Storage battery deterioration detection device, storage battery deterioration detection method, and storage battery deterioration detection program

Abstract

To provide a storage battery deterioration detection device for more accurately and easily detecting the degree of deterioration of a storage battery even from limited data.SOLUTION: A storage battery degradation detection device according to an embodiment includes an acquisition unit that acquires battery state information that can be used for degradation estimation of a storage battery from a storage battery system in which a plurality of storage batteries are connected in parallel, the storage battery system including a plurality of storage batteries connected in series, a calculation unit that detects identification information of a storage battery satisfying a predetermined state condition in the battery state information for each predetermined period and calculates an identification integrated value obtained by integrating the number of detections for each identification information, and a determination unit that determines that a storage battery having a large identification integrated value for each identification information has a higher degradation level than a storage battery having a small identification integrated value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a storage battery deterioration detection device, a storage battery deterioration detection method, and a storage battery deterioration detection program. [Background technology]

[0002] Conventionally, rechargeable battery systems have been known. Storage batteries, the smallest unit of a storage battery system, deteriorate over time, sometimes resulting in a decline in their storage capacity. Furthermore, the rate of deterioration can vary depending on the temperature environment during use and individual differences. Therefore, when operating a storage battery system, understanding the degree of deterioration of each individual battery is important for the control and maintenance of the system. In this case, the degree of deterioration can be calculated if detailed data (e.g., current, voltage, and temperature) of the target battery can be acquired. Various technologies have been proposed to process large amounts of data and detect malfunctioning equipment. For example, a technology has been proposed for detecting discrepancies between the settings and operating status information of equipment installed in railway vehicles and detecting malfunctions based on the number of such discrepancies. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5112766 Summary of the Invention [Problem to be solved by the invention]

[0004] When a battery storage system is small-scale, it is easy to obtain data from all the batteries. However, when the battery storage system is large-scale, or when data is sent to and stored on a cloud server for remote monitoring, it is expected that only aggregated data (maximum and minimum values, etc.) can be obtained in order to reduce recording capacity and data communication volume. In such cases, it is difficult to accurately grasp the deterioration level of all the batteries.

[0005] Therefore, if a technology could be provided that could more accurately and easily detect the degree of deterioration of a storage battery even from limited data, it would be useful as it would make it easier to operate the storage battery system smoothly and appropriately. [Means for solving the problem]

[0006] A storage battery deterioration detection device according to an embodiment includes an acquisition unit, a calculation unit, and a determination unit. The acquisition unit acquires battery state information for each predetermined period from a storage battery system in which a plurality of storage battery units, each configured by connecting a plurality of storage batteries in series, are connected in parallel and can be used to estimate deterioration of the storage batteries. The calculation unit detects, from the battery state information, identification information of the storage batteries that satisfy a predetermined state condition for each predetermined period, and calculates an identification integrated value by accumulating the number of times each piece of identification information has been detected. The determination unit determines that a storage battery with a larger identification integrated value for each piece of identification information has a higher level of deterioration than a storage battery with a smaller identification integrated value. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an exemplary schematic system diagram showing a storage battery system to which a storage battery deterioration detection device according to an embodiment can be applied. [Figure 2] FIG. 2 is an exemplary schematic explanatory diagram showing differences in the number of data (amount of data) due to differences in data aggregation in a storage battery system to which a battery deterioration detection device according to an embodiment can be applied. [Figure 3] FIG. 3 is an exemplary schematic explanatory diagram showing the behavior of a storage battery to which the storage battery deterioration detection device according to the embodiment can be applied. [Figure 4] FIG. 4 is an exemplary schematic block diagram illustrating the configuration of a storage battery deterioration detection device according to an embodiment. [Figure 5] FIG. 5 is an exemplary schematic explanatory diagram showing a process of extracting a deteriorated battery when two battery units are connected in series to which a battery deterioration detection device according to an embodiment is applied. [Figure 6] FIG. 6 is an exemplary schematic explanatory diagram showing a process of extracting a deteriorated battery when two battery units are connected in series to which a battery deterioration detection device according to an embodiment is applied. [Figure 7] FIG. 7 is an exemplary schematic explanatory diagram showing a process of extracting a degraded battery based on a battery temperature value or the sum of a battery temperature value and a maximum battery voltage value in a storage battery degradation detection device according to an embodiment. [Figure 8] FIG. 8 is an exemplary schematic explanatory diagram showing the relationship between the maximum battery voltage value and the average voltage value in the storage battery deterioration detection device according to the embodiment. [Figure 9] FIG. 9 is an exemplary schematic explanatory diagram showing data and calculation examples when a degraded battery is extracted based on a maximum battery voltage value and an average voltage value in a storage battery degradation detection device according to an embodiment. [Figure 10] FIG. 10 is an exemplary schematic explanatory diagram showing data and calculation examples when a degraded battery is extracted based on a normalized average voltage difference value in a storage battery degradation detection device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a storage battery deterioration detection device, a storage battery deterioration detection method, and a storage battery deterioration detection program according to the present invention will be described with reference to the drawings.

[0009] 1 is an exemplary schematic system diagram showing a storage battery system to which a storage battery deterioration detection device 10 according to an embodiment can be applied. The storage battery system S to which the storage battery deterioration detection device 10 according to the present embodiment is applied is assumed to be a large-scale storage battery system.

[0010] First, the configuration of the storage battery system S will be described.

[0011] The smallest unit constituting the storage battery system S is the storage battery 12. A plurality of storage batteries 12 are connected in series to form a storage battery unit 14. Furthermore, a plurality of storage battery units 14 are connected in parallel to form the storage battery system S. In the example of FIG. 1, the storage battery units 14 are shown as, for example, m storage batteries 12 connected in series. Each storage battery 12 is assigned identification information for individual identification. The identification information is indicated, for example, as (1,1), (1,2), ... (1,m-1), (1,m), or (2,1), (2,2), ... (2,m-1), (2,m), etc. For example, (1,1) indicates unit number 1 and battery number 1. Similarly, for example, (2,1) indicates unit number 2 and battery number 1. The storage battery system S is constituted by two or more storage battery units 14 connected in parallel. In the case of FIG. 1, for convenience of illustration, an example in which two storage battery units 14 are connected in parallel is shown, but in reality, three or more storage battery units 14 may be connected in parallel. In the following description, (1, 1) etc. will refer to storage battery 12. (1,1) When the subscripts are used, such as "unit number 1", "battery number 1", "unit number 2", "battery number 3", "unit number 4", "unit number 5", "battery number 6", "unit number 7", "unit number 8", "unit number 9", "unit number 10", "unit number 11", "unit number 12", "unit number 12", "battery number 12", "unit number 11", "unit number 12",

[0012] A BMU (Battery Management Unit) 16 is connected to each storage battery unit 14. The BMU 16 detects (monitors) battery status information, such as the battery voltage value, battery temperature value, and unit current value flowing through the storage battery unit 14 of each storage battery 12. The BMU 16 detects battery status information at predetermined intervals, for example, and provides the battery status information, with identification information attached, to the battery deterioration detection device 10 sequentially or at predetermined timing.

[0013] FIG. 2 is an exemplary schematic explanatory diagram showing differences in the number of data (data amount) due to differences in data aggregation in a storage battery system S to which a storage battery deterioration detection device 10 according to an embodiment can be applied.

[0014] First, the battery data group for the storage batteries 12 that are not aggregated is shown by the dashed-dotted line R1 on the left side of FIG. 2. In this case, there are as many data items as there are battery voltage values ​​(n, m) and battery temperature values ​​(n, m) for the number of storage batteries 12, and as many data items as there are unit voltage values ​​(n) and unit current values ​​(n) for the number of storage battery units 14. Note that n is the unit number (number of units), and m is the storage battery number (number of storage batteries). That is, in this case, the number of data items is n × (m + 2). In this case, it is possible to refer to the data for all storage batteries 12, making it possible to grasp the degree of deterioration of all storage batteries 12. On the other hand, the amount of data handled is enormous, which results in an increase in the required capacity of the storage device for storing the data and an increase in the amount of communication required for processing.

[0015] Next, the group of aggregated battery data of the storage battery 12 is indicated by a dashed line R2 in the center of Fig. 2. In this case, the battery data (battery state information) for the storage battery unit 14 is aggregated as follows: Maximum battery voltage value (n): The maximum value among the battery voltage values ​​of each storage battery 12 Maximum voltage battery number (n): The battery number of the storage battery 12 with the maximum battery voltage value Minimum battery voltage value (n): the minimum value among the battery voltage values ​​of each storage battery 12 Minimum voltage battery number (n): the battery number of the storage battery 12 with the minimum battery voltage value Highest battery temperature value (n): The highest battery temperature value among the battery temperatures of each storage battery 12 Highest temperature battery number (n): The battery number of the battery 12 with the highest battery temperature value Minimum battery temperature value (n): the minimum battery temperature value of each storage battery 12 Lowest temperature battery number (n): the battery number of the storage battery 12 with the lowest battery temperature value If the unit voltage value (n) and unit current value (n) are added to the above eight items, the number of data items becomes n × 10. Therefore, compared to the case where data is not aggregated, if the number of storage batteries 12 is m > 8, the number of data items is reduced. Even with the aggregated number of data items, the degree of deterioration of all storage batteries 12 can be determined.

[0016] Next, the further aggregated battery data group of the storage battery 12 is shown by the dashed-dotted line R3 on the right side of Fig. 2. In this case, for the storage battery unit 14, the unit current value (n), maximum voltage battery number (n), minimum voltage battery number (n), maximum temperature battery number (n), and minimum temperature battery number (n) are the aggregated battery data (battery state information), and the number of data items is n x 5.

[0017] 3 is an exemplary schematic explanatory diagram showing the behavior of a storage battery 12 to which a storage battery deterioration detection device 10 according to an embodiment can be applied. In the case of FIG. 3, current begins to flow and charging begins at time t1.

[0018] When the storage battery 12 is being charged, a voltage rise ΔV occurs compared to the battery voltage value (open circuit voltage: OCV) when no current is flowing. If the current value flowing through the storage battery 12 is I (+ is charging, - is discharging) and the internal resistance of the battery is R, the voltage rise ΔV can be expressed as ΔV = I × R. Therefore, the battery voltage value (closed circuit voltage: CCV) when charging can be expressed as follows: CCV=OCV+ΔV=OCV+I×R When the storage battery 12 deteriorates, the internal resistance R increases, and therefore the CCV also increases.

[0019] In this case, the storage battery 12 exhibiting the maximum battery voltage value is determined to satisfy a predetermined condition, and its identification information is detected. An integrated identification value is calculated by integrating the number of detections for each identification information. In other words, when charging, the maximum voltage battery number is acquired as identification information for identifying the storage battery 12 exhibiting the maximum battery voltage value, and an integrated identification value is calculated by integrating the number of detections for the maximum voltage battery number. In this case, the larger the integrated value, the more deteriorated the storage battery 12 is determined to be. The accuracy of detection may vary depending on the cycle (detection time) used to detect the maximum battery voltage value. Therefore, when integrating the number of detections for each identification information, the number of seconds (predetermined cycle value: for example, 1 second) corresponding to the maximum voltage battery number is integrated (counted) for each battery number. The larger the integrated value, the more deteriorated the storage battery 12 is determined to be.

[0020] For example, when the storage battery 12 is being discharged, a voltage drop ΔV occurs, and as the storage battery 12 deteriorates, the CCV also decreases. Therefore, during discharge, the number of seconds (predetermined cycle value: for example, 1 second) corresponding to the minimum voltage battery number is integrated (counted) for each battery number. The larger the integrated value, the more deteriorated the storage battery 12 can be determined to be.

[0021] Next, a specific method (process) for detecting deterioration of the storage battery 12 will be described with reference to Figures 4 to 6. Figure 4 is an exemplary schematic block diagram showing the configuration of a storage battery deterioration detection device 10 according to an embodiment. Figures 5 and 6 are exemplary schematic explanatory diagrams showing the process of extracting a deteriorated battery when the storage battery units 14 to which the storage battery deterioration detection device 10 is applied are connected in series in two cases.

[0022] The battery deterioration detection device 10 can be configured with, for example, general computer resources. The battery deterioration detection device 10 is configured with, for example, a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and a storage unit such as a hard disk drive (HDD) or solid-state drive (SSD). In the battery deterioration detection device 10, the CPU reads a battery deterioration detection program installed and stored in a non-volatile storage unit such as a ROM or SSD, and implements various modules that function in the battery deterioration detection device 10 in accordance with the battery deterioration detection program. In the battery deterioration detection device 10, modules such as an acquisition unit 18, a calculation unit 20, and a determination unit 22 are implemented. Note that some or all of these modules may be implemented as dedicated hardware.

[0023] The acquisition unit 18 acquires battery state information for each predetermined period from a storage battery system S in which a plurality of storage battery units 14, each configured by connecting a plurality of storage batteries 12 in series, are connected in parallel. The battery state information can be used to estimate deterioration of the storage batteries 12. As described above, the battery state information is aggregated battery information, and is transmitted via the BMU 16, for example, to the unit voltage value (n), maximum voltage battery number (n), minimum voltage battery number (n), maximum temperature battery number (n), and minimum temperature battery number (n), for each storage battery 12. The acquisition unit 18 may temporarily store the acquired battery state information in a storage unit such as an HDD or SSD and provide it to the calculation unit 20 at a predetermined processing timing, or may provide the acquired battery state information to the calculation unit 20 sequentially.

[0024] The calculation unit 20 detects, at predetermined intervals, the identification information of the storage battery 12 that satisfies predetermined state conditions from the battery state information provided by the acquisition unit 18, and calculates an identification integrated value by integrating the number of times each piece of identification information is detected. For example, if the state condition is the maximum voltage value during charging, the calculation unit 20 integrates (counts) the number of seconds (predetermined period value: for example, 1 second) corresponding to the maximum voltage battery number for each battery number.

[0025] The calculation unit 20 includes, as detailed modules, a voltage processing unit 24, a temperature processing unit 26, an identification processing unit 28, an average voltage value calculation unit 30, a differential voltage value calculation unit 32, an average voltage difference value calculation unit 34, a normalized difference calculation unit 36, a dead band processing unit 38, etc.

[0026] The voltage processing unit 24 processes information related to voltage from the battery state information provided by the acquisition unit 18. For example, when the state condition is the maximum voltage value during charging, the voltage processing unit 24 extracts identification information (such as a battery number) of the storage battery 12 that indicates the maximum voltage value from the battery state information provided by the acquisition unit 18. When the state condition is the minimum voltage value during discharging, the voltage processing unit 24 extracts identification information (such as a battery number) of the storage battery 12 that indicates the minimum voltage value from the battery state information provided by the acquisition unit 18.

[0027] The temperature processing unit 26 processes information related to the battery temperature value from the battery state information provided by the acquisition unit 18. For example, when the state condition is battery temperature, the temperature processing unit 26 extracts identification information (such as a battery number) of the storage battery 12 that exhibits the highest battery temperature value from the battery state information provided by the acquisition unit 18. The temperature processing unit 26 extracts identification information of the storage battery 12 that exhibits the highest battery temperature value, regardless of whether the storage battery 12 is being charged or discharged.

[0028] The identification processing unit 28 calculates an identification integrated value by integrating the number of detections for each piece of identification information. The identification processing unit 28 includes detailed modules such as a first identification integrator 28a, a second identification integrator 28b, and a difference integrator 28c. During charging, the first identification integrator 28a integrates (counts) the number of seconds (predetermined cycle value: for example, 1 second) corresponding to the battery number of the storage battery 12 showing the maximum voltage value for each battery number to generate a first identification integrated value. During discharging, the first identification integrator 28a integrates (counts) the number of seconds (predetermined cycle value: for example, 1 second) corresponding to the battery number of the storage battery 12 showing the minimum voltage value for each battery number to generate a first identification integrated value. The second identification integrator 28b integrates (counts) the number of seconds (predetermined cycle value: for example, 1 second) corresponding to the battery number of the storage battery 12 showing the maximum temperature value for each battery number to generate a second identification integrated value. Furthermore, as will be described later, when the differential voltage value is used to determine the degree of deterioration of each storage battery 12 in the entire storage battery system S, the differential accumulation unit 28c accumulates (counts) the number of seconds (predetermined periodic value: for example, 1 second) corresponding to the battery number of the storage battery 12 for each battery number to generate a differential accumulation value.

[0029] The average voltage value calculation unit 30 calculates an average voltage value used when comparing the degree of deterioration of each storage battery 12 throughout the entire storage battery system S. The average voltage value calculation unit 30 calculates the average voltage value by dividing the unit voltage value of the storage battery unit 14 for each predetermined period by the number of storage batteries 12 connected in series. The use of the average voltage value will be described in detail later.

[0030] The differential voltage value calculation unit 32 calculates a differential voltage value used when comparing the degree of deterioration of each storage battery 12 throughout the entire storage battery system S. For example, the differential voltage value calculation unit 32 calculates a differential voltage value indicating the difference between the maximum battery voltage value and the average voltage value during charging, and calculates a differential voltage value indicating the difference between the minimum battery voltage value and the average voltage value during discharging. In this case, the difference is an absolute value.

[0031] The average voltage difference value calculation unit 34 calculates an average voltage difference value used when comparing the degree of deterioration of each storage battery 12 throughout the entire storage battery system S. For example, during charging, the average voltage difference value calculation unit 34 calculates an average voltage difference value by dividing a differential voltage value indicating the difference between the maximum battery voltage value and the average voltage value calculated by the differential voltage value calculation unit 32, which is an integrated differential voltage value obtained by integrating the differential voltage value for each piece of identification information generated by the differential integrator 28c, by an identification integrated value for each piece of identification information generated by the first identification integrator 28a. During discharging, the average voltage difference value is calculated by dividing a differential voltage value indicating the difference between the minimum battery voltage value and the average voltage value calculated by the differential voltage value calculation unit 32, which is an integrated differential voltage value obtained by integrating the differential voltage value for each piece of identification information generated by the differential integrator 28c, by an identification integrated value for each piece of identification information generated by the first identification integrator 28a.

[0032] When comparing the degradation levels of the storage batteries 12 across the entire battery system S, it is possible to compare the degradation levels assuming that the unit current value in the battery system S is constant. However, when the battery system S is actually operated, the unit current value may change. When the unit current value changes, the differential voltage value also changes accordingly. Therefore, when the battery system S is charged or discharged, the normalized difference calculation unit 36 ​​calculates a normalized differential voltage value by dividing the differential voltage value by the unit current value flowing during charging or discharging. The average voltage value calculation unit 30 calculates an average voltage difference value based on the calculated normalized differential voltage value, which enables more accurate determination and comparison of the degradation levels of the storage batteries 12. Details of the determination based on the normalized differential voltage value will be described later.

[0033] When the identification processing unit 28 calculates the identification integrated value by integrating the number of detections for each piece of identification information, if the storage battery system S is not charging or discharging, the influence of internal resistance does not appear in the battery voltage value and can be ignored. On the other hand, even when the unit current value is small, the influence of internal resistance appears, albeit slightly. Therefore, if the identification integrated value is calculated based on the maximum or minimum voltage value based on the change at that time, an error may occur in the deterioration determination of the storage battery 12. Therefore, the dead band processing unit 38 sets a dead band determined in advance through testing or the like for a given unit current value to suppress the occurrence of an error. For example, when a few percent (e.g., 1%) of the rated current of the storage battery 12 flows, this may cause an error in the determination, so the data is not used as the dead band. As a result, by providing the dead band, the accuracy of determining the deterioration level of the storage battery 12 can be improved.

[0034] The determination unit 22 determines that a storage battery 12 having a larger identification integrated value for each piece of identification information calculated by the identification processing unit 28 has a higher degradation level than a storage battery 12 having a smaller identification integrated value. The determination unit 22 may, for example, individually determine the degradation level based on voltage based on the first identification integrated value calculated by the first identification integrated unit 28a, or may, for example, individually determine the degradation level based on temperature of the storage battery 12 based on the second identification integrated value calculated by the second identification integrated unit 28b. The determination unit 22 also includes an adder 22a. The adder 22a may calculate a sum of the first identification integrated value related to voltage and the second identification integrated value related to temperature, and the determination unit 22 may determine the degradation level (degradation level) based on the calculated sum.

[0035] Incidentally, in the case of the storage battery system S, the degree of deterioration may vary depending on the temperature environment in which the storage battery system S is installed and the state of charge (SOC) of the storage battery units 14. Therefore, the determination unit 22 includes a correction unit 22b, and may correct the identification integrated value provided from the identification processing unit 28, for example, using the temperature value of the storage battery 12 itself. Similarly, the correction unit 22b may correct the above-mentioned average voltage difference value using the temperature value of the storage battery 12 itself. Alternatively, the average voltage difference value may be corrected using the state of charge (SOC) of the storage battery units 14. By performing such correction, it is possible to more accurately determine whether the storage battery 12 is deteriorated.

[0036] The manner in which deterioration is detected by the storage battery deterioration detection device 10 configured as above will be described in detail below. First, an example of voltage-based deterioration detection will be described with reference to Figs.

[0037] In the case of FIGS. 5 and 6, in the storage battery unit 14, two storage batteries 12 are connected in series, that is, as the storage batteries 12, (1,1) and storage battery 12 (1,2) are connected in series, and the storage battery 12 (1,2) As mentioned above, the battery 12 is more deteriorated. (1,1) indicates that the unit number of the storage battery unit 14 is "1" and the battery number of the storage battery 12 included in the storage battery unit 14 is "1". (1,2) indicates that the unit number of the storage battery unit 14 is "1" and the battery number of the storage battery 12 included in the storage battery unit 14 is "2". In addition, the internal resistance R (1,1) indicates the internal resistance of unit number 1 and battery number 1. In the case of FIG. 5, the internal resistance R of the storage battery 12 is R (1,1) <R (1,2) As described above, the more deteriorated the storage battery 12, the larger the internal resistance R. In this case, as shown in FIG. 5, the battery voltage value (closed circuit voltage value) CCV of each storage battery 12 during charging is (1,1) <CCV (1,2)Therefore, the deteriorated storage battery 12 (1,2) indicates the maximum voltage value. As a result, the voltage processing unit 24 of the calculation unit 20 performs voltage-related processing on the aggregated battery data group acquired by the acquisition unit 18, and records the battery number, which is identification information of the storage battery 12 that is deemed to be degraded. The calculation unit 20 detects the identification information (battery number) of the storage battery 12 with the maximum voltage value at a predetermined period (for example, every 1 second), and sequentially provides it to the identification processing unit 28 for integration.

[0038] FIG. 6 shows an example of the data to be recorded, and shows how the maximum voltage battery number is recorded when the unit current value I is 40 A during charging from time t1 to time t5. After time t2 when the unit current value is 40 A, the maximum voltage value is 12. (1,2) is larger, so "2" is recorded as the maximum voltage battery number. At time t1 when charging starts, no substantial charging is performed (unit current value = 0), so the effect of internal resistance R does not appear on the battery voltage value, and therefore calculation unit 20 skips the process of calculating the maximum voltage value at this time.

[0039] The identification processing unit 28 calculates an identification integrated value by integrating the number of detections for each piece of identification information (battery number). In this case, the first identification integration unit 28a integrates (counts) the number of seconds (predetermined cycle value: for example, 1 second) corresponding to the battery number of the storage battery 12 that exhibits the maximum voltage value for each battery number during charging, to generate the first identification integrated value. In the example shown in FIG. 6, (1,1) The identification integrated value is 0 seconds, and the battery is 12 (1,2) Therefore, the discrimination integrated value is 4 seconds. (1,2) The storage battery is 12 (1,1) It can be determined that the degree of deterioration is higher.

[0040] As mentioned above, the higher the temperature of the storage battery 12, the more rapidly it deteriorates. Therefore, the temperature processing unit 26 performs temperature-related processing on the aggregated battery data group acquired by the acquisition unit 18 and records the battery number, which is identification information of the storage battery 12 deemed to be degraded. The calculation unit 20 detects the identification information (battery number) of the storage battery 12 with the highest temperature value at a predetermined interval (e.g., every 1 second) and sequentially provides this information to the identification processing unit 28 for integration. In this case, the second identification accumulating unit 28b counts the number of seconds recorded in the highest temperature battery number for each battery number. Note that, as mentioned above, when performing temperature-related processing, no distinction is made between charging and discharging. Based on the identification integrated value integrated (counted) for each battery number, the determination unit 22 can determine that the larger the identification integrated value, the more degraded the storage battery 12 is.

[0041] Next, an example of detecting the deterioration level of the storage battery 12 based on both the voltage value during charging and discharging of the storage battery 12 and the temperature value of the storage battery 12 will be described with reference to FIG. 7. As described above, the first identification integrating unit 28a calculates a first identification integrated value for voltage by referring to the maximum voltage value during charging and the minimum voltage value during discharging. Similarly, as described above, the second identification integrating unit 28b calculates a second identification integrated value for temperature by referring to the maximum temperature value. Then, the summing unit 22a of the determining unit 22 calculates a first identification integrated value for each identification information (in this case, the temperature of the storage battery 12) when charging or discharging. (1,1) and storage battery 12 (1,2) ) is calculated as the sum of the first and second identification integrated values. The storage battery 12 with a larger total value is determined to be more deteriorated.

[0042] For example, in the example shown in Figure 7, if the identification information (number of seconds) recorded for each maximum voltage battery number is added up (counted) for each battery number, (1,1) becomes 0 seconds, and the battery (1,2) In addition, if the identification information (number of seconds) recorded in the highest temperature battery number is added up (counted) for each battery number, the battery (1,1) becomes 0 seconds, and the battery (1,2) The result is 5 seconds. Adding up the results for each battery number, (1,1)becomes 0 seconds, and the battery (1,2) Therefore, the determination unit 22 determines whether the battery 12 with the larger sum is the battery 12 with the larger sum. (1,2) It can be determined that the one is more deteriorated.

[0043] In the above-described example, the deterioration level of the storage battery 12 is determined by comparison within the storage battery unit 14. In the following example, the deterioration level of the storage battery 12 in the storage battery system S is determined.

[0044] Consider a case where the acquisition unit 18 acquires each battery data in the acquisition step. Then, consider a case where the calculation unit 20 calculates an identification integrated value for each storage battery unit 14 for, for example, 3600 seconds of battery data (data recording period = 1 second) in the calculation step. In this case, for example, (1) Within this, 12 storage batteries (1,1) If the voltage identification information (number of seconds) is accumulated (counted) for each battery number, it becomes 3000 seconds, and the battery 12 (1,2) Assume that the accumulated (counted) identification information (number of seconds) relating to the voltage of each battery number is 600 seconds. (1,1) > Battery 12 (1,2) On the other hand, the battery unit 14 (2) Within this, 12 storage batteries (2,1) When the voltage identification information (number of seconds) is accumulated (counted) for each battery number, it becomes 2100 seconds, and the battery 12 (2,2) Assume that the accumulated (counted) voltage identification information (number of seconds) for each battery number is 1500 seconds. (2,1) > Battery 12 (2,2) In this way, it is possible to compare the deterioration levels of the individual batteries in the storage battery unit 14. On the other hand, when comparing the deterioration levels of the individual storage batteries 12 in the entire storage battery system S, it is not always necessary to compare the deterioration levels of the individual storage batteries 12. (1,1) > Battery 12 (2,1) This does not necessarily mean that

[0045] Therefore, by comparing the storage battery units 14 based on the difference between the average voltage value and the maximum voltage value (minimum voltage value) for each storage battery unit 14, the deterioration levels of each storage battery 12 in the entire storage battery system S are compared.

[0046] First, the average voltage value calculation unit 30 calculates the average voltage (average voltage value) per storage battery 12 by dividing the unit voltage value of the storage battery unit 14 by the number of storage batteries 12 connected in series. Next, the differential voltage value calculation unit 32 calculates the differential voltage value ΔV between the maximum battery voltage value and the average voltage value during charging, using the average voltage value as a reference. Similarly, the differential voltage value calculation unit 32 calculates the differential voltage value ΔV between the minimum battery voltage value and the average voltage value during discharging, using the average voltage value as a reference. In this case, it can be determined that the storage battery 12 with a larger differential voltage value ΔV is more deteriorated. Furthermore, the differential integration unit 28c calculates a differential integration value by integrating the corresponding identification information for each identification information when calculating the differential voltage value ΔV. Note that at time t1 when charging starts, no substantial charging is performed (unit current value = 0). In other words, since the influence of the internal resistance R does not appear in the battery voltage value, the calculation unit 20 (differential integration unit 28c) skips the calculation of the maximum voltage value at this time.

[0047] Fig. 8 is an exemplary and schematic explanatory diagram showing the relationship between the maximum battery voltage value and the average voltage value in the storage battery deterioration detection device 10. Fig. 9 is an exemplary and schematic explanatory diagram showing data and calculation examples when a degraded battery is extracted based on the maximum battery voltage value and the average voltage value in the storage battery deterioration detection device 10. In this case, the differential voltage value ΔV between the maximum battery voltage value and the average voltage value calculated every second of the data recording cycle is the degradation level of the storage battery 12 recorded in the maximum voltage battery number.

[0048] The average voltage difference value calculation unit 34 calculates the average voltage difference value by dividing the difference integrated value, which is obtained by integrating the differential voltage values ​​for each piece of identification information, by the identification integrated value for each piece of identification information. The determination unit 22 then determines that the storage battery 12 with the larger average voltage difference value is more deteriorated.

[0049] FIG. 9 is an exemplary and schematic explanatory diagram showing data and calculation examples when a deteriorated battery is extracted based on a maximum battery voltage value and an average voltage value in the storage battery deterioration detection device 10. In FIG. 9, for data on the unit current value, unit voltage value, maximum voltage battery number, and maximum battery voltage value, the average voltage value can be calculated by dividing the unit voltage value by the number of series. When the number of series is 10, the unit voltage value at time t2 is 55V, so the average voltage value is calculated to be 5.5V. Since the maximum battery voltage value is 5.7V, the differential voltage value ΔV is calculated to be 0.2V. By performing the same calculation at each data recording period and calculating and accumulating (counting) the differential voltage value ΔV, the storage battery 12 (1,2) The difference integrated value is 0.8V, and the number of times (frequency) the identification information is detected is 4 (it is not counted when there is no charging or discharging). If this difference integrated value is divided by the number of times (frequency) the identification information is detected, (1,2) The average voltage difference value is calculated to be 0.2 V. By calculating the average voltage difference value for each identification information (battery number), it can be determined that the storage battery 12 with the larger average voltage difference value is more deteriorated, and this deterioration index makes it possible to compare the degree of deterioration of each storage battery 12 across the entire storage battery system S.

[0050] In the above example, the degree of deterioration of each storage battery 12 was detected assuming that the unit current value was constant. However, in an actual storage battery system S, the unit current value changes. As a result, the differential voltage value ΔV also changes in response to changes in the unit current value. Therefore, the normalized difference calculation unit 36 ​​divides the differential voltage value ΔV by the unit current value to normalize it, and then calculates the average voltage difference value. As a result, it becomes possible to more accurately determine and compare the degree of deterioration of each storage battery 12.

[0051] FIG. 10 is an exemplary schematic explanatory diagram showing data and calculation examples when a degraded battery is extracted based on a normalized average voltage difference value in the storage battery degradation detection device 10. In FIG.

[0052] In FIG. 10, the differential voltage value ΔV can be normalized by dividing it by the unit current value. At time t2, the differential voltage value ΔV is 0.2 V and the unit current value is 40 A, so the normalized differential voltage value ΔV is calculated as 0.005 V / A. By integrating (counting) this differential voltage value ΔV, the storage battery 12 (1,2) The accumulated difference value is 0.02 V / A, the number of times (frequency) the identification information was detected is 4, and the average voltage difference value is calculated to be 0.005 V / A. This normalized deterioration index makes it possible to more accurately determine and compare the degree of deterioration of each battery in the entire storage battery system S.

[0053] As mentioned above, the higher the temperature (including the temperature of the installation environment), the more the storage battery 12 tends to deteriorate. Therefore, the correction unit 22b may use the battery temperature value itself to correct the identification integrated value calculated by the identification processing unit 28. For example, for the maximum battery temperature value of each storage battery unit 14, the minimum value is set to correction coefficient 1, the maximum value is set to correction coefficient 2, and the correction is performed by multiplying the identification integrated value by a correction coefficient that is linear between the minimum and maximum values. As a result, it is possible to more accurately determine which storage batteries 12 have deteriorated.

[0054] Alternatively, the correction unit 22b may correct the average voltage difference value using the battery temperature value itself. For example, since the internal resistance R depends on temperature, the differential voltage value ΔV also changes depending on the temperature. Therefore, the differential voltage value ΔV is corrected using the highest or lowest battery temperature value for each storage battery unit 14, or the average battery temperature value which is the average of the highest or lowest battery temperature values. For example, since there is a correlation between the internal resistance R and the differential voltage value ΔV, the differential voltage value ΔV is corrected to a given temperature based on the temperature characteristics of the internal resistance R that are prepared in advance. By performing this correction, it is possible to more accurately determine whether the storage battery 12 has deteriorated.

[0055] The correction unit 22b may also correct the average voltage difference value calculated by the average voltage difference value calculation unit 34 using the state of charge (SOC) of the storage battery unit 14. In other words, because the internal resistance R of the storage battery 12 or the like depends on the SOC, the differential voltage value ΔV also changes depending on the SOC. Therefore, the differential voltage value ΔV is corrected using the SOC of the storage battery unit 14. For example, because there is a correlation between the internal resistance R and the SOC, the differential voltage value ΔV is corrected to an arbitrary SOC based on the SOC characteristics of the internal resistance R that are prepared in advance. As a result, the determination unit 22 can more accurately determine whether the storage battery 12 has deteriorated.

[0056] The battery deterioration detection program that executes processing in the battery deterioration detection device 10 of this embodiment is provided as a file in an installable or executable format, recorded on a computer-readable recording medium such as a USB memory, a semiconductor storage device such as an SSD, or a DVD (Digital Versatile Disk).

[0057] The program may also be configured to be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network, or may be configured to be provided or distributed via a network such as the Internet.

[0058] The program may also be provided in a state where it is pre-installed in a ROM or the like.

[0059] The program has a modular configuration including the above-mentioned components (acquisition unit 18, calculation unit 20, determination unit 22, etc.). When a CPU (processor) reads out the program from the storage medium and executes it, the above-mentioned components are loaded into the main storage device and generated.

[0060] (Addendum) A configuration example of the embodiment will be described below.

[0061] (Configuration example 1) an acquisition unit that acquires battery state information for each predetermined period from a storage battery system in which a plurality of storage battery units, each of which is configured by connecting a plurality of storage batteries in series, are connected in parallel, and the information can be used to estimate deterioration of the storage batteries; a calculation unit that detects, at each predetermined cycle, identification information of the storage battery that satisfies a predetermined state condition from the battery state information, and calculates an identification integrated value by integrating the number of times each of the identification information is detected; a determination unit that determines that the storage battery having a larger identification integrated value for each of the identification information has a higher degradation level than the storage battery having a smaller identification integrated value; A storage battery deterioration detection device comprising:

[0062] (Configuration example 2) When the storage battery unit is being charged, the calculation unit detects the identification information by determining that the storage battery exhibiting a maximum battery voltage value is the storage battery that satisfies the predetermined state condition, and when the storage battery unit is being discharged, the calculation unit detects the identification information by determining that the storage battery exhibiting a minimum battery voltage value is the storage battery that satisfies the predetermined state condition, and calculates the identification integrated value for each of the identification information. 10 is a diagram showing a battery deterioration detection device according to configuration example 1.

[0063] (Configuration example 3) the calculation unit detects the identification information of the storage battery that exhibits the highest battery temperature value in the storage battery unit, determining that the storage battery satisfies the predetermined state condition, and calculates the identification integrated value for each of the identification information. 10 is a diagram showing a battery deterioration detection device according to configuration example 1.

[0064] (Configuration example 4) the calculation unit, when the storage battery unit is being charged, detects the identification information of the storage battery that exhibits the maximum battery voltage value as the storage battery that satisfies the predetermined state condition, and when the storage battery unit is being discharged, detects the identification information of the storage battery that exhibits the minimum battery voltage value as the storage battery that satisfies the predetermined state condition, and calculates the identification integrated value detected based on the voltage value as a first identification integrated value; and, in the storage battery unit, detects the identification information of the storage battery that exhibits the highest temperature value as the storage battery that satisfies the predetermined state condition, and calculates the identification integrated value detected based on the temperature value as a second identification integrated value; the determining unit determines the deterioration level based on a sum of the first identification integrated value and the second identification integrated value for each of the pieces of identification information when the battery is charged or discharged. 10 is a diagram showing a battery deterioration detection device according to configuration example 1.

[0065] (Configuration Example 5) the calculation unit calculates an average voltage value by dividing the voltage value of the storage battery unit for each predetermined period by the number of series-connected storage batteries; when the storage battery unit is being charged, the calculation unit detects the identification information of the storage battery that exhibits a maximum battery voltage value for each predetermined period as the storage battery that satisfies the predetermined state condition, and calculates a differential voltage value that indicates the difference between the maximum battery voltage value and the average voltage value; when the storage battery unit is being discharged, the calculation unit detects the identification information of the storage battery that exhibits a minimum battery voltage value for each predetermined period as the storage battery that satisfies the predetermined state condition, and calculates a differential voltage value that indicates the difference between the minimum battery voltage value and the average voltage value; when the storage battery unit is being charged or discharged, the calculation unit calculates an average voltage difference value by dividing a differential integrated value obtained by integrating the differential voltage values ​​for each identification information by the identification integrated value for each identification information; the determination unit determines, when the charging or discharging is performed, that the storage battery having a larger average voltage difference value for each piece of identification information has a higher degradation level than the storage battery having a smaller average voltage difference value. 10 is a diagram showing a battery deterioration detection device according to configuration example 1.

[0066] (Configuration Example 6) the calculation unit, when the storage battery unit is being charged, calculates a normalized differential voltage value by dividing the differential voltage value indicating the difference between the maximum battery voltage value and the average voltage value by a current value (unit current value) that flows during charging; when the storage battery unit is being discharged, calculates a normalized differential voltage value by dividing the differential voltage value indicating the difference between the minimum battery voltage value and the average voltage value by a current value (unit current value) that flows during discharging; and calculates the average voltage difference value when the storage battery unit is being charged or when the storage battery unit is being discharged based on the normalized differential voltage value. 10. The storage battery deterioration detection device according to configuration example 5.

[0067] (Configuration Example 7) the determination unit corrects the identification integrated value based on a temperature value of the storage battery unit. The storage battery deterioration detection device according to any one of configuration examples 2 to 4.

[0068] (Configuration Example 8) the determination unit corrects the average voltage difference value based on a temperature value of the storage battery unit. The storage battery deterioration detection device according to configuration example 5 or 6.

[0069] (Configuration Example 9) the determination unit corrects the average voltage difference value based on the charging rate of the storage battery unit. 10. The storage battery deterioration detection device according to configuration example 5.

[0070] (Configuration Example 10) the calculation unit does not add the identification information of the storage battery to the identification integrated value even if the state condition is satisfied when the value of the current flowing through the storage battery unit is less than a predetermined value; 10 is a diagram showing a battery deterioration detection device according to configuration example 1.

[0071] (Configuration Example 11) an acquisition step in which an acquisition unit acquires battery state information for each predetermined period from a storage battery system in which a plurality of storage battery units, each configured by a plurality of storage batteries connected in series, are connected in parallel, the battery state information being usable for estimating deterioration of the storage batteries; a calculation step in which a calculation unit detects identification information of the storage battery that satisfies a predetermined state condition from the battery state information at each predetermined period, and calculates an identification integrated value by integrating the number of times each of the identification information is detected; a determining step in which a determining unit determines that the storage battery having a larger identification integrated value for each of the identification information has a higher degradation level than the storage battery having a smaller identification integrated value; A method for detecting deterioration of a storage battery, comprising:

[0072] (Configuration Example 12) Computer, an acquisition unit that acquires battery state information for each predetermined period from a storage battery system in which a plurality of storage battery units, each of which is configured by connecting a plurality of storage batteries in series, are connected in parallel, and the information can be used to estimate deterioration of the storage batteries; a calculation unit that detects, at each predetermined cycle, identification information of the storage battery that satisfies a predetermined state condition from the battery state information, and calculates an identification integrated value by integrating the number of times each of the identification information is detected; a determination unit that determines that the storage battery having a larger identification integrated value for each of the identification information has a higher degradation level than the storage battery having a smaller identification integrated value; To function as, Battery deterioration detection program.

[0073] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0074] 10...storage battery deterioration detection device, 12...storage battery, 14...storage battery unit, 16...BMU, 18...acquisition unit, 20...calculation unit, 22...determination unit, 24...voltage processing unit, 26...temperature processing unit, 28...identification processing unit, 28a...first identification integrator, 28b...second identification integrator, 28c...difference integrator, 30...average voltage value calculation unit, 32...differential voltage value calculation unit, 34...average voltage difference value calculation unit, 36...normalized difference calculation unit, 38...dead band processing unit, S...storage battery system.

Claims

1. an acquisition unit that acquires battery state information for each predetermined period from a storage battery system in which a plurality of storage battery units, each of which is configured by connecting a plurality of storage batteries in series, are connected in parallel, and the information can be used to estimate deterioration of the storage batteries; a calculation unit that detects, at each predetermined cycle, identification information of the storage battery that satisfies a predetermined state condition from the battery state information, and calculates an identification integrated value by integrating the number of times each of the identification information is detected; a determination unit that determines that the storage battery having a larger identification integrated value for each of the identification information has a higher degradation level than the storage battery having a smaller identification integrated value; A storage battery deterioration detection device comprising:

2. When the storage battery unit is being charged, the calculation unit detects the identification information by determining that the storage battery exhibiting a maximum battery voltage value is the storage battery that satisfies the predetermined state condition, and when the storage battery unit is being discharged, the calculation unit detects the identification information by determining that the storage battery exhibiting a minimum battery voltage value is the storage battery that satisfies the predetermined state condition, and calculates the identification integrated value for each of the identification information. The storage battery deterioration detection device according to claim 1 .

3. the calculation unit detects the identification information of the storage battery that exhibits the highest battery temperature value in the storage battery unit, determining that the storage battery satisfies the predetermined state condition, and calculates the identification integrated value for each of the identification information. The storage battery deterioration detection device according to claim 1 .

4. When the storage battery unit is being charged, the calculation unit detects the identification information of the storage battery that exhibits the maximum battery voltage value as the storage battery that satisfies the predetermined state condition, and when the storage battery unit is being discharged, the calculation unit detects the identification information of the storage battery that exhibits the minimum battery voltage value as the storage battery that satisfies the predetermined state condition, and calculates the identification integrated value detected based on the voltage value as a first identification integrated value, and when the storage battery unit is being discharged, the calculation unit detects the identification information of the storage battery that exhibits the highest temperature value as the storage battery that satisfies the predetermined state condition, and calculates the identification integrated value detected based on the temperature value as a second identification integrated value, the determining unit determines the deterioration level based on a sum of the first identification integrated value and the second identification integrated value for each of the pieces of identification information when the battery is charged or discharged. The storage battery deterioration detection device according to claim 1 .

5. the calculation unit calculates an average voltage value by dividing the voltage value of the storage battery unit for each predetermined period by the number of series-connected storage batteries; when the storage battery unit is being charged, the calculation unit detects the identification information of the storage battery that exhibits a maximum battery voltage value for each predetermined period as the storage battery that satisfies the predetermined state condition, and calculates a differential voltage value that indicates the difference between the maximum battery voltage value and the average voltage value; when the storage battery unit is being discharged, the calculation unit detects the identification information of the storage battery that exhibits a minimum battery voltage value for each predetermined period as the storage battery that satisfies the predetermined state condition, and calculates a differential voltage value that indicates the difference between the minimum battery voltage value and the average voltage value; when the storage battery unit is being charged or discharged, the calculation unit calculates an average voltage difference value by dividing a differential integrated value obtained by integrating the differential voltage values ​​for each identification information by the identification integrated value for each identification information; the determination unit determines, when the charging or discharging is performed, that the storage battery having a larger average voltage difference value for each piece of identification information has a higher degradation level than the storage battery having a smaller average voltage difference value. The storage battery deterioration detection device according to claim 1 .

6. the calculation unit calculates a normalized differential voltage value by dividing the differential voltage value indicating the difference between the maximum battery voltage value and the average voltage value by the value of a current flowing during charging when the storage battery unit is being charged, and calculates a normalized differential voltage value by dividing the differential voltage value indicating the difference between the minimum battery voltage value and the average voltage value by the value of a current flowing during discharging when the storage battery unit is being discharged, and calculates the average voltage difference value when the storage battery unit is being charged or when the storage battery unit is being discharged based on the normalized differential voltage value. The storage battery deterioration detection device according to claim 5.

7. the determination unit corrects the identification integrated value based on a temperature value of the storage battery unit. The storage battery deterioration detection device according to any one of claims 2 to 4.

8. the determination unit corrects the average voltage difference value based on a temperature value of the storage battery unit. The storage battery deterioration detection device according to claim 5 or 6.

9. the determination unit corrects the average voltage difference value based on the charging rate of the storage battery unit. The storage battery deterioration detection device according to claim 5.

10. the calculation unit does not add the identification information of the storage battery to the identification integrated value even if the state condition is satisfied when the value of the current flowing through the storage battery unit is less than a predetermined value; The storage battery deterioration detection device according to claim 1 .

11. an acquisition step in which an acquisition unit acquires battery state information for each predetermined period from a storage battery system in which a plurality of storage battery units, each configured by a plurality of storage batteries connected in series, are connected in parallel, the battery state information being usable for estimating deterioration of the storage batteries; a calculation step in which a calculation unit detects identification information of the storage battery that satisfies a predetermined state condition from the battery state information at each predetermined period, and calculates an identification integrated value by integrating the number of times each of the identification information is detected; a determining step in which a determining unit determines that the storage battery having a larger identification integrated value for each of the identification information has a higher degradation level than the storage battery having a smaller identification integrated value; A method for detecting deterioration of a storage battery, comprising:

12. Computer, an acquisition unit that acquires battery state information for each predetermined period from a storage battery system in which a plurality of storage battery units, each of which is configured by connecting a plurality of storage batteries in series, are connected in parallel, and the information can be used to estimate deterioration of the storage batteries; a calculation unit that detects, at each predetermined cycle, identification information of the storage battery that satisfies a predetermined state condition from the battery state information, and calculates an identification integrated value by integrating the number of times each of the identification information is detected; a determination unit that determines that the storage battery having a larger identification integrated value for each of the identification information has a higher degradation level than the storage battery having a smaller identification integrated value; To function as, Battery deterioration detection program.

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