一种基于Sepic-Zeta混合斩波电路的动力电池组双向高速均衡器研究

Study on a Two-way High Speed Equalizer for Traction Battery Pack Based on Sepic-Zeta Hybrid Chopper Circuit

本文提出一种基于Sepic-Zeta混合斩波电路的动力电池组双向高速均衡器,该均衡器在电池组3种不同的工作状态下采用不同均衡拓扑电路和均衡控制策略。电池组充电状态下,均衡电路等效为Sepic斩波电路,选择电池组中能量最高的单体电池作为Sepic斩波电路的输入端进行均衡放电,均衡放电电流连续;电池组放电状态下,均衡电路等效为Zeta斩波电路,选择电池组中能量最低的单体电池作为Zeta斩波电路的输出端进行均衡充电,均衡充电电流连续;电池组静置状态下,选择电池组中能量差异性最大的单体电池进行均衡放电或均衡充电,其对应的等效电路为Sepic或Zeta斩波电路。该均衡器拓扑电路原理简单,均衡电路容易实现,均衡能量易控制,均衡电流连续、可控,因此均衡速度快、均衡效率高。最后,搭建锂离子电池实验平台进行电池组3种工作状态下的均衡实验,验证了该方案的可行性。

A two-way high speed equalizer for traction battery pack based on Sepic-Zeta hybrid chopper circuit is proposed,which adopts different equalization topology circuits and equalization control strategies for three different operation states of battery pack.In the charging state of battery pack,Sepic chopper circuit is used as the equalization circuit,and the single cell having the highest energy in the battery pack is selected as the input of Sepic chopper circuit to conduct equalization discharging with continuous current.In the discharging state of battery pack,Zeta chopper circuit is used as the equalization circuit,and the single cell having the lowest energy in battery pack is selected as the output of Zeta chopper circuit to conduct equalization charging with continuous current.In the stationary state of battery pack,Sepic or Zeta chopper circuit is used as the equalization circuit,and the single cell having largest energy discrepancy is selected to conduct equalization discharging or equalization charging.The topology circuit of equalizer proposed is simple and easy to implement,the equalization energy is easy to control,and the equalization current is continuous and controllable,hence a speedy and efficient equalization can be achieved.Finally,an experimental platform for lithium-ion battery is built to perform equalization experiment under the three working conditions of battery pack,verifying the feasibility of the scheme put forward.