电动汽车动力电池主动均衡控制设计

摘要

The power battery pack is a key part of pure electric vehicles and hybrid vehicles,but the inconsistency problem caused by the difference in the cells can shorten the service life of the pack obviously.The equalization circuit can reduce the cells inconsistency effectively.At present,the commonly used equalization circuits have the problems of complicated topology,more difficult to control balance,and longer equalization time.In order to solve these problems,an active equalization circuit was designed in the paper.The circuit can achieve fast bidirectional energy transfer between the cells with the fly back transformer,and the battery voltage and SOC were selected as equalization control amounts.The circuit model was built in the environment of Matlab/Simulink,and the simulation was done to test the system effectiveness,and the result was compared with that of the traditional inductive equalization circuit,Cuk equalization circuit and capacitance equalization circuit.The results show that the designed equalization system can realize the battery equalization with shortest time,lowest voltage difference and smallest dispersity,so it has important application value.%动力电池组是纯电动汽车和混合动力汽车中关键的组成部分,由于单体的差异使得电池组在频繁的充放电过程中出现不一致性的问题,影响电池组的使用寿命.通过均衡电路可以降低单体电池的不一致性.目前,常用的均衡电路会出现拓扑结构复杂,均衡控制比较困难,均衡时间长的问题.针对均衡电路拓扑结构复杂,均衡时间长的问题设计了一种主动均衡电路.上述电路以反激式变压器为核心,以电池电压和SOC作为均衡控制量,实现能量在单体电池之间快速的双向转移.在Matlab/Simulink环境下搭建了仿真电路模型,设计了均衡控制算法,并与传统电容均衡电路、电感均衡电路、Cuk均衡电路进行了仿真对比,仿真结果表明所设计的均衡电路和均衡控制算法,无论在均衡时间,压差和能量分散度方面都优于其它电路,具有重要的应用价值,为汽车电池主动均衡控制设计提供了科学依据.