Battery data extraction device and battery data extraction method

Abstract

To provide a storage battery data extraction device and a storage battery data extraction method with which it is possible to extract many more data that are useful for the degradation diagnosis of storage batteries.SOLUTION: Data extraction pertaining to the degradation diagnosis of storage batteries involves determining detection value data in a change section (Tb) where a detection current value (I) suddenly changes and in a section Ta preceding it are data for analysis. In the preceding section, determination is made as to whether being a stable transition, with a change of the detection current value being equal to a threshold ΔIa or smaller and continuing for more than the preceding section. In the change section, a peak Ip of a change of the detection current value is set, and determination is made as whether being a rapid change transition, with a change of the detection current value to the peak changing by a threshold ΔIb or more within a change first section Tb1. After the peak onward, determination is made as to whether being a post-peak transition, with a constant change of the detection current value from the peak continuing for a change second section Tb2 or more within a change width equal to a threshold (ΔIs) or less, or with a decreasing change of the detection current value from the peak including an increasing change equal to a threshold (ΔIn) or less in the decreasing course and continuing for a change second section or more.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a battery data extraction device and a battery data extraction method for extracting data for performing battery degradation diagnosis. [Background technology]

[0002] The introduction of stationary battery storage systems is expanding, aimed at the effective use of renewable energy and power supply during disasters. Since batteries gradually degrade, understanding their current condition is crucial for the smooth operation of the system. Therefore, battery degradation assessments are being conducted.

[0003] One example of battery degradation diagnosis is a technique disclosed in, for example, Patent Document 1, which uses the transient response characteristics of a battery in operation. In the disclosed degradation diagnosis technique, detected data such as current when the battery exhibits predetermined transient response characteristics are extracted as analytical data, and degradation diagnosis is performed using the extracted analytical data. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-16991 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] One of the considerations for improving the accuracy of degradation diagnosis in the degradation diagnosis technology disclosed above is whether it can extract more data suitable for degradation diagnosis from the detected value data of the storage battery. In other words, the inventors have been investigating various methods that can extract more data useful for the degradation diagnosis of storage batteries. [Means for solving the problem]

[0006] A battery data extraction device that solves the above problems comprises a storage unit that continuously stores detected value data related to battery degradation diagnosis, and a data extraction unit that extracts useful analytical data from the detected value data continuously stored in the storage unit, wherein the data extraction unit divides the detected value, which is either the C-rate value, current value, or power value of the battery, into a fluctuating section and a section preceding the fluctuating section, and in the preceding section, it determines a stable trend in which the fluctuation of the detected value continues at or below a first threshold for one hour or more, and in the fluctuating section, it determines the detected value Along with setting the peak of the fluctuation, the system is configured to perform the following: a determination of a rapid change in the detected value up to the peak, where the fluctuation is greater than or equal to a second threshold within two hours; and a determination of a post-peak transition in which, after the peak, a constant fluctuation of the detected value from the peak continues for three hours or more within a fluctuation range of less than or equal to a third threshold, or a decrease in the detected value from the peak continues for four hours or more, including the allowance of an increase of less than or equal to a fourth threshold during the decrease process. Based on each of these determinations, the system is configured to extract the detected value data for a predetermined section including the preceding section and the fluctuation section from the storage unit as analysis data.

[0007] According to the above-described battery data extraction device, the data extraction unit divides the detected values ​​related to battery degradation diagnosis into a fluctuating section where the values ​​change abruptly and a section preceding the fluctuating section, and determines whether the detected value data for the preceding section and the fluctuating section are useful data for analysis. In the preceding section, it is determined whether the fluctuation of the detected value is stable, continuing for 1 hour or more at a level below the first threshold. In the fluctuating section, along with setting the peak of the fluctuation of the detected value, it is determined whether the fluctuation up to the peak of the detected value is abrupt, changing by more than the second threshold within 2 hours. After the peak, it is determined whether the constant fluctuation of the detected value from the peak continues for 3 hours or more within a fluctuation range of 3 thresholds or less, or whether the decrease in the detected value from the peak continues for 4 hours or more, including the allowance of an increase in fluctuation of 4 thresholds or less during the decrease process. Based on each determination, if the detected value data for the preceding section and the fluctuating section are determined to be useful data, the detected value data for a predetermined section including the preceding section and the fluctuating section is extracted from the storage unit as data for analysis. In other words, whether the battery detection data is useful for degradation diagnosis is determined by whether the fluctuation conditions in the fluctuation section where the battery detection value changes abruptly and in the preceding section are met. Furthermore, after the peak of the detection value in the fluctuation section, it is possible to determine whether the fluctuation conditions for the battery detection value are constant or decreasing, which is expected to increase the opportunities to extract useful data.

[0008] In the above-described battery data extraction device, the data extraction unit is configured to also use the reference detection value among the detection values ​​set as the basis for fluctuations within the preceding interval to determine the rapid change in the fluctuation interval.

[0009] According to the above configuration, the reference detection value among the detection values ​​set as the basis for fluctuations within the previous interval is also used to determine the rapid change in the fluctuation interval. Therefore, it is not necessary to set individual judgment values ​​for each interval, and the judgment can be simplified.

[0010] In the above-described data extraction device for the storage battery, the data extraction unit is configured to set the peak of the detected value as the peak of the detected value after the detected value has fluctuated to or above the provisional peak within 5 hours of setting the provisional peak.

[0011] According to the above configuration, the peak after the detected value has fluctuated above the provisional peak within 5 hours of setting the provisional peak in the fluctuation interval is set as the peak of the detected value. This is expected to ensure that the peak of the detected value is set appropriately, which will lead to appropriate data extraction.

[0012] In the above-described battery data extraction device, the battery from which the data extraction unit will extract data is a stationary battery. With the above configuration, since the data extraction target is a stationary battery, it is possible to suitably extract data related to the degradation diagnosis of a stationary battery.

[0013] A battery data extraction method that solves the above problems is a battery data extraction method which involves continuously storing detected value data related to battery degradation diagnosis in a storage unit and extracting useful analytical data from the detected value data continuously stored in the storage unit, and dividing the detected value, which is either the C-rate value, current value, or power value of the battery, into a fluctuation section where the value changes abruptly and a section preceding the fluctuation section, in the section preceding the fluctuation section, determining a stable transition in which the fluctuation of the detected value continues at or below a first threshold for one hour or more, setting a peak in the fluctuation of the detected value, and determining a rapid change transition in which the fluctuation of the detected value up to the peak changes at or above a second threshold within two hours, and determining a post-peak transition in which, after the peak, the constant fluctuation of the detected value from the peak continues at or below a third threshold for three hours or more, or the decreasing fluctuation of the detected value from the peak continues at or above a fourth threshold for four hours or more, including the allowance of increasing fluctuations of or below a fourth threshold during the decreasing process, and based on each of the above determinations, extracting the detected value data of a predetermined section including the section preceding the fluctuation section and the fluctuation section from the storage unit as analytical data.

[0014] According to the above-described battery data extraction method, similar to the above-described battery data extraction device, an increase in opportunities to extract useful data can be expected. [Effects of the Invention]

[0015] According to the battery data extraction device and battery data extraction method of the present invention, more data useful for diagnosing battery degradation can be extracted. [Brief explanation of the drawing]

[0016] [Figure 1] This is a diagram illustrating the overall system configuration for data extraction and degradation diagnosis of a storage battery in one embodiment. [Figure 2] This is a flowchart illustrating the data extraction process for the battery storage system in the same embodiment. [Figure 3] This is an explanatory diagram relating to data extraction from the battery of the same embodiment. [Figure 4] (a) and (b) are explanatory diagrams relating to data extraction from the battery of the same embodiment. [Figure 5] (a) to (d) are explanatory diagrams relating to data extraction from the battery of the same embodiment. [Figure 6] This table shows the advantages of data extraction from the battery in this embodiment. [Figure 7] This table shows the advantages of data extraction from the battery in this embodiment. [Modes for carrying out the invention]

[0017] The following describes the battery data extraction device and the battery data extraction method. [Overall configuration including a degradation diagnostic device 17 having a data extraction unit 20 for the storage battery 15] As shown in Figure 1, the renewable energy power generation facility 11 is, for example, a solar power generation facility, and is equipped with solar panels 12 and a solar power conditioner 13. The renewable energy power generation facility 11 is configured to convert the DC power generated by the solar panels 12 into commercial AC power using the solar power conditioner 13, and to supply the converted AC power to the power grid via the grid connection facility 10. The battery storage facility 14 is equipped with, for example, a battery 15 consisting of a stationary lithium-ion battery and a battery power conditioner 16. The battery storage facility 14 is installed adjacent to the renewable energy power generation facility 11. The battery storage facility 14 charges and discharges the battery 15 so that the rate of change of the output power of the renewable energy power generation facility 11, which can experience large fluctuations in power generation, is below a predetermined value, and suppresses output fluctuations to the power grid through power conversion by the battery power conditioner 16.

[0018] The degradation diagnosis device 17 is a device that performs degradation diagnosis on a battery 15 in operation. The degradation diagnosis device 17 comprises a measurement unit 18, a storage unit 19, a data extraction unit 20, and a degradation diagnosis unit 21.

[0019] The measurement unit 18 includes an ammeter 18a, a voltmeter 18b, a thermometer 18c, etc. The measurement unit 18 detects the charge and discharge current of the storage battery 15, the input and output voltages of the storage battery 15, and the temperature of the storage battery 15, and outputs each detection signal to the storage unit 19. The storage unit 19 continuously stores the detected values ​​of current, voltage, and temperature data acquired by sampling each detection signal from the measurement unit 18.

[0020] In this embodiment, the data extraction unit 20 extracts analysis data from each detected value data continuously stored in the storage unit 19, using the extraction condition that the current value of the storage battery 15 exceeds a predetermined current value. The data extraction unit 20 outputs the extracted analysis data along with time data to the degradation diagnosis unit 21. The degradation diagnosis unit 21 uses the analysis data extracted by the data extraction unit 20 to perform an equivalent circuit analysis, for example, using the transient response characteristics of the storage battery 15 in this embodiment. Then, the degradation diagnosis unit 21 diagnoses the degradation state of the storage battery 15 based on the analysis.

[0021] [Details of data extraction from battery 15] The data extraction process in this embodiment is performed according to the flow shown in Figure 2. In step S11, as part of the measurement and data extraction start point search, the current value, voltage value, and temperature of the battery 15 measured by the measurement unit 18 are stored as continuous data in the storage unit 19. The data extraction unit 20 searches for a data extraction start point from the continuous current value data to be extracted as analysis data for use in the degradation diagnosis unit 21.

[0022] Incidentally, the current value used in this process is the "C-rate value". The C-rate value [C] is a relative expression of the magnitude of the current value, and is expressed as current value [A] / battery capacity [Ah]. In other words, it is a parameter that can be used in common for storage batteries 15 with different battery capacities. This process proceeds to step S12.

[0023] In step S12, the detected current value I (absolute value in this case |I|) and the determination current value I shown in Figure 3 are determined. a0 The extraction starting point is searched by comparison with the following. Since the detected current value I changes between positive and negative, the absolute value |I| is used to determine the current value I. a0 This will be compared to the following. The determination current value I used to detect the data extraction start point. a0 For example, it is set to 0 to 0.1 [C]. The absolute value |I| of the detected current value I is equal to the judgment current value I a0 If it is greater than (|I|>I a0) This process returns to step S11. On the other hand, when the absolute value |I| of the detected current value I becomes less than or equal to the determination current value I a0 (|I| ≤ I a0 ), this process proceeds to the next step S13.

[0024] In step S13, assuming that the detected current value I has started to transition stably, as shown in FIG. 3, the time a0 when |I| ≤ I a0 is set. At time a0, the detected current value I when |I| ≤ I a0 is set as the reference current value I a . Also, the time counting of the previous interval T a is performed from time a0. The previous interval T a is set as an interval for looking at the stable transition before the variable interval T b where the detected current value I changes significantly, in order to obtain the desired transient response characteristics of the storage battery 15. The previous interval T a is set to, for example, 1 to 100 [s]. This process proceeds to step S14.

[0025] In step S14, it is determined whether the current change amount ΔI of the detected current value I at each time with respect to the reference current value I a at time a0 is less than or equal to the threshold value ΔI a and continues for a period equal to or greater than the previous interval T a . The threshold value ΔI a is set to, for example, 0 to 0.1 [C]. Here, it is determined whether the detected current value I at each time has a desired stable transition. If the current change amount ΔI of the detected current value I becomes greater than the threshold value ΔI a within the previous interval T a , this process returns to step S11. On the other hand, as shown in FIG. 3, if the current change amount ΔI of the detected current value I is within the threshold value ΔI a and continues for a period equal to or greater than the previous interval T a , that is, if the current change amount ΔI becomes greater than the threshold value ΔI a after the previous interval T a becomes equal to or greater than a certain value, this process proceeds to the next step S15.

[0026] In step S15, the current change amount ΔI of the detected current value I is the threshold value ΔI aThe time immediately preceding the larger time interval is set as time ab. Time ab is set in the previous interval T a and the next fluctuation interval T b This marks the boundary point. Time measurement begins from time ab, and first the variable interval T b The first half of the variation is the first variation section T. b1 The timing will begin. Variable first section T b1 This is set to, for example, 1 to 100 [s]. Variation 1st interval T b1 Peak I of detected current value I within p A search is performed. In this case, the first variable interval T b1 Within the above reference current value I a The detection current value I with the largest variation from is at its peak I. p It is selected as such. This process proceeds to step S16. Incidentally, the variable interval T b This is the first variable interval T b1 and the second fluctuation section T described later b2 This is the sum of the values, and the variation interval T b It is not specifically set as such.

[0027] In step S16, the first variable interval T b1 The peak I of the detected current value I within p The above reference current value I a From threshold ΔI b The system determines whether the above changes have occurred. Reference current value I a From vertex I p The current change ΔI of the detected current value I, in this case the current change ΔI with the changing side being positive, and the threshold ΔI. b The two are compared. Threshold ΔI b This is set to, for example, 0.1 to 1.0 [C]. Here, it is determined whether a desired abrupt change in the detected current value I has occurred. Reference current value I a From vertex I p The change in current ΔI is the threshold ΔI b If it is less than, this process returns to step S11. On the other hand, as shown in Figure 3, the reference current value I a From vertex I p The change in current ΔI is the threshold ΔI b If the above conditions are met, the process proceeds to the next step, S17.

[0028] In step S17, the peak I of the detected current value I p Setting and vertex I p Along with setting the time p, the second variable interval T starts from time p. b2 The timekeeping begins. Variable second interval T b2 This is set to, for example, 1 to 100 [s]. This process proceeds to the next step, S18.

[0029] In step S18, vertex I p Subsequent fluctuations in the second period T b2 It is determined whether the detected current value I has undergone the desired fluctuation, and the first fluctuation interval T is determined. b1 Together with the variable interval T b It is determined whether the conditions for variation of the detected current value I are met. p The determination of this embodiment from this point forward is as follows.

[0030] Figure 4(a) shows vertex I p The following is an example of how to determine the case when the detected current value I fluctuates in a step-like manner. Figure 4(b) is an example of how to determine the case when the fluctuation is not in a step-like manner. In Figures 4(a) and 4(b), the side in which the detected current value I fluctuates during charging or discharging is both considered positive. Peak I p From here on, vertex I p The current change ΔI of the detected current value I, based on the reference, fluctuates in the second interval T. b2 In the threshold ΔI s If the following trend remains approximately constant, it is determined to be the desired variation of the step waveform as shown in Figure 4(a). Threshold ΔI s This is set to, for example, 0 to 0.1 [C]. The desired variation of the step waveform shown in Figure 4(a) is the variation interval T b This is one of the conditions for satisfying the variation of the detected current value I.

[0031] Also, vertex I p From here on, vertex I p The variation from the above threshold ΔI s If it exceeds and then gradually begins to decrease, then the current change amount ΔI and the threshold ΔI for each detected current value I are determined. nis compared. The amount of current change ΔI at each time is the amount of change in current for each predetermined sampling. The peak current I p After that, if the amount of current change ΔI at each time includes an increase fluctuation below the threshold value ΔI n and shows a substantially decreasing trend in the second variation interval T b2 , it is determined as a desired variation other than the step waveform as shown in Fig. 4(b). The threshold value ΔI n is set to, for example, 0 to 0.1 [C]. The desired variation other than the step waveform as shown in Fig. 4(b) is another variation satisfaction condition of the detected current value I in the variation interval T b .

[0032] Note that, similarly for Fig. 5(a), after the peak current I p is set, if the amount of current change ΔI at each time of the detected current value I includes an increase fluctuation below the threshold value ΔI n and shows a decreasing trend in the second variation interval T b2 , it is shown. That is, it is a mode in which the detected current value I is desired to vary in the second variation interval T b2 . Therefore, when it is determined that the variation condition of the detected current value I as the variation interval T b is satisfied, this process proceeds to the next step S19.

[0033] In contrast, Fig. 5(b) shows a mode in which the amount of current change ΔI at each time during the second variation interval T a0 4>increases more than the threshold value ΔI n . Therefore, since the detected current value I does not vary as desired in the second variation interval T b2 , it is determined that the variation condition is not satisfied, and this process returns to step S11.

[0034] Although the explanation is in reverse order, Figs. 5(c) and (d) show supplements regarding the setting of the peak current I p of the detected current value I. In the mode of Fig. 5(c) where the detected current value I varies again above the temporary peak current I re within the allowable inversion time T re after the temporary peak current I re of the detected current value I occurs, the temporary peak current I re is the peak current I pis not set. This vertex setting process is performed within the above-mentioned first variable section T b1 and is repeated. The true vertex I of the detected current value I p is set. As shown in the aspect of FIG. 5(d), if the detected current value I does not change to be equal to or greater than the temporary vertex I re within the inversion tolerance time T and then changes to be equal to or greater than the temporary vertex I re , the vertex I re is not set. The aspects shown in FIGS. 5(c) and 5(d) are examples of the setting of the vertex I of the detected current value I p . p

[0035] In step S19, the time when the variation condition of the detected current value I in the second variable section T b2 , that is, the variation section T b is satisfied is set as the time end. The section from the time a0 to the time end is determined as the data extraction section.

[0036] Then, the detected value data of the detected current value I from the time a0 to the time end is useful data that has passed through the above steps S12 to S18, and is extracted from the data extraction unit 20 as analysis data. The extracted analysis data is used for the degradation diagnosis of the storage battery 15 by transient response analysis or the like in the degradation diagnosis unit 21. Such a series of data extraction processes repeats steps S11 to S19 until the process stops.

[0037] [Operation of the Present Embodiment] The operation of the present embodiment will be described. FIG. 6 is an example of a comparison result regarding the data extraction frequency by the data extraction processes of the present invention and the comparative example. In FIG. 6, Case 1 and Case 2 are those in which the renewable energy power generation facility 11 is a solar power generation facility, and Case 3 is a wind power generation facility. Each of Cases 1 to 3 is the result of simulating the data extraction frequency when operated for one year. The data extraction process of the present invention is, as described above, the front section T shown in FIG. 3 a and the variation section T b ​This involves data extraction based on the fluctuation conditions of the detected current value I. In the data extraction process of this proposal, data extraction is performed monthly and throughout the year in all three cases (1 to 3). Case 1 has the highest data extraction frequency, while Case 3 has the lowest.

[0038] In contrast, the data extraction process for the comparative example is performed in the previous interval T a and fluctuation interval T b In addition, the post-interval T shown in Figure 3 c This is data extraction based on the fluctuation conditions of the detected current value I, including the following interval T. c The conditions for variation of the detected current value I are as follows: a Similarly, it is required that the data remains stable near zero. In the comparative example's data extraction process, the trend in data extraction frequency for each case 1 to 3 was the same as in the present invention, with case 1 having the most data extractions and case 3 having the fewest. Within that, in case 1, data extraction was performed every month and throughout the year, but in cases 2 and 3, there were months in which no data was extracted. In particular, in case 3, there were five months in which no data was extracted. The comparative example's data extraction process is inferior when considering only the opportunities for data extraction of the battery 15, and thus the opportunities for degradation diagnosis.

[0039] Figure 7 shows an example of the comparison results of a simulated degradation diagnosis performed based on data extracted in Case 3 of both the present invention and the comparative example. The number of data points extracted for the present invention was "91," and the number of data points extracted for the comparative example was "12." Transient response analysis was performed using two charge-discharge cycles. The average values ​​of the analysis values ​​for both the present invention and the comparative example were assumed to be the true values, and their respective relative errors are shown in Figure 7.

[0040] In the comparative example, the relative error in the analysis was "within 7%" for the first run and "within 5%" for the second run, indicating extremely high analytical accuracy. However, as mentioned above, the number of data points extracted was small.

[0041] In contrast, the present proposal achieves a relative error of "within 10%" in the first run (with the exception of one case) and "within 9%" in the second run. While the analytical accuracy is slightly lower than that of the comparative example, it can still be considered sufficiently high. In addition, as mentioned above, it is possible to secure a large number of data points. Given the large number of data points and the expectation of sufficiently high analytical accuracy, the present proposal can be said to consistently demonstrate high analytical accuracy.

[0042] [Effects of this embodiment] The effects of this embodiment will now be explained. (1) The data extraction unit 20 detects a sudden change in the fluctuating interval T related to the degradation diagnosis of the storage battery 15. b and the fluctuating interval T b Previous section T a Divided into two, the previous section T a and fluctuation interval T b Determine whether the detected data for the previous interval T is useful for analysis. a So, the variation (ΔI) of the detected current value I is the threshold ΔI a The previous section T is below a The determination is made as to whether the trend remains stable. (Fluctuation interval T) b So, the peak of variation in the detected current value I is I p Along with the setting, the peak I of the detected current value I p The fluctuations up to that point constitute the first fluctuation interval T. b1 Within the threshold ΔI b The determination is made as to whether the change is a sudden fluctuation of the above magnitude. Peak I p From this point onward, vertex I p The constant fluctuation of the detected current value I is the threshold ΔI s The following fluctuation range applies to the second fluctuation section T. b2 It is determined whether the transition after the peak continues as described above. Alternatively, if the peak I p The decrease in the detected current value I is the threshold ΔI during the decrease process. n The following allowance for increasing fluctuations is included in the second fluctuation interval T. b2 The system then determines whether the transition after the peak continues as described above. Based on these determinations, the previous interval T is then determined. a and fluctuation interval T b If the detected data for the previous interval T is determined to be useful data, a and fluctuation interval T bThe detected value data for a predetermined interval (in this embodiment, the interval from time a0 to time end) including the variable interval T is extracted from the storage unit 19 as data for analysis. In other words, the determination of whether the detected value data of the storage battery 15 is useful for deterioration diagnosis is made based on the variable interval T in which the detected current value I of the storage battery 15 changes abruptly. b and the previous section T a The test is conducted to determine if the conditions for variation are met in the variation interval T. b The peak of the detected current value I p From this point forward, since the fluctuation conditions of the detected current value I of the storage battery 15 can be determined to be either constant fluctuation or decreasing fluctuation, a significant increase in opportunities to extract useful data can be expected.

[0043] Note that the threshold ΔI a The first threshold is the threshold ΔI b This is the second threshold, threshold ΔI s This is the third threshold, threshold ΔI n These correspond to the fourth threshold, respectively. Also, the previous interval T a This is the first hour, variable first section T b1 This is the second hour, variable second section T b2 These correspond to the third and fourth hours, respectively.

[0044] (2) Previous section T a The reference current value I of the detected current value I set as the basis for fluctuation within the system a The variable interval T b It is also used to determine sudden changes in the preceding interval T. a and fluctuation interval T b It is not necessary to set the judgment value individually for each case, and the judgment can be simplified. a This corresponds to the standard detection value.

[0045] (3) Variable section T b Temporary vertex I re The setting allows for a reversal time T. re Within a certain time, the detected current value I will return to the false peak I re The peak after the above fluctuation is the peak of the detected current value I. p It is set as the peak I of the detected current value I. pThis is expected to allow for proper configuration and lead to proper data extraction. Note that the inversion tolerance time T is also important. re This corresponds to the fifth hour.

[0046] (4) Since the battery 15 from which data is extracted in this embodiment is a stationary lithium-ion battery, data extraction related to the degradation diagnosis of the stationary battery can be performed suitably as in this embodiment.

[0047] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0048] The various numerical values ​​listed above are examples only and may be changed as appropriate. • Although the C-rate value [C] was used for the current value, the current value itself [A] may also be used. Alternatively, a power value that includes the current value may be used.

[0049] • While current values ​​were used for each determination, voltage values ​​may also be considered. Furthermore, ambient temperature, noise, etc., may also be taken into account during the determination process. • Transient response analysis associated with charging and discharging was used to diagnose the degradation of the storage battery 15, but various other analytical methods capable of diagnosing the degradation of the storage battery 15 may also be used.

[0050] The data extraction process shown in Figure 2 is just one example and may be modified as needed. • Time measurement includes not only timer-based measurement but also measurement by counting the number of samples, etc. The battery storage system 15 was installed alongside the renewable energy power generation facility 11, which consists of a solar power generation system, but it may be installed in a facility other than a solar power generation system. Also, the battery storage system 15 may be installed in a facility other than a stationary battery storage system.

[0051] [Note] The technical concepts that can be understood from the above embodiments and modified examples are described below. (i) A battery degradation diagnostic device equipped with a degradation diagnostic unit that performs a degradation diagnosis of the battery based on the analysis data extracted by the data extraction unit.

[0052] (b) A battery degradation diagnosis method that performs a battery degradation diagnosis based on extracted analytical data. According to the above-described battery degradation diagnostic device and battery degradation diagnostic method, an increase in opportunities to extract useful data can be expected, and therefore, a consistently high level of degradation diagnostic accuracy can be expected. [Explanation of Symbols]

[0053] 15…Battery storage 19...Storage section 20...Data extraction unit (data extraction device) I...Detected current value (detected value) I a ...Reference current value (reference detection value) I p …vertex I re ... false vertex ΔI a ...threshold (first threshold) ΔI b ...threshold (second threshold) ΔI s ...threshold (third threshold) ΔI n ...threshold (fourth threshold) T a ...Previous section (1st hour) T b ...variable section T b1 ...Variation Section 1 (2nd hour) T b2 ...Fluctuating second period (3rd and 4th hours) T re ...Reversal allowance time (5th hour)

Claims

1. A storage unit that continuously stores detection value data related to battery degradation diagnosis, A data extraction device for a storage battery, comprising: a data extraction unit for extracting useful analytical data from the detected value data continuously stored in the storage unit; The data extraction unit divides the data into a fluctuating section in which the detected value, which is either the C-rate value, current value, or power value of the storage battery, changes abruptly, and the section preceding the fluctuating section. In the preceding section, a stable trend is determined in which the fluctuation of the detected value remains below the first threshold for one hour or more, In the aforementioned fluctuation interval, along with setting the peak of the fluctuation of the detected value, a determination is made of a rapid change in the fluctuation of the detected value up to the peak, where the fluctuation is greater than or equal to the second threshold within two hours, and a determination is made of a post-peak transition in the interval from the time of the peak, where a constant fluctuation of the detected value from the peak continues for three hours or more within a fluctuation range of less than or equal to the third threshold, or where a decrease in the detected value from the peak continues for four hours or more, including the allowance of an increase of less than or equal to the fourth threshold during the decrease process. Based on the above determinations, the system is configured to extract the detected value data for a predetermined interval including the preceding interval and the fluctuation interval from the storage unit as analysis data. Battery data extraction device.

2. The data extraction unit, The system is configured to also use the reference detection value among the detection values ​​set as the basis for fluctuations within the aforementioned interval for determining the rapid change in the fluctuation interval. A data extraction device for a storage battery according to claim 1.

3. The data extraction unit, When setting the peak of the detected value in the aforementioned fluctuation interval, the system is configured to set the peak of the detected value as the peak after the detected value has fluctuated to or exceeded the provisional peak again within 5 hours of setting the provisional peak. A data extraction device for a storage battery according to claim 1 or claim 2.

4. The battery from which the data extraction unit extracts data is a stationary battery. A battery data extraction device according to any one of claims 1 to 3.

5. The detected value data related to the degradation diagnosis of the storage battery is continuously stored in the storage unit. A data extraction method for a storage battery, comprising extracting useful analytical data from the detected value data continuously stored in the storage unit, The system is divided into a fluctuating section where the detected value, which is either the C-rate value, current value, or power value of the aforementioned battery, changes abruptly, and the section preceding the fluctuating section. In the preceding section, a stable trend is determined in which the fluctuation of the detected value remains below the first threshold for one hour or more. In the aforementioned fluctuation interval, along with setting the peak of the fluctuation of the detected value, a rapid change in the fluctuation of the detected value up to the peak is determined to occur if the fluctuation is greater than or equal to the second threshold within two hours, and in the interval from the time of the peak when time measurement begins, a post-peak change is determined if the constant fluctuation of the detected value from the peak continues for three hours or more within a fluctuation range of less than or equal to the third threshold, or if the decreasing fluctuation of the detected value from the peak continues for four hours or more, including the allowance of an increasing fluctuation of less than or equal to the fourth threshold during the decreasing process. Based on the above determinations, the detected value data for a predetermined interval including the preceding interval and the fluctuating interval is extracted from the storage unit as the data for analysis. Method for extracting data from a battery storage system.

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