一种锂电池多模组联合均衡系统的设计

Design of A Composite Equalization System for Lithium-ion Battery Modules

车用动力电池组在充放电循环使用中容易出现一致性恶化的现象,这会导致电池容量衰减甚至引发安全问题。为了解决此问题,文中提出了一种基于CAN网络的锂电池多模组联合均衡系统。该系统能够级联多个均衡器,每个均衡器能够利用充电芯片对电池模组进行主动均衡,同时结合小电阻阵列进行被动均衡,并利用串联在均衡器外部的大功率电阻为电池模组提供快速放电均衡。通过设计有效的控制策略与均衡算法,实现了多个模组联合均衡的目的。仿真和实验对控制策略与均衡算法进行了验证,在实验中,电池组电压极差从均衡前的200 mV缩小为均衡后的20 mV,证明该均衡系统可以有效改善电池组的一致性情况。

The vehicle power battery pack is prone to deterioration in consistency during charge and discharge cycles,which may cause battery capacity attenuation and even cause security problems.In this paper,a multi-equalizer composite equalization system based on CAN communication was proposed.The system could cascade multiple equalizer,and each equalizer included an active equalization part which used the charge chip to charge low power cell.The passive equalization part which composed of resistor arrays was used to discharge high power cell.In addition,each equalizer was equipped with a high-power resistance for battery module overall fast discharge.In order to achieve the purpose of composite equalization,effective control strategy and equalization algorithm were designed.The simulation and physical experiments were set up to validate control strategy and equalization algorithm.In the physical experiment,the voltage range of the battery pack was reduced from 200 mV before equalization to 20 mV after equalization,indicating that the consistency of the battery pack was obviously improved with the equalization system.