JP2014102188A - Fully charged capacity estimation apparatus, fully charged capacity estimation method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate a battery capacity when the battery capacity of a secondary battery deteriorates.SOLUTION: An SOCI estimation section 105 estimates SOCIs of a secondary battery for respective values of fully charged capacities of the secondary battery, on the basis of a current value obtained by measuring current charged to and discharged from the secondary battery, and a plurality of candidate fully charged capacities which are candidates for the fully charged capacities of the secondary battery. An SOCV estimation section 102 estimates a charge rate on the basis of an open-circuit voltage of the secondary battery. A fully charged capacity estimation section 111 estimates that the fully charged capacity of the secondary battery is a candidate fully charged capacity used for estimating the SOCI having the smallest difference from the SOCV estimated by the SOCV estimation section 102 from among SOCIs estimated by the SOCI estimation section 105.

Description

  The present invention relates to a full charge capacity estimation device, a full charge capacity estimation method, and a program.

  In order to make maximum use of a secondary battery such as a lithium battery or a lead storage battery, it is necessary to accurately estimate the state of charge (SOC) of the secondary battery. By the way, the secondary battery deteriorates due to continuous use, the internal resistance increases due to the deterioration, and the full charge capacity decreases. One method for estimating the SOC of the secondary battery is to divide the integrated value of the current flowing into and out of the secondary battery by the full charge capacity. When the SOC is estimated using this method, Due to the error in capacity, the estimated SOC also reaches an error. In addition, as one of methods for estimating the SOC of the secondary battery, there is a method of estimating the SOC from the open voltage of the secondary battery. However, when the SOC is estimated using this method, the SOC is released due to an error in internal resistance. An error occurs in the estimated value of the voltage, and the error also reaches the estimated SOC.

  Therefore, Patent Document 1 discloses an invention for estimating the SOC in consideration of an error that may occur in the full charge capacity due to deterioration of the secondary battery. Thus, a value that can be estimated to be optimal can be determined as the current charging rate from the relationship between the SOC calculated based on the open circuit voltage and the range that can be taken as the charging rate that reflects the error of the current integrated value. .

  Patent Document 2 discloses an invention in which an error between the integrated value of the actual current and the integrated value of the estimated current is estimated, the capacity deterioration parameter is estimated so that the error becomes 0, and the SOC is calculated. It is disclosed. Thereby, the estimation precision of SOC can be improved.

International Publication No. 2011/104752 JP 2011-15520 A

However, Patent Document 1 describes a method for estimating the SOC in consideration of a battery capacity error and an estimation error, but does not describe a method for estimating the battery capacity when the battery capacity is deteriorated. On the other hand, Patent Document 2 describes a method for estimating a battery capacity when a battery is deteriorated. However, in the method described in Patent Document 2, since the battery capacity is estimated using the integrated value of the current, if an error is included in the measured value of the current value, the error is integrated. Accuracy may be reduced.
The objective of this invention is providing the full charge capacity estimation apparatus, the full charge capacity estimation method, and program which solve the subject mentioned above.

  The present invention has been made in order to solve the above-described problem. A current value measured from a current charged / discharged in a secondary battery and a plurality of candidate full charge candidates for the full charge capacity of the secondary battery. Based on the charge capacity, a current charge rate estimator for estimating the charge rate of the secondary battery when the full charge capacity of the secondary battery is a respective value, and based on the open voltage of the secondary battery The candidate used for estimation of the smallest difference between the charging rate estimated by the voltage charging rate estimation unit among the charging rates estimated by the voltage charging rate estimation unit and the current charging rate estimation unit A full charge capacity estimation device comprising: a full charge capacity estimation unit that estimates that the full charge capacity is a full charge capacity of the secondary battery.

  Further, in the present invention, the current charging rate estimation unit estimates a range that the charging rate of the secondary battery can take based on an error that may occur at the time of current measurement, and calculates a value within the range of the secondary battery. It is characterized by a charging rate.

  In the present invention, the current charging rate estimation unit compares the estimated range of the charging rate of the secondary battery with the charging rate estimated by the voltage charging rate estimation unit, and the voltage charging rate estimation unit When the estimated charging rate is a value within the range, the charging rate estimated by the voltage charging rate estimation unit is set as the charging rate of the secondary battery, and the charging rate estimated by the voltage charging rate estimation unit is When the charging rate estimated by the voltage charging rate estimator is larger than the maximum value of the range when the minimum value is smaller than the minimum value of the range, the minimum value is set as the charging rate of the secondary battery. The charging rate of the secondary battery is used.

  Further, in the present invention, the voltage charging rate estimation unit and the current charging rate estimation unit calculate charging rates at a plurality of times, and the full charge capacity estimation unit compares differences in charging rates at the plurality of times. Thus, the full charge capacity of the secondary battery is estimated.

  Further, in the present invention, the full charge capacity estimation unit uses the full charge capacity of the secondary battery as the full charge capacity used for estimating the charge rate at which the sum of squares of the charge rate differences at the plurality of times is minimized. It is estimated that there exists.

  In the present invention, the current charge rate estimation unit uses, as the candidate full charge capacity, a maximum value and a minimum value of a range that can be taken as a full charge capacity of the secondary battery, and a plurality of values within the range. Features.

  Further, in the present invention, the current charging rate estimation unit has a difference from the charging rate estimated by the voltage charging rate estimation unit among the charging rates estimated last time as a possible range of the full charge capacity of the secondary battery. A range from the maximum value to the minimum value of the candidate full charge capacity excluding the candidate full charge capacity used for estimation of the largest one is characterized.

  The present invention is also a method for estimating a full charge capacity of a secondary battery, wherein the current charge rate estimation unit includes a current value measured from a current charged and discharged to the secondary battery, and a full charge of the secondary battery. Based on a plurality of candidate full charge capacities that are candidates for capacity, the charge rate of the secondary battery when the full charge capacity of the secondary battery is each value is estimated, and the voltage charge rate estimation unit is The charge rate is estimated based on the open-circuit voltage of the secondary battery, and the full charge capacity estimation unit includes the charge rate estimated by the voltage charge rate estimation unit among the charge rates estimated by the current charge rate estimation unit, and It is estimated that the candidate full charge capacity used for estimation of the smallest difference is the full charge capacity of the secondary battery.

  Further, the present invention provides a computer based on a current value measured from a current charged and discharged to a secondary battery and a plurality of candidate full charge capacities that are candidates for the full charge capacity of the secondary battery. A current charge rate estimating unit for estimating a charge rate of the secondary battery when the full charge capacity of the secondary battery is a respective value; a voltage charge rate for estimating a charge rate based on an open voltage of the secondary battery Among the charging rates estimated by the estimation unit and the current charging rate estimation unit, the candidate full charge capacity used for estimation of the smallest difference from the charging rate estimated by the voltage charging rate estimation unit is the secondary battery This is a program for functioning as a full charge capacity estimation unit that estimates a full charge capacity.

  According to the present invention, the full charge capacity of the secondary battery is calculated based on the charging rate estimated based on the measured current value and the charging rate estimated based on the open circuit voltage. Thereby, even when the change of the full charge capacity occurs due to the deterioration of the secondary battery, the full charge capacity after the change can be estimated.

It is a schematic block diagram which shows the structure of the full charge capacity estimation apparatus by one Embodiment of this invention. It is a flowchart which shows operation | movement of the full charge capacity estimation apparatus by one Embodiment of this invention. It is a figure which shows the example of the equivalent circuit model of a secondary battery. It is a figure which compares the case where estimation of SOCI is performed using an electric current integrated value, and the case where estimation of SOCI is performed by this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic block diagram showing a configuration of a full charge capacity estimation apparatus 100 according to an embodiment of the present invention.
The full charge capacity estimation device 100 is a device that estimates the full charge capacity of a secondary battery in operation, and includes an open-circuit voltage estimation unit 101, an SOCV estimation unit 102 (voltage charge rate estimation unit), a reference SOCI estimation unit 103, SOCI error estimation unit 104, SOCI estimation unit 105 (current charge rate estimation unit), SOCI storage unit 106, evaluation value calculation unit 107, evaluation value storage unit 108, convergence determination unit 109, candidate update unit 110, full charge capacity estimation unit 111.

The open-circuit voltage estimation unit 101 stores the parameters of the equivalent elements of the equivalent circuit model of the secondary battery for each temperature and SOC of the secondary battery, and the equivalent circuit model to which the parameters corresponding to the actually measured temperature and the SOC are applied. The open circuit voltage of the secondary battery is calculated by applying the measured current and the measured voltage. In addition, the relationship between the parameter of the equivalent element, the temperature of the secondary battery, and the SOC is measured in advance. The SOC used for estimation of the open circuit voltage may be the SOC estimated by the SOCV estimation unit 102, the SOC estimated by the SOCI estimation unit, or the SOC estimated by other methods.
The SOCV estimation unit 102 refers to a table indicating the relationship between the open-circuit voltage and temperature of the secondary battery and the SOC, and uses the open-circuit voltage estimated by the open-circuit voltage estimation unit 101 to determine the SOC of the secondary battery (hereinafter referred to as the SOCV estimation unit 102). The estimated SOC is called SOCV) every predetermined time. Note that the relationship between the open-circuit voltage and temperature of the secondary battery and the SOC is determined in advance.

The reference SOCI estimation unit 103 uses the SOC of the previous secondary battery stored in the SOCI storage unit 106 and the measured current value of the current charged / discharged in the secondary battery, for each of the plurality of candidate full charge capacities. The SOC of the secondary battery (hereinafter referred to as the reference SOCI) when it is assumed that there is no error in the measured current is calculated every predetermined time. Here, the candidate full charge capacity is a candidate for the full charge capacity of the secondary battery at the present time.
The SOCI error estimation unit 104 estimates an error that can be included in the reference SOCI estimated by the reference SOCI estimation unit 103 based on an error included in the measured current. The error included in the measured current is determined in advance based on the measurement accuracy described in the catalog of the current sensor that measures the current of the secondary battery, or the actual value of the measurement accuracy of the current sensor measured in an experiment or the like. Set as.
Based on the SOCV estimated by the SOCV estimation unit 102, the reference SOCI estimated by the reference SOCI estimation unit 103, and the error estimated by the SOCI error estimation unit 104, the SOCI estimation unit 105 determines the SOC (hereinafter referred to as SOC) of the secondary battery. The SOC estimated by the SOCI estimation unit 105 is referred to as SOCI).
The SOCI storage unit 106 stores the SOCI last estimated by the SOCI estimation unit 105.

The evaluation value calculation unit 107 integrates the square of the difference between the SOCV estimated by the SOCV estimation unit 102 and the SOCI for each candidate full charge capacity estimated by the SOCI estimation unit 105 to evaluate the full charge capacity. Calculate the value. That is, the evaluation value is equal to the sum of squares of the difference between SOCV and SOCI for each evaluation time.
The evaluation value storage unit 108 stores the evaluation value calculated by the evaluation value calculation unit 107 for each candidate full charge capacity. The evaluation value storage unit 108 stores 0 as the initial value of the evaluation value.

Based on the evaluation value stored in the evaluation value storage unit 108, the convergence determination unit 109 calculates the distribution of evaluation values between candidate full charge capacities, and determines whether the distribution is less than a predetermined threshold. judge. In addition, a dispersion degree is a statistical value which shows dispersion | variation in values, such as a range, dispersion | distribution, and standard deviation. In this embodiment, the convergence determination unit 109 calculates a range of evaluation values between candidate full charge capacities, that is, a range in which the value can be allowed as an estimation error of the full charge capacity. It is determined whether it is less than the threshold value shown.
The candidate update unit 110 updates the candidate full charge capacity when the distribution degree of the sum of the evaluation values is equal to or greater than a predetermined threshold.
The full charge capacity estimation unit 111 estimates the full charge capacity of the secondary battery based on this value when the dispersion degree of the sum of the evaluation values is less than a predetermined threshold value.

Next, the operation of the full charge capacity estimation apparatus 100 according to the present embodiment will be described.
FIG. 2 is a flowchart showing the operation of the full charge capacity estimation apparatus 100 according to an embodiment of the present invention.
When the full charge capacity estimation apparatus 100 starts the process of estimating the full charge capacity of the secondary battery, the open-circuit voltage estimation unit 101 determines the secondary battery based on the measured current, measured voltage, measured temperature, and SOC of the secondary battery. An open circuit voltage is estimated (step S1). Specifically, the open-circuit voltage estimating unit 101 stores a plurality of parameters of each equivalent element in the equivalent circuit model of the secondary battery in association with the temperature and the SOC, and the measured current and the equivalent circuit model to which the parameter is applied are stored. The open circuit voltage of the secondary battery is calculated by substituting the measured voltage.

FIG. 3 is a diagram illustrating an example of an equivalent circuit model of the secondary battery.
In the present embodiment, as an equivalent circuit of a secondary battery, a parallel circuit of a resistor Ra and a capacitor Ca, a resistor Rd, and a power source connected in series as shown in FIG. 3 is used. The parameter of each equivalent element constituting the equivalent circuit changes according to the temperature change of the secondary battery. Therefore, the open-circuit voltage estimating unit 101 stores the resistance value Ra and the resistance value Rc of the equivalent circuit shown in FIG. 3 and the capacitance value of the capacitor Ca in association with the temperature and the SOC, and determines appropriate parameters. The open circuit voltage of the secondary battery can be calculated with high accuracy.

  Next, the SOCV estimation unit 102 calculates the SOCV of the secondary battery from the open-circuit voltage of the secondary battery and the actually measured temperature with reference to a table showing the relationship between the open-circuit voltage and temperature of the secondary battery and the SOC (Step S2). ). Specifically, the SOCV estimation unit 102 reads the SOCs associated with the two open-circuit voltages and the two temperatures closest to the measured voltage of the secondary battery from the table, and calculates the measured voltage of the secondary battery by interpolation calculation. The corresponding SOCV is calculated. As another method, the SOCV estimating unit 102 calculates an SOCV by reading an approximate expression indicating the relationship between the SOC, the open circuit voltage, and the temperature, and substituting the open circuit voltage and the actually measured temperature into the approximate expression. You can also.

  In parallel with the estimation of the SOCV by the SOCV estimation unit 102, the reference SOCI estimation unit 103 calculates the reference SOCI of the secondary battery for a plurality of candidate full charge capacities using the equation (1) (step S3).

However, SOC ₀ is the SOCI previously estimated by the SOCI estimation unit 105 and is the SOCI stored by the SOCI storage unit 106. At the time of the first execution, the SOCI storage unit 106 stores the SOC of the secondary battery measured in advance before starting the operation of the secondary battery. I _c (n) is the current value of the measured current measured at the current time (time n). T _s is the SOC calculation cycle by the full charge capacity estimation apparatus 100. Q is a candidate full charge capacity.

  The initial value of the candidate full charge capacity is preferably set in a range centered on the current full charge capacity of the secondary battery. For example, the full charge capacity of a secondary battery without deterioration is 50 ampere hours, the minimum value of the full charge capacity of the secondary battery is 40 ampere hours, the maximum value is 60 ampere hours, etc. It is preferable to set the center. In this embodiment, since the full charge capacity is estimated by the golden section search, the candidate full charge capacity uses the two golden section points in the operable range of the secondary battery and the four points of the maximum value and the minimum value. It is preferable. The golden division point is a point at which the ratio of the difference between the maximum value of the range and the point and the difference between the point and the minimum value becomes the golden ratio (1: (1 + √5) / 2).

Next, the SOCI error estimator 104 can be included in the reference SOCI estimated by the reference SOCI estimator 103 according to equation (2) based on the error that can occur during current measurement and the error that can be assumed for the battery capacity. The maximum value ΔS _errMAX (n) and the minimum value ΔS _errMIN (n) of the error are calculated for each candidate full charge capacity (step S4).

However, ΔI _c indicates the maximum value of an error that can occur in the measured current value when measuring the current. As described above, ΔI _c is a value set in advance based on the measurement accuracy described in the current sensor catalog or the measurement accuracy measured in experiments or the like. ΔQ represents the maximum value that can be assumed as an error in battery capacity. Note that ΔI _c and ΔQ are fixed values.

  Next, the SOCI estimation unit 105 estimates the possible range of the SOCI for each candidate full charge capacity by adding the maximum value and the minimum value of the error to the reference SOCI for each candidate full charge capacity (step S5). . Next, the SOCI estimation unit 105 determines, for each candidate full charge capacity, whether or not the SOCV estimated by the SOCV estimation unit 102 is within a range that the SOCI can take (step S6).

  When it is determined that the SOCV is within the range that the SOCI can take (step S6: YES), the SOCI estimation unit 105 estimates the SOCV as the SOCI (step S7). On the other hand, when it is determined that the SOCV does not exist within the range that can be taken by the SOCI (step S6: NO), the SOCI estimation unit 105 determines whether the SOCV is larger or smaller than the range ( Step S8).

  When the SOCI estimation unit 105 determines that the SOCV is larger than the range that the SOCI can take (step S8: YES), the SOCI estimation unit 105 estimates the maximum value of the range as the SOCI (step S9). On the other hand, when it is determined that the SOCV is a value smaller than the range that can be taken by the SOCI (step S8: NO), the SOCI estimation unit 105 estimates the minimum value of the range as the SOCI (step S10).

When the SOCI estimation unit 105 estimates the SOCI in step S7, S9, or S10, the SOCI estimation unit 105 records the SOCI in the SOCI storage unit 106 (step S11). Next, the evaluation value calculation unit 107 uses a value obtained by squaring a value obtained by multiplying the difference between the SOCV estimated by the SOCV estimation unit 102 and the SOCI estimated by the SOCI estimation unit 105 by the time T _s as a difference evaluation value. It calculates for every full charge capacity (step S12). That is, the difference evaluation value indicates the magnitude of the deviation that occurs between the SOCI and the SOCV during the time T _s . Then, the evaluation value calculation unit 107 calculates an evaluation value for each candidate full charge capacity by adding the difference evaluation value to the evaluation value stored in association with the candidate full charge capacity by the evaluation value storage unit 108 (step S13). Next, the evaluation value calculation unit 107 overwrites and records the evaluation value in the evaluation value storage unit 108 for each candidate full charge capacity (step S14).

Next, the convergence determination unit 109 determines whether or not the evaluation value calculation time by the evaluation value calculation unit 107 has reached a predetermined time (step S15). In the present embodiment, estimation of the full charge capacity using the sum of squares of the residuals of the estimated SOCV and SOCI during time N × T _s.

Convergence determination unit 109, the calculation time of the evaluation value by the evaluation value calculation section 107, when determining that less than N × T _s (step S15: NO), the process returns to step S1, calculation of the evaluation value at the next time I do.

On the other hand, when the convergence determination unit 109 determines that the calculation time of the evaluation value by the evaluation value calculation unit 107 has reached N × T _s (step S15: YES), the convergence determination unit 109 determines for each candidate full charge capacity. The difference between the largest and smallest evaluation values, that is, the evaluation value range is calculated (step S16).

Next, the convergence determination unit 109 determines whether or not the calculated difference value is less than a predetermined threshold (step S17). When the convergence determination unit 109 determines that the calculated difference value is equal to or greater than the predetermined threshold (step S17: NO), the accuracy of estimation of the full charge capacity is low, and therefore the candidate update unit 110 includes the reference SOCI estimation unit. The candidate full charge capacity used by 103 is updated (step S18). Specifically, the candidate full charge capacity with the maximum sum of evaluation values is excluded from the candidate full charge capacity. Then, the range from the minimum value to the maximum value of the remaining three candidate full charge capacities is set as a range that can be taken by the full charge capacity of the secondary battery, and the maximum value and the minimum value of the range, and the two golden division points, New candidate full charge capacity.
Then, the convergence determination unit 109 resets the evaluation value stored in the evaluation value storage unit 108 to 0 (step S19), returns to step S1, and continues calculating the evaluation value again.

  On the other hand, when the convergence determination unit 109 determines that the calculated difference value is less than the predetermined threshold (step S17: NO), the required charge accuracy can be ensured. The candidate full charge capacity with the minimum is estimated as the full charge capacity (step S20).

  Thus, according to the present embodiment, the full charge capacity estimation device 100 calculates the full charge capacity of the secondary battery based on the SOCI and the SOCV. Thereby, the full charge capacity estimation apparatus 100 can estimate the full charge capacity after the change even when the full charge capacity changes due to the deterioration of the secondary battery.

FIG. 4 is a diagram comparing the case where the SOCI is estimated using the integrated current value and the case where the SOCI is estimated according to the present embodiment.
Further, according to the present embodiment, the full charge capacity estimation device 100 uses the current value without using the current integrated value for the estimation of the SOCI, and further, an error that occurs in the SOCI using the SOCV by the processing of steps S6 to S9. Is corrected. As a result, the full charge capacity estimation device 100 can prevent errors from accumulating due to current integration in the SOCI, and can minimize errors contained in the SOCI, thereby estimating the full charge capacity more accurately. be able to. As shown in FIG. 4, in the SOCI based on the current integration, the influence of the error in the current measurement is accumulated, so that the calculated SOCI value gradually deviates from the true value, whereas in the present embodiment, Since the error is corrected each time for the SOCI value, accumulation of errors can be suppressed.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

For example, in the present embodiment, a case has been described in which the sum of squares of differences between SOCI and SOCV (total sum of evaluation values) is discretely calculated for each calculation cycle T _{s as} shown in steps S12 to S15. Not limited to. For example, when SOCI and SOCV can be continuously calculated by an analog circuit or the like, the sum of squares J (Q) of the difference between SOCI and SOCV may be calculated according to the following equation (3).

  However, SOCV (t) indicates the SOCV at time t. Also, SOCI (Q, T) indicates the SOCI at time t for the candidate full charge capacity Q.

  In addition, unlike the method shown in steps S12 to S15 and the method shown in equation (3), the sum of squares of the difference between SOCI and SOCV is not simply calculated, and the value is weighted according to the SOC level. Also good.

  In this embodiment, as a method for estimating the full charge capacity of the secondary battery, the maximum value and the minimum value of the range that the full charge capacity can take, and a method of narrowing using the two golden division points (golden division) Search) is used, but is not limited to this. For example, the value of Expression (4) may be calculated by a gradient method that is repeatedly executed until Expression (5) is satisfied.

  Note that γ is an adjustment coefficient, and ε is a threshold value indicating a convergence condition. γ and ε are set in advance, respectively.

  Further, if the full charge capacity estimation apparatus 100 has sufficient computing capability, the evaluation value of the evaluation value is calculated without setting five or more candidate full charge capacities and repeatedly reducing the range that the full charge capacity can take. The candidate full charge capacity that minimizes the sum may be estimated as the full charge capacity.

  In the present embodiment, the range is used as the evaluation value dispersion degree, and the convergence determination unit 109 satisfies the candidate full charge capacity that minimizes the evaluation value when the evaluation value range becomes less than a predetermined threshold. Although the case of estimating the charging capacity has been described, the present invention is not limited to this. For example, when the interval between evaluation values is used as the distribution of evaluation values, the convergence determination unit 109 satisfies the candidate full charge capacity that minimizes the evaluation value when the interval between the evaluation values is less than a predetermined threshold. The charge capacity may be estimated. In addition, dispersion and standard deviation may be used as the distribution of evaluation values.

  Moreover, although this embodiment demonstrated the case where SOCI was estimated using an electric current value, it is not restricted to this, You may estimate SOCI using an electric current integrated value.

Moreover, although this embodiment demonstrated the case where the parameter of the equivalent element of the equivalent circuit of the secondary battery used for estimation of an open circuit voltage was determined based on temperature, it is not restricted to this. For example, the open circuit voltage estimation unit 101 may calculate the parameter of the equivalent element based on the full charge capacity (the degree of battery deterioration) estimated by the full charge capacity estimation apparatus 100.
Further, in this embodiment, the equivalent circuit of the secondary battery used for estimation of the open-circuit voltage is shown in FIG. 3, but is not limited to this, and other equivalent circuits such as a resistor having only R _d are used. May be used.

  In addition, although this embodiment demonstrated operation | movement about the single unit of the full charge capacity estimation apparatus 100, it is not restricted to this. For example, the SOC is calculated more accurately by mounting the full charge capacity estimation apparatus 100 in the SOC estimation apparatus and calculating the SOC of the secondary battery using the full charge capacity calculated by the full charge capacity estimation apparatus 100. Is possible. Further, by notifying the full charge capacity calculated by the full charge capacity estimation apparatus 100 to the host system of the secondary battery, the battery capacity deterioration state, maintenance time, cell replacement time, etc. can be presented to the user.

  The full charge capacity estimation device 100 has a computer system inside. The operation of each processing unit described above is stored in a computer-readable recording medium in the form of a program, and the above processing is performed by the computer reading and executing this program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  DESCRIPTION OF SYMBOLS 100 ... Full-charge capacity estimation apparatus 101 ... Open-circuit voltage estimation part 102 ... SOCV estimation part 103 ... Reference | standard SOCI estimation part 104 ... SOCI error estimation part 105 ... SOCI estimation part 106 ... SOCI memory | storage part 107 ... Evaluation value calculation part 108 ... Evaluation value Storage unit 109 ... convergence determination unit 110 ... candidate update unit 111 ... full charge capacity estimation unit

In the present invention, the voltage charging rate estimation unit and the current charging rate estimation unit calculate charging rates at a plurality of times, and the full charge capacity estimation unit includes the voltage charging rate estimation unit at the plurality of times. The full charge capacity of the secondary battery is estimated by comparing the difference between the charge rate calculated by the above and the charge rate calculated by the current charge rate estimation unit .

In the present invention, the full charge capacity estimation unit may calculate a sum of squares of differences between the charge rate calculated by the voltage charge rate estimation unit and the charge rate calculated by the current charge rate estimation unit at the plurality of times. It is estimated that the full charge capacity used for estimating the minimum charge rate is the full charge capacity of the secondary battery.

Claims (9)

Based on the current value measured from the current charged and discharged to the secondary battery and a plurality of candidate full charge capacities that are candidates for the full charge capacity of the secondary battery, the full charge capacity of the secondary battery is respectively A current charge rate estimation unit for estimating the charge rate of the secondary battery when the value is
A voltage charge rate estimator for estimating a charge rate based on an open voltage of the secondary battery;
Among the charging rates estimated by the current charging rate estimation unit, the candidate full charging capacity used for estimation of the smallest difference from the charging rate estimated by the voltage charging rate estimation unit is the full charging capacity of the secondary battery. A full charge capacity estimation device comprising: a full charge capacity estimation unit that estimates that The current charging rate estimation unit estimates a possible range of the charging rate of the secondary battery based on an error that may occur during current measurement, and sets a value within the range as the charging rate of the secondary battery. The full charge capacity estimation apparatus according to claim 1. The current charging rate estimation unit compares the estimated range of the charging rate of the secondary battery with the charging rate estimated by the voltage charging rate estimation unit, and the charging rate estimated by the voltage charging rate estimation unit is When the value is within the range, the charging rate estimated by the voltage charging rate estimation unit is the charging rate of the secondary battery, and the charging rate estimated by the voltage charging rate estimation unit is less than the minimum value of the range. If the charging rate estimated by the voltage charging rate estimation unit is larger than the maximum value of the range, the maximum value is set as the charging rate of the secondary battery. The full charge capacity estimation apparatus according to claim 2, wherein: The voltage charging rate estimation unit and the current charging rate estimation unit calculate charging rates at a plurality of times,
4. The full charge capacity estimation unit estimates the full charge capacity of the secondary battery by comparing the difference in charge rate at the plurality of times. 5. The full charge capacity estimation device according to the item. The full charge capacity estimation unit estimates that the full charge capacity used for estimating the charge rate at which the sum of squares of the charge rate differences at the plurality of times is the minimum is the full charge capacity of the secondary battery. The full charge capacity estimation apparatus according to claim 4. The current charging rate estimation unit uses, as the candidate full charge capacity, a maximum value and a minimum value of a range that can be taken as a full charge capacity of the secondary battery, and a plurality of values within the range. The full charge capacity estimation apparatus according to any one of claims 1 to 5.   The current charging rate estimation unit is configured to estimate a range having the largest difference from the charging rate estimated by the voltage charging rate estimation unit among the charging rates previously estimated as a possible range of the full charge capacity of the secondary battery. The full charge capacity estimation apparatus according to claim 6, wherein a range from a maximum value to a minimum value of the candidate full charge capacity excluding the used candidate full charge capacity is used. A method for estimating the full charge capacity of a secondary battery,
The current charge rate estimation unit is configured to determine the secondary battery based on a current value measured from a current charged / discharged to the secondary battery and a plurality of candidate full charge capacities that are candidates for the full charge capacity of the secondary battery. Estimate the charging rate of the secondary battery when the full charge capacity of the battery is each value,
The voltage charge rate estimation unit estimates a charge rate based on an open voltage of the secondary battery,
The full charge capacity estimation unit is the candidate full charge capacity used for estimation of the smallest difference between the charge rate estimated by the voltage charge rate estimation unit and the charge rate estimated by the current charge rate estimation unit, A method for estimating a full charge capacity, characterized by estimating a full charge capacity of a secondary battery. Computer
Based on the current value measured from the current charged and discharged to the secondary battery and a plurality of candidate full charge capacities that are candidates for the full charge capacity of the secondary battery, the full charge capacity of the secondary battery is respectively A current charge rate estimation unit for estimating the charge rate of the secondary battery when the value is
A voltage charge rate estimator for estimating a charge rate based on an open voltage of the secondary battery;
Among the charging rates estimated by the current charging rate estimation unit, the candidate full charging capacity used for estimation of the smallest difference from the charging rate estimated by the voltage charging rate estimation unit is the full charging capacity of the secondary battery. A program for functioning as a full-charge capacity estimation unit that estimates that

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