CN-121986274-A - Battery diagnosis apparatus, battery diagnosis method, and battery diagnosis system

Abstract

According to some embodiments disclosed in this document, a battery management device is provided that is configured to receive a plurality of rest voltages for a plurality of battery cells, respectively, during a rest period after charging or discharging of the plurality of battery cells has been completed, calculate a plurality of voltage deviations for the plurality of battery cells, respectively, based on differences between each of the plurality of rest voltages for the plurality of battery cells and representative values of the plurality of rest voltages, respectively, calculate rates of change of the plurality of voltage deviations for the plurality of battery cells, respectively, and diagnose a state of at least one battery cell based on the rates of change of at least one battery cell of the plurality of battery cells over time.

Inventors

• Nan Xuanyu

Assignees

• 株式会社LG新能源

Dates

Publication Date

20260505

Application Date

20241017

Priority Date

20231017

Claims (20)

1. 1. A battery management apparatus comprising: A controller including one or more processors, and One or more computer-readable media storing computing instructions that, when executed on the one or more processors, cause the one or more processors to perform: In a rest period after completion of charging or discharging of the plurality of battery cells, receiving a plurality of rest voltages of each of the plurality of battery cells, A plurality of voltage deviations of each of the plurality of battery cells is calculated based on differences between each of the plurality of rest voltages of each of the plurality of battery cells and representative values of the plurality of rest voltages, Calculating a rate of change of the plurality of voltage deviations for each of the plurality of battery cells, and The state of at least one of the plurality of battery cells is diagnosed based on a rate of change of the at least one battery cell over time.
2. 2. The battery management device of claim 1, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: calculating the average value and standard deviation of the change rates of the plurality of battery cells, and Diagnosing whether a low voltage unit is present among the plurality of battery cells based on the average value and the standard deviation.
3. 3. The battery management device of claim 2, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: calculating a standard score of at least one of the plurality of battery cells based on the average value and the standard deviation, and When the standard fraction of the at least one battery cell is below a lower threshold, the at least one battery cell is diagnosed as a low voltage cell.
4. 4. The battery management device of claim 1, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: calculating a plurality of second deviations based on differences between representative values of the plurality of voltage deviations and each of the plurality of voltage deviations, and Diagnosing whether a low voltage unit is present among the plurality of battery cells based on the plurality of second deviations and the rate of change of the plurality of voltage deviations of each of the plurality of battery cells.
5. 5. The battery management device of claim 4, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: setting a normal range of the plurality of battery cells based on the plurality of second deviations and the plurality of rates of change over time, and A battery cell having a second deviation or rate of change outside the normal range is diagnosed as a low voltage cell.
6. 6. The battery management device of claim 1, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: calculating the plurality of voltage deviations for each of the plurality of battery cells based on a median of the plurality of rest voltages for each of the plurality of battery cells, and A slope of each of the plurality of rates of change for each of the plurality of battery cells is estimated by linear regression analysis.
7. 7. The battery management device of claim 1, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: The plurality of rest voltages are received and, Wherein the plurality of rest voltages are collected during a first time period after a buffer time has elapsed from an end time point of charging of the plurality of battery cells, and/or Wherein the plurality of rest voltages are collected during a second time period from an end time point of discharge of the plurality of battery cells.
8. 8. The battery management device of claim 1, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: The rate of change of the plurality of voltage deviations for each of the plurality of battery cells is calculated by regression analysis.
9. 9. The battery management device of claim 1, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: the state of each of the plurality of battery cells is diagnosed based on a rate of change of the plurality of battery cells over time.
10. 10. The battery management device of claim 1, further comprising a sensor configured to collect the plurality of rest voltages for each of the plurality of battery cells in the rest period after completion of charging or discharging of the plurality of battery cells.
11. 11. The battery management device of claim 1, wherein the battery management device further comprises an interface configured to communicate with a sensor to receive the plurality of rest voltages for each of the plurality of battery cells, wherein the sensor is configured to collect the plurality of rest voltages for each of the plurality of battery cells during the rest period after charging or discharging of the plurality of battery cells is complete.
12. 12. The battery management device of claim 1, wherein the computing instructions, when executed on the one or more processors, cause the one or more processors to perform: Diagnosing at least one of the plurality of battery cells as at least one of a low voltage cell and/or an abnormal cell, and In response to the diagnosis, any of i) sending a warning alert to at least one of the user device and the display terminal regarding the at least one diagnosed unit, ii) disconnecting or cutting off power to the at least one diagnosed unit, iii) electrically grounding the at least one diagnosed unit, iv) limiting or modifying at least one of performance, output, and operation mode of an electrical device using the at least one diagnosed unit, and v) sending information regarding the at least one diagnosed unit to an external server.
13. 13. A battery management method implemented via execution of computing instructions configured to run at one or more processors, the battery management method comprising: Receiving a plurality of rest voltages collected for each of a plurality of battery cells in a rest period after completion of charging or discharging of the plurality of battery cells; Calculating a plurality of voltage deviations of each of the plurality of battery cells based on differences between each of the plurality of rest voltages of each of the plurality of battery cells and representative values of the plurality of rest voltages; Calculating a rate of change of the plurality of voltage deviations for each of the plurality of battery cells, and The state of at least one of the plurality of battery cells is diagnosed based on a rate of change of the at least one battery cell.
14. 14. The battery management method of claim 13 wherein diagnosing the status of the at least one of the plurality of battery cells comprises: Calculating the average value and standard deviation of the rates of change of the plurality of battery cells, and Diagnosing whether a low voltage unit is present among the plurality of battery cells based on the average value and the standard deviation.
15. 15. The battery management method of claim 14 wherein diagnosing the status of at least one of the plurality of battery cells comprises: Calculating a standard score of at least one of the plurality of battery cells based on the average value and the standard deviation, and When the standard fraction of the at least one battery cell is below a lower threshold, the at least one battery cell is diagnosed as a low voltage cell.
16. 16. The battery management method of claim 13 wherein diagnosing the status of at least one of the plurality of battery cells comprises: Calculating a plurality of second deviations based on differences between representative values of the plurality of voltage deviations and each of the plurality of voltage deviations, and Diagnosing whether a low voltage unit is present among the plurality of battery cells based on the plurality of second deviations and the rate of change of the plurality of voltage deviations of each of the plurality of battery cells.
17. 17. The battery management method of claim 16 wherein diagnosing the status of at least one of the plurality of battery cells comprises: Setting a normal range of the plurality of battery cells based on the plurality of second deviations and the plurality of rates of change over time, and A battery cell having a second deviation or rate of change outside the normal range is diagnosed as a low voltage cell.
18. 18. The battery management method of claim 13 wherein calculating the plurality of voltage deviations for each of the plurality of battery cells comprises: Calculating the plurality of voltage deviations for each of the plurality of battery cells based on the median of the plurality of rest voltages, and Wherein calculating the plurality of rates of change for the plurality of voltage deviations comprises: a slope of each of the plurality of rates of change for each of the plurality of battery cells is estimated by linear regression analysis.
19. 19. The battery management method of claim 13, wherein receiving the plurality of rest voltages comprises: Receiving a plurality of rest voltages collected during a first time period after a buffer time has elapsed from an end time point of charging of the plurality of battery cells, and A plurality of rest voltages collected during a second time period from an end time point of discharge of the plurality of battery cells is received.
20. 20. A battery management system including the battery management device according to claim 1, the battery management system comprising: A charger/discharger configured to charge or discharge a plurality of battery cells.

Description

Battery diagnosis apparatus, battery diagnosis method, and battery diagnosis system Technical Field Cross Reference to Related Applications The present application claims priority from korean patent application No. 10-2023-0139522, filed on 10 months 17 of 2023, and korean patent application No. 10-2024-0141241, filed on 16 of 10 months 2024, the disclosures of which are incorporated herein by reference. Technical Field The invention relates to a battery diagnosis apparatus, a battery diagnosis method, and a battery diagnosis system. Background Recently, research and development on secondary batteries are actively being conducted. Here, the secondary battery is a battery that can be charged and discharged, and can be interpreted to include a battery that covers both Ni/Cd batteries and Ni/MH batteries, as well as also recently developed lithium ion batteries. Among secondary batteries, lithium ion batteries may have higher energy density than Ni/Cd batteries, ni/MH batteries, and the like, and may be manufactured to be small and lightweight, and thus they may have high usability in power supplies for mobile devices. Recently, the range of use of lithium ion batteries has been expanded to include power sources for electric vehicles, and they are receiving attention as next-generation energy storage media. If a low voltage defect occurs in a specific battery cell, the voltage of the low voltage cell may fluctuate significantly in a stationary state after the completion of charging or discharging, unlike other battery cells. For example, after the completion of charging, a self-discharge phenomenon may occur in the low-voltage cell, which may cause the resting voltage to be lowered to a greater extent than in the case of other battery cells. Such a low voltage phenomenon in the battery cell may cause a fire, and thus it may be necessary to reduce the time required for diagnosis. Disclosure of Invention Technical problem An aspect of the present invention provides a battery diagnosis apparatus, a battery diagnosis method, and a battery diagnosis system, which can reduce the time required to diagnose a low voltage phenomenon in a battery cell. The technical objects of the embodiments disclosed in this document are not limited to the above-mentioned technical problems to be solved, and other technical problems not mentioned to be solved will be clearly understood by those skilled in the art from the following description. Technical solution According to an aspect of the present invention, there is provided a battery management apparatus including a controller including one or more processors, and one or more computer-readable media storing calculation instructions that, when executed on the one or more processors, cause the one or more processors to execute receiving a plurality of rest voltages of each of the plurality of battery cells in a rest period after completion of charging or discharging of the plurality of battery cells, calculating a plurality of voltage deviations of each of the plurality of battery cells based on a difference between the plurality of rest voltages of each of the plurality of battery cells and a representative value of the plurality of rest voltages, calculating a rate of change of the plurality of voltage deviations of each of the plurality of battery cells, and diagnosing a state of at least one battery cell based on the rate of change of at least one battery cell over time of the plurality of battery cells. According to another aspect, the computing instructions, when executed on the one or more processors, cause the one or more processors to perform computing an average and a standard deviation of a rate of change of the plurality of battery cells and diagnosing whether a low voltage cell is present among the plurality of battery cells based on the average and the standard deviation. According to another aspect, the computing instructions, when executed on the one or more processors, cause the one or more processors to perform computing a standard score for at least one battery cell of the plurality of battery cells based on the mean and the standard deviation, and diagnosing the at least one battery cell as a low voltage cell when the standard score for the at least one battery cell is below a lower threshold. According to another aspect, the computing instructions, when executed on the one or more processors, cause the one or more processors to perform computing a plurality of second deviations based on differences between representative values of the plurality of voltage deviations and each of the plurality of voltage deviations, and diagnosing whether a low voltage unit is present among the plurality of battery units based on the plurality of second deviations and a rate of change of the plurality of voltage deviations of each of the plurality of battery units. According to another aspect, the computing instructions, when executed on the one or more processors, cause the one o