中小锂电池组切换式均衡方法研究

Study on switched equalization for low-voltage or medium-voltage series battery pack

锂电池组单体不平衡现象会减弱电池组性能,甚至致使其损坏。基于切换式均衡结构提出一种新型均衡电路,采用多个MOSFET构建均衡器的开关切换阵列,利用全桥电路实现电池能量转移,通过理论推导分析均衡电路软启动、升压及降压模式工作原理,并设计基于模式切换的均衡控制策略,计算出各MOSFET导通时间。最后基于SIMULINK工具箱构建6串电池组均衡器仿真模型,完成电池组在充放电及静止状态下的仿真实验,验证了所提出的均衡电路及控制策略的可行性。该均衡方法实现成本低,扩展性能强。

The imbalance of cell will reduce the performance and even damage the series lithium-ion battery pack.Proposes a new equalization based on switched equalization structure.The switch array of the equalization is constructed from multiple MOSFETs.The excess energy transfer in cells is achieved through full-bridge circuit control.Using theoretical derivation,shows the working principles of the new equalization,including soft start mode,boost mode and buck mode.Then the equalization strategy is designed which based on modes switch,and the ON-time of each MOSFET is given.Finally,a simulation model including 6 series batteries is built on the SIMULINK,the feasibility of proposed equalization is verified by the equalization experiments of the battery pack in charging,discharging and static state.This equalization approach has the advantages of low implementation cost and strong scalability.