JP2016005304A - vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a detection value of a temperature sensor in consideration of an influence of external air introduced through a duct communicated with the outside of a vehicle, thus appropriately protecting a power storage device.SOLUTION: A vehicle, provided with a power storage stack constituted by plural power storage elements and incorporated with a power storage pack housing the power storage stack inside a case, further includes a duct communicating between inside of the case and outside the vehicle. A controller performs: controlling charging and discharging of the power storage stack, and input and output of power of the power storage stack with an upper limit value of the input-output power limited; detecting variation in detection values of a temperature sensor due to an influence of external temperature via the duct on the basis of information of temperature difference in the external temperature, the detection value of the temperature sensor and current information, and correcting the detection value of the temperature sensor; and controlling input and output using the corrected detection value of the temperature sensor, and correcting the detection value of the temperature sensor by increasing a correction amount to the detection value of the temperature sensor proportionately as the temperature difference increases, or decreasing the correction amount proportionately as a current volume increases.

Description

  The present invention relates to temperature detection of a power storage device including a smoke exhaust duct that discharges gas generated from the power storage device to the outside of the vehicle in which the power storage device is mounted, and protection of the power storage device based on the temperature detection.

  The power storage device of Patent Document 1 includes a battery stack, a storage case that stores the battery stack, and a smoke exhaust duct provided in the storage case. The battery stack includes a plurality of single cells, and a smoke exhaust duct is connected to the outside of the vehicle. At this time, the battery stack is provided with a temperature sensor for measuring the temperature.

JP 2012-227120 A

  The smoke exhaust duct communicates with the outside of the vehicle. When the user of the vehicle opens the window and the air in the passenger compartment exits from the window, the air flows into the battery from the smoke exhaust duct. As a result, outside air may flow into the housing case, and the temperature sensor may not be able to measure the accurate battery temperature of the battery stack.

  On the other hand, for example, if charging / discharging is performed at a high battery temperature, battery deterioration is likely to be promoted. If charging is performed at a low battery temperature, overvoltage or high-rate deterioration occurs due to an increase in internal resistance. Deteriorates. For this reason, although it is necessary to control charging / discharging of a battery stack according to battery temperature, if the battery temperature of a battery stack cannot be measured correctly, a battery stack cannot be protected appropriately.

  Therefore, the present invention provides a vehicle that can appropriately protect a power storage device by correcting the detection value of a temperature sensor that detects the temperature of the power storage device in consideration of the influence of outside air flowing in from a duct communicating with the outside of the vehicle. Objective.

  The present invention is a vehicle including a power storage stack including a plurality of power storage elements and mounting a power storage pack in which the power storage stack is housed. The vehicle includes a duct that communicates the inside of the case with the outside of the vehicle, a temperature sensor that measures the temperature of the electricity storage stack, an outside air temperature sensor that measures the outside air temperature outside the vehicle, a current sensor that measures the current flowing through the electricity storage stack, And a controller for controlling input / output of the stack and controlling input / output power of the power storage stack while controlling charge / discharge of the stack.

  The controller detects the temperature sensor detection value due to the influence of the outside air temperature via the duct based on the temperature difference information that is the temperature sensor detection value and the temperature difference between the outside air temperatures and the current information that is the amount of current flowing through the power storage device. , And the detection value of the temperature sensor is corrected based on the temperature difference information and the current information in accordance with detection of the detection value fluctuation. Then, input / output control is performed using the corrected detection value of the temperature sensor.

  Further, when the controller performs input / output control using the corrected detection value of the temperature sensor, the correction amount with respect to the detection value of the temperature sensor increases as the temperature difference increases, and the correction amount increases as the current amount increases. It is possible to correct the detection value of the temperature sensor by reducing the value.

  According to the present invention, it is determined whether or not the fluctuation of the detection value of the temperature sensor is due to the influence of the outside air temperature, and the detection value of the temperature sensor is calculated based on the temperature difference between the detection value of the temperature sensor and the outside air temperature. to correct. For this reason, even if measurement deviation of the temperature sensor caused by the influence of the outside air temperature occurs, input / output control (protection processing) for protecting the power storage stack can be performed in accordance with the fluctuation of the detection value caused by the influence of the outside air temperature. . Then, it is only necessary to correct the detection value of the temperature sensor each time according to the temperature fluctuation of the power storage stack due to the influence of the outside air temperature, and it is not necessary to limit the input / output power of the power storage stack in advance in anticipation of the measurement deviation. Therefore, fuel consumption deterioration can be suppressed.

  In addition, the correction to the temperature sensor detection value increases the correction amount as the temperature difference increases, and the correction amount decreases as the current amount increases, so if the factor due to the outside temperature is large, the detection value of the temperature sensor When the factor due to the heat generation of the electricity storage stack itself based on the amount of current is large, the fluctuation of the detected value due to the influence of the outside temperature is estimated to be low, and the electricity storage stack is charged / discharged. Therefore, the storage stack can be protected in consideration of the temperature fluctuations.

It is a figure which shows the structure of the battery system mounted in a vehicle. It is a figure which shows the structure of the battery pack mounted in the vehicle interior. It is a figure which shows the relationship between the change of the detected value of the temperature sensor by the external air inflow to a battery pack through a smoke exhaust duct, and the change of an electric current value (battery temperature <external temperature). It is a flowchart which shows the battery high temperature abnormality determination process of a battery system. It is a figure which shows an example of the map (map A) which calculates the determination threshold value DT_htmp_pth (> 0) of the temperature rise by external air inflow. It is a figure which shows an example of the calculation map (map B) of the temperature offset amount (> 0) according to the temperature difference and the emitted-heat amount (electric current value) of external temperature and battery temperature. It is a figure which shows an example of the map (map C) which calculates determination threshold value DT_htmp_mth of temperature fall. It is a figure which shows the relationship between the change of the detected value of the temperature sensor by the external air inflow to a battery pack through a smoke exhaust duct, and the change of an electric current value (battery temperature> external temperature). It is a flowchart which shows the setting process of the allowable input power (Win) of a battery system. It is a figure which shows an example of the map (map A1) which calculates the determination threshold value DT_dep_mth (<0) of the temperature fall by external air inflow. It is a figure which shows an example of the calculation map (map B1) of the temperature offset amount (<0) according to the temperature difference and the emitted-heat amount (electric current value) of external temperature and battery temperature. It is a figure which shows an example of the map (map C1) which calculates determination threshold value DT_dep_pth of a temperature rise.

  Examples of the present invention will be described below.

  FIG. 1 is a diagram showing the configuration of the battery system of this example. The battery system shown in FIG. 1 can be mounted on a vehicle, for example. Examples of vehicles include HV (Hybrid Vehicle), PHV (Plug-in Hybrid Vehicle), and EV (Electric Vehicle).

  The assembled battery (corresponding to a power storage stack) 1 has a plurality of unit cells (corresponding to power storage elements) 2 connected in series. As the unit cell 2, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor can be used instead of the secondary battery.

  The number of the single cells 2 can be appropriately set based on the required output of the assembled battery 1 and the like. In the assembled battery 1 of the present embodiment, all the single cells 2 are connected in series, but the assembled battery 1 may include a plurality of single cells 2 connected in parallel.

  The monitoring unit 20 detects the voltage between the terminals of the assembled battery 1 or detects the voltage between the terminals of each unit cell 2 and outputs the detection result to the controller 30. The current sensor 21 detects a current flowing through the assembled battery 1 and outputs a detection result to the controller 30. The temperature sensor 22 detects the battery temperature TB of the assembled battery 1 (unit cell 2) and outputs the detection result to the controller 30.

  The assembled battery 1 is connected to the inverter 23 via the positive electrode line PL and the negative electrode line NL. System main relays SMR-B and SMR-G are provided on the positive line PL and the negative line NL, respectively. System main relays SMR-B and SMR-G are switched between on and off in response to a control signal from controller 30.

  The inverter 23 converts the DC power output from the assembled battery 1 into AC power, and outputs the AC power to the motor / generator 24. For example, a three-phase AC motor can be used as the motor / generator 24. The motor / generator 24 receives the AC power output from the inverter 23 and generates kinetic energy for running the vehicle. The vehicle can be driven by transmitting the kinetic energy generated by the motor / generator 24 to the wheels.

  When the vehicle is decelerated or stopped, the motor generator 24 converts kinetic energy generated during braking of the vehicle into electric energy (AC power). The inverter 23 converts the AC power generated by the motor / generator 24 into DC power and outputs the DC power to the assembled battery 1. Thereby, the assembled battery 1 can store regenerative electric power.

  The assembled battery 1 and the inverter 23 may be connected via a booster circuit. By using a booster circuit, the output voltage of the assembled battery 1 can be boosted. Further, the booster circuit can step down the output voltage from the inverter 23 to the assembled battery 1.

  The controller 30 includes a memory 31, and the memory 31 stores various types of information for the controller 30 to perform predetermined processing (for example, processing described in the present embodiment). In this embodiment, the memory 31 is built in the controller 30, but the memory 31 may be provided outside the controller 30.

  A detection result from the outside air temperature sensor 25 is output to the controller 30. The outside air temperature sensor 25 can be composed of, for example, one or a plurality of temperature sensors, and measures the outside air temperature (outside air temperature T_out).

  The controller 30 connects the assembled battery 1 and the inverter 23 by switching the system main relays SMR-B and SMR-G from off to on, and the battery system shown in FIG. 1 is in the activated state (Ready-On). Become. Information on on / off of the ignition switch of the vehicle (IG-ON / IG-OFF) is input to the controller 30, and the controller 30 activates the battery system 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 1 and the inverter 23 is cut off, and the battery system is in a stopped state (Ready-Off).

  FIG. 2 is a diagram illustrating a configuration of a battery pack mounted in the vehicle interior. In the example of FIG. 2, the FR direction indicates the forward direction of the vehicle 100, and the RH direction indicates the left-right direction of the vehicle 100 orthogonal to the FR direction. The assembled battery 1 is accommodated in the case C and constitutes a battery pack 10 (corresponding to a power storage pack). The battery pack 10 can be mounted, for example, under a seat (front seat or rear seat) 101 disposed in the passenger compartment of the vehicle 100.

  A blower 4 is connected to the case C that houses the assembled battery 1, and an intake duct 3 is connected to the upstream side of the blower 4. An end of the intake duct 3 is connected to an intake port 3a facing the vehicle interior. The assembled battery 1 is cooled by the air in the vehicle compartment taken into the case C. The exhaust duct 5 is connected to the opposite case C to which the intake duct 3 is connected. The air in the vehicle compartment that has flowed into the battery pack 10 through the intake duct 3 exchanges heat with the assembled battery 10, and is exhausted from the exhaust port 5 a into the vehicle compartment through the exhaust duct 5.

  The plurality of unit cells 2 constituting the assembled battery 1 can be arranged side by side in the RH direction, for example, as shown in FIG. The unit cell 2 can be provided with a discharge valve for discharging the gas generated inside the unit cell 2 to the outside. As is well known, the unit cell 2 can have a power generation element that charges and discharges and a battery case that houses the power generation element. The power generation element includes a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate. The separator is infiltrated with the electrolyte. Further, in the battery case, an electrolyte is present as a surplus liquid around the power generation element.

  The discharge valve is for discharging a gas such as an electrolyte vaporized by the temperature rise of the power generation element accompanying charging / discharging to the outside of the unit cell 2. For example, the internal gas can be discharged to the outside of the unit cell 2 by breaking the discharge valve with respect to the internal pressure that increases due to the generation of gas.

  In the example of FIG. 2, a discharge valve can be provided on the upper surface of the unit cell 2, and a smoke exhaust path S extending in the RH direction is provided inside the battery pack 10 corresponding to the discharge valve of each of the plurality of unit cells 2. Can be provided. The smoke exhaust path S is an isolated path so that gas does not flow from the battery pack 10 into the vehicle interior. The smoke exhaust path S is connected to a smoke exhaust duct 6 communicating with the outside of the vehicle. One end side of the smoke exhaust duct 6 is connected to the smoke exhaust path S of the battery pack 10, and the other end side is connected to the outside of the vehicle (outside the passenger compartment).

  And the temperature sensor 22 can also be provided in several different places among the assembled batteries 1. FIG. In the example of FIG. 2, three batteries are provided at the central portion and the end portion in the longitudinal direction (RH direction) of the assembled battery 1. When using the detection temperatures of the plurality of temperature sensors 22, as the temperature of the assembled battery 1, a minimum value, a maximum value, or a median value or an average value of the plurality of detection temperatures among the plurality of detection temperatures can be appropriately used. Note that the temperature sensor 22 may be provided at one location of the assembled battery 1.

  Furthermore, a plurality of temperature sensors 22 can be provided in the smoke exhaust path S. It is also possible to provide not adjacent to the smoke exhaust path S but adjacent to the outside of the smoke exhaust path S (for example, so as to be in contact with the outside of the smoke exhaust path S).

  The gas discharged from the unit cell 2 (the assembled battery 1) is exhausted to the outside of the vehicle through the smoke exhaust duct 6 and does not flow into the vehicle interior from the battery pack 10, but the smoke exhaust duct 6 communicates with the outside of the vehicle. doing. For this reason, as shown in FIG. 3, when the user of the vehicle 100 opens the window and the air in the passenger compartment comes out from the window, the battery pack 10 (smoke exhaust path S) is discharged from the smoke exhaust duct 6 accordingly. Air flows in. In FIG. 3, the solid line is the detection value of the temperature sensor 22, and the two-dot chain line is the actual battery temperature TB during the window opening period.

  When the temperature sensor 22 provided in the smoke exhaust path S is affected by outside air flowing in from the smoke exhaust duct 6, a “temperature measurement deviation” occurs. For example, even if the actual battery temperature TB is smaller than the outside air temperature T_out, the detection value of the temperature sensor 22 rises rapidly due to the influence of the outside air temperature T_out, and the actual battery temperature TB of the assembled battery 1 cannot be measured. . The same applies when the temperature sensor 22 is provided adjacent to the smoke exhaust path S.

  For this reason, it is necessary to limit the upper and lower limit power of the input / output of the assembled battery 1 in accordance with the battery temperature TB in consideration of the deterioration of the assembled battery 1, but a “temperature measurement deviation” occurs due to the influence of the outside air temperature T_out. Since the battery temperature TB of the assembled battery 1 cannot be measured accurately, the input / output limitation of the assembled battery 1 according to the battery temperature TB, that is, the high temperature abnormality detection of the assembled battery 1 cannot be performed.

  Further, if the upper and lower limit power of the assembled battery 1 is limited to be low in advance in anticipation of the “temperature measurement deviation” caused by the influence of the outside air temperature T_out, the fuel consumption is deteriorated.

  Therefore, in this embodiment, when the detection value of the temperature sensor 22 provided in the smoke exhaust path S communicating with the outside of the vehicle fluctuates, it is determined whether or not the influence is due to the outside air temperature, and the temperature is influenced by the outside air temperature. When it is determined that the detection value of the sensor 22 has fluctuated, the detection value of the temperature sensor 22 that detects the battery temperature TB is corrected, and high-temperature abnormality detection of the assembled battery 1 is detected using the corrected battery temperature (TB_htmp). To do. When it is determined that the detection value of the temperature sensor 22 has not changed due to the influence of the outside air temperature, the detection value of the temperature sensor 22 is not corrected and the detection value of the temperature sensor 22 is used as it is. High temperature abnormality detection is performed.

  FIG. 4 is a flowchart showing battery high temperature abnormality determination processing of the battery system in the present embodiment. The controller 30 can repeatedly perform the process shown in FIG. 4 at a predetermined timing and at an arbitrary interval.

  As shown in FIG. 4, in step S101, the controller 30 initializes the flags bxoffset_htmp and bxoffset_dep to OFF, and initializes variables T_offset_htmp and T_offset_dep to 0, respectively.

  In step S102, the controller 30 acquires the battery temperature TB, the current value Ib, and the outside air temperature T_out from each sensor. In step S103, the controller 30 determines whether or not the outside air temperature T_out is higher than the battery temperature TB. When the outside air temperature T_out is higher than the battery temperature TB, the controller 30 performs the battery high temperature abnormality determination process shown in FIG. 4, and when the outside air temperature T_out is lower than the battery temperature TB, the controller 30 accepts the allowable input shown in FIG. Perform power setting processing.

  When the outside air temperature T_out is higher than the battery temperature TB, the controller 30 proceeds to step S104 and determines whether or not bxoffset_htmp is OFF. When bxoffset_htmp is ON, it indicates a state where the temperature offset amount (correction value) is applied, that is, a state where the detection value of the temperature sensor 22 is corrected.

  When bxoffset_htmp is OFF, the controller 30 proceeds to step S105, and calculates a determination threshold value DT_htmp_pth (> 0) for temperature rise due to inflow of outside air.

  Here, as shown in FIG. 3, the factors that greatly change the detection value of the temperature sensor 22 include the case where the outside air flows into the battery pack 10 (the smoke exhaust path S) through the smoke exhaust duct 6, and the assembled battery 1. Current value Ib. The assembled battery 1 generates heat due to charging / discharging, and the amount of generated heat is the square of internal resistance × current value Ib. Therefore, in addition to the influence of outside air, heat generated by charging / discharging of the assembled battery 1 itself is taken into account. It is necessary to determine the fluctuation of the detection value of the temperature sensor 22.

  FIG. 5 is a diagram illustrating an example of a map (map A) for calculating a determination threshold value DT_htmp_pth (> 0) for temperature rise due to inflow of outside air. The temperature rise is a rate of temperature rise per unit time (dT / dt> 0).

The map A shown in FIG. 5 defines the temperature difference T_out-TB on the vertical axis and Ib ² (heat generation amount) on the horizontal axis. The larger the temperature difference and the larger the heat generation amount (current value Ib), the higher the temperature determination. The threshold value DT_htmp_pth is set to be large. That is, when the heat generation amount of the assembled battery 1 due to charging / discharging is large, it is determined that the influence of the outside air temperature is small as a factor of fluctuation of the detection value of the temperature sensor 22, and the heating amount of the assembled battery 1 itself due to charging / discharging is small At this time, it is determined that the influence of the outside air temperature is large as a factor of fluctuation of the detection value of the temperature sensor 22.

  For example, when a temperature change of 2 ° C. occurs in 10 seconds at the location marked “Small” in FIG. 5, the amount of generated heat is small, so even if the temperature difference is small, the variation in the detected value of the temperature sensor 22 is The determination threshold DT_htmp_pth is calculated to be small so that the outside air temperature is determined to be a factor. On the other hand, in the portion marked “Large”, for example, the amount of heat generated is large despite a temperature change of 10 ° C. in 10 seconds. In this case, even if the temperature difference is large, the determination threshold value DT_htmp_pth is calculated to be large assuming that the variation in the detection value of the temperature sensor 22 is caused by the heat generated by the assembled battery 1 itself more than the outside air temperature. In the example of FIG. 5, a region without temperature change can be set.

  In step S105, the controller 30 calculates the temperature difference T_out-TB using the detected values of the temperature sensor 22 and the outside air temperature sensor 25, and the calculated temperature difference T_out-TB and the current detected by the current sensor 21. Based on the value Ib, the determination threshold value DT_htmp_pth can be calculated from the map A shown in FIG.

  After calculating the determination threshold value DT_htmp_pth in step S105, the controller 30 proceeds to step S106. The controller 30 calculates the temperature change rate dT / dt per unit time from the battery temperature TB detected in step S102, and determines whether or not the temperature change rate dT / dt (> 0) is larger than the determination threshold value DT_htmp_pth. To do. When the temperature change rate dT / dt is larger than the determination threshold value DT_htmp_pth, the controller 30 determines that the detected value of the temperature sensor 22 has a temperature fluctuation due to the influence of the outside air temperature.

If it is determined in step S106 that the detected value of the temperature sensor 22 has a temperature fluctuation due to the influence of the outside air temperature, the controller 30 proceeds to step S107, and the temperature difference T_out−TB and the current value Ib (heat generation amount Ib) are detected. ² ) A temperature offset amount (correction value) T_offset_htmp according to ² ) is calculated.

FIG. 6 is a diagram illustrating an example of a calculation map of the temperature offset amount (correction value) according to the heat difference based on the temperature difference T_out−TB between the outside air temperature T_out and the detected value of the temperature sensor 22 and the current value Ib. In the map B shown in FIG. 6, the horizontal axis is the temperature difference T_out−TB, and the vertical axis is Ib ² (heat generation amount).

  As shown in FIG. 6, the temperature offset amount T_offset_htmp (> 0) is defined to increase as the temperature difference T_out−TB increases. This is because it is determined that the factor due to the outside air temperature is large and the “temperature measurement deviation” of the detection value of the temperature sensor 22 is large, and the correction value for the detection value of the temperature sensor 22 is also largely defined.

  On the other hand, the temperature offset amount T_offset_htmp is defined to be smaller as the heat generation amount (current value) is larger. When the factor due to the heat generation of the battery pack 1 itself is greater than the outside air temperature, it is determined that the “temperature measurement deviation” of the detection value of the temperature sensor 22 is small, and the correction value for the detection value of the temperature sensor 22 is reduced. This is because the actual battery temperature TB is close to the detection value of the temperature sensor 22.

  After calculating the temperature offset amount (correction value) T_offset_htmp in step S107, the controller 30 sets bxoffset_htmp to ON in step S108, and proceeds to step S110.

  In step S110, the controller 30 calculates the corrected battery temperature TB_htmp. Specifically, the corrected battery temperature TB_htmp is calculated by adding the temperature offset amount T_offset_htmp to the battery temperature TB.

  The controller 30 compares the correction value TB_htmp with the battery high temperature threshold value HTMP (S111), and determines that the assembled battery 1 is in a high temperature abnormal state when the battery temperature TB_htmp is higher than the battery high temperature threshold value HTMP (S112). When the battery temperature TB_htmp is equal to or lower than the battery high temperature threshold value HTMP, the controller 30 returns to step S102 and repeats the battery high temperature abnormality determination process and the like.

  In step S106, when the temperature change rate dT / dt is equal to or less than the determination threshold value DT_htmp_pth, the controller 30 assumes that the detection value of the temperature sensor 22 does not vary due to outside air and proceeds to step S109, and sets the temperature offset amount T_offset_htmp to “ Set to “0”. Zero correction for the battery temperature TB, that is, corrected battery temperature TB_htmp = battery temperature TB is calculated (S110).

  When it is determined that the assembled battery 1 is in an abnormal state of high temperature, the controller 30 may perform charge / discharge control of the assembled battery 1 with the upper and lower limit powers being limited as described above in order to protect the assembled battery 1. it can. Note that, for example, a technique described in Japanese Patent Application Laid-Open No. 2008-220088 can be applied as charge / discharge control of the assembled battery 1 that limits the upper and lower limit powers to be low depending on the battery temperature.

  In the present embodiment, when the outside air temperature T_out is higher than the battery temperature TB, it is determined whether or not the factor of fluctuation of the detection value of the temperature sensor 22 is due to the influence of the outside air temperature T_out. Depending on the temperature difference from the detection value (TB) of the sensor 22, the detection value of the temperature sensor 22 is corrected by the temperature offset amount T_offset_htmp, the battery temperature is estimated to be high, and the battery high temperature abnormality determination process is performed.

  With such a configuration, even if a “temperature measurement deviation” of the temperature sensor 22 caused by the influence of the outside air temperature occurs, the battery protection can be appropriately performed against the temperature rise of the assembled battery 1 caused by the influence of the outside air temperature. Then, the detection value of the temperature sensor 22 may be corrected each time according to the temperature variation of the assembled battery 1 due to the influence of the outside air temperature, and the assembled battery 1 is redundant in anticipation of the “temperature measurement deviation” caused by the influence of the outside air temperature T_out. Since it is not necessary to limit the upper and lower limit power of the input / output of the low, it is possible to suppress deterioration in fuel consumption.

  Further, the temperature offset amount T_offset_htmp is specified to increase as the temperature difference T_out-TB increases, and to decrease as the heat generation amount (current value) increases. In other words, when the factor due to the outside air temperature is large, the correction value for the detection value of the temperature sensor 22 is also increased and estimated to be higher than the actual battery temperature TB, and the battery high temperature abnormality determination process is performed at the estimated battery temperature. The assembled battery 1 can be protected on the safer side according to temperature fluctuations caused by the outside air temperature.

  On the other hand, when the factor due to the heat generation of the assembled battery 1 itself is larger than the outside temperature, the influence of the outside temperature is estimated to be low by performing a battery high temperature abnormality determination process at a battery temperature close to the actual battery temperature TB side of the assembled battery 1. Thus, the assembled battery 1 can be protected. In other words, the battery high-temperature abnormality determination process is performed without estimating the temperature fluctuation due to the “temperature measurement deviation” caused by the influence of the outside air temperature T_out, thereby protecting the battery in consideration of the charging / discharging temperature fluctuation of the assembled battery 1. Can do.

  Next, a case where bxoffset_htmp is ON in step S104 will be described. When bxoffset_htmp is ON, since the battery temperature TB_htmp is a state in which the correction value is applied to the detection value detected by the temperature sensor 22, the battery is corrected when it is no longer affected by the outside air temperature. It is necessary to return the temperature TB_htmp to the battery temperature TB detected by the temperature sensor 22.

  Therefore, when the temperature offset amount T_offset_htmp is added and the battery temperature TB_htmp is applied, the controller 30 determines whether or not the influence of the outside air temperature has been eliminated. The temperature offset amount T_offset_htmp is controlled not to be applied.

  In step S113, the controller 30 calculates a determination threshold value DT_htmp_mth for the temperature drop of the assembled battery 1. The temperature drop is a temperature drop rate per unit time (dT / dt <0).

In the map C shown in FIG. 7, the vertical axis defines the determination threshold value DT_htmp_mth, and the horizontal axis defines Ib ² (heat generation amount). The smaller the heat generation amount, the smaller the temperature decrease rate determination threshold value DT_htmp_mth is calculated. Is set to Unlike the map A shown in FIG. 5, the map C shown in FIG. 7 is on the descending side, so the determination threshold value DT_htmp_mth can be a negative value, and the small determination threshold value DT_htmp_mth is large as an absolute value. It means that.

  After calculating the determination threshold value DT_htmp_mth from the map C shown in FIG. 7 based on the current value detected by the current sensor 21, the controller 30 proceeds to step S114. The controller 30 calculates a temperature change rate dT / dt per unit time from the battery temperature TB detected in step S102, and the temperature change rate dT / dt (<0) is smaller than the determination threshold DT_htmp_mth (large as an absolute value). ) Or not. When the temperature change rate dT / dt is smaller than the threshold value DT_htmp_mth, the controller 30 determines that the influence of the outside air temperature has disappeared, and sets the set temperature offset amount (correction value) T_offset_htmp to “0” ( S115), bxoffset_htmp is set to OFF (S116).

  On the other hand, if it is determined in step S114 that the temperature change rate dT / dt is larger than the determination threshold value DT_htmp_mth, the controller 30 proceeds to step S117 and determines that the influence of the outside air temperature is not lost and is set. The previous value is set in T_offset_htmp so that the application of the correction value of the temperature offset amount T_offset_htmp is continued.

  FIG. 8 is a diagram showing the relationship between the change in the detected value of the temperature sensor 22 and the change in the current value Ib due to the outside air flowing into the battery pack 10 through the smoke exhaust duct 6. In the example of FIG. 8, when the outside air temperature T_out is also lower than the battery temperature TB, the temperature sensor 22 provided in the flue gas path S is affected by the outside air flowing in from the flue gas duct 6 to the low temperature side. An example of causing a "temperature measurement deviation" is shown.

  For example, even if the actual battery temperature TB is higher than the outside air temperature T_out, the detected value of the temperature sensor 22 rapidly drops (decreases) due to the influence of the outside air temperature T_out, and similarly, the actual battery temperature TB of the assembled battery 1 Can not be measured.

  It is known that when the battery pack 1 (unit cell 2) is charged with the battery temperature TB being low, the internal resistance is high, so that charging exceeds the upper limit voltage or high rate deterioration occurs. ing. For this reason, similarly to the temperature increase due to the influence of the outside air temperature described above, the detection value of the temperature sensor 22 that detects the battery temperature TB by correcting the temperature drop due to the influence of the outside air temperature is corrected, and the corrected battery is corrected. Input restriction of the assembled battery 1 can be performed using the temperature TB_htmp.

  FIG. 9 is a flowchart showing the setting process of the allowable input power (Win) of the battery system in the present embodiment. The process shown in FIG. 9 is performed by the controller 30, and is performed when the outside air temperature T_out is lower than the battery temperature TB in step S103 of FIG.

  As shown in FIG. 9, when the outside air temperature T_out is lower than the battery temperature TB based on the battery temperature TB and the outside air temperature T_out detected in Step S102 in Step S103 (NO in S103), the controller 30 performs Step. The process proceeds to S1101.

  In step S1101, the controller 30 determines whether or not bxoffset_dep is OFF. When bxoffset_dep is ON, the temperature offset amount (correction value) is applied, that is, the detection value of the temperature sensor 22 is corrected.

  When bxoffset_dep is OFF, the controller 30 proceeds to step S1102, and calculates a determination threshold value DT_dep_mth (<0) for temperature drop due to inflow of outside air.

  FIG. 10 is a diagram illustrating an example of a map (map A1) for calculating a determination threshold value DT_dep_mth (<0) for a temperature drop due to outside air inflow. The temperature drop is a temperature drop rate per unit time (dT / dt <0).

The map A1 shown in FIG. 10 defines the temperature difference T_out-TB on the vertical axis and Ib ² (heat generation amount) on the horizontal axis, and the temperature drop is determined as the temperature difference is larger and the heat generation amount (current value Ib) is smaller. The threshold value DT_dep_mth is set to be large. That is, when the heat generation amount of the assembled battery 1 due to charging / discharging is small, it is determined that the influence of the outside air temperature is large as a factor of fluctuation of the detection value of the temperature sensor 22, and the heating amount of the assembled battery 1 itself due to charging / discharging is large At this time, it is determined that the influence of the outside air temperature is small as a factor of fluctuation of the detection value of the temperature sensor 22. In the example of FIG. 10 as well, a region without temperature change can be set.

  In step S1102, the controller 30 calculates the temperature difference T_out-TB using the detected values of the temperature sensor 22 and the outside air temperature sensor 25, and the calculated temperature difference T_out-TB and the current detected by the current sensor 21. Based on the value Ib, the determination threshold value DT_dep_mth can be calculated from the map A1 shown in FIG.

  In step S1103, the controller 30 calculates the temperature change rate dT / dt per unit time from the battery temperature TB detected in step S102, and whether the temperature change rate dT / dt (<0) is smaller than the determination threshold DT_dep_mth. It is determined whether (absolute value is large) or not. When the temperature change rate dT / dt is smaller than the determination threshold value DT_dep_mth, the controller 30 determines that the detected value of the temperature sensor 22 has a temperature fluctuation due to the influence of the outside air temperature.

In step S1104, the controller 30 calculates a temperature offset amount (correction value) T_offset_htmp corresponding to the temperature difference T_out−TB and the current value Ib (heat generation amount Ib ² ). At this time, since the temperature falls, a negative value is applied as the temperature offset amount calculated as the correction value.

FIG. 11 is a diagram illustrating an example of a calculation map of the temperature offset amount (<0) corresponding to the heat generation amount based on the temperature difference T_out−TB between the outside air temperature T_out and the detected value of the temperature sensor 22 and the current value Ib. In the map B1 shown in FIG. 11, the horizontal axis represents the temperature difference T_out-TB, and the vertical axis represents Ib ² (heat generation amount). In the map B1 shown in FIG. 11, the temperature offset amount T_offset_dep is the same as the map B shown in FIG. 6, and the temperature offset amount is specified to be smaller (larger in absolute value) as the temperature difference T_out−TB is larger. Has been. Further, it is defined that the larger the heat generation amount (current value), the larger (smaller as an absolute value).

  After calculating the temperature offset amount (correction value) T_offset_dep in step S1104, the controller 30 sets bxoffset_dep to ON in step S1105, and proceeds to step S1107.

  In step S1107, the controller 30 calculates the corrected battery temperature TB_dep. Specifically, the corrected battery temperature TB_dep is calculated by adding the temperature offset amount T_offset_dep to the battery temperature TB. At this time, since the temperature offset amount T_offset_dep is a negative value, the temperature offset amount T_offset_dep is corrected to be subtracted from the battery temperature TB.

  The controller 30 calculates the allowable input power Win of the battery pack 1 using the battery temperature TB_dep and the current value Ib detected by the current sensor 21 (S1108). The controller 30 performs charge / discharge control of the assembled battery 1 using the calculated allowable input power Win as the upper limit value of the charge power. Note that the method described in Japanese Patent No. 5223920 can be applied to the setting of the allowable input power Win using the battery temperature and the current value, for example.

  In step S1103, when the temperature change rate dT / dt is equal to or greater than the determination threshold value DT_dep_mth, the controller 30 proceeds to step S1106 assuming that there is no change due to the outside air with respect to the detection value of the temperature sensor 22, and the temperature offset amount T_offset_dep. Is set to “0”. The corrected battery temperature TB_dep = battery temperature TB is calculated (S1107).

  Similarly, in the process shown in FIG. 9, when the battery temperature is corrected and then no longer affected by the outside air temperature, the corrected battery temperature TB_htmp is corrected by adding (subtracting) the temperature offset amount T_offset_dep, It is necessary to return to the battery temperature TB detected by the temperature sensor 22.

  For this reason, when bxoffset_dep is ON in step S1101, the controller 30 proceeds to step S1109, determines whether the influence of the outside air temperature has been eliminated, and if it is determined that there is no influence of the outside air temperature, Control is performed so as not to apply the temperature offset amount T_offset_dep.

  In step S1109, the controller 30 calculates a determination threshold value DT_dep_pth for the temperature rise of the assembled battery 1. The temperature rise is a rate of temperature rise per unit time (dT / dt> 0).

A map C1 shown in FIG. 12 has a determination threshold value DT_dep_pth on the vertical axis and Ib ² (heat generation amount) on the horizontal axis. The smaller the heat generation amount, the smaller the temperature increase rate determination threshold DT_dep_pth is calculated. Is set to Unlike the map A1 shown in FIG. 10, the map C1 shown in FIG. 12 is on the ascending side, so the determination threshold value DT_dep_pth can be a positive value.

  When the controller 30 calculates the determination threshold DT_dep_pth from the map C1 shown in FIG. 12 based on the current value detected by the current sensor 21, the process proceeds to step S1110. The controller 30 calculates the temperature change rate dT / dt per unit time from the battery temperature TB detected in step S102, and determines whether or not the temperature change rate dT / dt (> 0) is larger than the determination threshold value DT_dep_pth. To do. When the temperature change rate dT / dt is larger than the threshold value DT_dep_pth, the controller 30 determines that the influence of the outside air temperature has disappeared, and sets the set temperature offset amount (correction value) T_offset_dep to “0” ( S1111), bxoffset_dep is set to OFF (S1112).

  On the other hand, if it is determined in step S1110 that the temperature change rate dT / dt is smaller than the determination threshold value DT_dep_pth, the controller 30 proceeds to step S1113 and determines that the influence of the outside air temperature is not lost and is set. The previous value is set to T_offset_dep so that the application of the correction value of the temperature offset amount T_offset_dep is continued.

  In the present embodiment, when the outside air temperature T_out is lower than the battery temperature TB, it is determined whether or not the cause of fluctuation in the detection value of the temperature sensor 22 is due to the influence of the outside air temperature T_out. According to the temperature difference from the detection value (TB) of the sensor 22, the detection value of the temperature sensor 22 is corrected by the temperature offset amount T_offset_dep, the battery temperature is estimated lower, and the allowable input power Win of the assembled battery 1 is set. Set.

  With such a configuration, battery protection can be appropriately performed against a temperature drop of the assembled battery 1 due to the influence of the outside air temperature, and the detected value of the temperature sensor 22 each time according to the temperature fluctuation of the assembled battery 1 due to the influence of the outside air temperature. Therefore, it is not necessary to limit the allowable input power of the assembled battery 1 to an extra low in anticipation of the “temperature measurement deviation” caused by the influence of the outside air temperature T_out, so that deterioration of fuel consumption can be suppressed.

  Similarly to the above-described temperature offset amount T_offset_htmp, the temperature offset amount T_offset_dep is specified to increase as the temperature difference T_out-TB increases and to decrease as the heat generation amount (current value) increases. For this reason, when the factor due to the outside air temperature is large, the temperature fluctuation due to the “temperature measurement deviation” caused by the influence of the outside air temperature T_out is estimated to be high, and the allowable input power of the battery assembly 1 is limited to be smaller, thereby making the battery assembly 1 safer. When the factor due to the heat generation of the battery pack 1 itself is larger than the outside air temperature, the charging / discharging of the battery pack 1 is not estimated without estimating the temperature fluctuation due to the “temperature measurement deviation” caused by the influence of the outside air temperature T_out. Battery protection considering temperature fluctuations can be achieved.

1: assembled battery, 2: single cell, 3: intake duct, 3a: intake port, 4: blower, 5: exhaust duct, 5a: exhaust port, 6: smoke exhaust duct, 20: monitoring unit, 21: current sensor, 22: Temperature sensor, 23: Inverter, 24: Motor generator, 25: Outside air temperature sensor, 30: Controller, 31: Memory, 100: Vehicle, 101: Seat SMR-B, SMR-G: System main relay, PL: Positive line, NL: Negative line, C: Case, S: Smoke path

Claims (1)

A vehicle including a power storage stack composed of a plurality of power storage elements, and mounted with a power storage pack in which the power storage stack is accommodated inside a case,
A duct communicating the inside of the case with the outside of the vehicle;
A temperature sensor for measuring the temperature of the electricity storage stack;
An outside air temperature sensor that measures the outside air temperature outside the vehicle,
A current sensor for measuring a current flowing through the power storage stack;
A controller that controls charging / discharging of the electricity storage stack, and performs input / output control that limits an upper limit value of input / output power of the electricity storage stack,
The controller is based on temperature difference information that is a temperature difference between the detected value of the temperature sensor and the outside air temperature, and current information that is an amount of current flowing through the power storage device, and is influenced by the outside air temperature via the duct. The detection value of the temperature sensor is detected, and the detection value of the temperature sensor is corrected based on the temperature difference information and the current information in accordance with the detection of the detection value change. While performing the input / output control using the detected value,
Further, the larger the temperature difference is, the larger the correction amount for the detection value of the temperature sensor is, and the larger the current amount is, the smaller the correction amount is, and the detection value of the temperature sensor is corrected. vehicle.

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