基于SOC的锂动力电池多层双向自均衡方法

Multi-Level Bi-Directional Active Equalization Method in Lithium-Ion Power Battery Based on State-of-Charge

电池均衡是优化动力电池性能,提高使用寿命,增强动态工作过程安全性的一项关键技术.针对锂动力电池单体数量多,测量与控制数据量庞大等问题,本文将锂动力电池分为区域模块和全局模块两层,进而提出一种融合区域均衡与全局均衡的多层次协调均衡方法.通过开关电容区域均衡电路与反激式变压器全局均衡电路控制充放电过程的开关通断,实现双向均衡目标;在此基础上,考虑不同电池荷电状态(State of Charge,SOC)分布情况下锂电池的受电能力差异,以多模式充电策略为均衡前提条件,使用SOC关键参数作为均衡判据,实现系统充电与非充电过程的主动双向自均衡.实验结果表明,所提出的双向自均衡方法能实现高精度的均衡目标,且能耗较低.

Battery equalization is a key technology for improving the battery life ,enhancing the security and optimizing the performance .Due to the reason of too many cell numbers and huge data in measure and control ,this paper proposes a coordinated control method for regional and global equalization based on double-level structure in lithium-ion battery .Then two circuits are adopted to control the state of switch in the process of charge and discharge to archive the target of bi -directional equalization ,which are switch capacitor area equalization circuit and the fly-back transformer global equalization circuit .At the same time ,based on the discrepancy of efficiency among the different SOC distribution ,the multimodal charging strategy are applied as the key parameters of SOC criterion to realize the autonomic equalization in the process of charge and discharge .The experimental results show that the multi-level coordination equalization method proposed in this paper can realize the goal of high-precision equalization ,which is of good performance in equalization and low energy consumption .