperature) Tout outside the vehicle, and outputs the detection result to the controller 30. The illuminance sensor 42 detects the illuminance Ec outside the vehicle and outputs the detection result to the controller 30.

  A system main relay SMR-B is provided in the positive electrode line PL. System main relay SMR-B is switched between on and off by receiving a control signal from controller 30. A system main relay SMR-G is provided in the negative electrode line NL. System main relay SMR-G is switched between on and off by receiving a control signal from controller 30.

  A system main relay SMR-P and a current limiting resistor R are connected in parallel to the system main relay SMR-G. System main relay SMR-P and current limiting resistor R are connected in series. System main relay SMR-P is switched between on and off by receiving a control signal from controller 30.

  The current limiting resistor R is used for suppressing an inrush current from flowing through the capacitor C when the assembled battery 10 is connected to a load (specifically, an inverter 24 described later). Capacitor C is connected to positive electrode line PL and negative electrode line NL, and is used to smooth voltage fluctuations between positive electrode line PL and negative electrode line NL.

  When connecting the assembled battery 10 to the inverter 24, the controller 30 first switches the system main relay SMR-B from off to on and switches the system main relay SMR-P from off to on. Thereby, the discharge current of the assembled battery 10 can be passed through the current limiting resistor R, and the inrush current can be suppressed from flowing into the capacitor C.

  Next, the controller 30 switches the system main relay SMR-G from off to on and switches the system main relay SMR-P from on to off. Thereby, the connection between the assembled battery 10 and the inverter 24 is completed, and the battery system shown in FIG. 1 is in a start-up state (Ready-On). Information about on / off of the ignition switch of the vehicle is input to the controller 30, and the controller 30 activates the battery system shown in FIG. 1 in response to the ignition switch switching from off to on.

  On the other hand, when the ignition switch is switched from on to off, the controller 30 switches the system main relays SMR-B and SMR-G from on to off. Thereby, the connection between the assembled battery 10 and the inverter 24 is cut off, and the battery system shown in FIG. 1 enters a stopped state (Ready-Off).

  The inverter 24 converts the DC power output from the assembled battery 10 into AC power, and outputs the AC power to the motor generator (MG) 25. For example, a three-phase AC motor can be used as the motor / generator 25. The motor / generator 25 receives the AC power output from the inverter 24 and generates kinetic energy for running the vehicle. The kinetic energy generated by the motor / generator 25 is transmitted to the wheels so that the vehicle can run.

  When the vehicle is decelerated or stopped, the motor / generator 25 converts kinetic energy generated during braking of the vehicle into electric energy (AC power). The inverter 24 converts the AC power generated by the motor / generator 25 into DC power and outputs the DC power to the assembled battery 10. Thereby, the assembled battery 10 can store regenerative electric power.

  In the present embodiment, the assembled battery 10 is connected to the inverter 24, but the present invention is not limited to this. Specifically, a booster circuit can be provided in the current path between the assembled battery 10 and the inverter 24. The booster circuit can boost the output voltage of the battery pack 10 and output the boosted power to the inverter 24. Further, the booster circuit can step down the output voltage of the inverter 24 and output the lowered power to the assembled battery 10.

  In the battery system of this embodiment, when the ignition switch is on, the temperature sensor 23 can detect the temperature of the assembled battery 10 (unit cell 11). On the other hand, when the ignition switch is off, the temperature sensor 23 cannot detect the temperature of the assembled battery 10 (unit cell 11).

  Therefore, in the present embodiment, as described below, the temperature of the assembled battery 10 (unit cell 11) while the ignition switch is off is estimated. Here, the temperature of the assembled battery 10 (unit cell 11) while the ignition switch is off is referred to as a leaving temperature.

  In the present embodiment, the leaving temperature of the assembled battery 10 is estimated based on the outside air temperature in the region (environment) where the assembled battery 10 is used. Specifically, the use area of the assembled battery 10 is specified, and the leaving temperature of the assembled battery 10 is estimated based on the outside air temperature of the use area. The use region corresponds to the travel region of the vehicle on which the assembled battery 10 is mounted.

  In the present embodiment, in order to specify the use region of the assembled battery 10, first, the outside air temperature is detected while distinguishing day and night. Thereby, it is possible to detect the outside air temperature during the daytime and the outside air temperature during the night. Processing for detecting the outside air temperature during the day and night will be described with reference to the flowchart shown in FIG. The process shown in FIG. 2 is executed by the controller 30. Further, the process shown in FIG. 2 is repeated every time the predetermined period Δt elapses.

  In step S <b> 101, the controller 30 detects the illuminance Ec based on the output of the illuminance sensor 42, and detects the outside air temperature Tout based on the output of the outside air temperature sensor 41. In step S102, the controller 30 determines whether or not the illuminance Ec detected in the process of step S101 is greater than or equal to the threshold Eth. The threshold Eth is illuminance for distinguishing day and night and can be set as appropriate. Information regarding the threshold Eth can be stored in the memory 31.

  When the illuminance Ec is greater than or equal to the threshold Eth, the controller 30 performs the process of step S103. Further, when the illuminance Ec is lower than the threshold value Eth, the controller 30 performs the process of step S104. In step S103, the controller 30 increments the count value C. The count value C is a value used for determining day / night discrimination. Information regarding the count value C is stored in the memory 31.

  In step S104, the controller 30 determines whether the determination period Δt has elapsed. The determination period Δt is a period for performing determination of day and night, and can be set as appropriate. For example, the determination period Δt can be a period shorter than one day. Information regarding the determination period Δt can be stored in the memory 31. Specifically, the controller 30 uses the timer 32 to start measuring the time tm when starting the processing shown in FIG. Then, the controller 30 determines whether or not the measurement time tm has reached the determination period Δt.

  When the measurement time tm reaches the determination period Δt, the controller 30 performs the process of step S105. On the other hand, when the measurement time tm has not reached the determination period Δt, the controller 30 returns to the process of step S101. Thus, until the determination period Δt elapses, the detection of the illuminance Ec and the outside air temperature Tout is repeated, and the count value C increases every time the illuminance Ec is equal to or greater than the threshold Eth.

  In step S105, the controller 30 determines whether or not the count value C is greater than or equal to the threshold value Cth. The threshold value Cth is a value for confirming the discrimination between day and night, and can be set as appropriate. That is, when the count value C is equal to or greater than the threshold Cth, it is determined that it is daytime during the determination period Δt. On the other hand, when the count value C is smaller than the threshold value Cth, it is determined that it is night during the determination period Δt.

  Here, it is also conceivable to perform day / night discrimination based only on the illuminance Ec. For example, it can be determined that the day is when the illuminance Ec is equal to or greater than the threshold Eth, and can be determined as the night when the illuminance Ec is lower than the threshold Eth. However, in this case, it may be determined that day and night are mixed during the determination period Δt.

  For example, when the vehicle enters a tunnel even though the vehicle is traveling in the daytime, it may be determined that the night is due to a decrease in the illuminance Ec. In addition, even when the vehicle is traveling at night, when the vehicle is present under illumination equivalent to daytime illuminance, the illuminance Ec may increase, so that it may be determined as daytime. .

  In the case as described above, day and night are mixed during the determination period Δt, and the determination of day and night may be erroneously performed. Therefore, in this embodiment, the count value C is set, and when the count value C is equal to or greater than the threshold value Cth, it is determined that it is daytime.

  If the ratio at which the illuminance Ec equal to or higher than the threshold Eth is obtained during the determination period Δt is higher than the ratio at which the illuminance Ec lower than the illuminance Eth is obtained, the count value C tends to be equal to or higher than the threshold Cth. Accordingly, even when the illuminance Ec is temporarily reduced when the vehicle is traveling in the daytime, it is easy to determine that the period is the day during the determination period Δt.

  On the other hand, if the ratio at which the illuminance Ec lower than the threshold Eth is obtained during the determination period Δt is higher than the ratio at which the illuminance Ec equal to or higher than the illuminance Eth is obtained, the count value C is unlikely to exceed the threshold Cth. Thereby, even when the illuminance Ec temporarily increases when the vehicle is traveling at night, it is easy to determine that the period between the determination periods Δt is night.

  When the count value C is equal to or greater than the threshold value Cth, the controller 30 determines that the determination period Δt is daytime in step S106. On the other hand, when the count value C is smaller than the threshold value Cth, the controller 30 determines in step S108 that the determination period Δt is night.

  In step S107, the controller 30 stores the outside temperature Tout detected during the determination period Δt in the memory 31 as the daytime outside temperature. In step S109, the controller 30 stores the outside air temperature Tout detected during the determination period Δt in the memory 31 as the outside air temperature at night.

  FIG. 3 shows behaviors (an example) of the illuminance Ec, the count value C, and the outside air temperature Tout when the processing shown in FIG. 2 is performed. In FIG. 3, the vertical axis represents the illuminance Ec, the count value C, and the outside air temperature Tout. Also, the horizontal axis in FIG. 3 indicates time.

  As shown in FIG. 3, when the illuminance Ec is equal to or greater than the threshold value Eth, the count value C continues to increase. When the illuminance Ec is lower than the threshold Eth, the count value C does not increase, and is maintained at the count value C before the illuminance Ec becomes lower than the threshold Eth. In the example illustrated in FIG. 3, it is determined that the day is during the determination period Δt. The outside air temperature Tout during the determination period Δt is stored in the memory 31 as the daytime outside air temperature Tout.

  On the other hand, in the example shown in FIG. 4, the illuminance Ec temporarily exceeds the threshold Eth, but the count value C does not reach the threshold Cth, so that the determination period Δt is determined to be nighttime. The outside air temperature Tout during the determination period Δt is stored in the memory 31 as the outside air temperature Tout at night.

  Next, the process for specifying the use region of the assembled battery 10 will be described with reference to the flowchart shown in FIG. The process shown in FIG. 5 is executed by the controller 30, and after the process shown in FIG. 2 is performed, the process shown in FIG. 5 is performed.

  In step S201, the controller 30 specifies the maximum temperature Tmax within a predetermined period. The predetermined period (corresponding to the first period in the present invention) is a period longer than the determination period Δt described in the process shown in FIG. 2, and the predetermined period includes a plurality of determination periods Δt. The predetermined period can be set as appropriate, for example, one month. Information relating to the predetermined period can be stored in the memory 31.

  The maximum temperature Tmax indicates the highest outside temperature Tout in the change of the outside temperature Tout within a predetermined period. With the process shown in FIG. 2, it is possible to acquire a change in the outside air temperature Tout during the determination period Δt. Therefore, the maximum temperature Tmax can be specified based on the change in the outside temperature Tout.

  In step S202, the controller 30 specifies the minimum temperature Tmin within a predetermined period. The predetermined period here is the same as the predetermined period described in the process of step S201. The minimum temperature Tmin indicates the lowest outside temperature Tout in the change of the outside temperature Tout within a predetermined period. With the process shown in FIG. 2, it is possible to acquire a change in the outside air temperature Tout during the determination period Δt. Therefore, the minimum temperature Tmin can be specified based on the change in the outside temperature Tout.

  In step S203, the controller 30 calculates an average temperature Tout_ave_d of the daytime outside temperature Tout within a predetermined period. The predetermined period here is also the same as the predetermined period described in step S201. According to the process shown in FIG. 2, it is possible to acquire the outside air temperature Tout when the determination period Δt is daytime. Therefore, the average temperature Tout_ave_d can be obtained by calculating the average value of the outside temperature Tout in the determination period Δt included in the predetermined period and determined to be daytime.

  In step S204, the controller 30 calculates an average temperature Tout_ave_n of the nighttime outside temperature Tout within a predetermined period. The predetermined period here is also the same as the predetermined period described in step S201. According to the process shown in FIG. 2, it is possible to acquire the outside air temperature Tout when the determination period Δt is nighttime. Therefore, the average temperature Tout_ave_n can be obtained by calculating the average value of the outside temperature Tout in the determination period Δt included in the predetermined period and determined to be nighttime.

  In step S205, the controller 30 calculates an average temperature Tout_ave_all of the outside temperature Tout within a predetermined period. The predetermined period here is also the same as the predetermined period described in step S201. The average temperature Tout_ave_all is an average value of the outside temperature Tout within a predetermined period regardless of day or night.

  In the present embodiment, since the average temperatures Tout_ave_d and Tout_ave_n are calculated by the processes of steps S203 and 204, the average temperature Tout_ave_all is calculated using the average temperatures Tout_ave_d and Tout_ave_n. Specifically, the average temperature Tout_ave_all is calculated based on the following formula (1).

  In the above equation (1), α is a coefficient related to the average temperature Tout_ave_d, and β is a coefficient related to the average temperature Tout_ave_n. The coefficients α and β can be set in advance. Information regarding the coefficients α and β can be stored in the memory 31.

  For example, if the average temperature Tout_ave_d indicates a value along the actual measurement value (daytime average temperature) and the average temperature Tout_ave_n indicates a value along the actual measurement value (nighttime average temperature), the coefficients α and β are set to “0. 5 ". Thereby, the value along the actual measurement value can be obtained as the average temperature Tout_ave_all. The coefficients α and β can be set as appropriate.

  In step S206, the controller 30 calculates the annual average temperature Tout_ave_y. One year (corresponding to the second period in the present invention) can be divided into a plurality of predetermined periods. Therefore, if the average temperature Tout_ave_all is calculated in each of a plurality of predetermined periods included in one year, the annual average temperature Tout_ave_y can be calculated. Specifically, the annual average temperature Tout_ave_y can be calculated based on the following formula (2).

  In the above formula (2), ΣTout_ave_all is a value obtained by summing the average temperatures Tout_ave_all in a plurality of predetermined periods included in one year. N is the number of predetermined periods included in one year. For example, when the predetermined period is set to one month, N is “12”.

  In step S207, the controller 30 specifies the usage region of the assembled battery 10 based on the temperature Tmax, Tmin, Tout_ave_all, Tout_ave_y. Depending on the region, at least one of the temperatures Tmax, Tmin, Tout_ave_all, and Tout_ave_y may be different. For example, when comparing an extremely hot area, a cold area, and an area that does not belong to an extremely hot area or a cold area, the temperatures Tmax, Tmin, Tout_ave_all, and Tout_ave_y tend to be different.

  Therefore, if the temperatures Tmax, Tmin, Tout_ave_all, Tout_ave_y are measured in advance for each region, the usage region of the assembled battery 10 is determined based on the temperatures Tmax, Tmin, Tout_ave_all, Tout_ave_y obtained by the processing shown in FIG. Can be identified.

  Specifically, for a plurality of regions, correspondence relationships between the regions and temperatures Tmax, Tmin, Tout_ave_all, Tout_ave_y can be obtained in advance, and information on the correspondence relationships can be stored in the memory 31. And if this correspondence is used, the area | region corresponding to temperature Tmax, Tmin, Tout_ave_all, Tout_ave_y obtained by the process shown in FIG. 5 can be specified. The area specified in this way becomes the use area of the assembled battery 10.

  As described above, when specifying an area, the temperatures Tmax, Tmin, Tout_ave_all, Tout_ave_y obtained by the processing shown in FIG. 5 do not have to match the temperatures Tmax, Tmin, Tout_ave_all, Tout_ave_y stored in the memory 31. . Specifically, when the temperatures Tmax, Tmin, Tout_ave_all, and Tout_ave_y are compared, the temperature Tmax, Tmin, Tout_ave_all, and Tout_ave_y with the least deviation can be specified to specify the usage region of the assembled battery 10. .

  In this embodiment, the use region of the battery pack 10 is specified in consideration of the temperatures Tmax, Tmin, Tout_ave_all, and Tout_ave_y, but the present invention is not limited to this. Specifically, the use region of the assembled battery 10 can be specified in consideration of at least one of the temperatures Tmax, Tmin, Tout_ave_all, and Tout_ave_y. However, as the temperature information (temperature Tmax, Tmin, Tout_ave_all, Tout_ave_y) for specifying the region increases, it becomes easier to specify the usage region of the assembled battery 10.

  In this embodiment, the annual average temperature Tout_ave_y is calculated, but the present invention is not limited to this. That is, the average temperature during a period longer than the predetermined period may be calculated using the average temperature Tout_ave_all for a plurality of predetermined periods. Here, if the use area of the assembled battery 10 is not changed, a change in the outside air temperature Tout with a cycle of one year tends to exhibit the same behavior. Therefore, as in this embodiment, calculating the annual average temperature Tout_ave_y makes it easy to specify the area where the assembled battery 10 is used.

  Next, the process of estimating the leaving temperature of the assembled battery 10 will be described using the flowchart shown in FIG. The process illustrated in FIG. 6 is performed by the controller 30 and is performed after the process illustrated in FIG. 5 is performed.

  In step S301, the controller 30 specifies the annual average temperature Tout_ave_y in the area where the assembled battery 10 is used. By performing the process shown in FIG. 5, it is possible to specify the usage region of the assembled battery 10. Here, in the process of step S207 shown in FIG. 5, the correspondence relationship between the region and the annual average temperature Tout_ave_y is used, and also in the process of step S301, the annual average temperature Tout_ave_y is specified.

  Specifically, since the use region of the assembled battery 10 is specified by the process shown in FIG. 5, the annual average temperature Tout_ave_y corresponding to the specified use region is obtained by using the correspondence relationship between the region and the annual average temperature Tout_ave_y. Can be identified. In the process of step S301, the annual average temperature Tout_ave_y calculated by the process of step S206 shown in FIG. 5 can also be used.

  In step S <b> 302, the controller 30 estimates the leaving temperature Tb_rest of the assembled battery 10. For example, when it is assumed that the temperature Tb of the battery pack 10 is equal to the outside air temperature Tout when the ignition switch is off, the annual average temperature Tout_ave_y specified in step S301 can be used as the leaving temperature Tb_rest.

  On the other hand, when it is assumed that the room temperature of the vehicle is higher than the outside air temperature Tout, it can be assumed that the temperature Tb of the assembled battery 10 mounted on the vehicle is also higher than the outside air temperature Tout. In this case, a temperature higher than the annual average temperature Tout_ave_y can be used as the leaving temperature Tb_rest.

  Specifically, the temperature rise amount ΔT can be obtained in advance by experiments or the like. This temperature increase amount ΔT corresponds to the difference between the room temperature of the vehicle and the outside temperature Tout. Here, the temperature obtained by adding the temperature increase ΔT to the annual average temperature Tout_ave_y can be set as the leaving temperature Tb_rest.

  FIG. 7 shows the behavior of the temperature Tb and the outside air temperature Tout of the assembled battery 10. In FIG. 7, the vertical axis represents temperature, and the horizontal axis represents time. In FIG. 7, when the ignition switch is on, the temperature Tb of the battery pack 10 (unit cell 11) can be detected using the temperature sensor 23. On the other hand, when the ignition switch is off, the temperature sensor 23 is not used to detect the temperature Tb of the assembled battery 10 (unit cell 11).

  In FIG. 7, the dotted line indicates the annual average temperature Tout_ave_y, and a temperature that is higher than the annual average temperature Tout_ave_y by the temperature increase amount ΔT is the leaving temperature Tb_rest of the assembled battery 10. As shown in FIG. 7, the actual outside air temperature Tout is higher than the annual average temperature Tout_ave_y or lower than the annual average temperature Tout_ave_y.

  As will be described later, in this embodiment, the deterioration amount of the assembled battery 10 is estimated based on the leaving temperature Tb_rest of the assembled battery 10. Normally, the deterioration of the assembled battery 10 does not progress in a short time, but the deterioration of the assembled battery 10 progresses over a long period of time. Therefore, in order to estimate the deterioration amount of the assembled battery 10, when specifying the leaving temperature Tb_rest, it is not necessary to consider the outside air temperature Tout that changes with time, and it is sufficient to consider the average value of the outside air temperature Tout. . Therefore, in this embodiment, when estimating the deterioration amount of the assembled battery 10, one year is set as a reference, and the leaving temperature Tb_rest of the assembled battery 10 is estimated based on the annual average temperature Tout_ave_y.

  In the present embodiment, the leaving temperature Tb_rest is estimated based on the annual average temperature Tout_ave_y, but is not limited thereto. For example, the neglected temperature Tb_rest can be estimated based on the average temperature Tout_ave_all within a predetermined period calculated by the process of step S205 shown in FIG. In this case, the average temperature Tout_ave_all within a predetermined period can be set as the leaving temperature Tb_rest, or the temperature obtained by adding the temperature increase ΔT to the average temperature Tout_ave_all can be set as the leaving temperature Tb_rest.

  Here, since the predetermined period is a period shorter than one year, the average temperature Tout_ave_all may change depending on the time. In this case, for example, when the user inputs the current time, a predetermined period corresponding to the current time can be specified, and the average temperature Tout_ave_all in this predetermined period can be specified.

  In this embodiment, the day / night discrimination is performed based on the illuminance Ec detected by the illuminance sensor 42, but the present invention is not limited to this. Specifically, in a vehicle equipped with a radio timepiece, day / night discrimination can be performed based on time information of the radio timepiece. A radio timepiece is a timepiece having a function of receiving a standard radio wave and automatically correcting an error. Here, if the day time zone and the night time zone are set in advance, the day / night discrimination can be performed by specifying the time zone to which the current time acquired from the radio clock belongs.

  In the present embodiment, the annual average temperature Tout_ave_y is calculated in the process shown in FIG. 5, but the yearly average temperature Tout_ave_y cannot be calculated unless one year has passed since the detection of the outside temperature Tout. . Therefore, while the annual average temperature Tout_ave_y cannot be calculated, a preset temperature can be used as the annual average temperature Tout_ave_y in the usage region. This temperature setting can be performed as appropriate, and information regarding the preset annual average temperature Tout_ave_y can be stored in the memory 31.

  After calculating the annual average temperature Tout_ave_y by the process shown in FIG. 5, the preset annual average temperature Tout_ave_y can be changed to the calculated annual average temperature Tout_ave_y. Then, information regarding the annual average temperature Tout_ave_y after the change can be stored in the memory 31.

  Further, when the neglected temperature Tb_rest is estimated based on the annual average temperature Tout_ave_y calculated in the process of step S206 shown in FIG. 5, each time the annual average temperature Tout_ave_y is calculated by the process of step S206, it is stored in the memory 31. The annual average temperature Tout_ave_y can be updated.

  When the leaving temperature Tb_rest of the assembled battery 10 is estimated as in the present embodiment, the deterioration amount of the assembled battery 10 can be estimated based on the standing temperature Tb_rest. Moreover, the input / output (charging / discharging) of the assembled battery 10 can be controlled based on the estimated deterioration amount.

  A process for controlling the input / output of the battery pack 10 based on the deterioration amount will be described with reference to the flowchart shown in FIG. The process shown in FIG. 8 is executed by the controller 30.

  In step S401, the controller 30 calculates the deterioration rate DR_on of the assembled battery 10 when the ignition switch is on. The deterioration rate DR_on is an increase amount of the deterioration amount per unit time. Since the deterioration of the assembled battery 10 depends on the temperature Tb of the assembled battery 10, the deterioration rate DR_on can be calculated based on the battery temperature Tb.

  Specifically, if the correspondence relationship between the battery temperature Tb and the deterioration rate DR_on is obtained in advance, the deterioration rate DR_on corresponding to the battery temperature Tb can be specified by detecting the battery temperature Tb. Here, regarding the correspondence between the battery temperature Tb and the deterioration rate DR_on, the deterioration rate DR_on can be increased as the battery temperature Tb increases.

  On the other hand, the deterioration of the assembled battery 10 also depends on the SOC (State of Charge) of the assembled battery 10. The SOC is the ratio of the current charge capacity to the full charge capacity. For this reason, if the correspondence relationship between the deterioration rate DR_on and the SOC is obtained in advance, the deterioration rate DR_on corresponding to this SOC can be specified by estimating the SOC of the battery pack 10. As a method for estimating the SOC, a known method can be appropriately used. For example, the SOC of the assembled battery 10 can be estimated by continuing to accumulate current values when the assembled battery 10 is charged and discharged.

  The deterioration rate DR_on can also be calculated based on the temperature Tb and SOC of the battery pack 10. Specifically, as shown in FIG. 9, if the correspondence relationship between the deterioration rate DR_on, the battery temperature Tb, and the SOC is obtained in advance, the deterioration rate DR_on can be calculated using this correspondence relationship. In FIG. 9, the vertical axis indicates the deterioration rate DR_on, and the horizontal axis indicates the SOC.

  Curves k1, k2, and k3 shown in FIG. 9 indicate the correspondence between the deterioration rate DR_on and the SOC. As indicated by the curves k1, k2, and k3, the deterioration rate DR_on increases as the SOC of the battery pack 10 increases. In other words, the deterioration rate DR_on decreases as the SOC of the battery pack 10 decreases.

  In curves k1, k2, and k3, battery temperatures Tb are different from each other. The battery temperature Tb1 that defines the curve k1 is higher than the battery temperature Tb2 that defines the curve k2. Further, the battery temperature Tb2 is higher than the battery temperature Tb3 that defines the curve k3. Thus, the deterioration rate DR_on increases as the battery temperature Tb increases. In other words, the deterioration rate DR_on decreases as the battery temperature Tb decreases.

  In step S402, the controller 30 calculates the deterioration rate DR_off of the assembled battery 10 when the ignition switch is off. Similar to the deterioration rate DR_on, the deterioration rate DR_off can be calculated based on at least one of the temperature Tb and the SOC of the battery pack 10. When the deterioration rate DR_off is calculated in consideration of the battery temperature Tb, the leaving temperature Tb_rest estimated by the process shown in FIG. 6 is used as the battery temperature Tb.

  In step S <b> 403, the controller 30 calculates the current deterioration amount DE in the assembled battery 10. Specifically, the deterioration amount DE_on can be calculated by integrating the deterioration rate DR_on calculated in the process of step S401 during a period in which the ignition switch is on.

  Further, the deterioration amount DE_off can be calculated by integrating the deterioration rate DR_off calculated in the process of step S402 in a period in which the ignition switch is off. The current deterioration amount DE can be calculated by adding the deterioration amounts DE_on and DE_off.

  In the present embodiment, by calculating not only the deterioration amount DE_on but also the deterioration amount DE_off, it is possible to improve the estimation accuracy of the current deterioration amount DE. In general, the time during which the ignition switch is off is longer than the time during which the ignition switch is on. For this reason, the battery temperature Tb (leaving temperature Tb_rest) when the ignition switch is off has a great influence on the deterioration of the assembled battery 10. Therefore, as in this embodiment, by calculating not only the deterioration amount DE_on but also the deterioration amount DE_off, the current deterioration amount DE can be accurately estimated.

  In step S404, the controller 30 determines whether or not the deterioration amount DE calculated in the process of step S403 is greater than or equal to the threshold value DE_th. The threshold value DE_th is a value for determining whether or not to limit the input / output of the battery pack 10, and can be set as appropriate.

  Here, as the threshold value DE_th is decreased, the input / output of the battery pack 10 is more likely to be limited, as will be described later. If the input / output is easily restricted, the drivability of the vehicle may be adversely affected. On the other hand, as the threshold value DE_th is increased, the input / output of the battery pack 10 is less likely to be restricted as will be described later. If the input / output becomes difficult to be restricted, the battery pack 10 may be deteriorated.

  The threshold DE_th can be set in consideration of the above points, and information regarding the threshold DE_th can be stored in the memory 31. When the deterioration amount DE is equal to or greater than the threshold value DE_th, the controller 30 limits the input / output of the assembled battery 10 in step S405. On the other hand, when the deterioration amount DE is smaller than the threshold value DE_th, the controller 30 does not limit the input / output of the assembled battery 10 in step S406.

  When controlling the input / output of the battery pack 10, an upper limit power that allows input (charging) and an upper limit power that allows output (discharging) are set. Here, each upper limit electric power regarding input / output is set in advance, and for example, the upper limit electric power can be changed according to the temperature Tb and SOC of the assembled battery 10. In the process of step S405, when the input / output is limited, the preset upper limit power is reduced. In the process of step S406, when input / output is not limited, a preset value is used as the upper limit power corresponding to input / output.

10: assembled battery (power storage device), 11: single cell, 21: monitoring unit, 22: current sensor,
23: Temperature sensor, 24: Inverter, 25: Motor generator
30: Controller, 31: Timer, 32: Memory, 41: Outside air temperature sensor,
42: Illuminance sensor, PL: positive line, NL: negative line,
SMR-B, SMR-G, SMR-P: System main relay,
R: current limiting resistor, C: capacitor

Claims (9)

A power storage device mounted on the vehicle;
An outside air temperature sensor for detecting outside air temperature outside the vehicle;
A controller for estimating a storage temperature of the power storage device when an ignition switch of the vehicle is off,
The controller is
When the ignition switch is on, the outside air temperature sensor is used to detect the outside air temperature while distinguishing the time zone of the day,
Using the detected outside temperature , the highest temperature, the lowest temperature and the average temperature in the first period, and the average temperature in the second period longer than the first period,
An area showing the temperature along these calculated temperatures is identified as the travel area of the vehicle,
The power storage system characterized in that the neglected temperature is estimated based on an outside air temperature set in advance for the identified travel area . 2. The power storage system according to claim 1 , wherein the controller estimates a temperature higher than the specified outside air temperature of the travel region as the neglected temperature. The power storage system according to claim 1 , wherein the controller estimates an outside temperature of the identified travel area as the neglected temperature. Wherein the controller, the as the outside temperature as a reference when estimating the standing temperature, power storage according to any one of claims 1 to 3, which comprises using the annual average temperature of the identified said travel region was system. The controller is
Until the average temperature in the second period is calculated, the outside temperature preset as the average temperature in the second period is used ,
When the average temperature in the second period is calculated , the standing temperature is estimated using the average temperature .
The power storage system according to any one of claims 1 to 4 , wherein: It has an illuminance sensor that detects illuminance outside the vehicle,
The power storage system according to any one of claims 1 to 5 , wherein the controller distinguishes day and night as the time zone by using the illuminance detected by the illuminance sensor. The controller is
When the illuminance detected by the illuminance sensor is greater than or equal to a threshold value related to illuminance, the count value is incremented,
Said count value, day and determine when the at count value threshold above regarding the count value, according to claim 6, characterized in that to determine the night when the smaller than the threshold for the count value Power storage system. It has a radio clock that identifies the current time using standard radio waves,
The power storage system according to any one of claims 1 to 5 , wherein the controller distinguishes the time zone using a time of the radio timepiece. Said controller using said correspondence between the deteriorated state of the power storage device and the left temperature, any one of claims 1 to 8, characterized in that to calculate the deterioration state corresponding to the estimated the left temperature The power storage system described in 1.