WO2017002953A1

WO2017002953A1 - Data extracting device, data extracting method, and data extracting program

Info

Publication number: WO2017002953A1
Application number: PCT/JP2016/069575
Authority: WO
Inventors: 直人長岡; 長光　左千男
Original assignee: 学校法人同志社
Priority date: 2015-07-02
Filing date: 2016-07-01
Publication date: 2017-01-05

Abstract

This data extracting device 1 is provided with a storage unit 2, and an extracting unit 3 which extracts transient response data relating to a secondary battery from electric current measurement data stored in the storage unit 2. The data extracting device 1 is characterized in that the extracting unit 3 executes: a first process of specifying a first sector in which an amount of change in an electric current value is at least equal to a first threshold; a second process of specifying a preceding sector in which the amount of change relative to the electric current value at the start point of the first sector is at most equal to a second threshold; a third process of specifying a subsequent sector in which the amount of change relative to the electric current value at the end point of the first sector is at most equal to a third threshold; and a fourth process of extracting, as transient response data, electric current value data from the start point of the preceding sector to the end point of the subsequent sector.

Description

Data extraction apparatus, data extraction method, and data extraction program

The present invention relates to a data extraction apparatus, a data extraction method, and a data extraction program for extracting data suitable for diagnosis of battery deterioration of a secondary battery from measurement data of a secondary battery having transient response characteristics.

Since secondary batteries, particularly lithium ion secondary batteries, may malfunction due to battery deterioration, it is necessary to diagnose battery deterioration. As a method for diagnosing battery deterioration, a battery deterioration diagnosing method using a dedicated device based on an alternating current method has been conventionally known. However, in this battery deterioration diagnosis method, the dedicated device is expensive, and it is necessary to remove the lithium ion secondary battery from the device to be used and connect it to the dedicated device, so that the lithium ion secondary battery used for industrial devices It is not useful as a battery deterioration diagnosis method.

As another method for diagnosing battery deterioration, a battery deterioration diagnosis method is known in which internal impedance is derived from a voltage / current waveform during operation of a lithium ion secondary battery, and battery deterioration is diagnosed based on the internal impedance ( For example, refer nonpatent literature 1). However, this battery deterioration diagnosis method has a large dependency on the charging rate (SOC) and has a problem in accuracy and the like, and has not been put into practical use.

Therefore, the present inventor has developed a battery deterioration diagnosis method that is relatively inexpensive and practical, focusing on the transient response characteristics of lithium ion secondary batteries (see, for example, Japanese Patent Application No. 2015-33944). In order to diagnose the battery deterioration of the lithium ion secondary battery using this battery deterioration diagnosis method, the lithium ion secondary battery is obtained from measurement data obtained by continuously measuring the current value and voltage value of the operating lithium ion secondary battery. It is necessary to extract data at the time of transient response of the secondary battery.

The present invention has been made in view of the above circumstances, and the problem is that data at the time of transient response suitable for diagnosis of secondary battery deterioration from measurement data of a secondary battery having transient response characteristics. Is to provide a data extraction device, a data extraction method, and a data extraction program.

In order to solve the above-described problem, a data extraction device according to the present invention includes:
A storage unit for storing current measurement data obtained by measuring a current value of a secondary battery having a transient response characteristic at a predetermined sampling interval;
An extraction unit for extracting transient response data during transient response of the secondary battery from the current measurement data stored in the storage unit;
A data extraction device comprising:
The extraction unit includes:
A first process for identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second process for identifying a previous section that is continuous with a start point of the first section and that has a change amount with respect to a current value of the start point that is less than or equal to a second threshold that is smaller than the first threshold;
A third process for identifying a subsequent section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
And executing a fourth process of extracting current value data from the start point of the preceding section to the end point of the subsequent section as the transient response data.

In the above data extraction device,
The front section and the rear section are preferably wider than the first section.

The data extraction device
A battery deterioration diagnosis unit for diagnosing battery deterioration of the secondary battery;
The storage unit stores voltage measurement data obtained by measuring the voltage value of the secondary battery at the sampling interval,
In the fourth process, the extraction unit extracts voltage value data from the start point of the previous section to the end point of the rear section in the transient response data,
The battery deterioration diagnosis unit calculates a circuit parameter of an electrical equivalent circuit at the end of charging or discharging of the secondary battery based on the transient response data, and based on the circuit parameter, It can be configured to diagnose battery degradation.

In the above data extraction device,
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. A circuit in which a voltage source that outputs a voltage is connected in series is preferable.

The data extraction device
The extraction unit extracts a plurality of the transient response data,
The battery deterioration diagnosis unit
A selection process for selecting first transient response data and second transient response data from the plurality of transient response data;
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, A first calculation process for calculating a power integral value obtained by multiplying the addition result by the sampling interval;
Based on the first voltage value, the second voltage value, and the internal voltage that is the circuit parameter, a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value, and the second A second calculation process for calculating a difference from a voltage corresponding to the SOC of the secondary battery at the time of measuring a current value;
A diagnosis process for diagnosing battery deterioration of the secondary battery based on the deterioration index may be performed using a value obtained by dividing the power integral value by the difference as a deterioration index.

The data extraction device
An input receiving unit for receiving input from the user;
The input receiving unit may be configured to receive an input related to the first threshold, the second threshold, the third threshold, the range of the previous section, and the range of the subsequent section.

In order to solve the above-mentioned problem, another data extraction device according to the present invention provides:
A storage unit for storing current measurement data obtained by measuring a current value of a secondary battery having a transient response characteristic at a predetermined sampling interval, and voltage measurement data obtained by measuring a voltage value of the secondary battery at the sampling interval;
An extraction unit for extracting a plurality of transient response data at the time of transient response of the secondary battery from the current measurement data;
A battery deterioration diagnosis unit that diagnoses battery deterioration of the secondary battery based on first transient response data and second transient response data of the plurality of transient response data;
A data extraction device comprising:
The extraction unit includes:
A first process for identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second process for identifying a previous section that is continuous with a start point of the first section and that has a change amount with respect to a current value of the start point that is less than or equal to a second threshold that is smaller than the first threshold;
A third process for identifying a subsequent section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
Performing a fourth process of extracting current value data from the start point of the preceding section to the end point of the subsequent section as the transient response data;
The battery deterioration diagnosis unit
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, A first calculation process for calculating a power integral value obtained by multiplying the addition result by the sampling interval;
A second calculation process for calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value; ,
And performing a diagnosis process for diagnosing battery deterioration of the secondary battery based on the deterioration index, using a value obtained by dividing the power integral value by the difference as a deterioration index.

In the above data extraction device,
In the second calculation process, the battery deterioration diagnosis unit uses the first voltage value, the second voltage value, and circuit parameters of an electrical equivalent circuit at the end of charging or discharging of the secondary battery. Based on the difference,
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. A circuit in which a voltage source that outputs voltage is connected in series,
The circuit parameter is preferably the internal voltage.

In order to solve the above-described problem, still another data extraction device according to the present invention includes:
A storage unit for storing current measurement data obtained by measuring a current value of a secondary battery having a transient response characteristic at a predetermined sampling interval, and voltage measurement data obtained by measuring a voltage value of the secondary battery at the sampling interval;
An extraction unit for extracting a plurality of transient response data at the time of transient response of the secondary battery from the current measurement data;
A battery deterioration diagnosis unit for diagnosing battery deterioration of the secondary battery based only on first transient response data selected from the plurality of transient response data;
A data extraction device comprising:
The extraction unit includes:
A first process for identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second process for identifying a previous section that is continuous with a start point of the first section and that has a change amount with respect to a current value of the start point that is less than or equal to a second threshold that is smaller than the first threshold;
A third process for identifying a subsequent section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
Performing a fourth process of extracting current value data from the start point of the preceding section to the end point of the subsequent section as the transient response data;
The battery deterioration diagnosis unit
In the first transient response data, each current value from a first current value after a current value has changed by more than the first threshold to a second current value in the subsequent section of the first transient response data, and the first Each voltage value from the first voltage value at the time of measuring the current value to the second voltage value at the time of measuring the second current value is multiplied and each multiplication result is added, and the sampling interval is added to the addition result. A first calculation process for calculating a multiplied power integral value;
A second calculation process for calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value; ,
And performing a diagnosis process for diagnosing battery deterioration of the secondary battery based on the deterioration index, using a value obtained by dividing the power integral value by the difference as a deterioration index.

In order to solve the above problems, a data extraction method according to the present invention includes:
A data extraction method in which a data extraction device extracts transient response data at the time of transient response of the secondary battery from current measurement data obtained by measuring a current value of a secondary battery having transient response characteristics at a predetermined sampling interval,
A first step of identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second step of identifying a previous section that is continuous with a start point of the first section and in which a change amount with respect to a current value of the start point is equal to or less than a second threshold that is smaller than the first threshold;
A third step of identifying a rear section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
And a fourth step of extracting current value data from the start point of the previous section to the end point of the rear section as the transient response data.

In the above data extraction method,
The front section and the rear section are preferably wider than the first section.

The above data extraction method is:
In the fourth step, when voltage value data from the start point of the previous section to the end point of the rear section is included in the transient response data and extracted,
A circuit parameter of an electrical equivalent circuit at the end of charging or discharging of the secondary battery is calculated based on the transient response data, and a battery deterioration of the secondary battery is diagnosed based on the circuit parameter. Preferably, the method further includes a step.

In the above data extraction method,
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. A circuit in which a voltage source that outputs a voltage is connected in series is preferable.

In the above data extraction method,
A sixth step of diagnosing battery deterioration of the secondary battery based on first transient response data and second transient response data of the plurality of transient response data;
The sixth step includes
Selecting the first transient response data and the second transient response data from a plurality of the transient response data;
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, Calculating a power integral value obtained by multiplying the addition result by the sampling interval;
Based on the first voltage value, the second voltage value, and the internal voltage that is the circuit parameter, a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value, and the second Calculating a difference from a voltage corresponding to the SOC of the secondary battery at the time of measuring a current value;
And a step of diagnosing battery deterioration of the secondary battery based on the deterioration index using a value obtained by dividing the power integral value by the difference as a deterioration index.

In order to solve the above problems, another data extraction method according to the present invention is as follows.
An extraction step in which the data extraction device extracts a plurality of transient response data at the time of the transient response of the secondary battery from current measurement data obtained by measuring the current value of the secondary battery having a transient response characteristic at a predetermined sampling interval;
Based on the voltage measurement data obtained by measuring the voltage value of the secondary battery at the sampling interval, and the first transient response data and the second transient response data of the plurality of transient response data, the data extraction device includes the data A diagnostic step for diagnosing battery deterioration of the secondary battery;
A data extraction method including:
The extraction step includes
A first step of identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second step of identifying a previous section that is continuous with a start point of the first section and in which a change amount with respect to a current value of the start point is equal to or less than a second threshold that is smaller than the first threshold;
A third step of identifying a rear section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
A fourth step of extracting current value data from the start point of the previous section to the end point of the rear section as the transient response data,
The diagnostic step includes
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, Calculating a power integral value obtained by multiplying the addition result by the sampling interval;
Calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value;
And a step of diagnosing battery deterioration of the secondary battery based on the deterioration index using a value obtained by dividing the power integral value by the difference as a deterioration index.

The above data extraction method is:
In the diagnosis step, the difference is calculated based on the first voltage value, the second voltage value, and a circuit parameter of an electrical equivalent circuit at the end of charging or discharging of the secondary battery,
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. A circuit in which a voltage source that outputs voltage is connected in series,
The circuit parameter is preferably the internal voltage.

In order to solve the above problem, still another data extraction method according to the present invention is as follows.
An extraction step in which the data extraction device extracts a plurality of transient response data at the time of the transient response of the secondary battery from current measurement data obtained by measuring the current value of the secondary battery having a transient response characteristic at a predetermined sampling interval;
Based on only the voltage measurement data obtained by measuring the voltage value of the secondary battery at the sampling interval and the first transient response data selected from the plurality of transient response data, the data extraction device performs battery deterioration of the secondary battery. Diagnostic steps to diagnose
A data extraction method including:
The extraction step includes
A first step of identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second step of identifying a previous section that is continuous with a start point of the first section and in which a change amount with respect to a current value of the start point is equal to or less than a second threshold that is smaller than the first threshold;
A third step of identifying a rear section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
A fourth step of extracting current value data from the start point of the previous section to the end point of the rear section as the transient response data,
The diagnostic step includes
In the first transient response data, each current value from a first current value after a current value has changed by more than the first threshold to a second current value in the subsequent section of the first transient response data, and the first Each voltage value from the first voltage value at the time of measuring the current value to the second voltage value at the time of measuring the second current value is multiplied and each multiplication result is added, and the sampling interval is added to the addition result. Calculating a power integral value multiplied by;
Calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value;
And a step of diagnosing battery deterioration of the secondary battery based on the deterioration index using a value obtained by dividing the power integral value by the difference as a deterioration index.

In order to solve the above problems, a data extraction program according to the present invention is a program for causing a computer to execute any one of the above data extraction methods.

ADVANTAGE OF THE INVENTION According to this invention, the data extraction apparatus which can extract the data at the time of the transient response suitable for the diagnosis of the battery deterioration of a secondary battery from the measurement data of the secondary battery which has a transient response characteristic, a data extraction method, and data An extraction program can be provided.

(A) is the electrical equivalent circuit schematic of the lithium ion secondary battery which does not consider the transient response characteristic. (B) is an electrical equivalent circuit diagram of a lithium ion secondary battery in consideration of transient response characteristics and internal voltage V ₀ (SOC). (A) is an electrically equivalent circuit diagram of a lithium ion secondary battery in consideration of voltage deviation △ V ₀ of the internal voltage V _0. (B) is an electrical equivalent circuit diagram of a lithium ion secondary battery in which the voltage deviation ΔV ₀ is shown by a one-stage RC parallel circuit. FIG. 3 is an electrical equivalent circuit diagram of a lithium ion secondary battery at the end of charging or at the end of discharging. FIG. 6 is a current / voltage waveform diagram when a lithium ion secondary battery is charged with a pulse current. It is a block diagram of the data extraction device concerning one embodiment of the present invention. It is a figure for demonstrating the transient response data of this invention. (A) is current measurement data of the lithium ion secondary battery mounted on the electric motorcycle. (B) is voltage measurement data measured simultaneously with the current measurement data of (A). It is the transient response data extracted from the current measurement data and voltage measurement data of FIG. It is a block diagram of the data extraction apparatus which concerns on other embodiment of this invention. It is a figure which shows the current measurement data containing 1st transient response data and 2nd transient response data, and voltage measurement data. FIG. 7 is a diagram for comparing and explaining diagnosis of battery deterioration according to the present invention, in which (A) is a diagram in which a degradation index ΔQ / ΔV is an average value in the entire SOC region, and (B) is a degradation index. It is the figure which made (DELTA) Q / (DELTA) V the average value in SOC less than 40%. It is an electrical equivalent circuit diagram of the lithium ion secondary battery at the time of a transient response where the current is not zero. It is a figure for demonstrating the voltage change of the lithium ion secondary battery at the time of the transient response where an electric current is not zero.

Hereinafter, embodiments of a data extraction device, a data extraction method, and a data extraction program according to the present invention will be described with reference to the accompanying drawings. In the following, a lithium ion secondary battery will be described as an example of a secondary battery having transient response characteristics.

(First embodiment)
The data extraction apparatus according to the present embodiment not only extracts data at the time of transient response suitable for diagnosis of battery deterioration, but also diagnoses battery deterioration of the lithium ion secondary battery based on the extracted data at the time of transient response. . Therefore, first, an electrical equivalent circuit of a lithium ion secondary battery necessary for diagnosis of battery deterioration will be described.

[Electrical equivalent circuit]
1 to 3 show an electrical equivalent circuit (hereinafter referred to as an equivalent circuit) of a lithium ion secondary battery. The equivalent circuit shown in FIG. 1A is the simplest circuit in which an internal resistance R _B0 of a lithium ion secondary battery and a voltage source E ₀ that outputs the internal voltage V ₀ of the lithium ion secondary battery are connected in series. . In FIG. 1 (A), V _Z represents a voltage drop due to the internal impedance of the lithium ion secondary battery (internal resistance R _B0), V _B denotes the terminal voltage of the lithium ion secondary battery, I _B is the lithium ion secondary Indicates the current of the secondary battery. However, the current I _B is a positive charging direction.

In the equivalent circuit shown in FIG. 1A, the internal voltage V ₀ depends on the SOC (charge rate) of the lithium ion secondary battery. Further, for example, when charging by a pulse current is started, the terminal voltage V _B rises steeply and then gradually rises with time. On the other hand, when charging by the pulse current is finished, the terminal voltage V _B drops sharply and then time Gradually descends over time. That is, the terminal voltage V _B after the pulse current is cut off attenuates according to the transient response characteristics of the lithium ion secondary battery. Therefore, as an equivalent circuit of the lithium ion secondary battery, as shown in FIG. 1B, an internal resistance R _B0 , a two-stage RC parallel circuit, and an SOC-dependent internal voltage V ₀ (SOC) Can be used as a circuit (model A) in which a voltage source E ₀ (SOC) that outputs is connected in series. The reason why the two-stage RC parallel circuit is used in this equivalent circuit (model A) is that two slopes are observed in the waveform of the terminal voltage V _B that gradually decreases after the current interruption. This equivalent circuit (model A) is useful for a lithium ion secondary battery in which the characteristic of the internal voltage V ₀ is well known as a function of the SOC, but the SOC characteristic of the internal voltage V ₀ , that is, the internal voltage It cannot be applied to a lithium ion secondary battery in which V ₀ (SOC) is not known.

By the way, the terminal voltage V _B (0) before the start of charging corresponds to the internal voltage V ₀ (0) in the SOC before the start of charging. Further, the difference between the terminal voltage V _B (t) after the end of charging and the terminal voltage V _B (0) (= V ₀ (0)) before the start of charging is the voltage drop V _Z due to internal impedance and the internal voltage due to charging. This corresponds to the sum of the voltage deviation of V ₀ (voltage increase) ΔV ₀ . Therefore, as an equivalent circuit of the lithium ion secondary battery, as shown in FIG. 2A, a voltage source Δ that outputs an internal resistance R _B0 , a two-stage RC parallel circuit, and a voltage deviation ΔV _0. A circuit in which E ₀ and a voltage source E ₀ (0) that outputs the internal voltage V ₀ (0) are connected in series can be used. The equivalent circuit, if it is possible to know the voltage deviation △ V _0, SOC characteristic of the internal voltage V _0, that is also applicable to a lithium ion secondary battery that is not known internal voltage V _{0 (SOC)} it can. In FIG. 2 (B), a voltage source △ _{E 0} for outputting a voltage difference △ _{V 0} in the circuit shown in FIG. 2 (A), was replaced by the RC parallel circuit of one stage including the resistor _{R B3} and the capacitor _{C B3} equivalent A circuit (model B) is shown.

As described above, the terminal voltage V _B after interruption of current (after completion of charging) attenuates according to the transient response characteristics of the lithium ion secondary battery. Voltage change in this case is independent of the SOC, determined only by the voltage drop V _Z due to the internal impedance. From this, as shown in FIG. 3, as an equivalent circuit at the time of current interruption (at the end of charging) of the lithium ion secondary battery, an internal resistance R _B0 , a two-stage RC parallel circuit, and an internal voltage V ₀ (constant) circuit and a voltage source E ₀ for outputting a voltage) connected in series (model C) can be used.

Here, the internal voltage V ₀ (SOC) in the equivalent circuit (model A) shown in FIG. 1B is a function of the SOC, whereas the internal voltage V ₀ in the equivalent circuit (model C) is a constant. (Can be considered a constant). This is because within the time range in which the equivalent circuit (model C) is applied, the SOC does not change because it is within the time range in which no current flows. Therefore, in the equivalent circuit (Model C), the SOC can be estimated from the internal voltage _{V 0.} That is, in the equivalent circuit (Model C), SOC if internal voltage V ₀ is larger is large, SOC is also small if the internal voltage V ₀ is small. Therefore, if there is data (for example, a profile or a table) indicating the relationship between the internal voltage V ₀ and the SOC in the equivalent circuit (model C), the SOC can be estimated based on the data.

In the equivalent circuit (model C), the RC parallel circuit may be one stage in order to simplify the calculation of circuit parameters. For example, in the equivalent circuit shown in FIG. 3 (model C), when a two-stage RC parallel circuit is a one-stage RC parallel circuit including a resistor R _B1 and a capacitor C _B1 , The terminal voltage V _B , that is, the terminal voltage V _B at the time of transient response of the lithium ion secondary battery is given by the following equation (1).

In the case of FIG. 4 below, the terminal voltage V _B at the transient response of the lithium ion secondary battery after current interruption (after completion of charging) is given by the following equation (2).

FIG. 4 shows current / voltage waveforms when a lithium ion secondary battery is charged with a pulse current. As shown in the figure, the internal voltage V ₀ rises during charging and becomes constant after the end of charging. For this reason, in the data extraction device, the data extraction method, and the data extraction program according to the present embodiment, after the end of charging, the SOC does not change and it is not necessary to consider the fluctuation of the internal voltage V ₀ (voltage deviation ΔV ₀ ) ( or the terminal voltage V _B of the discharge after the end) is used for the diagnosis of battery deterioration. In other words, in the data extraction device, the data extraction method, and the data extraction program according to the present embodiment, the battery deterioration of the lithium ion secondary battery is performed using the equivalent circuit (model C) at the end of charging (or at the end of discharging). Diagnose.

[Data extraction device]
FIG. 5 shows a data extraction apparatus 1 according to this embodiment. The data extraction device 1 includes a storage unit 2, an extraction unit 3, a battery deterioration diagnosis unit 4, and an input reception unit 5. The memory | storage part 2, the extraction part 3, and the battery deterioration diagnostic part 4 can be comprised with a microcomputer, for example, and the input reception part 5 can be comprised with a keyboard and a display, for example.

The storage unit 2 stores measurement data obtained by continuously measuring the current value, voltage value, and ambient temperature of the operating lithium ion secondary battery at a predetermined sampling interval. Among the measurement data, the data related to the current value is called current measurement data, the data related to the voltage value is called voltage measurement data, and the data related to the ambient temperature is called temperature measurement data.

The storage unit 2 preferably stores data (for example, a profile or a table) indicating the relationship between the internal voltage V ₀ and the SOC in the equivalent circuit (model C). As described above, the equivalent circuit (model C) is an equivalent circuit at the end of charging or discharging at which the characteristic of the internal voltage V ₀ of the lithium ion secondary battery does not depend on the SOC. The internal resistance R _{B0 of the} secondary battery, the one-stage or two-stage RC parallel circuit, and the voltage source E ₀ that outputs the internal voltage V ₀ of the lithium ion secondary battery at the end of charging or discharging are connected in series. Circuit.

The extraction unit 3 extracts the transient response data during the transient response of the lithium ion secondary battery from the measurement data stored in the storage unit 2. FIG. 6 shows transient response data of the lithium ion secondary battery that has been discharged at time t1. In FIG. 6, the voltage value data and the ambient temperature data are omitted.

In order to extract the transient response data as shown in FIG.
(1) In the current measurement data, a first process for identifying a first section in which the amount of change in the current value is equal to or greater than the first threshold value X1,
(2) a second process that identifies a previous section that is continuous with the start point of the first section and in which the amount of change with respect to the current value at the start point is less than or equal to the second threshold value X2, which is smaller than the first threshold value X1;
(3) a third process for identifying a subsequent section that is continuous with the end point of the first section and whose amount of change with respect to the current value at the end point is equal to or less than a third threshold value X3 that is smaller than the first threshold value X1;
(4) a fourth process of extracting current value data from the start point of the previous section to the end point of the subsequent section, and voltage value data and ambient temperature data of the section corresponding to the current value data as transient response data;
Execute. In the present embodiment, the amount of change in the current value is expressed as an absolute value.

The battery deterioration diagnosis unit 4 calculates circuit parameters of the equivalent circuit (model C) based on the transient response data, and diagnoses battery deterioration of the lithium ion secondary battery based on the calculated circuit parameters. For example, the internal resistance _{R B0,} resistors _{R B1} and 1-step and RC parallel circuit comprising a capacitor _{C B1,} constant equivalent circuit of the voltage source _{E 0} for outputting the internal voltage _{V 0} in series connection (Model C) In this case, the internal resistance R _B0 and the resistance R _B1 of the RC parallel circuit increase as the battery deteriorates. However, since the internal resistance R _B0 is greatly affected by the contact resistance, the resistance R _B1 of the RC parallel circuit causes the battery deterioration. It is preferable to diagnose.

When diagnosing battery deterioration using the resistance R _B1 of the RC parallel circuit, the battery deterioration diagnosis unit 4 calculates circuit parameters of the equivalent circuit (model C) based on the transient response data extracted in the fourth process. Next, the battery deterioration diagnosis unit 4 estimates the SOC from the internal voltage V ₀ of the circuit parameter based on the data indicating the relationship between the internal voltage V ₀ and the SOC in the equivalent circuit (model C) stored in the storage unit 2. To do. The battery deterioration diagnosis unit 4 diagnoses the battery deterioration of the lithium ion secondary battery based on the resistance R _B1 of the circuit parameter with respect to the SOC. For example, when the resistance R _B1 is increasing even though the SOC is the same, the battery deterioration diagnosis unit 4 diagnoses that the lithium ion secondary battery is deteriorated. Since the value of the resistance R _B1 is affected by the ambient temperature, it is preferable that the battery deterioration diagnosis unit 4 statistically organizes and compares the value of the resistance R _B1 for each ambient temperature based on the temperature measurement data. .

The input receiving unit 5 receives input from the user regarding the first threshold value X1, the second threshold value X2, the third threshold value X3, the range of the previous section and the range of the subsequent section before the extraction unit 3 executes the first process. Accept. When the input reception unit 5 receives an input from the user, the extraction unit 3 executes the first process to the fourth process according to the input from the user, and the battery deterioration diagnosis unit 4 diagnoses the battery deterioration as described above. In addition, it is preferable to limit a user's input so that a front area and a rear area may become a range wider than a 1st area.

[Data extraction method]
Next, a data extraction method according to this embodiment will be described. In the data extraction method according to the present embodiment, the data extraction device 1 extracts transient response data from measurement data obtained by measuring the current value, voltage value, and ambient temperature of a lithium ion secondary battery at a predetermined sampling interval. .

Specifically, the data extraction method according to this embodiment is:
(1) In the current measurement data, a first step for identifying a first section in which the amount of change in the current value is equal to or greater than the first threshold value X1;
(2) a second step of specifying a previous section that is continuous with the start point of the first section and in which a change amount with respect to the current value of the start point is equal to or less than a second threshold value X2 that is smaller than the first threshold value X1;
(3) a third step of specifying a rear section that is continuous with the end point of the first section and in which the amount of change with respect to the current value of the end point is equal to or less than a third threshold value X3 that is smaller than the first threshold value X1;
(4) a fourth step of extracting current value data from the start point of the previous section to the end point of the subsequent section, and voltage value data and ambient temperature data of the section corresponding to the current value data as transient response data;
(5) calculating a circuit parameter of an equivalent circuit (model C) of the lithium ion secondary battery based on the transient response data, and diagnosing the battery deterioration of the lithium ion secondary battery based on the circuit parameter;
including.

As an example of measurement data, FIG. 7A shows current measurement data for several years of a lithium ion secondary battery mounted on an electric motorcycle, and FIG. 7B corresponds to the current measurement data ( Voltage measurement data (measured simultaneously with the current measurement data) is shown. The sampling interval of current measurement data and voltage measurement data is 0.5 seconds. In addition, the electric motorcycle used in this experiment has no regenerative function, and the lithium ion secondary battery mounted on the electric motorcycle is discharged while the electric motorcycle is running, but charging and discharging are performed when the electric motorcycle is stopped. Absent. Hereinafter, a data extraction method in which the data extraction apparatus 1 extracts transient response data (see FIG. 8) at the end of discharge from the measurement data shown in FIGS. 7A and 7B will be described.

Before the extraction unit 3 and the battery deterioration diagnosis unit 4 of the data extraction device 1 execute the data extraction method, the input reception unit 5 of the data extraction device 1 performs the first threshold value X1, the second threshold value X2, the third threshold value X3, It is assumed that an input from the user is received regarding the range of the previous section and the range of the subsequent section. Here, the first threshold value X1 is set to 12 [A], the second threshold value X2 is set to 8 [A], the third threshold value X3 is set to 2 [A], the range of the previous section (number of data) and the range of the subsequent section ( The number of data is 4 for all. Further, it is assumed that the range (number of data) of the first section is set to 2.

In the first step, the extraction unit 3 is based on the n (n is an integer of 1 or more) current value data and the (n + 1) th current value data included in the current measurement data in FIG. Then, the change amount of the current value is calculated, and the first section (the number of data = 2) in which the change amount of the current value is equal to or larger than the first threshold value X1 (= 12 [A]) is specified. As shown in FIG. 8, the current value at 150.0 seconds is −13.04 [A], and the current value at 150.5 seconds is −0.42 [A]. The amount of change in value is 12.62 [A], which is equal to or greater than the first threshold value X1 (= 12 [A]). Therefore, the extraction unit 3 identifies the section from 150.0 seconds to 150.5 seconds as the first section.

In the second step, the extraction unit 3 is continuous with the current value data at 150.0 seconds, which is the start point of the first section, and changes with respect to the current value at the start point of the first section (current value at 150.0 seconds). The previous section (the number of data = 4) in which the amount is equal to or less than the second threshold value X2 (= 8 [A]) is specified. As shown in FIG. 8, current value data at 150.0 seconds and four current value data continuous, that is, current value data at 148.0 seconds, 148.5 seconds, 149.0 seconds, and 149.5 seconds. In both cases, the amount of change with respect to the current value at 150.0 seconds is equal to or less than the second threshold value X2 (= 8 [A]). Therefore, the extraction unit 3 identifies the section from 148.0 seconds to 149.5 seconds as the previous section.

In the third step, the extraction unit 3 continues to the current value data at 150.5 seconds, which is the end point of the first section, and changes with respect to the current value at the end point of the first section (current value at 150.5 seconds). A rear section (the number of data = 4) in which the amount is equal to or less than the third threshold value X3 (= 2 [A]) is specified. As shown in FIG. 8, the current value data at 150.5 seconds and four current value data continuous, that is, current value data at 151.0 seconds, 151.5 seconds, 152.0 seconds, and 152.5 seconds. In both cases, the amount of change with respect to the current value at 150.5 seconds is equal to or less than the third threshold value X3 (= 2 [A]). Therefore, the extraction unit 3 specifies a section from 151.0 seconds to 152.5 seconds as a subsequent section.

In the fourth step, the extraction unit 3 obtains the current value data from the start point of 148.0 seconds that is the start point of the previous section to the end point of 152.5 seconds that is the end point of the subsequent section, the voltage value data and the ambient temperature data of the same section. Extracted as transient response data. That is, transient response data is extracted only when all of the previous section, the first section, and the subsequent section are specified by the extraction unit 3.

In the fifth step, the battery deterioration diagnosis unit 4 calculates the circuit parameters of the equivalent circuit (model C) based on the transient response data extracted by the extraction unit 3, and the lithium ion secondary based on the calculated circuit parameters. Diagnose battery deterioration. For example, the internal resistance _{R B0,} resistors _{R B1} and 1-step and RC parallel circuit comprising a capacitor _{C B1,} constant equivalent circuit of the voltage source _{E 0} for outputting the internal voltage _{V 0} in series connection (Model C) In this case, the battery deterioration diagnosis unit 4 calculates the internal resistance R _B0 , the resistance R _B1 , the capacitor C _B1, and the internal voltage V ₀ based on the transient response data. Next, the battery deterioration diagnosis unit 4 estimates the SOC from the internal voltage V ₀ based on data indicating the relationship between the internal voltage V ₀ and the SOC in the equivalent circuit (model C) stored in the storage unit 2. The battery deterioration diagnosis unit 4 diagnoses the battery deterioration of the lithium ion secondary battery based on the resistance R _B1 to the SOC.

[Data extraction program]
Next, the data extraction program according to this embodiment will be described. The data extraction program according to the present embodiment is for causing a computer to execute the above-described data extraction method.

A data extraction program according to the present embodiment is provided to a computer via a storage medium or a network, and the computer reads out and executes the data extraction program according to the present embodiment, so that the computer has at least a part of data. It functions as the extraction device 1 and can execute the data extraction method described above.

After all, according to the data extraction device 1, the data extraction method, and the data extraction program according to the present embodiment, it is suitable for diagnosis of battery deterioration of the lithium ion secondary battery from the measurement data of the lithium ion secondary battery having transient response characteristics. Transient response data can be extracted automatically. Furthermore, according to the data extraction device 1, the data extraction method, and the data extraction program according to the present embodiment, the circuit parameters of the equivalent circuit (model C) of the lithium ion secondary battery are calculated based on the extracted transient response data. Thus, the battery deterioration of the lithium ion secondary battery can be diagnosed.

(Second Embodiment)
Next, a data extraction apparatus, a data extraction method, and a data extraction program according to the second embodiment will be described.

[Data extraction device]
FIG. 9 shows a data extraction apparatus 1 ′ according to this embodiment. The data extraction apparatus 1 ′ according to this embodiment includes a storage unit 2, an extraction unit 3, a battery deterioration diagnosis unit 4 ′, and an input reception unit 5. In addition, since the component which attached | subjected the code | symbol same as FIG. 5 is the same as that of what was demonstrated in 1st Embodiment, description is abbreviate | omitted here.

The battery deterioration diagnosis unit 4 ′ includes two transient response data (first transient response data and first transient response data) from a plurality of transient response data extracted by the extraction unit 3 executing the first to fourth processes on the current measurement data. 2nd transient response data) is selected. The user can arbitrarily set how to select the first transient response data and the second transient response data in the input reception unit 5. For example, as shown in FIG. 10, two adjacent transient response data may be the first transient response data and the second transient response data, or the first extracted transient response data is the first transient response data, and X The transient response data extracted in the order (X ≧ 3) may be used as the second transient response data.

The battery deterioration diagnosis unit 4 ′
(1) As described above, a selection process for selecting first transient response data and second transient response data from a plurality of transient response data;
(2) The second current value A2 after the current value has changed more than the first threshold value X1 in the second transient response data from the first current value A1 after the current value has changed more than the first threshold value X1 in the first transient response data. Current values (A1,..., A2) and voltage values from the first voltage value V1 when measuring the first current value A1 to the second voltage value V2 when measuring the second current value A2. (V1,..., V2) are multiplied and each multiplication result is added, and the addition result is multiplied by a sampling interval ΔT. Power integral value ΔQ (= (V1 × A1 +... + V2 × A2) ) × ΔT), a first calculation process;
(3) The difference between the voltage VE1 corresponding to the SOC of the lithium ion secondary battery at the time of measuring the first current value A1 and the voltage VE2 corresponding to the SOC of the lithium ion secondary battery at the time of measuring the second current value A2. A second calculation process for calculating V (>0);
(4) A diagnostic process for diagnosing battery deterioration of the lithium ion secondary battery based on the degradation index ΔQ / ΔV, with a value obtained by dividing the power integral value ΔQ by the difference ΔV as a degradation index ΔQ / ΔV; ,
Execute.

In the first calculation process, the battery deterioration diagnosis unit 4 ′ acquires each current value from the first current value A1 to the second current value A2 based on the current measurement data stored in the storage unit 2, and the storage unit 2 Each voltage value from the first voltage value V1 to the second voltage value V2 is acquired based on the voltage measurement data stored in the. In addition, the battery deterioration diagnosis unit 4 ′ determines the SOC of the lithium ion secondary battery based on the first voltage value V1, the second voltage value V2, and the electrical equivalent circuit (model C) in the second calculation process. Corresponding voltages VE1 and VE2 are calculated, and a difference ΔV is calculated.

Specifically, the first voltage value V1 and the second voltage value V2, the equation (2) it is equal to the terminal voltage V _B, from the first voltage value V1 and the equation (2), the first voltage value The internal voltage V ₀ (V1) at the time of measuring V1 can be calculated, and the internal voltage V ₀ (V2) at the time of measuring the second voltage value V2 is calculated from the second voltage value V2 and the above equation (2). can do. Here, the voltage VE corresponding to the SOC of the lithium ion secondary battery is a voltage that is a constant that does not depend on the SOC or a linear function when the current is constant, and that can estimate the SOC from the voltage. In the case of an electrical equivalent circuit (model C), the internal voltage V ₀ is a voltage VE corresponding to the SOC of the lithium ion secondary battery. Thus, battery deterioration diagnosis unit 4 'includes an internal voltage _V 0 (V1) corresponding to SOC (V1), from the internal voltage _V 0 corresponding to SOC (V2) (V2), the difference △ _{V (=} V 0 ( V2) −V ₀ (V1) or = V ₀ (V1) −V ₀ (V2)), that is, the difference ΔV (= VE2−VE1 or = VE1−VE2) can be calculated.

The battery deterioration diagnosis unit 4 ′ diagnoses the battery deterioration of the lithium ion secondary battery based on the deterioration index ΔQ / ΔV for the SOC in the diagnosis process. For example, when the absolute value of the deterioration index ΔQ / ΔV is decreasing despite the SOC being the same, the battery deterioration diagnosis unit 4 ′ diagnoses that the lithium ion secondary battery has deteriorated.

The battery deterioration diagnosis unit 4 ′ determines whether ΔV is an appropriate value in the second calculation process when calculating ΔQ / ΔV in the diagnosis process. May be skipped. For example, when ΔV is a potential difference of 0 to less than 10% in SOC, the diagnosis process (calculation of ΔQ / ΔV) may not be performed. When the diagnosis process is skipped in this way, the battery deterioration diagnosis unit 4 ′ performs the selection process again and again sets two transient response data (first transient response data) so that at least one transient response data is different from the previous one. And the second transient response data) can be selected.

[Data extraction method]
Next, a data extraction method according to this embodiment will be described. The data extraction method according to the present embodiment includes an extraction step and a diagnosis step.

The extraction step is a step in which the data extraction device 1 ′ according to the second embodiment extracts a plurality of transient response data from the current measurement data, and is mostly common to the first embodiment. That is, the extraction step is:
(1) In the current measurement data, a first step for identifying a first section in which the amount of change in the current value is equal to or greater than the first threshold value X1;
(2) a second step of specifying a previous section that is continuous with the start point of the first section and in which a change amount with respect to the current value of the start point is equal to or less than a second threshold value X2 that is smaller than the first threshold value X1;
(3) a third step of specifying a rear section that is continuous with the end point of the first section and in which the amount of change with respect to the current value of the end point is equal to or less than a third threshold value X3 that is smaller than the first threshold value X1;
(4) a fourth step of extracting current value data from the start point of the previous section to the end point of the subsequent section as transient response data;
including.

In the diagnosis step, the data extraction device 1 ′ according to the second embodiment selects two transient response data (first transient response data and second transient response data) from the plurality of transient response data extracted in the extraction step, This is a step of diagnosing battery deterioration of the lithium ion secondary battery based on the first transient response data and the second transient response data.

Specifically, the diagnostic step is:
(1) selecting first transient response data and second transient response data from a plurality of transient response data (for example, see FIG. 10);
(2) The second current value A2 after the current value has changed more than the first threshold value X1 in the second transient response data from the first current value A1 after the current value has changed more than the first threshold value X1 in the first transient response data. Current values (A1,..., A2) and voltage values from the first voltage value V1 when measuring the first current value A1 to the second voltage value V2 when measuring the second current value A2. (V1,..., V2) are multiplied and each multiplication result is added, and the addition result is multiplied by a sampling interval ΔT. Power integral value ΔQ (= (V1 × A1 +... + V2 × A2) ) × ΔT),
(3) The difference between the voltage VE1 corresponding to the SOC of the lithium ion secondary battery at the time of measuring the first current value A1 and the voltage VE2 corresponding to the SOC of the lithium ion secondary battery at the time of measuring the second current value A2. Calculating V (>0);
(4) A value obtained by dividing the power integral value ΔQ by the difference ΔV is set as a deterioration index ΔQ / ΔV, and the battery deterioration of the lithium ion secondary battery is diagnosed based on the deterioration index ΔQ / ΔV;
including. Since each step is the same as the selection process, the first calculation process, the second calculation process, and the diagnosis process of the battery deterioration diagnosis unit 4 ′, description thereof is omitted.

[Data extraction program]
Next, the data extraction program according to this embodiment will be described. The data extraction program according to the present embodiment is for causing a computer to execute the data extraction method according to the second embodiment. In other words, the computer functions as the data extraction device 1 ′ according to the second embodiment.

After all, according to the data extraction apparatus 1 ′, the data extraction method, and the data extraction program according to the present embodiment, it is suitable for diagnosis of battery deterioration of the lithium ion secondary battery from the measurement data of the lithium ion secondary battery having transient response characteristics. The transient response data can be extracted automatically. Furthermore, according to the data extraction device 1 ′, the data extraction method, and the data extraction program according to the present embodiment, the degradation index Δ is based on the extracted two transient response data (first transient response data and second transient response data). By calculating Q / ΔV, battery deterioration of the lithium ion secondary battery can be diagnosed using the deterioration index ΔQ / ΔV.

By the way, for battery deterioration of a lithium ion secondary battery, the internal resistance increases even if the battery capacity decreases (deteriorates) even if the internal resistance does not change or the battery capacity does not change. (Deterioration) or internal resistance and battery capacity may be deteriorated. FIG. 11 shows the battery capacity [kWh] (solid line in FIG. 11), resistance R _B1 [Ω] (black circle in FIG. 11), deterioration index ΔQ / ΔV [kWh] with respect to the number of charge / discharge cycles. / V] (black square in FIG. 11). In FIG. 11, the alternate long and short dash line indicates an approximate curve of the resistance R _B1 , and the broken line indicates an approximate curve of the deterioration index ΔQ / ΔV. In addition, the scale of the vertical axis is adjusted for comparison.

11A and 11B, the battery capacity of the lithium ion secondary battery is measured by fully discharging the lithium ion secondary battery and then fully discharging it. The resistance R _B1 is measured by the data extraction device 1 according to the first embodiment. The degradation index ΔQ / ΔV is measured by the data extraction apparatus 1 ′ according to the second embodiment, but the degradation index ΔQ / ΔV in (A) is the entire SOC range of the lithium ion secondary battery. The deterioration index ΔQ / ΔV of (B) is the deterioration index ΔQ / Δ when the SOC of the lithium ion secondary battery is less than 40%. Average value of V.

As shown in FIGS. 11A and 11B, the resistance R _B1 increases as the number of charge / discharge cycles increases. On the other hand, the deterioration index ΔQ / ΔV and the battery capacity of the lithium ion secondary battery decrease with the same tendency as the number of charge / discharge cycles increases. In particular, in FIG. 11A, it can be seen that the deterioration index ΔQ / ΔV can express the change in the original battery capacity of the lithium ion secondary battery fairly accurately. Also, in FIG. 11B, although instability (increase in estimated variation) is observed for the degradation index ΔQ / ΔV, a decreasing trend with an increase in the number of charge / discharge cycles is observed. From the above, it is possible to diagnose the deterioration of the battery capacity of the lithium ion secondary battery by measuring the deterioration index ΔQ / ΔV. More specifically, the measurement area is a low SOC area (here, less than 40% SOC). Even in the case of (region), it can be seen that battery capacity deterioration can be diagnosed, and when the measurement area is the entire SOC area, battery capacity deterioration can be diagnosed more accurately. That is, according to the first embodiment, deterioration of the internal resistance of the lithium ion secondary battery can be diagnosed, and according to the second embodiment, deterioration of the battery capacity of the lithium ion secondary battery can be diagnosed.

Therefore, by combining the first embodiment and the second embodiment, specifically, the function of the battery deterioration diagnosis unit 4 ′ is added to the battery deterioration diagnosis unit 4 of the first embodiment, or the second By adding the function of the battery deterioration diagnosis unit 4 to the battery deterioration diagnosis unit 4 ′ of the embodiment, the battery deterioration of the lithium ion secondary battery is (1) when only the internal resistance is deteriorated, and (2) It can be broadly divided into a case where only the battery capacity is deteriorated and a case (3) where both the internal resistance and the battery capacity are deteriorated.

For example, lithium ion secondary batteries for automobiles cannot be used for automobiles if their internal resistance has deteriorated, but if the battery capacity has not deteriorated (including cases where the deterioration is relatively small), It can be reused as a lithium ion secondary battery. By using the first embodiment and the second embodiment in combination, a reusable lithium ion secondary battery can be selected.

The embodiments of the data extraction apparatus, the data extraction method, and the data extraction program according to the present invention have been described above, but the present invention is not limited to the above embodiments.

(Modification regarding the first embodiment)
For example, in the data extraction device 1 according to the first embodiment, the storage unit 2 and the extraction unit 3, the battery deterioration diagnosis unit 4, and the input reception unit 5 can be separate devices. In this case, only the storage unit 2 and the extraction unit 3 are the data extraction device according to the present invention. Furthermore, in this case, the first to fourth steps except for the fifth step are included in the data extraction method according to the present invention, and the data extraction program causes the computer to execute the data extraction method that does not include the fifth step. Program.

When the range (number of data) of the first section is set to 3 or more, the amount of change in the current value in the first process and the first step is the current value data at the start point of the first section and the end point of the first section. Calculation can be performed based on the current value data. For example, when the range (number of data) of the first section is 3, the extraction unit 3 determines the current value based on the nth current value data and the (n + 2) th current value data included in the current measurement data. Can be calculated. Note that the range of the previous section and the range of the rear section are preferably set so as to be wider (the number of data is larger) than the range of the first section.

In the first embodiment, the electric motorcycle having no regenerative function is taken as an example. Of course, the present invention can also be applied to a hybrid car having a regenerative function. In this case, not only the current change from the discharge to the current interruption in the first section but also the change from the charge to the current interruption may be detected.

Furthermore, if the amount of current change in the previous section and the subsequent section is within the respective threshold values, the present invention can be applied with a slight correction even if the current change in the first section is somewhat overshooted or undershooted. For example, even if the current changes from discharging to charging (through current interruption), if the current change thereafter (in the subsequent section) is small, the voltage during charging increases monotonously (conversely, changing from charging to discharging) In this case, it is predicted that the voltage decreases monotonously), and if the amount is corrected, the voltage change at the time of current interruption can be estimated. That is, these are estimation methods corresponding to model A and model B.

(Modification regarding the second embodiment)
For the calculation of the resistance R _B1 in the battery deterioration diagnosis of the first embodiment, it is effective to use a means (data extraction method or data extraction apparatus) based on a data extraction program using the model C, but the battery of the second embodiment The calculation of the deterioration index ΔQ / ΔV in the deterioration diagnosis uses the power integrated value between any two points without depending on the data extraction program (data extraction method or data extraction apparatus) using the model C. Is also possible. However, in order not to depend on a data extraction program using the model C, it is necessary to apply other methods such as the model A and the model B that can execute the estimation of the resistance R _{B1 and} the estimation of the SOC. Note that model A and model B do not assume after current interruption as in model C, and therefore target an arbitrary waveform of current during transient response, where the current is not zero.

When the current waveform during a transient response where the current is not zero is targeted, the degradation index ΔQ / ΔV is calculated using the circuit parameters of the equivalent circuit (model C ′) during the transient response as described below. Thus, the deterioration of the battery capacity of the lithium ion secondary battery can be diagnosed in substantially the same manner as in the second embodiment.

FIG. 12 shows an equivalent circuit (model C ′) at the time of transient response. The equivalent circuit, the equivalent circuit (Model C) shown in FIG. 3, with the addition of a voltage source △ E ₀ for outputting a voltage difference △ V ₀ of the internal voltage V _0. Although the voltage difference △ V ₀ is also present in the equivalent circuit shown in FIG. 2 (A), the voltage difference △ V ₀ shown in FIG. 2 (A) that is an arbitrary function, voltage deviation in the model C '△ V ₀ is a linear function. From this equivalent circuit (model C ′), the terminal voltage V _B at the transient response of the lithium ion secondary battery is given by the following equation (3).

In the equation (3), ΔV ₀ is a term that expresses a change in the internal voltage V ₀ due to charging or discharging of the lithium ion secondary battery as described above, and changes monotonically with time when the current is constant. It is a linear function. ΔV ₀ monotonously decreases in the case of discharging and monotonously increases in the case of charging.

Further, as shown in FIGS. 13A to 13C, during the transient response where the current is not zero (model C ′), the voltage change I (see FIG. 13A) causes the transient response where the current becomes zero. when the voltage change (model C) II (see FIG. 13 (B)), plus the voltage variation III represented by the voltage difference △ _{V 0} of the internal voltage _{V 0} (or minus the voltage change III (See FIG. 13C), it can be seen that the terminal voltage V _B of the lithium ion secondary battery at the time of transient response where the current is not zero is given by the above equation (3).

Therefore, when the circuit parameters of the equivalent circuit (model C ′) are used, the battery deterioration diagnosis unit 4 ′
(1) In the selection process, the first transient response data and the second transient response data at the time of the transient response in which the current is not zero are selected from the plurality of transient response data extracted by the extraction unit 3,
(2) In the first calculation process, each current value (A1,..., A2) from the first current value A1 in the first transient response data to the second current value A2 in the second transient response data; Each multiplication is performed by multiplying each voltage value (V1,..., V2) from the first voltage value V1 when measuring the first current value A1 to the second voltage value V2 when measuring the second current value A2. The result is added, and the power integration value ΔQ (= (V1 × A1 +... + V2 × A2) × ΔT) obtained by multiplying the addition result by the sampling interval ΔT is calculated.
(3) In the second calculation process, the voltage VE1 corresponding to the SOC of the lithium ion secondary battery at the time of measuring the first current value A1 (= the internal voltage V ₀ (V1) of the equation (3) + voltage deviation ΔV ₀ (V1)) and the voltage VE2 corresponding to the SOC of the lithium ion secondary battery at the time of measuring the second current value A2 (= the internal voltage V ₀ (V2) + voltage deviation ΔV ₀ (V2) in equation (3)) ΔV (> 0) is calculated from
(4) In the diagnosis process, a value obtained by dividing the power integral value ΔQ by the difference ΔV is set as a deterioration index ΔQ / ΔV, and the battery deterioration of the lithium ion secondary battery is diagnosed based on the deterioration index ΔQ / ΔV. To do.

Furthermore, in the second embodiment, a combination is possible in which the power integration value ΔQ between the two points of the time point obtained by the model C and the time point estimated by the other models A and B is calculated. It is. For example, each current from the first current value A1 included in the first transient response data to the third current value A3 included in the third transient response data extracted by another method (method using model A or model B). The value (A1,..., A3) is multiplied by the respective voltage values (V1,..., V3) from the first voltage value V1 to the third voltage value V3 when measuring the third current value A3. In addition, the multiplication results may be added, and the power integration value ΔQ (= (V1 × A1 +... + V3 × A3) × ΔT) obtained by multiplying the addition result by the sampling interval ΔT may be calculated.

In the second embodiment, the battery deterioration of the lithium ion secondary battery is determined by using the deterioration index ΔQ / ΔV calculated from the two transient response data (first transient response data and second transient response data). Although the diagnosis is made, the battery deterioration of the lithium ion secondary battery may be diagnosed using the deterioration index ΔQ / ΔV calculated from only one transient response data.

For example, when only the first transient response data is used, the battery deterioration diagnosis unit 4 ′
(1) selection processing for selecting first transient response data from a plurality of transient response data;
(2) the current value from the first current value A1 after the current value in the first transient response data changes first threshold X1 or until the current value A _X of the first in the interval after the transient response data (A1, ..., and _{a X),} each voltage value from the first voltage value V1 at the time of measurement of the first current value A1 to a voltage value _{V X} during measurement of the current value _{a X} (V1, ..., _{V X} ) And adding each multiplication result and multiplying the addition result by a sampling interval ΔT to obtain a power integral value ΔQ (= (V1 × A1 +... + V _X × A _X ) × ΔT). A first calculation process to calculate;
(3) the difference between the voltages VE _X corresponding to the SOC of the lithium ion secondary battery at the time of measurement of the voltage VE1 and current values A _X corresponding to the SOC of the lithium ion secondary battery at the time of measurement of the first current value A1 △ A second calculation process for calculating V (>0);
(4) A diagnostic process for diagnosing battery deterioration of the lithium ion secondary battery based on the degradation index ΔQ / ΔV, with a value obtained by dividing the power integral value ΔQ by the difference ΔV as a degradation index ΔQ / ΔV; ,
Execute.

The method of this modification (a method of calculating the degradation index ΔQ / ΔV from only one transient response data) and the method of the second embodiment (the degradation index ΔQ / ΔV is calculated from two transient response data) It is preferable to use a different method based on the following points.
(1) The method of the second embodiment is effective when the frequency of current change (transient response) is high and the frequency of appearance of extracted transient response data is high.
(2) In the method of this modification, the frequency of current change (transient response) is low and the frequency of appearance of the extracted transient response data is low, but the current value after the current change (after transient response) is constant. Is effective when the battery continues (when the discharged state or the charged state continues).

In addition, it is preferable that the range of the first transient response data in this modification is wider than the range of the first transient response data in the second embodiment.

(Other variations)
In each of the above embodiments, a lithium ion secondary battery has been described as an example of a secondary battery. However, the data extraction device and the data extraction method according to the present invention can be used as long as the secondary battery has transient response characteristics. It can be applied to other than ion secondary batteries.

Further, the present invention can be applied to a storage battery in a solar power generation system for supplying electric power to a house, for example, besides transportation means such as a car and a motorcycle. This is because even in this type of system, the charging / discharging current may be interrupted or changed to a state close thereto due to a sudden change in the weather. However, since changes are generally gentle compared to cars and motorcycles, some optimization is required, such as increasing the sampling interval accordingly (for example, 2 seconds or more).

DESCRIPTION OF SYMBOLS 1, 1 'Data extraction device 2 Memory | storage part 3 Extraction part 4, 4' Battery deterioration diagnostic part 5 Input reception part

Claims

A storage unit for storing current measurement data obtained by measuring a current value of a secondary battery having a transient response characteristic at a predetermined sampling interval;
An extraction unit for extracting transient response data during transient response of the secondary battery from the current measurement data stored in the storage unit;
A data extraction device comprising:
The extraction unit includes:
A first process for identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second process for identifying a previous section that is continuous with a start point of the first section and that has a change amount with respect to a current value of the start point that is less than or equal to a second threshold that is smaller than the first threshold;
A third process for identifying a subsequent section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
And a fourth process of extracting current value data from the start point of the preceding section to the end point of the subsequent section as the transient response data.
The data extraction apparatus according to claim 1, wherein the front section and the rear section are wider than the first section.
A battery deterioration diagnosis unit for diagnosing battery deterioration of the secondary battery;
The storage unit stores voltage measurement data obtained by measuring the voltage value of the secondary battery at the sampling interval,
In the fourth process, the extraction unit extracts voltage value data from the start point of the previous section to the end point of the rear section in the transient response data,
The battery deterioration diagnosis unit calculates a circuit parameter of an electrical equivalent circuit at the end of charging or discharging of the secondary battery based on the transient response data, and based on the circuit parameter, The data extraction apparatus according to claim 1, wherein battery deterioration is diagnosed.
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. 4. The data extraction device according to claim 3, wherein the data extraction device is a circuit in which a voltage source that outputs a voltage is connected in series.
The extraction unit extracts a plurality of the transient response data,
The battery deterioration diagnosis unit
A selection process for selecting first transient response data and second transient response data from the plurality of transient response data;
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, A first calculation process for calculating a power integral value obtained by multiplying the addition result by the sampling interval;
Based on the first voltage value, the second voltage value, and the internal voltage that is the circuit parameter, a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value, and the second A second calculation process for calculating a difference from a voltage corresponding to the SOC of the secondary battery at the time of measuring a current value;
5. The diagnosis processing for diagnosing battery deterioration of the secondary battery based on the deterioration index is performed using a value obtained by dividing the power integral value by the difference as a deterioration index. Data extraction device.
An input receiving unit for receiving input from the user;
2. The data extraction device according to claim 1, wherein the input receiving unit receives an input related to the first threshold, the second threshold, the third threshold, the range of the previous section, and the range of the rear section. .
A storage unit for storing current measurement data obtained by measuring a current value of a secondary battery having a transient response characteristic at a predetermined sampling interval, and voltage measurement data obtained by measuring a voltage value of the secondary battery at the sampling interval;
An extraction unit for extracting a plurality of transient response data at the time of transient response of the secondary battery from the current measurement data;
A battery deterioration diagnosis unit that diagnoses battery deterioration of the secondary battery based on first transient response data and second transient response data of the plurality of transient response data;
A data extraction device comprising:
The extraction unit includes:
A first process for identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second process for identifying a previous section that is continuous with a start point of the first section and that has a change amount with respect to a current value of the start point that is less than or equal to a second threshold that is smaller than the first threshold;
A third process for identifying a subsequent section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
Performing a fourth process of extracting current value data from the start point of the preceding section to the end point of the subsequent section as the transient response data;
The battery deterioration diagnosis unit
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, A first calculation process for calculating a power integral value obtained by multiplying the addition result by the sampling interval;
A second calculation process for calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value; ,
A data extraction apparatus that performs a diagnosis process for diagnosing battery deterioration of the secondary battery based on the deterioration index, using a value obtained by dividing the power integral value by the difference as a deterioration index.
In the second calculation process, the battery deterioration diagnosis unit uses the first voltage value, the second voltage value, and circuit parameters of an electrical equivalent circuit at the end of charging or discharging of the secondary battery. Based on the difference,
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. A circuit in which a voltage source that outputs voltage is connected in series,
The data extraction apparatus according to claim 7, wherein the circuit parameter is the internal voltage.
A storage unit for storing current measurement data obtained by measuring a current value of a secondary battery having a transient response characteristic at a predetermined sampling interval, and voltage measurement data obtained by measuring a voltage value of the secondary battery at the sampling interval;
An extraction unit for extracting a plurality of transient response data at the time of transient response of the secondary battery from the current measurement data;
A battery deterioration diagnosis unit for diagnosing battery deterioration of the secondary battery based only on first transient response data selected from the plurality of transient response data;
A data extraction device comprising:
The extraction unit includes:
A first process for identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second process for identifying a previous section that is continuous with a start point of the first section and that has a change amount with respect to a current value of the start point that is less than or equal to a second threshold that is smaller than the first threshold;
A third process for identifying a subsequent section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
Performing a fourth process of extracting current value data from the start point of the preceding section to the end point of the subsequent section as the transient response data;
The battery deterioration diagnosis unit
In the first transient response data, each current value from a first current value after a current value has changed by more than the first threshold to a second current value in the subsequent section of the first transient response data, and the first Each voltage value from the first voltage value at the time of measuring the current value to the second voltage value at the time of measuring the second current value is multiplied and each multiplication result is added, and the sampling interval is added to the addition result. A first calculation process for calculating a multiplied power integral value;
A second calculation process for calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value; ,
A data extraction apparatus that performs a diagnosis process for diagnosing battery deterioration of the secondary battery based on the deterioration index, using a value obtained by dividing the power integral value by the difference as a deterioration index.
A data extraction method in which a data extraction device extracts transient response data at the time of transient response of the secondary battery from current measurement data obtained by measuring a current value of a secondary battery having transient response characteristics at a predetermined sampling interval,
A first step of identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second step of identifying a previous section that is continuous with a start point of the first section and in which a change amount with respect to a current value of the start point is equal to or less than a second threshold that is smaller than the first threshold;
A third step of identifying a rear section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
And a fourth step of extracting current value data from the start point of the preceding section to the end point of the subsequent section as the transient response data.
The data extraction method according to claim 10, wherein the front section and the rear section are wider than the first section.
In the fourth step, voltage value data from the start point of the previous section to the end point of the rear section is included in the transient response data and extracted.
A circuit parameter of an electrical equivalent circuit at the end of charging or discharging of the secondary battery is calculated based on the transient response data, and a battery deterioration of the secondary battery is diagnosed based on the circuit parameter. The data extraction method according to claim 10, further comprising a step.
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. 13. The data extraction method according to claim 12, wherein the data extraction method is a circuit in which a voltage source that outputs a voltage is connected in series.
A sixth step of diagnosing battery deterioration of the secondary battery based on first transient response data and second transient response data of the plurality of transient response data;
The sixth step includes
Selecting the first transient response data and the second transient response data from a plurality of the transient response data;
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, Calculating a power integral value obtained by multiplying the addition result by the sampling interval;
Based on the first voltage value, the second voltage value, and the internal voltage that is the circuit parameter, a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value, and the second Calculating a difference from a voltage corresponding to the SOC of the secondary battery at the time of measuring a current value;
The data extraction method according to claim 13, further comprising: diagnosing battery deterioration of the secondary battery based on the deterioration index using a value obtained by dividing the power integral value by the difference as a deterioration index. Method.
An extraction step in which the data extraction device extracts a plurality of transient response data at the time of the transient response of the secondary battery from current measurement data obtained by measuring the current value of the secondary battery having a transient response characteristic at a predetermined sampling interval;
Based on the voltage measurement data obtained by measuring the voltage value of the secondary battery at the sampling interval, and the first transient response data and the second transient response data of the plurality of transient response data, the data extraction device includes the data A diagnostic step for diagnosing battery deterioration of the secondary battery;
A data extraction method including:
The extraction step includes
A first step of identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second step of identifying a previous section that is continuous with a start point of the first section and in which a change amount with respect to a current value of the start point is equal to or less than a second threshold that is smaller than the first threshold;
A third step of identifying a rear section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
A fourth step of extracting current value data from the start point of the previous section to the end point of the rear section as the transient response data,
The diagnostic step includes
Each of the first transient response data from the first current value after the current value changes more than the first threshold value to the second current value after the current value changes more than the first threshold value in the second transient response data. Multiplying the current value by each voltage value from the first voltage value at the time of measuring the first current value to the second voltage value at the time of measuring the second current value, and adding each multiplication result, Calculating a power integral value obtained by multiplying the addition result by the sampling interval;
Calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value;
And a step of diagnosing battery deterioration of the secondary battery based on the deterioration index using a value obtained by dividing the power integral value by the difference as a deterioration index.
In the diagnosis step, the difference is calculated based on the first voltage value, the second voltage value, and a circuit parameter of an electrical equivalent circuit at the end of charging or discharging of the secondary battery,
The electrical equivalent circuit corresponds to a series resistance corresponding to the internal resistance of the secondary battery, a one-stage or two-stage RC parallel circuit, and an internal voltage of the secondary battery at the end of charging or discharging. A circuit in which a voltage source that outputs voltage is connected in series,
The data extraction method according to claim 15, wherein the circuit parameter is the internal voltage.
An extraction step in which the data extraction device extracts a plurality of transient response data at the time of the transient response of the secondary battery from current measurement data obtained by measuring the current value of the secondary battery having a transient response characteristic at a predetermined sampling interval;
Based on only the voltage measurement data obtained by measuring the voltage value of the secondary battery at the sampling interval and the first transient response data selected from the plurality of transient response data, the data extraction device performs battery deterioration of the secondary battery. Diagnostic steps to diagnose
A data extraction method including:
The extraction step includes
A first step of identifying a first section in which the amount of change in the current value is equal to or greater than a first threshold;
A second step of identifying a previous section that is continuous with a start point of the first section and in which a change amount with respect to a current value of the start point is equal to or less than a second threshold that is smaller than the first threshold;
A third step of identifying a rear section that is continuous with the end point of the first section and whose amount of change with respect to the current value of the end point is equal to or less than a third threshold value that is smaller than the first threshold value;
A fourth step of extracting current value data from the start point of the previous section to the end point of the rear section as the transient response data,
The diagnostic step includes
In the first transient response data, each current value from a first current value after a current value has changed by more than the first threshold to a second current value in the subsequent section of the first transient response data, and the first Each voltage value from the first voltage value at the time of measuring the current value to the second voltage value at the time of measuring the second current value is multiplied and each multiplication result is added, and the sampling interval is added to the addition result. Calculating a power integral value multiplied by;
Calculating a difference between a voltage corresponding to the SOC of the secondary battery at the time of measuring the first current value and a voltage corresponding to the SOC of the secondary battery at the time of measuring the second current value;
And a step of diagnosing battery deterioration of the secondary battery based on the deterioration index using a value obtained by dividing the power integral value by the difference as a deterioration index.
A data extraction program for causing a computer to execute the data extraction method according to any one of claims 10 to 17.