Deterioration diagnostic device, deterioration diagnostic method, and program

Abstract

This technology provides the ability to diagnose the degradation of a battery system in which numerous modules are connected in series and parallel. [Solution] The degradation diagnosis device (1) includes a degradation degree calculation unit (14) that calculates the degree of degradation of each of the multiple battery modules (31-1 to 31-m) based on the internal resistance of each of the multiple battery modules (31-1 to 31-m), and a degradation diagnosis unit (15) that diagnoses the degradation of the battery bank (21-1 to 21-n) based on the degree of degradation of the battery module that is the most degraded among the multiple battery modules (31-1 to 31-m).

Description

Technical Field

[0006] , , ,

[0001] The present disclosure relates to a degradation diagnosis device, a degradation diagnosis method, and a program.

Background Art

[0002] Techniques have been proposed for analyzing the current-voltage characteristics during charge and discharge of a storage battery to calculate the internal resistance of the storage battery and determine the degradation state of the storage battery. According to such techniques, it is not necessary to temporarily stop the operation of the storage battery for degradation diagnosis, and the degradation state can be determined while continuing the operation of the power storage system.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of a storage battery system in which a large number of modules are connected in series and parallel, it is difficult to obtain the voltage values of all the battery cells included in the modules. Therefore, there is a need for a method of diagnosing the degradation of the storage battery system without obtaining the voltage values of all the battery cells.

[0005] In addition, a method for diagnosing the degradation of a storage battery system in which a large number of modules are connected in series and parallel is not disclosed in the above-mentioned patent documents. One aspect of the present disclosure aims to provide a technique capable of diagnosing the degradation of a storage battery system in which a large number of modules are connected in series and parallel.

Means for Solving the Problems

[0006] To solve the above problems, a degradation diagnostic device according to one aspect of the present disclosure is a degradation diagnostic device for diagnosing the degradation of a battery bank in which multiple modules, each having multiple battery cells connected in series, are connected in series and parallel, and comprises at least: an acquisition unit that acquires information on the voltage value and current value of each of the multiple modules included in the battery bank; an internal resistance calculation unit that calculates the internal resistance of each of the multiple modules based on the information on the voltage value and the current value; a degradation degree calculation unit that calculates the degree of degradation of each of the multiple modules based on the internal resistance of the multiple modules; and a degradation diagnostic unit that diagnoses the degradation of the battery bank based on the degree of degradation of the module that is most degraded among the multiple modules.

[0007] To solve the above problems, a degradation diagnosis method according to one aspect of the present disclosure is a degradation diagnosis method for diagnosing the degradation of a battery bank in which multiple modules, each having multiple battery cells connected in series, are connected in series and parallel, and includes at least the steps of: acquiring information on the voltage value and current value of each of the multiple modules included in the battery bank; calculating the internal resistance of each of the multiple modules based on the information on the voltage value and the current value; calculating the degree of degradation of each of the multiple modules based on the internal resistance of each of the multiple modules; and diagnosing the degradation of the battery bank based on the degree of degradation of the module that is most degraded among the multiple modules.

[0008] To solve the above problems, a program according to one aspect of the present disclosure is a program that performs a degradation diagnosis method for diagnosing the degradation of a battery bank in which multiple modules, each having multiple battery cells connected in series, are connected in series and parallel, and causes a computer to perform at least the following processes: acquiring information on the voltage value and current value of each of the multiple modules included in the battery bank; calculating the internal resistance of each of the multiple modules based on the information on the voltage value and the current value; calculating the degree of degradation of each of the multiple modules based on the internal resistance of the multiple modules; and diagnosing the degradation of the battery bank based on the degree of degradation of the module that is most degraded among the multiple modules. [Effects of the Invention]

[0009] According to one aspect of this disclosure, it is possible to diagnose the degradation of a battery system in which a large number of modules are connected in series and parallel. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an example configuration of a deterioration diagnostic device according to one embodiment of the present disclosure. [Figure 2] This diagram shows an example configuration of a battery storage module. [Figure 3] This is a flowchart illustrating the processing procedure of a deterioration diagnostic device according to one embodiment of the present disclosure. [Figure 4] This figure shows an example of a deterioration diagnosis result. [Figure 5] This figure shows another example of a deterioration diagnosis result. [Modes for carrying out the invention]

[0011] [Embodiment 1] Hereinafter, embodiments relating to one aspect of this disclosure (hereinafter also referred to as "this embodiment") will be described based on the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0012] (Configuration of the deterioration diagnosis system 100) Figure 1 is a block diagram showing the configuration of the main parts of the degradation diagnosis system 100 according to this embodiment. The degradation diagnosis system 100 comprises a degradation diagnosis device 1, a battery storage device 2, and a battery management system (BMS) 3.

[0013] The battery storage device 2 comprises multiple battery banks 21-1 to 21-n. Each of the battery banks 21-1 to 21-n comprises multiple battery modules 31-1 to 31-m. Hereinafter, m and n are integers of 2 or greater. The battery modules are sometimes simply referred to as modules. Furthermore, the battery banks 21-1 to 21-n are sometimes collectively referred to as battery bank 21, and the battery modules 31-1 to 31-m are sometimes collectively referred to as battery module 31.

[0014] In battery bank 21-1, multiple battery modules 31-1 to 31-m are connected in series and parallel. Connecting in series and parallel includes connecting multiple battery modules in parallel, connecting multiple sets of parallel-connected battery modules in series, and connecting them in combination. Furthermore, connecting in series and parallel also includes connecting multiple battery modules only in series, and connecting multiple battery modules only in parallel.

[0015] Figure 2 shows an example of the configuration of a battery module. The battery module 31 contains one or more battery cells 201 inside, and generally multiple battery cells 201 are connected in series. Inside the battery module 31, there is a temperature sensor (not shown) for the BMS 3 to monitor the temperature of the battery cells 201. The temperature sensor may be located in one place or in multiple places within the battery module 31.

[0016] In addition, the battery module 31 is provided with an ammeter 202 for measuring the current flowing through the battery cell 201 and a voltmeter 203 for measuring the voltage of the battery cell 201. The arrangement of the ammeter 202 and the voltmeter 203 inside the battery module 31 varies depending on the product specifications of the battery module 31.

[0017] In the battery module 31, when all the battery cells 201 are connected in series, it is common for one ammeter 202 to be installed in the series circuit. Or, when the battery cells 201 are connected in series and parallel in the battery module 31, it is common for the ammeter 202 to be installed in each series circuit.

[0018] Regarding the voltmeter 203, it is common for the voltage of each battery cell 201 to be monitored. Also, the voltmeter 203 may be provided to measure the combined voltage of several serially connected battery cells 201. Furthermore, the voltmeter 203 may be provided to measure the voltage of the entire battery module 31, that is, the terminal voltage of the battery module 31.

[0019] The BMS 3 acquires information such as the terminal voltage of the battery module 31, the voltage of each battery cell 201 in the battery module 31, the current of the battery module 31, and the internal temperature of the battery module 31 from the battery module 31. In addition, it monitors whether an abnormality has occurred in the battery module 31 and calculates the state of charge (SOC) of the battery module 31. The BMS 3 is an information processing system that executes processing according to the configuration and characteristics of the battery module 31. In FIG. 1, the BMS 3 is configured to acquire all the data of the battery modules 31-1 to 31-m in the battery banks 21-1 to 21-n. However, the BMS 3 may be provided for each of the battery banks 21-1 to 21-n, or may have other configurations.

[0020] BMS3 extracts the maximum and minimum voltages of the battery cells 201 in the battery module 31 by referring to the voltages of each battery cell 201 in the battery module 31 acquired from the battery module 31. Then, BMS3 notifies the deterioration diagnosis device 1 of the terminal voltage of the battery module 31, the maximum voltage of the battery cells 201 in the battery module 31, the minimum voltage of the battery cells 201 in the battery module 31, the current flowing through the battery module 31 (battery cells 201), and the internal temperature of the battery module 31.

[0021] Thus, instead of directly notifying the deterioration diagnosis device 1 of the voltages of each battery cell 201 in the battery module 31, BMS3 can reduce the amount of information notified to the deterioration diagnosis device 1 by notifying only the terminal voltage of the battery module 31, the maximum voltage of the battery cells 201 in the battery module 31, and the minimum voltage of the battery cells 201 in the battery module 31.

[0022] Note that BMS3 can output voltage waveform data based on the terminal voltage of the battery module 31, the maximum voltage of the battery cells 201 in the battery module 31, and the minimum voltage of the battery cells 201 in the battery module 31 to the deterioration diagnosis device 1. Similarly, BMS3 can output current waveform data based on the current value of the battery module 31 to the deterioration diagnosis device 1.

[0023] (Configuration of the deterioration diagnosis device 1) The deterioration diagnosis device 1 includes an acquisition unit 11, a correction processing unit 12, an internal resistance calculation unit 13, a deterioration degree calculation unit 14, a deterioration diagnosis unit 15, and a storage unit 16. The acquisition unit 11 acquires current waveform data, voltage waveform data, and internal temperature regarding the battery module 31 from BMS3.

[0024] The correction processing unit 12 executes correction processing such as correction of the time-axis shift between the current waveform data and the voltage waveform data, creation of intermediate data by linear correction or curve correction, etc. based on the current waveform data and the voltage waveform data acquired by the acquisition unit 11. The current waveform data and the voltage waveform data corrected by the correction processing unit 12 are sequentially stored in the storage unit 16.

[0025] The internal resistance calculation unit 13 calculates the internal resistance of the battery module 31 or battery cell 201 based on the current waveform data and voltage waveform data that have been corrected by the correction processing unit 12. The internal resistance calculation unit 13 calculates the circuit parameters of the equivalent electrical circuit so that the equivalent electrical circuit simulating the battery module 31 or battery cell 201 has current-voltage characteristics. The internal resistance of the battery module 31 or battery cell 201 is one of the circuit parameters of the equivalent electrical circuit, and in this way the internal resistance calculation unit 13 calculates the internal resistance of the battery module 31 or battery cell 201.

[0026] More specifically, the internal resistance calculation unit 13 reads the corrected current waveform data stored in the memory unit 16 and extracts sections in which the current began to flow at or above a predetermined threshold (e.g., 0.2C) within a certain period of time from the pause section. The extraction is completed when a certain period of time has elapsed since the current began to flow and the charge / discharge rate has not fluctuated significantly. The extraction range includes several points in the pause section and extends to the extraction completion point. The data extracted by the internal resistance calculation unit 13 consists of the following three types of data within the extraction range. Note that 1.0C is the current value that can be supplied to the entire capacity of the battery device 2 over one hour, and by setting the threshold to 0.2C, sections in which a current of 1 / 5 or more of the total capacity flowed can be extracted.

[0027] (1) Voltage waveform of the terminal voltage of the battery module 31, current waveform of the battery module 31, internal temperature of the battery module 31 (2) Voltage waveform of the highest voltage battery cell 201 in the battery module 31, current waveform of the battery module 31, internal temperature of the battery module 31 (3) Voltage waveform of the lowest voltage battery cell 201 in the battery module 31, current waveform of the battery module 31, and internal temperature of the battery module 31.

[0028] In the initial stages of installing the battery storage device 2, the internal resistance calculation unit 13 compares the calculated value with a preset true value. After a certain period, it reads and compares the results of the past few stored in the memory unit 16. If the deviation is significantly greater than a preset deviation threshold (ratio), for example 40% (based on the true value), the data is discarded.

[0029] The internal resistance calculation unit 13 basically calculates the internal resistance of the battery module 31 by analyzing the data in (1) above. However, if the internal resistance obtained by analyzing the data in (2) or (3) above is consistently greater than the internal resistance obtained by analyzing the data in (1) above, the internal resistance obtained by analyzing that data is adopted.

[0030] Furthermore, since the internal resistance also fluctuates depending on the internal temperature of the battery module 31, the internal resistance calculation unit 13 corrects the internal resistance by referring to the internal temperature of the battery module 31.

[0031] The degradation degree calculation unit 14 calculates the degradation degree of the battery module 31 based on the internal resistance calculated by the internal resistance calculation unit 13. If the initial internal resistance of the battery module 31 is C0 and the current internal resistance of the battery module 31 is C1, the degradation degree is given by the following equation (Equation 1). Note that k is a predetermined coefficient.

[0032] Deterioration degree=k×C0 / C1×100(%) (Formula 1) The degradation diagnosis unit 15 diagnoses the degradation of the battery storage device 2 based on the degradation level of each battery module 31-1 to 31-m (battery cell 201) inside the battery banks 21-1 to 21-n. Basically, the degradation diagnosis unit 15 diagnoses the degradation of the battery storage device 2 by comparing the degradation level of the battery module 31 that is the most degraded (has the lowest degradation level) among the battery modules 31-1 to 31-m included in the battery bank 21 with a predetermined threshold.

[0033] For example, the degradation diagnosis unit 15 diagnoses that the battery system 2 is not degraded if the degradation level of the most degraded battery module 31 inside battery banks 21-1 to 21-n is above a threshold. Conversely, the degradation diagnosis unit 15 diagnoses that the battery system 2 is degraded if the degradation level of the most degraded battery module 31 inside battery banks 21-1 to 21-n is below a threshold. A battery bank 21 or battery module 31 determined to be degraded is deemed to require replacement.

[0034] Alternatively, the degradation diagnosis unit 15 may extract the degradation level of the battery module 31 that is most degraded among the battery modules 31-1 to 31-m in each of the battery banks 21-1 to 21-n, and diagnose the degradation of battery banks 21-1 to 21-n based on the difference between the maximum and minimum values ​​of the extracted degradation level.

[0035] For example, the degradation diagnosis unit 15 diagnoses that the battery storage device 2 is not degraded if the difference between the maximum and minimum values ​​of the extracted degradation level is less than a threshold. Conversely, the degradation diagnosis unit 15 diagnoses that the battery storage device 2 is degraded (imbalance) if the difference between the maximum and minimum values ​​of the extracted degradation level is greater than or equal to a threshold.

[0036] If an imbalance is detected, the deterioration of the other battery banks 21 will be accelerated by the most deteriorated battery bank 21, so at least the most deteriorated battery bank 21 needs to be replaced.

[0037] Figure 3 is a flowchart illustrating the processing procedure of a degradation diagnosis device according to one embodiment of the present disclosure. First, the acquisition unit 11 acquires information from the BMS3 regarding the voltage values ​​of each of the multiple storage battery modules 31-1 to 31-m included in the battery banks 21-1 to 21-n, the current values ​​of the storage battery modules 31-1 to 31-m, and the internal temperature of the storage battery modules 31-1 to 31-m, and stores them in the storage unit 16 (S11).

[0038] The information regarding the voltage values ​​of each battery module 31-1 to 31-m includes the terminal voltage of battery modules 31-1 to 31-m, the voltage of the highest voltage battery cell 201 within battery modules 31-1 to 31-m, and the voltage of the lowest voltage battery cell 201 within battery modules 31-1 to 31-m.

[0039] When data capable of performing degradation diagnosis is accumulated in the storage unit 16, the correction processing unit 12 performs correction processing based on the current waveform data and voltage waveform data, such as correcting the time axis shift between the current waveform data and the voltage waveform data, and creating intermediate data by linear correction or curve correction (S12). The current waveform data and voltage waveform data corrected by the correction processing unit 12 are sequentially stored in the storage unit 16.

[0040] Next, the internal resistance calculation unit 13 calculates the internal resistance of the battery modules 31-1 to 31-m or the battery cell 201 based on the current waveform data and voltage waveform data that have been corrected by the correction processing unit 12 (S13). As described above, the internal resistance calculation unit 13 calculates and corrects the internal resistance using the three types of data described in (1) to (3) above.

[0041] Next, the degradation degree calculation unit 14 uses the above (Equation 1) to calculate the degradation degree of the battery modules 31-1 to 31-m (battery cells 201) from the internal resistance of the battery modules 31-1 to 31-m (battery cells 201) calculated by the internal resistance calculation unit 13, and stores it in the storage unit 16 (S14).

[0042] Finally, the degradation diagnosis unit 15 diagnoses the degradation of the battery storage device 2 based on the degree of degradation of each battery module 31-1 to 31-m (battery cell 201) inside the battery banks 21-1 to 21-n (S15).

[0043] The degradation diagnosis unit 15 diagnoses the degradation of the battery device 2 by comparing the degradation level of the battery module 31 that is the most degraded (least degraded) among the battery modules 31-1 to 31-m included in the battery banks 21-1 to 21-n with a predetermined threshold.

[0044] Furthermore, the degradation diagnosis unit 15 extracts the degradation level of the battery module 31 that is most degraded among the battery modules 31-1 to 31-m in each of the battery banks 21-1 to 21-n, and diagnoses the degradation of battery banks 21-1 to 21-n based on the difference between the maximum and minimum values ​​of the extracted degradation level.

[0045] Figure 4 shows an example of a degradation diagnosis result, illustrating a case where the battery storage device 2 is equipped with four battery banks (battery bank 1 to battery bank 4), and each of battery banks 1 to 4 is equipped with 10 modules (module 1 to module 10).

[0046] As shown in Figure 4, among the modules in battery bank 1, module 3 has the lowest degradation level of "75" (meaning it is the most degraded), so the degradation level of battery bank 1 is set to "75". Similarly, the degradation levels of battery bank 2, battery bank 3, and battery bank 4 are all set to "75".

[0047] The degradation diagnosis unit 15 compares the degradation level of each battery bank 1 to 4 with a predetermined threshold, and if any battery bank has a degradation level below the threshold, it diagnoses that the battery storage device 2 is degraded. The degradation level of the battery storage device 2 is set to the lowest value among battery banks 1 to 4, which is "75".

[0048] Furthermore, since the difference between the maximum and minimum degradation levels of battery banks 1 to 4 is "0" and is smaller than a predetermined threshold (for example, 3%), the degradation diagnosis unit 15 determines that there is "no" balance abnormality in the battery storage device 2.

[0049] Figure 5 shows another example of degradation diagnosis results. As shown in Figure 5, among the modules of battery bank 1, modules 1, 2, and 10 have the lowest degradation level of "81" (meaning they are the most degraded), so the degradation level of battery bank 1 is set to "81". Similarly, the degradation level of battery bank 2 is set to "76", the degradation level of battery bank 3 is set to "78", and the degradation level of battery bank 4 is set to "77".

[0050] The degradation diagnosis unit 15 compares the degradation level of each battery bank 1 to 4 with a predetermined threshold, and if any battery bank has a degradation level below the threshold, it diagnoses that the battery storage device 2 is degraded. The degradation level of the battery storage device 2 is set to the lowest value among battery banks 1 to 4, which is "76".

[0051] Furthermore, the difference between the maximum and minimum degradation levels of battery banks 1 to 4 is "5," which is greater than a predetermined threshold (for example, 3%). Therefore, the degradation diagnosis unit 15 determines that an imbalance has occurred in the battery storage device 2.

[0052] Because the battery balance has been diagnosed as an imbalance, the most degraded battery bank 2 is pulling the other battery banks along with it, accelerating their deterioration. Therefore, at the very least, battery bank 2, which is the most degraded, needs to be replaced.

[0053] (Effects of deterioration diagnostic device 1) As described above, according to the degradation diagnosis device 1 of this embodiment, the degradation diagnosis unit 15 diagnoses the degradation of battery banks 21-1 to 21-n based on the degree of degradation of the module that is most degraded among the multiple battery modules 31-1 to 31-m inside the battery banks 21-1 to 21-n. Therefore, the degradation diagnosis device 1 makes it possible to easily diagnose the degradation of battery banks 21-1 to 21-n equipped with multiple battery modules 31-1 to 31-m.

[0054] Furthermore, the degradation diagnosis unit 15 extracts the degradation level of the most degraded module among the multiple battery modules 31-1 to 31-m in each of the multiple battery banks 21-1 to 21-n, and diagnoses the degradation of the multiple battery banks 21-1 to 21-n based on the difference between the maximum and minimum values ​​of the extracted degradation level. Therefore, by replacing the most degraded battery bank 21, it is possible to prevent the degradation of the other battery banks 21 from being accelerated by being pulled down by the most degraded battery bank 21.

[0055] Furthermore, the acquisition unit 11 acquires the terminal voltages of the battery modules 31-1 to 31-m as information regarding the voltage values ​​of the battery banks 21-1 to 21-n. Therefore, the amount of information notified from the BMS 3 to the degradation diagnosis device 1 can be reduced.

[0056] Furthermore, the acquisition unit 11 acquires the highest voltage value of the battery cell 201 in the battery module 31-1 to 31-m as information regarding the voltage values ​​of the battery banks 21-1 to 21-n. Therefore, the amount of information that the BMS 3 notifies the degradation diagnosis device 1 can be reduced.

[0057] Furthermore, the acquisition unit 11 acquires the lowest voltage value of the battery cells 201 in the battery modules 31-1 to 31-m as information regarding the voltage values ​​of the battery banks 21-1 to 21-n. Therefore, the amount of information notified from the BMS 3 to the degradation diagnosis device 1 can be reduced.

[0058] Furthermore, the acquisition unit 11 acquires the internal temperature of each of the multiple battery modules 31-1 to 31-m, and the internal resistance calculation unit 13 corrects the internal resistance of each of the multiple battery modules 31-1 to 31-m based on the internal temperature. Therefore, the internal resistance calculation unit 13 can calculate a more accurate internal resistance.

[0059] [Examples of implementation using software] The control block of the degradation diagnosis device 1 may be implemented by logic circuits (hardware) formed on an integrated circuit (IC chip) or the like, or by software.

[0060] In the latter case, the degradation diagnostic device 1 includes a computer that executes instructions for a program, which is software that implements each function. This computer includes, for example, one or more processors and a computer-readable recording medium that stores the program. The object of this disclosure is achieved when the processor reads the program from the recording medium and executes it in the computer. For example, a CPU (Central Processing Unit) can be used as the processor. As the recording medium, a "tangible medium that is not temporary," such as ROM (Read Only Memory), can be used, as well as tape, disk, card, semiconductor memory, programmable logic circuit, etc. It may also further include RAM (Random Access Memory) for deploying the program. Furthermore, the program may be supplied to the computer via any transmission medium capable of transmitting the program (such as a communication network or broadcast wave). One aspect of this disclosure can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[0061] 〔summary〕 A degradation diagnostic device according to Embodiment 1 of the present disclosure is a degradation diagnostic device for diagnosing the degradation of a battery bank in which a plurality of modules, each having a plurality of battery cells connected in series, are connected in series and parallel, and comprises at least: an acquisition unit that acquires information on the voltage value and current value of each of the plurality of modules included in the battery bank; an internal resistance calculation unit that calculates the internal resistance of each of the plurality of modules based on the information on the voltage value and the current value; a degradation degree calculation unit that calculates the degree of degradation of each of the plurality of modules based on the internal resistance of each of the plurality of modules; and a degradation diagnostic unit that diagnoses the degradation of the battery bank based on the degree of degradation of the module that is most degraded among the plurality of modules.

[0062] In the degradation diagnosis device according to Embodiment 2 of the present disclosure, in Embodiment 1, the degradation diagnosis unit extracts the degree of degradation of the module that is most degraded among the modules in each of the plurality of battery banks, and diagnoses the degradation of the plurality of battery banks based on the difference between the maximum and minimum values ​​of the extracted degree of degradation.

[0063] In the degradation diagnostic device according to embodiment 3 of this disclosure, in embodiment 1 or 2 above, the acquisition unit acquires the terminal voltage of the module as information relating to the voltage value.

[0064] In the degradation diagnostic device according to aspect 4 of this disclosure, in aspects 1 to 3 above, the acquisition unit acquires the highest voltage value of the battery cell in the module as information relating to the voltage value.

[0065] In the degradation diagnostic device according to aspect 5 of this disclosure, in aspects 1 to 4 above, the acquisition unit acquires the lowest voltage value of the battery cell in the module as information relating to the voltage value.

[0066] In the degradation diagnostic device according to embodiment 6 of the present disclosure, in embodiments 1 to 5 above, the acquisition unit acquires the internal temperature of each of the plurality of modules, and the internal resistance calculation unit corrects the internal resistance of each of the plurality of modules based on the internal temperature.

[0067] A degradation diagnosis method according to aspect 7 of the present disclosure is a degradation diagnosis method for diagnosing the degradation of a battery bank in which multiple modules, each having multiple battery cells connected in series, are connected in series and parallel, and includes at least the steps of: acquiring information on the voltage value and current value of each of the multiple modules included in the battery bank; calculating the internal resistance of each of the multiple modules based on the information on the voltage value and the current value; calculating the degree of degradation of each of the multiple modules based on the internal resistance of each of the multiple modules; and diagnosing the degradation of the battery bank based on the degree of degradation of the module that is most degraded among the multiple modules.

[0068] The degradation diagnosis method according to aspect 8 of the present disclosure, in the step of diagnosing the degradation in aspect 7, extracts the degree of degradation of the module that is most degraded among the modules in each of the plurality of battery banks, and diagnoses the degradation of the plurality of battery banks based on the difference between the maximum and minimum values ​​of the extracted degree of degradation.

[0069] A program according to aspect 9 of the present disclosure is a program that performs a degradation diagnosis method for diagnosing the degradation of a battery bank in which multiple modules, each having multiple battery cells connected in series, are connected in series and parallel, and causes a computer to perform at least the following processes: acquiring information on the voltage value and current value of each of the multiple modules included in the battery bank; calculating the internal resistance of each of the multiple modules based on the information on the voltage value and the current value; calculating the degree of degradation of each of the multiple modules based on the internal resistance of the multiple modules; and diagnosing the degradation of the battery bank based on the degree of degradation of the module that is most degraded among the multiple modules.

[0070] The program according to aspect 10 of the present disclosure, in the process of diagnosing the degradation in aspect 9, extracts the degree of degradation of the module that is most degraded among the modules in each of the plurality of battery banks, and diagnoses the degradation of the plurality of battery banks based on the difference between the maximum and minimum values ​​of the extracted degree of degradation.

[0071] [Additional Notes] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. [Explanation of Symbols]

[0072] 1. Deterioration diagnostic device 2. Battery storage device 3 BMS 11 Acquisition Department 12 Correction Processing Unit 13 Internal Resistance Calculation Unit 14 Deterioration degree calculation section 15. Deterioration Diagnosis Department 16 Memory section 21-1~21-n Battery Bank 31-1~31-m Battery Module 100 Deterioration Diagnosis System

Claims

1. A degradation diagnostic device for diagnosing the degradation of a battery bank in which multiple modules, each consisting of multiple battery cells connected in series, are connected in series and parallel, At a minimum, an acquisition unit that acquires information regarding the voltage value and current value of each of the multiple modules included in the battery bank, An internal resistance calculation unit that calculates the internal resistance of each of the multiple modules based on the voltage value information and the current value, A degradation degree calculation unit that calculates the degree of degradation of each of the multiple modules based on the internal resistance of the multiple modules, A degradation diagnosis device comprising: a degradation diagnosis unit that diagnoses the degradation of the battery bank based on the degree of degradation of the module that is most degraded among a plurality of the aforementioned modules.

2. The degradation diagnosis device according to claim 1, wherein the degradation diagnosis unit extracts the degree of degradation of the module that is most degraded among the modules in each of the plurality of battery banks, and diagnoses the degradation of the plurality of battery banks based on the difference between the maximum and minimum values ​​of the extracted degree of degradation.

3. The degradation diagnostic device according to claim 1 or 2, wherein the acquisition unit acquires the terminal voltage of the module as information relating to the voltage value.

4. The degradation diagnostic device according to claim 1 or 2, wherein the acquisition unit acquires the highest voltage value of the battery cells in the module as information relating to the voltage value.

5. The degradation diagnostic device according to claim 1 or 2, wherein the acquisition unit acquires the lowest voltage value of the battery cells in the module as information relating to the voltage value.

6. The acquisition unit acquires the internal temperature of each of the multiple modules, The deterioration diagnostic device according to claim 1 or 2, wherein the internal resistance calculation unit corrects the internal resistance of each of the plurality of modules based on the internal temperature.

7. A degradation diagnosis method for diagnosing the degradation of a battery bank in which multiple modules, each consisting of multiple battery cells connected in series, are connected in series and parallel, The steps include, at a minimum, obtaining information regarding the voltage value and current value of each of the multiple modules included in the battery bank, A step of calculating the internal resistance of each of the multiple modules based on the voltage value information and the current value, A step of calculating the degree of degradation of each of the multiple modules based on the internal resistance of the multiple modules, A degradation diagnosis method comprising the step of diagnosing the degradation of the battery bank based on the degree of degradation of the module that is most degraded among a plurality of such modules.

8. The degradation diagnosis method according to claim 7, wherein in the step of diagnosing the degradation, the degree of degradation of the module that is most degraded among the modules in each of the plurality of battery banks is extracted, and the degradation of the plurality of battery banks is diagnosed based on the difference between the maximum and minimum values ​​of the extracted degree of degradation.

9. A program that performs a degradation diagnosis method for diagnosing the degradation of a battery bank in which multiple modules, each consisting of multiple battery cells connected in series, are connected in series and parallel, On the computer, At a minimum, the process involves obtaining information regarding the voltage value and current value of each of the multiple modules included in the battery bank, A process for calculating the internal resistance of each of the multiple modules based on the voltage value information and the current value, A process for calculating the degree of degradation of each of the multiple modules based on the internal resistance of the multiple modules, A program that performs a process to diagnose the degradation of the battery bank based on the degree of degradation of the module that is most degraded among the multiple modules.

10. The program according to claim 9, wherein in the process of diagnosing the degradation, the program extracts the degree of degradation of the module that is most degraded among the modules in each of the plurality of battery banks, and diagnoses the degradation of the plurality of battery banks based on the difference between the maximum and minimum values ​​of the extracted degree of degradation.

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