基于在线开路电压估算的电池均衡指标研究

开路电压作为均衡指标可以准确反映电池组中单体的不一致性状态，如何在线实时获得开路电压是电池均衡研究的难点之一。使用BP神经网络结合当前工作状态下的电流、电压与荷电状态在线估算开路电压，并以此作为均衡指标在自主研制的BMS算法验证平台采用耗散型均衡方式实现电池放电阶段均衡。实验结果表明：在相同均衡策略下，在线估算的开路电压均衡指标与工作电压均衡指标相比，工作截止时的开路电压偏差近似为初始开路电压偏差的一半，因此能够准确地表征锂电池的不一致性。为电池组均衡指标的选择提供指导，促进电池组均衡技术的发展。

Research on Battery Equilibrium Index Based on Online Open Circuit Voltage Estimation

Open-circuit voltage as an equilibrium index can accurately reflect the inconsistency of cells in the battery pack.How to obtain the open circuit voltage online in real time is one of the difficulties in battery equilibrium research.The BP neural network estimates the open circuit voltage on-line with the current,voltage and state of charge in the current working state,and uses this voltage as an equilibrium index to achieve the battery discharge phase equalization using the dissipative equilibrium method in the self-developed BMS algorithm verification platform.The experimental results show that under the same equilibrium strategy,the open-circuit voltage equilibrium index estimated on-line compared with the operating voltage equilibrium index,the open-circuit voltage deviation at the working cutoff is nearly half of the initial open-circuit voltage deviation,so the lithium-ion battery inconsistency can be accurately characterized.It provides guidance for the selection of battery pack equalization indicators and promotes the development of battery pack equalization technology.