附带均衡电源的DC-DC均衡电路

DC-DC equilibrium circuit with equalized power supply

针对电动汽车中锂离子电池组使用主动均衡电路时,较难在灵活均衡的前提下减少元器件使用数目并保证高转换效率问题,文中提出带有均衡电源的主动均衡电路。该电路主要由融合目前优点的开关阵列、DC-DC变换器以及可以多重利用的均衡电源组成。根据电池组SOC(StateofCharge)的平均值与各单体电池SOC之差是否达到阈值为依据,使用Matlab/Simulink软件进行仿真。仿真结果表明,该结构可以在使用N+1+4个开关(N为串联电池组数目)和一个双向DC-DC变换器的前提下对串联电池组中任意单体电池进行均衡,并且电池在放电均衡时转换效率约为81.6%,电池在充电均衡时转换效率约为84.8%,均达到目前较高水平。证实该电路能较好地满足上述要求。

In allusion to the problem that it′s difficult to reduce the number of components and ensure the high conversion efficiency under the premise of flexibility and equilibrium when the active equilibrium circuit is used in lithium-ion battery pack of electric vehicle,an active equilibrium circuit with equalized power supply is proposed in this paper.The circuit is composed by a switch array,DC-DC converter and multiple-use equalized power supply,which fuse the advantages of current active equal-ization methods.The Matlab/Simulink software is applied to simulation test on the basis of whether the difference between the av-erage value of the battery pack SOC(state of charge)and SOC of single battery reaches threshold or not.The simulation results show that this structure can equalize any single battery of series battery pack under the premise of using N+1+4 switch(where N is the number of series batteries)and bidirectional DC-DC converter.The conversion efficiency of battery is about 81.6%at discharge equalization and 84.8%at charge equalization,all of which reaches the current high level.It is proved that the circuit can meet the above requirements.