JP5879983B2 - Battery control device - Google Patents

Description

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

  An apparatus for detecting an abnormality in a power storage device configured by connecting a plurality of power storage units including at least one power storage element, wherein a plurality of processes for equalizing variation in capacity or voltage of each of the plurality of power storage units When the equalization processing unit finishes one equalization process, the time interval between the one equalization process executed before the one equalization process is calculated. When the time interval calculated by the equalization processing interval calculation unit and the equalization processing interval calculation unit is shorter than the time set as the power storage device should be determined to be in a state close to an abnormal state, An abnormality occurrence warning determination unit that determines that the power storage device is in a state close to an abnormal state, and measurement after the determination when the abnormality occurrence warning determination unit determines that the power storage device is in a state close to an abnormal state Said storage An abnormality determination value calculation unit that calculates an abnormality determination value that is obtained by integrating the absolute value of the charge / discharge current of the power storage device using the charge / discharge capacity of the device, and an abnormality determination value that is calculated by the abnormality determination value calculation unit. An abnormality detection of a power storage device comprising: an abnormality determination processing unit that determines that the power storage device is in an abnormal state when the power storage device is equal to or greater than a predetermined reference value set to be determined as an abnormal state. An apparatus is known (Patent Document 1).

JP 2008-134060 A

  However, there is a problem in that the charge / discharge current cannot be integrated during the pause period in which the abnormality detection apparatus is paused, and it is not possible to detect a battery abnormality occurring during the pause period.

  The problem to be solved by the present invention is to provide a control apparatus for an assembled battery that can detect a minute short circuit that occurs during an idle period.

  The present invention uses an adjustment time actually required until the voltage or state of charge of a plurality of single cells is adjusted to a target value, the number of adjustments per unit time actually adjusted using the adjustment means, or an adjustment means. The difference between the slope of the calculated value before the pause period of the control device and the slope of the calculated value after the pause period is within a predetermined range, and before and after the pause period. When the amount of change in the calculated value is larger than a threshold value indicating a micro short circuit, the above problem is solved by determining that the battery malfunction is caused by the micro short circuit in the battery pack.

  According to the present invention, by comparing the slopes of the calculated values before and after the suspension period, it is possible to grasp the change in the calculated values due to the battery deterioration during the suspension period, and then from the amount of change in the calculated values before and after the suspension period, Therefore, the abnormality of the assembled battery due to the minute short circuit can be detected with high accuracy.

It is a block diagram of the assembled battery system containing the control apparatus of the assembled battery which concerns on embodiment of this invention. It is a block diagram of the battery controller of FIG. It is a graph which shows the characteristic of the adjustment time with respect to time in the assembled battery of FIG. It is a flowchart which shows the control procedure in the battery controller of FIG. 6 is a graph showing characteristics of adjustment time with respect to time in an assembled battery in an assembled battery control device according to another embodiment of the present invention. It is a flowchart which shows the control procedure of a battery controller in the control apparatus of the assembled battery which concerns on other embodiment of this invention. It is a graph which shows the characteristic of the adjustment time with respect to time in the control apparatus of the assembled battery which concerns on the example of a change of this invention.

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

<< First Embodiment >>
FIG. 1 is a configuration diagram of an assembled battery system including an assembled battery control device according to the present embodiment. In the following, a case where the assembled battery system according to the present embodiment is used as a battery for a vehicle such as a hybrid vehicle or an electric vehicle will be described as an example.

  As shown in FIG. 1, the assembled battery system according to the present embodiment includes an assembled battery 100 including a plurality of unit cells C1 to CN connected in series, a load 200 electrically connected to both ends of the assembled battery 100, and an assembled battery. A capacity adjustment circuit 400 for adjusting the capacity of the battery 100 and a battery controller 500 for controlling the entire assembled battery system are provided.

  The assembled battery 100 is configured by connecting N unit cells C1 to CN in series. Examples of the single cells C1 to CN include alkaline storage batteries such as nickel metal hydride batteries and organic electrolyte secondary batteries such as lithium ion batteries. In this embodiment, lithium ion batteries are used as the single cells C1 to CN. An example will be described. In addition, the single cells C1 to CN are connected in parallel, and include a plurality of batteries that have the same terminal voltage that can be measured and can be regarded as single cells. Note that the number N of unit cells is not particularly limited, and can be appropriately set as desired. In addition, the assembled battery 100 includes a temperature sensor 102 for measuring the temperature of the single cells C <b> 1 to CN constituting the assembled battery 100. The battery temperature measured by the temperature sensor 102 is transmitted to the battery controller 500.

  A capacity adjustment circuit 400 is connected in parallel to each of the N unit cells C <b> 1 to CN constituting the assembled battery 100. The capacity adjustment circuit 400 includes a resistor 401 and a switch 402. The capacity adjustment of the unit cell can be performed by closing the switch 402 and performing the capacity adjustment discharge of the unit cell. The opening / closing of each switch 402 is controlled by the battery controller 500.

  The load 200 is, for example, a motor and an inverter mounted on a hybrid vehicle, an electric motor vehicle, or the like. For example, during regenerative control, the load 200 is reversely converted into electric energy via the motor and the inverter, and the assembled battery 100 is charged. It is possible. The assembled battery 100 can be charged by being connected to an external power source (not shown), for example.

  FIG. 2 is a functional block diagram of the battery controller 500. As shown in FIG. 2, the battery controller 500 includes a voltage detection unit 501, a current detection unit 502, a battery temperature detection unit 503, a capacity adjustment unit 504, a control unit 505, an abnormality determination unit 506, a storage unit 507, a calculation unit 508, A notification unit 509 and a communication unit 510 are provided.

  The voltage detection unit 501 measures the voltage value of the terminal voltage of each of the cells C1 to CN constituting the assembled battery 100 in a time-series manner at a predetermined cycle via a plurality of terminal wires connected to each cell. Then, the terminal voltage of each single cell detected and measured is converted from an analog signal to a digital signal and sent to the control unit 505. In addition, as a method of measuring the terminal voltage of each single cell, a flying capacitor system etc. are mentioned, for example.

  The current detection unit 502 acquires the charging / discharging current detected by the current sensor 300 at a predetermined period, converts the acquired charging / discharging current from an analog signal to a digital signal, and sends the converted signal to the control unit 505. Note that the current sensor 300 includes, for example, a resistance element, a current transformer, and the like.

  The battery temperature detection unit 503 acquires the temperatures of the individual cells C1 to CN measured by the temperature sensor 102 provided in the assembled battery 100 at a predetermined cycle, and the acquired temperatures of the individual cells C1 to CN are analog signals. Is converted into a digital signal and sent to the control unit 505.

  When the variation in the terminal voltage or the state of charge (SOC: State of Charge) of each unit cell C1 to CN becomes equal to or greater than a predetermined value between the unit cells C1 to CN, the capacity adjustment unit 504 On the basis of the capacity adjustment command, the opening / closing of each switch 402 provided in each capacity adjustment circuit 400 is controlled, whereby the capacity of the assembled battery 100 is adjusted.

The control unit 505 supplies the capacity adjustment unit 504 with the capacity based on the terminal voltage, charge / discharge current, and battery temperature data received from the voltage detection unit 501, current detection unit 502, and battery temperature detection unit 503. Capacitance adjustment control is performed for adjustment. Specifically, the control unit 505 first sets a target equalization voltage V _tar that is a voltage for making the voltages of the individual cells C1 to CN constituting the assembled battery 100 uniform. The target equalization voltage V _tar is not particularly limited and can be set arbitrarily. For example, the lowest voltage among the voltages of the cells C1 to CN is set as the target equalization voltage V _tar . Alternatively, a predetermined voltage near the full charge of the assembled battery 100 or a predetermined voltage (for example, a full charge voltage or a predetermined voltage near the full charge voltage) is set in advance as the target equalization voltage V _tar. It may be set. The target equalization voltage V _tar set in this way is stored in a memory (not shown) provided in the battery controller 500. And the control part 505 calculates | requires the maximum voltage value and the minimum voltage value from the voltage between terminals of each cell C1-CN, and also calculates the voltage difference. When the voltage difference becomes equal to or greater than a preset voltage difference threshold value, the unit cells C1 to CN constituting the assembled battery 100 are uniformly supplied to the capacity adjustment unit 504 at the target equalization voltage _Vtar . A capacity adjustment command for performing control to obtain a correct voltage is generated, and the generated capacity adjustment command is sent to the capacity adjustment unit 504.

  Here, the voltage difference threshold corresponds to the magnitude of variation of each unit cell, and is a threshold at which the variation condition becomes stricter by decreasing the threshold, and the variation condition becomes gradual by increasing the threshold. . In this example, the voltage difference threshold value may be arbitrarily changed.

Then, the capacity adjustment unit 504 performs capacity adjustment by turning on the switches 402 of the cells C1 to CN to be adjusted during the adjustment time calculated by the calculation unit 509 described later based on the capacity adjustment command. Do. The voltage detector 501 detects the voltage of the single cell even during capacity adjustment. Then, when the detected voltage of the single battery during capacity adjustment reaches the target equalization voltage V _tar , the control unit 505 transmits a command to end the capacity adjustment to the capacity adjustment unit 504. The capacity adjustment unit 504 ends the capacity adjustment by turning off the switch 402 based on the command. The capacity adjustment unit 504 and the control unit 505 perform capacity adjustment in the same manner for other adjustment target batteries. Accordingly, the capacity adjustment unit 504 controls the on / off of each switch 402, thereby performing the control so that the voltages of the individual cells C1 to CN are uniform at the target equalization voltage _Vtar . Adjustments can be made. Alternatively, the capacity adjustment unit 504 performs capacity adjustment so that each of the single cells C1 to CN has a predetermined voltage by controlling on and off of each switch 402 based on the capacity adjustment command, and thereafter In the assembled battery 100, it is also possible to perform control such that the voltage of each of the single cells C1 to CN becomes uniform at the target equalization voltage V _tar by being repeatedly charged and discharged.

  The abnormality determination unit 506 detects a micro short-circuit generated in the assembled battery 100 using the data regarding the capacity adjustment of the cells C1 to CN stored in the storage unit 507, and determines the abnormality of the assembled battery 100. It is a judgment part. In addition, the control for abnormality determination of the assembled battery 100 in the abnormality determination part 506 is mentioned later.

  The storage unit 507 is a time series of data related to the capacity adjustment of the battery pack 100 such as the adjustment time required for adjusting the capacity of the cells C1 to CN, the adjustment start time or the end time, which are the calculation values calculated by the calculation unit 508. It is a memory to store.

The calculation unit 508 uses the capacity adjustment unit 504 to calculate the time until the voltage of each of the cells C1 to CN becomes the target equalization voltage V _tar as the adjustment time. In the case of adjusting the capacity by discharging, the adjustment time for adjusting the capacity corresponds to the time for which each switch 402 is turned on. Since the on / off control of the switch 402 is controlled by the capacity adjustment unit 504, the calculation unit 509 measures the on-time of the switch 402 in the control of the capacity adjustment unit 504, thereby obtaining the actual capacity adjustment time. It can be calculated. Then, the calculation unit 508 stores the calculated adjustment time in the storage unit 507 in association with the time when the capacity adjustment is performed.

Since the capacity adjustment time can be calculated from the detection voltage of each single cell C1 to CN and the resistance value of the resistor 401, the calculation unit 509 adjusts the capacity by calculation using the detection voltage of each single cell C1 to CN. You may calculate time. Also, when the capacity adjustment by charging and discharging, from the time of adjustment start, when the voltage of each cell C1~CN to calculating the time until the targeted equalization voltage V _tar, calculates the capacity adjustment time May be.

  When the abnormality determination unit 506 detects an abnormality in the assembled battery 100, the notification unit 509 notifies the abnormality of the assembled battery 100 by turning on a warning lamp (not shown). The communication unit 510 is a communication device that communicates the result of the abnormality determination of the assembled battery 100 determined by the abnormality determination unit 506 to the outside.

  Next, the abnormality determination control of the assembled battery 100 in the battery controller 500 will be described with reference to FIGS. FIG. 3 is a graph showing characteristics of adjustment time with respect to time.

  In order for the abnormality determination unit 506 to determine abnormality of the assembled battery 100, the calculation unit 508 uses the data relating to capacity adjustment of the assembled battery 100 stored in the storage unit 507, and the inclination of the adjustment time arranged in time series. Is calculated. In addition, the calculation unit 508 calculates the amount of change in the adjustment time before and after the suspension period in which the abnormality determination unit 506 is not operating, using the data.

  The suspension period is a period during which the abnormality determination unit 506 is not monitoring the abnormality of the assembled battery 100. For example, when the abnormality determination unit 506 monitors an abnormality of the assembled battery 100 in conjunction with turning on and off of a relay switch (not shown) connected between the assembled battery 100 and the load 200, the suspension period Corresponds to the OFF period of the relay switch. Alternatively, when the abnormality determination unit 506 monitors an abnormality of the assembled battery 100 in conjunction with turning on and off of a main switch (not shown) of the vehicle, the suspension period corresponds to an off period of the main switch.

Next, transition of adjustment time when arranged in time series will be described with reference to FIG. As shown in FIG. 3, the period from time (0) to time (t ₁ ) and the period after time (t ₂ ) are the operating period in which the abnormality determination unit 506 is operating, A period from t ₁ ) to time (t ₂ ) is a pause period in which the abnormality determination unit 506 is not operating.

  During the operation period, the assembled battery 100 supplies electric power to the load 200 or is charged by regenerative control of a motor included in the load 200, so that variation occurs in the voltage between the cells C1 to CN. When the voltage difference between the cells C <b> 1 to CN reaches the voltage difference threshold, the capacity adjustment unit 504 performs capacity adjustment.

Since the voltage difference between the cells C1 to CN increases with the progress of deterioration of the battery pack 100 with time, the adjustment time for capacity adjustment also increases with the passage of time. Therefore, as shown in FIG. 3, during the operation time, the adjustment time becomes longer in proportion to the passage of time. In addition, a slope S ₁ (adjustment time per unit time) of the adjustment time with respect to the time during the operation period is a change rate of the adjustment time due to deterioration of the assembled battery 100.

When the operation time is finished at time (t ₁ ) and there is no variation in the voltage between the cells C1 to CN, the capacity is limited as long as there is no variation in the voltage during the suspension period (t _{1 to} t ₂ ). Adjustment is not performed and adjustment time data is not acquired.

  Here, it is assumed that a minute short circuit occurs in the assembled battery 100 during the suspension period. In such a case, since the voltage drop occurs in the unit cell in which the micro short circuit has occurred, the voltage difference between the unit cell in which the micro short circuit has occurred and the voltage of another normal unit cell is widened. The micro short circuit does not occur with the passage of time like the deterioration of the capacity of the single cells C1 to CN and the deterioration of the internal resistance, and may occur in the short term even when the usage period of the single cells C1 to CN is short. . And when a micro short circuit occurs, the voltage effect at the time of micro short circuit generation becomes large compared with the voltage drop by degradation of single cells C1-CN.

Therefore, when the time becomes busy period again _{(t 2),} the adjustment time of the time _{(t 2),} longer than the adjustment time of the time _{(t 1).} In the operation time after the time (t ₂ ), the adjustment time becomes longer in proportion to the time due to the deterioration of the assembled battery 100 as in the operation time up to the time (t ₁ ). The inclination (S ₂ ) of the adjustment time of the operation time after the time (t ₂ ) is the same as the inclination (S ₁ ) of the adjustment time of the operation time before the time (t ₁ ).

By the way, unlike this example, when an abnormality of the assembled battery 100 is detected only by comparing the slope of the adjustment time and the threshold during the operation period, as shown in FIG. When this occurs, there is no significant difference between the slopes before and after the suspension period (S ₁ and S ₂ ), so there is a possibility that an abnormality in the assembled battery 100 due to a minute short circuit during the suspension period may be missed.

  Therefore, in this example, the abnormality determination unit 506 determines the abnormality of the assembled battery 100 due to a minute short circuit in the assembled battery 100 from the slope of the adjustment time before and after the suspension period and the amount of change in the adjustment time before and after the suspension period as follows. Determine.

The abnormality determination unit 506 determines whether or not a minute short circuit has occurred during re-operation after the suspension period. After detecting the abnormality determination unit 506 again so that the abnormality due to the deterioration of the battery pack 100 is not erroneously determined to be an abnormality due to the minute short circuit when the minute short circuit is detected, the calculation unit 508 causes the inclination of the adjustment time (S ₂ ) Is calculated. Then, the abnormality determination unit 506 calculates a difference (S ₂ ) between the slope of the adjustment time before the pause period (S ₁ ) and the slope of the adjustment time before the pause period (S ₂ ) calculated by the calculation unit 508. -S ₁₎ to calculate the.

When calculating the slopes (S ₁ and S ₂ ), the calculation unit 508 arranges the adjustment times stored in the storage unit 507 in time series, takes the adjustment time on the x axis and the adjustment time on the y axis, and performs linear regression. The slope may be calculated approximately from the regression line. Alternatively, it may be calculated from a plurality of adjustment time which is calculated in the time close to the time t ₁ and time t _2.

In the abnormality determination unit 506, an allowable range (−Sc to Sc) that is a range indicating the amount of change in the inclination of the adjustment time in consideration of the deterioration of the assembled battery 100 over time, the adjustment time error, and the like is set in advance. ing. Then, the abnormality determination unit 506 determines whether or not the slope difference (S ₂ −S ₁ ) is within an allowable range. When the difference in slope (S ₂ −S ₁ ) is within the allowable range, the abnormality determination unit 506 determines that the change in the adjustment time is due to the deterioration of the battery pack 100 over time. On the other hand, when the difference in slope (S ₂ −S ₁ ) is outside the allowable range, the abnormality determination unit 506 determines that an abnormality has occurred due to an abnormality of the resistor 401 or the like.

When the difference in slope (S ₂ −S ₁ ) is within the allowable range, in order to detect a minute short circuit during the suspension period, the calculation unit 508 sets the adjustment time immediately before the suspension period to the time before the suspension period. Calculation is performed as an adjustment time (adjustment time with respect to time t _{1 in} FIG. 3). The arithmetic unit 508, re-run, and calculates first adjustment time when the capacity adjustment has been made, as an adjustment time after pause period (adjustment time with respect to time t ₂ in FIG. 3). And the calculating part 508 calculates the variation | change_quantity ((DELTA) A) of the adjustment time before and behind a pause period by taking the difference of the adjustment time before a pause time from the adjustment time after a pause time (refer FIG. 3).

  In the abnormality determination unit 506, a determination threshold (Ac) is set in advance as a threshold indicating that a minute short circuit has occurred. Then, the abnormality determination unit 506 compares the change amount (ΔA) with the determination threshold value (Ac). When the amount of change (ΔA) is larger than the determination threshold value (Ac), the abnormality determination unit 506 determines that a minute short circuit has occurred during the suspension period and an abnormality has occurred in the assembled battery 100 due to the minute short circuit. To do. On the other hand, when the amount of change (ΔA) is smaller than the determination threshold (Ac), the abnormality determination unit 506 determines that the assembled battery 100 is normal.

  Next, the control procedure of the battery controller 500 of this example will be described with reference to FIG. FIG. 4 is a flowchart showing a control procedure of the battery controller 500. Note that the control loop shown in FIG. 4 is repeated if it is determined that the assembled battery 100 is normal.

  In step S1, voltage detection unit 501 detects the terminal voltages of single cells C1 to CN at a predetermined cycle. In step S <b> 2, the control unit 505 specifies the highest voltage and the lowest voltage from the detection voltages of each unit cell, and calculates the voltage difference (ΔV) by taking the difference between the highest voltage and the lowest voltage. .

  In step S3, the control unit 505 compares the voltage difference (ΔV) with a voltage difference threshold value. If the voltage difference (ΔV) is less than the voltage difference threshold, it is determined that there is no variation between the cells, and the process returns to step S1. On the other hand, if the voltage difference (ΔV) is greater than or equal to the voltage difference threshold, in step S4, the control unit 505 transmits a capacity adjustment command to the capacity adjustment unit 504, and the capacity adjustment unit 504 switches the switch based on the command. 402 is turned on to adjust the capacity.

In step S5, the capacity adjustment unit 504 determines from the detection voltage of the voltage detection unit 501 whether or not the voltages of all the unit cells that have been subjected to capacity adjustment have reached the target equalization voltage V _tar. Then, it is determined whether or not the capacity adjustment is completed. When the capacity adjustment is not completed, the capacity adjustment control by the capacity adjustment unit 504 is continued. When the capacity adjustment is completed, the process proceeds to step S6.

  In step S6, the calculation unit 508 calculates the adjustment time in the capacity adjustment control in step and step S5, and stores it in the storage unit 507 while corresponding to the adjusted time. In step S7, the control unit 505 determines whether or not to perform abnormality determination control by the abnormality determination unit 506. In this example, in order to perform abnormality determination control mainly for detecting a minute short circuit during the suspension period, the control unit 505 performs the abnormality determination control of this example, for example, when driving again after the suspension period. Note that the control unit 505 may detect whether or not re-driving is performed based on a signal from a main switch (not shown). And when not performing abnormality determination control, control of this example is complete | finished.

When performing abnormality determination control, in step S71, the calculation unit 508 calculates the slopes (S ₁ and S ₂ ) of the adjustment time before and after the suspension period from the data stored in the storage unit 507. In step S <b> 72, the calculation unit 508 calculates a change amount (ΔA) of the adjustment time before and after the suspension period from the data stored in the storage unit 507.

In step S73, the abnormality determination unit 506 determines that the difference (S ₂ −S ₁ ) in the slope of the adjustment time before and after the suspension period is within the allowable range (−Sc to Sc), that is, the difference is greater than −Sc. It is determined whether it is smaller. If the difference in slope (S ₂ −S ₁ ) is within the allowable range (−Sc to Sc), in step S 74, the abnormality determination unit 506 determines whether the change amount (ΔA) is greater than the determination threshold (Ac). Determine whether or not.

  If the change amount (ΔA) is larger than the determination threshold value (Ac), the abnormality determination unit 506 determines in step S75 that an abnormality has occurred in the assembled battery 100 due to a minute short circuit in the assembled battery 100. To do. The control unit 505 controls the notification unit 509 and the communication unit 510 based on the abnormality determination of the minute short circuit by the abnormality determination unit 506, and the notification unit 509 notifies that the abnormality due to the minute short circuit has occurred, and the communication unit 510. Transmits to the outside that an abnormality has occurred due to a short circuit.

Returning to step S73, if the difference in slope (S ₂ −S ₁ ) is outside the allowable range (−Sc to Sc), in step S76, the abnormality determination unit 506 determines other than a short circuit during the pause period. It is determined that an abnormality has occurred due to other factors.

  Returning to step S74, when the amount of change (ΔA) is equal to or less than the determination threshold value (Ac), the abnormality determination unit 506 determines that the assembled battery 100 is normal and ends the control of this example.

  As described above, in the present invention, the abnormality determination unit 506 includes the slope of the adjustment time before the suspension period and the slope of the adjustment time after the suspension period of the abnormality determination unit 506 included in the control device of the assembled battery 100. When the difference is within the allowable range and the amount of change in the adjustment time before and after the suspension period is larger than the determination threshold value indicating the micro short circuit, the battery pack 100 is abnormal due to the micro short circuit in the battery pack 100. judge. Thus, in this example, by confirming that the change in the inclination of the adjustment time before and after the suspension period is small, it is confirmed that the battery is not affected by sudden deterioration or subjective disturbance of the assembled battery 100. Thus, since the abnormality of the micro short circuit is determined based on the amount of change in the adjustment time before and after the suspension period, the abnormality of the assembled battery 100 due to the micro short circuit can be accurately detected. Moreover, this example can detect the abnormality of the assembled battery 100 by the micro short circuit during a rest period with high precision.

  Further, in this example, the notification unit 509 notifies the abnormality of the assembled battery 100. Thereby, the user can confirm the abnormality of the assembled battery 100. Further, when an abnormality occurs in the assembled battery 100, the notification unit 509 notifies the abnormality due to the minute short circuit of the assembled battery 100 to the outside such as the center via the communication unit 510, whereby the same battery as the assembled battery 100 is obtained. The possibility of future abnormalities in can be alerted.

  In this example, the calculation unit 508 calculates the adjustment time for capacity adjustment, and the abnormality determination unit 506 detects an abnormality in the assembled battery 100 due to a minute short circuit based on the adjustment time. However, the calculation unit 508 performs the capacity adjustment. The number of adjustments per unit time may be calculated, and the abnormality determination unit 506 may detect an abnormality in the assembled battery 100 due to a minute short circuit based on the number of adjustments per unit time.

  Since the voltage difference between the cells C1 to CN increases with the progress of the deterioration of the battery pack 100 over time, the number of adjustments per unit time of capacity adjustment increases with time. Then, by arranging the data of the number of adjustments per unit time in a time series in which capacity adjustment is performed, taking the x-axis as the time and the y-axis as the number of adjustments per unit time, as in FIG. 3, it is proportional to the time. A graph in which the number of adjustments per unit time is increased is obtained.

  In addition, when a micro short circuit occurs, a voltage drop occurs in the single cell in which the micro short circuit occurs, the voltage difference between the single cells C1 to CN is further increased, and the number of adjustments per unit time after the micro short circuit is further increased. Become more. And when a micro short circuit arises during an idle period, transition of the frequency | count of adjustment per unit time with respect to time shows the same characteristic as FIG.

  Therefore, in the abnormality determination control of the assembled battery 100 by the battery controller 500 described above, the adjustment time is replaced with the number of adjustments per unit time, so that even when the number of adjustments per unit time is used, Abnormality of the battery 100 can be detected.

  In this example, the control unit 505 may use the temperature detected by the temperature sensor 102 when determining the variation in capacity using the SOCs of the cells C1 to CN. The SOC of the unit cell and the detected voltage of the unit cell have a certain correlation, but the correlation has a temperature dependency. Then, depending on the battery characteristics, how the voltage-SOC curve changes with respect to the battery temperature is determined in advance. Therefore, the control unit 505 calculates the SOC by calculating the corresponding SOC with reference to the curve from the detected temperature of the single cell, and correcting according to the temperature sensor 102.

  In this example, the resistance value of the resistor 401 is a fixed value, but the resistor 401 may be a variable resistor. In addition, when the resistor 401 is a variable resistor, the calculation unit 508 adjusts the battery adjustment capacity (charge / discharge) until the variation of the cells C1 to CN is adjusted instead of the adjustment time and the number of adjustments per unit time. Capacity). The adjustment capacity corresponds to the difference between the capacity of the battery before capacity adjustment and the capacity of the battery after capacity adjustment.

  The control unit 505 sets the resistance value of the resistor 401 when the capacitance adjustment unit 504 performs capacitance adjustment. Further, the control unit 505 calculates the integrated value of the charge / discharge current being adjusted by integrating the detection current of the current sensor 300 during the capacity adjustment. Then, the control unit 505 can calculate the adjustment capacity from the integrated value and the set resistance value.

  As the battery pack 100 gradually deteriorates with time, the voltage difference between the cells C1 to CN increases, and the adjustment capacity also increases. In addition, when a micro short circuit occurs, a voltage drop occurs in the single cell in which the micro short circuit has occurred, the voltage difference between the single cells C1 to CN is further increased, and the adjustment capacity after the micro short circuit is further increased. In the operation period and the rest period similar to those in FIG. 3, when a micro short circuit occurs during the rest period, the transition of the number of adjustments with respect to time shows the same characteristics as in FIG. 3.

  Therefore, among the abnormality determination control of the assembled battery 100 by the battery controller 500 described above, the abnormality of the assembled battery 100 due to a minute short circuit can be detected even if the adjustment capacity is used by replacing the adjustment time with the adjustment capacity. Can do.

  In this example, the abnormality determination unit 506 may perform abnormality determination of the assembled battery 100 due to a micro short circuit, with the change amount of the adjustment time before and after the pause time as the change amount per unit time. The amount of change per unit time is calculated by dividing the time of the pause period from the amount of change (ΔA). The determination threshold (Ac) may be a threshold corresponding to the amount of change per unit time. Thereby, this example can detect the variation | change_quantity of the adjustment time per unit time during an idle period, and can detect the abnormality of the assembled battery 100 by a micro short circuit accurately.

  The voltage detector 501 corresponds to the “voltage detector” of the present invention, the capacity adjuster 504 is the “capacity adjuster” of the present invention, the predictor 507 is the “predicted value calculator”, and the calculator 508 is In the “calculation unit”, the abnormality determination unit 506 corresponds to the “determination unit”, the notification unit 509 corresponds to the “notification unit”, and the communication unit 510 corresponds to the “communication unit”.

<< Second Embodiment >>
FIG. 5 is a graph showing the characteristics of the adjustment time with respect to time in the battery pack control apparatus according to another embodiment of the invention. In this example, part of the abnormality determination control of the battery pack 100 is different from the first embodiment described above. Since the configuration other than this is the same as that of the first embodiment described above, the description thereof is incorporated as appropriate.

  The abnormality determination unit 506 sets a determination threshold (Ac) according to the length of the suspension period, and sets the determination threshold (Ac) so that the determination threshold (Ac) increases as the suspension period becomes longer.

As shown in FIG. 5, when the suspension period is Δt ₁ , the change amount of the adjustment time before and after the suspension period is ΔA ₁ , but when the suspension period is Δt ₂ (> Δt ₁ ). The change amount of the adjustment time before and after the suspension period is ΔA ₂ , and the change amount (ΔA ₂ ) is longer than the change amount (ΔA ₁ ). That is, when the pause period is long, the voltage drop due to the minute short circuit becomes large, so that the adjustment time during reactivation becomes long. Therefore, in this example, the determination threshold (Ac) is set according to the length of the suspension period.

  When the suspension period becomes long, the voltage difference between the cells C1 to CN increases due to the deterioration of the assembled battery 100 even when the micro short circuit does not occur during the suspension period. Therefore, at the time of re-operation after a long suspension period, the adjustment time becomes long and the amount of change (ΔA) before and after the suspension period increases. When the determination threshold value (Ac) is set to a fixed value and the change amount (ΔA) before and after the long pause period is larger than the determination threshold value (Ac), the abnormality determination unit 506 adjusts the adjustment time due to long-term deterioration. May be erroneously determined as an abnormality of the assembled battery 100 due to a micro short circuit.

  On the other hand, in this example, when restarting after a long suspension period, the determination threshold (Ac) is set to a large value, so that the amount of change (ΔA) before and after the long suspension period is the determination threshold (Ac). The abnormality determination unit 506 does not erroneously change the adjustment time due to long-term deterioration and does not determine that the assembled battery 100 is abnormal due to a micro short circuit.

  Next, the control procedure of the battery controller will be described with reference to FIG. FIG. 6 is a flowchart showing a control procedure of the battery controller 500. Note that the control loop shown in FIG. 6 is repeated if it is determined that the assembled battery 100 is normal. The control contents in steps S1 to S7 in FIG. 6 are the same as the control contents in steps S1 to S7 in FIG. Moreover, since the control content of step S81 of FIG. 6, step S82, and step S84-step S87 is the same content as step S71 of FIG. 4, respectively, description is abbreviate | omitted.

  After step S82, in step S83, the abnormality determination unit 506 sets a determination threshold (Ac) according to the length of the suspension period, and proceeds to step S84.

  As described above, in this example, the abnormality determination unit 506 sets a determination threshold according to the length of the suspension period. Thereby, abnormality of the assembled battery 100 by a micro short circuit can be detected accurately.

  In this example, the abnormality determination unit 506 sets a determination threshold (Ac) according to the length of the use period of the assembled battery 100, and the determination threshold (Ac) increases as the use period of the assembled battery 100 increases. The determination threshold value (Ac) may be set so that When the use period of the assembled battery 100 is long, the deterioration degree of the assembled battery 100 is high, and the variation in the voltage difference between the single cells C1 to CN becomes large.

FIG. 7 is a graph showing characteristics of the adjustment time with respect to time in the battery pack control apparatus according to the variation of the present invention. Graph a shows the characteristics when the assembled battery 100 is used for a short time, and graph b shows the characteristics when the assembled battery 100 is used for a long time. As shown in FIG. 7, even when the rest period is the same, the assembled battery 100 having a long use period has a high degree of deterioration. Therefore, the amount of change (ΔA ₂ ) of the assembled battery 100 having a long use period is a set having a short use period. It becomes larger than the change amount (ΔA ₁ ) of the battery 100. Therefore, in this example, by setting the determination threshold (Ac) according to the length of the use period of the assembled battery 100, it is possible to accurately detect an abnormality in the assembled battery 100 due to a minute short circuit.

  In this example, the abnormality determination unit 506 may set a determination threshold value using information related to the other assembled battery 100 received by the communication unit 510. For example, in another vehicle, data relating to the assembled battery 100 has already been acquired and accumulated in a database of a center that manages the other vehicle, and a change in adjustment time when a short-circuit occurs in the assembled battery 100 of another vehicle. The amount is also stored in the center as past data. When using the assembled battery 100 in the host vehicle, the control unit 505 receives information regarding the amount of change in the adjustment time when a micro short circuit occurs via the communication unit 510. Then, the abnormality detection unit 506 sets a determination threshold (Ac) from the information received by the communication unit 510.

  As a result, in this example, the determination threshold value can be set using not only the data of the assembled battery 100 of the own vehicle but also the data of the assembled battery 100 of the other vehicle. Can be detected well.

DESCRIPTION OF SYMBOLS 100 ... Assembly battery C1-CN, Cp ... Single cell 102 ... Temperature sensor 200 ... Load 300 ... Current sensor 400 ... Capacity adjustment circuit 401 ... Resistance 402 ... Switch 500 ... Battery controller 501 ... Voltage detection part 502 ... Current detection part 503 ... Battery temperature detection unit 504 ... Capacity adjustment unit 505 ... Control unit 506 ... Abnormality determination unit 507 ... Storage unit 508 ... Calculation unit 509 ... Notification unit 510 ... Communication unit

Claims (6)

An assembled battery control device comprising an assembled battery including a plurality of single cells,
Adjusting means for adjusting the voltage or state of charge of the plurality of single cells to a predetermined target value;
Adjustment time actually required until the voltage or state of charge of the plurality of single cells is adjusted to the target value using the adjustment means, or the number of adjustments per unit time actually adjusted using the adjustment means Or a calculation means for calculating the adjustment capacity actually adjusted using the adjustment means;
Storage means for storing a calculated value calculated by the calculating means;
Determination means for determining an abnormality caused by a short circuit in the assembled battery from the slope of the calculated value and the amount of change of the calculated value arranged in time series using the calculated value stored in the storage means; ,
The determination means includes
The difference between the slope before the pause period of the control device and the slope after the pause period is within a predetermined range, and the amount of change before and after the pause period is greater than a threshold indicating a micro short circuit. In this case, it is determined that an abnormality of the assembled battery is caused by a minute short circuit in the assembled battery. The assembled battery control device according to claim 1, wherein the determination unit sets the threshold according to a length of the suspension period. 3. The assembled battery control device according to claim 1, wherein the determination unit sets the threshold according to a usage period of the assembled battery. Voltage detection means for detecting voltage values of the plurality of single cells,
The adjusting means includes
Having a capacity adjusting resistor and a switch connected to the unit cell;
The assembled battery according to any one of claims 1 to 3, wherein the switch is turned on to adjust the capacity of the unit cell based on a voltage difference between the voltage values of the plurality of unit cells. Control device. It further includes a communication unit that communicates with the outside,
The determination means includes
The assembled battery control device according to any one of claims 1 to 4, wherein the threshold is set using information on the assembled battery received by the communication unit. The assembled battery control device according to any one of claims 1 to 5, further comprising notification means for notifying the abnormality of the assembled battery.

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