JP2010273413A - Device for controlling battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for controlling battery packs, capable of accurately controlling charging or discharging. <P>SOLUTION: The device includes: a full charge capacity detection means 31 for detecting a full charge capacity of each electric cell with respect to a battery pack 2 in which multiple electric cells 2a and 2b as secondary batteries are connected together; a selection means 32 for selecting a specific electric cell from among the electric cells, based on the full charge capacity of each electric cell; a first internal state decision means 33 for computing the internal state characteristic of the specific electric cell, based on the full charge capacity of the specific electric cell and determining the internal state characteristic of the specific electric cell as the internal state characteristic of the battery pack; and a computing means 36 for computing electric energy that is input or output to or from the battery pack, based on the internal state characteristic of the battery pack. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  A battery pack charge / discharge control method for executing battery pack charge / discharge control based on a battery having the smallest remaining capacity for each battery in a battery pack formed by connecting a plurality of battery cells (cells) is known. (Patent Document 1).

JP 2003-244860 A

  In the above prior art, the full charge capacity of the unit cell is treated as an invariable value, and charge / discharge control is performed according to the unit cell with a small remaining capacity, but the actual unit cell has a full charge capacity value due to deterioration over time etc. Fluctuates. For this reason, there has been a problem that accurate charge / discharge control cannot be performed due to inadvertent overcharge or overdischarge, or variation in the state of charge (SOC).

The problem to be solved by the present invention is to provide a control device for an assembled battery that can accurately control charging or discharging.

  The present invention first detects the full charge capacity of a single cell, selects a specific single cell from the plurality of single cells based on the detected full charge capacity, and based on the full charge capacity of the selected single cell. The internal state characteristics of the unit cell are calculated. And by determining the internal state characteristics of this specific cell as the internal state characteristics of the assembled battery, and further calculating the amount of power that can be input to or output from the assembled battery based on the internal state characteristics of the assembled battery, Solve the problem.

  According to the present invention, the amount of electric power that can be input to or output from the battery pack is calculated according to the internal state characteristics of the battery pack detected based on the full charge capacity of the specific battery cell. Even if the capacity varies, the charging or discharging control for the assembled battery can be executed accurately.

It is a block diagram which shows the assembled battery system to which one embodiment of this invention is applied. It is a graph which shows an example of the acquisition method of the open circuit voltage of a battery. It is a graph which shows an example of the method of calculating charge condition SOC from the open circuit voltage of a battery. 3 is a graph for explaining a determination criterion X1 in the switching circuit 35 of FIG. 3 is a graph for explaining a determination criterion X2 in the switching circuit 35 of FIG. It is a flowchart which shows the control procedure of the control apparatus 3 of FIG. It is a graph which shows the calculation result of the electric energy which can be input (charge) with respect to the current integration capacity about an example and a comparative example. It is a graph which shows the calculation result of the output (discharge) electric energy with respect to the current integration capacity about an Example and a comparative example. It is a flowchart which shows the other example of the control procedure of the control apparatus 3 of FIG. 6 is a flowchart showing still another example of the control procedure of the control device 3 of FIG. 1.

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

<< First Embodiment >>
FIG. 1 is a block diagram showing an assembled battery system to which an embodiment of the present invention is applied. For example, a drive motor mounted in an electric vehicle or a hybrid vehicle is a battery load 1, and this motor is used as electric power of the assembled battery 2. The assembled battery system that performs power running operation or regenerates the motor and charges the assembled battery with the generated power will be described. However, the battery load of the assembled battery control device of the present invention can be widely applied to electric drive devices other than motors for automobiles.

  The battery load 1 is driven and controlled by a load controller 11 such as a motor controller, and drives the battery load 1 in response to a load driving request input from the outside. At this time, power supply operation of the battery load 1 is controlled by receiving supply of discharge power from the battery pack 2, or regenerative operation of the battery load 1 is controlled to charge the battery pack 2 with the generated power.

  When the battery load 1 is an AC drive load, an inverter that converts the DC power of the battery pack 2 into AC power is provided between the battery pack 2 and the battery load 1, and the battery load 1 is a DC drive load. In this case, a DC / DC converter is provided between the assembled battery 2 and the battery load 1, but the illustration thereof is omitted in FIG.

  The assembled battery 2 of this example is a DC battery formed by connecting a plurality of unit cells 2a and 2b, which are secondary batteries, in series and / or in parallel. In the specific example shown in FIG. An example in which the battery pack 2 is configured by connecting batteries 2a and 2b in series is shown. The bipolar terminals of the assembled battery 2 are respectively connected to the input / output terminals of the battery load 1, whereby when the battery load 1 is in a power running operation, the power from the assembled battery 2 is discharged to the battery load 1, while the battery load 1 When the regenerative operation is performed, the assembled battery 2 is charged with the generated power from the battery load 1.

  The battery pack control device 3 of this example includes voltage sensors 311a and 311b that detect the voltages of the single cells 2a and 2b, and a current sensor that detects current flowing in the main circuit between the battery pack 2 and the battery load 1. 312, a voltage sensor 341 that detects the total voltage of the assembled battery 2, a full charge capacity detection circuit 31, a selection circuit 32, a first internal state determination circuit 33, a second internal state determination circuit 34, and a switching circuit 35 and a calculation circuit 36.

  The voltage sensors 311a and 311b are connected so as to detect the voltage between both terminals of each single cell 2a and 2b, and the detection signal is output to the full charge capacity detection circuit 31. The voltage sensor 341 detects a voltage between both terminals of the assembled battery 2, that is, a voltage between one terminal of the unit cell 2a constituting the assembled battery 2 and the other terminal of the unit cell 2b. The detection signal is output to the second internal state determination circuit 34.

  The current sensor 312 is connected to the main circuit of the assembled battery 2, and the detection signal is output to the full charge capacity detection circuit 31 and the second internal state determination circuit 34.

  The full charge capacity detection circuit 31, the selection circuit 32, the first internal state determination circuit 33, the second internal state determination circuit 34, the switching circuit 35, and the calculation circuit 36 are an arithmetic unit such as a CPU or MPU in which an arithmetic program is incorporated. Or a peripheral electronic circuit. Note that these circuits 31 to 36 are merely separated for convenience in order to facilitate understanding of the contents of the arithmetic processing in this example, and therefore, a plurality of circuits may be configured as one circuit. In short, the control device 3 as a whole only needs to have the following functions, and each of the circuits does not need to exhibit each of the following functions in a strict sense.

The full charge capacity detection circuit 31 detects the full charge capacity of each of the single cells 2 a and 2 b constituting the assembled battery 2. The full charge capacity here is the battery capacity Ah when the state of charge SOC is 100%, and is a characteristic representing the internal state of the battery that varies depending on the degree of deterioration of the unit cell. The full charge capacity _Qmax can be detected by various methods, and an example is shown here.

  That is, when the unit cell to be measured is charged or discharged from time ta to tb, the open state voltage Va, Vb is measured for the charge state SOCa before the start of charge or discharge and the charge state SOCb at the end of charge or discharge. To calculate. On the other hand, the current I flowing through the cell at the time of charging or discharging is definitely integrated from time ta to tb, and the charge capacity or discharge capacity (∫I (t) dt, where the left integral is the definite integral from time ta to tb. )) Is calculated.

Since the change in the state of charge (SOCb-SOCa) due to charging or discharging is caused by charging or discharging performed on the unit cell, the charging capacity or discharging capacity that is the time integrated value of the flowing current is calculated. The value divided by the change in the state of charge is the battery capacity when the state of charge SOC = 100%, that is, the full charge capacity _Qmax .

[Formula 1]
Q _max = ∫I (t) dt / (SOCb−SOCa)
The numerator on the right side is a definite integral from time ta to tb.

  Incidentally, the state of charge SOC can be obtained from the open voltage of the single cells 2a and 2b and the open voltage-SOC map. That is, the open circuit voltage here is 1) an open circuit voltage V1 obtained by actual measurement when the unit cell is in an unloaded state, and 1) an IV obtained from a current value and a voltage value sampled at the time of charge / discharge. Extrapolation of characteristics, that is, open-circuit voltage V2 estimated by power calculation, or 3) open-circuit voltage V3 = (total voltage) + (current value) × (current value and total voltage value actually measured during charge / discharge Any of the open-circuit voltage V3 estimated by the temperature and the deterioration-corrected internal resistance) can be adopted.

  Since the measurement of the open circuit voltage of 1) is performed when there is no load, it can be measured at the time of no load when starting the automobile (before turning on the high power system) or when the key is turned off. On the other hand, since the open voltage of 2) and 3) can be measured even when there is no load, the open voltage is acquired by appropriately selecting them.

  As an example, the procedure for obtaining the open circuit voltage V2 in 2) above will be described. FIG. 2 is a graph showing an example of a method for obtaining the open circuit voltage of the battery, and FIG. 3 is a graph showing an example of a method for calculating the state of charge SOC from the open circuit voltage of the battery.

  This open circuit voltage V2 captures changes in the current of the cells 2a and 2b when the vehicle is running, and the current value I and the voltage value V as shown in FIG. 2, and the current sensor 312 and voltage sensor 311a, Multiple sampling is performed using 311b. The circles x in the figure are the measured sampling points, and the characteristic straight line L (= R · I + V2) is obtained by performing linear regression calculation on the IV data sampling data in the IV coordinates. The intersection of the characteristic line L and the vertical axis (voltage axis) is the open circuit voltage V2. The open circuit voltage Va at the start of charging or discharging described above and the open circuit voltage Vb at the end of charging or discharging are obtained.

  The correlation between the open-circuit voltage of the cell and the state of charge SOC is unchanged even if the temperature or the degree of deterioration of the cell changes. FIG. 3 is a graph showing the correlation between the open-circuit voltage of the single cell and the SOC, and this map is stored in the memory area of the control device 3 for each of the single cells 2a and 2b. Then, the charging states SOCa and SOCb are obtained from the open circuit voltages Va and Vb obtained by the linear regression calculation shown in FIG. 2 with reference to the open circuit voltage-SOC map shown in FIG.

  In addition to the above formula 1, the full charge capacity can also be obtained, for example, by dividing the current I flowing through the single cell by the time differential value d (SOC) / dt of the charged state (for example, JP No. 2006-292492), and the calculation method is not limited at all.

Returning to FIG. 1, the selection circuit 32 selects a specific single cell from the plurality of single cells 2 a and 2 b based on the full charge capacity Q _max of each single cell 2 a and 2 b detected by the full charge detection circuit 31. . In this example, a single cell having a minimum full charge capacity _Qmax is selected. For example, when the full charge capacity of the single battery 2a is smaller than the full charge capacity of the single battery 2b, the single battery 2a is selected. In addition to selecting a single cell having the minimum full charge capacity, for example, a plurality of single cells having the minimum full charge capacity may be selected and the average value thereof may be used instead.

  The first internal state determination circuit 33 is based on the full charge capacity of the specific single battery selected by the selection circuit 32, that is, the single battery 2a having the minimum full charge capacity in this example. The internal state characteristic is calculated, and the minimum internal state characteristic of the cell 2 a is determined as the internal state characteristic of the assembled battery 2.

As the internal state characteristics of the unit cell, the state of charge SOC, the remaining capacity, the consumed capacity or the open circuit voltage of the unit cell can be adopted. The open circuit voltage of the unit cell can be obtained by the primary regression calculation of IV sampling shown in FIG. 2, and if the open circuit voltage is obtained, the SOC can be obtained from the correlation diagram shown in FIG. Further, the remaining capacity of the unit cell can be calculated by multiplying the full charge capacity Q _max obtained by the full charge capacity detection circuit 31 by the state of charge SOC obtained from the open voltage V via a map. Further, the consumed capacity of the unit cell can be calculated by subtracting the remaining capacity from the full charge capacity _Qmax .

The determination of the internal state characteristics of the assembled battery means that what characteristic value is representatively used to calculate the input / output possible electric energy of the assembled battery 2 calculated by the calculation circuit 36 described later. is there. In this example, the internal state characteristics such as the state of charge SOC, the remaining capacity, the consumed capacity, or the open voltage calculated based on the full charge capacity Q _max of the single battery 2a having the minimum full charge capacity Q _max are represented by the assembled battery 2. The internal state characteristics are set and output to the calculation circuit 36 via the switching circuit 35.

  On the other hand, the second internal state determination circuit 34 determines the internal state characteristics of the entire assembled battery by regarding the assembled battery 2 as one single cell. In this example, the charge state SOC of the assembled battery 2 is acquired in the same manner as described in the description of the full charge capacity detection circuit 31 as the calculation method of the charge state SOC from the acquisition of the open circuit voltage. Then, the state of charge SOC is set as an internal state characteristic of the entire assembled battery, and is output to the calculation circuit 36 via the switching circuit 35.

Thus, state of charge SOC of the full charge capacity by the first internal state determining circuit 33 is calculated based on the full charge capacity Q _max of the smallest unit cell 2a, the remaining capacity, the internal state such capacity consumed or open circuit voltage While the characteristic is output as the internal state characteristic of the assembled battery 2, the second internal state determination circuit 34 outputs the state of charge SOC of the entire assembled battery obtained by regarding the assembled battery 2 as one unit cell.

The switching circuit 35 outputs the internal state characteristic of the assembled battery 2 to be output to the calculation circuit 36 at the subsequent stage, either the internal state characteristic by the first internal state determination circuit 33 or the internal state characteristic by the second internal state determination circuit 34. Switch to one. In this example, when the state of charge SOC of the entire assembled battery 2 obtained by the second internal state determination circuit 34 is within a predetermined range X1% to X2%, the internal state characteristics by the second internal state determination circuit 34, that is, the set Switching is performed so that the state of charge SOC of the entire battery 2 is output to the calculation circuit 36. On the contrary, when the state of charge SOC of the entire assembled battery 2 is less than X1% or exceeds X2%, the internal state characteristics by the first internal state determination circuit 33, that is, the single battery 2a having the minimum full charge capacity The internal state characteristics such as the state of charge SOC, remaining capacity, consumed capacity, or open voltage calculated based on the full charge capacity Q _max are output to the calculation circuit 36.

  Here, the state of charge SOC = X1 and X2 of the assembled battery, which is a determination criterion, is set as follows. FIG. 4A is a graph for explaining a setting method of the determination criterion X1 in the switching circuit 35, and FIG. 4B is a graph for similarly explaining a setting method of the determination criterion X2.

  As a premise, the average battery capacity (full charge capacity) C2 of the entire assembled battery 2 in the state of charge SOC = 100% and the battery capacity (full charge capacity) C2a of the unit cell 2a in the same state of charge SOC = 100% It is assumed that C2> C2a as shown in the right diagram of FIG. 4A due to deterioration of 2a and the like.

When the full charge capacity C2a of the unit cell 2a constituting the assembled battery 2 is smaller than the average full charge capacity C2 of the assembled battery 2 as a whole, when discharging starts from the charged state SOC = 100%, as shown in the left diagram of FIG. 4A. The single cell 2a reaches the lower limit SOC _min earlier.

However, there is a problem when the unit cell 2a reaches the lower limit SOC _min (SOC = Xmin), but until a little before the lower limit SOC _min , that is, until the charged state SOC = X1 of the entire assembled battery 2 in FIG. As for the interval, even if the SOC of the entire assembled battery 2 is controlled as the internal state characteristic or the SOC of the single battery 2a is controlled as the internal state characteristic, problems such as overdischarge of the single battery do not occur. In this example, from this point of view, the charging state SOC = X1 obtained by adding the safety allowance to the charging state SOC = Xmin of the assembled battery when the unit cell 2a reaches the lower limit SOC _min is set as the lower limit X1 of the reference range.

Similarly, when charging is started from the charged state SOC = 0% when the full charge capacity C2a of the single battery 2a constituting the assembled battery 2 is smaller than the full charge capacity C2 of the entire assembled battery 2, as shown in FIG. 4B. The unit cell 2a reaches the upper limit SOC ₁₀₀ earlier.

However, there is a problem if the unit cell 2a reaches the upper limit SOC ₁₀₀ (SOC = Xmax), but until a little before the upper limit SOC ₁₀₀ , that is, the state of charge of the entire assembled battery 2 in FIG. Even if the SOC of the entire battery pack 2 is controlled as an internal state characteristic or the SOC of the single battery 2a is controlled as an internal state characteristic, problems such as overcharging of the single battery do not occur. In this example, from this point of view, the charging state SOC = X2 obtained by subtracting the safety allowance from the charging state SOC = Xmax of the battery pack when the unit cell 2a reaches the upper limit SOC ₁₀₀ is set as the upper limit X2 of the reference range.

  Note that the method of setting the determination criteria X1 and X2 is not limited to the specific example described above, and may be set based on empirical or design ideas.

  The calculation circuit 36 calculates the amount of electric power that can be output from the assembled battery 2 in response to the discharge request from the load controller 11 based on the internal state characteristics of the assembled battery input via the switching circuit 35, and the load In response to a charging request from the controller 11, the amount of power that can be input to the battery pack 2 is calculated. The calculated electric energy is output to the load controller 11, and the load controller 11 controls the battery load 1 according to the received input / output possible electric energy of the assembled battery.

  Next, the control procedure will be described.

  FIG. 5 is a flowchart showing the control procedure of the battery pack control device 3 of this example.

  First, in step S1, the assembled battery is regarded as one unit cell, and the open voltage of the entire assembled battery 2 is acquired. This process is executed by the second internal state determination circuit 34. As already described with reference to FIG. 2, the current sensor 312 acquires the current that flows from the start of charge / discharge until the end of charge / discharge, and both ends of the assembled battery 2 The voltage is acquired by the voltage sensor 341. Then, the sampled current and voltage are plotted as an IV characteristic as shown in FIG. 2, and the open circuit voltage V2 is calculated by linear regression calculation.

  In step S2, an open-circuit voltage-SOC map of the assembled battery as shown in FIG. 3 is stored in the memory area of the control device 3, and the open-circuit voltage V2 obtained in step S1 and the state of charge of the assembled battery 2 are determined from this map. Calculate the SOC.

  In step S3, it is determined whether or not the state of charge SOC of the assembled battery 2 obtained in step S2 is in the range of X1 to X2. If it is within this range, the process proceeds to step S7, and the second internal state determination circuit The charge state SOC of the entire assembled battery 2 obtained at 34 is output to the calculation circuit 36 via the switching circuit 35.

  As described above with reference to FIGS. 4A and 4B, when the charging state of the entire assembled battery 2 is X1 ≦ SOC ≦ X2, it may exceed both the internal state characteristics of the unit cell 2a and the charging state of the entire assembled battery 2. Since the problem of discharge or overcharge does not occur, the state of charge SOC of the assembled battery with a small calculation load is output to the calculation circuit 36.

  In step S7, the calculation circuit 36 calculates the electric energy that can be discharged from the assembled battery 2 and the electric energy that can be charged in the assembled battery 2 based on the input SOC of the entire assembled battery 2, and the process proceeds to step S8. The electric energy is output to the load controller 11. Receiving this, the load controller 11 controls the battery load 1 based on the chargeable / dischargeable electric energy.

  On the other hand, when the state of charge SOC of the assembled battery 2 obtained in step S2 is not in the range of X1 to X2, but is less than X1 or exceeds X2, the process proceeds to step S4.

In step S4, the full charge capacity detection circuit 31 detects the full charge capacity of each single cell 2a, 2b. As described above with reference to FIG. 2 and FIG. 3, this full charge capacity Q _max is detected by obtaining the open-circuit voltages Va and Vb from the plot of the IV characteristic, and obtaining the charge states SOCa and SOCb from the open-circuit voltage. This charge state change SOCb-SOCa and the time integrated value ∫I (t) dt of the flowing current can be obtained based on the above equation 1.

  In step S5, the full charge capacities of the single cells 2a and 2b detected in step S4 are compared, and the single battery (2a in this example) having the minimum full charge capacity is selected by the selection circuit 32. Then, in the first internal state determination circuit 33, based on the full charge capacity of the selected unit cell 2a, internal state characteristics such as the charge state SOC, the remaining capacity, the consumed capacity or the open voltage are calculated, and this is used as the assembled battery. Is output to the calculation circuit 36 via the switching circuit 35.

  In step S6, in the calculation circuit 36, based on the internal state characteristics such as the state of charge SOC, the remaining capacity, the consumed capacity or the open circuit voltage of the unit cell 2a selected in step S5, The amount of power that can be charged in the battery 2 is calculated, the process proceeds to step S8, and this amount of power is output to the load controller 11. Receiving this, the load controller 11 controls the battery load 1 based on the chargeable / dischargeable electric energy.

As described above, according to the battery pack control device of the present embodiment, when calculating the input / output possible electric energy for the battery load 1, not the state of charge SOC of the single cells 2a and 2b and the battery pack 2, but full charge. Since the calculation is made based on the full charge capacity Q _max of the single battery 2a having a small capacity Q _max , even if the full charge capacity of the single battery varies due to deterioration with time or the like, it is possible to perform accurate control accordingly. Thereby, overcharge and overdischarge can be prevented, and the capacity variation of the unit cell can be suppressed.

  In addition, in the range X1 to X2 in which the influence due to the small full charge capacity of the unit cell is small, the input / output possible electric energy is calculated based on the state of charge SOC of the entire assembled battery 2, so The calculation load due to the calculation of the capacity can be reduced. Further, it is possible to prevent unnecessary output restriction from being output to the battery load 1.

  In the present embodiment, the second internal state determination circuit 34 and the switching circuit 35 shown in FIG. 1 are omitted, and steps S1 to S3 and S7 in FIG. The calculation may be performed based only on the minimum full charge capacity of the unit cell 2a.

  The solid line in FIG. 6 shows an example of calculating the input (chargeable) power amount with respect to the current integrated amount based on the minimum full charge capacity, and the dotted line in FIG. 6 shows the current integrated amount based on the charge capacity SOC of the entire assembled battery 2. The example which calculated the electric energy which can be input (charge) with respect to is shown. In addition, the solid line in FIG. 7 shows an example in which the output (discharge) possible electric energy with respect to the accumulated current amount is calculated based on the minimum full charge capacity, and the dotted line in the same figure shows the current based on the charge capacity SOC of the entire assembled battery 2. The example which calculated the electric power amount which can be output (discharged) with respect to an integrated amount is shown.

  In any case, accurate control according to the variation in the full charge capacity of the unit cell due to deterioration over time, etc. is possible, thereby preventing overcharge and overdischarge and suppressing variation in unit cell capacity. Can do.

<< Second Embodiment >>
FIG. 8 is a flowchart showing another example of the control procedure of the battery pack control device 3 of FIG. The control procedure of this example is different from the procedure of the first embodiment shown in FIG. 5 in steps S2A and S3A, and the other procedures are the same. For this reason, the same step code | symbol as FIG. 5 is attached | subjected to FIG. 8, and the description regarding the description is used for this example.

  The configuration of the battery pack control device 3 of this example is the same as that of the block diagram of the first embodiment shown in FIG. 1, but the processing contents in the switching circuit 35 and the second internal state determination circuit 34 are different. The other configurations are the same. For this reason, suppose that the description regarding the description is used for this example, and a difference is demonstrated below.

  In step S2A of FIG. 8, based on the state of charge SOC of the assembled battery calculated in step S2, the amount of input (chargeable) energy and the amount of output (dischargeable) energy when the assembled battery is regarded as one unit cell. Is calculated. This input / output possible electric energy can be calculated, for example, by multiplying the state of charge SOC by the initial battery capacity or multiplying it by a temperature correction coefficient.

  In step S3A, it is determined whether the input / output possible electric energy calculated in step S2A is greater than or equal to a preset reference value P1, and if it is greater than or equal to P1, the process proceeds to step S7 and the SOC of the entire assembled battery 2 is calculated. Use internal state characteristics. On the other hand, when it is less than P1, it progresses to step S4, the full charge capacity of the cell 2a, 2b is calculated, and the input / output possible electric energy based on this is calculated.

  Thus, even if the internal state characteristics are switched depending on the input / output possible electric energy of the assembled battery, the same operational effects as those of the first embodiment described above are obtained.

<< Third Embodiment >>
FIG. 9 is a flowchart showing still another example of the control procedure of the battery pack control device 3 of FIG. The control procedure of this example is different from the procedure of the first embodiment shown in FIG. 5 in the processing content of step S3 and the order of steps S1 to S4, and the other procedures are the same. For this reason, the same step code | symbol as FIG. 5 is attached | subjected to FIG. 9, and the description regarding the description is used for this example.

  Further, the configuration of the battery pack control device 3 of this example is the same as the block diagram of the first embodiment shown in FIG. 1, but the processing contents in the switching circuit 35 are different, and the other configurations are the same. is there. For this reason, suppose that the description regarding the description is used for this example, and a difference is demonstrated below.

First, in step S4 in FIG. 9, the same processing as in step S4 in FIG. 5 is executed to detect the full charge capacity Q _max of each single cell 2a, 2b.

  In step S3B, it is determined whether or not the variation in the full charge capacity of the single cells 2a and 2b detected in step S4 is equal to or less than a preset reference value α (Ah). If it is equal to or less than α, steps S1 to S2 are performed. → Proceeding to S7, the SOC of the entire assembled battery 2 is set as the internal state characteristic.

  On the other hand, if the variation in the full charge capacity of the single cells exceeds α (Ah), the process proceeds to step S5, and the single cell with the minimum full charge capacity detected in step S4 is selected. In steps S6 and S8, an input / output possible electric energy based on the minimum full charge capacity is calculated.

  Thus, even if the internal state characteristics are switched depending on the magnitude of the variation in the full charge capacity of the unit cells, the same effects as those of the first embodiment described above can be obtained.

  In this example, in step S3B, the variation in the full charge capacity of the cells is used as a reference for switching the internal state characteristics. Instead, the remaining capacity of the cells is compared with a preset reference value β. Alternatively, the internal state characteristics may be switched by comparing the variation in open-circuit voltage of the unit cell with a preset reference value γ.

  The full charge capacity detection circuit 31 corresponds to a full charge detection means according to the present invention, the selection circuit 32 corresponds to a selection means according to the present invention, and the first internal state determination circuit 33 corresponds to a first charge according to the present invention. The second internal state determination circuit 34 corresponds to the second internal state determination unit according to the present invention, the switching circuit 35 corresponds to the switching unit according to the present invention, and the calculation is performed. The circuit 36 corresponds to calculation means according to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Battery load 11 ... Load controller 2 ... Assembly battery 2a, 2b ... Single battery 3 ... Control apparatus 31 ... Full-charge capacity detection circuit 311a, 311b ... Voltage sensor 312 ... Current sensor 32 ... Selection circuit 33 ... 1st internal state determination Circuit 34 ... Second internal state determination circuit 341 ... Voltage sensor 35 ... Switching circuit 36 ... Calculation circuit

Claims (9)

A full charge capacity detecting means for detecting a full charge capacity of the single battery with respect to an assembled battery to which a plurality of single batteries as secondary batteries are connected;
Selection means for selecting a specific unit cell from the plurality of unit cells based on the full charge capacity of the unit cell;
The internal state characteristic of the specific cell is calculated based on the full charge capacity of the specific cell, and the internal state characteristic of the specific cell is determined as the internal state characteristic of the assembled battery A determination means;
An assembled battery control device comprising: a calculating unit that calculates an amount of electric power that can be input to or output from the assembled battery based on an internal state characteristic of the assembled battery. In the assembled battery control device according to claim 1,
A second internal state determination means for determining the internal state characteristics of the entire assembled battery by regarding the assembled battery as one single cell;
Switching means for switching the internal state characteristic of the assembled battery to be output to the calculating means to one of the internal state characteristics of the assembled battery detected by the first internal state determining means and the second internal state determining means, respectively. And an assembled battery control device. The control apparatus for an assembled battery according to claim 1 or 2,
The selection unit is a control apparatus for a battery pack that selects a single cell having a minimum full charge capacity among the plurality of single cells based on the full charge capacity of the single cell detected by the full charge capacity detection unit. In the control apparatus of the assembled battery as described in any one of Claims 1-3,
The control device for a battery pack in which the internal state characteristic of the specific cell is any of SOC, remaining capacity, consumed capacity, or open voltage of the cell. In the control apparatus of the assembled battery as described in any one of Claims 2-4,
The second internal state determination means detects the SOC of the assembled battery when the assembled battery is regarded as one unit cell,
When the SOC of the assembled battery detected by the second internal state determining unit is within a predetermined range X1 to X2, the switching unit determines the internal state characteristic of the assembled battery determined by the second internal state determining unit. Is a control device for an assembled battery. In the control apparatus of the assembled battery as described in any one of Claims 2-4,
The second internal state determination means detects the input / output possible electric energy of the assembled battery when the assembled battery is regarded as one unit cell,
When the input / output possible electric energy of the assembled battery detected by the second internal state determining unit is greater than or equal to a predetermined value P1, the switching unit is configured to detect the internal state of the assembled battery determined by the second internal state determining unit. A battery pack control device for outputting state characteristics to the calculating means. In the control apparatus of the assembled battery as described in any one of Claims 2-4,
The switching means has an internal state characteristic of the assembled battery determined by the second internal state determination means when the variation of the full charge capacity of the single cells detected by the full charge capacity detection means is not more than a predetermined value α. Is a control device for an assembled battery. In the control apparatus of the assembled battery as described in any one of Claims 2-4,
The full charge capacity detecting means detects a remaining capacity of the unit cell,
The switching means determines the internal state characteristics of the assembled battery determined by the second internal state determination means when the variation in the remaining capacity of the single cells detected by the full charge capacity detection means is equal to or less than a predetermined value β. A battery pack control device for outputting to the calculation means. In the control apparatus of the assembled battery as described in any one of Claims 2-4,
The full charge capacity detection means detects an open voltage of the unit cell,
When the variation in the open-circuit voltage of the single cells detected by the full charge capacity detection unit is equal to or less than a predetermined value γ, the switching unit determines the internal state characteristics of the assembled battery determined by the second internal state determination unit. A battery pack control device for outputting to the calculation means.

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