基于STM32的电池组飞渡电容均衡系统设计

Design of battery pack flying capacitor equalization system based on STM32

串并联的磷酸铁锂电池组存在不一致性,为了缓解由此带来的放电不一致性影响,文章采用改进的飞渡电容法进行均衡,其中测量精度决定着均衡效果。提出一种电池组极性自动判断方法和一种基于光电耦合器的测量方法,解决了常规方法中串联电池组测量线繁杂和测量精度不高的问题。采用基于Labview设计的上位机可监测显示电池组单体电压数值和曲线图。经实验测试静置状态下,均衡电压差在0.003V以内,均衡时间在70s以内;充电和放电状态下,效果相对有限。

There is inconsistency in the series-parallel LiFePO4 battery pack. In order to alleviate the impact of discharge inconsistency caused by this, an improved flying capacitor method was used to balance, and the measurement accuracy determines the equalization effect. An automatic judgment method of battery pack polarity and a measurement method based on photoelectric coupler are proposed, which solves the problems of redundant measurement lines and low measurement accuracy of series battery pack in conventional methods. The PC designed based on Labview can monitor and display the voltage value and curve of the battery unit. Under the static state, the equilibrium voltage difference is within 0.003 V and the equilibrium time is within 70 s.Under charging and discharging conditions, the effect is relatively limited.