CN-122008959-A - Battery pack active equalization system, method, medium and vehicle

CN122008959ACN 122008959 ACN122008959 ACN 122008959ACN-122008959-A

Abstract

The embodiment of the application provides a battery pack active equalization system, a method, a medium and a vehicle, and relates to the technical field of battery equalization. The system comprises a battery pack, a first equalization module, a second equalization module and a controller, wherein the battery pack is composed of a plurality of single batteries connected in series, the first equalization module is configured to perform charge equalization on the single batteries by dynamically adjusting the circuit topology of the battery pack in a charging stage, the second equalization module is configured to perform re-equalization operation on the single batteries after the charging of the battery pack is stopped, and the controller is configured to control the first equalization module to perform equalization operation in the charging stage and control the second equalization module to perform re-equalization operation after the charging is stopped. According to the embodiment of the application, the first equalization module and the second equalization module are arranged, so that rapid topological equalization can be performed during charging, and polarization voltage drop is actively eliminated after the charging is finished, so that the equalization effect durability of the battery pack is improved, and the overall consistency and the available capacity of the battery pack are remarkably improved.

Inventors

HE CHUNLIN
CAO YUNPING
DING TIANXI
JIE LIZHU

Assignees

赛力斯汽车有限公司

Dates

Publication Date: 20260512
Application Date: 20260206

Claims (12)

1. A battery pack active equalization system, comprising: the battery pack is composed of a plurality of single batteries connected in series; the first equalization module is connected with the battery pack and is configured to perform charge equalization on each single battery by dynamically adjusting the circuit topology of the battery pack in the charge stage of the battery pack; The second equalization module is connected with the battery pack and is configured to respond to voltage difference caused by polarization effect after the battery pack is charged and cut off, and perform energy transfer between adjacent single batteries so as to perform re-equalization operation on each single battery; and the controller is respectively connected with the first equalization module and the second equalization module and is configured to control the first equalization module to execute equalization operation in the charging stage and control the second equalization module to execute re-equalization operation after the charging is stopped.
2. The battery pack active equalization system of claim 1, wherein the first equalization module comprises a reconfigurable switching circuit in parallel with each of the cells, the reconfigurable switching circuit configured to switch the corresponding cell into a charging loop or to bypass it from a charging loop in response to instructions from the controller.
3. The battery pack active equalization system of claim 2, wherein the reconfigurable switching circuit comprises a first switch and a second switch in parallel with each cell, wherein when the first switch is closed and the second switch is open, the corresponding cell is connected to a charging loop, and when the first switch is open and the second switch is closed, the corresponding cell is bypassed from the charging loop.
4. The battery pack active equalization system of claim 2, wherein the controller is configured to execute a consistency algorithm-based voltage equalization strategy during the charging phase; The voltage equalization strategy comprises the following steps: And determining single batteries serving as reference nodes, calculating voltage errors of the rest single batteries and the reference nodes, and controlling the states of the reconfigurable switching circuits based on the voltage errors.
5. The battery pack active equalization system of claim 1, wherein the second equalization module comprises a plurality of buck-boost converter circuit units, each buck-boost converter circuit unit disposed between two adjacent cells, each buck-boost converter circuit unit configured to effect bi-directional transfer of energy between a respective two of the cells.
6. The battery pack active equalization system of claim 1, wherein the controller is configured to: after the charging is stopped, controlling the battery pack to stand for a preset period of time, and collecting the voltage of each single battery; And calculating voltage difference based on the voltage of each single battery, and when the voltage difference exceeds a preset threshold, judging that the voltage difference caused by polarization effect exists, and controlling the second equalization module to execute re-equalization operation.
7. The battery pack active equalization system of claim 6, wherein the controller is configured to: And when the second equalization module is controlled to execute re-equalization operation, controlling a switching tube in each buck-boost conversion circuit unit to work at a preset duty ratio so as to work in a continuous conduction mode.
8. The battery active equalization system of claim 1, wherein the battery is charged during the charging phase using a constant current charging regime.
9. The battery pack active equalization system of claim 6, wherein the controller is configured to: after the second equalization module executes re-equalization operation, collecting the voltage of each single battery again, and judging whether the equalization target is reached; If the balance target is not reached, controlling the second balance module to execute re-balance operation again until the balance target is reached; The balancing target comprises that the voltage difference is lower than a preset threshold value or the number of times of re-balancing operation reaches a preset number of times threshold value.
10. A battery pack active equalization method, characterized by being applied to the battery pack active equalization system according to any one of claims 1-9, comprising: In the charging stage of the battery pack, the circuit topology of the battery pack is dynamically adjusted to perform charge balancing operation on the single batteries; After the charging of the battery pack is stopped, monitoring the voltage of each single battery to judge whether voltage difference caused by polarization effect exists or not; In the case where it is determined that the voltage difference exists, a re-equalization operation is performed on each unit cell by performing energy transfer between adjacent unit cells.
11. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when executed by a processor, performs the battery pack active equalization method according to claim 10.
12. A vehicle comprising a battery active equalization system as claimed in any of claims 1-9.

Description

Battery pack active equalization system, method, medium and vehicle Technical Field The application relates to the technical field of battery equalization, in particular to a battery pack active equalization system, a method, a medium and a vehicle. Background In practical application of the battery pack, voltage and capacity of each single battery in the battery pack are different due to factors such as manufacturing process and aging degree of the battery. If the equalization treatment is not performed in the charge and discharge process, partial batteries are easy to overcharge or overdischarge, and the service life of the battery pack is shortened. At present, in a common active equalization scheme, dynamic equalization can be realized in a charging stage, and charging efficiency is improved. However, the system often ignores the problem of inconsistent voltage caused by various factors after the charging is finished, so that the actual available capacity of the battery pack is reduced, the equalization effect is not durable, and the overall performance and the service life of the battery pack are further affected. Disclosure of Invention The embodiment of the application aims to provide a battery pack active equalization system, a battery pack active equalization method, a battery pack active equalization medium and a vehicle, which are used for improving the durability of a charge equalization effect of a battery pack. In a first aspect, an embodiment of the present application provides a method for active equalization of a battery pack, including: the battery pack is composed of a plurality of single batteries connected in series; the first equalization module is connected with the battery pack and is configured to perform charge equalization on each single battery by dynamically adjusting the circuit topology of the battery pack in the charge stage of the battery pack; The second equalization module is connected with the battery pack and is configured to respond to voltage difference caused by polarization effect after the battery pack is charged and cut off, and perform energy transfer between adjacent single batteries so as to perform re-equalization operation on each single battery; and the controller is respectively connected with the first equalization module and the second equalization module and is configured to control the first equalization module to execute equalization operation in the charging stage and control the second equalization module to execute re-equalization operation after the charging is stopped. In the embodiment of the application, the first equalization module and the second equalization module are arranged and controlled in a staged and cooperative manner by the same controller, so that the rapid topological equalization can be performed during charging, and the polarization voltage drop is actively eliminated after the charging is finished, thereby improving the equalization effect durability of the battery pack, and further remarkably improving the overall consistency and the available capacity of the battery pack. In some embodiments, the first equalization module includes a reconfigurable switching circuit in parallel with each of the cells, the reconfigurable switching circuit configured to switch the corresponding cell into or out of a charging loop in response to instructions from the controller. In the embodiment of the application, the single battery can be accurately connected into or bypassed to the charging loop according to the instruction by arranging the controlled reconfigurable switching circuit for each battery in parallel, so that the differentiation and selective charging of batteries with different electric quantities are realized, and the balanced pertinence and the energy utilization efficiency are improved. In some embodiments, the reconfigurable switching circuit includes a first switch and a second switch in parallel with each cell, wherein when the first switch is closed and the second switch is open, the corresponding cell is connected to a charging circuit, and when the first switch is open and the second switch is closed, the corresponding cell is bypassed from the charging circuit. In the embodiment of the application, by adopting a simple parallel circuit structure formed by two switches, reliable state switching can be realized with lower hardware cost, thereby simplifying circuit design and enhancing the feasibility and stability of the system. In some embodiments, the controller is configured to execute a voltage balancing strategy based on a consistency algorithm during the charging phase; The voltage equalization strategy comprises the following steps: And determining single batteries serving as reference nodes, calculating voltage errors of the rest single batteries and the reference nodes, and controlling the states of the reconfigurable switching circuits based on the voltage errors. In the embodiment of the application, the control