CN-121989755-A - Battery pack balancing method, battery management system, vehicle and storage medium

CN121989755ACN 121989755 ACN121989755 ACN 121989755ACN-121989755-A

Abstract

The application provides a battery pack balancing method, a battery management system, a vehicle and a storage medium, and relates to the technical field of battery management, wherein the battery pack balancing method comprises the steps of performing online balancing on each battery monomer in a battery pack when the battery management system is in a wake-up mode; under the condition that preset dormancy conditions are met, determining target battery cells to be subjected to offline equalization in the battery pack according to each cell voltage of the battery pack, the highest temperature of the battery pack and the circuit board temperature of the battery sampling chip, sending an offline equalization instruction to the battery sampling chip, and controlling a battery management system to enter a dormancy mode, wherein the offline equalization instruction is used for instructing the battery sampling chip to perform offline equalization on the target battery cells. The application can solve the problem of insufficient balance capacity of the battery management system.

Inventors

GAO PENGYUAN

Assignees

蜂巢能源科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260226

Claims (10)

1. A battery pack equalization method, comprising: When the battery management system is in an awakening mode, performing online equalization on each battery cell in the battery pack; Under the condition that a preset dormancy condition is met, determining a target battery cell to be subjected to offline equalization in the battery pack according to each cell voltage of the battery pack, the highest temperature of the battery pack and the circuit board temperature of a battery sampling chip; And sending an offline balancing instruction to the battery sampling chip and controlling the battery management system to enter a sleep mode, wherein the offline balancing instruction is used for indicating the battery sampling chip to perform offline balancing on the target battery cell.
2. The battery pack balancing method according to claim 1, wherein the determining the target battery cell to be offline balanced in the battery pack according to each cell voltage of the battery pack, a highest temperature of the battery pack, and a circuit board temperature of a battery sampling chip comprises: Determining the maximum number of battery cells for the battery sampling chip to perform offline equalization based on the highest temperature of the battery pack; determining the order in which each battery cell in the battery pack performs an offline balancing test based on each cell voltage of the battery pack; determining each predicted cell from the battery pack based on the maximum number of cells and the order; And according to the sequence, controlling the battery sampling chip to sequentially execute offline balancing tests on the predicted battery monomers, and determining the target battery monomers to be subjected to offline balancing in the battery pack according to the temperature of the circuit board of the battery sampling chip in the process of executing the offline balancing tests.
3. The battery pack balancing method according to claim 2, wherein the determining the target battery cell to be subjected to offline balancing in the battery pack according to the circuit board temperature of the battery sampling chip during the performing of the offline balancing test comprises: When the battery sampling chip is controlled to execute offline balancing test on a first number of predicted battery monomers, the temperature of a circuit board of the battery sampling chip is less than or equal to a temperature threshold value, and when the battery sampling chip is controlled to execute offline balancing test on a second number of predicted battery monomers, the first number of predicted battery monomers are determined to be target battery monomers to be executed offline balancing in the battery pack under the condition that the temperature of the circuit board of the battery sampling chip is greater than the temperature threshold value; wherein the second number is equal to the first number plus one.
4. The battery pack equalization method of claim 1, wherein after said controlling said battery management system to enter a sleep mode, said method further comprises: under the condition that a preset wake-up condition is met, controlling the battery management system to enter a wake-up mode; obtaining the residual balanced electric quantity of each battery monomer when the last time enters the sleep mode, and obtaining the actual balanced electric quantity of each battery monomer in the offline balancing process; determining the latest equalized electric quantity of each battery cell based on the residual equalized electric quantity and the actual equalized electric quantity; And performing on-line equalization on each battery cell based on the latest equalized electric quantity.
5. The battery pack equalization method of claim 4, wherein said controlling the battery management system to enter the wake-up mode if a preset wake-up condition is met comprises: Acquiring a first duration of the battery management system entering a sleep mode, and controlling the battery management system to enter an awake mode when the first duration reaches a first preset duration; The method further comprises the steps of: acquiring a second duration of the battery management system entering the wake-up mode, and when the second duration reaches a second preset duration, sending an offline equalization instruction to the battery sampling chip, and controlling the battery management system to enter the sleep mode.
6. The battery pack balancing method according to claim 4, wherein the obtaining the actual balancing electric quantity of each battery cell in the offline balancing process includes: estimating the equalizing current in the offline equalizing process based on the temperature of the circuit board of the battery sampling chip when the last time enters the sleep mode, the temperature of the circuit board of the battery sampling chip when the last time enters the wake mode, each single voltage when the last time enters the sleep mode and each single voltage when the last time enters the wake mode; and determining the actual balanced electric quantity of each battery cell in the offline balancing process based on the balanced current and the actual balancing time length of the offline balancing process.
7. The battery pack equalization method of claim 4, further comprising: Judging whether a battery cell for actually executing offline balancing is consistent with the target battery cell, whether the actual offline balancing time length is consistent with the requested offline balancing time length, whether each cell voltage is lower than a requested voltage threshold value when the wake-up mode is entered, and whether the temperature of a circuit board of a battery sampling chip is lower than a preset temperature when the wake-up mode is entered; and determining that the offline balancing process is reasonable under the conditions that the battery cell for actually executing the offline balancing is consistent with the target battery cell, the actual offline balancing time length is consistent with the offline balancing time length, each cell voltage is lower than the threshold value of the request voltage when the wake-up mode is entered, and the temperature of the circuit board of the battery sampling chip is lower than the preset temperature when the wake-up mode is entered.
8. The battery management system is characterized by comprising a main controller and a battery sampling chip, wherein the main controller is connected with the battery sampling chip; The main controller for implementing the battery pack balancing method according to any one of claims 1 to 7; The battery sampling chip is used for performing off-line equalization on the target battery cell.
9. A vehicle comprising the battery management system of claim 8.
10. A storage medium having stored thereon a computer program which, when executed by a processor, implements the battery pack balancing method according to any one of claims 1 to 7.

Description

Battery pack balancing method, battery management system, vehicle and storage medium Technical Field The present application relates to the field of battery management technologies, and in particular, to a battery pack balancing method, a battery management system, a vehicle, and a storage medium. Background The battery pack of the new energy automobile comprises a plurality of battery cells, and in the use process of the battery pack, the battery cells are required to be balanced to solve the problem of inconsistent electric energy among the battery cells. At present, a battery management system in a new energy automobile develops an equalization circuit to perform passive equalization, and an equalization scheme judges on line for the battery management system to start on-line equalization, so that the on-line equalization time is shorter, the equalization effect is poorer, and the equalization capacity is insufficient. Disclosure of Invention The application provides a battery pack balancing method, a battery management system, a vehicle and a storage medium, which are used for solving the problem that the battery management system is insufficient in balancing capacity. According to a first aspect of an embodiment of the present application, there is provided a battery pack equalization method, including: When the battery management system is in an awakening mode, performing online equalization on each battery cell in the battery pack; Under the condition that a preset dormancy condition is met, determining a target battery cell to be subjected to offline equalization in the battery pack according to each cell voltage of the battery pack, the highest temperature of the battery pack and the circuit board temperature of a battery sampling chip; And sending an offline balancing instruction to the battery sampling chip and controlling the battery management system to enter a sleep mode, wherein the offline balancing instruction is used for indicating the battery sampling chip to perform offline balancing on the target battery cell. Optionally, the determining the target battery cell to be offline balanced in the battery pack according to each cell voltage of the battery pack, the highest temperature of the battery pack and the circuit board temperature of the battery sampling chip includes: Determining the maximum number of battery cells for the battery sampling chip to perform offline equalization based on the highest temperature of the battery pack; determining the order in which each battery cell in the battery pack performs an offline balancing test based on each cell voltage of the battery pack; determining each predicted cell from the battery pack based on the maximum number of cells and the order; And according to the sequence, controlling the battery sampling chip to sequentially execute offline balancing tests on the predicted battery monomers, and determining the target battery monomers to be subjected to offline balancing in the battery pack according to the temperature of the circuit board of the battery sampling chip in the process of executing the offline balancing tests. Optionally, in the process of performing the offline balancing test, determining the target battery cell to be performed offline balancing in the battery pack according to the circuit board temperature of the battery sampling chip includes: When the battery sampling chip is controlled to execute offline balancing test on a first number of predicted battery monomers, the temperature of a circuit board of the battery sampling chip is less than or equal to a temperature threshold value, and when the battery sampling chip is controlled to execute offline balancing test on a second number of predicted battery monomers, the first number of predicted battery monomers are determined to be target battery monomers to be executed offline balancing in the battery pack under the condition that the temperature of the circuit board of the battery sampling chip is greater than the temperature threshold value; wherein the second number is equal to the first number plus one. Optionally, after the controlling the battery management system to enter the sleep mode, the method further includes: under the condition that a preset wake-up condition is met, controlling the battery management system to enter a wake-up mode; obtaining the residual balanced electric quantity of each battery monomer when the last time enters the sleep mode, and obtaining the actual balanced electric quantity of each battery monomer in the offline balancing process; determining the latest equalized electric quantity of each battery cell based on the residual equalized electric quantity and the actual equalized electric quantity; And performing on-line equalization on each battery cell based on the latest equalized electric quantity. Optionally, the controlling the battery management system to enter the wake-up mode when the preset wake-up condition is met includes: Acquirin