Energy storage system battery cell sampling fault diagnosis method and energy storage system

Abstract

The present invention discloses a method for diagnosing a fault in a battery cell sampling of an energy storage system and an energy storage system. The method for diagnosing a fault in a battery cell sampling of an energy storage system comprises: when receiving abnormal battery cell sampling data, obtaining performance parameter information of the abnormal battery cell and performance parameter information of multiple normal battery cells; and determining whether it is a battery cell fault or a sampling fault according to the performance parameter information of the abnormal battery cell and the multiple normal battery cells. The present invention can solve the problem that the existing energy storage system cannot determine the cause of the abnormal data obtained by sampling of a single battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to a method for diagnosing faults of battery cells sampled in energy storage systems and an energy storage system. Background Art

[0002] At present, energy storage systems basically adopt a three-level architecture, and all cell data relies on BMU collection. The collection anomalies directly lead to misjudgment of the upper system, and ultimately cause abnormal operation of the entire system. At the same time, there are many possible reasons for abnormal data of single cell in the energy storage system. If it is impossible to determine the specific reason for the abnormal data obtained by sampling of single cell, it will take a lot of time to troubleshoot the energy storage system, and even the battery pack needs to be disassembled and tested level by level, which makes after-sales maintenance difficult and time-consuming. Summary of the invention

[0003] The main purpose of the present invention is to propose a method for diagnosing faults in battery cell sampling of an energy storage system, aiming to solve the problem that the existing energy storage system cannot determine the cause of abnormal data obtained by sampling of single battery cells.

[0004] To achieve the above-mentioned purpose, the present invention proposes a method for diagnosing faults in a battery cell sampling of an energy storage system, comprising:

[0005] When receiving abnormal cell sampling data, obtaining performance parameter information of the abnormal cell and performance parameter information of multiple normal cells;

[0006] According to the performance parameter information of the abnormal battery cell and the plurality of normal battery cells, it is determined whether it is a battery cell failure or a sampling failure.

[0007] Optionally, the performance parameter information of the plurality of normal battery cells is a set of battery cell capacity values ​​of each of the normal battery cells;

[0008] The performance parameter information of the abnormal battery cell is a collection of battery cell capacity values ​​obtained in each charge and discharge cycle when the abnormal battery cell undergoes multiple charge and discharge cycles; wherein the number of charge and discharge cycles corresponds to the number of normal battery cells.

[0009] Optionally, the step of determining whether a cell failure or a sampling failure is caused by the abnormal cell and the performance parameter information of the plurality of normal cells includes:

[0010] Calculate the difference between the cell capacity value obtained from each charge and discharge cycle of the abnormal cell and the cell capacity value of the normal cell to obtain multiple groups of capacity differences;

[0011] When there is a group of capacity difference values ​​among the multiple groups of capacity difference values ​​that is smaller than the preset capacity difference value, it is determined to be a sampling failure;

[0012] When the capacity differences of multiple groups are all greater than or equal to the preset capacity difference, it is determined to be a battery cell failure.

[0013] Optionally, after the step of determining that a cell fault occurs when the capacity differences of the plurality of groups are greater than or equal to the preset capacity difference, the energy storage system cell sampling fault diagnosis method further includes:

[0014] Acquiring operating parameters of the plurality of normal battery cells and operating parameters of the abnormal battery cells;

[0015] The fault type of the abnormal battery cell is determined according to the operating parameters of the abnormal battery cell and a plurality of normal battery cells.

[0016] Optionally, the operating parameters include a voltage change slope and a temperature change slope;

[0017] The step of determining the fault type of the abnormal battery cell according to the operating parameters of the abnormal battery cell and the plurality of normal battery cells comprises:

[0018] Determining whether the voltage change slope of the abnormal battery cell is abnormal according to the voltage change slopes of the plurality of normal battery cells and the voltage change slope of the abnormal battery cell;

[0019] Determining whether the temperature change slope of the abnormal battery cell is abnormal according to the temperature change slopes of the plurality of normal battery cells and the temperature change slope of the abnormal battery cell;

[0020] The fault type of the abnormal battery cell is determined according to whether the voltage change slope and the temperature change slope of the abnormal battery cell are abnormal.

[0021] Optionally, the step of determining whether the voltage change slope of the abnormal battery cell is abnormal according to the voltage change slopes of the plurality of normal battery cells and the voltage change slope of the abnormal battery cell is specifically:

[0022] The voltage change slopes of multiple normal battery cells are obtained and averaged to obtain an average voltage change slope, and whether the voltage change slope of the abnormal battery cell is abnormal is determined according to the average voltage change slope and the voltage change slope of the abnormal battery cell.

[0023] Optionally, the step of obtaining voltage change slopes of a plurality of normal battery cells and performing average calculation to obtain an average voltage change slope, and determining whether the voltage change slope of the abnormal battery cell is abnormal according to the average voltage change slope and the voltage change slope of the abnormal battery cell comprises:

[0024] Calculate the difference between the average voltage change slope and the voltage change slope of the abnormal battery cell to obtain a voltage slope difference;

[0025] When the voltage slope difference is outside a preset voltage slope difference range, determining that the voltage change slope of the abnormal battery cell is abnormal;

[0026] When the voltage slope difference is within a preset voltage slope difference range, it is determined that the voltage change slope of the abnormal battery cell is normal.

[0027] Optionally, the step of determining whether the temperature change slope of the abnormal battery cell is abnormal according to the temperature change slopes of the plurality of normal battery cells and the temperature change slope of the abnormal battery cell is specifically:

[0028] The temperature change slopes of multiple normal battery cells are obtained and averaged to obtain an average temperature change slope, and whether the temperature change slope of the abnormal battery cell is abnormal is determined according to the average temperature change slope and the temperature change slope of the abnormal battery cell.

[0029] Optionally, the step of acquiring temperature change slopes of a plurality of normal battery cells and performing average calculation to obtain an average temperature change slope, and determining whether the temperature change slope of the abnormal battery cell is abnormal according to the average temperature change slope and the temperature change slope of the abnormal battery cell comprises:

[0030] Calculate the difference between the average temperature change slope and the temperature change slope of the abnormal battery cell to obtain a temperature slope difference;

[0031] When the temperature slope difference is outside a preset temperature slope difference range, determining that the temperature change slope of the abnormal battery cell is abnormal;

[0032] When the temperature slope difference is within a preset temperature slope difference range, it is determined that the temperature change slope of the abnormal battery cell is normal.

[0033] Optionally, according to whether the voltage change slope and the temperature change slope of the abnormal battery cell are abnormal, the step of determining the fault type of the abnormal battery cell is specifically as follows:

[0034] When the voltage change slope and the temperature change slope of the abnormal battery cell are both normal, determining that the fault type of the abnormal battery cell is a non-permanent failure of the battery cell;

[0035] When the voltage change slope of the abnormal battery cell is abnormal, and / or the temperature change slope of the abnormal battery cell is abnormal, it is determined that the fault type of the abnormal battery cell is a suspected permanent failure of the battery cell.

[0036] Optionally, when the voltage change slope of the abnormal battery cell is abnormal, and / or the temperature change slope of the abnormal battery cell is abnormal, after the step of determining that the fault type of the abnormal battery cell is a suspected permanent failure of the battery cell, the energy storage system battery cell sampling fault diagnosis method further includes:

[0037] Obtaining open circuit voltage values ​​of a plurality of the normal battery cells, and performing mean calculation to obtain an open circuit average voltage value;

[0038] Obtaining an open circuit voltage value of the abnormal battery cell;

[0039] Calculate the difference between the open circuit average voltage value and the open circuit voltage value of the abnormal battery cell to obtain an open circuit voltage difference;

[0040] When the open circuit voltage difference is greater than or equal to the preset open circuit voltage difference, determining that the fault type of the battery cell abnormality is permanent battery cell failure;

[0041] When the open circuit voltage difference is less than a preset open circuit voltage difference, it is determined that the fault type of the battery cell abnormality is a non-permanent failure of the battery cell.

[0042] The present invention further provides an energy storage system, comprising:

[0043] A memory storing a cell sampling fault diagnosis program; and

[0044] The processor implements the above-mentioned energy storage system battery cell sampling fault diagnosis method when the battery cell sampling fault diagnosis program is executed by the processor.

[0045] In the technical solution of the present invention, when abnormal cell sampling data is received, the performance parameter information of multiple normal cells and the performance parameter information of abnormal cells are obtained, and then based on the performance parameter information of the abnormal cells and multiple normal cells, it can be determined whether the fault type of the abnormal cell sampling data is a cell fault or a sampling fault. In this way, in practical applications, when abnormal cell sampling data occurs in the energy storage system, the abnormal cell can be diagnosed, and the fault type of the abnormal cell sampling data can be obtained, so that the user can quickly determine the fault type, solving the problem that the existing energy storage system cannot determine the cause of the abnormal data obtained by sampling of a single cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0047] Figure 1 It is a flow chart of an embodiment of a method for diagnosing faults of battery cells sampled in an energy storage system according to the present invention;

[0048] Figure 2 It is a detailed flow chart of an embodiment of a method for diagnosing faults of battery cells sampled in an energy storage system according to the present invention;

[0049] Figure 3 It is a detailed flow chart of an embodiment of a method for diagnosing faults of battery cells sampled in an energy storage system according to the present invention;

[0050] Figure 4 It is a detailed flow chart of an embodiment of a method for diagnosing faults of battery cells sampled in an energy storage system according to the present invention;

[0051] Figure 5 It is a detailed flow chart of an embodiment of a method for diagnosing faults of battery cells sampled in an energy storage system according to the present invention;

[0052] Figure 6 It is a detailed flow chart of an embodiment of a method for diagnosing faults of battery cells sampled in an energy storage system according to the present invention;

[0053] Figure 7 It is a detailed flow chart of an embodiment of a method for diagnosing faults of battery cells sampled in an energy storage system according to the present invention;

[0054] Figure 8 Schematic diagram of the hardware structure of an energy storage system according to an embodiment of the present invention.

[0055] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0058] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0059] At present, most of the existing energy storage systems adopt a three-level system architecture, and the data of the battery cells are all collected by the BMU. The abnormalities collected by the BMU can easily lead to misjudgment of the upper system, and ultimately cause abnormal operation of the entire system. At the same time, there are many possible reasons for the abnormal data of the single battery cells in the energy storage system, such as battery cell abnormalities, sampling chip abnormalities, sampling terminal abnormalities, etc. The abnormal data of the single battery cells will cause a large SOC error in the energy storage system, thereby increasing the difference between the minimum and maximum SOCs. The system cannot meet the full charge and discharge requirements, cannot meet the system calibration capacity, and may even cause system failures and damage. Furthermore, if it is impossible to determine the specific cause of the abnormal data of the single battery cell, it will take a lot of time to troubleshoot the energy storage system, and even the battery packs need to be disassembled and tested step by step, which makes after-sales maintenance difficult and time-consuming.

[0060] To this end, the present invention proposes a method for diagnosing faults in a battery cell sampling of an energy storage system. In one embodiment of the present invention, reference is made to Figure 1 , the energy storage system battery cell sampling fault diagnosis method includes:

[0061] Step S100: when receiving abnormal cell sampling data, obtaining performance parameter information of the abnormal cell and performance parameter information of multiple normal cells;

[0062] In this embodiment, a main control chip for fault diagnosis may be provided, such as MCU, DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), etc., to control the BMS battery management system in the energy storage system to test the battery cells and obtain relevant battery cell performance parameter information from the BMS battery management system. In addition, corresponding test circuits and sampling circuits may also be additionally provided, specifically for implementing this fault diagnosis method.

[0063] When the energy storage system is running, the BMS battery management system in the energy storage system will monitor the battery cell status in real time at different stages, including the charging stage, the discharging stage and the static stage. Among them, during the charging and discharging stage, when the battery cell voltage is in the platform area, if the BMS battery management system detects that the voltage difference between the highest voltage or the lowest voltage of the battery cell and the voltage is more than 30mv, the battery cell data is determined to be abnormal. At this time, the BMS battery management system will send the information of the abnormal battery cell sampling data to the main control chip for fault diagnosis, so that the main control chip can determine the location of the abnormal battery cell and perform fault diagnosis on the abnormal battery cell.

[0064] When the main control chip for fault diagnosis receives information about abnormal cell sampling data, the main control chip will obtain performance parameter information of abnormal cells and normal cells from the BMS battery management system, such as cell capacity, cell voltage, temperature change slope over a period of time, cell open circuit voltage, etc. Alternatively, the main control chip can also control the BMS battery management system to test abnormal cells and normal cells, thereby obtaining performance parameter information of abnormal cells and normal cells.

[0065] Step S200: Determine whether it is a cell failure or a sampling failure based on the performance parameter information of the abnormal cell and the plurality of normal cells.

[0066] It is understandable that when a battery cell fails, the performance parameters of the failed battery cell will be significantly different from those of a normal battery cell, and when sampling is abnormal, the performance parameters of the abnormal battery cell will not be significantly different from those of a normal battery cell. At this time, the data can be collected multiple times and compared with the data of the normal battery cell, or the data can be sampled through other sampling chips or spare sampling chips. If the data is normal, it can be determined that the sampling is abnormal. Therefore, the performance parameter information of the normal battery cell and the performance parameter information of the abnormal battery cell can be processed by calculation, comparison, etc., and based on the processing results, when the battery cell sampling data is abnormal, it can be determined whether it is a battery cell failure or a sampling failure.

[0067] In this embodiment, when the cell sampling data is abnormal, it can be determined whether it is a cell fault or a sampling fault based on the performance parameter information of the normal cell and the abnormal cell. For example, the cell capacity values ​​of multiple normal cells are compared with the cell capacity values ​​obtained by multiple tests of the abnormal cell. When the cell capacity values ​​of the abnormal cell are greatly different from the cell capacity values ​​of multiple normal cells, the capacity of the abnormal cell is determined to be abnormal. At this time, it can be judged that the cell is abnormal, and further judgment is made. After judging that the cell is abnormal, the voltage change rate, temperature change rate and open circuit voltage of the normal cell and the abnormal cell can be obtained for calculation, comparison and other processing, and the cause of the cell abnormality can be further judged based on the processing result. Is the cell permanent failure or non-permanent failure of the cell. It can be understood that only the data of one normal cell can be obtained for comparison and judgment with the data of the abnormal cell, or the data of multiple normal cells can be obtained, and the average value can be taken for comparison and judgment with the data of the abnormal cell, which can improve the accuracy of fault diagnosis. In addition, after determining the specific fault type, the corresponding fault information can be uploaded to the host computer, or displayed through the set display component. According to the fault type, a suitable fault handling plan can also be given to improve the efficiency of fault handling and maintenance.

[0068] In the technical solution of the present invention, when abnormal cell sampling data is received, the performance parameter information of multiple normal cells and the performance parameter information of abnormal cells are obtained, and then the obtained performance parameter information is calculated and processed, and the fault type of the abnormal cell sampling data can be determined based on the processing result, whether it is a cell fault or a sampling fault. In this way, in practical applications, when abnormal cell sampling data occurs in the energy storage system, the abnormal cell can be diagnosed, and the fault type of the abnormal cell sampling data can be obtained, so that the user can quickly determine the fault type and perform fault processing such as deactivation, maintenance, and replacement in a timely manner, which can effectively avoid system failure or damage caused by abnormal cell sampling data, making fault diagnosis more efficient and quick, and improving the efficiency of fault diagnosis and the convenience of user use.

[0069] refer to Figure 2 In one embodiment of the present invention, the performance parameter information of the plurality of normal battery cells is a set of battery cell capacity values ​​of each of the normal battery cells;

[0070] The performance parameter information of the abnormal battery cell is a collection of battery cell capacity values ​​obtained in each charge and discharge cycle when the abnormal battery cell undergoes multiple charge and discharge cycles; wherein the number of charge and discharge cycles corresponds to the number of normal battery cells.

[0071] In this embodiment, when the abnormal cell sampling data is received, the cell capacity values ​​of multiple normal cells and the cell capacity values ​​obtained in each charge and discharge cycle when the abnormal cell undergoes multiple charge and discharge cycles are obtained. Among them, the cell capacity values ​​of normal cells and abnormal cells can be tested and obtained through BMS, or can be obtained through an additional test circuit and sampling circuit specially set for fault diagnosis. The cell capacity can be obtained through test methods such as discharge test method, open circuit voltage method, ampere-hour integration method and Kalman filter method. Optionally, the ampere-hour integration method can be used to obtain the cell capacity values ​​of normal cells and abnormal cells. The ampere-hour integration method is to calculate the capacity value by integrating time and current, and using the charge and discharge rate and temperature correction coefficient as compensation coefficients. The ampere-hour integration method has the advantages of being relatively less restricted by the battery's own conditions, simple and reliable calculation method, and being able to estimate the battery's state of charge in real time, which can improve the accuracy of the obtained cell capacity value.

[0072] The step of determining whether a cell fault or a sampling fault is caused by the abnormal cell and the performance parameter information of the plurality of normal cells comprises:

[0073] S210, calculating the difference between the cell capacity value obtained from each charge and discharge cycle of the abnormal cell and the cell capacity value of the normal cell to obtain multiple groups of capacity differences;

[0074] S220: When one of the multiple groups of capacity difference values ​​is smaller than a preset capacity difference value, it is determined to be a sampling failure;

[0075] When the capacity differences of multiple groups are all greater than or equal to the preset capacity difference, it is determined to be a battery cell failure.

[0076] In this embodiment, after obtaining the cell capacity values ​​of multiple normal cells and the cell capacity values ​​of multiple charge-discharge cycles of abnormal cells, the cell capacity values ​​of multiple normal cells and the cell capacity values ​​of multiple charge-discharge cycles of abnormal cells are calculated one by one, and according to the difference calculation results, it is determined whether the capacity of the abnormal cell is normal, and then the fault type of the abnormal cell sampling data is judged. For example, the cell capacity values ​​of three normal cells and the cell capacity values ​​of three charge-discharge cycles of abnormal cells are obtained. The specific data acquisition process can be to obtain the cell capacity value of a normal cell and the cell capacity value of the abnormal cell during the first charge-discharge cycle by sampling and calculation, and use these two values ​​as a group for difference calculation, and then obtain the cell capacity value of another normal cell and the cell capacity value of the abnormal cell during the second charge-discharge cycle, and use these two values ​​as a group for difference calculation, so that three groups of data are obtained for difference calculation, and then according to the difference calculation results of these three groups, it is determined whether the capacity of the abnormal cell is normal.

[0077] Optionally, the ampere-hour integration method can be used to obtain the cell capacity values ​​of normal cells and abnormal cells, and the preset capacity difference can be set to two ampere hours, or the corresponding preset capacity difference can be set according to the actual energy storage system. If the capacity difference between the cell capacity value of the normal cell and the cell capacity value of the abnormal cell is less than the preset capacity difference, it can be determined that the capacity of the abnormal cell is normal; if the capacity difference between the cell capacity value of the normal cell and the cell capacity value of the abnormal cell is greater than or equal to the preset capacity difference, it can be determined that the capacity of the abnormal cell is abnormal.

[0078] If one of the three sets of difference calculation results shows that the capacity of the abnormal battery cell is normal, the fault type of the abnormal battery cell sampling data is judged to be a sampling fault. If the three sets of difference calculation results show that the capacity of the abnormal battery cell is abnormal, the fault type of the abnormal battery cell sampling data is judged to be a battery cell fault. Furthermore, if it is judged to be a sampling fault, the fault type can be uploaded or displayed so that the user can further troubleshoot the system to determine whether it is a sampling abnormality of the sampling chip or a sampling harness terminal abnormality. If it is judged to be a battery cell fault, other battery cell data can be further obtained for comparison to specifically determine the cause of the battery cell fault.

[0079] In the technical solution of the present invention, when a cell sampling data anomaly is received, a set of cell capacity values ​​of multiple normal cells and a set of cell capacity values ​​obtained in each charge and discharge cycle when the abnormal cell undergoes multiple charge and discharge cycles are obtained, and then the obtained cell capacity values ​​are subjected to difference calculation, and the fault type of the cell sampling data anomaly can be determined to be sampling anomaly or cell anomaly based on the difference calculation result. In this way, in practical applications, when a cell sampling data anomaly occurs in the energy storage system, the abnormal cell can be diagnosed for the fault, and it can be determined whether the fault type of the cell sampling data anomaly is sampling anomaly or cell anomaly, so that the user can quickly determine the fault type based on the result, and timely perform fault processing such as deactivation, maintenance, replacement, or further troubleshooting, and can perform targeted and efficient processing to avoid system failure or damage caused by cell sampling data anomaly, making fault diagnosis more efficient and quick, and improving the efficiency of fault diagnosis and the convenience of user use.

[0080] refer to Figure 3 In one embodiment of the present invention, after the step of determining that a cell fault occurs when the capacity differences of the plurality of groups are greater than or equal to the preset capacity difference, the energy storage system cell sampling fault diagnosis method further includes:

[0081] S300, obtaining operating parameters of a plurality of normal battery cells and operating parameters of the abnormal battery cells;

[0082] In this embodiment, after determining that the fault type of the abnormal cell sampling data is a cell abnormality, the working parameters of the normal cell and the abnormal cell can be obtained, and the working parameters can be calculated, compared, and processed, and then the fault type of the cell abnormality can be determined according to the processing results of the working parameters. Specifically, the working parameters of the cell can be the voltage change slope, the temperature change slope, and the open circuit voltage, and the processing results of the working parameters can be used to further determine whether the cause of the cell abnormality is a permanent cell failure or a non-permanent cell failure. It can be understood that only the data of one normal cell can be obtained for comparison and judgment with the data of the abnormal cell, or the data of multiple normal cells can be obtained, and the average value can be taken for comparison and judgment with the data of the abnormal cell, which can improve the accuracy of fault diagnosis.

[0083] S400: Determine a fault type of the abnormal battery cell according to operating parameters of the abnormal battery cell and a plurality of normal battery cells.

[0084] In this embodiment, the fault type of the abnormal battery cell can be determined based on the working parameters of the normal battery cell and the abnormal battery cell. For example, the average voltage change slope of multiple normal battery cells is compared with the voltage change slope value of the abnormal battery cell. When the difference between the voltage change slope value of the abnormal battery cell and the average voltage change slope value of multiple normal battery cells is within a preset range, it can be determined that the battery cell has a non-permanent failure. If the difference is outside the preset range, further judgment can be made. Further judgment can be made by obtaining the open circuit voltage values ​​of the normal battery cell and the abnormal battery cell for calculation and processing, and finally determining whether the fault type of the abnormal battery cell is a non-permanent failure or a permanent failure based on the calculation and processing results.

[0085] In addition, after determining the specific fault type, the corresponding fault information can be uploaded to the host computer, or displayed through the set display component, and the battery cell to which the abnormal battery cell belongs can be isolated according to the fault type. For example, when it is determined that the fault type of the abnormal battery cell is a permanent failure of the battery cell in the No. 1 single battery, the No. 1 single battery can be permanently isolated, such as removing the No. 1 single battery from the battery pack or disconnecting the No. 1 single battery.

[0086] In the technical solution of the present invention, when it is determined that the fault type of the abnormal cell sampling data is a cell abnormality, the working parameters of multiple normal cells and the working parameters of the abnormal cell are obtained, and then the obtained working parameters are calculated, compared, etc., and according to the processing results, it can be determined whether the fault type of the abnormal cell is a permanent cell failure or a non-permanent cell failure, and the corresponding fault isolation processing can be performed on the battery cell to which the abnormal cell belongs, and the fault type information of the abnormal cell is uploaded. In this way, in practical applications, when the cell sampling data is abnormal in the energy storage system, the abnormal cell can be diagnosed, and the fault type of the abnormal cell sampling data is obtained as sampling abnormality, permanent cell failure or non-permanent cell failure. At the same time, the fault type can also be uploaded or displayed, so that the user can quickly obtain the diagnosis result and quickly determine the fault type according to the result. In addition, after determining the specific cause of the cell failure, the abnormal battery cell can also be automatically isolated, and the faulty single battery can be isolated in time to avoid system failure or damage caused by cell abnormality or untimely abnormal discovery of the user, making fault diagnosis more efficient and intelligent, and improving the safety of the energy storage system.

[0087] refer to Figures 4 to 6 , in one embodiment of the present invention, the operating parameters include a voltage change slope and a temperature change slope;

[0088] In the present embodiment, after determining that the fault type of the abnormal cell sampling data is a cell abnormality, the voltage change slope values ​​and temperature change slope values ​​of multiple normal cells, as well as the voltage change slope values ​​and temperature change slope values ​​of abnormal cells are obtained. The voltage change slope values ​​and temperature change slope values ​​of normal cells and abnormal cells can be tested and obtained through the BMS, or can be obtained through an additional test circuit and sampling circuit specifically used for fault diagnosis. The voltage change slope value and the temperature change slope value can be obtained by testing during the cell charging process, or by testing during the cell discharging process, or by testing during the entire charging and discharging process. It can be understood that in addition to obtaining the voltage change slope value and the temperature change slope value for comparison, the voltage change curve and the temperature change curve can also be obtained for comparison, and the fault type of the cell abnormality can be determined based on the comparison result.

[0089] The step of determining the fault type of the abnormal battery cell according to the operating parameters of the abnormal battery cell and the plurality of normal battery cells comprises:

[0090] S410, determining whether the voltage change slope of the abnormal battery cell is abnormal according to the voltage change slopes of the plurality of normal battery cells and the voltage change slope of the abnormal battery cell;

[0091] In this embodiment, the voltage change slopes of multiple normal cells and the voltage change slope of abnormal cells are obtained for calculation, comparison and other processing, and based on the processing results, it is determined whether the voltage change slope of the abnormal cell is normal, and then the specific fault type of the abnormal cell is determined. It can be understood that if the numerical difference between the voltage change slope of the normal cell and the voltage change slope of the abnormal cell is within the preset range, it can be determined that the voltage change trend of the abnormal cell is normal, and if the numerical difference between the voltage change slope of the normal cell and the voltage change slope of the abnormal cell is outside the preset range, it can be determined that the voltage change trend of the abnormal cell is abnormal.

[0092] Optionally, the step of determining whether the voltage change slope of the abnormal battery cell is abnormal according to the voltage change slopes of the plurality of normal battery cells and the voltage change slope of the abnormal battery cell is specifically:

[0093] S411. Obtain voltage change slopes of multiple normal battery cells, and perform mean calculation to obtain an average voltage change slope, and determine whether the voltage change slope of the abnormal battery cell is abnormal based on the average voltage change slope and the voltage change slope of the abnormal battery cell.

[0094] In this embodiment, the voltage change slopes of multiple normal cells are obtained, and the mean is calculated to obtain the average voltage change slope, and whether the voltage change slope of the abnormal cell is abnormal is determined based on the average voltage change slope and the voltage change slope of the abnormal cell, and then the specific fault type of the abnormal cell is determined. For example, after obtaining the voltage change slopes of three normal cells and an abnormal cell, the mean is calculated to calculate the average voltage change slope of the three normal cells, and the difference between the average voltage change slope and the voltage change slope of the abnormal cell is calculated, so as to determine whether the voltage change slope of the abnormal cell is abnormal based on the difference calculation result.

[0095] Optionally, the step of obtaining voltage change slopes of a plurality of normal battery cells and performing average calculation to obtain an average voltage change slope, and determining whether the voltage change slope of the abnormal battery cell is abnormal according to the average voltage change slope and the voltage change slope of the abnormal battery cell comprises:

[0096] S401, calculating the difference between the average voltage change slope and the voltage change slope of the abnormal battery cell to obtain a voltage slope difference;

[0097] S402, when the voltage slope difference is outside a preset voltage slope difference range, determining that the voltage change slope of the abnormal battery cell is abnormal;

[0098] When the voltage slope difference is within a preset voltage slope difference range, it is determined that the voltage change slope of the abnormal battery cell is normal.

[0099] In this embodiment, the calculated average voltage change slope and the voltage change slope value of the abnormal battery cell are subjected to a difference calculation, so as to determine whether the voltage change slope of the abnormal battery cell is abnormal based on the difference calculation result. Specifically, if the numerical difference between the average voltage change slope of the normal battery cell and the voltage change slope of the abnormal battery cell is within the preset voltage slope difference range, it can be determined that the voltage change trend of the abnormal battery cell is normal. If the numerical difference between the average voltage change slope of the normal battery cell and the voltage change slope of the abnormal battery cell is outside the preset voltage slope difference range, it can be determined that the voltage change trend of the abnormal battery cell is abnormal. Optionally, the preset voltage slope difference range can be set to -1% to 1% of the average voltage change slope.

[0100] S420, determining whether the temperature change slope of the abnormal battery cell is abnormal according to the temperature change slopes of the plurality of normal battery cells and the temperature change slope of the abnormal battery cell;

[0101] In this embodiment, the temperature change slopes of multiple normal cells and the temperature change slopes of abnormal cells are obtained for calculation, comparison and other processing, and based on the processing results, it is determined whether the temperature change slope of the abnormal cell is normal, and then the specific fault type of the abnormal cell is determined. It can be understood that if the numerical difference between the temperature change slope of the normal cell and the temperature change slope of the abnormal cell is within a preset range, it can be determined that the temperature change trend of the abnormal cell is normal, and if the numerical difference between the temperature change slope of the normal cell and the temperature change slope of the abnormal cell is outside the preset range, it can be determined that the temperature change trend of the abnormal cell is abnormal.

[0102] Optionally, the step of determining whether the temperature change slope of the abnormal battery cell is abnormal according to the temperature change slopes of the plurality of normal battery cells and the temperature change slope of the abnormal battery cell is specifically:

[0103] S421. Obtain temperature change slopes of multiple normal battery cells and perform average calculation to obtain an average temperature change slope, and determine whether the temperature change slope of the abnormal battery cell is abnormal based on the average temperature change slope and the temperature change slope of the abnormal battery cell.

[0104] In this embodiment, the temperature change slopes of multiple normal cells are obtained, and the mean is calculated to obtain the average temperature change slope, and whether the temperature change slope of the abnormal cell is abnormal is determined based on the average temperature change slope and the temperature change slope of the abnormal cell, and then the specific fault type of the abnormal cell is determined. For example, after obtaining the temperature change slopes of three normal cells and the abnormal cell, the mean is calculated to calculate the average temperature change slope of the three normal cells, and the difference between the average temperature change slope and the temperature change slope value of the abnormal cell is calculated, so as to determine whether the temperature change slope of the abnormal cell is abnormal based on the difference calculation result.

[0105] Optionally, the step of acquiring temperature change slopes of a plurality of normal battery cells and performing average calculation to obtain an average temperature change slope, and determining whether the temperature change slope of the abnormal battery cell is abnormal according to the average temperature change slope and the temperature change slope of the abnormal battery cell comprises:

[0106] S403, calculating the difference between the average temperature change slope and the temperature change slope of the abnormal battery cell to obtain a temperature slope difference;

[0107] S404, when the temperature slope difference is outside a preset temperature slope difference range, determining that the temperature change slope of the abnormal battery cell is abnormal;

[0108] When the temperature slope difference is within a preset temperature slope difference range, it is determined that the temperature change slope of the abnormal battery cell is normal.

[0109] In this embodiment, the calculated average temperature change slope and the temperature change slope value of the abnormal battery cell are subjected to a difference calculation, so as to determine whether the temperature change slope of the abnormal battery cell is abnormal based on the difference calculation result. Specifically, if the numerical difference between the average temperature change slope of the normal battery cell and the temperature change slope of the abnormal battery cell is within the preset temperature slope difference range, it can be determined that the temperature change trend of the abnormal battery cell is normal; if the numerical difference between the average temperature change slope of the normal battery cell and the temperature change slope of the abnormal battery cell is outside the preset temperature slope difference range, it can be determined that the temperature change trend of the abnormal battery cell is abnormal. Optionally, the preset temperature slope difference range can be set to -1% to 1% of the average temperature change slope.

[0110] S430 , determining a fault type of the abnormal battery cell according to whether a voltage change slope and a temperature change slope of the abnormal battery cell are abnormal.

[0111] In this embodiment, the fault type of the abnormal battery cell may be determined based on whether the voltage change slope of the abnormal battery cell is normal and whether the temperature change slope of the abnormal battery cell is normal.

[0112] Optionally, according to whether the voltage change slope and the temperature change slope of the abnormal battery cell are abnormal, the step of determining the fault type of the abnormal battery cell is specifically as follows:

[0113] S431, when the voltage change slope and the temperature change slope of the abnormal battery cell are both normal, determining that the fault type of the abnormal battery cell is a non-permanent failure of the battery cell;

[0114] When the voltage change slope of the abnormal battery cell is abnormal, and / or the temperature change slope of the abnormal battery cell is abnormal, it is determined that the fault type of the abnormal battery cell is a suspected permanent failure of the battery cell.

[0115] In this embodiment, if the voltage change slope and temperature change slope of the abnormal battery cell are both normal, it can be determined that the abnormal battery cell fault type is a non-permanent battery cell failure. If any of the voltage change slope and temperature change slope of the abnormal battery cell is abnormal, it can be determined that the abnormal battery cell fault type is a suspected permanent battery cell failure. At this time, other working parameters of the normal battery cell and the abnormal battery cell can be further obtained for processing, so as to determine the cause of the battery cell failure based on the processing results.

[0116] In the technical solution of the present invention, when determining that the fault type of the abnormal cell sampling data is a cell abnormality, the voltage change slope and temperature change slope of the abnormal cell and multiple normal cells are obtained, and then the acquired data are averaged, calculated, and the difference is calculated, and the fault type of the abnormal cell can be determined based on the calculation result as suspected permanent cell failure or non-permanent cell failure. In this way, in practical applications, when the cell sampling data is abnormal in the energy storage system, the abnormal cell can be diagnosed, and the specific fault type of the abnormal cell sampling data is obtained as sampling abnormality, permanent cell failure, or non-permanent cell failure, and multiple sets of data are used for abnormal judgment, which improves the accuracy of fault diagnosis.

[0117] refer to Figure 7 In one embodiment of the present invention, when the voltage change slope of the abnormal battery cell is abnormal, and / or the temperature change slope of the abnormal battery cell is abnormal, after the step of determining that the fault type of the abnormal battery cell is a suspected permanent failure of the battery cell, the energy storage system battery cell sampling fault diagnosis method further includes:

[0118] S510, obtaining open circuit voltage values ​​of a plurality of normal battery cells, and performing mean calculation to obtain an open circuit average voltage value;

[0119] S520, obtaining the open circuit voltage value of the abnormal battery cell;

[0120] S530, calculating the difference between the open circuit average voltage value and the open circuit voltage value of the abnormal battery cell to obtain an open circuit voltage difference;

[0121] S540, when the open circuit voltage difference is greater than or equal to a preset open circuit voltage difference, determining that the fault type of the battery cell abnormality is permanent battery cell failure;

[0122] When the open circuit voltage difference is less than a preset open circuit voltage difference, it is determined that the fault type of the battery cell abnormality is a non-permanent failure of the battery cell.

[0123] In this embodiment, the open circuit voltage values ​​of the abnormal cell and multiple normal cells are obtained, and the open circuit voltage values ​​of multiple normal cells are averaged to obtain the open circuit average voltage value, and the difference between the open circuit average voltage values ​​of multiple normal cells and the open circuit voltage value of the abnormal cell is calculated, and the open circuit voltage difference obtained by the difference calculation is used to determine whether the open circuit voltage value of the abnormal cell is normal, and then the specific fault type of the abnormal cell is determined. For example, after obtaining the open circuit voltage values ​​of the abnormal cell and five normal cells, the open circuit average voltage value of the five normal cells is calculated, and the difference between the open circuit average voltage value of the five normal cells and the open circuit voltage value of the abnormal cell is calculated, so as to determine whether the open circuit voltage of the abnormal cell is normal according to the difference calculation result.

[0124] If the difference between the open circuit average voltage value of the normal cell and the open circuit voltage value of the abnormal cell is greater than or equal to the preset open circuit voltage difference, the open circuit voltage value of the abnormal cell is determined to be abnormal. If the difference between the open circuit average voltage value of the normal cell and the open circuit voltage value of the abnormal cell is less than the preset open circuit voltage difference, the open circuit voltage value of the abnormal cell is determined to be normal. Optionally, the preset open circuit voltage difference can be set to 5mV.

[0125] Specifically, if the open circuit voltage value of the abnormal cell is abnormal, the fault type of the abnormal cell can be determined to be permanent cell failure. If the open circuit voltage value of the abnormal cell is normal, the fault type of the abnormal cell can be determined to be non-permanent cell failure.

[0126] In the technical solution of the present invention, when it is determined that the fault type of the abnormal cell sampling data is a cell abnormality, the voltage change slope, temperature change slope and open circuit voltage value of the abnormal cell and multiple normal cells are obtained, and then the acquired data are averaged, calculated, and the difference is calculated, and the fault type of the abnormal cell can be determined according to the calculation result, whether the cell is permanently failed or the cell is not permanently failed. In this way, in practical applications, when the cell sampling data is abnormal in the energy storage system, the abnormal cell can be diagnosed, and the fault type of the abnormal cell sampling data is obtained, which is specifically sampling abnormality, permanent failure of the cell or non-permanent failure of the cell, and multiple groups of data are used for abnormal judgment, which improves the accuracy of fault diagnosis. In addition, the user can quickly determine the fault type according to the result, and timely perform fault processing such as deactivation, maintenance, replacement, or further troubleshooting, and can carry out targeted and efficient processing to avoid system failure or damage caused by abnormal cell sampling data, making fault diagnosis more efficient and quick, and improving the efficiency of fault diagnosis and the convenience of user use.

[0127] The present invention also provides an energy storage system, which includes:

[0128] A memory storing a cell sampling fault diagnosis program; and

[0129] The processor implements the above-mentioned energy storage system battery cell sampling fault diagnosis method when the battery cell sampling fault diagnosis program is executed by the processor.

[0130] like Figure 8 As shown, Figure 8 Schematic diagram of the hardware structure of the energy storage system. The energy storage system may include: a processor 1001, such as a CPU (Central Processing Unit), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Those skilled in the art will understand that Figure 6 The hardware structure shown in the figure does not constitute a limitation on the control device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0131] Specifically, the communication bus 1002 is used to realize the connection and communication between these components;

[0132] The user interface 1003 is used to connect to the client and perform data communication with the client. The user interface 1003 may include an output unit, such as a display screen, and an input unit, such as a keyboard;

[0133] The network interface 1004 is used to connect to the backend server and perform data communication with the backend server. The network interface 1004 may include an input / output interface, such as a standard wired interface, a wireless interface, such as a Wi-Fi interface;

[0134] The memory 1005 is used to store various types of data, which may include, for example, instructions of any application or method in the control device, and data related to the application. The memory 1005 may be a high-speed RAM memory, or a stable memory, such as a disk memory. Optionally, the memory 1005 may also be a storage device independent of the processor 1001.

[0135] For details, please refer to Figure 8 , the memory 1005 may include an operating system, a network communication module, a user interface module, and a wireless charging start control program, wherein the network communication module may be used to connect to a server and perform data communication with the server;

[0136] The processor 1001 can be a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor or other electronic components. The processor 1001 is used to call the battery cell sampling fault diagnosis program stored in the memory 1005, and execute all or part of the steps of each embodiment of the battery cell sampling fault diagnosis method for the energy storage system.

[0137] It is worth noting that since the energy storage system of the present invention is based on the above-mentioned energy storage system battery cell sampling fault diagnosis method, the embodiments of the energy storage system of the present invention include all technical solutions of all embodiments of the above-mentioned energy storage system battery cell sampling fault diagnosis method, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0138] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for diagnosing faults in a battery cell sampling of an energy storage system, characterized in that: include: When receiving abnormal cell sampling data, obtaining performance parameter information of the abnormal cell and performance parameter information of multiple normal cells; The performance parameter information of the plurality of normal battery cells is a collection of battery cell capacity values ​​of each of the normal battery cells; the performance parameter information of the abnormal battery cells is a collection of battery cell capacity values ​​obtained in each charge and discharge cycle when the abnormal battery cells undergo multiple charge and discharge cycles; wherein the number of charge and discharge cycles corresponds to the number of normal battery cells; Determine whether it is a cell failure or a sampling failure according to the performance parameter information of the abnormal cell and the plurality of normal cells; Wherein, the step of determining whether it is a cell failure or a sampling failure according to the performance parameter information of the abnormal cell and the plurality of normal cells comprises: Calculate the difference between the cell capacity value obtained from each charge and discharge cycle of the abnormal cell and the cell capacity value of the normal cell to obtain multiple groups of capacity differences; When there is a group of capacity difference values ​​among the multiple groups of capacity difference values ​​that is smaller than the preset capacity difference value, it is determined to be a sampling failure; When the capacity differences of multiple groups are all greater than or equal to the preset capacity difference, it is determined to be a battery cell failure.

2. The energy storage system cell sampling fault diagnosis method according to claim 1, characterized in that: After the step of determining that a cell fault occurs when the capacity differences of the plurality of groups are greater than or equal to the preset capacity difference, the energy storage system cell sampling fault diagnosis method further includes: Acquiring operating parameters of the plurality of normal battery cells and operating parameters of the abnormal battery cells; The fault type of the abnormal battery cell is determined according to the operating parameters of the abnormal battery cell and a plurality of normal battery cells.

3. The energy storage system cell sampling fault diagnosis method according to claim 2, characterized in that: The operating parameters include voltage change slope and temperature change slope; The step of determining the fault type of the abnormal battery cell according to the operating parameters of the abnormal battery cell and the plurality of normal battery cells comprises: Determining whether the voltage change slope of the abnormal battery cell is abnormal according to the voltage change slopes of the plurality of normal battery cells and the voltage change slope of the abnormal battery cell; Determining whether the temperature change slope of the abnormal battery cell is abnormal according to the temperature change slopes of the plurality of normal battery cells and the temperature change slope of the abnormal battery cell; The fault type of the abnormal battery cell is determined according to whether the voltage change slope and the temperature change slope of the abnormal battery cell are abnormal.

4. The energy storage system cell sampling fault diagnosis method according to claim 3, characterized in that: The step of determining whether the voltage change slope of the abnormal battery cell is abnormal according to the voltage change slopes of the plurality of normal battery cells and the voltage change slope of the abnormal battery cell is specifically as follows: The voltage change slopes of multiple normal battery cells are obtained and averaged to obtain an average voltage change slope, and whether the voltage change slope of the abnormal battery cell is abnormal is determined according to the average voltage change slope and the voltage change slope of the abnormal battery cell.

5. The energy storage system cell sampling fault diagnosis method according to claim 4, characterized in that: The steps of obtaining voltage change slopes of a plurality of normal battery cells and performing average calculation to obtain an average voltage change slope, and determining whether the voltage change slope of the abnormal battery cell is abnormal according to the average voltage change slope and the voltage change slope of the abnormal battery cell include: Calculate the difference between the average voltage change slope and the voltage change slope of the abnormal battery cell to obtain a voltage slope difference; When the voltage slope difference is outside a preset voltage slope difference range, determining that the voltage change slope of the abnormal battery cell is abnormal; When the voltage slope difference is within a preset voltage slope difference range, it is determined that the voltage change slope of the abnormal battery cell is normal.

6. The energy storage system cell sampling fault diagnosis method according to claim 3, characterized in that: The step of determining whether the temperature change slope of the abnormal battery cell is abnormal according to the temperature change slopes of the plurality of normal battery cells and the temperature change slope of the abnormal battery cell is specifically: The temperature change slopes of multiple normal battery cells are obtained and averaged to obtain an average temperature change slope, and whether the temperature change slope of the abnormal battery cell is abnormal is determined according to the average temperature change slope and the temperature change slope of the abnormal battery cell.

7. The energy storage system cell sampling fault diagnosis method according to claim 6, characterized in that: The steps of obtaining temperature change slopes of a plurality of normal battery cells and performing average calculation to obtain an average temperature change slope, and determining whether the temperature change slope of the abnormal battery cell is abnormal according to the average temperature change slope and the temperature change slope of the abnormal battery cell include: Calculate the difference between the average temperature change slope and the temperature change slope of the abnormal battery cell to obtain a temperature slope difference; When the temperature slope difference is outside a preset temperature slope difference range, determining that the temperature change slope of the abnormal battery cell is abnormal; When the temperature slope difference is within a preset temperature slope difference range, it is determined that the temperature change slope of the abnormal battery cell is normal.

8. The energy storage system cell sampling fault diagnosis method according to claim 3, characterized in that: According to whether the voltage change slope and the temperature change slope of the abnormal battery cell are abnormal, the steps of determining the fault type of the abnormal battery cell are specifically as follows: When the voltage change slope and the temperature change slope of the abnormal battery cell are both normal, determining that the fault type of the abnormal battery cell is a non-permanent failure of the battery cell; When the voltage change slope of the abnormal battery cell is abnormal, and / or the temperature change slope of the abnormal battery cell is abnormal, it is determined that the fault type of the abnormal battery cell is a suspected permanent failure of the battery cell.

9. The energy storage system cell sampling fault diagnosis method according to claim 8, characterized in that: When the voltage change slope of the abnormal battery cell is abnormal, and / or the temperature change slope of the abnormal battery cell is abnormal, after the step of determining that the fault type of the abnormal battery cell is a suspected permanent failure of the battery cell, the energy storage system battery cell sampling fault diagnosis method further includes: Obtaining open circuit voltage values ​​of a plurality of the normal battery cells, and performing mean calculation to obtain an open circuit average voltage value; Obtaining an open circuit voltage value of the abnormal battery cell; Calculate the difference between the open circuit average voltage value and the open circuit voltage value of the abnormal battery cell to obtain an open circuit voltage difference; When the open circuit voltage difference is greater than or equal to the preset open circuit voltage difference, determining that the fault type of the battery cell abnormality is permanent battery cell failure; When the open circuit voltage difference is less than a preset open circuit voltage difference, it is determined that the fault type of the battery cell abnormality is a non-permanent failure of the battery cell.

10. An energy storage system, characterized in that: include: A memory storing a cell sampling fault diagnosis program; as well as, A processor, wherein when the cell sampling fault diagnosis program is executed by the processor, the energy storage system cell sampling fault diagnosis method according to any one of claims 1 to 9 is implemented.

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