A kind of active balance control method of lithium-ion battery pack

Abstract

The invention belongs to the technical field of electric vehicles, and specifically relates to an active equalization control method for a lithium-ion battery pack. For most active equalization circuits, a three-threshold and interrupt equalization control strategy is adopted, wherein the three-threshold equalization not only includes the actions in the traditional control strategy Thresholds, including pre-action thresholds and end thresholds. By predicting the state of the single battery between the pre-action threshold and the action threshold in the next period of time, adjust its balance threshold appropriately. In the case that the three-threshold balance control strategy cannot take care of it, the interruption balance control strategy is activated to allow the battery to be interrupted during the balance process. Using the three-threshold and interrupt equalization control strategy can avoid the occurrence of equalization time overlap as much as possible without changing the circuit topology and increasing the equalization current.

Description

technical field [0001] The invention belongs to the technical field of electric vehicles, and in particular relates to an active equalization control method for a lithium-ion battery pack. Background technique [0002] Compared with traditional cars, electric vehicles have many advantages, such as: no pollution, low noise, high efficiency, etc. Therefore, electric vehicles have been favored by everyone in recent years, and their development momentum is very rapid, and power battery technology is a constraint on the development of electric vehicles. bottleneck. [0003] At present, lithium battery packs are generally used in electric vehicle vehicle-mounted power battery packs. In the electric vehicle battery pack, a large number of single cells need to be connected in series and parallel to increase the voltage and capacity of the battery pack to meet the needs of electric vehicles. There will be some differences in the process and performance of the individual batteries w...

AI Technical Summary

Problems solved by technology

[0005] Many active equalization circuits have the problem that the equalizer can only balance a single battery at the same time, and it may happen that the battery reaches the action threshold and cannot be balanced.

During the time the battery is waiting for equalization, its condition may be further deteriorated, which reduces the life of the battery pack

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