CN-122025868-A - Battery cell tolerance processing method, battery management system and storage medium

Abstract

The application relates to the technical field of batteries, and provides a battery cell tolerance processing method, a battery management system and a storage medium. The battery cell tolerance processing method comprises the steps of monitoring real-time battery cell voltage and real-time battery cell current of each battery cell in a battery pack when the battery pack is charged, determining a first moment when the maximum value of the battery cell voltage rises to a first voltage threshold value, obtaining the minimum value of the battery cell voltage, respectively determining a second moment when the battery cell voltage corresponding to each battery cell reaches the minimum value based on historical voltage monitoring data of the battery cell voltage corresponding to each battery cell, respectively calculating the charging electric quantity of each battery cell in the period from the corresponding second moment to the first moment based on historical current monitoring data of the battery cell current corresponding to each battery cell, and obtaining tolerance data corresponding to each battery cell. The method can effectively improve the accuracy of calculating tolerance data.

Inventors

• TANG YINGBO
• YANG ANG
• WANG YONGXING
• XU BAIGAO
• WANG LEI
• CHEN XI

Assignees

• 深圳市正浩创新科技股份有限公司

Dates

Publication Date

20260512

Application Date

20250625

Claims (10)

1. 1. A method for processing a tolerance of a cell, the method comprising: monitoring the real-time cell voltage and the real-time cell current of each cell in a battery pack when the battery pack is charged; Determining a first moment when the maximum value of the voltages of the real-time battery cells rises to a first voltage threshold value; obtaining the minimum value in each real-time cell voltage; Based on the historical voltage monitoring data of the real-time cell voltage corresponding to each cell, respectively determining a second moment when the real-time cell voltage corresponding to each cell reaches the minimum value, wherein the second moment is earlier than or equal to the first moment; and respectively calculating the charge electric quantity of each battery cell in the period from the corresponding second moment to the first moment based on the historical current monitoring data of the real-time battery cell current corresponding to each battery cell, and obtaining tolerance data corresponding to each battery cell.
2. 2. The method of claim 1, wherein the method further comprises: Determining the battery cells to be balanced based on tolerance data corresponding to each battery cell; And carrying out tolerance equalization on the battery cells to be equalized.
3. 3. The method of claim 2, wherein determining the cells to be equalized based on the tolerance data corresponding to each of the cells comprises: and determining N cells with the maximum tolerance data as cells to be balanced, wherein N is a preset positive integer.
4. 4. The method of claim 2, wherein the determining the cells to be equalized based on the tolerance data corresponding to each of the cells further comprises: and when the maximum tolerance data is smaller than the first tolerance threshold value, determining that no cell to be balanced exists.
5. 5. The method of claim 2, wherein the method further comprises: obtaining a target equilibrium capacity; The performing tolerance equalization on the to-be-equalized battery cell includes: and carrying out tolerance equalization on the battery cell to be equalized based on the target equalization capacity.
6. 6. The method of claim 5, wherein the obtaining the target equalization capacity comprises: And when the tolerance data corresponding to the battery cells to be balanced is smaller than or equal to a second tolerance threshold value, determining the tolerance data corresponding to the battery cells to be balanced as the target balanced capacity.
7. 7. The method of claim 5, wherein the obtaining the target equalization capacity comprises: And when the tolerance data corresponding to the battery cells to be balanced is larger than a second tolerance threshold, determining the second tolerance threshold as the target balanced capacity.
8. 8. The method of claim 1, wherein the charging phase of the battery pack comprises a current limited charging phase, the first voltage threshold being less than or equal to a starting voltage of the current limited charging phase.
9. 9. A battery management system electrically connected to a battery pack, the battery management system comprising: at least one processor, and A memory communicatively coupled to the at least one processor, wherein the memory stores instructions for execution by the at least one processor to enable the at least one processor to perform the cell tolerance processing method of any one of claims 1-8.
10. 10. A computer readable storage medium having stored therein computer readable instructions for execution by a processor in a battery management system to implement the cell tolerance processing method of any one of claims 1 to 8.

Description

Battery cell tolerance processing method, battery management system and storage medium Technical Field The present invention relates to the field of battery technologies, and in particular, to a battery cell tolerance processing method, a battery management system, and a storage medium. Background In the process of charge and discharge cycle of the battery pack, the battery cells are differentiated in terms of manufacturing parameters, discreteness, material aging characteristics, working environment temperature distribution and the like, so that the battery cells can be differentiated in parameters such as voltage, capacity and temperature. With the increase of the cycle times, the parameter inconsistency presents an accumulated amplification trend, and therefore part of the battery cells enter an overcharging or overdischarging working state. The problem can accelerate the overall performance attenuation of the battery pack, and potential safety hazards such as thermal runaway and the like can be caused when the problem is serious, so that the service life and the safety reliability of the battery pack are obviously restricted. In order to improve the consistency of the battery pack, increase the available capacity of the battery pack and prolong the service life of the battery pack, an equalization means is needed to be adopted when the capacities of the battery cells of the battery pack are inconsistent, and the inconsistency in the battery pack is eliminated. However, tolerance equalization depends on tolerance data, which is usually estimated from the differential pressure between the cells, and has a problem of low accuracy. Disclosure of Invention In view of the foregoing, it is desirable to provide a battery cell tolerance processing method, a battery management system, and a storage medium, which solve the problem of low accuracy of tolerance data calculation. The application provides a battery cell tolerance processing method, which comprises the steps of monitoring real-time battery cell voltage and real-time battery cell current of each battery cell in a battery pack when the battery pack is charged, determining a first moment when the maximum value of the battery cell voltage in the real-time battery cell rises to a first voltage threshold value, obtaining the minimum value of the battery cell voltage in the real-time battery cell, respectively determining a second moment when the battery cell voltage in the real-time battery cell corresponding to each battery cell reaches the minimum value based on historical voltage monitoring data of the battery cell voltage in the real-time battery cell corresponding to each battery cell, wherein the second moment is earlier than or equal to the first moment, and respectively calculating the charge quantity of each battery cell in a period from the corresponding second moment to the first moment based on the historical current monitoring data of the battery cell current in the battery cell corresponding to obtain tolerance data corresponding to each battery cell. The method for processing the tolerance of the battery cell can determine the first moment when the maximum value in the battery cell voltages in real time rises to the first voltage threshold value for the first time, and determine the lowest battery cell voltage corresponding to the first moment, so as to determine the second moment when the battery cell is historically charged to the lowest battery cell voltage, calculate the actual charge capacity of each battery cell according to the current between the first moment and the second moment, and take the charge capacity as tolerance data. Compared with the mode of estimating tolerance data according to the pressure difference between each battery core in the prior art, the accuracy of calculating the tolerance data can be effectively improved. The application further provides a battery cell tolerance processing device which comprises a monitoring module, a determining module, an acquiring module and a determining module, wherein the monitoring module is used for monitoring the real-time battery cell voltage and the real-time battery cell current of each battery cell in a battery pack when the battery pack is charged, the determining module is used for determining a first moment when the maximum value of the battery cell voltage rises to a first voltage threshold value, the acquiring module is used for acquiring the minimum value of the battery cell voltage, the determining module is also used for respectively determining a second moment when the battery cell voltage reaches the minimum value based on the historical voltage monitoring data of the real-time battery cell voltage corresponding to each battery cell, the second moment is earlier than or equal to the first moment, and the processing module is used for respectively calculating the charge quantity of each battery cell during the period from the corresponding second moment to the first mo