基于剩余容量在线估算的电池组主动均衡研究

Research on active equalization of battery pack based on the online estimation of remaining capacity

不一致性使得电池在成组后容量利用率方面远不及单体电池,现在的均衡方法注重防止电池过充过放,拓扑结构和控制策略没有兼顾能量利用效率,均衡过程能量损失较大,且存在均衡振荡现象。基于变压器法、相邻电感法和准谐振零电流开关技术,提出一种新型的主动均衡方案。该方案的控制策略以单体电池开路电压在线估计为基础,运用开路电压法估计SOC,并结合修正后的容量估算剩余电量,以使单体电池剩余电量差异在一定阈值范围内为目标。实验表明,该方案能适用于不同的动力需求,同时提高能量利用效率。

Inconsistency makes the battery pack in terms of capacity utilization far behind single cell.Recent equalization methods mainly focus on preventing battery from overcharge and over discharge without taking into account energy efficiency in topology and control strategy implementation,which leads to a large energy loss during equalization process and reciprocating oscillation.A novel balancing scheme is proposed based on transformer,next to next inductor and quasi-resonant zero current switching technology.In order to get the remaining capacity within a certain range,the control strategy of the scheme lies on its foundation on online estimation of open circuit voltage（OCV） of single cell,taking advantage of OCV-SOC curve to estimate the stage of charge（SOC） and combining with modified capacity to estimate the remaining capacity.The experimental results show that the scheme can be applied to different power requirements,meanwhile improve energy utilization efficiency.