High-performance lithium-ion battery equalization strategy for energy storage system

Abstract

Abstract In pursuit of low-carbon life, renewable energy is widely used, accelerating the development of lithium-ion batteries. Battery equalization is a crucial technology for lithium-ion batteries, and a simple and reliable voltage-equalization control strategy is widely used because the battery terminal voltage is very easy to obtain. But when the battery voltage is used to determine whether the battery needs to end equalization, it often does not reflect the state of charge well, resulting in battery management system misjudgment, which makes it unable to achieve a better equalization effect. In this paper, we propose a high-performance equalization control strategy based on the equalization data of the general equalization strategy, which turns on the equalization again after the equalization is completed and uses the equalization time instead of the battery voltage as the indicator. In this paper, we analyse and test this principle in detail. The difference between the final voltage of the equalized battery and the target voltage is only 4 versus 3 mV, which is an extreme advantage compared with the error of 18 versus 24 mV of the general equalization strategy, and it adds almost no workload, which makes it a good prospect for application.