WO2022018810A1

WO2022018810A1 - Data extraction device for storage battery and data extraction method for storage battery

Info

Publication number: WO2022018810A1
Application number: PCT/JP2020/028161
Authority: WO
Inventors: 翔治吉田; 裕二西川; 涼大嶋; 優斗沖田; 直人長岡
Original assignee: 日新電機株式会社; 学校法人同志社
Priority date: 2020-07-20
Filing date: 2020-07-20
Publication date: 2022-01-27
Also published as: JPWO2022018810A1

Abstract

On the basis of the C-rate value of a storage battery 15, a data extraction unit 23 determines a stable transition in an early interval of a transient response time depending on whether, during said early interval, at least a period T₁ (first period) continuously passed in which variation was less than or equal to a threshold value α (first threshold value), determines a sudden transition in a variation interval depending on whether, during said variation interval, variation that was greater than or equal to a threshold value β (second threshold value) occurred within a period T₃ (second period), and determines a stable transition in a late interval depending on whether, during said late interval, at least a period T₅ (third period) continuously passed in which variation was less than or equal to a threshold value γ (third threshold value). If data extraction parameters including each of these determinations are satisfied, the data extraction unit 23 extracts data regarding this transient reponse time from a storage unit 22.

Description

Storage battery data extraction device and storage battery data extraction method

The present invention relates to a storage battery data extraction device and a storage battery data extraction method for performing deterioration diagnosis by transient response analysis of the storage battery.

The introduction of stationary storage battery systems that apply lithium-ion batteries is expanding for the purpose of effective use of renewable energy and power supply in the event of a disaster. Understanding the soundness and characteristics of a storage battery that deteriorates over time and charging / discharging is extremely important for operating the system, and the deterioration state of the storage battery is grasped and diagnosed.

As a deterioration diagnosis technique for a storage battery, for example, there is a technique disclosed in Patent Document 1 that uses the transient response characteristics of a storage battery in operation. The technique disclosed in Patent Document 1 is to extract current value data at the time of transient response of the storage battery and perform deterioration diagnosis of the storage battery based on the analysis of the extracted current value data at the time of transient response.

Japanese Unexamined Patent Publication No. 2017-16991

The present inventor considers that it is one of the effective means to extract more useful data such as the current value at the time of transient response from the storage battery in order to improve the accuracy of the deterioration diagnosis of the storage battery by the above method. There is. That is, the accuracy of the deterioration diagnosis of the storage battery is to properly grasp the target transient response characteristics in order to carefully select the transient response characteristics that enhance the accuracy of the deterioration diagnosis of the storage battery, and to extract more useful data such as the current value at the time of the transient response. I think it will lead to improvement.

An object of the present invention is to provide a storage battery data extraction device and a storage battery data extraction method that can improve the accuracy of storage battery deterioration diagnosis.

The storage battery data extraction device that solves the above problems has a storage unit that stores detected value data capable of diagnosing deterioration of the storage battery at predetermined sampling intervals, and a storage unit that stores the detected value data stored in the storage unit during a transient response of the storage battery. A storage battery data extraction device including a data extraction unit for extracting such data, wherein the data extraction unit is a variable section in which a C rate value or a current value or a power value suddenly changes based on a detection value of the storage battery. It is divided into at least three sections, the front section of the fluctuation section and the rear section of the fluctuation section. In the fluctuation section, the C rate value, the current value, or the power value fluctuates by the second threshold value or more within the second hour, and the sudden change transition in the fluctuation section is determined. Judgment of the stable transition of the rear section in which the fluctuation of the rate value or the current value or the power value continues for the third time or more at the third threshold value or less is performed, and when the data extraction condition based on each judgment is satisfied, the storage unit. It is configured to extract the relevant data at the time of the corresponding transient response from.

According to the above-mentioned extraction device, the data extraction unit is based on the C rate value, the current value, or the power value of the storage battery, and in the previous section before the sudden change, the fluctuation of the first threshold value or less is continued for the first hour or more. The stable transition is judged, and in the fluctuation section, the sudden change transition of the fluctuation section due to the fluctuation of the second threshold or more within the second hour is judged, and in the latter section, the fluctuation of the fluctuation of the third threshold or less continues for the third hour or more. Judge the stable transition of the rear section. Then, when the data extraction conditions based on each determination are satisfied, the data extraction unit extracts the data related to the corresponding transient response from the storage unit. That is, when the desired transient response characteristics satisfying the conditions are shown in each of the front section, the fluctuation section, and the rear section at the time of the transient response, the corresponding data is extracted from the storage unit. In addition, when it comes to data extraction related to transient response, it is easy to pay attention to the sudden change transition of the fluctuation section. Since it is included, it is possible to extract data showing more desirable transient response characteristics. Therefore, it can be fully expected that the deterioration diagnosis of the storage battery based on the data extracted in this way will be performed with higher accuracy.

In the data extraction device of the storage battery, the data extraction unit further determines whether the magnitude of the C rate value, the current value, or the power value is equal to or less than the fourth threshold value in the previous section, or further in the previous section. It is preferable that it is configured to determine whether or not the fluctuation of the voltage value based on the detected value of the storage battery is equal to or less than the fifth threshold value, or both.

According to the above aspect, the data extraction unit determines whether the magnitude of the C rate value, the current value, or the power value in the previous section is equal to or less than the fourth threshold value, or the fluctuation of the voltage value of the storage battery in the previous section is the fifth threshold value. It is determined whether it is the following, or both. That is, since the data extraction unit more preferably defines the stable transition in the previous section, it is possible to extract data showing more desirable transient response characteristics, and further improvement in the accuracy of the deterioration diagnosis of the storage battery can be expected.

In the data extraction device of the storage battery, the data extraction unit is further configured to determine whether the sudden change in the C rate value, the current value, or the power value has converged within the fourth hour in the fluctuation section. Is preferable.

According to the above aspect, the data extraction unit further determines whether the sudden change in the C rate value, the current value, or the power value in the fluctuation section has converged within the fourth hour. That is, since the data extraction unit more preferably defines the sudden change transition of the fluctuation section, it is possible to extract data showing more desirable transient response characteristics, and further improvement in the accuracy of the deterioration diagnosis of the storage battery can be expected.

In the data extraction device of the storage battery, the data extraction unit erroneously determines that the local approximate transition that may occur near the change point of the C rate value or the current value or the power value in the fluctuation section is a stable transition in the subsequent section. It is preferable that it is configured not to.

Here, since a local approximate transition may occur near the change point of the C rate value or the current value or the power value in the fluctuation section, it is easy to erroneously determine that the transition is stable in the subsequent section. Then, in this case, even if there is data showing desirable transient response characteristics, there is a possibility that data extraction will not be performed if it is erroneously determined that the transition is stable in the subsequent section. According to the above aspect, the data extraction unit exhibits desirable transient response characteristics because it does not erroneously determine the local approximate transition that may occur near the change point such as the C rate value in the fluctuation section as the stable transition in the subsequent section. It is possible to extract as much data as possible.

In the data extraction device of the storage battery, the data extraction unit further determines whether the fluctuation of the C rate value, the current value, or the power value is within the fifth hour in the previous section, and when the fluctuation exceeds the fifth hour. , It is preferable that the data stored in the storage unit is configured to delete the portion exceeding the first time.

According to the above aspect, the data extraction unit further determines whether the fluctuation of the C rate value, the current value, or the power value in the previous section is within the fifth hour. Then, when the fifth time is exceeded, the data extraction unit deletes the data stored in the storage unit that exceeds the first hour. That is, the number of data to be stored in the storage unit is suppressed, and it is possible to use an inexpensive storage device having a small storage capacity.

In the data extraction device of the storage battery, it is preferable that the data extraction unit is configured to perform each of the determinations based on the C rate value.

According to the above aspect, the data extraction unit makes each determination based on the C rate value. That is, since the C rate value is an index indicating the charge / discharge speed of the storage battery, it can be commonly used for storage batteries having various battery capacities, and it is expected that the versatility of the data extraction device will be improved.

A storage battery data extraction method that solves the above problems stores detection value data capable of diagnosing deterioration of the storage battery in a storage unit at predetermined sampling intervals, and from the detection value data stored in the storage unit during a transient response of the storage battery. It is a data extraction method of a storage battery for extracting such data, and is a fluctuation section in which a C rate value or a current value or a power value suddenly changes based on a detection value of the storage battery, a section before the fluctuation section and a section after the fluctuation section. It is divided into at least three sections, and in the previous section, the stable transition of the previous section in which the fluctuation of the C rate value or the current value or the power value continues for the first hour or more at the first threshold value or less is determined. The sudden change transition of the fluctuation section in which the C rate value or the current value or the power value fluctuates by the second threshold value or more within the second hour is determined, and in the latter section, the fluctuation of the C rate value or the current value or the power value is the third. The stable transition of the post-section that continues for the third hour or more below the threshold value is determined, and when the data extraction conditions based on the determinations are satisfied, the data related to the corresponding transient response is extracted from the storage unit.

According to the above extraction method, it is possible to extract data showing more desirable transient response characteristics as in the above extraction device, so that it can be fully expected that deterioration diagnosis of the storage battery will be performed with higher accuracy.

In the storage battery data extraction method, it is further determined in the previous section whether the magnitude of the C rate value, the current value, or the power value is equal to or less than the fourth threshold value, or in the previous section, the detection value of the storage battery is further determined. It is preferable to determine whether or not the fluctuation of the voltage value based on the fifth threshold value is equal to or less than the fifth threshold value, or both.

According to the above aspect, it is possible to extract data showing more desirable transient response characteristics as in the above extraction device, so that it can be fully expected that deterioration diagnosis of the storage battery will be performed with higher accuracy.

According to the storage battery data extraction device and the storage battery data extraction method of the present invention, it is possible to improve the accuracy of the deterioration diagnosis of the storage battery.

A block diagram of the entire system for explaining the deterioration diagnosis of the storage battery. The flow chart of the data extraction processing of the storage battery of 1st Embodiment. Explanatory drawing which concerns on the data extraction processing of the storage battery of 1st Embodiment. The flow chart which shows the example of the partial change of the data extraction process of a storage battery. Explanatory drawing which concerns on the example of partial modification of the data extraction process of a storage battery. The waveform diagram which shows the actual measurement pattern 1 of the storage battery of 1st Embodiment. The waveform diagram which shows the actual measurement pattern 2 of the storage battery of 1st Embodiment. The waveform diagram which shows the actual measurement pattern 3 of the storage battery of 1st Embodiment. The waveform diagram which shows the actual measurement pattern 4 of the storage battery of the comparative example. The waveform diagram which shows the actual measurement pattern 5 of the storage battery of the comparative example. A circuit diagram showing an equivalent circuit of a storage battery used in transient response analysis. The result figure of the transient response analysis of 1st Embodiment and a comparative example. The flow chart of the data extraction processing of the storage battery of 2nd Embodiment. Explanatory drawing which concerns on the data extraction processing of the storage battery of 2nd Embodiment. The result figure of the transient response analysis of the 1st embodiment used for the comparison of the 2nd embodiment. The result figure of the transient response analysis of 2nd Embodiment. The result figure of the transient response analysis of 2nd Embodiment. The result figure of the transient response analysis of 2nd Embodiment.

(First Embodiment)
Hereinafter, a first embodiment of a storage battery data extraction device and an extraction method thereof will be described.

As shown in FIG. 1, the photovoltaic power generation system 11 as a distributed power source using renewable energy includes a solar panel 12 and a photovoltaic power conditioner 13. The photovoltaic power generation system 11 converts the DC power generated by the solar panel 12 into commercial AC power by the power conditioner 13 for photovoltaic power generation, and converts the converted AC power into a power system via the grid interconnection facility 10. It is configured to be able to supply to. The storage battery system 14 includes a storage battery 15 made of a stationary lithium ion battery or the like and a power conditioner 16 for the storage battery, and is attached to the photovoltaic power generation system 11. The storage battery system 14 charges and discharges the storage battery 15 for output smoothing so that the rate of change of the output power of the photovoltaic power generation system 11 in which the generated power can fluctuate greatly becomes a predetermined value or less, and the power conditioner 16 for the storage battery. It suppresses output fluctuations to the power system through power conversion.

A measuring instrument 17 is installed in the storage battery system 14. The measuring instrument 17 is an ammeter 18, a voltmeter 19, a thermometer 20, and the like. The ammeter 18 detects the charge / discharge current of the storage battery 15 and outputs the detection signal to the data extraction device 21. The voltmeter 19 detects the input / output voltage of the storage battery 15 and outputs the detection signal to the data extraction device 21. The thermometer 20 detects the temperature of the storage battery 15, the ambient temperature, and the like, and outputs the detection signal to the data extraction device 21.

The data extraction device 21 includes a storage unit 22 and a data extraction unit 23. The storage unit 22 stores current value data based on the detection signal from the ammeter 18, voltage value data based on the detection signal from the voltmeter 19, and temperature data based on the detection signal from the voltmeter 20 at predetermined sampling intervals. It is possible. In the present embodiment, the data extraction unit 23 stores that the change mode of the C rate value of the storage battery 15 that can be calculated based on the current value data shows a predetermined charge / discharge characteristic (transient response characteristic) as a data extraction condition. The current value data, the voltage value data, and the temperature data are output from the unit 22 to the battery deterioration diagnosis device 24 together with the time data. The C rate value of the storage battery 15 is an index indicating the charge / discharge speed of the storage battery 15, and is a useful parameter that can be commonly used for storage batteries 15 having various battery capacities. The details of the data extraction condition (data extraction process) of the data extraction unit 23 will be described later.

The battery deterioration diagnosis device 24 performs transient response analysis using the equivalent circuit 25 of the storage battery 15 shown in FIG. 11 based on the extracted data of the storage battery 15 extracted from the data extraction unit 23. That is, the battery deterioration diagnosis device 24 compares the transient response analysis value based on the current value, voltage value, and temperature of the storage battery 15 associated with the time with the predetermined reference value for the transient response analysis stored in advance, and the storage battery. Perform 15 deterioration diagnoses.

Next, the data extraction process of the present embodiment in the data extraction unit 23 will be described with reference to FIGS. 2 and 3.

In the data extraction process of the present embodiment, the current value, the voltage value, and the temperature of the storage battery 15 are changed only when the desired change is made in any of the front section, the fluctuation section, and the rear section at the time of the transient response of the C rate value. Data extraction is performed.

In step S1 of the data extraction process, the C rate value of the storage battery 15 at the _{time t 0} set immediately after the start of the extraction process or the previous process is set as the _{reference C 0} value, and every _{time t n} of the subsequent sampling cycle is set. The difference from the C _n _{value | C 0-} C _n | is calculated. This time t ₀ is the reference time of the previous section before the transient response.

In step S2, it is determined whether or not the time at which the difference | C _{0 −} C _n | is equal to or less than the threshold value α _{continues from the time t 0} to the time T _{1 or more.} The threshold value α is, for example, 0.005 to 0.1 [C]. The time T ₁ is, for example, 10 to 5000 [s], and in the present embodiment, the time length is about 0.1 to 10 times the _{time T 4} _{when the time T 4} described later in the variable interval is used as a reference. Set. The reference time T ₄ is, for example, 1 to 500 [s]. That is, in the step S2, determines the transient response before the previous section, or remained time above T ₁ stably at a C-rate value is a threshold value α following small variations. If the difference | C _0- C _n | is equal to or less than the threshold value α _{and does not continue for the time T 1} or more (determination NO), the process proceeds to step S3, the time t _n is updated to the time t ₀ again, and the process is returned to the step S1. ..

On the other hand, if it is determined in step S2 that the difference | C ₀ −C _n _{| continues for the time T 1} or more at the threshold value α or less (determination YES), the process proceeds to step S4.

In step S4, the difference _| determines the threshold value α follows since time period _{T 2} within the time _{t 0} | C ₀ -C _n. The time T ₂ is, for example, 200 to 50,000 [s], and in the present embodiment, the time T 2 is set to a time length of about 2 to 100 times the _{time T 1.} If it is determined that the time equal to or less than the threshold α of the difference | C _{0 −} C _n | exceeds the time T ₂ _{from the time t 0} (determination NO), the process proceeds to step S5, and the storage unit 22 stores the time in association with the time. current value, remove the voltage and temperature various data time (T 2 _-T ₁₎ minute, and updates the first time in the time T ₁ minute of data left in the memory unit 22 at time t _0. That is, by suppressing the number of data to be stored in the storage unit 22, it is possible to use an inexpensive storage device having a small storage capacity.

On the other hand, if it is determined in step S4 that the time equal to or less than the threshold value α _{of the difference | C 0 −} C _n | is within the time T ₂ _{from the time t 0} (determination YES), the process proceeds to step S6. That is, in order to proceed to step S6, it is a case where the time at which the difference | C _{0 −} C _n | is equal to or less than the threshold value α _{continues from the time t 0} to the time T ₁ or more and is within the _{time T 2.}

In step S6, the difference within the time _{T 3} from the predetermined time _{t a} _| determines the threshold value β or become data exists | C 0 -C _n. The threshold value β is, for example, 0.1 to 10 [C], and is set to a value of about 5 to 1000 times the threshold value α in the present embodiment. The time T ₃ is, for example, 1 to 200 [s], and in the present embodiment, the time T ₃ is set to a time length of about 0.1 to 0.8 times the time T 4. That is, it is determined whether In step S6, C rate value is large variations over the threshold β in a short time within the time T ₃ has occurred. Time t _a is a time serving as a reference for the variation interval of the transient response. Time _{t a} from the time _{T 3} within the difference _| C 0 -C _n _| if threshold β or more data is not present (decision NO), the process proceeds to step S3, updates the time _{t n} again at time _{t 0} Then, the process returns to step S1.

On the other hand, in step S6, the time _{t a} from the time _{T 3} within the difference _| C 0 -C _n _| When it is determined that the threshold value β or more data exists (decision YES), the process proceeds to step S7.

In step S7, _{the difference | C n −} C _{n + 1} | of the two C rate values arranged in time from the time _{t b} _{where the difference | C 0 −} C _n | becomes the threshold value β or more is calculated.

In step S8, the difference _| determines the threshold value γ hereinafter become data exists within the time _{T 4} from the time _{_{t a | C n -C n +}} 1. The threshold value γ is, for example, 0.005 to 0.1 [C], and is set to the same value as the threshold value α in the present embodiment. That is, the step S8, including the sudden change in the C-rate values, determines whether stable to small variations in threshold again γ within the time T _4. Difference _| updated if the threshold value γ following data is not present within the time _{T 4} from the time _{t a} (determination NO), the process proceeds to step S3, the time _{t n} again time _{t 0} a | C _{n -C} n _{+ 1} Then, the process returns to step S1.

On the other hand, in step S8, the difference _| C _{n -C} n _{+ 1} _| of the threshold γ following data is determined to exist within the time _{T 4} from the time _{t a} (determination YES), the process proceeds to step S9.

In step S9, the C rate value at the _{time t d} when the difference | C _{n −} C _{n + 1} | is equal to or less than the threshold value γ _{is set as the reference C d} value, and the C _n value at _{each time t n} of the subsequent sampling cycle is set. Difference | C _d −C _n | is calculated. This time t _d is a reference time for the rear section after the transient response.

In step S10, it is determined whether or not the time at which the difference | C _{d −} C _n | is equal to or less than the threshold value γ _{continues from the time t d} to the time T _{5 or more.} That is, in the step S10, judges in the section after the post-transient response, whether remained time T ₅ or stably with small variations in C-rate value threshold γ below. _{The time T 5} is, for example, 10 to 5000 [s], and in the present embodiment, the time T 5 is set to a time length of about 0.1 to 10 times the _{time T 1.} When the difference | C _{d −} C _n | is equal to or less than the threshold value γ _{and does not continue for the time T 5} or more (determination NO), the process proceeds to step S11.

_{In step S11, the difference | C n −} C _{n + 1} | of the C rate value after the time when the determination NO is determined in step S10 is calculated.

In step S12, except the data it is judged NO in step S10, the time _{t a} from the time _{T 4} within the difference _| determine the threshold γ hereinafter become data exists | C _{n -C} n _{+ 1.} If there is no data equal to or less than the threshold value γ of the difference | C _{n −} C _{n + 1} | within the time T ₄ _{(determination NO), the process proceeds to step S3 above, the time t n} is updated to the time t ₀ again, and the process is performed. Return to step S1.

On the other hand, in step S12, except the data is judged NO in step S10, the time _{T 4} within the difference _| C _{n -C} n _{+ 1} _| determines that the threshold value γ following data exists (decision YES), step Proceed to S9.

Here, even if a desirable transient response occurs in the C rate value halfway, the two C rate values that are lined up in time may approximate each other _{near the change point (near time t b in FIG. 3).} , Difference | C _{n −} C _{n + 1} | can be within the threshold value γ. However, since hard time T ₅ or more continuous, after determination NO in step S10, if the through step S3, that constitute a process flow returns to step S1, losing one data extraction opportunity desirable transient response It can be. Therefore, in the present embodiment, the processing flow is configured as in steps S11 and S12, and if the determination is NO in step S10 but the determination is YES in step S12, the process is returned to step S9 and the processing is continued. We are trying to obtain as many opportunities for data extraction as possible for the desired transient response.

Then, in step S10, when it is determined that the time equal to or less than the threshold value γ _{of the difference | C d −} C _n _{| continues from the time t d} to the time T ₅ or more (determination YES), the C rate value determines the desired transient response characteristic. Assuming that it is shown, the process proceeds to step S13. In step S13, a series of current values, voltage values, and temperatures of the storage battery 15 are extracted from the storage unit 22 together with the time and output to the battery deterioration diagnosis device 24.

As a modification of the data extraction processing is started counting the time T ₄ from the time t _a immediately before the transient response of the C-rate value starts, as shown in FIGS. 4 and 5, the transient of C-rate values The time T ₄ _{may be started from the time t b} immediately after the response becomes equal to or higher than the threshold value β, and this time T ₄ may be used for the determination in step S8a shown in FIG. Although not shown, the start of counting of the time T ₄ used in step S12 shown in FIG. 2 will be changed to the time t _b. _{The time T 4} shown in FIG. 5 is set to, for example, the same time length as the _{time T 3.}

In this way, the change mode of the previous section of the C rate value is carefully selected by passing through the steps S1 and S2, and then the change mode of the variable section is carefully selected by passing through the steps S6 to S8, and further, the change mode of the variable section is carefully selected. , S10, the change mode of the rear section is carefully selected. Since the current value, voltage value, and temperature of the storage battery 15 obtained through these processes show the desirable transient response characteristics carefully selected, the accuracy of the deterioration diagnosis by the battery deterioration diagnosis device 24 is higher. It can be fully expected that it will be.

Incidentally, the change mode of the C rate value shown in FIG. 6 (pattern 1), the change mode of the C rate value shown in FIG. 7 (pattern 2), and the change mode of the C rate value shown in FIG. 8 (pattern 3) are all. It shows a desirable transient response characteristic obtained through the above processing flow of this embodiment. On the other hand, the change mode of the C rate value (pattern 4) shown in FIG. 9 is _{the mode of the comparative example in which the time T 1} deviates from the condition, and the change mode of the C rate value (pattern 5) shown in FIG. 10 is the time T _3. It is an aspect of the comparative example in which and the time T _{4 deviate from the conditions.} The transient response analysis results of each of these patterns 1 to 5 are represented as Ri values of the equivalent circuit 25 of the storage battery 15 shown in FIG. 11, and are as shown in FIG. The broken line in the figure is the true value of the Ri value.

The deterioration diagnosis of the storage battery 15 based on the extracted data of the comparative example showing the transient response characteristics of the

patterns

4 and 5 has a relatively large deviation from the true value shown by the broken line in FIG. 12, and the diagnosis accuracy is high. No. On the other hand, the deterioration diagnosis of the storage battery 15 based on the extracted data of the present embodiment showing the transient response characteristics of patterns 1 to 3 has a very small deviation from the true value shown by the broken line in FIG. 12, and is diagnosed with high accuracy. You can see that is being done. In this way, it is possible to improve the accuracy of the deterioration diagnosis of the storage battery 15 by carefully selecting the transient response characteristics as in the present embodiment, extracting only the data of the carefully selected storage battery 15, and using it for the deterioration diagnosis.

The effect of this embodiment will be explained.

(1-1) Based on the C rate value of the storage battery 15, the data extraction unit 23 depends on whether the fluctuation of the threshold value α (first threshold value) or less in the previous section before the sudden change _{continues for the time T 1} (first time) or more. Judge the stable transition of the previous section. Next, in the fluctuation section, the sudden change transition of the fluctuation section depending on whether or not the fluctuation is equal to or more than the threshold value β (second threshold value) within the _{time T 3 (second time) is determined.} Next, in the rear section, the stable transition of the rear section is determined depending on whether the fluctuation is equal to or less than the threshold value γ (third threshold) and _{continues for the time T 5 (third time) or longer.} Then, when the data extraction conditions including each determination are satisfied, the data extraction unit 23 extracts the data related to the corresponding transient response from the storage unit 22. That is, when the desired transient response characteristics satisfying the conditions are shown in each of the front section, the fluctuation section, and the rear section at the time of the transient response, the corresponding data is extracted from the storage unit 22. Although tend to focus to a sudden change transition of the variation interval becomes data extraction according to the transient response time, a predetermined time (time T ₁ and time T ₅₎ more stable transitions prior section and rear section in the study of the present inventors Is also important, and it is included in the judgment, so data showing more desirable transient response characteristics is being extracted. Therefore, it can be fully expected that the deterioration diagnosis of the storage battery 15 by the battery deterioration diagnosis device 24 based on the data extracted by the data extraction device 21 will be performed with higher accuracy.

(1-2) data extraction unit 23 further determines whether the sudden change transition of C-rate values in the variation interval has converged within the time T _{4 (4} hours). That is, since the data extraction unit 23 more preferably defines the sudden change transition of the fluctuation section, it is possible to extract data showing more desirable transient response characteristics, and further improvement in the accuracy of the deterioration diagnosis of the storage battery 15 can be expected.

(1-3) The data extraction unit 23 does not erroneously determine the local approximate transition that may occur near the change point of the C rate value ( _{near time t b in FIG. 3) in the fluctuation section as the stable transition in the subsequent section (1-3).} Since the processing of steps S11 and S12 is included), as much data as possible showing the desired transient response characteristics can be extracted.

(1-4) The data extraction unit 23 further determines whether the fluctuation of the C rate value in the previous section is _{within the time T 2} (fifth time). Exceeding the time _{T 2} (5 hours), the data extraction unit 23 deletes the time _{T 1} of the stored data in the storage unit 22 (first hour) minute exceeded (time _T 2 -T ₁ minute) do. That is, the number of data stored in the storage unit 22 can be suppressed, and an inexpensive storage device having a small storage capacity can be used.

(1-5) The data extraction unit 23 is configured to perform each determination based on the C rate value in the present embodiment. Since the C rate value is an index indicating the charge / discharge speed of the storage battery 15, it can be commonly used for storage batteries 15 having various battery capacities, and improvement in versatility of the data extraction device 21 can be expected.

(Second Embodiment)
Hereinafter, a second embodiment of the storage battery data extraction device and the extraction method thereof will be described.

The data extraction process of the data extraction unit 23 in the present embodiment is a partial modification of the data extraction process (see FIG. 2) of the first embodiment. In the following, the changes will be mainly described with reference to FIGS. 13 and 14 and the like.

In the data extraction process of the present embodiment, a new step Sa is inserted between steps S4 and S6 of the data extraction process of the first embodiment. Up to step S4, it is determined whether or not the C rate value has stably changed with a small fluctuation of _{the difference | C 0 −} C _n | of the C rate value in the previous section before the transient response, which is equal to or less than the threshold value α. .. When the C rate value is determined to be a desired stable transition, the process proceeds to step Sa.

In step Sa, C rate value of the size of the battery 15 at time _{T 1} of the front section _{| C max} | Do (the first embodiment) for determining threshold alpha ₂ below. The magnitude | C _max | of the C rate value is, for example, a peak value in this embodiment. The threshold value α ₂ is, for example, 0.005 to 0.1 [C]. Or, instead of the determination, variation V _max -V _min voltage value of the battery 15 at time T ₁ of the previous interval (a second aspect) threshold alpha _v or less of which may be to perform the determination .. In the present embodiment, the fluctuation amount V _max −V _min of the voltage value is, for example, the difference between the maximum value and the minimum value. The threshold value α _v is, for example, 0.5 to 50 [mV]. Furthermore, instead of their determination, the magnitude of the C-rate values of the battery 15 at time _{T 1} of the front section _{| C max} | judged whether the threshold value alpha ₂ or less, and variation _{V max} of the voltage value of the battery 15 Both determinations of whether -V _min is equal to or less than the threshold value α _v may be performed together (the third aspect is used).

This is done by carefully selecting the data in which the stable transition of the C rate value in the previous section is in the _{vicinity of zero [C] of the threshold value α 2} or less in the extraction of the data showing the transient response characteristics afterwards, so that the storage battery 15 can be used. This is because deterioration diagnosis can be performed with higher accuracy (details will be described later). Moreover, since the C-rate value varies the voltage value having a correlation with this the offset from zero [C], that is variation V _max -V _min voltage value carefully to that of the threshold alpha _v following small changes This is because the deterioration diagnosis of the storage battery 15 can be performed with higher accuracy. Further, by considering both of these, it is possible to perform the deterioration diagnosis of the storage battery 15 with higher accuracy.

Therefore, in step Sa, the magnitude of the C rate value | C _max | exceeds the threshold value α ₂ , or the fluctuation amount V _max −V _{min of the} voltage value exceeds the threshold value α _v, and both of them both exceed the threshold value α _2. , Α _v is exceeded (determination NO), the process is returned to step S1.

On the other hand, in step Sa, the magnitude of the C rate value | C _max | is the threshold value α ₂ or less, or the fluctuation of the voltage value V _max −V _min is the threshold value α _v or less, and both of them are the threshold _{values α 2} and α. _If it is determined to be v or less (determination YES), the process proceeds to step S6, and the data extraction process is the same as in the first embodiment. That is, it can be expected that the extracted data showing the transient response characteristics obtained by adding step Sa will be more carefully selected and desirable than after the first embodiment.

FIG. 15 shows the transient response analysis results based on the extracted data obtained by the data extraction process of the first embodiment for the samples of the three storage batteries 15 having different SOH showing the soundness (deterioration degree) of the storage batteries. ing. The sample 1 of the storage battery 15 having a small degree of deterioration has a variation x0 including the true value, the sample 2 of the storage battery 15 having a degree of deterioration has a variation y0 including the true value, and the sample 3 of the storage battery 15 having a high degree of deterioration has a variation z0 including the true value. Therefore, the variation in the extracted data obtained by the data extraction process of the first embodiment is sufficiently small.

On the other hand, FIG. 16 shows the transient response analysis result based on the extracted data obtained in the first aspect of the present embodiment, that is, _{the data extraction process in which the magnitude of the C rate value | C max} | is set to the threshold value α _{2 or less.} It is shown. The sample 1 of the storage battery 15 having a small degree of deterioration has a variation x1 including the true value, the sample 2 of the storage battery 15 having a degree of deterioration has a variation y1 including the true value, and the sample 3 of the storage battery 15 having a high degree of deterioration has a variation z1 including the true value. Therefore, the extraction data obtained by the data extraction process of the first embodiment of the present embodiment has even smaller variations based on the first embodiment, which has sufficiently small variations.

Further, FIG. 17 shows the second aspect of the present embodiment, that is, the transient response analysis result based on the extracted data obtained by the data extraction process in which _{the fluctuation amount V max} −V _{min of the} voltage value is set to the threshold value α _{v or less.} ing. The sample 1 of the storage battery 15 having a small degree of deterioration has a variation x2 including the true value, the sample 2 of the storage battery 15 having a degree of deterioration has a variation y2 including the true value, and the sample 3 of the storage battery 15 having a high degree of deterioration has a variation z2 including the true value. Therefore, the extracted data obtained by the data extraction process of the second embodiment of the present embodiment has a slightly smaller variation than the first embodiment, which has a sufficiently small variation.

Further, FIG. 18 shows the transient response analysis result based on the extracted data obtained through the determination of the third aspect of the present embodiment, that is, the first and second aspects. The sample 1 of the storage battery 15 having a small degree of deterioration has a variation x3 including the true value, the sample 2 of the storage battery 15 having a degree of deterioration has a variation y3 including the true value, and the sample 3 of the storage battery 15 having a high degree of deterioration has a variation z3 including the true value. Therefore, the extraction data obtained by the data extraction process of the third embodiment of the present embodiment has even smaller variations based on the first embodiment, which has sufficiently small variations.

The peculiar effect of this embodiment will be explained. The same effect as that of the first embodiment will be omitted.

(2-1) The extracted data obtained in the first to third aspects of the data extraction process of the present embodiment more desirablely defines the stable transition of the previous section, and is more desirable from the extracted data of the first embodiment. Is carefully selected. Therefore, it can be fully expected that the deterioration diagnosis of the storage battery 15 based on such extracted data will be performed with higher accuracy.

Each of the above embodiments can be changed and implemented as follows.

The time lengths of the times T ₁ to T ₅ and the values of the threshold values α, β, γ, α ₂ and α _v of each embodiment are examples and may be changed as appropriate.

-The data extraction process (processing flow) of each embodiment is an example and may be changed as appropriate. For example, the _{process related to the time T 2} such as step S4 may be omitted. It is also possible to omit the processing related to the time T _4, such as step S8. Further, in the case of the determination NO in step S10, the configuration proceeds to step S3, and steps S11 and S12 may be omitted. Further, in each embodiment, the processing is performed in the order of the front section, the fluctuation section, and the rear section, but the processing order is not limited to this, and for example, the processing of the fluctuation section may be performed first. .. Further, the times T ₁ to T ₅ include not only time counting by a timer but also time counting by counting the number of samplings.

-Although the data extraction process is performed based on the C rate value of the storage battery 15, it is possible to configure the same as the data extraction process of each embodiment by using the current value, the power value, etc. of the storage battery 15. ..

-Although it was applied to the deterioration diagnosis of the storage battery 15 attached to the photovoltaic power generation system 11, deterioration diagnosis of the storage battery attached to the distributed power source using renewable energy other than solar energy, peak cut / peak shift, self-consumption, etc. It may be applied to the deterioration diagnosis of the storage battery used for.

It will be clear to those skilled in the art that the present invention may be embodied in other peculiar forms as long as it does not deviate from the technical idea. For example, some of the configurations described in the embodiments (or one or more embodiments thereof) may be omitted, or some configurations may be combined. The scope of the invention should be established with reference to the appended claims, with the scope of the claims being established along with the full range of the equivalents to which the rights are granted.

11 ... Photovoltaic power generation system 12 ... Solar panel 13 ... Photovoltaic power conditioner 14 ... Storage battery system 15 ... Storage battery 16 ... Power conditioner for storage battery 17 ... Measuring instrument 18 ... Current meter 19 ... Voltage meter 20 ... Thermometer 21 ... Data extraction device 22 ... Storage unit 23 ... Data extraction unit 24 ... Battery deterioration diagnosis device 25 ... Equivalent circuit α ... Threshold (first threshold)
α ₂ … Threshold (4th threshold)
α _v ... Threshold (fifth threshold)
β ... Threshold (second threshold)
γ ... Threshold (third threshold)
T ₁ ... Time (1st hour)
T ₂ ... Time (5th hour)
T ₃ ... Time (2nd hour)
T ₄ ... Time (4th hour)
T ₅ ... Time (3rd hour)

Claims

A storage unit that stores detection value data that can diagnose deterioration of the storage battery at predetermined sampling intervals,
A storage battery data extraction device including a data extraction unit that extracts data related to the transient response of the storage battery from the detected value data stored in the storage unit.
The data extraction unit
It is divided into at least three sections: a variable section in which the C rate value or the current value or the power value suddenly changes based on the detected value of the storage battery, a section before the variable section, and a section after the variable section.
In the previous section, the determination of the stable transition of the previous section in which the fluctuation of the C rate value or the current value or the power value continues for the first hour or more at the first threshold value or less is determined.
In the fluctuation section, the determination of the sudden change transition of the fluctuation section in which the C rate value, the current value, or the power value fluctuates by the second threshold value or more within the second time is determined.
In the rear section, the determination of the stable transition of the rear section in which the fluctuation of the C rate value or the current value or the power value continues for the third time or more at the third threshold value or less is performed.
It is configured to extract the data related to the corresponding transient response from the storage unit when the data extraction conditions based on the respective determinations are satisfied.
Storage battery data extraction device.
The data extraction unit
Further, in the previous section, it is determined whether the magnitude of the C rate value, the current value, or the power value is equal to or less than the fourth threshold value, or
Further, in the previous section, it is determined whether or not the fluctuation of the voltage value based on the detected value of the storage battery is equal to or less than the fifth threshold value, or
It was configured to determine both,
The storage battery data extraction device according to claim 1.
The data extraction unit
In the fluctuation section, it is further configured to determine whether the sudden change in the C rate value, the current value, or the power value has converged within the fourth hour.
The storage battery data extraction device according to claim 1 or 2.
The data extraction unit
It is configured so that the local approximate transition that may occur near the change point of the C rate value or the current value or the power value in the fluctuation section is not erroneously determined as the stable transition in the subsequent section.
The storage battery data extraction device according to any one of claims 1 to 3.
The data extraction unit
Further, in the preceding section, it is determined whether the fluctuation of the C rate value, the current value, or the power value is within the fifth hour, and if the fluctuation exceeds the fifth hour, the first hour of the data stored in the storage unit is used. Configured to remove excess,
The storage battery data extraction device according to any one of claims 1 to 4.
The data extraction unit
Each determination is configured to be made based on the C rate value.
The storage battery data extraction device according to any one of claims 1 to 5.
A storage battery data extraction method in which detection value data capable of diagnosing deterioration of a storage battery is stored in a storage unit at predetermined sampling intervals, and data related to the transient response of the storage battery is extracted from the detection value data stored in the storage unit. hand,
It is divided into at least three sections: a variable section in which the C rate value or the current value or the power value suddenly changes based on the detected value of the storage battery, a section before the variable section, and a section after the variable section.
In the previous section, the stable transition of the previous section in which the fluctuation of the C rate value or the current value or the power value continues for the first hour or more at the first threshold value or less is determined.
In the fluctuation section, the sudden change transition of the fluctuation section in which the C rate value, the current value, or the power value fluctuates by the second threshold value or more within the second time is determined.
In the rear section, the stable transition of the rear section in which the fluctuation of the C rate value or the current value or the power value continues for the third time or more at the third threshold value or less is determined.
When the data extraction conditions based on the respective determinations are satisfied, the data related to the corresponding transient response is extracted from the storage unit.
Storage battery data extraction method.
Further, in the previous section, it is determined whether the magnitude of the C rate value, the current value, or the power value is equal to or less than the fourth threshold value, or
Further, in the previous section, it is determined whether or not the fluctuation of the voltage value based on the detected value of the storage battery is equal to or less than the fifth threshold value, or
Judging both,
The method for extracting data from a storage battery according to claim 7.